JPH0217638B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is applicable to continuous electrolytic treatment on the surface of metal materials such as metal plates and metal strips while supplying an electrolytic solution into an electrolytic treatment tank. More specifically, regarding the insoluble electrode device used, for example, electroplating on the surface of a metal strip, cathodic surface treatment such as electrolytic chromate,
This is an insoluble electrode device used when continuously applying anodic surface treatment such as anodizing, and it is an insoluble electrode device that is constantly kept fresh throughout the interelectrode space formed between the metal strip to be treated and the insoluble electrode device that is the counter electrode. It is possible to supply the electrolytic solution, and also to control the flow of the electrolytic solution flowing through the space between the electrodes, reducing the unevenness of the liquid flow, and as a result, the metal strip to be processed has a high-quality surface. The present invention relates to an insoluble electrode device with a novel structure that can be processed.

(Prior art) When performing a surface treatment such as electroplating on a metal strip, the metal strip is meandered in an electrolytic solution, and an anode is placed opposite the part of the metal strip that is immersed in the electrolytic solution. Then, electrolytic treatment is performed using the metal strip as a cathode.

One example will be explained based on the schematic diagram shown in FIG. In FIG. 5, 1 is a processing tank filled with a predetermined electrolytic solution 2. Reference numeral 3 denotes a metal strip to be subjected to surface treatment, which is fed into the electrolytic solution from outside the tank and travels through the solution in the direction of arrow P or the opposite direction thereof. 3a and 3b are guide rollers. Reference numeral 4 denotes an anode, which is placed opposite to the part of the metal strip immersed in the electrolytic solution at a predetermined distance.

Various shapes and materials have been proposed for the anode, such as a mesh plate made of an insoluble metal such as titanium, niobium, or tantalum, a perforated plate, or a plain plate with an active material such as platinum or iridium oxide on the surface. Examples include insoluble electrodes coated with substances. One row is shown in a perspective view in FIG. In the figure, 4a represents a net surface composed of the above-mentioned insoluble metal and active substance. Also,
FIG. 7 is a side view of another example in which a frame 4b is provided around the mesh electrode plate to maintain the shape of the mesh electrode plate as shown in FIG. .

During such electrolytic treatment, efforts are made to continuously supply the electrolytic solution to the processing tank and to continuously discharge it from the processing tank so that the metal strip to be processed is always in contact with fresh electrolytic solution. It is being said. For example, an electrolyte supply section (not shown) is provided at the bottom of the space between the electrodes, and the electrolyte is supplied from there, and a drainage section (also not shown) is provided at the top of the treatment tank to drain the liquid. Various methods have been adopted, such as a method in which an electrolyte supply section is provided in the upper part of the processing tank and a drainage section is provided in the lower part of the processing tank to drain the liquid. In any case, the purpose of these measures is to constantly supply fresh electrolyte in a regular flow state with little unevenness over the entire range of the interelectrode space.

(Problem to be Solved by the Invention) By the way, when continuous electrolytic treatment is performed using the apparatus shown in FIG. 5, the electrolyte is supplied from the bottom, drained from the top, Supplied from
The electrolyte is supplied to the space between the electrodes by various methods such as draining from the bottom, but since the anode 4 is just a single flat plate or a mesh-like electrode plate, the electrolyte existing in the space between the electrodes is in a stopped state or in a natural state. Either the convection state, the nomadic flow state caused by the above-mentioned supply-drain system, or the involuntary nomadic flow state or the turbulent flow state.

For example, even if electrolyte is supplied from the bottom of the interelectrode section and drained from the top, if the amount of fresh electrolyte supplied is small or the pressure at the time of supply is low, the electrolyte will The liquid may not reach the upper drainage area in a uniform and fresh state.

Therefore, the metal strip 3 undergoing surface treatment
It cannot be said that the entire surface to be treated is in contact with a fresh electrolyte of the same quality, and therefore the surface treatment of the metal strip is progressing in a homogeneous state on all treated surfaces. It's hard to say.

The present invention solves the above-mentioned problems, and makes it possible to form a fresh and uniform flow of electrolyte in the interelectrode space formed between the entire treated surface of the metal strip and the anode. The purpose of the present invention is to provide an insoluble electrode device with a novel structure that enables high-quality surface treatment.

(Means for Solving the Problems) In order to achieve the above object, the present inventor has conducted extensive research and has come up with a structure in which the anode itself can attract the electrolyte in the inter-electrode space, and has achieved this effect. After confirming this, we have developed an electrode device having the structure of the present invention.

That is, in the insoluble electrode device of the present invention, an electrolytic solution flow regulating plate and a porous electrode plate are arranged in this order on the opening surface of a box-like body that is open on one side and provided with an electrolyte outflow hole on the other side. It is characterized by being worn.

The electrode device of the present invention will be explained in more detail based on the exploded perspective view illustrated in FIG.

In the figure, 11 is a box-shaped body made of a liquid-impermeable material, and one side of the box is open.
Form 1a. Reference numeral 12 denotes at least one electrolyte outflow hole bored in the box-like body 11, and the hole may be formed in any surface other than the opening surface 11a. The figure shows 1 on the lower surface of the box-like body 11.
Shows the condition with holes drilled. And this outflow hole 12
As shown in the figure, an electrolyte outflow pipe 12a is attached.

Reference numeral 13 denotes a porous electrode plate, which, in addition to the mesh electrode plate illustrated in FIG. 6, may be a porous sheet electrode plate in which a large number of through holes of a predetermined shape are distributed within the plate surface, for example. In short, any plate-shaped electrode body may be used as long as the electrolyte can pass from one surface to the opposite surface.

14 is a liquid flow adjustment plate, and the opening surface 11 of the box-shaped body
a and the porous electrode plate 13.

This liquid flow regulating plate has a plurality of holes formed from one end of the plate surface to the other end. It is a plate body that is formed so that it becomes larger toward the sides. The porosity referred to here refers to the pores formed in the divided parts when the inside of the liquid flow control plate is equally divided from one end to the other end. It is defined as the product of the number and the area of the hole.

FIG. 1 illustrates a case where the hole is a slit groove 14a. The slit grooves 14a are distributed in a sparse manner with a distance between them in the lower plane of the drawing, and are distributed in a dense manner with narrower intervals in the upper plane. Furthermore, the slit grooves in the lower surface can be made narrower and the slits in the upper surface wider. Therefore, the porosity is large in the upper part of the figure and small in the lower part.

Figure 2 shows a circular hole 14 whose holes are distributed within the plate surface.
In case b, for example, small-diameter holes are sparsely distributed in the lower part of the figure, and large-diameter holes are densely distributed in the upper part of the figure. Note that the hole is not limited to a circular hole, and may have any shape, such as a circular hole or various square holes.

Further, the liquid flow regulating plate shown in FIG. 3 has a structure in which a plurality of shutter blades 14d are horizontally suspended between the box-like opening surface 11a and the side frames of a frame body 14c having the same shape. . In this case, the space 14e formed between the shutter blades 14d becomes a hole. In this structure, the inclination angle of the shutter blade 14d is adjusted; for example, the inclination angle of the shutter blade located in the lower part of the figure is made larger, and the inclination angle of the shutter blade located in the upper part of the figure is made smaller. For example, the aperture ratio of the hole can be set higher toward the top of the figure.

In these liquid flow control plates, the shape, size, distribution, porosity, etc. of the holes formed on the plate surface are determined by various conditions in the surface treatment of the material to be treated.
For example, it needs to be changed depending on the dimensions and shape of the material to be treated, electrolytic conditions, liquid permeability of the porous electrode plate, etc., and cannot be determined unambiguously. More subtly, depending on the attachment position of the electrolyte outflow pipe 12a, fine adjustment can be made by changing the size of the hole and its arrangement, for example, on the left and right sides of the plate surface. In short, the size and distribution of the holes in the liquid flow control plate can be changed so that the electrolyte flows uniformly through the space between the electrodes.

The electrode device of the present invention is used in the following manner. The state is illustrated in FIG. 4 as a schematic diagram.
In the figure, 1 is a processing tank, 2 is an electrolytic solution filled therein, and 3 is a metal strip running in the direction of arrow P or the opposite direction.

The electrode device of the present invention illustrated in FIG. 1 is arranged so that the running metal strip 3 and the porous electrode plate 13 face each other with a predetermined distance therebetween. In the case of the figure, box-shaped body 1
The liquid flow regulating plate interposed between the porous electrode plate 1 and the porous electrode plate 13 is mounted so that the end side where the porosity is small is located downward. Then, fresh electrolyte is supplied from the lower point A of the space between the electrodes, and the box-like body 1
An electrolytic solution outflow pipe 12a attached to the lower surface of the electrolytic solution outflow pipe 12a is connected to a suction device such as a drainage pump to discharge the electrolytic solution from there.

In this state, the liquid permeability of the porous electrode plate is approximately the same within its surface, and the liquid flow control plate located behind it has a large porosity above it and a small porosity below it. In the upper part of the interelectrode space, the electrolyte is in a state where it easily flows, and in the lower part, it is in a state where it is difficult to flow. Therefore, the electrolytic solution supplied from the supply port A does not flow into the box-shaped body so much in the lower part of the device, but flows directly into the upper part, and shifts to a state where it flows more easily. Due to this, the supply port A and the electrolyte outflow pipe 12a are located close to each other, and if there were no liquid flow adjustment plate, the supplied electrolyte would take a shortcut and would not reach the upper part. The problem is resolved. That is, because the supply port A and the electrolyte outflow pipe 12a are close to each other, the electrolyte tends to easily pass through a short path between them, and due to the action of the liquid flow adjustment plate, the electrolyte tends to pass upward. Since these two tendencies cancel each other out, it is possible to secure a sufficient amount of liquid that flows into the box-shaped body after the electrolyte reaches the upper part. Therefore, a sufficient amount of fresh electrolyte can flow into the interelectrode space from the supply port A at the bottom to the farthest hole.

Although FIG. 4 shows the case where the supply port A is provided at the bottom, the supply port A may be provided at the top. At this time, install a liquid flow control plate on the device, contrary to the case shown in the figure.
That is, it may be attached to the box-shaped body so that the side with the smaller porosity faces upward.

In the electrode device of the present invention, the manner in which the liquid flow adjustment plate is attached differs depending on the positional relationship between the electrolyte supply port and the drain port, but usually the liquid flow is directed to the electrolyte supply port side. Attach the adjustment plate so that the side with the smaller pore area is facing.

(Effects of the Invention) As is clear from the above explanation, the electrode device of the present invention allows a liquid flow of electrolyte with little unevenness to any part of the interelectrode space by the action of the liquid flow regulating plate described above. It can be made fresh at all times. Therefore, since fresh electrolyte is supplied to any part of the metal strip running in the tank, the metal strip can be subjected to a higher quality surface treatment than before.

In addition, the electrolytic gas generated on the surface of the porous electrode plate of the device of the present invention is efficiently sucked and removed into the box-shaped body at any point on the plate surface, so that these gases do not drift into the space between the electrodes. This eliminates the possibility of non-uniform current distribution due to partial heat generation of the liquid or the like, or of quality deterioration of the treated surface caused by these gases reaching the treated material.

Although the device of the present invention has been described in connection with continuous electroplating on a metal strip running in a tank, the electrode device of the present invention can be used not only in this case but also in treatments such as electrolytic chromate and anodic oxidation. Moreover, even when electroplating a flat metal plate, using the device of the present invention can prevent the thickness of the plating layer from varying depending on the location and the quality of the plating layer deteriorating. This is useful because it can eliminate inconveniences.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one example of the insoluble electrode device of the present invention. FIGS. 2 and 3 show other examples of liquid flow regulating plates to be attached to the insoluble electrode device of the present invention, respectively. FIG. 4 is a schematic diagram showing how the insoluble electrode device of the present invention is used. FIG. 5 is a schematic diagram showing how a conventional electrode is used, FIG. 6 is a schematic diagram showing one example of the electrode, and FIG. 7 is a side view of another example. 1... Processing tank, 2... Electrolyte, 3... Metal strip,
4... Reticular electrode plate, 11... Box-shaped body, 12... Electrolyte outflow hole, 12a... Electrolyte outflow pipe, 13...
Porous electrode plate, 14...liquid flow adjustment plate, 14a, 14
b, 14c... Hole.

Claims (1)

[Claims] 1. A box-shaped body having an opening on one side and an electrolyte outflow hole on the other side, and an electrolyte flow adjustment plate and a porous electrode plate attached in this order to the opening surface of the box-like body. An insoluble electrode device characterized by: 2. A plurality of holes through which liquid can pass are formed in the liquid flow regulating plate from one end of the plate surface to the other end, and the aperture ratio of the holes is equal to that of the one end. The insoluble electrode device according to claim 1, wherein the insoluble electrode device becomes larger from the end toward the other end. 3. The insoluble electrode device according to claim 1 or 2, wherein the liquid flow regulating plate has a slit hole bored in the lateral direction of the plate surface. 4. The insoluble electrode device according to claim 1 or 2, wherein the liquid flow regulating plate has at least one hole selected from the group of circular holes, circular holes, and square holes. 5. The insoluble electrode device according to claim 1 or 2, wherein the liquid flow control plate has a shutter structure.