Olefin polymerization catalysts containing modified boraaryl ligands
AssigneeEquistar Chemicals, LP
InventorsShaotian Wang, Jean A. Merrick-Mack
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Abstract
A single-site olefin polymerization catalyst is described. The catalyst comprises an activator and an organometallic compound that includes a Group 3 to 10 transition or lanthanide metal, M, and a modified boraaryl ligand. We surprisingly found that the catalyst is more active in olefin polymerization compared to other catalysts containing non-modified boraaryl ligands. Most surprisingly, the supported catalyst gives polyolefins with a multimodal molecular weight distribution having separate components of distinct molecular weight.
Claims20
A catalyst which comprises:
- (a) an activator;
- and
- (b) an organometallic compound comprising a Group 3 to 10 transition or lanthanide metal, M, and a modified boraaryl ligand that is π-bonded to M, wherein the modified boraaryl ligand is a boraaryl ligand that is covalently linked through carbon to a silicon, germanium, tin, or lead atom.
A catalyst which comprises:
- (a) an activator;
- and
- (b) an organometallic compound of the formula:
- where
- M is a Group 4-6 transition metal;
- L is hydride, halide, C1-C20 alkoxy, siloxy, hydrocarbyl, dialkylamido, or mixtures thereof;
- R is C1-C20 hydrocarbyl;
- X is hydrogen, C1-C20 hydrocarbyl, C1-C20 aralkyl, or C1-C20 dialkylamino;
- and
- a=1-4.
A method for producing polyolefins comprising reacting an olefin in the presence of a catalyst which comprises a support, an alumoxane activator, and an organometallic compound comprising a Group 3 to 10 transition or lanthanide metal, M, and a modified boraaryl ligand that is covalently linked through carbon to a silicon, germanium, tin, or lead atom, wherein the polyolefin produced has a multimodal molecular weight distribution with separate components of distinct molecular weight.
Dependencies are inferred from the claim text.