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.
Claims20
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;
- 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-C1α-olefin
- in the presence of the product of step (c) and an activator.
The process of claim I wherein the boraaryl ligand is selected from the group consisting of borabenzenes, boranaphthalenes, boraanthracenes, and boraphenathrenes.
A process which comprises:
- (a) combining
- (i) a Group 4 metal catalyst that contains at least one boraaryl ligand;
- (ii) an activator selected from the group consisting of anionic compounds of boron or aluminum, trialkylboron compounds, and triarylboron compounds;
- and
- (iii) a support selected from the group consisting of inorganic oxides, inorganic chlorides, and organic polymer resins;
- (b) forming catalyst slurry of the supported catalyst in an organic solvent;
- (c) mixing the catalyst slurry with a trialkyl aluminum compound;
- 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).
A process which comprises:
- (a) combining
- (i) a Group 4 metal catalyst that contains at least one boraaryl ligand;
- (ii) an activator selected from the group consisting of anionic compounds of boron or aluminum, trialkylboron compounds, and triarylboron compounds;
- and
- (iii) a support selected from the group consisting of inorganic oxides, inorganic chlorides, and organic polymer resins;
- (b) forming catalyst slurry of the supported catalyst in an organic solvent;
- (c) mixing the catalyst slurry with a trialkyl aluminum compound;
- 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), in the absence of hydrogen and at a temperature less than 90° C.;
- wherein the polyethylene produced has an LCBI greater than about 0.67.
Dependencies are inferred from the claim text.