METHOD FOR PRODUCING OPTICAL FILM

摘要

Provided is a method for producing an optical film by which the width of an optical film can be easily changed. An optical film production device is prepared and an optical film is produced. A dope is casted on a casting surface of a cast film support body, and a cast film is formed on the casting surface. The cast film is dried and solidified on the casting surface to add a self supporting property to the cast film. The cast film added with the self supporting property is separated from the casting surface to obtain a web. The web is transferred by a transfer roll group. The transfer roll group includes a transfer roll provided with slip suppression structures capable of adjusting the position in the roll thrust direction, on the peripheral surface of the transfer roll to be separated in the roll thrust direction. When the width of the web of a previously produced optical film is different from the width of the web of a currently produced optical film, the positions of the structures in the roll thrust direction are adjusted in accordance with the width of the web of the currently produced optical film.