| 摘要 |
PROBLEM TO BE SOLVED: To suppress variation in a retardation Rth of a retardation film even when the film is impregnated with water and then dried or subjected to a high-temperature and high-humidity use environment, and to reduce display irregularity when the film is applied to a liquid crystal display device.SOLUTION: A retardation film 13 comprises a cellulose ester resin. When the retardation film is immersed in water, ΔRth1 (nm) defined by subtracting a retardation in a thickness direction of the film prior to the immersion in water from a retardation in the thickness direction after the immersion satisfies ΔRth1≥-14 nm. When the retardation film after immersed in water is dried at 23°C and 55% RH or subjected to an environment of 60°C and 90% RH, ΔRth2 (nm) representing a variation amount of the retardation in the thickness direction under the above conditions from the retardation prior to the immersion in water satisfies -4 nm≤ΔRth2≤4 nm.SELECTED DRAWING: Figure 1 |
