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:
Nov. 01, 1988
Filed:
Aug. 27, 1985
Fumio Tsutsumi, Yokkaichi, JP;
Akio Iakashima, Kameyama, JP;
Mitsuhiko Sakakibara, Yokkaichi, JP;
Noboru Oshima, Suzuka, JP;
Tatsuo Fujimaki, Higshimurayama, JP;
Yoshiyuki Morimoto, Kodaira, JP;
Japan Synthetic Rubber Co., Ltd., Tokyo, JP;
Bridgestone Corporation, Tokyo, JP;
Abstract
A rubber composition containing at least 20% by weight of a styrene-butadiene block copolymer consisting of a block (A) and a block (B) characterized in that: (i) the block (A) is a styrene-butadiene copolymer block having the content of styrene of 10-80% by weight and the average content of the vinyl bonds in the butadiene portion of 30-70% by weight; (ii) the block (B) is a polybutadiene block with the average content of the vinyl bonds in the butadiene portion being not more than 60% by weight (iii) the styrene-butadiene block copolymer contains at least 20% by weight of each of the block (A) and the block (B); (iv) the average content of the vinyl bonds in the butadiene portion of the block (A) is greater by at least 5% by weight than that of the block (B); (v) the glass transition temperature of the block (A) is higher by at least 30.degree. C. than that of the block (B); (vi) the whole content of the bound styrene in the above block copolymer is 5-40% by weight; (vii) the ratio Mw/Mn between the weight average molecular weight Mw and the number average molecular weight Mn of the block copolymer is 1.8-5.0 when calculated as polystyrene according to the gel permeation chromatogram; and (viii) the Mooney's viscosity (ML.sub.1+4.sup.100.degree. C.) of the block copolymer is 20-150.