Patent ID: 8734614
Filing Date: 2014-05-27
Classification: D01D,D01F,D04H,D21H

Abstract:
1. A polyphenylene sulfide fiber having an amount of heat of crystallization determined by measuring an amount of calorific value of a main exothermic peak observed during a first temperature elevation (first run) when temperature is raised in nitrogen at a heating rate of 10° C./minute with a differential scanning calorimeter of 10 or more J/g and a degree of shrinkage on dry heating of 150° C. for 30 minutes of 20% or less, wherein the polyphenylene sulfide fiber is obtained by subjecting a polyphenylene sulfide fiber spun at a spinning rate of 500 m/min to 3000 m/min to heat treatment at a temperature that is equal to or lower than a crystallization temperature of the polyphenylene sulfide fiber before heat treatment determined by measuring the temperature of a main exothermic peak observed by raising the temperature in nitrogen at a heating rate of 10° C./minute using a differential scanning calorimeter, wherein the heat treatment is carried out without drawing the polyphenylene sulfide fiber or subjecting it to heat fixation.