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. 22, 1983
Filed:
Oct. 29, 1981
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
In producing a block copolymer resin having vinyl aromatic hydrocarbon polymer blocks such as of styrene and polymer blocks primarily composed of conjugated diene such as of butadiene successively through living polymers using an organolithium compound as a catalyst in an aliphatic solvent, the vinyl aromatic hydrocarbon monomer for forming the vinyl aromatic hydrocarbon polymer block is added at a controlled rate, at the stage when the vinyl aromatic hydrocarbon content in the polymer formed has reached a certain value, higher than the polymerization rate of the vinyl aromatic hydrocarbon monomer at the polymerization temperature but at a rate which can maintain the solubility parameter of the liquid phase portion in the polymerization system at 7.7 or less, whereby a block copolymer resin with good transparency and impact strength can be produced with good productivity.