Rubber compositions and pneumatic tires using the same

摘要

Rubber compositions and pneumatic tires in which the rubber compositions are used. In the rubber compositions, per 100 parts by weight of natural rubber and a conjugated diene-base synthetic rubber such as a butadiene-styrene copolymer rubber, is compounded 30 to 120 parts by weight of a carbon black having both a characteristic (concentration of >C=O functional groups)/N2SA >/= 4.0 x 10<-4> and a characteristic (concentration of >C=O functional groups) >/= (concentration of -OH functional groups)<2> - 0.1 x (concentration of -OH functional groups)+0.03, or is compounded 30 to 120 parts by weight of a carbon black having the characteristic (concentration of >C=O functional groups)/N2SA >/= 4.0 x 10<-4> and 0.05 to 5.0 parts by weight of at least one of a silane coupling agent, a hydrazide compound and a thiadiazole compound. The rubber compositions of the present invention and pneumatic tires using the rubber compositions excel in low rolling resistance and wet skid resistance.