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 polyamino 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 polar solvent solution in which a solute containing a polyamino acid is dissolved in a polar solvent,
wherein the solution has a moisture content of less than 5% by mass based on 100% by mass of the solution.
2 . The polar solvent solution according to claim 1 , wherein the polyamino acid is a polypeptide.
3 . The polar solvent solution according to claim 1 , wherein the polar solvent contains 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).
4 . The polar solvent solution according to claim 2 , wherein the polypeptide is a structural protein.
5 . The polar solvent solution according to claim 4 , wherein the structural protein includes a crystal region.
6 . The polar solvent solution according to claim 2 , wherein the polypeptide is a spider silk protein.
7 . 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 moisture content of the solution to adjust a viscosity of the solution.
8 . 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 moisture content of the solution to increase a viscosity of the solution.
9 . The method for producing a polar solvent solution according to claim 7 , wherein the polyamino acid is a polypeptide.
10 . The method for producing a polar solvent solution according to claim 7 , wherein the solution has a moisture content of less than 5% by mass based on 100% by mass of the solution.
11 . The method for producing a polar solvent solution according to claim 7 , wherein the polar solvent contains 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).
12 - 14 . (canceled)
15 . The method for producing a polar solvent solution according to claim 7 , wherein the moisture content of the solution is changed by drying the solute containing the polyamino acid and thereafter dissolving it in the polar solvent.
16 . The method for producing a polar solvent solution according to claim 7 , wherein the moisture content of the solution is changed by adjusting a relative humidity of an atmosphere in the production and/or storage of the solution.
17 . The method for producing a polar solvent solution according to claim 16 , wherein the relative humidity of the atmosphere in the production and/or storage of the solution is adjusted to 1.3% RH or less.
18 . The method for producing a polar solvent solution according to claim 8 , wherein the polyamino acid is a polypeptide.
19 . The method for producing a polar solvent solution according to claim 8 , wherein the solution has a moisture content of less than 5% by mass based on 100% by mass of the solution.
20 . The method for producing a polar solvent solution according to claim 8 , wherein the polar solvent contains 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).
21 . The method for producing a polar solvent solution according to claim 8 , wherein the moisture content of the solution is changed by drying the solute containing the polyamino acid and thereafter dissolving it in the polar solvent.
22 . The method for producing a polar solvent solution according to claim 8 , wherein the moisture content of the solution is changed by adjusting a relative humidity of an atmosphere in the production and/or storage of the solution.
23 . The method for producing a polar solvent solution according to claim 22 , wherein the relative humidity of the atmosphere in the production and/or storage of the solution is adjusted to 1.3% RH or less.