JPH0625886A - Anode for apparatus for continuous production of metallic foil - Google Patents

Abstract

PURPOSE:To uniformalize the power feed to an insoluble metallic electrode surface and to enable the production of foil having a uniform thickness by mounting ribs at a specific angle on the surface of the insoluble metallic electrode opposite from the surface facing a cylindrical cathode. CONSTITUTION:The ribs are mounted to the surface of the insoluble metallic electrode formed to a curved surface shape opposite from the cylindrical cathode in continuous electrolysis of the metallic foil. The ribs consist of two groups mounted spirally or in other forms on the semicylindrical curved surface of an anode and are so disposed that the ribs belonging to the same group do not intersect and that the ribs of the different groups intersect with each other to enable the uniform power feed to the insoluble metallic electrode surface. The power feed to the anode is executed by mounting conductive members to the ribs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anode used in a continuous metal foil electrolytic production apparatus, and more particularly to an insoluble metal anode having a structure facing a rotating cylindrical cathode.

[0002]

2. Description of the Related Art There are various methods for producing a copper foil, but the main ones are a method of applying pressure by a rolling roller and stretching and a method of producing by electrolysis. The rolling method has a problem that as the thickness of the foil is reduced, the control of the rolling device or the like becomes complicated for adjusting the distance between the rollers, the tensile force of the foil, and the like.

On the other hand, the electrolytic method for producing a copper foil is suitable for the purpose of producing a thin copper foil. This method was developed and put into practical use by American Yates and Shakespeare in the late 1920s and 1930s. In particular, electrolytic copper foil is widely used as a material for a printed circuit board, which is a new wiring method developed together with elements such as transistors.

FIG. 3 shows a copper foil manufacturing apparatus by an electrolytic method. The copper foil manufacturing apparatus 31 is a cylindrical cathode 34 which is rotatable so that half of a curved surface is immersed in an electrolytic solution 33 in an electrolytic bath 32.
Is provided, and a curved anode 35 is provided so as to face the cylindrical cathode. The space between the cylindrical cathode 34 and the anode 35 is supplied with an electrolyte solution from an electrolyte solution slit 36 provided in the anode, and the metal copper 37 deposited on the cathode surface from the electrolyte solution is tangential to the cathode surface. It is a device that produces continuously while peeling. Although the basic configuration of this device has not changed from the original one, it has been widely devised to efficiently manufacture more advanced products.
Product precision and manufacturing speed have made remarkable progress.

Therefore, (1) the cylindrical cathode material for depositing metallic copper from the electrolytic solution is made of titanium or stainless steel from the initial hard lead to improve the accuracy of the cathode surface and to improve the high current density. It was possible to energize. (2) faster flow of the electrolyte in the electrolytic bath, by a uniform operation of what was the current density of 10~20A / dm ^2, at a high current density of 50~100A / dm ² Became possible. (3) The additive was added to the electrolytic solution and the additive was improved. (4) The anode is made of an insoluble lead alloy to improve its durability and to increase the speed by passing a high current density current.

In this way, the basic process has not changed, but compared with the previous one, the current density alone is 3%.
It is up to 6 times or more, and the foil thickness distribution accuracy is greatly improved.

[0007]

The anode made of a lead alloy is easily deformed, and lead or other components of the lead alloy of the anode are slightly eluted into the electrolytic solution, and these eluted substances are contained in the copper foil. Causes impurities. Therefore, in order to solve these problems, instead of the insoluble anode made of lead alloy, D
Manufacture of electrolytic copper foil with insoluble metal anode containing platinum group metal or metal oxide as a main component on a base made of valve metal such as titanium or tantalum provided by the applicant under the trade name of SE or DSA Is being adopted by.

The structure of this insoluble metal electrode is similar to that of a conventional lead alloy electrode, and in order to supply sufficient metal ions for high-speed electrolysis and prevent so-called plating burn, a semi-cylindrical anode facing a cylindrical cathode. A flow path having a uniform interval is formed between the surface and the surface, and the electrolytic solution is caused to flow in a laminar flow. Therefore, the inside of a semi-cylindrical curved surface having a smooth surface formed integrally is used as the anode surface, and power is supplied from the outside of the semi-cylindrical anode.

The size of the anode depends on the size and structure of the electrolytic cell, but there is also a large semi-cylindrical electrode having a plate thickness of 40 mm, a width of 1500 mm and a diameter of 3000 mm, which is a quarter.
Some are divided into arcs. Even in the case of a large-sized electrode, even if a member having a relatively small specific gravity such as titanium is used as the material of the anode, the amount reaches 300 to 500 kg.

The insoluble metal electrode has a longer life than the lead electrode, but since the electrode is deactivated in about several thousand to 20,000 hours, the anode is removed from the metal foil electrolyzer for reactivation. However, it is necessary to regenerate, but reactivating a heavy anode requires a long time for handling and treating the electrode, and the production stop time during regeneration is long, which is a problem in terms of economy. .

In addition, a semi-cylindrical anode is divided into a plurality of members to facilitate the handling. In such a case, in order to apply an electric current evenly to each of the divided parts. , It is not possible to reduce the plate thickness of the plate-shaped electrode,
In addition, complicated conductive connection means are required. Further, if the connecting portions of the plate-shaped electrodes are not completely on the same plane, there is a problem that the current concentrates at the corners and the life of the electrodes is shortened.

[0012]

The present invention relates to an anode for a continuous metal foil electrolytic production apparatus, in which an insoluble metal electrode is formed in a curved surface so as to face a cylindrical cathode, and a cylindrical cathode of the insoluble metal electrode is formed. Ribs are attached to the surface opposite to the surface opposite to. In particular, the ribs consist of two groups attached in a spiral shape to the semi-cylindrical curved surface of the anode. Ribs belonging to the same group are arranged so that the ribs of different groups intersect with each other, and It is possible to uniformly supply power to the electrode surface, and a conductive member is attached to the rib to supply power to the anode.

The insoluble metal electrode used in the present invention is one in which rods or wires are arranged in a comb shape, expanded metal, a mesh of mesh or the like is used as a substrate and the surface is coated with an electrode catalyst substance.

In order to obtain a metal foil at a high speed, the conventional continuous metal foil electrolytic production apparatus is required to flow an electrolytic solution through the cathode cylindrical surface at a high speed so that metal ions are quickly supplied to the cathode surface. For this reason, even if the surface of the anode facing the cathode is not a semi-cylindrical anode having a smooth curved surface without unevenness, unevenness called plating burn is formed, or a uniform thickness distribution cannot be obtained. Was being considered. However, as a result of studies by the present inventors, if the electrode distance between the cylindrical cathode and the anode is 5 mm or more, preferably 7 mm or more, even if irregularities of about 1 to 2 mm are formed on the anode surface, When the flow velocity is 50 cm / sec or more, the electrolytic solution is partially retained on the anode surface, but the flow of the electrolytic solution on the cathode surface is not affected, and such irregularities are uniformly dispersed over the entire anode surface. It has been found that, if present, it does not affect the quality of the obtained metal foil.

Therefore, in the present invention, a metal rod having a diameter of 2 to 4 mm is arranged in a comb shape, or an expanded metal or a woven mesh of thin metal wires is used.
An electrode having a slight unevenness on the electrode surface such as a ven mesh) was used. Since these have irregularities, even if they are divided into several blocks and they are combined, the current concentration due to the steps generated in the combined parts does not occur, and the entire electrode surface has a substantially uniform height. It was possible to have the feature that current concentration does not occur at the same time. Also,
In forming a rib or an insoluble metal electrode, if the accuracy of the base table is improved, a high polar surface accuracy can be easily obtained.

Further, by using such an electrode, in the case of an expanded metal, in the case of a comb-shaped anode of a metal rod having a diameter of 3 mm, which is twice as large as that of a plate-shaped electrode including the area of the back surface. In case of arranging without gap, the area of 1.5 times is obtained, and the distance between the metal bars is 1.5m.
If they are arranged with an interval of about m, they can be used up to the back surface, so that the area is doubled, and the substantial current density can be reduced due to the increase in the electrode area, and the life of the anode is extended. To evenly energize the interdigital electrodes of these expanded metals or metal rods,
It is necessary to attach a conductive rib to the back. The simplest structure of the rib is to form it on the outer surface of the anode in a circumferential direction so that it intersects with a straight line parallel to the rotation axis. Since current concentration occurs in the foil and the thickness of the obtained foil is distributed in the width direction of the foil, it is preferable to displace the foil in both the circumferential direction such as a spiral shape and the rotation axis direction. As a result, the welded portion with the pole face is also arranged with being averaged with respect to the axis of the cylindrical electrode, so that the thickness uniformity in the width direction becomes better. In addition, a conductive member can be attached to these ribs to supply power.

Moreover, in the interdigital electrode or the like in which the metals of the present invention are arranged in contact with each other, the liquid leaks from one surface to the other surface, but the electrolytic solution flows at a high flow rate between the anode and the cathode. Therefore, it has no effect on the state of the electrolytic solution in the electrode interval.

[0018]

The function of the positive electrode for the metal foil continuous electrolytic production apparatus of the present invention is as follows.
The insoluble metal electrode is formed in a curved surface so as to face the cylindrical cathode, and the semi-cylindrical curved surface of the anode has a spiral shape or the like on the surface opposite to the surface of the insoluble metal electrode facing the cylindrical cathode. It has a rib that is displaced from the axis and the direction perpendicular to the axis, and is structurally more complicated than an anode made by processing a flat plate into a curved surface, but a plate-shaped body is processed into a curved surface. It is possible to obtain an anode that can be easily exchanged and regenerated compared to other electrodes, and because an insoluble metal electrode with irregularities is used on the surface, there is no current concentration in the divided parts, and there is a divided structure. It is also easy to

[0019]

The anode of the metal foil electrolytic production apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the anode developed on a plane from the side where the ribs are formed. FIG. 2 is a side view of the anode.

Anode 1 for metal foil electrolytic production apparatus shown in FIG.
The rod-shaped anodes 2 are arranged in a comb-like curved shape and are connected to each other by the ribs 3. A conductive member 4 is attached to the rib so that power can be supplied to the anode through the conductive member.

Example 1 A titanium wire having a diameter of 2 mm and a length of 300 mm was arranged without any interval, and a comb-shaped member was used.
A semi-cylindrical anode for a continuous electrolytic production apparatus for metal foil having a cylindrical cathode having a diameter of 300 mm was produced. Thickness 1.5
Rims made of a titanium plate having a width of 10 mm and a width of 10 mm were knitted in a bent manner by arranging them at intervals of 10 cm so as to form an angle of 45 degrees with the titanium wire. The rib was formed into a curved surface having a diameter of 304 mm, and a comb-shaped titanium wire was attached by spot welding. The titanium wire was arranged in contact with the axial direction of the cylinder.
A conductive member made of a titanium plate having a thickness of 10 mm was mounted on the rib in parallel with the titanium rod.

On the electrode surface, iridium oxide having a thickness of 2 μm was formed by a thermal decomposition method to form an anode.

Using the obtained anode, an aqueous solution containing 150 g / l of sulfuric acid and 100 g / l of anhydrous copper sulfate was added at 50 p / s.
Gelatin was added to give an electrolyte solution of pm. This was electrolyzed at a current density of 100 A / dm ² on the cathode surface while being supplied so that the flow rate on the cathode surface was 50 cm / sec, and the cathode was rotated to obtain a copper foil having a thickness of 20 μm.

After electrolysis for 1 hour, the thickness distribution of the foil in the width direction was measured at 2 cm intervals. The foil is 10 cm
It was cut into pieces, cut into 2 cm intervals and weighed, and the thickness distribution in the width direction of the foil was uniform.

Comparative Example 1 Same thickness as used in Example 1, 1.5 mm, width 10 m
5m of titanium plate should intersect the titanium rod at right angle.
Electrodes were prepared in the same manner as in Example 1 except that the electrodes were provided at cm intervals and were attached to a comb-shaped titanium rod by spot welding, and electrolysis was performed in the same manner as in Example 1 to obtain copper. There was a 10% thickness difference between where the ribs were attached to the foil and between the ribs.

[0026]

INDUSTRIAL APPLICABILITY The anode for the continuous metal foil electrolytic production apparatus of the present invention has a rib attached to the surface of the insoluble metal electrode opposite to the surface facing the cylindrical cathode. It is spirally attached to a semi-cylindrical curved surface, and is attached so as to be knitted in a raised shape, which makes it possible to supply power to the insoluble metal electrode surface evenly, and to affect the attachment to the rib on the electrode surface. Since it can be dispersed evenly, it is possible to manufacture a foil with a uniform thickness even with a structure where welding points are formed on the electrode surface, and by connecting the divided anodes on the ribs, Even if it is divided into a plurality of parts, the current is not concentrated at the divided parts, and an anode capable of producing a foil having a uniform thickness can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram in which a positive electrode for a metal foil electrolytic production apparatus of the present invention is developed on a plane.

FIG. 2 is a side view of an anode for a metal foil electrolytic production apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal foil electrolytic production apparatus, 2 ... Electrolyte tank, 3 ... Electrolyte solution, 4
... Cylindrical cathode, 5 ... Anode, 6 ... Insoluble metal electrode, 7 ... Screw hole, 8 ... Screw, 9 ... Electrolyte supply slit, 21 ... Copper foil manufacturing device, 22 ... Electrolyzer, 23 ... Electrolyte, 24 ... Cylindrical cathode, 25 ... Anode, 26 ... Electrolyte supply slit, 27 ...
Metal copper

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[Procedure amendment]

[Submission date] December 27, 1991

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FIG. 3 is a diagram showing an example of a copper foil manufacturing apparatus by an electrolysis method.

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[Explanation of reference numerals] 1 ... Metal foil electrolytic production apparatus, 2 ... Electrolyte tank, 3 ... Electrolyte solution, 4
... Cylindrical cathode, 5 ... Anode, 6 ... Insoluble metal electrode, 7 ... Screw hole, 8 ... Screw, 9 ... Electrolyte supply slit, 31 ... Copper foil manufacturing device, 32 ... Electrolyzer, 33 ... Electrolyte, 34 ... Cylindrical cathode, 35 ... Anode, 36 ... Electrolyte supply slit, 37 ...
Metal copper

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[Procedure amendment]

[Submission date] December 25, 1992

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[Claims]

Claims (3)

[Claims] 1. An anode for a continuous metal foil manufacturing apparatus, in which a metal foil is electrolytically deposited on the surface of a cylindrical cathode, to form a curved insoluble metal electrode facing the cylindrical cathode,
An anode for a continuous metal foil manufacturing apparatus, characterized in that a rib intersecting a straight line parallel to the rotation axis of the cathode at an angle other than a right angle is provided on the surface of the insoluble metal electrode opposite to the surface facing the cylindrical cathode. . 2. The rib is composed of two groups, and ribs of the same group do not intersect but ribs of different groups, and the ribs are arranged so as to obtain a uniform current distribution over the entire electrode surface. The anode for a continuous metal foil manufacturing apparatus according to claim 2, which is characterized. 3. The electrode according to claim 1, wherein the insoluble metal electrode is a comb-shaped substrate in which rods or linear metals are arranged, an expanded metal, or a net-shaped substrate on which an electrode catalyst coating is formed. Anode for continuous metal foil manufacturing equipment. 3. The anode for a continuous metal foil manufacturing apparatus according to claim 1, wherein the electrode surface can be divided into a plurality of parts.