JP2008230043A - Method of manufacturing ink-jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an orifice plate which has an improved water-repellent performance and a nozzle processed with high precision in an ink-jet head. <P>SOLUTION: For the ink-jet head, the orifice plate is made by the way of making the die of the nozzle with a photolithography and continuously making a film for plate base material and water-repellent film by a gas deposition method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an orifice plate of an inkjet head in an inkjet recording apparatus that forms and records an image on a recording medium by ejecting and flying ink droplets.

  In recent years, ink jet recording apparatuses have been widely used as recording and printing methods for computers and the like due to features such as low noise and high speed recording.

  As an ink jet head of an ink jet recording apparatus, an orifice plate is used for controlling an ink ejection amount and a landing position on a recording medium in order to eject and fly ink droplets with high accuracy.

The orifice plate is formed with a discharge port having a diameter of 20 to 50 μm, and the outer surface is subjected to water repellent treatment. By performing the water repellent treatment, it is possible to prevent ink droplets from being collected around the ejection port during ink ejection, and the ejection stability is improved.
When ink pools actually occur around the ejection port, ink droplets are affected by the liquid pool around the ejection port when ejecting and flying from the ejection port, the flight direction is disturbed, and the desired position when landing As a result, accurate image formation becomes impossible. Further, the ink pool becomes large, and when ink is accumulated on the entire surface around the ejection port, ejection becomes impossible.

  Actually, in order to solve these problems, water repellent treatment is performed using various materials on the outer surface of the orifice plate.

  Specifically, a method for forming a water repellent layer by treating the outer surface of an orifice plate with silicone oil, gum arabic or the like has been disclosed in Japanese Utility Model Publication No. 48-36188. Japanese Laid-Open Patent Publication No. 55-65564 discloses a method of applying a silicon water repellent and a fluorine water repellent.

  However, these methods have poor adhesion to substrates such as glass, metal, and resin forming the ink jet head, are not durable, and have insufficient effects.

  Japanese Patent Application Laid-Open No. 56-89569 has an example in which the periphery of the discharge port is formed with a fluoroalkylalkoxysilane to form a water-repellent layer. However, the discharge port needs to be processed under high temperature and high pH conditions. There was a risk of damaging the substrate.

  JP-A-4-339656 also has a method of forming a water-repellent layer by performing eutectoid plating with a fluorine-based polymer material such as polytetrafluoroethylene and a metal such as nickel using electrolytic plating. The water repellency may vary depending on the management of the plating solution, the control of the plating conditions, and the heat treatment process after plating.

  As described above, the outer surface of the orifice plate is subjected to water repellency treatment with various materials to stabilize the discharge. As a method of forming a thin film exhibiting water repellency, an organic material is dissolved into a spin. A coating method, dipping or plating method is used.

  In the processing of the nozzle, there are a method of pressing a stainless steel substrate, a method of processing a resin material with a laser, and the like.

In press processing, burrs are generated during processing, and removal by polishing or the like is necessary. In laser processing, it is difficult to control the shape of all nozzles to be the same because the resin is dissolved by the laser to process holes.
Japanese Utility Model Publication No. 48-36188 JP 55-65564 A JP-A-56-89569 JP-A-4-339656 Japanese Patent Registration No. 2524622 Japanese Patent Registration No. 1595398 Japanese Patent Registration No. 2632409 Japanese Patent No. 2596434 Japanese Patent Laid-Open No. 3-93606 JP-A-8-230181 Japanese Patent Laid-Open No. 8-267763 Vacuum Handbook, p289, Nippon Vacuum Co., Ltd.

  However, recently, in the printing of photographs and images for which needs are increasing, there is a need for higher density and high speed driving of inkjet head nozzles, high color development ink, weather resistant ink, and the like. In addition, when the inkjet technology is developed for industrial use, there is a need to deal with special inks.

  In order to meet such technical needs, in the orifice plate, it is desired to improve the water repellency of the outer surface and to increase the accuracy of the nozzle.

  Actually, the orifice plate that has been used so far has not achieved performance that satisfies both the water-repellent performance and the nozzle processed with high precision.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and for the purpose thereof, to provide an orifice plate for an inkjet head having improved water repellency and having a nozzle with a dimension processed with high accuracy. It is.

  In order to solve the above problems, in the present invention, in the production of an orifice plate of an inkjet head, a nozzle mold is produced with high accuracy by photolithography, and the substrate and the water repellent layer of the orifice plate are continuously formed by a gas deposition method. A method for manufacturing an orifice plate of an ink jet head, characterized in that a film is formed on the substrate.

  When creating a resin nozzle mold by photolithography, a resin such as polymethyl methacrylate (PMMA) with photosensitivity is applied to the substrate, exposed to UV light or synchrotron light through a mask, and developed. Thus, a desired high aspect ratio nozzle mold is obtained.

  Synchrotron light is continuous spectrum light including infrared, visible, vacuum ultraviolet, and X-rays, and has an order of magnitude higher brightness than conventional radiation sources and sharp directivity comparable to laser light. In recent years, in micromachine technology development, synchrotron light has been used to process fine parts typified by the LIGA process, and fine structures with a very large aspect ratio can be processed with high precision.

  In the gas deposition method, water, a water repellent material such as metal, oxide, and fluoride can be directly formed into a film, and durability can be improved and high water repellent performance can be achieved.

  The gas deposition method will be briefly described.

  The gas deposition method includes an evaporation method in which a material is evaporated by an ultrafine particle forming method and an aerosol method.

  For example, in the evaporation method, a metal is evaporated in a vacuum chamber, the evaporated atoms collide with an inert gas introduced into the chamber, and rapidly cooled, and the evaporated atoms are combined to form fine particles. The size of the ultrafine particles thus formed varies depending on the amount and type of gas introduced, but generally has a diameter of several nm to several μm.

  Furthermore, the ultrafine particles generated in this way are sucked out and formed into a film made of the ultrafine particles.

The gas deposition method is composed of an ultrafine particle generation chamber, a film formation chamber, a transfer tube, etc., and in the ultrafine particle generation chamber, the material is heated with an arc, resistance heating, high frequency induction heating, laser, etc. It melts and evaporates and collides with an inert gas, and the generated metal ultrafine particles are guided to the film formation chamber through the transfer tube due to the pressure difference between the ultrafine particle generation chamber and the film formation chamber, and from the nozzle connected to the end of the transfer tube This is a dry film forming method in which a pattern is directly drawn by high-speed spraying. (Patent Publication 2524622, Patent 1595398, Patent 2632409, Patent 2596434)
The definition of ultrafine particles is defined as fine particles that cannot be seen with an optical microscope, that is, fine particles of 1 μm or less. (Vacuum Handbook, p289 (Nippon Vacuum Co., Ltd.)
In addition, in the gas deposition method, film formation using fine particles of an oxide ceramic material in addition to a metal material (Japanese Patent Laid-Open No. 3-93606) and piezoelectric ceramic element film formation (Japanese Patent Laid-Open No. 8-230181, Japanese Patent Laid-Open No. 8-267763) has been proposed.

  In the aerosol method, a container containing ultrafine particles is vibrated into an aerosol, and this aerosol is transported as helium or oxygen gas as a carrier gas, guided to a film formation chamber, and from a nozzle connected to the end of the transport pipe. A film is formed by drawing at a high speed.

(Function)
In the orifice plate of the inkjet head as described above, nozzle mold production by photolithography and continuous deposition of the plate base material and water repellent film by the gas deposition method ensure high precision part shape and water repellent performance on the outer surface. It becomes possible to improve and to stably eject and fly ink droplets.

As described above, according to the present invention, in the orifice plate of an ink jet head, a high-precision part shape and a water-repellent film can be formed with high accuracy by forming a nozzle mold by photolithography and continuously forming a plate substrate and a water-repellent film by a gas deposition method. The water repellency of the outer surface can be improved.
The orifice plate of the inkjet head manufactured as described above exhibits sufficient performance with regard to higher printing speed and ejection stability required in the future, for high-speed printing of photographs and images and industrial applications. Can be deployed.

  The present invention relates to an orifice plate of an ink jet head of an ink jet recording apparatus, and a method of ejecting and flying ink droplets using thermal energy, or a method of ejecting and flying ink droplets by volume change using a piezoelectric element. The embodiment of the present invention is applicable as long as ink droplets are ejected and ejected from the ejection port of the orifice plate.

  In the present invention, since the problem of the portion including the orifice plate of the inkjet head is solved, only the portion including the orifice plate will be described in detail.

  FIG. 1 is a configuration diagram of a gas deposition apparatus according to an embodiment of the present invention.

  FIG. 2 is a process flow according to the embodiment of the present invention.

  FIG. 3 is a cross-sectional view of the orifice plate during the process according to the embodiment of the present invention.

The orifice plate was produced according to the process flow shown in FIG.
As a nozzle mold production substrate, a stainless steel plate (150 × 150 × 1.5 mm) was lifted and washed in warm pure water and then isopropyl alcohol (IPA) vapor, followed by UV cleaning for 3 minutes.

  As the mold production substrate, glass may be used in addition to the stainless steel plate.

  The resist material was prepared by adding a solvent to an acrylic copolymer having the following composition.

  The acrylic copolymer has the following monomer composition.

N-methylolacrylamide 20 parts by weight
N, N-dimethylaminoethyl methacrylate 10 parts by weight Methyl methacrylate 25 parts by weight 2-hydroxyethyl methacrylate 40 parts by weight Acrylic acid 5 parts by weight The following solvent was added to 20 parts by weight of the acrylic copolymer to prepare a coating solution.

Ethylene glycol monoethyl ether 15 parts by weight Ethylene glycol 20 parts by weight Isopropyl alcohol 2 parts by weight Pure water 43 parts by weight The resist material was applied by spin coating to a film thickness of 75 μm.

  Then, it dried for 3 minutes on a 50 degreeC hotplate, and exposed the ultraviolet-ray through the mask.

  Next, development was performed to produce a nozzle mold on a stainless steel plate.

  This mold substrate was placed on the drawing stage in the film forming chamber of the gas deposition apparatus shown in FIG. As the ultrafine particle generation chamber, two chambers for metal and water repellent material were provided. As the metal fine particle generation chamber, nickel material was heated by arc discharge to produce ultrafine nickel particles. When the ultrafine particles of nickel produced at this time were observed with a scanning electron microscope (SEM), the particle size was about 50 nm. In the production of nickel ultrafine particles, high frequency induction heating or resistance heating may be used. In addition, titanium, gold, silver, and copper may be used as the metal fine particles.

  When the particle size was observed with a scanning electron microscope (SEM) using PTFE (trade name: Lubron (registered trademark) L5-F) manufactured by Daikin Industries, Ltd. as the fine particles of the water repellent material, it was about 0.2 μm. This was put into a container (aerosol formation chamber) and shaken to make an aerosol.

  First, ultrafine nickel particles were transported on a nozzle-type substrate under the conditions shown in Table 1, and the ultrafine nickel particles were ejected from a 1 mm diameter nozzle attached to the tip of the transport tube to form a 70 μm film as a plate substrate. .

  Subsequently, ultrafine PTFE particles were transported under the same conditions, and a 2 μm film was formed on a nickel plate.

  Next, the resist material was dissolved in acetone and peeled from the stainless steel plate to obtain an orifice plate.

  Thereafter, the orifice plate was heat-treated in an atmospheric furnace at 340 ° C. for 1 hour.

  The nozzle holes of the orifice plate thus produced had a desired dimensional outer shape, and the hole diameter tolerance was ± 0.3 μm.

  As an evaluation of water repellency, a contact angle with water on the outer surface was measured and found to be 122 °.

  A nozzle mold was prepared in the same manner as in Example 1. At this time, synchrotron light was used as an exposure light source.

  Similarly, nickel fine particles were formed as a 70 μm plate substrate by a gas deposition method, and PTFE was formed as a water repellent film at a thickness of 2 μm.

  After the resist was dissolved and peeled off from the mold substrate, heat treatment was performed in an atmosphere furnace at 340 ° C. for 1 hour.

  The tolerance of the hole diameter of the orifice plate thus prepared was ± 0.2 μm, and the contact angle of the outer surface with water was measured and found to be 124 °.

  A nozzle mold was prepared in the same manner as in Example 1. In this case, the light source for exposure may be ultraviolet light or synchrotron light.

  This mold substrate was placed on the drawing stage of the gas deposition apparatus shown in FIG. As the ultrafine particle generation chamber, two chambers for metal oxide and water repellent material were provided.

  As metal oxide fine particles, alumina was used, and this was put into a container (aerosol formation chamber 1) and vibrated to be aerosolized. As the metal oxide fine particles, oxides of titanium and silicon may be used in addition to the metal.

  As the water repellent material, PTFE (trade name: Lubron (registered trademark) L5-F) manufactured by Daikin Industries, Ltd. was used.

  First, ultrafine particles of alumina were transported using helium as a carrier gas, and 70 μm of alumina ultrafine particles were formed from a nozzle having a diameter of 1 mm attached to the tip of the transport tube.

  Subsequently, the PTFE ultrafine particles were conveyed, and a 2 μm film was formed on an alumina plate.

  After film formation, the substrate was heat-treated in an atmosphere furnace at 3400 ° C. for 1 hour.

  The tolerance of the hole diameter of the orifice plate produced in this way was ± 0.2 μm, and the contact angle with water on the outer surface was measured to be 120 °.

Gas deposition device schematic diagram Process flow diagram Cross section of orifice plate

Explanation of symbols

1 Substrate 2 Nozzle 3 Film formation chamber 4 Ultrafine particle formation chamber (Arc, high frequency induction heating, resistance heating method)
5 Materials (metal)
6 Arc heating 7 Ultrafine particle transport tube 8 Aerosol formation chamber 9 Gas transport tube 10 Water repellent film 11 Plate base material 12 Resist 13 Type fabrication substrate

Claims (16)

  In an orifice plate having an ink discharge port of an ink jet head, a step of patterning a nozzle mold by photolithography after applying a photosensitive resin, and a gas deposition method on the resin mold to form a substrate for the orifice plate An inkjet head manufacturing method comprising: a step of forming fine particles; and a step of continuously forming fine particles of a water repellent material thereon.   2. The method of manufacturing an ink jet head according to claim 1, wherein the film thickness of the photosensitive resin used for patterning the nozzle mold is 50 [mu] m or more in the orifice plate having the ink discharge port of the ink jet head.   2. The method of manufacturing an ink-jet head according to claim 1, wherein, in an orifice plate having an ink discharge port of the ink-jet head, exposure is performed using ultraviolet rays when patterning a nozzle mold.   2. The method of manufacturing an ink-jet head according to claim 1, wherein in the orifice plate having the ink discharge port of the ink-jet head, exposure is performed using synchrotron light when patterning the nozzle mold.   In an orifice plate having an ink discharge port of an inkjet head, when forming a base material of an orifice plate by a gas deposition method, metal fine particles are transported by a carrier gas and ejected from a nozzle to form a metal base material. The method of manufacturing an ink jet head according to claim 1.   When forming an orifice plate substrate by the gas deposition method in an orifice plate having an ink discharge port of an ink jet head, metal oxide fine particles are transported by a carrier gas and ejected from a nozzle to form a metal oxide substrate. The method of manufacturing an ink-jet head according to claim 1.   When forming a water-repellent film on an orifice plate having an ink discharge port of an inkjet head by a gas deposition method, fine particles of a fluorine-based polymer material are transported by a carrier gas and ejected from a nozzle to form the water-repellent film. The method of manufacturing an ink-jet head according to claim 1, wherein the ink-jet head is formed.   6. A method of manufacturing an ink jet head, wherein the metal fine particles according to claim 5 have an average particle size of 0.1 [mu] m or less.   7. A method for producing an ink jet head, wherein the metal oxide fine particles according to claim 6 have an average particle size of 0.1 [mu] m or less.   The method for producing an ink jet head, wherein the fluorine-based polymer material fine particles according to claim 7 have an average particle size of 1 μm or less.   11. A method for producing an ink-jet head, wherein the fluorine-based polymer material according to claim 7 or 10 is polytetrafluoroethylene.   9. A method of manufacturing an ink jet head, wherein the metal material fine particles according to claim 5 or 8 are any one of nickel, titanium, gold, silver and copper.   10. A method of manufacturing an ink jet head, wherein the metal of the metal oxide fine particles according to claim 6 or 9 is any one of aluminum, titanium, and silicon.   13. The method for producing an ink jet head according to claim 5, 8, or 12, wherein the metal fine particles are made into fine particles by arc discharge.   13. The method for producing an ink jet head according to claim 5, 8 or 12, wherein the metal material is made fine by high frequency induction heating.   13. The method for producing an ink jet head according to claim 5, 8, or 12, wherein the metal material is made fine by resistance heating.

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