JPH0841684A - Electrolytic pigmentation of anodic oxidation coating film of speeding-up of electrolytic pigmentation treatment - Google Patents

Abstract

PURPOSE:To provide a method capable of speeding-up same color tone coloring by enabling to use high voltage, in coloring an anodic oxidation coating film. CONSTITUTION:Aluminum or an aluminum alloy, on the surface of which the anodic oxidation coating film is formed, is electrolytically colored in a secondary electrolytic pigmenting solution prepared by adding a metallic salt into an acidic solution having 5-350g/l concn. As a result, the speeding-up of the same color tone coloring is enabled without damaging the anodic oxidation coating film even at the time of using high voltage and color tones to be obtained are increased with the increase of the width of the usable voltage and multi- coloring is attained by the electrolytic pigmentation method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electrolytically coloring an anodized film and a method for speeding up electrolytic coloring treatment.

[0002]

2. Description of the Related Art Conventionally, aluminum or aluminum alloy has been used in various fields such as ornaments, kitchen articles, optical equipment parts, name plates or building articles because of its characteristics. There is. Then, in order to be used for these purposes, various coloring treatments are usually applied. In recent years, there has been a growing demand for multiple colors in order to improve the quality and individuality of products, and therefore technical development of coloring treatment methods has been actively carried out.

The coloring treatment methods currently in use are roughly classified into the following methods. Method of adsorbing organic dye or inorganic compound to anodized film (dyeing method) Natural coloring method by anodizing treatment (electrolytic coloring method) Method of electrolytically coloring anodized film (electrolytic coloring method).

In the above dyeing method, since the organic dye or the inorganic compound is adsorbed in the fine pores of the anodic oxide film, the color can be freely selected, but there is a problem in weather resistance. Also, in the case of a large lot (mass production),
It also had the drawback of large color variations.

In the above-mentioned natural color development method, there is a problem that the synergistic effect of homogenizing the aluminum alloy composition and homogenizing the thickness of the anodized film obtained by anodizing treatment causes a large variation in color. However, there is also a problem that the color tone to be developed is limited depending on the alloy component. Furthermore, since special alloys and special solutions are used, there is a drawback that the cost is high.

Therefore, in the case of a large lot (mass production), the above-mentioned method, which has good weatherability of coloring and is inexpensive, that is, a method of electrolytically coloring (secondary electrolytic coloring) the anodic oxide film is adopted.

However, the conventional secondary electrolytic coloring method takes a relatively long processing time, and thus cannot be said to be a satisfactory method. If a high voltage (for example, 20 to 30 V) can be used during electrolytic coloring, it is possible to speed up (speed up) coloring with the same color tone, but if the voltage is increased, the anodic oxide film is destroyed. Therefore, it had to be used at a low voltage.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to make it possible to use a high voltage in the coloring treatment of an anodized film so that the same color tone can be obtained. It is intended to provide a method that enables speeding up (speeding up).

[0009]

In the electrolytic coloring method for an anodized film of the present invention, aluminum or aluminum alloy having an anodized film formed on its surface is electrolytically colored in a secondary electrolytic coloring solution. In the method, the secondary electrolytic coloring solution contains 5 to 3 acidic compounds per liter.
The method is characterized by including 50 g.

The method according to claim 2 is the method according to claim 1, wherein the acid concentration of the secondary electrolytic coloring solution is 18
It is characterized in that it is 0 to 350 g / liter.

The method according to claim 3 is a method for accelerating the electrolytic coloring treatment in which an anodized film formed on the surface of aluminum or an aluminum alloy is colored in a secondary electrolytic coloring solution. Is 5 per liter
The method is characterized by using an acidic solution containing ~ 350 g as a secondary electrolytic coloring solution.

As the electrolytic coloring solution in the present invention, a solution obtained by adding a metal salt to a solution of the above acidic compound is usually used.

The acidic compounds that can be used in the present invention include
Examples thereof include inorganic acids such as sulfuric acid, phosphoric acid, chromic acid and nitric acid, or organic acids such as oxalic acid, formic acid, sulfosalicylic acid and sulfamic acid, and mixed solutions of the above inorganic acids and organic acids, but are not limited thereto. is not.

As the metal salt, nickel, cobalt,
Mention may be made of sulfates, nitrates, carbonates, acetates etc. of tin, zinc, copper or manganese etc. or mixtures of these salts.

The concentration of the acidic compound (inorganic acid and / or organic acid) contained in the coloring solution is higher than that of the conventional one.
~ 350 g / l. The concentration of the acid compound is 5
When it is less than g / liter, there is a problem that the anodic oxide film is destroyed due to the use of high voltage.
When it exceeds 50 g / liter, there arises a problem that the uniformity of coloring becomes poor due to occurrence of color loss, color shark and the like. The concentration of 50 to 350 g / liter is preferable, the concentration of 100 to 350 g / liter is more preferable, and the concentration of 180 to 350 g / liter is further preferable, because the oxide film can be stably colored even when using a high voltage. .

The concentration of the metal salt in the coloring solution varies depending on the metal salt used and cannot be generally stated, but it is usually 1 to 200 g per liter of the coloring solution. When the concentration of the metal salt is less than 1 g / liter, there is a tendency that coloring of the anodic oxide coating is not observed, and when it exceeds 200 g / liter, abnormalities of the added metal on the surface of the anodic oxide coating occur. Precipitation is likely to occur.

As described above, electrolytic coloring is performed by using an acidic metal salt solution prepared by adding a metal salt to a solution of an inorganic acid or an organic acid having a high concentration of 5 to 350 g / liter or a mixture thereof as a coloring solution. If done, the conventional 2
Coloring with high voltage, which could not be used with secondary electrolytic coloring, is possible (that is, coloring can be done without destroying the anodic oxide film even when a high voltage is used), thereby speeding up the same-tone coloring (speeding up). Will be realized.

As another effect of the present invention, "multicoloring"
Can be mentioned. Although it is possible to perform multicolor treatment by an electrolytic coloring method at a voltage level (8 to 20 V) that is normally used, this includes an intermediate treatment (third electrolysis) during anodized film formation and anodization treatment. It involved complicated processing steps such as control at the power source (use of a special power source). However, according to the present invention, it is possible to easily obtain a multi-colored color tone in the same range as that obtained by the above-mentioned tertiary electrolysis or the like.

That is, by increasing the concentration of the coloring solution used to the above-mentioned level, the voltage used during electrolytic coloring can be selected within the range of 8 to 30V, for example. The color of the anodized film is determined by the value of the voltage, but as described above, the range of voltage values that can be used is as wide as 30 V, so that the color tone obtained increases accordingly.

According to the present invention, a uniform and even coating such as gray, blue, yellow, green, purple, bronze, and black can be easily formed on the secondary electrolytically colored product, and the quality is the same as the conventional product. It is available in.

[0021]

EFFECTS OF THE INVENTION According to the present invention, when the anodized film is colored, the anodized film is not destroyed even if a high voltage is used, and the coloring with the same color can be speeded up (speeded up). Also, because the range of voltage values that can be used has become wider,
As a result, more colors can be obtained, and multicoloring in the electrolytic coloring method has been realized.

[0022]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to this.

Example 1 A5052P-H32 aluminum plate (70 mm × 1)
(50 mm × 1.5 mm) was immersed in a 10% nitric acid aqueous solution for 10 minutes at room temperature and then washed with water in order to remove oil and oxide film from the surface.

Next, it was immersed in a 5% aqueous solution of caustic soda heated to 50 ° C. for 3 minutes, washed with water, immersed in a 10% aqueous solution of nitric acid at room temperature for 5 minutes to be neutralized, and then washed with water.

After the surface of the aluminum plate was washed by the above pretreatment process, a carbon plate was used as a cathode at a liquid temperature of 20 ° C. in a 15% sulfuric acid aqueous solution, and a direct current having a current density of 1.0 A / dm ² was used for 30 times. Anodize for minutes and rinse with water for 9
An anodized film having a thickness of μm was obtained.

The anodic oxide film thus obtained was treated with sulfuric acid 200 g / liter and tin sulfate 10 g / liter (concentration 2
10 g per liter of a sulfuric acid solution of 00 g / liter
Means that it contains tin sulfate. The same applies below. ) Was immersed in the secondary electrolytic coloring solution, and a carbon plate was used as a cathode to carry out electrolytic coloring at an AC voltage of 10 V for 3 minutes.

The secondary electrolytic coloring film thus obtained was colored in a uniform light bronze color throughout.

Example 2 The same procedure as in Example 1 was carried out except that the AC voltage during electrolytic coloring was increased from 10 V to 28 V, and the same color tone as that obtained in Example 1 (light bronze color) was obtained. And electrolytically colored.

As a result, during the treatment, the electrolytic coloring treatment for 30 seconds causes the entire secondary electrolytic coloring film to be colored in a uniform light bronze color without causing the destruction of the anodic oxide coating, which accelerates the processing time (high speed). Was significantly observed.

Example 3 Electrolytic coloring was carried out in the same manner as in Example 1 (electrolytic coloring time was also 3 minutes) except that the alternating voltage during electrolytic coloring was changed from 10V to 28V.

As a result, the anodic oxide coating was not destroyed, and the entire anodic oxide coating was colored uniformly gray.

Example 4 A1200P-H24 aluminum plate (70 mm × 1)
50 mm × 1.5 mm) was pretreated and anodized in the same manner as in Example 1 to obtain an anodized film of 9 μm.

The anodic oxide film thus obtained is dipped in a secondary electrolytic coloring solution of 300 g / liter of sulfuric acid / 30 g / liter of nickel sulfate, and electrolytic coloring is carried out for 3 minutes at an alternating voltage of 12 V using a carbon plate as a cathode. I went.

The secondary electrolytically colored film thus obtained was uniformly colored in bronze.

Example 5 The same procedure as in Example 4 was carried out except that the AC voltage during electrolytic coloring was increased from 12 V to 28 V, and the same color tone as that obtained in Example 4 (bronze color) was obtained. Electrolytic coloring treatment was performed.

As a result, during the treatment, the electrolytic coloring treatment for 30 seconds causes the entire secondary electrolytic coloring film to be colored in a uniform bronze color without causing destruction of the anodic oxide coating, which accelerates the treatment time (speeds up). ) Was noticeable.

Example 6 Electrolytic coloring was carried out in the same manner as in Example 4 (the electrolytic coloring time was also 3 minutes) except that the alternating voltage during electrolytic coloring was changed from 12V to 28V.

As a result, the anodic oxide coating was not destroyed and the entire anodic oxide coating was colored in a uniform yellow-green color.

Example 7 Aluminum plate of A5005P-H32 (70 mm × 1)
50 mm × 1.5 mm) was pretreated and anodized in the same manner as in Example 1 to obtain an anodized film having a thickness of 9 μm.

The anodic oxide film thus obtained was treated with 100 g of sulfamic acid / liter / 50 g of cobalt sulfate /
It was immersed in 1 liter of the secondary electrolytic coloring solution, and a carbon plate was used as the cathode to carry out electrolytic coloring at an AC voltage of 15 V for 3 minutes.

The thus-obtained secondary electrolytic coloring film was uniformly brown in color.

Example 8 The same procedure as in Example 7 was carried out except that the AC voltage at the time of electrolytic coloring was increased from 15 V to 30 V, and electrolysis was performed to obtain the same color tone (brown) as that obtained in Example 7. Coloring treatment was performed.

As a result, during the treatment, the secondary electrolytic coloring film is uniformly browned by the electrolytic coloring treatment for 30 seconds without causing destruction of the anodized film, and the processing time is accelerated (acceleration). Was noticeable.

Example 9 Electrolytic coloring was performed in the same manner as in Example 7 except that the AC voltage during electrolytic coloring was changed from 15V to 30V.

As a result, the anodic oxide film was not destroyed, and the entire anodic oxide film was uniformly dark purple colored.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taichi Hasegawa 2-7-26, 2-chome, Hotaruikenishicho, Toyonaka-shi, Osaka N ACL Building, 2nd floor, Nippon Electric Chemical Co., Ltd.

Claims (3)

[Claims] 1. A method of electrolytically coloring aluminum or an aluminum alloy having an anodized film formed on the surface thereof in a secondary electrolytic coloring solution, wherein the secondary electrolytic coloring solution contains 5 acidic compounds per liter. The method for electrolytically coloring an anodized film is characterized by containing ˜350 g. 2. The method for electrolytically coloring an anodized film according to claim 1, wherein a solution containing 180 to 350 g of an acidic compound per liter is used as the secondary electrolytic coloring solution. 3. A method for accelerating electrolytic coloring treatment for coloring an anodized film formed on the surface of aluminum or an aluminum alloy in a secondary electrolytic coloring solution, wherein the acidic compound is 5 to 350 g per liter. A method for accelerating electrolytic coloring treatment, which comprises using the contained acidic solution as a secondary electrolytic coloring solution.