Nozzle plate and inkjet head

Abstract

The objective of this invention is to provide an inkjet head with excellent ink resistance and abrasion durability. The inkjet head of this invention is a nozzle plate having at least a base layer and a liquid-repellent layer on a substrate, characterized in that a substrate bonding layer is provided between the substrate and the base layer, the concentration (atomic %) of Cr on the surface of the substrate bonding layer is higher than that on the surface of the substrate, the base layer is a layer containing at least an inorganic oxide or a carbon (C)-containing oxide, and the liquid-repellent layer is a layer formed using a coupling agent containing fluorine (F).

Description

Technical Field

[0001] This invention relates to a nozzle plate and an inkjet head. More specifically, it relates to a nozzle plate having excellent inter-component sealing, ink resistance, and abrasion resistance, and an inkjet head having the nozzle plate. Background Technology

[0002] Currently, widely used inkjet recording devices hold an inkjet head, which has an inkjet plate with multiple nozzle holes arranged in a row, on a frame or the like. The ink of various colors is ejected from each of the multiple nozzles toward the recording medium in the form of tiny droplets, thereby forming an image on the recording medium.

[0003] Representative ink ejection methods for inkjet heads include: a method that uses heat generated by the flow of current through a resistive element in a pressure chamber to vaporize and expand water in the ink, thereby applying pressure to the ink and ejecting it; and a method that uses a piezoelectric element as part of the flow path component constituting the pressure chamber, or provides a piezoelectric element in the flow path component, selectively driving piezoelectric elements corresponding to multiple nozzle orifices, thereby deforming the pressure chamber based on the dynamic pressure of each piezoelectric element and ejecting liquid from the nozzle.

[0004] In inkjet heads, the surface characteristics of the surface where the nozzles are located become very important in achieving good ink droplet ejection performance.

[0005] If ink or debris adheres to the vicinity of the inkjet head's nozzle orifice, it can cause problems such as the ejection direction of the ink droplets becoming distorted, the ejection angle of the ink droplets in the nozzle orifice increasing, and the formation of adhering debris.

[0006] To ensure stable ink droplet ejection, optimizing the design of the ink flow path and the method of applying ink pressure is certainly necessary, but this alone is insufficient. It is also crucial to maintain a stable surface condition around the nozzle orifice from which the ink is ejected. Therefore, methods are being investigated to impart a liquid-repellent layer to the periphery of the nozzle orifice on the ink ejection surface of the nozzle plate in a manner that prevents unwanted ink from adhering or remaining.

[0007] Typically, organosilicon compounds or fluorine-containing organic compounds, such as silane coupling agents, are used in the liquid-repellent layer formed on the nozzle surface of the nozzle plate of an inkjet head.

[0008] It is known that a liquid-repellent layer with excellent adhesion can be formed by using a silane coupling agent in the formation of the liquid-repellent layer. However, when the density of hydroxyl groups in the substrate and base layer constituting the nozzle plate is low, the alkaline components constituting the ink can disrupt the hydrogen bonds and hydroxyl bonds present therein, severing the bond, thus resulting in a liquid-repellent layer with low alkali resistance.

[0009] To address the aforementioned problems, a method for manufacturing a highly alkali-resistant liquid-repellent layer has been disclosed as a method for forming such a layer: In the same layer, a silane coupling agent having reactive functional groups at both ends and having a hydrocarbon chain and a benzene ring in the middle, and a fluorinated silane coupling agent are mixed with a silane coupling agent having a fluorinated carbon chain at one end and a reactive functional group at the other end, and a high-density polymer film is formed by a dehydration condensation reaction, thereby creating a hydrophobic benzene ring, alkyl chain, and fluorocarbon chain near the siloxane bond that becomes the crosslinking point (for example, see Patent Document 1).

[0010] However, in the configuration proposed in Patent Document 1, the ink's durability against alkaline components is still insufficient. Furthermore, when using pigment ink, due to the wear of the wiping material used during maintenance and the pigment ink containing pigment particles, it is confirmed that the liquid-repellent layer gradually wears down. It is evident that due to repeated operations over a long period of time, there is a problem that durability (wear durability) cannot be guaranteed by maintenance alone.

[0011] In addition, a nozzle plate with the following configuration is disclosed: the nozzle substrate is made of stainless steel, and on the surface side where the liquid-repellent layer is formed, there is a surface portion where the concentration of chromium (hereinafter referred to as "Cr") is higher than the concentration of Cr in the stainless steel material itself, the ratio of the concentration (atomic%) of Cr to Fe in the surface portion (Cr / Fe) is 0.8 or more, the liquid-repellent layer is a carbon-containing layer, and the liquid-repellent layer is formed directly on the stainless steel material (for example, see Patent Document 2).

[0012] According to the invention described in Patent Document 2, it is believed that the adhesion between the nozzle substrate and the liquid-repellent layer is improved without increasing the manufacturing process.

[0013] However, the liquid-repellent layer area is formed by abrading the nozzle substrate surface with an abrasive to remove surface Fe and increase Cr concentration, resulting in direct contact between the liquid-repellent layer and the nozzle substrate. In nozzle plates with this configuration, it has been found that insufficient alkali resistance occurs after prolonged use with inks with high interfacial permeability, such as alkaline inks, especially inside the nozzle orifice where air and ink come into contact, such as at the interface between the stainless steel substrate and the liquid-repellent layer, where peeling occurs. Furthermore, when using pigment inks, it has been confirmed that the liquid-repellent layer gradually wears down due to the abrasion caused by the wiping material used during maintenance and the pigment ink containing pigment particles. Due to repeated operations over a long period, there is a problem that durability (wear durability) cannot be guaranteed by maintenance alone.

[0014] Existing technical documents

[0015] Patent documents

[0016] Patent Document 1: Japanese Patent No. 4088544

[0017] Patent Document 2: Japanese Patent No. 6119152 Summary of the Invention

[0018] The problem that the invention aims to solve

[0019] The present invention was made in view of the above-mentioned problems and conditions, and its solution is to provide a nozzle plate with excellent sealing between constituent components, ink resistance and wear resistance, and an inkjet head having the nozzle plate.

[0020] Methods for solving problems

[0021] In view of the above-mentioned problems, the inventors conducted in-depth research and found that: a nozzle plate having at least a base layer and a liquid-repellent layer on a substrate, a substrate bonding layer between the substrate and the base layer, a higher Cr concentration on the surface of the substrate bonding layer than on the surface of the substrate, a base layer containing at least an inorganic oxide or a carbon (C) oxide, and a liquid-repellent layer formed using a coupling agent containing fluorine (F), can achieve excellent sealing between constituent components, ink resistance, and wear durability, thus completing the present invention.

[0022] That is, the above-mentioned problems involved in this invention are solved by the following means.

[0023] 1. A nozzle plate having at least a base layer and a liquid-repellent layer on a substrate, characterized in that,

[0024] A substrate bonding layer is provided between the aforementioned substrate and the base layer.

[0025] The Cr concentration (atomic %) on the surface of the aforementioned substrate adhesive layer is higher than that on the surface of the aforementioned substrate.

[0026] The aforementioned substrate layer is a layer containing at least inorganic oxides or carbon (C)-containing oxides, and

[0027] The liquid-repellent layer described above is formed using a coupling agent containing fluorine (F).

[0028] 2. The nozzle plate according to claim 1, characterized in that the content of trivalent Cr at the surface portion of the substrate adhesive layer is 50 atomic% or more relative to the total Cr content.

[0029] 3. The nozzle plate according to claim 1 or 2, characterized in that, in the concentration (atomic %) ratio of the constituent elements at the surface portion of the substrate adhesive layer, the ratio of the concentration (atomic %) of Cr to Fe (Cr / Fe) is 0.8 or more.

[0030] 4. The nozzle plate according to any one of items 1 to 3, characterized in that the thickness of the substrate adhesive layer is in the range of 1 to 50 nm.

[0031] 5. The nozzle plate according to any one of claims 1 to 4, characterized in that the substrate layer contains an oxide composed of at least carbon (C), silicon (Si), and oxygen (O) as the carbon (C)-containing oxide.

[0032] 6. The nozzle plate according to any one of claims 1 to 5, characterized in that the substrate layer is a layer containing a silane coupling agent as the carbon (C) oxide.

[0033] 7. The nozzle plate according to claim 6, characterized in that the silane coupling agent contained in the substrate layer has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle.

[0034] 8. The nozzle plate according to any one of items 1 to 7, characterized in that the substrate is stainless steel.

[0035] 9. An inkjet head, characterized in that it comprises a nozzle plate according to any one of claims 1 to 8.

[0036] The effects of the invention

[0037] According to the present invention, nozzle plates and the like with excellent inter-component sealing, ink resistance and wear durability can be provided.

[0038] The mechanism of action or manifestation of the effects of this invention is speculated as follows.

[0039] In this invention, the substrate is characterized by having a substrate bonding layer between the substrate and the base layer, wherein the concentration (atomic %) of Cr in the substrate bonding layer is higher than that in the substrate, the base layer is a layer containing at least an inorganic oxide or a carbon (C) oxide, and the liquid repellent layer is a layer formed using a coupling agent containing fluorine (F).

[0040] Figure 1 This illustrates an example of the configuration of the nozzle orifice in a conventional nozzle plate.

[0041] Figure 1 The nozzle plate 1 described herein has a base layer 4 and a liquid-repellent layer 5 as the outermost layer on a substrate 2. In this nozzle plate 1, a through nozzle orifice N is formed. It has been determined that when ink In is filled into this nozzle orifice N, for example, when the ink In is alkaline ink, the following problem occurs: the ink In present on the inner surface of the nozzle orifice particularly erodes the interface between the substrate 2 and the base layer 4, causing peeling at this interface. This becomes a major cause of significant damage to the durability (ink resistance) of the nozzle plate.

[0042] The inventors conducted in-depth research on the above-mentioned problems and found that: Figure 2 As shown, by providing a substrate bonding layer 3 with Cr as the main component between the substrate 2 and the base layer 4, which contains at least inorganic oxides or carbon (C) oxides, ink penetration into the interface between the substrate and the base layer can be prevented even during long-term printing using alkaline inks, thus preventing peeling between the substrate and the base layer. Furthermore, by setting the content of trivalent Cr relative to the total Cr content of the surface portion of the substrate bonding layer to 50 atomic% or more, wear durability can be significantly improved.

[0043] Furthermore, it was discovered that by setting the concentration ratio (atomic percentage) of the constituent elements of the surface portion of the substrate adhesive layer to 0.8 or higher (Cr / Fe), the aforementioned alkali resistance to ink can be improved.

[0044] Furthermore, the base layer constituting the nozzle plate is characterized by being an oxide-containing layer. More preferably, the base layer contains at least an inorganic oxide or a carbon (C)-containing oxide, and preferably contains a silane coupling agent. More preferably, the silane coupling agent, which has reactive functional groups at both ends and contains hydrocarbon chains and benzene rings in the middle, is polymerized at high density and interacts with each other through stacking. This improves the adhesion between the nozzle plate substrate and the constituent layers disposed thereon when the nozzle plate is subjected to stress, particularly in the thickness direction. This improves the adhesion and enhances the resistance of the nozzle plate surface to lateral stress during maintenance due to wiping materials or the like. It has also been found that by having a base layer including an intermediate layer, the coupling agent in the liquid-repellent layer can be efficiently oriented on the surface and densely filled in the plane, achieving excellent liquid repellency and ensuring alkali resistance and durability due to long-term repeated maintenance using pigment inks. Attached Figure Description

[0045] Figure 1 This is a schematic cross-sectional view showing an example of the structure of the nozzle orifice portion of the nozzle plate in a comparative example.

[0046] Figure 2 This is a schematic cross-sectional view showing an example of the structure of the nozzle orifice portion of the nozzle plate of the present invention.

[0047] Figure 3 This is a schematic cross-sectional view illustrating an example of the structure of the nozzle plate of the present invention.

[0048] Figure 4 This is a schematic cross-sectional view showing another example of the structure of the nozzle plate of the present invention.

[0049] Figure 5This is a coordinate graph representing an example of the distribution of the various valences of Cr in the substrate adhesive layer.

[0050] Figure 6 This is a coordinate graph representing an example of the atomic concentration distribution curves (depth distribution) along the thickness direction of the substrate and the substrate adhesive layer.

[0051] Figure 7 This is a schematic diagram illustrating an example of a high-frequency plasma apparatus in RIE mode used to form a substrate adhesive layer.

[0052] Figure 8 This is a schematic diagram illustrating an example of a high-frequency plasma apparatus used to form a PE mode adhesive layer on a substrate.

[0053] Figure 9 This is a schematic perspective view showing an example of the structure of an inkjet head to which the nozzle plate of the present invention can be applied.

[0054] Figure 10 It indicates composition Figure 9 A bottom view of an example of the nozzle plate of an inkjet head. Detailed Implementation

[0055] The nozzle plate of the present invention is a nozzle plate having at least a base layer and a liquid-repellent layer on a substrate. Its characteristic feature is that a substrate bonding layer is provided between the substrate and the base layer, the concentration (atomic %) of Cr on the surface portion of the substrate bonding layer is higher than that on the surface portion of the substrate, the base layer is a layer containing at least an inorganic oxide or a carbon (C)-containing oxide, and the liquid-repellent layer is a layer formed using a coupling agent containing fluorine (F). This feature is a common technical feature of the inventions involved in the following embodiments.

[0056] As an embodiment of the present invention, from the viewpoint of further demonstrating the target effect of the present invention, the content of trivalent Cr (Cr(III)) on the surface of the above-mentioned substrate adhesive layer is 50 atomic% or more relative to the total Cr content, which is preferred from the viewpoint of further improving the wear durability, which is the target effect of the present invention.

[0057] Furthermore, in terms of the concentration (atomic%) ratio of the constituent elements on the surface of the substrate adhesive layer, the ratio of the concentration (atomic%) of Cr to Fe (Cr / Fe) is 0.8 or higher. This prevents ink from penetrating into the interface between the substrate and the base layer, even when printing for a long time using alkaline inks, and further prevents peeling between the substrate and the base layer. From this perspective, it is preferable.

[0058] Furthermore, considering the ability to further improve the alkali resistance of the inner surface of the nozzle orifice of the nozzle plate, which is the target effect of the present invention, it is preferable to make the thickness of the substrate bonding layer in the range of 1 to 50 nm.

[0059] Furthermore, considering the effect of maintaining the coupling agent containing fluorine (F) in the liquid-repellent layer as the upper layer and further improving the adhesion between the liquid-repellent layer and the intermediate layer, it is preferable that the base layer contains an oxide composed of at least carbon (C), silicon (Si), and oxygen (O) as the aforementioned carbon (C)-containing oxide.

[0060] Furthermore, considering the improved adhesion to the substrate, especially the metal substrate, and the improved adhesion between the substrate of the nozzle plate and the constituent layers disposed thereon when the nozzle plate is subjected to stress, especially stress in the thickness direction, thus improving the adhesion and the wear durability of the nozzle plate surface when subjected to lateral stress due to wiping materials used during maintenance, it is preferable that the base layer is a layer containing a silane coupling agent. More preferably, the silane coupling agent has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle.

[0061] In addition, stainless steel is preferred as the base material, considering its superior durability.

[0062] The present invention and its constituent elements, as well as the forms and methods for carrying out the present invention, will be described in detail below. It should be noted that in this application, the term "~" indicating a numerical range is used to include the numerical values ​​described before and after it as the lower limit and the upper limit.

[0063] Nozzle Plate

[0064] The nozzle plate of the present invention is a nozzle plate having at least a base layer and a liquid-repellent layer on a substrate, characterized in that a substrate bonding layer is provided between the substrate and the base layer, the concentration (atomic %) of Cr on the surface of the substrate bonding layer is higher than that on the surface of the substrate, the base layer is a layer containing at least an inorganic oxide or a carbon (C) oxide, and the liquid-repellent layer is a layer formed using a coupling agent containing fluorine (F).

[0065] The nozzle plate of the present invention will be described in detail below.

[0066] [Basic Structure of a Nozzle Plate]

[0067] First, the basic structure of the nozzle plate of the present invention will be described with reference to the accompanying drawings. It should be noted that in the description of the figures, the numbers listed at the end of the constituent elements indicate the reference numerals in the figures.

[0068] Figure 3 This is a schematic cross-sectional view showing an example of a nozzle plate having the configuration specified in this invention.

[0069] like Figure 3As shown, the basic configuration of the nozzle plate 1 of the present invention is as follows: a substrate bonding layer 3 with a Cr concentration (atomic %) higher than that of the substrate is formed on the substrate 2, a base layer 4 having at least an inorganic oxide or a carbon (C) oxide thereon, and a liquid repellent layer 5 having a coupling agent containing fluorine (F) on the outermost layer.

[0070] Figure 4 This is a schematic cross-sectional view showing an example of another configuration of the nozzle plate involved in the present invention.

[0071] Figure 4 The nozzle plate 1 shown is relative to Figure 3 The nozzle plate shown is configured such that the base layer 4 disposed between the substrate sealing layer 3 and the liquid repellent layer 5 is configured as a base layer unit 4U consisting of two layers: a first base layer 6 and a second base layer 7. For example, the first base layer 6 is configured to contain a silane coupling agent (hereinafter also referred to as silane coupling agent A) having reactive functional groups at both ends and containing a hydrocarbon chain and a benzene ring in the middle. The second base layer 7 can be configured to be an organic oxide containing silicon (Si), such as a low molecular weight silane compound or a silane coupling agent.

[0072] [Materials that make up the nozzle plate]

[0073] Next, the details of the substrate 2, substrate sealing layer 3, base layer 4, liquid repellent layer 5, etc. constituting the nozzle plate of the present invention will be described.

[0074] In this invention, the substrate is characterized by having a substrate bonding layer between the substrate and the base layer, wherein the concentration (atomic %) of Cr on the surface of the substrate bonding layer is higher than that on the surface of the substrate, the base layer is a layer containing at least an inorganic oxide or a carbon (C) oxide, and the liquid repellent layer is a layer formed using a coupling agent containing fluorine (F).

[0075] In this invention, the surface portion of the substrate refers to the region from the outermost surface to a depth of 5 nm on the side in contact with the substrate adhesive layer. Furthermore, the surface portion of the substrate adhesive layer refers to the surface opposite to the side in contact with the substrate, and its surface portion generally refers to the region from the outermost surface of the substrate adhesive layer in the substrate direction to a depth of 5 nm.

[0076] [Substrate]

[0077] The substrate 2 constituting the nozzle plate 1 can be selected from materials with high mechanical strength, ink resistance, and excellent dimensional stability. For example, various materials such as inorganic materials, metal materials, and resin films can be used. Among them, inorganic materials and metal materials are preferred, and iron (e.g., stainless steel (SUS)), aluminum, nickel, stainless steel and other metal materials are more preferred. Stainless steel (SUS) is particularly preferred.

[0078] There is no particular limitation on the thickness of the substrate constituting the nozzle plate, which is in the range of 10 to 500 μm, preferably in the range of 30 to 150 μm.

[0079] [Substrate Adhesive Layer]

[0080] (Composition of the substrate adhesive layer)

[0081] In this invention, the surface portion of the substrate adhesive layer formed between the substrate and the base layer described later is characterized in that the Cr concentration is higher than that of the surface portion of the substrate.

[0082] In the nozzle plate of the present invention, as described above, stainless steel (SUS) is preferably used as the substrate. For example, the composition of SUS304, a representative stainless steel, is as follows: Fe 71 atomic%, Cr 18 atomic%, Ni 8.5 atomic%, and the remainder being other elements. Regarding the surface of the stainless steel substrate in contact with air, carbon and oxygen are present due to oxidation caused by air and trace amounts of adsorption of organic matter. If an XPS-based elemental analysis is performed (described later), the elemental composition, as an example, is C: 31 atomic%, O: 47 atomic%, Cr: 9.8 atomic%, Fe: 7.5 atomic%, and others. When SUS304 is used as the substrate, the Cr content on its surface is 9.8 atomic%.

[0083] In the substrate adhesive layer of the present invention, at least Cr is contained. As for its Cr content, it is preferred that the content of trivalent Cr at the surface portion of the substrate adhesive layer is 50 atomic% or more relative to the total Cr content.

[0084] As described above, the surface portion of the substrate adhesive layer is the side opposite to the side that contacts the substrate, and its surface portion generally refers to the region extending to a depth of 5 nm in the substrate direction from the outermost surface of the substrate adhesive layer.

[0085] Furthermore, in the substrate adhesive layer of the present invention, it is preferable that the ratio of the atomic concentration ratio (atomic %) of Cr to Fe (atomic %) of the constituent elements of the surface portion specified above is 0.8 or more.

[0086] (Specific compositional analysis methods for the substrate adhesive layer)

[0087] The following provides a detailed description of the various characteristic values ​​of the substrate adhesive layer involved in this invention and their specific measurement methods.

[0088] <Determination of the composition ratio of the constituent elements of the substrate adhesive layer>

[0089] In this invention, the method for determining the composition ratio of elements constituting the substrate adhesive layer is not particularly limited. For example, methods can be used such as cutting a 10 nm region from the surface of the substrate adhesive layer using a glass cutter or similar tool to quantitatively analyze the composition of the material constituting that section; or scanning the mass of the compound in the thickness direction of the substrate adhesive layer using infrared spectroscopy (IR), atomic absorption spectrometry, or similar methods; furthermore, even if the substrate adhesive layer is an extremely thin film of 10 nm or less, quantification can be performed using XPS (X-ray Photoelectron Spectroscopy). From the viewpoint that elemental analysis can be performed even on extremely thin films, and that the compositional distribution profile in the thickness direction of the entire substrate adhesive layer can be determined using depth profile measurement (described later), XPS analysis is a preferred method. It should be noted that a detailed description of X-ray photoelectron spectroscopy (XPS analysis) will be provided later.

[0090] <Analytical Method 1: Determination of the content of trivalent Cr on the surface of the substrate adhesive layer>

[0091] The method for determining the content of trivalent Cr on the surface of the substrate adhesive layer of the present invention will be described.

[0092] In the substrate adhesive layer of the present invention, the content of trivalent Cr in the surface portion relative to the total Cr content is preferably 50 atomic% or more, and the content of trivalent Cr can be determined according to the method described below.

[0093] In this invention, in order to determine the content of 0-valent (metallic element, Cr(0)), 3-valent (Cr(III), for example Cr2O3) and 6-valent (Cr(VI), for example CrO3) valences of Cr on the surface of the substrate adhesive layer, X-ray photoelectron spectroscopy is preferably used.

[0094] X-ray photoelectron spectroscopy (XPS) or ESCA (Electron Spectroscopy for Chemical Analysis) is a type of photoelectron spectroscopy used to analyze the constituent elements and their electronic states present on the surface of a sample, from the sample surface to a depth of 5 nm.

[0095] The following is an example of specific conditions under which XPS analysis can be applied to the present invention.

[0096] • Analytical apparatus: QUANTERA SXM manufactured by ULVAC-PHI

[0097] • X-ray source: Monochromatic Al-Kα 15kV 25W

[0098] • Energy: 55eV

[0099] • Data processing: Using MultiPak manufactured by ULVAC-PHI

[0100] • Elemental composition analysis: The Shirley method was used for background processing, and the elemental composition was quantified using the relative sensitivity coefficient based on the obtained peak area.

[0101] Cr valence state analysis: Based on the correction of peak shift caused by charging using the bond energy of the carbon 1s peak, peak separation of 0, 3, and 6 valence states of chromium was performed on the Cr2p3 / 2 peak. The bond energies of each state are 574.3 eV for 0 valence, 576.0 eV for 3 valence, and 578.9 eV for 6 valence. These values ​​were used as peaks, and fitting was performed under the condition that the peak FWHM (full width at half maximum) is within the range of 1.2 to 2.8. The proportions of 0, 3, and 6 valence states of chromium were determined from the area ratio of each peak.

[0102] The above method is used to determine the content of trivalent Cr in the surface portion (depth 5nm) of a sample without a base layer and a liquid-repellent layer. For samples with a base layer and a liquid-repellent layer, the above determination can be performed after removing the base layer and the liquid-repellent layer using GCIB (Gas Cluster Ion Beam) to determine the content of trivalent Cr in the surface portion of the substrate adhesive layer.

[0103] Using the X-ray photoelectron spectroscopy analysis method described above, for example, by performing Cr sputtering and plasma treatment on a substrate, the content of each valence of Cr in the nozzle plate with the substrate adhesive layer is determined, and the content of trivalent Cr relative to the total Cr content can be calculated.

[0104] An example of the distribution of Cr valence in the substrate adhesive layer determined by the above method is shown below. Figure 5 .

[0105] <Analytical Method 2: Determination of the average composition ratio of each element in the substrate adhesive layer>

[0106] In this invention, the average composition ratio of each element in the surface portion of the substrate adhesive layer is calculated together with the content of trivalent Cr relative to the total Cr content. The average composition ratio is obtained by randomly measuring 10 samples, using the average value to determine the composition ratio (atomic %) of each element, and calculating the concentration ratio of Cr to Fe.

[0107] The analytical method 2 involved in this invention is the same as the elemental composition analysis described in analytical method 1 above. Since valence state analysis is not required, there is no special specification for "pass energy". For samples with a substrate layer and a liquid-repellent layer, the above determination can also be performed after removing the substrate layer and the liquid-repellent layer using GCIB (gas cluster ion beam) in the same manner as in analytical method 1.

[0108] <Analytical Method 3: Determination of Atomic Concentration Distribution in Layer Thickness>

[0109] In this invention, the atomic concentration distribution curve (hereinafter referred to as "depth profile") of the substrate adhesive layer in the thickness direction of the substrate involved in this invention can be determined by combining the concentration (atomic %) of metal oxides or nitrides, the concentration (atomic %) of silicon oxides or nitrides, and the concentration (atomic %) of carbon (C), nitrogen (N), oxygen (O), argon (Ar), fluorine (F), silicon (Si), chromium (Cr), iron (Fe), nickel (Ni), etc. with X-ray photoelectron spectroscopy and ion sputtering using rare gases, etc., to expose the substrate adhesive layer from the surface portion toward the substrate surface side, and simultaneously performing surface composition analysis of the surface portion of the substrate adhesive layer and the surface portion of the substrate in sequence.

[0110] The distribution curve obtained by such XPS depth profiling can be created, for example, by setting the vertical axis to the concentration of each element (unit: atomic %) and the horizontal axis to the etching time (sputtering time). It should be noted that in such an atomic concentration distribution curve where the horizontal axis is set to etching time, since the etching time is approximately related to the distance from the surface of the substrate adhesive layer in the thickness direction, the "distance from the surface of the substrate adhesive layer in the thickness direction" can be the distance from the surface of the substrate adhesive layer calculated from the relationship between the etching rate and etching time used in the XPS depth profiling. Furthermore, the sputtering method used in such XPS depth profiling can be a rare gas ion sputtering method using argon (Ar) as the etching ion species. The etching rate can be measured using a SiO2 thermal oxide film with a known film thickness, and the etching depth is usually expressed using a SiO2 thermal oxide film conversion value.

[0111] The following is an example of specific conditions for XPS analysis that can be applied to the compositional analysis of the surface region of the substrate adhesive layer involved in this invention.

[0112] • Analytical apparatus: QUANTERA SXM manufactured by ULVAC-PHI

[0113] • X-ray source: Monochromatic Al-Kα 15kV 25W

[0114] Sputtered ions: Ar (1keV)

[0115] • Depth profile: The sputtering thickness is converted to SiO2 and measured repeatedly at specified thickness intervals to obtain the depth profile in the depth direction. This thickness interval is set to 2.6 nm (to obtain data every 2.6 nm in the depth direction).

[0116] • Quantitative analysis: Background was determined using the Shirley method, and quantification was performed using the relative sensitivity coefficient method based on the obtained peak area. Data processing was performed using a MultiPak system manufactured by ULVAC-PHI.

[0117] The following is an example of the measurement results.

[0118] Figure 6 This is an example of the atomic concentration distribution curves (depth profiles) measured by XPS for a nozzle plate consisting of a substrate / substrate adhesive layer / base layer / liquid repellent layer.

[0119] Figure 6 The atomic concentration distribution curve (depth profile) shown represents an example of a substrate adhesive layer formed by directly performing plasma treatment on the surface of a SUS substrate using the plasma etching method described later. It indicates that the Cr concentration at the surface of the substrate adhesive layer is higher than that at the surface of the substrate.

[0120] In the constituent atoms from the hydrophobic layer to the substrate, the location where the concentration of C from the substrate layer is half of the peak concentration can be considered as the surface of the substrate bonding layer (the interface between the substrate layer and the substrate bonding layer). That is, the location approximately 113 nm from the surface of the hydrophobic layer at an etching time of 88 minutes can be considered as the interface between the substrate layer and the substrate bonding layer.

[0121] On the other hand, the location where the Cr concentration stagnates can be considered as the surface portion of the substrate adhesive layer (the interface between the substrate layer and the substrate adhesive layer). That is, here, the location approximately 164 nm from the surface of the water-repellent layer at an etching time of 128 minutes can be considered as the interface between the substrate adhesive layer and the substrate. It is known that there exists a layer where the Cr concentration at the surface portion of the substrate adhesive layer is greater than the Cr concentration at the surface portion of the substrate.

[0122] (Method for forming a substrate adhesive layer)

[0123] There are no particular limitations on the method for forming the substrate adhesive layer as involved in this invention, and the following methods can be applied.

[0124] Examples of film-forming methods applicable to the substrate adhesive layer of the present invention include dry film-forming methods such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), as well as wet film-forming methods such as electroplating and electroless plating. In the present invention, from the perspective of being able to form a dense film, a dry film-forming method is preferred.

[0125] In this invention, dry film formation methods include sputtering, vacuum evaporation, laser ablation, ion plating, electron beam epitaxy (MBE), metal-organic vapor deposition (MOCVD), plasma CVD, oxygen-based plasma etching mode (O2PE mode), and oxygen-based reactive ion etching mode (O2RIE mode). From the viewpoint of being able to form a dense film with a high Cr concentration, sputtering and oxygen-based plasma etching mode (O2PE mode) are preferred.

[0126] In this invention, from the viewpoint of being able to form a desired substrate adhesive layer, it is preferable to perform a surface treatment using plasma after film formation by sputtering.

[0127] (Specific film-forming methods for the substrate adhesive layer)

[0128] Two representative methods for forming a film on a substrate adhesive layer can be cited below.

[0129] 1. Film formation method 1: A method of forming a substrate adhesive layer by performing plasma treatment as described later on a substrate.

[0130] 2. Film formation method 2: After forming a Cr layer (100 atomic%) on the substrate by sputtering with Cr as the target, the Cr layer is subjected to plasma treatment as described later to form a substrate adhesive layer.

[0131] (1) Formation of a substrate adhesive layer using Cr sputtering

[0132] In sputtering, Cr is used as the target, and a film is formed by sputtering in an atmosphere such as argon, oxygen, or methane to create a substrate adhesive layer. The Cr content in the substrate adhesive layer formed by this sputtering method is approximately 100 atomic%.

[0133] The following is an example of a specific film formation method using sputtering.

[0134] Under vacuum conditions, sputtering of a pre-set Cr target is performed on the electrodes of a DC sputtering film deposition apparatus under the following conditions. At this time, other plasma sources can also be used, not limited to DC sputtering.

[0135] Target: Cr

[0136] DC power density: 1.1W / cm³ 2

[0137] Power: RF power (13.56MHz), 200W

[0138] Temperature: 25℃

[0139] Pressure: 0.3 Pa

[0140] Introduced gas: Argon

[0141] Film formation time: 30 seconds

[0142] The thickness of the substrate adhesive layer formed by the above sputtering method is 20 nm. As for the thickness of the substrate adhesive layer of the present invention, the thickness of the substrate adhesive layer is generally in the range of 1 to 5000 nm, preferably in the range of 1 to 100 nm, and from the viewpoint of alkali resistance of the nozzle plate and processability when making nozzle holes, it is more preferably in the range of 5 to 50 nm.

[0143] (2) Plasma treatment after Cr sputtering

[0144] As plasma etching modes applicable to the present invention, the RIE (Reactive Ion Etching) mode and the PE (Plasma Etching) mode can be cited. The "RIE" mode, as used in the present invention, refers to a method in which a substrate constituting a nozzle plate, such as SUS304, is disposed on the power supply electrode side of an opposing plate electrode pair as the object to be plasma treated, and plasma treatment is performed on the surface of the object. On the other hand, the "PE" (Plasma Etching) mode refers to a method in which a plasma object is disposed on the ground electrode side of an opposing plate electrode pair, and plasma treatment is performed on the surface of the object.

[0145] Furthermore, with reference to the accompanying drawings, detailed information related to each plasma etching mode is provided.

[0146] <RIE Mode Plasma Processing Apparatus>

[0147] Figure 7 This is a schematic diagram illustrating an example of a high-frequency plasma apparatus used in RIE (Reactive Ion Etching) mode for forming a substrate adhesive layer. RIE mode is suitable for surface processing utilizing physically high-speed ion bombardment.

[0148] exist Figure 7 In this RIE mode, the high-frequency plasma device 20A (hereinafter also referred to as "plasma processing device 20A") includes a reaction chamber 21, a high-frequency power supply 22 (RF (Radio Frequency) power supply), a capacitor 23, a planar electrode 24 (also referred to as a cathode, "power supply electrode"), a counter electrode 25 (also referred to as an anode, "ground electrode"), and a grounding part 26. The reaction chamber 21 has a gas inlet 27 and a gas outlet 28. The planar electrode 24 and the counter electrode 25 are arranged inside the reaction chamber 21.

[0149] A pair of electrodes, consisting of a planar electrode 24 connected to a high-frequency power supply 22 via a capacitor 23 and a counter electrode 25 opposite the planar electrode 24 and grounded via a grounding portion 26, are disposed within a sealable reaction chamber 21. Furthermore, a nozzle plate substrate 30, which is the object to be treated with plasma, is disposed on the planar electrode 24.

[0150] First, air is thoroughly removed from the reaction chamber 21 via the gas outlet 28. In this state, reactant gas G (Ar, O2, etc.) is supplied into the reaction chamber 21 via the gas inlet 27. Simultaneously, the high-frequency power supply 22 is activated. When power is supplied to the high-frequency power supply 22 at a high frequency of 3 MHz or higher and 100 MHz or lower (typically 13.56 MHz), a discharge D is generated between the planar electrode 24 and the counter electrode 25, forming a discharge space 31 that generates low-temperature plasma (cations and electrons) and free radicals of reactant gas G. At this time, the high-frequency power density is preferably set in the range of 0.01 to 3 W / cm².

[0151] In the above configuration, due to the difference in mobility between ions and electrons, electrons are trapped on the planar electrode 24, causing the planar electrode 24 to be negatively charged (self-biased). Electrons from the planar electrode 24 stop at the capacitor 23 via the power supply line 33. Meanwhile, electrons from the counter electrode 25 flow to the ground portion 26 via the power supply line 32.

[0152] On the other hand, free radicals and cations are not easily captured by the electrodes and move in the plasma. When the nozzle plate substrate 30, which is the object to be processed, is disposed on the planar electrode 24 in the plasma, an ion sheath layer with a strong electric field is generated on the side of the opposite electrode 25 of the nozzle plate substrate 30. Due to the descent of the cathode, an electric field of 400 to 1000 V is generated, and the cations moving in the nozzle plate substrate 30 collide or come into contact with the surface of the nozzle plate substrate 30. In this way, surface treatment (etching in this case) is performed on the object to be processed.

[0153] Examples of rare gases (e.g., helium, argon, krypton, xenon), oxygen, and hydrogen can be used as the reactive gas G in etching. However, in this invention, the RIE mode plasma treatment method using argon as the reactive gas G is referred to as "Ar-RIE mode plasma treatment", and the RIE mode plasma treatment method using oxygen as the reactive gas is referred to as "O2-RIE mode plasma treatment".

[0154] <PE Mode Plasma Processing Device>

[0155] Figure 8 This is a schematic diagram illustrating an example of a high-frequency plasma apparatus used for forming a PE mode (plasma etching mode) adhesive layer on a substrate. The PE mode allows for gentle processing with minimal ion collision effects.

[0156] Figure 8 The basic configuration of the high-frequency plasma device 20B in PE mode (hereinafter also referred to as "plasma processing device 20B") shown above is the same as described above. Figure 7 The high-frequency plasma device 20A of the RIE mode described herein is similar, but in the case of a nozzle plate substrate 30, which is the object to be treated by plasma, is arranged on the ground electrode 25 side of the opposing flat plate electrode pair, and a method for performing plasma treatment on the surface of the object to be treated by plasma.

[0157] In this invention, the PE mode plasma treatment method using argon as the reactant gas G is called "Ar-PE mode plasma treatment", and the PE mode plasma treatment method using oxygen as the reactant gas G is called "O2-PE mode plasma treatment".

[0158] (Thickness of the substrate adhesive layer)

[0159] In the nozzle plate of the present invention, the thickness of the substrate bonding layer is in the range of approximately 1 to 5000 nm, preferably in the range of 1 to 100 nm, and is further preferably in the range of 5 to 50 nm from the viewpoint of the alkali resistance of the nozzle plate and the processability when making the nozzle orifice.

[0160] [Basal layer]

[0161] The base layer 4 of the present invention is characterized in that it is formed between the substrate adhesive layer and the liquid repellent layer of the present invention, and is a layer containing at least inorganic oxides or oxides containing carbon (C).

[0162] There are no particular limitations on the inorganic oxides that can be used to form the substrate layer involved in this invention. Examples include oxides and composite oxides of metals, primarily transition metals, noble metals, alkali metals, and alkaline earth metals. More specifically, the inorganic oxide particles are preferably oxides or composite oxides containing one or more metal elements selected from silicon, aluminum, titanium, magnesium, zirconium, antimony, iron, and tungsten.

[0163] In addition, the aforementioned oxides or composite oxides may further contain one or more selected from phosphorus, boron, cerium, alkali metals, and alkaline earth metals.

[0164] Examples of common inorganic oxides include aluminum oxide, silicon dioxide, magnesium oxide, zinc oxide, lead oxide, tin oxide, tantalum oxide, indium oxide, bismuth oxide, yttrium oxide, cobalt oxide, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, germanium oxide, tin oxide, titanium oxide, niobium oxide, molybdenum oxide, and vanadium oxide.

[0165] Furthermore, in this invention, the substrate layer is preferably a layer composed primarily of silicon dioxide as the inorganic oxide contained therein. Additionally, the aforementioned inorganic oxide may also contain organic groups, resins, or other organic substances as secondary components.

[0166] In addition, the base layer is preferably an organic oxide containing at least carbon (C).

[0167] Examples of carbon (C)-containing organic oxides, such as silicon compounds, include silanes, tetramethoxysilanes, tetraethoxysilanes (TEOS), tetra-n-propoxysilanes, tetraisopropoxysilanes, tetra-n-butoxysilanes, tetra-tert-butoxysilanes, dimethyldimethoxysilanes, dimethyldiethoxysilanes, diethyldimethoxysilanes, diphenyldimethoxysilanes, methyltriethoxysilanes, ethyltrimethoxysilanes, phenyltriethoxysilanes, (3,3,3-trifluoropropyl)trimethoxysilanes, hexamethyldisiloxanes, bis-(dimethylamino)dimethylsilanes, bis-(dimethylamino)methylvinylsilanes, bis-(ethylamino)dimethylsilanes, N,O-bis... Titanium compounds include α-(trimethylsilyl)acetamide, bis-(trimethylsilyl)carbodiimide, diethylaminotrimethylsilane, dimethylaminodimethylsilane, hexamethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, nonamethyldisilazane, octamethylcyclotetrasilazane, tetra(dimethylamino)silane, tetraisocyanosilane, and tetramethyldisilazane. Examples of titanium compounds include titanium methoxide, titanium ethanol, titanium isopropoxide, titanium tetraisopropoxy, titanium n-butoxide, titanium diisopropoxy (bis-2,4-pentanedione), titanium diisopropoxy (bis-2,4-acetoethyl acetoacetate), titanium di-n-butoxy (bis-2,4-pentanedione), titanium acetylacetone, and titanium tetrabutyl titanate dimer. In addition, examples of zirconium compounds include: zirconium n-propoxide, zirconium n-butoxide, zirconium tert-butoxide, zirconium tri-n-butoxyacetylacetonate, zirconium di-n-butoxybisacetylacetonate, zirconium acetylacetonate, zirconium acetate, and zirconium hexafluoropentanedione. Examples of aluminum compounds include: aluminum ethoxide, aluminum triisopropoxide, aluminum isopropoxide, aluminum n-butoxide, aluminum sec-butoxide, aluminum tert-butoxide, aluminum acetylacetonate, and triethyltrisec-butoxyaluminum.

[0168] Among the above-mentioned organic oxides containing carbon (C), it is more preferable to use silane compounds (such as alkoxysilanes, silazanes, etc.) or silane coupling agents with a molecular weight of 300 or less to form a layer containing carbon (C), silicon (Si), and oxygen (O) as the main components.

[0169] As the base layer of the present invention, it is preferably a layer formed using a silane coupling agent, and more preferably the silane coupling agent contained in the base layer has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle.

[0170] As a specific composition of the substrate layer, for example, as an inorganic oxide applicable to the substrate layer of the present invention, it is preferred that the substrate layer is formed into a high-density polymer film by a dehydration condensation reaction of a silane coupling agent A having reactive functional groups at both ends and containing a hydrocarbon chain and a benzene ring in the middle (first substrate layer). Alternatively, it is another preferred method that the substrate layer is composed of an oxide mainly composed of an inorganic oxide or an organic oxide containing at least Si (second substrate layer).

[0171] (Formation of the base layer using silane coupling agent A: First base layer)

[0172] In this invention, silane coupling agent A, which has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle, is preferably used as a silane coupling agent for forming a base layer by a dehydration condensation reaction.

[0173] As a silane coupling agent A applicable to the substrate layer, there are no particular limitations, and conventionally known compounds that satisfy the above-mentioned technical features can be appropriately selected. However, from the viewpoint of being able to exert the objective effect of the present invention without omission, it is preferred to have a compound having the following structure: represented by the following general formula (1), having an alkoxy, chlorine, acyloxy, or amino group as a reactive functional group at both ends, and having a hydrocarbon chain and a benzene ring (phenylene) in the middle.

[0174] <Compounds having the structure represented by general formula (1)>

[0175] General formula (1)

[0176] X s Q 3-s Si(CH2) t C6H4(CH2) u SiR 3-m X m

[0177] In the above general formula (1), Q and R represent methyl or ethyl, respectively. t and u represent natural numbers from 1 to 10, respectively. s and m represent natural numbers from 1 to 3, respectively. When s is 1 and m is 1, there are two Q and two R, but the two Q and R can be the same structure or different structures. C6H4 represents phenylene. X represents alkoxy, chlorine, acyloxy, or amino.

[0178] The alkoxy group is, for example, an alkoxy group with 1 to 12 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, preferably an alkoxy group with 1 to 8 carbon atoms, and more preferably an alkoxy group with 1 to 6 carbon atoms.

[0179] In addition, examples of acyloxy groups include straight-chain or branched acyloxy groups with 2 to 19 carbon atoms (acetoxy, ethyl carbonyloxy, propyl carbonyloxy, isopropyl carbonyloxy, butyl carbonyloxy, isobutyl carbonyloxy, sec-butyl carbonyloxy, tert-butyl carbonyloxy, octyl carbonyloxy, tetradecyl carbonyloxy, and octadecyl carbonyloxy, etc.).

[0180] In addition, examples of amino groups include amino groups (-NH2) and substituted amino groups with 1 to 15 carbon atoms (e.g., methylamino, dimethylamino, ethylamino, methylethylamino, diethylamino, n-propylamino, methyl n-propylamino, ethyl n-propylamino, n-propylamino, isopropylamino, isopropylmethylamino, isopropylethylamino, diisopropylamino, phenylamino, diphenylamino, methylphenylamino, ethylphenylamino, n-propylphenylamino, and isopropylphenylamino, etc.).

[0181] Hereinafter, exemplary compounds having the structure represented by the general formula (1) of the present invention are listed, but the present invention is not limited to these exemplary compounds.

[0182] 1) 1,4-Bis(trimethoxysilylethyl)benzene

[0183] 2) 1,4-Bis(triethoxysilylethyl)benzene

[0184] 3) 1,4-Bis(trimethoxysilylbutyl)benzene

[0185] 4) 1,4-Bis(triethoxysilylbutyl)benzene

[0186] 5) 1,4-Bis(trimethylaminosilylethyl)benzene

[0187] 6) 1,4-Bis(triethylaminosilylethyl)benzene

[0188] 7) 1,4-Bis(trimethylaminosilylbutyl)benzene

[0189] 7) 1,4-Bis(triacetoxysilylethyl)benzene

[0190] 8) 1,4-Bis(trichloromethylsilylethyl)benzene

[0191] 9) 1,4-Bis(trichloroethylsilylethyl)benzene

[0192] The compounds having the structure represented by general formula (1) involved in this invention can be synthesized according to conventionally known synthetic methods. Alternatively, they can be obtained as commercially available products.

[0193] <Method for forming a substrate layer using silane coupling agent A>

[0194] The substrate layer of the present invention is formed by dissolving the silane coupling agent A, which has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle, in an organic solvent, such as ethanol, propanol, butanol, 2,2,2-trifluoroethanol, etc., to a desired concentration, to prepare a coating solution for substrate layer formation, and then coating it on a substrate by wet coating and drying.

[0195] The concentration of silane coupling agent A in the coating solution for forming the substrate layer is not particularly limited, and is approximately in the range of 0.5% to 50% by mass, preferably in the range of 1.0% to 30% by mass.

[0196] There is no particular limitation on the thickness of the first substrate layer involved in this invention, but it is preferably in the range of approximately 1 to 500 nm, and more preferably in the range of 5 to 200 nm.

[0197] (Formation of a substrate layer composed mainly of Si-containing organic oxides: second substrate layer)

[0198] In the substrate layer of the present invention, a second substrate layer composed of an oxide mainly composed of Si-containing organic oxides is also preferred.

[0199] Preferably, such as Figure 2 As shown, the base layer is composed of a base layer unit 4U consisting of two layers: a first base layer 6 and a second base layer 7. The first base layer 6 is composed of a first base layer containing a silane coupling agent A, which has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle as described above. It is preferred to make the second base layer 7 a second base layer composed of a Si-containing organic oxide as described below.

[0200] An example is shown of an alkoxysilane, silazane, or silane coupling agent with a molecular weight of 300 or less that can be applied to the present invention, but is not limited to these illustrated compounds. It should be noted that the values ​​listed in parentheses after each compound are molecular weights (Mw).

[0201] Examples of alkoxysilanes include tetraethoxysilane (Si(OC2H5)4, Mw: 208.3), methyltriethoxysilane (CH3Si(OC2H5)3, Mw: 178.3), methyltrimethoxysilane (CH3Si(OCH3)3, Mw: 136.2), dimethyldiethoxysilane ((CH3)2Si(OC2H5)2, Mw: 148.3), and dimethyldimethoxysilane ((CH3)2Si(OCH3)2, Mw: 120.2).

[0202] In addition, examples of silazanes include 1,1,1,3,3,3-hexamethyldisilazane ((CH3)3SiNHSi(CH3)3, 161.4), 1,1,1,3,3,3-hexaethyldisilazane ((C2H5)3SiNHSi(C2H5)3, 245.4), as well as 1,3-bis(chloromethyl)tetramethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, etc.

[0203] In addition, examples of silane coupling agents include:

[0204] 1) Vinyl silane coupling agents: vinyltrimethoxysilane (CH2=CHSi(OCH3)3, Mw: 148.2), vinyltriethoxysilane (CH2=CHSi(OC2H5)3, Mw: 190.3), as well as CH2=CHSi(CH3)(OCH3)2, CH2=CHCOO(CH2)2Si(OCH3)3, CH2=CHCOO(CH2)2Si(CH3)Cl2, CH2=CHCOO(CH2)3SiCl3, CH2=C(CH3)Si(OC2H5)3, etc.

[0205] 2) Amino silane coupling agents: 3-aminopropyltrimethoxysilane (H2NCH2CH2CH2Si(OCH3)3, Mw: 179.3), 3-(2-aminoethylamino)propyltrimethoxysilane (H2NCH2CH2NHCH2CH2CH2Si(OCH3)3, Mw: 222.4), 3-(2-aminoethylamino)propylmethyldimethoxysilane (H2NCH2CH2NHCH2CH2CH2Si(CH3)(OCH3)2, Mw: 206.4), etc.

[0206] 3) Epoxy silane coupling agents: 3-epoxypropoxypropyltrimethoxysilane (Mw: 236.3), 3-epoxypropoxypropyltriethoxysilane (Mw: 278.4), etc.

[0207] <Method for forming the second basal layer>

[0208] The second substrate layer of the present invention is formed by dissolving a silane compound with a molecular weight of 300 or less, such as conventionally known alkoxysilane, silazane, or silane coupling agent, in an organic solvent such as ethanol, propanol, butanol, 2,2,2-trifluoroethanol, etc., to a desired concentration to prepare a coating solution for forming an intermediate layer, and then coating it onto the substrate layer by a wet coating method and drying it.

[0209] The concentration of the inorganic oxide forming material in the coating liquid for forming the second base layer is not particularly limited, and is approximately in the range of 0.5% to 50% by mass, preferably in the range of 1.0% to 30% by mass.

[0210] The thickness of the second substrate layer involved in this invention is in the range of 0.5 to 500 nm, preferably in the range of 1 to 300 nm, and more preferably in the range of 5 to 100 nm.

[0211] [Liquid-repellent layer]

[0212] In this invention, the liquid-repellent layer preferably contains a coupling agent having fluorine (F) (hereinafter also referred to as coupling agent B).

[0213] As a coupling agent B containing fluorine (F) applicable in the liquid-repellent layer of the present invention, there are no particular limitations, but it is preferred to contain a fluorinated compound, which is (1) a compound containing at least alkoxysilyl, phosphonic acid or hydroxyl groups and having a perfluoroalkyl group, or a compound containing alkoxysilyl, phosphonic acid or hydroxyl groups and having a perfluoropolyether group, or (2) a mixture containing a compound having a perfluoroalkyl group, or a mixture containing a compound having a perfluoropolyether group.

[0214] Specific compounds containing fluorine (F) that can be used in the liquid-repellent layer of the present invention include: dichlorodimethyl[3-(2,3,4,5,6-pentafluorophenyl)propyl]silane, pentafluorophenyldimethylchlorosilane, pentafluorophenylethoxydimethylsilane, pentafluorophenylethoxydimethylsilane, trichloro(1H,1H,2H,2H-tridecylfluoro-n-octyl)silane, trichloro(1H,1H,2H,2H-heptadecylfluorodecyl)silane, trimethoxy(3,3,3-trifluoropropyl)silane, triethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, triethoxy- 1H,1H,2H,2H-heptadecylsilane, trimethoxy(1H,1H,2H,2H-heptadecyl)silane, trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, trichloro[3-(pentafluorophenyl)propyl]silane, trimethoxy(11-pentafluorophenoxyundecyl)silane, triethoxy[5,5,6,6,7,7,7-heptafluoro-4,4-bis(trifluoromethyl)heptyl]silane, trimethoxy(pentafluorophenyl)silane, triethoxy(1H,1H,2H,2H-nonafluorohexyl)silane, γ-glycidylpropyltrimethoxysilane, etc.

[0215] In addition, silane coupling agents containing fluorine (F) are also available as commercially available products. Examples include those from Toray Dow Corning Silicones Co., Ltd., Shin-Etsu Chemical Co., Ltd., Daikin Industries, Ltd. (e.g., OptoolDSX), Asahi Glass Co., Ltd. (e.g., CYTOP), Seko Co., Ltd. (e.g., Top CleanSafe (registered trademark)), FluoroTech No. 1 Co., Ltd. (e.g., Fluoro Serv), Gelest Inc., Solvay Solaris Co., Ltd. (e.g., Fluorolink S10), etc. Besides being readily available, J. Fluorine can also be cited as an example. The compounds described in Chem., 79(1), 87(1996), Materials Technology, 16(5), 209(1998), Collect.Czech.Chem.Commun., Vol.44, pp.750-755, J.Amer.Chem.Soc., 1990, Vol.112, pp.2341-2348, Inorg.Chem., Vol.10, pp.889-892, 1971, and U.S. Patent No. 3,668,233, etc. Alternatively, it can be manufactured using the synthesis methods described in Japanese Patent Application Publications Nos. 58-122979, 7-242675, 9-61605, 11-29585, 2000-64348, and 2000-144097, or based on those synthesis methods.

[0216] Specifically, examples of compounds having silane-terminated perfluoropolyether groups include, for example, "Optool DSX" manufactured by Daikin Industries, Ltd., as described above; examples of compounds having silane-terminated fluoroalkyl groups include, for example, "FG-5010Z130-0.2" manufactured by Floro Surf Co., Ltd.; examples of polymers having perfluoroalkyl groups include, for example, "Esefcote Series" manufactured by AGC Semikron Co., Ltd.; and examples of polymers having a fluorinated heterocyclic structure in the main chain include, for example, "Sitetop" manufactured by Asahi Glass Co., Ltd., as described above. Additionally, mixtures of FEP (tetrafluoroethylene-hexafluoropropylene copolymer) dispersions and polyamide-imide resins can also be cited.

[0217] As a method for forming a liquid-repellent layer using PVD, Merck Japan's Evaporation Substances WR1 and WR4, which are fluoroalkyl silane mixed oxides, are preferably used as fluorine-based compounds. For example, a silicon oxide layer is pre-formed as a base layer when forming a liquid-repellent layer using WR1 on a silicon substrate. Liquid-repellent layers formed using WR1 and WR4 exhibit liquid-repellent properties to alcohols such as ethanol, ethylene glycol (including polyethylene glycol), diluents, and organic solvents such as coatings, except for water.

[0218] The thickness of the liquid-repellent layer involved in this invention is generally in the range of 1 to 500 nm, preferably in the range of 1 to 400 nm, and more preferably in the range of 2 to 200 nm.

[0219] [Machining of the nozzle plate]

[0220] The method for manufacturing the nozzle plate of the present invention is detailed as described above, and is characterized in that...

[0221] 1) For the above-mentioned nozzle plate, at least a base layer and a liquid-repellent layer are formed on the substrate.

[0222] 2) A substrate bonding layer is formed between the above-mentioned substrate and the base layer.

[0223] 3) The above-mentioned substrate adhesive layer is configured to have a higher Cr concentration than the above-mentioned substrate.

[0224] 4) The above-mentioned substrate layer is formed using inorganic oxides or carbon (C)-containing oxides, and

[0225] 5) Use a coupling agent containing fluorine (F) to form the above-mentioned liquid-repellent layer.

[0226] In the above Figure 2 The nozzle plate 1 described herein is a schematic cross-sectional view showing an example of the configuration of the nozzle hole portion of the nozzle plate of the present invention.

[0227] like Figure 2 As shown, for the nozzle plate 1, a nozzle section N with a desired shape is formed as the ink ejection section.

[0228] Regarding the nozzle plate of the present invention, specific methods for forming nozzle holes, etc., can be found in, for example, those described in Japanese Patent Application Publication Nos. 2005-533662, 2007-152871, 2007-313701, 2009-255341, 2009-274415, 2009-286036, 2010-023446, 2011-011425, 2013-202886, 2014-144485, 2018-083316, and 2018-111208, and detailed descriptions are omitted here.

[0229] like Figure 2 As shown, in the configuration of the nozzle plate of the present invention, by forming a substrate bonding layer 3 with a high Cr concentration between the substrate 2 and the base layer 4, interface damage caused by ink In can be prevented, and a nozzle plate with high durability can be produced.

[0230] In the nozzle plate of the present invention, the nozzle holes are preferably formed by laser processing.

[0231] In the nozzle plate of the present invention, as a manufacturing method thereof, it is preferable to use a laser in the machining of the nozzle orifice shape, and more preferably the laser is a pulsed laser or a CW laser.

[0232] As for the laser that can be used in the manufacture of the nozzle plate of the present invention, a continuous oscillation type laser beam (CW laser beam) or a pulse oscillation type laser beam (pulse laser beam) is preferred.

[0233] The laser beams that can be used here include: gas lasers such as Ar lasers, Kr lasers, and excimer lasers; lasers using a medium formed by adding one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta as dopants in single-crystal YAG, YVO4, forsterite (Mg2SiO4), YAlO3, GdVO4, YLF, or polycrystalline (ceramic) YAG, Y2O3, YVO4, YAlO3, and GdVO4; glass lasers; ruby ​​lasers; alexandrite lasers; Ti:sapphire lasers; copper vapor lasers; or gold vapor lasers.

[0234] The lasers used are preferably ultraviolet lasers emitting wavelengths of around 266 nm, such as YAG-UV (yttrium aluminum garnet crystal: wavelength 266 nm) and YVO4 (wavelength: 355 nm). In particular, for lasers with wavelengths of around 266 nm, through thermal effects, when the workpiece is an organic material, molecular bonds such as CH bonds and CC bonds can be dissociated.

[0235] As an example of irradiation conditions, for instance, in the case of YAG-UV (wavelength: 266nm), the pulse width is 12nsec and the output is 1.6W, while in the case of YVO4 (wavelength: 355nm), the pulse width is 18nsec and the output is 2.4W.

[0236] Furthermore, a generation duration of approximately 10 can also be used. -11 seconds (10 psec) ~ 10 -14 Ultra-high-speed lasers with intense laser pulses lasting approximately 10 fsec (10 fsec) generate pulses over a period of approximately 10 seconds. -10 Seconds (100 psec) ~ 10 -11 Short-pulse lasers with strong laser pulses lasting 10 psec. These pulsed lasers can also be used for cutting or drilling a wide range of materials.

[0237] Inkjet Head

[0238] Figure 9 This is a schematic external view showing an example of the structure of an inkjet head to which the nozzle plate of the present invention can be applied. Additionally, Figure 10 This is a bottom view of an inkjet head equipped with the nozzle plate of the present invention.

[0239] like Figure 9 As shown, an inkjet head 100 equipped with the nozzle plate of the present invention is mounted on an inkjet printer (not shown), comprising: a head chip that ejects ink from a nozzle; a wiring substrate on which the head chip is disposed; a drive circuit substrate connected to the wiring substrate via a flexible substrate; a manifold that introduces ink into the channels of the head chip via a filter; a housing 56 that houses the manifold internally; a cover receiving plate that is installed to block the bottom opening of the housing 56; first and second connectors 81a and 81b installed at the first ink port and the second ink port of the manifold, respectively; a third connector 82 installed at the third ink port of the manifold; and a cover member 59 installed on the housing 56. Additionally, mounting holes 68 are formed for mounting the housing 56 to the printer body side.

[0240] in addition, Figure 10The cover receiving plate 57 shown corresponds to the shape of the cover receiving plate mounting part 62, and is formed into a generally rectangular plate with an elongated shape in the left-right direction. To expose the nozzle plate 61, on which multiple nozzles N are arranged approximately in the center, an elongated nozzle opening 71 is provided in the left-right direction. Furthermore, regarding... Figure 9 The specific internal structure of the inkjet head shown can be referred to, for example, in Japanese Patent Application Publication No. 2012-140017. Figure 2 wait.

[0241] exist Figure 9 as well as Figure 10 The illustration shows a representative example of an inkjet head. In addition, inkjet heads with structures described in Japanese Patent Application Publication No. 2012-140017, Japanese Patent Application Publication No. 2013-010227, Japanese Patent Application Publication No. 2014-058171, Japanese Patent Application Publication No. 2014-097644, Japanese Patent Application Publication No. 2015-142979, Japanese Patent Application Publication No. 2015-142980, Japanese Patent Application Publication No. 2016-002675, Japanese Patent Application Publication No. 2016-002682, Japanese Patent Application Publication No. 2016-107401, Japanese Patent Application Publication No. 2017-109476, and Japanese Patent Application Publication No. 2017-177626 can also be appropriately selected and applied.

[0242] Inkjet ink

[0243] There are no particular limitations on the inkjet inks that can be applied to inkjet recording methods using the inkjet head of the present invention. For example, there are various inkjet inks, such as water-based inkjet inks with water as the main solvent, oil-based inkjet inks with a non-volatile solvent that does not evaporate at room temperature and are essentially water-free, organic solvent-based inkjet inks with a solvent that evaporates at room temperature and are essentially water-free, hot melt inks that print by heating a solid ink to melt at room temperature, and active energy ray curing inkjet inks that are cured by active light such as ultraviolet light after printing. However, in the present invention, from the viewpoint of being able to exert the effects of the present invention, the use of alkaline ink is a preferred method.

[0244] Ink, for example, includes alkaline ink and acidic ink. In particular, alkaline ink may cause chemical degradation of the substrate, the liquid repellent layer, and the nozzle forming surface. However, in inkjet recording methods that use such alkaline ink, the application of an inkjet head equipped with the nozzle plate of the present invention is particularly effective.

[0245] In detail, the ink applicable to this invention comprises dyes, pigments, water, water-soluble organic solvents, pH adjusters, etc. Examples of water-soluble organic solvents that can be used include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerol, triethylene glycol, ethanol, propanol, etc. Examples of pH adjusters that can be used include sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, sodium bicarbonate, alkanolamines, hydrochloric acid, acetic acid, etc.

[0246] As a pH adjuster, when sodium hydroxide, potassium hydroxide, sodium acetate, sodium carbonate, sodium bicarbonate, alkanolamine, etc., are used, the ink becomes alkaline, which may cause chemical damage (chemical degradation) to the liquid repellent layer and nozzle forming surface. The pH of alkaline ink is above 8.0.

[0247] As described above, the liquid-repellent layer is formed from a fluorinated silane coupling agent or the like. The liquid-repellent layer has a structure in which the silicon-containing portion and the fluorinated portion are bonded together by substituents such as methylene (CH2). Since the bond energy between carbon (C) and carbon (C) is less than that between silicon (Si) and oxygen (O), and between carbon (C) and fluorine (F), the carbon (C) bonded portions are weaker than those bonded to silicon (Si) and oxygen (O), and are more susceptible to mechanical and chemical damage.

[0248] In inkjet recording methods that use alkaline inks that are prone to this phenomenon, the nozzle plate with the structure specified in this invention is effective in improving durability.

[0249] Example

[0250] The present invention will now be specifically described through examples, but the invention is not limited thereto. It should be noted that the terms "parts" or "%" are used in the examples, but unless otherwise specified, they represent "parts by mass" or "% by mass". Furthermore, unless otherwise specified, all operations are performed at room temperature (25°C).

[0251] Example 1

[0252] "Making of the Nozzle Plate"

[0253] [Making Nozzle Plate 1]

[0254] Make according to the following method Figure 4 The nozzle plate 1 is composed of substrate 2, substrate bonding layer 3, first base layer 6, second base layer 7, and liquid repellent layer 5 as described in the document.

[0255] (1) Preparation of substrate

[0256] As the substrate, an untreated stainless steel substrate (SUS304) with a length of 3cm, a width of 8cm, and a thickness of 50μm was used.

[0257] (2) Formation of the first layer (substrate adhesive layer 1)

[0258] <Step 1: Formation of a Cr layer using sputtering>

[0259] As a sputtering method, Cr is used as the target, and a film is formed on a substrate by sputtering under an argon atmosphere to create a single Cr metal layer. The Cr content in the Cr layer formed by this sputtering method is approximately 100 atomic%.

[0260] Specifically, under vacuum conditions, sputtering of a pre-set Cr target is performed on the electrodes of a DC sputtering film deposition apparatus under the following conditions.

[0261] Target: Cr

[0262] DC power density: 1.1W / cm³ 2

[0263] Power: RF power (13.56MHz), 200W

[0264] Temperature: 25℃

[0265] Pressure: 0.3 Pa

[0266] Introduced gas: Argon

[0267] Film formation time: 30 seconds

[0268] Layer thickness: 20nm

[0269] <Step 2: Etching using Ar-RIE plasma mode>

[0270] Next, the substrate in which the Cr layer was formed in step 1 was etched using the Ar-RIE plasma mode by the following method to form the substrate bonding layer 1.

[0271] Use by Figure 7 The high-frequency plasma device in RIE mode, which has a structure described in the paper, performs Ar plasma treatment on the Cr layer to form a substrate bonding layer 1 with a thickness of 20 nm.

[0272] The plasma treatment conditions are as follows.

[0273] Plasma processing device: High-frequency plasma device in RIE mode

[0274] Reacting gas G: Argon

[0275] Gas flow rate: 50 sccm

[0276] Gas pressure: 10 Pa

[0277] High-frequency power: 13.56MHz

[0278] High-frequency power density: 0.10 W / cm² 2

[0279] Inter-electrode voltage: 450W

[0280] Processing time: 3 minutes

[0281] Substrate processing temperature: below 80℃

[0282] (3) Formation of the second layer (first basal layer)

[0283] (Preparation of coating solution for forming the first base layer)

[0284] <Preparation of Solution A-1>

[0285] Mix the following constituent materials to prepare liquid A-1.

[0286] A mixed solution of ethanol and 2,2,2-trifluoroethanol (volume ratio 8:2) 30 mL

[0287] Silane coupling agent a: 1,4-bis(trimethoxysilylethyl)benzene ((CH3O)3Si(CH2)2(C6H4)(CH2)2Si(OCH3)3) 2mL

[0288] <Preparation of Solution A-2>

[0289] A mixed solution of ethanol and 2,2,2-trifluoroethanol (volume ratio 8:2) 19.5 mL

[0290] 30mL of pure water

[0291] Hydrochloric acid (36% by volume) 0.5 mL

[0292] (Formation of the first basal layer)

[0293] While stirring the prepared A-1 solution with a stir bar, 5 mL of A-2 solution was added dropwise. After stirring for about 1 hour after addition, the mixture was spin-coated onto the substrate adhesive layer with a first substrate layer thickness of 100 nm after drying. The spin-coating conditions were 5000 rpm for 20 seconds. Then, the substrate was dried at room temperature for 1 hour and then fired at 200°C for 30 minutes.

[0294] (4) Formation of the third layer (second basal layer)

[0295] (Preparation of coating solution for forming the second base layer)

[0296] Mix the following constituent materials to prepare a coating solution for forming the second base layer.

[0297] A mixed solution of ethanol and 2,2,2-trifluoroethanol (volume ratio 8:2) 69 mL

[0298] 30mL of pure water

[0299] Silane coupling agent c: 3-aminopropyltriethoxysilane ((C2H5O)3SiC3H6NH2, Shin-Etsu Chemical Co., Ltd. KBE-903) 1mL

[0300] (Formation of the second basal layer)

[0301] The prepared coating solution (KBE-903 concentration: 1.0 vol%) for forming the second substrate was applied to the first substrate layer using a spin-coating method, with the dried second substrate layer having a thickness of 20 nm. The spin-coating conditions were 3000 rpm for 20 seconds. The substrate was then dried at room temperature for 1 hour, followed by a heat treatment at 90°C and 80% RH for 1 hour.

[0302] (5) Formation of the fourth layer (liquid-repellent layer)

[0303] (Preparation of coating solution for forming liquid-repellent layer)

[0304] Mix the following constituent materials to prepare a coating liquid for forming a liquid-repellent layer.

[0305] A mixed solution of ethanol and 2,2,2-trifluoroethanol (volume ratio 8:2) 69.8 mL

[0306] 30mL of pure water

[0307] Fluorine-containing coupling agent b: (2-perfluorooctyl)ethyltrimethoxysilane (CF3(CF2)7C2H4Si(OCH3)3) 0.2mL

[0308] (Formation of the liquid-repellent layer)

[0309] The prepared coating solution containing 0.2 vol% of coupling agent b containing fluorine atoms was applied to the second substrate layer prepared above using a spin coating method, with the dried liquid-repellent layer thickness being 10 nm. The spin coating conditions were 1000 rpm for 20 seconds. Then, after drying the substrate at room temperature for 1 hour, it was heat-treated at 90°C and 80% RH for 1 hour to fabricate nozzle plate 1.

[0310] [Chemistry 1]

[0311] Silane coupling agent a

[0312]

[0313] Fluorine-containing coupling agent b

[0314]

[0315] Silane coupling agent C

[0316] (C2H5O)3SiC3H6NH2

[0317] (6) Determination of the content (atomic %) of trivalent Cr in the substrate adhesive layer relative to the total Cr content

[0318] X-ray photoelectron spectroscopy was used to determine, for a nozzle plate that has undergone Cr sputtering and plasma treatment to form a substrate adhesive layer, the following parameters were determined: Figure 5 The example shows the percentage (atomic %) of trivalent Cr relative to the total Cr content.

[0319] The specific measuring apparatus used was a QUANTERA SXM manufactured by ULVAC-PHI. During the measurement procedure, monochromatic Al-Kα was used at the X-ray anode, and the measurement was performed at an output of 25 W. Furthermore, the detailed analysis methods for the measurement data are as described above and are omitted here.

[0320] The content of trivalent Cr in the substrate adhesive layer constituting the nozzle plate 1, as determined by the above method, is 90 atoms.

[0321] (7) Determination of Cr / Fe ratio in the substrate adhesive layer

[0322] XPS (X-ray photoelectron spectroscopy) was used to irradiate the surface of a nozzle plate with a substrate adhesive layer formed by Cr sputtering and plasma treatment on a substrate with X-rays, and the energy of the generated photoelectrons was measured. The concentrations (atomic %) of the metals (Cr, Fe), oxygen (O), nitrogen (N), and carbon (C) that constitute the sample were then analyzed.

[0323] The measurement conditions are as follows.

[0324] • Analytical apparatus: QUANTERA SXM manufactured by ULVAC-PHI

[0325] • X-ray source: Monochromatic Al-Kα

[0326] The Cr content on the surface of the stainless steel substrate, as determined by the above method, was 9.8 atomic%. Furthermore, the Cr content on the surface of the substrate adhesive layer was 17.6 atomic%.

[0327] Furthermore, regarding the Cr / Fe ratio in the substrate adhesive layer constituting the nozzle plate 1, Cr is essentially 100 atomic%, and Fe is almost undetectable, therefore it is shown as "∞" in Table I.

[0328] [Making Nozzle Plate 2]

[0329] In the fabrication of the above-mentioned nozzle plate 1, in step 2 of the substrate bonding layer formation process, "etching using Ar-RIE plasma mode", the high frequency density conditions and processing time are appropriately adjusted to change the content of trivalent Cr in the substrate bonding layer relative to the total Cr content to 57 atomic%. Otherwise, the nozzle plate 2 is fabricated in the same way.

[0330] The Cr content on the surface of the stainless steel substrate, as determined by the above method, was 9.8 atomic%. Furthermore, the Cr content on the surface of the substrate adhesive layer was 25.3 atomic%.

[0331] [Making Nozzle Plate 3]

[0332] In the fabrication of the nozzle plate 1, step 2 of the substrate bonding layer formation process, "etching using Ar-RIE plasma mode," is changed to "etching using O2-RIE plasma mode," where O2 gas is used instead of Ar gas as the reaction gas. Otherwise, the nozzle plate 3 is fabricated in the same manner. The substrate bonding layer of the nozzle plate 3 has a trivalent Cr content of 44 atoms relative to the total Cr content.

[0333] The Cr content on the surface of the stainless steel substrate, as determined by the above method, was 9.8 atomic%. Furthermore, the Cr content on the surface of the substrate adhesive layer was 20.3 atomic%.

[0334] [Making Nozzle Plate 4]

[0335] In the fabrication of the nozzle plate 1 described above, the nozzle plate 4 is fabricated in the same manner, except that step 1 of the substrate bonding layer formation process, "forming a Cr layer by sputtering," is omitted, and the formation of the second layer, "first substrate layer," and the third layer, "second substrate layer," is not performed. The Cr / Fe ratio of the substrate bonding layer of the nozzle plate 4 is 0.5, and the content of trivalent Cr relative to the total Cr content is 41 atoms.

[0336] The Cr content on the surface of the stainless steel substrate, as determined by the above method, was 9.8 atomic%. Furthermore, the Cr content on the surface of the substrate adhesive layer was 5.9 atomic%.

[0337] [Making Nozzle Plate 5]

[0338] In the fabrication of the aforementioned nozzle plate 4, a plasma treatment device, used to form a substrate adhesive layer, is used instead of the [other device / equipment]. Figure 7The high-frequency plasma device in RIE mode with the structure described in the document uses... Figure 8 The high-frequency plasma device in PE mode described herein uses "etching with O2-PE plasma mode" to form a substrate adhesive layer, and in addition, nozzle plate 5 is also fabricated in the same way.

[0339] The Cr / Fe ratio of the substrate adhesive layer of nozzle plate 5 is 1.0, and the content of trivalent Cr relative to the total Cr content (atomic %) is 35 atoms.

[0340] The Cr content on the surface of the stainless steel substrate, as determined by the above method, was 9.8 atomic%. Furthermore, the Cr content on the surface of the substrate adhesive layer was 8.5 atomic%.

[0341] [Making Nozzle Plate 6]

[0342] In the fabrication of the above-mentioned nozzle plate 1, the nozzle plate 6 was fabricated in the same manner, except that the substrate adhesive layer was not formed.

[0343] Evaluation of Nozzle Plates

[0344] The ink resistance and abrasion durability of each of the above-prepared nozzle plates were evaluated according to the following method.

[0345] [Evaluation of ink resistance]

[0346] (Formation of the nozzle orifice)

[0347] For the nozzle plates 1 to 6 fabricated above, multiple [pieces] are formed using a laser processing machine. Figure 1 or Figure 2 The nozzle orifice described in the text has a diameter of 25 μm.

[0348] (Evaluation of actual ink preparation: Disperse dye ink)

[0349] <Preparation of Dispersion>

[0350]

[0351] The above mixture was dispersed for 5 hours using ceramic beads with a diameter of 0.5 mm in an Imex mill at 2500 rpm. The dispersion was then diluted with water / diethylene glycol at a ratio of 1:4 to obtain a dye concentration of 5%, thus preparing dispersion 1.

[0352] <Preparation of Actual Ink>

[0353] Add each composition to the above dispersion 1 and stir to prepare the actual ink (disperse dye ink) for evaluation.

[0354]

[0355] Ion-exchanged water was added to bring the final concentration to 100% by mass. The liquid properties of the prepared ink were investigated and confirmed to be alkaline (pH 8.0 or higher).

[0356] (Evaluation of the nozzle plate)

[0357] The nozzle plate with each nozzle hole was immersed in actual ink at 65°C for 40 days.

[0358] After immersion treatment, wash with pure water and dry, then observe with a 100x magnifying glass. Figure 1 , Figure 2 Whether there is peeling between the substrate and the substrate adhesive layer inside the nozzle orifice is shown. The adhesion resistance of the nozzle orifice to the actual ink is evaluated according to the following criteria.

[0359] ◎: No peeling was observed in any of the nozzles.

[0360] ○: Very weak peeling was confirmed in less than 5% of nozzles, but it poses no practical problem.

[0361] △: Weak isolation confirmed in nozzles of 5% to 10% is a practically acceptable quality.

[0362] ×: The presence of nozzles with obvious peeling is a quality issue that becomes problematic in practical use.

[0363] [Evaluation of wear durability (scrub resistance)]

[0364] (Preparation of black ink)

[0365] Prepare an evaluation black ink consisting of the following components.

[0366] <Preparation of Black Pigment Dispersions>

[0367]

[0368] The mixture was then dispersed in a horizontal bead mill filled with 60% by volume of 0.3 mm zirconium oxide beads to obtain a black pigment dispersion. The average particle size was 125 nm.

[0369] <Preparation of Black Ink>

[0370]

[0371] (Swabbing test)

[0372] Inside a container holding the black ink prepared above at 25°C, nozzle plates with multiple nozzle holes formed by the above method using a fixing fixture are fixed with the liquid-repellent layer as the upper surface. The surface of the liquid-repellent layer of the nozzle plate is repeatedly abraded (wiped) using a wiper made of ethylene propylene diene rubber, and the wear durability is evaluated according to the following criteria.

[0373] ◎: Even after more than 5,000 wiping operations, no peeling of the repellent layer near the nozzle was observed in any of the nozzles.

[0374] ○: In fewer than 5000 wiping operations, no peeling of the repellent layer near the nozzle was observed in all nozzles. However, in more than 5000 wiping operations, very weak peeling was observed in less than 5% of the nozzles.

[0375] △: In fewer than 1000 wiping operations, no peeling of the repellent layer near the nozzle was observed in all nozzles. However, in the range of 1000 to 5000 wiping operations, extremely weak peeling was observed in less than 5% of the nozzles.

[0376] ×: The occurrence of nozzle delamination, a significant problem arising from the stripping of the repellent layer, was confirmed during 1000 wiping cycles, proving to be practically problematic.

[0377] The evaluation results obtained above are shown in Table I.

[0378] [Table 1]

[0379] Table I

[0380]

[0381] As shown in Table I, it can be seen that, compared to the comparative example, the nozzle plate composed of the structure specified in this invention exhibits superior performance. Even when exposed to alkaline ink components for extended periods or when the surface is subjected to stress, the base layer functions as a stress-relieving layer, and the bonding between the constituent layers is high, resulting in excellent ink resistance and abrasion durability. Furthermore, it can be seen that even after prolonged immersion in alkaline ink, the nozzle plate of this invention maintains excellent adhesion between the substrate and the substrate bonding layer inside the nozzle orifice.

[0382] Example 2

[0383] For nozzle plates 11 to 13, which were manufactured similarly to nozzle plates 1 to 3 in Example 1, except that the materials constituting the first and second base layers were changed from silane coupling agents, which are carbon-containing oxidants, to SiO2, which is an inorganic oxide, and for nozzle plates 21 to 23, which were manufactured similarly except that the materials constituting the first and second base layers were changed from silane coupling agents, which are TiO2, which is an inorganic oxide, ink resistance and wear durability were evaluated in the same manner as described in Example 1. The results were the same as those in Example 1, confirming that the ink resistance and wear durability were excellent.

[0384] Industrial availability

[0385] The nozzle plate of the present invention has excellent sealing between constituent components, ink resistance and wear durability, and is suitable for use in inkjet printers that use ink in various fields.

[0386] Explanation of reference numerals in the attached figures

[0387] 1 Nozzle plate

[0388] 2. Substrate

[0389] 3. Substrate Adhesive Layer

[0390] 4. Basal layer

[0391] 4U base layer unit

[0392] 5. Liquid-repellent layer

[0393] 6. First basal layer

[0394] 7. Second basal layer

[0395] 20A RIE plasma processing unit

[0396] 20B PE Plasma Processing Unit

[0397] 21 Reaction Chamber

[0398] 22 High-frequency power supply

[0399] 23 Capacitors

[0400] 24. Planar electrode (power supply electrode)

[0401] 25. Opposite electrode (grounding electrode)

[0402] 26 Grounding

[0403] 27 Gas inlet

[0404] 28 Gas outlet

[0405] 30 Nozzle plate substrate

[0406] 31 Discharge Space

[0407] Power supply lines 32 and 33

[0408] 56. Shell

[0409] 57 Cover bearing plate

[0410] 59 Cover components

[0411] 61 Nozzle Plate

[0412] 62 Cover bearing plate installation section

[0413] 68 mounting holes

[0414] 71 Nozzle opening

[0415] 81a Connector 1

[0416] 81b Connector 2

[0417] 82 Third connector

[0418] 100 inkjet heads

[0419] D discharge

[0420] G Reaction Gas

[0421] N nozzle

[0422] P pump

Claims

1. A nozzle plate having at least a base layer and a liquid-repellent layer on a substrate, characterized in that, A substrate bonding layer is provided between the substrate and the base layer. The Cr concentration (atomic %) on the surface of the substrate adhesive layer is higher than that on the surface of the substrate. The substrate layer is a layer containing at least inorganic oxides or carbon (C)-containing oxides, and The liquid-repellent layer is formed using a coupling agent containing fluorine (F). The content of trivalent Cr on the surface of the substrate adhesive layer is more than 50 atomic% relative to the total Cr content.

2. The nozzle plate according to claim 1, characterized in that, In the concentration (atomic %) ratio of the constituent elements in the surface portion of the substrate adhesive layer, the ratio of the concentration (atomic %) of Cr to Fe (Cr / Fe) is 0.8 or more.

3. The nozzle plate according to claim 1 or 2, characterized in that, The thickness of the substrate adhesive layer is in the range of 1 to 50 nm.

4. The nozzle plate according to claim 1 or 2, characterized in that, The substrate layer contains an oxide composed of at least carbon (C), silicon (Si), and oxygen (O) as the carbon (C) oxide.

5. The nozzle plate according to claim 1 or 2, characterized in that, The base layer is a layer containing a silane coupling agent as the carbon (C) oxide.

6. The nozzle plate according to claim 5, characterized in that, The silane coupling agent contained in the base layer has reactive functional groups at both ends and contains a hydrocarbon chain and a benzene ring in the middle.

7. The nozzle plate according to claim 1 or 2, characterized in that, The substrate is stainless steel.

8. An inkjet head, characterized in that, It has a nozzle plate according to any one of claims 1 to 7.

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