Bimetallic indenoindolyl catalysts
AssigneeEquistar Chemicals, LP
InventorsSandor Nagy, Barbara M. Tsuie, William J. Sartain
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Abstract
Catalyst systems useful for olefin polymerization are disclosed. The catalysts include a bimetallic complex that incorporates two linked indenoindolyl groups, each of which is pi-bonded through its cyclopentadienyl ring to one of the metals Compared with conventional indenoindolyl complexes, the bimetallic complexes of the invention have enhanced ability to give polyolefins with desirably low melt indices. Certain bimetallic indenoindolyl complexes also provide a way to broaden polymer molecular weight distribution and thereby improve processability simply by regulating the amounts of comonomer and activator used in the polymerization.
Claims12
A catalyst system which comprises
- (a) an activator;
- and
- (b) a bimetallic complex which comprises
- (i) two Group 3-10 transition metals, which may be the same or different;
- (ii) two monoanionic indenoindolyl groups, each of which is pi-bonded through its cyclopentadienyl ring to one of the metals;
- (iii) a divalent linking group that joins the indenoindolyl groups through an indenyl carbon or an indolyl nitrogen of each indenoindolyl group;
- and
- (iv) two or more ancillary ligands bonded to each metal that satisfy the valence of the metals.
Dependencies are inferred from the claim text.