Production of cellulose esters in the presence of a cosolvent
AssigneeEastman Chemical Company
InventorsCharles Michael Buchanan, Norma Lindsey Buchanan
Life of this patent
Estimating the term…
Abstract
Ionic liquids and cellulose ester compositions and processes for producing ionic liquids and cellulose esters. Cellulose esters can be produced by subjecting a cellulose-ionic liquid solution comprising cellulose, one or more ionic liquids, and one or more co-solvents to esterification to thereby produce an esterified medium comprising a cellulose ester. The co-solvents employed in the present invention can be either miscible or immiscible with the cellulose-ionic liquid solution but can be readily dispersed or soluble in the esterified medium.
Claims52
A process for producing a cellulose ester, said process comprising:
- (a) adding cellulose and a co-solvent to an ionic liquid having a melting point at a temperature of less than 100° C. to thereby form a cellulose solution comprising dissolved cellulose;
- and
- (b) esterifying at least a portion of said dissolved cellulose in a reaction medium comprising said ionic liquid, said co-solvent, and an acylating reagent comprising a C1 to C20 alkyl or aryl carboxylic anhydride, a carboxylic acid halide, an acetoacetic acid ester, or combinations thereof, to thereby produce an esterified solution, wherein said esterified solution comprises a cellulose ester and at least a portion of said co-solvent,
- wherein the degree of polymerization (DP) of the dissolved cellulose subjected to esterification in step (b) is within 10 percent of the DP of said cellulose dissolved in step (a).
A process for producing a cellulose ester, said process comprising:
- (a) adding cellulose and a co-solvent to an ionic liquid to thereby form a cellulose solution comprising dissolved cellulose, wherein the co-solvent comprises acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, hexanoic acid, 2-ethylhexanoic acid, nonanoic acid, lauric acid, palmitic acid, stearic acid, benzoic acid, a substituted benzoic acid, phthalic acid, isophthalic acid, methyl acetate, ethyl acetate, isopropyl acetate, methyl propionate, methyl butyrate, acetone, methyl ethyl ketone, chloroform, methylene chloride, an alkyl imidazolium hexafluorophosphate, an alkyl imidazolium triflimide, or combinations thereof;
- and
- (b) esterifying at least a portion of said dissolved cellulose in a reaction medium comprising said ionic liquid, said co-solvent, and an acylating reagent to thereby produce an esterified solution, wherein said esterified solution comprises a cellulose ester and at least a portion of said co-solvent,
- wherein the degree of polymerization (DP) of the dissolved cellulose subjected to esterification in step (b) is within 10 percent of the DP of said cellulose dissolved in step (a).
A process for producing a cellulose ester, said process comprising:
- (a) adding cellulose and a co-solvent to an ionic liquid to thereby form a cellulose solution comprising dissolved cellulose;
- and
- (b) esterifying at least a portion of said dissolved cellulose in a reaction medium comprising said ionic liquid, said co-solvent, and an acylating reagent to thereby produce an esterified solution, wherein said esterified solution comprises a cellulose ester and at least a portion of said co-solvent,
- wherein the degree of polymerization (DP) of the dissolved cellulose subjected to esterification in step (b) is within 10 percent of the DP of said cellulose dissolved in step (a) and the DP of the cellulose ester is less than 70 percent of the DP of the dissolved cellulose subjected to esterification in step (b).
Dependencies are inferred from the claim text.