RUBBERY COMPOSITIONS COMPRISING A BLEND OF POLYMERS OR COPOLYMERS OF CONJUGATED DIENES OR COPOLYMERS THEREOF WITH A VINYL-AROMATIC COMPOUND

摘要

A process for the polymerization of one or more conjugated dienes having 4 or 5 carbon atoms per molecule, with or without a vinylaromatic compound as comonomer in solution, characterized in that the polymerization is carried out partially in the presence of alkyllithium as initiator, followed by coupling by means of a coupling agent for the formation of a polymeric portion a, at least 60% by weight of which has been modified by branches comprising at least 20 monomer units each, and the polymerization is carried out partially in the presence of a ziegler catalyst or an alkyl lithium as an initiator and, if desired, followed by coupling by means of a coupling agent for the formation of a polymeric portion b, after which 40% is mixed. 94% by weight of the polymer portion a with 60 to 6% by weight of the polymer portion b, wherein the initiator of lithium alkyl, and, if the z catalyst is used iegler are used in such an amount that the mixture of a and b has an intrinsic viscosity within the range of 1.3 to 5dl/g and the ratio of the intrinsic viscosities of a and b amounts to at least 3 and does not exceed 50. . (Machine-translation by Google Translate, not legally binding)