PRODUCTION OF ULTRAFINE FIBER

摘要

PURPOSE:To provide a method for producing ultrafine fibers by using a readily water-soluble polymer without no risk in the process in a significantly shortened time. CONSTITUTION:The objective ultrafine fibers can be obtained by spinning (A) a polyester or polyamide and (B) a high-molecular weight compound >=10000 in weight-average molecular weight produced by reaction of a diisocyanate with a polyalkylene oxide compound prepared by addition polymerization of an alkylene oxide such as ethylene oxide to an organic compound bearing two active hydrogen groups, in such a state that the resultant fibers have a cross-section having plurally divided domains, followed by removing the component B with water.