| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic runflat radial tire of a side reinforced type in which the runflat durability has drastically been increased without spoiling the actual vehicle performance such as a riding comfort performance. SOLUTION: The pneumatic runflat radial tire is equipped with a carcass layer 5, a main belt 8, a tread section 9, a side wall section 12 and a reinforcing rubber layer 13 having an approximately crescent-like cross sectional shape. In at least one sheet of a carcass ply cord of the carcass layer 5, a cord of which the thermal shrinking stress difference between 30°C and 80°C is 3.0×10<SP>-2</SP>cN/dtex or higher is used. The inclination α for the decreasing rate (%) of a dynamic storage elasticity E' from 30 to 50°C of the reinforced rubber layer 13 is represented by the following equation α≤-3.0×10<SP>-2</SP>(%)/(deg). Also, the inclination β for the decreasing rate (%) of the dynamic storage elasticity E' from 50 to 80°C is represented by the following equation β≥-8.0×10<SP>-2</SP>(%)/(deg). COPYRIGHT: (C)2008,JPO&INPIT |
