Polybenzazolfiber og fremgangsmåde til fremstilling deraf

摘要

A polybenzazole fiber characterized by having an elastic modulus of not less than 1350 g/d and requiring not longer than 10 minutes to reduce its water content from 2.0% to 1.5%, when determined using a thermogravimetric analyzer at 110 DEG C after moisture absorption of not less than 2.0% of a fiber, and a method for manufacturing such a polybenzazole fiber, comprising extruding a spinning dope comprising polybenzazole and a polyphosphoric acid from a spinneret to give a dope filament, and cooling the dope filament to not more than 50 DEG C, followed by coagulation and washing. According to the method of the present invention, a polybenzazole fiber showing less decrease in strength by rapid heating can be provided.