JPS6223445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in an apparatus for manufacturing electrolytic foil for electrolytic capacitors.

[Technical background of the invention and its problems]

To perform etching on aluminum foil, the aluminum foil and a carbon electrode are immersed in a hydrochloric acid solution, and a direct current is applied using the aluminum foil as an anode and the carbon electrode as a cathode. In this case, chlorine ions generated by electrolysis of hydrochloric acid corrode the surface of the aluminum foil, resulting in etching. Also, at this time, aluminum ions are dissolved and diffused into the solution. On the other hand, hydrogen ions generated at the same time as chlorine ions gather on the carbon electrode and become hydrogen gas.

If a similar situation occurs in a continuous etching device, the hydrochloric acid and aluminum in the etching solution will
The weight decreases or increases in proportion to the amount of electricity flowing between the two poles, respectively.

Therefore, in order to keep the hydrochloric acid concentration and aluminum concentration of the solution constant during etching, sufficient water to dilute the increased aluminum to the desired aluminum concentration and hydrochloric acid capable of compensating for the decreased hydrochloric acid are supplied. It is necessary.

In DC etching, it is well known that the lower the aluminum concentration in the etching solution, the higher the etching expansion rate. ,
Replenishment of hydrochloric acid is required.

[Purpose of the invention]

The present invention was made based on the above-mentioned circumstances, and consists of bringing the aluminum concentration in the etching solution as close to zero as possible, and reducing the amount of acid supplied to only the amount of electricity.
The object of the present invention is to obtain an apparatus for manufacturing electrolytic foil for an electrolytic capacitor that can perform etching with a large etching expansion rate.

[Summary of the invention]

The apparatus for manufacturing electrolytic foil for electrolytic capacitors of the present invention runs an aluminum foil facing a carbon electrode in an etching solution, applies direct current to the aluminum foil with the aluminum foil as a positive electrode and the carbon electrode as a negative electrode, and etches the aluminum foil. The method is characterized in that a cation-permeable diaphragm is disposed between the aluminum foil carbon electrodes.

[Embodiments of the invention]

Figure 3 shows the raw material of the present invention. Between the aluminum foil 1 which is the anode and the carbon electrode 2 which is the cathode,
A special diaphragm 3 is interposed. This diaphragm has the property of allowing cations such as hydrogen ions and aluminum ions to pass therethrough, but not allowing anions such as chloride ions to pass therethrough. When each electrode and diaphragm 3 described above are immersed in a hydrochloric acid solution and a direct current is applied, aluminum ions exit from the aluminum foil 1 and pass through the diaphragm 3, heading toward the carbon electrode, and aluminum ions generated by electrode decomposition pass through the diaphragm 3. However, the hydrogen directed toward the carbon electrode is not diffused into the etching solution A between the diaphragm 3 and the aluminum foil 1 by convection. Thus, the etching solution B between the diaphragm 3 and the carbon electrode 2 has a high aluminum concentration. Although the amount of hydrochloric acid in the etching solution A decreases according to the amount of electricity, since the aluminum concentration is maintained at a low level as described above, it is only necessary to replenish the amount of hydrochloric acid corresponding to the amount of electricity.

FIG. 1 shows an embodiment of the present invention constructed according to the principle described above. A carbon electrode support plate 12 having a plurality of slits 11 through which aluminum foil passes is provided in the casing 10 of the etching device.
A carbon electrode 13 is supported on the support plate 12 with a slit 11 in between. Guide rollers 14 and 15 are provided below the support plate 12 and above the carbon electrode 13, respectively. Aluminum foil 1
6 travels through a folded path that is folded back by guide rollers 15 and 16, and each guide roller
The upper and lower running portions of the aluminum foil are provided at positions formed between adjacent carbon electrodes. Further, the aluminum foil 16 passes through the slit 11 and runs. Further, a diaphragm 17 similar to the diaphragm 3 is provided between the upper and lower running portions of the aluminum foil 16 and the carbon electrode.

Although only one part is shown as arrow 18 in the figure, the etching liquid with a high aluminum concentration between the diaphragm 17 and the carbon electrode 13 (etching liquid B in Fig. 3) is appropriately discharged through the discharge pipe. Ru. In addition, since the etching solution leaking from the gap between the aluminum foil and the slit 11 is an etching solution with an aluminum concentration close to zero (etching solution A in Fig. 3), the etching solution dropped and stored at the bottom of the casing is removed. It is collected with a collection tube 19 shown in the figure and used again for etching.

As described above, according to the present invention, the aluminum concentration of the etching solution that directly etches the aluminum foil can be kept extremely low, so that the etching expansion rate can be improved. In addition, the etching solution with a high aluminum concentration is discharged, but the electrolytic solution with a low aluminum concentration only needs to be replenished with hydrochloric acid according to the amount of electricity, and the etching solution leaking from the slit is collected and used. Because you can
The cost of aluminum foil can be reduced.

In the case of the configuration shown in FIG. 3, the movement of aluminum ions in chamber A with respect to the diaphragm 3 is slower than the movement of hydrogen ions, so the aluminum ions in chamber A are moved quickly. In order to keep the amount as low as possible, it is necessary to forcefully and quickly move the liquid in chamber A.

FIG. 4 shows the principle of another embodiment of the present invention constructed with the above points in mind. A first diaphragm 3 that allows only cations to pass through to the carbon electrode 2 side, and a second diaphragm 4 that allows only anions to pass to the aluminum foil 1 side are provided between the aluminum foil 1 and the carbon electrode 2. . An etching solution is forced to flow through the space A between the second diaphragm 4 and the aluminum foil 1, and this etching solution is sent into the space B between the first and second diaphragms 3 and 4.

By doing as described above, the aluminum ion concentration of the etching solution in the space A is kept low, and the chlorine ions supplied from the etching solution in the space B through the diaphragm 4 perform etching with a large enlargement ratio. Aluminum ions are trivalent, and hydrogen ions are monovalent. Since monovalent ions more easily permeate the cornea 3, the concentration of aluminum ions in the etching solution in space B increases gradually. When the aluminum ion concentration reaches a certain value, the aluminum ions pass through the diaphragm 3 and enter the space C between the diaphragm 3 and the carbon electrode 2. The etching solution in space C is discharged when the aluminum ion concentration becomes high.

FIG. 2 is a schematic diagram of a second embodiment based on the raw materials described above. In the figure, the same parts as in FIG. 1 are given the same reference numerals, and 20 indicates the second diaphragm. The etching solution in the space A, which is forced to flow through, flows through the slit 11 and is stored at the bottom of the casing 10. This is supplied to the lower part of the space B via the pipe line 21 by a pump.

This embodiment also provides the same effects as the first embodiment.

〔Effect of the invention〕

According to the present invention, an electrolytic foil etched with a large etching expansion rate can be manufactured by replenishing an amount of acid equivalent to the amount of electricity, so a high-quality electrolytic foil can be supplied at a low cost. .

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a first embodiment of the present invention;
FIG. 2 is a similar diagram of the second embodiment, and FIG. 3 is a similar diagram of the first embodiment.
FIG. 4 is a similar diagram of the second embodiment. 13...Carbon electrode, 16...Aluminum foil, 1
7...first diaphragm, 20...second diaphragm.

Claims (1)

[Claims] 1. In etching the aluminum foil by running the aluminum foil opposite the carbon electrode in the etching solution and applying direct current with the aluminum foil as the positive electrode and the carbon electrode as the negative electrode, cations are generated between the aluminum foil and carbon electrodes. An apparatus for producing electrolytic foil for electrolytic capacitors, characterized by having a permeable diaphragm arranged therein.