PURPOSE: To produce a water-soluble polyester sheet material reutllizable by extracting the original components from an aqueous solution produced by dissolving the used sheet in hot water, effective for resource-saving and environmental pollution protection and suitable as a material for medical and hygienic goods, beddings, sports goods, etc.
CONSTITUTION: A water-soluble polyester copolymer is produced by polymerizing at least four kinds of acid components consisting of 50-80mol% (based on the total carboxylic acid component) of a mixture of terephthalic acid and/or its derivative and isophthalic acid and/or its derivative at a molar ratio of 30/70 to 70/30, 5-15mol% of a dicarboxylic acid containing sulfonic acid group and/or its derivative such as an alkali metal salt and 5-30mol% of an aliphatic dicarboxylic acid such as a cyclohexanedicarboxylic acid or a cyclopentanedicarboxylic acid and/or its derivative and a glycol component. A water-soluble polyester fiber produced from the copolymer is bonded and fixed by weaving, knitting or mechanical, chemical or thermal means and formed in the form of a nonwoven fabric or a mesh fabric to obtain a net- shaped water-soluble sheet material.
SASAKI HAJIME
NAKA KOJI
YAMAMURA AKIO
NAKAI HIROYUKI
