CELLULOSE ESTER AND PROCESS FOR PRODUCING THE SAME

摘要

A cellulose derivative that even in the use as the base material film of a viewing angle enlarging film with a discotic liquid crystal layer, would inhibit any occurrence of crater defects in the discotic liquid crystal layer. The cellulose derivative is obtained from a pulp of 20 ppm or less calcium content. The pulp may be derived from wood. The calcium content of the pulp may be in the range of about 0.01 to 15 ppm. The cellulose derivative may consist of a cellulose ester containing at least an acetyl. The calcium content of the cellulose derivative may be 120 ppm or less. This cellulose derivative is suitable for use as the base material film of a viewing angle enlarging film with a discotic liquid crystal layer.