Solvent System Based on Molten Ionic Liquids, Its Production and Use for Producing Regenerated Carbohydrates

• US 20080269477A1
• Filed: 12/22/2006
• Published: 10/30/2008
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Deutsche Institute fur Textil- und Faserforschung Denkendorf
• Original Assignee: BASF SE
• Inventors: Massonne, Klemens, Maase, Matthias, Hermanutz, Frank, Stegmann, Veit, Lutz, Michael, Gaehr, Frank, Uerdingen, Eric
• Granted Patent: US 8,163,215 B2
• Time in Patent Office: Days
• US Class Current: 536/57
• CPC Class Codes: C08B 1/003 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 Class Codes: C08B 16/00 Regeneration of cellulose
• CPC Class Codes: C08J 2301/02 Cellulose; Modified cellulose
• CPC Class Codes: C08J 3/096 Nitrogen containing compounds
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 2666/26 Natural polymers, natural resins or derivatives thereof according to C08L1/00 - C08L5/00, C08L89/00, C08L93/00, C08L97/00 or C08L99/00
• CPC Class Codes: C08L 3/00 Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
• CPC Class Codes: C08L 3/02 Starch; Degradation products thereof, e.g. dextrin
• CPC Class Codes: C08L 3/12 Amylose; Amylopectin; Degradation products thereof
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
• CPC Class Codes: D01F 2/02 from solutions of cellulose in acids, bases or salts
• CPC Class Codes: Y02P 20/54 using solvents, e.g. supercritical solvents or ionic liquids
• CPC Class Codes: Y10T 428/2965 Cellulosic

Abstract

A solution system for biopolymers in the form of carbohydrates based on a molten ionic liquid, additives optionally being contained in the solution system, is described. This solution system contains a protic solvent or a mixture of several protic solvents, and in the case where the protic solvent is solely water, this is present in the solution system in an amount of more than about 5 wt. %. Carbohydrates can be incorporated into the solution system, in particular in the form of starch, cellulose and derivatives thereof, and it can then be used for regeneration of the carbohydrates contained therein. A particularly advantageous process for the preparation of the solution system containing the carbohydrates and for the preparation of regenerated carbohydrates, in particular in the form of regenerated cellulose fibers, is moreover described. The invention accordingly also provides such spun fibers as are distinguished in that they are non-fibrillating. The invention offers in particular economic advantages over the systems of the prior art.

Claims

1. A process for the preparation of regenerated biopolymers in the form of carbohydrates, using a solution system containing comprising the biopolymers, wherein the solution system is based on a molten ionic liquid and a protic solvent or a mixture of several protic solvents, wherein, in the case where the protic solvent is solely water, the water is present in the solution system in an amount of more than 5 wt. %, the biopolymers dissolved in the solution system are precipitated in a coagulation medium, the coagulation medium comprising a solvent which does not dissolve the biopolymers and is miscible with the molten ionic liquid.

2. The process according to claim 1, wherein the ionic liquid comprises a substituted or unsubstituted imidazolium cation as the cation.

4. The process according to claim 1, wherein the solution system contains comprises about 6 to 15 wt. % of water as the protic solvent.

5. The process according to claim 1, wherein the solution system comprises the protic solvent, with the exception of water, in an amount of at least 0.1 wt. %.

6. The process according to claim 5, wherein the solution system comprises the protic solvent in an amount of from about 1 to 10 wt. %.

7. The process according to claim 1, wherein the solution system contains comprises as the protic solvent methanol, ethanol, 1-propanol, 2-propanol and/or 1-butanol.

8. The process according to claim 2, wherein the imidazolium cation of the ionic liquid is substituted by (C₁-C₆)-alkyl groups in the 1- and 3-position or in the 1-, 2- and 3-position.

9. The process according to claim 8, wherein the imidazolium cation is 1-ethyl-3-methylimidazolium, 1,3-dimethylimidazolium or 1-butyl-3-methylimidazolium cation.

10. The process according to claim 1, wherein the anion of the ionic liquid is a halide, perchlorate, pseudohalide, sulfate, phosphate, alkyl-phosphate or a C₁-C₆-carboxylate ion.

12. The process according to claim 1, wherein the molten ionic liquid has a melting point of from −

100 to +150°

C.

13. The process according to claim 1, wherein the ionic liquid is present as 1-ethyl-3-methylimidazolium acetate, 1,3-dimethylimidazolium acetate, 1-ethyl-3-methyl-imidazolium chloride, 1-butyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium diethylphosphate, 1-methyl-3-methylimidazolium dimethylphosphate, 1-ethyl-3-methylimidazolium formate, 1-ethyl-3-methylimidazolium octanoate, 1,3-diethylimidazolium acetate and 1-ethyl-3-methylimidazolium propionate.

14. The process according to claim 1, wherein the carbohydrate is cellulose dissolved in the solution system or a derivative thereof and has an average degree of polymerization of from about 200 to 3,500 and wherein the cellulose and/or derivative thereof is present in the solution system in an amount of from about 1 to 35 wt. %.

18. The process according to claim 1, wherein esters or ethers are used as derivatives of starch and cellulose as the carbohydrates.

22. The process according to claim 1, wherein the solution system has a zero viscosity (measured with a rotary viscometer) of between about 5 and 150,000 Pa·

s.

26. The process according to claim 1, wherein the solution system is subjected to wet spinning.

27. The process according to claim 1, wherein the solution system comprising the biopolymers is used as a spinning solution for the production of non-fibrillated fibers.

28. The process according to claim 26, wherein an air gap spinning unit is employed in order to obtain staple fibers having a high degree of crystallinity (CI>

0.5).

30. The process according to claim 1, wherein to adjust specific properties of the precipitated material obtained, additives are added, the additives being added to the coagulation medium, the solution system and/or a subsequent modification bath.

31. The process according to claim 30, wherein additives in the form of microcapsules, pore-forming agents, plasticizers, matting agents, flameproofing agents, bactericides, crosslinking agents, hydrophobizing agents, antistatics and/or coloring agents are used.

32. The process according to claim 1, wherein an alcohol, a mixture of alcohols or a mixture of alcohol(s) with water or solely water is used as the precipitating or coagulation medium and no additives are added.

34. The process according to claim 1, wherein the biopolymers in the form of carbohydrates precipitated out in the coagulation medium, are separated off and the liquid phase which remains is recovered, optionally after partial evaporation, for the preparation of the original solution system and is employed again for the preparation of the solution system comprising the biopolymers in the form of carbohydrates.

37. A regenerated biopolymer in the form of carbohydrates, obtained by the process according to claim 1.

55. The process according to claim 32, wherein the alcohol is methanol, ethanol, propanol and/or butanol.

3. (canceled)

11. (canceled)

15-17. -17. (canceled)

19-21. -21. (canceled)

23-25. -25. (canceled)

29. (canceled)

33. (canceled)

35-36. -36. (canceled)

38. A spun fiber based on regenerated cellulose having a wet fibrillation rating of less than or equal to 2.

39. The spun fiber according to claim 38, which has a content of sulfur of less than 1 mg/g and a copper content of less than 20 μ

g/g.

41. The spun fiber according to claim 39, wherein the sulfur content is less than 0.5 mg/g and the copper content is less than 10 μ

g/g.

42. The spun fiber according to claim 39, wherein data on the sulfur and copper content relate to a non-washed spun fiber emerging from a coagulation bath.

43. The spun fiber according to claim 38, wherein the water retention capacity of the spun fiber is between about 50 and 300% (according to DIN 53184).

44. The spun fiber according to claim 38, wherein the maximum tensile force is at least 6 cN/tex and/or the maximum tensile force elongation is at least 4% (according to DIN EN ISO 2062).

40. A spun fiber based on regenerated cellulose which is non-fibrillating and has a content of sulfur of less than 1 mg/g and a copper content of less than 20 μ

g/g.

45. A solution system for biopolymers in the form of carbohydrates based on a molten ionic liquid and a protic solvent or a mixture of several protic solvents, additives optionally being present in the solution system, wherein the molten ionic liquid has a melting point of from −

100 to +150°

C. and, in the case where the protic solvent is solely water, the water is contained present in the solution system in an amount of more than about 5 wt. %.

47. A process for the preparation of a solution system according to claim 45, wherein the biopolymers in the form of carbohydrates, based on the molten ionic liquid are mixed with a sufficient amount of a protic solvent or mixture of several protic solvents until the biopolymer in the form of carbohydrates has dissolved, and wherein in the case of the sole use of water as the protic solvent, the water is present in the solution system in an amount of more than 5 wt. %.

48. The process according to claim 47, wherein the mixing is carried out in an extruder.

46. (canceled)

49-54. -54. (canceled)