Liquid discharge head, method of manufacturing the same, and liquid discharge apparatus including the liquid discharge head

Abstract

To provide a liquid ejection head equipped with a protective film excellent in abrasion resistance and showing good water repellency even when abraded, a method for manufacturing the same, and a liquid ejector having the liquid ejection head.SOLUTION: A liquid ejection head 100 includes a nozzle plate 3 in which an ejection orifice 1 for ejecting a liquid is formed and a protective film 2 covering an ejection face is provided on the ejection face that is a face on a side from which the liquid is ejected, wherein the protective film contains an inorganic material and a water repellent material, and the water repellent material is present on an outermost face in a thickness direction of the protective film and a cut face of the protective film orthogonal to the thickness direction at a position of a depth 14nm from the outermost face.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head, a method for manufacturing the same, and a liquid ejection apparatus having the liquid ejection head. [Background technology]

[0002] A liquid ejection device is equipped with a liquid ejection head for ejecting liquid, and the liquid ejection device achieves a desired purpose by ejecting the liquid. For example, in an inkjet recording device, an inkjet recording head, which is a liquid ejection head, is mounted on a carriage, and ink is ejected from an ejection element substrate provided in the inkjet recording head to record images, characters, etc. on a recording medium. The inkjet recording head is equipped with a nozzle plate in which ejection openings (nozzles) for ejecting liquid are formed. In an inkjet recording head, if ink mist generated when ejecting liquid from the ejection openings adheres to the ejection surface of the nozzle plate, there is a risk of the liquid being ejected from the ejection openings varying in ejection direction. Therefore, in general liquid ejection heads, a water-repellent film is formed on the ejection surface of the nozzle plate to prevent ink from adhering to the periphery of the ejection openings, thereby reducing the risk of liquid ejection failure. However, if the ink resistance of the base on which the water-repellent film is formed is low, there is a risk of the water-repellent film peeling off.

[0003] Therefore, in Patent Document 1, a base film with high ink resistance is formed on the ejection surface of the nozzle plate on which the water-repellent film is to be formed, and then the water-repellent film is formed on the base film, thereby preventing the water-repellent film from peeling off.

[0004] Furthermore, some inkjet recording devices having inkjet recording heads are equipped with a wiping blade for wiping the ejection surface of the nozzle plate to remove ink adhering to the ejection surface. By forming a water-repellent film on the ejection surface and providing a wiping blade, ink adhesion to the ejection surface is suppressed, and even if ink does adhere to the ejection surface, it is removed by the wiping blade, thereby suppressing ejection defects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4692534 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when wiping the water-repellent film on the ejection surface with a wiping blade or the like, the sliding action of the wiping blade may cause the water-repellent components to be detached from the liquid-repellent film, which may reduce the water-repellent properties. In addition, because the film thickness of a typical water-repellent film is thin, at around 6 to 10 nm, it is difficult to adjust the film thickness taking into account the sliding action of the wiping blade.

[0007] In view of the above problems, the present invention aims to provide a liquid ejection head having a protective film that is highly wear-resistant and exhibits good water repellency even when worn, a method for manufacturing the same, and a liquid ejection device having the liquid ejection head. [Means for solving the problem]

[0008] The liquid ejection head of the present invention is a liquid ejection head having a nozzle plate in which ejection ports for ejecting liquid are formed, and in which a protective film is provided on an ejection surface, which is the surface from which the liquid is ejected, to cover the ejection surface, the protective film contains an inorganic material and a water-repellent material; The water-repellent material is present on the outermost surface of the protective film in the thickness direction and on a cut surface of the protective film perpendicular to the thickness direction at a depth of 14 nm from the outermost surface. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a liquid ejection head having a protective film that is highly abrasion resistant and exhibits good water repellency even when worn, a method for manufacturing the same, and a liquid ejection device having the liquid ejection head. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing a cross section of the liquid ejection head. [Figure 2] FIG. [Figure 3] Enlarged view of the protective film. [Figure 4] Enlarged view of the protective film. [Figure 5] FIG. 1 is a flow chart showing the formation of a protective film. [Figure 6] Enlarged view of the protective film. [Figure 7] XPS analysis results of the protective film. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments do not limit the subject matter of the present invention, and not all combinations of features described in the embodiments are necessarily essential to the solution of the present invention. Note that the same reference numerals are used to denote the same components.

[0012] In the present disclosure, unless otherwise specified, the expression "XX to YY" representing a numerical range means a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, in the present disclosure, for example, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0013] (liquid ejection head) The liquid ejection head according to this embodiment is an inkjet recording head that ejects ink, but is not limited to this as long as it ejects liquid. Since ink adhesion to the ejection surface of an inkjet recording head causes ejection defects and is particularly problematic, the liquid ejection head according to this embodiment is suitable for use as an inkjet recording head.

[0014] FIG. 1 is a perspective view showing a cross section of a liquid ejection head 100, and FIG. 2 is a cross-sectional view of the liquid ejection head 100. The liquid ejection head 100 has a nozzle plate 3 in which a plurality of ejection ports 1 (nozzles) for ejecting liquid are formed, and a protective film 2 is provided on the ejection surface, which is the surface from which the liquid is ejected. The nozzle plate 3 may be a member in which flow paths for supplying liquid to the ejection ports are formed. The protective film 2 will be described in detail later. The liquid ejection head 100 includes a pressure chamber forming substrate 5 that forms pressure chambers 11 that apply pressure to the liquid ejected from the ejection ports 1, and an actuator substrate 6 that has flow paths 12 that supply liquid to the pressure chambers 11 and is provided with ejection elements 7 that generate pressure for ejecting the liquid. The ejection elements 7 may be of a thermal type that generates pressure for ejecting liquid using a thermoelectric conversion element, or a piezoelectric type that generates pressure for ejecting liquid using a piezoelectric element. Various other liquid ejection methods may also be used.

[0015] The nozzle plate 3 and the pressure chamber forming substrate 5, and the pressure chamber forming substrate 5 and the actuator substrate 6 are each bonded with an adhesive 4. There are no particular restrictions on the adhesive 4, but it is preferable that it is an adhesive that is ink-resistant, and in particular, an adhesive that has a benzocyclobutene skeleton. There are also no particular restrictions on the materials that the nozzle plate 3, the pressure chamber forming substrate 5, and the actuator substrate 6 are made of, but silicon, SUS, or a resin material are preferred, as these can be formed with high precision.

[0016] The flow channels and the discharge ports can be formed by dry etching the respective substrates, but are not limited to this.Furthermore, the shapes of the flow channels and the discharge ports are not particularly limited.

[0017] (protective film) Next, the protective film 2, a characteristic feature of the present invention, will be described. The protective film 2 according to this embodiment contains an inorganic material. The inorganic material is preferably a simple substance, oxide, nitride, or carbide of at least one inorganic element selected from the group consisting of Ta, Ti, Zr, Nb, V, Hf, and Si. Among these, it is preferable to contain at least one compound selected from the group consisting of TaO, TiO, SiOC, SiC, SiCN, TaN, and TiN, and among these, a metal oxide is preferable. These materials have high ink resistance and excellent abrasion resistance, so even when a liquid ejection head is provided in a liquid ejection device having a wiping blade for wiping the ejection surface, the risk of the protective film being worn can be reduced even when the ejection surface is wiped.

[0018] The protective film 2 according to this embodiment further contains a water-repellent material. The water-repellent material is not particularly limited as long as the static contact angle of pure water with the protective film containing the water-repellent material is 90° or more, but is preferably 100° or more. Compounds containing perfluoropolyether chains exhibit good water repellency and are therefore suitable as the water-repellent material according to this embodiment.

[0019] FIG. 3 is an enlarged view of the protective film 2 of this embodiment. The protective film 2 of this embodiment contains an inorganic material 14 and a water-repellent material 9. The water-repellent material 9 is not only formed on the outermost surface of the protective film 2 in the thickness direction, but also exists inside the protective film 2. Specifically, the water-repellent material 9 is also present on a cut surface of the protective film perpendicular to the thickness direction at a depth of 14 nm from the outermost surface. Therefore, the outermost surface of the protective film 2 exhibits good water repellency. Even if the protective film 2 is wiped and worn, causing a portion of the water-repellent material 9 on the outermost surface to detach, the water-repellent material 9 that was present inside the protective film 2 appears on the surface, thereby preventing a decrease in water repellency. Hereinafter, unless otherwise specified, the cut surface refers to the surface of the protective film perpendicular to the thickness direction at a depth of 14 nm from the outermost surface of the protective film 2.

[0020] To enhance the water repellency of the protective film 2, it is preferable that the concentration of the water repellent material is high. On the other hand, as the concentration of the water repellent material contained in the protective film 2 increases, the adhesion between the protective film 2 and the nozzle plate 3 decreases. Therefore, it is preferable that the concentration of the water repellent material on the outermost surface is higher than the concentration of the water repellent material on the cut surface. This allows the outermost surface of the protective film 2 to exhibit high water repellency while improving the adhesion between the protective film 2 and the nozzle plate 3.

[0021] Furthermore, while the ejection surface of a liquid ejection head is initially free of ink before use, ink mist gradually adheres to the surface as the liquid ejection head is used. In other words, the problem of ink mist adhering to the liquid ejection head becomes more pronounced as the liquid ejection head is used over a long period of time. At the same time, as the liquid ejection head is used over a long period of time, the protective film 2 is wiped more frequently with a wiping blade or the like, and the protective film 2 is worn down more frequently. Therefore, to enhance the water-repellent properties of the protective film 2 after a long period of use of the liquid ejection head, the concentration of the water-repellent material on the cut surface may be made higher than the concentration of the water-repellent material on the outermost surface.

[0022] Here, the concentration of the water-repellent material on the cut surface and the outermost surface is the average value of the concentration of the water-repellent material on each of the cut surface and the outermost surface. Note that the outermost surface may not be a completely flat surface, and may have minute irregularities formed in some parts. In this case, the outermost surface is defined as a curved surface including the minute irregularities.

[0023] Next, we will explain the use of a compound containing a perfluoropolyether chain as a water-repellent material. Compounds containing perfluoropolyether chains generally contain fluorine atoms that exhibit water-repellent properties, and the water-repellent properties of compounds containing perfluoropolyether chains are due to the fluorine atoms. On the other hand, compounds containing perfluoropolyether chains also contain oxygen atoms in addition to fluorine atoms. Oxygen atoms generally exhibit hydrophilic properties, contrary to fluorine atoms. Therefore, when using a compound containing perfluoropolyether chains as a water-repellent material, the ratio of fluorine atoms to oxygen atoms at the cut surface of the protective film 2 is important as an indicator of water-repellency. Furthermore, when an oxide is used as the inorganic material for the protective film 2, the proportion of oxygen atoms present in the protective film 2 increases, making the protective film 2 more hydrophilic. Therefore, in order for the protective film 2 of this embodiment to exhibit good water-repellency, the ratio of fluorine atoms to oxygen atoms at the cut surface is preferably 2.0% or more and 20.0% or less. When the ratio of fluorine atoms to oxygen atoms at the cut surface is 2.0% or more and 20.0% or less, the static contact angle of pure water on the protective film 2 is 90° or more, indicating good water-repellency. On the other hand, if the ratio of fluorine atoms to oxygen atoms on the cut surface is less than 2.0%, good water repellency is not exhibited, and if it is greater than 20.0%, the abrasion resistance of the protective film 2 decreases.

[0024] If the ratio of fluorine atoms to oxygen atoms at the contact surface of the protective film 2 that comes into contact with the nozzle plate 3 is large, the adhesion between the nozzle plate 3 and the protective film 2 will decrease. Therefore, as shown in Fig. 4, it is preferable that the ratio of fluorine atoms to oxygen atoms at the contact surface be 1.0% or less.

[0025] Furthermore, as described above, since the protective film 2 is formed from an inorganic material and a water-repellent material, the film thickness can be controlled. The thickness of the protective film 2 is not particularly limited as long as it is thicker than 15 nm, but considering the wear of the protective film 2, it is preferably 30 nm or more. Furthermore, considering the manufacturing takt time for forming the protective film 2, it is preferable that the thickness of the protective film 2 is 190 nm or less. In other words, the thickness of the protective film 2 is preferably 30 nm or more and 190 nm or less.

[0026] (Protective Film and Method for Manufacturing Liquid Ejection Head Having the Protective Film) FIG. 5 is a diagram showing an example of a method for manufacturing the protective film 2 (protective film forming process). In FIG. 5, the process of forming a film of the inorganic material of the protective film 2 is referred to as the first film forming process, and the process of forming a film of the water-repellent material of the protective film 2 is referred to as the second film forming process. The first film forming process is started before the second film forming process. The second film forming process is started midway through the first film forming process, and the first and second film forming processes end simultaneously, completing the film formation. By using such a film forming process, it is possible to reduce the concentration of the water-repellent material on the contact surface of the protective film 2 that comes into contact with the nozzle plate 3, while increasing the concentration of the water-repellent material on the outermost surface of the protective film 2. Furthermore, because the water-repellent material is formed so that it is present even on the cut surface of the protective film 2, it is possible to form a protective film that exhibits good water repellency even when the protective film 2 is wiped with a wiping blade or the like. In order to form a protective film such that the water-repellent material is present on the cut surface of the protective film 2, there must be a moment when at least a part of the first film-forming step and at least a part of the second film-forming step are carried out simultaneously. The presence of a moment when the first film-forming step and the second film-forming step are carried out simultaneously means that the water-repellent material is added to the interior (cut surface) of the protective film 2, making it possible to form a protective film 2 with good water-repellent properties on the cut surface.

[0027] 5, the first film formation process is started before the second film formation process, but it may be started simultaneously with the second film formation process. When the first film formation process is started before the second film formation process, it is possible to form a protective film 2 in which the ratio of fluorine atoms to oxygen atoms on the contact surface of the protective film 2 that comes into contact with the nozzle plate 3 is 1.0% or less, as shown in FIG. In this way, by reducing the concentration of the water-repellent material on the contact surface of the protective film that comes into contact with the nozzle plate 3, it is possible to improve the adhesion between the nozzle plate 3 and the protective film 2.

[0028] 5, the second film formation process is completed simultaneously with the first film formation process, but the second film formation process may be completed after the first film formation process. By completing the second film formation process after the first film formation process, a water-repellent film can be formed to cover the protective film 2. Furthermore, by completing the first film formation process and the second film formation process simultaneously, the protective film is formed so that the water-repellent material is present on the outermost surface of the protective film 2, thereby improving the water repellency of the protective film on the outermost surface.

[0029] The protective film 2 according to this embodiment can be formed by a physical vapor deposition method such as a vapor deposition method. In other words, the first film formation process and the second film formation process can be formed by a physical vapor deposition method such as a vapor deposition method. For example, in the vapor deposition method, the nozzle plate 3 is placed in a vacuum chamber, and a water-repellent material and an inorganic material prepared in the same vacuum chamber are vaporized using a method suited to the materials, such as resistive heating or electron beam heating, and the vaporized materials are then attached to the nozzle plate 3 to form the film.

[0030] 6, the protective film 2 and the nozzle plate 3 may be in contact with each other via an underlayer 8. By performing the process of forming the underlayer 8 separately from the process of forming the protective film 2, the underlayer 8 can be configured not to contain a water-repellent material. Because the underlayer 8 does not contain a water-repellent material, the nozzle plate 3 and the underlayer 8 can be adhered to each other with high adhesive strength. Furthermore, the underlayer 8 can also be adhered to the protective film 2 with high adhesive strength, which leads to an increase in adhesive strength between the nozzle plate 3 and the protective film 2. As the underlayer 8, for example, a TaO film formed by the ALD method can be used.

[0031] Furthermore, to manufacture a liquid ejection head 1 having a protective film 2, the above-described protective film forming step of forming a protective film on the ejection surface of the nozzle plate, which is the surface from which the liquid is ejected, is included after the preparation step of preparing an ejection port substrate in which ejection ports for ejecting liquid are formed. Note that the preparation step may involve preparing a nozzle plate 3 in which ejection ports are formed, and then performing the protective film forming step on the nozzle plate 3 in which the ejection ports are formed. Alternatively, the preparation step may include an ejection port forming step of forming ejection ports in the nozzle plate, and the ejection port forming step may be performed after the protective film forming step. In other words, the ejection port forming step may be performed after performing the protective film forming step on a nozzle plate in which no ejection ports are formed. The ejection port forming step can be performed by dry etching the substrate as described above, but is not limited to this.

[0032] (Liquid discharge device) The liquid ejection device according to this embodiment has a liquid ejection head 1 having the above-described protective film 2, and a wiping blade (wiping member) for wiping the ejection port surface via the protective film 2. The protective film 2 according to this embodiment is suitable for a liquid ejection device equipped with a wiping member because the decrease in water repellency is suppressed even when the protective film 2 is worn down by wiping with the wiping member. The material of the wiping blade is not particularly limited as long as it has a hardness that does not destroy the protective film 2 when wiping it.

[0033] Although the wiping blade has been described in this embodiment, it is not limited to a member that can wipe the ejection surface. For example, it may be a member that wipes the ejection surface of the nozzle plate 3 with a cloth or a member that wipes the ejection surface of the nozzle plate 3 with a brush. [Example]

[0034] In each example, a protective film was formed by a different manufacturing method, and the liquid ejection head 10 was manufactured. Details are given below.

[0035] Example 1 First, a nozzle plate 3 having ejection ports for ejecting liquid was prepared, and then bonded to an actuator substrate 6 and a pressure chamber forming substrate 5 via an adhesive 4. Hereinafter, the member formed by bonding the nozzle plate 3, pressure chamber forming substrate 5, and actuator substrate 6 will be referred to as a laminated member. Next, a protective film formation process was carried out. A first film formation process for depositing an inorganic material film and a second film formation process for depositing a water-repellent material film were started simultaneously in the same furnace, and the first film formation process and the second film formation process were completed simultaneously.

[0036] The first film formation process was carried out by vacuum evaporation using tantalum oxide (TaO) as the inorganic material, taking into consideration chemical resistance. First, a container containing the ejection element substrate and pellets made by pressing tantalum pentoxide powder was placed inside the device, and the device was evacuated to create a vacuum. After that, the inorganic material was evaporated by electron beam bombardment, and the first protective film process was carried out by the ion-assisted method, which introduced oxygen using an ion gun. At this time, the back pressure inside the device was 3 x 10 -3 The pressure was set to 0.1 Pa or less, the ejection element substrate was not heated during film formation, and the electron beam output was controlled using a quartz oscillator so that the film formation rate was kept constant at 3 Å / s.

[0037] The second film formation process was performed by resistance heating vapor deposition using a compound containing perfluoropolyether chains as a water-repellent material. Resistance heat was generated by passing a 200A current through the heating chamber for 1 minute, volatilizing the compound containing perfluoropolyether chains to form a film. The deposition rate was controlled by controlling the current.

[0038] A protective film 2 with a thickness of 50 nm was formed through the first and second film formation processes. Figure 7 shows the results of analyzing the formed protective film 2 using the XPS method. The horizontal axis represents the depth of the protective film, and the vertical axis represents the ratio of fluorine atoms to oxygen atoms in the protective film 2. Figure 6 shows that approximately 10% of fluorine atoms are present on the cut surface of the protective film 2 at a depth of 14 nm from the outermost surface. In other words, the water-repellent material is present on the cut surface of the protective film 2 at a depth of 14 nm from the outermost surface. Therefore, even if the protective film 2 is worn by a sliding action such as a wiping blade, the water-repellent material on the cut surface allows the water-repellent material to be maintained. Furthermore, when a wiping blade made of HNBR was used to penetrate the protective film at a depth of 0.5 mm and wiped at 100 mm / sec, no wear of the protective film was observed. This means that the protective film 2 has sufficient wear resistance. Furthermore, the static contact angle on the cut surface of the protective film at a depth of 14 nm from the outermost surface was greater than 90°. That is, it is understood that even if the protective film 2 is slid under more severe conditions and the protective film is worn, it still exhibits good water repellency.

[0039] Therefore, it was possible to manufacture a liquid ejection head provided with a protective film that is excellent in abrasion resistance and exhibits good water repellency even when worn.

[0040] Example 2 In the following explanation, only the parts that are different from the first embodiment will be mainly explained, and explanations of the parts that are the same as the first embodiment will be omitted.

[0041] Example 2 differs from Example 1 in that the second film-forming process was started 30 seconds after the first film-forming process in order to reduce the concentration of the water-repellent material on the contact surface of the protective film with the nozzle plate. That is, the first film-forming process and the second film-forming process were started according to the flow shown in Fig. 5, and the first film-forming process and the second film-forming process were completed simultaneously.

[0042] The formed protective film 2 was analyzed by XPS in the same manner as in Example 1. As a result, the ratio of fluorine atoms to oxygen atoms in the protective film at a position 14 nm from the outermost surface was approximately 8%. In other words, the water-repellent material was present even on the cut surface of the protective film 2 at a depth of 14 nm from the outermost surface. That is, even if the protective film 2 is worn by a sliding action such as a wiping blade, the water-repellent material is present on the cut surface, allowing the water-repellent property to be maintained. When the protective film 2 was wiped under the same conditions as in Example 1, no wear of the protective film was observed. That is, the protective film 2 has sufficient wear resistance. Furthermore, the static contact angle of the cut surface at a position 14 nm deep from the outermost surface of the protective film was 85° or more. That is, it can be seen that the protective film 2 exhibits good water-repellent properties even when worn by sliding under harsher conditions.

[0043] Furthermore, the ratio of fluorine atoms to oxygen atoms on the contact surface of the protective film that comes into contact with the nozzle plate was 1.0% or less, and the adhesion between the nozzle plate 3 and the protective film 2 was improved compared to Example 1.

[0044] Therefore, by using a manufacturing method in which the first film formation process is performed prior to the second film formation process, it was possible to manufacture a liquid ejection head equipped with a protective film that has excellent abrasion resistance and exhibits good water repellency even when worn.

[0045] Example 3 In the following explanation, only the parts that are different from the first embodiment will be mainly explained, and explanations of the parts that are the same as the first embodiment will be omitted.

[0046] Example 3 differs from Example 1 in that the protective film is not formed directly on the nozzle plate 3, but an underlayer 8 is formed on the nozzle plate 3, and then a protective film 2 is formed thereon.

[0047] Next, a TaO film was formed on the prepared nozzle plate 3 by thermal ALD using a Ta material and an oxidizer. This film formation was performed by alternately supplying the Ta material and the oxidizer. The film formation cycle consisted of vaporizing the Ta material, transporting it into the furnace together with nitrogen, spraying it for 2.5 seconds, followed by thorough purging with nitrogen and exhausting. Next, vaporizing the oxidizer gas, transporting it into the furnace together with nitrogen, spraying it for 5 seconds, followed by thorough purging with nitrogen and exhausting. This cycle constituted one cycle, and was repeated 200 times. The film formation temperature was controlled at 230°C ± 10°C, and a tantalum oxide film was formed to a thickness of 130 nm from the surface of the nozzle plate 3. Next, a protective film 2 with a thickness of 40 nm was formed using the method described in Example 1.

[0048] The formed protective film 2 was analyzed by XPS in the same manner as in Example 1. As a result, the ratio of fluorine atoms to oxygen atoms in the protective film at a position 14 nm from the outermost surface was approximately 10%. In other words, the water-repellent material was present even on the cut surface of the protective film 2 at a depth of 14 nm from the outermost surface. That is, even if the protective film 2 is worn by a sliding action such as a wiping blade, the water-repellent material is present on the cut surface, allowing the water-repellent property to be maintained. When the protective film 2 was wiped under the same conditions as in Example 1, no wear of the protective film was observed. That is, the protective film 2 has sufficient wear resistance. Furthermore, the static contact angle of the cut surface at a position 14 nm deep from the outermost surface of the protective film was 85° or more. That is, it can be seen that the protective film 2 exhibits good water-repellent properties even when worn by sliding under harsher conditions.

[0049] Furthermore, in this embodiment, the presence of the base layer 8 improves the adhesion between the nozzle plate 3 and the protective film 2 via the base layer 8 .

[0050] Therefore, even when a base layer 8 is formed between the nozzle plate 3 and the protective film 2, it is possible to manufacture a liquid ejection head equipped with a protective film that has excellent abrasion resistance and exhibits good water repellency even when worn.

[0051] As described above, according to the present invention, it is possible to provide a liquid ejection head having a protective film that is highly resistant to wear and exhibits good water repellency even when worn, a method for manufacturing the same, and a liquid ejection device having the liquid ejection head.

[0052] To summarize the present invention, the present invention includes the following methods and configurations.

[0053] (Configuration 1) A liquid ejection head having a nozzle plate in which ejection ports for ejecting liquid are formed, and in which a protective film is provided on an ejection surface that is a surface from which liquid is ejected, and that covers the ejection surface, the protective film contains an inorganic material and a water-repellent material; A liquid ejection head characterized in that the water-repellent material is present on the outermost surface of the protective film in the thickness direction and on a cut surface of the protective film perpendicular to the thickness direction at a depth of 14 nm from the outermost surface.

[0054] (Configuration 2) 2. The liquid ejection head according to claim 1, wherein the inorganic material is a simple substance, oxide, nitride, or carbide of at least one element selected from the group consisting of Ta, Ti, Zr, Nb, V, Hf, and Si.

[0055] (Configuration 3) 3. The liquid ejection head according to claim 1, wherein the inorganic material is at least one compound selected from the group consisting of TaO, TiO, SiOC, SiC, SiCN, TaN, and TiN.

[0056] (Configuration 4) 4. The liquid ejection head according to any one of configurations 1 to 3, wherein the protective film has a thickness of 30 nm or more.

[0057] (Configuration 5) 5. The liquid ejection head according to any one of configurations 1 to 4, wherein the protective film has a thickness of 190 nm or less.

[0058] (Configuration 6) 6. The liquid ejection head according to any one of configurations 1 to 5, wherein the concentration of the water-repellent material on the outermost surface is higher than the concentration of the water-repellent material on the cut surface.

[0059] (Configuration 7) 6. The liquid ejection head according to any one of configurations 1 to 5, wherein the concentration of the water-repellent material on the outermost surface is lower than the concentration of the water-repellent material on the cut surface.

[0060] (Configuration 8) 8. The liquid ejection head according to any one of configurations 1 to 7, wherein the water-repellent material is a compound containing a perfluoropolyether chain.

[0061] (Configuration 9) 9. The liquid ejection head according to any one of configurations 1 to 8, wherein the inorganic material is a metal oxide.

[0062] (Configuration 10) 10. The liquid ejection head according to any one of configurations 1 to 9, wherein the ratio of fluorine atoms to oxygen atoms in the cut surface is 2.0% or more and 20.0% or less.

[0063] (Configuration 11) 11. The liquid ejection head according to any one of configurations 1 to 10, wherein the ratio of fluorine atoms to oxygen atoms on the contact surface of the protective film that comes into contact with the nozzle plate is 1.0% or less.

[0064] (Configuration 12) 12. The liquid ejection head according to any one of configurations 1 to 11, wherein the ratio of fluorine atoms to oxygen atoms on the contact surface of the protective film that comes into contact with the nozzle plate is 1.0% or less.

[0065] (Configuration 13) a liquid ejection head according to any one of configurations 1 to 12; a wiping member for wiping the ejection surface through the protective film; A liquid ejection device comprising:

[0066] (Method 1) A method for manufacturing a liquid ejection head, comprising: a preparation step of preparing a nozzle plate in which ejection ports for ejecting liquid are formed; a protective film forming step of forming a protective film on the ejection surface of the nozzle plate, which is the surface from which the liquid is ejected; Including, the protective film contains an inorganic material and a water-repellent material; the protective film forming step further includes a first film forming step of forming a film of the inorganic material and a second film forming step of forming a film of the water-repellent material, A method for manufacturing a liquid ejection head, characterized in that there is a moment when at least a part of the first film-forming step and at least a part of the second film-forming step are performed simultaneously.

[0067] (Method 2) The method for manufacturing a liquid ejection head according to Method 1, wherein the first film-forming step is started prior to or simultaneously with the second film-forming step.

[0068] (Method 3) 3. The method for manufacturing a liquid ejection head according to Method 1 or 2, wherein the first film-forming step is started prior to the second film-forming step.

[0069] (Method 4) 4. The method for manufacturing a liquid ejection head according to any one of methods 1 to 3, wherein the second film-forming step is completed after the first film-forming step or simultaneously with the first film-forming step.

[0070] (Method 5) 5. The method for manufacturing a liquid ejection head according to any one of methods 1 to 4, wherein the second film forming step is completed simultaneously with the first film forming step.

[0071] (Method 6) 6. The method for manufacturing a liquid ejection head according to any one of Methods 1 to 5, wherein the preparation step includes preparing the nozzle plate in which the ejection ports are formed. [Explanation of symbols]

[0072] 1 outlet 2 Protective film 3 Nozzle Plate 4. Adhesive 5. Pressure chamber forming substrate 6 Actuator board 9. Water-repellent materials 14 Inorganic materials 100 Liquid ejection head

Claims

1. A liquid ejection head having a nozzle plate in which ejection ports for ejecting liquid are formed, and in which a protective film is provided on an ejection surface that is a surface from which liquid is ejected, and that covers the ejection surface, the protective film contains an inorganic material and a water-repellent material; A liquid ejection head characterized in that the water-repellent material is present on the outermost surface of the protective film in the thickness direction and on a cut surface of the protective film perpendicular to the thickness direction at a depth of 14 nm from the outermost surface.

2. 2. The liquid ejection head according to claim 1, wherein the inorganic material is a simple substance, oxide, nitride or carbide of at least one element selected from the group consisting of Ta, Ti, Zr, Nb, V, Hf and Si.

3. 3. The liquid ejection head according to claim 2, wherein the inorganic material is at least one compound selected from the group consisting of TaO, TiO, SiOC, SiC, SiCN, TaN, and TiN.

4. 2. The liquid ejection head according to claim 1, wherein the protective film has a thickness of 30 nm or more.

5. 2. The liquid ejection head according to claim 1, wherein the protective film has a thickness of 190 nm or less.

6. The liquid ejection head according to claim 1 , wherein the concentration of the water-repellent material on the outermost surface is higher than the concentration of the water-repellent material on the cut surface.

7. The liquid ejection head according to claim 1 , wherein the concentration of the water-repellent material on the outermost surface is lower than the concentration of the water-repellent material on the cut surface.

8. 2. The liquid ejection head according to claim 1, wherein the water-repellent material is a compound containing a perfluoropolyether chain.

9. 4. The liquid ejection head according to claim 3, wherein the inorganic material is a metal oxide.

10. 9. The liquid ejection head according to claim 8, wherein the ratio of fluorine atoms to oxygen atoms on the cut surface is 2.0% or more and 20.0% or less.

11. 10. The liquid ejection head according to claim 9, wherein the ratio of fluorine atoms to oxygen atoms on the cut surface is 2.0% or more and 20.0% or less.

12. 9. The liquid ejection head according to claim 8, wherein the ratio of fluorine atoms to oxygen atoms on the contact surface of said protective film that comes into contact with said nozzle plate is 1.0% or less.

13. 10. The liquid ejection head according to claim 9, wherein the ratio of fluorine atoms to oxygen atoms on the contact surface of the protective film that comes into contact with the nozzle plate is 1.0% or less.

14. A liquid ejection head according to any one of claims 1 to 13, a wiping member for wiping the ejection surface through the protective film; A liquid ejection device comprising:

15. A method for manufacturing a liquid ejection head, comprising: a preparation step of preparing a nozzle plate in which ejection ports for ejecting liquid are formed; a protective film forming step of forming a protective film on the ejection surface of the nozzle plate, which is the surface from which the liquid is ejected; Including, the protective film contains an inorganic material and a water-repellent material; the protective film forming step further includes a first film forming step of forming a film of the inorganic material and a second film forming step of forming a film of the water-repellent material, A method for manufacturing a liquid ejection head, characterized in that there is a moment when at least a part of the first film-forming step and at least a part of the second film-forming step are performed simultaneously.

16. The method for manufacturing a liquid ejection head according to claim 15, wherein the first film-forming step is started prior to or simultaneously with the second film-forming step.

17. The method for manufacturing a liquid ejection head according to claim 15, wherein the first film-forming step is started prior to the second film-forming step.

18. The method for manufacturing a liquid ejection head according to claim 15, wherein the second film forming step is completed after the first film forming step or simultaneously with the first film forming step.

19. The method for manufacturing a liquid ejection head according to claim 15, wherein the second film forming step is completed simultaneously with the first film forming step.

20. The method for manufacturing a liquid ejection head according to claim 15 , wherein the preparation step includes preparing the nozzle plate in which the ejection ports are formed.

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