Inkjet recording head

Abstract

An inkjet recording head comprising: a substrate having ejection holes for ejecting liquid and a member provided with a recess for accommodating the substrate, the recording head comprising a gap formed between a wall of the recess of the member and the substrate, and a sealing material for sealing the gap, wherein the sealing material contains a cured product of a composition containing at least a hydrogenated bisphenol A type epoxy resin, a solid alkaline compound, and a polythiol.

Description

Technical Field

[0001] The present disclosure relates to an inkjet recording head in which components constituting the inkjet recording head are sealed with a sealing material. Background Art

[0002] An inkjet recording head is a device that has multiple energy generating elements and ejects liquid from multiple ejection holes by energy applied from the energy generating elements. An example of an inkjet recording head is an inkjet recording head mounted on an inkjet recording device that records by ejecting ink onto recording paper.

[0003] An inkjet recording head includes various components such as a substrate having ejection holes for ejecting ink and electrical wiring for electrically controlling the ejection. After the various components are assembled in the inkjet recording head, gaps are filled with a sealing material to prevent ink from entering the gaps between the components.

[0004] As such a sealing material, Japanese Patent No. 2904629 describes a sealing material including a polyurethane resin obtained by reacting a polyol compound with an isocyanate compound. Summary of the Invention

[0005] Sealing materials used in inkjet recording heads require various properties. For example, they need to be insulating when sealing electrical wiring, they need to be ink-resistant in areas where ink adheres, and they need to be scratch-resistant during cleaning.

[0006] In addition, in recent years, one aspect of inkjet recording head has changed in various ways, and it is necessary to have the sealing performance of the shape and material that is suitable for adhered member (adhered member). Therefore, low viscosity and flatness are also needed so that they can be evenly cast between thin members. In addition, in the structure that the adhered member is elongated like a long head, it is worried that the adhered member may be deformed due to the difference in the linear expansion coefficient between the adhered member and the sealing material. Therefore, low temperature curing is also needed so that the member can not be deformed.

[0007] On the other hand, in terms of productivity, materials that can shorten equipment maintenance time are needed. In the case of a two-liquid mixing dispenser, since the mixing part is reused, the cleaning step takes time and productivity decreases. In addition, when using materials, from the perspective of stereoregularity and stability, it is desired that the sealing material has a long pot life. In addition, when using materials, from the perspective of stability and productivity, it is desired that the sealing material has a long pot life and cures in a short time.

[0008] A polyurethane resin obtained by reacting a general polyol compound with an isocyanate compound as described in Japanese Patent No. 2904629 may not fully meet these requirements.

[0009] Therefore, an object of the present disclosure is to provide an ink jet recording head sealed with a sealing material having excellent sealing performance, moldability, and productivity.

[0010] According to one aspect of the present disclosure, there is provided an inkjet recording head comprising a substrate having ejection holes for ejecting liquid and a member provided with a recess for accommodating the substrate, the head comprising a gap formed between a wall of the recess of the member and the substrate, and a sealing material for sealing the gap, wherein the sealing material comprises a cured product of a composition containing at least a hydrogenated bisphenol A type epoxy resin, a solid alkaline compound, and a polythiol.

[0011] In addition, according to another aspect of the present disclosure, there is provided a suitable method for manufacturing a sealing material for an inkjet recording head, as described below.

[0012] A method for producing a sealing material, comprising kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1, and kneading the mixture 1 and a polythiol to produce a mixture 2.

[0013] A method for producing a sealing material, comprising: kneading a hydrogenated bisphenol A type epoxy resin and a solid alkaline compound to produce a mixture 1, kneading the hydrogenated bisphenol A type epoxy resin and a silica filler to produce a mixture 3, and kneading the mixture 1, the mixture 3, and a polythiol to produce a mixture 4.

[0014] A method for producing a sealing material, comprising kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1, kneading the hydrogenated bisphenol A type epoxy resin, a silica filler, and a polythiol to produce a mixture 5, and kneading the mixture 1 and the mixture 5 to produce a mixture 6.

[0015] Furthermore, according to still another aspect of the present disclosure, there is provided a method of manufacturing an inkjet recording head, the method including using a sealing material manufactured by the manufacturing method.

[0016] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view showing one aspect of the inkjet recording head.

[0018] Figure 2A It is a partially enlarged view of the inkjet recording head.

[0019] Figure 2B It is along Figure 2A A cross-sectional view taken along line AA' shown in FIG.

[0020] Figure 3The change in viscosity due to the passage of time in Example 15 and Example 17 is shown. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present disclosure will be described in detail.

[0022] <Inkjet Recording Head>

[0023] First, the configuration of the inkjet recording head in the present disclosure will be described with reference to the drawings. Figure 1 is a perspective view of one aspect of the inkjet recording head of the present disclosure. Figure 2A is a partially enlarged view of the inkjet recording head, and Figure 2B It is along Figure 2A 1 is a cross-sectional view of the ink jet recording head taken along line AA′ shown in FIG.

[0024] The inkjet recording head 1 includes a substrate 2 and a member 3 supporting the substrate 2. The substrate 2 includes ejection holes 4 for ejecting ink, energy generating elements (not shown) for generating energy for ejecting ink, and electronic circuit elements (not shown) for controlling the energy generating elements.

[0025] The inkjet recording head 1 is a so-called line head capable of high-speed printing. A line head is one with a width equal to or greater than the width of the recording paper, in which multiple substrates 2 are arranged in a line along the width. Multiple substrates 2 are arranged continuously on the inkjet recording head 1, with a length equal to or greater than the width of the recording paper. This allows recording to be performed across the entire width of the recording paper by passing the recording paper through it once, with the inkjet recording head being stationary. Here, the width of the short side of an A4 sheet of paper is assumed to be the width of the recording paper.

[0026] A plurality of substrates 2 arranged in a line are housed in a recess 3b provided in a member 3. When the inkjet recording head 1 is viewed from the surface side where the ejection holes are opened, gaps are formed between the substrates 2 and the side walls 3a of the recess 3b of the member 3. Furthermore, gaps may exist between the substrates 2. These gaps are sealed by a sealing material 5. The sealing material 5 is formed by pouring a sealing material composition into the gaps between the substrates 2 and the side walls 3a of the recess 3b of the member 3 and curing the composition.

[0027] <Composition for Sealing Material>

[0028] Next, the composition for the sealing material will be described below. The epoxy resin composition for the sealing material used in the present disclosure contains at least a hydrogenated bisphenol A type epoxy resin, a solid basic compound, and a polythiol.

[0029] The above composition is a composition having appropriate sealing properties, moldability and productivity so as to become a desired sealing material. First, the properties of the above composition will be described.

[0030] Sealing performance

[0031] The sealing material used in the inkjet recording head needs to have the ink resistance of anti-ink contact and the scratch resistance of anti-cleaning.The sealing material used in the present disclosure is solidified by the mercaptan solidification (anionic polymerization) of the polythiol contained in the composition, and even after solidification, the functional group such as hydroxyl residue that helps to adhere. In addition, -S- derived from mercaptan is flexible, and even in harsh environments, it is also possible to expect strong adhesion to the adhered member. Therefore, it is possible to prevent the ink from penetrating the interface between the adhered member and the sealing material from invading. In addition, owing to the use of epoxy resin, it is possible to obtain excellent mechanical strength, and it is possible to ensure scratch resistance.

[0032] Formability

[0033] Since the sealing material must be poured into Figure 2A and 2B In the concave portion 3b with a narrow width of several tens of micrometers to several millimeters between the multiple substrates 2 arranged in a linear manner as shown in , it is preferred that the sealing material has a low viscosity. The viscosity of the sealing material is preferably 40Pa·s or lower. In addition, it is desired that the sealing material has low elasticity so as not to generate stress on the head member due to the temperature increase during the installation step of the inkjet recording head or the printing of the printer. From this point of view, the elastic modulus of the sealing material is preferably 20GPa or less, and more preferably 10GPa or less. As the sealing material used in the present disclosure, from the viewpoint of low viscosity and low elasticity, hydrogenated bisphenol A type epoxy resin is used as the epoxy resin.

[0034] Furthermore, when the area sealed by the sealing material is large, there is a risk of deformation of the adhesive material or damage to the components when thermally curing at high temperatures due to the difference in linear expansion with the adhesive material. Therefore, compositions that can be cured at room temperature or at low temperatures of 100°C or lower are effective. Since the reaction rate of epoxy resins caused by anionic polymerization is generally slow, the sealing material according to the present disclosure is improved in reactivity by adding a polythiol as a curing agent.

[0035] ·productivity

[0036] For productivity, storage stability is required. Ideally, the pot life is 8 hours or longer at room temperature, but the pot life of a single-liquid sealing material is generally shorter than that of a double-liquid sealing material. When the sealing material of the present invention contains a hydrogenated bisphenol A type epoxy resin, a solid alkaline compound and a polythiol, a sufficient pot life can be obtained. In order to delay the curing reaction and obtain a more sufficient pot life, as described below, it is preferred to first mix the hydrogenated bisphenol A type epoxy resin and the solid alkaline compound and mix the obtained mixture with polythiol. This is because when the epoxy resin and the solid alkaline compound are first mixed, the solid alkaline compound is coated with the epoxy resin. Therefore, it takes time for the solid alkaline compound to dissolve in the polythiol. As a result, this is because the time until the reaction between the epoxy resin and the polythiol begins can be delayed. Therefore, even if the viscosity of the single liquid increases slowly at room temperature, a sufficient pot life can be obtained. The definition of pot life is the time that can stay at room temperature, which becomes twice the value of the viscosity immediately after mixing.

[0037] Next, each of the constituent components of the composition for the sealing material will be explained.

[0038] (Epoxy resin)

[0039] The epoxy resin is the main agent (the most abundant curing component in the composition), and hydrogenated bisphenol A epoxy resin is used. Hydrogenated bisphenol A epoxy resin does not contain double bonds and aromatic rings, and has a small molecular weight distribution as a structure for reducing elasticity. In addition, from the perspective of reducing viscosity, hydrogenated bisphenol A epoxy resin is preferably a high-purity resin, and post-hydrogenated bisphenol A epoxy resin formed by a post-hydrogenation method is more preferred.

[0040] In addition, from the viewpoint of storage stability, epoxy resin is preferably alicyclic epoxy resin. This is because alicyclic epoxy resin is effective in extending the pot life because the reactivity is reduced in anionic polymerization systems. In addition, as mentioned above, in order to cover the solid alkaline compound with hydrogenated bisphenol A type epoxy resin, it is effective that the epoxy resin is in a liquid state. In the case of using a solid epoxy resin at room temperature, the solid alkaline compound can be heated to a temperature at which the solid alkaline compound does not melt to make the solid alkaline compound liquid, or it can be dissolved in other liquid epoxy resins. Specific examples of epoxy resins include jER YX8000, YX8000D, YX8034 and YX8040, which are hydrogenated epoxy resin series manufactured by Mitsubishi Chemical Corporation.

[0041] The hydrogenated bisphenol A type epoxy resin may be one kind or may contain two or more kinds.

[0042] (Polythiol)

[0043] Polythiol is used as a curing agent. There is no particular limitation on the polythiol, but generally a polythiol having high reactivity and a relatively low molecular weight is selected. As such a polythiol, a polythiol that is liquid at room temperature can be advantageously used.

[0044] Examples thereof include pentaerythritol tripropyl mercaptan (PEPT), trimethylolpropane tris(3-mercaptopropionate) (TMMP), pentaerythritol tetrakis(3-mercaptopropionate), p-xylenedithiol, and the like.

[0045] Examples of commercially available products include PEPT (manufactured by SC Organic Chemical Co., Ltd.), TMMP (manufactured by SCOrganic Chemical Co., Ltd.), Cup Cure 3-800 (trade name, manufactured by Mitsubishi Chemical Corporation), QX11 (trade name, manufactured by Mitsubishi Chemical Corporation) and the like.

[0046] When the sealing material of the present disclosure is used in areas requiring greater chemical resistance, polythiols with an ether backbone, particularly ether-type multifunctional thiols, are preferred for their greater chemical resistance. Polythiols with an ether backbone are compounds having two or more thiol groups in their side chains, lacking a hydrolyzable ester bond in the main chain and containing ether bonds that exhibit excellent properties, such as chemical resistance due to high bond strength. Furthermore, polythiols with an ether backbone are also effective in reducing viscosity.

[0047] The content of polythiol is preferably such that the thiol equivalent of polythiol is 0.5 to 1 equivalent relative to the epoxy equivalent of 1 equivalent of hydrogenated bisphenol A type epoxy resin. When the polythiol is 0.5 equivalent or greater relative to the equivalent of epoxy resin, the reaction between epoxy resin and polythiol occurs at a sufficiently fast rate and can be cured in a short time. In addition, when the equivalent of polythiol is 0.5 equivalent or greater, the polymerization reaction between epoxy resin and polythiol is carried out as the main reaction, and as a side reaction, the polymerization reaction between epoxy resin and the base derived from the solid basic compound is difficult to occur. As a result, the thioether structure (-S-) derived from polythiol necessary for obtaining flexibility is fully formed, which is preferred from the viewpoint of adhesion. When the equivalent of polythiol relative to epoxy resin is 1 equivalent or less, the amount of unreacted polythiol that cannot react with epoxy resin is reduced. The deterioration of mechanical properties caused by unreacted polythiol, such as the deterioration of adhesion, is prevented. In addition, even when the sealing material is used in a portion in contact with ink, the generation of unreacted polythiol is prevented, so that the unreacted polythiol is not eluted into the ink. Therefore, it is preferable because the sealing material is prevented from swelling with ink.

[0048] (Solid basic compound)

[0049] The solid basic compound is used as a curing catalyst. There are no particular limitations on the solid basic compound as long as it is solid at room temperature, but it is preferable to use a compound that is poorly soluble in the epoxy resin.

[0050] Examples thereof include dicyandiamide, dihydrazide compounds, solid aromatic amines such as diaminodiphenylmethane (DDM) and diaminodiphenylsulfone (DDS), various imidazoles, and various amine adduct-based latent curing agents commonly used as latent curing agents. In particular, amine adduct-based latent curing agents are used as compounds suitable for curing epoxy resins.

[0051] The preferred content range of the solid basic compound depends on the use conditions.

[0052] For example, the content of the solid alkaline compound is preferably 1.5-2.5 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. When the content of the solid alkaline compound relative to the epoxy resin is 1.5 parts by mass or more, curing can be performed in a short time. When the content of the solid alkaline compound relative to the epoxy resin is 2.5 parts by mass or less, the solid alkaline compound is fully coated with the epoxy resin, the amount of the solid alkaline compound dissolved in the polythiol is reduced, and a sufficient pot life can be obtained. In addition, when the use conditions require rapid curing at a low temperature of about room temperature, the content of the solid alkaline compound is preferably 2.5-10 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. When the content of the solid alkaline compound relative to the epoxy resin is 2.5 parts by mass or more, sufficient acceleration of curing can be expected, and when the content of the solid alkaline compound relative to the epoxy resin is 10 parts by mass or less, the amount of non-curing components is appropriate.

[0053] (Silane reagent (silane coupling agent))

[0054] A silane agent can be further added to the sealing material according to the present disclosure. Preferably, a silane agent with a low molecular weight is added as a configuration for reducing viscosity. As the silane agent, a silane agent with a molecular weight of 500 or less and preferably a silane agent with a molecular weight of 300 or less can be used. In addition, as the silane agent added, a compound with an alicyclic epoxy skeleton having a low viscosity characteristic is effective.

[0055] In addition, examples of preferred modifying groups of silane reagents include epoxy, mercapto, isocyanate, and fluorene skeletons. However, basic silane coupling agents such as amine compounds act as catalysts, the reaction starts immediately, and the pot life is shortened, making basic silane coupling agents unsuitable for use.

[0056] In addition, in the case where the sealing material according to the present disclosure is used in a situation where stronger adhesion is required at the interface between the adhered member and the sealing material, the silane agent preferably has an epoxy group or a mercapto group.

[0057] In the sealing material according to the present disclosure, since the main agent is epoxy resin and the curing agent is polythiol, the sealing material has good compatibility with these silane coupling agents, and it is considered that peeling at the interface between the adhered member and the sealing material is difficult to occur.

[0058] The preferred content range of the solid basic compound depends on the use conditions.

[0059] For example, the content of the silane agent is preferably 1-50 parts by mass, relative to 100 parts by mass of hydrogenated bisphenol A type epoxy resin. When the content of the silane agent relative to the epoxy resin is 1 part by mass or greater, it is also possible to improve adhesion to inorganic components, and when the content is 50 parts by mass or less, the residual unreacted components of the silane agent can be suppressed. In addition, when the conditions of use require swelling resistance, pot life and low viscosity, the content of the preferred silane agent is 50-75 parts by mass, relative to 100 parts by mass of hydrogenated bisphenol A type epoxy resin. It is expected that compounds with inorganic components that are not easy to swell (such as silane agents and silica fillers described later) will improve swelling resistance according to the amount added. In addition, since the silane agent has less reactive groups than epoxy resin in one molecule, it is expected to have an effect of extending the pot life. On the other hand, because reactivity tends to be low, it is preferred to adjust the amount of the added thiol (which is a curing agent) to achieve pot life and curability at the same time.

[0060] The order of mixing the silane coupling agents is not particularly limited, but it is preferred that the epoxy group-containing silane coupling agent be mixed with the main epoxy resin and the mercapto group-containing silane coupling agent be mixed with the polythiol at the same timing.

[0061] (Other additives)

[0062] Diluents and other additives may optionally be added to the composition for the sealing material containing the above-mentioned components.

[0063] For example, silica fillers can be added as needed. By adding silica fillers, it is possible to impart swelling resistance and storage stability, which are the original properties of silica fillers. In addition, by adding silica fillers, it is possible to suppress the linear expansion coefficient and suppress the deformation of the adhered member. As the type of silica filler, a general silica filler can be used, but a slightly larger microsilica filler (particle diameter: about 10 μm to 100 nm) or a large silica filler (particle diameter: about 100 μm to 10 μm) having a particle diameter of 0.1 μm or more is preferred for the purpose of suppressing viscosity increase. The particle diameter represents the volume cumulative particle diameter D50 measured by a laser diffraction and scattering type particle size distribution measuring device.

[0064] Furthermore, in order to enhance affinity with other materials, silica fillers treated with silane or the like are also suitable.

[0065] The content of the silica filler is preferably 100 to 800 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. When the content of the silica filler relative to the epoxy resin is 100 parts by mass or more, swelling properties can be suppressed, and when the content of the silica filler relative to the epoxy resin is 800 parts by mass or less, viscosity can be suppressed to a coating viscosity.

[0066] In addition, in order to apply the sealing material with high precision, a pigment can be added to detect the amount of the sealing material applied. For the pigment, a dispersant can be added to disperse it well.

[0067] Next, a method of producing a composition for a sealing material will be described.

[0068] (Method for producing a composition for a sealing material)

[0069] In the method of manufacturing a sealing material according to the present disclosure, for the purpose of suppressing dissolution of a solid basic compound in polythiol, respective raw materials of the sealing material are mixed in the following order.

[0070] (Sealing material without silica filler)

[0071] In the method for producing a sealing material according to the present embodiment, a sealing material containing no silica filler is produced.

[0072] The production of a sealing material without silica filler can be carried out in the following sequence.

[0073] The method includes: a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1; and a step of kneading the mixture 1 and a polythiol to produce a mixture 2.

[0074] In the production method, it is particularly preferred to knead the mixture 1 and the polythiol to prepare the mixture 2 within 1 hour after the production of the mixture 1.

[0075] According to this production method, compared with the case where each component is kneaded together simultaneously without taking the above order, the viscosity is difficult to increase even when stored at room temperature, and it has a sufficient pot life.

[0076] In particular, mixing the polythiol within 1 hour after preparing the mixture 1 can suppress a rapid increase in viscosity and extend the pot life.

[0077] (Sealing material containing silica filler)

[0078] In the method for producing a sealing material according to the present embodiment, a sealing material containing a silica filler is produced.

[0079] There are two embodiments for producing a sealing material containing a silica filler. The first embodiment can be carried out in the following order.

[0080] The method includes: kneading a hydrogenated bisphenol A type epoxy resin and a solid alkaline compound to produce a mixture 1; kneading a hydrogenated bisphenol A type epoxy resin and a silica filler to produce a first mixture 3; and kneading the mixture 1, the mixture 3 and a polythiol to produce a mixture 4.

[0081] In the production method, it is particularly preferred to mix mixture 1 with mixture 3 and polythiol within 1 hour after production of mixture 1 to produce mixture 4. According to this production method, the sealing material kneaded in this order has a longer pot life.

[0082] In particular, mixing the polythiol within 1 hour after preparing the mixture 1 can suppress a rapid increase in viscosity and extend the pot life.

[0083] The second embodiment can be performed in the following order.

[0084] The method includes kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1, kneading a hydrogenated bisphenol A type epoxy resin, a silica filler and a polythiol to produce a mixture 5, and kneading the mixture 1 and the mixture 5 to produce a mixture 6.

[0085] In the production method, it is preferred that the hydrogenated bisphenol A type epoxy resin, the silica filler, and the polythiol are kneaded to produce the mixture 5 within 1 hour after the production of the mixture 1, and the mixture 1 and the mixture 5 are kneaded to produce the mixture 6.

[0086] According to the manufacturing method in this case, the silica filler increases the viscosity of the mixture 5 and further suppresses contact between the solid basic compound coated with the hydrogenated bisphenol A type epoxy resin and the polythiol. In addition, a silane agent may be added to the mixture 5. By simply mixing the amounts of each mixture, the epoxy resin used in the above mixture can be appropriately adjusted.

[0087] In particular, mixing the polythiol within 1 hour after preparing the mixture 1 can suppress a rapid increase in viscosity and extend the pot life.

[0088] [Example]

[0089] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to examples.

[0090] Examples 1 to 12 and Comparative Examples 1 and 2

[0091] <Preparation of Composition for Sealing Material>

[0092] Table 1 shows the materials used in Examples and Comparative Examples, the composition ratios of the materials, and the evaluation results.

[0093] In Examples 1 to 10, a hydrogenated bisphenol A type epoxy resin as a main reagent and a solid basic compound as a catalyst were kneaded to obtain a mixture A. After 12 hours, a mixture B in which the same epoxy resin and a silica filler were kneaded, a polythiol as a curing agent, and a silane agent were added and kneaded (mixture A + B + curing agent + silane agent).

[0094] In Example 11, an epoxy resin as a main reagent and a solid basic compound as a catalyst were kneaded to obtain a mixture A, and after 12 hours, the mixture A, polythiol, a silica filler and a silane reagent were kneaded to obtain a mixture C.

[0095] In Example 12 and Comparative Examples 1 and 2, all materials were kneaded simultaneously.

[0096] In HIVIS MIX Model 3 manufactured by Primix Corporation, kneading of epoxy resin and thixotropic agent as main agents was performed in a vacuum at 1000 rpm for 2 minutes, and kneading other than epoxy resin and thixotropic agent was performed in a vacuum at 600 rpm for 5 minutes.

[0097] <Evaluation Method of Sealing Material>

[0098] The sealing materials formed using the compositions of Examples 1 to 12 and Comparative Examples 1 and 2 were evaluated in the following six types.

[0099] ·insulation

[0100] The compositions of Examples 1 to 12 and Comparative Examples 1 and 2 were placed in a mold and allowed to cure at room temperature for one day or longer. The resulting cured product was removed from the mold and used as an evaluation sample for a sealing material. The volume resistivity of the evaluation sample was measured. The volume resistivity was determined using the test method ISO 2951 and an applied voltage of 500 V.

[0101] Ink resistance

[0102] The evaluation sample was immersed in an ink (water: organic solvent: surfactant = 75:25:1) with a mass ratio 20 times that of the evaluation sample and heated at 105°C for 10 hours. For evaluation purposes, this ink did not contain a coloring material. The mass of the evaluation sample before and after heating was measured, and the ink absorption rate was determined based on the mass of the evaluation sample before heating.

[0103] Durability

[0104] The compositions of Examples 1 to 12 and Comparative Examples 1 and 2 were poured into Figure 1 In the part of the sealing material 5 of the inkjet recording head 1 shown in , to prevent air bubbles from entering. The composition is retained for one day or longer to cure the composition. By rubbing the inkjet recording head 1000 times with a scraper (made of acrylonitrile butadiene rubber), the inkjet recording head obtained is subjected to a durability test, and the presence or absence of scratches or abrasions on the surface of the sealing material after the durability test is confirmed with an optical microscope.

[0105] Elastic modulus

[0106] Using the above-mentioned evaluation sample, the elastic modulus (E') and tan δ were measured by a dynamic viscoelasticity measuring apparatus DMS6100 (manufactured by Seiko Instruments Inc.) in a tensile mode with a sample-to-sample length of 15 mm, a measuring frequency of 1 Hz, and a measuring temperature range of 20°C to 120°C at a heating rate of 2°C / min.

[0107] ·Applicable period

[0108] The pot life was calculated as the time until the viscosity became twice the initial viscosity.

[0109] Determined as follows.

[0110] ◎: The applicable period is more than 24 hours.

[0111] ○: The pot life is 8 hours or more and less than 16 hours.

[0112] ×: Pot life is less than 8 hours.

[0113] Viscosity

[0114] The resin compositions prepared in Examples 1 to 18 and Comparative Examples 1 and 2 were measured using a viscometer "TV-20" (manufactured by TokiSangyo Co., Ltd.).

[0115] <Evaluation of Sealing Materials>

[0116] (Examples 1-4 and 8)

[0117] In Examples 1 to 4, although the main sealing performance and storage stability were excellent, differences in viscosity were observed, and the viscosity was lowest at the level of A-187 added to the silane reagent of Example 2. This is believed to be due to the effect of adding a silane reagent having a low molecular weight to a hydrogenated bisphenol A type epoxy resin (which is an alicyclic epoxy resin). In Example 8, the main sealing performance and storage stability were similar to those of Examples 1 to 4, but the surface of the molded sample was smooth and excellent in flatness compared to the other examples.

[0118] (Example 5)

[0119] Although the sealing performance and storage stability were excellent, differences were observed in that the viscosity was slightly higher and the ink resistance was lowered compared to Example 2. This is considered to be due to the use of a thiol having an ester structure.

[0120] (Examples 6 and 7)

[0121] Although the main sealing performance was excellent, differences were observed in ink resistance and storage stability compared with Example 2. This is considered to be due to the use of a thiol having an ester structure.

[0122] (Examples 9 and 13)

[0123] Although the main sealing performance was excellent, the storage stability was slightly lower than that of Example 2. This is considered to be because the reactivity during storage was improved by increasing the amount of the solid basic compound.

[0124] (Example 10)

[0125] Although the main sealing properties and storage stability were excellent, a difference in viscosity was observed, and the viscosity was higher than that of Example 2. This is considered to be due to the effect of using the hydrogenated bisphenol A type epoxy resin.

[0126] (Example 11)

[0127] Although the main sealing performance and storage stability were excellent, a difference in viscosity was observed, and the viscosity was higher than that of Example 2. This was due to the difference in the mixing method, and it is considered that the silica filler was not sufficiently mixed with the other materials.

[0128] (Example 12)

[0129] Although the main sealing performance was excellent, differences in storage stability and viscosity were observed. Example 12 had a higher viscosity and lower storage stability than those of Example 2. This was attributed to differences in the mixing method and is believed to be due to the poor mixing conditions of the silica filler and the poor coating performance of the epoxy resin on the solid alkaline compound.

[0130] (Example 14)

[0131] The main sealing performance is excellent, and the initial viscosity is also suppressed. This is believed to be due to the increase in the amount of silane reagent and solid basic compound.

[0132] (Comparative Examples 1 and 2)

[0133] In Comparative Examples 1 and 2, since the aromatic epoxy resin was used, the sealing performance was lower than that of Examples 1 to 12, and as a result, the function as a sealing material was not satisfied.

[0134] [Table 1] Table 1

[0135]

[0136]

[0137] In Table 1, for example, the fact that the column of post-hydrogenated bisphenol A of Example 1 is "10A 90B" means that the blending amount of post-hydrogenated bisphenol A is 10 of mixture A and 90 of mixture B, and the fact that the column of epoxy amine adduct is "2B" means that the blending amount of epoxy amine adduct in mixture B is 2.

[0138] (Example 15 to Example 18)

[0139] <Preparation of Composition for Sealing Material>

[0140] Table 2 shows the materials used in Examples and Comparative Examples and their composition ratios.

[0141] In Examples 15 and 16, a hydrogenated bisphenol A type epoxy resin as a main reagent and a solid basic compound as a catalyst were kneaded to obtain a mixture A. Within 1 hour, a mixture B in which the same epoxy resin and a silica filler were kneaded, a polythiol as a curing agent, and a silane reagent were added and kneaded (mixture A + B + curing agent + silane reagent).

[0142] In Examples 17 and 18, a hydrogenated bisphenol A type epoxy resin as a main reagent and a solid basic compound as a catalyst were kneaded to obtain a mixture A. After 12 hours, a mixture B in which the same epoxy resin and a silica filler were kneaded, a polythiol as a curing agent, and a silane agent were added and kneaded (mixture A + B + curing agent + silane agent).

[0143] In HIVIS MIX Model 3 manufactured by Primix Corporation, kneading of the epoxy resin and the thixotropic agent as main agents was performed in a vacuum at 1000 rpm for 2 minutes, and kneading other than the epoxy resin and the thixotropic agent was performed in a vacuum at 600 rpm for 5 minutes.

[0144] <Evaluation Method of Sealing Material>

[0145] The sealing materials formed using the compositions of Examples 15 to 18 were evaluated as follows. The evaluation results are shown in Tables 3 and 4.

[0146] ·Applicable period

[0147] The pot life was calculated as the time until the viscosity became twice the initial viscosity.

[0148] Determined as follows.

[0149] ○: Pot life is 4 hours or more.

[0150] △: Pot life is less than 4 hours.

[0151] The resin compositions prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were measured using a viscometer "TV-20" (manufactured by TokiSangyo Co., Ltd.).

[0152] Curing time

[0153] Cure time is defined as the time required to cure at room temperature.

[0154] Determined as follows.

[0155] ○: Not sticky at room temperature for 30 hours.

[0156] △: Sticky after 30 hours at room temperature.

[0157] Response rate

[0158] The reaction rate was confirmed by differential scanning calorimetry (DSC) at room temperature for 30 hours.

[0159] <Evaluation of Sealing Materials>

[0160] (Example 15)

[0161] In Example 15, it was found that Figure 3 As shown in , the viscosity increased rapidly over time compared to Example 17, and the reaction rate was high at room temperature for 30 hours as shown in Table 3. This is considered to be because the reactivity was improved by mixing the polythiol within 1 hour after preparing the mixture A.

[0162] (Example 16)

[0163] The initial viscosity was suppressed compared to Example 16. This is considered to be due to the increase in the amount of the silane reagent and the solid basic compound.

[0164] (Examples 17 and 18)

[0165] In Examples 17 and 18, the storage stability was excellent, but the curing time was longer than that in Examples 15 and 16.

[0166] [Table 2]

[0167]

[0168] In Table 1, for example, the fact that the column of post-hydrogenated bisphenol A of Example 1 is "10A90 B" means that the blending amount of post-hydrogenated bisphenol A is 10 for mixture A and 90 for mixture B, and the fact that the column of epoxy amine adduct is "10B" means that the blending amount of epoxy amine adduct is 10 in mixture B.

[0169] [Table 3]

[0170] Table 3

[0171] Applicable period Curing time Example 15 ○ ○ Example 16 ○ ○ Example 17 ○ △ Example 18 〇 △

[0172] [Table 4]

[0173] Table 4

[0174] Response rate Example 15 96％ Example 17 79％

[0175] According to the present disclosure, there is provided an ink jet recording head sealed with a sealing material having sealing performance, moldability, and productivity.

[0176] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. An inkjet recording head comprising a substrate having an ejection hole for ejecting liquid and a member provided with a recess for accommodating the substrate, the recording head comprising a gap formed between a wall of the recess of the member and the substrate; and a sealing material for sealing the gap, wherein The sealing material contains a cured product of a composition containing at least a hydrogenated bisphenol A type epoxy resin, a solid basic compound, a polythiol and a silane agent, Wherein, the silane reagent has an alicyclic epoxy skeleton, Wherein, the polythiol is at least one selected from pentaerythritol tripropyl mercaptan and trimethylolpropane tris(3-mercaptopropionate).

2. The inkjet recording head according to claim 1, wherein The viscosity of the composition is 40 Pa·s or less.

3. The inkjet recording head according to claim 1, wherein The molecular weight of the silane agent is 300 or less.

4. The inkjet recording head according to claim 1, wherein The content of the silane agent is 1 to 50 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin.

5. The inkjet recording head according to claim 1, wherein The elastic modulus of the sealing material is 20 GPa or less.

6. The inkjet recording head according to claim 1, wherein The solid alkaline compound is an amine adduct-based latent curing agent.

7. The inkjet recording head according to claim 1, wherein The polythiol is an ether-type multifunctional thiol.

8. The inkjet recording head according to claim 7, wherein The polythiol is contained in an amount such that the polythiol has a thiol equivalent of 0.5 to 1 equivalent relative to 1 equivalent of epoxy of the hydrogenated bisphenol A type epoxy resin.

9. The inkjet recording head according to claim 1, wherein The composition contains a silica filler.

10. The inkjet recording head according to claim 9, wherein The silica filler has a particle diameter of 0.1 μm or greater.

11. The inkjet recording head according to claim 9, wherein The silica filler is treated with a silane.

12. The inkjet recording head according to claim 1, wherein The content of the solid alkaline compound is 1.5-2.5 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A epoxy resin.

13. The inkjet recording head according to claim 1, wherein The hydrogenated bisphenol A epoxy resin is a post-hydrogenated bisphenol A epoxy resin.

14. The inkjet recording head according to claim 1, wherein The content of the silane agent is 50 to 75 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin.

15. The ink jet recording head according to claim 1, wherein The content of the solid alkaline compound is 2.5-10 parts by mass relative to 100 parts by mass of the hydrogenated bisphenol A epoxy resin.

16. A method for producing a sealing material for an ink jet recording head, the method comprising: kneading a first hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1; kneading a second hydrogenated bisphenol A type epoxy resin and a silica filler to produce a mixture 3; kneading the mixture 1, the mixture 3 and polythiol to produce a mixture 4, Wherein, the polythiol is at least one selected from pentaerythritol tripropyl mercaptan and trimethylolpropane tris(3-mercaptopropionate), The first hydrogenated bisphenol A epoxy resin and the second hydrogenated bisphenol A epoxy resin are hydrogenated bisphenol A epoxy resins of the same type.

17. The method for producing a sealing material for an ink jet recording head according to claim 16, wherein The step of kneading the mixture 1 and the polythiol is performed within 1 hour after the mixture 1 is produced.

18. The method for producing a sealing material for an ink jet recording head according to claim 16, wherein The step of kneading the mixture 1, the mixture 3, and the polythiol is performed within 1 hour after the preparation of the mixture 1.

Images