Process for making ethylene homopolymers
AssigneeEquistar Chemicals, LP
InventorsMichael W. Lynch, Mark K. Reinking
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Abstract
A process for making an ethylene homopolymer in the presence of an oxide-supported chromium catalyst is disclosed. A small amount of an α-olefin contacted with the catalyst before polymerizing ethylene or introduced into an ethylene homopolymerization unexpectedly boosts process productivity. When used at part per million levels, the α-olefin improves productivity while maintaining desirable polymer properties. The invention is particularly valuable for making HDPE resins useful for blow molding applications.
Claims13
A process comprising polymerizing ethylene in a reactor in the presence of an oxide-supported chromium catalyst, a diluent, and an a-olefin to produce an ethylene homopolymer;
- wherein the α-olefin is used in an amount effective to increase the productivity of the process compared with the productivity of the process when performed in the absence of the α-olefin.
A process comprising polymerizing ethylene in a slurry-loop reactor in the presence of a silica-supported chromium catalyst, a volatile aliphatic hydrocarbon diluent, and an a-olefin selected from the group consisting of propylene, 1-butene, and isobutylene, to produce an ethylene homopolymer;
- wherein the α-olefin is used in an amount within the range of 1 to 500 ppm based on the amount of diluent.
Dependencies are inferred from the claim text.