JP2013001054A - Vibrating plate for liquid droplet ejection head, method for manufacturing vibrating plate for liquid droplet ejection head, liquid droplet ejection head, and liquid droplet ejection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a vibrating plate for a liquid droplet ejection head excellent in vibration characteristics; a method for manufacturing the vibrating plate for the liquid droplet ejection head for efficiently manufacturing the vibrating plate for the liquid droplet ejection head; the liquid droplet ejection head excellent in ink ejection characteristics; and a liquid droplet ejection apparatus having high reliability.SOLUTION: An inkjet recording head 1 has a substrate 20, a nozzle plate 10, a vibrating plate 35 constituted of a vibrating film 30 and a support portion 40, and a piezoelectric element 50. The support portion 40 is composed of light curing resin. The support portion 40 is desirably obtained by applying the light curing resin, which is not cured, to one surface of the vibrating film 30 to obtain an applied film, and then exposing a portion of the applied film to cure it.

Description

  The present invention relates to a droplet discharge head diaphragm, a method for manufacturing a droplet discharge head diaphragm, a droplet discharge head, and a droplet discharge apparatus.

For example, a droplet discharge device such as an ink jet printer is provided with a droplet discharge head for discharging droplets. As such a droplet discharge head, for example, an ink chamber (cavity) that communicates with a nozzle that discharges ink as droplets and stores ink, and a piezoelectric element for driving that deforms the wall surface of the ink chamber, What is provided with is known.
In such a droplet discharge head, a part of the ink chamber (vibrating plate) is displaced by expanding and contracting the driving piezoelectric element. Thereby, the volume of the ink chamber is changed and ink droplets are ejected from the nozzles.

By the way, this droplet discharge head has a nozzle plate on which nozzles are formed, a substrate on which ink chambers are formed, a vibration plate that changes the volume of the ink chambers, and a piezoelectric element that vibrates the vibration plate due to strain. They are assembled by joining them together.
Further, the diaphragm has a vibration film that vibrates due to distortion of the piezoelectric element and a support plate that propagates the distortion of the piezoelectric element to the vibration film, and is assembled by joining them together (for example, , See Patent Document 1).
Patent Document 1 discloses a diaphragm formed by bonding a polymer film and a metal thin plate with an adhesive. Among these, an island part is formed in a metal thin plate by performing an etching process after adhesion | attachment. A piezoelectric vibrator is fixed to the island portion so as to receive displacement of the piezoelectric vibrator.

Here, since the droplet discharge head needs to accurately discharge ink in all environments, the distortion of the piezoelectric vibrator (piezoelectric element) is maintained in the ink chamber while maintaining a certain relationship regardless of the environment. It is necessary to convert to volume change. For this reason, the diaphragm which bears a part of the inner wall of the ink chamber must be capable of stable vibration.
However, the resin material constituting the polymer film and the metal material constituting the metal thin plate are greatly different from each other in the coefficient of linear expansion, so that stress is easily generated at the adhesion interface. For this reason, the generated stress has an adverse effect on the vibration characteristics of the diaphragm.

JP-A-8-187868

  SUMMARY OF THE INVENTION An object of the present invention is to provide a droplet ejection head diaphragm excellent in vibration characteristics, a method for manufacturing a droplet ejection head diaphragm capable of efficiently producing such a droplet ejection head diaphragm, and excellent ink ejection characteristics. Another object of the present invention is to provide a highly reliable droplet discharge device and a droplet discharge device.

The above object is achieved by the present invention described below.
The droplet ejection head diaphragm of the present invention is a droplet ejection head diaphragm that is displaced according to the vibration of the vibration means and changes the volume of the ejection liquid storage chamber for storing the ejection liquid,
A vibration film made of a resin material;
Provided on a part of one surface of the vibration film, and having a support portion for transmitting the vibration of the vibration means to the vibration film,
The support portion is made of a photocurable resin.
Thereby, a diaphragm for a droplet discharge head having excellent vibration characteristics can be obtained.

In the vibration plate for a droplet discharge head according to the present invention, the support portion applies an uncured photocurable resin on one surface of the vibration film to obtain a coating film, and then a part of the coating film. Is preferably obtained by exposing and curing.
As a result, a more flexible liquid ejection head diaphragm can be obtained. Further, since there is no concern about the adhesive sticking out from the outer edge of the support portion, a droplet discharge head diaphragm capable of reliably reproducing the designed vibration characteristics can be obtained.

In the diaphragm for a droplet discharge head of the present invention, it is preferable that the photocurable resin is composed mainly of a polyimide resin.
Thereby, a diaphragm for a droplet discharge head provided with a support portion capable of satisfactorily transmitting vibration can be obtained.
In the diaphragm for a droplet discharge head according to the present invention, it is preferable that the support portion has a concave portion whose surface is recessed in a region other than the edge portion in a plan view.
As a result, the concave portion has a shape that can reliably store the adhesive, and therefore, even when there is too much adhesive to bond between the support portion and the piezoelectric element, the excess portion protrudes outside the support portion. Instead, it can be filled by being pushed into the recess, and the vibration characteristics of the diaphragm can be prevented from deviating from the design value.

In the diaphragm for a droplet discharge head of the present invention, it is preferable that the concave portion has a perfect circle, an ellipse, or an ellipse in a plan view.
As a result, the stress concentration can be easily relaxed at the interface between the adhesive and the support portion, and it is possible to reliably prevent the occurrence of problems such as the peeling of the adhesive and the decrease in the adhesive force due to the stress concentration.
In the diaphragm for a droplet discharge head according to the present invention, the resin material constituting the vibration film is preferably polyphenylene sulfide.
As a result, it is possible to obtain a vibration plate for a droplet discharge head that is excellent in chemical resistance and hardly deteriorates or deteriorates even when exposed to ink for a long period of time.

The method for manufacturing a diaphragm for a droplet discharge head according to the present invention is a method for manufacturing a diaphragm for a droplet discharge head that is displaced according to the vibration of a vibrating means and changes the volume of a discharge liquid storage chamber that stores the discharge liquid. Because
On one surface of the vibration film made of a resin material, a step of applying an uncured photocurable resin to obtain a coating film;
Exposing and curing a part of the coating film, and obtaining a support portion that transmits vibrations of the vibration means to the vibration film;
And a step of removing the portion of the coating film that has not been cured by the exposure.
Thereby, a diaphragm for a droplet discharge head having excellent vibration characteristics can be efficiently manufactured.
In the method for manufacturing a diaphragm for a droplet discharge head according to the present invention, the step of exposing a part of the coating film is preferably performed by placing a mask on the coating film and exposing.
Thereby, since the exposure region can be easily selected by the mask, the planar view shape of the support portion can be adjusted easily and with high accuracy.

The droplet discharge head of the present invention includes a substrate on which a discharge liquid storage chamber for storing discharge liquid is formed,
A nozzle plate that is provided on one surface of the substrate so as to cover the discharge liquid storage chamber and includes nozzle holes for discharging the discharge liquid as droplets;
A diaphragm provided on the other surface of the substrate so as to cover the discharge liquid storage chamber;
A liquid droplet ejection head having vibration means provided on the opposite side of the vibration plate from the substrate,
The vibration plate includes a vibration film, and a support portion provided on a part of one surface of the vibration film so as to contact the vibration means between the vibration film and the vibration means. Yes,
The support portion is made of a photocurable resin.
Thereby, a droplet discharge head having excellent ink discharge characteristics can be obtained.
The liquid droplet ejection apparatus of the present invention has the liquid droplet ejection head of the present invention.
Thereby, a highly reliable droplet discharge device can be obtained.

1 is a longitudinal sectional view showing an embodiment in which a droplet discharge head of the present invention is applied to an ink jet recording head. It is the schematic which shows embodiment of an inkjet printer provided with the inkjet recording head shown in FIG. It is a figure (longitudinal sectional drawing) for demonstrating the manufacturing method of an inkjet recording head. It is a figure (longitudinal sectional drawing) for demonstrating the manufacturing method of an inkjet recording head. It is a figure (longitudinal sectional drawing) for demonstrating the manufacturing method of an inkjet recording head. It is a figure (longitudinal sectional drawing) for demonstrating the manufacturing method of an inkjet recording head. It is a perspective view which shows the diaphragm with which 2nd Embodiment of the droplet discharge head of this invention is provided.

Hereinafter, a diaphragm for a droplet discharge head according to the present invention, a method for manufacturing a diaphragm for a droplet discharge head capable of efficiently manufacturing such a diaphragm for a droplet discharge head, a droplet discharge head having excellent ink discharge characteristics, A highly reliable droplet discharge device will be described in detail based on a preferred embodiment shown in the accompanying drawings.
<Inkjet recording head>
(First embodiment)
First, a first embodiment of the droplet discharge head of the present invention will be described. Hereinafter, a case where the droplet discharge head of the present invention is applied to an ink jet recording head will be described as an example.

FIG. 1 is a longitudinal sectional view showing an embodiment in which the droplet discharge head of the present invention is applied to an ink jet recording head. FIG. 2 is a schematic view showing an embodiment of an ink jet printer including the ink jet recording head shown in FIG. It is. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.
An ink jet recording head 1 shown in FIG. 1 (hereinafter sometimes simply referred to as “head 1”) is mounted on an ink jet printer (droplet discharge device of the present invention) 9 as shown in FIG.

The ink jet printer 9 shown in FIG. 2 includes an apparatus main body 92, a tray 921 in which the recording paper P is placed at the upper rear, a paper discharge port 922 for discharging the recording paper P in the lower front, and an operation panel on the upper surface. 97.
The operation panel 97 is composed of, for example, a liquid crystal display, an organic EL display, an LED lamp, and the like. And.

Further, inside the apparatus main body 92, mainly a printing apparatus (printing means) 94 provided with a reciprocating head unit 93 and a paper feeding apparatus (paper feeding means) for feeding recording paper P to the printing apparatus 94 one by one. 95 and a control unit (control means) 96 for controlling the printing device 94 and the paper feeding device 95.
Under the control of the control unit 96, the paper feeding device 95 intermittently feeds the recording paper P one by one. The recording paper P passes near the lower part of the head unit 93. At this time, the head unit 93 reciprocates in a direction substantially orthogonal to the feeding direction of the recording paper P, and printing on the recording paper P is performed. That is, the reciprocating motion of the head unit 93 and the intermittent feeding of the recording paper P are the main scanning and sub-scanning in printing, and ink jet printing is performed.

The printing apparatus 94 includes a head unit 93, a carriage motor 941 that is a drive source of the head unit 93, and a reciprocating mechanism 942 that reciprocates the head unit 93 in response to the rotation of the carriage motor 941.
The head unit 93 includes a head 1 having a large number of nozzle holes 11, an ink cartridge 931 that supplies ink to the head 1, and a carriage 932 on which the head 1 and the ink cartridge 931 are mounted at the lower part thereof.

Ink cartridge 931 is filled with four color inks of yellow, cyan, magenta, and black (black), thereby enabling full color printing.
The reciprocating mechanism 942 includes a carriage guide shaft 943 whose both ends are supported by a frame (not shown), and a timing belt 944 extending in parallel with the carriage guide shaft 943.

The carriage 932 is supported by the carriage guide shaft 943 so as to be able to reciprocate and is fixed to a part of the timing belt 944.
When the timing belt 944 travels forward and backward through the pulley by the operation of the carriage motor 941, the head unit 93 reciprocates as guided by the carriage guide shaft 943. During this reciprocation, ink is appropriately discharged from the head 1 and printing on the recording paper P is performed.

The sheet feeding device 95 includes a sheet feeding motor 951 serving as a driving source thereof, and a sheet feeding roller 952 that is rotated by the operation of the sheet feeding motor 951.
The paper feed roller 952 includes a driven roller 952a and a drive roller 952b that are vertically opposed to each other with a feeding path (recording paper P) of the recording paper P interposed therebetween. The drive roller 952b is connected to the paper feed motor 951. As a result, the paper feed roller 952 can feed a large number of recording sheets P set on the tray 921 one by one toward the printing apparatus 94. Instead of the tray 921, a configuration in which a paper feed cassette that stores the recording paper P can be detachably mounted may be employed.

The control unit 96 performs printing by controlling the printing device 94, the paper feeding device 95, and the like based on print data input from a host computer such as a personal computer or a digital camera.
Although not shown, the control unit 96 mainly includes a memory that stores a control program for controlling each unit, a drive circuit that drives the printing device 94 (carriage motor 941), and a paper feeding device 95 (paper feeding motor 951). Drive circuit, a communication circuit for obtaining print data from a host computer, and a CPU that is electrically connected to these and performs various controls in each unit.

In addition, for example, various sensors that can detect the remaining amount of ink in the ink cartridge 931, the position of the head unit 93, and the like are electrically connected to the CPU.
The control unit 96 obtains the print data via the communication circuit and stores it in the memory. The CPU processes the print data and outputs a drive signal to each drive circuit based on the process data and input data from various sensors. The printing device 94 and the paper feeding device 95 are operated by this drive signal. As a result, printing is performed on the recording paper P.

Hereinafter, the head 1 will be described in detail with reference to FIG.
As shown in FIG. 1, the head 1 includes a nozzle plate 10, a discharge liquid storage chamber forming substrate (substrate) 20 provided on the nozzle plate 10, and a vibration film provided on the discharge liquid storage chamber forming substrate 20. 30, a support portion 40 provided on the vibration film 30, and a piezoelectric element (vibration means) 50 and a case head 60 provided on the support portion 40. In the present embodiment, the head 1 constitutes a piezo jet head.

A plurality of discharge liquid storage chambers (pressure chambers) 21 for storing ink are formed on the discharge liquid storage chamber forming substrate 20 (hereinafter referred to as “substrate 20” for short). A common discharge liquid supply chamber 22 that supplies ink to each discharge liquid storage chamber 21 is formed.
As shown in FIG. 1, each of the discharge liquid storage chambers 21 and the discharge liquid supply chambers 22 has a substantially rectangular shape in plan view, and the width (short side) of each of the discharge liquid storage chambers 21 is the discharge liquid supply chamber. It is narrower than the width (short side) of 22.
Further, each discharge liquid storage chamber 21 is arranged so as to be substantially perpendicular to the discharge liquid supply chamber 22, and each discharge liquid storage chamber 21 and the discharge liquid supply chamber 22 are comb-like in plan view. It has a shape.

  The material constituting the substrate 20 is not particularly limited. For example, silicon materials such as single crystal silicon, polycrystalline silicon, and amorphous silicon, metal materials such as stainless steel, glass materials such as quartz glass, alumina Ceramic materials such as graphite, carbon materials such as graphite, polyolefins, polyvinyl chloride, acrylonitrile-styrene copolymers (AS resins), resin materials such as silicone resins, etc., one or more of these Can be used in combination.

Moreover, the material which gave each process, such as an oxidation process (oxide film formation), a plating process, a passivation process, a nitriding process, to the above materials may be used.
Among these, the constituent material of the substrate 20 is preferably a silicon material or stainless steel. Since such a material is excellent in chemical resistance, even if it is exposed to ink for a long time, the substrate 20 can be reliably prevented from being deteriorated or deteriorated. Moreover, since these materials are excellent in workability, the substrate 20 with high dimensional accuracy can be obtained. For this reason, the accuracy of the volume of the discharge liquid storage chamber 21 and the discharge liquid supply chamber 22 is increased, and the head 1 capable of high-quality printing is obtained.

Further, the discharge liquid supply chamber 22 communicates with a discharge liquid supply path 61 provided in a case head 60 described later, and is a part of a reservoir 70 that functions as a common ink chamber that supplies ink to the plurality of discharge liquid storage chambers 21. Parts.
The nozzle plate 10 is bonded to the lower surface of the substrate 20 (the surface opposite to the vibration film 30) through the adhesive layer 15 so as to cover the discharge liquid storage chamber 21 and the discharge liquid supply chamber 22.

Nozzle holes 11 are formed (perforated) in the nozzle plate 10 so as to correspond to the respective discharge liquid storage chambers 21. By extruding the ink (discharge liquid) stored in the discharge liquid storage chamber 21 from the nozzle hole 11, the ink is discharged as droplets.
Further, the nozzle plate 10 constitutes the lower surface of the inner wall surface of each discharge liquid storage chamber 21 and the discharge liquid supply chamber 22. That is, each of the discharge liquid storage chambers 21 and the discharge liquid supply chamber 22 is defined by the nozzle plate 10, the substrate 20, and the vibration film 30.

Examples of the material constituting the nozzle plate 10 include silicon materials, metal materials, glass materials, ceramic materials, carbon materials, resin materials, or one or more of these materials as described above. The composite material etc. which were combined are mentioned.
Among these, it is preferable that the constituent material of the nozzle plate 10 is a silicon material or stainless steel. Since such a material is excellent in chemical resistance, it is possible to reliably prevent the nozzle plate 10 from being altered or deteriorated even when exposed to ink for a long time. Moreover, since these materials are excellent in workability, the nozzle plate 10 with high dimensional accuracy can be obtained. For this reason, the highly reliable head 1 is obtained.

The constituent material of the nozzle plate 10 is preferably a material having a linear expansion coefficient of about 2.5 × 10 ⁻⁶ / ° C. to 4.5 × 10 ⁻⁶ / ° C. at 300 ° C. or lower.
The thickness of the nozzle plate 10 is not particularly limited, but is preferably about 0.01 mm or more and 1 mm or less.
Moreover, it is preferable to perform a liquid repellent treatment on the lower surface of the nozzle plate 10 as necessary. Thereby, it is possible to prevent ink droplets ejected from the nozzle holes from being ejected in unintended directions.

A vibration film 30 is bonded to the upper surface (the other surface) of the substrate 20 through the adhesive layer 25 so as to cover the discharge liquid storage chamber 21 and the discharge liquid supply chamber 22.
The vibration film 30 constitutes the upper surface of the inner wall surface of each discharge liquid storage chamber 21 and the discharge liquid supply chamber 22. That is, each of the discharge liquid storage chambers 21 and the discharge liquid supply chamber 22 is defined by the vibration film 30, the substrate 20, and the nozzle plate 10. In addition, since the vibration film 30 is securely bonded to the substrate 20, the liquid tightness of each discharge liquid storage chamber 21 and the discharge liquid supply chamber 22 is ensured.

Furthermore, the vibration film 30 has a function of elastic deformation. Therefore, the volume of the discharge liquid storage chamber 21 can be changed by displacing (vibrating) the vibration film 30 via the support portion 40 due to the distortion generated in the piezoelectric element 50, and as a result, ink is discharged. The
Examples of the material constituting the vibration film 30 include a silicon material, a metal material, a glass material, a ceramic material, a carbon material, a resin material, or a combination of one or more of these materials as described above. Materials and the like.

  Among these, the constituent material of the vibration film 30 is preferably a resin material such as polyphenylene sulfide (PPS) or an aramid resin, a silicon material, or stainless steel, and more preferably polyphenylene sulfide. Since such a material is excellent in chemical resistance, even if it is exposed to ink for a long time, the vibration film 30 can be reliably prevented from being altered or deteriorated. For this reason, ink can be stored in the discharge liquid storage chamber 21 and the discharge liquid supply chamber 22 for a long period of time. Furthermore, since these are materials that can be elastically deformed at high speed, the volume of the discharge liquid storage chamber 21 can be changed at high speed, and as a result, ink can be discharged with high accuracy.

A support portion 40 is formed on the upper surface of the vibration film 30 so as to correspond to a part of the vibration film 30.
The support portion 40 has a function of propagating the distortion generated in the piezoelectric element 50 to the vibration film 30 through this. Accordingly, by generating distortion in the piezoelectric element 50, the vibration film 30 is displaced, and as a result, a volume change in each discharge liquid storage chamber 21 can be surely generated.

  In this invention, this support part 40 is comprised with the photocurable resin. The photocurable resin is a material that can be easily patterned by selecting an exposure region. For this reason, the support part 40 with high dimensional accuracy is obtained by using a photocurable resin. Accordingly, the vibration plate (vibration plate for a droplet discharge head of the present invention) 35 having the support portion 40 made of a photocurable resin has vibration characteristics as designed and can discharge ink with high accuracy. This contributes to the realization of the head 1.

Further, the photocurable resin constructs a network-like three-dimensional structure by a photocuring reaction or a photocrosslinking reaction. Since the photocurable resin has a high mechanical property isotropic property among the resin materials, the function of the support portion 40 for transmitting vibration can be more reliably achieved by using the photocurable resin. The support part 40 which can be obtained is obtained.
Further, by using a resin material as the constituent material of the support part 40, it is possible to suppress a difference in linear expansion coefficient between the support part 40 and the vibration film 30. As a result, it is possible to suppress the magnitude of stress generated based on the difference in linear expansion coefficient at the interface between the support portion 40 and the vibration film 30 at the time of manufacture and use, and to suppress deterioration of vibration characteristics due to the generation of stress. it can.

  The support portion 40 may be formed by sticking a piece made of a cured product of a photocurable resin to the upper surface of the vibration film 30, but preferably an uncured photocurable resin. Is applied to the upper surface (one surface) of the vibration film 30 to obtain a coating film, and then a part of the coating film is exposed and cured. The support portion 40 formed in this manner is bonded (attached) to the upper surface of the vibration film 30 without using an adhesive. For this reason, the diaphragm 35 becomes more flexible because the adhesive is only partially attached. Further, since there is no concern about the adhesive sticking out from the outer edge of the support portion 40, the diaphragm 35 can reliably reproduce the vibration characteristics as designed.

Examples of the photocurable resin include (meth) acrylic resins, melamine resins, epoxy resins, oxetane resins, phenol resins, urethane resins, polyimide resins, polyamide resins, and the like. What mixed 1 type or 2 types or more of them is used.
Among these, as the photocurable (meth) acrylic resin, for example, a monofunctional (meth) acrylate compound having one (meth) acryloyl group in the molecule, two or three (meth) methacrylates in the molecule. ) Polyfunctional (meth) acrylate compounds having acryloyl groups, styrene compounds, acrylic acid derivatives, acrylate compounds having 4 to 8 (meth) acryloyl groups in the molecule, epoxy (meth) acrylate compounds, urethane bonds (Meth) acrylate compounds having

  Examples of monofunctional (meth) acrylate compounds having one (meth) acryloyl group in the molecule include methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, phenyl (meth) acrylate, and benzyl (meth). Examples include acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, (meth) acryloylmorpholine, lauryl (meth) acrylate, and the like.

Moreover, as a photocurable melamine-type resin, the polymerization reaction material of a melamine and formaldehyde is mentioned, for example.
Moreover, as a photocurable epoxy resin, the compound which has at least 1 epoxy group is mentioned, for example. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol type epoxy resin such as bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. Examples thereof include novolak-type epoxy resins, aromatic epoxy resins such as trisphenolmethane triglycidyl ether, and hydrogenated products and brominated products thereof.

  Moreover, as a photocurable oxetane-type resin, the compound which has at least 1 oxetane ring is mentioned, for example. Specifically, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl {[-3 -(Triethoxylyl) propoxy] methyl} oxetane, 3-ethyl-3-methacryloxymethyloxetane, di [1-ethyl (3-oxetanyl)] methyl ether, 1,4-bis {[(3-ethyl-3 -Oxetanyl) methoxy] methyl} benzene, 4,4′-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, and the like.

Examples of the photo-curable phenolic resin include novolaks obtained by reacting phenols such as phenol and cresol with formaldehyde and the like.
Moreover, as a photocurable urethane type resin, the polymerization reaction material etc. which react diols, such as glycol, and diisocyanate are mentioned, for example.
Of the above-mentioned photocurable resins, polyimide resins are particularly preferably used. The polyimide resin is particularly useful as a constituent material of the support portion 40 that is responsible for vibration transmission because of its excellent weather resistance and high mechanical strength.

As a photocurable polyimide resin, the compound which introduce | transduced the photosensitive group into the polyimide precursor is mentioned, for example. As the polyimide precursor, a known one is used, and examples thereof include polyamic acid obtained by reacting a diamine compound and tetracarboxylic dianhydride, or a polymer obtained by partially imidizing this polyamic acid. .
Among these, examples of the diamine compound include 1,4-phenylenediamine, 1,2-phenylenediamine, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 1,3-dimethyl-2,4-diamino. Benzene, 2,3-dimethyl-1,4-diaminonaphthalene, 2,6-dimethyl-1,5-diaminonaphthalene, 3,3 ′, 5,5′-tetramethyl-4,4′-diaminodiphenylmethane and 3 , 3 ', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, C6-C20 aromatic diamine, 1,2-ethylenediamine, 1,6-hexanediamine, 4,4'-diamino -3,3'-dimethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexyl, diaminocyclohexane, isophoronediamine Aliphatic diamines having a carbon number of 2 to 14 and the like as.

On the other hand, examples of the tetracarboxylic dianhydride include aromatic carboxylic dianhydrides and aliphatic carboxylic dianhydrides.
Among these, examples of the aromatic carboxylic dianhydride include pyromellitic dianhydride, 1.4,5,8-naphthalene tetracarboxylic dianhydride, and 1,2,4,5-benzenetetracarboxylic acid. Examples thereof include aromatic carboxylic dianhydrides having 10 to 14 carbon atoms such as dianhydrides.

On the other hand, examples of the aliphatic carboxylic dianhydride include cyclobutane-1,2,3,4-tetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride, and methylcyclohexene. Examples thereof include aliphatic carboxylic dianhydrides having 8 to 11 carbon atoms such as tetracarboxylic dianhydrides.
In order to partially imidize the polyamic acid, for example, a method of heating a polyamic acid solution, a method of adding a dehydrating agent, or the like is used.

  And photocurable polyimide resin is obtained by introduce | transducing a photosensitive group into such a polyimide precursor. Specifically, a polyimide resin obtained by mixing a polyimide precursor with a compound having a tertiary amine and a (meth) acryloyl group, a (meth) acryloyl group via an ester bond to the carboxyl group of the polyimide precursor. Obtained by mixing a polyimide resin obtained by introduction, a polyimide resin obtained by introducing an isocyanate compound having a (meth) acryloyl group into the carboxyl group of the polyimide precursor, a polyimide precursor and a (meth) acrylic compound Polyimide resin, polyimide resin obtained by mixing polyimide precursor and photoacid generator, polyimide resin obtained by mixing polyimide precursor and photobase generator, polyimide precursor and diazonaphthoquinone derivative Polyimide resin obtained by mixing with benzophenone skeleton A polyimide resin composed of a imide precursor, a polyimide resin obtained by mixing a polyimide precursor, a methylol crosslinking agent and a photoacid generator, a polyimide precursor having a phenolic hydroxyl group, and a diazonaphthoquinone derivative. And polyimide resins obtained in this way.

Such photo-curing resins are all uncured, and the support portion 40 is formed by curing them. That is, the support part 40 is comprised with the hardened | cured material of photocurable resin as mentioned above.
In addition, a commercially available thing is used for the said photocurable (photosensitive) polyimide-type resin. For example, Toray Co., Ltd. Photo Nice, Asahi Kasei Co., Ltd. Pimel, Hitachi Chemical DuPont Microsystems Co., Ltd. HD series, Nissan Chemical Co., Ltd. RN series, Nitto Denko Co., Ltd. JR series, Arch Chemical Probimide (probe) Imide) series, Durimide series, and the like.

In addition, as the above-described photocurable resin, a positive type or a negative type is used. In this case, the exposure areas are different from each other.
A piezoelectric element (vibrating means) 50 is bonded to a part of the upper surface of the support portion 40 (in FIG. 1, near the central portion of the upper surface of the support portion 40).
The piezoelectric element 50 is constituted by a laminate of a piezoelectric layer 51 made of a piezoelectric material and an electrode film 52 that applies a voltage to the piezoelectric layer 51. In such a piezoelectric element 50, when a voltage is applied to the piezoelectric layer 51 through the electrode film 52, a distortion corresponding to the voltage is generated in the piezoelectric layer 51 (reverse piezoelectric effect). This distortion causes the vibration film 30 to bend (vibrate) via the support portion 40 and change the volume of the discharge liquid storage chamber 21. Since the piezoelectric element 50 having such a configuration is reliably joined to the support portion 40, the distortion generated in the piezoelectric element 50 can be reliably converted into the displacement of the vibration film 30 via the support portion 40. As a result, the volume of each discharge liquid storage chamber 21 is reliably changed.

  In addition, the stacking direction of the piezoelectric layer 51 and the electrode film 52 is not particularly limited, and may be a direction parallel to or perpendicular to the upper surface of the support portion 40. In addition, when the stacking direction of the piezoelectric layer 51 and the electrode film 52 is a direction orthogonal to the upper surface of the support portion 40 as shown in FIG. 1, the piezoelectric element 50 arranged in this way is particularly MLP. (Multi Layer Piezo). If the piezoelectric element 50 is an MLP, the displacement amount of the support portion 40 can be increased, and there is an advantage that the adjustment range of the ink discharge amount is large.

The surface of the piezoelectric element 50 adjacent to (in contact with) the support portion 40 differs depending on the arrangement method of the piezoelectric element 50, but the surface on which the piezoelectric layer is exposed, the surface on which the electrode film is exposed, or the piezoelectric layer and the electrode Either side of the membrane is exposed.
As a material constituting the piezoelectric layer 51 in the piezoelectric element 50, for example, barium titanate, lead zirconate, lead zirconate titanate, zinc oxide, aluminum nitride, lithium tantalate, lithium niobate, crystal, and the like are available. Can be mentioned.

On the other hand, as a material constituting the electrode film 52, for example, various metal materials such as Fe, Ni, Co, Zn, Pt, Au, Ag, Cu, Pd, Al, W, Ti, Mo, or an alloy containing them. Is mentioned.
Here, the support portion 40 described above has an island shape provided at a position corresponding to the piezoelectric element 50. That is, the support part 40 is provided in a part on the vibration film 30 and is isolated in an island shape with the annular recess 53 interposed therebetween. By adopting a configuration in which the piezoelectric element 50 is joined to such an island-shaped portion, distortion generated in the piezoelectric element 50 can be more reliably propagated to the vibration film 30, so that the bending in the vibration film 30 is prevented. It will occur more reliably.

The electrode film 52 of the piezoelectric element 50 is electrically connected to a drive IC (not shown). Thereby, the operation of the piezoelectric element 50 can be controlled by the driving IC.
Further, in addition to the support portion 40, a support portion 41 is provided on a part of the upper surface of the vibration film 30 with a concave portion 53 being provided with respect to the support portion 40. This support portion 41 can also be formed in the same manner as the support portion 40.

A case head 60 is joined to the support portion 41. In this way, the case head 60 and the support portion 41 are joined to reinforce a so-called cavity portion composed of a laminated body of the nozzle plate 10, the substrate 20, the vibration film 30 and the support portion 41. The tee portion can be reliably prevented from being twisted or warped.
Examples of the material constituting the case head 60 include a silicon material, a metal material, a glass material, a ceramic material, a carbon material, a resin material, or a combination of one or more of these materials as described above. Materials and the like.

Among these, the constituent material of the case head 60 is preferably polyphenylene sulfide (PPS), a modified polyphenylene ether resin such as Zylon (“Zylon” is a registered trademark), or stainless steel. Since these materials have sufficient rigidity, they are suitable as constituent materials for the case head 60 that supports the head 1.
Further, the vibration film 30 and the support portion 41 have a through hole 23 at a position corresponding to the discharge liquid supply chamber 22. Through the through hole 23, the discharge liquid supply path 61 provided in the case head 60 and the discharge liquid supply chamber 22 communicate with each other. The discharge liquid supply path 61 and the discharge liquid supply chamber 22 constitute a part of a reservoir 70 that functions as a common ink chamber that supplies ink to the plurality of discharge liquid storage chambers 21.

  In such a head 1, after taking ink from an external discharge liquid supply means (not shown) and filling the interior from the reservoir 70 to the nozzle hole 11 with the ink, each discharge liquid storage chamber 21 is received by a recording signal from the drive IC. Each piezoelectric element 50 corresponding to is operated. Accordingly, the vibration film 30 is bent (vibrated) via the support portion 40 due to the reverse piezoelectric effect of the piezoelectric element 50. As a result, for example, when the volume in each discharge liquid storage chamber 21 contracts, the pressure in each discharge liquid storage chamber 21 increases instantaneously, and ink is pushed out (discharged) from the nozzle hole 11 as a droplet.

In this way, in the head 1, by applying a voltage to the piezoelectric element 50 at a position to be printed via the driving IC, that is, by sequentially inputting the ejection signal, an arbitrary character can print a figure or the like. it can.
The head 1 is not limited to the configuration described above, and may include, for example, an electrostatic actuator instead of the piezoelectric element 50 serving as a vibration unit.
However, as in the present embodiment, since the vibration means is configured by a piezoelectric element, the degree of bending that occurs in the vibration film 30 can be easily controlled. As a result, the size of the ink droplet can be easily controlled.

<Method for producing ink jet recording head>
Next, a method for manufacturing a droplet discharge head including the method for manufacturing a diaphragm for a droplet discharge head according to the present invention will be described. In the following, a case where the method for manufacturing a droplet discharge head is applied to a method for manufacturing an ink jet recording head will be described as an example.
3 to 6 are views (longitudinal sectional views) for explaining a method of manufacturing an ink jet recording head. In the following description, the upper side in FIGS. 3 to 6 is referred to as “upper” and the lower side is referred to as “lower”.

  The manufacturing method of the head 1 according to the present embodiment includes: [1] a step of applying an uncured photocurable resin to one surface of the vibration film 30, and [2] exposing and curing a part of the coating film. A step, [3] a step of removing an uncured portion of the coating film to obtain the vibration plate 35, [4] a step of bonding the vibration plate 35 and the substrate 20, and [5] a nozzle plate to the substrate 20. 10 is bonded.

Hereinafter, each process will be described sequentially.
[1] First, a liquid material containing an uncured photocurable resin is applied to one surface of the vibration film 30. Thereby, as shown in FIG. 3A, a coating film 45 is obtained on one surface of the vibration film 30.
For example, when the uncured photocurable resin is in a liquid state, the liquid raw material is used as it is as a raw material or diluted with a solvent, and the uncured photocurable resin is semi-cured (B (Stage) In the case of powder, a material in which it is dispersed in a dispersion medium is used as a raw material.

When diluting the uncured product or dispersing the uncured powder in the dispersion medium, the solid content concentration in the liquid raw material is preferably 5% by mass or more and 50% by mass or less, preferably 10% by mass or more and 40% by mass. It is more preferable that the amount is not more than mass%.
Examples of the solvent and dispersion medium include water, alcohols, phenol solvents such as p-chlorophenol and m-cresol, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, Amide solvents such as N-dimethylformamide, cyclic ester solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, and α-methyl-γ-ptyrolactone are used. .

The liquid raw material may be applied to one surface of the vibration film 30 by any method, for example, screen printing, gravure printing, microgravure, dip coat printing, bar coater coating, roll coater coating. And various methods such as lip coater coating and spray coater coating.
In addition, the application surface of the vibration film 30 may be subjected to a surface treatment as necessary. Examples of the surface treatment include corona discharge treatment, plasma discharge treatment, ultraviolet irradiation treatment, ozone treatment, and ultrasonic cleaning.

Moreover, after application | coating of a liquid raw material, drying is performed as needed. The drying temperature is preferably 40 ° C. or higher and 200 ° C. or lower, and more preferably 50 ° C. or higher and 170 ° C. or lower. The drying time is preferably 10 seconds or more and 3600 seconds or less, and more preferably 20 seconds or more and 1800 seconds or less.
In addition, you may make it add a photoinitiator, a sensitizer, a photocrosslinking agent, a thixotropy imparting agent, an antifoamer, a hardening | curing agent etc. in a liquid raw material as needed.

  Examples of the photopolymerization initiator and sensitizer include Michler's ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, 4, 4'-bis (diethylamino) benzophenone, acetophenone, thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, [4- (methylphenylthio) phenyl] phenylmethane, p-dimethylaminobenzoic acid isoamyl ester, p-dimethyl Aminobenzoic acid ethyl ester, 1,5-acenaphthene, 1-hydroxy-cyclohexyl phenyl ketone, 2-benzyl-1,2-dimethylamino-1- (4-morpholinophenyl) butane-1,1-hydroxy- Black hexylphenyl ketone.

In addition, content of the photoinitiator and sensitizer in a liquid raw material is the sum total of a photoinitiator and a sensitizer, and is 1 to 30 mass parts with respect to 100 mass parts of photocurable polyimide resin. It is preferably about 2 parts by mass or more and about 15 parts by mass or less.
Examples of the photocrosslinking agent include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, and phosphoric acid (meth) acrylate.

In addition, it is preferable that it is about 30 mass parts or less with respect to 100 mass parts of photocurable polyimide resin, and, as for content of the photocrosslinking agent in a liquid raw material, it is more preferable that it is about 15 mass parts or less.
Examples of the thixotropy-imparting agent include aerosil, mica, talc, barium sulfate, wollastonite and the like, and the addition amount thereof is 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the photocurable polyimide resin. It is preferable that the amount is about part or less.
Furthermore, examples of the curing agent include various epoxy resins such as O-cresol novolac type epoxy resin and biphenol type epoxy resin, and the addition amount thereof is 3 with respect to 100 parts by mass of the photocurable polyimide resin. It is preferable that it is about 20 parts by mass or more.

[2] Next, as shown in FIG. 3B, a part of the coating film 45 obtained is exposed. As a result, the exposed region is cured (see FIG. 3C). In the following description, the case where a negative type is used as the photocurable polyimide resin will be described. However, the positive type is the same as the negative type except that the exposure area is different.
Any light source that can irradiate ultraviolet rays is used for the exposure, and for example, a UV lamp, a UV-LED, a UV laser, or the like is used. In addition, various steppers, various scanners, various aligners, and the like can be used as the exposure apparatus.

In the exposure, a part of the coating film 45 is covered with a mask 46. Since the exposure region can be easily selected by using the mask 46, the planar view shape of the support portion 40 can be easily adjusted with high accuracy.
In this case, various photomasks are used. Note that the mask 46 can be omitted when the directivity of the light source is high.

The wavelength of the ultraviolet light is not particularly limited, but is preferably about 150 nm or more and 450 nm or less.
Further, the integrated light quantity per unit area is preferably on the order 50 mJ / cm ² or more 500 mJ / cm ² or less, and more preferably of the order 70 mJ / cm ² or more 300 mJ / cm ² or less.
By such exposure, only the exposed region of the coating film is cured.

[3] Next, the uncured portion of the coating film 45 is removed (development). Thereby, the diaphragm 35 which has the support part 40 and the support part 41 which are shown in FIG.3 (d) is obtained.
A general developer is used to remove the uncured portion. Examples of the developer include dipolar aprotic solvents such as N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, sulfolane, N, N-diethylformamide, methanol, ethanol, isopropyl Liquid mixture with lower alcohol such as alcohol, liquid mixture of dipolar aprotic solvent and water, liquid mixture of dipolar aprotic solvent, aromatic hydrocarbon and water, dipolar aprotic solvent and ester In addition to a mixed solution of a compound (propylene carbonate, propylene glycol monomethyl ether acetate, etc.) and water, cyclohexanone, cyclopentanone and the like can be mentioned.

In addition, a rinsing solution is used to remove the developer after development. As the rinse liquid, for example, lower alcohols such as methanol, ethanol, and isopropyl alcohol are used.
The application of the developer or the rinsing liquid can be performed by, for example, a processing method such as a process of immersing an object to be processed in a processing liquid, a process of irradiating ultrasonic waves while being immersed, or a process of spraying a processing liquid.
Further, after development, heat treatment may be performed as necessary. The heating temperature at this time is preferably about 200 ° C. or more and 500 ° C. or less, and more preferably about 300 ° C. or more and 400 ° C. or less. The heating time is preferably about 10 seconds to 600 seconds, more preferably about 20 seconds to 180 seconds.

  As described above, the support part 40 formed through exposure and development has extremely high dimensional accuracy. For this reason, the dimensions as designed can be faithfully reproduced, which contributes to the realization of the diaphragm 35 having the vibration characteristics as designed. Such a vibration plate 35 contributes to the realization of the head 1 capable of accurately ejecting ink because its vibration characteristics are very close to the design values. In addition, since individual differences in the dimensions and vibration characteristics of the vibration plate 35 are extremely small, individual differences in ink discharge performance in the head 1 can be suppressed.

As an example, it is preferable that the projected shape of the support portion 40 matches the shape of the lower surface of the piezoelectric element 50. However, according to the present invention, the matching of such shapes can be reliably realized.
The average thickness of the support portions 40 and 41 thus obtained is not particularly limited, but is preferably about 5 μm to 300 μm, and more preferably about 10 μm to 200 μm.

[4] Next, the diaphragm 35 and the substrate 20 are bonded.
[4-1] As the substrate 20, a flat base material 20 'as shown in FIG. 4 (a) is prepared, and the substrate 20 is processed to each discharge liquid storage chamber as shown in FIG. 4 (b). 21 and the discharge liquid supply chamber 22 are formed.
The formation of the discharge liquid storage chamber 21 and the discharge liquid supply chamber 22 is one of physical etching methods such as dry etching, reactive ion etching, beam etching, and light-assisted etching, and chemical etching methods such as wet etching. Or it can carry out using combining 2 or more types.

Next, the vibration plate 35 and the substrate 20 are laminated through the adhesive layer 25, and the obtained laminated body is pressed in the thickness direction. Thereby, as shown in FIG. 4C, the vibration plate 35 (vibration film 30) and the substrate 20 are bonded via the adhesive layer 25.
The pressure at the time of pressurization is not particularly limited and is appropriately set according to the material of the adherend member, but is preferably 0.01 MPa or more and 10 MPa or less, more preferably 0.05 MPa or more and 5 MPa or less. preferable. Thereby, necessary and sufficient adhesive force is obtained in the adhesive layer 25.

Further, the pressure treatment is performed under heating as necessary. The heating temperature at that time is preferably 80 ° C. or higher and 300 ° C. or lower, and more preferably 100 ° C. or higher and 250 ° C. or lower.
The pressurization time is preferably 0.1 second or more and 20 seconds or less, more preferably 0.5 second or more and 10 seconds or less. Thereby, it is possible to efficiently and firmly bond without altering the member to be bonded.
Examples of the adhesive constituting the adhesive layer 25 include acrylic adhesives, urethane adhesives, silicone adhesives, epoxy adhesives, thermoplastic polyimide adhesives, and various hot melt adhesives (polyester adhesives). , Modified olefin type) and the like.

[4-2] Subsequently, as shown in FIG. 5A, the vibration film 30 and the support portion 41 are located at positions corresponding to the discharge liquid supply chamber 22 of the substrate 20, that is, in the discharge liquid supply chamber 22. A through hole 23 is formed so as to communicate with each other.
The through hole 23 can be formed by, for example, laser processing, mechanical processing, various etching processing, and the like.

[4-3] Next, the piezoelectric element 50 is prepared, and the piezoelectric element 50 is bonded to the support portion 40, so that the diaphragm 35 and the piezoelectric element 50 are bonded as shown in FIG. The various adhesives mentioned above can be used for this adhesion.
[4-4] Next, the case head 60 is prepared, and the case head 60 is joined to the upper surface of the diaphragm 35 to join the diaphragm and the case head 60 as shown in FIG. .

At this time, the discharge liquid supply chamber 22 communicates with the through hole 23 provided in the vibration plate 35 and the discharge liquid supply path 61 provided in the case head 60, whereby a reservoir 70 is formed.
In the above description, the diaphragm 35, the piezoelectric element 50, and the case head 60 are attached to the substrate 20 on which the base material 20 ′ has been previously processed to form the discharge liquid storage chambers 21 and the discharge liquid supply chambers 22. Although the case of bonding is described, the manufacturing method of the head 1 is not limited to this, and after bonding the diaphragm 35 to the base material 20 ′, the base material 20 ′ is processed, and each discharge liquid storage chamber 21. Alternatively, the discharge liquid supply chamber 22 may be formed to obtain the substrate 20.

[5] Next, the nozzle plate 10 is prepared, and the substrate 20 and the nozzle plate 10 are bonded via the adhesive layer 15 as shown in FIG. Thereby, the head 1 is obtained.
The configuration of the adhesive layer 15 is the same as that of the adhesive layer 25 described above.

(Second Embodiment)
Next, a second embodiment of the droplet discharge head of the present invention will be described.
Hereinafter, although 2nd Embodiment is described, it demonstrates centering around difference with 1st Embodiment, The description is abbreviate | omitted about the same matter.
FIG. 7 is a perspective view showing a diaphragm provided in the second embodiment of the droplet discharge head of the present invention.
The diaphragm 35 shown in FIG. 7 is the same as that of the first embodiment except that the support part 40 has a recess 401 whose upper surface is recessed in the vicinity of the center part in plan view.

  The concave portion 401 is located substantially at the center of the support portion 40 in plan view. By providing such a recess 401, an adhesive used for bonding to the piezoelectric element 50 enters the recess 401. For this reason, since not only the upper surface of the support part 40 but the inner wall surface of the recessed part 401 contributes to adhesion | attachment for both adhesion | attachment, an adhesion area becomes large substantially. As a result, since the substantial adhesion area can be expanded without increasing the projected area of the adhesion region, the reliability of the head 1 can be improved without deteriorating the vibration characteristics.

  Further, by providing the recess 401, it becomes possible to store the adhesive in the recess 401. Thereby, even when there is too much adhesive bonding between the support portion 40 and the piezoelectric element 50, the surplus portion is not protruded outside the support portion 40 but is pushed into the recess 401 and filled. Will be able to. As a result, it is possible to prevent the adhesive from protruding, and to prevent the vibration characteristics of the diaphragm 35 from deviating from the design value.

In addition, when bonding the support part 40 and the piezoelectric element 50, an adhesive is placed on the upper surface of the support part 40, and then the adhesive is pushed out by pressure contact between the support part 40 and the piezoelectric element 50. However, it is possible to reliably prevent the adhesive from protruding outside the support portion 40 by placing the adhesive in the recess 401.
Such a recess 401 is easily formed by selecting an exposure region of the coating film 45 when the support portion 40 is formed.

  The shape of the concave portion 401 in a plan view is not particularly limited, and may be a polygonal shape such as a triangle, a quadrangle, or a pentagon, or a star shape, but preferably various circles such as a perfect circle, an ellipse, and an ellipse. It is said. If it is circular, it is easy to relieve stress concentration at the interface between the adhesive and the support portion 40. For this reason, it is possible to reliably prevent problems such as peeling of the bonded portion and a decrease in adhesive force due to stress concentration.

The position of the recess 401 is not limited to this, but is preferably a position other than the edge. Thereby, the recessed part 401 becomes a shape which can accumulate | store an adhesive agent reliably, and can enjoy the said effect reliably.
As mentioned above, although this invention was demonstrated based on embodiment of illustration, this invention is not limited to these.

Next, specific examples of the present invention will be described.
1. Production of inkjet recording head (Example 1)
<1> First, a vibration film made of polyphenylene sulfide (PPS) was prepared, and a liquid raw material for an adhesive layer was applied to one surface thereof by a microgravure method. Thereby, a coating film was obtained. The application surface of the vibration film was previously subjected to corona discharge treatment. As the liquid raw material, a photosensitive polyimide varnish “Photo Nice UR-3100E” manufactured by Toray Industries, Inc. diluted 5 times by mass with N-methyl-2-pyrrolidone was used.
Thereafter, the obtained coating film was dried by heating at 80 ° C. for 12 minutes.

<2> Next, the coating film was irradiated with ultraviolet rays through a mask. This cured the exposed area. The wavelength of ultraviolet rays was 365 nm, and the integrated light quantity was 100 mJ / cm ² .
<3> Next, the cured film after exposure was developed. A developer DV-605 manufactured by Toray Industries, Inc. was used as the developer.
Further, the cured film after development was washed with a rinse solution. Isopropyl alcohol was used as the rinse solution.
Thereafter, the cured film was subjected to heat treatment. The heating temperature was 200 ° C. and the heating time was 4 minutes.
Thus, a diaphragm having a support portion having a predetermined shape on one surface of the vibration film was obtained. In addition, the thickness of the obtained support part was 100 micrometers.

<4> Next, a base material made of single crystal silicon was prepared, and the base material was processed by photolithography technique and etching technique to form each discharge liquid storage chamber and discharge liquid supply chamber. Thereby, a discharge liquid storage chamber forming substrate was obtained.
Next, the vibration plate and the discharge liquid storage chamber forming substrate were laminated via an epoxy adhesive. And the diaphragm and the discharge liquid storage chamber formation board | substrate were adhere | attached by pressurizing for 2 second at the pressure of 0.15 MPa and the temperature of 200 degreeC in the thickness direction.
The diaphragm was laser processed to form a through hole communicating with the discharge liquid supply chamber.
Thereafter, a piezoelectric element and a case head were prepared, and these were also bonded using the same adhesive layer as the above adhesive layer.

<5> Next, a stainless steel nozzle plate was prepared, and the nozzle plate and the discharge liquid storage chamber forming substrate were laminated via an epoxy adhesive. Then, the discharge liquid storage chamber forming substrate and the nozzle plate were bonded by pressurizing for 2 seconds at a pressure of 0.15 MPa and a temperature of 200 ° C. in the thickness direction.
An ink jet recording head was obtained as described above.

(Examples 2-9)
An ink jet recording head was obtained in the same manner as in Example 1 except that the configuration of the support portion of the diaphragm was changed as shown in Table 1.

(Comparative Example 1)
An ink jet recording head was obtained in the same manner as in Example 1 except that a photocurable resin was not used in the production of the diaphragm and a stainless steel foil was used instead. This manufacturing process is as follows.
<1> First, a vibration film made of polyphenylene sulfide (PPS) was prepared, and an epoxy adhesive was applied to one surface thereof. The application surface of the vibration film was previously subjected to corona discharge treatment.

<2> Next, a stainless steel foil having an average thickness of 100 μm was prepared as a support plate forming substrate. And stainless steel foil was laminated | stacked through the adhesive agent formed into the film on one side of the vibration film. Then, the vibration film and the stainless steel foil were bonded by pressurizing in the thickness direction at a pressure of 0.15 MPa and a temperature of 200 ° C. for 2 seconds.
Next, after a resist film was formed on the stainless steel foil, the resist film was patterned by a photolithography technique and an etching technique. Then, the stainless steel foil was etched using the patterned resist film as a mask, and patterned into a predetermined shape. In addition, a through hole for the reservoir was formed by etching. Thereafter, the resist film was removed to obtain a diaphragm. In addition, in the obtained diaphragm, it is comprised with the laminated body of a vibration film and an adhesive bond layer, and becomes the structure by which the stainless steel foil etched on one part of the upper surface was mounted.

<3> Next, a base material made of single crystal silicon was prepared, and the base material was processed by photolithography technique and etching technique to form each discharge liquid storage chamber and discharge liquid supply chamber. Thereby, a discharge liquid storage chamber forming substrate was obtained.
Next, a discharge liquid storage chamber forming substrate was laminated via an adhesive layer formed on the other surface of the vibration film. And the vibration film and the discharge liquid storage chamber formation board | substrate were adhere | attached by pressurizing for 2 second at the pressure of 0.15 MPa and the temperature of 200 degreeC in the thickness direction.
In addition, a piezoelectric element and a case head were prepared, and these were also bonded using the same adhesive layer as the above adhesive layer.

<4> Next, a stainless steel nozzle plate was prepared, and an adhesive layer having an average thickness of 5 μm made of the same polyolefin-based resin as described above was formed on one surface thereof. And the nozzle plate and the discharge liquid storage chamber formation board | substrate were laminated | stacked through the formed adhesive layer. Then, the discharge liquid storage chamber forming substrate and the nozzle plate were bonded by pressurizing for 2 seconds at a pressure of 0.15 MPa and a temperature of 200 ° C. in the thickness direction.
An ink jet recording head was obtained as described above.

(Comparative Example 2)
An ink jet recording head was obtained in the same manner as in Example 1 except that a urethane adhesive was used instead of the epoxy adhesive.
(Comparative Example 3)
Inkjet recording head as in Comparative Example 1 except that after the stainless steel foil was etched, a treatment liquid for removing the exposed adhesive was applied to remove the adhesive not hidden behind the support. Got.
(Comparative Example 4)
Inkjet recording head as in Comparative Example 2, except that after the stainless steel foil was etched, a treatment liquid for removing the exposed adhesive was applied to remove the adhesive not hidden behind the support. Got.

2. Evaluation of Inkjet Recording Head Using the inkjet recording head obtained in each Example and each Comparative Example, an ejection operation was performed in which the ink composed of N-methyl-2-pyrrolidone was continuously ejected on the substrate for 1 hour.
Thereafter, the following evaluation (first time) was performed on the behavior of the head and ink when the ejection was temporarily stopped and ejected again.
Next, an ejection operation for continuing to eject the ink again for 999 hours was performed.
Thereafter, the following evaluation (second time) was performed on the behavior of the head and ink when the ejection was temporarily stopped and ejected again.

2-1. Evaluation of Variation in Ink Ejection Speed First, variation in the average value of the speed of ink ejected from the ink jet recording head was measured. And the measurement result was evaluated according to the evaluation criteria shown below.
<Evaluation criteria for fluctuations in discharge speed>
A: Speed variation is less than ± 2% B: Speed variation is ± 2% or more and less than 5% C: Speed variation is ± 5% or more and less than 10% D: Speed variation is ± 10% or more and less than 20% E : Speed variation is ± 20% or more, or an ejection port that does not eject ink occurs

2-2. Evaluation of Inflection of Ink Flight Next, the amount of deviation of the landing position of the ink ejected from the ink jet recording head was measured. And the measurement result was evaluated according to the evaluation criteria shown below.
<Evaluation criteria for flight curve>
A: Flight curve is less than 5 μm B: Flight curve is from 5 μm to less than 10 μm C: Flight curve is from 10 μm to less than 20 μm D: Flight curve is from 20 μm to less than 30 μm E: Flight curve is from 30 μm to less than 40 μm

2-3. Evaluation of frequency correction Next, regarding the voltage applied to the piezoelectric element that vibrates the vibration plate of the ink jet recording head, correction of the voltage necessary to stabilize the ink ejection operation (to stabilize vibration of the vibration plate) The amount was measured. And the measurement result was evaluated according to the evaluation criteria shown below.

<Evaluation criteria for frequency correction>
A: Frequency correction by voltage is less than 2 V B: Frequency correction by voltage is 2 V or more and less than 5 V C: Frequency correction by voltage is 5 V or more, or stable operation is difficult even if the voltage waveform is corrected

2-4. Evaluation results Table 2 shows the evaluation results obtained from 2-1 to 2-3.

  As is apparent from Table 2, the ink jet recording head obtained in each example has little variation in ink ejection speed and ink flight curve even in the initial state and after continuous driving for a long time, and is necessary. As a result, the correction amount of a large voltage was small. This is because, in each head, the support portion in the diaphragm has high dimensional accuracy and high isotropic mechanical characteristics, and further, no adhesive is required and the flexibility of the diaphragm is not hindered. This is presumably because the excellent vibration characteristics are maintained over a long period of time.

On the other hand, in the ink jet recording heads obtained in the respective comparative examples, there were many variations in the ink ejection speed and ink flight bends both in the initial state and after continuous driving over a long period of time. Further, in order to stabilize the ink ejection operation, a larger voltage correction is required.
In addition, in the ink jet recording heads obtained in the respective examples, compared to the ink jet recording heads obtained in Comparative Examples 1 and 2, the amount of ejected ink was large even with the same drive voltage. This is considered due to a difference in vibration characteristics such as the amplitude of the diaphragm.

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording head 10 ... Nozzle plate 11 ... Nozzle hole 15, 25 ... Adhesive layer 20 ... Discharge liquid storage chamber forming substrate 20 '... Base material 21 ... Discharge liquid storage chamber 22 ... Discharge Liquid supply chamber 23 …… Through hole 30 …… Vibrating film 35 …… Vibrating plate 40, 41 …… Supporting portion 401 …… Concavity 45 …… Coating film 46 …… Mask 50 …… Piezoelectric element 51 …… Piezoelectric layer 52 ... Electrode film 53 ... Recess 60 ... Case head 61 ... Discharge liquid supply path 70 ... Reservoir 9 ... Inkjet printer 92 ... Device main body 921 ... Tray 922 ... Paper discharge port 93 ... Head unit 931 …… Ink cartridge 932 …… Carriage 94 …… Printing device 941 …… Carriage motor 942 …… Reciprocating mechanism 943 …… Carriage Ridge guide shaft 944 ... Timing belt 95 ... Paper feed device 951 ... Paper feed motor 952 ... Paper feed roller 952a ... Driven roller 952b ... Drive roller 96 ... Control unit 97 ... Control panel P ... Recording Paper

Claims (10)

A diaphragm for a droplet discharge head that is displaced according to the vibration of the vibration means and changes the volume of a discharge liquid storage chamber that stores the discharge liquid,
A vibration film made of a resin material;
Provided on a part of one surface of the vibration film, and having a support portion for transmitting the vibration of the vibration means to the vibration film,
The diaphragm for a droplet discharge head, wherein the support portion is made of a photocurable resin.   The support portion is obtained by applying an uncured photocurable resin on one surface of the vibration film to obtain a coating film, and then exposing and curing a part of the coating film. The diaphragm for a droplet discharge head according to claim 1.   The diaphragm for a droplet discharge head according to claim 1, wherein the photocurable resin is composed mainly of a polyimide resin.   The droplet ejection head diaphragm according to any one of claims 1 to 3, wherein the support portion has a recessed portion whose surface is recessed in a region other than the edge portion in a plan view.   The diaphragm for a droplet discharge head according to claim 4, wherein the concave portion is a perfect circle, an ellipse, or an ellipse in a plan view.   The diaphragm for a droplet discharge head according to any one of claims 1 to 5, wherein the resin material constituting the vibration film is polyphenylene sulfide. A method of manufacturing a diaphragm for a droplet discharge head that is displaced according to vibration of a vibration means and changes a volume of a discharge liquid storage chamber for storing discharge liquid,
On one surface of the vibration film made of a resin material, a step of applying an uncured photocurable resin to obtain a coating film;
Exposing and curing a part of the coating film, and obtaining a support portion that transmits vibrations of the vibration means to the vibration film;
And a step of removing the portion of the coating film that has not been cured by the exposure. A method for manufacturing a diaphragm for a droplet discharge head, comprising:   The method for manufacturing a diaphragm for a droplet discharge head according to claim 7, wherein the step of exposing part of the coating film is performed by placing a mask on the coating film and performing exposure. A substrate on which a discharge liquid storage chamber for storing the discharge liquid is formed;
A nozzle plate that is provided on one surface of the substrate so as to cover the discharge liquid storage chamber and includes nozzle holes for discharging the discharge liquid as droplets;
A diaphragm provided on the other surface of the substrate so as to cover the discharge liquid storage chamber;
A liquid droplet ejection head having vibration means provided on the opposite side of the vibration plate from the substrate,
The vibration plate includes a vibration film, and a support portion provided on a part of one surface of the vibration film so as to contact the vibration means between the vibration film and the vibration means. Yes,
The droplet discharge head is characterized in that the support portion is made of a photocurable resin.   A droplet discharge apparatus comprising the droplet discharge head according to claim 9.

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