Rubber composition for tire tread

摘要

Rubber compositions for tire treads well balanced in the performances of rolling registance, sliding coefficient of friction on wet road surfaces and wear resistance and which are superior in the processability and workability, including at least 20 parts by weight of styrene-butadiene random copolymer prepared by using an organic lithium as a polymerization catalyst and coupled with a mono- or difunctional tin compound as well as a tri- or more functional compound and having a tin content of 300 ppm or more which is bonded to the polymer and further include a carbon black having the value of N2 SA/IA of 1.1 or more.