Patent ID: 7625983
Filing Date: 2009-12-01
Classification: C08F,C08L

Abstract:
1. A process for the preparation of a functionalized, coupled or starred block copolymer which is usable in a sulphur-cross-linkable rubber composition comprising carbon black and of reduced hysteresis in the cross-linked state, at least one of said blocks consisting of a polyisoprene and at least one other block consisting of a diene elastomer other than a polyisoprene the molar ratio of units originating from one or more conjugated dienes of which is greater than 15%, wherein said process comprises: (i) copolymerization of one or more monomers comprising at least one conjugated diene other than isoprene using a catalytic system comprising a hydrocarbon solvent, a compound A of a metal of group IIIA, a compound B of an alkaline-earth metal and a polymer initiator C comprising a C-Li bond which is formed of a monolithiated non-functionalized polyisoprene intended to form said or each polyisoprene block, said polyisoprene block(s) having a number-average molecular weight M (ii) addition to the product of said copolymerization of a functionalizing, coupling or starring agent comprising one, two or at least three epoxy groups respectively, so that said block formed of a diene elastomer other than a polyisoprene is functionalized, coupled or starred.