JP2012183669A - Liquid ejection head and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid ejection head capable of enhancing bonding reliability.SOLUTION: An epoxy adhesive used as an adhesive contains (A) an epoxy resin monomer not having a hydroxyl group, (B) a hardener, and (C) a silane coupling agent (10 wt.%-30 wt.%) having a silanol group represented by a formula (1). The method for manufacturing the liquid ejection head includes a step of applying the epoxy adhesive in a state of being diluted with a diluting solvent to one of the members to be bonded, a step of evaporating the diluting solvent at reduced pressure, and a step of bonding two members to be bonded via the epoxy adhesive in a state of being humidified by a high humidity atmosphere. (In the formula, R1-R3 are hydrocarbon groups of 1-3C, R4 is an amino group, glycidyl group, epoxy group, hydrocarbon chain, or ether chain).

Description

  The present invention relates to a liquid discharge head and an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. An apparatus (ink jet recording apparatus) is known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials, resins and the like are also included. In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Conventionally, as a liquid discharge head, a nozzle plate in which a plurality of nozzles for discharging droplets are formed, a flow path plate that forms a liquid chamber in which the nozzles communicate with each other, and a partial wall surface of the liquid chamber are formed. A diaphragm member having a deformable vibration region, joined to a portion corresponding to a partition between a diaphragm member joined to a flow path plate, a driving column joined to the vibration region of the diaphragm member, and a liquid chamber of the diaphragm member 2. Description of the Related Art A piezoelectric head including a piezoelectric member having a non-driving column that is a supported column member is known.

  The nozzle plate, flow path plate, and diaphragm member of such a piezoelectric head are bonded with an adhesive. Conventionally, as an adhesive, an alicyclic epoxy resin and a bisphenol epoxy resin as an epoxy resin, and a photocation as a curing agent. A polymerization initiator and / or a thermal cationic polymerization initiator, containing at least an organosilicon compound as an additive, wherein the organosilicon compound is a compound that generates a silanol group by light irradiation and / or heating and / or hydrolysis. Known (Patent Document 1).

Japanese Patent No. 3986000

  Incidentally, water-based inks and oil-based inks are known as inks that are liquids used in image forming apparatuses. Ink has also been developed for curling in printing on paper media and printing on non-absorbing film media. For example, an anti-curl ink has a composition in which the moisture in the ink is suppressed and the solvent is increased, and this is an ink in which the characteristics of the water-soluble organic solvent appear stronger than the conventional aqueous solution. Also, the printing ink on the non-absorbing film medium is an ink to which a highly soluble solvent such as methylpyrrolidone is added, and has a higher attacking property on organic matter than the conventional aqueous ink. .

  As described above, the adhesive that joins the nozzle plate, the flow path plate, and the vibration plate member of the liquid discharge head is exposed to a wide variety of inks and is subject to high-frequency pressure fluctuations. For this reason, problems such as deterioration of the adhesive due to the ink, or the penetration of the ink into the bonding interface, the deterioration of the adhesive, and separation of the interface between the bonding members occur.

  For this reason, it is desired that the adhesive for joining the head components is resistant to the liquid to be used, and maintains a sufficient joining strength by minimizing the deviation due to penetration into the joining interface.

  The present invention has been made in view of the above problems, and an object thereof is to improve the bonding reliability.

In order to solve the above problems, a method of manufacturing a liquid ejection head according to the present invention includes:
At least two members: a nozzle plate on which nozzles for discharging liquid droplets are formed; a flow path plate that forms a liquid chamber that communicates with the nozzles; and a vibration plate member that forms a part of the wall surface of the liquid chamber. In the manufacturing method of the liquid discharge head bonded with an adhesive,
The adhesive is
(A) Epoxy resin monomer having no hydroxyl group (B) Curing agent (C) Silane coupling agent having a silanol group represented by formula (1) (10 to 30% by weight)

（ただし、式中、Ｒ１〜Ｒ３は、炭化水酸基（炭素数１〜３）、Ｒ４は、アミノ基,グリシジル基,エポキシ基,炭化水素鎖,エーテル鎖）
を含有するエポキシ接着剤であり、
前記エポキシ接着剤を、希釈溶剤で希釈した状態で接合する部材の一方の部材に塗布する工程と、
減圧下で前記希釈溶剤を蒸発させる工程と、
高湿度雰囲気で加湿した状態で、２つの接合する部材を前記エポキシ接着剤を介して接合する工程と、を行う
構成とした。

(In the formula, R1 to R3 are carbonized hydroxyl groups (1 to 3 carbon atoms), R4 is an amino group, glycidyl group, epoxy group, hydrocarbon chain, ether chain)
An epoxy adhesive containing
Applying the epoxy adhesive to one of the members to be joined in a diluted state with a diluent solvent;
Evaporating the diluent solvent under reduced pressure;
And a step of joining two members to be joined via the epoxy adhesive in a humidified atmosphere.

  Here, at least one member of the two members joined by the epoxy adhesive may be formed of SUS.

  Moreover, it can be set as the structure by which the silane coupling process is performed to at least one member of the two members joined by the said epoxy adhesive.

  The liquid discharge head according to the present invention is manufactured by the method for manufacturing a liquid discharge head according to the present invention.

  The image forming apparatus according to the present invention includes the liquid discharge head according to the present invention.

According to the method for manufacturing a liquid ejection head according to the present invention, (A) an epoxy resin monomer having no hydroxyl group, (B) a curing agent, and (C) a silane coupling agent having a silanol group represented by the formula (1). An epoxy adhesive containing (10 wt% to 30 wt%),
Applying the epoxy adhesive to one of the members to be joined in a diluted state with a diluent solvent;
Evaporating the diluent solvent under reduced pressure;
In a state humidified in a high humidity atmosphere, the step of joining two members to be joined via the epoxy adhesive is used. The separation due to penetration can be suppressed as much as possible to maintain a sufficient bonding strength, and the bonding reliability can be improved, and the life of the head is extended.

  Since the liquid discharge head according to the present invention is manufactured by the method for manufacturing a liquid discharge head according to the present invention, stable droplet discharge can be performed over a long period of time.

  According to the image forming apparatus of the present invention, since the liquid ejection head according to the present invention is provided, a high quality image can be formed by performing stable droplet ejection over a long period of time.

FIG. 4 is a cross-sectional explanatory view along a direction orthogonal to a nozzle arrangement direction showing an embodiment of a liquid discharge head according to the present invention. It is a section explanatory view showing an example of a direction which follows a nozzle arrangement direction similarly. It is sectional explanatory drawing which similarly shows the other example of the direction along a nozzle arrangement direction. 1 is an overall configuration diagram illustrating an example of an image forming apparatus according to the present invention. Similarly it is principal part plane explanatory drawing.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an embodiment of a liquid discharge head according to the present invention will be described with reference to FIGS. 1 is a cross-sectional explanatory diagram along a direction orthogonal to the nozzle arrangement direction of the liquid discharge head, and FIG. 2 is a cross-sectional explanatory diagram along the nozzle arrangement direction.

  The liquid discharge head includes a flow path plate (flow path member, liquid chamber substrate) 1 formed of a SUS substrate, a vibration plate member 2 bonded to the lower surface of the flow path plate 1, and an upper surface of the flow path plate 1. A pressurized liquid chamber (also referred to as a pressure chamber, a pressure chamber, a flow path, etc.) 6 as an individual flow path that communicates with a nozzle 4 that discharges droplets. A fluid resistance portion 7 also serving as a supply path for supplying ink that is liquid to the pressure liquid chamber 6 is formed, and ink is supplied to the plurality of pressure liquid chambers 6 from a common liquid chamber 8 of a frame member 17 described later. .

  Here, the flow path plate 1 is formed by machining a SUS substrate having a thickness of 50 μm using an acidic etching solution, such as etching or punching, so that each pressurized liquid chamber 6, the fluid resistance portion 7, and a damper chamber described later. Openings such as 20 are formed. For the flow path plate 1, for example, Si, Ni, 42 alloy, SUS304, or the like can be used.

  Further, a liquid-resistant thin film made of an organic resin film such as a titanium nitride film or polyimide may be formed on the surface of the flow path plate 1 in contact with the liquid. By forming such a liquid-resistant thin film, the flow path plate material is less likely to elute with respect to the liquid, and the wettability is improved, so that bubbles are less likely to stay and stable droplet ejection is possible.

  In the present invention, “layer” and “film” are used to mean all substantially flat structures.

  The diaphragm member 2 is joined to the flow path plate 1 with an adhesive 51. The diaphragm member 2 has a first layer 2a and a second layer 2b. For example, the diaphragm member 2 is formed by laminating and bonding the first layer 2a with a resin member such as polyimide and the second layer 2b with a metal member, or formed by a nickel electroformed metal plate, or the whole. A resin layer or the like can also be used.

  Here, Ni, 42 alloy, SUS304, or the like can be used as the metal member. Moreover, a rolled film etc. can also be used as a resin member. Furthermore, moisture permeation of the liquid can be reduced by forming a metal film such as SiO 2 or Ti on the surface. When the whole is a resin layer, the displacement efficiency is not hindered because the rigidity of the vibration region is lower than that of the metal layer. Further, when the flow path plate 1 is a metal, the bonding strength between the resin layer and the metal is higher than the bonding between the metals.

  Moreover, the process which shows affinity with respect to an adhesive agent can also be performed to the joining area | region with the piezoelectric member 12 mentioned later. As a treatment showing affinity, a hydroxyl group or a SiO2 thin film layer is formed. The SiO 2 thin film layer is formed by a method that allows film formation at a temperature that is relatively not heated, that is, does not cause thermal influence on the diaphragm member 3. For example, sputtering, ion beam vapor deposition, ion plating, CVD (chemical vapor deposition), P-CVD (plasma vapor deposition) and the like are suitable.

  When the diaphragm member 3 is formed of a resin layer, polyphenylene sulfide (PPS), other stretchable polymer materials such as polyimide (PI) resin, polyetherimide (PEI) resin, polyamidoimide (PAI) Resin, polyvalavanic acid (PPA) resin, borisulphone (PSF) resin, polyethersulfone (PES) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyolefin (APO) resin, polyethylene naphthalene A phthalate (PEN) resin, an aramid resin, a polypropylene resin, a vinylidene chloride resin, a polycarbonate resin, or the like can also be used.

  The nozzle plate 3 forms a large number of nozzles 4 having a diameter of 10 to 30 μm corresponding to the pressurized liquid chambers 6 and is bonded to the flow path substrate 1 with an adhesive 51. As this nozzle plate 3, what consists of metals, such as stainless steel and nickel, resin, such as a polyimide resin film, silicon | silicone, and those combinations can be used. Further, a water repellent film is formed on the nozzle surface (surface in the ejection direction: ejection surface) by a known method such as a plating film or a water repellent coating in order to ensure water repellency with ink.

  The diaphragm member 2 has a two-layer convex portion of the second layer 2b at the center of the diaphragm portion 2A, which is a deformable region formed by the first layer 2a corresponding to each pressurized liquid chamber 6. 2B is formed, and columnar driving columns 12A formed on the piezoelectric member 12 constituting pressure generating means (actuator means) are respectively joined to the convex portions 2B. Further, columnar non-driving columns 12B formed on the piezoelectric member 12 corresponding to the partition walls 6A of the pressurized liquid chambers 6 are joined. Such a configuration is referred to as a bi-pitch structure, but as shown in FIG. 3, a normal pitch structure in which all the piezoelectric columns are drive columns 12A may be used.

  These driving pillars 12A and non-driving pillars 12B serving as pillars are formed by subjecting the laminated piezoelectric member 12 to slit processing by half-cut dicing and dividing it into comb teeth. The non-driving pillar 12B is also a piezoelectric element. However, in order not to apply the driving voltage, it is a simple column. The laminated piezoelectric member 12 is bonded to the base member 13.

  The piezoelectric member 12 includes, for example, a lead zirconate titanate (PZT) piezoelectric layer having a thickness of 10 to 50 μm / layer, and an internal electrode layer made of silver / palladium (AgPd) having a thickness of several μm / layer. The internal electrodes are alternately electrically connected to the individual electrodes and the common electrode which are the end face electrodes (external electrodes) on the end face, and a drive signal is supplied to these electrodes via the FPC cable 16 Like to do.

  In addition, the ink in the pressurized liquid chamber 6 may be pressurized using the displacement in the d33 direction as the piezoelectric direction of the piezoelectric member 12, or the pressurized liquid chamber using the displacement in the d31 direction as the piezoelectric direction of the piezoelectric element 12. It is also possible to employ a configuration in which the ink in the six is pressurized. In the present embodiment, a configuration using displacement in the d33 direction is adopted.

  Further, a frame member 17 formed by injection molding with, for example, epoxy resin or polyphenylene sulfite (PPS) is joined to the periphery of the diaphragm member 2 with an adhesive.

  A common liquid chamber 8 for supplying ink to each pressurized liquid chamber 6 is formed in the frame member 17, and the supply port 9 formed in the diaphragm member 2 from the common liquid chamber 8 and upstream of the fluid resistance portion 7 are formed. Ink is supplied to the pressurized liquid chamber 6 through the formed flow path 10 and the fluid resistance portion 7. The frame member 17 is also formed with an ink supply port 19 for supplying ink to the common liquid chamber 8 from the outside.

  Damper means for absorbing and attenuating pressure fluctuations in the common liquid chamber 8 is provided. This damper means is formed by a thin portion 21 consisting only of the first layer 2 a of the deformable diaphragm member 2 that forms a part of the wall surface of the common liquid chamber 8. By doing so, the pressure fluctuation in the common liquid chamber 8 at the time of discharge can be suppressed, and even when multiple bits are discharged at high speed, it can be stably discharged. The other surface side of the thin portion 21 faces the damper chamber 20.

  In the case of the bi-pitch structure shown in FIG. 2, the thickness of the flow path plate 1 is 100 μm to 600 μm, the length in the longitudinal direction of the liquid chamber 6 is 400 μm to 1600 μm, and the length (width) in the short direction is 120 to 139 μm. The width of the flow path partition 6A is about 15 to 50 μm (when the liquid chamber pitch is 150 dpi) at the joint surface with the diaphragm member 2. In the case of the normal pitch structure shown in FIG. 2, the flow path plate 1 has a thickness of 100 μm to 600 μm, the liquid chamber 6 has a length in the longitudinal direction of 400 μm to 1200 μm, and a length in the short direction (width). Is 50 to 70 μm (when the liquid chamber pitch is 300 dpi).

  In the liquid ejection head configured as described above, for example, the drive column 12A contracts by lowering the voltage applied to the drive column 12A from the reference potential, and the diaphragm member 2 descends to expand the volume of the pressurized liquid chamber 6. As a result, the ink flows into the pressurized liquid chamber 6 and then the voltage applied to the driving column 12A is increased to extend the driving column 12A in the stacking direction, and the diaphragm member 2 is deformed in the nozzle 4 direction and applied. By contracting the volume of the pressurized fluid chamber 6, the ink in the pressurized fluid chamber 6 is pressurized, and ink droplets are ejected (jetted) from the nozzle 4.

  Then, the diaphragm member 2 is restored to the initial position by returning the voltage applied to the drive column 12A to the reference potential, and the pressurized liquid chamber 6 expands to generate a negative pressure. At this time, the common liquid chamber 8 The pressurized liquid chamber 6 is filled with ink. Therefore, after the vibration of the meniscus surface of the nozzle 4 is attenuated and stabilized, the operation proceeds to the next droplet discharge.

  Note that the driving method of the head is not limited to the above example (drawing-pushing), and striking or pushing can be performed depending on the direction of the drive waveform.

Next, the adhesive 51 for joining the flow path plate 1, the diaphragm member 2, and the nozzle plate 3 and the joining method will be described.
First, the components that make up ink, such as hydrophilic organic solvents and moisture. Penetration is promoted by penetrating into the adhesive 51 and the bonding interface, and the adhesive strength is lowered. Therefore, it is important to suppress ink permeation into the adhesive 51. In order to suppress the penetration of the ink, the density of the adhesive 51 is improved from the structure surface after curing, and the swelling of the adhesive 51 is suppressed, and the penetration is prevented as a composition that does not mix with the ink from the chemical side. Is required.

  Epoxy resin is a material often used as a metal adhesive. As an epoxy resin used as such a metal adhesive, there is an adhesive obtained by curing a monomer having a hydroxyl group, and the hydrogen bonding force acting between the hydroxyl group of the epoxy resin and the hydroxyl group attached to the oxide film on the metal surface. It has a very strong adhesive strength.

  However, an epoxy resin having a hydroxyl group breaks hydrogen bonds due to water that has permeated from ink in the head, and the adhesion at the bonding interface gradually decreases. However, since epoxy adhesives are bonded by three-dimensional cross-linking of a plurality of epoxy groups, they are relatively effective for water-based inks because they have a higher cross-linking density than other adhesives and are less likely to swell. It is. However, when an ink with a large amount of a hydrophilic organic solvent such as an ink for curling suppression or an ink for a non-absorbing film medium is used, a decrease in strength cannot be suppressed.

Therefore, in the present invention, first, the epoxy adhesive used as the adhesive 51 is:
(A) Epoxy resin monomer having no hydroxyl group (B) Curing agent (C) Prescription containing a silane coupling agent (10 wt% to 30 wt%) having a silanol group represented by formula (1) .

（ただし、式中、Ｒ１〜Ｒ３は、炭化水酸基（炭素数１〜３）、Ｒ４は、アミノ基,グリシジル基,エポキシ基,炭化水素鎖,エーテル鎖）

(In the formula, R1 to R3 are carbonized hydroxyl groups (1 to 3 carbon atoms), R4 is an amino group, glycidyl group, epoxy group, hydrocarbon chain, ether chain)

  As described above, the epoxy resin in which the epoxy resin monomer having no hydroxyl group is cured is relatively slowly deteriorated in performance due to moisture absorption. This is due to the following reason. Although the hydrogen bond working between the hydroxyl groups has a strong physical bonding force, it is chemically easily hydrolyzed by a reaction with water. An epoxy resin obtained by curing an epoxy resin monomer having no hydroxyl group does not have a hydroxyl group other than a hydroxyl group formed by ring opening of an epoxy group, so that the cured product becomes a resin having a relatively low hydroxyl group concentration. It is difficult to form hydrogen bonds. Therefore, it is difficult to change the binding force.

  On the other hand, the liquid ejection head is always exposed to an environment wet with ink or a filling liquid, and the adhesive is always placed in an environment of 100% humidity. Therefore, it is clear that it is more beneficial to use an adhesive made of an epoxy resin monomer as described above.

  In this case, the basic adhesion is insufficient when the monomer is composed only of a monomer having no hydroxyl group. Therefore, in the present invention, a silane coupling agent having a silanol group structure represented by Formula 1 is further contained in the adhesive at a ratio of 10 wt% to 30 wt%.

  Here, the silanol group of the silane coupling agent reacts with surrounding moisture to form a hydroxyl group and a primary alcohol. This hydroxyl group is dehydrated and condensed with a hydroxyl group at the bonding interface to form a chemical bond, thereby providing strong adhesion between the adhesive and the bonding member.

  In order to improve the adhesiveness by using this, a silane coupling agent is generally applied as a base treatment for the adhesive interface and mixed with an epoxy adhesive (integral blend method). In the integral blend method, about 0.5 to 2% by weight is usually used. The reason is that an increase in adhesion strength cannot be expected even if the filling ratio is increased.

  In contrast, in the epoxy adhesive of the present invention, a silane coupling agent is contained in the adhesive in an amount of 10% by weight to 30% by weight.

  In other words, the silane coupling agent can be concentrated on the adhesive surface by mixing a large amount of silane coupling agent of 10% by weight or more with the epoxy adhesive and volatilizing the diluted solvent of the adhesive in a reduced pressure atmosphere after application. It becomes like this.

  Then, the silane coupling agent concentrated and exposed to the adhesive interface is humidified in a high humidity atmosphere to dehydrate and condense with moisture in the air to form a siloxane bond. Siloxane bonds are very strong and dense, and have high chemical resistance. For this reason, swelling can be well suppressed in the vicinity of the interface, and strength reduction can be prevented.

  Humidification is preferably performed in the range of 70 to 90% for about 20 minutes, and it is known that when humidified for 40 minutes or more, it is deactivated and bonding strength decreases.

  On the other hand, when the silane coupling agent is contained in an amount of more than 30% by weight, the adhesive strength is lowered. The proportion of silane coupling agents in the adhesive that cannot form hydroxyl groups becomes too high, and since such silane coupling agents bind to the epoxy resin only at one end, the crosslinking density becomes too low, The swelling rate of the entire resin will be high. Therefore, the addition amount is preferably 30% or less.

  The silane coupling agent may have a structure having a dialkylsiloxy group, but the silane coupling agent having a trialkylsiloxy group has a lower rate of decrease in adhesion after adhesion.

  In addition, the silane coupling agent contained in the adhesive of the present invention is 10% to 30%, which is much higher than that of conventional adhesives. For this reason, methoxysilane is sufficiently humidified and decomposed in a short time without generating hydroxyl groups. If it is too long, the silane coupling agents are oligomerized and deactivated. Therefore, by managing according to just the right time and humidity, the adhesive exhibits the maximum wettability and can suppress manufacturing variations.

The following can be mentioned as a coupling agent.
Silane coupling agent 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane

  N-2 (-aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2 (-aminoethyl) -3-aminopropylmethyldiethoxysilane, N-2 (-aminoethyl) -3-aminopropyltrimethoxy Silane, N-2 (-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, (1,3-dimethyl-butylidene) -propylamine, N- Phenyl-3-aminopropyltrimethoxysilane, N, N-bis (3- (trimethoxysilyl) propyl) ethylenediamine, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propane An amine, 3-phenylaminopropyltrimethoxysilane,

  Aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, N- (2- (vinylbenzamino) ethyl) -3-aminopropyltrimethoxysilane hydrochloride, 1,2-ethanediamine, N- {3- (Trimethoxysilyl) propyl}-, N-{(ethenylphenyl) methyl} derivative / hydrochloride

  3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane

  Regarding the organic group of the silane coupling agent, those having a functional group that reacts with the epoxy resin are preferable, and the above-mentioned coupling agent is an example.

The following are mentioned as a hardening | curing agent contained in the epoxy adhesive of this invention.
Curing agents such as aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyaminoamides, secondary amines, acid anhydrides, carboxylic acids, phenols, mercaptans, isocyanates, etc., tertiary amines Anion polymerization catalysts such as imidazoles, cationic polymerization catalysts such as Lewis acids, dicyandiamide, organic acid dihydrazides, N, N-dimethylurea derivatives, amine adducts, melamines, amine imides, boron halide complexes, block carboxylic acids And modified products thereof, adducts thereof, microencapsulates thereof, and the like, but are not limited thereto. These thermal latent curing agents can be used alone or in admixture of two or more.

  Among these, dicyandiamide, N, N-dimethylurea derivative, imidazole solid at room temperature, solid dispersion type amine adduct type latent curing agent, reaction product of amine compound and epoxy compound (amine-epoxy) are preferable. Adduct system), reaction products of amine compounds with isocyanate compounds or urea compounds (urea type adduct systems), and dimethylurea.

  These latent curing accelerators can be purchased from Mitsubishi Chemical, Shikoku Kasei Kogyo, Ajinomoto Fine Techno, Adeka, Asahi Kasei Chemicals, Fuji Kasei Kogyo, etc.

  In particular, an adhesive bonded with an amine curing agent is unlikely to decrease in strength. The reason is considered as follows, but the present invention is not limited to this. That is, the amine-based curing agent opens an epoxy group at the time of bonding to form an amide bond, but the hydroxyl group formed by the amide bond is weaker in electrical attraction than the alcoholic hydroxyl group and hardly forms a hydrogen bond.

  About the epoxy resin which comprises an epoxy adhesive, the hardened | cured material which comprised the three-dimensional bridge | crosslinking is obtained by using the polyfunctional compound which has an epoxy group. Epoxy resins can be classified into glycidyl ether series, glycidyl ester series, glycidyl amine series, and the like depending on the glycidyl group binding site, and a wide variety of compounds are obtained depending on the compound serving as the binding matrix.

It is known that a resin obtained by polymerizing such a polyfunctional epoxy has a relatively low moisture absorption and a high Tg. For this reason, it is mainly used as a semiconductor protective agent or a circuit board protective agent.

  The more three-dimensional crosslinks, the more suppressed the swelling, but the resin becomes more rigid. In addition, since there are hydroxyl groups at the cross-linking points, the wettability deteriorates even if the cross-linking point density is too high.

  As a diluting solvent for diluting the adhesive, a solvent without active hydrogen is preferable from a solvent with active hydrogen reactive with an epoxy group from the viewpoint of storage stability of the adhesive, but wettability to components, drying speed, viscosity It is possible to select freely from the above aspects, and even if it is not completely dissolved but dispersed, it can be used without any problem if the adhesive layer is formed upon drying.

  In addition to the epoxy resin, curing agent, solvent, and coupling agent, the epoxy adhesive may contain a filler, other binder resin, a viscosity modifier, and the like. The filler may be inorganic particles such as silica or alumina, or may be resin fine particles of melamine resin or acrylic resin. It is also possible to add a higher fatty acid amide or the like as a viscosity modifier to adjust the viscosity to a suitable one by applying an adhesive. Moreover, since the coating spot by a bubble does not generate | occur | produce in a coating film, you may add a foam suppressor and an antifoamer.

  And (A) an epoxy resin monomer having no hydroxyl group, (B) a curing agent, and (C) an epoxy containing a silane coupling agent (10 wt% to 30 wt%) having a silanol group represented by Formula 1 above. Applying adhesive to one of the members to be joined in a diluted state with a diluting solvent (for example, one or both of the flow path plate 1, the vibration plate member 2, and the nozzle plate 3), and diluting under reduced pressure Two members to be joined (channel plate 1 and vibration plate member 2, channel plate 1 and nozzle plate 3) are joined via an epoxy adhesive in a process of evaporating the solvent and in a humidified state. By adopting a structure to perform the process, it is resistant to the liquid used, and can suppress the divergence due to penetration into the bonding interface as much as possible to maintain sufficient bonding strength and improve bonding reliability. The life of the head is prolonged.

  And the liquid discharge head manufactured in this way can perform the stable droplet discharge over a long period of time.

Next, specific examples will be described.
<Epoxy adhesive evaluation method>
(1) Initial adhesion: The peel strength test was performed.
Peeling test: Epoxy adhesives of Preparation Examples 1 to 12 shown in Tables 1 and 2 on a bonded SUS304 plate formed on a rolled SUS304 plate having a width of 140 μm and a length of 2000 μm at a pitch of 150 dpi and a width of 19 mm and a thickness of 40 μm. Is dried to a thickness of 1.0 μm or less, the solvent is dried under reduced pressure, left in a sealed space maintained at 85% RH for 20 minutes, and then heated and pressurized to bond the sample to the desktop type. The average peel strength when peeled 5 mm at a rate of 1 mm / min at 90 ° peel strength was measured with a material testing machine (Tensilon STA-1150, manufactured by Orientec Co., Ltd.). The evaluation results were ◯: 2N or more, Δ: less than 1.5 to 2N, and x: 1.5N or less. The results are shown in Tables 1 and 2.

(2) Adhesion reliability: Peel strength test, tensile strength test After cured adhesion, the sample was subjected to an ink resistance test (ink immersion; evaluation ink A, 60 ° C., 2 weeks), and then subjected to a peel test and a tensile strength test. . Then, the peel strength reduction rate was determined by comparison with the initial peel strength. The evaluation result is
Initial adhesiveness: ○: 2N or more, Δ: 1.5 to less than 2N, x: 1.5N or less,
Adhesion reliability: ○: Reduction rate of 5% or less, Δ: Reduction rate of 5% to less than 10%, x: Reduction rate of 10% to 1.5N. The results are shown in Tables 1 and 2.

In addition, the specific example of each composition in Table 1 and Table 2 is as follows.
OH group-less (not containing hydroxyl group) epoxy resin, DIC HP-4032D (trade name),
Normal epoxy resin: jER1010 (trade name) manufactured by Mitsubishi Chemical,
Curing agent A: jER Cure DICY15 (trade name) manufactured by Mitsubishi Chemical,
Curing agent B: Cure Sole 2PZ (trade name) manufactured by Shikoku Kasei Kogyo,
Filler: EVONIK AEROSIL RY200 (trade name),
Solvent A: methyl ethyl ketone,
Solvent B: Methyl ethyl ketone (for diluting hardener)
Solvent C: N-methyl-2-pyrrolidone (for dissolving DICY)
Curing accelerator: Cure Sole 2MZ (trade name) manufactured by Shikoku Chemicals,
Coupling agent: Shin-Etsu Chemical KBM-403

<Inkjet head discharge evaluation>
For the inkjet head, the head according to the above embodiment was bonded to the flow path plate and the nozzle plate as Examples 1 to 12 using the epoxy adhesives of Adjustment Examples 1 to 12 shown in Tables 1 and 2. It was set as the inkjet head for evaluation. The produced inkjet head was evaluated according to the combination of ink and adhesive as shown in Table 2. The evaluation of the inkjet head is as follows. The results are shown in Tables 3 and 4.

(A) Ink filling property: Piped so that ink can be supplied to the ink-jet head. After suctioning from the nozzle surface at 50 kPa for 1 minute, the head surface is maintained, and an appropriate negative pressure is formed and discharged. The discharge rate (number of discharge nozzles / total number of nozzles × 100) was evaluated. In the evaluation results, a discharge rate of 98% or more was indicated by ◯, a discharge rate of 90% or more by Δ, and a discharge rate of less than 90% by ×.

(B) Ink resistance reliability: The ink-jet head filled with the ink was allowed to stand at 60 ° C. for 3 months, and the state of the ejection speed after being left was evaluated. In the evaluation results, a case where the discharge speeds of all the nozzles satisfy less than ± 10% with respect to the average before being left is evaluated as ◯, and a case where the discharge speed is higher than that is indicated as ×.

  Note that an ink cartridge in which a tank for supplying ink to the liquid discharge head of each of the above embodiments is integrated can be configured.

Next, an example of the image forming apparatus according to the present invention including the liquid discharge head according to the present invention will be described with reference to FIGS. FIG. 4 is a schematic configuration diagram for explaining the overall configuration of the mechanism portion of the apparatus, and FIG. 5 is a plan view of a principal portion of the mechanism portion.
This image forming apparatus is a serial type image forming apparatus, and a carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. The main scanning motor that does not perform moving scanning in the direction indicated by the arrow (carriage main scanning direction) via the timing belt.

  The carriage 233 is supplied with ink supplied to the same head as the liquid discharge head according to the present invention for discharging ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). A recording head 234 composed of a liquid ejection head unit with an integrated tank is arranged in a sub-scanning direction perpendicular to the main scanning direction with a nozzle row composed of a plurality of nozzles, and mounted with the ink droplet ejection direction facing downward. Yes.

  The recording head 234 is configured by attaching liquid discharge head units 234a and 234b each having two nozzle rows to one base member, and one nozzle row of one head 234a receives black (K) droplets. The other nozzle row ejects cyan (C) droplets, the other nozzle row of the other head 234b ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets. To do. Here, a configuration in which droplets of four colors are ejected in a two-head configuration is used, but it is also possible to arrange four nozzle rows per head and eject each of the four colors with one head.

  Further, the ink of each color is replenished and supplied from the ink cartridge 210 of each color to the tank 235 of the recording head 234 via the supply tube 236 of each color.

  On the other hand, as a paper feeding unit for feeding the paper 242 stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon roller (feeding) that separates and feeds the paper 242 one by one from the paper stacking unit 241. A separation pad 244 made of a material having a large coefficient of friction is provided opposite to the sheet roller 243 and the sheet feeding roller 243, and the separation pad 244 is urged toward the sheet feeding roller 243 side.

  In order to feed the sheet 242 fed from the sheet feeding unit to the lower side of the recording head 234, a guide member 245 for guiding the sheet 242, a counter roller 246, a conveyance guide member 247, and a tip pressure roller. And a conveying belt 251 which is a conveying means for electrostatically attracting the fed paper 242 and conveying it at a position facing the recording head 234.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction). In addition, a charging roller 256 that is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 256 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251. The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 242 recorded by the recording head 234, a separation claw 261 for separating the paper 242 from the transport belt 251, a paper discharge roller 262, and a paper discharge roller 263 are provided. A paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body. The duplex unit 271 takes in the paper 242 returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, a maintenance / recovery mechanism 281 that is a head maintenance / recovery device according to the present invention includes a recovery means for maintaining and recovering the nozzle state of the recording head 234 in the non-printing area on one side of the carriage 233 in the scanning direction. Is arranged. The maintenance / recovery mechanism 281 includes cap members (hereinafter referred to as “caps”) 282a and 282b (hereinafter referred to as “caps 282” when not distinguished) for capping each nozzle surface of the recording head 234, and nozzle surfaces. A wiper blade 283 that is a blade member for wiping the ink, and an empty discharge receiver 284 that receives liquid droplets for discharging the liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing.

  Further, in the non-printing area on the other side in the scanning direction of the carriage 233, there is an empty space for receiving a liquid droplet when performing an empty discharge for discharging a liquid droplet that does not contribute to the recording in order to discharge the recording liquid thickened during the recording. A discharge receiver 288 is disposed, and the idle discharge receiver 288 is provided with an opening 289 along the nozzle row direction of the recording head 234 and the like.

  In this image forming apparatus configured as described above, the sheets 242 are separated and fed one by one from the sheet feeding tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and is conveyed to the conveyor belt 251 and the counter. It is sandwiched between the rollers 246 and conveyed, and further, the leading end is guided by the conveying guide 237 and pressed against the conveying belt 251 by the leading end pressing roller 249, and the conveying direction is changed by approximately 90 °.

  At this time, a positive output and a negative output are alternately applied to the charging roller 256, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 251 alternates, that is, in the sub-scanning direction that is the circumferential direction. , Plus and minus are alternately charged in a band shape with a predetermined width. When the sheet 242 is fed onto the conveyance belt 251 charged alternately with plus and minus, the sheet 242 is attracted to the conveyance belt 251, and the sheet 242 is conveyed in the sub scanning direction by the circumferential movement of the conveyance belt 251.

  Therefore, by driving the recording head 234 according to the image signal while moving the carriage 233, ink droplets are ejected onto the stopped paper 242 to record one line, and after the paper 242 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 242 has reached the recording area, the recording operation is finished and the paper 242 is discharged onto the paper discharge tray 203.

  As described above, since the image forming apparatus includes the liquid discharge head according to the present invention as a recording head, a high-quality image can be formed.

  In the above embodiment, the present invention has been described with reference to an example in which the present invention is applied to a serial type image forming apparatus. However, the present invention can also be applied to a line type image forming apparatus. Further, as described above, the present invention can also be applied to an image forming apparatus that uses a liquid other than the narrowly defined ink or a fixing processing liquid.

DESCRIPTION OF SYMBOLS 1 Flow path plate 2 Vibrating plate member 3 Nozzle plate 4 Nozzle 5 Nozzle communication path 6 Pressurized liquid chamber 7 Fluid resistance part 8 Introduction part 10 Common liquid chamber 12 Piezoelectric member 12A Drive column 12B Non-drive column 51 Adhesive 233 Carriage 234a, 234b Recording head

Claims (5)

At least two members: a nozzle plate on which nozzles for discharging liquid droplets are formed; a flow path plate that forms a liquid chamber that communicates with the nozzles; and a vibration plate member that forms a part of the wall surface of the liquid chamber. In the manufacturing method of the liquid discharge head bonded with an adhesive,
The adhesive is
(A) Epoxy resin monomer having no hydroxyl group (B) Curing agent (C) Silane coupling agent having a silanol group represented by formula (1) (10 to 30% by weight)

(In the formula, R1 to R3 are carbonized hydroxyl groups (1 to 3 carbon atoms), R4 is an amino group, glycidyl group, epoxy group, hydrocarbon chain, ether chain)
An epoxy adhesive containing
Applying the epoxy adhesive to one of the members to be joined in a diluted state with a diluent solvent;
Evaporating the diluent solvent under reduced pressure;
And a step of joining two members to be joined through the epoxy adhesive in a humidified state in a high-humidity atmosphere.   The method for manufacturing a liquid discharge head according to claim 1, wherein at least one member of the two members joined by the epoxy adhesive is formed of SUS.   3. The method of manufacturing a liquid discharge head according to claim 1, wherein a silane coupling process is performed on at least one member of the two members joined by the epoxy adhesive. 4.   A liquid discharge head manufactured by the method for manufacturing a liquid discharge head according to claim 1.   An image forming apparatus comprising the liquid discharge head according to claim 4.

Images