Patent ID: 7169848

Claim:
A block copolymer or hydrogenated block copolymer comprising: at least two blocks A and at least one block B of general configuration A-B-A, (A-B-A) n X or (A-B) n X, where n is an integer from 2 to 30, and X is residue of a coupling agent, wherein each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 60,000 and each block B is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene, wherein the total amount of mono alkenyl arene in the block copolymer is between 20 and 80 percent by weight, wherein the weight percent of mono alkenyl arene in each B block is between about 10 percent and about 75 percent, wherein each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units, and wherein each block B has a mono alkenyl arene blockiness index of less than 40 mol %, said mono alkenyl arene blockiness index being the proportion of mono alkenyl arene units in the block B having two mono alkenyl arene neighbors on the polymer chain and wherein the Young's modulus is less than 20 MPa and the rubber modulus between 100% and 300% elongation is greater than 0.5 MPa.