| 摘要 |
PROBLEM TO BE SOLVED: To provide a pneumatic radial tire improved in steering stability and high-speed durability while reducing cost and weight. SOLUTION: In the pneumatic radial tire, a belt layer 7 in which cords are arranged so as to be tilted with respect to a tire circumferential direction, and a belt reinforcing layer 8 in which cords are arranged along the tire circumferential direction at the outer periphery of the belt layer are disposed at the outer periphery of a carcass layer 6 in a tread section 2. As the cords constituting the belt reinforcing layer, polyolefin ketone fiber cords of single twist structures are used which are formed by twisting yarn formed by bundling polyolefin ketone filaments having a nominal fineness of 1000-2000 dtex so as to become 1000-3000 in a twist coefficient K defined by T(D/1.30)<SP>1/2</SP>wherein T is the number of twists per 10cm-length, and D is nominal fineness. COPYRIGHT: (C)2010,JPO&INPIT |
