JP2002210964A - Ink jet head and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet head exhibiting high resistance against various inks, and a method for manufacturing the ink jet head with high workability and efficiency. SOLUTION: Since an adhesive containing polysiloxane modified epoxy resin is employed at a bonding part touching ink, an ink jet head exhibiting resistance against various inks can be provided without sacrifice of various characteristics required for the adhesive of ink jet head. An ink jet head exhibiting high ink resistance and high positional accuracy while preventing ooze-out or flow-out of adhesive can be manufactured efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet head and a method for manufacturing the ink jet head.

[0002]

2. Description of the Related Art Ink jet technology, in which small droplets of ink are caused to fly and adhere to an object, includes printers for printing characters and images on paper, film, and cloth, as well as FAX and copier machines, as well as the manufacture of color filters and organic inks. It is applied to a wide range of fields such as the manufacture of EL displays. Depending on the field of application, various types of inks are used, such as dyes and pigments, and various inorganic and organic substances dissolved or dispersed in water or an organic solvent.

There are known various ink jet heads that fly ink droplets in small droplets. Adhesives are used in the manufacture of these ink jet heads, but adhesives used in ink jets require various performances, and usually do not contain solvents, such as epoxy adhesives and silicone adhesives. Is used. Since silicone-based adhesives have low adhesive strength, epoxy-based adhesives are often used for main functional parts of the head.

[0004]

One of the properties required for an adhesive used in an ink jet is the resistance of the adhesive at the joint in contact with the ink to the ink. To apply inkjet heads to a wide range of fields, it is necessary to use adhesives that are resistant to various inks, but adhesives that satisfy other performances and are resistant to various inks Did not. For example, epoxy adhesives such as Hitachi Chemical's Hibon 3000, Cemedine's Cemedine 1500, EP-007, and Alpha Giken's R-2007 and H-1004 swell with solvents such as water and organic solvents, and have an adhesive strength. The ink drops and the head is destroyed or ink leaks. Technodyne AH30 manufactured by Taoka Chemical Co., Ltd.
Although 41W is more resistant than these adhesives, it was not yet sufficient.

On the other hand, adhesives used in ink jets are required to have the following performance in addition to ink resistance. Manufacturing performance includes high storage stability when uncured, a low curing temperature, a viscosity in application within a certain range, and suitability for application methods.

[0006] In order to prevent unintentional curing from proceeding before or during the bonding operation and deteriorating the performance after bonding, it is necessary to have high storage stability when uncured. The two-part adhesive, which mixes the main agent and the curing agent before bonding, has excellent storage stability, but requires a uniform mixing of the two parts to promote uniform curing, resulting in poor workability and workability. During the curing, the application condition changes because the physical property value of the adhesive changes over time. A one-component adhesive using a latent curing agent that does not proceed to cure at room temperature is preferable, but it is difficult to completely prevent curing at room temperature, and it is usually necessary to store at a low temperature.

[0007] Adhesion of an ink jet head requires an extremely high dimensional accuracy of 10 µm or less. However, if the curing temperature at the time of adhesion is high, the difference in the coefficient of thermal expansion between the members to be adhered causes
It is difficult to maintain positional accuracy.

Further, when the temperature of the piezoelectric element is raised to 100 to 150 ° C. or higher, the polarization is lost and the piezoelectric effect is not seen or the efficiency is reduced. For this reason, the lower the curing temperature, the better. However, simply curing at low temperature does not increase the crosslink density, and the adhesive strength, elastic modulus,
Ink resistance decreases.

[0009] The ink jet head is composed of nozzles and ink flow paths of 100 µm or less, and the protrusion of the adhesive to the area other than the adhesive surface must be several µm or less. For this reason, the application of the adhesive is performed by transfer, screen printing, flexographic printing, and the like. In particular, screen printing and flexographic printing are preferable, but such printability is required. In particular, if the viscosity is too high, the coating cannot be performed, and if the viscosity is too low, it will run out and run out, so that it is necessary to be within a certain range.

[0010] As a method that is effective in preventing run-out and flow-out and in positioning accuracy, it is preferable to apply the adhesive to at least one member to which the adhesive is to be adhered, and then form the B-stage and adhere. The B stage means that when the curing (polymerization reaction) has progressed to some extent, the progress of the polymerization reaction is temporarily stopped, and a stable state in which curing hardly proceeds at room temperature is obtained.

The properties after curing include high adhesive strength and high elastic modulus. Adhesive strength and durability are required so that the bonded part does not peel off within the durability time of the other part of the head. In the bonding of the pressure generating member, if the elastic modulus is low, the pressure is released and the efficiency is reduced, so that the pressure generating member is required to be particularly high.

An object of the present invention is to provide an ink jet head having high resistance to various inks, and a method for manufacturing the ink jet head which can obtain the ink jet head with good workability and high efficiency.

[0013]

In order to achieve the above object, an ink jet head according to the present invention and a method for manufacturing the same are constituted as follows.

According to a first aspect of the present invention, in an ink jet head in which at least two members are joined by an adhesive, an adhesive containing a polysiloxane-modified epoxy resin is included in at least a part of an adhesive at a joining portion in contact with the ink. An ink-jet head characterized by using:

According to the first aspect of the present invention, it is possible to provide an ink jet head having resistance to various inks without sacrificing other characteristics.

According to a second aspect of the present invention, the adhesive containing the polysiloxane-modified epoxy resin contains dicyandiamide or a derivative of dicyandiamide as a curing agent. Head.

According to the second aspect of the present invention, a curing reaction does not occur at room temperature, and the composition can be used as a one-part adhesive which can be stored in a state where a polysiloxane-modified epoxy resin as a main component and a curing agent are mixed in advance. The workability is excellent, the adhesive is bonded to the B-stage, and then bonded, so that the adhesive is less protruded and the bonding position is highly accurate.

The invention according to claim 3 is characterized in that the adhesive containing the polysiloxane-modified epoxy resin contains an aliphatic amine epoxy adduct as a reaction accelerator. It is an inkjet head of description.

According to the third aspect of the invention, it is possible to improve the wettability of the member on which the adhesive is applied. In addition, the curing temperature at the time of bonding can be lowered, and the bonding strength can be increased without lowering the bonding position accuracy due to thermal expansion or deteriorating the piezoelectric element that generates ink ejection energy.

According to a fourth aspect of the present invention, there is provided a nozzle plate on which a nozzle for discharging ink is formed, and a pressure chamber for generating energy for discharging ink, and a joint portion between the nozzle plate and another member. The inkjet head according to any one of claims 1 to 3, wherein an adhesive containing the polysiloxane-modified epoxy resin is used.

According to the fourth aspect of the invention, the bonding position of the nozzle plate is highly accurate, the adhesive does not protrude into the nozzle, the ink flow path, and the pressure chamber, and the amount and speed of the flying ink droplets In addition, it is possible to provide an inkjet head having a stable emission angle.

According to a fifth aspect of the present invention, there is provided a pressure chamber for generating energy for ejecting ink, a member provided on the ink introduction side of the pressure chamber to restrict the flow of ink, and another member. The inkjet head according to any one of claims 1 to 3, wherein an adhesive containing the polysiloxane-modified epoxy resin is used in a joint portion with the ink jet head.

According to the fifth aspect of the present invention, it is possible to provide an ink jet head capable of stably driving at high speed by controlling the behavior of the ink in the nozzles and the pressure chambers.

According to a sixth aspect of the present invention, there is provided a pressure chamber for generating energy for discharging ink, wherein the pressure chamber comprises a plurality of members, and at least two members among the plurality of members. The ink jet head according to any one of claims 1 to 3, wherein an adhesive containing the polysiloxane-modified epoxy resin is used for a joint between them.

According to the sixth aspect of the present invention, it is possible to increase the adhesive hardness of the members forming the pressure chamber, reduce the pressure loss, and provide an efficient ink jet head.

According to a seventh aspect of the present invention, a voltage is applied to a piezoelectric element formed outside the pressure chamber, and the piezoelectric element is expanded and contracted to deform the pressure chamber. The inkjet head according to any one of claims 1 to 6, wherein the inkjet head generates energy for discharging.

According to the seventh aspect of the present invention, it is possible to provide an ink jet head in which a pressure is generated by a highly efficient deformation mode of a piezoelectric element, and a pressure generated for ejection is high.

[0028] The invention according to claim 8 is characterized in that a heating element is provided in the pressure chamber, and by energizing the heating element, the ink is vaporized to generate energy for discharging the ink. Item 7. An inkjet head according to any one of Items 1 to 6.

According to the eighth aspect of the present invention, it is possible to provide an ink jet head which generates a high pressure for ejection, is inexpensive and easy to manufacture.

According to a ninth aspect of the present invention, all or a part of the members constituting the pressure chamber is formed of a piezoelectric element, and a voltage is applied to the piezoelectric element to cause a shear deformation, thereby discharging ink. The inkjet head according to any one of claims 1 to 6, wherein energy for generating the ink is generated.

According to the ninth aspect of the present invention, a pressure chamber is formed by cutting a groove in the piezoelectric element, and it is possible to provide an ink jet head which can be driven at a high speed and is easily manufactured.

According to a tenth aspect of the present invention, in the piezoelectric element, two piezoelectric elements polarized in different directions are joined with an adhesive containing the polysiloxane-modified epoxy resin. An inkjet head according to claim 9.

According to the tenth aspect, it is possible to provide a highly efficient ink jet head by increasing the deformation of the piezoelectric element.

According to an eleventh aspect of the present invention, in the method of manufacturing an ink jet head in which at least two members constituting the ink jet head are bonded with an adhesive, at least one of the members is modified with a polysiloxane to bond the two members. A step of applying an adhesive containing an epoxy resin, a step of heating the applied adhesive to form a B-stage, and a step of heating and curing the adhesive while applying pressure to the two members. And a step of joining two members.

According to the eleventh aspect of the present invention, it is possible to provide a method for efficiently manufacturing an ink jet head having high positional accuracy by using an adhesive having a high ink resistance without causing the adhesive to overflow or flow out. it can.

The adhesive of the present invention is an adhesive containing a polysiloxane-modified epoxy resin. This polysiloxane-modified epoxy resin contains 50 mol% as a main component of the adhesive.
It is preferable to contain the above. The polysiloxane-modified epoxy resin of the present invention has the same meaning as the epoxy-modified polysiloxane resin, and either one may be used.

The typical polysiloxane-modified epoxy resin of the present invention is, for example, a compound represented by the following structural formula (1) (where n = 1 to 10).

[0038]

Embedded image [Wherein, R is a polysiloxane group represented by the following structural formula (2) when n = 1, and a polysiloxane group represented by the following structural formula (2) or a hydrogen atom when n ≧ 2. And at least one of n is a polysiloxane group represented by the following structural formula (2) (where m = 0 to 100). ]

[0039]

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The skeleton of the polysiloxane-modified epoxy resin is a bisphenol A (1-1) represented by the structural formula (1).
In addition, tetrabromobisphenol A (1-2), bisphenol F (1-3), bisphenol AD (1-
4), bisphenol Z (1-5), (1-6), (1
Structures known as main agents of conventional epoxy resin adhesives, such as -7), (1-8), and (1-9), may be used.

[0041]

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The polysiloxane-modified epoxy resin is, for example, regioselectively selected from the group consisting of organosilanes, hydrolysates of the organosilanes and condensates of the organosilanes, at free hydroxyl groups of the epoxy resin. Obtained by chemical bonding.

As the organosilane, for example, R ¹ _n
Si (OR ² ) _4-n (where R ¹ is the same or different,
An organic group having 1 to 8 carbon atoms, R ² is the same or different and represents an alkyl group having 1 to 5 carbon atoms or an acyl group or a phenyl group having 1 to 6 carbon atoms, and n is an integer of 0 to 2) Specific examples include, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane,
Tetraalkoxysilanes such as tetraisopropoxysilane and tetrabutoxysilane; methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxy Silane, n-propyltriethoxysilane,
Isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane , Trialkoxysilanes such as phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane Dialkoxysilanes such as silane, halogen-based dimethyldichlorosilane, methyltrichlorosilane, and trimethylmonochlorosilane. .

As a catalyst for this reaction, for example, acidic compounds, alkaline compounds, salt compounds, amine compounds, organometallic compounds and / or partial hydrolysates thereof (hereinafter referred to as organometallic compounds and / or partial hydrolysates thereof) These are collectively referred to as “organometallic compounds”.

Examples of the acidic compound include acetic acid,
Examples include hydrochloric acid, sulfuric acid, phosphoric acid, metasulfonic acid, alkyltitanic acid, p-toluenesulfonic acid, and phthalic acid, and acetic acid is preferred.

As the above alkaline compound, for example,
Examples thereof include sodium hydroxide and potassium hydroxide, and preferably sodium hydroxide.

Examples of the salt compound include alkali metal salts such as naphthenic acid, octylic acid, nitrous acid, sulfurous acid, aluminate, and carbonic acid.

Examples of the amine compound include ethylenediamine, hexanediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, piperidine, piperazine, m-phenylenediamine, p-phenylenediamine, ethanolamine, triethylamine, and the like. 3-aminopropyl trimethoxysilane, 3-aminopropyl
Triethoxysilane, 3- (2-aminoethyl) -aminopropyl-trimethoxysilane, 3- (2-aminoethyl) -aminopropyl-triethoxysilane, 3-
(2-aminoethyl) -aminopropyl-methyl-dimethoxysilane, 3-anilinopropyl-trimethoxysilane, alkylamine salts, quaternary ammonium salts, and various modified amines used as curing agents for epoxy resins. Preferred are 3-aminopropyl-trimethoxysilane, 3-aminopropyl-triethoxysilane, and 3- (2-aminoethyl) -aminopropyl-triethoxysilane.

The above-mentioned organometallic compounds include, for example,
A compound represented by the following general formula (3) (hereinafter referred to as “organometallation
Compound (3) "), carbon bonded to the same tin atom
With tetravalent tin having 1-2 alkyl groups of 1-10
Metal compounds (hereinafter referred to as "organotin compounds")
Or partial hydrolysis products of these compounds.
Can be. M (OR^Three) P (R^FourCOCHCOR^Five) Q (3) [where M is zirconium, titanium or aluminum
And R^ThreeAnd R^FourAre the same or different and are ethyl
Group, n-propyl group, i-propyl group, n-butyl group,
sec-butyl group, t-butyl group, n-pentyl group, n
-Charcoal such as hexyl, cyclohexyl, phenyl, etc.
A monovalent hydrocarbon group having a prime number of 1 to 6, ^FiveIs R^ThreeAnd
And R^Four And other monovalent hydrocarbon groups having 1 to 6 carbon atoms.
Or methoxy, ethoxy, n-propoxy, i-
Propoxy group, n-butoxy group, sec-butoxy group,
t-butoxy group, lauryloxy group, stearyloxy
Represents an alkoxyl group having 1 to 16 carbon atoms such as a group,
And q are integers from 0 to 4, and (p + q) = (valence of M)
It is. ]

Specific examples of the organometallic compound (3) include:
For example, (a) tetra-n-butoxyzirconium, tri-n-
Butoxy ethyl acetoacetate zirconium, di-
n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium, etc. (Ii) tetra-i-propoxytitanium, di-i-propoxybis (ethylacetoacetate) titanium, di-i-propoxybis (acetylacetate)
Organic titanium compounds such as titanium and di-i-propoxy bis (acetylacetone) titanium; (c) tri-i-propoxy aluminum, di-i-propoxy ethyl acetoacetate aluminum, di-
aluminum i-propoxy acetylacetonate,
i-propoxybis (ethylacetoacetate) aluminum, i-propoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate)
Organic aluminum compounds such as aluminum, tris (acetylacetonate) aluminum, and monoacetylacetonatobis (ethylacetoacetate) aluminum can be exemplified.

Among these organometallic compounds (2) and partial hydrolysates thereof, tri-n-butoxyethylacetoacetate zirconium, di-i-propoxybis (acetylacetonato) titanium, di-i-propoxy・ Ethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum, or
Partial hydrolysates of these compounds are preferred.

Specific examples of the organotin compound include, for example, (C ₄ H ₉ ) ₂ Sn (OCOC ₁₁ H _{2 3} ) ₂ and (C ₄ H ₉ )
₂ Sn (OCOCH = CHCOOCH ₃ ) ₂ , (C ₄ H ₉ ) ₂
Sn (OCOCH = CHCOOC ₄ H ₉ ) ₂ , (C ₈ H ₁₇ )
₂ Sn (OCOC ₈ H ₁₇ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCO
C ₁₁ H ₂₃ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH ＝ CHC)
OOCH ₃ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH = CH
COOC ₄ H ₉ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH = C
HCOOC ₈ H ₁₇ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOCH =
CHCOOC ₁₆ H ₃₃ ) ₂ , (C ₈ H ₁₇ ) ₂ Sn (OCOC
_{H = CHCOOC 1 7 H 35)} 2, (C 8 H 17) 2 Sn (OC
OCH = CHCOOC ₁₈ H ₃₇ ) ₂ , (C ₈ H ₁₇ ) ₂ SnO
COCH = CHCOOC ₂₀ H ₄₁ ) ₂ ,

Embedded image (C ₄ H ₉ ) ₂ Sn (OCOC ₁₁ H ₂₃ ) ₃ , (C ₄ H ₉ ) ₂ S
carboxylic acid type organotin compounds such as n (OCONa) ₃ ;

(C_FourH₉)_TwoSn (SCH_TwoCOOC
₈H₁₇)_Two, (C_FourH₉)_TwoSn (SCH_TwoCH_TwoCOOC₈H
₁₇)_Two, (C₈H₁₇)_TwoSn (SCH_TwoCOOC₈H₁₇)_Two,
(C₈H₁₇) _TwoSn (SCH_TwoCH_TwoCOOC₈H₁₇)_Two,
(C₈H₁₇)_TwoSn (SCH_TwoCOOC₁₂H_{twenty five})_Two, (C₈
H₁₇)_TwoSn (SCH_TwoCH_TwoCOOC₁₂H_{twenty five})_Two, (C_Four
H₉) Sn (SCOCH = CHCOOC)₈H₁₇)_Three, (C₈
H₁₇) Sn (SCOCH = CHCOOC)₈H₁₇)_Three,

Embedded image Mercaptide-type organotin compounds such as

(C ₄ H ₉ ) ₂ Sn = S, (C ₈ H ₁₇ ) ₂ Sn
= S,

Embedded image Sulfide type organotin compounds such as;

(C ₄ H ₉ ) SnCl ₃ , (C ₄ H ₉ ) ₂ SnC
l ₂ , (C ₈ H ₁₇ ) ₂ SnCl ₂ ,

Embedded image Chloride-type organotin compounds such as;

(C ₄ H ₉ ) ₂ SnO, (C ₈ H ₁₇ ) ₂ SnO
And the reaction products of these organic tin oxides with ester compounds such as ethyl silicate, dimethyl maleate, diethyl maleate and dioctyl phthalate.

The catalyst can be used, for example, alone or as a mixture of two or more kinds, and can also be used as a mixture with a zinc compound or another reaction retarder. These catalysts are generally used in an amount of, for example, 0.5 to 50 parts by weight, preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the solid content. Further, it is preferable that the reaction proceeds only with the free hydroxyl group, and the reaction is carried out under reaction conditions that do not open the epoxy ring.

In the polysiloxane-modified epoxy resin of the present invention, the polysiloxane to be bound preferably weighs 5 to 50% in terms of SiO ₂ . Further, a mixture of a polysiloxane-modified epoxy resin and an unmodified epoxy resin can also be used as the main agent.

The curing agent used in the adhesive of the present invention is, for example, an aliphatic amine (typically, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, metaxylylenediamine, diethylaminopropylamine). , Alicyclic amines (typically, mensendiamine, isophoronediamine, N-aminoethylpiperazine, 3,9-bis (3
-Aminopropyl) -2,4,8,10-tetraoisspiro (5,5) undecane adduct, 1,3-bis (aminomethyl) cyclohexane, bis (4-amino-
3-methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane), aromatic amines (typically metaxylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine), acid anhydrides (typical To conventional ones such as dodecenyl succinic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid, tetrabromophthalic anhydride, and heptic anhydride) Although a curing agent for an adhesive mainly composed of an epoxy resin can be used, dicyandiamide (H ₂ N—C (NH) —
NH-CN) or its derivatives (typically o-
Tolylbiguanide, α-2,5-dimethylbiguanide,
α, ω-diphenylbiguanide, 5-hydroxynaphthyl-1-biguanide, α, α′-bisgranylguanidinodiphenyl ether, phenylbiguanide, p-chlorophenylbiguanide, α-bandylbiguanide, α,
α'-hexamethylene [ω- (p-chlorophenyl)]
Biguanide, o-tolylbiguanide zinc salt, diphenyl biguanide iron salt, phenyl biguanide copper salt, biguanide nickel salt, ethylene bis biguanide hydrochloride, lauryl biguanide hydrochloride, phenyl biguanide oxalate)
When used, the curing reaction does not occur at room temperature, and it can be used as a one-component adhesive that can be stored in a state where the main agent and the curing agent are mixed in advance, so that the workability is excellent and the B stage can be stably obtained. preferable. When the compounding ratio of the curing agent is equivalent or 60% or more of the equivalent, sufficient adhesion strength, elastic modulus, ink resistance and durability can be obtained after adhesion.

Further, when a polyamine is added as an adduct of an epoxy resin, ethylene oxide, and propylene oxide in addition to the main component and the curing agent of the polysiloxane-modified epoxy resin, it can act as a reaction accelerator and lower the curing temperature. In particular, by using an aliphatic amine epoxy adduct as a reaction accelerator, 100
Since the curing reaction starts below ℃, even if cured at a temperature that does not cause deterioration of the bonding position accuracy due to thermal expansion or deterioration of the piezoelectric element that generates ink ejection energy, sufficient bonding strength, elastic modulus, Ink properties and durability can be obtained.

In addition, the viscosity of the adhesive and the thickness after bonding can be controlled by adding and dispersing fine particles. Alumina, silica, etc. with a diameter of 0.01 to 10 μm
It is preferable to add singly or two or more kinds in the range described above. Further, the elastic modulus after bonding can be increased by dispersing and adding glass fiber, carbon fiber, aramid fiber and the like.

Next, an ink which can be used in an ink jet head in which the adhesive of the present invention is used for a joining portion in contact with the ink will be described.

Examples of the ink which can be ejected by the ink jet head of the present invention include an aqueous dye ink in which a water-soluble dye is dissolved in an aqueous solvent, an oil-based dye ink in which an oil-soluble dye is dissolved in an oil solvent, and an aqueous solvent. And a water-based or oil-based pigment ink in which a pigment is dispersed in an aqueous solvent or an oil-based solvent. Representative compounds used as solvents include, for example, water, alcohols (eg, methanol, ethanol, propanol), aliphatic hydrocarbons, aromatic hydrocarbons, naphthenic hydrocarbons, olefinic hydrocarbons, fatty acids and fatty acids Esters, benzoic esters, phthalic esters, amides (eg, dimethylformamide, dimethylacetamide, etc.), ketones or keto alcohols (eg, acetone, methyl ethyl ketone, cyclohexanone, diacetone alcohol, etc.), polyalkylene glycols (eg, Polyethylene glycol, polypropylene glycol, etc.), alkylene glycols (eg, ethylene glycol,
Propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, etc.), glycerin, ethers (for example, anisole, ethylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol methyl) (Or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc.)
Usually, some mixtures thereof are used.

The pigment is a white or colored powder insoluble in water, oil and the like. Dyes include direct dyes, acid dyes, reactive dyes, basic dyes, disperse dyes, and the like. These dyes are used alone or in combination of two or more in a form dissolved or dispersed in a solvent. The disperse dye refers to a dye that is soluble in oil but insoluble or hardly soluble in water and used for dyeing in a system dispersed in water.

These pigments and disperse dyes are mixed with a dispersant and other additives necessary for various desired purposes, and used after being dispersed by a disperser. As the dispersant, for example, a surfactant is used, and as the surfactant, any of a cationic, anionic, amphoteric, or nonionic can be used. Further, it is preferable to add a surfactant to the ink for the inkjet head in addition to the dispersant in order to accelerate the penetration of the ink droplets into the medium. The surfactant is not particularly limited as long as it does not adversely affect the storage stability or the like of the ink. For example, the same surfactant as used as a dispersant may be used. it can.

The ink used in the ink jet head of the present invention may contain an electric conductivity regulator. Examples of the electric conductivity regulator include inorganic salts such as potassium chloride, ammonium chloride, sodium sulfate, sodium nitrate, and sodium chloride, and water-soluble amines such as triethanolamine.

The ink used in the ink jet head of the present invention is required for the purpose of improving ejection stability, compatibility with a print head or an ink cartridge, storage stability, image storability, and other various properties. Depending on,
Further, a viscosity adjuster, a specific resistance adjuster, a film forming agent, an ultraviolet absorber, an antioxidant, an anti-fading agent, a rust inhibitor and the like can be added.

The ink-jet head of the present invention can be prepared by using various compounds as they are in addition to ordinary printing inks.
Or it can be dissolved or dispersed in a solvent and ejected,
It can be applied to the production of color filters for liquid crystals, the production of organic EL displays, and the like.

[0069]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the ink jet head and the method of manufacturing the ink jet head according to the present invention will be described, but embodiments of the present invention are not limited thereto.

(First Embodiment) FIG. 1 is a perspective view of a shear mode ink jet head, FIG. 2 is a view showing deformation of a piezoelectric element, and FIG. 3 is a partial cross section including an adhesive layer. FIG.

The ink jet head 1 is provided on a substrate 2
A plurality of grooves 2a are formed by attaching the polarized piezoelectric elements 2b, and electrodes 3 (see FIGS. 2 and 3) are provided inside the piezoelectric elements 2b serving as both partition walls of the grooves 2a, and a cover substrate 4 (see FIG. 3) To cover the outlet of the groove 2a with a nozzle plate 5, and cover the inlet with a supply plate 6, which is a member for restricting the flow of ink, to generate energy for discharging ink. A plurality of pressure chambers A and air chambers B are alternately formed, and an ink supply unit 7 is connected to the supply plate 6 side.

The nozzle plate 5 has a nozzle hole 5 a at a portion corresponding to the pressure chamber A. This nozzle hole 5a
Is preferably formed so as to be thin in the ejection direction, since the flow resistance of the ink is reduced and bubbles are easily discharged. In the supply plate 6, an ink inlet 6a is formed at a portion corresponding to the pressure chamber A.

It is preferable that the size of the ink inlet 6a is the same as the cross section of the pressure chamber, because air bubbles do not stagnate here. However, by squeezing the ink inlet 6a, the vibration of the pressure wave of the ink in the pressure chamber is reduced. In addition, the vibration of the ink meniscus in the nozzle hole can be suppressed, and the state of the ink in the pressure chamber and in the nozzle hole after the ink is ejected quickly returns to the initial state. It is preferable that the size of the opening 6a is the same as the size of the nozzle hole, because the driving becomes stable.

The groove 2a preferably has a length of about 0.5 to 10.0 mm, a depth of about 50 to 1000 μm, and a width of about 10 to 1000 μm, and is provided at twice the printing density. For example, if you want to print at 180 DPI, use 25400/36
0 is provided every 70 μm. It is preferable that the groove width of the air chamber B is smaller than the groove width of the pressure chamber A because the nozzle density can be increased. However, it is preferable to appropriately select the groove width of the air chamber as needed.

As described above, the substrate 2, the polarized piezoelectric element 2
b, a cover substrate 4, a nozzle plate 5, and a supply plate 6 constitute a head body, and a pressure chamber A is provided in the head body.
And a plurality of air chambers B are alternately formed by partitioning the partition wall with the piezoelectric element 2b. The head body has a nozzle hole 5a for discharging ink on the outlet side of the pressure chamber A,
An ink inlet 6a is provided on the inlet side of the pressure chamber A at a position facing the nozzle hole 5a, and a pressure chamber A and an ink flow path for supplying ink from the ink inlet 6a to the nozzle hole 5a are formed.

The formation of the electrode 3 of the ink jet head is performed as follows.
For example, after the piezoelectric element 2a is attached to the base material 2 and a protective film is provided on the top of the piezoelectric element 2a, the metal serving as an electrode is evaporated from an evaporation source in a plane that forms a certain angle with the extended surface of the groove partition wall. A metal is vapor-deposited on the entire surface of the piezoelectric element, and after vapor deposition of the metal, the protective film is removed to form the electrode 3. By doing so, the electrode 3 can be easily formed on the groove partition wall.
Examples of the metal serving as an electrode include gold, silver, aluminum,
Palladium, nickel, chromium, tantalum, titanium and the like can be used. In particular, gold, aluminum, and nickel-chromium alloys are preferable in terms of electrical characteristics, corrosion resistance, and workability. Alternatively, gold, silver, copper, and nickel electrodes may be formed by electroless plating.

In order to form connection electrodes for mutually connecting the electrodes 3 separately formed on the left and right partitions (piezoelectric elements) of the pressure chamber A and the air chamber B, for example, ink is supplied after the cover substrate 4 is joined to the piezoelectric element 2b. The side end surface and the upper surface of the cover substrate 4 are masked with a photosensitive resin layer, and one end of the groove bottom wall portion of the base material 2 is vapor-deposited to form connection electrodes communicating with the electrodes 3 provided on both partition walls inside each groove. This makes it possible to easily form connection electrodes that communicate with the electrodes 3 and 3 provided on both partition walls inside each groove.

Then, a polyparaxylylene film (hereinafter, referred to as a parylene film) is applied to the surfaces including the electrodes 3 and 3 provided on both partition walls inside each groove and the connection electrode, and the electrodes 3 and 3 and the connection are formed. The electrodes can be insulated. This is the pressure chamber A
When a voltage is applied to the electrodes and conductive ink is used, it is possible to prevent short-circuiting and inability to eject ink, or electrolysis of the ink to generate bubbles or corrode the electrodes. It is. It is preferable to use a parylene film as the insulating film. This parylene film is formed by CVD using a solid diparaxylylene dimer as an evaporation source.
(Chemical vapor Depositio
n). That is, the diradical paraxylylene generated by the vaporization and thermal decomposition of the diparaxylylene dimer is adsorbed on the head substrate and undergoes a polymerization reaction to form a film.

When air bubbles enter the pressure chamber provided with the parylene film, they adhere to the surface of the parylene film, stick, and are hardly removed. For this reason, it is preferable that the surface of the parylene film is subjected to oxygen plasma treatment to make it hydrophilic.

In the present embodiment, the pressure chamber A
And the air chamber B are partitioned by partition walls, and a plurality of the chambers are alternately formed. The influence of the deformation of the piezoelectric element 2a is blocked by the air chamber B and does not reach the other pressure chambers A. It can discharge and can be driven at a high frequency. However, without providing the air chamber B, the pressure chambers A can be driven out of phase so that the adjacent pressure chambers A are not simultaneously discharged. Further, by forming a straight ink flow path for supplying ink from the ink introduction port 6a to the nozzle hole 5a in the pressure chamber A, since the ink flow path has no bent portion, it is necessary to prevent air bubbles from stagnating here. However, a configuration in which an ink inlet is provided in a cover substrate or a base material is also possible.

The piezoelectric element used in the ink jet head 1 of this embodiment is made of lead zirconate titanate (trade name P
ZT) is preferred because of its high packing density, large piezoelectric constant, and good workability. When the temperature is lowered after sintering, the crystal structure of the PZT suddenly changes, resulting in a collection of fine dipole-shaped crystals in which atoms are shifted, one side is positive, and the other side is negative. Since such spontaneous polarization has a random direction and the polarities cancel each other, further polarization processing is required.

In the polarization treatment, a thin plate of PZT is sandwiched between electrodes,
It is immersed in silicon oil and polarized by applying a high electric field of about 10 to 35 kv / cm. When a voltage is applied to the polarized PZT at right angles to the polarization direction as shown in FIG. 3, the piezoelectric element (P
The partition wall of ZT) is sheared obliquely in a U-shape due to the piezoelectric sliding effect, the volume of the pressure chamber A expands, and ink is supplied from the ink supply unit 7 to the pressure chamber A. At this time,
A negative pressure wave is generated in the pressure chamber and propagates through the ink,
After a lapse of time L / v (L: length of the pressure chamber, sound velocity in v ink), the pressure wave reaches the end of the pressure chamber and is reflected, and the phase is inverted to become a positive pressure wave. At this time, when the voltage applied to the electrodes is dropped to the ground, the deformation of the partition walls of the piezoelectric element is eliminated, the volume of the pressure chamber A is reduced, and pressure is applied to the ink. When the inverted positive pressure wave and the pressure from the wall are added, a high pressure is applied to the ink, and the ink is ejected from the nozzle hole 5a. As the amount of deformation of the piezoelectric element increases, the force applied to the ink increases, the ejection speed of the ink droplets increases, the straightness of ejection increases, and the resolution of an image improves.

To increase the deformation of the piezoelectric element, 1
As shown in FIG. 2A, using two PZTs and providing electrodes in the upper half thereof and deforming the upper half, two PZTs as shown in FIG. Joined so that the polarization directions are opposite, provided electrodes on the entire surface, and provided two PZs.
It is preferable to apply a voltage to T before use. This is a chevron type device disclosed in JP-B-6-61936 and JP-B-6-61936.
No.-6375. When two PZTs are joined together so that their polarization directions are opposite, the shear deformation is doubled compared to the case of one PZT, so the drive voltage is １ ／ to obtain the same deformation. No. When joining two PZTs polarized in opposite directions, joining them to the substrate to form a partition, and applying a voltage to the electrodes of the pressure chamber,
It is preferable that an electrode be provided on the entire surface of the partition and not provided on the bottom of the groove.

In this embodiment, as shown in FIG. 3, a piezoelectric element 2b in which two polarized piezoelectric elements are joined with an adhesive 80 is used, and the piezoelectric element 2b is joined to the base material 2 with an adhesive 8. To form an electrode by forming metal by depositing metal on the side surface of the partition, and then covering the head body with a cover substrate 4 by bonding with an adhesive 8. I have.

In the bonding between the piezoelectric elements by the adhesive 80, it is preferable that the thickness of the cured adhesive layer be 10 to 15 μm or less, so that the reliability of the bonding between the two piezoelectric elements is reduced. Thus, ink leakage hardly occurs, and the risk of hindering the connection of the electrodes can be reduced. Also,
In bonding with the adhesive 8 between the base material and the piezoelectric element and bonding with the adhesive 8 between the cover substrate and the head main body, it is preferable that the cured thickness of the adhesive layer is 2 μm or less, whereby the piezoelectric element partition wall is formed. Can be reduced.

Thus, the piezoelectric element 2b in which the two piezoelectric elements are bonded by the adhesive so that the polarization directions are opposite to each other.
Is bonded to the base material 2 with an adhesive to form a groove 2a.
After the electrodes 3 are provided on both partition walls of the groove 2a, they are bonded with an adhesive so as to cover the ceiling of the groove 2a with the cover substrate 4, and the entrance of the groove 2a is formed.
The outlet is joined with an adhesive so as to be closed by a supply plate 6 having an ink inlet and a nozzle plate 5 having a nozzle hole.

The base material 2 and the cover substrate 4 are made of, for example, depolarized PZT or forsterite (2MgO.SiO).
_2), Photoveel (special ceramic) containing fluorine phlogopite and zirconia as a main component an idiot acid glass Sumitomo Metals ho tons ceramic Co., ternary ceramic MgO-TiO ₂ -CaO, BaTiO _3, sintered alumina, fused silica , Zirconia, stabilized zirconia, partially stabilized zirconia, zirconia reinforced ceramics, tetragonal zirconia polycrystal, or the like.

The nozzle plate 5 and the supply plate 6 are made of, for example, metal or resin such as stainless steel, polyimide, polysulfone, and polyetherethersulfone. The nozzle plate 5 and the supply plate 6 may form a nozzle hole or an ink inlet by laser perforation or mechanical perforation before bonding, or may form a nozzle hole or an ink inlet by laser perforation after bonding. In addition, the surface on the discharge side of the nozzle plate 5 is often subjected to ink-repellent treatment. However, if the adhesive surface before bonding is subjected to ink-repellent treatment, there is a possibility that sufficient bonding with the adhesive may not be performed. When performing the ink-repellent treatment, it is preferable that the adhesive surface is not subjected to the ink-repellent treatment.

In any case, when bonding with an adhesive is performed, it is preferable that the surface to which the adhesive is applied is subjected to a hydrophilic treatment to increase wettability. As the treatment for increasing the wettability, washing with a surfactant, an acid or an alkali, ozone treatment, corona discharge treatment, and plasma treatment are preferable.

In the present embodiment, an adhesive 8 for bonding between the base material and the piezoelectric element and for bonding between the cover substrate and the head body, and an adhesive 8 for bonding between the piezoelectric element and the piezoelectric element.
In addition to the use of an adhesive containing a polysiloxane-modified epoxy resin, an adhesive containing a polysiloxane-modified epoxy resin is also used as an adhesive for joining the nozzle plate 5 and the supply plate 6. The head was manufactured. Depolarized PZT was used for the base material and the cover substrate, and polyimide was used for the nozzle plate 5. Specific examples of the formulation of the adhesive containing the polysiloxane-modified epoxy resin will be described below.

80% of equivalent weight of dicyandiamide as a curing agent as a main agent of the structural formula 1 (a mixture mainly composed of n = 1 and m = 10 to 30), and 4% of an adduct of a phenol novolak type epoxy resin of diethylenetriamine as a reaction accelerator.
By weight percent, the adhesive A was used, and the structural formula 1 (n = 2,
m = 10 to 30) and an unmodified bisphenol A type epoxy resin (n = 1) in a ratio of 1: 1.
Adhesive B was prepared by adding 0% of an adduct of phenol novolak type epoxy resin of diethylenetriamine as a reaction accelerator by 4% by weight. The viscosity of the adhesive A was 30,000 centipoise at 25 ° C., and the viscosity of the adhesive B was 50,000 centipoise at 25 ° C.

One member to be joined with each of the adhesives A and B is applied by a screen printing method, and the temperature is raised at a rate of 2 ° C./min to 80 ° C.
After the temperature has risen to 30 minutes, the temperature is
Staged. Then, after cooling to room temperature, it is superimposed on the other member, heated to 100 ° C. at a rate of 1 ° C./min while applying a pressure of 1 kg / cm ² , and then cooled to 30 ° C.
This temperature was maintained for a minute to cure. Cool after curing,
When the dimensions were measured, the members were joined while maintaining the dimensions at room temperature, and there was no warpage or displacement. Also, no protrusion of the adhesive was observed. An ink jet head having a small pressure loss due to the deformation of the adhesive and a high ejection efficiency was obtained.

In order to examine the ink resistance of the ink jet head manufactured in this manner, the adhesives A and B, which are immersed in the ink for a long time and the adhesives partially contact the ink, are used.
The ink resistance of each adhesive was evaluated from the rate of change when the weight change due to swelling with the solvent in the ink was measured. As a result of an accelerated test of immersion in various solvents at 60 ° C. for one week (168 hours), it was found that if the weight change was 4% or less, it could withstand practical use especially for a long period of time.

The head was actually driven, and a durability test was performed. If it can be shot more than 10 ⁸ shots, it can be put to practical use, and if it can be shot more than 10 ¹⁰ shots, it is almost unnecessary to replace the head, which is preferable.

The results of the ink immersion test and the durability test are shown in Table 1 below together with Comparative Examples. × those not withstand at all practical, those capable of withstanding the once practical △, enough to bear practical use endure preferred ones ○, also sufficiently practical, most early Examination by degraded after durability test 10 ¹⁰ shots A more preferable one that maintained the state and did not deteriorate was ◎
And

[0096]

[Table 1]

In this embodiment, when a conductive ink is used and a drive voltage is applied to an electrode that comes into contact with the ink, an electrode protective film is required. Therefore, an insulating film such as a parylene film may be formed. . If the parylene film is entirely covered with the parylene film by the vapor phase synthesis method (CVD method) after the bonding with the adhesive and in contact with the ink at the same time as protecting the electrodes, the adhesive portion is also protected by the parylene film. The ink resistance of the adhesive itself is not always necessary. However, an opening is necessary to form a parylene film by a vapor phase synthesis method, and in order to complete a pressure chamber that generates pressure for discharge, an adhesive of at least the last member to be bonded is Parylene films cannot be formed and protected by vapor phase synthesis. In the manufacture of pressure chambers, the nozzle plate or the supply plate is often joined last.

On the other hand, when discharging non-conductive ink or when the electrodes in the pressure chamber are always driven to the ground potential, it is not always necessary to provide a protective film in the pressure chamber.

In this embodiment, the adhesive portion in contact with other ink was coated with a parylene film before joining the nozzle plate, and the electrode in the pressure chamber was always driven at the ground potential without coating. If both tests were done,
No difference was observed between the case where only the bonded portion of the nozzle plate portion touched the ink and the case where the other bonded portion also touched the ink.

The diameter of the nozzle hole of the nozzle plate is 5 to 50 μm.
If the adhesive adheres to the inside of the nozzle hole, it will not be ejected or the ejected ink droplets will be small, which will have a significant effect on the performance. A plurality of nozzle holes are formed in the nozzle plate corresponding to the plurality of pressure chambers. Therefore, the positional accuracy required for bonding the nozzle plate with the adhesive varies depending on the diameter of the nozzle hole, the size of the ink flow path or the pressure chamber on the surface to which the nozzle plate is bonded, and the like. The following accuracy is preferable. The interval between the nozzle holes is 10 to 1000 μm, and many holes are provided with approximately 64 to 1024 nozzle holes, but the number of nozzles tends to increase. In the method of printing the entire width of the paper to be printed at once, for example, a nozzle having 7000 nozzles and an overall width of 30 cm is known. It corresponds to 33 ppm.

Furthermore, considering that the coefficient of thermal expansion of stainless steel or the like used for the nozzle plate is at least about 10 ppm per 1 ° C. even when it is small, the joining between members having different coefficients of thermal expansion is not effective at the time of bonding. This shows how it is difficult to maintain the positional accuracy of bonding by heating. Therefore, in the present embodiment, bonding is performed through a B-stage process using an adhesive containing a polysiloxane-modified epoxy resin. By applying an adhesive to one of the members, heating and semi-curing to form a B-stage, the fluidity of the adhesive is lost and the adhesive becomes a sticky state. When this is cooled to room temperature and overlapped with the other member, the relative position of the two members is fixed by the adhesive force of the B-staged adhesive. Absent. At this time, the B-staged adhesive does not overflow or flow out because it has no fluidity. Thereafter, by heating the two superimposed members while applying pressure, the adhesive is cured to complete the joining.

In this embodiment, when the temperature of the piezoelectric element to be joined rises, the piezoelectric effect of the piezoelectric element is lost.
It is not preferred that the curing temperature be higher than a certain temperature. The temperature at which the piezoelectric effect is lost varies depending on the type, composition, and manufacturing method of the piezoelectric element, but in general, the higher the efficiency of the piezoelectric effect, the lower the temperature. Since the efficiency of the piezoelectric effect is reduced when the temperature exceeds 120 ° C. in the piezoelectric element that can obtain the ink ejection efficiency preferable for the ink jet head of the present embodiment, the B-stage and curing of the adhesive are performed at 120 ° C.
C. or lower, and the adhesive containing the polysiloxane-modified epoxy resin of the present embodiment can realize the B-stage and curing at such a low temperature.

Further, since the pressure chamber discharges ink at a pressure generated by the piezoelectric element, if the pressure chamber is deformed by the pressure, the pressure at which the ink is discharged escapes, so that the ink can be discharged efficiently. Can not. If the elastic modulus of the adhesive used for joining the plurality of members constituting the pressure chamber is low, the pressure chamber is deformed, and the efficiency of the inkjet head is reduced. Therefore, the adhesive used for joining the members constituting the pressure chamber preferably has a high modulus of elasticity after curing, and more preferably 100 kg / cm ² or more. The adhesive containing the polysiloxane-modified epoxy resin of the present embodiment also satisfies this elastic modulus.

In this embodiment, an example is shown in which the base member 2 and the piezoelectric element 2b are formed of different members and both are joined by an adhesive. For example, two polarized PZT substrates are bonded together. It is also possible to adopt a configuration in which a head substrate of the piezoelectric element is prepared and the groove 2a is formed by a diamond grindstone or the like. In this case, the head structure becomes simple.

(Second Embodiment) FIG. 4 is a schematic sectional view of an ink jet head of a type in which the volume of a pressure chamber is changed by expansion and contraction of a piezoelectric element provided on the wall of the pressure chamber.

More specifically, for example, a plurality of nozzle holes 15
and a metal supply plate 16 provided with a plurality of ink introduction ports 16a, which is a member provided on the ink introduction side of the pressure chamber A to restrict the flow of ink. Are laminated and joined with the flow path plate 12a interposed therebetween, thereby forming an ink flow path for guiding the ink to the nozzle hole 15a and an ink supply flow path for guiding the ink to the ink introduction port 16a, respectively. At the very least, the plates 12b, 1 made of metal or synthetic resin
The nozzle hole 15a and the ink introduction port are formed by superposing and bonding and integrating a member having a plurality of openings corresponding to the respective nozzle holes 15a and the ink introduction port 16a, which is formed by a laminate of 2c and 12d. 16a, pressure chambers A are respectively formed behind the pressure chambers A.
The piezoelectric element 13 is formed by fixing the piezoelectric element 13 to the wall portion.

In the ink jet head 10, the ink supplied to the pressure chamber A is discharged through a nozzle hole 15 a provided in the nozzle plate 15. More specifically, a nozzle plate 15 and a supply plate 16, which is a member having an opening on the ink introduction side of the pressure chamber and restricting the flow of ink, are provided with a flow path plate 1 therebetween.
2a are sandwiched therebetween, and are integrally joined by an adhesive.

The nozzle plate 15 has a plurality of (not shown) nozzle holes 15a for discharging ink. The supply plate 16 and the flow path plate 12a have respective nozzle holes 15a. At a corresponding position, a through hole penetrating in the plate thickness direction is formed with an inner diameter larger than the nozzle hole 15a by a predetermined dimension.

Further, the supply plate 16 has a plurality of ink introduction ports 16a (orifice holes) (not shown).
The window formed in the flow path plate 12a is provided with the nozzle plate 15 and the supply plate 16
By being covered from both sides, an ink supply channel is formed between the nozzle plate 15 and the supply plate 16 so as to communicate with each ink inlet 16a. The supply plate 16 is provided with a supply port for supplying ink guided from the ink tank to the ink supply flow path.

Each of the plates 15, 16, 12a is
In order to form the nozzle hole 15a and the ink inlet 16a with high dimensional accuracy, it is generally preferable to use plastic or a metal such as nickel or stainless steel. Further, as shown in the drawing, it is desirable that the ink introduction port 16a is formed to have a tapered shape whose diameter decreases in the ink circulation direction.

On the other hand, on the opposite side of the supply plate 16, the closing plate 12d and the connection plate 12b are integrally formed with a structure in which the closing plate 12d and the connection plate 12b are overlapped with the spacer plate 12c interposed therebetween.

The supply plate 1 is connected to the connection plate 12b.
The communication opening is formed at a position corresponding to the through hole and the ink introduction port 16a formed at 6.

A plurality of long rectangular windows are formed in the spacer plate 12c. The spacer plate 12c is opened such that each communication opening provided in the connection plate 12b is opened for each of the windows.
Are superimposed on the connection plate 12b.

On the surface of the spacer plate 12c opposite to the side on which the connection plate 12b is overlaid, a closing plate 12d is overlaid, and the opening of the window is covered with the closing plate 12d. . As a result, a pressure chamber A for ink communicated to the outside through each communication opening is formed.

Closing plate 12d, spacer plate 1
2c and the connection plate 12b are preferably made of ceramics. As the material of this ceramic, it is preferable to use alumina, zirconia, or the like from the viewpoint of moldability and the like. The plate thickness of the closing plate 12d is preferably 50 μm or less, more preferably about 3 to 12 μm, the plate thickness of the connection plate 12b is preferably 10 μm or more, more preferably 50 μm or more, and the plate thickness of the spacer plate 12c is preferably 50 μm or more. More preferably 100μ
m or more.

The pressure chamber A thus formed can be formed as an integrally fired product of ceramics, but may be used by bonding each plate with an adhesive.

A piezoelectric element 13 is provided on the outer surface of the closing plate 12d at a position corresponding to the pressure chamber A of each ink.
Is provided. The piezoelectric element 13 is formed by forming a piezoelectric operating portion including a lower electrode 13a, a piezoelectric element film 13b, and an upper electrode 13a on a closing plate 12d by a film forming method.

In this case, as the closing plate 12d,
It is preferable to use a ceramic substrate containing zirconium oxide as a main component.

By adding and containing one compound of yttrium oxide, cerium oxide, magnesium oxide, and calcium oxide alone or in combination,
Zirconium oxide is partially or completely stabilized. The content of each compound is 2 mol% to 7 mol% for yttrium oxide and 6 mol% to 1 mol% for cerium oxide.
5 mol%, magnesium oxide and calcium oxide are preferably 5 mol% to 12 mol%.
Particularly, it is preferable to use yttrium oxide as the partial stabilizer, and in that case, it is desirable that the content be 2 mol% to 7 mol%, more preferably 2 mol% to 4 mol%. Zirconium oxide to which yttrium oxide is added or contained in such a range is partially stabilized in a main crystal phase of tetragonal or a mixed crystal mainly composed of cubic and tetragonal, thereby giving excellent substrate characteristics.

Electrode films 13a, 13 constituting the piezoelectric operating portion
The material of a is not particularly limited as long as it is a conductor that can withstand a heat treatment temperature and a high-temperature oxidizing atmosphere at about the baking temperature. For example, it may be a simple metal or an alloy, and The mixture may be a mixture of ceramics, glass, or the like, a metal or an alloy, or may be a conductive ceramic. Preferably, platinum, palladium,
High melting point noble metals such as rhodium, or silver-palladium,
An electrode material mainly containing an alloy such as silver-platinum or platinum-palladium is used.

Preferably, PZT is used as the material of the piezoelectric element film 13b constituting the piezoelectric operating section.

The closing plate 12d, the spacer plate 12c, and the connection plate 12b, on which the piezoelectric element 13 is integrally provided, overlap the supply plate 16 with the supply plate 16 as shown in FIG. And integrated using an adhesive. Piezoelectric element 13
By the operation described above, an ink jet head 10 is formed in which the ink guided through the ink supply flow path is supplied to the pressure chamber A from the ink introduction port 16a and is discharged from the nozzle hole 15a through the through hole.

In this embodiment, the adhesive for joining the nozzle plate 15 to the flow path plate 12a, joining the supply plate 16 to the flow path plate 12a, and joining the supply plate 16 to the connection plate 12b include: An ink jet head was manufactured in the same manner as in the first embodiment, using the same adhesive containing the polysiloxane-modified epoxy resin as in the first embodiment. The ink jet heads thus manufactured were joined while maintaining the dimensions of each member at room temperature, and no warpage or displacement occurred. Also, no protrusion of the adhesive was observed. Further, the evaluation results of the ink resistance were the same as those in the first embodiment.

In this embodiment, since there are no electrodes in the pressure chamber, there is no need to provide a protective film such as a parylene film as in the first embodiment. On the contrary, it is preferable to use an adhesive having high ink resistance, and this embodiment realizes this. Thus, the pressure chamber was not deformed by the pressure generated by the piezoelectric element and the pressure for discharging the ink did not escape, and the ink could be discharged efficiently. In addition, when the adhesive leaks or flows into the pressure chamber to block the pressure chamber, narrow the space, or change the volume, the flow of the ink changes or the pressure applied to the ink changes to affect the ejection of the ink. There was nothing.

Further, the temperature at the time of bonding did not affect the piezoelectric element, and the piezoelectric effect of the piezoelectric element was not lost. Here, the closing plate 12d provided with the piezoelectric element is
Similarly, the same result could be obtained when bonding to the spacer plate 12c and bonding to the connection plate 12b using an adhesive containing a polysiloxane-modified epoxy resin.

(Third Embodiment) FIG. 5 shows an ink jet head of the same type as the second embodiment in which the volume of the pressure chamber is changed by expansion and contraction of a piezoelectric element provided on the pressure chamber wall, and has a different structure. FIG.

The base 21b has a protruding portion formed at one end thereof, at the lower side in the figure, for fixing a piezoelectric element 23 described later, and a pressure chamber A and a piezoelectric element 23 at the upper end surface.
Is fixed. The diaphragm 24 is
A concave portion is formed near the piezoelectric element 23 so as to easily respond to vibration of the piezoelectric element 23. On the surface of the vibration plate 24, a spacer member 22 serving as a supply plate having a flow path forming member and an ink introduction port 26a is fixed, and a region facing the piezoelectric element 23 defines a pressure chamber in cooperation with the vibration plate 24. Although not shown, the ink supply port 26a on the ink supply side has a shape in which the flow path is narrowed in the direction of the pressure chamber A so as to restrict the flow of ink. A nozzle plate 25 is fixed to the surface of the spacer member 22, and a plurality of nozzle holes 25a are provided in accordance with the arrangement of the piezoelectric elements 23 in which a piezoelectric material and a conductive material are alternately stacked in layers. The ink supply side also has an ink supply section 27 formed by sealing an opening from a portion of the nozzle plate 25 where the nozzle holes 25a are not provided.

The piezoelectric element 23 has one end fixed to the diaphragm 24 and the other end side fixed to the protrusion of the base 21b. The lower end of the base 21b is fixed to the fixing member 21a. The fixing member 21a supports the vibration plate 24, the spacer member 22, and the nozzle plate 25, and
The free end (the upper end in the figure) of the piezoelectric element 23 is in contact with the diaphragm 24 via 1b. As is apparent from the drawing, the base 21b is configured such that one end thereof substantially matches the end surface of the piezoelectric element 23 on the free end side, and the other end protrudes from the fixed end side of the piezoelectric element 23. You. In the ink jet head 20 having such a structure, when a voltage is applied to the electrodes provided on the piezoelectric element 23, the piezoelectric element 23 expands in the axial direction, and the diaphragm 24 fixed to the tip of the piezoelectric element 23 expands. The pressure chamber A is compressed by being displaced in the direction of 25. The ink that has received the pressure due to the decrease in the volume of the pressure chamber A flies as an ink droplet from the nozzle hole 25a.

In the present embodiment, the nozzle plate 25
And a spacer 22 which also serves as a member for regulating the flow of ink provided with an ink introduction port, and the spacer 2
An ink jet head was manufactured in the same manner as in the first embodiment, using an adhesive containing the same polysiloxane-modified epoxy resin as in the first embodiment as the adhesive for bonding the diaphragm 2 and the diaphragm 24. . The ink jet heads thus manufactured were joined while maintaining the dimensions of each member at room temperature, and no warpage or displacement occurred. Also, no protrusion of the adhesive was observed. Further, the evaluation results of the ink resistance were the same as those in the first embodiment.

In this embodiment, similarly to the second embodiment, since there is no electrode in the pressure chamber, there is no need to provide a protective film such as a parylene film. And an adhesive having high ink resistance. As a result, the pressure chamber is not deformed by the pressure generated by the piezoelectric element, and the pressure for discharging the ink does not escape, and the ink can be discharged efficiently. There was no change in the flow of the ink or change in the pressure applied to the ink due to the blockage or narrowing of the chamber or the change in the volume.

Further, in this embodiment, since the piezoelectric element 23 in which the piezoelectric material and the conductive material are alternately laminated in layers is used, the energy efficiency is extremely high.
Since the piezoelectric element 23 is fixed to the base 21b, a large strength is not required for the piezoelectric element 23 due to the strength of the base 21b, and the diaphragm 24 and the base 21b are connected via the fixing member 21a. Since the base 21b is fixed relative to the fixing member 21a, the piezoelectric element 2 is fixed.
3 can be brought into contact with the diaphragm 24 with high positional accuracy, and the use of an adhesive containing a polysiloxane-modified epoxy resin as the adhesive in contact with the ink can improve the performance of the inkjet head and reduce costs. You can do it.

(Fourth Embodiment) FIG. 6 is a schematic perspective view of a thermal type ink jet head.

The ink jet head of this embodiment is
For example, a top plate 44 provided with a portion forming an ink supply unit 47 and a groove 42 a forming a pressure chamber is provided with an ink introduction port 46.
a supply plate 46 having a
The ink supply unit 47 and the pressure chamber A are formed by joining the heater board 42 provided with the supply plate 46 and the top plate 44 to which the supply plate 46 is joined, and then the opposite side of the pressure chamber A from the ink supply unit 47 side. The nozzle plate 45 having the nozzle holes 45a is joined so as to cover the opening of the ink jet head 40. In the ink jet head 40 having such a configuration, the ink is vaporized or bubbles are generated by discharging the ink from the nozzle holes 45a by energizing the discharge heater 49 serving as the heating element to rapidly generate heat in the heating element. In this method, thermal energy is used to fly ink droplets.

In the present embodiment, the bonding for joining the supply plate 46 to the top plate 44, joining the top plate 44 and the heater board 42, and joining the nozzle plate 45 to the top plate 44 and the heater board 42 is performed. An ink jet head was manufactured in the same manner as in the first embodiment, using an adhesive containing the same polysiloxane-modified epoxy resin as in the first embodiment. The ink jet heads thus manufactured were joined while maintaining the dimensions of each member at room temperature, and no warpage or displacement occurred. Also, no protrusion of the adhesive was observed. Further, the evaluation results of the ink resistance were the same as those in the first embodiment.

In this embodiment, as in the second and third embodiments, since there is no electrode in the pressure chamber, there is no need to provide a protective film such as a parylene film, and the adhesive in the portion in contact with the ink is used. In this case, an adhesive having high ink resistance is used for the joining by the method. As a result, there is no deformation of the pressure chamber, and stable ejection of ink can be realized for a long period of time.Also, the adhesive protrudes or flows into the pressure chamber to block the pressure chamber, narrow the pressure chamber, or change its volume. Also, there was no adverse effect on ink ejection due to a change in ink flow. Furthermore, the bonding position accuracy can be easily and accurately increased by using the B stage, and the positioning process and the assembling process can be simplified, so that the manufacturing cost can be reduced. As mentioned above,
In the present embodiment, an ink jet head that has a high pressure generated for ejection, is inexpensive, and easy to manufacture is obtained.

In the first to third embodiments, the power consumption is lower in principle than that of the type in which fine bubbles are generated by heating the heater disposed in the pressure chamber. It is.

[0137]

According to the first aspect of the present invention, it is possible to provide an ink jet head having resistance to various inks without sacrificing other characteristics.

According to the second aspect of the present invention, a curing reaction does not occur at room temperature, and the composition can be used as a one-part adhesive which can be stored in a state where a main agent and a curing agent are mixed in advance, so that the workability is excellent, and The adhesive is adhered after the agent is made into the B-stage, so that the adhesive can be adhered with a small amount of protrusion and with high adhesion position accuracy.

According to the third aspect of the present invention, it is possible to improve the wettability of the member on which the adhesive is applied. Further, by lowering the curing temperature at the time of bonding, the bonding strength can be increased without lowering the bonding position accuracy due to thermal expansion or deteriorating the piezoelectric element that generates ink ejection energy.

According to the fourth aspect of the present invention, the adhesion position of the nozzle plate is highly accurate, and the nozzle hole, the ink flow path,
It is possible to provide an ink jet head in which the adhesive does not protrude into the pressure chamber and the amount, speed, and ejection angle of the flying ink droplet are stable.

According to the fifth aspect of the present invention, it is possible to provide an ink jet head capable of stably driving at high speed by controlling the behavior of the ink in the nozzle and the pressure chamber.

According to the sixth aspect of the present invention, there is provided an ink jet head having a high efficiency by reducing the pressure loss by increasing the elastic modulus of the adhesive between members joined to form a pressure chamber. can do.

According to the seventh aspect of the present invention, it is possible to provide an ink jet head in which the pressure is generated by the deformation mode with high efficiency of the piezoelectric element and the generated pressure for ejection is high.

According to the eighth aspect of the present invention, it is possible to provide an ink jet head which generates a high pressure for ejection, is inexpensive and easy to manufacture.

According to the ninth aspect of the present invention, a pressure chamber is formed by cutting a groove in the piezoelectric element, so that an ink jet head which can be driven at high speed and is easily manufactured can be provided.

According to the tenth aspect, it is possible to provide a highly efficient ink jet head by increasing the deformation of the piezoelectric element.

According to the eleventh aspect of the present invention, it is possible to provide a method for efficiently manufacturing an ink jet head having high ink resistance, no protrusion or run-out of adhesive, and high positional accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shear mode type ink jet head.

FIG. 2 is a diagram illustrating deformation of a piezoelectric element of a shear mode ink jet head.

FIG. 3 is a partial cross-sectional view illustrating an adhesive layer of the shear mode ink jet head.

FIG. 4 is a schematic sectional view of an ink jet head of a type in which the volume of a pressure chamber is changed by expansion and contraction of a piezoelectric element provided on a pressure chamber wall.

FIG. 5 is a schematic cross-sectional view of another ink jet head that changes the volume of a pressure chamber by expansion and contraction of a piezoelectric element provided on a pressure chamber wall.

FIG. 6 is a schematic perspective view of a thermal type ink jet head.

[Explanation of symbols]

 1, 10, 20, 40 Inkjet head 2 Base material 2a, 42a Groove 2b, 13, 23 Piezoelectric element 3, 13a Electrode 4 Cover substrate 5, 15, 25, 45 Nozzle plate 5a, 15a, 25a, 45a Nozzle hole 6, 16, 46 Supply plate 6a, 16a, 26a, 46a Ink inlet 7, 27, 47 Ink supply part 8, 80 Adhesive 21a Fixing member 21b Base 22 Spacer member 24 Vibration plate 42 Heater board 44 Top plate 49 Discharge heater A Pressure chamber B Air chamber

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 163/00 B41J 3/04 103H 183/04 (72) Inventor Hiroshi Takeuchi 1 Sakuracho, Hino City, Tokyo Konica Corporation F-term (reference) 2C057 AF65 AF93 AG45 AG46 AG47 AP25 BA03 BA13 BA14 4J040 EC461 EK111 HC02 HC06 HC12 HC16 JB02 KA16 KA17 LA07 MA01 MA02 MA04 NA21 PA30 PA33

Claims (11)

[Claims] 1. An ink jet head in which at least two members are joined with an adhesive, wherein an adhesive containing a polysiloxane-modified epoxy resin is used as at least a part of an adhesive at a joint portion in contact with the ink. Inkjet head. 2. The ink jet head according to claim 1, wherein the adhesive containing the polysiloxane-modified epoxy resin contains dicyandiamide or a derivative of dicyandiamide as a curing agent. 3. The ink jet head according to claim 1, wherein the adhesive containing the polysiloxane-modified epoxy resin contains an aliphatic amine epoxy adduct as a reaction accelerator. 4. A nozzle plate formed with a nozzle for discharging ink and a pressure chamber for generating energy for discharging ink, wherein the polysiloxane-modified epoxy is provided at a joint between the nozzle plate and another member. An adhesive containing a resin is used.
3. The inkjet head according to any one of 3. 5. A pressure chamber for generating energy for discharging ink, wherein a member provided on an ink introduction side of the pressure chamber for restricting the flow of ink and a joining portion between the member and another member are provided. The inkjet head according to any one of claims 1 to 3, wherein an adhesive containing a polysiloxane-modified epoxy resin is used. 6. A pressure chamber for generating energy for discharging ink, wherein the pressure chamber is composed of a plurality of members, and a joining portion between at least two members of the plurality of members is provided at a joint portion between at least two members. The inkjet head according to any one of claims 1 to 3, wherein an adhesive containing a polysiloxane-modified epoxy resin is used. 7. A voltage is applied to a piezoelectric element formed outside the pressure chamber, and the piezoelectric element is expanded and contracted to deform, thereby generating energy for deforming the pressure chamber and ejecting ink. Claim 1 characterized by the fact that
7. The inkjet head according to any one of 6. 8. A method according to claim 1, wherein a heating element is provided in said pressure chamber, and said heating element is energized to vaporize ink to generate energy for discharging ink. 5. The ink jet head according to claim 1. 9. A method for generating energy for discharging ink by forming all or a part of a member constituting the pressure chamber with a piezoelectric element and applying a voltage to the piezoelectric element to cause a shear deformation. 7. The method according to claim 1, wherein
The inkjet head according to any one of the above. 10. The ink-jet apparatus according to claim 9, wherein the two piezoelectric elements polarized in directions different from each other are joined by an adhesive containing the polysiloxane-modified epoxy resin. head. 11. A method for manufacturing an ink jet head for joining at least two members constituting an ink jet head with an adhesive, wherein at least one of the members contains a polysiloxane-modified epoxy resin in order to join the two members. Applying the adhesive, heating the applied adhesive to form a B-stage, heating the adhesive while pressing the two members, and curing the adhesive to join the two members. A method for manufacturing an ink jet head, comprising: