POLYAMIDE FOR FIBER, FIBER USING THE SAME AND PRODUCTION COLORED FIBER

摘要

PROBLEM TO BE SOLVED: To obtain a polyamide for fiber which is high in hollow ratio and excellent in dyeability when a cationic dye is used. SOLUTION: This polyamide is a polyamide containing a sulfonic acid group and comprising hexamethylene azipamide units, wherein 1) the terminal amino group is >=30 meq/kg and <=50 meq/kg, 2) the sulfonic acid group is >=50 meq/kg, and 3) (ηr) in sulfuric acid of 98 wt.% at 25 deg.C is >=3.0.