| 摘要 |
PURPOSE:To improve durability of a tyre by a method in which in the radial tyre having the belt layer composed of two ply steel cord, the belt layer is made of the piled layer consisting of an open ply steel cord with predermined elongation and an ordinary steel cord. CONSTITUTION:The outer ply of a belt layer uses the open ply steel cord in which the steel filaments with 0.10-0.40mm. diameter are twisted by 3-5 plys and 5-16mm. pitch and have the parts without Mutual adhering and then the elongation for a single cord at 0.2-5kg load is caused to be in the range of 0.2-0.6%. Then the ordinary steel cords having the elongation of 0-0.1% at the same load range as that of the outer ply are used for an inner ply. The liquid rubber such as polybutadiene of 2-30wt.pts. is mixed to the rubber component of 100pts, and this mixed rubber is used as filler rubber. Thus, the durability is improved. |
