PARA-ARAMID DOPE OF LOW DEGREE OF POLYMERIZATION, PARA-ARAMID FIBER AND PARA-ARAMID PULP PRODUCED THEREFROM AND PROCESSES FOR PRODUCING THE SAME

摘要

A para-aramide dope of low degree of polymerization exhibiting an optical anisotropy containing 410% 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 to 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.degree.C to 50.degree.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.