Cellulose esters and their production in carboxylated ionic liquids
AssigneeEastman Chemical Company
InventorsCharles Michael Buchanan, Norma Lindsey Buchanan, Robert Thomas Hembre, Juanelle Little Lambert
Life of this patent
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Abstract
Ionic liquids and cellulose ester compositions and processes and apparatus for producing ionic liquids and cellulose esters. Cellulose esters can be produced by dissolving cellulose in carboxylated ionic liquids and thereafter contacting the cellulose solution with at least one acylating reagent. Cellulose esters produced via the present invention can comprise ester groups that originate from the carboxylated ionic liquid and/or the acylating reagent.
Claims85
A process for making cellulose esters, said process comprising:
- (a) dissolving cellulose in a carboxylated ionic liquid to thereby form a cellulose solution;
- (b) contacting said cellulose solution with an acylating reagent optionally in the presence of a catalyst to thereby provide an acylated cellulose solution comprising a cellulose ester, wherein said cellulose ester comprises at least one acyl group originating from said carboxylated ionic liquid;
- (c) contacting said acylated cellulose solution with a non-solvent to cause at least a portion of said cellulose ester to precipitate and thereby provide a slurry comprising precipitated cellulose ester and said carboxylated ionic liquid;
- (d) separating at least a portion of said precipitated cellulose ester from said carboxylated ionic liquid to thereby provide a recovered cellulose ester and a separated carboxylated ionic liquid;
- and
- (e) optionally recycling at least a portion of said separated carboxylated ionic liquid for use in dissolving additional cellulose.
A process for making cellulose esters, said process comprising:
- (a) combining cellulose, a carboxylated ionic liquid, a Lewis acid catalyst and an acylating reagent to thereby form a reaction medium;
- and
- (b) esterifying at least a portion of said cellulose in said reaction medium under reaction conditions sufficient to produce a cellulose ester having a degree of substitution of at least 2, wherein said acylating reagent is present in said reaction medium in an amount less than 4 molar equivalents per anhydroglucose unit,
- wherein said cellulose ester comprises a plurality of pendant acyl groups,
- wherein at least a portion of said pendant acyl groups originate from said carboxylated ionic liquid.
A process for making cellulose esters, said process comprising:
- (a) combining cellulose, a carboxylated ionic liquid, a Lewis acid catalyst and an acylating reagent to thereby form a reaction medium;
- and
- (b) esterifying at least a portion of said cellulose in said reaction medium to thereby produce a mixed cellulose ester, wherein said mixed cellulose ester comprises first and second pendant acyl groups that are different from one another, wherein said first pendant acyl group originates from said ionic liquid and said second pendant acyl group originates from said acylating reagent,
- wherein the anion of said carboxylated ionic liquid is selected from the group consisting of acetate anions, propionate anions, butyrate anions, and mixtures thereof,
- wherein said first pendant acyl groups are selected from the group consisting of an acetyl group, a propionyl group, a butyryl group, and mixtures thereof.
Dependencies are inferred from the claim text.