| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cellulose ester film used as a protective film for the liquid-crystal display element, i.e. the polarizing plate, and having a small double refractive index suitable for the protective film, in an effort of enlarging the angle of visibility of the liquid-crystal display apparatus (LCD) which operates in the IPS mode enabling clear displaying with a high contrast ratio over a wide range. <P>SOLUTION: A manufacturing method of a cellulose ester film based on the solution casting method comprises a first process of mixing a non-chlorine type organic solvent, a cellulose ester and a retardation-reducing additive together to form a dope, a second process of cooling the resultant mixture at -100 to -10°C, and a third process of treating the mixture after the cooling treatment at 0-120°C. <P>COPYRIGHT: (C)2007,JPO&INPIT |
