| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing stably and rapidly a cellulose acylate film that is substantially optically isotropic, moreover whose optical anisotropy is small in wavelength dispersion. SOLUTION: This method for producing the cellulose acylate film satisfies the formula (I) and (II), and comprises a first process to dissolve a cellulose acylate as a raw material roughly in a solvent and a second process to prepare a dope by accelerating dissolution of the solution, that is roughly dissolved in the first process, while supplying the solution. Formula (I): 0≤Re<SB>(630)</SB>≤10, and ¾Rth<SB>(630)</SB>¾≤25; Formula (II): ¾Re<SB>(400)</SB>-Re<SB>(700)</SB>¾≤10, and ¾Rth<SB>(400)</SB>-Rth<SB>(700)</SB>¾≤35, wherein, Re<SB>(λ)</SB>is a frontal retardation value (unit: nm) at a wavelengthλnm, Rth<SB>(λ)</SB>is a retardation value (unit: nm) in a film thickness direction at a wavelengthλnm. COPYRIGHT: (C)2006,JPO&NCIPI |
