Patent Publication Number: US-7582688-B2

Title: Elastomer composites, method and apparatus

Description:
CROSS-REFERENCED APPLICATIONS AND PRIORITY CLAIM 
     This application claims the benefit of, and is a continuation application of, U.S. application Ser. No. 10/189,332 filed on Jul. 2, 2002 now abandoned which is incorporated herein by reference in its entirety for all purposes and which is a continuation of U.S. application Ser. No. 09/407,773, filed Sep. 28, 1999, now U.S. Pat. No. 6,413,478 issued Jul. 2, 2002, which is a continuation of U.S. patent application Ser. No. 08/823,411, filed Mar. 25, 1997, now U.S. Pat. No. 6,048,923 issued Apr. 11, 2000 which is a continuation-in-part of U.S. patent application Ser. No. 08/625,163 filed Apr. 1, 1996, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to novel methods and apparatus for producing elastomer composites, and to novel elastomer composites produced using such methods and apparatus. More particularly, the invention is directed to continuous flow methods and apparatus for producing elastomer masterbatch of particulate filler finely dispersed in elastomer, for example, elastomer composites of carbon black particulate filler finely dispersed in natural rubber, such as curative-free masterbatch compositions, curative-bearing base compositions, and rubber materials and products formed of such masterbatch compositions. 
     BACKGROUND 
     Numerous products of commercial significance are formed of elastomeric compositions wherein particulate filler is dispersed in any of various synthetic elastomers, natural rubber or elastomer blends. Carbon black, for example, is widely used as a reinforcing agent in natural rubber and other elastomers. It is common to produce a masterbatch, that is, a pr-mixture of filler, elastomer and various optional additives, such as extender oil. Carbon black masterbatch is prepared with different grades of commercially available carbon black which vary both in surface area per unit weight and in “structure.” Numerous products of commercial significance are formed of such elastomeric compositions of carbon black particulate filler dispersed in natural rubber. Such products include, for example, vehicle tires wherein different elastomeric compositions may be used for the tread portion, sidewalls, wire skim and carcass. Other products include, for example, engine mount bushings, conveyor belts, windshield wipers and the like. While a wide range of performance characteristics can be achieved employing currently available materials and manufacturing techniques, there has been a long standing need in the industry to develop elastomeric compositions having improved properties and to reduce the cost and complexity of current manufacturing techniques. In particular, it is known for example that macro-dispersion level, that is, the uniformity of dispersion of the carbon black or other filler within the elastomer, can significantly impact performance characteristics. For elastomeric compositions prepared by intensively mixing the carbon black or other filler with natural rubber or other elastomer (such as in a Banbury mixer or the like), any increase in macro-dispersion requires longer or more intensive mixing, with the consequent disadvantages of increased energy costs, manufacturing time, and similar concerns. For carbon black fillers of certain surface area and structure characteristics, dispersion beyond a certain degree has not been possible or commercially practicable using known mixing apparatus and techniques. In addition, such prolonged or more intensive mixing degrades the natural rubber by reducing its molecular weight, rendering the finished elastomeric compound undesirable for certain applications. 
     It is well known to employ carbon blacks having higher or lower structure and surface area to manipulate the performance characteristics of an elastomeric composition. Carbon blacks of higher surface area and lower structure are known to improve crack growth resistance and cut-and-chip resistance as well as, generally, abrasion resistance, and other performance qualities. Commercially available mixing techniques have been unable to achieve excellent uniformity of dispersion of carbon blacks throughout the elastomer, however, without unacceptable degradation of the natural rubber. In fact, for typical carbon black loading levels in natural rubber, such as 45 phr to 75 phr, and oil loading from 0 phr to 10 phr, low structure carbon blacks, such as carbon blacks of DBPA less than 110 cc/100 g, particularly those having surface area above about 45 m 2 /g to 65 m 2 /g (CTAB), it has not been possible to achieve compounds having less than about 1% undispersed carbon black (measured as macro-dispersion, as described below) regardless of the duration and level. Furthermore, as noted above, in the highly energy consumptive intensive dry mixing methods currently in widespread commercial use, the mastication of the elastomer necessary for dispersing such carbon blacks results in unacceptable levels of disruption of the polymeric chains of the natural rubber elastomer. The resultant reduction in the molecular weight of the natural rubber is undesirable for many industrial applications. For use in tire tread, for example, reduced molecular weight is known to cause an undesirable increase in the so-called rolling resistance of the tire. 
     Furthermore, while theoretical analysis has indicated desirable improvements in certain performance characteristics of elastomeric compositions employing carbon blacks of higher surface area and lower structure, it has not been possible using known physical milling or other mastication processes to obtain such elastomeric compositions in which both the molecular weight of the natural rubber is well preserved and satisfactory macro-dispersion levels of the carbon black are achieved. Generally, it has been found, for example, that the elastomer reinforcing properties of a carbon black increase as the particle size of the carbon black decreases. However, with extremely fine carbon blacks an anomalous condition is known to be encountered, in which the expected improvement in properties is not achieved. This is understood to be due at least in part to the inability of conventional elastomer compounding methods to adequately disperse the carbon black in the natural rubber without undue breakdown of the elastomer polymer. There has been, therefore, consequent inability to take full advantage of the natural affinity of the carbon black and the natural rubber for each other in the case of such carbon blacks. 
     Since good dispersion of carbon black in natural rubber compounds has been recognized for some time as one of the most important objectives for achieving good quality and consistent product performance, considerable effort has been devoted to the development of procedures for assessing dispersion quality in rubber. Methods developed include, e.g. the Cabot Dispersion Chart and various image analysis procedures. Dispersion quality can be defined as the state of mixing achieved. An ideal dispersion of carbon black is the state in which the carbon black agglomerates (or pellets) are broken down into aggregates (accomplished by dispersive mixing) uniformly separated from each other (accomplished by distributive mixing), with the surfaces of all the carbon black aggregates completely wetted by the rubber matrix (usually referred to as incorporation). 
     Common problems in the rubber industry which are often related to poor macro-dispersion can be classified into four major categories: product performance, surface defects, surface appearance and dispersion efficiency. The functional performance and durability of a carbon black-containing rubber formulation, such as tensile strength, fatigue life and wear resistance, are affected substantially by macro-dispersion quality. Undispersed carbon black can also cause surface defects on finished products, including visible defects. Eliminating the presence of surface defects is of critical importance in molded thin parts for functional reasons and in extruded profiles for both aesthetic and functional reasons. 
     A commercial image analyzer such as the IBAS Compact model image analyzer available from Kontron Electronik GmbH (Munich, Germany) can be used to measure macro-dispersion of carbon black or other filler. Typically, in quantitative macro-dispersion tests used in the rubber industry, the critical cut-off size is 10 microns. Defects larger than about 10 microns in size typically consist of undispersed black or other filler, as well as any grit or other contaminants, which can affect both visual and functional performance. Thus, measuring macro-dispersion involves measuring defects on a surface (generated by microtoming, extrusion or cutting) greater than 10 microns in size by total area of such defects per unit area examined using an image analysis procedure. Macro-dispersion D(%) is calculated as follows: 
               %   ⁢           ⁢   Undispersed   ⁢           ⁢   area   ⁢           ⁢     (   %   )       =       1     A   m       ⁢       ∑     i   =   1     m     ⁢       N   i     ⁢       π   ⁢           ⁢     D   i   2       4                 
where A m =Total sample surface area examined
         N i =Number of defects with size D i      D i =Diameter of circle having the same area as that of the defect (equivalent circle diameter).   m=number of images       
     Macro-dispersion of carbon black or other filler in uncured natural rubber or other suitable elastomer can be assessed using image analysis of cut surface samples. Typically, five to ten arbitrarily selected optical images are taken of the cut surface for image analysis. Knife marks and the like preferably are removed using a numerical filtering technique. Cut surface image analysis thus provides information regarding the carbon black dispersion quality inside a natural rubber compound. Specifically, percent undispersed area D(%) indicates carbon black macro-dispersion quality. As macro-dispersion quality is degraded, percent undispersed area increases. Dispersion quality can be improved, therefore, by reducing the percent undispersed area. As noted above, the mixing operations have a direct impact on mixing efficiency and on macro-dispersion. In general, better carbon black macro-dispersion is achieved in the elastomer, for example in a natural rubber masterbatch, by longer mixing and by more intensive mixing. Unfortunately, however, achieving better macro-dispersion by longer, more intensive mixing, degrades the elastomer into which the carbon black is being dispersed. This is especially problematic in the case of natural rubber, which is highly susceptible to mechanical/thermal degradation. Longer and more intensive mixing, using known mixing techniques and apparatus, such as a Banbury mixer, reduces the molecular weight of the natural rubber masterbatch-composition. Thus, improved macro-dispersion of carbon black in natural rubber is known to be achieved with a corresponding, generally undesirable reduction in the molecular weight of the rubber. 
     In addition to dry mixing techniques, it is known to continuously feed latex and a carbon black slurry to an agitated coagulation tank. Such “wet” techniques are used commonly with synthetic elastomer, such as SBR. The coagulation tank contains a coagulant such as salt or an aqueous or acid solution typically having a pH of about 2.5 to 4. The latex and carbon black slurry are mixed and coagulated in the coagulation tank into small beads (typically a few millimeters in diameter) referred to as wet crumb. The crumb and acid effluent are separated, typically by means of a vibrating shaker screen or the like. The crumb is then dumped into a second agitated tank where it is washed to achieve a neutral or near neutral pH. Thereafter the crumb is subjected to additional vibrating screen and drying steps and the like. Variations on this method have been suggested for the coagulation of natural and synthetic elastomers. In U.S. Pat. No. 4,029,633 to Hagopian et al, which like the present invention is assigned to Cabot Corporation, a continuous process for the preparation of elastomer masterbatch is described. An aqueous slurry of carbon black is prepared and mixed with a natural or synthetic elastomer latex. This mixture undergoes a so-called creaming operation, optionally using any of various known creaming agents. Following the creaming of the carbon black/latex mixture, it is subjected to a coagulation step. Specifically, the creamed carbon black/latex mixture is introduced as a single coherent stream into the core of a stream of coagulating liquor. The solid stream of creamed carbon black/latex mixture is said to undergo shearing and atomizing by the stream of coagulating liquor prior to coagulation, being then passed to a suitable reaction zone for completion of the coagulation. Following such coagulation step, the remainder of the process is substantially conventional, involving separation of the crumb from the waste product “serum” and washing and drying of the crumb. A somewhat similar process is described in U.S. Pat. No. 3,048,559 to Heller et al. An aqueous slurry of carbon black is continuously blended with a stream of natural or synthetic elastomer or latex. The two streams are mixed under conditions described as involving violent hydraulic turbulence and impact. As in the case of the Hagopian et al patent mentioned above, the combined stream of carbon black slurry and elastomer latex is subsequently coagulated by the addition of an acid or salt coagulant solution. 
     There has long been a need in various industries for elastomeric compounds of particulate filler dispersed in suitable elastomer, especially, for example, carbon black dispersed in natural rubber, having improved macro-dispersion. As discussed above, improved macro-dispersion can provide correspondingly improved aesthetic and functional characteristics. Especially desirable are new elastomeric compounds of carbon black in natural rubber wherein improved macro-dispersion is achieved together with higher molecular weight of the natural rubber. It is an object of the present invention to meet some or all of these long felt needs. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect, a method for preparing elastomer masterbatch involves feeding simultaneously a particulate filler fluid and an elastomer latex fluid to a mixing zone of a coagulum reactor. A coagulum zone extends from the mixing zone, preferably progressively increasing in cross-sectional area in the downstream direction from an entry end to a discharge end. The elastomer latex may be either natural or synthetic and the particulate filler fluid comprises carbon black or other particulate filler effective to coagulate the latex. The particulate filler fluid is fed to the mixing zone preferably as a continuous, high velocity jet of injected fluid, while the latex fluid is fed at low velocity. The velocity, flow rate and particulate concentration of the particulate filler fluid are sufficient to cause mixture with high shear of the latex fluid and flow turbulence of the mixture within at least an upstream portion of the coagulum zone so as to substantially completely coagulate the elastomer latex with the particulate filler prior to the discharge end. Substantially complete coagulation can thus be achieved, in accordance with preferred embodiments, without the need of employing an acid or salt coagulation agent. 
     In accordance with another aspect, a continuous flow method of producing elastomer masterbatch comprises the continuous and simultaneous feeding of latex fluid and particulate filler fluid to the mixing zone of the coagulum reactor establishing a continuous, semi-confined flow of a mixture of the elastomer latex and particulate filler in the coagulum zone. Elastomer masterbatch crumb in the form of “worms” or globules are discharged from the discharge end of the coagulum reactor as a substantially constant flow concurrently with the on-going feeding of the latex and particulate filler fluid streams into the mixing zone of the coagulum reactor. Notably, the plug-type flow and atmospheric or near atmospheric pressure conditions at the discharge end of the coagulum reactor are highly advantageous in facilitating control and collection of the elastomer masterbatch product, such as for immediate or subsequent further processing steps. 
     In accordance with an apparatus aspect, means are provided for feeding elastomer latex fluid to the mixing zone of the aforesaid coagulum reactor, preferably under low pressure, substantially laminar type flow conditions, and means are provided for simultaneously feeding particulate filler fluid to the mixing zone under pressure sufficient to create a jet of sufficient velocity or kinetic energy to entrain the elastomer latex as described above, and achieve coagulation before the mixture flowing downstream from the mixing zone reaches the discharge end of the coagulum reactor. In accordance with certain preferred embodiments described in detail below, means for feeding the elastomer latex fluid and separate means for feeding the particulate filler fluid each may comprise a feed channel in a mix head integral with a substantially tubular member defining the coagulum zone. The mixing zone may be provided at the junction of such feed channels within the mix head. In accordance with certain preferred embodiments, the mixing zone is simply a coaxial extension of the coagulum zone. Progressive increase in the cross-sectional area of the coagulum reactor is continuous in certain preferred embodiments and is step-wise in other preferred embodiments. Additionally, the coagulum reactor may be provided with such optional features as a diverter at its discharge end, as further described below. Additional optional and preferred features of the apparatus disclosed here for continuous flow production of elastomer masterbatch are discussed in the detailed description below. 
     In accordance with yet another aspect, elastomer composites are provided as a product of the process or apparatus disclosed above. In accordance with preferred embodiments, novel elastomer composites are provided having macro-dispersion level of the particulate filler, molecular weight of the elastomer, particulate loading level, choice of particulate filler (including, for example, carbon black fillers of exceptionally high surface area and low structure) and/or other characteristics not previously achieved. In that regard, the methods and apparatus disclosed here can achieve excellent macro-dispersion, even of certain fillers, such as carbon blacks having a structure to surface area ratio DBP:CTAB less than 1.2 and even less than 1, in elastomers such as natural rubber, with little or no degradation of the molecular weight of the elastomer. In accordance with yet other aspects of the invention, intermediate products are provided as well as final products which are formed of the elastomer composites produced by the method or apparatus disclosed here. 
     In accordance with another aspect, novel elastomer composites are provided, comprising a particulate filler dispersed in natural rubber, the macro-dispersion level of the filler in the elastomer composite being less than about 0.2% undispersed area, preferably less than about 0.1% undispersed area. Consistent with the discussion above, macro-dispersion here means the macro-dispersion D(%) of the carbon black measured as percent undispersed area for defects larger than 10 microns. In natural rubber masterbatch and other elastomer composites disclosed here, the molecular weight of the natural rubber, that is, the MW sol  (weight average) of the sol portion, preferably is at least about 300,000, more preferably at least about 400,000, being in certain preferred embodiments between 400,000 and 900,000. The elastomer composites optionally comprise extender oil, such as about 0 to 20 phr, more preferably about 0 to 10 phr extender oil, and/or other ingredients such as are well known for optional use in compounding natural rubber with carbon black filler. As discussed further below in connection with certain preferred and exemplary embodiments, the novel elastomer composites disclosed here can provide highly desirable physical properties and performance characteristics. Accordingly, the invention presents a significant technological advance. 
     In accordance with another aspect, novel elastomer composites are provided in which there is a novel, heretofore unobtained, combination of properties, including certain macro-dispersion level of the carbon black filler, molecular weight of the natural rubber, carbon black loading level carbon black characteristics (including surface area and structure, e.g., carbon black fillers of exceptionally high surface area and low structure) and/or other characteristics. In accordance with various aspects of the invention, masterbatch compositions and intermediate products are provided, as well as final products which are formed of them. 
     These and other aspects and advantages of various embodiments of the invention will be further understood in view of the following detailed discussion of certain preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following discussion of certain preferred embodiments will make reference to the appended drawings wherein: 
         FIG. 1  is a schematic flow chart illustration of the apparatus and method for preparing elastomer masterbatch in accordance with certain preferred embodiments; 
         FIG. 2  is an elevation view, partly schematic, of a preferred embodiment consistent with the schematic flow chart illustration of  FIG. 1 ; 
         FIG. 3  is an elevation view, partially schematic, of an alternative preferred embodiment consistent with the schematic flow chart illustration of  FIG. 1 ; 
         FIG. 4  is an elevation view, partially in section, of the mix head/coagulum reactor assembly of the embodiment of  FIG. 3 ; 
         FIG. 5  is an elevation view, partially in section, corresponding to the view of  FIG. 4 , illustrating an alternative preferred embodiment; 
         FIG. 6  is a section view taken through line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a section view of a mix head suitable for use in an alternative preferred embodiment; 
         FIG. 8  is a graph showing the surface area and structure properties (CTAB and DBPA) of carbon blacks employed in certain highly preferred masterbatch compositions in accordance with the present invention; 
         FIGS. 9-25  are graphs showing the macro-dispersion, natural rubber molecular weight and/or other characteristics of novel elastomer composites in accordance with this invention comprising carbon blacks shown in  FIG. 8 , in some cases along with data relating to control samples for comparison, exemplifying the significant improvements in physical characteristics and performance properties achieved by the elastomer composites; 
         FIGS. 26-29  are graphs-showing morphological properties of carbon blacks, i.e., structure (DBPA) and surface area (CTAB), and identifying regions or zones of carbon blacks (by such morphological properties) which are suitable for specific product applications; and 
         FIGS. 30 and 31  are graphs showing the macro-dispersion and natural rubber molecular weight of novel elastomer composites in accordance with this invention, along with control samples for comparison. 
     
    
    
     It should be understood that the appended drawings are not necessarily precisely to scale. Certain features may have been enlarged or reduced for convenience or clarity of illustration. Directional references used in the following discussion are based on the orientation of components illustrated in the drawings unless otherwise stated or otherwise clear from the context. In general, apparatus in accordance with different embodiments of the invention can be employed in various arrangements. It will be within the ability of those skilled in the art, given the benefit of the present disclosure, to determine appropriate dimensions and orientations for apparatus of the invention employing routine technical skills and taking into account well-known factors particular to the intended application, such as desired production volumes, material selection, duty cycle, and the like. Reference numbers used in one drawing may be used in other drawings for the same feature or element. 
     DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS 
     By virtue of the method and apparatus disclosed here, elastomer masterbatch can be produced in a continuous flow process involving mixture of elastomer latex and particulate filler fluids at turbulence levels and flow control conditions sufficient to achieve coagulation even without use of traditional coagulating agents. In fact, it will be immediately recognized to be of great commercial benefit that elastomer masterbatch crumb is achieved, that is, coagulated latex is achieved, here without the need for either intensive dry mastication of elastomer with filler or exposing a liquid latex/particulate composition to a stream or tank of coagulant. Thus, in routine commercial implementation the cost and complexity of employing acid coagulation solutions can be avoided. Prior techniques involving premixing of latex and particulate, such as in the above-mentioned Heller et al patent and Hagopian et al patent do not even recognize the possibility of achieving coagulation without exposing the latex/particulate mixture to the usual coagulant solution with its attendant cost and waste disposal disadvantages. 
     Feed rates of latex fluid and particulate filler fluid to the mixing zone of the coagulum reactor can be precisely metered to achieve high yield rates, with little free latex and little undispersed filler in the product crumb at the discharge end of the coagulum reactor. Without wishing to be bound by theory, it presently is understood that a quasi-mono-phase system is established in the mixing zone except that coagulum solids are being formed there and/or downstream thereof in the coagulum zone. Extremely high feed velocity of the particulate filler fluid into the mixing zone of the coagulum reactor and velocity differential relative the latex fluid feed are believed to be significant in achieving sufficient turbulence, i.e., sufficiently energetic shear of the latex by the impact of the particulate filler fluid jet for thorough mixing and dispersion of the particulate into the latex fluid and coagulation. High mixing energies yield product masterbatch crumb with excellent dispersion, together with controlled product delivery. The coagulum is created and then formed into a desirable extrudate. 
     Certain preferred embodiments are discussed below, of methods and apparatus for producing the novel elastomer composites disclosed here. While various preferred embodiments of the invention can employ a variety of different fillers and elastomers, certain portions of the following detailed description of method and apparatus aspects of the invention will, in some instances, for convenience, describe their use primarily in producing masterbatch comprising natural rubber and carbon black. It will be within the ability of those skilled in the art, given the benefit of this disclosure, to employ the method and apparatus disclosed here in accordance with the principles of operation discussed below to produce masterbatch comprising a number of alternative or additional elastomers, fillers and other materials. In brief, such methods for preparing elastomer masterbatch involve feeding simultaneously a slurry of carbon black or other filler and a natural rubber latex fluid or other suitable elastomer fluid to a mixing zone of a coagulum reactor. A coagulum zone extends from the mixing zone, preferably progressively increasing in cross-sectional area in the downstream direction from an entry end to a discharge end. The slurry is fed to the mixing zone preferably as a continuous, high velocity jet of injected fluid, while the natural rubber latex fluid is fed at relatively low velocity. The high velocity, flow rate and particulate concentration of the filler slurry are sufficient to cause mixture and high shear of the latex fluid, flow turbulence of the mixture within at least an upstream portion of the coagulum zone, and substantially completely coagulate the elastomer latex prior to the discharge end. Substantially complete coagulation can thus be achieved, in accordance with preferred embodiments, without the need of employing an acid or salt coagulation agent. The preferred continuous flow method of producing the elastomer composites comprises the continuous and simultaneous feeding of the latex fluid and filler slurry to the mixing zone of the coagulum reactor, establishing a continuous, semi-confined flow of a mixture of the latex and filler slurry in the coagulum zone. Elastomer composite crumb in the form of “worms” or globules are discharged from the discharge end of the coagulum reactor as a substantially constant flow concurrently with the on-going feeding of the latex and carbon black slurry streams into the mixing zone of the coagulum reactor. Notably, the plug-type flow and atmospheric or near atmospheric pressure conditions at the discharge end of the coagulum reactor are highly advantageous in facilitating control and collection of the elastomer composite product, such as for immediate or subsequent further processing steps. Feed rates of the natural rubber latex fluid and carbon black slurry to the mixing zone of the coagulum reactor can be precisely metered to achieve high yield rates, with little free latex and little undispersed carbon black in the product crumb at the discharge end of the coagulum reactor. Without wishing to be bound by theory, it presently is understood that a quasi-mono-phase system is established in the mixing zone except that coagulum solids are being formed there and/or downstream thereof in the coagulum zone. Extremely high feed velocity of the carbon black slurry into the mixing zone of the coagulum reactor and velocity differential relative the natural rubber latex fluid feed are believed to be significant in achieving sufficient turbulence, i.e., sufficiently energetic shear of the latex by the impact of the particulate filler fluid jet for thorough mixing and dispersion of the particulate into the latex fluid and coagulation. High mixing energies yield the novel product with excellent macro-dispersion, together with controlled product delivery. The coagulum is created and then formed into a desirable extrudate. 
     The aforesaid preferred apparatus and techniques for producing the elastomer composites disclosed here are discussed in conjunction with the appended drawings, wherein a continuous flow method of producing elastomer masterbatch employs a continuous, semi-confined flow of elastomer latex, for example, natural rubber latex (field latex or concentrate) mixed with a filler slurry, for example, an aqueous slurry of carbon black, in a coagulum reactor forming an elongate coagulum zone which extends, preferably with progressively increasing cross-sectional area, from an entry end to a discharge end. The term “semi-confined” flow refers to a highly advantageous feature. As used here the term is intended to mean that the flow path followed by the mixed latex fluid and filler slurry within the coagulum reactor is closed or substantially closed upstream of the mixing zone and is open at the opposite, downstream end of the coagulum reactor, that is, at the discharge end of the coagulum reactor. Turbulence conditions in the upstream portion of the coagulum zone are maintained in on-going, at least quasi-steady state fashion concurrently with substantially plug flow-type conditions at the open discharge end of the coagulum reactor. The discharge end is “open” at least in the sense that it permits discharge of coagulum, generally at or near atmospheric pressure and, typically, by simple gravity drop (optionally within a shrouded or screened flow path) into suitable collection means, such as the feed hopper of a de-watering extruder. Thus, the semi-confined flow results in a turbulence gradient extending axially or longitudinally within at least a portion of the coagulum reactor. Without wishing to be bound by theory, it presently is understood that the coagulum zone is significant in permitting high turbulence mixing and coagulation in an upstream portion of the coagulum reactor, together with substantially plug-type discharge flow of a solid product at the discharge end. Injection of the carbon black or other filler slurry as a continuous jet into the mixing zone occurs in on-going fashion simultaneously with ease of collection of the elastomer masterbatch crumb discharged under substantially plug-type flow conditions and generally ambient pressure at the discharge end of the coagulum reactor. Similarly, axial velocities of the slurry through the slurry nozzle into the mixing zone and, typically, at the upstream end of the coagulum zone are substantially higher than at the discharge end. Axial velocity of the slurry will typically be several hundred feet per second as it enters the mixing zone, preferably from a small bore, axially oriented feed tube in accordance with preferred embodiments discussed below. The axial velocity of the resultant flow at the entry end of a coagulum reactor with expanding cross-sectional area in a typical application may be, for example, 5 to 20 feet per second, and more usually 7 to 15 feet per second. At the discharge end, in contrast again, axial velocity of the masterbatch crumb product being discharged there will in a typical application be approximately 1 to 10 feet per second, and more generally 2 to 5 feet per second. Thus, the aforesaid semi-confined turbulent flow achieves the highly significant advantage that natural rubber or other elastomer latex is coagulated by mixture with carbon black or other filler even in the absence of subsequent treatment in a stream or tank of acid, salt or other coagulant solution, with controlled, preferably quasi-molded product delivery from the coagulum reactor for subsequent processing. 
     It should be understood in this regard that reference to the coagulum reactor as being “open” at the discharge end is not intended to mean that the discharge end is necessarily exposed to view or easily accessed by hand. It may instead be permanently or releasably attached to a collection device or subsequent processing device, such as a diverter (discussed further below), dryer, etc. The discharge end of the coagulum reactor is open in the important sense that the turbulent flow within the coagulum zone of the coagulum reactor, which is under high pressure and sealed against any significant rearward (i.e., upstream) travel at the mixing zone, is permitted to establish the aforesaid pressure and/or velocity gradient as it travels toward and exits from the discharge end. 
     It should also be recognized in this regard that the turbulence of the flow lessens along the coagulum reactor toward the discharge end. Substantial plug flow of a solid product is achieved prior to the discharge end, dependent upon such factors as percent of capacity utilization, selection of materials and the like. Reference here to the flow being substantially plug flow at or before the discharge end of the coagulum reactor should be understood in light of the fact that the flow at the discharge end is composed primarily or entirely of masterbatch crumb, that is, globules or “worms” of coagulated elastomer masterbatch. The crumb is typically quasi-molded to the inside shape of the coagulum zone at the point along the coagulum zone at which flow became substantially plug flow. The ever-advancing mass of “worms” or globules advantageously have plug-type flow in the sense that they are traveling generally or primarily axially toward the discharge end and at any point in time in a given cross-section of the coagulum zone near the discharge end have a fairly uniform velocity, such that they are readily collected and controlled for further processing. Thus, the fluid phase mixing aspect disclosed here can advantageously be carried out at steady state or quasi-steady state conditions, resulting in high levels of product uniformity. 
     A preferred embodiment of the method and apparatus disclosed here is illustrated schematically in  FIG. 1 . Those skilled in the art will recognize that the various aspects of system configuration, component selection and the like will depend to some extent on the particular characteristics of the intended application. Thus, for example, such factors as maximum system through-put capacity and material selection flexibility will influence the size and layout of system components. In general, such considerations will be well within the ability of those skilled in the art given the benefit of the present disclosure. The system illustrated in  FIG. 1  is seen to include means for feeding natural rubber latex or other elastomer latex fluid at low pressure and low velocity continuously to a mixing zone of a coagulum reactor. More particularly, a latex pressure tank  10  is shown, to hold the feed supply of latex under pressure. Alternatively, a latex storage tank can be used, equipped with a peristaltic pump or series of pumps or other suitable feed means adapted to hold elastomer latex fluid to be fed via feed line  12  to a mixing zone of a coagulum reactor  14 . Latex fluid in tank  10  may be held under air or nitrogen pressure or the like, such that the latex fluid is fed to the mixing zone at a line pressure of preferably less than 10 psig, more preferably about 2-8 psig, and typically about 5 psig. The latex feed pressure and the flow lines, connections, etc., of the latex feed means should be arranged to cause shear in the flowing latex fluid as low as reasonably possible. Preferably all flow lines, for example, are smooth, with only large radius turns, if any, and smooth or faired line-to-line interconnections. The pressure is selected to yield the desired flow velosity into the mixing zone; an example of a useful flow velocity is no more than about 12 feet per second. 
     Suitable elastomer latex fluids include both natural and synthetic elastomer latices and latex blends. The latex must, of course, be suitable for coagulation by the selected particulate filler and must be suitable for the intended purpose or application of the final rubber product. It will be within the ability of those skilled in the art to select suitable elastomer latex or a suitable blend of elastomer latices for use in the methods and apparatus disclosed here, given the benefit of this disclosure. Exemplary elastomers include, but are not limited to, rubbers, polymers (e.g., homopolymers, copolymers and/or terpolymers) of 1,3-butadiene, styrene, isoprene, isobutylene, 2,3-dimethyl-1,3-butadiene, acrylonitrile, ethylene, and propylene and the like. The elastomer may have a glass transition temperature (Tg) as measured by differential scanning calorimetry (DSC) ranging from about −120° C. to about 0° C. Examples include, but are not limited to, styrene-butadiene rubber (SBR), natural rubber and its derivatives such as chlorinated rubber, polybutadiene, polyisoprene, poly(stryene-co-butadiene) and the oil extended derivatives of any of them. Blends of any of the foregoing may also be used. The latex may be in an aqueous carrier liquid. Alternatively, the liquid carrier may be a hydrocarbon solvent. In any event, the elastomer latex fluid must be suitable for controlled continuous feed at appropriate velocity, pressure and concentration into the mixing zone. Particular suitable synthetic rubbers include: copolymers of from about 10 to about 70 percent by weight of styrene and from about 90 to about 30 percent by weight of butadiene such as copolymer of 19 parts styrene and 81 parts butadiene, a copolymer of 30 parts styrene and 70 parts butadiene, a copolymer of 43 parts styrene and 57 parts butadiene and a copolymer of 50 parts styrene and 50 parts butadiene; polymers and copolymers of conjugated dienes such as polybutadiene, polyisoprene, polychloroprene, and the like, and copolymers of such conjugated dienes with an ethylenic group-containing monomer copolymerizable therewith such as styrene, methyl styrene, chlorostyrene, acrylonitrile, 2-vinyl-pyridine, 5-methyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine, 2-methyl-5-vinylpyridine, alkyl-substituted acrylates, vinyl ketone, methyl isopropenyl ketone, methyl vinyl either, alphamethylene carboxylic acids and the esters and amides thereof such as acrylic acid and dialkylacrylic acid amide. Also suitable for use herein are copolymers of ethylene and other high alpha olefins such as propylene, butene-1 and pentene-1. As noted further below, the rubber compositions of the present invention can contain, in addition to the elastomer and filler, curing agents, a coupling agent, and optionally, various processing aids, oil extenders and antidegradents. 
     In that regard, it should be understood that the elastomer composites disclosed here include vulcanized compositions (VR), thermoplastic vulcanizates (TPV), thermoplastic elastomers (TPE) and thermoplastic polyolefins (TPO). TPV, TPE, and TPO materials are further classified by their ability to be extruded and molded several times without loss of performance characteristics. Thus, in making the elastomer composites one or more curing agents such as, for example, sulfur, sulfur donors, activators, accelerators, peroxides, and other systems used to effect vulcanization of the elastomer composition may be used. 
     Where the elastomer latex comprises natural rubber latex, the natural rubber latex can comprise field latex or latex concentrate (produced, for example, by evaporation, centrifugation or creaming). The natural rubber latex must, of course, be suitable for coagulation by the carbon black. The latex is provided typically in an aqueous carrier liquid. Alternatively, the liquid carrier may be a hydrocarbon solvent. In any event, the natural rubber latex fluid must be suitable for controlled continuous feed at appropriate velocity, pressure and concentration into the mixing zone. The well known instability of natural rubber latex is advantageously accommodated, in that it is subjected to relatively low pressure and low shear throughout the system until it is entrained into the aforesaid semi-confined turbulent flow upon encountering the extraordinarily high velocity and kinetic energy of the carbon black slurry in the mixing zone. In certain preferred embodiments, for example, the natural rubber is fed to the mixing zone at a pressure of about 5 psig, at a feed velocity in the range of about 3-12 ft. per second, more preferably about 4-6 ft. per second. Selection of a suitable latex or blend of latices will be well within the ability of those skilled in the art given the benefit of the present disclosure and the knowledge of selection criteria generally well recognized in the industry. 
     The particulate filler fluid, for example, carbon black slurry, is fed to the mixing zone at the entry end of coagulum reactor  14  via feed line  16 . The slurry may comprise any suitable filler in a suitable carrier fluid. Selection of the carrier fluid will depend largely upon the choice of particulate filler and upon system parameters. Both aqueous and non-aqueous liquids may be used, with water being preferred in many embodiments in view of its cost, availability and suitability of use in the production of carbon black and certain other filler slurries. 
     When a carbon black filler is used, selection of the carbon black will depend largely upon the intended use of the elastomer masterbatch product. Optionally, the carbon black filler can include also any material which can be slurried and fed to the mixing zone in accordance with the principles disclosed here. Suitable additional particulate fillers include, for example, conductive fillers, reinforcing fillers, fillers comprising short fibers (typically having an L/D aspect ratio less than 40), flakes, etc. Thus, exemplary particulate fillers which can be employed in producing elastomer masterbatch in accordance with the methods and apparatus disclosed here, are carbon black, fumed silica, precipitated silica, coated carbon black, chemically functionalized carbon blacks, such as those having attached organic groups, and silicon-treated carbon black, either alone or in combination with each other. Suitable chemically functionalized carbon blacks include those disclosed in International Application No. PCT/US95/16194 (WO9618688), the disclosure of which is hereby incorporated by reference. In silicon-treated carbon black, a silicon containing species such as an oxide or carbide of silicon, is distributed through at least a portion of the carbon black aggregate as an intrinsic part of the carbon black. Conventional carbon blacks exist in the form of aggregates, with each aggregate consisting of a single phase, which is carbon. This phase may exist in the form of a graphitic crystallite and/or amorphous carbon, and is usually a mixture of the two forms. As discussed elsewhere herein, carbon black aggregates may be modified by depositing silicon-containing species, such as silica, on at least a portion of the surface of the carbon black aggregates. The result may be described as silicon-coated carbon blacks. The materials described herein as silicon-treated carbon blacks are not carbon black aggregates which have been coated or otherwise modified, but actually represent a different kind of aggregate. In the silicon-treated carbon blacks, the aggregates contain two phases. One phase is carbon, which will still be present as graphitic crystallite and/or amorphous carbon, while the second phase is silica (and possibly other silicon-containing species). Thus, the silicon-containing species phase of the silicon-treated carbon black is an intrinsic part of the aggregate; it is distributed throughout at least a portion of the aggregate. It will be appreciated that the multiphase aggregates are quite different from the silica-coated carbon blacks mentioned above, which consist of pre-formed, single phase carbon black aggregates having silicon-containing species deposited on their surface. Such carbon blacks may be surface-treated in order to place a silica functionality on the surface of the carbon black aggregate. In this process, an existing aggregate is treated so as to deposit or coat silica (as well as possibly other silicon-containing species) on at least a portion of the surface of the aggregate. For example, an aqueous sodium silicate solution may be used to deposit amorphous silica on the surface of carbon black aggregates in an aqueous slurry at high pH, such as 6 or higher, as discussed in Japanese Unexamined Laid-Open (Kokai) Publication No. 63-63755. More specifically, carbon black may be dispersed in water to obtain an aqueous slurry consisting, for example, of about 5% by weight carbon black and 95% by weight water. The slurry is heated to above about 70° C., such as to 85-95° C., and the pH adjusted to above 6, such as to a range of 10-11, with an alkali solution A separate preparation is made of sodium silicate solution, containing the amount of silica which is desired to be deposited on the carbon black, and an acid solution to bring the sodium silicate solution to a neutral pH. The sodium silicate and acid solutions are added dropwise to the slurry, which is maintained at its starting pH value with acid or alkali solution as appropriate. The temperature of the solution is also maintained. A suggested rate for addition of the sodium silicate solution is to calibrate the dropwise addition to add about 3 weight percent silicic acid, with respect to the total amount of carbon black, per hour. The slurry should be stirred during the addition, and after its completion for from several minutes (such as 30) to a few hours (i.e., 2-3). In contrast, silicon-treated carbon blacks may be obtained by manufacturing carbon black in the presence of volatizable silicon-containing compounds. Such carbon blacks are preferably produced in a modular or “staged” furnace carbon black reactor having a combustion zone followed by a zone of converging diameter, a feed stock injection zone with restricted diameter, and a reaction zone. A quench zone is located downstream of the reaction zone. Typically, a quenching fluid, generally water, is sprayed into the stream of newly formed carbon black particles flowing from the reaction zone. In producing silicon-treated carbon black, the aforesaid volatizable silicon-containing compound is introduced into the carbon black reactor at a point upstream of the quench zone. Useful compounds are volatizable compounds at carbon black reactor temperatures. Examples include, but are not limited to, silicates such as tetraethoxy orthosilicate (TEDS) and tetramethoxy orthosilicate, silanes such as, tetrachloro silane, and trichloro methylsilane; and colatile silicone polymers such as octamethylcyclotetrasiloxane (OMTS). The flow rate of the volatilizable compound will determine the weight percent of silicon in the treated carbon black. The weight percent of silicon in the treated carbon black typically ranges from about 0.1 percent to 25 percent, preferably about 0.5 percent to about 10 percent, and more preferably about 2 percent to about 6 percent. The volatizable compound may be pre-mixed with the carbon black-forming feed stock and introduced with the feed stock into the reaction zone. Alternatively, the volatizable compound may be introduced to the reaction zone separately, either upstream or downstream from the feed stock injection point. 
     As noted above, additives may be used, and in this regard coupling agents useful for coupling silica or carbon black should be expected to be useful with the silicon-treated carbon blacks. Carbon blacks and numerous additional suitable particulate fillers are commercially available and are known to those skilled in the art. 
     Selection of the particulate filler or mixture of particulate fillers will depend largely upon the intended use of the elastomer masterbatch product. As used here, particulate filler can include any material which can be slurried and fed to the mixing zone in accordance with the principles disclosed here. Suitable particulate fillers include, for example, conductive fillers, reinforcing fillers, fillers comprising short fibers (typically having an L/D aspect ratio less than 40), flakes, etc. In addition to the carbon black and silica-type fillers mentioned above, fillers can be formed of clay, glass, polymer, such as aramid fiber, etc. It will be within the ability of those skilled in the art to select suitable particulate fillers for use in the method and apparatus disclosed here given the benefit of the present disclosure, and it is expected that any filler suitable for use in elastomer compositions may be incorporated into the elastomer composites using the teachings of the present disclosure. Of course, blends of the various particulate fillers discussed herein may also be used 
     Preferred embodiments of the invention consistent with  FIG. 1  are especially well adapted to preparation of particulate filler fluid comprising aqueous slurries of carbon black. In accordance with known principles, it will be understood that carbon blacks having lower surface area per unit weight must be used in higher concentration in the particulate slurry to achieve the same coagulation efficacy as lower concentrations of carbon black having higher surface area per unit weight. Agitated mixing tank  18  receives water and carbon black, e.g., optionally pelletized carbon black, to prepare an initial mixture fluid. Such mixture fluid passes through discharge port  20  into fluid line  22  equipped with pumping means  24 , such as a diaphragm pump or the like. Line  28  passes the mixture fluid to colloid mill  32 , or alternatively a pipline grinder or the like, through intake port  30 . The carbon black is dispersed in the aqueous carrier liquid to form a dispersion fluid which is passed through outlet port  31  and fluid line  33  to a homogenizer  34 . Pumping means  36 , preferably comprising a progressing cavity pump or the like is provided in line  33 . Homogenizer  34  more finely disperses the carbon black in the carrier liquid to form the carbon black slurry which is fed to the mixing zone of the coagulum reactor  14 . It has an inlet port  37  in fluid communication with line  33  from the colloid mill  32 . The homogenizer  34  may preferably comprise, for example, a Microfluidizer® system commercially available from Microfluidics International Corporation (Newton, Mass., USA). Also suitable are homogenizers such as models MS18, MS45 and MC120 Series homogenizers available from the APV Homogenizer Division of APV Gaulin, Inc. (Wilmington, Mass., USA). Other suitable homogenizers are commercially available and will be apparent to those skilled in the art given the benefit of the present disclosure. Typically, carbon black in water prepared in accordance with the above described system will have at least about 90% agglomerates less than about 30 microns, more preferably at least about 90% agglomerates less than about 20 microns in size. Preferably, the carbon black is broken down to an average size of 5-15 microns, e.g., about 9 microns. Exit port  38  passes the carbon black slurry from the homogenizer to the mixing zone through feed line  16 . The slurry may reach 10,000 to 15,000 psi in the homogenizer step and exit the homoginizer at about 600 psi or more. Preferably, a high carbon black content is used to reduce the task of removing excess water or other carrier. Typically, about 10 to 30 weight percent carbon black is preferred. Those skilled in the art will recognize, given the benefit of this disclosure, that the carbon black content (in weight percent) of the slurry and the slurry flow rate to the mixing zone should be coordinated with the natural rubber latex flow rate to the mixing zone to achieve a desired carbon black content (in phr) in the masterbatch. The carbon black content will be selected in accordance with known principles to achieve material characteristics and performance properties suited to the intended application of the product. Typically, for example, carbon blacks of CTAB value 10 or more are used in sufficient amount to achieve carbon black, content in the masterbatch of at least about 30 phr. 
     The slurry preferably is used in masterbatch production immediately upon being prepared. Fluid conduits carrying the slurry and any optional holding tanks and the like, should establish or maintain conditions which substantially preserve the dispersion of the carbon black in the slurry. That is, substantial reaglomeration or settling out of the particulate filler in the slurry should be prevented or reduced to the extent reasonably practical. Preferably all flow lines, for example, are smooth, with smooth line-to-line interconnections. Optionally, an accumulator is used between the homogenizer and the mixing zone to reduce fluctuations in pressure or velocity of the slurry at the slurry nozzle tip in the mixing zone. 
     Natural rubber latex fluid or other elastomer latex fluid passed to the mixing zone via feed line  12  and carbon black slurry fed to the mixing zone via feed line  16  under proper process parameters, as discussed above, can produce a novel elastomer composite, specifically, elastomer masterbatch crumb. Means may also be provided for incorporating various additives into the elastomer masterbatch. An additive fluid comprising one or more additives may be fed to the mixing zone as a separate feed stream. One or more additives also may be pre-mixed, if suitable, with the carbon black slurry or, more typically, with the elastomer latex fluid. Additives also can be mixed into the masterbatch subsequently, e.g., by dry mixing techniques. Numerous additives are well known to those skilled in the art and include, for example, antioxidants, antiozonants, plasticizers, processing aids (e.g., liquid polymers, oils and the like), resins, flame-retardants, extender oils, lubricants, and a mixture of any of them. The general use and selection of such additives is well known to those skilled in the art. Their use in the system disclosed here will be readily understood with the benefit of the present disclosure. In accordance with certain alternative embodiments, curative also can be incorporated in like manner, to produce a curable elastomer composite which may be referred to as a curable base compound. 
     The mixing zone/coagulum zone assembly is discussed in more detail below. The elastomer masterbatch crumb is passed from the discharge end of coagulum reactor  14  to suitable drying apparatus. In the preferred embodiment of  FIG. 1  the masterbatch crumb undergoes multi-stage drying. It is passed first to a de-watering extruder  40  and then via conveyor or simple gravity drop or other suitable means  41  to a drying extruder  42 . In routine preferred embodiments consistent with that illustrated in  FIG. 1  producing natural rubber masterbatch with carbon black filler, the de-watering/drying operation will typically reduce water content to about 0 to 1 weight percent, more preferably 0.0 to 0.5 weight percent. Suitable dryers are well known and commercially available, including for example, extruder dryers, fluid bed dryers, hot air or other oven dryers, and the like, such as French Mills available from the French Oil Machinery Co., (Piqua, Ohio, USA). 
     Dried masterbatch crumb from drying extruder  42  is carried by a cooling conveyor  44  to a baler  46 . The baler is an optional, advantageous feature of the apparatus of  FIG. 1 , wherein the dried masterbatch crumb is compressed within a chamber into form-stable compressed blocks or the like. Typically, 25 to 75 pound quantities of the elastomer masterbatch are compressed into blocks or bales for transport, further processing, etc. Alternatively, the product is provided as pellets, for example, by chopping the crumb. 
     The dimensions and particular design features of the coagulum reactor  14 , including the mixing zone/coagulum zone assembly, suitable for an embodiment in accordance with  FIG. 1 , will depend in part on such design factors as the desired throughput capacity, the selection of materials to be processed, etc. One preferred embodiment is illustrated in  FIG. 2  wherein a coagulum reactor  48  has a mix head  50  attached to a coagulum zone  52  with a fluid-tight seal at joint  54 .  FIG. 2  schematically illustrates a first subsystem  56  for feeding elastomer latex to the mixing zone, subsystem  57  for feeding carbon black slurry or other particulate filler fluid to the mixing zone, and subsystem  58  for feeding an optional additive fluid, pressurized air, etc. to the mixing zone. The mix head  50  is seen to have three feed channels  60 ,  61 ,  62 . Feed channel  60  is provided for the natural rubber latex fluid and feed channel  62  is provided for direct feed of gas and/or additive fluid. In connection with preferred embodiments employing direct injection of additives, significant advantage is achieved in connection with hydrocarbon additives or, more generally, non-water miscible additives. While it is well known to employ emulsion intermediates to create additive emulsions suitable for pre-blending with an elastomer latex, preferred embodiments in accordance with the present disclosure employing direct injection of additives can eliminate not only the need for emulsion intermediates, but also the equipment such as tanks, dispersing equipment, etc. previously used in forming the emulsions. Reductions in manufacturing cost and complexity can, therefore, be achieved. As discussed further below, the feed channel  61  through which slurry is fed to the mixing zone is preferably coaxial with the mixing zone and the coagulum zone of the coagulum reactor. While only a single feed channel is shown to receive the elastomer latex fluid, any suitable number of feed channels may be arranged around the central feed channel through which the slurry is fed to the mixing zone. Thus, for example, in the embodiment of  FIG. 2  a fourth feed channel could be provided through which ambient air or high pressure air or other gas is fed to the mixing zone. Pressurized air may be injected likewise with the slurry through the central axial feed channel  61 . Auxiliary feed channels can be temporarily or permanently sealed when not in use. 
     The coagulum zone  52  of the coagulum reactor  48  is seen to have a first portion  64  having an axial length which may be selected depending upon design objectives for the particular application intended. Optionally, the coagulum zone may have a constant cross-sectional area over all or substantially all of its axial length. Thus, for example, the coagulum reactor may define a simple, straight tubular flow channel from the mixing zone to the discharge end. Preferably, however, for reasons discussed above, and as seen in the preferred embodiment illustrated in the drawings, the cross-sectional area of the coagulum zone  52  increases progressively from the entry end  66  to discharge end  68 . More specifically, the cross-sectional area increases in the longitudinal direction from the entry end to the discharge end. In the embodiment of  FIG. 2 , the coagulum zone increases in cross-sectional area progressively in the sense that it increases continuously following constant cross-sectional portion  64 . References to the diameter and cross-sectional area of the coagulum reactor (or, more properly, the coagulum zone defined within the coagulum reactor) and other components, unless stated otherwise, are intended to mean the cross-sectional area of the open flow passageway and the inside diameter of such flow passageway. 
     Elastomer composite, specifically, coagulated elastomer latex in the form of masterbatch crumb  72 , is seen being discharged from the coagulum reactor  48  through a diverter  70 . Diverter  70  is an adjustable conduit attached to the coagulum reactor at discharge end  68 . It is adjustable so as to selectively pass the elastomer masterbatch crumb  72  to any of various different receiving sites. This feature advantageously facilitates removal of masterbatch crumb from the product stream, for example, for testing or at the beginning of a production run when initial process instability may result temporarily in inferior product. In addition, the diverter provides design flexibility to direct product from the coagulum reactor to different post-processing paths. In accordance with the preferred embodiment of  FIG. 1 , the masterbatch crumb  72  being discharged from coagulum reactor  48  through diverter  70  is seen to be received by a drier  40 . 
     The cross-sectional dimension of coagulum reactor  48  is seen to increase at an overall angle α between entry end  66  and discharge end  68 . Angle α is greater than 0° and in preferred embodiments is less than 45°, more preferably less than 15°, most preferably from 0.5° to 5°. The angle α is seen to be a half angle, in that it is measured from the central longitudinal axis of the coagulum zone to a point A at the outer circumference of the coagulum zone at the end of the coagulum reactor. In this regard, it should be understood that the cross-sectional area of the upstream portion of the coagulum reactor, that is, the portion near the entry end  66 , preferably increases sufficiently slowly to achieve quasi-molding of the coagulum in accordance with the principles discussed above. Too large an angle of expansion of the coagulum zone may result in the elastomer masterbatch not being produced in desirable crumb form of globules or worms and simply spraying through the coagulum reactor. Increasing the bore of the coagulum reactor too slowly can result, in certain embodiments, in backup or clogging of the feeds and reaction product into the mix head. In a downstream portion of the coagulum zone, wherein the latex has been substantially coagulated and flow has become essentially plug flow, the coagulum zone may extend either with or without increase in cross-sectional area. Thus, reference here to the coagulum zone in preferred embodiments having a progressively increasing cross-sectional area should be understood to refer primarily to that portion of the coagulum zone wherein flow is not substantially plug flow. 
     The cross-sectional area of the coagulum zone (that is, at least the upstream portion thereof as discussed immediately above) may increase in step-wise fashion, rather than in the continuous fashion illustrated in the embodiment of  FIG. 2 . In the embodiment illustrated in  FIG. 3 , a continuous flow system for production of elastomer masterbatch in accordance with the method and apparatus disclosed here, is seen to include a mix head/coagulum zone assembly wherein the cross-sectional area of the coagulum zone increases in step-wise fashion. Preferably, the individual sections of the coagulum zone in such a step-wise embodiment have a faired connection to adjacent sections. That is, they combine to form a smooth and generally continuous coagulum zone surface, as opposed, for example, to a sharp or instantaneous increase in diameter from one section to the next. The coagulum zone of  FIG. 3  increases in three steps, such that there are four different sections or sub-zones  74 - 77 . Consistent with the design principles discussed immediately above, the cross-sectional area of coagulum zone  53  increases from the entry end  66  to point A at the discharge end  68  at an overall angle which achieves the necessary flow control in the upstream portion of the coagulum reactor. The first section  74  can be taken as including (a) the constant diameter portion of the mix head  50  immediately downstream of the mixing zone, and (b) the same or similar diameter portion connected thereto at joint  54  at the entry end  66 . This first section has a constant cross-sectional diameter D 1  and an axial dimension or length L 1 . In this first section  74  the length L 1  should be greater than three times the diameter D 1 , more preferably greater than five times D 1 , and most preferably from about 12 to 18 times D 1 . Typically, this section will have a length of about fifteen times D 1 . Each subsequent section preferably has a constant cross-sectional dimension and cross-sectional area approximately double that of the preceding (i.e., upstream) section. Thus, for example, section  75  has a constant cross-sectional dimension and a cross-sectional area which is twice that of section  74 . Similarly, the cross-sectional area of section  76  is double that of section  75 , and the cross-sectional area of section  77  is double that of section  76 . In each of sections  75 - 77 , the length is preferably greater than three times its diameter, more preferably about three to seven times its diameter and generally about five times its diameter. Thus, for example, in section  76  longitudinal dimension L 3  is preferably about five times its diameter D 3.    
     A mix head and coagulum zone assembly corresponding to the embodiment of  FIG. 3  is shown in  FIG. 4  partially in section view. Mix head  50  is integral with coagulum zone extender  53  via joint  54 . It defines a mixing zone wherein multiple feed channels  60 ,  61 ,  62  form a junction, with an elongate, substantially cylindrical channel  80  substantially coaxial with the coagulum zone portion within extender  53 . It will be recognized that it is not essential to the operability of the method and apparatus disclosed here, to precisely define the boundaries of the mixing zone and/or coagulum zone. Numerous variations are possible in the design of the flow channels junction area, as will be apparent to those skilled in the art given the benefit of the present disclosure. In that regard, as a generally preferred guideline, in embodiments of the type illustrated in  FIG. 4 , for example, the slurry tip  67  generally is upstream of the beginning of cylindrical portion  80 , being approximately centered longitudinally in the junction of the feed channels. In such embodiments, preferably, the minimum cross-sectional area defined by the imaginary cone from the slurry tip  67  to the circumferential perimeter at the beginning of the cylindrical portion  80  is advantageously greater than, or at least equal to, the cross-sectional area of the latex feed channel  60 . Preferably, both channel  80  and at least the upstream portion of the coagulum zone wherein flow turbulence exists prior to substantially complete coagulation of the elastomer latex, have a circular cross-section. 
     The means for feeding carbon black slurry or other particulate filler fluid is seen to comprise a feed tube  82  extending substantially coaxially with the mixing chamber to an opening or slurry nozzle tip  67  which is open toward the coagulum zone. This is a highly advantageous feature of the preferred embodiments discussed here. The carbon black slurry, as noted above, is fed to the mixing zone at very high velocity relative the feed velocity of the latex, and the axial arrangement of narrow bore feed tube  82  results in excellent development of flow turbulence. The diameter D m  of the channel  80  (which, as noted above, is preferably substantially equal to the diameter D 1  of immediately following portion of section  74  of the coagulum zone) preferably is at least twice the inside diameter of slurry feed tube  82 , more preferably about four to eight times the diameter of feed tube  82 , typically about seven to eight times that diameter. Feed tube  82  is seen to form a fluid-tight seal with the entry port  83  at the upstream end of feed channel  61  of mix head  50 . The diameter of the axial feed tube  82  is determined largely by the required volumetric flow rate and axial velocity of the slurry as it passes through the slurry nozzle tip  67  into the mixing chamber. The correct or required volume and velocity can be readily determined by those skilled in the art given the benefit of this disclosure, and will be a function, in part, of the concentration and choice of materials. Embodiments such as that illustrated and disclosed here, wherein the feed tube for the carbon black slurry is removable, provide desirable flexibility in manufacturing different masterbatch compositions at different times. The feed tube used in one production run can be removed and replaced by a larger or smaller bore tube appropriate to a subsequent production. In view of the pressure and velocity at which the slurry exits the feed tube, it may be referred to as a spray or jet into the mixing zone. This should be understood to mean in at least certain embodiments, high speed injection of the slurry into an area already substantially filled with fluid. Thus, it is a spray in the sense of its immediate distribution as it passes through the slurry nozzle tip, and not necessarily in the sense of free-flying material droplets in a simple spreading trajectory. 
     The additional feed channels  60  and  62  are seen to form a junction  84 ,  85 , respectively, with feed channel  60  and downstream channel  80  at an angle β. The angle β may in many embodiments have a value from greater than 0° to less than 180°. Typically, β may be, for example, from 30°-90°. It is desirable to avoid a negative pressure, that is, cavitation of the latex fluid as it is entrained by the high velocity slurry exiting at slurry nozzle tip  67 , since this may disadvantageously cause inconsistent mixing leading to inconsistent masterbatch product. Air or other gas can be injected or otherwise fed to the mixing zone to assist in breaking any such vacuum. In addition, an expanded feed line for the natural rubber latex leading to the entry port  86  of feed channel  60  is desirable to act as a latex fluid reservoir. In the preferred embodiment of  FIG. 4 , latex feed channel  60  intersects the mixing zone adjacent slurry nozzle tip  67 . Alternatively, however, the latex feed channel can intersect the mixing channel upstream or downstream of the slurry nozzle tip  67 . 
     The carbon black slurry or other particulate filler fluid typically is supplied to feed tube  82  at a pressure above about 300 psig, such as about 500 to 5000 psig, e.g. about 1000 psig. Preferably the liquid slurry is fed into the mixing zone through the slurry nozzle tip  67  at a velocity above 100 ft. per second, preferably about 100 to about 800 ft. per second, more preferably about 200 to 500 ft. per second, for example, about 350 feet per second. Arrows  51  in  FIG. 4  represent the general direction of flow of the elastomer latex and auxiliary feed materials through feed channels  60  and  62  into the channel  80  below slurry nozzle tip  67 . Thus, the slurry and latex fluids are fed to the mixing zones at greatly different feed stream velocities, in accordance with the numbers set forth above. While not wishing to be bound by theory, it presently is understood that the differential feed achieves latex shear conditions in the mixing zone leading to good macro-dispersion and coagulation. 
     An alternative preferred embodiment is illustrated in  FIGS. 5 and 6  wherein the single axial feed tube  82  in the embodiment of  FIG. 4  is replaced by multiple axially extending feed tubes  90 - 92 . Even greater numbers of feed tubes may be employed, for example, up to about 6 or 8 axially-extending feed tubes. Advantageously, production flexibility is achieved by using different feed tubes of different diameter for production of different formulations. Also, multiple feed tubes can be used simultaneously to achieve good flow turbulence within the mixing zone and coagulum zone of the coagulum reactor. 
     An alternative embodiment of the mix head is illustrated in  FIG. 7 . Mix head  150  is seen to define a mixing zone  179 . An axial feed channel  161  receives a feed tube  182  adapted to feed carbon black slurry or other particulate filler fluid at high velocity into the mixing chamber  179 . It can be seen that the central bore in feed tube  182  terminates at slurry nozzle tip  167 . A constant diameter nozzle land  168  is immediately upstream of slurry nozzle tip  167 , leading to a larger bore area  169 . Preferably the axial dimension of land  168  is about 2 to 6, e.g. about 5, times its diameter. A second feed channel  160  forms a junction  184  with the mixing zone  179  at a 90° angle for feeding elastomer latex fluid to the mixing zone. The cross-sectional diameter of the latex fluid feed channel  160  is substantially larger than the cross-sectional diameter of the slurry nozzle tip  167  and land  168 . Without wishing to be bound by theory, the axial elongation of nozzle land  168 , coupled with the expanded diameter bore section upstream of the nozzle land, is believed to provide advantageous stability in the flow of slurry through feed tube  182  into the mixing zone  179 . The bore of feed tube  182  is found to function well with a 20° chamfer, that is, conical area  169  which expands in the upstream direction at about a 20° angle. Downstream of mixing zone  179  is an elongate coagulum zone. Consistent with the principles discussed above, such coagulum zone need be only marginally elongate. That is, its axial dimension need be only marginally longer than its diameter. Preferably, however, a progressively enlarged coagulum zone is used. 
     As discussed above, coagulation of the elastomer masterbatch is substantially complete at or before the end of the coagulum reactor. That is, coagulation occurs within the coagulum zone of the coagulum reactor without the necessity of adding a stream of coagulant solution or the like. This does not exclude the possibility that some initial coagulation occurs in the mixing zone. The mixing zone may be considered an extended portion of the coagulum zone for this purpose. Also, reference to substantially complete coagulation prior to the elastomer masterbatch exiting the coagulum reactor is not meant to exclude the possibility of subsequent processing and follow-on treatment steps, for any of various purposes appropriate to the intended use of the final product. In that regard, substantially complete coagulation in preferred embodiments of the novel method disclosed here employing natural rubber latex means that at least about 95 weight percent of the rubber hydrocarbon of the latex is coagulated, more preferably at least about 97 weight percent, and most preferably at least about 99 weight percent is coagulated. 
     The method and apparatus disclosed and described here produce elastomer composites having excellent physical properties and performance characteristics. Novel elastomer composites of the present invention include masterbatch compositions produced by the above-disclosed method and apparatus, as well as intermediate compounds and finished products made from such masterbatch compositions. Notably, elastomer masterbatch can be produced using natural rubber latex (latex concentrate or field latex), along with various grades of carbon black filler, having excellent physical properties and performance characteristics. Carbon blacks presently in broad commercial use for such application as tire tread have been used successfully, as well as carbon blacks heretofore considered unsuitable for commercial use in known production apparatus and methods. Those unsuitable because their high surface area and low structure rendered them impractical to achieve acceptable levels of macro-dispersion at routine commercial loading levels for the carbon black and/or to preserve the molecular weight of the elastomer are highly preferred for the novel elastomeric masterbatch compositions disclosed here. Such elastomer composites are found to have excellent dispersion of the carbon black in the natural rubber, together with good preservation of the molecular weight of the natural rubber. Moreover, these advantageous results were achieved without the need for a coagulation step involving a treatment tank or stream of acid solution or other coagulant. Thus, not only can the cost and complexity of such coagulant treatments be avoided, so too the need to handle effluent streams from such operations. 
     Prior known dry mastication techniques could not achieve equal dispersion of such fillers without significant molecular weight degradation and, therefore, could not produce the novel natural rubber masterbatch compositions made in accordance with certain preferred embodiments of the present invention. In that regard, novel elastomer composites are disclosed having excellent macro-dispersion of the carbon black in the natural rubber, even of carbon blacks having a structure to surface area ratio DBPA:CTAB less than 1.2 and even less than 1.0, with high molecular weight of the natural rubber. Known mixing techniques in the past did not achieve such excellent macro-dispersion of carbon black without significant molecular weight degradation of the natural rubber and, therefore, did not produce the novel masterbatch compositions and other elastomer composites of the present invention. Preferred novel elastomer masterbatch compositions in accordance with this disclosure, having carbon black macro-distribution levels not heretofore achieved, can be used in place of prior known masterbatch having poorer macro-dispersion. Thus, masterbatch disclosed here can be incorporated into cured compounds in accordance with known techniques. Such novel cured compounds are found in preferred embodiments to have physical characteristics and performance properties generally comparable to, and in some instances significantly better than, those of otherwise comparable cured compounds comprising masterbatch of poorer macro-dispersion. Masterbatch can be produced in accordance with the present invention, however, with reduced mixing time, reduced energy input, and/or other cost savings. 
     Particularly with respect to certain preferred embodiments, natural rubber latex and carbon black filler masterbatch can be produced having excellent physical characteristics and performance properties. Excellent macro-dispersion of the carbon black is achieved, even using carbon blacks of exceptionally high surface area and low structure, without the degree of degradation of the natural rubber which would be caused by dry mastication for sufficient time and at sufficient intensity levels to achieve the same degree of carbon black dispersion. Especially advantageous in this regard are novel natural rubber masterbatch compositions wherein a high degree of dispersion is achieved, using carbon blacks having structure to surface area ratio, DBPA:CTAB of less than 1.2 and even less than 1.9. As used here, the carbon black structure can be measured as the dibutyl phthalate adsorption (DBPA) value, expressed as cubic centimeters of DBPA per 100 grams carbon black, according to the procedure set forth in ASTM D2414. The carbon black surface area can be measured as CTAB expressed as square meters per gram of carbon black, according to the procedure set forth in ASTM D3765-85. Novel natural rubber masterbatch is achieved, therefore, having heretofore unachievable combinations of physical characteristics such as molecular weight distribution and filler dispersion levels, and/or incorporating heretofore unsuitable fillers such as carbon black of extraordinarily high surface area and low structure. The dispersion quality of natural rubber masterbatch produced in accordance with the methods and apparatus disclosed here can be demonstrated with reference to the well known characteristics of MW sol  (weight average) and macro-dispersion. Specifically, the macro-dispersion level in masterbatch produced in accordance with preferred embodiments is significantly better than that in masterbatch of approximately equal MW sol  produced using dry mastication. Most notably, the dispersion quality of these preferred embodiments does not depend significantly on the morphology of the carbon black filler. It will be recognized that other factors affecting the level of dispersion achievable using the method and apparatus disclosed here, include the concentration of the carbon black in the slurry, total energy input into the slurry and energy input during mixing of the fluid streams, etc. 
     The macro-dispersion quality of carbon black in natural rubber masterbatch disclosed here is significantly better than that in previously known masterbatch of approximately equal MW sol  (weight average). In some preferred embodiments of novel elastomer composites, excellent carbon black distribution is achieved with MW sol  approximately that of natural rubber in the field latex state, (e.g., approximately 1,000,000) a condition not previously achieved. The dispersion quality advantage is especially significant in the above mentioned preferred embodiments using carbon black with low structure and high surface area, e.g., DBPA less than 110 cc/100 g, CTAB greater than 45 to 65 m 2 /g, and DBPA:CTAB less than 1.2 and preferably less than 1.0. 
     EXAMPLES 
     Test Procedures 
     The following test procedures were used in the examples and comparisons presented below.
     1. Bound Rubber. A sample weighing 0.5 g.±0.025 g. is weighed and placed in 100 ml. toluene in a sealed flask and stored at ambient temperature for approximately 24 hours. The toluene is then replaced with 100 ml. fresh toluene and the flask is stored for 4 days. The sample is then removed from the solvent and air-dried under a hood at ambient temperature for 24 hours. The sample is then further dried in a vacuum oven at ambient temperature for 24 hours. The sample is then weighed and the bound rubber is calculated from the weight loss data.   2. MW sol : As used in this disclosure and in the claims, MW sol  refer to weight average molecular weight of the sol portion of the natural rubber. Standard GPC techniques for molecular weight measurement were followed in accordance with the following:
       2.1 Two 10 μm 10 6  Å columns, a 10 μm 500 Å column and a loom mixed bed column from Polymer Laboratories, UK.   2.2 UV detection at 215 nm.   2.3 Solvent: Tetra hydro furan (THF)   2.4 Concentration, nominally 2 mg/ml in THF.   2.5 Samples are left to dissolve in THF for 3 days, stabilized with BHT.   2.6 Solutions are centrifuged to separate any gel and the supernatant is injected onto the column.   2.7 Sample Preparations Sample preparation is designed to prepare sol concentrations in the range of 0.5 to 0.05 percent by weight to provide a good detector response for accurate measurement of the molecular weight distribution. Depending on the filler loading, sample weight is adjusted according to the following formula:
 
sample wt.=(100+filler loading(phr))*20/100 mg+/−2 mg
    Samples are placed in UV protected vials and dissolved in 4 mL of stabilized tetrahydrofuran (THF) containing 0.02% butylated-hydroxyltoluene (BHT) for three days. The supernatant from the dissolution step, containing mostly the sol portion, is transferred to Teflon centrifuge tubes and centrifuged in an Avanti 30 (Beckman) centrifuge for 60 minutes at 26,000 revolutions per minute (corresponding to a maximum field strength of 57,500 g). At this field strength, a majority of the gel phase sediments allowing a gel-free supernatant. This gel-free solution is diluted at 1:5, again using stabilized THF. At this point, the samples are transferred to GPC vials and placed inside a Waters 717 Auto-Sampler (Water Corporation, Milford, Mass., USA) in preparation for the GPC testing.    Molecular Weight Determination The weight average molecular weight of the sol portion MW sol  is then determined. Using Millenium software (available from Waters Corporation, Milford, Mass., USA) a baseline is defined using a valley-to-valley mode within the time increments of 15 and 35 minutes. This time increment is appropriate for the column set described above in paragraph 2.1 with the mobile phase flow rate set at 0.75 mL/min. Once a reasonable baseline is established the distribution can be determined. The elution time is converted to molecular weight. Polystyrene solutions made from commercially available standards (EasiCal: Polymer Laboratories, U.K.) are prepared containing a series of molecular weights with very narrow distributions. The conversion of polystyrene molecular weight to polyisoprene molecular weight equivalents is based on the universal calibration method of Benoit and coworkers. The hydrodynamic radius is proportional to the product of the molecular weight times the intrinsic viscosity. After converting the polystyrene molecular weights to polyisoprene equivalents, the calibration curve relates absolute molecular weight to elution time. The standards are run under conditions identical to the samples, and the standards are integrated to assign the appropriate molecular weight for a given elution time, based on a best fit to the standards data. Once the time based distribution is properly converted to molecular weight, the appropriate molecular weight averages are calculated by the Waters&#39; Millenium software.   
       3. Mooney Viscosity: Standard procedures were followed for ML (1+4)@100° C.
 
4. Test Sample Cure Conditions: Test pieces were cured to 150° C. for the time periods indicated below:
       4.1 Tensile Sheet: 20 min.   4.2 Resilience: 23 min.   4.3 Hardness: 23 min.   4.4 Heat Build-Up: 25 min.   
       5. Dispersion: The Cabot Dispersion Chart method is used with subjective evaluation of 50× optical micrographs. (ASTM D2663 Method).   6. Stress-Strain: Tested to BS903:A2 and ISO 37.   7. Hardness: Tested to ISO 48 (1994), temperature 23° C.   8. Resilience: Tested to BS903:A8 (1990), Method A, temperature 23° C. (8 mm molded disc test piece).   9. Heat Buildup: Tested to ASTM D623, Method A.
       9.1 Start temperature: 23° C.   9.2 Static load: 24 lbs.   9.3 Stroke: 0.225 inches.   9.4 Frequency: 30 Hz.   9.5 Run for 30 minutes.   
       10. Tan δ: Measured on Rheometrics® model RDS II. Reported values are maximums from strain sweeps. Strain sweeps at 0°, 30°, and 60° C., 1 Hz, and 0.1% to 60% strain.   11. Crack Growth Resistance: Measured in accordance with ASTM D3629-94   

     Example A 
     Elastomer masterbatch was produced in accordance with the present invention. Specifically, an elastomer masterbatch was produced comprising standard natural rubber field latex from Malaysia with 52.5 phr filler consisting of carbon black of commercial grade N234 available from Cabot Corporation. The properties of the natural rubber field latex are provided in Table 1 below. 
                     TABLE 1                  Natural Rubber Latex Properties                                                             Volatile               % Dry   % Total       Nitrogen   Fatty   ML(1 + 4)       Additives   Rubber   Solids   % Ash   ppm   Acid   @ 100 C.               0.15%   28.4   34.2   0.38   0.366   0.052   68       HNS a         0.3%       NH3,       ZnO,       TMTD b                   a HNS: hydroxylamine neutral sulfate, Mooney viscosity stabilizer.         b ZnO/TMTD: used for biological preservation, typically 0.025% of 1:1 mixture.            
The full compound formulation is set forth in Table 2 below, and is representative of a commercial truck tire tread known to have excellent resistance to reversion during cure.
 
                     TABLE 2                  Masterbatch Formulation                             Ingredient   Parts by Wt.                                         Rubber   100           Carbon Black   52.5           ZnO   4.0           Stearic acid   2.0           6PPD (antioxidant)   2.0           Sunproof Improved (wax)   2.0           Ennerflex 74 (aromatic oil)   3.0           Total   165.5                        
The elastomer masterbatch production apparatus was substantially identical to the apparatus described above with reference to  FIGS. 1 and 7  of the drawings. The slurry nozzle tip (see reference No. 167 in  FIG. 7 ) was 0.039 inch diameter with a land (see reference No. 168 in  FIG. 7 ) having an axial length of 0.2 inch. The coagulum zone was 0.188 inch diameter and had 0.985 inch axial length of constant diameter between the mixing zone and its discharge end. Preparation of the masterbatch is described in further detail immediately below.
     1. Carbon Black Slurry Preparation. Bags of carbon black were mixed with deionized water in a carbon black slurry tank equipped with an agitator. The agitator broke the pellets into fragments and a crude slurry was formed with 12.5 wt. % carbon black. During operation, this slurry was continually pumped by an air diaphragm pump to a colloid mill for initial dispersion. The slurry was then fed by a progressing cavity pump to a homogenizer, specifically, a model M3 homogenizer from APV Gaulin, Inc. The homogenizer produced a finely ground slurry. The slurry flow rate from the homogenizer to the mixing zone was set by the homogenizer speed, the homogenizer acting as a high-pressure positive displacement pump. Slurry flow rate was monitored with a Micromotion®g mass flow meter. The carbon black slurry was fed to the homogenizer at a pressure ranging from 50 to 100 psig and the homogenization pressure was set at 4000 psig, such that the slurry was introduced as a jet into the mixing zone at a flow rate of 4.1 to 4.4 lb/min and at a velocity of about 130 ft/sec.   2. Latex Delivery. The latex was charged to a 100 gallon pressurized feed tank. Antioxidant emulsion was added to the latex prior to charging. Antioxidants were added consisting of 0.3 phr tris nonyl phenyl phosphite (TNPP) and 0.4 phr Santoflex® 134 (alkyl-aryl p-phenylene diamine mixture). Each of the antioxidants was prepared as a 15 wt. % emulsion using 3 parts potassium oleate per 100 parts antioxidant along with potassium hydroxide to adjust the emulsion to a pH of approximately 10. Also, 3 phr extender oil was added. Air pressure (51 psig) was used to move the latex from the feed tank to the mixing zone of the coagulum reactor. The latex flow rate was 3.2 to 3.4 lbs/min and about 3.8 feet per second, and was automatically metered and controlled with a Micromotion® mass flow meter and a rubber tube pinch valve. The desired carbon black loading of a 52.5 phr was obtained by maintaining proper ratio of the latex feed rate to the carbon black slurry feed rate.   3. Carbon Black and Latex Mixing. The carbon black slurry and latex were mixed by entraining the latex into the carbon black slurry. During entrainment, the carbon black was intimately mixed into the latex and the mixture coagulated. Soft, wet spongy “worms” of coagulum exited the coagulum reactor.   4. Dewatering. The wet crumb discharged from the coagulum reactor was about 79%-water. The wet crumb was dewatered to about 5 to 10% moisture with a dewatering extruder (The French Oil Mill Machinery Company; 3½ in. diameter). In the extruder, the wet crumb was compressed and water squeezed from the crumb and through a slotted barrel of the extruder.   5. Drying &amp; Cooling. The dewatered crumb dropped into a second extruder where it was again compressed and heated. Water was flashed off upon expulsion of the crumb through the dieplate of the extruder. Product exit temperature was approximately 300° F. and moisture content was about 0.5 to 1 wt. %. The hot, dry crumb was rapidly cooled (approximately 20 seconds) to about 100° F. by a forced air vibrating conveyor. The resulting dry crumb had about 66. wt. % rubber solids and about 33. wt. % carbon black.   
     Example B 
     A control masterbatch was prepared by dry mastication. The control employed the same formulation as Example A (see Table 2 above), except that the natural rubber was SMR 10 rather than latex. It was prepared by premastication of the rubber in a OOC Banbury mixer (approximately 3 kg) at 50 rpm using 10 phr carbon black. The premastication was performed for approximately 3 min. to a total of 800 MJ/m 3 . 
     Comparisons of Example A and Example B 
     The masterbatch of Example A and the control masterbatch of Example B were compounded in a two-stage mixing operation in a OOC Banbury mixer (approximately 3 kg). Table 3 below sets forth the mixing schedule for the first stage. It can be seen that the Example A masterbatch followed a modified mixing schedule. 
                     TABLE 3                  Stage 1 Mixing Schedules                         Time       Example B       (min)   Example A   Dry Mix Control               0.0   All ingredients   Pre-Masticated Rubber       0.5       Carbon Black and Oil       1.0   Sweep       1.5       Remaining Ingredients       2.0       2.5       Sweep       3.0       X   dump at approx. 700 MJ/m 3     dump at approx. 1,000 MJ/m 3                      
In the second stage, curatives listed in Table 4 below were added with a further mixing cycle of 500 MJ/m 3 .
 
                     TABLE 4                  Final Stage Curative Addition                             Ingredient   Parts by Wt.                                         Stage 1 compound   165.5           Goodyear Winstay 100 (antioxidant)   1.0           TBBS (sulfur accelerator)   1.8           Sulfur   1.0           Total   169.3                        
Thus, Banbury mixing energy for the compounding of Example A masterbatch was about 53% of the Banbury mixing energy required for the premastication and compounding of the control material of Example B. Despite the reduced energy input, the Example A material was found to have very good macro-dispersion, and the molecular weight (weight average) of its sol portion MW sol  was substantially higher than that of the control. These data are summarized in Table 5 below.
 
                     TABLE 5                  Compounding and Curing Data                                 Mix Energy (MJ/m 3 )   ML (1 + 4,                                         Pre-       100 C.)   MW                                             Sample   Masticate   Stage 1   Final   Total   Stage 1   Final   wt. av.                                                     Example   0   694   500   1,194   102   72   444,900       A       Example   800   965   500   2,265   92   67   327,000       B                    
Additional testing results for the cured (unaged) Example A and control material are set forth in Table 6 below.
 
     
       
         
           
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 Additional Test Data 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 100% Modulus 
                 300% Modulus 
                   
               
               
                 Sample 
                 Hardness 
                 (MPa) 
                 (MPa) 
                 Tensile (MPa) 
               
               
                   
               
               
                 Example 
                 71 
                 2.82 
                 16.1 
                 28.7 
               
               
                 A 
               
               
                 Example 
                 72 
                 3.12 
                 16.2 
                 28.5 
               
               
                 B 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 Elongation 
                   
                 Heat 
                   
               
               
                   
                 at 
                 Resiliance 
                 Build-Up 
                 Max Tan Delta 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Sample 
                 Break (%) 
                 (%) 
                 (° C.) 
                 60° C. 
                 30° C. 
                 0° C. 
               
               
                   
               
               
                 Example 
                 526 
                 56.5 
                 70.5 
                 0.203 
                 0.240 
                 0.290 
               
               
                 A 
               
               
                 Example 
                 511 
                 57.6 
                 76.5 
                 0.206 
                 0.236 
                 0.286 
               
               
                 B 
               
               
                   
               
            
           
         
       
     
     Example C 
     Elastomer masterbatch was produced in accordance with the present invention. Specifically, an elastomer masterbatch was produced comprising standard natural rubber field latex from Malaysia with 55 phr filler consisting of carbon black of commercial grade Regal® 660 available from Cabot Corporation. The compound formulation (excluding minor ordinary latex additives) is set forth in Table 7 below. 
                     TABLE 7                  Masterbatch Formulation                             Ingredient   Parts by Wt.                                         Rubber   100           Carbon Black   55.           Santoflex 134 (antioxidant)   0.4           TNPP (antioxidant)   0.3           Total   155.7                        
The elastomer masterbatch production apparatus was substantially identical to the apparatus described above with reference to  FIGS. 1 ,  3  and  7  of the drawings. The slurry nozzle tip (see reference No. 167 in  FIG. 7 ) was 0.025 inch diameter with a land (see reference No. 168 in  FIG. 7 ) having an axial length of 0.2 inch. The coagulum zone (see No. 53 in  FIG. 3 ) included a first portion of 0.188 inch diameter and approximately 0.985 inch axial length (being partly within the mix-head and party within the extender sealed thereto); a second portion of 0.266 inch diameter and 1.6 inch axial length; a third portion of 0.376 inch diameter and 2.256 axial length; and a fourth portion of 0.532 inch diameter and 3.190 inch axial length. In addition, there are axially short, faired interconnections between the aforesaid portions. Preparation of the masterbatch is described in further detail immediately below.
     1. Carbon Black Slurry Preparation. Bags of carbon black were mixed with deionized water in a carbon black slurry tank equipped with an agitator. The agitator broke the pellets into fragments and a crude slurry was formed with 14.9 wt. % carbon black. The crude slurry was recirculated using a pipeline grinder. During operation, this slurry was continually pumped by an air diaphragm pump to a colloid mill for initial dispersion. The slurry was then fed by a progressing cavity pump to a homogenizer, specifically, Microfluidizer Model M210 from Microfluidics International Corporation for pressurizing and shear, to produce a finely ground slurry. The slurry flow rate from the microfluidizer to the mixing zone was set by the microfluidizer speed, the microfluidizer acting as a high-pressure positive displacement pump. Slurry flow rate was monitored with a Micromotion® mass flow meter. The carbon black slurry was fed to the microfluidizer at a pressure of about 130 psig and the output pressure was set at 3000 psig to an accumulator set at 450 psig output pressure, such that the slurry was introduced as a jet into the mixing zone at a flow rate of about 3.9 lb/min and at a velocity of about 300 ft/sec.   2. Latex Delivery. The latex was charged to a tank, specifically, a 55 gallon feed drum. Antioxidant emulsion was added to the latex prior to charging. Antioxidants were added consisting of 0.3 phr tris nonyl phenyl phosphite (TNPP) and 0.4 phr Santoplex® 134 (alkyl-aryl p-phenylene diamine mixture). Each of the antioxidants was prepared as a 40 wt. % emulsion using 4 parts potassium oleate per 100 parts antioxidant along with potassium hydroxide to adjust the emulsion to a pH of approximately 10. A peristaltic pump was used to move the latex from the feed tank to the mixing zone of the coagulum reactor. The latex flow rate was 3.2 to 3.3 lbs/min and about 3.9 feet per second, and was metered with a Endress+Hauser (Greenwood, Ind., USA) mass flow meter. The desired carbon black loading of a 55 phr was obtained by maintaining proper ratio of the latex feed rate to the carbon black slurry feed rate.   3. Carbon Black and Latex Mixing. The carbon black slurry and latex were mixed by entraining the latex into the carbon black slurry. During entrainment, the carbon black was intimately mixed into the latex and the mixture coagulated. Soft, wet spongy “worms” of coagulum exited the coagulum reactor.   4. Dewatering The wet crumb discharged from the coagulum reactor was about 78% water. The wet crumb was dewatered to about 12 to 13% moisture with a dewatering extruder (The French Oil Mill Machinery Company; 3½ in. diameter). In the extruder, the wet crumb was compressed and water squeezed from the crumb and through a slotted barrel of the extruder.   5. Drying &amp; Cooling. The dewatered crumb dropped into a second extruder where it was again compressed and heated. Water was flashed off upon expulsion of the crumb through the dieplate of the extruder. Product exit temperature was approximately 280° F. to 370° F. and moisture content was about 0.3 to 0.4 wt. %. The hot, dry crumb was rapidly cooled (approximately 20 seconds) to about 100° F. by a forced air vibrating conveyor.   
     Examples D and E 
     Two dry mix control masterbatches were prepared by dry mastication. The controls employed the same formulation as Example C (see Table 7 above), except that in Example D the rubber was RSS1 NR rather than latex. In Example E the rubber was SMR 10 NR. Each was prepared by premastication of the rubber in a BR Banbury mixer. The rubber of Example D was masticated at 118 rpm for 10 minutes. The rubber of Example E was masticated at 77 rpm for 4 minutes. 
     Comparison of Examples C, D and E 
     The masterbatch of Example C and the two control masterbatches of Example D and E were compounded in a BR Banbury mixer. Table 8 below sets forth the compounding schedules. 
                     TABLE 8                  Compounding Schedules                                         Stage II (Final)       Masterbatch   Pre-Mastication   Stage I Mixing   Mixing               Example C   No   No   BR Banbury 77 rpm,                   4.5 min.       Example D   BR Banbury   BR Banbury   BR Banbury 77 rpm,           mixer 118 rpm,   mixer 77 rpm,   4.5 min.           10 min.   3 min.       Example E   BR Banbury   BR Banbury   BR Banbury 77 rpm,           mixer 77 rpm,   mixer 77 rpm,   4.5 min.           4 min.   8 min.                    
The compounding formulation is given in Table 9 below.
 
                     TABLE 9                  Stage II Curative Addition                             Ingredient   Parts by Wt.                                         Example 4 Masterbatch or   155           Example 5 or 6 Stage 1 Dry Mix           Azo 66 (zinc oxide)   4.0           Hystrene 5016 (stearic acid)   2.0           Santoflex 13 (antioxidant)   2.0           Sunproof Improved (wax)   2.0           Wingstay 100 (antioxidant)   1.0           Santocure NS (sulfur accelerator)   1.8           Sulfur   1.0           Total:   168.8                        
All three compounds exhibited well-behaved cure with minimal reversion. Despite the reduced energy input, the Example C material was found to have significantly better macro-dispersion than the dry mix controls, and the molecular weight (weight average) of its sol portion MW sol  was substantially higher than that of the controls. These data are summarized in Table 10 below.
 
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 Masterbatch and Compound Properties 
               
            
           
           
               
               
               
               
            
               
                   
                 Example C 
                 Example D 
                 Example E 
               
               
                   
                   
               
            
           
           
               
            
               
                 Masterbatch Properties 
               
            
           
           
               
               
               
               
            
               
                 Mooney Viscosity 
                 125 
                 124 
                 126 
               
               
                 ML(1 + 4) @ 100 C. 
               
               
                 Bound Rubber 
                 50 
                 32 
                 44 
               
               
                 (%) 
               
               
                 MW sol (×10 −6 ) 
                 0.678 
                 .466 
                 .463 
               
               
                 Percent 
                 .12 
                 1.48 
                 2.82 
               
               
                 Undispersed Area 
               
               
                 (D %) 
               
            
           
           
               
            
               
                 Compound Properties 
               
            
           
           
               
               
               
               
            
               
                 Hardness 
                 62 
                 65 
                 62 
               
               
                 100% Modulus 
                 239 
                 315 
                 270 
               
               
                 (psi) 
               
               
                 300% Modulus 
                 1087 
                 1262 
                 1216 
               
               
                 (psi) 
               
               
                 Tensile strength 
                 4462 
                 4099 
                 4344 
               
               
                 (psi) 
               
               
                 Elongation, % 
                 675 
                 591 
                 600 
               
               
                 Max. Tan Delta 
                 0.189 
                 .237 
                 .184 
               
               
                 @ 60 C. (Strain 
               
               
                 Sweep) 
               
               
                 Crack Growth 
                 0.8 
                 5.0 
                 5.8 
               
               
                 Rate 
               
               
                 (cm/per million 
               
               
                 cycles) 
               
               
                   
               
            
           
         
       
     
     Additional Examples and Comparisons 
     Highly preferred elastomer composites in accordance with the present invention were produced in accordance with the method and apparatus disclosed above. In particular, novel masterbatch compositions were formed of natural rubber latex and carbon black filler, having significantly better macro-dispersion levels and/or natural rubber molecular weight than heretofore found in known compositions formed of the same or similar starting materials.  FIG. 8  shows the surface area and structure of various carbon black fillers used in these preferred masterbatch compositions, specifically, the CTAB surface area expressed as square meters per gram of carbon black per ASTM D3765-85 and dibutyl phthalate absorption (DBPA) value expressed as cubic centimeters of DBP per hundred grams carbon black per ASTM D2414 are shown.  FIG. 8  is seen to be divided into three different regions of carbon blacks. Region I contains carbon blacks having lower structure and higher surface area, being those most difficult to disperse in natural rubber and other elastomers using traditional dry mixing techniques. Hence, carbon blacks of Region I are not used commercially as widely as other carbon blacks. Masterbatch and cured elastomeric compositions made with Region I carbon blacks using traditional dry mixing techniques have poorer macro-dispersion and typically lower MW sol . The carbon blacks of Region II have higher structure than those of Region I. Typically, they achieve reasonably good dispersion in natural rubber for vehicle tire products and the like if subjected to such extended dry mixing that the MW sol  of the natural rubber is significantly degraded. The carbon blacks of Region III of  FIG. 8  have lower surface area relative their structure. Accordingly they have been used with acceptable dispersion in natural rubber via dry mixing, but again, with undesirable degradation of MW sol . The dispersion of carbon blacks of all three regions of  FIG. 8 , specifically, macro-dispersion, is significantly improved in the elastomer composites disclosed here, and can be achieved with significantly higher MW sol  of the natural rubber in accordance with preferred embodiments. 
     Control Samples 1-443 
     Control samples of masterbatch were prepared by dry mixing in accordance with the following procedures, for purposes of comparison to elastomer composites of the present invention.
     1. Mastication of Natural Rubber   

     In order to produce dry masterbatches with a wide range of molecular weight, commercial natural rubber (RSS1, SMR CV, and SMR 10) bales were pre-masticated in a BR banbury mixer using the following conditions (fill factor: 0.75): 
     
       
         
           
               
             
               
                 TABLE 11 
               
             
            
               
                   
               
               
                 Natural Rubber Mastication Conditions 
               
            
           
           
               
               
               
               
               
            
               
                 Sample 
                   
                 Rotor Speed 
                 Cooling 
                 Mastication 
               
               
                 Code 
                 Mastication 
                 (rpm) 
                 Water 
                 time (min.) 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 M1 
                 No 
                   
                   
                   
               
               
                 M2 
                 Yes 
                 77 
                 On 
                 4 
               
               
                 M3 
                 Yes 
                 118 
                 On 
                 6 
               
               
                 M4 
                 Yes 
                 118 
                 On 
                 10 
               
               
                   
               
            
           
         
       
         
         2. Mixing Carbon Black with Pre-Masticated Natural Rubber 
       
    
     In order to prepare natural rubber dry masterbatches with different levels of macro-dispersion quality, the following mixing procedures were used in a BR Banbury mixer. The fill factor was 0.70. The masterbatch ingredients and mixing procedures are described as follows in Table 12. 
                     TABLE 12                  Natural Rubber Dry Masterbatch Formulation                                 phr               (Parts per hundred parts of rubber by           Ingredient   weight)                                         Natural Rubber   100           Carbon Black   See Tables Below           Oil   See Tables Below           Santofex (antioxidant)   0.4           TNPP (antioxidant)   0.3                       Mixing Procedures:           0 minute: Add pre-masticated natural rubber (77 rpm, 45 C.)           1 minute: Add black, oil and antioxidants            
Different levels of macro-dispersion were produced by dry mixing samples of M1 through M4 pre-masticated natural rubber for different mixing times, as shown in Table 13, below. For example, sample code M2D1 in Table 13 indicates a control sample of premasticated natural rubber M2 (see Table 11, above) mixed for 10 minutes in accordance with the formulation of Table 12.
 
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 Mixing Times 
               
            
           
           
               
               
               
            
               
                 Dry NR Masterbatch 
                   
                   
               
               
                 Sample Code 
                 Pre-Masticated NR 
                 Mixing Time 
               
               
                   
               
            
           
           
               
               
               
            
               
                 M1D4 
                 M1 
                 4 
               
               
                 M1D3 
                 M1 
                 6 
               
               
                 M1D2 
                 M1 
                 8 
               
               
                 M1D1 
                 M1 
                 10 
               
               
                 M2D4 
                 M2 
                 4 
               
               
                 M2D3 
                 M2 
                 6 
               
               
                 M2D2 
                 M2 
                 8 
               
               
                 M2D1 
                 M2 
                 10 
               
               
                 M3D4 
                 M3 
                 4 
               
               
                 M3D3 
                 M3 
                 6 
               
               
                 M3D2 
                 M3 
                 8 
               
               
                 M3D1 
                 M3 
                 10 
               
               
                 M4D4 
                 M4 
                 4 
               
               
                 M4D3 
                 M4 
                 6 
               
               
                 M4D2 
                 M4 
                 8 
               
               
                 M4D1 
                 M4 
                 10 
               
               
                   
               
            
           
         
       
         
         3. Final Mixing of Natural Rubber Masterbatch Control Samples 
       
    
     To evaluate compound performance, additional ingredients were added to the dry masticated natural rubber masterbatch control samples of Table 13 in accordance with the formulation shown in Table 14. 
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 Additional Ingredients for Final Mixing 
               
            
           
           
               
               
               
            
               
                   
                 Ingredient 
                 Amount (phr) 
               
               
                   
                   
               
               
                   
                 Azo 66 (zinc oxide) 
                 4.0 
               
               
                   
                 Hystere 5016 (stearic acid) 
                 2.0 
               
               
                   
                 Santoflex 13 (antioxidant) 
                 2.0 
               
               
                   
                 Sunproof Improved (wax) 
                 2.0 
               
               
                   
                 Wingstay 100 (antioxidant) 
                 1.0 
               
               
                   
                 Santocure NS (sulfur accelerator) 
                 1.8 
               
               
                   
                 Sulfur 
                 1.0 
               
               
                   
                   
               
            
           
         
       
     
     The compounds were cured in accordance with standard cure techniques at 150° C. until at least substantially completely cured, typically between 10 and 30 minutes. In that regard, the same or substantially the same final mixing procedures, including the formulation given above in Table 14, were used for all control samples, as well as all samples of elastomer composites of the invention prepared in the manner described below (see “Preferred Embodiments Examples) which were cured and tested for compound properties and performance characteristics. 
     The following tables 15-23 set forth the sol molecular weight MW sol  and macro-dispersion D(%) of control samples 1 through 443. The samples are grouped in the tables according to choice of carbon black. Within a given table, the samples are grouped by choice of natural rubber and by carbon black loading and oil loading. The table headings show this information in accordance with standard nomenclature. Thus, for example, the heading for Table 15 “N330/55 phr/0” indicates 55 phr N330 carbon black with no oil. The table sub-headings show the choice of natural rubber. Specifically, control samples 1 through 450 are seen to be made from standard grade natural rubber RSS1, SMRCV and SMR10. Technical description of these natural rubbers is widely available, such as in Rubber World Magazine&#39;s Blue Book published by Lippincott and Peto, Inc. (Akron, Ohio, USA). The molecular weight MW sol  of the natural rubber prior to any premastication (M1) and after the various amounts of premastication (M2-M4) also are shown below in Tables 15-23. 
     
       
         
           
               
               
             
               
                   
                 TABLE 15 
               
             
            
               
                   
                   
               
               
                   
                 N330/55 phr/0 
               
            
           
           
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1300  
                   
                   
                 971 
                   
               
               
                 M2 
                   
                 932 
                   
                   
                 725 
               
               
                 M3 
                   
                 664 
                   
                   
                 596 
               
               
                 M4 
                   
                 485 
                   
                   
                 482 
               
               
                 M1D1 
                 1 
                 465 
                 4.24 
                 17 
                 426 
                 4.35 
               
               
                 M1D2 
                 2 
                 571 
                 3.70 
                 18 
                 467 
                 3.89 
               
               
                 M1D3 
                 3 
                 706 
                 4.79 
                 19 
                 486 
                 4.86 
               
               
                 M1D4 
                 4 
                 770 
                 4.52 
                 20 
                 535 
                 4.78 
               
               
                 M2D1 
                 5 
                 445 
                 3.66 
                 21 
                 380 
                 2.44 
               
               
                 M2D2 
                 6 
                 490 
                 2.68 
                 22 
                 398 
                 3.71 
               
               
                 M2D3 
                 7 
                 512 
                 3.68 
                 23 
                 433 
                 4.30 
               
               
                 M2D4 
                 8 
                 581 
                 3.93 
                 24 
                 498 
                 5.81 
               
               
                 M3D1 
                 9 
                 373 
                 1.33 
                 25 
                 342 
                 3.79 
               
               
                 M3D2 
                 10 
                 402 
                 2.50 
                 26 
                 358 
                 4.35 
               
               
                 M3D3 
                 11 
                 407 
                 2.98 
                 27 
                 371 
                 5.55 
               
               
                 M3D4 
                 12 
                 452 
                 3.35 
                 28 
                 408 
                 5.01 
               
               
                 M4D1 
                 13 
                 311 
                 3.63 
                 29 
                 311 
                 3.66 
               
               
                 M4D2 
                 14 
                 337 
                 3.40 
                 30 
                 325 
                 5.31 
               
               
                 M4D3 
                 15 
                 362 
                 5.03 
                 31 
                 344 
                 5.91 
               
               
                 M4D4 
                 16 
                 382 
                 5.23 
                 32 
                 369 
                 5.67 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 16 
               
             
            
               
                   
                   
               
               
                   
                 Black Pearl 800/55 phr/0 
               
            
           
           
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1041 
                   
                   
                 869 
                   
               
               
                 M2 
                   
                 786 
                   
                   
                 662 
               
               
                 M3 
                   
                 663 
                   
                   
                 491 
               
               
                 M4 
                   
                 527 
                   
                   
                 420 
               
               
                 M1D1 
                 113 
                 507 
                 12.20 
                 129 
                 418 
                 5.15 
               
               
                 M1D2 
                 114 
                 551 
                 15.10 
                 130 
                 482 
                 4.94 
               
               
                 M1D3 
                 115 
                 700 
                 10.20 
                 131 
                 515 
                 6.93 
               
               
                 M1D4 
                 116 
                 786 
                 5.72 
                 132 
                 583 
                 8.74 
               
               
                 M2D1 
                 117 
                 420 
                 5.65 
                 133 
                 403 
                 2.60 
               
               
                 M2D2 
                 118 
                 441 
                 6.50 
                 134 
                 438 
                 2.74 
               
               
                 M2D3 
                 119 
                 549 
                 7.70 
                 135 
                 434 
                 2.83 
               
               
                 M2D4 
                 120 
                 606 
                 5.88 
                 136 
                 530 
                 3.88 
               
               
                 M3D1 
                 121 
                 387 
                 3.26 
                 137 
                 366 
                 2.38 
               
               
                 M3D2 
                 122 
                 409 
                 2.98 
                 138 
                 378 
                 2.83 
               
               
                 M3D3 
                 123 
                 456 
                 3.61 
                 139 
                 399 
                 3.04 
               
               
                 M3D4 
                 124 
                 483 
                 4.61 
                 140 
                 431 
                 2.39 
               
               
                 M4D1 
                 125 
                 339 
                 2.13 
                 141 
                 311 
                 2.22 
               
               
                 M4D2 
                 126 
                 367 
                 2.23 
                 142 
                 332 
                 2.27 
               
               
                 M4D3 
                 127 
                 360 
                 2.60 
                 143 
                 344 
                 2.27 
               
               
                 M4D4 
                 128 
                 403 
                 1.96 
                 144 
                 390 
                 2.73 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 17 
               
             
            
               
                   
                   
               
               
                   
                 N351/33 phr/20 phr 
               
               
                   
                 RSS1 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Sample 
                 Mw sol   
                   
               
               
                   
                 Code 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 M1 
                   
                 1300 
                   
               
               
                   
                 M2 
                   
                 803 
               
               
                   
                 M3 
                   
                 601 
               
               
                   
                 M1D1 
                 401 
                 854 
                 2.08 
               
               
                   
                 M1D2 
                 402 
                 969 
                 3.41 
               
               
                   
                 M1D3 
                 403 
                 1040 
                 3.68 
               
               
                   
                 M1D4 
                 404 
                 1130 
                 4.91 
               
               
                   
                 M2D1 
                 405 
                 648 
                 1.15 
               
               
                   
                 M2D2 
                 406 
                 668 
                 2.16 
               
               
                   
                 M2D3 
                 407 
                 675 
                 2.98 
               
               
                   
                 M2D4 
                 408 
                 721 
                 4.70 
               
               
                   
                 M3D1 
                 409 
                 532 
                 1.10 
               
               
                   
                 M3D2 
                 410 
                 537 
                 2.17 
               
               
                   
                 M3D3 
                 411 
                 535 
                 2.45 
               
               
                   
                 M3D4 
                 412 
                 558 
                 4.06 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 18A 
               
             
            
               
                   
                   
               
               
                   
                 Regal 250/55 phr/0 
               
            
           
           
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1332 
                   
                   
                 1023 
                   
               
               
                 M2 
                   
                 896 
                   
                   
                 748 
               
               
                 M3 
                   
                 603 
                   
                   
                 581 
               
               
                 M4 
                   
                 408 
                   
                   
                 504 
               
               
                 M1D1 
                 33 
                 585 
                 6.95 
                 49 
                 609 
                 1.93 
               
               
                 M1D2 
                 34 
                 669 
                 8.03 
                 50 
                 634 
                 3.29 
               
               
                 M1D3 
                 35 
                 759 
                 10.5 
                 51 
                 681 
                 2.21 
               
               
                 M1D4 
                 36 
                 896 
                 14.1 
                 52 
                 702 
                 4.09 
               
               
                 M2D1 
                 37 
                 580 
                 2.71 
                 53 
                 539 
                 2.14 
               
               
                 M2D2 
                 38 
                 602 
                 2.61 
                 54 
                 569 
                 2.72 
               
               
                 M2D3 
                 39 
                 631 
                 3.61 
                 55 
                 587 
                 4.75 
               
               
                 M2D4 
                 40 
                 667 
                 5.43 
                 56 
                 595 
                 6.25 
               
               
                 M3D1 
                 41 
                 457 
                 1.53 
                 57 
                 466 
                 2.88 
               
               
                 M3D2 
                 42 
                 476 
                 2.09 
                 58 
                 449 
                 3.19 
               
               
                 M3D3 
                 43 
                 493 
                 2.32 
                 59 
                 464 
                 4.53 
               
               
                 M3D4 
                 44 
                 495 
                 3.54 
                 60 
                 500 
                 5.89 
               
               
                 M4D1 
                 45 
                 372 
                 1.53 
                 61 
                 423 
                 2.89 
               
               
                 M4D2 
                 46 
                 382 
                 2.09 
                 62 
                 433 
                 3.42 
               
               
                 M4D3 
                 47 
                 381 
                 2.32 
                 63 
                 437 
                 4.39 
               
               
                 M4D4 
                 48 
                 403 
                 3.54 
                 64 
                 447 
                 4.73 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 18B 
               
             
            
               
                   
                   
               
               
                   
                 Regal 250/65/0 
                 Regal 250/75/0 
                 Regal 250/65/10 
               
               
                   
                 RSS1 
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1138 
                   
                   
                 1138 
                   
                   
                 1138 
                   
               
               
                 M2 
                   
                 901 
                   
                   
                 901 
                   
                   
                 901 
               
               
                 M3 
                   
                 660 
                   
                   
                 660 
                   
                   
                 660 
               
               
                 M4 
                   
                 483 
                   
                   
                 483 
                   
                   
                 483 
               
               
                 M1D1 
                 65 
                 570 
                 1.50 
                 81 
                 539 
                 2.87 
                 97 
                 661 
                 1.89 
               
               
                 M1D2 
                 66 
                 622 
                 3.25 
                 82 
                 624 
                 4.50 
                 98 
                 702 
                 2.69 
               
               
                 M1D3 
                 67 
                 707 
                 7.50 
                 83 
                 685 
                 4.17 
                 99 
                 741 
                 3.14 
               
               
                 M1D4 
                 68 
                 788 
                 4.77 
                 84 
                 763 
                 14.35 
                 100 
                 822 
                 5.24 
               
               
                 M2D1 
                 69 
                 534 
                 1.62 
                 85 
                 484 
                 4.32 
                 101 
                 593 
                 0.91 
               
               
                 M2D2 
                 70 
                 548 
                 4.19 
                 86 
                 512 
                 2.96 
                 102 
                 572 
                 3.48 
               
               
                 M2D3 
                 71 
                 585 
                 4.31 
                 87 
                 557 
                 4.71 
                 103 
                 642 
                 4.23 
               
               
                 M2D4 
                 72 
                 621 
                 6.21 
                 88 
                 605 
                 4.85 
                 104 
                 664 
                 5.35 
               
               
                 M3D1 
                 73 
                 459 
                 3.64 
                 89 
                 429 
                 2.27 
                 105 
                 507 
                 2.65 
               
               
                 M3D2 
                 74 
                 469 
                 5.79 
                 90 
                 446 
                 2.68 
                 106 
                 544 
                 2.96 
               
               
                 M3D3 
                 75 
                 511 
                 5.30 
                 91 
                 466 
                 3.46 
                 107 
                 535 
                 3.69 
               
               
                 M3D4 
                 76 
                 541 
                 9.13 
                 92 
                 491 
                 6.22 
                 108 
                 524 
                 3.27 
               
               
                 M4D1 
                 77 
                 380 
                 2.34 
                 93 
                 368 
                 2.11 
                 109 
                 416 
                 1.85 
               
               
                 M4D2 
                 78 
                 392 
                 2.86 
                 94 
                 372 
                 3.13 
                 110 
                 413 
                 3.18 
               
               
                 M4D3 
                 79 
                 399 
                 4.59 
                 95 
                 375 
                 2.92 
                 111 
                 418 
                 6.96 
               
               
                 M4D4 
                 80 
                 395 
                 4.57 
                 96 
                 388 
                 2.92 
                 112 
                 441 
                 6.46 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 19 
               
             
            
               
                   
                   
               
               
                   
                 N326/55 phr/0 
               
            
           
           
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1200 
                   
                   
                 1060 
                   
               
               
                 M2 
                   
                 1030 
                   
                   
                 934 
               
               
                 M3 
                   
                 724 
                   
                   
                 777 
               
               
                 M4 
                   
                 635 
                   
                   
                 644 
               
               
                 M1D1 
                 145 
                 550 
                 3.49 
                 161 
                 644 
                 1.15 
               
               
                 M1D2 
                 146 
                 636 
                 3.54 
                 162 
                 661 
                 1.32 
               
               
                 M1D3 
                 147 
                 650 
                 5.89 
                 163 
                 697 
                 1.35 
               
               
                 M1D4 
                 148 
                 724 
                 4.79 
                 164 
                 732 
                 2.01 
               
               
                 M2D1 
                 149 
                 517 
                 3.16 
                 165 
                 590 
                 1.50 
               
               
                 M2D2 
                 150 
                 572 
                 2.41 
                 166 
                 621 
                 1.56 
               
               
                 M2D3 
                 151 
                 613 
                 3.11 
                 167 
                 641 
                 2.22 
               
               
                 M2D4 
                 152 
                 696 
                 4.37 
                 168 
                 676 
                 2.31 
               
               
                 M3D1 
                 153 
                 489 
                 2.78 
                 169 
                 551 
                 1.22 
               
               
                 M3D2 
                 154 
                 521 
                 1.93 
                 170 
                 550 
                 1.62 
               
               
                 M3D3 
                 155 
                 504 
                 3.14 
                 171 
                 563 
                 2.06 
               
               
                 M3D4 
                 156 
                 538 
                 2.81 
                 172 
                 578 
                 2.68 
               
               
                 M4D1 
                 157 
                 415 
                 1.74 
                 173 
                 487 
                 1.96 
               
               
                 M4D2 
                 158 
                 447 
                 2.17 
                 174 
                 495 
                 2.22 
               
               
                 M4D3 
                 159 
                 466 
                 3.13 
                 175 
                 505 
                 2.99 
               
               
                 M4D4 
                 160 
                 469 
                 2.93 
                 176 
                 526 
                 3.37 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 20 
               
             
            
               
                   
                   
               
               
                   
                 N110/55 phr/0 
               
            
           
           
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
               
                 M1 
                   
                 937 
                   
                   
                 730 
                   
               
               
                 M2 
                   
                 764 
                   
                   
                 653 
               
               
                 M3 
                   
                 569 
                   
                   
                 541 
               
               
                 M4 
                   
                 449 
                   
                   
                 463 
               
               
                 M1D1 
                 369 
                 360 
                 1.24 
                 385 
                 334 
                 1.28 
               
               
                 M1D2 
                 370 
                 426 
                 2.50 
                 386 
                 339 
                 1.60 
               
               
                 M1D3 
                 371 
                 490 
                 2.69 
                 387 
                 372 
                 1.42 
               
               
                 M1D4 
                 372 
                 618 
                 4.68 
                 388 
                 413 
                 2.80 
               
               
                 M2D1 
                 373 
                 340 
                 0.69 
                 389 
                 309 
                 0.72 
               
               
                 M2D2 
                 374 
                 356 
                 0.85 
                 390 
                 314 
                 1.17 
               
               
                 M2D3 
                 375 
                 395 
                 0.90 
                 391 
                 342 
                 1.27 
               
               
                 M2D4 
                 376 
                 433 
                 1.17 
                 392 
                 380 
                 2.94 
               
               
                 M3D1 
                 377 
                 295 
                 0.81 
                 393 
                 271 
                 0.94 
               
               
                 M3D2 
                 378 
                 313 
                 1.27 
                 394 
                 292 
                 0.93 
               
               
                 M3D3 
                 379 
                 333 
                 1.20 
                 395 
                 314 
                 1.43 
               
               
                 M3D4 
                 380 
                 353 
                 1.35 
                 396 
                 351 
                 1.77 
               
               
                 M4D1 
                 381 
                 255 
                 1.12 
                 397 
                 260 
                 0.74 
               
               
                 M4D2 
                 382 
                 269 
                 1.14 
                 398 
                 267 
                 0.93 
               
               
                 M4D3 
                 383 
                 287 
                 1.30 
                 399 
                 284 
                 1.49 
               
               
                 M4D4 
                 384 
                 316 
                 1.67 
                 400 
                 297 
                 1.83 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 21(B) 
               
             
            
               
                   
                   
               
               
                   
                 S6740/55 phr/0 
               
               
                   
                 SMRCV 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Sample 
                 Mw sol   
                   
               
               
                   
                 Code 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
                   
               
               
                   
                 M1 
                   
                 876 
                   
               
               
                   
                 M2 
                   
                 754 
               
               
                   
                 M3 
                   
                 574 
               
               
                   
                 M4 
                   
                 444 
               
               
                   
                 M1D1 
                 428 
                 433 
                 0.25 
               
               
                   
                 M1D2 
                 429 
                 441 
                 0.36 
               
               
                   
                 M1D3 
                 430 
                 467 
                 0.34 
               
               
                   
                 M1D4 
                 431 
                 540 
                 0.84 
               
               
                   
                 M2D1 
                 432 
                 399 
                 0.35 
               
               
                   
                 M2D2 
                 433 
                 399 
                 0.41 
               
               
                   
                 M2D3 
                 434 
                 422 
                 0.62 
               
               
                   
                 M2D4 
                 435 
                 469 
                 0.44 
               
               
                   
                 M3D1 
                 436 
                 340 
                 0.44 
               
               
                   
                 M3D2 
                 437 
                 363 
                 0.81 
               
               
                   
                 M3D3 
                 438 
                 377 
                 0.89 
               
               
                   
                 M3D4 
                 439 
                 403 
                 0.86 
               
               
                   
                 M4D1 
                 440 
                 363 
                 0.65 
               
               
                   
                 M4D2 
                 441 
                 328 
                 1.05 
               
               
                   
                 M4D3 
                 442 
                 342 
                 1.52 
               
               
                   
                 M4D4 
                 443 
                 360 
                 1.99 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 21(A) 
               
             
            
               
                   
                   
               
               
                   
                 S6740/55 phr/0 
               
               
                   
                 RSS1 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Sample 
                 Mw sol   
                   
               
               
                   
                 Code 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 M1 
                   
                 1080 
                   
               
               
                   
                 M2 
                   
                 837 
               
               
                   
                 M3 
                   
                 724 
               
               
                   
                 M4 
                   
                 532 
               
               
                   
                 M1D1 
                 412 
                 515 
                 1.24 
               
               
                   
                 M1D2 
                 413 
                 556 
                 1.32 
               
               
                   
                 M1D3 
                 414 
                 633 
                 1.41 
               
               
                   
                 M1D4 
                 415 
                 732 
                 1.43 
               
               
                   
                 M2D1 
                 416 
                 433 
                 0.86 
               
               
                   
                 M2D2 
                 417 
                 451 
                 0.90 
               
               
                   
                 M2D3 
                 418 
                 495 
                 1.53 
               
               
                   
                 M2D4 
                 419 
                 542 
                 2.15 
               
               
                   
                 M3D1 
                 420 
                 405 
                 0.25 
               
               
                   
                 M3D2 
                 421 
                 418 
                 0.50 
               
               
                   
                 M3D3 
                 422 
                 447 
                 0.75 
               
               
                   
                 M3D4 
                 423 
                 469 
                 0.73 
               
               
                   
                 M4D1 
                 424 
                 371 
                 0.21 
               
               
                   
                 M4D2 
                 425 
                 387 
                 0.42 
               
               
                   
                 M4D3 
                 426 
                 382 
                 0.30 
               
               
                   
                 M4D4 
                 427 
                 396 
                 0.56 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 22(A) 
               
             
            
               
                   
                   
               
               
                   
                 Regal 660/55 phr/0 
               
            
           
           
               
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
                 SMR10 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1110 
                   
                   
                 836 
                   
                   
                 746 
                   
               
               
                 M2 
                   
                 844 
                   
                   
                 709 
                   
                   
                 632 
               
               
                 M3 
                   
                 609 
                   
                   
                 584 
                   
                   
                 492 
               
               
                 M4 
                   
                 522 
                   
                   
                 513 
                   
                   
                 416 
               
               
                 M1D1 
                 177 
                 674 
                 8.35 
                 193 
                 564 
                 1.87 
                 209 
                 501 
                 9.54 
               
               
                 M1D2 
                 178 
                 792 
                 7.89 
                 194 
                 611 
                 2.50 
                 210 
                 572 
                 6.68 
               
               
                 M1D3 
                 179 
                 891 
                 8.53 
                 195 
                 708 
                 3.08 
                 211 
                 681 
                 7.37 
               
               
                 M1D4 
                 180 
                 676 
                 7.46 
                 196 
                 671 
                 2.31 
                 212 
                 594 
                 7.18 
               
               
                 M2D1 
                 181 
                 598 
                 8.56 
                 197 
                 520 
                 5.28 
                 213 
                 463 
                 2.82 
               
               
                 M2D2 
                 182 
                 602 
                 3.89 
                 198 
                 558 
                 4.85 
                 214 
                 483 
                 4.57 
               
               
                 M2D3 
                 183 
                 697 
                 6.40 
                 199 
                 603 
                 2.88 
                 215 
                 565 
                 3.92 
               
               
                 M2D4 
                 184 
                 659 
                 5.71 
                 200 
                 541 
                 4.25 
                 216 
                 550 
                 5.68 
               
               
                 M3D1 
                 185 
                 473 
                 2.03 
                 201 
                 486 
                 2.79 
                 217 
                 395 
                 2.13 
               
               
                 M3D2 
                 186 
                 506 
                 1.66 
                 202 
                 482 
                 2.76 
                 218 
                 393 
                 1.98 
               
               
                 M3D3 
                 187 
                 562 
                 1.94 
                 203 
                 504 
                 3.54 
                 219 
                 443 
                 2.49 
               
               
                 M3D4 
                 188 
                 559 
                 4.33 
                 204 
                 526 
                 2.41 
                 220 
                 449 
                 1.90 
               
               
                 M4D1 
                 189 
                 401 
                 2.18 
                 205 
                 415 
                 3.16 
                 221 
                 335 
                 1.49 
               
               
                 M4D2 
                 190 
                 426 
                 1.72 
                 206 
                 418 
                 2.92 
                 222 
                 345 
                 1.71 
               
               
                 M4D3 
                 191 
                 466 
                 1.48 
                 207 
                 446 
                 2.80 
                 223 
                 363 
                 1.78 
               
               
                 M4D4 
                 192 
                 449 
                 3.57 
                 208 
                 465 
                 3.13 
                 224 
                 374 
                 2.35 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 22(B) 
               
             
            
               
                   
                   
               
               
                   
                 Regal 660/45/0 
                 Regal 660/65/0 
                 Regal 660/65/10 
               
               
                   
                 RSS1 
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1245 
                   
                   
                 1245 
                   
                   
                 1245 
                   
               
               
                 M2 
                   
                 876 
                   
                   
                 876 
                   
                   
                 876 
               
               
                 M3 
                   
                 625 
                   
                   
                 625 
                   
                   
                 625 
               
               
                 M4 
                   
                 482 
                   
                   
                 482 
                   
                   
                 482 
               
               
                 M1D1 
                 225 
                 646 
                 3.45 
                 241 
                 563 
                 14.55 
                 257 
                 639 
                 1.63 
               
               
                 M1D2 
                 226 
                 697 
                 3.04 
                 242 
                 638 
                 14.09 
                 258 
                 699 
                 3.55 
               
               
                 M1D3 
                 227 
                 762 
                 7.70 
                 243 
                 691 
                 13.64 
                 259 
                 814 
                 5.44 
               
               
                 M1D4 
                 228 
                 830 
                 6.75 
                 244 
                 790 
                 11.26 
                 260 
                 764 
                 11.25 
               
               
                 M2D1 
                 229 
                 574 
                 4.79 
                 245 
                 469 
                 5.88 
                 261 
                 572 
                 2.77 
               
               
                 M2D2 
                 230 
                 589 
                 3.02 
                 246 
                 507 
                 7.31 
                 262 
                 580 
                 4.39 
               
               
                 M2D3 
                 231 
                 636 
                 6.41 
                 247 
                 558 
                 9.72 
                 263 
                 610 
                 5.51 
               
               
                 M2D4 
                 232 
                 675 
                 6.55 
                 248 
                 543 
                 10.59 
                 264 
                 638 
                 7.29 
               
               
                 M3D1 
                 233 
                 471 
                 2.66 
                 249 
                 420 
                 5.48 
                 265 
                 474 
                 4.10 
               
               
                 M3D2 
                 234 
                 481 
                 5.17 
                 250 
                 426 
                 6.97 
                 266 
                 485 
                 5.72 
               
               
                 M3D3 
                 235 
                 510 
                 7.78 
                 251 
                 468 
                 8.81 
                 267 
                 502 
                 6.24 
               
               
                 M3D4 
                 236 
                 518 
                 7.89 
                 252 
                 471 
                 9.55 
                 268 
                 495 
                 7.13 
               
               
                 M4D1 
                 237 
                 388 
                 3.20 
                 253 
                 335 
                 5.19 
                 269 
                 390 
                 5.02 
               
               
                 M4D2 
                 238 
                 392 
                 5.65 
                 254 
                 344 
                 6.06 
                 270 
                 365 
                 5.88 
               
               
                 M4D3 
                 239 
                 397 
                 5.14 
                 255 
                 344 
                 5.59 
                 271 
                 410 
                 7.45 
               
               
                 M4D4 
                 240 
                 403 
                 7.54 
                 256 
                 361 
                 8.54 
                 272 
                 388 
                 7.59 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 23(A) 
               
             
            
               
                   
                   
               
               
                   
                 N234/55 phr/0 
               
            
           
           
               
               
               
               
            
               
                   
                 RSS1 
                 SMRCV 
                 SMR10 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1060 
                   
                   
                 845 
                   
                   
                 743 
                   
               
               
                 M2 
                   
                 811 
                   
                   
                 712 
                   
                   
                 621 
               
               
                 M3 
                   
                 595 
                   
                   
                 577 
                   
                   
                 445 
               
               
                 M4 
                   
                 466 
                   
                   
                 477 
                   
                   
                 388 
               
               
                 M1D1 
                 273 
                 350 
                 1.88 
                 289 
                 312 
                 0.61 
                 305 
                 325 
                 0.78 
               
               
                 M1D2 
                 274 
                 476 
                 3.40 
                 290 
                 317 
                 0.64 
                 306 
                 363 
                 1.66 
               
               
                 M1D3 
                 275 
                 459 
                 2.70 
                 291 
                 361 
                 1.03 
                 307 
                 400 
                 1.89 
               
               
                 M1D4 
                 276 
                 665 
                 2.70 
                 292 
                 419 
                 1.56 
                 308 
                 459 
                 1.73 
               
               
                 M2D1 
                 277 
                 323 
                 0.40 
                 293 
                 304 
                 0.76 
                 309 
                 294 
                 0.54 
               
               
                 M2D2 
                 278 
                 371 
                 0.73 
                 294 
                 306 
                 0.72 
                 310 
                 321 
                 1.24 
               
               
                 M2D3 
                 279 
                 398 
                 0.74 
                 295 
                 318 
                 0.74 
                 311 
                 354 
                 1.28 
               
               
                 M2D4 
                 280 
                 464 
                 1.42 
                 296 
                 357 
                 1.30 
                 312 
                 363 
                 1.39 
               
               
                 M3D1 
                 281 
                 278 
                 0.47 
                 297 
                 260 
                 0.53 
                 313 
                 260 
                 0.69 
               
               
                 M3D2 
                 282 
                 304 
                 0.83 
                 298 
                 272 
                 0.65 
                 314 
                 268 
                 0.48 
               
               
                 M3D3 
                 283 
                 323 
                 0.82 
                 299 
                 295 
                 0.58 
                 315 
                 289 
                 1.38 
               
               
                 M3D4 
                 284 
                 360 
                 1.06 
                 300 
                 302 
                 1.14 
                 315 
                 303 
                 0.78 
               
               
                 M4D1 
                 285 
                 251 
                 0.61 
                 301 
                 244 
                 0.53 
                 317 
                 236 
                 1.00 
               
               
                 M4D2 
                 286 
                 266 
                 0.51 
                 302 
                 253 
                 0.81 
                 318 
                 239 
                 0.77 
               
               
                 M4D3 
                 287 
                 273 
                 0.64 
                 303 
                 266 
                 0.62 
                 319 
                 257 
                 0.72 
               
               
                 M4D4 
                 288 
                 282 
                 0.53 
                 304 
                 296 
                 0.88 
                 320 
                 268 
                 1.30 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 23(B) 
               
             
            
               
                   
                   
               
               
                   
                 N234/45/0 
                 N234/65/0 
                 N234/65/10 
               
               
                   
                 RSS1 
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 M1 
                   
                 1185 
                   
                   
                 1185 
                   
                   
                 1185 
                   
               
               
                 M2 
                   
                 828 
                   
                   
                 828 
                   
                   
                 828 
               
               
                 M3 
                   
                 623 
                   
                   
                 623 
                   
                   
                 623 
               
               
                 M4 
                   
                 462 
                   
                   
                 462 
                   
                   
                 462 
               
               
                 M1D1 
                 321 
                 507 
                 7.33 
                 337 
                 336 
                 3.44 
                 353 
                 395 
                 5.51 
               
               
                 M1D2 
                 322 
                 598 
                 8.15 
                 338 
                 458 
                 5.09 
                 354 
                 478 
                 7.68 
               
               
                 M1D3 
                 323 
                 731 
                 8.97 
                 339 
                 479 
                 8.17 
                 355 
                 555 
                 9.46 
               
               
                 M1D4 
                 324 
                 772 
                 12.02 
                 340 
                 706 
                 9.90 
                 356 
                 637 
                 8.39 
               
               
                 M2D1 
                 325 
                 486 
                 3.48 
                 341 
                 255 
                 3.22 
                 357 
                 295 
                 0.58 
               
               
                 M2D2 
                 326 
                 479 
                 5.44 
                 342 
                 288 
                 3.34 
                 358 
                 352 
                 1.23 
               
               
                 M2D3 
                 327 
                 527 
                 5.51 
                 343 
                 295 
                 4.65 
                 359 
                 394 
                 1.35 
               
               
                 M2D4 
                 328 
                 566 
                 7.70 
                 344 
                 393 
                 5.45 
                 360 
                 449 
                 2.37 
               
               
                 M3D1 
                 329 
                 419 
                 0.88 
                 345 
                 237 
                 1.50 
                 361 
                 292 
                 0.86 
               
               
                 M3D2 
                 330 
                 423 
                 1.24 
                 346 
                 252 
                 1.78 
                 362 
                 286 
                 1.14 
               
               
                 M3D3 
                 331 
                 431 
                 2.55 
                 347 
                 270 
                 2.88 
                 363 
                 313 
                 2.19 
               
               
                 M3D4 
                 332 
                 458 
                 4.03 
                 348 
                 304 
                 3.92 
                 364 
                 340 
                 2.51 
               
               
                 M4D1 
                 333 
                 341 
                 0.62 
                 349 
                 226 
                 1.18 
                 365 
                 265 
                 0.83 
               
               
                 M4D2 
                 334 
                 338 
                 1.13 
                 350 
                 214 
                 1.81 
                 366 
                 273 
                 0.99 
               
               
                 M4D3 
                 335 
                 319 
                 1.37 
                 351 
                 233 
                 2.97 
                 367 
                 291 
                 1.39 
               
               
                 M4D4 
                 336 
                 354 
                 2.06 
                 352 
                 258 
                 3.83 
                 368 
                 307 
                 2.41 
               
               
                   
               
            
           
         
       
     
     Preferred Embodiment Examples 
     Additional samples of elastomer composites in accordance with the present invention were prepared. Specifically, a series of natural rubber elastomer composites no. 1-32 in accordance with the present invention was produced using apparatus and procedures generally in accordance with those of Example A above. The elastomer composites comprised natural rubber field latex from Malaysia with the properties shown in Table 24 below. The elastomer composites each further comprised carbon black with morphological properties (structure and surface area) of Regions I, II or III in  FIG. 8 . Specifically, the following carbon blacks were used: Regal® 660, N234, N326, N110, Regal® 250, N330, Black Pearl® 800, Sterling® 6740 and N351. The carbon black loadings ranged from 30 to 75 phr, and extender oil loadings were in an amount from 0 to 20 phr. The production details for elastomer composite sample nos. 1-32 are shown below in Table 25. 
     As noted above, the apparatus and procedures used to prepare elastomer composites no. 1-32 were generally in accordance with those of Example A, including the masterbatch formulation additives shown in Table 2. A more detailed description of the apparatus and procedures used for elastomer composites no. 1-32 is set forth below. 
     1. Apparatus 
     Invention samples no. 1-32 were prepared using masterbatch production apparatus substantially in accordance with the invention apparatus described above with reference to  FIGS. 1 ,  4  and  7 . The diameter of the slurry nozzle tip (see item  167  in  FIG. 7 ) and the length of the land (see item  168  in  FIG. 7 ) are given in Table 25 for each of samples no. 1-32. The coagulum zone of the apparatus had four zones of progressively larger diameter from the mixing zone to the discharge end. The diameter and axial length of each of the four zones (the first zone being partly within the mix-head and partly within the extender sealed thereto) are set forth in Table 25. There were axially short, faired interconnections between the zones. 
     2. Carbon Black Slurry Preparation 
     Bags of carbon black were mixed with deionized water in a carbon black slurry tank equipped with an agitator. The agitator broke the pellets into fragments to form a crude carbon black slurry. The carbon black concentration (as weight percent) in the carbon black slurry for each of the sample is given in Table 25. During operation, this slurry was continually pumped by an air diaphragm pump to a grinder for initial dispersion. The slurry was then fed via an air diaphragm pump to a colloid mill which then fed into a progressing cavity pump to a homogenizer, specifically, Microfluidizer Model M210 from Microfluidics International Corporation. The microfluidizer produced a finely ground slurry. The slurry flow rate from the microfluidizer to the mixing zone was set by the microfluidizer pressure, the microfluidizer acting as a high-pressure positive displacement pump. Slurry flow rate was monitored with a Micromotion® mass flow meter. The pressure at which the carbon black slurry was fed to the homogenizer and the homogenizer output pressure (all pressures are psig) are set forth for each sample in Table 25. From the homogenizer the carbon black slurry was fed to an accumulator to reduce any fluctuation in slurry pressure at the slurry nozzle tip in the mixing zone. The slurry nozzle tip pressure and flow rate at which the slurry was fed to the mixing zone for each sample are given in Table 25. 
     3. Latex Delivery 
     The latex was charged to a 55 gallon feed drum. Antioxidant emulsion was then added to the latex and mixed in prior to charging. Antioxidants were added consisting of tris nonyl phenyl phosphite (TNPP) and Santoflex® 134 (alkylaryl p-phenylene diamine mixture) in the amounts shown in Table 25. Each of the antioxidants was prepared as a 40 wt. % emulsion using 4 parts potassium oleate per 100 parts antioxidant along with potassium hydroxide to adjust the emulsion to a pH of approximately 10. Extender oil, if any, was added in the amount shown in Table 25. A peristaltic pump was used to move the latex from the feed drum to the mixing zone of the coagulum reactor. The latex flow rate and velocity are shown in Table 25. Latex flow was automatically metered with a Endress+Hauser mass flow meter. The desired carbon black loading was obtained by maintaining proper ratio of the latex feed rate to the carbon black slurry feed rate. 
     4. Carbon Black and Latex Mixing 
     The carbon black slurry and latex were mixed by entraining the latex into the carbon black slurry. During entrainment, the carbon black was intimately mixed into the latex and the mixture coagulated. Soft, wet spongy “worms” of coagulum exited the coagulum reactor. 
     5. Dewatering 
     The water content of the wet crumb discharged from the coagulum reactor is shown in Table 25. The wet crumb was dewatered with a dewatering extruder (The French Oil Mill Machinery Company; 3½ in. diameter). In the extruder, the wet crumb was compressed and water squeezed form the crumb and through a slotted barrel of the extruder. The final crumb moisture content is shown in Table 25 for each of the invention samples. 
     5. Drying and Cooling 
     The dewatered crumb dropped into a second extruder where it was again compressed and heated. Water was flashed off upon expulsion of the crumb through the die plate of the extruder. Product exit temperature and moisture content are shown in Table 25. The hot, dry crumb was rapidly cooled (approximately 20 seconds) to about 100° F. by a forced air vibrating conveyor. 
     
       
         
           
               
             
               
                 TABLE 24 
               
             
            
               
                   
               
               
                 Natural Rubber Latex Properties 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 Volatile 
               
               
                   
                   
                   
                 % Dry 
                 % Total 
                   
                 Nitrogen 
                 Fatty 
               
               
                 Latex Type 
                 Source 
                 Additives 
                 Rubber 
                 Solids 
                 % Ash 
                 ppm 
                 Acid 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Concentrate 
                 TITI Latex 
                 0.35% NH 3   
                 60 
                 62.0 
                 0.15 
                 0.29 
                 0.022 
               
               
                   
                 SDN. BHD. 
                 ZnO, TMTD 
               
               
                   
                   
                 0.1% HHS 
               
               
                 Field Latex 
                 RRIM a , 
                 0.15% HNS c   
                 28.4 
                 34.2 
                 0.38 
                 0.366 
                 0.052 
               
               
                   
                 September 1994 
                 0.3% NH3, 
               
               
                   
                   
                 ZnO, TMTD b   
               
               
                   
               
               
                   a RRIM is the Rubber Research Institute of Malaysia 
               
               
                   b ZnO/TMTD: used for biological preservation, typical 0.025% of 1:1 mixture 
               
               
                   c HNS: hydroxylamine neutral sulfate, Mooney viscosity stabilizer 
               
            
           
         
       
     
                     TABLE 25               Invention Sample Production Details                                                    Cabot Elastomer Composite   Slurry Nozzle Tip   MicroFluidizer                                             Invention       Carbon Black   Oil loading   Dia.   Land length   Inlet pressure   Outlet pressure                                                 Sample No.   Latex type   Type   Loading (phr)   (phr)   (in)   (in)   (psi)   (psi)                1   field latex   N330   55   0   0.025   0.5   190   3000        2   field latex   N330   55   0   0.039   1   300   0        3   field latex   N330   55   0   0.039   1   300   0        4   field latex   REGAL 250   55   0   0.025   0.5   180   3500        5   field latex   REGAL 250   65   0   0.025   0.5   300   10000        6   field latex   REGAL 250   75   0   0.025   0.5   200   13000        7   field latex   REGAL 250   65   10   0.025   0.5   250   12000        8   field latex   BLACK PEARL   55   0   0.025   0.5   200   4000               800        9   field latex   N326   55   0   0.025   1   250   3000       10   field latex   REGAL 660   55   0   0.025   1   —   —       11   field latex   REGAL 660   45   0   0.025   0.5   200   12500       12   field latex   REGAL 660   65   0   0.025   0.5   260   15000       13   field latex   REGAL 660   65   10   0.025   0.5   200   12000       14   field latex   N234   55   0   0.025   1   180   5500       15   field latex   N234   55   0   0.025   0.5   —   14500       16   field latex   N234   55   0   0.025   0.5   —   14500       17   field latex   N234   55   0   0.025   0.5   —   14500       18   field latex   N234   45   0   0.025   0.5   200   13000       19   field latex   N234   65   0   0.025   0.5   220   13000       20   field latex   N234   65   10   0.025   0.5   300   14500       21   field latex   N110   55   0   0.025   1   120   4500       22   latex concentrate   N351   33   20   0.025   0.5   250   12500       23   field latex   STERLING 6740   55   0   0.025   0.5   250   12000       24   field latex   N234   48   5   0.023   0.5   250   11000       25   field latex   N234   53   5   0.023   0.5   250   11000       26   field latex   N234   58   5   0.023   0.5   250   11000       27   field latex   N234   63   5   0.023   0.5   250   11000       28   field latex   N234   68   5   0.023   0.5   250   11000       29   latex concentrate   N234   49   5   0.023   0.5   —   —       30   latex concentrate   N234   54   5   0.023   0.5   —   11000       31   latex concentrate   N234   63   5   0.023   0.5   —   11000       32   latex concentrate   N234   65   5   0.023   0.5   —   11000                                     Coagulum Zone   CB Slurry                                     Invention   1st portion   2nd portion   3rd portion   4th portion   CB conc.                                                     Sample No.   Dia. (in)   Length (in)   Dia. (in)   Length (in)   Dia. (in)   Length (in)   Dia. (in)   Length (in)   (% wt)                1   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.2        2   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   14.9        3   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   14.9        4   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   19.0        5   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   21.0        6   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   21.0        7   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   21.0        8   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.0        9   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   14.8       10   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   14.9       11   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.2       12   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.2       13   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.2       14   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   14.8       15   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.7       16   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.7       17   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.7       18   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   14.6       19   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   14.6       20   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   14.6       21   0.19   1.1   0.27   1.6   0.38   2.3   0.53   3.2   11.8       22   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   15.0       23   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   14.7       24   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.5       25   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.5       26   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.5       27   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.5       28   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   13.5       29   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   12.8       30   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   12.8       31   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   12.8       32   0.19   3.0   0.27   1.6   0.38   2.3   0.53   3.2   12.8                                     Slurry Nozzle   Mixing Zone                                         Invention   Tip Pressure   Slurry flow rate   Slurry velocity   Antioxidant   Latex flow rate   Latex velocity                                             Sample No.   (psi)   (lb/min)   (ft/sec)   TNPP (phr)   Santoflex (phr)   (lbs/min)   (ft/sec)                1   1400   4.6   336   0.3   0.4   4.7   6.8        2   425   8.2   247   0.3   0.4   8.9   13.2        3   425   8.2   247   0.3   0.4   8.9   13.2        4   1500   4.8   344   0.3   0.4   6.7   9.7        5   1500   5.2   370   0.3   0.4   6.8   9.8        6   1575   5.2   370   0.3   0.4   5.9   8.5        7   1550   5.2   370   0.3   0.4   6.9   10.0        8   1800   5.2   380   0.3   0.4   4.9   7.1        9   600   4.2   308   0.3   0.4   4.0   5.8       10   —   4.0   293   0.3   0.4   3.6   5.2       11   1500   5.1   373   0.3   0.4   7.0   10.1       12   1300   4.8   351   0.3   0.4   4.6   6.7       13   1375   4.9   358   0.3   0.4   4.8   6.9       14   900   5.3   388   0.3   0.4   4.8   6.9       15   1400   5.7   420   0.3   0.4   5.4   7.8       16   1400   5.7   420   0.3   0.4   5.4   7.8       17   1400   5.7   420   0.3   0.4   5.4   7.8       18   1600   5.2   381   0.3   0.4   6.5   9.4       19   1650   5.3   388   0.3   0.4   4.5   6.5       20   1625   5.3   388   0.3   0.4   4.6   6.7       21   900   5.3   394   0.3   0.4   4.1   5.9       22   1550   5.1   373   0.3   0.4   5.1   7.6       23   1550   5.2   381   0.3   0.4   5.7   8.3       24   2270   5.1   444   0.3   0.4   6.1   8.8       25   2250   5.1   444   0.3   0.4   5.5   7.9       26   2270   5.1   444   0.3   0.4   5.0   7.2       27   2260   5.1   444   0.3   0.4   4.6   6.6       28   —   5.1   444   0.3   0.4   4.2   6.1       29   2350   5.3   463   0.3   0.4   2.6   3.8       30   2360   5.3   463   0.3   0.4   2.3   3.4       31   2350   5.3   463   0.3   0.4   2.1   3.1       32   2420   5.3   463   0.3   0.4   2.0   3.0                                             Dewatering       Drying and Cooling                                     Invention   Initial crumb moisture   Final crumb moisture   Product temperature   Product moisture       Sample No.   (%)   (%)   (° F.)   (%)                1   77.6   6.5   312   0.3        2   78.7   —   450   0.2        3   78.7   7.8   400   0.2        4   74.9   —   350   0.3        5   76.2   7.9   310   0.2        6   76.4   11.4    —   0.2        7   75.6   8.8   335   0.3        8   77.7   6.5   310   0.2        9   77.9   8.9   345   0.2       10   77.8   —   —   0.4       11   78.7   9.7   285   0.5       12   79.7   —   335   0.2       13   79.1   —   —   0.9       14   77.9   8.4   330   0.1       15   79.2   —   oven dried   —       16   79.2   10.3    oven dried   —       17   79.2   11.2    oven dried   —       18   79.0   15.0    370   0.4       19   80.0   3.6   325   0.3       20   79.5   9.4   345   0.5       21   80.5   9.5   350   0.2       22   65.1   9.1   280   0.3       23   78.1   6     330   0.8       24   77.4   —   380   0.3       25   77.8   —   390   0.4       26   78.1   —   400   0.7       27   78.4   —   410   0.4       28   78.7   —   420   1.1       29   71.2   —   400   0.6       30   72.3   —   420   0.4       31   73.3   —   400-450   0.9       32   74.1   —   400-450   0.2                    
It should be noted that samples 2 and 3 were produced with approximately no outlet pressure at the Microfluidizer outlet, etc., to determine macro-dispersion under adverse process conditions.
 
     The excellent carbon black dispersion in the resultant masterbatches is demonstrated by their macro-dispersion quality and molecular weight of the sol portion MW sol . Table 26 below shows the MW sol  and macro-dispersion values for invention samples 1-32, along with the carbon black and oil (if any) used in each of the samples. The carbon black loading and oil loading are shown as phr values in Table 26. 
                     TABLE 26                  Sol Molecular Weight and Undispersed Area of Invention Samples                             Invention Sample No.   CB/Loading/Oil   Mw sol  (K)   D (%)                                     1   N330/55/0   305   0.26       2   N330/55/0   726   0.54       3   N330/55/0   544   0.40       4   R250/55/0   876   0.08       5   R250/65/0   670   0.16       6   R250/75/0   655   0.03       7   R250/65/10   519   0.02       8   BP800/55/0   394   0.14       9   N326/55/0   666   0.20       10   R660/55/0   678   0.12       11   R660/45/0   733   0.05       12   R660/65/0   568   0.04       13   R660/65/10   607   0.02       14   N234/55/0   433   0.15       15   N234/55/0   1000   0.10       16   N234/55/0   500   0.15       17   N234/55/0   550   0.10       18   N234/45/0   495   0.17       19   N234/65/0   359   0.20       20   N234/65/10   350   0.11       21   N110/55/0   612   0.17       22   N351/33/20   800   0.10       23   S6740/55/0   630   0.10       24   N234/48/5   569   0.05       25   N234/53/5   485   0.12       26   N234/58/5   447   0.12       27   N234/63/5   403   0.13       28   N234/68/5   378   0.16       29   N234/49/5   618   0.12       30   N234/54/5   482   0.16       31   N234/63/5   390   0.17       32   N234/65/5   325   0.20                    
The results for all invention samples having carbon black loading of 55 phr are shown in the semi-log slot of  FIG. 9  along with macro-dispersion and MW sol  values for a corresponding series of the above described natural rubber control samples produced by dry mixing techniques. At least one data point for an invention sample comprising 55 phr loading of each carbon black is shown in  FIG. 9 , along with all of the control samples having carbon black loading of 55 phr. (Control samples 401 to 412, also shown in  FIG. 9 , used 33 phr N351 carbon black and 20 parts extender oil.) It can be seen in Table 26 and in  FIG. 9  that the invention samples have excellent macro-dispersion. Specifically, the invention samples have D(%) values generally below 0.2%, even at MW sol  values above 0.85×10 6  whereas the control samples never achieve such excellent macro-dispersion at any MW sol . Thus, the data shown in  FIG. 9  clearly reveals that the macro-dispersion quality of the novel elastomer composites over a wide range of MW sol  values is significantly superior to that achievable using comparable ingredients in prior-known dry mixing methods. The symbols used for the various data points shown in  FIG. 9  and those used in subsequently discussed  FIGS. 10-25  are explained in the legends below.
 
     
       
         
           
               
             
               
                   
               
               
                 Figure Captiopns 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 FIG. 9 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                     control samples 177 to 224 
               
               
                   
                   
                 ▴ control samples 273 to 320 
               
               
                   
                   
                     control samples 145 to 176 
               
               
                   
                   
                 Δ control samples 369 to 400 
               
               
                   
                   
                 ◯ control samples 33 to 64 
               
               
                   
                   
                     control samples 1 to 32 
               
               
                   
                   
                 ● control samples 113 to 144 
               
               
                   
                   
                 ⋄ control samples 412 to 443 
               
               
                   
                   
                 ♦ control samples 401 to 412 
               
               
                   
                   
                 ▪ invention samples 
               
               
                 FIG. 10 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                     control samples 177 to 224 
               
               
                   
                 (Region I) 
                     invention sample 10 
               
               
                   
                   
                     control samples 145 to 176 
               
               
                   
                   
                     invention sample 9 
               
               
                   
                   
                 ◯ control samples 33 to 64 
               
               
                   
                   
                 □ invention sample 4 
               
               
                   
                   
                     control samples 1 to 32 
               
               
                   
                   
                     invention sample 1 
               
               
                   
                   
                 ● control samples 113 to 144 
               
               
                   
                   
                 ▪ invention sample 8 
               
               
                 FIG. 11 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ▴ control samples 273 to 320 
               
               
                   
                 (Region II) 
                 ▪ invention sample 14 
               
               
                   
                   
                 Δ control samples 369 to 400 
               
               
                   
                   
                 □ invention sample 21 
               
               
                 FIG. 12 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ♦ control samples 401 to 412 
               
               
                   
                 (Region III) 
                 ▪ invention sample 22 
               
               
                   
                   
                 ⋄ control samples 412 to 443 
               
               
                   
                   
                 □ invention sample 23 
               
               
                 FIG. 13 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 1 to 32 
               
               
                   
                 (N330 Carbon Black, 55 phr) 
                 ▪ invention samples 1 to 3 
               
               
                 FIG. 14 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 33 to 64 
               
               
                   
                 (REGAL 250 Carbon Black) 
                 ▪ invention sample 4 
               
               
                   
                   
                 ◯ control sample 65 to 80 
               
               
                   
                   
                 □ invention sample 5 
               
               
                   
                   
                 ⋄ control samples 81 to 96 
               
               
                   
                   
                 Δ invention sample 6 
               
               
                   
                   
                 ♦ control samples 97 to 112 
               
               
                   
                   
                 ▴ invention sample 7 
               
               
                 FIG. 15 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 113 to 144 
               
               
                   
                 (BLACK PEARL 800 Carbon Black, 55 phr) 
                 ▪ invention sample 8 
               
               
                 FIG. 16 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 145 to 176 
               
               
                   
                 (N326 Carbon Black, 55 phr) 
                 ▪ invention sample 9 
               
               
                 FIG. 17 
                 Dispersion Quality and MW sol of NR Masterbatches 
                 ● control samples 177 to 224 
               
               
                   
                 (REGAL 660 Carbon Black) 
                 ▪ invention sample 10 
               
               
                   
                   
                 ◯ control samples 225 to 240 
               
               
                   
                   
                 □ invention sample 11 
               
               
                   
                   
                 ⋄ control samples 241 to 256 
               
               
                   
                   
                 Δ invention sample 12 
               
               
                   
                   
                 ♦ control samples 257 to 272 
               
               
                   
                   
                 ▴ invention sample 13 
               
               
                 FIG. 18 
                 Dispersion Quality and MW sol of NR Masterbatches 
                 ● control samples 273 to 320 
               
               
                   
                 (N234 Carbon Black) 
                 ▪ invention samples 14 to 17 
               
               
                   
                   
                 ◯ control samples 337 to 352 
               
               
                   
                   
                 □ invention sample 19 
               
               
                   
                   
                 ⋄ control samples 321 to 336 
               
               
                   
                   
                 Δ invention sample 18 
               
               
                   
                   
                 ♦ control samples 353 to 368 
               
               
                   
                   
                 ▴ invention sample 20 
               
               
                 FIG. 19 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 369 to 400 
               
               
                   
                 (N110 Carbon Black, 55 phr) 
                 ▪ invention sample 21 
               
               
                 FIG. 20 
                 Dispersion Quality and MW sol of NR Masterbatch 
                 ● control samples 401 to 412 
               
               
                   
                 (N351 Carbon Black, 33 phr) 
                 ▪ invention sample 22 
               
               
                 FIG. 21 
                 Dispersion Quality and MW Sol of NR Masterbatches 
                 ● control samples 412 to 443 
               
               
                   
                 (STERLING 6740 Carbon Black, 55 phr) 
                 ▪ invention sample 23 
               
               
                 FIG. 22 
                 MW sol Effect on Crack Growth Rate 
                 ● control samples 273 to 288 
               
               
                   
                 (NR Compounds Containing N234 Carbon Black @ 55 phr Loading) 
                 □ invention sample 16 
               
               
                 FIG. 23 
                 MW sol Effect on Crack Growth Rate 
                 ● control samples 145 to 160 
               
               
                   
                 (NR Compounds Containing N326 Carbon Black @ 55 phr Loading) 
                 ◯ invention sample 9 
               
               
                 FIG. 24 
                 MW sol Effect on Crack Growth Rate 
                 ● control samples 177 to 192 
               
               
                   
                 (NR Compounds Containing REGAL 660 Carbon Black @ 55 phr Loading) 
                 □ invention sample 10 
               
               
                 FIG. 25 
                 Max. Tan δ (Strain Sweep @ 60 C.) of NR Compounds Containing N234 
                 ● invention samples 24 to 28 
               
               
                   
                 Black at Different Loadings 
                 ◯ invention samples 29 to 32 
               
               
                   
                   
                 □ control sample 444 to 450 
               
               
                 FIG. 30 
                 Macro-dispersion Quality and MW of Sol Portion of NR Masterbatch 
                 ● control samples 451 to 458 
               
               
                   
                 Containing Dual Phase (Carbon Black/Silica) Aggregates 
                 ▪ invention sample 33 
               
               
                   
                   
                 ◯ control samples 459 to 466 
               
               
                   
                   
                 □ invention sample 34 
               
               
                 FIG. 31 
                 Macro-dispersion Quality and MW of Sol Portion of NR Masterbatch 
                 ● control samples 491 to 498 
               
               
                   
                 Containing Blend of Carbon Black and Silica 
                 ▪ invention sample 38 
               
               
                   
                   
                 ◯ control samples 483 to 490 
               
               
                   
                   
                 □ invention sample 37 
               
               
                   
                   
                 ◯ control samples 475 to 482 
               
               
                   
                   
                 □ invention sample 36 
               
               
                   
                   
                 ● control samples 467 to 474 
               
               
                   
                   
                 ▪ invention sample 35 
               
               
                   
               
            
           
         
       
     
     The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 9  are described by the following equations:
 
 D (%)&lt;0.2%  (1)
 
when MW sol  is less than 0.45×10 6 ; and
 
log( D )&lt;log(0.2)+2.0×[MW sol −(0.45×10 6 )]× 10   −6   (2)
 
when 0.45×10 6 &lt;MW sol &lt;1.1×10 6 .
 
It will be recognized from the discussion above, that macro-dispersion D (%) in the above equation (1) is the percent undispersed area measured for defects greater than 10 microns. It can be seen in  FIG. 9  that D(%) equal to 0.2% is the threshold macro-dispersion quality for all carbon blacks in Regions I, II and III for natural rubber dry masterbatches. That is, none of the dry masticated masterbatches achieved macro-dispersion quality of 0.2% at any MW sol , even after mixing sufficiently to degrade MW sol  below 0.45×10 6 , as described by equation (1) above. When the MW sol  of the dry masterbatch control samples shown in  FIG. 9  is between 0.45× 10   6  and 1.1×10 6 , the dispersion quality is even poorer while, in contrast, the dispersion quality of the invention samples having MW sol  in that range remains excellent. None of the preferred embodiments shown in  FIG. 9  having MW sol  between 0.45×10 6  and 1.1×10 6  exceeds the preferred macro-dispersion limit of 0.2%. In that regard, it should be understood that the data points for preferred embodiments which are seen in  FIG. 9  (and in other Figures discussed below) to lie on the X axis (i.e., at D(%) value of 0.1%) may have macro-dispersion quality of 0.1% or an even better (i.e., lower) D(%) value.
 
Region I Carbon Black Samples
 
     Invention samples comprising carbon blacks having morphological properties (i.e., structures and surface area) of Region I in  FIG. 8 , and corresponding control samples described above made with such Region I carbon blacks, are compared in the semi-log plot of  FIG. 10 . Specifically,  FIG. 10  shows the macro-dispersion values and MW sol  values of the invention samples and corresponding control samples comprising the carbon blacks Regal® 660, N326, Regal® 250, N330, and Black Pearl® 800, at carbon black loading ranging from 30 phr to 75 phr and extender oil loading ranging from 0 phr to 20 phr. Excellent carbon black dispersion is seen in  FIG. 10  for all of the invention samples, representing preferred embodiments of elastomer composites in accordance with the present disclosure. All of the invention samples advantageously are below line  101  in  FIG. 10 , whereas all of the control samples have poorer dispersion, being above line  101 . In fact, the preferred embodiments shown in  FIG. 10 , even through comprising carbon blacks from Region I, the most difficult to disperse, all fall below a D(%) value of 0.3%. The most preferred embodiments all have a D(%) value not exceeding 0.2% even at an MW sol  value advantageously exceeding 0.7×10 6 . The data shown in  FIG. 10  clearly reveals that the macro-dispersion quality of the novel elastomer composites disclosed here comprising Region I carbon blacks, over a wide range of MW sol  values, is significantly superior to that achievable using comparable ingredients by prior dry mastication mixing methods. The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 10  are described by the following equations:
 
 D (%)&lt;1.0%  (3)
 
when MW sol  is less than 0.7×10 6 ; and
 
log  D &lt;log(1.0)+2.5×[MW sol (0.7×10 6 )]×10 −6   (4)
 
when 0.7×10 6 &lt;MW sol &lt;1.1×10 6  
 
It will be recognized that D (%) is the percent undispersed area measured for defects greater than 10 microns and 1% is the threshold macro-dispersion quality for all carbon blacks in Region I for natural rubber masterbatches in accordance with the present invention. That is, none of the dry masticated masterbatches achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.7×10 6 , as described by Equation (3) above. When the MW sol  of the dry masterbatch control samples shown in  FIG. 10  is between 0.7×10 6  and 1.1×10 6 , the dispersion quality is even poorer. In contrast, the dispersion quality of the invention samples having MW sol  in that range remains excellent. The preferred embodiment shown in  FIG. 10  having MW sol  between 0.7×10 6  and 1.1×10 6  falls well below the preferred macro-dispersion limit of 0.2%. It can be seen that the elastomer composites of the invention comprising carbon blacks from Region I provide heretofore unachieved balance between macro-dispersion quality and MW sol .
 
Region II Carbon Black Samples
 
     Invention samples comprising carbon blacks having morphological properties (i.e., structure and surface area) of Region II in  FIG. 8 , and corresponding control samples described above made with such Region II carbon blacks are compared in the semi-log plot of  FIG. 11 . Specifically,  FIG. 11  shows the macro-dispersion values and MW sol  a values of the invention samples and corresponding control samples comprising the carbon blacks N234 and N110 at carbon black loading ranging from 40 phr to 70 phr and extender oil loading ranging from 0 phr to 10 phr. Excellent carbon black dispersion is seen in  FIG. 11  for all of the invention samples, representing preferred embodiments of elastomer composites in accordance with the present disclosure. The invention samples advantageously are below line  111  in  FIG. 11 , whereas all of the control samples have poorer dispersion, being above line  111 . In fact, the preferred embodiments shown in  FIG. 11  comprising carbon blacks from Region II fall below a D(%) value of 0.3%. Most preferred embodiments have a D(%) value not exceeding 0.2% at any MW sol  value. The data shown in  FIG. 11  clearly reveal that the macro-dispersion quality of the novel elastomer composites disclosed here comprising Region II carbon blacks, over a wide range of MW sol  values, is significantly superior to that achievable using comparable ingredients in prior dry mixing methods. The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 11  are described by the following equations:
 
 D (%)&lt;0.3%  (5)
 
when MW sol  is less than 0.35×10 6 ; and
 
log  D &lt;log(0.3)+2.8×[MW sol −(0.35×10 6 )]×10 −6   (6)
 
when 0.35×10 6 &lt;MW sol &lt;1.1×10 6 .
 
It will be recognized that D (%) of 0.30% is the threshold macro-dispersion quality for all carbon blacks in Region II for natural rubber masterbatches in accordance with the present invention, and 0.35×10 6  is the threshold MW sol  value. That is, none of the dry masterbatches achieved macro-dispersion quality of 0.30% or better at any MW sol  even after dry mixing sufficiently to degrade MW sol  below 0.35×10 6 , as described by Equation (5) above. When the MW sol  of the dry masterbatch control samples shown in  FIG. 11  is between 0.35×10 6  and 1.1×10 6 , the dispersion quality is even poorer. In contrast, the dispersion quality of the invention samples having MW sol  in that range remains excellent. The preferred embodiments shown in  FIG. 11  having MW sol  between 0.35×10 6  and 1.1×10 6  fall well below the preferred macro-dispersion limit of 0.2%. It can be seen that the elastomer composites of the invention comprising carbon blacks from Region II provide heretofore unachieved balance between macro-dispersion quality and MW sol .
 
Region III Carbon Black Samples
 
     Invention samples comprising carbon blacks having morphological properties (i.e., structures and surface area) of Region III in  FIG. 8 , and corresponding control samples described above made with such Region III carbon blacks are compared in the semi-log plot of  FIG. 12 . Specifically,  FIG. 12  shows the macro-dispersion values and MW sol  values of the invention samples and corresponding control samples comprising the carbon blacks N351 and Sterling 6740, at carbon black loading ranging from 30 phr to 70 phr and extender oil loading ranging from 0 phr to 20 phr. Excellent carbon black dispersion is seen in  FIG. 12  for all of the invention samples, representing preferred embodiments of elastomer composites in accordance with the present disclosure. All of the invention samples advantageously are below line  121  in  FIG. 12 , whereas all of the control samples have poorer dispersion, being above line  121 . In fact, the preferred embodiments shown in  FIG. 12 , comprising carbon blacks from Region III, fall at or below a D(%) value of 0.1%, even at an MW sol  value advantageously exceeding 0.3×10 6  and even 0.7×10 6 . The data shown in  FIG. 12  clearly reveals that the macro-dispersion quality of the novel elastomer composites disclosed here comprising Region III carbon black, over a wide range of MW sol  values, is significantly superior to that achievable using comparable ingredients in prior dry mixing methods. The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 12  are described by the following equations:
 
 D (%)&lt;0.1%  (7)
 
when MW sol  is less than 0.35×10 6 ; and
 
log  D &lt;log(0.1)+2.0×[MW sol −(0.30×10 6 )×10 −6 ]  (8)
 
when 0.30×10 6 &lt;MW sol &lt;1.1×10 6 .
 
It will be recognized that D (%) of 0.1% is the threshold macro-dispersion quality for all carbon blacks in Region III for natural rubber masterbatches in accordance with the present invention, and 0.3×10 6  is the threshold MW sol  value. That is, none of the dry masterbatches achieved macro-dispersion quality of 0.1% at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.35×10 6 , as described by Equation (7) above. When the MW sol  of the dry masterbatch control samples shown in  FIG. 12  is between 0.30×10 6  and 1.1×10 6 , the dispersion quality is even poorer. In contrast, the dispersion quality of the invention samples having MW sol  in that range remains excellent. The preferred embodiments shown in  FIG. 12  having MW sol  between 0.30×10 6  and 1.1×10 6  fall well below the preferred macro-dispersion limit of 0.2%, and, in fact, are at or below D(%) value of 0.1%. It can be seen that the elastomer composites of the present invention comprising carbon blacks from Region III provide heretofore unachieved balance between macro-dispersion quality and MW sol .
 
Additional Sample Comparisons
 
     The macro-dispersion values for the invention samples are shown graphically in the semi-long plots of  FIGS. 13 through 21 , as a function of their MW sol , values, as in FIGS.  8  through  12  discussed above. More specifically, in  FIGS. 13 through 21  all invention samples described above comprising a particular carbon black (being limited to those of a specific carbon black loading when so indicated) are shown together in a single semi-log plot together with the corresponding control samples. (See the legends above giving the reference numbers of the invention samples and control samples included in each figure.) Thus,  FIG. 13  shows the dispersion quality and MW sol  of invention and control samples described above comprising 55 phr N330 carbon black. The data shown in  FIG. 13  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention, comprising N330 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. Macro-dispersion for elastomer composites of the invention comprising N330 carbon black, as shown in  FIG. 13  is described by the following equations:
 
 D (%)&lt;1%  (9)
 
when MW sol &lt;0.6×10 6 ; and
 
log( D )&lt;log(1)+2.5×[MW sol −(0.6×10 6 )]× 10   −6   (10)
 
when 0.6×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the dry masticated masterbatches achieved macro-dispersion quality of 1.0% at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.6×10 6  (see Equation 9, above). In control samples comprising 55 phr N330 carbon black in which the MW sol  was maintained between 0.6×10 6  and 1.1×10 6 , the D(%) value is even higher, such as more than 4% undispersed area.
 
       FIG. 14  shows the dispersion quality and MW sol  of the invention and control samples described above comprising REGAL® 250 carbon black. Selected invention and control samples shown in  FIG. 14  comprised oil, as set forth above. The data shown in  FIG. 14  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising REGAL® 250 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising REGAL®D 250 carbon black, as shown in  FIG. 14  are described by the following equations:
   D (%)&lt;1%  (9) 
when MW sol &lt;0.6×10 6 ; and
 log( D )&lt;log(1)+2.5×[MW sol −(0.6×10 6 )]× 10   −6   (10) 
when 0.6×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.6×10 6 . In contrast, elastomer composites of the invention comprising Regal® 250 carbon black and having MW sol  above 0.6×10 6  have excellent macro-dispersion, such as D(%) less than 0.2%. Compound properties and performance characteristics for the invention and control samples shown in  FIG. 14 , comprising REGAL® 250 carbon black, are set forth in Table 27 below. It can be seen that invention sample No. 4 has exceptionally good resistance to crack growth, as indicated by its very low crack growth rate value of only 0.92 cm/million cycles. In fact, the invention sample is far superior to the corresponding control samples. This is believed to be due largely to the better MW sol  and macro-dispersion of carbon black in the invention sample, as discussed above.
 
     
       
         
           
               
             
               
                 TABLE 27 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing REGAL 250 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4)   @   100 C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 33 
                 60.63 
                 55.35 
                 181.26 
                 999.82 
                 4090.24 
                 675.0 
               
               
                 control 34 
                 73.58 
                 57.80 
                 235.14 
                 1293.88 
                 3978.24 
                 595.0 
               
               
                 control 35 
                 81.49 
                 58.65 
                 243.66 
                 1265.26 
                 4103.41 
                 613.0 
               
               
                 control 36 
                 84.04 
                 59.95 
                 244.23 
                 1215.87 
                 3960.32 
                 614.0 
               
               
                 control 37 
                 57.35 
                 56.75 
                 218.70 
                 1259.99 
                 4119.85 
                 502.0 
               
               
                 control 38 
                 60.10 
                 57.05 
                 216.75 
                 1206.60 
                 4023.65 
                 620.0 
               
               
                 control 39 
                 68.28 
                 57.25 
                 225.44 
                 1256.23 
                 4134.06 
                 621.0 
               
               
                 control 40 
                 77.40 
                 59.10 
                 255.15 
                 1330.87 
                 4059.01 
                 597.0 
               
               
                 control 41 
                 44.40 
                 56.25 
                 216.00 
                 1214.78 
                 4038.68 
                 618.0 
               
               
                 control 42 
                 47.96 
                 56.50 
                 214.53 
                 1202.93 
                 3944.05 
                 613.0 
               
               
                 control 43 
                 49.84 
                 57.05 
                 221.26 
                 1229.07 
                 4018.24 
                 611.0 
               
               
                 control 44 
                 50.10 
                 56.60 
                 210.50 
                 1140.90 
                 4058.33 
                 638.0 
               
               
                 control 45 
                 36.82 
                 52.90 
                 177.47 
                 982.86 
                 3790.56 
                 533.0 
               
               
                 control 46 
                 38.23 
                 54.50 
                 198.63 
                 1111.04 
                 3860.56 
                 629.0 
               
               
                 control 47 
                 35.35 
                 54.60 
                 199.03 
                 1110.00 
                 3871.49 
                 505.0 
               
               
                 control 48 
                 40.58 
                 55.50 
                 204.52 
                 1139.94 
                 3961.06 
                 632.0 
               
               
                 invention 4 
                 71.97 
                 57.00 
                 218.18 
                 1230.30 
                 4036.30 
                 611.0 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ 
                 Tan δ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 @ 0° C. 
                 @ 60° C. 
               
               
                   
               
               
                 control 33 
                 64.50 
                 2.00 
                 0.191 
                 0.167 
                 0.091 
               
               
                 control 34 
                 64.55 
                 1.83 
                 0.182 
                 0.155 
                 0.083 
               
               
                 control 35 
                 63.75 
                 2.38 
                 0.192 
                 0.150 
                 0.091 
               
               
                 control 36 
                 63.30 
                 1.42 
                 0.180 
                 0.162 
                 0.091 
               
               
                 control 37 
                 64.65 
                 3.00 
                 0.168 
                 0.176 
                 0.100 
               
               
                 control 38 
                 63.45 
                 2.99 
                 0.163 
                 0.184 
                 0.099 
               
               
                 control 39 
                 63.90 
                 2.17 
                 0.186 
                 0.170 
                 0.092 
               
               
                 control 40 
                 62.30 
                 1.69 
                 0.182 
                 0.175 
                 0.093 
               
               
                 control 41 
                 64.20 
                 2.84 
                 0.190 
                 0.189 
                 0.102 
               
               
                 control 42 
                 64.20 
                 3.24 
                 0.182 
                 0.168 
                 0.103 
               
               
                 control 43 
                 64.50 
                 3.52 
                 0.177 
                 0.183 
                 0.101 
               
               
                 control 44 
                 63.90 
                 3.50 
                 0.179 
                 0.185 
                 0.104 
               
               
                 control 45 
                 63.80 
                 3.86 
                 0.199 
                 0.197 
                 0.104 
               
               
                 control 46 
                 64.30 
                 3.94 
                 0.191 
                 0.184 
                 0.107 
               
               
                 control 47 
                 64.35 
                 3.81 
                 0.192 
                   
                 0.106 
               
               
                 control 48 
                 63.65 
                 3.46 
                 0.180 
                 0.182 
                 0.110 
               
               
                 invention 4 
                 64.70 
                 0.92 
                 0.190 
                 0.148 
                 0.096 
               
               
                   
               
            
           
         
       
     
       FIG. 15  shows the dispersion quality and MW sol  of the invention and control samples described above comprising BLACK PEARL® 800 carbon black at 55 phr loading. The data shown in  FIG. 15  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising Black Pearl® 800 carbon black, is significantly superior to that of the control samples. The macro-dispersion values for elastomer composites of the invention comprising Black Pearl® 800 carbon black, as shown in  FIG. 15 , are described by the following equations:
   D (%)&lt;1.5%  (11) 
when MW sol &lt;0.65×10 6 ; and
 log( D )&lt;log(1.5)+2.5×[MW sol −(0.65×10 6 )]×10 −6   (12) 
when 0.65×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.65×10 6 . In contrast, elastomer composites of the invention comprising Black Pearl® 800 carbon black and having MW sol  above 0.65×10 6  have excellent macro-dispersion, such as D(%) less than 0.2%. Compound properties and performance characteristics for the invention and control samples shown in  FIG. 15 , comprising Black Pearl® 800 carbon black, are set forth in Table 28 below. It can be seen that invention sample No. 8 has exceptionally good resistance to crack growth, as indicated by its very low crack growth rate value of only 0.27 cm/million cycles. In fact, the invention samples are far superior to the corresponding control samples. This is believed to be due largely to the better MW sol  and macro-dispersion of carbon black in the invention sample, as discussed above.
 
     
       
         
           
               
             
               
                 TABLE 28 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing BLACK PEARL 800 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4)   @   100 C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 113 
                 110.5 
                 66.4 
                 345.0 
                 1333.0 
                 3878.0 
                 598 
               
               
                 control 114 
                 109.0 
                 67.3 
                 367.0 
                 1427.0 
                 4033.0 
                 606 
               
               
                 control 115 
                 106.4 
                 67.2 
                 363.0 
                 1311.0 
                 3896.0 
                 610 
               
               
                 control 116 
                 105.7 
                 69.0 
                 322.0 
                 1202.0 
                 3856.0 
                 626 
               
               
                 control 117 
                 110.6 
                 67.1 
                 316.0 
                 1400.0 
                 4180.0 
                 616 
               
               
                 control 118 
                 118.9 
                 67.1 
                 310.0 
                 1395.0 
                 3967.0 
                 607 
               
               
                 control 119 
                 111.9 
                 67.7 
                 309.0 
                 1323.0 
                 4149.0 
                 634 
               
               
                 control 120 
                 110.6 
                 67.6 
                 373.0 
                 1188.0 
                 4199.0 
                 653 
               
               
                 control 121 
                 114.7 
                 66.3 
                 287.0 
                 1262.0 
                 4329.0 
                 667 
               
               
                 control 122 
                 110.6 
                 65.8 
                 288.0 
                 1223.0 
                 4217.0 
                 659 
               
               
                 control 123 
                 115.0 
                 67.5 
                 280.0 
                 1282.0 
                 4071.0 
                 624 
               
               
                 control 124 
                 116.5 
                 66.5 
                 309.0 
                 1388.0 
                 4166.0 
                 623 
               
               
                 control 125 
                 113.4 
                 65.4 
                 281.0 
                 1274.0 
                 3978.0 
                 631 
               
               
                 control 126 
                 101.4 
                 66.8 
                 280.0 
                 1222.0 
                 4206.0 
                 656 
               
               
                 control 127 
                 105.5 
                 66.4 
                 262.0 
                 1150.0 
                 4167.0 
                 670 
               
               
                 control 128 
                 110.7 
                 66.8 
                 292.0 
                 1301.0 
                 4209.0 
                 643 
               
               
                 invention 8 
                 131.3 
                 62.5 
                 227.0 
                 1291.0 
                 3418.0 
                 532 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ 
                 Tan δ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 @ 0° C. 
                 @ 60° C. 
               
               
                   
               
               
                 control 113 
                 44.7 
                 3.14 
                 0.148 
                 0.281 
                 0.184 
               
               
                 control 114 
                 45.0 
                 2.72 
                 0.125 
                 0.274 
                 0.185 
               
               
                 control 115 
                 47.0 
                 2.54 
                 0.163 
                 0.233 
                 0.171 
               
               
                 control 116 
                 46.6 
                 2.41 
                 0.194 
                 0.244 
                 0.163 
               
               
                 control 117 
                 40.9 
                 4.56 
                 0.086 
                 0.327 
                 0.214 
               
               
                 control 118 
                 41.8 
                 2.80 
                 0.112 
                 0.335 
                 0.225 
               
               
                 control 119 
                 41.7 
                 4.33 
                 0.091 
                 0.321 
                 0.216 
               
               
                 control 120 
                 42.1 
                 3.89 
                 0.095 
                 0.301 
                 0.207 
               
               
                 control 121 
                 39.2 
                 3.38 
                 0.075 
                 0.312 
                 0.256 
               
               
                 control 122 
                 38.7 
                 4.58 
                 0.108 
                 0.344 
                 0.236 
               
               
                 control 123 
                 40.2 
                 4.79 
                 0.103 
                 0.329 
                 0.232 
               
               
                 control 124 
                 41.7 
                 3.78 
                 0.102 
                 0.321 
                 0.209 
               
               
                 control 125 
                 38.9 
                 3.40 
                 0.076 
                 0.352 
                 0.248 
               
               
                 control 126 
                 38.1 
                 5.57 
                 0.070 
                 0.355 
                 0.241 
               
               
                 control 127 
                 38.2 
                 4.79 
                 0.073 
                 0.346 
                 0.254 
               
               
                 control 128 
                 39.4 
                 3.40 
                 0.113 
                 0.357 
                 0.23  
               
               
                 invention 8 
                 44.8 
                 0.27 
                 0.130 
                 0.297 
                 0.199 
               
               
                   
               
            
           
         
       
     
       FIG. 16  shows the dispersion quality and MW sol  of the invention and control samples described above comprising N326 carbon black at 55 phr loading. The data shown in  FIG. 16  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising N326 carbon black is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising N326 carbon black, as shown in  FIG. 16 , are described by the following equations:
   D (%)&lt;1%  (13) 
when MW sol &lt;0.7×10 6 ; and
 log( D )&lt;log(1)+2.5×[MW sol −(0.7×10 6 )]× 10   −6   (14) 
when 0.7×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.7×10 6 . In contrast, elastomer composites of the invention comprising N326 carbon black and having MW sol  above 0.7×10 6  have excellent macro-dispersion, such as D(%) not greater than 0.2%. Compound properties and performance characteristics for the invention and control samples shown in  FIG. 16 , comprising N326 carbon black are set forth in Table 29 below. It can be seen that invention sample No. 9 has exceptionally good resistance to crack growth, as indicated by its very low crack growth rate value of only 0.77 cm/million cycles. In fact, the invention sample is far superior to the corresponding control samples. This is believed to be due largely to the better MW sol  and macro-dispersion of carbon black in the invention sample, as discussed above.
 
     
       
         
           
               
             
               
                 TABLE 29 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing N326 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4) @ 100° C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 145 
                 64.6 
                 60.5 
                 289 
                 1713 
                 3921 
                 548 
               
               
                 control 146 
                 88.2 
                 62.4 
                 340 
                 1802 
                 4094 
                 553 
               
               
                 control 147 
                 91.7 
                 63.3 
                 391 
                 1917 
                 3991 
                 528 
               
               
                 control 148 
                 96.8 
                 64.3 
                 326 
                 1664 
                 4045 
                 572 
               
               
                 control 149 
                 62.4 
                 61.5 
                 310 
                 1763 
                 4029 
                 552 
               
               
                 control 150 
                 67.7 
                 62.6 
                 326 
                 1855 
                 4055 
                 551 
               
               
                 control 151 
                 76.5 
                 60.6 
                 287 
                 1641 
                 4015 
                 575 
               
               
                 control 152 
                 79.4 
                 63.6 
                 329 
                 1720 
                 3980 
                 559 
               
               
                 control 153 
                 57.2 
                 60.1 
                 282 
                 1623 
                 3968 
                 579 
               
               
                 control 154 
                 57.2 
                 62.8 
                 354 
                 1889 
                 3879 
                 525 
               
               
                 control 155 
                 57.3 
                 62.2 
                 323 
                 1763 
                 3975 
                 556 
               
               
                 control 156 
                 60.1 
                 61.9 
                 310 
                 1667 
                 3918 
                 564 
               
               
                 control 157 
                 45.1 
                 61.2 
                 328 
                 1748 
                 3768 
                 533 
               
               
                 control 158 
                 50.1 
                 60.6 
                 315 
                 1740 
                 3817 
                 546 
               
               
                 control 159 
                 53.2 
                 61.3 
                 306 
                 1675 
                 3886 
                 563 
               
               
                 control 160 
                 50.5 
                 62.6 
                 331 
                 1752 
                 3884 
                 549 
               
               
                 invention 9 
                 77.8 
                 60.9 
                 277 
                 1563 
                 4167 
                 593 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ 
                 Tan δ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 @ 0° C. 
                 @ 60° C. 
               
               
                   
               
               
                 control 145 
                 57.8 
                 2.84 
                 0.0952 
                 0.225 
                 0.129 
               
               
                 control 146 
                 58.1 
                 2.52 
                 0.0887 
                 0.217 
                 0.126 
               
               
                 control 147 
                 57.6 
                 2.03 
                 0.0946 
                 0.205 
                 0.123 
               
               
                 control 148 
                 56.3 
                 1.63 
                 0.0927 
                 0.221 
                 0.129 
               
               
                 control 149 
                 57.2 
                 3.39 
                 0.0827 
                 0.234 
                 0.142 
               
               
                 control 150 
                 56.8 
                 2.77 
                 0.0866 
                 0.234 
                 0.150 
               
               
                 control 151 
                 55.6 
                 2.61 
                 0.0933 
                 0.241 
                 0.149 
               
               
                 control 152 
                 54.5 
                 2.79 
                 0.0857 
                 0.249 
                 0.155 
               
               
                 control 153 
                 55.4 
                 3.12 
                 0.0911 
                 0.258 
                 0.170 
               
               
                 control 154 
                 56.0 
                 3.35 
                 0.0858 
                 0.241 
                 0.147 
               
               
                 control 155 
                 55.4 
                 3.63 
                 0.0811 
                 0.254 
                 0.152 
               
               
                 control 156 
                 54.9 
                 3.55 
                 0.0906 
                 0.261 
                 0.153 
               
               
                 control 157 
                 55.5 
                 3.02 
                 0.0931 
                 0.254 
                 0.149 
               
               
                 control 158 
                 55.4 
                 3.81 
                 0.0914 
                 0.249 
                 0.150 
               
               
                 control 159 
                 54.9 
                 3.23 
                 0.0933 
                 0.240 
                 0.158 
               
               
                 control 160 
                 55.2 
                 3.19 
                 0.0942 
                 0.246 
                 0.163 
               
               
                 invention 9 
                 58.4 
                 0.77 
                 0.0939 
                 0.225 
                 0.136 
               
               
                   
               
            
           
         
       
     
       FIG. 17  shows the dispersion quality and MW sol  of the invention and control samples described above comprising REGAL (trademark) 660 carbon black. Selected invention and control samples shown in  FIG. 17  comprised oil, as set forth above. The data shown in  FIG. 17  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising REGAL® 660 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising REGAL® 660 carbon black, as shown in  FIG. 17  are described by the following equations:
   D (%)&lt;1%  (15) 
when MW sol &lt;0.6×10 6 ; and
 log( D )&lt;log(1)+2.5×[MW sol −(0.6×10 6 )]× 10   −6   (16) 
when 0.6×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.6×10 6 . In contrast, elastomer composites of the invention comprising Regale 660 carbon black and having MW sol  above 0.6×10 6  have excellent macro-dispersion, such as D(%) less than 0.2%. Compound properties and performance characteristics for the invention sample No. 10 and various control samples shown in  FIG. 17 , comprising Regale 660 carbon black, are set forth in Table 30 below. It can be seen that invention sample No. 10 has exceptionally good resistance to crack growth, as indicated by its very low crack growth rate value of only 0.69 cm/million cycles. In fact, the invention samples are far superior to the corresponding control samples. This is believed to be due largely to the better MW sol  and macro-dispersion of carbon black in the invention sample, as discussed above.
 
     
       
         
           
               
             
               
                 TABLE 30 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing REGAL 660 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4) @ 100° C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 177 
                   
                 61.0 
                 213 
                 942 
                   
                 702 
               
               
                 control 178 
                 87.6 
                 63.2 
                 232 
                 943 
                 4002 
                 694 
               
               
                 control 179 
                 87.1 
                 64.9 
                 285 
                 1134 
                 4016 
                 644 
               
               
                 control 180 
                 85.6 
                 64.0 
                 271 
                 1198 
                 4058 
                 618 
               
               
                 control 181 
                 80.1 
                 61.0 
                 206 
                 945 
                 4098 
                 661 
               
               
                 control 182 
                 93.4 
                 59.0 
                 192 
                 835 
                 3924 
                 733 
               
               
                 control 183 
                 89.0 
                 61.0 
                 215 
                 920 
                 4134 
                 698 
               
               
                 control 184 
                 83.4 
                 62.4 
                 223 
                 996 
                 4236 
                 694 
               
               
                 control 185 
                 70.1 
                 60.0 
                 178 
                 794 
                 3768 
                 717 
               
               
                 control 186 
                 69.8 
                 60.3 
                 196 
                 920 
                 4051 
                 666 
               
               
                 control 187 
                 76.7 
                 63.5 
                 166 
                 866 
                 4157 
                 720 
               
               
                 control 188 
                 72.1 
                 62.0 
                 191 
                 883 
                 4182 
                 704 
               
               
                 control 189 
                 54.3 
                 61.2 
                 222 
                 1079 
                 4240 
                 674 
               
               
                 control 190 
                 55.7 
                 61.1 
                 193 
                 942 
                 4125 
                 692 
               
               
                 control 191 
                   
                 65.0 
               
               
                 control 192 
                 61.1 
                 60.4 
                 191 
                 902 
                 4189 
                 710 
               
               
                 invention 10 
                 88.1 
                 62.9 
                 249 
                 1202 
                 4292 
                 634 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ 
                 Tan δ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 @ 0° C. 
                 @ 60° C. 
               
               
                   
               
               
                 control 177 
                 54.6 
                   
                   
                   
                 0.131 
               
               
                 control 178 
                 55.6 
                 2.34 
                 0.1649 
                 0.194 
                 0.129 
               
               
                 control 179 
                 53.7 
                 2.78 
                 0.1620 
                 0.200 
                 0.140 
               
               
                 control 180 
                 52.9 
                 2.98 
                 0.1385 
                 0.220 
                 0.153 
               
               
                 control 181 
                 51.0 
                 3.41 
                 0.1189 
                 0.267 
                 0.185 
               
               
                 control 182 
                 49.9 
                 3.11 
                 0.1076 
                 0.270 
                 0.194 
               
               
                 control 183 
                 50.1 
                 3.15 
                 0.1086 
                 0.264 
                 0.192 
               
               
                 control 184 
                 48.0 
                 3.11 
                 0.1085 
                 0.284 
                 0.208 
               
               
                 control 185 
                 47.5 
                 4.59 
                 0.0937 
                 0.306 
                 0.209 
               
               
                 control 186 
                 48.5 
                 4.06 
                 0.1008 
                 0.295 
                 0.211 
               
               
                 control 187 
                 47.7 
                 3.53 
                 0.1041 
                 0.297 
                 0.198 
               
               
                 control 188 
                 47.8 
                 3.79 
                 0.0985 
                 0.285 
                 0.207 
               
               
                 control 189 
                 47.5 
                 3.71 
                 0.0957 
                 0.306 
                 0.203 
               
               
                 control 190 
                 46.8 
                 4.14 
                 0.0962 
                 0.300 
                 0.200 
               
               
                 control 191 
                 47.4 
                   
                   
                   
                 0.226 
               
               
                 control 192 
                 46.5 
                 4.78 
                 0.0897 
                 0.301 
                 0.226 
               
               
                 invention 10 
                 48.2 
                 0.69 
                 0.0942 
                 0.271 
                 0.178 
               
               
                   
               
            
           
         
       
     
       FIG. 18  shows the dispersion quality and MW sol  of the invention and control samples described above comprising N234 carbon black. Selected invention and control samples shown in  FIG. 18  comprised oil, as set forth above. The data shown in  FIG. 18  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising N234 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising N234 carbon black, as shown in  FIG. 18  are described by the following equations:
   D (%)&lt;0.3%  (17) 
when MW sol &lt;0.35×10 6 ; and
 log( D )&lt;log(0.3)+2.8×[MW sol −(0.35×10 6 )]×10 −6   (18) 
when 0.35×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 0.3% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.35×10 6  In contrast, elastomer composites of the invention comprising N234 carbon black and having MW sol  greater than 0.35×10 6  have excellent macro-dispersion, such as D(%) not more than 0.3% or even 0.2%. Compound properties and performance characteristics for invention sample No. 14 and various control samples shown in  FIG. 18 , comprising N234 carbon black, are set forth in Table 31 below. It can be seen that invention sample No. 14 has good resistance to crack growth, as indicated by its crack growth rate value of only 2.08 cm/million cycles.
 
     
       
         
           
               
             
               
                 TABLE 31 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing N234 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4) @ 100° C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 273 
                 94.5 
                 68.0 
                 386 
                 2077 
                 3718 
                 511 
               
               
                 control 274 
                 121.6 
                 69.6 
                 464 
                 2299 
                 3925 
                 501 
               
               
                 control 275 
                 121.4 
                 72.5 
                 564 
                 2545 
                 3994 
                 472 
               
               
                 control 276 
                 132.2 
                 71.9 
                 511 
                 2259 
                 3964 
                 520 
               
               
                 control 277 
                 79.6 
                 68.5 
                 468 
                 2453 
                 3857 
                 469 
               
               
                 control 278 
                 96.3 
                 70.0 
                 531 
                 2499 
                 3874 
                 469 
               
               
                 control 279 
                 108.6 
                 69.0 
                 406 
                 2131 
                 3863 
                 532 
               
               
                 control 280 
                 120.3 
                 71.5 
                 476 
                 2273 
                 3852 
                 502 
               
               
                 control 281 
                 76.4 
                 69.7 
                 556 
                 2723 
                 4027 
                 451 
               
               
                 control 282 
                 89.8 
                 69.8 
                 553 
                 2574 
                 3896 
                 465 
               
               
                 control 283 
                 93.6 
                 69.6 
                 506 
                 2416 
                 3867 
                 475 
               
               
                 control 284 
                 106.7 
                 71.8 
                 526 
                 2384 
                 3788 
                 484 
               
               
                 control 285 
                 73.3 
                 69.3 
                 529 
                 2586 
                 3831 
                 444 
               
               
                 control 286 
                 79.2 
                 69.5 
                 531 
                 2574 
                 3856 
                 456 
               
               
                 control 287 
                 77.8 
                 70.7 
                 544 
                 2486 
                 3834 
                 461 
               
               
                 control 288 
                 82.8 
                 71.2 
                 485 
                 2295 
                 3799 
                 499 
               
               
                 invention 14 
                 82.6 
                 71.5 
                 500 
                 2440 
                 3883 
                 531 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ 
                 Tan δ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 @ 0° C. 
                 @ 60° C. 
               
               
                   
               
               
                 control 273 
                 45.9 
                 2.14 
                 0.0563 
                 0.285 
                 0.183 
               
               
                 control 274 
                 47.2 
                 1.84 
                 0.0583 
                 0.274 
                 0.173 
               
               
                 control 275 
                 46.1 
                 1.70 
                 0.0538 
                 0.284 
                 0.172 
               
               
                 control 276 
                 46.9 
                 1.21 
                 0.0620 
                 0.270 
                 0.173 
               
               
                 control 277 
                 47.1 
                 2.22 
                 0.0628 
                 0.305 
                 0.173 
               
               
                 control 278 
                 45.8 
                 2.40 
                 0.0634 
                 0.299 
                 0.196 
               
               
                 control 279 
                 45.4 
                 2.00 
                 0.0680 
                 0.306 
                 0.198 
               
               
                 control 280 
                 44.2 
                 1.81 
                 0.0646 
                 0.298 
                 0.198 
               
               
                 control 281 
                 46.3 
                 3.10 
                 0.0598 
                 0.293 
                 0.174 
               
               
                 control 282 
                 46.5 
                 2.33 
                 0.0537 
                 0.307 
                 0.182 
               
               
                 control 283 
                 46.4 
                 2.41 
                 0.0594 
                 0.309 
                 0.186 
               
               
                 control 284 
                 44.2 
                 1.99 
                 0.0579 
                 0.304 
                 0.190 
               
               
                 control 285 
                 47.0 
                 2.99 
                 0.0554 
                 0.295 
                 0.178 
               
               
                 control 286 
                 45.6 
                 2.85 
                 0.0551 
                 0.294 
                 0.172 
               
               
                 control 287 
                 45.4 
                 2.93 
                 0.0569 
                 0.305 
                 0.187 
               
               
                 control 288 
                 44.0 
                 2.39 
                 0.0647 
                 0.316 
                 0.198 
               
               
                 invention 14 
                 45.1 
                 2.08 
                 0.0698 
                 0.310 
                 0.198 
               
               
                   
               
            
           
         
       
     
       FIG. 19  shows the dispersion quality and MW sol  of the invention and control samples described above comprising N110 carbon black at 55 phr loading. The data shown in  FIG. 19  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising N110 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising N110 carbon black, as shown in  FIG. 19 , are described by the following equations:
   D (%)&lt;0.5%  (19) 
when MW sol &lt;0.35×10 6 ; and
 log( D )&lt;log(0.5)+2.5×[MW sol −(0.6×10 6 )]×10 −   (20) 
when 0.35×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 0.5% at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.35×10 6 . In contrast, elastomer composites of the invention comprising N110 carbon black and having MW sol  above 0.35×10 6  have excellent macro-dispersion, such as D(%) less than 0.2%.
 
       FIG. 20  shows the dispersion quality and MW sol  of invention sample 22 and the control samples described above comprising N351 carbon black at 33 phr loading. The data shown in  FIG. 20  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising N351 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising N351 carbon black, as shown in  FIG. 20 , are described by the following equations:
   D (%)&lt;0.3%  (21) 
when MW sol &lt;0.55×10 6 ; and
 log( D )&lt;log(0.3)+2.0×[MW sol −(0.55×10 6 )]×10 −6   (22) 
when 0.55×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 1.0% at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.35×10 6 . In contrast, elastomer composites of the invention comprising N351 carbon black and having MW sol  above 0.35×10 6  have excellent macro-dispersion, such as D(%) less than 0.2%.
 
       FIG. 21  shows the dispersion quality and MW sol  of the invention sample No. 23 and control samples described above comprising STERLING® 6740 carbon black at 55 phr loading. The data shown in  FIG. 21  clearly reveals that the macro-dispersion quality of the novel elastomer composites of the invention comprising STERLING® 6740 carbon black, over a wide range of MW sol  values, is significantly superior to that of the control samples. The macro-dispersion values for the elastomer composites of the invention comprising STERLING® 6740 carbon black, as shown in  FIG. 21  are described by the following equations:
   D (%)&lt;0.1%  (23) 
when MW sol &lt;0.3×10 6 ; and
 log( D )&lt;log(0.1)+2.0×[MW sol −(0.3×10 6 )]×10 −6   (24) 
when 0.3×10 6 &lt;MW sol &lt;1.1×10 6 .
 
None of the control samples achieved macro-dispersion quality of 0.1% or even 0.2% at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.3×10 6 . In contrast, elastomer composites of the invention comprising STERLING® 6740 carbon black and having MW sol  above 0.3×10 6  have excellent macro-dispersion, such as D(%) less than 0.2% and even less than 0.1%. Compound properties and performance characteristics for invention sample No. 23 and the control samples shown in  FIG. 21 , comprising STERLING® 6740 carbon black, are set forth in Table 32 below. It can be seen that invention sample No. 23 has good resistance to crack growth, as indicated by its crack growth rate value of only 0.91 cm/million cycles. In fact, the invention sample is far superior to the corresponding control samples. This is believed to be due largely to the better MW sol  and macro-dispersion of carbon black in the invention sample, as discussed above.
 
     
       
         
           
               
             
               
                 TABLE 32 
               
               
                   
               
               
                 Compound Properties of NR Compounds 
               
               
                 Containing STERLING 6740 Carbon Black at 55 phr Loading 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Mooney 
                   
                 E100 
                 E300 
                 Tensile 
                 EB 
               
               
                 Sample No. 
                 ML(1 + 4) @ 100° C. 
                 Hardness 
                 (psi) 
                 (psi) 
                 (psi) 
                 (%) 
               
               
                   
               
               
                 control 412 
                 75.50 
                 65.1 
                 467.0 
                 2308.0 
                 3519 
                 451 
               
               
                 control 413 
                 85.70 
                 65.7 
                 469.0 
                 2314.0 
                 3655 
                 479 
               
               
                 control 414 
                 92.70 
                 67.7 
                 462.0 
                 2243.0 
                 3613 
                 472 
               
               
                 control 415 
                 99.60 
                 66.9 
                 492.0 
                 2260.0 
                 3572 
                 477 
               
               
                 control 416 
                 74.50 
                 65.8 
                 521.0 
                 2468.0 
                 3584 
                 445 
               
               
                 control 417 
                 78.20 
                 67.1 
                 502.0 
                 2372.0 
                 3445 
                 436 
               
               
                 control 418 
                 82.00 
                 66.0 
                 534.0 
                 2418.0 
                 3604 
                 453 
               
               
                 control 419 
                 86.10 
                 67.8 
                 540.0 
                 2330.0 
                 3620 
                 475 
               
               
                 control 420 
                 66.70 
                 66.0 
                 515.0 
                 2382.0 
                 3468 
                 444 
               
               
                 control 421 
                 76.30 
                 67.8 
                 488.0 
                 2310.0 
                 3375 
                 440 
               
               
                 control 422 
                 78.30 
                 65.8 
                 548.6 
                 2440.0 
                 3549 
                 442 
               
               
                 control 423 
                 82.10 
                 66.5 
                 487.0 
                 2219.0 
                 3452 
                 466 
               
               
                 control 424 
                 64.80 
                 66.5 
                 541.0 
                 2448.0 
                 3397 
                 425 
               
               
                 control 425 
                 67.50 
                 66.5 
                 524.0 
                 2374.0 
                 3474 
                 445 
               
               
                 control 426 
                 70.30 
                 66.9 
                 546.0 
                 2351.0 
                 3428 
                 446 
               
               
                 control 427 
                 71.00 
                 68.1 
                 554.0 
                 2340.0 
                 3322 
                 435 
               
               
                 invention 23 
                 110.50 
                 64.8 
                 453.6 
                 2241.0 
                 3324 
                 443 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Crack Growth Rate 
                 Abrasion loss 
                 Tan δ @ 
                 Tan δ @ 
               
               
                 Sample No. 
                 Rebound 
                 (cm/million cycles) 
                 (g) 
                 0° C. 
                 60° C. 
               
               
                   
               
               
                 control 412 
                 59.8 
                 5.04 
                 0.127 
                 0.202 
                 0.107 
               
               
                 control 413 
                 60.0 
                 3.63 
                 0.128 
                 0.203 
                 0.108 
               
               
                 control 414 
                 59.3 
                 3.96 
                 0.126 
                 0.208 
                 0.114 
               
               
                 control 415 
                 58.8 
                 4.56 
                 0.12 
                 0.217 
                 0.118 
               
               
                 control 416 
                 60.3 
                 5.67 
                 0.117 
                 0.188 
                 0.094 
               
               
                 control 417 
                 60.0 
                 4.67 
                 0.112 
                 0.202 
                 0.104 
               
               
                 control 418 
                 59.3 
                 4.23 
                 0.125 
                 0.204 
                 0.105 
               
               
                 control 419 
                 57.5 
                 3.22 
                 0.122 
                 0.218 
                 0.117 
               
               
                 control 420 
                 60.0 
                 4.23 
                 0.131 
                 0.204 
                 0.099 
               
               
                 control 421 
                 58.8 
                 3.84 
                 0.127 
                 0.206 
                 0.105 
               
               
                 control 422 
                 59.8 
                 3.98 
                 0.126 
                 0.210 
                 0.106 
               
               
                 control 423 
                 56.8 
                 3.85 
                 0.12 
                 0.213 
                 0.117 
               
               
                 control 424 
                 58.3 
                 4.54 
                 0.131 
                 0.200 
                 0.104 
               
               
                 control 425 
                 58.8 
                 3.65 
                 0.129 
                 0.207 
                 0.100 
               
               
                 control 426 
                 58.0 
                 3.07 
                 0.134 
                 0.211 
                 0.110 
               
               
                 control 427 
                 56.9 
                 3.25 
                 0.126 
                 0.217 
                 0.115 
               
               
                 invention 23 
                 57.3 
                 0.91 
                 0.1642 
                 0.204 
                 0.124 
               
               
                   
               
            
           
         
       
     
     Addition Examples 
     Cured Samples 
     A number of the masterbatch samples described above, including both selected invention samples and corresponding control samples, were cured and tested. Specifically, samples were mixed accordingly to Stage II in Table 8, above, using the formulation of Table 9, to produce a final compound. The final compound in each case was then cured in a mold using standard techniques at about 150° C. until substantially complete cure was achieved. Performance characteristics of the cured samples were determined by measuring their respective crack growth rates in accordance with the measurement technique set forth above, i.e., using a rotating flexing machine per ASTM D3629-94. The rotating type flexing machine used to measure crack growth is commercially available and well known. It is discussed, for example, in the Proceedings of the International Rubber Conference, 1995 (Kobe, Japan), Paper No. 27A-6 (p. 472-475). The compounds were tested at 100° C. and at a 45° flexing angle. It is generally accepted by those skilled in the art that crack growth rate in such compounds is affected by the molecular weight of the natural rubber and the dispersion quality of the carbon black i.e., by the MW sol  and D(%) values of the compounds. Higher MW sol  and lower D(%) correlate well with reduced crack growth rate. The crack growth rate and other information for invention samples nos. 9, 10 and 16 are set forth in Table 33 below. The corresponding test results for corresponding control samples is set forth in Table 34 below, grouped by choice of carbon black. Also, Tan δ max  @ 60° C. was measured for invention samples nos. 24-32 and for corresponding control samples. The Tan δ max  @ 60° C. values for the invention samples are set forth in Table 35 below. The corresponding test results for control samples is set forth in Table 36 below. 
     Control samples No. 444-450 shown in Table 36 were made in accordance with the procedures described above for control sample code M2D1 using RSS1 natural rubber. All used carbon black N234 at the loading level (phr) shown in Table 36, along with 5 phr extender oil. 
     
       
         
           
               
             
               
                 TABLE 33 
               
             
            
               
                   
               
               
                 Crack Growth Rate of Invention Samples 
               
            
           
           
               
               
               
               
            
               
                 Invention 
                   
                   
                   
               
               
                 Sample No. 
                 CB/Loading/Oil 
                 Mw sol  (K) 
                 CGR (cm/million cycles) 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 9 
                 N326/55/0 
                 666 
                 0.77 
               
               
                 10 
                 R660/55/0 
                 678 
                 0.69 
               
               
                 16 
                 N234/55/0 
                 500 
                 0.88 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 34 
               
             
            
               
                   
               
               
                 Crack Growth Rate of Control Samples 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                 CGR 
                   
                 Sample 
                 Mw sol   
                 CGR 
               
               
                 Code 
                 No. 
                 (K) 
                 (cm/million cycles) 
                 Code 
                 No. 
                 (K) 
                 (cm/million cycles) 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 N234/55 phr/0 
                   
                 N326/55 phr/0 
               
               
                   
                 RSS1 
                   
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 M1D1 
                 273 
                 585 
                 2.14 
                 M1D1 
                 145 
                 550 
                 2.84 
               
               
                 M1D2 
                 274 
                 669 
                 1.84 
                 M1D2 
                 146 
                 636 
                 2.52 
               
               
                 M1D3 
                 275 
                 759 
                 1.70 
                 M1D3 
                 147 
                 650 
                 2.03 
               
               
                 M1D4 
                 276 
                 896 
                 1.21 
                 M1D4 
                 148 
                 724 
                 1.63 
               
               
                 M2D1 
                 277 
                 580 
                 2.22 
                 M2D1 
                 149 
                 517 
                 3.39 
               
               
                 M2D2 
                 278 
                 602 
                 2.40 
                 M2D2 
                 150 
                 572 
                 2.77 
               
               
                 M2D3 
                 279 
                 631 
                 2.00 
                 M2D3 
                 151 
                 613 
                 2.61 
               
               
                 M2D4 
                 280 
                 667 
                 1.81 
                 M2D4 
                 152 
                 696 
                 2.79 
               
               
                 M3D1 
                 281 
                 457 
                 3.10 
                 M3D1 
                 153 
                 489 
                 3.12 
               
               
                 M3D2 
                 282 
                 476 
                 2.33 
                 M3D2 
                 154 
                 521 
                 3.35 
               
               
                 M3D3 
                 283 
                 493 
                 2.41 
                 M3D3 
                 155 
                 504 
                 3.63 
               
               
                 M3D4 
                 384 
                 495 
                 1.99 
                 M3D4 
                 156 
                 538 
                 3.55 
               
               
                 M4D1 
                 285 
                 372 
                 2.99 
                 M4D1 
                 157 
                 415 
                 3.02 
               
               
                 M4D2 
                 286 
                 382 
                 2.85 
                 M4D2 
                 158 
                 447 
                 3.81 
               
               
                 M4D3 
                 287 
                 381 
                 2.93 
                 M4D3 
                 159 
                 466 
                 3.23 
               
               
                 M4D4 
                 288 
                 403 
                 2.39 
                 M4D4 
                 160 
                 469 
                 3.19 
               
            
           
           
               
               
               
               
            
               
                   
                 Regal 660/55 phr/0 
                   
                 Regal 660/55 phr/0 
               
               
                   
                 RSS1 
                   
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 M1D1 
                 177 
                 674 
                   
                 M3D1 
                 185 
                 473 
                 4.59 
               
               
                 M1D2 
                 178 
                 792 
                 2.34 
                 M3D2 
                 186 
                 506 
                 4.06 
               
               
                 M1D3 
                 179 
                 891 
                 2.78 
                 M3D3 
                 187 
                 562 
                 3.53 
               
               
                 M1D4 
                 180 
                 676 
                 2.98 
                 M3D4 
                 188 
                 559 
                 3.79 
               
               
                 M2D1 
                 181 
                 598 
                 3.41 
                 M4D1 
                 189 
                 401 
                 3.71 
               
               
                 M2D2 
                 182 
                 602 
                 3.11 
                 M4D2 
                 190 
                 426 
                 4.14 
               
               
                 M2D3 
                 183 
                 697 
                 3.15 
                 M4D3 
                 191 
                 466 
               
               
                 M2D4 
                 184 
                 659 
                 3.11 
                 M4D4 
                 192 
                 449 
                 4.78 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 35 
               
             
            
               
                   
               
               
                 Tan δ at 60° C. for Invention Samples 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Invention 
                 N234 Loading/ 
                   
                 Max.Tan δ @ 
               
               
                   
                 Sample No. 
                 Oil (phr) 
                 Mw sol  (K) 
                 60° C. 
               
               
                   
                   
               
               
                   
                 24 
                 48/5 
                 569 
                 0.169 
               
               
                   
                 25 
                 53/5 
                 485 
                 0.176 
               
               
                   
                 26 
                 58/5 
                 447 
                 0.191 
               
               
                   
                 27 
                 63/5 
                 403 
                 0.219 
               
               
                   
                 28 
                 68/5 
                 378 
                 0.227 
               
               
                   
                 29 
                 49/5 
                 618 
                 0.159 
               
               
                   
                 30 
                 54/5 
                 482 
                 0.171 
               
               
                   
                 31 
                 63/5 
                 390 
                 0.228 
               
               
                   
                 32 
                 65/5 
                 325 
                 0.224 
               
               
                   
                   
               
            
           
         
       
     
                     TABLE 36                  Tan δ at 60° C. for Control Samples                                     Mw   D   N234 Loading/   Max.Tan D       Sample No.   (K)   (%)   Oil (phr)   (@60° C.)               444   428   0.25   37/5   0.154       445   409   0.37   42/5   0.170       446   379   0.42   48/5   0.179       447   361   0.58   51/5   0.195       448   366   0.27   53/5   0.212       449   290   0.39   58/5   0.215       450   296   0.64   63/5   0.245                    
It can be seen from a comparison of Table 33 and 34 that advantageously lower crack growth rate is achieved by the invention samples, compared to the control samples. Lower crack growth rate correlates with good durability and related characteristics for numerous applications, including tire applications and the like. In addition, it can be seen from a comparison of Tables 35 and 36 that better Tan δ max  values are achieved by the invention samples, that is, values which are lower than the values of the control sample. Accordingly, improved performance is achieved by the invention samples for numerous product applications including, for example, tire applications and the like requiring low hysteresis for correspondingly low rolling resistance.
 
     The advantageous performance characteristics of the elastomer composites of the invention are exemplified by the crack growth rate of invention sample no. 16 comprising N234 carbon black and corresponding test results for control samples nos. 273 to 288 shown graphically in  FIG. 22 . Specifically,  FIG. 22  clearly demonstrates a correlation between MW sol  and crack growth rate for the control samples, as well as the advantageous impact of excellent macro-dispersion in the elastomer composites of the present invention. It should be understood that the MW sol  values shown in  FIGS. 22-24  and in Tables 33-36 are for the masterbatch materials prior to cure. The molecular weight of the cured material is understood to correlate well to the MW sol  value of the uncured masterbatch. The crack growth rate of the control samples over an MW sol  range of about 0.25×10 6  to 0.6×10 6  is seen to fit well along a straight line correlation to MW sol . In contrast, the invention sample no. 16 at MW sol  0.5×10 6  has significantly better (i.e., lower) crack growth rate than any of the corresponding control samples, due to the better macro-dispersion D(%) of the invention sample. This is further established by the similar showing in  FIG. 23 , wherein the crack growth rate of invention sample no. 9 comprising N326 carbon black is seen to be significantly lower than that of any of the corresponding control samples nos. 145 to 160, and is well below the correlation line. Likewise in  FIG. 24  the excellent macro-dispersion of invention sample no. 10 is seen to result again in a crack growth value which lies far below the correlation line between crack growth rate and MW sol  established by the corresponding control samples nos. 177 to 192. In  FIG. 25 , the max tan δ at 60° C. is shown graphically to be better, i.e., lower, for invention samples nos. 24 to 28 and invention samples nos. 29 to 32 than for corresponding control samples nos. 444 to 450. 
     The superior crack growth results discussed above for elastomer composites of the present invention not only demonstrates advantageous fatigue properties, but also indicates advantageous fracture properties, such as excellent tear and cut-and-chip resistance. The superior hysteresis results discussed above for the elastomer composites of this invention not only demonstrate advantageously low rolling resistance (and correspondingly higher fuel economy) for motor vehicle tire applications, but also indicates advantageous improvement in related performance properties, such as reduced heat build-up. One or more of these superior properties, fatigue and fracture resistance, low hysteresis, low heat build-up, etc., render elastomer composites of the present invention well suited for use in commercial applications such as tire applications and in industrial rubber products. Regarding tire applications, various preferred embodiments of the invention are particularly well-suited for use as: tire tread, especially in tread for radial and bias truck tires, off-the-road (“OTR”) tires, airplane tires and the like; sub-tread; wire skim; sidewalls; cushion gum for retread tires; and similar tire applications. The superior performance characteristics achieve by various preferred embodiments of the invention can provide improved tire durability, tread life and casing life, better fuel economy for the motor vehicle and other advantages. Regarding industrial rubber products, various preferred embodiments of the invention are particularly well-suited for use as: engine mounts, hydro-mounts, bridge bearings and seismic isolators, tank tracks or tread, mining belts and similar products applications. The superior performance characteristics achieved by various preferred embodiments of the invention can provide improved fatigue life, durability and other advantages for such product applications. 
       FIGS. 26-29  are graphical representations of carbon black morphology, structure (DBPA) and surface area (CTAB), corresponding generally to  FIG. 8 . Carbon black morphology region  261  in  FIG. 26  includes carbon blacks currently in commercial use for OTR tire tread applications. Arrow  262  indicates the direction in which region  261  can be advantageously extended in accordance with the present invention. Performance characteristics such as cut-and-chip resistance, crack growth resistance and tear resistance are understood to improve generally in the direction of trend arrow  262  subject, however, in the past, to offsetting degradation of these and other characteristics due to reduced molecular weight of the natural rubber and/or poorer macro-dispersion resulting from the use of such higher surface area, lower structure carbon blacks. Elastomer composites of the present invention can employ such lower structure, higher surface area carbon black indicated by trend arrow  262  to achieve significantly improved OTR trend materials, in view of their excellent macro-dispersion and MW sol . 
     Similarly, carbon black morphology region  271  in  FIG. 27  includes carbon blacks currently in commercial use for truck and bus (T/B) tire tread applications. Arrow  272  indicates the direction in which region  271  can be advantageously extended in accordance with the present invention. Performance characteristics, such as wear resistance, are understood to improve generally in the direction of trend arrow  272  subject, however, in the past, to offsetting degradation of these and other characteristics due to reduced molecular weight of the rubber and/or poorer macro-dispersion resulting from use of such higher surface area carbon blacks. Elastomer composites of the present invention can employ such higher surface area carbon blacks indicated by trend arrow  272  to achieve improved T/B tread materials, in view of their excellent macro-dispersion and MW sol . 
     Similarly, carbon black morphology regions  281  and  283  in  FIG. 28  show carbon blacks currently in commercial use for tread base and passenger car (PC) tire tread, respectively. Trend arrows  282  and  284  indicate the direction in which region  281  and  283 , respectively, can be advantageously extended in accordance with the present invention. Performance characteristics such as heat build-up (HBU) and rolling resistance are understood to improve for tread base in the direction of trend arrow  282  subject, however, in the past, to offsetting degradation of these and other characteristics due to reduced molecular weight of the rubber and/or poorer macro-dispersion resulting from use of such higher surface area, lower structure carbon blacks. Likewise, performance characteristics such as rolling resistance are understood to improve for PC tread in the direction of trend arrow  284  subject, however, in the past, to offsetting degradation of these and other characteristics due to reduced molecular weight of the rubber and/or poorer macro-dispersion resulting from use of such higher surface area, lower structure carbon blacks. Elastomer composites of the present invention can employ higher surface area, lower structure carbon blacks indicated by arrows  282  and  284  to achieve improved tread base and PC tread, respectively, in view of the excellent macro-dispersion and the optional preservation of high molecular weight in such elastomer composites. 
     Similarly, carbon black morphology regions  291 ,  293  and  294  in  FIG. 29  show carbon blacks currently in commercial use for sidewall, apex and steel belt tire applications, respectively. Trend arrows  292  and  295  indicate the direction in which region  291  and  294 , respectively, can be advantageously extended in accordance with the present invention. Performance characteristics such as heat build-up (HBU) and fatigue life are understood to improve for sidewall in the direction of trend arrow  292  subject, however, in the past, the offsetting degradation of these and other characteristics due to reduced molecular weight of the rubber and/or poorer macro-dispersion resulting from use of such lower structure carbon blacks. Likewise, performance characteristics such as heat buildup, processing and wire adhesion are understood to improve for steel belt elastomeric materials in the direction of trend arrow  295  subject, however, in the past, to offsetting degradation of these and other characteristics due to reduced molecular weight of the rubber and/or poorer macro-dispersion resulting from use of such higher surface area, lower structure carbon blacks. Elastomer composites of the present invention can employ higher surface area and/or lower structure carbon blacks as indicated by arrows  292  and  295  to achieve improved sidewall and steel belt rubber materials, respectively, in view of the excellent macro-dispersion and the optional preservation of high molecular weight in such elastomer composites. 
     Additional Examples 
     Preferred Embodiment and Control Samples Comprising Other Fillers 
     Additional samples of elastomer composites in accordance with certain preferred embodiments of the present invention, and corresponding control samples, were prepared. A first group of these employed a multiphase aggregate filler of the type referred to above as a silicon-treated carbon black. 
     Specifically, invention samples nos. 33-34 employed ECOBLACK® silicon-treated carbon black commercially available from Cabot Corporation (Billerica, Mass.). Such ECOBLACK® filler has morphological properties, i.e., structure and surface area, similar to that of carbon black N234. Sample no. 33 employed 45 phr ECOBLACK® filler and no extender oil. Sample no. 34 employed 68 phr ECOBLACK® filler and no extender oil. Typical filler and extender oil usage for various product applications are shown in Table 37, for elastomer composites of the invention comprising natural rubber and a blend of carbon black and silica filler. It should be understood that the use of silica filler in the compositions shown in Table 37 would typically replace a like amount of the carbon black filler. 
     
       
         
           
               
             
               
                 TABLE 37 
               
             
            
               
                   
               
               
                 Typical NR Formulations for Tire Applications 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                 Carbon 
                   
                   
               
               
                   
                   
                 Black 
                 Oil 
                 Silica 
               
               
                 Application 
                 Carbon Black Type 
                 Loading 
                 Loading 
                 Loading 
               
               
                   
               
               
                 Truck/Bus 
                 N110, N115, N121, 
                 40-60 phr 
                 0-20 phr 
                 0-10 phr 
               
               
                 Tread 
                 N134, N220, N299 
               
               
                 OTR Tread 
                 N110, N115, N220, 
                 45-55 phr 
                 5-10 phr 
                 5-20 phr 
               
               
                   
                 N231 
               
               
                 Steel Belt 
                 N326 
                 50-75 phr 
                  0-5 phr 
                 0-20 phr 
               
               
                 Truck/Bus 
                 N330, N550 
                 40-60 phr 
                 0-20 phr 
               
               
                 Tread Base 
               
               
                 Carcass Ply 
                 N326, N330, N550 
                 40-60 phr 
                 5-30 phr 
               
               
                 Sidewall 
                 N330, N351, N550 
                 30-60 phr 
                 5-30 phr 
               
               
                 Apex 
                 N326, N330, N351 
                 50-90 phr 
                 0-20 phr 
               
               
                 LRR PC Tread 
                 N234, N299, N339, 
                 40-60 phr 
                 0-30 phr 
               
               
                   
                 N343, N347, N351 
               
               
                   
               
            
           
         
       
     
     A second group of samples employed a blend or mixture of silica and carbon black. In embodiments of the present invention employing a blend of carbon black and silica fillers, it is generally preferred that they be used in weight ratio of at least about 60:40. That is, the carbon black preferably comprises at least about 60 weight percent of the filler to achieve good coagulation of the elastomer and to reduce or eliminate reagglomeration of the silica in the masterbatch. In particular, in examples nos. 35-38, as shown in Table 40, carbon black is used together with particulate SiO 2  filler HiSil® 233 available from PPG Industries (Pittsburgh, Pa., USA), having surface area BET of 150 m 2 /g, surface area DBPA of 190 mils/100 g, pH of 7 and a primary particulate size of 19 nanometers. 
     All of the invention samples, i.e., additional invention samples nos. 33-38, were prepared in accordance with the procedures and apparatus used for invention samples 1-32, as described above. Process and apparatus details for each of invention samples nos. 33-38 is given in Table 38, below. The field latex or concentrate employed in samples nos. 33-38, as the case may be, is the same as described above with reference to Table 24. It will be appreciated that the data in Table 38 parallels that provided in Table 25, above, for invention samples nos. 1-32. The carbon black filler “CRX2000” listed in Table 38 is the ECOBLACK® silicon-treated carbon black described above. 
     
       
         
           
               
             
               
                 TABLE 38 
               
               
                   
               
               
                 Invention Sample Production Details 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Cabot Elastomer Composite 
                 Slurry Nozzle Tip 
                 CB Slurry 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Invention 
                   
                 Carbon Black 
                 HiSil 233 
                 Oil loading 
                 Dia. 
                 Land length 
                 CB conc. 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Sample No. 
                 Latex type 
                 Type 
                 Loading (phr) 
                 Loading (phr) 
                 (phr) 
                 (in) 
                 (in) 
                 (% wt) 
               
               
                   
               
               
                 33 
                 field latex 
                 CRX2000 
                 46 
                 0 
                 0 
                 0.020 
                 0.5 
                 14.5 
               
               
                 34 
                 field latex 
                 CRX2000 
                 58 
                 0 
                 0 
                 0.020 
                 0.5 
                 14.5 
               
               
                 35 
                 field latex 
                 N220 
                 43 
                 10 
                 5 
                 0.025 
                 0.5 
                 13.9 
               
               
                 36 
                 field latex 
                 N234 
                 41 
                 9 
                 0 
                 0.020 
                 0.5 
                 13.5 
               
               
                 37 
                 field latex 
                 N234 
                 31 
                 20 
                 0 
                 0.020 
                 0.5 
                 14.0 
               
               
                 38 
                 latex  
                 STERLING 6740 
                 29 
                 20 
                 0 
                 0.020 
                 0.5 
                 15.5 
               
               
                   
                 concentrate 
               
               
                   
               
            
           
           
               
               
            
               
                   
                 Coagulum Zone 
               
            
           
           
               
               
               
               
               
            
               
                 Invention 
                 1st portion 
                 2nd portion 
                 3rd portion 
                 4th portion 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Sample No. 
                 Dia. (in) 
                 Length (in) 
                 Dia. (in) 
                 Length (in) 
                 Dia. (in) 
                 Length (in) 
                 Dia. (in) 
                 Length (in) 
               
               
                   
               
               
                 33 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                 34 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                 35 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                 36 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                 37 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                 38 
                 0.19 
                 3.0 
                 0.27 
                 1.6 
                 0.38 
                 2.3 
                 0.53 
                 3.2 
               
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Mixing Zone 
                 MicroFluidizer 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Invention 
                 Slurry flow rate 
                 Slurry velocity 
                 Antioxidant 
                 Latex flow rate 
                 Latex velocity 
                 Inlet pressure 
                 Outlet pressure 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Sample No. 
                 (lb/min) 
                 (ft/sec) 
                 TNPP (phr) 
                 Santoflex(phr) 
                 (lbs/min) 
                 (ft/sec) 
                 (psi) 
                 (psi) 
               
               
                   
               
               
                 33 
                 6.2 
                 710 
                 0.3 
                 0.4 
                 Field 
                 7.4 
                 10.7 
                 17000 
               
               
                 34 
                 6.2 
                 710 
                 0.3 
                 0.4 
                 Field 
                 5.8 
                 8.3 
                 17000 
               
               
                 35 
                 5.2 
                 380 
                 0.3 
                 0.4 
                 Field 
                 4.9 
                 7.1 
                 14500 
               
               
                 36 
                 5.0 
                 576 
                 0.3 
                 0.4 
                 Field 
                 4.3 
                 6.2 
                 10000 
               
               
                 37 
                 4.8 
                 550 
                 0.3 
                 0.4 
                 Field 
                 4.1 
                 5.9 
                 9500 
               
               
                 38 
                 5.1 
                 580 
                 0.3 
                 0.4 
                 Conc 
                 2.2 
                 3.2 
                 9000 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Slurry Nozzle 
                 Dewatering 
                 Drying and Cooling 
                   
                 Production 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Invention 
                 Tip Pressure 
                 Initial crumb 
                 Final crumb 
                 Product 
                 Product 
                 Mixer 
                 Rate 
                 Invention 
               
               
                 Sample No. 
                 (psi) 
                 moisture (%) 
                 moisture (%) 
                 temp. (° F.) 
                 moisture (%) 
                 Type 
                 (lb/hr) 
                 Sample No. 
               
               
                   
               
               
                 33 
                 — 
                 77.5 
                 &gt;8.0 
                 435 
                 0.2 
                 T-block 
                 66 
                 33 
               
               
                 34 
                 — 
                 78.0 
                 1.6 
                 470 
                 0.3 
                 T-block 
                 52 
                 34 
               
               
                 35 
                 1650 
                 77.9 
                 &gt;4.0 
                 360 
                 0.4 
                 T-block 
                 54 
                 35 
               
               
                 36 
                 3000 
                 79.2 
                 1.0 
                 475 
                 0.5 
                 T-block 
                 39 
                 36 
               
               
                 37 
                 2930 
                 78.9 
                 12.3 
                 435 
                 0.4 
                 T-block 
                 34 
                 37 
               
               
                 38 
                 2600 
                 69.7 
                 4.2 
                 455 
                 0.2 
                 T-block 
                 48 
                 38 
               
               
                   
               
            
           
         
       
     
     The control samples 451-498 were prepared in accordance with the procedures and apparatus described above for control samples nos. 1-450. The processing code (see Table 13 above), filler loading, rubber, MW sol  and macro-dispersion for masterbatches 451-466 are set forth below in Table 39. The processing code, filler loading, rubber, MW sol  and macro-dispersion values of the invention samples nos. 33-38 (along with the filler and oil loadings for convenient reference) are shown in Table 40. It will be seen from Table 39 that control samples 451-466 correspond in composition to invention samples nos. 33 and 34. Similarly, control samples nos. 467-498 correspond to invention samples nos. 35-38. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 39 
               
             
            
               
                   
                   
               
               
                   
                 CRX 2000/44/0 
                 CRX 2000/58/0 
               
               
                   
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M2 
                   
                 909 
                   
                   
                 909 
                   
               
               
                 M3 
                   
                 590 
                   
                   
                 590 
               
               
                 M2D1 
                 451 
                 461 
                 3.48 
                 459 
                 333 
                 8.61 
               
               
                 M2D2 
                 452 
                 474 
                 3.68 
                 460 
                 392 
                 5.71 
               
               
                 M2D3 
                 453 
                 489 
                 7.17 
                 461 
                 388 
                 9.48 
               
               
                 M2D4 
                 454 
                 515 
                 6.28 
                 462 
                 394 
                 8.05 
               
               
                 M3D1 
                 455 
                 393 
                 2.89 
                 463 
                 280 
                 2.23 
               
               
                 M3D2 
                 456 
                 422 
                 2.87 
                 464 
                 298 
                 2.13 
               
               
                 M3D3 
                 457 
                 435 
                 4.15 
                 465 
                 350 
                 4.05 
               
               
                 M3D4 
                 458 
                 449 
                 3.23 
                 466 
                 379 
                 7.22 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 40 
               
             
            
               
                   
               
               
                 Sol Molecular Weight and Undispersed Area of Invention Samples 
               
            
           
           
               
               
               
               
            
               
                 Invention 
                   
                   
                   
               
               
                 Sample No. 
                 CB/Loading/Oil 
                 Mw sol  (K) 
                 D (%) 
               
               
                   
               
               
                 33 
                 CRX 2000/44/0 
                 380 
                 0.18 
               
               
                 34 
                 CRX 2000/58/0 
                 448 
                 0.10 
               
               
                 35 
                 N220/Hilsil 233/43/10/5 
                 500 
                 0.14 
               
               
                 36 
                 N234/Hilsil 233/40/10/0 
                 490 
                 0.36 
               
               
                 37 
                 N234/Hilsil 233/30/20/0 
                 399 
                 0.23 
               
               
                 38 
                 STERLING 6740/Hilsil 233/30/20/0 
                 354 
                 0.39 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 41 
               
               
                   
               
               
                   
                 Sample 
                 Mw sol   
                   
                 Sample 
                 Mw sol   
                   
               
               
                 Code 
                 No. 
                 (K) 
                 D (%) 
                 No. 
                 (K) 
                 D (%) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 N220/Hilsil 233/43/10/5 
                 N234/Hilsil 233/40/10/0 
               
               
                   
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M2 
                   
                 803 
                   
                   
                 909 
                   
               
               
                 M3 
                   
                 601 
                   
                   
                 590 
               
               
                 M2D1 
                 467 
                 493 
                 1.51 
                 475 
                 443 
                 8.74 
               
               
                 M2D2 
                 468 
                 537 
                 2.61 
                 476 
                 517 
                 10.9 
               
               
                 M2D3 
                 469 
                 523 
                 2.82 
                 477 
                 569 
                 12.5 
               
               
                 M2D4 
                 470 
                 615 
                 2.95 
                 478 
                 592 
                 8.25 
               
               
                 M3D1 
                 471 
                 417 
                 0.95 
                 479 
                 358 
                 6.65 
               
               
                 M3D2 
                 472 
                 438 
                 1.40 
                 480 
                 420 
                 13.8 
               
               
                 M3D3 
                 473 
                 433 
                 2.15 
                 481 
                 516 
                 13.9 
               
               
                 M3D4 
                 474 
                 485 
                 2.22 
                 482 
                 447 
                 7.25 
               
            
           
           
               
               
               
            
               
                   
                   
                 STERLING 
               
               
                   
                 N234/Hilsil 233/30/20/0 
                 6740/Hilsil 233/30/20/0 
               
               
                   
                 RSS1 
                 RSS1 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 M2 
                   
                 909 
                   
                   
                 909 
                   
               
               
                 M3 
                   
                 590 
                   
                   
                 590 
               
               
                 M2D1 
                 483 
                 394 
                 4.37 
                 491 
                 430 
                 3.77 
               
               
                 M2D2 
                 484 
                 507 
                 5.66 
                 492 
                 488 
                 4.39 
               
               
                 M2D3 
                 485 
                 526 
                 4.7 
                 493 
                 517 
                 5.37 
               
               
                 M2D4 
                 486 
                 568 
                 5.94 
                 494 
                 563 
                 4.66 
               
               
                 M3D1 
                 487 
                 377 
                 8.39 
                 495 
                 375 
                 3.5 
               
               
                 M3D2 
                 488 
                 363 
                 4.49 
                 496 
                 380 
                 2.73 
               
               
                 M3D3 
                 489 
                 376 
                 5.07 
                 497 
                 419 
                 2.72 
               
               
                 M3D4 
                 490 
                 432 
                 5.26 
                 498 
                 448 
                 3.29 
               
               
                   
               
            
           
         
       
     
     The excellent carbon black dispersion in the masterbatches of invention samples 33-38 is demonstrated by comparison of the macro-dispersion quality and MW sol  values shown in Tables 39-41. The invention samples nos. 33-34 made with ECOBLACK® silicon-treated carbon black, and the corresponding control samples are compared in the semi-log plot of  FIG. 30 . Excellent carbon black dispersion is seen in  FIG. 30  for the invention samples, representing preferred embodiments of elastomer composites in accordance with the present disclosure. The invention samples advantageously are below line  301  in  FIG. 30 , whereas all of the control samples have poorer dispersion, being above line  301 . In fact, the preferred embodiments shown in  FIG. 30  fall below a D(%) value of 0.2% even at an MW sol  value advantageously exceeding 0.4×10 6 . The data shown in  FIG. 30  clearly reveals that the macro-dispersion quality of the novel elastomer composites, disclosed here, comprising silicon-treated carbon black is significantly superior to that achievable using comparable ingredients in prior dry mixing methods. The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 30  are described by the following equations:
 
 D (%)&lt;1.0%  (25)
 
when MW sol  is less than 0.4×10 6 ; and
 
log( D )&lt;log(1.0)+2.0×[MW sol −(0.4×10 6 )]×10 −6   (26)
 
when 0.4×10 6 &lt;MW sol &lt;1.1×10 6  
 
It will be recognized that D(%) is the percent undispersed area measured for defects greater than 10 microns and 1% is the threshold macro-dispersion quality for the masterbatches in accordance with these preferred embodiments of the present invention. That is, none of the dry masticated masterbatches achieved macro-dispersion quality of 1.0% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.4×10 6 . The preferred embodiments shown in  FIG. 30  fall well below the threshold. It can be seen that the elastomer composites of the invention comprising silicon-treated carbon black provide heretofore unachieved balance between macro-dispersion quality and MW sol .
 
     Invention samples nos. 35-38 comprising carbon black blended with silica filler and corresponding control samples are compared in the semi-log plot of  FIG. 31 . Specifically,  FIG. 31  shows the macro-dispersion values and MW sol  values of the invention samples nos. 35-38 and corresponding control samples nos. 467-498. Excellent carbon black dispersion is seen in  FIG. 31  for the invention samples, representing preferred embodiment of elastomer composites in accordance with the present disclosure. The invention samples advantageously are below line  311  in  FIG. 31 , whereas all of the control samples have poorer dispersion, being above line  311 . In fact, all of the preferred embodiments shown in  FIG. 31  fall below a D(%) value of 0.4%. The data shown in  FIG. 31  clearly reveals that the macro-dispersion quality of the novel elastomer composites, disclosed here, comprising carbon black/silica blends over a range of MW sol  values, is significantly superior to that achievable using comparable ingredients in prior dry mastication mixing methods. The macro-dispersion values for the elastomer composites of the invention shown in  FIG. 31  are described by the following equations:
 
 D (%)&lt;0.8%  (27)
 
when MW sol  is less than 0.5×10 6 ; and
 
log( D )&lt;log(0.8)+2.2×[MW sol −(0.5×10 6 )]×10 −6   (28)
 
when 0.5×10 6 &lt;MW sol &lt;1.1×10 6  
 
It will be recognized that D(%) is the percent undispersed area measured for defects greater than 10 microns and 0.8% is the threshold macro-dispersion quality for masterbatches in accordance with these preferred embodiments of the present invention. That is, none of the dry masticated masterbatches achieved macro-dispersion quality of 0.8% or better at any MW sol , even after dry mixing sufficiently to degrade MW sol  below 0.4×10 6 . The preferred embodiments shown in  FIG. 31  fall well below the threshold macro-dispersion value of 0.8%, and even below 0.4%. It can be seen that the elastomer composites of the invention comprising carbon black/silica blend filler provide heretofore unachieved balance between macro-dispersion quality and MW sol .
 
     In view of the foregoing disclosure, it will be apparent to those skilled in the art that various additions, modifications, etc. can be made without departing from the true scope and spirit of the invention. All such additions and modifications are intended to be covered by the following claims.