| abstract |
An object of the present invention is to provide a method for producing an optical film containing soluble polyfluorene imide as a main component. The method is easy to reuse as a recycling waste material, and can reduce the phenomenon of indentation or retardation caused by stretching. Phase difference is uneven.nn n n The manufacturing method of the optical film of the present invention is a manufacturing method of an optical film containing a soluble, transparent polyimide resin, which is characterized by having a step of casting a dopant on a support to form a casting film, and forming the casting film from The step of peeling the support and the step of stretching the cast film that has been peeled off. When the elongation temperature in the elongation step is Tg (° C), the glass transition temperature of the polyimide resin is (Tg-250). ℃) ~ (Tg-100 ℃), the change of film temperature from the beginning to the end of the extension is within 70 ℃, and the extension temperature is more than 50 ℃ above the boiling point Tb (℃) of the main solvent. |