| 摘要 |
PROBLEM TO BE SOLVED: To obtain a film having a flat and smooth surface. SOLUTION: A dope is prepared from a TAC and a mixed solvent and an additive. The dope is flow-casted from a cast die 31 on a cast band 34. A cast film 69 is formed on the cast band 34. The cast film 69 is transferred accompanied with the movement of the cast band 34. A fast drying blowing air vent 73 is arranged at a position being 1,000 mm downstream from a labyrinth seal 50. Dry air 57 is hit at the cast film from a nozzle 73a of the blowing air vent 73, and the wind speed of the dry air 57 is controlled to 12 m/s. A thin film 69a is formed on a surface of the cast film 69, and after the thin film 69a being formed, the whole cast film 69 is dried. After the cast film 69 obtains a self-supporting property, it is peeled off from the cast band 34. After it is heated and stretched by a tenter type drier, it is dried in a drying room, to obtain a film. COPYRIGHT: (C)2007,JPO&INPIT |
