WE CLAIM:
1. A method for producing an emulsion of a nitrogen atom-containing polymer or a salt
thereof, the method comprising:
a step of mixing a first solution that includes a nitrogen atom-containing polymer or a salt thereof and a hydrophilic solvent and has a viscosity of 10 to 2,000 mPa-s, and a second solution that includes a hydrophobic solvent and has a viscosity of 1 to 100 mPa-s, stirring the mixture, and thus obtaining an emulsion of the nitrogen atom-containing polymer or a salt thereof,
wherein a ratio between the viscosity of the first solution and the viscosity of the second solution is in a range of 0.1:1 to 300:1.
2. The method according to claim 1, wherein the viscosity of the first solution is 10 to 1,500 mPas.
3. The method according to claim 1 or 2, wherein the ratio between the viscosity of the first solution and the viscosity of the second solution is in a range of 0.2:1 to 100:1.
4. The method according to any one of claims 1 to 3, wherein an amine value of the nitrogen atom-containing polymer or a salt thereof is 10 mmol/g or more.
5. The method according to any one of claims 1 to 4, wherein the nitrogen atom-containing polymer is at least one selected from the group consisting of polyallylamine, a polyalkyleneimine, and polyvinylamine.
6. The method according to any one of claims 1 to 4, wherein the nitrogen atom-containing polymer includes polyallylamine.
7. The method according to any one of claims 1 to 6, wherein the second solution includes an emulsifier having a weight-average molecular weight or a number-average molecular weight of 2,000 or more.
8. The method according to claim 7, wherein the emulsifier includes a sugar.
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9. The method according to claim 7 or 8, wherein the emulsifier includes cellulose ether.
10. The method according to any one of claims 1 to 9, wherein the hydrophobic solvent is at least one selected from the group consisting of an aromatic hydrocarbon-based solvent, an ester-based solvent, and olive oil.
11. The method according to any one of claims 1 to 10, wherein an average particle diameter of emulsified particles of the emulsion of a nitrogen atom-containing polymer or a salt thereof is 1 to 200 [jm.
12. An emulsion, comprising:
spherical objects formed from a first solution including a nitrogen atom-containing polymer or a salt thereof and a hydrophilic solvent and having a viscosity of 10 to 2,000 mPa-s; and
a dispersing medium including a second solution including a hydrophobic solvent and having a viscosity of 1 to 100 mPa-s,
wherein a ratio between the viscosity of the first solution and the viscosity of the second solution is in a range of 0.1:1 to 300:1.
13. A method for producing particles containing a crosslinked nitrogen atom-containing
polymer or a salt thereof, the method comprising:
a step of mixing a first solution that includes a nitrogen atom-containing polymer or a salt thereof and a hydrophilic solvent and has a viscosity of 10 to 2,000 mPa-s, and a second solution that includes a hydrophobic solvent and has a viscosity of 1 to 100 mPa-s, stirring the mixture, and thus obtaining an emulsion of the nitrogen atom-containing polymer or a salt thereof; and
a step of adding a crosslinking agent to the emulsion in which the nitrogen atom-containing polymer or a salt thereof is emulsified, and performing a crosslinking reaction,
wherein a ratio between the viscosity of the first solution and the viscosity of the second solution is in a range of 0.1:1 to 300:1.
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14. The method for producing particles according to claim 13, wherein the nitrogen atom-containing polymer is a crosslinked polymer having a substituent containing an NR^R^ structure: in Formula, RA1 and R^ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aminoalkyl group having 1 to 20 carbon atoms or a salt thereof, an alkylaminoalkyl group having 2 to 20 carbon atoms or a salt thereof, a dialkylaminoalkyl group having 3 to 20 carbon atoms or a salt thereof, a trialkylammoniumalkyl group having 4 to 20 carbon atoms, an alkylcarbonyl group having 1 to 20 carbon atoms, a carboxyalkyl group having 1 to 20 carbon atoms, or a hydroxyalkyl group having 1 to 20 carbon atoms.
15. The method for producing particles according to claim 13 or 14, wherein the particles have an average particle diameter of 20 to 150 urn and a swelling rate of 9 to 16 ml/g, provided that the average particle diameter is determined by converting areas of 1,000 or more particle images of optical microscopic photographs into diameters, and calculating the average particle diameter as the volume average particle diameter using those diameters, and the swelling rate is determined by swelling particles by repeating shaking and standing for one hour or longer in an aqueous solution at pH 6.3 of 2.2% by mass of sodium 2-morpholinoethanesulfonate and 0.5% by mass of sodium chloride at 20°C twenty or more times, and calculating the swelling rate by dividing the particle volume after swelling by the particle mass before swelling.
16. The method for producing particles according to any one of claims 13 to 15, wherein each of the particles has an outer shell portion and a central portion having a lower degree of crosslinking than the outer shell portion.
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