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:
Oct. 30, 2001
Filed:
Oct. 23, 1999
Nobuhiro Kobayashi, Takatsuki, JP;
Masatoshi Yoshida, Nara, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
The present invention provides a new star-shaped block copolymer and a production process therefor, wherein the new star-shaped block copolymer has high heat resistance despite having a low viscosity. It has been found that a new star-shaped block copolymer has high heat resistance wherein the new star-shaped block copolymer comprises a plurality of star-shaped structures,in which at least three chain polymer segments,are radially extended from a central polyvalent mercaptan segment,, wherein the star-shaped structures,are bonded to each other through a bonding structure,at their chain polymer segments. In addition, in a production process for a star-shaped block copolymer comprising the multistep radical polymerization in the presence of a polyvalent mercaptan wherein the elementary steps of the multistep radical polymerization differ in polymerizable monomers as used therein, the improvement according to the present invention is characterized in that at least one of the elementary steps of the multistep radical polymerization involves the joint use of a polyfunctional monomer with the polymerizable monomer.