JPH0631471B2 - Surface treatment method for aluminum-based metal having oxide film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides a surface portion of an oxide-based aluminum-based metal, such as aluminum or an alloy containing aluminum, which has an oxide coating and is provided with color resistance and weather resistance. The present invention relates to a surface treatment method for an aluminum-based metal having an oxide film, which produces an excellent opaque white to off-white substance.

(b) Conventional technology Recently, due to changes in lifestyle and taste, it is required to color semi-finished aluminum-based products used in building materials, nameplates, decorative items, daily necessities or vehicles in pastel colors. In particular, in the fields of daily necessities, decorations, vehicles and building materials, pastel-colored aluminum-based metal products are strongly demanded because they give the viewer a gentle and warm feeling.

By the way, in order to color the aluminum-based metal semi-finished product in a pastel color, first,
It is necessary to color the base opaque white to gray white, and conventionally, the following surface treatment method has been proposed as a method for coloring an aluminum based metal semi-finished product to opaque white to gray white.

That is, a semi-finished aluminum-based product having an anodized film is immersed in or electrolyzed in a solution containing at least one salt of calcium salt, magnesium salt, zinc salt and aluminum salt and sulfuric acid, and then this treatment is performed. It is immersed in or electrolyzed in a solution containing at least one substance that reacts with the product from the salt in the fine pores of the anodic oxide film to form a white to off-white compound (JP-A-60). -197897).

(c) Problems to be Solved by the Invention However, this method is a method for coloring a semi-finished aluminum-based metal product having an anodic oxide film to white or off-white through the above steps, and is obtained by this method. The opaque white to gray-white film does not adhere well to the anodized film on the aluminum-based metal.Therefore, after the anodized film is colored, it may be washed with water, dried, or sealed during the steps such as (a). ) Problems such as film destruction (film loss) and (b) decoloring at the time of sealing, and (c) peeling of the film after sealing, etc. occur. The gray-white film lacks denseness, has poor weather resistance, and has a fatal defect that the coloring component of the white or gray-white film has a small refractive index and low whiteness.

Further, the surface treatment agent used in the above steps could not evenly color the anodized film of aluminum-based metal, resulting in color unevenness, which was not practical.

(d) Means for Solving Problems The present inventors have conducted extensive studies for many years in order to solve the above problems all at once.

As a result, when coloring the oxide film part of the aluminum-based metal semi-finished product having the oxide film to opaque white to grayish white, in the obtained opaque white to grayish white film, its film destruction (film loss) and sealing In order to prevent the occurrence of problems such as decolorization at the time of peeling, further peeling of the film after sealing, and the like, first, at least at least one selected from a sparingly soluble alkaline earth metal salt, aluminum salt, zinc salt or lead salt. Of the poorly soluble metal salt described above is forcibly dissolved or finely dispersed using alums or alums and ammonia, and then an aluminum metal having an oxide film is dipped in this solution (treatment liquid). Or by electrolyzing the aluminum-based metal having an oxide film in this treatment liquid, the oxide film portion of the aluminum-based metal becomes opaque white or grayish white. And color, thereafter, which found that it should Sealing by 2 Danfuana preliminary sealing and the sealing has been led to completion of the present invention.

That is, the surface treatment method of an aluminum-based metal having an oxide film of the first invention of the present application is a method of treating an aluminum-based metal having an oxide film with alums, an organic polar solvent, and a sparingly soluble alkaline earth metal salt, an aluminum salt, PH containing at least one refractory metal salt selected from lead salts or lead salts
Step (A) of immersing in or electrolyzing in an aqueous solution of 0.5 to 5.5; immersing in an aqueous solution containing a fixing agent having an opaque white to off-white film obtained in the above step (A) or A step (B) of electrolyzing in the aqueous solution to perform preliminary sealing, and a step (C) of permanently sealing the aluminum-based metal obtained in the above step (B) with a sealing agent (C) Is.

Further, the surface treatment method for an aluminum-based metal having an oxide film according to the second aspect of the present invention is a method for converting an aluminum-based metal having an oxide film into alums, organic polar solvents, chelate compounds, and sparingly soluble alkaline earth metal salts, Step (A) of immersing or electrolyzing in an aqueous solution having a pH of 0.5 to 5.5 containing at least one kind of sparingly soluble metal salt selected from an aluminum salt, a zinc salt or a lead salt, and the above step (A) The aluminum-based metal having an opaque white to off-white film obtained in (1) is bound to a metal ion of at least one sparingly soluble metal salt selected from the above alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Step (B) of pre-sealing by dipping or electrolyzing in an aqueous solution containing a fixing agent that produces a white to off-white substance, and the aluminum-based metal obtained in the above step (B) is used as a sealing agent. Book seal It is characterized by comprising the step (C) of forming holes.

Further, the surface treatment method for an aluminum-based metal having an oxide film according to the third aspect of the present invention is a method for converting an aluminum-based metal having an oxide film into alums, organic polar solvents, chelate compounds, ammonia and sparingly soluble alkaline earth metals. Step (A) of immersing in or electrolyzing in an aqueous solution having a pH of 0.5 to 5.5 containing at least one refractory metal salt selected from salt, aluminum salt, lead salt, or lead salt, Obtained in A), an aluminum-based metal having an opaque white to off-white film, a salt of the alkaline earth metal, an aluminum salt, a metal ion of at least one sparingly soluble metal salt selected from lead salts. A step (B) of pre-sealing by dipping or electrolyzing in an aqueous solution containing a binder that binds with and produces a white to off-white substance, the aluminum-based material obtained in the step (B) It is characterized by comprising the step (C) of finally sealing the metal with a sealing agent.

Hereinafter, first, the first invention of the present application will be described in detail.

In the present invention, first, an aluminum-based metal having an oxide film, at least one hardly soluble selected from alums and organic polar solvents and poorly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Contains metal salt
The step (A) of immersing or electrolyzing in an aqueous solution having a pH of 0.5 to 5.5 is carried out.

The aluminum-based metal having an oxide film used in the present invention refers to an aluminum-based metal in which an oxide film is formed chemically or electrochemically (anodizing) on the surface of aluminum or an alloy containing aluminum. It is preferable to form an anodized film because a pastel-like film having more excellent properties can be obtained.

Then, in order to form an anodic oxide film on the aluminum-based metal, a known anodic oxidation method is adopted.

For example, inorganic acids consisting of sulfuric acid, phosphoric acid, chromic acid, oxalic acid, paraphenol sulfonic acid, sulfosalicylic acid,
An anodic oxide film is formed by electrolysis by direct current, alternating current, pulse, PR wave, or AC / DC superposition method in an organic acid such as malonic acid or the like or an aqueous solution such as sodium hydroxide, trisodium phosphate or the like.

The alums used in the present invention are soluble in a mixed solution of water and an organic polar solvent described below, and are at least selected from the poorly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts described below. There is no particular limitation as long as it promotes the solubility and dispersibility of one kind of hardly soluble metal salt.

Specific examples of the above alums include potassium aluminum sulfate (potassium alum), sodium aluminum sulfate (sodium alum), rubidium aluminum sulfate, cesium aluminum sulfate, thallium aluminum sulfate, ammonium aluminum sulfate (ammonium alum), potassium gallium sulfate. , Gallium ammonium sulfate, indium ammonium sulfate,
Titanium cesium sulfate, potassium vanadium sulfate, potassium manganese sulfate, potassium rhodium sulfate, potassium chromium sulfate, chromium cesium sulfate, ammonium chromium sulfate, ammonium manganese sulfate, ammonium iron sulfate,
Examples include potassium iron sulfate, ammonium cobalt sulfate, potassium cobalt sulfate, and the like.

Further, as the organic polar solvent used in the present invention, the solubility or dispersibility of at least one sparingly soluble metal salt selected from the sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts described below. And stabilizes the opaque white to off-white substance produced by hydrolysis thereof, but is not particularly limited as long as it is a water-soluble polar solvent, and specifically, for example, Lower alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone and diethyl ketone, ethers, ethers such as diethyl ether, methylamine,
Examples thereof include amines such as ethylamine, monoethanolamine, diethanolamine and triethanolamine, glycols such as ethylene glycol, diethylene glycol, propylene glycol and polyethylene glycol, glycerin, tetrahydrofuran, dimethylformamide and dimethylacetamide.

Specific examples of at least one hardly soluble metal salt selected from poorly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts include magnesium oxide, magnesium ammonium phosphate, magnesium hydroxide, magnesium phosphate, Calcium hydroxide, calcium sulfate, strontium hydroxide, strontium chromate, barium metasilicate, barium fluoride, barium phosphate-barium hydrogen, barium carbonate, barium hexafluorosilicate, barium oxalate, aluminum fluoride, aluminum iodide, Examples thereof include aluminum phosphate, aluminum hydroxide, aluminum oxalate, magnesium dialuminum tetraoxide, barium dialuminum tetraoxide, zinc oxide, zinc phosphate, zinc carbonate, zinc cyanide, lead sulfate and lead carbonate.

Then, in the step (A) in the surface treatment method of an aluminum-based metal having an oxide film of the present invention, in the step (A), the aluminum-based metal having an oxide film is treated with the alum and the organic polar solvent. And at least one sparingly soluble metal salt selected from sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts
It is immersed in an aqueous solution having a pH of 0.5 to 5.5, or electrolyzed in the aqueous solution.

The concentration of the alums is 0.1 to 150 g /
, Preferably 1 to 120 g /, particularly preferably 5 to
It is desirable to set it to 100 g /, and if it is less than 0.1 g /, the concentration will be too thin and the salt of an insoluble alkaline earth metal,
In some cases, the solubility of at least one poorly soluble metal salt selected from aluminum salts, zinc salts or lead salts is poor and sufficient effects may not be obtained. On the contrary, if it exceeds 150 g /, the effects may be limited and rather unfavorable. It is economically unfavorable.

The concentration of the organic polar solvent is 1 to 50% by volume.
Is preferred.

That is, in the surface treatment method of the present invention, the alum described above, the solubility or dispersion of at least one sparingly soluble metal salt selected from sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. The surface properties of the aluminum-based metal having an oxide film with excellent properties by simply immersing the aluminum-based metal having an oxide film in this treatment liquid or by electrolyzing the aluminum-based metal having an oxide film in this treatment liquid. However, if the concentration of the organic polar solvent is less than 1% by volume, the effect may not be sufficiently obtained, and if it exceeds 50% by volume, the concentration may be high. It is preferable because it influences the solubility of at least one hardly soluble metal salt selected from alums and poorly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. There.

Then, the aqueous solution used in this step (A) is at least one hardly soluble metal selected from the above-mentioned alums and organic polar solvents and poorly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. A salt is an essential component, and water and, if desired, a pH adjuster are added to this, and the pH of this aqueous solution is in the range of 0.5 to 5.5, particularly 1.
It is desirable to set it in the range of 5 to 4, and if the pH is less than 0.5, the acidity becomes too high and the film may be destroyed. Conversely, if the pH exceeds 5.5, it was dissolved. At least one kind of sparingly soluble metal salt selected from alkaline earth metal salt, aluminum salt, zinc salt or lead salt may be hydrolyzed, and the surface treatment agent may be deteriorated during storage or handling. Moreover, when an aluminum-based metal having an oxide film is immersed in an aqueous solution, or when an aluminum-based metal having an oxide film is electrolyzed in an aqueous solution, a salt of an alkaline earth metal formed by hydrolysis or the like, an aluminum salt, a zinc salt. Alternatively, particles of products such as oxides of at least one poorly soluble metal salt selected from lead salts become too large to easily penetrate into the surface of the aluminum-based metal, or a dense film is formed. It may not be obtained, which is not preferable.

And in this pH range, several molecules of hydrated oxide of at least one sparingly soluble metal salt selected from alkaline earth metal salt, aluminum salt, zinc salt or lead salt, slightly turbid hydrosol It is understood that it has become.

The pH adjusting agent, sulfuric acid, inorganic acids such as phosphoric acid, acetic acid, citric acid, succinic acid, gluconic acid, glycine, malonic acid, oxalic acid, organic acids such as formic acid, hydroxides of alkali metals, carbonates Alternatively, bicarbonates, ammonia, alkali metal salts of organic acids and the like can be mentioned. The alkali metal salts of these acids or bases or organic acids may be used alone or in combination of two or more, and the combined use thereof may be more effective in some cases.

In the present invention, the aluminum-based metal having an oxide film is immersed in the aqueous solution, and in the pretreatment of the surface thereof, the aqueous solution is charged into a treatment tank, the concentration is adjusted with water if desired, and the temperature of the aqueous solution is usually , Room temperature to 75 ° C,
The temperature is preferably adjusted to 40 to 70 ° C., and the above aluminum-based metal is added to this solution for usually 10 seconds to 30 minutes, preferably 1
It only needs to be immersed for 20 minutes to 20 minutes.

Also, in the present invention, the aluminum-based metal having an oxide film may be pretreated by immersing it in the above aqueous solution and electrolyzing in the aqueous solution.
The above aqueous solution may be charged into a treatment tank, the concentration thereof may be adjusted in the same manner as above, and the electrolytic treatment may be carried out in the aqueous solution by a known method such as a direct current method, an alternating current method, a pulse method, a PR method or an AC / DC superposition method. is there.

In this case, electrolysis conditions include a liquid temperature of room temperature to 80 ° C., preferably 20 to 70 ° C., a voltage of 1 to 50 V, and a current density of 1 to 150.
A / m ² , electrolysis time 10 seconds to 30 minutes, preferably 1 minute to 2
0 minutes.

In the present invention, next, the aluminum-based metal having an opaque white to off-white coating obtained in the step (A) is selected from the above alkaline earth metal salts, aluminum salts, zinc salts or lead salts. And performing a step (B) of pre-sealing by dipping in an aqueous solution containing a binder that binds to the metal ions of at least one hardly soluble metal salt to form a white to off-white substance or electrolyzing in the aqueous solution. .

The fixing agent used in this step (B) is one that binds with the metal ion of the following metal salt to form a white to off-white substance, and this step (B) is a pore-sealing step in the step (C) described later. Pre-sealing is done to ensure that.

The above-mentioned fixing agent is an aluminum-based metal having the above-mentioned oxide film, and expands the micropores in the oxide film portion to facilitate the intrusion of the following metal salt, and the following sparingly soluble alkaline earth in the expanded micropores. It facilitates the invasion of metals, and the products such as the invaded alkaline earth metal and the fixing agent and the hydrolyzate from the sparingly soluble alkaline earth metal are allowed to grow in the oxide film portion. This accelerated product is filled in the fine pores in the oxide film portion and closes the fine pores, and the products are adsorbed to each other and are more strongly and electrically adsorbed in the fine pores. The purpose of this is to prevent the film from breaking or coming off (bleaching) at the time of sealing.

Specific examples of the fixing agent include phosphoric acid, sodium phosphate, sodium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, boric acid, sodium borate, potassium borate, sodium silicate, potassium silicate, and chromium. Examples thereof include potassium acid, sulfuric acid, sodium sulfate, sodium hydrogensulfate, potassium sulfate, potassium hydrogensulfate, alkali metal hydroxides, carbonates or bicarbonates, and one kind of these fixing agents, or two kinds if desired. The above may be used in combination, and in some cases, the combination of two or more may be more effective.

The concentration of the fixing agent is 0.1 to 300 g /, preferably 0.5 to 200 g /, particularly preferably 1 to 10 g.
It is desirable to set the concentration to 0 g /, and if it is less than 0.1 g /, the concentration becomes too thin and the effect as a fixing agent becomes insufficient. If it is destroyed or the liquid temperature is lowered (for example, in winter), the sticking agent may be precipitated and the concentration may be changed, which may deteriorate the characteristics of the coating, which is not preferable.

In the present invention, an aluminum-based metal having an oxide film is immersed in an aqueous solution containing the above-mentioned adhesive agent, and when the surface portion thereof is pretreated, this aqueous solution is charged into a treatment tank, and the concentration is adjusted with water if desired, The temperature is usually adjusted to room temperature to 75 ° C, preferably 40 to 70 ° C, and the aluminum-based metal is added to this solution for 10 seconds to 30 minutes.
It is preferable to soak for 1 to 20 minutes.

Further, in the present invention, the aluminum-based metal having an oxide film may be immersed in the above aqueous solution, and the surface portion thereof may be pretreated by electrolysis in the solution. In this case, the aqueous solution is charged in a treatment tank, The concentration is adjusted in the same manner as above, and in the aqueous solution, a direct current method, an alternating current method, a pulse method,
The electrolytic treatment may be carried out by a known method such as the PR method or the AC / DC superposition method.

In this case, electrolysis conditions include a liquid temperature of room temperature to 80 ° C., preferably 20 to 70 ° C., a voltage of 1 to 50 V, and a current density of 1 to 150.
A / m ² , electrolysis time 10 seconds to 30 minutes, preferably 1 minute to 2
0 minutes.

In the present invention, finally, the step (C) of finally sealing the aluminum-based metal obtained in the step (B) with a sealing agent is carried out.

This step (C) reliably seals the aluminum-based metal that has been pre-sealed through the above step (B), so that film destruction (film loss), decoloring at the time of sealing, and further after sealing It is for surely preventing problems such as peeling of the film of
It is for forming a film having excellent characteristics on an oxide film part of an aluminum-based metal.

The sealing agent is not particularly limited as long as it is used for sealing the oxide film of the aluminum-based metal having an oxide film, and various sealing agents can be used.

In the step (C), the aluminum-based metal obtained through the step (B) is immersed in an aqueous solution containing a pore-sealing agent, and in order to reliably seal the surface, the aqueous solution is charged into a treatment tank, and if desired. The concentration is adjusted with water, the temperature of the aqueous solution is usually adjusted to room temperature to 75 ° C., preferably 40 to 70 ° C., and the aluminum metal is added to this solution usually
The immersion may be performed for seconds to 30 minutes, preferably 1 minute to 20 minutes.

Further, in this step (C), the aluminum-based metal obtained through the step (B) may be immersed in the aqueous solution, and the surface may be surely sealed by electrolysis in the solution,
In this case, this aqueous solution is charged into a treatment tank, the concentration is adjusted in the same manner as above, and the aqueous solution is subjected to electrolytic treatment by a known method such as a direct current method, an alternating current method, a pulse method, a PR method or an AC / DC superposition method. Is good.

In this case, electrolysis conditions include a liquid temperature of room temperature to 80 ° C., preferably 20 to 70 ° C., a voltage of 1 to 50 V, and a current density of 1 to 150.
A / m ² , electrolysis time 10 seconds to 30 minutes, preferably 1 minute to 2
0 minutes.

Next, the second invention of the present application will be described in detail.

The second invention of the present application relates to an improvement of the first invention.

That is, the aluminum-based metal having an oxide film, at least one sparingly soluble metal salt selected from alums, organic acid polar solvents, chelate compounds and sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. PH including
Step (A) of immersing in or electrolyzing in an aqueous solution of 0.5 to 5.5, the aluminum-based metal having an opaque white to off-white coating obtained in the step (A) is treated with the above alkaline earth. Immersion in or in an aqueous solution containing an adhesive that forms a white to off-white substance by combining with metal ions of at least one sparingly soluble metal salt selected from metal salts, aluminum salts, zinc salts or lead salts. It comprises a step (B) of electrolyzing and pre-sealing, and a step (C) of main-sealing the aluminum-based metal obtained in the step (B) with a sealing agent.

The second invention of the present application is the step in the above-mentioned first invention.
A chelate compound is added to the aqueous solution used in (A), requirements other than the addition of the chelate compound, that is, alum, organic acid polar solvent, sparingly soluble alkaline earth metal salt, aluminum salt, zinc salt or lead. The at least one kind of sparingly soluble metal salt selected from salts, the fixing agent and the pore-sealing agent, the concentration or pH range thereof, and the immersion and electrolysis conditions of the aluminum-based metal having an oxide film are the same as those of the first invention. is there.

Then, the chelate compound used in the present invention has the step (A)
The stability of at least one hardly soluble metal salt selected from alums and alkaline earth metal salts, aluminum salts, zinc salts or lead salts in an aqueous solution, and the aluminum-based metal in the aqueous solution of this step (A) Or at least one selected from the group consisting of alkaline earth metal salts, aluminum salts, zinc salts or lead salts formed on the surface of the aluminum-based metal when it is electrolyzed in the aqueous solution of step (A). It stabilizes a hydrosol of an oxide of a sparingly soluble metal salt.

Further, it facilitates the bonding of the oxide film portion of the aluminum-based metal having an oxide film and the product of at least one sparingly soluble metal salt selected from alkaline earth metal salts, aluminum salts, zinc salts or lead salts. It has the effect of

Specific examples of the chelate compound include ethylenediaminetetraacetic acid and its sodium salt, trans-1,
2-cyclohexanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminediacetic acid, 3,6-dioxa-1,8-octanediaminetetraacetic acid, N- (2-hydroxyethyl) ethylenediaminetriacetic acid, N- (2-hydroxyethyl) Amino compounds having two or more amine groups in one molecule such as iminodiacetic acid, polyaminocarboxylic acids such as triethylenetetramine hexaacetic acid, diamines such as ethylenediamine, triamines such as diethylenetriamine, triethanolamine and triethylenetetramine.
Examples include polybasic acids such as ethyl acetoacetate, nitrilotriacetic acid, formalin, oxalic acid, maleic acid, tartaric acid, malic acid, citric acid, succinic acid, gluconic acid or glycine, and soluble metal salts thereof. Among these, a chelate compound insoluble in water is also included, but it is dissolved by adding an organic polar solvent, that is, in a mixture of water and an organic polar solvent.

The concentration of the chelate compound used depends on the type and concentration of at least one hardly soluble metal salt selected from alums, organic polar solvents and alkaline earth metal salts, aluminum salts, zinc salts or lead salts, Generally, a range of 0.1 to 50 g / is preferable, and 0.1 g /
If the amount is less than 50 g / g, the effect is poor, and if it exceeds 50 g / g, the effect is limited.

Further, the third invention of the present application will be described in detail.

A third invention of the present application relates to an improvement of the second invention.

That is, aluminum-based metal having an oxide film, alums, organic polar solvents, chelate compounds, ammonia and sparingly soluble alkaline earth metal salts, aluminum salts,
Step (A) of immersing in or electrolyzing in an aqueous solution of pH 0.5 to 5.5 containing at least one hardly soluble metal salt selected from zinc salt or lead salt, obtained in the above step (A) , An aluminum-based metal having an opaque white to off-white film is combined with a metal ion of at least one sparingly soluble metal salt selected from the above-mentioned alkaline earth metal salts, aluminum salts, zinc salts or lead salts to produce white to Step (B) of pre-sealing by dipping or electrolyzing in an aqueous solution containing a sticking agent that produces an off-white substance, the aluminum-based metal obtained in the above step (B) is fully sealed with a sealing agent. The step (C) of

The third invention of the present application is the process of the above-mentioned second invention.
Ammonia is added to the aqueous solution used in (A), whereby the solubility of at least one sparingly soluble metal salt selected from sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Is further improved, by adding ammonia in this way at least one poorly soluble alkaline earth metal salt of poorer solubility, aluminum salt, zinc salt or at least one poorly soluble selected from lead salts The solubility of the metal salt is further improved, other requirements, namely, alums, organic polar solvents,
At least one sparingly soluble metal salt selected from a chelate compound, a sparingly soluble alkaline earth metal salt, an aluminum salt, a zinc salt or a lead salt, a sticking agent and a sealing agent, and their concentrations or
The pH range and the conditions for immersion and electrolysis of the aluminum-based metal having an oxide film are the same as those of the second invention.

The ammonia used in the present invention includes ammonia, aqueous ammonia, ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, ammonium citrate, hydroxylammonium sulfate, ammonium hydrogen fluoride, ammonium chlorate, ammonium perchlorate, and fluorine. Ammonium iodide, ammonium iodide, ammonium iodate, ammonium periodate,
Ammonium sulfide, ammonium pentasulfide, ammonium sulfite monohydrate, ammonium hydrogen sulfite, ammonium hydrogen sulfate, ammonium thiosulfate, ammonium amidosulfate, ammonium selenite, ammonium selenite, ammonium phosphate, diammonium hydrogen phosphate,
Ammonium dihydrogen phosphate, ammonium cyanide, ammonium cyanate, ammonium thiocyanate, ammonium carbonate, ammonium hydrogen carbonate, ammonium hydrogen carbamate, ammonium metaborate, ammonium tetraborate, ammonium metavanadate (V),
Examples thereof include ammonium chromate and ammonium dichromate.

And this ammonia may use 1 type, and may use 2 or more types together if desired.

By the way, when ammonia is added to the aqueous solution used in the step (A) in this way, the solubility of at least one hardly soluble metal salt selected from a poorly soluble alkaline earth metal salt, an aluminum salt, a zinc salt or a lead salt. It is not clear the reason for the improvement of the above, but the ammonium ion forms a complex by binding with at least one poorly soluble metal salt selected from the alkaline earth metal salt, aluminum salt, zinc salt or lead salt. It is understood that at least one refractory metal salt selected from alkaline earth metal salts, aluminum salts, zinc salts or lead salts is stabilized and the solubility is improved.

The concentration of the above-mentioned ammonia varies depending on the type and combination of alums, organic polar solvents, chelate compounds or ammonia used, etc.
It is appropriately selected from the range of 100 g /, preferably 3 to 50 g /.

(e) Action The present invention has the above-mentioned constitution, and because the surface treatment agent contains alum and an organic polar solvent or alum and an organic polar solvent and ammonia, it is difficult to understand the alkaline earth metal. It is possible to improve the solubility or dispersibility in the form of fine particles of at least one refractory metal salt selected from salts, aluminum salts, zinc salts or lead salts, and moreover, alkaline earth metal salts and aluminum salts. , At least one sparingly soluble metal salt selected from zinc salt or lead salt, pH change, that is, the aluminum-based metal having an oxide film is immersed in the aqueous solution of step (A), or the aluminum-based metal step ( PH by electrolysis in A)
When a hydrosol such as an oxide of at least one sparingly soluble metal salt selected from a finely divided alkaline earth metal salt, aluminum salt, zinc salt or lead salt is hydrolyzed by the change of The solvent deprives the water molecules coordinated to the oxide of at least one sparingly soluble metal salt selected from alkaline earth metal salts, aluminum salts, zinc salts or lead salts to accelerate hydrolysis, thereby The surface of the aluminum-based metal has a function of continuously producing a fine hydrosol of the oxide or the like.

Further, the surface treatment method of an aluminum-based metal having an oxide film of the present invention is performed by pre-sealing the aluminum-based metal treated in step (A) with a fixing agent (step B) and main sealing with a sealing agent (step C By performing the two-stage sealing of (1), the sealing is surely performed, and it has an action of preventing the opaque white or gray-white film from breaking (coating loss), decoloring at the time of sealing, and peeling of the film.

In other words, in the oxide film portion, the product from the sparingly soluble alkaline earth metal bonds with the adhesive and grows. Therefore, at the time of sealing, the grown product is filled in the fine pores. In this state, the micropores are closed and the products stick to each other, and the film is less likely to be broken or separated (bleaching) when electrically sealed by being adsorbed in the micropores.
That is, preliminary sealing occurs, and as a result, decoloring at the time of main sealing is prevented and the aluminum-based metal after sealing is uniformly colored.

(f) Examples Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited thereto.

Preparation of Pure Aluminum Plate Having Anodic Oxide Film The anodic oxide film used in each of Examples and Comparative Examples described below is a pure aluminum plate after pretreatment such as normal degreasing, and then a sulfuric acid temperature of 180 g / It was obtained by direct current electrolysis for 25 minutes under the conditions of a bath temperature of 20 ° C. and a current density of 2 A / dm ² .

In this case, the thickness of the anodized film was 15 μm.

Examples 1 to 7 The aluminum plate was placed in an aqueous solution shown in Table 1 at a temperature of 6
Immerse at 5 ° C. for 15 minutes (step A), preliminarily seal the aluminum plate thus obtained in a 15 g / water glass aqueous solution as a fixing agent at a temperature of 98 ° C. for 5 minutes (step B),
Next, the main sealing was performed at a temperature of 98 ° C. for 10 minutes in an aqueous solution of 3.5 g / sealing salt AS (manufactured by Sealing Salt AS Sand Co.).

Comparative Example 1 The above aluminum plate was treated with an aqueous solution (30 ° C.) containing 30 g of calcium acetate and 0.5 g of sulfuric acid at an alternating voltage of 20.
After electrolysis was carried out for 20 minutes with V, washing with water, and electrolysis with an aqueous solution of phosphoric acid 30 g / (30 ° C.) for 20 minutes with an AC voltage of 20 V, an opaque white film was obtained on the surface of the aluminum plate.

Comparative Example 2 The above aluminum plate was immersed in an aqueous solution of aluminum sulfate of 50 g / and sulfuric acid of 0.5 g / (20 ° C.) for 20 minutes, washed with water, and then immersed in an aqueous solution of phosphoric acid of 20 g / (40 ° C.) for 20 minutes to obtain aluminum. An opaque white film was obtained on the surface of the plate.

Comparative Example 3 The above aluminum plate was treated with an aqueous solution (25 ° C.) of zinc sulfate 15 g / and sulfuric acid 0.5 g / at an alternating voltage of 20 V for 1 hour.
After electrolysis for 0 minutes and washing with water, electrolysis was performed with an aqueous solution of oxalic acid of 20 g / 25 ° C. for 20 minutes at a DC voltage of 15 V to obtain an opaque white film on the surface of the aluminum plate.

Comparative Example 4 The above aluminum plate was immersed in an aqueous solution (60 ° C.) of 25 g / calcium acetate and 0.5 g / sulfuric acid for 30 minutes, washed with water, and then washed with an aqueous solution of 20 g / sulfuric acid (35 ° C.) at an AC voltage of 20 V for 20 minutes. Electrolysis was performed to obtain an opaque white film on the surface of the aluminum plate.

Comparative Example 5 The aluminum plate was treated with an aqueous solution (25 ° C.) containing 15 g of calcium acetate and 0.5 g of sulfuric acid at a DC voltage of 15.
Electrolyze at V for 5 minutes, wash with water, and then use 30g / sodium phosphate.
It was immersed in the aqueous solution (40 ° C.) for 20 minutes to obtain an opaque white film on the surface of the aluminum plate.

Comparative Example 6 The above aluminum plate was treated with an aqueous solution (30 ° C.) of magnesium nitrate 30 g / and sulfuric acid 1 g / and an AC voltage of 20 V was applied.
At 10 ° C. for 10 minutes, washed with water, and immersed in an aqueous solution of sodium carbonate (30 g / 40 ° C.) for 20 minutes to obtain an opaque white film on the surface of the aluminum plate.

Comparative Example 7 The above aluminum plate was treated with an aqueous solution (40 ° C.) of magnesium nitrate 20 g / and sulfuric acid 1 g / at an alternating voltage of 20 V.
At 10 ° C. for 10 minutes, washed with water, and immersed in an aqueous solution of sodium carbonate (30 g / 40 ° C.) for 20 minutes to obtain an opaque white film on the surface of the aluminum plate.

Examples 8 to 14 Using the aqueous solution shown in Table 2 (aqueous solution used in step A),
The aqueous solution used in the step (B) was the same as that used in the above example except that 110 g / phosphoric acid aqueous solution was used.

Examples 15 to 31 Using the aqueous solution shown in Table 3 (aqueous solution used in step A),
As the aqueous solution used in the step (B), sodium silicate 20
What was obtained in the same manner as in the above Example was used except that an aqueous solution of g / was used.

Table 4 shows the results of the white to off-white coloring tests of the above Examples and Comparative Examples.

As shown in the results of the color tone in Table 4, the anodized film colored white by the surface treatment method of the first invention of the present application was uniform, and almost no color unevenness was observed.

In addition, this white film did not cause film destruction during the subsequent steps such as washing with water and drying, and there were almost no problems such as decoloring by the pore-sealing agent and film peeling after sealing.

The second invention of the present application, that is, the solution obtained by adding the chelate compound to the aqueous solution of the step (A) in the first invention of the present application, was more uniformly colored (white) and had excellent weather resistance.

Further, this white film did not cause problems such as film destruction and decolorization, as in the first invention.

Furthermore, a third invention of the present application is the second invention of the present application in which ammonia is added to the aqueous solution of the step (A), whereby a sparingly soluble alkaline earth metal salt, aluminum salt, zinc salt or It was found that the solubility of at least one hardly soluble metal salt selected from lead salts can be further improved and an excellent white film can be obtained.

Further, this white film did not cause problems such as film destruction and decolorization, as in the first invention.

On the other hand, in each of the comparative examples, color unevenness is large and lacks in practicality, and also good results are not obtained with respect to weather resistance, and further, film destruction occurs during steps such as washing with water and drying. However, problems such as discoloration by the sealing agent and peeling of the film after sealing occurred.

In addition, according to the method of the present invention, the aluminum-based metal having an oxide film can be uniformly colored by simply immersing it in an aqueous solution for coloring, and therefore the sparingly soluble alkaline earth metals and products derived therefrom can be electrically charged. A uniform and dense film can also be obtained by the electrolysis method of pulling into the fine pores.

(g) Effect of the invention The surface treatment method of the present invention is carried out by immersing an aluminum-based metal having an oxide film, or by electrolyzing in the solution to adjust the pH of the solution.
Is changed, that is, at least one hardly soluble metal salt selected from alkaline earth metal salts, aluminum salts, zinc salts or lead salts is hydrolyzed at the site where the pH is changed, that is, on the surface or inside of the oxide film. The white to off-white substance produced by the method uniformly and densely colors the above-mentioned coating part, and the opaque white to off-white coating thus obtained is surely secured by the two-step sealing of the pre-sealing and the main sealing. Since the film is sealed, there is no problem such as film destruction after formation of this film, discoloration by the sealing agent and film peeling after sealing, and it is uniform and dense with excellent weather resistance and durability. It has the effect of forming a white or gray-white film.

Claims (24)

[Claims] 1. An aluminum-based metal having an oxide film,
PH 0.5-containing alum and an organic polar solvent and at least one sparingly soluble metal salt selected from sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts
Step of immersing in the aqueous solution of 5.5 or electrolyzing in the aqueous solution
(A), obtained in the step (A), an aluminum-based metal having an opaque white to off-white film, at least one selected from the above alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Step (B) of pre-sealing by dipping in or electrolyzing in an aqueous solution containing a binder that binds with metal ions of a sparingly soluble metal salt to form a white to off-white substance, and obtains in the above step (B) A method of surface-treating an aluminum-based metal having an oxide film, comprising the step (C) of finally sealing the obtained aluminum-based metal with a sealing agent. 2. The concentration of alums is 0.1 to 150 g /
The surface treatment method for an aluminum-based metal having an oxide film according to claim 1. 3. The surface treatment method for an aluminum-based metal having an oxide film according to claim 2, wherein the concentration of alums is 1 to 120 g /. 4. The surface treatment method for an aluminum-based metal having an oxide film according to any one of claims 1 to 3, wherein the concentration of the organic polar solvent is 1 to 50% by volume. 5. The fixing agent is phosphoric acid, sodium phosphate, sodium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, boric acid, sodium borate, potassium borate, sodium silicate, potassium silicate, chromic acid. The potassium, sulfuric acid, sodium sulfate, sodium hydrogensulfate, potassium sulfate, potassium hydrogensulfate, an alkali metal hydroxide, carbonate or bicarbonate, according to any one of claims 1 to 4. A method for surface treatment of an aluminum-based metal having an oxide film. 6. The surface treatment method for an aluminum-based metal having an oxide film according to claim 1, wherein the concentration of the fixing agent is 0.1 to 300 g /. 7. The surface treatment method for an aluminum-based metal having an oxide film according to any one of claims 1 to 6, wherein the concentration of the pore-sealing agent is 0.1 to 200 g /. 8. An aluminum-based metal having an oxide film,
Aqueous solution having a pH of 0.5 to 5.5 containing at least one hardly soluble metal salt selected from alums, organic polar solvents, chelate compounds and sparingly soluble alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Step (A) of dipping in or electrolysis in an aqueous solution thereof, obtained in the step (A), an aluminum-based metal having an opaque white to off-white film, the alkaline earth metal salt, aluminum salt, zinc salt Alternatively, a step of pre-sealing by dipping in an aqueous solution containing a fixing agent that binds to a metal ion of at least one poorly soluble metal salt selected from lead salts to form a white to off-white substance or electrolyzing in the aqueous solution ( A surface treatment method for an aluminum-based metal having an oxide film, comprising: (B) a main sealing of the aluminum-based metal obtained in the above step (B) with a sealing agent. 9. The concentration of alums is 0.1 to 150 g /
The method for surface treatment of an aluminum-based metal having an oxide film according to claim 8. 10. The concentration of alums is 1 to 120 g /
The surface treatment method for an aluminum-based metal having an oxide film according to claim 8 or 9. 11. The concentration of the organic polar solvent is 1 to 50% by volume.
A method for surface treatment of an aluminum-based metal having an oxide film according to any one of claims 8 to 10. 12. The chelate compound is a polyaminocarboxylic acid, a polybasic acid, or an amine compound having two or more amine groups in one molecule.
A method for surface treatment of an aluminum-based metal having an oxide film according to any one of items 1. 13. The fixing agent is phosphoric acid, sodium phosphate, sodium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, boric acid, sodium borate, potassium borate, sodium silicate, potassium silicate, chromic acid. potassium,
The oxide film according to any one of claims 8 to 12, which is sulfuric acid, sodium sulfate, sodium hydrogen sulfate, potassium sulfate, potassium hydrogen sulfate, an alkali metal hydroxide, carbonate or bicarbonate. A method for surface treatment of an aluminum-based metal having: 14. The surface treatment method for an aluminum-based metal having an oxide film according to claim 8, wherein the concentration of the fixing agent is 0.1 to 300 g /. 15. The method for surface treatment of an aluminum-based metal having an oxide film according to any one of claims 8 to 14, wherein the concentration of the pore-sealing agent is 0.1 to 200 g /. 16. An aluminium-based metal having an oxide film, an alum, an organic polar solvent, a chelate compound,
Immersion in or electrolysis in an aqueous solution of pH 0.5 to 5.5 containing ammonia and at least one sparingly soluble metal salt selected from a sparingly soluble alkaline earth metal salt, aluminum salt, zinc salt or lead salt. Step (A), the aluminum-based metal having an opaque white to off-white coating obtained in the step (A) is at least selected from the above alkaline earth metal salts, aluminum salts, zinc salts or lead salts. Step (B) of pre-sealing by dipping or electrolyzing in an aqueous solution containing a fixing agent that forms a white to off-white substance by combining with a metal ion of a kind of sparingly soluble metal salt (B), the above step (B) A method for surface-treating an aluminum-based metal having an oxide film, which comprises the step (C) of finally sealing the aluminum-based metal obtained in 1. with a sealing agent. 17. The concentration of alums is 0.1 to 150 g.
The surface treatment method for an aluminum-based metal having an oxide film according to claim 16, wherein the surface treatment method is /. 18. The concentration of alums is 1 to 120 g /
The surface treatment method for an aluminum-based metal having an oxide film according to claim 17. 19. The concentration of the organic polar solvent is 1 to 50% by volume.
A method for surface treatment of an aluminum-based metal having an oxide film according to any one of claims 16 to 18, which is 20. The oxide film according to any one of claims 16 to 19, wherein the chelate compound is a polyaminocarboxylic acid, a polybasic acid or an amine compound having two or more amine groups in one molecule. A method for surface treatment of an aluminum-based metal having: 21. The surface treatment method for an aluminum-based metal having an oxide film according to any one of claims 16 to 20, wherein the ammonia is ammonia, ammonia water or an ammonium salt. 22. The fixing agent is phosphoric acid, sodium phosphate, sodium hydrogen phosphate, potassium phosphate, potassium hydrogen phosphate, boric acid, sodium borate, potassium borate, sodium silicate, potassium silicate, chromic acid. potassium,
The oxide film according to any one of claims 16 to 21, which is sulfuric acid, sodium sulfate, sodium hydrogen sulfate, potassium sulfate, potassium hydrogen sulfate, an alkali metal hydroxide, carbonate or bicarbonate. A method for surface treatment of an aluminum-based metal having: 23. The surface treatment method for an aluminum-based metal having an oxide film according to any one of claims 16 to 22, wherein the concentration of the fixing agent is 0.1 to 300 g /. 24. The surface treatment method for an aluminum-based metal having an oxide film according to any one of claims 16 to 23, wherein the concentration of the pore-sealing agent is 0.1 to 200 g /.