caoutchoucteuses compositions and their preparation

摘要

A composition comprising a blend consisting of polymers or copolymers of one or more conjugated dienes having 4 or 5 carbon atoms per molecule, or copolymers thereof with a vinylaromatic compound, wherein one portion (A) consists of at least 60% by weight of components which have been modified by branchings comprising at least 20 monomer units each, while another portion (B) consists of similarly modified branched and/or linear components, with the proviso, that the intrinsic viscosity of the blend of A and B is within the range of from 1.3 to 5 dl/g, the ratio of the intrinsic viscosities of A and B amounts to at least 3 and does not exceed 50, and the amount of portion A in the blend lies within the range of from 40 to 94% by weight. The composition of the present invention is useful for many important applications, particularly as base materials in the manufacture of heavy-duty tires for automotive vehicles.