Method of preparation of copolymers of 1,3-butadiene and styrene useful for the production of tires with low rolling resistance and copolymers of 1,3-butadiene and styrene thus obtained

摘要

A method of preparation of copolymers of 1,3-butadiene and styrene, useful for the production of tires or elastic materials, characterized by a reduced rolling resistance without detriment to other properties such as skid resistance. The copolymer is prepared using anionic polymerization of 1,3-butadiene and styrene and coupling of part of the chains in star shape with an appropriate compound of tin or silicon, terminating the remainder of the linear chains without coupling using an appropriately selected different compound. The presence of these linear chains terminated with tin yields a beneficial effect in the reduction of rolling resistance when said product is used in tire formulations. The invention also concerns the copolymers of 1,3-butadiene and styrene obtained by said method.