| abstract |
The present invention provides a rubber composition for tires, which has improved processability and wear resistance. The rubber composition for tires according to the present invention comprises a polybutadiene (i), another rubber (ii) and a rubber reinforcing material (iii), wherein the polybutadiene (i) meets the following requirements: (A) the Mooney viscosity (ML 1+4,100˚C ) is 43 or more; (B) the ratio of the Mooney viscosity (ML 1+4,100ºC ) to the viscosity in a 5-wt% solution in toluene (Tcp) (i.e., Tcp/ML 1+4,100ºC ) is 0.9 to 2.3; (C) the stress relaxation time (T80), which is a time the value of a torque takes to decay by 80%, is 10.0 to 40.0 seconds, wherein the value of a torque determined at the completion of the measurement of the ML 1+4,100ºC value is 100%; and (D) the molecular weight distribution (Mw/Mn) is 2.50 to 4.00. |