MOLECULAR WEIGHT DISTRIBUTION MODIFICATION IN TUBULAR REACTOR

Abstract: Novel copolymers of alpha-olefins comprised of intramolecularly heterogeneous and intermolecularly homogeneous copolymer claims prepared by a process as outlined schematically in Fig. 1.

Description: MOLECULAR WEIGHT DISTRI ODIFICA ION IN A TUBULAR REACTOR CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of Application Serial Number 681,951, filed December 14, 1985, which in turn is a continuation-in-part of Serial Number 504,582, filed June 15, 1983, the disclosure of which are herein incorporated by reference thereto. MOLECULAR WEIGHT DISTRIBUTION MODIFICATION IN TUBULAR REACTOR Background of the Invention The present invention relates to novel co¬ polymers of alpha-olefins. More specifically, it re¬ lates to novel copolymers of ethylene with other alpha-olefins which have a polymodal molecular weight distribution wherein individual nodes comprising the polymer have narrow molecular weight distributions. For convenience, certain terms that are re¬ peated throughout the present specification are defined, below: (a) Inter-CD defines compositional variation, in terms of ethylene content, among polymer chains. It is expressed as the minimum deviation (analogous to a standard deviation) in terms of weight percent ethylene from the average ethylene composition for a given co- polymer sample needed to include a given weight percent of the total copolymer sample which is obtained by ex¬ cluding equal weight fractions from both ends of the distribution. The deviation need not be symmetrical. When expressed as a single number, for example, 15% Inter-CD, it shall mean the larger of the positive or negative deviations. For example, for a Gaussian compo¬ sitional distribution, 95.52 of the polymer is ithin 20 vtZ ethylene of the mean if the standard deviation is 101. The Inter-CD for 95.5 wtZ of the polymer is 20 wtZ ethylene for such a sample. (b) Intra-CD is the compositional variation, in terms of ethylene, within a copolymer chain. It is b____ expressed as the minimum difference in weight (wt) Z ethylene that exists between two portions of a single copolymer chain, each portion comprising at least 5 wtZ of the chain. (c) Molecular weight distribution (MWD) is a measure of the range of molecular weights within a given copolymer sample. It is characterized in terms of at least one of the ratios of weight average to number av¬ erage molecular weight, M /M , and Z average to weight average molecular weight, M 2/MW, where: MW =_-_r-_NT T iM>i -NiMfi_' M_ - -_=. NiMi J , and l±h± 2 Ni is the number of molecules of weight Mi. Ethylene-propylene copolymers, particularly elastomers, are important commercial products. Two basic types of ethylene-propylene copolymers are commer¬ cially available; ethylene propylene copolymers and ethylene propylene terpolymers. Ethylene-propylene co¬ polymers (EPM) are saturated compounds requiring vulcan¬ ization with free radical generators such as organic peroxides. Ethylene-propylene terpolymers (EPDM) con¬ tain a small amount of non-conjugated diolefin, such as dicyclopentadiene; 1,4-hexadiene or ethylidene nor- bornene, which provides sufficient unsaturation to per¬ mit vulcanization with sulfur. Such ethylene-propylene polymers that include at least two monomers, i.e., EPM . and EPDM, will * be hereinafter collectively referred to as ethylene-propylene copolymers. These copolymers have outstanding resistance to weathering, good heat aging properties and the abil¬ ity to be compounded with large quantities of fillers and plasticizers resulting in low cost compounds which are particularly useful in automotive and industrial mechanical goods applications. Typical automotive uses are tire sidewalls, inner tubes, radiator and heater hose, vacuum tubing, weather stripping, sponge doorseals and Viscosity Index (V.I.) improvers for lubricating oil compositions. Typical mechanical goods uses are for ap¬ pliance, industrial and garden hoses, both molded and extruded sponge parts, gaskets and seals and conveyor belt covers. These copolymers also find use in adhe- sives, appliance parts as in hoses and gaskets, wire and cable and plastics blending. As can be seen from the above, based on their respective properties, EPM and EPDM find many, varied uses. It is known that the properties of such copoly¬ mers which make them useful in a particular application are, in turn, determined by their composition and struc¬ ture. For example, the ultimate properties of an EPM. and EPDM copolymer are determined by such factors as composition, compositional distribution, sequence dis¬ tribution, molecular weight, and molecular weight dis¬ tribution (MWD) . The efficiency of peroxide curing depends on composition. As the ethylene level increases, it can be shown that the "chemical" crosslinks per peroxide mole¬ cule increases. Ethylene content also influences the rheological and processing properties, because crystal- linity, which acts as physical .crosslinks, can be intro¬ duced. The crystallinity present at very high ethylene contents may hinder processability and may make the cured product too "hard" at temperatures below the crys¬ talline melting point to be useful as a rubber. ' Milling behavior of EPM or EPDM copolymers varies radically with MWD. Narrow MWD copolymers crum¬ ble on a mill, whereas broad MWD materials will band un¬ der conditions encountered in normal processing opera¬ tions. At the shear rates encountered in processing equipment, broader 2-IWD copolymer has a substantially lower viscosity than narrower MWD copolymer of the same weight average molecular weight or low strain rate vis¬ cosity. Thus, there exists a continuing need for dis¬ covering polymers with unique properties and composi¬ tions. For elastomer applications the processability is often measured by the Mooney viscosity. The lower this quantity the easier the elastomer is to mix and fabricate. It is desirable to have low Mooney yet to maintain a high number average molecular weight, M , so that the polymers form good rubber networksupon cross- linking. For EP and EPDM, narrowing the molecular weight distribution results in the production of polymer with higher number average molecular weight at a given Mooney than the broader distribution polymer. In cer¬ tain cases, the poor milling, calendering or extrusion behavior that results from the narrow MWD must be ame¬ liorated. Rather than perform a MWD broadening which includes low molecular weight components which reduce M , it is possible to broaden the MWD without dispropor¬ tionately lowering M . This is done by superposing one or more narrow MWD modes, i.e., different Mooney compo¬ nents, each of which contains no appreciable amount of low molecular weight polymer. The result is a polymodal molecular weight distribution comprised of narrow MWD polymer fractions of different molecular weights. The present invention is drawn to a novel co¬ polymer of ethylene and at least one other alpha-olefin monomer which copolymer is composed of several such MWD components each of which is very narrow. It is well known that the breadth of the MWD can be characterized by the ratios of various molecular weight averages. For example, an indication of the narrow MWD of each compo¬ nent in accordance with the present invention is that the ratio of weight to number average molecular weight (M /Mn) is less than 2. Alternatively, a ratio of the Z-average molecular weight to the weight average molecu¬ lar weight (M./M j . of less than 1.8 typifies a narrow MWD in accordance with the present invention. It is known that the property advantages of copolymers in ac¬ cordance with the present invention are related to these ratios. Small weight fractions of material can dispro¬ portionately influence these ratios while not signifi¬ cantly altering the property advantages which depend on them. For instance, the presence of a small weight fraction (e.g. , 27. ) of low molecular weight copolymer can dep r ress M_,, and thereby ■ ' raise w_ /M„n above 2 while maintaining M /M less than 1.8. Therefore, the compo¬ nent polymers, in accordance with the present invention, are characterized by having at least one of two charac¬ teristics; w. /M_n less than 2 and Mz/Mw less than 1.8. To obtain narrow MWD, the copolymers in accordance with the present invention are preferably made in a tubular reactor. It has been discovered that to produce such, copolymers requires the use of numerous heretofore un¬ disclosed method steps conducted within heretofore un¬ disclosed preferred ranges. Accordingly, the present invention is also drawn to a method for making the novel copolymers of the present invention. Description of the Prior Art Representative prior art dealing with tubular reactors to make copolymers are as follows: In "Polymerization of ethylene and propylene to amorphous copolymers with catalysts of vanadium oxy- chloride and alkyl aluminum halides"; E. Junghanns, A. Gu boldt and G. Bier; Makromol. Chem, v. ,5_8 (12/12/62): 18-42, the use of a tubular reactor to produce ethylene- propylene copolymer is disclosed in which the composi¬ tion varies along the chain length. More specifically, this reference discloses the production in a tubular reactor of amorphous ethylene-propylene copolymers using Ziegler catalysts prepared from vanadium compound and aluminum alkyl. It is disclosed that at the beginning of the tube ethylene is preferentially polymerized, and if no additional make-up of the monomer mixture is .made during the polymerization the concentration of monomers changes in favor of propylene along the tube. It is. further disclosed that since these changes in concentra¬ tion take place during chain propagation, copolymer chains are produced which contain more ethylene on one end than at the other end. It is also disclosed that copolymers made in a tube are chemically non-uniform, but fairly uniform with respect to molecular weight dis¬ tribution. Using the data reported in their Figure 17 for copolymer prepared in the tube, it was estimated that the Mw/Mn ratio for this copolymer was 1.6. "Laminar Flow Polymerization of EPDM Polymer"; J.F. Wehner; ACS Symposium Series 65 (1978); pp 140-152 discloses the results of computer simulation work under- taken to determine the effect of tubular reactor solu¬ tion polymerization with Ziegler catalysts on the molec¬ ular weight distribution of the polymer product. The specific polymer simulated was an elastomeric terpolymer of ethylene-propylene-1, 4-hexadiene. On page 149, it is stated that since the monomers have different reac¬ tivities, a polymer of varying composition is obtained as the monomers are depleted. However, whether the com¬ position varies inter- or intramolecularly is not dis¬ tinguished. In Table III on page 148, various polymers having M-^/M of about 1.3 are predicted. In the third paragraph on page 144, it is stated that as the tube di¬ ameter increases, the polymer molecular weight is too low to be of practical interest, and it is predicted that the reactor will plug. It is implied in the first paragraph on page 149 that the compositional dispersity produced in a tube would be detrimental to product qual¬ ity. U.S. 3,681,306 is drawn to a process for producing ethylene/higher alpha-olefin copolymers having good processability, by polymerization in at least two consecutive reactor stages. According to this refer¬ ence, this two-stage process provides a simple polymeri¬ zation process that permits tailor-making ethylene/ alpha-olefin copolymers having predetermined properties,, particularly those contributing to processability in commercial applications such as cold-flow, high green strength and millability. Allegedly, the disclosed pro¬ cess is particularly adapted for producing elastomeric copolymers, such as ethylene/ propylene/5-ethylidene-2- norbornene, using any of the coordination catalysts use¬ ful for making EPDM. The preferred process uses one tubular reactor followed by one pot reactor. However, it is also disclosed that one tubular reactor could be used, but operated at different reaction conditions to simulate two stages. As is seen from the disclosure at column 2, lines 14-20, the process makes polymers of broader MWD than those made in a single stage reactor. Although intermediate polymer from the first (pipeline) reactor is disclosed as having a ratio of M,w/M„n of about 2 (column 5, lines 54-57) the final polymers produced by the process have an Mw/M„n of 2.4 to 5. U.S. 3,625,658 co Closon discloses a closed circuit tubular reactor apparatus with high S recirculation rates of the reactants which can be used to make elastomers of ethylene and propylene. With par¬ ticular reference to Fig. 1 of the patent, a hinged sup¬ port 10 for vertical leg 1 of the reactor allows for horizontal expansion of the bottom leg thereof and pre¬ vents harmful deformations due to thermal expansions, particularly those experienced during reactor clean out. U.S. 4,065,520 to Bailey et al. discloses the use of a batch reactor to make ethylene copolymers, in¬ cluding elastomers, having broad compositional distribu¬ tions. Several feed tanks for the reactor are arranged in series, with the feed to each being varied to make the polymer. The products made have crystalline to semi-crystalline to amorphous regions and gradient changes in between. The catalyst system can comprise vanadium compounds alone or in combination with titanium compounds and is exemplified by vanadium oxy-tri-chlo- ride and diisobutyl aluminum chloride. In all of the. examples, titanium compounds are used. In several exam¬ ples, hydrogen and diethyl zinc, known transfer agents, are used. The polymer chains produced have a composi- tionally disperse first length and uniform second length. Subsequent lengths have various other composi¬ tional distributions. In "Estimation of Long-Chain Branching in Ethylene-Propylene Terpolymers from Infinite-Dilution Viscoelastic Properties"; Y. Mitsuda, J. Schrag, and J. Ferry; J. Appl. Pol. Sci. , __S , .193 (1974) narrow MWD co¬ polymers of ethylene-propylene are disclosed. For exam¬ ple, in TABLE II on page 198, EPDM copolymers are dis¬ closed which have w / n of from 1.19 to 1.32. In "The Effect of Molecular Weight and Molecu¬ lar Weight Distribution on the Non-Newtonian Behavior of Ξthylene-Propylene-Diene Polymers; Trans. Soc. Rheol., 14, 83 (1970); C. . Shih, a whole series of composition- ally homogeneous fractions were prepared and disclosed. For example, the data in TABLE I discloses polymer Sample B as having a high degree of homogeneity. Also, based on the reported data, the MWD of the sample is very narrow. However, the polymers are not disclosed as having intramolecular dispersity. Molecular weight distribution (MWD) is a very important characteristic of ethylene-propylene copoly¬ mers and terpolymers. Favorable distributions result in polymers which can have both faster cures and better processing characteristics. An optimum combination of these properties is achieved where the polymers have a polymodal molecular weight distribution and a polymodal compositional distribution. A significant amount of effort has been ex¬ pended by the polymer- industry in an attempt to produce such polymodal ethylene-propylene polymers. Generally, these efforts have been directed toward physical blends of polymers having different l-ϊWD or by sequential poly¬ merization in a multiple reactor system. For example, a. polymerization is carried out in a first reaction stage to produce a polymer of a particular MWD and composition with a subsequent polymerization in a second reactor stage to produce a polymer of a different MWD from that of the first stage and, if desired, of a different mono¬ mer composition. Representative prior art dealing with the preparation of bimodal MWD ethylene-propylene co¬ polymers are as follows: British Patent No. 1,233,599 is illustrative of two stage polymerization processes. While copolymers of ethylene are incidently disclosed, the examples and disclosure are directed toward polyethylene homopolymers and crystalline copolymers, e.g., 95Z ethylene. The preferred catalysts are vanadium compounds ' such as vanadyl halide, vanadium tetrachloride or vanadium tris- (acetyl-acetonate) in conjunction with an aluminum compound, e.g., Br^AlCH Br 2 » The different MW s are ob¬ tained by using differing amounts of hydrogen in the first and second stage polymerization. U.S. Patent No. 4,078,131 discloses an ethyl¬ ene-propylene rubber composition having a bimodal dis¬ tribution in molecular weights comprising two polymer fractions each having a wide distribution of molecular weights and a monomer composition different from that of the other principal fractions. The polymers are further characterized in that they are formed of: (a) a first principal fraction comprising from about 30% to about 85Z (by weight referred to the total weight of elasto¬ mers) of molecular weight fractions having an intrinsic viscosity distribution of from about 0.2 to about 3, and average intrinsic viscosity between about 0.8 to about 1.5, an average propylene content between about 36 to about 52% by weight, and a termonomer content of between 0% and about 5%, and of (b) a second fraction comprising about 70% to about 15% by weight of molecular weight fractions having an intrinsic viscosity distribution from about 3 to about 15, an average intrinsic viscosity of about 3.5 to about 7, and average propylene content of between about 26% to about 32% by weight and a ter¬ monomer content of about 0 to about 5%. The polymers are prepared by carrying out polymerization in two separate reactors connected in se¬ ries. The catalyst systems utilized include organic and inorganic component of a transition metal of Group 4A to 8A of the Mendeleev periodic table of the elements, e.g., VOC1-, VCl,, vanadium esters and acetyl aceton- ates. Co-catalysts include organoaluminum compounds or mixtures of compounds, e.g., aluminum alkyIs. U.S. Patent 3,681,306 discloses a two stage polymerization process for the preparation of ethylene- propylene co-and terpolymers. In one embodiment the •first stage is a "pipe reactor" and the second stage is a back-mixed pot reactor. The polymerization is carried out so that the average ethylene/alpha olefin ratio in one state is at least 1.3 tines the average ratio of the other stage. Any of the coordination catalysts know to be useful in producing EPDM polymers is said to be ef¬ fective for the process. U.S. Patent No. 4,259,468 discloses a broad molecular weight ethylene-propylene-diene rubber pre¬ pared using as a catalyst (a) the alcohol reaction prod¬ uct of vanadium oxytrichloride and (b) a mixture of alu¬ minum sesquichloride and ethylaluminu dichloride. The polymer is characterized in that the higher molecular weight fraction contains a larger proportion of the diene than does the lower molecular weight fraction. The polymer has an intrinsic viscosity of about 1.0 to about 6.0 dl/g and a weight average molecular weight/ number ratio of about 3 to about 15. U.S. Patent No. 4,306,401 discloses a method of manufacture of EPDM type terpolymers which utilizes a two stage polymerization process. Substantially all of the non-conjugated diene monomer is fed to the first stage thereby producing a polymer having a non-uniform' diene content. Brief Description of the Drawings The accompanying drawings depict, for illus¬ tration purposes only, processes embodied by the present invention, wherein: Fig. 1 is a schematic representation of a pro¬ cess for producing polymer in accordance with the pre¬ sent invention. Fig. 2 schematically ' illustrates a polymodal MWD polymer comprising narrow MWD polymers for each mode, Fig. 3 is a graphical illustration of a tech¬ nique for determining Intra-CD of a copolymer, Fig. 4 graphically illustrates various copoly¬ mer structures that can be attained using processes in accordance with the present invention. Detailed Description of the Invention The instant invention relates to a novel co¬ polymer of ethylene and at least one other alpha-olefin monomer, which copolymer is a superposition of two or more copolymers, each of which has a MWD characterized by having at least one of two characteristics; an M /M of less than 2 and M /M of less than 1.8. As already noted, copolymers in accordance with the present invention are comprised of ethylene and at least one other alpha-olefin. Such alpha-olefins can • include those containing 3 to 18 carbon atoms. Alpha- olefins of 3 to 6 carbons are preferred becavse of eco¬ nomic considerations. Illustrative non-limiting examples of alpha olefins useful in the practice of this invention are propylene, butene-1, pentene-1, hexene-1, heptene-1, oc ene-1 , dodecene-1 , etc. The most preferred copoly¬ mers in accordance with the present invention are those " comprised of ethylene and propylene or ethylene, 'propyl¬ ene and non-conjugated diene. As is well known to those skilled in the art, copolymers of ethylene and higher alpha-olefins such as propylene often include other polymerizable monomers. Typical of these other monomers can be non-conjugated dienes. Illustrative non-limiting examples of such non-conjugated dienes are: a. straight chain acyclic dienes such as: 1,4-hexadiene; 1 ,6-octadiene; b. branched chain acyclic dienes such as: 5-methyl-l, 4-hexaαiene; 3,7-dimethyl-l, 6- octadiene; 3,7-dimethyl-l,7-octadiene and the mixed isomers of dihydro-myrcene; c. single ' ring alicyclic dienes such as: 1 ,4-cyclohexadiene; 1,5-cyclooctadiene; and 1,5-cyclododecadiene; d. multi-ring alicyclic fused and bridged ring dienes such as: tetrahydroindene; methyltetrahydroindene; dicyclopentadiene; bi- cyclo-(2,2,l)-hepta-2,5-diene; alkenyl, alkyl- idene, cycloalkenyl and cycloalkylidene nor- bornenes such as 5-methylene-2-norbornene (MNB) , 5-ethylidene-2-norbornene (ENB) , 5-pro- pylidene-2-norbornene, 5-isopropylidene-2*morbor- nene, 5- (,4-cyclopentenyl).-2-norbornene; 5-cyclo- hexylidene-2-norbornene. • Of the non-conjugated dienes typically used to prepare these copolymers, dienes containing at least one of the double bonds in a strained ring are preferred. The most preferred diene is 5-ethylidene-2- ' norbornene (EΪ7B) . The amount of diene (wt. basis) in the copolymer can be about 0% to 20% with 0Z to 15% being preferred. The most preferred range is 0Z to 10Z. As• already noted, the most preferred copolymer in accordance with the present invention is ethylene- propylene or ethylene-propylene non-conjugated diene. In either event, the average ethylene content of each component of these copolymers can be as lew as about 10Z on a weight basis. The preferred minimum ethylene con¬ tent is about 25Z. A more preferred minimum is about 301. The maximum ethylene content can be about 90Z on a weight basis. The preferred maximum is about 85Z, with the cost preferred being about 80%. The molecular weight of the component copoly¬ mer made in accordance with the present invention can vary over a wide range. The weight average molecular weight (M ) can be as low as about 2,000. The preferred minimum is about 10,000. The most preferred minimum is about 20,000. The maximum weight average molecular weight can be as high as about 12,000,000. The pre¬ ferred maximum is about 1,000,000. The most preferred maximum is about 750,000. Another feature of the copolymers made in ac¬ cordance with the present invention is that the molecu¬ lar weight distribution (MlvD) of each component is very narrow, as characterized by having at least one of two characteristics; a ratio of Mw/Mn of less than 2 and a ratio of g / w of less than 1.8. The M„/M ratio for the whole copolymer can range from about 1 to about 50. The and MWD of the copolymer is controlled by adjust¬ ing the M and weight fraction of polymer that make up the individual narrow MWD components. In a preferred ■ embodiment, the M of any two adjacent MWD modes should differ by at least 50Z and any one mode chould com¬ prise at least 10 wtZ of the total copolymer. As it re¬ lates to EPM and EPDM, a typical advantage of such co- pclymers composed of several modes having narrow MWD is that when compounded and vulcanized, faster cure and better physical properties result than when copolymers having lower M for a given Mooney are used. Processes in accordance with the present in¬ vention produce copolymer by polymerization of a reac¬ tion mixture comprised of catalyst, ethylene, at least one additional alpha-olefin monomer, and optionally, a ncn- conjugated diene. Solution polymerizations are preferred. Any known solvent for the reaction mixture that is effective for the purpose can be used in con¬ ducting solution polymerizations in accordance with the present invention. For example, suitable solvents are hydrocarbon solvents such as aliphatic, cycloaliphatic and aromatic hydrocarbon solvents, or halogenated ana¬ logs of such solvents. The preferred solvents are C, to C, , straight chain or branched chain, saturated hydro- carbons, d- to C g saturated alicyclic or aromatic hydro¬ carbons or C« to Cg halogenated hydrocarbons. Most pre¬ ferred are C fi to C, « , straight chain or branched chain hydrocarbons, particularly hexane. Nonlimiting illus¬ trative examples of such solvents are butane, pentane, hexane, heptane, cyclopentane, cyclohexane, cyclohep- tane, methyl cyclopentane, methyl cyclohexane, isooc- tane, benzene, toluene, xylene, chloroform, chloro- benzenes, tetrachloroethylene, dichloroethane and trichloroethane. A number of processes can be used to prepare the copolymer products of this invention. These pro¬ cesses are based on carrying out the copolymerization in a batch or tubular reactor. As described in our co- pending patent application, Serial Number 504,582, co¬ p r oly J mers of narrow MWD with Mw/M_n less than 2.0 or Mz/'Mw less than 1.8 can be obtained by operating such reactors at certain specified conditions. Firstly, in the course of the polymerization, substantially no mixing must occur between polymer chains that have been initiated at different times. This condition is defined as "mix free." Tubular reactors are well known and are designed to minimize mixing of the reactants in the direction of flow. As a- result, reactant concentration will vary along the reactor length. In contrast, the reaction mixture in a continuous flow stirred tank reactor (CFSTR) is blended with the incoming feed to produce a solution of essentially uniform composition everywhere in the reactor. Consequently, the growing chains in a portion of the reaction mixture will have a variety of ages and thus a single CFSTR is not suitable for the process of this invention. However, it is well known that 3 or more stirred tanks in series with all of the catalyst fed to the first reactor can approximate the performance of a tubular reactor. Accordingly, such tanks in series are considered to be in accordance with the present invention. A batch reactor is a suitable reaction vessel in which to carry out the process of this invention, preferably equipped with adequate agitation. The cata¬ lyst, solvent, and monomer are added to the reactor at the start of the polymerization. The charge of reactants is then left to polymerize for a time long enough to produce the desired product. For economic reasons, a tubular reactor is preferred to a batch reac¬ tor for carrying out the processes of this invention. In addition to the importance of the reactor system to make narrow MWD component copolymers the poly¬ merization should be conducted in a manner such that for each component or mode in the MWD: a. the catalyst system produces essentially one active catalyst species, b. the reaction mixture is essentially free of chain transfer agents, and c « for each mode the polymer chains are es¬ sentially all initiated simultaneously, which is at the same time for a batch reactor or at the same point along the length of the tube for a tubular reactor. The desired polymer can also be obtained if additional solvent and reactants (e.g., at least one of the ethylene, alpha-olefin and diene) are added either along the length of a tubular reactor or during the course of polymerization in a batch reactor. Operating in this fashion can be desirable in certain circum¬ stances to control the pol merization rate or polymer composition. However, it is necessary to add the cata¬ lyst at the inlet or specific locations of the tube or at the onset of or at specific times in batch reactor operation to meet the requirement that for each mode .. essentially all polymer chains are initiated simultaneously. Accordingly, narrow MWD component copolymers are produced by carrying out a polymerization reaction: (a) in a least one mix free reactor, (b) using catalyst systems such that each com¬ ponent or mode in the MWD is produced by essentially one active catalyst species; (c) using at least one reaction mixture which is essentially transfer agent-free, and (d) in such a manner and under conditions suf¬ ficient to initiate propagation of essentially all poly¬ mer chains made with a particular catalyst species simultaneously. To produce the multimodal MWD polymer of this invention, these polymerization conditions are used to generate each of the narrow MWD modes that comprise the final polymer product. A number of techniques are available for achieving this: 1) In a single mix free reactor operated as described above, portions of the polymer product can be withdrawn after varying times in a batch reactor or* at varying distances along a tubular reactor representing different average molecular weights and these portions can be blended.. 2) Mix free reactors can be operated either in parallel or sequentially and the products blended. 3) Two or more catalysts that form narrow MWD. polymer of. differing molecular weight can be added at the onset of polymerization in a mixfree reactor. Each catalyst must meet the requirements of minimizing chain transfer and initiating simultaneous propagation of all the chains produced by that catalyst. 4) A catalyst system that generates multiple active catalyst species can be added at the start of the polymerization. Each catalyst species produced must give simultaneous chain initiation and minimize chain transfer. 5) Additional catalyst and monomer, if desired, can be added at varying lengths along a tubular reactor or times in a batch reactor to initiate the for¬ mation of additional MWD modes. The catalysts can be the same or different, as long as chains are initiated simultaneously and chain transfer is minimized. 6) For catalyst system that show a decay in activity as a function of time due to deactivation, cat¬ alyst reactivator can be added during the course of the polymerization to regenerate the dead catalyst and form a new mode of narrow MWD copolymer. Catalyst reactivators- are well known in the art for increasing the productivity of vanadium Ziegler catalysts.. These materials rejuvenate catalyst sites that have become inert due to termination reactions and thereby cause reinitiation of polymer chain growth. When added to a reactor operating according to the pro¬ cess of this invention, catalyst reactivators have an effect similar to that of adding a second catalyst feed. Many reactivators are known, and examples of suitable materials can be found in U.S. Patents 3,622,548, 3,629,212, 3,723,348, 4,168,358, 4,181,790 and 4,361,686. Esters of chlorinated organic acids are pre¬ ferred reactivators for use with the vanadium catalyst systems of this invention. Especially preferred is butyl perchlorocrotanate. In the processes of this invention that uti¬ lize multiple catalysts or multiple catalyst additions during the course of polymerization the mix free condi¬ tion of the reactor refers to the polymer chains of each individual mode of the MWD and not to the polymer as a whole. A preferred multiple catalyst system comprises VC1, combined with V0C1, and an alkyl aluminum sesqui- halide as a cocatalyst. The resultant polymer is a bimodal MWD polymer. Since the present invention is considered to be most preferred in the context of ethylene-propylene (EPM) or ethylene-propylene-diene (EPDM) copolymers, it will be described in detail in the context of EPM and/or EPDM. Copolymer in accordance with the present in¬ vention is preferably made in a tubular reactor. When produced in a tubular reactor with monomer feed only at the tube inlet, it is known that at the beginning of the tubular reactor ethylene, due to its high reactivity, will be preferentially polymerized. However, the con¬ centration of monomers changes along the tube in favor of propylene as the ethylene is depleted. The result is copolymer chains which are higher in ethylene concen¬ tration in the chain segments grown near the reactor in¬ let (as defined at the point at which the polymerization reaction commences), and higher in propylene concen¬ tration in the chain segments formed near the reactor outlet. An illustrative copolymer chain of ethylene- propylene is schematically presented below the E repre¬ senting ethylene constituents and P representing propylene constituents in the chain: 1 2 3 4 Segment: E-E-E-E-P-E-E-E-P-P-E-E-P-P-P-E-P-P-P-P ' As can be seen from this illustrative schemat¬ ic chain, the far left-hand segment (1) thereof repre¬ sents that portion of the chain formed at the reactor inlet where the reaction mixture is proportionately richer in the more reactive constituent ethylene. This segment comprises four ethylene molecules and one propy¬ lene molecule. However, as subsequent segments are formed from left to right with the more reactive ethy¬ lene being depleted and the reaction mixture proportion¬ ately increasing in propylene concentration, the subse¬ quent chain segments become more concentrated in propylene. The resulting chain is intramolecularly het¬ erogeneous. In the event that more than two monomers are used, e.g. , in the production of EPDM using a diene ter- monomer, for purposes of describing the present inven¬ tion all properties related to homogeneity and. hetero¬ geneity will refer to the relative ratio of ethylene to the other monomers in the chain. The property, of the copolymer discussed herein, related to intramolecular compositional dispersity (compositional variation within a chain) shall be referred to as Intra-CD, and that related to intermolecular compositional dispersity (compositional variation between chains) shall be re¬ ferred to as Inter-CD. For copolymers in accordance with the present invention, composition can vary between chains as well as along the length of the chain. In one embodiment of this invention, the Inter-CD can be characterized by the difference in composition between some fraction of the copolymer and the average composition, as well as by the total difference in composition between the copolymer fractions containing the highest and lowest quantity of ethylene. Techniques for measuring the breadth of the Inter-CD are known as illustrated by Junghanns, et al., wherein a p-xylene-dimethylformamide solvent/non-solvent was used to fractionate copolymer into fractions of dif¬ fering intermolecular composition. Other solvent/non- solvent systems can be used, such as hexane-2-propanol, as will be discussed in more detail below. In one embodiment of this invention, the ' Inter-CD of the individual component copolymers in ac¬ cordance with the present invention is such that 95 wt% of the copolymer chains have an ethylene composition that differs from the average component weight percent ethylene composition by 15 wt% or less. The preferred Inter-CD is about 13% or less, with the most preferred being about 10% or less. In comparison, Junghanns, et al. , found that their tubular reactor copolymer had an Inter-CD of greater than 15 wt%. Broadly, in one embod¬ iment of this invention, the Intra-CD of copolymer in accordance with the present invention is such that at least two portions of an individual component intramo¬ lecularly heterogeneous chain, each portion comprising at least 5 wt% of the chain, differ in composition from •one another by at least 5 wt% ethylene. Unless other¬ wise indicated, this property of Intra-CD as referred to herein is based upon at least two 5 wt% portions of copolymer chain. The Intra-CD of copolymer in accor¬ dance with the present invention can be such that at least two portions of copolymer chain differ by at least 10 wt% ethylene. Differences of at least 20 wtZ, as well as of at least 40 wt% ethylene are also considered to be in accordance with the present invention. The experimental procedure for determining Intra-CD is as follows. First, the Inter-CD is estab¬ lished as described below, then the polymer chain is broken into fragments along its contour and the Inter-CD of the fragments is determined. The difference in the two results is due to Intra-CD as can be seen in the il¬ lustrative example below. Consider a heterogeneous sample polymer con¬ taining 30 monomer units. It consists of 3 molecules designated A, B, C. A EEEEPEEEPEEEPPEEPPEPPPEPPPPPPP B EEEEEPEEEPEEEPPEEEPPPEPPPEEPPP C EEPEEEPEEEPEEEPEEEPPEEPPPEEPPP Molecule A is 36.8 wt% ethylene, B is 46.6%,- and C is 50% ethylene. The average ethylene content for the mixture is 44.3%. For this sample the Inter-CD is such that the highest ethylene polymer contains 5.7% more ethylene than the average while the lowest ethylene content polymer contains 7.5% less ethylene than the av¬ erage. Or, in other words, 100 wt% of the polymer is within +5.7% and -7.5% ethylene about an average of 44.3%. Accordingly, the Inter-CD is 7.5% when the given wtZ of the polymer is 100%. The distribution may be represented graphically as by curve 1 in Figure 3. If the chains are broken into fragments, there will be a new Inter-CD. For simplicity, consider first breaking only molecule A into fragments shown by the slashes as follows: EEEEP/EEEPE/EEPPE/EPPEP/PPEPP/PPPPP Portions of 72.7%, 72.7%, 50%, 30.8%, 14.3% and 0% ethylene are obtained. If molecules B and C are simi¬ larly broken and the weight fractions of similar compo¬ sition are grouped the new Inter-CD shown by curve 2 in Figure 3 is obtained. The difference between the two curves in the figure is due to Intra-CD. Consideration of such data, especially near the end point ranges, demonstrates that for this sample at least 5% of the chain contour represented by the cu¬ mulative weight % range (a) differs in composition from another section by at least 15% ethylene shown as (b) , the difference between the two curves. The difference is composition represented by (b) cannot be intermolecu- lar. If it were, the separation process for the origi- • nal polymer would have revealed the higher ethylene con¬ tents seen only for the degraded chain. The compositional differences shown by (b) and (d) in the figure between original and fragmented chains give minimum values for Intra-CD. The Intra-CD must be at least that great, for chain sections have been isolated which are the given difference in composition (b) or (d) from the highest or lowest composition ' polymer isolated from the original. We know in this ex¬ ample that the original polymer represented at (b) had sections of 72.7% ethylene and 0% ethylene in* the same chain. It is highly likely that due to the inefficiency of the fractionation process any real polymer with Intra-CD examined will have sections of lower or higher ethylene connected along its contour than that shown by the end points of the fractionation of the original polymer. Thus, this procedure determines a lower bound for Intra-CD. To enhance .the ' detection, the original whole polymer can be fractionated (e.g., separate mole¬ cule A from molecule B from molecule C in the hypothet¬ ical example) with these fractions refractionated until they show no (or less) Inter-CD. Subsequent fragmenta¬ tion of this intermolecularly homogeneous fraction now reveals the total Intra-CD. In principle, for the exam¬ ple, if molecule A were' isolated, fragmented, fraction¬ ated and analyzed, the Intra-CD for the chain sections would be 72.7-0% = 72.7% rather than 72.7-50% = 22.7% seen by fractionating the whole mixture of molecules A, B and C. In order to determine the fraction of a polymer which is intramolecularly heterogeneous in a mixture of polymers combined from several sources or as several modes in the case described here, the mixture must be separated into fractions which show no further heterogenity upon subsequent fractionation. These fractions are subsequently fractured and fractionated to reveal which are heterogeneous. The fragments into which the original polymer is broken should be large enough to avoid end effects and to give a reasonable opportunity for the normal sta¬ tistical distribution of segments to form over a given monomer conversion range in the polymerization. In¬ tervals of c_a 5 wt% of the polymer are convenient. For example, at an average polymer molecular weight of about 10 , fragments of ca 5000 molecular weight are appropri¬ ate. A detailed mathematical analysis of plug flow or batch polymerization indicates that the rate of change of composition along the polymer chain contour will be most severe at high ethylene conversions near the end of the polymerization. The shortest fragments are needed here to show the low propylene content sections. The best available technique for determination of compositional dispersity for non-polar polymers is solvent/non-solvent fractionation which is based on the thermodynamics of phase separation. This technique is described in "Polymer Fractionation," M. Cantow editor, Academic 1967, p. 341 ff and in H. Inagaki, T. Tanaku, Developments in Polymer Characterization, 3_, 1. (1982). These are incorporated herein by reference. For non-crystalline copolymers of ethylene and propylene, molecular weight governs insolubility more than does composition in -a solvent/non-solvent solution. High molecular weight polymer is less soluble in a given solvent mix. Also, there is a systematic correlation of molecular weight with ethylene content for the polymers described herein. Since ethylene polymerizes much more rapidly than propylene, high ethylene polymer also tends to be high in molecular weight. Additionally, chains rich in ethylene tend to be. less soluble in hydrocar¬ bon/polar non-solvent mixtures than propylene-rich chains. Thus the high molecular weight, high ethylene chains are easily separated on the basis of thermodynam¬ ics. A fractionation procedure is as follows: Un- • fragmented polymer is dissolved in n-hexane at 23°C to form a a 1% solution (1 g polymer/100 cc hexane) . Isopropyl alcohol is titrated into the solution until turbidity appears at which time the precipitate is al¬ lowed to settle. The supernatant liquid is removed and the precipitate is dried by pressing between Mylar (polyethylene terphthala ' te) film at 150°C. Ethylene content is determined by ASTM method D-3900. Titration is resumed and subsequent fractions are recovered an an¬ alyzed until 100% of the polymer is collected. The titrations are ideally controlled to produce fractions of 5-10% by weight of the original polymer especially at the extremes of composition. To demonstrate the breadth of the distribu¬ tion, the data are plotted as % ethylene versus the cu¬ mulative weight of polymer as defined by the sum of half the weight % of the fraction of that composition plus the total weight Z of the previously collected frac¬ tions. Another portion of the original polymer is broken into fragments. A suitable method for doing this is by thermal degradation according to the following ' procedure: In a sealed container in a nitrogen-purged oven, a 2 mm thick layer of the polymer is heated for 60 minutes at 330°C. This ' should be adequate to reduce a 10 molecular weight polymer to fragments of c_a 5000 mo¬ lecular weight. Such degradation does not change the average ethylene content of the polymer. This polymer is fractionated by the same procedure as the high molec¬ ular weight precursor. Ethylene content is measured, as well as molecular weight on selected fractions. Ethylene content is measured by ASTM-D3900 for ethylene-propylene-copolymers between 35 and 85 wt% ethylene. Above 85% ASTM-D2238 can be used to obtain methyl group concentrations which are related to percent ethylene in an unambiguous manner for ethylene-propylene copolymers. When co onomers other than propylene are employed no ASTM tests covering a wide range of ethylene contents are available, however, proton and carbon 13 nuclear magnetic resonance can be employed to determine the composition of such polymers. These are absolute techniques requiring no calibration when operated such that all nucleii contribute equally to the spectra. For ranges not covered by the ASTM tests for ethylene-propy¬ lene copolymers, these nuclear magnetic resonance meth¬ ods can also- be used. Molecular weight and molecular weight distri¬ bution are measured using a Waters 150 gel permeation chromatograph equipped with a Chromatix KMX-6 on-line light scattering photometer. The system is used at 135°C with 1,2,4, trichlorobenzene as mobile phase. Showdex (Showa-Denko America, Inc.) polystyrene gel col¬ umns 802, 803, 804 and 805 are used. This technique is discussed in "Liquid Chromatography of Polymers and Related Materials III," J. Cazes editor. Marcel Dekker, 1981, p. 207 (incorporated herein by reference). No corrections for column spreading are employed; however, data on generally accepted standards, e.g., National Bu¬ reau of Standards Polyethene 1484 and anionically produced hydrogenated polyisoprenes (an alternating ethylene-propylene copolymer) demonstrate that such cor¬ rections on Mw/Mn or Mz/Mw are less than .05 unit. Mw/Mn is calculated from an elution time-molecular weight relationship whereas / is evaluated using the light scattering photometer. The numerical analyses can be performed using the commercially available computer sofϋwear GPC2 , M0LWT2 available form LDC/Milton Roy- Riviera Beach, Florida. Since the tubular reactor is the preferred re¬ actor system for carrying out processes in accordance with the present invention, the following illustrative descriptions and examples are drawn to that system, but will apply to other reactor systems as will readily oc¬ cur to those skilled in the art having the benefit of the present disclosure. In practicing processes in accordance with the present invention, use is preferably made of at least one tubular reactor. Thus, in its simplest form, such a process would make use of but a single reactor. Howev¬ er, more than one reactor can be used, either in paral¬ lel, or in series with multiple monomer feeds. For example, various structures can be pre¬ pared by adding additional monomer (s) during the course of the polymerization, as shown in Fig. 4, wherein com¬ position is plotted versus position along the contour length of a polymer chain. The structure shown in curve 1 is obtained by feeding all of the monomers to the tu¬ bular reactor inlet or at the start of a batch reaction. In comparison, the structure depicted in curve 2 can be made by adding additional ethylene at a point along the tube or at a time in a batch reactor, where the chains have reached about half their length. Curve 3 requires multiple feed additions. The structure depicted by curve 4 can be formed if additional comonomer rather than ethylene is added. This structure permits a whole 'ethylene composition range to be omitted from the chain. In each case, a third or more comonomers may be added. The composition of the catalyst used to pro¬ duce alpha-olefin copolymers has a profound effect on ccpolymer product properties such as compositional *sr dispersity and MWD. The catalyst utilized in practicing processes in accordance with the present invention should be such as to yield a controlled number of active species, each of which must be capable of simultaneous initiation of chains and must minimize chain transfer. Each active catalyst species generated either by multi¬ ple catalyst feeds or by a single catalyst feed that generates multiple active species must produce copolymer product in accordance with the present invention, e.g. , a copolymer of narrow MWD. The extent to which a cata¬ lyst species contributes to the polymerization can be readily determined using the below described techniques for characterizing catalyst according to the number of active catalyst species. Techniques for characterizing catalyst accord¬ ing to the number of active catalyst species are within the skill of the art, as evidenced by an article enti¬ tled "Ethylene-Propylene Copolymers. Reactivity Ratio, Evaluation and Significance," C. Cozewith 'and G. Ver Strate, Macromolecules, 4, 482 (1971), which is incor¬ porated herein by reference. It is disclosed by the authors that copolymers made in a continuous flow stirred reactor (CFSTR) should have an MWD characterized by Mw/Mn=2 and a narrow inter- molecular compositional distribution when one active catalyst species is present. By a combination of frac¬ tionation and gel permeation chromatography (GPC) it is shown that for single active species catalysts the com¬ positions of the fractions vary no more than ±3% about the average and the MWD (weight to number average ratio) for these samples approaches two (2) . It is this latter characteristic (Mw/Mn of about 2) that is deemed the more important in identifying a single active catalyst species. On the other hand, other catalysts gave copolymer with an compositional variation greater than ±10% about the average and multi-modal MWD often with M../ greater than 10. These other catalysts are deemed to have more than one active species . Catalyst systems to be used in carrying out processes in accordance with the present invention may be Ziegler catalysts , which may typically include compo¬ nents selected from: (a) a compound of a transition metal , i. e . , a metal of Groups I-B , III-B, IVB , VB , VIB , VIIB and VIII of the Periodic Table , and (b) an organometal compound of a metal of Groups I-A, II-A, II-B and III-A of the • Periodic Table. The preferred catalyst system in practicing processes in accordance with the present invention com¬ prises hydrocarbon-soluble vanadium compound in which the vanadium valence is 3 to 5 and organo-aluminu com- pcund , with the provision that the catalyst system yields one active catalyst species which has the ca¬ pability to produce narrow MWD copolymers as described ' above . At least one of the vanadium compound/ organo- aluminum pair selected must also contain a valence- bonded halogen. In terms of formulas , vanadium compounds use¬ ful in practicing processes in accordance with the pre¬ sent invention could be : (I ) V0C1 x ° R) 3 _ x where x = 0-3 and R = a hydrocarbon radical; (II) VC1 4 ; (III) V0(AcAc) 2 , where AcAc = acetyl acetonate; (IV) V(AcAc) 3 ; (V) VOCl χ (AcAc) 3 _ χ , where x = 1 or 2; and (VI) VCl 3 .nB, Where n - 2-3 and B = Lewis base capable of making hydrocarbon-soluble complexes with VCl.,, such as tetrahydrofuran, 2-methyl-tetrahydrofuran and dimethyl pyridine. In formula I above, R preferably represents a C, to C, 0 aliphatic, alicyclic or aromatic hydrocarbon radical such as ethyl (Et) , phenyl, isopropyl, butyl, propyl, n-butyl, i-butyl, t-butyl, hexyl, cyclohexyl, octyl, naphthyl, etc. Non-limiting, illustrative exam¬ ples of formula (1) and (2) compounds are vanadyl tri- halides, alkoxy halides and alkoxides such as VOCl , V0Cl 2 (0Bu) where Bu = butyl, and VO(OC 2 H 5 ) 3 . The most preferred vanadium compounds are VCl,, VOCl-, and V0C1 2 (0R). As already noted, the co-catalyst is pref¬ erably organo-aluminum compound. In terms of chemical formulas, these compounds could be as follows: A1R 3 , A1(0R')R 2 , A1R 2 C1, R 2 Al-0-AlR' 2 , AlR'RCl A1R 2 I; A1 2 R 3 C1 3 A1RC1 2 , and mixtures thereof where R and R' represent hydro¬ carbon radicals, the same or different, as described above with respect to the vanadium compound formula. The most preferred organo-aluminum compound is an alumi¬ num alkyl sesquichloride such as Al^Et^Cl- or Al 2 (iBu)~- Cl,. In one embodiment of the invention the aluminum compound can be described by the formula A R n X3_ n where R is as previously defined, X is halogen, preferably chlorine and n can vary from 1 to 2. When catalysts are desired that produce a sin¬ gle active species, catalysts comprised of V0C1- or VCl, with Al ^ R^Cl^, preferably where R is ethyl, have been shewn to be particularly effective. For best catalyst performance, the molar amounts of catalyst components added to the reaction mixture should provide a molar ra¬ tio of aluminum/vanadium (Al/V) of at least about 2. The preferred minimum Al/V is about 4. The maximum Al/V is based primarily on the considerations of catalyst ex¬ pense and the desire to minimize the amount of chain transfer that may be caused by the organo-aluminum com¬ pound (as explained in detail below). Since, as is known certain organo-aluminum compounds act as chain transfer agents, if too much is present in the reaction mixture .the Mw/Mn of the copolymer may rise above 2. Based on these considerations, the maximum Al/V can be about 25, however, a maximum of about 17 is more pre¬ ferred. The most preferred maximum is about 15. Chain transfer agents for the Ziegler-catalyz- ed polymerization of alpha-olefins are well known and are illustrated, by way of example, by hydrogen or diethyl zinc for the production of EPM and EPDM. Such agents are very commonly used to control the molecular, weight of EPM and EPDM produced in continuous ' flow stirred reactors. For the essentially single active species Ziegler catalyst systems used in accordance with the present invention, addition of chain transfer agents to a CFSTR reduces the polymer molecular weight but does not affect the molecular weight distribution. On the other hand, chain transfer reactions during tubular re¬ actor polymerization in accordance with the present in¬ vention broaden polymer molecular weight distribution. Thus the presence of chain transfer agents in the re¬ action mixture should be minimized or omitted altogeth¬ er. Although difficult to generalize for all possible reactions, the amount of chain transfer agent used should be limited to those amounts that provide copoly¬ mer product in accordance with the desired limits as re¬ gards MWD and compositional dispersity. It is believed that the maximum amount. of chain transfer agent present in the reaction mixture could be as high as about 0.2 mol/mol of transition metal, e.g., vanadium, again provided that the resulting copolymer product is in ac¬ cordance with the desired limits as regards MWD and com¬ positional dispersity. Even in the absence of added chain transfer agent, chain transfer reactions can occur because propylene and organo-aluminum cocatalyst can al¬ so act as chain transfer agents. In general, among the organo-aluminum compounds that in combination with the vanadium compound yield just one active species, the organo-aluminum compound that gives the highest copoly¬ mer molecular weight at acceptable catalyst activity should be chosen. Furthermore, if the Al/V ratio has an effect on the molecular weight of copolymer product, that Al/V should be used which gives the highest molecu¬ lar weight also at acceptable catalyst activity. Chain transfer with propylene can best be limited by avoiding excessive temperature during the polymerization as de¬ scribed below. Molecular weight distribution is also- broadened by catalyst deactivation during the course of the polymerization which leads to termination of growing chains. It is well known that the vanadium-based Zieg¬ ler catalysts used in accordance with the present inven¬ tion are subject to such deactivation reactions which depend to an extent upon the composition of the cata¬ lyst. Although the relationship between active catalyst lifetime and catalyst system composition is not known at present, for any given catalyst, deactivation can be reduced by using the shortest residence time and lowest temperature in the reactor that will produce the desired monomer conversions. Polymerizations in accordance with the present invention should be conducted in such a manner and under conditions sufficient to initiate propagation of essen¬ tially all copolymer chains for each particular catalyst species simultaneously. This can be accomplished by utilizing the process steps and conditions described be¬ low. The catalys t components are preferably pre- ixe d , that is , reacted to form active ca ta lyst outside of the reac tor , to ensure rapid chain initiation . Aging of the premixed catalyst system , that is , the time spent by the catalys t components ( e . g . , vanadium compound and er εno aluminum) in contact with one another outside of the reactor , must be kept within certain l imits . If not aged for a sufficient period of time , the components will not have reacted with each other sufficiently to yield an adequate quantity of active ca talyst species , with the result of continued catalyst species formation in the reactor , resulting in non-simultaneour chain ini¬ tiation . Also , it is known that the activity of the catalys t species will decreas e with time so that the ag¬ ing mus t be kept below a maximum limit . The minimum ag¬ ing period , depending on such factors as concentration of catalys t components , temperature and mixing equip¬ ment , can be as low as about 0. 1 second . The maximum aging period is that period of aging after which the catalyst species has been deactivated to the 'point where it cannot effectively be used in the polymerization pro¬ cess . In practice there is no appreciable advantage in allowing the catalyst to age longer than a time sufficient to fully react all of the available catalyst components thereby generating all of the active catalyst species whic will be available for polymerization. Generally, the agin time will ordinarily be about 0.1 seconds to about 200 seconds or even longer, usually about 0.5 seconds to 100 seconds, preferably about 1 second to 50 seconds. The premixing performed at low temperature such as 40 C or below. It is preferred that the mixing be performed at 25°C or below, with 15 C or below being most preferred x Where more than one catalyst is combined into a single catalyst feed stream, each catalyst and cocatalyst can be premixed separately. The several pre- mixed streams of catalysts species are then combined and fed to the reactor. Alternately, the several pre-mixed catalyst feed streams can be fed separately to different points along the reactor. The temperature of the reaction mixture should also be kept with certain limits. The temperature at the reactor inlet should be high enough to provide com¬ plete, rapid chain initiation at the start of the poly¬ merization reaction. The length of time the reaction mixture spends at high temperature must be short enought to minimize the amount of undesirable chain transfer and catalyst deactivation reactions. Temperature control of the reaction mixture is complicated somewhat by the fact that the polymerization reaction generates large quantities of heat. This prob¬ lem is, preferably, taken care of by using prechilled feed to the reactor to absorb the heat of polymeriza-- tion. With this technique, the reactor is operated adiabatically and the temperature is allowed to increase during the course of polymerization. As an alternative to feed prechill, heat can be removed from the reaction mixture, for example, by a heat exchanger surrounding at least a portion of the reactor or by well-known autore- frigeration techniques in the case of batch reactors or multiple stirred reactors in series. Where an adiabatic reactor operation is used, the inlet temperature of the reactor feed can be about -80°C to about 50°C. The outlet temperature of the re¬ action mixture can be as high as about 200°C. The pre¬ ferred maximum outlet temperature is about 70°C. The most preferred maximum is about 50°C. In the absence of reactor cooling, such as by a cooling jacket, to remove the heat of polymerization, the temperature of the re¬ action mixture will increase from reactor inlet to out¬ let by an amount dependent upon the heat of polymeriza¬ tion, reaction mixture specific heat and the percent of copolymer in the reaction mixture (weight of copolymer per weight of solvent). For ethylene-propylene copoly¬ merization in hexane the temperature rise is about 13°C per weight percent of copolymer. Having the benefit of the above disclosure, those skilled in the art can determine the operating temperature conditions for making copolymer in accor¬ dance with the present invention. For example, assume an adiabatic reactor and an outlet temperature of 35°C are desired for an ethylene-propylene reaction mixture in hexane containing 5% copolymer. The reaction mixture will increase in temperature by about 13°C for each weight percent copolymer or 5 weight percent x 13°C/wt% = 65°C. To maintain an outlet temperature of 35°C, it will thus require a feed that has been prechilled to 35°C-65°C = -30°C. In the instance that external cool¬ ing is used to absorb the heat of polymerization, the feed inlet temperature could be higher with the other, temperature constraints described above otherwise being applicable. Because of heat removal and reactor tempera¬ ture limitations, the preferred maximum copolymer con¬ centration at the reactor outlet when this is the only stream drawn from the reactor is 25 wt/100 wt diluent. The most preferred maximum concentration is 15 wt/100 wt. When multiple streams of reaction mixture are with¬ drawn from the reactor ' and each part of the reaction mixture withdrawn is blended with other parts of re¬ action mixture withdrawn, the blend so formed has a pre¬ ferred maximum copolymer concentration of about 25 wt./lOO wt. of diluent. The most preferred maximum is 15 wt./lOO wt. diluent. In the case of either single or multiple product stream withdrawal, there is no lower limit to concentration due to reactor operability, but for economic reasons it.is preferred to have a copolymer concentration of at least 2 wt/100 wt. Most preferred is a concentration of at least 3 wt/100 wt. The rate of flow of the reaction mixture through the reactor should be high enough to provide good mixing of the reactants in the radial direction and minimize mixing in the axial direction. Good radial mixing is beneficial to minimize radial temperature gra¬ dients due to the heat generated by the polymerization reaction. Radial temperature gradients will tend to broaden the molecular weight distribution of the copoly¬ mer since the polymerization rate is faster in the high temperature regions resulting from poor heat dissipa¬ tion. The artisan will recognize that achievement of these objectives is difficult in the case of highly vis¬ cous solutions. This problem can be overcome to some extent through the use of radial mixing devices such as static mixers (e.g., these produced by the Kenics Corpo¬ ration) . Residence time of the reaction mixture in the mix-free reactor can vary over a wide range. The mini-, mum can be .as low as about 1 second. A preferred mini¬ mum is about 10 seconds. The most preferred minimum is about 15 seconds. The maximum can be as high as about 3600 seconds. A preferred maximum is about 1800 sec¬ onds. The most preferred maximum is about 900 seconds. With reference to the accompanying drawings, particularly Fig 1, reference numeral 1 refers to a pre- tnixing device for premixing the catalyst components. For purposes of illustration, it is assumed that a copolymer of ethylene and propylene (EPM) is to be pro¬ duced using as catalyst components vanadium tetrachlo- ride and ethyl aluminum sesquichloride. The polymeriza¬ tion is an adiabatic, solution polymerization process using hexane solvent for both the catalyst sy ' stem and the reaction mixture. The premixing device _1 comprises a temperature control bath 2, a fluid flow conduit 3_ and mixing device _4 (e.g., a mixing tee). To mixing device __ are fed hexane solvent, vanadium tetrachloride and ethyl aluminum sesqui chloride through feed conduits 5_, 6_ and 1_, respectively. Upon being mixed in mixing device ^, the resulting catalyst mixture is caused to flow within conduit 3_ » optionally in the form of a coiled tube, for a time long enough to produce the active catalyst spe¬ cies at the temperature set by the temperature bath. The temperature of the bath is set to give the desired catalyst solution temperature in conduit 3_ at the outlet of the bath. Upon leaving the premixing device, the cata¬ lyst solution flows through conduit 8_ into mixing zone __ to provide an intimate mixing with hexane solvent and reactants (ethylene and propylene) which are fed through conduit 1_0. Any suitable mixing device can be used, such as a mechanical mixer, orifice mixer or mixing tee. For economic reasons, the mixing tee is preferred. The residence time of the reaction mixture in mixing zone __ is kept short enough to prevent significant polymer for-, mation therein before being fed through conduit ^1_ to tubular reactor 12. Alternatively, streams 8 ^ and 1_0 can be fed directly to the inlet of reactor 12_ if the flow rates are high enough to accomplish the desired level of intimate mixing. The hexane- with dissolved monomers may be cooled upstream of mixing zone 9_ to proviGe the desired feed temperature at the reactor inlet. The tubular reactor is shown with optional feed and take off points. Where the catalyst comprises only a single polymer species one or more take off points, 1_3, are used to withdraw polymer fractions at different points along the polymerization path. In or¬ der to maintain constant flow, additional solvent may be added to make up the volume of material withdrawn. Ad¬ ditional catalyst and monomer can be introduced through line, JL4_, or line, 15. The polymer withdrawn through line, 13, is combined with all other fractions withdrawn and collected with the reactor effluent for deashing and finishing. Where more than one catalyst species is used, multiple premixing devices, _1, are used. The mixed cat¬ alyst can be directed to mixing zone, _9, for mixing with additional catalyst species and monomer or the effluent from the premixing devices can be combined prior to the mixing zone. Where a mixture of VCl, and V0C1- is used as the catalyst species in conjunction with ethylaluminum sesquichloride (EASC) , the molar ratio of VCl,/V0C1- can be about 0.01 to about 100, more preferably about 0.1 to about 10, most preferably about 0.5 to about 5. The amount of the total polymer and the molecular weight of each component will be determined by the ratio and the feed locations and take off points along the reactor. The molar ratio of alkyl aluminum sesquihalide to vanadium components (VCl, plus VOC1,) can be about 1 to about 40, preferably about 2 to about 40, more pref¬ erably about 4 to about 20, most preferably about 4 to. about 10, e.g., about 5 to about 10. The alkyl group of the sesquihalide is preferably a C,-Cg alkyl group, preferably ethyl. The halide can be bromine, chlorine or iodine, preferably chlorine. The preferred aluminum co-catalyst is ethylaluminum sesquichloride (EASC). In this system the two independent, non-interacting, mu¬ tually compatible catalyst systems are VCl, /EASC and V0C1 3 /EASC. In a preferred embodiment, a Lewis base moder¬ ator is incorporated into the catalyst system. The molar ratio of base to vanadium can be about 0 to about 5/1, preferably about 0.5/1 to about 2/1, more pref¬ erably about 1/1 to about 1.5/1. Illustrative, non- limiting examples of Lewis bases suitable for use in the practice of this invention are NH, , phenol, cyclohexa- none , tetrahydrofuran, acetylacetone, ethyl silicate and tri-n-butyl-phosphate. The Lewis base suppresses some long chain branching reactions when EPDM terpolymers are prepared. The polymer derived from the process of this invention is deashed and finished using conventional methods. Where the polymodal MWD is achieved by with¬ drawing product and different points or times from the reactor, the polymer streams are preferably blended and a single deashing and finishing process used. The re¬ sult is a thoroughly mixed, homogeneous polymer blend. Alternately, each process stream can be finished inde¬ pendently and combined by mechanical mixing. Having thus described the above illustrative reactor system, it will readily occur to the artisan that many variations can be made within the scope of the present invention. For example, the placement and num¬ ber of multiple feed sites, the choice of temperature profile during polymerization and the concentrations of reactants can be varied to suit the end-use application. By practicing processes in accordance with the present invention, ethylene-alpha-olefin copolymers hav¬ ing polymodal MWD with each molecular weight fraction having very narrow MWD can be made by direct polymeri¬ zation. Although narrow MWD copolymers can be made us¬ ing other known techniques, such as by fractionation or mechanical degradation, these techniques are considered to be impractical to the extent of being unsuitable for commercial-scale operation. With respect to EPDM made in accordance with the present invention, the products have enhanced cure properties at a given Mooney Viscosi¬ ty. Where the polymodal molecular weight distribu¬ tion is achieved by withdrawing polymer fractions from the reactor, it will be evident from reference to this disclosure that it is critical when or where polymer is withdrawn from the reaction zone. This can be deter¬ mined without undue experimentation. For example, a pi¬ lot plant scale tubular reactor can be equipped with a multiplicity of take off points. Ey running the reactor and withdrawing polymer samples from the system, molecular weight of the polymer at points along the re¬ actor can be determined. By converting the distance along the tube to time of reaction after introduction of catalyst, a plot can be made of molecular weight as a function of re¬ action time for a given catalyst/monomer/solvent system. The molecular weight/reaction time plot can be used to position take off points. For flexibility in selecting the product characteristics of a particular polymodal MWD product, a multiplicity of take off points can be installed, not all of which will be used in preparing a particular product with predetermined specifications. Similarly, inlet ports can be located at dif¬ ferent locations for the introduction of additional mcno er or catalyst streams. By introducing fresh catalyst and monomer downstream of the inlet, the MWD of the polymer will be modified. SO long as the polymer-- ization is carried out in this manner the polymer will be a polymodal MWD polymer of narrow MWD modes . Similar results are achieved by introducing fresh premixed catalyst with the additional monomer feed. It will be evident from this disclosure to those skilled in the art that the polymodal MWD polymers of this invention can be prepared by blending the prod¬ uct of runs prepared under different conditions or using different catalyst. For example, one polymerization can be conducted using VCl, /EASC as the catalyst and another conducted using VOCI ^ /EASC as • the catalyst. The product of the two runs can then be blended to form a bimodal MWD polymer blend. Other variations can be used to gen¬ erate polymer species of different M to prepare poly- modal MWD compositions. The advantages of the instant invention may be mere readily appreciated by reference to the following examples. Example I This example illustrates the method of this invention for preparing an EPM wherein polymer product is removed from the reactor at a point intermediate be¬ tween the reactor inlet and outlet. The polymerization was conducted in a 3/8 in. diameter tube and the resi¬ dence time in the reactor was 30 seconds. A take off port was located downstream of the inlet at a distance equivalent to 1 second residence time. Hexane was used as the solvent, VCl, as the catalyst, and Al 2 Et 3 Cl 3 as the cocatalyst. Hexane is purified prior to use by passing over 4A molecular sieves (Union Carbide, Linde Div. 4A 1/16" pellets) and silica gel (W.R. Grace Co. , Davidson Chemical Div. , PA- 400 20-4 mesh) to remove polar impurities which act as catalyst poisons. Gaseous, ethylene and propylene is passed over hot (270°C) CuO (Harshaw Chemical Co., CO1900 %" spheres) to remove oxygen followed by molecu¬ lar sieve treatment for water removal and then combined with hexane upstream of the reactor and passed through a chiller which provided a low enough temperature to com¬ pletely dissolve the monomers in the hexane. A catalyst solution is prepared by dissolving 18.5 g of vanadium tetrachloride, VCl,, in 5.0 1. of pu¬ rified n-hexane. The cocatalyst consists of 142 g of ethylaluminum sesquichloride, Al- p Et-Cl- , in 5.0 1. of purified hexane. The two solutions are pre ixed at 10°C and aged for 8 seconds. Typical feed rates and reacting conditions are shown in Table I. TABLE I Reactor Inlet Temperature ( β C) -10 Reactor Outlet Temperature (°C) 0 Reactor Feed Rates Hexane (Kg/hr) 60.3 Ethylene (kg/hr) 0.22 Propylene (kg/hr) 2.0 VC1 4 (g/hr) 2.22 Al 2 Et 3 Cl 3 (g/hr) 17 Catalyst Premixing Temperature (°C) 0 Catalyst Premixing Time ( s ec) 8 otal Reactor Residence Time ( sec ) 30 A product stream is withdrawn from the take off port at about 17 kg/hr and blended with effluent frc the reactor outlet. Approximately 20 wt% of the poly er in the effluent came from the take off port.- The molecular weight of the product from the take off pert is about one-half of that from the reactor outlet with a similar MWD (M^./t^ = 1.4, z / w = 1.3). The product is deashed and stripped. The resulting polymer is a bimodal MWD EPM with a theoretical _/M = 1.96 and M 2 /M w = 1.46. Example II Example I is repeated except that no effluent iε taken from the take off port and two reactors in par¬ allel are used. The feed rates listed in Table 1 are split so that 17 kg./hr are passed through the reactor with one second resi¬ dence time, and the remaining feed goes to the other reactor. The residence times in these two reactors are 1 and 30 seconds, respect¬ ively. Otherwise all conditions are the same as in Example I. The effluents frαn the reactor outlets are blended. After steady state is achieved, the blend is deashed, washed and stripped of solvent. The resulting polymer is a bimodal MWD EPM with a theoretical MWD as in Example I. Example III Example I is repeated except that no effluent is taken from the take off port and VOC1-/EASC is used as an additional catalyst. The second catalyst solution is prepared by dissolving 18.5g of V0C1- in 5.0 1. of purified hexane. The cocatalyst consists of 142g of Al 2 Et 3 Cl 3 in 5.0 1. of purified hexane. The VCl, and V0C1 3 are blended with cocatalysts in separate premixing units and aged for ten seconds. The two premixed catalyst streams are then . mixed with the monomer/ hexane stream and fed into the reactor. Reactor residence time is 50 seconds. Other¬ wise all conditions are the same as in Example I. After steady state is achieved, the reactor effluent is de¬ ashed, washed and stripped of solvent. The resulting polymer is a bimodal MWD EPM. Example IV Example I is repeated except that no effluent is taken from the take off port. The catalyst system used is vanadium oxy richloride (V0C1 and diethyl- al-__minum chloride (AlEt 2 Cl). Otherwise all conditions are the same as in Example I. This catalyst system pro¬ duces at least two independent catalyst species, each of -.,_-.ich initiates a separate MWD mode. After steady state is achieved, the_reactor effluent is deashed, washed and stripped of solvent. The resulting polymer is a poly¬ modal MWD EPM. Example V " • Example I is repeated except that no take off port effluent is collected and the catalyst and feed •streams are split. About 2/3 of the monomer/hexane stream and 2/3 of the premixed catalyst are mixed and fed to the reactor inlet and the remaining 1/3 of the mcnomer/hexane feed is mixed with the remaining catalyst stream and fed into the reactor at a point midway be¬ tween the reactor inlet and outlet. The EPM product is a polymodal MWD polymer. Example VI Example I is repeated except that no effluent is taken from the take off port and a catalyst reactiva¬ tor is used. The catalyst reactivator solution is pre¬ pared by dissolving 30.5g of butyl perchlorocrotonate in 3.0 1 of purified hexane. This solution is fed into the reactor, at 3.6 g/hr along with 50 g/hr of ethylene, at a point midway between the reactor inlet and outlet. Otherwise all conditions are the same as in Example I. After steady state is achieved, the effluent is deashed, washed and stripped of solvent. The resulting product is a polymodal MWD EPM. It will be appreciated by those skilled in the. art who have reference to this disclosure that where reference is made to the beginning of polymerization, in a continuous process, this is intended to mean the time at which catalyst is introduced. Similarly, the end of the polymerization in a tubular reactor means at the point where the polymerizationis terminated. Where reference is made to blends being made by combining product or reaction mixtures withdrawn from the reactor at one or more times after the start of polymerization with product from the "reactor outlet" or "completion of polymerization" this language is intended to include the last product or reaction mixture with¬ drawn from the reactor for the purpose of forming the blend whether or not the last product or reaction mix¬ ture is obtained from the physical reactor outlet or at the. actual completion of polymerization, notwithstanding the fact that product from the actual reactor outlet or actual completion of polymerization is used for some purpose other than blending with fractions of polymer withdrawn.

Claims: WHAT IS CLAIMED IS: 1. In a polymerization process for producing copolymer from a reaction mixture comprised of catalyst and a monomer feed comprising ethylene, at least one other alpha-olefin monomer and, optionally, a non-con¬ jugated diene, the improvement which comprises producing a polymodal MWD copolymer by conducting the polymeriza¬ tion: (a) in at least one reactor, said reactor be¬ ing a substantially mix free reactor; (b) with essentially one active catalyst spe¬ cies; (c) using at least one reaction mixture which is essentially transfer-agent free; (d) in such a manner and under conditions suf¬ ficient to initiate propagation of essentially all copolymer chains simultaneously; (e) withdrawing a part of the reaction mixture- containing copolymer from the reactor at, at least two predetermined times after the start of polymerization; and (f) blending the polymer withdrawn at each such predetermined' time; thereby producing a polymodal MWD copolymer comprising at least two different molecular weight modes where¬ in each mode has a narrow MWD and at least one of two characteristics, (1) an M /M of less than 2 and (2) 2. The process according to claim 1 wherein the reactor comprises a tubular reactor having a multi¬ plicity of take off ports. 3. The process according to claim 2 wherein the polymer from said take off port and reactor outlet are blended by combining the reaction mixtures collected, and subsequently recovering the polymer from the combined reaction mixture. 4. The process according to claim 1 wherein the catalyst comprises a Ziegler catalyst. 5. The process according to claim 4 wherein the catalyst comprises a hydrocarbon-soluble vanadium compound and an organo-aluminum compound which react to form essentially one active catalyst species, at least one of the vanadium compound and organo-aluminum com¬ pound containing a valence-bonded halogen. 6. The process according to claim 1 wherein the temperature of the reaction mixture at the ini¬ tiation of polymerization is about -80°C to 50°C. 7. The process according to claim 1 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 8. The process according to claim 4 wherein the. polymerization is a solution polymerization. 9. The process according to claim 4 wherein the catalyst components are premixed. 10. The process according to claim 9 wherein the premixed catalyst components are aged for at least 0.5 seconds. 11. The process according to claim 5 wherein the mole ratio of aluminum to vanadium in the catalyst is about 2 to 25. 12. The process according to claim 1 wherein the polymerization is conducted in a solvent for the reaction mixture; each part of the reaction mixture withdrawn being blended with other parts withdrawn; the blend so formed having a copolymer concentration of about 3 to about 15% on a weight copolymer per weight of solvent basis. 13. The process according to claim 1 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 50°C. 14. The process according to claim 9 wherein the catalyst comprises components that are premixed and then aged for about 1 to 50 seconds. 15. The process according to claim 5 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 16. The process according to claim 11 wherein the polymerization is conducted in a solvent for the re¬ action mixture, and wherein each part of the reaction mixture withdrawn from the reactor is blended with other parts withdrawn, and the blend so formed has a copolymer concentration of about 3% to 10% on a weight of polymer per weight of solvent basis. 17. The process according to claim 5 wherein the catalyst comprises: (a) hydrocarbon-soluble vanadium compound se¬ lected from the group consisting of: V0Cl χ (0R) 3 . χ , where x=0-3 and R=hydrocarbon radical; vcι 4 , V0(AcAc) 2 , where AcAc=acetyl acetonate V(AcAc) 3 , where AcAc=acetyl acetonate V0Cl χ (AcAc) 3 _ χ , where x=l or 2 and AcAc=acetyl acetonate, and VCl 3 .nB, where n=2 to 3 and B=Lewis base capable of forming hydrocarbon-soluble complexes with VC1 3 ; and (b) an organo-aluminum compound selected from the group consisting of: A1R 3 A1R 2 C1, A1 2 R 3 CL 3 , A1RC1 2 , AlR'RCl, A1(0R')R 2 , R 2 A1-0A1R' 2 , AlP 2 I and mixtures thereof, where R and R' are hydrocarbon radicals. 18. The process according to claim 5 wherein the catalyst comprises VCl, and A1 2 R,C1 3 wherein R is a hydrocarbyl moiety. 19. The process according to claim 1 wherein the temperature of the reaction mixture at the ' comple¬ tion of polymerization is about 70°C. 20. The process according to claim 1 wherein the polymerization is adiabatic. 21. The process according to claim 1, which " is continuous and is conducted in hexane solvent. 22. The process according to claim 1 wherein said polymerization is conducted in at least one tubular reactor. 23. The process according to claim 22 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha- olefin monomer and diene are fed to said tubular reactor at multiple feed sites. 24. The process according to claim 18 wherein R is ethyl. 25. The product prepared according to the process of claim 1. 26. The product according to claim 25 wherein said copolymer product is cured. 27. The product according to claim 25 wherein said copolymer product is blended with basestock lubri¬ cating oil. 28. The product according to claim 27 wherein said copolymer product is blended with the basestock lu¬ bricating oil in an amount from about .001 to 49 wtZ. copolymer based on oil plus copolymer. 29. A method for preparing a polymodal MWD .ethylene copolymer which comprises: (a) conducting the polymerization in a sub¬ stantially mix free reactor; (b) using at least two catalysts, ach of which initiates growth of polymer chains that attain a different average molecular weight than that initiated by the other ca talys t ; (c) using at least one reaction mixture com¬ prising ethylene , at least one alpha-olefin monomer and , optionally , a non-conjugated diene , said reaction mixture being essentially trans fer-agent free (d) in such a manner and under such conditions sufficient to initiate propagation of essen¬ tially all copolymer chains made by a particu¬ lar catalyst species simultaneously ; thereby producing a polymodal MWD ethylene copolymer comprising at least two different molecular weight modes wherein each mode having a narrow MWD and at least one of two characteristics , (1 ) an M /M of less than 2 and (2 ) of less than 1 . 8 . 30. The process according to claim 29 wherein the catalyst comprises a Ziegler catalyst . 31. The process according to claim 29 wherein each catalyst comprises a hydrocarbon-solub le vanadium ccrpound and an organo-aluminum compound which react to form essentially one active catalyst species , at least one of the vanadium compound and organo a luminum com¬ pound containing a valence-bonded halogen. 32. The process according to claim 31 wherein each catalyst comprises : (a) hydrocarbon-soluble vanadium compound se¬ lected from the group consisting of : VOCl χ (OR) 3 . χ . where x=0 to 3 and R=hydrocarbon radical; VC1 A ; VO (AcAc) 2 , where AcAc=acetyl acetonate ; V(AcAc) 3 where AcAc=acetyl acetonate; V0Cl χ (AcAc) 3 _ χ where x=l or 2 and AcAc=acetyl acetonate ; and VCl 3 . nB , where n=2 to 3 and B=Lewis base capable of forming hydrocarbon-soluble complexes with VC1 3 ; and (b ) organo-aluminum compound selected from the group consisting of : A1R 3 A1R 2 C1, A1 2 R 3 CL 3 , A1RC1 2 , AlR'RCl, A1(0R')R 2 , R 2 A1-0A1R* 2 , AlR I and mixtures thereof, where R and R' are hydrocarbon radicals. 33. The process according to claim 32 wherein a first catalyst comprises VCl, and A1 2 R 3 C1~; and a sec¬ ond catalyst comprises V0C1 3 and Al 2 R',Cl 3 where R and R 1 are the same or different hydrocarbyl moiety. 34. The process according to claim 33 wherein R and R' are ethyl. 35. The process according to claim 29 wherein the reactor is a tubular reactor. 36. The process according to claim 29 wherein the temperature of the reaction mixture at the initia¬ tion of polymerization is about -80°C to 50°C. 37. The process according to claim 29 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 38. The process according to claim 32 wherein the polymerization is a solution polymerization. 39. The process according to claim 30 wherein the catalyst components are premixed. 40. The process according to claim 31 wherein the mole ratio of aluminum to vanadium in the catalyst is about 2 to 25. 41. The process according to claim 39 wherein the catalyst components are premixed and then aged for at least 0.5 seconds. 42. The process according to claim 38 wherein the polymerization is conducted in a solvent for the re¬ action mixture wherein the copolymer concentration in the reaction mixture at the completion of polymerization is about 3 to about 15% on a weight copolymer per weight of solvent basis. 43. The process according to claim 29 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 50°C. 44. The process according to claim 39 wherein the catalyst comprises components that are premixed and then aged for about 1 to 50 seconds. 45. The process according to claim 38 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 46. The process according to claim 45 wherein the polymerization is conducted in a solvent for the re¬ action mixture, and wherein the copolymer concentration in the reaction mixture at the completion of polymeriza¬ tion is about 3% to 10% on a weight of polymer per weight of solvent basis. 47. The process according to claim 29 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 70°C. 48. The process according to claim 29 wherein the polymerization is adiabatic. 49. The process according to claim 29 wherein the polymerization is continuous and is conducted in hexane solvent. 50. The process according to claim 49 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha- olefin monomer and diene are fed to said tubular reactor at multiple feed sites. 51. In a polymerization process for producing copolymer from a reaction mixture comprised of catalyst and a monomer feed comprising ethylene, at least one other alpha-olefin monomer, and optionally, at least one non-conjugated diene, the improvement which comprises producing a polymodal MWD copolymer by conducting the polymerization: (a) in at least two reactors, said reactors each being a substantially mix free; (b) with essentially one active catalyst spe¬ cies in each reactor; (c) using at least one reaction mixture in each reactor which is essentially transfer- agent free in each reactor; (d) in such a manner and under conditions suf¬ ficient to initiate propagation of essentially all copolymer chains simultaneously; (e) blending the polymers from each re¬ actor; and (f) recovering the blended polymers; thereby producing a polymodal MWD ethylene copolymer comprising at least two different molecular weight modes wherein each mode having a narrow MWD and at least one of two characteristics, (1) an M w /M n of less than 2 and and Z /M., of less than 1.8. 52. The process according to claim 51 wherein- the catalyst comprises a Ziegler catalyst. 53. The process according to claim 52 wherein each catalyst species comprises a hydrocarbon-soluble vanadium compound and an organo-aluminum compound which react to form essentially one active catalyst species, at least one of the vanadium compound and organo alumi¬ num compound containing a valence-bonded halogen. 54. The process according to claim 53 wherein each catalyst comprises: (a) hydrocarbon-soluble vanadium compound se- lected from the group consisting of: .0C- χ (OR) 3 _ χ . where x=0-3 and R=hydrocarbon radical; VC1 A ; VO (AcAc) 2 , where AcAc*=acetyl acetonate V(AcAc) 3 , where AcAc=acetyl acetonate V0Cl χ (AcAc) 3 _ χ , where x=l or 2 and AcAc-acetyl acetonate; and VCl 3 .nB, where n=2-3 and B=Lewis base capable of form¬ ing hydrocarbon-soluble complexes with VC1«; and (b) organo-aluminum compound selected from the group consisting of: A1R 3 A1R 2 C1, A1RC1 2 , AlR'RCl, A1(0R')R 2 , R 2 A1-0A1R' 2 , Al j I and mixtures thereof where R and R' are the same or different hydrocarbyl radicals. 55. The process according to claim 53 wherein a catalyst comprising VCl, and Al j R Cl, is used in a first reactor and a catalyst comprising VOCl, and A1«R' -iCl is used in a second reactor wherein R and R 1 are the same or different hydrocarbyl moiety. 56. The process according to claim 55 wherein R and R' are ethyl. 57. The process according to claim 51 wherein the reactor is a tubular reactor. 58. The process according to claim 52 wherein the catalyst components are premixed. 59. The process according to claim 52 wherein the catalyst components are premixed and then aged. 60. The process according to claim 51 wherein the temperature of the reaction mixture at the initia¬ tion of polymerization is about -80°C to 50°C. 61. The process according to claim 51 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 62. The process according to claim 59 wherein- the catalyst components are aged for at least 0.5 sec¬ onds. 63. The process according to claim 52 wherein the mole ratio of aluminum ro vanadium in the catalyst is about 2 to 25. 64. The process according to claim 51 wherein the polymerization is a solution polymerization. 65. The process according to claim 51 wherein the polymerization is conducted in a solvent for the re¬ action mixture; and wherein the copolymer concentration in the reaction mixture at the completion of polymeriza- .tion in each reactor is about 3 to about 15% on a weight copolymer per weight of solvent basis. 66. The process according to claim 51 wherein the maximum outlet temperature of the reaction mixture at the completion of polymerization is about 50°C. 67. The process according to claim 59 wherein the catalyst comprises components that are premixed and then aged for about 1 to 50 seconds. 68. The process according to claim 53 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 69. The process according to claim 68 wherein the polymerization is conducted in a solvent for the re¬ action mixture, and wherein the copolymer concentration in the reaction mixture at the completion of polymeriza¬ tion in each reactor is about 3% to 10% on a weight of polymer per weight of solvent basis. 70. The process according to claim 51 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 70°C. 71. The process according to claim 51 wherein the polymerization is adiabatic. 72. The process according to claim 51 wherein the polymerization process is continuous and is conduct¬ ed in hexane solvent. 73. The process according to claim 57 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other, alpha- olefin monomer and diene are fed to said tubular .reactor at multiple feed sites. 74. In a polymerization process for producing copolymer from a reaction mixture comprised of catalyst and a monomer feed comprising ethylene, at least one other alpha-olefin monomer, and optionally, at least one non-conjugated diene the improvement which comprises producing a polymodal MWD copolymer by conducting the polymerization: (a) a substantially mix free reactor; (b) with essentially one active catalyst spe¬ cies wherein said catalyst species exhibits a decay in activity with respect to polymeriza¬ tion time; (c) using at least one reaction mixture which is essentially transfer-agent free; (d) in such a manner and under conditions sufficient to initiate propagation of essen¬ tially all copolymer chains formed from the catalyst species simultaneously; (e) adding a catalyst reactivator to the re¬ action mixture after polymerization has pro¬ gressed for a finite time; and (f) recovering polymer at -the completion of polymerization; thereby producing a polymodal MWD ethylene copolymer comprising at least two different molecular weight modes wherein each mode having a narrow MWD and at least one of two characteristics, (1) an M /M of less than 2 and and M /M of less than 1.8. 75. The process according to claim 74 wherein the catalyst comprises a Ziegler catalyst. 76. The process according to claim 75 wherein catalyst comprises a hydrocarbon-soluble vanadium com¬ pound and an organo-aluminum compound which react to form essentially one active catalyst species, at least one of the vanadium compound and organo aluminum com¬ pound containing a valence-bonded halogen. 77. The process according to claim 76 wherein the catalyst comprises: (a) hydrocarbon-soluble vanadium compound se¬ lected from the group consisting of: V0Cl χ (0R) 3 _ χ , where x=0-3 and R=hydro carbon radical ; VC1 A ; VO (AcAc) 2 , where AcAc=acetyl acetonate V(AcAc) 3 , where AcAc=acetyl acetonate V0Cl χ (AcAc) 3 _ χ , where x=l or 2 and AcAc-acetyl acetonate; and VCl 3 .nB, where n=2-3 and B=Lewis base capable of form¬ ing hydrocarbon-soluble complexes with VCl-; and (b) organo-aluminum compound selected from the group consisting of: A1R 3 A1R 2 C1, A1 2 R 3 C1 3 , A1RC1 2 , AlR'RCl, A1(0R')R 2 , R 2 A1-0A1R' 2 , A1R 2 I and mixtures thereof where R and R 1 are hydrocarbon radicals. 78. The process according to claim 76 wherein the catalyst comprises a VCl. and Al-R^Cl- wherein R is a hydrocarbyl moiety. 79. The process according to claim 78 wherein R is ethyl. 80. The process according to claim 74 wherein the reactor is a tubular reactor having a first inlet port and at least one additional inlet port downstream of the first inlet port, catalyst reactivator being add¬ ed through said additional inlet port. 81. The process according to claim 74 wherein ' the reactor is a batch reactor and the catalyst reacti¬ vator is added at a finite time after initiation of polymerizatio . 82. The process according to claim 74 wherein the temperature of the reaction mixture at the initia¬ tion of polymerization is about -80°C to 50°C. 83. The process according to claim 74 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 84. The process according to claim 74 wherein the polymerization is a solution polymerization. 85. The process according to claim 75 wherei the catalyst components 'are premixed. 86. The process according to claim 85 wherein the catalyst components are premixed and then aged. 87. The process according to claim 86 wherein the premixed catalyst components are aged for at least 0.5 seconds. 88. The process according to claim 75 wherein the mole ratio of aluminum to vanadium in the catalyst is about 2 to 25. 89. The process according to claim 74 wherein the polymerization is conducted in a solvent for the re¬ action mixture and wherein the copolymer concentration in the reaction mixture at the completion of polymeriza¬ tion is about 3 to about 15Z on a weight copolymer per weight solvent basis. 90. The process according to claim 74 wherein the maximum at the completion of polymerization tempera¬ ture of the reaction mixture is about 50°C. 91. The process according to claim 85 wherein the catalyst comprises components that are premixed and then aged for about 1 to 50 seconds. 92. The process according to claim 85 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 93. The process according to claim 92 wherein the polymerization is conducted in a solvent for the re¬ action mixture, and wherein the copolymer concentration in the reaction mixture at the completion of polymeriza¬ tion is about 3Z to 10Z on a weight of polymer per weight of solvent basis. 94. The process according to claim 74 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 70°C. 95. The process according to claim 74 wherein the polymerization is adiabatic. 96. The process according to claim 74 which is continuous and is conducted in hexane solvent. 97. The process according to claim 74 wherein the reactor is a tubular reactor. 98. The process according to claim 97 wherein the catalyst reactivator is introduced to said tubular reactor at multiple additional inlet ports said reacti¬ vator being optionally introduced with additional monomer. 99. In a polymerization process for producing copolymer from a reaction mixture comprised of catalyst and a monomer feed comprising ethylene and at least one other alpha-olefin monomer, ' and optionally at least one non-conjugated diene, the improvement which comprises producing a polymodal MWD copolymer by conducting the polymerization: (a) in at least one reactor, said reactor be¬ ing a substantially mix free reactor; (b) with essentially one catalyst system which generates multiple active catalyst spe¬ cies each catalyst species initiating the growth of polymer chains that attain a differ¬ ent average molecular weight than those produced by other catalyst species; (c) using at -least one reaction mixture which is essentially transfer-agent free; (d) in such a manner and under conditions sufficient to initiate propagation of essen¬ tially all copolymer chains made with a par¬ ticular catalyst species simultaneously; (e) recovering polymer at the completion of polymerization; thereby producing a polymodal MWD ethylene copolymer comprising at least two different molecular weight modes wherein each mode has a narrow MWD and at least one of two characteristics, (1) an M w/M n of less than 2 and and M-/H, of less than 1. 8. 100. The process according to claim 99 where¬ in the catalyst comprises a Ziegler catalys t . 101 . The proces s according to claim 99 where¬ in said catalys t comprises a hydrocarbon-soluble vanadium compound and an organo-aluminum compound which* react to form es sentially at least two active catalyst species , at least one of the vanadium compound and organo aluminum compound containing a valence-bonded halogen. 102. The process according to claim 101 wherein the catalyst comprises : (a) hydrocarbon-soluble vanadium compound se¬ lected from the group consisting of: .OC_ χ .OR) 3 _ χ ) where x=0-3 and R=hy ro carbon radical ; VC1 A VO (AcAc) 2 , where AcAc=acetyl acetonate V(AcAc) 3 , where AcAc=acetyl acetonate V0Cl χ (AcAc ) 3 _ χ , where x=l or 2 and AcAc-acetyl acetonate ; and VCl 3 .nB, where n=2-3 and B=Lewis base capable of form¬ ing hydrocarbon-soluble complexes with VCl.,; and (b) organo-aluminum compound selected from the group consisting of: A1R 3 A1R 2 C1, A1 2 R 3 C1 3 , A1RC1 2 , AlR'RCl, A1(0R*)R 2 , R 2 A1-0A1R' 2 A1R 2 I and mixtures thereof, where R and R' are hydrocarbon radicals. 103. The process according to claim 102 wherein the catalyst comprises V0C1- and A1R 2 C1 where R is a hydrocarbyl moeity. 104. The process according to claim 103 wherein R is ethyl. 105. The process according to claim 99 where- .in the reactor is a tubular reactor. 106. The process according to claim 99 where¬ in the temperature of the reaction mixture at the ini¬ tiation of polymerization is about -80°C to 50°C. 107. The process according to claim 99 where¬ in the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 108. The process according to claim 99 where¬ in the polymerization is a solution polymerization. 109. The process according to claim 100 wherein the catalyst components are premixed. 110. The process according to claim 109 wherein the catalyst components are premixed and then aged. 111. The process according to claim 110 wherein the catalyst components are aged for about 0.5 seconds. 112. The process according to claim 101 wherein the mole ratio of aluminum to vanadium in the catalyst is about 2 to 25. 113. The process according to claim 108 wherein the polymerization is conducted in a solvent for the reaction mixture; and wherein the copolymer concen¬ tration in the reaction mixture at the completion of polymerization is about 3 to 15Z on a weight copolymer per weight of solvent basis. 114. The process according to claim 109 wherein the catalyst comprises components that are pre¬ mixed and then aged for about 1 to 50 seconds. 115. The process according to claim 109 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 116. The process according to claim 99 where¬ in the polymerization is conducted in a solvent for the reaction mixture, and wherein the copolymer concentra¬ tion in the reaction mixture at the completion of polymerization is about 3% to 10% on a weight of polymer per weight of solvent basis. 117. The process according to claim 99 where¬ in the maximum temperature of the reaction mixture at the completion of polymerization is about 70°C. 118. The process according to claim 99 where¬ in the polymerization is adiabatic. 119. The process according to claim 99 which is continuous and is conducted in hexane solvent. 120. The process according to claim . 105 ' wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha- olefin monomer and diene are fed to said tubular reactor at multiple feed sites. 121. In a polymerization process for produc¬ ing copolymer from a reaction mixture comprised of cata¬ lyst and a monomer feed comprising ethylene at least one other alpha-olefin monomer and optionally at least one non conjugated diene, the improvement which comprises producing a polymodal MWD copolymer by conducting the polymerization: (a) in at least one reactor, said reactor be¬ ing a substantially mix free reactor; (b) using at least one reaction mixture which is essentially transfer-agent free; (c) with at least one first catalyst in such a manner and under conditions sufficient to initiate propagation of essentially all copolymer chains simultaneously; (d) introducing at least one additional cata¬ lyst feed together with additional monomer at one or more finite times after initiation of polymerization; thereby initiating additional copolymer chains wherein the propagation of essentially all such additional copolymer chains is initiated simultaneously and wherein the additional catalyst feed, is the same or different than the first catalyst; thereby producing a polymodal MWD ethylene copolymer comprising at least two different molecular weight modes wherein each mode having a narrow MWD and at least one of two characteristics, (1) an M /M of less than 2 and and M /M of less than 1.8. 122. The process according to claim 121- wherein the catalyst comprises a Ziegler catalyst. 123. The process according to claim 120 wherein each catalyst comprises a hydrocarbon-soluble vanadium compound and an organo-aluminum compound which react to form essentially one active catalyst species, at least one of the vanadium compound and organo alumi¬ num compound containing a valence-bonded halogen. 124. The process . according to claim 123 wherein each catalyst comprises: (a) hydrocarbon-soluble vanadium compound se¬ lected from the group consisting of: V0Cl χ (0R) 3 . χ . where x=0-3 and R=hydrocarbon radical; C1 4 ; VO (AcAc) 2 , where AcAc=acetyl acetonate V(AcAc) 3 , where AcAc=acetyl acetonate V0Cl χ (AcAc) 3 _ χ , where x=l or 2 and AcAc-acetyl acetonate; and - VCl 3 .nB, where n=2-3 and B=Lewis base capable of form¬ ing hydrocarbon-soluble complexes with VCl.,; and (b) organo-aluminum compound selected from the group consisting of: A1R 3 A1R 2 C1, A1 2 R 3 C1 3 , A1RC1 2 , AlR'RCl, A1(0R')R 2 , R 2 A1-0A1R 2 A1R 2 I and mixtures thereof, where R and R' are hydrocarbon radicals. 125. The process according to claim 124 wherein the catalyst comprises VCl, and A1 2 R,C1., or V0C1-, and Al 2 R' 3 Cl wherein R and R' are the same or different hydrocarbyl moeity. 126. The process according to claim 124 wherein R and R' are ethyl. 127. ' The process according to claim 125 wherein the reactor is a tubular reactor having a reactor inlet and at least one sidestream inlet port downstream of the reactor inlet, additional catalyst, and optionally, additional monomer being added through said sidestream inlet port. 128. The process according to claim 127 wherein the additional catalyst is the same catalyst species as that added at the initiation of polymeriza¬ tion. 129. The process according to claim 123 wherein said additional catalyst is a different catalyst species than that introduced at the initiation of poly¬ merization. 130. The process according to claim 121 wherein the temperature of the reaction mixture at the initiation of polymerization is about -80°C to 50°C. 131. The process according to claim 121 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 200°C. 132. The process according to claim 121 wherein the polymerization is a solution polymerization. 133. The process according to claim 122 wherein the catalyst components are premixed. 134. The process according to claim 133 wherein the catalyst components are premixed and then aged for at least 0.5 seconds. 135. The process according to claim 133 wherein the catalyst components are premixed then aged. 136. The process according to claim 123 wherein the mole ratio of aluminum to vanadium in the catalyst is about 2 to 25. 137. The process according to claim 132 wherein the polymerization is conducted in a solvent for the reaction mixture, and wherein the copolymer concen¬ tration in the reaction mixture at the completion of polymerization is about 3 to about 15% on a weight copolymer per weight of solvent basis. 138. The process according to claim 121 wherein the maximum temperature of the reaction mixture at the completion of polymerization is about 50°C. 139. The process according to claim 132 wherein the catalyst comprises components that are pre¬ mixed and then aged for about 1 to 50 seconds. 140. The process according to claim 133 wherein the mole ratio of aluminum to vanadium in the catalyst is about 4 to 15. 141. The process according to claim 140 wherein the polymerization is conducted in a solvent for the reaction mixture and wherein the copolymer concen¬ tration in the reaction mixture at the completion of polymerization is about 3 to 10% on a weight of polymer per weight of solvent basis. 142. The process according to claim 121 wherein the maximum outlet temperature of the reaction .mixture at the completion of polymerization is about 70°C. 143. The process according to claim 121 wherein the polymerization is adiabatic. 144. The process according to claim 121 wherein the polymerization is a continuous process and is conducted in hexane solvent. 145. The process according to claim 121 wherein the polymerization is conducted in at least one tubular reactor. 146. The process according to claim 1 wherein the catalyst species is derived from the reaction of VCl, and an aluminum compound of the formula A1 2 R-X 3 wherein X is halogen and R is a hydrocarbyl radical. 147. The process according to claim 146 wherein the aluminum compound is ethyl aluminum sesquichloride. 148. The process according to claim 29 where¬ in one of the catalyst species is derived from the reaction of VCl, and an aluminum compound of the formula AI2R3X3 and wherein a second catalyst species is derived from the reaction of V0C1-, with an aluminum compound of the formula Al 2 R.,X, wherein X is halogen and R is a hydrocarbyl radical. 149. The process according to claim 148 wherein the aluminum compound is ethyl aluminum sesquichloride. 150. The process according to claim 51 where¬ in the catalyst species is derived from the reaction of VCl, and an aluminum compound of the formula Al ^ R-X., wherein X is halogen and R is a hydrocarbyl radical. 151. The process according to claim 148 wherein the aluminum compound is ethyl aluminum sesquichloride. 152. The process according to claim 74 where¬ in the catalyst species is derived from the reaction of VCl, and an aluminum compound of the formula A1 2 R,X, wherein X is halogen and R is a hydrocarbyl radical. 153. The process according to claim 152 wherein the aluminum compound is ethyl aluminum sesqui¬ chloride. 154. The process according to claim 99 where- in the catalyst species is derived from the reaction of V0C1, and an aluminum compound of the formula A1R 2 X wherein X is halogen and R is a hydrocarbyl radical. 155. The process according to claim 154 wherein the aluminum compound is diethy1 aluminum chloride. 156. The process according to claim 121 wherein the catalyst species is derived from the re¬ action of VCl, and an aluminum compound of the formula Al 2 RoX 3 wherein X is halogen and R is a hydrocarbyl rad¬ ical. 157. The process according to claim 156 wherein the aluminum compound is ethyl aluminum sesqui¬ chloride. 158. The product according to claim 25 where¬ in the polymodal polymer comprises at least two MWD modes, the M of any two adjacent modes differing from one another by at least 50Z and any one mode comprising at least 10 wt% of the total polymer. 159. The product prepared according to the process of claim 29. 160. The product according to claim 159 wherein the polymodal polymer comprises at leat two MWD modes, the 11 of any two adjacent modes differing from one another by at leat 50Z and any one mode comprising at least 10 wt% of the total polymer. 161. The product prepared according to the process of claim 51. 162. The product according to claim 161 wherein the polymodal polymer comprises at leat two MWD modes, the M of any two adjacent modes differing from one another by at leat 50% and any one mode comprising at least 10 wt% of the total polymer. 163. The product prepared according to the process of claim 74. 164. The product according to claim 163 wherein the polymodal polymer comprises at leat two MWD modes, the M of any two adjacent modes differing from one another by at leat 50% and any one mode comprising at least 10 wt% of the total polymer. 165. The product prepared according to the process of claim 99. 166. The product according to claim 165 wherein the polymodal polymer comprises at leat two MWD modes, the M of any two adjacent modes differing from one another by at leat 50% and any one mode comprising at least 10 wt% of the total polymer. 167. The product prepared according to the process of claim 121. 168. The product according to claim 167 wherein the polymodal polymer comprises at leat two MWD modes, the M of any two adjacent modes differing from one another by at leat 50Z and any one mode comprising at least 10 wtZ of the total polymer. 169. The process according to claim 1 wherein the catalyst species is derived from the reaction of VCl4, and an aluminum comp r ound of the formula AIRn 3,-n,' wherein n can vary from 1 to 2, X is halogen and R is a hydrocarbyl radical. 170. The process according to claim 31 where¬ in the aluminum comp c ound has the formula AIRnX_3-n , here- in n can vary from 1 to 2, X is halogen R is a hydro¬ carbyl radical. 171. The process according to claim 51 where¬ in the catalyst species is derived from the reaction of VCl4, and an aluminum compound of the formula AIRnX3„-n' ■wherein n can vary from 1 to 2, X is halogen and R is a hydrocarbyl radical. 172. The process according to claim 74 where¬ in the catalyst species is derived from the reaction of VCl4, and an aluminum comp r ound of the formula AIRnX3--n, wherein n can vary from 1 to 2, X is halogen and R is a hydrocarbyl radical. 173. The process according to claim 99 where¬ in the catalyst species is derived from the reaction of VO l3- and an aluminum comp^ound of the formula AIRnX3-,-n,' wherein n can vary from 1 to 2, X is halogen and R is a hydrocarbyl radical. CLAIMS 174 to 181 were missing from the international application as originally filed. 182. The product according to claim 163 wherein the copolymer is cured. 183. The product according to claim 163 wherein said copolymer product is blended with base stock lubricating oil. 184. The product according to claim 183 wherein said copolymer product is blended with the base stock lubricating oil in an amount from about 0.001 to about 49 wtZ copolymer based on the oil plus copolymer. 185. The product according to claim 165 wherein the copolymer is cured. 186. The product according to claim 165 wherein said copolymer product is blended with base ' stock lubricating oil. 187. The product according to claim 186 wherein said copolymer product is blended with the base stock lubricating oil in an amount from about 0.001 to about 49 wt% copolymer based on the oil plus copolymer. 188. The product according to claim 167 wherein the copolymer is cured. 189. The product .according to claim 167 wherein said copolymer product is blended with base stock lubricating oil. 190. The product according to claim 189 wherein said copolymer product is blended with the base stock lubricating oil in an amount from about 0.001 to about 49 wtZ copolymer based on the oil plus copolymer. 191. The process according to claim 9 wherein the catalyst components are premixed and then aged. 192. The process according to claim 35 where¬ in said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha olefin monomer and diene is fed to said tubular reactor at multiple feed sites. 193. The process according to claim 74 where¬ in said polymerization is conducted in a tubular reac¬ tor. 194. The process according to claim 193 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha olefin monomer and diene is fed to said tubular reactor at multiple feed sites. 195. The process according to claim 99 where¬ in said polymerization is conducted in at least one tu¬ bular reactor. 196. The process according to claim 195 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha olefin and diene is fed to said tubular reactor at mul¬ tiple ed sites. 197. The process according to claim 121 wherein said polymerization is conducted in at least one tubular reactor. 198. The process according to claim 197 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha olefin and diene is fed to said tubular reactor at mul¬ tiple feed sites. 199. The process according to claim 145 wherein said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha olefin monomer and diene are fed to said tubular reactor at multiple feed sites. 200. The process according to claim 97 where- • in said reaction mixture further comprises diene, and wherein at least one of said ethylene, other alpha- olefin monomer and diene is fed to said tubular reactor at multiple feed sites. 201. The process according to claim 107 wherein the maximum temperature of the reaction mixture is 50°C. 202. A copolymer of ethylene and at least one other alpha-olefin monomer, which copolymer is a superposition of two or more copolymer modes each of which has a MWD characterized by having at least one of the following characteristics: a J/L^/TS^ of less than 2 and VL Z /VL^ of less than 1.8. 203. The copolymer as defined by claim 202 wherein each of said copolymer modes has a M w /M n of less than 2 and M g /M^- of less than 1.8. 204. The copolymer as defined by claim 202 wherein said alpha-olefin monomer contains 3-18 carbon atoms. 205. The copolymer as defined by claim 204 wherein said alpha-olefin monomer contains 3-6 carbons. 206. The copolymer as defined by claim 204 wherein said alpha-olefin is selected from the group consisting of propylene, butene-1, pentene-1, hexene-1, heptene-1, octene- 1, and dodecene-1. 207. The copolymer as defined by claim 206 wherein said alpha-olefin is propylene. 208. The copolymer as defined by claim 202 consisting essentially of ethylene and propylene. 209. The copolymer as defined by claim 202 consisting essentially of ethylene, propylene and non-conjugated diene. 210. The copolymer as defined by claim 209 wherein said non-conjugated diene is a straight chain acyclic diene. 211. The copolymer as defined by claim 210 wherein said straight chain acyclic diene is selected from the group consisting of 1,4-hexadiene and 1,6-octadiene. 212. The copolymer as defined by claim 210 wherein said non-conjugated diene is a branched chain acyclic diene. 213. The copolymer as defined by claim 212 wherein said branched chain acyclic diene is selected from the group consisting of: 5-methyl-l, .4-hexadiene; 3,7-dimethyl-l, 6- octadiene; 3,7-dimethyl-l, 7-octadiene and the mixed iso ers of dihydro-myrcene. 214. The copolymer as defined by claim 209 wherein said non-conjugated diene is a single ring diene. 215. The copolymer as defined by claim 214 wherein said single ring diene is selected from the group consisting of: 1, 4-cyclohexadiene; 1, 5-cyσlooctadiene; and 1,5- cyclododecadiene. 216. The copolymer as defined by claim 203 wherein said non-conjugated diene is a multi-ring fused or bridged ring diene. 217. The copolymer as defined by claim 216 wherein said multi-ring alicyclic fused or bridged ring diene is selected from the group consisting of: tetrahydroindene; ethyltetrahydroindene; dicyσlopentadiene; bi-cyclo-(2,2,1) -hepta-2, 5-diene; alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2-norbornene (MNB) , 5-ethylidene-2-norbomene (ENB) , 5-propylidene-2- norbornene, 5-isopropylidene-2-norbσrnene, 5-(4- cyclopentenyl) -2-norbornene; and 5-cyclohexylidene-2- norbornene. 218. The copolymer as defined by claim 209 wherein said non-conjugated diene is 5-ethylidene-2-norbornene. 219. The copolymer as defined by claim 209 wherein the amount of non-conjugated diene on a weight basis of said copolymer is about 0-20%. 220. The copolymer as defined by claim 219 wherein the amount of diene on a weight basis of the copolymer is about 0-15%. 221. The copolymer as defined by claim 220 wherein the amount of diene on a weight basis of the copolymer is about 0-10%. 222. The copolymer as defined by claim 202 wherein the average ethylene content of each copolymer mode is at least 10% on a weight basis. 223. The copolymer as defined by claim 222 wherein each copolymer mode comprises at least about 30% ethylene. 224. The copolymer as defined by claim 222 wherein each copolymer mode comprises less than about 90% ethylene. 225. The copolymer as defined by claim 202 wherein the weight average molecular weight of each mode is between about 2,000-12,000,000. 226. The copolymer as defined by claim 225 wherein the weight average molecular weight of each mode is between about 10,000-1,000,000. 227. The copolymer as defined by claim 226 wherein the weight average molecular weight of each mode is between about 20,000-750,000. 228. The copolymer as defined by claim 202 wherein the Mrø/M jj ratio for the whole copolymer is about 1-50. 229. The copolymer as defined by claim 202 wherein the M.^ of any two adjacent copolymer MWD modes differs, by at least 50%. 230. The copolymer as defined by claim 229 wherein each mode comprises at least 10% by weight of the total copolymer. 231. A basestock lubricating oil blended with the copolymer product according to claim 202. 232. The basestock lubricating oil as defined by claim 231 wherein said copolymer product is blended in an amount of 0.001 to about 49 weight percent copolymer based upon oil plus copolymer. 233. A cured copolymer as defined by claim 202. 234. A cured copolymer as defined by claim 209. 235. The copolymer as defined by claim 202 wherein the Intra-CD of at least one of said modes is greater than 5%. 236. The copolymer as defined by claim 235 wherein the Intra-CD of at least one of said modes is greater than 15%. 237. The copolymer as defined by claim 209 wherein the Intra-CD of at least one of said modes is greater than 5%. 238. The copolymer as defined by claim 237 wherein the Intra-CD of at least one of said modes is greater than 5%. 239. A cured copolymer as defined by any one of claims 235-238. 240. A basestock lubricating oil blended with the copolymer product according to any one of claims 235-238. 241. The basestock lubricating oil as defined by claim 240 wherein said copolymer product is blended in an amount of 0.001 to about 49 weight percent copolymer based upon oil plus copolymer.

Inventors: COZEWITH CHARLES, JU SHIAW, VERSTRATE GARY WILLIAM, COZEWITH, CHARLES, JU, SHIAW, VERSTRATE, GARY, WILLIAM
Applicants: EXXON RESEARCH ENGINEERING CO, EXXON RESEARCH AND ENGINEERING COMPANY
Application year: 1985
Main classification: C08F10
IPC codes: B01J19, C08F2, C08F4, C08F210, C08L23, C10M143