JPS5835652Y2 - Mother plate for seed plate production - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mother plate for manufacturing a seed plate used as a cathode during electrolytic refining of metal.

In this type of seed plate manufacturing mother plate, the metal that becomes the seed plate is deposited on the surface of the mother plate, which is placed as a cathode in an electrolytic solution, but the seed plate must have a constant shape and the outer periphery must be as straight as possible. Therefore, the metal part of the base plate is exposed by the shape of the seed plate, and the other part, that is, the outer edge of the base plate, is insulated.

Various methods have been proposed for insulating the outer edge of the mother plate, but the mother plate is always immersed in a strong acidic electrolyte solution, and when the seed plate is peeled off from the mother plate, Since mechanical force is applied to the insulating part, the insulating part is severely damaged, and conventional methods have the problem that the life span is only about 3 to 5 months at most.

Conventionally, focusing on the fact that most of the damage to the insulation part occurs at the boundary between the metal surface and the insulation part,
Japanese Utility Model Application Publication No. 53-69407 proposes a method in which a coating layer of cashew paint is applied as the second insulating part.

However, since this conventional second insulating part is formed by applying a coating film, it is troublesome and difficult to finish the inner edge in an accurate straight line, and the inner edge has jagged edges. During electrolytic operation, current concentrates in this area, causing precipitation nuclei called bumps, making it impossible to obtain a high-quality seed plate.

Furthermore, repairing it is troublesome, and if you try to get a complete insulation part without pinholes etc. by painting, the coating will be about 1mm thick, so this painted part will be removed from the surface of the mother board and the outside insulation part. There were some problems in practical use, such as the seed plate had a poor finish, was easily damaged when the seed plate was peeled off, and lacked durability.

The present invention has been developed in view of the above points, and an object of the present invention is to form the second insulating portion by adhesion of an insulating tape made of fluororesin, so that the inner edge of the second insulating portion is To provide a base plate for producing a seed plate having the second insulating part, which is always finished in an accurate straight line, can be easily repaired, has a good finish on the seed plate, and has good durability.

Next, the present invention will be explained with reference to an embodiment shown in the drawings.

FIG. 1 is a front view of the mother plate according to the present invention, FIG. 2 is an enlarged view of the section A in FIG. 1, and FIG. 3 is a B-B line in FIG.
FIG.

In the figure, reference numeral 1 denotes a mother plate, and a plurality of inverted U-shaped mother plate suspension bongs 2 are attached to the upper side of this mother plate 1, and a mother plate support beam 3 is installed inside this mother plate suspension bong 2. is inserted and supported parallel to the upper side of the mother plate 1.

In this embodiment, a copper plate having a side of approximately 1 m and a thickness of approximately 3 to 5 mm is used as the mother plate 1, and both the front and rear surfaces of this plate serve as metal surfaces 4 serving as cathodes. The other part that retains the shape of the seed plate in 4, that is, the mother plate 1
The outer edge of is an insulating part 5.

As shown in FIGS. 2 and 3, this insulating part 5 has a double structure, with the outside of the insulating part 5 serving as a first insulating part 5a that wraps around the edge of the motherboard 1, and the inside being a first insulating part 5a that wraps around the edge of the base plate 1. This first insulating part 5a
A second insulating portion 5b is continuous on the metal surface 4 from the upper surface thereof.

The first insulating portion 5a is formed of a fluororesin layer coated with a fluororesin (for example, polytetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoropropylene resin) using copper sulfide as a binder. The thickness of this fluororesin coating is 100 μm or more (preferably 120 to 170 μm).

This is because if the thickness is less than 100 μm, pinholes will occur in the fluororesin coating, and the fluororesin coating will peel off from the pinholes.

In the present invention, a copolymer of tetrafluoroethylene resin and hexafluoropropylene resin is preferably used.

This is because this resin has a low melting point and can be easily coated thickly.

There are also fewer pinholes.

Further, as the second insulating portion 5b, an insulating tape is used, and this insulating tape is an adhesive tape made of fluororesin and having a thickness of about 25 to 50 μm.

Next, the operation of the mother plate 1 having the above-described configuration will be explained.

First, the mother plate 1 is submerged in the electrolyte 6 so that the metal surface 4 is exposed to the electrolyte 6.
When the base plate 1 is held so as to be positioned below the liquid level 6a and a voltage is applied using the base plate 1 as a cathode, the metal to be refined is deposited on the metal surface 4.

When the thickness of the deposited metal reaches approximately Q, 7 mm, the electricity is turned off and the deposited metal is peeled off from the metal surface 4 of the base plate 1 by applying mechanical force, and this peeling operation is repeated. Then, scratches inevitably occur on the insulating part 5 side at the boundary between the metal surface 4 and the insulating part 5.

If a scratch occurs in this way, simply peel off the insulating tape that is the second insulating part 5b and apply a new insulating tape, and the boundary between the metal surface 4 and the insulating part 5 will remain in its initial state. can be kept.

Further, copper sulfide is used as a base for the fluororesin coating as the first insulating portion 5a;
Since the boundary between the insulating part 5a and the metal surface 4 is covered with the second insulating part 5b, the copper sulfide as the base is covered with the electrolyte 6.
There is no risk of the first insulating portion 5a being coated with the fluororesin coating, and the coating state of the first insulating portion 5a is also ensured.

Furthermore, since the fluororesin coating has a thickness on the order of microns, the level difference at the boundary between the first insulating part 5a and the metal surface 4 is extremely small, and the difference in level between the insulating tape attached to the boundary is extremely small. There is no risk of creating a gap due to a step between the two.
The close contact of the second insulating portion 5b is also ensured.

As explained above, according to the present invention, the second insulating part that is continuous from the upper surface of the first insulating part made of the fluororesin layer on the outer edge of the base plate to the metal surface of the base plate is made of an insulating material made of fluororesin. Since it is formed by adhesive tape, the inner edge of the second insulating section always forms a precise straight line due to the edge of the tape.

Therefore, the releasability of the seed plate is good, and the shape of the seed plate produced is also good.As a result, uniform copper electrodeposition is performed on this seed plate, resulting in the excellent effect of obtaining high-quality electrolytic copper. There is.

In addition, in the case of repair, the repair can be done quickly by simply replacing the tape.

Furthermore, since the above-mentioned tape is made of fluororesin, it has better acid resistance and heat resistance than those made of cashew resin, phenolic resin, or epoxy resin, resulting in a longer service life and better results. is obtained.

In addition, with the tape made of fluororesin used in the present invention, a good second insulating part with a thickness of microns and no pinholes etc. can be obtained, so there is little buildup from the first insulating part, and There is also less damage during peeling, which has the effect of improving both the finish and durability of the seed plate obtained.

[Brief explanation of the drawing]

1 is a front view of a base plate according to the present invention, FIG. 2 is an enlarged view taken along line A in FIG. 1, and FIG. 3 is an enlarged sectional view taken along line BB' in FIG. 1. 1...Mother plate, 4...Metal surface, 5...
...Insulating part, 5a...First insulating part, 5b...
...Second insulation section.

Claims (1)

[Scope of utility model registration request] An insulating part is formed on the outer edge plate of a mother plate for manufacturing a seed plate used for electrical refining of metal, and the outside of the insulating part is a first insulating part made of a fluororesin layer that wraps around the edge of the mother plate, In a mother plate for manufacturing a seed plate, the inside of which is a second insulating portion that continues from the upper surface of the first insulating portion onto the metal surface of the mother plate,
A mother board for producing a seed board, wherein the second insulating part is formed by adhesion of an insulating tape made of fluororesin.