Sumitomo Rubber Industries Limited

Rie Yasuda

Kensuke Washizu

Ryota Kitago

Shogo Hirao

Ryoji Matsui

The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in tan δ peak temperature over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 0.45 or less.

Rubber composition and pneumatic tire

Provided are a rubber composition which provides a self-healing rubber with improved strength and wet grip performance, and a pneumatic tire including the rubber composition. The present disclosure relates to a rubber composition containing a rubber component having a functional group containing a cationic functional group and/or an anionic functional group, a filler capable of generating a charge paired with the functional group, and sulfur.

The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in hardness over time. The present invention relates to a rubber composition containing a copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber composition having a heat aging resistance index defined by equation (1) of 10 or less.

The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in complex modulus E* over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 27 or less.

The present invention provides pneumatic tires which have reduced changes in hardness over time and which provide improved abrasion resistance while ensuring good durability. The present invention relates to a pneumatic tire formed from a rubber composition, the rubber composition containing: a rubber component including a hydrogenated copolymer containing a structural unit derived from an aromatic vinyl compound and a structural unit derived from a conjugated diene compound; and a liquid polymer having a number average molecular weight of 2,500 to 500,000, the hydrogenated copolymer being present in an amount of 80% by mass or less based on 100% by mass of the rubber component, the liquid polymer being present in an amount of 1 to 50 parts by mass per 100 parts by mass of the rubber component.

Pneumatic tire

The purpose is to provide rubber compositions and pneumatic tires which have reduced changes in tan δ over time. The present invention relates to rubber compositions containing at least one copolymer obtained by copolymerizing an aromatic vinyl compound and a conjugated diene compound, the rubber compositions having a heat aging resistance index defined by equation (1) of 2.0 or less.

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Kobe, Japan

Rie Yasuda