| 摘要 |
PROBLEM TO BE SOLVED: To provide a cellulose acetate with which sticking of stains on a metal support can be reduced when a film is prepared by continuous flow casting. SOLUTION: Even if the chemical equivalent ratio of calcium to total sulfuric acid is made to be <0.3 by reducing sulfate ester group remaining in cellulose ester so that the amount of sulfate ester group becomes in the range of 10-160 ppm, expressed in terms of sulfuric acid, based on the cellulose ester, the moist-heat resistance is secured. Further, when a film is prepared by continuous flow casting, sticking of stains on a metal support can be reduced by making the amount of calcium to 10 ppm or less. COPYRIGHT: (C)2009,JPO&INPIT
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