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US 5,391,629 AGranted
Block copolymers from ionic catalysts
AssigneeExxon Chemical Patents Inc.
InventorsHoward W. Turner, Gregory G. Hlatky, Henry W.-H. Yang, Avinash C. Gadkari, Gary F. Licciardi
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Abstract
A process for the production of block copolymers of ethylene and an .alpha.-olefin such as propylene by using an ionic catalyst system including a metallocene component and a component having a cation capable of donating a proton and a compatible non-coordinating anion. Novel block copolymers are produced.
Claims11
A process for producing block or tapered copolymers having an Mw/Mn of about 3 or less, an Mw between about 100,000 to about 1,000,000, and a blocking efficiency of about 50% or more comprising the steps of:
- (i) contacting under polymerization conditions in a polymerization reactor a first olefinic monomer(s) with an activated catalyst complex which is the reaction product of:
- (a) a cyclopentadienyl Group IVB metal component, and
- (b) a second component of an alumoxane or a compatible non-coordinating anion to produce a first living polymer;
- and
- (ii) sequentially adding to said living polymer at least a second olefinic monomer(s) to copolymerize with said first polymer to produce a block or tapered copolymer.
2 more elements
Dependencies are inferred from the claim text.