| 摘要 |
PURPOSE:To obtain a film excellent in strength, heat resistance, etc., by converting an optically anisotropic dope containing poly-p- phenyleneterephthalamide into optically isotropic one by contact with a water- containing gas before introducing it into a coagulation bath in the formation of a film from the optically anisotropic dope containing poly-p- phenyleneterephthalamide. CONSTITUTION:An optically anisotropic dope containing poly-p- phenyleneterephthalamide of an inherent viscosity etainh>=2.5 and sulfuric acid of a concentration >=95wt.% is extruded through an annular orifice 1 in the annular form. A gas having an absolute humidity >=1g of water/kg of dry air, a relative humidity <=99% and a temperature >=70 deg.C is simultaneously supplied through a gas supply pipe 3 and a gas supply opening 4 to expand the dope and to apply heat and water to the dope to convert is into optically isotropic one. This dope is introduced into a coagulation bath 8, coagulated and wound around a winding roll 9 to obtain a poly-p-phenyleneterephthalamide film. |
