Patent ID: 6660790
Filing Date: 2003-12-09
Classification: C08K,C08L

Abstract:
A styrene polymer composition comprising:(I) a styrene/n-butyl acrylate copolymer comprising 80 to 89% by weight of styrene monomer units and 20 to 11% by weight of n-butyl acrylate monomer units; and (II) a branched block copolymer comprising 65 to 85% by weight of vinyl aromatic hydrocarbon monomer units and 35 to 15% by weight of conjugated diene monomer units, said branched block copolymer (II) having a block configuration comprising at least one vinyl aromatic hydrocarbon polymer block and at least one polymer block selected from the group consisting of at least one conjugated diene polymer block and at least one vinyl aromatic hydrocarbon/conjugated diene copolymer block, wherein said at least one vinyl aromatic hydrocarbon polymer block of said branched block copolymer (II) exhibits, in a gel permeation chromatogram thereof, at least one peak molecular weight in the range of from 5,000 to 30,000 and at least one peak molecular weight in the range of from 50,000 to 150,000, wherein said branched block copolymer (II) has a vinyl aromatic hydrocarbon block ratio of from more than 90 to 100% by weight, wherein said vinyl aromatic hydrocarbon block ratio is defined as the percent by weight of the vinyl aromatic hydrocarbon monomer units contained in said at least one vinyl aromatic hydrocarbon polymer block, based on the total weight of vinyl aromatic hydrocarbon monomer units contained in said branched block copolymer (II), and wherein the weight ratio of said styrene/n-butyl acrylate copolymer (I) to said branched block copolymer (II) is from 10/90 to 90/10.