JPH0768794A - Inkjet resin filter, method for manufacturing the filter, inkjet head, and method for manufacturing the head - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a filter capable of integrally forming with precision the structural members of various structures even in the case of complicated structures or minute structures. And an improved ink jet head having a filter in which a large number of holes are formed in a cured resin layer, the holes being in communication so that liquid can pass through the resin layer, and An object is to provide a method for manufacturing an inkjet head. [Structure] A filter is a filter used for filtering a liquid, in which a large number of pores based on microballoons are formed in a cured active energy curable resin layer, and the large number of pores are filled with a liquid. It is connected so that it can pass through the resin layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin filter which is particularly suitable for use in an ink jet device that ejects ink droplets to print image information on a recording medium, a method for producing the filter, an ink jet head, and the ink jet head. The present invention relates to a method of manufacturing a head.

[0002]

2. Description of the Related Art Ink jet printing technology prints characters and images on a print medium such as paper, cloth, and plastic sheet by ejecting ink from fine nozzles. Conventionally, an ink jet device having such an ink jet print type ink jet head is provided in a printer as an output terminal of a copying machine, a facsimile, a word processor, a workstation, a personal computer, a host computer, an optical disk device, a video device, or the like. It is used as a handy type or portable type printer in these information processing systems.

The general construction of an ink jet head applied to the ink jet printing system is a discharge port for discharging ink, a liquid chamber for storing ink to be supplied to this discharge port, a discharge port and a liquid chamber. An ink flow path communicating with the ink flow path, an energy generation element provided in a part of the ink flow path and generating energy for ejecting ink, and an ink supply port for supplying ink to the liquid chamber from outside the head. Consists of. Then, the ink is supplied to the inkjet head from the ink tank through the ink supply means. An ink filter is provided between the ink supply unit and the ink supply port or between the ink supply unit and the ink tank, and the ink supplied from the ink tank to the inkjet head passes through the filter. Flow into the discharge nozzle.

The filter used here is required to perform the following functions. That is, 1) it is possible to prevent nozzle clogging due to contamination such as dust contained in ink or ink lumps, and to prevent ejection failure and deviation in the ejection direction, and 2) air in the liquid chamber. To prevent unstable discharge due to decrease in discharge energy.

The position where this filter is provided in the ink jet head is the nozzle (ejection port) as much as possible.
It is preferable to install it close to. This is because when the filter is provided in the upstream portion of the ink supply system, the ink in the ink tank can be filtered, but air may be mixed between the filter and the nozzle (ejection port). Further, it is preferable that the flow resistance of the filter is as small as possible. The reason for this is that, particularly when the inkjet head is driven at high speed, if the flow resistance increases, the refill speed of the ink decreases, which affects high-speed driving.

Conventionally, the filter in the ink jet apparatus is composed of ceramic, thin tube, mesh, fiber, plastic sintered body or the like. It is usually difficult to provide a filter made of these materials in a complicated portion in the ink jet head, so that the filter installation portion is purposely provided to install the filter there.

Typical examples of such installation locations include the contact portion between the top plate of the ink jet head and the ink supply tube, and the tip of the ink supply tube.

[0008]

However, in either case, the installation area of the filter is governed by the size of the ink supply port provided in the ink jet head, and generally cannot be made too large. Therefore, it is necessary to make the performance of the filter more severe so that the filter can fulfill the above-mentioned purpose in a limited small area. Further, when the filter is fixed to the filter installation portion thus provided, a method of fixing the filter to the inkjet head with an adhesive or by welding with ultrasonic waves or heat is used. However, there are problems in either case. That is, when fixing with an adhesive, if the amount of the adhesive is large, the filter may be clogged, and if the amount is small, the adhesive force may be insufficient. Further, in the case of fixing by means of the above-mentioned welding, there is a problem that the place where the filter is installed needs to have a shape that facilitates welding, and there is a restriction on the material of the filter installation portion of the inkjet head.

Further, it is known to use a filter made of a sintered body or the like. In this case, although the above problem does not occur when fixing the filter, the flow resistance is difficult to predict. In addition, there is a problem that the head needs to be exposed to a high temperature range during sintering, which may adversely affect the ink flow path.

For this reason, the filter used for the ink jet head has the above-mentioned problems because it is separately prepared and fixed, and it requires considerable skill to accurately install the filter in the vicinity of the discharge port. There is a problem.

Therefore, the present invention has been made in view of the above problems of the prior art, and as a result of intensive research conducted by the present inventors in order to solve the above problems, a conventionally unknown filter has been obtained. . A main object of the present invention is to provide a filter that can accurately form integrally with the structural members of these structures even in the case of complicated structures or fine structures such as various devices.

Another object of the present invention is to provide a filter in which a large number of holes are formed in a cured resin layer, and the holes communicate with each other so that a liquid can pass through the resin layer. It is an object of the present invention to provide an improved inkjet head provided with the above, and a method for manufacturing the inkjet head.

[0013]

In order to solve the above-mentioned problems, a filter according to the present invention is a filter used for filtering a liquid, which is based on microballoons in a cured active energy curable resin layer. A large number of holes are formed, and the plurality of holes are communicated so that liquid can pass through the resin layer.

Preferably, the voids are formed by microballoons having a core containing a substance that vaporizes and expands at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component.

Preferably, the material constituting the core comprises a component selected from the group consisting of isobutane and isobutylene.

Preferably, the thermoplastic resin is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer. The main component is at least one component.

Preferably, the active energy curable resin is a curable resin which is cured by heat or light.

Preferably, the filter has a thickness parallel to the liquid supply direction of 5 times or more the diameter of the hole, and preferably the filter is used as a part of an ink supply path of an ink jet device.

Next, the ink jet head according to the present invention has an ejection port for ejecting ink, a heat generating resistor for generating thermal energy for ejecting ink from the ejection port, and an electrical connection to the heat generating resistor. An ink jet head substrate on which an electrothermal converter having a wire connected to supply an electric signal for generating the thermal energy to the heating resistor is arranged, and an ink supply system for supplying ink. An ink jet head having a plurality of pores is formed in a cured resin layer in a part of the ink supply system, and the pores communicate with each other so that liquid can pass through the resin layer. It is characterized by providing a filter.

Preferably, the pores are formed by microballoons having a core containing a substance which vaporizes and expands at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component.

[0021] Preferably, the material constituting the core comprises a component selected from the group consisting of isobutane and isobutylene.

Preferably, the thermoplastic resin is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer. The main component is at least one component.

[0023] Preferably, the active energy curable resin is a curable resin that is cured by heat or light.

Preferably, the pores have an average diameter of 30 μm.
It is the following.

Preferably, the filter has a thickness parallel to the ink supply direction of 5 times or more the diameter of the hole.

The method of manufacturing a filter according to the present invention is as follows:
A method for producing a filter for filtering a liquid, comprising forming a dispersion in which a large number of microballoons encapsulated in a shell composed of a resin soluble in a solvent is dispersed in an active energy curable resin, The dispersion is heat-treated to expand each of the microballoons, then the active energy curable resin is cured, and the dispersion is treated with a solvent having a selective solubility only for each shell of the microballoons. , The shells of the microballoons are removed so that the pores of the microballoons can communicate with each other.

[0027] Preferably, the microballoon has, as a core, a shell containing a thermoplastic resin as a main component, and a substance that vaporizes and expands at a temperature higher than room temperature.

Preferably, the material comprising the core is selected from the group consisting of isobutane and isobutylene.

Preferably, the thermoplastic resin is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer. The main component is at least one component.

Preferably, the active energy curable resin is a curable resin that is cured by heat or light.

Preferably, in the filter, the thickness parallel to the liquid supply direction is 5 times or more the diameter of the hole.

Preferably, the content of the microballoons in the active energy curable resin is 20 to 90 wt.
%.

Preferably, the solvent having the selective solubility is selected from the group consisting of acetone and dimethylformamide.

Preferably, the filter is used as a part of the ink supply path of the ink jet device.

The method of manufacturing an ink jet head according to the present invention is a method of manufacturing an ink jet head, comprising: a) a heating resistor for generating thermal energy for ejecting ink and the heating resistor. A step of forming an ink jet head substrate in which an electrothermal converter electrically connected to the body and having a wiring for supplying an electric signal for generating the thermal energy to the heating resistor is arranged; B) a step of providing a removable solid layer on a portion of the substrate corresponding to an ink flow path system including an ink ejection port, an ink flow path, an ink common liquid chamber, and an ink supply port, and c) the substrate and the above Laminating a coating material for coating the solid layer, d) removing the solid layer to form an ink flow path system, and e) forming the ink flow path. Forming a layer composed of a dispersion in which a large number of microballoons which are encapsulated in a shell composed of a resin soluble in a solvent in at least a part are dispersed in an active energy curable (heat or photocurable) resin, f) heat treating the layer formed in step e) to expand each of the microballoons and then cure the active energy curable resin, and g) selecting only for each shell of the microballoons. A filter is formed by treating the dispersion layer treated in the above f) with a solvent having solubility to remove the shells of the microballoons so that the pores of the microballoons communicate with each other. To do.

Preferably, the microballoon has, as a core, a substance which vaporizes and expands at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component.

Preferably, the material used for the core comprises a component selected from the group consisting of isobutane and isobutylene.

Preferably, the thermoplastic resin is selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymers, acrylonitrile-vinyl chloride copolymers and vinyl acetate-vinyl chloride copolymers. The main component is at least one component.

[0039] Preferably, the active energy curable resin is a curable resin which is cured by heat or light.

Preferably, in the filter, the thickness parallel to the liquid supply direction is 5 times or more the diameter of the hole.

Preferably, the content of the microballoons in the active energy curable resin is 20 to 90 wt.
%.

Preferably, the solvent having the selective solubility is selected from the group consisting of acetone and dimethylformaldehyde.

According to the manufacturing method of the present invention, a high quality ink jet head can be produced with high yield, high productivity and high accuracy.
And it can be manufactured relatively inexpensively.

The present invention can be effectively applied not only to black monochrome ink jet heads but also to complex color ink jet heads, serial scan type ink jet heads, and full line type ink jet heads. The color inkjet head or the full line type inkjet head described above is effective regardless of whether it is configured by combining a plurality of inkjet heads or one inkjet head integrally formed. Is.

The filter of the present invention can be suitably used not only in the inkjet head but also in other parts of the ink supply path in the inkjet device.

[0046]

FUNCTION AND EXAMPLE The filter of the present invention and the method for manufacturing the filter will be described below.

The filter of the present invention comprises microcapsules (hereinafter referred to as microballoons or microspheres) consisting of a shell containing a thermoplastic resin as a main component, and a core mainly containing a component that expands / vaporizes when heated at a temperature higher than room temperature. Is dispersed in a heat- or photo-curable resin (that is, a binder resin), and has a filter eye formed by a large number of pores formed by these microballoons.

The microballoon will be described.
The volume of this microballoon expands by heating, and microhollow spheres are formed in the microballoon. That is, from the start of foaming (vaporization) of the core component, the shell completely expands by heating, and the maximum volume obtained will remain as it is if it is immediately returned to room temperature, but the volume will decrease if heated continuously. Have As described above, the microballoon used in the present invention is composed of a shell containing a thermoplastic resin as a main component and a core mainly composed of a component that expands / vaporizes when heated at a temperature higher than room temperature. As the thermoplastic resin that becomes the shell,
Based on at least one component selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer. Is preferred. It is necessary that the core is vaporized at a temperature slightly higher than room temperature and the vaporized gas does not affect the curable resin. Therefore, the core is preferably composed of a component selected from the group consisting of isobutane and isobutylene. Such microballoons are commercially available, and among them, for example, Expancel 551DU (trade name:
Preferred are those manufactured by Expancel Co., Ltd. of Sweden.

The filter of the present invention forms a porous (porous) resin cured product by utilizing the pores provided by such microballoons, and uses this as a filter. In the filter of the present invention, since the binder resin itself has adhesiveness, it is not necessary to use an adhesive when installing the filter, and therefore the problem of filter clogging seen in the prior art does not occur. Further, it is not necessary to perform welding or the like when installing the filter, and the filter is not affected by the installation location or shape. Furthermore, since the filter material for forming the filter (that is, the dispersion composed of the microballoons and the binder resin is liquid when uncured, it is possible to handle fine parts and complicated shapes, the filter can be installed until now. It enables the formation of a suitable filter even in a place where it has not been formed, and the formed filter has a performance comparable to that of the conventional filter.

As the binder resin used to disperse the microballoons, a curable resin which is cured by activation energy (light or heat) is used as described above. Examples of such a curable resin include a thermosetting resin and a photocurable resin. Specific examples thereof include epoxy resin, acrylic resin, diglycol dialkyl carbonate resin, unsaturated polyester resin, polyurethane resin, polyimide resin, melamine resin, phenol resin, urea resin and the like. Above all, as the thermosetting resin, an epoxy resin, for example, Oder SY
25 (trade name: manufactured by Tokyo Ohka Co., Ltd.) is preferable, and the photocurable resin is an acrylic resin such as Nitron T8.
Resins such as 526 (trade name: manufactured by Nitto Denko Corporation) are preferable.

In the filter of the present invention, the flow resistance of the filter is mainly determined by the holes formed by the microballoons. That is, the flow resistance of the filter can be controlled by adjusting the diameter of the pores (fine hollow spheres) formed by the microballoons and the content ratio of the microballoons to the binder resin. Regarding the control of the diameter of the pores, 1) a method of controlling the heating temperature by utilizing the properties of the microcapsules described above to make the volume of the microballoon a desired size, and 2) an unexpanded microballoon. There is a method of setting the diameter of the core to a desired value. Since there is a limit to the expansion of the core diameter due to heating, it is preferable to employ the above methods 1) and 2) in combination as appropriate so that the pores have a desired diameter.

By the way, in order for the binder resin (heat or photocurable resin) containing the microballoons to function as a filter, it is necessary that the pores formed by the microballoons communicate with each other. In order to connect the pores to each other, it is necessary to elute the shell (thermoplastic resin) of the microballoon with a solvent after curing the binder resin. Here, the solvent used must be one that selectively elutes only the shell without affecting the binder resin after curing. As such, preferred solvents to be used include acetone and dimethylformamide (DMF). Of course, in addition to this condition, it is necessary that each microballoon is in contact. This condition can be satisfied by the same means as the above-described flow resistance control.

The content of the microballoons in the dispersion made of the binder resin in which the above microballoons are dispersed to form a filter is preferably in the range of 20 to 90 wt%. When the content of the microballoons in the dispersion is less than the lower limit of the above range, the microballoons may not sufficiently contact with each other, and the obtained product may not function as a filter. On the other hand, when the content of the microballoons in the dispersion exceeds the upper limit of the above range, the strength of the obtained filter itself may be lowered and the desired flow resistance may not be maintained. Further, in order to make the mutual contact of the microballoons sufficient, it is necessary to set the heat treatment temperature of the dispersion to be relatively high, but in this case, the binder resin may be adversely affected. When obtaining a desired filter, it is necessary to pay attention to these points and set the optimum conditions.

By the way, in the ink jet head, the filter is used mainly for the purpose of preventing clogging of the ejection port for ejecting ink due to dust or the like, but the ejection port of the inkjet head is generally used. Since the diameter is about 25 to 50 μm, basically, it is only necessary to remove dust larger than this value with a filter. Therefore, the dust to be removed by the filter in the inkjet head is 30 to 50 μm.
It is assumed that the diameter is m. From this viewpoint, the diameter of the pores (micro hollow spheres) formed by the microballoons is also 30μ.
It is preferably m or less. Furthermore, in the inkjet head, in reality, a plurality of dust particles may cause the ejection port to be clogged, resulting in ejection failure.In order to prevent the occurrence of this problem, in the case of the conventional mesh filter used in the inkjet head, 8-15μ
A hole diameter of m is used. However, generally, the smaller the hole diameter, the higher the flow resistance of the filter. In the inkjet head,
The flow resistance including the filter is 200 mmAq in terms of hydraulic head pressure.
It is said that normal ink ejection cannot be performed when the above is reached. Further, when printing at a high speed, it is necessary to increase the ink supply efficiency, and therefore it is preferable to lower the flow resistance of the filter as much as possible. In the filter of the present invention, the thickness of the filter in the direction parallel to the ink supply direction (in the ink flow path) is set so that dust in the ink can be sufficiently removed without reducing the pore size formed. When provided, the thickness in the direction along the flow path) is preferably 5 times or more the diameter of the holes formed by the microballoons.

Next, a method for manufacturing the filter of the present invention will be described with reference to FIGS. 1 (A) to 1 (C).

FIG. 1A is a schematic cross-sectional view of a layer composed of a dispersion of microballoons dispersed in a binder resin. FIG. 1B is a schematic cross-sectional view of the dispersion layer shown in FIG. 1A in a state where the dispersion layer is heat-treated to vaporize the core component of the microballoon and the shell resin is expanded. FIG. 1C is a schematic cross-sectional view showing a state in which the dispersion layer shown in FIG. 1B is subjected to an etching treatment using a selective solvent to dissolve the shell resin so that the microballoon pores are communicated with each other. It is a figure.

In manufacturing the filter of the present invention, first, as shown in FIG. 1A, microballoons 52 (consisting of a core component and a shell) are dispersed in a curable resin 51 which is a binder resin. This dispersion can be performed with a generally used homogenizer or the like. The curable resin dispersion containing microballoons is heated to an appropriate temperature so that the microballoons have a desired size. In the heated microballoon, the vaporizable component of the core 53 is vaporized by heating and expands as shown in FIG. 1 (B). For example, when the above-mentioned EXPANCEL 551DU (trade name: manufactured by EXPANCEL Co., Ltd.) is used for the microballoon 52 and heated to 120 ° C., the microballoon having an average particle size of 7 μm before heating is expanded by heating. The diameter expands to about 20 μm. After that, if the microballoon is returned to room temperature as it is, the thermoplastic resin 54 as the shell is rapidly cooled and cured again, so that the diameter when expanded is maintained.

Next, the binder resin 54 is cured with the microballoons inflated in this manner. When the curable resin as the binder resin is a thermosetting type resin, the binder resin may be cured when the microballoons are expanded. Therefore, it is necessary that the binder resin is uncured when the microballoon is expanded, and the binder resin is cured after the microballoon is expanded to a desired state.

As described above, the inventors of the present invention under the conditions that the binder resin is cured after the microballoons are expanded to a desired state, the present inventors have found that the energy amount that causes the microballoons to expand and the energy amount that causes the binder resin to harden. I focused on and examined. As a result, the following was revealed. That is, the condition for the thermosetting resin as the binder resin to cure is that a certain amount of energy is applied. On the other hand, regarding the expansion of the microballoon, its diameter depends on the maximum energy amount applied. Is determined. Therefore, by rapidly heating the microballoon-containing thermosetting resin to an appropriate temperature for the microballoons to expand to a desired diameter,
The microballoons can be inflated before the thermosetting resin cures. On the other hand, when the binder resin is a photo-curing type resin, it does not cure by heating, so that control of the heating method is not particularly necessary, and curing by light irradiation may be performed after the expansion process of the microballoons. The diameter of the microballoon can be easily controlled.

After the curing of the binder resin is completed, the cured shell resin is eluted with a solvent such as acetone to form pores 55 by microballoons and the formation of the filter is completed (FIG. 1 (C)). )reference).

Although the unexpanded microballoons are dispersed in the binder resin in the above method, the already expanded microballoons may be dispersed in the binder resin. In this case, even if the binder resin is thermosetting, a good filter can be produced by curing the binder resin at low temperature for a long time. When it is desired to increase the content rate of the microballoons contained in the binder resin, it is preferable to disperse the microballoons in an unexpanded state.

Further, the dispersion obtained by dispersing microballoons in the binder resin used in the present invention is liquid in the uncured state, and thus can be provided by a method such as coating or injection. This dispersion layer forming step is
It suffices if it is before the binder resin is cured. That is, the heating process of the microballoon may be performed after forming the dispersion layer or before forming the dispersion layer.

The experiment conducted by the present inventors for completing the filter of the present invention will be described below.

<Experiment 1> In this experiment, as a binder resin, a photosensitive resist, Oder SY25 (trade name:
(Tokyo Ohka Co., Ltd.) was used as a base, and 50 wt% of non-expanded microballoons EXPANCEL 551DU (trade name: made by EXPANCEL Co., Ltd.) was added thereto and homogenized by a homogenizer to obtain a dispersion. . This dispersion is cured by laminating a positive resist on a glass substrate.
Screen printing was performed on the solubilized product to form a dispersion layer, followed by drying at 60 ° C. for 2 hours. The thickness of the dispersion layer after drying was 100 μ ± 10 μm, and no adverse effects due to the addition of 50 wt% of microballoons (peeling during printing, film thickness accuracy, printing bleeding, etc.) were observed. Next, the dried dispersion layer was heated to 120 ° C. At this time, the microballoons in the dispersion layer began to expand, and after 3 minutes, the dispersion layer reached a film thickness of 180 μm. This gives 60
A large number of μm porous spaces were formed in the dispersion layer.
After this, the dispersion layer was exposed to light, and then the cured shell resin of the microballoon was eluted with acetone to obtain a filter having a porous structure. In this experiment, the microballoons in the dispersion layer had a volume average particle size of 7 μ before expansion.
m, which after expansion was about 20 μm.

<Experiment 2> The Expansell 55IDE-20 microballoon (trade name: manufactured by Expancel), which is an expanded microballoon, was used as the microballoon in Experiment 1, and the heating step was not performed. A filter was prepared in the same manner as in Experiment 1 except for the above.

<Experiment 3> A filter was prepared in the same manner as Experiment 1 except that the binder resin was changed to Nitron T8526 (trade name: manufactured by Nitto Denko Corporation) which is a thermosetting resist, and the exposure step was not performed. Created.

<Experiment 4> A filter was prepared in the same manner as Experiment 2 except that the binder resin was changed to a thermosetting resist, Nitron T8526 (trade name: manufactured by Nitto Denko Corporation), and the exposure step was not performed. Created.

<Experiment 5> A filter was prepared in the same manner as in Experiment 3 except that the filter material was not dried and the heating step was rapidly heated to 120 ° C.

<Experiment 6> A filter was prepared in the same manner as in Experiment 1 except that the solvent was changed from acetone to ethanol.

<Experiment 7> The content of the microballoon was 1
A filter was prepared in the same manner as in Experiment 1 except that the content was 0 wt%.

<Experiment 8> The content of the microballoon was 2
A filter was prepared in the same manner as in Experiment 1 except that the content was 0 wt%.

<Experiment 9> The content of the microballoon was set to 9
A filter was prepared in the same manner as in Experiment 1 except that the content was 0 wt%.

<Experiment 10> A filter was prepared in the same manner as in Experiment 1 except that the content of the microballoon was 95 wt%.

The following items were evaluated for the filters obtained in Experiments 1 to 10 above. The results are shown in Tables 1 and 2.

[0075]

[Table 1]

[0076]

[Table 2]

Pore diameter: The diameter of the pores formed by a metallurgical microscope was measured, an average value was obtained based on the measurement results, and the obtained results are shown in Tables 1 and 2 above.

Dispersion state of microballoons in dispersion:
Observe the dispersed state of the micro balloons with a metallurgical microscope,
The sparse one is represented by L, the suitable one is represented by M, and the dense one is represented by H.

Flow resistance value as a filter: The flow resistance value was measured with a manometer using water as a liquid, and the obtained measurement results are shown in Tables 1 and 2 above.

Filter performance: It was examined whether or not dust of 30 μm or more could be removed by actually passing ink through the obtained filter. The obtained results are shown in Tables 1 and 2 based on the following criteria.

◯: A filter that functions sufficiently,
X: Those that cannot function as a filter.

Generally, the flow resistance of the filter used as a filter is preferably in the range of 10 to 100 mmAq, although it depends on the diameter of the dust to be removed.

As is clear from Table 1, according to Experiments 1, 2, 4, 5, 8 and 9 belonging to the present invention, a filter having excellent performance can be formed.

However, Experiments 3, 6, 7, and 10 did not fully function as filters. The reason for this is as follows.

In Experiment 3, the binder resin was cured without expanding the microballoons. This is because the drying step is performed at a temperature lower than the temperature at which the microballoons start to expand, so that the thermosetting resin that is the binder resin cures during the drying step and the microballoons cannot expand and the filter function is achieved. No tissue was formed.

In Experiment 6, by using ethanol as the solvent, the shell did not elute sufficiently and the pores did not communicate with each other, so that the tissue functioning as a filter was not formed.

In Experiment 7, the content of the microballoons was too small so that the expanded microballoons were not in sufficient contact with each other and the pores could not be communicated.

In Experiment 10, since the content of the microballoons was too large, too many pores were formed, and as a result, sufficient tissue strength was not secured and the filter function was not achieved. It was

Next, the case where the filter of the present invention is applied to an ink jet device will be described.

Hereinafter, an ink jet device to which the filter of the present invention can be applied will be described in detail with reference to the drawings.

2 and 4 show examples of the construction of an ink jet head and an ink jet printer to which the filter of the present invention can be applied. In this figure, IJH is an ink jet head of a system that ejects ink onto recording paper by using bubbles generated by thermal energy, IJC (11)
Is integrated with the inkjet head IJH (10).
Ink cartridge IC (12) that supplies ink to H
The inkjet cartridge, which is equipped with the above, and is attachable to the apparatus, and the IJA are the inkjet apparatus main bodies.

Inkjet cartridge IJ in this example
As can be seen from the perspective view of FIG. 2, C is slightly larger than the front surface of the ink cartridge IC, the ink jet head IJ.
The tip of H has a protruding shape. The inkjet head cartridge IJC is a disposable type which is fixedly supported by a carriage HC mounted on an inkjet apparatus main body IJA, which will be described later, and detachable from the carriage HC.

The ink cartridge IC (12) storing the ink supplied to the ink jet head IJH is
It is composed of an ink absorber, a container into which the ink absorber is inserted, and a lid member (not shown) for sealing the container. The ink cartridge IC (12) is filled with ink, and the ink is sequentially supplied to the inkjet head side in accordance with the ejection of the ink.

This ink jet cartridge is for a color image and includes black (Bk), cyan (C),
Four types of ink cartridges (12a, 12a) corresponding to magenta (M) and yellow (Y) inks
b, 12c and 12d), and these ink cartridges are individually provided with an ink supply pipe IP.
Ink is supplied to the distributor DB (13) of the inkjet head via (14). The distributor DB (13) is provided with the four ink supply nozzles IP (14) as described above, and the ink cartridges IC-B (12a), IC-Y (12b), and IC-
It is connected to M (12c) and IC-C (12d). There are two types of ink cartridges, one of which has three colors of IC-Y, IC-C, and IC-M, and the other of which has three different colors, and can be used as necessary. The ink cartridge can be replaced by the user, and when the ink runs out, the old one is removed and a new one is installed. At this time, the bubbles generated between the ink supply nozzle and the ink tank are recovered by the recovery function provided in the apparatus main body IJA, so that the printing defect can be prevented. In the distributor DB (13),
A filter is provided to prevent the inflow of dust and protects the nozzles and supply pipes from the dust flowing from the ink tank. Further, a filter valve is provided in the nozzle communicating with the ink cartridge IC-B so that bubbles accumulated in the filter portion are easily removed during recovery.

Inkjet head I according to the present invention
The JH structure will be described in more detail.

In FIG. 3, 100 is an electrothermal converter (discharge heater) arranged in a plurality of rows on the Si substrate 303.
102 and electric wiring 10 such as Al for supplying electric power to the electric wiring 102.
1 is a heater board (discharging element) formed by a film forming technique. 200 is heater board 1
Wiring corresponding to the wiring of the heater board 100 (for example, wire bonding 202
Connected to each other) and a pad 201 located at the end of this wiring and receiving an electric signal from the main body device. Reference numeral 300 denotes an ink supply port 301 for supplying ink to a plurality of ink flow paths, a partition wall for partitioning the ink supplied from each ink supply port, and an ink storage for supplying ink to each ink flow path. A common plate 302 having a common liquid chamber 302 and recesses such as a plurality of orifices 104 for ejecting ink, and receiving ink supplied from the ink cartridge IC and introducing the ink into the common liquid chamber 302 described above. An ink flow path is formed up to the orifice 104. The top plate having such a recess is formed of, for example, processed glass. Borosilicate glass is preferable as these processed glasses, but other glasses or molding resin materials may be used. The top plate 300 and the discharge element 100 are bonded with an epoxy adhesive. As this adhesive, a photo-curing adhesive, one that is cured by a combination of light and heat curing, or one that is cured by heat is used. The ejection element 100 is adhered by a silicone or epoxy adhesive. As the adhesive, one having good adhesiveness and good thermal conductivity for radiating the heat generated by the ejection element is selected. The support (base plate) 400 is a distributor DB.
Are positioned by the three positioning holes and are held by fusion by heat fusion. Distributor DB and discharge element 100
The connection between the ink supply member and the ink supply port 30 is sealed with a two-component sealant, and the periphery of the connection port and the wire-bonded periphery are simultaneously sealed with the sealant. In the ink jet head IJH of this example, when the ink jet head IJH is fixed to the carriage HC and the ink runs out, the user can replace the ink cartridge only and thereby avoid variations in print quality due to the replacement.

FIG. 4 is a diagram for explaining a schematic structure of an ink jet apparatus IJA to which the present invention is applied, and rotates via driving force transmission gears 5011 and 5009 in association with forward and reverse rotations of a drive motor 5013. The carriage HC that engages with the spiral groove 5004 of the lead screw 5005 has a pin (not shown) and is reciprocated in a predetermined direction. Reference numeral 5002 denotes a paper pressing plate that presses the paper against the platen 5000 in the carriage movement direction.
Reference numerals 5007 and 5008 denote photocouplers, which are used to confirm the presence of the carriage lever 5006 in this area and to drive the motor 501.
3 is a home position detecting means for switching the rotation direction of the motor 3. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the inkjet head. Reference numeral 5015 is a means for suctioning the inside of the cap to perform suction recovery of the inkjet head through the opening 5023 in the cap. 5017 is a cleaning blade, 50
Reference numeral 19 denotes a member that allows the blade to move in the front-rear direction, and these members are supported by the main body support plate 5018.
Needless to say, a well-known cleaning blade can be applied to this example instead of this form. Also, 5
012 is a lever for starting suction for suction recovery,
The carriage 50 moves along with the movement of the cam 5020 that engages the carriage, and the driving force from the driving motor is movement-controlled by a known transmission means such as clutch switching.

The capping, cleaning, and suction recovery are configured so that the desired processing can be performed at their corresponding positions by the action of the lead screw 5005 when the carriage comes to the home position side area.
If the desired operation is performed at a known timing, the invention can be applied not only to this embodiment but also to any ink jet head.

Hereinafter, a particularly preferable method for manufacturing an ink jet head when the filter of the present invention is applied to the ink jet head will be described.

First, the following three methods are known as conventional methods for manufacturing an ink jet head.

The first method is a step of preparing a substrate provided with an electrothermal converter including an energy generating element, a discharge port, an ink flow path and a member made of glass or metal by a processing means such as cutting or etching. A step of obtaining a top plate by providing a recess for forming a liquid chamber and a supply port for communicating the liquid chamber with the outside, and aligning the top plate with the substrate on the position of the energy generating element and the liquid flow path In this way, the step of attaching with an adhesive, the filter is attached to the ink supply port, the ink supply member is overlapped with the ink supply port and brought into close contact, and then the ink supply member is fixed and then sealed around the ink communication passage. The process of pouring and fixing the material,
Consists of.

In this first method for manufacturing an ink jet head, when the ink supply port provided on the top plate and the ink supply member are brought into close contact with each other with the ink filter interposed therebetween, the accuracy of the thickness of the top plate and the ink supply member Depending on the molding accuracy, a gap may occur between the top plate and the ink supply member.
There is a problem that the sealing material flows in from this gap to contaminate the surface of the filter, making the foaming of the ink unstable, resulting in deterioration of the printing quality.

Next, the second method is a step of preparing a substrate provided with an electrothermal converter including an energy generating element, and an ink discharge port, an ink flow path, and an ink liquid chamber are integrally made of resin by injection molding. A step of preparing the formed top plate, a step of fixing the top plate to the substrate such that the positions of the energy generating element and the liquid flow path are aligned, and preliminarily leaving a gap with a spring or the like to press-contact and fix; After the ink supply member having a cantilever structure in which a filter is attached to the joint part of and the ink supply port formed at the time of injection molding are brought into close contact with the top plate, the gap between the substrate and the top plate and A step of pouring several kinds of sealing materials into the pressure contact portion of the ink supply member and the ink supply port to simultaneously seal them,
Consists of.

In the second method for manufacturing an ink jet head, a gap portion provided in advance between the substrate and the top plate, the ink supply port of the top plate formed by injection molding, and the ink supply formed by the mold are supplied. A member and a portion in which the member is brought into close contact by utilizing the elastic force of the ink supply member are simultaneously sealed. At this time, the top plate and the ink supply member are controlled by the top plate, and the effective area of the filter cannot be taken. Therefore, a large-area supply port is provided on the ink tank side of the ink supply member, and a filter is welded there to prevent dust from entering the common liquid chamber. However, the encapsulant is mixed in from the joint between the substrate and the top plate, and the surface of the heating resistor, which is an energy generating element, is contaminated, clogging of the ejection port and destabilization of foaming, resulting in deterioration of print quality. There are problems such as waking up.

In order to solve the problems in the first and second manufacturing methods, the following third method is known.

According to this method, a positive or negative photosensitive dry film is attached to a substrate provided with an electrothermal converter including an energy generating element, and the ink discharge port, the ink flow path, and the ink of the photosensitive dry film are attached. A step of forming a solid layer having a pattern corresponding to a discharge port, an ink flow path and a liquid chamber on a first substrate by developing after exposing by exposing a mask or a pattern corresponding to the liquid chamber, the solid layer and the substrate An active energy ray-curable material that is hardened by active energy rays is applied to a predetermined thickness on the top of the liquid, and an active energy ray-transparent ceiling provided with a recess for forming a part of the liquid chamber and an ink supply port. A step of adhering a plate on the active energy ray-curable material in such a manner that a concave portion is aligned with a position where a liquid chamber is to be formed to form a laminated body; A step of masking the top plate so as to hide a portion where a liquid chamber is to be formed and irradiating the active energy ray-curable material with the active energy ray through the top panel to cure the active energy ray-curable material. After cutting the laminate at the position where the discharge port is formed to expose the end face of the solid layer, the solid layer and the uncured active energy ray-curable material are immersed in a solvent to dissolve the solid layer from the laminate. And a step of dissolving and removing the uncured active energy ray-curable material to provide a space for forming an ink flow path and a liquid chamber inside, and an ink supply member having an ink filter built-in inside the ink supply port. And a sealing material is poured around the gap and fixed (see JP-A-62-253457).

However, this third ink jet head manufacturing method has the following problems.

That is, the third method is to enlarge the recess for forming a part of the liquid chamber provided in the top plate,
Although there is an advantage that an inkjet head having a large liquid chamber can be manufactured, and an advantage that the problem that occurs when the substrate and the top plate are attached can be solved as in the first method described above, Similarly, there is a problem that the process is complicated, it takes time, and mass productivity is poor. Furthermore this third
In the method (1), when the filter is used for a special purpose such as four colors and three colors, there is a problem in that the filter is attached and the structure causes a problem.

In view of these problems, the present inventors have found the following method of manufacturing an ink jet head to which the filter of the present invention is applied. That is, in the method for manufacturing an inkjet head of the present invention, a) a heating resistor that generates thermal energy for ejecting ink and an electrical signal that is electrically connected to the heating resistor to generate the thermal energy. A step of forming an ink jet head substrate on which an electrothermal converter having wiring for supplying to the heat generating resistor is arranged; and b) an ink ejection port, an ink flow path, and an ink common liquid chamber on the substrate. And a step of providing a removable solid layer on a portion corresponding to the ink flow path system including the ink supply port, c) a step of laminating the substrate and a coating material for coating the solid layer, and d) removal of the solid layer. To form an ink flow path system, and e) a large number of fine particles formed by encapsulating a solvent-soluble resin in at least a part of the formed ink flow path. A layer made of a dispersion of hollow spheres (microballoons) dispersed in an active energy curable (heat or photocurable) resin is formed, and f) the layer formed in step e) is heat-treated to form the micro Inflating each of the balloons and then curing the active energy curable (heat or photocurable) resin; and g) in a solvent having selective solubility only for each shell of the microballoons in f) above. A filter is formed by treating the treated dispersion layer to remove the respective shells of the microballoons so that the pores of the microballoons are in communication with each other.

The method of manufacturing the ink jet head of the present invention having the above structure will be specifically described below.

That is, the electrothermal converter is provided on the substrate by the thin film forming technique used in the semiconductor technique. After that, a solid layer made of a removable material is formed on the substrate on the portion where the ink ejection port, the ink flow path, the ink liquid chamber, and the ink supply port are to be formed. Here, the solid layer can be accurately formed by forming the solid layer by photolithography using a positive photosensitive resist.

Next, a curable resin is coated so as to cover the substrate and the solid layer formed on the substrate. Further, a top plate having an ink liquid chamber and an ink supply port may be joined to the substrate on which the coating material is laminated.

Then, the removable solid layer is removed from such a laminated body with a solvent to form an ink ejection port, an ink flow path, an ink liquid chamber, and an ink supply port.

During the manufacturing process of the ink jet head manufactured by such a process, a large number of micro hollow spheres (micro balloons) encased in a shell composed of a solvent-soluble resin are used as active energy. After forming a layer composed of a dispersion dispersed in a curable (heat or photocurable) resin and curing the active energy curable (heat or photocurable) resin, only each shell of the microballoon is formed. A filter is formed by treating the dispersion layer with a solvent having a selective solubility for, and removing the respective shells of the microballoons so that the pores of the microballoons are in communication with each other.

The step of providing the microballoon-containing curable resin dispersion is preferably performed after the ink liquid chamber is formed, but may be after the solid layer forming step and before the solid layer is removed. Further, the step of removing the shell of the microballoon may be performed simultaneously with the removal of the solid layer.

The microballoon-containing curable resin dispersion is prepared by injecting the microballoon-containing curable resin dispersion into the liquid chamber and then heating it to form pores, and by heating the microballoon in advance. Is expanded and then dispersed in a binder resin, and a microballoon-containing curable resin dispersion obtained is injected into the liquid chamber. Which one is selected may be selected depending on the size of the liquid chamber, the size of the ink supply port, and the structure of the liquid chamber. The method of applying the microballoon-containing curable resin dispersion can be performed by screen printing, tambo printing, dispenser injection or the like. The injection method is selected depending on the type of microballoon and the method of inflating.

The microballoon-containing curable resin dispersion layer is preferably provided in the ink common liquid chamber, and is provided in the space of the ink common liquid chamber as a member different from other components. Good.

The substrate is preferably provided with an ink ejection energy generating element, and the ink ejection energy generating element is preferably an electrothermal conversion element.

When the ink jet head having the above-mentioned characteristics is provided in the ink jet apparatus, a recording operation superior to the conventional one can be performed.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 FIG. 5 shows a state in which a filter-forming dispersion obtained by dispersing microballoons in a binder resin is injected into a common liquid chamber.

Further, FIG. 6 shows a state in which the binder resin having a porous structure after the shell resin of the microballoon according to the present invention is removed serves as a filter.

In FIGS. 5 and 6, reference numeral 1 is an electrothermal conversion element, 2 is a substrate, 3 is a discharge port (orifice), 4 is an ink flow path, 5 is a dispersion layer, 6 is an ink supply port, and 7 is A resist, 8 is a second substrate, and 9 is a common liquid chamber.

First, a positive dry film OZAT was formed on a silicon substrate on which an electrothermal conversion element (material HfB ₂ ) was formed.
EC R225 (Trade name: Hoechst Japan KK)
And a photosensitive layer having a thickness of 50 μm was formed by lamination. After irradiating the portion of the photosensitive layer excluding the portion where the liquid flow path is to be formed with ultraviolet rays, spray development is performed using a 1% caustic soda aqueous solution, and the portion where the liquid flow path is to be formed on the silicon substrate including the electrothermal conversion element Solid layer (thickness 5
0 μm) was formed. Next, Araldite CY230 / HY956 (trade name: manufactured by Ciba Geigy), which is an epoxy resin as a thermosetting material, was applied on the substrate on which the solid layer was formed using an applicator. Then, the substrate was left at 30 ° C. for 12 hours to completely cure the curable material on the substrate. Next, a glass substrate as a top plate having a concave portion at a liquid chamber formation planned site and a through hole (ink supply port 6) for supplying ink at the center of the concave portion is formed on the substrate laminated with the curable material. The positions of the planned chamber formation sites were aligned and joined.

Next, a filter-forming dispersion prepared by dispersing microballoons in the binder resin of the present invention is formed on the solid layer in the liquid chamber formation-scheduled portion on the ink supply port 6.
It was injected with a dispenser. Here, the dispersion is based on Oder SY25 (trade name: manufactured by Tokyo Ohka Co., Ltd.), which is a photosensitive curable resin, and 50 wt% of Expancel 55IDE-20 microballoon (trade name: manufactured by Expancel). %, And a homogenized dispersion was used. Here, the addition amount of the microballoons is 50%, but it can be appropriately selected within the range of 20 to 90 wt%.

Next, the joined body of the substrates and the top plate was irradiated with ultraviolet rays to solubilize the solid layer. Then NaOH
The sample was immersed in an aqueous solution, the solubilized solid layer was dissolved and removed in an ultrasonic cleaning tank for about 10 minutes, and the sample was washed with pure water and dried. This completed the inkjet head.

The flow resistance value of the filter formed in this example has a correlation with the ink flow rate in the range of 10 to 100 mmAq.

Further, when the ink jet head obtained in this example was printed on 3000 sheets of A4 size 7.5% duty at an ejection frequency of 10 kHz,
The print quality was good, and no blurring of characters or ejection failure was observed.

<Embodiment 2> FIG. 7 is for explaining a method of manufacturing an ink jet head in this embodiment. In FIG. 7, reference numeral 2 is a substrate, 5 is a filter-forming dispersion obtained by dispersing microballoons in a binder resin, and 7 is a resist (solid layer).

In Example 1, the expanded microballoons were dispersed in the resist and injected into the common liquid chamber. However, in this Example, the same as Example 1 except that unexpanded Expancel 551DU was used as the microballoons. In the same manner, a dispersion for forming a filter was obtained, which was applied onto the resist pattern by screen printing, and then dried at 60 ° C. for 2 hours. The thickness of the dispersion layer after drying was 100 μ ±
The thickness was 10 μm, and no adverse effects (peeling during printing, film thickness accuracy, printing bleeding, etc.) due to the addition of 50 wt% of microballoons were observed. Next, prior to bonding the top plate to the substrate, the dry dispersion layer was heat-treated at a temperature of 120 ° C. At this time, the microballoons dispersed in the binder resin began to expand and reached a film thickness of 180 μm after 3 minutes. As a result, a large number of holes having an average diameter of 60 μm were formed. Next, after bonding the top plate to the substrate, the shell resin of the expanded microballoon was etched using a solvent to obtain a filter in which the pores communicate with each other. In this example, the microballoons in the dispersion layer had a volume average particle size of 7 μm without expansion and about 20 μm after the expansion treatment.

Further, when the ink jet head obtained in this example was printed on 3000 sheets of A4 size 7.5% duty at an ejection frequency of 10 kHz,
The print quality was good, and no blurring of characters or ejection failure was observed.

As described above, in the first and second embodiments,
By forming a filter made of a curable resin in the liquid chamber part on the solid layer, not only can the filter be integrally formed even in a complicated part in the inkjet head,
Does not require any special procedure or process for fixing the filter,
It is possible to create a filter having a relatively large area. Further, effects such as cost reduction of the assembly process, reduction of process control, and improvement of yield can be obtained.

Therefore, the present invention can inexpensively provide an ink jet head capable of high-speed printing and having high long-term reliability.

(Others) The present invention is particularly provided with means for generating thermal energy as energy used for ejecting ink (for example, an electrothermal converter or laser light) even in the ink jet recording system. The present invention brings about excellent effects in an inkjet head and an inkjet apparatus of the type in which the thermal energy causes a change in the state of the ink. This is because such a system can achieve high density recording and high definition recording.

Regarding its typical structure and principle, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter to cause film boiling on the heat acting surface of the inkjet head. This is effective because bubbles can be generated in the liquid (ink) corresponding to this drive signal one-to-one as a result. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the ink jet head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The present invention also includes a configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the heat acting portion is arranged in a bending region. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the inkjet head.

Furthermore, the present invention can be effectively applied to a full line type ink jet head having a length corresponding to the maximum width of a recording medium which can be recorded by the ink jet apparatus. Such an inkjet head may have either a configuration that satisfies the length by a combination of a plurality of inkjet heads or a configuration that is one integrally formed inkjet head.

In addition, even in the case of the serial type as in the above example, an ink jet head fixed to the apparatus main body,
Alternatively, a replaceable chip-type inkjet head that can be electrically connected to the device body and supply ink from the device body by being attached to the device body, or an ink tank integrated with the inkjet head itself The present invention is also effective when the cartridge type inkjet head described above is used.

Further, as the constitution of the ink jet device of the present invention, it is preferable to add the ejection recovery means of the ink jet head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed using a capping means, a cleaning means, a pressurizing or sucking means for the ink jet head, an electrothermal converter or another heating element or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of ink jet heads to be mounted, for example, only one ink jet head is provided corresponding to a single color ink, or a plurality of inks having different recording colors or densities are provided. A plurality of pieces may be provided. That is, for example, the recording mode of the inkjet apparatus is not limited to the recording mode of only the mainstream color such as black, and may be either integrally formed with the inkjet head or by a combination of a plurality of colors. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the inkjet device of the present invention is used as an image output terminal of an information processing device such as a computer, a copying device combined with a reader or the like, and a facsimile device having a transmission / reception function. May be used.

Although the filter of the present invention has been described as being applied to an ink jet apparatus, the use of the filter of the present invention is not limited to this, and the filter of the present invention can be applied to other fields. The effect that it has can be exhibited sufficiently.

[0144]

As described above, the filter according to the present invention is a filter used for filtering a liquid, in which a large number of pores based on microballoons are formed in a cured active energy curable resin layer. The plurality of holes are in communication with each other so that the liquid can pass through the resin layer. Therefore, even in the case of a complicated structure or a fine structure such as various devices, the constituent members of those structures can be integrally formed with high precision.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating a method for producing a filter of the present invention, in which (A) is a schematic cross-sectional view of a layer composed of a dispersion of microballoons dispersed in a binder resin,
(B) is a schematic cross-sectional view of the dispersion layer shown in (A) in a state where the dispersion layer shown in (A) is heat-treated to vaporize the core components of the microballoons to expand the shell resin, and (C) is (B). FIG. 3 is a schematic cross-sectional view showing a state in which the dispersion layer shown in FIG. 2 is subjected to an etching treatment using a selective solvent to dissolve the shell resin and make the pores of the microballoons communicate with each other. .

FIG. 2 is a perspective view for explaining an overall configuration of an inkjet cartridge having an inkjet head and an ink cartridge according to the present invention.

FIG. 3 is a perspective view for explaining a detailed configuration around an ink supply port of an inkjet head according to the present invention.

FIG. 4 is a perspective view showing a main part of an inkjet device in which an inkjet cartridge according to the present invention is mounted.

FIG. 5 is a view for explaining one embodiment of a method for manufacturing an inkjet head according to the present invention, in which the porous curable resin after the shell of the microballoon according to the present invention is removed serves as a filter. It indicates that

FIG. 6 is a diagram for explaining a state in which a curable resin containing minute hollow spheres is injected into the common liquid chamber.

FIG. 7 is a diagram for explaining another embodiment of the method for manufacturing an inkjet head according to the present invention.

[Explanation of symbols]

 51 Curable Resin 52 Micro Balloon 53 Core 54 Thermoplastic Resin 55 Pore

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B41J 2/16 C08J 9/38 7310-4F B41J 3/04 103 H

Claims (31)

[Claims] 1. A filter used for filtering a liquid, wherein a large number of pores based on microballoons are formed in a hardened active energy curable resin layer, and the large number of pores are the liquid. A filter characterized by being communicated so that it can pass through a resin layer. 2. The pores are formed by a microballoon having a core containing a substance that vaporizes and expands at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component. The filter described in. 3. The filter according to claim 2, wherein the material forming the core comprises a component selected from the group consisting of isobutane and isobutylene. 4. The thermoplastic resin is polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer,
3. A main component of at least one component selected from the group consisting of an acrylonitrile-vinyl chloride copolymer and a vinyl acetate-vinyl chloride copolymer.
The filter described in. 5. The filter according to claim 1, wherein the active energy curable resin is a curable resin that is cured by heat or light. 6. The filter according to claim 1, wherein the filter has a thickness parallel to the liquid supply direction that is 5 times or more the diameter of the hole. 7. The filter according to claim 1, wherein the filter is used as a part of an ink supply path of an inkjet device. 8. An ejection port for ejecting ink, a heating resistor for generating thermal energy for ejecting ink from the ejection port, and for generating the thermal energy electrically connected to the heating resistor. An ink jet head substrate having an electrothermal converter having a wire for supplying an electric signal to the heating resistor, and an ink supply system for supplying ink, wherein A large number of pores are formed in a cured resin layer in a part of the ink supply system, and a filter is provided which communicates with the pores so that liquid can pass through the resin layer. Inkjet head. 9. The voids are formed by microballoons having a core containing a substance that vaporizes and expands at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component. The inkjet head described in 1. 10. The ink jet head according to claim 9, wherein the substance forming the core comprises a component selected from the group consisting of isobutane and isobutylene. 11. The thermoplastic resin is polyvinyl chloride,
It is characterized by containing at least one component selected from the group consisting of polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer as a main component. The inkjet head according to claim 9. 12. The inkjet head according to claim 8, wherein the active energy curable resin is a curable resin that is cured by heat or light. 13. The ink jet head according to claim 8, wherein the average diameter of the holes is 30 μm or less. 14. The ink jet head according to claim 8, wherein the filter has a thickness parallel to the ink supply direction of 5 times or more the diameter of the hole. 15. A method for manufacturing a filter for filtering a liquid, comprising a dispersion comprising a large number of microballoons encapsulated in a solvent-soluble resin shell dispersed in an active energy curable resin. And heat-treating the dispersion to expand each of the microballoons, then cure the active energy curable resin, and disperse the dispersion with a solvent having selective solubility only in each shell of the microballoons. A method for producing a filter, which comprises treating a body to remove respective shells of the microballoons so that pores of the microballoons communicate with each other. 16. The microballoon according to claim 15, wherein a shell containing a thermoplastic resin as a main component has as a core a substance that vaporizes and expands at a temperature higher than room temperature. Filter manufacturing method. 17. The method for manufacturing a filter according to claim 16, wherein the material forming the core is selected from the group consisting of isobutane and isobutylene. 18. The thermoplastic resin is polyvinyl chloride,
It is characterized by containing at least one component selected from the group consisting of polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer as a main component. The method for manufacturing the filter according to claim 16. 19. The method of manufacturing a filter according to claim 15, wherein the active energy curable resin is a curable resin that is cured by heat or light. 20. The method of manufacturing a filter according to claim 15, wherein the filter has a thickness parallel to the liquid supply direction that is 5 times or more the diameter of the hole. 21. The method for manufacturing a filter according to claim 15, wherein the content of the microballoons in the active energy curable resin is 20 to 90 wt%. 22. The method for producing a filter according to claim 15, wherein the solvent having selective solubility is selected from the group consisting of acetone and dimethylformamide. 23. The method of manufacturing a filter according to claim 15, wherein the filter is used in a part of an ink supply path of an inkjet device. 24. A method of manufacturing an inkjet head, comprising: a) a heating resistor that generates thermal energy for ejecting ink, and the heating resistor is electrically connected to the heating resistor. A step of forming an ink jet head substrate on which an electrothermal converter having an electric signal for generating an electric signal for generating the above is provided, and b) an ink ejection port on the substrate, A step of providing a removable solid layer in a portion corresponding to an ink flow path system including an ink flow path, an ink common liquid chamber, and an ink supply port; and c) a step of laminating the substrate and a coating material for coating the solid layer. D) removing the solid layer to form an ink flow path system, and e) a shell composed of a solvent-soluble resin in at least a portion of the formed ink flow path. A layer composed of a dispersion in which a large number of encased microballoons are dispersed in an active energy curable (heat or photocurable) resin is formed, and f) the layer formed in the step e) is heat-treated. Inflating each of the microballoons and then curing the active energy curable resin; and g) a dispersion layer treated in f) with a solvent that has selective solubility only for each shell of the microballoons. The method for producing an ink jet head, wherein the filter is formed by removing the shells of the microballoons so that the holes of the microballoons are communicated with each other. 25. The ink jet head according to claim 24, wherein the microballoon has, as a core, a substance that is vaporized / expanded at a temperature higher than room temperature in a shell containing a thermoplastic resin as a main component. Production method. 26. The method according to claim 25, wherein the material used for the core is a component selected from the group consisting of isobutane and isobutylene. 27. The thermoplastic resin is polyvinyl chloride,
It is characterized by containing at least one component selected from the group consisting of polyvinylidene chloride, vinyl chloride-vinyl chloride copolymer, acrylonitrile-vinyl chloride copolymer and vinyl acetate-vinyl chloride copolymer as a main component. The method for manufacturing an inkjet head according to claim 25. 28. The method for manufacturing an inkjet head according to claim 24, wherein the active energy curable resin is a curable resin that is cured by heat or light. 29. The method according to claim 24, wherein the filter has a thickness parallel to the liquid supply direction that is 5 times or more the diameter of the hole. 30. The method of manufacturing an inkjet head according to claim 24, wherein the content of the microballoons in the active energy curable resin is 20 to 90 wt%. 31. The method of manufacturing an inkjet head according to claim 24, wherein the solvent having selective solubility is selected from the group consisting of acetone and dimethylformaldehyde.