Ink ejection device

Abstract

An ink ejection device according to the present invention comprises a base material, a resin layer laminated so that at least one main surface thereof is in contact with the base material, and an ink flow path arranged so that ink flows through in contact with a part of the resin layer, the ink ejection device being characterized by that the resin layer includes carbon, oxygen, nitrogen and silicon, and at least one of the main surfaces satisfies the following requirements (1) and (2). (1) The main surface is in contact with the base material. (2) The relationship between the atomic concentrations (atm%) of nitrogen, oxygen, and silicon in the main surface and the inside of the resin layer measured by X-ray photoelectron spectroscopy is such that main surface O > inner O, main surface N > 0, and the ratio of main surface Si / inner Si is 5 or more.

Description

[Technical Field]

[0001] The present invention relates to an ink ejection device, and more particularly to an ink ejection device that has excellent ink resistance at the interface between a resin layer disposed between substrates or on a substrate and the substrate, thereby providing long-term reliability. [Background technology]

[0002] Recently, inks have been developed that contain less water and more solvent to prevent curling of printed materials when printing on paper media, and inks that contain large amounts of water-soluble solvents, such as methylpyrrolidone and γ-butyrolactone, that are highly soluble in resins, to improve printing characteristics on non-absorbent film media. Although these inks are water-based inks that contain water, they have strong organic solvent properties, which increases their permeability into resin layers, such as adhesive layers and protective layers, of ink-ejecting devices.

[0003] Therefore, when the ink is used in an ink-ejecting device that uses conventional water-based inks, the ink easily penetrates the resin layer and also easily penetrates into the interface between the substrate and the resin layer. In particular, when a resin layer is formed between or on substrates made of a hydrophilic material such as metal or metal oxide, the ink easily penetrates into the interface between the substrate and the resin layer, resulting in a problem of a significant decrease in adhesive strength between the substrate and the resin layer.

[0004] To solve the above problems, for example, Patent Document 1 describes a liquid ejection head having a flow path composed of a first member, a resin layer, and a second member, in which the resin layer contains a cured product of a resin composition containing an epoxy compound, a polythiol compound having two or more thiol groups in the molecule, and an imidazole compound. Patent Document 1 also describes that the resin layer has high organic solvent resistance and can be cured at low temperatures, and that a liquid ejection head including the resin layer has excellent initial adhesion and adhesion reliability.

[0005] Furthermore, Patent Document 2 describes a formulation for a resin layer that bonds a vibration means that applies pressure to the pressure generating chambers to a flow path forming part in a liquid ejection head having a flow path forming part in which pressure generating chambers are arranged, and that has high adhesion while being cured at low temperatures (60°C, 80°C). Specifically, the formulation describes a resin layer formed from a curable resin composition containing an epoxy resin, a polythiol compound, a specific adhesion-imparting compound, and a curing accelerator.

[0006] However, in the resin layer of the liquid ejection heads described in these patent documents, depending on the type of ink used, there are cases where the adhesion at the interface between the resin layer and the base material such as a flow path forming component is insufficient. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-221541 [Patent Document 2] Japanese Patent Application Publication No. 2019-155792 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above problems and circumstances, and the problem to be solved is to provide an ink ejection device that has excellent ink resistance at the interface between the substrate and a resin layer disposed between or on the substrate, thereby providing long-term reliability. [Means for solving the problem]

[0009] In the course of investigating the causes of the above problems in order to solve them, the present inventors discovered that by configuring the resin layer in a specific manner in an ink-jet device comprising a substrate, a resin layer laminated so that at least one main surface thereof is in contact with the substrate, and an ink flow path arranged so that ink flows through the resin layer by contacting a portion of the resin layer, it is possible to obtain an ink-jet device having excellent ink resistance at the interface between the substrates or on the substrate and the resin layer, thereby achieving long-term reliability, and thereby arriving at the present invention. That is, the above problems according to the present invention are solved by the following means.

[0010] 1. An ink ejection device comprising a substrate, a resin layer laminated so that at least one of its main surfaces is in contact with the substrate, and an ink flow path arranged so that ink flows while contacting a portion of the resin layer, The resin layer contains carbon, oxygen, nitrogen, and silicon, and An ink ejection device characterized in that at least one of the main surfaces satisfies the following requirements (1) and (2). (1) The main surface is in contact with the substrate. (2) When the atomic concentrations (atm %) of nitrogen, oxygen, and silicon on the main surface of the resin layer measured by X-ray photoelectron spectroscopy are represented by main surface N, main surface O, and main surface Si, respectively, and the atomic concentrations (atm %) of nitrogen, oxygen, and silicon inside the resin layer are represented by internal N, internal O, and internal Si, respectively, the order of the atomic concentrations is as follows: main surface O>internal O, and main surface N> 3.62 and the ratio of the main surface Si to the internal Si, expressed as main surface Si / internal Si, is 10.9 That's all.

[0011] 2. The ink ejection device according to claim 1, characterized in that the main surface satisfies the requirements (1) and (2) above, and further satisfies the requirement (3). (3) The ratio of the main surface N to the internal N, expressed as main surface N / internal N, is 2.2 That's all.

[0012] 3. The spectrum obtained by analyzing the bonding state of nitrogen atoms by X-ray photoelectron spectroscopy for a main surface that satisfies the requirements (1) and (2) above is -NH2 or -NH3 + 3. The ink ejection device according to claim 1 or 2, wherein the ink ejection device has a peak of:

[0013] 4. The resin layer is formed by the use of an epoxy compound and H at 25°C. + 4. The ink ejection device according to any one of items 1 to 3, characterized in that the ink is a cured product of a resin composition containing a curing agent whose adduct has a pKa of 3 or more and an amino-based silane coupling agent.

[0014] 5. The ink ejection device according to claim 4, wherein the curing agent is a nitrogen-containing catalyst type curing agent.

[0015] 6. The content of the curing agent relative to the total amount of the resin composition is 8.93~9.07 6. The ink ejection device according to item 4 or 5, wherein the content is within the range of % by mass.

[0016] 7. The molecular weight per nitrogen atom in the amino-silane coupling agent is 179.29 7. The ink ejection device according to any one of items 4 to 6, characterized in that:

[0017] 8. The amino-silane coupling agent has an alkoxy group bonded to a silicon atom. Three 8. The ink ejection device according to any one of items 4 to 7, further comprising:

[0018] 9. The material constituting the substrate with which the main surface that satisfies the requirements (1) and (2) is in contact is Stainless steel (SUS) 9. The ink ejection device according to any one of items 1 to 8, characterized in that:

[0019] 10. The ink is PO 4 3- 10. The ink ejection device according to any one of items 1 to 9, wherein the ink contains an anion. [Effects of the Invention]

[0020] According to the above-mentioned means of the present invention, the interface between the substrate and the resin layer disposed between or on the substrate has excellent ink resistance, and therefore it is possible to provide an ink-jet device endowed with long-term reliability. The mechanism of manifestation or action of the effects of the present invention is presumed as follows.

[0021] The ink ejection device of the present invention is an ink ejection device comprising a substrate, a resin layer laminated so that at least one main surface thereof is in contact with the substrate, and an ink flow path arranged so that ink flows while contacting a portion of the resin layer, and the resin layer has the following characteristics.

[0022] The resin layer contains carbon, oxygen, nitrogen, and silicon, and at least one of the main surfaces satisfies the above requirements (1) and (2).

[0023] The resin layer of the ink ejection device of the present invention may be configured, for example, such that only one main surface of the resin layer is in contact with the substrate (hereinafter also referred to as a "configuration having a resin layer on a substrate"), or such that the resin layer is sandwiched between two substrates and both main surfaces of the resin layer are in contact with the respective substrates (hereinafter also referred to as a "configuration having a resin layer between substrates"). In the case of a configuration having a resin layer on a substrate, the resin layer is configured, for example, such that the main surface opposite to the surface in contact with the substrate is in contact with the ink flow path. In the case of a configuration having a resin layer between substrates, the resin layer is configured, for example, such that the side surface is in contact with the ink flow path.

[0024] In the ink-jet device of the present invention, the requirement (2) is satisfied on the main surface facing the substrate when the ink-jet device has a resin layer on the substrate, and on at least one of the main surfaces in contact with the substrate when the ink-jet device has a resin layer between the substrates. The requirement (2) is comprised of three requirements: (2-1) main surface O > interior O, (2-2) main surface N > 0, and (2-3) main surface Si / interior Si ≥ 5. In the present invention, the indices used in the above (2-1) to (2-3) are used as indices indicating the presence of chemical bonds, groups that trap ink components, or the like, at the interface between the substrate and the resin layer.

[0025] Specifically, when a resin layer is formed on a substrate as a cured product of a resin composition, a chemical bond is formed between the substrate and the resin layer by reacting a reactive group on the substrate surface with a component in the resin composition, thereby imparting strong adhesiveness. When a resin layer is formed so as to be sandwiched between substrates, the chemical bond is formed on the surface of at least one or both of the two substrates that contacts the resin layer, thereby improving the ink resistance of the adhesiveness of the resin layer that bonds the substrates.

[0026] In the present invention, the "substrate-O-Si" bond (covalent bond) is assumed as an indicator of the amount of chemical bonding, and the requirements (2-1) and (2-3) are set. When the reactive group on the substrate surface is an OH group and the resin composition contains a compound having a hydrolyzable silyl group, the hydrolyzable silyl group first undergoes a hydrolysis reaction to form a silanol group (Si-OH), and the silanol group then undergoes a dehydration condensation reaction with the OH group (substrate-OH) on the surface of the substrate to form a chemical bond (substrate-O-Si). Therefore, if the requirements (2-1) and (2-3) are satisfied, the "-O-Si" bond bonded to the substrate is present in a sufficient amount to enhance the adhesion between the substrate and the resin layer on the main surface facing the substrate in the case of a configuration having a resin layer on the substrate, or on at least one main surface in contact with the substrate in the case of a configuration having a resin layer between substrates.

[0027] In the present invention, when a resin layer is disposed on a substrate, if nitrogen atoms are present on the main surface on the substrate side, or when a resin layer is disposed between substrates, if nitrogen atoms are present on at least one of the main surfaces in contact with the substrate, then ink components can be trapped at the interface between the main surface of the resin layer and the substrate, and thus the requirement (2-2) was set.

[0028] When nitrogen atoms exist on the main surface as, for example, primary amino groups (-NH2), they become charged and have the effect of trapping ink components such as water and acid, preventing ink from penetrating into the interface between the resin layer and the substrate, improving the ink resistance of the constituent material. When nitrogen atoms exist as, for example, primary amino groups (-NH2), they form hydrogen bonds with OH groups on the surface of the substrate, forming a bond between the substrate and the O- -NH3 + -NH3 which participates in hydrogen bonding with the substrate surface + Although the group cannot trap water or acid, the hydrogen bond can be easily broken, and the -NH2 group can contribute to trapping water or acid that enters from the outside.

[0029] In this way, the present invention uses the above index to define the relationship between the content of a specific atomic species inside and the main surface of the resin layer in contact with the substrate, thereby improving the ink resistance at the interface between the substrate and the resin layer disposed between or on the substrate, thereby making it possible to provide an ink-jet device with long-term reliability. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a peripheral portion of a resin layer when only one main surface of the resin layer is in contact with a substrate. [Figure 2] FIG. 1 is a cross-sectional view schematically showing a peripheral portion of a resin layer when both main surfaces of the resin layer are in contact with a substrate. [Figure 3] 1 is a perspective view showing an example of an embodiment of an ink ejection device of the present invention; [Figure 4] 4 is a bottom view of the ink ejection device shown in FIG. 3. [Figure 5] FIG. 4 is a cross-sectional view of the lower part of the ink ejection device shown in FIG. 3 taken in the left-right direction. [Figure 6] FIG. 4 is an exploded perspective view of a head chip included in the ink ejection device shown in FIG. 3. [Figure 7] Cross-sectional view taken along line VII-VII in Figure 6 [Figure 8] Enlarged view of the area enclosed by the dashed line in Figure 7 [Figure 9] FIG. 10 is a partial cross-sectional view of another example of an ink ejection device according to an embodiment of the present invention. [Figure 10] An enlarged view of the portion of the ink ejection device shown in FIG. 9 surrounded by a dashed line. [Figure 11A] FIG. 1 shows a depth profile obtained by XPS according to Example 1. [Figure 11B]FIG. 10 is a diagram showing a depth profile by XPS according to Example 2. [Figure 11C] FIG. 10 is a diagram showing a depth profile by XPS according to Example 3. [Figure 12A] FIG. 1 shows a spectrum obtained by analyzing the bonding state of nitrogen atoms by XPS according to Example 1. [Figure 12B] FIG. 10 is a diagram showing a spectrum obtained by analyzing the bonding state of nitrogen atoms by XPS according to Example 2. [Figure 12C] FIG. 10 is a diagram showing a spectrum obtained by analyzing the bonding state of nitrogen atoms by XPS according to Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0031] The ink ejection device of the present invention is an ink ejection device comprising a substrate, a resin layer laminated so that at least one of its main surfaces is in contact with the substrate, and an ink flow path arranged so that ink flows through the resin layer while contacting a portion of the resin layer, wherein the resin layer contains carbon, oxygen, nitrogen, and silicon, and at least one of the main surfaces satisfies the following requirements (1) and (2): (1) The main surface is in contact with the substrate. (2) When the atomic concentrations (atm %) of nitrogen, oxygen, and silicon on the main surface of the resin layer measured by X-ray photoelectron spectroscopy are represented by main surface N, main surface O, and main surface Si, respectively, and the atomic concentrations (atm %) of nitrogen, oxygen, and silicon inside the resin layer are represented by internal N, internal O, and internal Si, respectively, main surface O>internal O and main surface N>0, and the ratio of main surface Si to internal Si, represented by main surface Si / internal Si, is 5 or more. This feature is a technical feature common to or corresponding to each of the following embodiments.

[0032] In an embodiment of the present invention, from the viewpoint of further achieving the effects of the present invention, it is preferable that the main surface satisfying the requirements (1) and (2) further satisfy the requirement (3) that "the ratio of main surface N to internal N, expressed as main surface N / internal N, is 1.5 or more." This further improves the effect of trapping ink components at the interface between the main surface of the resin layer and the substrate.

[0033] In an embodiment of the present invention, from the viewpoint of further exhibiting the effects of the present invention, a spectrum obtained by analyzing the bonding state of nitrogen atoms by X-ray photoelectron spectroscopy for a main surface that satisfies the requirements (1) and (2) above is -NH2 or -NH3 + Preferably, the spectrum has a peak of -NH2 and a peak of -NH3 + It may be a spectrum that does not have a peak of -NH2 and does not have a peak of -NH3 + The spectrum may have a peak of -NH2 and a peak of -NH3 + The spectrum may have both a peak of -NH2 and a peak of -NH3. + A spectrum having both peaks is obtained.

[0034] -NH3 present on the main surface that satisfies the requirements (1) and (2) above + As mentioned above, it is considered that the OH group on the substrate surface is in a hydrogen bonded state. When the OH group on the substrate surface is consumed by hydrogen bonding with -NH2, the hydrolyzable silyl group and the substrate surface can no longer bond at that point. Also, in the -NH2 state, it can trap water and acid that penetrates from the outside, but in the -NH3 + However, if hydrogen bonds with the substrate surface are not broken, water and acid cannot be trapped. + can easily become -NH2, so the nitrogen atom present on the main surface that satisfies the requirements of (1) and (2) is -NH2 or -NH3 + It is preferred that it is present as

[0035] In an embodiment of the present invention, from the viewpoint of further exhibiting the effects of the present invention, the resin layer is formed by mixing an epoxy compound, H + The cured product is preferably a resin composition containing a curing agent whose adduct has a pKa of 3 or more and an amino-based silane coupling agent.

[0036] In an embodiment of the present invention, the curing agent is preferably a nitrogen-containing catalyst-type curing agent, from the viewpoint of further exhibiting the effects of the present invention.

[0037] In an embodiment of the present invention, from the viewpoint of being able to more effectively exhibit the effects of the present invention, the content of the curing agent relative to the total amount of the resin composition is preferably within a range of 3 to 15% by mass.

[0038] As an embodiment of the present invention, from the viewpoint of further exhibiting the effects of the present invention, the molecular weight per nitrogen atom in the amino-based silane coupling agent is preferably 250 or less.

[0039] In an embodiment of the present invention, from the viewpoint of further exhibiting the effects of the present invention, the amino-silane coupling agent preferably has two or more alkoxy groups bonded to a silicon atom.

[0040] In an embodiment of the present invention, a more significant effect can be obtained when the material constituting the substrate, which is in contact with the main surface satisfying the requirements (1) and (2), contains a metal, a metal oxide, or a glass.

[0041] In an embodiment of the present invention, the ink contains a compound having at least one group selected from a carboxylic acid group, a sulfonic acid group, and a phosphonic acid group, or SO4 2- , PO4 3- , B(C6F5)4 - , SbF6 - , PF6 - , BF4 - , CF3SO3 - , and C4F9SO3 - When the composition contains at least one anion selected from the following, a more significant effect can be obtained.

[0042] The present invention, its components, and embodiments for carrying out the present invention will be described in detail below. In this application, the symbol "to" is used to mean that the numerical values before and after it are included as lower and upper limits.

[0043] [Ink ejection device] The ink ejection device of the present invention is an ink ejection device comprising a substrate, a resin layer laminated so that at least one of its main surfaces is in contact with the substrate, and an ink flow path arranged so that ink flows through the resin layer while contacting a portion of the resin layer, wherein the resin layer contains carbon, oxygen, nitrogen, and silicon, and at least one of the main surfaces satisfies the following requirements (1) and (2):

[0044] (1) The main surface is in contact with the substrate. (2) When the atomic concentrations (atm %) of nitrogen, oxygen, and silicon on the main surface of the resin layer measured by X-ray photoelectron spectroscopy are represented by main surface N, main surface O, and main surface Si, respectively, and the atomic concentrations (atm %) of nitrogen, oxygen, and silicon inside the resin layer are represented by internal N, internal O, and internal Si, respectively, main surface O>internal O and main surface N>0, and the ratio of main surface Si to internal Si, represented by main surface Si / internal Si, is 5 or more.

[0045] Hereinafter, the main surface satisfying the requirements (1) and (2) will also be referred to as the "adhesion main surface (X)." In the present invention, the main surface N, main surface O, main surface Si, and internal N, internal O, and internal Si of the resin layer on the adhesion main surface (X) are measured using X-ray photoelectron spectroscopy (XPS).

[0046] The positional relationship between the substrate, resin layer, and ink flow path provided in the ink ejection device of the present invention, as well as the surface and internal configuration of the resin layer, will be described with reference to Figures 1 and 2. Figure 1 is a cross-sectional view that schematically shows the peripheral portion of a resin layer when only one main surface of the resin layer is in contact with the substrate, specifically, when a resin layer is disposed on the substrate and an ink flow path is provided on the resin layer. Figure 2 is a cross-sectional view that schematically shows the peripheral portion of a resin layer when both main surfaces of the resin layer are in contact with the substrate, specifically, when a resin layer is disposed between the substrates and an ink flow path is provided so as to be in contact with the side surfaces of the substrate and the resin layer.

[0047] In FIG. 1, a resin layer P is formed on a surface BS of a substrate B. The resin layer P has a first main surface PSa and a second main surface PSb, and the surface BS and the first main surface PSa are in contact. The second main surface PSb faces an ink flow path I through which ink flows. An example of a resin layer having the above configuration is a protective layer. The resin layer P is composed of a first surface portion Pa, which is an area starting from the first main surface PSa and extending to a depth of t1 [nm] from the first main surface PSa; a second surface portion Pb, which is an area starting from the second main surface PSb and extending to a depth of t2 [nm] from the second main surface PSb; and an interior portion Pc, which is an area other than the first surface portion Pa and the second surface portion Pb. In the resin layer P shown in FIG. 1, the relationship between the first main surface PSa and the interior portion Pc satisfies the above requirement (2). In other words, only the first main surface PSa is the adhesive main surface (X).

[0048] Note that a resin layer having a main adhesive surface (X) formed on a substrate similar to that shown in FIG. 1 is shown as a protective film 4 in FIGS. 7 and 8, which will be described later, as an example of a specific component in an ink ejection device.

[0049] In Fig. 2, a resin layer P is formed between a substrate B1 and a substrate B2. The resin layer P has a first main surface PSa and a second main surface PSb, with the surface B1S of the substrate B1 contacting the first main surface PSa and the surface B2S of the substrate B2 contacting the second main surface PSb. The side surface of the resin layer P faces an ink flow path I through which ink flows. Examples of the resin layer having the above configuration include an adhesive layer.

[0050] The resin layer P is composed of a first surface portion Pa, which is a region extending from the first main surface PSa to a depth of t1 [nm] from the first main surface PSa; a second surface portion Pb, which is a region extending from the second main surface PSb to a depth of t2 [nm] from the second main surface PSb; and an interior portion Pc, which is a region other than the surface portions Pa and Pb. In the resin layer P shown in FIG. 2, the above requirement (2) is satisfied in the relationship between the first main surface PSa and the interior portion Pc or the relationship between the second main surface PSb and the interior portion Pc. The above requirement (2) may also be satisfied in both the relationship between the first main surface PSa and the interior portion Pc and the relationship between the second main surface PSb and the interior portion Pc. That is, either one of the first main surface PSa and the second main surface PSb may be the adhesive main surface (X), or both may be the adhesive main surfaces (X).

[0051] The resin layer having a main adhesive surface (X) formed between substrates similar to that shown in FIG. 2 is shown as an example of a specific component in an ink ejection device, for example, as adhesive layer 2 in FIGS. 7 and 8 described below, and as adhesive layer 2A in FIGS. 9 and 10.

[0052] Here, the main surface N, main surface O, main surface Si, and internal N, internal O, and internal Si of the resin layer on the adhesive main surface (X) can be measured by XPS, for example, as follows.

[0053] Measurement of the atomic concentrations (atm%) of various elements in a layered sample using XPS is performed by etching the sample from the main surface toward the thickness direction using ion sputtering, irradiating the exposed surface with X-rays at predetermined etching intervals, and measuring the energy of the resulting photoelectrons. This allows for the determination of the atomic concentration (atm%) distribution curve (hereinafter referred to as a "depth profile") of various elements from the main surface toward the thickness direction of the sample. Note that, since H and He cannot be detected in XPS analysis, the atomic concentration (atm%) in this specification refers to the atomic concentration (atm%) of each element among all elements excluding H and He.

[0054] In the resin layer P shown in FIG. 1, the atomic composition is measured by XPS from the first principal surface PSa toward the interior Pc to create a depth profile, thereby confirming that the requirement (2) is satisfied. Here, the first principal surface PSa is the principal surface that contacts the substrate B. Therefore, in order to measure the principal surfaces N, O, and Si using XPS, the resin layer P is separated from the substrate B, and the separated first principal surface PSa is measured by XPS, and a depth profile in the thickness direction is also created.

[0055] The depth profile of the resin layer P thus obtained typically has a pattern in which the atomic composition varies in the thickness direction in the first surface portion Pa, i.e., a region from the first main surface PSa to a depth t1 [nm], and the atomic composition is constant in the thickness direction in the interior Pc, which is at a depth of t1 [nm] or more from the first main surface PSa. In the present invention, the region in the XPS depth profile of the resin layer where the atomic composition is constant in the thickness direction is defined as the interior of the resin layer.

[0056] 1, the atomic composition of the internal Pc and the atomic composition of the first main surface PSa can also be measured from the second main surface PSb side, which is the main surface that does not contact the substrate. That is, the atomic composition is measured by XPS from the second main surface PSb toward the internal Pc to create a depth profile. The region where the atomic composition is constant in the thickness direction is defined as the internal Pc, and the atomic composition in that region is taken as the atomic composition of the internal Pc. Furthermore, since the interface between the first main surface PSa of the resin layer P and the surface BS of the substrate B is clear in the depth profile, the atomic composition at that interface can be taken as the atomic composition of the first main surface PSa of the resin layer P.

[0057] The adhesive main surface (X) in the resin layer P shown in Figure 2 is the first main surface PSa and / or the second main surface PSb, and it is possible to measure the atomic composition of the adhesive main surface (X) and the atomic composition of the internal Pc in the same manner as the first main surface PSa in the resin layer P shown in Figure 1.

[0058] The distribution curve obtained by the XPS depth profile measurement can be created, for example, by plotting the concentration of each element (unit: atm%) on the vertical axis and the etching time (sputtering time) on the horizontal axis. In such an atomic concentration distribution curve with etching time on the horizontal axis, the etching time roughly correlates with the distance (depth) in the thickness direction from the main surface of the resin layer. The distance (depth) in the thickness direction from the main surface of the resin layer to the measurement position can be calculated from the relationship between the etching rate and etching time used in the XPS depth profile measurement.

[0059] The sputtering method used for such XPS depth profile measurements can be the rare gas ion sputtering method, which uses argon (Ar) as the etching ion species. The etching rate can be measured using a thermally oxidized SiO2 film with a known thickness, and the etching depth is often expressed as an equivalent value for the thermally oxidized SiO2 film.

[0060] In the present invention, when XPS depth profile measurement is performed from the adhesive main surface (X) side, the atomic concentrations (atm %) of various elements, such as N, O, and Si, of the adhesive main surface (X) of the resin layer are measured at the first time (depth 0 nm) before starting etching. The adhesive main surface (X) of the resin layer can be obtained as the separation surface on the resin layer side when a substrate with a resin layer is separated into the substrate and the resin layer at the interface between them using, for example, a cutter knife.

[0061] Furthermore, for example, when measuring an XPS depth profile from the side opposite the main adhesive surface (X) of the resin layer, the measured values of the atomic concentrations (atm%) of various elements at the interface with the substrate are the main surface N, main surface O, and main surface Si at the main adhesive surface (X). When measuring an XPS depth profile from the side opposite the main adhesive surface (X) of the resin layer, efficient measurement can be achieved by first scraping off the resin layer from the side opposite the main adhesive surface (X) until the remaining resin layer has an appropriate thickness, preferably about 0.1 to 1 μm, depending on the thickness of the resin layer, and then measuring the XPS depth profile. In this case, internal N, internal O, and internal Si can be measured in the initial part of the measurement.

[0062] For example, when the substrate is made of an inorganic material such as metal, metal oxide, or glass, the interface between the resin layer and the substrate can be identified based on the atomic concentration (atm%) of carbon. For example, the interface between the resin layer and the substrate (the main adhesive surface (X) of the resin layer and the surface of the substrate) can be identified as the range from the position (starting point) where the atomic concentration (atm%) of carbon relative to the atomic concentration (atm%) of carbon inside the resin layer is 0.82 to the position (ending point) where the atomic concentration becomes the detection limit. Note that the starting point may be selected appropriately within the range from the position where the atomic concentration (atm%) of carbon relative to the atomic concentration (atm%) of carbon inside the resin layer is 0.82 to the position where the atomic concentration (atm%) of carbon becomes 0.5.

[0063] That is, when the above measurement method is used, the main adhesive surface (X) in the present invention may be a region having a predetermined thickness. The predetermined thickness is a range from a position where the atomic concentration (atm%) of carbon inside the resin layer is 0.82 to 0.5 to a position where it is below the detection limit, and an example of a thickness of about 5 nm can be mentioned. The region of the main adhesive surface (X) is specifically a region located on the substrate side as part of the surface layer of the resin layer. When the above measurement method is used, the relationship of the atomic concentrations (atm%) of various elements in this region measured by XPS on any plane perpendicular to the thickness direction of the resin layer should satisfy the above (2).

[0064] In addition, when the substrate and the resin layer are firmly bonded, separating the resin layer from the substrate with the resin layer while maintaining the main adhesive surface (X) requires advanced technology. In such cases, a method of measuring an XPS depth profile from the side opposite the main adhesive surface (X) of the resin layer is preferable. Furthermore, whether the resin layer has been successfully separated from the substrate with the resin layer while maintaining the main adhesive surface (X) may be confirmed, for example, by measuring an XPS depth profile starting from the surface of the substrate on the resin layer side after separation. In this method, the results of measuring the XPS depth profile starting from the main adhesive surface (X) of the separated resin layer and the results of measuring the XPS depth profile starting from the surface of the substrate on the resin layer side may be combined to determine whether the main adhesive surface (X) is a region having a predetermined thickness, as described above, and whether requirement (2) is satisfied.

[0065] When an XPS depth profile is measured from the main bonding surface (X), the internal N, internal O, and internal Si can be the values or average values of the N concentration (atm %), O concentration (atm %), and Si concentration (atm %), respectively, measured at at least one point, preferably at least two points in the thickness direction from the point where the atomic composition measured sequentially from the main bonding surface (X) stops changing in the thickness direction.

[0066] For example, in the same manner as described below, the atomic concentrations (atm%) of N, O, and Si are measured on the surface exposed by etching every 10 nm from the main bonding surface (X) in the thickness direction, and if the atomic composition is constant at measurement points 10 nm or more in thickness (depth) from the main bonding surface (X), the average value of the measurements at six points in thicknesses (depths) from 10 nm to 60 nm from the main bonding surface (X) can be used. The etching thickness (etching thickness) may be adjusted appropriately, for example, within the range of 2 to 30 nm.

[0067] Furthermore, when measuring an XPS depth profile from the side opposite to the main adhesive surface (X) of the resin layer, the values or average values of the N concentration (atm %), O concentration (atm %), and Si concentration (atm %) measured at at least one point, preferably at least two points in the thickness direction from the first measurement point to the point where the atomic composition measured sequentially starts to change in the thickness direction can be used as the internal N, internal O, and internal Si, respectively.

[0068] It is preferable that the atomic concentrations of the main surface N, main surface O, main surface Si, and internal N, internal O, and internal Si are measured by the above-mentioned method at at least two locations randomly selected in the surface direction on the main adhesive surface (X) of the resin layer, and that the average of the measured values is used.

[0069] Here, in the present invention, the internal N, internal O, and internal Si in the resin layer measured by the above-mentioned method are actually atomic concentrations (atm%) measured in a portion of the interior of one main surface side, but the entire interior of the resin layer except for the surface layer is considered to have the same composition, so the above-mentioned measurement method can be applied.

[0070] Below is an example of specific conditions for XPS depth profile measurement applicable to the composition analysis of the main surface N, main surface O, main surface Si, and internal N, internal O, and internal Si of the resin layer according to the present invention. An example of XPS depth profile measurement performed under these conditions is shown in Figure 11A (Example 1) in the Examples.

[0071] Analytical equipment: ULVAC-PHI QUANTERA SXM ·X-ray source: Monochromatic Al-Kα 15kV 25W Sputter ions: Ar (1 keV) Depth profile: Measurements are repeated at predetermined thickness intervals in SiO2 equivalent sputtering thickness to obtain a depth profile. The thickness interval is set to 10.8 nm (data is obtained every 10.8 nm in the depth direction). Quantitation: The background was determined by the Shirley method, and quantitation was performed using the relative response factor method from the obtained peak area. Data was processed using MultiPak manufactured by ULVAC-PHI.

[0072] Here, the requirement (2) for the adhesive main surface (X) consists of three requirements: (2-1) main surface O>inner O, (2-2) main surface N>0, and (2-3) main surface Si / inner Si≧5.

[0073] In the requirement (2-1), the principal surface O is greater than the internal O. The relationship between the principal surface O and the internal O is preferably such that the ratio of the principal surface O to the internal O, expressed as principal surface O / internal O, is 2 or greater. It is more preferable that the principal surface O / internal O is 7.5 or greater. There is no particular upper limit to the principal surface O / internal O, but it can be, for example, 100 or less. A higher oxygen atom concentration in the adhesive principal surface (X) than in the interior of the resin layer means that there are sufficient chemical bonds mediated by oxygen at the interface between the resin layer and the substrate, thereby achieving high adhesiveness.

[0074] In the requirement (2-2), the principal surface N>0. The nitrogen atom concentration in the adhesive principal surface (X) exceeding 0 means that nitrogen atoms are present on the surface of the resin layer on the adhesive principal surface (X) side, thereby providing adhesiveness. The nitrogen atoms are, for example, amino groups, preferably -NH2 or -NH3 + This acts as described above and has the ability to trap ink components such as water and acid, thereby improving the ink resistance of adhesive properties.

[0075] In the requirement (2-3), the ratio of main surface Si / internal Si is 5 or more. The ratio of main surface Si / internal Si is preferably 6 or more, and more preferably 8 or more. There is no particular upper limit to the ratio of main surface Si / internal Si, and it may be infinite, with no internal Si being detected. The silicon atom concentration at the adhesive main surface (X) being 5 times or more higher than that inside the resin layer means that there are sufficient chemical bonds via siloxane bonds at the interface between the resin layer and the substrate, thereby obtaining high adhesion.

[0076] The specific value of the Si content of the main surface is, for example, preferably 1.0 to 10.0 atm%, more preferably 1.1 to 9.8 atm%, and even more preferably 1.3 to 9.5 atm%. If the Si content of the main surface is 1.0 atm% or more, the amount of siloxane bonds at the interface is sufficient, making it easy to obtain high adhesiveness. If the Si content of the main surface exceeds 10.0 atm%, the balance of the atomic concentrations on the adhesive main surface (X) is lost, which tends to decrease adhesiveness and durability to ink.

[0077] In relation to the requirement (2-2), it is preferable that the ratio of main surface N / internal N is 1.5 or more, i.e., the requirement (3) of the present invention is satisfied. It is more preferable that the ratio of main surface N / internal N is 2 or more. There is no particular upper limit to the ratio of main surface N / internal N, but it can be, for example, 100 or less. The nitrogen atom concentration at the adhesive main surface (X) being at least twice as high as that inside the resin layer means that a sufficient number of nitrogen atoms are present on the surface of the resin layer on the adhesive main surface (X) side, thereby obtaining high adhesiveness.

[0078] In relation to the requirement of (2-2), the bonding surface (X) is such that the spectrum obtained by the XPS analysis of the bonding state of nitrogen atoms is -NH2 or -NH3 + The bond state analysis by XPS can be carried out, for example, by the following method.

[0079] XPS can analyze the bonding state of each element. In the present invention, the bonding state of nitrogen atoms on the main bonding surface (X) is measured by the bonding state analysis of XPS, and -NH2 and -NH3 + The amount of nitrogen atoms present is confirmed. An example of specific conditions for bonding state analysis by XPS that can be applied to the present invention is shown below. A specific example of a spectrum obtained by measuring the bonding state of nitrogen atoms under these conditions is shown in Figure 12A (Example 2) in the Examples.

[0080] Analytical equipment: ULVAC-PHI QUANTERA SXM ·X-ray source: Monochromatic Al-Kα 15kV 25W Pass energy: 55 eV Data processing: Using MultiPak manufactured by ULVAC-PHI Elemental composition analysis: Background processing is performed using the Shirley method, and the elemental composition is quantified using the relative sensitivity coefficients from the obtained peak areas.

[0081] -NH2 and -NH3 + The peaks and peak areas can be determined by the following method. First, the peak shift due to charge is corrected from the binding energy of the carbon 1s peak, and then the peaks related to nitrogen atoms (shown by solid lines in the figure) are separated into peaks of each state. In Figure 12A, the peaks related to nitrogen atoms can be separated into two state peaks (a peak showing a maximum at 399.5 eV and a peak showing a maximum at 401.8 eV). The state of the nitrogen atoms in each peak is identified based on the binding energy. In Figure 12A, the peak showing a maximum at 399.5 eV is the peak of -NH2, and the peak showing a maximum at 401.8 eV is the peak of -NH3. + This is the peak.

[0082] In addition, -NH2 and -NH3 + The bond energy is the literature value "Completely revised version of the effects and usage of silane coupling agents (November 15, 2012, 1st edition)" (-NH2; 399.0 eV, -NH3 + The peak FWHM (full width at half maximum) was determined to be within the range of 1.0 to 2.5, and the peaks of -NH2 and -NH3 were determined to be within the range of 1.0 to 2.5. + Fitting is performed under the condition that the FWHM (full width at half maximum) of the peaks is equal, and the area of each peak is calculated. + From the peak areas of each, the nitrogen atoms derived from -NH2 and -NH3 relative to the total amount of nitrogen atoms were calculated. + The proportion of nitrogen atoms derived from the

[0083] Preferred embodiments of the present invention will be described below with reference to the drawings. However, the scope of the present invention is not limited to the illustrated examples. The components shown in these drawings can be modified as appropriate without departing from the spirit of the present invention. For the sake of convenience, the present specification defines the direction in which ink is ejected from the ink ejection device as "downward" and the direction opposite to "downward" as "upward." Furthermore, arrows in the ink flow paths in the drawings indicate the direction in which ink flows.

[0084] FIG. 3 is a perspective view showing an example of an embodiment of an ink ejection device of the present invention, and FIG. 4 is a bottom view of the ink ejection device shown in FIG. 3. When recording on a recording medium, the bottom surface of the ink ejection device and the recording surface of the recording medium are positioned opposite each other. Specifically, the recording medium is positioned so that its recording surface is located below the ink ejection device and in a direction perpendicular to the direction in which the ink is ejected, and inkjet recording is performed while the recording medium is being transported. In the following explanation, for convenience, the direction in which the recording medium is transported will be referred to as the front-to-rear direction, and the direction on the recording surface perpendicular to the direction in which the recording medium is transported will be referred to as the left-to-right direction.

[0085] Fig. 5 is a cross-sectional view taken in the left-right direction of the lower part of the ink discharge device shown in Fig. 3. Fig. 6 is an exploded perspective view of the head chip of the ink discharge device shown in Fig. 3. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6, and Fig. 8 is an enlarged view of the part surrounded by the dashed line in Fig. 7.

[0086] 3, 4, 5, etc., the ink ejection device 100 of this embodiment includes a head chip 10A and a manifold 5 that stores ink to be supplied to the head chip 10A. The head chip 10A includes a shear-mode actuator Ac and a nozzle plate 20 having nozzles 21 for ejecting ink from the actuator Ac to the outside of the ink ejection device 100. The actuator Ac includes a laminated substrate in which a flow path substrate 3A, an adhesive layer 2X, and a pressure chamber substrate 1A are laminated in this order from the manifold 5 side, and the pressure chamber substrate 1A of the actuator Ac is bonded to the nozzle plate 20 via an adhesive layer 2.

[0087] Both adhesive layer 2X and adhesive layer 2 are resin layers whose main surfaces are in contact with the surface of the substrate. As will be described later, adhesive layer 2X has its side surfaces covered with protective film 4 (see Figure 7), and therefore does not come into contact with the ink flow path. On the other hand, adhesive layer 2 has its side surfaces in contact with the ink flow path. Adhesive layer 2 is an adhesive layer that satisfies the requirements of the present invention, for example, in that at least one of its main surfaces satisfies requirement (2) above. Furthermore, protective film 4 that covers the side surfaces of adhesive layer 2X is typically a resin layer. Hereinafter, in this specification, unless otherwise specified, both "adhesive layer" and "protective film" are made of a resin layer.

[0088] As will be described later, it is preferable that the pressure chamber substrate 1A is made of a piezoelectric material such as PZT, and the nozzle plate 20 is made of a metal. Considering the constituent materials of the pressure chamber substrate 1A and the nozzle plate 20, it is preferable that at least the main surface of the adhesive layer 2 that contacts the nozzle plate 20 is the adhesive main surface (X), and it is more preferable that both main surfaces are adhesive main surfaces (X).

[0089] As described above, the adhesive layer 2 is a resin layer. In this specification, a "resin layer" refers to a layer primarily composed of a resin. The resin contained in the resin layer can be a thermoplastic resin or a cured resin. A cured resin refers to a resin obtained by curing a curable compound by reacting with light or heat to polymerize it. The resin layer may contain inorganic or organic components other than resin. Examples of components other than resin include additives and fillers added to the resin layer for various purposes. The content of the resin contained in the resin layer can be, for example, approximately 50% by mass or more of the total amount of the resin layer. In this specification, the term "resin" includes plasticizers in thermoplastic resins and components involved in the polymerization (curing) of curable compounds in cured resins, such as curing agents, polymerization initiators, catalysts, chain transfer inhibitors, and polymerization inhibitors.

[0090] The resin layer according to the present invention contains carbon, oxygen, nitrogen, and silicon. These elements may be contained in either the resin contained in the resin layer or a component other than the resin. The resin layer according to the present invention typically contains hydrogen.

[0091] Specific examples of thermoplastic resins that can be used as the resin contained in the resin layer include polyolefin resins, polystyrene resins, polyamide resins, polyimide resins, polyester resins, acrylic resins, polyurethane resins, polyvinyl chloride resins, vinyl acetate resins, ethylene vinyl acetate resins, epoxy resins, phenolic resins, melamine resins, polycarbonate resins, polyacetal resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, styrene-acrylonitrile copolymers (AS resins), styrene-(meth)acrylic acid copolymers, styrene-methyl methacrylate copolymers, acrylonitrile-butadiene-styrene copolymers (ABS resins), and methyl methacrylate-butadiene-styrene copolymers (MBS resins).

[0092] Specific examples of cured resins that can be used as the resin contained in the resin layer include phenolic resins, epoxy resins, acrylic resins, urethane resins, melamine resins, alkyd resins, unsaturated polyester resins, urea resins, and polyparaxylylene resins.

[0093] These resins all contain carbon and hydrogen, and some types further contain oxygen or nitrogen. Even if a resin does not typically contain oxygen, nitrogen, or silicon, it can be made into a resin containing oxygen, nitrogen, and silicon by introducing a substituent or modifying it.

[0094] Here, when a resin layer containing a thermoplastic resin as a resin is formed on a substrate or between substrates, typically, the thermoplastic resin itself is dissolved in a solvent or the like as a liquid composition, which is applied to the substrate and dried to form a resin layer. When a resin layer is formed between substrates, the liquid composition is applied to one substrate, the other substrate is laminated on the coating film of the applied liquid composition, and the coating film is then dried to form a resin layer. When a component other than the resin is contained in the resin layer, the component other than the resin is blended into the liquid composition.

[0095] Furthermore, when a resin layer containing a cured resin as the resin is formed on or between substrates, typically, a liquid composition containing a curable compound and a component involved in the polymerization (curing) of the curable compound selected from a curing agent, a polymerization initiator, a catalyst, a chain transfer inhibitor, and a polymerization inhibitor, etc., as needed, and further containing a solvent, etc., is applied to the substrate and cured by heat or light to form a resin layer. When a resin layer is formed between substrates, the liquid composition is applied to one substrate, the other substrate is laminated on the coating film of the applied liquid composition, and the coating film is cured by heat or light to form a resin layer. When a component other than the resin is contained in the resin layer, the component other than the resin is blended into the liquid composition. Hereinafter, the curable compound and the component involved in the polymerization (curing) of the curable compound are collectively referred to as "resin components."

[0096] In the above, the solvent used in preparing the liquid composition used to form the resin layer, the method for applying the liquid composition, and the conditions for drying and curing the coating are appropriately selected depending on the type of resin. The thickness of the resin layer is appropriately selected depending on the type of resin, application, location, etc.

[0097] When a resin layer is formed on or between substrates using a thermoplastic resin or a cured resin in this manner, in order for the resin layer to have a main surface that satisfies (1) and (2), it is preferable that the liquid composition contains, as a component other than the resin, a component having at least nitrogen and silicon that will be unevenly distributed near the interface between the resin layer and the substrate when the resin layer is formed. Examples of components that will be unevenly distributed near the interface between the resin layer and the substrate when the resin layer is formed include coupling agents, and examples of coupling agents having nitrogen and silicon include amino-based silane coupling agents.

[0098] [Amino-based silane coupling agents] The amino-based silane coupling agent is preferably, for example, a compound having a structure represented by the following formula (I). Formula (I) R 1 4-n Six n

[0099] R 1represents a monovalent organic group, at least one of which contains at least one of a primary amino group, a secondary amino group, a tertiary amino group, an acid-neutralizing group of an amino group, and a quaternary ammonium salt group. X represents a monovalent hydrolyzable group. n represents an integer of 1 to 3. R 1 If there are two or more, there are two or more R 1 may be the same or different.

[0100] Examples of the monovalent hydrolyzable group represented by X include an alkoxy group, an acyloxy group, a ketoxime group, an alkenyloxy group, an amino group, an aminooxy group, an amide group, an isocyanato group, and a halogen atom. When n is 2 or more, the multiple Xs may be the same or different.

[0101] Preferred hydrolyzable groups include alkoxy groups and halogen atoms, with alkoxy groups having 1 to 4 carbon atoms being particularly preferred. More preferred amino silane coupling agents represented by formula (I) include amino silane coupling agents having a structure represented by the following formula (II). The amino silane coupling agent represented by formula (II) is a compound in which the hydrolyzable group X in formula (I) is an alkoxy group (number of carbon atoms: 1 to 4).

[0102] [ka]

[0103] In formula (II), R 2 and R 3 represents an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. n represents an integer of 1 to 3, and is preferably 2 or 3.

[0104] In formula (II), R 4represents either an alkylene group having 1 to 20 carbon atoms or an arylene group. Examples of the alkylene group having 1 to 20 carbon atoms include a methylene group, an ethylene group, a propane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an octane-1,8-diyl group, a 2-methyl-hexane-1,6-diyl group, and a decane-1,10-diyl group. Examples of the arylene group include a phenylene group and a naphthylene group. These groups may be substituted with a halogen, a hydroxyl group, or the like.

[0105] In formula (II), R 5 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group. Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a tert-pentyl group, a hexyl group, an isohexyl group, an octyl group, a 2-ethylhexyl group, a tert-octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the aryl group include a phenyl group and a naphthyl group. These groups may be further substituted with an aryl group, a heterocycle, an amino group, an amido group, an imino group, a halogen atom, a hydroxy group, or the like.

[0106] Specific examples of amino-based silane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, N-ethyl-3-aminopropyltrimethoxysilane, N-butyl-3-aminopropyltrimethoxysilane, and N,N-dimethyl-3-aminopropyltrimethoxysilane. propyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, N,N-dibutyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-3-aminopropyltrimethoxysilane hydrochloride, octadecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, tetradecyldimethyl(3-trimethoxysilylpropyl)ammonium chloride, N-trimethoxysilylpropyl-N,N,N-tri-n-butylammonium bromide, N-trimethoxysilylpropyl-N,N,N-tri-n-butylammonium chloride, N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride, and the like.

[0107] Among these, the amino silane coupling agent preferably has a molecular weight per nitrogen atom of 250 or less. Also preferred are amino silane coupling agents having two or more alkoxy groups bonded to silicon atoms, such as compounds represented by the above formula (II) where n is 2 or more.

[0108] Examples of amino-based silane coupling agents that satisfy these conditions include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-methyl-3-aminopropyltrimethoxysilane, N-ethyl-3-aminopropyltrimethoxysilane, N-butyl-3-aminopropyltrimethoxysilane, N,N-dimethyl-3-aminopropyltrimethoxysilane, and N,N-diethyl-3-aminopropyltrimethoxysilane.

[0109] Furthermore, among these, amino-based silane coupling agents having an -NH2 group at the terminal are preferred, with 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltriethoxysilane being particularly preferred.

[0110] By incorporating an amino-based silane coupling agent into the resin composition described below, the hydrolyzable groups of the amino-based silane coupling agent are hydrolyzed during the formation of the resin layer to generate silanol groups, which then undergo dehydration co-condensation with OH groups on the surface of the substrate to generate "substrate-O-Si" bonds. On the other hand, in a preferred embodiment, the terminal amino groups are -NH2 or -NH3 + It is believed that the above-mentioned functions are achieved by the presence of the ions in the vicinity of the interface.

[0111] When forming a resin layer having a main surface that satisfies the above requirements (1) and (2), the content of the amino silane coupling agent relative to the total amount of the resin composition is preferably within the range of 0.01 to 10% by mass, more preferably within the range of 0.1 to 5% by mass. If the content of the amino silane coupling agent is within the above range, the resin layer whose main surface is in contact with the substrate can easily satisfy requirement (2), and preferably also requirement (3), without affecting the film-forming properties or crosslinked structure of the resin layer.

[0112] When the resin layer is an adhesive layer, the resin contained in the resin layer is preferably an epoxy resin. When the resin layer is a protective layer, examples of the resin include a polyimide resin and a polyparaxylylene resin. Hereinafter, an embodiment in which the resin layer contains an epoxy resin will be described.

[0113] When the resin layer according to the present invention contains an epoxy resin, the resin layer is formed using, for example, a resin component containing an epoxy compound and a curing agent, which are raw materials for the epoxy resin, and a resin composition containing the amino-silane coupling agent as a component other than the resin component. In the present invention, the "resin composition" refers to a composition consisting of the solid raw materials constituting the resin layer, and does not contain a solvent. When the resin composition is a liquid composition with a viscosity sufficient to form a coating film on a substrate, it is not necessary to add a solvent. When the resin composition is solid or has such a high viscosity that it is difficult to form a coating film on a substrate, a solvent is added to form a liquid composition with an appropriate viscosity, which is used to form the resin layer.

[0114] Epoxy resins are resins obtained by using an epoxy compound having multiple epoxy groups as a curable compound and curing the epoxy compound with the action of a curing agent. When forming a resin layer using an epoxy resin, a resin composition containing a resin component for forming the epoxy resin and a component other than the resin component, such as an amino-based silane coupling agent, is used. Below, each component contained in the resin composition (hereinafter simply referred to as "resin composition" or "epoxy resin composition") when forming a resin layer using an epoxy resin is described.

[0115] (epoxy compounds) The epoxy compound is not particularly limited as long as it has at least two epoxy groups in the molecule, and can be appropriately selected depending on the purpose. For example, in order to obtain an epoxy resin having a crosslinked structure, the number of epoxy groups in the epoxy compound is preferably three or more, more preferably four or more. In addition, by using an epoxy compound with an epoxy equivalent of preferably 300 or less, more preferably 220 or less, an epoxy resin with a dense structure and a short distance between crosslink points can be easily obtained.

[0116] Examples of epoxy compounds include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds, polyglycidyl ether compounds of polynuclear polyhydric phenol compounds, polyglycidyl ethers of polyhydric alcohols; polyglycidyl ether compounds of polyols obtained by adding polyalkylene oxide to mononuclear polyhydric phenol compounds, polynuclear polyhydric phenol compounds, or polyhydric alcohols; homopolymers or copolymers of glycidyl esters of aliphatic, aromatic, or alicyclic polybasic acids and glycidyl methacrylate; epoxy compounds having a glycidylamino group, epoxy compounds of cyclic olefin compounds, heterocyclic compounds, or those internally crosslinked with prepolymers of terminal isocyanates of these epoxy resins, or compounds polymerized with polyvalent active hydrogen compounds (e.g., polyhydric phenols, polyamines, carbonyl group-containing compounds, polyphosphate esters, etc.). These may be used alone or in combination of two or more.

[0117] Examples of the mononuclear polyhydric phenol compounds include hydroquinone, resorcinol, pyrocatechol, and phloroglucinol.

[0118] Examples of the polynuclear polyhydric phenol compounds include dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis(ortho-cresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis(ortho-cresol), tetrabromobisphenol A, 1,3-bis(4-hydroxycumylbenzene), 1,4-bis(4-hydroxycumylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolac, orthocresol novolac, ethylphenol novolac, butylphenol novolac, octylphenol novolac, resorcinol novolac, and terpene phenols.

[0119] Examples of the polyhydric alcohols include ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, dicyclopentadiene dimethanol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and bisphenol A-ethylene oxide adducts.

[0120] Examples of the homopolymers or copolymers of glycidyl esters of aliphatic, aromatic, or alicyclic polybasic acids and glycidyl (meth)acrylate include homopolymers or copolymers of glycidyl esters of aliphatic, aromatic, or alicyclic polybasic acids and glycidyl (meth)acrylate, such as maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and endomethylenetetrahydrophthalic acid.

[0121] Examples of the epoxy compound having a glycidylamino group include N,N-diglycidylaniline, bis(4-(N-methyl-N-glycidylamino)phenyl)methane, diglycidyl orthotoluidine, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)-2-methylaniline, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)aniline, and N,N,N',N'-tetra(2,3-epoxypropyl)-4,4'-diaminodiphenylmethane.

[0122] Examples of the epoxy compounds of the cyclic olefin compounds include vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, etc. Examples of the epoxidized conjugated diene polymers include epoxidized polybutadiene, epoxidized styrene-butadiene copolymers, etc.

[0123] Examples of the heterocyclic compound include triglycidyl isocyanurate.

[0124] Among these, polyglycidyl ethers of polynuclear polyhydric phenol compounds, polyglycidyl ethers of polyhydric alcohols, alkylene oxide-modified epoxy resins of polynuclear polyhydric phenol compounds, and epoxy compounds having a glycidylamino group are preferred from the viewpoint of workability during resin layer formation, adhesion, solvent resistance, and other performance properties of the cured product.

[0125] Commercially available epoxy compounds may be used, including the jER (registered trademark) series (manufactured by Mitsubishi Chemical Corporation), the EPPN series, and the EOCN series (manufactured by Nippon Kayaku Co., Ltd.).

[0126] The content of the epoxy compound relative to the total amount of the epoxy resin composition can be, for example, within a range of 25 to 99% by mass, and more preferably within a range of 40 to 95% by mass. By ensuring that the content of the epoxy compound is within the above range, a crosslinked structure is formed within the resin composition, thereby improving resistance to ink penetration.

[0127] (hardening agent) Curing agents are classified into polyaddition curing agents and catalytic curing agents. Polyaddition curing agents are compounds that have multiple groups that are reactive with epoxy groups, such as carboxyl groups, hydroxyl groups, amino groups with active hydrogen, sulfhydryl groups (-SH), and acid anhydride groups. Catalytic curing agents are compounds that promote reactions between epoxy compounds, such as tertiary amines, imidazole compounds, and phosphorus compounds.

[0128] In the present invention, the curing agent is H + It is preferable that the curing agent has an adduct with a pKa of 3 or more. In this specification, unless otherwise specified, "pKa" refers to the pKa in water at 25°C. The pKa value in water at 25°C can be measured from electrical conductivity or the like.

[0129] where H + It is preferable to use a curing agent whose adduct has a pKa of 3 or more, since this can accelerate the reaction of the epoxy compound and the amino-based silane coupling agent. + The upper limit of the pKa of the adduct is not particularly limited, but can be set to approximately 50. + As the curing agent having an adduct with a pKa of 3 or more, a nitrogen-containing compound is preferred.

[0130] H + Specific examples of curing agents with an adduct pKa of 3 or higher include polyamine compounds with multiple amino groups containing active hydrogen for polyaddition-type curing agents, and tertiary amines and imidazole compounds for catalytic-type curing agents. +As the curing agent having an adduct with a pKa of 3 or more, a nitrogen-containing catalyst type curing agent is preferred, and an imidazole compound is particularly preferred.

[0131] The term "imidazole compound" refers to a group of compounds including imidazole and its derivatives. Preferred imidazole compounds are those in which at least one of the 1st, 2nd, and 4th positions of the imidazole is substituted with a substituent. Examples of the substituent include an alkyl group, an aryl group, and an aralkyl group.

[0132] Examples of the alkyl group include branched and linear alkyl groups such as methyl, ethyl, isopropyl, t-butyl, hexyl, dodecyl, undecyl, pentadecyl, and heptadecyl groups, and cyclic alkyl groups such as cyclopentyl and cyclohexyl groups, which may have a substituent.

[0133] Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonamido group, a sulfamoyl group, a ureido group, an acyl group, an acyloxy group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a cyano group, a nitro group, a sulfo group, and a hydroxy group.

[0134] Examples of the aryl group include a phenyl group and a naphthyl group, which may be substituted with the substituents mentioned for the alkyl group.

[0135] The aralkyl group is an alkyl group substituted with an aryl group, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group, which may be substituted with the substituents mentioned for the alkyl group.

[0136] Specific examples of the imidazole compound include imidazole, 2-methylimidazole, 4-methylimidazole, 2-heptadecylimidazole, 4-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. -phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazole] midazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl Examples of the isocyanuric acid adduct include, but are not limited to, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole.

[0137] Among these, imidazole compounds having an alkyl group or an aryl group at the 4-position are preferred, such as 2-ethyl-4-methylimidazole, 4-methylimidazole, 4-heptadecylimidazole, 4-phenylimidazole, 2-phenyl-4-methylimidazole, etc. These imidazole compounds may be used alone or in combination of two or more.

[0138] Commercially available imidazole compounds may be used. Specific examples of commercially available imidazole compounds include SIZ, 2MZ-H, C11Z, C17Z, 1.2DMZ, 2E4MZ, 2PZ, 2PZ-PW, 2P4MZ, 1B2MZ, 1B2PZ, 2MZ-CN, C11Z-CN, 2E4MZ-CN, 2PZ-CN, C11Z-CNS, 2PZCNS-PW, 2MZ-A, 2MZA-PW, C11Z-A, 2E4MZ-A, 2MA-OK, 2MAOK-PW, 2PZ-OK, 2PHZ-PW, and 2P4MHZ-PW, all of which are from the Curesol series manufactured by Shikoku Chemicals Corporation.

[0139] The content of the curing agent relative to the total amount of the epoxy resin composition is preferably within a range of 3 to 15% by mass, more preferably within a range of 5 to 11% by mass, which is preferable because the content of the curing agent within the above range can improve ink resistance while promoting the crosslinking reaction of the resin without inhibiting the construction of a crosslinked structure.

[0140] As described above, the epoxy resin composition contains H as a curing agent. + It is preferable to use a curing agent whose adduct has a pKa of 3 or more. + When using a curing agent whose adduct has a pKa of 3 or more, further H + A curing agent having an adduct pKa of less than 3 may be used. However, all of the curing agents contained in the epoxy resin composition are H + It is preferable that the curing agent has a pKa of 3 or more. + It is preferable to contain a curing agent whose adduct has a pKa of 3 or more in the range of 3 to 15 mass %.

[0141] As mentioned above, H + As the curing agent having an adduct pKa of 3 or more, a nitrogen-containing catalyst-type curing agent, particularly an imidazole compound, is preferred. + When a nitrogen-containing catalyst type curing agent, such as an imidazole compound, is used as a curing agent having a pKa of 3 or more, in addition to the nitrogen-containing catalyst type curing agent, H +A polyaddition type curing agent having an adduct pKa of 3 or more, such as a polyamine compound, may also be used.

[0142] (Other resin components) The epoxy resin composition may contain, as resin components other than the epoxy compound and the curing agent, a polymerization inhibitor, a chain transfer inhibitor, etc., within the range that does not impair the effects of the present invention.

[0143] (Amino-based silane coupling agent) The epoxy resin composition used to form the resin layer containing an epoxy resin preferably contains the amino-silane coupling agent described above, so that the resulting resin layer can satisfy the above-mentioned condition (2) on either of the main surfaces that contact the substrate.

[0144] (Other ingredients) The epoxy resin composition may further contain various additives or other solid components such as fillers, provided that the effects of the present invention are not impaired. Examples of additives include surfactants, ultraviolet absorbers, antioxidants, rheology control agents, antistatic agents, and photopolymerization initiators. Examples of fillers include carbonates such as calcium carbonate and magnesium carbonate; sulfates such as barium sulfate and magnesium sulfate; silicates such as aluminum silicate and zirconium silicate; oxides such as silicon oxide, iron oxide, titanium oxide, aluminum oxide, and zinc oxide; kaolin, talc, asbestos powder, quartz powder, mica, and glass fiber. Furthermore, conductive particles may be used as a filler, if necessary.

[0145] The other solid components may contain oxygen atoms, silicon atoms, or nitrogen atoms, but typically, a small amount of the other solid components is uniformly dispersed throughout the resin layer. In such cases, the amino silane coupling agent and the other solid components may be combined to satisfy the requirement (2) above.

[0146] The method for forming a resin layer containing an epoxy resin using the above-mentioned epoxy resin composition is not particularly limited. When the epoxy resin composition is a liquid composition, it is applied directly to a substrate, or when the epoxy resin composition is not liquid, it is made into a liquid composition using a solvent, and the liquid composition is applied to a substrate to form a coating film, and if necessary, another substrate is laminated on the coating film, and the coating film is cured by heat or light. The conditions for curing by heat or light are appropriately adjusted depending on the types of epoxy compound and curing agent used.

[0147] The above has described the epoxy resin composition, but even in the case of a resin composition containing a resin other than an epoxy resin, for example, an amino-based silane coupling agent or the like can be incorporated into the resin composition so that the main adhesive surface (X) is obtained in the resulting resin layer, and the resin layer according to the present invention can be formed by carrying out the same operation as when a resin layer is usually formed on or between substrates using the resin.

[0148] In the ink ejection device 100, the actuator Ac has a laminated substrate that includes one flow path substrate 3A and one pressure chamber substrate 1A, which are joined together with an adhesive layer 2X. The configuration of the actuator Ac is not limited to this, and the actuator Ac may have multiple flow path substrates and pressure chamber substrates, or may further have substrates other than the flow path substrates and pressure chamber substrates.

[0149] When the adhesive layer provided for bonding the substrates has a portion that comes into contact with the ink flowing through the ink flow path, the adhesive layer preferably satisfies the requirements of the present invention, but does not necessarily have to. In other words, in the ink-jet device of the present invention, it is sufficient that any one of the resin layers satisfies the requirements of the present invention, and as long as adhesive layer 2 is a resin layer that satisfies the requirements of the present invention, the other resin layers that have portions that come into contact with the ink do not necessarily have to meet the requirements of the present invention. However, it is preferable that all of the resin layers that have a main surface that comes into contact with the substrate and that have portions that come into contact with the ink satisfy the requirements of the present invention.

[0150] Although it depends on the type of resin layer, it is preferable that the main surface of the resin layer be an adhesive main surface (X) that satisfies the requirement (2), particularly when the material constituting the substrate that is in contact with the main surface of the resin layer contains a metal, a metal oxide, or glass.

[0151] Substrates made of metal, metal oxide, and glass have OH groups on their surfaces, and the OH groups can react with, for example, an amino-silane coupling agent preferably contained in a resin composition used to form a resin layer on the substrate, thereby improving adhesion at the interface between the substrate and the resin layer.

[0152] As will be described later, the constituent material of the nozzle plate 20 is preferably metal, and from the above viewpoint, in the ink ejection device of the present invention, it is preferable that the main surface of the adhesive layer 2 that bonds the actuator Ac and the nozzle plate 20 to the nozzle plate 20 is the main adhesive surface (X).

[0153] The flow path substrate 3A provided in the actuator Ac is a wiring substrate having wiring electrodes 33A and 33B (see FIG. 6), and the ink discharge device 100 has, above the actuator Ac, a flexible substrate 8 (see FIG. 6) connected to the wiring electrodes of the flow path substrate 3A, and a drive circuit board (not shown) connected to the flexible substrate 8. The ink discharge device 100 has a housing 6 that houses lower members (nozzle plate 20, actuator Ac, manifold 5, etc.), and a cover member 7 attached to the housing 6 so as to cover upper members (flexible substrate 8, drive circuit board, etc.).

[0154] The housing 6 is a member formed by die-casting, for example, from aluminum, and is formed long in the left-right direction. The bottom surface of the housing 6 has an opening so that the nozzle plate 20 is exposed to the outside. Mounting holes 68 are formed at both left and right ends of the housing 6, respectively, for mounting the housing 6 to the printer main body.

[0155] The lower end of the manifold 5 is attached and fixed to the outer edge of the upper surface 3Sb of the flow path substrate 3A by adhesive. This adhesion can be achieved, for example, by forming an adhesive layer. In this case, if the adhesive layer has a portion that directly contacts the ink flow path, for example, a side surface that directly contacts the ink flow path, one or both of the main surfaces of the adhesive layer can be used as the main adhesive surface (X).

[0156] The manifold 5 is a member molded from, for example, resin, and is disposed above the flow path substrate 3A of the actuator Ac. The manifold 5 has the function of storing ink to be supplied to the actuator Ac. Specifically, as shown in Fig. 3 and other figures, the manifold 5 is formed from, for example, a resin material and is elongated in the left-right direction. The manifold 5 includes a hollow main body 52 that forms the ink storage section 51, and first to third ink ports 53 to 55 that form the ink flow paths. The ink storage section 51 is further divided into two sections, an upper first liquid chamber 51a and a lower second liquid chamber 51b, by a filter F that removes foreign matter from the ink.

[0157] The first ink port 53 is connected to the upper right end of the first liquid chamber 51a and is used to introduce ink into the ink storage section 51. A first joint 81a is fitted onto the tip of the first ink port 53. The second ink port 54 is connected to the upper left end of the first liquid chamber 51a and is used to remove air bubbles inside the first liquid chamber 51a.

[0158] A second joint 81b is fitted onto the tip of the second ink port 54. The third ink port 55 is connected to the upper left end of the second liquid chamber 51b and is used to remove air bubbles from the second liquid chamber 51b. A third joint 82a is fitted onto the tip of the third ink port 55. The manifold 5 may further have a fourth ink port (not shown) as an ink outlet for discharging surplus ink that is not used in printing and is discharged from the actuator Ac to the outside of the ink discharge device 100.

[0159] The nozzle plate 20 is disposed below the pressure chamber substrate 1A of the actuator Ac. The material constituting the nozzle plate 20 can be selected from materials that have high mechanical strength, ink resistance, and excellent dimensional stability, and various materials such as inorganic materials and resin films can be used. The material constituting the nozzle plate 20 is preferably an inorganic material such as a metal oxide or metal, more preferably a metal such as iron (e.g., stainless steel (SUS)), aluminum, nickel, or stainless steel, and particularly preferably stainless steel (SUS). The nozzle plate 20 has nozzles 21A and 21B that serve as ink ejection holes when ink is ejected from the pressure chamber substrate 1A toward a recording medium.

[0160] As shown in FIG. 6, the pressure chamber substrate 1A of the actuator Ac is a substantially rectangular prism-shaped member that is elongated in the left-right direction and has two channel rows, row A and row B. Here, the rear channel row shown in FIG. 6 is row A, and the front channel row is row B. Each channel row is composed of drive channels 11A, 11B and dummy channels 12A, 12B that are alternately arranged. The partition between the adjacent drive channel 11A or 11B and the dummy channel 12A or 12B is a drive wall 13 made of a piezoelectric material.

[0161] The piezoelectric material preferably contains a perovskite-type compound such as barium titanate (BaTiO3) and lead zirconate titanate ([Pb(Zr·Ti)O3], also referred to as "PZT" in this specification), and preferably contains mainly PZT. The molar ratio of Zr to Ti in PZT is preferably Zr / Ti=30 / 70 to 70 / 30. "Containing mainly PZT" means that PZT accounts for 85 mass% or more of the total amount of the piezoelectric material.

[0162] To improve the performance of the piezoelectric material, donor ions may be added to PZT, and examples of donor ions include metal ions such as lanthanum (La), niobium (Nb), tantalum (Ta), tungsten (W), aluminum (Al), and strontium (Sr), and it is preferable to include one or more ions selected from the group consisting of La, Nb, Ta, and W. It is preferable to include one or more metal ions selected from the group consisting of iron (Fe), cobalt (Co), and manganese (Mn) as acceptor ions.

[0163] In this specification, a drive channel is a channel that serves as an ink flow path that ejects ink in accordance with image data during image recording. A dummy channel is a channel that never ejects ink, regardless of the image data. A dummy channel is not filled with ink because it does not need to eject ink. A dummy channel is usually filled with a gas such as air.

[0164] As shown in Figure 6 and its cross-sectional view of line VII-VII in Figure 7, each drive channel 11A, 11B and each dummy channel 12A, 12B opens to the lower surface 1Sa and the upper surface 1Sb of the pressure chamber substrate 1A, respectively, is straight across the lower surface 1Sa and the upper surface 1Sb, and is formed so that a cross section perpendicular to the thickness direction is rectangular, i.e., a quadrangular prism. Note that the cross-sectional view in Figure 7 shows a cross section of the channel row B, but the cross section of the channel row A is similar, and in the following explanation, the channel rows A and B will be explained with reference to Figure 7. The same applies to Figure 8.

[0165] A driving electrode 14 is formed on each of the four wall surfaces facing into each driving channel 11A, 11B and each dummy channel 12A, 12B, and further, a protective film 4 is formed on the entire surface of the driving electrode 14 facing into the driving channels 11A, 11B.

[0166] The protective film 4 is formed on the entire wall surface of the flow path substrate 3A facing the through holes 32A and 32B and on the entire wall surface of the adhesive layer 2 facing the through holes. The through holes 32A and 32B (first ink flow paths) of the flow path substrate 3A, the through holes of the adhesive layer 2, and the drive channels 11A and 11B (second ink flow paths) are connected to each other and form an ink flow path for the actuator Ac.

[0167] Connection electrodes (not shown) are formed on the upper surface 1Sb of the pressure chamber substrate 1A so as to correspond one-to-one to the drive channels 11A, 11B and the dummy channels 12A, 12B. One end of each connection electrode is electrically connected to the drive electrode 14 in the corresponding drive channel 11A, 11B or dummy channel 12A, 12B.

[0168] Actuator Ac is an independently driven actuator in which drive channels 11A, 11B and dummy channels 12A, 12B are alternately arranged in each channel row of pressure chamber substrate 1A, and shear deformation is caused in drive wall 13 by applying a drive signal of a predetermined voltage to drive electrode 14. This applies a pressure change for ejection to ink supplied into drive channels 11A, 11B, causing ink to be ejected as droplets from nozzles 21A, 21B of nozzle plate 20 bonded via adhesive layer 2 to the lower surface of actuator Ac, i.e., the lower surface 1Sa of pressure chamber substrate 1A.

[0169] 7 and 8, the adhesive layer 2 is a resin layer that bonds the nozzle plate 20 and the pressure chamber substrate 1A, and is arranged with its side facing the drive channel 11B, which is an ink flow path. The adhesive layer 2 has a first main surface 2Sa on the nozzle plate 20 side and a second main surface 2Sb on the pressure chamber substrate 1A side, and preferably at least the first main surface 2Sa, and more preferably both the first main surface 2Sa and the second main surface 2Sb, correspond to the adhesive main surface (X) that satisfies the requirement (2) of the present invention in relation to the interior 2c.

[0170] The adhesive layer 2 is preferably a layer formed using a curable resin as the resin, and more preferably a layer formed using the above-mentioned epoxy resin composition. The adhesive layer 2 can function as an adhesive layer by having a thickness in the range of, for example, 0.1 to 5 μm. The adhesive layer 2 has a structure corresponding to the resin layer shown in FIG. 2, for example.

[0171] Nozzles 21A and 21B are formed in the nozzle plate 20 at positions corresponding to the drive channels 11A and 11B of the pressure chamber substrate 1A. Since ink is not ejected from the dummy channels 12A and 12B, the nozzle plate 20 does not have nozzles at positions corresponding to the dummy channels 12A and 12B. Therefore, the openings below the dummy channels 12A and 12B are blocked by the nozzle plate 20.

[0172] The other ends of the connection electrodes corresponding to the drive channels 11A and dummy channels 12A in row A extend from within each channel 11A, 12A toward one edge of the upper surface 1Sb of the pressure chamber substrate 1A and terminate with a gap of approximately 200 μm between them. The other ends of the connection electrodes corresponding to the drive channels 11B and dummy channels 12B in row B extend from within each channel 11B, 12B toward row A and terminate with a gap of approximately 200 μm between them and the channel row A. Therefore, all of the connection electrodes extend in the same direction from each of the channels 11A, 11B, 12A, and 12B.

[0173] The driving electrodes 14 and the connection electrodes are made of a conductive material. Specific examples of the conductive material include conductive materials containing one or more metals such as platinum (Pt), gold (Au), copper (Cu), palladium (Pd), ruthenium (Ru), titanium (Ti), nickel (Ni), aluminum (Al), chromium (Cr), tungsten (W), and iridium (Ir). The conductive material may be a material containing one or more of these metals. The conductive material may be a mixture or alloy of metals. In this case, the conductive material may be a mixture or alloy of at least one of the above metals with another metal.

[0174] The flow path substrate 3A is a flat substrate having a lower surface 3Sa and an upper surface 3Sb, each of which has an area larger than the area of the upper surface 1Sb of the pressure chamber substrate 1A. The flow path substrate 3A has a bonding region 31 (shown by a dashed line in FIG. 6) on the lower surface 3Sa bonded to the upper surface 1Sb of the pressure chamber substrate 1A via an adhesive layer 2X. After bonding, at least one end of the flow path substrate 3A extends outside the bonding region 31 to which the pressure chamber substrate 1A is bonded, and protrudes significantly to the side in the direction in which the channel rows of the pressure chamber substrate 1A are arranged.

[0175] The bonding region 31 is the region covered by the pressure chamber substrate 1A to which the lower surface 3Sa of the flow path substrate 3A is bonded, and is defined by a line extending downward from the outer periphery of the upper surface 1Sb of the pressure chamber substrate 1A to the flow path substrate 3A.

[0176] The flow path substrate 3A may be made of any suitable material such as glass, ceramics, silicon, plastic, etc. Among these, glass is preferred because it has appropriate rigidity, is inexpensive, and is easy to process.

[0177] The flow path substrate 3A is bonded via an adhesive layer 2X so as to cover the openings of all channels located on the upper surface 1Sb of the pressure chamber substrate 1A in the bonding region 31. Within the bonding region 31 of the pressure chamber substrate 1A in the flow path substrate 3A, through holes 32A and 32B are individually opened only at positions corresponding to the drive channels 11A and 11B of the pressure chamber substrate 1A, for supplying ink from the upper surface 3Sb side of the flow path substrate 3A to each of the drive channels 11A and 11B.

[0178] Each of the through holes 32A, 32B is formed so that the opening on the pressure chamber substrate 1A side, i.e., the opening on the lower surface 3Sa of the flow path substrate 3A, is the same size and shape as the opening of each of the drive channels 11A, 11B on the flow path substrate 3A side, i.e., the opening on the upper surface 1Sb of the pressure chamber substrate 1A. In the actuator Ac, each of the through holes 32A, 32B in the flow path substrate 3A has a cross-sectional shape that widens from the lower surface 3Sa toward the upper surface 3Sb of the flow path substrate 3A.

[0179] On the other hand, in the flow path substrate 3A, such through holes are not formed in the portions corresponding to the dummy channels 12A and 12B of the pressure chamber substrate 1A, and therefore the openings above the dummy channels 12A and 12B (on the flow path substrate 3A side) are blocked by the flow path substrate 3A.

[0180] On the surface (lower surface) 3Sa of the flow channel substrate 3A, which is the bonding surface with the pressure chamber substrate 1A, wiring electrodes 33A and 33B are formed so as to correspond one-to-one to the respective connection electrodes arranged on the upper surface 1Sb of the pressure chamber substrate 1A. The wiring electrode 33A corresponds to each connection electrode of the channel row A, and the wiring electrode 33B corresponds to each connection electrode 15B of the channel row B. The wiring electrodes 33A and 33B are made of a conductive material. Examples of the conductive material include the same conductive materials as described above.

[0181] 6, one end of the wiring electrode 33A reaches the vicinity of the corresponding drive channel 11A and dummy channel 12A and overlaps the corresponding connection electrode in a plan view seen from above, while the other end extends toward the rear end of the flow path substrate 3A that protrudes laterally from the pressure chamber substrate 1A. Furthermore, one end of the wiring electrode 33B reaches the vicinity of the corresponding drive channel 11B and dummy channel 12B and overlaps the corresponding connection electrode in a plan view seen from above, while the other end passes between adjacent drive channels 11A in row A of channel array, straddles row A of channel array A, and extends toward the rear end of the flow path substrate 3A, similar to the wiring electrode 33A. Therefore, the wiring electrodes 33A and 33B are alternately arranged side by side from the inside of the bonding region 31 to the rear end on the underside 3Sa of the flow path substrate 3A that protrudes laterally from the pressure chamber substrate 1A.

[0182] A flexible substrate 8, which is an example of an external wiring member, is connected to the rear end of the flow path substrate 3A via, for example, an ACF (anisotropic conductive film) or the like, and electrically connects it to a drive circuit (not shown). As a result, a drive signal of a predetermined voltage from the drive circuit is applied to the drive electrodes 14 in each of the channels 11A, 11B, 12A, and 12B via the flexible substrate 8, the wiring electrodes 33A and 33B of the flow path substrate 3A, and the connection electrodes of the pressure chamber substrate 1A.

[0183] The wiring electrodes 33A, 33B extending from the bonding region 31 of the flow path substrate 3A to the rear end are covered with an insulating film 34 having a predetermined width outside the bonding region 31. The edge 34a of the insulating film 34 on the bonding region 31 side is formed linearly along the rear edge of the bonding region 31 so as to contact the rear edge, as shown in FIG. 6 . The width of the insulating film 34 preferably extends from the outside of the bonding region 31 to the connection position with the flexible substrate 8. Covering the bonding region 31 vicinity of the wiring electrodes 33A, 33B with the insulating film 34 in this manner prevents short-circuiting between the wiring electrodes 33A, 33B due to protrusion of conductive adhesive, contamination of the wiring electrodes 33A, 33B, and short-circuiting due to adhesion of ink, etc. Examples of materials for the insulating film 34 include TiO2, SiO2, and Al2O3.

[0184] The adhesive layer 2X that bonds the pressure chamber substrate 1A and the flow path substrate 3A has through holes that connect the drive channels 11A, 11B of the pressure chamber substrate 1A to the through holes 32A, 32B of the flow path substrate 3A. The through holes have openings on the pressure chamber substrate 1A side that are the same size and shape as the openings on the upper surface 1Sb of the drive channels 11A, 11B, and openings on the flow path substrate 3A side that are the same size and shape as the openings on the lower surface 3Sa of the through holes 32A, 32B.

[0185] In the actuator Ac, the adhesive layer 2X is a conductive adhesive layer made of a conductive adhesive. The conductive adhesive layer 2X allows electrical connection between the connection electrodes of the pressure chamber substrate 1A and the wiring electrodes 33A, 33B of the flow path substrate 3A, which are bonded thereto. The thickness of the adhesive layer 2X is preferably in the range of 0.1 to 5 μm, for example. The side surfaces of the adhesive layer 2X are covered with a protective film 4, and the adhesive layer 2X is not in contact with the drive channel 11B, which becomes the ink flow path. Therefore, the adhesive layer 2X does not have to be an adhesive layer having a main adhesive surface (X) according to the present invention. However, the adhesive layer 2X may be an adhesive layer having a main adhesive surface (X) according to the present invention.

[0186] The conductive adhesive may be, for example, an adhesive in which conductive particles are dispersed. Examples of the adhesive include a room temperature curing adhesive that cures at room temperature, a heat curing adhesive that cures by accelerating polymerization when heated, and an active energy ray curing adhesive that cures by irradiating active energy rays such as ultraviolet rays.

[0187] Among these, thermosetting adhesives are preferred. When a thermosetting adhesive is heated to a predetermined temperature for hardening after bonding, the viscosity of the adhesive temporarily decreases and the adhesive becomes more fluid, which is preferable in terms of the uniformity of the thickness of the resulting adhesive layer. As the thermosetting adhesive, an epoxy adhesive is preferably used, but there is no particular limitation.

[0188] The conductive particles include metal particles such as Au or Ni particles themselves, as well as synthetic resin particles whose surfaces are coated with a metal film such as Au or Ni by plating or the like, and either can be used in the present invention.

[0189] In the actuator Ac, a driving electrode is formed on the wall surface of the partition wall of the pressure chamber substrate facing each channel, and the adhesive constituting the adhesive layer as described above is a conductive adhesive to electrically connect the driving electrode to the wiring electrode of the flow path substrate. However, in the actuator according to the present invention, the driving electrode does not necessarily have to be formed on the wall surface of the partition wall facing each channel, as long as it is arranged to drive the partition wall. In other words, the adhesive layer may not necessarily be required to be conductive. In that case, the adhesive layer may be formed, for example, with an adhesive that does not contain conductive particles in the above-mentioned conductive adhesive.

[0190] 7, the protective film 4 of the actuator Ac is formed on the entire wall surface of the laminated substrate facing the ink flow path that connects the laminated substrate formed by bonding the flow path substrate 3A and the pressure chamber substrate 1A with the adhesive layer 2X. The wall surface facing the ink flow path of the laminated substrate is made up of the wall surfaces facing the ink flow path of the flow path substrate 3A, the adhesive layer 2X, and the pressure chamber substrate 1A.

[0191] The protective film 4 is a resin layer. The resin contained in the protective film 4 is preferably, for example, a polyimide resin or a polyparaxylylene resin, and more preferably a polyparaxylylene resin. Specifically, the polyparaxylylene resin is composed of polyparaxylylene or a derivative thereof. Examples of the derivative include compounds in which one or more hydrogen atoms bonded to the benzene ring of polyparaxylylene are substituted with a halogen atom such as fluorine, chlorine, or bromine, or with an alkyl group.

[0192] A thin film made of polyparaxylylene or its derivatives is called a parylene film, and can be formed by a vapor phase synthesis method using a dimer (solid) of paraxylylene or its derivatives as a vapor deposition source, known as a CVD (Chemical Vapor Deposition) method. The protective film 4 can be a resin layer having a main adhesive surface (X) according to the present invention. In this case, the base material is the drive electrode 14 or the pressure chamber substrate 1A, and the main adhesive surface (X) is configured to contact the drive electrode 14 or the pressure chamber substrate 1A.

[0193] When the protective film 4 is a resin layer having a main adhesive surface (X) according to the present invention, the resin composition used to form the protective film 4 preferably contains an amino-silane coupling agent. In a parylene film, since paraxylylene is composed only of carbon and hydrogen, a component containing oxygen, nitrogen, and silicon may be used as a derivative. However, in order to obtain the protective film 4 as a resin layer having a main adhesive surface (X) that is in contact with the substrate (requirement (1)) and satisfies requirement (2), it is preferable to use an amino-silane coupling agent that contains at least oxygen, nitrogen, and silicon.

[0194] The protective film 4 can function as a protective film by having a thickness in the range of, for example, 0.1 to 15 μm. The protective film 4 has a structure corresponding to the resin layer shown in FIG.

[0195] Fig. 8 is an enlarged view of the part surrounded by the dashed line in the cross-sectional view of Fig. 7. Specifically, it is an enlarged view of the periphery of the nozzle 21B in the part where the pressure chamber substrate 1A and the nozzle plate 20 are joined via the adhesive layer 2.

[0196] 8, as indicated by the arrows, ink is ejected from the drive channel 11B through the nozzle 21B toward a recording medium outside the ink ejection device 100. That is, in FIG. 8, the drive channel 11B and the nozzle 21B form an ink flow path, and members having the same configuration are arranged symmetrically on both sides of the ink flow path.

[0197] 8, the relationship between the pressure chamber substrate 1A, adhesive layer 2, and nozzle plate 20 is the same as the relationship between the base material B1, resin layer P, and base material B2 in Fig. 2. The adhesive layer 2 has a first main surface 2Sa that contacts the upper surface of the nozzle plate 20, and a second main surface 2Sb that contacts the lower surface of the pressure chamber substrate 1A. The adhesive layer 2 is made up of a first surface layer portion 2a that starts at the first main surface 2Sa and extends to a predetermined depth from the first main surface 2Sa, a second surface layer portion 2b that starts at the second main surface 2Sb and extends to a predetermined depth from the second main surface 2Sb, and an interior 2c that consists of the area other than the surface layer portions 2a and 2b.

[0198] As described above, the adhesive layer 2 preferably corresponds to an adhesive main surface (X) in which at least the first main surface 2Sa, and more preferably both the first main surface 2Sa and the second main surface 2Sb, satisfy the requirement (2) of the present invention in relation to the interior 2c.

[0199] In FIG. 8, the relationship between the pressure chamber substrate 1A with the drive electrodes 14 and the protective film 4 is the same as the relationship between the base material B and the resin layer P in FIG. 1. However, in FIG. 8, the pressure chamber substrate 1A has the drive electrodes 14, and the protective film 4 is formed on the ink flow path side surface of the drive electrodes 14. The protective film 4 has a first main surface 4Sa that contacts the ink flow path side surface of the drive electrodes 14, and a second main surface 4Sb that contacts the ink flow path. The protective film 4 is composed of a first surface layer portion 4a that starts from the first main surface 4Sa and extends to a predetermined depth from the first main surface 4Sa, a second surface layer portion 4b that starts from the second main surface 4Sb and extends to a predetermined depth from the second main surface 4Sb, and an interior portion 4c that is the area other than the surface layers 4a and 4b. As described above, the first main surface 4Sa of the protective film 4 preferably corresponds to the adhesive main surface (X) that satisfies requirement (2) of the present invention in relation to the interior portion 4c.

[0200] The shear mode actuator Ac and the ink jetting device of the present invention having the same have been described above using head chip 10A as an example. Below, an ink jetting device of the present invention having a bend mode actuator Ab will be described with reference to Figures 9 and 10.

[0201] Fig. 9 is a partial cross-sectional view of another example of an embodiment of an ink-discharge device of the present invention. Fig. 9 shows a cross-sectional view of a head chip 10B in the ink-discharge device. The head chip 10B has an actuator Ab and a nozzle plate 20 bonded to the actuator Ab via an adhesive layer 2A. The actuator Ab is a bend-mode actuator. Fig. 10 is an enlarged view of the portion of the ink-discharge device shown in Fig. 9 surrounded by a dashed line, which includes the pressure chamber substrate 1B, adhesive layer 2A, nozzle plate 20, and pressure chamber 11 that constitute the lower part of the actuator Ab.

[0202] Actuator Ab includes a flow path substrate 3B, which is formed by stacking, from top to bottom, a wiring substrate 3a, an adhesive layer 3d, a spacer substrate 3b, and a diaphragm 3v, an adhesive layer 2B located below the flow path substrate 3B, and a pressure chamber substrate 1B bonded to the flow path substrate 3B via the adhesive layer 2B. The spacer substrate 3b has a hollow portion, and inside the hollow portion is a piezoelectric element, which is formed by stacking, from top to bottom, an upper electrode (driving electrode) 3e, a piezoelectric element 3P, and a lower electrode (driving electrode) 3f. The portion of the hollow portion other than the piezoelectric element is space 3S.

[0203] The upper electrode 3e of the piezoelectric element is connected to an external power supply by multiple wiring conductors E that are electrically connected from the spacer substrate 3b to the wiring substrate 3a. The lower electrode 3f is connected to the external power supply via a separate path. The piezoelectric element 3P is driven by applying a voltage via the upper electrode 3e and the lower electrode 3f. This causes the diaphragm 3v to bend downward.

[0204] The diaphragm 3v is bonded to a pressure chamber substrate 1B, which is disposed below the piezoelectric element, via an adhesive layer 2B. A nozzle plate 20 having nozzles 21 is bonded to the underside of the pressure chamber substrate 1B via an adhesive layer 2A. The nozzle plate 20 can be made of the same material as the nozzle plate bonded to the actuator Ac.

[0205] The pressure chamber substrate 1B has pressure chambers (drive channels) 11 that contain ink, and nozzles 21 communicate with the pressure chambers 11. When the piezoelectric element is driven, the volume of the pressure chambers 11 decreases due to the curved vibration plate 3v, causing the ink contained in the pressure chambers 11 to be ejected from the nozzles 21.

[0206] The flow path substrate 3B and the adhesive layer 2B have through holes 32 that serve as ink flow paths that communicate with the pressure chambers 11 of the pressure chamber substrate 1B. Ink is supplied to the pressure chambers 11 from above the actuators Ab through the through holes 32. The ink flow paths in the head chip 10B are made up of the through holes 32, the pressure chambers 11, and the nozzles 21.

[0207] The constituent materials of the wiring substrate 3a, spacer substrate 3b, and pressure chamber substrate 1B in the flow path substrate 3B of actuator Ab can be, for example, SUS, nickel, 42 alloy, silicon (Si), etc. The conductive materials that constitute the piezoelectric body 3P, the upper electrode (driving electrode) 3e, the lower electrode (driving electrode) 3f, the wiring conductors, etc. can be the same materials as those described for actuator Ac.

[0208] As the diaphragm 3v, any general diaphragm used in a bent mode type actuator can be used without any particular restrictions.

[0209] Adhesive layer 3d, adhesive layer 2B, and adhesive layer 2A are all adhesive layers formed between base materials, and have a configuration in which their sides come into contact with ink flowing through the ink flow paths. Adhesive layer 3d, adhesive layer 2B, and adhesive layer 2A can all have the same configuration as adhesive layer 2 described in connection with head chip 10A. In particular, adhesive layer 2A, which bonds pressure chamber substrate 1B and nozzle plate 20, preferably has the same configuration as adhesive layer 2.

[0210] The enlarged cross-sectional view shown in Fig. 10 corresponds to Fig. 2. In Fig. 10, the relationship between the pressure chamber substrate 1B, the adhesive layer 2A, and the nozzle plate 20 is the same as the relationship between the base material B1, the resin layer P, and the base material B2 in Fig. 2. The adhesive layer 2A has a first main surface 2Sa that contacts the upper surface of the nozzle plate 20, and a second main surface 2Sb that contacts the lower surface of the pressure chamber substrate 1B. The adhesive layer 2A is made up of a first surface layer portion 2a that starts at the first main surface 2Sa and extends to a predetermined depth from the first main surface 2Sa, a second surface layer portion 2b that starts at the second main surface 2Sb and extends to a predetermined depth from the second main surface 2Sb, and an interior 2c that is made up of the area other than the surface layer portions 2a and 2b.

[0211] As described above, the adhesive layer 2A preferably corresponds to an adhesive main surface (X) in which at least the first main surface 2Sa, and more preferably both the first main surface 2Sa and the second main surface 2Sb, satisfy the requirement (2) of the present invention in relation to the interior 2c.

[0212] [ink] The ink used in the ink-jet device of the present invention is not particularly limited to inks for ink jet recording. The ink-jet device of the present invention is one in which the interface between the resin layer formed on or between the substrates and the substrate has excellent ink resistance, and can exhibit its effects regardless of the type of ink.

[0213] Specifically, the effect is significant when using an aqueous ink containing components such as water, colorant, dispersant, surfactant, preservative, humectant, glycol-based solvent, etc. The effect is also significant when using actinic radiation-curable ink, for example, ink containing at least an actinic radiation-polymerizable compound, a polymerization initiator, and a colorant. Examples of actinic radiation-polymerizable compounds include photocationic polymerizable compounds and photoradical polymerizable compounds, and examples of polymerization initiators include photocationic polymerization initiators and photoradical polymerization initiators, respectively.

[0214] In the present invention, in particular, a compound having at least one group selected from a carboxylic acid group, a sulfonic acid group, and a phosphonic acid group, SO4 2- , PO4 3- , B(C6F5)4 - , SbF6 - , PF6 - , BF4 - , CF3SO3 - , and C4F9SO3 - The effect is remarkable when using an ink containing at least one anion selected from the following. These compounds and anions include, for example, those derived from coloring materials. Also, B(C6F5)4 - , SbF6 - , PF6 - , BF4 - , CF3SO3 - , and C4F9SO3 - The above includes those derived from cationic photopolymerization initiators.

[0215] The ink ejection device of the present invention thus uses a compound having at least one group selected from a carboxylic acid group, a sulfonic acid group, and a phosphonic acid group, SO4 2- , PO4 3- , B(C6F5)4- , SbF6 - , PF6 - , BF4 - , CF3SO3 - , and C4F9SO3 - Even when an ink containing at least one anion selected from the group consisting of the above is used, the interface between the resin layer formed on or between the substrates and the substrate has excellent ink resistance. [Example]

[0216] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0217] [Experimental Example] A resin layer was formed between two SUS substrates using the following method, and the atomic composition of the adhesive surface and the interior was measured using XPS.

[0218] (Preparation of Resin Composition) Specifically, resin compositions were prepared for Examples 1 to 3 and Comparative Example 1, the compositions of which are shown in Table I. Both jER828 (bisphenol A type epoxy compound, epoxy equivalent weight 184 to 194, weight average molecular weight 370) and jER152 (phenol novolac type epoxy compound, epoxy equivalent weight 176 to 178, weight average molecular weight 370) are epoxy compounds manufactured by Mitsubishi Chemical Corporation. Furthermore, in 2-ethyl-4-methylimidazole, H + The pKa of the adduct at 25°C is 8.3.

[0219] [Table 1]

[0220] (Preparation of laminated samples) The two SUS substrates used were a SUS304 (thickness: 0.05 mm) nozzle plate substrate (SUS substrate with 1000 nozzles) and a SUS304 flow path plate substrate (SUS substrate with ink flow paths). First, the resin composition for Example 1 obtained above was applied to the nozzle plate substrate, and the flow path plate substrate was laminated on top of it. A certain weight was applied and the mixture was heat-cured at 100°C for 1 hour to form a resin layer (thickness: 1.5 μm) between the two SUS substrates, which was used as a laminated sample. Using each resin composition other than the resin composition for Example 1, a resin layer was formed between two SUS substrates in the same manner as above to prepare samples.

[0221] (1) XPS depth profile measurement For each laminated sample, the blade of a cutter knife was inserted between one of the SUS substrates and the resin layer to create a gripping area for peeling, and the resin layer was peeled off using tweezers. XPS depth profile measurements were performed on the main surface of the peeled resin layer under the following conditions.

[0222] <Measurement conditions> Analytical equipment: ULVAC-PHI QUANTERA SXM ·X-ray source: Monochromatic Al-Kα 15kV 25W Sputter ions: Ar (1 keV) Depth profile: Measurements are repeated at predetermined thickness intervals in terms of SiO2 equivalent sputtering thickness to obtain a depth profile. This thickness interval was 10.8 nm for Example 1 and Comparative Example 1, and 11.4 nm for Examples 2 and 3 (data is obtained every 10.8 nm or 11.4 nm in the depth direction). Quantitation: The background was determined by the Shirley method, and quantitation was performed using the relative response factor method from the obtained peak area. Data was processed using MultiPak manufactured by ULVAC-PHI.

[0223] The atomic concentration of each element inside the resin layer was calculated as the average of the measured values at six locations for each sputtering thickness from a depth of 10.8 nm to 64.8 nm or from 11.4 nm to 68.4 nm from the main surface. The measurements were performed at two locations randomly selected in the surface direction, and the atomic concentration of each element on the main surface and inside was calculated as the average of the measured values.

[0224] The XPS measurement results confirmed that all of the resin layers described above contained carbon, nitrogen, oxygen, and silicon. Table II shows the atomic concentration (atm%) of each element measured above for all elements, i.e., carbon, nitrogen, oxygen, silicon, chromium, and iron. Chromium and iron are components derived from the substrate. The detection limit in the above measurement was 0.1 atm%. In Table II, "ND" indicates that the element was not detected. The depth profiles of nitrogen, oxygen, and silicon from the XPS depth profile measurement results for Examples 1 to 3 are shown in Figures 11A to 11C, respectively.

[0225] Furthermore, for nitrogen, oxygen, and silicon, the ratio of the atomic concentration on the main surface to the interior (the ratio of the atomic concentration on the main surface to the atomic concentration in the interior) is also shown in Table II.

[0226] [Table 2]

[0227] (2) Analysis of the bonding state of nitrogen atoms on the main surface of the resin layer by XPS The principal surfaces of the resin layers peeled from the laminate samples of Examples 2 and 3 in the same manner as above were subjected to nitrogen atom bonding state analysis by XPS under the following conditions.

[0228] <Measurement conditions> Analytical equipment: ULVAC-PHI QUANTERA SXM ·X-ray source: Monochromatic Al-Kα 15kV 25W Pass energy: 55 eV Data processing: Using MultiPak manufactured by ULVAC-PHI Elemental composition analysis: Background processing is performed using the Shirley method, and the elemental composition is quantified using the relative sensitivity coefficients from the obtained peak areas.

[0229] 12A, 12B, and 12C show spectral charts in which the peaks related to nitrogen atoms (shown by solid lines in the figures) are separated into peaks for each state for Examples 1 to 3. In all of FIGS. 12A, 12B, and 12C, the peaks related to nitrogen atoms are -NH2 and -NH3. + This shows that the two peaks were separated.

[0230] Table III shows the results of -NH2 and -NH3 for Examples 1 to 3. + The bond energy (eV) of the maximum peak position of -NH2 and -NH3 + The ratio of nitrogen atoms derived from -NH2 and -NH3 to the total amount of nitrogen atoms was calculated from the peak areas of + The ratio of nitrogen atoms derived from the hydroxyl group is shown in Table III. The literature values shown above are also shown in Table III.

[0231] [Table 3]

[0232] [evaluation] Two laminate samples were prepared for each of the examples and comparative examples in the same manner as above, and the ink resistance was evaluated using two types of test liquids according to the following method. The results are shown in Table IV.

[0233] (Preparation of actual ink for evaluation: Disperse dye ink (test liquid 1)) <Preparation of dispersion liquid> Disperse dye: CIDisperse Yellow 160 24.0% by mass Diethylene glycol 30.6% by mass Styrene-maleic anhydride copolymer (dispersant) 12.0% by mass Water 33.4% by mass

[0234] The mixture was dispersed using ceramic beads with a diameter of 0.5 mm in a sand grinder manufactured by Imex Co., Ltd. at a rotation speed of 2500 rpm for 5 hours. This dispersion was diluted with water / diethylene glycol in a ratio of 1:4 so that the dye concentration became 5%, to prepare Dispersion 1.

[0235] <Preparation of Actual Ink> Each composition was added to the above dispersion liquid 1 and stirred to prepare a working ink for evaluation (disperse dye ink).

[0236] Dispersion 1 20.0% by mass Ethylene glycol 10.0% by mass Glycerin 8.0% by mass Emulgen 911 (Kao Corporation) 0.05% by mass

[0237] Ion-exchanged water was added to the above components to make up 100% by mass, to obtain a disperse dye ink (Test Solution 1). The liquid properties of the prepared ink were investigated and it was confirmed to be alkaline (pH 8.0 or higher).

[0238] (Preparation of actual ink for evaluation: reactive dye ink (test liquid 2)) CI Reactive Yellow 220 copies Sodium dihydrogen phosphate 0.034 parts Disodium hydrogen phosphate 0.166 parts Wednesday 79.8 parts

[0239] The dye solution having the above composition was adjusted to pH 8.5 with a 10% aqueous solution of sodium carbonate to prepare a reactive dye ink (test solution 2).

[0240] (Evaluation of laminated samples) One of each of the laminated samples obtained above was immersed in Test Liquid 1 and Test Liquid 2, which had been kept at 60° C., and left for 50 days.

[0241] After 50 days of immersion, each laminated sample was washed with pure water and dried. The presence or absence of peeling at the interface between the nozzle plate substrate and the resin layer inside the 1,000 nozzles of each laminated sample was checked, and the adhesion resistance between the nozzle plate substrate and the resin layer for Test Liquid 1 and Test Liquid 2 was evaluated according to the following criteria.

[0242] <Evaluation criteria> ⊚: No peeling was observed in any of the 1000 nozzles. ◯: Very weak peeling is observed in one or more but less than 5% of the nozzles, but this does not pose a problem in practical use. △: Weak separation was observed in 5% or more and less than 10% of the nozzles, and the quality was acceptable for practical use. ×: There are nozzles where clear peeling is observed, and the quality is problematic for practical use.

[0243] [Table 4] [Industrial Applicability]

[0244] According to the present invention, an ink ejection device having long-term reliability can be provided, since the interface between the substrate and the resin layer disposed between or on the substrate has excellent ink resistance. [Explanation of symbols]

[0245] 100: Ink ejection device 10A, 10B: Head chip 1A, 1B: Pressure chamber substrate 11, 11A, 11B: driving channel (second ink flow path) 12A, 12B: Dummy channels 13: Driving wall 14: Drive electrode 2, 2A, 2B: Adhesive layer 3A, 3B: Channel board 31:Joint area 32, 32A, 32B: through holes (first ink flow paths) 33A, 33B: Wiring electrode 34: insulating film 3a: Wiring board 3b: Spacer substrate 3d:adhesive layer 3v: diaphragm 3e: Upper electrode (drive electrode) 3f: Lower electrode (drive electrode) 3P: Piezoelectric 3S: Space E: Wiring conductor 4:Protective film 5: Manifold 6: Housing 7: Cover material 8: Flexible board 20: Nozzle plate 21, 21A, 21B: Nozzle

Claims

1. An ink ejection device comprising: a substrate; a resin layer laminated so that at least one main surface thereof is in contact with the substrate; and an ink flow path disposed so that ink flows while contacting a portion of the resin layer, The resin layer contains carbon, oxygen, nitrogen, and silicon, and An ink ejection device characterized in that at least one of the main surfaces satisfies the following requirements (1) and (2). (1) The main surface is in contact with the substrate. (2) When the atomic concentrations (atm %) of nitrogen, oxygen, and silicon on the main surface of the resin layer measured by X-ray photoelectron spectroscopy are represented by main surface N, main surface O, and main surface Si, respectively, and the atomic concentrations (atm %) of nitrogen, oxygen, and silicon inside the resin layer are represented by internal N, internal O, and internal Si, respectively, main surface O > internal O and main surface N > 3.62, and the ratio of main surface Si to internal Si, represented by main surface Si / internal Si, is 10.9 or more.

2. 2. The ink ejection device according to claim 1, wherein the main surface that satisfies the requirements (1) and (2) further satisfies the requirement (3). (3) The ratio of the main surface N to the internal N, expressed as main surface N / internal N, is 2.2 or more.

3. The spectrum obtained by analyzing the bonding state of nitrogen atoms by X-ray photoelectron spectroscopy for a main surface that satisfies the requirements (1) and (2) above is -NH ２ or -NH ３ ＋ 3. The ink ejection device according to claim 1, wherein the ink ejection device has a peak of:

4. The resin layer is made of an epoxy compound, H ＋ 4. The ink ejection device according to claim 1, wherein the cured product is a resin composition containing a curing agent whose adduct has a pKa of 3 or more and an amino-based silane coupling agent.

5. 5. The ink ejection device according to claim 4, wherein the curing agent is a nitrogen-containing catalyst type curing agent.

6. 6. The ink ejection device according to claim 4, wherein the content of the curing agent relative to the total amount of the resin composition is in the range of 8.93 to 9.07% by mass.

7. 7. The ink ejection device according to claim 4, wherein the amino-silane coupling agent has a molecular weight per nitrogen atom of 179.29 or less.

8. 8. The ink ejection device according to claim 4, wherein the amino-silane coupling agent has three alkoxy groups bonded to silicon atoms.

9. 9. The ink ejection device according to claim 1, wherein the material constituting the substrate with which the main surface satisfying the requirements (1) and (2) is in contact is stainless steel (SUS).

10. 10. The ink ejection device according to claim 1, wherein the ink contains an anion of PO 4 3-.

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