Regioselectively substituted cellulose esters produced in a halogenated ionic liquid process and products produced therefrom
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.
1. A cellulose ester comprising at least two different acyl groups, wherein at least one of said acyl groups comprises an aromatic compound, wherein said cellulose ester is regioselectively substituted with a RDS ratio of C6>C3>C2.
2. The cellulose ester of claim 1 , wherein said aromatic compound comprises a benzoate or a substituted benzoate.
3. The cellulose ester of claim 1 , wherein said aromatic compound comprises a benzoate.
4. The cellulose ester of claim 1 , wherein said cellulose ester has a degree of substitution from 1.6 to 2.9.
5. The cellulose ester of claim 1 , wherein at least one of said acyl groups comprises acetate or propionate.
6. The cellulose ester of claim 1 , wherein the ring RDS ratio of said cellulose ester for C6/C3 or C6/C2 is at least 1.05.
7. A film comprising said cellulose ester of claim 1 .
8. The film of claim 7 , wherein said film comprises a +C plate, a −C plate, a +A plate, or −A plate.
9. The film of claim 7 , wherein said film has an Rth in the range of −400 to +100 nm.
10. The film of claim 7 , wherein said film has an Rth in the range of −160 to +270 nm.
11. A compensation film comprising a regioselectively substituted cellulose ester comprising at least two different acyl groups, wherein at least one of said acyl groups comprises an aromatic compound, wherein the degree of substitution of said aromatic compound is greater at the C2 and C3 positions relative to the C6 position, wherein said film comprises a +C plate, a −C plate, a +A plate, or −A plate.
12. The film of claim 11 , wherein said aromatic compound comprises a benzoate or a substituted benzoate.
13. The film of claim 11 , wherein said aromatic compound comprises a benzoate.
14. The film of claim 11 , wherein said cellulose ester has a RDS ratio of C6>C3>C2.
15. The film of claim 11 , wherein said cellulose ester has a degree of substitution from 1.6 to 2.9.
16. The film of claim 11 , wherein at least one of said acyl groups comprises acetate or propionate.
17. The film of claim 11 , wherein said film has an Rth in the range of −400 to +100 nm.
18. The film of claim 11 , wherein said film has an Rth in the range of −160 to +270 nm.