RESINOUS COMPOSITIONS HAVING REDUCED TENDENCY TO IGNITE AND IMPROVED PROCESSABILITY

Abstract: Resinous compositions having a reduced tendency to ignite when an external heat source is applied, and improved processability in terms of high-shear flow, such composition comprising a rubber reinforced styrene polymer, a styrene-butadiene block copolymer (optional for enhancing flow), an olefin polymer, a halide-containing ignition retardant and an antimony compound.

Description: RESINOUS COMPOSITIONS HAVING REDUCED TENDENCY TO IGNITE AND IMPROVED PROCESSABILITY Background of the Invention It is known that resinous compositions having styrene polymerized therein, having a reduced tendency to ignite when an external heat source is applied thereto, are prepared by adding thereto an organic halide together with an inorganic ignition retardant, such as antimony trioxide. However, the use of these ignition retardants, especially those of particulate or crystalline form, such as antimony trioxide, which do not melt and which disperse at tempera- tures at which styrene resins are usually worked, can often remarkably lower the toughness of the polymers and detract from other desirable properties peculiar to the resinous compositions having styrene polymerized therein. Further, while organic halides are quite effective in providing styrene resins with a reduced tendency to ignite when an external heat source is applied, they generally do not reduce the tendency of polymers to drip while burning and, in order to cause the polymers to achieve a rating within the range of V-l to V-0, as provided under Subject 94, Underwriters Laboratories Tests For Flammability of Plastic Materials (hereinafter referred to as "UL-94"), a large amount of halide-containing compounds must be added. While the addition of an antimony compound with the organic halide obviates this problem to a degree, the polymers will stil tend to drip as the thickness of the polymer moldings is reduced, thereby making it difficult to qualify thin specimens for a rating in the range of V-l to V-O under UL-94. In other words, as the thickness of the sample to tested is increased, it is easier to attain a UL-94 ratin of V-0. The usual test sample has a thickness of at leas 60 mils. We have now found that V-O ratings may be achie with sample thicknesses of 50 and 40 mils. The tests employed with the materials of this invention are not intended to reflect hazards present by these, or any other, materials under actual fire conditio It is known that the processability and flow behavior of polymeric materials at both high and low shear rates can be altered by the addition of plasticizers and lubricating agents such as oils, waxes, fatty acids such a stearic acid, fatty acid derivatives such as butyl steara etc. It is also known that the addition of such additives while improving the melt flow behavior also detracts from such desirable polymer properties as tensile strength, tensile modulus, and heat distortion, thus creating a situation where a compromise of processability and physica properties must be accepted. It is known that the addition of styrene-butadie block copolymers (linear or radial) to styrenic polymer compositions will often improve the impact* resistance and the practical toughness of polymer compositions. The bloc O copolymers do not, however, significantly improve processability (high-shear flow). Therefore, plasticizers or lubricating agents may be added to improve processability. As stated above, the addition of these modifiers detracts from desirable polymer properties such as tensile strength and heat distortion, thereby leading to a compromise between processability and physical properties. It is known from Zeitler et al. (US Patent No. 4,020,025) that foams of mixtures of polyolefins and styrene polymers are produced by mixing the polymers with low-boiling expanding agents in the presence of a hydrogenated styrene-butadiene block polymer or a graft polymer of styrene on a polyolefin at temperatures above the softening point of the polymer mixture and under a pressure which prevents foaming of the mixture, followed by extrusion of the foamable mixture into a zone of lower pressure where the mixture is foamed. It is known from Bronstert et al. (US Patent No. 4,031,166) that an impact-resistant thermoplastic molding material for forming rigid products results from a combination of a high molecular weight homopolymer or copolymer of styrene, and a mixture comprised of an al- pha-olefin polymer and a block copolymer of the configuration A-B, A-B-B, or A-B-A wherein A denotes a vinyl aromatic such as styrene and B denotes a diene hydrocarbon such as butadiene. It is known from Yoshida et al. (Serial No. 959,271; filed 9 November 1978) that a resin composition having high impact resistance, improved release property and reduced flammability is obtained by mixing a polymer containing a major amount of a monovinyl aromatic monomer, a block copolymer consisting essentially of styrene and A butadiene, an amorphous alpha-olefin polymer, a halide- -containing flame-retardant compound, and an antimony compound. It is known from Barkhuff, Jr. et al. (US Patent 4,069,288) that fire-retardant polystyrene compositions, which comprise a polystyrene component, a metal oxide (whi functions as a synergist in improving the efficiency of th halogen additive) and a fire-retardant halogen additive ar obtained by first mixing the metal oxide with a minor amou of the polystyrene component, subjecting the mixture to hi intensity mixing, comminuting the mixture, blending the co minuted mixture with the other ingredients of the composit compounding said blend, and comminuting said blend. The various methods heretofore employed to form styrene-based resinous compounds concentrate, if at all, upon obtaining a flammability rating under UL-94 of V-l to V-O with film specimen thicknesses of at least 60 mils. An object of the present invention is to provide resinous compositions which have a reduced tendency to ignite when an external heat source is applied. A further object is to provide resinous compositions which have improved processability while maintaining desirable polyme qualities such as tensile strength and resistance to distortion at higher temperatures. Other aspects, objects, and the several advantag of the invention will be apparent to those skilled in the art from the description and appended claims. Summary of the Invention We have now found that resinous compositions having the said properties are obtained from physical mixtures of (A) from about 90.2 to about 65.3 parts by weight of rubber-reinforced styrene polymer; (B) from about 0 to about 10 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n equals 1 to 3, and where A represents a styrene polymer block and B represents a butadiene polymer block, said block copolymer having a weight average molecular weight within the molecular weight range of about 50,000 -to about 500,000; (C) from about 0.2 to about 4 parts by weight of an olefin polymer wherein the copolymers such as ethylene-propylene have a specific gravity of from about 0.80 to about 0.98 and a Mooney Viscosity (ML-8 at 212° Farenheit or 100° Centigrade) of from about 25 to about 50 and the homopolymers such as polyethylene have a density of from about 0.80 to about 0.98 and a Melt Index determined in accordance with ASTM-D-1238 of from about 5 to about 50, having polymerized therein from about 0 to about 100 percent by weight of ethylene and from about 100 to about 0 percent by weight of an ethylenically unsaturated monomer poly¬ merized therewith; (D) from about 7 to about 20 parts by weight of a halide-containing ignition retardant; and (E) from about 2 to about 6 parts by weight of a metal oxide synergist which functions as a synergist in improving the efficiency of the halide-containing ignition retardant. The accompanying Figures 1 and 2 represent, respectively, a two-dimensional display of UL-94 V-O ratings for various combinations of the block copolymer and alpha-olefin polymer components of the resinous composition and a representation of a three-dimensional figure wherein the Z-axis is added to project the values of Figure 1 onto varying test sample thicknesses. The Z-axis represents tes sample thickness. Figure 3 is a two-dimensional plot of Shear Rheology (Instron Drive) information at 160°C for various combinations, in accordance with the invention, of block copolymers and/or olefin polymers of crosshead speed (inches/minute) versus pounds of force. Figure 4 is a two-dimensional plot of Shear Rheology (Instron Drive) information at 160°C for various combinations, in accordanc with the invention, of block copolymers and/or olefin polymers of shear rate (seconds- ) versus apparent viscosit (poise). Figure 5 is a two-dimensional plot of Shear Rheology (Ametek Drive) information at 160°C for various combinations, in accordance with the invention, of block copolymers and olefin polymers of shear rate (seconds " ) versus apparent viscosity (poise). Figure 6 is a two-dimensional plot of Shear Rheology (Instron Drive) information at 160°C for various combinations, in accordanc with the invention, of block copolymers and olefin polymers of shear rate (seconds " ) versus apparent viscosity (poise). The Component (A) preferably comprises impact- resistant interpolymers or graft copolymers of monovinyl aromatic compounds having the vinyl radical directly at¬ tached to a carbon atom of the aromatic nucleus, e.g., styrene, with a minor proportion of a natural or synthetic rubber, e.g., butadiene. The rubber is preferably dispersed in the form of a plurality of particles, a majority of which have diameters within the range of from about 0.2 to 5 microns, and, within said plurality of particles, at least a majority of the particles have monovinyl aromatic polymer occluded therein. More preferably, Component (A) comprises Oϊ.IPI from about 65.3 to about 90.2 parts by weight of impact resistant interpolymers or graft copolymers of a styrene matrix with a minor proportion of butadiene rubber dispersed in the form of a plurality of particles, a majority of which have diameters within the range of from about 0.2 to about 5 microns, and within said plurality of particles, at least a majority of the particles have styrene polymer occluded therein, wherein the molecular weight of the styrene matrix is from about 100,000 to about 500,000. Most preferably, Component (A) comprises from about 65.3 to about 90.2 parts by weight of interpolymers or graft copolymers of a styrene matrix with about 7.2 weight percent polybutadiene rubber dispersed in the form of a plurality of particles, a majority of the polybutadiene rubber particles have diameters within the range of from about 0.2 to about 5 microns, and within said plurality of polybutadiene rubber particles, at least a majority have styrene polymer occluded therein, wherein the molecular weight of the styrene matrix is about 190,000. Impact resistant styrene polymers are well-known items of commerce. Suitable methods of making the preferred interpolymers or graft copolymers can be found in Amos et al. (US Patent No. 2,694,692), Ruffing et al. (US Patent No. 3,243,481) and McCurdy et al. (US Patent No. 3,945,976), the teachings of which are herein incorporated by reference thereto. Another suitable method of producing Component (A) can be found in Ostromislenεky (US Patent No. 1,613,673), the disclosure of which is herein incorporated by reference. The Component (B) is comprised preferably of block copolymers of the configuration A-B-A wherein A represents polymer blocks of an alkenyl-substituted aromatic hydro¬ carbon, e.g., styrene, and B represents polymer blocks of conjugated dienes, e.g., butadiene, said block copolymer containing from about 10 to about 50 percent by weight of A and from about 90 to about 50 percent by weight of B. More preferably, the Component (B) is comprised of block copolymers of the configuration A(BA) , where n equals 1 to 3, A represents styrene, B represents butadiene, and the percent by weight ratio of styrene to butadiene of from about 10:90 to about 50:50, which have a weight average molecular weight, as determined by gel permeation chromatography, within the molecular weight range of from about 50,000 to about 500,000 and in an amount within the range of from about 0.8 to about 10 parts by weight when the object is to produce resinous compositions which have a reduced tendency to ignite when an external heat source is applied and from about 0 to about 10 parts by weight when the object is to provide physical blends which have improve processability while maintaining desirable polymer properties such as tensile strength and resistance to distortion at higher temperatures. Most preferably, the Component (B) is comprised of styrene-butadiene block copolymers of the configuration A(BA) , where A and B respectively are polymer blocks of styrene and butadiene and n equals 1 to 3 and the percent by weight ratio of styrene to butadiene is from about 10:90 to about 50:50, which have a weight average molecular weight, as determined by gel permeation chromatography, within the molecular weight range of from about 60,000 to about 300,000, in an amount within the range of from about 1.8 to about 4.3 parts by weight when the object is to produce resinous compositions which have a reduced tendency to ignite when an external heat source is applied and from about 0 to about 4.3 parts by weight when the object is to provide physical blends which have improved processability while maintaining desirable polymer properties as tensile strength and resistance to distortion at higher temperatures. Beneficially and preferably, the block copolymer contains from about 10 to about 50 percent by weight styrene and from about 90 to about 50 percent by weight butadiene. Suitable methods of making block copolymers can be found in Holden et al. (US Patent No. 3,231,635) and Zellinεki (US Patent Nos. 3,251,905 and 3,287,333), the teachings of which are herein incorporated by reference. The Component (C) preferably comprises from about 0.2 to about 4 parts by weight of an olefin polymer/copolymer wherein the copolymers such as ethylene-propylene have a specific gravity of from about 0.80 to about 0.98 and a Mooney Viscosity (ML-8 at 212° Farenheit or 100° Centigrade) of about 25 to 50 and the homopolymers such as polyethylene have a density of from about 0.80 to about 0.98 and a Melt Index determined in accordance with American Society for Testing Materials (hereinafter referred to as ASTM) D-1238 of from about 5 to about 50. More preferably, the Component (C) comprises from about 0.2 to about 4 parts by weight of an alpha-olefin polymer/copolymer having polymerized therein from about 0 to about 100 percent by weight of ethylene and from about 10& to about 0 percent by weight of a copolymerizable ethylenically unsaturated monomer, wherein the copolymers such as ethylene-propylene have a specific gravity of from about 0.80 to about 0.98 and a Mooney Viscosity (ML-8 at 212° Farenheit or 100° Centigrade) of from about 25 to about 50 and the homopolymers such as polyethylene have a density of from about 0.80 to about 0.98 and a Melt Index determined in accordance with American Society for Testing Materials (hereinafter referred to as ASTM) D-1238 of from about 5 to about 50. Still more OMPI _ \ /., IPO .v preferably, the Component (C) comprises from about 0.2 to about 4 parts by weight of an amorphous alpha-olefin polyme copolymer having polymerized therein from about 0 to about 100 percent by weight of ethylene and from about 100 to about 0 percent by weight of a copolymerizable ethylenicall unsaturated monomer such as propylene or acrylic acid, wherein the copolymers such as ethylene-propylene have a specific gravity of from about 0.80 to about 0.98 and a Moo Viscosity (ML-8 at 212° Farenheit or 100° Centigrade) of from about 25 to about 50 and the homopolymers such as poly ethylene have a density of from about 0.80 to about 0.98 an a Melt Index determined in accordance with ASTM-D-1238 of from about 5 to about 50. Most preferably, the Component (C) comprises from about 0.3 to about 1.3 parts by weight of an amorphous alpha-olefin polymer/copolymer having poly¬ merized therein from about 0 to about 100 percent by weight of ethylene and from about 100 to about 0 percent by weight of propylene wherein the copolymers of ethylene-propylene have a specific gravity of from about 0.84 to about 0.95 and a Mooney Viscosity (ML-8 at 212° Farenheit or 100° Centigrade) of from about 29 to about 44 and the homo¬ polymers of polypropylene and polyethylene have a density of from about 0.84 to about 0.95 and a Melt Index determine in accordance with ASTM-D-1238 of from about 7 to about 42. Suitable methods of making alpha-olefin polymers/copolymers can be found in Reding et al. (US Patent No. 3,197,449),- Schmid et al. (US Patent No. 3,300,457), Anspon et al. (US Patent No. 3,485,812), Thomson et al. (US Patent No. 3,520,861), and Shurts (US Patent No. 3,912,698), the disclosures of which are herein incorporated by reference. The Component (D) preferably comprises a halide- containing organic ignition retardant. More preferably, th O PI Component (D) comprises a halide-containing ignition retardant which is generally well-known in the art selected from the group represented by Formulae (I) to (VI). (I) ' or mixtures thereof. Still more preferably, the Component (D) comprises from about 7 to about 20 parts by weight of a bromine- containing ignition retardant selected from the group consisting of hexabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, l,2-bis(tribromophenoxy)- ethane, 1,2-bis(pentabromophenoxy)ethane, tetrabromo biεphenol-A, ethylene(N,N' )-bis-tetrabromophthalimide, tetrabromophthalic anhydride, and hexabromobenzene. Most preferably the Component (D) comprises from about 9 to about 15 parts by weight of decabromodiphenyl ether(decabromodiphen oxide). Suitable methods for incorporating the halogen- containing ignition retardant is set forth in Barkhuff, Jr. et al. (U.S. Patent No. 4,069,288), the disclosures of which are herein incorporated by reference. The Component (E) preferably comprises a metal oxide synergist, such as antimony trioxide, bismuth tri- O PI oxide, molybdenum trioxide, tin dioxide and tungsten trioxide, which functions as a synergist in improving the efficiency of the halogen-containing ignition retardant. More preferably, the Component (E) comprises from about 2 to about 6 parts by weight of antimony trioxide. Most preferably, the Component (E) comprises from about 2.5 to about 5 parts by weight of antimony trioxide. Methods of incorporating the antimony compound can be found in Bethea et al. (US Patent No. 3,988,296), the disclosure of which is herein incorporated by reference. The ingredients may be blended by any of the conventional melting and mixing apparatuses which will result in a generally uniform dispersion of all ingredients throughout the resulting product. Illustrative apparatuses include Banbury mixers, compounding rolls, single screw extruders, twin screw extruders, etc. The preferred apparatus is the twin screw extruder. The ingredients may either be combined in an apparatus such as a dry blender before being fed into the mixing and melting extruding apparatus or two or more of the ingredients may be pre-mixed and fed as a stream into the hot melt of the remaining ingredients. The preferred technique involves premixing a small amount of the impact resistant styrene polymer with the metal oxide (which has a synergistic effect in improving ' the efficiency of the halogen additive) and the halogen- containing additive, and feeding this as a separate stream from the remaining ingredients into a twin screw extruder. The following examples illustrate ways in which the principle of the invention has been applied but are not to be construed as limiting its scope. O PI Unless otherwise indicated, all parts and percentages are by weight. In addition, the following key is provided to simplify indentification of the various ingredients in a consistent manner throughout the examples COMPONENT COMPONENT EXPLANATION DESIGNATION A An amorphous a-olefin polymer of ethylene a propylene with a weight ratio of ethylene t propylene of 60 to 40 copolymerized therein a specific gravity of 0.86, and a Mooney Viscosity (ML-8 at 212°F (100°C)) of 36 whi is commeπcally available under the trade (R) ddeessiiggnnaattiioonn ooff EEPPCCAARR 330066 isold by B. F. Goodrich Chemical Company. B A low molecular weight styrene-buta- diene radial block copolymer with a weight ratio of butadiene to styrene of 60 to 40 copolymerized therein and a weight average molecular weight of about 130,000 which is commerically available under the trade designation SOLPRENE 414 sold by Phillips Chemical Company. C A high molecular weight styrene-buta- diene radial block copolymer with a weight ratio of butadiene to styrene of 70 to 30 copolymerized therein and a weight average molecular weight of about 300,000 which is commercially available under the trade ddeessiiggnnaattiioonn SSOOLLPP:RENE 411 sold by Phillips Chemical Company OMPI D A styrene-butadiene linear block copoly¬ mer with a weight ratio of butadiene to styrene of 72 to 28 copolymerized therein and a weight average molecular weight of about 66,000 which is commerically available under the trade designation KRATON 2103 sold by Shell Chemical Company. E An oil-extended styrene-butadiene linear block copolymer with a weight ratio of butadiene to styrene of 70 to 30 copoly¬ merized therein, a weight average molecular weight of about 92,000, and one part of oil for every two parts of the linear block copolymer, which is commercially available under the trade designation KRATON® 2104 sold by Shell Chemical Company. F A low density polyethylene, with a melt index determined in accordance with ASTM- -D-1238, Condition E, of 35, and a density of about .92, which is commercially available as Dow Polyethylene Resin 955 sold by The Dow Chemical Company. G A polymer of ethylene and acrylic acid with a weight ratio of ethylene to acrylic acid of 92 to 8 copolymerized therein, a density of about .93, and a Melt Index determined in accordance with ASTM-D-1238, Condition E, of 9, which is commercially available as Dow EAA Resin 459 sold by The Dow Chemical Company. OMPI H A low density polypropylene having a densit of about .90, with a flow rate determined i accordance with ASTM-D-1238, Condition L, o 12, which is commerically available under t ttrraaddee ddeessiiggnnaaltion PROFAX 6331 sold by Hercules, Inc. I A rubber-reinforced polystyrene con¬ taining about 7.2 weight percent polybutadiene rubber, said rubber being dispersed in the form of a plurality of particles, a majority of which have diamete within the range of from about 0.2 to about microns, and within said plurality of particles, at least a majority of the particles have styrene polymer occluded therein, wherein the molecular eight is about 190,000 and the percent gel is about 24%. J The rubber-reinforced polystyrene, specified at I above, in intimate admixture with about 11.5% decabromodiphenyl oxide an about 3.3% antimony trioxide, both weights being based upon the total weight of the mixture of ingredient I, decabromodiphenyl oxide, antimony trioxide and such other ingredients as may be added in each of the examples 1 to 55 which follow. EXAMPLES 1 to 26 Examples 1 to 26 were prepared for testing by me compounding the additives specified in Table 1 below into Component J on a two-roll mill with a roll temperature of about 340° Farenheit and then compression molding the resultant composition, of the additives and Component J, in accordance with ASTM-D-638-77, at a temperature of about 390° Farenheit under a pressure of about 25,000 pounds per square inch, into samples of the size specified by Underwriter's Laboratory Tests for Flammability of Plastic Materials (UL-94) of 1/2 inch by 6 inches. The sample thicknesses are set forth in Table 1. TABLE 1 Example UL-94 RATING AT INDICATED THICKNESS (MILS) No . % B %_h 60 50 40 30 1* 0 0 V-O V-2 V-2 2 1 0 V-O V-O V-2 3 3 0 V-O V-O V-O V-2 4 4 0 V-O V-O V-2 5* 5 0 V-O V-2 6* 7 0 V-O V-2 7* 0 1 V-O V-2 8* 0 3 V-O V-2 g* 0 5 V-O V-2 10* 0 7 V-O V-2 1 2 1 . 5 1.5 V-O V-O V-2 TABLE 1 (Continued) Example UL-94 RATING AT INDICATED THICKNESS (MILS) No. % B % A 60 50 40 30 14 3 1 V-O V-O V-2 15* 2 3. .5 V-O V-2 16* 3.5 3. .5 V-O V-2 17* 5 3. ,0 V-O V-2 18* 6.7 2. .4 V-O V-2 19* 7.53 1. .18 V-O V-2 20 2.14 .9 V-O V-O V-O V-2 21 2 0 V-O V-O V-2 22 3.65 1. ,83 V-O V-O V-2 23 4 1 V-O V-O V-O V-2 24 5 1 V-O V-O V-2 25 6 1 V-O V-O V-2 26 5 2 V-O V-O V-2 The data presented in Table 1 is graphically portrayed in Figure 1, a two-dimensional display which reflects the variations in amounts of A and B, and Figure a three-dimensional display which projects the UL-94, V-O ratings achieved by variations in amounts of A and B onto the Z-axis which represents sample thickness. The data in Table 1 was presented to demonstrate the effect of varying combinations of olefin polymers and block copolymers on the UL-94 ratings at a constant level ignition retardant additives. EXAMPLES 27 to 32 Examples 27-32 were prepared for testing by twic extruding the additives and Component J on a 0.8 inch twin screw extruder, manufactured by Welding Engineers, Inc., a a speed of about 200 revolutions per minute and a barrel temperature of about 400° Farenheit and then compression molding the resultant composition, of the additives and Component J, in accordance with ASTM-D-638-77, at a temperature of about 390° Farenheit under a pressure of ab 25,000 pounds per square inch, into samples of the size specified by Underwriter's Laboratory Tests for Flammabili of Plastic Materials (UL-94) of 1/2 inch by 6 inches. The sample thicknesses are set forth in Table 2. TABLE 2 Example % Block % Olefin UL-94 RATING at Indicated Thickness (Mils ) No. Copolymer Polymer 60 50 40 27 4% B 1% A V-O V-O V-O 28 4% C 1% A V-O V-O V-O 29 4% D 1% A V-O V-O V-O 30 4% B 1% F V-O V-O V-O 31 4% B 1% G V-O V-O V-O 32 4% B 1% H V-O V-O V-O The data in Table 2 was presented to demonstrate the equivalence of block copolymers in Examples 27 to 29 a of olefin polymers in Examples 30 to 32. EXAMPLES 33 to 41 Examples 33 to 41 were prepared for testing by melt compounding the additives (ignition retardants plus 3 percent B and 1 percent A) into the Component I, either by the two-roll mill process used for Examples 1 to 26 above (hereinafter referred to as Process R) or by the twin scre process used for Examples 27 to 32 above (hereinafter referred to as Process S). These processes are referred t by their letter designation in Table 3. Examples 33 to 41 contain varying levels of the preferred ignition-retardant additives, decabromodiphenyl oxide and antimony trioxide, as reflected in Table 3 below with a weight ratio of decabromodiphenyl oxide to antimony trioxide of about 3.5 to 1 in each example. _ O TABLE 3 Example Total Ignition Mixing UL-94 Rating at Indicated Thickness (Mils) No. Retardant % Process 80 70 60 50 40 30 33 16.2 S V-O V-O V-O V-2 34 15.6 S V-O V-O V-O V-2 35 15.2 S V-O V-O V-O V-2 36 14.8 R V-O V-O V-2 — 37 14.3 S V-O V-O V-2 — 38 13.6 S V-O V-O V-2 — 39 13.4 R V-O V-O V-2 40 13.2 R V-l V-2 V-2 41 13.0 R SB Note: The dashed line (—) indicates that no sample was evaluated. SB = Slow burning. 2 The data in Table 3 was presented to demonstrate the effect of varying levels of ignition retardants upon t UL-94 ratings of an otherwise unvarying melt compound. EXAMPLES 42 to 48 Examples 42 to 48 were prepared for testing by Process S (see Example 27). The tests used to evaluate certain physical properties are set forth in the following key: TEST DESIGNATION TEST EXPLANATION Izod Impact Izod Impact - measured in accordance with ASTM-D-256-78 in units of foot-pound per inch. Tensile Yield Tensile Yield - measured in accordance with ASTM-D-638-77 in units of pounds per square inch. Tensile Rupture Tensile Rupture - measured in accordance with ASTM-D-638-77 in units of pounds per square inch. Elongation Elongation Percent - measured in accordance with ASTM-D-638-77. Vicat Vicat Heat Distortion - measured in accordance with ASTM-D-1525-76 in units of degrees Farenheit. Melt Flow Rate Melt Flow Rate - measured in accordance with ASTM-D-1238-79, Condition G in units of grams/10 minutes. ( OM Ignition Rating Ignition-Retardant Rating - mea¬ sured in accordance with Underwriter's Laboratory Tests for Flammability of Plastic Material (UL-94) using samples 1/2 inch wide x 6 inches long x 80 mils thick. The results of the physical property evaluation are set forth in Table 4 below. OMPI , IPO _. TABLE 4 Example Izod Tensile Tensile Melt Flow Ign No. Ingredients Impact Yield Rupture Elongation Vicat Rate Ra 42 1.35 3170 2570 31 219.5 3.7 V 43 J + 1.5% A 1.32 3080 2280 23 219 3.6 V 44 J + 2% A 1.36 3110 2410 32 219 3.7 V 45 J + 3% E 1.60 2720 2460 49 214 4.4 V 46 J + 3% C 1.58 3200 2400 39 220 2.0 V 47 J + 3% C + 1.78 2890 2260 22 219 2.4 V 1.5% A 48 J + 4% B + 1.75 3150 2330 27 219.5 4.0 V A 1.5% A The data in Table 4 was presented to demonstrate that the preferred additives do not substantially detract from desirable polymer properties such as tensile yield strength and heat distortion. The Rheology (Instron Drive) data for Examples 42 to 48 was determined using an Instron Rheometer with a melt temperature of 160° Centigrade, a die diameter of 0.05 inch, and a die length of 1.005 inches and an Instron Model TTC drive unit produced by Instron Engineering Corporation. The data obtained is set forth in Table 5. OMPI Λ WIPO TABLE 5 RHEOLOGY (INSTRON DRIVE) AT 160°C Example No. Ingredients Pounds of Force 42 J 350 500 660 900 1390 1960 3150 8300 — — 43 J + 1.5% A 380 500 650 870 1320 1860 2930 6300 4700 4600 44 J + 2% A 330 450 610 825 1280 1790 2800 6500 5000 4800 1 45 J + 3% E 360 490 630 840 1210 1600 2150 4350 — — 46 J + 3% C 370 535 720 990 1540 2130 3980 8400 — — 47 J + 3% C + 370 520 720 980 1600 2500 4200 5200 5400 5400 1.5% A 48 J + 4% C + 375 520 660 860 1270 1760 2600 4800 5300 4300 1.5% A Crosshead Speed .02 .05 .1 .2 .5 1.0 2.0 5.0 10 20 (Inches/Minute) The data in Table 5 was presented to demonstrate the effect of the preferred additives upon the rheology of the combination of ingredients. The data presented in Table 5, except Example No. 44, is graphically portrayed in Figure 3 which contrasts crosshead speed and pounds of force to obtain the curves and in Figure 4 which converts the data in Table 5 into apparent viscosity (poise) and shear rate (seconds "" ), and contrasts apparent viscosity and shear rate to obtain the curves. EXAMPLES 49 to 52 Examples 49 to 52 were prepared for testing by Process S (see Example 1). The Rheology (Ametek drive) data for Examples 49 to 52 was determined using an Instron Rheometer, a melt temperature of 160° Centigrade, a die diameter of 0.05 inch, and a die length of 1.005 inches, and an Ametek Model LRS-20 drive unit produced by Ametek Testing Equipment Systems. The data obtained is set forth in Table 6. TABLE 6 RHEOLOGY (AMETEK DRIVE) AT 160°C Example No. Ingredients Pounds of Force 49 300 540 1000 1750 3801 50 J + 4% B + 250 520 910 1600 2750 1% A 51 J + 4% B + 260 500 900 1630 2620 1% G 52 J + 4% B + 250 500 940 1530 2760 1% H Crosshead Speed .02 0.1 0.5 2.0 5.0 (Inches/Minute) The data in Table 6 was presented to demonstrate the substantial equivalence of an ethylene-propylene polymer, an ethylene-acrylic acid polymer, and a low density polypropylene as high shear-flow aids. 5 The data presented in Table 6 is graphically plotted in Figure 5 wherein apparent viscosity (poise) is contrasted with shear rate (seconds " ). The curves for Examples 49, 50, 51, and 52- demonstrate that ethylene-acrylic acid and polypropylene may 10 be regarded as equivalent to an ethylene-propylene polymer in terms of acting as high shear-flow aids. EXAMPLES 53 to 55 Examples 53 to 55 were prepared for testing by Process S (see Example 27). The tests used to evaluate 15 physical properties of the examples are the same as those used for Examples 42 to 48 except that the tests for Vicat Heat Distortion and UL-94 Ignition Retardant Rating were not conducted. A test for Young's Modulus, measured in accordance with ASTM-D-638-77 in units of pounds per 20 square inch, was substituted for the tests not conducted. The results of the physical property evaluation are set forth in Table 7. TABLE 7 Example Izod Tensile Tensile Melt Flow Young's Modu No. Ingredients Impact Yield Rupture Elongation Rate (X 10 ) 53 J + 3% B + 1.5 3130 2445 47 4.1 2.9 1% A 54 J + 3% B + 1.47 3080 2405 40 4.9 2.85 lo. 55 J + 3% D + 1.5 3041 2330 41 5.2 2.94 1% F The data in Table 7 was presented to demonstrate the substantial equivalence of varying combinations of block copolymers and olefin polymers at a given level of block copolymer and olefin polymer from a physical property point of view. The Rheology (Instron Drive) data for Examples 53 to 55 was determined using an Instron Rheometer with a melt temperature of 160° Centigrade, a die diameter of 0.05 inch and a die length of 1.005 inches and an Instron Model TTC drive unit produced by Instron Engineering Corporation. The data obtained is set forth in Table 8. TABLE 8 RHEOLOGY (INSTRON DRIVE) AT 160°C No. Ingredients Pounds of Force 53 J + 3% B + 350 615 1200 2250 4000 5000 4700 1% A 54 J + 3% B + 320 602 1208 2350 3850 4650 4600 55 J + 3% D + 360 617 1172 2300 3650 4500 4700 1% F Crosshead Speed 02 .5 2.0 5.0 10 20 (Inches/Minutes) The data in Table 8 was presented to demonstrate the substantial equivalence as shear-flow aids of polyethylene and an ethylene-propylene copolymer and of linear block and radial block copolymers. The data presented in Table 8 is graphically portrayed in Figure 6 which is a plot of curves based on contrasting the parameters of apparent viscosity (poise) and shear rate (seconds ). All molecular weights used herein are in units of grams per mole. OMPI

Claims: WHAT IS CLAIMED IS: 1. A resinous composition having a reduced tendency to ignite, said composition comprising about 90.2 to about 65.3 parts by weight of rubber reinforced styrene polymer, about 0.8 to about 10 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n is 1 to 3, A represents a styrene polymer block and B represents a butadiene polymer block, said blo copolymer having a weight average molecular weight within the molecular weight range of about 50,000 to about 500,00 about 0.2 to about 4 parts by weight of an olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of an ethylenically unsaturated monomer polymerized therewith, about 7 to about 20 parts by weight of a halide-containing ignition retardant, and about 2 to about 6 parts by weight of a metal oxide. 2. A resinous composition having a reduced tendency to ignite, said composition comprising about 90.2 to about 65.3 parts by weight of rubber-reinforced styrene polymer, about 0.8 to about 10 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n is 1 to 3, A represents a styrene polymer P block and B represents a butadiene polymer block, said block copolymer having a weight average molecular weight within the molecular weight range of about 50,000 to about 500,000, about 0.2 to about 4 parts by weight of an olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of an ethylenically unsaturated monomer polymerized therewith, and the amounts of the block polymer and the olefin polymer, in relation to each other, in said resinous composition are represented by any point on or within the dashed line, or that portion of the abscissa lying between the ends of that dashed line of Figure 1, wherein the abscissa represents the parts by weight of the block polymer and the ordinate represents the parts by weight of the olefin polymer, and of Figure 2, which is a representation of a three-dimensional figure, wherein the abscissa and ordinate correspond directly with their counterparts in Figure 1 and the Z-axis represents the thickness of samples formed from said resinous composition and evaluated for V-O classification in accordance with UL-94, Tests for Flammability of Plastic Materials, about 10 to about 20 parts by weight of a halide-containing ignition retardant, and about 2 to 6 parts by weight of a metal oxide. 3. A resinous composition according to Claim 1 wherein the amount of block polymer is about 1.8 to about 4.3 parts by weight and the amount of olefin polymer is about 0.3 to about 1.3 parts by weight. 4. A resinous composition according to Claim 2 wherein the amount of block polymer is about 1.8 to about 4.3 parts by weight and the amount of olefin polymer is about 0.3 to about 1.3 parts by weight. 5. A resinous composition according to Claim 1 wherein the metal oxide is an antimony compound. 6. A resinous composition according to Claim 5 wherein the antimony compound is antimony trioxide. 7. A resinous composition according to Claim 2 wherein the metal oxide is an antimony compound. 8. A resinous composition according to Claim 7 wherein the antimony compound is antimony trioxide. 9. A resinous composition according to Claim 1 wherein the olefin polymer is an alpha-olefin polymer. 10. A resinous composition according to Claim 9 wherein the alpha-olefin polymer is an amorphous alpha-olefin polymer. 11. A resinous composition according to Claim 2 wherein the olefin polymer is an alpha-olefin polymer! 12. A resinous composition according to Claim 1 wherein the alpha-olefin polymer is an amorphous alpha-olefin polymer. 13. A resinous composition according to Claim 1 wherein the ethylenically unsaturated monomer is propylene 14. A resinous composition according to Claim 2 wherein the ethylenically unsaturated monomer is propylene 15. -A resinous composition according to Claim 1 wherein the olefin polymer has a specific gravity of about .82 to about .90 and a Mooney Viscosity of about 25 to about 50. 16. A resinous composition according to Claim 2 wherein the olefin polymer has a specific gravity of about .82 to about .90 and a Mooney Viscosity of about 25 to about 50. 17. A resinous composition according to Claim 1 wherein the reinforcing rubber is dispersed in the form of a plurality of particles, a majority of which have diameters within the range of about 0.2 to about 5 microns, and, within said plurality of reinforcing rubber particles, at least a majority have styrene polymer occluded therein. 18. A resinous composition according to Claim 2 wherein the reinforcing rubber is dispersed in the form of a plurality of particles, a majority of which have diameters within the range of about 0.2 to about 5 microns, and, within said plurality of reinforcing rubber particles, at least a majority have styrene polymer occluded therein. 19. A resinous composition according to Claim 1 wherein the block copolymer contains from about 10 to about 50 percent by weight styrene and from about 90 to about 50 percent by weight butadiene. 20. A resinous composition according to Claim 2 wherein the block copolymer contains from about 10 to about 50 percent by weight styrene and from about 90 to about 50 percent by weight butadiene. O 21. A resinous composition according to Claim 1 wherein the amount of halide-containing ignition retardan is from about 9 to about 15 parts by weight. 22. A resinous composition according to Claim 2 wherein the amount of halide-containing ignition retardant is from about 9 to about 15 parts by weight. 23. A resinous composition according to Claim 1 wherein said halide-containing ignition retardant is decabromodiphenyl oxide. 24. A resinous composition according to Claim 2 wherein said halide-containing ignition retardant is decabromodiphenyl oxide. 25. A resinous composition according to Claim 1 wherein the amount of metal oxide is from about 2.5 to abo 5 parts by weight. 26. A resinous composition according to Claim 2 wherein the amount- of metal oxide is from about 2.5 to abo 5 parts by weight. 27. A resinous composition having a reduced tendency to ignite, said composition comprising about 90.2 to about 65.3 parts by weight of rubber-reinforced styrene polymer, about 1.8 to about 4.3 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n is 1 to 3, A represents a styrene polymer block and B represents a butadiene polymer block, said blo copolymer having a weight average molecular weight within the molecular weight range of about 50,000 to about 500,00 ■ yύ ' kΕ Λ1 said copolymer containing from about 10 to about 50 percent by weight styrene and from about 90 to about 50 percent by weight butadiene, about 0.3 to about 1.3 parts by weight of an amorphous alpha-olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of propylene polymerized therewith, and the amounts of the styrene-butadiene block copolymer and the amorphous alpha-olefin polymer of ethylene and propylene, in relation to each other, in said resinous composition are represented by any point on or within the dashed line, or that portion of the abscissa lying between the ends of that dashed line of Figure 1, wherein the abscissa represents the parts by weight of the styrene-butadiene block copolymer and the ordinate represents the parts by weight of the amorphous alpha-olefin polymer of ethylene and propylene, and of Figure 2, which is a representation of a three-dimensional figure,, wherein the abscissa and ordinate correspond directly with their counterparts in Figure 1 and the Z-axis represents the thickness of samples formed from said resinous composition and evaluated for V-O classification in accordance with UL-94, Tests for Flammability of Plastic Materials, about 9 to about 15 parts by weight of decabromodiphenyl oxide and about 2.5 to about 5 parts by weight of antimony trioxide. 28. A physical blend of from about 90.2 to about 65.3 parts by weight of rubber-reinforced styrene polymer, about 0 to about 10 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n is 1 to 3, A represents a styrene polymer block and B represents a butadiene polymer block, said block copolymer having a weight average molecular weight within the ' OMPI molecular weight range of about 50,000 to about 500,000, about 0.2 to about 4 parts by weight of an olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of an ethylenically unsaturated monomer polymerized therewith, about 7 to about 20 parts by weight of a halide-containing ignition retardant, and about 2 to about 6 parts by weight of a metal oxide, which results in resinous composition, said composition possessing the desirable physical properties of improved processability a improved melt flow behavior in terms of high-shear flow. 29. A physical blend of from about 90.2 to abou 65.3 parts by weight of rubber-reinforced styrene polymer, about 0 to about 6 parts by weight of a styrene butadiene block copolymer having the configuration A(BA) , where n i 1 to 3, A represents a styrene polymer block and B represents a butadiene polymer block, said block copolymer having a weight average molecular weight within the molecular weight range of about 50,000 to about 500,000, about 0.3 to 1.3 parts by weight of an olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of an ethylenically unsaturated monomer polymerized therewith, and the amounts of the block copolymer and the olefin polymer, in relation to each othe in said resinous composition are represented by any point or within the dashed line, or that portion of the abscissa lying between the ends of that dashed line of Figure 1, wherein the abscissa represents the parts by weight of the block polymer and the ordinate represents the parts by weight of the olefin polymer, and of Figure 2, which is a representation of a three-dimensional figure, wherein the abscissa and ordinate correspond directly with their 3 counterparts in Figure 1 and the Z-axis represents the thickness of samples formed from said resinous composition and evaluated for V-O classification in accordance with UL-94, Tests for Flammability of Plastic Materials, about 7 to about 20 parts by weight of a halide-containing ignition retardant, and about 2 to about 6 parts by weight of a metal oxide, which results in a resinous composition, said composition possessing the desirable physical properties of improved processability and improved melt flow behavior in terms of high-shear flow. 30. A resinous composition according to Claim 28 wherein the amount of block copolymer is about 1.8 to about 4.3 parts by weight and the amount of amorphous alpha-olefin polymer is about 0.3 to about 1.3 parts by weight. 31. A resinous composition according to Claim 29 wherein the amount of block polymer is about 1.8 to about 4.3 parts by weight and the amount of amorphous alpha-olefin polymer is about 0.3 to about 1.3 parts by weight. 32. A resinous composition according to Claim 28 wherein the metal oxide is an antimony compound. 33. A resinous composition according to Claim 31 wherein the antimony compound is antimony trioxide. 34. A resinous composition according to Claim 29 wherein the metal oxide is an antimony compound. 35. A resinous composition according to Claim 33 wherein the antimony compound is antimony trioxide. 36. A resinous composition according to Claim 27 wherein the olefin polymer is an alpha-olefin polymer. / C PI 37. A resinous composition according to Claim 3 wherein the alpha-olefin polymer is an amorphous alpha-olefin polymer. 38. A resinous composition according to Claim 2 wherein the olefin polymer is an alpha-olefin polymer. 39. A resinous composition according to Claim 3 wherein the alpha-olefin polymer is an amorphous alpha-olefin polymer. 40. A resinous composition according to Claim 2 wherein the ethylenically unsaturated monomer is propylene 41. A resinous composition according to Claim 2 wherein the ethylenically unsaturated monomer is propylene 42. A resinous composition according to Claim 2 wherein the olefin polymer has a specific gravity of about .82 to about .90 and a Mooney Viscosity of about 25 to abo 50. 43. A resinous composition according to Claim 2 wherein the olefin polymer has a specific gravity of about .82 to about .90 and a Mooney Viscosity of about 25 to abo 50. 44. A resinous composition according to Claim 1 wherein the reinforcing rubber is dispersed in the form of plurality of particles, a majority of which have diameters with the range of about 0.2 to about 5 microns, and, withi said plurality of reinforcing rubber particles, at least a majority have styrene polymer occluded therein. 45. A resinous composition according to Claim 1 wherein the block copolymer contains from about 10 to about 50 percent by weight styrene and from about 90 to about 50 percent by weight butadiene. 46. A resinous composition according to Claim 28 wherein the amount of halide-containing ignition retardant is from about 9 to about 15 parts by weight. 47. A resinous composition according to Claim 29 wherein the amount of halide-containing ignition retardant is from about 9 to about 15 parts by weight. 48. A resinous composition according to Claim 28 wherein said halide-containing ignition retardant is decabromodiphenyl oxide. 49. A resinous composition according to Claim 29 wherein said halide-containing ignition retardant is decabromodiphenyl oxide. 50. A resinous composition according to Claim 28 wherein the amount of metal oxide is from about 2.5 to about 5 parts by weight. 51. A resinous composition according to Claim 29 wherein the amount of metal oxide is from about 2.5 to about 5 parts by weight. 52. A physical blend of from about 90.2 to about 65.3 parts by weight of rubber-reinforced styrene polymer, about 0 to about 6 parts by weight of a styrene-butadiene block copolymer having the configuration A(BA) , where n is 1 to 3, A represents a styrene polymer block and B 6 represents a butadiene polymer block, said block copolyme having a weight average molecular weight within the molecular weight range of about 50,000 to about 500,000, said copolymer containing from about 10 to about 50 perce by weight styrene and from about 90 to about 50 percent b weight butadiene, about 0.3 to about 1.3 parts by weight o an amorphous alpha-olefin polymer, having polymerized therein from about 40 to about 100 percent by weight of ethylene and from about 60 to about 0 percent by weight of propylene polymerized therewith, and the amounts of the styrene-butadiene block copolymer and the amorphous alpha-olefin polymer of ethylene and propylene in relation to each other in said resinous composition are represented by any point on or within the dashed line, or that portion of the abscissa lying between the ends of that dashed line of Figure 1, wherein the abscissa represents the parts by weight of the styrene-butadiene block copolymer and the ordinate represents the parts by weight of the amorphous alpha-olefin polymer of ethylene and propylene, and of Figure 2, which is a representation of a three-dimensional figure, wherein the abscissa and ordinate correspond directly with their counterparts in Figure 1 and the Z-axi represents the thickness of samples formed from said resinous composition and evaluated for V-O classification accordance with UL-94, Tests for Flammability of Plastic Materials, about 9 to about 15 parts by weight of decabromodiphenyl oxide, and about 2.5 to about 5 parts by weight of antimony trioxide, which results in a resinous composition, said composition possessing the desirable physical properties of improved processability and improve melt flow behavior in terms of high-shear flow. O

Inventors: KENT R, LUCK H
Applicants: DOW CHEMICAL CO, DOW CHEM CO
Application year: 1980
Main classification: C08K5
IPC codes: C08K3, C08K5, C08K13, C08L23, C08L25, C08L51, C08L53