JP2002121442A - Ink for ink-jet recording and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based dispersed ink for ink jet recording having excellent color reproduction and light resistance and provide a method for forming an image having excellent color reproduction and light resistance. SOLUTION: The ink for ink jet recording contains dispersed chelate pigment. The image-forming method uses an ink containing a solid dispersion of chelate pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet ink and an image forming method, and more particularly to an aqueous ink-jet ink having excellent color reproducibility, light fastness and dispersion stability, and an image forming method.

[0002]

2. Description of the Related Art An ink jet recording method is capable of recording a high-definition image with a relatively simple apparatus, and is rapidly developing in various fields. Ink recorded by an ink jet printer can be classified into an aqueous type and an oil type based on a difference in a main solvent composition. Oil-based inks have the advantage of good water resistance of recorded images, but they have problems such as the odor of volatile solvents, bleeding, and safety, and many of the printers currently sold are environmentally friendly. ,
Water-based inks are used for safety and other reasons.

[0003] In ink jet recording, a water-soluble dye or pigment is usually used as a coloring material. In general, inks using dyes are excellent in color reproducibility and excellent in storability of inks, and have been highly evaluated in the market. However, they have problems in image storability such as poor light fastness and bleeding. Further, inks using pigments are excellent in image storability such as light resistance, but tend to be inferior in color reproducibility as compared with dye-based inks. Further, it is difficult to sufficiently reduce the dispersed particle size of the ink in which the pigment is dispersed, which causes problems such as clogging of the nozzles of the printer head and poor storage stability.

[0004] As one of means for improving the light fastness of a dye, a method of coordinating with a metal to form a metal chelate compound is known. For example, JP-A-10-36728 and JP-A-10-36728 disclose the method.
Nos. 0-204351, 10-251572, 10-259331, and 11-61015
Publications describe inks using metal chelate dyes, but all of the dyes described in these publications are compounds having a water-soluble group, and the inks are of a uniform solution type. The image preservability including the property was not sufficient.

[0005]

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an aqueous dispersion ink for ink jet which has excellent color reproducibility and light fastness. A second object of the present invention is to provide an image forming method having excellent color reproducibility and light fastness.

[0006]

The object of the present invention is to provide (1) an ink-jet ink comprising a dispersion of a chelating dye. (2) The inkjet ink according to the above (1), wherein the chelate dye is dispersed in a solvent system having a solubility of the dye of 1% or less. (3) The inkjet ink according to the above (1) or (2), wherein the chelate dye contains a chelate dye coordinated to nickel, copper, chromium, cobalt, zinc, iron or aluminum. (4) The inkjet ink according to any one of (1) to (3), wherein the chelate dye has two or more ligands. (5) The inkjet ink according to any one of (1) to (4), wherein the content of Na ions in the ink is 500 ppm or less. (6) The above-mentioned (1) to (1), wherein the dispersed chelate dye has an average particle size of 0.01 to 0.5 μm.
The ink-jet ink according to any one of (5). (7) The inkjet ink according to any one of the above (1) to (6), which contains 1 to 65% of a water-soluble solvent. (8) The iron content in the ink is from 0.1 ppm to 100
The inkjet ink according to any one of the above (1) to (7), wherein the content is 0 ppm. (9) The inkjet ink according to any one of (1) to (8), wherein the total content of halide ions, carbonate ions, and sulfate ions in the ink is 1000 ppm or less.

(10) The above (1) to (1), wherein the chelate dye is a nickel, copper or cobalt compound.
The ink-jet ink according to any one of (9). (11) An image forming method using an ink containing a solid dispersion of a chelate dye as at least one kind of ink. (12) In an inkjet recording method using at least yellow, magenta, and cyan inks,
The image forming method according to (11), wherein an ink containing a solid dispersion of a chelate dye is used as at least one of magenta and cyan inks. (13) In an ink jet recording method using at least yellow, magenta, cyan, and black inks,
(11) wherein at least one ink contains an ink containing a solid dispersion of a chelate dye.
Or the image forming method according to (12). (14) The method according to the above (13), wherein an ink containing a solid dispersion of a chelate dye is used in at least one of yellow, magenta, and cyan inks, and an ink containing carbon black is used as a black ink. The image forming method as described in the above. (15) The method according to the above (13) or (13), wherein an ink containing a solid dispersion of a chelate dye is used for at least two of yellow, magenta, and cyan inks, and an ink containing carbon black is used for a black ink. The image forming method according to (14). (16) The image forming method as described in any one of (11) to (15) above, wherein an ink containing a solid dispersion of a chelate dye is used as the yellow, magenta, and cyan inks. (17) An image forming method using a magenta ink containing a solid-dispersed chelate dye. Achieved by

Hereinafter, the present invention will be described in detail. In the present invention, a chelate dye refers to a compound in which a dye is coordinated to a metal ion at bidentate or more, but may have another ligand. In the present invention, a ligand refers to an atomic group capable of coordinating to a metal ion, and may or may not have a charge. In the present invention, fine solid dispersion means that fine solid particles dispersed in a dispersion medium are formed by applying energy to solid particles. The aqueous dispersion ink is an ink in which at least a coloring material is dispersed in water and a water-soluble solvent.
The average particle size can be measured by, for example, a laser diffraction method, a laser scattering method, a dynamic laser scattering method, and the like. In the present invention, the Zetasizer 1000 (manufactured by Malvern) based on the dynamic laser scattering method is used. Measured using If the particle size of the dispersed particles is too large, clogging of the nozzles in the printer head is likely to occur or the ink liquid tends to settle. Conversely, if the particle size is too small, aggregation tends to occur and the dispersion stability deteriorates. The average particle size of the dispersed particles is preferably in the range of 0.01 to 0.5 μm.

As a result of examining the dispersion stability of the chelate dye-containing ink liquid, it was found that there is a relationship between the dispersion stability and the iron content in the ink. As a result of the study, the iron content is preferably in the range of 0.1 to 1000 ppm. In the present invention, the iron content refers to the total amount of Fe contained in the ink. As a method for measuring the iron content, an atomic absorption method, an ICP method, or the like can be used. In a chelate dye-dispersed ink, if the amount of Na ions is large, image storability, particularly heat resistance is deteriorated. Therefore, the content of Na ions is desirably 500 ppm or less. When halide ions, carbonate ions, and sulfate ions are present in the ink, the color reproducibility deteriorates. Therefore, the total amount of the above ions is preferably 1000 ppm or less. Known methods can be used for the methods of quantifying halide ions, carbonate ions, and sulfate ions.

The water-soluble solvent used in the present invention includes:
Alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tert-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.), polyhydric alcohols (eg, ethylene glycol, diethylene glycol, Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, etc.), polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether Diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene Glycol monophenyl ether, propylene glycol monophenyl ether, etc.), amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylene Amine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine,
Amides (eg, formamide, N, N-dimethylformamide,
N, N-dimethylacetamide, etc.), heterocycles (eg, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, 1,3
-Dimethyl-2-imidazolidinone, etc.), sulfoxides (eg, dimethyl sulfoxide), sulfones (eg, sulfolane), urea, acetonitrile, acetone and the like.

A specific method for preparing the ink-jet ink of the present invention is described in, for example, JP-A-5-14843.
No. 6, No. 5-295312, No. 7-9754
No. 1, No. 7-82515, No. 7-11858
Reference can be made to the method described in Japanese Patent Publication No. 4 and the like. The viscosity of the above-described inkjet ink at the temperature at the time of flight is preferably 20 mPa · s or less,
More preferably, it is not less than mPa · s and not more than 15 mPa · s. The inkjet ink of the present invention preferably has a surface tension at the time of flight of 15 mN / m or more, more preferably 20 mN / m or more and 80 mN / m or less. In the ink-jet ink of the present invention, a viscosity adjusting agent, a surface tension adjusting agent, a viscosity adjusting agent, Resistance adjuster, film forming agent, dispersant, surfactant,
UV absorbers, antioxidants, anti-fading agents, sunscreen agents, rust preventives and the like can also be added.

The ink-jet ink of the present invention may contain a surfactant, if necessary. Surfactants preferably used in the inkjet ink of the present invention include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, and fatty acid salts, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl allyl. Examples include nonionic surfactants such as ethers, acetylene glycols, and polyoxyethylene / polyoxypropylene block copolymers, and cationic surfactants such as quaternary ammonium salts. In particular, an anionic surfactant and a nonionic surfactant can be preferably used. A dispersant can be used for dispersing the dye. Preferred dispersants for the present invention include, for example, formalin condensate of creosote oil sodium sulfonate (eg, Demol C),
Sodium cresol sulfonate and 2-naphthol-6
-Formalin condensate of sodium sulfonate, formalin condensate of sodium cresol sulfonate, formalin condensate of sodium phenol sulfonate, formalin condensate of sodium β-naphthol sulfonate, formalin condensate of β-sodium naphthalene sulfonate (for example, Demol N), lignin sulfonate (for example, Vanirex RN) and the like. Examples of the polymer dispersant include copolymers of acrylic acid monomers, styrene monomers, α, β-ethylenic unsaturated carboxylic acid aliphatic alcohol ester monomers, maleic acid monomers, and fumaric acid monomers. No. For example, styrene / acrylic acid copolymer, styrene / acrylic acid / acrylic acid ester copolymer, styrene / methacrylic acid copolymer, styrene / methacrylic acid / acrylic acid ester copolymer, styrene / maleic acid copolymer, Styrene / maleic acid / acrylic ester copolymers, polyvinyl alcohol and the like are preferred. The ink-jet ink of the present invention is not particularly limited with respect to the recording method to be used, and can be preferably used as a recording liquid for continuous-type and on-demand type ink-jet printers. On-demand systems include electro-mechanical conversion systems (eg, single cavity,
Double-cavity type, bender type, piston type, shared mode type, shared wall type, etc.), electric-heat conversion method (eg, thermal ink jet type, bubble jet (registered trademark) type, etc.), electrostatic suction method (eg, Specific examples include an electric field control type, a slit jet type, and the like, and a discharge method (for example, a spark jet type). Examples of the chelate dye that can be used in the present invention include a compound represented by the following general formula (1).

General formula (1) M (Dye) _l (A) _{m In} general formula (1), M represents a metal ion and Dye
Represents a dye capable of coordinating with a metal. A represents a ligand other than a dye, 1 represents 1 to 3, and m represents 0, 1, 2, or 3. When m is 0, 1 represents 2 or 3, in which case D
ye may be the same or different. Examples of the metal ion represented by M include metals belonging to Groups I to VIII of the periodic table, for example, Al, Co, Cr, Cu, Fe, M
n, Mo, Ni, Sn, Ti, Pt, Pd, Zr and Z
n ions. Ni, from the color tone, various durability
Particularly preferred are ions of Cu, Cr, Co, Zn, and Fe. More preferably, it is Ni ion. As the dye capable of coordinating with the metal represented by Dye, dyes having various dye structures are used, and conjugated methine dyes, azomethine dyes, and dyes having a coordination group in the azo dye skeleton are preferable. In particular, the following general formulas (2) to
The dye represented by (7) is preferred.

[0014]

Embedded image In the general formulas (2) to (7), X is a group that forms a dye via a conjugated system, and has an atomic group that can coordinate to a monodentate to tridentate metal ion. Examples of the atomic group capable of coordinating with a metal ion include N, S, O bonded to an aromatic ring.
There is a substituent having an atom or a heterocyclic ring.

Examples of the substituent having N, S, and O atoms include primary, secondary, and tertiary amines (for example, amino group, methylamino group, dimethylamino group, diethylamino group, etc.), Examples thereof include a mercapto group, a thioether group, a hydroxy group, a carboxy group, a carbonyl group, and a sulfo group. Examples of the heterocycle include a pyridine ring, a pyrimidine ring, a furan ring, a thiophene ring, a thiazole ring, an imidazole ring, a 3H-pyrrole ring, an oxazole ring, a 3H-pyrrolidine ring, an oxazolidine ring, an imidazolidine ring, and a thiazolidine ring. 3H-indole ring,
Benzoxazole ring, benzimidazole ring, benzthiazole ring, quinoline ring, isoquinoline ring, indolenine ring, barbitur ring, thiobarbitur ring, rhodanine ring, hydantoin ring, pyrazolidinedione ring, pyridinedione ring, pyrazolone ring, And pyrazolotriazole rings. Y represents an atomic group forming a 5- or 6-membered aromatic carbocyclic or heterocyclic ring. Specific examples of the aromatic carbocycle or heterocycle include a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidine ring, a furan ring, a thiophene ring, a thiazole ring, an imidazole ring, a naphthalene ring, a 3H-pyrrole ring, an oxazole ring, and 3H. -Pyrrolidine ring, oxazolidine ring, imidazolidine ring, thiazolidine ring, 3H-indole ring, benzoxazole ring, benzimidazole ring, benzothiazole ring, quinoline ring, isoquinoline ring, indolenine ring, barbitur ring, thiobarbitur ring, Examples include a rhodanine ring, a hydantoin ring, a pyrazolidinedione ring, and a pyridinedione ring.

These rings may further form a condensed ring with another carbon ring (for example, a benzene ring) or a heterocyclic ring (for example, a pyridine ring). Further, these rings may further have a substituent, as these substituents, for example,
Examples include an alkyl group, an aryl group, an acyl group, an amino group, a nitro group, a cyano group, an acylamino group, an alkoxy group, a hydroxy group, an alkoxycarbonyl group, and a halogen atom. Further, these groups may be further substituted. Y may further have a coordinable group.
The ligand other than the dye represented by A may be an anion or a neutral molecule. Examples of the anion include a halide ion, a hydroxy ion, and a nitrate ion.
Inorganic anions such as cyano ion, thiocyanate ion, peroxo ion, azide ion, carbonate ion, sulfate ion, tetrafluoroboron ion, acetic acid, oxalic acid, maleic acid, succinic acid, acetylacetone, salicylaldehyde, glycine, ethylenediamine diacetic acid, Ethylenediaminetetraacetic acid, benzoic acid, p-toluenesulfonic acid, phenol, phthalic acid, picolinic acid, thiophenol, anion of dithiolbenzene and the anion of a derivative thereof, and neutral molecules such as ammonia, water, Triphenylphosphine, 1,3
-Propanediamine, 2,2'-bipyridine, 1,10
- phenanthroline, glycinamide, diethylenetriamine, 2,2 ', 2 "-. Terpyridyl, triethylenetetramine, etc. ethylenediamine general formula (2) ~ (4), R 1, R 2, R 3 is a hydrogen atom , A halogen atom or a monovalent substituent;
Or 2 is represented. Hereinafter, specific examples of the dye capable of coordinating with the metal represented by Dye will be described, but the present invention is not limited thereto.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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Hereinafter, specific examples of the ligand other than the dye represented by A will be shown, but the present invention is not limited thereto.

[0025]

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[0026]

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[0027]

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[0028]

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The following are specific examples of chelating dyes used in the present invention, but the present invention is not limited thereto. Illustrative number Chelate dye composition Y-1 Ni (D-7) ₁ (A-27) ₂ Y-2 Ni (D-8) ₁ (A-32) ₂ Y-3 Ni (D-4) ₁ (A- _{26) 2 Y-4 Ni (} D-9) 1 (A-8) 2 Y-5 Ni (D-3) 2 (A-14) 1 Y-6 Ni (D-8) 1 (A-30) _{2 Y-7 Ni (D-} 7) 2 (A-1) 2 Y-8 Ni (D-7) 2 (A-2) 2 Y-9 Ni (D-1) 2 (A-10) 2 Y _{-10 Cu (D-7) 1} (A-31) 2 Y-11 Co (D-8) 1 (A-27) 2 M-1 Ni (D-26) 1 (A-32) 2 M-2 _{Ni (D-25) 1 (} A-29) 2 M-3 Ni (D-18) 2 (A-18) 1 M-4 Ni (D-20) 2 (A-11) 1 M-5 Ni ( _{D-23) 2 M-6} Ni (D-30) 2 (A-1) 2 M-7 Ni (D-31) 1 (A-32) 2 M-8 Ni (D-31) 2 (A-1) ₂ M-9 Ni (D-32) ₁ (A-27) ₂ M-10 Ni (D-33) ₂ (A-3) ₂ M-11 Ni (D-15) ₂ (A _{-14) 1 M-12 Co (} D-17) 3 M-13 Cu (D-26) 1 (A-31) 2 M-14 Ni (D-28) 1 (A-22) 1 M-15 Ni (D-27) ₁ (A-18) ₁ M-16 Ni (D-25) ₁ (A-22) ₁ M-17 Co (D-29) ₁ (A-19) ₁ C-1 Ni (D -51) ₁ (A-18) ₁ C-2 Ni (D-50) ₂ (A-30) ₂ C-3 Ni (D-54) ₂ (A-2) ₂ C-4 Ni (D-55 ) ₁ (A-32) ₂ C-5 Ni (D-38) ₁ (A-16) ₁ C-6 Ni (D-40) ₂ C-7 Ni (D-42) ₂ (A-5) ₂ C-8 Ni (D-49 ) 2 (A-14) 1 C-9 Cu (D-51) 1 (A-4) 2 C-10 Ni (D-53) 2 (A-23) ₁

The above chelate dye composition is represented by the general formula (1): M (Dye) ₁ (A) _m M: metal atom Dye: an example compound number of a dye capable of coordinating with a metal 1: the number of Dye A : Exemplified compound number of ligand other than dye m: Number of A Based on the notation, when the ionizable group in each molecule dissociates to form an ionic bond with a metal, examples of each element It shall show a structure from which a proton has been removed from the compound. The chelated black dye can be obtained by appropriately mixing a chelate dye such as yellow, magenta, and cyan.

[0031]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

[Synthesis of Chelate Dye] Synthesis of Exemplified Compound Y-7 D-7 was heated under reflux for 1 hour in methanol with nickel chloride hexahydrate, allowed to cool, and the resulting crystals were collected by filtration.
After washing with a small amount of methanol, Exemplified Compound Y-7 was obtained.
Other chelating dyes were synthesized in the same manner.

Example 1 [Preparation of Dispersion] (Dispersion 1) Exemplified Compound Y-7 20 parts Joncryl 70 (manufactured by Johnson Polymer) 10 parts Nonipol 700 (manufactured by Sanyo Chemical) 10 parts Glycerin 10 parts Ethylene glycol 20 parts 30 parts of ion-exchanged water The above composition was filled with 0.3 mm zirconia beads at a volume ratio of 90%, and the system zeta LMZ-2 (trade name)
(Ashizawa), and coarse particles were removed by centrifugation to obtain a dispersion having an average particle diameter of 120 nm. (Dispersions 2 to 6, 8, and 9) Dispersions 2 to 6 were prepared in the same manner as Dispersion 1 except that the composition of the dispersion was as described below.

Dispersion 2 Exemplified Compound M-1 20 parts Joncryl 65 (manufactured by Johnson Polymer) 10 parts Surfynol 465 5 parts Glycerin 10 parts Ethylene glycol 20 parts Deionized water 35 parts Dispersion 3 Exemplified Compound C-1 20 parts Emulgen 985 (Kao) 20 parts Glycerin 10 parts Ethylene glycol 20 parts Ion-exchanged water 35 parts

Dispersion 4 Exemplified Compound C-2 27 parts Joncryl 61J (manufactured by Johnson Polymer) 13 parts Orfin 1010 (manufactured by Nissin Chemical) 5 parts Triethylene glycol 17 parts Deionized water 38 parts Dispersion 5 Exemplified Compound M- 2 32 parts Demol C (Kao) 5 parts DES 3 parts Ethylene glycol 16 parts Triethylene glycol monobutyl ether 16 parts Defoamer 5 parts Ion-exchanged water 28 parts Dispersion 6 Exemplified compound C-3 23 parts John Krill 70 (Johnson Johnson) 24 parts Levenol WX (Kao) 15 parts Triethylene glycol 12 parts Diethylene glycol monomethyl ether 12 parts Ion-exchanged water 14 parts

(Dispersion 7) A dispersion 7 was prepared by changing the composition and conditions of the dispersion as described below. Dispersion 7 Exemplified Compound Y-4 20 parts Nonipol 700 (manufactured by Sanyo Chemical) 10 parts Ion-exchanged water 70 parts In the same manner as Dispersion 1 using a container coated with Teflon (registered trademark) using the above composition instead of a stainless steel container Dispersion was performed using System Zeta LMZ-2 (manufactured by Ashizawa Co., Ltd.) filled with 0.3 mm zirconia beads at a volume ratio of 90%, and coarse particles were removed by centrifugation.
A 120 nm dispersion was obtained. (Dispersions 8 and 9) Dispersions 8 and 9 were prepared in the same manner as Dispersion 1 except that the composition of the dispersion was as described below. Dispersion 8 Exemplified Compound C-3 20 parts Joncryl 70 15 parts Sodium dodecyl sulfate 3 parts Iron (III) bromide 5 parts Diethylene glycol monomethyl ether 20 parts Ion-exchanged water 37 parts Dispersion 9 (comparative) D-26 20 parts John Krill 61J (manufactured by Johnson Polymer) 17 parts DES 7 parts Ethylene glycol 20 parts Deionized water 46 parts

[Ink Preparation] Using the above dispersions 1 to 9,
An ink liquid having the following composition was prepared. Ink 1 Dispersion 1 20 parts Ethylene glycol 8 parts Glycerin 3 parts Nonipol 700 3 parts Proxel GX-L 0.2 parts Ion exchange water 65 parts Ink 2 Dispersion liquid 2 13 parts Surfynol 465 4 parts Ethylene glycol 23 parts Glycerin 3 parts Proxel GX-L 0.2 parts Deionized water 57 parts

Ink 3 Dispersion 3 14 parts Emulgen 985 5 parts Ethylene glycol 38 parts Glycerin 2 parts Proxel GX-L 2 parts Deionized water 41 parts Ink 4 Dispersion 4 12 parts Orphin 1010 4 parts Triethylene glycol 24 parts Proxel GX -L 0.2 parts ion exchange water 60 parts

Ink 5 Dispersion 5 17 parts DES 2 parts Ethylene glycol 13 parts Triethylene glycol monobutyl ether 13 parts Proxel GX-L 0.2 parts Deionized water 55 parts Ink 6 Dispersion 6 5 parts Levenol WX 3 parts Triethylene Glycol 12 parts Diethylene glycol monomethyl ether 6 parts NaCl 0.2 parts Proxel GX-L 0.2 parts Deionized water 74 parts

Ink 7 Dispersion 7 20 parts Nonipol 700 1 part Ethylene glycol 19 parts Proxel GXL 0.2 parts Ion exchange water 60 parts Ink 8 Dispersion 8 10 parts Ethylene glycol 30 parts Emulgen 985 5 parts Proxel GX-L 0. 2 parts ion exchange water 55 parts

Ink 9 (comparative) Dispersion 9 7 parts Ethylene glycol 23 parts DES 7 parts Proxel GX-L 0.2 parts Ion-exchanged water 63 parts Ink 10 (comparative) Comparative dye M 4 parts ethylene glycol 25 parts Triethylene Glycol monobutyl ether 13 parts DES 5 parts Proxel GX-L 0.2 parts Deionized water 53 parts

<< Evaluation of Ink >><DispersionStability> The prepared ink liquid was stored at 60 ° C. for 2 weeks, and the rate of change of the average particle diameter was measured. Particle size change rate ：: 5% or less ：: 20% or less ：: 50% or less ×: 50% or more <Color reproducibility> The prepared ink was subjected to Epson MJ-80.
It was printed on Konica Photo Jet Paper QP with a 0C printer and evaluated on a 4-point scale. <Emission stability> Continuous discharge was performed by the above printer, and blurring of printing and occurrence of nozzle missing were evaluated in four steps.

<Image preservability> The residual ratio after 170 hours irradiation with a 70000 lux xenon fade meter was measured.
It was evaluated on a 4-point scale based on the following criteria. ：: Residual rate of 90% or more ：: Residual rate of 80 to 90% △: Residual rate of 50 to 80% ×: Residual rate of 50% or less <Heat resistance> Printed sample was stored at 80 ° C. and 20% RH for 10 days for density. The change (ΔD) was evaluated on a four-point scale. ◎: ΔD <0.02 ○: 0.02 ≦ ΔD <0.05 Δ: 0.05 ≦ ΔD <0.1 ×: 0.1 ≦ ΔD The results are shown in Table 1.

[0044]

[Table 1]

Example 2 Ink 1 (yellow) and ink 2 prepared in Example 1
(Magenta), Ink 3 (cyan), and Sample A (invention) printed in multicolor using black ink using carbon black, and comparative dyes Y, M, C, and carbon black shown below. When the sample B printed with the ink was compared, a clear image was obtained in both cases immediately after the printing. However, when the sample B was stored in a place exposed to light, the discoloration was intense. Almost no fading was observed under the same conditions. Comparative dye

[0046]

Embedded image As described above, according to the present invention, an ink having excellent dispersion stability, emission properties, and heat resistance, and excellent color reproducibility and light resistance was obtained.

[0047]

According to the present invention, it is possible to obtain an aqueous dispersion ink for inkjet which is excellent in dispersion stability, emission properties and heat resistance, and has good color reproducibility and light resistance.

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Claims (17)

[Claims] 1. An ink-jet ink comprising a dispersion of a chelate dye. 2. The ink-jet ink according to claim 1, wherein the chelate dye is dispersed in a solvent system having a solubility of the dye of 1% or less. 3. The chelating dye is nickel, copper, chromium,
The inkjet ink according to claim 1, further comprising a chelate dye coordinated to cobalt, zinc, iron, or aluminum. 4. The ink-jet ink according to claim 1, wherein the chelate dye has two or more ligands. 5. The ink according to claim 5, wherein the content of Na ions in the ink is 500 p.
The ink for inkjet according to any one of claims 1 to 4, wherein the viscosity is not more than pm. 6. The ink-jet ink according to claim 1, wherein the dispersed chelate dye has an average particle diameter of 0.01 to 0.5 μm. 7. The ink-jet ink according to claim 1, comprising 1 to 65% of a water-soluble solvent. 8. The ink according to claim 1, wherein the iron content in the ink is 0.1 ppm to 1000 ppm.
The inkjet ink according to any one of the above. 9. The inkjet ink according to claim 1, wherein the total content of halide ions, carbonate ions, and sulfate ions in the ink is 1000 ppm or less. 10. The ink-jet ink according to claim 1, wherein the chelating dye is a nickel, copper or cobalt compound. 11. An image forming method, wherein an ink containing a solid dispersion of a chelate dye is used as at least one of the inks. 12. An ink jet recording method using at least yellow, magenta and cyan inks, wherein at least one of the yellow, magenta and cyan inks uses an ink containing a solid dispersion of a chelate dye. 2. The image forming method according to 1., 13. The ink-jet recording method using at least yellow, magenta, cyan, and black inks, wherein at least one ink contains a solid dispersion of a chelate dye. Image forming method. 14. An ink containing a solid dispersion of a chelate dye in at least one of yellow, magenta and cyan inks, and an ink containing carbon black as a black ink.
2. The image forming method according to 1., 15. An ink containing a solid dispersion of a chelating dye in at least two of yellow, magenta and cyan inks, and an ink containing carbon black as a black ink.
Or the image forming method according to 14. 16. The image forming method according to claim 11, wherein an ink containing a solid dispersion of a chelate dye is used as the yellow, magenta, and cyan inks. 17. An image forming method using a magenta ink containing a solid-dispersed chelate dye.