JPS6314068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a matrix necessary for producing electroformed foil, particularly porous foil. Conventionally, when producing porous electroformed foil, various methods have been devised as a matrix, but the following two methods are considered to be representative. This will be explained using figures.

In FIG. 1, recesses 3 are formed in a conductive metal 1 such as stainless steel, iron, or copper by etching or image transfer, leaving a desired pattern 2. The concave portion is filled with a non-conductive resin such as epoxy or polyester, and polished to be flush with the conductive pattern portion 2. The production of this master mold is relatively simple, but the disadvantage is that electroforming spreads laterally, making it impossible to produce thick electroformed foil with a large aperture ratio, and it is difficult to obtain good adhesion of the resin to the etched surface. During electroforming, the liquid penetrates into the part 5, and the resin eventually lifts up and peels off. The durability of the mold before the resin peels off is only a dozen or so times, and even though this mold can be manufactured relatively cheaply, the cost will increase in the end.

FIG. 2 shows a method in which a conductive pattern is provided in a recessed portion in order to obtain a thick electroformed foil with a large aperture ratio using a method that is slightly improved from the master mold shown in FIG. This method uses an aluminum base material, makes it uneven by etching, etc., forms an aluminum oxide film on the protrusions using an anodizing method, making them non-conductive parts, and leaves the concave parts on the aluminum surface as a conductive pattern part. It is. Although this matrix allows the pattern shape to have a wide width as described above, it has the disadvantage that it can withstand only a dozen or so cycles, similar to the matrix shown in FIG. That is, since the aluminum oxide and aluminum are exposed in both the convex portions and the concave portions, there is a problem that they are corroded by the electroforming solution.

In view of these circumstances, the present invention aims at supplying a mother mold with a large number of electroforming lifetimes, and relates to a method for manufacturing such a mother mold. Electroforming master mold 10 of the present invention
The base material 11 shown in FIG. 3 is a flat plate or a cylindrical base material made of aluminum or an alloy thereof. That is, a resin 13 is formed on the anodized convex portions 12 on the surface of this base material 11, and a corrosion-resistant metal 14 is adhered to the aluminum surface in the concave portions, and the desired electroforming material is applied to the conductive portions of the concave portions. It is something that can be formed.

Regarding the manufacturing method of the mother mold of the present invention, FIG.
This will be explained using d. The surface of aluminum or its alloy, which is the base material 11, is coated with a photosensitizer 16 such as polyvinyl alcohol or polyvinyl cinnamate, and a negative film is adhered to the surface, and a high-pressure mercury lamp, carbon arc lamp, etc.
Bake and develop with 3700 Å light for 1 to 5 minutes.
The surface where the underlying aluminum or its alloy is exposed is heated at 0 to 38°C and 0.5 to 3 A/d, for example in a sulfuric acid bath.
A porous anodic oxide film ¹² of 5 to 20 microns is formed on the surface by anodic oxidation under conditions of 5 to 20 microns (FIG. 4a).
In this state, next perform anionic or cationic electrodeposition coating, coat the anodic oxide film with 10 to 30μ of resin 13 such as acrylic, alkyd, or epoxy, and bake at 130 to 170℃ for about 10 to 40 minutes. It is cured under the following conditions (Fig. 4b). Next, the resist film 16 is peeled off, and the exposed aluminum surface is etched with a nitric acid or an alkali such as 5 to 20% caustic soda to a desired depth to form a recess 17 which is a conductive part. (4th
Figure C). Since there is no corrosion resistance as it is, chromium,
By forming a corrosion-resistant metal film 14 such as nickel with a thickness of 1 to 10 μm, the entire aluminum surface is covered (FIG. 4d).

Electroforming is performed using the electroforming master mold thus obtained, and the electroforming material is copper, nickel, iron, zinc, etc. Porous electroformed foil can be used for battery mesh used in alkaline batteries, shadow masks for color televisions, filters, and other decorative applications. The electroforming matrix of the present invention has a non-conductive part in the convex part and a conductive part in the concave part, so it suppresses the lateral spreading (side sprunging) peculiar to electroforming, and it is possible to maintain the shape of the matrix as desired. As a result, a patterned foil with a pattern of Therefore, depending on how the matrix is made, it is possible to produce a thick porous electroformed foil with a large aperture ratio. In addition, by providing a porous base of anodized oxide film on the non-conductive part of the convex part, the adhesion of the resin on it is increased by the projection effect, and the conductive part of the concave part is coated with a corrosion-resistant metal. As a result, corrosion of the matrix caused by the electroforming solution and peeling of the resin have been greatly improved, and it is now possible to have a durability of about 100 to 1000 times, compared to the conventional number of uses of about 10 times. It became.

It goes without saying that the shape of the electroforming matrix according to the present invention may be flat or cylindrical.

Further, the method for forming the resist film is not limited to the above method, and methods such as silk screen printing and offset printing may also be used.

Although the electroforming master mold according to the present invention requires slightly more steps than the conventional method, it is 10 to 100 times more durable than the conventional method.
The advantage is that the total cost is lower.

Example 1 An aluminum cylinder (material: 1100H24) with a circumference of 1.1 m and a width of 500 mm was coated with a water-soluble photosensitive liquid (PVA, ammonium dichromate) using a spray method.
Drying was performed at ℃ for 5 minutes. After this, prepare a polka dot shape (the part that passes the light is circular and 0.1 mm in diameter).
A positive with a pattern of 0.5 mm) was placed in close contact with the film and baked for 2 mm using a high-pressure mercury lamp. (Wavelength 3700 Å) Remove the unexposed area with ammonia hot water to complete development.

Next, a sulfuric acid bath (H ₂ SO ₄ : 15wt%, current density 1A/
dm ² , bath temperature of 20° C., and time of 45 min), an anodic oxide film of 10 μm was formed on the aluminum surface. At this time, the film is Al ₂ O ₃ with pores with a size of 1000 to 2000 Å. After washing thoroughly with water, apply electrodeposition coating.

Electrodeposition coating is an anion type in which the object to be treated is used as an anode, and is mainly made of water-soluble acrylic, with a solid content of 13% and a pH
8.8, a voltage of 100V was applied for 6 minutes to form a 20μ film on the porous Al ₂ O ₃ . After washing with water, 170℃, 30
It was cured under baking conditions of 10 minutes.

After this, the resist film was removed using 10% NaOH (60°C), and etching was performed using a spray method (pressure 1.5 kg/cm ² ) using 10% NaOH (30°C) solution to create a recessed area of 50 μm depth. formed. Immediately thereafter, pretreatment was performed to form a corrosion-resistant metal film. This is a process performed to improve the adhesion between aluminum and corrosion-resistant metal coating, and NaOH525
Zinc was formed on the entire _surface of the aluminum by the substitution method at a temperature of 25° C. and an immersion time of 1 minute.

Furthermore, a sergeant chromium bath (H ₂ SO ₄ : 2.5
g/, CrO ₃ :250 g/, 30 A/dm ² ), and 5μ hard chromium was applied to complete the mold.

Next, nickel electroforming was performed using this mother mold.
The conditions are nickel sulfamate 500 as the bath composition.
g/, nickel chloride 15g/, boric acid 30g/
: Current density 10A/dm ² , bath temperature 50℃, time 25min
We were able to obtain porous electroformed foil with a thickness of 40μ.

It was found that the matrix according to the present invention can withstand 500 uses per part of the matrix, 25 times more durable than the conventional method (Fig. 2), and can significantly reduce the cost of producing porous electroformed foil. was completed.

Example 2 30cm square aluminum alloy (5005Al-Mg system)
A negative pattern (chemical-resistant resist) was formed using silk screen printing. After that, anodization treatment and electrodeposition coating were performed in the same manner as in Example 1, and after dissolving and peeling off the resist with xylene, 10%
Spray method using NaOH (60℃) liquid (pressure 1.0Kg/
cm ² ) to a depth of 100 μm. Thereafter, a corrosion-resistant chromium film was formed on the aluminum surface using the same treatment method as in Example 1, and the mold was completed. Next, copper electroforming was performed using this mother mold. The conditions for copper electroforming are CuSO ₄ 5H ₂ O: 220g/, H ₂ SO ₄ :
60g/, current density 8A/dm ² , bath temperature 40℃, time
It took 55 minutes to form a decorative effective foil of 80μ.

The durability of the matrix of this method is 400 times, compared to the conventional 20 times.
It withstood twice the use.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams of a conventional electroforming mother mold and electroforming foil. FIG. 3 shows the electroforming master mold of the present invention,
An explanatory diagram of electroformed foil obtained by this. FIG. 4 is an explanatory diagram showing a method for manufacturing a master mold for electroforming according to the present invention. 1... Conventional electroforming matrix (1), 2... Metal substrate, 3... Resin, 4... Electroforming foil, 5... Interface between metal and resin, 6... Conventional electroforming Mother mold (2), 7...
Aluminum and alloy thereof, 8... Anodized film (with sealing treatment), 9... Electroforming foil, 10... Mother mold for electroforming of the present invention, 11... Aluminum and alloy substrate thereof, 12... Anode Oxide film (no sealing treatment), 13...electrodeposition coating, 14...corrosion-resistant metal film, 15...electroformed foil, 16...resist film, 1
7... Conductive recess.

Claims (1)

[Claims] 1. On the surface of a flat plate or cylindrical base material made of aluminum or its alloy, a concave part and a convex part that is not etched are formed by etching, and the surface of the convex part is anodized, and then an oxide film is formed. Electrodeposition is performed on the oxide film. A method for producing a mother mold for electroforming, characterized in that a resin layer is provided by painting to make the convex portions non-conductive convex portions, and the concave portions are coated with a corrosion-resistant metal to make the concave portions conductive.