Patent ID: 7893156
Filing Date: 2011-02-22
Classification: B32B,C08F,C08G,C08J,C08K,C08L

Abstract:
1. A block copolymer comprising styrene and a conjugated diene having a weight ratio of 60/40 to 90/10, wherein the number average molecular weight of said block copolymer, measured by gel permeation chromatography (GPC), is 30,000 to 500,000, wherein styrenes having an average polymerization degree of 30 or more have a block rate of from 10 to 90% by weight, said block rate being equal to the weight of styrenes having an average polymerization degree of 30 or more/the weight of the total amount of styrenes in the block copolymer×100, wherein the styrenes having an average polymerization degree of 30 or more have a peak molecular weight within the molecular weight range of 5,000 to 30,000 as measured by gel permeation chromatography (GPC), and wherein 45 to 80% by weight of the styrenes having an average polymerization degree of 30 or more have a molecular weight of 35,000 or less as measured by gel permeation chromatography (GPC).