| 摘要 |
PURPOSE:To aim at a drastic weight lightening of a tire bead and improve low fuel consumption by using a complex cord, which is a combination of a fiber made from a heterocycle contained aromatic polymer containing a specific fiber strength and a polyamide resin through a specific mode, as a bead wire. CONSTITUTION:A complex cord of a fiber made from a hetrocycle contained aromatic polymer of a fiber strength of 18g/D or more and a polyamide resin is used as a bead wire for a radial tire. This complex cord is formed by completely coating a PBO fiber, which is the core material, with a polyamide resin and the volumetric ratio of the fiber in one bead wire is set within the range of 30% to 70%. The above mentioned resin coated wire is further formed so that it can be held by leaving a space between them with an insulation rubber which rubber hardness is 82 to the like are used as a fiber made from a heterocycle contained aromatic polymer. |
