JPH05201005A - Delivery nozzle plate for ink jet recording device and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a liquid repellent film without being influenced by fine irregularities of the surface of a nozzle plate in an ink nozzle plate or air nozzle plate of an ink jet head, wherein a liquid repellent treatment has been applied to said ink nozzle plate or air nozzle plate using a chemical adsorption monomolecular film containing fluorine. CONSTITUTION:A polyimide layer 117 as under layer is formed on the surfaces of nozzle plates 102, 103 which have been processed to smoothen fine irregularities of the surfaces thereof and a chemical adsorption monomolecular film 118 containing fluorine is formed on the layer 117 to form a liquid repellent film 116. As an under layer, another material such as metallic film containing hydroxyl group or oxygen atom in its surface can be employed and by forming an intermediate layer between under layer and monomolecular film, the density of the monomolecular film can be further raised and furthermore material having relatively smaller degree of combination with monomolecular film can be used as under layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge nozzle plate such as an ink discharge nozzle plate or an air discharge nozzle in a recording head of an ink jet recording apparatus and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, this type of ejection nozzle plate for an ink jet recording apparatus is required to have liquid repellency on its surface in order to stably generate and fly ink droplets. A liquid-repellent coating film is formed on the surface. Such a liquid-repellent treatment is necessary, for example, in the ink nozzle plate to prevent the collapse of the meniscus and to maintain stable ejection, and in the air ejection nozzle plate, to prevent the adhesion of ink droplets or paper dust. It is necessary to do. Further, as a conventional liquid repellent treatment method for an ejection nozzle plate for an inkjet recording apparatus, F
A method of coating a fluorine-based polymer such as EP and a method of treating a fluorine-based chemisorption monomolecular film are known.

[0003]

[Problems to be Solved by the Invention] However, FEP
The coating of the fluorine-based polymer is typically performed by spraying or brush coating. Although the liquid-repellent property against ink, that is, the effect of preventing wetting, is excellent, the adhesion of the fluorine-based polymer is weak as a characteristic. However, it has drawbacks such as being easily damaged or peeled off during cleaning or exposed to the outside.

On the other hand, in the case of the fluorine-based chemical adsorption monomolecular film processing method, it is possible to impart liquid repellency to the entire surface of the nozzle plate simply by immersing the nozzle plate in the organic solvent-based processing liquid for a certain period of time. Therefore, there is an advantage that cost can be reduced by mass production. Further, since it is bonded to the substrate by chemical adsorption, the formed liquid-repellent monomolecular film has a characteristic that it has a uniform film thickness of nanometer level and is very strong. On the other hand, since the film thickness is extremely thin, if the surface of the nozzle substrate that is to have liquid repellency has fine irregularities, sufficient liquid repellency cannot be obtained and the ejection characteristics are affected. was there. That is, generally, in a portion where the surface is slightly roughened, the liquid repellency is inferior and it becomes easy to wet, so even if the liquid repellent treatment of the monomolecular film is performed on the roughened surface, it can be seen microscopically. For example, partial wetting occurs, which adversely affects the ejection characteristics.

Further, in the case of the nozzle plate of the ink jet head, not only macroscopic liquid repellency but also microscopic liquid repellency in the vicinity of the nozzle becomes an important problem. In particular, when the nozzle is processed by etching, etc., the inner diameter surface and inner edge of the nozzle are easily roughened, so even if a monomolecular film is formed, sufficient liquid repellency cannot be obtained, and the meniscus becomes unstable or bends. There is a problem in that abnormal discharge occurs and ink droplets and paper dust easily adhere.

The present invention solves such a conventional problem, and makes full use of the liquid repellency of a chemisorption monomolecular film containing fluorine without being affected by fine irregularities on the surface of the nozzle plate. An object of the present invention is to provide a discharge nozzle plate for an ink jet recording apparatus and a method for manufacturing the same.

[0007]

In order to achieve the above object, the discharge nozzle plate for an ink jet recording apparatus of the present invention and the method for manufacturing the same have a smooth surface on the surface of the discharge nozzle plate for an ink jet recording apparatus. A base layer for obtaining is formed, and a chemisorption monomolecular film containing fluorine is formed on the base layer.

[0008]

According to the present invention, even if there are fine irregularities on the surface of the nozzle plate, the irregularities are smoothed by the underlayer, so that the chemisorption monomolecular film containing fluorine on the nozzle plate is not irregularized. It can be formed smoothly.

The underlayer is formed, for example, by applying polyimide to the surface of the nozzle plate, and its film thickness can be controlled according to the size of the irregularities on the surface of the nozzle plate. By forming a chemisorption monomolecular film containing fluorine on such a polyimide underlayer, it is possible to impart liquid repellency to the entire nozzle plate. Since the polyimide contains oxygen atoms, it is easily chemisorbed to the monomolecular film containing fluorine, and a strong bond can be realized.
If you want to further increase the density of the monolayer or if you use a material that has a relatively weak bond with the monolayer for the underlayer, form an intermediate layer between the underlayer and the monolayer. You can

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a static control inkjet recording apparatus to which the present invention is applied.
In FIG. 1, 101 is a body member, 102 is an air nozzle plate, and 103 is an ink nozzle plate, and these constitute an inkjet head. Body member 1
The air nozzle 108 of the air nozzle plate 102 made of an insulating material joined to the tip of the outer wall 01 of the ink nozzle plate 101 is the ink nozzle 10 of the ink nozzle plate 103 also made of an insulating material.
It is formed so as to face 7. Air supply source 112
The pressurized air generated in 1 is supplied from the air supply passage 110 to the air chamber 1.
04, the air nozzle plate 102 and the ink nozzle plate 1
03 through the air layer 105, and flows out from the air nozzle 108. Since this air flow is rapidly changing in the vicinity of the air nozzle 108, a sharp pressure gradient is generated in the space from the ink nozzle 107 to the air nozzle 108. On the other hand, the ink chamber 106 adjacent to the ink nozzle 107 is in communication with the ink supply source 113 via the ink supply path 111, and the ink in the ink supply source 113 is applied with a constant air pressure from the air supply source 112. ing. The signal source 115 is connected to an electrode 109 provided near the outlet of the air nozzle 108 and an electrode 114 provided around the ink nozzle 107 facing the ink chamber 106, and the ink is oily with high electrical resistance. Therefore, a potential difference is generated between the electrode 109 and the ink held in the opening of the ink nozzle 107. Due to the electrostatic force due to this potential difference, the meniscus of the ink generated at the opening of the ink nozzle 107 is extended toward the air nozzle 108. Further, since a sharp pressure gradient is generated in the space from the ink nozzle 107 to the air nozzle 108, when the ink meniscus generated at the opening of the ink nozzle 107 is stretched by a certain amount or more, the ink meniscus is accelerated by the pressure gradient to fly from the air nozzle 108. To do.

FIG. 2 is an enlarged sectional view of the vicinity of the nozzle in the above-mentioned ink jet head. In FIG. 2, 1
Reference numeral 16 denotes a liquid repellent film having excellent oil repellency and antifouling property, which is formed on the surface of the ink nozzle plate 103 on the side of the air nozzle plate 102 in order to stabilize the formation of the meniscus of the ink nozzle 107 and stabilize the generation of droplets. And the air nozzle plate 10
2 To prevent stains on the surface by ink and paper dust,
It is formed on the front and back surfaces of the air nozzle plate 102 and the wall surface of the air nozzle 108. This liquid repellent film 116 is
As shown in an enlarged view in FIG. 3, it comprises a lower polyimide layer 117 as a base layer and an upper chemical adsorption monomolecular film 118 containing fluorine. Polyimide has good adhesion to the glass nozzle plates 102 and 103, and is also a material having excellent solvent resistance, heat resistance, and electrical insulation. In addition,
In this embodiment, the air nozzle plate 102 and the ink nozzle plate 103 are made of photosensitive glass, and the air nozzle 108 and the ink nozzle 107 are formed by etching.

(Embodiment 1) Next, a first embodiment of the present invention will be described. Roughness and unevenness are observed on the surfaces of the nozzle plates 102 and 103 after finishing the hole processing, the wall surfaces and the edge portions of the nozzles 108 and 107. Therefore, the nozzle plate 1
Polyimide diluted with thinner is applied to 02 and 103 with a spray gun to form a polyimide layer 117. The film thickness of the polyimide layer 117 can be easily controlled by changing the number of times of coating. After coating, it is baked and the thinner is evaporated to smooth the surface.

Next, a chemisorption monomolecular film layer 118 containing fluorine.
A process for forming the will be described. First, a substance containing a fluorocarbon group and a chlorosilane group (a fluorocarbon surfactant), for example, CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl
₃ at a concentration of about 1% by weight, a non-aqueous solvent, specifically 8
Nozzle plates 102, 103 were prepared by preparing a solution prepared by dissolving 0 wt% n-hexadecane (toluene, xylene, dicyclohexyl, etc.), 12 wt% carbon tetrachloride and 8 wt% chloroform in a solvent. Is immersed for about 2 hours. Polyimide layer 117 of nozzle plates 102 and 103
Contains oxygen atoms, and the oxygen atoms react with moisture in the air, so that a hydroxyl group exists on the surface of the polyimide layer 117. Therefore, the SiCl group contained in the substance containing the linear carbon fluoride group and the chlorosilane group reacts with the hydroxyl group to cause a dehydrochlorination reaction, and the nozzle plates 102, 1
The bond represented by the chemical formula (Formula 1) is formed over the entire surface of No. 03.

[0014]

[Chemical 1]

FIG. 4 shows a state in which the monomolecular film 118 containing fluorine is chemically bonded to the surface of the polyimide layer 117.
A film thickness of about 15Å is formed. At this time, the monomolecular film 118 is extremely strongly chemically bonded to the polyimide layer 117.

An attempt was made to actually use the nozzle plates 102 and 103 having the monomolecular film 118 formed thereon. As a result, compared to the conventional nozzle plate coated with a fluorine-based polymer, the liquid repellency to ink, that is, the anti-wetting effect is no better than that of the conventional nozzle plate, and the surface is scratched or rubbed off with plastic or paper. Did not occur.

(Second Embodiment) Next, a second embodiment for increasing the density of the monomolecular film 118 will be described. The nozzle plates 102 and 103 for which the nozzle processing has been completed are prepared, and similarly to the first embodiment, polyimide is applied with a film thickness to such an extent that the surface unevenness is eliminated, and is baked to form the polyimide layer 117. .. Next, a substance containing a plurality of trichlorosilyl groups (for example, SiC
l ₄ , SiHCl ₃ , SiH ₂ Cl ₂ , or Cl-
_{(SiCl 2 O) n -SiCl 3} (n is an integer). In particular,
If SiCl ₄ is used, since the molecule is small and the activity for the hydroxyl group is large, the effect of uniformly hydrophilizing the surfaces of the nozzle plates 102 and 103 is large. ) Is mixed with a non-aqueous solution (for example, a solution of 1% by weight dissolved in a chloroform solvent).
Soak for about a minute. As a result, as shown in FIG. 5A, since hydrophilic OH groups are present on the surface of the polyimide layer 117, a dehydrochlorination reaction occurs on the surface and a chlorosilane monomolecular film of a substance containing a plurality of trichlorosilyl groups. Is formed.

For example, if SiCl ₄ is used as the substance containing a plurality of trichlorosilyl groups, the nozzle plates 102, 1
Since a small amount of hydrophilic OH groups is exposed on the surface of 03, a dehydrochlorination reaction occurs on the surface, and the molecule is fixed to the surface via the —SiO— bond as shown in Chemical formula 2.

[0019]

[Chemical 2]

Thereafter, by washing with a non-aqueous solvent such as chloroform, and further washing with water to cause a reaction, the SiCl ₄ molecules that have not reacted with the polyimide layer 117 are removed, and the surfaces of the nozzle plates 102 and 103 are removed. 5 includes a plurality of silanol groups represented by the chemical formula of
A siloxane monomolecular film 119 as an intermediate layer as shown in (b) is obtained.

[0021]

[Chemical 3]

The siloxane monomolecular film 119 obtained here
Is completely bonded to the polyimide layer 117 via a chemical bond of —SiO—, and thus is not peeled off. In addition, the obtained siloxane monomolecular film 119 has many Si—OH bonds on the surface, about 3 times as many as the initial hydroxyl groups are generated, and the density of the monomolecular film 118 containing fluorine formed next is reduced. Can be raised.

Then, as in the first embodiment, a solution containing a linear fluorocarbon group and a chlorosilane group (a fluorocarbon surfactant) is dissolved in a non-aqueous solvent at a predetermined concentration, For example, CF ₃ (CF ₂ ) ₇ (CF ₂ ) ₂ Si
80 wt% n-hexadecane dissolved at a concentration of about 1 wt% using Cl ₃ , 12 wt% carbon tetrachloride, 8 wt%
Chloroform solution was prepared and Si-OH was added to the surface.
The nozzle plates 102 and 103 formed with the siloxane monomolecular film 119 having many bonds are immersed for about 1 hour. Then, the bond of (Chemical Formula 1) is generated on the surfaces of the nozzle plates 102 and 103 as in the first embodiment, and as shown in FIG. 5C, the monomolecular film 118 containing fluorine is formed as the lower siloxane. The nozzle plate 102, while chemically bonded to the monomolecular film 119,
A film having a thickness of about 15 Å could be formed on the entire surface of 103.

The fluorine-containing monomolecular film 118 ensures liquid repellency and antifouling properties equivalent to those of a fluorine-based polymer film, does not peel off even when a peeling test is performed, and has high abrasion resistance. Was also realized. The method of forming the intermediate layer between the underlayer and the monomolecular film as in the second embodiment is also applicable to the case where a material having a relatively small proportion of oxygen atoms and hydroxyl groups is used as the underlayer. It is valid.

In each of the above examples, CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ SiCl ₃ was used as the fluorocarbon surfactant.
However, if a C = C or C≡C group is added to or incorporated in the alkyl chain, the monolayer can be cross-linked by irradiation at about 5 megarads, which further improves the hardness of the monolayer. It is also possible to let.

Further, when the fluorocarbon-based liquid repellent treatment is performed, the OH groups on the surface can be increased and the density of the monomolecular film can be increased, so that not only a resin such as polyimide but also a base layer can be used.
It is also possible to use a metal film. An oxide film is naturally formed on the surface of the metal film, and OH is formed on the surface of the oxide film.
The presence of the group allows the monolayer to chemisorb. When PVD is used for forming the metal film, there is an advantage that the number of steps can be reduced as compared with the case where the resin is applied.

[0027]

As described above, according to the present invention, a base layer for smoothing the surface is formed on the surface of the discharge nozzle plate for an ink jet recording apparatus which has been processed, and the chemical adsorption containing fluorine is formed on the base layer. Since a monomolecular film is formed, sufficient liquid repellency can be obtained without being affected by minute irregularities on the nozzle surface, and peeling, abnormal ejection, and paper powder or ink droplet adhesion can be prevented. It is possible to realize a discharge nozzle plate for an ink jet recording apparatus that is unlikely to occur and a manufacturing method thereof.

By forming an intermediate layer containing a hydroxyl group or an oxygen atom on at least the surface between the underlayer and the monomolecular film, the density of the monomolecular film can be further increased, and the monomolecular film and A material having a relatively weak bond may be used as the underlayer.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a static control inkjet recording apparatus to which an embodiment of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of the vicinity of the nozzle in the same device.

FIG. 3 is an enlarged schematic view of a nozzle plate surface in the same device.

FIG. 4 is an enlarged conceptual view of the nozzle plate surface for explaining the first embodiment of the present invention.

FIG. 5 is an enlarged conceptual view of a nozzle plate surface for explaining a second embodiment of the present invention.

[Explanation of symbols]

 101 Body Member 102 Air Nozzle Plate 103 Ink Nozzle Plate 104 Air Chamber 105 Air Layer 106 Ink Chamber 107 Ink Nozzle 108 Air Nozzle 109 Electrode 110 Air Supply Channel 111 Ink Supply Channel 112 Air Supply Source 113 Ink Supply Source 114 Electrode 115 Signal Source 116 Liquid Repellent Film 117 Polyimide layer (base layer) 118 Chemisorption monomolecular film containing fluorine 119 Siloxane monomolecular film (intermediate layer)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Gen Oda, 3-10-1 Higashisanda, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd. (72) Inventor, Koichi Saito, East Tama-ku, Kawasaki City, Kanagawa Prefecture 3-10-1, Mita Matsushita Giken Co., Ltd.

Claims (7)

[Claims] 1. A discharge nozzle for an ink jet recording apparatus, comprising an underlayer formed on the surface of a nozzle plate for smoothing the surface, and a chemical adsorption monomolecular film containing fluorine formed on the underlayer. Board. 2. A step of forming an underlayer for smoothing the surface of the discharge nozzle plate for an inkjet recording apparatus which has been processed, and a chemical adsorption monomolecular film containing fluorine on the underlayer. A method of manufacturing a discharge nozzle plate for an inkjet recording apparatus, which comprises a step of forming. 3. The method for manufacturing an ejection nozzle plate for an ink jet recording apparatus according to claim 2, wherein the surface of the underlayer on which at least the monomolecular film is formed contains a hydroxyl group or an oxygen atom. 4. The method for manufacturing an ejection nozzle plate for an ink jet recording apparatus according to claim 2, wherein the underlayer is formed by applying polyimide. 5. A step of forming an underlayer on the surface of the discharge nozzle plate for an ink jet recording apparatus, which has been processed, for smoothing the surface, and containing a hydroxyl group or an oxygen atom on at least the surface of the underlayer. A method for manufacturing an ejection nozzle plate for an ink jet recording apparatus, comprising the steps of forming an intermediate layer and forming a chemisorption monomolecular film containing fluorine on the intermediate layer. 6. The method for manufacturing an ejection nozzle plate for an ink jet recording apparatus according to claim 5, wherein the underlayer is formed by applying polyimide. 7. The method for manufacturing an ejection nozzle plate for an inkjet recording apparatus according to claim 6, wherein the intermediate layer is a siloxane monomolecular film.