To obtain a film suited for a high definition liquid display element and reduced in abnormal light emission without detriment to the polarized state by filtering a dope composition prepared by dissolving a cellulose ester through filter paper having a specified particle retention diameter and molding the filtered dope composition into a film.
The dope composition is obtained by compounding 10-50 wt.% cellulose ester having a degree of acetylation of 54-62% with a matting agent, an ultraviolet absorber having an excellent ability to absorb ultraviolet rays at a wavelength of 370 nm or below and a poor ability to absorb visible rays at a wavelength of 400 nm or above, 1-10 wt.%, based on the cellulose ester, plasticizer having a freezing point of 20°C or below, and 70-95 wt.% solvent. This composition is filtered through filter paper made from cotton linter pulp and/or wood pulp and having a retention particle diameter of 8 μm or below under conditions including a flow rate of the composition of 150 l/m2.hr or below and cast onto a support to obtain a film having a thickness of 10-500 μm, particularly, 20-100 μm.
TAKADA MASATO
MICHIHASHI ISAMU
TACHIBANA NORIKI
NAGAYASU KOICHI
