To provide a rubber composition for pneumatic tires which is improved in both modulus and low-heat generation performance through preparing its own simple composition, and is suitably used as a rubber composition or the like for covering steel cords of tires.
The rubber composition for pneumatic tires is prepared by compounding 30-70 pts.wt. of carbon black and 0.05-0.5 pt.wt., on a metal basis, of an organometal salt in 100 pts.wt. of a modified diene rubber comprising (A) 95-99 wt.% of a diene rubber and (B) 5-1 wt.% of such a thermoplastic elastomer with hydrogen bond-forming performance that the main chain consists of a diene rubber and there are carbonyl-containing groups and nitrogen-containing heterocyclic rings intramolecularly and the weight-average molecular weight Mw is 50,000 or lower. In the rubber composition, the thermoplastic elastomer with hydrogen bond-forming performance to be used is preferably a diene polymer that is prepared by successively reacting a carbonyl group-containing unsaturated compound and a nitrogen-containing heterocyclic compound substituted with functional groups reactive to the carbonyl groups with the polymer main chain consisting of the diene rubber.
CHINO KEISUKE
SHINOHARA YOSHIAKI
INOUE YOSHIHISA
TAKAHASHI TAKETO
Kazuko Yoshida