PURPOSE: To stably obtain the subject fiber having excellent spinning properties, etc., in low cost by subjecting to conjugate spinning a spinning solution composed of acrylic polymer solution copolymerized with specific component and a spinning solution composed of said polymer solution mixed with specific infrared light emitting substance.
CONSTITUTION: At first, a far-infrared light emitting substance (preferably highly purified zirconia) having ≥70% in average of far-infrared emitting fraction in a region of 6-14μm at 40°C is uniformly dispersed in a solvent and a solution of acrylic polymer in which ≥0.2mol% sulfonic acid group-containing monomer is copolymerized is added to said solvent to prepare raw solution of master polymer. Next, said raw solution and raw solution of acrylic polymer copolymerized of ≥0.2mol% sulfonic acid group-containing monomer are subjected to conjugate spinning through static mixer to afford the aimed fiber containing ≥0.5wt.% the above-mentioned far-infrared light emitting substance, copolymerized of ≥0.2mol% sulfonic acid-containing monomer and having ≥2.5g/d tensile strength and ≥1g/d knot strength.
TAMAOKI HIROSHI
TANAKA HIROYOSHI
