Industrial Technology Research Institute

Jin-Chyueh Lin

Jen-Chang Yang

Lien-Tai Chen

Hsiao-Chuan Chang

Hung-Yi Hsiao

Ting-Hsiu Chen

A wholly aromatic polyamide fiber containing above about 600 ppm (about 0.2 mole percent) of sulfonate in the polymer main chain is provided. The sulfonate is represented by the general formulas (III) or (IV): ##STR1## where M is hydrogen, a metal cation, or a quaternary ammonium ion. The fiber exhibits excellent dyeability and can be cation-dyed without the use of a dye carrier.

Wholly aromatic polyamide fiber with improved dyeability

Shaped articles are obtained from a polymerization mixture of soluble wholly aromatic polyamides in a gel state.

Method for producing shaped articles of soluble wholly aromatic

Soluble wholly aromatic polyamide is obtained by low-temperature polycondensation in an amide solvent such as N-methyl-2-pyrrolidone. The reaction mixture is neutralized with an alkali and spun into fibers by wet spinning, coagulated in a salt-free aqueous solution of an organic solvent, preferably the polymerization solvent, and subsequently drawn in another aqueous solution of the same organic solvent, both solutions being substantially at ambient temperatures below 50.degree. C. but above freezing, More than 60% of the total fiber drawing is executed in this low-temperature draw stage.

Process for preparing fibers of soluble wholly aromatic polyamides

Wholly aromatic polyamides and their shaped articles containing at least 85 mole percent of repeat units of m-phenylene isophthalamide: ##STR1## and repeat units of selected aromatic diamines and diacid chlorides exhibit improved flame resistance while retaining good thermal stability.

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Kao-Hsiung Shiann, Taiwan

Jin-Chyueh Lin