| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire satisfying steering stability, durability, and weight reduction in high dimensions. SOLUTION: The pneumatic tire includes a tread section 10, a sidewall section 20, and a bead section 30, and further includes a bead core 1 embedded in the bead section 10, and at least a layer of carcass 3 secured around a bead filler 2 by folding it back from inside to outside. The height of the terminal end of a winding portion 3b of the carcass reaches 25-40 mm from the lower end of the bead filler. The fiber cord constituting the carcass 3 is a polyketone fiber satisfying the following expression (I):σ≥-0.01×E+1.2, and the expression (II):σ≥0.02 (in these expressions (I) and (II),σis a thermal shrinking stress (cN/dtex) at 177°C, and E is an elastic modulus (cN/dtex) when 49 N load is applied at 25°C). The cord constituting a side reinforcing layer 5 of the sidewall section 20 is an alamid fiber whose elastic modulus is 170-300 cN/dtex. The upper end of the side reinforcing layer 5 is overlapped inside an innermost belt layer, and the lower end thereof extends outside the winding portion 3b of the carcass. COPYRIGHT: (C)2011,JPO&INPIT
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