Sumitomo Rubber Industries Limited

Keiji Ikeda

Takashi Miki

Takayuki Nagase

Takao Wada

Kazuyuki Nishioka

Tatsuhiro Tanaka

Takahiro Kawachi

Tomoaki Hirayama

Kenya Watanabe

Noboru Wakabayashi

Tetsuya Maekawa

Sofue Naoya

A rubber composition comprises 5 to 30 parts by mass of a terpene resin having a softening point of 100 to 120&#xb0; C. and a molecular weight of 500 to 10,000, and 2 to 10 parts by mass of a liquid rubber or a liquid resin having a molecular weight of 100 to 3,500, based on 100 parts by mass of a rubber component comprising 72 to 95% by mass of an aromatic olefin rubber and 5 to 28% by mass of a diene olefin rubber, wherein a ratio of a content of the terpene resin to a content of the liquid rubber or the liquid resin (a content of the terpene resin/a content of the liquid rubber or the liquid resin) is from 0.5 to 5, and the tire is one having a tire member composed of the rubber composition.

Rubber composition and tire

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire characterized by initiating kneading of a rubber component and a compound of the formula (1) before kneading the rubber component and a silane coupling agent having a mercapto group. (Wherein Rrepresents a straight-chain or branched chain alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms, and Rand Rtogether with nitrogen bonded thereto form a succinimide group, a maleimide group or a phthalimide group.)

Preparation method of rubber composition for tire and production method of tire

Provided are a rubber composition for treads which achieves a balanced improvement in fuel economy, abrasion resistance, and wet grip performance while offering good processability, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for treads containing: a polybutadiene; and a terpene resin having a glass transition temperature (Tg) of 40&#xb0; C. to 90&#xb0; C., the polybutadiene satisfying the following conditions (A), (B) and (C): (A) a ratio (Tcp/ML, 100&#xb0; C.) of 5% by mass toluene solution viscosity (Tcp) to Mooney viscosity (ML, 100&#xb0; C.) is 0.9 to 2.3; (B) a stress relaxation time (T80) is 10.0 to 40.0 seconds, which is a time required for torque to decay by 80%, where 100% represents torque at the end of a ML, 100&#xb0; C. measurement; and (C) a molecular weight distribution (Mw/Mn) is 2.50 to 4.00.

Rubber composition for treads and pneumatic tire

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire is characterized by initiating kneading of a rubber component and a compound represented by the following formula (1) before kneading the rubber component and a silane coupling agent having a mercapto group. (Wherein each of Rto Rindependently represents a straight-chain or branched chain alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms.)

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire is characterized by initiating kneading of a rubber component and a specific polysulfide compound before kneading the rubber component and a silane coupling agent having a mercapto group.

A rubber composition for a tire includes a rubber component containing at least one of a natural rubber and an epoxidized natural rubber, silica and a natural based wax, wherein the silica is contained in an amount of 10 parts by mass or more based on 100 parts by mass of the rubber component and the natural based wax is contained in an amount of 1.2% by mass or more and 2% by mass or less based on the total mass of the rubber composition for a tire, and to a tread, a side wall, a clinch and a tire using the rubber composition. A rubber composition for a base tread used to form a base tread of a tire, the rubber composition includes a rubber component composed of a diene based rubber, silica contained in an amount 20 parts by mass or more and 70 parts by mass or less based on 100 parts by mass of the rubber component consisting of a diene based rubber and a natural based wax contained in an amount of 2 parts by mass or more and 15 parts by mass or less based on 100 parts by mass of said rubber component composed of the diene based rubber, and to a base tread and a tire obtained by using the rubber composition for a base tread.

Rubber composition for tire, tire member, base tread rubber composition, base tread and tire

There is provided a rubber composition whose run-flat durability is improved and in which precipitation of sulfur and a vulcanization accelerator on the rubber surface before vulcanization is prevented. Sulfur in an amount of 2 to 8 parts by weight and two or more vulcanization accelerators in a total amount of at least 5 parts by weight based on 100 parts by weight of a rubber component are used, at least one of the accelerators being a sulfen amide accelerator.

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Kobe, Japan

Keiji Ikeda