Para-aramide dope of low degree of polymerization, para-aramide fiber and para-aramide pulp produced therefrom and processes for producing the same.

摘要

A para-aramide dope of low degree of polymerisation exhibiting an optical anisotropy containing 4-10% by weight of a para-aramide having an intrinsic viscosity of 1.0-2.5 dl/g and 2-10% by weight of an alkali metal chloride or an alkaline earth metal chloride in a polar amide solvent; a para-aramide fiber obtained by spinning the above-mentioned para-aramide dope of low degree of polymerization; a para-aramide pulp obtained by cutting the above-mentioned para-aramide fiber into a short fiber, mechanically fibrillating the short fiber with a high shearing force and thereafter drying the fibrillated short fiber; a process for producing a para-aramide fiber which comprises adding 0.94-0.99 mole of a para-oriented aromatic dicarboxylic acid halide per 1.00 mole of a para-oriented aromatic diamine in a polar amide solvent in which 2-10% by weight of an alkali metal chloride or an alkaline earth metal chloride is dissloved, carrying out a polymerization at a temperature of -20 DEG C to 50 DEG C to form a para-aramide dope of low degree of polymerization exhibiting an optical anisotropy and having a para-aramide concentration of 4-10% by weight, and spinning the dope; and a process for producing a para-aramide pulp which comprises cutting the above-mentioned para-aramide fiber into a short fiber, mechanically fibrillating the short fiber with a high shearing force, and thereafter drying the fibrillated short fiber.