JPH10278277A - Nozzle plate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nozzle plate having a water- and oil-repellency higher than that of a nozzle plate on which a water- and oil-repellent film is formed simply. SOLUTION: An aluminum metallic film 14 is formed on a surface of a substrate 12 by a metal vaporizing device and the substrate 12 is dipped into sulfuric acid and is subjected to anodic oxidation by making the metallic film 14 to be an anode. As a result, the surface of the metallic film 14 is eroded so that a surface 14a having a fractal structure is formed. After nozzles are formed on the substrate 12, a material having a water- and oil-repellency is coated by composite eutectoid plating to form a composite eutectoid plating layer 16. As a result, it is possible to enlarge a contacting angle between an ink drop and a nozzle plate, thereby enhancing the water- and oil-repellency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle plate used in an ink jet recording head for performing recording by ejecting ink droplets from a nozzle onto a recording medium and a manufacturing direction thereof.

[0002]

2. Description of the Related Art Conventionally, in an ink jet recording apparatus which performs recording by ejecting ink droplets from a nozzle onto a recording medium,
There is a problem in that the ink droplets around the nozzles are misaligned in the flight direction of the ink droplets due to wetting. In order to solve such a problem, it is known to perform a water / oil repellent treatment on the surface of the nozzle plate. For example, a technique of eutectoidally plating a fluorine-based polymer material on the surface of a nozzle plate has been proposed (JP-A-5-116327).

[0003]

By the way, in the ink jet recording apparatus, it is required to further increase the recording speed. However, when the ink droplets are ejected from the nozzles at a high speed, the ink droplets are discharged on the recording medium. In many cases, the ink droplets bounce off and adhere around the nozzles, and the ink droplets ejected from the nozzles splash and adhere around the nozzles in many cases. Is reduced. FIG. 7 is an explanatory view showing a state where ink droplets adhere to a conventional nozzle plate. The larger the contact angle θ between the ink droplet 32 and the nozzle plate 34 subjected to the water / oil repellent treatment, the greater the water / water repellency.
Although oil repellency is high, as shown in FIG. 7, θ is a little over 90 degrees. That is, if the contact angle is as large as above, it is not possible to cope with high-speed printing in which ink droplets often adhere around the nozzles.

Accordingly, an object of the present invention is to realize a nozzle plate having higher water / oil repellency than a nozzle plate simply having a water / oil repellent film formed thereon, and a method of manufacturing the same.

[0005]

According to the present invention, in order to achieve the above object, the present invention provides a nozzle plate in which a nozzle for ejecting ink is formed on a substrate.
Technical means is adopted in which at least the surface of the substrate around the portion where the nozzle is formed is formed in a fractal structure covered with a water-repellent / oil-repellent material.

According to a second aspect of the present invention, in the nozzle plate according to the first aspect, at least a surface of the substrate around a portion where the nozzle is formed is covered with a fractal coated with a water / oil repellent material. Technical means of being formed of a metal film having a structure surface is employed.

According to a third aspect of the present invention, in the nozzle plate according to the first or second aspect, the surface of the fractal structure of the metal film is subjected to composite eutectoid plating with the water / oil repellent material. The technical means of becoming

According to a fourth aspect of the present invention, in the nozzle plate according to any one of the first to third aspects, a technical means is adopted in which the water / oil repellent material is a fluororesin. I do.

According to a fifth aspect of the present invention, in the nozzle plate according to any one of the second to fourth aspects, the fractal structure on the surface of the metal film oxidizes the surface of the metal film. The technical means of being formed by the above method is adopted.

According to a sixth aspect of the present invention, in the nozzle plate according to any one of the first to fifth aspects, a technical means is adopted in which the substrate is formed of a synthetic resin material. I do.

According to a seventh aspect of the present invention, there is provided an ink jet recording apparatus comprising the nozzle plate according to any one of the first to sixth aspects, wherein ink is recorded from the nozzles formed on the nozzle plate. A technical means of performing recording by discharging toward a medium is employed.

According to an eighth aspect of the present invention, in the method for manufacturing a nozzle plate in which nozzles for ejecting ink are formed on a substrate, a water-repellent / oil-repellent property is provided at least around the nozzles on the substrate on which the nozzles are formed. The technical means of having a step of forming a surface of a fractal structure coated with a material is employed.

According to a ninth aspect of the present invention, in the method of manufacturing a nozzle plate according to the eighth aspect, a film forming step of forming a metal film on the substrate, and after the film forming step, An oxidation step of oxidizing a metal film formed at least on a surface around a portion where the nozzle is formed to form the fractal structure on the surface of the metal film; and after the oxidation step, the nozzle is formed on the substrate. And a coating step of coating the surface of the metal film with a water / oil repellent material after the nozzle forming step.

According to a tenth aspect of the present invention, in the method for manufacturing a nozzle plate according to the ninth aspect, the oxidization is performed by immersing the metal film in an acid solution and performing electrolysis using the metal film as an anode. Adopt the technical means of doing.

According to an eleventh aspect of the present invention, in the method for manufacturing a nozzle plate according to the ninth or tenth aspect, the coating of the water-repellent / oil-repellent material is formed of a metal film on which the fractal structure is formed. A technical means is employed in which the above-mentioned water-repellent / oil-repellent material is subjected to composite eutectoid plating on the surface.

[0016]

According to the invention as set forth in claims 1 to 11,
At least the surface of the substrate around the portion where the nozzle is formed is formed in a fractal structure covered with a water-repellent / oil-repellent material, so that the surface is more water-repellent / repellent than a substrate not formed in a fractal structure. Oiliness can be increased.
In other words, by coating the surface formed in the fractal structure with a water / oil repellent material, the surface can be made to have a super water / oil repellency. Can also enhance water and oil repellency. Here, fractal means a general term for figures having non-integer dimensions, and fractal structure means a structure formed in such a figure. For example, as described in an embodiment of the invention described below, it means a structure having a complicated uneven shape.

The nozzle plate may have a fractal structure surface coated with a water-repellent / oil-repellent material at least around the nozzle on the substrate on which the nozzle is formed. It can be manufactured by having a forming step.

In particular, when the surface of at least the portion of the substrate around which the nozzle is formed is formed of a metal film, the metal itself is hydrophilic, so that the fractal structure alone results in a super-water-repellent material. Although it is not possible to make the metal surface oil-repellent, the metal surface having a fractal structure is coated with a water-repellent and oil-repellent material to make the metal surface super water-repellent and oil-repellent. Can be.

It is preferable that the surface of the fractal structure of the metal film is formed by composite eutectoid plating with the water-repellent and oil-repellent material.
In other words, if the surface of the fractal structure of the metal film is too thick, the fractal structure is impaired if the film thickness of the water-repellent / oil-repellent material to be coated is too large, and the film cannot be made super-water / oil-repellent. Use composite eutectoid plating that has excellent bonding strength with the film.

Further, the water-repellent / oil-repellent material is water-repellent / oil-repellent.
From the viewpoint of excellent oil repellency, it is desirable to use a fluorine tree as in the invention of the fourth aspect.

Further, it is desirable that the fractal structure on the surface of the metal film is formed by oxidizing the surface of the metal film. That is, by eroding the surface of the metal film by oxidation, a fractal structure can be easily formed on the surface of the metal film.

In particular, according to the ninth aspect of the present invention, a metal film is formed on the substrate by a film forming step, and at least a nozzle of the substrate is formed by an oxidation step after the film forming step. The metal film formed on the surface around the site is oxidized to form a fractal structure on the surface of the metal film, a nozzle forming step forms a nozzle on the substrate after the oxidation step, and a coating step forms the nozzle. After the forming step, the surface of the metal film is coated with a water-repellent / oil-repellent material to produce a nozzle plate in which at least the surface of the substrate around the portion where the nozzle is formed is made super-water-repellent / oil-repellent. it can.

The oxidation can be carried out by immersing the metal film in an acidic solution and performing electrolysis using the metal film as an anode.

Further, the coating of the water / oil repellent material is
As in the eleventh aspect of the present invention, it can be performed by complex eutectoid plating of the water-repellent / oil-repellent material on the surface of the metal film on which the fractal structure is formed.

It is desirable that the substrate is formed of a synthetic resin material. That is, the nozzle can be easily processed by forming the substrate from a synthetic resin.

Further, an ink jet recording apparatus which performs recording by discharging ink from the nozzles formed on the nozzle plate toward a recording medium is provided as in the invention of claim 7. It is desirable to provide the nozzle plate according to any one of 6. That is, since the nozzle plate is made super-water-repellent and oil-repellent,
Even when printing is performed at high speed, the ink droplets are unlikely to adhere to the surface around the nozzles, and there is no risk that the landing positions of the ink droplets ejected from the nozzles will shift.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows the first
2A to 2C are cross-sectional views illustrating the nozzle plate in each manufacturing process illustrated in FIG. 1, illustrating a manufacturing process of a manufacturing method of the nozzle plate according to the embodiment.
FIG. 3 is an explanatory diagram of a metal deposition apparatus. FIG. 4A is an explanatory diagram showing a metal film having a fractal structure, and FIG. 4B is an explanatory diagram showing a state in which a metal film having a fractal structure is coated with a water / oil repellent material. is there. FIG. 5 is an explanatory diagram of a laser processing apparatus used for processing the nozzle.

First, a film forming step for forming a metal film on the surface of a substrate will be described. In the present embodiment, as a material for forming the substrate, a heat-resistant polymer material is used because it has a high melting point and softening point, and has high mechanical strength at high temperatures, and has high acid resistance and chemical resistance. . Among them, the acid-resistant polyimide is preferably used because it is hardly oxidized in a subsequent oxidation step and can withstand continuous use at a high temperature of 300 ° C. or more. Further, as a material for forming the metal film, aluminum, nickel,
Nickel alloys such as nickel-cobalt alloys, nickel-phosphorus alloys, nickel-boron alloys, copper, zinc, tin, etc. are used. Preferably, aluminum is easily oxidized in a later oxidizing configuration, is lightweight, and has abrasion resistance. It is selected because of its superiority.

The metal film 14 formed on the surface 12a of the substrate 12 shown in FIG. 2A is formed by using a metal vapor deposition device shown in FIG. As shown in FIG. 3, the metal vapor deposition device 40 is provided with a vacuum container 41, and an exhaust port 42 for exhausting gas in the vacuum container 41 is formed on a bottom surface of the vacuum container 41. Further, below the inside of the vacuum vessel 41,
An electron gun 43 and electrons 44 emitted from the electron gun 43
An aluminum evaporation source 45 for evaporating aluminum atoms is provided, and a base plate 46 attached to the lower surface of the substrate 12 and rotated by a driving mechanism (not shown) is provided above the inside.

Then, a pump (not shown) connected to the exhaust port 42 is driven to evacuate the inside of the vacuum vessel 41, the aluminum evaporation source 45 is heated, the base plate 46 is rotated, and the electron gun 43 is started. Electrons 44 emitted from an electron gun 43 collide with an aluminum evaporation source 45, and aluminum atoms 47 evaporate from the aluminum evaporation source 45. The evaporated aluminum atoms 47 are deposited on the surface 12a of the substrate 12, and as shown in FIG.
A metal film 14 made of aluminum is formed on the surface 12a of Step 2 (Step 100). In this embodiment, the substrate 12
Is 75 μm, and the thickness of the metal film 14 is 0.1 μm.
It is from 05 μm to 1 μm.

Next, the step of oxidizing the aluminum metal film 14 formed on the surface 12a of the substrate 12 to form a fractal structure will be described. The substrate 12 is immersed in sulfuric acid, the metal film 14 is set as an anode, and anodic oxidation is performed (step 200). By this oxidation, the surface 14a of the metal film 14 made of aluminum is eroded, and as shown in FIG. 4A, formed into a surface structure having a complicated uneven shape, that is, a fractal structure. Here, fractal is
A fractal structure means a structure formed in such a figure.

For example, it means a structure having a so-called self-similarity in which a structure obtained by reducing oneself to a fraction is part of itself. When a fractal figure is composed of b figures which are themselves reduced to 1 / a, the dimension (similarity dimension) of the figure is logb / log
given by a. For example, if the figure drawn by the surface 14a of the metal film 14 shown in FIG. 4A is a = 3 and b = 4, log4 / log3 = 1.26 ···・ It is a dimensional figure.

Next, a nozzle forming step for forming a nozzle on the substrate 12 in which the metal film 14 has been oxidized by the oxidizing step will be described. The processing of the nozzle is performed using a laser processing apparatus shown in FIG. An excimer laser light source 21 that emits an excimer laser beam is used as the laser light source.
The nozzle plate 12 is set on the processing table 31, and the processing position of the nozzle is adjusted by moving the processing table 31 by a moving mechanism (not shown). When the excimer laser light source 21 is activated, an excimer laser beam 22 is emitted from the excimer laser light source 21, and the emitted excimer laser beam 22 is reflected by a bend mirror 23, and
4 is incident.

The excimer laser beam 22 incident on the beam expander 24 is expanded by the beam expander 24 and emitted. The excimer laser beam 22 emitted from the beam expander 24 is incident on a homogenizer 25, and the homogenizer 25 converts the incident excimer laser beam 22 into a plurality of excimer laser beams 2.
The excimer laser beam 22 is condensed and emitted. The excimer laser beam 22 emitted from the homogenizer 25 is
The light is reflected by the bend mirror 26 and enters the mask 27. The mask 27 forms the emitted excimer laser beam 22 into a pattern having a shape corresponding to the nozzle shape and emits the same.

The excimer laser beam 22 emitted from the mask 27 is incident on a field lens 28. The field lens 28 converts the incident excimer laser beam 22 into a parallel beam and emits the same. Field lens 2
The excimer laser beam 22 emitted from 8 is reflected by the bend mirror 29 and enters the imaging optical system 30. The imaging optical system 30 forms an image of the incident excimer laser beam 22 on the nozzle plate 12. And
In the portion of the nozzle plate 12 irradiated with the excimer laser beam 22, the polyimide molecules are photo-decomposed and scattered due to the ablation phenomenon of the excimer laser beam 22, and the nozzle 18 is formed as shown in FIG. (Step 300). After forming the metal film 14, the nozzle 18
Is formed, the metal plate 14 can be a nozzle plate formed up to the peripheral edge 18 a of the nozzle 18 on the ink ejection side. In this embodiment, Kr having a wavelength of 248 nm is used as the excimer laser beam 22.
An F excimer laser beam is used.

Next, a description will be given of a plating step of performing composite eutectoid plating on the metal film 14 of the substrate 12 on which the nozzle has been formed by the above-described nozzle forming step. In the present embodiment, as the water-repellent / oil-repellent material, a fluorine-based polymer material excellent in water / oil repellency is used. Among them, preferably, polytetrafluoroethene (hereinafter abbreviated as PTFE), Polyperfluoroalkoxybutadiene (PF
A), polyfluorovinylidene, polyfluorovinyl, etc., due to their high water and oil repellency, alone or
Mix and use them.

Further, the ink used in the ink jet recording ^{apparatus, Li +, Na +, K} +, Ca 2+, Cl -, S
Since ions such as O ₄ ⁻ , SO ₃ ⁻ , NO ₃ ⁻ , and NO ₂ ⁻ are mixed as impurities, the method of composite eutectoid plating is hardly affected by these ion species, and
Use a highly durable electrolytic method. Either an electrolytic method or an electroless method can be used, but in the present embodiment, an electroless method capable of controlling the film thickness to be uniform and thin is used. That is, if the thickness of the composite eutectoid plating layer coated on the surface 14a of the metal film 14 is too large, the surface 14a does not have a fractal structure, and thus the electroless method is used.

In the present embodiment, the composition of the plating solution is 70 g / l of nickel sulfamate, 30 g / l of boric acid as a pH buffer, and 55 g / l of PTFE. 0 to 4.5, and the plating temperature is 50 ° C. Then, the substrate 12 is immersed in a plating solution having the above composition, and the substrate 1 is gently stirred with the plating solution.
2 is subjected to composite eutectoid plating (step 40).
0).

As a result, as shown in FIG. 2C, the nozzle plate 10 in which the composite eutectoid plating layer 16 was formed on the metal film 14 could be manufactured. When the composite eutectoid plating layer 16 was observed, as shown in FIG. 4B, a nickel plating layer 16 was formed on the surface 14a of the metal film 14 having a fractal structure with a thickness on the order of submicrons. I understood that. Further, since the thickness of the composite eutectoid plating layer 16 is small, the surface 14
It was found that the fractal structure of a was maintained.

As shown in FIG. 2C, the composite eutectoid plating layer 16 is formed evenly on the metal film 14, and extends to the peripheral edge 18a of the nozzle 18 on the ink discharge side. It was found that was formed. That is, it was found that there was no portion that was not subjected to the composite eutectoid plating around the nozzle 18.

Next, the nozzle plate 10 manufactured as described above is used.
In order to examine the water repellency and oil repellency of the ink, ink droplets were attached to the nozzle plate 10 and the contact angle was measured. FIG.
FIG. 4 is an explanatory diagram showing a state in which ink droplets adhere to the nozzle plate 10. Ink droplet 32 and plating layer 16
As a result of measuring the contact angle θf, it was found that θf was about 160 degrees, which was considerably larger than the conventional contact angle θ of 90 degrees or less. That is, it was found that the nozzle plate 10 of this embodiment has considerably higher water and oil repellency than the conventional nozzle plate 34. Note that the contact angle θf can be expressed by the following equation.

Cos θ = (α13−α12) / α23 (1)

In the equation (1), α12, α13 and α23 represent three forces acting on the contact point P between the ink droplet 32 and the composite eutectoid plating layer 16, as shown in FIG.
12 is the interfacial tension between the composite eutectoid plating layer 16 and the ink droplet 32, α13 is the interfacial tension between the composite eutectoid plating layer 16 and the gas, and α23 is the gas and the ink droplet 32.
(See FIG. 6).

As described above, according to the nozzle plate manufacturing method of the first embodiment, a nozzle plate having higher water and oil repellency than the conventional nozzle plate can be manufactured. Therefore, if a print head is manufactured using the nozzle plate, even when printing is performed at a high speed, ink droplets rebounding from the printing paper are unlikely to adhere to the surface around the nozzle 18, and the attached ink Since the landing positions of the ink droplets ejected from the nozzles 18 do not shift due to the droplets, a recording head with high recording quality can be realized.

In the above embodiment, the electroless plating method is used as the method for performing the composite eutectoid plating. However, the electrolytic plating method may be used. The current density of the cathode used in this case is, for example, 3 A / dm ³ . In the above embodiment, the composite eutectoid plating is performed after processing the nozzle. However, the composite eutectoid plating may be performed after the composite eutectoid plating. Furthermore, the nozzle plate and the method of manufacturing the same according to the present invention can be applied to a recording having a nozzle plate, such as a so-called on-demand type ink jet recording apparatus, such as an electromechanical conversion type using a piezo element and an electrothermal conversion type using a heating element. As long as it is a device, it can be applied to a nozzle plate used in any recording device. Step 100 corresponds to the film forming step, step 200 corresponds to the oxidation step, step 300 corresponds to the nozzle forming step, and step 400 corresponds to the covering step.

[0046]

As described above, according to the present invention, the water repellency and the oil repellency are higher than those of the nozzle plate in which the water repellent and oil repellent film is formed.
A nozzle plate having oil repellency and a method for manufacturing the same can be realized. Therefore, if the nozzle plate of the present invention is used for, for example, a nozzle plate of a recording head of an inkjet recording apparatus, an inkjet recording apparatus capable of performing high-quality recording can be realized.

[Brief description of the drawings]

FIG. 1 is a process chart showing a manufacturing process of a method for manufacturing a nozzle plate according to an embodiment of the present invention.

2 (A) to 2 (C) are cross-sectional explanatory views of a nozzle plate in each manufacturing process shown in FIG. 1;

FIG. 3 is an explanatory diagram of a metal deposition apparatus.

FIG. 4A is an explanatory diagram showing a metal film having a fractal structure, and FIG. 4B is an explanatory diagram showing a state in which a metal film having a fractal structure is coated with a water / oil repellent material. is there.

FIG. 5 is an explanatory diagram of a laser processing apparatus used for processing a nozzle.

FIG. 6 is an explanatory diagram showing a state in which ink droplets adhere to a nozzle plate.

FIG. 7 is an explanatory diagram showing a state where ink droplets adhere to a conventional nozzle plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Nozzle plate 12 Substrate 14 Metal film 16 Composite eutectoid plating layer 18 Nozzle 20 Laser processing device 21 Excimer laser light source 40 Metal vapor deposition device 45 Aluminum evaporation source θf Contact angle

Claims (11)

[Claims] 1. A nozzle plate in which nozzles for ink ejection are formed on a substrate, wherein at least a surface of the substrate around a portion where the nozzles are formed has a fractal structure covered with a water-repellent / oil-repellent material. A nozzle plate characterized by being formed. 2. The substrate according to claim 1, wherein at least a surface around a portion where the nozzle is formed is formed of a metal film having a fractal structure surface coated with a water / oil repellent material. The nozzle plate according to claim 1. 3. The surface of the fractal structure of the metal film,
The nozzle plate according to claim 1, wherein the nozzle plate is formed by composite eutectoid plating with the water / oil repellent material. 4. The nozzle plate according to claim 1, wherein the water / oil repellent material is a fluororesin. 5. A fractal structure on a surface of the metal film,
The nozzle plate according to any one of claims 2 to 4, wherein the nozzle plate is formed by oxidizing a surface of the metal film. 6. The nozzle plate according to claim 1, wherein the substrate is formed of a synthetic resin material. 7. A recording apparatus comprising the nozzle plate according to any one of claims 1 to 6, wherein recording is performed by discharging ink from the nozzles formed on the nozzle plate toward a recording medium. An ink jet recording apparatus characterized by the above-mentioned. 8. A method of manufacturing a nozzle plate in which ink jet nozzles are formed on a substrate, wherein a fractal structure in which at least the periphery of the nozzles of the substrate on which the nozzles are formed is coated with a water / oil repellent material. Forming a surface of the nozzle plate. 9. A film forming step of forming a metal film on the substrate, and after the film forming step, oxidizing a metal film formed on at least a surface of the substrate around a portion where the nozzle is formed. An oxidizing step of forming the fractal structure on the surface of the metal film; a nozzle forming step of forming the nozzle on the substrate after the oxidizing step; Water repellent on the surface
The method for manufacturing a nozzle plate according to claim 8, comprising: a coating step of coating an oil-repellent material. 10. The method according to claim 9, wherein the oxidation is performed by immersing the metal film in an acid solution and performing electrolysis using the metal film as an anode. 11. The water-repellent / oil-repellent material is coated on the surface of the metal film on which the fractal structure is formed.
The method for manufacturing a nozzle plate according to claim 9, wherein the method is performed by performing composite eutectoid plating of an oil-repellent material.