| abstract |
A dope containing cellulose acylate as a main content of polymer is cast on a moving belt in a method of producing a film. At least first and second drying units are arranged in a moving direction of the belt and disposed near the gel-like film on the belt. A temperature difference between a supplied drying air and an exhausted air in the first drying unit is higher than in the second drying unit. Further, the exhausted air of the first drying unit, in order to use as the drying air of the second drying unit, is heated by a heat exchanger such that the content of solvent is decreased. A produced film is excelling in thickness uniformity, and adequate to used as an optical polymer film. Polarizing filter, protective film, optical functioning film and liquid crystal display in which the film is used are excellent in optical properties. |