Sumitomo Rubber Industries Limited

Toru Iizuka

Shinichi Miyazaki

Mutsuki Sugimoto

Naohiko Kikuchi

Tetsuya Kunisawa

Kiyoshige Muraoka

Kenichi Uesaka

Takao Wada

Toshiro Matsuo

Takafumi Taguchi

Tatsuhiro Tanaka

Isamu Tsumori

Kenya Watanabe

Tsuyoshi Tsuchida

Noboru Wakabayashi

Tomomi Masui

Keiichi Nakadera

Yoko Nakada

Takahiro Fukumoto

Naoya Omura

Reika Otake

Noboru Okabe

Kaoru Koyama

The present invention is a pneumatic tire comprising an inner liner disposed on the inner side of the tire. The inner liner is composed of a sheet made of an elastomer composition containing a styrene-isobutylene-styrene triblock copolymer by more than or equal to 7 percent by mass and less than or equal to 93 percent by mass and an isobutylene-based modified copolymer containing a &#x3b2;-pinene component by more than or equal to 7 percent by mass and less than or equal to 93 percent by mass. In the inner liner, a ratio Gs/Gb between an average thickness Gb in a bead region Rb extending from a tire largest width position to a bead toe and an average thickness Gs in a buttress region Rs extending from the tire largest width position to a corresponding position Lu at a belt layer end is 0.30 to 0.75.

Pneumatic tire

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, and abrasion resistance in a balanced manner, and a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a silane coupling agent, wherein the rubber component contains, based on 100% by mass of the rubber component, not less than 5% by mass of a conjugated diene polymer containing a constituent unit based on a conjugated diene and a constituent unit represented by formula (I) below, at least one terminal of the polymer being modified with a specific compound; an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component; and the silane coupling agent contains a mercapto group. 

Rubber composition and pneumatic tire

A pneumatic tire capable of reducing rolling resistance and discharging static electricity generated during running, wherein each of a tread rubber, a breaker rubber, and a sidewall rubber formed on the tread part, the breaker part, and the sidewall part, respectively, has a volume specific resistivity of 1&#xd7;10&#x3a9;&#xb7;cm or more, the pneumatic tire further including a conduction rubber embedded in the tread part so as to be at least partially exposed to a surface of the tread part, bead part rubber disposed at a region contacting a rim flange of the bead part, and electroconductive rubber electrically connecting the conduction rubber to the beat part rubber, wherein each of the conduction rubber, the bead part rubber, and the electroconductive rubber has a volume specific resistivity of less than 10&#x3a9;&#xb7;cm.

The present invention provides a racing tire tread rubber composition which is used for producing a racing tire having excellent wet grippability and does not cause any excessive adhesion in tire production process steps such as kneading and extruding steps. The racing tire tread rubber composition is a composition comprising: 100 parts by weight of a diene-based rubber; a filler, the entirety of which is in the range of 100 to 250 parts by weight containing 20 parts by weight or more of silica; and 5 to 50 parts by weight of a factice.

Racing tire tread rubber composition

A rubber composition suitable for reinforcing beads of tires, having high hardness, high durability and high aging resistance, which comprises a rubber component containing 30 to 70% by weight of a butadiene rubber containing syndiotactic crystals, 60 to 75 parts by weight of a carbon black having a specified iodine adsorption number and a specified oil absorption, 1 to 2 parts by weight of sulfur and 2 to 4 parts by weight of a sulfenamide accelerator, respectively, per 100 parts by weight of the rubber component, wherein the total amount of sulfur and the sulfenamide accelerator is from 3 to 5 parts by weight.

Rubber composition for reinforcing bead of tires which contains

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Kobe, Japan

Toru Iizuka