JPS6133919B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method for producing various colored patterns on the surface of aluminum.

The present invention relates to a surface treatment method for creating patterns on the surface of aluminum.

Currently, several surface treatment technologies have been published that create patterns on the surface of aluminum, but in all of them, the patterns that appear after coloring are either patterns created by the shading of the hue due to the coloring, or patterns that are created by the coloring of the colored parts. Since the pattern is created by the formation of colored and non-colored areas, the patterned area and the non-patterned area do not appear as a difference in hue itself, and the surface appearance tends to have little change and give a monotonous impression.

Therefore, the present invention creates patterns based on differences in hue that cannot be obtained with conventional surface treatment methods.
It makes it possible to make various changes to the surface appearance of aluminum, increasing the utility value of aluminum,
With the aim of expanding the range of uses for patterned products, this unique ingenuity has been applied to the surface treatment method for aluminum.

That is, in the method of the present invention, aluminum on which an anodic oxide film has been formed is subjected to an intermediate treatment consisting of a step of creating a pattern and an electrolytic treatment step of changing the micropores of the anodic oxide film, and then the aluminum is treated. It is characterized by being colored.

In this specification, "aluminum" is a general term for aluminum and aluminum alloys.

The method of the present invention will be described in detail below. First, aluminum is subjected to commonly known pretreatments such as degreasing, etching, and smut removal. An anodic oxide film is produced on the surface by electrolytic treatment using direct current, AC/DC superimposition, or a current waveform having an equivalent effect in various treatment baths capable of producing an acidic film.

Prior to coloring this anodic oxide film,
An important point of the present invention is to perform an intermediate treatment, and by this intermediate treatment, a pattern is created on the surface of the aluminum, and by coloring treatment, the patterned part and the non-patterned part have different hues.
The intermediate treatment according to the present invention can be roughly divided into the following two aspects, which causes a structural difference between the micropores of the anodic oxide film in the patterned part and the micropores of the anodic oxide film in the non-patterned part.

(1) Intermediate treatment that is performed in the following order: a step of applying a pattern to the aluminum on which the anodic oxide film has been formed, and then a step of changing the micropore structure of the anodic oxide film.

(2) An intermediate treatment that is performed in the following order: an electrolytic treatment process that changes the micropore structure of the anodic oxide film, and then a process that generates a pattern.

First, to explain the first intermediate processing in detail, the following methods can be cited as processing methods for pattern generation in this case.

(a) One or two of acids, their salts, or bases
A method of electrolytic treatment in an aqueous solution containing more than one species.

Specifically, a bath containing one or more of inorganic acids such as sulfuric acid, phosphoric acid, boric acid, hydrochloric acid, chromic acid, pyrophosphoric acid, phosphomolybdic acid, and sulfamic acid or their salts, or an inorganic acid and A bath using an aqueous solution containing a mixture of inorganic acid salts, or a bath containing one or more of organic acids such as sulfosalicylic acid, succinic acid, oxalic acid, phthalic acid, malonic acid, malic acid, or their salts, or an organic acid. Electrolytic treatment is carried out using a bath containing a mixture of organic acid salts and organic acid salts, and using alternating current or a similar waveform that changes between positive and negative polarities. A bath containing one or more bases is used, and the above-mentioned inorganic acids, inorganic acid salts, organic acids, organic acid salts, and bases may be mixed as appropriate.

When this patterning process is performed, a large amount of hydrogen gas is generated on the surface of the aluminum and rises, but this rising hydrogen gas may lightly scratch off the anodic oxide film or partially scratch the anodic oxide film. By eliminating the
A pattern corresponding to the upward trajectory of the hydrogen gas is generated, and a difference in the thickness of the anodic oxide film occurs between the patterned portion and the non-patterned portion.

(b) A method in which an aqueous solution containing one or more of inorganic acids, organic acids, or their salts or bases is brought into local contact with the surface of aluminum and then energized.

This method creates a partial barrier type film or growth type film corresponding to the pattern on the anodic oxide film of aluminum, and the characteristics or film thickness of the anodic oxide film differ between the patterned area and the non-patterned area. The aim is to add the following, and it is implemented by the means exemplified below.

That is, a sponge or brush impregnated with the above aqueous solution is placed on the surface of the aluminum or is run on it. Alternatively, a patterned roller is coated with an aqueous solution in the form of a paste and impregnated, and then adhered to the aluminum surface as in letterpress printing.

Current conditions include using an alternating current between a sponge or the like impregnated with an aqueous solution and aluminum, or using a similar waveform that changes between positive and negative polarity, or connecting the above sponge to the cathode and aluminum to the anode. It is conceivable to perform direct current electrolysis.

(c) A method in which steam is partially sprayed onto the surface of aluminum on which an anodized film has been formed.

As a result, the anodic oxide film is partially sealed, so that the effect of electrolytic treatment in the next step in an aqueous acid solution differs between the unsealed part and the unsealed part.

(d) A method that uses masking materials such as paint, resin, oil, or tape to partially cover the aluminum surface.

This method prevents the electrolytic treatment effect of the next step from reaching the anodic oxide film of the covered portion.

Furthermore, the method using this masking material and the method using a roller in (b) above can also be combined.

(E) In addition to the above method, a method of partially contacting the surface of aluminum with a pattern generation treatment solution using means such as spraying.

This takes advantage of the fact that the solution that comes into contact with the aluminum surface inhibits or promotes the electrolytic treatment in the next step, creating a difference in the effect of the electrolytic treatment between the contact area and the non-contact area. .

By using the various methods described above, line patterns, wood grain patterns, wavy patterns, and other various designs can be generated on the surface of aluminum.

In the first intermediate processing according to the present invention,
After going through the treatment process to create patterns in this way, aluminum is electrolytically treated in an aqueous solution of a specific acid or its salt, but this electrolytic treatment process cannot be obtained by conventional coloring treatment methods. This is an indispensable and important process in order to obtain the desired hue, and it adds structural changes to the micropores of the anodic oxide film.

That is, if aluminum with an anodic oxide film formed thereon is simply electrolytically treated without undergoing any treatment to create the pattern, a uniform structural change will be made to the micropores throughout the anodic oxide film. The color-treated aluminum surface has a uniform hue throughout (of course, the hue in this case cannot be obtained by conventional coloring treatments), and the intended purpose cannot be achieved.

However, in the method of the present invention, since the anodic oxide film is treated to form a pattern, there is a difference in the effect of the electrolytic treatment between the patterned area and the non-patterned area. That is, when the masking material is coated on the anodic oxide film in the process for generating the pattern, the electrolytic treatment effect does not reach the coated area at all, and only the uncoated area is electrolytically treated. Therefore, structural changes are made only to the fine pores of the anodic oxide film in the uncovered portions. Therefore, between the patterned part and the non-patterned part,
There will be a difference in the structure of the micropores, and a corresponding difference will occur in the coloring effect of the next coloring process, resulting in different hues between the patterned and non-patterned areas.

Furthermore, if a process is performed to create a pattern other than the above masking material, the characteristics of the anodized film may differ between the patterned area and the non-patterned area, or the film thickness may differ. As a result, the structural changes made to the fine pores of the anodic oxide film are not uniform, resulting in differences in the structure of the fine pores between the patterned and non-patterned areas.

The acids used to change the micropores of the anodized film include phosphoric acid, chromic acid, pyrophosphoric acid,
Inorganic acids such as phosphorous acid and sulfamic acid or their salts, and it is also possible to use sulfuric acid with a high concentration of 40V/V%, and furthermore, malonic acid, maleic acid, malic acid, gluconic acid, etc. , guric acid, tartaric acid, cresolsulfonic acid, phenolsulfonic acid, sulfosalicylic acid, sulfophthalic acid, gallic acid, benzoic acid, phthalic acid, carbolic acid, etc.
Organic acids containing COOH groups and -OH groups, or salts thereof are also suitable for use, and these inorganic acids, inorganic acid salts, organic acids, or organic acid salts may be used in appropriate mixtures.

There are no particular restrictions on the electrolytic conditions, and any electrolytic treatment can be adopted as appropriate, such as direct current electrolysis with aluminum connected to the anode, alternating current electrolysis, AC/DC superimposed electrolysis, or electrolytic treatment using a current waveform that has an equivalent effect. It may be sufficient to cause a structural change in the fine pores of the anodic oxide film, and this relatively changes depending on the concentration and temperature of the bath.

Further, although there is no restriction on the processing time, the structure of the micropores changes variously depending on the time change, and the coloring effect can also be changed accordingly.

Furthermore, in the present invention, an intermediate treatment can be carried out by reversing the order of the treatment step for producing the above pattern and the electrolytic treatment step for changing the micropore structure of the anodic oxide film. That is, by electrolytically treating aluminum on which an anodic oxide film has been formed in an aqueous solution of a specific acid or its salt, a uniform structural change is applied to the micropores throughout the anodic oxide film, and then a pattern is formed on the aluminum. The process is performed to generate the . The electrolytic treatment method and the treatment method for generating the pattern here are the same as the various treatment methods related to the first aspect described above, and therefore, by performing the treatment for generating the pattern, The anodic oxide film, which has undergone structural changes to the micropores, is differentially excavated, a further film is formed partially, or the pores are partially sealed.
Furthermore, it partially changes the properties of the anodized film, resulting in differences in the properties or micropore structure of the anodic oxide film between patterned and non-patterned areas, resulting in a difference in the coloring process in the next step. This makes a difference in the coloring effect.

After passing through an intermediate treatment consisting of a treatment step to create such a pattern and an electrolytic treatment step to change the structure of the anodic oxide film, a coloring treatment is applied. Method of coloring by dipping in nickel,
AC electrolysis is performed in a coloring bath containing acids or salts of various metals involved in coloring, such as cobalt, copper, tin, iron, zinc, manganese, chromium, and molybdenum, or aluminum is connected to the cathode in the coloring bath. Examples of known coloring treatment methods include direct current electrolysis.

These coloring treatments cause dyes, pigments, metals, or metal compounds to precipitate into the micropores of the anodic oxide film, but as mentioned above, the micropore structure of the anodic oxide film is separated between the patterned and non-patterned areas. Because there are differences in the changes, or there are differences in the properties of the anodic oxide film, there are differences in the precipitation of dyes, pigments, metals, or metal compounds, resulting in differences between patterned areas and non-patterned areas. The parts exhibit different hues, and a colored pattern can be generated based on the difference in hue.

Examples of the method of the present invention will be described below.

[Example 1] Aluminum alloy A6063S was immersed in a bath containing 5 Wt% nitric acid at 20°C for 5 minutes, degreased and cleaned, and then immersed in a bath containing 5 Wt% sodium hydroxide at 50°C for 8 minutes. , etched and treated with nitric acid.
The smut was removed by immersing it in a 10Wt% solution at 20°C. Next, after anodizing for 30 minutes under the conditions of 150 g of sulfuric acid, bath temperature of 20°C, and electrical density of 1.0 A/ ^dm2 , a sponge impregnated with an aqueous solution of 100 g of phosphorous acid was brought into contact with the aluminum alloy surface. Connect the alloy to the anode and the sponge to the cathode, and perform electrolytic treatment for patterning at 20 volts DC for 5 minutes.

After that, in a bath of 100 g of phosphorous acid, the bath temperature was 20
Anodic electrolytic treatment was performed for 8 minutes at ℃ and 25 volts DC to cause structural changes in the micropores of the anodic oxide film. This aluminum alloy was mixed with 10g of stannous sulfate/
, in a solution of 10 g of sulfuric acid at 12 volts AC.
When electrolyzed for one minute, a patterned colored film was formed in which the parts in contact with the sponge were colored stainless steel and the other parts were colored yellow.

[Example 2] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then treated with 150 g of sulfuric acid and a bath temperature of 20
Anodizing was performed for 30 minutes at a temperature of 1.0 A/dm ² . Next, a brush impregnated with a solution of 150 g of sulfuric acid is connected to the cathode, the aluminum alloy is connected to the anode, and characters are drawn on the surface of the aluminum alloy with the brush while applying a voltage of 26 volts DC.
After that, this aluminum alloy was treated with chromic acid.
In a solution containing 75 g of ammonium sulfate and 30 g of ammonium sulfate, it was connected to an anode and subjected to electrolytic treatment for 5 minutes at a bath temperature of 35° C. and a DC of 60 volts to cause structural changes in the micropores of the anodic oxide film. Then, this aluminum alloy was mixed with 10g of manganese sulfate and hydrogen peroxide solution.
When electrolytically colored for 5 minutes in a 10 ml bath at 60 volts AC, a patterned film was formed in which the text was golden yellow and the other parts dark brown.

[Example 3] After subjecting an aluminum plate A1200P to the same pretreatment as in Example 1, sulfuric acid 150g/bath temperature 20℃,
Anodic oxidation treatment was performed for 30 minutes at an electric density of 1.0 A/dm ² . A portion of the aluminum plate was then blasted with steam for 5 minutes to partially change the properties of the anodized film. Next, this aluminum plate was electrolytically treated in a bath containing 50 g of malonic acid and 50 g of sulfamic acid at a bath temperature of 35°C and an AC of 40 volts for 8 minutes to change the micropore structure of the anodic oxide film. When electrolytically colored in a bath containing 30 g of cobalt sulfate and 40 g of boric acid at a bath temperature of 20°C and AC 25 volts for 40 seconds, the areas sprayed with steam were colored grayish-purple, and the other areas colored grayish-blue. A patterned film was formed.

[Example 4] After subjecting aluminum alloy A6063S to the same pretreatment as in Example 1, sulfuric acid 150g/bath temperature 20
Anodizing was performed for 30 minutes at a temperature of 1.0 A/dm ² . Masking tape was then attached to a part of the aluminum alloy, and in this state it was immersed in water at 95°C for 3 minutes to change the properties of the anodic oxide film. After that, remove the masking tape and use oxalic acid.
In an aqueous solution of 5g/, phosphoric acid 200g/, bath temperature 25
Electrolytic treatment was performed for 3 minutes at ℃ and 20 volts AC to cause structural changes in the micropores of the anodic oxide film. Next, this aluminum alloy is treated with nickel sulfate.
When electrolyzed for 2 minutes at 16 volts AC in an aqueous solution of 30 g/boric acid and 30 g/boric acid, a patterned film colored pale bronze and blue was produced.

[Example 5] After subjecting aluminum alloy A6063S to the same pretreatment as in Example 1, sulfuric acid 150g/, bath temperature 20
Anodizing was performed for 30 minutes at a temperature of 1.0 A/dm ² . Then, while overlaying the paper pattern for pattern generation on the aluminum alloy surface, a paste of 50 g of boric acid and 30 g of citric acid was applied to a roller connected to the cathode, and the roller was moved over the aluminum surface while applying a voltage of 22 volts DC. The micropore structure of the anodic oxide film was partially changed by electrolytic printing while running the film. Next, this aluminum alloy was placed in a bath containing 150 g of phosphorous acid and 50 g of sodium dihydrogen phosphate at a bath temperature of 25°C.
After electrolytic treatment under the conditions of AC28 volts, in a bath containing 10 g of stannous sulfate and 10 g of sulfuric acid, at a bath temperature of 20 volts.
When electrolytically colored for 2 minutes and 30 seconds at ℃ and AC 13 volts, a colored film with yellow and yellow-green patterns was formed.

[Example 6] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then treated with 150 g of sulfuric acid and a bath temperature of 20
Anodization treatment was performed for 30 minutes at a temperature of 1.0 A/dm ² . Then, while overlaying the pattern paper on the aluminum alloy surface, a paste containing 10 g of ammonium borate was applied to a roller connected to the cathode, and a DC voltage of 0 to 30 volts was swept at a speed of 1 V/sec, and the roller was moved for 1 cm. By performing electrolytic printing while moving at a speed of /sec, the micropore structure of the anodic oxide film was partially changed.
Next, this aluminum alloy was mixed with gluconic acid.
100g/, maleic acid 10g/ in an aqueous solution at bath temperature
After electrolytic treatment at 20°C/35 volts AC, electrolytic coloring was performed for 1 minute in a bath containing 10 g/sulfuric acid/10 g/sulfuric acid at a bath temperature of 20°C and 15 volts AC. Depending on the conditions, a multicolored patterned film of stainless steel color, grayish-blue-purple, blue-green, and pink was formed.

[Example 7] After pre-treating an aluminum plate A1200P in the same manner as in Example 1, sulfuric acid 150g/bath temperature 20
Anodizing was carried out for 30 minutes at a temperature of 1.0 A/dm ² . Next, phosphoric acid was applied to this aluminum plate.
After partially contacting 100g/ for 5 minutes to partially change the properties of the anodized film, phosphoric acid
It was connected to the anode in a 100 g bath and electrolytically treated for 4 minutes at DC 18 volts and bath temperature 20°C. Next, this aluminum plate was treated with 30g of nickel sulfate/
When electrolytically colored for 2 minutes in a bath containing 30 g of boric acid at a bath temperature of 20° C. and a DC of 20 volts, a patterned film was formed in which the areas in contact with the phosphoric acid were colored bluish-purple and the rest were colored yellowish bronze.

[Example 8] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then subjected to anodization treatment for 30 minutes under the conditions of 150 g/20° C. and 1.0 A/dm ² in bath temperature. Sodium hydroxide on this aluminum alloy
A 0.1 Wt% aqueous solution was sprayed to partially change the properties of the anodic oxide film. Thereafter, it was connected to an anode in an aqueous solution containing 50 g of malonic acid and 50 g of chromic acid, and electrolyzed for 5 minutes at a bath temperature of 25° C. and a DC of 35 volts. Next, this aluminum alloy was mixed with 10 g of stannous sulfate and 10 g of sulfuric acid.
When electrolytically colored in an aqueous solution of 20° C. and AC 14 volts for 7 minutes, a colored film with a dark reddish-brown pattern of ocher spots was formed.

[Example 9] After subjecting aluminum alloy A6063S to the same pretreatment as in Example 1, sulfuric acid 100g/, boric acid 30g/
Anodizing was performed for 30 minutes at a bath temperature of 20° C. and an electric density of 1.0 A/dm ² . And chromic acid
The properties of the anodic oxide film were partially changed by bringing the aluminum alloy into contact with a foamed solution prepared by adding an activator to a 100 g aqueous solution and leaving it for 10 minutes.

Next, the aluminum alloy was connected to the anode in an aqueous solution of 100 g of chromic acid, and the bath temperature was 15°C.
C. After electrolytic treatment for 10 minutes at 40 volts, this aluminum alloy was electrolytically colored in a bath containing 10 g of copper sulfate and 10 ml of hydrogen peroxide for 3 minutes at a bath temperature of 25°C and 60 volts AC. A colored film with a yellow hexagonal pattern was formed on the green surface.

[Example 10] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then an AC film was formed under the conditions of 15 Wt% sulfuric acid, bath temperature of 20° C., and electrical density of 2.0 A/dm ² . And ammonium sulfate 5g/, phosphoric acid 200g/
An operation was repeated 10 times in which a sponge impregnated with an aqueous solution was brought into partial contact with the aluminum alloy, and the sponge was moved at a speed of 1 cm/sec while applying a voltage of 25 volts AC. Then,
The micropore structure of the anodic oxide film was changed by electrolytically treating this aluminum alloy in a bath containing 50 g of tartaric acid and 30 g of malic acid at a bath temperature of 20° C. and an AC of 18 volts for 5 minutes. After that, after immersing it in a bath containing 6.5 g of cobalt acetate at a pH of 6.8 and a bath temperature of 45 degrees Celsius, the sealing process with pure water was performed for 30 minutes. A colored, patterned film was formed.

[Example 11] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then anodized for 30 minutes under the conditions of 150 g of sulfuric acid, 30 g of ammonium sulfate, bath temperature of 20°C, and electric density of 1.0 A/ ^dm2. Processed. Then, 1g/g of potassium hydroxide was applied to the surface of this aluminum alloy.
The anodic oxide film is dried by spraying it with an aqueous solution that partially changes the properties of the anodized film.
Next, this aluminum alloy was placed in an aqueous solution containing 100 g of ammonium phosphate at a bath temperature of 20°C and a DC of 25°C.
After electrolyzing for 5 minutes under the conditions of volts, connect to the cathode in a bath of 10 g of manganese sulfate and 10 ml of hydrogen peroxide, electrolyze for 1 minute at a bath temperature of 20°C and 30 volts, and the spray will be applied. A patterned colored film was formed, with some parts being gold-colored and other parts being brick-colored.

[Example 12] Aluminum alloy A6063S was degreased by immersing it in a bath containing 5 Wt% nitric acid and a bath temperature of 20°C for 5 minutes, and then etching by immersing it in a bath containing 5 Wt% sodium hydroxide at a temperature of 50°C for 8 minutes. Treated with nitric acid 10Wt
%, smut was removed by immersing it in a bath at 20°C. Next, sulfuric acid 150g/, bath temperature 20℃, electric density
The aluminum alloy that had been anodized for 30 minutes at 1.0 A/dm ² to form an anodized film was connected to the anode in a bath containing 150 g of phosphorous acid and 50 g of citric acid. The micropore structure of the anodic oxide film was uniformly changed by electrolytic treatment at 20°C and 20 volts DC for 3 minutes. and,
A roller impregnated with 30 g of boric acid paste is connected to the cathode, an aluminum alloy is connected to the anode, a paper pattern for pattern generation is interposed between the two, and the roller is moved 1 cm/1 cm while applying a voltage of 25 volts DC. By moving at a speed of sec,
The characteristics of the anodic oxide film were partially changed according to the pattern. This aluminum alloy was then treated with sulfuric acid.
In an aqueous solution of tin 10g/, sulfuric acid 10g/, bath temperature 20
When electrolytically colored for 30 seconds at ℃ and 25 volts AC, a colored film with a pattern was formed, with the roller contact area being yellow and the other areas being reddish-purple.

[Example 13] After subjecting aluminum alloy A6063S to the same pretreatment as in Example 1, sulfuric acid 150g/, bath temperature 20
Anodizing was carried out for 30 minutes at a temperature of 1.0 g/dm ² . This aluminum alloy was electrolytically treated in a bath containing 100 g of chromic acid at a bath temperature of 20° C. and AC of 30 volts for 5 minutes to change the micropore structure of the anodic oxide film. Next, an aqueous solution containing 50 g of sodium sulfate was sprayed onto the surface of this aluminum alloy, and after drying the anodized film with its properties partially changed, an aqueous solution containing 30 g of nickel sulfate and 40 g of boric acid was sprayed onto the surface of the aluminum alloy. Inside, the aluminum alloy was connected to the cathode, and the bath temperature was 20℃.
When electrolytically colored for 20 seconds at 16 volts DC, a pale blue patterned colored film with gray-purple spots was formed on the aluminum alloy surface.

[Example 14] After degreasing and cleaning aluminum plate A1100P with methyl ethyl ketone, sulfuric acid 150 g/bath temperature 20°C
Anodic oxidation treatment was performed for 30 minutes at an electric density of 1.0 A/dm ² . The micropore structure of the anodic oxide film was changed by electrolytic treatment in an aqueous solution containing 100 g of malic acid at a bath temperature of 20°C and AC of 35 volts for 10 minutes. Next, on this aluminum plate,
A sponge impregnated with 100 g of sulfuric acid is brought into contact with the aluminum plate as an anode, and electrolytic treatment is performed at 20 volts DC for 5 minutes to partially form an anodized film, and then cobalt sulfate is applied.
When electrolytically colored for 2 minutes in a 30 g bath at a bath temperature of 20°C and an AC of 20 volts, a patterned colored film was formed in which the area in contact with the sponge was yellow-green and the other areas were bronze.

[Example 15] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then treated with sulfuric acid 150 g/bath temperature 20
Anodizing was carried out for 30 minutes at a temperature of 1.0 A/dm ² . and cresol sulfonic acid
The micropore structure of the anodic oxide film was changed by electrolytic treatment for 7 minutes in a solution of 80 g/sulfosalicylic acid and 55 g/sulfosalicylic acid at a bath temperature of 20°C and AC 18 volts, and then partially treated with steam for 2 minutes. A pore sealing treatment was performed. Next, this aluminum alloy was electrolytically colored in a bath containing 10 g of tinned sulfate and 10 g of sulfuric acid at a bath temperature of 20°C and an AC of 16 volts for 5 minutes. A colored film with a black pattern was formed.

[Example 16] After pre-treating an aluminum plate A1100P in the same manner as in Example 1, sulfuric acid 150g/, bath temperature 20
Anodic oxidation treatment was performed for 30 minutes at a temperature of 1.0 A/dm ² at an electric density of 1.0 A/dm 2 . Then, the micropore structure of the anodic oxide film was changed by connecting it to an anode in a bath containing 100 g of phosphoric acid and performing electrolytic treatment for 7 minutes at a bath temperature of 25° C. and a DC of 25 volts. Next, a flow pattern was formed on the surface of the aluminum plate by spraying with a solution containing 5 g of potassium hydroxide and silicone oil, and then the aluminum plate was placed in a bath of 30 g of potassium permanganate. When electrolytically colored for 5 minutes at a bath temperature of 20°C and an AC voltage of 15 volts, a gray-brown patterned colored film with a yellow mottled pattern was formed.

[Example 17] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, then sulfuric acid 100g/, sodium sulfate 100g/, bath temperature 20°C, electric density 1.0A/dm ²
Anodization treatment was performed for 30 minutes under the following conditions. Then, this aluminum alloy was mixed with 100g of sulfamic acid/
The micropore structure of the anodized film was changed by electrolytic treatment for 10 minutes in a bath containing 10 g of sulfuric acid at a bath temperature of 25°C and AC of 25 volts. Next, oil and fat were partially attached to the surface of the dried aluminum alloy and immersed in pure water at 100°C for 3 minutes to change the properties of the anodic oxide film other than the areas where the oil and fat were attached. After that, this aluminum alloy was mixed with 10 g of manganese sulfate and 10 g of hydrogen peroxide solution.
Connect to the cathode in an aqueous solution of ml/ml, bath temperature 20℃,
When electrolytically colored for 2 minutes at 45 volts DC, a patterned colored film was formed in which the areas where the oil was attached were light golden yellow and the other areas were reddish ocher.

[Example 18] After subjecting aluminum alloy A6063S to the same pretreatment as in Example 1, it was treated with a sulfuric acid oxalic acid mixed acid, a bath temperature of 20°C,
Anodic oxidation treatment was performed for 30 minutes at an electric density of 1.0 A/dm ² . Then, the micropore structure of the anodized film was changed by electrolytic treatment for 7 minutes in a bath containing 100 g of phosphorous acid at a bath temperature of 20° C. and an AC voltage of 10 volts. Part of this aluminum alloy was covered with masking tape, and 10 g of sulfuric acid was added.
In a solution of ammonium sulfate 50g/bath temperature 20
By performing electrolytic treatment for 2 minutes at 12 volts AC, a portion where an anodic oxide film was further grown and a portion where it was not were obtained. Next, after removing the masking tape, electrolytic coloring was performed for 60 seconds in a bath containing 30 g of nickel sulfate and 30 g of boric acid at a bath temperature of 20°C and an AC of 12 volts.The masked area on the aluminum alloy surface turned grayish-purple. A colored film with a yellow-green pattern was formed in other parts.

[Example 19] Aluminum plate A1100P was pretreated in the same manner as in Example 1, and sulfuric acid 150g/bath temperature was 20°C.
AC electrolysis was performed for 30 minutes at 2.0 A/dm ² to form an anodic oxide film. Then, this aluminum plate was placed in an aqueous solution of 50 g of tartaric acid and 50 g of maleic acid at a bath temperature of 20°C and an AC of 20 volts.
After changing the micropore structure of the anodic oxide film by electrolytic treatment for 10 minutes, a sponge impregnated with a solution of 30 g of oxalic acid was brought into contact with the surface of the aluminum plate, and 20 volts AC was applied to electrolytically treat it for 10 minutes. By doing so, the anodic oxide film is further grown partially. Next, 6.5g of cobalt acetate/
After immersing the aluminum plate in a solution with a pH of 6.8 at a bath temperature of 45°C for 5 minutes and sealing with pure water for 30 minutes, the surface of the aluminum plate had a yellow-green color on the sponge contact area and a yellowish-green color on the other areas. However, a colored film with a pattern of Prones was formed.

[Example 20] Aluminum alloy A6063S was pretreated in the same manner as in Example 1, and then treated with 150 g of sulfuric acid and a bath temperature of 20
Anodization was carried out for 30 minutes at a temperature of 1.0 A/dm ² . This aluminum alloy was then connected to an anode in an aqueous solution of 50 g of phosphoric acid and 20 g of gluconic acid, and subjected to electrolytic treatment for 5 minutes at a bath temperature of 20°C and 18 volts DC to form micropores in the anodic oxide film. The structure has changed. Then phosphorous acid
After partially changing the properties of the anodized film by spraying 100 g of solution, the dried aluminum alloy was sprayed with 10 g of stannous sulfate and 10 g of sulfuric acid.
When electrolytically colored for 2 minutes in a bath with a bath temperature of 20°C and an AC of 10 volts, a yellow-green patterned colored film with red-orange spots was formed.

[Example 21] After pretreating aluminum alloy A6063S in the same manner as in Example 1, sulfuric acid 150g/, bath temperature 20
Anodization treatment was performed for 30 minutes at a temperature of 1.0 A/dm ² at an electric density of 1.0 A/dm 2 . Then, this aluminum alloy was heated in an aqueous solution of 50 g of phenolsulfonic acid and 5 g of oxalic acid at a bath temperature of 25°C and an AC of 30 volts.
Electrolytic treatment was performed for 15 minutes. Next, a part of the aluminum alloy was covered with masking tape, and electrolytic treatment was performed for 10 minutes in the same bath and under the same conditions as in the previous step. After that, the masking tape was removed, and the solution was heated to a bath temperature in an aqueous solution containing 30 g of nickel sulfate, 25 g of tartaric acid, 10 g of ammonium sulfate, and 30 g of boric acid.
When subjected to electrolytic coloring treatment for 4 minutes at 20°C and 16 volts AC, a patterned colored film was formed on the aluminum alloy surface, with the masking area being gray and the other areas being dark greenish bronze.

Claims (1)

[Claims] 1. A process for producing any of the following patterns (a) to (e) on aluminum with an anodized film formed thereon, and phosphoric acid, chromic acid, pyrophosphoric acid, phosphorous acid, The anodic oxide film is electrolytically treated in a bath containing one or more of sulfamic acid, high concentration sulfuric acid of 40V/V% or more, organic acids containing -COOH or -OH groups, or salts thereof. 1. A method for surface treatment of aluminum, which comprises performing an intermediate treatment consisting of a step of changing the structure of micropores, and then coloring the aluminum. (a) One or two of acids, their salts, or bases
A step of electrolytically treating the aluminum after the anodic oxide film has been formed using alternating current or a similar waveform whose polarity changes between positive and negative in an aqueous solution containing at least one species. (b) One or two of acids, salts thereof, or bases.
A step of bringing an aqueous solution containing at least one species into local contact with the surface of the aluminum after the anodic oxide film has been formed and energizing it. (c) A step of partially spraying steam onto the aluminum after the anodic oxide film has been formed. (d) A step of partially masking the aluminum after the anodic oxide film is formed. (e) A step of partially contacting the aluminum after the anodic oxide film has been formed with a solution that inhibits or promotes electrolytic treatment. 2. The aluminum surface treatment method according to claim 1, wherein the intermediate treatment is performed in the order of a step for generating a pattern and a step for changing the micropore structure of the anodic oxide film. 3. The aluminum surface treatment method according to claim 1, wherein the intermediate treatment is performed in the order of a step of changing the micropore structure of the anodic oxide film and a step of creating a pattern.