JPH0320496A - Sealant for aluminum-based metal having oxide film and method for sealing oxide film of aluminum-based metal using the same - Google Patents

Abstract

PURPOSE:To provide the sealant capable of uniformly sealing the oxide film without rainbow-coloring the treated film and discoloring the dye by forming the sealant from the titanium fluoride, fluorotitanate or mixture of the salts and fluorozirconate as the essential components. CONSTITUTION:The sealant is an aq. soln. contg. titanium fluoride, a fluorotitanate or a mixture of the salts and a fluorozirconate. The oxide film of Al or an Al alloy is preliminarily sealed in the aq. soln. and then normally sealed. Sodium hexafluorotitanate (IV), potassium hexafluorotitanate (IV) or ammonium hexafluortitanate (IV) are exemplified as the fluorotitanate.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a sealing agent for aluminum-based metals having an oxide film and a method for sealing an oxide film of aluminum-based metals using the same. .

(b) Prior Art The following method has been proposed as a method for sealing an anodic oxide film of aluminum or its alloy (hereinafter referred to as aluminum-based metal).

That is, ■ an aluminum-based metal with an anodic oxide film,
This method involves heat treatment at 50 to 100°C in an aqueous solution of zirconium potassium fluoride at a concentration of 0.1 to 4 g/l (Japanese Patent Publication No. 49-23-086). ■It is a method of low-temperature treatment of aluminum-based metals with anodized oxide films in an aqueous solution of zirconium fluoride salt (
(Japanese Patent Application Laid-Open No. 62-130295). (c) Problems to be Solved by the Invention The above method (■) can impart excellent corrosion resistance to the anodic oxide film, but the treated film reflects light and takes on an iridescent color, reducing its commercial value. There was a drawback. Also,
There were also problems such as suspended solids caused by potassium zirconium fluoride, which adhered to the film surface and caused uneven sealing. In addition, in the method of ■ above, +
Although there is no AM, the sealing process is performed at low temperatures, which results in insufficient sealing and discoloration, which requires 21-day shinging for more than one day. The present invention provides a treatment film by sealing an aluminum metal having an oxide film in an aqueous solution containing titanium fluoride, a titanium fluoride salt, or a mixture of at least one of these salts and a zirconium fluoride salt. A pore-sealing agent for aluminum-based metals that does not exhibit rainbow colors, does not cause dye bleeding or decolorization, can seal pores uniformly, and has an excellent pore-sealing effect, and aluminum-based metals using the same. The purpose of this study is to provide a method for sealing oxide films. (d) Means for Solving the Problems In order to achieve the above-mentioned goals, the sealing agent for aluminum-based metals and the method for sealing oxide films of aluminum-based metals using the same of the present invention include: A technical measure is taken to seal an oxide film of an aluminum metal in an aqueous solution containing titanium fluoride, a titanium fluoride salt, or a mixture of these salts and a zirconium fluoride salt.

That is, the sealing agent for an aluminum-based metal having an oxide film according to claim 1 is a pore-sealing agent for sealing an oxide film of an aluminum-based metal, wherein the pore-sealing agent is made of titanium fluoride. , a titanium fluoride salt, or a mixture of at least one of these salts and a zirconium 77ide salt. Hereinafter, first, this pore sealing agent will be explained in detail.

In the present invention, an aluminum-based metal having an oxide film refers to aluminum or an aluminum-based alloy having
It refers to an aluminum-based metal that has been formed with an oxide film chemically or electrochemically (anodic oxide film 115I), and an anodic oxide film is particularly preferred because of its excellent properties. A known anodic oxidation method is used to form an anodic oxide film on the aluminum metal. Specifically, for example, inorganic acids such as sulfuric acid, phosphoric acid, and chromic acid, organic acids such as oxalic acid, para-7-enolsulfonic acid, sulfosalicylic acid, and malonic acid, or aqueous solutions such as sodium hydroxide and trisodium phosphate. In this process, an anodic oxide film is formed by electrolysis using direct current, alternating current, pulse, PR method, or AC/DC superposition method. Incidentally, in the present invention, the above-mentioned oxide film includes one colored with a dye or a metal salt.

The above-mentioned aluminum-based metal having an oxide film is sealed in a sealing agent, and in the present invention, the sealing agent is titanium fluoride, a titanium fluoride salt, or at least one of these salts. The most significant feature is that it consists of an aqueous solution containing a mixture of zirconium salt and zirconium 77ide salt.

That is, a pore sealing agent that essentially contains titanium fluoride, a titanium fluoride salt, or a mixture of at least one of these salts and a zirconium fluoride salt does not have the same problems as when only a zirconium fluoride salt is used. This does not occur, and for the reasons described below, an excellent sealing effect can be obtained. As the titanium fluoride salt, hexa7fluorotitanium (F/ )F! ! Sodium, hexa7fluoro titanium (
■) l! ! Potassium or hexa7fluorotitanium (IV)
Examples include ammonium acid.

Titanium fluoride and titanium 77ide salt can be used alone or in combination. Incidentally, in the present invention, zirconium fluoride salt is not used alone because the above-mentioned problems occur when used alone, but a mixture of titanium fluoride and/or the titanium fluoride salt and zirconium 77ide salt is used. can be suitably used. Examples of the fluoridated zirconium salt include sodium hexa7fluorozirconium (■), hexa7fluorozirconium (I
V) acid potassium or hebuta-7fluorozirconium (1”
/) acid ammonium, etc.

In the pore sealing agent of the present invention, the concentration of these metal salts is 0.1 to 100 g/l, particularly 0.5 to 50 g/l.
It is desirable that the concentration of this metal salt be in the range of 0.
If it is less than 1 g/f, a sealing effect with sufficiently excellent corrosion resistance may not be obtained, and if it exceeds 100 g/f, it is not only meaningless but also uneconomical.

The pH of this pore sealing agent is preferably in the range of 3.5 to 6.5, especially in the range of 4 to 6. If the pH is less than 3.5, the acidity will be too high and the film will be damaged. On the other hand, if the pH exceeds 6.5, the metal salts may be hydrolyzed and change during storage, which is not preferable because a uniform sealing effect may not be obtained.

Examples of the pH adjusting agent include inorganic acids such as sulfuric acid and phosphoric acid, organic acids such as acetic acid, citric acid, succinic acid, gluconic acid, glycine, malonic acid, oxalic acid, and formic acid, alkali metal hydroxides, carbonates, etc. Examples include bicarbonate, ammonia, alkali metal salts of organic acids, and various amines. These salts or bases or alkali metal salts of organic acids are
One type may be used or two or more types may be used in combination, and there are cases where the combination is particularly effective.

Incidentally, a surfactant may be added to the pore sealing agent of the present invention in an amount of 0.5 to 50 g/1, if desired.

By adding a surfactant in this manner, the affinity between the oxide film and the sealing agent becomes good, and the sealing with a metal salt such as titanium fluoride or titanium fluoride salt is performed smoothly.

Examples of the above-mentioned surfactants include fatty acid salts, alkyl sulfate salts, alkylbenzene sulfonates, polyoxyethylene alkyl sulfate ester acids, polyoxyethylene Rm acid esters, polyoxyethylene 7-rukyl esters, etc. Examples include nonionic surfactants such as ether and polyoxyethylene alkylphenol ether.

Next, the invention of claim 2 will be explained in detail.

In the sealing agent for aluminum-based metals having an oxide film according to claim 2, ``a mixture of titanium fluoride and/or titanium fluoride salt (A) and silcoium 77ide salt (B) is (A) 100 parts by weight. (B) in an amount of 10 to 400 parts by weight. That is, if zirconium fluoride salt is used alone, the above-mentioned disadvantages will occur, but by using titanium fluoride and/or a mixture of titanium fluoride and zirconium fluoride salt, for the reasons described below. A uniform and excellent sealing effect can be obtained.

That is, examples include mixtures of titanium fluoride and zirconium fluoride salts, mixtures of titanium fluoride salts and norconium 77ide salts, and mixtures of titanium fluoride, titanium fluoride salts, and zirconium fluoride salts. In this case, it is desirable that the mixture of titanium fluoride and/or titanium fluoride salt (A) and zirconium fluoride salt (B) be 10 to 400 parts by weight of (B) based on 100 parts by weight of (A). For 100 parts by weight of (A), (
If B) is less than 10 parts by weight, the synergistic effect of adding the zirconium fluoride salt will be poor, and there is no point in adding it. On the other hand, if (B) exceeds 40 parts by weight, the above-mentioned disadvantages will occur, that is, the zirconium fluoride salt will be added. This is not preferable because it may cause the same drawbacks as when using only salt.

This invention is characterized in that titanium fluoride and/or a mixture of titanium fluoride salt and zirconium fluoride salt is an essential component of the pore sealing agent, and the rest is claimed in claim 1.
This is the same as the pore sealing agent, so it will be omitted. Furthermore, the method for sealing an oxide film of an aluminum-based metal according to claim 3 will be explained in detail. In the method for sealing an oxide film of an aluminum-based metal according to claim 3, the oxide film of an aluminum-based metal is preliminarily prepared in an aqueous solution containing titanium 77ide, titanium fluoride salt, or a mixture of these salts and zirconium fluoride salt. After the sealing treatment, the main sealing is performed.

That is, in this invention, aluminum P. This article concerns a method for sealing a metal oxide film.

Therefore, the meaning of titanium fluoride, titanium fluoride salt, or a mixture of these salts and zorconium fluoride salt is the same as in the case of item a, and will therefore be omitted.

In the present invention, first, a first step is carried out in which the oxide film of the aluminum-based metal is subjected to a pre-air hole treatment using this sealing agent.

This oxide film also includes those colored with dyes or metal salts. To pre-seal the aluminum-based metal having this oxide film, the above-mentioned sealing agent is put into a treatment tank, and if desired, the concentration of metal salt such as titanium 77ide or titanium fluoride is reduced to 0.0 with water. 1-100g/1, especially 0.5-50g/1
or adjust the pH to a range of 3.5 to 6.0 with a pH adjuster.
llI in the range of 5, especially in the range of 4 to 6! ! ! The temperature of this treatment liquid is usually from room temperature to 50°C, preferably 2°C.
The temperature may be adjusted to 0 to 40°C, and the aluminum metal having an oxide film may be immersed for usually 30 seconds to 20 minutes, preferably 1 to 10 minutes.

In the present invention, next, a second step is performed in which the aluminum-based metal having the oxide film that has been preliminarily sealed in the first step is subjected to main sealing.

The method of this main hole sealing is not particularly limited.

For example, an aluminum-based metal having an oxide film that has been pre-IiIN holed in the first step is (a) immersed in hot water of 90°C or more for 5 minutes or more, or (b) immersed in water vapor of 2 kg/cm2 or more for 5 minutes. Examples of methods include the above-mentioned sealing treatment, and (iii) sealing treatment at 80° C. or higher for 5 minutes or more in an aqueous solution containing an M pore aid. In the present invention, the actual sealing requires a lower pressure of water vapor than the conventional method, and can be performed in an extremely short time. This is because the present invention performs pre-sealing. be.

Note that the sealing aid in (c) above is not particularly limited and any known one may be used, but specifically, for example, the product name is Sealing Sol}ASL, which is a nickel acetate-based sealing aid. (manufactured by Sandoz Co., Ltd.), 7-Co (manufactured by Furukawa Electric)
, Top Seal (manufactured by Okuno Pharmaceutical Co., Ltd.), etc. The concentration of the sealing aid is not particularly limited as long as the effect can be obtained, but it is generally 1 to 10 g/
1. In particular, it is desirable that the content be in the range of 4 to 7 g/l.By performing the sealing treatment in this way, corrosion resistance is excellent, and there is no bleeding of dyes, etc., or decolorization during the sealing treatment.
Furthermore, even if you touch it with your hands, dyes will not transfer to your hands, and an excellent sealing effect can be achieved. In other words, when an oxide film colored with a dye or the like is sealed using a normal sealing method, the dye, etc. leaks into the sealing solution during sealing, resulting in decolorization and thinning of the color. This may cause color unevenness and may be impractical. However, according to the pore sealing method of the present invention, such discoloration does not occur, corrosion resistance is excellent, and a uniform pore sealing effect can be obtained.

After this main pore-sealing treatment, a pore-sealing film with sufficiently satisfactory corrosion resistance can be obtained by appropriately washing with water and drying.

Next, the invention of claim 4 will be explained in detail.

In the method for sealing an oxide film of an aluminum-based metal according to claim 4, the oxide film of an aluminum-based metal is subjected to the same sealing treatment as in claim 3 using the sealing agent of claim 2. It is about.

Therefore, a detailed explanation of the sealing agent used in this sealing method and the sealing method will be omitted.

That is, in the method for sealing an oxide film of an aluminum-based metal according to claim 4, the mixture of titanium fluoride and/or titanium fluoride salt (A) and zirconium fluoride salt (B) is 100 parts by weight of (A). The sealing agent is used in an amount of 10 to 400 parts by weight based on (B), and the sealing treatment is performed in the same manner as in claim 3.

By using a mixture of titanium fluoride and/or titanium fluoride salt and zorconium fluoride salt in this way, the synergistic effect of the two allows for extremely excellent corrosion resistance to be achieved evenly over one meter, and an excellent sealing effect. is obtained.

(e) Effect In the present invention, when titanium fluoride, a titanium fluoride salt, or a mixture of at least one of these salts and a zirconium fluoride salt is used, sufficient corrosion resistance is imparted. The particle size of the hydrolyzate from the metal salt is smaller than the particle size of the hydrolyzate from the zirconium fluoride salt, and therefore the hydrolyzate smoothly penetrates into the oxide film, which causes fine particles in the oxide film to form. It is understood that this is to ensure that the hole is closed.

In addition, in the method of the present invention, even if the pre-sealing treatment is performed at a high temperature, there is no problem that the treated film reflects light and exhibits a rainbow color, but if the pre-sealing treatment is performed at a high temperature, the colored oxide film may be decolored. However, pre-sealing is performed at a relatively low temperature, which prevents discoloration, while the main sealing seals the pores completely, making it possible to seal the pores uniformly and reliably.As a result, the oxide film is It has the effect of extremely excellent corrosion resistance.

By the way, in the present invention, even better corrosion resistance can be obtained by using titanium fluoride and/or a mixture of titanium fluoride salt and zirconium fluoride salt, but this is because the hydrolyzate from each metal salt is uniformly distributed. becomes a mixed state,
The repulsion between particles is eliminated, and as a result, the hydrolyzate becomes a
It is understood that this is because the particles become easier to swallow and their particle size becomes smaller, making it easier for them to penetrate into the micropores of the oxide film.

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

Example 1 An aluminum plate (AI 050P-82 4 material, dimensions 50 mm x 100 mm x 1 am) was degreased with alkaline and washed with acid according to a conventional method. This is 1 8
An anodic oxide film (thickness: 12 μIII) was formed by electrolyzing for 25 minutes in an aqueous solution containing 0 g/lH 2 SO at a temperature of 20° C. and a current density of 1.5 A/dm.

After washing with water, it was added to an aqueous solution of 5 g/l of titanium fluoride and 2 g/l of sodium dodenlebenzenesulfonate at 30°C.
The holes were preliminarily sealed by immersion for 0 minutes. Next, after washing it with water,
The pores were immersed in a 5 g/ffi aqueous solution of sealing salt ASL-New (trade name, manufactured by Sandoz Co., Ltd.), which is a pore-sealing agent, at a temperature of 9.degree. Next, convert this to JIS
Corrosion resistance testing by alkaline drop test was carried out according to H 8601.

The result was 105 seconds.

Example 2 Aluminum plate (A60635-T5 material, dimension 50m
The anodic oxide film i (thickness: 9 μm) was formed by electrolysis for 20 minutes in the same manner as in Example 1. After washing with water, this was pre-sealed by immersing it in an aqueous solution of sodium hexa7fluorotitanate (IV) Sg/1 and sodium dodecylbenzenesulfonate 1 g/1 at 40° C. for 3 minutes. Next, after washing it with water, it was placed in hot water at a temperature of 90°C.
The hole was finally sealed by immersion at 5°C for 5 minutes.

Next, this was subjected to a corrosion resistance test using an alkali dropping test according to JIS H 8601.

The result was 125 seconds.

Example 3 Aluminum plate (A60635-T5 material, size 50II
I + 1 x 100 I
) was admonished. This is A Iua + iniun B l
It was immersed in an aqueous solution of 3 g/f of ue 2 LW (blue dye manufactured by Sandoz Co., Ltd.) at a temperature of 50° C. for 5 minutes to obtain a blue oxide film.

After washing this with water, 5g/1 sodium hexa7fluorotitanium (R') and hexa7fluorozirconium ('IY)
It was preliminarily sealed by immersing it in an aqueous solution of Wl sodium 2, Sg/1 at 20°C for 8 minutes. Next, after washing it with water, sealing sol which is a sealing agent} ASL-New (trade name manufactured by Sandoz Co., Ltd.) 5 g/j! It was immersed in an aqueous solution at a temperature of 90° C. for 5 minutes to perform main sealing.

Next, this was subjected to a corrosion resistance test using an alkali dropping test according to JIS H 8601.

The result was 250 seconds.

According to the method of the present invention, it is recognized that sufficiently satisfactory corrosion resistance can be obtained.

Further, the treated film obtained in this example did not exhibit any iridescent color even when exposed to light from various directions, and no sealing unevenness was observed at all. Note that even when the treatment temperature was 70° C., the treated surface did not exhibit rainbow color and there was no uneven sealing at all.

Furthermore, even when this material was touched with the hands, no dye was transferred to the hands.

Comparative Example 1 Aluminum plate (A 1 0 5 0P-82 4 material,
Using a size 50mm x 100mm x 1-1, this was electrolyzed for 20 minutes under the same conditions as in Example 1 to form an anodized film (
The thickness was 9 μm). Wash this with water, then (
N.H. )2Z rF. 30% in an aqueous solution (liquid temperature 30°C) containing 1g/l of
After soaking for a minute and sealing, it was dried.

Although the obtained treated film did not exhibit any iridescent color, it had problems such as fingerprint marks when touched by hand and difficulty in peeling off when a curing sheet was applied.

By the way, the above anodic oxide film was colored in the same manner as in Example 3, washed with water, and then coated with (NH.). 1g of ZrF6
An aqueous solution containing 0.25 g/l and anionic surfactant sodium polyoxyethylene lauryl sulfate (
After pore-sealing treatment by immersing it in a liquid temperature of 30° C. for 30 minutes, it was dried.

It was observed that when this material was touched with the hands, the dye was transferred to the hands.

Comparative Example 2 An aluminum plate (*same as that used in Example 2) was anodized in the same manner as in Example 2, and (NH.). ZrF
．． 1g/f (0.41g/f in terms of zirconium metal)
J! ) for 30 minutes at 70°C to seal the holes. Corrosion resistance was examined in the same manner as in Example 1 and was found to be approximately 90 seconds. This treated film exhibited a dark iridescent color when exposed to light from various directions, and its commercial value was low.

([1> Effects of the Invention Since the present invention is structured as described above, it produces the effects described below.

The pore sealing agent of the present invention uses titanium fluoride, a titanium fluoride salt, or a mixture of at least one of these salts and a zirconium fluoride salt, and the hydrolyzate from these salts is released into the oxide film. It penetrates smoothly into the oxide film and reliably closes the micropores in the oxide film, resulting in an excellent pore-sealing effect.

In addition, in the method of the present invention, even if the pre-sealing treatment is performed at a high temperature, there is no problem that the treated film reflects light and exhibits an iridescent color, but if the pre-sealing treatment is performed at a high temperature, the colored oxide film However, pre-sealing is performed at a relatively low temperature, which prevents discoloration, while main sealing completely seals the pores, making it possible to seal them uniformly and reliably. The corrosion resistance of the oxide film is extremely effective. By the way, in the present invention, when titanium fluoride and/or a mixture of titanium fluoride salt and zirconium fluoride salt is used, the hydrolyzates from each metal salt are uniformly mixed, and the repulsion between particles is eliminated. Since the particle size is further reduced, it is difficult for the particles to penetrate into the micropores of the oxide film by 1 N1.
As a result, excellent corrosion resistance can be obtained.

Claims (4)

[Claims] (1) A sealing agent for sealing an oxide film of an aluminum-based metal, the sealing agent comprising titanium fluoride, a titanium fluoride salt, or at least one of these salts and a zirconium fluoride salt. A pore sealing agent for aluminum-based metals having an oxide film made of an aqueous solution containing a mixture of. (2) Titanium fluoride and/or titanium fluoride salt (A
) and fluorinated zirconium salt (B) is (A) 10
The sealing agent for aluminum-based metals having an oxide film according to claim 1, wherein the amount of (B) is 10 to 400 parts by weight relative to 0 parts by weight. (3) Titanium fluoride, aluminum-based metal oxide film,
1. A method for sealing an oxide film of an aluminum-based metal, comprising performing preliminary sealing in an aqueous solution containing a titanium fluoride salt or a mixture of these salts and a zirconium fluoride salt. (4) Titanium fluoride and/or titanium fluoride salt (A
) and fluorinated zirconium salt (B) is (A) 10
4. The method for sealing an oxide film of an aluminum-based metal according to claim 3, wherein the amount of (B) is 10 to 400 parts by weight relative to 0 parts by weight.