Patent ID: 7375156

Claim:
A pneumatic tire having a tread formed of a rubber composition comprising: 100 parts by weight of a rubber component containing at least 5% by weight of natural rubber graft-copolymerized with an organic compound having an unsaturated bond and/or epoxidized natural rubber, and 5 to 150 parts by weight of silica with a nitrogen-absorbing specific surface area of 100 to 300 m 2 /g, and a silane coupling agent which fulfills the following formula (1) (C n H 2n+1 O) 3 —Si—(CH 2 ) m —S l —(CH 2 ) m —Si—(C n H 2n+1 O) 3 (1) wherein in said formula (1) n is an integer of 1 to 3, m is an integer of 1 to 4, l is an integer of 2 to 8 and the average value of l is 2.1 to 3.5, wherein protein within said natural rubber graft-copolymerized with an organic compound having an unsaturated bond and epoxidized natural rubbers, contains an amount of protein converted to nitrogen content of at most 0.10% by weight.