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US 4,822,844 AGranted
Rubber compositions
AssigneeThe Yokohama Rubber Co., Ltd.
InventorsKinya Kawakami, Takao Muraki
Life of this patent
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Abstract
Rubber compositions particularly for use in automobile tire treads comprise a selected class of starting rubbers and specified amounts of a selected types of carbon black, this filler having specified values of IA, N.sub.2 SA/IA and .DELTA.D.sub.50 (Dst). The resulting tire excels in abrasion resistance, rebound resilience, antiskidding on wet, snowy and icy roads and fuel economy thus contributing to efficient and safe driving in all seasons.
Claims4
A rubber composition comprising:
- (a) a starting rubber comprising from 20 to 80 parts by weight of at least one rubber selected from the group consisting of natural rubber and synthetic polyisoprene rubber, and from 80 to 20 parts by weight of styrene-butadiene rubber having a styrene content of 10 to 30 percent by weight and a 1,2-vinyl bond content of from 10 to 80 percent by weight, said styrene-butadiene rubber containing either in the molecular chain or at the terminal end thereof at least one atomic group of the formula ##STR5## wherein X is OH or SH, the total amount of said starting rubber being 100 parts by weight;
- and
- (b) from 30 to 80 parts by weight of carbon black per 100 parts of starting rubber, said carbon black having an iodine adsorption of from 60 to 70 mg/g, a specific surface area ratio of nitrogen adsorption to iodine adsorption of from 1.18 to 1.40 and a median width of Stokes' particle size distribution of from 70 to 130 millimicrons.
Dependencies are inferred from the claim text.