Block copolymer blends with improved oil absorption resistance

Claim 1

A thermoplastic blend, comprising: (a) about 80 to about 20 parts by weight of an elastomeric block copolymer having the general configuration A-B-A, wherein: (i) each A block is a polymerized monoalkenyl aromatic hydrocarbon block having an average molecular weight of about 4000 to about 115,000; (ii) the A blocks, in combination, comprise about 5 to about 35w% of the elastomeric block copolymer; and (iii) each B block is a non-hydrogenated butadiene hydrocarbon block consisting of 8 to 55 mole percent condensed butadiene units in the 1,2 configuration, or a hydrogenated butadiene hydrocarbon block consisting of 35 to 55 mole percent condensed butadiene units in the 1,2 configuration, and said B block has an average molecular weight of between about 20,000 and about 450,000; and (b) about 20 to about 80 parts by weight of a block copolymer having the general configuration A-B-A wherein: (i) each A block is a polymerized monoalkenyl aromatic hydrocarbon block having an average molecular weight of about 4000 to about 115,000; (ii) said A blocks, in combination, comprise about 5 to about 35 w % of the block copolymer; (iii) each B block is a polymerized butadiene hydrocarbon block consisting of about 18 to 34 mole percent condensed butadiene units in the 1,2 configuration, and said B block has an average molecular weight of between about 20,000 and about 450,000; and (iv) the B blocks are hydrogenated to an unsaturation that is less than about 5% of the original unsaturation.