CORE-SHEATH COMPOSITE FIBER AND METHOD FOR PRODUCING SAME

摘要

Provided are a core-sheath composite fiber and a woven object in which peeling of a composite interface can be inhibited in the process of spinning a polyester and polyamide core-sheath composite fiber, fluffing and yarn breakage can be considerably mitigated, and elution of the polyester in an alkali can be considerably improved. Also provided are an ultrafine polyamide fiber, a woven object, and a textile product obtained by dissolving and removing the polyester included in the core-sheath composite fiber. The core-sheath composite fiber is characterized in having a polyamide as a sheath component and having as a core component a polyester that is readily eluted in an alkali, the polyester containing 2.0-5.5 mol% of an isophthalic acid component with respect to the total acid component and 3.0-6.0 mol% of an adipic acid component relative to the total acid component, the isophthalic acid component containing metal sulfonate groups, and the main repeating units of the polyester being constituted of ethylene terephthalate.