Patent ID: 7271207
Filing Date: 2007-09-18
Classification: C08F,C08L

Abstract:
1. A bituminous composition for use in a self adhesive shingle or roofing felt, said composition comprising a bituminous component and a block copolymer, said block copolymer comprising at least two blocks of a conjugated diene and at least two blocks of a monovinylaromatic hydrocarbon of the general formula: wherein B 1 is a block of polymerized conjugated diene comprising at least 80 mole % isoprene having an apparent molecular weight of from 180,000 to 400,000, S 1 and S 2 are blocks of polymerized monovinylaromatic hydrocarbon comprising at least 99 mole % styrene and having a weight average molecular weight of 12,000 to 40,000, and B 2 is a block of polymerized conjugated diene comprising at least 80 mole % isoprene having an apparent molecular weight of from 15,000 to 60,000; wherein the weight ratio W of B 1 over B 2 is in the range of 3.0 to 12.0; and wherein the content of polymerized monovinylaromatic hydrocarbon is in the range from 10 to 35% wt.