JPS6141276B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method for producing a pattern on the surface of aluminum.

In this specification, aluminum is a general term for aluminum and aluminum alloys.

Conventionally, various methods have been proposed to create patterns on the surface of aluminum, which has a complex cross-sectional shape and is used for various purposes such as building materials and furniture, by immersing the aluminum before anodizing in a certain liquid and treating it with electricity. has been done.

In such a method, hydrogen gas generated on the surface of aluminum by current treatment forms an upward locus on the surface of the aluminum, and this locus forms a pattern. However, the generation of hydrogen gas during the energization process is not always constant and is extremely irregular, making it impossible to produce a consistent and regular pattern on the surface of aluminum, and also making it impossible to reproduce the same pattern. It has some inconveniences.

In addition, since the patterns produced by this method depend exclusively on the upward trajectory of hydrogen gas, only monotonous line patterns or straight-grained patterns can be obtained, making it difficult to create patterns suitable for the exterior design of aluminum for various uses. It has disadvantages that cannot be obtained.

On the other hand, if you are trying to generate a free design pattern, there is nothing better than a general printing method, but it has a problem that it cannot be applied to aluminum, which has a complicated cross-sectional shape.

Therefore, the present invention provides a patterned surface treatment method that can generate not only monotonous line patterns but also free design patterns similar to printing methods, even on aluminum for building materials having a complicated cross-sectional shape. With this purpose in mind, this product is unique and ingenious, and uses ultraviolet-curable resin paint that is applied to the aluminum surface to create a pattern.

The method of the present invention will be described in detail below.

First, it is necessary to form an anodic oxide film on the aluminum to which the ultraviolet curable resin paint is applied. This process involves pre-treatments such as degreasing, washing, etching, and smut removal using conventional methods, followed by direct current electrolysis in a bath for producing a porous oxide film using sulfuric acid, oxalic acid, sulfuric acid/oxalic acid mixed acid, etc. , AC electrolysis, AC/DC superimposed electrolysis, or other electrolytic treatment using a current waveform having an equivalent effect.

Although a normal anodic oxide film does not develop color, it may be colored during formation of this anodic oxide film.

Further, the present invention can be applied to a material that has been subjected to the following treatments after the anodic oxide film is formed.

(1) Aluminum colored by electrolytically treating an anodic oxide film in a coloring bath containing the acid or salt of a metal involved in coloring, such as nickel, cobalt, manganese, copper, tin, or iron.

(2) The aluminum that has formed the anodic oxide film is treated with orthophosphoric acid, pyrophosphoric acid, phosphorous acid, chromic acid, sulfuric acid, sulfuric acid with a high concentration of 40V/V% or more,
or a bath mainly containing one or more inorganic acids among these salts, malic acid, maleic acid, citric acid, sulfosalicylic acid, gallic acid, etc.
The OH group can be prepared by immersing it in a bath mainly containing one or more of various organic acids containing -COOH groups, or their salts, or a mixture of these baths, and then applying an electric current to the solution. Aluminum colored in a color tone different from that obtained by method (1) by changing the micropore structure of the anodic oxide film and then electrolytically coloring it by the method (1) above.

A pattern-like pattern is formed using UV-curable resin paint on the anodic oxide film of aluminum treated in this way. The main ingredient is a photopolymerizable prepolymer such as mold or polyether type, and it also consists of a photopolymerization initiator that absorbs ultraviolet light and starts the polymerization reaction, a photopolymerizable monomer as a diluent, and various additives such as pigments. It is something.

The pattern is formed as follows.

That is, the above-mentioned ultraviolet curable resin paint is applied to the entire surface of one side of a thin film made of an appropriate water-soluble material such as polyvinyl alcohol using a roll coater, and then this coated surface is irradiated with ultraviolet rays. At this time, as shown in FIG. 1, an ultraviolet shield 3 is interposed between the ultraviolet source 1 and the thin film 2. This ultraviolet shielding body 3 has ultraviolet transmitting portions 4 at appropriate positions, which together with ultraviolet absorbing portions 5 form an appropriate pattern.

Therefore, the ultraviolet rays are transmitted through only the transparent portions 4 and irradiated, and the ultraviolet curable resin coating 6 is cured in places corresponding to the transparent portions 4.

In addition to the above-mentioned polyvinyl alcohol, thin film materials include synthetic polymers such as sodium polyacrylate, polyvinylpyrrolidone, polyethylene oxide, methyl cellulose, carboxymethyl cellulose, and acrylic acid amide. Examples of animal polymers include glue, Examples of such polymers include gelatin, casein, and polypeptides, and examples of vegetable polymers include starch, cellulose, dextrin, and soybean protein.

The use of hydraulic pressure is effective in adhering the ultraviolet curable resin paint, which has a cured portion and an uncured portion, to the anodic oxide film as described above.

The use of hydraulic pressure means, as shown in Figure 3, that after the thin film 2 with the coated side of the ultraviolet curable resin paint facing up is floated on the liquid surface, the aluminum 7 is submerged in the liquid while pressing the coated surface. By doing so, the thin film 2 is brought into close contact with the entire surface of the aluminum 7 using hydraulic pressure, and the ultraviolet curable resin paint 6 on the coated surface is adhered to the surface of the aluminum. This method works particularly effectively when the aluminum 7 has a complicated cross-sectional shape.

In this adhesion step, the cured resin paint 6a does not blend with the surface of the aluminum 7, so it does not become adhered, and only the uncured portion 6b adheres to the surface of the aluminum 7.

Then, when the aluminum 7 is immersed in, for example, hot water while the thin film 2 remains in close contact with the thin film 2, the hardened resin paint 6a is removed as the thin film 2 is dissolved.
As shown in FIG. 4, only the uncured resin paint 6b remains on the surface of the aluminum 7, forming a pattern.

Therefore, if aluminum is not colored, if a pigment is added to the ultraviolet curable resin coating, a colored pattern with the color tone of the pigment can be obtained.

Further, when aluminum is colored or colored, if a pigment different from the color tone is added to the ultraviolet curable resin coating, a colored pattern based on the difference in color tone can be obtained.

After this, if the uncured patterned UV-curable resin paint adhered to the aluminum surface is irradiated with ultraviolet rays, the UV-curable resin paint will harden while penetrating into the micropores, causing the aluminum surface to harden. The coating adheres even more tightly to form a patterned coating layer.

As described above, the present invention uses ultraviolet curable resin paint to create a colored pattern, and since ultraviolet rays are used to pattern the resin paint that adheres to the surface of aluminum, Unlike the case where a pattern is formed by means such as printing, the pattern can be formed in an extremely short time using simple equipment, and is effective in improving the efficiency of surface treatment work.

Examples of the present invention will be shown below.

Example 1 Aluminum was degreased and cleaned in a 10 Wt% nitric acid bath, etched by immersing it in a 5 Wt% sodium hydroxide bath at a bath temperature of 50°C for 8 minutes, and then smut removed by immersing it in 10 Wt% nitric acid. alloy
A6063S in 15Wt% sulfuric acid bath at 20℃, electric density 1.0A/dm ²
Anodizing was performed for 30 minutes.

On the other hand, 20% of orange UV-curable resin paint (Daikiyu UV Ink SSK type, manufactured by Dainippon Ink Co., Ltd.) was applied to one side of the polyvinyl alcohol thin film.
The coating is applied to a thickness of μm, and the coated surface is irradiated with ultraviolet rays for 1 second using a high-pressure mercury lamp (output 2KW) through an ultraviolet shielding body that has a floral-patterned ultraviolet absorbing area to partially cure the ultraviolet curable resin paint. I let it happen.

Such a thin film was floated on a liquid surface, and a sufficiently dried aluminum alloy was pressed onto the coated surface and submerged in the liquid, so that the thin film was brought into close contact with the surface of the aluminum alloy using liquid pressure.

Next, the thin film was removed with warm water at 40°C, and the cured UV-curable resin was removed, leaving an uncured floral-patterned UV-curable resin paint on the surface of the uncolored aluminum alloy, resulting in an orange color. A colored floral pattern was generated.

Example 2 An aluminum plate A1200P that had been pretreated and anodized in the same manner as in Example 1 was treated with nickel sulfate 30
g/, connected to the cathode in an aqueous solution of boric acid 30 g/,
When electricity was applied for 60 seconds at 20°C and D.C.20V, it was colored bronze.

On the other hand, a black ultraviolet curable resin paint (Daikiyu Co., Ltd., Dainippon Ink Co., Ltd.) was applied to the entire surface of one side of the starch thin film.
UV ink (SSK type) is applied to a thickness of 30 μm, and a high-pressure mercury lamp (output
2KW) for 2 seconds to partially cure the UV-curable resin paint.

After applying such a thin film to the surface of an aluminum plate using hydraulic pressure in the same manner as in Example 1, it was heated at 60°C.
When the thin film and hardened UV-curable resin paint are removed using a warm water shower, uncured wood grain-like UV-curable resin paint remains on the surface of the aluminum plate.
A wood grain-like black pattern was generated on the surface of the bronze-colored aluminum plate.

When the aluminum plate in this state was irradiated with ultraviolet rays for 2 seconds using the above-mentioned high-pressure mercury lamp, it was cured into a black grain-like pattern to form a coating layer that was firmly integrated with the aluminum plate.

Example 3 Aluminum alloy A6063S, which had been pretreated and anodized in the same manner as in Example 1, was treated with 200% phosphorous acid.
After connecting to the anode in a bath and applying electricity for 4 minutes at 20℃ and D.C.10V, 10g of stannous sulfate/,
A green colored film was produced by applying electricity for 1 minute at 20° C. and 20 VAC in a bath containing 10 g of sulfuric acid and 10 g of sulfosalicylic acid.

This aluminum alloy was immersed in a pure water bath at 80°C for 5 minutes, and then dried in an atmosphere at 80°C for 2 minutes.

On the other hand, a yellow ultraviolet curable resin paint (Dainippon Ink Co., Ltd.
Apply Daikyure Co., Ltd. UV ink SSK type),
A high-pressure mercury lamp (output 2KW)
UV rays were irradiated for 1 second to partially cure the UV curable resin coating.

After applying such a thin film to the surface of the aluminum plate using hydraulic pressure in the same manner as in Example 1, room temperature water was sprayed using a jet shower to remove the thin film and the resin paint that had hardened into a polka dot pattern, resulting in a yellow color. A colored pattern was formed by the uncured resin paint and the colored film scattered in a polka dot pattern.

Note that when the aluminum alloy in this state was irradiated with ultraviolet rays for 2 seconds using the high-pressure mercury lamp, the yellow uncured portion was hardened and integrated with the colored aluminum film.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the state of ultraviolet irradiation, Figure 2
The figure is a cross-sectional view of a thin film showing the cured and uncured parts of the UV-curable resin, Figure 3 is a schematic diagram showing how the thin film is adhered by using hydraulic pressure, and Figure 4 is the uncured UV-curable resin attached. FIG. 3 is a sectional view showing aluminum in a state where Code, 1... Ultraviolet source, 2... Thin film, 6... Ultraviolet curable resin paint, 6a... Cured portion, 6b...
...Unhardened portion, 7... Aluminum.

Claims (1)

[Claims] 1 By partially irradiating the ultraviolet curable resin paint coated on the entire surface of the thin film with ultraviolet rays, the ultraviolet curable resin paint is partially cured, and the surface coated with the ultraviolet curable resin paint on this thin film is anodized with aluminum. After adhering the uncured part of the UV-curable resin paint to the anodic oxide film, the thin film and the cured UV-curable resin paint are removed, allowing the uncured UV-curable resin paint to be applied onto the aluminum surface. A patterned surface treatment method for aluminum, characterized by generating a pattern using a curable resin paint.