JP2001011347A - Water-based ink for inkjet recording - Google Patents

Abstract

(57) [Problem] To provide a water-based ink for ink-jet recording which has good coloring properties, high print density, and excellent water resistance and light resistance. A dye A capable of coordinating with a metal ion in a bidentate or more position
And an aqueous dispersion of polymer particles containing a coordinator C of the dye A and a compound B containing a metal ion capable of coordination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water-based ink for ink-jet recording. More specifically, the present invention relates to a water-based ink for inkjet recording having excellent light fastness and water fastness.

[0002]

2. Description of the Related Art An ink jet recording system is a recording system in which ink droplets are directly ejected from a very fine nozzle onto a recording member and adhered to obtain characters and images. This method is
In addition to the advantages that the device used has low noise and good operability, it has the advantages of being easy to colorize and of being able to use plain paper as a recording member, and has recently been widely used in inkjet printers. .

[0003] In the ink used in the ink jet printer, a water-soluble dye and a polyhydric alcohol are usually used in order to prevent the ink from being clogged in the nozzles. However, this ink has the disadvantage that the water-soluble dye has poor water resistance.

[0004] In order to improve the water resistance of an ink jet recording ink, a pigment is used in the ink (Japanese Patent Laid-Open No.
No. 28776), use of a non-aqueous liquid medium (Japanese Patent Application Laid-Open No. 4-261478), use of a dye having excellent water resistance (U.S. Pat. No. 4,963,189) have been proposed. However, these inks have
There are drawbacks such as a decrease in print density and poor light resistance.

As a method for improving the light fastness of a dye, a method of coordinating a dye with a metal ion is generally known. This method is used for the production of an ink jet dye, and the dye and the metal ion are used in the same ink. (Japanese Patent Laid-Open Publication No. 8-156399). However, this method has a drawback that coordination of a dye with a metal ion lowers its solubility in water, so that the dye may precipitate and clog the ink jet nozzle.

Therefore, the dye and the metal ion are not contained in the same ink but are contained in different inks respectively, or one of the dye and the metal ion is contained in the ink,
A method has been proposed in which the other is contained in paper and the two are mixed on paper when printing. However, this method has the disadvantage of requiring two types of ink,
It has the disadvantage that it cannot be applied to plain paper.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-based ink for ink-jet recording which has good coloring properties, high printing density, and excellent water resistance and light resistance.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a dye A capable of coordinating with a metal ion in a bidentate or more (hereinafter simply referred to as "dye A") and a compound containing a metal ion capable of coordinating with the dye A The present invention relates to a water-based ink for ink-jet recording comprising a water dispersion of polymer particles containing a coordinator C (hereinafter, simply referred to as “coordinator C”) with B (hereinafter, simply referred to as “compound B”).

[0009]

DETAILED DESCRIPTION OF THE INVENTION As the dye A, a dye having two or more functional groups (for example, an OH group, a COOH group, a heteroheterocycle, etc.) which can be a ligand can be used. A typical example is the formula (II):

[0010]

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A dye represented by the formula (III):

[0012]

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And the like. These can be used alone or as a mixture of two or more. Among these dyes A, those that can be dissolved in an organic solvent are preferable, and dyes that can be dissolved in an organic solvent and coordinate with a metal ion in a tridentate are more preferable.

As the compound B, a salt of a metal ion with an inorganic anion or an organic anion, a coordination metal ion complex and the like can be mentioned. Specific examples of the compound B include a compound represented by the formula (V): [M ^{a +} (Q ^b− ) _x (V) _y ] (W ^c ) _z (V) (where M is a metal atom, and Q is an anion coordination) , V is a neutral ligand, W is a counter ion; a is an integer of 1 to 5, b is 1
An integer of ６6, c is a number of −２2 to 2, excluding 0, x, y and z
Each represents an integer of 0 to 6), and these can be used alone or in combination of two or more.

The metal ions represented by Ma ⁺ include copper (I, II), silver (I), gold (III), zinc (II), aluminum (III), gallium (III), silicon (IV), Titanium (I
V), zirconium (IV), chromium (III), manganese (I
I), iron (II, III), ruthenium (II, III, IV), cobalt (II, III), rhodium (II, III), nickel (I
I), palladium (II), platinum (II, IV) and the like. Among these, when a bidentate dye is used, a transition metal ion capable of coordination at a tetradentate or hexadentate is preferred, and when a dye at a tridentate coordinate is used, a hexadentate dye is used. Transition metal ions that can be coordinated are preferred. Particularly preferred transition metal ions are zinc (II), nickel (II), cobalt (II, III), copper (II), rhodium (II, III), ruthenium (II, III), palladium (II) and platinum ( II, IV).

The ligands of the anion represented by Q ^b- include halide ions (fluoride, chloride, bromide, iodide, etc.), nitrate ions, sulfate ions,
Carbonate ion, carboxylate ion, hydroxy ion, cyano ion, peroxy ion, acetylacetonate ion and its derivative, phenolate ion of salicylaldehyde and its derivative, glycinate ion, thiocyanate ion, azide ion, oxalate ion, Examples thereof include a sulfate ion and an oxalite ion.

The neutral ligand represented by V is ammonia, water, triphenylphosphine, ethylenediamine,
1,3-propanediamine, 2,2 ′, 2 ″ -bipyridine, 1,10-phenanthroline, glycinamide, diethylenetriamine, 2,2 ′, 2 ″ -terpyridine, triethylenetetramine and the like.

The counter ion represented by W ^c becomes an anion or a cation as necessary to make the charge neutral. Examples of such anions include halide ions, sulfite ions, sulfate ions, alkyl or aryl sulfonate ions, nitrate ions, nitrite ions, perchlorate ions, carboxylate (acetate, trifluoroacetate, stearylate, etc.), salicinate, Benzoate, hexafluorophosphate, tetrafluoroborate and the like can be mentioned, and cations include lithium (I), sodium (I), potassium (I), ammonium and phosphonium.

Specific examples of the compound B include zinc chloride, zinc sulfate, zinc nitrate, zinc acetate, nickel (II) chloride, nickel (II) acetate, nickel (II) stearate, bis (2,4-pentanedioate) Nato) diaqua nickel (I
I), bis (3-methoxycarbonyl-2,4-tetodecandionato) nickel (II), tris (glycinamide) nickel (II) tetraphenylborate, cobalt acetate (II), cobalt thiocyanate (II) ), Hexaamminecobalt (III) chloride, cis-dichlorotetraamminecobalt (III) chloride, ammonium tetranitrodiaminecobaltate (III), copper (II) sulfate, copper (II) tetrafluoroborate, bis (ethylenediamine) ) Copper (I
I) sulfate, rhodium (II) chloride, rhodium sulfate (I
I), hexaamminerhodium (III) chloride, potassium hexacyanorhodate (III), hexaammineruthenium (III) bromide, potassium hexacyanoruthenium (II), ammonium tetrachloropalladate (II), tetraamminepalladium (II) Chloride, tetraammineplatinum (II) chloride, hexaammineplatinum (IV) chloride, tris (ethylenediamine) platinum (IV) chloride,
Formula (IV):

[0020]

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And the like. Among these, those that can be dissolved in an organic solvent, particularly the compound represented by the formula (IV), are preferable.

The amount of the dye A per 100 parts by weight of the polymer is from 50 to 300 parts by weight, preferably from 100 to 150 parts by weight, from the viewpoint of achieving a sufficient print density and a sufficient coloring property.
Desirably, parts by weight are used.

The content of compound B in the polymer is
From the viewpoint of exhibiting sufficient light resistance, the stoichiometric amount required for coordination with Dye A is preferably 0.8 to 10 times, more preferably 1 to 1.5 times.

The use of the dye A and the compound B as raw materials and the fact that both are not coordinated in advance eliminates the need for a complicated step of pre-coordinating the dye A and the compound B. And the fact that the desired dye A and compound B cannot be combined according to the desired physical properties as in the case of a dye in which both are coordinated in advance (hereinafter referred to as dye D). ,preferable.

The polymer is preferably obtained by copolymerizing a monomer composition containing a polymerizable unsaturated monomer having a salt-forming group and a monomer copolymerizable with the monomer. The polymer is preferably one that can contain at least a part of Dye A in the polymer. The polymer preferably has a salt-forming group from the viewpoint of obtaining a stable aqueous dispersion. Further, formula (I): X (Y) _n Si (R ¹ ) _3-m (Z) _m (I) (wherein X is a polymerizable unsaturated group; Y is a divalent linking group;
R ¹ may be the same or different and each represents a hydrogen atom, a lower alkyl group, an aryl group or an alkoxy group;
Z is essentially non-reactive under copolymerization conditions and is a residue of a monovalent siloxane polymer having a number average molecular weight of 300 or more; m is an integer of 1 to 3; n represents 0 or 1) At least one selected from the group consisting of a silicone macromer represented and a (meth) acrylamide monomer having no salt-forming group, a polymerizable unsaturated monomer having a salt-forming group, and a copolymerizable with these monomers. A polymer obtained by copolymerizing a monomer composition containing a monomer is particularly preferred.

The silicone macromer of the formula (I)
In the above, X represents a copolymerizable unsaturated group. Examples
As the CH_Two= CH-, CH_Two= C (CH_Three)-And the like.
It is. Y represents a divalent linking group, specifically, -COO-
Group, -COOC_dH_2dA group (d represents an integer of 1 to 5),
And an phenylene group. Among them, -COOC _ThreeH
₆ -Groups are preferred.

R ¹ represents a hydrogen atom; a lower alkyl group having 1 to 4 carbon atoms such as a methyl group or an ethyl group; an aryl group such as a phenyl group; an alkoxy group having 1 to 4 carbon atoms such as a methoxy group. Of these, a methyl group is preferred.

Z is a residue of a monovalent siloxane polymer having a number average molecular weight of 300 or more. Z is preferably a residue of a dimethylsiloxane polymer having a number average molecular weight of 500 to 5,000.

M is an integer of 1 to 3, preferably 1. n is 0 or 1, but is preferably 1.

Examples of silicone macromers include the formula:

[0031]

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Wherein R ¹ is the same as above, R ² is a hydrogen atom or a methyl group, and E is a group represented by the formula:

[0033]

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(Wherein R ¹ is as defined above; e is 5 to 65)
And e is the same as defined above). Among these compounds, the compound represented by the formula (A) is preferable, and particularly, the compound represented by the formula (A1):

[0035]

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(Wherein, R ¹ is the same as above, and f represents a number having a number average molecular weight of 500 to 2,000).

(Meth) acrylamide-based monomer having no salt-forming group [refers to acrylamide-based monomer or methacrylamide-based monomer. The same applies hereinafter), for example, monomers described in JP-A-10-279873. Among them, N, N-dimethylacrylamide and Nt-butylacrylamide are preferred.

The silicone macromer and the (meth) acrylamide monomer can be used alone or as a mixture.

Examples of the polymerizable unsaturated monomer having a salt-forming group include a cationic monomer and an anionic monomer having a salt-forming group. Examples of the cationic monomer and the anionic monomer include monomers described in JP-A-10-279873.

Examples of the cationic monomer having a salt-forming group include unsaturated tertiary amine-containing monomers, unsaturated ammonium salt-containing monomers, and the like. Preferred representative examples thereof include N, N-diethylaminoethyl acrylate, N- (N ′, N′-dimethylaminoethyl) acrylamide, N- (N ′, N′-dimethylaminoethyl) methacrylamide and the like.

Examples of the anionic monomer having a salt-forming group include unsaturated carboxylic acid monomers, unsaturated sulfonic acid monomers, unsaturated phosphoric acid monomers and the like. Preferred representative examples thereof include acrylic acid and methacrylic acid.

The monomers copolymerizable with the above-mentioned monomers include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and t-acrylate.
Acrylates such as -butyl, isobutyl acrylate, n-amyl acrylate, n-hexyl acrylate, n-octyl acrylate, dodecyl acrylate; methyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, methacryl Methacrylates such as t-butyl acrylate, isobutyl methacrylate, n-amyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and polyethylene glycol methacrylate; styrenes such as styrene, vinyl toluene, and 2-methylstyrene Monomers; hydroxyl-containing acrylates and methacrylates such as 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate; vinyl-based macromers composed of vinyl-based polymers having a polymerizable functional group at one end Polyester macromer composed of polyester having a polymerizable functional group at one end, polyurethane macromer composed of polyurethane having a polymerizable functional group at one end, polyalkyl ether macromer composed of a polyalkyl ether having a polymerizable functional group at one end, etc. However, the present invention is not limited to only such examples.

The content of at least one selected from the group consisting of the silicone macromer and the (meth) acrylamide monomer having no salt-forming group in the monomer composition is 1
-40% by weight, preferably 2-20% by weight, the content of the polymerizable unsaturated monomer having a salt-forming group is 2-40% by weight, preferably 5-20% by weight, and monomers copolymerizable with these monomers. Is desirably 60 to 90% by weight, preferably 70 to 85% by weight.

In the monomer composition, if necessary,
A polymerization chain transfer agent may be contained.

The polymer can be obtained by copolymerizing the monomer composition by a known polymerization method such as a bulk polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. Among these methods, a solution polymerization method is particularly preferable.

Solvents used when employing the solution polymerization method include aliphatic alcohols such as ethanol and propanol; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and aromatic solvents such as benzene and toluene. And the like. These may be used alone or in 2
A mixture of more than one species can be used.

The weight average molecular weight of the polymer was 3,000 to 80,000 as measured by gel permeation chromatography under the conditions shown in Production Examples 1 and 2 described below.
0, preferably 3000 to 50000, from the viewpoint of preventing scorching of the printer head and improving the durability of the ink after printing.

Further, the polymer preferably has a Tg (glass transition point) measured by DSC (differential scanning calorimeter) of 20 ° C. or higher in an ink jet recording system using a piezoelectric element. In the ink jet recording method, the temperature is preferably 30 ° C. or higher, and particularly, in both the piezoelectric element method and the thermal energy method,
It is preferable that it is -150 degreeC.

In order to prepare an aqueous dispersion of polymer particles containing the coordination C of the dye A and the compound B, the dye A, the compound B and the polymer are first dissolved in an organic solvent. in this case,
Dye A 10 to 30 parts by weight, preferably 15 to 25 parts by weight, compound B 10 to 30 parts by weight, based on 100 parts by weight of the organic solvent.
Parts by weight, preferably 15 to 25 parts by weight, polymer 3
It is desirable to use 0 to 100 parts by weight, preferably 35 to 50 parts by weight, from the viewpoint of the stability of the obtained water-based ink. In this case, as the organic solvent, a water-insoluble organic solvent is preferable from the viewpoint of the stability of the emulsion at the time of emulsification. When the dye A is used instead of the dye A and the compound B as raw materials, the amount of the dye D is 20 to 60 parts by weight based on 100 parts by weight of the organic solvent from the viewpoint of the stability of the obtained aqueous ink. Parts, preferably 30 to 50 parts by weight.

As the water-insoluble organic solvent, those having a solubility in water at 25 ° C. of 3% by weight or less are preferred from the viewpoint of preventing crystallization of Dye A and Dye. Examples include aromatic solvents such as benzene and toluene; aliphatic solvents such as heptane, hexane and cyclohexane; halogens such as methylene chloride, 1,1,1-trichloroethane, chloroform, carbon tetrachloride and 1,2-dichloroethane. And chlorinated aliphatic solvents.

Next, water is added to an organic solvent solution containing the dye A, the compound B and the polymer. When the polymer has a salt-forming group, a neutralizing agent and water are added to ionize the salt-forming group in the polymer. After adding water or a neutralizing agent and water, the mixture is emulsified. At this time, a surfactant may be added as needed.

As the neutralizing agent, an acid or a base may be selected according to the type of the salt-forming group. Examples of the acid include inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid, propionic acid, lactic acid, succinic acid, and gluconic acid. Also, as the base,
Examples include tertiary amines such as trimethylamine, triethylamine, monomethanolamine, diethanolamine, and triethanolamine, ammonia, sodium hydroxide, and potassium hydroxide.

The degree of neutralization is not particularly limited. Normally, it is desirable to neutralize the aqueous ink so that the liquidity is weakly basic to neutral. The amount of water is preferably about 150 to 1000 parts by weight based on 100 parts by weight of the organic solvent.

The surfactant is not particularly limited. Examples include alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkane or olefin sulfonates, alkyl sulfates, polyoxyethylene alkyl or aryl ether sulfates, alkyl phosphates, alkyl diphenyl ether disulfonates, Anionic surfactants such as ether carboxylate, alkyl sulfosuccinate, α-sulfo fatty acid ester, fatty acid salt, condensate of higher fatty acid and amino acid, naphthenate; aliphatic amine salt, quaternary ammonium salt;
Cationic surfactants such as sulfonium salts and phosphonium salts; nonionic surfactants such as polyoxyethylene alkyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, and alkyl (poly) glycoside And the like, and these can be used alone or in combination of two or more.

Next, after emulsification as described above, the organic solvent is removed from the emulsion, and a predetermined amount of water is removed as necessary, whereby an aqueous ink having a predetermined solid content concentration is obtained.

The emulsification is preferably carried out such that the average particle size of the polymer particles before removing the organic solvent is 100 to 500 nm. Examples of the emulsifier that can be used at the time of emulsification include an ultrasonic emulsifier, a high-pressure homogenizer, and a film emulsifier.

The removal of the organic solvent is preferably carried out by evaporation at a temperature of from 20 to 100 ° C., preferably at a temperature of from 30 to 60 ° C. At this time, it is preferable to remove the organic solvent to such an extent that the surface tension of the water-based ink does not decrease and bleeding does not increase.

The average particle size of the polymer particles contained in the aqueous ink thus obtained is from 10 to 500 nm from the viewpoint of avoiding the occurrence of bleeding of the ink and improving the dispersion stability of the polymer in the aqueous ink. Preferably, it is more preferably 20 to 200 nm.

Dye A and compound B are contained in the polymer particles.
And the coordinator C is included. The fact that the dye A is contained in the polymer particles can be confirmed by the fact that the colored insoluble dye A crystals substantially do not exist in the aqueous ink medium. Further, since the spectral characteristics of the water-based ink are equivalent to those of the dye solution dissolved in the organic solvent, it can be confirmed that the coloring by the dye A is based on the dye A contained in the polymer particles. .

From the viewpoint of improving the print density and preventing clogging at the nozzle tip of the ink jet printer, the solid content of the polymer in the water-based ink is preferably 1%.
It is desirable that the content be 30 to 30% by weight, preferably 2 to 15% by weight, more preferably 2 to 10% by weight.

The water-based ink of the present invention contains a wetting agent such as polyhydric alcohols and amino acids, a dispersing agent, a defoaming agent such as silicone, and a surface tension adjusting agent such as a cationic, anionic or nonionic surfactant. Various additives such as an agent, a fungicide such as chloromethylphenol, a chelating agent such as EDTA, and an oxygen absorbent such as sulfite can also be added.

The viscosity of the water-based ink at 20 ° C. is preferably from 0.5 to 5 mPa · s, and more preferably from 1 to 3 mPa · s, from the viewpoint of ejection stability particularly when used in an ink jet printer. preferable. The surface tension of the aqueous ink at 20 ° C. is preferably from 20 to 50 mN / m, more preferably from 30 to 45 mN / m, from the viewpoint of permeability to the printing object.

[0063]

EXAMPLES Production Examples 1-2 In a reaction vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen gas introduction pipe, 20 parts by weight of methyl ethyl ketone as a solvent, a monomer and a polymerization chain transfer agent as shown in Table 1 were used. The monomers described in “Initial Charged Monomers” and a polymerization chain transfer agent (mercaptoethanol) were charged, and nitrogen gas replacement was sufficiently performed.

On the other hand, in the dropping funnel, the monomers described in “Dropping monomers” in Table 1 and a polymerization chain transfer agent (mercaptoethanol), 60 parts by weight of methyl ethyl ketone, and 2,2′-azobis (2,4-dimethylvalero) Nitrile) was charged after 0.2 parts by weight was sufficiently replaced with nitrogen gas.

In a nitrogen gas atmosphere, the temperature of the mixed solution in the reaction vessel was raised to 65 ° C. while stirring, and the mixed solution in the dropping funnel was gradually added dropwise over 3 hours. 2 after the end of dripping
After a lapse of time, 0.1 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) was added to methyl ethyl ketone 5
Add the solution dissolved in parts by weight, and further at 65 ° C. for 2 hours,
By aging at 70 ° C. for 2 hours, a polymer solution was obtained.

The obtained polymer solution was placed under reduced pressure at 105
The polymer was isolated by heating at 2 ° C. for 2 hours to remove the solvent.

Next, the weight average molecular weight of the obtained polymer was measured by gel permeation chromatography using 0.5% tetrahydrofuran solution using polystyrene as a standard substance. Table 1 shows the results.

The names and abbreviations of the monomers shown in Table 1 mean the following. t-BMA: Tertiary butyl methacrylate HEMA: 2-hydroxyethyl methacrylate PEGMA: Polyethylene glycol methacrylate MAA: Methacrylic acid LMA: Lauryl methacrylate St: Styrene Si macromer: Silicone macromer [Chisso Corporation
Product number: FM-0711]

[0069]

[Table 1]

Examples 1 and 2 and Comparative Example 1 50 g of the polymer obtained in Production Examples 1 and 2, 50 g of the dye shown in Table 2, and the above stoichiometric amount required for coordination with the dye A compound (compound B) represented by (IV) was added to 200 g of methyl ethyl ketone and completely dissolved,
Under stirring, a neutralizing agent shown in Table 2 was added in an amount to neutralize the salt-forming groups by 100% to neutralize the salt-forming groups in the copolymer, and 1500 g of ion-exchanged water was added thereto. Emulsifying with a fluidizer M110EH (trade name, manufactured by Mizuho Industry Co., Ltd.), then removing methyl ethyl ketone at 60 ° C. under reduced pressure, further concentrating by removing a part of water, and polymer containing coordinator C An aqueous dispersion of the particles was obtained.

Next, 80 g of the obtained aqueous dispersion, 10 g of diethylene glycol and 10 g of ion-exchanged water were mixed,
The resulting dispersion was filtered through a filter having a pore size of 0.2 μm to remove dust and coarse particles, thereby obtaining an aqueous ink.

As physical properties of the obtained water-based ink, print density, light fastness, water fastness and average particle diameter were measured according to the following methods. Table 2 shows the results.

(1) Print Density Printing was performed using a bubble jet printer (Canon Co., Ltd.).
And model number: BJC-430), and solid printing is performed on recycled paper for PPC (manufactured by Nippon Kaishi Paper Co., Ltd.) at 25 ° C.
, And the optical density was measured with a Macbeth densitometer (manufactured by Macbeth, product number: RD918).

(2) Light resistance The same PP as described above was used using the bubble jet printer.
Solid printing was performed on the recycled paper for C and the sample was dried naturally at 25 ° C. for 24 hours to obtain a sample. The print density (before irradiation) of a specific print portion of the sample was measured using the Macbeth densitometer.

Next, the sample was irradiated with ultraviolet rays of 10,000 kJ / m ² using a low temperature cycle xenon long life fade meter (manufactured by Suga Test Instruments Co., Ltd.). afterwards,
In the same manner as described above, the print density after irradiation of the same specific printing spot as before irradiation is measured, and the light resistance is calculated by the formula: [light resistance (%)] = [print density after irradiation] / [print density before irradiation] ] × 100 and evaluated based on the following evaluation criteria.

[Evaluation Criteria] ：: Light fastness of 95% or more ：: Light fastness of 90% or more and less than 95% Δ: Light fastness of 80% or more and less than 90% ×: Light fastness of less than 80%

(3) Water resistance After the print density of a specific print portion of the sample (before ultraviolet irradiation) obtained in the above (2) light resistance was measured, this was immersed vertically in still water for 10 seconds, and Raised vertically. 2
After air drying at 5 ° C. for 24 hours, the print density of the print at the same place as before the immersion was measured in the same manner as described above, and the water resistance was calculated by the formula: [water resistance] (%) = [print density after immersion] / [Print density before immersion] × 100 and evaluated based on the following evaluation criteria.

[Evaluation Criteria] ：: Water resistance is 95% or more ○: Water resistance is 90% or more and less than 95% Δ: Water resistance is 80% or more and less than 90% ×: Water resistance is less than 80%

(4) Average Particle Size The average particle size was measured using a Coulter counter N4 (manufactured by Coulter).

[0080]

[Table 2]

From the results shown in Table 2, it can be seen that all of the water-based inks obtained in each of the examples are excellent in light fastness and water fastness and have good print density.

[0082]

The water-based ink of the present invention has a good print density, and is excellent in light resistance and water resistance, and therefore can be suitably used as a water-based ink for ink jet recording.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Michitaka Sawada 1334 Minato, Wakayama Kao Corporation Research Institute F-term (reference) 2C056 EA04 EA13 FC01 2H086 BA53 BA56 BA59 BA60 4J039 AD02 AD09 AD12 AD22 AE11 BC51 BC52 BE02 CA06 EA29 EA35 EA38 EA42 GA24

Claims (4)

[Claims] 1. An aqueous dispersion of polymer particles containing a coordinator C of a dye A capable of coordinating with a metal ion in a bidentate or more position and a compound B containing the metal ion capable of coordinating with the dye A. Aqueous ink for inkjet recording. 2. The polymer of the formula (I): X (Y) _n Si (R ¹ ) _3-m (Z) _m (I) wherein X is a polymerizable unsaturated group; A bonding group of
R ¹ may be the same or different and each represents a hydrogen atom, a lower alkyl group, an aryl group or an alkoxy group;
Z is essentially non-reactive under copolymerization conditions and is a residue of a monovalent siloxane polymer having a number average molecular weight of 300 or more; m is an integer of 1 to 3; n represents 0 or 1) At least one selected from the group consisting of a silicone macromer represented and a (meth) acrylamide monomer having no salt-forming group, a polymerizable unsaturated monomer having a salt-forming group, and a copolymerizable with these monomers. The water-based ink according to claim 1, which is a polymer obtained by copolymerizing a monomer composition containing a monomer. 3. A dye A capable of coordinating bidentate or more with a metal ion and a compound B containing a metal ion capable of coordinating with the dye A
3. The aqueous ink according to claim 1, wherein at least one of the above is soluble in an organic solvent. 4. The aqueous ink according to claim 1, wherein the average particle size of the polymer particles in the aqueous dispersion is 20 to 200 nm.