| 摘要 |
Provided is a method for manufacturing an optical film, which manufactures a transparent optical film controlled to have a little changes in retardation even after a humidity and heat durability test. A second tender (20) includes a preheat area (45), a first stretch area (46), a second stretch layer (47), and a cooling area (48) in order from the upstream side of the returning direction (Z1). The first stretch area (46) maintains the temperature of the film in a range from (Tg+10°C) or more to (Tg+50°C) or less. The first stretch area (46) stretches the film (12) in the width direction to widen the width to one and a half times or more. The second stretch area (47) stretches the film (12) in the width direction to a stretch angle (theta2) smaller than the stretch angle (theta1) of the first stretch area (46). |
