Sumitomo Rubber Industries Limited

Shin-Etsu Chemical Co., Ltd.

Tsuyoshi Tsuchida

Tatsuya Miyazaki

Ryoji Kojima

Soh Ishino

Yukari Tomisaki

Reika Otake

Munenao Hirokami

Mutsuki Sugimoto

Hiroyuki Kishimoto

Kenichi Uesaka

Tetsuya Kunisawa

Ryuichi Tokimune

Tetsuro Yamada

Ryota Kitago

Takafumi Taguchi

Tatsuhiro Tanaka

Isamu Tsumori

Kenya Watanabe

Tomomi Masui

Toru Iizuka

Naoya Omura

Noboru Okabe

Ayaka Kitaou

A pneumatic tire comprising a tread composed of a rubber composition containing 30 to 120 parts by mass of silica having a BET specific surface area of 180 to 280 m/g based on 100 parts by mass of a rubber component, wherein, under a normal state with no load where the pneumatic tire is mounted with a normal rim and filled with a normal internal pressure, a grounding surface shape in which a normal load is applied and the tread is pressed against a plane surface satisfies the following equation (1): 0.95&#x2264;SL0/SL80&#x2264;1.6 (wherein, SL0 is a ground contact length in a circumferential direction of the tire on a tire equator, and SL80 is a ground contact length in a circumferential direction of the tire on a position away from the tire equator by a distance in a tire axial direction of 80% of a tread grounding half width.)

Pneumatic tire

The present invention provides a rubber composition for tires which provides significantly improved abrasion resistance while maintaining fuel economy, and a pneumatic tire including the rubber composition. The present invention relates to a rubber composition for tires including: a silane coupling agent containing an alkoxysilyl group and a sulfur atom, the alkoxysilyl group being linked to the sulfur atom by six or more carbon atoms; and sulfur, the rubber composition including, per 100 parts by mass of the rubber component therein, 1.5 parts by mass or less of the sulfur.

Rubber composition for tires, and pneumatic tires

Provided are a polymer ready for introduction into a kneading machine which is milled with good milling efficiency in a kneading machine and which provides a kneaded mixture with excellent filler dispersion, and a rubber composition and a pneumatic tire containing the polymer. The present invention relates to a polymer ready for introduction into a kneading machine, excluding natural rubber, the polymer having a temperature within the range of &#x2212;20&#xb0; C. to 80&#xb0; C. and satisfying the following formula (I):(Tip clearanceof kneading machine)&#x2264;(Volumeof polymer ready for introduction into kneading machine)&#x2264;2.0&#xd7;10cm&#x2003;&#x2003;(I).

Method for kneading a polymer

Provided are a rubber composition for tires which achieves both abrasion resistance and processability while maintaining fuel economy, and a pneumatic tire including the rubber composition. A rubber composition for tires, containing an organosilicon compound represented by the average compositional formula (I) below having a ratio of the number of sulfur atoms to the number of silicon atoms of 1.0 to 1.5, wherein x represents the average number of sulfur atoms; m represents an integer of 6 to 12; and Rto Rare the same or different and each represent a C1-C6 alkyl or alkoxy group, at least one of Rto Rand at least one of Rto Rare the alkoxy groups, and two or more of the alkyl or alkoxy groups for Rto Rmay be joined to form a ring.

Rubber composition for tires and pneumatic tire

Provided is a pneumatic tire including a tread formed from a predetermined rubber composition to achieve greatly improved abrasion resistance while maintaining good wet-grip performance and good durability. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing predetermined amounts of a specific oil-extended polybutadiene rubber, of an isoprene-based diene rubber and/or a styrene-butadiene rubber, of a specific carbon black, and of stearic acid, the oil-extended polybutadiene rubber being synthesized using a rare earth catalyst, the rubber composition having an amount of process oil of a predetermined value or less.

Provided is a pneumatic tire including a tread formed from a specified rubber composition, thereby achieving a balanced improvement in fuel economy, wet-grip performance, and abrasion resistance while simultaneously having excellent durability. The present invention relates to a pneumatic tire including a tread formed from a rubber composition, the rubber composition containing: an oil-extended BR having a cis content of 95 mol % or more, a vinyl content of 1 mol % or less, and a weight average molecular weight of 530,000 or more; a SBR having a bound styrene content of 30-50% by mass and a weight average molecular weight of 700,000 or more; silica; and carbon black, the oil-extended BR being synthesized using a rare earth catalyst, the rubber composition containing, based on 100% by mass of rubber solids, 10-67% by mass of the BR component contained in the oil-extended BR and 10-50% by mass of the SBR.

The inner liner is composed of a polymer layer stack including a first layer containing an SIBS and a second layer containing at least one of an SIS and an SIB. At least one of the first layer and the second layer is a polymer composition containing one of a C4 polymer obtained by polymerizing a monomer unit having 4 carbon atoms, a layered clay mineral with an organic compound intercalated therein and at least one kind of rubber component selected from the group consisting of a natural rubber, an isoprene rubber and a butyl rubber. The second layer is arranged to come into contact with a rubber layer of the carcass ply. The inner liner has a thickness Ge at a shoulder position Pe exceeding 100% and being less than or equal to 500% of a thickness Gc at a crown central position Pc.

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. 

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Kobe, Japan

Tsuyoshi Tsuchida