Ink ejection device and ink ejection method, method for manufacturing ink ejected material

Abstract

To provide an ink discharge device which can obtain an image having excellent wiping durability of a nozzle, high whiteness and excellent fastness, and has excellent ink discharge stability.SOLUTION: An ink discharge device has ink containing an organic solvent having an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin having a glass transition temperature (Tg) of 0°C or lower, and water, and ink discharge means which includes a nozzle plate having a water-repellent layer containing a silicone resin and discharges the ink, wherein the content of the organic solvent is 0.5 mass% or more and 2.5 mass% or less with respect to the ink, and the content of the white pigment is 6 mass% or more and 15 mass% or less with respect to the ink.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an ink ejection device and an ink ejection method, and a method for manufacturing ink ejected material. In the law To relate to. [Background technology]

[0002] Inkjet printers have advantages such as the ability to easily produce color prints on demand, and as a digital signal output device, they have become widely used in ordinary households. In recent years, there has been a growing demand for inkjet recording methods to achieve image quality comparable to conventional analog printing, not only for home use but also for slow-penetration media such as coated paper, non-absorbent media such as plastic films, and fabric media such as textiles and knitted fabrics. For example, in the textile printing field, the market size for so-called DTG (Direct to Garment), which involves printing directly onto clothing such as T-shirts, is expanding year by year. Furthermore, with the recent rise of personal recommendation businesses in the apparel industry and the increased activity of collaborations with fine art recognized in the interior textile field, the demand for inkjet recording systems capable of forming images with excellent color reproduction on fabrics is steadily increasing. In inkjet printing, which uses ink containing pigments as colorants to directly create images on fabric, the printing method differs from screen printing and other conventional printing methods in that it eliminates the need for plate making, storage, and cleaning, making it suitable for small-batch, high-mix production; it does not involve processes such as transfer printing, allowing for shorter lead times; and it has excellent lightfastness. Inks for this purpose have been developed.

[0003] In recent years, there has been a growing demand not only for plain fabrics, but also for fabrics that have already been colored through printing or other methods. One method for creating images on colored fabrics involves coating the fabric with white ink and then applying colored ink on top. Even on fabrics colored with dark colors such as black or navy, the layer of white ink acts as a base for the colored ink, allowing the colored ink to develop its full color. Therefore, in the above image creation method, it is important that the white ink conceals the dark color of the fabric and exhibits high whiteness on the fabric surface.

[0004] On the other hand, white ink in particular requires a high degree of whiteness to conceal the recording medium, and therefore contains many non-volatile components, which can lead to (1) uneven ink buildup due to ink adhering to the area around the nozzle holes that dispense the white ink, (2) the direction of the dispensed ink droplets becoming curved, variations in the size of the ink droplets occurring, and unstable flight speed of the ink droplets, and (3) discharge failure due to increased viscosity caused by the evaporation of volatile components of the ink. In response to this, a method has been proposed in which an ink-repellent layer (film) containing, for example, a fluorine-based compound, a compound having a perfluoropolyether chain and an alkoxysilane residue, or a silicone resin film is formed on the droplet-discharging surface of the nozzle (see, for example, Patent Documents 1 and 2).

[0005] In addition to forming an ink-repellent layer, it has become common practice for inkjet printers to incorporate a function to clean the liquid ejection surface of the nozzles. This cleaning function involves a series of actions, starting with ejecting a small amount of ink from each nozzle, followed by wiping the area around the nozzle hole with a rubber wiper or similar tool. This removes ink buildup and solidified substances around the nozzle hole, allowing for stable ink ejection. Furthermore, when using an inkjet printer for an extended period, it is preferable that the printer has high ejection performance (hereinafter referred to as wiping durability) even after repeated cleaning. For example, an inkjet recording apparatus has been proposed that includes an ink composition containing a pigment and a resin, a recording head having a plurality of nozzles, an absorption member that absorbs the ink composition adhering to the discharge ports of the nozzles and the nozzle forming surface, and a drive mechanism that relatively moves at least one of the absorption member and the recording head to perform a cleaning operation for removing the ink composition adhering to the nozzle forming surface by the absorption member (see, for example, Patent Document 3). Summary of the Invention Problems to be Solved by the Invention

[0006] An object of the present invention is to provide an ink ejection device that is excellent in wiping durability of nozzles, can obtain an image having a high whiteness and excellent fastness, and is excellent in ink ejection stability. Means for Solving the Problems

[0007] The ink ejection device of the present invention as means for solving the above problems is an ink containing an organic solvent having a SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin having a glass transition temperature (Tg) of 0°C or less, and water, and an ink ejection means having a nozzle plate having a liquid-repellent layer containing a silicone resin, for ejecting the ink. the content of the organic solvent is 0.5% by mass or more and 2.5% by mass or less with respect to the ink, and the content of the white pigment is 6% by mass or more and 15% by mass or less with respect to the ink. Advantages of the Invention

[0008] According to the present invention, it is possible to provide an ink ejection device that is excellent in wiping durability of nozzles, can obtain an image having a high whiteness and excellent fastness, and is excellent in ink ejection stability. Brief Description of the Drawings

[0009] [Figure 1] Figure 1 is a schematic diagram showing an example of an image forming apparatus having the ink ejection device of the present invention. [Figure 2] Figure 2 is a schematic diagram showing an example of a processing liquid container and an ink container. [Figure 3] Figure 3 is an exploded perspective view showing an example of a liquid dispensing head. [Figure 4] Figure 4 is a cross-sectional view of the liquid discharge head in Figure 3, taken from a III-III section perpendicular to the Y direction. [Figure 5] Figure 5 is a cross-sectional view showing an example of a piezoelectric element. [Figure 6] Figure 6 is an explanatory diagram showing an example of an enlarged cross-sectional view of the main part of the nozzle plate of a liquid discharge head. [Modes for carrying out the invention]

[0010] The following describes one embodiment of the present invention.

[0011] (Ink ejection device and ink ejection method) The ink ejection device of the present invention is An ink containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The device comprises a nozzle plate having a liquid-repellent layer containing a silicone resin, an ink dispensing means for dispensing the ink, an ink storage container, a processing liquid storage container, a processing liquid dispensing means, and, if necessary, other members and other means.

[0012] The ink ejection method of the present invention is The present invention includes an ink ejection step of ejecting the ink using the ink ejection device of the present invention, and further includes other steps as necessary. More specifically, the ink ejection method of the present invention is: The method includes an ink ejection step of ejecting an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water from an ink ejection means equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin, and further including a processing liquid application step and other steps as necessary.

[0013] In the ink ejection apparatus and ink ejection method of the present invention, the ink has an organic solvent content of 0.5% by mass or more and 2.5% by mass or less relative to the ink, and a white pigment content of 6% by mass or more and 15% by mass or less relative to the ink.

[0014] Traditionally, the following problems existed: When wiping was repeatedly performed during cleaning, the ink-repellent layer on the surface of the nozzle plate gradually wore away, impairing the function of the ink-repellent layer. As a result, ink accumulation was more likely to occur during the process of ejecting droplets from the nozzle in the above sequence, leading to nozzle failures and a deterioration of image quality. This problem is also largely related to the characteristics of the ink filled in the liquid ejection head, and is particularly pronounced with inks containing white pigment with large pigment particle sizes. This is because the white pigment in the ink between the ink-repellent layer and the wiper acts as an abrasive. In particular, the combination of a nozzle plate with a silicone resin ink-repellent film and ink containing white pigment significantly reduces wiping durability. Through diligent research, the inventors of this invention discovered the following problems with the prior art. Prior art disclosures describe that the method exhibits superior effects in at least one of the following: wipeability, cleaning ability, and liquid-repellent film preservation. The inventors of this invention have found that while this method can be effective with colored inks, the wiping durability is insufficient when using white pigment inks. Furthermore, the inventors considered reducing the amount of white pigment in the ink as one means of solving the problem related to wiping durability. However, this presented a problem: reducing the amount of white pigment resulted in insufficient whiteness being obtained in terms of image quality.

[0015] The inventors have found that by using an ink ejection means equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin, and an ink containing a polyurethane resin having a glass transition temperature (Tg) of 0°C or lower, an organic solvent with an SP value of 9.0 to 12.0 in an amount of 0.5% to 2.5% by mass, a white pigment in an amount of 6% to 15% by mass, and water, an image with high whiteness can be obtained and excellent wiping durability can be achieved. Furthermore, we found that this ink exhibits excellent ink ejection stability and image durability.

[0016] The ink ejection method of the present invention can be suitably carried out by the ink ejection apparatus of the present invention, the ink ejection step can be suitably carried out by the ink ejection means, and the other steps can be suitably carried out by other means.

[0017] <Ink container> The aforementioned ink container is a container that holds ink. The phrase "containing ink" means that ink is present in the container. The ink storage means is not particularly limited and includes, for example, a container for storing liquid compositions used in dispensing or coating methods. Examples of containers used in the aforementioned dispensing method include well-known ink cartridges and the like. Examples of containers used in the aforementioned coating method include containers for known liquid compositions used in methods such as blade coating, gravure coating, gravure offset coating, wire bar coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U-comma coating, AKKU coating, smoothing coating, microgravure coating, reverse roll coating, 4- to 5-roll coating, dip coating, curtain coating, slide coating, and die coating.

[0018] -ink- The ink contains an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water, wherein the content of the organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink, and the content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink, and further contains other components as necessary.

[0019] --Organic Solvents-- The aforementioned organic solvent includes an organic solvent having an SP value of 9.0 or more and 12.0 or less, and may further contain other organic solvents as needed.

[0020] The aforementioned "SP value" refers to the "solubility parameter," and is widely used as an indicator of affinity and solubility with materials such as solvents, resins, and pigments that are dissolved or dispersed in water or solvents. Various methods have been proposed for determining the SP value, including experimental measurement, calculation from physical properties such as immersion heat, and calculation from molecular structure. However, this invention uses the method proposed by Fedors, which calculates the SP value from molecular structure. This method is effective because it allows for the calculation of SP values ​​if the molecular structure is known, and the difference between these values ​​and experimentally measured values ​​is small. Fedors' method allows us to determine the SP value using equation (A) from the evaporation energy Δei and molar volume Δvi of each atom or group of atoms at 25°C. SP value = (ΣΔei / Δvi)1 / 2 ··· Equation (A)

[0021] In the present invention, based on the Fedors method, the SP value calculated from the molecular structure is used, and its unit is (cal / cm 3 ) 1 / 2 will be used. In the present invention, the SP value at 25°C is used, and no temperature conversion or the like is performed. The SP value can be calculated using the method of Fedors described in the literature "R.F. Fedors: Polym. Eng. Sci., 14〔2〕, 147-154".

[0022] The SP value of the organic solvent is 9.0 or more and 12.0 or less, preferably 9.0 or more and 10.6 or less. In the present invention, the content of the organic solvent having an SP value of 9.0 or more and 12.0 or less is 0.5% by mass or more and 2.5% by mass or less with respect to the ink, preferably 0.5% by mass or more and 2.0% by mass or less, and more preferably 0.5% by mass or more and 1.5% by mass or less. When the ink contains 0.5% by mass or more and 2.5% by mass or less of an organic solvent having an SP value of 9.0 or more, the whiteness of the obtained image can be increased. Further, when the ink contains 0.5% by mass or more and 2.5% by mass or less of an organic solvent having an SP value of 12.0 or less, excellent wiping durability can be obtained.

[0023] Examples of the organic solvent having an SP value of 9.0 or more and 12.0 or less include 3-ethyl-3-hydroxymethyloxetane (SP value = 11.3 (cal / cm 3 ) 1 / 2 ), β-methoxy-N,N-dimethylpropionamide (SP value = 9.2 (cal / cm 3 ) 1 / 2 [[ID=X]]), β-butoxy-N,N-dimethylpropionamide (SP value = 9.0 (cal / cm 3 ) 1 / 2 ), diethylene glycol monoethyl ether (SP value = 10.1 (cal / cm 3 ) 1 / 2), diethylene glycol monoisopropyl ether (SP value = 9.8 (cal / cm³) 3 ) 1 / 2 ), diethylene glycol monoisobutyl ether (SP value = 9.7 (cal / cm²) 3 ) 1 / 2 ), tripropylene glycol methyl ether (SP value = 9.8 (cal / cm³) 3 ) 1 / 2 ), 3-methyl-1,5-pentanediol (SP value = 11.8 (cal / cm³) 3 ) 1 / 2 ), polypropylene glycol 250 (SP value = 10.5 (cal / cm²) 3 ) 1 / 2 Number average molecular weight: 250), polypropylene glycol 400 (SP value = 9.8 (cal / cm³) 3 ) 1 / 2 (Number average molecular weight: 400), polypropylene glycol glyceryl ether (SP value = 10.3 (cal / cm³) 3 ) 1 / 2 ), polypropylene glycol monomethyl ether (SP value = 9.1 (cal / cm²) 3 ) 1 / 2 ), 2-ethyl-1,3-hexanediol (SP value = 10.6 (cal / cm²) 3 ) 1 / 2 Examples include the following. These may be used individually or in combination of two or more.

[0024] The organic solvent may contain 0.5% to 2.5% by mass of an organic solvent with an SP value of 9.0 to 12.0, as well as other organic solvents other than those with an SP value of 9.0 to 12.0. The aforementioned other organic solvents are not particularly limited and can be appropriately selected depending on the purpose, for example, water-soluble organic solvents. Examples of the water-soluble organic solvents include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Specific examples of the aforementioned water-soluble organic solvents include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,5- Polyhydric alcohols such as pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. Examples include polyhydric alcohol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate; and ethylene carbonate.

[0025] The aforementioned other organic solvents are not particularly limited and can be appropriately selected depending on the purpose.

[0026] --White Pigment-- There are no particular restrictions on the white pigment, and it can be appropriately selected depending on the purpose. For example, inorganic pigments or organic pigments can be used. These can be used individually or in combination of two or more. Mixed crystals may also be used. Examples of the inorganic pigments include titanium dioxide, iron oxide, calcium carbonate, barium sulfate, and aluminum hydroxide. Other white pigments that can be used include resin hollow particles and inorganic hollow particles. Specific examples of the aforementioned pigments include, for example, metals such as titanium dioxide and organic pigments.

[0027] To obtain ink by dispersing the white pigment, methods include introducing hydrophilic functional groups into the white pigment to make it a self-dispersible pigment, coating the surface of the white pigment with a resin and dispersing it, and using a dispersant to disperse it. One method for introducing hydrophilic functional groups into the aforementioned white pigment to create a self-dispersible pigment is to add functional groups such as sulfone groups or carboxyl groups to the white pigment, thereby making it dispersible in water. One method for coating and dispersing the surface of the white pigment with a resin is to encapsulate the white pigment in microcapsules so that it can be dispersed in water. This can be rephrased as resin-coated pigment. In this case, it is not necessary for all of the white pigment incorporated into the ink to be coated with resin; as long as the effects of the present invention are not impaired, uncoated white pigments or partially coated pigments may be dispersed in the ink. Methods for dispersion using the aforementioned dispersant include methods using known low-molecular-weight dispersants, such as surfactants, and high-molecular-weight dispersants. Depending on the white pigment, the dispersant can be, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. RT-100 (nonionic surfactant) manufactured by Takemoto Oil & Fat Co., Ltd., and sodium naphthalene sulfonate formalin condensate can also be suitably used as dispersants. The aforementioned dispersing agent may be used alone or in combination of two or more types.

[0028] [Pigment dispersion] It is possible to obtain ink by mixing the aforementioned white pigment with materials such as water or an organic solvent. Alternatively, it is also possible to manufacture ink by mixing the aforementioned white pigment with other materials such as water or a dispersant to form a pigment dispersion, and then mixing that dispersion with materials such as water or an organic solvent. The aforementioned pigment dispersion is obtained by mixing and dispersing water, pigment, pigment dispersant, and other components as needed, and adjusting the particle size. Dispersion is preferably performed using a disperser. There are no particular restrictions on the particle size of the pigment in the pigment dispersion, but in order to improve the dispersion stability of the white pigment and enhance image quality such as ejection stability and image density, it is preferable that the maximum frequency is between 20 nm and 500 nm, and more preferably between 20 nm and 150 nm, in terms of maximum number. The particle size of the pigment can be measured using a particle size analyzer (NanoTrac Wave-UT151, manufactured by MicroTrac-Bell Co., Ltd.). The pigment content in the pigment dispersion is preferably 6% to 15% by mass, and more preferably 8% to 11% by mass, relative to the ink in terms of solid content. A content of 6% by mass or more provides good whiteness, while a content of 15% by mass or less provides good discharge stability and wiping durability. The pigment dispersion is preferably filtered to remove coarse particles and degassed using a filter, centrifuge, or other means, as needed.

[0029] There are no particular restrictions on the particle size of the solids in the ink, and they can be appropriately selected depending on the purpose. However, from the standpoint of improving ejection stability and image quality such as image density, it is preferable that the maximum frequency in terms of maximum number is between 20 nm and 1,000 nm, and more preferably between 20 nm and 150 nm. The solids include resin particles, pigment particles, etc. The particle size can be measured using a particle size analyzer (NanoTrac Wave-UT151, manufactured by MicroTrac-Bell Co., Ltd.).

[0030] The physical properties of the ink can be appropriately selected depending on the purpose, and for example, viscosity, surface tension, pH, etc., are preferably within the following ranges. The viscosity of the ink at 25°C is preferably 5 mPa·s to 30 mPa·s, more preferably 5 mPa·s to 25 mPa·s, and even more preferably 8 mPa·s to 15 mPa·s, as this improves print density and character quality and ensures good ejection. Here, viscosity can be measured using, for example, a rotational viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.). Measurement conditions are 25°C, standard cone rotor (1°34'×R24), sample volume 1.2 mL, rotation speed 50 rpm, and measurement can be performed in 3 minutes. The surface tension of the ink is preferably 35 mN / m or less, and more preferably 32 mN / m or less, at 25°C, in order to ensure that the ink levels well on the recording medium and shorten the ink drying time. From the viewpoint of preventing corrosion of metal components in contact with the ink, the pH of the ink is preferably 7 to 12, and more preferably 8 to 11.

[0031] --Polyurethane resin-- The polyurethane resin is a polyurethane resin having a glass transition temperature (Tg) of 0°C or lower. The polyurethane resin is preferably a urethane resin emulsion (resin particles) that contains ester as its basic structure. By using a polyurethane resin emulsion containing esters as its basic structure and having a glass transition temperature (Tg) of 0°C or lower, images with excellent durability and texture can be obtained. In this invention, "durability" specifically refers to "wash fastness" as evaluated in accordance with JIS L0844. "Texture" refers to the flexibility of the resulting image. The aforementioned resin particles can be dispersed in water as a dispersion medium to form a resin emulsion, which can then be mixed with materials such as colorants and organic solvents to obtain ink. The resin particles may be synthesized as appropriate, or commercially available particles may be used. Furthermore, these may be used individually or in combination of two or more types of resin particles.

[0032] There are no particular restrictions on the volume-average particle size of the resin particles, and they can be appropriately selected depending on the purpose. However, from the standpoint of obtaining good adhesion and high image hardness, a particle size of 10 nm to 2,000 nm is preferred, 10 nm to 200 nm is more preferred, and 10 nm to 100 nm is particularly preferred. The volume-average particle size can be measured, for example, using a particle size analyzer (NanoTrac Wave-UT151, manufactured by MicroTrac-Bell Co., Ltd.).

[0033] There are no particular restrictions on the content of the polyurethane resin, and it can be appropriately selected depending on the purpose. However, from the viewpoint of robustness and storage stability of the ink, it is preferable that the content be 1% by mass or more and 30% by mass or less relative to the ink, and more preferably 5% by mass or more and 20% by mass or less.

[0034] --water-- The water content in the ink is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of the drying properties of the processing liquid, it is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 60% by mass or less.

[0035] --Other ingredients-- Other components can be the same as those used in the processing solution.

[0036] [Ink properties] There are no particular restrictions on the physical properties of the ink, and they can be appropriately selected according to the purpose. For example, it is preferable that the viscosity, surface tension, pH, etc., are within the following ranges. The viscosity of the ink at 25°C is preferably between 5 mPa·s and 30 mPa·s, and more preferably between 5 mPa·s and 25 mPa·s, as this improves print density and character quality and ensures good ejection. Here, viscosity can be measured using, for example, a rotational viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.). Measurement conditions are 25°C, standard cone rotor (1°34' × R24), sample volume of 1.2 mL, rotation speed of 50 rpm, and measurement can be performed in 3 minutes. The surface tension of the ink is preferably 35 mN / m or less, and more preferably 32 mN / m or less, at 25°C, in order to ensure that the ink levels well on the recording medium and shorten the ink drying time. From the viewpoint of preventing corrosion of metal components in contact with the ink, the pH of the ink is preferably 7 to 12, and more preferably 8 to 11. Qualitative and quantitative methods for organic solvents, resins, pigments, and other components contained in the ink include, for example, gas chromatography-mass spectrometry (GC-MS). For example, a GC-MS measuring device could be the GCMS-QP2020NX (manufactured by Shimadzu Corporation). The amount of water contained in ink can be measured by common methods such as quantitative analysis of volatile components by gas chromatography-mass spectrometry (GC-MS) or mass fluctuations by simultaneous thermogravimetric and differential thermal analysis (TG-DTA).

[0037] <Ink ejection means and ink ejection process> The ink ejection means is a means for ejecting the ink and comprising a nozzle plate having a liquid-repellent layer containing a silicone resin, and is a means for ejecting the ink contained in an ink storage container onto a recording medium. The ink ejection process is a process of ejecting the ink. The ink ejection means and the ink ejection process preferably apply the ink to the area on the recording medium from which the processing liquid described later has been ejected.

[0038] The ink ejection means in the ink ejection apparatus and ink ejection method of the present invention is equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin. The liquid-repellent layer may be a single-layer film or a multilayer structure consisting of two or more layers. There are no particular limitations on the method for forming the liquid-repellent layer containing the silicone resin on the nozzle plate, and an appropriate method can be selected depending on the purpose. For example, the method described in Japanese Patent Application Publication No. 2020-117683 can be cited. The average thickness of the liquid-repellent layer of the silicone resin is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.5 μm or more and 1.0 μm or less.

[0039] The ink ejection means is not particularly limited and can be appropriately selected depending on the purpose. Examples include liquid ejection heads as described in Japanese Patent No. 4936738 and Japanese Patent Application Publication No. 2020-117683.

[0040] (Liquid dispensing head) An example of the liquid dispensing head will be explained with reference to Figures 3 to 6. Note that the liquid dispensing head is not limited to those shown in Figures 3 to 6, as existing and known heads can be appropriately selected and used. Figure 3 is an exploded perspective view of the liquid discharge head 120, and Figure 4 is a cross-sectional view of the liquid discharge head 26 in Figure 3 when cut along a III-III section perpendicular to the Y direction. Figure 5 is a cross-sectional view of the piezoelectric element 44. As shown in Figures 2 and 3, the liquid discharge head 26 of this embodiment has a structure in which elements related to each nozzle N (example of the first nozzle) of the first nozzle row L1 and elements related to each nozzle N (example of the second nozzle) of the second nozzle row L2 are arranged symmetrically across a virtual plane O. That is, the structure of the liquid discharge head 26 is substantially the same in the positive side of the X direction (hereinafter referred to as the "first part") P1 and the negative side of the X direction (hereinafter referred to as the "second part") P2, with the virtual plane O in between. Multiple nozzles N of the first nozzle row L1 are formed in the first part P1, and multiple nozzles N of the second nozzle row L2 are formed in the second part P2. The virtual plane O corresponds to the interface between the first part P1 and the second part P2.

[0041] The liquid discharge head 26 comprises a first flow path member 30 and a second flow path member 48. The first flow channel member 30 is a structure that forms a flow channel for supplying ink to a plurality of nozzles N. The first flow channel member 30 and the second flow channel member 48 are stacked so as to overlap each other in the Z direction. The first flow channel member 30 is constructed by stacking a communication plate 32, a pressure chamber substrate 34, and a vibrating part 42. The communication plate 32, the pressure chamber substrate 34, and the vibrating part 42 are each long plate-shaped members in the Y direction.

[0042] As shown in Figure 3, the negative Z-direction surface of the first flow channel member 30 includes a first region A, which is laminated onto the second flow channel member 48 via a wiring board 45, and a second region B, which is laminated onto the second flow channel member 48 without the wiring board 45. The communication plate 32 is provided across these first region A and second region. For example, the pressure chamber substrate 34 and the vibrating part 42 shown in this figure are joined in this order to the negative Z-direction surface Fa (upper surface) of the communication plate 32 with an adhesive or the like, and are placed in the first region A.

[0043] On the surface Fa of the communication plate 32, in addition to the pressure chamber substrate 34 and the vibrating section 42, a plurality of piezoelectric elements 44, a wiring board 45, and a second flow channel member 48 are installed. The plurality of piezoelectric elements 44 and the wiring board 45 are installed on the negative side surface in the Z direction of the vibrating section 42 and are arranged in the first region A. The second flow channel member 48 is stacked on the first flow channel member 30 so as to overlap the first region A and the second region B, and is joined to the second region B of the surface Fa of the communication plate 32 with an adhesive or the like. Details of the specific arrangement of the multiple piezoelectric elements 44, the wiring board 45, etc. will be described later.

[0044] On the other hand, a nozzle plate 52 and a vibration absorber 54 are installed on the positive side of the communication plate 32 in the Z direction (i.e., the surface opposite to surface Fa), surface Fb. Each element of the liquid discharge head 26 is generally a plate-shaped member that is elongated in the Y direction, similar to the communication plate 32 and the pressure chamber substrate 34, and is joined together with adhesive or the like. Since the plate-shaped elements constituting the liquid discharge head 26 are stacked in the Z direction, which is perpendicular to the surface of each plate-shaped element, for example, the direction in which the communication plate 32 and the pressure chamber substrate 34 are stacked, and the direction in which the communication plate 32 and the nozzle plate 52 are stacked, correspond to the Z direction.

[0045] The nozzle plate 52 is a plate-shaped member on which multiple nozzles N are formed, and is joined to the surface Fb of the communication plate 32 with an adhesive or the like. The surface of the nozzle plate 52 opposite to the surface on the communication plate 32 side becomes the discharge surface 260 facing the medium 12. Each of the multiple nozzles N is a cylindrical through hole that penetrates from the discharge surface 260 to the surface on the communication plate 32 side. Multiple nozzles N constituting the first nozzle row L1 and multiple nozzles N constituting the second nozzle row L2 are formed on the nozzle plate 52. Specifically, the multiple nozzles N of the first nozzle row L1 are formed along the Y direction in the region on the positive side in the X direction when viewed from the virtual surface O of the nozzle plate 52, and the multiple nozzles N of the second nozzle row L2 are formed along the Y direction in the region on the negative side in the X direction. The nozzle plate 52 is a single plate-shaped member that is continuous across the portion on which the multiple nozzles N of the first nozzle row L1 are formed and the portion on which the multiple nozzles N of the second nozzle row L2 are formed. The nozzle plate 52 is manufactured by processing a single-crystal Si (silicon) substrate using semiconductor manufacturing technology (for example, processing technologies such as dry etching and wet etching). However, known materials and manufacturing methods can be applied to the production of the nozzle plate 52.

[0046] As shown in Figures 2 and 3, the communication plate 32 has a space Ra, a supply liquid chamber 60, a plurality of supply passages 61, and a plurality of connecting passages 63 formed in each of the first portion P1 and the second portion P2. The space Ra is an elongated opening formed along the Y direction in a plan view (i.e., viewed from the Z direction), and the supply passages 61 and connecting passages 63 are through holes formed for each nozzle N. The supply liquid chamber 60 is an elongated space formed along the Y direction across the plurality of nozzles N, and connects the space Ra and the plurality of supply passages 61 to each other. The plurality of connecting passages 63 are arranged in the Y direction in a plan view, and the plurality of supply passages 61 are arranged in the Y direction between the arrangement of the plurality of connecting passages 63 and the space Ra. The plurality of supply passages 61 communicate with the space Ra in common. In addition, any one connecting passage 63 overlaps with its corresponding nozzle N in a plan view. Specifically, any one communication passage 63 in the first section P1 communicates with one nozzle N in the first nozzle row L1 that corresponds to that one communication passage 63. Similarly, any one communication passage 63 in the second section P2 communicates with one nozzle N in the second nozzle row L2 that corresponds to that one communication passage 63.

[0047] The pressure chamber substrate 34 is a plate-shaped member in which a plurality of pressure chambers C (cavities) are formed in each of the first portion P1 and the second portion P2. The plurality of pressure chambers C are arranged in the Y direction. Each pressure chamber C is formed for each nozzle N and is an elongated space along the X direction in a plan view. The communication plate 32 and the pressure chamber substrate 34 are manufactured, like the nozzle plate 52 described above, by processing a silicon single crystal substrate using semiconductor manufacturing technology, for example. However, known materials and manufacturing methods can be arbitrarily used for the manufacture of the communication plate 32 and the pressure chamber substrate 34. As described above, the first flow path member 30 (communicating plate 32 and pressure chamber substrate 34) and the nozzle plate 52 include a substrate made of silicon. Therefore, by utilizing semiconductor manufacturing technology, as illustrated above, for example, fine channels can be formed in the first channel member 30 and the nozzle plate 52 with high precision.

[0048] A vibrating section 42 is installed on the surface of the pressure chamber substrate 34 opposite to the communication plate 32. The vibrating section 42 is a vibrating plate that is elastically capable of vibration. Furthermore, it is also possible to form the pressure chamber substrate 34 and the vibrating part 42 integrally by selectively removing a portion in the thickness direction of the region corresponding to the pressure chamber C from a plate-shaped member of a predetermined thickness. The vibrating part 42 can be composed of a single Si layer or a laminate of multiple layers including a Si layer. Examples of laminates of multiple layers including a Si layer include a laminate of a Si layer and an SiO2 layer, and a laminate of a Si layer, an SiO2 layer and a ZrO2 layer.

[0049] The surface Fa of the communication plate 32 and the vibrating part 42 are separated from each other and face each other inside each pressure chamber C. The pressure chamber C is a space located between the surface Fa of the communication plate 32 and the vibrating part 42, and generates a pressure change in the ink filled in this space. Each pressure chamber C is a space whose longitudinal direction is, for example, the X direction, and is formed individually for each nozzle N. For each of the first nozzle row L1 and the second nozzle row L2, multiple pressure chambers C are arranged in the Y direction. In the configurations shown in Figures 2 and 3, the end of any one pressure chamber C on the virtual plane O side overlaps with the communication passage 63 in a plan view, and the end opposite to the virtual plane O overlaps with the supply passage 61 in a plan view. Therefore, in each of the first section P1 and the second section P2, the pressure chamber C communicates with the nozzle N via the communication passage 63 and with space Ra via the supply passage 61. Alternatively, a predetermined flow resistance may be added by forming a throttled flow path with a narrowed flow path width in the pressure chamber C.

[0050] As shown in Figures 2 and 3, on the surface of the vibrating section 42 opposite to the pressure chamber C, a plurality of piezoelectric elements 44 corresponding to different nozzles N are installed for each of the first section P1 and the second section P2. The piezoelectric elements 44 are passive elements that deform in response to the supply of a drive signal. The plurality of piezoelectric elements 44 are arranged in the Y direction to correspond to each pressure chamber C. When the vibrating section 42 vibrates in conjunction with the deformation of the piezoelectric elements 44 supplied with a drive signal, the pressure in the pressure chamber C corresponding to that piezoelectric element 44 fluctuates, causing the ink filled in that pressure chamber C to pass through the communication passage 63 and the nozzle N and be ejected.

[0051] As shown in Figure 4, any single piezoelectric element 44 is a driving element consisting of a laminate in which a piezoelectric layer 443 is interposed between a first electrode 441 and a second electrode 442 that are facing each other. The portion where the first electrode 441, the second electrode 442, and the piezoelectric layer 443 overlap in a plan view functions as the piezoelectric element 44. Furthermore, it is also possible to define the part that deforms due to the supply of a drive signal (i.e., the active part that vibrates the vibrating part 42) as a piezoelectric element 44. It is possible to make one of the first electrode 441 and the second electrode 442 a continuous electrode (i.e., a common electrode) that spans multiple piezoelectric elements 44, and the other electrode a separate individual electrode for each of the multiple piezoelectric elements 44. In this embodiment, we illustrate the case where the first electrode 441 is a common electrode and the second electrode 442 is an individual electrode. The wiring structure for driving the piezoelectric element 44 will be described later.

[0052] The second flow channel member 48 shown in Figures 2 and 3 is a case member for storing ink supplied to multiple pressure chambers C (and furthermore, multiple nozzles N). The positive surface of the second flow channel member 48 in the Z direction is joined to the surface Fa of the communication plate 32 with an adhesive or the like. The second flow channel member 48 is formed from a different material than the first flow channel member 30. For example, the second flow channel member 48 can be manufactured by injection molding of a resin material.

[0053] As shown in Figure 3, the second flow channel member 48 has two elongated spaces Rb and Rc in the Y direction, respectively, in the first portion P1 and the second portion P2. Space Rc is longer in the Z direction than space Rb, and space Rb is longer in the X direction than space Rc. Space Rc extends from space Rb to space Ra of the communication plate 32, connecting space Rb and space Ra. The space composed of space Ra, space Rb, and space Rc is a circulation channel for circulating ink in multiple pressure chambers C, and functions as a common liquid chamber (reservoir) that supplies ink to multiple pressure chambers C.

[0054] In this embodiment, the space composed of space Ra, space Rb, and space Rc on the first portion P1 side is defined as the first circulation channel R1, and the space composed of space Ra, space Rb, and space Rc on the second portion P2 side is defined as the second circulation channel R2. The first circulation channel R1 is an inflow-side circulation channel that supplies ink to multiple pressure chambers C on the first section P1 side, and the second circulation channel R2 is an inflow-side circulation channel that supplies ink to multiple pressure chambers C on the second section P2 side.

[0055] The first circulation channel R1 is located on the positive side in the X direction when viewed from the virtual plane O, and the second circulation channel R2 is located on the negative side in the X direction when viewed from the virtual plane O. On the surface of the second flow channel member 48 opposite to the communication plate 32, a connection port 482 for introducing ink supplied from the liquid container 14 into the first circulation channel R1 and a connection port 482 for introducing ink supplied from the liquid container 14 into the second circulation channel R2 are formed. The ink in the first circulation channel R1 is supplied to the pressure chamber C on the first section P1 side via the supply liquid chamber 60 and each supply passage 61 on the first section P1 side. The ink in the second circulation channel R2 is supplied to the pressure chamber C on the second section P2 side via the supply liquid chamber 60 and each supply passage 61 on the second section P2 side.

[0056] Vibration absorbers 54 are installed on the surface Fb of the communication plate 32 for each of the first portion P1 and the second portion P2. The vibration absorbers 54 are made of a flexible film (compliance substrate). The vibration absorbers 54 of the first portion P1 absorb pressure fluctuations of the ink in the first circulation channel R1, and the vibration absorbers 54 of the second portion P2 absorb pressure fluctuations of the ink in the second circulation channel R2. As shown in Figure 3, the vibration absorbers 54 of the first portion P1 are installed on the surface Fb of the communication plate 32 so as to block the space Ra of the communication plate 32 and the multiple supply channels 61 of the communication plate 32 of the first portion P1, and constitute the wall surface (specifically the bottom surface) of the first circulation channel R1. The vibration absorbers 54 of the second portion P2 are installed on the surface Fb of the communication plate 32 so as to block the space Ra of the communication plate 32 and the multiple supply channels 61 of the communication plate 32 of the second portion P2, and constitute the wall surface (specifically the bottom surface) of the second circulation channel R2.

[0057] A circulating fluid chamber S is formed on the surface Fb of the communication plate 32 that faces the nozzle plate 52. The circulating fluid chamber S is a long, bottomed hole (groove) extending in the Y direction in a plan view. The opening of the circulating fluid chamber S is closed by a nozzle plate 52 joined to the surface Fb of the communication plate 32. The circulating fluid chamber S is part of the circulation flow path for circulating ink between the pressure chamber C of the first part P1 and the first circulation flow path R1, and between the second part P2 and the second circulation flow path R2. The circulating fluid chamber S functions as the outflow side circulation flow path through which ink flows out from the pressure chamber C of the first part P1 and the pressure chamber C of the second part P2. A connection port 482 communicating with the circulating fluid chamber S may be provided on the surface of the second flow path member 48 opposite to the communication plate 32, and ink from the circulating fluid chamber S may be guided out through the connection port 482.

[0058] Therefore, the nozzle plate 52, which is a nozzle-forming member in this liquid discharge head, will be further explained with reference to Figure 6. This nozzle plate 52 is formed by applying resin to the discharge surface of a nozzle base material 31, which is made of a Ni metal plate in which a nozzle hole 34 that will become the nozzle N is formed. In this way, a liquid-repellent layer 35 is formed on the nozzle plate 52. The resin that forms the liquid-repellent layer 35 is preferably a silicone resin. In this invention, the term "silicone resin" refers to a polymer whose main chain consists of siloxane bonds. Using a room-temperature curing liquid silicone resin as the silicone resin for forming the liquid-repellent layer 35 allows for application in the atmosphere. In particular, it is preferable to use a liquid silicone resin that exhibits hydrolytic activity.

[0059] Here, the nozzle substrate 31 is described as a Ni metal plate, but it is not limited to this. It can also be a resin material such as polyimide with nozzle holes drilled using an excimer laser, or a laminated material of metal and resin. Using a metal material as the nozzle substrate 31 provides a nozzle plate with high rigidity, while using a resin material improves adhesion with the liquid-repellent layer 35 and enhances durability.

[0060] The average thickness of the liquid-repellent layer 35 is preferably less than 10 μm, and more preferably between 0.1 μm and 1 μm, considering the effects on wiping durability, liquid repellency, and droplet discharge. Furthermore, good liquid repellency can be obtained by setting the surface roughness Ra (μm) of the liquid-repellent layer 35 to 0.2 μm or less.

[0061] A liquid ejection head in which the liquid-repellent layer 35 is made of silicone resin can achieve good liquid repellency against inks containing fluorine compounds. Liquid ejection heads made of fluorine resin have issues with liquid repellency against inks containing fluorine compounds, but by using a liquid-repellent layer of silicone resin, sufficient liquid repellency can be obtained even against inks containing fluorine compounds.

[0062] <Container for processing liquid> The aforementioned processing liquid container is a container that holds the processing liquid. "Containing the aforementioned processing liquid" means that the processing liquid is present in the container. The means for containing the processing liquid is not particularly limited, and examples include containers for liquid compositions used in dispensing methods, coating methods, etc. Examples of containers used in the aforementioned dispensing method include well-known ink cartridges and the like. Examples of containers used in the aforementioned coating method include containers for known liquid compositions used in methods such as blade coating, gravure coating, gravure offset coating, wire bar coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U-comma coating, AKKU coating, smoothing coating, microgravure coating, reverse roll coating, 4- to 5-roll coating, dip coating, curtain coating, slide coating, and die coating.

[0063] -Processing liquid- The aforementioned processing solution contains a polyvalent metal salt and water, and further, if necessary, contains additives such as organic solvents, resins, and other components. Furthermore, while the application of the processing solution is not particularly limited, it is preferable, for example, to be a liquid applied to the recording medium before an ink containing a colorant is applied to the recording medium.

[0064] --Polyvalent metal salts-- When the processing solution comes into contact with the ink, the polyvalent metal salt associates with the colorants in the ink through an electrostatic reaction, forming aggregates of the colorants, separating the colorants from the liquid phase, and promoting their fixation to the recording medium. By including the polyvalent metal salt in the processing solution, even when using a recording medium with large voids, the colorant can be retained on the recording medium by forming a layer of aggregates, thereby enabling the formation of images with high whiteness and high color development. Furthermore, even when using recording media with low ink absorption, beading can be suppressed, and high-quality images can be formed. Furthermore, unlike flocculants such as cationic polymers, the polyvalent metal salt can suppress the adhesion of the processing liquid to the recording medium even when the component comes into contact with the area of ​​the recording medium to which the processing liquid has been applied between the time the processing liquid is applied to the recording medium and the time the ink is ejected.

[0065] Examples of the polyvalent metal salts include salts of titanium compounds, chromium compounds, copper compounds, cobalt compounds, strontium compounds, barium compounds, iron compounds, aluminum compounds, calcium compounds, magnesium compounds, zinc compounds, and nickel compounds. One or more of these may be used in combination. Among these, salts of calcium compounds, magnesium compounds, and nickel compounds are preferred because they can effectively aggregate the pigments, and alkaline earth metal salts of calcium compounds and magnesium compounds are more preferred.

[0066] Examples of the aforementioned magnesium compounds include magnesium chloride, magnesium acetate, magnesium sulfate, magnesium nitrate, and magnesium silicate. Examples of calcium compounds include calcium carbonate, calcium nitrate, calcium chloride, calcium acetate, calcium sulfate, and calcium silicate. Examples of barium compounds include barium sulfate. Examples of zinc compounds include zinc sulfide and zinc carbonate. Examples of aluminum compounds include aluminum silicate and aluminum hydroxide. Among these, calcium chloride and calcium nitrate are preferred due to their solubility in water and their ability to effectively aggregate pigments. Furthermore, hydrates of these polyvalent metal salts can also be used as the aforementioned polyvalent metal salts.

[0067] --Organic Solvents-- There are no particular restrictions on the organic solvent used in the present invention, and it can be appropriately selected depending on the purpose. Examples include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds. Specific examples of water-soluble organic solvents include, for example, ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,4-pentanediol, and 1,5-pentanediol. Polyhydric alcohols such as pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl-1,3-pentanediol, petriol, ethylene glycol monoethyl ether, and ethylene glycol monobutyl ether. Examples include polyhydric alcohol alkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, and γ-butyrolactone; amides such as formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide; amines such as monoethanolamine, diethanolamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate; and ethylene carbonate.

[0068] The content of the organic solvent in the processing solution is not particularly limited and can be appropriately selected depending on the purpose.

[0069] --resin-- The resin contained in the processing liquid is not particularly limited and can be appropriately selected depending on the purpose. Examples include urethane resin, polyester resin, acrylic resin, vinyl acetate resin, styrene resin, butadiene resin, styrene-butadiene resin, vinyl chloride resin, acrylic styrene resin, and acrylic silicone resin. Resin particles made from these resins may also be used. The aforementioned resin particles can be dispersed in water as a dispersion medium to form a resin emulsion, which can then be mixed with materials such as colorants and organic solvents to obtain ink. The aforementioned resin particles may be synthesized as appropriate, or commercially available products may be used. Furthermore, these may be used individually or in combination of two or more types of resin particles.

[0070] There are no particular restrictions on the volume-average particle size of the resin particles, and they can be appropriately selected depending on the purpose. The volume-average particle size can be measured, for example, using a particle size analyzer (NanoTrac Wave-UT151, manufactured by MicroTrac-Bell Co., Ltd.).

[0071] There are no particular restrictions on the resin content in the processing solution, and it can be appropriately selected depending on the purpose.

[0072] --water-- The water content in the processing solution is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of the drying properties of the processing solution, 10% by mass or more and 90% by mass or less is preferred, and 20% by mass or more and 60% by mass or less is more preferred.

[0073] --Additives (Other Ingredients)-- The aforementioned treatment solution may contain, as needed, surfactants, defoamers, preservatives, fungicides, rust inhibitors, pH adjusters, and the like.

[0074] ---Surfactants--- Any of the following surfactants can be used: silicone-based surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants.

[0075] There are no particular limitations on the silicone-based surfactants, and they can be appropriately selected depending on the purpose. Among them, those that do not decompose even at high pH are preferred, and examples include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end modified polydimethylsiloxane. Those having a polyoxyethylene group or a polyoxyethylene polyoxypropylene group as a modifying group are particularly preferred because they exhibit good properties as aqueous surfactants. Furthermore, a polyether-modified silicone surfactant can also be used as the silicone surfactant. Examples include compounds in which a polyalkylene oxide structure is introduced into the Si side chain of dimethylsiloxane.

[0076] As the fluorine-based surfactants, perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains are particularly preferred because they have low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid and perfluoroalkyl sulfonate salts. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acids and perfluoroalkylcarboxylic acid salts. Examples of polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains include sulfate ester salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in their side chains, and salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in their side chains. Examples of counterions for the salts of these fluorinated surfactants include Li, Na, K, NH4, NH3CH2CH2OH, NH2(CH2CH2OH)2, and NH(CH2CH2OH)3.

[0077] Examples of the aforementioned amphoteric surfactants include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, and lauryldihydroxyethylbetaine.

[0078] Examples of the nonionic surfactants include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and ethylene oxide adducts of acetylene alcohols.

[0079] Examples of the anionic surfactants include polyoxyethylene alkyl ether acetate, dodecylbenzenesulfonate, lauryl salt, and salts of polyoxyethylene alkyl ether sulfate. These can be used individually or in combination of two or more types.

[0080] There are no particular limitations on the silicone-based surfactant, and it can be appropriately selected depending on the purpose. Examples include side-chain modified polydimethylsiloxane, both-end modified polydimethylsiloxane, one-end modified polydimethylsiloxane, and both-end modified polydimethylsiloxane. Polyether-modified silicone-based surfactants having a polyoxyethylene group or a polyoxyethylene-polyoxypropylene group as a modifying group are particularly preferred as they exhibit good properties as aqueous surfactants. Such surfactants may be synthesized as appropriate, or commercially available products may be used. Commercially available products include, for example, those from BIC Chemie Inc., Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Silicone Co., Ltd., Nippon Emulsion Co., Ltd., and Kyoeisha Chemical Co., Ltd. There are no particular limitations on the polyether-modified silicone surfactants mentioned above, and they can be appropriately selected depending on the purpose. For example, one example is a polyalkylene oxide structure represented by the general formula (S-1), in which a polyalkylene oxide structure is introduced into the Si side chain of dimethylpolysiloxane. TIFF0007852324000001.tif66151 General formula (S-1) (However, in general formula (S-1), m, n, a, and b each independently represent integers, R represents an alkylene group, and R' represents an alkyl group.) Commercially available polyether-modified silicone surfactants can be used, such as KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMALEX-SS-5602, SS-1906EX (Nippon Emulsion Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2162, FZ-2163, FZ-2164 (Toray Dow Corning Silicone Co., Ltd.), BYK-33, BYK-387 (BIC Chemie Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicone Co., Ltd.).

[0081] As the fluorine-based surfactant, compounds with 2 to 16 fluorine-substituted carbon atoms are preferred, and compounds with 4 to 16 fluorine-substituted carbon atoms are more preferred. Examples of fluorinated surfactants include perfluoroalkyl phosphate compounds, perfluoroalkyl ethylene oxide adducts, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains. Among these, polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in their side chains are preferred because they have low foaming properties, and fluorinated surfactants represented by general formulas (F-1) and (F-2) are particularly preferred. JPEG0007852324000002.jpg11116 General formula (F-1) In the compound represented by the above general formula (F-1), m is preferably an integer between 0 and 10, and n is preferably an integer between 0 and 40, in order to impart water solubility. General formula (F-2) C n F 2n+1- CH2CH(OH)CH2-O-(CH2CH2O) a -Y In the compound represented by the above general formula (F-2), Y is H or C m F 2m+1 m is an integer from 1 to 6, or CH2CH(OH)CH2-C m F 2m+1 m is an integer between 4 and 6, or CpH 2p+1 p is an integer between 1 and 19. n is an integer between 1 and 6. a is an integer between 4 and 14. Commercially available fluorine-based surfactants may be used as described above. Examples of commercially available products include Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Furlard 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 and Chemicals, Inc.); Zonyl TBS, FSP, FSA, FSN- Examples include the 100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemors); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by Neos Corporation); Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by Omnova); and Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.).

[0082] There are no particular restrictions on the amount of surfactant in the processing solution, and it can be appropriately selected depending on the purpose.

[0083] ---Antifoaming agent--- There are no particular limitations on the aforementioned defoaming agent; examples include silicone-based defoaming agents, polyether-based defoaming agents, and fatty acid ester-based defoaming agents. These may be used individually or in combination of two or more. Among these, silicone-based defoaming agents are preferred due to their superior foam-breaking effect.

[0084] ---Preservative and fungicidal agent--- There are no particular restrictions on the aforementioned preservative and antifungal agent; for example, 1,2-benzisothiazolin-3-one is one such example.

[0085] ---Rust Inhibitor--- There are no particular restrictions on the rust inhibitor, and examples include acidic sulfites and sodium thiosulfate.

[0086] ---pH adjuster--- The pH adjusting agent is not particularly limited as long as it can adjust the pH to 7 or higher, and examples include amines such as diethanolamine and triethanolamine.

[0087] <Means for applying processing solution and process for applying processing solution> The processing liquid application means is a means for applying the processing liquid contained in the processing liquid container to the recording medium. The processing liquid application step is a step of applying the processing liquid contained in the processing liquid container to the recording medium.

[0088] There are no particular restrictions on the processing liquid application step, and it can be appropriately selected according to the purpose, for example, a dispensing method or a coating method. There are no particular restrictions on the discharge method, and it can be appropriately selected according to the purpose. Examples include a method using a piezoelectric element actuator, a method applying thermal energy, a method using an actuator utilizing electrostatic force, and a method using a continuous-jet type charged control head. Examples of the coating methods include the blade coating method, gravure coating method, gravure offset coating method, wire bar coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma coating method, AKKU coating method, smoothing coating method, microgravure coating method, reverse roll coating method, 4- or 5-roll coating method, dip coating method, curtain coating method, slide coating method, and die coating method.

[0089] In the processing solution application step, the amount of processing solution applied to the recording medium is 10 mg / cm³. 2 More than 50mg / cm 2 The following is preferred: 20 mg / cm³ 2 More than 40mg / cm 2 The following is more preferable: The amount administered is 10 mg / cm³. 2 If the above is achieved, image quality can be improved, and 50 mg / cm² 2The following conditions can suppress the phenomenon of solid components in the treatment solution precipitation and causing uneven coloration.

[0090] [Recording medium] There are no particular restrictions on the recording medium, and it can be appropriately selected according to the purpose. For example, cloth can be used. If the recording medium is cloth, then fabrics such as those used for clothing like T-shirts, textiles, leather, etc., can be used as appropriate. Note that recording media, media, and printed material are all synonymous.

[0091] <Other means and other processes> The aforementioned other means are not particularly limited and can be appropriately selected depending on the purpose, and examples include post-processing means, a first drying means, a second drying means, etc. The aforementioned other steps are not particularly limited and can be appropriately selected depending on the purpose. Examples include post-processing steps, a first drying step, and a second drying step.

[0092] <<Post-processing means and post-processing steps>> The aforementioned post-treatment means is a means for applying a post-treatment solution. The aforementioned post-treatment step is the step of applying a post-treatment solution. The post-treatment solution is not particularly limited, as long as it can form a transparent layer. The aforementioned post-treatment liquid is obtained by selecting and mixing organic solvents, water, resins, surfactants, defoamers, pH adjusters, anti-corrosion and anti-fungal agents, rust inhibitors, etc., as needed. Furthermore, the post-processing solution may be applied to the entire recording area formed on the recording medium, or it may be applied only to the area where the ink image is formed. There are no particular restrictions on the method of applying the post-treatment liquid, and the same method as the method of applying the treatment liquid can be used.

[0093] <<First drying means and first drying process>> The first drying means is a means for drying the recording medium to which the processing liquid has been applied. The first drying step is a step of drying the recording medium to which the processing liquid has been applied. The process may include a step of drying the recording medium to which the processing liquid has been applied (also referred to as the first drying step) after the processing liquid application step. By performing the first drying step described above, the processing liquid applied to the recording medium is dried. The first drying means and drying process are not particularly limited as long as they can dry the recording medium, but a heating process is preferred. The heating temperature in the first drying step is preferably 60°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher.

[0094] The first drying method is not particularly limited and can be appropriately selected from known heating methods. Examples of drying methods that use heating include roll heaters, drum heaters, hot air generators, and heat presses.

[0095] <<Second drying means and second drying process>> The second drying means is a drying means that dries the recording medium to which the processing liquid and the ink have been applied after the ink ejection process. The second drying step is a step of drying the processing liquid and the recording medium coated with the ink after the ink ejection step. The processing liquid and ink applied to the recording medium by the second drying step are dried. The second drying means and drying step are not particularly limited as long as they can dry the recording medium, but a heating step is preferred. The heating temperature in the second drying step is preferably 60°C or higher, more preferably 80°C or higher, and even more preferably 100°C or higher.

[0096] The second drying means is not particularly limited and can be appropriately selected from known drying means, such as a roll heater, drum heater, hot air generator, or heat press.

[0097] The ink ejection device of the present invention can be suitably used in various recording devices using an inkjet recording method, such as printers, facsimile machines, copying machines, printer / fax / copier combination machines, and 3D modeling devices. In the present invention, an ink ejection device and an ink ejection method refer to a device capable of ejecting ink or various processing liquids onto a recording medium, and a method of recording using such a device. A recording medium refers to a material to which ink or various processing liquids can be applied, even temporarily. Furthermore, this recording device includes desktop ink ejection devices and wide-format ink ejection devices capable of printing on A0-sized recording media, such as continuous-form printers that can use continuous paper wound in a roll as a recording medium.

[0098] Figure 1 shows an example of an image forming apparatus having the ink ejection device of the present invention. Furthermore, the ink ejection step and the processing liquid application step in the ink ejection method of the present invention may be performed using the same printing equipment, or they may be performed using separate printing equipment.

[0099] The image forming apparatus 100 in Figure 1 includes a pre-treatment liquid application unit 110, an ink ejection unit 120, a post-treatment liquid application unit 130, a drying unit 140, and a transport unit 150. The pre-treatment liquid application unit 110 applies the pre-treatment liquid to the recording medium M. The pre-treatment liquid application unit 110, post-treatment liquid application unit 130, drying unit 140, and conveying unit 150 may be omitted if necessary.

[0100] Methods for applying the pretreatment solution are not limited to any particular type, but include inkjet, roller coating, blade coating, gravure coating, gravure offset coating, bar coating, roll coating, knife coating, air knife coating, comma coating, U-comma coating, AKKU coating, smoothing coating, microgravure coating, reverse roll coating, 4- to 5-roll coating, dip coating, curtain coating, slide coating, and die coating. Furthermore, since the pretreatment solution may be applied to the recording medium manually using a bar coating method or the like before printing using an image forming apparatus, the pretreatment solution application unit 110 may be omitted.

[0101] The recording medium M used for recording is not particularly limited, but for example, plain paper, glossy paper, special Examples include special paper, corrugated cardboard, cloth, film, OHP sheets, and general-purpose printing paper.

[0102] The ink ejection unit 120 ejects inkjet ink onto the surface of the recording medium M to which the pretreatment solution has been applied. For example, a known inkjet head can be used as the ink ejection unit 120. The ink ejection unit 120 may be a head that ejects ink of any color, and for example, it may be provided with heads that eject ink of the following colors as needed: Y (yellow), M (magenta), C (cyan), K (black), and W (white).

[0103] The post-processing liquid application unit 130 only needs to be able to apply the post-processing liquid to the ink-ink-applied area on the surface of the recording medium M where the inkjet ink has been applied. For example, in addition to an inkjet head, a spray or roller can be used. The post-treatment liquid application unit 130 may be omitted.

[0104] There are no particular limitations on the method of applying the post-treatment solution, but examples include inkjet method, roller coating method, blade coating method, gravure coating method, gravure offset coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma coating method, AKKU coating method, smoothing coating method, microgravure coating method, reverse roll coating method, 4- to 5-roll coating method, dip coating method, curtain coating method, slide coating method, and die coating method.

[0105] The drying unit 140 dries the recording medium M to which the post-treatment liquid has been applied using hot air. If there is no post-treatment liquid application unit, the drying unit 140 may be omitted. The drying unit 140 may use infrared rays, microwaves, a roll heater, or the like instead of hot air to heat and dry the recording medium M to which the post-treatment liquid has been applied, or the recording medium M to which the post-treatment liquid has been applied may be air-dried without operating the drying unit 140.

[0106] The transport unit 150 transports the recording medium M. The transport unit 150 is not particularly limited as long as it is capable of transporting the recording medium M. Examples include conveyor belts and platens.

[0107] The image forming apparatus 100 may further include a fixing unit for heating and fixing the image formed on the recording medium M. The fixing unit is not particularly limited, but examples include fixing rollers.

[0108] Figure 2 is a schematic diagram showing an example of a processing liquid container and an ink container. The containment container 411 is housed, for example, in a plastic containment container case 414. Thus, each containment container 410 is used as a cartridge. The discharge port 413 of each containment container 410 communicates with an inkjet ejection head, enabling the inkjet ejection head to eject processing liquid and white ink onto the recording medium.

[0109] (Method for manufacturing ink ejected material and apparatus for manufacturing ink ejected material) The present invention provides a method for producing ink ejected material, comprising a process of applying a processing solution containing a polyvalent metal salt and water, The invention includes an ink ejection step of ejecting an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water from an ink ejection means equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin, and further including other steps as necessary. The present invention relates to an ink ejection method and includes an ink ejection apparatus, which provides a processing solution containing a polyvalent metal salt and water, The device comprises a nozzle plate having a liquid-repellent layer containing a silicone resin, and an ink dispensing means for dispensing an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water, and further includes other processes as necessary.

[0110] In this specification, the term "ink ejected material" includes ink and a recording medium, and refers to the material obtained when ink is ejected onto the recording medium, or the material obtained when it is dried.

[0111] In the method for producing ink ejected material and the apparatus for producing ink ejected material of the present invention, the ink has an organic solvent content of 0.5% by mass or more and 2.5% by mass or less relative to the ink, and a white pigment content of 6% by mass or more and 15% by mass or less relative to the ink.

[0112] The common elements described in the ink ejection method and ink ejection apparatus of the present invention can also be appropriately selected in the method for manufacturing ink ejected material and the apparatus for manufacturing ink ejected material of the present invention.

[0113] (White ink) The present invention provides a white ink containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink, and other components are also included as needed. The common elements described in the ink ejection method and ink ejection apparatus of the present invention can also be appropriately selected for the white ink of the present invention.

[0114] (Processing solution and ink set) The present invention provides a set of processing solution and ink, comprising a processing solution containing a polyvalent metal salt and water, A set of inks containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink, and other components are also included as needed. The common elements described in the ink ejection method and ink ejection apparatus of the present invention can also be appropriately selected in the set of processing liquid and ink of the present invention. [Examples]

[0115] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments. Hereinafter, "parts" means "parts by mass" and "%" means "percent mass".

[0116] <Preparation of the treatment solution> [Examples of preparation of processing solutions 1-3] Treatment solutions 1 to 3 were prepared by mixing and stirring the materials of the formulations shown in Table 1. In Table 1, the salt content is shown in parts by mass including hydration water, and the resin particle content is shown in parts by mass of solids.

[0117] [Table 1]

[0118] The details of each material shown in Table 1 (product name, manufacturer name, etc.) are as follows:

[0119] -Organic Solvents- Glycerin (manufactured by Tokyo Chemical Industry Co., Ltd.) -salt- • Calcium chloride dihydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) • Calcium nitrate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) • Ammonium lactate solution (40% concentration, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) - Surfactants - • BYK-348 (manufactured by Big Chemie Co., Ltd.) -Resin particles- • Ethylene-vinyl acetate-vinyl chloride copolymer resin emulsion (product name: Sumikaflex 850HQ, solid content concentration: 50% by mass, manufactured by Sumika Chemtex Co., Ltd.)

[0120] <Preparation of white ink> -Preparation of urethane resin emulsion A- The following formulation was charged into a 2L reactor equipped with a stirrer, thermometer, nitrogen sealing tube, and condenser, and mixed uniformly at 60°C. [Prescription] Methyl ethyl ketone: 100 parts by mass • Polyester polyol (polyester polyol obtained from isophthalic acid / adipic acid = 6 / 4 (molar ratio) and ethylene glycol / neopentyl glycol = 1 / 9 (molar ratio): number average molecular weight = 2,000, average number of functional groups = 2): 345 parts by mass • 2,2-Dimethylolpropionic acid (DMPA): 9.92 parts by mass

[0121] Subsequently, 45.1 parts by mass of triethylene glycol diisocyanate (TEGDI) and 0.08 parts by mass of dioctyltin dilaurate (DOTDL) were added to this mixture, and the mixture was reacted at 72°C for 3 hours to obtain a polyurethane solution. To this polyurethane solution, 80 parts by mass of isopropyl alcohol (IPA), 220 parts by mass of methyl ethyl ketone (MEK), 3.74 parts by mass of triethanolamine (TEA), and 596 parts by mass of water were charged and the mixture was inverted. Subsequently, MEK and IPA were removed using a rotary evaporator (manufactured by Tokyo Rikakikai Co., Ltd.) to obtain polyurethane resin emulsion A. After the obtained polyurethane resin emulsion A was cooled to room temperature, deionized water and sodium hydroxide aqueous solution were added to adjust the solid content to 50% by mass and the pH to 8. The glass transition temperature (Tg) of the obtained polyurethane resin emulsion A, measured using "Thermo plus EVO2" (manufactured by Rigaku Corporation), was -5°C.

[0122] <Preparation of Urethane Resin Emulsion B> (1) 1 mole of 1,6-hexanediol, (2) 1.4 moles of dicyclohexylmethane diisocyanate, (3) 1 mole of isocyanurate trimer of 1,6-hexamethylene diisocyanate, (4) 0.1 moles of a diisocyanate compound obtained by reacting 1 / 3 mole of polyethylene glycol monomethyl ether with a molecular weight of 1,000 with (4) 1 mole of N-methyl-2-pyrrolidone by 15 moles of the total mass were charged into a reaction flask and reacted at 90°C for 2 hours under a nitrogen stream to obtain a prepolymer composition. 0.2 g of silicone-based defoaming agent SE-21 (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) was dissolved in 600 g of water. 450 g of the prepolymer composition with a solid content of 85% obtained above was added dropwise over 15 minutes, and after stirring at 25°C for 10 minutes, the compound of formula (A) below, ethylenediamine, and adipic acid hydrazide were added dropwise to obtain polyurethane resin emulsion B. [ka] The glass transition temperature (Tg) of polyurethane resin emulsion B was measured using a DSC (Rigaku Corporation, Thermo plus EVO2 / DSC) and found to be 20°C.

[0123] -Preparation of white pigment dispersion (titanium dioxide pigment dispersion)- In a beaker, 37.5 parts by mass of acrylic copolymer (DISPERBYK-2008: manufactured by BYK, solid content concentration: 60% by mass) was dissolved in 20.0 parts by mass of high-purity water. 30.0 parts by mass of titanium dioxide (JR-600A: manufactured by Teika (primary particle size: 250 nm, surface treatment: Al)) was added, and the mixture was stirred at 5,000 rpm for 30 minutes using an Excel autohomogenizer (manufactured by Nippon Seiki Seisakusho Co., Ltd.) until it was dispersed without clumps. The rotation speed was then gradually increased to 10,000 rpm for 30 minutes. The obtained titanium dioxide pigment dispersion was treated with an ultrasonic homogenizer US-300T (manufactured by Nippon Seiki Seisakusho Co., Ltd., tip φ26) at 200 μA for 1 hour while being cooled with water, and then filtered through a 5 μm membrane filter (cellulose acetate membrane) to obtain a white pigment dispersion with a solid content concentration of 34.3% by mass of titanium dioxide pigment.

[0124] [Examples of adjustments for white inks 1-16] A vehicle was prepared by dissolving the materials of the formulations listed in Tables 2 to 6, excluding the white pigment dispersion and urethane resin emulsion, in deionized water (adjusted so that the total ink volume ultimately equals 100%). Next, the mixture was mixed with the urethane resin emulsion, and finally with the white pigment dispersion. The mixture was then filtered through a filter with an average pore size of 0.8 μm to obtain white inks 1 to 16.

[0125] The details of each material shown in Tables 2 to 6 (product name, manufacturer name, etc.) are as follows:

[0126] -Organic Solvents- • Glycerin (SP value: 16.4, manufactured by Tokyo Chemical Industry Co., Ltd.) • 3-Methyl-1,3-butanediol (SP value: 12.1, manufactured by Tokyo Chemical Industry Co., Ltd.) • 3-Ethyl-3-hydroxylmethyloxetane (SP value: 11.3, manufactured by Tokyo Chemical Industry Co., Ltd.) • 2-Ethyl-1,3-Hexanediol (SP value: 10.6, manufactured by Tokyo Chemical Industry Co., Ltd.) • β-methoxy-N,N-dimethylpropionamide (SP value: 9.2, manufactured by Tokyo Chemical Industry Co., Ltd.) • Triethylene glycol butyl methyl ether (SP value: 8.4, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0127] -resin- • Acrylic resin emulsion (Product name: Boncoat CF-6140, Tg: 12℃, manufactured by DIC Corporation)

[0128] - Surfactants - • BYK348 (manufactured by Big Chemie Co., Ltd., silicone-based surfactant) • FS300 (manufactured by Dupont, a fluorine-based surfactant)

[0129] - Additives (preservatives and fungicides) - • Proxel LV (manufactured by Arch Chemicals Japan)

[0130] [Table 2]

[0131] [Table 3]

[0132] [Table 4]

[0133] [Table 5]

[0134] [Table 6]

[0135] Next, the obtained processing solution and white ink were used to evaluate "wiping durability," "whiteness," "selective fastness," "dispensing stability," and "texture" as follows. The results are shown in Tables 7 and 8 below.

[0136] <Wiping durability> Inks 1-21 were loaded into an inkjet printer (device name: IPSiO GXe5500, manufactured by Ricoh Co., Ltd.), and a cleaning sequence was performed. For the nozzle plates used, nozzle plates with an average silicone layer thickness of 0.5 μm to 1.0 μm were fabricated and used. Subsequently, a nozzle check pattern was printed, and the number of cleaning sequences required when the number of non-dispensing nozzles exceeded 10 was measured. Wiping durability was then evaluated according to the following evaluation criteria. In practical use, an evaluation of A or B is desirable. "Cleaning" refers to the operation of wiping the inkjet nozzle and its surrounding area with a wiper after a small amount of ink has been discharged from the inkjet nozzle, and is a function installed in the aforementioned printer. [Evaluation Criteria] A: The cleaning sequence has run more than 3,000 times. B: Cleaning sequence count is between 2,000 and 3,000 C: Cleaning sequence count is less than 2,000 times

[0137] <Whiteness> The prepared processing solutions 1-3 were filled into a high-speed garment inkjet printer (device name: RICOH Ri 2000, manufactured by Ricoh Co., Ltd.), and the amount of processing solution applied was 20 mg / cm². 2 After adjusting the settings, a solid color image was printed (recorded) onto a thin, dark-colored cotton fabric (product name: Heavyweight T-shirt Black, manufactured by Toms Co., Ltd.) with a resolution of 600 dpi x 1,200 dpi, covering an area of ​​27 cm vertically and 23 cm horizontally. It was then dried at 165°C for 60 seconds. Next, the prepared inks 1-21 were loaded into a high-speed garment printer (device name: RICOH Ri 2000, manufactured by Ricoh Co., Ltd.), and the ink adhesion amount was 20 mg / cm². 2After adjusting the settings, a solid color image was printed (recorded) onto the printed area of ​​the processing solution, with a resolution of 600 dpi x 1200 dpi and a size of 10 cm x 10 cm. The area was then dried at 165°C for 90 seconds to obtain image samples 1-16. Next, the brightness (L) of the solid image portion of the obtained image sample was measured using a spectrophotometer (device name: X-rite eXact, manufactured by X-Rite Corporation). * The whiteness (color development) was measured and evaluated based on the following evaluation criteria. It is desirable for the evaluation to be A or B in practical use. [Evaluation Criteria] A:L * 75 or higher B:L * 65 or more but less than 75 C:L * less than 65

[0138] <Washfastness> Based on JIS L0844, each image sample was washed 10 times using a fully automatic washing machine (model ASW-45A1, manufactured by Sanyo Electric Co., Ltd.). The degree of fading was visually confirmed using a colorfastness grayscale, and "wash fastness" was evaluated based on the following evaluation criteria. [Evaluation Criteria] A: Level 4 or above B: Grade 3 or higher, but less than Grade 4 C: Below Grade 3

[0139] <Texture> The image samples were touched by hand and evaluated based on the following evaluation criteria. [Evaluation Criteria] A: It has a soft texture. B: Slightly stiff to the touch C: It has a hard texture.

[0140] <Discharge stability> Inks 1-21 were loaded into a high-speed garment inkjet printer (device name: RICOH Ri 2000, manufactured by Ricoh Co., Ltd.). A solid white image with a resolution of 600 x 1,200 dpi and dimensions of 297 mm (height) x 420 mm (width) was printed, and a nozzle check pattern was then printed. The number of nozzles that failed to eject ink was measured. The ejection stability was evaluated based on the following evaluation criteria. An evaluation of A or B is desirable for practical use. [Evaluation Criteria] A: The number of non-discharging nozzles is 0 or more but less than 3. B: The number of non-discharging nozzles is 3 or more but less than 10. C: The number of non-discharging nozzles is 10 or more.

[0141] [Table 7]

[0142] [Table 8]

[0143] Examples of embodiments of the present invention include the following: <1> An ink containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. It comprises a nozzle plate having a liquid-repellent layer containing a silicone resin, and an ink ejection means for ejecting the ink, The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The ink ejection device is characterized in that the content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink. <2> The SP value of the aforementioned organic solvent is 9.0 or more and 10.6 or less. <1> This is the ink ejection device described above. <3> The content of the white pigment is 8% by mass or more and 11% by mass or less relative to the ink. <1> from <2> It is an ink ejection device as described in any of the following. <4> The processing solution having a polyvalent metal salt and water <1> from <3> It is an ink ejection device as described in any of the following. <5> The polyvalent metal salt is at least one of calcium chloride and calcium nitrate. <4> This is the ink ejection device described above. <6> The aforementioned ink container further comprises an ink container containing the aforementioned ink. <1> from <5> It is an ink ejection device as described in any of the following. <7> The processing liquid container further comprises a processing liquid container containing the processing liquid. <1> from <6> It is an ink ejection device as described in any of the following. <8> The aforementioned <1> from <7> Using the ink ejection device described in any of the above, The ink ejection method is characterized by including an ink ejection step of ejecting the aforementioned ink. <9> The recording medium is made of cloth. <8> This is the ink ejection method described in [the relevant document]. <10> A process of applying a treatment solution containing a polyvalent metal salt and water, The invention includes an ink ejection process in which an ink ejection means equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin ejects an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink. This is a method for manufacturing ink ejected material, characterized by the following features. <11> A means for applying a treatment solution containing a polyvalent metal salt and water, An ink container comprising a nozzle plate having a liquid-repellent layer containing silicone resin, containing an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water, It has an ink ejection means for ejecting the aforementioned ink, The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink. This is an ink ejection apparatus characterized by the following features. <12> A white ink containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. This white ink is characterized in that the content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink. <13> A treatment solution containing a polyvalent metal salt and water, A set of inks containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. This is a set of processing solution and ink, characterized in that the content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink.

[0144] The aforementioned <1> from <7> The ink ejection device described in any of the above <8> from <9> The ink ejection method described in any of the above, <10> The method for manufacturing the ink ejected material described above <11> The manufacturing apparatus for ink ejection described above, <12> The white ink described above, and the above <13> The set of processing solution and ink described herein can solve the aforementioned problems of the past and achieve the objectives of the present invention. [Explanation of Symbols]

[0145] 12 Medium 14 Liquid containers 26 Liquid dispensing heads 260 Discharge surface 30 First flow channel member 31 Nozzle base material 32 Communication board 34 Pressure chamber substrate 35 Liquid repellent layer 42 Vibration section 44 Piezoelectric elements 441 1st electrode 442 2nd electrode 443 Piezoelectric layer 45 Wiring board 48 Second flow channel member 482 connection ports 52 Nozzle Plate 54 Vibration absorber 60 Supply liquid chamber 61 Supply route 63 Communication path C Pressure Chamber Fa surface Fb surface L1 First Nozzle Row L2 Second nozzle row O Virtual surface N Nozzle P1 Part 1 P2 2nd part Ra space R1 First circulation channel R2 Second circulation channel S Circulating fluid chamber 100 Ink ejection device 110 Pre-treatment liquid application section 120 Ink ejection section 410 Containment container 411 Detention Unit 413 Outlet 414 Storage container case [Prior art documents] [Patent Documents]

[0146] [Patent Document 1] Japanese Patent Publication No. 2003-019803 [Patent Document 2] Patent No. 5105901 [Patent Document 3] Patent No. 6319628

Claims

1. An ink containing an organic solvent with an SP value of 9.0 or more and 12.0 or less, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water, A treatment solution containing a polyvalent metal salt and water, It comprises a nozzle plate having a liquid-repellent layer containing a silicone resin, and an ink ejection means for ejecting the ink, The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. An ink dispensing device characterized in that the content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink.

2. The ink ejection device according to claim 1, wherein the SP value of the organic solvent is 9.0 or more and 10.6 or less.

3. The ink ejection device according to any one of claims 1 to 2, wherein the content of the white pigment is 8% by mass or more and 11% by mass or less relative to the ink.

4. The ink ejection device according to claim 1, wherein the polyvalent metal salt is at least one of calcium chloride and calcium nitrate.

5. The ink dispensing device according to any one of claims 1 to 4, further comprising an ink storage container containing the aforementioned ink.

6. The ink dispensing device according to any one of claims 1 to 5, further comprising a processing liquid container containing the processing liquid.

7. Using the ink ejection device according to any one of claims 1 to 6, An ink ejection method characterized by including an ink ejection step of ejecting the aforementioned ink.

8. The ink ejection method according to claim 7, wherein the recording medium for ejecting the ink is a cloth.

9. A process of applying a treatment solution containing a polyvalent metal salt and water, The invention includes an ink ejection process in which an ink ejection means equipped with a nozzle plate having a liquid-repellent layer containing a silicone resin ejects an ink containing an organic solvent with an SP value of 9.0 to 12.0, a white pigment, a polyurethane resin with a glass transition temperature (Tg) of 0°C or less, and water. The content of the aforementioned organic solvent is 0.5% by mass or more and 2.5% by mass or less relative to the ink. The content of the white pigment is 6% by mass or more and 15% by mass or less relative to the ink. A method for manufacturing ink ejected material, characterized by the following:

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