| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical film, by which a film having a retardation Re in an in-plane direction and a retardation Rth in a thickness direction, both small and uniform, and having a uniform thickness can be efficiently manufactured.SOLUTION: The method for manufacturing an optical film includes: a molten resin film forming step of extruding a thermoplastic resin in a molten state and continuously molding a molten resin film 101; and a cooling step of continuously guiding the molten resin film 101 to a cast roll 130, conveying the molten resin film 101 along a conveyance passage on a peripheral surface of the cast roll 130 by rotation of the cast roll 130 so as to cool the molten resin film 101 to obtain a cured film, and releasing the obtained cured film from the cast roll 130. The cooling step includes reducing a pressure in a specific space and controlling a temperature of the cured film to Tg or lower upon releasing the cured film. |
