66 6 An Excellent Fatigue Resistance Tire Cord using Nylon 66 or Nylon 6 and Aramid and Radial Tires Produced by the Same

摘要

The present invention relates to a process for producing a hybrid dipped cord using a nylon 6,6 yarn and an aramid yarn. The present invention relates to a process for producing a dipped cord, in which a nylon 6,6 yarn and an aramid yarn are pre-twisted by using at least one of a method of controlling tension applied to the raw cord, a method of adjusting a heat treatment temperature, and a method of controlling a heat treatment time, and the nylon 6,6 yarn and the aramid yarn are combined and twisted to form the raw cord, and then the raw cord is dipped in an adhesive and subject to the heat-treatment process such that the nylon 6,6 yarn is more shrunk. Another object of the present invention is to provide a hybrid dipped cord for a carcass ply layer or a cap ply layer of a pneumatic radial tire having a predetermined fatigue resistance, which is produced by dipping a raw cord using a nylon 6,6 yarn and an aramid yarn in an adhesive and heat-treating the raw cord such that the nylon 6,6 yarn is more shrunk. According to the present invention, the raw cord is produced in a state in which the twisted aramid yarn and nylon yarn are kept at the same twist level, and the raw cord is subject to a heat treatment process, so that the nylon yarn is shrunk and the aramid yarn is longer than the nylon yarn per unit length when the dipped cord is released, thereby improving the fatigue resistance. According to the present invention, it is possible to overcome the conventional disadvantages, such as difficulty of deformation in a mold due to the high modulus when the aramid is used alone, it is possible to improve the low fatigue resistance and low adhesion occurring when the aramid is used alone, and it is possible to manufacture high performance tires by improving low modulus and low heat resistance which may occur when the nylon 6.6 is used alone.