| abstract |
(57) [Summary] [Purpose] To provide a core-sheath type composite fiber having excellent elastic properties and peel resistance. A block copolymer comprising an isoprene polymer block B having a hydrogenation rate of 80% or more and a styrene polymer block A, the block A accounting for 10 to 50% by weight is used as a core component, and the block copolymer is used. A core-sheath containing a fiber-forming thermoplastic polymer having a difference in solubility parameter of 1 or more as a sheath component, and containing an olefinic compound in an amount of 20% by weight (based on the weight of the fiber) in the core component or the sheath component. Type composite fiber. |