Patent ID: 6930157

Claim:
A process for preparing an olefin polymer, comprising the step of: polymerizing (a) an olefin, or (b) at least one olefin with at least one other monomer, under polymerizing conditions in the presence of a catalytically effective amount of a catalyst composition comprising: (i) a metallocene compound represented by the following formula wherein R is a C 1 -C 20 hydrocarbyl group; and (ii) an activating cocatalyst selected from the group consisting of (1) an aluminoxane, (2) a mixture of AlR 11 R 12 R 13 and a borate, or (3) a mixture of AlR 11 R 12 R 13 and an aluminoxane, wherein R 11 , R 12 , and R 13 are a C 1-20 aliphatic group or a C 6-10 aromatic group.