RUBBER COMPOSITION FOR LARGE-SIZED PNEUMATIC BIAS TIRE AND LARGE-SIZED PNEUMATIC BIAS TIRE USING THE SAME

摘要

PPROBLEM TO BE SOLVED: To provide a low heat buildup rubber composition by optimizing a relation between the modulus of elasticity of a breaker coating rubber and the modulus of elasticity of a carcass ply coating rubber, and to provide a large-sized pneumatic bias tire using the same and excellent in weather resistance. PSOLUTION: The invention relates to the rubber composition for breaker coating (A) and for carcass ply coating (B) of the large-sized pneumatic bias tire satisfying following terms, (a) the coating rubber (A) manifests ≥2.5 MPa of tensile stress at 100% of elongation (100% Mod) and ≥500% of fracture elongation, (b) the coating rubber (B) manifests ≥2.5 MPa of tensile stress at 100% of elongation (100% Mod) and ≥350% of fracture elongation, and (c) the ratio R of tensile stress at 100% elongation of the coating rubber (B) to that of the coating rubber (A) [100% Mod(B)/100% Mod(A)] is 1.0≤R≤1.6. PCOPYRIGHT: (C)2007,JPO&INPIT