To provide a hydrolysate of metal alkoxide used for manufacturing an optical film which is used as a protective film for a polarizing plate etc. of a liquid crystal display device (LCD), to provide a method of preparing a solution of the hydrolysate, to provide an optical film which is obtained by using the hydrolysate of metal alkoxide, has excellent dimensional characteristics, has high film strength and has improved toughness , to provide a manufacturing method of the optical film and to provide a polarizing plate which is excellent in dimensional stability and moreover permits the improvement of the quality (dimensional stability) of an LCD by using the optical film.
In the preparation of a cellulose ester film as the optical film, a dope of the cellulose ester film is prepared by mixing an organic solvent, the hydrolysate of metal alkoxide and cellulose ester, wherein, when preparing the hydrolysate of the metal alkoxide, a dope main solvent which dissolves cellulose ester is added as a part of reaction solvent and, thereby, hydrolysis of metal alkoxide is performed.
Einosuke Kishimoto
Akira Watanabe