Patent ID: 7910208

Claim:
A bicomponent fiber comprising a thermoplastic polymer sheath and an elastomeric compound core wherein the elastomeric compound core comprises a selectively hydrogenated block copolymer having an S block and an E or E1 block and having the general formula: S-E-S, (S-E 1 ) n , (S-E1) n S, (S-E1) n X or mixtures thereof, wherein: a. Prior to hydrogenation the S block is a polystyrene block; b. Prior to hydrogenation the E block is a polydiene block, selected from the group consisting of polybutadiene, polyisoprene and mixtures thereof, having a molecular weight from 40,000 to 70,000; c. Prior to hydrogenation the E 1 block is a polydiene block, selected from the group consisting of polybutadiene, polyisoprene, and mixtures thereof, having a molecular weight from 20,000 to 35,000; d. N has a value of 2 to 6 and X is the residue of a coupling agent; e. The styrene content of the block copolymer is from 13 to 25 weight percent; f. The vinyl content of the polydiene block prior to hydrogenation is from 70 to 85 mol percent; g. The block copolymer includes less than 15 weight percent of units having the general formula: S-E or S-E 1 Wherein S, E and E 1 are as already defined; h. Subsequent to hydrogenation about 0 to 10% of the styrene double bonds have been hydrogenated and at least 80% of the conjugated diene double bonds have been hydrogenated; i. The molecular weight of each of the S blocks is from 5,000 to 7,000; and j. The melt index of the block copolymer is greater than or equal to 12 grams/10 minutes according to ASTM D1238 at 230 C and 2.16 kg weight.