Polyvinyl alcohol fiber for binding a fibrous sheet and a process for the preparation thereof

摘要

A water-soluble polyvinyl alcohol fiber is obtained by subjecting to the conventional dry or wet spinning process, a solution prepared by adding to a polyvinyl alcohol aqueous solution, an adduct composed of a polyamide condensation product and 1-halogen-2,3-epoxy propane or ethylene glycol diglycidyl ether in the range from 5 to 50 percent by weight based upon the polyvinyl alcohol-after the solution's pH has been adjusted to 2 to 7. The resulting fiber, which has not been subjected to any heat treatment at a temperature above 120 DEG C. is blended with a fibrous material to make a fibrous sheet such as paper or non-woven fabric. By virtue of a subsequent heat-treatment, said polyvinyl alcohol fiber becomes boiling water-resistant; as a result, the wet strength of the fibrous sheet is significantly increased.