Polar solvent solution and production method thereof
A polar solvent solution of the present invention is a polar solvent solution in which a solute containing a polyamine acid is dissolved in a polar solvent. The solution has a moisture content of less than 5 mass % based on 100 mass % of the solution. A method for producing a polar solvent solution of the present invention includes changing a moisture content of the solution to adjust the viscosity of the solution. Further, another method for producing a polar solvent solution includes reducing a moisture content of the solution to increase the viscosity of the solution. Thus, the present invention provides a polar solvent solution that enables stable spinning and casting without lowering its viscosity when used as dopes for spinning, film, etc., and methods for producing the same.
1. A method for producing a polar solvent solution in which a solute containing a polyamino acid is dissolved in a polar solvent, comprising:
changing a water content of the solution to adjust the viscosity of the solution,
wherein the solution has a water content of less than 5% by mass based on 100% by mass of the solution, and
the polar solvent comprises at least one selected from the group consisting of dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and N-methyl-2-pyrrolidone (NMP).
2. A method for producing a polar solvent solution in which a solute containing a polyamino acid is dissolved in a polar solvent, comprising:
reducing a water content of the solution to increase the viscosity of the solution,
wherein the solution has a water content of less than 5% by mass based on 100% by mass of the solution, and
the polar solvent comprises at least one selected from the group consisting of dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and N-methyl-2-pyrrolidone (NMP).
3. The method for producing a polar solvent solution according to claim 1 , wherein the polyamino acid is a polypeptide.
4. The method for producing a polar solvent solution according to claim 1 , wherein the solute containing the polyamino acid is dried to reduce a water content of the solute, prior to dissolving the solute in the polar solvent.
5. The method for producing a polar solvent solution according to claim 1 , wherein the water content of the solution is changed by adjusting a relative humidity of an atmosphere in the production and/or storage of the solution.
6. The method for producing a polar solvent solution according to claim 5 , wherein the relative humidity of the atmosphere in the production and/or storage of the solution is adjusted to 1.3% RH or less.
7. The method for producing a polar solvent solution according to claim 2 , wherein the polyamino acid is a polypeptide.
8. The method for producing a polar solvent solution according to claim 2 , wherein the solute containing the polyamino acid is dried to reduce a water content of the solute, prior to dissolving the solute in the polar solvent.
9. The method for producing a polar solvent solution according to claim 2 , wherein the water content of the solution is changed by adjusting a relative humidity of an atmosphere in the production and/or storage of the solution.
10. The method for producing a polar solvent solution according to claim 9 , wherein the relative humidity of the atmosphere in the production and/or storage of the solution is adjusted to 1.3% RH or less.
11. The method for producing a polar solvent solution according to claim 1 , wherein the solution exhibits at least one of the following viscosity properties (a) to (f):
(a) a viscosity in a range from 100 to 434 mPa·s at 25° C.;
(b) a viscosity in a range from 100 to 333 mPa·s at 30° C.;
(c) a viscosity in a range from 100 to 221 mPa·s at 40° C.;
(d) a viscosity in a range from 89 to 153 mPa·s at 50° C.;
(e) a viscosity in a range from 63 to 110 mPa·s at 60° C.; and
(f) a viscosity in a range from 49 to 82 mPa·s at 70° C.
12. The method for producing a polar solvent solution according to claim 2 , wherein the solution exhibits at least one of the following viscosity properties (a) to (f):
(a) a viscosity in a range from 100 to 434 mPa·s at 25° C.;
(b) a viscosity in a range from 100 to 333 mPa·s at 30° C.;
(c) a viscosity in a range from 100 to 221 mPa·s at 40° C.;
(d) a viscosity in a range from 89 to 153 mPa·s at 50° C.;
(e) a viscosity in a range from 63 to 110 mPa·s at 60° C.; and
(f) a viscosity in a range from 49 to 82 mPa·s at 70° C.