Regioselectively substituted cellulose esters produced in a halogenated ionic liquid process and products produced therefrom
AssigneeEastman Chemical Company
InventorsCharles Michael Buchanan, Norma Lindsey Buchanan, Michael Eugene Donelson, Maryna Grigoievna Gorbunova, Thauming Kuo, Bin Wang
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Abstract
This invention relates to novel compositions comprising regioselectively substituted cellulose esters. One aspect of the invention relates to processes for preparing regioselectively substituted cellulose esters from cellulose dissolved in ionic liquids. Another aspect of the invention relates to the utility of regioselectively substituted cellulose esters in applications such as protective and compensation films for liquid crystalline displays.
Claims26
A process of making a regioselectively substituted cellulose ester said process comprising:
- (a) introducing a reaction medium comprising cellulose, a halide ionic liquid and a binary component into an esterification zone;
- and
- (b) combining at least one acylating reagent with said reaction medium in said esterification zone to esterify at least a portion of said cellulose thereby producing said regioselectively substituted cellulose ester;
- wherein said acylating reagent is added at one time or in consecutive stages.
A process of making a regioselectively substituted cellulose ester said process comprising:
- (a) dissolving a cellulose in a halide ionic liquid to thereby form an initial cellulose solution;
- (b) contacting said initial cellulose solution with a binary component and an acylating reagent under conditions sufficient to provide an acylated cellulose solution comprising a cellulose ester;
- wherein said acylating reagent is added at one time or in consecutive stages;
- (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 at least a portion of said halide ionic liquid;
- (d) separating at least a portion of said precipitated cellulose ester from said halide ionic liquid to thereby provide a recovered cellulose ester and a separated halide ionic liquid;
- and
- (e) optionally, recycling at least a portion of said separated halide ionic liquid for use in dissolving additional cellulose
A film comprising at least one regioselectively substituted cellulose ester with a RDS ratio of C6>C3>C2.
A compensation film comprising at least one regioselectively substituted cellulose ester with a RDS ratio of C6>C3>C2;
- wherein said compensation film has an Rth range from about −400 to about +100 nm.
Dependencies are inferred from the claim text.