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US 6,664,349 B2Granted
Ethylene polymerization process
AssigneeEquistar Chemicals, LP
InventorsShaotian Wang, Jean A. Merrick-Mack
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Abstract
An ethylene polymerization process is disclosed. The process uses a single-site catalyst that contains a boraaryl ligand. It comprises supporting the catalyst, forming a slurry of the supported catalyst in an organic solvent, mixing the catalyst slurry with trialkyl aluminum compound, and polymerizing ethylene in the presence of the trialkyl aluminum-treated catalyst slurry. The process gives polyethylene having a controlled long-chain-branch index.
Claims16
A process which comprises:
- (a) combining a Group 4 metal catalyst that contains at least one boraaryl ligand with a support selected from the group consisting of inorganic oxides, inorganic chlorides, and organic polymer resins;
- (b) forming a slurry of the supported catalyst in an organic solvent;
- (c) mixing the catalyst slurry with a trialkyl aluminum compound prior to adding the catalyst slurry to a polymerization reactor;
- and
- (d) polymerizing an olefin that comprises:
- i) from 50 to 100 mole % of ethylene;
- and
- ii) from 0 to 50 mole % of a C3-C10 α-olefin in the presence of the product of step (c) and an activator, and in the absence of hydrogen, wherein the polymer has a long-chain-branch index (LCBI) greater than about 0.67.
5 more elements
Dependencies are inferred from the claim text.