JP2009220412A - Droplet discharge head, droplet discharge head manufacturing method, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a droplet discharge head which can retain water repellency for a long time, and an image forming device with the head. <P>SOLUTION: The droplet discharge head has a SiO<SB>2</SB>layer 32 formed on the nozzle forming surface of a nozzle base material 31 made of a metal material as a continuous film, a water repellent layer 33 formed on the SiO<SB>2</SB>layer 32. The water repellent layer 33 contains a compound having at least one perfluoroalkyl group and at least one alkoxy silyl group. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a droplet discharge head, a manufacturing method thereof, and an image forming apparatus including the droplet discharge head. Specifically, the present invention relates to a technique for improving the durability of a water-repellent layer formed on a nozzle forming surface and maintaining water-repellent performance for a long time in an image forming apparatus such as an ink jet printer or a copying apparatus.

Conventionally, a droplet discharge head of an ink jet recording apparatus or the like has a configuration in which ink droplets are discharged from a nozzle to perform recording. Therefore, the shape and accuracy of the nozzle have a great influence on the droplet ejection characteristics. .
In particular, the surface characteristics of the nozzle forming member also affect the direction of droplet ejection, the size of the droplets, and the flying speed.
Therefore, conventionally, a technology for forming a predetermined water-repellent layer on the ink ejection surface side of the nozzles constituting the droplet ejection head has been proposed to improve the uniformity of the surface of the nozzle forming member and the ink droplet flight characteristics. Was intended to stabilize.

For example, Patent Document 1 below discloses that the surface of a nozzle forming member made of a resin material is coated with a fluorine resin, and that an SiO ₂ layer is provided between the nozzle forming member and the fluorine resin.
However, in this technique, since the nozzle forming member is formed of a resin material, the ink resistance against oil-based ink and solvent-based ink is insufficient.

On the other hand, Patent Document 2 below proposes a technique in which a metal material is applied as a nozzle forming member.
Further, in Patent Document 2 below, an ink repellent layer in which a nozzle surface is flattened, a SiO ₂ layer is formed thereon, and a compound having an alkoxysilane residue at the end of a perfluoropolyether chain is further bonded thereto. Technical disclosure has been made on a nozzle surface that maintains ink repellency, in a configuration in which the above is provided.
However, a compound having an alkoxysilane residue at the end of the perfluoropolyether chain is coupled between molecules bonded to SiO _{2 of the} SiO ₂ layer corresponding to the underlayer, and only adheres to the nozzle surface. It is coexisting with what is.
For this reason, it is easily removed by friction by wiping, and the durability of ink repellency is not satisfactory in practice.

  As described above, it has been a conventional problem to impart water repellency to the nozzle surface of the droplet discharge head and to have high durability.

By the way, in order to ensure ink resistance against oil-based ink and solvent-based ink, a metal material is suitable for the nozzle forming member, but in order to improve the adhesion to the resinous water repellent material, It is said that it is necessary to form a SiO ₂ layer as an intermediate layer.
The SiO ₂ layer formed on the metal material is in close contact by a hydrogen bond or a metallosiloxane bond ((metal) -O—Si).
However, a hydrogen bond or a metallosiloxane bond has a problem that peeling is likely to occur due to water intrusion or hydrolysis at the interface and subsequent volume change of the surface due to metal oxidation. For example, in the case of hydrogen bonding, peeling occurs as shown in FIGS.
The surface of the droplet discharge nozzle is in direct contact with the liquid, and wiping treatment is indispensable for removing ink droplets and dust. However, liquid repellency decreases with time due to this friction.

As described above, when a metal material is applied as the nozzle forming member and a water repellent layer is provided on the surface, the adhesion between the metal material and the SiO ₂ layer is increased, and the durability of the upper water repellent layer is further increased. It was an important technical issue.

JP 2003-341070 A JP 2006-44226 A

Therefore, in the present invention, when a metal material is applied to the nozzle forming member, an SiO ₂ layer is provided as an intermediate layer in order to improve the adhesion of the water repellent layer on the nozzle surface, and the nozzle forming member and the SiO ₂ layer are provided. It is an object of the present invention to provide a droplet discharge head that can maintain high water repellency even when used repeatedly for a long time as a whole.

According to the first aspect of the present invention, a droplet discharge head comprising a nozzle substrate made of a metal material and a nozzle for discharging droplets, wherein a water repellent layer is formed on the droplet discharge surface side of the nozzle substrate. An SiO ₂ layer is formed as a continuous film between the nozzle base material and the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer. The layer provides a droplet discharge head characterized in that the layer contains a compound having at least one perfluoroalkyl group and at least one alkoxysilyl group.

According to a second aspect of the present invention, there is provided the liquid droplet ejection head according to the first aspect, wherein the SiO ₂ layer has an average film thickness of 100 nm or more.

According to a third aspect of the present invention, there is provided the liquid droplet ejection head according to the first or second aspect, wherein the film thickness of the water repellent layer is not less than the surface roughness (Ra) of the SiO ₂ layer. To do.

According to a fourth aspect of the present invention, a metal layer is provided as an underlayer for the SiO ₂ layer, and the metal layer includes Ta, Al, V, Cr, Zr, Ti, W, Fe, Mo, Mg, Ni, Co 4. The droplet discharge head according to claim 1, wherein the droplet discharge head is formed of any one of Sn, Zn, Cd, Pd, Pb, Cu, and Ag.

  According to a fifth aspect of the invention, there is provided the liquid droplet ejection head according to any one of the first to fourth aspects, wherein the water-repellent layer is a coating film of a fluorine resin.

In the invention of claim 6, the nozzle base material is provided with a nozzle for discharging liquid droplets, and a water repellent layer is formed on the liquid droplet discharge surface side of the nozzle base material. A SiO ₂ layer is formed as a continuous film between the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer, and the water repellent layer has at least one perfluoroalkyl group. And a method of manufacturing a droplet discharge head containing a compound having at least one alkoxysilyl group, wherein the SiO ₂ layer is formed in a thin film by evaporating SiO ₂ in a vacuum, or Si There is provided a method of manufacturing a droplet discharge head, comprising a step of forming a thin film by passing through oxygen plasma in which water is evaporated.

In a seventh aspect of the invention, the nozzle substrate is provided with a nozzle for discharging droplets, and a water repellent layer is formed on the droplet discharge surface side of the nozzle substrate. A SiO ₂ layer is formed as a continuous film between the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer, and the water repellent layer has at least one perfluoroalkyl group. And a method of manufacturing a droplet discharge head containing a compound having at least one alkoxysilyl group, the method comprising the step of forming the SiO ₂ layer by oxide sputtering using SiO ₂ as a target material A method for manufacturing a droplet discharge head is provided.

In the invention of claim 8, the nozzle substrate is provided with a nozzle for discharging droplets, and a water repellent layer is formed on the droplet discharge surface side of the nozzle substrate. A SiO ₂ layer is formed as a continuous film between the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer, and the water repellent layer has at least one perfluoroalkyl group. And a method of manufacturing a droplet discharge head containing a compound having at least one alkoxysilyl group, wherein the SiO ₂ layer is formed by oxidizing Si with a target raw material and oxygen-containing reactive gas. There is provided a method for manufacturing a droplet discharge head, comprising a reactive sputtering step.

In the invention of claim 9, the nozzle substrate is provided with a nozzle for discharging droplets, and a water repellent layer is formed on the droplet discharge surface side of the nozzle substrate. A SiO ₂ layer is formed as a continuous film between the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer, and the water repellent layer has at least one perfluoroalkyl group. And a method of manufacturing a droplet discharge head containing a compound having at least one alkoxysilyl group, wherein the sputtering process and the oxidation process in which the SiO ₂ layer is a target in different zones are used. Provided is a method for manufacturing a droplet discharge head, which includes a step of forming by repeated meta mode sputtering.

  According to a tenth aspect of the present invention, there is provided an image forming apparatus for forming an image on a recording medium by ejecting liquid droplets from a nozzle in accordance with a recording signal, and the liquid according to any one of the first to fifth aspects. An image forming apparatus comprising a droplet discharge head is provided.

  According to the present invention, a highly reliable liquid droplet ejection head that can maintain excellent water repellency over a long period of time even when it is in contact with ink liquid and subjected to friction treatment such as wiping, and the like are provided. An image forming apparatus is provided.

The ink droplet ejection head of the present invention will be specifically described below with reference to the drawings.
The ink droplet ejection head includes a nozzle on a nozzle substrate made of a metal material, and has a configuration in which a water repellent layer is formed on the nozzle substrate on the droplet ejection surface side.
A SiO ₂ layer is formed as a continuous film between the nozzle substrate and the water repellent layer, and the water repellent layer is formed on the SiO ₂ layer.
This water repellent layer contains a compound having at least one perfluoroalkyl group and at least one alkoxysilyl group.

FIG. 1 is an exploded perspective view of the ink droplet ejection head of the present invention.
FIG. 2 shows a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the ink droplet discharge head.
FIG. 3 shows an enlarged view of the main part of FIG.
FIG. 4 is a schematic cross-sectional view of an example along the lateral direction of the liquid chamber of the ink droplet discharge head.
FIG. 5 is a schematic cross-sectional view of another example along the short direction of the liquid chamber of the ink droplet discharge head.

The ink droplet discharge head includes, for example, a flow channel plate 1 formed of a single crystal silicon substrate, a vibration plate 2 bonded to the lower surface of the flow channel plate 1, and a nozzle bonded to the upper surface of the flow channel plate 1. And a base material (nozzle plate) 3.
As shown in FIG. 3, the nozzle 4 that ejects ink droplets communicates with the pressurized liquid chamber 6 via the communication path 5, and further communicates with the liquid chamber 6 via the fluid resistance portion 7. Part 9 is provided.
In the communication part 9, a supply port 10 is provided in the diaphragm 2, and recording liquid (ink) is supplied from a common liquid chamber 8 formed in a frame member 17 described later.

The outer surface of the vibration plate 2 that forms the wall surface of the liquid chamber 6 that stores ink (the surface opposite to the liquid chamber 6) is connected to the vibration plate 2 corresponding to each liquid chamber 6. The upper end portion of the multilayer piezoelectric element 12 as pressure generating means is joined via the portion 11.
The lower end portion of the multilayer piezoelectric element 12 is bonded and fixed to the support substrate 13.
The support substrate 13 may be divided for each row of the piezoelectric elements 12.

As shown in FIG. 3, the piezoelectric element 12 has a configuration in which piezoelectric material layers 14 and internal electrodes 15a and 15b are alternately stacked.
In this case, the ink in the liquid chamber 6 may be pressurized using a displacement in the d33 direction as the piezoelectric direction of the piezoelectric element 12, and the displacement in the d31 direction may be used as the piezoelectric direction of the piezoelectric element 12 in the pressurized liquid chamber 6. It is good also as a structure which pressurizes ink.

The periphery of the flow path plate 1 and the vibration plate 2 is bonded and bonded to a frame member 17 formed by injection molding, for example, epoxy resin or polyphenylene sulfite.
The frame member 17 and the support substrate 13 are fixed to each other by an adhesive or the like (not shown).
The frame member 17 is provided with the common liquid chamber 8 described above, and further, a supply path (communication pipe) for supplying the recording liquid from the outside to the common liquid chamber 8 is provided. Is connected to a recording liquid supply source such as a recording liquid cartridge (not shown).

As shown in FIG. 2, an FPC cable 18 is connected to the piezoelectric element 12 by solder bonding, ACF (anisotropic conductive film) bonding or wire bonding in order to give a drive signal.
A drive circuit (driver IC) 19 for selectively applying a drive waveform to each piezoelectric element 12 is mounted on the FPC cable 18.

As a material for forming the flow path plate 1, for example, a single crystal silicon substrate having a crystal plane orientation (110) is suitable.
By performing anisotropic etching using an alkaline etching solution such as potassium hydroxide aqueous solution (KOH) on this, the communication path 5, the through-hole serving as the pressurized liquid chamber 6, the fluid resistance portion 7, the communication portion 9 and the like are formed. The groove part to comprise can be formed.

The diaphragm 2 is manufactured by an electroforming method (electroforming) using a metal plate such as nickel (Ni).
In the diaphragm 2, a portion corresponding to the liquid chamber 6 is a thin portion that can be easily deformed, and a connecting portion 11 for joining to the piezoelectric element 12 is provided in the center portion.

  In the lateral direction of the liquid chamber (the direction in which the nozzles 4 are arranged), as shown in FIG. 4, a bi-pitch structure in which the piezoelectric elements 12 and the column portions 22 are alternately arranged may be used. As shown in FIG. It is good also as a normal pitch structure which does not provide the support | pillar part 22. FIG.

As shown in FIG. 3, nozzles 4 having a diameter of, for example, 10 to 35 μm are formed in the nozzle base material 3 so as to correspond to the liquid chambers 6, and are joined to the flow path plate 1.
A water repellent layer made of a predetermined silicon resin is provided on the droplet discharge surface (surface in the discharge direction, the surface opposite to the liquid chamber 6) of the nozzle substrate 3.

Next, the nozzle substrate 3 that is a characteristic part of the ink droplet ejection head of the present invention will be described with reference to FIGS.
6A to 6F are partial enlarged cross-sectional views of the nozzle 4 shown in FIGS.

The nozzle base material 3 is formed with an SiO ₂ layer 32 and a water repellent layer 33 as an intermediate layer on the discharge surface side of a metal plate 31 in which nozzle holes that will eventually become the nozzles 4 are formed. The polyimide layer 34 for joining with a flow-path board is formed in the surface on the opposite side.
In addition, although Ni can be applied as a material of the metal plate 31, the present invention is not limited to this.

  As shown in FIG. 6B, the metal plate 31 provided with the nozzle holes shown in FIG. 6A, between the predetermined thermoplastic adhesive to be bonded to the flow path plate 1 and the metal plate 31. A polyimide layer 34 is applied and formed as an intermediate layer that ensures the function of improving adhesiveness.

Next, as shown in FIGS. 6C and 6D, the polyimide resin that has turned back to the nozzle surface side is removed by oxygen plasma irradiation.
Subsequently, as shown in FIG. 6E, the SiO ₂ layer 32 is formed with a thickness of 100 nm on the nozzle surface side, and the water repellent layer 33 is formed with a thickness of 10 nm as shown in FIG. .

Examples of the method for forming the SiO ₂ layer 32 include the following (1) to (4).
(1) SiO ₂ is evaporated in vacuum to form a thin film. Alternatively, a vacuum deposition method in which Si is evaporated and passed through oxygen plasma to form a dielectric on the substrate is applied.
(2) An oxide sputtering method in which a thin film is formed by striking atoms and clusters with Ar plasma or the like using SiO ₂ as a target.
(3) A reactive sputtering method in which a thin film is formed on a substrate while being oxidized with a reactive gas containing oxygen and using Si as a target is applied.
(4) A meta-mode sputtering method in which a sputtering process using Si as a target and an oxidation treatment process are repeated in different zones is applied.

As shown in FIG. 13 above, it is necessary to effectively prevent the entry of hydrolysis components at the interface between the SiO ₂ layer 32 and the metal plate.
The penetration of the hydrolysis component into the interface includes physical penetration and chemical penetration.

First, hydrolysis component in the interface of the SiO ₂ layer 32 and the metal plate so as not to physically penetrate, formed to be a SiO ₂ layer 32 as a continuous film. Here, the continuous film means that the entire formation surface is covered with no defects. Specifically, it is necessary to form at least a film thickness of 20 nm or more.
As shown in FIG. 7, the formation of pinhole holes can be reliably prevented by setting the thickness of the SiO ₂ layer to 20 nm or more.

Next, in order to prevent chemical entry of the hydrolysis component into the interface between the SiO ₂ layer 32 and the metal plate, it is necessary to form a thick Si—O—Si which is a hydrophobic structure in the SiO ₂ layer. It is.
As shown in FIG. 8, by setting the thickness of the SiO ₂ layer to 100 nm or more, air permeability and moisture permeability can be reliably prevented.

That is, when the relationship between the film thickness of the SiO ₂ layer and the penetration of the hydrolysis component into the interface is divided into physical penetration and chemical penetration, it is found that the tendency shown in FIG. 9 is exhibited.

The SiO ₂ layer may form a metal layer as the base layer.
Any of Ta, Al, V, Cr, Zr, Ti, W, Fe, Mo, Mg, Ni, Co, Sn, Zn, Cd, Pd, Pb, Cu, and Ag can be applied to the metal layer. Thereby, the adhesion of the SiO ₂ layer can be enhanced.

Next, the water repellent layer 33 shown in FIG.
The water repellent layer 33 can be formed in the same chamber as the SiO ₂ layer forming chamber. Specifically, first, a lower surface treatment is performed on the surface by vapor-depositing SiO _2. Further, as an ink repellent treatment agent, for example, as shown in the following general formula (1) and general formula (2): The water repellent layer 33 is formed by vapor deposition using a compound having at least one perfluoroalkyl group and at least one alkoxysilyl group in the molecule. For example, by using a modified perfluorooxetane (trade name Optool DSX (manufactured by Daikin Industries, Ltd.), a compound having an alkoxysilane residue at the end of the perfluoropolyether chain, as a fluorine-based ink repellent treatment, wiping durability In addition, ink contact reliability can be secured.
The method of forming the water repellent layer 33 is not limited to vapor deposition, and other coating methods such as dip / spin coating may be used.

_{F {CF (CF 3) -CF} 2 O} n-CF (CF 3) -X-Si (OR) 3 ··· (1)
_{F {CF (CF 3) -CF} 2 O} n-CF (CF 3) -X-Si (OR) 2 R ··· (2)

By forming the water repellent layer 33 using the above-mentioned material, excellent ink repellency is exhibited, and penetration into the interface is effectively prevented via the SiO ₂ layer as the underlayer.

Here, the water repellent treatment material comprising the compounds represented by the general formulas (1) and (2) proceeds in the same manner as the reaction to the SiO ₂ layer as the underlayer, and finally the reaction. It ends when the steric hindrance near the point becomes dense. During this so-called coupling reaction, the reaction point becomes more difficult to approach the terminal OH group of SiO _{2 as} the underlayer due to the perfluoroalkyl groups surrounding it, and as a result, what is SiO _{2 as the} underlayer? Many of the coupling objects are present in a state of being attached to the nozzle surface without being bonded.
These coupled products also serve to prevent water and hydrolysis factor substances from entering the interface between the metal and SiO ₂ .

As a method for forming the water repellent layer 33, for example, as shown in FIG. 10, first, fine irregularities are formed in advance on the surface of the SiO ₂ layer 32 which is the base layer, and the water repellent treatment material is applied thereon. The water repellent layer 33 is formed using the same.
Since the portion of the water repellent layer 33 that protrudes from the surface irregularities of the SiO ₂ layer 32 is removed by wiping performed later, the film thickness of the water repellent layer 33 is reduced to the surface roughness of the SiO ₂ layer 32. If the thickness is not less than (Ra), the surface irregularities of the SiO ₂ layer 32 can be filled with a water repellent film.

Next, the driving method of the ink droplet discharge head described above will be described with reference to FIG.
For example, in the case of driving by a pushing method, a drive pulse voltage of 20 to 50 V is selectively applied to a plurality of piezoelectric elements 12 according to a target image from a predetermined control unit (not shown). The
The piezoelectric element 12 to which the pulse voltage is applied is displaced to deform the vibration plate 2 in the direction of the nozzle plate 3, whereby the volume (volume) of the liquid chamber 6 is changed and the liquid in the liquid chamber 6 is added. The ink droplets are discharged from the nozzles 4 of the nozzle plate 3.

As the ink droplets are ejected, the pressure in the liquid chamber 6 decreases, and a slight negative pressure is generated in the liquid chamber 6 due to the inertia of the ink liquid flow at this time.
Under this state, the application of voltage to the piezoelectric element 12 is turned off, so that the diaphragm 2 returns to the original position and the liquid chamber 6 has the original shape, so that further negative pressure is generated.
Subsequently, the ink liquid supplied from a predetermined ink liquid supply pipe is filled in the liquid chamber 6 and discharged from the nozzle 4 in response to the application of the next drive pulse.

Next, an example of the image forming apparatus including the above-described ink droplet discharge head according to the present invention will be described.
11 is an explanatory plan view of a mechanism portion of the image forming apparatus, and FIG. 12 is an explanatory side view of the overall configuration of the image forming apparatus.

In this image forming apparatus, a carriage 103 is slidably held in a main scanning direction by a guide rod 101 which is a guide member horizontally mounted on left and right side plates (not shown) and a predetermined guide rail. The main scanning motor 104 moves and scans in the direction indicated by the arrow (main scanning direction) via a timing belt 105 stretched between the driving pulley 106A and the driven pulley 106B.
On the carriage 103, for example, four recording heads 107y including the droplet discharge heads of the present invention, which respectively discharge yellow (Y), cyan (C), magenta (M), and black (K) ink droplets, 107c, 107m, and 107k are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  On the other hand, as a paper feeding unit for feeding paper 112 stacked on a paper stacking unit (pressure plate) 111 such as a paper feeding cassette 110, a half-moon roller (separately feeding paper 112 one by one from the paper stacking unit 111) A separation pad 114 made of a material having a large friction coefficient is provided opposite to the sheet feeding roller 113 and the sheet feeding roller 113, and the separation pad 114 is urged toward the sheet feeding roller 113 side.

  In order to convey the sheet 112 fed from the sheet feeding unit below the droplet discharge heads 107k to 107y, a conveyance belt 121 for electrostatically adsorbing and conveying the sheet 112, and a guide from the sheet feeding unit The counter roller 122 for transporting the paper 112 sent via the belt 115 sandwiched between the transport belt 121 and the paper 112 fed substantially vertically upward is turned approximately 90 ° to follow the transport belt 121. For this purpose, a conveying guide 123 and a pressing roller 125 urged toward the conveying belt 121 by a pressing member 124 are provided. In addition, a charging roller 126 that is a charging unit for charging the surface of the conveyance belt 121 is provided.

The conveyance belt 121 that conveys the sheet is an endless belt, is stretched between the conveyance roller 127 and the tension roller 128, and the conveyance roller 127 passes from the sub-scanning motor 131 via the timing belt 132 and the timing roller 133. By rotating, it is configured to circulate in the belt conveyance direction (sub-scanning direction).
A slit disk 134 is attached to the shaft of the transport roller 127, and a sensor 135 that detects the slit of the slit disk 134 is provided. The rotary encoder 136 is configured by the slit disk 134 and the sensor 135. is doing.

  Further, as a paper discharge unit for discharging the paper 112 after recording, a predetermined separation claw for separating the paper 112 from the transport belt 121, a paper discharge roller 152 and a paper discharge roller 153, and a paper 112 to be discharged. And a paper discharge tray 154 for stocking.

Furthermore, a maintenance / recovery mechanism 156 for maintaining and recovering the state of the nozzles of the droplet discharge head is disposed in the non-printing area on one side of the carriage 103 in the scanning direction.
The maintenance / recovery machine 156 discharges the thickened recording liquid, each cap 157 for capping each nozzle face of the droplet discharge head, a wiper blade 158 which is a blade member for wiping the nozzle face. Are provided with a blank discharge receptacle 159 for receiving droplets when performing blank discharge for discharging droplets that do not contribute to recording.
While the carriage 103 is moved in the forward and backward directions, the droplet discharge head is driven according to the image signal, ink droplets are discharged onto the paper 112 to record one line, and after the paper 112 is conveyed by a predetermined amount, the next Records lines. Upon receiving a recording end signal or a signal that the trailing edge of the paper 112 has reached the recording area, the recording operation is finished, and the paper 112 is discharged to a predetermined paper discharge tray.

2 is an exploded perspective view of the ink droplet ejection head of the present invention. FIG. FIG. 2 is a schematic cross-sectional view along the longitudinal direction of the liquid chamber of the ink droplet discharge head. The enlarged view of the principal part of FIG. 2 is shown. FIG. 2 is a schematic cross-sectional view of an example along the lateral direction of the liquid chamber of the ink droplet discharge head. The schematic sectional drawing of another example along the liquid chamber short side direction of an ink droplet discharge head is shown. (A)-(f) The preparation process figure of a nozzle base material is shown. The relationship between the film thickness of the SiO ₂ layer and the number of pinholes is shown. The relationship between the film thickness of the SiO ₂ layer and air / moisture permeability is shown. The relationship between the film thickness of the SiO ₂ layer and the penetration of the hydrolysis component into the surface is shown. The formation state of a water repellent layer and the state after wiping are shown. 1 is a schematic plan view of a mechanism unit of an example of an image forming apparatus including a droplet discharge head of the present invention. 1 is a schematic side view of an overall configuration of an image forming apparatus including a droplet discharge head according to the present invention. It is an explanatory view of a release state of the SiO ₂ layer.

Explanation of symbols

1 Channel plate 2 Vibration plate 3 Nozzle base material (nozzle plate)
DESCRIPTION OF SYMBOLS 4 Nozzle 5 Communication path 6 Pressurized liquid chamber 7 Fluid resistance part 9 Communication part 10 Supply port 11 Connection part 12 Laminated piezoelectric element 13 Support substrate 14 Piezoelectric material layer 15a, 15b Internal electrode 17 Frame member 18 FPC cable 19 Drive circuit ( Driver IC)
31 Metal plate 32 SiO ₂ layer 33 Water repellent layer 34 Polyimide layer 101 Guide rod 103 Carriage 104 Main scanning motor 105 Timing belt 106A Drive pulley 106B Driven pulley 107y, 107c, 107m, 107k Droplet discharge head 110 Paper feed cassette 111 Paper stacking Part (pressure plate)
112 paper 113 half moon roller (feed roller)
114 Separator pad 115 Guide 121 Conveying belt 122 Counter roller 123 Conveying guide 124 Holding member 125 Pressing roller 126 Charging roller 127 Conveying roller 128 Tension roller 131 Sub-scanning motor 132 Timing belt 133 Timing roller 134 Slit disk 135 Sensor 136 Rotary encoder 152 Exhaust Paper roller 153 Paper discharge roller 154 Paper discharge tray 156 Maintenance / recovery mechanism 157 Cap 158 Wiper blade 159 Empty discharge receptacle

Claims (10)

A nozzle substrate made of a metal material is equipped with a nozzle for discharging droplets,
A droplet discharge head in which a water-repellent layer is formed on the droplet discharge surface side of the nozzle substrate,
Between the nozzle substrate and the water repellent layer, a SiO ₂ layer is formed as a continuous film,
The water repellent layer is formed on the SiO ₂ layer,
The water-repellent layer contains a compound having at least one perfluoroalkyl group and at least one alkoxysilyl group. The droplet discharge head according to claim 1, wherein the SiO ₂ layer has an average film thickness of 100 nm or more. 3. The droplet discharge head according to claim 1, wherein a film thickness of the water repellent layer is not less than a surface roughness (Ra) of the SiO ₂ layer. Comprising a metal layer as a base layer of the SiO ₂ layer;
The metal layer is formed of any one of Ta, Al, V, Cr, Zr, Ti, W, Fe, Mo, Mg, Ni, Co, Sn, Zn, Cd, Pd, Pb, Cu, and Ag. The liquid droplet ejection head according to claim 1, wherein the liquid droplet ejection head is provided.   5. The liquid droplet ejection head according to claim 1, wherein the water repellent layer is a coating film. A nozzle substrate made of a metal material is provided with a nozzle that discharges droplets, and a water-repellent layer is formed on a droplet discharge surface side of the nozzle substrate, and the nozzle substrate and the water-repellent layer are Between these layers, a SiO ₂ layer is formed as a continuous film, and the water repellent layer is formed on the SiO ₂ layer. The water repellent layer includes at least one perfluoroalkyl group and at least one perfluoroalkyl group. A method of manufacturing a droplet discharge head containing a compound having two alkoxysilyl groups,
It said SiO ₂ layer, a step of forming a thin film evaporation of SiO ₂ in a vacuum, or a droplet discharge, characterized in that it comprises the step of by passing the oxygen plasma evaporation of Si form a thin film Manufacturing method of the head. A nozzle substrate made of a metal material is provided with a nozzle that discharges droplets, and a water-repellent layer is formed on a droplet discharge surface side of the nozzle substrate, and the nozzle substrate and the water-repellent layer are Between these layers, a SiO ₂ layer is formed as a continuous film, and the water repellent layer is formed on the SiO ₂ layer. The water repellent layer includes at least one perfluoroalkyl group and at least one perfluoroalkyl group. A method of manufacturing a droplet discharge head containing a compound having two alkoxysilyl groups,
A method of manufacturing a droplet discharge head, comprising a step of forming the SiO ₂ layer by oxide sputtering using SiO ₂ as a target material. A nozzle substrate made of a metal material is provided with a nozzle that discharges droplets, and a water-repellent layer is formed on a droplet discharge surface side of the nozzle substrate, and the nozzle substrate and the water-repellent layer are Between these layers, a SiO ₂ layer is formed as a continuous film, and the water repellent layer is formed on the SiO ₂ layer. The water repellent layer includes at least one perfluoroalkyl group and at least one perfluoroalkyl group. A method of manufacturing a droplet discharge head containing a compound having two alkoxysilyl groups,
A method of manufacturing a droplet discharge head, comprising: a reactive sputtering step in which the SiO ₂ layer is formed into a thin film while being oxidized with an oxygen-containing reactive gas using Si as a target material. A nozzle substrate made of a metal material is provided with a nozzle that discharges droplets, and a water-repellent layer is formed on a droplet discharge surface side of the nozzle substrate, and the nozzle substrate and the water-repellent layer are Between these layers, a SiO ₂ layer is formed as a continuous film, and the water repellent layer is formed on the SiO ₂ layer. The water repellent layer includes at least one perfluoroalkyl group and at least one perfluoroalkyl group. A method of manufacturing a droplet discharge head containing a compound having two alkoxysilyl groups,
A method of manufacturing a droplet discharge head, comprising: forming the SiO ₂ layer by a meta mode sputtering method in which a sputtering process using Si as a target and an oxidation treatment process are repeated in different zones. An image forming apparatus that forms an image on a recording medium by ejecting liquid droplets from a nozzle according to a recording signal,
An image forming apparatus comprising the droplet discharge head according to claim 1.

Images