JPS6043440B2 - Aluminum profile with matte finish and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum profile with a matte finish and a method for manufacturing the same.

In recent years, the demand for aluminum shapes has been increasing in all fields such as building materials, ships, and vehicle materials due to the various characteristics that these shapes have, and this is truly remarkable. For the purpose of final surface finishing and surface protection, such aluminum profiles are generally subjected to various coating treatments via various underlying layers such as anodized coatings and chemical conversion coatings. However, most of the surfaces of aluminum profiles obtained by such treatment are glossy. However, recently, particularly in the field of building materials, there has been a demand for aluminum profiles having a matte finish with low gloss that provides a calm texture.

Various methods have been considered for this purpose, such as improving the paint itself or treating it with a treatment liquid that has matting properties, but each method has various problems. Incidentally, regardless of whether or not the purpose is to make the surface of an aluminum profile matte, it is known that aluminum substrates are subjected to blasting treatment (Japanese Patent Publication No. 55-1139).
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The invention described in the Japanese Patent Publication No. 1139/1980 relates to a method for continuous production of aluminum shapes, in which a hot extruded aluminum shape is blasted without any aging treatment, and then the rough An anodic oxide film is formed on the planarized shape, followed by dip coating and heat drying (simultaneously aging). However, the purpose of the blasting treatment in the above method is to improve the adhesion of the paint film, and the shot treatment is performed while the aluminum is still soft. It is difficult to obtain one with this. In other words, when an aluminum material is subjected to blasting, the surface roughens easily, resulting in a rough surface with concavities and convexities of a certain depth and size, which are then further anodized and painted. As shown in Fig. 1, even if the aluminum profile is coated, the unevenness on the surface of the material a is alleviated by the anodic oxide film and the coating film c, and the finished coating surface of the resulting aluminum shape is uniform with gentle undulations. This results in deep unevenness, and the painstakingly formed unevenness is not emphasized, making it unsuitable for matting treatment. Therefore, the object of the present invention is to
An object of the present invention is to provide an aluminum profile having an uneven surface which is obtained by a simple blasting process and has an excellent brushing effect, and a method for manufacturing the same.

As a result of the inventor's intensive research, it was found that when an aluminum profile is anodized to form an anodized film on its surface, and then blasted over the anodic oxide film, the aluminum Since the substrate 1 is softer than the anodic oxide film 2, in the areas where the concave bottom of the rough surface reaches the aluminum substrate first, the formation of depressions in the aluminum substrate is promoted more than in other areas where it has not reached the bottom, as shown in FIG. Even if a base film 4 is formed on the uneven surface as shown in FIG. The present invention has been completed based on the discovery that an aluminum profile having the following properties can be obtained.

In addition, the above effects can be achieved by applying a coating on top of the anodic oxide film.
It has been found that a similar effect can be obtained by performing a blasting treatment on top of this coating film, and an uneven surface of the composite film can be obtained. That is, the aluminum profile having a brushed finish surface according to the present invention includes an aluminum base material, an anodized film formed on the surface of the aluminum base material, and irregularities of uneven depth that reach not only the anodic oxide film but also the inside of the aluminum base material. A base film is formed on the surface of the base film, and a coating film is formed to cover the base film.

According to the present invention, the aluminum profile having the brushed finish surface is obtained by anodizing the aluminum profile to form an anodized film on its surface, and then subjecting it to a blasting treatment after painting or without painting. , by a method characterized in that a base film is then formed and coated.

To explain the present invention in detail, first, aluminum shapes are subjected to various treatments such as degreasing, water washing, etching, and neutralization according to conventional methods, and then placed in a normal acidic electrolyte such as sulfuric acid, oxalic acid, or phosphoric acid. Anodic oxidation treatment is performed to form a microporous anodic oxide film.

It is also possible to apply a coating after further washing with water or hot water, and then heat baking to form a coating film. As the coating method, various conventionally known coating methods such as dipping coating, electrodeposition coating, and spray coating can be used. The aluminum profile on which the anodic oxide film or further coating has been formed is then subjected to a blasting process.

As the blasting treatment, various blasting methods such as shot blasting, sandblasting, and liquid honing are possible. Normally, when a shot grid is used, the unevenness becomes large, and when glass beads are used, the unevenness becomes fine. Therefore, an appropriate method may be selected depending on the purpose, and the particle size of the abrasive may be set. The aluminum sections that have been blasted in this way are then subjected to treatments such as washing under water as necessary, and then some defects may occur in the adhesion with the paint film and the corrosion resistance of the paint film. Perform surface treatment.

The method is to apply a chemical conversion film treatment or a primer for base treatment. Examples of chemical conversion coating treatment include chromate method, phosphate method, and alkali oxidation method, and examples of primer for surface treatment include wash primer. These treatments have the effect of improving adhesion with paint and making it easier to paint. After that, it is washed with water, dried, cooled, etc. as necessary, then painted, set as necessary, and then heated and baked. In this case, it is of course possible to apply two coats or the like if necessary. The aluminum profile used in the present invention is pure aluminum, or contains one or more metals such as silicon, magnesium, copper, nickel, zinc, chromium, lead, bismuth, iron, titanium, and manganese. It is an alloy and is formed into any shape by extrusion processing or the like.

Next, the effects of the present invention will be further explained with reference to Examples.

Figure 3 shows a microscopic photograph (one scale is 2μ) of the surface of an aluminum material that has been directly blasted using a shot blasting machine model T-0C (manufactured by Nissho Co., Ltd.) on an extruded aluminum profile. JISBO6Ol on the surface
The surface roughness Hmax was 15.

On the other hand, FIG. 4 shows that an anodic oxide film with a thickness of 12 μm is formed on an aluminum substrate according to the present invention, and then blasting is performed on the anodic oxide film for the same period of time using the same blasting machine as above and having the same diameter. A micrograph (same magnification as in FIG. 3) of the surface of an extruded aluminum profile on which an anodic oxide film was formed is shown, and the surface roughness Hmax of this surface was 20. As is clear from comparing Figures 3 and 4, when blasting is applied to an aluminum material, the surface becomes uniformly uneven and undulating, whereas according to the present invention, blasting is performed after forming an anodized film. Due to uneven maturation of the anodic oxide film, large and small depressions, deep depressions and shallow depressions are observed, and unevenness is seen in the third layer.
It is more emphasized than in the figure. Therefore, even if it is further coated after this, it is possible to provide an aluminum profile that has depth and is well faded. Furthermore, conventionally stocked aluminum shapes have been subjected to anodizing treatment for the purpose of corrosion resistance and weather resistance.

Therefore, the method of blasting aluminum substrates has the inconvenience of being limited to always providing matte profiles. On the other hand, with the method of the present invention, which involves anodizing or painting and then blasting, it is possible to use aluminum shapes in stock, resulting in faster delivery times and extremely smooth customer support. Benefits can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of an aluminum substrate subjected to blasting, anodizing, and painting, and Fig. 2 is a schematic cross-sectional view of an aluminum substrate after an anodic oxide film is formed according to the present invention, followed by blasting, and a base film is formed. A schematic cross-sectional view when the coating is applied, Fig. 3 is a micrograph of the surface obtained by directly blasting an extruded aluminum section (1 scale = 2 μ), Fig. 4 is an anodized coating according to the present invention. A micrograph (1 scale = 2μ) of the surface obtained by blasting after formation is shown. 1 is aluminum base, 2 is anodized film, 3 is paint film,
4 is the base film.

Claims (1)

[Scope of Claims] 1. An aluminum base material, an anodized film formed on the surface of the aluminum base material, and a base film formed on the surface having irregularities of uneven depth reaching not only the anodic oxide film but also the inside of the aluminum base material, An aluminum profile having a matte finish surface, characterized by forming a coating film covering the base film. 2. A matte finish characterized by anodizing an aluminum profile to form an anodized film on its surface, followed by blasting after painting or without painting, then forming a base film and painting. A method for producing an aluminum profile with a finished surface.