| 摘要 |
PROBLEM TO BE SOLVED: To regulate the relation between perpendicular retardation (Rth) and in-plane retardation (Re) of a cellulose ester film. SOLUTION: The cellulose ester film is produced by stretching it 0.1 to 20% in the direction perpendicular to machine direction, in a drying process of a solvent cast method; provided that the stretch substantially does not take place in the machine direction when film temperature hits or exceeds a glass transition temperature of the cellulose ester, and that the amount of residual solvent is kept 5 to 3 wt.% when the film temperature is lower than the glass transition temperature of the cellulose ester. COPYRIGHT: (C)2008,JPO&INPIT |
