METHOD FOR PRODUCING DENSE META-TYPE WHOLLY AROMATIC POLYAMIDE FIBER

摘要

PROBLEM TO BE SOLVED: To provide a method capable of producing a meta-type wholly aromatic polyamide fiber excellent in heat property and whiteness and not containing salts in a substantially industrial production level. SOLUTION: (1) A spinning dope composed of a meta-type wholly aromatic polyamide polymer solution dissolving a meta-type wholly aromatic polyamide containing a m-phenylene isophthalamide skeleton as a main component in an amide-based solvent and not substantially containing salts is discharged into a coagulating bath composed of an amide-based solvent and water and not substantially containing salts and kept to 20-70°C and the dope is coagulated as a porous linear body from a spinneret and (2) the coagulated fiber is immersed in a first regulation bath composed of an aqueous solution of an amide-based solvent and kept to 20-40°C and (3) the coagulated fiber is immersed into a second regulation bath composed of an aqueous solution of inorganic metal salt compound and kept to a second swelling temperature (T2to T2-30°C) and (4) the fiber is stretched in a plasticizing and stretching bath composed of an aqueous solution of amide-based solvent and (5) the stretched fiber is washed with water or an aqueous solution of amide-based solvent and (6) the fiber is heat-treated at 100-250°C and (7) the fiber is further heat-treated at 270-400°C to provide the dense meta-type-wholly aromatic polyamide fiber excellent in whiteness. COPYRIGHT: (C)2005,JPO&NCIPI