Liquid discharge head and manufacturing method of liquid discharge head

Abstract

To provide a liquid discharge head having a cured material of an adhesive agent which has low elasticity, a favorable temporary fixing property, bleed resistance and resistance to many types of ink.SOLUTION: A liquid discharge head is constituted by a plurality of members, and at least one between the members is adhered by a cured material of an adhesive agent. The adhesive agent is a resin composition at least including (A) epoxy resin, (B) liquid aromatic amine curing agent, (C) liquid acid anhydride curing agent, and (D) catalyst. In the resin composition, the equivalent ratio of (A) epoxy resin and the total sum of (B) liquid aromatic amine curing agent and (C) liquid acid anhydride curing agent is A:(B+C)=1:1-2:3. The equivalent in the equivalent ratio is defined by equivalent=molecular mass / (number of functional groups×mass of chemical compound), and (A) epoxy resin contains (A-1) bisphenol A-type epoxy resin and (A-2) hydrogenation bisphenol A-type epoxy resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection head for ejecting liquid such as ink from ejection ports, and a method for manufacturing the liquid ejection head. [Background technology]

[0002] 2. Description of the Related Art A recording method using a liquid ejection head, such as an inkjet recording head, involves applying thermal energy or vibration energy to a liquid such as ink, ejecting the ink as minute droplets from an ejection port, and forming an image on a recording medium.

[0003] The manufacturing method for this type of liquid ejection head involves first providing ejection energy generating elements and wiring conductors for supplying power to the ejection energy generating elements on a silicon substrate. Then, after providing a protective film on the wiring conductors, ink flow paths and ink ejection ports are patterned using resist. Next, through-holes (ink supply ports) for supplying ink from the back side of the silicon substrate to the ejection energy generating element section are drilled in the silicon substrate to form a recording element substrate. A support plate made of alumina, resin, or the like is then attached to the recording element substrate with an adhesive, electrically connecting the recording element substrate to the electrical wiring member.

[0004] Furthermore, from the perspective of manufacturing cost, adhesives and sealants used in the final process for bonding and sealing other components are fully cured together. In other words, the adhesive has not yet hardened during the process of bonding the support plate and the recording element substrate. Therefore, the accuracy of the recording element substrate, which is positioned during bonding, may be reduced when the substrate is moved to the next process. For the reasons mentioned above, to prevent misalignment of the recording element substrate, it is desirable to temporarily cure the adhesive (temporarily fix) within the substrate bonding device. Examples of adhesives and sealants used in addition to those used for bonding the recording element substrate and the support plate include chip perimeter sealants and ILB (inner lead bonding) sealants.

[0005] The adhesive used to attach the recording element substrate (silicon chip) and the support plate (chip plate) must have high adhesiveness and ink resistance. Furthermore, one-component thermosetting epoxy resin compositions are often used because they are easy to use in the manufacturing process. Because one-component epoxy resins require storage stability, powder curing agents are often used. However, bleeding is often an issue when using adhesives that use epoxy resins that are liquid at room temperature and powder curing agents. This occurs when the adhesive applied to a chip plate is thinly crushed with a silicon chip and then cured, causing the epoxy resin to bleed out and leaving uncured components. If the remaining uncured components come into contact with ink, they may adhere to the ink ejection surface or reduce ink ejection accuracy. Therefore, adhesives used in the flow paths of inkjet recording heads must be able to suppress bleeding. For example, Patent Document 1 discloses an adhesive that can be used in printer heads. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-302591 Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 does not use a powdered curing agent, so it is thought that bleeding is less likely to occur. Patent Document 1 uses an amide-based amine curing agent as the curing agent, and the cured product of the adhesive has an amide bond. The presence of an amide bond reduces the elastic modulus of the cured epoxy resin. However, the present inventors have recognized that the presence of amide bonds can cause problems with resistance to organic inks. The present disclosure provides a liquid ejection head having a cured product of an adhesive that has low elasticity, good temporary fixing properties, bleeding resistance, and resistance to many types of ink, and a method for manufacturing the liquid ejection head. [Means for solving the problem]

[0008] The present disclosure provides a liquid ejection head made up of multiple members, At least one of the members is bonded with a cured adhesive, The adhesive comprises at least (A) epoxy resin, (B) a liquid aromatic amine curing agent; (C) a liquid acid anhydride curing agent, and (D) catalyst; A resin composition comprising: In the resin composition, the equivalent ratio of the (A) epoxy resin to the sum of the (B) liquid aromatic amine curing agent and the (C) liquid acid anhydride curing agent is A:(B+C)=1:1 to 2:3; The equivalent weight in the ratio of the amount of equivalents is defined as equivalent weight = molecular weight / (number of functional groups x mass of compound), The liquid ejection head relates to the (A) epoxy resin, which contains (A-1) a bisphenol A type epoxy resin and (A-2) a hydrogenated bisphenol A type epoxy resin.

[0009] The present disclosure provides a method for manufacturing the liquid ejection head, The manufacturing method includes a step of bonding at least one of the members with the adhesive. The present invention relates to a method for manufacturing a liquid ejection head. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a liquid ejection head having a cured adhesive that has low elasticity, good temporary fixing properties, bleeding resistance, and resistance to many types of ink, and a method for manufacturing a liquid ejection head. [Brief explanation of the drawings]

[0011] [Figure 1] Schematic diagram for explaining an example of an inkjet DETAILED DESCRIPTION OF THE INVENTION

[0012] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the upper and lower 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 combined arbitrarily. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean 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] Hereinafter, embodiments of the present disclosure will be described. <Liquid ejection head> The configuration of an inkjet head as a liquid ejection head according to the present disclosure will be described with reference to the drawings. Fig. 1A is a perspective view of one embodiment of an inkjet head 1. Fig. 1B is an example of a cross-sectional view of the inkjet head cut in a direction perpendicular to the ejection port surface (the surface of the ejection port member having the ejection ports).

[0014] 1A and 1B, an inkjet head 1, which is a liquid ejection head, is composed of multiple members. The inkjet head 1 includes at least a recording element substrate 2, a supply flow path 3, a support member 4, and a flow path member 5. The supply flow path 3 is a flow path for supplying a liquid such as ink to the recording element substrate 2, and is connected to the recording element substrate 2 from the flow path member 5. The flow path member 5 is a member that forms the supply flow path 3. The support member 4 is provided between the recording element substrate 2 and the flow path member 5, and is a member that fixes the recording element substrate 2 to the flow path member 5.

[0015] In the present disclosure, adhesives can be used to bond these members together, and examples of the materials for these members include at least one selected from the group consisting of silicon, silicon nitride, silicon carbide, aluminum, alumina, SUS, titanium, zirconium, tantalum, PPE, and POM.

[0016] At least one of the components constituting a liquid ejection head is bonded with a cured adhesive. Because the manufacturing process for a liquid ejection head requires precise bonding between two components, such as flow path members, the head may be assembled using the following procedure: An adhesive is applied to the support member 4, and the recording element substrate 2 is temporarily attached in a short time, after which the adhesive is fully cured. The third flow path member 8 and the second flow path member 7 are bonded together, and the second flow path member 7 is then bonded to the first flow path member 6 to create the flow path member 5. Next, the support member 4 and the first flow path member 6 in the flow path member 5 are temporarily bonded together. Finally, the adhesive is fully cured.

[0017] The liquid ejection head preferably has a cured adhesive at a position where the cured adhesive can come into contact with a liquid such as ink. The liquid ejection head preferably has a cured adhesive at least between the recording element substrate 2 and the support member 4, between the support member 4 and the flow path member 5, and between the members that form the flow path member 5 (between the first flow path member 6 and the second flow path member 7, and between the second flow path member 7 and the third flow path member 8).

[0018] The method for manufacturing a liquid ejection head preferably includes a step of bonding at least one of a plurality of members with a resin composition. The method for manufacturing a liquid ejection head preferably includes a step of applying an adhesive to a support member 4, temporarily attaching the recording element substrate 2, and curing the adhesive. The method for manufacturing a liquid ejection head preferably includes a step of temporarily attaching the support member 4, to which the recording element substrate 2 is adhered, and the flow path member 5, and curing the adhesive.

[0019] Furthermore, it is preferable to thin the adhesive film thickness to improve dimensional accuracy after bonding between components. In particular, when bonding between support members or flow path members, the bonding area is large and precision deviations are likely to be large. Therefore, in order to maintain a constant adhesive film thickness, it is preferable to press the components together firmly to thin the adhesive. Bleeding can be a problem at this time, but the adhesive disclosed herein uses a liquid curing agent, so bleeding is less likely to occur. Therefore, it is suitable for bonding between components.

[0020] Furthermore, when bonding dissimilar materials, differences in the coefficient of linear expansion can cause thermal stress, but the adhesive according to the present disclosure has low elasticity and relieves stress, making it suitable for use even when the components are made of dissimilar materials.The storage modulus of the cured adhesive at 25°C and 1.0 Hz is preferably 0.01 to 1.5 GPa, and more preferably 0.1 to 1.0 GPa. The storage modulus can be controlled by the resin composition of the epoxy resin, liquid aromatic amine curing agent, liquid acid anhydride curing agent, and catalyst.

[0021] <Resin composition of adhesive> The adhesive used in the liquid ejection head will be described. (A) epoxy resin, (B) a liquid aromatic amine curing agent; (C) a liquid acid anhydride curing agent, and (D) catalyst; The resin composition includes: Furthermore, the (A) epoxy resin contains at least (A-1) a bisphenol A type epoxy resin and (A-2) a hydrogenated bisphenol A type epoxy resin.

[0022] The use of a liquid curing agent improves bleeding resistance. Furthermore, as a result of extensive research, the inventors have come up with the idea of ​​an adhesive that combines resistance to organic inks and suppresses bleeding, by generating an amide bond not only through a reaction between the epoxy and the curing agent during heat curing, but also through a reaction between the amine curing agent and the acid anhydride curing agent, and that also has good temporary bonding properties.

[0023] The formation of amide bonds reduces elasticity, which can alleviate thermal stress caused by differences in linear expansion when the adherend is made of dissimilar materials. However, the present inventors conducted research and discovered that the presence of consecutive amide bonds within a molecule can cause problems with ink resistance. Therefore, the present inventors discovered that ink resistance can be improved by randomly generating amide bonds during heat curing. It is believed that the presence of a reaction product between an epoxy resin and a liquid aromatic amine curing agent, which has better ink resistance than an amide bond, and a reaction product between an epoxy resin and a liquid acid anhydride curing agent near the amide bond results in overall excellent ink resistance.

[0024] Specifically, the equivalent ratio (A:(B+C)) of the (A) epoxy resin to the (B) liquid aromatic amine curing agent and the (C) liquid acid anhydride curing agent in the resin composition satisfies A:(B+C) = 1:1 to 2:3. With this ratio, the following three reactions occur, which are thought to result in a random state. Reaction of (A) epoxy resin with (B) liquid aromatic amine curing agent, (A) the reaction of an epoxy resin with (C) a liquid acid anhydride curing agent; and Reaction of (B) a liquid aromatic amine curing agent and (C) a liquid acid anhydride curing agent with (A) an epoxy resin

[0025] In the resin composition, the equivalent ratio (A:(B+C)) of (A) epoxy resin to the sum of (B) liquid aromatic amine curing agent and (C) liquid acid anhydride curing agent satisfies A:(B+C) = 1:1 to 2:3. By satisfying this equivalent ratio, not only bleed resistance but also ink resistance and temporary adhesion are improved, and a cured adhesive with low elasticity can be obtained. The inventors speculate that the reason for this is as follows: If the ratio of the base agent is higher than this equivalent ratio, the base agent will remain during the reaction, and if the ratio of the curing agent is higher, the curing agent will remain during the reaction. If unreacted components remain, the ink resistance and temporary adhesion will also be reduced.

[0026] When the amine of the curing agent reacts with the acid anhydride, the equivalent ratio of the base resin to the curing agent is shifted, resulting in poor curing. Therefore, it is preferable that the equivalent ratio of the curing agent to the epoxy resin is higher. In this disclosure, equivalent weight is defined as equivalent weight = molecular weight / (number of functional groups × mass of compound). The functional group is a functional group involved in the three reactions described above. In the case of (A) epoxy resin, the functional group is an epoxy group, in the case of (B) liquid aromatic amine curing agent, the functional group is an amino group, and in the case of (C) liquid acid anhydride curing agent, the functional group is an acid anhydride group.

[0027] Furthermore, from the viewpoint of adhesiveness, the equivalent ratio (B:C) of the liquid aromatic amine curing agent (B) to the liquid acid anhydride curing agent (C) in the resin composition is preferably 1:1 to 4:1.

[0028] The liquid acid anhydride curing agent (C) is not particularly limited, and any known agent may be used. From the viewpoints of storage stability and ink resistance, the liquid acid anhydride curing agent (C) preferably contains an alicyclic acid anhydride.

[0029] The epoxy resin (A) contains at least (A-1) a bisphenol A epoxy resin and (A-2) a hydrogenated bisphenol A epoxy resin. The ink resistance and elastic modulus may be insufficient if the bisphenol A epoxy resin (A-1) is used alone. Furthermore, the ink resistance may be insufficient if the hydrogenated bisphenol A epoxy resin (A-2) is used alone. The hydrogenated portions of these hydrogenated bisphenol A epoxy resins have lower planarity than the bisphenol A epoxy resins, which is thought to make it difficult for ink to penetrate into the resin due to steric hindrance. Therefore, by including both a bisphenol A epoxy resin and a hydrogenated bisphenol A epoxy resin, both ink resistance and low elasticity can be achieved. Bisphenol A type epoxy resins are produced, for example, by condensation of bisphenol A and epichlorohydrin.

[0030] The epoxy resin (A) preferably contains 10 to 80% by mass (more preferably 60 to 80% by mass) of bisphenol A epoxy resin (A-1) and 10 to 50% by mass (more preferably 20 to 40% by mass) of hydrogenated bisphenol A epoxy resin (A-2). By satisfying the above contents, the crosslink density increases and ink resistance is further improved.

[0031] The adhesive resin composition preferably further contains an aliphatic amine curing agent (E). Since inkjet heads require dimensional accuracy, the resin composition containing an aliphatic amine curing agent improves temporary bonding properties. The content of the aliphatic amine curing agent is preferably 2 to 30 parts by mass, more preferably 5 to 15 parts by mass, per 100 parts by mass of the epoxy resin (A).

[0032] The resin composition can be produced by any known method without any particular limitations. For example, (A) an epoxy resin and (D) a catalyst are mixed and kneaded using a stirrer / defoamer. Then, (B) a liquid aromatic amine curing agent and (C) a curing agent containing a liquid acid anhydride curing agent are added, and the mixture is kneaded using a stirrer / defoamer to obtain a resin composition. The resin composition may contain known additives, etc., as needed.

[0033] From the viewpoint of dripping and adhesive thickness when applying the resin composition, -1 The viscosity of the resin composition measured by the method is preferably 500 to 100,000 mPa·s. The viscosity is measured using a viscometer (TVE-35H (Toki Sangyo)). Specifically, a predetermined amount is measured into the viscometer cup, a predetermined gap is left between the cup and the rotor, and the rotor is rotated to read the viscosity value.

[0034] In addition to the (A-1) bisphenol A epoxy resin and the (A-2) hydrogenated bisphenol A epoxy resin, the (A) epoxy resin may contain other epoxy resins, such as alicyclic epoxy resins, aromatic epoxy resins, and aliphatic epoxy resins, which are liquid at room temperature.

[0035] Examples of alicyclic epoxy resins include the following: Examples include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring, or compounds having a cyclohexene oxide structure or a cyclopentene oxide structure obtained by epoxidizing a compound having a cyclohexene or cyclopentene ring with an oxidizing agent, or compounds having a vinylcyclohexane oxide structure obtained by epoxidizing a compound having a vinylcyclohexane structure with an oxidizing agent. For example, hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylcyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxy cyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-metadioxane, bis(3,4-epoxycyclohexylmethyl)adipate, vinylcyclohexene dioxide, 4-vinyl ether epoxycyclohexane, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexylcarboxylate, methylene bis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di(3,4-epoxycyclohexylmethyl) ether, ethylene bis(3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, and the like.

[0036] Specific examples of aromatic epoxy resins include the following: Polyglycidyl ethers of polyhydric phenols having at least one aromatic ring or their alkylene oxide adducts, or those containing a naphthalene ring, such as glycidyl ethers of bisphenol A, bisphenol F, or compounds obtained by further adding alkylene oxide to these, epoxy novolac resins, bisphenol A novolac diglycidyl ether, bisphenol F novolac diglycidyl ether, etc.

[0037] Specific examples of aliphatic epoxy resins include the following: Examples include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof, polyglycidyl esters of aliphatic long-chain polybasic acids, epoxy-containing compounds obtained by oxidizing aliphatic long-chain unsaturated hydrocarbons with an oxidizing agent, homopolymers of glycidyl acrylate or glycidyl methacrylate, and copolymers of glycidyl acrylate or glycidyl methacrylate. Representative compounds include glycidyl ethers of polyhydric alcohols such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ether of polyethylene glycol, and diglycidyl ether of polypropylene glycol; polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene glycol and glycerin; and diglycidyl esters of aliphatic long-chain dibasic acids.

[0038] Further examples include monoglycidyl ethers of aliphatic higher alcohols, phenol, cresol, butylphenol, and monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these, glycidyl esters of higher fatty acids, epoxidized soybean oil, octyl epoxy stearate, butyl epoxy stearate, and epoxidized linseed oil.

[0039] Furthermore, from the viewpoints of flexibility and ink resistance, a good heat-cured product can be obtained if the epoxy resin contains 10 to 80 mass% of (A-1) bisphenol A epoxy resin and 10 to 50 mass% of (A-2) hydrogenated bisphenol A epoxy resin. Furthermore, the epoxy resin preferably contains 50 to 80 mass% of (A-1) bisphenol A epoxy resin and 10 to 30 mass% of (A-2) hydrogenated bisphenol A epoxy resin. Within these ranges, a better heat-cured product can be obtained.

[0040] Specific examples of the liquid acid anhydride curing agent (C) include the following: Specific examples of acid anhydride curing agents include: dodecenyl succinic anhydride (DDSA), poly(ethyloctadecanedioic) anhydride (SB-20AH), poly(phenylhexadecanedioic) anhydride (ST-2PAH), alicyclic acid anhydrides such as methyltetrahydrophthalic anhydride (Me-THPA), methylhexahydrophthalic anhydride (Me-HHPA), methylhimic anhydride (MHAC), hexahydrophthalic anhydride (HHPA), tetrahydrophthalic anhydride (THPA), trialkyltetrahydrophthalic anhydride (TATHPA), (2-propenyl)butanedioic anhydride, and aliphatic acid anhydrides such as methylcyclohexenecarboxylic acid (MCTC).

[0041] (B) Liquid aromatic amine curing agents include amine curing agents containing an aromatic ring. Specific examples include the following: aromatic ring-containing aliphatic polyamines such as xylylenediamine; 3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, 4,4'-diaminodiphenylmethane, 2,4-tolylenediamine, 2,6-tolylenediamine, 1,1'-dichloro-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 1,1',2,2'-tetrachloro-4,4'-diaminodiphenylmethane, 1, Aromatic amines such as 3,5-triethyl-2,6-diaminobenzene, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenyl-methane, N,N'-bis(t-butyl)-4,4'-diaminodiphenyl-methane, di(methylthio)toluenediamine, diethyltoluenediamine, dimethylthiotoluenediamine, 4,4'-methylenebis[N-(1-methylpropyl)aniline], aniline, o-toluidine, m-toluidine, and p-toluidine.

[0042] Dimethylthiotoluenediamine is preferred. Liquid amine-based curing agents other than aromatic amine curing agents may be used to the extent that the effects of the present disclosure are not impaired. Examples of other liquid amine-based curing agents include the following. As described above, it is preferable that the resin composition further contains an aliphatic amine curing agent (E) such as the following aliphatic polyamine. Aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, and polyoxyalkylenepolyamines; alicyclic polyamines such as isophoronediamine, norbornenediamine, and hydrogenated xylylenediamine;

[0043] The catalyst (D) is not particularly limited, and any known catalyst may be used. For example, an imidazole catalyst is preferred, such as 1-benzyl-2-methylimidazole (1B2MZ). [Example]

[0044] The present disclosure will be described below based on examples and comparative examples, but the present disclosure is not limited to these.

[0045] The composition ratios (parts by mass) of the resin compositions of the examples and comparative examples are shown in Table 1. Next, a method for producing an epoxy resin composition based on the composition ratios shown in Table 1 will be described, but the method is not limited to this.

[0046] [Examples 1 to 5, Comparative Examples 1 to 3, 5 to 9] For each example and comparative example, the mass of each material in the epoxy resin composition shown in Table 1 was measured. Materials other than the curing agent were kneaded using a stirring defoamer (HIVIS MIX model 3, manufactured by Tokushu Kikai Kogyo Co., Ltd., 600 rpm, vacuum 5 min). The remaining curing agent was then added, and the mixture was kneaded using the stirring defoamer (600 rpm, vacuum 5 min) and filled into a syringe. It was then used in each test.

[0047] Comparative Example 4 The mass of each material in the epoxy resin composition shown in Table 1 was measured, and the materials other than the curing agent were stirred and degassed. The mixture was kneaded using a mixing machine (HIVIS MIX model 3, manufactured by Tokushu Kikan Kogyo Co., Ltd., 600 rpm, vacuum 5 min). Powdered BTDA was then added and mixed by hand. After the powder was sufficiently wetted, it was crushed using a three-roll mill to obtain a kneaded mixture. The remaining curing agent was then added as in the examples, and the mixture was kneaded using a mixing deaerator (600 rpm, vacuum 5 min) and filled into a syringe. The mixture was then used in each test.

[0048] The epoxy resin compositions of the Examples and Comparative Examples prepared by the above-described method were evaluated by the following test methods. The results are shown in Table 1.

[0049] [Ink resistance] The cured resin composition was immersed in service head ink (Canon) and subjected to an accelerated test at 105°C for 100 hours, and the ink resistance was evaluated based on the change in adhesion and mass before and after immersion in the ink. Specifically, to evaluate adhesiveness, a 2 mm square chip was placed on a silicon substrate and cured with each epoxy resin composition by heating, then immersed in the ink and evaluated for shear strength. The rate of change in shear strength before and after immersion was evaluated. In addition, 2.0 g of adhesive was cured and immersed in 20 times the amount of ink to evaluate the change in mass. The adhesive strength was measured by fixing the silicon substrate and measuring the shear strength of a 2 mm square chip. The rate of change in adhesive strength was measured before and after immersion in ink, and the rate of change was calculated. A: The mass change before and after immersion in ink is less than 10%, the adhesive strength after immersion in ink is 10 kgf or more, and the change in adhesive strength is less than 30% B: The mass change before and after immersion in ink is 10% or more, or the strength after immersion in ink is less than 10 kgf, or the change in adhesive strength is 30% or more

[0050] [Bleeding resistance] The epoxy resin composition was applied to an adherend (PS+PPE resin substrate) to a thickness of 100 μm, then pressed down to a thickness of 10 μm and 20 μm with another adherend, and cured at 100°C for 1 hour. The adherend was then peeled off and the presence or absence of uncured components was observed. Bleed resistance was then evaluated according to the following evaluation criteria. A: 10 μm thick with no uncured components B: There is uncured material at a thickness of 10 μm, but not at 20 μm C: 20 μm thick with uncured components

[0051] Elasticity Modulus A test piece of 5 mm wide, 0.6 mm thick, and 20 mm long was prepared by curing the epoxy resin composition, and the storage modulus was measured at 25°C and 1.0 Hz using a DMA measuring device (Hitachi High-Tech Science DMS6100). A: Storage modulus less than 1.5 GPa B: Storage modulus 1.5 GPa or more and less than 2.5 GPa C: Storage modulus 2.5GPa or more

[0052] [Temporary fastening] The gel time of each epoxy resin composition was measured at 130°C in a thickness of 100 μm. Specifically, the gel time is the time it takes for the epoxy resin composition to gel on a hot plate set at 130°C. The interval was measured S: Gel time less than 20 seconds A: Gel time: 20 seconds or more, less than 30 seconds B: Gel time 30 seconds or more, less than 60 seconds C: Gel time 60 seconds or more

[0053] As shown in Examples 1 to 5, when the equivalent ratio of epoxy resin to curing agent was 1:1 to 2:3, good results were obtained in all evaluation items. Furthermore, Examples 1 to 4 show that when the equivalent ratio of amine curing agent to acid anhydride curing agent was 1:1 to 4:1, a well-balanced epoxy resin adhesive was obtained. Example 5 further added an aliphatic amine curing agent (E), which further improved temporary bonding properties.

[0054] In Comparative Examples 1 to 5, when an amine-based resin and an acid anhydride-based resin were used without combining them, problems remained with regard to ink resistance, elastic modulus, and temporary adhesion. In Comparative Examples 6 and 7, the equivalent ratio of the base resin to the curing agent was 1:2 and 2:1, respectively, but problems remained with regard to ink resistance and temporary adhesion, and in Comparative Example 6, elastic modulus. In Comparative Examples 8 and 9, only a bisphenol-type epoxy resin or only a hydrogenated bisphenol-type epoxy resin was used, but problems remained with regard to the required properties.

[0055] [Table 1] Regarding the equivalent ratio, for example, in Comparative Example 1, the molecular weight of the epoxy resin mixture (A) as the main component is 400, the number of epoxy groups is 2, and 100 parts by mass is used, so A in the equivalent ratio is 2 (= 400 / (2 × 100)). Similarly, B is also 2, and the equivalent ratio A:(B + C) is 1:1.

[0056] The materials used are as follows: jER828:Mitsubishi Chemical Corporation YX8000: Mitsubishi Chemical Corporation Ethacure 300: Dimethylthiotoluenediamine, Mitsui Fine Chemicals, Inc. Ethacure 420: 4,4'-methylenebis[N-(1-methylpropyl)aniline], Mitsui Chemicals Fine Co., Ltd. Hexamethylenediamine: Tokyo Chemical Industry Co., Ltd. Rikacid DDSA: New Japan Chemical Co., Ltd. BTDA: Sigma-Aldrich IB2MZ: Shikoku Kasei Holdings Co., Ltd.

[0057] The present disclosure relates to the following configurations and methods. (Configuration 1) A liquid ejection head made up of a plurality of members, At least one of the members is bonded with a cured adhesive, The adhesive comprises at least (A) epoxy resin, (B) a liquid aromatic amine curing agent; (C) a liquid acid anhydride curing agent, and (D) catalyst; A resin composition comprising: In the resin composition, the equivalent ratio of the (A) epoxy resin to the sum of the (B) liquid aromatic amine curing agent and the (C) liquid acid anhydride curing agent is A:(B+C)=1:1 to 2:3; The equivalent weight in the ratio of the amount of equivalents is defined as equivalent weight = molecular weight / (number of functional groups x mass of compound), A liquid ejection head, wherein the (A) epoxy resin comprises (A-1) a bisphenol A type epoxy resin and (A-2) a hydrogenated bisphenol A type epoxy resin. (Configuration 2) In the resin composition, the equivalent ratio (B:C) of the (B) liquid aromatic amine curing agent to the (C) liquid acid anhydride curing agent is 1:1 to 4:1, 2. The liquid ejection head according to claim 1, wherein the equivalent weight in the relevant ratio is defined as equivalent weight=molecular weight / (number of functional groups×mass of compound). (Configuration 3) 3. The liquid ejection head according to configuration 1 or 2, wherein the (A) epoxy resin contains 10 to 80 mass % of the (A-1) bisphenol A type epoxy resin and 10 to 50 mass % of the (A-2) hydrogenated bisphenol A type epoxy resin. (Configuration 4) 4. The liquid ejection head according to any one of configurations 1 to 3, wherein the resin composition further contains (E) an aliphatic amine curing agent. (Configuration 5) 5. The liquid ejection head according to any one of configurations 1 to 4, wherein the cured product of the adhesive has a storage modulus of 0.01 to 1.5 GPa at 25° C. and 1.0 Hz. (Configuration 6) 25℃, 1.0s -1 6. The liquid ejection head according to any one of configurations 1 to 5, wherein the viscosity of the resin composition is 500 to 100,000 mPa·s. (Method 7) A method for manufacturing a liquid ejection head according to any one of configurations 1 to 6, comprising: The manufacturing method includes a step of bonding at least one of the members with the adhesive. A method for manufacturing a liquid ejection head, comprising: [Explanation of symbols]

[0058] 1 inkjet head, 2 recording element substrate, 3 supply flow path, 4 support member, 5 flow path Materials, 6 first flow path member, 7 second flow path member, 8 third flow path member

Claims

1. A liquid ejection head made up of a plurality of members, At least one of the members is bonded with a cured adhesive, The adhesive comprises at least (A) an epoxy resin, (B) a liquid aromatic amine curing agent; (C) a liquid acid anhydride curing agent, and (D) catalyst; A resin composition comprising: In the resin composition, the equivalent ratio of the epoxy resin (A) to the total of the liquid aromatic amine curing agent (B) and the liquid acid anhydride curing agent (C) is A:(B+C)=1:1 to 2:3; The equivalent weight in the ratio of equivalent amounts is defined as equivalent weight = molecular weight / (number of functional groups x mass of compound), The liquid ejection head is characterized in that the epoxy resin (A) comprises (A-1) a bisphenol A type epoxy resin and (A-2) a hydrogenated bisphenol A type epoxy resin.

2. In the resin composition, the equivalent ratio (B:C) of the liquid aromatic amine curing agent (B) to the liquid acid anhydride curing agent (C) is 1:1 to 4:1, 2. The liquid ejection head according to claim 1, wherein the equivalent weight in the corresponding ratio is defined as equivalent weight=molecular weight / (number of functional groups×mass of compound).

3. 3. The liquid ejection head according to claim 1, wherein the epoxy resin (A) contains 10 to 80% by mass of the bisphenol A epoxy resin (A-1) and 10 to 50% by mass of the hydrogenated bisphenol A epoxy resin (A-2).

4. The liquid ejection head according to claim 1 or 2, wherein the resin composition further comprises (E) an aliphatic amine curing agent.

5. 3. The liquid ejection head according to claim 1, wherein the cured product of the adhesive has a storage modulus of elasticity at 25° C. and 1.0 Hz of 0.01 to 1.5 GPa.

6. 25°C, 1.0 s －１ 3. The liquid ejection head according to claim 1, wherein the viscosity of the resin composition is 500 to 100,000 mPa·s.

7. 3. A method for manufacturing a liquid ejection head according to claim 1, further comprising the steps of: The manufacturing method includes a step of bonding at least one of the members with the adhesive. A method for manufacturing a liquid ejection head, comprising:

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