JP2002019263A - Method for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for ink jet recording capable of printing an image not having a color stain or color bleeding irrespective of absorbability of a recording medium. SOLUTION: The method for ink jet recording comprises the steps of printing the recording medium, though the medium is any of a material for absorbing an ink composition and a reaction liquid and a substance for not substantially absorbing them, by using an ink composition set containing in combination at least a coloring material, anionic resin emulsion, water soluble organic solvent, aqueous ink composition constituted of water, a reaction agent for generating an aggregate when contacted with the aqueous ink composition and cationic resin emulsion. Thus, the medium can be printed with the image not having the color stain or the color bleeding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for printing by depositing an ink composition and a reaction liquid on a recording medium, wherein the recording medium is made of a substance absorbing the ink composition. Even if the recording medium is made of a substance that does not absorb, without using a special surface treatment on the recording medium, the same ink composition set is used to print an image without color blur or color bleed. About the method.

[0002]

2. Description of the Related Art An aqueous ink composition contains water as a main component,
Wetting agents and penetrants such as coloring components and glycerin,
Those containing additives such as surfactants and antibacterial and antifungal agents are generally used. As the recording medium used for the aqueous ink composition, one that can absorb the ink composition to some extent and allow the coloring material to permeate, such as paper and cloth, is used.

On the other hand, when printing or coating is performed on a recording medium that does not basically absorb an aqueous ink composition such as a synthetic resin or a metal, a solvent-based ink using an organic solvent (particularly lipophilic) is generally used. Compositions and paints have been used.

[0004] The reason is that solvent-based inks and coating compositions are composed of raw materials having a property of being insoluble in water, so that images printed using these materials are
It is excellent in fixability, abrasion resistance, and water resistance, and also excellent in productivity because the time required for drying and fixing to a recording medium is short.

[0005] However, organic solvents often show toxicity to animals and plants and have a large environmental load. Therefore, attention must be paid to its use and disposal, and there are many inconveniences in handling. In addition, when used in large quantities, it is necessary to install exhaust treatment equipment and the like.

[0006]

Therefore, even when printing or painting on a non-absorbable recording medium, the recording method using the aqueous ink composition has problems in terms of safety, environment, convenience of use and the like. Is considered preferable.

However, when printing is performed using a water-based ink on a non-absorptive recording medium, the affinity of the ink with the recording medium, that is, the so-called "wettability" becomes a serious problem.
If the wettability of the ink on the recording medium is low, the ink does not spread and becomes water-drop-like (repulsion occurs), so printing cannot be performed. Are mixed with each other (the occurrence of color bleed), and the ink spreads around the printing area (the occurrence of bleeding), which causes a problem in image formation.

In printing on a recording medium, it is also required that the coloring material component of the aqueous ink composition be firmly fixed on the recording medium.

Also, when printing on a recording medium that absorbs ink, fixing properties, abrasion resistance and durability are required to some extent. In particular, in order to obtain high-quality images using water-based inks, color bleeding and color bleeding must not occur during printing, and printing on recording media such as ordinary paper such as plain paper. In this case, it is necessary to prevent the phenomenon (feathering) in which the ink extends like a beard only along the paper fibers. Further, depending on the storage environment, water resistance may be required.

[0010] The above-mentioned image degradation factors will be described as follows.

(1) A phenomenon in which ink spreads around (color bleeding) (2) A phenomenon in which ink extends like a beard only along paper fibers (feathering) (3) Each color is mixed with each other Phenomenon in which color boundaries become unclear (color bleed) In order to prevent the occurrence of these image deterioration factors, solvent-based ink compositions and paints are generally used for non-absorbing recording media. In many cases, printing using a solvent-based ink composition or a paint is also performed on a recording medium in order to avoid the occurrence of the above-described image deterioration factors.

When printing is performed using an aqueous ink for applications requiring fixability, abrasion resistance, and water resistance, it is common to apply a special surface treatment to the recording medium in advance or a surface treatment after printing. It is being done. That is, in the former case, formation of an ink receiving layer on the printing surface of a recording medium and the like, and in the latter case, formation of a protective layer, for example, hot and cold lamination, formation of an overcoat layer, and the like are known as many known means.

However, these special surface treatments and printing surface protection treatments have the drawback that they inevitably complicate the printing apparatus and the printing process, increase the cost, and lower the productivity.

[0014]

Means for Solving the Problems When the present inventors performed printing on an absorptive recording medium by an ink jet recording method using two liquids composed of the ink composition and a reaction liquid, color bleeding and color A good image without bleed was obtained. In addition, it has been found that even when printing is performed on the non-absorbing recording medium using the same ink, a good image without color bleeding, feathering, and color bleed can be obtained.

It has also been found that these images have excellent fixing properties, abrasion resistance and water resistance despite being formed using an aqueous ink.

Accordingly, the present invention provides the use of the same ink composition for both absorptive and non-absorptive recording media.
It is an object of the present invention to provide a recording method capable of printing a good image without color bleed or color bleed.

The recording method according to the present invention provides an aqueous ink composition comprising a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water on a recording medium, and an agglomerate when contacted with the aqueous ink composition. A printing method in which printing is performed by adhering a reaction liquid containing a cationic resin emulsion and a reaction agent that causes the ink composition, and a step of adhering the reaction liquid on a recording medium, and applying the ink composition to a recording medium. And a step of recording an image by attaching it to the top.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Recording Method) The recording method according to the present invention includes a step of depositing a reaction solution described below on a recording medium and a step of recording an image by depositing an ink composition described later. It consists of

In the recording method according to the present invention, in the printing step, the coloring material is firmly fixed to the recording medium by adhering the ink composition and the reaction liquid to the recording medium, thereby preventing color bleeding and color bleeding. No good image quality can be obtained. The reason why such an effect occurs is not clear, but can be inferred as described below.

First, the contact between the ink composition and the reaction liquid on the recording medium causes the reaction agent and the cationic resin emulsion in the reaction liquid to disperse the colorant and the anionic resin emulsion in the ink composition. Is thought to destroy and agglomerate it. It is considered that the coloring material is fixed when these aggregates adhere to the surface of the recording medium.

Further, in the present invention, the ink composition comprises an anionic resin emulsion, and the reaction liquid comprises a cationic resin emulsion. It is expected that it is promoting.

Next, the reaction liquid and the ink composition are brought into contact with each other, and the printed surface of the image formed on the absorbent recording medium is
At the beginning of the contact, agglomeration composed of a coloring material and a resin emulsion and water or a water-soluble organic solvent separated from the agglomerate exist near the surface of the recording medium. Then, water or a water-soluble organic solvent, which is unnecessary for fixing the aggregates, permeates or evaporates into the recording medium and is removed from the surface, whereby the aggregates are fixed only on the recording medium, and the resin emulsion aggregates. Is promoted. The resin emulsion is united to form a resin film. In this resin film, the surface functional groups of the anionic resin emulsion and the surface functional groups of the cationic resin emulsion are electrostatically bonded, and in addition, these surface functional groups are formed with the hydrophilic groups present on the recording medium surface. It is presumed that hydrogen bonds more firmly to the surface of the recording medium and the image is fixed to the surface of the recording medium. Since this agglutination reaction is a quick reaction that occurs instantaneously, it is considered that the occurrence of color bleeding and color bleeding can be suppressed.

When an image is formed on the surface of a non-absorbing recording medium, it is preferable to promote the formation of a resin film by removing separated water or a water-soluble organic solvent by washing or the like. Note that the above mechanism is merely an assumption, and the present invention is not construed as being limited to this mechanism.

Further, since the resin film does not redissolve in water after the agglomerates are dried and has water resistance, even if the recording medium absorbs water, color bleeding and color bleeding may occur. There is no. As for the order in which the reaction liquid and the ink composition are adhered to the recording medium, a method in which the reaction liquid is adhered to the recording medium and then the ink composition is adhered to the recording medium, if there is no inconvenience in the process, and the reaction liquid and the ink Any of the methods for simultaneously depositing the composition can be selected.

Regarding the adhesion of the reaction liquid to the recording medium, there are either a method in which the reaction liquid is selectively applied only to the place where the ink composition is applied, and a method in which the reaction liquid is applied to the entire recording medium. There may be. The former is economical because the consumption of the reaction liquid can be suppressed to the minimum necessary amount, 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, the latter requires less precision of the position where the reaction liquid and the ink composition are adhered than the former, but causes a large amount of the reaction liquid to adhere to the entire recording medium, which is disadvantageous in terms of cost. Therefore, which method is adopted may be determined in consideration of the combination of the ink composition and the reaction liquid.

Means for adhering the reaction liquid to the recording medium and means for adhering the ink composition to the recording medium are described in the printing industry,
Recording methods commonly used in the coating industry are possible, for example, direct injection, spraying, coating, transfer, etc., but among them, only when printing is performed, printing is performed by discharging droplets onto a recording medium. The on-demand inkjet recording method performed is most preferable.

In the present invention, examples of the recording medium include those having water absorbency with respect to the ink composition, such as paper, cloth, nonwoven fabric, porous film, and polymer absorber. Specific examples of the absorptive recording medium to which the ink jet recording method according to the present invention can be applied include media based on paper, natural fibers and / or synthetic fibers such as cloth and nonwoven fabric, media processed with synthetic resin, inorganic and inorganic media. Media composed of a porous film composed of an organic material, media processed with a water-absorbing polymer, and recording media obtained by laminating these media, and recording media obtained by combining and combining two or more of these media. Can be

In the present invention, examples of the substrate which does not substantially absorb ink therein, that is, the non-absorbing recording medium include synthetic resin, rubber, metal, glass, ceramics, and the like. In order to add, a base material obtained by combining and combining a plurality of these materials can also be used. In addition, in order to further increase the strength and durability of the recording medium and to add functionality, a recording medium in which an absorbent substrate and a non-water-absorbing substrate are combined by means such as lamination or compounding is used. It is possible to use.

(Ink Composition) The ink composition used in the method according to the present invention comprises at least a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water. In the present invention, the ink composition means a black ink composition when performing monochrome printing, and a color ink composition when performing color printing, specifically, a yellow ink composition and a magenta ink composition. , Cyan ink compositions, and red, green, blue, orange, and violet ink compositions used for expanding the color reproduction range. In addition to these, black ink compositions may be used. Shall be considered.

(Resin Emulsion) The ink composition and reaction liquid of the present invention contain a resin emulsion. Here, the resin emulsion means a resin dispersion composition in which the continuous phase is water and the dispersed phase is the following resin component. As the resin component of the dispersed phase, acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acryl-styrene resin, butadiene resin, styrene resin, crosslinked acrylic resin, crosslinked styrene resin, Benzoguanamine resin, phenol resin, silicone resin, epoxy resin and the like can be mentioned. In the present invention, the anionic resin emulsion reacts with a reactant in a reaction solution described later, in particular, a polyvalent metal ion or a derivative of polyallylamine or polyallylamine, and a cationic resin emulsion to form a colorant on the surface of the recording medium. It has the effect of promoting sticking properties.

The term "anionic resin emulsion" as used herein means that the surface of the polymer particles in the disperse phase is dissociated in the aqueous phase and has a negatively charged functional group, carboxyl group, sulfone group, etc. It refers to a dispersion of polymer fine particles that has a potential and is relatively stably dispersed without being aggregated by its electrostatic repulsion.

On the other hand, the cationic resin emulsion has a quaternary ammonium,
Polymers that have functional groups such as pyridinium and quaternary phosphonium, dissociate in water, exhibit a positive zeta potential, and are relatively stable in dispersion without aggregation due to their electrostatic repulsion. Refers to a dispersion of fine particles.

According to a preferred embodiment of the present invention, these resin emulsions preferably have a minimum film forming temperature of room temperature or lower, and in fact, have a minimum film forming temperature of 20 ° C. or lower. preferable. If the film formation of the resin emulsion can be performed at room temperature or lower, no special heating means is required for the printed recording medium, and at room temperature or lower, the film formation on the printing surface automatically proceeds, and the coloring material is firmly attached to the recording medium. It is preferable because it adheres to the surface.

Here, the "minimum film forming temperature" means that a water-dispersible resin emulsion obtained by dispersing a resin emulsion in water is thinly cast on a metal plate such as aluminum and the temperature is raised. The minimum temperature at which a transparent continuous film is formed when heated. In a temperature range lower than the minimum film forming temperature, a white powder is formed. Further, according to a preferred embodiment of the present invention, the glass transition point of the resin emulsion is more preferably 10 ° C. or lower.

"Film-forming property" means that when a resin emulsion is dispersed in water to form a water-dispersible emulsion, a resin film is formed as the water component is evaporated. The ink composition to which the resin emulsion has been added has a property that a resin film is similarly formed when water or an aqueous organic solvent is evaporated. The resin film plays a role of firmly fixing the color material component in the ink composition to the surface of the recording medium. by this,
It is considered that an image having excellent durability and water resistance can be realized.

The addition amount of these resin emulsions is at least 5% by weight, preferably at least 8% by weight, based on the ink composition and the reaction liquid. And the resin emulsion is
The weight ratio of the colorant to the colorant is in the range of 1 to 20, more preferably 2 to 10.

The particle size of the resin emulsion is 100 nm.
Or less, more preferably about 5 to 80 nm.

According to a preferred embodiment of the present invention,
Resin emulsions have carboxyl groups on their surface.
And also have high reactivity with divalent metal salts
Is preferred. Specifically, the resin emulsion is
3 volumes of a water-dispersible emulsion of 0.1% by weight and 1 mol / l
When one volume of divalent metal salt aqueous solution
1 × 10 time when the transmittance of long 700nm light becomes 50% of the initial value
^FourSeconds or less (preferably 1 × 10^ThreeSeconds or less, more preferably 1 ×
Ten^TwoSeconds)) with reactivity with divalent metal salts
Is what you do. Anionic resin emulsions are divalent
When in contact with metal ions, they react and form suspended matter, causing the solution to permeate.
Decrease brightness. The amount of generated suspended matter is determined by the light transmittance.
And measure. Here, the divalent metal ion is Ca^{Two +}, C
u^{Two +}, Ni^{Two +}, Mg^{Two +}, Zn^{Two +}, Ba^{Two +}And form salt with it
The formed anion is Cl^-, NO_Three ^-, I^-, Br^-, ClO_Three ^-
And CH_ThreeCOO^-Is raised. Such high reactivity
Has a relatively large amount of anionic resin emulsion on its surface.
Attributed to having many carboxyl groups
Can be

An ink composition comprising an anionic resin emulsion having a large amount of carboxyl groups on its surface so as to exhibit high reactivity as described above is applied to a nozzle plate of a water-repellent ink jet recording head. And low affinity. Therefore, the ink composition, which has conventionally been a problem in ink compositions containing an anionic resin emulsion, wets the nozzle plate unevenly,
This is a great advantage because it is possible to effectively prevent the phenomenon that the ink droplets bend in flight and cause ejection failure. According to a preferred embodiment of the present invention, the contact angle of an aqueous emulsion obtained by dispersing an anionic resin emulsion in water at a concentration of 10% by weight on a Teflon (registered trademark) plate is preferably 70 ° or more. Further, the surface tension of a water-dispersible emulsion obtained by dispersing a resin emulsion in water at a concentration of 35% by weight is 40%.
Is preferably ³ N / m (20 ℃) or ^- × 10. By using the anionic resin emulsion as described above, the ink jet recording method can further prevent flight bending and achieve good printing.

Further, due to the dispersion stability caused by the high hydrophilicity of the resin emulsion surface, the ink composition has an advantage that excellent storage stability can be obtained.

According to another preferred embodiment of the present invention, the anionic resin emulsion comprises 1 to 10% by weight of a structure derived from an unsaturated vinyl monomer having a carboxyl group, and has a polymerizable double bond. Preferably, it has a structure crosslinked by two or more crosslinkable monomers, and contains 0.2 to 4% by weight of a structure derived from the crosslinkable monomer. Due to the use of a cross-linkable polymer obtained by copolymerizing cross-linkable monomers having two or more polymerizable double bonds, more preferably three or more at the time of polymerization and three-dimensionally cross-linking, the nozzle plate surface may be changed depending on the ink composition. Further, it becomes difficult to get wet, the bending of the flight can be further prevented, and the ejection stability can be further improved.

In the present invention, those having a single particle structure can be used as these resin emulsions. On the other hand, in the present invention, it is also possible to use a resin emulsion having a core-shell structure composed of a core portion and a shell portion surrounding the core portion. In the present invention, the “core-shell structure” means “a form in which two or more polymers having different compositions exist in a phase-separated state in a particle”. Therefore, not only a form in which the shell part completely covers the core part but also a part in which the core part is partially covered may be used. Also,
A part of the shell polymer may form a domain or the like in the core particle. Furthermore, a layer having a multilayer structure of three or more layers including layers having different compositions may be provided between the core and the shell.

According to a preferred embodiment of the present invention, it is preferable that the core of the anionic resin emulsion is formed of a resin having an epoxy group and the shell is formed of a resin having a carboxyl group. The epoxy group and the carboxyl group have the property of reacting with each other, but these two groups are present separately in the core and the shell. Due to the decrease in water or the water-soluble organic solvent, the resin emulsions unite and deform due to the pressure accompanying film formation.
As a result, the epoxy group of the core and the carboxyl group of the shell are combined to form a horizontal mesh structure. Thereby, there is obtained an advantage that a film having higher strength can be formed. The amount of the unsaturated vinyl monomer having an epoxy group is preferably from 1 to 10% by weight. In addition,
Here, the reaction between some epoxy groups and carboxyl groups before film formation is permissible in the present invention unless the film-forming ability is lost. In the present invention, the property that a reactive functional group coexists in such a resin emulsion and that the group reacts during film formation without adding a curing agent to form a network structure is referred to as "self-crosslinking property". Call.

The anionic resin emulsion used in the method according to the present invention can be obtained by known emulsion polymerization. That is, it can be obtained by emulsion polymerization of an unsaturated vinyl monomer (unsaturated vinyl monomer) in water in the presence of a polymerization catalyst and an emulsifier. As unsaturated vinyl monomers, acrylate monomers, methacrylate monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl cyanide compound monomers, halogenated monomers, which are generally used in emulsion polymerization, Examples include olefin monomers and diene monomers. Further, as specific examples, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, decyl acrylate, dodecyl acrylate Acrylates such as octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate and glycidyl acrylate; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n- Hexyl methacrylate, 2-ethylhexyl Methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate,
Methacrylates such as phenyl methacrylate, pendyl methacrylate, glycidyl methacrylate;
And vinyl esters such as vinyl acetate; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; halogenated monomers such as vinylidene chloride and vinyl chloride; styrene, 2-methylstyrene, vinyltoluene, tert-butylstyrene, and chlorostyrene. Aromatic vinyl monomers such as vinyl, anisole and vinyl naphthalene; olefins such as ethylene, propylene and isopropylene; dienes such as butadiene and chloroprene;
Vinyl monomers such as vinyl ether, vinyl ketone and vinyl pyrrolidone are exemplified. For a monomer having no carboxyl group, the use of an unsaturated vinyl monomer having a carboxyl group is essential.Preferred examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid. Among them, the use of methacrylic acid is preferred. Further, usable emulsifiers include anionic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof.

As described above, in the present invention,
It is preferable to have a structure in which a molecule derived from the above monomer is crosslinked by a crosslinking monomer having two or more polymerizable double bonds. Examples of crosslinkable monomers having two or more polymerizable double bonds include polyethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol diacrylate,
1,6-butylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,9-nonanediol diacrylate, polypropylene glycol diacrylate, 2,2 ′
Diacrylate compounds such as -bis (4-acryloxypropoxyoxyphenyl) propane and 2,2'-bis (4-acryloxydiethoxyphenyl) propane; trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane Triacrylate compounds such as triacrylate; tetraacrylate compounds such as ditrimethylol tetraacrylate, tetramethylol methane tetraacrylate and pentaerythritol tetraacrylate; hexaacrylate compounds such as dipentaerythritol hexaacrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triacrylate Ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene Recall dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,6
-Hexanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, polybutylene glycol dimethacrylate,
2,2'-bis (4-methacryloxydiethoxyphenyl)
Dimethacrylate compounds such as propane; trimethacrylate compounds such as trimethylolpropane trimethacrylate and trimethylolethanetrimethacrylate;
Examples include methylenebisacrylamide and divinylbenzene.

Further, by adding acrylamides or hydroxyl group-containing monomers in addition to the above-mentioned monomers, the printing stability can be further improved. Examples of acrylamides include acrylamide and N,
N'-dimethylacrylamide is exemplified. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate, and these may be used alone or in combination of two or more. Can be.

The cationic resin emulsion used in the method according to the present invention can also be obtained by known emulsion polymerization. That is, it can be obtained by emulsion polymerization of an unsaturated vinyl monomer in water in the presence of a polymerization catalyst and an emulsifier. Similarly, examples of the unsaturated vinyl monomer include acrylic acid ester monomers, methacrylic acid ester monomers, aromatic vinyl monomers, vinyl ester monomers, olefin monomers, and diene monomers commonly used in emulsion polymerization. Can be In addition, monomers used to introduce a cationic functional group on the surface include, for example, dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, dialkylaminoalkyl acrylamides, dialkylaminoalkyl methacrylamides, and the like. And quaternary ammonium salts.
Examples of usable emulsifiers include cationic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof.

As described above, in the present invention,
It is preferable to have a structure in which a molecule derived from the above monomer is crosslinked by a crosslinking monomer having two or more polymerizable double bonds. Examples of crosslinkable monomers having two or more polymerizable double bonds include diacrylate compounds, triacrylate compounds, tetraacrylate compounds, hexaacrylate compounds, dimethacrylate compounds, trimethacrylate compounds, methylenebisacrylamide, and divinylbenzene. No.

The resin emulsion having a core-shell structure is produced by a known method, generally by multi-stage emulsion polymerization or the like. For example, it can be manufactured by the method disclosed in JP-A-4-76004.
Examples of unsaturated vinyl monomers used for polymerization include:
Those mentioned above are also mentioned.

The introduction of an epoxy group into the above-mentioned core portion can be achieved by converting an unsaturated vinyl monomer having an epoxy group into
Glycidyl acrylate, glycidyl methacrylate,
Examples include a method of copolymerizing allyl glycidyl ether or the like with another unsaturated vinyl monomer, or a method of simultaneously adding an epoxy compound to prepare core particles by polymerizing one or more unsaturated vinyl monomers to form a composite. Can be. The former method is preferred from the viewpoint of easiness of polymerization and polymerization stability. In addition, an initiator, a surfactant, a molecular weight modifier, a neutralizing agent, and the like used in the emulsion polymerization may be used according to a conventional method.

In the present invention, the anionic resin emulsion may be mixed with other components of the ink composition.
Preferably, after being dispersed in water, it is preferably mixed with other components of the ink composition. In the present invention, the cationic resin emulsion may also be mixed with other components of the reaction solution. However, it is preferable that the emulsion is dispersed in water and then mixed with other components of the reaction solution. In addition, when these resin emulsions are added to the ink composition and the reaction liquid, they are preferably used as the last added components in the ink manufacturing process.

According to a preferred embodiment of the present invention, the mixing ratio of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1. When the amount of the surfactant used is in the above range, better water resistance and permeability of the ink can be obtained. Although the surfactant is not particularly limited, preferred examples thereof include anionic surfactants (for example, sodium dodecyl benzene sulfonate, sodium lauryl sulfate, ammonium salt of polyoxyethylene alkyl ether sulfate, etc.), and cationic surfactants (for example, , Dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, dihexadecyldimethylammonium bromide, etc., nonionic (nonionic) surfactants (for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan) Fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc.), amphoteric surfactant Agent (e.g., betaine, lauryl sulfobetaine, octyl sulfo betaine, 1- (3-
Sulfopropyl) pyridinium betaine and the like, and these can be used alone or in combination of two or more. In addition, acetylene glycol (Olefin
Y, and Surfinol 82, 104, 440, 465, and
485 (both Air Products and Chemicals Inc.
)) Can also be used.

The proportion of the resin and water as the disperse phase component is suitably in the range of 60 to 400 parts by weight of water, preferably 100 to 200 parts by weight based on 100 parts by weight of the resin.

In the present invention, known resin emulsions can be used as the resin emulsion satisfying the above conditions. For example, JP-B-62-1426, JP-A-3-5
Resin emulsions described in JP-A-6573, JP-A-3-796178, JP-A-3-160068, JP-A-4-18462 and the like can be used.

(Coloring Material) The coloring material contained in the ink composition used in the method of the present invention may be either a dye or a pigment, but may be a pigment in terms of light resistance and water resistance. preferable. It is also possible to use a pigment and a dye together.

The pigment is not particularly limited, and either an inorganic pigment or an organic pigment can be used. As inorganic pigments, in addition to titanium oxide and iron oxide, contact method,
Carbon black produced by a known method such as a furnace method or a thermal method can be used. Examples of the organic pigment include azo dyes (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, dioxazine Pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc., dye chelates (eg, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.

Particularly, carbon black used as black ink includes No. 2300, No. 900 and MCF 8 manufactured by Mitsubishi Chemical Corporation.
8, No.33, No.40, No.45, No.52, MA7, MA8, MA100, N
o.2200B etc., Raven 5750, Raven 525 manufactured by Columbia
0, Raven 5000, Raven 3500, Raven 1255, Raven 700 etc. are Cabot's Regal 400R, Regal 330R, Regal
660R, Mogul L, Monarch 700, Monarch 800, Monarch
880, Monarch 900, Monarch 1000, Monarch 1100, Mona
rch 1300, Monarch 1400 etc. are Color Bl made by Degussa
ack FW1, Color Black FW2, Color Black FW2V, Color
Black FW18, Color Black FW200, Color Black S150, C
olor Black S160, Color Black S170, Printex 35, Pr
intex U, Printex V, Printex 140U, Special Black
6, Special Black 5, Special Black 4A, Special Blac
k 4 etc. can be used. Pigments used in the yellow ink include CI Pigment Yellow 1, CI Pigment Yellow
2, CI Pigment Yellow 3, ClPigment Yellow 12,
CIPigment Yellow 13, CIPigment Yellow 14C, C.I.
I. Pigment Yellow 16, CI Pigment Yellow 17, CIPI
gment Yellow 73, CI Pigment Yellow 74, CI Pigmen
t Yellow 75, CI Pigment Yellow 83, CI Pigment Ye
llow 93, CI Pigment Yellow 95, CI Pigment Yellow
97, CI Pigment Yellow 98, CI Pigment Yellow 11
4, CI PigmentYellow 128, CI Pigment Yellow 129,
CI Pigment Yellow 151, CI Pigment Yellow 154 and the like. Further, as pigments used in magenta ink, CI Pigment Red 5, CI Pigment Red 7, C.I.
I. Pigment Red 12, CI Pigment Red 48 (Ca), CIPi
gment Red 4 (Mn), CI Pigment Red 57 (Ca), CIP
igment Red 57: 1, CI Pigment Red 112, CI Pigment
Red 123, CIigment Red168, CIigment Red 18
4, CI Pigment Red 202 and the like. Pigments used in cyan ink include CI Pigment Blue 1, CI
Pigment Blue 2, CI Pigment Blue 3, CI Pigment Bl
ue 15: 3, CIPigment Blue 15:34, CIPigment Blu
e 16, CI Pigment Blue 22, CI Pigment Blue 60,
CIVat Blue 4 and CIVat Blue 60.

The particle size of the pigment is preferably 10 μm or less, more preferably 0.1 μm or less.

The pigment is preferably added to the ink as a pigment dispersion dispersed in an aqueous medium with a dispersant. As a dispersant used for preparing a pigment dispersion, a dispersant generally used for preparing a pigment dispersion, for example, a polymer dispersant or a surfactant can be used.
It will be apparent to those skilled in the art that the surfactant contained in this pigment dispersion will also function as the surfactant of the ink composition. Preferred examples of the polymer dispersant include natural polymers, and specific examples thereof include glue,
Proteins such as gelatin, casein, albumin;
Natural gums such as gum arabic and tragacanth; glucosides such as saponin; alginic acid derivatives such as alginic acid and propylene glycol alginate, triethanolamine alginate and ammonium alginate; methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, ethylhydroxycellulose And the like. Further, preferred examples of the polymer dispersant include synthetic polymers, such as polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, and vinyl acetate-acryl. Acrylic resins such as acid ester copolymers and acrylic acid-acrylic acid ester copolymers; styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, sterene-methacrylic acid-acrylic acid ester copolymers, styrene -Α-methylsterene-acrylic acid copolymer, sterene-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 acetic acid Vinyl acetate copolymers such as vinyl-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 polymers 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 coloring material in the ink composition is 0.1%.
It is preferably about 5 to 25% by weight, more preferably about 2 to 15% by weight. (Water, water-soluble organic solvent, surfactant, and other components) The solvent of the ink composition used in the method according to the present invention contains water and a water-soluble organic solvent as main components.

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

Among them, it is preferable to use a water-soluble organic solvent having a boiling point of 180 ° C. or higher. Use of a water-soluble organic solvent having a boiling point of 180 ° C. or higher results in water retention and wettability of the ink composition. As a result, even if the ink composition is stored for a long period of time, there is no aggregation or increase in viscosity of the coloring material, and excellent storage stability can be realized. In addition, open state (state in contact with air at room temperature)
Ink composition that can maintain fluidity and redispersibility for a long time even if left as is.

Furthermore, in the ink jet recording method, high ejection stability can be obtained without clogging of nozzles at the time of restart during printing or after interruption of printing.

Examples of the water-soluble organic solvent having a boiling point of 180 ° C. or higher include ethylene glycol (boiling point: 197 ° C .; hereinafter, the boiling point is shown in parentheses), 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-1,2
3-hexanediol (243 ° C), 2-methyl-2,4-pentanediol (197 ° C), N-methyl-2-pyrrolidone (202 ° C), 1,3-dimethyl-2-imitazolidinone (25 ° C)
7-260 ° C), 2-pyrrolidone (245 ° C), glycerin (29
0 ° 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), and diethylene glycol monomethyl ether (194 ° C). Those having a boiling point of 200 ° C. or higher are preferred. These water-soluble organic solvents can be used alone or in combination of two or more.

The content of these water-soluble organic solvents is preferably about 0.5 to 40% by weight based on the ink composition.
More preferably, it is 2 to 20% by weight.

According to a preferred embodiment of the present invention, the ink composition used in the present invention contains various surfactants in order to improve the affinity for a recording medium (so-called “wettability”). It can be. The ink composition used in the method according to the present invention may further contain a surfactant. As examples of the surfactant, the same surfactant as that used in the preparation of the resin emulsion described above can be suitably used. For example, anionic surfactants (for example, sodium dodecyl benzene sulfonate, sodium lauryl sulfate, ammonium salt of polyoxyethylene alkyl ether sulfate, etc.), cationic surfactants (for example, dodecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride) , Dihexadecyldimethylammonium bromide), nonionic (nonionic) surfactants (eg, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene Oxyethylene alkylamines, polyoxyethylene alkylamides, etc.), amphoteric surfactants (eg, betaine, lauryl sulfobeta) Emissions, octyl sulfobetaine, such as 1- (3-sulfopropyl) pyridinium betaine) and the like,
These can be used alone or in combination of two or more. Also, acetylene glycol (Olefin Y and Surfynol 82, 104, 440, 465, and 485)
(All manufactured by AirProducts and Chemicals Inc.)). By suitably combining these, it is possible to control the wettability of the ink composition, but two kinds of surfactants having functional groups of mutually different polarities, that is, an anionic surfactant and a cationic surfactant It is not preferable to add a combination of a surfactant, an amphoteric surfactant and an anionic surfactant, or a combination of an amphoteric surfactant and a cationic surfactant to the same ink. This is because the anionic and cationic functional groups of each surfactant molecule associate with each other due to electrostatic attraction, so that the viscosity of the ink composition increases and the dispersed state of the pigment particles is destroyed. Because In addition, it is not preferable to add a surfactant having a polarity opposite to the charge of the pigment particles in the dispersed state, because the zeta potential of the pigment particles in the dispersed state is neutralized by electrostatic repulsion. This is because the particles lose cohesion and aggregate. Therefore, it is not preferable to add a cationic surfactant to a pigment ink containing pigment particles dispersed by negative charging, and similarly, to add an anionic surfactant to a positively charged pigment dispersed ink. Is also not preferred.

And according to a preferred embodiment of the present invention, the ink composition used in the method according to the present invention can comprise a sugar, a tertiary amine, an alkali metal hydroxide, or an alginic acid derivative. Addition of sugar and tertiary amine results in wetting. The addition of the tertiary amine and the alkali metal hydroxide stabilizes the dispersion of the colorant and the resin emulsion in the ink composition in the ink.

Examples of sugars include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldone. 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, as the derivatives of these saccharides, reducing sugars of the aforementioned saccharides [(for example,
Sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n
= Represents an integer of 2 to 5)], an oxidized sugar (for example,
Aldonic acid, uronic acid, etc.), amino acids, thiosugars and the like. Particularly, sugar alcohols are preferable, and specific examples include maltitol and sorbitol. The added amount of these saccharides is preferably about 0.1 to 40% by weight, more preferably about 1 to 30% by weight.

Examples of the tertiary amine include trimethylamine, triethylamine, triethanolamine, dimethylethanolamine, diethylethanolamine, triisopropenolamine, butyldiethanolamine and the like. These may be used alone or in combination. The amount of these tertiary amines added to the ink composition is
It is preferably about 0.1 to 10% by weight, more preferably 0.5 to 10% by weight.
5% by weight.

Examples of the alkali metal hydroxide include potassium hydroxide, sodium hydroxide and lithium hydroxide.
The addition amount is preferably about 0.01 to 5% by weight, more preferably about 0.05 to 3% by weight.

Preferred examples of the alginic acid derivative include:
Alginic acid alkali metal salts (eg, sodium salt, potassium salt), alginic acid organic salts (eg, triethanolamine salt), and alginic acid ammonium salts are exemplified. The amount of the alginic acid derivative added to the ink composition is preferably about 0.01 to 1% by weight, and more preferably about 0.05 to 0.5% by weight.

The reason why a good image can be obtained by adding the alginic acid derivative is not clear, but the polyvalent metal salt present in the reaction solution reacts with the alginic acid derivative in the ink composition to change the dispersion state of the coloring material. This is considered to be caused by promoting the fixing of the color material to the recording medium.

In addition, it is possible to add a pH adjuster, a preservative, a fungicide and the like to the ink composition as needed in order to improve the storage stability.

(Reaction liquid) The reaction liquid used in the present invention comprises a reactant and a cationic resin emulsion, and the term "reactant" herein means a pigment and / or an anionic resin emulsion in the ink composition. Can be destroyed and aggregated. Examples include polyvalent metal salts, polyamines, and polyamine derivatives. Further, the cationic resin emulsion also has a property of reacting with and coagulating with the anionic resin emulsion by electrostatic interaction.

The polyvalent metal salt that can be used in the reaction solution is composed of polyvalent metal ions having two or more valences and anions bonded to these polyvalent metal ions, and is soluble in water. Specific examples of the polyvalent metal ion, Ca ^{2 +,} C
divalent metal ions such as u ^{2 +} , Ni ^{2 +} , Mg ^{2 +} , Zn ^{2 +} , Ba ^{2 +} , Al
Trivalent metal ions such as ³⁺ , Fe ³⁺ and Cr ³⁺ can be mentioned. Examples of anions include Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ and CH ₃
COO ^-, and the like.

In particular, a metal salt composed of Ca ²⁺ or Mg ²⁺ gives favorable results from the two viewpoints of the pH of the reaction solution and the quality of the obtained printed matter.

The concentration of these polyvalent metal salts 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, and more preferably 5 to 40% by weight. About 25% by weight.

According to a preferred embodiment of the present invention, the polyvalent metal salt contained in the reaction solution contains a divalent or higher polyvalent metal ion,
It is composed of nitrate ions or carboxylate ions bound to these polyvalent metal ions, and is soluble in water.
Particularly, nitrate ion is preferable.

The polyallylamine and the polyallylamine derivative which can be used in the reaction solution are cationic polymers which are soluble in water and are positively charged in water.

In addition to the above, a polymer obtained by copolymerizing allylamine and diallylamine or a copolymer of diallylmethylammonium chloride and sulfur dioxide can be used.

The content of these polyallylamine and polyallylamine derivative is preferably 0.5 to 10% by weight of the reaction solution.

According to a preferred embodiment of the present invention, the reaction solution may contain a polyol. Here, the polyol has a vapor pressure at 20 ° C. of 0.01 mmHg or less, and the amount of the polyol added is 1 or more by weight relative to the polyvalent metal salt, preferably 1.0 to 5.0. . Further, according to a preferred embodiment of the present invention, the amount of the polyol added to the reaction solution is preferably at least 10% by weight, more preferably about 10 to 30% by weight.

Preferred specific examples of the polyol include polyhydric alcohols such as glycerin, diethylene glycol, triethylene glycol, 1,5-pentanediol, and 1,4-butanediol. further,
Preferred specific examples of polyols include sugars such as monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides)
And polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucosyl, sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like. These polyols may be added alone or as a mixture of two or more. When it is added as a mixture of two or more, the amount added is a total of 1 or more by weight to the polyvalent metal salt.

According to a preferred embodiment of the present invention, the reaction solution contains a wetting agent comprising a high-boiling organic solvent. The high-boiling organic solvent prevents the reaction solution from drying. Preferable examples of the high boiling point organic solvent partially overlap with the above-mentioned polyols, but include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, and thioglycol. Polyhydric alcohols such as hexylene glycol, glycerin, trimethylolethane, and trimethylolpropane; ethylene glycol monoethyl ether;
Alkyl ethers of polyhydric alcohols such as ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and triethylene glycol monobutyl ether; 2-pyrrolidone , N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like. According to a preferred embodiment of the present invention, the reaction solution preferably contains a combination of triethylene glycol monobutyl ether and glycerin.

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, based on the reaction solution.

According to a preferred embodiment of the present invention, the reaction solution may contain a low-boiling organic solvent. Preferred examples of the low boiling point organic solvent include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, 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 low boiling organic solvent added
It is preferably 0.5 to 10% by weight, more preferably 1.5 to 6% by weight.

According to a preferred embodiment of the present invention, the reaction solution may contain a substance having a surfactant effect. Examples of these compounds include various surfactants such as anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, alcohols such as methanol, ethanol, and iso-propyl alcohol, ethylene glycol. Lower alkyl ethers of polyhydric alcohols such as monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, diprohylene glycol monobutyl ether, etc., and these should be added to the reaction solution. Thus, it becomes possible to improve the permeability and affinity (“wetability”) of the reaction liquid with respect to the recording medium.

Representative examples of the above compounds include Orfin Y, Surfynol 82, Surfynol 440, Surfynol 465, and Surfynol 485 (all manufactured by Air Products and Chemicals Inc.). These may be used alone or in combination of two or more.

According to a preferred embodiment of the present invention, the reaction solution is
It comprises triethanolamine for pH adjustment. When triethanolamine is added, the amount added is
About 0 to 2.0% by weight is preferable.

The reaction liquid may be colored by adding the coloring material or extender described in the section of the ink composition described later, and may have the function of the ink composition.

[0091]

The embodiments of the present invention will be described below, but these examples explain the contents of the present invention and do not limit the scope of the present invention.

Example 1 Preparation of Anionic Resin Emulsion Dispersion 100 ml of distilled water and 0.1 g of potassium persulfate were added to a flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel. While replacing, the internal temperature was heated to 70 ° C. Next, 100 ml of distilled water, 1.0 g of sodium dodecylbenzenesulfonate, 30 g of styrene, 55 g of 2-ethylhexyl acrylate, and 5 g of methacrylic acid were 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 resin emulsion became 30%. The obtained emulsion had a minimum film-forming temperature of about 20 ° C., and exhibited a property of aggregation when mixed with a reaction solution described later.

Preparation of Cationic Resin Emulsion Dispersion 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. The temperature was heated to 75 ° C. Next, 260 ml of distilled water, 2.0 g of nonionic surfactant Surfynol-465, 100 g of methacryloxyethyltrimethylammonium chloride, 30 g of 2-hydroxyethyl acrylate, 100 g of acrylonitrile, and 70 g of butyl acrylate were stirred to prepare a mixture. This was gradually dropped into the flask over 3 hours using a dropping funnel. After the obtained emulsion was cooled to room temperature and neutralized with potassium hydroxide, this emulsion was filtered with a 0.4 μm filter, and prepared with distilled water so that the concentration of the resin emulsion became 30%. .

Preparation of Ink Composition An ink composition having the following composition was prepared. Preparation was performed in the following manner. A pigment, a dispersant, and water are mixed and mixed in a sand mill (manufactured by Yasukawa Seisakusho).
1.7 mm, 1.5 times (weight) of the mixture) for 2 hours. Thereafter, the glass beads were removed to prepare a pigment dispersion. Next, a solvent excluding the pigment and the dispersing agent was mixed, and the ink dispersion was gradually dropped while stirring the pigment dispersion liquid as an ink solvent, followed by stirring at room temperature for 20 minutes. Thereafter, the anionic resin emulsion dispersion was gradually added dropwise, and the mixture was stirred and mixed at room temperature for 10 minutes, and then filtered through a 5 μm membrane filter to obtain an ink composition for inkjet recording.

Black pigment ink composition Carbon black MA-7 (coloring material, manufactured by Mitsubishi Chemical Corporation) 5% by weight (hereinafter abbreviated as wt)% styrene-acrylic acid copolymer (dispersant) 1% by weight anionic resin emulsion ( 10 wt% Glycerin 10 wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1 wt% Ion exchange water Remaining color ink set Cyan pigment ink CI Pigment cyan 15: 3 (color material) 2 wt % Styrene-acrylic acid copolymer (dispersant) 1 wt% Anionic resin emulsion (as solid content) 10 wt% Diethylene glycol 10 wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1 wt% ion exchange water Remaining amount Magenta pigment ink CI Pigment Red 122 (coloring material) 3wt% styrene-acrylic acid copolymer (dispersant) 1wt% ani Resin emulsion (as solid content) 20wt% glycerin 5wt% diethylene glycol 5wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1wt% ion exchange water Remaining yellow pigment ink CI Pigment Yellow 74 (color Material) 3.5wt% styrene-acrylic acid copolymer (dispersant) 1wt% Anionic resin emulsion (as solid content) 15wt% glyceric 8wt% Surfynol 465 (surfactant, Air Product and Chemicals, Inc) 1wt % Deionized water remaining amount Preparation of reaction solution A reaction solution was prepared according to the following composition. Preparation was performed in the following manner. Magnesium nitrate was dissolved in ion-exchanged water, and glycerin and triethylene glycol monobutyl ether were added in this order while stirring and mixing using a magnetic stirrer. Next, the cationic resin emulsion dispersion was gradually added dropwise, and the mixture was stirred and mixed at room temperature for 10 minutes, and then filtered with a 5 μm membrane filter to obtain a reaction liquid.

Reaction liquid Magnesium nitrate hexahydrate 25 wt% cationic resin emulsion (as solid content) 10 wt% triethylene glycol monobutyl ether 5 wt% glycerin 10 wt% ion exchange water Remaining recording medium 1: plain paper Xerox P ( Recording medium 2: Plain paper Xerox 4024 (Xerox Corporation) Recording medium 3: PET film Xerox Film <No frame> A4 (Fuji Xerox Corporation) Recording medium 4: Aluminum plate Thickness 0.3 (mm) Recording medium 5: Vinyl chloride sheet Viewcal 900 (manufactured by Lintec Corporation) Recording medium 6: Polyolefin sheet YUPO FPG 110 (Oji Yuka Synthetic Paper Co., Ltd.) (Example 2) Black pigment ink composition carbon Black MA-7 (color material, manufactured by Mitsubishi Chemical Corporation) 5% by weight (hereinafter abbreviated as wt)% Styrene-acrylic acid copolymer (dispersant) 1% by weight Anionic resin emulsion John (as solid content) 15 wt% glycerin 10 wt% Surfynol 465 (surfactant) 1 wt% lauryl sulfobetaine (amphoteric surfactant) 0.5 wt% ion exchange water Remaining color pigment ink set Cyan pigment ink CI Pigment cyan 15 : 3 (coloring material) 2wt% styrene-acrylic acid copolymer (dispersant) 1wt% anionic resin emulsion (as solid content) 15wt% diethylene glycol 10wt% Surfynol 465 (system surfactant) 1wt% ion exchange water Remaining amount Magenta pigment ink CI Pigment Red 122 (coloring material) 3 wt% styrene-acrylic acid copolymer (dispersant) 1 wt% Anionic resin emulsion (as solid content concentration) 15 wt% glycerin 5 wt% diethylene glycol 5 wt% Surfynol 465 ( (Surfactant) 1wt% ion exchange water remaining yellow pigment ink CI Gment Yellow 74 (colorant) 3.5 wt% styrene-acrylic acid copolymer (dispersant) 1 wt% Anionic resin emulsion (as solid content) 15 wt% glycerin 8 wt% Surfynol 465 (surfactant) 1 wt% ion exchange Water remaining amount The ink composition was changed to the above composition, and the other parts were printed on the recording media 1 to 6 in the same manner as in Example 1, and the same evaluation was performed.

(Comparative Example 1) Black dye ink composition Project Fast Black 2 (coloring material, manufactured by AVECIA) 3.5 wt% glycerin 10 wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1 wt% Ethylene glycol monobutyl ether 7 wt% ion-exchanged water Remaining amount The above dye was added to the ink solvent and dissolved by stirring at room temperature for 20 minutes. And filtered with a 5μm membrane filter,
This was used as an ink composition for inkjet recording. Only the black ink composition was changed to the above composition, and printing was performed on recording media 1 to 6 in the same manner as in Example 1 without using a reaction liquid, and evaluation was performed in the same manner.

Comparative Example 2 Black Pigment Ink Composition Carbon Black MA-7 (Coloring Material, manufactured by Mitsubishi Chemical Corporation) 5% by weight (hereinafter abbreviated as wt)% Styrene-acrylic acid copolymer (Dispersant) 1% by weight Glycerin 10wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1wt% ion exchange water Remaining color ink set Cyan pigment ink CI Pigment Cyan 15: 3 (coloring material) 2wt% styrene-acrylic acid copolymer Combined (dispersant) 1 wt% Diethylene glycol 10 wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc) 1 wt% Ion exchange water Remaining amount Magenta pigment ink CI Pigment Red 122 (coloring material) 3 wt% styrene-acrylic acid Copolymer (dispersant) 1wt% glycerin 5wt% diethylene glycol 5wt% Surfynol 465 (surfactant, manufactured by Air Product and Chemicals, Inc 1 wt% Ion-exchanged water Remaining amount Yellow pigment ink CI Pigment Yellow 74 (colorant) 3.5 wt% styrene-acrylic acid copolymer (dispersant) 1 wt% glycerin 8 wt% Surfynol 465 (surfactant, Air Product and Chemicals, Inc.) 1 wt% ion-exchanged water remaining amount The composition of the ink set was changed to the above, printing was performed on recording media 1 to 3 in the same manner as in Example 1 without using a reaction solution, and the same evaluation was performed. did.

Comparative Example 3 Printing was performed on recording media 1 to 3 in the same manner as in Example 1 except that the reaction solution was not used, and the same evaluation was performed.

Comparative Example 4 Using the same ink set as in Comparative Example 2 and using the same reaction solution as in Example 1, printing was performed on recording media 1, 2, and 3 in the same manner as in Example 1. The same evaluation was performed (evaluation test). Examples were given by combinations shown in Table 1 below. The printed matter targeted for the following evaluation was prepared by printing the ink composition and the reaction liquid of the above example on a recording medium at normal temperature and normal pressure using an inkjet printer EM-900C manufactured by Seiko Epson Corporation. I got it. Printing was performed by simultaneously discharging the reaction liquid, the black ink, and the color ink onto the recording medium. Thereafter, the recording medium was air-dried, and the following evaluation was performed. Evaluation item 1: Evaluation of color bleeding after printing The printed matter was visually evaluated for bleeding immediately after printing according to the following criteria. A: A good image without bleeding was obtained. B: Slight bleeding occurred. C: Mustache-like bleeding occurred. D: Bleeding occurred so that the color boundary was not clear. Evaluation item 2: Evaluation of color bleed after printing The printed matter was visually evaluated for uneven color mixture at color boundaries according to the following criteria. A: A good image without color mixture was obtained. B: Color mixture slightly occurred. C: Color mixing was observed. D: Color mixing occurred so that the boundaries of the colors were not clear. Evaluation item 3: Feathering evaluation after printing The printed matter was visually evaluated for the presence of mustache-like bleeding according to the following criteria. A: A good image without whisker-like bleeding was obtained. B: Whisker-like oozing slightly occurred. C: A whisker-like bleeding was observed. -: Could not be evaluated due to the effects of bleeding and color bleeding. Evaluation item 4: Comprehensive evaluation The printed matter was naturally dried sufficiently. The recording media 3 to 6 were sufficiently washed with ion-exchanged water and then air-dried sufficiently, and then visually evaluated. The results were as shown in Table 1 below.

[0101]

[Table 1]

[0102]

As described above, regardless of whether the recording medium is a material that absorbs the ink composition and the reaction liquid, or a material that does not substantially absorb the ink composition, a pigment, an anionic resin emulsion, a water-soluble organic solvent, Using an aqueous ink composition composed of water, and an ink composition set that combines a reaction liquid containing a cationic resin emulsion and a reactant that forms an aggregate when contacted with the aqueous ink composition According to a recording method for printing on a recording medium, it is possible to print an image without color blur or color bleed on these recording media.

Continued on the front page F-term (reference) 2C056 FC01 2H086 BA02 BA15 BA18 BA19 BA21 BA22 BA23 BA52 BA53 BA55 BA59 BA62

Claims (13)

[Claims] 1. An aqueous ink composition comprising at least a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water, a reactant that forms an aggregate when contacted with the aqueous ink composition, and a cationic agent A recording method using an ink set in which a reaction liquid containing a resin emulsion is combined. 2. The coloring material of the ink composition is a pigment,
The recording method according to claim 1. 3. The recording method according to claim 1, wherein the amount of the anionic resin emulsion used in the ink composition is 1 to 30% by weight based on the ink composition. . 4. The recording method according to claim 1, wherein the ink composition contains an anionic surfactant or an amphoteric surfactant. 5. The ink composition contains a surfactant,
The recording method according to any one of claims 1 to 4, wherein an anionic surfactant or an amphoteric surfactant is used in combination with a nonionic surfactant. 6. The recording method according to claim 1, wherein the reactant is a polyvalent metal salt, polyallylamine, or a derivative of polyallylamine. 7. The recording method according to claim 1, wherein the amount of the cationic resin emulsion used in the reaction solution is 1 to 30% by weight based on the reaction solution. 8. A recording medium used in the recording method,
A medium for absorbing an aqueous ink composition and a reaction liquid, such as paper, cloth, nonwoven fabric, porous film, and polymer absorber.
8. The recording method according to any one of items 7 to 7. 9. The recording according to claim 1, wherein the recording medium is a medium that does not substantially absorb an aqueous ink composition such as metal, ceramics, rubber, and synthetic resin and a reaction liquid. Method. 10. The recording medium according to claim 1, wherein the recording medium has a laminated structure composed of a single component such as paper, cloth, nonwoven fabric, porous film, polymer absorber, metal, ceramics, rubber, and synthetic resin. The recording method according to any one of claims 1 to 7. 11. The recording medium according to claim 1, wherein the recording medium has a laminated structure in which two or more materials such as paper, cloth, nonwoven fabric, porous film, polymer absorber, metal, ceramics, rubber, and synthetic resin are combined. Item 8. The recording method according to any one of Items 1 to 7. 12. The recording according to claim 1, wherein the step of depositing ink composition droplets on the recording medium is performed simultaneously with the step of depositing the reaction liquid on the recording medium. Method. 13. The ink-jet method according to claim 1, wherein the step of depositing a droplet of the ink composition on the recording medium or the step of depositing the reaction liquid on the recording medium is performed by ejecting the droplet and attaching the ink to the recording medium to perform printing. It is a recording method, claim 1-
13. The recording method according to any one of the above items 12.