To obtain cellulose triacetate having a high stripping quality of a film from a base material in a casting method and excellent optical properties by using a low-purified pulp.
This cellulose triacetate having 58-62.5% average acetified degree is obtained by acetylating a low-purified pulp comprising 0.35-3.0 molar ratio of (mannose/xylose) in a neutral constituting sugar component, 90-97wt.% of α-cellulose content and 2-6mol% total content of the mannose and the xylose. Stripping quality of a film from a base material in a casting method can be improved by using cellulose triacetate containing 0.35-3.0 molar ratio of (mannose/xylose). For improving optical properties of the film, 400-500 pts.wt. of acetic acid to 100 pts.wt. of the pulp may be used or the cellulose triacetate may be treated with an oxidizer in an acetifying process.
NAKANO YUKIKO
HANIYU NAOTO
TANIGUCHI HIROKI
