THERMOSET ELASTOMERS

Abstract: The subject invention provides a thermoset elastomer comprising a crosslinked pseudorandom or substantially random interpolymer of: (a) from 15 to 70 weight percent of at least one alpha -olefin, (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (c) from 0 to 15 weight percent of at least one diene. The subject invention further provides provides a thermoplastic vulcanizate comprising the thermoset elastomers of the invention as provided in a thermoplastic polyolefin matrix. The subject invention further provides processes for preparing the inventive thermoset elastomers and thermoplastic vulcanizates, as well as parts fabricated therefrom. The inventive materials have a superior balance of properties, as compared to EPM and EPDM based materials.

Description: THHRMOSHT HI . ASTOMF. S The subject invention pertains to thermoset elastomers, to a process for their preparation, and to products fabricted from such elastomers. Elastomers are defined as materials which experience large reversible deformations under relatively low stress. Elastomers are typically diaracterized as having structural irregularities, non-polar structures, or flexible units in the polymer chain. Some examples of commercially available elastomers include natural rubber, ethylene propylene (EPM) copolymers, ethylene propylene/diene (EPDM) copolymers, styrene/butadiene copolymers, chlorinated polyethylene, and silicone -rubber. Thermoplastic elastomers are elastomers having thermoplastic properties. That is, theπnoplastic elastomers may be molded or oth<τwi∞ shaped and repro∞ssed at temperatures above their melting or softening point One example of theπnoplastic elastomers is styrene-butadiene-styrene (SBS) block copolymers. SBS block copolymers exhibit a two phase morphology consisting of glassy polystyrene domains connected by rubbery butadiene segments. At temperatures between the glass transition temperatures of the butadiene midblock and the styrene endblocks, that is, at temperatures from -90°C to 116°C the SBS copolymers act like a crosslinked elastomer. European Patent Publication 416,8 IS discloses pseudorandom ethylene-styrene interpolymers. Uncrosslinked pseudorandom ethylene styrene interpolymers exhibit a decreased modulus at temperatures above the melting or softening point of the interpolymer. SBS copolymers and uncrosslinked ethylene-styrene pseudorandom interpolymers suffer the disadvantages of relatively low mechanical strength, susceptibility to ozone degradation (to the extent that they have sites of unsaturation in the polymer backbone), and utility in only applications where the temperature of the elastomer will not exceed the melting or softening point of the elastomer. In contrast, thermoset elastomers are elastomers having thermoset properties. That is, thermoset elastomers irreversibly solidify or "set" when heated, generally due to an irreversible crosslinking reaction. Two examples of thermoset elastomers are crosslinked etbylene-propylene monomer rubber (EPM) and crosslinked ethylene-ptxipylene-diene monomer rubber (EPDM). EPM materials are made by the copolymerization of ethylene and p opylene. EPM materials are typically cured with peroxides to give rise to crosslinking, and thereby induce thermoset properties. EPDM materials are linear interpolymers of ethylene, propylene, and a nonconjugated diene such as 1,4- hexadiene, dicyclopentadiene, or ethylidene norbomene. -EPDM materials are typically vulcanized with sulfur to induce thermoset properties, although they alternatively may be cured with peroxides. While EPM and EPDM materials are advantageous in that they have applicability in higher temperature applications, EPM and EPDM elastomers suffer the disadvantages of low green strength (at lower ethylene contents), of a higher susceptibility of the cured elastomer to attack by oils than characteristic of styrene butadiene rubbers, and of resistance of the cured elastomer to surface modification. Elastomers suitable for use over a broad range of temperatures and which are also less susceptible to ozone degradation are desired. Thermoset elastomers which are prepared from elastomers having high green strength (which provides greater flexibility in their handling prior to curing) are particularly desired. Also desired, are thermoset elastomers which are resistant to oil, which are useful in fabricated parts which typically contact oil, such as automotive parts and gaskets. Also desired are thermoset elastomers which easily undergo surface modification, to promote surface adhesion of the elastomer and or to provide ionic sites on the elastomer surface. Also desired is a process for preparing such thermoset elastomers. Thermoplastic vulcanizates are crystalline polyolefinic matrices through which thermoset elastomers are generally uniformly distributed. Examples of thermoplastic vulcanizates include EPM and EPDM thermoset materials distributed in a crystalline polypropylene matrix. Such thermoplastic vulcanizates are disadvantageous, in that they are susceptible to oil degradation. Thermoplastic vulcanizates which are more resistant to oil are desired. Also desired is a process for preparing such thermoplastic vulcanizates. Summary of Invention The subject invention provides a thermoset elastomer comprising a crosslinked substantially random interpolymer of: (a) from IS to 70 weight percent of at least one α-olefm, (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (c) from 0 to 15 weight percent of at least one diene. The subject invention further provides a process for making a thermoset elastomer comprising: (a) reacting at least one α-olefin with at least one vinylidene aromatic compound in the presence of a constrained geometry catalyst to form a substantially random interpolymer, and (b) curing the substantially random interpolymer to form a thermoset elastomer. The subject invention further provides a thermoplastic vulcanizate comprising a blend of: (1) a crosslinked substantially random interpolymer of (a) from IS to 70 weight percent of at least one α-olefin, (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (c) from 0 to IS weight percent of at least one diene; and (2) at least one theπnoplastic polyolefin. The subject invention further provides a process for making a thermoplastic vulcanizate comprising: (a) reacting at least one α-olefin with at least one vinylidene aromatic compound and optionally at least one diene in the presence of a constrained geometry catalyst to form a substantially random interpolymer, (b) intimately mixing the substantially random interpolymer with at least one theπnoplastic polyolefin at a temperature above the melting or softening point of the thermoplastic polyolefin; (c) providing to the intimate mixture an agent for curing the substantially random interpolymer, (d) simultaneously curing the substantially random interpolymer and compounding the intimate mixture to form a theπnoplastic vulcanizate. The subject invention further comprises fabricated parts comprising the thermoset elastomers or thermoplastic vulcanizates of the invention. These and other embodiments are more fully described in the following Detailed Description. The term "polymer" as used herein refers to a polymeric compound prepared by polymerizing monomers whether of the same or a different type. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term interpolymer as defined hereinafter. The teπn "interpolymer" as used herein refers to polymers prepared by the polymerization of at least two different types of monomers. The generic teπn interpolymer thus includes copolymers, usually employed to refer to polymers prepared from two different monomers, and polymers prepared from more than two different types of monomers. Statements herein that a polymer or interpolymer comprises or contains certain monomers, mean that such polymer or interpolymer comprises or contains polymerized therein units derived from such a monomer. For example, if a polymer is said to contain ethylene monomer, the polymer will have incorporated in it an ethylene derivative, that is, -O-2-CH2-. The elastomeric thermoset compositions of the mvention are preferably substantially random substantially linear or linear interpolymers comprising an olefin and a vinylidene aromatic monomer, which interpolymers have been crosslinked to yield thermoset behavior . As used herein, the teπn "substantially random" means that the distribution of the monomers of the interpolymer can be described by the Bemoullian statistical model or by a first or second order Markovian statistical model, as described by J. C. Randall in Polymer Sequence Determination, Carbon-13 NMR Method, Academic Press New York, 1977, pp. 71-78. Substantially random interpolymers do not contain more than IS weight percent of the total amount of vinylidene aromatic monomer in blocks of more than three vinylidene aromatic monomer units. Pseudorandom interpolymers are a subset of substantially random interpolymers. Pseudorandom interpolymers are characterized by an architecture in which all phenyl (or substituted pbenyl) groups which are pendant from the polymer backbone are separated by two or more carbon backbone units. In other words, the pseudorandom interpolymers of the invention, in their noncrosslinked state, can be described by the following general formula (using styrene as the vinylidene aromatic monomer and ethylene as the α-olefin for illustration): Noncrosslinked pseudorandom interpolymers are described in European Patent Publication 416,815- A, the relevant parts of which are incorporated herein by reference. While not wishing to be bound by any particular theory, it is believed that during the addition polymerization reaction of, for example, ethylene aiid styrene, in t-he presence of a constrained geometry catalyst as described below, if a styrene monomer is inserted into the growing polymer chain, the next monomer inserted will be an ethylene monomer or a styrene monomer inserted in an inverted or "tail-to- tail" fashion. It is believed that after an inverted or "tail-to-tail" styrene monomer is inserted, the next monomer will be ethylene, as the insertion of a second styrene monomer at this point would place it too close to the inverted styrene monomer, that is, less than two carbon backbone units away. Preferably, the substantially random pseudorandom interpolymer will be characterized as largely atactic, as indicated by a 13C-NMR spectrum in which the peak areas corresponding to the main chain methylene and methine carbons representing either meso diad sequences or racemic diad sequences does not exceed 75 percent of the total peak area of the main chain methylene and methine carbons. The substantially random/pseudorandom interpolymers may further be characterized as either linear or substantially linear. As used herein, the term "substantially linear" means that the interpolymer is characterized as having long chain branches. In contrast, the term "linear" means that the interpolymer lacks long chain branches. Substantially linear interpolymers are characterized as having a melt flow ratio, 11Q/I2 (as determined by ASTM D-1238) ≥ S.63, a molecular weight distribution (as determined by gel permeation chromatography) M-^/M^ ≤ (-i fi_) - 4-63, and either a critical shear rate at the onset of surface melt fracture of at least SO percent greater than the critical shear rate at die onset of surface melt fracture of a linear olefin polymer having about the same I2 and My//-Mjj or a critical shear rate at the onset of gross melt fracture of greater than about 4 x 10 6 dynes cm 2 . To identify the melt fracture phenomena, an apparent shear stress vs. apparent shear rate plot may be employed. According to Ramamurthy in Journal of Rheology, 30(2)337-357, 1986, above a certain critical flow rate, the observed extrudate irregularities may be broadly classified into two main types: surface melt fracture and gross melt fracture. Surface melt fracture occurs under apparently steady flow conditions and ranges in detail from loss of specular gloss to the more severe form of "sharkskin". As used herein, the onset of surface melt fracture is characterized at the beginning of losing extrudate gloss at which the surface roughness of extrudate can only be detected by 40 X magnification. Gross melt fracture occurs at unsteady flow conditions and ranges in detail from regular (alternating rough and smooth, helical, etc.) to random distortions. The critical shear rate at the onset of surface melt fracture and onset of gross melt fracture, as used herein, are based on the changes of surface roughness and configurations of the extrudates extruded by a GER. Substantially linear interpolymers of ethylene and styrene are disclosed in USP 5,272,236 and USP 5,272,236, and in U.S. Patent Application Serial Nos. 08/166,789 to inventors Lai et al. filed on December 13, 1993 and 08/166,412 to inventors Lai et al. filed on December 13, 1993, the disclosures of which are incorporated herein by reference. The α-olefin Monomer Suitable α-olefins are represented by the following formula: CH 2 =CHF where R is hydrogen or a bydrocarbyl radical having from one to twenty carbon atoms. Typical α- olefins include, for example, ethylene, propylene, 1-butene, 3-methyl-l-butene, 1-pentene, 4-methyl-l- pentene, 1-hexene, 5-methyl-l-hexene, 4-ethyl- 1-hexene, 1-octene, 1-dodecene, 3-phenylpropene, and mixtures thereof. Preferably, the α-olefin will comprise ethylene, or a mixture of ethylene with another α-olefin, such as 1-butene, 1-pentene, 4-methyl-l-pentene, 1-hexene, or 1-octene. The Vinylidene Aromatic Monomer Suitable vinylidene aromatic monomers are represented by the following formula: wherein R] is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is selected from the group of radicals consisting of phenyl, halophenyl, alkylphenyl, and alkylhalophenyl. Exemplary vinylidene aromatic monomers include styrene; α- melhylstyrene; the C 1 -C4 alkyl- or phenyl- ring substituted derivatives of styrene, sucfa as ortho-, meta-, and para-methylstyrene, or mixtures thereof; the ring halogenated styrenes such as chlorostyrene; vinylbenzocyclobutanes; and divinylbenzene. Styrene is a particularly desirable vinylidene aromatic monomer used in the practice of the present invention. The level of vinylidene aromatic monomer incorporated in the thermoset elastomers of the invention is at least 30, preferably at least 35 weight percent based on the weight of the interpolymer. The vinylidene aromatic monomer is typically incorporated in the interpolymers of the invention in an amount less than 70, more typically less than 60 weight percent based on the weight of the interpolymer. The Diene: One or more dienes can optionally be incorporated into the interpolymer to provide functional sites of unsaturation on the interpolymer useful, for example, to participate in crosslinking reactions. While conjugated dienes such as butadiene, 1,3-pentadiene (that is, piperylene), or isoprene may be used for this purpose, nonconjugated dienes are preferred. Typical nonconjugated dienes include, for example the open-chain nonconjugated diolefins such as 1,4-bexadiene (see U.S. Patent No. 2,933,480) and 7- methyl-l,6-octadiene (also known as MOCD); cyclic dienes; bridged ring cyclic dienes, such as dicyclopentadiene (see U.S. Patent No. 3,211,709); or alkylidenenorbornenes, such as methylenenorbornene or ethylidenenorbomene (see U.S. Patent No. 3,151,173). The nonconjugated dienes are not limited to those having only two double bonds, but rather also include those having three or more double bonds. The diene is incorporated in the elastomers of the invention in an amount of from 0 to 15 weight percent based on the total weight of the interpolymer. When a diene is employed, it will preferably be provided in an amount of at least 2 weight percent, more preferably at least 3 weight percent, and most preferably at least S weight percent, based on the total weight of the interpolymer. Likewise, when a diene is employed, it will be provided in an amount of no more than 15, preferably no more than 12 weight percent based on the total weight of the interpolymer. Preparation of the substantially random/pseudorandom interpolymers: The substantially random/pseudorandom interpolymers may be prepared via the solution, slurry, or gas phase interpolymerization of the α-olefin, the vinylidene aromatic compound, and the optional diene, in the presence of an olefin polymerization catalyst comprising a metal coordination complex and activating cocatalyst, such as are described in European Patent Publications 416,815- A, 468,651-A, 514,828-A, and 520,732-A, in U.S. Patent Application Serial No. 8,003, filed January 21, 1993, and in U.S. Patent Nos. 5,055,438, 5,057,475, 5,096,867, 5,064,802 and 5,132,380, the disclosures of which are incorporated herein by reference. Also suitable in the practice of the claimed invention are the monocydopentadienyl transition metal olefin polymerization catalysts taught in USP 5,026,798, as well as the catalysts disclosed in European Patent Publication 572,990- A2, the disclosures of which are incorporated herein by reference. The foregoing catalysts may be further described as comprising a metal coordination complex comprising a metal of Group m or IV or the Lantbanide series of the Periodic Table of the Elements and a delocalized π-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry the metal atom such that the angle at the metal between the centroid of the delocalized, substituted Il-bonded moiety and the center of at least one remaining substituent is less than sucfa angle in a similar complex containing a similar π-bonded moiety lacking in such constrain- inducing substituent, and provided further that for such complexes comprising more than one delocalized, substituted x-bonded moiety, only one thereof for each metal atom of the complex is a cyclic delocalized, substituted Il-bonded moiety. The catalyst further preferably comprises an activating cocatalysL 1. The metal coordination complex. The metal coordination complex employed will preferably correspond to the following formula: wherein R' at each occurrence is independently selected from the group consisting of hydrogen, hydrocarbyl, silyl, ge myl, cyano, halo and combinations thereof, each said R' having up to 20 non- hydrogen atoms, and with two R' groups (where R' is not hydrogen, halo, or cyano) being optionally joined together to foπn a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X at each occurrence independently is selected from the group consisting of hydride, halo, hydrocarbyl, silyl, germyl, hydrocarbyloxy, amido, siloxy, and combinations thereof, each said X having up to 20 non-hydrogen atoms; or when M is in the +3 oxidation state, X is preferably a stabilizing ligand comprising an amine, phosphine, ether or thioether functionality able to foπn a coordinate-covalent bond or chelating bond with M, or (when X is a hydrocarbyl) an ethylenic unsaturation able to form an η3 bond with M; Y is a divalent anionic ligand group comprising nitrogen, phosphorus, oxygen or sulfur (preferably -O-, -S-, -NR*-, or -PR*-) and having up to 20 non-hydrogen atoms, said Y being bonded to Z and M through said nitrogen, phosphorus, oxygen or sulfur, with Y and Z being optionally joined together to foπn a fused ring system; M is a Group 4 metal, especially titanium; Z is SiR*2, CR*2. SiR*2SiR*2. CR*2CR*2, CR*=CR*, CR*2SiR* 2 , GeR*2, BR*, or BR*2; wherein: R* at each occurrence is independently selected from the group consisting of hydrogen, hydrocarbyl, silyl, halogenated hydrocarbyl groups having up to 20 non-hydrogen atoms, and combinations thereof, with two R* groups from Z (when R* is not hydrogen) or an R* group from Z (when R* is not hydrogen) and an R* group from Y (when R* is not hydrogen) being optionally joined to form a fused ring system; and n is 1 or 2. The most preferred metal coordination complexes are amidosilane- or amidoalkanediyl- compounds corresponding to the following formula II: wherein: M is titanium bound in an η5 bonding mode to the cyclopentadienyl group; R' at each occurrence is independently selected from the group consisting of hydrogen, silyl, hydrocarbyl, and combinations thereof, each said R' having up to 10 carbon or silicon atoms, or with two R' groups (when R' is not hydrogen) being joined together to form a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to foπn a fused ring structure; E is silicon or carbon; X is independently at each occurrence hydride, halo, hydrocarbyl, or hydrocarbyloxy, each said X having up to 10 carbons, or when M is in the +3 formal oxidation state, X is preferably a stabilizing ligand such as a hydrocarbyl, silyl, amido or pbosphido ligand substituted with one or more aliphatic or aromatic ether-, thioether-, amine- or phosphine- functional groups, especially such amine or phosphine groups that are tertiary substituted, said stabilizing ligand having from 3 to 30 nonhydrogen atoms, or X is a C3-15 hydrocarbyl group containing ethylenic unsaturation; m is 1 or 2; and n is 1 or 2. Examples of these most preferred metal coordination complexes include compounds wherein the R' on the amido group is methyl, ethyl, propyl, butyl, pentyl, or hexyl (including isomers of these alkyls) norbornyl benzyl, phenyl, etc.; the cyclopentadienyl group is cyclopentadienyl, indenyl, tetrahydroindenyl fluorenyl octahydrofluorenyl, tetrahydrofluorenyl, etc.; R' on the foregoing cyclopentadienyl groups is independently at each occurrence hydrogen, methyl, ethyl, propyl, butyl, pentyl hexyl norbornyl benzyl phenyl etc.; and X is chloro, bromo, iodo, methyl ethyl propyl butyl pentyl hexyl (including isomers of these alkyls), norbornyl benzyl phenyl etc, or when M is in the +3 formal oxidation state, X is most preferably 2-dialkylaminobenzyl or 2-(dialkyl-aminomethyl)phenyl groups containing from 1 to 4 carbons in the alkyl groups, or an allyl, 1-methylallyl 2-methylallyl 1,1- dimethylallyl 1,2 -trimethylallyl, l-phenyl-3-benzylallyl or l,l-diρhenyl-3-(diphenylmethyl)allyl group. Specific embodiments of these most preferred metal coordination complexes include (tert- butylamidoKtetramemyl-η5-cyclopentaά enyl)-l,2-ethanediylzirconium dichloride; (tert-butylamido) (tetramethyl-η5-cyclopentadienyl)-l^-ethanediyltitanium dichloride; (methylamido)(tetramethyl-η5- cyclopentadienyl)- 1,2-ethanediylzirconium dichloride; (methylamido)(tetramethyl-η5- cyclopentamenyl l,2-ethanediylutanium dichloride; (eώylamidoXtetramethyl-η5- cyclopentadienyl)methylenetitanium dichloride; (tert-butylamido)dimethyl(tetramethyl-η5- cyclopentadienyl) silanetitanium dimethyl; (tert-butylamido)dimethyl (tetramethyl-η5- cyclopentadienyOsilanezirconium dibenzyl; (benzylamido)dimethyI(tettamethyl-η5- cyck>pentadienyl)silaneutanium dichloride; and (phenylphospbido)-dimethyl(tetramethyl-η5- cyck>pentadienyl)silane zirconium dibenzyl. Other preferred monocydopentadienyl metal coordination complexes useful to prepare the interpolymers will include titanium or zirconium in the +2 formal oxidation state and will correspond to die following formula III: wherein: R' at each occurrence is independently selected from the group consisting of hydrogen, hydrocarbyl silyl, germyl, cyano, halo and combinations thereof, each said R' having up to 20 non- hydrogen atoms, with two R' groups (when R' is not hydrogen, halo or cyano) being optionally joined together foπn a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X is a neutral η4-bonded diene group having up to 30 non-hydrogen atoms, which forms a II- complex or a σ-complex with M (as disclosed in U.S. Patent Serial No. 241,523, filed on May 12, 1994 or U.S. Patent Serial No. 267,993, filed on June 28, 1994, the disclosures of which are incorporated herein by reference); Y is -0-, -S-, -NR*-, -PR*-; M is titanium or zirconium in the +2 formal oxidation state; Z* is SiR* . CR*2, SiR* 2 SiR* 2 , CR* 2 CR*2, CR*=CR*. CR*2SiR* 2 , or GeR* 2 , wherein: R* at each occurrence is independently hydrogen, or a member selected from the group consisting of hydrocarbyl, silyl halogenated hydrocarbyl and mixtures thereof, each said R* having up to 20 non-hydrogen atoms, with two R* groups from Z* (where R* is not hydrogen), or an R* group from Z* (where R* is not hydrogen) and an R* group from Y (where R* is not hydrogen) being optionally joined to foπn a fused ring system. These are disclosed in full in U.S. Application Serial No. 82,197, filed June 24, 1993, the relevant portions of which are incorporated herein by reference. 2. The activating cocatalyst. The activating cocatalyst is employed to cause the metal coordination complex to become effective as an addition polymerization catalyst or to balance the ionic charge of a catalytically activated metal coordination complex. Suitable cocatalysts for use herein include polymeric or oligomeric alumoxanes, especially methylalumoxane and modified methyl alumoxane; polymeric, oligomeric or monomeric carbylboranes, especially tris(pentafluorophenyl)borane; aluminum alkyls; aluminum halides; haloaluπύnum alkyls; other strong Lewis adds; ammonium salts; oxidizing agents, such as silver salts, ferrocenium ions, etc; and mixtures of such cocatalysts. Preferred cocatalysts are noninterfering, noncoordinating, ion-forming boron compounds, such as tris(pentafluorophenyl)borane. Alumoxanes can be made as disclosed in U.S. Patent Nos. 5,542,199; 4,544,762; 5,015,749; and 5,041,585. the disdosures of which are incorporated herein by reference. So called modified methyl alumoxane (MMAO) is also suitable for use as a cocatalyst. One technique for preparing such modified alumoxane is disclosed in U.S. Patent No. 5,041,584, the disclosure of which is incorporated herein by reference. 3. Preparation of the active metal coordination complexes. Active catalyst species, that is, the catalysts resulting from the combination of the metal coordination complexes and an activating cocatalyst, can be prepared via any of the following techniques: A. As disclosed in U.S. patent 5,064,802 and 5,132,38, the disclosure of which is incorporated herein by reference, the metal coordination complex containing at least one substituent (preferably at least one hydrocarbyl or substituted hydrocarbyl group) is combined with the cation of a second component which is a Bronsted acid and a noncoordinating compatible anion (such as substituted ammonium salts, for example, NN-dimethylanalimium tetrakis(pentafluorophenyl)borate); B. As disclosed in PCT Application 93/23412, the disclosure of which is incorporated herein by reference, the metal coordination complex is combined with at least one second component which is a salt of a carbenium and a noncoordinating, compatible anion; C. As disclosed in U.S. Patent No. 5,189,192, the relevant portions of which are incorporated herein by reference, a reduced metal derivative of the desired metal coordination complex wherein the metal is in an oxidation state one less than that of the metal in the finished complex is combined with at least one second component which is a salt of a cationic oxidizing agent and a noncoordinating, compatible anion; D. As disdosed in U.S. Patent Application Serial No. 08/34,434, filed March 19, 1993, the relevant portions of which are incorporated herein by reference, a reduced metal derivative of the desired metal coordination complex wherein the metal is in an oxidation state one less than that of the metal in the finished complex is combined with at least one second component which is a neutral oxidizing agent (such as quinone compounds, especially bisquinones) in combination with a Lewis add mitigating agent (such as trisperfluorophenylborane); or E. As disdosed in European Patent Publication 520,732- A, the relevant portions of which are incorporated herein by reference, the metal coordination complex (preferably containing at least one hydride, hydrocarbyl or substituted hydrocarbyl group able to be abstracted by a Lewis add) is combined with a Lewis add having sufficient Lewis aridity to cause abstraction of an anionic ligand of the metal coordination complex thereby forming a cationic derivative thereof (such as tris(perfluorophenyl)-borane). 4. The Polymerization Reaction. The conditions for polymerizing the α-olefin, vinylidene aromatic, and optional diene are generally those useful in the solution polymerization process, although the application of the present invention is not limited thereto. High pressure, slurry and gas phase polymerization processes are also believed to be useful, provided the proper catalysts and polymerization conditions are employed. In general, the polymerization useful in the practice of the subject invention may be accomplished at conditions well known in the prior art for Ziegler-Natta or Kaminsky-Sinn type polymerizations. In particular, the polymerization will typically involve pressures from atmospheric up to 1000 atmospheres (100 MPa) and temperatures from 0°C to 250°C. While polymerizing and isolating the substantially random/pseudorandom interpolymer, a small amount of atactic vinylidene aromatic homopolymer may be formed due to bomopolymerization of the vinylidene aromatic monomer. In general the higher the polymerization temperature is, the higher is the amount of homopolymer formed. If desired, the vinylidene aromatic homopolymer may be at least partially separated from the substantially random/pseudorandom interpolymer, if desired, such as by extraction with a suitable extracting solvent The substantially random/pseudorandom interpolymers may be modified by typical grafting, crosslinking, hydrogenation, functionalizing, or other reactions well known to those skilled in the art, provided that the elastomeric properties of the interpolymers are not substantially affected. The polymers may be readily sulfonated or chlorinated to provide functionalized derivatives according to established techniques. Compounding and Curing the Substantially Random/Pseudorandom Interpolymers The thermoset elastomers of the invention may include various additives, such as carbon black, silica, titanium dioxide, colored pigments, clay, zinc oxide, stearic acid, accelerators, curing agents, sulfur, stabilizers, antidegradants, processing aids, adhesives, tackifiers, plasticizers, wax, precrosslinkmg inhibitors, discontinuous fibers (such as wood cellulose fibers) and extender oils. Such additives may be provided either prior to, during, or subsequent to curing the substantially random/psetidorandom interpolymers. The substantially landom/pseudorandom interpolymers are typically mixed with a filler, an oil and a curing agent at an elevated temperature to compound mem. The compounded material is the subsequently cured at a temperature which is typically greater than that employed during compounding. Preferably, carbon black will be added to the substantially random/pseudorandom interpolymer prior to curing. Carbon black is typically added to improve the tensile strength or toughness of the compounded product, but can also be used as an extender or to mask the color of the compounded product Carbon black will typically be provided in an amount from O to 80 weight percent, typically from 0.5 to 50 wright percent, based on the total weight of the foπnulation. When the carbon black is employed to mask a color, it is typically employed in the range of 0.S to 10 wdgbt percent, based on the weight of the formulation. When the carbon black is employed to increase toughness and/or decrease die cost of die formulation, it is typically employed in amounts greater than 10 weight percent based on the wdght of die formulation. Moreover, preferably, one or more extender oils will be added to the substantially random/pseudorandom interpolymer prior to curing. Extender oils are typically added to improve process-ability and low temperature flexability, as well as to decrease cost Suitable extender oils are listed in Rubber World Blue Book 1975 Edition, Materials and Compounding Ingredients for Rubber, pages 145-190. Typical classes of extender oils include aromatic, naphtbenic, and paraffinic extender oils. The extender oil(s) will typically be provided in an amount from O to 50 weight percent When employed, the extender oil will typically be provided in an amount of at least S weight percent more typically in an amount of from 15 to 25 wdght percent based on die total weight of die foπnulation. The curing agents) will typically be provided in an amount of from 0.5 to 12 weight percent based on the total weight of the formulation. Suitable curing agents include peroxides, phenols, azides, aldehyde-amine reaction products, substituted ureas, substimted guanidines; substituted xanthates; substituted dithiocarbamates; thiazoles, imidazoles, sulfenamides, thiuramidisulfides, paraquinonedioxime, dibenzoparaquinonedioxime, sulfur, and combinations thereof. See Encyclopedia of Chemical Technology, Vol. 17, 2nd edition, Intersdence Publishers, 1968; also Organic Peroxides, Daniel Seem, Vol. 1, Wiley-Intersdence, 1970). Suitable peroxides indude aromatic diacyl peroxides; aliphatic diacyl peroxides; dibasic add peroxides; ketone peroxides; alkyl peroxyesters; alkyl hydroperoxides (for example, diacetylperoxide; dibenzoylperoxide; bis-2,4-dichlorobenzoyl peroxide; di-tert-butyl peroxide; dicumylperoxide; tert- butylperbenzoate; tert-butylcumylperoxide; 2,5-bis (t-butylperoxy)-2,5-dimethylhexane; 2,5-bis (t- bulylperoxy>2^-dimemylhexyne-3; 4,4,4',4'-tetra-(t-butylperoxy)-2^-dicydohexylpropane; l,4-bis-(t- butylperoxyisopropyO-benzene; l,l-bis-<t-butylperoxy)-3,3^-trimed)ylcyc--ohexane; lauroyl peroxide; succinic acid peroxide; cydohexanone peroxide; t-butyl peracetate; butyl bydroperoxide; etc. Suitable phenols are disdosed in USP 4,311,628, the disdosure of which is incorporated herein by reference. One example of a phenolic cure agent is die condensation product of a halogen substituted phenol or a CJ-CJO altyl substituted phenol with an aldehyde in an alkaline medium, or by condensation of bifunctional phenoldialcohols. One such class of phenolic cure agents is dimethylol phenols substituted in the para position wiih C5-C 10 alkyl group(s). Also suitable are halogenated alkyl substituted phenol curing agents, and cure systems comprising methylol phenolic resin, a halogen donor, and a metal compound. Suitable azides indude azidofoπnates, such as tetramethylenebis(azidofoπnate) (see, also, USP 3,284,421, Breslow, Nov. 8, 1966); aromatic polyazides, such as 4,4'-dipbenylmedιane diazide (see, also, USP 3,297,674, Breslow et al., Jan. 10, 1967); and sulfonazides, such as p,p'-oxybis(benzene sulfonyl azide). Suitable aldehyde-amine reaction products include formaldehyde-ammonia; formaldehyde - etbylchloride-ammonia; acetaldehyde-ammonia; formaldehyde-aniline; butyraldehyde-aniline; and heptaldehyde-aniline. Suitable substituted ureas include tri ethylthiourea; diethylthiourea dibutylthiourea; tripentylthiourea; l,3-bis(2-benzothiazolylmercaptomethyl)urea; and N.N-diphenylthiourea. Suitable substituted guanidines include diphenylguanidine; di-o-tolylguanidine; diphenylguanidine phthalate; and die di-o-tolylguanidine salt of dicatecbol borate. Suitable substituted xanthates include zinc ethylxanthate; sodium isopropylxandiate; butylxanthic disulfide; potassium isopropylxandiate; and zinc butylxanthate. Suitable dithiocarbamates include copper dimethyl-, zinc dimethyl-, tellurium diediyl-, cadmium dicyclohexyl-, lead dimethyl-, lead dimethyl-, selenium dibutyl-, zinc pentamemylene-, zinc didecyl-, and zinc isopropylodyl-ditbiocaibamate. Suitable diiazoles indude 2-mercaptobenzotiιiazole, zinc mercaptothiazolyl mercaptide, 2- benzothiazolyl-N.N-diethylt-hiocarbamyl sulfide, and 2,2'-didιiobis(benzodιiazole). Suitable imidazoles include 2-mercaptoimidazoline and 2-mercapto-4,4,6- trimediyldibydropyrimidine. Suitable sulfenamides include N-t-butyl-2-benzothiazole-, N-cyclohexylbenzothiazole-, N,N- diisopropylbenzodiiazole-, N-(2,6-dimeώylmoφhdino)-2-benzothiazole-, and Ν.Ν- diethylbenzothiazole-sulfenamide. Suitable thiuramidisulfides include NN-dieύiyl-, tetrabutyl-, NN'-dϋsopropyldioctyl-. tetramethyl-, NN-dicyclohexyl-, and NN-tetratauryl-thiuramidisulfide. In the case of substantially random/pseudorandom interpolymers not including die optional diene component peroxide cure systems are preferred; in die case of substantially random/pseudorandom interpolymers including die option diene component sulfur-based (for example, containing sulfur, a dithiocarbamate, a thiazole, an imidazole, a sulfenamide, a thiuramidisulfide or combinations tiiereof) and phenolic cure systems are preferred. Preparation of Thermoplastic Vulcanizates The thermoset compositions of die invention may be incorporated into polyolefins to form thermoplastic vulcanizates. The proportions of ingredients utilized will vary somewhat with dte particular polyolefin employed, with the desired application, as wdl as with the character of the crosslinked substantially random/pseudorandom interpolymer and compounding ingredients. Typically, as the amount of die crosslinked substantially random pseudorandom interpolymer increases, the stiffness of the resultant tiieπnoplastic vulcanizate decreases. The theπnoplastic vulcanizates of the invention will typically comprise from 10 to 90 weight percent of die polyolefin and from 10 to 90 weight percent of the crosslinked substantially random/pseudorandom interpolymer. Suitable polyolefins include thermoplastic, crystalline, high molecular weight polymers prepared by the polymerization of one or more monoolefins. Examples of suitable polyolefins include ethylene and die isotacύc and syndiotactic monoolefin polymer resins, such as propylene, 1-butene, 1- pentene, 1-hexene, 2-methyl-l-propene, 3-medιyl-l-pentene, 4-methyl- 1-pentene, 5-methyl- 1-hexene and mixtures thereof. Most typically, the theπnoplastic vulcanizates of die invention will utilize isotactic polypropylene as the polyolefin component. The theπnoplastic vulcanizates of the invention are preferably prepared by dynamic vulcanization, wherein a mixture of the noncrosslinked substantially random/pseudorandom interpolymer is mixed with die polyolefin resin and an appropriate curing agent to foπn a blend, which is tiien masticated at vulcanization temperature. In particular, the noncrosslinked substantially random/pseudorandom interpolymer is blended with a polyolefin at a temperature above the melting point of die polyolefin. After die substantially random/pseudorandom interpolymer and polyolefin are intimately mixed, an appropriate curing agent is added, such as are described above with respect to the compounding and curing of die substantially random/pseudorandom interpolymers. The blend is subsequently masticated using conventional masticating equipment such as a Banbury mixer, Brabender mixer, or a mixing extruder. The temperature of the blend during mastication is that suffiάent to effect vulcanization of die substantially random pseudorandom interpolymer. A suitable range of vulcanization temperatures is from die melting temperature of die polyolefin resin ( 120°C in die case of polyediylene and 175°C in die case of polypropylene) to die temperature at which die substantially random/pseudorandom interpolymer, die polyolefin, or die curing agent degrades. Typical temperatures are from 180°C to 250°C, preferably from 180°C to 200°C. Methods other than the dynamic vulcanization of the substantially random/pseudorandom interpolymer/polyolefm are likewise suitable. For instance, die substantially random/pseudorandom interpolymer may be crosslinked prior to introduction to die polyolefin. The crosslinked substantially random/pseudorandom interpolymer may then be powdered and mixed with die polyolefin at a temperature above die melting or softening point of the polyolefin. Provided tiiat the crosslinked substantially random/pseudorandom interpolymer partides are small, well-dispersed, and in an appropriate concentration, (tiiat is, provided an intimate mixture of die crosslinked substantially random/pseudorandom interpolymer and polyolefin is achieved), die thermoplastic vulcanizates of the invention may be readily obtained. Should such an intimate mixture not be achieved, the resultant product will contain visually observable islands of the crosslinked substantially random/pseudorandom interpolymer. In mis case, die part may be comminuted by pulverizing or by cold milling to reduce particle size to below SO microns. Upon adequate comminution, die partides may be remolded into a part exhibiting more uniform composition and the enhanced properties characteristic of the thermoplastic vulcanizates of the invention. The thermoplastic vulcanizates of the invention may include various additives, such as carbon black, silica, titanium dioxide, colored pigments, clay, zinc oxide, stearic acid, accelerators, vulcanizing agents, sulfur, stabilizers, antidegradants, processing aids, adhesives, tackifiers, plastiάzers, wax, prevulcanization inhibitors, discontinuous fibers (such as wood cellulose fibers) and extender oils. Such additives may be provided either prior to, during, or subsequent to vulcanization. As in the case of die thermoset elastomers of die invention, carbon black will preferably be added to die blend of die substantially random pseudorandom interpolymer and polyolefin prior to vulcanization. Carbon black will typically be provided in an amount from 0 to 50 wdght percent typically from 0.5 to SO weight percent based on the total formulation wdght. When die carbon black is employed to mask a color, it is typically employed in the range of 0.5 to 10 wdght percent based on the total wdght of die formulation. When die carbon black is employed to increase toughness and/or decrease cost it is typically employed in amounts greater tiian 10 weight percent based on die total weight of the formulation. Moreover, as in the case of the ihermoset elastomers of the invention, one or more extender oils will preferably be added to t-be blend of die substantially random/pseudorandom interpolymer and polyolefin prior to vulcanization. Suitable extender oils are listed in Rubber World Blue Book 1975 Edition, Materials and Compounding Ingredients for Rubber, pages 145-190. Typical classes of extender oils indude aromatic, naphdienic, and paraffinic extender oils. The extender oil(s) will typically be provided in an amount from 0 to 50 weight percent based on the total formulation weight When employed, the extender oil will typically be provided in an amount of at least S weight percent more typically in an amount of from 15 to 25 weight percent based on the total weight of the formulation. In one preferred embodiment die theπnoplastic vulcanizates of the invention will comprise from 30 to 60 weight percent of the substanti ly random pseudorandom interpolymer, from 15 to 55 weight percent of the thermoplastic polyolefin, and from 15 to 30 wdght percent of die extender oil. Such thermoplastic vulcanizates are particularly useful as moldings for automotive applications. In a particularly preferred embodiment e theπnoplastic vulcanizates of die invention are characterized by an ASTM #2 oil swell of less than 60 percent as determined by ASTM D-471. Test Procedures Monomer contents are determined by carbon- 13 NMR spectroscopy. Stress-strain properties are determined on an Instron model 1122 load frame using 0.870 inch (2.2 cm) micro-tensile samples measured at an extension rate of 5 inch/min (12.7 cm/min). Tensile break, elongation at break, and 100 percent modulus are measured in accordance with ASTM D-412. Melt index is measured in accordance with ASTM D-1238. Molecular wdght and molecular weight distribution are determined by gel permeation chromatography. ASTM #2 and #3 oil swells are measured in accordance with ASTM D-471. Hardness snore "A" is measured in accordance with ASTM D-2240. Compression set is measured in accordance with ASTM D-395. Example One: Preparation of Ethylene-Styrene Interpolymers and Thermoset Elastomers Ethylene/styrene copolymers were made using (tert-butylamido)dimedιyl(tetramethyl-ηS- cyckφenta-dienyl)silane dimethyltitanium(+4) catalyst and tris(pentafluorophenyl)borane cocatalyst in a one to one ratio according to the following procedure. A two liter reactor was charged with 360 grams ( 500 mL) of ISOPAR™ E mixed alkane solvent (available from Exxon Chemicals Inc.) and die desired amount of styrene comonomer. Hydrogen was added to die reactor by differential pressure expansion from a 75 mL addition tank. The reactor was heated to the run temperature and was saturated with ethylene at the desired pressure. (Tert-butylamido)d memyl-(tetrameώyl-η5-<^clc*pe«tadi-enyl)silane dimet-hyltitanium (TV) catalyst and tris(pentafluorophenyl)borane cocatalyst were mixed in a dry box by pipeting die desired amount of a 0.005 M solution of the tris(pentafluorophenyl)borane cocatalyst in ISOPAR™ E mixed alkane solvent or toluene into a solution of die (tert-butylamido)dimethyl- (tetramethyl-ηS-cydopentadieny silane dimethyl-titanium (IV) catalyst in ISOPAR™ E mixed alkane solvent or toluene. The resulting catalyst solution was transferred to a catalyst addition tank and was injected into die reactor. The polymerization was allowed to proceed, with ethylene being introduced on demand. Additional charges of catalyst and cocatalyst if used, were prepared in die same manner and were added to die reactor periodically. The total amount of catalyst employed was set forth in Table One. In each instance, die amount of tris(pentafluorophenyl)borane cocatalyst (on a molar basis) equals die amount of (tert-butylamido)dimethyl-(tetrameύιyl-η5-cyclopentadienyl)silane dime ylϋtanium (TV) catalyst indicated in Table One. After die run time, die polymer solution was removed from die reactor and quenched with isopropyl alcohol. A hindered phenol antioxidant (IRGANOX™ 1010 (available from Ciba Geigy Corp.) was added to die polymer. Volatiles were removed from the polymer in a reduced pressure vacuum oven at 135°C for 20 hours. The resultant substantially random interpolymers were characterized as being pseudorandom and linear. The interpolymers were compounded and cured according to the following procedure. The 60 gram bowl of a Brabender PS-2 internal mixer was preheated to 120°F. 100 pph carbon black N5S0 (available from Cabot Corporation), 50 pph SUNPAR™ 2280 oil (available from Sun Oil), 5 pph paraffin wax, 1 pph stearic acid, 8 pph Vul-Cup 40KE peroxide (available from Hercules) and 1.5 pph triallyl cyanurate coagent (available from American Cyanamid) were premixed in a plastic or paper container. The resultant blend was loaded into die 60 gram bowl. To die bowl was further added 100 pph of the desired substantially random/pseudorandom interpolymer as prepared above. The ram was lowered on die internal mixer, and die compound was allowed to mix until a temperature of 220°F was reached (approximately five minutes). The compound was removed from the mixer and was optionally roll-milled. The samples were compression molded at 260°F to obtain uncured (green) test plaques. The uncured (green) test plaques were compression mold cured at 340°F for 20 minutes to obtain crosslinked dieπnoset elastomer compositions. The stress-strain properties of die neat interpolymers, of die uncured (green) test plaques, and of the crosslinked thermoset elastomer compositions were set forth in Table Two. Therein, the designation "ND" means that the given property was not determined. As illustrated in Table Two, die crosslinked dieπnoset elastomer compositions of me invention exhibit a higher 100 % modulus than the comparative materials Cl (Tafmer™ 680-P (available from Mitsui Petrochemical)) and C2 (Vistalon™ 457 (available from Exxon Chemical Co.)). This was consistent with the significantly higher 100 % modulus exhibited by die neat interpolymers as compared to die comparative materials. Example Two: Preparation of Ethylene/Styrene/Ethylidene Norbomene Interpolymers and Thermoset Elastomers Ethylene/styrene/ediylidene norbomene interpolymers were made using (tert- butylanύdo)dimedιyl(tet-ra-medιyl-ηS-cyclopenta-di-enyl)si]ane dimethylύtanium(-t4) catalyst and tris(pentafiuorophenyl)borane cocatalyst in a one to one ratio according to die following procedure. A two liter reactor was charged witii 360 grams ( 500 mL) of ISOPAR™ E mixed alkane solvent (available from Exxon Chemicals Inc.) and die desired amount of styrene comonomer. Ethylidene norbornene was transferred to the reactor. Hydrogen was added to the reactor by differential pressure expansion from a 75 mL addition tank. The reactor was heated to die run temperature and was saturated with ethylene at the desired pressure. (Tert-butylamido)dimethyl-(tetramethyl-η5- cyclopentadienyl)silane dimediyltitanium (TV) catalyst and tris(pentafluoro-phenyl)borane cocatalyst were mixed in a dry box by pipeting the desired amount of a 0.005 M solution of me tris(pentafluorophenyl)borane cocatalyst in ISOPAR™ E mixed alkane solvent or toluene into a solution of die (tert-butyla-αύdo)dimemyI-(tetrameωyl-η5-cyclopentadienyl)silane dimemyl-titanium (IV) catalyst in ISOPAR™ E mixed alkane solvent or toluene. The resulting catalyst solution was transferred to a catalyst addition tank and was injected into die reactor. The polymerization was allowed to proceed, with ethylene being introduced on demand. Additional charges of catalyst and cocatalyst if used, were prepared in die same manner and were added to die reactor periodically. The total amount of catalyst employed was reported in Table Three. In each instance, die amount of tris(pentafluoro-phenyl)borane cocatalyst (on a molar basis) was equal to that of the (tert-butylamido)dimeωyl-(tetramemyl-η5-cyclopen'-adienyl)si-ώne dimediyltitanium (TV) catalyst as indicated in Table Three. After the run time, the polymer solution was removed from the reactor and quenched with isopropyl alcohol. A hindered phenol anύoxidant (IRGANOX™ 1010 (available from Ciba Geigy Corp.) was added to t-he polymer. Volatiles were removed from me polymer in a reduced pressure vacuum oven at 135°C for 20 hours. The preparation conditions for the ediylene styrene/ethylidene norbomene interpolymers were set forth in Table Three. Sample Catalyst ISOPAR Styrene ENB Ethylene Hydrogen Reaction Reaction Yeild amount -E (mL) (mL) amount pressure (psi) Temp Time (β) (-mol) (mL) (psi*) (C) (min) ES-1 15 500 500 50 250 100 65 20 149.9 ES-2 12.5 500 500 75 300 100 65 30 120.7 ES-3 10 500 500 25 200 100 65 30 135.1 The resultant substantially random interpolymers were characterized as being pseudorandom and linear. The interpolymers were compounded and cured according to the following procedure. The 60 gram bowl of a Brabender PS-2 internal mixer was preheated to 120°F. 100 pph carbon black N550 (available from Cabot), 50 pph SUNPARTM 2280 oil (available from Sun Oil), 5 pph paraffin wax, 1 pph stearic acid, 5 pph zinc oxide, 1.5 pph sulfur, and 0.5 pph Captax 2-mercaptobenzothiazoIe (available from R. T. Vanderbilt) were premixed in a plastic or paper container. The resultant blend was loaded into die 60 gram bowl. To the bowl was further added 100 pph of die desired interpolymer as prepared above. The ram was lowered on the internal mixer, and the compound was allowed to mix until a temperature of 220°F was reached (approximately five minutes). The compound was removed from the mixer and was optionally roll-milled. The samples were compression molded at 260°F to obtain uncured (green) test plaques. The uncured (green) test plaques were compression mold cured at 340°F for 20 minutes to obtain crosslinked thermoset elastomer compositions. As between ESDMl(a)-(d), ESDMl(a) was prepared in accordance witii die above formulation. ESDMl(b)-(d) were likewise prepared in accordance with die above formulation, except that in die case of ESDMl(b), SO pph SUNDEX 750T oil (available from Sun Oil), was used in place of die SUNPAR oil; in die case of ESDMl(c), 50 pph trioctyltrimelliate was used in place of die SUNPAR oil; and in the case of ESDMl(d), 0.75 pph (ratber than 1.5 pph) sulfur was employed. Regarding the comparative materials, C4 was prepared using the formulation provided above, widi Vistalon 6505 EPDM (available from Exxon) being used in place of the substantially random/pseudorandom interpolymer. C5 was prepared using die foπnulation provided above, with EPSyn 70A EPDM (available from DSM Copolymer) being used in place of the substantially random/pseudorandom interpolymer used in die present invention. C6(a) was prepared using die foπnulation provided above, witii SBR 1500 styrene butadiene rubber being used in place of the substantially random/pseudorandom interpolymers and Sundex 750T oil (available from Sun Oil) being used in place of the SUNPAR oil. C6(b) was prepared using die formulation provided above, except tiiat SBR 1500 styrene butadiene rubber was used in place of the substantially random/pseudorandom interpolymer, 50 pph (ratiier than 100 pph) N550 carbon black was employed, 7 pph Sundex 750T oil (rather tiian 50 pph SUNPAR 2280 oil) was employed. The stress-strain properties of the neat interpolymers, of the uncured (green) test plaques, and of die crosslinked r-hermoset elastomer compositions were set forth in Table Four. Therein, die abbreviation "ND" means that a given property was not determined. As illustrated in Table Four, the crosslinked thermoset elastomers of the invention typically exhibit a highly improved 100% modulus, as compared to comparative materials C4 (VistalonTM 6505 EPDM (available from Exxon)), C5 OΞPSyn 70A EPDM (available from DSM Copolymer)) and C6 (SBR 1500 styrene-butadiene rubber). As further illustrated in Table Four, the crosslinked diermoset elastomers of the invention typically exhibit a resistance to oil swell similar to that of styrene-butadiene-rubber, but superior to that of EPDM materials. As further illustrated in Table Four, the crosslinked diermoset elastomers of the invention exhibit aging properties superior to those of styrene-butadiene rubber. For instance, upon aging at 250°F for 70 hours in an air oven, die crosslinked ethylene/styrene/et-bylidene norbomene interpolymer exhibited increased tensile at break values and moderately decreased elongation at break values. In contrast upon oven aging under die same conditions, d e styrene-butadiene rubbers exhibited decreased tensile at break values and significantly decreased elongation at break values. Thus, as illustrated in Table Four, the crosslinked ediylene/styrene/diene thermoset elastomers of die invention exhibit a resistance to oil swell characteristic of styrene-butadiene rubber widiout suffering the concomitant negative effects of heat aging. Example Three: Preparation of Thermoplastic Vulcanizates The Brabender PS-2 or Haake internal torque mixer was preheated to 350°C. The desired amount of Pro-fax 6524 isotactic polypropylene (available from Himont Incorporated) was added to the mixer, and was allowed to melt and to homogenize. Over one minute, die desired amount of the noncrosslinked substantially random pseudorandom interpolymer was added. Thereafter, the process oil, antioxidant stearic add, and carbon black were added and mixed for one minute. The zinc oxide, sulfur, benzothiazyldisulfide and metiiyl tuads were added. Mixing occurs until the torque reaches a maximum and for at least 10 minutes total mix time. The resultant thermoplastic vulcanizate was removed from the mixer. In executing die above procedure, the formulations set forth in Table Five were employed. Unless otherwise indicated, all amounts were expressed in parts per hundred, based on 100 parts of the elastomer. Except in die case of TPV 1(b), SunParTM 2280 (available from Sun Oil) was employed as die process oil. For TPV 1(b), trioctyltrimelliate was employed as die process oil. The resultant thermoplastic vulcanizates were compression molded at 380°F. Representative physical properties of the dieπnoplastic vulcanizates and of comparative thermoplastic vulcanizates C- TPV1 (made witii Vistalon 6505 EPDM (available from Exxon)) and C-TPV2 (made widi EPSyn 70A EPDM (available from DSM Rubber)) were set forth in Table Six. Therein, the abbreviation "ND" means mat a given property was not determined. A comparison of TPV 1(a) and TPV2(a) widi comparative materials C-TPV1 (made witii Vistalon 6505 EPDM (available from Exxon)) and C-TPV2 (made with EPSyn 70A EPDM (available from DSM Rubber)) indicates that the dieπnoplastic vulcanizates of the invention exhibit a much greater resistance to oil swell (under die ASTM #2 test method) than die comparative materials without sacrifidng hardness (Hardness Shore "A"). A comparison of these materials further indicates tiiat die thermoplastic vulcanizates of die invention exhibit improved 100% modulus values and comparable tensile at break values, with respect to die comparative materials. A comparison of TPV-2(b), TPV-2(c), and TPV-2(d) indicates that one can adjust resistance to ASTM #2 oil swell and hardness values by adjusting die ratio between die polypropylene and die substantiaUy random/pseudorandom interpolymer. Namely, as the proportion of the polypropylene increases, die resistance to ASTM #2 oil swell and hardness likewise increase. Moreover, the effeα of the added substantially random pseudorandom interpolymer was evident In particular, the percent elongation at break of die inventive dieπnoplastic vulcanizates was many times greater than that of unmodified isotactic polypropylene, which exhibits a percent elongation at break of 13 percent The thermoset elastomers of the invention were useful in a variety of applications. Exemplary applications include noses, air ducts, brake cups, roofing materials, as well as use as components in blends as impact modifiers and in general molded goods. The thermoplastic vulcanizates were likewise useful in a variety of applications, particularly articles made by extrusion, injection molding and compression molding techniques. One principal application for the TPVS of the invention was in automotive under-the-hood components, such as rack- and-pinion boots and ducting, fuel-line covers, hoses, belts, and gaskets. Other expected automotive applications were in interior applications (such as skins, instrument panels, air-bag covers, door trim, control knobs, molded parts, and seat belt covers) and exterior applications (such as tires and molding).

Claims: CLAIMS 1. A thermoset elastomer comprising eidier ( 1 ) a crosslinked pseudorandom interpolymer of: (a) from 15 to 70 weight percent of at least one α-olefin, (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (c) from 0 to 15 weight percent of at least one diene; or (2) a crosslinked substantially random interpolymer of: (a) from 15 to 70 weight percent of at least one α-olefin, (b) from 30 to 70 wdght percent of at least one vinylidene aromatic compound, and (c) from 0 to 15 weight percent of at least one diene. 2. The thermoset elastomer of Claim 1 comprising eidier (1) a crosslinked pseudorandom interpolymer of (a) from 25 to 60 weight percent of at least one α-olefin, (b) from 35 to 60 wdght percent of at least one vinylidene aromatic compound, and (c) from 3 to 15 wdght percent of at least one diene, or (2) a crosslinked substantially random interpolymer of (a) from 25 to 60 weight percent of at least one α-olefin, (b) from 35 to 60 weight percent of at least one vinylidene aromatic compound, and (c) from 3 to 15 weight percent of at least one diene, or (2) a crosslinked substantially random interpolymer of. 3. The thermoset elastomer of Claim 1 comprising either ( 1 ) a crosslinked pseudorandom interpolymer of: (a) from 40 to 65 wdght percent of at least one α-olefin selected from the group consisting of ediylene, propylene, 1-butene, 3-methyl-l-butene, 1-pentene, 4-methyl-l-pentene, 1-hexene, 5-methyl-l-hexene, 4-ethyl-l-hexene, 1-octene, 1-dodecene, 3-phenylpropene, and mixtures thereof; and (b) from 35 to 60 weight percent of at least one vinylidene aromatic compound selected from the group consisting of styrene, α-methylstyrene, ortho-methylstyrene, meta-methylstyrene, para-mediylstyrene, dilorostyrene, vinylbenzocyclobutane, and divinylbenzene, and mixtures thereof; or (2) a crosslinked substantially random interpolymer of: (a) from 40 to 65 weight percent of at least one α-olefin selected from the group consisting of ediylene, propylene, 1-butene, 3-methyl-l-butene, 1-pentene, 4-methyl-l-pentene, 1-hexene, 5-methyl-l-hexene, 4-edιyl- 1-hexene, 1-octene, 1-dodecene, 3-phenylpropene, and mixtures thereof; and (b) from 35 to 60 weight percent of at least one vinylidene aromatic compound selected from the group consisting of styrene, α-methylstyrene, ortho-mediylstyrene, meta-memylst-yrene, para-methylstyrene, chlorostyrene, vinylbenzocyclobutane, and divinylbenzene, and mixtures thereof. 4. The thermoset elastomer of Claim 1 , 2, or 3 wherein (a) die α-olefin is selected from the group consisting of ethylene, propylene, 1-butene, 3-metiιyl-l- butene, 1-pentene, 4-meωyl- 1-pentene, 1-hexene, 5-methyl-l-hexene, 4-ethyI-l-hexene, 1-octene, 1-dodecene, 3-phenylpropene, and mixtures diereof; (b) the vinylidene aromatic compound is selected from the group consisting of styrene, α- metiiylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, chlorostyrene, vinylbenzocyclobutane, and divinylbenzene, and mixtures diereof; and (c) die diene, when present is selected from die group consisting of butadiene, 1 ,3-pentadiene, 1 ,4- pentadiene, isoprene, 1,4-hexadiene, 7-methyl-l,6-octadiene, dicyclopentadiene, memylenenorbornene, ethylidenenorbornene, and mediyltetrahydroindene, and mixtures diereof. 5. The thermoset elastomer of Claim 4, wherein the α-olefin is ediylene, die vinylidene aromatic compound is styrene, and the diene, when present is ethylidenenorbomene. 6. A process for preparing a thermoset elastomer comprising: (a) reacting at least one α-olefin widi at least (me vinylidene aromatic compound and optionally at least one diene, in the presence of a constrained geometry catalyst to form a pseudorandom interpolymer, (b) curing the pseudorandom interpolymer to form a diermoset elastomer. 7. The process of Claim 6, wherein the constrained geometry catalyst comprises a metal coordination complex comprising a metal of Group m or TV or the Land anide series of the Periodic Table of the Elements and a delocalized Tl -bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry the metal atom such that the angle at die metal between die centroid of die delocalized, substituted Il-bonded moiety and die center of at least one remaining substituent is less than such angle in a similar complex containing a similar π-bonded moiety lacking in sudi constrain-inducing substituent and provided further that for such complexes comprising more than one delocalized, substituted x-bonded moiety, only one diereof for each metal atom of the complex is a cyclic delocalized, substituted π -bonded moiety. 8. The process of Claim 6, wherein the constrained geometry catalyst is selected from the group consisting of (tert-butylamidoXtetramethyl-η5-cyclopent-adienyl)-l,2-ethanediylzirconium dichloride; (tert-butylamido) (teu * amethyl-η5-cycloρentadienyl)-l,2-ethanediyl titanium dichloride; (tert- butylamido)dimedιyl(tetramedιyl-η5-cyclopentadienyl) silanetitanium dimethyl; (tert- butylamido)diιnedιyl(tetramedιyl-η5-indenyl) silanetitanium dimethyl; (tert- butylamido)dimethyl(tetramethyl-η5-tetrahydroindenyl) silanetitanium dimethyl; (tert- butylamido)di-meώyl(tetramedιyl-ηS-fluroenyl) silanetitanium dimethyl; (tert- butylan.ύdo)d---medιyl(tel-ramedιyl-η5-tetrahydrofluorenyl) silanetitanium dimethyl; (tert- butylanύdo)dimemyl(tetrame yl-ηS-octahydrofluorenyl) silanetitanium dimethyl; (tert- butylaιm^)dimedιyl(teiramethyl-ηS-cydopentadienyl) silanetitanium dibenzyl; (tert- butylamido)dimediyl (tetramethyl-η5-cyclopentadienyl)silanezirconium dibenzyl; and mixtures diereof. 9. The process of Claim 7, wherein the constrained geometry catalyst is activated by a cocatalyst selected from the group consisting of polymeric alumoxanes, oligomeric alumoxanes, polymeric carbylboranes, oligomeric carbylboranes, monomeric caibylboranes, aluminum alkyls, aluminum halides, haloaluminum alkyls, substituted ammonium salts, silver salts, ferrocenium ions, and mixtures diereof. 10. The process of Claim 7, wherein die constrained geometry catalyst is activated by tris(pentafluorophenyl)borane. 11. The process Claim 6, wherein the curing is effected by a curing agent selected from the group consisting of peroxides, phenols, azides, aldehyde -amine reaction products, substituted ureas, substituted guanidines, substituted xanthates, substituted dithiocaibamates, thiazoles, imidazoles, sulfenamides, thiuramidisulfides, paraquinonedioxime, dibenzoparaquinonedioxime, and sulfur. 12. The process of Claim 6, wherein die curing is effected by a curing agent selected from the group consisting of peroxides, phenols, substituted ditiiiocarbamates, thiazoles, imidazoles, sulfenamides, tiύuramidisulfides, sulfur and mixtures thereo and sulfur. 13. The process of Claim 6, wherein die curing is effected simultaneously widi die compounding of die pseudorandom interpolymer. 14. A process for preparing a thermoset elastomer comprising: (a) reacting at least one α-olefin widi at least one vinylidene aromatic compound and optionally at least one diene, in die presence of a constrained geometry catalyst to foπn a substantially random interpolymer, (b) curing die substantially random interpolymer to form a thermoset elastomer. 15. The process of Claim 6,7, 8, 9, 10, 11, 12, 13 or 14, wherein (i) die α-olefin is selected from die group consisting of ediylene, propylene, 1-butene, 1-pentene, 1- hexene, 4-methyl-l-pentene, 5-methyl-l-hexene, 4-ethyl- 1-hexene, 1-octene, 3-phenylpropene, and mixtures diereof; (ii) die vinylidene aromatic compound is selected from the groups consisting of styrene, α- methylstyrene, ortbo-methylstyrene, meta-mediylstyrene, para-met-bylstyrene, chlorostyrene, vinylbenzocyclobutane, divinylbenzene, and mixtures diereof; and (iii) the diene, when present is sdected from die group consisting of butadiene, 1 ,3-pentadiene, 1,4- pentadiene, isoprene, 1,4-bexadiene, 7-medιyl-l,6-octadiene, dicyclopentadiene, mediylenenorbornene, ethylidenenorbornene, and mixtures thereof. 16. A thermoplastic vulcanizate comprising: (a) a crosslinked pseudorandom interpolymer of (i) from IS to 70 weight percent of at least one α-olefin, (ii) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (iii) from 0 to 15 weight percent of at least one diene; and (b) at least one thermoplastic polyolefin. 17. The thermoplastic vulcanizate of Claim 16, comprising from 10 to 90 wdght percent of die crosslinked pseudorandom interpolymer and from 10 to 90 weight percent of the thermoplastic polyolefin. 18. The thermoplastic vulcanizate of Claim 16, further comprising from 0 to 50 wdght percent of an extender oil selected from the group consisting of aromatic oils, naphthenic oils, and paraffinic oils. 19. The thermoplastic vulcanizate of Claim 16, wherein die crosslinked pseudorandom interpolymer is an interpolymer of (a) from 40 to 65 weight percent of at least one α- oleftn, and (b) from 35 to 60 weight percent of at least one vinylidene aromatic compound. 20. The thermoplastic vulcanizate of Claim 18, wherein the crosslinked pseudorandom interpolymer is an interpolymer of (a) from 25 to 60 weight percent of at least one α- olefin, (b) from 35 to 60 weight percent of at least one vinylidene aromatic compound, and (c) from 3 to 15 weight percent of at least one diene. 21. The thermoplastic vulcanizate of Claim 16, comprising from 30 to 60 weight percent of the crosslinked pseudorandom interpolymer, from 15 to 55 weight percent of me thermoplastic polyolefin, and from 15 to 30 weight percent of die extender oil. 22. A dieπnoplastic vulcanizate comprising: (a) a crosslinked substantially random interpolymer of (i) from 15 to 70 weight percent of at least one α-olefin, (ii) from 30 to 70 weight percent of at least one vinylidene aromatic compound, and (iii) from 0 to 15 weight percent of at least one diene; and (b) at least one thermoplastic polyolefin. 23. The dieπnoplastic vulcanizate of Claim 16, 17, 18, 19, 20, 21 or 22, wherein: (a) die α-olefin is selected from die group consisting of ethylene, propylene, 1-butene, 1-pentene, 1- bexene, 4-methyl-l-pentene, 5-metiιyl- 1-hexene, 4-ethyl- 1-hexene, 1-octene, 3-phenylpropene, and mixtures diereof; (b) the vinylidene aromatic compound is selected from the group consisting of styrene, α- metbylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, chlorostyrene, vinylbenzocyclobutane, divinylbenzene, and mixtures diereof; and (c) die optional diene is selected from die group consisting of butadiene, 1,3-pentadiene, 1,4- pentadiene, isoprene, 1,4-hexadiene, 7 -methyl- 1,6-octadiene, dicyclopentadiene, methylenenorbomene, ethylidenenoibornene, methyltetrahydroindene, and mixtures thereof. 24. The thermoplastic vulcanizate of Claim 23, wherein die dwnnoplastic polyolefin is selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-l- propene, 3-methyl- 1 -pentene, 4-methyl- 1 -pentene, 5-methyl- 1 -hexene, and mixtures diereof. 25. The diermoplastic vulcanizate of Claim 23, wherein the α-olefin is ediylene, die vinylidene aromatic compound is styrene, and the diene, when present is etbylidenenot-boraene. 26. The dieπnoplastic vulcanizate of Claim 24, wherein die α-olefin is ediylene, die vinylidene aromatic compound is styrene, and die diene, when present is ethylidenenorboπiene. 27. A thermoplastic vulcanizate comprising a crosslinked substantially random interpolymer of at least one α-olefin, at least one vinylidene aromatic compound and optionally at least one diene distributed in a thermoplastic polyolefin matrix, said thermoplastic vulcanizate being characterized by an ASTM #2 oil swell of less dian 60 percent as determined by ASTM D-471. 28. A process for making a dieπnoplastic vulcanizate comprising: (a) reacting at least one α-olefin with at least one vinylidene aromatic compound and optionally at least one diene in die presence of a constrained geometry catalyst to form a pseudorandom interpolymer; (b) intimately mixing die pseudorandom interpolymer with at least one theπnoplastic polyolefin at a temperature above the melting or softening point of the theπnoplastic polyolefin; (c) providing to die intimate mixture an agent for curing die pseudorandom interpolymer; (d) simultaneously curing the pseudorandom interpolymer and compounding the intimate mixture to foπn a thermoplastic vulcanizate. 29. The process of Claim 28, wherein (i) die α-olefin is selected from the group consisting of ediylene, propylene, 1-butene, 1-pentene, 1- hexene, 4-methyl-l-pentene, 5-methyl-l-hexene, 4-ethyl- 1-hexene, 1-octene, 3-phenylpropene, and mixtures diereof; (ii) die vinylidene aromatic compound is selected from the group consisting of styrene, α- methylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, chlorostyrene, vinylbenzocyclobutane, divinylbenzene, and mixtures diereof; and (iii) the optional diene is selected from the group consisting of butadiene, 1,3-pentadiene, 1,4 pentadiene, isoprene, 1,4-hexadiene, 7-methyl-l,6-octadiene, dicyclopentadiene, memylenenorbornene, etbylidenenorbornene, methyltetrahydroindene, and mixtures thereof. 30. The process of Claim 28, wherein the theπnoplastic polyolefin is selected from the group consisting of ediylene, propylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-l-propene, 3- methyl-1 -pentene, 4-methyl-l-pentene, 5-methyl-l-hexene, and mixtures diereof. 31. The process of Claim 28, wherein die agent for curing the substantially random interpolymer is selected from die group consisting of peroxides, phenols, azides, aldehyde - amine reaction products, substituted ureas, substituted guanidines, substituted xandiates, substituted dithiocarbamates, thiazoles, imidazoles, sulfenamides, diiuramidisulfides, paraquinonedioxime, dibenzoparaquinonedioxime, sulfur, and mixtures thereof. 32. The process of Claim 28, 29, 30 or 31, wherein the constrained geometry catalyst comprises a metal coordination complex comprising a metal of Group III or IV or the Lantiianide series of die Periodic Table of the Elements and a delocalized π-bonded moiety substituted with a constrain-inducing moiety, said complex having a constrained geometry the metal atom such tiiat the angle at the metal between the centroid of the delocalized, substituted π-bonded moidy and die center of at least one remaining substituent is less than such angle in a similar complex containing a similar π-bonded moiety lacking in such constrain-indudng substituent and provided further that for such complexes comprising more than one delocalized, substituted x-bonded moiety, only one thereof for each metal atom of the complex is a cyclic, delocalized, substituted π-bonded moiety. 33. The process of Claim 32, wherein the constrained geometry catalyst is activated by a cocatalyst selected from the group consisting of polymeric alumoxanes, oligomeric alumoxanes, polymeric carbylboranes, oligomeric carbylboranes, monomeric carbylboranes, aluminum alkyls, aluminum halides, haloaluminum alkyls, ammonium salts, silver salts, ferrocenium ions, and mixtures thereof. 34. A process for making a theπnoplastic vulcanizate comprising: (a) reacting at least one α-olefin widi at least one vinylidene aromatic compound and optionally at least one diene in die presence of a constrained geometry catalyst to form a substantially random interpolymer, (b) intimatdy mixing die substantially random interpolymer with at least one diermoplastic polyolefin at a temperature above the melting or softening point of the thermoplastic polyolefin; (c) providing to the intimate mixture an agent for curing die substantially random interpolymer; (d) simultaneously curing the substantially random interpolymer and compounding die intimate mixture to foπn a diermoplastic vulcanizate. 35. A fabricated part comprising a crosslinked pseudorandom interpolymer of: (a) from IS to 70 weight percent of at least one α-olefin selected from me group consisting of ethylene, propylene, 1-butene,, 1-pentene, 1-hexene, 4-meωyl- 1-pentene, 5-methyl-l-hexene, 4- ethyl- 1-hexene, 1-octene, 3-phenylpropene, and mixtures diereof; (b) from 30 to 70 weight percent of at least one vinylidene aromatic compound selected from the groups consisting of styrene, α-methylstyrene, ortho-methylstyrene, meta-methylstyrene, para- meωylstyrene, chlorostyrene, vinylbenzocyclobutane, divinylbenzene, and mixtures thereof; (c) rom O to 15 weight percent of at least one diene selected from die group consisting of butadiene, 1,3-pentadiene, 1,4 pentadiene, isoprene, 1,4-hexadiene, 7-methyl-l,6-octadiene, dicyclopentadiene, methylenenorbornene, ethylidenenorbornene, methyltetrahydroindene, and mixtures thereof. 36. A fabricated pan comprising a thermoplastic vulcanizate comprising (a) from 10 to 90 weight percent of a crosslinked substantially random interpolymer of (i) from 15 to 70 weight percent of at least one α-olefin selected from die group consisting of ediylene, propylene, l-butene„ 1-pentene, 1-hexene, 4-methyl-l-pentene, 5-methyl-l- hexene, 4-ethyI- 1-hexene, 1-octene, 3-phenylpropene, and mixtures thereof; (ii) from 30 to 70 weight percent of at least one vinylidene aromatic compound selected from die groups consisting of styrene, α-methylstyrene, ortho-methylstyrene, meta- methylstyrene, para-methylstyrene, chlorostyrene, vinylbenzocyclobutane, divinylbenzene, and mixtures thereof; and (iii) from 0 to 15 weight percent of at least one diene selected from the group consisting of butadiene, 1 ,3-pentadiene, 1,4 pentadiene, isoprene, 1,4-hexadiene, 7-medιyl-l,6-octadiene, dicyclopentadiene, methylenenorbornene, ediylidenenorbomene, meωyltetrahydroindene, and mixtures thereof; and (b) from 10 to 90 weight percent of at least one diermoplastic polyolefin selected from the group consisting of ediylene, propylene, 1-butene, 1-pentene, 1-hexene, 2-methyI-l-propene, 3-methyl-l- pentene, 4-memyl- 1-pentene, 5-medιyl- 1-hexene, and mixtures diereof.

Inventors: FEIG EDWARD R, MCKAY KEVIN W, TIMMERS FRANCIS J, FEIG, EDWARD, R., MCKAY, KEVIN, W., TIMMERS, FRANCIS, J.
Applicants: DOW CHEMICAL CO, THE DOW CHEMICAL COMPANY
Application year: 1995
Main classification: C08F212
IPC codes: C08F4, C08F10, C08F210, C08F212, C08J3, C08J5, C08L23, C08L25, C08L53