JPS60202770A - Surface treatment of aluminum or aluminum alloy - Google Patents

Abstract

PURPOSE:To form an efficient coated film which is grained just like real grain by coloring a surface-treated aluminum material, then offsetting, and finally top-coating. CONSTITUTION:An aluminum or an aluminum alloy material is chemically treated or anodically oxidized, and then colored. Subsequently, desired grain patterns are offset, and a transparent coated film is formed thereon as the final top coat. Grain pattern just like a real tree is surely formed in this way, and the coated film is provided with excellent resistance to corrosion and abrasion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method for forming a wood grain pattern on aluminum or aluminum alloy materials.

In recent years, it has become desirable for indoor fittings such as shoji screens made of aluminum or aluminum alloy materials to have a wood grain feel.
For this reason, there has been an increasing demand for forming wood grain patterns on the surfaces of such interior fittings.

Conventionally, methods for forming wood grain patterns on the surface of aluminum and aluminum alloy materials include forming a wood grain pattern by electrolytic treatment in a special electrolytic bath, and then coloring the surface by electrolytic coloring, and printing the wood grain pattern. Methods include pasting vinyl chloride resin sheets, paper, etc., floating a film with a wood grain pattern printed on the liquid surface, and using liquid pressure to transfer and cover the wood grain pattern onto the surface of aluminum and aluminum alloy materials. However, in the conventional method, processing one culm is complicated and the processing equipment is expensive, so there is a problem of high processing cost, and the wood grain pattern formed according to the conventional method has a sufficient sense of wood grain. There is a problem that the wood grain pattern is not expressed properly and lacks the appearance of a real book, and the corrosion resistance of the wood grain pattern surface
There is a problem that the wear resistance is inferior.

The present invention has been made in order to improve the above-mentioned situation, and it is possible to reliably form a wood grain pattern with a wood grain feel similar to a real book on the surface of aluminum or aluminum alloy material, and it also has good corrosion resistance and abrasion resistance. It is an object of the present invention to provide a surface treatment method for aluminum or aluminum alloy material, which can provide a surface with a wood grain pattern easily and inexpensively with simple treatment steps and operations.

That is, in order to achieve the above object, the present invention performs a chemical conversion treatment or an anodic fermentation treatment on an aluminum or aluminum alloy material, then performs a coloring treatment on its surface, and then performs offset printing to form a desired wood grain pattern, Finally, by forming a transparent coating film as a top coat, a wood grain pattern is formed on the surface of the aluminum or aluminum alloy material.

The present invention will be explained in more detail below.

The surface treatment method for aluminum or aluminum alloy material of the present invention is to first perform pretreatment such as degreasing and etching according to a conventional method, and then to perform chemical conversion treatment or anodization treatment on the aluminum or aluminum alloy material. By first forming a chemical conversion film or an anodic oxide film on aluminum or aluminum alloy material, its corrosion resistance can be improved and the adhesion of the coating film formed on this chemical conversion film or anodic oxide film can be significantly improved. It is something.

Here, various treatment methods can be applied as the chemical conversion treatment, but chromate film treatment and boehmite film treatment are particularly preferably employed.

Although the bath used for the chromate film treatment of aluminum and aluminum alloy materials is not necessarily limited, a chromate bath consisting of ordinary chromic acid and a film formation accelerator is suitable. As the processing conditions, usual conditions may be employed, such as a temperature of 15 to 40° C. and an immersion time of 1 to 5 minutes.

Further, demineralized water or pure water is used as the bath for the boehmite film treatment, and an amine compound or the like may be added thereto as a film accelerator, if necessary.

The treatment conditions are preferably bath water at 95° C. or higher, more preferably boiling point, and the immersion time is preferably 5 to 30 minutes.

Furthermore, the bath used for anodizing the aluminum or aluminum alloy material is not necessarily limited, but a normal sulfuric acid bath is preferably used. Also, the electrolysis conditions may be normal conditions, such as a current density of 1 to 3 A/d, a bath temperature of 15 to 25° C., and an electrolysis time of 10 to 40 minutes. In this case, the thickness of the anodic oxide film is preferably 5 to 15 μm.

After chemical conversion treatment or anodic oxidation treatment is performed on aluminum or aluminum alloy material to form a chemical conversion film or anodized film, no coloring treatment is performed on the surface. The purpose of this coloring process is to provide an undercoat for the next process of woodgrain pattern printing (7j offset printing).The combination of this coloring process (undercoat process) and offset printing to form the woodgrain pattern creates a woodgrain feel. It was possible to form a well-expressed wood grain pattern that looks exactly like a real book.

In this case, coloring treatment methods include chemical conversion coating and lIj!
Appropriate methods such as dyeing or electrolytic coloring of the polar oxidized oxidized film may be employed, but most preferably an undercoating process is performed on the chemical conversion film or anodic oxidized film to form a coating film. By forming such a base coat, the metallic color of the aluminum or aluminum alloy material can be reliably hidden, and the appearance of real wood grain can be reliably emphasized.

The paint used to form the coating film by this undercoating process is, for example, an acrylic-urethane pigmented thermosetting paint, and an appropriate coating method such as an electrostatic coating method, an electrodeposition coating method, or a spray method is used. Painting method is adopted and painted. The color is appropriately selected depending on the color, pattern, etc. of the printed area formed by offset printing, but it is preferable that the coating film be opaque. In addition, the thickness of this coating film is 15 to 2
It is preferable that the thickness is 0μ.Furthermore, the coating film may be formed on the entire surface of the chemical conversion film or the anodic oxide film, or may be formed on a necessary part. Here, since this coating film is formed on a chemical conversion coating or an anodic oxide coating, it has good adhesion and is unlikely to peel off.

After the above-mentioned coloring process, offset printing is performed to form a wood grain pattern on this colored film.By adopting the off-hit printing method to form the wood grain pattern, we are able to create a real product that fully expresses the feeling of wood grain. To easily and reliably form a woodgrain pattern resembling a book on the surface of a profile for indoor fittings, etc. without any trouble. Note that the offset printing method employed here is the same as that used for ordinary offset printing, and normal offset printing ink is used, but the transfer roll A polyurethane resin or other elastic material with a Shore hardness of 5 to 50 degrees, especially 10 to 20 degrees is used as the transfer roll, and the transfer roll is directly or indirectly heated or cooled.
The most preferable method is to print while maintaining the temperature in the range of 15 to 50°C, especially 20 to 35°C, and by this, the softness, elasticity, and recovery of the transfer roll are controlled, and the surface to be printed is free from curved parts or irregularities. It is also possible to reliably print on a printing medium having multiple copies. Further, offset printing is not limited to one time, but can be repeated multiple times as necessary.

In J3 of the present invention, after printing Offcera 1, a transparent coating film is finally formed as 1 to Tsubuko 1. By forming this transparent coating film (top coat), the wood grain pattern is protected, and the wood grain pattern is protected. It is possible to reliably retain the wood grain pattern without the inconvenience of the pattern disappearing due to abrasion, etc., or being scratched, and it improves the corrosion resistance and abrasion resistance of the surface on which the wood grain pattern is formed, and prevents scratches and stains. etc., then <<-a.

Here, the paint used to form the transparent coating film may be any clear paint, but paints that are relatively hard and wear-resistant are particularly preferred, such as urethane-acrylic, polyester-acrylic, etc. UV curing type, thermosetting type paints such as Hoxy acrylic type, Spiran-acrylic type, etc. are used, and the coating is performed by static N coating method, spraying method, or other appropriate coating method. In addition, it is preferable that the film thickness of this transparent coating film is 5-10 micrometers. Further, the optimum hardness is 7H to 8H in terms of pencil hardness.

According to the present invention, as described above, first, aluminum or aluminum alloy material is subjected to chemical conversion treatment or anodization treatment, and then coloring treatment is performed on the surface thereof, and then offlet printing is performed to form a desired wood grain pattern, and finally, It is characterized by forming a transparent coating film as a top coat on the surface of the aluminum or aluminum alloy material, which makes it possible to easily and inexpensively form a wood grain pattern that looks exactly like a real book on the surface of aluminum or aluminum alloy material. The wood grain pattern is protected by a transparent coating film to reliably prevent scratches, etc., and is formed in a surface condition with good corrosion resistance and wear resistance.Therefore, the wood grain pattern of the present invention is formed. This surface treatment method is suitably employed when forming a wood grain pattern on the surface of indoor fittings such as shoji screens made of aluminum or aluminum alloy materials.

Next, the present invention will be explained in detail by showing two examples.
The invention is not limited to the following examples.

[Example 11 Aluminum profile for forming shoji (A-6063)
After performing degreasing and etching treatment using a conventional method, the surface of the aluminum profile is coated with chromate 1 using a chromer treatment bath consisting of chromic acid and a film accelerator, and subjected to infiltration treatment at air temperature for 5 minutes. - Formed a film. On this chromate film, a pigmented thermosetting acrylic paint (cream color) was used to form a coating film of approximately 20 μm by air spray.
Heat cure Iζ at 0°C for 30 minutes.

Next, offset printing was performed on this coating film using a sepia-colored acrylic ink to form a wood grain pattern.

Finally, a coating film of about 10 μm was formed on the woodgrain pattern printed area by air spraying using a matte transparent thermosetting acrylic paint. This was heated and cured at 150''C for 30 minutes.

The wood grain pattern formed in this manner sufficiently expressed the sense of wood grain and the sense of transparency. Furthermore, the effect was maintained over a long period of time due to the protection of the transparent coating.

[Example 2] A wood grain pattern was formed in the same manner as in Example 1, except that boehmite film treatment was performed instead of the chromate film treatment in Example 1.

Here, the boehmite film treatment was performed using demineralized water with a resistance of 500,000 Ω-1 or more, a bath temperature of 98° C. or more, and a treatment time of 30 minutes.

The obtained wood grain pattern had the same effect as in Example 1.

[Example 3] Aluminum profile for forming shoji (6063 material)
After degreasing and etching in a conventional manner, anodizing was performed at room temperature for 30 minutes at a current density of 1.5 A/d-# using a 15% sulfuric acid bath to form an anodic oxide film of about 12 μm.

This anodic oxide film was electrostatically coated using a pigmented afrylular renotane paint (beige color) to form a beige paint film of about 20 μm, which was baked and dried at 120° C. for 5 minutes.

Next, offset printing was performed on this coating film using a sepia colored acrylic ink to form a wood grain pattern.

Finally, electrostatic coating was performed on the wood grain pattern printed area using a clear urethane-acrylic ultraviolet curable paint to form a transparent coating film of about 10 μm.

After pre-drying this at 60° C. for 5 minutes, it was irradiated with ultraviolet rays using a high-pressure water lamp to cure the coating film.

The wood grain pattern formed in this manner sufficiently expressed the sense of wood grain, and its effect was maintained over a long period of time due to the protection of the transparent coating film.

Applicant: Fuji Sash Co., Ltd. Agent: Patent Attorney Takashi Kojima

Claims (1)

[Claims] 1. After chemical conversion treatment or anodic oxidation treatment is applied to aluminum or aluminum alloy material, the surface thereof is subjected to coloring treatment, then offset printing is performed to form a desired wood grain pattern, and finally a top coat is applied. 1. A method for surface treatment of aluminum or aluminum alloy for forming a wood grain pattern on the surface, characterized by forming a transparent coating film. 2. The method according to claim 1, wherein an under-painting treatment is performed as a coloring treatment in the chemical conversion treatment or anodizing treatment 4P.