JP2014097632A - Treatment liquid for treating recording medium and image formation device and image formation method using the treatment liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the storage stability, image density, and transfer density of an image formed atop a recording medium by using an aqueous recording ink.SOLUTION: The provided treatment liquid for treating a recording medium includes at least a water-soluble organic solvent, an amphiphilic substance, an organic acid or organic acid salt and/or cation polymer, a hydrophobic crosslinking agent, and water. An aqueous recording ink is recording onto a recording medium preliminarily coated with this treatment liquid. Bisethoxy diglycol succinate, lysine sodium dilauroyl glutamate, specified polymers, etc. can be cited as the amphiphilic substance.

Description

  The present invention relates to a processing liquid for processing a recording medium, an image forming apparatus using the processing liquid, and an image forming method.

  Conventionally, when recording on a recording medium using an aqueous recording ink, the surface of the recording medium is treated with a specific processing liquid and then recorded with an aqueous recording ink in order to improve the scratch resistance of the image. Has been done.

  In Patent Document 1, by forming a cross-linked product of an organic acid and an oxazoline polymer in a treatment liquid, the scratch resistance of an aqueous recording ink ejected later is improved. However, since the organic acid and the oxazoline polymer form a crosslinked structure in the treatment liquid, there is a problem in storage stability. The document also describes that the organic acid and the oxazoline polymer are divided into respective liquids, but dividing into two liquids causes problems in handling.

  In Patent Document 2, the treatment liquid contains a polyvalent metal salt or a resin emulsion. However, for a low-absorbency recording medium such as coated paper, a colorant aggregated with the polyvalent metal salt is used. Is difficult to fix on the recording medium.

  As described above, when water-based recording ink is used, it is very difficult to obtain scratch resistance especially for a non-ink-absorbing or low-absorbing recording medium. Thus, it is conceivable to use a crosslinking agent or a resin emulsion, but storage stability and ejection stability are inferior, and it is difficult to achieve both scratch resistance and storage stability.

  An object of the present invention is to provide a treatment liquid that achieves both scratch resistance and storage stability even for a non-ink-absorbing or low-absorbing recording medium.

  The above object is to process a recording medium characterized in that it contains "at least a water-soluble organic solvent, an amphiphilic substance, an organic acid or an organic acid salt or / and a cationic polymer, a hydrophobic crosslinking agent and water. Can be solved.

  By using the treatment liquid of the present invention, the storage stability, image density, and transfer density of an image formed with a water-based recording ink on a recording medium can be improved.

It is a schematic diagram (side explanatory drawing) showing an example of the liquid discharge apparatus which concerns on this invention. It is a schematic block explanatory drawing of the control part in FIG. FIG. 6 is a schematic diagram illustrating an example of a head arrangement in the head unit of the liquid ejection apparatus according to the present invention. It is a schematic diagram which shows the head currently arranged in the head unit of FIG. FIG. 3 is a diagram illustrating an example of an ink cartridge used in the liquid ejection apparatus according to the present invention. FIG. 6 is a diagram including a case (exterior) of the ink cartridge of FIG. 5. It is a schematic diagram showing an example of a discharge method from a discharge head in the liquid discharge apparatus according to the present invention. It is a schematic diagram which shows an example of the application | coating system by 3 rolls. It is a schematic diagram which shows an example of the application | coating system by 2 rolls.

  In a liquid ejecting apparatus that is generally used, an aqueous recording ink is mainly used. When the water-based recording ink is printed on a recording medium, the colorant solids remain on the surface of the recording medium as a result of water as a main component penetrating into the recording medium and evaporating into the atmosphere. However, when a non-ink-absorbing or low-absorbing recording medium is used, water penetration into the recording medium does not occur sufficiently, and as a result, water containing a colorant component remains on the surface of the recording medium, resulting in scratch resistance. Will be inferior.

  In the present invention, by using an amphiphilic substance in a processing liquid for processing a recording medium (hereinafter also simply referred to as “processing liquid”), a hydrophilic part and a hydrophobic part are present in the processing liquid. The hydrophilic part in the processing liquid contains a carboxyl group-containing resin in the aqueous recording ink and an organic acid or organic acid salt or / and a cationic polymer that reacts with the cross-linking agent in the processing liquid, and the hydrophobic part has hydrophobic cross-linking. When the agent or the treatment liquid contains a hydrophobic substance, it contains a hydrophobic substance that forms a film when the hydrophilic portion disappears. As long as the treatment liquid is divided into a hydrophilic part and a hydrophobic part, the organic acid or the organic acid salt and the cross-linking agent do not react in the treatment liquid even in the state of one liquid, and the hydrophilic part does not disappear. Since the hydrophobic substance can be kept in the system in a stable state, there is no problem in terms of storage stability.

  As a mechanism for improving the scratch resistance in the present invention, first, when the processing liquid is discharged or applied onto the recording medium, the water in the hydrophilic portion in the processing liquid penetrates into the recording medium and evaporates into the atmosphere. As a result, the amount thereof is reduced, and accordingly, the crosslinking agent in the hydrophobic portion causes a crosslinking reaction with the organic acid or organic acid salt in the hydrophilic portion, thereby forming a crosslinked structure on the recording medium. Thereafter, the aqueous recording ink is discharged onto the crosslinked structure, and the colorant of the aqueous recording ink dispersed or microencapsulated with the carboxyl group-containing resin enters the crosslinked structure, and the organic acid or organic acid remaining in the crosslinking reaction Causes agglomeration reaction with salt or / and cationic polymer. Finally, in this series of flows, the hydrophobic substance present in the hydrophobic portion of the treatment liquid is solidified together with the crosslinked structure incorporating the aggregated colorant, and is fixed on the recording medium.

<Water-based recording ink>
In the water-based recording ink of the present invention, at least a colorant is dispersed in a carboxyl group-containing resin or is microencapsulated with a carboxyl group-containing resin, and a water-soluble organic solvent, a fluorosurfactant, an inhibitor is used. Contains foam and water.

(Coloring agent)
As the colorant, a known dye or pigment can be used in the aqueous recording ink. Colorant particles obtained by coating inorganic particles with an organic pigment or carbon black may also be used.
Examples of the method for coating the inorganic particles with carbon black include a submerged drying method by coagulation and precipitation, and a dry mixing method in which a mechanical force is applied while mixing. Examples of the method of coating the inorganic particles with the organic pigment include a method of depositing the organic pigment in the presence of the inorganic particles and a method of mechanically kneading the inorganic particles and the organic pigment. In this case, for example, when coating with an organic pigment having excellent thermal stability, a chemical vapor deposition technique can be used. Furthermore, if an organosilane compound layer produced from polysiloxane and alkylsilane is provided between the inorganic particles and the organic pigment as required, the adhesion between them can be improved.

Examples of the inorganic particles include titanium dioxide, silica, alumina, iron oxide, iron hydroxide, and tin oxide. The inorganic particles preferably have a small aspect ratio, and are particularly preferably spherical. Further, when the color coloring agent is adsorbed on the surface of the inorganic particles, the inorganic particles are preferably colorless and transparent or white. However, when the black coloring agent is adsorbed, black inorganic particles may be used. Absent.
The primary particle size of the inorganic particles is preferably 100 nm, and more preferably 5 to 50 nm.

  An example of the organic pigment that covers the inorganic particles is aniline black as a black pigment. Examples of the color pigment include anthraquinone, phthalocyanine blue, phthalocyanine green, diazo, monoazo, pyranthrone, perylene, heterocyclic yellow, quinacridone, and (thio) indigoid. Among these, phthalocyanine pigments, quinacridone pigments, monoazo yellow pigments, diazo yellow pigments, and heterocyclic yellow pigments are particularly preferable from the viewpoint of color developability.

  Examples of the phthalocyanine pigment include copper phthalocyanine blue or a derivative thereof (CI pigment blue 15: 3, CI pigment blue 15: 4), aluminum phthalocyanine, and the like.

  Examples of quinacridone pigments include C.I. Pigment Orange 48, C.I. Pigment Orange 49, C.I. Pigment Red 122, C.I. Pigment Red 192, C.I. Pigment Red 202, C.I. Pigment Red 206, C.I. Pigment Red 207, C.I. Pigment Red 209, C.I. Pigment Violet 19, C.I. I pigment violet 42 etc. are mentioned.

  Examples of monoazo yellow pigments include C.I. Pigment Yellow 74, C.I. Pigment Yellow 109, C.I. Pigment Yellow 128, C.I. I pigment yellow 151 etc. are mentioned.

Examples of the diazo yellow pigment include C.I. Pigment yellow 14, C.I. Pigment Yellow 16, C.I. I pigment yellow 17 etc. are mentioned.
Examples of the heterocyclic yellow pigment include C.I. Pigment Yellow 117, C.I. I pigment yellow 138 etc. are mentioned.

  The weight ratio (inorganic particles: colorant) between the inorganic particles and the organic pigment or carbon black as the colorant is preferably 3: 1 to 1: 3, and more preferably 3: 2 to 1: 2. If the ratio of the colorant is too small, the color developability and coloring power may be lowered, and if the ratio of the colorant is too large, the transparency and color tone may be deteriorated.

Examples of commercially available colorant particles obtained by coating inorganic particles with an organic pigment or carbon black include silica / carbon black composite materials manufactured by Toda Kogyo Co., Ltd., silica / phthalocyanine C.I. Pigment Blue 15: 3 composite material, silica / diazo yellow composite material, silica / quinacridone C.I. I Pigment Red 122 composite material, etc., which have a small primary particle size and can be suitably used.
For example, when inorganic particles having a primary particle size of 20 nm are coated with an equal amount of organic pigment, the primary particle size is about 25 nm. Therefore, if it can be dispersed in the form of primary particles using an appropriate dispersant, a very fine pigment-dispersed ink having a dispersed particle diameter of 25 nm can be produced.

The primary particle diameter of the colorant particles is preferably 5 to 100 nm, more preferably 30 to 80 nm in the aqueous recording ink. When the primary particle size is less than 5 nm, the ink may thicken or the colorant particles may be aggregated during long-term storage of the ink. When the primary particle size exceeds 100 nm, the aqueous recording ink may be printed on a recording medium. The printed matter may have reduced saturation and lightness. The primary particle size of the colorant particles means the smallest unit of colorant particles that cannot be pulverized further by mechanical shearing.
The content of the colorant particles in the aqueous recording ink is preferably 1 to 20% by weight, and more preferably 2 to 15% by weight.

(Water-soluble organic solvent)
The water-based recording ink according to the present invention uses water as a solvent, but further uses a water-soluble organic solvent for the purpose of preventing the ink from drying and improving the dispersion stability. A mixture of a plurality of these water-soluble organic solvents may be used.

  Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, and ethylene carbonate. Etc.

  Examples of the polyhydric alcohols include glycerin, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, Ethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, hexylene glycol, trimethylolethane, trimethylolpropane, glycerol, 1,2,3-butanetriol, 1,2 , 4-butanetriol, 1,2,6-hexanetriol, petriol and the like.

Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. .
Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  Examples of the nitrogen-containing heterocyclic compounds include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone, and the like. Can be mentioned.

  Examples of amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine and the like.

Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.
Among these water-soluble organic solvents, glycerin, diethylene glycol, 1,3-butanediol, and 3-methyl-1,3-butanediol are particularly preferable. These have excellent effects on solubility and prevention of jetting property defects due to water evaporation. In addition, an aqueous recording ink having excellent storage stability and ejection stability can be produced.

  The mixing ratio of the colorant particles and the water-soluble organic solvent has a great influence on the ejection stability of the ink. If the blending amount of the water-soluble organic solvent is small even though the pigment solid content is large, the evaporation of water near the nozzle advances, resulting in ejection failure.

  In addition to the water-soluble organic solvent, the water-based recording ink according to the invention can be used in combination with other water-soluble organic solvents such as saccharides and derivatives thereof as necessary.

Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and derivatives thereof. Specific examples include glucose, mannose, fructose, ribose, xylose, trehalose, and manntotriose. Here, the polysaccharide means a saccharide in a broad sense and includes substances widely present in nature such as α-cyclodextrin and cellulose.
Examples of the saccharide derivatives include reducing sugars and oxidized sugars of the saccharides. Among these, sugar alcohols are preferable, and specific examples include maltitol and sorbit.
The saccharide content is preferably from 0.1 to 40% by weight, more preferably from 0.5 to 30% by weight, based on the aqueous recording ink.

(Surfactant)
The surfactant is not particularly limited, and can be appropriately selected from surfactants that do not impair dispersion stability, depending on the purpose, depending on the type of colorant, water-soluble organic solvent, penetrant, and the like. . In particular, when printing on a recording medium, a fluorine-based surfactant or a silicone-based surfactant having a low surface tension and high leveling properties is preferable, and a fluorine-based surfactant is particularly preferable.

  Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate ester compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. The polyoxyalkylene ether polymer compound is particularly preferred because of its low foamability.

Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like.
Examples of the perfluoroalkyl carboxylic acid compound include perfluoroalkyl carboxylic acid and perfluoroalkyl carboxylate.
Examples of the perfluoroalkyl phosphate compound include perfluoroalkyl phosphate esters, perfluoroalkyl phosphate salts, and the like.

Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain. Examples thereof include salts of oxyalkylene ether polymers.
As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.

  As said fluorosurfactant, what was synthesize | combined suitably may be used or a commercial item may be used. Examples of the commercially available products include Surflon series (S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145) manufactured by Asahi Glass Co., Ltd. Full Lard Series (FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431) manufactured by 3M, MegaFac Series manufactured by Dainippon Ink (F-470, F-1405, F-474), Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, manufactured by Dupont, FT-110 manufactured by Neos FT-250, FT-252, FT-400S, FT-150, FT-400SW, OM-nova PF-151N, etc., among others. Fluorine-based surfactant having a structure represented by the formula below (4) is particularly preferred.

  There is no restriction | limiting in particular as said silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant.

  As a silicone type surfactant, what was synthesize | combined suitably may be used, or a commercial item may be used. Commercially available products such as Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone are readily available.

In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
As a polyether modified silicone compound, what was synthesize | combined suitably may be used, or a commercial item may be used. As a commercial item, Shin-Etsu Chemical Co., Ltd. KF-618, KF-642, KF-643 etc. are mentioned, for example.

In addition to the fluorine-based surfactant and the silicone-based surfactant, anionic surfactants, nonionic surfactants, amphoteric surfactants, and the like can be used.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, succinate sulfonate, laurate, polyoxyethylene alkyl ether sulfate, and the like.

  Examples of the nonionic surfactant include acetylene glycol surfactants, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, and the like. Examples of the acetylene glycol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, 5-dimethyl-1-hexyn-3-ol and the like. Moreover, as the commercial item, the Surfynol series (104, 82, 465, 485, TG) by Air Products, etc. are mentioned, for example.

  Examples of amphoteric surfactants include lauryl amino pyropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, lauryl dimethyl amine oxide, myristyl dimethyl amine oxide, stearyl dimethyl amine oxide, dihydroethyl lauryl amine oxide, Polyoxyethylene coconut oil alkyldimethylamine oxide, dimethylalkyl (coconut) betaine, dimethyl lauryl betaine and the like can be mentioned. As commercially available products, for example, Nikko Chemicals, Nippon Emulsion, Nippon Shokubai, Toho Chemical, Kao, Adeka, Lion, Aoki Yushi, Sanyo Kasei, etc. can be easily obtained.

  The various surfactants may be used alone or in combination. Even if it is not easily dissolved in the water-based recording ink alone, it may be solubilized by mixing a plurality of inks and can exist stably.

  The content of the surfactant in the aqueous recording ink is preferably 0.01 to 3% by weight, and more preferably 0.5 to 2% by weight. When the total content is less than 0.01% by weight, the effect of adding the surfactant may be lost. When the total content exceeds 3% by weight, the permeability to the recording medium becomes unnecessarily high, and the image density decreases. There may be a show-through.

(Foam suppressant)
However, in particular, the surface active ability of the fluorosurfactant is very high, and even if a commonly used silicone antifoam is added, the generated bubbles remain without disappearing. As a result, there is a possibility that ejection failure or the like may occur when ink is ejected. Therefore, in the present invention, N-octyl-2-pyrrolidone, 2,4,7,9-tetramethyldecane-4,7-diol, 2,5,8,11-tetramethyldodecane are used to suppress the generation of bubbles. Any one of -5,8-diol is added. By using any one of the above-mentioned foam suppressors and the above-mentioned fluorosurfactant in combination, it is possible to suppress the generation of bubbles, and to solve the problems caused by bubbles.

  The surface tension of the water-based recording ink in the present invention is determined by the ratio of the fluorosurfactant and the foam suppressor. However, when the surface tension of the water-based recording ink needs to be lowered depending on the type of the recording medium, the fluorosurfactant is used. It is necessary to increase the ratio of the agent. However, since naturally there is a problem of foaming when the ratio of the fluorosurfactant is increased, the ratio of the fluorosurfactant is 40% by weight with respect to the total amount of the fluorosurfactant and the foam inhibitor. % Or less is preferable, and 30% by weight or less is more preferable.

(Carboxyl group-containing resin)
The aqueous recording ink used in the present invention contains a carboxyl group-containing resin. As a result, the organic acid or organic acid salt in the treatment liquid and the carboxyl group-containing resin in the aqueous recording ink react to cause aggregation of the colorant on the recording medium, so that high image quality can be achieved. Even in the absence of the treatment liquid, an effect such as improvement of scratch resistance can be expected by containing the carboxyl group-containing resin.

  Examples of the carboxyl group-containing resin include maleic acid resin, styrene-maleic acid resin, rosin-modified maleic acid resin, alkyd resin, and modified alkyd resin. Examples of the commercially available products include the Marquide series manufactured by Arakawa Chemical Co., Ltd., the Harimac series manufactured by Harima Kasei Co., Ltd., and the Hariftal series.

  The addition amount of the carboxyl group-containing resin is preferably 1 to 10% by weight in the aqueous recording ink, and more preferably 2 to 5% by weight. The addition form of the carboxyl group-containing resin may be added in a form in which the pigment as the colorant is included (microencapsulated) with the carboxyl group-containing resin, or may be a form in which the colorant is dispersed in the carboxyl group-containing resin. .

(Other ingredients)
In addition to the above-mentioned components, known penetrants, polymer particles, pH adjusters, antiseptic and rust preventives, antifungal agents and the like can be added to the water-based recording ink according to the present invention as necessary. .
As the penetrant, a polyol compound or glycol ether compound having 8 to 11 carbon atoms is preferably used. These are partially water-soluble compounds having the effect of increasing the penetration rate into the recording medium and preventing bleeding and having a solubility of 0.1 to 4.5% by weight in water at 25 ° C.

Examples of the polyol compound having 8 to 11 carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and 1,2-octanediol. .
Examples of the glycol ether compound include polyhydric alcohol alkyl ether compounds and polyhydric alcohol aryl ether compounds.

Examples of the polyhydric alcohol alkyl ether compound include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. .
Examples of the polyhydric alcohol aryl ether compound include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
These penetrants are components that have a higher boiling point than water and are liquid in ink at 25 ° C., and the content in the aqueous recording ink is preferably 0 to 10% by weight, and 0.5 to 5% by weight. Is more preferable.

  As the polymer particles, those having a film-forming property are used. Here, the film-forming property means the property that when polymer particles are dispersed in water to form an emulsion, a resin film is formed when water in the aqueous emulsion is evaporated.

  When such polymer particles are contained, the polymer particles form a film when the volatile components in the aqueous recording ink are evaporated, and the colorant in the ink is firmly fixed to the recording medium. . As a result, an image excellent in scratch resistance and water resistance can be realized.

In order to form a film at room temperature, the polymer particles preferably have a minimum film-forming temperature of 30 ° C. or lower, more preferably 10 ° C. or lower. Here, the minimum film-forming temperature means that a polymer emulsion obtained by dispersing polymer particles in water is thinly cast on a metal plate such as aluminum, and when the temperature is raised, it is transparent and continuous. It means the lowest temperature at which a film is formed. Examples of such polymer particles include Randy PL series manufactured by Miyoshi Oil & Fat Co., Ltd.
The volume average particle diameter of the polymer particles is preferably 5 to 200 nm, more preferably 10 to 100 nm.

  A polymer particle having a single particle structure can be used. For example, when an alkoxysilyl group is contained in the emulsion particles, it comes into contact with water remaining due to fusion of the emulsions due to water evaporation during the coating film formation process, and hydrolyzes to form silanol groups. Moreover, when a silanol group remains, an alkoxysilyl group or silanols react with each other to form a strong crosslinked structure by a siloxane bond. When reactive functional groups coexist in the polymer fine particles as described above, a network structure can be formed by reacting these functional groups during film formation without adding a curing agent.

  It is also possible to use polymer particles having a core-shell structure comprising a core part and a shell part surrounding the core part. The core-shell structure here means a form in which two or more kinds of polymers having different compositions are present in phase separation in the particles. Therefore, not only the form in which the shell part completely covers the core part, but also a part of the core part may be covered. Further, a part of the polymer of the shell part may form a domain or the like in the core particle. Further, it may have a multilayer structure of three or more layers including one or more layers having different compositions between the core portion and the shell portion.

  The polymer particles can be obtained by a known method such as emulsion polymerization of an unsaturated vinyl monomer (unsaturated vinyl polymer) in water containing a polymerization catalyst and an emulsifier. The content of the polymer particles in the aqueous recording ink is preferably 0.5 to 20% by weight, and more preferably 1 to 5% by weight. When the content is less than 0.5% by weight, the scratch resistance and water resistance improvement functions may not be sufficiently exhibited. A malfunction will occur.

The above-mentioned colorant particles (composite pigment particles) obtained by coating inorganic particles with an organic pigment or carbon black have a strong tendency to show acidity when kneaded and dispersed in water together with an anionic dispersant. The surface of the composite pigment dispersed in a medium such as water is negatively charged because it is wrapped in an anionic dispersant, but the inside of the ink is positively charged because the entire ink is acidic. Thus, the negative charge on the particle surface is easily neutralized. In this state, the dispersed particles agglomerate and cause a discharge failure. Therefore, it is preferable to stabilize the dispersion state by adding a pH adjuster to keep the dispersion and to stabilize the discharge.
The pH of the aqueous recording ink is preferably 9-11. When the pH exceeds 11, the amount of the material for the ink supply unit or the like that melts increases, and problems such as ink deterioration, leakage, and ejection failure occur.

  The pH adjuster is preferably added when the pigment is kneaded and dispersed in water together with the dispersant, and is preferably added together with additives such as a kneading dispersant, a wetting agent, and a penetrating agent. This is because the dispersion may be destroyed by addition depending on the pH adjusting agent.

Examples of the pH adjuster include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates.
Examples of alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.
Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

<Processing liquid>
The treatment liquid applied to the recording medium before discharging the aqueous recording ink does not contain at least a colorant, and is a water-soluble organic solvent, amphiphilic substance, organic acid or organic acid salt or / and cationic polymer, hydrophobic Contains a crosslinking agent and water.

(Water-soluble organic solvent)
Water or a water-soluble organic solvent can be added to the treatment liquid as a solvent. Examples of the water-soluble organic solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, and ethylene carbonate. Etc.

  Examples of the polyhydric alcohols include glycerin, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, Ethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, hexylene glycol, trimethylolethane, trimethylolpropane, glycerol, 1,2,3-butanetriol, 1,2 , 4-butanetriol, 1,2,6-hexanetriol, petriol and the like.

Examples of the polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. .
Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

Examples of amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.

  Among these water-soluble organic solvents, glycerin, diethylene glycol, 1,3-butanediol, and 3-methyl-1,3-butanediol are particularly preferable. These have excellent effects on solubility and prevention of jetting property defects due to water evaporation. In addition, a treatment liquid having excellent storage stability and discharge stability can be produced.

(Amphiphile)
As the amphiphilic substance in the present invention, there are those having a hydrophobic group and a hydrophilic group in the structure, and a core-shell structure having a hydrophobic group in the core part and a hydrophilic group in the shell part when water is used as a medium. preferable. In the present invention, the hydrophilic part in the treatment solution contains an organic acid or organic acid salt, and the hydrophobic part contains a crosslinking agent that causes a crosslinking reaction with the organic acid or organic acid salt. In order to avoid this, a shell having a long hydrophilic group chain length is preferred. These amphiphiles include bisethoxydiglycol succinate, lysine sodium dilauroylglutamate, a polymer represented by the following general formula (1), and a dendritic polymer represented by the following general formula (2). Including at least one selected from the group consisting of

（ここでＲ１、Ｒ２、及びＲ３はそれぞれ水素原子、炭素数１〜６のアルキル基またはヒドロキシアルキル基から選択される。Ｒは炭素数４〜８のアルキル基を示す。Ｘ及びＹは１以上２０以下の整数を示す）

(Here, R1, R2 and R3 are each selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group. R represents an alkyl group having 4 to 8 carbon atoms. X and Y are one or more. Represents an integer of 20 or less)

（式中、Ｘは、−Ｙ−Ｚ基を樹状ポリマーの別の部分に連結させる二価有機連結基を含み、Ｙは以下の構造：
−Ｗ−Ｃ（Ｒ３）＝Ｃ（Ｒ４）−Ｃ（Ｒ５Ｒ６）−Ｃ（Ｒ７）＝Ｃ（Ｒ８）−、
−Ｗ−Ｃ（Ｒ３）＝Ｃ（Ｒ４）−Ｃ（Ｒ７）＝Ｃ（Ｒ８）−、
または上記式の混合物
（式中、Ｗは、存在する場合、二価有機基であり、Ｒ基はそれぞれ独立して水素原子、置換もしくは非置換アルキル基、置換もしくは非置換シクロアルキル基、置換もしくは非置換アリール基、または置換もしくは非置換アルケニル基の１つを示し、Ｚは水素または一価有機基を表す）の１つを含む）により表される少なくとも１つの構造単位を含む。市販品としては、パーストープ社製のボルトーンシリーズ、ＤＳＭ社製のハイブレーンシリーズ、デンドリティック・ナノテクノロジーズ社製のプリオスターシリーズやスターバーストシリーズなどが挙げられる。

Wherein X comprises a divalent organic linking group that links the —Y—Z group to another portion of the dendritic polymer, and Y is the following structure:
-W-C (R3) = C (R4) -C (R5R6) -C (R7) = C (R8)-,
-W-C (R3) = C (R4) -C (R7) = C (R8)-,
Or a mixture of the above formulas wherein W is a divalent organic group, if present, and each R group is independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or 1 represents an unsubstituted aryl group, or one of a substituted or unsubstituted alkenyl group, and Z represents one of hydrogen and a monovalent organic group). Examples of commercially available products include Perstorp Bolton series, DSM High Brain series, Dendritic Nanotechnologies Priostar series and Starburst series.

(Organic acid, organic acid salt)
The organic acid referred to here is preferably one containing a carboxyl group in its structure. Organic acids and organic acid salts are produced in the body or contained in foods and the like, have little remaining in the human body, and many are odorless, and are preferable for use in image forming apparatuses in homes and offices. Specifically, succinic acid, citric acid, malic acid, tartaric acid, lactic acid and the like are preferable, among which lactic acid is particularly preferable, and ammonium lactate and calcium lactate are particularly preferable.

  The role of the organic acid and the organic acid salt in the present invention includes aggregation of the pigment on the recording medium by reaction with the carboxyl group-containing resin in the aqueous recording ink. In the present invention, the addition amount of the organic acid and the organic acid salt is preferably 10% by weight or less, and more preferably 5% by weight or less. When the amount of organic acid and organic acid salt added increases, the agglomeration effect of the pigment due to the reaction with the carboxyl group-containing resin in the aqueous recording ink increases, resulting in a dot diameter on the recording medium. Will become smaller. This indicates that the spread of the dots is reduced. In particular, when the solid portion is insufficiently filled, the influence of the background color of the recording medium appears in the image. Therefore, it is necessary to determine the addition amount of the organic acid and the organic acid salt within a range where there is no problem on the image.

(Cationic polymer)
As the water-soluble cationic polymer used in the treatment liquid, a water-soluble cationic polymer obtained by polymerizing a monomer containing an amine and epihalohydrin is used. The water-soluble cationic polymer obtained by polymerizing these monomers contains hydroxyl groups, ammonium cations, etc. in the main chain, and releases halogen anions in an aqueous solution, thereby aggregating buffering action and pigment when in contact with ink. It is thought to have a function of enhancing the effect of

  Specifically, the water-soluble cationic polymer is preferably a water-soluble cationic polymer selected from a polyamine-epihalohydrin copolymer, a polyamide-epihalohydrin copolymer, a polyamide polyamine-epihalohydrin copolymer, and an amine-epihalohydrin copolymer. Used for. More preferably, as the water-soluble cationic polymer, a copolymer represented by the following general formula (5), a copolymer having a repeating unit represented by the following (6), and an amine represented by the following formula (7): At least one compound selected from a copolymer obtained by polymerizing a monomer (diethylenetriamine), a monomer represented by the following formula (8), and a monomer represented by the following formula (9) is used.

〔Ｒ１〜Ｒ８は、炭素数１〜８のアルキル基、ヒドロキシアルキル基、アルケニル基、ベンジル基のいずれかであり、Ｘはハロゲン原子を示す。ｎは１または２の整数を示す〕

[R1 to R8 are any of an alkyl group having 1 to 8 carbon atoms, a hydroxyalkyl group, an alkenyl group, and a benzyl group, and X represents a halogen atom. n represents an integer of 1 or 2]

〔Ｘはハロゲン原子を示し、ｍは１以上の整数を示す〕

[X represents a halogen atom, and m represents an integer of 1 or more.]

〔Ｘはハロゲン原子を示す〕

[X represents a halogen atom]

  As the amine monomer, triethylenetetraamine, tetraethylenepentamine, iminobispropylamine, and the like can be used in addition to diethylenetriamine represented by the above formula (7), but they are industrially produced and easily available. In view of the above, the monomer represented by the formula (7) is preferable. In addition, you may use quaternary ammonium salt type | mold cationic polymers other than these compounds, and the water-dispersible cationic polymer depending on the case as a water-soluble cationic polymer.

  The water-soluble cationic polymer includes a method of polymerizing a monomer containing an amine and an epihalohydrin, a method of graft polymerizing a monomer containing an epihalohydrin on a polyamide obtained by polymerizing a monomer containing an amine and a carboxylic acid, and the like. It is obtained by a known method. The weight average molecular weight of the water-soluble cationic polymer varies depending on the type of copolymer, and in the case of an amide-epihalohydrin copolymer, it is preferably in the range of 500 to 100,000, and a polyamide-epihalohydrin copolymer or a polyamide polyamine-epihalohydrin copolymer. In the case of, a range of 10,000 to 5 million is preferable, and in the case of an amine-epihalohydrin copolymer, a range of 700 to 50,000 is preferable. When the weight average molecular weight exceeds each of the above upper limits, an aqueous solution may not be formed, and when the lower limit is not satisfied, the treatment liquid effect may be reduced.

  The addition amount of these water-soluble cationic polymers is preferably 1 to 40% by weight, more preferably 3 to 30% by weight, based on the entire liquid composition of the present embodiment. When the addition amount is more than 40% by weight, not only the effect of improving the image quality may not be changed even if the addition amount is increased, but also the viscosity of the liquid composition may be excessively increased. If the addition amount is less than 1% by weight, the effect of improving the image quality may be reduced.

(Hydrophobic substance)
In the present invention, a hydrophobic substance can be contained in the hydrophobic part in the treatment liquid. Specifically, it is selected from any one of alkyd resins, epoxy resins, and waxes.
Alkyd resins containing carboxyl groups are composed of fats and oils, polybasic acids and polyhydric alcohols, but fats and oils include semi-drying oils such as soybean oil and fatty acids such as coconut oil, palm oil, olive oil, castor oil. Alkyd resins made of non-drying oil or semi-drying oil having an iodine value of 80 or less, such as rice bran oil and cottonseed oil, can also be used as long as there is no problem. Examples of the polybasic acid include unsaturated polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, tetrahydrophthalic acid, fumaric acid, itaconic acid, and citraconic anhydride.

  Polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, glycerin, trimethylolpropane, neopentyl glycol, diglycerin, triglycerin, pentaerythritol, diethylene Examples include pentaery slit, mannit, and sorbit. The oil length of the alkyd resin is indicated by the weight% in the resin when the fatty acid in the fat is present as triglyceride.

As the alkyd resin containing a carboxyl group, it is preferable to use one having an iodine value of 80 or more, such as soybean oil-modified alkyd resin, in consideration of the scratch resistance of the aqueous recording ink. Also, oils having an oil length of 60 to 90 and an iodine value of 80 or less can be used as long as there is no hindrance. The oil length of the alkyd resin is preferably from 60 to 90 and an iodine value of around 80, but the weight average molecular weight of the alkyd resin is preferably less than 30,000, and more preferably 10,000 or less. Commercially available products include the Arakawa series manufactured by Arakawa Chemical Co., and the Haliftal series manufactured by Harima Chemicals. Moreover, it is preferable that the addition amount is 1 to 10 weight% in a process liquid, and it is more preferable that it is 2 to 5 weight%.
Examples of the epoxy resin include 1,6-hexanediol diglycidyl ether, polypropylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether, and the like. Commercially available products include the SR series manufactured by Sakamoto Yakuhin Co., and the Epiol series manufactured by NOF Corporation. Moreover, it is preferable that the addition amount is 1 to 10 weight% in a process liquid, and it is more preferable that it is 2 to 5 weight%.

  Examples of the wax include animal and plant waxes such as carbana wax, candelix wax, beeswax, rice wax, lanolin, petroleum waxes such as paraffin wax, microcrystalline wax, polyethylene wax, oxidized polyethylene wax, petrolatum, montan wax, ozokerite. And mineral waxes such as carbon wax, Hoechst wax, polyolefin wax, stearamide, and other natural / synthetic wax emulsions such as α-olefin / maleic anhydride copolymer and blended wax.

  Among these waxes, polyolefin wax, polypropylene wax, and polyethylene wax are particularly preferable. Commercially available products include, for example, Noopcoat series manufactured by San Nopco, Chemipearl series manufactured by Mitsui Chemicals, and AQUACER series manufactured by Big Chemie. The wax content is preferably 0.5% by weight to 6% by weight, more preferably 1% by weight to 3% by weight in terms of solid content.

(Hydrophobic crosslinking agent)
In this invention, a crosslinking agent is contained in the hydrophobic part in a process liquid. The cross-linking agent used in the present invention is preferably one that causes a cross-linking reaction with the organic acid or organic acid salt contained in the hydrophilic portion in the treatment liquid. Specifically, it is selected from any one of carbodiimide and a polymer represented by the following formula (3). In any case, the scratch resistance can be improved by forming a crosslinked structure with the organic acid or organic acid salt in the treatment liquid.

  The commercial products include the Carbodilite series manufactured by Nisshinbo Chemical Co., and the Cheminox series manufactured by Unimatec. The amount of the crosslinking agent added is preferably 10% by weight or less, and more preferably 3% by weight or more and 5% by weight or less.

  In the present invention, the organic acid or organic acid salt and the crosslinking agent are used in combination to form a crosslinked structure by previously reacting the organic acid or organic acid salt with the crosslinking agent on the recording medium. By further discharging, it is possible to further improve the scratch resistance. The desirable role of the organic acid or organic acid salt in this embodiment is that on the recording medium by the crosslinking reaction with the crosslinking agent added in the treatment liquid or the reaction with the carboxyl group-containing resin in the aqueous recording ink. There are two types of pigment aggregation.

  In order to realize these two roles, the addition amount of the crosslinking agent in this embodiment is preferably 0.5 mol or less with respect to 1 mol of the organic acid. This is because when all the organic acids are used in the first crosslinking reaction with the organic acid, the subsequent crosslinking reaction with the carboxyl group-containing resin in the aqueous recording ink does not occur.

(Surfactant)
The surfactant added to the treatment liquid is added to lower the surface tension of the treatment liquid. One of the characteristics required for the treatment liquid of the present invention is that it can be appropriately wetted with various recording media and can be discharged or applied without unevenness. By making it easy to wet moderately, the penetration speed into various recording media can be increased, and problems such as scratch resistance and bleeding can be improved.

  In particular, the penetrability of the treatment liquid into various recording media is very important. If the penetrability is low, a large amount of the processing liquid stays near the surface of the recording medium, and when it comes into contact with the aqueous recording ink containing the colorant on the recording medium, the organic acid in the processing liquid may cause The carboxyl group-containing resin containing the colorant causes an agglomeration action excessively, resulting in insufficient filling of the solid image due to a decrease in the dot diameter. Further, when the colorant component remains excessively on the surface of the recording medium, problems such as scratch resistance also occur.

  For the above reasons, in order to improve wettability, it is common to add a surfactant to lower the surface tension. Specifically, it is particularly preferable to use any one of polyoxyalkylene alkyl ether or a fluorosurfactant having a structure represented by the following formula (4).

  The fluorine-based surfactant having the above structure does not contain PFOS (perfluorooctane sulfonic acid) and PFOA (perfluorooctanoic acid), and is excellent from the viewpoint of global environmental pollution.

  The addition amount of the surfactant in the present invention is preferably 0.5% by weight to 3% by weight, more preferably 1% by weight to 2% by weight in the case of polyoxyalkylene alkyl ether. If it is a fluorine-type surfactant of the said structure, 0.01 weight%-4 weight% are preferable, and 0.1 weight%-1 weight% are more preferable.

(Foam suppressant)
However, the surface active ability of the fluorosurfactant having the above structure is very high, and even if a commonly used silicone antifoam is added, the generated bubbles remain without disappearing. Accordingly, there is a possibility that uneven application occurs when applying with a roller or the like, or defective discharge occurs when discharging with a discharge head. Therefore, in the present invention, N-octyl-2-pyrrolidone, 2,4,7,9-tetramethyldecane-4,7-diol, 2,5,8,11-tetramethyldodecane are used to suppress the generation of bubbles. It is preferable to add any one of -5,8-diol. By using any one of the above-mentioned foam suppressors and the above-mentioned fluorosurfactant in combination, it is possible to suppress the generation of bubbles, and to solve the problems caused by bubbles.

  The surface tension of the treatment liquid in the present invention is determined by the ratio of the fluorosurfactant and the antifoaming agent. If the surface tension of the treatment liquid needs to be lowered depending on the type of the recording medium, the ratio of the fluorosurfactant is set. There is a need to do more. However, since naturally there is a problem of foaming when the ratio of the fluorosurfactant is increased, the ratio of the fluorosurfactant is 40% by weight with respect to the total amount of the fluorosurfactant and the foam inhibitor. % Or less is preferable, and 30% by weight or less is more preferable. In the present invention, the total addition amount of the fluorosurfactant and the foam inhibitor is preferably 2% by weight or less, more preferably 1% by weight or less based on the total amount of the treatment liquid.

(Other ingredients)
In addition to the above-mentioned components, a known penetrant, pH adjustment adjuster, antiseptic / rust preventive, antifungal agent and the like can be added to the treatment liquid in the present invention as necessary.
As the penetrant, a polyol compound or glycol ether compound having 8 to 11 carbon atoms is preferably used. These are partially water-soluble compounds having the effect of increasing the penetration rate into the recording medium and preventing bleeding and having a solubility of 0.1 to 4.5% by weight in water at 25 ° C.

Examples of the polyol compound having 8 to 11 carbon atoms include 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, and 1,2-octanediol. .
Examples of the glycol ether compound include polyhydric alcohol alkyl ether compounds and polyhydric alcohol aryl ether compounds.

Examples of the polyhydric alcohol alkyl ether compound include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. .
Examples of the polyhydric alcohol aryl ether compound include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.

  These penetrants are components that have a higher boiling point than water and are liquid in ink at 25 ° C., and the content in the aqueous recording ink is preferably 0 to 10% by weight, and 0.5 to 5% by weight. Is more preferable.

  Examples of the pH adjuster include alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates.

Examples of alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and the like.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.

Examples of the ammonium hydroxide include ammonium hydroxide, quaternary ammonium hydroxide, quaternary phosphonium hydroxide, and the like.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, and potassium carbonate.

  Examples of antiseptic / antifungal agents include sodium dehydroacetate, sodium sorbate, 2-pyridinethiol-1-oxide sodium, sodium benzoate, sodium pentachlorophenol and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

<Ink cartridge>
Each of the cartridges filled with the treatment liquid or the aqueous recording ink in the present invention is accommodated in a container, and has other members and the like appropriately selected as necessary.
The container is not particularly limited, and its shape, structure, size, material, etc. can be appropriately selected according to the purpose. For example, the container has an ink bag formed of a plastic container, an aluminum laminate film, etc. Is mentioned.
Specific examples include those shown in FIGS. 5 and 6 to be described later. Details of FIGS. 5 and 6 will be described later.

<Liquid ejection device>
The liquid ejection apparatus used in the present invention includes an image forming unit that forms an image by ejecting ink onto the surface of a recording medium, a storage unit that stores a processing liquid, and the image forming unit that performs the image formation before or after the image forming unit. And processing means for processing the surface of the recording medium. The image forming unit includes at least an ink flying unit, and includes other units such as a stimulus generation unit and a control unit as necessary.

FIG. 1 shows a schematic diagram (side explanatory view) of an example of a liquid discharge apparatus.
The liquid ejection apparatus 101 includes head units 110K, 110C, 110M, and 110Y that integrate heads that eject aqueous recording ink, and maintenance units 111K, 111C, and 111M that perform head maintenance corresponding to the head units. 111Y, ink cartridges 107K, 107C, 107M and 107Y for supplying ink, and sub ink tanks 108K, 108C, 108M and 108Y for storing a part of ink from the cartridge and supplying ink to the head with an appropriate pressure. .

Further, a conveyance belt 113 that sucks and conveys the recording medium 114 by the suction fan 120, conveyance rollers 119 and 121 that support the conveyance belt 113, a tension roller 115 that controls the conveyance belt 113 to maintain an appropriate tension, and a conveyance belt 113 are suitable. A platen 124 and a platen roller 118 for maintaining flatness, a charging roller 116 for applying electrostatic charge to attract the recording medium 114, a discharge roller 117 for pressing the recording medium 114, and a discharged recording medium 114 are stocked. A paper discharge tray 104, a paper feed tray 103 for stocking the recording medium 114 to be printed, separation pads 112 and 122 for feeding the recording medium 114 one by one from the paper feed tray, and the recording medium sent Counter roller for securely adsorbing 114 to the charging belt 23, a paper feeding mechanism including a manual feed tray 105 to be used when the paper feed by manual feed.
Further, a waste liquid tank 109 for collecting waste liquid discharged after maintenance and an operation panel 106 capable of operating the apparatus and displaying the apparatus state are also provided.

  The nozzle rows of each head unit are arranged so as to be orthogonal to the conveyance direction of the recording medium 114, and form a nozzle row that is longer than the recording area. The recording medium 114 is separated from the sheet feeding tray into one sheet by a separation roller, and is fixed on the conveyance belt by being in close contact with the conveyance belt by a pressure roller, and liquid is applied to the recording medium when passing under the head unit. By ejecting the droplets, patterning can be performed on the recording medium with the droplets at high speed, separated from the conveying belt by the separation claw, and supported by the ejection rollers and the ejection rollers, the recorded matter is placed on the ejection tray. Discharged.

  This apparatus employs roller coating as a mechanism for treating the surface of a recording medium with a treatment liquid. The processing liquid 135 is supplied from the processing liquid storage tank 140 through a path (not shown), is pumped up to the roller surface by the pumping roller 137, and is transferred to the film pressure control roller 138. Subsequently, the processing liquid transferred to the application roller 136 is transferred and applied to the recording medium 114 passing between the application liquid and the counter roller 139 for application.

  The application amount of the processing liquid transferred to the application roller 136 is performed by controlling the nip thickness with the application roller 136. When it is not desired to apply the treatment liquid, the movable blade 134 can be pressed against the application roller 136 so that the treatment liquid does not remain on the application roller 136, and the treatment liquid on the surface of the application roller can be scraped off. As a result, it is possible to prevent functional troubles such as thickening due to drying caused by the treatment liquid remaining on the application roller 136, adhesion to the application counter roller 139, and application unevenness. Further, as shown in FIG. 1, one sheet feeding unit is provided at the top and bottom, and the lower sheet feeding unit is used when applying the processing liquid, and the upper sheet feeding unit is used when the processing liquid is not applied. It is also possible to adopt a method like

In addition to the roller application, it is also possible to spray the treatment liquid by a discharge method. For example, a treatment liquid can be filled in a head similar to 110K and ejected onto the recording medium 114 in the same manner as ink, and the ejection amount and ejection position can be controlled with high accuracy and ease. Further, a roller coating method and a spray coating method may be used in combination.
Regardless of which method is used, the treatment liquid can be applied in an arbitrary amount at an arbitrary position.

  Further, by heating the recording medium to which the treatment liquid and the ink are attached by the hot air blowing fan 150, the scratch resistance can be improved by promoting drying or promoting crosslinking reaction. In this example, the heating process is performed on the recording medium after printing with a hot air fan. However, the heating process may be performed on the recording medium before printing or before and after printing. It may be performed not only by a means such as a heating roller.

FIG. 3 is a schematic diagram showing an example of a head arrangement in the head unit of the liquid ejection apparatus.
The head unit fixes the heads 154A to 154L to the head outer peripheral member 160, and the heads are fixed in a staggered arrangement so that a part of the nozzles overlap.

  FIG. 4 is a schematic diagram showing the heads arranged in the head unit of FIG. 3. Each head is provided with nozzles 200 that are opened in a zigzag arrangement in two rows in the nozzle plate 201. The head outer peripheral member is sealed with a filler 202 to eliminate a gap from the nozzle surface side.

Next, an overview of the control unit of the liquid ejection apparatus shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a schematic block diagram of the control unit.
This control unit 300 is a CPU 301 that controls the entire apparatus, a program executed by the CPU 301, a nozzle surface contamination degree value and a nozzle surface contamination allowable threshold for predetermined ink ejection used in the present invention, drive waveform data, and other fixed items. ROM 302 for storing data, RAM 303 for temporarily storing image data and the like, non-volatile memory (NVRAM) 304 for holding data even while the apparatus is powered off, various signal processing for image data, It includes an ASIC 305 that processes image processing for switching and other input / output signals for controlling the entire apparatus.

  The control unit 300 also includes a host I / F 306 for transmitting and receiving data and signals to and from the host side, and a head drive control unit 307 that generates a drive waveform for driving and controlling the pressure generating means of the recording head 154. A recording medium conveyance motor drive control unit 308 for driving the recording medium conveyance motor 309, a maintenance unit movement motor drive control unit 312 for driving the head unit (carriage) movement motor 311, and an electromagnetic valve 315 for the ink path. An ink path valve control unit 314 for controlling the opening and closing of the ink, a liquid feeding suction motor drive control unit 316 for controlling the driving of the cap suction motor 317 and the ink supply motor 318, and detection according to the moving amount and moving speed of the conveyor belt 113 An encoder that outputs a signal and a sensor that detects environmental temperature and environmental humidity (whichever is acceptable) Detection signals from 323, the ink amount detection signal of the sub ink tank, and a like I / O322 for inputting detection signals from various sensors (not shown). An operation panel 106 for inputting and displaying information necessary for the apparatus is connected to the control unit 300.

The control unit 300 receives print data or the like from the host side of an information processing device such as a personal computer, an image reading device such as an image scanner, an imaging device such as a digital camera, or the like via a cable or a network by the host I / F 306. .
The CPU 301 reads and analyzes the print data in the reception buffer included in the host I / F 306, performs necessary image processing and data rearrangement in the ASIC 305, and reduces the print head 154 to one page of the head width. Corresponding image data (dot pattern data) is sent to the head drive controller 307 in synchronization with the clock signal.

The CPU 301 then reads and analyzes the print data in the reception buffer included in the host I / F 306, performs necessary image processing, data rearrangement processing, and the like in the ASIC 305, and sends the image data to the head drive control unit 307. Forward. The generation of dot pattern data for image output may be performed, for example, by storing font data in the ROM 302, or the image data is developed into bitmap data by a host-side printer driver and transferred to this apparatus. You may make it do.
The head drive control unit 307 selectively applies to the pressure generating means of the recording head 154 based on image data (dot pattern data) corresponding to one page of the recording head 154 input in page units. Drive.

Although not shown, when the processing liquid is applied by a roller, it is necessary to control the driving of a coating roller group such as a coating roller. Therefore, a coating motor control unit, a motor to be controlled, and a control sensor are provided. Provide.
On the other hand, when the treatment liquid is ejected, there is a risk of nozzle clogging due to color mixture unless the maintenance operation is performed differently from that of other inks. Therefore, the maintenance unit moving motor is preferably provided for processing separately from ink.

  Next, the ink cartridge will be described with reference to FIGS. Here, FIG. 5 is a view showing an example of the ink cartridge of the present invention, and FIG. 6 is a view including a case (exterior) of the ink cartridge of FIG.

  As shown in FIG. 5, the ink is filled into the ink bag 241 from the ink inlet 242 and exhausted, and then the ink inlet 242 is closed by fusion. In use, ink is supplied to the apparatus by inserting a needle of the apparatus main body into the ink discharge port 243 made of a rubber member. The ink bag 241 is formed of a packaging member such as a non-permeable aluminum laminate film. As shown in FIG. 6, the ink bag 241 is usually housed in a cartridge case 244 made of plastic, and is used as an ink cartridge 240 that is detachably attached to a liquid ejection device.

  In addition, if a processing liquid is put in the ink cartridge 240 instead of ink and used as a cartridge for the processing liquid, it can be used by being detachably mounted on various image forming apparatuses like the ink cartridge.

In addition, as a form which apply | coats a process liquid to a recording medium, systems, such as a system of FIGS. 7-9, can be considered.
FIG. 7 describes an ejection method from the ejection head. A recording head for ejecting the treatment liquid 135 is provided on the upstream side in the transport direction of the recording medium 114, and an aqueous recording ink 130 is provided on the downstream side in the transport direction. The treatment liquid 135 ejected in advance based on predetermined image data and the water-based recording ink 130 can be mixed on the recording medium 114.

  FIG. 8 describes the coating method using three rolls, but since details are described in FIG. 1, description thereof is omitted here.

  FIG. 9 describes a coating method using two rolls. The treatment liquid 135 discharged from the discharge head is controlled to a predetermined film thickness by the application roller 401 and the film thickness control roller 402 and applied to the recording medium 114. . Further, the excess processing liquid remaining on the application roller 401 is collected by the movable blade 134. Although not shown here, a water-based recording ink discharge head is provided at the lower part in the transport direction of FIG.

<Processing liquid application means and processing liquid application process>
The treatment liquid application means is not particularly limited as long as it is a means for applying the liquid discharge apparatus treatment liquid onto a recording medium, and can be appropriately selected according to the purpose.
The treatment liquid coating step is not particularly limited as long as a coating method for uniformly coating the liquid ejection apparatus treatment liquid on the recording medium surface is used.

  Examples of such coating methods include blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U comma coating, and AKKU coating. Method, smoothing coating method, micro gravure coating method, reverse roll coating method, 4 to 5 roll coating method, dip coating method, curtain coating method, slide coating method, die coating method and the like.

The treatment liquid coating step is effective when performed on a recording medium whose surface is sufficiently dried or on a recording medium being dried.
In addition, a drying process can be provided as needed with respect to the recording medium which processed.
In this case, the recording medium can be dried by a roll heater, a drum heater or hot air.

Wet adhesion amount to the recording medium of the liquid ejector treatment liquid in the treatment step ^is preferably intended to achieve the range of ^{0.1g / m 2 ~30.0g / m 2} , 0.2~ 10.0 g / m ² is more preferable.
When the adhesion amount is less than 0.1 g / m ² , the image quality (image density, saturation, color bleed, character bleeding, and white spot) may hardly be improved, and 30.0 g / m. ^If it exceeds ² , the texture of plain paper may be impaired or curling may occur.

<Recording medium>
The recording medium is not particularly limited and can be appropriately selected according to the purpose. For example, plain paper, glossy paper, special paper, cloth, film, OHP sheet, general-purpose printing paper, etc. can be suitably used. is there.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated further more concretely, this invention is not limited at all by these Examples.

<Preparation of water-based recording ink>
(Synthesis example)
550 g of methyl ethyl ketone is added to a reaction vessel of an automatic polymerization reaction device (manufactured by Sakai Sangyo Co., Ltd .: polymerization tester DSL-2AS type) having a reaction vessel equipped with a stirring device, a dropping device, a temperature sensor, and a reflux device having a nitrogen introduction device at the top. While charging and stirring, the inside of the reaction vessel was purged with nitrogen. The reaction vessel was heated at 80 ° C. while maintaining a nitrogen atmosphere, and then 75.0 g of methacrylic acid-2-hydroxyethyl, 77.0 g of methacrylic acid, 80.0 g of styrene and 150 butyl methacrylate were added by a dropping device. A mixed solution of 0.0 g, 98.0 g of butyl acrylate, 20.0 g of methyl methacrylate, and 40.0 g of “Perbutyl (registered trademark) O” (manufactured by NOF Corporation) was dropped over 4 hours. After completion of the dropwise addition, the reaction was further continued at the same temperature for 15 hours, and a methyl ethyl ketone solution of an anionic group-containing styrene-acrylic copolymer A having an acid value of 100, a weight average molecular weight of 21,000, and Tg (calculated value) of 31 ° C. Got. After completion of the reaction, a part of methyl ethyl ketone was distilled off under reduced pressure to obtain a copolymer A solution having a nonvolatile content adjusted to 50%.

(Preparation of aqueous pigment dispersion)
In a mixing tank equipped with a cooling jacket, 1000 g of carbon black, 800 g of the copolymer A solution obtained in the synthesis example, 143 g of an aqueous sodium hydroxide solution, 100 g of methyl ethyl ketone, and 1957 g of water were charged and mixed. The mixed solution is passed through a dispersion device (Mitsui Mining Co., Ltd .: SC Mill SC100) filled with zirconia beads having a diameter of 0.3 mm, and dispersed for 6 hours by a circulation method (a method of returning the dispersion station from the dispersion device to the mixing tank). did. The number of revolutions of the dispersing device was 2,700 rpm, and the temperature of the dispersion liquid was kept at 40 ° C. or less through the cooling jacket through cold water. After completion of the dispersion, the dispersion stock solution was taken out from the mixing tank, and then the mixing tank and the dispersion apparatus dew were washed with 10,000 g of water, and the diluted dispersion liquid was obtained together with the dispersion stock solution. The diluted dispersion was put into a glass distillation apparatus, and the whole amount of methyl ethyl ketone and a part of water were distilled off. After cooling to room temperature, 10% hydrochloric acid was added dropwise with stirring to adjust the pH to 4.5, and the solid content was filtered with a Nutsche filter and washed with water. Take the cake into a container, add 200 g of 20% aqueous potassium hydroxide solution, disperse it with Dispa (made by Tokushu Kika Kogyo Co., Ltd .: TK Homo Disper), add water to adjust the non-volatile content, An aqueous pigment dispersion in which 20% carbon black was dispersed in an aqueous medium as composite particles coated with a carboxyl group-containing styrene-acrylic copolymer neutralized in potassium hydroxide was obtained.
Similarly, an aqueous pigment dispersion (cyan) in which carbon black was replaced with copper phthalocyanine (manufactured by Dainichi Seika Co., Ltd .: SEIKALIGHT BLUE A612) was obtained.

(Preparation of water-based recording ink)
First, the resin, water-soluble organic solvent, surfactant, penetrant, pH adjuster, antibacterial agent and water shown in Table 1 were stirred for 1 hour and mixed uniformly. Next, an antifoaming agent was added and the mixture was further stirred for 1 hour and mixed uniformly. Thereafter, the aqueous pigment dispersion obtained in Preparation Example 1 was added, and the mixture was further stirred for 1 hour and mixed uniformly. This mixture was subjected to pressure filtration through a polyvinylidene fluoride membrane filter having an average pore size of 0.8 μm to remove coarse particles and dust to obtain an aqueous recording ink. In the aqueous recording ink, the colorant is added in such a ratio that the solid content of the aqueous pigment dispersion obtained in Preparation Example 1 is 8% by weight.

[Examples 1 to 18, Comparative Examples 1 to 4]
(Synthesis of cationic polymer)
A 1-liter four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube was charged with 657.2 g of water, 58.4 g of triethylenetetramine, and 108 g of 50% dimethylamine, and epithelialized with nitrogen gas introduced. After 192.4 g of chlorohydrin was appropriately reduced over 1.5 hours so as not to exceed 40 ° C., the temperature was raised to 70 ° C. and kept for 1.5 hours. Next, the pH is adjusted to 7.5 with 30% aqueous sodium hydroxide solution, further kept at 70 ° C. for 1.5 hours, adjusted to pH 3.5 with 30% aqueous sulfuric acid solution, and cooled to complete the reaction. It was. The obtained reaction product was a cationic polymer having a solid content concentration of 29.9%, a viscosity of 20 cps (solid content concentration of 10%), and a pH of 3.5.

(Preparation of treatment solution)
Cationic polymer synthesized above, bisethoxydiglycol succinate (manufactured by Higher Alcohol Industry Co., Ltd .: High-Oxstar DCS), dilauroyl glutamic acid sodium lysine (manufactured by Asahi Kasei Chemicals Co., Ltd .: Perisea LB-10), alkyd resin (manufactured by Arakawa Chemical Co., Ltd .: Table 1 shows various components such as Arachid 3145-80), epoxy resin (Sakamoto Yakuhin Kogyo Co., Ltd .: SR-4PG), polyethylene wax (Bic Chemie Co., Ltd .: MINERPOL 221), carbodiimide (Nisshinbo Chemical Co., Ltd .: V-05). The mixture was stirred for 1 hour and mixed uniformly. This mixture was subjected to pressure filtration through a polyvinylidene fluoride membrane filter having an average pore size of 0.8 μm to remove coarse particles and dust, and treatment liquids of Examples 1 to 18 and Comparative Examples 1 to 4 were obtained.

<Evaluation>
(Printing method)
The treatment liquid of each Example and Comparative Example was uniformly applied to a recording medium (My Paper manufactured by Ricoh Company) using a wire bar (winding diameter: 0.05 mm) manufactured by Kobayashi Seisakusho.
Next, an aqueous recording ink was discharged at a printing speed of 30 rpm onto the recording medium with a liquid discharging apparatus (IPSIO GX5000 manufactured by Ricoh Co., Ltd.) to obtain a print sample.

About the said printing sample and the process liquid, various characteristics were evaluated with the following method.
(Image density)
A solid portion of a 3 cm square solid image formed with a dot pattern was measured with a spectrocolorimetric densitometer (939) manufactured by X-Rite.

(Transfer density (fixability))
A solid portion of a 3 cm square solid image formed with a dot pattern is affixed to a clock meter manufactured by Toyo Seiki Seisakusho Co., Ltd. and rubbed, and the transfer density of the ink onto the cloth after rubbing is determined by X-Rite Co. Measured with a spectral color densitometer (939). The smaller the transfer density, the better the image fixability.

(Foam evaluation: foam height after 30 seconds)
10 ml of the aqueous recording ink and the treatment liquid mixed and prepared based on the prescriptions described in the comparative examples or examples are placed in a 100 ml graduated cylinder and allowed to stand overnight, and then the graduated cylinder is placed in a 10 ° C. constant temperature water bath. The liquid temperature was adjusted by adding more than a minute. When the liquid temperature was sufficiently accustomed, air was blown into a predetermined syringe and bubbled up to 100 ml, and the bubble height after 30 seconds was confirmed visually.

(Storage stability evaluation)
The treatment liquid was allowed to stand in a thermostatic bath at 70 ° C. for 2 weeks, and the difference between the initial viscosity and the viscosity after storage (viscosity increase level) was determined in the following three stages.
○: No increase in viscosity is observed Δ: Some increase in viscosity is recognized ×: A remarkable increase in viscosity is observed

1) By containing a water-soluble organic solvent, an amphiphilic substance, an organic acid or an organic acid salt or / and a cationic polymer, or a hydrophobic crosslinking agent from Comparative Examples 1 to 4 and Example 1 It was shown that storage stability, image density and transfer density were excellent.
2) From Comparative Example 3 and Examples 1 to 4, bisethoxydiglycol succinate, dilauroylglutamate sodium lysine as an amphiphilic substance in the treatment solution, amphiphilic substance described in Chemical Formula 1, It was shown that storage stability was excellent by containing any one of the amphiphilic substances.
3) From Comparative Example 1 and Examples 1, 14, 15 and the like, it was shown that the image density was excellent by containing lactic acid or ammonium lactate as the organic acid in the processing solution.
4) From Examples 1, 11, 12, and 13, it was shown that the transfer density was excellent by containing any one of alkyd resin, epoxy resin, and wax as a hydrophobic substance in the treatment liquid.
5) From Comparative Example 4 and Examples 1 and 5, it was shown that the transfer density was excellent when the treatment liquid contained carbodiimide as a hydrophobic crosslinking agent and a water-based crosslinking agent described in Chemical Formula 3.
6) From Examples 1, 6, and 9, it was shown that foaming properties were excellent by containing a polyoxyalkylene alkyl ether or a surfactant described in Chemical formula 4 as a surfactant in the treatment liquid.
7) From Comparative Examples 1, 2, 3, 4 and Examples 1, 7, 8, and 10, N-octyl-2-pyrrolidone, 2,4,7,9-tetramethyldecane as a foam inhibitor in the treatment liquid It was shown that foaming properties were further improved by containing any one of -4,7-diol and 2,5,8,11-tetramethyldodecane-5,8-diol.

101 Liquid Ejector 103 Paper Feed Tray 104 Paper Discharge Tray 105 Manual Tray 106 Operation Panel 107K Ink Cartridge 107C Ink Cartridge 107M Ink Cartridge 107Y Ink Cartridge 108K Sub Ink Tank 108C Sub Ink Tank 108M Sub Ink Tank 108Y Sub Ink Tank 109 Waste Liquid Unit 110K Head unit 110C Head unit 110M Head unit 110Y Head unit 111K Maintenance unit 111C Maintenance unit 111M Maintenance unit 111Y Maintenance unit 112 Separation pad 113 Conveying belt 114 Recording medium 115 Tension roller 116 Charging roller 117 Paper discharge roller 118 Platen roller 119 Conveying roller 120 Suction Fan 121 Transport roller 122 Separation pad 123 Counter roller 124 Platen roller 130 Water-based recording ink 134 Movable blade 135 Processing liquid 136 Application roller 137 Pumping roller 138 Film pressure control roller 139 Application counter roller 140 Processing liquid storage tanks 154A to 155L Head 160 Peripheral member 200 Nozzle 201 Nozzle plate 202 Filler 240 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge case 300 Controller 301 CPU
302 ROM
303 RAM
304 Nonvolatile memory (NVRAM)
305 ASIC
306 Host I / F
307 Head drive control unit 308 Recording medium conveyance motor drive control unit 309 Recording medium conveyance motor 311 Head unit (carriage) movement motor 312 Maintenance unit movement motor drive control unit 314 Ink path valve control unit 315 Electromagnetic valve 316 Liquid feeding suction motor drive control 317 Cap suction motor 318 Ink supply motor 322 I / O
323 Sensor 401 Application roller 402 Film pressure control roller

JP 2010-131777 A JP 2011-105915 A

Claims (9)

  A treatment liquid for treating a recording medium, comprising at least a water-soluble organic solvent, an amphiphilic substance, an organic acid or an organic acid salt or / and a cationic polymer, a hydrophobic crosslinking agent, and water. The amphiphilic substance is composed of bisethoxydiglycol succinate, lysine sodium dilauroylglutamate, a polymer represented by the following general formula (1), and a dendritic polymer represented by the following general formula (2) The processing liquid for processing a recording medium according to claim 1, wherein the processing liquid is at least one selected from the group consisting of:

(Here, R1, R2 and R3 are each selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group. R represents an alkyl group having 4 to 8 carbon atoms. X and Y are one or more. Represents an integer of 20 or less)

Wherein X comprises a divalent organic linking group that links the —Y—Z group to another portion of the dendritic polymer, and Y is the following structure:
-W-C (R4) = C (R5) -C (R6R7) -C (R8) = C (R9)-,
-W-C (R4) = C (R5) -C (R6) = C (R7)-,
Or a mixture of the above formulas wherein W is a divalent organic group, if present, and R4 to R9 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted Or an unsubstituted aryl group, or one of a substituted or unsubstituted alkenyl group, wherein Z represents one of hydrogen or a monovalent organic group) and includes at least one structural unit represented by   The processing liquid for processing a recording medium according to claim 1, wherein the organic acid or organic acid salt is lactic acid or ammonium lactate.   The processing liquid for processing a recording medium according to any one of claims 1 to 3, further comprising a hydrophobic substance, wherein the hydrophobic substance is any one of an alkyd resin, an epoxy resin, and a wax. The processing liquid for processing a recording medium according to claim 1, wherein the hydrophobic crosslinking agent is any one of carbodiimide and a compound represented by the following formula (3).

The recording medium according to claim 1, further comprising a surfactant, wherein the surfactant is polyoxyalkylene alkyl ether or represented by the following formula (4): Processing liquid to be processed.

  Further, it contains an antifoaming agent, and the antifoaming agent is N-octyl-2-pyrrolidone, 2,4,7,9-tetramethyldecane-4,7-diol and 2,5,8,11-tetramethyldodecane- The processing liquid for processing a recording medium according to claim 1, wherein the processing liquid is at least one selected from the group consisting of 5,8-diol.   A treatment liquid application means for applying the treatment liquid for treating the recording medium according to any one of claims 1 to 7 to the recording medium, a colorant, a water-soluble organic solvent, a fluorosurfactant, a foam inhibitor, and A recording ink comprising water and a recording ink in which the colorant is dispersed in a carboxyl group-containing resin or is a colorant microencapsulated with a carboxyl group-containing resin. An image forming apparatus comprising: a recording ink applying unit that is applied to the top.   A treatment liquid application step for applying the treatment liquid for processing the recording medium according to any one of claims 1 to 7 onto the recording medium, a colorant, a water-soluble organic solvent, a fluorosurfactant, and an antifoaming agent. And a recording ink containing water and water, wherein the colorant is dispersed in a carboxyl group-containing resin or a colorant microencapsulated with a carboxyl group-containing resin. An image forming method comprising: a recording ink applying step applied onto a medium.

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