04871705 is referenced by 224 patents and cites 4 patents.

Disclosed is a process for preparing high molecular weight ethylene-.alpha.-olefin elastomers, preferably an ethylene-propylene elastomer, by liquid phase polymerization of the requisite monomers in the presence of a metallocene/alumoxane catalyst system. Preferably, the process is carried out as a slurry polymerization utilizing the metallocene/alumoxane catalyst in supported form on a silica gel support with the .alpha.-olefin monomer maintained in liquid state and used in excess to serve as a polymerization diluent. The metallocene component of the catalyst by which the process is practiced is of the formula: ##STR1## wherein M is zirconium, titanium or hafnium; each R.sup.1 independently is a C.sub.1 -C.sub.20 linear, branched or cyclic alkyl group or a C.sub.2 -C.sub.4 cyclic alkylene group which forms a fused ring system group; R.sup.2 is a C.sub.1 -C.sub.6 linear, branched or cyclic alkylene, a Si.sub.1 -Si.sub.2 alkyl substituted silanylene group or an alkyl substituted silaalkylene group; each X independently is an alkyl, aryl, halide, hydride or oxygen bridge of a zirconocene dimer; "y" is a number 2, 3 or 4, and "b" is a number 0 or 1. M is preferably zirconium. Most preferably, the supported zirconocene/alumoxane catalyst is prepolymerized with ethylene or another olefin to provide spherical, free-flowing catalyst particles which give free-flowing particulate elastomer product from the slurry polymerization.

Title
Process for production of a high molecular weight ethylene a-olefin elastomer with a metallocene alumoxane catalyst
Application Number
7/207819
Publication Number
4871705
Application Date
June 16, 1988
Publication Date
October 3, 1989
Inventor
Elvin L Hoel
Westfield
NJ, US
Agent
M B Kurtzman
Assignee
Exxon Chemical Patents
NJ, US
IPC
C08F 4/64
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