KR101191597B1 - Ink reservoir for ink jet printing and Ink printing apparatus comprising the same - Google Patents

Abstract

The present invention relates to an ink storage device for ink jet printing and an ink jet printing device having the same. An ink storage apparatus for an inkjet printing apparatus of the present invention, the housing having an empty space therein; The interior of the housing transverse in the horizontal direction and is in close contact with the inner wall of the housing to maintain an airtight state, the interior of the housing is defined as the lower ink reservoir and the upper pressure regulator, the fluid impermeable material Hermetic pressure regulating member formed of; Pressure regulating member adjusting means for adjusting the position or shape of the pressure regulating member upward or downward to increase or decrease the size of the area of the ink reservoir in the housing; An ink injection line connected to an ink injection hole and an ink injection hole formed on one surface of the ink reservoir of the housing; An ink circulation line connecting the circulation ink discharge port formed on the bottom surface of the housing and the circulation ink inlet port formed on the side of the ink storage portion of the housing and having an ink circulation pump; And an ink transfer line connecting the ink outlet and the ink jet head formed on the bottom surface of the housing. The ink storage device of the present invention keeps the viscosity of the ink constant to prevent deterioration of ink ejection performance.

Inkjet Printing, Storage Devices

Description

Ink storage device for ink jet printing and ink jet printing device having the same {Ink reservoir for ink jet printing and Ink printing apparatus comprising the same}

The present invention relates to an ink storage device for ink jet printing and an ink jet printing device having the same. More particularly, the present invention relates to an ink storage device for ink jet printing capable of suppressing evaporation of a solvent contained in the ink, and an ink jet printing device having the same.

Recently, as the exhaustion of existing energy resources such as oil and coal is predicted, interest in energy that can replace them is increasing. As one of the alternative energy sources, the fuel cell is particularly attracting attention due to its advantages such as high efficiency, no pollutants such as NO _x and SO _x , and abundant fuel used.

A fuel cell is a power generation system that converts chemical reaction energy of a fuel and an oxidant into electrical energy. Hydrogen, a hydrocarbon such as methanol, butane, and the like are typically used as an oxidant.

In a fuel cell, the most basic unit for generating electricity is a membrane electrode assembly (MEA), which consists of an electrolyte membrane and anode and cathode electrodes formed on both sides of the electrolyte membrane. Oxidation reaction of fuel occurs at the anode electrode to generate hydrogen ions and electrons, and hydrogen ions move to the cathode electrode through the electrolyte membrane, and at the cathode electrode, oxygen (oxidant) and hydrogen ions and electrons transferred through the electrolyte membrane react with water. Is generated. This reaction causes electrons to migrate to the external circuit.

The ^{_{anode: H 2 → 2H + + 2e}} -

^{_{Cathode: 1 / 2O 2 + 2H +}} + 2e - → H 2 O

Total Reaction Formula: H ₂ + 1 / 2O ₂ → H ₂ O

The general configuration of a fuel cell membrane electrode assembly is composed of an anode electrode and a cathode electrode which are opposed to each other with an electrolyte membrane and an electrolyte membrane interposed therebetween, and the anode electrode and the cathode electrode are composed of a catalyst layer and a gas diffusion layer. The gas diffusion layer is composed of an electrode substrate and a microporous layer formed thereon.

When manufacturing a fuel cell membrane electrode assembly, the catalyst layer may be formed by directly applying an ink for forming a catalyst layer to an electrolyte membrane or a gas diffusion layer (GDL), and in this case, a spray method, inkjet printing, screen printing, decals, etc. Method is used. Among them, the inkjet printing method has a very high coating speed of the catalyst layer forming ink, minimizes catalyst loss, and can be implemented in various forms while being accurate at the position to be coated. can do.

In general, the inkjet printing method uses a method of generating a height difference between the ink storage device included in the inkjet printing apparatus and the inkjet head so that ink flows naturally into the inkjet head under the influence of gravity, and ejects the ink jet head. When the ink storage device is positioned higher than the inkjet head when using the ink, the ink just flows down through the inkjet head nozzle, and when the ink storage device is lower than the inkjet head, the ink is not supplied to the inkjet head and sprayed. There is a problem that the position adjustment between the ink storage device and the inkjet head for ejection is not easy, such as a case that is difficult to do.

Therefore, in order to solve this problem, rather than adjusting the height of the ink storage device and the inkjet head, the position of the ink storage device is higher than the inkjet head, and the state inside the ink storage device is maintained in vacuum instead. Thereby generating negative pressure in the ink storage device, thereby preventing the ink from flowing out of the inkjet head. In addition, the degree of ejection of ink from the inkjet head can be adjusted by appropriately adjusting the state inside the ink storage device.

However, even in such a case, if the vacuum is continuously maintained in the ink storage device, evaporation of the solvent of the ink for forming the catalyst layer is accelerated to change the properties of the ink, and the most problematic of these is the ink over time. Will increase the viscosity. Increasing the viscosity of the ink makes it difficult to effectively eject the ink from the inkjet head.

Therefore, it is urgent to develop a new ink storage device that can control the pressure in the ink storage device while preventing the solvent from evaporating the ink.

Accordingly, an object of the present invention is to provide an ink storage device which suppresses evaporation of an ink solvent so that the viscosity of the ink does not increase even when used for a long time, so that the jetting performance of the ink does not decrease.

In order to solve the above problems, the ink storage device for an inkjet printing apparatus of the present invention, the housing having an empty space therein; The interior of the housing transverse in the horizontal direction and is in close contact with the inner wall of the housing to maintain an airtight state, the interior of the housing is defined as the lower ink reservoir and the upper pressure regulator, the fluid impermeable material Hermetic pressure regulating member formed of; Pressure regulating member adjusting means for adjusting the position or shape of the pressure regulating member upward or downward to increase or decrease the size of the area of the ink reservoir in the housing; An ink injection line connected to an ink injection hole and an ink injection hole formed on one surface of the ink reservoir of the housing; An ink circulation line connecting the circulation ink discharge port formed on the bottom surface of the housing and the circulation ink inlet port formed on the side of the ink storage portion of the housing and having an ink circulation pump; And an ink transfer line connecting the ink outlet and the ink jet head formed on the bottom surface of the housing.

The ink storage device of the present invention, if necessary, purge gas inlet formed on the side of the ink reservoir of the housing and purge lines connected to the purge gas inlet, and / or excess ink from the inkjet head back to the ink reservoir An ink conveyance line can be further provided.

The ink storage device for ink jet printing described above can be usefully applied to a conventional ink jet printing device including an ink jet head.

The ink storage device for ink jet printing of the present invention can prevent the solvent from evaporating and disappearing because the portion in which the ink is stored is kept in an airtight state and the vapor pressure change of the ink solvent is not large. Accordingly, since the quality of the ink and the viscosity of the ink can be maintained at a constant level, it is possible to maintain a constant injection performance of the ink without changing the composition of the ink, so that the catalyst layer for fuel cells of uniform quality can be continuously produced for a long time. Can be.

Hereinafter, the present invention will be described in detail with reference to the drawings. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

1 schematically shows an embodiment of an ink storage device 100 according to the present invention. However, the configuration described in the embodiments and drawings described below are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, which can be replaced at the time of the present application It should be understood that there may be various equivalents and variations.

The outline of the ink storage device 100 of the present invention is defined by the housing 101. The housing 101 has a cavity formed therein, and stores the catalyst layer forming ink 300 in the cavity, and is provided with a pressure regulating member 104. The housing 101 may be made of a transparent or translucent material so that the state of the inside can be observed. In this case, if necessary, the scale 160 may be provided to specifically know the amount of ink.

The pressure regulating member 104 provided inside the housing 101 is formed to cross the inside of the housing in a horizontal direction and closely adheres to the inner wall of the housing. Separated by (103), and maintains an airtight state between the upper part and the lower part. That is, since the ink reservoir 103 in the housing is kept airtight by the pressure regulating member 104, it is possible to prevent the continuous evaporation loss of the ink solvent.

In addition, the pressure adjusting member 104 is changed in shape while the position is fixed to the inner wall of the housing 101, or the position of the lower ink reservoir 103 while the position is moved while being in close contact with the inner wall of the housing 101. By changing the size, the pressure of the ink reservoir 103 can be adjusted. Since the pressure regulating member 104 according to the present invention must maintain the airtight state, any pressure impermeable material that can not pass through the fluid can be used without limitation. For example, when the shape is modified to change the size of the region of the ink reservoir 103 as described above, it may be a fluid impermeable stretchable film, and the stretchable film may be made of a polymer film. It is not limited. In addition, when the position is moved, as shown in Figure 2, a representative piston type may be representative, but such a piston may be made of a polymer, a metal, etc. This is only an example, the present invention is not limited thereto.

The pressure adjusting unit 102 according to the present invention changes the size of the area of the ink storage unit 103 by adjusting the shape or position of the pressure adjusting member 104 through a pressure adjusting member adjusting means (not shown). When the pressure regulating member 104 is, for example, a flexible film having a fixed position on the inner wall, gas is supplied through the pressure regulating line 150 as a pressure regulating member adjusting means formed in the pressure regulating unit 102 of the housing 101. An apparatus (not shown) capable of deforming the stretched film by spilling or inflowing may be used. Such a device may be used without limitation as long as it is a device capable of introducing or discharging gas, for example, a pump and the like, but are not limited thereto. Alternatively, as shown in FIG. 2, when the pressure regulating member 104 is, for example, a piston, an apparatus (not shown) capable of operating the piston upward or downward may be used as the pressure regulating member adjusting means. As such a device, any device capable of operating the piston upward or downward may be used without limitation, and for example, a motor, a cam, and the like may be used, but is not limited thereto.

The process of changing the pressure of the ink reservoir 103 by changing the area size of the ink reservoir 103 will now be described in detail. That is, gas is introduced through the pressure regulating line 150 to increase the pressure of the pressure regulating unit 102 so that the stretchable film, which is the pressure regulating member 104, extends downward (B form in FIG. 1). When the piston moves downward, the size of the area of the ink reservoir 103 is reduced and the pressure regulating member 104 is kept airtight, thereby increasing the pressure of the ink reservoir 103 relatively. . On the contrary, the gas flows out through the pressure regulating line 150 to decrease the pressure of the pressure regulating unit 102 so that the stretchable film, which is the pressure regulating member 104, extends upward (A form in FIG. 1). When the piston moves upward, the size of the area of the ink reservoir 103 is increased and the pressure regulating member 104 is kept airtight, so that the pressure of the ink reservoir 103 is also relatively decreased. . In this way, the pressure of the ink reservoir 103 may be adjusted to control the degree of ejection of ink from the inkjet head 200.

The ink reservoir 103 according to the present invention stores the ink 300 to be transferred to the inkjet head 200. Therefore, an ink injection line 111 and an ink injection hole 110 receiving ink from an ink source (not shown) are formed on one surface of the ink storage unit 103 of the housing 101. If necessary, an ink filtration device 112 may be formed in the ink injection line 111 to supply more refined ink to the ink storage unit 103. As the ink filtration device 112, a filter commonly used may be used without limitation.

The ink storage device 100 of the present invention includes an ink circulation line 121 for continuous circulation of the ink stored in the ink storage unit 103. The ink 300 is not transferred to the inkjet head 200 through the ink circulation line 121, and prevents the formation of dead zones that are stagnant in the ink reservoir 103 and continuously mixes the stored ink 300. The effect can be obtained. In addition, since the catalyst layer forming ink 300 is mixed with various components such as catalyst particles, ionomers, organic solvents, and the like, a relatively dense component may sink to the bottom of the housing 101 over time. Can be. In this case, since the composition of the ink may vary depending on the position of the container, the ink circulation line 121 according to the present invention may solve this problem. The ink circulation line 121 connects the circulation ink outlet 120a formed at the bottom of the housing 101 with the circulation ink inlet 120b formed at the side of the housing 101 so that the stored ink can be circulated. 300) A pump 122 is provided on the line that provides a driving force for circulation.

Optionally, to obtain a better effect of ink circulation, the shape of the underside of the housing 101 may be in the form of a cone or polygonal pyramid with one vertex inclined downward. In this case, the circulating ink discharge port 120a is preferably formed on the vertex.

The ink storage apparatus 100 of the present invention includes an ink outlet 130a and an ink transfer line 131 for transferring ink to the inkjet head 200 to eject ink. The pressure of the ink reservoir 103 is adjusted so that an appropriate amount of ink 300 is transferred to the inkjet head 200 through the ink outlet 130a and the ink transfer line 131.

Optionally, the ink storage device 100 of the present invention conveys the ink for transferring the excess ink 300 back to the ink storage unit 104 when the excess ink 300 is transferred to the inkjet head 200. Line 132 may be further provided. The ink 300 conveyed through the ink conveying line 132 flows back into the ink storing unit 104 through the ink conveying port 130b formed on the side of the ink storing unit 104.

Optionally, the ink storage device 100 of the present invention may further include a purge gas inlet 140 and a purge line 141 connected to the purge gas inlet 140 on the side of the ink storage unit 103. . The purge line 141 introduces a purge gas into the ink reservoir 103 when the ink jet port 210 is blocked in the ink jet head 200, thereby increasing the pressure of the ink reservoir 103, thereby increasing the pressure of the ink jet port 210. Can be reopened. As the purge gas, air or an inert gas may be used without limitation.

The present invention also provides an inkjet printing apparatus including the ink storage device 100 of the present invention. 3 is a view schematically showing an inkjet printing apparatus according to an embodiment of the present invention. Referring to FIG. 3, the inkjet printing apparatus of the present invention includes an ink source 400, an ink storage device 100, and an inkjet head 200.

The ink source 400 is connected to the ink injection line 111 of the ink storage device 100 to supply ink for forming a catalyst layer to the ink storage device 100. In this case, a pump 410 may be further provided on the ink injection line 111 to supply ink to the ink storage device 100.

The inkjet head 200 receives ink from the ink storage device 100 through the ink transfer line 131 and injects ink through the ink injection port 210. The inkjet head 200 may eject ink after being moved to a required position through an inkjet head transferring means (not shown).

The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the contents of the present invention serve to further understand the technical spirit of the present invention, the present invention is limited to the matters described in such drawings. It should not be construed as limited.

1 is a view schematically showing an ink storage device according to an embodiment of the present invention.

2 is a view schematically showing a piston as a pressure regulating member of the ink storage device according to an embodiment of the present invention.

3 is a view schematically showing an example of an inkjet printing apparatus according to the present invention.

Claims (9)

A housing having an empty space therein; The interior of the housing is horizontally traversed and in close contact with the inner wall of the housing to maintain an airtight state, and the interior of the housing is defined as an upper pressure control unit and an lower ink storage unit, and a fluid impermeable material. Hermetic pressure regulating member formed of; Pressure regulating member adjusting means for adjusting the position or shape of the pressure regulating member upward or downward to increase or decrease the size of the area of the ink reservoir in the housing; An ink injection line connected to an ink injection hole and an ink injection hole formed on one surface of the ink reservoir of the housing; An ink circulation line connecting the circulation ink discharge port formed on the bottom surface of the housing and the circulation ink inlet port formed on the side of the ink storage portion of the housing and having an ink circulation pump; And An ink transfer line connecting the ink outlet and the ink jet head formed on the bottom surface of the housing; An ink storage device for an inkjet printing device having a. The method of claim 1, The housing has a bottom surface in the form of a cone or polygonal cone having one vertex in the downward direction, and the ink circulation line connects the circulation ink inlet formed at the vertex of the bottom of the housing and the circulation ink inlet formed at the side of the ink reservoir. An ink storage device for an inkjet printing device, characterized in that. The method of claim 1, And the housing is made of a transparent or translucent material. The method of claim 1, And the pressure regulating member is a stretchable film fixed to the inner wall of the housing, and the pressure regulating member adjusting means is a device for flowing gas into or out of the pressure regulating unit. The method of claim 1, The pressure regulating member is a piston, and the pressure regulating member adjusting means is a device for operating the piston upward or downward. The method of claim 1, And the ink injection line comprises a filtering device on the line. The method of claim 1, And a purge line connected to the purge gas inlet and the purge gas inlet formed on the side of the ink reservoir of the housing. The method of claim 1, And an ink conveying line for introducing excess ink from the inkjet head back to the ink storage unit. An inkjet printing apparatus comprising an ink storage device and an inkjet printing head, The ink storage device of claim 1, wherein the ink storage device is the ink storage device of any one of claims 1 to 8.

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