Rubber composition and tire
AssigneeSumitomo Rubber Industries, Ltd.
InventorKensuke Washizu
Life of this patent
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Abstract
The present invention aims to provide rubber compositions and tires which provide improved overall performance in terms of wet grip performance, dry grip performance, and fuel economy. The present invention relates to a rubber composition having a hardness that reversibly changes with water and satisfying the following relationships (1) and (2): Hardness when dry−Hardness when water-wet≥1 (1) wherein each hardness represents the JIS-A hardness at 25° C. of the rubber composition; and tan δ at 70° C. when dry<0.14 (2) wherein the tan δ at 70° C. represents the loss tangent measured at 70° C., an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz.
Claims15
A rubber composition, having a hardness that reversibly changes with water and satisfying the following relationships (1) and (2):
- Hardness when dry−Hardness when water-wet≥1 (1)
- wherein each hardness represents a JIS-A hardness at 25° C. of the rubber composition;
- and
- tan δ at 70° C. when dry<0.14 (2)
- wherein the tan δ at 70° C. represents a loss tangent measured at 70° C., an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz,
- wherein the rubber composition comprises a rubber component that includes isoprene-based rubber, polybutadiene rubber, and styrene-butadiene rubber,
- the amount of styrene-butadiene rubber based on 100% by mass of the rubber component is 20 to 95% by mass, and
- the amount of isoprene-based rubber based on 100% by mass of the rubber component is 3 to 20 phr.
Dependencies are inferred from the claim text.