| 摘要 |
<p>In a pneumatic tire for vehicles produced by vulcanizing and molding a rubber material, a cap portion (12A) of the upper layer of a tread which comes into direct contact with a road surface is made of a foamed rubber having a large number of elongated closed cells (24). The outer peripheral portion of the elongated closed cell (24) is reinforced by a protective layer (26) of a resin. A material whose viscosity becomes lower than that of a rubber matrix and a foaming agent generating a gas in a tire vulcanization process are kneaded with the rubber raw material to obtain a rubber composition, and after this composition is shaped into a web form, it is bonded to the crown portion of a green tire case. The resin is molten by the heat of vulcanization, its viscosity becomes lower than that of the rubber matrix, the gas generated inside the rubber moves into, and concentrates on, the molten resin, so that the elongated closed cells (24) each equipped with the resin protective layer (26) over their outer peripheral portion can be formed.</p> |
