Olefin polymerization
AssigneePhillips Petroleum Company
InventorsPeter Schertl, Helmut G. Alt, M. Bruce Welch
Life of this patent
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Abstract
A catalyst system and process for polymerizing olefins employing a cocatalyst and specific ethylene bridged fluorenyl-containing metallocenes having substituents which result in high yields of polyethylene and/or high molecular weight polyethylene.
Claims18
A process for polymerizing at least one olefin comprising contacting said at least one olefin with a catalyst system produced by combining a metallocene and a suitable cocatalyst, said metallocene being selected from bridged metallocenes of Group IVB metals having two fluorenyl components bonded at the 9-position to opposite ends of an ethylene bridge further characterized by the fact that at least one of the fluorenyl group is substituted by a substituent selected from the group consisting of (1) a substituent in the 4-position selected from the group consisting of alkyl, aryl, and aralkyl radicals having 1 to 10 carbon atoms;
- (2) aryl substituents at the 2- and 7-positions;
- (3) tertiary butyl substituents at the 2- and 7-positions;
- and (4) a 4,5-benzo substituent.
A catalyst system suitable for the polymerization of olefins, produced by combining a metallocene and a suitable cocatalyst, said metallocene being selected from bridged metallocenes of Group IVB metals having two fluorenyl components bonded at the 9-position to opposite ends of an ethylene bridge further characterized by the fact that at least one of the fluorenyl group is substituted by a substituent selected from the group consisting of (1) a substituent in the 4-position selected from the group consisting of alkyl, aryl, and aralkyl radicals having 1 to 10 carbon atoms;
- (2) aryl substituents at the 2- and 7-positions;
- (3) tertiary butyl substituents at the 2- and 7-positions;
- and (4) a 4,5-benzo substituent.
Dependencies are inferred from the claim text.