Solubility of cellulose in ionic liquids with addition of amino bases

1. A solution comprising cellulose, an ionic liquid comprising anions and cations as solvent and 6-30% by weight of a nitrogen-comprising base, based on the total weight of the solution, wherein the ionic liquid comprises at least one cation of formula (IVe)

and oligomers comprising these structures, where

the radical R is hydrogen, a carbon-comprising organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic radical which has from 1 to 20 carbon atoms and is unsubstituted or interrupted by from 1 to 5 heteroatoms or functional groups or substituted; and

the radicals R 1 to R 4 are each, independently of one another, hydrogen, a sulfo group or a carbon-comprising organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic radical which has from 1 to 20 carbon atoms and is unsubstituted or interrupted by from 1 to 5 heteroatoms or functional groups or substituted, with the radicals R 1 to R 4 which are bound to a carbon atom (and not to a heteroatom) in the abovementioned formulae (IV) also being able to be halogen or a functional group; or

two adjacent radicals from the group consisting of R 1 to R 4 can together also be a divalent, carbon-comprising organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic radical which has from 1 to 30 carbon atoms and is unsubstituted or interrupted by from 1 to 5 heteroatoms or functional groups or substituted,

wherein the nitrogen-comprising base is a compound whose nitrogen atom or atoms is/are primary, secondary or tertiary and which is derived from the quaternary compounds of formula (IVe), with the radical R forming the quaternary nitrogen of the quaternary compounds not being present and R 1 -R 4 , independently of one another, are as defined above.

2. The solution according to claim 1 , comprising more than 1% by weight of cellulose, based on the total weight of the solution.

3. The solution according to claim 1 , wherein the ionic liquid comprising anions and cations comprises at least one anion selected from the group consisting of

the group of halides and halogen compounds of the formulae:

F − ,Cl − ,Br − ,I − ,BF 4 − ,PF 6 − ,AlCl 4 − ,Al 2 Cl 7 − ,Al 3 Cl 10 ,AlBr 4 − ,FeCl 4 − ,BCl 4 − ,SbF 6 − , AsF 6 , − ZnCl 3 − ,SnCl 3 − ,CuCl 2 − ,CF 3 SO 3 − ,(CF 3 SO 3 ) 2 N − ,CF 3 CO 2 − ,CCl 3 CO 2 − ,CN − , SCN − ,OCN −

the group of sulfates, sulfites and sulfonates of the general formulae:

SO 4 2− ,HSO 4 − ,SO 3 2− ,HSO 3 − ,R a SO 3 −

the group of phosphates of the general formulae

PO 4 3− ,HPO 4 2− ,H 2 PO 4 − ,R a PO 4 2− ,HR a PO 4 − ,R a R b PO 4 −

the group of phosphonates and phosphinates of the general formulae:

R a HPO 3 − ,R a R b PO 2 − ,R a R b PO 3 −

the group of phosphites of the general formulae:

PO 3 3− ,HPO 3 2− ,H 2 PO 3 − ,R a PO 3 2− ,R a HPO 3 − ,R a R b PO 3 −

the group of phosphonites and phosphinites of the general formulae:

R a R b PO 2 − ,R a HPO 2 − ,R a R b PO − ,R a HPO −

the group of carboxylic acids of the general formula:

R a COO −

the group of borates of the general formulae:

BO 3 3− ,HBO 3 2− ,H 2 BO 3 − ,R a R b BO 3 − ,R a HBO 3 − ,R a BO 3 2− , B(OR a )(OR b )(OR c )(OR d ) − ,B(HSO 4 ) − ,B(R a SO4) −

the group of boronates of the general formulae:

R a BO 2 2− ,R a R b BO −

the group of carbonates and carbonic esters of the general formulae:

HCO 3 − ,CO 3 2− ,R a CO 3 −

the group of silicates and silicic esters of the general formulae:

SiO 4 4− ,HSiO 4 3− ,H 2 SiO 4 2− ,H 3 SiO 4 − ,R a SiO 4 3− ,R a R b SiO 4 2− ,R a R b R c SiO 4 − , HR a SiO 4 2− ,H 2 R a SiO 4 − ,HR a R b SiO 4 −

the group of alkyl silane and aryl silane salts of the general formulae:

R a SiO 3 3− ,R a R b SiO 2 2− ,R a R b R c SiO − ,R a R b R c SiO 3 − ,R a R b R c SiO 2 − ,R a R b SiO 3 2−

the group of carboximides, bis(sulfonyl)imides and sulfonylimides of the general formulae:

the group of methides of the general formula:

the group of alkoxides and aryloxides of the general formula

R a O − ;

the group of halometalates of the general formula

[M g Hal r ] s− ,

where M is a metal and Hal is fluorine, chlorine, bromine or iodine, q and r are positive integers and indicate the stoichiometry of the complex and s is a positive integer and indicates the charge on the complex;

the group of sulfides, hydrogen sulfides, polysulfides, hydrogen polysulfides and thiolates of the general formulae:

S 2− ,HS − ,[S v ] 2− ,[HS v ] − ,[R a S] − ,

where v is a positive integer from 2 to 10; and

the group of complex metal ions such as Fe(CN) 6 3− , Fe(CN) 6 4− , MnO 4 Fe(CO) 4 − , where

R a , R b , R c and R d are each, independently of one another, hydrogen, C 1 -C 18 -alkyl, C 2 -C 18 -alkyl which is optionally interrupted by one or more nonadjacent oxygen and/or sulfur atoms and/or one or more substituted or unsubstituted imino groups, C 6 -C 14 -aryl, C 5 -C 12 -cycloalkyl or a five- or six-membered, oxygen-, nitrogen- and/or sulfur-comprising heterocycle, where two of them may together form an unsaturated, saturated or aromatic ring which is optionally interrupted by one or more oxygen and/or sulfur atoms and/or one or more unsubstituted or substituted imino groups, where the radicals mentioned may each be additionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or heterocycles.

4. The solution according to claim 1 which has a temperature of not more than 180° C.

5. The solution according to claim 1 , wherein the proportion of the nitrogen-comprising base is 6-20% by weight, based on the total weight of the solution.

6. A process for preparing a solution according to claim 1 , comprising:

adding cellulose to a solution comprising said ionic liquid comprising anions and cations as solvent and said nitrogen-comprising base, and

mixing the solution until the cellulose is completely dissolved.

7. A method for the physical or chemical treatment of cellulose comprising dissolving cellulose in a solution comprising an ionic liquid as defined in claim 1 .