JP6341864B2 - Metal mesh manufacturing method, dehumidifying element, and dehumidifying element manufacturing method - Google Patents

Description

  The present invention relates to a metal mesh on which a plating film is formed, a method for producing the metal mesh, a dehumidifying element using the metal mesh, and a method for producing the dehumidifying element.

  Conventionally, after partially applying a liquid masking agent to the surface of the material, metal plating is applied to the non-application portion of the masking agent in the surface of the material, and then the masking agent is removed from the surface of the material, A partial plating method in which metal plating is partially performed on the surface of a material is known (for example, see Patent Document 1).

JP 2003-183877 A

  However, in the conventional partial plating method disclosed in Patent Document 1, when a liquid masking agent is applied to the surface of the material, masking is applied to the surface of the material due to the weight of the masking agent and the wettability of the material. The masking agent tends to spread to parts that should not be applied. For example, when a masking agent is applied to the upper surface of the mesh material and metal plating is applied to the lower surface of the mesh material, if the masking agent is applied to the upper surface of the mesh material, the masking agent passes through each hole of the mesh material and the lower surface of the mesh material. The metal plating cannot be applied to the entire lower surface of the mesh material. Therefore, it is difficult to accurately apply metal plating to a necessary portion of the mesh material, and there is a problem that the amount of metal plating used is excessive and the cost is increased.

  This invention was made in order to solve the problems as described above, a metal mesh capable of reducing the amount of metal constituting the plating film and reducing the cost, a method for producing the metal mesh, It aims at obtaining the dehumidification element and the manufacturing method of a dehumidification element.

  The metal mesh according to the present invention comprises a mesh material composed of metal, an oxide film formed by oxidizing the metal constituting the mesh material, and the mesh material covered with the oxide film while avoiding the oxide film. And a plating film made of a metal different from the metal constituting the mesh material, and in the thickness direction of the mesh material, the surface of the mesh material visible from one side of the mesh material is the first surface, and is visible from the other side of the mesh material When the surface of the mesh material is the second surface, the oxide film covers the first surface, and the plating film covers the second surface.

  According to the metal mesh of the present invention, even in a mesh material in which a plurality of holes are formed, the oxide film is selectively applied to the outer surface of the mesh material by blasting the mesh material 9 in which the oxide film is formed on the entire outer surface. Can be formed. As a result, the plating film can be easily and more accurately formed on the necessary portion of the mesh material, and the amount of metal used to form the plating film can be reduced to reduce the cost.

It is a typical block diagram which shows the dehumidification element by Embodiment 1 of this invention. It is a front view which shows the anode electrode of FIG. It is a typical block diagram explaining the dehumidification operation | movement of the dehumidification element of FIG. FIG. 4 is a schematic configuration diagram showing the behavior of electrons e ⁻ on the anode electrode side in FIG. 3. It is a flowchart explaining the procedure at the time of manufacturing the dehumidification element of FIG. It is a typical block diagram which shows the lamination | stacking order of the cathode electrode of FIG. 1, a cathode side catalyst layer, an electrolyte membrane, and an anode electrode. It is a flowchart which shows the procedure at the time of manufacturing the dehumidification element by Embodiment 2 of this invention. It is a front view which shows the mesh material which eliminated the plating film from the metal mesh by Embodiment 3 of this invention. It is a flowchart which shows the procedure at the time of manufacturing the dehumidification element by Embodiment 3 of this invention. It is a front view which shows the masking board used at the blasting process of FIG. FIG. 11 is a schematic enlarged view showing a state in which an injection flow is injected to the mesh material through the opening in a state where the masking plate of FIG. 10 is overlapped on the mesh material on which the oxide film is formed. It is a typical block diagram which shows the dehumidification element by Embodiment 4 of this invention. It is a front view which shows the mesh material which eliminated the plating film from the metal mesh for obtaining the anode electrode of FIG. It is sectional drawing which shows the mesh material in the area | region for a connection of FIG. It is sectional drawing which shows the mesh material in the area | region for non-connection of FIG. It is a flowchart which shows the procedure at the time of manufacturing the dehumidification element of FIG. FIG. 17 is a front view illustrating a plurality of masking plates that are used in the first to third masking process steps of FIG. 16 side by side. 1 is a perspective view showing a wet blasting apparatus used in a blasting process in Example 1. FIG. It is a table | surface which shows the average film thickness and plating efficiency in each of Examples 1-4 and Comparative Example 1.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a schematic configuration diagram showing a dehumidifying element according to Embodiment 1 of the present invention. The dehumidifying element 1 is an element that removes moisture in the air using an electrolysis reaction of water. The dehumidifying element 1 is applied to, for example, an optical device in which a lens is incorporated in a housing. As a specific example of the optical device, there is a surveillance camera for outdoor installation. When the dehumidifying element 1 is applied to an optical device, the dehumidifying element 1 performs dehumidification in the housing of the optical device, thereby preventing fogging of the lens of the optical device.

  The dehumidifying element 1 includes a solid polymer electrolyte membrane (hereinafter simply referred to as “electrolyte membrane”) 2, a cathode electrode 3 that is a porous electrode provided on one surface of the electrolyte membrane 2, an electrolyte membrane 2, and a cathode electrode 3 on the other side of the electrolyte membrane 2 in contact with the anode electrode 5 and the anode electrode 5 which is a porous electrode provided on the other surface of the electrolyte membrane 2. The anode side catalyst layer 6 is provided. The dehumidifying element 1 is installed with at least the anode-side catalyst layer 6 exposed to air in a casing that is a dehumidifying target (that is, air existing in a closed space).

  In the dehumidifying element 1, a DC power source 7 is connected between the cathode electrode 3 and the anode electrode 5 via a conducting wire 8. When the DC power source 7 is connected between the cathode electrode 3 and the anode electrode 5, the water electrolysis reaction represented by the formula (1) occurs in the anode side catalyst layer 6 and the water generation reaction represented by the formula (2). Occurs in the cathode-side catalyst layer 4.

2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ (1)
O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O (2)

  The dehumidifying element 1 is present in, for example, a housing by decomposing water in the air on the anode electrode 5 side by the reaction of the formula (1) and generating water on the cathode electrode 3 side by the reaction of the formula (2). Remove the water in the air to dehumidify the air.

  FIG. 2 is a front view showing the anode electrode 5 of FIG. A metal mesh is used for the anode electrode 5. The metal mesh is a porous body having a shape in which a plurality of strands 51 intersect and combine in a mesh shape. Each strand 51 is electrically connected at the intersection of each strand 51. A plurality of holes 52 surrounded by the respective strands 51 are formed in the metal mesh. Each hole 52 penetrates the metal mesh in the thickness direction of the metal mesh.

  As shown in FIG. 1, the anode electrode 5 that is a metal mesh is formed on the electrolyte membrane 2 in a state where one surface of the metal mesh is in contact with the electrolyte membrane 2 and the other surface of the metal mesh is exposed from the electrolyte membrane 2. Is provided. Thereby, in the cross section of each strand 51, a part of the outer peripheral portion of each strand 51 is in contact with the electrolyte membrane 2, and the remaining portion of the outer peripheral portion of each strand 51 is exposed from the electrolyte membrane 2. In this example, the anode electrode 5 is provided on the electrolyte membrane 2 in a state where a part of each strand 51 is buried in the electrolyte membrane 2.

  The anode catalyst layer 6 is a catalyst layer that promotes the reaction of the formula (1) on the anode electrode 5 side. The cathode side catalyst layer 4 is a catalyst layer that promotes the reaction of the formula (2) on the cathode electrode 3 side. The anode side catalyst layer 6 covers at least a part of the exposed surface of the anode electrode 5 (ie, metal mesh) from the electrolyte membrane 2.

FIG. 3 is a schematic configuration diagram illustrating a dehumidifying operation of the dehumidifying element 1 of FIG. Of e ⁻ , H ⁺ and O ₂ generated in the anode side catalyst layer 6 by the electrolysis reaction of the formula (1), electrons e ⁻ move to the anode electrode 5 via the anode side catalyst layer 6. The electrons e ^{− that} have reached the anode electrode 5 reach the conductor 8 through the respective strands 51 of the metal mesh, and move to the cathode electrode 3 through the conductor 8 and the DC power source 7.

On the other hand, among e ⁻ , H ⁺ , and O ₂ generated in the anode side catalyst layer 6, hydrogen ions H ⁺ pass through the holes 52 of the anode electrode 5 through the anode side catalyst layer 6, and then the electrolyte membrane 2. It passes through and reaches the cathode side catalyst layer 4. In the cathode side catalyst layer 4, electrons e ⁻ that have reached the cathode electrode 3 through the conductor 8 from the anode electrode 5, hydrogen ions H ⁺ that have reached the cathode side catalyst layer 4 through the electrolyte membrane 2, and in the air The reaction of formula (2) occurs with oxygen O ₂ to produce water. In this way, the dehumidifying operation of the dehumidifying element 1 is continued.

FIG. 4 is a schematic configuration diagram showing the behavior of electrons e ⁻ on the anode electrode 5 side in FIG. 3. Electrons e ⁻ generated in the anode side catalyst layer 6 by the reaction of the formula (1) move from the anode side catalyst layer 6 to the anode electrode 5 through the boundary between the anode side catalyst layer 6 and the anode electrode 5. Accordingly, only the portion of the outer surface of the anode electrode 5 that contacts the anode-side catalyst layer 6 functions as the electron e ⁻ movement path.

  As shown in FIG. 1, the metal mesh that is the anode electrode 5 includes a mesh material 9 made of metal, an oxide film 10 that covers the mesh material 9, and plating that covers the mesh material 9 while avoiding the oxide film 10. And a film 11. In the anode electrode 5, the plating film 11 covers the mesh material 9, so that the corrosion resistance of the portion of the outer surface of the anode electrode 5 that comes into contact with the anode-side catalyst layer 6 is higher than that of other portions.

  The metal composing the mesh material 9 is a conductive metal. Examples of the metal constituting the mesh material 9 include titanium Ti, aluminum Al, and iron Fe. In this example, titanium Ti is used as the metal constituting the mesh material 9. The shape of the mesh material 9 is a shape in which a plurality of fine metal wires are combined in a mesh shape. Thereby, the mesh material 9 is formed with a plurality of holes penetrating the mesh material 9 in the thickness direction of the mesh material 9.

  Further, as shown in FIG. 1, the outer surface of the mesh material 9 includes a first surface 91 covered with the oxide film 10 and a second surface 92 covered with the plating film 11. The positional relationship between the first surface 91 and the second surface 92 is such that when the second surface 92 is viewed from the front in the thickness direction of the mesh material 9, the first surface 91 is hidden behind the mesh material 9 itself and cannot be seen. It has become. That is, in the thickness direction of the mesh material 9, the surface of the mesh material 9 that can be seen from one side of the mesh material 9 is the first surface 91, and the surface of the mesh material 9 that is visible from the other side of the mesh material 9 is the second surface. A surface 92 is formed. The mesh material 9 is arranged with the first surface 91 facing the electrolyte membrane 2. In this example, of the outer surface of the mesh material 9, only the surface on the electrolyte membrane 2 side perpendicular to the thickness direction of the mesh material 9 is the first surface 91, and other surfaces including the inner surfaces of the holes 52 are A second surface 92 is formed.

  The oxide film 10 covering the first surface 91 is a film having an electrical insulation performance formed by oxidizing the metal constituting the mesh material 9. The anode electrode 5 is provided on the electrolyte membrane 2 in a state where the oxide film 10 is in contact with the electrolyte membrane 2.

  The plating film 11 covering the second surface 92 is a film made of a metal different from the metal constituting the mesh material 9. The metal constituting the plating film 11 is a metal having higher corrosion resistance than the metal constituting the mesh material 9. Examples of the metal constituting the plating film 11 include noble metals such as platinum Pt, gold Au, and palladium Pd. In this example, platinum Pt is used as the metal constituting the plating film 11. A part of the anode electrode 5 is exposed from the electrolyte membrane 2. The anticorrosion performance of the surface of the anode electrode 5 that contacts the anode catalyst layer 6 is that the second surface 92 of the mesh material 9 is covered with the plating film 11 so that the portion of the anode electrode 5 that contacts the electrolyte membrane 2 Is higher than.

  Next, a method for manufacturing the dehumidifying element 1 will be described. FIG. 5 is a flowchart for explaining the procedure for manufacturing the dehumidifying element 1 of FIG. Since the metal mesh used as the anode electrode 5 is manufactured in advance when the dehumidifying element 1 is manufactured, the manufacturing method of the metal mesh used as the anode electrode 5 is first described, and then the manufacturing method of the dehumidifying element 1 is described. . As shown in FIG. 5, the metal mesh manufacturing method includes a heat treatment step, a degreasing step, a blasting step, an ultrasonic cleaning step, an acid treatment step, and a plating step.

(Heat treatment process)
When manufacturing a metal mesh, first, a mesh material 9 having a shape in which a plurality of fine metal wires intersect and combine in a mesh shape is heated in an air atmosphere. As a result, an oxide film 10 covering the entire outer surface of the mesh material 9 is formed on the mesh material 9. For example, the thickness of the oxide film 10 can be grown to about 1 μm by performing heat treatment on the mesh material 9 at 700 ° C. for 2 hours.

(Degreasing process)
Thereafter, dirt (that is, inorganic foreign matter and organic foreign matter) adhering to the surface of the oxide film 10 covering the entire outer surface of the mesh material 9 is removed using a degreasing liquid. At this time, since the oxide film 10 is formed on the mesh material 9, the dirt is cleaned and removed from the oxide film 10 by the immersion degreasing method without using the electrolytic degreasing method. As the degreasing liquid, for example, a known degreasing liquid containing 0.5 to 1 wt% sodium orthosilicate, 0.5 wt% sodium carbonate, 5 wt% sodium hydroxide, or the like can be used. In addition, “wt%” is a weight ratio with respect to the adjusted mixed liquid as a whole. The temperature and the immersion time as the degreasing conditions can be set as appropriate in order to obtain an appropriate cleanliness of the surface of the oxide film 10. For example, dirt such as oil on the surface of the oxide film 10 can be removed by performing immersion degreasing with the temperature of the degreasing liquid being 80 ° C. and the immersion time being 5 minutes.

(Blasting process)
Thereafter, a part of the oxide film 10 covering the entire outer surface of the mesh material 9 is removed from the mesh material 9 by wet blasting. In wet blasting, the mesh material 9 covered with the oxide film 10 is fixed by a fixture, and a slurry formed by mixing abrasive grains (abrasive) and water is sprayed from the nozzle onto the mesh material 9 as a jet stream. Then, a part of the oxide film 10 is removed. Known abrasive grains are used as the abrasive grains. For example, polygonal alumina particles having a particle diameter of 20 μm are used as abrasive grains, and a mixed solution obtained by diluting abrasive grains to 10 vol% with pure water is used as a slurry.

  In this example, an oxide film formed in all regions visible from one side of the mesh material 9 by injecting slurry onto the mesh material 9 from one side of the mesh material 9 in the thickness direction of the mesh material 9 10 is removed. As a result, the oxide film 10 formed in the region on the back side of the mesh material 9 that cannot be seen from one side of the mesh material 9 is left on the outer surface of the mesh material 9. Of the outer surface of the mesh material 9, the surface exposed by removing the oxide film 10 by wet blasting becomes the second surface 92, and the surface covered with the oxide film 10 remaining without being removed by wet blasting is the first surface. It becomes surface 91. The second surface 92 of the mesh material 9 is rougher than the first surface 91 due to the effect of removing the oxide film 10 by wet blasting.

(Ultrasonic cleaning process)
When the blasting process is performed on the surface of the mesh material 9, a part of the foreign matter generated in the blasting process (for example, a part of the oxide film 10, the mesh material 9, or abrasive grains) adheres. Therefore, after the blasting process, the foreign matter adhering to the surface of the mesh material 9 in the blasting process is removed from the surface of the mesh material 9 by ultrasonic cleaning. As the liquid that conducts ultrasonic waves, for example, an organic solvent such as acetone or ethanol can be used. For example, by setting the frequency at the time of ultrasonic cleaning to 35 kHz and processing at 25 ° C. for 5 minutes, the deposits on the surface of the mesh material 9 can be removed.

(Acid treatment process)
After the blasting process, the second surface 92 of the mesh material 9 exposed by removing the oxide film 10 including the time of the ultrasonic cleaning process is exposed to the atmosphere, so that after the oxide film 10 is removed An oxide film is regenerated on the outer surface of the mesh material 9, that is, the second surface 92. Therefore, after the ultrasonic cleaning process, the regenerated oxide film is removed from the second surface 92 which is a part of the outer surface of the mesh material 9 by the acid cleaning liquid. Specifically, the productive oxide film is removed from the outer surface of the mesh material 9 by immersing the mesh material 9 on which the regenerated oxide film is formed in an acid cleaning solution. A known acid cleaning liquid is used as the acid cleaning liquid. For example, an acid cleaning solution containing 5 wt% ammonium acid fluoride, 1 wt% organic acids, 30 wt% hydrochloric acid, or the like can be used. This treatment process is a process performed to remove the regenerated oxide film having a thickness of several nanometers regenerated on the outer surface of the mesh material 9 between the blast treatment process and the start of this treatment process. Therefore, it is to be avoided that the oxide film 10 formed on the first surface 91 of the mesh material 9 that does not require coating with the plating film 11 is completely removed in this processing step. For this reason, the immersion time of the mesh material 9 with respect to the acid cleaning liquid in this treatment step is limited to a very short time (for example, 3 seconds to 10 seconds).

(Plating process)
Thereafter, the plating material 11 is formed on the second surface 91 of the outer surface of the mesh material 9 from which the oxide film has been removed by immersing the mesh material 9 in the plating solution and energizing it. In this step, for example, a plating solution containing 3% water-soluble platinum salt as Pt in 10 wt% sulfuric acid can be used. The plating conditions can be appropriately set according to the required thickness of the plating film 11. In this step, the plating film 11 is not formed on the oxide film 10 having electrical insulation performance, and the plating film 11 is formed by selecting the second surface 92 from which the mesh material 9 is exposed. In this way, a metal mesh used as the anode electrode 5 is completed.

  In addition, between each process of said heat processing process, a degreasing process, a blasting process, an ultrasonic cleaning process, an acid treatment process, and a plating process, while meshing the mesh material 9 in a pure water, the surface of the mesh material 9 There is a water washing process in which the treatment liquid adhering to the water is washed away. The washing process is performed in order to prevent the processing liquid used in the previous process from being brought into the next process. The treatment temperature for the water washing treatment is not particularly required and may be about the same as room temperature. Further, the treatment time of the water washing treatment is preferably within one minute because the oxide film is regenerated on the outer surface of the mesh material 9 in water simultaneously with the water washing of the mesh material 9.

  Next, a method for manufacturing the dehumidifying element 1 will be described. The manufacturing method of the dehumidifying element 1 includes a pressing step and an anode side catalyst layer forming step. When the dehumidifying element 1 is manufactured, the metal mesh manufactured by the above method is prepared in advance as the anode electrode 5.

(Pressing process)
FIG. 6 is a schematic configuration diagram showing the stacking order of the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 of FIG. When the dehumidifying element 1 is manufactured, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 are laminated in this order from the bottom to the top, and in this state, the laminate is obtained by hot pressing up and down. At this time, the metal mesh that is the anode electrode 5 is laminated on the electrolyte membrane 2 in a state where the oxide film 10 is in contact with the electrolyte membrane 2 and at least a part of the plating film 11 is exposed from the electrolyte membrane 2. For example, Nafion (registered trademark) manufactured by DuPont is used as the electrolyte membrane 2. The cathode side catalyst layer 4 is made of, for example, platinum Pt fine powder, and the cathode electrode 3 is made of, for example, carbon paper. As conditions for hot pressing, for example, the temperature is 190 ° C., the press load is 150 kgf / cm ² , and the press holding time is 5 minutes.

(Anode-side catalyst layer forming step)
After the pressing step, a catalyst is applied to the surface of the anode electrode 5 that is a metal mesh, thereby providing the electrolyte membrane 2 with an anode-side catalyst layer 6 that covers at least a part of the exposed surface of the anode electrode 5 from the electrolyte membrane 2. Thereby, the anode side catalyst layer 6 is held by the electrolyte membrane 2 in a state in which only the plating film 11 is in contact with the oxide film 10 and the plating film 11 of the anode electrode 5. As the catalyst constituting the anode catalyst layer 6, for example, carbon powder carrying platinum Pt can be used. As a method for applying the catalyst, for example, the catalyst is applied to the exposed surface of the anode electrode 5 using an application robot so that the thickness of the anode-side catalyst layer 6 from the exposed surface of the anode electrode 5 is 30 μm. In this way, the dehumidifying element 1 is manufactured.

  The dehumidifying element 1 performs a dehumidifying operation as a dehumidifier by processing it to a required size according to the required dehumidifying capacity and connecting the DC power source 7 between the cathode electrode 3 and the anode electrode 5.

  In such a metal mesh, in the thickness direction of the mesh material 9, the surface of the mesh material 9 that can be seen from one side of the mesh material 9 is a first surface 91, and the mesh material 9 that can be seen from the other side of the mesh material 9. This surface is the second surface 92, and the oxide film 10 formed by oxidizing the metal constituting the mesh material 9 covers the first surface 91 of the mesh material 9 and is different from the metal constituting the mesh material 9. Since the plating film 11 made of metal covers the second surface 92 of the mesh material 9, even if the mesh material 9 is formed with a plurality of holes, the oxide film 10 having electrical insulation performance is used as the mesh material. By selectively forming on the outer surface 9 and performing electroplating, the plating film 11 can be formed while avoiding the oxide film 10. Further, the selective formation of the oxide film 10 on the outer surface of the mesh material 9 can be easily and more accurately performed by blasting the mesh material 9 having the oxide film formed on the entire outer surface. Therefore, the plating film 11 can be easily and more accurately formed on a necessary portion of the mesh material 9, and the amount of metal used to form the plating film 11 can be reduced to reduce the cost.

  In such a dehumidifying element 1, the metal mesh can be used as the anode electrode 5 by bringing the metal mesh oxide film 10 into contact with the electrolyte film 2. Thereby, formation of the plating film 11 in the area | region where the corrosion resistance performance of the anode electrode 5 is unnecessary can be suppressed easily, and the usage-amount of the plating film 11 comprised with the expensive metal with high corrosion resistance performance is reduced. be able to. Therefore, the cost can be reduced.

  In the method of manufacturing the metal mesh and dehumidifying element 1, the mesh material 9 is heat-treated to form an oxide film on the outer surface of the mesh material 9, and then a part of the oxide film formed on the outer surface of the mesh material 9 is wet-blasted. Since the plating film 11 is formed on the exposed surface of the mesh material 9 exposed by the removal of the oxide film, even if the mesh material 9 has a plurality of holes, the plating film 11 is oxidized to an unnecessary region. The film 10 can be easily formed by wet blasting, and the plating film 11 can be formed on the outer surface of the mesh material 9 while avoiding the oxide film 10. As a result, the plating film 11 can be easily and more accurately provided on a necessary portion of the outer surface of the mesh material 9, and the amount of metal constituting the plating film 11 can be reduced to reduce the cost. .

  Further, after a part of the oxide film formed on the outer surface of the mesh material 9 is removed by wet blasting and before the plating film 11 is formed on the exposed surface of the mesh material 9, deposits adhered to the outer surface of the mesh material 9 Since the regenerated oxide film regenerated on the outer surface of the mesh material 9 is removed by acid treatment, the exposed surface of the mesh material 9 exposed by removing the oxide film by wet blasting is applied to the plating film. 11 can be easily formed, and the plating film 11 can be more reliably formed.

Embodiment 2. FIG.
FIG. 7 is a flowchart showing a procedure for manufacturing the dehumidifying element 1 according to the second embodiment of the present invention. The procedure of the manufacturing method of the dehumidifying element 1 in the present embodiment is a procedure in which the ultrasonic cleaning process and the acid treatment process are eliminated in the manufacturing method of the dehumidifying element 1 in the first embodiment. That is, in the manufacturing method of the dehumidifying element 1, as shown in FIG. 7, after performing the metal mesh manufacturing method including the heat treatment step, the degreasing step, the blasting step, and the plating step, the pressing step, the anode side catalyst layer forming step I do.

  In the manufacturing method of a metal mesh, after performing a blasting process, a plating process is performed as it is. In this method, since the ultrasonic cleaning process and the acid treatment process are not performed, in the plating process, foreign matter (for example, oxide film, removed material of the mesh material 9 or abrasive grains) adhered to the outer surface of the mesh material 9 in the blasting process. Is left on the outer surface of the mesh material 9, and the plating film 11 is formed on the exposed surface of the mesh material 9.

  In the present embodiment, since the plating process is performed as it is after the blasting process, the shape of the abrasive grains contained in the slurry in the blasting process is preferably a sphere that is unlikely to remain on the outer surface of the mesh material 9. Moreover, it is preferable to make the density | concentration of the abrasive grain in the slurry used at a blasting process low. For example, spherical alumina particles having a particle diameter of 20 μm are used as abrasive grains, and a mixed solution obtained by diluting the abrasive grains with water to 3 vol% is used as a slurry. Other steps in the method of manufacturing the metal mesh and the dehumidifying element 1 are the same as those in the first embodiment.

  In such a manufacturing method of the metal mesh and the dehumidifying element 1, the ultrasonic cleaning step and the acid treatment step are omitted, and the plating step is performed as it is after the blast treatment step, so that the number of steps can be reduced, The productivity of the dehumidifying element 1 can be improved.

Embodiment 3 FIG.
When the metal mesh is punched in a specific region to obtain the anode electrode of the dehumidifying element, the metal mesh portion other than the specific region is a portion that does not require formation of a plating film. In the present embodiment, the plating film is formed only in a specific region of the metal mesh that becomes the anode electrode.

  FIG. 8 is a front view showing a mesh material 9 obtained by removing the plating film from the metal mesh according to the third embodiment of the present invention. FIG. 8 shows the mesh material 9 when the second surface 92 is viewed from the outside of the mesh material 9 along the thickness direction of the mesh material 9. Of the metal mesh, the portion used as the anode electrode 5 of the dehumidifying element 1 is only the portion in the plurality of regions 21 in FIG. In this example, the shape of each region 21 is circular.

  The second surface 92 of the mesh material 9 is divided into a plating region that is each region 21 used for the anode electrode 5 and a non-plating region that is a region 22 other than each region 21. The oxide film 10 covers the first surface 91 of the mesh material 9 and the non-plating region 22. The plating film 11 covers the plating region 21 of the mesh material 9. Other configurations are the same as those in the first embodiment.

  Next, a method for manufacturing the dehumidifying element 1 will be described. FIG. 9 is a flowchart showing a procedure for manufacturing a dehumidifying element according to Embodiment 3 of the present invention. In the manufacturing method of the dehumidifying element 1, after performing the manufacturing method of the metal mesh including a heat treatment process, a degreasing process, a blasting process, an ultrasonic cleaning process, an acid treatment process, and a plating process, an anode electrode 5 is obtained by a punching process. Then, the pressing step and the anode side catalyst layer forming step are sequentially performed.

  When manufacturing a metal mesh, after performing the heat treatment process and the degreasing process similar to Embodiment 1, the blasting process is performed. The blasting process includes a masking process using a masking plate provided with a plurality of openings.

  FIG. 10 is a front view showing a masking plate used in the blasting process of FIG. The masking plate 23 is provided with a plurality of openings 24 corresponding to the plating regions 21 where the plating film 11 needs to be formed. Therefore, in this example, the shape of the opening 24 is circular.

  In the blasting process, the mesh material 9 and the masking plate 23 are fixed in the blasting apparatus in a state where the masking plate 23 is superimposed on the mesh material 9. As the masking plate 23, for example, a square-shaped copper Cu metal plate having a plurality of circular openings 24 and having a length of 120 mm, a width of 120 mm, and a thickness of 0.3 mm is used. The dimensions of the masking plate 23 other than the thickness are made equal to the dimensions of the mesh material 9, and the masking plate 23 is overlaid on the mesh material 9 so that the end of the masking plate 23 and the end of the mesh material 9 are aligned.

  In the blasting process, the same slurry as in the first embodiment is sprayed from the nozzles through the openings 24 to the mesh material 9 with the masking plate 23 superimposed on the second surface 92 side of the mesh material 9. Thus, part of the oxide film 10 is removed from the mesh material 9. As a result, the oxide film is removed in each plating region 21 to expose the mesh material 9, and the oxide film remains covered with the mesh material 9 in the non-plating region 22.

  In the blasting process, since the slurry containing the abrasive grains is also jetted as a jet flow onto the masking plate 23, the fine pieces generated from the masking plate 23 by the jet flow adhere to the outer surface of the mesh material 9. Since deposits are removed by the ultrasonic cleaning process and the acid treatment process after the process, there is no problem.

  Here, FIG. 11 is a schematic diagram showing a state in which a jet flow is jetted to the mesh material 9 through the opening 24 in a state where the masking plate 23 of FIG. 10 is superimposed on the mesh material 9 on which the oxide film 10 is formed. It is an enlarged view. When the direction of the jet flow 25 is not parallel to the thickness direction of the masking plate 23, the portion of the oxide film 10 located on the inner peripheral portion of the opening 24 is not removed as shown in FIG. It will remain on the outside. Therefore, in order to more reliably secure the plating region 21 where the plating film needs to be formed, it is preferable to make the size of the opening 24 larger than the plating region 21.

  Thereafter, by performing the same ultrasonic cleaning process, acid treatment process and plating process as in the first embodiment, the plating film 11 is formed in each plating region 21 of the second surface 92 of the outer surface of the mesh material 9. Thus, a metal mesh in which the oxide film 10 is formed on the non-plated region 22 and the first surface 91 of the second surface 92 is obtained.

  Thereafter, a plurality of anode electrodes 5 are obtained by punching each plating region 21 of the metal mesh (punching step).

  Thereafter, in the same manner as in the first embodiment, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2, and the anode electrode 5 obtained from the metal mesh are laminated in this order, and hot pressing is performed in this state to form the laminated body. obtain. At this time, the anode electrode 5 is overlaid on the electrolyte membrane 2 in a state where the oxide film 10 is in contact with the electrolyte membrane 2 and at least a part of the plating film 11 is exposed from the electrolyte membrane 2 (pressing process).

  Then, the dehumidification element 1 is manufactured by performing the anode side catalyst layer formation process similar to Embodiment 1. FIG. Other steps in the method of manufacturing the metal mesh and the dehumidifying element 1 are the same as those in the first embodiment.

  In such a metal mesh, the second surface 92 of the mesh material 9 is divided into the plating region 21 and the non-plating region 22, and the oxide film 10 covers the first surface 91 and the non-plating region 22. Since 11 covers the plating region 21, the plating film 11 can be formed in accordance with a necessary region, and the amount of the metal constituting the plating film 11 can be further reduced. Thereby, cost can be further reduced.

  Further, in such a metal mesh manufacturing method, there is a masking process step in which the masking plate 23 provided with the opening 24 is overlapped on the mesh material 9 and the slurry is jetted into the mesh material 9 through the opening 24 as an injection flow. Since it is included in the blasting process, the oxide film 10 can be removed only in the plating region 21 of the plating region 21 and the non-plating region 22 on the second surface 92. Thereby, the plating film 11 can be more reliably formed only in the plating region 21 of the second surface 92 of the mesh material 9.

  In such a method of manufacturing the dehumidifying element 1, a metal mesh in which the plating film 11 covers the plating region 21 of the plating region 21 and the non-plating region 22 on the second surface 92 is manufactured. Since the anode electrode 5 is obtained by punching out, the shape of the anode electrode 5 can be selected in accordance with a necessary shape such as the shape of the dehumidifying element 1. Further, by setting a plurality of plating regions 21 on one metal mesh, a plurality of anode electrodes 5 can be obtained from one metal mesh. Thereby, the productivity of the anode electrode 5 can be improved.

Embodiment 4 FIG.
FIG. 12 is a schematic configuration diagram showing a dehumidifying element according to Embodiment 4 of the present invention. An electrode 81 for electrically connecting the conductive wire 8 and the anode electrode 5 is attached to the plating film 11 of the anode electrode 5. The plating film 11 of the anode electrode 5 plays a role of ensuring conductivity between the mesh material 9 and the conductive wire 8 in a certain connection region 26 including the attachment portion of the electrode 81, and a non-connection region other than the connection region 26. 27 contributes to the dehumidification reaction. Accordingly, the smaller the surface area of the plating film 11 in the connection region 26 is, the better the progress of oxidation is, and the larger the surface area of the plating film 11 in the non-connection region 27 is, the more the reaction area increases and the dehumidification amount increases. In the present embodiment, the roughness of the surface of the mesh material 9 with which the plating film 11 contacts is larger in the non-connection region 27 than in the connection region 26. Thereby, in the present embodiment, the surface area of the plating film 11 is larger in the non-connection region 27 than in the connection region 26.

  FIG. 13 is a front view showing a mesh material obtained by removing the plating film 11 from the metal mesh for obtaining the anode electrode 5 of FIG. In FIG. 13, the mesh material 9 is shown when the second surface 92 is viewed from the outside of the mesh material 9 along the thickness direction of the mesh material 9. Similarly to the third embodiment, the second surface 92 of the mesh material 9 is divided into a plurality of plating regions 21 used for the anode electrode 5 and non-plating regions 22 other than the plating regions 21. The oxide film 10 covers the first surface 91 of the mesh material 9 and the non-plating region 22. The plating film 11 covers the plating region 21 of the mesh material 9.

  Each plating region 21 is divided into a connection region 26 and a non-connection region 27. In this example, the outer peripheral region of the circular plating region 21 is a connection region 26, and the region surrounded by the connection region 26 is a non-connection region 27.

  14 is a cross-sectional view showing the mesh material 9 in the connection region 26 of FIG. 13, and FIG. 15 is a cross-sectional view showing the mesh material 9 in the non-connection region 27 of FIG. As shown in FIGS. 14 and 15, the roughness of the second surface 92 of the mesh material 9 is larger in the non-connection region 27 than in the connection region 26. As a result, the surface area of the plating film 11 covering the mesh material 9 in the non-connection region 27 is larger than the surface area of the plating film 11 covering the mesh material 9 in the connection region 26. Other configurations are the same as those in the first embodiment.

  Next, a method for manufacturing the dehumidifying element 1 will be described. FIG. 16 is a flowchart showing a procedure for manufacturing the dehumidifying element of FIG. In the manufacturing method of the dehumidifying element 1, after performing the manufacturing method of the metal mesh including a heat treatment process, a degreasing process, a blasting process, an ultrasonic cleaning process, an acid treatment process, and a plating process, an anode electrode 5 is obtained by a punching process. Then, the pressing step and the anode side catalyst layer forming step are sequentially performed.

  When manufacturing a metal mesh, after performing the heat treatment process and the degreasing process similar to Embodiment 1, the blasting process is performed. The blasting process includes a masking process using a masking plate provided with a plurality of openings a plurality of times. In this example, the first to third masking processes are sequentially performed in the blasting process.

  In the first to third masking processes, the masking plate 23 is overlapped on the second surface 92 side of the mesh material 9, and the mesh material 9 is passed through each opening of the masking plate as a jet flow from the nozzle. A part of the oxide film 10 is removed from the mesh material 9 by spraying. As a result, the oxide film is removed in each plating region 21 to expose the mesh material 9, and the oxide film remains covered with the mesh material 9 in the non-plating region 22. In the first to third masking process steps, the type of the masking plate and the type of the slurry (that is, the jet flow) are changed, and the slurry is jetted onto the mesh material 9 as the jet flow through each opening of the masking plate. .

  FIG. 17 is a front view showing a plurality of masking plates used in the first to third masking processes in FIG. 16 side by side, and FIG. 17A is used in the first masking process. FIG. 17B is a diagram showing a masking plate, FIG. 17B is a diagram showing a masking plate used in the second masking process, and FIG. 17C is a diagram showing a masking plate used in the third masking process. is there.

  When comparing the masking plates 23a to 23c used in the first to third masking processes, the outer shapes of the masking plates 23a to 23c are the same, but the shapes and positions of the openings 24a to 24c are the same. Is different. Each opening part 24a-24c is arrange | positioned according to each of the division area | region which divided the plating area | region 21 into three. In this example, the circular plating region 21 is divided into three regions: an outer periphery upper region and a lower outer periphery region to be the connection region 26, and a central region to be the non-connection region 27, and the first masking process step The position of the opening 24a of the masking plate 23a used in the above is set according to the central area, the position of the opening 24b of the masking plate 23b used in the second masking process step is set according to the upper peripheral area, The position of the opening 24c of the masking plate 23c used in the third masking process is set in accordance with the lower peripheral area. That is, the positions of the openings 24a to 24c with respect to the mesh material 9 in a state where the masking plates 23a to 23c used in the first to third masking process steps are overlapped with the mesh material 9 are different from each other. .

  In the first to third masking processing steps, the mesh material 9 and the masking plates 23a to 23c are fixed in the blasting apparatus in a state where the masking plates 23a to 23c are superposed on the mesh material 9 while changing each step. As the masking plates 23a to 23c, for example, square-shaped copper Cu metal plates having a length of 120 mm, a width of 120 mm, and a thickness of 0.3 mm, in which the shapes and positions of the openings 24a to 24c are changed, are used. The dimensions of the masking plates 23a to 23c other than the thickness are made equal to the dimensions of the mesh material 9, and the masking plate is attached to the mesh material 9 so that the end portions of the masking plates 23a to 23c are aligned with the end portions of the mesh material 9. 23.

  Comparing the slurries used in the first to third masking processes, the compositions of the abrasive grains and the slurries contained in the slurries are different. In this example, the type of slurry used in the second and third masking processes is the same, and the type of slurry used in the first masking process is the second and third masking processes. It differs from the type of slurry used in the process.

  The roughness (surface area) of the exposed surface of the mesh material 9 after removing the oxide film 10 by spraying the slurry is strongly influenced by the shape of the abrasive grains contained in the slurry. That is, when the shape of the abrasive grains contained in the slurry is a polygonal shape, the exposed surface of the mesh material 9 becomes sharp and the roughness increases, and the shape of the abrasive grains contained in the slurry becomes spherical. In this case, the state of the exposed surface of the mesh material 9 becomes a dimple state, and the roughness becomes smaller than that in the case of polygonal abrasive grains. In this example, a slurry containing polygonal abrasive grains is used in the first masking process, and a slurry containing spherical abrasive grains is used in the second and third masking processes.

  In this example, a slurry obtained by diluting alumina particles, which are polygonal abrasive grains having a particle diameter of 20 μm, to 10 vol% with pure water in a state where the masking plate 23 a is overlapped on the mesh material 9 in the blasting process. The oxide film 10 is removed in the central region of the plating region 21 (first masking process step), and then the particle size is changed in a state where the masking plate 23b is superposed on the mesh material 9 instead of the masking plate 23a. A slurry obtained by diluting alumina particles, which are 20 μm spherical abrasive grains, to 10 vol% with pure water is sprayed onto the mesh material 9 to remove the oxide film 10 in the region on the outer periphery of the plating region 21 (second masking step). Then, in the state where the masking plate 23c is superposed on the mesh material 9 instead of the masking plate 23b, the same slurry as that in the previous step is sprayed onto the mesh material 9 to thereby produce the plating region 21. The oxide film 10 is removed in the region below the outer periphery (third masking process step). As a result, as shown in FIG. 14, the connection region 26 in which the surface unevenness is eliminated and the surface area is reduced as shown in FIG. 14, and the surface unevenness is sharpened as shown in FIG. A non-connection region 27 having a surface area larger than that of the use region 26 is formed in the plating region 21 of the mesh material 9. Other steps in the method of manufacturing the metal mesh and the dehumidifying element 1 are the same as those in the third embodiment.

  In such a metal mesh manufacturing method, a plurality of masking processes are included in the blasting process, and the positions of the openings 24a to 24c with respect to the mesh material 9 in a state where the masking plates 23a to 23c are superimposed on the mesh material 9 Since the jet flow injected into the mesh material 9, that is, the type of slurry is different in each masking process, the surface state of the mesh material 9 in a plurality of regions divided in the plating region 21 is made different. Can do. Thereby, the surface state in the plating area | region 21 of the mesh material 9 can be made into the surface state according to the partial use in the plating area | region 21. FIG. For example, when the anode electrode 5 obtained by punching a metal mesh in the plating region 21 is used as a dehumidifying element, the mesh material 9 and the plating film 11 are composed of a portion where the conductor 8 is connected and a portion which mainly performs a dehumidifying reaction. The surface area can be set appropriately.

  In the above example, three masking processes are included in the blasting process, but the number of masking processes is not limited to this, and two masking processes may be included in the blasting process. Alternatively, four or more masking processes may be included in the blasting process. In this case, in at least one of the masking processes, the position of the opening with respect to the mesh material 9 in a state where the masking plate is overlapped with the mesh material 9 and the type of the jet flow injected to the mesh material 9 are different from each other. Different from the masking process.

  Moreover, in each said embodiment, although the metal which comprises the mesh material 9 is titanium Ti, aluminum Al, iron Fe, etc. may be sufficient, for example.

  Moreover, in each said embodiment, although the metal which comprises the plating film 11 is platinum Pt, gold | metal | money Au, palladium Pd etc. may be sufficient, for example.

  In each of the above embodiments, wet blasting, in which a slurry in which abrasive grains and water are mixed is sprayed onto the mesh material 9 as an injection flow to remove a portion of the oxide film from the mesh material 9, is applied to the blasting process. However, dry blasting in which abrasive grains are jetted onto the mesh material 9 together with air as a jet flow to remove a part of the oxide film from the mesh material 9 may be applied to the blasting process.

  Further, the mesh material 9 may be produced by knitting a plurality of metal yarns, or may be produced by forming a plurality of holes in a single metal plate.

  Next, a dehumidifying element according to Examples 1 to 4 corresponding to Embodiments 1 to 4 and a comparative example for comparison with Examples 1 to 4 will be described.

Example 1.
A mesh material 9 made of pure titanium Ti having a line width of 100 μm and a thickness of 50 μm and made of fine metal wires having a length of 120 mm and a width of 120 mm is processed by the method described in the first embodiment to manufacture the anode electrode 5. A dehumidifying element was manufactured using this anode electrode 5. An electric furnace was used for the heat treatment in the heat treatment step, and the mesh material 9 made of pure titanium Ti was put in the furnace, heated to 700 ° C., and held for 2 hours. Thereafter, the temperature holding was stopped and the temperature was cooled to 25 ° C., and the atmosphere in the furnace was the same as the atmosphere. Thereafter, the mesh material 9 is taken out from the furnace, washed with pure water for 1 minute, and then degreased composed of 1 wt% sodium orthosilicate, 5 wt% sodium carbonate, 5 wt% sodium hydroxide, 89 wt% pure water. It was immersed in the liquid for 5 minutes. The temperature of the degreasing solution was 80 ° C. Thereafter, the mesh material 9 was taken out from the degreasing liquid, washed with pure water for 1 minute, and then held in a wet blasting apparatus. The slurry used for wet blasting was prepared by dissolving polygonal alumina particles having a particle diameter of 20 μm in pure water at a concentration of 10 vol%.

FIG. 18 is a perspective view showing the wet blasting apparatus used in the blasting process in the first embodiment. As shown in FIG. 18, when performing wet blasting in which slurry is sprayed onto the mesh material 9, both ends in the width direction of the mesh material 9 are held by the pair of fixtures 43, and the mesh material 9 is held horizontally. Slurry is jetted downward as a jet stream 42 from a nozzle 41 arranged above 9. The vertical distance between the nozzle 41 and the mesh material 9 is 10 mm, and while the slurry is sprayed onto the mesh material 9 at a pressure of 0.3 MPa / cm ² , it starts to move horizontally from the point A, and turns back at the point B. The reciprocating operation for returning to point A was repeated 5 times. The moving speed of the nozzle 41 in this operation was 10 mm / sec.

  Thereafter, the mesh material 9 was taken out from the wet blasting apparatus, washed with pure water for 1 minute, and then the mesh material 9 was subjected to ultrasonic cleaning. The liquid that conducts ultrasonic waves was acetone, the frequency at the time of washing was 35 kHz, and the treatment was performed at 25 ° C. for 5 minutes. Thereafter, the mesh material 9 was taken out from acetone, washed with pure water for 1 minute, and then immersed in an acid active solution for 5 seconds. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material 9 was taken out from the acid-activated liquid and washed with pure water for 1 minute, and then the mesh material 9 was immersed in the plating solution and subjected to an energization treatment for 10 minutes at a current of 5A. Platinum plating S (made by Asahi Yushi Co., Ltd.) was used for the plating solution. Then, it washed with pure water for 1 minute, and manufactured the metal mesh in which the platinum plating film was given to the mesh material 9.

Using the metal mesh produced by the above method as the anode electrode 5, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 were laminated and pressed at 190 ° C. and 50 kgf / cm ² for 5 minutes. At this time, the surface of the anode electrode 5 on which the plating film was applied was made to be a surface in contact with the outside air toward the opposite side of the electrolyte membrane 2. The electrolyte membrane 2 was a DuPont solid polymer electrolyte membrane (Nafion), the cathode catalyst layer 4 was platinum Pt fine powder, and the cathode electrode was carbon paper. Thereafter, carbon powder carrying platinum Pt on the exposed surface of the anode electrode 5 was applied to a thickness of about 30 μm using a coating robot. The dehumidifying element obtained by the above method was punched out using a press machine, and an electrode serving as a contact point with an external DC power source was fixed and attached with a resin casing.

Example 2
A mesh material 9 made of pure titanium Ti having a line width of 100 μm and a thickness of 50 μm and made of fine metal wires having a length of 120 mm and a width of 120 mm is processed by the method described in the second embodiment to manufacture the anode electrode 5. A dehumidifying element was manufactured using this anode electrode 5. An electric furnace was used for the heat treatment in the heat treatment step, and the mesh material 9 made of pure titanium Ti was put in the furnace, heated to 700 ° C., and held for 2 hours. Thereafter, the temperature holding was stopped and the temperature was cooled to 25 ° C., and the atmosphere in the furnace was the same as the atmosphere. Thereafter, the mesh material 9 is taken out from the furnace, washed with pure water for 1 minute, and then degreased composed of 1 wt% sodium orthosilicate, 5 wt% sodium carbonate, 5 wt% sodium hydroxide, 89 wt% pure water. It was immersed in the liquid for 5 minutes. The temperature of the degreasing solution was 80 ° C. Thereafter, the mesh material 9 was taken out from the degreasing liquid, washed with pure water for 1 minute, and then held in a wet blasting apparatus. The slurry used for wet blasting was prepared by dissolving spherical alumina particles having a particle diameter of 20 μm in water at a concentration of 3 vol%.

In the blasting process, as in Example 1, the mesh material 9 was arranged at the position shown in FIG. 18, and the slurry was jetted downward as the jet flow 42 from the nozzle 41 arranged above the mesh material 9. The vertical distance between the nozzle 41 and the mesh material 9 is 10 mm, and while the slurry is sprayed onto the mesh material 9 at a pressure of 0.3 MPa / cm ² , it starts to move horizontally from the point A, and turns back at the point B. The reciprocating motion returning to point A was repeated 10 times. The moving speed of the nozzle 41 in this operation was 20 mm / sec.

  Thereafter, the mesh material 9 was taken out from the wet blasting apparatus, washed with pure water for 1 minute, and then immersed in an acid active solution for 5 seconds. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material 9 was taken out from the acid-activated liquid and washed with pure water for 1 minute, and then the mesh material 9 was immersed in the plating solution and subjected to an energization treatment for 10 minutes at a current of 5A. Platinum plating S (made by Asahi Yushi Co., Ltd.) was used for the plating solution. Then, it washed with pure water for 1 minute, and manufactured the metal mesh in which the platinum plating film was given to the mesh material 9.

Using the metal mesh produced by the above method as the anode electrode 5, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 were laminated and pressed at 190 ° C. and 50 kgf / cm ² for 5 minutes. At this time, the surface of the anode electrode 5 on which the plating film was applied was made to be a surface in contact with the outside air toward the opposite side of the electrolyte membrane 2. The electrolyte membrane 2 was a DuPont solid polymer electrolyte membrane (Nafion), the cathode catalyst layer 4 was platinum Pt fine powder, and the cathode electrode was carbon paper. Thereafter, carbon powder carrying platinum Pt on the exposed surface of the anode electrode 5 was applied to a thickness of about 30 μm using a coating robot. The dehumidifying element obtained by the above method was punched out using a press machine, and an electrode serving as a contact point with an external DC power source was fixed and attached with a resin casing.

Example 3
A mesh material 9 made of pure titanium Ti having a line width of 100 μm and a thickness of 50 μm and made of fine metal wires having a length of 120 mm and a width of 120 mm is processed by the method described in the second embodiment to manufacture the anode electrode 5. A dehumidifying element was manufactured using this anode electrode 5. An electric furnace was used for the heat treatment in the heat treatment step, and the mesh material 9 made of pure titanium Ti was put in the furnace, heated to 700 ° C., and held for 2 hours. Thereafter, the temperature holding was stopped and the temperature was cooled to 25 ° C., and the atmosphere in the furnace was the same as the atmosphere. Thereafter, the mesh material 9 is taken out from the furnace, washed with pure water for 1 minute, and then degreased composed of 1 wt% sodium orthosilicate, 5 wt% sodium carbonate, 5 wt% sodium hydroxide, 89 wt% pure water. It was immersed in the liquid for 5 minutes. The temperature of the degreasing solution was 80 ° C. Thereafter, the mesh material 9 is taken out from the degreasing solution, washed with pure water for 1 minute, and then the masking plate 23 and the mesh material 9 having the structure shown in FIG. Grasped in the apparatus. As the masking plate 23, a copper Cu metal plate having a thickness of 0.3 mm provided with 27 openings 24 having an inner diameter φ of 20 mm was used. The slurry used for wet blasting was prepared by dissolving polygonal alumina particles having a particle diameter of 20 μm in water at a concentration of 10 vol%.

In the blasting process, as in Example 1, the mesh material 9 was arranged at the position shown in FIG. 18, and the slurry was jetted downward as the jet flow 42 from the nozzle 41 arranged above the mesh material 9. The vertical distance between the nozzle 41 and the mesh material 9 is 10 mm, and while the slurry is sprayed onto the mesh material 9 at a pressure of 0.3 MPa / cm ² , it starts to move horizontally from the point A, and turns back at the point B. The reciprocating operation for returning to point A was repeated 5 times. The moving speed of the nozzle 41 in this operation was 10 mm / sec.

  Thereafter, the mesh material 9 was taken out from the wet blasting apparatus, washed with pure water for 1 minute, and then the mesh material 9 was subjected to ultrasonic cleaning. The liquid that conducts ultrasonic waves was acetone, the frequency at the time of washing was 35 kHz, and the treatment was performed at 25 ° C. for 5 minutes. Thereafter, the mesh material 9 was taken out from acetone, washed with pure water for 1 minute, and then immersed in an acid active solution for 5 seconds. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material 9 was taken out from the acid-activated liquid and washed with pure water for 1 minute, and then the mesh material 9 was immersed in the plating solution and subjected to an energization treatment for 10 minutes at a current of 5A. Platinum plating S (made by Asahi Yushi Co., Ltd.) was used for the plating solution. Then, it washed with pure water for 1 minute, and manufactured the metal mesh in which the platinum plating film was given to the mesh material 9.

Using the metal mesh produced by the above method as the anode electrode 5, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 were laminated and pressed at 190 ° C. and 50 kgf / cm ² for 5 minutes. At this time, the surface of the anode electrode 5 on which the plating film was applied was made to be a surface in contact with the outside air toward the opposite side of the electrolyte membrane 2. The electrolyte membrane 2 was a DuPont solid polymer electrolyte membrane (Nafion), the cathode catalyst layer 4 was platinum Pt fine powder, and the cathode electrode was carbon paper. Thereafter, carbon powder carrying platinum Pt on the exposed surface of the anode electrode 5 was applied to a thickness of about 30 μm using a coating robot. The dehumidifying element obtained by the above method was punched out using a press machine, and an electrode serving as a contact point with an external DC power source was fixed and attached with a resin casing.

Example 4
A mesh material 9 made of pure titanium Ti having a line width of 100 μm and a thickness of 50 μm and made of fine metal wires having a length of 120 mm and a width of 120 mm is processed by the method described in the second embodiment to manufacture the anode electrode 5. A dehumidifying element was manufactured using this anode electrode 5. An electric furnace was used for the heat treatment in the heat treatment step, and the mesh material 9 made of pure titanium Ti was put in the furnace, heated to 700 ° C., and held for 2 hours. Thereafter, the temperature holding was stopped and the temperature was cooled to 25 ° C., and the atmosphere in the furnace was the same as the atmosphere. Thereafter, the mesh material 9 is taken out from the furnace, washed with pure water for 1 minute, and then degreased composed of 1 wt% sodium orthosilicate, 5 wt% sodium carbonate, 5 wt% sodium hydroxide, 89 wt% pure water. It was immersed in the liquid for 5 minutes. The temperature of the degreasing solution was 80 ° C. Thereafter, the mesh material 9 was taken out from the degreasing solution, washed with pure water for 1 minute, and then subjected to three masking processes using the three masking plates 23a to 23c having the configuration shown in FIG.

  Each of the masking plates 23a to 23c was made of copper Cu and had a thickness of 0.3 mm, and the masking plate and the mesh material 9 were held in a state where the masking plate was stacked on the mesh material 9 in a wet blasting apparatus. The slurry used in the first masking process, that is, the slurry used when using the masking plate 23a of FIG. 17A, was prepared by dissolving polygonal alumina particles having a particle diameter of 20 μm in water at a concentration of 10 vol%. The slurry used in the second and third masking treatment steps, that is, the slurry used when using the masking plates 23b and 23c in FIGS. 17B and 17C, has a particle size of 20 μm. The spherical alumina particles were dissolved in water at a concentration of 3 vol%.

In any of the three masking processes, the vertical distance between the nozzle 41 for injecting the slurry and the mesh material 9 is 10 mm, and the slurry is injected to the mesh material 9 at a pressure of 0.3 MPa / cm ^2. The reciprocating motion which started moving horizontally from the point, turned back at the point B, and returned to the point A was repeated five times. The moving speed of the nozzle 41 in this operation was 10 mm / sec. As shown in FIG. 13, the mesh material 9 having a partially different surface state in the plating region 21 is obtained by the three masking processes.

  Thereafter, the mesh material 9 was taken out from the wet blasting apparatus, washed with pure water for 1 minute, and then the mesh material 9 was subjected to ultrasonic cleaning. The liquid that conducts ultrasonic waves was acetone, the frequency at the time of washing was 35 kHz, and the treatment was performed at 25 ° C. for 5 minutes. Thereafter, the mesh material 9 was taken out from acetone, washed with pure water for 1 minute, and then immersed in an acid active solution for 5 seconds. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material 9 was taken out from the acid-activated liquid and washed with pure water for 1 minute, and then the mesh material 9 was immersed in the plating solution and subjected to an energization treatment for 10 minutes at a current of 5A. Platinum plating S (made by Asahi Yushi Co., Ltd.) was used for the plating solution. Then, it washed with pure water for 1 minute, and manufactured the metal mesh in which the platinum plating film was given to the mesh material 9.

Using the metal mesh produced by the above method as the anode electrode 5, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 were laminated and pressed at 190 ° C. and 50 kgf / cm ² for 5 minutes. At this time, the surface of the anode electrode 5 on which the plating film was applied was made to be a surface in contact with the outside air toward the opposite side of the electrolyte membrane 2. The electrolyte membrane 2 was a DuPont solid polymer electrolyte membrane (Nafion), the cathode catalyst layer 4 was platinum Pt fine powder, and the cathode electrode was carbon paper. Thereafter, carbon powder carrying platinum Pt on the exposed surface of the anode electrode 5 was applied to a thickness of about 30 μm using a coating robot. The dehumidifying element obtained by the above method was punched out using a press machine, and an electrode serving as a contact point with an external DC power source was fixed and attached with a resin casing.

Comparative Example 1
In order to compare the present invention with a conventional example, plating was performed by a general chemical etching process on a titanium Ti mesh material as shown below. In the degreasing step, the mesh material was immersed in the degreasing solution without performing heat treatment on the mesh material, and subjected to an energization treatment at a current density of 5 A / m ² for 1 minute. ELC-400 (manufactured by World Metal Co., Ltd.) was used as the degreasing solution. Thereafter, the mesh material was taken out from the degreasing solution, washed with pure water for 1 minute, and then immersed in the acid active solution for 1 minute. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material was taken out from the acid active solution, washed with pure water for 1 minute, and then immersed in an etching solution for 5 minutes. T-44 (manufactured by World Metal Co., Ltd.) was used as the etching solution. Thereafter, the mesh material was taken out from the etching solution, washed with pure water for 1 minute, and then immersed in the acid active solution for 5 seconds. MC-E (manufactured by World Metal Co., Ltd.) was used as the acid active solution. Thereafter, the mesh material was taken out from the acid active solution, washed with pure water for 1 minute, then immersed in the plating solution, and subjected to a current treatment for 10 minutes at a current of 5 A. Platinum plating S (made by Asahi Yushi Co., Ltd.) was used for the plating solution. Then, it washed with pure water for 1 minute, and manufactured the metal mesh by which the platinum plating film was given to the mesh material.

Using the metal mesh produced by the above method as the anode electrode 5, the cathode electrode 3, the cathode side catalyst layer 4, the electrolyte membrane 2 and the anode electrode 5 were laminated and pressed at 190 ° C. and 50 kgf / cm ² for 5 minutes. At this time, the surface of the anode electrode 5 on which the plating film was applied was made to be a surface in contact with the outside air toward the opposite side of the electrolyte membrane 2. The electrolyte membrane 2 was a DuPont solid polymer electrolyte membrane (Nafion), the cathode catalyst layer 4 was platinum Pt fine powder, and the cathode electrode was carbon paper. Thereafter, carbon powder carrying platinum Pt on the exposed surface of the anode electrode 5 was applied to a thickness of about 30 μm using a coating robot. The dehumidifying element obtained by the above method was punched out using a press machine, and an electrode serving as a contact point with an external DC power source was fixed and attached with a resin casing.

  For the metal mesh produced in Examples 1 to 4 and Comparative Example 1 above, the thickness of the platinum plating film in the plating region was measured. The film thickness was measured at five points in the area covered with the plating film, and the average value was obtained. Here, the value obtained by dividing the average film thickness of the example by the average film thickness of the comparative example is defined as the plating efficiency.

  FIG. 19 is a table showing the average film thickness and plating efficiency in each of Examples 1 to 4 and Comparative Example 1. As can be seen from FIG. 19, in all of Examples 1 to 4, the plating efficiency is higher than 1. This indicates that the amount of platinum Pt required to obtain a film thickness equivalent to that of the conventional method can be reduced. For example, the plating efficiency of Example 1 is 1.85, and the amount of electricity required to obtain a film thickness equivalent to that of Comparative Example 1 when this method is used is 1 / 1.85 = 0.54. This is 0.54 times that of Comparative Example 1. For this reason, for example, by setting the plating time to 0.54 times 324 seconds, the same film thickness as in the conventional method can be obtained, and the amount of metal used can be reduced to 0.54 times.

  DESCRIPTION OF SYMBOLS 1 Dehumidification element, 2 Electrolyte membrane, 3 Cathode electrode, 4 Cathode side catalyst layer, 5 Anode electrode, 6 Anode side catalyst layer, 9 Mesh material, 10 Oxide film, 11 Plating film, 91 1st surface, 92 2nd surface, 21 plating area | region, 22 non-plating area | region, 23 masking board, 23a-23c masking board.

Claims (7)

A heat treatment step for forming an oxide film covering the outer surface of the mesh material by heat-treating the mesh material composed of metal;
After the heat treatment step, a blast treatment step of removing a part of the oxide film from the mesh material by wet blasting or dry blasting; and after the blast treatment step, the oxide film is removed from the outer surface of the mesh material. A method for producing a metal mesh, comprising: a plating step of forming a plating film made of a metal different from the metal constituting the mesh material on the exposed portion. The blast treatment step includes a masking treatment step of jetting a jet flow containing an abrasive to the mesh material through the opening in a state where a masking plate provided with an opening is overlapped on the mesh material. 2. A method for producing a metal mesh according to 1 . The blasting process includes a plurality of the masking processes,
The position of said opening with respect to the mesh material of the masking plate in a state superimposed on the mesh material, the type of the jet injected into the mesh material, according to claim 2 which is different in each of said masking step The manufacturing method of the metal mesh as described in 1 .. After the blasting process, before the plating process, an ultrasonic cleaning process for washing out deposits adhering to the outer surface of the mesh material from the outer surface of the mesh material, and after the ultrasonic cleaning process, before the plating process, metal mesh method according to any one of claims 1 to 3 in which the regeneration oxide film regenerated to the outer surface of the mesh material comprises an acid treatment step of removing from an outer surface of said mesh material. Electrolyte membrane,
A cathode electrode provided on one surface of the electrolyte membrane;
A cathode-side catalyst layer interposed between the electrolyte membrane and the cathode electrode;
An anode electrode provided on the other surface of the electrolyte membrane, and an anode side catalyst layer covering at least a part of the anode electrode,
The anode electrode includes a mesh material made of metal, an oxide film formed by oxidizing the metal constituting the mesh material, and covering the mesh material while avoiding the oxide film. , A metal mesh having a plating film composed of a metal different from the metal constituting the mesh material,
With respect to the thickness direction of the mesh material, the surface of the mesh material visible from one side of the mesh material is the first surface, and the surface of the mesh material visible from the other side of the mesh material is the second surface,
The oxide film covers the first surface and is in contact with the electrolyte membrane,
The plating film is a dehumidifying element that covers the second surface. A cathode electrode, and the cathode-side catalyst layer, an electrolyte membrane, pressing process to obtain a press to laminate in a state of sequentially laminating an anode electrode is metallic mesh, and after the pressing step, the from the electrolyte membrane An anode side catalyst layer forming step of providing an anode side catalyst layer covering at least a part of the exposed surface of the anode electrode on the electrolyte membrane,
The metal mesh is
Mesh material made of metal,
An oxide film formed by coating the mesh material and oxidizing the metal constituting the mesh material;
A plating film made of a metal different from the metal constituting the mesh material, covering the mesh material while avoiding the oxide film;
Have
With respect to the thickness direction of the mesh material, the surface of the mesh material visible from one side of the mesh material is the first surface, and the surface of the mesh material visible from the other side of the mesh material is the second surface,
The oxide film covers the first surface,
The plating film covers the second surface,
In the pressing step, a dehumidifying element manufacturing method for obtaining the laminate in a state where the oxide film is in contact with the electrolyte membrane. A cathode electrode, and the cathode-side catalyst layer, an electrolyte membrane, the pressing step is pressed to obtain a laminate in a state obtained by sequentially stacking the anode electrode from the metallic mesh, and after the pressing step, from the electrolyte membrane An anode side catalyst layer forming step in which an anode side catalyst layer covering at least a part of the exposed surface of the anode electrode is provided on the electrolyte membrane,
The metal mesh is
Mesh material made of metal,
An oxide film formed by coating the mesh material and oxidizing the metal constituting the mesh material;
A plating film made of a metal different from the metal constituting the mesh material, covering the mesh material while avoiding the oxide film;
Have
With respect to the thickness direction of the mesh material, the surface of the mesh material visible from one side of the mesh material is the first surface, and the surface of the mesh material visible from the other side of the mesh material is the second surface,
The second surface is divided into a plating region and a non-plating region,
The oxide film covers the first surface and the non-plated region,
The plating film covers the plating region,
The anode electrode is obtained by punching the metal mesh in the plating region,
In the pressing step, a dehumidifying element manufacturing method for obtaining the laminate in a state where the oxide film is in contact with the electrolyte membrane.

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