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:
Mar. 20, 2012
Filed:
Aug. 16, 2006
Masahiro Sasagawa, Tokyo, JP;
Katsunori Nitta, Tokyo, JP;
Masahiro Sasagawa, Tokyo, JP;
Katsunori Nitta, Tokyo, JP;
Asahi Kasei Chemicals Corporation, Tokyo, JP;
Abstract
The present invention provides a process for producing a block copolymer in high productivity, by anionic polymerization by use of a lithium initiator, and also to provide the block copolymer and a hydrogenated product thereof, the block copolymer having a conjugated diene block portion with a high vinyl bond content and a vinyl aromatic block portion with a narrow molecular weight distribution and exhibiting a narrow molecular weight distribution and high strength. A conjugated diene monomer and a vinyl aromatic monomer by use of a lithium initiator, are block copolymerized by making a tertiary amine compound and (2) sodium alkoxide coexist, wherein (2)/(1) (a molar ratio)=from 0.01 or more to less than 0.1.