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 film comprising at least one regioselectively substituted cellulose ester with a RDS ratio of C 6 >C 3 >C 2 , wherein said regioselectively substituted cellulose ester is prepared from cellulose having an α-cellulose content of at least 95 percent by weight.
2. The film according to claim 1 wherein the ring RDS ratio of the regioselectively substituted cellulose ester for C 6 /C 3 or C 6 /C 2 is at least 1.05.
3. The film according to claim 1 wherein the product of the ring RDS ratio of the regioselectively substituted cellulose ester for C 6 /C 3 or C 6 /C 2 times the total DS is at least 2.9.
4. The film according to claim 1 wherein said regioselectively substituted cellulose ester has a ring RDS ratio for C 6 /C 3 or C 6 /C 2 is at least 1.05, and the product of the ring RDS ratio for C 6 /C 3 or C 6 /C 2 times the total DS is at least 2.9.
5. The film according to claim 1 wherein said regioselectively substituted cellulose ester has a carbonyl RDS ratio of at least one acyl substituent for C 6 /C 3 or C 6 /C 2 of at least 1.3.
6. The film according to claim 1 wherein the product of the carbonyl RDS ratio of at least one acyl substituent for C 6 /C 3 or C 6 /C 2 times the DS of the acyl substituent for said regioselectively substituted cellulose ester is at least 2.3.
7. The film according to claim 1 wherein the product of the carbonyl RDS ratio for C 6 /C 3 or C 6 /C 2 times the DS of the acyl substituent for said regioselectively substituted cellulose ester is at least 2.5.
8. The film according to claim 1 wherein the carbonyl RDS ratio of at least one acyl substituent for C 6 /C 3 or C 6 /C 2 for said regioselectively substituted cellulose ester is at least 1.3 and the product of the carbonyl RDS ratio for C 6 /C 3 or C 6 /C 2 times the acyl DS for said regioselectively substituted cellulose ester is at least 2.3.
9. A film according to claim 1 wherein said film is photographic film, protective film, or compensation film.