JPH0665794A - Anode - Google Patents

Abstract

PURPOSE:To provide an anode capable of uniformly agitating an electrolyte in a narrow space between both electrodes. CONSTITUTION:An electrical insulating protrusion 1 and/or a recessed hole are formed on the surface of an anode 2 opposed to a cathode. An electrolyte is circulated between the cathode and anode 2 or the anode 2 is moved with respect to the electrolyte, and the electrolyte is uniformly agitated by the protrusion 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anode electrode, and more particularly to an anode electrode capable of exerting a uniform stirring action on an electrolytic solution located between a cathode electrode which is a counter electrode.

[0002]

2. Description of the Related Art When a surface of a large-area flat plate is electrolytically plated with a predetermined metal uniformly, or when various kinds of electrolytic surface treatments are applied to the flat plate, the surface of the same area as a counter electrode is opposed to the flat plate. Smooth flat plate electrodes are closely arranged in parallel, the object to be electrolyzed is connected as a cathode electrode, and the parallel plate electrodes are connected as an anode electrode, and the clearance between both electrodes is filled with a predetermined electrolytic solution to cause an electrolytic reaction. .

For example, in the case of depositing an electrolytic copper foil, a large drum is used as the cathode electrode, and the anode electrode is divided into two axially cylindrical bodies having a diameter slightly larger than that of the large drum and having a smooth inner surface. Using the tank of the shape described above, set the large drum coaxially in this tank, and while rotating the large drum, the copper plating bath is passed through the clearance between the inner surface of the tank and the outer surface of the large drum to carry out the electrolytic reaction. Cause
Copper is continuously electrodeposited on the surface of the large drum.

As described above, an important problem in carrying out an electrolytic reaction by arranging a large-area cathode electrode and an anode electrode in close proximity is to uniformly stir the electrolytic solution flowing through the clearance between the two electrodes so that the cathode electrode Is to uniformly perform the electrodeposition on the surface of. In this case, if the clearance between the electrodes is wide, a mechanism having a stirring action can be arranged there to achieve uniform stirring.

By the way, as the clearance between the electrodes is reduced, the amount of electric power required for the electrolytic reaction can be reduced. Therefore, it is preferable to reduce the clearance between the electrodes economically. However, if the clearance between the electrodes is narrowed, stirring of the electrolytic solution using the stirring mechanism described above becomes practically impossible. For this reason, conventionally, a method of supplying an electrolytic solution from below to the clearance between both electrodes and causing the electrolytic solution to overflow from above, stirring the electrolytic solution itself by the flow of the electrolytic solution, or jetting gas from below the clearance A method of stirring the electrolytic solution in the clearance with the bubbles is adopted.

[0006]

However, in the case of the former stirring method, it is difficult to uniformly flow the electrolytic solution through a narrow clearance, and the initial velocity when the electrolytic solution is supplied from the lower electrolytic solution supply port is Even if it is large, the flow velocity of the electrolytic solution becomes unavoidably small at a place distant from the supply port, and the stirring state of the electrolytic solution becomes non-uniform in the vertical direction. Moreover,
A flow path in which the electrolytic solution easily flows may be formed from the lower side to the upper side of the clearance, which makes it extremely difficult to uniformly stir the electrolytic solution.

In the latter stirring method, the bubbles floating from below the clearance are merged into the large bubbles above the clearance. Therefore, the coalesced bubbles cover the surfaces of both electrodes, and the electrodeposition in those portions is hindered, and the state of the entire finished surface becomes uneven. An object of the present invention is to solve the above-mentioned problems and to provide an anode electrode which itself has an ability of uniformly stirring an electrolytic solution.

[0008]

In order to achieve the above object, in the present invention, an electrically insulating protrusion or / and a recessed hole are provided on the surface facing the cathode electrode which is the object to be treated. An anode electrode is provided which is characterized by being formed. The anode electrode of the present invention has the above-described plurality of protrusions or recessed holes formed on the surface facing the cathode electrode, when the anode electrode is arranged in parallel near the cathode electrode.

Therefore, when the electrolytic solution is caused to flow through the clearance between the two electrodes while the both electrodes are stationary, the flowing electrolytic solution flows while colliding with these projections and recessed holes in a complicated manner, and therefore, there is no clearance. Complete turbulence occurs regardless of vertical or horizontal direction. On the contrary, by moving the anode electrode facing the cathode electrode in the vertical direction and the horizontal direction while the electrolytic solution is stationary, a turbulent flow can be generated in the clearance between the electrodes.

In the anode electrode of the present invention, the protrusion is made of an electrically insulating material. The reason is that if the protrusion is made of a good electric conductor, the distance between the cathode and the cathode electrode in that part will be narrower than in the part where the protrusion is not formed, so the flow of current between the electrodes will be different. This is because it becomes nonuniform, and as a result, the state of electrodeposition on the cathode electrode of the object to be processed also becomes nonuniform.

The protrusions are formed by, for example, screwing a protrusion such as a chip or a plate made of an electrically insulating material such as various plastic materials or ceramic materials on the surface of the anode electrode body having a smooth surface. It can be formed by attachment by mechanical means. These protrusions are
A plurality of electrodes are formed on the surface of the anode electrode body, but if the area occupied by the protrusion facing the cathode electrode becomes excessively large, the current-carrying area of the anode electrode body will become small, and a good electrolytic reaction will not be possible. The area occupied by the protrusions is 10% or less, preferably 5% or less.

The height of the protrusion varies depending on the above-mentioned occupied area, the size of the clearance between both electrodes, the viscosity of the electrolytic solution, etc., but in order to give a uniform stirring effect to the electrolytic solution, Generally, the value is preferably about 30 to 90% of the clearance. Particularly preferably, the value is about 50 to 80% of the clearance. In addition, a plurality of fine recessed holes may be formed on the surface of the anode electrode body without forming the above-mentioned insulating protrusion to form the anode electrode of the present invention. The recessed hole may be a hole that penetrates the electrode.

In this case, if the depth and the hole diameter of these recessed holes are made excessively large, it will be suitable for making the electrolyte solution turbulent, but it will adversely affect the electrolytic reaction and uniform electrodeposition will not be possible. Further, if the recessed holes are too small, turbulence of the electrolyte cannot be sufficiently realized. Therefore, the occupied area of the entire depressed hole is 15 with respect to the total surface area of the anode electrode.
% Or less is preferable. It is particularly preferably 5% or less.

[0014]

Examples of the invention

Example 1 As shown in FIG. 1, a polyethylene chip 1 having a length of 5 mm, a width of 8 mm, a height of 12 mm and a screw 1a protruding from the back surface was prepared. Vertical 1050 mm, horizontal 1050 mm, thickness 5
On one surface of a lead plate 2 having a size of 1,000 mm, 1,000 pieces of the above-mentioned chips 1 were screwed and fixed in a staggered manner at a pitch of 30 mm in both vertical and horizontal directions to form an anode lead electrode as shown in FIG. The occupied area of the chip is 4%.

Further, a low carbon steel plate having a length of 1000 mm, a width of 1000 mm and a thickness of 5 mm was immersed in a 10% sulfuric acid solution at 40 ° C. for 5 minutes and then taken out, followed by washing with water, derusting and degreasing in order to obtain a plated plate. . A chrome plating bath containing 250 g / l of chromic anhydride and 2.5 g / l of sulfuric acid was placed in the plating bath. I arranged them in parallel. The two lead plates arranged in parallel on both sides of this low carbon steel plate were allowed to move up and down in the plating bath while maintaining the condition of parallel arrangement with the low carbon steel plate.

Chromium plating was performed on an iron plate for 40 minutes under electrolytic conditions of a bath temperature of 50 ° C. and a current density of 30 A / dm ² . In this process, the two lead plates were given a reciprocating motion in the vertical direction with an amplitude of 5 cm in the vertical direction and a frequency of 15 times / minute. A chrome plating layer having an average thickness of 14.2 μm was formed on both surfaces of the low carbon steel sheet. The surface gloss of this plating layer was in a satisfactory state, and the variation in the plating thickness of the portion excluding the periphery of 20 mm was 1.01 μm in standard deviation.

For comparison, chromium plating was performed under the same conditions as in Example 1 without reciprocating the lead plate in the vertical direction. The surface gloss of the formed chrome plating layer is in an unsatisfactory state, and the variation in plating thickness is the standard deviation value.
It was 1.48 μm. Example 2 The chips attached to the lead plate used in Example 1 are arranged every other row in the vertical direction of the lead plate, and the through holes 3 having a diameter of 8 mm are arranged between the chip rows. The anode electrode shown in FIG.

Using this anode electrode, chromium plating was performed on a low carbon steel sheet in the same manner as in Example 1. The formed chromium plating layer had an average thickness of 14.9 μm and a standard deviation value of 1.06 μm. In addition, the surface of the plating layer had a very good gloss.

Example 3 The continuous copper foil manufacturing apparatus shown in FIG. 4 was assembled. The titanium plate coated with iridium oxide is bent to a diameter of 152
The semi-cylindrical body 4 with a length of 0 mm and a length of 1200 mm is formed on the inner surface thereof.
A polyethylene plate-like projection 5 having a height of 8 mm, a width of 1.5 mm and a length of 1200 mm is circumferentially arranged to have a length of 30 mm as shown in FIG.
The anode electrode of the present invention was prepared by fixing 53 sheets arranged at intervals of. The area occupied by the plate-like protrusions 5 is 5%.

A drum 6 made of stainless steel having a diameter of 1500 mm and a length of 1200 mm was coaxially set on the anode electrode. At a clearance of 10 mm formed between the inner surface of the anode electrode and the outer peripheral surface of the drum 6, copper sulfate 231 g / l, sulfuric acid 113 from the center of the bottom of the anode electrode.
While supplying a copper plating bath having a bath temperature of 60 ° C and a flow rate of 500 l / min while rotating the drum 6 at a peripheral speed of 16 cm / min as indicated by an arrow, the current density of 17.3 A / dm ² is 10 Copper plating was performed for a minute.

The supplied plating bath overflows from the upper part, but this is supplied again to the clearance for recycling.
Further, the copper foil formed on the outer peripheral surface of the drum 5 was continuously peeled off. In this way, the length is about 10m and the width is about 1000mm.
Of the copper foil was manufactured, the copper foil was cut into a length of 200 mm and a width of 200 mm, and the weight and thickness of the cut pieces were measured.

The average weight was 14.53 g, and the standard deviation value was 1.54 g. The average thickness is 40.1μ
m, and its standard deviation value was 4.3 μm. For comparison,
A copper foil was continuously manufactured in the same manner as in Example 2 without providing a botch on the anode electrode. The average weight of the cut pieces as in the example was 14.48 g, and the standard deviation value thereof was 1.95.
It was g. The average thickness was 40.6 μm, and the standard deviation value was 5.5 μm. Color unevenness was observed on the surface of this copper foil.

Example 4 Instead of the anode electrode of Example 3, width 5 mm, height 8 mm,
As in Example 3, except that the projection electrodes 7 having a length of 8 mm were arranged and fixed in a zigzag manner at intervals of 30 mm in the circumferential direction at intervals of 20 mm as shown in FIG. The copper foil was continuously manufactured.

The resulting copper foil was cut into pieces in the same manner as in Example 2. The average weight is 14.45g, and the standard deviation is 1.
It was 48 g. The average thickness was 40.5 μm and the standard deviation was 4.1 μm.

[0025]

As is clear from the above description, the anode electrode of the present invention has the projections or recesses formed on its surface that can function as a stirrer for the electrolytic solution. Even if the clearance between the body and the cathode electrode is narrow, the electrolytic solution located there can be uniformly stirred, and the surface treatment of the counter electrode can be performed uniformly.

Therefore, the anode electrode of the present invention is very effective when used for treating a large-area cathode electrode.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a chip used for manufacturing an anode electrode of the present invention.

FIG. 2 is a perspective view showing an example of an anode electrode of the present invention.

FIG. 3 is a perspective view showing another example of the anode electrode of the present invention.

FIG. 4 is a schematic view showing an example of a copper foil continuous production apparatus using the anode electrode of the present invention.

5 is a partially cutaway perspective view showing an example of an anode electrode used in the example of the continuous copper foil manufacturing apparatus of FIG.

6 is a partially cutaway perspective view showing another example of the anode electrode used in the example of the continuous copper foil manufacturing apparatus of FIG.

[Explanation of symbols]

 1 chip 1a screw 2 lead plate 3 through hole 4 cylindrical anode electrode 5 plate-like protrusion 6 drum 7 protrusion piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Kato 1-8-8 Kandanishikicho, Chiyoda-ku, Tokyo Furukawa Circuit Foil Co., Ltd.

Claims (3)

[Claims] 1. An anode electrode, characterized in that an electrically insulating protrusion or / and a recessed hole are formed on the surface facing the cathode electrode. 2. The anode electrode according to claim 1, wherein the protrusions and / or the recessed holes are arranged in a staggered pattern. 3. The anode electrode according to claim 1, wherein the protrusions are arranged in a weir shape as plate-like protrusions.