| 摘要 |
PURPOSE:To obtain the titled highly fibrillated yarn by a simple method, by extruding an optically anisotropic dope of para-orientated aromatic polyamide from a spinneret through a gas to a coagulating bath, releasing tension, impregnating the yarn with a blowing agent, drying and then expanding. CONSTITUTION:Para-orientated aromatic polyamide is dissolved in 97-101wt.% conc. sulfuric acid in >=14wt.% polymer concentration to give optically anisotropic dope, which is extruded from a spinneret to a gas, then to a coagulating solution, made into yarn and tension is released from the coagulated yarn in coagulation period and/or initial period of washing period wherein the amount of remaining sulfuric solvent is >=5wt.% based on dried yarn to give yarn having >=50wt.% water content. Then the yarn is impregnated with a solution of a blowing agent in a water-miscible solvent under release of tension to give >=0.5wt.% based on dried yarn weight of the blowing agent. The yarn is dried and heated to >=the decomposition temperature of the blowing agent to give the aimed yarn.
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