| 摘要 |
PROBLEM TO BE SOLVED: To enable a cellulose ester to be dissolved in a variety of organic solvents. SOLUTION: In this preparation method, a mixed fatty acid ester of cellulose of which hydroxy groups are substituted by acetyl groups and acyl groups having 3 or more carbon atoms and of which the degree of acetyl group substitution (DSace) and the degree of substitution (DSacy) by the acyl group having 3 or more carbon atoms satisfies the following formulae; (1) 2.0<DSace≤2.95, (2) 0.05<DSacy≤0,8 and (3) 2.6<DSace+DSacy≤3.0. The mixed fatty acid ester of cellulose is dissolved in a solvent in such a way that these two are mixed in advance, then they are cooled to a freezing temperature or below and thereafter they are heated. COPYRIGHT: (C)2003,JPO
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