The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 1989
Filed:
Feb. 18, 1986
Sumitomo Chemical Company, Osaka, JP;
Abstract
A process for producing a thermoplastic elastomer comprising a block copolymer of the A-B-A' type, wherein A is a monovinyl aromatic hydrocarbon polymer block, B is a conjugated diolefin polymer block, and A' is either the same as A or a polymer block derived from a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon, which process comprises polymerizing a monovinyl aromatic hydrocarbon in a polymerization medium in the presence of an organomonolithium compound as a polymerization initiator, adding a conjugated diolefin to perform block copolymerization, and further adding a monovinyl aromatic hydrocarbon to perform polymerization or in the alternative, adding a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon to perform coupling, wherein the monomer components are used in such amounts that the weight ratio of (A+A') to B ranges from 10/90 to 65/35, and a chained aliphatic hydrocarbon solvent containing from 0.0001 to 0.1 wt % of a Lewis basic compound is used as the polymerization medium, is disclosed. According to the process of the invention, the desired thermoplastic elastomer having good physical properties is readily obtainable with high reproducibility.