Bridgestone Corporation

Jsr Corporation

Kouji Masaki

Noriko Mori

Yoichi Ozawa

Ken Tanaka

Terrence Eugene Hogan

Christine M Rademacher

Takuo Sone

Junko Matsushita

Eiju Suzuki

Ryuji Nakagawa

Kazuhiro Yanagisawa

Eiji Suzuki

Takaomi Matsumoto

Yuki Itoh

Junko Kurazumi

Shigeaki Matsuo

Fumihiro Shiraishi

Fuminori Oota

The invention provides a method for producing a modified conjugated diene (co)polymer, the method including comprising: a modification reaction step including causing an organic silane compound to react with a conjugated diene (co)polymer having an active site at the active site, the organic silane compound having a characteristic group for forming a silanol group through hydrolysis and, in the vicinity of the characteristic group, (i) a functional group which binds the organic silane compound to the conjugated diene (co)polymer via addition to or substitution at the active site and which promotes reaction between the silanol group and a reinforcing filler after the addition or substitution reaction, or (ii) a functional group which promotes reaction between the silanol group and a reinforcing filler, and a hydrolyzation step performed after the modification reaction step; a modified conjugated diene (co)polymer having, at a molecular end of the conjugated diene (co)polymer, a silanol group, and a functional group in the vicinity of the silanol group, the functional group accelerating reaction between the silanol group and the reinforcing filler; a rubber composition containing the (co)polymer and carbon black having specific characteristics; and a tire formed from the rubber composition.

Method for producing modified conjugated diene polymer/copolymer, modified conjugated diene polymer/copolymer, and rubber composition and tire using the same

A process for producing a modified conjugated diene based polymer includes a step (a) of reacting a silicon compound with a conjugated diene based polymer having an active end so that the reaction takes place at the active end, the silicon compound having a protected primary amino group in the molecule thereof and a silicon atom to which a hydrocarbyloxy group and a reactive group are bonded, to thereby modify the active end, and a step (b) of performing condensation reaction, in the presence of a titanium compound serving as a titanium-based condensation-accelerating agent. A rubber composition contains the modified diene polymer, and a tire is produced from the rubber composition.

Process for production of modified conjugated diene polymers, modified conjugated diene polymers produced by the process, rubber compositions, and tires

A rubber composition for tire sidewall which comprises a rubber component, which comprises polybutadiene rubber having a content of the cis-1,4-bond of 92% or greater and a content of the vinyl bond of 1.5% or smaller and natural rubber and/or at least one other diene-based synthetic rubber, and 10 to 70 parts by mass of carbon black having a specific surface area by nitrogen adsorption of 20 to 100 m/g per 100 parts by mass of the rubber component and does not comprise a softener having an aniline point of 50&#xb0; C. or lower and a tire using the rubber composition for sidewall. Excellent resistance to cut growth is obtained while sufficient workability is surely exhibited.

Rubber composition for tire sidewall and tire

This invention relates to a rubber composition having a high storage modulus (G') and a low loss tangent (tan &#x3b4;), and more particularly to a rubber composition comprising 2 to 60 parts by mass of a low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer (B) having an aromatic vinyl compound content of 5 to 80% by mass, a vinyl bond content in a conjugated diene compound portion of 5 to 80% by mass, a weight average molecular weight as measured through a gel permeation chromatography and converted to polystyrene of 5,000 to 500,000 and at least one functional group based on 100 parts by mass of a rubber component (A) composed of at least one of natural rubber and synthetic diene-based rubbers.

Rubber composition and pneumatic tire using the same

This invention relates to a rubber composition having excellent workability, fracture characteristics and wear resistance and a low heat buildup and a high storage modulus (G'), and more particularly to a rubber composition comprising not less than 20 parts by mass of a reinforcing filler (B) and 5 to 60 parts by mass of a low-molecular weight aromatic vinyl compound-conjugated diene compound copolymer (C) having an aromatic vinyl compound content of 5 to 80% by mass, a vinyl bond content in a conjugated diene compound portion of 10 to 80% by mass and a weight average molecular weight as measured with a gel permeation chromatography and converted to polystyrene of 5,000 to 300,000 based on 100 parts by mass of a rubber component (A) containing not less than 10% by mass of a modified conjugated diene-based polymer having at least one functional group.

Rubber composition and tire using same

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Tokyo, Japan

Kouji Masaki