JP6040808B2 - Image forming method, ink jet ink, ink jet recording method, ink jet recording apparatus, and ink recorded matter - Google Patents

Description

  The present invention relates to an image forming method, an ink jet ink, an ink jet recording method, an ink jet recording apparatus, and an ink recorded matter.

  The inkjet recording method is easy to make full color because the process is simpler than other recording methods, and there is an advantage that a high-resolution image can be obtained even with an apparatus having a simple configuration. As ink-jet inks, dye-based inks in which various water-soluble dyes are dissolved in water or a mixture of water and an organic solvent are used.

  In recent years, there has been an increasing need for higher speeds, but when aqueous ink is used for printing on plain paper, curling after printing has become a major problem. In the case of water-based ink, since it contains a large amount of water, the water swells the paper fibers and causes curling.

  On the other hand, when oil-based ink is used, it does not contain water, so there is no major problem with curling, but the image has a low image density, blurring, and show-through, because it has a higher penetrating power to media than aqueous ink. Deterioration in quality is a major issue. Until now, inkjet inks that satisfy all curl and image quality have not been obtained.

  When water-based ink is used, as a method for preventing curling of plain paper, a method of adding specific saccharides, sugar alcohols, and amide compounds as an anti-curling agent has been proposed (see Patent Documents 1 to 5). However, this method also has a problem of curling when an image with a large amount of ink is printed at high speed.

  In order to prevent curling, methods for increasing the ratio of the solvent in the aqueous ink have been studied (see Patent Documents 6 to 7). However, since the ratio of the solvent is increased, the image quality obtained is the same as that of the oil-based ink, and the viscosity of the ink is increased.

In order to solve the above problems, it has been reported that an ink containing any one of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether has a low viscosity even if the solvent ratio is high ( Japanese Patent Application Laid-Open No. 2012-40760 of Patent Document 8, Japanese Patent Application Laid-Open No. 2012-121287 of Patent Document 9, Japanese Patent Application Laid-Open No. 2012-67178 of Patent Document 10.
However, inks containing diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether have a problem in storage stability.
In this way, curl and image quality are not compatible at present.

  This invention is made | formed in view of this present condition, and makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, the present invention relates to a recording ink, an ink media set, an ink cartridge, an ink jet recording method, an ink jet recording apparatus, and a recording ink capable of preventing curling and recording high quality images when printed on plain paper. An object is to provide an ink record.

As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have found the characteristics of the ink suitably used for plain paper and have reached the present invention.
That is, as means for solving the above problems, the present invention includes the following “ink”, “ink media set”, “ink cartridge”, “inkjet recording method”, “inkjet recording apparatus”, and “ink recorded matter”. Include.
(1) “In the inkjet ink containing at least water, a wetting agent, and a coloring material, ethylene oxide containing one or more vinyl ether groups of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether as the wetting agent An ink containing a glycol derivative and having a pH in the range of 6.5 to 7.5. "
Since the viscosity of the ink is kept low, this ink has excellent ejection stability and storage stability even with a high solvent amount. In other words, it is effective in lowering the viscosity of the ink, and the ink viscosity can be kept low even with a high amount of solvent. Therefore, the ejection stability is high, curling can be suppressed, and the storage stability is also excellent. .
In addition, the recording ink of the present invention provides an image having excellent image quality with respect to plain paper, in particular, image fastness such as image density, saturation, water resistance, and light resistance, and is suitable for drying speed and high-speed printing. It has excellent discharge stability from the nozzle and can form a high-quality image, and can be suitably used for an ink cartridge, an ink recorded material, an ink jet recording apparatus, and an ink jet recording method.
(2) The ink according to (1), wherein the total content of the ink including the diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether is 20 to 50% by mass. . "
This ink is excellent in ejection stability even in a high solvent amount.
(3) “The ink according to (1) or (2) above, wherein the water content in the ink is 10 to 25% by mass”.
This ink is effective in storage stability.
(4) “Containing further a nitrogen-containing hydrophilic organic solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, β-methoxy-N, N-dimethylpropionamide, 2-pyrrolidone, The ink according to any one of (1) to (3) above, wherein the content of the nitrogen-containing hydrophilic organic solvent is in the range of 5 to 30% by mass.
This ink has good ejection stability and offset property.
(5) "The ink according to any one of (1) to (4) above, wherein the colorant contains a self-dispersing pigment."
This ink has a high viscosity reducing effect by combination with diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether, and has good ejection properties.
(6) “Inkjet recording having ink flying means for applying a stimulus to the inkjet ink according to any one of (1) to (5) and causing the inkjet ink to fly to form an image on a recording medium. apparatus."
The ink jet recording apparatus of the present invention includes at least ink ejecting means for applying a stimulus (energy) to the recording ink of the present invention and causing the recording ink to eject to form an image on a recording medium. In the ink jet recording apparatus, the ink flying means applies a stimulus (energy) to the recording ink of the present invention and causes the recording ink to fly to form an image on a recording medium. As a result, even when printing on plain paper, the saturation is remarkably improved and the color developability is excellent. In addition, there is little beading (density unevenness) in printing gloss paper, excellent drying, excellent drying speed and high-speed printing, good ejection stability from the nozzle, and a clear and close-to-print image can be obtained. It is done.
(7) “An ink recorded matter comprising an image formed by the inkjet ink according to any one of (1) to (5) above on a recording medium.”
The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention or the ink media set of the present invention.
In the ink recorded matter of the present invention, when printing on plain paper, so-called white spots (image chipping) are improved, and an image excellent in image density, saturation and image fastness can be obtained. Paper beading (density unevenness) is small, the drying property is excellent, the drying speed and high-speed printing are excellent, the ejection stability from the nozzle is good, and a clear image close to the printed matter can be obtained.
The present invention also includes the following “inkjet ink”, “ink media set”, “ink cartridge”, and “inkjet recording method”.
(8) “The ink according to any one of (1) to (5) above, wherein the diol content is 20% by mass or less.”
(9) “An ink media set comprising the recording ink according to any one of (1) to (5) or (8), and a recording medium, wherein the recording medium is a support; And having a coating layer coated on at least one surface of the support, and a transfer amount of pure water to the recording medium at a contact time of 100 ms as measured by a dynamic scanning absorption meter. An ink media set having a transfer amount of pure water to the recording medium of ² to 35 ml / m ² and a contact time of 400 ms is 3 to 40 ml / m ² .
As a result, this ink media set has less beading (density unevenness), is excellent in dryness, and can form a high-quality image for printing image quality.
(10) “An ink cartridge in which the recording ink according to any one of (1) to (5) or (8) is contained in a container”.
It is suitably used for a printer using the ink jet recording method. When recording is performed using the ink contained in the ink cartridge, the image quality for plain paper, in particular, so-called white spots (image missing) is improved, and the color saturation is improved significantly. Excellent.
Furthermore, there is little beading (density unevenness) of gloss paper for printing, excellent drying properties, excellent drying speed and high-speed printing, good ejection stability from nozzles, and clear, close-to-print image recording Is possible.
(11) “Stimulation (energy) is applied to the recording ink according to any one of (1) to (5) or (8), and the recording ink is ejected to form an image on the recording medium. An ink jet recording method comprising at least an ink flying step. ”
In the ink jet recording method, in the ink flying step, a stimulus (energy) is applied to the recording ink of the present invention, and the recording ink is ejected to form an image on a recording medium. As a result, even when printing on plain paper, the saturation is remarkably improved and the color developability is excellent. In addition, there is little beading (density unevenness) in printing gloss paper, excellent drying, excellent drying speed and high-speed printing, good ejection stability from the nozzle, and a clear and close-to-print image can be obtained. It is done.

  According to the present invention, various problems in the prior art can be solved, and an image excellent in image fastness such as image quality, image density, saturation, water resistance, and light resistance with respect to plain paper can be obtained, and furthermore, the ink absorption is low. Recording ink, ink media set, ink cartridge, low beading (density unevenness) on general-purpose printing paper, excellent drying, excellent drying speed, high-speed printing, and good ejection stability from nozzles An ink jet recording method, an ink jet recording apparatus, and an ink recorded matter can be provided.

It is a figure which shows one example of the inkjet recording device of this invention. It is a figure explaining the internal structure of the said inkjet recording device. It is a figure explaining the relationship between the head which has an ink cartridge in the said inkjet recording device, and a recording medium (media).

  The recording ink of the present invention contains at least water, a wetting agent, a surfactant, and a coloring material, and further contains a penetrant, a water-dispersible resin, and other components as necessary.

<Wetting agent (water-soluble organic solvent and solid wetting agent)>
One of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether, or two or more monovinyl ethers, preferably one of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether A combination of nitrogen-containing hydrophilic organic solvents having no hydroxyl group is preferable. Specific examples thereof include 1,3-dimethyl-2-imidazolidinone, β-methoxy-N, N-dimethylpropionamide, and a combination with 2-pyrrolidone.

  When the pH of the ink is in the range of 6.5 to 7.5, the storage stability is excellent. When the pH is out of the range, diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether are hydrolyzed and the viscosity increases rapidly.

  Diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether are effective in suppressing ink viscosity, so they are effective for ejection stability and can suppress ink viscosity even with a high amount of solvent. The amount of water in the ink can be reduced, and curling can be suppressed.

Ink-jet ink containing diethylene glycol monovinyl ether, triethylene glycol monovinyl ether and tetraethylene glycol monovinyl ether according to the present invention has improved image quality on plain paper, excellent image density and drying, drying speed, and high-speed printing Excellent response and discharge stability from the nozzle.
The content of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether is preferably 20 to 50% by mass, and more preferably 20 to 30% by mass.
By setting the content to 20 to 30% by mass, the ink viscosity suppressing effect is high, and the intermittent ejection property is also improved.

The ink of the present invention containing diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, or tetraethylene glycol monovinyl ether has improved storage stability when the water content in the ink is in the range of 10 to 25% by mass.
If the water content is less than 10% by mass, the dispersion cannot contain ink because the dispersion contains water. When the water content is more than 25% by mass, the storage stability may be deteriorated.

  In addition, as a wetting agent used by mixing with diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether, in a region where the amount of water is small, the content of diols should be small, and 20 mass. By setting the ratio to less than or equal to%, the discharge property is improved.

  Examples of diols include 1,2,3-butanetriol, 1,2,4-butanetriol, glycerin (bp 290 ° C., 49% by mass), diglycerin, triethylene glycol, tetraethylene glycol, diethylene glycol, 1, Examples include 3-butanediol.

  Nitrogen-containing hydrophilic organic solvents, amides, amines, and sulfur-containing hydrophilic solvents are effective as the wetting agent used by mixing with diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether. Examples of nitrogen-containing heterocyclic hydrophilic organic solvents, amides, amines, and sulfur-containing compounds include 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε -Caprolactam, gamma-butyrolactone and the like.

  Examples of the amides include formamide, N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, β-alkoxy-N, N-dimethylalkylamide and the like.

  Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, N, N-dimethylmonoethanolamine, N-methyldiethanolamine, N-methylethanolamine, N-phenylethanolamine, and 3-aminopropyldiethylamine. Is mentioned.

  Examples of the sulfur-containing hydrophilic solvent include dimethyl sulfoxide, sulfolane, thiodiglycol, and the like.

  Particularly preferably, the ejection properties are improved by containing 1,3-dimethyl-2-imidazolidinone, β-methoxy-N, N-dimethylpropionamide, and 2-pyrrolidone in the range of 5 to 30% by mass.

In addition to the above-mentioned wetting agents, the recording ink of the present invention includes polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, propylene carbonate, ethylene carbonate, and other wetting agents as necessary. , Etc.
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, ethylene glycol mono-2-ethylhexyl ether, propylene glycol monoethyl ether. Etc.

Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether.
Other solid wetting agents are preferably sugars.

Examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), polysaccharides, and the like.
Specific examples include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like.
Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature such as α-cyclodextrin and cellulose.
Moreover, as derivatives of these saccharides, reducing sugars of the saccharides described above (for example, sugar alcohol (general formula: HOCH2 (CHOH) nCH2OH (where n represents an integer of 2 to 5)), oxidation. Sugar (for example, aldonic acid, uronic acid, etc.), amino acid, thioic acid and the like can be mentioned.
Among these, sugar alcohols are preferable, and specific examples include maltitol and sorbit.

<Color material>
In the inkjet ink, a pigment is mainly used as a colorant, that is, a colorant (water dispersible colorant) from the viewpoint of weather resistance, but it may contain a dye within a range in which the weather resistance is not deteriorated for the purpose of color tone adjustment. I do not care. There is no restriction | limiting in particular as said pigment, According to the objective, it can select suitably, For example, the inorganic pigment, organic pigment, etc. for black or color are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  Inorganic pigments include titanium oxide and iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, as well as carbon produced by known methods such as the contact method, furnace method, and thermal method. Black can be used.

  Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (eg, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye type chelates, acidic dye type chelates), nitro pigments, nitroso pigments, aniline black, and the like can be used. Of these pigments, those having good affinity with water are particularly preferably used.

  Specific examples of pigments that are more preferably used in the above-mentioned pigments include black for carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, or copper, iron. (CI pigment black 11), metals such as titanium oxide, and organic pigments such as aniline black (CI pigment black 1).

  Further, for color use, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 128, 138, 150, 151, 153, 183, C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48: 2, 48: 2 (Permanent Red 2B (Ca)), 48: 3, 48: 4, 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81, 83, 88, 101 (Bengara), 104, 105, 106, 108 ( Cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3 (phthalocyanine blue), 16, 17: 1, 56, 60, 63, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, and the like.

The following first and second forms are particularly preferable when the colorant is a pigment.
1) In the first embodiment, the colorant contains a polymer emulsion (an aqueous dispersion of polymer fine particles containing a coloring material) in which a polymer fine particle contains a water-insoluble or poorly water-soluble coloring material.
2) In the second embodiment, the colorant has a surface having at least one hydrophilic group and exhibits water dispersibility in the absence of a dispersant (hereinafter, referred to as “self-dispersible pigment”). ).

In this invention, in the case of the 1st and 2nd form, it is preferable that the water dispersible resin shown below is included.
As the water-dispersible colorant of the first form, it is preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles in addition to the pigment. The polymer emulsion in which the pigment is contained in the polymer fine particles is one in which the pigment is encapsulated in the polymer fine particles, or the pigment is adsorbed on the surface of the polymer fine particles. In this case, it is not necessary that all the pigments are encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired. Examples of the polymer forming the polymer emulsion (polymer in the polymer fine particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferably used polymers are vinyl polymers and polyester polymers. Polymers disclosed in 2000-53897 and JP 2001-139849 can be used.

  The self-dispersing pigment of the second form is a surface modified so that at least one hydrophilic group is bonded to the surface of the pigment directly or via another atomic group. In the surface modification, a specific functional group (a functional group such as a sulfone group or a carboxyl group) is chemically bonded to the surface of the pigment, or at least one of hypohalous acid and a salt thereof is used. A method such as wet oxidation is used. Among these, a form in which a carboxyl group is bonded to the surface of the pigment and dispersed in water is particularly preferable. Since the pigment is thus surface-modified and the carboxyl group is bonded, not only the dispersion stability is improved, but also high-quality print quality is obtained and the water resistance of the recording medium after printing is further improved. improves.

  Further, since the ink containing the self-dispersing pigment of the first form is excellent in redispersibility after drying, clogging does not occur even when printing is stopped for a long time and ink moisture near the inkjet head nozzle evaporates. Good printing can be easily performed with a simple cleaning operation. The volume average particle diameter (D50) of the self-dispersing pigment is preferably 0.01 to 0.16 μm in the ink.

For example, as the self-dispersing carbon black, those having ionicity are preferable, and those having an anionic charge are preferable.
Examples of the anionic hydrophilic group include —COOM, —SO 3 M, —PO 3 HM, —PO 3 M 2, —SO 2 NH 2, —SO 2 NHCOR (where M represents an alkali metal, ammonium, or organic ammonium. R represents 1 carbon atom. -12 alkyl group, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent). Among these, it is preferable to use those in which —COOM and —SO3M are bonded to the surface of the color pigment.

  Further, “M” in the hydrophilic group includes, for example, lithium, sodium, potassium and the like as an alkali metal. Examples of the organic ammonium include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium. As a method of obtaining the anionically charged color pigment, as a method of introducing —COONa to the color pigment surface, for example, a method of oxidizing the color pigment with sodium hypochlorite, a method of sulfonation, a diazonium salt The method of making it react is mentioned.

The hydrophilic group may be bonded to the surface of carbon black via another atomic group.
Examples of other atomic groups include an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent, or a naphthyl group which may have a substituent. Specific examples of the case where the hydrophilic group is bonded to the surface of carbon black through another atomic group include, for example, -C2H4COOM (where M represents an alkali metal or quaternary ammonium), -PhSO3M (Wherein Ph represents a phenyl group. M represents an alkali metal or quaternary ammonium).

  The content of the water-dispersible colorant in the inkjet recording ink is preferably 1 to 15% by mass and more preferably 2 to 10% by mass in terms of solid content. When the content is from 2 to 10% by mass, the ink ejection property is good and economically preferable.

<Pigment dispersant>
As the water-dispersible colorant of the first form, it is preferable to use a polymer emulsion in which a pigment is contained in polymer fine particles in addition to the pigment.
The polymer emulsion in which the pigment is contained in the polymer fine particles is one in which the pigment is encapsulated in the polymer fine particles, or the pigment is adsorbed on the surface of the polymer fine particles.
In this case, it is not necessary that all the pigments are encapsulated or adsorbed, and the pigments may be dispersed in the emulsion as long as the effects of the present invention are not impaired.

  Examples of the polymer forming the polymer emulsion (polymer in the polymer fine particles) include vinyl polymers, polyester polymers, polyurethane polymers, and the like. Particularly preferably used polymers are vinyl polymers and polyester polymers. Polymers disclosed in 2000-53897 and JP 2001-139849 can be used.

  The content of the colorant in the recording ink is preferably 2 to 15% by mass, more preferably 3 to 12% by mass in terms of solid content.

  In the second embodiment, it is preferable that the colorant contains a pigment dispersant. As the pigment dispersant, either an anionic surfactant or a nonionic surfactant having an HLB value of 10 to 20 is suitable.

Examples of the anionic surfactant include polyoxyethylene alkyl ether acetates, alkylbenzene sulfonates (for example, NH4, Na, Ca, etc.), alkyl diphenyl ether disulfonates (for example, NH4, Na, Ca, etc.), dialkyl succinates. Na sulfonate sulfonate, Naphthalene sulfonate formalin condensate Na salt, polyoxyethylene polycyclic phenyl ether sulfate ester salt (eg NH4, Na etc.), laurate, polyoxyethylene alkyl ether sulfate salt, oleate, etc. Can be mentioned.
Among these, dioctyl sulfosuccinic acid Na salt and polyoxyethylene styrene phenyl ether sulfonic acid NH4 salt are particularly preferable.

Examples of the nonionic surfactant having an HLB value of 10 to 20 include polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polycyclic phenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene Examples include ethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, and acetylene glycol.
Among these, polyoxyethylene lauryl ether, polyoxyethylene-β-naphthyl ether, polyoxyethylene sorbitan monooleate, and polyoxyethylene styrene phenyl ether are particularly preferable.

  1-100 mass% is preferable with respect to 100 mass% of said pigments, and, as for content of the said pigment dispersant, 10-50 mass% is more preferable. By setting the content to 1 to 100% by mass with respect to 100% by mass of the pigment, the pigment can be sufficiently miniaturized.

The pigment dispersion finely dispersed uniformly in water by the pigment dispersant is dissolved in the above-mentioned pigment dispersant in an aqueous medium, and then sufficiently wetted by adding the above-mentioned pigment, followed by high-speed stirring by a homogenizer. It can be produced by a method using a dispersing machine using a ball such as a bead mill or a ball mill, a kneading dispersing machine using a shearing force such as a roll mill, an ultrasonic dispersing machine, or the like.
However, after such a kneading and dispersing step, coarse particles are often contained, which may cause clogging of the ink jet nozzle and the supply path. Therefore, particles having a particle diameter of 1 μm or more using a filter or a centrifuge. Need to be removed.

The average particle diameter (D50) of the pigment dispersion is preferably 150 nm or less, more preferably 100 nm or less in the ink.
When the average particle diameter (D50) exceeds 150 nm, the ejection stability rapidly decreases, and nozzle clogging and ink bending are likely to occur. Further, when the average particle diameter (D50) is 100 nm or less, the ejection stability is improved and the chroma of the image is also improved.

<Surfactant>
The surfactant is preferably an anionic surfactant or a nonionic surfactant that does not impair dispersion stability depending on the type of coloring material or a combination of wetting agents, has low surface tension, and has high permeability and leveling properties. At least one selected from silicone surfactants and fluorosurfactants is preferred. Among these, silicone surfactants and fluorine surfactants are particularly preferable.
These surfactants can be used alone or in combination of two or more.

  As the fluorine-based surfactant, those having 2 to 16 carbon atoms substituted with fluorine are preferable, and those having 4 to 16 carbon atoms substituted with fluorine are more preferable. When the number of carbon atoms substituted with fluorine is 2 to 16, the ability to reduce the surface tension is high, and the storage stability is also good.

Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in a side chain. And polyoxyalkylene ether polymer compound. Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is particularly preferable because of its low foaming property.
More preferably, it is a fluorine-type surfactant represented by the following general formula (3).

CF3CF2 (CF2CF2) m-CH2CH2O (CH2CH2O) nH
... General formula (3)
(In the general formula (3), m represents an integer of 0 to 10. n represents an integer of 1 to 40.)

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.
The polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain includes a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain, and a polyoxyalkylene ether having a perfluoroalkyl ether group in the side chain. Examples thereof include a sulfate salt of a polymer and a salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain.
Examples of the counter ion of the salt in these fluorosurfactants include Li, Na, K, NH4, NH3CH2CH2OH, NH2 (CH2CH2OH) 2, NH (CH2CH2OH) 3, and the like.
As said fluorosurfactant, what was synthesize | combined suitably may be used and a commercial item may be used.

  Examples of the commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, and S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by Dainippon Ink & Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all ), Polyfox PF-151N (Omnova), etc. Among them, FS manufactured by DuPont, from which the good print quality, particularly the color development and the leveling property on paper are remarkably improved. -300, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW made by Neos Co., Ltd. and Polyfox PF-151N made by Omninova are particularly preferred.

As specific examples of the fluorine-based surfactant, those represented by the following general formula are suitable.
(I) Anionic fluorosurfactant

ただし、前記一般式中、Ｒｆは、下記構造式及び一般式（５）〜（７）で表されるフッ素含有疎水基のいずれかを表わし、したがって一般式（４）はこれらの混合物を表す。Ａは、−ＳＯ３Ｘ、−ＣＯＯＸ、又は−ＰＯ３Ｘ（ただし、Ｘは対アニオンであり、具体的には、水素原子、Ｌｉ、Ｎａ、Ｋ、ＮＨ４、ＮＨ３ＣＨ２ＣＨ２ＯＨ、ＮＨ２（ＣＨ２ＣＨ２ＯＨ）２、又はＮＨ（ＣＨ２ＣＨ２ＯＨ）３が挙げられる）を表す。

However, in said general formula, Rf represents either the fluorine-containing hydrophobic group represented by following structural formula and General formula (5)-(7), Therefore General formula (4) represents these mixtures. A is -SO3X, -COOX, or -PO3X (where X is a counter anion, specifically, a hydrogen atom, Li, Na, K, NH4, NH3CH2CH2OH, NH2 (CH2CH2OH) 2, or NH (CH2CH2OH) And 3).

ただし、前記一般式（７）中、Ｒｆ’は下記一般式（８）〜（１０）で表されるフッ素含有基を表す。Ｘは、上記と同じ意味を表す。ｎは１又は２の整数、ｍは２−ｎを表す。

However, in the general formula (7), Rf ′ represents a fluorine-containing group represented by the following general formulas (8) to (10). X represents the same meaning as described above. n represents an integer of 1 or 2, and m represents 2-n.

ただし、前記一般式中、ｎは３〜１０の整数を表す。

However, in said general formula, n represents the integer of 3-10.

ただし、前記一般式中、Ｒｆ’及びＸは、上記と同じ意味を表す。

However, in the general formula, Rf ′ and X have the same meaning as described above.

ただし、前記一般式中、Ｒｆ’及びＸは、上記と同じ意味を表す。

However, in the general formula, Rf ′ and X have the same meaning as described above.

(II) Nonionic fluorosurfactant

ただし、前記一般式中、Ｒｆは、上記と同じ意味を表す。ｎは５〜２０の整数を表す。

However, in the said general formula, Rf represents the same meaning as the above. n represents an integer of 5 to 20.

ただし、前記一般式中、Ｒｆ’は、上記と同じ意味を表す。ｎは１〜４０の整数を表す。

However, in the general formula, Rf ′ represents the same meaning as described above. n represents an integer of 1 to 40.

As such a surfactant, an appropriately synthesized product or a commercially available product may be used.
Such commercially available products can be easily obtained from, for example, Big Chemie, Shin-Etsu Silicone, Toray Dow Corning Silicone, etc.

The polyether-modified silicone surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the polyalkylene oxide structure represented by the following structural formula may be represented by the side chain of Si part of dimethylpolysiloxane. And the like, and the like.
A commercial item can be used as said polyether modified silicone type surfactant, For example, KF-618, KF-642, KF-643 (all are the Shin-Etsu Chemical Co., Ltd. product) etc. are mentioned.

  Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, and polyoxyethylene alkyl. And amines and polyoxyethylene alkylamides.

  The content of the surfactant in the recording ink is preferably 0.01 to 3.0% by mass, and more preferably 0.5 to 2% by mass. If it is 0.01-3.0 mass%, the filling of a dot will become good and a white spot will not generate | occur | produce. By adjusting the content to 0.5 to 2% by mass, the image density is increased.

<Penetration agent>
The recording ink of the present invention preferably contains at least one polyol compound or glycol ether compound having 8 to 11 carbon atoms as a penetrant. These preferably have a solubility of between 0.2 and 5.0% by weight in water at 25 ° C. Among these, 2-ethyl-1,3-hexanediol [solubility: 4.2% (25 ° C.)], 2,2,4-trimethyl-1,3-pentanediol [solubility: 2.0% (25 ° C)] is particularly preferred.
As other polyol compounds, as aliphatic diols, for example, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1, 3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene- 1,2-diol and the like can be mentioned.

Other penetrants that can be used in combination are not particularly limited as long as they can be dissolved in the ink and adjusted to the desired physical properties, and can be appropriately selected according to the purpose. For example, diethylene glycol monophenyl ether, ethylene Glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, alkyl and aryl ethers of polyhydric alcohols such as tetraethylene glycol chlorophenyl ether, lower alcohols such as ethanol, etc. Is mentioned.
The content of the penetrant in the ink jet recording ink is preferably 0.1 to 4.0% by mass. When the content is in the range of 0.1 to 4.0% by mass, the permeability of the ink into the medium is improved, and the dot filling is improved.

In addition to those described above, conventionally known additives such as a pH adjuster, an antiseptic / antifungal agent, a rust preventive agent, and a chelating reagent can be added to the ink of the present invention.
As the pH adjuster, those containing one or more alcohol amines, alkali metal hydroxides, ammonium hydroxides, phosphonium hydroxides, and alkali metal carbonates are preferable.
Examples of alcohol amines include diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol, and examples of alkali metal hydroxides include lithium hydroxide, sodium hydroxide, and potassium hydroxide. As ammonium hydroxide, ammonium hydroxide, quaternary ammonium hydroxide, etc., phosphonium hydroxide as quaternary phosphonium hydroxide, and alkali metal carbonate as 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 antirust agent include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite and the like.

  Examples of the chelating reagent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

  The recording ink of the present invention includes a coloring material, a water-soluble organic solvent (wetting agent), a surfactant, and water, and if necessary, a penetrant, a water-dispersible resin, and other components dispersed in an aqueous medium. Or it melt | dissolves and also stirs and mixes as needed. The dispersion can be performed by, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, etc., and stirring and mixing are performed by a stirrer using a normal stirring blade, a magnetic stirrer, a high-speed disperser, or the like. be able to.

The physical properties of the recording ink of the present invention are not particularly limited and may be appropriately selected depending on the intended purpose. For example, the viscosity, surface tension and the like are preferably in the following ranges.
The viscosity of the recording ink at 25 ° C. is preferably 5 to 15 mPa · s. By setting the ink viscosity to 5 mPa · s or more, the effect of improving the printing density and the character quality can be obtained. On the other hand, by suppressing the ink viscosity to 15 mPa · s or less, it is possible to ensure the discharge performance.
Here, the said viscosity can be measured at 25 degreeC, for example using a viscometer (RL-500, the Toki Sangyo Co., Ltd. make).

  The surface tension of the recording ink is preferably 35 mN / m or less, more preferably 32 mN / m or less at 25 ° C. When the surface tension is 35 mN / m or less, ink leveling on the recording medium is improved.

  There is no restriction | limiting in particular as coloring of the recording ink of this invention, According to the objective, it can select suitably, Yellow, magenta, cyan, black etc. are mentioned. When recording is performed using an ink set in which two or more of these colorings are used in combination, a multicolor image can be formed. When recording is performed using an ink set in which all colors are combined, a full color image is formed. be able to.

  The recording ink of the present invention uses an piezoelectric head as a pressure generating means for pressurizing ink in an ink flow path as an ink jet head, and deforms a diaphragm that forms the wall surface of the ink flow path to increase the volume in the ink flow path. A so-called piezo type that discharges ink droplets by changing (refer to Japanese Patent Laid-Open No. 2-51734), or a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor. (Refer to Japanese Patent Application Laid-Open No. 61-59911), a diaphragm that forms the wall surface of an ink flow path and an electrode are arranged opposite to each other, and the diaphragm is deformed by an electrostatic force generated between the diaphragm and the electrode. Thus, any ink jet head such as an electrostatic type (see Japanese Patent Laid-Open No. 6-71882) for discharging ink droplets by changing the volume of the ink flow path is mounted. It is also good to use in the printer.

  The recording ink of the present invention can be suitably used in the field of ink jet recording ink and the like, but can be particularly suitably used in an image forming apparatus (printer or the like) using an ink jet recording method, for example, printing Alternatively, the recording paper and the recording ink may be heated at 50 to 200 ° C. before and after printing, and used for a printer having a function of promoting print fixing. The following ink media set, ink cartridge, The ink jet recording method, the ink jet recording apparatus, and the ink recording material can be particularly preferably used.

<Recording media>
As the recording medium, plain paper having no coating layer, and coated paper having a coating layer coated on at least one surface of the support are preferably used, and generally used as copy paper. Plain paper having a sizing degree of 10S or more and an air permeability of 5 to 50S is preferable.
In the case of coated paper, it has a support and a coating layer coated on at least one surface of the support, and at a contact time of 100 ms measured with a dynamic scanning absorptiometer. net transfer amount of said to the recording medium of water is 2~35ml / ^{m 2,} and coated paper transfer amount of said to the recording medium of pure water at the contacting time 400ms is 3~40ml / ^{m 2} is preferable.
If the transfer amount of the ink and pure water at the contact time of 100 ms is too small, beading is likely to occur. If it is too large, the ink dot diameter after recording becomes too smaller than the desired diameter. There is.
If the amount of transfer at the contact time of 400 ms is too small, the drying property is insufficient, and thus spur marks may be easily generated. If the amount is too large, the gloss of the image area after drying tends to be low. There is.
Here, the dynamic scanning absorptiometer (DSA, Papa-Pagi Technical Journal, Vol. 48, May 1994, pp. 88-92, Kuju Shigenori) absorbs liquid in a very short time. It is a device that can measure accurately. The dynamic scanning absorption meter reads the liquid absorption speed directly from the movement of the meniscus in the capillary, makes the sample a disk, and then scans the liquid absorption head in a spiral shape, and the scanning speed according to a preset pattern. Is automatically changed by a method in which the number of necessary points is measured with one sample. A liquid supply head for a paper sample is connected to a capillary via a Teflon (registered trademark) tube, and the position of the meniscus in the capillary is automatically read by an optical sensor. Specifically, the transfer amount of pure water was measured using a dynamic scanning absorption meter (K350 series D type, manufactured by Kyowa Seiko Co., Ltd.). The transfer amount at the contact time of 100 ms and the contact time of 400 ms can be obtained by interpolation from the measured value of the transfer amount at the contact time adjacent to each contact time.

<Image forming method>
The image forming method of the present embodiment includes an ink flying step of forming an image by applying a stimulus to the inkjet ink and causing the inkjet ink to fly on a recording medium.
In order to improve image quality such as image density, back-through, and bleeding, the medium may include a step of applying a treatment liquid before or after the ink is attached to the medium.

-Ink flying process and ink flying means-
The ink flying step is a step of forming an image on a recording medium by applying a stimulus (energy) to the recording ink of the present invention and causing the recording ink to fly.
The ink flying means is means for applying an stimulus (energy) to the recording ink of the present invention and causing the recording ink to fly to form an image on a recording medium. The ink flying means is not particularly limited, and examples thereof include various nozzles for ejecting ink.

  In the present invention, it is preferable that at least a part of the liquid chamber portion, the fluid resistance portion, the vibration plate, and the nozzle member of the inkjet head is formed of a material containing at least one of silicone and nickel.

  The nozzle diameter of the inkjet nozzle is preferably 30 μm or less, and more preferably 1 to 20 μm.

  The stimulus (energy) can be generated by, for example, the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose, and includes heat (temperature), pressure, vibration and For example, light. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, for example, a piezoelectric actuator such as a piezoelectric element, Examples include thermal actuators that use phase change due to liquid film boiling using electrothermal transducers such as heating resistors, shape memory alloy actuators that use metal phase changes due to temperature changes, electrostatic actuators that use electrostatic force, etc. It is done.

  There are no particular restrictions on the manner in which the recording ink flies, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, a recording signal is output to the recording ink in the recording head. Corresponding thermal energy is applied using, for example, a thermal head, bubbles are generated in the recording ink by the thermal energy, and the recording ink is formed into droplets from the nozzle holes of the recording head by the pressure of the bubbles. And a method of discharging and jetting. Further, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the recording head, the piezoelectric element bends and the volume of the pressure chamber is increased. And the recording ink is ejected and ejected as droplets from the nozzle holes of the recording head.

The size of the recording ink droplets to be ejected is preferably 3 × 10 ⁻¹⁵ to 40 × 10 ⁻¹⁵ m ³ ( ³ to 40 pL), for example. Is preferably 5 to 20 m / s, its driving frequency is preferably 1 kHz or more, and its resolution is preferably 300 dpi or more.

  The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

Here, one aspect of carrying out the ink jet recording method of the present invention using a serial type ink jet recording apparatus will be described with reference to the drawings.
The ink jet recording apparatus shown in FIG. 1 has an apparatus main body 101, a paper feed tray 102 for loading paper into the apparatus main body 101, and a sheet for forming (recording) an image formed (recorded) on the apparatus main body 101. A paper discharge tray 103 and an ink cartridge loading unit 104 are provided. On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 201.

  As shown in FIGS. 2 and 3, in the apparatus main body 101, the carriage 133 is slid in the main scanning direction by guide rods 131 and stays 132 which are horizontally mounted on left and right side plates (not shown). It is held movably and moved and scanned in the direction of the arrow in FIG. 3 by a main scanning motor (not shown).

  The carriage 133 includes a plurality of ink jet recording heads 134 including four ink jet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  As the ink jet recording head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator using phase change due to liquid film boiling using an electrothermal transducer such as a heating resistor, a metal phase due to temperature change, etc. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging ink can be used.

  In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The sub tank 135 is supplied with the recording ink of the present invention from the ink cartridge 201 of the present invention loaded in the ink cartridge loading section 104 via a recording ink supply tube (not shown).

  On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large coefficient of friction is provided facing the paper roller 143) and the paper feed roller 143, and the separation pad 144 is urged toward the paper feed roller 143 side.

  As a transport unit for transporting the paper 142 fed from the paper feed unit below the recording head 134, a transport belt 151 for transporting the paper 142 by electrostatic adsorption and a guide 145 from the paper feed unit. The counter roller 152 for transporting the paper 142 fed via the transport belt 151 with the transport belt 151 and the paper 142 fed substantially vertically upward are changed by approximately 90 ° so as to follow the transport belt 151. For this purpose, a conveyance guide 153 and a tip pressure roller 155 urged toward the conveyance belt 151 by a pressing member 154 are provided. In addition, a charging roller 156 that is a charging unit for charging the surface of the conveyance belt 151 is provided.

The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The transport belt 151 includes, for example, a surface layer serving as a sheet adsorption surface formed of a resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, a copolymer of tetrafluoroethylene and ethylene (ETFE), and the same surface layer. It has a back layer (medium resistance layer, earth layer) that has been subjected to resistance control with carbon as a material.
On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to a printing area by the recording head 134. Note that, as a paper discharge unit for discharging the paper 142 recorded by the recording head 134, a separation claw 171 for separating the paper 142 from the conveyance belt 151, a paper discharge roller 172, and a paper discharge roller 173 are provided. The paper discharge tray 103 is disposed below the paper discharge roller 172.

A double-sided paper feeding unit 181 is detachably mounted on the back surface of the apparatus main body 101.
The double-sided paper feeding unit 181 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 152 and the transport belt 151. A manual paper feed unit 182 is provided on the upper surface of the duplex paper feed unit 181.

  In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.

  At this time, the conveyance belt 157 is charged by the charging roller 156, and the sheet 142 is conveyed by being electrostatically attracted to the conveyance belt 151. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped paper 142 to record one line, and after the paper 142 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.

  When the recording ink remaining amount near end in the sub tank 135 is detected, a required amount of recording ink is supplied from the ink cartridge 201 to the sub tank 135.

  In this ink jet recording apparatus, when the recording ink in the ink cartridge 201 of the present invention is used up, the housing of the ink cartridge 201 can be disassembled and only the ink bag 241 inside can be replaced. Further, the ink cartridge 201 can supply recording ink stably even when the ink cartridge 201 is placed vertically and has a front loading configuration. Therefore, the ink cartridge 201 can be replaced even when the upper portion of the apparatus main body 101 is closed, for example, when stored in a rack, or when an object is placed on the upper surface of the apparatus main body 101. Can be easily performed.

  In addition, although it demonstrated in the example applied to the serial type (shuttle type) inkjet recording device which a carriage scans, it can apply similarly to the line type inkjet recording device provided with the line type head.

  Further, the ink jet recording apparatus and the ink jet recording method of the present invention can be applied to various types of recording by the ink jet recording method. It can be particularly preferably applied.

(Ink record)
The recorded matter recorded by the ink jet recording apparatus and the ink jet recording method of the present invention is the ink recorded matter of the present invention.
The ink recorded matter of the present invention has an image formed on the recording medium using the recording ink of the present invention.
The ink recorded matter of the present invention has an image formed on the recording medium of the ink media set of the present invention using the recording ink of the ink media set of the present invention.

-Support-
The support is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include paper based on wood fibers, and sheet-like materials such as non-woven fabrics mainly composed of wood fibers and synthetic fibers. .

  There is no restriction | limiting in particular as said paper, According to the objective, it can select suitably according to the objective, For example, wood pulp, waste paper pulp, etc. are used. Examples of the wood pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), NBSP, LBSP, GP, and TMP.

  As the raw material of the used paper pulp, the white paper, ruled white, cream white, card, special white, medium white, imitation, fair white, Kent, white, as shown in the used paper standard quality standard table of the used paper recycling promotion center Art, special upper limit, another upper limit, newspaper, magazine, etc. are mentioned. Specifically, printer paper such as non-coating computer paper, thermal paper, and pressure-sensitive paper as information-related paper; OA waste paper such as PPC paper; coating of art paper, coated paper, finely coated paper, matte paper, etc. Paper: High quality paper, color quality, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, reprint paper, super paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc. Examples of used paper and paperboard include chemical pulp paper and high-yield pulp-containing paper. These may be used individually by 1 type and may use 2 or more types together.

The waste paper pulp is generally produced from a combination of the following four steps.
(1) For disaggregation, waste paper is treated with mechanical force and chemicals with a pulper to loosen it into a fibrous form, and the printing ink is peeled off from the fiber.
(2) Dust removal is to remove foreign matter (plastic etc.) and dust contained in waste paper with a screen, cleaner or the like.
(3) In the deinking, the printing ink peeled off from the fiber using a surfactant is removed from the system by a flotation method or a cleaning method.
(4) Bleaching increases the whiteness of the fiber using an oxidizing action or a reducing action.
When mixing the used paper pulp, the mixing ratio of the used paper pulp in the total pulp is preferably 40% or less from the viewpoint of curling after recording.

  As the internal filler used for the support, for example, a conventionally known pigment is used as a white pigment. Examples of the white pigment include light calcium carbonate, heavy calcium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, White inorganic pigments such as calcium silicate, magnesium silicate, synthetic silica, aluminum hydroxide, alumina, lithopone, zeolite, magnesium carbonate, magnesium hydroxide; styrene plastic pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin And organic pigments such as melamine resin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the internally added sizing agent used for making the support include neutral rosin sizing agents used for neutral papermaking, alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), and petroleum resins. System sizing agents and the like. Among these, a neutral rosin sizing agent or alkenyl succinic anhydride is particularly preferable. The alkyl ketene dimer may be added in a small amount because of its high size effect, but the friction coefficient on the surface of the recording paper (media) is low and slippery, which is not preferable from the viewpoint of transportability during ink jet recording. There is.

There is no restriction | limiting in particular in the thickness of the said support body, Although it can select suitably according to the objective, 50-300 micrometers is preferable. The basis weight of the support, 45~290g / ^{m 2} is preferred.

-Coating layer-
The coating layer contains a pigment and a binder (binder), and further contains a surfactant and other components as necessary.
The ink recorded matter has high image quality, no bleeding, excellent temporal stability, and can be suitably used for various purposes as a material on which various prints or images are recorded.

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

[Synthesis and preparation of each raw material]
[Adjustment Example 1 (Surface-treated carbon black pigment dispersion)]
Each pigment dispersion was prepared as shown below.
In Adjustment Example 1, 90 g of carbon black having a CTAB specific surface area of 150 m ² / g and DBP oil absorption of 100 ml / 100 g was added to 3000 ml of 2.5 N normal sodium sulfate solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and 10 Oxidation treatment was performed by reacting for a period of time.
The reaction solution was filtered, and the carbon black separated by filtration was neutralized with a sodium hydroxide solution and subjected to ultrafiltration. The obtained carbon black was washed with water, dried, and dispersed in pure water so as to be 30% by weight.

[Adjustment Example 2 (surface treated yellow pigment dispersion)]
In Adjustment Example 2, C.I. I. Pigment Yellow 128 was subjected to low-temperature plasma treatment to prepare a pigment into which a carboxylic acid group was introduced. The dispersion in ion-exchanged water was desalted and concentrated with an ultrafiltration membrane to obtain a yellow pigment dispersion having a pigment concentration of 30%.

[Adjustment Example 3 (Preparation of surface-treated magenta pigment)]
According to the procedure of Preparation Example 2, a surface-modified magenta pigment was prepared. I. Instead of Pigment Yellow 128, Pigment Red 122 was used. Similar to the above example, the obtained surface-modified colored pigment is easily dispersed in an aqueous medium at the time of stirring, desalted and concentrated with an ultrafiltration membrane, and a magenta pigment dispersion having a pigment concentration of 30% by mass. did.

[Adjustment Example 4 (Adjustment of surface-treated cyan pigment)]
According to the procedure of Preparation Example 2, a surface-modified cyan pigment was prepared. I. Instead of CI Pigment Yellow 128, C.I. I. Pigment cyan 15: 3 was used. Similar to the above example, the obtained surface-modified colored pigment is easily dispersed in an aqueous medium upon stirring, desalted and concentrated with an ultrafiltration membrane, and a cyan pigment dispersion having a pigment concentration of 30% by mass. did.

[Synthesis Example 1 (Preparation of polymer dispersion)]
After sufficiently replacing the inside of the 1 L flask equipped with a mechanical stirrer, thermometer, nitrogen gas introduction tube, reflux tube and dropping funnel with nitrogen gas, 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of lauryl methacrylate, 4.0 g of polyethylene glycol methacrylate, 4.0 g of styrene macromer (manufactured by Toagosei Co., Ltd., trade name: AS-6) and 0.4 g of mercaptoethanol were charged, and the temperature was raised to 65 ° C. Next, styrene 100.8 g, acrylic acid 25.2 g, lauryl methacrylate 108.0 g, polyethylene glycol methacrylate 36.0 g, hydroxyethyl methacrylate 60.0 g, styrene macromer (manufactured by Toagosei Co., Ltd., trade name: AS-6) A mixed solution of 36.0 g, mercaptoethanol 3.6 g, azobisdimethylvaleronitrile 2.4 g and methyl ethyl ketone 18 g was dropped into the flask over 2.5 hours. After completion of dropping, a mixed solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of methyl ethyl ketone was dropped into the flask over 0.5 hours. After aging at 65 ° C. for 1 hour, 0.8 g of azobisdimethylvaleronitrile was added, and further aging was performed for 1 hour.
After completion of the reaction, 364 g of methyl ethyl ketone was added to the flask to obtain 800 g of a polymer solution having a concentration of 50% by mass.

[Preparation Example 5 (Preparation of phthalocyanine pigment-containing polymer fine particle dispersion)]
After 28 g of the polymer solution prepared in Synthesis Example 1, 26 g of phthalocyanine pigment, 13.6 g of 1 mol / L potassium hydroxide solution, 20 g of methyl ethyl ketone, and 30 g of ion-exchanged water were sufficiently stirred, they were kneaded using a three-roll mill. The obtained paste was put into 200 g of ion-exchanged water and stirred sufficiently, and then methyl ethyl ketone and water were distilled off using an evaporator to obtain a cyan polymer fine particle dispersion.

[Adjustment Example 6 (Preparation of dimethylquinacridone pigment-containing polymer fine particle dispersion)]
A magenta polymer fine particle dispersion was obtained in the same manner as in Synthesis Example 1 except that the phthalocyanine pigment of Synthesis Example 1 was changed to Pigment Red 122.

[Preparation Example 7 (Preparation of monoazo yellow pigment-containing polymer fine particle dispersion)]
A yellow polymer fine particle dispersion was obtained in the same manner as in Synthesis Example 1 except that the phthalocyanine pigment of Synthesis Example 1 was changed to Pigment Yellow 74.

[Adjustment Example 8 (Adjustment of carbon black pigment-containing polymer fine particle dispersion)]
A black polymer fine particle dispersion was obtained in the same manner as in Synthesis Example 1 except that the phthalocyanine pigment in Synthesis Example 1 was changed to carbon black.

[Example 1 to Example 18, Comparative Example 1 to Comparative Example 9]
Examples of ink production and ink production according to the present invention are shown in Table 1, Table 2, and Table 3 below, but the present invention is not limited thereto. The amount of each component described in the ink production example is based on mass.
An ink composition having the following formulation was prepared and adjusted with a 10% aqueous lithium hydroxide solution to a predetermined pH. Then, it filtered with the membrane filter with an average hole diameter of 0.8 micrometer, and obtained the ink composition of Example 1- Example 18 and Comparative Example 1- Comparative Example 9.

[Explanation of listed materials etc. in the table]
The abbreviations in the above table have the following meanings.
* Pigment dispersion (prepared above)
* Acrylic-silicone resin emulsion: manufactured by Showa Polymer Co., Ltd., Polysol ROY6312, solid content 40% by mass, average particle diameter 171 nm, minimum film-forming temperature (MFT) = 20 ° C.
* Polyurethane emulsion: manufactured by DIC, Hydran APX-101H, solid content 45% by mass, average particle size 160 nm, minimum film-forming temperature (MFT) = 20 ° C.
* Unidyne DSN403N: Perfluoroalkyl polyethylene oxide addition reaction product (manufactured by Daikin Industries, Ltd., component 99% by mass or more)
* Softanol EP-7025: polyoxyalkylene alkyl ether (manufactured by Nippon Shokubai Co., Ltd., component 100% by mass)
* NIKKOL ECTD-3NEX: Polyoxyethylene (3) sodium tridecyl ether acetate (manufactured by Nikko Chemical Co., Ltd., component 98 mass% or more)
* Proxel GXL: Antifungal agent based on 1,2-benzisothiazolin-3-one (Avicia, 20% by mass, containing dipropylene glycol)
* KM-72F: Self-emulsifying silicone defoaming agent (manufactured by Shin-Etsu Silicone Co., Ltd., 100% by mass)

The viscosity was measured at 25 ° C. using a viscometer (RL-500, manufactured by Toki Sangyo Co., Ltd.).
The pH was measured at 25 ° C. using a pH METER MODEL HM-30R type (manufactured by Toa DKK).

[Evaluation items, evaluation methods, evaluation criteria]
For recording, using an inkjet printer (IPSIO GXe5500, manufactured by Ricoh Co., Ltd.) in an environment adjusted to a temperature and humidity of 23 ° C. and 50% RH, the drive voltage of the piezo element is varied so that the amount of ink discharged is uniform. Settings were made so that the same amount of ink was attached to the media. The following “ejection stability” was evaluated under two conditions under an environment adjusted to a temperature and humidity of 23 ° C., 50% RH, a temperature and humidity of 10 ° C., and 15% RH.

<Storage stability>
The inks of Examples and Comparative Examples were allowed to stand in a 65 ° C. constant temperature bath for 4 weeks, and the viscosity change rate of the ink before and after being left in the constant temperature bath was measured.
○: Viscosity change less than 5% △: Viscosity change from 5% to less than 10%

<Curl evaluation>
When the “Square Solid” chart set at the limit of the printing range created by Microsoft Word 2000 is printed on the recording medium and placed on a flat surface with the printing surface facing back within 5 seconds after printing, the flatness of 4 The height from the surface was measured and judged according to the following evaluation criteria. The print mode was printed with the driver attached to the printer in the "plain paper-standard fast" mode and color matching off.
[Specify the color of the "filled square" part of word 2000]
Black: (R) 0, (G) 0, (B) 0
Yellow: (R) 255, (G) 255, (B) 0
Magenta: (R) 255, (G) 0, (B) 255
Cyan: (R) 0, (G) 0, (B) 255

〔Evaluation criteria〕
○: Less than 35 mm △: 35 mm or more and less than 50 mm x: 50 mm or more or rounded

<Offset>
As with image density, a chart is printed on a recording medium, and a polyethylene cylindrical roller with a diameter of 40 mm is applied to a “filled square” portion of 40 mm length on the printing surface within 5 seconds after printing. The portion where the ink was rolled while being pressed and the ink was retransferred from the cylindrical roller to the recording medium was measured by X-Rite 938, and judged according to the following evaluation criteria. The print mode was printed with “plain paper-standard clean” mode color matching off with a driver attached to the printer.

〔Evaluation criteria〕
○: Less than 0.1 Δ: 0.1 or more and less than 0.15,
×: 0.15 or more

<Fixability>
A chart with a 3cm x 3cm "filled square" solid image created by Microsoft Word 2000 is printed on a recording medium and dried at a temperature of 23 ± 1 ° C and a humidity of 50 ± 10% for 24 hours. JIS L 0803 cotton 3 attached to the CM-1 type clock meter with double-sided tape was reciprocated 5 times so as to touch the printing site, and then the ink adhesion stain on the cotton cloth was measured with X-Rite 938. The background color was subtracted, and the density of the soiled area was determined according to the following evaluation criteria.
[Specify the color of the "filled square" part of word 2000]
Black: (R) 0, (G) 0, (B) 0
Yellow: (R) 255, (G) 255, (B) 0
Magenta: (R) 255, (G) 0, (B) 255
Cyan: (R) 0, (G) 0, (B) 255

〔Evaluation criteria〕
○: Less than 0.05 Δ: 0.05 or more and less than 0.15 ×: 0.15 or more

<Discharge stability>
200 charts were continuously printed on MyPaper (manufactured by NBS Ricoh Co., Ltd.) to fill 5% area of A4 size paper per color created with Microsoft Word 2000 with a solid image. The printing mode used was a driver attached to the printer, in which the “plain paper-standard faster” mode was changed to “no color correction” than the user setting for plain paper.

〔Evaluation criteria〕
○: No discharge turbulence △: Some discharge turbulence ×: Some areas do not discharge

The evaluation results of each ink are simultaneously shown in Tables 1 to 3 for explaining the examples and comparative examples shown in the above ink production examples for the convenience of the reader.
From the above results, it is well understood that the present invention can provide an ink for ink jet recording and an ink set for ink jet recording which are excellent in offset property and curl characteristics and excellent in ejection stability.

101 apparatus main body 102 paper feed tray 103 paper discharge tray 104 ink cartridge loading unit 111 upper cover 112 front surface 115 front cover 131 guide rod 132 stay 133 carriage 134 recording head 135 sub tank 141 paper stacking unit 142 paper 144 separation pad 151 transport belt 152 again Counter roller 156 Charging roller 157 Conveying roller 158 Tension roller 171 Separating claw 172 Paper discharge roller 173 Paper discharge roller 181 Double-sided paper feed unit 201 Ink cartridge 241 Ink bag 242 Ink inlet 243 Ink outlet 244 Cartridge case

Japanese Patent Laid-Open No. 04-332775 Japanese Patent Laid-Open No. 06-157955 Japanese Patent Laid-Open No. 06-240189 JP 09-176538 A JP-A-10-130550 JP 2005-297549 A JP 2006-321876 A JP2012-40760 JP 2012-121287 A JP 2012-67178 A

Claims (7)

  Ink-jet ink containing at least water, a wetting agent, and a coloring material contains at least one vinyl ether group-containing ethylene glycol derivative of diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, or tetraethylene glycol monovinyl ether as a wetting agent. And an ink having a pH in the range of 6.5 to 7.5.   2. The ink according to claim 1, wherein the total content in the ink including the diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether is 20 to 50 mass%.   The ink according to claim 1 or 2, wherein the water content in the ink is 10 to 25% by mass.   And a nitrogen-containing hydrophilic organic solvent selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, β-methoxy-N, N-dimethylpropionamide, and 2-pyrrolidone, The ink according to any one of claims 1 to 3, wherein the content of the organic solvent is in the range of 5 to 30% by mass.   The ink according to any one of claims 1 to 4, wherein the colorant contains a self-dispersing pigment.   6. An ink jet recording apparatus comprising ink flying means for applying a stimulus to the ink jet ink according to claim 1 and causing the ink jet ink to fly to form an image on a recording medium.   An ink recorded matter comprising an image formed by the ink jet ink according to any one of claims 1 to 5 on a recording medium.

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