| abstract |
A rubber composition for use in pneumatic tires in which a silica having BET specific surface area=190 to 300 m 2 /g and a CTAB specific surface area=140 to 300 m 2 /g is blended by more than 100 parts by weight and 200 parts by weight or less based on 100 parts by weight of a rubber ingredient containing 50% by weight or more of a styrene-butadiene copolymer rubber having a glass transition point≧−40° C., a styrene content≧30% by weight, and a weight average molecular weight≧800000, and a silane coupling agent of the following formula (1) is blended by from 2 to 25 parts by weight based on 100 parts by weight of the silica: n n(C n H 2n+1 O) 3 Si—C m H 2m —S—CO—C k H 2k+1 (1) nin which n is an integer of 1 to 3, m is an integer of 1 to 5, and k is an integer of 5 to 9. |