| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic tire improved in durability during run-flat travelling without hindering riding comfort during normal travelling. SOLUTION: This pneumatic tire is provided with a pair of side reinforcing rubber layers 7 respectively having a crescent-shaped cross section inside a radial carcass 3 formed over from a butt-less part 5 to a side wall part 6. The reinforcing cord layer 8 formed by coating a polyketone fiber cord, which is formed by twisting a plurality of polyketone filament bundles and which satisfies condition of a formula (I) σ≥-0.01×E+1.2 and a formula (II) σ≥0.02 [in the formulas, σ means heat shrinkage stress (cN/dtex) at 177°C, and E means modulus of elasticity (cN/dtex) when 49 N load is applied at 25°C], with coating rubber in at least either of an area A formed over from a belt end part to the maximum width part of a tire side part and an area B formed over from a part near a bead core to a bead filler. COPYRIGHT: (C)2006,JPO&NCIPI |
