| 摘要 |
A method for producing an optical film is characterized in that a thermoplastic resin is melt-extruded into a film through an extrusion die (1), the melt-extruded thermoplastic resin layer (8) together with a supporting layer (9) is pressed between a cooling roll (2) which is made of a metal or a ceramic and a rubber roll (3), and after conveying the thermoplastic resin layer (8) together with the supporting layer (9) until the thermoplastic resin layer (8) is cooled down, the supporting layer (9) is separated to obtain a thermoplastic resin film (11). By such melt extrusion, there can be obtained various optical films used for liquid crystal displays or the like which films are free from optical surface defects such as die lines and gear marks and have uniform thicknesses and uniform optical characteristics. In particular, an optical film suitable as a raw material for retardation films can be obtained. |
