| 摘要 |
PROBLEM TO BE SOLVED: To obtain a dry-touch, highly water-absorptive fiber having a high water absorptivity of 30 to 50% and extremely low in deterioration in strength, and also to provide a method which can produce the above highly water- absorptive fiber in a very short time in high productivity. SOLUTION: This highly water-absorptive fiber, based on acrylic fiber, containing a tetrazine ring crosslinked bond at 1.0 to 16.0 mol% and carboxylic group at 2.0 to 5.0 mmol%, and having a water absorptivity of 30 to 50% and strength of 0.8 cN/dtex or more, is obtained by crosslinking the acrylic fiber containing acrylonitrile at 92 wt.% or more, spun/stretched and relaxation- treated under heating at a saturation steam pressure of 150 kPa or more, with an aqueous solution containing 8 to 80 wt.% of hydrazine at 125 to 140 deg.C for 20 to 40 minutes, and hydrolyzing the crosslinked product with an aqueous solution of an alkali metal hydroxide at 90 deg.C or higher for 10 to 40 minutes, or further treating the hydrolyzate for neutralization with an aqueous solution of pH 4 or less at 90 deg.C or higher. |
