ULTRAFINE FIBER PRECURSOR, ULTRAFINE FIBER ASSEMBLY OBTAINED THEREFROM AND THEIR PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce polyester-based ultrafine fibers having a touch feeling of a cellulose ester or cellulose by spinning the fiber's with usual single melt spinning equipment for spinning filaments without using complicated melt spinning equipment. SOLUTION: This ultrafine fiber precursor comprises 50-90wt.% cellulose ester containing a plasticizer for the cellulose ester in an amount of 15-35% based on the cellulose ester and 50-10wt.% polyester as components. A part of the cellulose ester part in the ultrafine fiber precursor of separated phases in which the cellulose ester is separated into the form of the sea and the polyester is separated into the form of islands in an optional cross section in the direction at right angles with the fiber axis is removed to afford ultrafine fibers.