WO2018016362A1 - Metal electrodeposition cathode plate and production method therefor - Google Patents

Abstract

Provided are a metal electrodeposition cathode plate, the non-conductive film of which is not susceptible to failure and which can be used repeatedly, and a production method therefor. This cathode plate 1 comprises a metal plate 2 on which multiple disc-shaped protrusions 2a are disposed, and a non-conductive film 3 formed on the non-protrusion-2a flat areas 2b of the metal plate 2. The minimum film thickness Y of the non-conductive film 3 at positions between the centers of adjacent protrusions 2a is the same or greater than the height X of the protrusions 2a. It is preferred that the height X of the protrusions 2a is 50 µm to 1000 µm.

Description

Cathode plate for metal electrodeposition and manufacturing method thereof

The present invention relates to a metal electrodeposition cathode plate and a method for producing the same.

Conventionally, electric nickel provided as an anode raw material for nickel plating has been used in a titanium basket serving as an anode holder and suspended in a nickel plating tank. At this time, as the electric nickel as the anode raw material, a plate-like electric nickel electrodeposited on the cathode plate was cut into small pieces.

However, the small pieces of electro nickel were difficult to handle when throwing them into the titanium basket due to the sharp corners. In addition, when the small pieces of electro nickel are put into the titanium basket, the corners get caught in the mesh of the titanium basket and cause so-called shelf hanging, and the filling state in the titanium basket changes, causing uneven plating. There was sometimes.

Therefore, it has been proposed to use small rounded (button-shaped) electric nickel with rounded corners. For example, a small lump of electric nickel is obtained by depositing nickel on the conductive part by electrolysis using a cathode plate in which a plurality of circular conductive parts are arranged at equal intervals, and then electrodepositing from the conductive part. It can be manufactured by stripping off. According to such a method, it is possible to efficiently produce a plurality of small blocks of electro nickel from one cathode plate.

FIG. 5 is a diagram showing an example of a conventional cathode plate used in the production of a small block of nickel. The cathode plate 11 is masked with a non-conductive film 13 on a flat metal plate 12 except for a portion to be a conductive portion 12a. In the cathode plate 11, the conductive portion 12a becomes a concave portion and is non-conductive. The film 13 is a convex portion. By using such a cathode plate 11, nickel having an appropriate size is electrodeposited on the conductive portion 12 a to produce a small lump of electric nickel.

As a method of forming the nonconductive film 13 on the metal plate 12 like the cathode plate 11, for example, as shown in FIG. 6A, thermosetting such as epoxy resin on the flat metal plate 12. There is a method of forming a non-conductive film 13 having a desired pattern by applying a conductive non-conductive resin by a screen printing method and heating (see Patent Documents 1 and 2). FIG. 6B shows a state in which nickel (electric nickel) 14 is electrodeposited on the conductive portion 12a using the cathode plate 11 on which the non-conductive film 13 is formed. In the cathode plate 11, nickel 14 begins to be electrodeposited from the conductive portion 12 a, grows not only in the thickness (longitudinal) direction but also in the plane (lateral) direction, and rises above the non-conductive film 13. Become.

Further, for example, as shown in FIG. 7A, a photosensitive non-conductive resin is applied on the metal plate 22, and the non-conductive resin corresponding to the conductive portion 22a is removed by exposure and development. A method for forming the non-conductive film 23 having a desired pattern has also been proposed. FIG. 7B shows a state in which nickel (electric nickel) 24 is electrodeposited on the conductive portion 22a using the cathode plate 21 on which the non-conductive film 23 is formed. Also in the cathode plate 21, the nickel 24 begins to be electrodeposited from the conductive portion 22a and grows not only in the thickness direction but also in the plane direction.

Further, the cathode plate constituting the non-conductive portion is formed by solidifying the periphery of the metal structure incorporated so that a plurality of studs serving as the conductive portion are arranged at equal intervals with an insulating resin by an injection molding method. A manufacturing method has also been proposed (see Patent Document 3).

Japanese Patent Publication No. 51-036693 Japanese Patent Laid-Open No. 52-152832 Japanese Patent Publication No. 56-029960

Now, when manufacturing a small lump of electronickel using the cathode plate as described above, the non-conductive film (non-conductive part) formed on the cathode plate has a long life, and the non-conductive film is missing (deteriorated). Even in such a case, it is required to be easily maintainable.

As shown in FIG. 6A, when the nonconductive film 13 is formed by applying a nonconductive resin to the metal plate 12 by screen printing, the film thickness of the nonconductive film 13 approaches the conductive portion 12a. Therefore, since it becomes thin gradually, it becomes very thin at the boundary with the conductive part 12a. Such a change in the film thickness of the non-conductive film 13 depends on the coating amount of the non-conductive resin, the viscosity and viscosity temperature characteristics of the non-conductive resin, the curing temperature of the non-conductive resin, the surface roughness of the metal surface and the surface freedom. Depends on energy etc. Therefore, the film thickness of the non-conductive film 13 becomes very thin at the boundary with the conductive part 12a.

As described above, when small-sized electronickel is manufactured using the cathode plate 11 as shown in FIGS. 5 and 6, the nickel 14 begins to be electrodeposited from the conductive portion 12a, and not only in the vertical direction but also in the horizontal direction. Therefore, it gradually rises on the non-conductive film 13 as well. Therefore, in the portion of the thin non-conductive film 13 formed in the vicinity of the boundary with the conductive portion 12a, the adhesion with the metal plate 12 is liable to decrease due to the penetration of the electrolytic solution, and the stress during the electrodeposition of the nickel 14 And it tends to be lost due to the impact when stripping the electric nickel. In addition, once the non-conductive film 13 is lost, the surrounding non-conductive film 13 is lifted from the surface of the metal plate 12, so that the electrolyte is more likely to enter the gap. When trying to deposit, the electrolyte sinks into the gap between the non-conductive film 13 floating from the surface of the metal plate 12, and the nickel 14 is electrodeposited. Then, if the nickel 14 that has entered the gap and is electrodeposited is peeled off, the non-conductive film 13 in which the nickel 14 is biting is further lost.

Thus, in the conventional cathode plate 11, the non-conductive film 13 is lost in a chain, and the nickel 14 grown from the adjacent conductive parts 12 a is easily connected to each other as the missing part expands. The electric nickel having the shape cannot be obtained, resulting in a defective product. Accordingly, before the non-conductive film 13 is lost, it is necessary to remove all the non-conductive film 13 and form the non-conductive film 3 again to prepare the cathode plate 11. However, in practice, it becomes necessary to maintain the cathode plate 11 at a stage where nickel electrodeposition treatment is performed from several times to at most less than 10 times, which not only reduces productivity but also maintenance costs. Increase.

On the other hand, as shown in FIG. 7A, in the cathode plate 21 in which the nonconductive film 23 is formed by exposure and development using a photosensitive nonconductive resin, the nonconductive film 23 is formed with a uniform film thickness. can do. However, when the nickel 24 is peeled off after electrodeposition, the nickel 24 is caught by the step of the non-conductive film 23 constituting the convex portion, and a large impact is easily applied to the non-conductive film 23. Missing will occur.

In addition, in the method of forming the non-conductive portion by injection molding as in Patent Document 3, although the life of the formed non-conductive portion is increased, the manufacturing cost of the cathode plate itself is increased and the non-conductive portion is deteriorated. In this case, maintenance of the cathode plate is difficult.

In view of such conventional circumstances, an object of the present invention is to provide a metal electrodeposition cathode plate that can be used repeatedly, and a method for manufacturing the same, in which a non-conductive film on a metal plate is hardly lost.

The inventors of the present invention have made extensive studies to solve the above-mentioned problem. As a result, it has been found that providing a protrusion on the metal plate to form a conductive portion and providing a non-conductive film on the metal surface other than the protrusion makes it difficult for the non-conductive film to be lost, thereby completing the present invention. .

(1) The first invention of the present invention is a metal plate in which a plurality of disk-like projections are arranged on at least one surface, and a non-conductive film formed on a surface other than the projections of the metal plate And the minimum film thickness of the non-conductive film at a position passing between the centers of adjacent protrusions is equal to or greater than the height of the protrusions.

(2) A second invention of the present invention is the metal electrodeposition cathode plate according to the first invention, wherein the height of the protrusion is 50 μm or more and 1000 μm or less.

(3) According to a third aspect of the present invention, in the first or second aspect, the minimum film thickness of the non-conductive film at a position passing between the centers of the adjacent protrusions and the height of the protrusions A difference is a metal electrodeposition cathode plate which is 200 micrometers or less.

(4) A fourth invention of the present invention is the metal electrodeposition cathode plate according to any one of the first to third inventions, wherein the metal plate is made of titanium or stainless steel.

(5) The fifth invention of the present invention is a metal electrodeposition cathode plate used in the production of electroplating nickel in any of the first to fourth inventions.

(6) A sixth invention of the present invention is a method for manufacturing a metal electrodeposition cathode plate, wherein a first step of forming a plurality of disc-shaped protrusions on at least one surface of the metal plate, and the metal A second step of forming a non-conductive film on the surface other than the protrusions of the plate, and in the second step, the minimum film thickness of the non-conductive film at a position passing between the centers of the adjacent protrusions is This is a method for manufacturing a metal electrodeposition cathode plate that is equal to or higher than the height of the protrusion.

According to the present invention, it is possible to provide a metal electrodeposition cathode plate that can be used repeatedly, and a method for producing the same, that is less likely to lack a non-conductive film.

It is a top view which shows the structure of a cathode plate. It is a principal part expanded sectional view which shows the structure of a cathode plate, (a) is a principal part expanded sectional view explaining the state of the cathode plate before nickel electrodeposition, (b) is the cathode plate after nickel electrodeposition It is a principal part expanded sectional view explaining a state. It is a principal part expanded sectional view which shows the structure of the cathode plate in case the film thickness of a nonelectroconductive film is small, (a) is a principal part expanded sectional view explaining the state of the cathode plate before nickel electrodeposition, (b ) Is an enlarged cross-sectional view of the main part for explaining the state of the cathode plate after nickel electrodeposition. It is a principal part expanded sectional view explaining the manufacturing method of a cathode plate, (a) is a principal part expanded sectional view explaining a 1st process, (b) is a principal part expanded sectional view explaining a 2nd process. is there. It is a top view which shows the structure of the conventional cathode plate. It is a principal part expanded sectional view which shows the structure of the conventional cathode plate, (a) is a principal part expanded sectional view explaining the state of the cathode plate before nickel electrodeposition, (b) is the cathode after nickel electrodeposition. It is a principal part expanded sectional view explaining the state of a board. It is a principal part expanded sectional view which shows the structure of the conventional cathode plate, (a) is a principal part expanded sectional view explaining the state of the cathode plate before nickel electrodeposition, (b) is the cathode after nickel electrodeposition. It is a principal part expanded sectional view explaining the state of a board.

Hereinafter, an embodiment in which the metal electrodeposition cathode plate of the present invention is applied to a metal electrodeposition cathode plate used in the production of electric nickel (hereinafter referred to as “this embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, In the range which does not change the summary of this invention, it can change suitably.

<1. Metal electrodeposition cathode plate>
(1) Configuration of Cathode Plate As shown in FIG. 1, the cathode plate 1 according to the present embodiment includes a metal plate 2 in which a plurality of disc-shaped projections 2a are arranged, and a projection 2a of the metal plate 2. And a non-conductive film 3 formed on the surface other than the above. As will be described later, the cathode plate 1 is used by being hung by a hanging member 5 in an electrolytic cell containing, for example, an electrolytic solution containing nickel or an anode, and nickel having a desired shape is electrodeposited on the surface thereof. Let

[Metal plate]
As shown in FIGS. 1 and 2A, the metal plate 2 is a flat metal plate and has a plurality of disc-shaped protrusions 2a. Here, in the metal plate 2, the surface other than the protruding portion 2a is referred to as a “flat portion 2b” with respect to the protruding portion 2a. Further, “the height X of the protruding portion” is a protruding height from the surface of the flat portion 2 b in the metal plate 2.

In addition, in FIG. 2, although the example which has the projection part 2a on the one surface of the metal plate 2 is shown, you may have the projection part 2a on the both surfaces.

The size of the metal plate 2 is not particularly limited, and may be set as appropriate according to the desired size and number of electric nickel to be manufactured. For example, it can be a rectangular size with one side being 100 mm or more and 2000 mm or less. The thickness of the metal plate 2 is preferably about 1.5 mm or more and 5 mm or less, for example, when the protrusion 2a is provided on one surface, and when the protrusion 2a is provided on both surfaces. Is preferably, for example, about 3 mm or more and 10 mm or less. If the thickness of the metal plate 2 is too small, the protrusions 2a and the flat portions 2b tend to be warped. On the other hand, if the thickness of the metal plate 2 is excessive, the weight of the metal plate 2 increases and handling becomes difficult.

The material of the metal plate 2 is not particularly limited as long as it is a metal that is less corroded by the electrolyte used and forms only loose adhesion with an electrodeposit such as nickel, but titanium and stainless steel are preferred.

In the metal plate 2, the plurality of disk-shaped protrusions 2 a are exposed from a non-conductive film 3 to be described later and function as conductive parts, and the non-conductive film 3 is formed with a predetermined thickness. Accordingly, a concave step is formed by the adjacent protrusion 2a. Hereinafter, the surface exposed from the non-conductive film 3 in the protrusion 2a may be referred to as “conductive part 2c”. In the conductive portion 2c, nickel 4 is electrodeposited by electrolytic treatment.

The size of the disc-shaped protrusion 2a may be set as appropriate according to the desired size of the electric nickel, and the diameter may be, for example, 5 mm or more and 30 mm or less. Further, the height X of the protrusion 2a is preferably 50 μm or more and 1000 μm or less, and more preferably 100 μm or more and 500 μm or less. If the height X of the protrusion 2a is too small, the film thickness of the non-conductive film 3 formed on the flat portion 2b of the metal plate 2 becomes insufficient, and stress during electrodeposition of the nickel 4 and the electric nickel It tends to be lost due to the impact at the time of peeling. On the other hand, if the height X of the protrusion 2a is excessive, for example, when the non-conductive film is formed by screen printing, the number of times of application increases and the productivity decreases. On the other hand, if the height X is excessively large, distortion of the metal plate 2 is likely to occur during the processing of the projecting portion 2a, and the metal plate 2 is likely to warp, making it difficult to form the nonconductive film 3. In addition, in order to reduce the influence by the distortion of the metal plate 2, it is possible to increase the thickness of the metal plate 2, but the weight of the metal plate 2 increases and handling becomes difficult.

Further, fine irregularities may be provided on the surface of the metal plate 2, that is, the surface of the disc-shaped protrusion 2a in the metal plate 2 by sandblasting or etching. Thereby, the nickel 4 electrodeposited on the protrusion 2a can be peeled off with an appropriate impact without dropping off during the electrolytic treatment. In this case, the film thickness of the non-conductive film 3 described later is preferably at least twice the maximum surface roughness Rz of the metal plate 2. If the film thickness of the non-conductive film 3 is smaller than twice the maximum surface roughness Rz of the metal plate 2, there is a concern that pinholes and defective insulation portions of the non-conductive film 3 are generated.

[Non-conductive film]
As shown in FIG. 2, the non-conductive film 3 is formed on a flat portion 2 b that is a surface other than the protruding portion 2 a in the metal plate 2, whereby a plurality of protruding portions 2 a arranged on the metal plate 2 are formed. The surface, that is, the conductive portion 2c is exposed. Then, when nickel 4 is electrodeposited on the conductive portion 2c of the metal plate 2, the nickel 4 is formed by being divided into small blocks.

Here, in the cathode plate 1, the non-conductive film 3 is formed on the flat portion 2 b having a concave step formed by the adjacent protrusion 2 a, so that it is formed with a predetermined thickness. Become. In the cathode plate 1 according to the present embodiment, the non-conductive film 3 has a minimum film thickness Y that is equal to or greater than the height X of the protrusion 2a, and is preferably the same.

The “minimum film thickness Y of the non-conductive film” is defined as the minimum film thickness of the non-conductive film 3 at a position passing between the centers of the adjacent protrusions 2a. As shown in FIG. 2A, the non-conductive film 3 is formed between the adjacent projecting portions 2a so that the central portion rises due to the surface tension. In this case, the minimum film thickness Y of the non-conductive film 3 is the film thickness of the end that comes into contact with the side surface of the protrusion 2a. Moreover, when the film thickness is thick, the non-conductive film 3 may be formed on the surface of the protrusion 2a. The minimum film thickness Y of the non-conductive film 3 at this time is not the film thickness of the non-conductive film 3 formed on the surface of the protrusion 2a, but the film of the non-conductive film 3 formed at a position on the flat portion 2b. The minimum value of the thickness. In the cathode plate 1, although the film thickness varies depending on the position of the projection 2 a to be selected, the minimum value is the minimum film thickness Y.

The non-conductive film 3 is formed on the flat portion 2b having a concave step formed by the adjacent protrusion 2a. For this reason, the non-conductive film 3 is unlikely to have a thin film thickness at the end, unlike the conventional non-conductive film 13 shown in FIG. It becomes difficult to be lost. Further, unlike the conventional non-conductive film 23 shown in FIG. 7, the non-conductive film 3 does not protrude in a convex shape, and its end is protected by a concave step. Therefore, when the nickel 4 is peeled off from the cathode plate 1, the impact of the nickel 4 on the end portion of the non-conductive film 3 is small and the non-conductive film 3 is not easily lost. Thus, since the non-conductive film 3 is not easily lost in the cathode plate 1, it can be used repeatedly for electrodeposition without replacing the non-conductive film 3, reducing maintenance costs and productivity. It is possible to improve.

Furthermore, since the minimum film thickness Y of the non-conductive film 3 is equal to or greater than the height X of the protrusion 2a, the nickel 4 is peeled off from the cathode plate 1 without being caught on the peripheral edge of the protrusion 2a. Can be taken. On the other hand, as shown in FIG. 3, when the minimum film thickness Y of the non-conductive film 3 is less than the height X of the protrusion 2a, when the electrodeposited nickel 4 is peeled off from the cathode plate 1, for example, FIG. The portion indicated by “A” inside is caught on the peripheral edge of the protruding portion 2a and is difficult to peel off.

The upper limit of the minimum film thickness Y of the non-conductive film 3 is not particularly limited, but the difference (Y−X) between the minimum film thickness Y and the height X of the protrusion 2a is preferably 200 μm or less, and preferably 100 μm or less. Is more preferably 50 μm or less, and particularly preferably 5 μm or less. Here, as described above, the minimum film thickness Y of the non-conductive film 3 is not particularly limited as long as it is equal to or greater than the height X of the protrusion 2a, but it is not necessary to make it thicker than necessary. For example, it is difficult to apply the non-conductive film 3 beyond 200 μm from the height X of the protrusion 2a by screen printing. When trying to form the non-conductive film 3 having a film thickness exceeding 200 μm from the height X of the protrusion 2a by screen printing, it is necessary to carry out fine adjustment of the pattern size of the screen plate over a plurality of times. Adjustment is difficult and productivity decreases.

When the non-conductive film 3 is formed on the flat portion 2b on the metal plate 2 by the screen printing method, the material of the non-conductive film 3 is also applied to the surface of the protrusion 2a, and the surface area of the conductive portion 2c is reduced. Although the initial current density may increase, there is no problem if there is no problem in the characteristics of the electrodeposited nickel 4. In addition, the non-conductive film 3 attached on the surface of the protrusion 2a is very thin and is likely to be lost. However, the non-conductive film 3 formed on the flat portion 2b is thick and suppresses the loss. So no problem.

The non-conductive film 3 is not particularly limited as long as the non-conductive film 3 is non-conductive and is made of a material that is less corroded by the electrolyte used. For example, it is preferable to use a thermosetting resin or a photo-curing (ultraviolet-curing resin) resin from the viewpoint of easy film formation. Specific examples include insulating resins such as epoxy resins, phenol resins, polyamide resins, and polyimide resins.

(2) Manufacture of electric nickel using cathode plate In the cathode plate 1 having the above-described configuration, as shown in FIG. 2B, the surface of the protruding portion 2a exposed from the non-conductive film 3 becomes the conductive portion 2c. Then, nickel 4 is electrodeposited. In the cathode plate 1, the nickel 4 grows not only in the thickness direction but also in the planar direction, so that it rises above the non-conductive film 3. Therefore, it is preferable to finish the electrodeposition before the nickels 4 grown from the conductive portions 2c on the surface of the adjacent protrusions 2a come into contact with each other.

Then, after the nickel electrodeposition is completed, the nickel 4 is peeled off from the cathode plate 1, whereby a plurality of small-bulk electric nickel can be obtained from one cathode plate 1. As described above, in the cathode plate 1 according to the present embodiment, since the non-conductive film 3 is not easily lost, the non-conductive film 3 can be used repeatedly without replacement, reducing maintenance costs and producing. It is possible to improve the performance.

In addition, although the cathode plate 1 which concerns on this Embodiment electrodeposited nickel 4, it is not limited to nickel, You may electrodeposit silver, gold | metal | money, zinc, tin, chromium, cobalt, or these alloys. .

<2. Method for producing metal electrodeposition cathode plate>
As shown in FIG. 4, the manufacturing method of the cathode plate 1 according to the present embodiment is a first step of forming a plurality of disc-shaped protrusions 2a on at least one surface of the metal plate 2 (FIG. 4A). ) And a second step (FIG. 4B) for forming the non-conductive film 3 on the surface of the metal plate 2 other than the protrusions 2a.

[First step]
In the first step, a plurality of disc-shaped protrusions 2 a are formed on the surface of the metal plate 2. For example, a portion other than the protrusion 2a is cut away from the flat metal plate 2 to leave the protrusion 2a having the height X, thereby forming the flat portion 2b. The processing method is not particularly limited, and can be performed by, for example, wet etching processing, end mill processing, laser processing, or the like.

For example, when processing a flat stainless steel plate by wet etching, a photosensitive etching resist is applied to the surface of the stainless steel plate, and then exposed through a film or glass on which a desired pattern is drawn and etched. The etching resist is removed by development processing. Then, the developed stainless steel plate is attached to an etching solution (for example, ferric chloride solution), a part of the stainless steel plate from which the etching resist is removed is removed, and finally the etching resist is peeled off to obtain a desired A plurality of disc-shaped protrusions 2a corresponding to the pattern can be formed.

Note that the protrusion 2a may be formed only on one surface of the metal plate 2 or may be formed on both surfaces of the metal plate 2.

[Second step]
In the second step, the non-conductive film 3 is formed on the flat portion 2b that is the surface of the metal plate 2 other than the protruding portion 2a. The method for forming the non-conductive film 3 is not particularly limited, and can be performed by screen printing. In the case where the material of the non-conductive film 3 is a thermosetting resin or a photo-curing resin, heat curing or photo-curing may be performed as necessary.

At this time, the non-conductive film 3 is formed so that the minimum film thickness Y of the non-conductive film 3 at a position passing between the centers of the adjacent protrusions 2a is equal to or greater than the height X of the protrusion 2a. When the desired film thickness cannot be obtained by one screen printing, the above-described screen printing and thermal curing or photocuring may be repeated until the desired film thickness is obtained.

According to the method for manufacturing a cathode plate according to the present embodiment, it is possible to obtain the cathode plate 1 that can be used repeatedly, with the non-conductive film on the metal plate hardly lost by the simple method described above.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. For convenience, members having the same functions as those shown in FIGS. 1 to 6 will be described with the same reference numerals.

<Preparation of cathode plate>
[Example 1]
A cathode plate 1 as shown in FIGS. 1 and 2 was produced. Specifically, first, wet etching was performed on a metal plate 2 made of stainless steel having a size of 200 mm × 100 mm × 4 mm to form disk-shaped protrusions 2a (18 pieces). At this time, the size of the protrusion 2a was 14 mm in diameter and the height was 300 μm, and the minimum distance between the centers of adjacent protrusions 2a was 21 mm.

Next, a non-conductive film 3 was formed by applying a thermosetting epoxy resin on the flat portion 2b of the metal plate 2 by screen printing and curing it by heating at 150 ° C. for 60 minutes. In the cathode plate 1 produced in this way, the difference between the minimum film thickness Y of the non-conductive film 3 and the height X of the protrusion at an arbitrary position passing through the center of the adjacent protrusion 2a is arbitrarily determined by a laser displacement meter. When measured at 10 locations, it was in the range of 40 to 70 μm. Therefore, the minimum film thickness Y of the non-conductive film 3 was 340 μm.

[Example 2]
A cathode plate 1 was produced in the same manner as in Example 1 except that the height X of the protrusion 2a of the metal plate 2 was 500 μm and the nonconductive film 3 was formed with a predetermined thickness on the flat portion 2b. In the cathode plate 1 thus produced, the difference between the minimum film thickness Y of the non-conductive film 3 and the height X of the protruding portion 2a was measured with a laser displacement meter at any 10 points. Therefore, the minimum film thickness Y of the non-conductive film 3 was 510 μm.

[Example 3]
A cathode plate 1 was produced in the same manner as in Example 1 except that the height X of the protruding portion 2a of the metal plate 2 was 60 μm and the nonconductive film 3 was formed with a predetermined thickness on the flat portion 2b. In the cathode plate 1 produced in this manner, the difference between the minimum film thickness Y of the non-conductive film 3 and the height X of the protrusions was measured with an laser displacement meter at any 10 points. Therefore, the minimum film thickness Y of the non-conductive film 3 was 120 μm.

[Example 4]
A cathode plate 1 was produced in the same manner as in Example 1 except that the height X of the protruding portion 2a of the metal plate 2 was 100 μm and the nonconductive film 3 was formed with a predetermined thickness on the flat portion 2b. In the cathode plate 1 thus produced, the difference between the minimum film thickness Y of the non-conductive film 3 and the height X of the protrusions was measured with a laser displacement meter at any 10 points. Therefore, the minimum film thickness Y of the non-conductive film 3 was 200 μm.

[Example 5]
A cathode plate 1 was produced in the same manner as in Example 1 except that the height X of the protruding portion 2a of the metal plate 2 was 40 μm and the nonconductive film 3 was formed with a predetermined thickness on the flat portion 2b. In the cathode plate 1 thus produced, the difference between the minimum film thickness Y of the non-conductive film 3 and the height X of the protruding portion 2a was measured with a laser displacement meter at an arbitrary 10 points. Therefore, the minimum film thickness Y of the non-conductive film 3 was 50 μm.

[Comparative Example 1]
In Comparative Example 1, a conventional cathode plate 11 as shown in FIGS. 5 and 6 was produced. Specifically, a thermosetting epoxy resin is applied by a screen printing method, leaving a conductive portion 12a (18 pieces) having a diameter of 14 mm on a flat metal plate 12 made of stainless steel of 200 mm × 100 mm × 4 mm. Then, it was cured by heating at 150 ° C. for 60 minutes to form the non-conductive film 13, and the cathode plate 11 was produced. In the cathode plate 11 thus produced, the maximum film thickness of the non-conductive film 13 was measured at an arbitrary 10 locations with a laser displacement meter and found to be in the range of 90 to 110 μm.

[Comparative Example 2]
A cathode plate was produced in the same manner as in Example 1 except that the height of the protruding portion of the metal plate was 500 μm and the nonconductive film was formed with a predetermined thickness on the flat portion. In the cathode plate produced in this way, the difference between the minimum film thickness of the non-conductive film and the height of the protrusion was measured with a laser displacement meter at 10 locations, which was in the range of −200 to −150 μm. The minimum film thickness Y of the non-conductive film 3 was 300 μm. The minimum film thickness Y of the non-conductive film 3 is smaller than the height of the protrusions of 500 μm.

[Comparative Example 3]
A metal plate made of stainless steel having a size of 200 mm × 100 mm × 4 mm was subjected to wet etching to form protrusions (18 pieces) having a height of 2000 μm. However, the warpage of the metal plate is large and it is difficult to form a non-conductive film by screen printing.

<Manufacture of electrical nickel>
Using the cathode plate produced in each example and comparative example, electro nickel was produced by electrolytic treatment. Specifically, a cathode plate and an anode plate made of electric nickel of 200 mm × 100 mm × 10 mm were immersed facing each other in an electrolytic cell containing a nickel chloride electrolyte. Then, nickel was electrodeposited on the surface of the cathode plate under the conditions of an initial current density of 710 A / m ² and an electrolysis time of 3 days. After electrolysis, the electronickel deposited on the cathode plate was peeled off to obtain a small lump of electronickel for plating.

<Evaluation>
The number of times that the cathode plate used for the electrolytic treatment can be repeatedly used as it was was evaluated. When the lack of the non-conductive film spreads, the nickel which is electrodeposited at the adjacent protrusions and conductive parts may be connected to each other, so that the desired form of electric nickel may not be obtained. Therefore, when the non-conductive film was missing over 1 mm from the boundary with the protrusion in the flat part direction, the use was stopped and the number of repetitions up to that point was evaluated. Also, when the non-conductive film was missing and the diameter of the conductive part expanded by 1 mm or more, the use was stopped and the number of repetitions up to this point was evaluated.

Table 1 below shows the evaluation results together with the configuration of the cathode plate.

As shown in Table 1, the non-conductive film 3 is formed on the flat portion 2b of the metal plate 2, and the cathode plate 1 in which the minimum film thickness Y of the non-conductive film 3 is equal to or greater than the height X of the protrusion 2a is used. In Examples 1 to 5, the loss of the non-conductive film 3 was suppressed, and it could be used sufficiently repeatedly. In particular, in Examples 1 to 4 in which the height X of the protrusion 2a was 50 μm or more, the number of repeated uses exceeded 10 times.

On the other hand, in Comparative Example 1 in which the non-conductive film 13 was formed in a convex shape on the flat metal plate 12, the non-conductive film was lost and could not be used repeatedly enough. Further, in Comparative Example 2 in which the minimum film thickness Y of the non-conductive film is less than the height X of the protrusion, nickel was caught on the peripheral edge of the protrusion when the nickel was peeled off, and it was difficult to remove.

DESCRIPTION OF SYMBOLS 1 Cathode plate 2 Metal plate 2a Protrusion part 2b Flat part 2c Conductive part 3 Non-conductive film 4 Nickel

Claims (6)

A metal plate in which a plurality of disc-shaped protrusions are arranged on at least one surface;
A non-conductive film formed on the surface other than the protrusions of the metal plate,
The minimum film thickness of the non-conductive film at a position passing between the centers of the adjacent protrusions is equal to or greater than the height of the protrusions.
Cathode plate for metal electrodeposition. The height of the protrusion is not less than 50 μm and not more than 1000 μm.
The cathode plate for metal electrodeposition according to claim 1. The difference between the minimum film thickness of the non-conductive film at the position passing between the centers of the adjacent protrusions and the height of the protrusions is 200 μm or less.
The cathode plate for metal electrodeposition according to claim 1 or 2. The metal plate is made of titanium or stainless steel.
The metal electrodeposition cathode plate according to any one of claims 1 to 3. Used in the production of electro nickel for plating,
The metal electrodeposition cathode plate according to any one of claims 1 to 4. A method for producing a metal electrodeposition cathode plate,
A first step of forming a plurality of disc-shaped protrusions on at least one surface of the metal plate;
A second step of forming a non-conductive film on the surface of the metal plate other than the protrusions,
In the second step, the minimum film thickness of the non-conductive film at a position passing between the centers of the adjacent protrusions is equal to or greater than the height of the protrusions.

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