| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a cellulose film having a high retardation value in its thickness direction. <P>SOLUTION: When the retardation value in the thickness direction of the cellulose film is set to 50-500 nm, the density of the film at 25°C is set to 1.290 or above. In the manufacture of the cellulose film by a solvent casting method using a non-chlorine solvent as a main solvent, a process for cooling a mixture of cellulose acylate with a degree of acyl substitution of 2.0-2.8 and an organic solvent to -100 to -10°C is introduced to obtain the cellulose film having a high retardation value. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
