PRECURSOR FIBER FOR CARBON FIBER, METHOD FOR PRODUCING THE SAME AND METHOD FOR PRODUCING ULTRAFINE CARBON FIBER

摘要

PROBLEM TO BE SOLVED: To provide a precursor fiber for a carbon fiber, having excellent processability in flameproofing process and reduced environmental load in carbonizing process and giving a carbon filament composed of an aggregate of ultrafine carbon fibers and having excellent handleability by carbonization and provide a method for producing the precursor fiber in high productivity while decreasing the load on the environment. SOLUTION: The precursor fiber for carbon fiber is a continuous yarn composed of aggregate of ultrafine polyacrylonitrile fibers having an average diameter of <1μm and made of a polyacrylonitrile copolymer. The weight ratio of the ultrafine polyacrylonitrile fiber in the continuous yarn is≥80 wt.% and <98 wt.% and the diameter of the continuous yarn is≤30μm. The method for producing the precursor fiber comprises the mixing and spinning of≤30 wt.% polyacrylonitrile copolymer and≥70 wt.% polymer soluble in a solvent and the dissolution of the solvent-soluble polymer from the obtained fiber by using a solvent. COPYRIGHT: (C)2007,JPO&INPIT