JPS5943998B2 - Surface treatment method for aluminum or aluminum alloy material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for applying electrical treatment to the surface of a molded product such as a plate or an extruded shape made of aluminum or an aluminum alloy (these are referred to as aluminum materials in this specification). This invention relates to a method for forming beautiful wood grain patterns.

Conventionally, the method of creating patterns such as wood grain patterns on the surface of aluminum materials involves stamping predetermined score lines on the surface of the aluminum material using a roller or press mold.

A method of etching the original image by etching the surface of the aluminum material using the old photoengraving method.

(q A method in which the surface of the aluminum material is partially masked with an appropriate protective material, and then sprayed with paint, chemically dyed, or colored with an oxide film.

(By means such as O screen printing or transfer printing,
A method of printing paint or other colored materials onto the surface of aluminum materials.

In addition, there is a method in which paper or film printed with a wood grain pattern is attached to the surface of the aluminum material.

However, among these methods, the embossing method (J) is a method in which the workpiece is compressed by strongly compressing it with a pair of dies or molds, so it can only be applied to flat aluminum materials. Also, the etching method (B), the masking method (O), and the printing method (O) require a lot of time and effort in the masking process and the plate making of the wood grain pattern. However, the subsequent secondary processing is extremely troublesome, and there are problems with the durability of the pattern-forming film.Furthermore, these methods, including the pattern paper pasting method (all of them require special machinery and equipment). 1. The purpose of the present invention (well, it is not possible to use the conventional method as described above). An object of the present invention is to provide a method for forming a colored wood grain pattern without any drawbacks.

First, we will give an overview of the present invention, which has succeeded in achieving the above object. propionic acid, butanoic acid,
Oxalic acid, succinic acid, adipic acid, maleic acid, malonic acid, lactic acid, malic acid, citric acid, tartaric acid, benzolsulfonic acid, phenolsulfonic acid, sulfosalicylic acid,
A dilute aqueous solution of at least one acidic electrolyte selected from the group consisting of cresol sulfonic acid and thymol sulfonic acid, or the aqueous solution contains sodium hydroxide, sodium metasilicate, trisodium phosphate, sodium hydrogen carbonate,
Sodium metaborate, sodium sulfate, sodium carbonate, borax, sodium hydrogen sulfate or their ammonium salts, calcium salts, lithium salts, barium salts,
An aqueous solution containing one of the alkaline electrolytes of potassium salt, or (1) an aqueous solution with a similar effect as the electrolyte, can be Electrolytic treatment under conditions that generate hydrogen gas on the surface (AC electrolysis treatment)
(Q: During the above electrolysis, hydrogen gas bubbles generated on the surface of the object to be treated are caused to rise along the surface of the object to be treated:
(c) After carrying out the above electrolysis until a silver-gray white pattern is formed on the surface of the object to be treated by the explosion of the hydrogen gas bubbles, the object to be treated is treated with an inorganic acid, an organic acid, or both. (2) immersing the object to be treated after the above anodizing treatment in an inorganic coloring bath containing metal salts or (dye or pigment solution); The method is characterized by coloring the surface of the object to be treated (coloring treatment).

Hereinafter, the method of the present invention will be explained in detail in order of steps.

Aluminum material that has been pre-treated by conventional methods such as degreasing and etching is subjected to AC electrolytic treatment in an electrolytic solution containing the above electrolyte under conditions where hydrogen gas is generated. If the hydrogen gas bubbles are allowed to rise along the surface of the object to be treated, a silver-gray-white wood grain pattern will appear on the surface that presses in the hanging direction (vertical direction) of the object, so electrolysis should not be carried out at this stage. stop. Wood grain patterns appear due to electrolysis (1. During electrolytic treatment, many large and small hydrogen gas bubbles rise to the water surface from below while swaying slightly from side to side along the surface of the object to be treated. When this happens, there is a large difference in electrolyte between the part of the surface of the workpiece that has been traced by these bubbles and other parts, and the part where the bubbles have passed has a large difference in electrolyte level (more than other parts). This is thought to be due to the fact that many pores are formed on the surface, giving it a silvery grayish-white appearance.When the surface of the treated aluminum material is actually observed under a microscope, the areas traced by air bubbles (J) are considered to have a silvery-gray-white appearance. It has clearly changed to a depressed state. AC electrolytic treatment is followed by anodization treatment in an electrolyte containing an inorganic acid, an organic acid, or both of these, and an inorganic coloring bath or dye containing a metal. Alternatively, the process of coloring the surface of the object by immersing it in a pigment solution is not particularly different from the general method of forming a colored oxide film on (unpatterned) aluminum aluminum material, which involves the same processing means. There is also no need to use special acids, metal salts, dyes and pigments.

Note that if the object to be treated is lightly etched with an aqueous solution of sodium hydroxide prior to the anodizing treatment, a clearer colored pattern can be developed in the subsequent coloring treatment. When anodizing and coloring treatments are applied, the wood grain pattern, which was silvery-gray white before these treatments, is colored to a significantly sharper tone by the inorganic metal salts, dyes, or pigments in the coloring bath, and becomes the color to be treated. Appears on the surface of things.

This coloring treatment produces a colored wood grain pattern. This is thought to be due to the fact that coloring components such as dyes and pigments are deposited or adhered in a much larger amount than in other areas with a smaller pore distribution.In addition, according to the method of the present invention, a colored wood grain pattern can be developed at the same time. It can completely eliminate roll marks, scratches, bruises, dice marks, and streaks after anodizing that are found in ordinary processed aluminum materials.

As mentioned above, the method of the present invention uses a unique electrochemical treatment to naturally generate a wood grain pattern on the surface of the aluminum material, and the wood grain portion is clearly colored. There is no need to create an original drawing, and it is extremely simple and easy to express the pattern.

In addition, the method of the present invention does not require mechanical processing or manual labor unlike conventional methods, so productivity is extremely high. can be manufactured at extremely low cost.Furthermore, artificial patterns created by conventional methods such as stamping, etching, spraying or baking paint, and printing are inevitably unnatural because the same pattern is repeated. However, the wood grain pattern formed by the method of the present invention (no two pieces are the same and is very natural and close to the true grain of wood. Therefore, the surface treatment of the present invention The law prohibits aluminum sashes, health equipment, and panels for healthy buildings (
3rd item, single car, aluminum wood for household pottery decoration, etc.
When applied to the treatment of various aluminum materials, which are expected to improve product value by imparting a wood grain pattern, extremely remarkable effects can be achieved. The present invention will be explained below with reference to Examples. Example 1 An aluminum 6063S-T5 profile was pretreated by a conventional method and treated with tartaric acid 0.1 m01/l and sodium carbonate 5 g/l.
in a bath with an initial current density of 2.0 using a carbon plate as a counter electrode.
When alternating current was applied for 20 minutes at A/Dm2, a silvery gray-white wood grain pattern was formed on the surface of the profile.

The profile was then soaked in a sodium hydroxide solution (concentration 30g/1.
．． 60℃) for several minutes, and after washing with water, the concentration is 150g.
/11 Using a sulfuric acid bath at a temperature of 20°C, the current density was 1.2A/
Anodize at Dm2 for 30 minutes to coat the surface of the profile with approximately 10
A μ-thick anodic oxide film was formed. Next, the material was immersed in an inorganic coloring bath containing silver sulfate (temperature 6"O) for several minutes, and finally treated with boiling water, resulting in an aluminum womb material with a beautiful brown wood grain pattern. Example 2 Aluminum 1050P-Hl4 plate material was pretreated in a conventional manner in a bath of adipic acid 0.3 m01/11 phosphate triammonium 10 g/7 for 15 minutes at an initial current density of 3.0 A/Dm2 using a platinum plate as a counter electrode. When alternating current is applied,
A silver-gray white wood grain pattern was formed on the surface of the board.

Next, this shape was mixed with a sodium carbonate aqueous solution (concentration 50 g/1
After washing with water, an anodic oxide film having a thickness of about 10 μm was applied in the same manner as in Example 1 in a sulfuric acid bath.
After mixing, apply an inorganic coloring bath containing ferric ammonium oxalate (
When the aluminum board was immersed for several minutes in water (temperature: 60°C) and finally treated with boiling water, an aluminum wafer board with a pale yellow wood grain pattern was obtained. Example 3 An aluminum 6063S-T5 profile was pretreated by a conventional method, and 0.3 m of citric acid and 1 m of sodium hydroxide were added.
When alternating current is applied for 15 minutes at an initial current density of 2.0 A/Dm2 using a stainless steel plate as the counter electrode in a 0 g/l bath,
A silvery-gray white wood grain pattern was formed on the surface of the profile.

The profile was then soaked in sodium carbonate solution (40g/11 45
℃) for 2 minutes, and then anodized in a sulfuric acid bath to form an oxide film about 10μ thick on the surface of the shape. Next, this was immersed in an inorganic coloring bath (7 ``C'') containing stannous sulfate for several minutes, and finally a transparent resin coating was applied, resulting in a beautiful aluminum material with a dark color in the wood grain pattern. It was done. Example 4 An aluminum AlO5O-Hl4 plate material was pretreated by a conventional method, and when an alternating current was applied for 10 minutes at an initial current density of 2.0 AAm2 using a stainless steel plate as a counter electrode in a bath of 0.1 m01/l of sulfuric acid, the plate material A silvery-gray white grain pattern was formed on the surface.

Claims (1)

[Claims] 1 (a) Aluminum material is treated with sulfuric acid, phosphoric acid, chromic acid,
Sulfamic acid, tungstic acid, selenite, formic acid,
Acetic acid, propionic acid, butanoic acid, oxalic acid, succinic acid,
Adipic acid, maleic acid, malonic acid, lactic acid, malic acid,
A dilute aqueous solution of at least one acidic electrolyte selected from the group consisting of citric acid, tartaric acid, benzolsulfonic acid, phenolsulfonic acid, sulfosalicylic acid, cresolsulfonic acid, and thymolsulfonic acid, or sodium hydroxide and metasilicic acid in the aqueous solution. Any of the alkaline electrolytes of sodium, trisodium phosphate, sodium hydrogen carbonate, sodium metaborate, sodium sulfate, sodium carbonate, borax, sodium hydrogen sulfate, or their ammonium, calcium, lithium, barium, or potassium salts. Electrolytic treatment is carried out under conditions where hydrogen gas is generated on the surface of the aluminum material using an aqueous solution containing one type of aluminum, one or an aqueous solution with a similar effect as an electrolyte, using alternating current or a power waveform with a similar effect. (b) During the above electrolysis, the hydrogen gas bubbles generated on the surface of the workpiece are allowed to rise along the surface of the workpiece; (c) The action of the hydrogen gas bubbles causes the workpiece to rise. After carrying out the above electrolysis until a silver-gray white grain pattern is formed on the surface, the object to be treated is anodized in an electrolytic solution containing a non-functional, organic acid, or both; (d) metal salt; 1. A method for surface treatment of an aluminum material, comprising: immersing the object to be treated after the anodizing treatment in an inorganic coloring bath or a dye solution to which the above-mentioned anodizing treatment is added, thereby coloring the surface of the object to be treated.