Sumitomo Rubber Industries Limited

Yoshihiro Kagawa

Naoya Ichikawa

Kenichi Uesaka

Takafumi Taguchi

Yoji Imoto

Satomi Yamauchi

The present invention provides a rubber composition for an undertread, which has improved in processability, fuel economy, and tensile properties in a balanced manner, and also provides a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for an undertread, including: a rubber component containing a modified natural rubber having a phosphorus content of 200 ppm or less; and carbon black and/or a white filler, wherein the modified natural rubber is contained in an amount of 5% by mass or more per 100% by mass of the rubber component.

Rubber composition for undertread, 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, 

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Kobe, Japan

Yoshihiro Kagawa