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-aramid dope of low degree of polymerizationexhibiting an optical anisotropy containing 4-10%by weight of a pares-aramid having an inherentviscosity of 1.0-2.5 dl/g and 2-10% by weight of analkali metal chloride or an alkaline earth metalchloride in a pedlar amide solvent;a para-aramid fiber obtained by spinning theabove-mentioned para-aramid dope of low degree ofpolymerization;a para-aramid pulp obtained by cutting theabove-mentioned para-aramid fiber into a short fiber,mechanically fibrillating the short fiber with a highshearing force and thereafter drying the fibrillatedshort fiber;a process for producing a para-aramid fiberwhich comprises adding 0.94-0.99 mole of a para-orientedaromatic dicarboxylic acid halide to 1.00 mole of apares-oriented aromatic diamine in a polar amide solventin which 2-10% by weight of an alkali metal chloride oran alkaline earth metal chloride is dissloved, carryingout a polymerization at a temperature of -20°C to 50°Cto form a para-aramid dope of low degree of polymerizationexhibiting an optical anisotropy and having apara-aramid concentration of 4-10% by weight, andspinning the dope; anda process for producing a para-aramid pulpwhich comprises cutting the above-mentioned para-aramidfiber into a short fiber, mechanically fibrillating theshort fiber with a high shearing force, and thereafterdrying the fibrillated short fiber.