Patent ID: 6800707
Filing Date: 2004-10-05
Classification: C08F,Y10S

Abstract:
A process for preparing a syndiotactic polyolefin having a monomer length of up C10 which comprises:(a) contacting: 1) a metallocene catalyst component having the general formula: Râ€³(CpR1R2)(Cpâ€²R1â€²R2â€²)MQ2 â€ƒwherein Cp is a cyclopentadienyl ring; Cpâ€² is a 3,6 di substituted fluorenyl ring; R1 and R2 are each independently H or a substituent on the cyclopentadienyl ring which is proximal to the bridge, provided that at least one of R1 and R2 is a proximal substituent, which proximal substituent is linear hydrocarbyl group of from 1 to 20 carbon atoms or a group of the formula XR*3 containing up to 7 carbon atoms in which X is chosen from Group IVA, and each R* is the same or different and chosen from hydrogen or an alkyl group; R1 and R2 are each independently substituent groups on the fluorenyl ring, each 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 group having 1 to 20 carbon atoms; M is a Group IVB transition metal or vanadium; each Q is a hydrocarbyl group having 1 to 20 carbon atoms or is a halogen; Râ€³ is a structural bridge imparting stereorigidity to the component and comprises the moiety TRaRb, in which T is chosen from group IVA, and each of Ra and Rb is independently (i) a substituted or unsubstituted aryl linked to T directly or by a C1-C4 alkylene; or (ii) H; and 2) an aluminum or boron containing co-catalyst component capable of activating the metallocene catalyst component; and (b) contacting the activated catalyst of subparagraph (a) with at least one olefin in a reaction zone under polymerization conditions to form a syndiotactic polyolefin having a monomer length of up to ten carbon atoms.