Ionic liquid and method for dissolving cellulose using the same

Patent metadata

Field	Value
Publication number	US-10875973-B2
Application number	US-202016796170-A
Country	US
Kind code	B2
Filing date	Feb 20, 2020
Priority date	Mar 27, 2017
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

The present invention also provides an ionic liquid composition containing an ionic liquid; and water. The ionic liquid is represented by the above chemical formula (I). A molar ratio of [(CH3)3N(CH2)2OH]+ to [NH2-L-COO]− is not less than 0.86 and not more than 1.12. A weight ratio of the water to the ionic liquid composition is not more than 4.7%. The present invention provides an ionic liquid capable of dissolving cellulose without an cellulose-degrading enzyme (namely, an enzyme capable of hydrolyzing cellulose).

First claim

The invention claimed is:

1. A solution in which cellulose has been dissolved in an ionic liquid, wherein the ionic liquid is represented by the following chemical formula (I):
[(CH 3 ) 3 N(CH 2 ) 2 OH] + [NH 2 -L-COO] −   (I)

where L is —(CH 2 ) 2 — or —(CH 2 ) 3 —.

2. The solution according to claim 1 , wherein
L is —(CH 2 ) 2 —.

3. The solution according to claim 1 , wherein
L is —(CH 2 ) 3 —.

4. A solution in which cellulose has been dissolved in an ionic liquid composition, wherein
the ionic liquid composition containing:
an ionic liquid; and
water,

the ionic liquid is represented by the following chemical formula (I):
[(CH 3 ) 3 N(CH 2 ) 2 OH] + [NH 2 -L-COO] −   (I)

where L is —(CH 2 ) 2 — or —(CH 2 ) 3 —;

a molar ratio of [(CH 3 ) 3 N(CH 2 ) 2 OH] + to [NH 2 -L-COO] − is not less than 0.86 and not more than 1.12; and
a weight ratio of the water to the ionic liquid composition is not more than 4.7%.

5. The solution according to claim 4 , wherein
the ionic liquid composition does not contain an enzyme capable of hydrolyzing cellulose.

6. The solution according to claim 4 , wherein
the molar ratio of [(CH 3 ) 3 N(CH 2 ) 2 OH] + to [NH 2 -L-COO] − is not less than 0.89 and not more than 1.10.

7. The solution according to claim 4 , wherein
the weight ratio of the water to the ionic liquid composition is not less than 1.6%.

8. The solution according to claim 4 , further containing:
an aprotic polar solvent.

9. The solution according to claim 4 , wherein
the aprotic polar solvent is dimethyl sulfoxide.

10. The solution according to claim 4 , wherein
a weight ratio of the dimethyl sulfoxide to the ionic liquid is not more than 309%.

11. The solution according to claim 4 , wherein
L is —(CH 2 ) 2 —.

12. The solution according to claim 4 , wherein
L is —(CH 2 ) 3 —.

13. A method for dissolving cellulose, the method comprising:
(a) adding cellulose to an ionic liquid composition;
wherein
the ionic liquid composition contains an ionic liquid and water;
the ionic liquid is represented by the following chemical formula (I):
[(CH 3 ) 3 N(CH 2 ) 2 OH] + [NH 2 -L-COO] −   (I)

where L is —(CH 2 ) 2 — or —(CH 2 ) 3 —;

a molar ratio of [(CH 3 ) 3 N(CH 2 ) 2 OH] + to [NH 2 -L-COO] − is not less than 0.86 and not more than 1.12; and
a weight ratio of the water to the ionic liquid composition is not more than 4.7%.

14. The method according to claim 13 , wherein
the ionic liquid composition does not contain an enzyme capable of hydrolyzing cellulose.

15. The method according to claim 13 , wherein
the molar ratio of [(CH 3 ) 3 N(CH 2 ) 2 OH] + to [NH 2 -L-COO] − is not less than 0.89 and not more than 1.10.

16. The method according to claim 13 , wherein
the weight ratio of the water to the ionic liquid composition is not less than 1.6%.

17. The method according to claim 13 , further comprising:
(b1) heating the ionic liquid composition to which the cellulose has been added to dissolve the cellulose in the ionic liquid composition, after the step (a).

18. The method according to claim 13 , further comprising:
(b2) leaving the ionic liquid composition to which the cellulose has been added at rest to dissolve the cellulose in the ionic liquid composition, after the step (a).

19. The method according to claim 13 , further comprising:
(b3) stirring the ionic liquid composition to which the cellulose has been added to dissolve the cellulose in the ionic liquid composition, after the step (a).

20. The method according to claim 13 , wherein the ionic liquid composition further contains an aprotic polar solvent.

21. The method according to claim 20 , wherein
the aprotic polar solvent is dimethyl sulfoxide.

22. The method according to claim 21 , wherein
a weight ratio of the dimethyl sulfoxide to the ionic liquid is not more than 309%.

23. The method according to claim 13 , wherein
L is —(CH 2 ) 2 —.

24. The method according to claim 13 , wherein
L is —(CH 2 ) 3 —.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Aoki Takahiro
• Kawashima Tomoko
• Kusukame Haruka
• Taniike Yuko

Classifications

• C07C215/40 Primary

  with quaternised nitrogen atoms bound to carbon atoms of the carbon skeleton · CPC title

• C08B1/003

  Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids (solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02) · CPC title

• C08J3/096 Primary

  Nitrogen containing compounds · CPC title

• C08J2301/02

  Cellulose; Modified cellulose · CPC title

• C08J5/18

  Manufacture of films or sheets · CPC title