JPH06306668A - Method and device for regenerating manganate to permanganate - Google Patents

Abstract

PURPOSE:To efficiently perform electrolytic regeneration of manganate to permanganate by electrically oxidizing and to make handling extremely easy and simple. CONSTITUTION:The regenerating quantity is extremely increased by oppositely providing a cathode 1 coated with a non-conductor and a honeycomb shaped, cylindrical or rectangular shaped anode 2 as one pair so as to be (1:10)-(1:1000) in area ratio of cathode to anode, connecting each anode 2 in parallel, getting the distance between the cathode 1 and the anode 2 closely near as much as possible to apply current at a low voltage and electrolytic treating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electrolytically regenerating manganate to permanganate and an apparatus therefor, and more specifically, it relates to an electric regeneration of manganate generated in an alkaline permanganate solution. Oxidization into permanganate to regenerate it into permanganate.

[0002]

2. Description of the Related Art Generally, a corrosive solution used in a processing step for manufacturing a printed circuit board is an alkaline bath containing permanganate as an oxidant, and therefore, when corrosive operation is performed, permanganate is converted into manganese. It is known that the precipitate of acid salt accumulates as a decomposition by-product, which lowers the ability of the corrosive liquid. In particular, in the production of a multilayer wiring circuit board as a printed circuit board, the molten resin (smear) is generated by the frictional heat caused by drilling. It adheres to the inner layer circuit cross section in the hole and causes a connection failure. Therefore, in order to remove this smear, smear is removed using an alkaline permanganate solution, but by treating the printed circuit board, permanganate is changed to manganate, and further reaction If you proceed, it will become manganese dioxide sludge. Therefore, several methods have been found to regenerate permanganate at the manganate stage so as not to generate this manganese dioxide sludge. As a method thereof, a method using a regenerant (U.S. Pat. No. 4,592,852) is provided with a single cylinder electrode type electrolytic regenerator (as shown in FIG. 6, a perforated cylinder pair a is provided with a cathode rod b at the center and an anode rod c around the same. Partition electrode type electrolytic regenerator (Japanese Patent Laid-Open No. 1-294882)
Are known.

[0003]

However, in the conventional method using the regenerant, the generation of sludge is recognized at the same time,
In addition, the electrolytic regeneration efficiency with respect to current is as low as 10 to 15% in the single-tube electrode type electrolytic regenerator, and the regeneration efficiency is improved in the partition electrode type electrolytic regenerator, but the solution to be regenerated on the anode side and the alkali on the cathode side are regenerated. It was difficult to handle such that the metal hydroxide solution was gradually mixed with the aqueous solution, and the regeneration efficiency was poor, which was a problem. SUMMARY OF THE INVENTION The present invention is intended to easily eliminate these conventional drawbacks, significantly improves the electrolytic regeneration efficiency from manganate to permanganate, and is also extremely easy to handle and its apparatus. It is intended to provide.

[0004]

According to the present invention, a part of the cathode is coated with a non-conductive material during electrolytic treatment by applying it to a cathode and an anode immersed in an alkaline permanganate solution. And the area ratio of cathode to anode is 1:10 to 1: 1000.
In addition, the method is a regeneration method from manganate to permanganate, which is characterized in that electrolytic regeneration is performed by connecting electrolytic regeneration electrodes in parallel with each other and passing an electric current. Further, in the apparatus of the present invention, in the electrolytic regenerator in which a plurality of electrodes consisting of a cathode and an anode are provided in a tank main body into which the alkaline permanganate solution is introduced in a state of being immersed in a plurality of solutions, a part of the cathode is not provided. Cover with a conductor and make the area ratio of cathode to anode 1:
The anodes are arranged in a honeycomb or tubular shape in the vicinity of a rod-shaped cathode close to each other so as to have a ratio of 10 to 1: 1000, and the anodes are connected and arranged in parallel, and the tank body is desmeared in a circulation path having a liquid circulation pump. A manganate to permanganate regenerator characterized by being connected to a tank.

[0005]

In an alkaline permanganate solution, a solution containing manganate generated by electro-oxidation is placed in a tank having a cathode and an anode, and both electrodes are immersed and a current is passed. That is, in the case of a single-cylinder electrolytic regenerator, hydrogen generated near the cathode causes a reaction of converting permanganate to manganate, so that a part of the cathode is covered with a non-conductive pair to prevent generation of hydrogen. In order to increase the amount of regeneration (manganese salt to permanganate salt), the anodes were connected in parallel, and at the same time, the cathode also became a pair with the anode, and the area ratio of cathode to anode was 1:10 to 1: 1000. As a result, the permanganate can be increased and the current can be reduced to 1 at a low voltage by reducing the distance between the cathode and the anode.
It is possible to easily flow up to 00A, and handling can be significantly simplified.

[0006]

EXAMPLE An example of the present invention will be described with reference to the examples of FIGS. 1 to 5. A tank body 3 used in a regeneration method has a cathode 1 partially covered with a non-conductive material, and a honeycomb shape or a cylindrical shape or a square shape. The pair of cylindrical anodes 2 are provided as a pair, and the area ratio of the cathodes to the anodes is set to 1:10 to 1: 1000, and the pair is arranged in pairs.
In addition to connecting the anodes 2 in parallel, the cathode 1 and the anode 2 are made as close as possible to each other, and the tank body 3 is placed in a desmear treatment tank 4 containing an alkaline permanganate solution 5 and a liquid circulation pump 6 is provided. A certain route 7 and a return route 8 are connected by piping. (Fig. 1)

[0007] The cathode 1 is a rod-shaped electrode made of a conductive material such as copper, over a portion which is coated with a non-conductive to 1 _1, such as Teflon, for example below 850mm of copper rod in 3φ full length 1000 mm, Teflon A plurality of products obtained by intermittently repeating a coated part 43 mm and a non-coated part 7 mm penetrates through the fitting holes 14 of the plastic support plate 10 such as Teflon, and is connected and supported by the copper-connecting plate 21. A honeycomb-shaped anode 2 is welded to a connecting rod 20 having a threaded portion in the vicinity of the cathode 1, and a tip portion thereof penetrates a fitting hole 15 of the support plate 10 and is fixed by a nut 19. (FIGS. 2 and 3) This anode 2
Is made up of a large number of honeycomb-shaped or cylindrical-shaped aggregates, and it is considered that the cathode 1 is arranged at the center of each cylinder, but the anode 2 is a perforated plate having a large number of punching holes as necessary. A cylindrical shape may be used.

The connection rod 20 and the-connection plate 21 are connected to each terminal of a- + connection cable connected to the rectifier 9, so that the support plate 10 can properly maintain the electrodes of the cathode 1 and the anode 2. The support plate 10
Is integrated with the upper lid body 30. (FIG. 4) Then, although this electrode is provided in the tank body 3 and has an out-tank type, it may be provided directly in the desmear treatment tank 4 and the tank body 3 may be omitted to have an in-tank type.

As shown in FIG. 5, the support plate 10 is provided with fitting holes 14 and 15 for connecting and inserting the connecting rods 20 of the rod-shaped cathode 1 and the anode 2, respectively, and the rod-shaped cathode penetrating from the support plate 10. Although the connecting cable is connected to 1 and the connecting rod 20, it may be connected to the end of each rod through a terminal piece. The connecting plate 21 has a rod-shaped cathode 1
There is incorporated in the support plate 10 have been secured by a nut 1 _2.

Reference numeral 19 in the figure is used for fixing the connecting rod 20 with a mounting nut. 25 is a sludge discharge valve, 26,
Reference numerals 27 and 28 are control valves, and 29 is an electrode cover, which is provided on the support plate 10 as required. Reference numeral 30 denotes an upper lid body, and the support plate 10 and the connection plate 21 are bolted to the support tank body 3.

In the embodiment, the manganate generated in the alkaline permanganate solution is used. However, in order to electrically oxidize the generated manganate and regenerate it into permanganate, the electrode is used. It is taken into consideration that the material of the electrode should be easy for electricity to pass through, and the structure of the electrode is to make the anode 2 into a honeycomb-shaped rectangular tube or cylindrical shape, connect them in parallel, and pass the cathode 1 in the middle of each anode 2. In this way, by bringing the cathode 1 and the anode 2 closer to each other, the current is reduced to 10 at a low voltage.
It became possible to flow up to 0A.

In this case, in the example of FIG.
As a result of continuing electrolytic regeneration at 00A for 32.5 hours, the results were as follows. As a result of analyzing the solution in the tank, potassium permanganate was 44.71 g / l, potassium manganate was 5.52 g / l, and as compared with the initial stage, 9288 g of permanganate was obtained.
(Ie 25.24 g / l) while manganate decreased by 8721 g (ie 23.70 g / l).

[0013]

[Table 1]

Further, at the manganate concentrations shown in Table 2, the electrolytic regeneration efficiency with respect to the electric current was as shown in Table 2.
Therefore, when the concentration of manganate is up to 15 g / l, it is about 50
% Electrolytic regeneration efficiency is obtained. Further, since the equilibrium point of the manganate concentration by electrolytic regeneration is suppressed to a low concentration of 5 g / l, manganese dioxide sludge generated by further reaction from the manganate can also be suppressed.

[0015]

[Table 2]

[0016]

According to the present invention, a part of the cathode is covered with a non-conductive material so that the area ratio of the cathode to the anode is 1:10 to 1: 1000, and the electrolytic regeneration electrodes are connected in parallel. By electrolytically regenerating by passing an electric current, the electrolytic regeneration efficiency against the electric current is good, and it is easy to handle, the sludge of manganese dioxide is reduced, the treatment with satisfactory performance can be performed, and the desmear treatment is continuously performed. Since the treatment can be facilitated, the productivity can be greatly improved, and the regeneration method and the regeneration device can be provided at a low cost and which is very advantageous.

[Brief description of drawings]

FIG. 1 is a system explanatory diagram of an embodiment of the present invention.

FIG. 2 is a plan view of electrodes of a reproducing device used in the example of FIG.

3 is a cutaway side view of a portion of the example of FIG.

FIG. 4 is a perspective view of the cathode part of the example of FIG. 2 in a separated state.

5 is a perspective view of the anode part of the example of FIG. 2 in a separated state.

FIG. 6 is a partially cutaway perspective view of a conventional single-tube electrode type electrolytic regenerator.

[Explanation of symbols]

 1 Cathode 2 Anode 3 Tank body 4 Deamis treatment tank 5 Alkaline permanganate solution 6 Liquid circulation pump 7 Route 8 Return route 9 Rectifier 10 Support plate 20 Connecting rod 21-Connecting plate 30 Upper lid

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05K 3/26 7511-4E

Claims (2)

[Claims] 1. When applying electrolytic treatment by applying to a cathode and an anode immersed in an alkaline permanganate solution,
A part of the cathode is covered with a non-conductive material so that the area ratio of the cathode to the anode is close to and opposite to each other with the area ratio of the cathode to the anode being 1:10 to 1: 1000, and the electrolytic regeneration electrodes are connected in parallel to flow an electric current for electrolytic regeneration. A method for regenerating manganate to permanganate characterized by: 2. In an electrolytic regenerator in which a plurality of electrodes composed of a cathode and an anode are placed in a tank body into which an alkaline permanganate solution is introduced so as to be immersed in a plurality of solutions, a part of the cathode is made of a non-conductive material. And the anodes are arranged in close proximity to each other around the rod-shaped cathode in a honeycomb shape or in a cylindrical shape so that the area ratio of the cathode to the anode is 1:10 to 1: 1000, and the anodes are connected and arranged in parallel. A manganate to permanganate regenerator characterized in that the tank body is connected to a desmear treatment tank through a circulation path having a circulation pump.