Catalyst composition comprising shuttling agent for regio-irregular multi-block copolymer formation
View Patent ↗Copolymers, especially multi-block copolymer containing therein two or more segments or blocks, are prepared by polymerizing propylene, 4-methyl-1-pentene, or another C 4-8 α-olefin in the presence of a composition comprising the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers having increased incidence of regio-irregular branching compared to the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.
1. A copolymer formed by polymerizing propylene, 4-methyl-1-pentene, or another C 4-8 α-olefin in the presence of a composition comprising the admixture or reaction product resulting from combining:
(A) a first olefin polymerization catalyst,
(B) a second olefin polymerization catalyst capable of preparing a polymer having increased incidence of regio-irregular branching compared to the polymer prepared by catalyst (A) under equivalent polymerization conditions, and
(C) a chain shuttling agent
wherein the copolymer has a Tm≧120° C. and a Tg≦−30° C.
2. A copolymer formed by polymerizing propylene, 4-methyl-1-pentene, or another C 4-8 α-olefin, and a copolymerizable comonomer in the presence of a composition comprising the admixture or reaction product resulting from combining:
(A) a first olefin polymerization catalyst that under the conditions of polymerization forms a tactic polymer of one or more C 3-20 α-olefins,
(B) a second olefin polymerization catalyst capable of preparing a polymer having increased incidence of regio-irregular branching compared to the polymer prepared by catalyst (A) under equivalent polymerization conditions, and
(C) a chain shuttling agent
wherein the copolymer has a Tm≧120° C. and a Tg≦−30° C.
3. A multi-block copolymer consisting essentially of propylene in polymerized form, said copolymer containing therein two or more segments or blocks differing in regio-irregular 2,1- and/or 3,1-monomer insertion wherein the copolymer has a Tm≧120° C. and a Tg≦−30° C.
4. A multi-block copolymer consisting essentially of 4-methyl-1-pentene in polymerized form, said copolymer containing therein two or more segments or blocks differing in regio-irregular 2,1- and/or 3,1-monomer insertion wherein the copolymer has a Tm≧120° C. and a Tg≦−30° C.
5. A copolymer according to claim 1 or 2 wherein the shuttling agent is a trihydrocarbyl aluminum- or dihydrocarbyl zinc- compound containing from 1 to 12 carbons in each hydrocarbyl group.
6. A copolymer according to claim 5 wherein the shuttling agent is triethylaluminum or diethylzinc.