JPS5935997B2 - Continuous electroforming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a continuous electroforming device for patterned metal foil or plain foil;
In particular, it relates to a continuous electroforming device for metal foil with low stress.

Conventionally, various types of continuous electroforming apparatus for metal foil have been known, and the obtained metal foil is used for battery meshes, various types of Finovitar, and the like.

The present inventors have previously developed a device (Japanese Patent Application No. 51-80052 and Patent Application No. 51-1982) for forming electroformed foil on a rotatable cathode cylindrical cylinder soil by flowing an electrolytic solution at high speed between narrow poles. 8
(No. 0053) and a high-speed electroforming device (Japanese Patent Application No. 110036/1983) that can maintain a constant narrow distance between electrodes by constantly replenishing the anode that is consumed as the electroforming time progresses.

In this high-speed electroforming device, for example, if the electrolyte is flowed at a flow rate of 2 to 10 m/sec between poles of 1 to 100 ml, the limiting current density will be approximately 200 A/d77-I in the case of nickel plating.
Efficiencies of 80-90% and deposition rates of 25-35 μ/min are obtained, which is about 10 times faster electrodeposition than conventional air stirring methods. However, although the electroformed foil produced using this high-speed electroforming apparatus has a smooth surface and high strength, it has drawbacks such as high stress and low elongation.

Using this device, a matte nickel electrode obtained from an electroforming bath containing 5001/11 nickel flufumate, 109 y/l of nickel chloride, 40 y/l of boric acid, and pH 3.8 can be produced using the high-speed flow method and conventional air stirring method using this device. The physical properties of the cast foil are shown in the table below. The cause of the first surface stress is not fully understood, but in matte or semi-glossy baths, tensile stress occurs, causing the electroformed foil to warp in the opposite direction from the peeling surface from the cylindrical cylinder, causing it to become glossy. Compressive stress is generated in the bath, causing the material to warp toward the peeled surface.

If the degree of curl due to such warpage increases, it is generally not desirable for electroformed products, and especially when used as a battery mesh, even if nickel powder is sintered on it, the sintered powder may crack due to the curl of the foil. This would have caused a major drawback. An object of the present invention is to improve the drawbacks caused by the above-described high-speed electroforming apparatus, and particularly to provide an electroforming apparatus that can continuously produce electroformed foil with extremely low stress at high speed.

The continuous electroforming device of the present invention includes a rotatable cylindrical cylinder that constitutes a cathode, and an arc-shaped anode case that is provided so as to surround the cylindrical cylinder at a constant distance from the circumferential surface of the cylindrical cylinder. The surface of this anode case facing the cylindrical cylinder is ion-permeable, and a supply device for the anode metal ball housed inside is provided at the top; an electrolytic solution is supplied from the electrolytic tank to the gap between the two electrodes. a circulation means for rapid circulation; a means for peeling off the continuous electroformed foil formed on the circumferential surface of the cylindrical cylinder and introducing it into the electrolytic cell; and at least one secondary anode installed in the electrolytic cell. characterized in that the secondary anode is arranged so that the metal is electrodeposited at least on the peeled surface of the continuous electroformed foil introduced into the electrolytic cell, or the metal is electrodeposited thickly on the peeled surface side. do.

This apparatus will be explained in detail with reference to FIG. The cylindrical cylinder 1, which is a cathode, is made of a material from which the electrodeposited electroformed foil can be easily peeled off, for example, the circumferential surface is made of stainless steel or chrome, and rotates in the direction of the arrow.

When manufacturing patterned foil, a pattern of non-conductive parts is formed using a resist. This cylindrical cylinder 1 and about 1 to 20Bn
An arc-shaped anode case 2 is provided to surround the cylinder 1 with a distance between the poles of . This anode case 2
is made of titanium, and the surface facing the cylinder 1 is ion-permeable, for example in the form of a mesh with spacing of about 1 to 10, and is preferably plated with platinum. A cloth for collecting sludge may be attached on top of this net-like surface. Inside the anode case 2 is a metal ball 3 (diameter 5 to 20 mm) made of the metal to be electroformed.
pus) is accommodated and constitutes the anode. When electricity is applied between the two electrodes while flowing the electrolytic solution 4 through the gap between the two electrodes at a flow rate of about 2 to 5 m/sec, the metal balls 3 melt and supply metal ions into the electrolytic solution. As electroforming progresses, the number of metal balls 3 decreases and the anode becomes insufficient in the upper part of the anode case 2. To correct this, a metal ball supply device 5 is provided. This metal ball supply device 5 detects a shortage of metal balls 3 in the upper part of the anode case 2 using an optical sensing device, and replenishes the metal balls 3 by opening and closing a plurality of valves 6, 6'. The electrolytic solution 4 flowing between the two electrodes at high speed is supplied from a separately provided electrolytic cell 7 and circulated by means such as a pump 8 and pipes 9, 9'. In the electrolytic cell T, secondary anodes 10a to 10e are installed which are made of metal balls placed in a flat or mesh metal case. The electroformed foil 12 electrodeposited to a thickness of a fraction of a predetermined thickness, for example τ~ma, is peeled off from the cylindrical cylinder 1 and placed in the electrolytic bath T by means of rolls 11, 11' or the like. Introduce. The remaining thickness is electrodeposited by secondary anodes 10a-10e using conventional air agitation techniques. At this time, the tensile stress or compressive stress can be canceled by electrodepositing the remaining thickness only on the peeled surface of the electroformed foil. That is, as mentioned above, when the electrolytic solution 4 is a matte bath or a semi-glossy bath, tensile stress is generated, and when it is a glossy bath, compressive stress is generated, so if the same electrolytic solution 4 is electrodeposited on the peeled surface. The stress in the newly electrodeposited part acts to cancel out the stress in the previous parts. However, when electrodepositing only on the peeled surface, it takes time to reach the desired thickness, and there is a risk of warping in the opposite direction due to too much stress during electrodeposition in an electrolytic bath. Alternatively, it may be electrodeposited on both sides of the electroformed foil. However, in this case, for example, by adjusting the positions of the rolls 11, 11', etc., the secondary anode 10
It is necessary to make the electrodeposition on the peeling surface thicker than on the other surfaces by placing the electrode a and the peeling surface close to each other and placing the secondary anode 10b away from the electroformed foil 12. FIG. 2 is a diagram illustrating stress compensation of the electroformed foil manufactured in this way.
Stress is indicated by an arrow.

New electrodeposited parts 23 and 23' are electrodeposited thickly on the peeled surface 21 of the electroformed foil 20 produced in the high-speed flow section and thinly on the surface 22, respectively, in an electrolytic bath. The resulting final electroformed foil does not curl as a result of the stress being canceled as shown in the figure. Although five secondary anodes are shown in FIG. 1, there is no control over this number and it is sufficient to have at least one secondary anode.

Regardless of the number of secondary anodes, it is sufficient to arrange the secondary anodes close to the peeling surface of the electroformed foil and away from the other surface. The finally obtained continuous electroformed foil is washed with water in a washing tank 13 and then wound onto a winding roll 14.

According to the electroforming apparatus of the present invention, physical properties such as hardness, elongation, and tensile strength are well balanced because electrodeposition is performed in both the high-speed flow section and the air stirring section, and stress compensation is achieved by electrodeposition in the air stirring section. A continuous electroformed foil with no or very little stress is obtained. As mentioned above, the absence of stress in the obtained electroformed foil is extremely advantageous especially in battery meshes, but it is also desirable for general electroformed products. Furthermore, since the electrodeposited portion in the air stirring section is exposed on the surface, the surface of the electroformed foil tends to be somewhat rough. However, when this is used in a battery mesh, it is even more advantageous because the nickel powder to be sintered becomes easier to adhere to. Furthermore, in this electroforming device, only the desired thickness of 1 to -3 is electrodeposited on the cylindrical cylinder, and the rest is electrodeposited in the electrolytic bath, so that the manufacturing speed of the electroformed foil, that is, the winding of the electroformed foil, is reduced. The speed is 2-3 times faster than when electrodepositing the entire thickness with a cylindrical cylinder.

It goes without saying that this electroforming apparatus can be used to produce not only nickel electroformed foils but also copper and other electroformed foils.

Next, the present invention will be further explained by examples.

Example Using the electroforming apparatus shown in Figure 1, 535 y/l of nickel sulfamate, 8 y/l of nickel bromide, and 37 f of boric acid were used.
A 60μ thick battery mesh was produced using a 1/l matte nickel bath.

The electrodeposition conditions in the high-speed flow section and air stirring section were as shown in Table 2. The manufacturing speed of this electroformed foil (60μ thick) is 1m/2.
5 minutes, which was about three times faster than when this 60 μm electroformed foil was manufactured using only the high-speed flow section. The physical properties of the obtained electroformed foil (battery mesh) are shown in Table 3.

As is clear from Table 3, the battery mesh manufactured by this device has no stress at all, is relatively flexible, and has an appropriate surface roughness, so it has the best adhesion to nickel powder and has ideal quality. It was from.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a specific example of the present continuous electroforming apparatus. FIG. 2 is a cross-sectional view of the electroformed foil for explaining stress compensation of the electroformed foil manufactured by this apparatus, and FIG. 2A is a matte bath,
FIG. 2B shows the case of a gloss bath. 1... Cylindrical cylinder, 2... Anode case, 5... Metal ball supply device, 7... Electrolytic cell, 8... Pump, 10... Secondary anode.

Claims (1)

[Claims] 1. A rotatable cylindrical cylinder constituting a cathode, and an anode case provided to surround the cylindrical cylinder at a constant distance from the circumferential surface of the cylindrical cylinder; A feeding device for an anode metal ball housed in the upper portion, the opposing surfaces of which are permeable to ions; a circulating means for rapidly circulating an electrolyte from the electrolytic cell into the gap between the two electrodes; a means for peeling off the continuous electroformed foil formed on the circumferential surface of the cylinder and introducing it into the electrolytic cell; and at least one secondary anode installed in the electrolytic cell; 1. A continuous electroforming device, characterized in that the device is disposed close to a peeling surface of electroformed foil introduced into an electrolytic bath and away from the other surface.