| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical film which is excellent in expression of retardation in a front direction and in a film thickness direction and has little fluctuation in the retardation values caused by environmental change such as humidity, to provide a liquid crystal display whose viewing angle characteristics are hardly affected even by environmental changes, and to provide a polarizing plate to be used for the display. <P>SOLUTION: A stretched film comprises a polymer component substantially composed of a cellulose acylate which is fatty acid ester of cellulose obtained by replacing a hydroxy group of a cellulose with at least either one of an acetyl group or a ≥3C acyl group. In the optical cellulose acylate film, (i) a degree of substitution A of an acetyl group and a degree of substitution B of a ≥3C acyl group satisfy formula (I) 2.0≤A+B≤3.0, and (ii) the film is obtained by being kept at a glass transition temperature (Tg) or higher for one minute or more after going through the process of stretching and relieving the stress after the maximum drawing rate. The polarizing plate using this film for an optical compensation sheet and the liquid crystal display equipped with this polarizing plate are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
