REVERSIBLE CHAIN-TRANSFER IN POLYOLEFIN POLYMERIZATION WITH PYRIDYLDIAMIDE CATALYSTS

摘要

A process of producing ethylene α-olefin copolymers, especially ethylene block copolymers, comprising contacting ethylene and a C3 to C10 α-olefin with a transition metal pyridyldiamide (MPN3) catalyst component and an activator, as well as from 10 equivalents to 1000 equivalents relative to the catalyst component of chain transfer agent; isolating an ethylene-α-olefin copolymer having a Tm of less than 140° C., a MWD of less than 2.5, and a weight average molecular weight (Mw) within the range of from 5 kDa to 500 kDa. The chain transfer agent can be selected from Group 2, 12 or Group 13 alkyl or aryl compounds.