| 摘要 |
<p>A pneumatic tire which is used for a vehicle and obtained after a rubber material is formed by vulcanization. A cap portion (12A), which is an upper layer of a tread and directly contacts the road surface, is a foam rubber which includes innumerable elongated closed cells (24). The outer portion of the elongated closed cell (24) is coated by a resinous protective layer (26). During the vulcanization process of the tire, a resin whose viscosity is lower than that of a rubber matrix and a blowing agent which generates gas are kneaded with a rubber material so as to obtain a rubber composition. The rubber composition is formed in the shape of a band and adhered to a crown portion of a raw tire casing. The resin is melted by the heat of vulcanization and the viscosity of the resin is lower than that of the rubber matrix. The gas generated in the rubber moves toward and concentrates at the inner side of the resin. Accordingly, an elongated closed cell (24) whose outer portion is provided with the resinous protective layer (26) is formed. <IMAGE></p> |
