Patent ID: 6844383
Filing Date: 2005-01-18
Classification: C08F,C08K,C08L

Abstract:
1. A block copolymer comprising: at least two S polymer blocks, each comprising at least 70% by weight of vinyl aromatic hydrocarbon monomer units, and one or more B polymer blocks selected from the following polymer blocks (a), (b) and (c): wherein: the amount of the vinyl aromatic hydrocarbon monomer units in said block copolymer and the total amount of the isoprene monomer units and the 1,3-butadiene monomer units in said block copolymer being, respectively, from 60 to 95% by weight and from 40 to 5% by weight, each based on the weight of said block copolymer, said block copolymer having an isoprene monomer unit/1,3-butadiene monomer unit weight ratio of from 45/55 to 97/3, and wherein the vinyl aromatic hydrocarbon monomer unit moiety of said block copolymer has a short segment ratio of from 0 to 30 % by weight, wherein said short segment ratio is defined as the weight percentage, based on the total weight of vinyl aromatic hydrocarbon monomer units contained in said block copolymer, of the vinyl aromatic hydrocarbon monomer units contained in at least one short segment consisting of 1 to 3 vinyl aromatic hydrocarbon monomer units.