Cellulose ester having improved stability to wet heat
AssigneeDaicel Chemical Industries, Ltd.
InventorsToru Ozaki, Toru Shibata, Shu Shimamoto
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Abstract
The present invention provides a cellulose ester in which heat resistance under wet condition is compatible with both releasability and spinnability even when the amount of the residual solvent is small in a casting process. The cellulose ester fulfills the following formula: 0.5<(B)/(A)<1.5 wherein (A) and (B) represent the total amount (in terms of molar amount) of residual sulfuric acid in 1 gram of the cellulose ester and the total amount (in terms of molar amount) of calcium contained in 1 gram of the cellulose ester, respectively.
Claims13
A cellulose ester fulfilling the following formula:
- 0.5<(B)/(A)<1.2
- wherein (A) is the total amount (in terms of molar amount) of residual sulfuric acid in 1 gram of said cellulose ester, and (B) is the total amount (in terms of molar amount) of calcium contained in 1 gram of said cellulose ester, and the cellulose ester is (i) a cellulose acetate having an average degree of acetylation from 58 to 62.5%, or (ii) a mixed fatty acid ester of cellulose.
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Dependencies are inferred from the claim text.