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:
Apr. 17, 1990
Filed:
Mar. 08, 1989
Yuichi Saito, Kobe, JP;
Takuzoh Yabuta, Minoo, JP;
Hiroyoshi Takao, Chiba, JP;
Akio Imai, Ichihara, JP;
Mitsuji Tsuji, Ichihara, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Sumitomo Rubber Industries, Ltd., Kobe, JP;
Abstract
A rubber composition suitable for tire treads having well-balanced excellent steering stability in cornering, wet skid characteristic, ice skid characteristic and rolling characteristic, and an excellent processability, which comprises a rubber component containing a block copolymer consisting essentially of a block A and a block B, obtained by conducting polymerization of an aromatic vinyl compound and a conjugated diene compound in a hydrocarbon solvent in the presence of an organolithium initiator and modifying with a coupling agent, and satisfying the following conditions (A) to (E); (A) the block A having a content of an aromatic vinyl compound of 5 to 29% by weight and a content of 1,2-bonds in the conjugated diene component of 25 to 55% by weight, (B) the block B having a content of an aromatic vinyl compound of 35 to 60% by weight and a content of 1,2-bonds in the conjugated diene component of 20 to 70% by weight, (C) the content of the block A in the block copolymer being from 20 to 80% by weight, (D) the average content of the aromatic vinyl compound in the block copolymer being from 20 to 40% by weight and the average content of 1,2-bonds in the conjugated diene component of the block copolymer being from 20 to 60% by weight, and (E) at least 40% by weight of the polymer chains of the block copolymer being a branched polymer formed by modification with a trifunctional or tetrafunctional coupling agent.