Rubber composition for tires containing block copolymer having vinyl bonds
AssigneeBridgestone Tire Company Limited
InventorsTatsuo Fujimaki, Tomoharu Yamada, Seisuke Tomita
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Abstract
A rubber composition adapted to be used as a tread rubber is disclosed. The rubber composition has remarkably improved resistance against heat generation, breakage resistance, wear resistance, wet skid resistance and low-temperature brittleness, and consists mainly of a rubber blend consisting of 20-95 parts by weight of a styrene-butadiene block copolymer having a specifically limited structure and 80-5 parts by weight of a diene rubber.
Claims2
A rubber composition for tires, consisting mainly of a rubber blend consisting of 20-95 parts by weight of a styrene-butadiene block copolymer and 80-5 parts by weight of a diene rubber;
- said styrene-butadiene block copolymer being a copolymer obtained by block copolymerizing styrene with 1,3-butadiene, consisting of a random copolymer block (A) and a random copolymer block (B), the fraction of the copolymer block (A) being 10-90% by weight, and having a total bonded styrene content of 10-40% by weight and a total vinyl bond content in the total bonded butadiene unit of 25-70% by weight;
- said random copolymer block (A) having a bonded styrene content of 20-50% by weight and a vinyl bond content in the butadiene unit of 40-75% by weight;
- and said random copolymer block (B) having a bonded styrene content of not higher than 10% by weight and a vinyl bond content in the butadiene unit of 20-50% by weight.
Dependencies are inferred from the claim text.