| 摘要 |
PURPOSE:To provide sufficient ice property from the start of initial use by cure-forming the outer surface of a tread made of elastic members in which particles or bubbles are diffused in a cure mold with a surface roughness Ra within a specified limit at the internal tread position of the mold. CONSTITUTION:A pneumatic tire 1 is provided with a circular tread 2 in contact with the ground and side walls 5 extending from shoulder sections 2a on both sides of the tread and covering the sides of a tire from the shoulder sections 2a to bead sections 3. In this case, a surface roughness Ra on both outer surfaces 2C of the ground-contact sections 2b and the shoulder sections 2a of the tread 2 is set at, for example, 15mum in circumferential direction for a new tire after vulcanization. Also, a surface roughness Ra of the tread 2 at a position 2mm higher from the groove bottom 2d of the tread 2 is set, for example, 9mum. Thus the tire is cure-formed in the cure-mold with a surface roughness Ra satisfying the equation 8mum<=Ra on at least the internal surface of the tread of the mold. |
