| 摘要 |
<p>This invention provides a process for producing a cellulose ester film suitable as a protective film and a phase difference film in a polarizing plate in a liquid crystal display device. In the production process, regarding foreign materials attributable to the addition of fine particles contained in a cellulose ester resin solution (dope), in a dope dissolution mixing step, the occurrence of foreign materials is suppressed. According to the above constitution, the production process can realize a reduction in the burden on a filter in a subsequent filtration step, freedom from foreign materials, and excellent productivity. In the production process of a cellulose ester film, fine particles are added in the step of dissolving a cellulose ester resin in a main solvent at a temperature at or below the boiling point of the main solvent under the atmospheric pressure, and, after the addition, mixing is carried out at a temperature at or above the boiling point of the main solvent. Preferably, the mixing is carried out in a temperature range of the boiling temperature of the main solvent to a temperature of (boiling point of the main solvent + 50ºC) fornot less than 60 min and not more than 300 min.</p> |
