JPH07266553A - Ink jet recording head and manufacture thereof - Google Patents

Abstract

PURPOSE:To retain the pattern and the hydrophilicity stably of an ink channel by bonding a substrate and a diaphragm which are made of a polyimide molding resin by a polysulfone heat-sealing film and by forming inner walls by exposing them to an ink channel, a filter channel and an ink reservoir. CONSTITUTION:After a polysulfone solution dissolved by a solvent is applied to the sealing faces of a substrate 21 and a diaphragm 22 which are made of a polyimide molding resin, the solvent is evaporated and a polysulfone thin film 29 is formed on the laminated surface of the substrate 21 and the diaphragm 22 including the inner wall of a groove. Both are superposed and heated under load and the sealed sides are bonded airtightly by a polysulfone heat- sealing film 28. The solvent is delivered forcibly to a groove of an ink channel 1, filter channel 6, and an ink reservoir 7 which communicate with each other to dissolve and remove the polysulfone thin film 29. Thus after the polyimide molding resin is exposed to the inner walls of the ink channel 1, a hydrophilic treatment liquid is delivered to the channel add hydrophilicity and then an ink jet container 20 is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet type recording apparatus such as an ink jet type printing apparatus used for a computer output device or a color printer.

[0002]

2. Description of the Related Art FIG. 3 is a schematic plan view showing an ink flow path of a conventional ink jet recording head, and FIG. 4 is a schematic sectional view taken along a direction along an ink flow path of a conventional ink jet recording head. In the figure, a substrate 11 made of a glass plate, a Si wafer, a metal plate, or a plastic molded product is provided with an ink nozzle 2, a nozzle channel 3, an ink pressurizing chamber 4, and an ink supply channel which are formed as concave grooves communicating with each other. 5, a plurality of ink flow paths 1 and an ink reservoir 7 communicating with the ink flow path 6 via a backflow prevention filter flow path 6 are provided, and a vibration plate 12 made of the same material as the substrate 11 is provided on a seal surface 8 thereof. By airtightly joining or adhering, the seal
The ink jetting container 10 having a plurality of ink flow paths 1 defined by the filter surface 8 and the flow direction of the ink being regulated by the filter flow path 6 is formed. In addition, the ink ejection container 1
The common electrode 13 is formed as a vapor deposition film or a coating film across the plurality of ink pressurizing chambers 4 on the surface of the vibrating plate 12 facing the plurality of ink pressurizing chambers 0 of the common electrode 13. In the portion corresponding to the ink pressurizing chamber 4, one electrode 15A of the piezoelectric element 14 as an electro-mechanical conversion element is fixed by an extremely thin adhesive layer 16 so as to be in conductive contact with the common electrode 13, which is a so-called on-state. A demand type ink jet recording head is formed.

In the ink jet recording head 10 constructed as above, when a driving voltage is applied between the other electrode 15B of the piezoelectric element 14 and the common electrode 13, the piezoelectric element 14 expands and contracts in the thickness direction thereof, and the piezoelectric element 14 expands and contracts. When the ink is extended in the thickness direction, the vibrating plate 12 is deviated to the substrate 1 side, and the volume of the ink pressurizing chamber 4 is rapidly reduced, so that ink corresponding to the reduced volume is ejected from the ink nozzle 2, Droplets are deposited on the surface of the recording paper, and printing is performed with an ink density of an amount proportional to the magnitude of the driving voltage.

In the conventional ink jet recording head, in the ink jetting container 10 using glass or Si wafer for the substrate 11 and the vibrating plate 12, the ink nozzles 2, nozzle channels 3, inks formed as concave grooves communicating with each other. A plurality of ink flow paths 1 including the pressurizing chambers 4 and the ink supply paths 5 and an ink reservoir 7 communicating with the ink flow paths 6 for preventing backflow are formed by etching or machining, and a substrate 11 is formed. Further, there is known one including an ink jetting container 10 in which a vibration plate 12 is airtightly joined by electrostatic coupling. Also, in the case of an ink ejection container using plastic for the substrate and the diaphragm, a substrate having an ink flow path and an ink reservoir is manufactured as a plastic molded product by a molding process, and an adhesive is applied to the laminated surface with the diaphragm.
After drying, a method of heat-bonding the adhesive resin by heating to a predetermined temperature with a load applied to the laminated surface, or a method of heat-bonding the adhesive resin with a thin film adhesive sandwiched between the laminated surfaces Is known, and an ink jetting container using a metal plate as a substrate and a vibrating plate is also known that uses a similar bonding method.

[0005]

In a conventional ink jet recording head using a plastic molded product for the substrate 11, ink is ejected by using a molding resin suitable for easily and precisely molding the ink channel 1 having a delicate structure. The most important issue is to economically manufacture the container. At the same time, when the substrate 11 and the vibration plate 12 are heat-sealed with an adhesive resin in the manufacturing process, the substrate that is a molded product is heated. There is a problem that the ink flow path that is precisely molded due to the influence of deformation will be deformed, the glass transition point of the adhesive resin is lower than the heat deformation temperature of the molding resin used for the substrate, and the ink flow path due to heat fusion. Is required not to deform. In addition, in the conventional method in which an adhesive is applied to the laminated surface with the diaphragm and dried, and then the adhesive resin is heat-sealed by heating to a predetermined temperature with a load applied to the laminated surface. A thin film of adhesive resin adheres to the entire inner wall surface of the groove, such as a method of heat-sealing the adhesive resin with a thin film adhesive sandwiched between the laminated surfaces A state in which a thin film of an adhesive resin is attached to a part of the inner wall surface. However, the ink jetting container 10 that has completed the thermal fusion process is
In order to prevent ink from running out inside and improve ink circulation, an alkaline solution or the like is passed through the ink flow path 1 to perform hydrophilic treatment. Therefore, the alkaline solution including the adhesive resin, as well as the substrate and the diaphragm, is flushed. Hydrophilic treatment is performed. For this reason, the ink ejection container 10 is required to stably maintain the shape and hydrophilicity of the ink passage without the inner wall surface of the ink passage being attacked by the hydrophilic treatment liquid or the water-based ink.

An object of the present invention is to provide an ink jet recording head provided with an ink jetting container which is free from deformation of an ink flow path due to heat fusion treatment and can maintain ink flow performance without being affected by a hydrophilic treatment liquid or ink. And to provide a manufacturing method thereof.

[0007]

In order to solve the above-mentioned problems, according to the present invention, an ink nozzle formed as a groove communicating with each other, a plurality of ink flow paths including an ink pressurizing chamber, and the ink flow. A substrate including an ink reservoir communicating with a channel through a filter channel, and an ink ejection container including a vibration plate that is airtightly bonded to the surface of the substrate to define the plurality of ink channels The substrate and the diaphragm are made of a polyimide molding resin, which are airtightly adhered by a polysulfone heat-sealing film, and the polyimide molding is formed in an ink flow path, a filter flow path, and an ink reservoir, which are concave grooves communicating with each other. The substrate made of resin and the diaphragm are exposed to form the inner wall surface thereof.

It is assumed that the polyimide type molding resin is polyetherimide. A method of manufacturing an inkjet recording head is such that a polysulfone thin film is formed on a laminated surface of a substrate and a vibration plate on which an ink flow path, a filter flow path, an ink reservoir, and the like are formed in advance, and then a pressing load is applied to the laminated surface. A step of heat-sealing the thin film, and a step of forcibly flowing a solvent having compatibility with the polysulfone thin film to dissolve and remove the polysulfone thin film adhering to the ink channel, the filter channel, and the inner wall surface of the ink reservoir. Shall be included.

In the method of manufacturing an ink jet recording head, the solvent having compatibility with the polysulfone thin film is a mixed solvent of diethylene glycol dimethyl ether and ethanol.

[0010]

In the present invention, the substrate and the diaphragm of the ink jet container are made of polyimide type molding resin and are hermetically adhered by the polysulfone heat-sealing film, and the ink flow path and the filter flow path are formed by the concave grooves communicating with each other. Since the substrate and the diaphragm made of the polyimide type molding resin are exposed in the ink reservoir to form the inner wall surface thereof, the polyimide type molding resin, for example, polyetherimide, is excellent in moldability and can form an ink flow path. Precision molding is easy, and it has excellent acid and alkali resistance, withstands hydrophilic treatment with, for example, an alkaline solution, and its heat distortion temperature is 200 ° C or higher.
The temperature is higher than 0 ° C, and the heat fusion process can be performed without deforming the ink flow path. Therefore, the ink jetting container is formed by combining both of them, and at the same time, the substrate and the vibrating plate made of polyethylene imide are exposed to the ink flow passage, the filter flow passage, and the ink reservoir, so that the ink flow passage by the thermal fusion treatment is formed. It is possible to obtain an ink ejecting container that is not deformed and can maintain ink flow performance without being affected by the hydrophilic treatment liquid or ink.

In the method of manufacturing an ink jet recording head, a polysulfone thin film is formed on a laminated surface of a substrate and a vibration plate on which ink channels, filter channels, ink reservoirs and the like have been preformed, and then pressed on the laminated surfaces. Applying a load to heat-bond the polysulfone thin film, and forcibly flowing a solvent compatible with the polysulfone thin film to melt the polysulfone thin film adhering to the ink channel, filter channel, and the inner wall surface of the ink reservoir. If it is configured so as to include the step of removing, it is possible to obtain an ink jetting container which is free from deformation of the ink flow path due to the heat-sealing process and which can maintain the ink flow performance without being affected by the hydrophilic treatment liquid or the ink.

Further, by using a mixed solvent of diethylene glycol dimethyl ether and ethanol as a solvent for dissolving and removing the polysulfone thin film, the ink flow path can be obtained without affecting the substrate and the vibration plate made of the polyetherimide molded article. The function of dissolving and removing the polysulfone thin film adhering to the inner surface of the filter channel and the ink reservoir can be obtained.

[0013]

EXAMPLES The present invention will be described below based on examples. FIG. 1 is a cross-sectional view taken along the ink flow path showing a state after completion of heat fusion processing of an ink ejection container according to an embodiment of the present invention, and FIG. 2 is a completed ink ejection container according to an embodiment of the present invention. FIG. 4 is a cross-sectional view showing a state in a direction along an ink flow path, and the same components as those of the conventional art are denoted by the same reference numerals, and a duplicate description will be omitted. In the figure, a substrate 21 having an ink channel 1, a filter channel 6, and an ink reservoir 7 which are formed as concave grooves communicating with each other is formed as a polyethylene imide molded product as a polyimide type molding resin, and the same polyether imide is formed. The ink jet container 20 (semi-manufactured state) is formed by hermetically bonding the laminated surface with the vibration plate 22 formed as a molded product or a plate material by the polysulfone heat sealing film 28.

That is, the method of adhering the substrate 21 and the diaphragm 22 is as follows. A polysulfone solution dissolved in a solvent is applied to the seal surfaces 8 (see FIG. 3) of both the substrate 21 and the diaphragm 22 and then the solvent is evaporated. A polysulfone thin film 29 is formed on the laminated surface of the substrate 21 and the diaphragm 22 including the inner wall surface of the groove.
Then, the two are piled up, and the whole is crossed over the glass transition point of the polysulfone with the load applied to the seal surface and tightened.
The seal surface 8 is airtightly bonded by the polysulfone heat-sealing film 28 by heating for a short time to near ° C. As a result, no deformation of the ink flow path was observed, and it was found that the substrate and the vibration plate could be bonded airtightly and firmly by the polysulfone heat fusion film 28.

The semi-manufactured ink jet container 20 thus formed has diethylene glycol dimethyl ether in the ink flow passage 1, the filter flow passage 6, and the ink reservoir 7 which are formed as concave grooves communicating with each other. A mixed solvent of tellurium and ethanol is forced to flow for about 5 minutes using a pump to dissolve and remove the polysulfone thin film 29, and the polyetherimide is exposed on the inner wall surface 27 of the ink flow path as shown in FIG. After that, for example, an alkaline solution as a hydrophilic treatment liquid is caused to flow through the channel to perform hydrophilic treatment, thereby completing the ink ejection container 30.

The ink jet container 30 thus manufactured was filled with water-based ink, and the state of the ink flow path 1, the filter flow path 6, and the inner wall surface 27 of the ink reservoir 7 was observed after 100 hours. No abnormality was found on the surface of the flow channel, and it was confirmed that there was no abnormality such as ink shortage even in the ejection test in which the ink was ejected from the ink nozzle 2, and the hydrophilicity was maintained. Further, no damage or peeling of the polysulfone thermal fusion film 28 was observed in this test, and it was confirmed that the airtightness of the flow channel was maintained.

Incidentally, the ink jet container 2 in a semi-manufactured state
When 0 was subjected to a hydrophilic treatment and further filled with a water-based ink and the same test as above, abnormalities such as deformation, peeling, nozzle clogging of the polysulfone thin film were observed. From the above examination results, after the substrate and the vibration plate are bonded by the polysulfone heat-fusion film, a solvent compatible with the polysulfone thin film, for example, diethylene glycol dimethyl ether.
By dissolving and removing the polysulfone thin film adhering to the channel with a mixed solvent of tellurium and ethanol, thereafter,
It was demonstrated that an ink jet container for an ink jet recording head having excellent ink jetting performance can be provided without being affected by a hydrophilic treatment liquid or a water-based ink.

[0018]

As described above, according to the present invention, a polyimide type molding resin such as polyether imide is used for the substrate and the vibrating plate of the ink jet container, both of which are hermetically bonded by the polysulfone heat-sealing film and communicate with each other. A solvent having compatibility with polysulfone is caused to flow through the ink flow path, the filter flow path, and the ink reservoir, which are formed by the recessed groove to dissolve and remove the polysulfone thin film, and the ink is ejected from the inkjet recording head so that the substrate and the vibration plate are exposed. A container and a method for manufacturing the container were configured. As a result, it is possible to easily perform precision molding of the ink flow path and perform heat fusion processing without deforming the ink flow path, and at the same time, an ink that can maintain the ink flow performance without being affected by the hydrophilic processing liquid or the ink. An inkjet recording head provided with a jetting container can be economically and advantageously provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the ink flow path showing a state after completion of heat fusion processing of an ink ejection container according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the ink flow path showing a completed state of the ink ejection container according to the embodiment of the present invention.

FIG. 3 is a plan view schematically showing an ink flow path of a conventional inkjet recording head.

FIG. 4 is a schematic cross-sectional view of a conventional inkjet recording head in a direction along an ink flow path.

[Explanation of symbols]

 1 Ink Flow Path 2 Ink Nozzle 3 Nozzle Flow Path 4 Ink Pressurizing Chamber 5 Ink Supply Path 6 Filter Flow Path 7 Ink Reservoir 8 Seal Surface (Lamination Surface) 9 Adhesive Resin Thin Film 10 Ink Jet Container 11 Substrate 12 Vibration Plate 13 Common electrode 14 Piezoelectric element 15 Electrode of piezoelectric element 16 Adhesive layer 20 Ink jet container (semi-manufactured state) 21 Substrate (polyetherimide molded product) 22 Vibrating plate (polyetherimide molded product) 27 Polyetherimide exposed Wall surface 28 Polysulfone heat sealing film 29 Polysulfone thin film 30 Ink jetting container (completed state)

Claims (4)

[Claims] 1. A substrate having an ink nozzle formed as a recessed groove communicating with each other, a plurality of ink channels including an ink pressurizing chamber, an ink reservoir communicating with the ink channel via a filter channel, and A substrate provided with an ink jetting container composed of a vibration plate that is airtightly adhered to the surface of the substrate to define the plurality of ink flow paths, wherein the substrate and the vibration plate are made of polyimide type molding resin, and polysulfone heat fusion is used. The substrate and the vibrating plate made of the polyimide type molding resin are exposed in the ink channel, the filter channel, and the ink reservoir which are airtightly adhered by the film and communicate with each other to form the inner wall surface thereof. An inkjet recording head characterized by the following. 2. The ink jet recording head according to claim 1, wherein the polyimide type molding resin is polyether imide. 3. A polysulfone thin film is formed on a laminated surface of a substrate and a vibration plate on which an ink flow path, a filter flow path, an ink reservoir, and the like are formed in advance, and a pressing load is applied to the laminated surface to heat the polysulfone thin film. A step of fusing and a step of forcibly flowing a solvent having compatibility with the polysulfone thin film to dissolve and remove the polysulfone thin film adhering to the ink channel, the filter channel, and the inner wall surface of the ink reservoir. The method for manufacturing an ink jet recording head according to claim 1 or 2, wherein: 4. A method of manufacturing an ink jet recording head according to claim 3, wherein the solvent having compatibility with the polysulfone thin film is a mixed solvent of diethylene glycol dimethyl ether and ethanol.