CONTROLLING RESIN PROPERTIES IN A GAS PHASE POLYMERIZATION PROCESS

摘要

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.

主权项

1. 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.