Ink-jet recording ink, ink-jet recording ink set, ink cartridge, ink-jet printer, and ink-jet printing method

• US 20050054751A1
• Filed: 08/05/2004
• Published: 03/10/2005
• Est. Priority Date: 02/05/2002
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nagai, Kiyofumi, Gotoh, Akihiko, Namba, Michihiko, Tokuno, Toshiroh
• Granted Patent: US 7,094,813 B2
• Time in Patent Office: Days
• US Class Current: 523/160
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/40 Ink-sets specially adapted for multi-colour inkjet printing

Abstract

An ink and ink set characterized in that both a combination of a specific wetting agent, penetrating agent, and water-soluble organic solvent and use of surfactant, particularly fluorine surfactant are enabled by using water dispersion in which polymer fine particles contain coloring material. Even when plain paper is printed at high speed by ink-jet recording by using this ink and ink set, the ink and ink set can realize a pigment ink for ink-jet recording, an ink set, an ink-jet recording method, ink cartridge, and recorder which have an excellent ejection stability and excellent preservability, and provide (1) good color tone, (2) high image density, (3) recorded image free of unsharpness near character or image and feathering and high in sharpness, (4) less boundary color bleedings between different colors, (5) image adaptable to both-side printing and causing less strike-throughs, and (6) image fastness such as water resistance and light resistance.

Claims

1. An ink-jet recording ink, comprising:

a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane;

one of

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms;

a water-soluble organic solvent;

water;

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; and

at least one fluorine surfactant,

wherein the ink-jet recording ink has a viscosity of 5 mPa.sec or more at 25°

C.

2. The ink-jet recording ink according to claim 1, wherein the viscosity of the ink-jet recording ink is 8 mPa.sec to 20 mPa.sec at 25°

C.

3. The ink-jet recording ink according to claim 1, wherein the ink-jet recording ink has a surface tension 40 dyne/cm or less.

4. The ink-jet recording ink according to claim 1, wherein a content of the polymer emulsion comprising the coloring material is 8 weight % to 20 weight % as solid content.

5. The ink-jet recording ink according to claim 1, wherein a content of the wetting agent is 10 weight % to 50 weight %.

6. The inkjet recording ink according to claim 1, wherein a weight ratio of the wetting agent to the polymer emulsion as the solid content is 2 to 5.

7. The ink-jet recording ink according to claim 1, wherein the ink-jet recording ink comprising the polymer emulsion comprising the coloring material has an average particle diameter 0.16 μ

m or less.

8. The ink-jet recording ink according to claim 1, wherein a content of the fluorine surfactant is 0.05 weight % to 5 weight %.

9. The ink-jet recording ink according to claim 1, wherein one of a vinyl polymer and a polyester polymer constitutes the polymer emulsion.

10. The ink-jet recording ink according to claim 1, wherein one of the polyol, as the second hydroxy compound, having the 8 to 11 carbon atoms, and the glycol ether having the 8 to 11 carbon atoms comprises 2-ethyl-1,3-hexane diol.

11. The ink-jet recording ink according to claim 1, wherein one of the polyol, as the second hydroxy compound, having the 8 to 11 carbon atoms, and the glycol ether having the 8 to 11 carbon atoms comprises 2,2,4-trimethyl-1,3-pentane diol.

12. The ink-jet recording ink according to claim 1, wherein the fluorine surfactant is at least one selected from the group consisting of perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphoric acid ester, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and perfluoroalkyl amineoxide compound.

13. The ink-jet recording ink according to claim 12, wherein the fluorine surfactant in the ink-jet recording ink is the perfluoroalkyl sulfonate expressed by the following formula A, and uses a pigment as the coloring material:

14. The ink-jet recording ink according to claim 12, wherein

at least one of the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant is selected from the group consisting of surfactants expressed respectively by the following formulas (I), (II), (III), (IV), (V), (VI), (VII), (VIII), and (IX), and

the at least one of the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant comprises the at least one fluorine surfactant according to claim 12:

R₁—

O—

(CH₂CH₂O)mCH₂COOM  

 

(I)

wherein R₁ denotes a branchable alkyl group having 6 to 14 carbon atoms, m denotes an integer of 3 to 12, M denotes an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, and an alkanolamine,

wherein R₂ denotes a branched alkyl group having 5 to 16 carbon atoms, M denotes an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, and an alkanolamine,

wherein R denotes a branchable carbon chain having 6 to 14 carbon atoms, and k denotes an integer of 5 to 20,

R—

(OCH₂CH₂)nOH  

 

(IV)

wherein R is a branchable carbon chain having 6 to 14 carbon atoms, and n denotes an integer of 5 to 20,

wherein R denotes a branchable carbon chain having 6 to 14 carbon atoms, and J, k, m, n;

j, k, m, n≦

20,

wherein R′

denotes a carbon chain having 6 to 14 carbon atoms, and J, k, m, n;

j, k, m, n≦

20,

wherein p and q are integers of 0 to 40,

wherein each of R₁ and R₂ denotes an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms, R₃ denotes an alkyl group having 10 to 20 carbon atoms or an alkenyl group having 10 to 20 carbon atoms,

wherein each of R₁ and R₂ denotes an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms, R₃ denotes an alkyl group having 10 to 16 carbon atoms, wherein R₃ is allowed to contain an amide group, otherwise, R₃ is an alkyl group derived from a coconut oil.

15. The ink-jet recording ink according to claim 1, further comprising a compound expressed by the following formula:

HO—

(CH₂)n-OH

wherein n denotes an integer of 5, 7 and 8.

16. The ink-jet recording ink according to claim 1, further comprising at least one of:

a polyol as a third hydroxy compound other than the first hydroxy compounds and the second hydroxy compound,

a lactam,

a carbamide,

an alkyl glycine,

a betaine compound, and

a saccharide.

17. The ink-jet recording ink according to claim 16, wherein the third hydroxy compound comprises one selected from the group consisting of ethylene glycol, tetraethylene glycol, hexylene glycol, polyethylene glycol, tripropylene glycol, 2,3-butane diol, 1,3-propane diol, 1,4-butane diol, 2-methyl-2,4-pentane diol, 1,2,4-butane triol, 1,2,6-hexane triol, thiodiglycol, and pentaerythritol.

18. The ink-jet recording ink according to claim 16, wherein the lactam comprises one selected from the group consisting of 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, and P-caprolactam.

19. The ink-jet recording ink according to claim 16, wherein the carbamide comprises one selected from the group consisting of urea, thiocarbamide, ethylene carbamide, 1,3-dimethyl-2-imidazolidinone.

20. The ink-jet recording ink according to claim 16, wherein the saccharide comprises one selected from the group consisting of maltitol, sorbitol, gluconolactone, and maltose.

21. An ink-jet recording ink set, comprising:

a black ink; and

at least one color ink,

wherein the black ink comprises;

a self-dispersion type pigment,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant,

a water-soluble organic solvent, and

water,

wherein the black ink has a viscosity of 5 mPa.sec or more at 25°

C.,

wherein the color ink comprises;

a water dispersion which is a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

a water-soluble organic solvent,

water,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant, and

at least one fluorine surfactant,

wherein the color ink has a viscosity of 5 mPa.sec or more at 25°

C.

22. The ink-jet recording ink set according to claim 21, wherein the viscosity of the ink is 8 mPa.sec to 20 mPa.sec at 25°

C.

23. The ink-jet recording ink set according to claim 21, wherein the ink-jet recording ink set has a surface tension 40 dyne/cm or less.

24. The ink-jet recording ink set according to claim 21, wherein a content of at least one of the pigment and the polymer emulsion is 8 weight % to 20 weight % as solid content.

25. The ink-jet recording ink set according to claim 21, wherein a content of the wetting agent is 10 weight % to 50 weight %.

26. The inkjet recording ink set according to claim 21, wherein an average particle diameter of a particle contained is 0.16 μ

m or less.

27. The ink-jet recording ink set according to claim 21, wherein the self-dispersion type pigment comprises on a surface thereof at least one hydrophilic group selected from the group consisting of a carboxyl group, a sulfone group, a carbonyl group, and a hydroxyl group.

28. The ink-jet recording ink set according to claim 21, wherein the self-dispersion type pigment comprises on a surface thereof, via at least another atomic group, at least one hydrophilic group selected from the group consisting of a carboxyl group, a sulfone group, a carbonyl group, and a hydroxyl group.

29. The ink-jet recording ink set according to claim 21, wherein one of the polyol, as the second hydroxy compound, having the 8 to 11 carbon atoms, and the glycol ether having the 8 to 11 carbon atoms comprises 2-ethyl-1,3-hexane diol.

30. The ink-jet recording ink set according to claim 21, wherein one of the polyol, as the second hydroxy compound, having the 8 to 11 carbon atoms, and the glycol ether having the 8 to 11 carbon atoms comprises 2,2,4-trimethyl-1,3-pentane diol.

31. The ink-jet recording ink set according to claim 21, wherein

the fluorine surfactant is at least one selected from the group consisting of perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphoric acid ester, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and perfluoroalkyl amineoxide compound, and

a content of the fluorine surfactant is 0.05 weight % to 5 weight %.

32. The inkjet recording ink set according to claim 31, wherein the fluorine surfactant in the ink is the perfluoroalkyl sulfonate expressed by the following formula A, and uses a pigment as the coloring material:

33. The ink-jet recording ink set according to claim 31, wherein

at least one of the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant is selected from the group consisting of surfactants expressed respectively by the following formulas (I), (II), (III), (IV), (V), (VI), (VII), (VIII), and (IX), and

the at least one of the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant comprises the at least one fluorine surfactant according to claim 31:

R₁—

O—

(CH₂CH₂O)mCH₂COOM  

 

(I)

wherein R₁ denotes a branchable alkyl group having 6 to 14 carbon atoms, m denotes an integer of 3 to 12, M denotes an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, and an alkanolamine,

wherein R₂ denotes a branched alkyl group having 5 to 16 carbon atoms, M denotes an alkali metal ion, a quaternary ammonium, a quaternary phosphonium, and an alkanolamine,

wherein R denotes a branchable carbon chain having 6 to 14 carbon atoms, and k denotes an integer of 5 to 20,

R—

(OCH₂CH₂)nOH  

 

(IV)

wherein R is a branchable carbon chain having 6 to 14 carbon atoms, and n denotes an integer of 5 to 20,

wherein R denotes a branchable carbon chain having 6 to 14 carbon atoms, and J, k, m, n;

j, k, m, n≦

20,

wherein R′

denotes a carbon chain having 6 to 14 carbon atoms, and J, k, m, n;

j, k, m, n≦

20,

wherein p and q are integers of 0 to 40,

wherein each of R₁ and R₂ denotes an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms, R₃ denotes an alkyl group having 10 to 20 carbon atoms or an alkenyl group having 10 to 20 carbon atoms,

wherein each of R₁ and R₂ denotes an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group having 1 to 3 carbon atoms, R₃ denotes an alkyl group having 10 to 16 carbon atoms, wherein R₃ is allowed to contain an amide group, otherwise, R₃ is an alkyl group derived from a coconut oil.

34. The ink-jet recording ink set according to claim 21, further comprising a compound expressed by the following formula:

HO—

(CH₂)n-OH

wherein n denotes an integer of 5, 7 and 8.

35. The ink-jet recording ink set according to claim 21, further comprising at least one of:

a polyol as a third hydroxy compound other than the first hydroxy compounds and the second hydroxy compound,

a lactam,

a carbamide,

an alkyl glycine,

a betaine compound, and

a saccharide.

36. An ink-jet printing method for ejecting an ink by applying an energy to an ink-jet recording ink,

wherein the ink-jet recording ink comprises:

a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane;

one of

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms;

a water-soluble organic solvent;

water;

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; and

at least one fluorine surfactant,

wherein the ink-jet recording ink has a viscosity of 5 mPa.sec or more at 25°

C.

37. The ink-jet printing method according to claim 36, wherein the ink is ejected by applying thereto a heat energy.

38. The ink-jet printing method according to claim 36, wherein the ink is ejected by applying thereto a dynamic energy.

39. The ink-jet printing method according to claim 36, wherein the ink-jet recording ink is used under the following conditions:

an Mj of 5 pl to 35 pl, a Vj of 6 m to 20 m, a frequency of 1 kHz or more, a resolution of 300 dpi or more, and one pass printing, the Mj denoting a size of a droplet of the ink ejected from a nozzle, and the Vj denoting a velocity of the droplet of the ink ejected from the nozzle.

40. An ink-jet printing method for ejecting an ink by applying an energy to an ink-jet recording ink set,

wherein the ink-jet recording ink set comprises:

a black ink; and

p1 at least one color ink,

wherein the black ink comprises;

a self-dispersion type pigment,

at least one wetting agent, as a first hydroxy compound, 2 0 selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant,

a water-soluble organic solvent, and

water,

wherein the black ink has a viscosity of 5 mPa.sec or more at 25°

C.,

wherein the color ink comprises;

a water dispersion which is a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

a water-soluble organic solvent,

water,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant, and

at least one fluorine surfactant,

wherein the color ink has a viscosity of 5 mPa.sec or more at 25°

C.

41. The ink-jet printing method according to claim 40, wherein the ink is ejected by applying thereto a heat energy.

42. The ink-jet printing method according to claim 40, wherein the ink is ejected by applying thereto a dynamic energy.

43. The ink-jet printing method according to claim 40, wherein the ink-jet recording ink set is used under the following conditions:

an Mj of 5 pl to 35 pl, a Vj of 6 m to 20 m, a frequency of 1 kHz or more, a resolution of 300 dpi or more, and one pass printing, the Mj denoting a size of a droplet of the ink ejected from a nozzle, and the Vj denoting a velocity of the droplet of the ink ejected from the nozzle.

44. An ink cartridge, comprising an ink receiver receiving therein an ink-jet recording ink,

wherein the ink-set recording ink comprises:

a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane;

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms;

a water-soluble organic solvent;

water;

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; and

at least one fluorine surfactant,

wherein the ink-jet recording ink has a viscosity of 5 mPa.sec or more at 25°

C.

45. An ink cartridge, comprising an ink receiver receiving therein an ink-jet recording ink set,

wherein the ink-jet recording ink set comprises:

a black ink; and

at least one color ink,

wherein the black ink comprises;

a self-dispersion type pigment,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant,

a water-soluble organic solvent, and

water,

wherein the black ink has a viscosity of 5 mPa.sec or more at 25°

C.,

wherein the color ink comprises;

a water dispersion which is a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

a water-soluble organic solvent,

water,

at least one of an anionic surfactant, a nonionic surfactant,

and an amphoteric surfactant, and

at least one fluorine surfactant,

wherein the color ink has a viscosity of 5 mPa.sec or more at 25°

C.

46. An ink-jet printer, comprising:

one of an ink receiver and an ink cartridge receiving therein;

an ink-jet recording ink; and

one of an ink-jet recording head and a record unit which drops and ejects the ink by an action of an energy,

wherein the ink-jet recording ink comprises;

a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane;

one of

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms;

a water-soluble organic solvent;

water;

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; and

at least one fluorine surfactant,

wherein the ink-jet recording ink has a viscosity of 5 mPa.sec or more at 25°

C.

47. The ink-jet printer according to claim 46, wherein the ink-jet recording head has a nozzle plate which has a surface formed with an ink-repellent coating layer subjected to a eutectic plating.

48. The ink-jet printer according to claim 46, wherein the ink-jet recording head has a nozzle diameter of 30 μ

m or less.

49. An ink-jet printer, comprising:

one of an ink receiver and an ink cartridge receiving therein;

an ink-jet recording ink set; and

one of an ink-jet recording head and a record unit which drops and ejects the ink by an action of an energy,

wherein the ink-jet recording ink set comprises;

a black ink; and

at least one color ink,

wherein the black ink comprises;

a self-dispersion type pigment,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant,

a water-soluble organic solvent, and

water;

wherein the black ink has a viscosity of 5 mPa.sec or more at 25°

C.,

wherein the color ink comprises;

a water dispersion which is a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

a water-soluble organic solvent,

water,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant, and

at least one fluorine surfactant,

wherein the color ink has a viscosity of 5 mPa.sec or more at 25°

C.

50. The ink-jet printer according to claim 49, wherein the ink-jet recording head has a nozzle plate which has a surface formed with an ink-repellent coating layer subjected to a eutectic plating.

51. The ink-jet printer according to claim 49, wherein the ink-jet recording head has a nozzle diameter of 30 μ

m or less.

52. A recorded article on which a recording is carried out by a printing method for ejecting an ink by applying an energy to an ink-jet recording ink,

the ink-jet recording ink comprising:

a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane;

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms;

a water-soluble organic solvent;

water;

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant; and

at least one fluorine surfactant,

wherein the ink-jet recording ink has a viscosity of 5 mPa.sec or more at 25°

C.

53. A recorded article on which a recording is carried out by a printing method for ejecting an ink by applying an energy to an ink-jet recording ink set,

the ink-jet recording ink set comprising:

a black ink; and

at least one color ink,

wherein the black ink comprises;

a self-dispersion type pigment,

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant;

a water-soluble organic solvent, and

water,

wherein the black ink has a viscosity of 5 mPa.sec or more at 25°

C.,

wherein the color ink comprises;

a water dispersion which is a polymer emulsion which comprises a polymer fine particle containing a coloring material, the coloring material being insoluble in water or being unlikely to dissolve in the water;

at least one wetting agent, as a first hydroxy compound, selected from the group consisting of glycerin, 1,3-butanediol, triethylene glycol, 1,6-hexanediol, propylene glycol, 1,5-pentanediol, diethylene glycol, dipropylene glycol, trimethylol propane, and trimethylol ethane,

one of;

a polyol, as a second hydroxy compound, having 8 to 11 carbon atoms, and

a glycol ether having 8 to 11 carbon atoms,

a water-soluble organic solvent,

water,

at least one of an anionic surfactant, a nonionic surfactant,

and an amphoteric surfactant, and

at least one fluorine surfactant,

wherein the color ink has a viscosity of 5 mPa.sec or more at 25°

C.