JP2002155129A - Epoxy resin composition and method of producing ink jet head by using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition having excellent adhesiveness and effective particularly in joining constituent members of an ink jet head. SOLUTION: The epoxy resin composition contains at least a liquid epoxy resin and a liquid curing agent, and is solventless. An example of the liquid epoxy resin preferably used comprises one containing at least a bisphenol epoxy resin. In an example, a bisphenol A epoxy resin and 2-ethyl-4-methylimidazole are mixed under stirring to prepare an epoxy resin composition, this composition is used to bond an Ni plate to an Si wafer, and the bond strength and ink resistance of the joined material are tested to give excellent results. The epoxy resin composition of this invention is very useful as an adhesive for bonding the constituent members of an ink jet head to each other, for example, for bonding a static actuator 401 to a nozzle plate 404.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an epoxy resin composition and a method for manufacturing an ink jet head using the same.

[0002]

2. Description of the Related Art An ink jet recording system has many features, such as that a recording material can be directly recorded on recording paper without contact, and that the process is very simple. Further, the ink jet recording method has attracted much attention as a color recording method. Various methods have been proposed for such an ink jet recording method, but the commercialization is rapidly progressing due to Drop On.
Demand (DOD) method.

The DOD method is a method in which ink is ejected only when a recording signal is input, and has the simplest structure. There are also two types of DOD methods, a bubble jet (registered trademark) method and a piezo actuator method. The former bubble jet method has been proposed in Japanese Patent Publication No. 61-59913. This method utilizes bubbles generated by thermal energy, and a heater corresponding to an actuator is provided in an ink flow path. That is, this method is a method in which bubbles are generated on the surface of the heater by directly instantaneously heating the ink, and the droplet ink is caused to fly by an increase in the ink pressure in the flow path at this time.

A proposal of a piezo actuator system which is another ink jet recording system is disclosed in Japanese Patent Publication No. 60-89.
No. 53, for example. This system is characterized in that a piezo element, which is an actuator, is provided outside the ink flow path, in contrast to the configuration of the bubble jet system. The outline of the operation of the piezo element system is as follows. A part of the wall surface of the pressurized liquid chamber has a deformable structure, and the piezo element provided outside the wall surface is displaced by an applied voltage, so that the ink inside the pressurized liquid chamber is displaced. And ejects the ink through a nozzle. At this time, the pressure is increased by a pulse-like increase. After the ink is ejected, the displacement of the piezo element is returned to the original position, so that the ink is supplied from the ink tank side into the pressurized chamber. The feature of this method is that the piezo element does not directly contact the ink, so the selection of the piezo element member is not restricted by the suitability for ink, and by implementing the efficient design of the piezo element,
The advantage is that heat generation of the piezo element can be suppressed, and there is no restriction on the heat resistance of the ink used.

Further, as an actuator having a microstructure formed using a semiconductor microfabrication technique, an actuator utilizing electrostatic force as a driving source is known. For example, JP-A-5-50601 and JP-A-6-71882 disclose electrostatic ink jet heads that discharge ink droplets by using electrostatic force. In an ink jet head of this type, a bottom surface of an ink flow path communicating with a nozzle is formed as an elastically deformable vibration plate, and a substrate is disposed at a predetermined interval on the vibration plate. And a counter electrode is arranged in each of the two. When a voltage is applied between the opposing electrodes, the vibrating plate is electrostatically attracted to the substrate side and vibrates due to the electrostatic force generated between them. Ink droplets are ejected from the nozzles by fluctuations in the internal pressure of the ink flow path caused by the vibration of the diaphragm.

In an ink jet head using such an ink jet recording method, regardless of the bubble jet method, the piezo actuator method, or the electrostatic method,
Since the flow path portion and the liquid chamber portion through which the ink passes are always immersed in the weakly alkaline ink, the reliability of the materials constituting them, between the members of the material itself, and the bonding between the material and the substrate is reduced. Very important. Therefore, the material for bonding the flow path portion and the liquid chamber portion is first required to have the above-described ink resistance, and further is required to have adhesive strength, workability, and the like.

Until now, various methods have been studied for bonding these members, corresponding to each ink jet head. Actually, thermocompression bonding with a thermoplastic resin such as a dry film or a photosensitive adhesive (Japanese Patent Laid-Open No.
JP-A-314675), a solvent-dilutable adhesive is applied, and then the solvent is volatilized to adhere as a high-viscosity adhesive (Japanese Patent Laid-Open Publication No. 7-314797), or a two-component adhesive composed of a main agent and a curing agent. Are separately applied to a member (substrate), and after lamination and curing, solvent washing or the like (Japanese Patent Application Laid-Open No. 10-2358)
No. 75) or using an adhesive which is cured by light including ultraviolet light (JP-A-6-143568, JP-A-5-15).
No. 5017), various bonding methods are being studied. However, as a matter of fact, at present, various required specifications cannot be sufficiently satisfied.

For example, metals, resin plates, Si substrates, photosensitive resins, and the like have been used as materials for the flow passages and liquid chambers. Among these materials,
The photosensitive resin is widely used as a material for the flow path section and the liquid chamber section because an ink flow path having a desired shape can be easily obtained by a photolithography process. Examples of such a photosensitive resin include those that have been used for forming patterns on printing plates, printed wiring, and the like, or those that are known as photocurable paints and adhesives used for glass, metal, ceramics, and the like. Although used, a dry film type photosensitive resin film (DFR) has been mainly used in terms of work efficiency and the like.

However, in such a DFR, since the main component is an acrylic resin, ink resistance,
In particular, there is a problem that the alkali resistance and the adhesion to the substrate are not perfect after long-term ink immersion. This is due to the fact that the ink itself is weakly alkaline in order to improve the solubility of the dye, whereby the acrylic resin having a relatively low degree of crosslinking swells or the remaining unreacted components are dissolved. I have.

[0010] Further, in solvent-evaporated high-viscosity bonding, the adhesive composition is originally a high-viscosity adhesive, and it is difficult to uniformly form a coating film after the solvent is volatilized. There are problems such as non-uniform adhesion and generation of voids in the coating during volatilization. Further, the method of applying the main agent and the curing agent to the respective adherend surfaces with the two-component adhesive has a problem that the pot life is long but the workability is poor. Further, in the case of UV-curable adhesives, insufficiently cured portions are apt to be formed in portions not irradiated with UV light, and cannot be used as such as adhesives. In addition, a large amount of unreacted monomer may remain in the cured product, causing a problem in ink resistance, and a decrease in adhesive strength. In some cases, an elastic silicone adhesive is used to enhance the adhesiveness. However, such an elastic silicone adhesive has a disadvantage that it is weak to alkalis and solvents and swells.

[0011]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has an excellent adhesive function, and is particularly useful for an epoxy resin which is effective for joining components of an ink jet head. An object of the present invention is to provide a composition and a method for manufacturing an ink jet head using the composition. In particular, an object of the present invention is to improve the ink resistance of an adhesive for bonding members constituting an ink flow path portion and a liquid chamber portion of an ink jet head, particularly alkali resistance, and to improve adhesion between members after long-term immersion, An object of the present invention is to provide an epoxy resin composition for producing an inkjet head having high peel strength and good workability, and a method for producing an inkjet head using the same as an adhesive.

[0012]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that at least a liquid epoxy resin and a liquid curing agent are contained, and that the composition is solvent-free, so that the curability is improved and the resistance to the resin is improved. The present invention has found an epoxy resin composition which improves ink properties, enhances adhesion between members, improves adhesive strength, has good workability, and is particularly useful for the production of ink jet heads. . The epoxy resin has a smaller cure shrinkage than other adhesive base materials, and is effective for fine bonding.

The epoxy resin composition according to the first aspect is characterized in that it contains at least a liquid epoxy resin and a liquid curing agent and is solvent-free.

An epoxy resin composition according to a second aspect is characterized in that, in the first aspect, the liquid epoxy resin contains at least a bisphenol-based epoxy resin. The epoxy resin composition according to a third aspect is characterized in that, in the first aspect, the liquid epoxy resin contains at least a flexible epoxy resin. The epoxy resin composition according to a fourth aspect is characterized in that, in the first aspect, the liquid epoxy resin contains at least a glycidylamine-based epoxy resin. The epoxy resin composition according to a fifth aspect is characterized in that, in the first aspect, the liquid epoxy resin contains at least a fluorinated epoxy resin.

According to a sixth aspect of the present invention, there is provided an epoxy resin composition according to the first aspect, wherein the liquid curing agent has a function of imparting at least flexibility to the cured product. Claim 7
The epoxy resin composition according to claim 6, wherein the liquid curing agent is any one of a polyamideamine-based curing agent, a polyoxyalkyleneamine-based curing agent, and a heterocyclic amine-based curing agent.

The epoxy resin composition according to claim 8 is characterized in that, in claim 1, at least an inorganic filler is blended as a filler, and the epoxy resin composition according to claim 9 is according to claim 1. Wherein at least polymer particles are blended as a filler.

[0017] The epoxy resin composition according to claim 10 is
The epoxy resin composition according to any one of claims 1 to 9, wherein a curing accelerator is blended, and the epoxy resin composition according to any one of claims 1 to 10 is an epoxy resin reactive diluent. Is added.

According to a twelfth aspect of the invention, there is provided a method of manufacturing an ink jet head, wherein constituent members of an ink jet head are bonded to each other using the epoxy resin composition according to any one of the first to eleventh aspects. According to a thirteenth aspect of the invention, there is provided a method of manufacturing an ink jet head, wherein the constituent members of the ink jet head are bonded by curing an epoxy resin composition at room temperature. According to a fourteenth aspect of the present invention, in the twelfth aspect, the constituent members of the inkjet head are firstly cured at room temperature or lower than the epoxy resin composition, and then after-cured and bonded. It is characterized by the following.

Further, in the method of manufacturing an ink jet head according to the present invention, the nozzle plate made of a Ni-iron alloy and the head body made of silicon are provided.
It is characterized in that it is bonded by the bonding method according to any one of 2 to 14.

According to the first aspect of the present invention, an epoxy resin composition having an extremely excellent adhesive effect can be provided. For this reason, for example, the components of the inkjet head are uniformly bonded to each other, the curability is improved, the ink resistance is improved,
Adhesion between members can be enhanced, peel strength can be improved, and an ink jet head with good workability can be provided.

According to the second aspect of the present invention, by containing at least a bisphenol-based epoxy resin as the liquid epoxy resin, it is particularly useful for manufacturing an ink jet head having improved ink resistance and improved adhesion between members. It is possible to provide a simple epoxy resin composition. Claim 3
In the invention of the invention, by containing at least a flexible epoxy resin as a liquid epoxy resin, to increase the peel strength,
An epoxy resin composition particularly useful for producing an ink jet head having good ink resistance can be provided. According to the invention of claim 4, the pot life can be adjusted by containing at least a glycidylamine-based epoxy resin as the liquid epoxy resin, and an epoxy resin particularly useful for manufacturing an ink jet head having good workability. A composition can be provided. Further, in the invention of claim 5, by providing at least a fluorinated epoxy resin as a liquid epoxy resin, an epoxy resin composition which is particularly useful for producing an ink jet head having improved peel strength and improved ink resistance is provided. can do.

According to the sixth aspect of the present invention, an epoxy resin composition which is particularly useful for producing an ink jet head having improved peel strength is obtained by using a curing agent which imparts at least flexibility to a cured product as a liquid curing agent. Provided. Also,
In the invention of claim 7, since the liquid curing agent is any of a polyamideamine-based curing agent, a polyoxyalkyleneamine-based curing agent, and a heterocyclic amine-based curing agent, the peel strength is improved and the ink resistance is good. The present invention can provide an epoxy resin composition which is particularly useful for producing a simple inkjet head.

In the invention of claim 8, since at least an inorganic filler is blended as a filler, the viscosity can be adjusted.
It is possible to provide an epoxy resin composition which has good workability and prevents bleeding at the time of curing and bonding, and which is particularly excellent for inkjet head production. According to the ninth aspect of the present invention, since at least the polymer particles are blended as the filler, the viscosity can be adjusted and the workability is good.
It is possible to provide an epoxy resin composition which prevents oozing at the time of curing and bonding, further imparts flexibility, and has excellent peel strength, which is particularly excellent for inkjet head production.

According to the tenth aspect of the present invention, by adding a curing accelerator, curability is improved, and ink resistance is improved.
It is possible to provide an epoxy resin composition which is more excellent for manufacturing an ink jet head and which further improves peel strength. According to the eleventh aspect of the present invention, by adding an epoxy resin reactive diluent, the viscosity can be adjusted, the workability is good, and an epoxy resin composition particularly excellent for manufacturing an ink jet head can be provided. .

According to a twelfth aspect of the invention, there is provided a method for manufacturing an ink jet head, wherein the constituent members of the ink jet head are bonded to each other by using the epoxy resin composition according to any one of the first to eleventh aspects. The components of the inkjet head are uniformly adhered to each other to enhance curability, improve ink resistance, enhance adhesion between members, and improve peel strength, thereby producing an inkjet head having good workability. can do.

According to a thirteenth aspect of the present invention, in the twelfth aspect, the components of the ink jet head are bonded to each other by curing the epoxy resin composition at room temperature to thereby form a heat-curing adhesive. It is possible to manufacture an ink jet head in which stress is reduced and adhesion distortion of a liquid chamber, a nozzle plate, and the like is reduced.

Further, in the method of manufacturing an ink jet head according to the present invention, the constituent members of the ink jet head are first cured at room temperature or at a lower temperature than the epoxy resin composition, and then after-cured and bonded. Therefore, it is possible to manufacture an ink jet head having improved curability, improved ink resistance, and further improved peel strength.

Further, in the method of manufacturing an ink jet head according to the fifteenth aspect, the nozzle plate made of a Ni-iron alloy and the head body made of silicon are bonded by the bonding method. It is possible to manufacture an ink jet head which has small distortion and can reduce stress applied to the ink jet head main body.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The liquid epoxy resin used in the present invention may be any liquid in general, such as bisphenol A type epoxy resin, alkyl substituted bisphenol A type epoxy resin, bisphenol F type epoxy resin, alkyl substituted bisphenol F type epoxy resin, Bisphenol S type epoxy resin, hydrogenated bisphenol A type epoxy resin,
Glycidylamine type epoxy resin, phenol novolak type epoxy resin, glycidyl ester type epoxy resin, alicyclic epoxy resin, urethane modified epoxy resin,
Examples include a polysulfide-modified epoxy resin, a rubber-modified epoxy resin, and a polyalkylene glycol-type epoxy resin. It is not particularly limited to these. These may be used alone or as a mixture.

The curing agent may be a liquid curing agent,
For example, an aromatic amine-based curing agent, an aliphatic amine-based curing agent,
Examples include alicyclic amine-based curing agents, epoxy-modified adductamine-based curing agents, polyoxyalkyleneamine-based curing agents, heterocyclic amine-based curing agents, trifunctional thiol-based curing agents, and imidazole-based curing agents. However, the present invention is not limited to this. These may be used alone or as a mixture. The use of such a liquid epoxy resin does not require the use of a solvent, does not generate voids or the like in the coating film, gives a low-viscosity composition, and is effective for uniform adhesion.

In particular, when a bisphenol-based epoxy resin is used, it is liquid and has good mixing with a curing agent, and has high reactivity, so that it has good curability, and the cured product has good ink resistance and good adhesion. Strength becomes good. Specifically, bisphenol A type epoxy resin, bisphenol F
The cured product of the mold epoxy resin has good curability, good ink resistance, and good adhesive strength.

Examples of the flexible epoxy resin include urethane-modified epoxy resin, polysulfide-modified epoxy resin, rubber-modified epoxy resin (modified with CTBN, ATBN, etc.), polyalkylene glycol type epoxy resin, bisphenol A type epoxy resin with ether elastomer, Examples thereof include a liquid urethane resin-added bisphenol A type epoxy resin, but are not limited thereto. These may be used alone or in combination.
Further, it may be used by mixing with a bisphenol-based epoxy resin.

When a flexible epoxy resin is used, the cured product is more flexible than the other epoxy resins, so that the adhesive strength is increased. Furthermore, the polysulfide-modified epoxy resin and the polyalkylene glycol type epoxy resin have slightly lower curability than bisphenol-based epoxy resins, but can prolong the pot life and improve workability.

Among the flexible epoxy resins, a bisphenol A type epoxy resin, in particular, an ether elastomer added to a flexible epoxy resin added to a liquid urethane resin has a very high peeling strength, a high curability and a high ink resistance. It has good properties and is suitable as an epoxy resin of an inkjet head epoxy resin composition.

Glycidylamine epoxy resins include N, N, N ', N'-tetraglycidyl-m-
Xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-glycidyl-o-toluidine, and the like, but not limited thereto. Absent. These may be used alone or as a mixture, or may be used as a mixture with a bisphenol-based epoxy resin.

When a glycidylamine-based epoxy resin is used, particularly in the case of a combination with an amine-based curing agent, the curing reaction speed becomes slow, the pot life becomes long, and the workability in the process becomes good. In addition, the improved crosslink density has an effect on ink resistance, particularly on swelling with ink (claim 4).

As the fluorinated epoxy resin, bisphenol hexafluoroisopropyl glycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy) -1-trifluoromethyl-2,2,2-trifluoroethyl) Benzene, 1,4-bis (1- (2,3-
Epoxypropoxy) -1-trifluoromethyl-2,
2,2-trifluoromethyl) benzene, 4,4-bis (2,3-epoxypropoxy) octafluorobiphenyl, bis (1,1,1,3,3,3-hexafluoropropyl) diglycidyl ether, And a fluorinated epoxy resin represented by the following formula (1), but are not limited thereto. These can be used alone,
They may be used as a mixture, or may be used as a mixture with a bisphenol-based epoxy resin.

[0038]

Embedded image

Bisphenol hexafluoroisopropyl glycidyl ether, which is a fluorinated epoxy resin,
When a bisphenol-based epoxy resin is used as a mixture, the cured product in particular wets the adherend with a low surface tension, so that the adhesive strength is improved. Further, the fluorine content of the fluorinated epoxy resin composition represented by the above general formula is 25 wt% or more, and becomes a cured product in which a fluorine element is introduced, which is effective in improving ink resistance (Claim 5).

As a curing agent for imparting flexibility to the cured product, a polyamideamine-based curing agent, a polyoxyalkyleneamine-based curing agent, a heterocyclic amine-based curing agent, a trifunctional thiol-based curing agent (THEIC-BMPA, etc.) ), Aliphatic amines (eg, methylpentanediamine), etc., as long as they impart flexibility to the cured product and lower the crosslink density of the cured product. These may be used alone or as a mixture, and may be used as a mixture with another amine-based curing agent such as an aromatic amine or an alicyclic amine.

When a curing agent for imparting flexibility is used,
The epoxy resin may be any of the above-described epoxy resins, and preferably, a bisphenol-based epoxy resin or a flexible epoxy resin further improves the adhesive strength.
In particular, when combined with a bisphenol A-type epoxy resin added with an ether elastomer or a bisphenol A-type epoxy resin added with a liquid urethane resin, the adhesive strength and the ink resistance are improved. In addition, since the cured product is given a soft cured product even when imparting flexibility with a curing agent, and a cured product having a lower crosslink density is provided, the adhesive strength is improved (claim 6).

Curing agents that further provide flexibility include polyamideamine-based curing agents (Fuji Kasei: Tomide, Henkel Japan: Versamide, etc.), polyoxyalkyleneamine-based curing agents (HUNTSMAN: Jeffamine, etc.), and heterocyclic amine-based curing agents. In the case of a curing agent (oiled shell epoxy: epomate or the like), the curability is particularly good, the peel strength is improved, and the ink resistance is good. In addition, polyoxyalkyleneamine polyoxypropylene diamine and polyoxypropylene triamine have a methyl group, which can be steric hindrance, suppress the reactivity, extend the pot life, and improve the workability of mixing and coating. Can be improved (claim 7).

In order to improve the curability, it is preferable to add these curing agents in excess of the epoxy equivalent used. Conversely, flexibility can be achieved by adding an epoxy resin in excess of the curing agent equivalent.

Examples of the inorganic filler include carbonates such as calcium carbonate and magnesium carbonate, sulfates such as barium sulfate and magnesium sulfate, silicates such as aluminum silicate and zirconium silicate, iron oxide, titanium oxide, and the like. Examples include oxides such as aluminum oxide and zinc oxide, kaolin, talc, asbestos powder, quartz powder, mica, glass fiber, and the like, but are not limited thereto. Among these, it is preferable to use one or more of titanium oxide and silica from various points. The particle size of these inorganic fillers is preferably smaller, and the particle size is particularly preferably 1 μm or less, and the primary particles are preferably about 30 nm or less. When the particle size exceeds 1 μm, it becomes difficult to apply and bond the fine coating, and the effect of preventing the exudation at the time of curing and bonding is reduced. When the inorganic filler is mixed, the viscosity of the epoxy resin composition can be easily adjusted, and it can correspond to various application viscosities. Further, the addition of an inorganic filler improves the ink resistance of the cured product.

The amount of these fillers varies greatly depending on the epoxy resin composition of the present invention and especially on the type of the filler.
It is desirably within the weight part. Further, from the viewpoint of the ink resistance of the cured product, the content is preferably within this range. However, if it exceeds 100 parts by weight, the applicability of the epoxy resin composition is impaired due to an increase in viscosity. In addition, the adhesiveness tends to deteriorate. In addition, when mixing the filler, it is desirable to knead the mixture with a three-roll or the like in order to uniformly disperse the filler, and to use the mixture after making it fine (claim 8).

When using an inorganic filler, it is desirable to use a silane coupling agent, a titanium coupling agent and the like. Specifically, as the silane coupling agent, for example, γ-aminopropyltriethoxysilane,
N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane , N
-Phenyl-γ-aminopropyltrimethoxysilane,
aminosilane coupling agents such as γ-ureidopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ Epoxy silane coupling agents such as glycidoxypropylmethyldiethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β
-Methoxyethoxy) silane and other vinyl silane coupling agents, γ-mercaptopropyltrimethoxysilane and other mercaptosilane coupling agents, γ-methacryloyloxypropyltrimethoxysilane and other acrylic silane coupling agents, methyltrimethoxysilane, methyltrimethylsilane General formulas such as ethoxysilane, γ-chloropropyltrimethoxysilane, trifluoromethyltrimethoxysilane, etc. RSi (OR ′) ₃ [wherein R may be substituted by one or more halogen atoms; A linear or branched alkyl group having about 1 to 4 carbon atoms is shown, and R 'is a linear or branched alkyl group having about 1 to 4 carbon atoms. ]
And the like. Note that the present invention is not particularly limited to these.

Specific examples of the titanium coupling agent include:
For example, isopropyl triisostearoyl titanate, isopropyl tris-isodecyl benzene sulfonyl titanate, isopropyl tris-n-decyl benzene sulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl-bis (dioctyl phosphite) titanate, tetraoctyl- Bis (ditridecyl phosphite) titanate, tetra (2,2-diallyloxymethyl-1-butyl) -bis (di-tridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) )
Ethylene titanate, isopropyltrioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N-aminoethyl aminoethyl) titanate, Dicumylphenyloxyacetate titanate, diisostearoylethylene titanate and the like can be mentioned. Note that the present invention is not particularly limited to these.

The amount of the coupling agent varies greatly depending on the epoxy resin composition of the present invention, but the total amount of the epoxy resin composition to which the inorganic filler is added is 100%.
In terms of parts by weight, the amount is preferably 5 parts by weight or less. If the amount exceeds 5 parts by weight, the cohesive strength of the resin decreases, and as a result, the adhesive strength and the reliability decrease (claim 8).

Examples of the polymer particles include, for example, polyethylene particles, polypropylene particles, crosslinked polymethylmethacrylate particles, crosslinked polystyrene particles, melamine resin particles, benzoguanamine resin particles, melamine-guanamine resin particles, polyurethane resin particles, and phenol resin. Particles, epoxy resin particles and the like. It is not particularly limited to these. By using polymer particles, it is possible to prevent seepage during curing and bonding,
Further, flexibility can be given to the cured product, and the adhesive strength is improved.

In particular, in the case of crosslinked polyacrylate particles, when the epoxy resin is cured, not only does the epoxy resin having increased fluidity gel, which contributes to prevention of exudation,
Flexibility can also be imparted to the cured product, which has the effect of increasing the adhesive strength. The viscosity of the epoxy resin composition can also be arbitrarily adjusted by adjusting the mixing amount, thereby improving workability such as a coating process. Further, for unknown reasons, the addition of the crosslinked polyacrylate-based particles also has the effect of accelerating the curing of the epoxy resin, and enables lower-temperature curing adhesion as compared with the case where no mixing is performed. The particle size of these polymer particles is preferably small, and particularly preferably 1 μm or less. When the particle size is 1 μm or more, it becomes difficult to apply and bond the fine particles, and furthermore, the effect of preventing the exudation at the time of curing and bonding decreases, and the bonding strength also decreases.

The mixing amount of the polymer particles is preferably 40 parts by weight or less based on 100 parts by weight of the epoxy resin from the viewpoint of preventing seepage. If it exceeds 40 parts by weight, the applicability of the epoxy resin composition is impaired due to an increase in viscosity. In addition, ink resistance tends to deteriorate. When the filler is mixed, it is preferable to knead the mixture with a three-roll mill or the like in order to uniformly disperse the filler, and to use the mixture after making it fine (claim 9).

The curing accelerator is preferably in the form of a liquid, and includes, for example, tertiary amine compounds, alcohols and phenols, but is not limited thereto. The tertiary amine compound is 2
-Ethyl-4-methylimidazole, 1-benzyl-2
-Methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-cyanoethyl-2-ethyl-4-methylimidazole, N, N'-dimethylpiperazine, benzyldimethylamine, 2- (dimethylaminomethyl) phenol , 2,4,6-tris (dimethylaminomethyl) phenol and the like. Examples of the alcohols and phenols include benzyl alcohol, furfuryl alcohol, and nonylphenol.

In particular, in consideration of ink resistance, a tertiary amine compound which also reacts with the curing accelerator itself and becomes a cured product is preferable. In addition, by using a curing accelerator, curability is improved and adhesive strength is improved. Further, the curing temperature is lowered, and distortion due to low-temperature curing can be suppressed. From these effects, it is possible to contribute to simplification of the ink jet head manufacturing process (energy saving during cell manufacturing) and cost reduction (claim 10).

The amount of the curing accelerator is preferably 10 parts by weight or less based on 100 parts by weight of the epoxy resin. If this amount is 10
When the amount is more than 10 parts by weight, the curability is good, but in the case of a tertiary amine compound, the crosslink density of the cured product is increased, a hard cured product is provided, and the adhesive strength is reduced (claim 10).

As the epoxy resin-reactive diluent, any low-viscosity epoxy-reactive diluent can be used. For example, n-butyl glycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl oxide Glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, glycidyl methacrylate, diglycidyl ether, butanediol diglycidyl ether, diglycidyl aniline, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether and the like. However, the present invention is not limited to these. These may be used alone or as a mixture. In particular, the reactive group is preferably bifunctional or more, and examples thereof include diglycidyl ether, butanediol diglycidyl ether, diglycidylaniline, trimethylolpropane triglycidyl ether, and glycerin triglycidyl ether. These may be used alone or as a mixture.

By adding a reactive diluent, the viscosity of the epoxy resin composition can be easily adjusted, and it is possible to cope with various coating steps. A bifunctional or more functional group is more preferable because the crosslinking density of the cured product can be improved by a curing reaction and the ink resistance can be improved. Further, for unknown reasons, when these reactive diluents are added to the epoxy resin composition and used, the pot life tends to be longer, and the workability can be improved.

The amount of the reactive diluent is 100
It is preferably at most 30 parts by weight based on parts by weight. This amount is 3
If the amount exceeds 0 parts by weight, the properties of the cured product of the base epoxy resin composition will change, but the adhesive strength will be reduced and the ink resistance will be reduced, although there is a dilution effect (claim 11).

The epoxy resin composition of the present invention can be used in any of a bubble jet system, a piezo actuator system, and an electrostatic system, and can be used for bonding members in an ink jet head. In particular, it is effective for bonding members in contact with the ink.

Next, a method for manufacturing an ink jet head using the epoxy resin composition of the present invention will be described. Here, a method of manufacturing an electrostatic inkjet head using an epoxy resin composition will be described, but the invention is not limited to this method.

An Si substrate is prepared, and an electrode portion and a gap portion are formed thereon. Next, another Si substrate is prepared, which is directly bonded to the Si substrate (electrode substrate) on which the electrode portion and the gap portion are formed, and polished to a thickness of 100 μm. Instead of Si / Si direct bonding, the epoxy resin composition of the present invention can be used for curing and bonding.

Next, a nitride film serving as an etching mask is deposited on the bonded wafer, ie, the electrode substrate and the Si substrate, and a back surface channel portion and a liquid chamber portion are formed by wet etching. Next, the bonded wafer is cut by dicing to divide it into a number of chips. After that, the electrode take-out part is opened in each chip by dry etching,
An electrostatic actuator is configured by electrically connecting an FPC cable to the exposed individual electrodes with an anisotropic conductive film. Note that a driver IC is mounted on the FPC cable in advance by wire bonding.
Next, an epoxy resin composition is applied to the upper surface of the liquid chamber (silicon liquid chamber) in order to bond the electrostatic actuator to the nozzle plate formed by Ni electroforming. Further, an epoxy resin composition is applied to seal the gap (the entrance of the vibration chamber) of the vibration plate of the electrostatic actuator. Thereafter, the nozzle plate and the electrostatic actuator coated with the epoxy resin composition are aligned, pressurized and cured by heating to produce an electrostatic inkjet head (see FIGS. 1 and 2 described later). ).

An electrostatic ink jet head is manufactured by such a manufacturing method.
This will be described in more detail.

First, the curing adhesion temperature of the epoxy resin composition may be a temperature at which the epoxy resin composition cures, that is, a temperature at which the cured product has good ink resistance and adhesive strength. Curing conditions are as follows.
Minutes to 7 days, and a range from room temperature to 120 ° C. for 60 minutes to 2 days is preferable. Step curing may be performed. For example, it is also possible to perform multi-stage curing bonding, such as pressure-setting temporary curing at 60 ° C., pressure-free, and main curing at 120 ° C.

In the case of bonding between different kinds of members, for example, when the nozzle plate is formed by Ni electroforming, when the members are heated and bonded to the Si substrate, the respective members have different coefficients of linear expansion. If the temperature is too high, warpage occurs and the actuator may be broken by internal stress. Therefore, it is preferable that the curing adhesion temperature is lower, and room temperature curing adhesion is particularly preferable. Further, the curing time varies depending on the curing temperature and the epoxy resin composition, and is determined according to the respective curing conditions (claims 12 and 13).

The pot life is preferably one hour or more after mixing the main agent and the curing agent in terms of workability and cost. Further, if the mixture is quickly frozen after the mixing, the curing reaction is stopped, and the mixture is stored, the pot life can be further extended.

Although primary curing is sufficient, after-curing after ordinary-temperature curing or low-temperature curing (primary curing) can improve curability and crosslink density, and thus ink resistance and adhesiveness. The after-curing temperature may be within a curing temperature range of a usual epoxy resin composition. In addition, 1
By performing the secondary curing bonding at room temperature and low temperature, in the case of bonding different kinds of members having different linear expansion coefficients, the occurrence of warpage is suppressed even when the after cure is at a high temperature, and there is no problem. The after-curing time varies depending on the curing temperature and the epoxy resin composition, but is preferably the standard curing temperature and time for this composition. According to such an after cure, there is an effect that moisture and an organic substance to be adhered are aged, and a pre-treatment before ink injection is performed (claim 14).

The adhesive pressure of each member at the time of curing adhesion is as follows:
Depending on the viscosity of the epoxy resin composition, 0.5 to
10 kgf / cm ² (4.9 × 10 ⁴ Pa to 9.8 × 1
0 ⁵ Pa). 0.5kgf / cm ²
When pressure bonding is performed at a lower pressure, it becomes difficult to control the thickness of the bonding layer, which causes uneven bonding and lowers the bonding strength. Further, if it exceeds 10 kgf / cm ² , the epoxy resin composition flows during heat curing bonding,
Since the epoxy resin composition flows out from the bonding surface and the epoxy resin composition hardly remains between the members, the bonding strength is reduced, and furthermore, there is a possibility that the ink bleeds out at a portion in contact with the ink flow path, which is preferable. Absent.

The method of applying the epoxy resin composition will be described in detail. Although it differs depending on each part and member, any commonly used uniform application method may be used, and examples thereof include a screen printing method, a spin coating method, and a transfer method. However, the present invention is not limited to these.

Further, the coating thickness of the epoxy resin composition is as follows:
It is sufficient that the adhesion of each member and the performance of the inkjet head are not affected.For example, in the case of adhesion between the nozzle plate and the liquid chamber of the electrostatic inkjet head,
Since the exudation of the epoxy resin composition affects the jetting characteristics, it is necessary to set the coating thickness to about 1 μm. In addition,
When applying on the upper surface of the liquid chamber, the thickness of the applied film is controlled by a transfer method. That is, the epoxy resin composition is thinned and applied to a roller with a doctor blade, and the epoxy resin composition is transferred from the roller with a transfer pad,
Further, the method is performed by transferring the epoxy resin composition from the transfer pad to the upper surface of the liquid chamber.

When a nozzle plate formed of Ni electroforming or SUS is heat-cured and bonded, warpage occurs due to a difference in linear expansion coefficient, and the actuator may be broken by internal stress. Therefore, by using a member having the same linear expansion coefficient of the nozzle plate, the occurrence of warpage can be suppressed, and the curing temperature can be made more flexible. That is, the curing temperature can be increased, and the ink resistance and the adhesive strength can be further improved.

This is made possible by using a Ni-iron alloy as the material of the nozzle plate. The Ni content for making the linear expansion coefficient of this nozzle plate equal to that of the Si substrate as the bonding partner is 30 to 50%, particularly preferably 32 to 40%. In addition, since the linear expansion coefficient becomes equal to that of Ni alone outside this range, there is no point in using a Ni-iron alloy. The curing agent is not limited to the two-pack type, and it is also possible to select a latent curing agent,
It can contribute to improvement of pot life, improvement of workability, cost reduction, and the like (claim 15).

[0072]

EXAMPLES Examples of the epoxy resin composition according to the present invention, an ink jet head manufacturing method using the same, and comparative examples will be described in detail. In the following, “parts” and “%” are based on weight. In addition, the obtained epoxy resin composition was tested and evaluated by the following methods.

[Evaluation Method of Epoxy Resin Composition] (1) Adhesion: Peel Strength Test and Tensile Strength Test (1-1) Peel Test A 50 μm thick Ni film was coated on a 50 μm thick Si wafer by epoxy resin composition. Adhesion (curing adhesion) with an object and Ni
/ Si adhesive film (adhesion area: 1 cm ² ) sample, speed of 2.0 mm / min (peeling angle 90 °)
Was used to measure the peel strength. The evaluation criteria are as follows. ：: more than 200 gf / cm △: 100 to 200 gf / cm ×: less than 100 gf / cm

(1-2) Tensile Strength Test A sample of the Ni / Si adhesive film was placed on a SUS block (thickness × length × width = 10 mm × 30 mm × 10 mm).
And the tensile strength was measured at a speed of 5.0 mm / min. The evaluation criteria are as follows. ：: Exceeds 50 kgf / cm ² (4.9 × 10 ⁶ Pa) △: 10 to 50 kgf / cm ² (9.8 × 10 ⁵ to 4.
9 × 10 ⁶ Pa) ×: less than 10 kgf / cm ² (9.8 × 10 ⁵ Pa)

(2) Adhesion reliability: peel strength test and pull
Tensile strength test Ink resistance test for the above sample
Immersion: 50 ° C, 40h, ultrasonic vibration added)
Thereafter, a peeling test and a tensile strength test were performed. This place
The peel angle and tensile strength in the case are the same as above.
In addition, the evaluation standard exceeds 100 gf / cm in a peel test,
And 10kgf / cm in tensile strength test ^Two More than
Is indicated by ○, and the others are indicated by ×.

(3) Ink resistance The cured product of the epoxy resin composition was immersed in each of the following inks (50 ° C., 40 h, ultrasonic wave). Those were marked as x. In this case, each ink composition formulated with the following composition was stirred and dissolved at room temperature,
After adjusting the pH to 10.5 with lithium hydroxide, the mixture was filtered through a Teflon (registered trademark) filter having a thickness of 0.22 μm, and further degassed for about 30 minutes to obtain an ink for an ink resistance test. did.

[Composition of Black Ink] CIDirect Black 168 (Zeneca dye) 4% by weight Diethylene glycol 15% by weight Glycerin 5% by weight ECTD-3NEX (Nikko Chemicals) 1% by weight Proxel XL (manufactured by ICI) 0.4% by weight Ion Replaced water 74.6% by weight

[Composition of Yellow Ink] Pro-jet Fast Yellow 2 (Zeneca dye) 1.5% by weight CIDirect Yellow 142 (Daiwa Chemical dye) 0.5% by weight Diethylene glycol 15% by weight Glycerin 5% by weight ECTD-3NEX ( Nikko Chemicals) 1% by weight Sun Eye Back AP (manufactured by Sanai Sekiyu KK) 0.4% by weight Ion-exchanged water 76.6% by weight

(4) Applicability of epoxy resin composition: A sample which can be applied continuously and has a uniform coating film was evaluated as ○, and a film which was not so evaluated as ×. (5) Bleeding out of the epoxy resin composition: After hardening and bonding, those having no bleeding were evaluated as ○, and those not bleeding were evaluated as x. (6) Curing temperature of the epoxy resin composition: 130 ° C. or lower was evaluated as ○, and not so as ×. (7) Pot life of epoxy resin composition: After preparing the composition (mixing the epoxy resin and the curing agent), those having a pot life of 1 hour or more at room temperature were rated as ○, and those not having the pot life were rated as x.

[Production Example of Inkjet Head] Here, a method for producing an electrostatic inkjet head using the epoxy resin composition of the present invention will be described, but the present invention is not limited to this production method. FIG.
2A to 2F are plan views showing a manufacturing process of an ink jet head, and FIGS. 2A to 2G are cross-sectional views showing a manufacturing process of an actuator section. FIG. 3 is an exploded perspective view of the electrostatic inkjet head.

First, as shown in FIG.
0) A Si substrate 201 is prepared, and an electrode portion 202 and a gap portion 203 are formed on the Si substrate 201. In FIG. 1A, the figure on the right is an Si substrate 201 (silicon wafer), and the figure on the left is an enlarged view of a part thereof (the same applies to FIG. 1B below). ].

As shown in FIG. 1B, a (110) Si substrate 204 into which boron was implanted was prepared.
04 and the Si substrate (electrode substrate) 201 by direct bonding. The bonded wafer is polished to a thickness of 100 μm. Next, a nitride film serving as an etching mask is deposited on the electrode substrate 201 and the Si substrate 204 of the bonded wafer, and as shown in FIG. After the section 205 and the liquid chamber section 206 are formed by wet etching, this bonded wafer is cut by dicing to divide it into a number of chips.

Thereafter, as shown in FIG. 1D, the electrode portion 202 of the electrode substrate 201 on the upper and lower surfaces of the Si substrate 204 is formed.
Electrode extraction parts (openings) at both ends of the same side as the formation side
209 is formed by dry etching parallel to the liquid chamber 206. Thereafter, as shown in FIG. 1E, the actuator [electrostatic actuator] is electrically connected to the electrode extraction portion (opening) 209, that is, the exposed individual electrode, and the FPC cable 210 by an anisotropic conductive film. 220: FIG. 1 (f)]. The above FP
A driver IC is mounted on the C cable 210 in advance by wire bonding.

Next, the nozzle plate and the actuator are joined as follows. An epoxy resin composition is applied to the upper surface of the liquid chamber 206 (silicon liquid chamber) formed on the actuator. Further, an epoxy resin composition is applied to seal the gap (the entrance of the vibration chamber) of the vibration plate formed on the actuator. Then Figure 1
As shown in (f), the nozzle plate 212 formed by Ni electroforming and the electrostatic actuator 220 coated with the epoxy resin composition are aligned, pressurized, heat-cured, and bonded.

Here, an example of the manufacturing process of the electrostatic actuator 220 will be described in more detail. FIG. 2 is a sectional view showing each step. FIG. 3 is an exploded perspective view of an electrostatic inkjet head constituted by the electrostatic actuator.

As shown in FIG. 2A, a P-type (100) Si substrate 301 (625 μm thick) to be used as an electrode substrate
And a 2 μm thick silicon oxide film 3
02 was formed by wet oxidation. The oxidation conditions were, for example, 1050 ° C. and 18.5 h. Next, as shown in FIG. 2B, the resist was patterned using a gradation mask, and the silicon oxide film was patterned by dry etching and wet etching. By forming an electrode shape using a gradation mask, a non-parallel gap can be formed, and an electrode shape that is advantageous for lowering voltage can be formed.

Next, as shown in FIG. 2C, a TiN film 303 serving as an electrode is
It was formed to a thickness of nm by a sputtering method. Thereafter, the TiN film 303 was separated by etching for an individual electrode, and a silicon oxide film 304 was formed in a thickness of 150 nm as an electrode protection film. Next, the TiN film 303 other than the electrode portion was removed by dry etching of the silicon oxide film 304 and the TiN film 303 was removed by wet etching. Then Figure 2
(D) As shown in FIG.
The (110) Si substrate 305 is directly bonded to the Si substrate 301 via the oxide film 302 at 900 to 1000 ° C., and then the Si substrate 305 is polished to
05 was made 100 μm thick.

Next, the electrode substrate 301 and the Si substrate 30
5 was laminated and patterned, and FIG.
As shown in (e), a back channel 306 was formed in the electrode substrate 301 by wet etching. Then, FIG. 2 (f)
As shown in (1), a liquid chamber 307 was formed in the Si substrate 305 by wet etching, and the boron-implanted Si (Si substrate 305) and the silicon oxide film 304 were etched to open the back channel 306. Subsequently, by depositing aluminum through a metal mask, the liquid chamber 307 is formed.
Was formed. Here, the resultant was cut into chips by dicing, and thereafter, as shown in FIG. 2 (g), the electrode extraction portion 308 was opened by dry etching. Further, the silicon oxide film 304 on the TiN film 303 in the electrode extraction region was removed by dry etching. As described above, an actuator unit (shown by reference numeral 401 in FIG. 3) of the electrostatic inkjet head was manufactured.

Next (see FIG. 3), the electrostatic actuator 401 having the above configuration and the FPC cable 402 were electrically connected by an anisotropic conductive film. FPC cable 402
Has a driver IC 403 mounted in advance by wire bonding. In order to bond the electrostatic actuator 401 to the nozzle plate 404 formed by Ni electroforming, an epoxy resin composition was applied to the upper surface of the silicon liquid chamber of the actuator 401.

In the case of the electrostatic ink jet head, when the silicon liquid chamber and the nozzle plate 404 are bonded with the epoxy resin composition, the bleeding of the epoxy resin composition affects the ink ejection characteristics. 1
Since it is necessary to be about μm, when applying the adhesive on the upper surface of the silicon liquid chamber, the applied film thickness was controlled by a transfer method. That is, the epoxy resin composition was applied to the roller surface in the form of a thin film with a doctor blade, the epoxy resin composition on the roller was transferred to the transfer pad, and the epoxy resin composition was further transferred from the transfer pad to the upper surface of the silicon liquid chamber. .

An epoxy resin composition was applied to seal the gap of the diaphragm (the entrance of the vibration chamber).
In addition, the diaphragm will not be displaced when moisture enters the inside of the vibration chamber, but if an epoxy resin composition is used,
Good moisture resistance is also obtained.

In order to position the nozzle plate 404 and the silicon liquid chamber, the epoxy resin composition was applied to the epoxy resin composition application area 405 of the silicon liquid chamber by a dispenser. Then, the nozzle plate 404
And the electrostatic actuator 401 to which the adhesive was applied was aligned, and the epoxy resin composition was heated and cured under pressure. Further, a joint 406 for supplying ink from an ink supply tank or an ink cartridge was bonded to a frame 408 to which a filter 407 was heat-welded. An epoxy resin composition was applied to the frame 408 to bond the actuator 401 and the nozzle plate 404, and the actuator 401 was positioned and bonded.

In the ink jet head having the above-described structure, by applying a pulse voltage to the individual electrodes, the vibrating plate is deformed toward the electrodes by electrostatic force, and ink passes from the common liquid chamber through the fluid resistance portion to the pressure generating chamber. And the volume of the pressure generating chamber increases. Here, when the pulse voltage is released, the electrostatic force is eliminated, and the diaphragm returns to the original state.
The pressure in the pressure generating chamber is increased by the elastic force of the vibration plate, and ink is ejected from the nozzle holes.

Example 1 100 parts of liquid flexible epoxy resin (Epicoat YX310, manufactured by Yuka Shell Epoxy) 30 parts of liquid curing agent polyoxyalkyleneamine (Jeffamine D230, manufactured by HUNTSMAN) To produce an epoxy resin composition,
Using this, the following adhesion test was performed. Ni plate and Si wafer are superposed, and curing conditions: 60 ° C., 8 hours, pressure 2
An adhesive strength test sample and an ink resistance test sample were prepared at kgf / cm ² (19.6 × 10 ⁴ Pa),
This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 1 In place of the liquid flexible epoxy resin of Example 1, 100 parts of a solid epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a main ingredient.
An epoxy resin composition was prepared in the same manner except that 26 parts of a solid curing agent polyamine-modified adduct (manufactured by Asahi Denka Co., Ltd .: Adeka Hardener EH-4070S) was used as a curing agent and 40 parts of methyl carbitol was used as a solvent. After applying this composition, the solvent was dried by blowing with hot air, and then a cured sample was produced under the same curing conditions as in Example 1. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 2 100 parts of bisphenol A type epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy Co.) 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals) 4 parts Making a composition,
Using this, the following adhesion test was performed. The Ni plate and the Si wafer were overlapped, and a bonding strength test sample and an ink resistance test sample were prepared under a curing condition of 100 ° C. for 2 hours and a pressure of 1.5 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 2 Instead of the liquid bisphenol A type epoxy resin of Example 2, a solid epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a main ingredient.
, A solid curing agent polyamine-modified adduct (manufactured by Asahi Denka Co., Ltd .: ADEKA HARDNER EH-3731)
26 parts of S) and 40 parts of methyl carbitol as a solvent.
And an epoxy resin composition was prepared in the same manner except that each of the components was used. After applying this composition and drying the solvent with hot air, a cured sample was prepared under the same curing conditions as in Example 2. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 3 100 parts of a flexible epoxy resin (Flep 50, manufactured by Toray Thiokol Ltd.) 37 parts of aromatic amine (manufactured by Air Products, Inc .: Ancamine LVS) An epoxy resin composition obtained by stirring and mixing the above components. And make
Using this, the following adhesion test was performed. Ni plate and Si wafer are superposed, and curing conditions: 60 ° C., 8 hours, pressure 2
A sample for an adhesion strength test and a sample for an ink resistance test were prepared at kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 3 Instead of the liquid flexible epoxy resin of Example 3, 100 parts of a solid epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a main ingredient.
An epoxy resin composition was prepared in the same manner except that 28 parts of Ancamine LVS and 40 parts of methyl carbitol as a solvent were used, and after applying this composition, the solvent was dried with hot air and then dried. A cured sample was prepared under the same curing conditions as described above. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 4 90 parts of liquid flexible epoxy resin (Epicoat YX310, manufactured by Yuka Shell Epoxy) 10 parts of liquid glycidylamine-based epoxy resin (TETERAD-X, manufactured by Mitsubishi Gas Chemical Company) Liquid curing agent poly 22 parts of oxyalkyleneamine (Jeffamine EDR148, manufactured by HUNTSMAN) The above composition was stirred and mixed to prepare an epoxy resin composition,
Using this, the following adhesion test was performed. Ni plate and Si wafer are superposed, and curing conditions: 60 ° C., 8 hours, pressure 2
A sample for an adhesion strength test and a sample for an ink resistance test were prepared at kgf / cm ² . About this sample,
The evaluation was performed according to the above-mentioned agent evaluation method. Table 1 shows the results.

[Comparative Example 4] Instead of the liquid flexible epoxy resin of Example 4, 90 parts of a solid epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a main ingredient, and a solid phenol / novolak type resin (oil) was used. Shell Epoxy Co .: Epicoat 154), 10 parts, Jeffamine E
An epoxy resin composition was prepared in the same manner except that 20 parts of DR148 and 40 parts of methyl carbitol as a solvent were used, and after applying this composition, the solvent was dried with hot air and then dried in Example 4. A cured sample was produced under the same curing conditions. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

[Example 5] Bisphenol hexafluoroisopropyl glycidyl ether 30 parts Liquid flexible epoxy resin 70 parts (Yuika Shell Epoxy Co., Ltd., Epicoat YX310) Liquid curing agent polyamidoamine 41 parts (Fuji Kasei Corporation, # 296 ) The above composition is stirred and mixed to produce an epoxy resin composition,
The following adhesion test was performed using this. The Ni plate and the Si wafer were superposed on each other to prepare an adhesive strength test sample and an ink resistance test sample at a curing condition of 60 ° C. for 8 hours and a pressure of 1.5 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 5 Instead of the liquid flexible epoxy resin of Example 5, 100 parts of a solid epoxy resin (Epicoat 1001 manufactured by Yuka Shell Epoxy Co., Ltd.) was used as a main ingredient.
An epoxy resin composition was prepared in the same manner except that 18 parts of polyamidoamine # 296 and 40 parts of methyl carbitol were used as a solvent. After applying this composition, the solvent was dried with hot air, and then a cured sample was prepared under the same curing conditions as in Example 5. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

[Example 6] 100 parts of liquid flexible epoxy resin (Epicoat YX310, manufactured by Yuka Shell Epoxy) 53 parts of liquid curing agent polyoxyalkyleneamine (Jeffamine D400, manufactured by HUNTSMAN) The above composition was mixed by stirring. Thus, an epoxy resin composition was prepared. The following adhesion test was performed using this. Ni plate and S
The i-wafers were overlapped, and a bonding test sample and an ink resistance test sample were prepared under a curing condition of 60 ° C. for 8 hours and a pressure of 2 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 6 Instead of the liquid curing agent polyoxyalkyleneamine of Example 6, a solid curing agent polyamine-modified adduct (Adeka Hardener EH- manufactured by Asahi Denka Co., Ltd.)
4070S) An epoxy resin composition was produced in the same manner except that 26 parts were used, and a cured sample was produced under the same curing conditions as in Example 6. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 7 100 parts of liquid flexible epoxy resin (Epicoat YX310 manufactured by Yuka Shell Epoxy) 60 parts of liquid curing agent heterocyclic amine (Epomate N001 manufactured by Yuka Shell Epoxy) Stir and mix to make an epoxy resin composition,
The following adhesion test was performed using this. Ni plate and Si wafer are superposed, and curing conditions: 60 ° C., 8 hours, pressure 2
A sample for an adhesion strength test and a sample for an ink resistance test were prepared at kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 7 An epoxy resin was prepared in the same manner as in Example 7 except that 8 parts of a solid curing agent dicyandiamide was used in place of the heterocyclic amine liquid curing agent and 10 parts of methyl carbitol was used as a solvent. A composition was made. After applying the composition, the solvent was dried by blowing with hot air, and then a cured sample was prepared under the same curing conditions as in Example 7. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 8 100 parts of bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy) 30 parts of liquid curing agent polyoxyalkyleneamine (Jeffamine D230 manufactured by HUNTSMAN) Inorganic filler: amorphous Silica 10 parts (Nippon Aerosil Co., Ltd .: R972) Silane coupling agent: 3% by weight based on the total weight (Shin-Etsu Silicone Co., Ltd .: KBM403) Except for the curing agent having the above composition, the mixture is stirred and mixed and further kneaded with a three-roll mill. Thus, a main composition was obtained. A curing agent was added thereto, followed by stirring and mixing to obtain an epoxy resin composition. The following adhesion test was performed using this epoxy resin composition. The Ni plate and the Si wafer were superposed on each other to prepare an adhesive strength test sample and an ink resistance test sample under a curing condition of 60 ° C. for 8 hours and a pressure of 3 kgf / cm ² (29.4 × 10 ⁴ Pa). This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 8 The liquid curing agent Jeffamine D230 was used without adding the inorganic filler of Example 8, and
An epoxy resin composition was prepared in the same manner except that 8 parts of a solid curing agent dicyandiamide was used and 10 parts of methyl carbitol was used as a solvent. After applying this composition,
After the solvent was dried with hot air, a cured sample was prepared under the same curing conditions as in Example 8. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 9 100 parts of bisphenol A type epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy) 40 parts of liquid curing agent polyoxyalkyleneamine (Jeffamine T403, manufactured by HUNTSMAN) 10 parts of polymer particles ( Acrylic particles: Nippon Zeon Co., Ltd .: F351) Inorganic filler: amorphous silica 5 parts (Nippon Aerosil Co., Ltd .: R972) Silane coupling agent 3% by weight based on the total weight (Shin-Etsu Silicone Co., Ltd .: KBM403) The components other than the curing agent were stirred and mixed, and further kneaded with a three-roll mill to obtain a base composition. A curing agent was added thereto, followed by stirring and mixing to obtain an epoxy resin composition. The following adhesion test was performed using this epoxy resin composition. A Ni plate and a Si wafer were superposed on each other to prepare an adhesive strength test sample and an ink resistance test sample under a curing condition of 60 ° C. for 8 hours and a pressure of 3 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

[Comparative Example 9] A solid curing agent polyamine-modified adduct (Adeka Hardener EH-40, manufactured by Asahi Denka Co., Ltd.) was used without adding any of the polymer particles and the inorganic filler of Example 9.
70S) An epoxy resin composition was prepared in the same manner except that 60 parts were used, and a cured sample was prepared under the same curing conditions as in Example 9. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 10 100 parts of bisphenol A type epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy) 38 parts of liquid curing agent polyoxyalkyleneamine (Jeffamine D400, manufactured by HUNTSMAN) Liquid curing agent polyoxyalkylene Amine 25 parts (manufactured by HUNTSMAN, Jeffamine D2000) Curing accelerator 10 parts (manufactured by HUNTSMAN, AC399) Inorganic filler: amorphous silica 5 parts (manufactured by Nippon Aerosil Co., Ltd .: R972) Silane coupling agent 3 parts by weight % By weight (manufactured by Shin-Etsu Silicone Co., Ltd .: KBM403) The hardener having the above composition was mixed with stirring and further kneaded with a three-roll mill to obtain a base composition. A curing agent was added thereto, followed by stirring and mixing to obtain an epoxy resin composition. The following adhesion test was performed using this epoxy resin composition. A Ni plate and a Si wafer were superposed on each other to prepare an adhesive strength test sample and an ink resistance test sample under a curing condition of 60 ° C. for 8 hours and a pressure of 3 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Comparative Example 10 Polymer particles of Example 10
An epoxy resin composition was prepared in the same manner except that neither an inorganic filler nor a curing accelerator was added and 85 parts of an acid anhydride (Asahi Denka, EH3326) was used as a curing agent. After applying this composition, the solvent was dried by blowing with hot air, and a cured sample was prepared under the same curing conditions as in Example 10. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

[Example 11] 90 parts of flexible epoxy resin (Epicoat 292, manufactured by Yuka Shell Epoxy) 57 parts of liquid curing agent heterocyclic amine (Epomate N001, manufactured by Yuka Shell Epoxy) Reactive diluent (Asahi Denka ED503) 10 parts Inorganic filler: amorphous silica 10 parts (Nippon Aerosil Co., Ltd .: R972) Silane coupling agent 3% by weight based on the total weight (Shin-Etsu Silicone Co., Ltd .: KBM403) Other than the above-mentioned curing agent Was stirred and mixed, and further kneaded with a three-roll mill to obtain a base composition. A curing agent was added thereto, followed by stirring and mixing to obtain an epoxy resin composition. The following adhesion test was conducted using this epoxy resin composition. The Ni plate and the Si wafer were superposed on each other to prepare an adhesive strength test sample and an ink resistance test sample at a curing condition of 60 ° C. for 8 hours and a pressure of 3 kgf / cm ² . This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

[Comparative Example 11] The inorganic filler of Example 11,
Without adding any of the reactive diluents, instead of the flexible epoxy resin, 100 parts of a solid epoxy resin (manufactured by Yuka Shell Epoxy Co., Epicoat 1001) was used as a base material,
An epoxy resin composition was prepared in the same manner except that 40 parts of methyl carbitol was used as a solvent. After applying this composition, the solvent was dried by blowing with hot air, and a cured sample was prepared under the same curing conditions as in Example 11. This sample was evaluated according to the evaluation method described above. Table 1 shows the results.

Example 12: Room Temperature Curing Adhesion A sample was prepared in the same manner as in Example 1 except that the epoxy resin composition of Example 1 was cured at normal temperature (room temperature) for 48 hours. This sample was evaluated according to the evaluation method described above. Table 1 shows the results. Also, when an inkjet head was manufactured according to the inkjet head manufacturing example,
It was confirmed that the ink was ejected from the nozzle holes with high accuracy, and there was no distortion of the inkjet head.

Comparative Example 12 A sample was prepared in the same manner as in Example 12, except that the epoxy resin composition of Comparative Example 10 was cured at 180 ° C. for 2 hours. This sample was evaluated according to the evaluation method described above. Table 1 shows the results. In addition, when an inkjet head was manufactured according to the inkjet head manufacturing example, distortion of the inkjet head was confirmed.

Example 13: After-curing after primary curing and adhesion, except that the epoxy resin composition of Example 6 was cured at room temperature (room temperature) for 48 hours and then after-cured at 120 ° C. A sample was prepared in the same manner. This sample was evaluated according to the evaluation method described above. Table 1 shows the results. In addition, when an ink jet head was manufactured according to the ink jet head manufacturing example, it was confirmed that ink was ejected from the nozzle holes with high accuracy, and that there was no distortion of the ink jet head.

Comparative Example 13 A sample was prepared in the same manner as in Example 12, except that the epoxy resin composition of Comparative Example 8 was cured at 180 ° C. for 2 hours. This sample was evaluated according to the evaluation method described above. Table 1 shows the results. In addition, when an inkjet head was manufactured according to the inkjet head manufacturing example, distortion of the inkjet head was confirmed.

Example 14: Adhesion of Ni-iron alloy nozzle plate A Ni-iron alloy nozzle plate (Ni content 38%) was used, and the epoxy resin composition of Example 7 was used.
The composition was cured and adhered at 2 ° C. for 2 hours. This sample was evaluated according to the evaluation method described above. Table 1 shows the results. Also,
When an ink-jet head was manufactured according to the ink-jet head manufacturing example, it was confirmed that ink was ejected from the nozzle holes with high precision and that there was no distortion of the ink-jet head.

[Comparative Example 14] In place of using a Ni-iron alloy nozzle plate (Ni content 38%), a Ni nozzle plate was used, and the epoxy resin composition of Example 7 was used. Time cure bonding was performed.
In addition, when an inkjet head was manufactured according to the inkjet head manufacturing example, distortion of the inkjet head was confirmed.

[0122]

[Table 1]

[0123]

According to the epoxy resin composition of the present invention, a high bonding function and bonding effect can be obtained. For example, a member forming an ink flow path portion of the inkjet head,
When used as an adhesive for bonding the members constituting the liquid chamber portion, the ink resistance, particularly the alkali resistance, and the adhesion between the members after long-term immersion are improved, and the peel strength is high,
It is possible to provide an epoxy resin composition for manufacturing an ink jet head having good workability.

Further, according to the method of manufacturing an ink jet head according to the present invention, a high-precision and high-performance ink jet head can be provided by bonding head constituent members using the epoxy resin composition. it can. Hereinafter, effects of the present invention will be described for each claim.

[Effect of Claim 1] An adhesive having uniform adhesiveness, high curability, and a high degree of adhesive function, which contains at least a liquid epoxy resin and a liquid curing agent and is solvent-free. Can be. Therefore, by using this epoxy resin composition as an adhesive for manufacturing an ink jet head, ink resistance is improved, adhesion between members is increased, peel strength is improved, and an ink jet head having good workability is provided. be able to.

[Effect of Claim 2] Since at least a bisphenol-based epoxy resin is contained as a liquid epoxy resin, the use of the epoxy resin composition of the present invention as an adhesive for manufacturing an ink jet head improves ink resistance. In addition, it is possible to provide an ink jet head having high adhesion between members.

[Effect of Claim 3] Since at least a flexible epoxy resin is contained as a liquid epoxy resin, the epoxy resin composition of the present invention is used as an adhesive for manufacturing an ink jet head. The peel strength of the ink can be increased, and an ink jet head having good ink resistance can be provided.

[Effect of Claim 4] Since at least a glycidylamine-based epoxy resin is contained as a liquid epoxy resin, when the epoxy resin composition of the present invention is used as an adhesive for manufacturing an ink jet head, the pot life is reduced. Can be adjusted, and an ink jet head having good workability can be provided.

[Effect of Claim 5] Since at least a fluorinated epoxy resin is contained as a liquid epoxy resin, when the epoxy resin composition of the present invention is used as an adhesive for manufacturing an ink jet head, the head constituent members are not bonded to each other. The peel strength of the ink becomes good, and an ink jet head with improved ink resistance can be provided.

[Effect of Claim 6] Since a curing agent having a function of imparting at least flexibility to a cured product is used as a liquid curing agent, the epoxy resin composition of the present invention is used as an adhesive for manufacturing an ink jet head. In such a case, it is possible to provide an ink jet head in which the peel strength between the head constituent members is improved.

[Effect of Claim 7] As the liquid curing agent having a function of imparting flexibility to the cured product, any one of a polyamideamine-based curing agent, a polyoxyalkyleneamine-based curing agent, and a heterocyclic amine-based curing agent is used. Therefore, when the epoxy resin composition of the present invention is used as an adhesive for manufacturing an ink jet head, it is possible to provide an ink jet head having high peel strength between head constituent members and improved ink resistance. it can.

[Effect of Claim 8] By mixing at least an inorganic filler as a filler, the viscosity of the epoxy resin composition can be adjusted and workability is improved. In addition, by using the epoxy resin composition of the present invention as an adhesive for manufacturing an inkjet head, bleeding during curing and adhesion is prevented, and a high-performance inkjet head can be provided.

[Effect of Claim 9] By mixing at least polymer particles as a filler, the viscosity of the epoxy resin composition can be adjusted and workability is improved. In addition, by using the epoxy resin composition of the present invention as an adhesive for manufacturing an ink jet head, exudation at the time of curing and bonding is prevented, and the adhesive is given flexibility. For this reason, it is possible to provide an ink jet head having a high peel strength between head constituent members.

[Effect of Claim 10] By adding a curing accelerator, the curability of the epoxy resin composition is improved. Therefore, by using the epoxy resin composition of the present invention as an adhesive for manufacturing an ink jet head, an ink jet head having improved ink resistance and improved peel strength can be provided.

[Effect of Claim 11] The viscosity of the epoxy resin composition can be adjusted by adding the epoxy resin reactive diluent, so that an adhesive having good workability during bonding can be provided. Therefore, when the epoxy resin composition of the present invention is used as an adhesive for manufacturing an inkjet head, an inkjet head can be manufactured with good workability.

[Effect of Claim 12] Since the constituent members of the ink jet head are adhered to each other by using the epoxy resin composition of any one of Claims 1 to 11, the ink resistance is improved, and Adhesion is enhanced, peel strength is improved, and an ink jet head with good workability can be provided.

[Effect of Claim 13] Since the components of the ink jet head are bonded by curing the epoxy resin composition at room temperature, the thermal stress at the time of thermosetting bonding is reduced. For this reason, it is possible to provide an ink jet head in which adhesion distortion of a liquid chamber, a nozzle plate, and the like is reduced.

[Effect of Claim 14] The components of the ink jet head are first cured at room temperature or at a lower temperature than the epoxy resin composition, and then after-cured and adhered. It is possible to provide an ink jet head having improved properties and ink resistance and further improved peel strength.

[Effect of Claim 15] Since the nozzle plate made of Ni-iron alloy and the head body made of silicon are bonded by the bonding method according to any one of Claims 12 to 14, the curing temperature is increased. , The distortion of the ink-jet head is reduced, and an ink-jet head with a small stress applied to the head body can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a manufacturing process of an inkjet head.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the actuator section.

FIG. 3 is an exploded perspective view of the electrostatic inkjet head.

[Explanation of symbols]

 201 Si substrate (electrode substrate) 202 Electrode part 203 Gap part 204 Si substrate 205 Back flow path part 206 Liquid chamber part 209 Electrode extraction part (opening) 210 FPC cable 212 Nozzle plate 220 Electrostatic actuator 301 Si substrate (electrode substrate) 302 Silicon oxide film 303 TiN film 304 Silicon oxide film 305 Si substrate 306 Back flow path 307 Liquid chamber 308 Electrode take-out part 401 Actuator part (electrostatic actuator) 402 FPC cable 403 Driver IC 404 Nozzle plate 405 Epoxy resin composition application area 406 Joint part 407 Filter 408 Frame

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI theme coat ゛ (reference) C08L 63/00 C08L 63/00 A 101/00 101/00 F term (reference) 4J002 BB023 BB113 BC023 BG063 CC043 CC183 CC193 CD003 CD014 CD05W CD051 CD12W CD121 CD13W CD131 CD134 CH05X CK023 CL00X DE107 DE117 DE137 DE147 DE237 DG047 DJ007 DJ017 DJ027 DJ037 DJ047 DJ057 DL007 EC038 EJ028 EL029 EL039 EN028 EN108 EU039 EU118 EU138 FA047 FD001 FD0100 FD0100 AH01 AH04 AJ06 DA01 DA02 DA05 DC38 FA01 FA11 FB01 FB06 FB12 FB13 JA06 KA07

Claims (15)

[Claims] 1. An epoxy resin composition containing at least a liquid epoxy resin and a liquid curing agent and being solvent-free. 2. The epoxy resin composition according to claim 1, wherein the liquid epoxy resin contains at least a bisphenol-based epoxy resin. 3. The liquid epoxy resin according to claim 1, wherein the liquid epoxy resin contains at least a flexible epoxy resin.
The epoxy resin composition according to the above. 4. The epoxy resin composition according to claim 1, wherein the liquid epoxy resin contains at least a glycidylamine epoxy resin. 5. The epoxy resin composition according to claim 1, wherein the liquid epoxy resin contains at least a fluorinated epoxy resin. 6. The epoxy resin composition according to claim 1, wherein the liquid curing agent has a function of imparting at least flexibility to the cured product. 7. The epoxy resin composition according to claim 6, wherein the liquid curing agent is any of a polyamideamine-based curing agent, a polyoxyalkyleneamine-based curing agent, and a heterocyclic amine-based curing agent. . 8. The epoxy resin composition according to claim 1, wherein at least an inorganic filler is blended as the filler. 9. The epoxy resin composition according to claim 1, wherein at least polymer particles are blended as a filler. 10. The epoxy resin composition according to claim 1, further comprising a curing accelerator. 11. The epoxy resin composition according to claim 1, further comprising an epoxy resin reactive diluent. 12. A method for manufacturing an ink-jet head, comprising bonding constituent members of the ink-jet head to each other using the epoxy resin composition according to claim 1. Description: 13. The method for manufacturing an ink jet head according to claim 12, wherein constituent members of the ink jet head are bonded by curing an epoxy resin composition at room temperature. 14. The ink jet head according to claim 12, wherein the constituent members of the ink jet head are firstly cured at a room temperature or a lower temperature of the epoxy resin composition, and then after-cured and bonded. A method for manufacturing an ink jet head. 15. A nozzle plate made of a Ni-iron alloy and a head body made of silicon.
14. A method for manufacturing an ink jet head, wherein the method is performed by the bonding method according to any one of 14.