High-strength polyvinyl alcohol fiber and a manufacturing method thereof excellent in moist heat resistance

摘要

PURPOSE: To obtain the subject fiber suitable as a reinforcing material for cement products made by curing in high-temperature autoclave or rubbers or plastics to be exposed to water or moist heat for a long period. ;CONSTITUTION: A spinning dope prepared by dissolving a polyvinyl alcohol, 99.5mol% in saponification degree in dimethyl sulfoxide is subjected to wet spinning into fibers, which are, in turn, dried and then put to dry heat orientation to obtain the objective polyvinyl. alcohol fibers. In this case, in one of the processes involving the spinning dope to the drying, the fibers are imparted with 0.5-10wt.%, based on the oriented yarn, of a ≥8C aliphatic aldehyde such as nonanedial, followed by conducting the dry heat orientation by a factor of ≥14 in terms of the whole draw ratio and then carrying out an acid treatment with an aqueous solution of methylol containing phosphoric acid to make a crosslinking reaction, thus obtaining the objective polyvinyl alcohol fibers ≥160°C in the hot water temperature in the case of being in 80% strength retention and ≥13g/de in single fiber tenacity.;COPYRIGHT: (C)1996,JPO