Controlling resin properties in a gas phase polymerization process
AssigneeNOVA Chemicals (International) S.A.
InventorsVictoria Ker, Yan Jiang, Sergio Alejandro Guillen-Castellanos
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Abstract
Methods for dramatically altering the processability of ethylene copolymers made with a supported phosphinimine polymerization catalyst. The method involves changing the polymerization reactor temperature during the polymerization of ethylene and a least one alpha-olefin when a phosphinimine catalyst which comprises a substituted or unsubstituted indenyl ligand and a phosphinimine type ligand.
Claims10
A method for altering the stress exponent of an ethylene copolymer, the method comprising polymerizing ethylene and an alpha-olefin in a gas phase reactor with a polymerization catalyst, the polymerization catalyst comprising a phosphinimine catalyst, an inert support, and a cocatalyst;
- wherein the stress exponent of the ethylene copolymer is altered by changing the temperature in the reactor by at least 1° C.;
- and wherein the phosphinimine catalyst has the formula:
- LTi(N═P(t-Bu)3)X2;
- where L is a substituted or unsubstituted indenyl ligand and X is an activatable ligand.
Dependencies are inferred from the claim text.