Patent ID: 6759454
Filing Date: 2004-07-06
Classification: C08F,C08L,C09D,C09J

Abstract:
A bituminous composition comprising:I) from about 75 percent to about 99.5 percent bitumen; and II) from about 0.5 percent to about 25 percent weight of a block copolymer having at least one A block and at least one B block wherein: a) each A block is a mono-alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono-alkenyl arene; b) each A block having a number average molecular weight from about 3,000 and about 60,000 and each B block having a number average molecular weight from about 30,000 and about 300,000; c) each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono-alkenyl arene units; d) the total amount of mono-alkenyl arene in the block copolymer is about 20 percent weight to about 80 percent weight; and e) the weight percent of mono-alkenyl arene in each B block is from about 10 percent to about 75 percent.