Patent ID: 8534333

Claim:
A pneumatic tire comprising: tread rubber made from a rubber composition containing 100 parts by weight of a diene rubber, 30 to 100 parts by weight of a reinforcing filler including at least 10 parts by weight of silica, and 1 to 20 parts by weight of microcapsules each encapsulating a heat-expandable substance, the rubber composition containing a sulfur-containing silane coupling agent in an amount of 3 to 15 wt. % based on the weight of the silica; each microcapsule comprising a shell material made of a thermoplastic resin obtained by polymerizing together a nitrile monomer (I) in a major proportion and a monomer (II) having an unsaturated double bond and a carboxyl group in its molecule; the heat-expandable substance having a vapor pressure of 1.4 to 3.0 MPa at 150° C.; the microcapsules having an average particle diameter of 20 to 30 μm before vulcanization of the rubber composition; the microcapsules as expanded due to the vulcanization having an average particle diameter of 40 to 80 μm; and the tread rubber having a proportion of a cell-occupying area of 5 to 30%.