JPH1158751A - Production method of ink-jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparent mono-coque structure by bonding a vibrating member and a molded product with an adhesive prepared by dissolving with a solvent a material the same as the material of the vibrating member and the molded product produced by molding a thermosetting resin so as to provide a homogeneous physical property to the bonded layers similar to that of an integrally-molded product. SOLUTION: In bonding and fixing a resin molded product 1 on the nozzle side of an ink-jet head and a resin molded product 2 on the ink room side, an adhesive is prepared by dissolving a material the same as the material for producing the molded product with a solvent (an optimum solvent is used according to the material of the resin). By applying the adhesive as bonded layers 1a, 2a, the bonding operation can be completed. Then, by the baking treatment of the resin molded product after completing the bonding operation in a furnace with an inert gas atmosphere, the entirety including the bonded layers can be amorphous. Accordingly, an amorphous carbon head having a mono-cock structure with the excellent performance, with the bonded layers sufficiently durable with the ink, can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a head used in an ink jet printer.

[0002]

2. Description of the Related Art Ink jet heads use ink 1
Since the ejection amount of the droplet is as small as about 30 pl to 100 pl, the ink chamber for holding the ink liquid volume is necessarily a small liquid chamber.

Conventionally, the nozzle section including the ink chamber is constituted by a plurality of pieces, and these have been manufactured by resin molding and joining with an adhesive. Alternatively, the entire nozzle portion has been integrally formed.

[0004]

In the conventional technique for bonding resin molded articles, the bonding between the resin molded articles is made by an ordinary adhesive (a material different from the material of the molded article), that is, by an expert maker as an adhesive. It was common to join using an adhesive. However, when an integrated head is formed by bonding and fixing two or more pieces with a complicated structure such as an ink jet head, since the characteristics of the adhesive layer portion are different from the characteristics of the resin molded product, In the adhesive strength, there was a high possibility that various problems such as peeling, difference in thermal expansion, uneven coating of the adhesive, and protrusion would occur.

[0005] Alternatively, sheet bonding using a sheet-like adhesive may be performed as a typical method of fine joining of resin molded products, but the sheet adhesive may cause problems such as ink resistance. was there.

On the other hand, conventional integral molding (monocoque structure)
In general, a molding method typified by injection molding or blow molding is used for the head, but it cannot be applied to a case where a fine and complicated head is manufactured.

In an ink jet head obtained by joining a plurality of resin moldings, in a fine and complicated structure, it is an essential condition that the adhesive layer portion of the ink chamber has a completely closed structure. . Therefore, in the present invention, by eliminating the above-mentioned disadvantages due to the adhesion between the resin molded products, by giving the adhesive layer the same physical properties as when the adhesive layer is also integrally molded, apparently a monocoque ink jet structure It is an object to manufacture a head.

[0008]

In the case where a liquid, gas, or solid substance is stored or brought into contact with the ink jet head prepared as described above, and the resin molded article is eroded by the substance, By firing the molded product, it is turned into amorphous carbon to form a container that can be completely enclosed. In addition, when the bonding is performed, the bonding layer can also be made into amorphous carbon to form a monocoque structure.

In the present invention, the adhesive used in the bonding operation is made of the same material as that used for forming the molded article, melted with a solvent, and sprayed on the bonding surface in a trace amount uniformly by various methods, or by spin coating. .

Alternatively, carbon and carbon compounds are removed by a chemical treatment, a plasma asher, a method of bombarding with oxygen while applying ultraviolet rays, and the surface is activated and roughened. Do.

[0011] By performing such bonding, it is possible to form the material by bonding the same material to the molding material, so that even a complicated shape can be easily made into the same thing as the one integrally formed. .

By doing so, when the molded portion is made amorphous by firing, the adhesive portion is also made of the same material, so that a monocoque structure can be integrated even if it becomes amorphous.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows a resin molded product (hereinafter referred to as a nozzle molded product) 1 on the nozzle side of an ink jet head.
FIG. 2 shows a resin molded article 2 on the ink chamber side (hereinafter, referred to as an ink chamber molded article). FIG. 3 shows a state in which the nozzle-side molded product 1 and the ink chamber-side molded product 2 of the ink jet head are bonded.

When the complex and fine resin molded product prepared in FIGS. 1 and 2 is bonded and fixed as shown in FIG. 3, the adhesive used for the bonding is made of the same material as that used for forming the molded product. Dissolve it with a solvent (use the most suitable solvent depending on the resin material) and apply this adhesive to the adhesive layer 1
a, 2a to complete the bonding. In addition, since a method of applying an appropriate amount of the adhesive is conventionally known to be performed by a method such as spin coating or silk printing, it is possible to appropriately use the method appropriately.

As a special method, low-temperature molding into a sheet shape can be used as an adhesive.

In the bonding of the present invention, the bonding margin of the resin molded product is 50 μm to 100 μm at the minimum part of the partition wall of the ink chamber.
The adhesive is very narrow, so the thickness of the adhesive is thin and 3 μm to 15 μm
When the adhesive is applied to such a degree, the desired adhesive strength can be obtained without excess adhesive protruding.

It was also found that stronger bonding can be achieved by activating the side coated with the adhesive with a plasma asher and a chemical treatment when implementing the bonding method of the present invention.

Further, the same material as that of the resin molded product is pulverized to form fine particles, and the powder is bonded to the bonding surface by using the principle of electrostatic coating, and is melted by applying heat and pressure during bonding. Bonding method may be used.

Alternatively, when finely pulverizing the same material as the material of the resin molded product, a resin melted with a highly volatile liquid is atomized from a nozzle used for atomizing the liquid, sprayed, and directly radiated to the bonding surface. , Are formed into fine particles and adhere to the bonding surface.
When the joining member is pressed against this surface and heated, the fine particles melt and work as an adhesive.

Still another method is as follows.
When the adhesive layers 1a and 2a are selectively activated by masking their surface portions with a plasma asher, the adhesive layers are melted and bonded together when the surfaces are pressed and heated.

As still another method, the same effect can be obtained by irradiating ultraviolet rays instead of the plasma asher and applying oxygen. Similar effects can be obtained by chemical treatment (solvent, strong acid, alkali, etc).

That is, a molding resin that has not progressed in cross-linking is molded to form a resin molded product, and then the adhesive layer is activated by a chemical treatment and a physical treatment as described above. When the state is returned and the temperature is increased again, the treated adhesive layer once again melts and adheres.
By doing so, the bonding width of the ink chamber 2b of the complicated and very small ink jet head is reduced to 50.
It is possible to perform defect-free bonding very accurately even though there is only an adhesive width of μm to 100 μm, despite the fact that adhesive is protruding, shortage of adhesive, and various problems caused by uneven coating are likely to occur. Will be possible.

Next, when the resin molded product after completion of the above-mentioned bonding is put into a furnace for baking and subjected to a baking treatment in an inert gas atmosphere, all the parts including the bonding layer become amorphous. Therefore, it is possible to produce an amorphous carbon head having a monocoque structure having a very good performance that the adhesive layer can sufficiently withstand the ink.

FIG. 4 shows an ink chamber manufactured by the above-described manufacturing method, in which an actuator 3 of a piezoelectric element, a power supply circuit 4 for driving the actuator 3, an ink channel 6 as a holder, an ink tube connector and a filter 7 are provided. And the like, and shows a state of being assembled to the ink jet head.

FIG. 5 schematically illustrates the relationship between the temperature of a material (resin pellet) used as a molding resin and crosslinking.

The resin pellets, which have not undergone crosslinking before molding, are at point A, and heat is applied to the resin pellets to form a gel before molding. Even after the completion of molding, it can be heated and solidified to be in a state in which crosslinking has progressed as a solid. After that, the resin pellets are melted with a volatile solvent as an adhesive layer, or activated as described above, and returned to a state close to the point A and heated.
By applying pressure, only the activated adhesive layer becomes a gel or a liquid, melts, and is compatible with and adheres to the molded adhesive layer.

Even if the above-mentioned processing is applied to a part which is not desired to be bonded, the part which is not pressed is not bonded. That is, even if heat is applied to the activated portion to restore the adhesive ability, if the members to be joined are not pressed against each other at this point, crosslinking proceeds and the material is integrated with the molded product, so that there is no foreign matter. This means
Because of the superior point of this bonding method, the adhesive does not protrude, so that it is the optimum bonding method for very fine bonding.

As described above, according to the present invention, it is possible to improve the situation in which the desired performance cannot be obtained because the adhesive was made of a different material from the resin molded product. It has become possible to make the head sufficiently satisfactory as in the case of a monocoque structure.

The ink jet head has been described as an example of the present invention. However, this technique has versatility and can be applied to other technical fields.

[0031]

According to the structure of the present invention, since the resin molded product of the ink jet head and the adhesive layer are made of the same material, they can be finished in the same manner as the integrally molded product. For that reason,
Even if it is a box-shaped and complicated shape that could not be industrially formed by conventional molding, a molded product having the same characteristics as those of integral molding can be obtained. Therefore, the obtained business effect is very large.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a resin molded product on the nozzle side of an inkjet head according to the present invention.

FIG. 2 is a cross-sectional view of a resin molded product on the ink chamber side of the inkjet head of the present invention.

FIG. 3 is a cross-sectional view when the resin molded products of FIGS. 1 and 2 are bonded.

FIG. 4 is a cross-sectional view of an inkjet head assembly.

FIG. 5 is a graph showing the relationship between resin temperature and crosslinking.

[Explanation of symbols]

Reference numerals 1 and 2 denote resin molded products, 1a and 2a denote adhesive layers, 3 denotes an actuator, 4 denotes an electrode circuit, 6 denotes an ink flow path, and 7 denotes a filter.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Jun Nagata 1060 Takeda, Hitachinaka-shi, Ibaraki Prefecture Within Hitachi Koki Co., Ltd.

Claims (5)

[Claims] A vibration mode of a piezoelectric element is transmitted to a pressure chamber via a vibration member. The pressure chamber has a plurality of nozzles and a number of pressure chambers corresponding to the nozzles. In the ink-jet head formed by the product, the vibrating member and the molded product are molded with a thermosetting resin,
A method for manufacturing an ink jet head, comprising: bonding a vibrating member and a molded product with an adhesive obtained by dissolving the same material as a material with a solvent. 2. The method for manufacturing an ink jet head according to claim 1, wherein the adhesive is obtained by pulverizing the same material as the vibration member and the molded product, and the adhesive is applied by electrostatic coating. A method for manufacturing an ink jet head, comprising: adhering to a bonding surface with a vibrating member and a molded product. 3. The method for manufacturing an ink jet head according to claim 1, wherein the adhesive is applied to the vibration member and the molded product by a method such as spin coating, silk printing, and transfer. Head manufacturing method. 4. The method for manufacturing an ink jet head according to claim 1, wherein the solvent has volatility. 5. The method for manufacturing an ink jet head according to claim 1, wherein the adhesive is formed in a sheet shape.