| 摘要 |
<p>A process for producing an optical film which comprises a step in which a melt comprising a molten cellulose ester resin is extruded from a casting die with an extruder and a step in which the melt extruded from the casting die is pressed between a first rotating member and a second rotating member to form a film. It is characterized in that when the melt temperature as measured at the casting die outlet, the film temperature as measured at the point where the film first comes into contact with the first rotating member, the film temperature as measured at the point where the film is pressed between the first rotating member and the second rotating member, and the glass transition temperature of the film are expressed as T1, T2, T3, and Tg, respectively, then they satisfy the following relationships: (1) 30°C = T1-T2 = 60°C; (2) 0°C = T2-T3 = 20°C; and (3) Tg < T3.</p> |
