Patent ID: 6875719

Claim:
A catalyst composition for preparing an olefin polymer, comprising: (a) a metallocene compound represented by the formula (I) wherein R 1 is the same or different and is hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or an arylalkyl group having from 1 to 20 carbon atoms, or two adjacent R 1 groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms when no two adjacent R 2 groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms. and each remaining R 1 group is the same or different and is hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or an arylalkyl group having from 1 to 20 carbon atoms; R 2 is the same or different and is hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or an arylalkyl group having from 1 to 20 carbon atoms, or two adjacent R 2 groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms when no two adjacent R 1 groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms, and each remaining R 2 group is the same or different and is hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or an arylalkyl group having from 1 to 20 carbon atoms; X is carbon; n is 2, 3 or 4; R 3 and R 4 are the same or different and are hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or arylalkyl group having from 1 to 12 carbon atoms; M is a Group 4 transition metal with an oxidation state of +4; Q is the same or different and is independently an anionic ligand with a −1 valence; and (b) an activating cocatalyst of (1) an aluminoxane, or (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.