Patent ID: 6858683

Claim:
A process for producing statistic elastomeric conjugated diene-vinyl arene copolymers having a branched structure which comprises: (1) anionic copolymerization in solution of the conjugated diene and vinyl arene monomers, in the presence of randomizing agents and an initiator selected from the group of lithium alkyls, the copolymerization being carried out until the total disappearance of the monomers; (2) addition to the solution of step (1) of a quantity of lithium alkyl from 1 to 4 times the molar quantity of the lithium alkyl of step (1); (3) addition to the polymeric solution of step (2) of a primary alkyl halide the having the general formula R—Br, the molar ratio between R—Br and the total lithium alkyl ranging from 0.6/1 to 1/1, wherein R is at least one monofunctional C 1 -C 30 hydrocarbyl radical, thus obtaining elastomeric branched copolymer.