Liquid jetting structure body, liquid jetting head, liquid jetting device, manufacturing method of liquid jetting structure body, and laminate

Abstract

To provide a liquid jetting structure body, a liquid jetting head, and a liquid jetting device, in which a jetting surface has excellent wipe resistance.SOLUTION: A liquid jetting structure body and its applications include a nozzle substrate on which a nozzle jetting a liquid is formed, in which a liquid-repellent layer is provided on a jetting surface of the nozzle substrate, and the liquid-repellent layer contains a compound having a hydrocarbon group having 8 or more carbon atoms.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection structure, a liquid ejection head, a liquid ejection device, a method for manufacturing a liquid ejection structure, and a laminate. [Background technology]

[0002] Generally, a liquid ejection head, such as an inkjet head, mounted on an inkjet recording apparatus has nozzles for ejecting liquid. The liquid is supplied from a liquid supply chamber to a liquid flow path and ejected from a nozzle hole formed in a nozzle connected to the liquid flow path.

[0003] For example, Patent Document 1 describes a nozzle plate that includes a silicon substrate on which a nozzle is formed, a first organic film that does not contain fluorine atoms formed on the silicon substrate, an inorganic oxide film formed on the first organic film, and a second organic film formed on the inorganic oxide film and made from a linear fluorine silane coupling agent. Patent Document 2 describes a liquid-repellent treatment method for imparting liquid repellency to the surface of a substrate having holes, the liquid-repellent treatment method comprising an organic film formation step of forming an organic film on the surface of the substrate and the inner wall surfaces of the holes, a protective member formation step of forming a protective member on the organic film on the surface of the substrate, an organic film removal step of removing the organic film on the inner wall surfaces of the holes of the substrate, a protective member removal step of removing the protective member on the organic film on the surface of the substrate, and a fluorination treatment step of fluorinating the organic film on the surface of the substrate. Patent Document 3 describes a liquid ejection structure that includes a nozzle substrate on which nozzles for ejecting liquid are formed, and a flow path substrate on which liquid flow paths communicating with the nozzles are formed, wherein a first layer, a second layer, and a liquid-repellent layer are formed in this order on the ejection surface of the nozzle substrate, and the first layer and the second layer are formed in this order on the inner wall of the liquid flow path, wherein the first layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide, and the second layer is a layer containing at least one selected from the group consisting of SiO2, SiC, SiN, SiCN, and SiON, and wherein the liquid-repellent layer contains a compound having a perfluoropolyether structure. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-166747 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-214654 [Patent Document 3] International Publication No. 2021 / 199731 Summary of the Invention [Problem to be solved by the invention]

[0005] When the liquid dries after being ejected, components contained in the liquid adhere to the ejection surface of the liquid ejection head as foreign matter. If foreign matter adheres to the nozzle surface, ejection defects are likely to occur. Therefore, in liquid ejection devices, foreign matter can be removed by periodically wiping the ejection surface of the liquid ejection head. However, wiping can sometimes reduce the durability of the ejection surface of the liquid ejection head, so durability against wiping (hereinafter also referred to as "wipe resistance") is required.

[0006] The present disclosure has been made in consideration of these circumstances, and the problem that one embodiment of the present invention aims to solve is to provide a liquid ejection structure, a liquid ejection head, and a liquid ejection device whose ejection surface has excellent wipe resistance. Another problem to be solved by another embodiment of the present disclosure is to provide a laminate useful for a liquid ejection structure having an ejection surface with excellent wipe resistance. [Means for solving the problem]

[0007] The present disclosure includes the following aspects. <1> a nozzle substrate on which nozzles for discharging liquid are formed; A liquid-repellent layer is provided on the ejection surface of the nozzle substrate, A liquid ejection structure, wherein the liquid-repellent layer contains a compound having a hydrocarbon group having 8 or more carbon atoms. <2> The compound having a hydrocarbon group having 8 or more carbon atoms has a partial structure represented by the following formula (1): <1> The liquid ejection structure according to claim 1. LYM-* …(1) In formula (1), L is a hydrocarbon group having 8 or more carbon atoms, Y is a single bond or a divalent linking group, M is a metalloid or a metal; * indicates the bonding position with other structures. <3> The hydrocarbon group having 8 or more carbon atoms is a linear alkyl group having 8 or more carbon atoms. <1> or <2> The liquid ejection structure according to claim 1. <4> In formula (1), Y is a single bond. <2> The liquid ejection structure according to claim 1. <5> An intermediate layer and a liquid-repellent layer are provided in this order on the ejection surface of the nozzle substrate. <1> ~ <4> 10. The liquid ejection structure according to claim 9, wherein the liquid ejection structure is a liquid ejection structure having a diameter of 100 mm or more. <6> The intermediate layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, hafnium oxide, SiO2, SiC, SiN, SiCN, and SiON. <1> ~ <5> 10. The liquid ejection structure according to claim 9, wherein the liquid ejection structure is a liquid ejection structure having a diameter of 100 mm or more. <7> The middle layer consists of two layers: A first intermediate layer, a second intermediate layer, and a liquid-repellent layer are provided on the ejection surface in this order. <5> The liquid ejection structure according to claim 1. <8> the first intermediate layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide; The second intermediate layer is a layer containing at least one selected from the group consisting of SiO2, SiC, SiN, SiCN, and SiON. <7> The liquid ejection structure according to claim 1. <9> <1> ~ <8> 1. A liquid ejection head comprising: a liquid ejection structure according to any one of the above items; and a flow path substrate on which liquid flow paths communicating with the nozzles are formed. <10> Further comprising a piezoelectric element. <9> The liquid ejection head according to claim 1. <11> <9> a conveying means for conveying a substrate; and a drying means for drying the liquid discharged onto the substrate. <12> A method for manufacturing a liquid ejection structure, comprising forming a liquid-repellent layer by a vapor deposition method on an ejection surface of a nozzle substrate on which nozzles for ejecting liquid are formed, using a liquid-repellent layer-forming composition containing a compound having a hydrocarbon group having 8 or more carbon atoms. <13> A substrate; a liquid-repellent layer disposed on the substrate; The liquid-repellent layer is a laminate containing a compound having a hydrocarbon group having 8 or more carbon atoms. [Effects of the Invention]

[0008] According to an embodiment of the present disclosure, there are provided a liquid ejection structure, a liquid ejection head, a liquid ejection device, and a method for manufacturing a liquid ejection structure, each of which has an ejection surface with excellent wipe resistance. According to another embodiment of the present disclosure, a laminate useful for a liquid ejection structure having an ejection surface with excellent wipe resistance is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of a liquid ejection head according to the present disclosure. [Figure 2] FIG. 2 is an enlarged view of the dashed frame A in FIG. [Figure 3] FIG. 3 is a diagram showing a modified example of the intermediate layer. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a modified example of the liquid ejection head of the present disclosure. [Figure 5] FIG. 5 is a schematic cross-sectional view showing another embodiment of the liquid ejection head of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] The liquid ejection structure, liquid ejection head, liquid ejection device, method for manufacturing a liquid ejection structure, and laminate according to the present disclosure will be described in detail below.

[0011] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced by the upper or lower limit value of another numerical range described in stages, or may be replaced by a value shown in an example. In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In this disclosure, combinations of preferred aspects are more preferred aspects. The elements in the drawings shown in this disclosure are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure.

[0012] In the present disclosure, the term "liquid-repellent layer" refers to a layer having a contact angle with water of 60° or greater. The contact angle with water is a value measured at 25°C using a contact angle meter, for example, a fully automatic contact angle meter (product name "DM-701", manufactured by Kyowa Interface Science Co., Ltd.). In the present disclosure, the term "ejection surface" refers to the surface of the nozzle substrate on the side from which liquid is ejected in the liquid ejection structure. In the present disclosure, the "inner wall of a liquid flow path" refers to the surface of a flow path substrate on which a liquid flow path is formed, and the "inner wall of a nozzle" refers to the surface of a nozzle substrate on which a nozzle is formed.

[0013] [Liquid discharge structure] The liquid ejection structure of the present disclosure includes a nozzle substrate on which nozzles for ejecting liquid are formed, and has a liquid-repellent layer on the ejection surface of the nozzle substrate, the liquid-repellent layer containing a compound having a hydrocarbon group with 8 or more carbon atoms.

[0014] The liquid-repellent layer is located on the outermost surface of the nozzle substrate. That is, the liquid-repellent layer is the outermost layer of multiple layers provided on the nozzle substrate. The liquid ejection structure of the present disclosure has a liquid-repellent layer on the outermost surface of the nozzle substrate, and therefore has excellent anti-fouling properties for the ejection surface.

[0015] In particular, the liquid ejection structure of the present disclosure has excellent wipe resistance on the ejection surface because the liquid-repellent layer contains a compound having a hydrocarbon group with 8 or more carbon atoms. This is thought to be because the durability of the liquid-repellent layer is improved by aggregation of the hydrocarbon group with 8 or more carbon atoms.

[0016] In contrast, the liquid-repellent layers described in Patent Documents 1 to 3 are all fluorine-based liquid-repellent layers, and there is no description that focuses on liquid-repellent layers containing compounds with hydrocarbon groups having 8 or more carbon atoms.

[0017] Hereinafter, an embodiment of a liquid ejection structure according to the present disclosure will be described with reference to the drawings showing an embodiment of a liquid ejection head according to the present disclosure.

[0018] FIG. 1 is a cross-sectional view showing an embodiment of a liquid ejection head according to the present disclosure.

[0019] 1, the liquid ejection head 100 comprises a liquid ejection structure having a nozzle substrate 10 in which nozzles 30 for ejecting liquid are formed, and a flow path substrate 20 in which liquid flow paths 40 communicating with the nozzles 30 are formed. The nozzle substrate 10 and the flow path substrate 20 are preferably joined by adhesion or the like. In the present disclosure, the liquid ejection structure refers to a structure including a nozzle substrate 10 on which nozzles 30 for ejecting liquid are formed, and a liquid-repellent layer, which will be described later. In other words, the liquid ejection structure is a part of a liquid ejection head.

[0020] There are no particular limitations on the type of liquid supplied to the liquid ejection head 100. When the liquid ejection head 100 is incorporated into a liquid ejection device described below, it is possible to eject fine droplets of liquid from the nozzles 30. It is preferable to use ink as the liquid, and an image can be recorded by ejecting fine ink droplets onto a substrate.

[0021] The ink for recording an image is a liquid containing, for example, a colorant, a solvent, and a surfactant. Furthermore, a pretreatment liquid may be ejected onto the substrate before the ink is ejected onto the substrate, or a posttreatment liquid may be ejected after the ink is ejected. Therefore, examples of the liquid supplied to the liquid ejection head 100 include a pretreatment liquid and a posttreatment liquid in addition to the ink. The pretreatment liquid and the posttreatment liquid are typically colorless liquids that do not contain a colorant.

[0022] Furthermore, the liquid supplied to the liquid ejection head 100 may be an acidic liquid or an alkaline liquid. The liquid ejection head 100 is suitable for alkaline liquids because the ejection surface and the inside of the flow path have excellent alkali resistance. The liquid ejection head 100 is particularly suitable for liquids with a pH of 8 to 11. The pH is a value measured at 25°C using a pH meter, for example, a value measured using a product name "Handy pH Meter" manufactured by Sato Keiryoki Seisakusho.

[0023] <Nozzle board> The nozzle substrate 10 is, for example, a substrate made of silicon, and may be a single crystal silicon substrate or a polycrystalline silicon substrate. The nozzle substrate 10 has nozzles 30 formed thereon that eject liquid.

[0024] The nozzles 30 are holes that penetrate the nozzle substrate 10 and are formed by, for example, dry etching. It is preferable that a plurality of nozzles 30 are formed on the nozzle substrate 10. There are no particular limitations on the shape of the nozzles 30, but from the perspective of controlling the liquid ejection direction, it is preferable that the nozzles 30 have a tapered shape in which the diameter decreases in the direction in which the liquid is ejected. The hole diameter of the nozzle 30 on the side from which the liquid is ejected, i.e., the hole diameter of the nozzle opening 31, can be adjusted as appropriate. When the liquid ejection head 100 is used in an inkjet head, the hole diameter of the nozzle opening 31 is, for example, 10 μm to 30 μm.

[0025] The thickness of the nozzle substrate 10 corresponds to the length of the nozzle 30 and is preferably 10 μm to 100 μm, and more preferably 20 μm to 60 μm.

[0026] FIG. 2 is an enlarged view of the dashed frame A in FIG.

[0027] As shown in FIG. 2, an intermediate layer 51 and a liquid-repellent layer 52 are provided in this order on the ejection surface 101 of the nozzle substrate 10. If the intermediate layer 51 is included between the nozzle substrate and the liquid-repellent layer, corrosion of the nozzle substrate 10 due to deterioration of the liquid-repellent layer 52 can be suppressed.

[0028] The intermediate layer 51 is preferably a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, hafnium oxide, SiO 2 , SiC, SiN, SiCN, and SiON.

[0029] At least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide (preferably tantalum oxide, zirconium oxide, or hafnium oxide) has excellent alkali resistance. Therefore, when alkaline liquid penetrates into the liquid-repellent layer 52 provided on the ejection surface of the nozzle substrate after long-term use, the presence of the intermediate layer 51 makes it possible to maintain the alkali resistance of the ejection surface. A layer containing at least one selected from the group consisting of SiO2, SiC, SiN, SiCN, and SiON (preferably an SiO2 layer) has high adhesion to the liquid-repellent layer 52. Therefore, alkaline liquids do not easily penetrate into the liquid-repellent layer 52, and the ejection surface has excellent alkali resistance.

[0030] The thickness of the intermediate layer 51 is preferably 0.3 nm to 100 nm, and more preferably 0.5 nm to 50 nm. If the thickness of the intermediate layer 51 is 100 nm or less, the stress in the film does not become too large, and cracks are less likely to occur. When the thickness of the intermediate layer 51 is 0.3 nm or more, the film tends to be uniform, and the adhesion to the liquid-repellent film improves.

[0031] From the viewpoint of further enhancing the wipe resistance and alkali resistance of the ejection surface, it is preferable that the intermediate layer 51 consists of two layers, as shown in FIG. 3, and that a first intermediate layer 51A, a second intermediate layer 51B, and a liquid-repellent layer 52 are provided in this order on the ejection surface 101 of the nozzle substrate 10.

[0032] The first intermediate layer 51A is preferably a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide, and more preferably a layer of tantalum oxide, zirconium oxide, or hafnium oxide.

[0033] At least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide (preferably tantalum oxide, zirconium oxide, or hafnium oxide) has excellent alkali resistance. Therefore, when alkaline liquid penetrates into the liquid-repellent layer 52 and second intermediate layer 51B provided on the ejection surface of the nozzle substrate after long-term use, the presence of first intermediate layer 51A makes it possible to maintain the alkali resistance of the ejection surface.

[0034] The thickness of the first intermediate layer 51A is preferably 3 nm to 70 nm, more preferably 10 nm to 50 nm, and even more preferably 20 nm to 50 nm. When the thickness of the first intermediate layer 51A is 3 nm or more, alkaline liquids are less likely to penetrate, and the ejection surface has better wiping resistance and alkali resistance. On the other hand, when the thickness of the first intermediate layer 51A is 70 nm or less, defects are less likely to occur within the layer, and the ejection surface has better wiping resistance and alkali resistance. From the viewpoint of productivity, the thickness of the first intermediate layer 51A is preferably 50 nm or less.

[0035] The second intermediate layer 51B is preferably a layer containing at least one selected from the group consisting of SiO2, SiC, SiN, SiCN, and SiON, and is more preferably an SiO2 layer.

[0036] A layer containing at least one selected from the group consisting of SiO2, SiC, SiN, SiCN, and SiON (preferably an SiO2 layer) has high adhesion to the liquid-repellent layer 52. Therefore, alkaline liquids do not easily penetrate into the liquid-repellent layer 52 and the second intermediate layer 51B, and the ejection surface has excellent wipe resistance and alkali resistance.

[0037] The thickness of the second intermediate layer 51B is preferably 0.3 nm to 120 nm, more preferably 0.3 nm to 3 nm or 10 nm to 100 nm, even more preferably 0.3 nm to 3 nm, and particularly preferably 0.5 nm to 2 nm. In particular, when the thickness of the second intermediate layer 51B is 0.3 nm to 3 nm or 10 nm to 100 nm, the adhesion between the second intermediate layer 51B and the liquid-repellent layer 52 is improved, and the wiping resistance and alkali resistance of the ejection surface are improved.

[0038] The liquid-repellent layer 52 is preferably a layer having a contact angle with water of 60° or more. The contact angle with water of the liquid-repellent layer 52 is more preferably 70° or more, and even more preferably 80° or more. Since the liquid-repellent layer 52 is provided on the outermost surface of the nozzle substrate 10, the ejection surface has excellent wipe resistance.

[0039] The liquid-repellent layer 52 contains a compound having a hydrocarbon group with eight or more carbon atoms (hereinafter also referred to as a "specific compound"). When the hydrocarbon group contained in the specific compound has 8 or more carbon atoms, the hydrocarbon groups aggregate together, improving the durability of the liquid-repellent layer.

[0040] From the viewpoint of improving the durability of the liquid-repellent layer by further agglomerating the hydrocarbon groups, the number of carbon atoms in the hydrocarbon group contained in the specific compound is preferably 10 or more, and more preferably 18 or more. There are no particular restrictions on the upper limit of the carbon number, but from the viewpoint of ease of film formation, it is preferably 40 or less, more preferably 30 or less, and even more preferably 22 or less.

[0041] The hydrocarbon group contained in the specific compound may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The hydrocarbon group may be a monovalent hydrocarbon group or a divalent hydrocarbon group. Among these, the hydrocarbon group is preferably an aliphatic hydrocarbon group, more preferably an alkyl group. The alkyl group may be any of a linear alkyl group, a branched alkyl group, and a cyclic alkyl group.

[0042] From the viewpoint of improving the durability of the liquid-repellent layer by further aggregating the hydrocarbon groups together, the hydrocarbon group having 8 or more carbon atoms is preferably a linear alkyl group having 8 or more carbon atoms.

[0043] The specific compound has a hydrocarbon group having 8 or more carbon atoms, and although there are no particular limitations on the structure other than the hydrocarbon group having 8 or more carbon atoms, it preferably contains a silicon atom from the viewpoint of liquid repellency.

[0044] Specifically, the specific compound preferably has a partial structure represented by the following formula (1). LYM-* …(1)

[0045] In formula (1), L is a hydrocarbon group having 8 or more carbon atoms. Y is a single bond or a divalent linking group. M is a metalloid or a metal; * indicates the bonding position with other structures.

[0046] Preferred embodiments of the hydrocarbon group having 8 or more carbon atoms represented by L are as described above.

[0047] Examples of the divalent linking group represented by Y include a combination of at least one selected from the group consisting of -O-, -C(=O)-, and NR-, with a hydrocarbon group. R represents a hydrogen atom or a hydrocarbon group. However, the linking portion of Y to L is not a hydrocarbon group.

[0048] When Y is a divalent linking group, examples of Y include: * 1 -OC(=O)-(hydrocarbon group)-C(=O)-O-(hydrocarbon group)-* 2 * 1 -O-(hydrocarbon group)-O-(hydrocarbon group)-* 2 * 1 -C(=O)-NH-(hydrocarbon group)-* 2 * 1 -NH-C(=O)-NH-(hydrocarbon group)-* 2 * 1 -OC(=O)-NH-(hydrocarbon group)-* 2 Examples include: * 1 indicates the bonding position with L, and * 2 means the bonding position with M.

[0049] The hydrocarbon group contained in the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Among these, the hydrocarbon group is preferably an aliphatic hydrocarbon group, and more preferably an alkylene group. The alkylene group may be any of a linear alkylene group, a branched alkylene group, and a cyclic alkylene group, but is preferably a linear alkylene group.

[0050] From the viewpoint of improving the durability of the liquid-repellent layer by further aggregating the hydrocarbon groups together, Y is preferably a single bond.

[0051] Examples of M include Si, Al, and Ti. Among these, M is preferably Si.

[0052] The liquid-repellent layer 52 is preferably formed using a compound represented by the following formula (2). LYX...(2) In formula (2), L is a hydrocarbon group having 8 or more carbon atoms. Y is a single bond or a divalent linking group. X is a group capable of forming a chemical bond with the intermediate layer.

[0053] Preferred embodiments of the hydrocarbon group having 8 or more carbon atoms represented by L are as described above. Preferred embodiments of the divalent linking group represented by Y are as described above. Y is preferably a single bond.

[0054] X may be, for example, a hydrolyzable silyl group.

[0055] The hydrolyzable silyl group is a group having a silicon atom and a hydrolyzable group directly bonded to the silicon atom. Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group. The hydrolyzable group is preferably a halogen atom or an alkoxy group, and more preferably an alkoxy group. Examples of halogen atoms include chlorine atoms, bromine atoms, and iodine atoms, with chlorine atoms being preferred. The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, and more preferably an alkoxy group having 1 to 3 carbon atoms. When the hydrolyzable group is an alkoxy group, the density of the liquid-repellent layer 52 is improved, and the alkali resistance is improved.

[0056] In particular, the liquid-repellent layer 52 is preferably formed using a compound represented by the following formula (2A). LY-Si(X 1 )3…(2A) In formula (2A), L is a hydrocarbon group having 8 or more carbon atoms. Y is a single bond or a divalent linking group. X 1 are each independently a halogen atom or an alkoxy group.

[0057] Preferred embodiments of the hydrocarbon group having 8 or more carbon atoms represented by L are as described above. Preferred embodiments of the divalent linking group represented by Y are as described above. Y is preferably a single bond. X 1 Preferred embodiments of the halogen atom and alkoxy group represented by the formula (I) are as described above. From the perspective of availability, three X 1 are preferably the same.

[0058] For example, by using a compound represented by formula (2A), it is possible to obtain a liquid-repellent layer 52 containing a compound having a partial structure represented by formula (1). The liquid-repellent layer 52 may contain a hydrolysate of the compound represented by formula (2A). The hydrolyzate of the compound represented by formula (2A) has an Si—O—Si bond, and further, the hydrocarbon groups having 8 or more carbon atoms aggregate, thereby improving the durability of the liquid-repellent layer 52.

[0059] The thickness of the liquid-repellent layer 52 is preferably 0.5 nm to 10 nm, and more preferably 1 nm to 3 nm. If the thickness of the liquid-repellent layer 52 is 3 nm or more, the wipe resistance is improved.

[0060] 1 and 2, the liquid ejection head 100 has an intermediate layer 51 on the inner wall 102 of the nozzle 30. The intermediate layer 51 provided on the inner wall 102 of the nozzle 30 is the same as the intermediate layer 51 provided on the ejection surface 101 of the nozzle substrate 10. On the inner wall 102 of the nozzle 30, the intermediate layer 51 is the outermost layer. The layer formed on the inner wall 102 of the nozzle 30 preferably does not contain fluorine compounds.

[0061] <Flow path substrate> The flow path substrate 20 is, for example, a substrate made of silicon, and may be a single crystal silicon substrate or a polycrystalline silicon substrate. As shown in Fig. 1, the flow path substrate 20 is made up of a wall member 21 and a lid member 22, and it is preferable that the wall member 21 and the lid member 22 are joined by adhesive or the like. A liquid flow path 40 that communicates with the nozzle 30 is formed in the flow path substrate 20. The liquid flow path 40 includes a nozzle communication path 41, a pressure chamber 42, and a liquid supply path 43.

[0062] The nozzle communication passage 41 is a flow path that connects the pressure chamber 42 and the nozzle 30. The nozzle communication passage 41 is preferably linear in cross section.

[0063] The pressure chamber 42 is a flow path whose volume changes when a drive voltage is applied. For example, the pressure chamber 42 has a substantially square planar shape when the liquid ejection head 100 is viewed from above, with a liquid outlet to the nozzle connecting path 41 provided at one of the diagonal corners and a liquid supply path 43 serving as a liquid inlet provided at the other. The planar shape of the pressure chamber 42 is not limited to a substantially square, and may be rectangular, trapezoidal, or the like.

[0064] The liquid supply path 43 is a flow path that is connected to a liquid tank (not shown) when the liquid ejection head 100 is incorporated into a liquid ejection device (described later). Liquid is supplied from the liquid tank to the pressure chamber 42 via the liquid supply path 43. The arrows in the figure indicate the direction in which the liquid flows. A liquid tank (not shown) and the liquid ejection head 100 are connected by, for example, a tube. It is preferable that the tube does not contain a fluorine compound.

[0065] The liquid ejection head 100 has an intermediate layer 51 on the inner wall 201 of the liquid flow path 40, similar to the intermediate layer 51 on the inner wall 102 of the nozzle 30 shown in Fig. 1. The intermediate layer 51 provided on the inner wall 201 of the liquid flow path 40 is the same as the intermediate layer 51 provided on the ejection surface 101 of the nozzle substrate 10. The inner wall 201 of the liquid flow path 40 specifically includes the surface of the wall member 21 on which the liquid flow path 40 is formed, the surface of the cover member 22 on which the liquid flow path 40 is formed, and the surface of the nozzle substrate 10 on which the liquid flow path 40 is formed. On the inner wall 201 of the liquid flow path 40, the intermediate layer 51 is the outermost layer. The layer formed on the inner wall 201 of the liquid flow path 40 preferably does not contain a fluorine compound.

[0066] The structure of the flow path substrate 20 may be, for example, the structure shown in Fig. 4 other than the structure shown in Fig. 1. Fig. 4 shows an example in which the intermediate layer 51 is made up of two layers, a first intermediate layer 51A and a second intermediate layer 51B.

[0067] FIG. 4 is a schematic cross-sectional view showing a modified example of the liquid ejection head of the present disclosure.

[0068] 4, the liquid ejection head 100A includes a nozzle substrate 10 and a flow path substrate 20A on which liquid flow paths 60 communicating with the nozzles 30 are formed. The nozzle substrate 10 is configured as described above. The liquid flow paths 60 include nozzle communication paths 61, pressure chambers 62, liquid supply paths 63, and circulation paths 64.

[0069] The nozzle communication passage 61 is similar to the nozzle communication passage 41 described above, and is a flow path that connects the pressure chamber 62 and the nozzle 30 .

[0070] The pressure chamber 62 is similar to the pressure chamber 42 described above, and is a flow path whose volume changes when a drive voltage is applied.

[0071] The liquid supply path 63 is similar to the above-described liquid supply path 43, and is a flow path that is connected to a liquid tank (not shown) when the liquid ejection head 100A is incorporated into a liquid ejection device described below. Liquid is supplied from the liquid tank to the pressure chamber 62 via the liquid supply path 63.

[0072] The circulation flow path 64 is a flow path that is connected to a liquid tank (not shown) when the liquid ejection head 100A is incorporated into a liquid ejection device described below. The liquid is sent to the nozzle 30 through the liquid supply path 63, the pressure chamber 62, and the nozzle communication path 61, but the liquid that is not ejected from the nozzle opening 31 of the nozzle 30 passes through the circulation flow path 64 and is collected in the liquid tank.

[0073] The liquid ejection head 100A has an intermediate layer 51 on the inner wall 201A of the liquid flow path 60, similar to the intermediate layer 51 on the inner wall 201 of the liquid flow path 40. The intermediate layer 51 provided on the inner wall 201A of the liquid flow path 60 is the same as the intermediate layer 51 provided on the inner wall 201 of the liquid flow path 40.

[0074] <Layer formation method> Next, a description will be given of methods for forming the first intermediate layer 51A, the second intermediate layer 51B, and the liquid-repellent layer 52 on the nozzle substrate 10, the nozzle 30, and the flow path substrate 20. The first intermediate layer 51A, the second intermediate layer 51B, and the liquid-repellent layer 52 are preferably formed after the nozzle substrate 10 and the flow path substrate 20 are bonded to obtain a bonded body. Note that even when there is only one intermediate layer, it can be formed in the same manner as when there are two layers. The method for forming the intermediate layer is not particularly limited, and may be atomic layer deposition (ALD) or chemical vapor deposition (CVD). The intermediate layer may also be formed by sputtering. When sputtering is used, it is preferable to form the intermediate layer separately on the nozzle substrate 10 and the flow path substrate 20, and then bond the nozzle substrate 10 and the flow path substrate 20 together.

[0075] First, before forming the first intermediate layer 51A on the surface of the assembly of the nozzle substrate 10 and the flow path substrate 20, it is preferable to perform a surface treatment on the surface of the assembly in advance. Examples of surface treatments include UV ozone treatment and oxygen plasma treatment. Of these, from the viewpoint of improving the adhesion between the assembly and the first layer, oxygen plasma treatment is preferable as the surface treatment. The conditions for oxygen plasma irradiation can be adjusted as appropriate, and are, for example, performed under conditions of an output of 100 W to 200 W, a flow rate of 50 mL / min to 200 mL / min, and an irradiation time of 1 minute to 10 minutes.

[0076] Next, a first intermediate layer 51A is formed on the surface of the surface-treated bonded body. Specifically, the first intermediate layer 51A is formed on the ejection surface 101 of the nozzle substrate 10, the inner wall 102 of the nozzle 30, and the inner wall 201 of the liquid flow path 40.

[0077] The first intermediate layer 51A is preferably formed by atomic layer deposition (ALD). Any known method can be used as the ALD. The ALD method forms a dense layer, which is highly effective in preventing penetration of alkaline liquid.

[0078] The first intermediate layer 51A can be formed, for example, by placing the surface-treated bonded body in an ALD chamber, introducing HO gas, and then repeatedly performing four steps: a step of introducing a precursor gas, a step of exhausting excess gas, a step of introducing HO gas, and a step of exhausting excess gas.

[0079] First, HO gas is introduced to form hydroxyl groups on the surface of the bonded body. Next, a precursor gas is introduced to cause the hydroxyl groups formed on the surface of the bonded body to react with the precursor. Further, HO gas is introduced to cause the precursor that has reacted with the hydroxyl groups to react with HO.

[0080] Examples of precursors used when forming a tantalum oxide layer as the first intermediate layer 51A include tert-butyliminotri(diethylamino)tantalum (TBTDET), tert-butyliminotri(dimethylamino)tantalum (TBTDMT), tert-butyliminotri(ethylmethylamino)tantalum (TBTEMT), ethyliminotri(diethylamino)tantalum (EITDET), ethyliminotri(dimethylamino)tantalum (EITDMT), ethyliminotri(ethylmethylamino)tantalum (EITEMT), tert-amyliminotri(dimethylamino)tantalum (TAIMAT), tert-amyliminotri(diethylamino)tantalum, pentakis(dimethylamino)tantalum, and tert-amyliminotri(ethylmethylamino)tantalum.

[0081] Precursors used when forming a zirconium oxide layer as the first intermediate layer 51A include, for example, tetrakis(N-ethylmethylamino)zirconium (TEMAZ) and tris(dimethylamino)cyclopentadienylzirconium (ZAC).

[0082] Precursors used when forming a titanium oxide layer as the first intermediate layer 51A include, for example, tetrakis(dimethylamino)titanium (TDMAT), tetrakis(diethylamino)titanium (TDEAT), and tetrakis(ethylmethylamino)titanium (TEMAT).

[0083] Precursors used when forming a hafnium oxide layer as the first intermediate layer 51A include, for example, tetrakis(dimethylamino)hafnium (TDMAHf), tetrakis(diethylamino)hafnium (TDEAHf), and tetrakis(ethylmethylamino)hafnium (TEMAHf).

[0084] Furthermore, when forming the first intermediate layer 51A, ozone gas may be used instead of H2O gas.

[0085] Next, the second intermediate layer 51B is formed on the first intermediate layer 51A.

[0086] The method for forming the second intermediate layer 51B is not particularly limited, and examples thereof include chemical vapor deposition (CVD). As the CVD method, a commonly known method can be used. As the method for forming the second intermediate layer 51B, it is more preferable to form it by atomic layer deposition (ALD). As the ALD method, a commonly known method can be used. When the ALD method is used, a dense layer is formed, which is highly effective in suppressing the penetration of alkaline liquid.

[0087] Next, the liquid-repellent layer 52 is formed on the second intermediate layer 51B.

[0088] The method for forming the liquid-repellent layer 52 is not particularly limited, but it is preferable to perform a hydrophilic treatment on the surface of the second intermediate layer 51B and then form the liquid-repellent layer 52 by a vapor deposition method using a composition for forming a liquid-repellent layer that contains a compound having a hydrocarbon group with 8 or more carbon atoms. The composition for forming the liquid-repellent layer may be a silane coupling agent (for example, a compound represented by the above formula (2A)). After the silane coupling agent is hydrolyzed, it bonds with the hydrophilic groups formed on the surface of the second intermediate layer 51B, thereby enhancing adhesion between the liquid-repellent layer 52 and the second intermediate layer 51B and inhibiting penetration of alkaline liquids.

[0089] Examples of hydrophilization treatments include UV ozone treatment and oxygen plasma treatment. Of these, oxygen plasma treatment is preferred. The irradiation conditions can be appropriately adjusted, and are, for example, performed under the conditions of an output of 100 W to 200 W, a flow rate of 50 mL / min to 200 mL / min, and an irradiation time of 1 minute to 10 minutes.

[0090] The deposition method can be performed by, for example, placing the bonded body in which the first intermediate layer 51A and the second intermediate layer 51B are laminated in a vacuum chamber and putting a silane coupling agent into a deposition boat. The deposition temperature is preferably 100°C to 300°C.

[0091] Furthermore, in order to further improve the adhesion between the second intermediate layer 51B and the liquid-repellent layer 52, the bonded body formed by laminating the first intermediate layer 51A, the second intermediate layer 51B, and the liquid-repellent layer 52 is preferably kept in a high-temperature, high-humidity environment after film formation. For example, the bonded body formed by laminating the first intermediate layer 51A, the second intermediate layer 51B, and the liquid-repellent layer 52 is kept at a temperature of 50 to 90°C and a relative humidity of 50% to 90% for 6 to 24 hours.

[0092] Next, the liquid-repellent layer 52 provided on the inner wall 102 of the nozzle 30 and the inner wall 201 of the liquid flow path 40 is removed.

[0093] For example, by applying tape to the surface of the liquid-repellent layer 52 provided on the ejection surface of the nozzle substrate 10 and performing oxygen plasma treatment on the nozzle 30 and the liquid flow path 40, the liquid-repellent layer 52 provided on the inner wall 102 of the nozzle 30 and the inner wall 201 of the liquid flow path 40 can be removed.

[0094] FIG. 5 is a cross-sectional view showing another embodiment of the liquid ejection head of the present disclosure.

[0095] As shown in FIG. 5, the liquid ejection head 500 further comprises a piezoelectric element 70 in addition to the liquid ejection head 100A.

[0096] The liquid ejection head 100A has the above-described configuration. The cover member 22 of the liquid ejection head 100A functions as a vibration plate in the liquid ejection head 500.

[0097] A piezoelectric element 70 having a laminated structure of a lower electrode 71, a piezoelectric layer 72, and an upper electrode 73 is disposed on the lid member (vibration plate) 22. The piezoelectric element 70 is provided above the pressure chamber 62.

[0098] The upper electrode 73 is an individual electrode patterned to correspond to the shape of the pressure chamber 62. When a drive voltage is applied to the upper electrode 73 of the piezoelectric element 70 provided above the pressure chamber 62 in accordance with input data, the piezoelectric element 70 and the lid member (vibration plate) 22 are deformed, changing the volume of the pressure chamber 62. Due to the change in pressure within the pressure chamber 62, liquid is ejected from the nozzle opening 31 of the nozzle 30 via the nozzle communication passage 61.

[0099] Instead of the piezoelectric element, a heater may be provided inside the pressure chamber 62 as a pressure generating element, and a driving voltage may be supplied to the heater to generate heat, causing the liquid in the pressure chamber 62 to be ejected from the nozzle opening 31 using the film boiling phenomenon.

[0100] [Liquid discharge device] The liquid ejection apparatus of the present disclosure includes a liquid ejection head, a conveying unit that conveys a substrate, and a drying unit that dries the liquid ejected onto the substrate. Hereinafter, an inkjet recording apparatus, which is an example of the liquid ejection apparatus, will be described.

[0101] An inkjet recording device includes, for example, a plurality of inkjet heads (an example of a liquid ejection head) provided for each ink color, an ink storage section for storing the ink to be supplied to each inkjet head, a paper feed section for supplying the substrate (recording paper), a decurling processing section for removing curls from the recording paper, a transport section arranged opposite the ejection surface of each inkjet head for transporting the recording paper, a drying section for drying the liquid (specifically, the ink) ejected onto the recording paper, an image detection section for reading the image recording results, and a paper ejection section for ejecting the recorded image to the outside.

[0102] The components of the inkjet recording device other than the inkjet head are the same as conventionally known components, and reference can be made to, for example, International Publication No. 2017 / 073526 and Japanese Patent Application Laid-Open No. 2022-049414.

[0103] The liquid ejection device of the present disclosure preferably has a liquid circulation mechanism for circulating the liquid between the liquid ejection head and the liquid tank. For example, by using a liquid ejection head including the liquid ejection head 100A shown in FIG. 4, the liquid can be circulated between the liquid ejection head and the liquid tank.

[0104] [Method of manufacturing the liquid ejection structure] The method for manufacturing a liquid ejection structure of the present disclosure involves forming a liquid-repellent layer by vapor deposition on an ejection surface of a nozzle substrate on which nozzles for ejecting liquid are formed, using a liquid-repellent layer-forming composition that includes a compound having a hydrocarbon group with 8 or more carbon atoms. The details of the nozzle substrate are as described above. The method for forming the liquid-repellent layer by vapor deposition is as described above. By forming the liquid repellent layer by vapor deposition, it is possible to manufacture a liquid ejection structure that is excellent in wipe resistance.

[0105] [Laminate] The laminate of the present disclosure has a substrate and a liquid-repellent layer disposed on the substrate, and the liquid-repellent layer contains a compound having a hydrocarbon group having 8 or more carbon atoms.

[0106] The preferred embodiment of the substrate is the same as the preferred embodiment of the nozzle substrate. An intermediate layer and a liquid-repellent layer may be laminated in this order on the substrate.

[0107] The laminate of the present disclosure is useful for a liquid ejection structure having an ejection surface with excellent wipe resistance. The laminate of the present disclosure can be applied to a liquid ejection structure by forming a nozzle for ejecting liquid. [Example]

[0108] Examples of the present disclosure will be described below, but the present disclosure is not limited to the following examples.

[0109] [Examples 1 to 8, Comparative Example 1] <Formation of the first intermediate layer> A nozzle substrate on which nozzles were formed and a flow path substrate on which liquid flow paths were formed were joined together to prepare a bonded assembly having the same structure as that shown in FIG. 4 and measuring 25 mm×35 mm.

[0110] Step (a1): Surface treatment The bonded body was placed in a vacuum chamber. After evacuating the vacuum chamber, the atmosphere was replaced with oxygen, and oxygen plasma was generated. The oxygen plasma irradiation conditions were a power of 30 W, a flow rate of 100 mL / min, and an irradiation time of 30 seconds.

[0111] Step (b1): Formation of hafnium oxide layer Next, the bonded structure after step (p1) was placed in an ALD (Atomic Layer Deposition) chamber, and HO gas was introduced to form hydroxyl groups on the surface of the bonded structure. Next, tetrakis(dimethylamino)hafnium (TDMAHf) gas was introduced, and the hydroxyl groups formed on the surface of the bonded structure reacted with the TDMAHf. The excess gas was then evacuated. Next, HO gas was introduced, and the TDMAHf that had bonded with the hydroxyl groups in the previous reaction reacted with HO. The excess gas was then evacuated. The cycle of introducing and evacuating TDMAHf gas, and introducing and evacuating HO gas, was repeated until a hafnium oxide layer reached the specified thickness (30 nm), forming a hafnium oxide layer.

[0112] <Formation of the second intermediate layer> Step (c1): Formation of silicon oxide film The bonded structure after step (b1) was placed in an ALD (Atomic Layer Deposition) chamber, and HO gas was introduced to form hydroxyl groups on the surface of the bonded structure. Next, tris(dimethylamino)silane (TDMAS) gas was introduced, and the hydroxyl groups formed on the surface of the bonded structure reacted with TDMAS. After that, excess gas was exhausted. Next, HO gas was introduced, and the TDMAS that had bonded with the hydroxyl groups in the previous reaction reacted with HO. After that, excess gas was exhausted. Then, the introduction and exhaust of TDMAS gas, and the introduction and exhaust of HO gas constituted one cycle, which was repeated until a silicon oxide layer reached the specified thickness (30 nm).

[0113] <Formation of liquid-repellent layer> Step (d1): Hydrophilic treatment Next, the bonded body after step (c1) was placed in a vacuum chamber. After evacuating the vacuum chamber, the atmosphere was replaced with oxygen, and oxygen plasma was generated. The oxygen plasma irradiation conditions were an output of 100 W, a flow rate of 100 mL / min, and an irradiation time of 1 minute.

[0114] Step (e1): Vapor deposition of silane coupling agent Next, the bonded body after step (d1) was placed in a deposition chamber. A silane coupling agent shown in Table 1 was added to the tungsten boat. When the temperature of the tungsten boat reached 70°C, the shutter was opened, and while monitoring the film thickness with a quartz crystal oscillator, the shutter was closed when the film thickness reached 3 nm, and the silane coupling agent was evaporated.

[0115] Step (f1): Store in a high temperature and humidity environment Next, to promote the hydrolysis reaction of the silane coupling agent and the condensation reaction between the bonded body and the silane coupling agent after step (e1), the bonded body was left to stand for 12 hours in an environment with a temperature of 60°C and humidity of 90%. The contact angle of the formed liquid-repellent layer with water was 60° or more. The contact angle with water was measured at 25°C using a fully automatic contact angle meter (product name "DM-701", manufactured by Kyowa Interface Science Co., Ltd.).

[0116] Step (g1): Removal of the liquid-repellent layer formed on the inner wall of the nozzle and the inner wall of the liquid flow path Next, tape was attached to the surface of the nozzle substrate in the assembly after step (f1), and oxygen plasma treatment was performed on the nozzle and liquid flow path from the side of the flow path substrate opposite to the side bonded to the nozzle substrate, thereby removing the liquid-repellent layers formed on the inner walls of the nozzle and the liquid flow path, and a liquid ejection structure was obtained. [Example 9] <Formation of the intermediate layer> After the step (a1), the step (c1) was carried out without carrying out the step (b1), thereby forming a silicon oxide layer.

[0117] <Formation of liquid-repellent layer> Thereafter, a liquid ejection structure was obtained in the same manner as in steps (d1) to (g1) of Example 1.

[0118] Details of the silane coupling agents listed in Table 1 are as follows: In Example 8, Compound 1 and Compound 2 were used in a mass ratio of 1:1.

[0119] (Compound 1) [ka]

[0120] (Compound 2) [ka]

[0121] (Compound 3) [ka]

[0122] (Compound 4) [ka]

[0123] (Compound 5) [ka]

[0124] (Compound 6) [ka]

[0125] (Compound 7) [ka]

[0126] (Compound A) [ka]

[0127] It was confirmed that the liquid-repellent layers in Examples 1 to 9 contained a compound having a partial structure represented by formula (1).

[0128] The liquid ejection structure thus obtained was evaluated for liquid repellency, wipe resistance, and alkali resistance of the ejection surface. The evaluation methods were as follows.

[0129] (liquid repellency) A black ink was prepared as described in paragraph

[0272] of JP 2015-180710 A. Sodium hydroxide was added to the prepared black ink to adjust the pH to 10, and the resulting ink was used for evaluation. The static contact angle of the surface of the liquid ejection structure was measured using the evaluation ink. The contact angle with the ink was measured at 25°C using a fully automatic contact angle meter (product name "DM-701", manufactured by Kyowa Interface Science Co., Ltd.). The evaluation criteria are as follows: The larger the contact angle, the better the liquid repellency. A: The contact angle is 60° or more and less than 90°. B: The contact angle is 55° or more and less than 60°. C: The contact angle is 50° or more and less than 55°. D: The contact angle is less than 50°.

[0130] (Wipe resistant) First, the static contact angle of the surface of the liquid ejection structure was measured using the ink for evaluation. The contact angle of the ink was measured at 25°C using a fully automatic contact angle meter (product name "DM-701", manufactured by Kyowa Interface Science Co., Ltd.). This contact angle was designated as the "contact angle before wiping." Next, the ink for evaluation was dropped onto a wiping member (product name "Toraysee", manufactured by Toray Industries, Inc.). The surface of the nozzle substrate of the fabricated liquid ejection structure was pressed against the dropped surface at a constant pressure of 40 kPa and slid back and forth. After 10,000 reciprocating strokes, the static contact angle of the nozzle substrate surface was measured using newly prepared ink for evaluation. This contact angle was defined as the "post-wipe contact angle." The contact angle change rate was calculated using the contact angle before wiping and the contact angle after wiping based on the following formula. Contact angle change rate (%) = {(contact angle before wiping - contact angle after wiping) / contact angle before wiping} x 100 The evaluation criteria are as follows: The smaller the rate of change in contact angle, the more excellent the wipe resistance. A: The contact angle change rate is less than 20%. B: The rate of change in contact angle is 20% or more and less than 30%. C: The rate of change in contact angle is 30% or more and less than 40%. D: The contact angle change rate is 40% or more.

[0131] (alkali resistance) First, the static contact angle of the surface of the liquid ejection structure was measured using the ink for evaluation. The contact angle of the ink was measured at 25°C using a fully automatic contact angle meter (product name "DM-701", manufactured by Kyowa Interface Science Co., Ltd.). This contact angle was defined as the "contact angle before immersion." Next, the prepared liquid ejection structure was immersed in the ink for evaluation and left to stand in a thermostatic chamber set at 60° C. After 200 hours had passed, the static contact angle on the nozzle substrate surface was measured using newly prepared ink for evaluation. This contact angle was defined as the "contact angle after immersion." The contact angle change rate was calculated using the contact angle before immersion and the contact angle after immersion based on the following formula. Contact angle change rate (%) = {(contact angle before immersion - contact angle after immersion) / contact angle before immersion} × 100 The evaluation criteria are as follows: The smaller the rate of change in contact angle, the more excellent the alkali resistance. A: The contact angle change rate is less than 20%. B: The rate of change in contact angle is 20% or more and less than 30%. C: The rate of change in contact angle is 30% or more and less than 40%. D: The contact angle change rate is 40% or more.

[0132] The evaluation results are shown in Table 1. Table 1 lists the number of carbon atoms in the hydrocarbon group of the compound contained in the liquid-repellent layer and the type. In addition, if the compound contained in the liquid-repellent layer contains a linking group other than the hydrocarbon group, it is marked with "Y", and if it does not contain a linking group, it is marked with "N".

[0133] [Table 1]

[0134] As shown in Table 1, in Examples 1 to 9, since the liquid-repellent layer contained a compound having a hydrocarbon group with 8 or more carbon atoms, it was found that the ejection surface had excellent wipe resistance. On the other hand, in Comparative Example 1, the liquid-repellent layer did not contain a compound having a hydrocarbon group with 8 or more carbon atoms, and it was found that the wiping resistance of the ejection surface was poor. [Explanation of symbols]

[0135] 10 Nozzle board 20, 20A flow path board 30 nozzles 31 Nozzle opening 21, 21A Wall components 22 Cover member (diaphragm) 40, 60 Liquid flow path 41, 61 Nozzle connecting passage 42, 62 Pressure chamber 43, 63 Liquid supply path 51 Middle Class 51A 1st middle layer 51B 2nd middle layer 52 Liquid repellent layer 64 Circulation flow path 70 Piezoelectric element 71 Lower electrode 72 Piezoelectric layer 73 Upper electrode 100, 100A liquid ejection head 101 Discharge surface 102, 201, 201A Interior wall 500 Liquid ejection head

Claims

1. a nozzle substrate on which nozzles for discharging liquid are formed; a liquid-repellent layer on the ejection surface of the nozzle substrate; The liquid ejection structure, wherein the liquid repellent layer contains a compound having a hydrocarbon group having 8 or more carbon atoms.

2. 2. The liquid ejection structure according to claim 1, wherein the compound having a hydrocarbon group having 8 or more carbon atoms has a partial structure represented by the following formula (1): LY-M-*…(1) In formula (1), L is a hydrocarbon group having 8 or more carbon atoms, Y is a single bond or a divalent linking group; M is a metalloid or a metal; * indicates the bonding position with other structures.

3. 2. The liquid ejection structure according to claim 1, wherein the hydrocarbon group having 8 or more carbon atoms is a linear alkyl group having 8 or more carbon atoms.

4. 3. The liquid ejection structure according to claim 2, wherein Y in the formula (1) is a single bond.

5. The liquid ejection structure according to claim 1 , further comprising an intermediate layer and a liquid-repellent layer in this order on the ejection surface of the nozzle substrate.

6. The intermediate layer is made of tantalum oxide, zirconium oxide, titanium oxide, hafnium oxide, SiO ２ 6. The liquid ejection structure according to claim 5, wherein the layer contains at least one material selected from the group consisting of SiC, SiN, SiCN, and SiON.

7. The intermediate layer is composed of two layers, The liquid ejection structure according to claim 5 , further comprising a first intermediate layer, a second intermediate layer, and the liquid-repellent layer, in this order, on the ejection surface.

8. the first intermediate layer is a layer containing at least one selected from the group consisting of tantalum oxide, zirconium oxide, titanium oxide, and hafnium oxide, The second intermediate layer is made of SiO ２ 8. The liquid ejection structure according to claim 7, wherein the layer contains at least one material selected from the group consisting of SiC, SiN, SiCN, and SiON.

9. 9. A liquid ejection head comprising: the liquid ejection structure according to claim 1; and a flow path substrate on which a liquid flow path communicating with the nozzle is formed.

10. The liquid ejection head according to claim 9 , further comprising a piezoelectric element.

11. 10. A liquid ejection device comprising: the liquid ejection head according to claim 9; a transport means for transporting a substrate; and a drying means for drying the liquid ejected onto the substrate.

12. A method for manufacturing a liquid ejection structure, comprising forming a liquid-repellent layer by a vapor deposition method on an ejection surface of a nozzle substrate on which nozzles for ejecting liquid are formed, using a liquid-repellent layer-forming composition containing a compound having a hydrocarbon group having 8 or more carbon atoms.

13. A substrate; a liquid-repellent layer disposed on the substrate; The liquid-repellent layer comprises a compound having a hydrocarbon group having 8 or more carbon atoms.

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