Patent ID: 6515086
Filing Date: 2003-02-04
Classification: C08F,Y10S

Abstract:
A process for preparing polyolefins having a monomer length of up to C10, which comprisesa) contacting: (1) a metallocene catalyst component for the preparation of a polyolefin which comprises an isotactic polyolefin or syndiotactic/isotactic block polyolefin having a monomer length of up to C10, the component having the general formula: Râ€³(CpR1R2R3)(Cpâ€²R1â€²R2â€²)MQ2 wherein Cp is a cyclopentadienyl ring substituted with at least one substituent of R1, R2 and/or R3; Cpâ€² is a substituted fluorenyl ring with substituents R1â€² and R2â€²; Râ€³ is a structural bridge imparting stereorigidity to the component; R1 is a substituent on the cyclopentadienyl ring which is distal to the bridge, which distal substituent comprises a bulky group of the formula XR*3 in which X is chosen from Group IVA, and each R* is the same or different and chosen from hydrogen or hydrocarbyl of from 1 to 20 carbon atoms, R2 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vicinal to the distal substituent and is of the formula YR#3 in which Y is chosen from group IVA, and each R# is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms; R3 is a substituent on the cyclopentadienyl ring which is proximal to the bridge and is a hydrogen atom or is of the formula ZR$3, in which Z is chosen from group IVA, and each R$ is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms; R1â€² and R2â€² are each independently substituent groups at positions 3 and 6 on the fluorenyl ring, respectively, one of which is a group of the formula ARâ€²â€³3, in which A is chosen from Group IVA, and each Râ€²â€³ is independently hydrogen or a hydrocarbyl having 1 to 20 carbon atoms and the other is hydrogen or a second group of the formula ARâ€²â€³3; M is a Group IVB transition metal or vanadium; and each Q is hydrocarbyl having 1 to 20 carbon atoms or is a halogen, and(2) an aluminum- or boron-containing co-catalyst capable of activating the catalyst component; and b) contacting the activated catalyst with at least one olefin in a reaction zone under polymerization conditions to form an isotactic polyolefin or a syndiotactic/isotactic block polyolefin.