| 摘要 |
PROBLEM TO BE SOLVED: To provide a composite fiber which enables production of a biodegradable ultra-fine fiber which has high high-order processing passability while allowing long-term storage.SOLUTION: In a sea-island composite fiber, an island component 'a' is composed of a biodegradable polymer, and a sea component 'b' is composed of a polyester containing ethylene terephthalate as the main repeating unit. The polyester is a polyester composition comprising 1.0-20.0 mol%, relative to the total of dicarboxylate constituents, of a 5-sodium sulfoisophthalate constituent and 0.1-20.0 mol% of an isophthalate constituents, and the content of polyethylene glycol to the polyester composition is 0.1-20.0 wt.%. The sea-island composite fiber has a peak top temperature of tanδ of 90°C or higher and a peak value of 0.35 or smaller.SELECTED DRAWING: Figure 2 |
