JPS6021394Y2 - aluminum plate - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an aluminum plate, and particularly to an aluminum plate having a beautiful iridescent coating.

Conventionally, aluminum plates with colored coatings on their surfaces include those with colored alumite coatings formed by electrolysis;
Alternatively, those coated with resin such as paint or lacquer are known.

However, the film formed by conventional electrolytic methods has the disadvantage of being a single color and lacks beauty, and the film formed by coating resin has poor mechanical, chemical, and thermal durability. It had the disadvantage of being scarce.

By the way, conventionally, a colored alumite film is produced by a first electrolytic process in which an alumite film is formed on the surface of an aluminum plate, and a second electrolytic process in which an aluminum plate having an alumite film obtained from the first electrolytic process is colored. Aluminum plates with are manufactured.

Here, the first electrolytic step was carried out under various conditions. The electrolyte was soluble in aluminum, and the anode current was ((+) side current total)/
When an alternating current with a ((-) side current total amount) of 1/1 or more was used, a constant iridescent alumite film could be formed regardless of the type of metal used in the second electrolytic step.

The present invention was devised in view of the above circumstances, and its purpose is to provide an aluminum plate having a robust and beautiful iridescent coating.

In the present invention, the anode current in an electrolyte that is soluble in aluminum is (total current on the (+) side) / ((-
) In the pores of the porous alumite film formed by anodizing while melting with an alternating current with a side current of 1/1 or more,
It is characterized by forming an iridescent alumite film by depositing a metal or a metal compound.

The present invention will be described in detail below with reference to FIG. 1, which shows an example of the present invention.

In FIG. 1, an aluminum plate 1 is separated from an aluminum base 2 and an alumite film 3 having a metal or metal compound colloid formed on the surface of the base.

A method for forming such an alumite film on the surface of an aluminum plate includes the following two electrolytic steps.

That is, in the first electrolytic step, an aluminum plate or an alumite plate that has been polished, smoothed, and brightened is used as an anode, and ( (+) side current total)
/ ((-) side current total amount) That is, in FIG. 2 showing an example of the change in anode current over time, the ratio Q4/Q5 of the total area Q4 of the positive current region 4 and the total area Q5 of the negative current region 4 is 1. A porous alumite film is formed on the surface of the aluminum plate by electrolyzing using alternating current of /1 or more, preferably 2/1 to 10/1.

Sulfuric acid is not used as an electrolyte because it has no solubility in aluminum.

By using such an electrolytic solution and electrolytic conditions, the aluminum plate can be anodized in the same way as before, and at the same time, electrolytic polishing can be performed due to the inclusion of a moderate negative current in the anode current and the solubility of the electrolytic solution. This process forms a porous alumite film that has larger pore diameters than before and is glossier.

In the second electrolysis step, Ni, Sn, CoXCu
In an electrolytic solution containing ions such as ions, electrolysis is carried out using alternating current or direct current, using the aluminum plate having the porous alumite film obtained in the first step as a cathode, and the metal is deposited in the pores.

In the alumite film formed in the first electrolysis process, a second
During the electrolytic process, colloids of metals or metal compounds are precipitated.

This special electrolytic method produces a so-called iridescent color, which is mainly a mixture of red and green, which is different from conventional electrolytic methods, but this is due to the optical interference effect of the precipitated colloidal particles. It is based on

Therefore, unlike various resin films, it does not fade or change color even when exposed to ultraviolet rays or heated.

Furthermore, since the base material of the film is alumite, it has excellent mechanical, chemical, and thermal durability, such as being resistant to scratches, not being attacked by acids or alkalis, and not deteriorating even when exposed to ultraviolet rays or heated. It has its advantages.

Moreover, since it is formed by electrolysis, it can be easily mass-produced and is inexpensive.

In order to form this iridescent alumite film only on specific parts of the aluminum plate, it is sufficient to mask the other parts so that they do not participate in the electrolytic reaction.

Furthermore, since changing the electrolysis time in the first or second electrolysis step will cause a difference in the color tone of the alumite film, it is necessary to set a difference in the electrolytic treatment time between a specific part of the iridescent alumite film and other parts. This makes it possible to add patterns to the iridescent alumite film itself.

Furthermore, as shown in FIG. 3, a unique aluminum plate can be manufactured by coating the alumite film 3 of the aluminum plate according to the present invention with a transparent or translucent thin coating 6.

That is, by covering with the coating film 6, the interference and scattering conditions of the coloring surface can be changed, and the hue can be easily changed.

As the material for forming such a coating, synthetic coating agents such as lacquer, and natural coating agents such as lacquer can be used.

Furthermore, a synthetic resin film may be thermally welded.

If the aluminum plate according to the present invention is used to produce household items such as tableware and kitchenware, as well as crafts, those having a robust and beautiful iridescent alumite film can be obtained.

As described above, the aluminum plate according to the present invention has a beautiful iridescent alumite film that is strong and does not easily discolor or fade, can be mass-produced, and is inexpensive.

[Brief explanation of the drawing]

FIGS. 1 and 3 are cross-sectional views of an aluminum plate according to an example of the present invention, and FIG. 2 is a diagram showing an example of the waveform of an anode current in the first electrolytic process for producing an aluminum plate according to the present invention. . 1... Aluminum plate, 2... Aluminum base, 3... Alumite film, 4...
...Positive current region, 5...Negative current region, 6...
...paint film.

Claims (2)

[Scope of utility model registration request] (1) Anodic oxidation is carried out while dissolving aluminum in an electrolytic solution that has a solubility for aluminum, using an alternating current with an anodic current ratio of (total current on the (+) side)/(total current on the (=) side) of 1/1 or more. An aluminum plate characterized in that a metal or a metal compound is precipitated into the pores of the porous alumite film formed by the process, thereby forming an iridescent alumite film on at least a portion of the surface of which the hue appears different depending on the direction. (2) The aluminum plate according to claim 1, wherein at least a part of the surface of the iridescent alumite film is coated with a transparent or translucent coating film.