Rubber compositions for base tread and tires using the same
AssigneeSumitomo Rubber Industries, Ltd.
InventorsToshiro Matsuo, Naohiko Kikuchi
Life of this patent
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Abstract
Rubber composition for a base tread, which is obtainable by blending, per 100 parts by weight of a rubber component, 30 to 55% by weight of a carbon black having an iodine adsorption value of from 40 to 100 g/kg, wherein the rubber component comprises (A) 20 to 55% by weight of a star shaped solution-polymerized butadiene rubber and (B) 45 to 80% by weight of a natural rubber or a natural rubber containing a diene rubber other than a star shaped solution-polymerized rubber in an amount of not more than 50% by weight. When using the above-mentioned rubber composition for the base tread of a base portion of a tread having a cap/base two-layer structure, it is possible to save fuel consumption of the tire because of small deformation and uniform shape.
Claims8
A rubber composition for a base tread, which is obtainable by blending, per 100 parts by weight of a rubber component, 30 to 55 parts by weight of a carbon black having an iodine adsorption value of from 40 to 100 g/kg, said rubber component comprising
- (A) 20 to 55% by weight of a star shaped solution-polymerized polybutadiene rubber having a rate of coupling with tin tetrachloride of not less than 25% and a molecular weight distribution (weight average molecular weight/number average molecular weight) of 1.2 to 3, and
- (B) 45 to 80% by weight of a natural rubber or a natural rubber containing a diene rubber other than a star shaped solution-polymerized rubber in an amount of not more than 50% by weight.
Dependencies are inferred from the claim text.