JPH0813196A - Aluminum material having composite electrodeposition coating film and its production - Google Patents

Abstract

PURPOSE:To obtain such an aluminum material that although it has an electrodeposition coating film, various kinds of appearance and color tones can be realized, and to obtain the production method. CONSTITUTION:This aluminum material having a composite electrodeposition coating film is obtd. by forming a base coating film on the surface of the aluminum base and laminating two or more kinds of electrodeposition coating films of different color tones on the base film. At least the uppermost layer is made light-transmissible. The aluminum material having the composite electrodeposition coating films is produced by treating the aluminum base body, successively electrodepositing films using two or more kinds of coating materials of different color tones, and using a light-transmissible coating material for at least the last electrodeposition coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum material having an electrodeposition coating film which has been electrodeposition coated for the purpose of coloring, anticorrosion, aesthetics and the like, and a method for producing the same, and particularly to electrodeposition over a plurality of layers. The present invention relates to an aluminum material having a composite electrodeposition coating film having a coating film formed thereon and a method for producing the same. In addition,
In this specification, the term aluminum is used to include both aluminum and aluminum alloys.

[0002]

2. Description of the Related Art The surface of an aluminum base material may be coated for the purpose of coloring, anticorrosion, and appearance. As such a coating method, spray coating, electrostatic coating, dip coating, electrodeposition coating, etc. are known.
An electrodeposition coating method using electrophoresis is widely used because it can form a uniform film even on an aluminum material having a complicated shape and is advantageous for mass production.

When performing the above-mentioned electrodeposition coating, it is common practice to form an undercoat by subjecting an aluminum base material to anodizing treatment, chemical coating treatment or the like in advance, for the purpose of improving adhesion with the electrodeposition coating film. It is being appreciated. In addition, as a paint for electrodeposition coating, a transparent paint with luster or matte that makes the best use of silver white of an aluminum base, and a colored paint such as white or black are used.

[0004]

However, conventionally,
The above electrodeposition coating uses a single paint after surface treatment.
Since it was performed only once, the appearance color tone of the aluminum material after painting was determined by the color tone of the electrodeposition coating film, so the color tone had to be monotonous, and it corresponds to a wide range of aluminum material applications. There was a problem that it was not possible to obtain the desired color tone. The present invention has been made for the purpose of solving the above problems, and an aluminum material which has an electrodeposition coating film and can realize various appearance tones and a method for producing the same. To do.

[0005]

In order to achieve the above-mentioned object, an aluminum material having a composite electrodeposition coating film of the present invention has an undercoating film formed on the surface of an aluminum base material. Two or more kinds of electrodeposition coating films having different color tones are laminated and formed on the surface, and at least the uppermost electrodeposition coating film is transparent.

Further, in the method for producing an aluminum material having a composite electrodeposition coating film, after the aluminum base material is subjected to a base treatment, two or more kinds of coating materials having different color tones are used, and the respective coating materials are sequentially subjected to electrodeposition coating. In addition, at least the final electrodeposition coating is performed using a translucent coating. The material of the aluminum base material to which the present invention is applied is not particularly limited, and pure aluminum and various aluminum alloys can be widely applied.

The undercoat is interposed for the purpose of improving the adhesion of the electrodeposition coating to the aluminum substrate. The type of undercoating for forming this undercoating is not particularly limited, and examples thereof include anodizing treatment and chemical coating treatment which are performed as conventional undercoating for electrodeposition coating. The thickness of the undercoat is similar to the conventional one and it is 3 to 20μ.
About m is preferable.

According to the present invention, two or more kinds of electrodeposition coating films having different color tones are laminated so that a new delicate color tone different from that of each single electrodeposition coating film is revealed.
Here, the color tone of the electrodeposition coating film or coating material includes not only the lightness and hue of the coating film but also gloss, and even the same color coating material may be used in combination with a glossy coating material and a matte coating material. Further, in order to bring out a new color tone by the composite electrodeposition coating film, it is necessary that at least the uppermost electrodeposition coating film is translucent and does not hide the color tone of the lower electrodeposition coating film too much. is there. The translucent electrodeposition coating film is not limited to a transparent coating film, but may be a coating film with a colored coating as long as it has a concealing power such that the color tone of the lower electrodeposition coating film can be seen through the uppermost layer. good. Therefore, as the coating material, any matte or glossy transparent coating material that has been conventionally used, or any colored coating material such as white or black can be used as long as it is a combination in consideration of the translucency of the coating material used for the uppermost layer. In the case of three or more electrodeposition coating films, the color tone of all of these electrodeposition coating films may be combined by making each film translucent except for the lowermost electrodeposition coating film. The more layers of the electrodeposition coating film to be combined, the richer the variety of overall color tones obtained.

In addition to the above, when all electrodeposition coating films are made transparent, the color tone of the undercoat film appears in a transmissive state. Therefore, the color tone of the undercoat film should also be incorporated in the components of the overall color tone. You can In this case, by coloring the undercoat in various color tones by electrolytic coloring or the like, it is possible to further increase the types of overall color tones obtained.

To laminate two or more electrodeposition coating films,
Electrodeposition coating may be sequentially performed on each of two or more kinds of coating materials. Since each electrodeposition coating method is the same as the conventional method,
It is sufficient to repeat the electrodeposition coating for the number of layers of coating, and the existing electrodeposition coating equipment can be used as it is. The thickness of the electrodeposition coating film is preferably about 4 to 30 μm for each film, and about 15 to 45 μm for the laminated composite electrodeposition coating film.

The composite electrodeposition coating film formed as described above is usually finished by further drying or baking.

[0012]

In the aluminum material according to the present invention, an undercoating film is formed on the surface of an aluminum base material, and two or more kinds of electrodeposition coating films having different color tones are further laminated on the surface, and at least the uppermost layer is formed. The electrodeposition coating film is translucent. Therefore, the color tone of the lower electrodeposition coating film appears through the uppermost electrodeposition coating film, or the color tone of the base film appears through the composite electrodeposition coating film, and the appearance color tone of the aluminum material is the same as that of each electrodeposition coating film. Mixed colors or mixed colors of these electrodeposition coating films and the undercoating film, exhibiting a delicate color tone that cannot be exhibited by a single electrodeposition coating film.

Further, in forming such a composite electrodeposition coating film, two or more kinds of paints having different color tones are used for an aluminum substrate which has been subjected to a base treatment, and the respective electrodepositions are sequentially subjected to electrodeposition coating. And at least the final electrodeposition coating need only be performed using a translucent paint,
An aluminum material having a composite electrodeposition coating film can be easily manufactured.

[0014]

EXAMPLES Next, specific examples of an aluminum material having a composite electrodeposition coating film of the present invention and a method for producing the same will be described. In each of the examples and comparative examples, JIS A6063 aluminum extruded profile was used as the aluminum base material. In addition, the paint is a transparent matte baking electrodeposition paint (manufactured by Kansai Paint Co., Ltd., product name "Electron AG
-320 "), transparent glossy electro-deposition paint (manufactured by Kansai Paint Co., Ltd., trade name" Electron AG-200 "), white electro-deposition paint (manufactured by Kansai Paint Co., Ltd., trade name" Electron AG-200W " ]) Was used.

In the following Examples 1 and 2 and Comparative Examples 1 and 2, the aluminum base material was anodized by immersing the aluminum base material in an electrolytic solution of sulfuric acid as a base treatment, and the thickness was about 12 μm.
The oxide film of No. 1 was formed, washed with water and washed with hot water, and subsequently subjected to the electrodeposition coating treatment described in detail below to form an electrodeposition coating film.

(Example 1) An aluminum substrate having an oxide film formed thereon was dipped in the transparent matte baking electrodeposition coating composition,
By applying electricity at a constant voltage of 130 V for 90 seconds, electrodeposition coating was performed to form a primary electrodeposition coating film. Subsequently, the aluminum base material was washed with water, dipped in the white baking electrodeposition coating composition, and subjected to electrodeposition coating by energizing at a constant voltage of 250 V for 180 seconds to form a secondary electrodeposition coating film in layers.
Further, the aluminum material thus formed with the two-layer composite electrodeposition coating film was washed with water and then baked.

(Example 2) An aluminum base material having an oxide film formed thereon was dipped in the transparent matte baking electrodeposition coating composition,
By applying electricity at a constant voltage of 100 V for 180 seconds, electrodeposition coating was performed to form a primary electrodeposition coating film. Subsequently, the aluminum base material was washed with water, dipped in the white baking electrodeposition coating composition, and subjected to electrodeposition coating by energizing at a constant voltage of 250 V for 180 seconds to form a secondary electrodeposition coating film in layers. Further, the aluminum material thus formed with the two-layer composite electrodeposition coating film was washed with water and then baked.

(Comparative Example 1) An aluminum base material having an oxide film formed thereon was dipped in the above-mentioned white baking electrodeposition coating composition, and was electrically electrodeposited at a constant voltage of 190 V for 4 minutes to form a coating film. Further, in this way, the aluminum material having the one-layer electrodeposition coating film formed thereon was washed with water and then baked.

(Comparative Example 2) An aluminum substrate on which an oxide film was formed was dipped in a transparent matte baking electrodeposition coating, and the electrodeposition coating was carried out by applying a constant voltage of 130 V for 90 seconds to form an electrodeposition coating film. Formed. Further, the aluminum substrate on which the one-layer electrodeposition coating film was formed in this manner was washed with water and then baked.

Next, with respect to each aluminum material on which the composite electrodeposition coating film was formed as described above, the color difference and the gloss value were measured, and the color tone of the surface was examined. The color difference is measured by lightness (L), bluish (a) and yellowish (b) using a color difference meter CDE-CH-4 manufactured by Suga Test Instruments Co., Ltd., and the gloss value (%) is an incident light angle. Was measured based on the reflected light when the angle was 45 °. Table 1 shows the composition and color tone of the composite electrodeposition coating film. In the table, the lightness (L) becomes whitish as the numerical value becomes larger, the bluish (a) shows a reddish tone when the value is +, the negative value is a bluish green tone, and the yellowness (b) is a yellow value when the value is +. , -Value indicates that a blue color tone is exhibited.

[0021]

[Table 1]

In the following Examples 3 and Comparative Examples 3 and 4, the aluminum material was anodized by immersing the aluminum material in an electrolytic solution of sulfuric acid as a surface treatment to form an oxide film having a thickness of about 12 μm. Wash with water, then nickel sulfate 50
g / l, boric acid 30 g / l, pH 4.5, bath temperature 30 ° C., soaked in an electrolytic solution, and a carbon electrode is used as a counter electrode for 3 minutes at an alternating current of 18 V to carry out secondary electrolysis, thereby forming an anodized film. Was subjected to a bronze coloring treatment. Then, the colored aluminum substrate was washed with water and hot water, and each electrodeposition coating treatment described in detail below was performed to form an electrodeposition coating film.

(Example 3) An aluminum base material whose oxide film was colored was dipped in the transparent matte-baking electrodeposition coating, and the electrodeposition coating was performed by applying a constant voltage of 130 V for 90 seconds to perform the primary electrodeposition coating. A film was formed. Subsequently, the aluminum base material was washed with water, dipped in the transparent glossy baking electrodeposition coating, and then electroplated by applying a constant voltage of 180 V for 2 minutes to form a secondary electrodeposition coating film by lamination. . Further, the aluminum material thus formed with the two-layer composite electrodeposition coating film was washed with water and then baked.

(Comparative 3) An aluminum base material having a colored oxide film was immersed in the transparent matte baking electrodeposition coating composition,
By applying electricity at a constant voltage of 180 V for 3 minutes, electrodeposition coating was performed to form an electrodeposition coating film. Furthermore, in this way 1
After the electrodeposition coating film of the layer was formed, the aluminum material was washed with water and then baked.

(Comparative Example 4) An aluminum base material having a colored oxide film was immersed in the transparent glossy baking electrocoating material and electroplated by applying a constant voltage of 180 V for 3 minutes to carry out electrocoating. Was formed. Further, the aluminum material thus formed with the one-layer electrodeposition coating film was washed with water and then baked.

Next, with respect to each aluminum material on which the electrodeposition coating film was formed as described above, the surface color tone was examined in the same manner as in Example 1 described above. Table 2 shows the composition and color tone of the electrodeposition coating film.

[0027]

[Table 2]

In Table 1, Examples 1 and 2 and Comparative Examples 1 and 2
By comparing with, it was confirmed that the composite electrodeposition coating film has different color tone from each of the single electrodeposition coating films by forming the composite electrodeposition coating film with two kinds of paints having different color tones. I got it.

In Table 2, Example 3 and Comparative Example 3,
Comparing with No. 4, by forming a composite electrodeposition coating film with paints of two types with different gloss, the composite electrodeposition coating film exhibits a gloss intermediate between two single electrodeposition coating films and changes in gloss level. I was able to confirm that I could turn on.

[0030]

As described above, in the aluminum material having the composite electrodeposition coating film of the present invention, the undercoat film is formed on the surface of the aluminum base material, and the surface of the undercoat film has different color tones. Since at least one electrodeposition coating film is laminated, and at least the uppermost electrodeposition coating film is translucent, the appearance color tone of the aluminum material is a mixture of the electrodeposition coating films or these electrodeposition coating films. It becomes a color mixture with the undercoat, giving a delicate color tone that cannot be achieved with a single electrodeposition coating. As a result, aluminum materials having various appearance tones are possible, and a wide range of uses of aluminum materials can be accommodated.

Further, in the method for producing the composite electrodeposition coating film, after the aluminum base material is subjected to a base treatment, two or more kinds of paints having different color tones are used, and each of the paints is sequentially subjected to electrodeposition coating, and at least the final coating. Since the electrodeposition coating is performed using a translucent paint, the individual electrodeposition coating steps can be performed by the same steps as the conventional ones, and the existing equipment can be used as is to easily perform composite electrodeposition coating. An aluminum material having a coating film can be manufactured.

Claims (2)

[Claims] 1. An undercoating film is formed on the surface of an aluminum base material, and two or more kinds of electrodeposition coating films having different color tones are laminated on the surface of the undercoating film, and at least the uppermost electrodeposition layer is formed. An aluminum material having a composite electrodeposition coating film, characterized in that the coating film is translucent. 2. After the aluminum substrate is subjected to a surface treatment,
It has a composite electrodeposition coating film characterized by using two or more kinds of paints having different color tones, sequentially performing electrodeposition coating on each paint, and at least performing final electrodeposition coating using a translucent paint. Aluminum material manufacturing method.