Patent ID: 8158777

Claim:
A process for making a cellulose ester, said process comprising: (a) adding a binary component to a halide ionic liquid; (b) dissolving cellulose in said halide ionic liquid; and (c) esterifying at least a portion of the dissolved cellulose in a reaction medium comprising said halide ionic liquid, said binary component, and an acylating reagent comprising a C 1 to C 20 alkyl carboxylic anhydride or carboxylic acid halide, an aryl carboxylic anhydride or carboxylic acid halide, or combination thereof, thereby producing said cellulose ester, wherein the degree of polymerization (DP) of the dissolved cellulose subjected to esterification in step (c) is within 10 percent of the DP of said cellulose dissolved in step (b).