JP2016097604A - Nozzle plate and method of manufacturing the same, and ink discharge head and recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nozzle plate having a water-repellent film with high water repellency and excellent wiping durability.SOLUTION: A fluororesin layer 4, which is a solid at ordinary temperatures and which includes an ultraviolet absorber and a fluororesin having an ether linkage in a skeleton, is provided on a metal nozzle substrate 8. A nozzle hole 1 is formed in the nozzle substrate 8 by punching, and a nozzle hole is formed in the fluororesin layer 4 by excimer laser irradiation.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a nozzle plate and a manufacturing method thereof, an ink discharge head including the nozzle plate, and a recording apparatus including the ink discharge head.

  2. Description of the Related Art Conventionally, as a recording apparatus such as a printer, a facsimile machine, a copying apparatus, a plotter, or a complex machine thereof, for example, an ink ejection recording type recording apparatus having an ink ejection head is known.

  The ink discharge head includes a nozzle plate having a plurality of nozzle holes, and discharges ink as droplets from the plurality of nozzle holes. Of the surfaces of the nozzle plate, the surface characteristics of the ink ejection surface, which is the surface on the side where ink droplets are ejected, greatly affect the ejection stability of the ink droplets. In order to improve the surface characteristics of the ink discharge surface, a water repellent film is formed on the ink discharge surface. Since the formed water-repellent film prevents the ink from adhering to the vicinity of the periphery of the nozzle hole, the ejection stability of the ink droplets is improved.

  A photosensitive resin film is pressed from the ink discharge back surface, which is the surface of the nozzle plate opposite to the side on which the ink droplets are discharged, and a part of the photosensitive resin film is pushed into the nozzle hole. A method is disclosed in which the photosensitive resin film is cured, Teflon (registered trademark) eutectoid plating is performed, and then the photosensitive resin film is removed (see Patent Document 1). However, in this method, since the pressing amount of the photosensitive resin film is adjusted by temperature, it is difficult to accurately control the pressing amount. Further, when the diameter of the nozzle hole is reduced in order to increase the printing resolution, a difficult process is required such that it is difficult to push the photosensitive resin film, and the mass productivity is inferior.

  On the other hand, the ink discharge recording type recording apparatus includes a cleaning unit that wipes and removes ink adhering to the ink discharge surface with a blade.

  Teflon (Registered Trademark) (PTFE), which has been used in the past, has been used in a variety of inks that have increased permeability to recording media to achieve high-speed printing, and the types of ink used in industrial applications. There is a demand for a water-repellent material that has insufficient water repellency and higher water repellency. For this reason, it has been proposed to use perfluoropolyether (PFPE) having higher water repellency as the water repellent material (see Patent Document 2). However, the PFPE is a liquid material at room temperature, and its coating film is very thin. Therefore, the water repellency is quickly reduced by the wiping, and there is a problem in wiping durability.

  An ink jet printer head nozzle plate comprising: a step of bonding a water-repellent resin sheet having a constant thickness to an ink ejection surface of a nozzle plate; and a step of opening a resin sheet at a position corresponding to a nozzle hole. According to the manufacturing method, a nozzle plate manufacturing method has been proposed in which the boundary position between the water repellency and the hydrophilicity in the nozzle hole is uniform and the meniscus position can be made constant (see Patent Document 3). However, even if the PTFE exemplified as the resin sheet is used, it cannot cope with the highly penetrable ink.

  It has also been proposed to use a sheet having a water-repellent film on the surface of a base layer made of a hydrophilic polymer material (see Patent Document 4). However, since the proposed water repellent film is very thin, it has poor wiping durability.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a nozzle plate having a water-repellent film having high water repellency and excellent wiping durability.

Means for solving the problems are as follows. That is,
A nozzle plate having nozzle holes and having a fluororesin layer that is solid at room temperature and includes a fluororesin having an ether bond in a skeleton and an ultraviolet absorber on a metal nozzle substrate.

  According to the present invention, the conventional problems can be solved, and a nozzle plate having a water-repellent film having high water repellency and excellent wiping durability can be provided.

FIG. 1 is an explanatory view showing an ink ejection surface 3 of a nozzle plate 2 which is an example of a nozzle plate for an inkjet printer head according to the present invention. FIG. 2 is a partial cross-sectional view of the nozzle plate 2 passing through the central axis of the nozzle hole 1. FIG. 3 is a cross-sectional view of the punch 20 that passes through the central axis of the punch 20. FIG. 4 is a partial schematic view showing a cross section of the metallic flat plate member 10 before drilling. FIG. 5 is a partial schematic view showing one section of the nozzle substrate 8 obtained by drilling the metal flat plate member 10 of FIG. FIG. 6 is a partial schematic view showing a state in which the fluororesin layer 4 is provided on the nozzle substrate 8 of FIG. FIG. 7 is a partial schematic view showing a state in which the nozzle substrate 8 of FIG. 6 provided with the fluororesin layer 4 is irradiated with an excimer laser. FIG. 8 is an explanatory diagram showing an example of the ink discharge head of the present invention. FIG. 9 is a perspective view of a recording apparatus 101 which is an example of the recording apparatus of the present invention. FIG. 10 is a cross-sectional view of a recording apparatus 101 that is an example of the recording apparatus of the present invention.

(Nozzle plate)
The nozzle plate of the present invention includes a nozzle substrate and a fluororesin layer, and further includes other members as necessary.

<Nozzle substrate>
The nozzle substrate is obtained by punching a metal flat plate member. The metal flat plate member may have, for example, a length of 20 mm to 100 mm, a width of 10 mm to 50 mm, and a thickness of 0.02 mm to 0.1 mm. The material of the metal flat plate member is preferably stainless steel, but other materials such as nickel, nickel alloy, iron alloy, etc. may be used.

<Fluorine resin layer>
The fluororesin layer includes a fluororesin having an ether bond in the skeleton and an ultraviolet absorber. All of the fluororesin layers are solid at room temperature.
In this specification, normal temperature refers to a temperature in the range of 10 ° C to 35 ° C.

-Fluororesin having an ether bond-
The fluororesin having an ether bond includes at least one of perfluoroalkoxyalkane and tetrafluoroethylene perfluorodioxole copolymer.

The perfluoroalkoxyalkane has a molecular structure represented by the following structural formula.

The perfluoroalkoxyalkane has a weight average molecular weight of about several hundred thousand to one million, a viscosity of 10 ⁴ poise to 10 ⁵ poise at 380 ° C., and a melting point of 300 ° C. to 310 ° C. The maximum continuous use temperature is 260 ° C. As the perfluoroalkoxyalkane, those appropriately synthesized may be used, or commercially available products may be used.
As said commercial item, brand name PFA (made by Junkosha) etc. are mentioned, for example.

The tetrafluoroethylene perfluorodioxole copolymer has a molecular structure represented by the following structural formula.
The tetrafluoroethylene perfluorodioxole copolymer is a completely amorphous fluororesin (amorphous fluoropolymer) and is a transparent resin. Since it is soluble in a specific fluorine-based solvent, it can be applied to a thin film on a metal, glass, or silicon substrate. As said tetrafluoroethylene perfluorodioxole copolymer, what was synthesize | combined suitably may be used and a commercial item may be used.
As said commercial item, brand name AF1600 (made by DuPont) etc. are mentioned, for example.

  The nozzle plate of the present invention is a nozzle hole opened on a nozzle substrate by irradiating a fluororesin layer provided on the nozzle substrate with an excimer laser from a surface opposite to the surface on which the fluororesin layer is provided. Is produced by opening a hole corresponding to the above in the fluororesin layer. The center wavelength of the excimer laser is 248 nm.

-UV absorber-
The ultraviolet absorber is not particularly limited as long as it can absorb the center wavelength of the excimer laser, and a known ultraviolet absorber can be used regardless of whether it is organic or inorganic.

  Examples of the organic ultraviolet absorber include aromatic ultraviolet absorbing compounds such as aromatic hydrocarbons, aromatic carboxylic acids and salts thereof, aromatic aldehydes, aromatic alcohols, aromatic amines and salts thereof. Aromatic sulfonic acids and salts thereof, phenols and the like. Among these, aromatic ultraviolet absorbing compounds are particularly preferable.

  Examples of the aromatic ultraviolet absorbing compound include naphthalene, phenanthrene, anthracene, naphthacene, pyrene, perylene, fluorenone, fluoranthene, 9-acetylanthracene, 9-methylanthracene, anthraquinone carboxylic acid, anthracene-9-methanol, biphenyl. Sodium benzoate, phthalic acid, benzaldehyde, benzyl alcohol, phenylethanol, benzenesulfonic acid, 2-naphthalenesulfonic acid, sodium anthraquinone-2-sulfonate, phenol, cresol, 2,4-dihydroxybenzophenone, 2-hydroxy-4 -Methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4 Octadecyloxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4 -Methoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2'-hydroxy-4-chlorobenzophenone, 2 (2'-hydroxy-5-methoxyphenyl) benzotriazole, 2 (2 ' -Hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole, 2 (2'-hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy- 3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazol , Phenyl salicylate, p-octylphenyl salicylate, p-t-butylphenyl salicylate, carboxyphenyl salicylate, strontium salicylate, methyl salicylate, dodecyl salicylate, resorcinol monobenzoate, 2-ethylhexyl-2-cyano-3, 3-diphenylacrylate, And ethyl-2-cyano-3,3-diphenyl acrylate, Ni-bisoctylphenyl sulfide, [2,2′-thiobis (4-tert-octylphenolato)]-n-butylamine-Ni, and the like. These may be used alone or in combination of two or more.

  Examples of the inorganic ultraviolet absorber include titanium oxide (melting point 1640 ° C.), cerium oxide (melting point 1950 ° C.), zinc oxide (melting point 1975 ° C.), tin oxide (melting point 1080 ° C.), iron oxide (melting point 1360 ° C.). Etc. Among these, titanium oxide, cerium oxide, and zinc oxide are preferable.

-Content of UV absorber-
5 mass%-30 mass% are preferable with respect to a fluororesin, and, as for content of the said ultraviolet absorber, 10 mass%-20 mass% are more preferable. If the content of the ultraviolet absorber is 5% by mass or more, the drilling process by the excimer laser becomes easy, and if the content of the ultraviolet absorber is 30% by mass or less, the water repellency and durability, etc. The characteristics of the fluororesin are not impaired.

-Average thickness of fluororesin layer-
The average thickness of the fluororesin layer is preferably 1 μm to 15 μm, and more preferably 1 μm to 10 μm. From the viewpoint of wiping durability, 1 μm or more is sufficient, and from the viewpoint of drilling by the excimer laser, a thinner one is desirable. When the average thickness of the fluororesin layer 4 is in the range of 1 μm to 15 μm, it is preferable from the viewpoint of the wiping durability and from the viewpoint of drilling by the excimer laser. The average thickness can be measured, for example, by a cross-sectional SEM.

-Arithmetic mean roughness (Ra)-
The arithmetic average roughness (Ra) of the fluororesin layer is preferably 0.1 μm or less. When the Ra is 0.1 μm or less, the nozzle surface becomes extremely smooth, ink remaining due to wiping is reduced, and wear resistance is excellent. The arithmetic average roughness (Ra) is defined as follows. In the section of length l, only the reference length is extracted from the roughness curve in the direction of the average line, the X axis is taken in the direction of the average line of the extracted portion, and the Y axis is taken in the direction of the vertical magnification. When the roughness curve is represented by y = f (x), the value obtained by the following equation (1) is represented by micrometers (μm).

<Formula (1)>

(Nozzle plate manufacturing method)
The method for producing a nozzle plate of the present invention includes a step of providing a fluororesin layer on a metal nozzle substrate having a nozzle hole and a hole corresponding to the nozzle hole by irradiating an excimer laser from the other surface. Opening the fluororesin layer.
The fluororesin layer includes a fluororesin and an ultraviolet absorber that are solid at room temperature and have an ether bond in the skeleton. The manufacturing method further includes other steps as necessary.

(Ink ejection head)
The ink discharge head of the present invention includes the nozzle plate of the present invention, a flow path unit, an actuator unit, and a frame, and further includes other units as necessary.

<Flow path unit>
The flow path unit has a plurality of pressure chambers communicating with an ink supply source that supplies ink.

<Actuator unit>
The actuator unit used in the present invention is arranged to change the volume of the pressure chamber. The actuator unit includes an actuator that is energy generating means for discharging ink.
The actuator may be a piezoelectric actuator, a thermal actuator, a shape memory alloy actuator, or an electrostatic actuator. The piezoelectric actuator may be a piezoelectric element. The thermal actuator is an actuator that utilizes a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor. The shape memory alloy actuator is an actuator using a metal phase change due to a temperature change. The electrostatic actuator is an actuator that uses electrostatic force.

<Frame>
The frame used in the present invention is provided to support the flow path unit and the actuator unit.

(Recording device)
The recording apparatus of the present invention is equipped with the ink discharge head of the present invention. The recording device may be any of various recording devices using an ink jet recording method, for example, an ink jet recording printer, a facsimile device, a copying device, or a printer / fax / copier multifunction device.

  Hereinafter, the nozzle plate for an ink jet printer head of the present invention and the manufacturing method thereof will be described with reference to the drawings.

-Nozzle plate for inkjet printer head-
FIG. 1 is an explanatory view showing an ink ejection surface 3 of a nozzle plate 2 which is an example of a nozzle plate for an inkjet printer head according to the present invention. The nozzle plate 2 has a thin plate shape. The nozzle plate 2 is provided with a plurality of nozzle holes 1 in a row.

  FIG. 2 is a partial cross-sectional view of the nozzle plate 2 passing through the central axis of the nozzle hole 1. The nozzle plate 2 has a configuration in which a fluororesin layer 4 having a constant water repellency is provided on the ink ejection surface side 13 of the nozzle substrate 8. The fluororesin layer 4 has a through hole having the same shape as the nozzle hole 1 at a position corresponding to the nozzle hole 1. The metal flat plate member that is the material of the nozzle substrate 8 may be, for example, 20 mm to 100 mm in length, 10 mm to 50 mm in width, and 0.02 mm to 0.1 mm in thickness.

  FIG. 3 is a partial cross-sectional view of the punch 20 that passes through the central axis of the punch 20. The punch 20 is manufactured using a super hard material typified by tungsten carbide, and has a cylindrical front end portion 21 and a conical rear end portion 22. The cylindrical tip portion 21 has a shape that is suitable for opening the nozzle hole 1 from the ink discharge back surface 6 in a metal flat plate member by pressing. The length of the cylindrical tip portion 21 can be set to, for example, 10 μm to 200 μm, and the diameter can be set to, for example, 15 μm to 25 μm, in accordance with the metal flat plate member that opens the nozzle hole 1.

-Manufacturing procedure of nozzle plate for inkjet printer head-
The manufacturing procedure of the nozzle plate for an ink jet printer head of the present invention will be described with reference to FIGS.
FIG. 4 is a partial schematic view showing a cross section of the metallic flat plate member 10 before drilling. The metal flat plate member 10 has, for example, a length of 30 mm, a width of 15 mm, and a thickness of 0.05 mm. In the examples described later, the metal flat plate member 10 is made of stainless steel, but may be made of other materials such as nickel, nickel alloy or iron-based alloy.

  Using the punch 20, the metal flat plate member 10 is punched from the ink discharge back surface 6 side. The cylindrical tip portion 21 of the punch 20 used for drilling can have a length of 10 μm and a diameter of 20 μm, for example. When burrs are generated on the ink discharge surface side 13 of the metal flat plate member 10 by the perforating process, it is preferable to remove the burrs by polishing or chemical etching of the ink discharge surface side 13.

  FIG. 5 is a partial schematic view showing one section of the nozzle substrate 8 obtained by drilling the metal flat plate member 10 of FIG. Nozzle holes 1 are formed in the nozzle substrate 8 by drilling. In one example, the formed nozzle hole 1 has an ink ejection surface side 13 diameter of 20 μm, an ink ejection back surface 6 side diameter of 40 μm, and the cylindrical opening 7 has a height of 10 μm. Although FIG. 5 illustrates one nozzle hole 1, a large number of nozzle holes 1 can be formed at a time by arranging a large number of punches 20 in series. Further, instead of punching with the punch 20, the metal flat plate member 10 may be punched by at least one of electroforming, cutting, laser processing, and electric discharge machining.

  FIG. 6 is a partial schematic view showing a state in which the fluororesin layer 4 is provided on the nozzle substrate 8 of FIG. The fluororesin layer 4 is provided on the ink ejection surface side 13 of the nozzle substrate 8 and has a constant thickness.

  The fluororesin layer 4 contains a fluororesin having water repellency. The fluororesin is particularly a perfluoroalkoxyalkane (trade name PFA, molecular weight 100,000, manufactured by Junko Co., Ltd.) or a tetrafluoroethylene perfluorodioxole copolymer (trade name AF1600, manufactured by DuPont) having an ether bond in the skeleton. preferable.

  The fluororesin layer 4 is preferably formed into a film by adding an ultraviolet absorber that absorbs 248 nm, which is the central wavelength of the excimer laser. If it carries out like this, the drilling process by the below-mentioned excimer laser will become easy.

  5 mass%-30 mass% are preferable with respect to a fluororesin, and, as for content of the said ultraviolet absorber, 10 mass%-20 mass% are more preferable. Moreover, 1 micrometer-15 micrometers are preferable and, as for the average thickness of the fluororesin layer 4, 1 micrometer-10 micrometers are more preferable.

  Further, the fluororesin layer 4 may be joined as a film, and this makes it possible to form a resin layer having a wide range of resin materials and an extremely smooth surface and a uniform thickness. Further, by applying the fluororesin layer 4 as a coating liquid, a nozzle plate can be produced at a low cost by a simple process. By joining the fluororesin layer 4 as a film, or by applying the fluororesin layer 4 as a coating liquid, the arithmetic average roughness (Ra) indicating the surface smoothness of the fluororesin layer 4 becomes 0.1 μm or less, The nozzle surface is extremely smooth. In this way, ink remaining due to wiping is reduced, and wear resistance is excellent.

The fluororesin layer 4 may be provided by adhesion such as thermocompression bonding, and an epoxy adhesive may be used as necessary. Moreover, it is also possible to provide by the spin coat method which spin-coats a coating liquid.
In the examples to be described later, a 1 μm epoxy resin adhesive is applied to the nozzle substrate by an adhesive thin film transfer device, and then the fluororesin layer 4 is brought into close contact and left at 70 ° C. for 1 hour while applying a pressure of 5 kg / cm ^2. And cured.

FIG. 7 is a partial schematic view showing a state in which the nozzle substrate 8 of FIG. 6 provided with the fluororesin layer 4 is irradiated with an excimer laser.
As shown in FIG. 7, the excimer laser is irradiated from the ink discharge back surface 6 side. The excimer laser is also applied to the fluororesin layer 4 through the nozzle holes 1 of the nozzle substrate 8 to open through holes having the same shape as the nozzle holes 1 in the fluororesin layer 4. As a result, the nozzle plate 2 for the ink discharge head shown in FIG. 1 is completed. The boundary between the water repellency and the hydrophilicity of the nozzle plate 2 is on the surface of the nozzle substrate 8 on the ink ejection surface side 13.
When the average thickness of the fluororesin layer 4 is 1 μm to 15 μm, energy during drilling by laser irradiation is reduced and production costs can be suppressed while ensuring durability against wiping.

The ink ejection head provided with the nozzle plate 2 and the nozzle plate 2 of the present invention obtained by the above process uses a fluorine resin layer 4 that is solid at room temperature and has an ether bond in the skeleton on the water repellent surface. Thereby, it has extremely high water repellency compared to other water repellent materials such as PTFE, and also has good water repellency even for inks with high wettability with improved permeability to recording media. Further, of the ink discharge surface 3 and the nozzle hole 1 side surface, the portion from the ink discharge surface 3 to a depth corresponding to the thickness of the fluororesin layer 4 exhibits water repellency. The background of the member 10 is exposed. In general, since a natural oxide film is formed on the metal surface to exhibit hydrophilicity, the exposed portion of the metal flat plate member 10 on the side surface of the nozzle hole 1 is hydrophilic. Accordingly, the nozzle plate 2 is completed in which the position of the side surface of the nozzle hole 1 corresponding to the thickness of the fluororesin layer 4 from the ink discharge surface 3 is the boundary position between water repellency and hydrophilicity. As a result, the meniscus position of the liquid to be discharged is constant, and a head having good discharge performance can be manufactured.
Moreover, since the fluororesin layer 4 is a solid resin at room temperature, it has high wear resistance against wiping and can maintain water repellency over a long period of time.

-Ink ejection head-
Next, an example of the ink discharge head of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram showing an example of the ink discharge head of the present invention.
The flow path unit 31 and the actuator unit 32 are integrally fixed via a frame 33. In the flow path unit 31, the nozzle plate 2, the chamber plate 35, and the vibration plate 36 are stacked, and the pressure chamber 38 is contracted and expanded by expansion and contraction of each piezoelectric vibrator 37 that is a pressure generating unit of the actuator unit 32. It is configured to eject droplets.

A plurality of nozzle holes 1 communicating with the pressure chamber 38 are formed in the nozzle plate 2, and a pressure chamber 38 and a fluid resistance portion 34 are formed in the chamber plate 35.
The vibration plate 36 is provided so as to face the convex portion 42 that contacts the tip of the piezoelectric vibrator 37, the first diaphragm portion 43 that can be elastically deformed, and the pressure chambers 38. In addition, a liquid supply port 45 from a common liquid chamber 41 provided in the frame 33 is formed. Further, a second diaphragm portion 44 similar to the first diaphragm portion 43 described above is also formed in the region facing the common liquid chamber 41. The flow path unit 31 is obtained by joining a stainless steel chamber plate 35, the nozzle plate 2, and the vibration plate 36.

  The vibration plate 36 can be elastically deformed by the displacement of the piezoelectric vibrator 37 on the rolled metal plate 48 and has a corrosion resistance against ink, for example, a polymer film such as polyimide (PI) or polyphenylene sulfide (PPS) resin. 49 is laminated. A positioning hole made of a through hole is drilled at an important point, and a region where the first diaphragm portion 43 and the second diaphragm portion 44 are to be formed is etched to form the convex portion 42 by the rolled metal plate 48. ing.

  The nozzle hole 1 has a diameter of 10 μm to 30 μm corresponding to the pressure chamber 38. Further, a water repellent film is formed on the ink ejection surface of the nozzle plate 2 in order to ensure water repellency with the liquid. Then, piezoelectric vibrators 37 as pressure generating means are joined to the outer side of the diaphragm 36 (on the side opposite to the pressure chamber 38) corresponding to each pressure chamber 38. These diaphragm 36 and pressure vibrator 37 constitute a piezoelectric actuator that deforms the first diaphragm portion 43 that is a movable part of the diaphragm 36.

In the ink discharge head, the piezoelectric vibrator 37 is formed without being divided by groove processing (slit processing). Further, an FPC cable 50 for giving a driving waveform to each piezoelectric vibrator 37 is connected to one end face of the piezoelectric vibrator 37.
Note that the liquid in the pressure chamber 38 may be pressurized using a displacement in the d33 direction (a direction perpendicular to the electrode surface) as the piezoelectric direction of the piezoelectric vibrator 37. Alternatively, the liquid in the pressure chamber may be pressurized using a displacement in the d31 direction (a direction perpendicular to the electrode surface) as the piezoelectric direction of the piezoelectric vibrator 37. In the present embodiment, a configuration using displacement in the d33 direction is adopted.

  The base member 51 is preferably formed of a metal material. If the material (material) of the base member 51 is a metal, heat storage due to self-heating of the piezoelectric vibrator 37 can be prevented. The piezoelectric vibrator 37 and the base member 51 are bonded and bonded with an adhesive. However, when the number of channels increases, the temperature rises to near 100 ° C. due to self-heating of the piezoelectric vibrator 37 and the bonding strength is significantly reduced. Become. In addition, the temperature inside the head increases due to self-heating, and the liquid temperature rises. However, when the temperature of the liquid rises, the liquid viscosity decreases and the ejection characteristics are greatly affected. Therefore, by forming the base member 51 from a metal material and preventing heat storage due to self-heating of the piezoelectric vibrator 37, it is possible to prevent deterioration in jetting characteristics due to a decrease in bonding strength and a decrease in liquid viscosity.

The FPC cable 50 is equipped with a plurality of driver ICs 52 for applying drive waveforms (electric signals) for driving each channel (corresponding to each pressure chamber 38).
Further, a frame 33 is bonded around the diaphragm 36 with an adhesive. In the frame 33, a common liquid chamber 41 for supplying liquid from the outside to the pressure chamber 38 is formed so as to be disposed on the opposite side of the driver IC 52 and at least the base member 51. The common liquid chamber 41 communicates with the fluid resistance portion 34 and the pressure chamber 38 via the liquid supply port 45 of the vibration plate 36.
In the common liquid chamber 41, a damper chamber 53 is formed by the second diaphragm portion 44, and a pressure wave generated in the common liquid chamber 41 by liquid discharge is attenuated to stabilize liquid discharge.
The piezoelectric vibrator 37 has a configuration in which piezoelectric layers (piezoelectric material layers) 54, internal electrodes 55A, and internal electrodes 55B are alternately stacked. Further, the piezoelectric vibrator 37 is formed with a plurality of piezoelectric vibrators by slitting (grooving) and providing grooves with the common-side external electrode 56 and the individual-side external electrode 57 provided on both end faces. Forming.

  In the ink ejection head configured as described above, by selectively applying a drive pulse voltage of 20 V to 50 V to the drive unit of the piezoelectric vibrator 37, the drive unit to which the pulse voltage is applied extends in the stacking direction. The diaphragm is deformed in the nozzle direction. As a result, the liquid in the pressure chamber 38 is pressurized by the volume or volume change of the pressure chamber 38, and ink droplets are ejected (jetted) from the nozzle hole 1.

-Recording device-
The nozzle plate 2 of the present invention can be suitably used for various recording apparatuses using an ink jet recording method, such as an ink jet recording printer, a facsimile apparatus, a copying apparatus, and a printer / fax / copier multifunction machine.

Hereinafter, an ink jet recording apparatus used also in examples described later will be described with reference to FIGS. FIG. 9 is a perspective view of a recording apparatus 101 which is an example of the recording apparatus of the present invention. FIG. 10 is a cross-sectional view of a recording apparatus 101 that is an example of the recording apparatus of the present invention.
A recording apparatus 101 illustrated in FIG. 9 includes a paper feed tray 102, a paper discharge tray 103, and an ink cartridge loading unit 104. The paper feed tray 102 is mounted on the recording apparatus 101 and loaded with paper. A paper discharge tray 103 is mounted on the recording apparatus 101 and stocks paper on which an image is recorded (formed). On the upper surface of the ink cartridge loading unit 104, an operation unit 105 such as operation keys and a display is arranged. The ink cartridge loading unit 104 has a front cover 115 that can be opened and closed for attaching and detaching the ink cartridge 200. Reference numeral 111 denotes an upper cover, and reference numeral 112 denotes a front surface of the front cover.

  In the recording apparatus 101, as shown in FIG. 10, a carriage 133 is slidably held in the main scanning direction by a guide rod 131 and a stay 132, which are guide members horizontally mounted on left and right side plates (not shown). Then, the scanning is moved by a main scanning motor (not shown).

  A plurality of ink ejection openings of the recording head 134 are arranged in the carriage 133 in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward. The recording head 134 includes four inkjet recording heads that eject ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk).

  As the ink jet recording head constituting the recording head 134, a head provided with a piezoelectric actuator, a thermal actuator, a shape memory alloy actuator, an electrostatic actuator or the like as energy generating means for discharging ink can be used. The piezoelectric actuator may be a piezoelectric element. A thermal actuator is an actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor. The shape memory alloy actuator is an actuator that uses a metal phase change due to a temperature change. An electrostatic actuator is an actuator that uses electrostatic force.

  In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. The sub tank 135 is supplied with ink according to the ink set of the present invention from the ink cartridge 200 of the present invention loaded in the ink cartridge loading section 104 via an ink supply tube (not shown) and is replenished.

  On the other hand, a sheet feeding roller 143 (half moon roller) and a separation pad 144 are provided as a sheet feeding unit for feeding sheets 142 stacked on a sheet stacking unit (pressure plate) 141 of the sheet feeding tray 102. The paper feed roller 143 separates and feeds the paper 142 from the paper stacking unit 141 one by one. The separation pad 144 is provided to face the paper feed roller 143 and is made of a material having a large friction coefficient. The separation pad 144 is biased toward the paper feed roller 143 side.

  The conveyance unit for conveying the sheet 142 fed from the sheet feeding unit below the recording head 134 includes a conveyance belt 151, a counter roller 152, a conveyance guide 153, a pressing member 154, and a tip pressurization. A roller 155. The conveyance belt 151 conveys the sheet 142 by electrostatic adsorption. The counter roller 152 conveys the sheet 142 sent from the sheet feeding unit via the guide 145 with the conveyance belt 151 interposed therebetween. The conveyance guide 153 changes the direction of the sheet 142 fed substantially vertically upward by approximately 90 ° and imitates the sheet 142 on the conveyance belt 151. The pressing member 154 biases the tip pressing roller 155 toward the conveying belt 151. In addition, a charging roller 156 that is a charging unit for charging the surface of the conveyance belt 151 is provided.

  The conveyance belt 151 is an endless belt, is stretched between the conveyance roller 157 and the tension roller 158, and can circulate in the belt conveyance direction. The surface layer of the conveyance belt 151 is a sheet adsorbing surface formed of, for example, a resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, a copolymer of tetrafluoroethylene and ethylene (ETFE). The back layer of the conveyor belt 151 has a medium resistance layer and a ground layer that are made of the same material as the surface layer and perform resistance control with carbon. On the back side of the conveyance belt 151, a guide member 161 is arranged corresponding to a printing area by the recording head 134. Note that a separation claw 171, a paper discharge roller 172, and a paper discharge roller 173 are provided as a paper discharge unit for discharging the paper 142 recorded by the recording head 134. The separation claw 171 separates the paper 142 from the transport belt 151. A paper discharge tray 103 is disposed below the paper discharge roller 172.

  A double-sided paper feeding unit 181 is detachably attached to the back surface of the recording apparatus 101. The double-sided paper feeding unit 181 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 152 and the transport belt 151. A manual paper feed unit 182 is provided on the upper surface of the duplex paper feed unit 181.

  In this ink jet recording apparatus, the paper 142 is separated and fed one by one from the paper feed unit, and the paper 142 fed substantially vertically upward is guided by the guide 145 and between the transport belt 151 and the counter roller 152. It is sandwiched and conveyed. Further, the leading end is guided by the conveying guide 153 and pressed against the conveying belt 151 by the leading end pressure roller 155, and the conveying direction is changed by approximately 90 °.

  At this time, the conveyance roller 157 is charged by the charging roller 156, and the sheet 142 is electrostatically attracted to the conveyance belt 151 and conveyed. Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133, ink droplets are ejected onto the stopped sheet 142 to record one line, and after the sheet 142 is conveyed by a predetermined amount. Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.

  When the ink remaining amount near end in the sub tank 135 is detected, a required amount of ink is supplied from the ink cartridge 200 to the sub tank 135.

  In this ink jet recording apparatus, when the ink in the ink cartridge 200 is used up, the casing of the ink cartridge 200 can be disassembled and only the ink bag inside can be replaced. Further, the ink cartridge 200 can supply ink stably even when the ink cartridge 200 is installed vertically and has a front loading configuration. Therefore, when the upper side of the recording apparatus 101 is closed, for example, even when the recording apparatus 101 is stored in a rack or an object is placed on the upper surface of the recording apparatus 101, the ink cartridge 200 is replaced. Can be easily performed.

  Here, an example is described in which the present invention is applied to a serial (shuttle type) ink jet recording apparatus that is scanned by a carriage, but the present invention can be similarly applied to a line type ink jet recording apparatus having a line type head.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example 1>
The metal flat plate member 10 made of SUS316L having a length of 30 mm, a width of 15 mm, and a thickness of 0.05 mm was punched by the punch 20 shown in FIG. The cylindrical tip portion 21 of the punch 20 used for drilling had a length of 10 μm and a diameter of 20 μm. The burrs generated on the ink ejection surface side 13 were removed by polishing.
By the above process, as shown in FIG. 5, 384 nozzle holes 1 having a diameter of 20 μm on the ink discharge surface side 13, a diameter of 40 μm on the ink discharge back surface 6 side, and a height of the cylindrical opening 7 of 10 μm are formed. did. In this way, a nozzle substrate 8 having 384 nozzle holes 1 was obtained.
On this nozzle substrate 8, a coating solution in which 10 mass% of an ultraviolet absorber was added to a tetrafluoroethylene perfluorodioxole copolymer was spin-coated to form a fluororesin layer 4. As the tetrafluoroethylene perfluorodioxole copolymer, a 6% by mass solution of Teflon (registered trademark) AF (AF1600; manufactured by DuPont) (solvent: Bertrell Souplion; manufactured by DuPont) was used. As the ultraviolet absorber, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole (JF-79, Johoku Chemical Co., Ltd.) was used. The average thickness of the fluororesin layer 4 was 7 μm, and the arithmetic average roughness (Ra) of the surface was 0.1 μm.

  The fluororesin layer 4 provided on the nozzle substrate 8 is irradiated with an excimer laser (wavelength 248 nm) using KrF gas from the ink discharge back surface 6 side of the nozzle substrate 8 to form nozzle holes in the fluororesin layer 4. did. Thus, the nozzle plate 2 of Example 1 having the configuration shown in Table 1 was obtained.

<Example 2>
In Example 1, instead of spin-coating a solution of Teflon (registered trademark) AF added with 10% by mass of an ultraviolet absorber, a perfluoroalkoxyalkane resin added with 10% by mass of the ultraviolet absorber was formed into a film having a thickness of 15 μm. The object was bonded onto the nozzle substrate 8. A nozzle plate of Example 2 having the configuration shown in Table 1 was produced in the same manner as Example 1 except that the fluororesin layer 4 was formed in this way.
As the ultraviolet absorber, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole (JF-79, Johoku Chemical Co., Ltd.) was used. As the perfluoroalkoxyalkane resin, trade name PFA, molecular weight 100,000, manufactured by Junkosha Co., Ltd. was used. The average thickness of the fluororesin layer 4 was 15 μm, and the arithmetic average roughness (Ra) of the surface was 0.1 μm.

<Comparative Example 1>
In Example 2, when the fluororesin layer is provided, the configuration shown in Table 1 is the same as that of Example 2 except that PTFE added with 10% by mass of an ultraviolet absorber is used to form a film having a thickness of 20 μm. A nozzle plate of Comparative Example 1 was obtained. As the ultraviolet absorber, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole (JF-79, Johoku Chemical Co., Ltd.) was used.

<Comparative Example 2>
In Example 1, instead of forming a fluororesin layer 4 by spin-coating a solution of Teflon (registered trademark) AF to which 10% by mass of an ultraviolet absorber was added, OPTOOL DSX (manufactured by Daikin Industries), which is PFPE, was used. A film was formed. Except this point, the nozzle plate of the comparative example 2 which has the structure shown in Table 1 similarly to Example 1 was produced. The film formation of the OPTOOL DSX is performed by depressurizing the OPTOOL DSX stock solution to about 10 ⁻¹ Pa with a rotary pump, gradually elevating the temperature from room temperature to about 450 ° C., and depositing the OPTOOL DSX at about 70 ° C. It was carried out by applying a heat drying treatment for 10 minutes.

<Evaluation>
As an ink jet printer, IPSiO G515 manufactured by Ricoh Co., Ltd. was used, and the nozzle plates of Examples and Comparative Examples were mounted and used for evaluation.
Ricoh Co., Ltd. GX Cartridge Black GC21K, which is a highly penetrating ink, is installed as the ink, and the initial image quality, the image quality after 10,000 to 30,000 times of wiping, and the ink adhesion state on the nozzle surface Were visually observed. The results are shown in Table 1. The image quality was evaluated by visually observing the printed nozzle check pattern. Since the number of wipings until the ink jet printer reaches the end of its life is usually less than 10,000 times, if the wiping is performed 10,000 times and the evaluation result is ◯, there is no problem in actual use.

  As is apparent from Table 1, in Examples 1 and 2, the ink discharge state was good and no problem image quality was obtained even after 30,000 times of wiping, whereas in Comparative Example 1, the initial value was from the initial stage. There was ink sticking to the nozzle surface, resulting in discharge bending. In Comparative Example 2, although the ink discharge state was good in the initial stage, discharge bending occurred after wiping 10,000 times.

<Examples 3 to 5>
Using Teflon (registered trademark) AF used in Example 1, the film thickness was changed as shown in Table 2 to produce a fluororesin layer 4 in which the average thickness and the arithmetic average roughness (Ra) of the surface were changed. Nozzle plates 2 of Examples 3 to 5 were obtained. These were mounted on the head, and the image quality and the ink adhesion state on the nozzle surface were examined in the same manner as in Example 1. The evaluation results are shown in Table 2.

  In Example 3, the average thickness of the fluororesin layer 4 was 1 μm, but there was no problem even after 30,000 times of wiping. In Example 4, when the average thickness of the fluororesin layer 4 was further reduced to 0.5 μm, although there was no problem in image quality after 10,000 times of wiping, some ink adhesion was observed on the nozzle surface, and after 30,000 times of wiping. The ink was bent and the ink adhered. The number of wipings until the printer reaches the end of its life is usually less than 10,000, so there is no problem with the durability of the nozzle plate. However, considering the robustness such as drying of the nozzle surface and adhesion of foreign matter, the durability is up to 30,000 times. Sexuality may be desired. From this, it was found that the average thickness of the fluororesin layer 4 is preferably 1 μm or more. Even if the fluororesin layer 4 is thick, there is no problem in ejection performance, but considering the perforation efficiency by excimer laser, it is economically desirable that the average thickness of the fluororesin layer 4 be 15 μm or less.

  In Example 5 as well, when the image quality test was performed in the same manner, there was no problem in the image quality, but slight ink adhesion was observed on the nozzle surface from the beginning. Further, after wiping 10,000 times, discharge bending occurred, and the amount of ink adhering to the nozzle surface increased.

Aspects of the present invention are as follows, for example.
<1> A nozzle plate having nozzle holes and having a fluororesin layer that is solid at room temperature and includes a fluororesin having an ether bond in a skeleton and an ultraviolet absorber on a metal nozzle substrate. .
<2> A metal nozzle substrate with a nozzle hole is provided with a fluororesin layer that is solid at room temperature containing a fluororesin having an ether bond in its skeleton and an ultraviolet absorber, and an excimer laser is irradiated from the other surface. A nozzle plate manufactured by opening a hole corresponding to the nozzle hole in the fluororesin layer.
<3> The nozzle plate according to any one of <1> to <2>, wherein the fluororesin having an ether bond includes at least one of perfluoroalkoxyalkane and tetrafluoroethylene perfluorodioxole copolymer. is there.
<4> The nozzle plate according to any one of <1> to <3>, wherein the fluororesin layer is formed into a film and then joined to a metal nozzle substrate.
<5> The nozzle plate according to any one of <1> to <3>, wherein the fluororesin layer is formed by coating a metal nozzle substrate as a coating liquid.
<6> The nozzle plate according to any one of <1> to <5>, wherein the fluororesin layer has an average thickness of 1 μm to 15 μm.
<7> The nozzle plate according to any one of <1> to <6>, wherein an arithmetic average roughness (Ra) of the fluororesin layer is 0.1 μm or less.
<8> The method for producing a nozzle plate according to any one of <1> to <7>,
A step of providing a fluororesin layer containing a fluororesin and an ultraviolet absorber, which is solid at room temperature, having an ether bond in the skeleton, on a metal nozzle substrate having a nozzle hole, and irradiating an excimer laser from the other side A method for producing a nozzle plate, comprising the step of opening a hole corresponding to a nozzle hole in the fluororesin layer.
<9> A flow path unit having a nozzle plate that ejects ink, and a plurality of pressure chambers that communicate with an ink supply source that supplies ink, and an actuator unit that is arranged to change the volume of the pressure chamber; In an ink ejection head having the flow path unit and a frame that supports the actuator unit,
The nozzle plate is an ink discharge head according to any one of <1> to <7>.
<10> A recording apparatus comprising the ink discharge head according to <9>.

DESCRIPTION OF SYMBOLS 1 Nozzle hole 2 Nozzle plate 3 Ink discharge surface 4 Fluororesin layer 8 Nozzle substrate 10 Metal flat plate member 13 Ink discharge surface side 31 Channel unit 32 Actuator unit 33 Frame 101 Recording device

JP-A-7-125220 Japanese Patent Laid-Open No. 2003-19803 Japanese Patent Laid-Open No. 10-305584 JP 2007-331346 A Japanese Patent No. 5471646

Claims (10)

  A nozzle plate having a nozzle hole, which has a fluororesin layer that is solid at room temperature and includes a fluororesin having an ether bond in a skeleton and an ultraviolet absorber on a metal nozzle substrate.   A nozzle substrate made of metal having a nozzle hole is provided with a fluororesin layer that is solid at room temperature and includes a fluororesin having an ether bond in the skeleton and an ultraviolet absorber, and the nozzle hole is irradiated with an excimer laser from the other surface. A nozzle plate manufactured by opening a hole corresponding to the above in the fluororesin layer.   The nozzle plate according to claim 1, wherein the fluororesin having an ether bond includes at least one of a perfluoroalkoxyalkane and a tetrafluoroethylene perfluorodioxole copolymer.   The nozzle plate according to claim 1, wherein the fluororesin layer is formed into a film and then joined to a metal nozzle substrate.   The nozzle plate according to any one of claims 1 to 3, wherein the fluororesin layer is formed by coating a metal nozzle substrate as a coating liquid.   The nozzle plate according to claim 1, wherein the fluororesin layer has an average thickness of 1 μm to 15 μm.   The nozzle plate according to claim 1, wherein the arithmetic average roughness (Ra) of the fluororesin layer is 0.1 μm or less. A method for manufacturing a nozzle plate according to any one of claims 1 to 7,
A step of providing a fluororesin layer containing a fluororesin and an ultraviolet absorber, which is solid at room temperature, having an ether bond in the skeleton, on a metal nozzle substrate having a nozzle hole, and irradiating an excimer laser from the other side The manufacturing method of a nozzle plate characterized by including the process of opening the hole corresponding to a nozzle hole in the said fluororesin layer. A flow path unit having a nozzle plate for discharging ink; a plurality of pressure chambers communicating with an ink supply source for supplying ink; an actuator unit arranged to change the volume of the pressure chamber; and the flow path In an ink ejection head having a unit and a frame that supports the actuator unit,
An ink discharge head according to claim 1, wherein the nozzle plate is a nozzle plate according to claim 1.   A recording apparatus comprising the ink discharge head according to claim 9.