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US 4,329,447 AGranted
Catalyst for and method of preparing cellulose esters
AssigneeEastman Kodak Company
InventorsRichard J. Brewer, Brice S. Wininger
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AssigneeEastman Kodak Company
InventorsRichard J. Brewer, Brice S. Wininger
Estimating the term…
Disclosed is a catalyst and a method of preparing lower fatty acid esters of cellulose which comprises esterifying at a temperature of between about 75.degree. C. and about 110.degree. C. a cellulose compound having esterifiable hydroxyl groups with an esterifying bath comprising an organic acid anhydride, a diluent, and a catalyst comprising (a) from about 0.3 to about 3.0% by weight, based on the weight of cellulose, of an acid selected from the group consisting of sulfuric acid, p-toluene sulfonic acid, methane sulfonic acid, methane disulfonic acid and m-benzene disulfonic acid, and (b) from about 0.05 to about 0.3% by weight, based on the weight of cellulose, of a dialkyl phosphite, the alkyl groups of which contain from 2 to 4 carbon atoms, the weight ratio of said bath to the cellulose being between about 5:1 and about 10:1.
A method of preparing lower fatty acid esters of cellulose which comprises esterifying at a temperature of between about 75.degree. C. and about 110.degree. C. a cellulose compound having esterifiable hydroxyl groups with an esterifying bath comprising an organic acid anhydride, a diluent, and a catalyst comprising (a) from about 0.3 to about 3.0% by weight, based on the weight of cellulose, of an acid selected from the group consisting of sulfuric acid, p-toluene sulfonic acid, methane sulfonic acid, methane disulfonic acid and m-benzene disulfonic acid, and (b) from about 0.05 to about 0.3% by weight, based on the weight of cellulose, of a dialkyl phosphite, the alkyl groups of which contain from 2 to 4 carbon atoms, the weight ratio of said bath to the cellulose being between about 5:1 and about 10:1.
A method of preparing lower fatty acid esters of cellulose which comprises esterifying at a temperature of between about 85.degree. C. and about 95.degree. C. a cellulose compound having esterifiable hydroxyl groups with an esterifying bath comprising an organic acid anhydride, a diluent, and a catalyst comprising (a) from about 0.5 to about 1.0 by weight, based on the weight of cellulose, of an acid selected from the group consisting of sulfuric acid, p-toluene sulfonic acid, methane sulfonic acid, methane disulfonic acid and m-benzene disulfonic acid, and (b) from about 0.10 to about 0.20 by weight, based on the weight of cellulose, of a dialkyl phosphite, the alkyl groups of which contain from 2 to 4 carbon atoms, the weight ratio of said bath to the cellulose being between about 5:1 and about 10:1.
Dependencies are inferred from the claim text.