Cellulose solutions comprising tetraalkylammonium alkylphosphate and products produced therefrom

Abstract

This invention relates a cellulose solution comprising cellulose and at least one tetraalkylammonium alkylphosphate and processes to produce the cellulose solution. Another aspect of this invention relates to shaped articles prepared from a cellulose solution comprising cellulose and at least one tetraalkylammonium alkylphosphate. Another embodiment of this invention relates to compositions comprising derivatives of cellulose prepared from a cellulose solution comprising at least one tetraalkylammonium alkylphosphate. Another embodiment of this invention relates to compositions comprising regioselectively substituted cellulose esters prepared from a cellulose solution comprising cellulose and at least one tetraalkylammonium alkylphosphate. In another embodiment of the invention, the cellulose esters of the present invention are used as protective and compensation films for liquid crystalline displays.

That which is claimed is: 
     
         1 . A cellulose solution comprising cellulose and one or more ionic liquids of the formula: 
       
         
           
           
               
               
           
         
       
       wherein R1, R2, R3, and R4 are independently a C 1 -C 5  straight chain alkyl group or a C 1 -C 5  branched alkyl group, and R5 and R6 are independently a hydrido, a C 1 -C 5  straight chain alkyl group, or a C 1 -C 5  branched alkyl group. 
     
     
         2 . The cellulose solution according to  claim 1 , wherein said cellulose has a degree of polymerization of at least 10. 
     
     
         3 . The cellulose solution according to  claim 2 , wherein R1 is methyl or ethyl; wherein R2, R3, and R4 are independently methyl, ethyl, propyl, butyl, isobutyl, pentyl; wherein R1, R2, R3, and R4 are not identical; and wherein R5 and R6 are methyl, ethyl, propyl, or butyl. 
     
     
         4 . A cellulose solution comprising cellulose and one or more ionic liquids selected from the group consisting of tributylmethylammonium dimethylphosphate ([TBMA]DMP), tributylethylammonium diethylphosphate ([TBEA]DEP), tripropylmethylammonium dimethylphosphate ([TPMA]DMP), and tripropylethylammonium diethylphosphate ([TPEA]DEP). 
     
     
         5 . The cellulose solution according to  claim 4 , wherein said cellulose is present in said cellulose solution in an amount from about 1 wt % to about 40 wt % based on a total weight of the cellulose solution. 
     
     
         6 . The cellulose solution according to  claim 5 , wherein said cellulose has an α-cellulose content of at least 90%. 
     
     
         7 . The cellulose solution according to  claim 6 , wherein said cellulose has a degree of polymerization of at least 1000. 
     
     
         8 . The cellulose solution according to  claim 7 , further comprising a cosolvent. 
     
     
         9 . A cellulose solution comprising cellulose having an α-cellulose content of at least 90% dissolved in one or more ionic liquids of the formula: 
       
         
           
           
               
               
           
         
       
       wherein R1, R2, R3, and R4 are independently a C 1 -C 5  straight chain alkyl group or a C 1 -C 5  branched alkyl group, and R5 and R6 are independently a hydrido, a C 1 -C 5  straight chain alkyl group, or a C 1 -C 5  branched alkyl group. 
     
     
         10 . The cellulose solution according to  claim 9 , wherein said cellulose is present in said cellulose solution in an amount from about 1 wt % to about 40 wt % based on a total weight of the cellulose solution. 
     
     
         11 . The cellulose solution according to  claim 10 , further comprising one or more cosolvents. 
     
     
         12 . The cellulose solution according to  claim 11 , wherein the one or more cosolvents are present in an amount of from about 5 wt % to about 90 wt % based on a total weight of the one or more cosolvents and the one or more ionic liquids. 
     
     
         13 . The cellulose solution according to  claim 12 , wherein an α-cellulose content of said cellulose is at least 95%. 
     
     
         14 . The cellulose solution according to  claim 12 , wherein said one or more cosolvents is selected from the group consisting of aprotic solvents, protic solvents, acids, and ionic liquids other than tetraalkylammonium alkylphosphates. 
     
     
         15 . The cellulose solution according to  claim 12 , wherein said one or more cosolvents comprises an acid. 
     
     
         16 . The cellulose solution according to  claim 12 , wherein said cellulose solution is clear. 
     
     
         17 . The cellulose solution according to  claim 16 , wherein said cellulose has a degree of polymerization of at least 10. 
     
     
         18 . The cellulose solution according to  claim 16 , wherein said cellulose has a degree of polymerization of at least 250. 
     
     
         19 . The cellulose solution according to  claim 9 , wherein said cellulose is present in said cellulose solution in an amount from about 7 wt % to about 20 wt % based on a total weight of the cellulose solution. 
     
     
         20 . A cellulose solution comprising:
 (a) cellulose;   (b) one or more ionic liquids of the formula:   
       
         
           
           
               
               
           
         
          wherein R1, R2, R3, and R4 are independently a C 1 -C 5  straight chain alkyl group or a C 1 -C 5  branched alkyl group, and R5 and R6 are independently a hydrido, a C 1 -C 5  straight chain alkyl group, or a C 1 -C 5  branched alkyl group; and 
         (c) one or more cosolvents. 
       
     
     
         21 . The cellulose solution of  claim 20 , wherein the amount of said one or more cosolvents ranges from about 5 to about 90 wt % based on a total weight of the one or more cosolvents and the one or more ionic liquids. 
     
     
         22 . The cellulose solution according to  claim 21 , wherein said one or more cosolvents is at least one selected from the group consisting of aprotic solvents and protic solvents. 
     
     
         23 . The cellulose solution according to  claim 21 , wherein said one or more cosolvents comprises an aprotic solvent selected from the group consisting of hexamethylphosphoramide, N-methylpyrrolidone, nitromethane, dimethylformamide, dimethylacetamide, acetonitrile, sulfolane, and dimethyl sulfoxide. 
     
     
         24 . The cellulose solution according to  claim 21 , wherein said one or more cosolvents comprises a protic solvent selected from the group consisting of aliphatic carboxylic acids and amines. 
     
     
         25 . The cellulose solution of  claim 21 , wherein said one or more cosolvents comprises an aliphatic carboxylic acid selected from the group consisting of acetic acid, propionic acid, butyric acid, and isobutyric acid. 
     
     
         26 . The cellulose solution of  claim 21 , wherein said one or more cosolvents comprises an amine selected from the group consisting of diethyl amine, butyl amine, dibutyl amine, propyl amine, and dipropyl amine. 
     
     
         27 . The cellulose solution of  claim 21 , wherein said one or more cosolvents comprises at least one carboxylated ionic liquid or at least one halogenated ionic liquid. 
     
     
         28 . The cellulose solution of  claim 21 , wherein said one or more cosolvents comprises an acid which does not combine with cellulose in said cellulose solution. 
     
     
         29 . The cellulose solution of  claim 23 , wherein said one or more cosolvents comprises at least one salt corresponding to the structure: 
       
         
           
           
               
               
           
         
       
       wherein R1 and R3 are independently a C 1 -C 8  alkyl group, a C 2 -C 8  alkenyl group, or a C 1 -C 8  alkoxyalkyl group, and R2, R4, and R5 are independently a hydrido, a C 1 -C 8  alkyl group, or a C 2 -C 8  alkenyl group; and wherein k are chloride, C 1 -C 20  straight chain or branched carboxylate or substituted carboxylate, or alkylphosphates. 
     
     
         30 . Articles prepared from the cellulose solution of  claim 20 .