Sumitomo Rubber Industries Limited

Yoji Imoto

Kenichi Uesaka

Takafumi Taguchi

Satomi Yamauchi

Mutsuki Sugimoto

Ryuichi Tokimune

Tetsuya Kunisawa

Masako Nakatani

Masato Kawase

Naoya Omura

Yoshihiro Kagawa

Akinori Nagae

In a method for manufacturing a pneumatic tire, molding of a green tire has an assembly step of bonding an inner liner and an unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction to manufacture a laminate, cutting the laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet, and a joining step of winding the cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining the end portions of the inner liner and joining the end portions of the unvulcanized rubber sheet such that positions of the joined end portions are displaced by a constant distance.

Method for manufacturing pneumatic tire

Provided are a tread rubber composition that can achieve a balanced improvement in fuel economy, wet-grip performance, and abrasion resistance, and a pneumatic tire including the composition. The tread rubber composition includes: a rubber component; silica; and a silane-coupling agent containing a mercapto group, the rubber component including per 100% by mass thereof 5% by mass or more of a conjugated diene polymer (A), the polymer (A) including a monomer unit derived from a conjugated diene, a monomer unit derived from a compound of formula (1), and a monomer unit derived from a compound of formula (2), at least one end of the copolymer (A) being modified by the following compound (G) or an alkoxysilane compound, the composition including 5-150 parts by mass of the silica per 100 parts by mass of the rubber component, Compound (G): at least one compound selected from the group consisting of compounds containing an optionally-substituted amino group and a carbonyl group and compounds containing an optionally-substituted amino group and a thiocarbonyl group,V-S&#x2003;&#x2003;(1)V-A&#x2003;&#x2003;(2)wherein Vand Veach represent a hydrocarbyl group containing a polymerizable carbon-carbon double bond; Srepresents a substituted silyl group, and Arepresents a substituted amino group or a nitrogen-containing heterocyclic group.

Tread rubber composition and pneumatic tire

The present invention provides a rubber composition that can enhance the fuel economy, wet-grip performance, abrasion resistance, and processability in a balanced manner, and also provides a pneumatic tire using this rubber composition. The present invention relates to a rubber composition that contains a rubber component, silica, and a compound represented by formula (1) below, 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; and an amount of the silica is 5 to 150 parts by mass per 100 parts by mass of the rubber component. 

Rubber composition and pneumatic tire

The invention provides a rubber composition that can enhance fuel economy, wet-grip performance, abrasion resistance, and handling stability in a balanced manner, and a pneumatic tire using this composition. The invention relates to a rubber composition containing a rubber component, silica (1) having a nitrogen adsorption specific surface area of not more than 100 m/g, and silica (2) having a nitrogen adsorption specific surface area of at least 180 m/g, wherein the rubber component contains, based on 100% by mass of the rubber component, at least 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; and a total amount of silica (1) and silica (2) is 30-150 parts by mass per 100 parts by mass of the rubber component, 

A rubber composition for a sidewall reinforcing layer and a run-flat tire reduces heat build-up, enhances elongation at break at high temperature, and increases run-flat durability, while maintaining good rigidity. The composition contains a rubber component including tin-modified BR (a) and/or BR (b) modified by a compound of formula (1) wherein R, R, and Rmay be the same as or different from one another and each represent an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group, a mercapto group, or a derivative thereof; Rand Rmay be the same as or different from each other and each represent a hydrogen atom or an alkyl group; and n denotes an integer; and an alkylphenol-sulfur chloride condensate, wherein an amount of the alkylphenol-sulfur chloride condensate is 3-10 parts by mass per 100 parts by mass of the rubber component.

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Kobe, Japan

Yoji Imoto