JP2014111374A - Inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording method by which an image free of color blur or color bleeding can be printed regardless of the absorptivity of a recording medium.SOLUTION: The recording method is carried out by using the following ink composition set to print a recording medium regardless of the conditions of the recording medium that medium is made of a material which absorbs or substantially does not absorb an ink composition and a reaction solution. The ink composition set is a combination of an aqueous ink composition comprising at least a coloring material, an anionic resin emulsion, a water-soluble organic solvent and water, and a reaction solution comprising a reaction agent that produces an aggregate when brought into contact with the aqueous ink composition, and a cationic resin emulsion. By this method, an image free of color blur or color bleeding can be printed on the recording medium.

Description

  The present invention relates to a recording method for printing by attaching an ink composition and a reaction liquid to a recording medium, and the recording medium is composed of a substance that does not absorb even if the recording medium is composed of a substance that absorbs the ink composition. The present invention relates to a recording method for printing an image free from color bleeding or color bleeding using the same ink composition set without subjecting the recording medium to a special surface treatment.

  The water-based ink composition generally contains water as a main component and contains a coloring component and additives such as a wetting agent such as a glycerin, a penetrating agent, a surfactant, and a fungicide / antifungal agent. The recording medium used for the water-based ink composition is generally a recording medium that can absorb the ink composition to some extent and allow the coloring material to penetrate, such as paper or cloth.

  On the other hand, when printing or painting on recording media that do not basically absorb water-based ink compositions such as synthetic resins and metals, solvent-based ink compositions using organic solvents (particularly oleophilic) are generally used. Paint has been used.

  The reason for this is that solvent-based inks and paint compositions are composed of raw materials that do not dissolve in water, so images printed using these inks have fixing, rubbing, and water resistance. In addition, since the time from drying to fixing on a recording medium is short, the productivity is also excellent.

  However, organic solvents are often toxic to animals and plants and have a large environmental load. Therefore, it is necessary to pay attention to its use, disposal, etc., and there are many inconveniences in handling, and in addition, when it is used in large quantities, it is necessary to install an exhaust treatment facility.

  Therefore, even when printing or coating is performed on a non-absorbable recording medium, the recording method using the water-based ink composition is considered preferable from the viewpoints of safety, environment, and convenience of use.

  However, when printing is performed using a water-based ink on a non-absorbent recording medium, the affinity of the ink with respect to the recording medium, so-called “wetting”, becomes a big problem. If the ink wettability with respect to the recording medium is low, the ink will not spread and become water droplets (occurs of repellency), so printing cannot be performed. Are mixed with each other (occurrence of color bleeding), and ink spreads around the printing range (occurrence of bleeding), which causes a problem in image formation.

  In printing on a recording medium, it is also required that the color material component of the water-based ink composition is firmly fixed on the recording medium.

  Also, when printing is performed on a recording medium that absorbs ink, a certain degree of fixability, abrasion resistance, and durability are required. In particular, in order to obtain high-quality images using water-based ink, there should be no color bleeding or color bleeding at the time of printing, and printing can be performed on general paper-like recording media such as plain paper. In this case, it is necessary to prevent the occurrence of a phenomenon (feathering) in which the ink extends like wrinkles only along the paper fibers. Furthermore, depending on the storage environment, water resistance may be required.

  The factors that have been described so far for image degradation are described as follows.

(1) Phenomenon in which ink spreads around (color blur)
(2) Phenomenon in which ink stretches like a ridge only along paper fibers (feathering)
(3) Phenomenon where colors are mixed together and color boundaries become unclear (color bleed)
In order to prevent the occurrence of these image degradation factors, solvent-based ink compositions and paints are generally used for non-absorbent recording media, and the above-mentioned image degradation factors also occur for absorbent recording media. In many cases, printing is performed using a solvent-based ink composition or paint.

  In addition, when printing using water-based ink for applications that require fixing, rubbing resistance, and water resistance, it is common to perform a special surface treatment on the recording medium in advance or a surface treatment after printing. It has been broken. That is, in the former, an ink receiving layer is formed on the printing surface of the recording medium, and in the latter, a protective layer, such as hot and cold laminating, an overcoat layer, and the like are well known as known means.

  However, these special surface treatments and printing surface protection treatments have the drawbacks of complicating the printing apparatus and printing process, increasing costs, and reducing productivity.

  When the present inventors performed printing on an absorbent recording medium by an inkjet recording method using two liquids composed of the ink composition and the reaction liquid, a good image free from color bleeding and color bleeding was obtained. It was. In addition, it was found that even when printing was performed using the same ink on a non-absorbing recording medium, a good image free from color bleeding, feathering, and color bleeding could be obtained.

  It was also found that these images had excellent properties of fixing property, abrasion resistance and water resistance despite being formed using water-based ink.

  Accordingly, it is an object of the present invention to provide a recording method capable of printing a good image free from color bleeding and color bleed using the same ink composition for both absorbent and non-absorbent recording media. Yes.

  The recording method according to the present invention produces an agglomerate when contacted with a water-based ink composition comprising a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water on a recording medium. A recording method for printing by attaching a reactive agent and a reaction liquid containing a cationic resin emulsion, the step of attaching the reaction liquid onto a recording medium, and attaching the ink composition onto the recording medium And recording the image.

  As described above, the recording medium is composed of a pigment, an anionic resin emulsion, a water-soluble organic solvent, and water, regardless of whether the recording medium is a material that absorbs the ink composition or the reaction liquid, or a material that does not substantially absorb the ink. Printing on a recording medium using an ink composition set that combines a water-based ink composition, a reaction agent that forms an aggregate when contacted with the water-based ink composition, and a reaction liquid comprising a cationic resin emulsion. According to the recording method to be performed, it is possible to print an image without color blur or color bleeding on these recording media.

(Recording method)
The recording method according to the present invention comprises a step of attaching a reaction liquid described later on a recording medium and a step of recording an image by attaching an ink composition described later.

  In the recording method according to the present invention, the color material is firmly fixed on the recording medium by adhering the ink composition and the reaction liquid to the recording medium in the printing process, and there is no color bleeding or color bleeding. It is feasible to obtain image quality. The reason for this effect is not clear, but can be inferred as described below.

  First, when the ink composition and the reaction liquid come into contact with each other on the recording medium, the reactant and the cationic resin emulsion in the reaction liquid destroy the dispersion condition of the coloring material and the anionic resin emulsion in the ink composition. It is thought to agglomerate it. It is considered that the color material is fixed when these aggregates adhere to the surface of the recording medium.

  Further, in the present invention, the ink composition contains an anionic resin emulsion, and the reaction solution contains a cationic resin emulsion. The presence of these resin emulsions promotes the formation of the aggregates and their fixation and fixing. It is expected that

  Next, the reaction liquid and the ink composition are brought into contact with each other, and on the printing surface of the image formed on the absorbent recording medium, at the beginning of the contact, an aggregation composed of a coloring material and a resin emulsion in the vicinity of the surface of the recording medium, The aggregate is separated water or a water-soluble organic solvent. Water or a water-soluble organic solvent that is unnecessary for fixing the aggregates penetrates or evaporates into the recording medium and is removed from the surface, so that the aggregates are fixed only on the recording medium, and the resin emulsion aggregates. Is promoted. A resin film is formed by uniting these resin emulsions. In this resin film, the surface functional group of the anionic resin emulsion and the surface functional group of the cationic resin emulsion are electrostatically bonded, and in addition, the surface functional group is formed with a hydrophilic group present on the surface of the recording medium. It is presumed that the hydrogen bond is more firmly fixed on the surface of the recording medium and the image is fixed on the surface of the recording medium. In addition, since this agglutination reaction is a fast 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 non-absorbing recording medium surface, it is preferable to promote the formation of the resin film by removing the separated water or water-soluble organic solvent by a method such as washing. 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 re-dissolve in water after the agglomerates are dried and has water resistance, it does not cause color bleeding or color bleeding even after the recording medium absorbs water. As the order of attaching the reaction liquid and the ink composition to the recording medium, if there is no problem in the process, a method of attaching the reaction liquid to the recording medium and then attaching the ink composition to the recording medium, and further the reaction liquid and the ink Either method of depositing the composition at the same time can be selected.

  Regarding the attachment of the reaction liquid to the recording medium, either the method in which the reaction liquid is selectively attached only to the place where the ink composition is attached or the method in which the reaction liquid is attached to the entire recording medium. Good. The former is economical because the consumption of the reaction liquid can be suppressed to the necessary minimum, but a certain degree of accuracy is required at the position where both the reaction liquid and the ink composition are attached. On the other hand, the latter is less disadvantageous from the viewpoint of cost because the requirement for accuracy of the attachment position of the reaction liquid and the ink composition is relaxed compared to the former, but a large amount of the reaction liquid is attached to the entire recording medium. Therefore, which method is adopted may be determined in consideration of the combination of the ink composition and the reaction liquid.

  The means for adhering the reaction liquid to the recording medium and the means for adhering the ink composition to the recording medium can be recording methods commonly used in the printing industry and the coating industry. For example, direct injection, spraying, coating, transfer Among them, an on-demand ink jet recording method in which printing is performed by discharging droplets onto a recording medium only when printing is performed is most preferable.

  In the present invention, examples of the recording medium include paper, cloth, non-woven fabric, porous film, polymer absorber, and the like that have water absorbability with respect to the ink composition. Specific examples of the absorbent recording medium to which the ink jet recording method according to the present invention can be applied include paper-based media, natural fibers such as cloth and nonwoven fabric, and / or synthetic fibers, media processed with synthetic resins, inorganic, Examples include media composed of porous films composed of organic materials, media processed with water-absorbing polymers, recording media in which these are laminated, and recording media in which two or more of these media are combined and combined. It is done.

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

(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, specifically a yellow ink composition, a magenta ink composition when performing color printing. It is also possible to use a cyan ink composition, and further, a red, green, blue, orange and violet ink composition used for the purpose of expanding the color reproduction range, and in addition to these, a black ink composition is included. Shall be.

(Resin emulsion)
The ink composition and reaction liquid in the present invention comprise 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, acrylic-styrene resin, butadiene resin, styrene resin, crosslinked acrylic resin, crosslinked styrene resin, Examples thereof include benzoguanamine resin, phenol resin, silicone resin, and epoxy resin. In the present invention, the anionic resin emulsion is used to react the coloring material on the surface of the recording medium by the interaction with the reactants in the reaction solution described later, in particular, polyvalent metal ions or polyallylamine or polyallylamine derivatives and the cationic resin emulsion. It has the effect of promoting adhesion.

  The anionic resin emulsion here has a negative zeta potential in water because it dissociates in the aqueous phase on the polymer particle surface in the dispersed phase and has a negatively charged functional group, carboxyl group, sulfone group, etc. In addition, it refers to a dispersion of polymer fine particles that is maintained in a relatively stable dispersion state without being agglomerated by the electrostatic repulsive force.

  On the other hand, the cationic resin emulsion has functional groups such as quaternary ammonium, pyridinium, and quaternary phosphonium on the surface of the polymer particles, which are dispersed phases, and dissociates in water to show a positive zeta potential. It refers to a dispersion of polymer fine particles that does not agglomerate due to mechanical repulsive force and maintains a relatively stable dispersion state.

  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 actually have a minimum film-forming temperature of 20 ° C. or lower. If the film formation of the resin emulsion can be performed at room temperature or less, the printed recording medium does not particularly require a heating means, and the film formation of the printing surface automatically proceeds at room temperature or less, so that the color material is strong on the recording medium. Since it adheres to, it is preferable.

  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 is transparent when the temperature is raised. The lowest temperature at which a continuous film is formed. In the temperature range below the minimum film-forming temperature, a white powder is formed. Furthermore, according to a preferred embodiment of the present invention, the glass transition point of the resin emulsion is further 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 when the water component is evaporated. The ink composition to which the resin emulsion is added has a property that a resin film is similarly formed when water or an aqueous organic solvent is evaporated. This resin film plays a role of firmly fixing the color material component in the ink composition to the surface of the recording medium. Thus, it is considered that an image excellent in durability and water resistance can be realized.

  The amount of these resin emulsions added is 5% by weight or more, preferably 8% by weight or more, based on the ink composition and the reaction liquid. The resin emulsion is contained in the range of 1 to 20, and more preferably in the range of 2 to 10, by weight ratio to the color material.

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

According to a preferred embodiment of the present invention, the anionic resin emulsion preferably has a carboxyl group on the surface thereof, and further has high reactivity with a divalent metal salt. Specifically, a resin emulsion has a light transmittance of a wavelength of 700 nm when 3 volumes of its 0.1 wt% water-dispersible emulsion and 1 volume of a 1 mol / l divalent metal salt aqueous solution are brought into contact with each other. Has reactivity with a divalent metal salt such that the time for 50% of the initial value is 1 × 10 ⁴ seconds or less (preferably 1 × 10 ³ seconds or less, more preferably 1 × 10 ² seconds or less). Is. An anionic resin emulsion reacts when it comes into contact with a divalent metal ion to form a suspended matter, thereby reducing the transparency of the solution. The amount of the suspended matter produced is measured by the light transmittance. Here, divalent metal ions include Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , and Ba ²⁺ , and anions that form salts with them include Cl ⁻ , NO _{^{3 -, I -, Br -}} , ClO 3 - and CH ₃ COO ^- and the like.
Such high reactivity is considered to be caused by the fact that the anionic resin emulsion has a relatively large number of carboxyl groups on the surface thereof.

An ink composition comprising an anionic resin emulsion having a large amount of carboxyl groups on the surface thereof exhibiting high reactivity as described above has an affinity for a nozzle plate of a water-repellent inkjet recording head. Is low. Accordingly, it is possible to effectively prevent the phenomenon in which the ink composition wets the nozzle plate non-uniformly, causing the ink droplets to bend and cause ejection defects, which has been a problem in the conventional ink compositions containing an anionic resin emulsion. Therefore, it has a great advantage. According to a preferred embodiment of the present invention, the contact angle on the Teflon plate of an aqueous emulsion in which an anionic resin emulsion is dispersed in water at a concentration of 10% by weight is preferably 70 ° or more. Furthermore, the surface tension of the water-dispersible emulsion obtained by dispersing the resin emulsion in water at a concentration of 35% by weight is preferably 40 × 10 ⁻³ N / m (20 ° C.) or more. By using the anionic resin emulsion as described above, it is possible to prevent flying bending in the ink jet recording method and to perform good printing.

  Further, due to the dispersion stability resulting from the high hydrophilicity of the resin emulsion surface, the ink composition also 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 two or more polymerizable double bonds. What has a structure bridge | crosslinked by the crosslinkable monomer which has, and contains 0.2 to 4 weight% of structures derived from a crosslinkable monomer is preferable. By using a crosslinkable polymer obtained by copolymerizing three or more crosslinkable monomers having two or more polymerizable double bonds, more preferably three or more during polymerization, the surface of the nozzle plate is made of an ink composition. Furthermore, it becomes difficult to get wet, flight bending can be further prevented, and discharge 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 including 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 kinds of polymers having different compositions are present in phase separation in particles”. Therefore, the shell portion may not only cover the core portion completely, but may cover a portion of the core portion. Further, a part of the shell polymer may form a domain or the like in the core particle. Furthermore, it may have a multilayer structure of three or more layers including layers having different compositions in the middle between the core portion and the shell portion.

  According to a preferred embodiment of the present invention, the anionic resin emulsion is preferably formed of a resin having a core part having an epoxy group and a shell part having a carboxyl group. The epoxy group and the carboxyl group have a property of reacting with each other, but these two groups exist separately in the core part and the shell part. Due to the decrease in water or water-soluble organic solvent, the resin emulsions are united and deformed by the pressure accompanying film formation. As a result, the epoxy group in the core part and the carboxyl group in the shell part are bonded to form a horizontal structure. As a result, an advantage that a film having higher strength can be formed is obtained. The amount of the unsaturated vinyl monomer having an epoxy group is preferably 1 to 10% by weight. Here, the reaction of a part of epoxy groups and carboxyl groups before film formation is permissible in the present invention as long as the film forming ability is not lost. In the present invention, the self-crosslinking property is a property in which a reactive functional group coexists in such a resin emulsion and a network structure is formed by reacting these groups during film formation without adding a curing agent. 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 containing a polymerization catalyst and an emulsifier.
As unsaturated vinyl monomers, acrylic ester monomers, methacrylic ester monomers, aromatic vinyl monomers, vinyl ester monomers, vinyl cyanide monomers, halogenated monomers commonly used in emulsion polymerization, Examples include olefin monomers and diene monomers. Furthermore, specific examples include 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. Acrylate esters such as octadecyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, glycidyl acrylate, etc .; methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n- Hexyl methacrylate, 2-ethylhexyl Methacrylic acid esters such as methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, pendyl methacrylate, glycidyl methacrylate; and vinyl esters such as vinyl acetate; vinyl such as acrylonitrile and methacrylonitrile Cyanogen compounds; halogenated monomers such as vinylidene chloride and vinyl chloride; aromatic vinyl monomers such as styrene, 2-methylstyrene, vinyltoluene, tert-butylstyrene, chlorostyrene, vinylanisole, vinylnaphthalene; ethylene, propylene Olefins such as isopropylene; dienes such as butadiene and chloroprene; vinyl ether, vinyl ketone, vinyl Vinyl monomers such as pyrrolidone. For monomers having no carboxyl group, the use of unsaturated vinyl monomers having a carboxyl group is essential, but preferred examples thereof include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, maleic acid, Among these, use of methacrylic acid is preferable. Examples of emulsifiers that can be used include anionic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof.

  Further, as described above, in the present invention, it is preferable that the monomer-derived molecule has a structure crosslinked by a crosslinkable monomer having two or more polymerizable double bonds. Examples of the crosslinkable monomer 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'-bis (4-acryloxypropyroxyphenyl) propane, 2,2'-bis Diacrylate compounds such as (4-acryloxydiethoxyphenyl) propane; Triacrylate compounds such as trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate; ditrimethylol Tetraacrylate compounds such as tetraacrylate, tetramethylolmethane tetraacrylate, pentaerythritol tetraacrylate; hexaacrylate compounds such as dipentaerythritol hexaacrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol 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-methacryloxy Dimethacrylate compounds such as diethoxyphenyl) propane; trimethacrylate compounds such as trimethylolpropane trimethacrylate and trimethylolethane trimethacrylate; methylenebisacrylamide and divinylbenzene.

  Furthermore, by adding an acrylamide or a hydroxyl group-containing monomer in addition to the above monomer, the printing stability can be further improved. Examples of acrylamides include acrylamide and N, N′-dimethylacrylamide. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. These may be used alone or in combination. Can do.

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, unsaturated vinyl monomers 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. It is done. In addition, examples of the monomer used for introducing a cationic functional group on the surface include dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, dialkylaminoalkyl acrylamides, dialkylaminoalkyl methacrylamides, and these. Quaternary ammonium salts are mentioned. Examples of emulsifiers that can be used include cationic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof.

  Further, as described above, in the present invention, it is preferable that the monomer-derived molecule has a structure crosslinked by a crosslinkable 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. Can be mentioned.

  Further, the resin emulsion having a core-shell structure is produced by a known method, generally by multistage emulsion polymerization. For example, it can be produced by the method disclosed in JP-A-4-76004. Examples of the unsaturated vinyl monomer used for the polymerization include those described above.

In addition, the introduction of an epoxy group into the core part is a method of copolymerizing glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, etc. with another unsaturated vinyl monomer as an unsaturated vinyl monomer having an epoxy group, or one or more types. In preparing the core particles by polymerizing the unsaturated vinyl monomer, an epoxy compound is added at the same time to form a composite. The former method is preferred from the viewpoint of ease of polymerization and polymerization stability.
In addition, an initiator, a surfactant, a molecular weight adjusting agent, a neutralizing agent and the like used in the emulsion polymerization may be used in accordance with a conventional method.

In the present invention, the anionic resin emulsion may be mixed with other components of the ink composition, but is preferably mixed with the other components of the ink composition after being dispersed in water.
In the present invention, the cationic resin emulsion may also be mixed with other components of the reaction solution, but preferably after being dispersed in water, it is mixed with the other components of the reaction solution. In addition, when these resin emulsions are added to the ink composition and the reaction liquid, it is preferable to use them as the last added component in the ink production 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 penetrability of the ink can be obtained. The surfactant is not particularly limited, and preferred examples include anionic surfactants (for example, sodium dodecyl benzene sulfonate, sodium lauryl sulfate, ammonium salt of polyoxyethylene alkyl ether sulfate), cationic surfactants (for example, , Dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, dihexadecyldimethylammonium bromide, etc.), nonionic (nonionic) surfactants (eg, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan) Fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc.), amphoteric surface activity Agent (e.g., betaine, lauryl sulfobetaine, octyl sulfobetaine, such as 1- (3-sulfopropyl) pyridinium betaine) and the like, may be used alone or as a mixture of more than two. Also, acetylene glycol (Olefin Y and Surfinol 82, 104, 440, 465, and 485 (all manufactured by Air Products and Chemicals Inc.)) can be used.

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

  As the resin emulsion satisfying the above conditions in the present invention, known resin emulsions can be used. For example, JP-B-62-1426, JP-A-3-56573, JP-A-3-796178, JP-A-3-3 Resin emulsions described in JP 160068, JP-A 4-18462 and the like can be used.

(Color material)
The color material contained in the ink composition used in the method according to the present invention may be either a dye or a pigment, but is preferably a pigment in terms of light resistance and water resistance. It is also possible to use a pigment and a dye in combination.

  The pigment is not particularly limited, and any of inorganic pigments and organic pigments can be used. As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used. Organic pigments include azo dyes (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelate, acid dye chelate, etc.), nitro pigments, nitroso pigments, aniline black, and the like.

  In particular, carbon black used as black ink includes No.2300, No.900, MCF 88, No.33, No.40, No.45, No.52, MA7, MA8, MA100, No. .2200B etc. are Colombia's Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700 etc. Monarch1400 etc. are Degussa Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black S150, Color Black S160, Color Black S170, Printex35, Printex U, Printex V, Printex 140U , Special Black6, Special Black5, Special Black4A, Special Black4, etc. can be used. As pigments used in yellow ink, CIPigment Yellow1, CIPlgment Yellow2, CIPigment Yellow3, ClPigment Yellow12, CIPigment Yellow13, CIPigment Yellow14C, CIPigment Yellow16, CIPigment Yellow17, CIPigment Yellow73, CIPigment Yellow74, CIPigment Yellow75, CIPigment Yellow83, CIPigment Yellow93, CIPigment Yellow95, CIPigment Yellow97, CIPigment Yellow98, CIPigment Yellow114, CIPigment Yellow128, CIPigment Yellow129, CIPigment Yellow151, CIPigment Yellow154, etc. are mentioned. In addition, as pigments used in magenta ink, CIPigment Red5, CIPigment Red7, CIPigment Red12, CIPigment Red48 (Ca), CIPigment Re 4 (Mn), CIPigment Red57 (Ca), CIPigment Red57: 1, CIPigment Red112, CIPigment Red123, CIPigment Red168, CIPigment Red184, CIPigment Red202 and the like. As pigments used in cyan ink, CIPigment Blue1, CIPigment Blue2, CIPigment Blue3, CIPigment Blue15: 3, CIPigment Blue15: 34, CIPigment Blue16, CIPigment Blue22, CIPigment Blue60, CIVat Blue4, CIVat Blue60 is an example.

  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 the dispersant used for preparing the pigment dispersion, a dispersant generally used for preparing the 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 the pigment dispersion will also function as a surfactant for the ink composition.
Preferable examples of the polymer dispersant include natural polymers. Specific examples thereof include proteins such as glue, gelatin, casein, and albumin; natural rubbers such as gum arabic and tragacanth; glucosides such as saponin; Examples include alginic acid and alginic acid propylene glycol ester, alginic acid triethanolamine, alginic acid derivatives such as ammonium alginate; and cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and ethylhydroxycellulose. Furthermore, preferred examples of the polymer dispersant include synthetic polymers such as polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic. 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 -Styrene-acrylic resin such as -α-methylsterene-acrylic acid copolymer, sterene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer; styrene-maleic acid copolymer, styrene-maleic anhydride copolymer , Vinyl naphthalene-acrylic acid copolymer , Vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, acetic acid Examples thereof include vinyl acetate copolymers such as vinyl-acrylic acid copolymers and salts thereof. Among these, a copolymer of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and a polymer comprising a monomer having both a hydrophobic group and a hydrophilic group in the molecular structure are particularly preferable.

The color material content in the ink composition is preferably about 0.5 to 25% by weight, more preferably about 2 to 15% by weight.
(Water, water-soluble organic solvents, surfactants, and other ingredients)
The solvent of the ink composition used in the method according to the present invention uses 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 comprises a wetting agent composed of a high boiling point organic solvent. Preferred examples of the high boiling point organic solvent agent 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 polyhydric alcohols; 2-pyrrolidone, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.

  Among these, use of a water-soluble organic solvent having a boiling point of 180 ° C. or higher is preferable. 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 of the coloring material or increase in viscosity, and excellent storage stability can be realized. Furthermore, it is possible to realize an ink composition that maintains fluidity and redispersibility for a long time even when left in an open state (a state where it is exposed to air at room temperature).

  Further, in the ink jet recording method, high ejection stability can be obtained without causing nozzle clogging during printing or during restart after printing interruption.

  Examples of water-soluble organic solvents having a boiling point of 180 ° C. or higher include ethylene glycol (boiling point: 197 ° C .; the parentheses indicate boiling points below), 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) It is done. Those having a boiling point of 200 ° C. or higher are preferred. These water-soluble organic solvents can be used alone or in admixture of two or more.

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

  Further, 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 the recording medium (so-called “wetting property”). I can do it. The ink composition used in the method according to the present invention can further contain a surfactant. As an example 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), cationic surfactants (for example, dodecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride) , Dihexadecyldimethylammonium bromide), nonionic (nonionic) surfactants (for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, poly Oxyethylene alkylamine, polyoxyethylene alkylamide, etc.), amphoteric surfactants (eg betaine, lauryl sulfobeta) Emissions, octyl sulfobetaine, 1- (3-sulfopropyl) such as pyridinium betaine) and the like, may be used alone or as a mixture of more than two. Also, acetylene glycol (Olefin Y and Surfinol 82, 104, 440, 465, and 485 (all manufactured by Air Products and Chemicals Inc.)) can be used. By combining these appropriately, the wettability of the ink composition can be controlled, but two types of surfactants having different polar functional groups, that is, an anionic surfactant and a cationic interface, are used. It is not preferable to add an active agent, 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, increasing the viscosity of the ink composition and destroying the dispersed state of the pigment particles. It is because. In addition, it is not preferable to add a surfactant having a polarity opposite to the charge in the dispersed state of the pigment particles, which neutralizes the zeta potential of the pigment particles that are in the dispersed state due to electrostatic repulsion. This is because it loses repulsive force and agglomerates. Therefore, it is not preferable to add a cationic surfactant into a pigment ink containing pigment particles dispersed by negative charging, and similarly an anionic surfactant is added to a positively charged pigment dispersed ink. Is also not preferred.

  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 provides wettability. Further, the addition of a tertiary amine and an alkali metal hydroxide brings about stabilization of dispersion of the coloring material 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, aldonic acid, glucitol. Sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature, such as alginic acid, α-cyclodextrin, and cellulose. In addition, the derivatives of these saccharides include reducing sugars of the saccharides described above (for example, sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). , Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thio sugars, etc. Particularly preferred are sugar alcohols, and specific examples include maltitol, sorbitol, etc. 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 preferably about 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.

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

  Preferable examples of the alginic acid derivative include alginic acid alkali metal salts (for example, sodium salts and potassium salts), alginic acid organic salts (for example, triethanolamine salts), and alginic acid ammonium salts. The amount of the alginic acid derivative added to the ink composition is preferably about 0.01 to 1% by weight, more preferably about 0.05 to 0.5% by weight.

  The reason why a good image can be obtained by the addition of an 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, changes the dispersion state of the color material, and changes the color. This is considered due to the fact that the fixing of the material to the recording medium is promoted.

  In addition, it is possible to add pH adjusters, preservatives, fungicides and the like to the ink composition as necessary in order to improve storage stability.

(Reaction solution)
The reaction liquid used in the present invention comprises a reactive agent and a cationic resin emulsion. Here, the “reactive agent” destroys the dispersion state of the pigment and / or anionic resin emulsion in the ink composition, It can be agglomerated. Examples thereof include polyvalent metal salts, polyamines, and polyamine derivatives.
Cationic resin emulsions also have the property of reacting with and coagulating with anionic resin emulsions due to electrostatic interactions.

The polyvalent metal salt that can be used in the reaction solution is composed of divalent or higher polyvalent metal ions and anions that bind to these polyvalent metal ions, and is soluble in water. Specific examples of polyvalent metal ions include divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , Ba ²⁺ , Al ³⁺ , Fe ³⁺ , Cr ^{3 And} trivalent metal ions such as ⁺ . Examples of the anion include Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ and CH ₃ COO ⁻ .

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 as long as the printing quality and the effect of preventing clogging are obtained, but is preferably about 0.1 to 40% by weight, more preferably 5 to 25% by weight. %.

  According to a preferred aspect of the present invention, the polyvalent metal salt contained in the reaction solution is composed of divalent or higher polyvalent metal ions and nitrate ions or carboxylate ions that bind to these polyvalent metal ions. It is soluble in water. Particularly preferred are nitrate ions.

  Polyallylamine and polyallylamine derivatives that can be used in the reaction solution are cationic polymers that are soluble in water and positively charged in water.

  In addition to the above, a polymer in which allylamine and diallylamine are copolymerized 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 addition amount is 1 or more, preferably 1.0 to 5.0 by weight with respect to the polyvalent metal salt. . Furthermore, according to a preferred embodiment of the present invention, the amount of the polyol added to the reaction solution is preferably 10% by weight or more, more preferably about 10 to 30% by weight.

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

  According to a preferred embodiment of the present invention, the reaction solution comprises a wetting agent composed of a high boiling point organic solvent. The high boiling point organic solvent prevents the reaction solution from drying. Preferable 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-hexanetriol, thioglycol, although they partially overlap with the polyol. , Hexylene glycol, glycerin, trimethylol ethane, trimethylol propane and other polyhydric alcohols; 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 Alkyl ethers of polyhydric alcohols, such as recall monobutyl ether, 2-pyrrolidone, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like. According to a preferred aspect of the present invention, the reaction solution preferably comprises a combination of triethylene glycol monobutyl ether and glycerin.

  The addition 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 with respect to the reaction solution.

  According to a preferred embodiment of the present invention, the reaction solution may contain a low boiling point organic solvent. Preferable 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. A monohydric alcohol is particularly preferable. The low boiling point organic solvent has an effect of shortening the drying time of the ink. The amount of the low-boiling organic solvent added 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 surface active effect. These compounds include anionic surfactants, cationic surfactants, amphoteric surfactants, various surfactants such as nonionic surfactants, alcohols such as methanol, ethanol and iso-propyl alcohol, ethylene glycol Examples include 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, and the like. Thus, it is possible to improve the permeability and affinity (“wetting”) of the reaction liquid with respect to the recording medium.

  Specific examples of the above compounds include Orphin Y, Surfinol 82, Surfinol 440, Surfinol 465, Surfinol 485 (all manufactured by Air Products and Chemicals Inc.) and the like. These may be added alone or in combination of two or more.

  According to a preferred embodiment of the present invention, the reaction solution contains triethanolamine for pH adjustment. When triethanolamine is added, the addition amount is preferably about 0 to 2.0% by weight.

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

  In the following, embodiments of the present invention will be described. However, these examples are intended to 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 To a flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, add 100 ml of distilled water and 0.1 g of potassium persulfate. Heated to ° 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, this emulsion was filtered with a 0.4 μm filter, and prepared with distilled water so that the concentration of the resin emulsion was 30%. The obtained emulsion had a minimum film-forming temperature of about 20 ° C., and exhibited the property of agglomeration when mixed with the reaction solution described later.

Preparation of Cationic Resin Emulsion Dispersion Add 100 ml of distilled water and 0.1 g of potassium persulfate to a flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel. Heated to ° 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 mixed to prepare a mixture. This was gradually dropped into the flask in 3 hours using a dropping funnel. The obtained emulsion was cooled to room temperature and neutralized with potassium hydroxide, and then this emulsion was filtered with a 0.4 μm filter and prepared with distilled water so that the concentration of the resin emulsion was 30%. .

Preparation of ink composition An ink composition having the following composition was prepared. The preparation was performed as follows. The pigment, dispersant, and water were mixed and dispersed in a sand mill (manufactured by Yasukawa Seisakusho) with glass beads (diameter 1.7 mm, 1.5 times the weight (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 dispersant was mixed to form an ink solvent, and the ink solvent was gradually dropped while stirring the pigment dispersion, followed by stirring at room temperature for 20 minutes. Thereafter, the anionic resin emulsion dispersion was gradually added dropwise, stirred and mixed at room temperature for 10 minutes, and then filtered through a 5 μm membrane filter to obtain an ink composition for ink jet recording.

Black pigment ink composition Carbon Black MA-7 (coloring material, manufactured by Mitsubishi Chemical Corporation) 5% (hereinafter abbreviated as wt)%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 10wt%
Glycerin 10wt%
Surfinol 465
(Surfactant, 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 (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 10wt%
Diethylene glycol 10wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Remaining amount of ion-exchanged water Magenta pigment ink
CI Pigment Red 122 (coloring material) 3wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 20wt%
Glycerin 5wt%
Diethylene glycol 5wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Ion exchange water remaining amount Yellow pigment ink
CI Pigment Yellow 74 (coloring material) 3.5wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 15wt%
Glicelli 8wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Remaining ion-exchanged water Preparation of reaction solution A reaction solution was prepared according to the following composition. The preparation was performed as follows. Magnesium nitrate was dissolved in ion-exchanged water, and glycerin and triethylene glycol monobutyl ether were sequentially added thereto while stirring and mixing using a magnetic stirrer.
Next, the cationic resin emulsion dispersion was gradually added dropwise and stirred and mixed at room temperature for 10 minutes, and then filtered through a 5 μm membrane filter to obtain a reaction solution.

Reaction solution magnesium nitrate hexahydrate 25wt%
Cationic resin emulsion (as solid content concentration) 10wt%
Triethylene glycol monobutyl ether 5wt%
Glycerin 10wt%
Ion-exchanged water remaining amount recording medium 1: Plain paper
Xerox P (manufactured by Xerox Corporation)
Recording medium 2: Plain paper
Xerox 4024 (Xerox Co., Ltd.)
Recording medium 3: PET film
Xerox Film <No frame> A4 (Fuji Xerox Co., Ltd.)
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 FPG110 (Oji Oil Chemical Co., Ltd.)
(Example 2)
Black pigment ink composition Carbon Black MA-7 (coloring material, manufactured by Mitsubishi Chemical Corporation) 5% (hereinafter abbreviated as wt)%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 15wt%
Glycerin 10wt%
Surfynol 465 (surfactant) 1wt%
Lauryl sulfobetaine (amphoteric surfactant) 0.5wt%
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 concentration) 15wt%
Diethylene glycol 10wt%
Surfynol 465 (surfactant) 1wt%
Remaining amount of ion-exchanged water Magenta pigment ink
CI Pigment Red 122 (coloring material) 3wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 15wt%
Glycerin 5wt%
Diethylene glycol 5wt%
Surfynol 465 (surfactant) 1wt%
Ion exchange water remaining amount Yellow pigment ink
CI Pigment Yellow 74 (coloring material) 3.5wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Anionic resin emulsion (as solid content concentration) 15wt%
Glycerin 8wt%
Surfynol 465 (surfactant) 1wt%
Residual amount of ion-exchanged water The ink composition was changed to the above composition, and the other portions 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 Black2 (coloring material, AVECIA) 3.5wt%
Glycerin 10wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Triethylene glycol monobutyl ether 7wt%
Residual amount of ion-exchanged water The above dye was added to the ink solvent and dissolved by stirring at room temperature for 20 minutes. And it filtered with a 5-micrometer membrane filter, and was set as the ink composition for inkjet recording.
Only the black ink composition was changed to the above composition, printing was performed on the recording media 1 to 6 in the same manner as in Example 1 without using the reaction liquid, and the 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% (hereinafter abbreviated as wt)%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Glycerin 10wt%
Surfinol 465
(Surfactant, 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 (dispersant) 1wt%
Diethylene glycol 10wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Remaining amount of ion-exchanged water Magenta pigment ink
CI Pigment Red 122 (coloring material) 3wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Glycerin 5wt%
Diethylene glycol 5wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Ion exchange water remaining amount Yellow pigment ink
CI Pigment Yellow 74 (coloring material) 3.5wt%
Styrene-acrylic acid copolymer (dispersant) 1wt%
Glycerin 8wt%
Surfinol 465
(Surfactant, Air Product and Chemicals, Inc.) 1wt%
Residual amount of ion-exchanged water The composition of the ink set was changed to the above, printing was performed on the recording media 1 to 3 in the same manner as in Example 1 without using the reaction solution, and the same evaluation was performed.

(Comparative Example 3)
Except not using a reaction liquid, it printed on the recording media 1-3 by the method similar to Example 1, and implemented the same evaluation.

(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, and the same evaluation was performed. .
(Evaluation test)
Examples were given by combinations as described in Table 1 below. The printed matter subjected to the following evaluation uses an ink jet printer EM-900C manufactured by Seiko Epson Corporation, and prints the ink composition and reaction liquid of the above example on a recording medium at room temperature and normal pressure. I was able to get it. Printing was performed by simultaneously discharging the reaction liquid, black ink, and color ink onto the recording medium. Thereafter, the recording medium was naturally dried and then subjected to the following evaluation.
<Evaluation item 1: Evaluation of color blur after printing>
About the printed matter, the bleeding immediately after printing was visually evaluated according to the following criteria.
A: A good image without blur was obtained.
B: Slight bleeding occurred.
C: Bearded blur occurred.
D: Bleeding occurred so that the color boundary was not clear.
<Evaluation item 2: Evaluation of color bleed after printing>
The printed material was visually evaluated for uneven color mixing at the color boundary according to the following criteria.
A: A good image without color mixing was obtained.
B: Color mixing slightly occurred.
C: Generation of color mixing was observed.
D: Color mixing occurred so that the color boundary was not clear.
<Evaluation item 3: Feathering evaluation after printing>
The printed matter was visually evaluated for the presence or absence of mustache-like bleeding according to the following criteria.
A: A good image with no bearded bleeding was obtained.
B: Slight whisker-like bleeding occurred.
C: Beard-like oozing occurred.
−: Evaluation was not possible due to bleeding and color bleeding.
<Evaluation item 4: Overall evaluation>
The prints were naturally dry. The recording media 3 to 6 were evaluated by visual observation after sufficiently washed with ion-exchanged water and sufficiently dried naturally.
The results were as shown in Table 1 below.

Claims (13)

  An aqueous ink composition composed of at least a coloring material, an anionic resin emulsion, a water-soluble organic solvent, and water; and a reactive agent and a cationic resin emulsion that form an aggregate when contacted with the aqueous ink composition. A recording method using an ink set in combination with a reaction liquid.   The recording method according to claim 1, wherein the color material of the ink composition is a pigment.   The recording method according to claim 1, wherein the addition amount of the anionic resin emulsion used in the ink composition is 1 to 30% by weight with respect to the ink composition.   The recording method according to claim 1, wherein the ink composition contains an anionic surfactant or an amphoteric surfactant.   The recording according to any one of claims 1 to 4, wherein the ink composition contains a surfactant, and an anionic surfactant or an amphoteric surfactant and a nonionic surfactant are used in combination. Method.   The recording method according to claim 1, wherein the reactant is a polyvalent metal salt, polyallylamine, or a polyallylamine derivative.   The recording method according to claim 1, wherein the addition amount of the cationic resin emulsion used in the reaction solution is 1 to 30% by weight with respect to the reaction solution.   The recording medium used for the recording method is a medium that absorbs a water-based ink composition such as paper, cloth, nonwoven fabric, porous film, and polymer absorber and a reaction liquid. The recording method described in 1.   The recording method according to claim 1, wherein the recording medium is a medium that does not substantially absorb a water-based ink composition such as metal, ceramics, rubber, and synthetic resin and a reaction liquid.   8. The recording medium according to claim 1, wherein the recording medium has a laminated structure composed of a single component such as paper, cloth, non-woven fabric, porous film, polymer absorber, metal, ceramics, rubber, and synthetic resin. The recording method according to one item.   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. The recording method according to any one of the above.   The recording method according to claim 1, wherein the step of attaching a droplet of an ink composition on the recording medium is performed simultaneously with the step of attaching the reaction liquid to the recording medium.   The step of adhering droplets of the ink composition on the recording medium or the step of adhering the reaction liquid to the recording medium is an inkjet recording method in which printing is performed by ejecting droplets and adhering to the recording medium. The recording method according to claim 1.