| 摘要 |
PURPOSE:To manufacture a para-oriented aromatic polyamide film having excellent mechanical strength, heat resistance, and transparency, by extruding an optically isotropic dope of the p-oriented aromatic polyamide through a die slit while applying a shearing force perpendicular to the flow direction of the dope. CONSTITUTION:A p-oriented aromatic polyamide is dissolved in, e.g. >=98 wt.% concentrated sulfuric acid to give a dope not exceeding the critical concentration and is optically isotropic without shearing stress. The dope is extruded through a slit of a molding die while being applied with a shear stress perpendicular to the flow of the dope. The applied stress is pref. the one which causes a shear rate of >=0.01 times that of the flow of the dope. The aromatic polyamide is pref. a copolyamide composed of >=80 mol.% of poly-p-benzamide, poly-p-phenylene terephthalamide, etc., and other p-oriented polyamide unit. |
