| 摘要 |
PURPOSE:To obtain a film excellent in surface properties and mechanical properties in high productivity by adopting specified conditions for humidification and heating in a process for obtaining a film by converting an optically anisotropic dope of a polymeric liquid crystal into an isotropic one by humidifying and heating it by a specified process and coagulating it. CONSTITUTION:A process for obtaining a film comprising casting an optically anisotropic dope of a polymeric liquid crystal (e.g. a sulfuric acid solution of poly-p-phenyleneterephthalamide) from a die on a supporting surface while it is kept optically anisotropic, converting the dope into optically isotropic one by humidifying and heating it and coagulating it, wherein said humidification and heating step is subdivided into at least two steps, and gases of different humidites and temperatures (e.g. air at a relative humidity of about 5% and a temperature of about 110 deg.C, air at a relative humidity of about 20% and a temperature of about 120 deg.C and air at a relative humidity of about 40% and a temperature of about 115 deg.C) are fed to the respective subdivided steps. |
