Liquid ejection head and method of producing liquid ejection head

Abstract

To provide a liquid ejection head that can prevent permeation of ink into a channel forming member, so that peeling of the channel forming member from a substrate can be suppressed even when ink with high permeability is used, and that has excellent pattern reproducibility and satisfactory print quality.SOLUTION: In a liquid ejection head that includes an ejection port forming member and a channel forming member provided on a substrate, the channel forming member is a cured product of a photosensitive resin composition comprising a resin and a compound containing a ligand having a lone electron pair, and is in contact with the substrate having an inorganic material layer on a surface thereof, and the content of the compound containing the ligand having a lone electron pair is in a range of 1.0 mass% to 5.0 mass% with respect to 100 mass% of an epoxy resin contained in the photosensitive resin composition.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head and a method for manufacturing a liquid ejection head. [Background technology]

[0002] A liquid ejection head that ejects liquid is used in a liquid ejection device such as an inkjet recording device, and has an ejection port forming member, a flow path forming member, and a substrate. The flow path forming member is provided on the substrate, defines a flow path for the liquid, and in many cases has a liquid ejection port that communicates with the flow path. The substrate is formed with a liquid supply port that communicates with the flow path of the flow path forming member, and also has an energy generating element on the surface side that generates ejection energy. The liquid is supplied to the flow path from the liquid supply port, energy is given by the energy generating element, and the liquid is ejected from the liquid ejection port and lands on a recording medium such as paper, thereby forming an image.

[0003] In many cases, an inorganic material layer is provided on the substrate as an insulating layer or a protective layer covering the energy generating element, or for various other purposes. On the other hand, it is known to form flow path forming members and other structures on the substrate with an organic material layer. In particular, when the organic material layer is formed with a photosensitive resin, it is possible to perform high-precision formation by photolithography. For example, in Patent Document 1, a dry film of a photosensitive resin layer that becomes a liquid flow path is formed on a substrate having an inorganic material layer by a lamination method, and exposed to light in the shape of the flow path. Next, a dry film of a photosensitive resin layer that becomes a nozzle portion and an ejection port that connects the ejection port and the flow path is laminated on the photosensitive resin layer that becomes the flow path. Then, after exposure to the ejection port shape, the uncured portions of each photosensitive resin layer are removed all at once by development, and a method for manufacturing a liquid ejection head is described in which a flow path, a nozzle portion, and an ejection port are formed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-18272 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, as the demand for inkjet image recording becomes more sophisticated, the performance required for the ink also becomes more sophisticated, and in view of fixation to the recorded matter, a solvent with a high boiling point may be added to the ink. The ink obtained in this way may permeate the photosensitive resin layer made of epoxy resin or the like, and may deform the flow path forming member. Therefore, when such an ink type is used, in the configuration of the liquid ejection head described in Patent Document 1, the deformation of the flow path forming member progresses at a pace faster than that of the ink type used conventionally, and there is room for improvement in terms of long-term reliability. For example, when the inkjet recording head is used for a long period of time, the deformation of the flow path forming member may cause the external member to peel off from the substrate, or the desired ink ejection performance may not be obtained.

[0006] Therefore, an object of the present invention is to provide a liquid ejection head that can prevent ink from penetrating into a flow path forming member, thereby suppressing peeling of the flow path forming member from the substrate even when a highly permeable ink is used, and that has excellent pattern reproducibility and good print quality. [Means for solving the problem]

[0007] According to one embodiment of the present invention, In a liquid ejection head having an ejection port forming member and a flow path forming member on a substrate, the flow path forming member is a cured product of a photosensitive resin composition including a resin and a compound including a ligand having a lone pair of electrons, and is in contact with a substrate having an inorganic material layer on a surface thereof; The liquid ejection head is characterized in that the compound containing a ligand having a lone electron pair is contained in an amount of 1.0 mass % to 5.0 mass % relative to 100 mass % of the epoxy resin contained in the photosensitive resin composition.

[0008] According to one embodiment of the present invention, A method for manufacturing a liquid ejection head, comprising the steps of forming a flow path forming member by forming a first resin layer made of a photosensitive resin composition (1) on a substrate, exposing and developing the first resin layer, and forming an ejection port forming member by laminating a second resin layer made of a photosensitive resin composition (2) on the formed flow path forming member, and exposing and developing the second resin layer, The photosensitive resin composition (1) is a photosensitive resin composition comprising an epoxy resin, a polymerization initiator, and a compound containing a ligand having a lone electron pair, and the compound containing the ligand having a lone electron pair is contained in an amount of 1.0 mass % or more and less than 10.0 mass % relative to 100 mass % of the epoxy resin. Effect of the Invention

[0009] According to one embodiment of the present invention, by preventing the ink from penetrating into the flow path forming member, it is possible to suppress peeling of the flow path forming member from the substrate even when a highly permeable ink is used, and it is possible to provide a liquid ejection head with excellent pattern reproducibility and good print quality. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1A is a schematic perspective view showing the configuration of a liquid ejection head according to an embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view taken along line A1-A2 in FIG. 1A. [Diagram 2] 1 is a schematic cross-sectional view showing one embodiment of a method for producing a transfer body having a resin layer made of a photosensitive resin composition. [Diagram 3] 5A to 5C are schematic cross-sectional views illustrating a manufacturing method of a liquid ejection head according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A preferred embodiment of the present invention will be described below with reference to the drawings. In the following description, a liquid ejection head and a manufacturing method thereof according to the present invention will be described as an example, but the liquid ejection head and the manufacturing method thereof of the present invention are not limited to this. In the following description, components having the same functions are given the same numbers in the drawings, and their description may be omitted. In the present invention, the description of "XX or more and YY or less" or "XX to YY" expressing a numerical range means a numerical range including the lower and upper limits which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined.

[0012] (Liquid ejection head) Fig. 1(A) is a schematic perspective view showing a liquid ejection head according to an embodiment of the present invention, and Fig. 1(B) is a schematic cross-sectional view of the liquid ejection head according to the embodiment of the present invention, taken along a plane perpendicular to a substrate and passing through A1-A2 in Fig. 1(A).

[0013] The liquid ejection head shown in FIG. 1 has a substrate 1 on which energy generating elements 2 that generate energy for ejecting liquid are formed at a predetermined pitch. The substrate 1 is, for example, a silicon substrate made of silicon. The silicon substrate is preferably a single crystal of silicon, with a crystal orientation of the surface being (100). The energy generating elements 2 are, for example, electrothermal conversion elements and piezoelectric elements, and for example, tantalum silicon nitride (TaSiN) can be used as a resistance heating element for the electrothermal conversion element. The energy generating elements 2 may be provided so as to be in contact with the surface of the substrate 1, or may be provided partially hollow with respect to the surface of the substrate 1. A control signal input electrode (not shown) for operating the energy generating elements 2 is connected to the energy generating elements 2. In addition, a liquid supply port (hereinafter also referred to as a "supply port") 3 for supplying ink is opened in the substrate 1.

[0014] An inorganic material layer 4 and a protective layer 5 are formed on the front surface side of the substrate 1. The inorganic material layer 4 may be at least one metal film selected from Ta, Ir, W, Ti, Pt, Au, Pd, Cu, Al, and Si, or an inorganic film such as silicon oxide (SiO2), silicon nitride (SiN), silicon carbide (SiC), silicon carbonitride (SiCN), or silicon carbonate (SiOC). In FIG. 1, the inorganic material layer 4 is used as a heat storage layer, or an insulating layer if it is insulating. The protective layer 5 protects the energy generating element, and is made of, for example, Ta or Ir. The inorganic material layer 4 may cover the energy generating element.

[0015] In Fig. 1, the inorganic material layer 4 is formed on almost the entire surface of the substrate 1. On the inorganic material layer 4, a side wall of a flow path 7 is formed by a flow path forming member 6. Furthermore, on the flow path forming member 6 and the flow path 7, a discharge port forming member 10 having a discharge port 8 and a nozzle portion 9 is formed. Furthermore, a liquid repellent layer 11 is formed on the discharge port forming member 10 as necessary.

[0016] This liquid ejection head has a configuration in which liquid such as ink is supplied from a supply port 3 through a flow path 7, and by applying pressure generated by an energy generating element 2, the liquid is ejected as droplets (ink droplets) from an ejection port 8 via a nozzle portion 9.

[0017] (Method of manufacturing liquid ejection head) Next, a method for manufacturing the liquid ejection head of this embodiment will be described below with reference to FIGS. FIG. 2 is a schematic cross-sectional view according to one embodiment of a method for producing a transfer body (dry film) having a resin layer made of a photosensitive resin composition. FIG. 3 is a schematic cross-sectional view of a liquid ejection head according to one embodiment of the manufacturing method of the present invention, and is a view of the same cross section as FIG. 1(B) in a completed state.

[0018] First, as shown in Fig. 2(a), a film substrate 21 made of polyethylene terephthalate (PET), polyimide (PI), or the like is prepared. Next, as shown in Fig. 2(b), a photosensitive resin composition is applied to the film substrate 21 by a spin coating method, a slit coating method, or the like, and prebaked to form a resin layer 22 made of the photosensitive resin composition, thereby producing a transfer body 20.

[0019] When the photosensitive resin composition is transferred to a substrate having a liquid supply port formed thereon in advance, the photosensitive resin composition preferably has a weight average molecular weight of at least 5,000 or more. Furthermore, the photosensitive resin composition preferably contains an epoxy resin having two (bifunctional) functional groups such as epoxy groups or hydroxyl groups at the terminal, and further contains an epoxy resin having three (trifunctional) functional groups at the terminal. Furthermore, the photosensitive resin composition is preferably a negative type photosensitive epoxy resin composition further containing a polyhydric alcohol not containing a perfluoroalkyl group or a perfluoroalkylene group, a photoacid generator, and a solvent. The composition will be described later.

[0020] The process of manufacturing a liquid ejection head using such a transfer body will be described with reference to FIG. As shown in FIG. 3(a), a substrate 1 having energy generating elements 2 on its front surface is prepared.

[0021] 3(b), an inorganic material layer 4 is formed on the front surface side of the substrate 1 so as to cover the energy generating elements 2. In addition, a protective layer 5 is formed above the energy generating elements 2 so as to be in contact with the inorganic material layer 4. The inorganic material layer 4 and the protective layer 5 are patterned as necessary.

[0022] 3(c), a supply port 3 is formed through the substrate to supply ink. The supply port 3 is formed at a desired position by wet etching using an alkaline etching solution such as TMAH (tetramethylammonium hydroxide) or dry etching such as reactive ion etching.

[0023] As shown in FIG. 3(d), a first resin layer 13 is formed on the inorganic material layer 4 of the substrate 1 on which the energy generating element 2 and the supply port 3 are arranged by transferring the composition using a lamination method. The first resin layer 13 is formed by producing and using a transfer body made of the photosensitive resin composition (1) by the method shown in FIG. 2. The film may be formed by transferring the composition to the substrate while heating. In the case of a substrate on which the supply port 3 is not arranged, the photosensitive resin composition (1) may be applied by a spin coat method, a slit coat method, or the like to form a film, without using the composition as a transfer body. The photosensitive resin composition (1) is preferably a cationic polymerization type epoxy resin composition, taking into consideration the adhesion to the discharge port forming member 10 described later, mechanical strength, stability against liquids such as ink, resolution, and the like. The thickness of the first resin layer 13 corresponds to the height of the flow path, and is therefore determined appropriately depending on the ejection design of the liquid ejection head, but can be, for example, 3 μm to 45 μm.

[0024] As shown in FIG. 3(e), the first resin layer 13 is pattern-exposed through a flow path forming mask 14 having a flow path pattern. The exposed portion is then cured by heat treatment (Post Exposure Bake: PEB) to form a flow path forming member 6 made of a cured product of the photosensitive resin composition (1). The flow path forming mask 14 is a substrate made of a material such as glass or quartz that transmits light of an exposure wavelength, on which a light-shielding film such as a chrome film is formed in accordance with a pattern of a flow path, etc. As an exposure device, a single wavelength light source such as an i-line exposure stepper or a KrF stepper, or a projection exposure device having a broad wavelength light source of a mercury lamp such as a mask aligner MPA-600Super (product name, manufactured by Canon Inc.) can be used.

[0025] As shown in FIG. 3(f), a second resin layer 15 made of a photosensitive resin composition (2) is transferred onto the unexposed first resin layer 13 and the flow path forming member 6 by a lamination method to form a film. The second resin layer 15 is used by producing a transfer body by the method shown in FIG. 2, similar to the first resin layer 13. Furthermore, a liquid repellent layer 11 is formed on the second resin layer 15 as necessary. The second resin layer 15 is preferably formed of a cationic polymerization type epoxy resin composition, taking into consideration the adhesion to the flow path forming member 6, mechanical strength, stability against liquids such as ink, resolution, and the like. Furthermore, the thickness of the second resin layer 15 is appropriately determined according to the ejection design of the liquid ejection head, and is not particularly limited, but from the viewpoint of mechanical strength and the like, it can be, for example, 3 μm to 25 μm. The liquid-repellent layer 11 is required to have liquid repellency against liquids such as ink, and it is preferable to use a fluorine compound such as a cationic polymerizable perfluoroalkyl composition or perfluoropolyether composition as the liquid repellent. In general, it is known that the fluoroalkyl chains of perfluoroalkyl compositions and perfluoropolyether compositions are segregated at the interface between the composition and air by baking treatment after coating, and it is possible to increase the liquid repellency of the surface of the liquid-repellent layer.

[0026] As shown in FIG. 3(g), the second resin layer 15 and the liquid repellent layer 11 are pattern-exposed through a discharge port forming mask 16 having a discharge port pattern. Furthermore, the exposed portion is cured by heat treatment (PEB) to form a discharge port forming member 10. When exposing using exposure light containing light of the same wavelength as that of the first resin layer 13, the exposure amount for curing the second resin layer 15 is made smaller than the exposure amount for curing the first resin layer 13. In other words, when exposing the second resin layer 15, if the exposure amount of the light transmitted through the second resin layer 15 is such that the unexposed portion of the first resin layer 13 is cured, it becomes difficult to remove the first resin layer 13 in the unexposed portion in the development process, and the flow path 7 cannot be formed with high accuracy. For this reason, when exposing using exposure light containing light of the same wavelength, it is preferable that the photosensitive resin composition (2) has a relatively higher sensitivity than the photosensitive resin composition (1). The discharge port forming mask 16 is a substrate made of a material such as glass or quartz that transmits light of the exposure wavelength, on which a light-shielding film such as a chrome film is formed in accordance with the discharge port pattern. As the exposure device, a projection exposure device having a single wavelength light source such as an i-line exposure stepper or a KrF stepper, or a broad wavelength light source of a mercury lamp such as the mask aligner MPA-600Super (product name, manufactured by Canon) can be used.

[0027] As shown in FIG. 3(h), the unexposed (uncured) portions of the first resin layer 13, the second resin layer 15, and the liquid-repellent layer 11 are developed with a developer to remove them all at once, forming a flow path 7, a discharge port 8, and a nozzle portion 9. If necessary, a further heat treatment is performed to complete the liquid discharge head. Examples of the developer include PGMEA (propylene glycol monomethyl ether acetate), MIBK (methyl isobutyl ketone), and xylene. If necessary, a rinse treatment using IPA (isopropyl alcohol) or the like may be performed.

[0028] In the manufacturing method of the liquid ejection head of the present invention, after the step of pattern-exposing the first resin layer 13 to form the flow path forming member 6 in the above-mentioned manufacturing method, the second resin layer 15 is laminated on the flow path forming member 6 and the first resin layer 13. However, it is also possible to laminate the second resin layer 15 before exposing the first resin layer 13.

[0029] In the above-mentioned manufacturing method of the liquid ejection head of the present invention, the flow path forming member 6 and the ejection port forming member 10 are formed in two layers, but the present invention is not limited to this form. Furthermore, each member may be formed using a small number or a plurality of photosensitive resins. For example, a liquid ejection head may be produced by using the photosensitive resin composition (1) as an adhesive layer and using a different photosensitive resin composition for the flow path forming member and the ejection port forming member. Furthermore, the flow path forming member and the ejection port forming member may be formed using the photosensitive resin composition (1) of the present invention by using a mold material or the like. In the above explanation, the flow path forming member 6 is formed in contact with the inorganic material layer 4, but the present invention can be applied to any flow path forming member 6 on a substrate that is in contact with an inorganic material, i.e., a material containing metal atoms. For example, if the substrate is made of an inorganic material such as silicon (Si), when the flow path forming member 6 is formed directly on the substrate, it will be in contact with Si or SiO2, which is a natural oxide. It may also be in contact with a protective layer 5 made of Ta or Ir.

[0030] (Photosensitive resin composition) The photosensitive resin composition of the present invention will be described below. The photosensitive resin composition (1) and the photosensitive resin composition (2) constituting the flow path forming member and the discharge port forming member in the present invention are preferably formed of a cationic polymerization type epoxy resin composition. The reason is from the viewpoint of adhesion performance, mechanical strength, liquid (ink) resistance, swelling resistance, reactivity as a photolithography material, resolution, and the like of the cured product. More specifically, it is preferable that the photocationic polymerization type epoxy resin composition contains a polyfunctional epoxy resin having one or more of bisphenol A type and F type epoxy resins (bisphenol skeleton), phenol novolac type epoxy resins (phenol novolac skeleton), cresol novolac type epoxy resins (cresol novolac skeleton), norbornene skeleton, terpene skeleton, dicyclopentadiene skeleton, and oxycyclohexane skeleton, and the like. In addition, it is preferable to use a bifunctional or higher functional epoxy resin. By using a bifunctional or higher functional epoxy resin, the cured product is crosslinked three-dimensionally, which is suitable for obtaining desired properties.

[0031] In the case of a microstructure obtained by transferring the photosensitive resin composition (1) onto a substrate having an opening or a recess while applying heat, the photosensitive resin composition (1) disposed on the inorganic material layer 4 preferably has heat resistance to a thermal process from the viewpoint of stability of the pattern shape. For example, when the photosensitive resin composition (1) is used as a dry film and transferred onto a substrate having an opening or a recess while applying heat, or during other thermal processes such as post-exposure heat treatment (PEB), the layer preferably has a film strength such that the layer does not deform even in an uncured state. For this reason, the epoxy resin contained in the photosensitive resin composition (1) preferably has a high weight-average molecular weight, specifically, a weight-average molecular weight (Mw) of 5,000 to 100,000 and a softening point of 90°C or higher is preferable. If Mw is 5,000 or more, the film strength is improved, and the unexposed portion of the first resin layer 13 made of the photosensitive resin composition (1) can be prevented from falling significantly into the supply port 3, which is the opening of the substrate, during transfer or other thermal processes. If the unexposed first resin layer 13 drops significantly from the opening, the height of each resin layer becomes non-uniform. A similar drop may occur when the softening point is less than 90° C. On the other hand, if the weight average molecular weight (Mw) is 100,000 or less, the crosslink density of the photosensitive resin composition increases, and the stability of the pattern shape increases. Furthermore, from the viewpoint of reactivity, the photosensitive resin composition (1) preferably contains a bifunctional or higher epoxy resin having a weight average molecular weight of 5,000 or more, and a trifunctional or higher epoxy resin. By containing a trifunctional or higher epoxy resin, crosslinking progresses three-dimensionally, and the sensitivity as a photosensitive material can be improved. The trifunctional or higher epoxy resin preferably has an epoxy equivalent of less than 500. When the epoxy equivalent is less than 500, sufficient sensitivity can be obtained, and a decrease in pattern resolution and a decrease in mechanical strength and adhesion of the cured product can be suppressed. The Mw of these resins can be calculated in polystyrene equivalent using gel permeation chromatography (e.g., manufactured by Shimadzu Corporation).

[0032] By adding a compound containing a ligand having a lone pair of electrons, a ring structure is formed by coordinate bonds between the metal in the inorganic material layer and the compound, which is effective in improving adhesion with the inorganic material layer. For example, even if the fine structure comes into contact with ink and the ink penetrates into the fine structure, the interface with the inorganic material layer is not easily peeled off from the inorganic material layer because a strong bond is formed. In addition, the penetration of the ink into the interface between the fine structure and the inorganic material layer is also suppressed, which also suppresses peeling. On the other hand, since the compound containing a ligand having a lone pair of electrons deactivates the acid during cationic polymerization, there is a concern that adding too much of it may reduce patterning properties.

[0033] In addition, the photosensitive resin composition (1) contains a compound containing a ligand having a lone pair from the viewpoint of adhesion with the inorganic material layer 4 and the like. The ligand means a site that can be coordinated to a metal, and has an element such as an oxygen atom or a nitrogen atom having a lone pair that is not directly involved in a covalent bond. By adding a compound containing a ligand having a lone pair, a coordinate bond is formed with the metal in the inorganic material layer, which is effective in improving adhesion with the inorganic material layer. The compound containing a ligand having a lone pair forms a stable coordinate bond with the metal, and preferably forms any one of a 4-membered ring, a 5-membered ring, and a 6-membered ring structure, and more preferably forms a 5-membered ring structure or a 6-membered ring structure. Furthermore, the compound containing a ligand having a lone pair is preferably one containing a hydrocarbon chain having 2 or more carbon atoms, since it can further suppress the penetration of liquid.

[0034] Specific examples of compounds containing a ligand having a lone electron pair include compounds having an amino group, such as glycine and glycylglycine; compounds having a sulfo group, such as ethyl sulfone, propyl sulfone, and butyl sulfone; compounds that form a four-membered ring with a metal; compounds that form a five-membered ring with a metal, such as 2,2-bipyridine, 1,10-phenanthroline, alanine, serine, 9,11-phenanthrenequinone, dimethylglyoxime, L-phenylalanine, and L-histidine; and compounds that form a six-membered ring with a metal, such as salicylic aldehyde and 2-hydroxybenzoic acid.

[0035] In addition, the amount of the compound containing a ligand having a lone electron pair is preferably 1.0% by mass or more relative to the total mass of the epoxy resin contained in the photosensitive resin composition (relative to 100% by mass of the epoxy resin) in order to improve adhesion with the inorganic material layer. On the other hand, if the amount of the compound containing a ligand is too large, the curability of the photosensitive resin composition decreases, and the pattern shape of a fine pattern such as a flow path pattern tends to deteriorate, so the amount of the compound containing a ligand is preferably less than 10.0% by mass. In addition, it is more preferably 1.0% by mass to 5.0% by mass, and even more preferably 1.0% by mass to 3.0% by mass.

[0036] Commercially available epoxy resins that can be used for the photosensitive resin composition (1) that becomes the flow path forming member and the photosensitive resin composition (2) that becomes the discharge port forming member include "Celloxide 2021", "GT-300" series, "GT-400" series, "EHPE3150" (product names, all manufactured by Daicel Chemical Industries, Ltd.), "jER1031S", "jER1004", "jER1007", "jER1009", "jER1010", "jER1256", "157S70" (product names, all manufactured by Mitsubishi Chemical Corporation), "EPICLON N-695", "EPICLON N-865", "EPICLON 4050", "EPICLON 7050", "EPICLON HP-6000", "EPICLON HP-4710", "EPICLON HP-7200" series, "EPICLON Examples of such products include "EXA-4816" (product names, all manufactured by DIC Corporation), "EPOX-MKR1710" (product name, manufactured by Printec Co., Ltd.), "Denacol" series (product names, manufactured by Nagase ChemteX Corporation), and "EP-4000" series (product names, manufactured by ADEKA Corporation).

[0037] The photosensitive resin composition preferably contains a polymerization initiator. The polymerization initiator is preferably a photopolymerization initiator. The photopolymerization initiator added to the photosensitive resin composition is preferably a photoacid generator selected from sulfonic acid compounds, diazomethane compounds, sulfonium salt compounds, iodonium salt compounds, disulfone compounds, and the like. Commercially available products include "ADEKAOPTOMER (registered trademark) SP-170", "ADEKAOPTOMER (registered trademark) SP-172", "ADEKAOPTOMER (registered trademark) SP-150" (trade names, all manufactured by ADEKA Corporation), "BBI-103", "BBI-102" (trade names, all manufactured by Midori Kagaku Co., Ltd.), "IBPF", "IBCF", "TS-01", "TS-91" (trade names, all manufactured by Sanwa Chemical Co., Ltd.), "CPI (registered trademark)-210", "CPI (registered trademark)-300", "CPI (registered trademark)-410" (trade names, all manufactured by San-Apro Co., Ltd.), "Irgacure (registered trademark) 290" (trade name, manufactured by BASF Japan Co., Ltd.), etc. Two or more of these photoacid generators can also be mixed and used.

[0038] Furthermore, a silane coupling agent can be added to improve adhesion. Commercially available silane coupling agents include "Silquest A-187 (registered trademark)" (trade name, manufactured by Momentive Performance Materials, Inc.).

[0039] In addition, to improve pattern resolution and adjust sensitivity (exposure dose required for curing), sensitizers such as anthracene compounds, basic substances such as amines, and acid generators that generate weakly acidic (pKa=-1.5 to 3.0) toluenesulfonic acid can be added. Commercially available acid generators that generate toluenesulfonic acid include "TPS-1000" (trade name, manufactured by Midori Chemical Industry Co., Ltd.) and "WPAG-367" (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0040] In addition, as the photosensitive resin composition (2), the "SU-8" series, "KMPR (registered trademark) 1000" (product names, all manufactured by Nippon Kayaku Co., Ltd.), "TMMR S2000", "TMMF S2000" (product names, all manufactured by Tokyo Ohka Kogyo Co., Ltd.), and the like, which are commercially available as negative dry film photoresists, can also be used. EXAMPLES

[0041] The present invention will be described in more detail below by showing examples, but the present invention is not limited to these examples. [Examples 1 to 5] For each example, a liquid ejection head was produced using the photosensitive resin composition (1) shown in Table 1, according to the process shown in Fig. 3. In each table, the composition is expressed in parts by mass.

[0042] [Table 1]

[0043] In the table, N695: Product name "EPICLON (registered trademark) N695", manufactured by DIC Corporation 1009F: Product name "jER (registered trademark) 1009F", manufactured by Mitsubishi Chemical Corporation 410S: San-Apro Co., Ltd., product name "CPI (registered trademark)-410S" SP-172: Product name "ADEKA Optomer (registered trademark) SP-172" manufactured by ADEKA Corporation TPS-1000: Midori Chemical Co., Ltd. A-187: Product name "Silquest A-187 (registered trademark)", manufactured by Momentive Performance Materials, Inc. ·PGMEA: Propylene glycol monomethyl ether acetate

[0044] First, as shown in FIG. 2(a), a PET film having a thickness of 100 μm was prepared as a film substrate 21. 2(b), a photosensitive resin composition (1) having the composition shown in Table 1 was applied onto the PET film by spin coating. Then, the film was baked at 90° C. for 10 minutes to volatilize the PGMEA solvent, and a first resin layer 13 having a thickness of 15.0 μm was formed as a resin layer 22 to prepare a dry film.

[0045] Next, as shown in FIG. 3(a), a substrate 1 made of silicon having energy generating elements 2 made of tantalum silicon nitride (TaSiN) on its front surface side was prepared. 3(b), an inorganic material layer 4 and a protective layer 5 made of Ta were formed to a thickness of 100 nm by sputtering on the front surface of the substrate 1 so as to cover the energy generating elements 2. Furthermore, the inorganic material layer 4 and the protective layer 5 were patterned by a photolithography process and reactive ion etching. Next, supply port 3 was formed as shown in FIG. 3(c). Supply port 3 was formed by forming an etching mask having an opening using a positive photosensitive resin made of OFPR (manufactured by Tokyo Ohka Kogyo Co., Ltd.) and performing reactive ion etching through the opening of the etching mask. The reactive ion etching was performed by the Bosch process using an ICP etching device (manufactured by Alcatel, model number: 8E). After the supply port 3 was formed, the etching mask was removed using a stripping solution.

[0046] Next, as shown in Fig. 3(d), a first resin layer 13 made of a photosensitive resin composition (1) shown in Table 1 was formed. Specifically, the dry film provided with the first resin layer 13 prepared above was heated to 70°C and pressed onto the substrate 1 on which the energy generating element 2 and the supply port 3 were arranged, and the first resin layer 13 was transferred. Thereafter, the PET film was peeled off from the first resin layer 13 with a peeling tape (not shown).

[0047] Next, as shown in FIG. 3( e ), a flow path forming mask 14 having a flow path pattern is used to perform an exposure of 16,000 J / m using an i-line exposure stepper (Canon, product name: i5). 2The first resin layer 13 was subjected to pattern exposure with an exposure amount of 1000 nm to 1000 nm. The exposed portion was then cured by heat treatment at 50° C. for 5 minutes to form a flow path forming member 6.

[0048] Next, as shown in FIG. 4(h), a second resin layer 15 made of a photosensitive resin composition (2) was laminated. First, in the same manner as the dry film having the first resin layer, the photosensitive resin composition (2) described in Table 2 was applied onto a 100 μm thick PET film, baked at 90° C. for 5 minutes to volatilize the solvent, and a 5.0 μm thick second resin layer 15 was formed to form a dry film. Next, the second resin layer 15 of the dry film was transferred and laminated onto the flow path forming member 6 of the unexposed and exposed parts of the first resin layer 13 by applying heat of 50° C. using a lamination method.

[0049] [Table 2]

[0050] In the table, 157S70: Product name "jER (registered trademark) 157S70", manufactured by Mitsubishi Chemical Corporation

[0051] As shown in FIG. 3(g), the second resin layer 15 is exposed to light at 1100 J / m using an i-line exposure stepper (manufactured by Canon, product name: i5) through a discharge port forming mask 16 having a discharge port pattern. 2 Then, the exposed portion was cured by performing a heat treatment at 90° C. for 5 minutes to form a discharge port forming member 10.

[0052] As shown in FIG. 3(h), the uncured portions of the first resin layer 13 and the second resin layer 15 were removed all at once by developing with PGMEA for 1 hour, and a flow path 7, an ejection port 8, and a nozzle portion 9 were formed, followed by curing with heat at 200° C. to obtain a liquid ejection head.

[0053] [Comparative Examples 1 to 3] In Comparative Examples 1 to 3, the photosensitive resin composition (1) having the composition shown in Table 1 was used to prepare a liquid ejection head in the same manner as in the Example.

[0054] [evaluation] <Pattern shape> In the liquid ejection heads produced in Examples 1 to 5 and Comparative Examples 1 to 3, after the development process of each liquid ejection head, the flow path width of the flow path forming member 6 in contact with the inorganic material layer 4 was measured using a white light interference microscope (manufactured by Hitachi High-Tech Science Corporation). Then, the pattern shape was judged according to the criteria shown in Table 3 from the ratio of the flow path width to the mask value (15 μm). The evaluation results of the pattern shape are shown in Table 1. The liquid ejection heads produced in Examples 1 to 5 had good pattern reproducibility. On the other hand, in Comparative Example 2, a large amount of a compound containing a ligand was added to the photosensitive epoxy resin composition, which reduced the curing property of the flow path forming member, causing the flow path width to deviate from the mask value, and thus reducing the pattern reproducibility.

[0055] [Table 3]

[0056] <Peeling test (ink resistance)> Ink having the components shown in Table 4 below was filled into the flow paths of each of the liquid ejection heads produced in Examples 1 to 5 and Comparative Examples 1 to 3, and the ink was left in an oven at 80° C. for 90 days.

[0057] [Table 4]

[0058] After being left at 80° C. for 90 days, the bonding state between the inorganic material layer and the flow passage forming member was observed with a metallurgical microscope and evaluated according to the following criteria. Evaluation criteria ◯: No peeling occurred between the inorganic material layer and the flow path forming member. ×: Peeling occurred between the inorganic material layer and the flow path forming member.

[0059] The results of the peeling test (ink resistance) are shown in Table 1. In the liquid ejection heads produced in Examples 1 to 5, no peeling was observed between the inorganic material layer and the flow path forming member, and the ink resistance was good. In Comparative Examples 1 and 3, since almost no compound containing a ligand was added, the adhesion between the inorganic material layer and the flow path forming member decreased, and peeling that was not observed when the liquid ejection head was completed was observed between the inorganic material layer and the flow path forming member.

[0060] <Printing evaluation> Each liquid ejection head produced in the examples and comparative examples was filled with the same ink as that used in the peeling test (ink resistance), and after leaving it at 70°C for 90 days, printing was performed to evaluate the printing. The liquid ejection heads produced in Examples 1 to 5 had good print evaluations, whereas in Comparative Examples 1 to 3, a decrease in pattern reproducibility and partial peeling between the inorganic material layer and the flow path forming member caused a decrease in print quality.

[0061] As described above, according to the present invention, even if an ink having high permeability into a flow path forming member is used, it is possible to prevent the ink from permeating into the flow path forming member, thereby suppressing peeling of the flow path forming member from the substrate. Furthermore, it is possible to provide a liquid ejection head having excellent pattern reproducibility and good print quality.

[0062] The present disclosure includes the following configurations. [Configuration 1] In a liquid ejection head having an ejection port forming member and a flow path forming member on a substrate, the flow path forming member is a cured product of a photosensitive resin composition including a resin and a compound including a ligand having a lone pair of electrons, and is in contact with a substrate having an inorganic material layer on a surface thereof; A liquid ejection head, characterized in that the compound containing a ligand having a lone electron pair is contained in an amount of 1.0 mass % to 5.0 mass % relative to 100 mass % of the epoxy resin contained in the photosensitive resin composition. [Configuration 2] A liquid ejection head according to [Configuration 1] or [Configuration 2], wherein the compound containing a ligand having a lone pair of electrons is coordinate-bonded with a metal in the inorganic material layer to form a structure of either a four-membered ring, a five-membered ring, or a six-membered ring. [Configuration 3] The liquid ejection head according to [Configuration 1] or [Configuration 2], wherein the compound containing a ligand having a lone pair has a hydrocarbon chain having two or more carbon atoms. [Configuration 4] The liquid ejection head according to any one of [Configuration 1] to [Configuration 3], wherein the resin is an epoxy resin having at least one of a bisphenol skeleton, a phenol novolac skeleton, a cresol novolac skeleton, a norbornene skeleton, a terpene skeleton, a dicyclopentadiene skeleton, and an oxycyclohexane skeleton. [Configuration 5] The liquid ejection head according to [Configuration 4], wherein the epoxy resin contains a di- or higher functional epoxy resin. [Configuration 6] The liquid ejection head according to [Configuration 4] or [Configuration 5], wherein the epoxy resin contains a di- or higher functional epoxy resin and a tri- or higher functional epoxy resin. [Configuration 7] The liquid ejection head according to any one of [Configuration 1] to [Configuration 6], wherein the photosensitive resin composition contains a polymerization initiator. [Configuration 8] The liquid ejection head according to [Configuration 7], wherein the polymerization initiator is a photoacid generator. [Configuration 9] A liquid ejection head described in [Configuration 1], wherein the inorganic material is at least one metal selected from Ta, Ir, W, Ti, Pt, Au, Pd, Cu, Al, and Si, or at least one selected from the group consisting of silicon oxide (SiO2), silicon nitride (SiN), silicon carbide (SiC), silicon carbonitride (SiCN), and silicon carbonate (SiOC).

[0063] The present disclosure includes the following methods. [Method 1] A method for manufacturing a liquid ejection head, comprising the steps of forming a flow path forming member by forming a first resin layer made of a photosensitive resin composition (1) on a substrate, exposing and developing the first resin layer, and forming an ejection port forming member by laminating a second resin layer made of a photosensitive resin composition (2) on the formed flow path forming member, and exposing and developing the second resin layer, The method for producing a liquid ejection head, wherein the photosensitive resin composition (1) is a photosensitive resin composition comprising an epoxy resin, a polymerization initiator, and a compound containing a ligand having a lone electron pair, and the compound containing the ligand having a lone electron pair is contained in an amount of 1.0 mass % or more and less than 10.0 mass % relative to 100 mass % of the epoxy resin. [Explanation of symbols]

[0064] 1 Board 2 Energy generating element 3 Supply inlet 4 Inorganic material layer 5 Protective layer 6 Flow path forming member 7 Flow Path 8 outlet 9 Nozzle section 10. Discharge port forming member 11 Liquid repellent layer 12 Film 13 First resin layer 14 Flow path forming mask 15 Second resin layer 16. Discharge port forming mask

Claims

1. In a liquid ejection head having an ejection port forming member and a flow path forming member on a substrate, the flow path forming member is a cured product of a photosensitive resin composition including a resin and a compound including a ligand having a lone pair of electrons, and is in contact with a substrate having an inorganic material layer on a surface thereof; A liquid ejection head, comprising: a compound containing a ligand having a lone electron pair, the compound being contained in an amount of 1.0% by mass to 5.0% by mass relative to 100% by mass of an epoxy resin contained in the photosensitive resin composition.

2. The liquid ejection head according to claim 1 , wherein the compound containing a ligand having a lone pair forms a coordinate bond with a metal in the inorganic material layer to form any one of a four-membered ring, a five-membered ring, and a six-membered ring structure.

3. The liquid ejection head according to claim 1 , wherein the compound containing a ligand having a lone pair of electrons has a hydrocarbon chain having two or more carbon atoms.

4. 3. The liquid ejection head according to claim 1, wherein the resin is an epoxy resin having at least one of a bisphenol skeleton, a phenol novolac skeleton, a cresol novolac skeleton, a norbornene skeleton, a terpene skeleton, a dicyclopentadiene skeleton, and an oxycyclohexane skeleton.

5. The liquid ejection head according to claim 4 , wherein the epoxy resin contains a di- or higher-functional epoxy resin.

6. 5. The liquid ejection head according to claim 4, wherein the epoxy resin contains a di- or higher functional epoxy resin and a tri- or higher functional epoxy resin.

7. The liquid ejection head according to claim 1 , wherein the photosensitive resin composition contains a polymerization initiator.

8. The liquid ejection head according to claim 7 , wherein the polymerization initiator is a photoacid generator.

9. The inorganic material is at least one metal selected from Ta, Ir, W, Ti, Pt, Au, Pd, Cu, Al, and Si, or silicon oxide (SiO ２ 2. The liquid ejection head according to claim 1, wherein the material is at least one selected from the group consisting of silicon nitride (SiN), silicon carbide (SiC), silicon carbonitride (SiCN), and silicon carbonate (SiOC).

10. A method for manufacturing a liquid ejection head, comprising the steps of forming a flow path forming member by forming a first resin layer made of a photosensitive resin composition (1) on a substrate, exposing and developing the first resin layer, and forming an ejection port forming member by laminating a second resin layer made of a photosensitive resin composition (2) on the formed flow path forming member, and exposing and developing the second resin layer, The photosensitive resin composition (1) is a photosensitive resin composition comprising an epoxy resin, a polymerization initiator, and a compound containing a ligand having a lone electron pair, and the compound containing a ligand having a lone electron pair is contained in an amount of 1.0 mass% or more and less than 10.0 mass% relative to 100 mass% of the epoxy resin.

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