| abstract |
A dope containing cellulose acylate as a main content of polymer is cast on a front surface of a moving belt in a method of producing a film from a solution. A drying apparatus is confronted to a back surface of said belt to evaporate a solvent in the gel-like film. Further, a condensers are confronted to a cast surface of said gel-like film to condense a solvent vapor for recovery. A wind speed above and near the gel-like film is from 0.01 m/s to 0.5 m/s, and the belt is transported downwards at the casting position PS. When d (mm) is a distance between the casting surface and each condenser, Tw (° C.) is a temperature of each condenser, and Ts (° C.) is a temperature of the casting dope, conditions are satisfied: Q=(Ts−Tw)/d and 5<Q<100. The obtained film is excellent in thickness uniformity and optical properties, and therefore adequate for the optical film. |