| 摘要 |
PURPOSE:To obtain an aromatic polyamide film whose mechanical properties are favorable, by a method wherein a filmy dope is solidified after being changed from optically anisotropic to optically isotropic and a wet film containing water more than a specific quantity to a polymer by washing is dried after the same has bee oriented specific times longer in a uniaxial direction. CONSTITUTION:After a dope containing polyamide constituted of aromatic unit of linear coordination whose logarithmic viscosity etainh is more than 2.5 and at least a kind of a solvent selected out of sulfuric acid whose concentration is more than 98wt%, chlorosulfuric acid and fluorosulfuric acid and having optical anisotropy in the vicinity of a normal temperature has been made into a filmy state, the same is solidified by making the same change once to optical isotropy. After the solvent has been removed from a solidified film through washing with water, the same is oriented uniaxially in a wet state containing water. Water content of the film is more than 50wt.pt. to a 100wt.pt. polymer; as wet orientation brings out mechanical strength after dryness effectively, the film is oriented 1.05-2.5 times longer. The oriented film is dried to remove an adhering washing liquid. |
