Organic fiber cords for rubber reinforcement and pneumatic radial tires using the same

摘要

An organic fiber cord for rubber reinforcement satisfies relationships of S1≥2.5, S2≤1.8 and S2≤S1-2.0 wherein S1 and S2 are dry heat shrinkage factors (%) at a temperature of 177 DEG C under a load of 0.03 g/d and 0.10 g/d respectively, in order to improve the durability and dimensional stability of rubber articles without the degradation of other properties in the rubber article. When such an organic fiber cord is applied to a carcass ply of a pneumatic radial tire, the tire durability and uniformity are considerably improved.