JPS63297593A - Aluminum or aluminum-alloy material and its production - Google Patents

Abstract

PURPOSE:To economically manufacture an Al or Al-alloy material having a pear skin-like electrodeposited film, by applying anodic oxidation treatment to an Al or Al-alloy base material and then subjecting the above to anodic electrodeposition in a coating bath prepared by adding water-insoluble resin content to water-soluble resin content. CONSTITUTION:Anodic oxidation treatment is applied to an Al or Al-alloy base material to form an anodic oxidation film, preferably, of >=about 9mum thickness. Subsequently, anodic electrodeposition is applied to the above base material by using a coating bath for anodic electrodeposition prepared by adding resin content of limited water solubility or water-insoluble resin content to water-soluble resin content. It is suitable that about 5-12wt.% water-soluble acrylmelamine resin, etc., are added as the above water-soluble resin content and also about 1-8% carboxylic acid-type polymer, etc., are added as the above-mentioned resin content of limited water solubility or water-insoluble resin content. By the above treatment, a pear skin-like electrodeposited coating of <=8% 60 deg. relative-specular glossiness is formed on the anodic oxidation film, preferably, to >=about 7mum thickness. By this method, the Al or Al-alloy material which has inorganic texture and in which marks on the base material, such as die marks, are covered can be obtained.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is used as building materials, furniture, etc., and has a unique color tone with a satin-like inorganic texture, and has traces such as die marks and rolling marks. The present invention relates to a concealed aluminum or aluminum alloy material and a method for manufacturing the same.

As is well known, die marks and the like are likely to occur on the surface of aluminum or aluminum alloy base materials during the manufacturing process, for example during extrusion. is viewed as a problem because it impairs the aesthetic appearance of the base material.

Conventionally, methods for erasing die marks on the surface of aluminum or aluminum alloy substrates include polishing/grinding treatment,
Mechanical pretreatments such as blasting and chemical pretreatments such as satin finish and etching are generally employed.

However, one mechanical pretreatment requires extra equipment, and especially in the polishing/grinding process, there is a drawback that it is not possible to treat the concave portions of the extruded aluminum profile, which has many concavities and convexities.

On the other hand, among chemical pretreatments, the satin finish treatment requires the use of expensive treatment agents. In addition, since the etching process requires a long time, the amount of dissolved aluminum from the aluminum material increases, and with this increase in the amount of dissolved aluminum, the regeneration load of the etching solution and the processing load of the aged solution increase, and furthermore, the amount of dissolved aluminum increases. Problems arise such as the thickness of the shape becoming thinner after processing. Furthermore, when using this etching process to process aluminum extruded sections on a vertically suspended process line, the etching cannot be done deeply, so the die marks cannot be sufficiently erased, and die mark defects are easily identified. Furthermore, the etching process has the disadvantage that it is difficult to employ in conventional composite film processing lines because the cycle time is out of order.

The present invention was developed in view of the above circumstances, and by forming a satin-like electrodeposited coating film with unprecedented excellent characteristics on an anodized film, traces such as die marks and rolling marks on the substrate can be hidden. It is an object of the present invention to provide an aluminum or aluminum alloy material, and to provide a method for manufacturing such aluminum or aluminum alloy material economically and industrially.

Means and Uses for Solving the 10 Problems The inventors have:
As a result of intensive studies to achieve the above objectives, we developed a paint bath for anodic electrodeposition coating in which an aluminum or aluminum alloy base material was anodized, and then a slightly water-soluble or water-insoluble resin was added to the water-soluble resin. When an electrocoated film with a 60° specular gloss of 8% or less is formed by anodic electrodeposition using anodic electrodeposition, countless irregularities of about 1 to 30 μ in the form of fine background patterns are uniformly formed on the anodic oxide film. A satin-like electrodeposition coating film is obtained, and this coating erases the metallic texture of the anodic oxide film and gives a unique color tone with an inorganic texture. Alloy materials cause diffuse reflection of light due to the synergistic effect of scattered light from the coating surface and reflected light from the base material surface.
This coating film has an excellent effect of erasing traces such as die marks and rolling marks on aluminum or aluminum alloy base materials.
In particular, this effect is excellent when the 60° specular gloss of the translucent matte electrodeposition coating film is 8% or less. The present inventors discovered that contamination with fats and oils is less likely to occur and maintains a good appearance, and that the above-mentioned method can be directly introduced into ordinary lines and is economically and industrially advantageous.5 The present invention has been made. reached.

Therefore, in the present invention, an anodic oxide film is formed on the surface of an aluminum or aluminum alloy base material, and a satin-like electrodeposition coating film having a 606 specular gloss of 8% or less is formed on this anodic oxide film. Aluminum or aluminum alloy material characterized by being made of aluminum, and aluminum or aluminum alloy base material subjected to anodizing treatment, and then a poorly water-soluble or water-insoluble resin component is added to the water-soluble resin component for anodic electrodeposition coating. The present invention provides a method for producing aluminum or an aluminum alloy, characterized in that anodic electrodeposition is performed using a paint bath to form a satin-like electrodeposited coating film having a 60" specular gloss of 8% or less.

The present invention will be further explained below.

In the method for producing an aluminum or aluminum alloy material according to the present invention, first, an aluminum or aluminum alloy base material is anodized to form an anodized film.

In this case, the aluminum or aluminum alloy base material is selected depending on the application, etc., and the anodization treatment can be performed according to a conventional method, but it is preferable to form an anodic oxide film of 9 tones or more from the viewpoint of corrosion resistance. .

Next, in the method of the present invention, this anodic oxide film is subjected to anodic electrodeposition using a paint bath for anodic electrodeposition that is capable of forming a satin-like paint film with a 60° specular gloss of 8% or less. give

Here, as the paint bath for anodic electrodeposition coating, a paint bath is used in which a poorly water-soluble or water-insoluble resin component having different compatibility with the water-soluble resin component is added to the water-soluble resin component.

In this case, there is no particular restriction on the water-soluble resin component, and ordinary water-soluble resin components can be used, but water-soluble acrylic melamine resins are particularly preferably used. Furthermore, the poorly water-soluble or water-insoluble resin content is not particularly limited, and examples include carboxylic acid, alkyd, acrylic-alkyd, melamine, urea, epoxy, polyurethane, polyethylene, polyamide, vinyl chloride, and fluorine. One type or two or more types of resins consisting of polymers of the above-mentioned type can be used, and it is particularly preferable to use resins that have significantly different compatibility with the water-soluble resin component, which is a paint bath component. Specifically, the paint bath made by adding a resin component has a molecular weight of 20,000~
Acrylic resin made by polymerizing about 50,000 methyl methacrylic acid, butyl methacrylic acid, etc. and a molecular weight of 350 to 1.
A modified acrylic resin paint made by adding a poorly water-soluble acrylic melamine resin with a molecular weight of 100,000 to 150,000 to a water-soluble acrylic melamine resin composed of a melamine resin made by adding an appropriate 3M body to mono- and dimers of about 000. You can use a bath etc.

In this case, the amount of resin added is 5 to 12% by weight, especially about 10% by weight of water-soluble resin to the entire bath, and 1 to 8% by weight of poorly water-soluble or water-insoluble resin.
In particular, it is preferably 1 to 5% by weight, and the total resin concentration is preferably about 8 to 12% by weight of the entire bath.

Further, the conditions for anodic electrodeposition coating are the same as those for normal treatment, with the object to be treated being the anode and stainless steel etc. being the cathode at 120 to 250 V, more preferably 140 to 250 V.
Apply a DC voltage of about 0 V and apply 1 at a bath temperature of 15 to 25°C.
The treatment time can be ~10 minutes, more preferably about 2 to 5 minutes, but from the point of view of forming the best satin-like electrodeposition coating film, a current application time of 3 to 4 minutes at about 180°C is sufficient. .

Furthermore, in this electrodeposition coating, the resulting satin-like electrodeposition coating film forms a coating film with a 60° specular gloss of 8% or less, more preferably 2 to 5%, and @
The film thickness is preferably 7 or more.

It is preferable that this satin-like electrodeposition paint film has a translucent milky white color, but in particular, the electrodeposition paint is poured onto the heat-resistant transparent glass surface and set.
After baking for 30 minutes at ℃, Y value (lightness) as tristimulus value
When measured and using this Y value as the translucency criterion, the Y value of an unpainted heat-resistant transparent glass plate and a heat-resistant transparent glass plate coated with a conventional transparent electrodeposition paint is 1.94.

The type of resin added in the paint bath and the coating film thickness are appropriately adjusted so that the Y value is preferably 2 to 10, more preferably 2.5 to 5, and a translucent satin-like electrodeposition coating film is obtained. is preferred.

After the electrodeposition coating process, excess paint is washed away with water, then air-dried and dried to harden.The conditions include, for example, air-drying at room temperature for about 5 to 10 minutes,
Baking for 30 to 40 minutes at a temperature of about V for curing can be adopted, and the optimum condition is baking at 180° C. for about 30 minutes.

The coating film of the present invention can be applied directly onto the anodized film as described above.
0" It forms a satin-like electrodeposition coating film with a specular gloss of 8% or less, and in the present invention, the above-mentioned gloss is directly applied to the anodized aluminum or aluminum alloy base material. Due to the satin-like electrodeposition coating,
The metallic texture of the anodic oxide film is erased, giving it an inorganic texture, and the surface of the resulting coating film has countless irregularities in the form of a fine background pattern, which makes it difficult to create dice marks on aluminum or aluminum alloy substrates. It has the property of being excellent in hiding properties, and is especially excellent in that it provides a coating film with a 60° specular gloss of 8% or less, more preferably 2 to 5%.

To explain in more detail, the satin-like electrodeposition coating film has a color of 1 to 304.
A conventional matte coating film has large irregularities formed at considerable intervals (
Compared to the large undulations formed on the anodic oxide film (approximately 5 to 70 mm), countless fine irregularities are uniformly formed, and when a single coating film is formed in close contact with the anodic oxide film, the coating film becomes Optical properties (light reflection) change significantly. In other words, when light hits the surface of the paint film, it is scattered finely by the countless minute irregularities formed on the surface of the paint film, and the light that passes through the paint film is scattered onto the surface of the base aluminum or aluminum alloy base material. The scattered light and the reflected light synergistically cause diffused reflection, and this diffused reflection makes the remains of die marks, rolling marks, etc., which were visible as they were in conventional coatings, noticeable. This effect is especially effective when the 60″ specular gloss is 8% or less, more preferably 2 to 5%.
The coating film is excellent. In addition, this coating film is resistant to stains caused by fingerprints, and is also resistant to stains caused by oil and fat during processing.It has excellent anti-contamination properties, and even if such contamination occurs, it can be easily cleaned and removed. It is.

Effects of the Invention According to the present invention, a satin-like coating film with a 60° specular gloss of 8% or less is formed on the aluminum or aluminum alloy substrate, and this coating film can be used to remove die marks or rolling marks on the aluminum or aluminum alloy substrate. Since it is possible to hide traces such as dirt, etc., the appearance is very good, and since stains due to fingerprints and oils and fats are difficult to occur, the appearance is well maintained. Therefore, the aluminum or aluminum alloy material of the present invention can be suitably used for applications such as building materials, and the method of the present invention allows such useful aluminum or aluminum alloy materials to be produced easily, reliably, economically, and industrially. can be advantageously manufactured. Furthermore, the method of the invention has the advantage that it can be processed in conventional composite coating processing lines.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

〔Example〕

A pretreated aluminum extrusion with prominent die marks was heated at a current density of 1 in a 15% aqueous sulfuric acid solution (20°C).
, 5 A/dm2 for 30 minutes to form an anodic oxide film (thickness: 13 μs).

Next, after washing with water, anodic electrodeposition was applied using a special modified acrylic/melamine resin paint aqueous solution having the following composition and using a stainless steel plate as a counter electrode under the following conditions.

Water-soluble electrodeposition paint Composition Water-soluble acrylic resin 6% Water-soluble melamine resin 4 Slightly water-soluble melamine resin 2 Butyl cellosolve 3 Isopropyl alcohol 2 Triethylamine 0. 152-ethylhexanol 0.2 Water
−Total
100.0% by weight 1 Painting conditions Single bath concentration 12% by weight Bath temperature 20°C Applied voltage 180V Current application time 120 seconds Film thickness 14- Next, thoroughly rinsed with water, air-dried, and heated to 180°C for 30 minutes.
A coating film was formed by baking for a minute.

The coating thus obtained has a 60″ specular gloss of 3%.
It had a satin-like translucent milky white appearance, and the dice marks were not noticeable. Furthermore, this coating film was resistant to fingerprints and oil stains, and these stains could be easily removed by wiping the areas to which fingerprints and oil had adhered.

[Comparative Example 1] An extruded aluminum profile having die marks similar to those in the example which had been pretreated was treated in the same manner as in Example 1 to form an anodic oxide film (thickness: 10 mm).

Next, anodic electrodeposition was applied as a water-soluble glossy acrylic melamine resin paint in an electrodeposition paint bath called Vanillaite AL-80ON manufactured by Honey Kasei Co., Ltd. under the following conditions.

Bath concentration: 10% by weight Bath temperature: 20°C Applied voltage: 140V Current application time: 120 seconds Film thickness: 10IA Next, the film was thoroughly washed with water, air-dried, and baked at 180'C for 30 minutes to form a coating film.

The coating film thus obtained has a 60' specular gloss of 80
%, had a light metal texture, and had noticeable dice marks. [Comparative Example 2] The pretreated aluminum extruded shape was treated in the same manner as in Example] to form an anodized film (thickness: 10 IM). ) was generated.

Next, anodic electrodeposition was applied as a water-soluble matte acrylic melamine resin paint in an electrodeposition paint bath called Honey Fine manufactured by Honey Kasei Co., Ltd. under the following conditions.

Bath concentration: 8% by weight Bath temperature: 20°C Applied voltage: 180V Current application time: 120 seconds Film thickness: 12 pn Next, the film was thoroughly washed with water, air-dried, and baked at 180°C for 30 minutes to form a coating film.

The coating film thus obtained has a specular gloss of 60a and 30
%, had a light metal texture, and had noticeable dice marks.

Claims (1)

[Claims] 1. An anodic oxide film is formed on the surface of an aluminum or aluminum alloy base material, and a satin-like electrodeposition coating film having a 60° specular gloss of 8% or less is provided on the anodic oxide film. An aluminum or aluminum alloy material comprising: 2. Anodizing the aluminum or aluminum alloy base material, and then performing anodic electrodeposition using a paint bath for anodic electrodeposition coating in which a poorly water-soluble or water-insoluble resin is added to the water-soluble resin, A method for producing aluminum or an aluminum alloy, characterized in that a satin-like electrodeposited coating film having a specular gloss of 8% or less is formed.