MOISTURE-ABSORBING OR RELEASING POLYESTER CONJUGATE FIBER

摘要

PROBLEM TO BE SOLVED: To provide a polyester conjugate fiber not causing the problem of sheath cracking by a caustic reduction treatment, giving a treated conjugate fiber having an excellent moisture-absorbing or releasing property at high temperature and high humidity, and further having excellent light resistance. ;SOLUTION: This conjugate fiber comprises a moisture-absorbing or releasing thermoplastic resin in a core portion 3, a polyester resin in an intermediate portion 2 and an easily alkali-soluble resin in a sheath portion 1, and has a hollow portion 4 brought into contact with the core portion. The core portion/intermediate portion weight ratio of the conjugate fiber is 30/70 to 90/10, and the rate (hollowness rate) of the hollow portion occupied in the cross section of the conjugate fiber is ≥5%. The moisture absorption of the conjugate fiber after subjected to a caustic reduction treatment to dissolve the sheath portion satisfies the following (1) to (4). (1) The moisture absorption R1 is ≤1.4%, after left at 20°C in a RH of 65% for 24 hr. (2) The moisture absorption R2 is ≥2.5%, after left at 34°C in a RH of 90% for 2 hr. (3) The moisture absorption R3 is ≥4.5%, after left at 34°C in a RH of 90% for 24 hr. (4) The moisture absorption R4 is ≤2.5%, after left at 20°C in a RH of 65% for 2 hr., after subjected to the moisture absorption of (3).;COPYRIGHT: (C)2000,JPO