Patent ID: 7205360
Filing Date: 2007-04-17
Classification: C08F,C08L,Y10S

Abstract:
1. A preparation process for a copolymer, whether functional or not, having two blocks, which is usable in a sulphur-cross-linkable rubber composition of reduced hysteresis in the cross-linked state, one of said blocks being constituted of a polyisoprene and the other of a diene elastomer other than a polyisoprene, the molar ratio of units originating from conjugated dienes of which is greater than 15%, said process comprising copolymerizing one or more monomers comprising a conjugated diene other than isoprene using a catalytic system comprising at least one hydrocarbon solvent, a compound A of a metal of group IIIA, a compound B of an alkaline-earth metal and a polymeric initiator C comprising a C—Li bond which is constituted of a monolithiated polyisoprene intended to form said polyisoprene block, the number-average molecular weight M