Patent ID: 7585916

Claim:
A block copolymer composition comprising: (a) 100 parts by weight of a solid hydrogenated controlled distribution block copolymer having the general configuration A-B, A-B-A, (A-B) n , (A-B-A) n , (A-B-A) n X, (A-B) n X or mixtures thereof, where n is an integer from 2 to about 30, and X is coupling agent residue and wherein: i. prior to hydrogenation each A block is a mono alkenyl arene polymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene having a blockiness index (I 1 ) of less than about 40 percent; ii. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced; iii. each A block having a peak molecular weight between about 3,000 and about 60,000 and each B block having a peak molecular weight (MW 1 ) between about 30,000 and about 300,000; iv. 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; v. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 20 percent weight to about 80 percent weight; and vi. the weight percent of mono alkenyl arene in each B block (S 1 ) is between about 5 percent and about 75 percent; and (b) 5 to 250 parts by weight of a hydrogenated tailored softening modifier which is structurally related to the character of the B block of said controlled distribution block copolymer wherein: i. said softening modifier contains at least one conjugated diene and at least one mono alkenyl arene having a blockiness index I 2 , such that the ratio of I 2 /I 1 is between 0.1 and 10.0; ii. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced; iii. the ratio (MW 2 )/(MW 1 ) of the peak molecular weight of said softening modifier (MW 2 ) to the peak molecular weight of said B block of said controlled distribution block copolymer (MW 1 ) is 0.01 to 1.0, with a minimum molecular weight (MW 2 ) of 2,000; iv. the weight percent of mono alkenyl arene in each softening modifier (S 2 ) is between about 5 percent and about 75 percent and the ratio of S 2 /S 1 is between 0.5 and 1.5; and (c) wherein said softening modifier is formed in solution in the presence of a solvent in a second reactor to form a second solution and combined with a first solution prepared in a first reactor to form a common solution, wherein said controlled distribution block copolymer is polymerized in said first solution or said common solution, and (d) the solvent is removed from the common solution subsequent polymerization of the controlled distribution block copolymer, providing an intimate mixture of said controlled distribution block copolymer and said tailored softening modifier.