JP2022170692A - inkjet recording head - Google Patents

Abstract

To provide an inkjet recording head which is sealed with a sealing material having sealing property, moldability and productivity.SOLUTION: An inkjet recording head has a substrate having a discharge port for discharging a liquid, and a member provided with a recess for storing the substrate, and has a sealing material for sealing a gap formed between a wall of the recess of the member and the substrate, wherein the sealing material includes at least a cured product of a composition containing a hydrogenated bisphenol A type epoxy resin, a solid basic compound and polythiol.SELECTED DRAWING: Figure 1

Description

The present invention relates to an inkjet recording head in which parts constituting the inkjet recording head are sealed with a sealing material.

2. Description of the Related Art An ink jet recording head is a device that has a plurality of energy generating elements and ejects liquid from a plurality of ejection openings by energy given from the energy generating elements. An example of an inkjet recording head is an inkjet recording head installed in an inkjet recording apparatus that performs recording by ejecting ink onto recording paper.
An ink jet recording head is composed of various components such as a substrate having ejection openings for ejecting ink and electrical wiring for electrically controlling ejection. In an inkjet recording head, after assembling various parts, the gaps are filled with a sealing material in order to prevent ink from penetrating into the gaps between the parts.
As such a sealing material, Patent Document 1 describes a sealing material containing a urethane resin obtained by reacting a polyol compound and an isocyanate compound.

Japanese Patent No. 2904629

Various performances are required for sealing materials used in inkjet recording heads. For example, insulation is required for sealing electrical wiring, ink resistance is required for portions to which ink adheres, and wiping resistance is required for cleaning.
In addition, recent ink jet recording heads have changed in various forms, and it is necessary to have a sealing property suitable for the shape and material of the adherend. Therefore, low viscosity and flatness are also required in order to flow evenly between narrow members. In addition, in a structure in which the adherend member is elongated, such as a long head, there is a concern that the adherend member may be deformed due to the difference in coefficient of linear expansion between the adherend member and the sealing material. Therefore, low-temperature curability to the extent that the member does not deform is also required.
On the other hand, in terms of productivity, there is a demand for materials that can shorten the maintenance time of equipment. In the case of a two-liquid mixing dispenser, since the mixing part is used repeatedly, it takes time for the cleaning process, resulting in a drop in productivity. In addition, it is desirable that the pot life of the encapsulant is long from the viewpoint of tactability and stability during use of the material. In addition, it is desirable that the pot life of the encapsulant is long and that the encapsulant cures in a short period of time from the standpoint of stability and productivity during use of the material.

A urethane resin obtained by reacting a general polyol compound and an isocyanate compound as described in Patent Document 1 may not be able to sufficiently satisfy these requirements.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording head sealed with a sealing material having excellent sealing properties, moldability and productivity.

The present invention provides an inkjet recording head comprising a substrate having ejection ports for ejecting liquid and a member provided with a concave portion for accommodating the substrate,
a gap formed between the wall of the recess of the member and the substrate, and a sealing material for sealing the gap;
The sealing material includes at least a cured product of a composition containing a hydrogenated bisphenol A type epoxy resin, a solid basic compound, and a polythiol. As described above, a suitable method for manufacturing a sealing material used in the ink jet recording head is provided.
A sealing material comprising a step of kneading a hydrogenated bisphenol A 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. manufacturing method.
a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
a step of kneading a hydrogenated bisphenol A type epoxy resin and a silica filler to produce a mixture 3;
A method for producing a sealing material, comprising the step of producing a mixture 4 by kneading the mixture 1, the mixture 3, and a polythiol.
a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
A sealing material comprising a step of kneading a hydrogenated bisphenol A type epoxy resin, a silica filler and a polythiol to produce a mixture 5, and a step of kneading the mixture 1 and the mixture 5 to produce a mixture 6. manufacturing method.
The present invention also provides a method for manufacturing an ink jet recording head, characterized by using the sealing material manufactured by the above manufacturing method.

According to the present invention, there is provided an ink jet recording head sealed with a sealing material having sealing properties, moldability and productivity.

FIG. 1 is a perspective view showing one form of an ink jet recording head. 2A is a partially enlarged view of an ink jet recording head, and FIG. 2B is a sectional view taken along the line AA' shown in FIG. 2A. It is a change in viscosity over time in Examples 15 and 17.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
<Inkjet recording head>
First, the configuration of the ink jet recording head according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of one form of an ink jet recording head according to the present invention. FIG. 2(a) is a partially enlarged view of the ink jet recording head, and FIG. 2(b) is a sectional view of the ink jet recording head taken along line AA' shown in FIG. 2(a).
The inkjet recording head 1 has a substrate 2 and a member 3 that supports the substrate 2 . The substrate 2 has an ejection port 4 for ejecting ink, an energy generating element (not shown) for generating energy for ejecting ink, and an electronic circuit element (not shown) for controlling the energy generating element. there is

The inkjet recording head 1 is a so-called line type head capable of high-speed printing. A line-type head refers to an inkjet recording head having a width equal to or greater than the width of a recording sheet and having a plurality of substrates 2 arranged inline along the width direction. A plurality of substrates 2 are arranged on the inkjet recording head 1 so that recording can be performed on all areas in the width direction of the recording paper by passing the recording paper only once while the inkjet recording head is fixed. are arranged consecutively with a length of Here, the width of the short side of A4 paper is assumed as the width of the recording paper.
A plurality of substrates 2 arranged in-line are accommodated in recesses 3 b provided in the member 3 . A gap is formed between the substrate 2 and the sidewall 3a of the recess 3b of the member 3 when the ink jet recording head 1 is viewed from the side where the ejection ports are open. Also, there may be gaps between the substrates 2 . These gaps are sealed with a sealing material 5 . The sealing material 5 is formed by pouring a sealing material composition into the gap between the substrate 2 and the sidewall 3a of the recess 3b of the member 3 and curing the composition.

<Composition for sealing material>
Next, the composition for sealing materials will be described below. The epoxy resin composition for sealing material used in the present invention contains at least a hydrogenated bisphenol A type epoxy resin, a solid basic compound, and a polythiol.
The above composition is suitable for encapsulation, moldability and productivity so as to form a desired encapsulant. First, the performance of the composition will be described.
Sealability The sealant used in the ink jet recording head is required to have ink resistance against ink contact and wipe resistance against cleaning. The encapsulant used in the present invention is cured by thiol curing (anionic polymerization reaction) with polythiol contained in the composition, and functional groups such as hydroxyl groups that contribute to adhesion remain after curing. In addition, -S- derived from thiol has flexibility and can be expected to have strong adhesion to adherends even in harsh environments. Therefore, it is possible to prevent ink from penetrating from the interface between the adherend and the sealing material. In addition, since epoxy resin is used, excellent mechanical strength can be obtained and wipe resistance can be secured.
・Moldability As shown in FIG. 2, between the substrates 2 arranged inline, it is necessary to pour the sealing material into the recesses 3b with a narrow width of several tens of μm to several mm, so the sealing material has a low viscosity. It is preferred to have The viscosity of the sealing material is preferably 40 Pa·s or less. Further, it is desirable that the sealing material has low elasticity so as not to generate stress in the head member due to temperature rise during the process of mounting the ink jet recording head or during printing by the printer. From this point of view, the elastic modulus of the sealing material is preferably 20 GPa or less, more preferably 10 GPa or less. The sealing material used in the present invention uses a hydrogenated bisphenol A type epoxy resin as the epoxy resin from the viewpoint of low viscosity and low elasticity.
In addition, in the case where the area to be sealed with the sealing material is large, thermal curing at a high temperature may cause deformation of the adherend or breakage of parts due to the difference in linear expansion from the adherend. Therefore, a composition that can be cured at room temperature or at a low temperature of 100° C. or less is effective. Since the reaction rate of anionic polymerization of epoxy resins is generally slow, the reactivity is increased by adding polythiol as a curing agent to the sealing material according to the present invention.
・Productivity Storage stability is required for productivity. It is desirable that the usable time is 8 hours or more at room temperature, but generally the usable time of the one-liquid sealing material is shorter than that of the two-liquid sealing material. The encapsulant of the present invention can obtain a sufficient pot life by containing the hydrogenated bisphenol A type epoxy resin, the solid basic compound, and the polythiol. In order to delay the curing reaction and obtain a more sufficient pot life, as described later, the hydrogenated bisphenol A epoxy resin and the solid basic compound are first mixed, and the resulting mixture is mixed with the polythiol. method is preferred. This is because when the epoxy resin and the solid basic compound are first mixed, the solid basic compound is coated with the epoxy resin. As a result, it takes time for the solid basic compound to dissolve in the polythiol. This is because, as a result, the time until the start of the reaction between the epoxy resin and the polythiol can be delayed. Therefore, even if it is a one-liquid type, the increase in viscosity is slow even at room temperature, and a sufficient pot life can be obtained. The definition of the usable time is the amount of time that can be left at normal temperature, which is twice the value of the viscosity immediately after mixing.

Next, each constituent component of the composition for the encapsulant will be described.
(Epoxy resin)
Epoxy resin is the main agent (hardening component contained most in the composition), and hydrogenated bisphenol A type epoxy resin is used. The hydrogenated bisphenol A type epoxy resin is characterized by not including double bonds and aromatic rings and having a small molecular weight distribution as a structure to reduce elasticity. Further, from the viewpoint of lowering the viscosity, the hydrogenated bisphenol A type epoxy resin is preferably a resin with high purity, and a post-hydrogenated bisphenol A type epoxy resin formed by a post-hydrogenation method is more preferred. Furthermore, from the viewpoint of storage stability, the epoxy resin is preferably an alicyclic epoxy resin. This is because the reactivity of the alicyclic epoxy resin decreases in an anionic polymerization system, and therefore it is effective in extending the pot life. Further, as described above, it is effective for the epoxy resin to be liquid in order to cover the solid basic compound with the hydrogenated bisphenol A type epoxy resin. When an epoxy resin that is solid at room temperature is used, it may be heated to a temperature at which the solid basic compound does not melt to liquefy it, or it may be dissolved in another liquid epoxy resin. Specific epoxy resins include JER YX8000, YX8000D, YX8034, YX8040, etc. as hydrogenated epoxy resin series manufactured by Mitsubishi Chemical Corporation.
One type of hydrogenated bisphenol A type epoxy resin may be used, or two or more types may be contained.

(polythiol)
Polythiol functions as a curing agent. The polythiol is not particularly limited, but usually a highly reactive polythiol with a relatively low molecular weight is selected. As such a polythiol, one that is liquid at room temperature can be preferably used.
Examples include pentaerythritol trispropanethiol (PEPT), trimethylolpropane tris(3-mercaptopropionate) (TMMP), pentaerythritol tetrakis(3-mercaptopropionate), p-xylene dithiol, and the like.
Commercially available products include PEPT (manufactured by SC Organic Chemical Co., Ltd.), TMMP (manufactured by SC Organic Chemical Co., Ltd.), Cupcure 3-800 (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), QX11 (trade name, manufactured by Mitsubishi Chemical Co., Ltd.), and the like. mentioned.
When the encapsulant of the present invention is used in a site that requires higher chemical resistance, a polythiol having an ether skeleton with higher chemical resistance, particularly an ether-type polyfunctional thiol, is preferred. A polythiol with an ether skeleton is an ether bond that has two or more thiol groups in its side chains, does not contain hydrolyzable ester bonds in its main chain, and has excellent properties such as chemical resistance due to its high bonding strength. refers to a compound having Polythiol having an ether skeleton is also effective in reducing viscosity.
The content of the polythiol is preferably such that the thiol equivalent of the polythiol is 0.5 to 1 equivalent with respect to 1 epoxy equivalent of the hydrogenated bisphenol A type epoxy resin. When the equivalent weight of the polythiol to the epoxy resin is 0.5 equivalent or more, the reaction between the epoxy resin and the polythiol occurs at a sufficiently high speed, enabling curing in a short time. Further, when the equivalent weight of the polythiol is 0.5 equivalent or more, the polymerization reaction between the epoxy resin and the polythiol proceeds as the main reaction, and the polymerization reaction between the epoxy resin and the base derived from the solid basic compound hardly occurs as a side reaction. Become. As a result, a polythiol-derived thioether structure (-S-) necessary for obtaining flexibility is sufficiently formed, which is preferable from the viewpoint of adhesiveness. When the equivalent weight of the polythiol to the epoxy resin is 1 equivalent or less, the amount of unreacted polythiol that cannot react with the epoxy resin decreases. In addition, deterioration of mechanical properties such as a decrease in adhesive strength due to unreacted polythiol is suppressed. Moreover, even when a sealant is used in a portion that comes into contact with the ink, the production of unreacted polythiol is suppressed, so the unreacted polythiol does not elute into the ink. For this reason, swelling of the sealing material with ink is suppressed, which is preferable.

(solid basic compound)
A solid basic compound functions as a curing catalyst. The solid basic compound is not particularly limited as long as it is solid at room temperature, but those that are difficult to dissolve in epoxy resins are preferably used.
For example, dicyandiamide generally used as a latent curing agent, dihydrazide compounds, solid aromatic amines such as diaminodiphenylmethane (DDM) and diaminodiphenylsulfone (DDS), various imidazoles, various amine adduct type latent curing agents is mentioned. Amine adduct-based latent curing agents are particularly suitable for curing epoxy resins.
The preferable range of content of the solid basic compound varies depending on the conditions of use.
For example, if the usage conditions require a long pot life, the content of the solid basic compound is preferably 1.5 to 2.5 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. . When the content of the solid basic compound is 1.5 parts by mass or more relative to the epoxy resin, curing can be achieved in a short time. When the content of the solid basic compound is 2.5 parts by mass or less relative to the epoxy resin, the solid basic compound is sufficiently coated with the epoxy resin, and the amount of the solid basic compound eluted into the polythiol is reduced, Sufficient pot life is obtained.
In addition, if the usage conditions require rapid curing at a low temperature of about room temperature, the content of the solid basic compound should be 2.5 to 10 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. is preferred. When the content of the solid basic compound is 2.5 parts by mass or more relative to the epoxy resin, sufficient acceleration of curing can be expected, and when the content of the solid basic compound is 10 parts by mass or less relative to the epoxy resin. If there is, it is an appropriate amount as a non-hardening component.

(Silane agent (silane coupling agent))
A silane agent may be further added to the sealing material according to the present invention. It is preferable to add a low-molecular-weight silane agent to reduce the viscosity. A silane agent having a molecular weight of 500 or less, preferably 300 or less can be used. Also, as the silane agent to be added, a compound having an alicyclic epoxy skeleton, which is characterized by low viscosity, is effective.
Preferred modifying groups of the silane agent include epoxy group, mercapto group, isocyanate group and fluorene skeleton. However, a basic silane coupling agent such as an amine compound is not suitable for use because it acts as a catalyst and immediately initiates the reaction, shortening the pot life.
When the sealant according to the present invention is used in situations where stronger adhesion is required at the interface between the adherend and the sealant, the silane agent preferably has an epoxy group or a mercapto group. In the encapsulant according to the present invention, the main agent is an epoxy resin and the curing agent is polythiol. will be less likely to occur.
The preferred range of the content of the silane agent varies depending on the conditions of use.
For example, under conditions of use that require curability and adhesion, the content of the silane agent is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. When the content of the silane agent is 1 part by mass or more relative to the epoxy resin, the adhesion to the inorganic member can also be improved. can be suppressed.
In addition, if the usage conditions require swelling resistance, pot life, and low viscosity, the content of the silane agent should be 50 to 75 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. is preferred. Compounds containing inorganic components that are difficult to swell, such as silane agents and silica fillers described below, can be expected to improve swelling resistance depending on the amount added. In addition, since the silane agent has fewer reactive groups in one molecule than the epoxy resin, an effect of extending the pot life can be expected. On the other hand, since the reactivity tends to be low, it is preferable to adjust the amount of thiol, which is a curing agent, to achieve both pot life and curability.
Although the mixing order of the silane coupling agents is not particularly limited, it is preferable to mix the epoxy group-containing silane coupling agent with the main epoxy resin and the mercapto group-containing silane coupling agent with the polythiol at the same timing.

(Other additives)
Diluents and other additives may optionally be added to the encapsulant composition containing the above components. For example, addition of a silica filler can be implemented as needed. By adding a silica filler, it is possible to impart swelling resistance and storage stability, which are inherent performances of the silica filler. Further, by adding silica filler, the coefficient of linear expansion can be suppressed, and the deformation of the adherend can be suppressed. As the type of silica filler, general-purpose ones can be used, but for the purpose of suppressing the increase in viscosity, a slightly larger microsilica filler with a particle size of 0.1 μm or more (particle diameter: about 10 μm to 100 nm) or macro silica filler ( Particle diameter: around 100 μm to 10 μm) is preferred. The particle size represents the volume cumulative particle size D50 measured by a laser diffraction/scattering particle size distribution analyzer.
Silane-treated silica filler and the like are also suitable for the purpose of enhancing affinity with other materials.
The content of the silica filler is preferably 100 to 800 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. When the content of the silica filler is 100 parts by mass or more relative to the epoxy resin, the swelling property can be suppressed. Viscosity can be suppressed.
For the purpose of accurately applying the sealing material, a pigment may be added in order to detect the application amount of the sealing material. For pigments, a dispersing agent may be added so as to disperse them well.

Next, the method for producing the encapsulant composition will be described.
(Method for producing composition for sealing material)
In the method for producing a sealing material according to the present invention, each raw material of the sealing material is mixed in the following order for the purpose of suppressing the dissolution of the solid basic compound into the polythiol.
(Encapsulant that does not contain silica filler)
In the method for producing a sealing material according to this embodiment, a sealing material containing no silica filler is manufactured.
The production of a sealing material containing no silica filler can be carried out in the following order of steps.
a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
a step of kneading the mixture 1 and polythiol to produce a mixture 2;
In this production method, it is particularly preferable to produce mixture 2 by kneading mixture 1 and polythiol within 1 hour after production of mixture 1.
According to this production method, compared to the case where each component is kneaded at once without taking the order as described above, the viscosity does not increase easily even when stored at room temperature, and it has a sufficient pot life. Was.
In particular, by kneading the polythiol within 1 hour after the production of the mixture 1, a rapid increase in viscosity can be suppressed and the pot life can be extended.

(Encapsulant containing silica filler)
In the method for manufacturing a sealing material according to this embodiment, a sealing material containing a silica filler is manufactured.
The production of encapsulants containing silica filler has two embodiments. The first embodiment can be implemented in the following order of steps.
a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
a step of kneading a hydrogenated bisphenol A type epoxy resin and a silica filler to produce a first mixture 3;
a step of kneading the mixture 1, the mixture 3 and polythiol to produce a mixture 4;
In this production method, it is particularly preferable to produce the mixture 4 by kneading the mixture 1, the mixture 3 and the polythiol within one hour after the production of the mixture 1. According to this manufacturing method, the encapsulant kneaded in this order had a longer pot life.
In particular, by kneading the polythiol within 1 hour after the production of the mixture 1, a rapid increase in viscosity can be suppressed and the pot life can be extended.

The second embodiment can be implemented in the following order of steps.
a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
A step of kneading a hydrogenated bisphenol A type epoxy resin, a silica filler and a polythiol to produce a mixture 5, and a step of kneading the mixture 1 and the mixture 5 to produce a mixture 6.
In this production method, a hydrogenated bisphenol A epoxy resin, a silica filler, and a polythiol are kneaded to produce a mixture 5 within one hour after the production of the mixture 1, and the mixture 1 and the mixture 5 are kneaded. Preferably mixture 6 is produced by
According to this production method, the silica filler increases the viscosity of the mixture 5, further suppressing contact between the solid basic compound coated with the hydrogenated bisphenol A type epoxy resin and the polythiol. A silane agent may also be added to the mixture 5 . Incidentally, the epoxy resin used in the above mixture can be appropriately adjusted as long as the amount of each mixture is mixed.
In particular, by kneading the polythiol within 1 hour after the production of the mixture 1, a rapid increase in viscosity can be suppressed and the pot life can be extended.

EXAMPLES The embodiments of the present invention will be described in more detail with reference to examples below.
Examples 1-14 and Comparative Examples 1-2
<Preparation of composition for sealing material>
Table 1 shows the materials used in Examples and Comparative Examples, their composition ratios, and evaluation results.
In Examples 1 to 10 and 13 to 14, a mixture A was obtained by kneading a hydrogenated bisphenol A type epoxy resin as a main agent and a solid basic compound as a catalyst. After 12 hours, mixture B obtained by kneading the same epoxy resin and silica filler, polythiol as a curing agent, and silane agent were added and kneaded (mixture A+B+curing agent+silane agent).
In Example 11, the epoxy resin as the main agent and the solid basic compound as the catalyst were kneaded to form a mixture A. After 12 hours, the mixture A, the polythiol, the silica filler, and the silane agent were kneaded to form a mixture C.
In Example 12 and Comparative Examples 1 and 2, all materials were kneaded simultaneously.
The epoxy resin and the thixotropic agent were kneaded in vacuum at 1000 rpm for 2 minutes in HIVIS MIX model 3 manufactured by Primix Co., Ltd., and kneading other than the epoxy resin and thixotropic agent was performed in vacuum at 600 rpm for 5 minutes.

<Method for evaluating sealing material>
Sealing materials formed using the compositions of Examples 1 to 14 and Comparative Examples 1 and 2 were evaluated in the following six ways. Table 1 shows the evaluation results.
Insulating property The compositions of Examples 1 to 14 and Comparative Examples 1 and 2 were placed in a mold and allowed to stand at room temperature for 1 day or longer to cure. The obtained cured product was taken out from the mold and used as a sample for evaluation of the encapsulant. The volume resistivity of the evaluation sample was measured. The volume resistivity was determined according to the test method ISO2951 and an applied voltage of 500V.
• Ink resistance The evaluation sample was immersed in an amount of ink (water: organic solvent: surfactant = 75:25:1) having a mass ratio 20 times that of the evaluation sample, and heated at 105°C for 10 hours. Note that this ink does not contain a coloring material because it is for evaluation purposes. The mass of the evaluation sample before and after heating was measured, and the ink absorbance was determined based on the mass of the evaluation sample before heating.
· Durability The compositions of Examples 1 to 14 and Comparative Examples 1 and 2 were poured into the sealant 5 portion of the ink jet recording head 1 shown in FIG. Then, the composition was allowed to stand for one day or longer to cure. A durability test was performed by rubbing the resulting inkjet recording head with a blade (made of acrylonitrile-butadiene rubber) 1000 times, and the presence or absence of scratches or scrapes on the surface of the sealing material after the durability test was confirmed with an optical microscope.
・ Elastic modulus Using the above evaluation sample, the elastic modulus (E′) and tan δ were measured using a dynamic viscoelasticity measuring device DMS6100 (manufactured by Seiko Instruments Inc.) in a tensile mode, with a sample distance of 15 mm, a measurement frequency of 1 Hz, Measurement was carried out at a heating rate of 2°C/min over a measurement temperature range of 20°C to 120°C.
- Pot life The pot life was calculated as the time until the viscosity became twice the initial viscosity.
Judgment was made as follows.
◎: pot life of 24 hours or more ○: pot life of 8 hours or more and less than 16 hours ×: pot life of less than 8 hours Viscosity Resin compositions prepared in Examples 1 to 18 and Comparative Examples 1 and 2 was measured using a viscometer "TV-20" (manufactured by Toki Sangyo Co., Ltd.).

<Evaluation of sealing material>
(Examples 1 to 4, 8)
In Examples 1 to 4, the main sealing performance and storage stability are excellent, but there is a difference in viscosity. rice field. This is considered to be due to the effect of adding a low-molecular-weight silane agent to the hydrogenated bisphenol A type epoxy resin, which is an alicyclic epoxy. In Example 8, the main sealing performance and storage stability were comparable to those of Examples 1 to 4, but the surface of the molded sample was glossy and superior in flatness compared to other examples. was
(Example 5)
Although the main sealing performance and storage stability are excellent, the viscosity is slightly higher than that of Example 2, and the ink resistance is lowered. This is thought to be due to the use of a thiol having an ester structure.
(Examples 6-7)
The main sealing performance was excellent, but compared with Example 2, there was a difference that ink resistance and storage stability were lowered. This is thought to be due to the use of a thiol having an ester structure.
(Examples 9 and 13)
The main sealing performance was excellent, but compared with Example 2, the storage stability was slightly degraded. This is probably because the increased amount of the solid basic compound improved the reactivity during storage.
(Example 10)
The main sealing performance and storage stability were excellent, but a difference was observed in the viscosity, which was higher than that of Example 2. This is considered to be due to the effect of using the pre-hydrogenated bisphenol A type epoxy resin.
(Example 11)
The main sealing performance and storage stability were excellent, but a difference was observed in the viscosity, which was higher than that of Example 2. This is due to the difference in mixing method, and it is considered that the silica filler is not sufficiently mixed with other materials.
(Example 12)
Although the main sealing performance was excellent, differences were observed in storage stability and viscosity. Example 12 had higher viscosity and lower storage stability than Example 2. This is due to the difference in the mixing method, and is considered to be due to the low mixing degree of the silica filler and the low coverage of the epoxy resin on the solid basic compound.
(Example 14)
The main encapsulation performance was excellent and the initial viscosity was also suppressed. This is believed to be due to the increased amount of silane agent and solid basic compound.
(Comparative Examples 1 and 2)
In Comparative Examples 1 and 2, since the aromatic epoxy resin was used, the sealing performance was inferior to that of Examples 1 to 12, and the result was that the function as a sealing material was not satisfied.

表１中、例えば、実施例１の後水添Bis-Aの欄が「１０ Ａ ９０Ｂ」とあるのは、後水添Bis-Aの配合量が、混合物Ａでは、１０であり、混合物Ｂでは、９０であることを意味し、エポキシアミンアダクトの欄が「２ Ｂ」とあるのは、エポキシアミンアダクトの配合量が、混合物Ｂにおいて２であることを意味する。

In Table 1, for example, "10 A 90B" in the column of post-hydrogenated Bis-A in Example 1 means that the amount of post-hydrogenated Bis-A is 10 in Mixture A and 10 in Mixture B. means 90, and "2 B" in the column for the epoxyamine adduct means that the blending amount of the epoxyamine adduct is 2 in the mixture B.

Examples 15-18
<Preparation of composition for sealing material>
Table 2 shows the materials used in the examples and their composition ratios.
In Examples 15 and 16, a mixture A was obtained by kneading a hydrogenated bisphenol A type epoxy resin as a main agent and a solid basic compound as a catalyst. Within 1 hour, mixture B obtained by kneading the same epoxy resin and silica filler, polythiol as a curing agent, and silane agent were added and kneaded (mixture A + B + curing agent + silane agent).
In Examples 17 and 18, a mixture A was obtained by kneading a hydrogenated bisphenol A type epoxy resin as a main agent and a solid basic compound as a catalyst. After 12 hours, mixture B obtained by kneading the same epoxy resin and silica filler, polythiol as a curing agent, and silane agent were added and kneaded (mixture A+B+curing agent+silane agent).
The epoxy resin and the thixotropic agent were kneaded in vacuum at 1000 rpm for 2 minutes in HIVIS MIX model 3 manufactured by Primix Co., Ltd., and kneading other than the epoxy resin and thixotropic agent was performed in vacuum at 600 rpm for 5 minutes.

<Method for evaluating sealing material>
The encapsulants formed using the compositions of Examples 15-18 were evaluated as follows. Evaluation results are shown in Tables 3 and 4.
- Pot life The pot life was calculated as the time until the viscosity became twice the initial viscosity.
Judgment was made as follows.
○: pot life of 4 hours or more △: pot life of less than 4 hours (manufactured).
・Curing time The curing time was the time required to cure at room temperature.
Judgment was made as follows.
◯: No tackiness after 30 hours at room temperature △: Tackiness after 30 hours at room temperature Reaction rate The reaction rate at room temperature for 30 hours was confirmed by DSC (differential scanning calorimetry).

<Evaluation of sealing material>
(Example 15)
In Example 15, as shown in FIG. 3, compared to Example 17, the increase in viscosity over time was faster, and as shown in Table 3, a high reaction rate was observed after 30 hours at room temperature. This is probably because the reactivity was improved by mixing the polythiol within 1 hour after preparing the mixture A.
(Example 16)
Compared with Example 16, the initial viscosity was suppressed. This is believed to be due to the increased amount of silane agent and solid basic compound.
(Examples 17 and 18)
In Examples 17 and 18, the storage stability is excellent, but the curing time is longer than in Examples 15 and 16.

表２中、例えば、実施例１の後水添Bis-Aの欄が「１０Ａ ９０Ｂ」とあるのは、後水添Bis-Aの配合量が、混合物Ａでは、１０であり、混合物Ｂでは、９０であることを意味し、エポキシアミンアダクトの欄が「１０Ｂ」とあるのは、エポキシアミンアダクトの配合量が、混合物Ｂにおいて１０であることを意味する。

In Table 2, for example, "10A 90B" in the column of post-hydrogenated Bis-A in Example 1 means that the amount of post-hydrogenated Bis-A is 10 in mixture A and 10 in mixture B. , 90, and "10B" in the epoxyamine adduct column means that the epoxyamine adduct loading is 10 in mixture B.

REFERENCE SIGNS LIST 1 inkjet recording head 2 substrate 3 member 3a side wall of concave portion 3b concave portion 4 ejection port 5 sealing material

Claims (25)

An inkjet recording head comprising a substrate having ejection ports for ejecting a liquid and a member provided with a concave portion for accommodating the substrate,
a gap formed between the wall of the recess of the member and the substrate, and a sealing material for sealing the gap;
The inkjet recording head, 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, and a polythiol. 2. The ink jet recording head according to claim 1, wherein the composition has a viscosity of 40 Pa.s or less. 3. An ink jet recording head according to claim 1, wherein said composition contains a silane agent. 4. An ink jet recording head according to claim 3, wherein said silane agent contains an alicyclic epoxy skeleton. 5. An ink jet recording head according to claim 3, wherein the silane agent has a molecular weight of 500 or less. 6. The ink jet recording head according to claim 3, wherein the silane agent has a molecular weight of 300 or less. The inkjet recording according to any one of claims 3 to 6, wherein the content of the silane agent is 1 to 50 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. head. The inkjet recording according to any one of claims 3 to 6, wherein the content of the silane agent is 50 to 75 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. head. 9. The ink jet recording head according to claim 1, wherein the sealing material has an elastic modulus of 20 GPa or less. 10. The ink jet recording head according to any one of claims 1 to 9, wherein the solid basic compound is an amine adduct latent curing agent. 11. The inkjet recording head according to any one of claims 1 to 10, wherein the polythiol is an ether-type polyfunctional thiol. Any one of claims 1 to 11, wherein the content of the polythiol is such that the thiol equivalent of the polythiol is 0.5 to 1 equivalent with respect to 1 epoxy equivalent of the hydrogenated bisphenol A epoxy resin. 2. The ink jet recording head according to item 1 or 2. 13. The ink jet recording head according to any one of claims 1 to 12, wherein the composition contains a silica filler. 14. An ink jet recording head according to claim 13, wherein the silica filler has a particle size of 0.1 [mu]m or more. 15. An ink jet recording head according to claim 13, wherein said silica filler is silane-treated. 16. The content of the solid basic compound is 2.5 to 10 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. The ink jet recording head described. 16. Any one of claims 1 to 15, wherein the content of the solid basic compound is 1.5 to 2.5 parts by mass with respect to 100 parts by mass of the hydrogenated bisphenol A type epoxy resin. The ink jet recording head according to the item. 18. The ink jet recording head of claim 1, wherein the hydrogenated bisphenol A type epoxy resin is a post-hydrogenated bisphenol A type epoxy resin. A sealing material comprising a step of kneading a hydrogenated bisphenol A 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. manufacturing method. 20. The method for producing a sealing material according to claim 19, wherein the mixture 1 and the polythiol are kneaded to produce the mixture 2 within one hour after the production of the mixture 1. a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
a step of kneading a hydrogenated bisphenol A type epoxy resin and a silica filler to produce a mixture 3;
A method for producing a sealing material, comprising the step of producing a mixture 4 by kneading the mixture 1, the mixture 3, and a polythiol. 22. The method for producing a sealing material according to claim 21, wherein the mixture 1, the mixture 3, and the polythiol are kneaded to produce the mixture 4 within one hour after the production of the mixture 1. a step of kneading a hydrogenated bisphenol A type epoxy resin and a solid basic compound to produce a mixture 1;
A sealing material comprising a step of kneading a hydrogenated bisphenol A type epoxy resin, a silica filler and a polythiol to produce a mixture 5, and a step of kneading the mixture 1 and the mixture 5 to produce a mixture 6. manufacturing method. Within 1 hour after the preparation of the mixture 1, the hydrogenated bisphenol A epoxy resin, the silica filler and the polythiol are kneaded to prepare the mixture 5, and the mixture 1 and the mixture 5 are kneaded to prepare the mixture 6. 24. The method for producing a sealing material according to claim 23, characterized in that: 25. A method for manufacturing an ink jet recording head, comprising using the sealing material manufactured by the manufacturing method according to any one of claims 19 to 24.

Images