JPH11349875A - Ink composition which realizes image excellent in resistance to fretting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink compsn. which can realize an image excellent in resistance to fretting by compounding a colorant, a water-soluble org. solvent, and fine polymer particles having a ligand structure capable of forming a chelate with a metal ion. SOLUTION: Pref. examples of the ligand structure of the polymer particle are a β-diketone structure, a polyamine structure, an iminodiacetic acid structure, a 2-oxazolidone structure, and a structure represented by the formula (wherein P is a polymer structure part; and R is an alkyl or aryl). A polymethacrylic ester, polystyrene, polyvinyl acetate, and a polyamide are the examples. When the ink compsn. is attached to the surface of a recording medium, the solvent part sinks into the medium or evaporates to thereby fix the colorant and the polymer particles; in that case, the ligand structure of the polymer particles and a metal ion present on the surface of the medium form a chelate, causing the colorant and the polymer particles to be agglomerated rapidly and fixed on the surface of the medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition, and more particularly, to an ink composition preferably used in an ink jet recording method.

2. Description of the Related Art An ink jet recording method is a printing method in which small droplets of ink are made to fly and adhere to a recording medium such as paper to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive apparatus.

Conventionally, an ink composition used for ink jet recording generally comprises a water-soluble dye or pigment, a water-soluble organic solvent, and water. One of the performances required for this ink is that an image with less bleeding can be realized. In particular, in multicolor printing, one color ink often comes into contact with another ink. The mixing or bleeding of two inks of different colors on the recording medium forms an undesired color, resulting in reduced image resolution, color separation, edge sharpness, and color purity. Therefore, an image with less blur can be realized.
This is an important performance required for the ink composition.

[0004] Recently, attempts have been made to use pigments as coloring materials. Pigments are excellent in water resistance and light resistance as compared with dyes, but are often pointed out to be inferior in scratch resistance because they remain as particles on a recording medium to form pixels. Further, since the pigment is essentially water-insoluble, it is necessary to stably disperse the pigment in the ink composition. For the stable dispersion of pigments, some additions of resins have been proposed. For example, JP-B-62-1426 discloses an ink in which a pigment and a resin emulsion are dispersed in water, and JP-A-55-157668 discloses that an ink is dispersed in a water-insoluble resin emulsion dispersion. Japanese Patent Application Laid-Open No. 1-217088 discloses that an emulsion having a specific film-forming temperature is used.
Japanese Patent Application Laid-Open No. HEI 4-18462 and JP-A-4-18462 similarly disclose an ink using a resin emulsion. Further, JP-A-56-147859 and JP-A-56-1
No. 47860 and Japanese Patent Publication No. 4-5703 propose an aqueous dispersion-based pigment ink using a polymer dispersant and a water-soluble organic solvent. Further, the pigment does not soak into the recording medium as in the case of the dye and is fixed, but is basically fixed and fixed to the surface of the recording medium, so that the abrasion resistance may be poor. In order to improve the fixability of the pigment, it has been proposed to add a resin component to the ink composition to firmly fix the pigment on the surface of the recording medium. However, the addition of a resin to such a pigment-based ink composition may involve an increase in the viscosity of the ink composition, and in some cases may not be suitable for an inkjet recording method.
It was also observed that the addition of the resin changed the physical properties of the ink composition and caused the nozzle plate of the ink jet recording head to become wet. As a result, the ink composition may not be discharged, or the flight stability may be reduced, such as occurrence of flight bending. Further, it has been observed that the addition of a water-soluble resin to the ink lowers the water resistance of an image, and that an increase in the viscosity of the ink composition due to evaporation of water causes clogging of the nozzles of the recording head.

On the other hand, as an ink jet recording method, a method has recently been proposed in which a polyvalent metal salt solution is applied to a recording medium and then an ink composition containing a dye having at least one carboxyl group is applied ( For example, JP-A-5-202328). In this method,
An insoluble complex is formed from the polyvalent metal ion and the dye.
It is said that the presence of this composite makes it possible to obtain a high-quality image having water resistance and no color bleed (for example, JP-A-6-106735).

Further, by using a color ink containing a surfactant or a penetrative solvent for imparting permeability and a salt in combination with a black ink which is thickened or aggregated by the action of the salt, the image density is reduced. It has also been proposed to obtain a high-quality color image that is high and has no color bleed (JP-A-6-106735). That is, an ink jet recording method has been proposed in which a good image can be obtained by printing two liquids of a first liquid containing a salt and an ink composition.

In addition, for example, Japanese Patent Application Laid-Open No. 3-240
557 and JP-A-3-240558 propose an ink jet recording method for printing two liquids.

In such an ink jet recording method for printing two liquids, further improvement in performance is desired.
One of them is to improve the fixing ability of the coloring component. In ink jet recording, plain paper and recycled paper are often used in addition to a dedicated recording medium, and many of these recording media are easily penetrated by ink. For this reason, even if a high-quality image can be obtained with a certain type of medium, image bleeding or color bleeding may occur with another type of medium, and improvement is required. The second is prevention of printing unevenness. The printing unevenness is a disturbance in the color density of a printed matter due to a bias of a coloring component on paper. Printing unevenness is not a major problem for characters of normal size, but it is an important problem in applications where graphics, graphs, and the like must be printed.

[0009]

SUMMARY OF THE INVENTION The present inventors have now found that an ink composition containing a resin having a certain chelate structure can realize an image having excellent abrasion resistance and further have various characteristics required for the ink composition. Has been found to be realized at a high level. The present invention is based on this finding. Accordingly, an object of the present invention is to provide an ink composition capable of realizing an image having excellent scratch resistance. Another object of the present invention is to provide an ink composition that realizes various characteristics required for an ink composition used in an ink jet recording method such as clogging stability, ejection stability, and storage stability at a high level. I have. Another object of the present invention is to provide an ink jet recording method for printing two liquids capable of realizing a high quality image. The ink composition according to the present invention is an ink composition comprising a coloring material, water, a water-soluble organic solvent, and polymer fine particles, and the polymer fine particles can form a chelate with a metal ion. It is composed of a polymer having a ligand structure. In addition, the ink jet recording method using two liquids according to the present invention forms an image by adhering the ink composition and a reaction liquid containing a reactant that generates an aggregate upon contact with the ink composition. The step of performing

[0010]

DETAILED DESCRIPTION OF THE INVENTION Ink Composition The ink composition according to the present invention is used in a recording method using the ink composition. Examples of the recording method using the ink composition include an ink jet recording method, a recording method using a writing instrument such as a pen, and various other printing methods. In particular, the ink composition according to the present invention is preferably used for an ink jet recording method.

The ink composition according to the present invention basically comprises
It comprises a coloring material, water, a water-soluble organic solvent, and polymer fine particles. The polymer fine particles are made of a polymer having a ligand structure capable of forming a chelate with a metal ion.

2. In the present invention, a ligand structure capable of forming a chelate with a metal ion of a polymer fine particle has a plurality of atoms for supplying electrons for forming a coordination bond, and the atoms are separated at appropriate intervals. Exists, and as a result, refers to a structure in which a plurality of these atoms form a metal chelate compound in such a manner as to sandwich a metal ion. According to a preferred embodiment of the present invention, preferred examples of such a ligand structure include β-
Diketone structure, polyamine structure, iminodiacetic acid structure, sarcosine structure, ethanol amino acid structure, glycine structure, xanthic acid structure, amidoxime structure, amine structure, pyridine structure, imidazole structure, phosphonic acid structure, phosphinic acid structure, phosphoric acid structure, Schiff base Construction,
Oxime structure, hydroxam structure, aminopolycarboxylic acid structure, thiol structure, polythioalcohol structure, 2-
A pyrrolidone structure, and a 2-oxazolidone structure. Furthermore, according to a specific embodiment of the present invention, for example,
Examples of the ligand structure capable of forming a chelate with a metal ion include a structure represented by the following formula.

Embedded image Wherein P is a polymer structure moiety, and R is an alkyl group (preferably a C _1-20 alkyl group, more preferably a C _1-10 alkyl group, most preferably a methyl group) or an aryl group ( For example, phenyl, naphthyl,
Trill)

The structure in the case where the ligand structure of the above formula forms a metal chelate with, for example, a divalent metal is considered as follows.

Embedded image (In the formula, Mt represents a divalent metal, and P and R are as defined above.) The mechanism by which an ink composition containing polymer fine particles as described above can realize a good image is considered as follows. Can be However, the following theory is only an assumption, and the present invention is not limited to the following theory.

When the ink composition adheres to the recording medium surface, the solvent component soaks or evaporates into the recording medium, fixing the coloring material and the polymer fine particles on the recording medium. At this time, when the ligand structure of the polymer fine particles forms a chelate with a metal ion present on the surface of the recording medium, the coloring material and the polymer fine particles rapidly aggregate. as a result,
The coloring material and the polymer fine particles remain on the surface of the recording medium and strongly adhere to the surface of the recording medium, so that good scratch resistance of an image can be obtained.

More specifically, when the coloring material is a dye,
The dye penetrates and fixes to the recording medium to some extent with the solvent component, but the abrasion resistance is improved by forming a layer composed of polymer fine particles thereon. Further, when the coloring material is a pigment, the polymer fine particles themselves help fix the pigment to the surface of the recording medium, but the ligand structure of the polymer fine particles is present on the surface of the recording medium. To form a chelate with the metal ions, thereby making the pigment more firmly adhered to the recording medium.

Further, according to a preferred embodiment of the present invention described later, it is advantageous that the polymer fine particles have a film-forming ability, because the film-formed polymer more firmly fixes the colorant on the surface of the recording medium. . Particularly in this mode, a good image can be realized regardless of the type of the recording medium. Specifically, good images can be realized not only on special paper but also on plain paper and recycled paper.

According to a preferred embodiment of the present invention, the particle size of the polymer fine particles is 0.4 μm or less, more preferably about 0.005 to 0.3 μm.

The content of the polymer particles in the ink composition according to the present invention is preferably about 1 to 10% by weight of the ink composition, more preferably 1 to 5% by weight. According to a preferred embodiment of the present invention, the polymer fine particles preferably have a single particle structure. According to still another preferred embodiment, the polymer fine particles preferably have a core-shell structure composed of a core portion and a shell layer surrounding the core portion.

According to a preferred embodiment of the present invention, the polymer fine particles are preferably dispersed in the ink composition as dispersed particles of a polymer emulsion. That is,
In preparing the ink composition according to the present invention, the polymer fine particles are preferably mixed in a form of a polymer emulsion with the components constituting the ink composition. According to a preferred embodiment of the present invention, the particle diameter of the polymer fine particles in the polymer emulsion is preferably about 0.4 μm or less, more preferably about 0.005 to 0.3 μm. According to a preferred embodiment of the present invention, the polymer constituting the polymer fine particles preferably has a glass transition point of 30 ° C. or lower. By using such a polymer, the ink composition according to the present invention more reliably forms a film at normal temperature.

Further, according to a preferred embodiment of the present invention, when the polymer fine particles are dispersed in the ink composition as dispersed particles of the polymer emulsion, the minimum film forming temperature of the polymer emulsion is preferably 30 ° C. or lower. Here, the minimum film forming temperature refers to a temperature at which a transparent continuous film is formed when a polymer emulsion is thinly cast on a metal plate such as aluminum and the temperature is increased. In a temperature region lower than the minimum film forming temperature, a white powder is formed. The temperature at this boundary is defined as the minimum film forming temperature. According to this aspect, it is possible to further improve the quick drying property, the touch property, the abrasion resistance, and the water resistance of the printed matter.

When the ink composition adheres to the recording medium and water and a water-soluble organic solvent in the vicinity of the polymer particles penetrate into the recording medium and decrease, the polymer particles having the ability to form a film can form polymer particles. The coalesces and fuses to form a film containing the coloring material. Therefore, the obtained image has excellent abrasion resistance and also excellent water resistance. When the coloring material is a dye, it is considered that a part of the dye permeates into the recording medium and the polymer fine particles take in a part of the dye and remain on the surface of the recording medium to form a film. It is considered that this film provides good scratch resistance and water resistance.

According to a preferred embodiment of the present invention, it is preferable that the fine polymer particles contain a thermoplastic polymer as a component. Also, the polymer may be cross-linked. Examples of the thermoplastic polymer include poly (meth) acrylate, polystyrene, (meth) acrylate-styrene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate Copolymer, polybutadiene, polyisoprene, polyvinyl chloride, polyvinylidene chloride, poly (α-
Methylstyrene), styrene-butadiene copolymer,
(Meth) acrylic acid-styrene copolymer, styrene-maleic acid copolymer, styrene-itaconic acid copolymer, styrene-maleic acid ester copolymer, styrene-itaconic acid ester copolymer, polyester, polyurethane, poly Examples include, but are not limited to, those selected from the group consisting of siloxanes and polyamides.

The polymer fine particles used in the present invention can be produced as follows. First, a monomer having a ligand structure and another monomer can be produced by an appropriate polymerization method, for example, a method of emulsion polymerization in the presence of a polymerization catalyst and an emulsifier. In addition, a monomer having no ligand structure but having a functional group can be polymerized by a suitable polymerization method, for example, emulsion polymerization to obtain a polymer, and the polymer can be produced by introducing a ligand structure into this functional group.

More specifically, the fine polymer particles used in the present invention can be obtained by known emulsion polymerization. That is, it can be obtained by emulsion polymerization of a monomer component having a ligand structure with another monomer component in water in the presence of a polymerization catalyst and an emulsifier. Here, usable emulsifiers include anionic surfactants, nonionic surfactants, and mixtures thereof. Examples of anionic surfactants include alkyl sulfonates, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylbenzene sulfonates, dialkyl sulfosuccinates, fatty acid salts, polyoxyethylene alkyl ether sulfates, and polyoxyethylene sulfonates. Ethylene phenyl ether sulfate and the like. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene-polystyryl phenyl ether, polyoxyethylene-polyoxypropylene glycol, polyoxyethylene-polyoxypropylene alkyl ether, and polyoxyethylene. Fatty acid esters and polyglycerin fatty acid esters are exemplified. This emulsion polymerization is a preferred method for producing polymer fine particles in the form of a polymer emulsion. According to a preferred embodiment of the present invention, from the viewpoint of obtaining a stable polymer emulsion, the HLB thereof is 15 to 20.
The use of a surfactant is preferred.

The monomer component used in the above-mentioned production method is not particularly limited as long as it gives the polymer component of the polymer fine particles described above.
Methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl
(Meth) acrylate, isobutyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate ) Acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth)
Acrylates such as acrylate, 2-hydroxylethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl methacrylate, and glycidyl acrylate; and vinyl esters such as vinyl acetate; acrylonitrile, methacrylonitrile, and the like; Aromatic vinyls such as styrene, 2-methylstyrene, vinyltoluene, t-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene and divinylbenzene; vinylidene halides such as vinylidene chloride and vinylidene fluoride; ethylene, propylene, Isopropylene, butadiene, vinylpyrrolidone, vinyl chloride, vinyl ether, vinyl ketone, chloroprene, etc. and acrylic acid, methacrylic acid, maleic containing carboxyl group Ethylenic unsaturated carboxylic acids such as formic acid or its monoalkyl ester, itaconic acid or its monoalkyl ester, fumaric acid or its monoalkyl ester; amino groups such as acrylamide having an amide group and N, N-dimethylacrylamide; N-methylaminoethyl methacrylate, N-methylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate,
Alkylamino esters of acrylic acid or methacrylic acid such as diethylaminoethyl methacrylate and diethylaminoethyl methacrylate; N- (2-dimethylaminoethyl) acrylamide, N- (2-dimethylaminoethyl) methacrylamide, N, N-dimethylaminopropyl Unsaturated amides having an alkylamino group such as acrylamide, and monovinylpyridines such as vinylpyridine, and vinylethers having an alkylamino group such as dimethylaminoethyl vinyl ether; vinylimidazole and the like, vinylsulfonic acid, styrenesulfonic acid, and the like. Examples thereof include those having a sulfone group, such as salts thereof, 2-acryloylamino-2-methylpropanesulfonic acid, and salts thereof. These monomers can be used alone or in combination of two or more.

As described above, the polymer fine particles can have a single particle structure or a core-shell structure.

Here, the polymer fine particles having a core-shell structure are not particularly limited, but can be produced by a known method, generally by multistage emulsion polymerization or the like.

When the fine polymer particles have a core-shell structure, the ligand structure is preferably present in the shell layer.

According to a preferred embodiment of the present invention, it is preferable that the polymer fine particles have a functional group of either a carboxyl group or a sulfonic acid group in both a single particle structure and a core-shell structure. And those having a hydroxyl group or an amino group are preferred. In the case of a core-shell structure, these functional groups are preferably present in the shell layer. These groups may be present in the structure of the monomer in the above-mentioned production method, or may be added to the surface of the polymer fine particles by graft polymerization or the like after obtaining them. Although the presence of such a group seems to be preferable based on the following possible mechanism, the following theory is merely an assumption and the present invention is not limited thereto. Hydrophilic groups such as carboxyl groups, sulfonic acid groups, amide groups, amino groups, and hydroxyl groups on the surface of such polymer particles are hydrogen-bonded to the hydroxyl groups (OH groups) of cellulose constituting paper fibers, and the polymer fine particles and paper The fibers are firmly adsorbed. As a result, penetration of a coloring material such as a pigment into the paper is suppressed. In particular, when the polymer fine particle structure is a core-shell structure and the shell layer contains a hydrophilic group such as a carboxyl group, a sulfonic acid group, an amide group, an amino group, or a hydroxyl group, these hydrophilic groups on the surface of the fine particle particle are used. The effect is further improved because the ratio of the presence of is increased. The water and water-soluble organic solvent in the vicinity of the polymer particles adsorbed on the paper fibers penetrate into the paper and decrease, so that the polymer particles coalesce and further fuse together to take in a color material such as a pigment to form a film. Is formed. Further, the ink composition containing the polymer fine particles having these groups does not wet the surface of the nozzle plate of the recording head of the ink jet printer which has been subjected to the water repellent treatment. As a result, ejection failure due to wetting of the surface of the nozzle plate of the ink and occurrence of flight bending are not caused, and the ejection stability is excellent. Furthermore, the ink composition containing the polymer fine particles having these groups has excellent storage stability.

3. Coloring Material The coloring material contained in the ink composition according to the present invention may be either a dye or a pigment, but is preferably a pigment.

As the dyes, direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes,
Various dyes such as a soluble vat dye and a reactive disperse dye can be used.

As the pigment, an inorganic pigment or an organic pigment can be used. As inorganic pigments, in addition to titanium oxide and iron oxide, contact method, furnace method,
Carbon black produced by a known method such as a thermal method can be used. Examples of organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.) and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines) Pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc.), dye chelates (for example,
Basic dye type chelates, acid dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used. In particular, as carbon black used as black ink, Mitsubishi Chemical No.2300, No.900, MCF88, No.3
3, No.40, No.45, No.52, MA7, MA8, MA100, No2200B etc.
Columbia Raven5750, Raven5250, Raven5000, Rav
en3500, Raven1255, Raven700, etc.
gal 400R, Regal 330R, Rega l660R, Mogul L, Monarch700,
Monarch 800, Monarch 880, Monarch 900, Monarch 10
00, Monarch 1100, Monarch 1300, Monarch 1400 etc.
Degussa Color Black FW1, ColorBlack FW2, Co
lor Black FW2V, Color Black FW18, Color Black FW20
0, ColorBlack S150, Color Black S160, Color Black
S170, Printex 35, Printex U, Printex V, Printex 140
U, Special Black 6, Special Black 5, Special Black
4A, Special Black 4 etc. can be used. Pigment used for yellow ink is CIPigment Yellow
1, CIPigment Yellow 2, CIPigment Yellow3, CI
Pigment Yellow 12, CIPigment Yellow 13, CIPigm
ent Yellow 14C, CIPigment Yellow 16, CIPigment
Yellow 17, CIPigment Yellow 73, CIPigment Yell
ow 74, CIPigment Yellow 75, CIPigment Yellow 8
3, CIPigment Yellow 93, CIPigment Yellow95, C.
I. Pigment Yellow97, CIPigment Yellow 98, CIPig
ment Yellow114, CIPigment Yellow128, CIPigment
Yellow129, CIPigment Yellow151, CIPigment Yel
low154 and the like. Pigments used in magenta ink include CI Pigment Red 5, CI Pigment
Red 7, CIPigment Red 12, CIPigment Red 48 (C
a), CIPigment Red48 (Mn), CIPigment Red 57 (Ca),
CIPigment Red 57: 1, CIPigment Red 112, CIPi
gment Red 123, CIPigment Red 168, CIPigment Re
d 184, CIPigment Red 202 and the like. Pigments used in cyan ink include CI Pigment Bl
ue 1, CIPigment Blue 2, CIPigment Blue 3, CI
PigmentBlue 15: 3, CIPigment Blue 15:34, CIPigm
ent Blue 16, CIPigment Blue22, CIPigment Blue
60, CIVat Blue 4 and CIVat Blue 60. However, it is not limited to these.

The particle size of these pigments is preferably 10 μm or less, more preferably 0.1 μm or less.

According to a preferred embodiment of the present invention, these pigments are preferably added to the ink as a pigment dispersion obtained by dispersing in an aqueous medium with a dispersant or a surfactant. As a preferred dispersant, a dispersant commonly used for preparing a pigment dispersion, for example, a polymer dispersant can be used. It will be apparent to those skilled in the art that the dispersant and surfactant contained in this pigment dispersion will also function as the dispersant and surfactant of the ink composition. Preferred examples of the polymer dispersant include natural polymers, specific examples of which include glue, gelatin, casein, proteins such as albumin, gum arabic, natural gums such as tragacanth gum, glucosides such as savonin, Examples include alginic acid and alginic acid derivatives such as alginic acid propylene glycol ester, alginic acid triethanolamine and ammonium alginate, and cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose and ethylhydroxycellulose. Further, preferred examples of the polymer dispersant include synthetic polymers, polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylate-acrylonitrile copolymer,
Acrylic resins such as vinyl acetate-acrylate copolymer, acrylic acid-acrylate copolymer,
Styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid -Styrene-acrylic resin such as acrylate copolymer, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-maleic acid copolymer, and Vinyl acetate-based copolymers such as vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, and vinyl acetate-acrylic acid copolymer And copolymers and salts thereof. Among them, a copolymer of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and a polymer composed of a monomer having both a hydrophobic group and a hydrophilic group in a molecular structure are preferable.

The content of the pigment in the ink composition of the present invention is preferably about 0.5 to 25% by weight, more preferably about 2 to 15% by weight.

4. Water-Soluble Organic Solvent Also, the ink composition according to the present invention comprises a water-soluble organic solvent. The water-soluble organic solvent is preferably a low-boiling organic solvent, and examples thereof include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, sec-butanol and tert.
-Butanol, iso-butanol, n-pentanol and the like. Particularly, a monohydric alcohol is preferable. Low-boiling organic solvents have the effect of shortening the drying time of the ink. The amount of the low boiling organic solvent added is preferably 0.1 to 30% by weight of the ink, more preferably 5 to 10% by weight.

According to a preferred embodiment of the present invention, the ink composition used in the present invention preferably further comprises a wetting agent comprising a high-boiling organic solvent. Preferred examples of the high-boiling organic solvent include ethylene glycol,
Diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-
Polyhydric alcohols such as hexanetriol, thioglycol, hexylene glycol, glycerin, trimethylolethane, trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, urea, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2 -Imidazolidinones and the like.

The amount of the wetting agent added is 0.1% of the ink.
-30% by weight is preferred, and more preferably 1-10% by weight.

According to a preferred embodiment of the present invention, when the glass transition point of the polymer fine particles is 30 ° C. or less or the minimum film forming temperature of the polymer emulsion is 30 ° C. or less, the use of a water-soluble organic solvent having a boiling point of 180 ° C. or more is preferred. preferable. Preferred examples of the water-soluble organic solvent include ethylene glycol (boiling point: 197 ° C .; hereinafter, the parentheses indicate the boiling point), propylene glycol (187 ° C.), diethylene glycol (245 ° C.), pentamethylene glycol (242
° C), trimethylene glycol (214 ° C), 2-butene-1,4-diol (235 ° C), 2-ethyl-1,
3-hexanediol (243 ° C), 2-methyl-2,
4-pentanediol (197 ° C), N-methyl-2-
Pyrrolidone (202 ° C), 1,3-dimethyl-2-imidazolidinone (257-260 ° C), 2-pyrrolidone (245 ° C), glycerin (290 ° C), tripropylene glycol monomethyl ether (243 ° C), dipropylene Glycol monoethyl glycol (198 ° C.),
Dipropylene glycol monomethyl ether (190
° C), dipropylene glycol (232 ° C), triethylene glycol monomethyl ether (249 ° C), tetraethylene glycol (327 ° C), triethylene glycol (288 ° C), diethylene glycol monobutyl ether (230 ° C), diethylene glycol monoethyl ether (202 ° C.), diethylene glycol monomethyl ether (194 ° C.) and the like. According to a preferred embodiment of the present invention, as a high boiling water-soluble solvent, for example,
Ethylene glycol, diethylene glycol, pentamethylene glycol, trimethylene glycol, 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, glycerin, dipropylene glycol , Tetraethylene glycol, triethylene glycol, N-methyl-2-
It is preferred to use one selected from pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 2-pyrrolidone.

Further, according to a preferred embodiment of the present invention, the ink composition according to the present invention preferably contains a sugar, a tertiary amine, an alkali hydroxide, or ammonia.
Due to these additions, the colorant does not agglomerate or increase in viscosity even during long-term storage, and has excellent storage stability. An ink composition which maintains the dispersibility for a long time and has high ejection stability without clogging of the nozzle at the time of restarting during printing or after printing is interrupted can be obtained.

The saccharides that can be added to the ink composition according to the present invention include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, and the like. Ribose,
Xylose, arabinose, galactose, aldonic acid, glucitol, (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a sugar in a broad sense, and is used to include a substance widely existing in nature such as alginic acid, α-cyclodextrin, and cellulose. Further, derivatives of these saccharides are represented by reducing sugars of the above-mentioned saccharides (for example, sugar alcohols (general formula HOCH ₂ (CHOH) nCH ₂ OH, where n represents an integer of 2 to 5). ), Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thiosugars, etc. Particularly preferred are sugar alcohols.
Specific examples include maltitol and sorbitol.

The content of these saccharides is 0.1 to 0.1% of the ink.
It is in the range of 40% by weight, more preferably 1 to 30% by weight.

The tertiary amine which can be added to the ink composition according to the present invention includes trimethylamine, triethylamine, triethanolamine, dimethylethanolamine, diethylethanolamine, triisopropenolamine, butyldiethanolamine and the like. These may be used alone or in combination.
The addition amount of these tertiary amines to the ink composition of the present invention is 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.
% By weight.

The alkali hydroxides that can be added to the ink composition according to the present invention are potassium hydroxide, sodium hydroxide and lithium hydroxide. It is 5% by weight, preferably 0.05-3% by weight.

The ink composition of the present invention may further contain a surfactant. Examples of surfactants include:
Anionic surfactants (for example, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salts of polyoxyethylene alkyl ether sulfate, etc.), nonionic surfactants (for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester) , Polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkylamines, polyoxyethylene alkylamides, etc.) and acetylene glycols (olefin Y, and Surfynol 82, 104,
440, 465, and 485 (all Air Products
and Chemicals Inc.). These can be used alone or in combination of two or more.

The ink composition of the present invention may contain general-purpose polymer fine particles in addition to the above-mentioned polymer fine particles. The general-purpose polymer fine particles are preferably used in the form of a polymer emulsion. Examples of the polymer fine particles include an acrylic polymer, a vinyl acetate polymer, a styrene-butadiene copolymer, a vinyl chloride polymer, an acryl-styrene copolymer, a butadiene polymer, and a styrene polymer. Further, the particle size of these polymer fine particles is preferably about 0.4 μm or less, more preferably 0.0 μm or less.
It is about 0.5 to 0.3 μm. As these polymer fine particles, those commercially available in the form of a polymer emulsion can also be used. For example, Microgel E-1002, E-5002 (styrene-acrylic polymer emulsion, manufactured by Nippon Paint Co., Ltd.), Bon Coat 4001 (acrylic polymer emulsion, manufactured by Dainippon Ink and Chemicals, Inc.), Boncoat 5454
(Styrene-acrylic polymer emulsion, manufactured by Dainippon Ink and Chemicals, Inc.), SAE-1014 (styrene-acrylic polymer emulsion, manufactured by Zeon Corporation), Sibinol SK-200 (acrylic polymer emulsion, Seiden Chemical Co., Ltd.) Manufactured).

In addition, if necessary, a pH adjuster, a preservative, a fungicide, a phosphorus-based antioxidant and the like may be added.

5. Water-soluble Sequestering Agent According to a preferred embodiment of the present invention, the ink composition according to the present invention preferably comprises a sequestering agent. In the present invention, the water-soluble sequestering agent refers to a material capable of rapidly generating a divalent or higher valent metal ion and a stable water-soluble chelate.

By the addition of the metal sequestering agent, the storage stability of the ink composition can be improved, and nozzle clogging can be effectively prevented. The reason is considered as follows. That is, the sequestering agent captures the polyvalent metal ions present in the ink composition as impurities derived from the coloring material, water, and the water-soluble organic solvent. As a result, it is considered that the reason is that polymer fine particles having a ligand structure capable of forming a chelate with metal ions can be effectively prevented from being aggregated by metal ions in the ink composition. Therefore, it is preferable to avoid adding an excessive amount of a metal sequestering agent, because it deprives the metal ions present on the surface of the recording medium of a reaction with the polymer fine particles and lowers the cohesiveness of the ink composition. According to a preferred embodiment of the present invention, the water-soluble sequestering agent is preferably added in a range of 0.0001 to 5% by weight, more preferably 0.01 to 1% by weight.
% By weight.

According to a preferred embodiment of the present invention, the sequestering agent is preferably mixed with other components prior to the addition of the fine polymer particles during the production of the ink composition.
Thereby, metal ions as impurities can be effectively captured.

Examples of the water-soluble sequestering agent used in the present invention include ethylenediaminetetraacetic acid, iminodiacetic acid, nitriloacetic acid, diethylenetriaminepentaacetic acid,
Triethylenetetramine hexaacetic acid, cyclohexane-
Examples thereof include those selected from the group consisting of 1,2-diaminetetraacetic acid, N-hydroxyethylethylenediaminetriacetic acid, ethylene glycol diethyletheraminetetraacetic acid, ethylenediaminetetrapropionic acid, pyrophosphoric acid, and triphosphoric acid.

6. Method for Producing Ink Composition The ink composition according to the present invention can be produced by dispersing and mixing the above components by an appropriate method. Preferably, first, the pigment, the polymer dispersant, and water are mixed with an appropriate dispersing machine (for example, a ball mill, a sand mill, an attritor, a roll mill, an agitator mill, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a jet mill, an ang mill). To prepare a uniform pigment dispersion, and then, in water, a water-soluble organic solvent having a boiling point of 180 ° C. or higher,
After adding sugar, a pH adjuster, a preservative, a fungicide, etc. and sufficiently dissolving, a polymer emulsion containing the polymer fine particles as dispersed particles is added, and the mixture is sufficiently stirred at room temperature with a suitable disperser to remove the ink solvent. Prepare. While stirring the pigment dispersion with an appropriate dispersing machine, the ink solvent is gradually dropped, and further stirred sufficiently. After sufficient stirring, filtration is performed to remove coarse particles and foreign substances that cause clogging, thereby obtaining a target ink composition.

As described above, the sequestering agent is preferably mixed with other components prior to the addition of the polymer fine particles.

7. Inkjet recording method The ink composition according to the present invention is preferably used in an inkjet recording method as described above. Further, the ink composition according to the present invention is preferably used in a color inkjet recording method using a plurality of color ink compositions. This color inkjet recording method will be described with reference to the drawings.

The ink jet recording apparatus shown in FIG. 1 is a mode in which an ink composition is stored in a tank, and the ink composition is supplied to a recording head via an ink tube. That is, the recording head 1 and the ink tank 2 are connected by the ink tube 3. Here, the inside of the ink tank 2 is partitioned, and a room for the ink composition, and in some cases, a plurality of color ink compositions is provided.

The recording head 1 moves along the carriage 4
It is moved by a timing belt 6 driven by a motor 5. On the other hand, the paper 7 as a recording medium is placed at a position facing the recording head 1 by the platen 8 and the guide 9. In this embodiment, a cap 10 is provided. A suction pump 11 is connected to the cap 10 to perform a so-called cleaning operation. The sucked ink composition is supplied to the waste ink tank 13 via the tube 12.
Is stored.

FIG. 2 is an enlarged view of the nozzle surface of the recording head 1. The portion indicated by 1c is the nozzle surface of the ink composition, and the nozzles 22, 23, 24, and 25 eject the yellow ink composition, the magenta ink composition, the cyan ink composition, and the black ink composition, respectively. You.

Further, an ink jet recording method using the recording head shown in FIG. 2 will be described with reference to FIG.
The recording head 1 moves in the direction of arrow A. During the movement, the ink composition is printed to form a print area 31.

Further, in some ink jet recording apparatuses, replenishment of the ink composition is performed by replacing a cartridge which is an ink tank. This ink tank may be integrated with the recording head.

FIG. 4 shows a preferred example of an ink jet recording apparatus using such an ink tank. In the figure, the same members as those of the apparatus of FIG. 1 are denoted by the same reference numerals. In the embodiment of FIG. 4, the recording head 1 is integrated with the ink tank 2. The printing method may be basically the same as that of the apparatus shown in FIG. And in this aspect,
The recording head 1 and the ink tank 2 move on the carriage 4 together.

8. Recording method using two liquids Furthermore, according to a preferred embodiment of the present invention, the ink composition according to the present invention comprises an ink composition and a reactant that contacts the ink composition to form an aggregate. It is preferably used in a recording method using two liquids including a reaction liquid. According to this method, excellent fixability, finger touch and abrasion resistance,
An image having excellent water resistance and good OD value and gloss can be obtained. The reason is that the dispersing state of the coloring material and the polymer emulsion causes the reaction agent to disintegrate, causing agglomerates, and has excellent fixability to a recording medium such as paper, high OD value and glossiness, It is believed that high-quality images without feathering, bleeding, or bleeding are realized.

Examples of the reactant that forms an aggregate upon contact with the ink composition according to the present invention include a polyvalent metal salt and / or
Or polyallylamine and / or its derivative. In particular, the polyvalent metal ion derived from the polyvalent metal salt forms a ligand structure and a chelate structure of the polymer fine particles, rapidly disintegrates the dispersed state of the polymer fine particles, and promotes the formation of aggregates. As a result, the coloring material is suppressed from penetrating into the recording medium, and an image with less bleeding can be realized. Further, as described above, some of the ligand structures form chelates with metal ions on the recording medium, and fix the coloring material firmly on the recording medium surface. Further, polyallylamine or a derivative thereof as a reactant does not directly react with the ligand structure of the polymer fine particles, but rapidly disintegrates the dispersed state of the polymer fine particles and promotes the formation of aggregates. Further, the ligand structure of the polymer fine particles strongly binds to metal ions on the recording medium. Therefore, even when polyallylamine or a derivative thereof is used as the reactant, an image with less bleeding and excellent scratch resistance can be realized.

As the polyvalent metal salt, those which are composed of polyvalent metal ions having two or more valences and anions bonded to these polyvalent metal ions and which are soluble in water are used. Specific examples of the polyvalent metal ion include Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg
Divalent metal ions such as ²⁺ , Zn ²⁺ , Ba ²⁺ , Al ³⁺ , F
Examples include trivalent metal ions such as e ³⁺ and Cr ³⁺ . Specific examples of the anion include Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ ,
ClO ₃ ^- and CH ₃ COO ^- and the like, preferably, nitrate ions or carboxylate ions. Here, the carboxylate ion is preferably derived from a carboxylic acid selected from the group consisting of a saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms and a carbocyclic monocarboxylic acid having 7 to 11 carbon atoms. is there. Preferred examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, and hexanoic acid. Particularly, formic acid and acetic acid are preferable. A hydrogen atom on the saturated aliphatic hydrocarbon group of the monocarboxylic acid may be substituted with a hydroxyl group. Preferred examples of such a carboxylic acid include benzoic acid and naphthoic acid, and more preferably benzoic acid. Is an acid.

The polyallylamine and polyallylamine derivative can be cationic polymers which are soluble in water and positively charged in water. For example, the following formulas (a), (b) and (b) The derivative represented by (c) is mentioned.

[0065]

Embedded image (In the formula, X ^- represents a chloride ion, a bromide ion, an iodide ion, a nitrate ion, a phosphate ion, a sulfate ion, an acetate ion, and the like.) Further, a polymer obtained by copolymerizing allylamine and diallylamine, and diallylmethylammonium chloride Copolymers with sulfur dioxide can be used.

The reaction solution used in the present invention basically comprises a polyvalent metal salt and / or polyallylamine and / or a polyallylamine derivative, and water.

The concentration of the polyvalent metal salt in the reaction solution may be appropriately determined within a range in which the effect of preventing printing quality and clogging can be obtained, but is preferably about 0.1 to 40% by weight of the reaction solution. And more preferably about 5 to 25% by weight. The concentration of the polyallylamine and / or polyallylamine derivative in the reaction solution is preferably 0.5 to 10% by weight of the reaction solution. .

In the present invention, the reaction solution preferably contains a wetting agent such as a high-boiling organic solvent. Preferred examples of the high boiling point organic solvent include those described in the section of the ink composition. The high boiling point organic solvent prevents clogging of the head by preventing the reaction solution from drying.

The amount of the high-boiling organic solvent is not particularly limited, but is preferably about 0.5 to 40% by weight, more preferably about 2 to 20% by weight.

According to a more preferred embodiment of the present invention, it is preferable to add triethylene glycol monobutyl ether and glycerin as the high boiling organic solvent. When these are added in combination, the addition amounts of triethylene glycol monobutyl ether and glycerin are preferably about 10 to 20% by weight and about 1 to 15% by weight, respectively. Further, the above-mentioned surfactant may be added to the reaction solution. In addition, a pH adjuster such as ammonia, a preservative, a fungicide, and the like may be added to the reaction solution as needed in order to improve storage stability.

The reaction liquid may be colored by adding a color material, and may have the function of the ink composition.

Regarding the adhesion of the reaction liquid to the recording medium, either of the method of selectively applying the reaction liquid only at the place where the ink composition is applied and the method of attaching the reaction liquid to the entire paper can be used. Good. The former is economical because it can minimize the consumption of the reaction liquid, but requires a certain degree of accuracy in the position where both the reaction liquid and the ink composition are adhered. On the other hand, in the latter, the demand for the accuracy of the adhesion position of the reaction liquid and the ink composition is eased compared to the former, but a large amount of the reaction liquid is attached to the whole paper,
Paper is easy to curl. Therefore, which method is adopted may be determined in consideration of the combination of the ink composition and the reaction liquid.

According to a preferred embodiment of the present invention, the ink composition and the reaction liquid are preferably applied to a recording medium by a so-called ink jet recording method. That is, a recording method in which droplets are ejected from ink ejection holes of an ink jet recording head and adhered to a recording medium to form an image is preferable.

The ink jet recording method using the ink composition and the reaction liquid according to the present invention will be further described with reference to the drawings.

The ink jet recording apparatus shown in FIG. 5 is an embodiment in which the ink composition and the reaction liquid are stored in a tank, and the ink composition and the reaction liquid are supplied to the recording head via an ink tube. That is, the recording head 51 and the ink tank 52 are communicated by the ink tube 3. Here, the inside of the ink tank 52 is partitioned, and a room for an ink composition, and in some cases, a plurality of color ink compositions and a room for a reaction liquid are provided.

The recording head 51 is moved along the carriage 4 by a timing belt 6 driven by a motor 5. On the other hand, the paper 7 as a recording medium is placed at a position facing the recording head 51 by the platen 8 and the guide 9. In this embodiment, a cap 10 is provided. A suction pump 11 is connected to the cap 10 to perform a so-called cleaning operation. The sucked ink composition is stored in a waste ink tank 13 via a tube 12.

FIG. 6 is an enlarged view of the nozzle surface of the recording head 51.
Shown in The portion indicated by 51b is the nozzle surface of the reaction liquid, and the nozzle 21 for discharging the reaction liquid is provided in the vertical direction. On the other hand, the portion indicated by 51c is the nozzle surface of the ink composition, and from the nozzles 22, 23, 24, and 25, the yellow ink composition, the magenta ink composition, the cyan ink composition, and the black ink composition are respectively provided. Discharged.

Further, an ink jet recording method using the recording head shown in FIG. 6 will be described with reference to FIG.
The recording head 51 moves in the direction of arrow A. During the movement, the reaction liquid is discharged from the nozzle surface 51b, and the recording medium 7
A belt-like reaction liquid attachment region 61 is formed on the upper surface. Next, the recording medium 7 is transported by a predetermined amount in the paper feed direction arrow B. During that time, the recording head 51 moves in the direction opposite to the arrow A in the figure, and returns to the position on the left end of the recording medium 7. Then, the ink composition is printed on the reaction liquid adhering area where the reaction liquid has already adhered, and a printing area 62 is formed.

Further, as shown in FIG.
In the above, all the nozzles can be arranged in the horizontal direction. In the figure, 41a and 41b are discharge nozzles of the reaction liquid, and the nozzles 42, 43, 44, and 45 discharge yellow ink composition, magenta ink composition, cyan ink composition, and black ink composition, respectively. You. On the outward path in which the recording head 51 moves in the direction of arrow A, the reaction liquid is discharged from the nozzle 41b and adheres onto the recording medium, and the nozzles 42 to 4
5 is ejected. In the return path, the reaction liquid is discharged from the nozzle 41a and adheres to the recording medium, and predetermined ink of the nozzles 42 to 45 is discharged to the same location. In the recording head of such a mode, printing is possible in both the forward path and the backward path in which the recording head 51 reciprocates on the carriage.
Printing can be expected at a higher speed than when the recording head shown in FIG.

Further, as in the recording head 1 as shown in FIG. 9, a buffer band is provided between the reaction liquid ejection nozzle and the ink composition ejection nozzle, and the reaction liquid and the ink composition are provided on the nozzle surface. It is also preferred to prevent contact with. In the figure, 61, 62, 63, and 64 are discharge nozzles of a yellow ink composition, a magenta ink composition, a cyan ink composition, and a black ink composition, respectively, 66 is a discharge nozzle of a reaction liquid, Reference numeral 65 denotes a buffer band provided for the purpose of avoiding contact between the reaction liquid and the ink composition.

Further, in some ink jet recording apparatuses, replenishment of the ink composition is performed by replacing a cartridge which is an ink tank. This ink tank may be integrated with the recording head.

FIG. 10 shows a preferred example of an ink jet recording apparatus using such an ink tank. In the figure, the same members as those of the apparatus of FIG. 1 are denoted by the same reference numerals. In the embodiment of FIG. 10, the recording heads 51a and 51b are integrated with the ink tanks 52a and 52b. The recording head 51a or 51b discharges the ink composition and the reaction liquid, respectively. The printing method may be basically the same as that of the apparatus shown in FIG. In this embodiment, the recording head 51a and the ink tank 52a, and the recording head 51a and the ink tank 5
2b moves together on the carriage 4.

[0083]

EXAMPLES Production of polymer fine particles 1: stirrer, thermometer,
100 ml of distilled water and 0.1 g of potassium persulfate were added to a flask equipped with a reflux condenser and a dropping funnel, and the internal temperature was heated to 70 ° C. while purging with nitrogen while stirring.
Next, 100 ml of distilled water, 1.0 g of sodium dodecylbenzenesulfonate, 30 g of styrene, 40 g of n-lauryl methacrylate, 5 g of methacrylic acid, and 10 g of methacrylyl acetone (prepared according to Makromol. Chem., 29, 151 (1959)) are mixed. Then, the mixture was stirred to prepare an emulsion.
This was gradually dropped into the flask using a dropping funnel. The obtained emulsion was cooled to room temperature, and this emulsion was filtered with a 0.4 μm filter, and prepared with distilled water so that the concentration of the polymer fine particles became 30%. The obtained emulsion had a minimum film formation temperature of 20 ° C.

Preparation of Inks The black inks shown in the following table were prepared by the following methods.

[0085]

[Table 1]

[Table 2]

Black Ink 1 Carbon black MA7 (manufactured by Mitsubishi Chemical Corporation), a dispersant, and ion-exchanged water are mixed, and glass beads (diameter 1.7 mm, weight of the mixture: 1.) are mixed in a sand mill (manufactured by Yasukawa Seisakusho). (5 times the amount) and dispersed for 2 hours, and then the glass beads were removed to prepare a carbon black dispersion.
Next, 10% by weight of an aqueous polymer emulsion in which the polymer fine particles 1 are dispersed in water (polymer fine particle concentration: 3% by weight) and glycerin were added, and the mixture was stirred at room temperature for 20 minutes. Then, the above carbon black dispersion was gradually stirred. And stirred for another 20 minutes. This is 5 μm
To obtain an inkjet recording ink.

Black Ink 2 Carbon black MA7, a dispersant, and ion-exchanged water were mixed, and mixed with glass beads (1.7 mm in diameter, 1.5 times the weight of the mixture) in a sand mill (Yaskawa Seisakusho) for 2 hours. After the dispersion, the glass beads were removed to prepare a carbon black dispersion. Next, 10% by weight of an aqueous polymer emulsion in which the polymer fine particles 1 are dispersed in water (polymer fine particle concentration: 3% by weight), glycerin and maltitol are added, and the mixture is stirred at room temperature for 20 minutes. The liquid was gradually added dropwise, and the mixture was further stirred for 20 minutes. This was filtered through a 5 μm membrane filter to obtain an inkjet recording ink.

Black Ink 3 Carbon black MA7, a dispersant, and ion-exchanged water were mixed, and mixed with glass beads (1.7 mm in diameter, 1.5 times the weight of the mixture) in a sand mill (manufactured by Yasukawa Seisakusho) for 2 hours. After the dispersion, the glass beads were removed to prepare a carbon black dispersion. Next, 10% by weight of an aqueous polymer emulsion in which polymer fine particles 1 having an acetoacetate group in ion-exchanged water are dispersed in water (polymer fine particle concentration: 3% by weight), glycerin, 2-pyrrolidone, maltitol, sucrose, potassium hydroxide , Triethanolamine and ethyl alcohol at room temperature for 20 minutes.
After stirring for minutes, the above-described carbon black dispersion was gradually added dropwise with stirring, and the mixture was further stirred for 20 minutes.
This was filtered through a 5 μm membrane filter to obtain an inkjet recording ink.

Black Ink 4 Carbon Black Raven 1080 (Columbia
Carbon beads), a dispersant, and ion-exchanged water are mixed, and glass beads (diameter: 1.) are placed in a sand mill (Yaskawa Seisakusho).
The mixture was dispersed for 2 hours together with a mixture (7 mm, 1.5 times the weight of the mixture) to remove the glass beads to prepare a carbon black dispersion. Next, glycerin and 2-pyrrolidone were added to water, and the mixture was stirred at room temperature for 20 minutes. Then, the above carbon black dispersion was gradually added dropwise with stirring, and the mixture was further stirred for 20 minutes. This was filtered through a 5 μm membrane filter to obtain an inkjet recording ink.

Black Ink 5 Carbon black MA7, a dispersant, and ion-exchanged water were mixed, and mixed with glass beads (1.7 mm in diameter, 1.5 times the weight of the mixture) for 2 hours in a sand mill (manufactured by Yasukawa Seisakusho). After the dispersion, the glass beads were removed to prepare a carbon black dispersion. Then, a styrene-acrylic resin emulsion Microgel E-5002 (aqueous emulsion of styrene-acrylic copolymer, minimum film forming temperature: about 80 ° C., manufactured by Nippon Paint Co., Ltd.) in ion-exchanged water having a minimum film forming temperature of about 80 ° C. ) And glycerin, 2
-Pyrrolidone, maltitol, sucrose, and ethyl alcohol were added, and the mixture was stirred at room temperature for 20 minutes. Then, the carbon black dispersion was gradually added dropwise with stirring, and the mixture was further stirred for 20 minutes. This was filtered through a 5 μm membrane filter to obtain an inkjet recording ink.

Ink evaluation test Evaluation 1: Clogging characteristics The ink was filled using an ink jet printer MJ-700V2C (manufactured by Seiko Epson Corporation), and
Printed alphanumeric characters continuously for minutes. After that, stop the printer, without cap, temperature 40 ℃, humidity 25%
Was left for one week under the environment described above. After the standing, alphanumeric characters were printed again, and the number of return operations required until the same printing quality as before the standing was obtained was examined. The evaluation was evaluated according to the following criteria. Print quality equivalent to the initial one was obtained by the return operation of 0 to 2 times: A Print quality equivalent to the initial state was obtained by the return operation of 3 to 5 times: B Same as the initial state by the return operation of 6 or more times Was not obtained: C The results were as shown in the following table.

Evaluation 2: Storage stability 50 cc of the ink was placed in a glass bottle, sealed and sealed at 60 ° C. for 2 hours.
The mixture was left for a week or 4 weeks, and the viscosity and the presence of foreign matter (sediment) were examined. The evaluation was performed as follows. No generation of foreign substances and no change in viscosity: A No generation of foreign substances, but the viscosity changed in a range of less than 1.0 cps: B No generation of foreign substances, but a change in viscosity in a range of more than 1.0 cps: C Foreign matter occurred: D The results were as shown in the table below.

Evaluation 3: Rubbing (excess) resistance (line marker resistance)
Properties) The following ink evaluation tests were performed on the above black inks 1 to 5. The printing method was as follows. That is, characters were printed on the following papers using an inkjet printer MJ-700V2C (manufactured by Seiko Epson Corporation). Ink ejection amount is 0.07 μg / do
t and the density were 360 dpi. The printing test paper used is as follows. Xerox P paper (manufactured by Xerox Co., Ltd.) Riccopy 6200 paper (manufactured by Ricoh Co., Ltd.) Xerox 4024 paper (manufactured by Xerox Co., Ltd.) Neenah Bond paper (manufactured by Kimberly-Clark Co., Ltd.) Xerox R paper (manufactured by Xerox Co., recycled paper) Yamayuri Paper (Recycled paper manufactured by Honshu Paper Co., Ltd.) After the obtained printed matter was air-dried for 24 hours, the printing characters were written at a pressure of 4.9 × 10 5 N using a yellow aqueous highlighter ZEBRA PEN2 (trademark) manufactured by Zebra Corporation. / M2
And the presence or absence of stains in the yellow portion was visually observed, and evaluated as follows. No dirt is generated even after rubbing three times: A There is no dirt up to two rubs, but there is paper with dirt generated at the third rub: B No dirt is generated with one rub, but two times There is a paper that stains after rubbing: C There is a paper that stains after one rubbing: D The results are as shown in the following table.

Evaluation 4: A water drop was dropped on the printed portion of the printed matter obtained in the water resistance evaluation 3,
The state of the printed matter was visually observed and evaluated according to the following criteria. : There is no change in the printed portion where the water drop is dropped: A A mark (water mark) is formed around the printed portion where the water drop is dropped: B The periphery of the printed portion where the water drop is dropped: C The result is as follows: As shown in the table.

[Table 3] Evaluation 1 Evaluation 2 Evaluation 3 Evaluation 4 2 weeks 4 weeks Black ink 1 A AD AA blank ink 2 A A D A A black ink 3 A A D A A blank ink 4 C D D D C black ink 5 A A A C −

Preparation of Color Inks Color inks shown in the following table were prepared by the following methods.

[Table 4]

Color Ink Set 1 Cyan Ink Cyan pigment CETBLUE X-1 (manufactured by Dainippon Ink and Chemicals, Inc.), a dispersant and ion-exchanged water are mixed,
After dispersing in a sand mill (manufactured by Yasukawa Seisakusho) with glass beads (1.7 mm in diameter, 1.5 times the weight of the mixture by weight) for 2 hours, the glass beads were removed to prepare a cyan pigment dispersion. Next, 10% by weight of an aqueous polymer emulsion (polymer fine particle concentration: 3% by weight) in which polymer fine particles 1 having an acetoacetate group were dispersed in ion-exchanged water, glycerin, 2-pyrrolidone, maltitol, sucrose, and ethyl alcohol were added. Add 2 at room temperature
After stirring for 0 minutes, the above-mentioned pigment dispersion was gradually added dropwise with stirring, and the mixture was further stirred for 20 minutes. This is 5
The solution was filtered through a μm membrane filter to obtain an inkjet recording ink. Except for using magenta pigment KETRED 309 (manufactured by Dainippon Ink and Chemicals, Inc.) as the magenta ink pigment, it was prepared in the same manner as (cyan ink 1). It was prepared in the same manner as (Cyan Ink 1) except that the yellow pigment KETYELLOW 403 (manufactured by Dainippon Ink and Chemicals, Inc.) was used as the yellow ink pigment.

Preparation of Reaction Solution A reaction solution was prepared by mixing the following components. Reaction liquid 1 Magnesium nitrate hexahydrate 25% by weight Triethylene glycol monobutyl ether 10% by weight Glycerin 20% by weight Ammonia 0.5% by weight Pure water Remaining amount reaction liquid 2 PAA-L (poly represented by the formula (a)) 20% aqueous solution of allylamine, molecular weight of about 10,000, manufactured by Nitto Boseki Co., Ltd.) 5% by weight Triethylene glycol monobutyl ether 10% by weight Glycerin 20% by weight Pure water

Evaluation 5: Print quality (bleeding) Using the ink jet recording apparatus shown in FIG.
Alternatively, printing was performed on each of the following papers using No. 2 and black inks 1 to 5. For printing, first, the reaction solution is 100% duty
And then 24 letters of the alphabet were printed with black ink. The discharge amount of both the reaction liquid and ink is 0.07
μg / dot and the density were 360 dpi. The printing test paper used is shown below. Xerox P paper (manufactured by Xerox Co., Ltd.) Riccopy 6200 paper (manufactured by Ricoh Co., Ltd.) Xerox 4024 paper (manufactured by Xerox Co., Ltd.) Neenah Bond paper (manufactured by Kimberly-Clark Co., Ltd.) Xerox R paper (manufactured by Xerox Co., recycled paper) Yamayuri Paper (Recycled paper manufactured by Honshu Paper Co., Ltd.) With respect to 24 letters of the alphabet printed by the above method, the number of occurrences of bleeding was counted, and classified and evaluated as follows. The number of occurrences of bleed is less than 100: A The number of occurrences of bleed is 100 to less than 250: B The number of occurrences of bleed is 250 to less than 350: C The number of occurrences of bleed is 350 to less than 500: D The number of occurrences of bleed : 500 to less than 1000: E The number of occurrences of bleeding is 1000 or more: F The results are as shown in Table 5.

Evaluation 6: Abrasion (excess) resistance (line marker resistance)
Properties) The printed matter obtained in the above evaluation 5 was subjected to the same test as in the above evaluation 3. The evaluation results were as shown in Table 5.

Evaluation 7: OD value Using the ink jet recording apparatus shown in FIG. 5, printing was performed on each of the following papers using the reaction liquid 1 or 2 and the black inks 1 to 5. For printing, solid printing is performed and the reaction liquid is 100%
After printing at duty, 100% duty of black ink
Printed at ty. The discharge amount for both the reaction liquid and ink is 0.0
The density was 7 μg / dot, and the density was 360 dpi. The reflection OD value of the solid portion of the obtained printed matter was calculated using Macbeth TR.
927 (manufactured by Macbeth). Table 5 shows the results.
Was as shown in FIG.

Evaluation 8. Printing Unevenness Using the ink jet recording apparatus shown in FIG. 5, printing was performed on each of the following papers at 100% duty. Evaluation of printing method 1
Is the same as Ricoy 6200 paper (manufactured by Ricoh Co., Ltd.) Canon dry (manufactured by Canon Inc.) Using the obtained printed image, the reflection OD value was measured by Mach.
The measurement was performed using beth PCMII (manufactured by Macbeth). The OD values at arbitrary five points in the printed portion were measured, and the average value was obtained. This procedure was repeated five times, and the maximum value and the minimum value of the five average values were determined. If this difference is less than 0.5, there is no problem in practical use, and more preferably, it is less than 0.4. OD value difference is less than 0.3: A OD value difference is less than 0.3 to less than 0.4: B OD value difference is 0.4 or more: C The results are as shown in Table 5. .

Evaluation 9. Water resistance Using the ink jet recording apparatus shown in FIG. 5, water droplets are dropped on a printed portion of a printed matter printed on a special glossy film (manufactured by Seiko Epson Corporation) for an ink jet printer MJ-700V2C, and the state of the printed matter is visually observed. And evaluated. There is no change in the printed portion where the water droplet is dropped. : A A mark (water mark) is formed around the printed portion where the water droplet is dropped: B The periphery of the printed portion where the water droplet is dropped bleeds or floats: C The results are as shown in Table 5.

[0103]

[Table 5] Evaluation 5 Evaluation 6 Evaluation 7 Evaluation 8 Evaluation 9 Ink Reaction liquid black ink 1 Reaction liquid 1 A A 1.60 A A Black ink 1 Reaction liquid 2 B A 1.60 A A Blank ink 2 Reaction liquid 1 A A 1.60 A A Black ink 3 Reaction liquid 1 A A 1.63 A A Blank ink 4 Reaction liquid 1 FD 1.25 C C Black ink 5 Reaction liquid 1 DC 1.42--

Evaluation 10: Using a color bleed ink jet printer MJ-700V2C (manufactured by Seiko Epson Corporation), 100% of the recording paper was used.
After adhering the reaction solution to each paper at the duty, 100% duty
At ty, color inks (cyan, magenta, yellow) and black ink (characters) were simultaneously printed. The uneven color mixture at the boundary between the characters of the obtained printed matter was visually observed, and evaluated as follows. When there is no color mixture and the boundary is clear: A When color mixture occurs in a whisker shape: B When the color is mixed so that the outline of the character is not clear: NG The results are as shown in Table 6. Was.

[0105]

[Table 6] Evaluation 10 color ink set 1 black ink 1 reaction liquid 1 A

Production of Polymer Fine Particles 2 Makromol. Chem. 193, 2150 (19
92) The method described was followed. That is, 20 g of p-hydroxyacetophenone was heated at 120 ° C. for 1 hour in 100 ml of propionic anhydride. The obtained solution was cooled in an ice bath, and when the viscosity of the solution increased about 5 hours, dried boron trifluoride was quickly passed.

After leaving at 0 ° C. for 2 hours, 500 ml of a 1M aqueous sodium acetate solution was added, and the mixture was refluxed for 1 hour. After standing overnight, the organic product was separated. The water-soluble product was neutralized with 100 g of sodium bicarbonate and 500 m of ether
Extracted with l. Further, it was washed with 300 ml of water. The remaining ether extract was extracted with 500 ml of a 1.5 M aqueous sodium hydroxide solution, and the alkaline extract was neutralized with concentrated hydrochloric acid. Cool in the freezer for 2 hours to solidify the oil. The obtained crude product was purified by sublimation, dissolved in benzene, and recrystallized to obtain 1- (4-hydroxyphenyl) -1,3-pentanedione.

4.93 g of 1- (4-hydroxyphenyl) -1,3-pentanedione and 7.50 g of 4- (6
A mixture of-(acryloyloxyhexyloxy) benzoic acid and 6.86 g of N, N'-dicyclohexylcarbodiimide was stirred in 20 ml of ethyl acetate at 0 ° C for 1 hour and further at room temperature for 24 hours. The insoluble N, N'-dicyclohexylurea is filtered off, and the obtained filtrate is distilled to give 4- (1,3-dioxypentyl) phenyl-4- (6-acryloyloxyhexyloxy) benzoate. Obtained. 100 ml of distilled water and 0.1 g of potassium persulfate were added to a flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, and the internal temperature was heated to 70 ° C. while stirring and replacing with nitrogen. Then, distilled water 10
0 ml, 1.0 g of sodium dodecylbenzenesulfonate,
30 g of styrene, 55 of 2-ethylhexyl acrylate
g, 5 g of methacrylic acid, and 10 g of 4- (1,3-dioxypentyl) phenyl-4- (6-acryloyloxyhexyloxy) benzoate were mixed and stirred to prepare an emulsion. This was gradually dropped into the flask using a dropping funnel. The obtained emulsion was cooled to room temperature, and this emulsion was filtered with a 0.4 μm filter, and prepared with distilled water so that the concentration of the polymer fine particles became 30%. The obtained emulsion had a minimum film formation temperature of 20 ° C.

Black ink 11 5% by weight of carbon black MA7 (manufactured by Mitsubishi Chemical Corporation) and 1% by weight of a styrene-acrylic acid copolymer dispersant
And ion-exchanged water, and dispersed in a sand mill (manufactured by Yasukawa Seisakusho) for 2 hours together with glass beads (diameter 1.7 mm, 1.5 times the weight of the mixture), and then the glass beads were removed. A carbon black dispersion was prepared. Next, 0.1% by weight of ethylenediaminetetraacetic acid was dissolved in ion-exchanged water, and further 15% by weight of glycerin
Was added and the solution was stirred at room temperature for 20 minutes. This solution was gradually dropped into the carbon black dispersion stirred by a disperser, and sufficiently stirred. Further, 10% by weight of an aqueous polymer emulsion in which the polymer fine particles 2 were dispersed in water (concentration of the polymer fine particles: 3% by weight) was gradually dropped into the stirred solution, and the mixture was sufficiently stirred at room temperature. This was filtered through a 5 μm membrane filter to obtain an ink composition.

Black Ink 12 Carbon black MA7 (manufactured by Mitsubishi Chemical Corporation) 5% by weight, styrene-acrylic acid copolymer dispersant 1% by weight
And ion-exchanged water, and dispersed in a sand mill (manufactured by Yasukawa Seisakusho) for 2 hours together with glass beads (diameter 1.7 mm, 1.5 times the weight of the mixture), and then the glass beads were removed. A carbon black dispersion was prepared. Next, 0.1% by weight of ethylenediaminetetraacetic acid is dissolved in ion-exchanged water, and 15% by weight of glycerin and 7% by weight of maltitol are further added.
Stirred for 0 minutes. This solution was gradually dropped into the carbon black dispersion stirred with a disperser, and sufficiently stirred. Further, 10% by weight of an aqueous polymer emulsion in which the polymer fine particles 2 were dispersed in water (concentration of the polymer fine particles: 3% by weight) was gradually dropped into the stirred solution, and the mixture was sufficiently stirred at room temperature. This was filtered through a 5 μm membrane filter to obtain an ink composition.

Black ink 13 5% by weight of carbon black MA7 (manufactured by Mitsubishi Chemical Corporation) and 1% by weight of a styrene-acrylic acid copolymer dispersant
And ion-exchanged water, and dispersed in a sand mill (manufactured by Yasukawa Seisakusho) for 2 hours together with glass beads (diameter 1.7 mm, 1.5 times the weight of the mixture), and then the glass beads were removed. A carbon black dispersion was prepared. Next, 0.1% by weight of ethylenediaminetetraacetic acid was dissolved in ion-exchanged water, and further 15% by weight of glycerin, 15% by weight of glycerin, 2% by weight of 2-pyrrolidone,
Maltitol 6.3% by weight, sucrose 0.7% by weight,
0.1% by weight of potassium hydroxide, 0.9% by weight of triethanolamine and 2% by weight of ethyl alcohol were added, and the mixture was stirred at room temperature for 20 minutes. This solution was gradually dropped into the carbon black dispersion stirred with a disperser, and sufficiently stirred. Further, 10% by weight of an aqueous polymer emulsion in which the polymer fine particles 2 are dispersed in water is added to this stirred solution (polymer fine particle concentration: 3% by weight).
Was slowly added dropwise, followed by sufficient stirring at room temperature. This is 5μ
Then, the mixture was filtered with a m. membrane filter to obtain an ink composition. Ink Evaluation Test The above evaluation tests 1, 2, and 3 were carried out on the ink compositions. The results were as shown in the table below.

[Table 7] Evaluation 1 Evaluation 2 Evaluation 3 2 weeks 4 weeks Black ink 11 AA AA blank ink 12 AA AA black ink 13 AA AA Also, printing using two liquids combined with the above-mentioned reaction liquid 1 was performed and evaluated. Tests 5 and 6 were performed. The results were as shown in the table below.

[Table 8]

[Brief description of the drawings]

FIG. 1 shows an ink jet recording apparatus for carrying out a method according to the present invention, in which a recording head and an ink tank are independent, and an ink composition is supplied to the recording head by an ink tube. .

FIG. 2 is an enlarged view of a nozzle surface of a recording head, and 1c
Is a nozzle surface in which a plurality of nozzles from which the ink composition is discharged are provided in a line in the vertical direction.

FIG. 3 is a diagram illustrating inkjet recording using the recording head of FIG. 2; In the figure, reference numeral 31 denotes a print of the ink composition.

FIG. 4 is a view showing an ink jet recording apparatus for carrying out the method according to the present invention, in which a recording head and an ink tank are integrated.

FIG. 5 is a view showing an ink jet recording apparatus for carrying out the method according to the present invention, in which a recording head and an ink tank are independent, and an ink composition and a reaction liquid are supplied to the recording head by an ink tube. Supplied.

FIG. 6 is an enlarged view of a nozzle surface of a recording head,
b is the nozzle surface of the reaction liquid, and 51c is the nozzle surface of the ink composition.

FIG. 7 is a diagram illustrating ink jet recording using the recording head of FIG. In the figure, reference numeral 61 denotes a reaction liquid adhering area, and reference numeral 62 denotes a printing area where the ink is printed on the reaction liquid adhering thereto.

FIG. 8 is a diagram showing another aspect of the recording head, in which all the ejection nozzles are arranged in the horizontal direction.

FIG. 9 is a view showing another embodiment of the recording head, and shows ejection nozzles 61, 62, 63, and 64 of the ink composition.
And a buffer band 65 for preventing contact between the ink composition and the reaction liquid on the nozzle surface between the nozzle and the reaction liquid discharge nozzle 66.
Is provided.

FIG. 10 is a view showing an ink jet recording apparatus for carrying out the method according to the present invention, in which a recording head and an ink tank are integrated.

[Explanation of symbols]

 1,51 Recording head 2,52 Ink tank 3 Ink tube 22,23,24,25 Ink ejection nozzle 31 Printing area 21 Reaction liquid ejection nozzle 61 Reaction liquid adhesion area 62 Printing area

Claims (27)

[Claims] 1. An ink composition comprising a coloring material, water, a water-soluble organic solvent, and polymer fine particles, wherein the polymer fine particles have a ligand structure capable of forming a chelate with a metal ion. An ink composition comprising a polymer having a property of coagulating when forming a chelate with a metal ion. 2. The ligand structure capable of forming a chelate with a metal ion includes a β-diketone structure, a polyamine structure, an iminodiacetic acid structure, a sarcosine structure, an ethanol amino acid structure, a glycine structure, a xanthogenic acid structure, an amidoxime structure, and an amine. Structure, pyridine structure, imidazole structure,
Phosphonic acid structure, phosphinic acid structure, phosphoric acid structure, Schiff base structure, oxime structure, hydroxam structure, aminopolycarboxylic acid structure, thiol structure, polythioalcohol structure, 2-pyrrolidone structure, and 2-oxazolidone structure 2. The method of claim 1, which is selected.
3. The ink composition according to claim 1. 3. The ligand structure capable of forming a chelate with the metal ion is a structure represented by the following formula:
3. The ink composition according to claim 1. Embedded image (Wherein, P is a polymer structure part, and R represents an alkyl group or an aryl group) 4. The ink composition according to claim 1, wherein said polymer fine particles are made of a polymer having a film forming ability. 5. The ink composition according to claim 1, wherein the polymer fine particles have a minimum film forming temperature of 30 ° C. or less. 6. The ink composition according to claim 5, wherein said water-soluble organic solvent has a boiling point of 180 ° C. or higher. 7. The method according to claim 1, wherein the polymer fine particles are made of a polymer containing a thermoplastic polymer as a main component.
7. The ink composition according to any one of claims 1 to 6. 8. The thermoplastic polymer may be poly (meth) acrylate, polystyrene, (meth) acrylate-styrene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene- (meth) acryl. Acid ester copolymer, polybutadiene, polyisoprene,
Polyvinyl chloride, polyvinylidene chloride, poly (α-methylstyrene), styrene-butadiene copolymer, (meth) acrylic acid-styrene copolymer, styrene-maleic acid copolymer, styrene-itaconic acid copolymer, The ink composition according to claim 7, wherein the ink composition is selected from the group consisting of styrene-maleic acid ester copolymer, styrene-itaconic acid ester copolymer, polyester, polyurethane, polysiloxane, and polyamide. 9. The ink composition according to claim 1, wherein the polymer fine particles have a single particle structure. 10. The ink composition according to claim 9, wherein the polymer fine particles have a functional group of any of a carboxyl group, a sulfonic group, an amide group, an amino group, and a hydroxyl group. 11. The ink composition according to claim 1, wherein the polymer fine particles have a core-shell structure composed of a core portion and a shell layer surrounding the core portion. 12. The ink composition according to claim 12, wherein the shell layer has a functional group of any one of a carboxyl group, a sulfonic group, an amide group, an amino group, and a hydroxyl group. 13. The polymer fine particles having a particle size of 0.4 μm.
The ink composition according to claim 1, wherein: 14. The ink composition according to claim 1, wherein the coloring material is a dye or a pigment. 15. The ink composition according to claim 1, further comprising a sequestering agent. 16. The ink composition according to claim 15, wherein said water-soluble sequestering agent is an aminocarboxylic acid derivative or condensed phosphoric acid. 17. The water-soluble sequestering agent is ethylenediaminetetraacetic acid, iminodiacetic acid, nitriloacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, cyclohexane-1,2-diaminetetraacetic acid, N-hydroxyethylethylenediaminetriacetic acid. , Ethylene glycol diethyl etheramine tetraacetic acid,
17. The ink composition according to claim 16, wherein the ink composition is selected from the group consisting of ethylenediaminetetrapropionic acid, pyrophosphoric acid, and triphosphoric acid. 18. An ink jet recording method,
The ink composition according to claim 1. 19. A recording method for printing on a recording medium by attaching an ink composition, wherein the ink composition according to claim 1 is used as the ink composition. 20. An ink jet recording method for ejecting droplets of an ink composition and attaching the droplets to a recording medium to perform printing, wherein the ink composition is any one of claims 1 to 17. An ink jet recording method using the ink composition described in the above. 21. An ink composition according to any one of claims 1 to 17 and a reaction liquid containing a reactant that forms an aggregate when the ink composition comes into contact with the ink composition. A recording method, comprising a step of forming an image by causing the image to be formed. 22. The recording method according to claim 21, wherein the ink composition and / or the reaction liquid is attached to a recording medium by an ink jet recording method. 23. The recording method according to claim 22, wherein the reaction solution contains at least a reactant, a water-soluble organic solvent, and water. 24. The recording method according to claim 23, wherein the reactant is a polyvalent metal salt or polyallylamine or a derivative thereof. 25. A recording medium according to any one of claims 1 to 17, wherein the recording medium is preliminarily coated with a reactant which forms an aggregate upon contact with the ink composition according to any one of claims 1 to 18. A recording method, which comprises a step of forming an image by adhering the ink composition described in 1. above. 26. The reaction agent is a water-soluble polyvalent metal salt,
The recording method according to claim 25. 27. The recording method according to claim 26, wherein the ink composition is attached to a recording medium by an ink jet recording method.