| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cellulose derivative film which is suitably used for an optical film, excellently exhibits retardation, is least liable to change in retardation due to moisture. <P>SOLUTION: The film contains a cellulose derivative satisfying following formulas (1)-(3). Formula (1): 2≤A+B≤3. Formula (2): 0.05≤A≤2.0. Formula (3): 0.05≤B≤2.95. (In the formulas, A is a degree of substitution of a group expressed by (Ar)<SB>3</SB>C- to the hydrogen atoms constituting the hydroxyl groups of the cellulose; Ar is a 6-20C aromatic group; B is a degree of substitution of a 2-6C alkanoyl group to the hydrogen atoms constituting the hydroxyl groups of the cellulose). <P>COPYRIGHT: (C)2007,JPO&INPIT |
