JP3601358B2 - Reaction liquid for ink jet recording and ink jet recording method using the same - Google Patents

Description

【００８２】
評価４：
反応液１および５をそれぞれインクジェットプリンタＭＪ−５００Ｃのヘッドに充填し、全ノズルからの反応液の吐出を確認した後、記録ヘッドにキャップをした状態で、４０℃の環境に１週間放置した。放置後、記録ヘッドをプリンタから取り出し、共析メッキの施されたノズル面を顕微鏡で観察した。その結果、反応液１を充填した記録ヘッドのノズル面には変化が見られなかったが、反応液５を充填した記録ヘッドのノズル面には腐食が観察された。
【図面の簡単な説明】
【図１】本発明によるインクジェット記録方法の実施に好ましく用いられるインクジェット記録装置を示す図であって、この態様においては記録ヘッドとインクタンクがそれぞれ独立してなり、インク組成物および反応液はインクチューブによって記録ヘッドに供給される。
【図２】記録ヘッドのノズル面の拡大図であって、１ｂが反応液のノズル面であり、１ｃがインク組成物のノズル面である。
【図３】図２の記録ヘッドを用いたインクジェット記録方法を説明する図である。図中 で、３１は反応液付着領域であり、３２は反応液が付着された上にインク組成物が印字された印字領域である。
【図４】本発明によるインクジェット記録方法の実施に好ましく用いられる記録ヘッドの別の態様を示す図であって、吐出ノズルが全て横方向に並べて構成されたものである。
【図５】本発明によるインクジェット記録方法の実施に好ましく用いられるインクジェット記録装置を示す図であって、この態様においては記録ヘッドとインクタンクは一体に形成されている。
【符号の説明】
１ 記録ヘッド
２ インクタンク
３ インクチューブ
２１ 反応液吐出ノズル
２２、２３、２４、２５ インク組成物吐出ノズル
３１ 反応液付着領域
３２ 印字領域[0001]
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION The present invention relates to an ink jet recording method, and more particularly, to an ink jet recording method for performing printing by adhering two liquids of a reaction liquid and an ink composition to a recording medium.
[0002]
Background art
The ink jet recording method is a printing method in which droplets of an ink composition are made to fly and adhere to a recording medium such as paper to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive device. Generally, an ink composition used for ink jet recording mainly contains water, and further contains a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging.
[0003]
On the other hand, as an ink jet recording method, a method has recently been proposed in which a polyvalent metal salt solution is applied to a recording medium, and then an ink composition containing a dye having at least one carboxyl group is applied (for example, a special method). JP-A-5-202328). According to this method, an insoluble complex is formed from a polyvalent metal ion and a dye, and the presence of the complex is capable of obtaining a high-quality image having water resistance and no color bleed.
[0004]
Further, by using a color ink containing at least a surfactant or a penetrating solvent that imparts permeability and a salt, and a black ink that thickens or aggregates by the action of the salt, image density is increased. It has also been proposed to obtain a high-quality color image without color bleed (Japanese Patent Laid-Open No. 6-106735). Further, Japanese Patent No. 2675001 also proposes a recording method in which a reaction liquid containing a polyvalent metal salt and a dye ink containing an anionic group are attached, that is, a first liquid containing a salt is mixed with an ink composition. An ink jet recording method has been proposed in which a good image can be obtained by printing two liquids.
[0005]
Furthermore, there has been proposed an ink jet recording method in which a reaction liquid containing a polyvalent metal salt and an ink composition containing a resin emulsion are attached to a recording medium to perform printing (Japanese Patent Application Laid-Open No. 9-207424).
[0006]
Summary of the Invention
The present inventor has now found that in such an ink jet recording method for printing two liquids, a good reaction can be achieved by using a reaction solution containing at least a polyvalent metal salt, ammonia, and benzotriazole or a benzotriazole derivative. It has been found that a printing solution can be realized, and a reaction solution having excellent storage stability and ejection stability can be obtained. Furthermore, it has been found that stable printing can be performed for a long period of time without damaging the nozzle plate by combining with an ink jet recording head having a nozzle plate that has been subjected to eutectoid plating. The present invention is based on such findings.
[0007]
Accordingly, an object of the present invention is to provide a reaction liquid which can be used in an ink jet recording method for printing two liquids, can achieve good print quality, and has excellent storage stability and ejection stability.
[0008]
Another object of the present invention is to provide an ink jet recording method for printing two liquids using the reaction liquid according to the present invention.
[0009]
Then, the reaction liquid according to the present invention ejects droplets of the ink composition and droplets of the reaction liquid that cause agglomerates when they come into contact with the ink composition, and adheres the droplets to a recording medium for printing. Is a reaction liquid used in an ink jet recording method for carrying out the method, which comprises at least a polyvalent metal salt, ammonia, and benzotriazole or a benzotriazole derivative.
[0010]
Further, the ink jet recording method according to the present invention discharges a droplet of the ink composition and a droplet of a reaction liquid that causes an aggregate when contacted with the ink composition, and adheres the droplet to a recording medium to perform printing. Wherein the reaction liquid is the reaction liquid according to the present invention.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Ink jet recording method The ink jet recording method according to the present invention comprises a step of printing a reaction liquid and an ink composition on a recording medium.
[0012]
In the ink jet recording method according to the present invention, good printing can be realized by contact between the reaction liquid and the ink composition. The following is a hypothesis, and the reason is as follows, provided that the present invention is not interpreted in a limited manner. When the reaction liquid and the ink composition come into contact with each other, it is considered that the polyvalent metal salt in the reaction liquid destroys the dispersion state of the colorant and other components in the ink composition, and causes the aggregation. It is considered that these aggregates suppress the permeation of the colorant into the recording medium. As a result, it is considered that an image having high color density, bleeding, and less printing unevenness is realized. Further, in a color image, there is an advantage that uneven color mixing in a boundary region of different colors, that is, color bleed can be effectively prevented. The above mechanism is only an assumption, and the present invention is not construed as being limited to this mechanism.
[0013]
Further, in the present invention, a reaction solution containing ammonia and benzotriazole or a benzotriazole derivative together with a polyvalent metal salt is used. This reaction solution has excellent discharge stability and storage stability. Further, as described above, the polyvalent metal salt is considered to destroy the dispersion state of the colorant and other components in the ink composition and to aggregate the same. When printing was performed over a period, the occurrence of printing defects was observed. It is considered that the cause is that the nozzle plate subjected to the water-repellent treatment by the eutectoid plating is eroded by the polyvalent metal salt. Ammonia and benzotriazole or a benzotriazole derivative are thought to effectively suppress this erosion, and it is thought that this makes it possible to discharge the reaction solution stably over a long period of time. However, the above is only an assumption, and the present invention is not construed as being limited to this mechanism.
[0014]
The order in which the reaction liquid and the ink composition are applied to the recording medium may be any order, that is, a method in which the reaction liquid is attached to the recording medium, and then the ink composition is attached to the recording medium, And a method of adhering the reaction liquid after printing the ink, and a method of mixing the reaction liquid and the ink composition immediately before or immediately after the ejection.
[0015]
Regarding the adhesion of the reaction liquid to the recording medium, either a method in which the reaction liquid is selectively applied only to the place where the ink composition is to be applied or a method in which the reaction liquid is applied to the entire surface of the paper may be used. . The former is economical because it can minimize the consumption of the reaction liquid, but requires a certain degree of accuracy in the position where both the reaction liquid and the ink composition are adhered. On the other hand, in the latter, the requirement for the accuracy of the adhesion position of the reaction liquid and the ink composition is relaxed as compared with the former, but a large amount of the reaction liquid adheres to the entire paper surface, and the paper is easily curled during drying. Therefore, which method is adopted may be determined in consideration of the combination of the ink composition and the reaction liquid. When the former method is adopted, the reaction liquid can be attached by an ink jet recording method.
[0016]
Reaction solution The reaction solution used in the present invention contains at least a polyvalent metal salt, ammonia, and benzotriazole or a benzotriazole derivative.
[0017]
As described above, the polyvalent metal salt is considered to have a function of destroying the dispersed state of the colorant and other components in the ink composition and aggregating the same. According to a preferred embodiment of the present invention, the polyvalent metal salt is composed of a divalent or higher polyvalent metal ion and an anion bonded to the polyvalent metal ion, and is preferably a water-soluble salt. . Specific examples of polyvalent metal ^{ions, Ca 2+, Cu 2+, Ni} 2+, Mg 2+, Zn 2+, divalent metal ion ^Al 3+, such as ^{Ba 2+,} Fe ^3+, trivalent metal ions such as ^{Cr 3+} and the like . Examples of the anion include Cl ⁻ , NO ₃ ⁻ , I ⁻ , Br ⁻ , ClO ₃ ⁻ and CH ₃ COO ⁻ .
[0018]
In particular, a metal salt composed of Ca ²⁺ or Mg ²⁺ gives a favorable result from the two viewpoints of the pH of the reaction solution and the quality of the obtained printed matter.
[0019]
The concentration of these polyvalent metal salts in the reaction solution may be appropriately determined within a range in which the effect of preventing printing quality and clogging can be obtained, but is preferably about 0.1 to 40% by weight, more preferably about 5 to 40% by weight. It is about 25% by weight.
[0020]
According to a more preferred embodiment of the present invention, the polyvalent metal salt is composed of a divalent or higher polyvalent metal ion, and a nitrate ion or a carboxylate ion bonded to the polyvalent metal ion, and is soluble in water. It is preferred that it is.
[0021]
Here, the carboxylate ion is preferably derived from a saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms or a carbocyclic monocarboxylic acid having 7 to 11 carbon atoms. Preferred examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid and the like. Particularly, formic acid and acetic acid are preferred.
[0022]
A hydrogen atom on the saturated aliphatic hydrocarbon group of the monocarboxylic acid may be substituted with a hydroxyl group, and a preferred example of such a carboxylic acid is lactic acid.
[0023]
Further, preferred examples of the carbocyclic monocarboxylic acid having 6 to 10 carbon atoms include benzoic acid and naphthoic acid, and more preferably benzoic acid.
[0024]
The reaction solution according to the present invention further comprises ammonia. The amount of ammonia added may be appropriately determined in consideration of good printing quality, printing stability, and storage stability and in consideration of pH, but is preferably about 0.5% by weight or less, more preferably. Is 0.3% by weight or less.
[0025]
Further, the reaction solution according to the present invention comprises benzotriazole or a benzotriazole derivative. A benzotriazole derivative is a compound having a benzotriazole structure in its structure, for example, a compound having a substituent C _1-6 alkyl group (preferably a methyl group and an ethyl group), a hydroxyl group, a carboxyl group, a phenyl group and the like, and salts thereof. Means Specific examples of the benzotriazole derivative include 1,2,3-benzotriazole sodium salt, 1,2,3-benzotriazole potassium salt, tolyltriazole, tolyltriazole potassium salt, tolyltriazoleamine, and 2- (2′-hydroxy -5-methylphenyl) benzotriazole and the like.
[0026]
According to a preferred embodiment of the present invention, the benzotriazole derivative is preferably soluble in at least 0.03 g with respect to 100 g of water.
[0027]
The amount of benzotriazole or benzotriazole derivative added may be appropriately determined within a range where the effect can be obtained. However, according to a preferred embodiment of the present invention, the amount is preferably 0.03% by weight or more, more preferably 0.05% by weight or more. It is.
[0028]
According to a preferred embodiment of the present invention, the pH of the reaction solution is preferably 8 or more, and more preferably 8 or more and 10 or less.
[0029]
According to a preferred embodiment of the present invention, the reaction solution can comprise a polyol. Here, the polyol has a vapor pressure at 20 ° C. of 0.01 mmHg or less, and the amount of the polyol added to the reaction solution is preferably 10% by weight or more, more preferably 10 to 30% by weight. It is about. Preferred specific examples of the polyol include polyhydric alcohols such as glycerin, diethylene glycol, triethylene glycol, 1,5-pentanediol, and 1,4-butanediol. Further, preferred specific examples of the polyol include sugars such as monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, and preferably glucose, mannose, fructose, ribose, xylose, arabinose, and the like. Examples include galactose, aldonic acid, glucosyl, sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. These polyols may be added alone or as a mixture of two or more.
[0030]
According to a preferred embodiment of the present invention, the reaction solution may comprise a wetting agent comprising a high-boiling organic solvent. The high boiling organic solvent prevents head clogging by preventing the reaction solution from drying.
[0031]
Preferred examples of the high boiling point organic solvent partially overlap with the polyol, but include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, and thioglycol. And polyhydric alcohols such as hexylene glycol, glycerin, 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 Alkyl ethers of polyhydric alcohols such as glycol monobutyl ether, urea, 2-pyrrolidone, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-like imidazolidinone.
[0032]
The amount of the high-boiling organic solvent is not particularly limited, but is preferably about 0.5 to 40% by weight, more preferably about 2 to 20% by weight.
[0033]
Further, the reaction solution in the present invention may contain a nonvolatile organic amine for pH adjustment. Examples of the non-volatile amines include monoethanolamine, monoisopropanolamine, ethyl monoethanolamine, dimethanolamine, dimethylethanolamine, diethylethanolamine, triethanolamine, morpholine and the like. The amount of the non-volatile amine to be added is appropriately determined in consideration of the pH of the reaction solution, but is preferably about 0.1 to 2.0% by weight.
[0034]
Ink composition The ink composition used in the present invention comprises a colorant, an organic solvent, water, and preferably additives such as a resin emulsion.
[0035]
The colorant contained in the ink composition is preferably one that reacts with the polyvalent metal salt in the above-described reaction liquid to form an aggregate. The colorant may be either a dye or a pigment, but is preferably a pigment.
[0036]
As the dye, various dyes usually used for inkjet recording, such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes, are used. be able to.
[0037]
As the pigment, an inorganic pigment and an organic pigment 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, and a thermal method can be used. Examples of the organic pigment include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelated azo pigments, etc.), and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines) Pigments, thioindigo pigments, isoindolinone pigments, quinofuralone pigments, etc., dye chelates (eg, basic dye chelates, acid dye chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.
[0038]
According to a preferred embodiment of the present invention, these pigments are preferably added to the ink as a pigment dispersion obtained by dispersing in an aqueous medium with a dispersant or a surfactant. As a preferred dispersant, a dispersant commonly used for preparing a pigment dispersion, for example, a polymer dispersant can be used. It will be apparent to those skilled in the art that the dispersant and surfactant contained in the pigment dispersion will also function as the dispersant and surfactant of the ink composition.
[0039]
The amount of the pigment to be added to the ink is preferably about 0.5 to 25% by weight, and more preferably about 2 to 15% by weight.
[0040]
According to a preferred embodiment of the present invention, the ink composition preferably comprises a resin emulsion. Here, the resin emulsion means an emulsion in which the continuous phase is water and the dispersed phase is the following resin component. As the resin component of the dispersed phase, acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acryl-styrene resin, butadiene resin, styrene resin, crosslinked acrylic resin, crosslinked styrene resin, Benzoguanamine resin, phenol resin, silicone resin, epoxy resin and the like can be mentioned.
[0041]
According to a preferred embodiment of the present invention, the resin is preferably a polymer having both a hydrophilic part and a hydrophobic part. The particle size of these resin components is not particularly limited as long as an emulsion is formed, but is preferably about 150 nm or less, more preferably about 5 to 100 nm.
[0042]
These resin emulsions can be obtained by dispersion polymerization of resin monomers in water, optionally with a surfactant. For example, an emulsion of an acrylic resin or a styrene-acrylic resin can be obtained by dispersing and polymerizing (meth) acrylate, or (meth) acrylate and styrene together with a surfactant in water. The mixing ratio of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1.
[0043]
Preferred examples of the surfactant include anionic surfactants (for example, sodium dodecylbenzenesulfonate, sodium laurate, ammonium salts of polyoxyethylene alkyl ether sulfate, etc.), nonionic surfactants (for example, Ethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc., and these may be used alone or in combination of two or more. Can be used. Also, acetylene glycol (Olefin Y and Surfynol 82, 104, 440, 465, and 485 (all manufactured by Air Products and Chemicals Inc.)) can be used.
[0044]
The ratio of the resin as the disperse phase component to water is 60 to 400 parts by weight of water, preferably 100 to 200 parts by weight, per 100 parts by weight of the resin.
[0045]
As such a resin emulsion, known resin emulsions can also be used. Resin emulsions described in JP-A-4-18462 can be used as they are.
[0046]
It is also possible to use a commercially available resin emulsion, for example, Microgel E-10002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin emulsion, Dainippon Japan) Ink Chemical Industry Co., Ltd.) Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink and Chemicals, Inc.) SAE-1014 (styrene-acrylic resin emulsion, manufactured by Zeon Corporation), Cybinol SK-200 (acrylic) Resin emulsion, manufactured by Siden Chemical Co., Ltd.).
[0047]
The ink used in the present invention preferably contains a resin emulsion so that the resin component is 0.1 to 40% by weight of the ink, more preferably 1 to 25% by weight.
[0048]
The resin emulsion has the effect of suppressing the penetration of the coloring component and promoting the fixation to the recording medium by the interaction of the reactant with the polyvalent metal ion. Further, depending on the type of the resin emulsion, a film is formed on the recording medium, which has the effect of improving the abrasion resistance of the printed matter.
[0049]
According to a preferred embodiment of the present invention, the ink composition used in the present invention preferably further contains a wetting agent comprising a high-boiling organic solvent.
[0050]
Preferred examples of the high-boiling organic solvent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, and triglyceride. Polyhydric alcohols such as methylolethane 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, urea, 2-pyrrolidone, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.
[0051]
The added amount of these wetting agents is preferably about 0.5 to 40% by weight of the ink, and more preferably 2 to 20% by weight. Further, the ink composition used in the present invention preferably contains a low-boiling organic solvent. Examples of low-boiling organic solvents include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, ter-butanol, iso-butanol, n-pentanol and the like. Particularly, a monohydric alcohol is preferable.
[0052]
The amount of the low-boiling organic solvent added is preferably about 0.5 to 10% by weight of the ink, more preferably 1.5 to 6% by weight.
[0053]
According to a preferred embodiment of the present invention, the ink composition preferably contains a sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides) and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucosyl Sorbitol, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a sugar in a broad sense, and is used to include substances widely existing in nature such as alginic acid, α-cyclodextrin, and cellulose.
[0054]
Derivatives of these saccharides include reducing sugars of the above-mentioned saccharides (for example, sugar alcohols (represented by the general formula HOCH ₂ (CHOH) nCH ₂ OH, where n represents an integer of 2 to 5)) And oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thiosugars, etc. Particularly preferred are sugar alcohols, and specific examples include maltitol, sorbitol and the like.
[0055]
The content of these saccharides is suitably in the range of 0.1 to 40% by weight, preferably 0.5 to 30% by weight of the ink.
[0056]
In addition, a pH adjuster, a preservative, a fungicide, and the like may be added as necessary.
[0057]
Ink jet recording apparatus An ink jet recording apparatus for performing the ink jet recording method according to the present invention will be described below with reference to the drawings.
[0058]
The ink jet recording apparatus of FIG. 1 is an embodiment in which an ink composition and a reaction liquid are stored in a tank, and the ink composition and the reaction liquid are supplied to a recording head via an ink tube. That is, the recording head 1 and the ink tank 2 are connected by the ink tube 3. Here, the interior of the ink tank 2 is partitioned, and a room for the ink composition, and in some cases, a plurality of color ink compositions, and a room for the reaction liquid are provided.
[0059]
The recording head 1 is moved along a carriage 4 by a timing belt 6 driven by a motor 5. On the other hand, the paper 7 as a recording medium is placed at a position facing the recording head 1 by the platen 8 and the guide 9. In this embodiment, a cap 10 is provided. A suction pump 11 is connected to the cap 10 to perform a so-called cleaning operation. The sucked ink composition is stored in a waste ink tank 13 via a tube 12.
[0060]
FIG. 2 shows an enlarged view of the nozzle surface of the recording head 1. The portion indicated by 1b is the nozzle surface of the reaction liquid, and the nozzle 21 for discharging the reaction liquid is provided in the vertical direction. On the other hand, the portion indicated by 1c is the nozzle surface of the ink composition, and from the nozzles 22, 23, 24, and 25, the yellow ink composition, the magenta ink composition, the cyan ink composition, and the black ink composition are respectively provided. Discharged.
[0061]
As described above, the reaction solution according to the present invention does not corrode the nozzle plate that has been subjected to the water-repellent treatment by the eutectoid plating. Therefore, the inkjet recording method according to the present invention can be advantageously applied to an inkjet recording apparatus using a nozzle plate on which a water-repellent treatment layer is formed by eutectoid plating. This water-repellent treatment layer is immersed in an electrolytic solution in which nickel ions and particles of a water-repellent polymer resin such as polytetrafluoroethylene are dispersed by electric charge, and the solution is stirred while eutectoid plating on the surface of the nozzle plate 1. It is preferably formed by a technique for forming a layer. As the fluorine-based polymer material used for the eutectoid plating treatment, a resin such as polytetrafluoroethylene, polybarfluoroalkoxybutadiene, polyvinylidene, polyfluorovinyl, and polydiperfluoroalkyl fumarate alone or mixed. Things.
[0062]
Further, an ink jet recording method using the recording head shown in FIG. 2 will be described with reference to FIG. The recording head 1 moves in the direction of arrow A. During the movement, the reaction liquid is ejected from the nozzle surface 1b to form a band-like reaction liquid adhesion region 31 on the recording medium 7. Next, the recording medium 7 is transported by a predetermined amount in the paper feed direction arrow B. During that time, the recording head 1 moves in the direction opposite to the arrow A in the figure, and returns to the position on the left end of the recording medium 7. Then, the ink composition is printed on the reaction liquid adhering area where the reaction liquid has already adhered to form a print area 32.
[0063]
Further, as shown in FIG. 4, in the recording head 1, all the nozzles can be arranged in the horizontal direction. In the figure, 41a and 41b are discharge nozzles of a reaction liquid, and the nozzles 42, 43, 44, and 45 discharge yellow ink composition, magenta ink composition, cyan ink composition, and black ink composition, respectively. You. In the print head of such an embodiment, printing can be performed both in the forward path and the return path in which the print head 1 reciprocates on the carriage, and therefore, the print head 1 has a higher speed than the print head shown in FIG. Printing can be expected.
[0064]
Further, by adjusting the surface tension of the reaction liquid and the ink composition, high-quality printing can be obtained more consistently regardless of the order in which they are attached. In this case, the number of nozzles for ejecting the reaction liquid can be reduced to one (for example, the nozzle 41b can be omitted in the figure), so that the head can be further reduced in size and the printing speed can be increased.
[0065]
Further, in some ink jet recording apparatuses, replenishment of the ink composition is performed by replacing a cartridge which is an ink tank. Further, the ink tank may be integrated with the recording head.
[0066]
FIG. 5 shows a preferred example of an ink jet recording apparatus using such an ink tank. In the figure, the same members as those of the apparatus of FIG. 1 are denoted by the same reference numerals. In the embodiment of FIG. 5, the recording heads 1a and 1b are integrated with the ink tanks 2a and 2b. The recording head 1a or 1b discharges the ink composition and the reaction liquid, respectively. The printing method may be basically the same as that of the apparatus shown in FIG. In this embodiment, the recording head 1a and the ink tank 2a and the recording head 1a and the ink tank 2b move on the carriage 4 together.
[0067]
【Example】
Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited thereto.
[0068]
The following ink composition and reaction liquid were prepared according to a conventional method. That is, the ink composition was obtained by dispersing the colorant component together with the dispersant component, adding and mixing other components, and filtering an insoluble component having a size equal to or larger than a predetermined size to obtain an ink composition.
[0069]
Reaction liquid 1
Magnesium nitrate hexahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Ammonia water (29%) 0.5% by weight
Benzotriazole 0.03% by weight
Deionized water Remaining pH = 8.4
[0070]
Reaction liquid 2
Magnesium acetate tetrahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Ammonia water (29%) 0.5% by weight
Benzotriazole 0.03% by weight
Deionized water Remaining pH = 8.7
[0071]
Reaction liquid 3
Calcium nitrate tetrahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Ammonia water (29%) 0.6% by weight
Deionized water Remaining pH = 8.8
[0072]
Reaction liquid 4
Magnesium nitrate hexahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Benzotriazole 0.01% by weight
Deionized water Remaining pH = 7.5
[0073]
Reaction liquid 5
Calcium nitrate tetrahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Deionized water remaining pH = 7.4
[0074]
Reaction liquid 6
Magnesium nitrate hexahydrate 25% by weight
Triethylene glycol monobutyl ether 10% by weight
Glycerin 10% by weight
Benzotriazole 0.03% by weight
Deionized water Remaining pH = 7.5
[0075]
The above components were mixed, stirred at room temperature for 30 minutes, and filtered through a 5 μm membrane filter to obtain reaction solutions 1 to 5.
[0076]
Ink 1
5% by weight of carbon black MA7
(Mitsubishi Chemical Corporation)
Liquid medium styrene-acrylic copolymer / ammonium salt 1.5% by weight
(Molecular weight 7000, resin component 38 wt%: dispersant)
Bon coat 4001 3% by weight
(Acrylic resin emulsion, resin component 50%, manufactured by Dainippon Ink and Chemicals, Inc.)
Maltitol 3.5% by weight
Glycerin 10% by weight
2-pyrrolidone 2% by weight
Ion-exchanged water The remaining amount of carbon black and the dispersant were mixed and dispersed in a sand mill (manufactured by Yasukawa Seisakusho) for 2 hours together with glass beads (1.7 mm in diameter, 1.5 times (weight) of the mixture). Thereafter, the glass beads were removed, other components were added, and the mixture was stirred at room temperature for 20 minutes. The mixture was filtered through a 5 μm membrane filter to obtain an ink for inkjet recording.
[0077]
Evaluation 1 : Storage stability of the reaction solution 100 g of each of the reaction solutions 1 to 5 was collected in a sample bottle, and the sample bottle was sealed and left for 1 week in an environment at a temperature of 40 ° C and a humidity of 25%. The reaction solution after standing was filtered through a 5 μm membrane filter, and the generation of foreign substances and the ease of filtration were observed. The results were evaluated according to the following criteria.
Evaluation A: Filtration could be performed smoothly without any generation of foreign matter (filtration could be carried out as it was immediately after production)
Evaluation B: A small amount of foreign matter was generated, but the filtration could be performed smoothly. Evaluation C: A large amount of foreign matter was generated, and the filtration could not be performed smoothly.
Evaluation 2 : Print quality (bleeding)
Using an inkjet printer MJ-500C (manufactured by Seiko Epson Corporation), printing was performed on two sheets of Xerox 4024 3R 721 (manufactured by Xerox Corporation) and Xerox R (manufactured by Xerox Corporation, re-papermaking). After printing the reaction liquid at 100% duty, characters were printed with ink 1. After drying, the characters were examined for bleeding. The results were evaluated according to the following criteria.
Evaluation A: Evaluation of clear printing without blurring on both papers Evaluation B: Evaluation of beard-like blurring on either or both papers C: Blurring such that the outline of characters on either or both papers was not clear Has occurred [0079]
Evaluation 3 : Discharge stability The head of an inkjet printer MJ-500C was filled with the reaction liquid, and alphanumeric characters were printed continuously on A4 size paper. When the flight of the reaction liquid occurred during printing, a return operation was performed. When the flight bend was not corrected even after performing the return operation, the number of sheets printed so far was used as an index indicating the ejection stability. The results were evaluated according to the following criteria.
Evaluation AA: 20,000 or more printed sheets Evaluation A: 10,000 to less than 20,000 printed sheets Evaluation B: 5,000 to less than 10,000 printed sheets C: Printed less than 5,000 sheets [0080]
Table 1 shows the results of the evaluations 1 to 3.
[0081]

[0082]
Evaluation 4 :
The reaction liquids 1 and 5 were filled in the heads of the ink jet printer MJ-500C, respectively, and after confirming the discharge of the reaction liquids from all the nozzles, the recording heads were left in a 40 ° C. environment for one week with the caps capped. After standing, the recording head was taken out of the printer, and the nozzle surface on which the eutectoid plating was applied was observed with a microscope. As a result, no change was observed on the nozzle surface of the recording head filled with the reaction liquid 1, but corrosion was observed on the nozzle surface of the recording head filled with the reaction liquid 5.
[Brief description of the drawings]
FIG. 1 is a view showing an ink jet recording apparatus preferably used for carrying out an ink jet recording method according to the present invention. In this embodiment, a recording head and an ink tank are respectively independent, and an ink composition and a reaction liquid are ink. It is supplied to the recording head by a tube.
FIG. 2 is an enlarged view of a nozzle surface of a recording head, wherein 1b is a nozzle surface of a reaction liquid and 1c is a nozzle surface of an ink composition.
FIG. 3 is a diagram illustrating an ink jet recording method using the recording head of FIG. In the drawing, reference numeral 31 denotes a reaction liquid adhering area, and reference numeral 32 denotes a printing area where the ink composition is printed on the reaction liquid adhering thereto.
FIG. 4 is a view showing another embodiment of a recording head preferably used for carrying out the ink jet recording method according to the present invention, in which all ejection nozzles are arranged in a horizontal direction.
FIG. 5 is a view showing an ink jet recording apparatus preferably used for carrying out the ink jet recording method according to the present invention. In this embodiment, the recording head and the ink tank are formed integrally.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Recording head 2 Ink tank 3 Ink tube 21 Reaction liquid discharge nozzle 22, 23, 24, 25 Ink composition discharge nozzle 31 Reaction liquid adhesion area 32 Printing area

Claims (9)

A reaction used in an ink-jet recording method in which a droplet of an ink composition and a droplet of a reaction liquid that generates an aggregate when contacted with the ink composition are ejected, and the droplet is attached to a recording medium to perform printing. Liquid,
A reaction solution comprising at least a polyvalent metal salt, ammonia, and benzotriazole or a benzotriazole derivative. The reaction solution according to claim 1, comprising ammonia at a concentration of 0.5% by weight or less. The reaction solution according to claim 1, comprising benzotriazole or a benzotriazole derivative at a concentration of 0.03% by weight or more. 2. The reaction solution according to claim 1, comprising ammonia at a concentration of 0.5% by weight or less and benzotriazole or a benzotriazole derivative at a concentration of 0.03% by weight or more. The reaction solution according to claim 4, wherein the polyvalent metal salt is magnesium acetate. The reaction solution according to any one of claims 1 to 5, wherein the pH is 8 or more. An ink jet recording method for ejecting droplets of an ink composition and droplets of a reaction liquid that causes an aggregate when contacted with the ink composition, and printing by attaching the droplets to a recording medium. An ink jet recording method, wherein the reaction liquid is the reaction liquid according to any one of claims 1 to 6. The ink jet recording method according to claim 7, wherein the reaction liquid is ejected by an ink jet recording head having a nozzle plate that has been subjected to eutectoid plating. A recorded matter printed by the method according to claim 7.

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