Liquid discharge apparatus, printing apparatus, and printing method

Abstract

A liquid discharging device includes: a nozzle plate having a nozzle orifice for discharging liquid; a liquid chamber for supplying liquid to the nozzle orifice; a needle valve having a front end for moving in and out of the liquid chamber, the front end being used to close or open the nozzle orifice; and a hydrophobic layer on the surface of the nozzle plate, the hydrophobic layer having a concentration of less than 29 mJ / m 2 Surface free energy.

Description

Technical Field

[0001] This embodiment relates to a liquid discharge device, a printing apparatus, and a printing method. Background Technology

[0002] Solvent-based or water-based coatings are applied to roads, floors, and building walls using methods such as spraying, brushing, and roller coating.

[0003] For coating on surfaces such as roads, exterior or interior walls of buildings, walls of civil structures such as bridges or tunnels, and porous substrates, there are methods that use inkjet printing to spray ink from nozzles.

[0004] In inkjet printing, ink droplets are applied to the substrate in a dotted pattern, enabling the depiction of highly detailed text and patterns that were previously impossible with spraying, brushing, or roller coating methods.

[0005] Furthermore, a coating nozzle as a nozzle and a method for controlling it are proposed. The coating nozzle can prevent liquid leakage when the nozzle orifice is closed and obtain stable coating accuracy when the nozzle is open (for example, see Patent Document (PTL) 1). Summary of the Invention

[0006] Technical issues

[0007] The purpose of this embodiment is to provide a liquid discharge device that can stably discharge high-viscosity liquids used for the walls of civil structures such as roads, exterior or interior decoration of buildings, bridges or tunnels, and porous substrates, while simultaneously discharging liquids from a nozzle orifice in a continuously open state (the nozzle is exposed without a cap to prevent it from drying out) during printing.

[0008] Solution to the problem

[0009] According to one aspect of this disclosure, a liquid discharge device includes: a nozzle plate having a nozzle orifice for discharging liquid; a liquid chamber for supplying liquid to the nozzle orifice; a needle valve having a front end for moving in and out of the liquid chamber, the front end being used to close or open the nozzle orifice; and a hydrophobic layer on the surface of the nozzle plate, the hydrophobic layer having a concentration of less than 29 mJ / m 2 Surface free energy.

[0010] Effects of the present invention

[0011] According to one embodiment of the present disclosure, a liquid discharge device can be provided that can stably discharge high-viscosity liquids used for the walls of civil structures such as roads, exterior or interior decoration of buildings, bridges or tunnels, and porous substrates, while simultaneously discharging liquids from a nozzle orifice in a continuously open state (the nozzle is exposed without a cap to prevent it from drying out) during printing. Attached Figure Description

[0012] A more complete understanding of the embodiments of the present disclosure and its many incidental advantages and features can be readily obtained and understood from the following detailed description with reference to the accompanying drawings.

[0013] [ Figure 1 ]

[0014] Figure 1 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in the liquid discharge device according to the first embodiment of the present invention.

[0015] [ Figure 2 ]

[0016] Figure 2 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in a modified example 1 of the first embodiment of the present invention.

[0017] [ Figure 3 ]

[0018] Figure 3 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in a modified example 2 of the liquid discharge device according to the first embodiment of the present invention.

[0019] [ Figure 4 ]

[0020] Figure 4 This is a schematic structural diagram showing an example of a liquid discharge device according to an embodiment of the present invention, and a diagram showing an example of the state when the nozzle is closed.

[0021] [ Figure 5 ]

[0022] Figure 5 This is a schematic structural diagram showing an example of a liquid discharge device according to an embodiment of the present invention, and a diagram showing an example of the state when the nozzle is open.

[0023] [ Figure 6 ]

[0024] Figure 6 This is a schematic side view showing an example of a liquid discharge device of a printing apparatus according to an embodiment of the present invention.

[0025] [ Figure 7 ]

[0026] Figure 7 This is a schematic top view showing an example of a liquid discharge device of a printing apparatus according to an embodiment of the present invention.

[0027] [ Figure 8]

[0028] Figure 8 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in the liquid discharge device (nozzle 14) used in Comparative Example 5.

[0029] The accompanying drawings are intended to illustrate exemplary embodiments of the invention and should not be construed as limiting its scope. Unless explicitly stated otherwise, the drawings should not be considered to be drawn to scale. Furthermore, the same or similar reference numerals denote the same or similar components in several views. Detailed Implementation

[0030] In describing the embodiments illustrated in the accompanying drawings, specific terminology is used for clarity. However, the disclosure of this specification is not intended to be limited to the specific terminology chosen so far, and it should be understood that each particular element includes all technical equivalents that have similar functions, operate in a similar manner, and obtain similar results.

[0031] Embodiments of this disclosure will now be described with reference to the accompanying drawings. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0032] Liquid discharge device

[0033] According to an embodiment of the present invention, a liquid discharge device is a liquid discharge device comprising a nozzle unit for discharging liquid. The nozzle unit includes: a nozzle orifice; a nozzle plate forming the nozzle orifice; a liquid chamber for supplying liquid to the nozzle orifice; and a needle valve that, while moving forward and backward within the liquid chamber, closes or opens the nozzle orifice with its front end. The surfaces of the nozzle plate and the nozzle orifice having the nozzle orifice have a hydrophobic layer.

[0034] The nozzle disclosed in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2022-64482) has the following problem when printing with conventional high-viscosity inks used for printing on porous substrates such as walls of roads, exterior or interior buildings, and civil structures like bridges or tunnels: When ink is ejected from the nozzle in the open state during printing, it cannot be ejected stably. As a result, depending on the printed image, some nozzles may fail to eject ink for extended periods during printing. Therefore, there are drawbacks such as ink drop position shifting and ink falling off the nozzle due to lack of ejection.

[0035] Therefore, as a result of in-depth research into the conception of this invention, the following was discovered. Specifically, in the nozzle unit of the liquid discharge device, the surface of the nozzle plate and the surface of the nozzle hole 2 formed thereon have a surface free energy of less than 29 mJ / m². 2The nozzle plate has a hydrophobic layer. This reduces the surface free energy of the nozzle plate, making it easier to maintain ink repellency. Therefore, by maintaining ink repellency against ink that thickens due to drying, discharge deviation can be suppressed. As a result, even when printing with high-viscosity ink, ink can be stably discharged from the continuously liquid discharge device while the nozzle cap is open.

[0036] It should be noted that high viscosity ink refers to ink with a viscosity of 1000 mPa·s or higher at a shear rate of 1 (1 / s).

[0037] Hereinafter, the liquid discharge device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0038] First Embodiment

[0039] Figure 1 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in the liquid discharge device according to the first embodiment of the present invention.

[0040] The liquid discharge device according to the first embodiment includes a nozzle unit 10.

[0041] The nozzle unit 10 includes a base 1, a nozzle orifice 2 for discharging liquid, a nozzle plate 3 forming the nozzle orifice 2, a liquid chamber 4 for supplying liquid to the nozzle orifice, and a needle valve 5 in the liquid chamber 4.

[0042] A liquid-repellent layer 6 is provided on the outer surface of the nozzle plate 3 and on the surface of the nozzle orifice where the nozzle orifice 2 is formed. The liquid-repellent layer 6 is preferably provided on the entire outer surface of the nozzle plate 3 and the entire surface of the nozzle orifice where the nozzle orifice 2 is formed.

[0043] In addition, Figure 1 Although the illustration is omitted, it may also have a drive mechanism that moves the needle valve 5 forward and backward relative to the nozzle orifice 2.

[0044] The substrate 1 is the component that forms the outer wall of the nozzle unit 10. There are no particular restrictions on the material of the nozzle unit 10, and it can be appropriately selected according to the purpose.

[0045] Nozzle orifice 2 is an orifice for discharging liquid.

[0046] The diameter of the nozzle orifice 2 is not particularly limited and can be appropriately selected according to the purpose, but it is preferred to be 50 μm or more, and more preferably 100 μm or more. By making the diameter 50 μm or more, it is possible to discharge liquids used on the surfaces of roads, exterior or interior walls of buildings, walls of civil structures such as bridges or tunnels, and porous substrates.

[0047] The nozzle plate 3 forms a nozzle hole 2, and a liquid-repellent layer 6 is provided on the outer surface of the nozzle plate 3 and the surface on which the nozzle hole 2 is formed. The outer surface of the nozzle plate is the surface of the side of the nozzle plate opposite to the side on which the liquid chamber 4 is provided.

[0048] The lipolytic layer 6 has a surface free energy of less than 29 mJ / m 2 The layer. Because the nozzle unit 10 makes the surface free energy of the hydrophobic layer 6 less than 29 mJ / m². 2 This makes it easy to maintain the ink-repellent properties, and can maintain the ink-repellent properties even for inks that have thickened due to drying, thus suppressing discharge deviations. As a result, when printing with inks of high viscosity and high solids content, ink can be stably discharged from the liquid discharge device continuously in the open state.

[0049] There are no particular limitations on the methods used to calculate the surface free energy of hydrophobic layers, and the appropriate method can be selected depending on the purpose. For example, the DMo-501 contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.) can be used to perform the measurement according to the following steps.

[0050] Specifically, the surface free energy of the hydrophobic layer can be calculated by measuring the contact angle of the hydrophobic layer of three liquid samples with known surface free energy and solving the simultaneous equations.

[0051] When the surface free energy of the hydrophobic layer is set as γs, the dispersion force component of the surface energy of the hydrophobic layer is set as γsd, the dipole component of the surface energy of the hydrophobic layer is set as γsp, the hydrogen bond component of the surface energy of the hydrophobic layer is set as γsh, the surface free energy of the liquid sample is set as γL, the dispersion force component of the surface energy of the liquid sample is set as γLd, the dipole component of the surface energy of the liquid sample is set as γLp, the hydrogen bond component of the surface energy of the liquid sample is set as γLh, and the contact angle of the liquid sample on the hydrophobic layer is set as θ, the following equations (1), (2), and (3) hold true.

[0052] [Chemical Formula 1]

[0053]

[0054] For the hydrophobic layer, the contact angle θ of three known liquid samples (γL, γLd, γLp, and γLh) is measured. Substituting the measured contact angle θ into equation (3) above, three equations with γsd, γsp, and γsh as variables are formed. By solving these equations, γsd, γsp, and γsh can be obtained. By substituting the obtained γsd, γsp, and γsh into equation (1), the surface free energy γs of the hydrophobic layer can be calculated.

[0055] Equations (1) and (2) above are formulas in the Kitazaki-Hata theory.

[0056] Equation (3) above is obtained by substituting the Kitazaki-Hata formula and the extended Fax formula into the Dupre formula, and then further transforming the Young-Dupre formula using this substitution formula.

[0057] Besides Kitazaki-Hata, there are also theoretical formulas from Owens-Wendt and Kaelble-Uy. The surface free energy of a hydrophobic layer can be calculated by measuring the contact angles of the hydrophobic layers of two liquid samples with known surface free energies, substituting them into the Young-Dupre formula, and solving the simultaneous equations.

[0058] The hydrophilic layer 6 preferably contains at least one of silicon (Si) and fluorine (F), and may also contain other components as needed.

[0059] Fluorine (F) can be included as a fluorine compound in the liquephobic layer 6.

[0060] There are no particular restrictions on fluorinated compounds; they can be selected appropriately depending on the purpose. The fluorinated compounds mentioned above are not particularly limited, but examples include krytoxFSL (manufactured by DuPont), krytox FSH (manufactured by DuPont), Fomblin Z (manufactured by Solvay Solexis), Fluorolink S10 (manufactured by Solvay Solexis), OPTOOL DSX (manufactured by Daikin Industries), Fluorolink C10 (manufactured by Solvay Solexis), Moresco Phosfarol A20H (manufactured by Matsumura Oil Research), MORESCO PHOSFAROL ADOH (manufactured by Matsumura Oil Research), MORESCO PHOSFAROL DDOH (manufactured by Matsumura Oil Research), FLUOROSURF FG5010 (manufactured by Fluoro Technology), FLUOROSURF FG5020 (manufactured by Fluoro Technology), FLUOROSURF FG5060 (manufactured by Fluoro Technology), and FLUOROSURF FG5070. Fluorinated compounds include: DURASURF DP-500 (manufactured by Fluoro Technology), DURASURF DP-200 (manufactured by HARVES), DURASURF DS-5400 (manufactured by HARVES), DURASURF DH-100 (manufactured by HARVES), H-405TH (manufactured by HARVES), DH-610 (manufactured by HARVES), DS-6500 (manufactured by HARVES), DS-5800 (manufactured by HARVES), and DS-5935 (manufactured by HARVES). A single fluorinated compound can be used, or two or more can be used in combination. Among these fluorinated compounds, modified perfluoropolyoxyheterobutane (manufactured by Daikin Industries, Ltd., OPTOOL DSX) is preferred.

[0061] Silicon (Si) can be included as a silicon compound in the liquid-phobic layer 6.

[0062] There are no particular limitations on the aforementioned silicon compounds; they can be appropriately selected according to the purpose. Examples include organosilicon resins, but the choice is not limited to these. Organosilicon resins are resins with a basic backbone formed by siloxane bonds between silicon (Si) and oxygen (O). Organosilicon resins are commercially available in various forms such as oils, resins, and elastomers. In addition to the hydrophobicity that is of interest in this embodiment, they also possess various properties such as heat resistance, mold release properties, defoaming properties, and adhesive properties. Examples of organosilicon resins include room temperature curing types, heat curing types, and UV curing types, but the choice is not limited to these; it can be selected according to the manufacturing method and intended use.

[0063] In a liquid discharge device according to an embodiment of the present invention, a treatment membrane may also be provided between the substrate and the hydrophobic layer comprising at least one of silicon (Si) and fluorine (F).

[0064] There are no particular limitations on the treatment film, and it can be appropriately selected according to the purpose. Examples of treatment films include SiO2 oxide films and films formed by Si and transition metals (e.g., tantalum, niobium, titanium, hafnium, zirconium, tungsten) bonded via O, but are not limited to these. In the case of SiO2 oxide films, moisture is not easily permeable, and therefore, the substrate is not easily corroded. In the case of films in which Si and transition metals are bonded via O, a passivation film with slightly soluble transition metal oxide properties is formed at a wide pH range, and a more stable film can be formed even under acidic or alkaline conditions.

[0065] When forming a liquefying layer containing at least one of silicon (Si) and fluorine (F), the liquefying layer may contain a silanol compound having silanol groups (Si-OH). The Si-OH can condense and bond to the substrate or the treated film within the silanol groups. When the liquefying layer contains silanol groups (Si-OH), the silanol groups of the substrate and the silanol groups of the treated film undergo hydrogen bonding. Furthermore, by setting the temperature above room temperature, the dehydration condensation reaction of the hydrogen bonding sites proceeds, and Si forms covalent bonds between the substrate and the treated film via O, thus improving the adhesion.

[0066] The silanol groups in the liquefaction layer react with each other to form siloxane-bonded Si-O-Si, thereby increasing the strength of the liquefaction layer. For oxygen deficiencies in the oxidized state of the substrate surface, the silanol compounds in the liquefaction layer replenish oxygen, thus homogenizing the surface condition of the substrate, eliminating sites that could become corrosion initiation points, and improving corrosion resistance.

[0067] Whether the liquefaction layer 6 contains at least one of silicon (Si) and fluorine (F) can be determined by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIM), energy-dispersive X-ray spectroscopy (EDS) or electron probe microscopy (EPMA), fluorescence X-rays, etc. Furthermore, using XPS or TOF-SIM, the elemental distribution in a depth section perpendicular to the outermost surface of the liquefaction layer and towards the surface in contact with the substrate or needle valve can be analyzed, thereby enabling the analysis of silicon (Si) and fluorine (F) in the depth direction of the cross-section of the liquefaction layer 6.

[0068] The average thickness of the hydrophobic layer 6 is not particularly limited and can be appropriately selected according to the purpose, preferably 0.0001 μm or more and 5 μm or less. In order to reduce the surface free energy of the hydrophobic layer and improve its wear resistance, when the hydrophobic layer contains silicon (Si), the thickness is more preferably 0.5 μm or more and 5 μm or less, and when the hydrophobic layer contains fluorine (Si), the thickness is more preferably 0.0005 μm or more and 0.02 μm or less.

[0069] The liquid chamber 4 has a structure for holding liquid and is formed by a base 1 that serves as the outer wall in the nozzle unit 10 and a nozzle plate 3 that forms the nozzle orifice 2.

[0070] The needle valve 5 is located inside the liquid chamber 4. When the needle valve 5 moves forward or backward within the liquid chamber 4, the nozzle orifice 2 can be closed or opened using the front end of the needle valve 5. The forward and backward movement of the needle valve 5 can be controlled, for example, by a drive mechanism.

[0071] The pressure applied to the liquid chamber 4 by the needle valve 5 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 0.2 MPa or higher. When the pressure is 0.2 MPa or higher, high-viscosity ink can be discharged.

[0072] There are no particular restrictions on the drive mechanism, and it can be appropriately selected according to the purpose. Examples of drive mechanisms include electromagnetic drive mechanisms and drive mechanisms using piezoelectric elements, but they are not limited to these.

[0073] Variation 1 of the first embodiment

[0074] Figure 2 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in a modified example 1 of the first embodiment of the present invention.

[0075] Compared to the first embodiment, in addition to the outer surface of the nozzle plate 3 and the nozzle hole surface on which the nozzle hole 2 is formed, the modified example 1 of the first embodiment also has a hydrophobic layer 6 on the surface of the nozzle plate 3 on which the liquid chamber 4 is formed (hereinafter referred to as the "inner surface of the nozzle plate 3"). As a result, when a liquid with a viscosity higher than that of the first embodiment is discharged for printing, the liquid can be stably discharged from the nozzle which is continuously in the open state.

[0076] Variation 2 of the first embodiment

[0077] Figure 3 This is a schematic cross-sectional view enlarged to show an example of the nozzle orifice and the front end of the needle valve in a modified example 2 of the liquid discharge device according to the first embodiment of the present invention.

[0078] Compared to Modification 1 of the First Embodiment, Modification 2 of the First Embodiment also includes a hydrophobic layer 6 at the front end of the needle valve 5. Therefore, when printing with a liquid of higher viscosity than that of the First Embodiment and Modification 1 of the First Embodiment, the liquid can be stably discharged from the nozzle in a continuously open state.

[0079] Figure 4 This is a schematic structural diagram showing an example of a liquid discharge device according to an embodiment of the present invention, and a diagram showing an example of the state when the nozzle is closed. Figure 5 This is a schematic structural diagram showing an example of a liquid discharge device according to an embodiment of the present invention, and a diagram showing an example of the state when the nozzle is open.

[0080] exist Figure 4 and Figure 5 In this embodiment, the liquid discharge device includes a nozzle orifice 2 disposed on the front surface of the substrate 1, a liquid chamber 4 supplying ink to the nozzle orifice 2, a needle valve 5 located in the liquid chamber 4 and closed or opened by its front end, a movable iron core 8 fixed behind the needle valve, a fixed iron core 11 disposed opposite to the movable iron core 8, an electromagnetic solenoid 12, and a spring material 19 disposed between the movable iron core 8 and the fixed iron core 11. The movable iron core 8, the spring material 19, the fixed iron core 11, and the electromagnetic solenoid 12 constitute an electromagnetically driven drive mechanism for repeating the closing and opening actions of the needle valve 5 on the nozzle orifice 2.

[0081] To prevent ink in the liquid chamber 4 from flowing out into the drive mechanism storage space 9 of the drive mechanism, an elastomer diaphragm 7 is provided to surround the needle valve 5, and pressure P is applied to the ink in the liquid chamber 4 via the ink input flow path 22.

[0082] To prevent pressurized ink from leaking between the elastomer diaphragm 7 and the needle valve 5, a pressure P of the same degree as the pressure applied to the ink via the pressurization passage 13 is applied to the gas or liquid in the drive mechanism housing 9.

[0083] Figure 4 This indicates that the needle valve 5 is in the closed state of the nozzle orifice 2. At this time, no current flows through the solenoid 12, and the movable iron core 8 and the needle valve 5 following the movable iron core 8 are pushed forward by the spring material 19. Therefore, the nozzle orifice 2 is closed.

[0084] on the other hand, Figure 5 This indicates that the needle valve 5 is in the state of opening the nozzle orifice 2. At this time, current flows through the electromagnetic solenoid 12, and the movable iron core 8 is attracted by the fixed iron core 11. Therefore, the needle valve 5 retracts and opens the nozzle orifice 2.

[0085] As described above, for example, by properly controlling the supply of pulse current to the solenoid 12, the nozzle orifice 2 is opened and closed by the needle valve 5 to discharge ink, thus enabling the printing of three-dimensional objects.

[0086] Reference numeral 17 indicates a pressurized ink reservoir connected to the liquid chamber 4 via circulation path 20. Ink is supplied from ink reservoir 17 to ink inlet passage 22, and ink discharged from ink outlet passage 22 is returned to ink reservoir 17 via pump 18. By circulating the pressurized ink in this way, separation and sedimentation of ink components can be prevented, and the variety of usable inks can be expanded.

[0087] The fixed iron core 11 is connected to the gap adjusting bolt 15 and nut 16. By rotating the nut 16, the position of the fixed iron core 11 can be changed. This change range is the distance between the needle valve 5 and the nozzle orifice 2, that is, the change range of the nozzle gap, which can be adjusted by the bolt 15. Reference numeral 14 indicates a spring used to prevent the screw from loosening.

[0088] The amount of ink discharged can be controlled by adjusting the energizing time of the solenoid 12, that is, the opening time of the nozzle orifice 2.

[0089] By adjusting the gap between the nozzles using bolt 15 and nut 16, the amount of ink discharged can be increased.

[0090] In this embodiment, there are no particular limitations on the liquid that can be used, as long as it is fluid and can be discharged from the nozzle. Examples of liquids include, but are not limited to, ink, paint, and processing liquid.

[0091] The liquid is used for coating road surfaces, exteriors, and porous substrates.

[0092] ink

[0093] The ink of the present invention contains solvent, resin, and tackifying particles, and may further contain other components as needed.

[0094] The ink of this invention exhibits pseudoplastic flow. Therefore, after the ink is discharged onto asphalt or similar road surfaces, its viscosity increases, making it difficult to penetrate the interior of the road surface, resulting in a thicker coating and improved concealment. Furthermore, when the ink is discharged from the nozzle using an inkjet method, its viscosity decreases, thus improving discharge stability.

[0095] In addition, even on the walls of buildings, bridges, tunnels and other civil structures, the ink viscosity increases after it is discharged. Therefore, it is possible to thicken the coating on the wall while suppressing ink dripping, thereby improving the concealment.

[0096] The preferred viscosity for the ink is at 25°C and a shear rate of 1 second. -1 The viscosity is above 1000 mPa·s.

[0097] The ink of this invention exhibits pseudoplastic flow; therefore, after being sprayed onto asphalt or similar surfaces, the ink viscosity increases, making it difficult to penetrate the interior of the surface, resulting in a thicker coating and improved concealment. Furthermore, when the ink is ejected from the nozzle using an inkjet method, the lower ink viscosity improves ejection stability.

[0098] Ink at 25°C and a shear rate of 1 second -1 The preferred viscosity is 1000 mPa·s or higher.

[0099] From the perspective of achieving better discharge stability, the ink is suitable for use at 25°C and a shear rate of 5000 s. -1 The viscosity is preferably 130 mPa·s or less, more preferably 30 mPa·s or more and 80 mPa·s or less.

[0100] There are no particular limitations on the method for measuring the viscosity, and it can be appropriately selected according to the purpose. For example, the cone plate (cone radius: 25 mm, cone angle: 1°) of MCR301 (manufactured by Anton Parr) can be used for measurement.

[0101] Thickening particles

[0102] The so-called "thickening property" of the aforementioned thickening particles refers to the characteristic that, in solutions containing these particles such as inks, the viscosity increases when the shear rate decreases and decreases when the shear rate increases. When 60g of thickening particles are dispersed in 100mL of water at 25°C, the shear rate is 0.1s. -1 Under the condition that the viscosity is above 100 mPa·s and below 900,000 mPa·s, at a shear rate of 5000 s -1Under certain conditions, the viscosity is above 1 mPa·s and below 200 mPa·s, and it exhibits the characteristic that the viscosity increases when the shear rate is decreased and decreases when the shear rate is increased.

[0103] The ink of the present invention, by containing the aforementioned thickening particles, allows for control of ink viscosity. Specifically, by controlling the viscosity at a shear rate of 1 second... -1 Under normal conditions, the ink viscosity at 25℃ should be controlled at 3.00×10⁻⁶. 3 Above mPa·s and 2.50 × 10 4 At a shear rate below mPa·s, a thick coating of ink can be formed, exhibiting excellent substrate concealment. Furthermore, by applying a shear rate of 5000 s... -1 Under certain conditions, controlling the ink viscosity at 25℃ to below 130 mPa·s can improve the ink discharge stability.

[0104] Coatings with impact and abrasion resistance are required for surfaces such as roads, exterior or interior walls of buildings, and walls of civil structures such as bridges or tunnels. Therefore, coatings containing thickening particles are preferred to obtain coatings with high adhesion and high resistance to impact and abrasion.

[0105] There are no particular limitations on the thickening particles mentioned above, and they can be selected appropriately according to the purpose. Examples include fumed silica, precipitated silica, diatomaceous earth, saponin, sepiolite, talc, calcium carbonate, barium sulfide, and polyethylene oxide. These can be used individually or in combination of two or more. From the viewpoint of ink film adhesion, calcium carbonate and talc are preferred.

[0106] Alternatively, mixed crystals can also be used as the aforementioned thickening particles.

[0107] Alternatively, both the aforementioned thickening particles and non-particle thickeners can be used together. Examples of non-particle thickeners include thickeners that melt into the coating in a resinous form to exert a "thickening" effect.

[0108] There are no particular restrictions on the calcium carbonate used, and it can be selected appropriately according to the purpose; for example, commercially available products can be used.

[0109] There are no particular restrictions on the commercially available products mentioned above; you can choose appropriately according to your purpose. For example, you can list UP-G (manufactured by Immeris Specialites Japan, 100% solid content), luminous (manufactured by Maruo CALCIUM, 100% solid content), Caltex 5 (manufactured by Maruo CALCIUM, 100% solid content), Super #2000 (manufactured by Maruo CALCIUM, 100% solid content), Super SSS (manufactured by Maruo CALCIUM, 100% solid content), Softon 1500 (manufactured by Bikhoku Powdered Chemical Industry Co., Ltd., 100% solid content), Softon 3200 (manufactured by Bikhoku Powdered Chemical Industry Co., Ltd., 100% solid content), BF100 (manufactured by Bikhoku Powdered Chemical Industry Co., Ltd., 100% solid content), Lighton A-5 (manufactured by Bikhoku Powdered Chemical Industry Co., Ltd., 100% solid content), etc.

[0110] There are no particular restrictions on the type of talc used; it can be selected appropriately according to the purpose, for example, commercially available products can be used.

[0111] There are no particular restrictions on the commercially available products mentioned above, and you can choose appropriately according to your purpose. For example, you can list Nano AceD-600 (Talc Corporation of Japan, 100% solid content), etc.

[0112] There are no particular limitations on the content of the aforementioned thickening particles, which can be appropriately selected according to the purpose, but it is preferable to have a content of 20.0% by mass or more and 55.0% by mass or less relative to the total amount of the ink. This makes it easier to control the viscosity of the ink.

[0113] resin

[0114] There are no particular limitations on the resins mentioned above; they can be selected appropriately according to the purpose. Examples include polyurethane resins, polyester resins, acrylic resins, vinyl acetate resins, styrene resins, butadiene resins, styrene-butadiene resins, vinyl chloride resins, acrylic-styrene resins, and acrylic-silicone resins. One of these can be used alone, or two or more can be used in combination.

[0115] As the aforementioned resin, resin particles composed of these resins can also be used. By dispersing the aforementioned resin particles in water as a dispersion medium to form a resin emulsion, ink can be obtained by mixing with materials such as colorants or organic solvents.

[0116] The resin particles described above can be appropriately synthesized resin particles or commercially available products. These resin particles can be used alone or in combination of two or more.

[0117] There are no particular limitations on the glass transition temperature of the above-mentioned resin, and it can be appropriately selected according to the purpose. Considering the cracking of the coating when it is thick, it is preferably below 15°C, and more preferably below 0°C.

[0118] There are no particular limitations on the method for determining the glass transition temperature mentioned above, and it can be appropriately selected according to the purpose. For example, in the case of resin emulsion, it can be determined by the following method.

[0119] Specifically, 4g of resin emulsion was placed in a petri dish made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) with a diameter of 50 mm, and allowed to spread evenly. The mixture was then dried at 50°C for one week to obtain a resin film. 5.0 mg of the obtained resin film was placed in an aluminum sample container, which was then placed on a support unit and set up in an electric furnace.

[0120] Next, under a nitrogen atmosphere, the temperature was increased from 0°C to 150°C at a heating rate of 10°C / min. Then, the temperature was decreased from 150°C to -80°C at a cooling rate of 5°C / min. Finally, the temperature was increased to 150°C again at a heating rate of 10°C / min, and the DSC curve was measured.

[0121] Using the analytical program in the DSC-60 system, the inflection point during the second heating is analyzed by the midpoint method, and the glass transition temperature (also known as the glass transition point) (Tg) is determined from the obtained DSC curve.

[0122] There are no particular restrictions on the content of the aforementioned resin, and it can be appropriately selected according to the purpose. From the viewpoint of the strength of the dried film, it is preferred to be 5% by mass or more and 30% by mass or less.

[0123] The above content indicates the content of the solid component of the resin.

[0124] The ratio (A / B) of the content of the thickening particles (A) to the content of the solid components of the resin (B) is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.8 or more, more preferably 1.0 or more, and even more preferably 1.5 or more. When the ratio (A / B) is 0.8 or more, it has excellent discharge stability, and by forming a thick coating film, the substrate has excellent concealment.

[0125] solvent

[0126] There are no particular restrictions on the solvents mentioned above; they can be selected appropriately according to the purpose. For example, organic solvents and water can be listed.

[0127] There are no particular restrictions on the organic solvents used, and they can be selected appropriately according to the purpose. Examples include polyol alkyl ethers, polyol aryl ethers, polyols, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, etc.

[0128] There are no particular restrictions on the types of polyols mentioned above. They can be selected appropriately according to the purpose. From the perspective of functioning as a wetting agent and achieving excellent spray stability, diols, triols, etc. can be listed.

[0129] Examples of the aforementioned diols include 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-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, and 1,5-hexanediol.

[0130] Examples of the aforementioned triols include glycerol, 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, and petriol.

[0131] There are no particular restrictions on the types of polyol alkyl ethers mentioned above, and they can be selected appropriately according to the purpose. For example, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. can be listed.

[0132] There are no particular restrictions on the polyol aryl ethers mentioned above, and they can be selected appropriately according to the purpose. For example, ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether can be listed.

[0133] There are no particular limitations on the nitrogen-containing heterocyclic compounds mentioned above, and they can be appropriately selected according to the purpose. For example, nitrogen-containing heterocyclic compounds such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolium ketone, ε-caprolactam, and γ-butyrolactone can be listed.

[0134] There are no particular restrictions on the amides mentioned above, and they can be selected appropriately according to the purpose. For example, formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, etc. can be listed.

[0135] There are no particular restrictions on the amines mentioned above; they can be selected appropriately according to the purpose. For example, monoethanolamine, diethanolamine, triethylamine, etc. can be listed.

[0136] There are no particular restrictions on the sulfur-containing compounds mentioned above; they can be appropriately selected according to the purpose. Examples include dimethyl sulfoxide, sulfolane, and thiodiethanol.

[0137] The content of the above-mentioned organic solvent is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of excellent drying properties, it is preferably 7.0% by mass or less, and more preferably 5.0% by mass or less.

[0138] There are no particular restrictions on the water content mentioned above, and it can be appropriately selected according to the purpose. However, from the viewpoint of ink drying and spraying reliability, it is preferable to be 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 60% by mass or less, relative to the total amount of ink.

[0139] Other ingredients

[0140] There are no particular restrictions on the other components mentioned above, and they can be selected appropriately according to the purpose. For example, surfactants, colorants, defoamers, preservatives and mildew inhibitors, rust inhibitors, pH adjusters, film-forming aids, etc. can be listed.

[0141] surfactants

[0142] There are no particular restrictions on the surfactants mentioned above; they can be selected appropriately according to the purpose. Examples include silicone surfactants, fluorinated surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants. One of these can be used alone, or two or more can be used in combination.

[0143] As the aforementioned silicon-based surfactant, a silicon-based surfactant that does not decompose even at high pH is preferred.

[0144] There are no particular limitations on the aforementioned silicone-based surfactants; they can be selected appropriately according to the purpose. Examples include silicone-based surfactants with modified groups such as polyether-modified silicone surfactants, side-chain modified polydimethylsiloxanes, two-terminal modified polydimethylsiloxanes, single-terminal modified polydimethylsiloxanes, and side-chain two-terminal modified polydimethylsiloxanes. These can be used individually or in combination of two or more.

[0145] There are no particular restrictions on the modified groups mentioned above, and they can be appropriately selected according to the purpose. From the perspective of exhibiting good properties as a water-based surfactant, modified groups having polyoxyethylene groups, polyoxyethylene polyoxypropylene groups are preferred.

[0146] As the aforementioned silicon-based surfactants, appropriate synthesizers or commercially available products can be used.

[0147] As for the aforementioned commercially available products, there are no particular restrictions, and appropriate choices can be made according to the purpose. For example, they can be obtained from companies such as BYK CHEMIE, Shin-Etsu Chemical Co., Ltd., Silicon Dow Corning Toray Co., Ltd., Japan Latex Co., Ltd., and KYOEISHA CHEMICAL Co., Ltd.

[0148] There are no particular limitations on the polyether-modified silicone surfactants mentioned above; they can be appropriately selected according to the purpose. Examples include compounds that introduce a polyepoxide structure into the Si side chain of a dimethylsiloxane.

[0149] There are no particular limitations on the polyether-modified silicone surfactants mentioned above, and they can be appropriately selected according to the purpose. Examples include compounds represented by the following general formula (S-1) that introduce a polyepoxide structure into the Si side chain of a dimethylpolysiloxane.

[0150] [Chemical Formula 2]

[0151] General formula (S-1):

[0152]

[0153] (In the above general formula (S-1), m, n, a, and b are independent and represent integers, R represents alkylene, and R' represents alkyl.)

[0154] Commercially available products can be used as the aforementioned polyether-modified silicone surfactants.

[0155] There are no particular restrictions on the commercially available products mentioned above. You can choose appropriately according to your purpose. Examples include KF-618, KF-642, KF-643 (Shin-Etsu Chemical Co., Ltd.), EMLEX-SS-5602, SS-1906EX (Japan Latex Co., Ltd.), FZ-2105, FZ-2118, FZ-2154, FZ-2161, FZ-2163, FZ-2164 (Silicon Dow Corning Toray Co., Ltd.), BYK-33, BYK-387 (BYK CHEMIE Co., Ltd.), TSF4440, TSF4452, TSF4453 (Toshiba Silicon Co., Ltd.), etc.

[0156] There are no particular limitations on the aforementioned fluorinated surfactants; they can be appropriately selected according to the purpose. From the perspective of low foaming performance, preferred surfactants include, for example, perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate compounds, adducts of perfluoroalkyl ethylene oxide, and polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups on the side chains. These can be used alone or in combination of two or more.

[0157] There are no particular limitations on the perfluoroalkyl sulfonic acid compounds mentioned above; they can be appropriately selected according to the purpose. Examples include perfluoroalkyl sulfonic acids and perfluoroalkyl sulfonates.

[0158] There are no particular limitations on the perfluoroalkyl carboxylic acid compounds mentioned above; they can be appropriately selected according to the purpose. Examples include perfluoroalkyl carboxylic acids and perfluoroalkyl carboxylate salts.

[0159] There are no particular limitations on the polyoxyalkylene ether polymer compounds having perfluoroalkyl ether groups in the side chains mentioned above. They can be appropriately selected according to the purpose. Examples include sulfate salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chains and salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in the side chains.

[0160] There are no particular restrictions on the counterions that serve as salts for these fluorinated surfactants; they can be selected appropriately according to the purpose. Examples include Li, Na, K, NH4, NH3CH2CH2OH, NH2(CH2CH2OH)2, and NH(CH2CH2OH)3.

[0161] There are no particular limitations on the fluorinated surfactants mentioned above, and they can be appropriately selected according to the purpose. However, compounds with fluorinated carbon atoms numbering 2 to 16 are preferred, and compounds with fluorinated carbon atoms numbering 4 to 16 are more preferred.

[0162] 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 due to their low foaming properties, and fluorinated surfactants represented by general formulas (F-1) and (F-2) are particularly preferred.

[0163] [Chemical Formula 3]

[0164] General formula (F-1):

[0165]

[0166] (In compounds represented by the above general formula (F-1), in order to impart water solubility, m is preferably an integer from 0 to 10, and n is preferably an integer from 0 to 40.)

[0167] [Chemical Formula 4]

[0168] General formula (F-2):

[0169] C n F 2n+1 -CH2CH(OH)CH2-O-(CH2CH2O) a -Y

[0170] (In compounds 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 from 4 to 6), or CpF 2p+1 (p is an integer from 1 to 19. n is an integer from 1 to 6. a is an integer from 4 to 14.)

[0171] Commercially available products can also be used as the aforementioned fluorinated surfactants.

[0172] As products sold in this city, there are no special restrictions; appropriate choices can be made according to the purpose. Examples include: SURFLONS-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by ASAHI GLASS); FLUORAD FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M); MEGAFACE F-470, F-1405, F-474 (all manufactured by Dai Nippon Ink Chemical Industry Co., Ltd.); ZONYL TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, CAPSTONE. FS-30, FS31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (all manufactured by NEOS); POLY FOX PF-136A, PF-156A, PF-151N, PF-154, PF-159 (manufactured by OMNOVA); Unidyne DSN-403N (manufactured by Daikin Industries), etc. Among them, considering the improvement of print quality, especially the significant improvement of color development, paper penetration, wettability and uniform dyeing, Chemours FS-3100, FS-34, FS-300, NEOS FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW, OMNOVA POLY FOX PF-151N and Daikin Industries Unidyne DSN-403N are particularly preferred.

[0173] There are no particular limitations on the amphoteric surfactants mentioned above; they can be appropriately selected according to the purpose. Examples include lauryl aminopropionate, lauryl dimethyl betaine, stearoyl dimethyl betaine, and lauryl dihydroxyethyl betaine. These can be used alone or in combination of two or more.

[0174] There are no particular limitations on the aforementioned nonionic surfactants; they can be appropriately selected according to the purpose. Examples include polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, and ethylene oxide adducts of ethynyl alcohol. These can be used individually or in combination of two or more.

[0175] There are no particular limitations on the anionic surfactants mentioned above; they can be appropriately selected according to the purpose. Examples include polyoxyethylene alkyl ether acetates, dodecylbenzene sulfonates, laurates, and polyoxyethylene alkyl ether sulfates. One of these can be used alone, or two or more can be used in combination.

[0176] There are no particular restrictions on the content of the aforementioned surfactants, and they can be appropriately selected according to the purpose. From the perspective of excellent wettability, discharge stability and image quality improvement, it is preferred to be 0.001% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 5% by mass or less.

[0177] color material

[0178] There are no particular restrictions on the aforementioned coloring materials. They can be appropriately selected according to the purpose; for example, pigments and dyes can be listed. Among the aforementioned pigments, examples include inorganic pigments and organic pigments. These can be used alone or in combination of two or more. Furthermore, mixed crystals can also be used.

[0179] There are no particular restrictions on the pigments mentioned above. Appropriate choices can be made according to the intended purpose. For example, black pigments, yellow pigments, magenta pigments, cyan pigments, white pigments, green pigments, orange pigments, and glossy or metallic pigments such as gold or silver can be listed.

[0180] There are no particular restrictions on the aforementioned inorganic pigments. Appropriate selections can be made according to the intended purpose. Examples include titanium dioxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, chrome yellow, and carbon black manufactured by known methods such as the contact process, furnace process, and thermal process.

[0181] There are no particular limitations on the organic pigments mentioned above. Appropriate selection can be made according to the purpose. For example, azo pigments, polycyclic pigments (e.g., phthalocyanine pigments, perylene pigments, perynone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindolinone pigments, isoindolineone pigments, quinolineone pigments, etc.), dye chelates (e.g., basic dye-type chelates, acid dye-type chelates, etc.), nitro pigments, nitroso pigments, aniline black, resin hollow particles, inorganic hollow particles, etc., are preferred among the pigments listed above. Those with good solvent affinity are preferred.

[0182] Specifically, examples of organic pigments include carbon black (CI Pigment Black 7) used for black purposes such as furnace black, lamp black, acetylene black, and channel black; metallic pigments such as copper, iron (CI Pigment Black 11), and titanium oxide; and organic pigments such as aniline black (CI Pigment Black 1). Furthermore, examples of organic pigments used for color purposes include CI Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 138, 150, 153, 155, 180, and 18. 5, 213, CI Pigment Orange 5, 13, 16, 17, 36, 43, 51, CI Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2, 48:2 (Long-lasting Red 2B(Ca)), 48:3, 48:4, 49:1, 52:2, 53:1, 57:1 (Brilliant Carmine 6B), 60:1, 63:1, 63:2 64:1, 81, 83, 88, 101 (Carmine), 104, 105, 106, 108 (Cadmium Red), 112, 114, 122 (Nagoridon Magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 207, 208, 209, 2 13, 219, 224, 254, 264, CI Pigment Violet 1 (Rhodamine Lake), 3, 5:1, 16, 19, 23, 38, CI Pigment Blue-1, 2, 15 (Phthalocyanine Blue), 15:1, 15:2, 15:3, 15:4 (Phthalocyanine Blue), 16, 17:1, 56, 60, 63, CI Green 1, 4, 7, 8, 10, 17, 18, 36, etc.

[0183] As the aforementioned pigment, it is preferable to disperse it in the aforementioned ink for use.

[0184] Examples of methods for dispersing the aforementioned pigments in ink include introducing hydrophilic functional groups into the pigment to make it a self-dispersible pigment, coating the pigment surface with resin to disperse it, and using a dispersant to disperse it.

[0185] Examples of self-dispersible pigments that incorporate hydrophilic functional groups include pigments with added sulfone or carboxyl groups that are dispersible in water (e.g., carbon).

[0186] Examples of pigments with resin-coated surfaces include pigments contained in microcapsules that are dispersible in water. This can also be referred to as resin-coated pigments. In this case, the pigment added to the ink does not need to be completely covered by resin; without impairing the effects of the invention, it may contain uncovered pigment, and partially coated pigment may be dispersed in the ink.

[0187] As a method of dispersing pigments using dispersants, examples include well-known low-molecular-weight dispersants, such as interfacial activators, and high-molecular-weight dispersants. Depending on the pigment, dispersants may include anionic, cationic, amphoteric, and nonionic interfacial activators. Suitable dispersants may also include RT-100 (a nonionic interfacial activator) or naphthalenesulfonic acid sodium formaldehyde condensate manufactured by Takemoto Oils Co., Ltd. Dispersants can be used alone or in combination of two or more.

[0188] There are no particular restrictions on the dyes mentioned above. Appropriate selection can be made according to the purpose; for example, acid dyes, direct dyes, reactive dyes, and basic dyes can be listed. These can be used alone or in combination of two or more.

[0189] Examples of the aforementioned dyes include CI Acid Yellow 17, 23, 42, 44, 79, and 142; CI Acid Red 52, 80, 82, 249, 254, 289; CI Acid Blue 9, 45, 249; CI Acid Black 1, 2, 24, 94; CI Food Black 1, 2; CI Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173; CI Direct Red 1, 4, 9, 80, 81, 225, 227; CI Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202; CI Direct Black 19, 38, 51, 71, 154, 168, 171, 195; CI Reactive Red 14, 32, 55, 79, 249; CI Reactive Black 3, 4, 35, etc.

[0190] There are no particular restrictions on the content of the aforementioned colorant, and it can be appropriately selected according to the purpose. However, it is preferred to be 1.0% by mass or more and 15.0% by mass or less relative to the total amount of ink, and more preferably 1.0% by mass or more and 10.0% by mass or less.

[0191] The P99 particle size distribution, which serves as the ISO Max Distance (maximum distance) benchmark for the aforementioned ink, falls within the range of 0.1 μm to 100 μm. There are no particular limitations on this P99; it can be appropriately selected depending on the purpose, but preferably below 9 μm. This allows for further control of the shear rate in the aforementioned ink to be 5000 s.-1 The viscosity at 25°C. Furthermore, when P99 is 9 μm or less, in the printing apparatus, when there is a flow path with a width of tens to hundreds of μm in the flow path from ink supply to nozzle discharge, the ink flow in the flow path becomes smoother, which can improve discharge stability.

[0192] There are no particular limitations on the method for determining the particle size distribution P99 of the aforementioned ISO Max Distance. It can be appropriately selected according to the purpose. For example, the IF-3200 injection-type image resolution particle size analyzer can be used for the determination.

[0193] Specifically, ink can be diluted with water to allow observation of particles within the ink. Using an injection-type image resolution particle size analyzer IF-3200, the number of particles in the ink can be measured within the range of 0.1 μm to 100 μm, based on the ISO MaxDistance particle size distribution (P99). Since the dilution amount varies depending on the amount or size of the particle components in the ink, the dilution ratio needs to be adjusted to allow observation of individual particle sizes. In cases where the ink condenses in water, it can also be diluted using a non-condensing solvent (such as cyclohexane).

[0194] There are no particular limitations on the glass transition temperature of the dried film (hereinafter sometimes referred to as "coating") of the above ink, which can be appropriately selected according to the purpose, but it is preferably below 15°C.

[0195] There are no particular limitations on the method for determining the glass transition temperature mentioned above. It can be appropriately selected according to the purpose, and a differential scanning calorimeter (TA-60 WS and DSC-60, manufactured by Shimadzu Corporation) can be used for the determination.

[0196] Specifically, 4g of ink was placed in a petri dish made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) with a diameter of 50 mm, and allowed to spread evenly. The mixture was then dried at 50°C for one week to obtain a dried ink film. 5.0 mg of the dried ink film was taken and placed in an aluminum sample container, which was then placed on a support unit and set up in an electric furnace.

[0197] Next, under a nitrogen atmosphere, the temperature was increased from 0°C to 150°C at a heating rate of 10°C / min. Then, the temperature was decreased from 150°C to -80°C at a cooling rate of 5°C / min. Finally, the temperature was increased to 150°C again at a heating rate of 10°C / min, and the DSC curve was measured.

[0198] Using the analytical program in the DSC-60 system, the inflection point during the second heating was analyzed by the midpoint method, and the glass transition point (Tg) was determined from the obtained DSC curve.

[0199] The resin content in the drying film of the above-mentioned ink is not particularly limited and can be appropriately selected according to the purpose, preferably 10% by mass or more and 60% by mass or less.

[0200] The above content indicates the content of the solid component of the resin.

[0201] There are no particular restrictions on the content of solid components in the above-mentioned ink, and it can be appropriately selected according to the purpose. From the viewpoint of good drying properties and excellent concealment, it is preferred to be 45% by mass or more, and more preferably 55% by mass or more.

[0202] The solid components are the solid components contained in the ink, such as thickening particles, resin, and pigments.

[0203] There are no particular limitations on the static surface tension of the ink, and it can be appropriately selected according to the purpose. From the viewpoint of ensuring that the ink flows properly on the substrate and shortening the ink drying time, it is preferably 35 mN / m or less at 25°C, and more preferably 30 mN / m or less.

[0204] There are no particular limitations on the pH of the ink, and it can be appropriately selected according to the purpose. From the viewpoint of preventing corrosion of metal parts in contact with the liquid, it is preferably 7 or more and 12 or less, and more preferably 8 or more and 11 or less.

[0205] Ink manufacturing method

[0206] There are no particular limitations on the manufacturing method of the above-mentioned ink, and it can be appropriately selected according to the purpose. For example, it can be obtained by dispersing or dissolving the constituent components in an aqueous medium and then stirring and mixing them as needed.

[0207] The mixing process described above can be performed using, for example, a mixer with stirring blades, a magnetic stirrer, or a high-speed disperser.

[0208] Printing methods and printing equipment

[0209] As used in this specification, the term "inkjet printing equipment" refers to a liquid discharge device that can discharge the ink, processing liquid, etc. of the present invention to the object to be printed.

[0210] Hereinafter, an example of an ejection device for an inkjet printing apparatus will be described with reference to the accompanying drawings. However, this embodiment is not limited to the following embodiments.

[0211] Figure 6 This is a schematic side view showing an example of a liquid discharge device of a printing apparatus according to an embodiment of the present invention. Figure 7 This is a schematic top view showing an example of a liquid discharge device of a printing apparatus according to an embodiment of the present invention.

[0212] The liquid discharge device 1000 is arranged opposite to the printed object 100. The carriage C is equipped with a head 300 for discharging ink, such as liquid, toward the printed object 100. The Z-axis guide rail 103 holds the carriage C so that the carriage C can move in the Z-axis direction.

[0213] X-axis guide rail 101 holds Z-axis guide rail 103 so that Z-axis guide rail 103 holding carriage C can move in the X-axis direction. Furthermore, Y-axis guide rail 102 holds X-axis guide rail 101 so that X-axis guide rail 101 can move in the Y-axis direction. Here, X-axis is an example of a "first axis", Y-axis is an example of a "second axis intersecting the first axis", and Z-axis is an example of a "third axis intersecting the first and second axes". Additionally, carriage C is an example of a "liquid discharge unit", and head 300 is an example of a "liquid discharge head".

[0214] The liquid discharge device 1000 includes a Z-direction actuator 92 that moves the carriage C along the Z-axis guide rail 103 in the Z-axis direction, and an X-direction actuator 72 that moves the Z-axis guide rail 103 along the X-axis guide rail 101 in the X-axis direction. Furthermore, the liquid discharge device 1000 includes a Y-direction actuator 82 that moves the X-axis guide rail 101 along the Y-axis guide rail 102 in the Y-axis direction. The Z-direction actuator 92 is an example of a "first actuator" that moves the carriage C in the Z-axis direction, which intersects the X and Y axes. The movement of the carriage C and the head 300 in the Z-axis direction may not be parallel to the Z-axis direction, as long as it includes at least a Z-axis component; it may also be an oblique movement.

[0215] The carriage C further includes another Z-direction actuator 93. The Z-direction actuator 93 is an example of a "second actuator" that moves the head 300 relative to the carriage C in the Z-axis direction.

[0216] The liquid discharge device 1000, configured as described above, discharges ink from the head 300 to the workpiece 100 while moving the carriage C in the X, Y, and Z directions, thus performing printing on the workpiece 100. The workpiece 100 is represented in the form of a flat plate, but it can also be a surface that is close to vertical or has a large radius of curvature, such as a car, truck, or aircraft.

[0217] Substrate

[0218] The aforementioned substrate (hereinafter sometimes referred to as "the object to be printed") refers to the object to which the ink of the present invention is printed, and refers to the object to which the ink or processing liquid can adhere even temporarily.

[0219] There are no particular restrictions on the aforementioned substrates; they can be selected appropriately according to the purpose, with preferred substrates being those for road surfaces, exterior finishes, and porous materials.

[0220] There are no particular restrictions on the shape, structure, and material of the aforementioned substrates. They can be appropriately selected according to the purpose. For example, substrates that have undergone metal coating treatment by methods such as vapor deposition on wall panels (kiln-made, resin-made, wood-made, metal-made), asphalt, asphalt felt, concrete, glass, cloth, paper, plastic, wood, metal (brass, iron, aluminum, SUS (stainless steel), copper, etc.), or non-metallic substrates can be listed.

[0221] Examples of porous substrates include asphalt, sponges, and other substrates with high ink permeability.

[0222] Example

[0223] The following describes embodiments of the present invention, but the present invention is not limited to these embodiments in any way.

[0224] Manufacturing of Nozzle 1

[0225] The LETTER ROBO head (the head that mounts onto the LETTER ROBO, manufactured by Ricoh Digital Painting) was modified, with a nozzle diameter set to 300μm. Using this modified head, coating was performed via dip coating, as follows: Figure 3 The diagram shows the formation of a fluorine-containing hydrophobic layer with a thickness of 0.01 μm. At this stage, the areas where the fluorine-containing hydrophobic layer does not form are masked with water-soluble resin or tape. After the fluorine-containing hydrophobic layer is formed, the masking material is peeled off. The coating is then applied at 120°C for 1 hour to form the fluorine-containing hydrophobic layer, and nozzle 1 (nozzle diameter: 300 μm) is fabricated. A fluorine-containing layer with a thickness of 0.01 μm is formed on a SUS plate using the same method, and the surface free energy is measured to be 13 mJ / m². 2 .

[0226] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0227] Manufacturing of Nozzle 2

[0228] Besides forming by dip coating, such as Figure 2 Apart from the fluorinated hydrophobic layer with a film thickness of 0.01 μm shown, nozzle 2 (nozzle diameter: 300 μm) is manufactured using the same method as nozzle 1.

[0229] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0230] Manufacturing of Nozzle 3

[0231] Besides forming by dip coating, such as Figure 1Apart from the fluorinated hydrophobic layer with a film thickness of 0.01 μm shown, nozzle 3 (nozzle diameter: 300 μm) is manufactured using the same method as nozzle 1.

[0232] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0233] Manufacturing of Nozzle 4

[0234] Using DOWSIL SR2400 resin (manufactured by Dow Toray), an impregnation method was used to achieve an adhesion concentration of approximately 1 mg / cm². 2 Thus forming Figure 3 The image shows a silicon-containing hydrophobic layer. At this point, areas where the silicon-containing layer has not formed are masked with water-soluble resin or tape. After coating to form the silicon-containing hydrophobic layer, the mask is peeled off. The coating is then heated and cured at 150°C for 2 hours to form the silicon-containing hydrophobic layer, and nozzle 4 (nozzle diameter: 300 μm) is fabricated. An adhesion weight of approximately 1 mg / cm³ is achieved using the same method. 2 The surface free energy of the silicon-containing liquefactive layer was measured and found to be 22 mJ / m. 2 .

[0235] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0236] Manufacturing of Nozzle 5

[0237] In addition to the immersion method at approximately 1 mg / cm 2 Adhesion amount formation such as Figure 2 Apart from the silicon-containing hydrophobic layer shown, nozzle 5 (nozzle diameter: 300 μm) is manufactured using the same method as nozzle 4.

[0238] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0239] Manufacturing of Nozzle 6

[0240] In addition to using the immersion method at approximately 1 mg / cm 2 Adhesion amount formation such as Figure 1 Apart from the silicon-containing hydrophobic layer shown, nozzle 6 (nozzle diameter: 300 μm) is manufactured using the same method as nozzle 4.

[0241] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0242] Manufacturing of Nozzle 7

[0243] Except that the nozzle diameter is 50 μm, the nozzle 7 (nozzle diameter: 50 μm) is manufactured using the same method as the nozzle 1.

[0244] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0245] Manufacturing of Nozzle 8

[0246] Except for the nozzle diameter being 600 μm, nozzle 8 (nozzle diameter: 600 μm) is manufactured using the same method as nozzle 1.

[0247] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0248] Manufacturing of Nozzle 9

[0249] Except for the nozzle diameter being 900 μm, the nozzle 9 (nozzle diameter: 900 μm) is manufactured using the same method as the nozzle 1.

[0250] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0251] Manufacturing of Nozzle 10

[0252] Using KEMITITE CT4112 (manufactured by Kyocera Chemical Co., Ltd.), a precursor of polyimide with polyamic acid as its main component, coating is performed by impregnation to form a product such as... Figure 3 The diagram shows a 0.3 μm thick polyimide-containing hydrophobic layer. At this stage, the portion without a polyimide layer is masked with water-soluble resin, tape, etc. After coating to form the polyimide hydrophobic layer, the masking material is peeled off. The temperature is slowly increased to 110°C and heated for 60 minutes, then heated at 200°C for 20 minutes, and further slowly increased to 360°C and heated for 60 minutes to form the polyimide layer. Nozzle 10 (nozzle diameter: 300 μm) is then fabricated. A 0.3 μm thick polyimide hydrophobic layer is formed on a SUS plate using the same method, and the surface free energy is measured to be 50 mJ / m². 2 .

[0253] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0254] Manufacturing of Nozzle 11

[0255] In addition to Figure 2 Apart from forming the hydrophobic layer, the nozzle 11 (nozzle diameter: 300 μm) is manufactured using the same method as the nozzle 10.

[0256] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0257] Manufacturing of Nozzle 12

[0258] In addition to Figure 1 Except for the formation of the hydrophobic layer shown, the nozzle 12 (nozzle diameter: 300 μm) is manufactured by the same method as the nozzle 10.

[0259] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0260] Manufacturing of Nozzle 13

[0261] A head 13 (nozzle diameter: 300 μm) made of SUS without forming a hydrophobic layer was fabricated. The head consisted of a matrix, nozzle orifice, liquid chamber, and needle valve. The surface free energy of SUS was measured to be 33 mJ / m². 2 .

[0262] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0263] Manufacturing of Nozzle 14

[0264] Production Figure 8 The head 14 of the needle valve (nozzle diameter: 300 μm) is made of SUS and has a matrix, a nozzle orifice, a liquid chamber, and a front end covered with a 200 μm thick perfluoroelastomer.

[0265] The shape of the nozzle, the compounds contained in the hydrophobic layer, the surface free energy of the hydrophobic layer, and the nozzle diameter are shown in Table 1.

[0266] [Table 1]

[0267]

[0268] Preparation of white pigment dispersions

[0269] The mixture of 200 parts by weight of CI pigment white 6 (manufactured by TAYCA, product name "JR-403", number average primary particle size 250nm, aspect ratio 2, surface treatment: Al, Si), 56 parts by weight of pigment dispersant (trade name: TEGO Dispers 651, manufactured by Evonik), and 744 parts by weight of distilled water was premixed.

[0270] Subsequently, using a bead mill disperser (UAM-015, manufactured by Kobe Industries), at a liquid temperature of 30°C, zirconia beads with a diameter of 0.03 mm (density 6.03 × 10⁻⁶) were dispersed at a circumferential speed of 10 m / s, using zirconia beads (density 6.03 × 10⁻⁶).

[0271] 10 -6 g / m 2 Disperse for 15 minutes, then centrifuge using a centrifuge (Model-3600, manufactured by Kubota Corporation) to separate coarse particles, obtaining a white pigment dispersion with an average particle size of 250 nm (solid content of 20.0% by mass).

[0272] Preparation of Cyan Pigment Dispersion

[0273] In an automated polymerization reactor (manufactured by Hōsei Sangyo Co., Ltd., polymerization test machine DSL-2AS type) equipped with a reaction vessel containing a stirring device, a dropping device, a temperature sensor, and a reflux device with a nitrogen introduction device at the top, 550g of butanone is added, and nitrogen is purged into the reaction vessel while stirring.

[0274] Then, while maintaining the reaction vessel under a nitrogen atmosphere, the temperature was raised to 80°C, and a mixed solution of 75.0 g of 2-hydroxyethyl methacrylate, 77.0 g of methacrylic acid, 80.0 g of styrene, 150.0 g of butyl methacrylate, 98.0 g of butyl acrylate, 20.0 g of methyl methacrylate, and 40.0 g of "Perbutyl (registered trademark) O" (manufactured by Nippon Oils & Fats Co., Ltd.) was added dropwise over 4 hours.

[0275] After the addition was complete, the reaction was continued for another 15 hours at the same temperature to obtain a butanone solution of a styrene-acrylic acid copolymer containing anionic groups, with an acid value of 100, a weight-average molecular weight of 21,000, and a calculated Tg of 31°C. After the reaction was completed, a portion of the butanone was removed by vacuum distillation to obtain a copolymer solution with the non-volatile component adjusted to 50%.

[0276] In a mixing tank equipped with a cooling jacket, 1000g of copper phthalocyanine (manufactured by Daihisei Kagaku Co., Ltd., SEIKALIGHT BLUE A612), 800g of the above copolymer solution, 143g of 10% sodium hydroxide aqueous solution, 100g of butanone, and 1957g of water were added and stirred to obtain a mixed solution.

[0277] The resulting mixed solution was dispersed in a dispersion device (Mitsui Mining Co., Ltd., SC mill, SC100) filled with zirconia beads of 0.3 mm in diameter, by circulation (the dispersion from the dispersion device was returned to the mixing tank), at a speed of 2700 rpm, below 40°C (achieved by circulating cold water in the cooling jacket), for 6 hours.

[0278] After dispersion is complete, the original dispersion solution is removed from the mixing tank. Then, the mixing tank and the flow path of the dispersion device are cleaned with 10,000g of water and combined with the original dispersion solution to obtain a diluted dispersion solution.

[0279] The obtained diluted dispersion was placed in a glass distillation apparatus to distill away all the butanone and some of the water. After cooling to room temperature, 10% hydrochloric acid was added dropwise while stirring to adjust the pH to 4.5. Then, the solid components were filtered using a suction filter (a pressure filter manufactured by Nippon Chemical Machinery Co., Ltd.) and washed with water. The filter cake was placed in a container, 200g of a 20% potassium hydroxide aqueous solution was added, and the mixture was dispersed using a disperser (a TK homogenizer manufactured by Special Machinery Chemical Industry Co., Ltd.). Water was then added to adjust the non-volatile components. Thus, a cyan pigment dispersion (pigment content concentration: 20.0% by mass) was obtained, which contained copper phthalocyanine composite particles (pigment content) coated with carboxyl-containing styrene-acrylic copolymer neutralized in potassium hydroxide.

[0280] Preparation of resin emulsion

[0281] A monomer preemulsion was prepared by emulsifying 55.4 parts by weight of methyl methacrylate as monomer, 44.6 parts by weight of 2-ethylhexyl acrylate, 1.5 parts by weight of Aqualon KH-20 (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) as emulsifier, and 53.1 parts by weight of deionized water using an intermittent homogenizer.

[0282] Add 89.4 parts by mass of ion-exchange water to a 2L four-necked flask equipped with a stirrer, nitrogen inlet pipe, reflux condenser, thermometer, and raw material inlet. While introducing nitrogen gas, stir and heat the liquid to 60°C.

[0283] Add 0.5 parts by mass of Aqualon KH-20 as an emulsifier and 6 parts by mass of 5% ammonium persulfate aqueous solution (0.3 parts by mass of ammonium persulfate) to the above reaction vessel.

[0284] Then, after adding a 5% ammonium persulfate aqueous solution to the above reaction vessel for 10 minutes, the above monomer pre-emulsion was continuously added dropwise from the dropping tank for 5 hours, and 6 parts of the 5% ammonium persulfate aqueous solution (0.3 parts as ammonium persulfate) were intermittently added dropwise from another dropping tank at 70°C for 5 hours.

[0285] After the addition is complete, maintain the temperature at 70°C for 3 hours to allow it to mature.

[0286] Then, cool to 50°C, add ammonia, and filter with 180-mesh polyester filter cloth to obtain resin emulsion A.

[0287] A portion of the obtained resin emulsion A was dried at 150°C for 30 minutes, and the solid content was determined according to JIS K5601-1-2, with a result of 50.0%. Additionally, the glass transition temperature of resin emulsion A was determined by the following method, and the result was 0°C.

[0288] Determination of the glass transition temperature (Tg) of resin emulsion

[0289] Specifically, 4g of resin emulsion was placed in a petri dish made of tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) with a diameter of 50 mm, and allowed to spread evenly. The mixture was then dried at 50°C for one week to obtain a resin film. 5.0 mg of the obtained resin film was placed in an aluminum sample container, which was then placed on a support unit and set up in an electric furnace.

[0290] Next, under a nitrogen atmosphere, the temperature was increased from 0°C to 150°C at a heating rate of 10°C / min. Then, the temperature was decreased from 150°C to -80°C at a cooling rate of 5°C / min. Finally, the temperature was increased to 150°C again at a heating rate of 10°C / min, and the DSC curve was measured.

[0291] Using the analytical program in the DSC-60 system, the inflection point during the second heating was analyzed by the midpoint method, and the glass transition point (Tg) was determined from the obtained DSC curve.

[0292] Preparation of Ink 1

[0293] 5.0% by mass of propylene glycol as a solvent, 9.0% by mass of deionized water, 30.0% by mass of the above-mentioned resin emulsion A as a resin, and 20.0% by mass of white pigment dispersion as a colorant were mixed and stirred for 30 minutes to make it homogeneous. Then, 36.0% by mass of calcium carbonate (UP-G, manufactured by Imerys Japan) as a thickening particle was added, and the mixture was stirred at high speed for 1 hour to make it homogeneous, thus obtaining ink 1.

[0294] Preparation of Ink 2

[0295] 5.0% by mass of propylene glycol as a solvent, 2.0% by mass of deionized water, 33.0% by mass of the above-mentioned resin emulsion A as a resin, and 20.0% by mass of white pigment dispersion as a colorant were mixed and stirred for 30 minutes to make it homogeneous. Then, 40.0% by mass of calcium carbonate (UP-G, manufactured by Imerys Japan) as a thickening particle was added, and the mixture was stirred at high speed for 1 hour to make it homogeneous, thus obtaining ink 2.

[0296] Preparation of Ink 3

[0297] 5.0% by mass of propylene glycol as a solvent, 20.0% by mass of deionized water, 35.0% by mass of the above-mentioned resin emulsion A as a resin, and 20.0% by mass of white pigment dispersion as a colorant were mixed and stirred for 30 minutes to make it homogeneous. Then, 20.0% by mass of calcium carbonate (UP-G, manufactured by Imerys Japan) as a thickening particle was added, and the mixture was stirred at high speed for 1 hour to make it homogeneous, thus obtaining ink 3.

[0298] Preparation of Ink 4

[0299] 14.0% by mass of ion-exchanged water as solvent, 30.0% by mass of the above-mentioned resin emulsion A as resin, and 20.0% by mass of white pigment dispersion as colorant were mixed and stirred for 30 minutes to make it homogeneous. Then, 36.0% by mass of calcium carbonate (UP-G, manufactured by Imerys Japan) as thickening particles were added, and the mixture was stirred at high speed for 1 hour to make it homogeneous, thus obtaining ink 4.

[0300] Preparation of Ink 5

[0301] 4.0% by mass of propylene glycol as a solvent, 10.0% by mass of deionized water, 30.0% by mass of the above-mentioned resin emulsion A as a resin, and 20.0% by mass of cyan pigment dispersion as a colorant were mixed and stirred for 30 minutes to make it homogeneous. Then, 36.0% by mass of calcium carbonate (UP-G, manufactured by Imerys Japan) as a thickening particle was added, and the mixture was stirred at high speed for 1 hour to make it homogeneous, thus obtaining ink 5.

[0302] Ink viscosity

[0303] For ink viscosity, using an MCR301 (Anton Parr) cone plate (cone radius: 25 mm, cone angle: 1°), the shear rate was measured to be 1 second. -1 The viscosity (mPa·s) at 25℃ and the shear rate are 5000 s. -1 The viscosity (mPa·s) at 25℃ and the shear rate are 0.1 s. -1Viscosity (mPa·s) at 25°C. The viscosities of inks 1 to 5 are shown in Table 1. The units of the numbers in Table 1 for the compositions are "mass%".

[0304] [Table 2]

[0305]

[0306] Example 1

[0307] For the combination of nozzle 1 and ink 1, the "discharge stability after opening the cap" was evaluated. The results are shown in Table 2.

[0308] Discharge stability after opening

[0309] Ink was placed in various heads, and after an initial ink ejection of 3 minutes, the ink was exposed to the atmosphere for 10 minutes and 20 minutes without covering the nozzle. Then, ejection was evaluated again for 3 minutes, and ejection stability was assessed according to the following evaluation criteria. An evaluation result with ejection stability of "C" or higher is within the practical range.

[0310] Evaluation Criteria

[0311] A: It will not bend or shake during discharge and can be discharged stably.

[0312] B: Although there may be slight bending or shaking during discharge, it can be discharged stably.

[0313] C: Sometimes bending or shaking may occur during discharge, but the degree of bending or shaking is within the allowable range.

[0314] D: Sometimes the discharge may bend or shake, and it may not be able to be discharged stably or at all.

[0315] Examples 2-13 and Comparative Examples 1-5

[0316] The "discharge stability after opening" of the embodiments and comparative examples was evaluated using the nozzle and ink combinations described in Table 2. The results are shown in Table 3.

[0317] [Table 3]

[0318]

[0319] For example, aspects of the present invention are described below:

[0320] Aspect 1

[0321] According to aspect 1, a liquid discharge device is provided, comprising a nozzle unit for discharging a high-viscosity liquid.

[0322] The nozzle unit includes: a nozzle orifice; a nozzle plate having the nozzle orifice; a liquid chamber for supplying liquid to the nozzle orifice; a needle valve having a front end that moves in and out of the liquid chamber to close or open the nozzle orifice; and a hydrophobic layer on the surface of the nozzle plate, the hydrophobic layer having a concentration of less than 29 mJ / m 2 Surface free energy.

[0323] Aspect 2

[0324] According to aspect 2, the liquid discharge device of aspect 1 further includes a hydrophobic layer located on the outer surface of the nozzle plate and on the surface of the nozzle orifice forming the nozzle orifice.

[0325] Aspect 3

[0326] According to aspect 3, the liquid discharge device of aspect 1 or aspect 2 further includes a hydrophobic layer located on the inner surface of the nozzle plate.

[0327] Aspect 4

[0328] According to aspect 4, the liquid discharge device of any of aspects 1 to 3 further includes a liquid-repellent layer at the front end of the needle valve.

[0329] Aspect 5

[0330] According to aspect 5, in the liquid discharge device of any of aspects 1 to 4, the liquid-repellent layer comprises at least one of silicon (Si) or fluorine (F).

[0331] Aspect 6

[0332] According to aspect 6, in the liquid discharge device of aspect 5, the liquefaction layer comprises at least one of a fluorinated modified hydrocarbon or an organosilicon compound.

[0333] Aspect 7

[0334] According to aspect 7, in the liquid discharge device of aspect 5, the liquid-repellent layer comprises a fluorinated hydrocarbon, the fluorinated hydrocarbon comprising condensed and bonded silanol groups.

[0335] Aspect 8

[0336] According to aspect 8, in the liquid discharge device of aspect 5, the liquefaction layer comprises a siloxane polymer having: siloxane bonds as the main chain; and organic groups as side chains.

[0337] Aspect 9

[0338] According to aspect 9, in any of aspects 1 to 8 of the liquid discharge device, the diameter of the nozzle orifice is 50 μm or more.

[0339] Aspect 10

[0340] According to aspect 10, a printing apparatus includes a discharge mechanism that discharges liquid from a liquid discharge device of any one of aspects 1 to 9.

[0341] Aspect 11

[0342] According to aspect 11, in the printing apparatus of aspect 10, the solid content of the liquid is 45% by mass or more.

[0343] Aspect 12

[0344] According to aspect 12, in the printing apparatus of aspect 10 or aspect 11, the liquid includes ink or coating.

[0345] Aspect 13

[0346] According to aspect 13, a printing method includes a discharge step, in which a high-viscosity liquid is discharged from a liquid discharge device of any of aspects 1 to 9.

[0347] The above embodiments are illustrative and do not limit the invention. Therefore, many additional modifications and variations are possible based on the above teachings. For example, within the scope of the invention, components and / or features of different illustrative embodiments may be combined with and / or substituted for each other. Any of the above operations may be performed in various other ways, for example, in an order different from that described above.

[0348] This patent application is based on and claims priority to Japanese Patent Application No. 2023-203108, filed with the Japan Patent Office on November 30, 2023, the entire disclosure of which is incorporated herein by reference.

[0349] List of reference numerals

[0350] 1. Matrix

[0351] 2 Nozzle orifice

[0352] 3 Nozzle Plate

[0353] 4 liquid chambers

[0354] 5 needle valves

[0355] 6. Liquid-repellent layer

[0356] 7. Elastomer diaphragm

[0357] 8. Movable iron core

[0358] 9. Storage space for drive mechanism

[0359] 10. Spring Material

[0360] 11. Fixed iron core

[0361] 12 Electromagnetic solenoid

[0362] 13. Pressurization pathway

[0363] 14. Springs to prevent screws from loosening

[0364] 15 Clearance Adjustment Bolt

[0365] 16 nuts

[0366] 17 Ink Cans

[0367] 18 pumps

[0368] 20. Loop Path

[0369] 21 Ink Output Channels

[0370] C carriage

[0371] 72 X-direction drive

[0372] 82 Y-direction driver

[0373] 92 Z-direction driver

[0374] 93 Z-direction driver

[0375] 100 Printed Objects

[0376] 101 X-axis guide rail

[0377] 102 Y-axis guide rail

[0378] 103 Z-axis guide rail

[0379] 300 heads

[0380] 1000 Liquid Discharge Device

[0381] Citation List

[0382] Patent documents

[0383] [PTL 1] Japanese Unexamined Patent Application Publication No. 2022-64482

Claims

1. A liquid discharge device, comprising: The nozzle plate has nozzle holes for discharging liquid; The liquid chamber supplies the liquid to the nozzle orifice; A needle valve having a front end that moves in and out of the liquid chamber, closing or opening the nozzle orifice using the front end; and A hydrophobic layer on the surface of the nozzle plate, the hydrophobic layer having a concentration of less than 29 mJ / m 2 Surface free energy.

2. The liquid discharge device according to claim 1, in, The hydrophobic layer is located at: The outer surface of the nozzle plate; and The nozzle orifice surface.

3. The liquid discharge device according to claim 1 or 2, in, The hydrophobic layer is further located on the inner surface of the nozzle plate.

4. The liquid discharge device according to claim 1 or 2, in, The needle valve has another hydrophobic layer at its front end.

5. The liquid discharge device according to claim 1 or 2, in, The hydrophobic layer includes at least one of silicon (Si) or fluorine (F).

6. The liquid discharge device according to claim 5, in, The hydrophobic layer includes at least one of fluorinated modified hydrocarbons or organosilicon compounds.

7. The liquid discharge device according to claim 5, in, The liquefying layer comprises a fluorinated hydrocarbon, which includes condensed and bonded silanol groups.

8. The liquid discharge device according to claim 5, in, The hydrophobic layer comprises a siloxane polymer, the siloxane polymer having: As the siloxane bond in the main chain; and Organic groups as side chains.

9. The liquid discharge device according to claim 1 or 2, in, The diameter of the nozzle orifice is 50 μm or more.

10. A printing apparatus comprising a liquid discharge device according to claim 1 or 2 for discharging the liquid into a medium.

11. The printing equipment according to claim 10, in, The solid content of the liquid is 45% by mass or more.

12. The printing equipment according to claim 10, in, The liquid includes ink or paint.

13. A printing method, comprising: Liquid is discharged from the liquid discharge device according to claim 1 or 2.

Images