Process for production of high molecular weight EPDM elastomers using a metallocene-alumoxane catalyst system

Claim 1

A process for producing an EPDM elastomer, comprising: adding an α-olefin monomer in which an EPDM elastomer is substantially insoluble to a reaction vessel in an amount and under pressure sufficient to allow utilization of said α-olefin in liquified form as a polymerization diluent; supplying diene monomer to said diluent; adding ethylene to said diluent in an amount sufficient to maintain a desired ethylene/α-olefin ratio in the liquid phase of the reaction vessel; and, adding to said diluent a metallocene-alumoxane catalyst system wherein the metallocene component of the catalyst is of the formula: wherein "M" is titanium, zirconium or hafnium; each "R¹" independently is a C₁ to C₂₀ linear, branched or cyclic alkyl group or a C₂ to C₄ alkylene which forms a fused ring system; "R²" is a C₁ to C₆ linear, branched or cyclic alkylene group, an alkyl substituted silanylene group or an alkyl substituted silaalkylene group; each "X" Independently is a halogen, hydride, hydrocarbyl radical or chelating group, and "y" is an integer of 2, 3 or 4; reacting the mixture of monomers for a time sufficient to permit polymerization of said ethylene, α-olefln, and diene monomers to an EPDM elastomer having either a weight-average molecular weight greater than 110,000 or a Mooney viscosity (ML₁₊₈ at 127°C) greater than 10.