| 摘要 |
PURPOSE:To mold a molded material such as a high-performance polyimide fiber or film whose heat resistance and dynamic characteristics are high, by making use of a specific organic acid bath as a solidification bath. CONSTITUTION:At the time of manufacturing a molded material such as a fiber or a film by applying wet molding to a solution of polyamide acid prepared by applying solution polymerization to aromatic diamine and aromatic tetracarboxylic acid anhydride, a solution bath composed of acetic acid or acetic anhydride or mixture of them is used as a solidification bath. In this instance, when mixed series obtained by including an amide solvent and/or the acetic acid such as third class amine and/or the acetic anhydride and a nonreactive amine solvent with the acetic acid and acetic anhydride is used as the solidification bath at need, solidification power can be made favorable and control of a solidification speed can be performed. Solidification is completed while chemical cycloreaction is accelerated by a method wherein spinning, for example, is performed by making use of the acetic acid, whose solidification power is favorable, as the first bath, to begin with, and successively the acetic anhydride (or the mixed series of the acetic anhydride and acetic acid) is used for the bath on and after the second bath. Then orientation properties of a spun thread which is under a gelatinous state can be improved by stretching the same. |
