JP6711525B2 - Sealing treatment liquid for anodic oxide coating of aluminum alloy, concentrated liquid and sealing treatment method - Google Patents

Description

The present invention relates to a sealing treatment solution for an anodized film of an aluminum alloy, a concentrated solution and a sealing treatment method.

The anodic oxide coating of an aluminum alloy is generally subjected to a sealing treatment in order to prevent stains and improve corrosion resistance. Known sealing methods include boiling water sealing, steam sealing, room temperature sealing, and nickel acetate sealing in which a sealing treatment is performed using a nickel acetate aqueous solution (see Non-Patent Document 1 below).

Among them, the corrosion resistance of the coating is more easily obtained than boiling water sealing, the work efficiency is superior to steam sealing, and the liquid management is easier than normal temperature sealing. Is especially used.

However, in recent years, nickel allergy and toxicity of fine powdery nickel salts have become a problem, so by using a sealing treatment method without using nickel salt, corrosion resistance and sealing degree similar to nickel acetate sealing can be obtained. It is desired to produce an anodic oxide coating having the sealing performance described above.

Light Metal Publishing Co., Ltd. Aluminum Surface Technology Handbook Metal salt sealing treatment section

The present invention has been made in view of the problems of the above-mentioned conventional techniques, and is a sealing treatment liquid that does not contain a nickel salt, and is approximately the same as when a sealing treatment liquid that contains a nickel salt is used. An object of the present invention is to provide a sealing treatment liquid capable of imparting sealing performance and capable of exhibiting excellent stain resistance of the sealed anodic oxide film.

The present inventor has conducted extensive studies to achieve the above object. As a result, a sealing treatment liquid for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant, wherein the metal salt is at least selected from alkali metal salts and alkaline earth metal salts. It was found that the above-mentioned object can be achieved by using one type of sealing treatment liquid, and the present invention has been completed.

That is, the present invention relates to a sealing treatment liquid for an anodized film of an aluminum alloy, a concentrate, and a sealing treatment method described below.
1. A sealing treatment liquid for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant,
The pore-sealing solution, wherein the metal salt is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts.
2. Item 2. The sealing treatment liquid according to Item 1, wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Na, Mg, K and Ca.
3. Item 2. The sealing treatment liquid according to Item 1, wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Mg and Ca.
4. Item 4. The sealing treatment liquid according to any one of Items 1 to 3, wherein the metal salt is at least one selected from the group consisting of acetate, sulfamate, sulfate and nitrate.
5. Item 4. The sealing treatment liquid according to any one of Items 1 to 3, wherein the metal salt is a nitrate.
6. Item 6. The pH buffer is at least one selected from the group consisting of organic acid salts, ammonium salts, amino acids, borate salts, amine compounds, and nitrogen-containing heterocyclic compounds, in any one of claim|item 1 -5. Sealing liquid for.
7. Item 6. The sealing treatment liquid according to any one of Items 1 to 5, wherein the pH buffer is a nitrogen-containing heterocyclic compound.
8. Item 8. The sealing treatment liquid according to any one of Items 1 to 7, wherein the surfactant is at least one selected from the group consisting of anionic surfactants and amphoteric surfactants.
9. Item 8. The surfactant according to any one of Items 1 to 7, wherein the surfactant is at least one selected from the group consisting of a sulfate-based surfactant, a sulfonate-based surfactant, and a phosphate ester-based surfactant. Sealing liquid for.
10. Item 10. The sealing treatment liquid according to any one of Items 1 to 9, which has a pH of 7.0 to 10.0.
11. Item 11. The pore-sealing treatment liquid according to any one of Items 1 to 10, which does not contain a nickel-based metal salt.
12. Item 12. The sealing treatment according to any one of Items 1 to 11, wherein the total content of the metal salt, the pH buffer and the surfactant in the sealing treatment liquid is 0.2 to 100 g/L. liquid.
13. A concentrated liquid of a sealing treatment liquid for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant,
The concentrated liquid, wherein the metal salt is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts.
14. A method for sealing an anodized film of an aluminum alloy,
In the sealing treatment liquid for anodized film of aluminum alloy, having a step of immersing an article having an anodized film of aluminum alloy,
The sealing treatment liquid contains a metal salt, a pH buffer and a surfactant,
The metal salt is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts,
A sealing treatment method characterized by the above.
15. Item 15. The sealing treatment method according to Item 14, wherein the sealing treatment liquid has a liquid temperature of 85 to 100°C.
16. Item 16. The sealing treatment method according to Item 14 or 15, wherein the sealing treatment liquid has a pH of 7.0 to 10.0.
17. An article which has been subjected to a pore-sealing treatment by the pore-sealing treatment method according to any one of Items 14 to 16.

According to the sealing treatment liquid of the present invention, to the anodized film of the aluminum alloy, it is possible to impart the same sealing performance as when using the sealing treatment liquid containing a nickel salt, and Excellent stain resistance can be imparted.

In addition, according to the concentrate of the present invention, the sealing treatment liquid for an anodized film of an aluminum alloy of the present invention can be easily prepared only by diluting the concentrate.

Further, according to the method for sealing a anodic oxide coating of an aluminum alloy of the present invention, the anodic oxide coating of an aluminum alloy has a sealing performance equivalent to that when a sealing treatment liquid containing a nickel salt is used. Can be imparted, and excellent stain resistance can be imparted.

Hereinafter, the present invention will be described in detail.

1. Sealing treatment liquid The sealing treatment liquid of the present invention is a sealing treatment liquid for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant, wherein the metal salt is an alkali metal salt or It is at least one selected from alkaline earth metal salts.

(Metal salt)
The metal salt contained in the sealing treatment liquid of the present invention is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts. The alkali metal salt or alkaline earth metal salt is not particularly limited, but water-soluble salts are preferable, and examples thereof include carboxylate, sulfamate, sulfate, nitrate, and organic sulfonate. Among these, carboxylate salt, sulfamate salt, sulfate salt, and nitrate salt are preferable in terms of excellent antifouling property of the anodized film of the aluminum alloy that has been subjected to the sealing treatment, and acetate salt, sulfamate salt, sulfate salt, and nitrate salt are preferable. Is more preferable, acetate and nitrate are more preferable, and nitrate is particularly preferable. The above metal salts may be used alone or in combination of two or more.

The metal contained in the metal salt is not particularly limited as long as it is an alkali metal and an alkaline earth metal, and specifically, Li, Be, Na, Mg, K, Ca, Rb, Sr, Cs, Ba, Fr and Ra can be used. Among these, metal salts of Na, Mg, K, and Ca are preferable, metal salts of Mg and Ca are more preferable, and metal of Mg is preferable because the anodized film of the sealed aluminum alloy has excellent stain resistance. More preferably, it is a salt. The metals contained in the above metal salts may be used alone or in combination of two or more.

The concentration of the metal salt in the sealing treatment liquid is not particularly limited and is preferably 0.001 to 1 mol/L, more preferably 0.01 to 0.5 mol/L. When the concentration of the metal salt is within the above range, the pore-sealing solution can exhibit sufficient pore-sealing performance, and the anodic oxide film of the aluminum alloy that has been pore-sealed by the pore-sealing solution has sufficient stain resistance. Can be shown in.

(PH buffer)
The pH buffer agent is not particularly limited, and a conventionally known pH buffer agent can be used. Examples of such pH buffering agents include organic acid salts, ammonium salts, amino acids, borates, amine compounds, nitrogen-containing heterocyclic compounds, and the like. Among these, nitrogen-containing heterocyclic compounds are preferable because they can impart excellent stain resistance to the anodized film of the aluminum alloy that has been subjected to the pore-sealing treatment with the pore-sealing liquid.

Examples of the organic acid salt include salts of carboxylic acid and oxycarboxylic acid. The carboxylic acid and oxycarboxylic acid preferably have 4 or less carbon atoms. In addition, examples of the salt include sodium salt and potassium salt.

Examples of the ammonium salt include ammonium salts of organic acids and ammonium salts of inorganic acids. Examples of ammonium salts of organic acids include ammonium salts of carboxylic acids and oxycarboxylic acids. The carboxylic acid and oxycarboxylic acid preferably have 4 or less carbon atoms. Examples of ammonium salts of inorganic acids include ammonium sulfate salts, ammonium nitrate salts, ammonium sulfamic acid salts, and the like.

Examples of amino acids include glycine, alanine, asparagine, and salts thereof. Examples of the borate include sodium borate, potassium borate, ammonium borate and the like. Examples of the amine compound include ethanolamine which is monoethanolamine, diethanolamine and triethanolamine, and also include alkylamine, aromatic amine, water-soluble carbonylamine such as urea and the like.

Examples of the nitrogen-containing heterocyclic compound include a heterocyclic compound containing at least one nitrogen atom as a hetero atom and a heterocyclic compound containing at least one nitrogen atom and at least one oxygen atom as a hetero atom.

The nitrogen-containing heterocyclic compound, ethyleneimine ring, azirine ring, azetidine ring, azeto ring, pyrrolidine ring, pyrrole ring, piperidine ring, pyridine ring, hexamethyleneimine ring, azatropylidene ring, imidazole ring, pyrazole ring, oxazole Examples of the nitrogen-containing heterocyclic compound include a ring, an imidazoline ring, a pyrazine ring, a morpholine ring, a pteridine ring, a purine ring and the like. Among these, a pyrrolidine ring, a pyrrole ring, a piperidine ring, a pyridine ring, a hexamethyleneimine ring, an azatropylidene ring, an imidazole ring, a pyrazole ring, an oxazole ring, an imidazoline ring, a pyrazine ring, a morpholine ring, a pteridine ring, a purine ring and the like are included. Nitrogen-containing heterocyclic compounds are preferred.

Examples of the nitrogen-containing heterocyclic compound include ethyleneimine, azirine, azetidine, azeto, pyrrolidine, pyrrole, piperidine, pyridine, hexamethyleneimine, azatropylidene, imidazole, pyrazole, oxazole, imidazoline, pyrazine, morpholine, pteridine, purine and the like. A compound in which an amino group or a methyl group is added to these skeletons can be used. Among these, a heterocyclic compound having a cyclic 5-membered to 7-membered ring, which has one or two nitrogen atoms as heteroatoms in the ring-constituting atoms and is composed of carbon or one heteroatom oxygen and carbon, and specifically, Examples thereof include compounds such as pyrrolidine, pyrrole, piperidine, pyridine, hexamethyleneimine, azatropylidene, imidazole, pyrazole, oxazole, imidazoline, pyrazine and morpholine, and compounds having a cyclic skeleton as a basic structure. Also preferred are compounds having a heavy polycyclic structure and having four or more heteroatom nitrogens, for example, compounds such as purines and pteridines, and compounds having a basic structure of its multiple cyclic skeleton. Of these, those having a 5- or 6-membered ring are more preferable, and examples thereof include compounds such as pyrrolidine, pyrrole, piperidine, pyridine, imidazole, pyrazole, oxazole, imidazoline, pyrazine, and morpholine, and compounds having a cyclic skeleton as a basic structure. Among these, compounds having a double bond in the ring such as pyrrole, pyridine, imidazole, pyrazole, oxazole, imidazoline, and pyrazine, and compounds having a cyclic skeleton as a basic structure are particularly preferable. Examples of the substituents constituting these compound groups include amino groups and methyl groups, and the compound groups to which these substituents are added may be used. For example, aminopyridines such as 2-aminopyridine and 4-aminopyridine, and methylimidazoles such as 2-methylimidazole are particularly preferable. Among them, pyridine, imidazole, aminopyridine, methylimidazole and the like are most preferable.

As the nitrogen-containing heterocyclic compound, pyridine; aminopyridine such as 2-aminopyridine and 4-aminopyridine; imidazole; methylimidazole such as 2-methylimidazole; pyrazole; pteridine; oxazole and the like are particularly preferable.

The above pH buffer agents can be used alone or in combination of two or more.

The concentration of the pH buffering agent in the sealing treatment liquid is not particularly limited and is preferably 0.1 to 100 g/L, more preferably 0.2 to 20 g/L. When the concentration of the pH buffer is within the above range, the sealing treatment liquid can exhibit excellent pH buffering property, and the appearance of the surface of the treated product is poor due to the too high concentration of the pH buffer. (Dry spots) and color loss of dyed products are suppressed.

(Surfactant)
The surfactant is not particularly limited, and a conventionally known surfactant can be used. Examples of such a surfactant include an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant.

As the anionic surfactant, a sulfate-based surfactant, a sulfonate-based surfactant, a phosphorus-based surfactant or the like can be used.

Examples of the sulfate-based surfactants include aromatic sulfate-based surfactants and aliphatic sulfate-based surfactants.

Examples of the aromatic sulfate-based surfactant include polyoxyethylene alkylphenyl ether sulfate. Further, examples of the aliphatic sulfate-based surfactant include polyoxyethylene alkyl ether sulfate.

Examples of the sulfonate-based surfactant include aromatic sulfonate-based surfactants.

Examples of the aromatic sulfonate surfactant include aromatic sulfonate compounds such as benzene sulfonate and naphthalene sulfonate, and aromatic sulfonate skeletons such as benzene sulfonate and naphthalene sulfonate. , Alkyl group, polyoxyethylene group, polyoxyethylene alkyl ether group, carboxyl group, carbonyl group, hydroxyl group, alcohol group, alkylene group such as vinyl group or allyl group, group having multiple bond, further sulfonic acid group substituted Examples thereof include compounds, and also include polycondensates of these compounds with formalin and the like, and copolymers. Examples of such aromatic sulfonate surfactants include alkylbenzene sulfonates, alkylnaphthalene sulfonates, their polycondensates such as formalin, formalin polycondensates of naphthalene sulfonates, and alkylenebenzene sulfonic acids. Examples thereof include copolymers from salts and alkylene naphthalene sulfonates.

Examples of the aromatic sulfonate-based surfactant also include compounds in which a plurality of phenyl sulfonates are ether-bonded, such as diphenyl ether disulfonate, and the compounds include an alkyl group and a polyoxyethylene group. , And compounds in which a polyoxyethylene alkyl ether group or the like is substituted. Examples of such aromatic sulfonate surfactants include alkyl diphenyl ether disulfonate and alkyl diphenyl ether disulfosuccinate.

As the phosphorus-based surfactant, a phosphoric acid ester-based surfactant, a phosphoric acid ester salt-based surfactant, or the like can be used. Specific examples include polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylated phenyl ether phosphates, alkyl phosphates and the like, and salts thereof.

As the nonionic surfactant, a nonionic surfactant which can adjust the concentration in the pore-sealing treatment liquid or can be combined with another surfactant to have a cloud point of 85° C. or higher in the pore-sealing treatment liquid. Can be preferably used. Examples of such nonionic surfactants include polyoxyethylene alkyl ether, glycerin ester polyoxyethylene ether, sorbitan ester, and fatty acid alkanolamide.

Examples of the amphoteric surfactant include alkyl betaine, fatty acid amide betaine, and alkylamine oxide.

As the above-mentioned surfactant, an anionic surfactant is preferable. Of these, sulfate-based surfactants, sulfonate-based surfactants and phosphorus-based surfactants are more preferred, and sulfonate-based surfactants are even more preferred.

The above surfactants may be used alone or in combination of two or more. The nonionic surfactant may be selected so that the clouding point of the sealing treatment liquid does not become low. When the nonionic surfactant and the anionic surfactant are mixed and used, the cloud point of the surfactant can be increased. When an anionic surfactant is used, it is sufficient to select one that does not cause turbidity by reacting with the contained metal or the amphoteric surfactant.

The concentration of the surfactant in the sealing treatment liquid is not particularly limited, preferably 10 mg/L to 10 g/L, more preferably 20 mg/L to 5 g/L. When the concentration of the surfactant is in the above range, the pore-sealing liquid can exhibit sufficient pore-sealing performance, and suppresses the powder blow and the fog appearance defect of the surface of the pore-treated anodic oxide film. can do.

(PH adjuster)
The sealing treatment liquid of the present invention may further contain a pH adjusting agent. The pH adjusting agent is not particularly limited, and a conventionally known pH adjusting agent can be used.

Examples of the pH adjuster for adjusting the sealing treatment liquid to the acidic side include dilute aqueous solutions of acetic acid, sulfamic acid, sulfuric acid, nitric acid, organic sulfonic acid and the like. Among these, nitric acid is preferable because of its excellent sealing performance.

Examples of the pH adjuster for adjusting the sealing treatment liquid to the alkaline side include ammonia water, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution and the like. Among these, an aqueous solution of sodium hydroxide is preferable because it has excellent sealing performance.

The above pH adjusters can be used alone or in combination of two or more.

The concentration of the pH adjuster in the sealing treatment liquid is not particularly limited and is preferably 0 to 20 g/L, more preferably 0 to 10 g/L, further preferably 0 to 5 g/L. When the concentration of the pH adjuster is within the above range, the pore-sealing solution can exhibit sufficient pore-sealing performance, and suppresses the reduction in the degree of sealing of the anodized film which has been pore-sealed by the pore-sealing solution. can do.

(Other ingredients)
The pore-sealing liquid of the present invention may contain an additive component such as an antifungal agent and a complexing agent, if necessary, in order to improve the pore-sealing performance and practical use of the liquid. Examples of the additives include antifungal agents such as benzoic acid and benzoate; complexing agents such as citric acid and citrate. Further, as the antifungal agent, a commercially available antifungal agent, for example, “TAC fungus colon” (manufactured by Okuno Chemical Industry Co., Ltd.) may be added.

(Sealing liquid)
The total content of the metal salt, the pH buffer and the surfactant in the sealing treatment liquid of the present invention is preferably 0.2 to 100 g/L, more preferably 0.3 to 50 g/L, and 0.5. -30 g/L is more preferable. When the total of the above contents is within the above range, the sealing treatment liquid can exhibit sufficient sealing performance, and the anodic oxide coating of the aluminum alloy sealed by the sealing treatment liquid is resistant to contamination. Can be sufficiently exhibited, and it is possible to suppress dusting of the surface of the anodized film subjected to the pore-sealing treatment and a defective fog appearance.

The pH of the pore-sealing treatment liquid is preferably 7.0 to 10.0, more preferably 7.2 to 9.5, and further preferably 7.5 to 9.0. When the pH is in the above range, the pore-sealing solution can exhibit sufficient pore-sealing performance, and the anodic oxide film of the aluminum alloy that has been pore-sealed with the pore-sealing solution exhibits sufficient stain resistance. In addition, appearance defects (powder blowing, fog) in which powdery deposits adhere to the surface of the object to be processed are suppressed.

The sealing treatment solution of the present invention is not particularly limited as long as it contains a metal salt, a pH buffer and a surfactant, but is preferably an aqueous solution containing the above-mentioned components.

The sealing treatment liquid of the present invention preferably does not contain a metal salt such as a nickel-based metal salt. Examples of the metal salt include metal salts of Ni, Co, Fe, Cr and the like.

2. Concentrated Solution The concentrated solution of the present invention is a concentrated solution of a sealing treatment solution for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant, wherein the metal salt is an alkali metal salt or an alkali. It is at least one selected from earth metal salts. By using a concentrated solution having a high concentration of components contained in the sealing treatment solution, it is easy to carry and store, and the sealing treatment solution is easily prepared by diluting with a diluting solution such as water. You can Water is preferable as the diluent.

As the metal salt, pH buffer and surfactant contained in the concentrated liquid of the present invention, the same ones as those contained in the sealing treatment liquid can be used. The concentrated liquid of the present invention contains the same components as the sealing treatment liquid, but the contents of the components are different.

The total content of the metal salt, pH buffer and surfactant in the concentrated liquid is preferably 1 to 800 g/L, more preferably 1.5 to 400 g/L, further preferably 2.5 to 250 g/L. .. When the total content is within the above range, it is easy to carry and store, and the sealing treatment solution can be easily prepared by diluting with water or the like. Further, the total content of the metal salt, the pH buffer and the surfactant in the concentrated solution may be in the range of more than 100 g/L in terms of the distinction between the sealing treatment solution and the concentrated solution, It may be 150 g/L or more.

3. Sealing treatment method The sealing treatment method of the present invention is a sealing treatment method for an anodized film of an aluminum alloy, wherein the sealing treatment liquid for anodized film of an aluminum alloy has an anodized film of an aluminum alloy. And a step of immersing the article, wherein the sealing treatment liquid contains a metal salt, a pH buffer and a surfactant, and the metal salt is at least one selected from alkali metal salts and alkaline earth metal salts. This is the seed sealing treatment method.

The sealing treatment liquid described above can be used as the sealing treatment liquid. The sealing treatment method of the present invention has a step of immersing an article having an anodized film of an aluminum alloy in the sealing treatment liquid. The dipping method is not particularly limited, and dipping may be performed by a conventionally known method.

The temperature of the sealing treatment liquid in the above step is preferably 85 to 100°C, more preferably 88 to 98°C, and further preferably 90 to 98°C. By setting the temperature of the sealing treatment liquid in the above range, sufficient sealing performance can be exhibited.

The pH of the pore-sealing treatment liquid is preferably 7.0 to 10.0, more preferably 7.2 to 9.5, and further preferably 7.5 to 9.0. When the pH is in the above range, the pore-sealing treatment liquid can exhibit sufficient pore-sealing performance, and the appearance defect (powder blowing, fog) in which the powder-like deposit adheres to the surface of the object to be treated is suppressed. ..

The sealing treatment time can usually be determined by the film thickness of the anodized film to be treated. Specifically, it is preferable that the number obtained by multiplying the number (μm) indicating the film thickness by 0.1 to 10 is the sealing treatment time (minutes), and the number (μm) indicating the film thickness is The number obtained by multiplying 0.2 to 5 is more preferably the sealing treatment time (minutes), and the number obtained by multiplying the number (μm) indicating the film thickness by 0.5 to 4 is the sealing time. The treatment time (minute) is more preferable. For example, if the film thickness of the anodized film is 10 μm, it is more preferable that the immersion time be about 2 to 50 minutes by multiplying 10 by 0.2 to 5. By setting the sealing treatment time within the above range, the sealing treatment liquid can exhibit sufficient sealing performance, and the anodic oxide film of the aluminum alloy sealed by the sealing treatment liquid has sufficient contamination resistance. In addition, it is possible to suppress deterioration of the appearance of the object to be processed due to poor appearance such as powder blowing and fog.

In the above step, the article having the anodic oxide coating of the aluminum alloy may be immersed while stirring the sealing treatment liquid. As a stirring method, circulation stirring, air stirring, gas stirring, and rocking stirring are suitable. Of these, circulation stirring and gas stirring are preferable, and circulation stirring is more preferable. As the gas stirring, gas stirring using an inert gas such as nitrogen gas or argon gas is suitable. In the above step, when a sealing treatment liquid containing Mg salt, Ca salt, Sr salt, Ba salt, Ra salt as a metal salt and having a pH of 7 or more is used, the sealing treatment liquid absorbs carbon dioxide in the air. However, turbidity may occur. Therefore, as the stirring method, circulation stirring is preferable as described above, but if it is necessary to perform air stirring on equipment, it is preferable to perform gas stirring using the above-mentioned inert gas to prevent turbidity of the sealing treatment liquid. It is preferable because it can be suppressed.

The sealing treatment method of the present invention removes turbidity in the sealing treatment liquid during the step of immersing the article having the anodic oxide coating of the aluminum alloy in the sealing treatment liquid for the anodic oxide coating of the aluminum alloy described above. The turbidity removing process may be performed. Further, the turbidity removing treatment may be carried out during the steps other than the above steps, for example, while waiting for the article to be immersed in the anodic oxide film sealing treatment liquid or during the suspension of the line. By performing the turbidity removal treatment, it is possible to suppress the deterioration of the appearance of the anodized film due to the poor appearance such as powder blowing and fog caused by the turbidity.

The method for removing turbidity is not particularly limited, and a conventionally known removing method can be used. Examples of the removal method include filtration removal. Specifically, a part of the sealing treatment liquid is flowed from the sealing treatment tank to a spare tank such as a cushion tank which is a chemical replenishment addition dissolution tank, and the temperature of the sealing treatment liquid is preferably 50° C. or lower. Examples of the method include cooling and cooling, filtering through a filter, and returning to the tank in which the above-mentioned sealing treatment is performed, and circulating it. If the equipment does not have a cushion tank, it may be filtered and removed by simple filtration circulation.

In the sealing treatment method of the present invention, the object to be treated is an anodized film of aluminum alloy. The anodized film of the aluminum alloy is not particularly limited, and may be an anodized film of an aluminum alloy obtained by applying a known anodizing method using sulfuric acid, oxalic acid or the like to a general aluminum alloy. .. The aluminum alloy is not particularly limited, and various aluminum-based alloys can be the target of anodic oxidation. Specific examples of the aluminum alloy include wrought material alloys shown in JIS-A 1000s to 7000s specified in JIS, casting materials and die casting materials shown in each step of AC and ADC. Representative examples include various alloy groups mainly composed of aluminum.

As the anodizing method applied to the aluminum alloy, for example, an aqueous solution having a sulfuric acid concentration of about 100 g/L to 400 g/L is used, and the liquid temperature is about −10 to 30° C. and about 0.5 to 4 A/dm ^2. The method of performing electrolysis with the anode current density of 1 is mentioned.

Further, in the sealing treatment method of the present invention, an anodic oxide coating of an aluminum alloy that is electrolytically colored may be treated.

As an electrolytic coloring method, a known coloring technique can be adopted. For example, the anodized film can be colored by immersing it in an electrolytic coloring bath after performing anodization and performing secondary electrolysis. Examples of the electrolytic coloring bath include a nickel salt-boric acid bath and a nickel salt-tin salt-sulfuric acid bath.

Further, in the sealing treatment method of the present invention, an anodized film of an aluminum alloy, which is dyed with a dye, may be treated.

Examples of the dyeing method using a dye include a method of immersing the anodized film in a conventionally known aqueous dye solution. As such a dye, a dye commercially available as a dye for an aluminum alloy anodized film can be used, and examples thereof include an anionic dye. 10-70 degreeC is preferable and, as for the temperature of the said dye aqueous solution, 20-60 degreeC is more preferable. Further, the concentration of the dye in the dye aqueous solution and the immersion time may be appropriately set depending on the desired color tone of dyeing and color strength.

If the anodized film of an aluminum alloy is dyed with a dye, and if the sealing solution cannot impart dye fixability, a dye fixing treatment is performed after dyeing and before sealing. May be. The dye fixing treatment agent used in the dye fixing treatment is commercially available for the aluminum alloy anodized film dyeing step (for example, TAC Adhesive-2, TAC Sunblock 77-5C manufactured by Okuno Chemical Industries Co., Ltd., etc.). ) Can be used. Further, dye fixing property can be imparted to the sealing treatment liquid by adjusting the types and blending of the pH buffer and the surfactant in the sealing treatment liquid.

In the sealing treatment method of the present invention, the article having the anodized film of the aluminum alloy described above is used as the treatment object, and the treatment object may be immersed in the above-described sealing treatment liquid. Further, if necessary, the article having an anodized film of an aluminum alloy may be subjected to electrolytic coloring, dyeing, etc., and then sufficiently washed with water, and the article to be treated may be immersed in the above-described sealing treatment liquid. .. As a result, the sealing performance of the anodized film of the aluminum alloy to be treated can be greatly improved.

The present invention will be specifically described below with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Under the following manufacturing conditions, anodized aluminum alloy test pieces used in the following examples and comparative examples were prepared.

Preparation of anodized test piece A (without dyeing treatment and dye fixing treatment) An aluminum test piece (JIS A1050P plate material) was weakly alkaline degreasing liquid (Okuno Pharmaceutical Co., Ltd. Top Alclean 101 (trade name) 30 g/ It was degreased by immersing it in an L aqueous solution, a bath temperature: 60° C.) for 3 minutes. Then, it is washed with water and anodized in an anodic oxidation bath containing sulfuric acid as a main component (containing 180 g/L of free sulfuric acid and 8.0 g/L of dissolved aluminum) (bath temperature: 20±1° C., anodic current density: 1 A/dm). ² , electrolysis time: 30 minutes, film thickness: about 10 μm). The obtained anodized film was washed with water to obtain an anodized aluminum alloy test piece (hereinafter referred to as "anodized test piece A").

Preparation of anodized test piece B (with dyeing treatment and dye fixing treatment) An aluminum test piece (JIS A1050P plate material) was weakly alkaline degreasing liquid (Okuno Pharmaceutical Co., Ltd. Top Alclean 101 (trade name) 30 g/ It was degreased by immersing it in an L aqueous solution, a bath temperature: 60° C.) for 3 minutes. Then, it is washed with water and anodized in an anodic oxidation bath containing sulfuric acid as a main component (containing 180 g/L of free sulfuric acid and 8.0 g/L of dissolved aluminum) (bath temperature: 20±1° C., anodic current density: 1 A/dm). ² , electrolysis time: 30 minutes, film thickness: about 10 μm). The obtained anodized film was washed with water, immersed in an acid activation bath (bath temperature: room temperature) containing 98% sulfuric acid 100 mL/L for 1 minute for acid activation, and washed with water. Then, it was immersed in a dyeing treatment liquid (TAC dye TAC black 402 1 g/L manufactured by Okuno Chemical Industries Co., Ltd.) at 50° C. for 1 minute and washed with water to carry out dyeing treatment. Then, it was immersed in a dye-fixing treatment liquid (TAC Adhesive-2 (trade name) 20 mL/L manufactured by Okuno Chemical Industries Co., Ltd.) at room temperature for 3 minutes and washed with water to perform dye-fixing treatment, and then dyed. An anodized aluminum alloy test piece (hereinafter referred to as "anodized test piece B") was obtained.

Preparation of anodized test piece C (with dyeing treatment, without dyeing and fixing treatment) An aluminum test piece (JIS A1050P plate material) was weakly alkaline degreasing solution (Okuno Pharmaceutical Co., Ltd. Top Alclean 101 (trade name) 30 g /L aqueous solution, bath temperature: 60° C.) for 3 minutes for degreasing. Then, it is washed with water and anodized in an anodic oxidation bath containing sulfuric acid as a main component (containing 180 g/L of free sulfuric acid and 8.0 g/L of dissolved aluminum) (bath temperature: 20±1° C., anodic current density: 1 A/dm). ² , electrolysis time: 30 minutes, film thickness: about 10 μm). The obtained anodized film was washed with water, immersed in an acid activation bath (bath temperature: room temperature) containing 98% sulfuric acid 100 mL/L for 1 minute for acid activation, and washed with water. Then, it is immersed in a dyeing treatment liquid (TAC dye TAC black 402 1 g/L manufactured by Okuno Chemical Industries Co., Ltd.) at 50° C. for 1 minute, and washed with water to give a dyeing treatment, and then subjected to a dyeing treatment and anodization. The obtained aluminum alloy test piece (hereinafter referred to as "anodized test piece C") was obtained.

(Example 1)
The anodized test piece A produced according to the above production conditions was treated with sodium acetate 1 g/L as a metal salt, ammonium acetate 1 g/L as a pH buffer, and sodium naphthalenesulfonate formalin polycondensate 0.5 g/L as a surfactant. For 5 minutes at each pH in a sealing treatment solution (bath temperature: 92° C.) that is an aqueous solution containing nitric acid and aqueous ammonia and adjusted to pH 7.0, 8.0, 9.0. The sealing treatment was performed by immersing for 10 minutes and 20 minutes respectively.

(Example 2)
The sealing treatment was performed in the same manner as in Example 1 except that the anodized test piece B was used.

(Example 3)
It contained 5 g/L of magnesium acetate as a metal salt, 0.5 g/L of triethanolamine as a pH buffer, and 0.2 g/L of sodium dodecylbenzenesulfonate as a surfactant, and the pH was adjusted with acetic acid and sodium hydroxide. The sealing treatment was performed in the same manner as in Example 1 except that the sealing treatment liquid that was an aqueous solution was used.

(Example 4)
An aqueous solution containing 5 g/L of calcium nitrate as a metal salt, 4 g/L of alanine as a pH buffer, and 0.2 g/L of sodium alkylenephenylsulfonate copolymer as a surfactant, the pH of which is adjusted with nitric acid and ammonia water. The sealing treatment was carried out in the same manner as in Example 1 except that a certain sealing treatment liquid was used.

(Example 5)
An aqueous solution containing 10 g/L of magnesium nitrate as a metal salt, 4 g/L of pyridine as a pH buffer, and 0.5 g/L of sodium formalin naphthalenesulfonate as a polycondensate as a surfactant, the pH of which was adjusted with nitric acid and potassium hydroxide. The sealing treatment was carried out in the same manner as in Example 1 except that the sealing treatment liquid was used.

(Example 6)
Using anodized test piece B, containing 10 g/L of magnesium nitrate as a metal salt, 4 g/L of pyridine as a pH buffer, 0.5 g/L of sodium formalin naphthalene sulfonate polycondensate, and using nitric acid and potassium hydroxide. The pore-sealing treatment was carried out in the same manner as in Example 1 except that the pore-sealing treatment liquid, which was an aqueous solution whose pH was adjusted, was used.

(Example 7)
The anodized test piece A produced according to the above production conditions was treated with 10 g/L of potassium nitrate as a metal salt, 0.5 g/L of 2-aminopyridine and 0.5 g/L of 2-methylimidazole as a pH buffer, and as a surfactant. A sealing treatment solution (bath temperature: 92) containing 0.2 g/L of polyoxyethylene styrenated phenyl ether phosphate and adjusted to pH 7.5 and 9.5 with nitric acid and ammonia water, respectively. (°C) for each pH for 5 minutes and 20 minutes for each immersion time to perform the sealing treatment.

(Example 8)
20 g/L of magnesium nitrate as a metal salt, 0.5 g/L of 2-aminopyridine and 0.5 g/L of 2-methylimidazole as a pH buffer, and 0.2 g of polyoxyethylene styrenated phenyl ether phosphate as a surfactant. The pore-sealing treatment was carried out in the same manner as in Example 7 except that the pore-sealing treatment liquid containing /L and having its pH adjusted with nitric acid and aqueous ammonia was used.

(Example 9)
Using anodized test piece B, barium nitrate 1 g/L as a metal salt, pyrazole 1 g/L and pteridine 1 g/L as a pH buffer, fatty acid amide alkyl betaine 1 g/L as a surfactant and sodium alkylenephenyl sulfonate The sealing treatment was performed in the same manner as in Example 7 except that the sealing treatment liquid containing 0.2 g/L of the polymer and having its pH adjusted with nitric acid and aqueous ammonia was used.

(Example 10)
Using anodized test piece A, magnesium nitrate 20 g/L as a metal salt, imidazole 2 g/L as a pH buffer, sodium polyoxyethylene alkyl ether sulfate 0.1 g/L and polyoxyethylene phenyl ether sulfate as a surfactant. The sealing treatment was carried out in the same manner as in Example 7 except that the sealing treatment liquid containing 0.2 g/L of sodium and having its pH adjusted with nitric acid and aqueous ammonia was used.
(Example 11)
Using anodized test piece A, magnesium nitrate 20 g/L as a metal salt, imidazole 2 g/L as a pH buffer, polyoxyethylene alkyl ether 0.01 g/L as a surfactant and sodium alkylenephenyl sulfonate copolymer The sealing treatment was carried out in the same manner as in Example 7 except that the sealing treatment liquid containing 0.2 g/L and adjusted in pH with nitric acid and aqueous ammonia was used.

(Example 12)
Using anodized test piece B, 5 g/L of calcium nitrate as a metal salt, 1 g/L of oxazole as a pH buffer, 0.2 g/L of fatty acid amide alkyl betaine as a surfactant and 0.5 g/sodium dodecylbenzenesulfonate. The sealing treatment was performed in the same manner as in Example 7 except that the sealing treatment liquid containing L and adjusted in pH with nitric acid and aqueous ammonia was used.

(Comparative Example 1)
The anodized test piece A was immersed in boiling water sealing (ion-exchanged water) at 92° C. for 20 minutes for sealing treatment.

(Comparative example 2)
The anodized test piece A was filled with a nickel acetate-based sealing agent (top seal H-298 (trade name) manufactured by Okuno Chemical Industries Co., Ltd.) (40 mL/L) at a pH of 5.6 as a sealing treatment solution (bath). It was immersed in a temperature of 92° C.) for 5 minutes, 10 minutes and 20 minutes for each sealing treatment.

(Comparative example 3)
The sealing treatment was performed in the same manner as Comparative Example 2 except that the anodized test piece C was used.

(Comparative example 4)
10 g/L ammonium sulfate, 0.5 g/L 2-aminopyridine and 0.5 g/L 2-methylimidazole as a pH buffer, and 0.2 g/L polyoxyethylene styrenated phenyl ether phosphate ester as a surfactant Then, the pore-sealing treatment was performed in the same manner as in Example 7 except that the pore-sealing treatment liquid that was an aqueous solution of which pH was adjusted with nitric acid and ammonia water was used.

Immediately after performing the sealing treatment on the anodized test pieces in the above-mentioned Examples and Comparative Examples, they were washed with running water for 1 minute. Next, the anodized test piece was dried with a dryer, and then left overnight at room temperature environment to prepare anodized test piece after the sealing treatment.

The anodized test pieces after the sealing treatment prepared in the above Examples and Comparative Examples were evaluated by the following test methods.

Sealing degree According to JIS H 8683-2:1999 (Testing method for sealing degree of anodic oxide film of aluminum and aluminum alloy Part 2: Phosphoric acid-chromic acid aqueous solution immersion test), each test after sealing treatment The piece was immersed in a phosphoric acid-chromic acid aqueous solution, and the mass reduction of the test piece per unit area was measured. The smaller the value, the better the sealing degree.

Contamination resistance (magic test-adhesive stain removal test)
Each test piece after the sealing treatment was left at room temperature for 1 day, a mark was written on the surface with an oil-based black magic ink, and the test piece was allowed to stand for 30 seconds. Then, it was wiped off with a box tissue soaked with water or isopropyl alcohol, and evaluated according to the following evaluation criteria.
◎: Marks can be completely removed by light rubbing ○: Marks can be removed by rubbing strongly △: Some mark marks remain even if strongly rubbed ×: Black color of the mark cannot be removed In addition, △ evaluation by water test If so, it can be evaluated that there is no problem in actual use.

Appearance Evaluation The surface of the anodized test piece subjected to the sealing treatment was visually observed for dusting, fog, or the generation state of an interference film rainbow caused by them, and evaluated according to the following evaluation criteria.
⊚: Powder dust, fog, or interference film rainbow due to them is not generated at all, and appearance is good. ○: Powder dust, fog, or interference film rainbow due to them is slightly generated, but there is a problem in appearance. No: △: Blowing of powder, fog, or interference film rainbow due to them, and slight appearance defect occurred ×: Powder blowing, fog, or interference film rainbow due to them was strongly generated And has a severe appearance defect

The results are shown in Tables 1-5.

As is clear from Tables 1 to 5, when the sealing treatment liquids of Examples 1 to 12 were used, even if the sealing treatment liquid did not contain the nickel salt, the sealing treatment liquid containing the nickel salt was used. It was found that the same level of sealing performance as that of the case can be provided. Further, it was found that when the sealing treatment liquids of Examples 1 to 12 were used, the sealing-treated anodic oxide film could exhibit excellent stain resistance.

(Example 13)
Anodized test piece A contains 10 g/L of magnesium nitrate as a metal salt, 4 g/L of pyridine as a pH buffer, 0.5 g/L of sodium naphthalenesulfonate formalin polycondensate as a surfactant, and nitric acid and water. The pore-sealing treatment was performed by immersing in 1 L of the pore-sealing treatment solution (bath temperature: 92° C.), which was an aqueous solution whose pH was adjusted to 9.0 with potassium oxide. Specifically, each of the 20 test pieces was sequentially immersed for 20 minutes while stirring the sealing solution with argon gas. The test piece had a size of 5 cm×10 cm, and the total area of both surfaces was 1 dm ² .

(Example 14)
The sealing treatment was performed in the same manner as in Example 13 except that air stirring was performed instead of argon gas stirring.

In Example 14, the pore-sealing bath was thickly turbid due to air agitation, but in Example 13 in which the argon gas was stirred, the pore-sealing bath was slightly turbid. The white turbid substances of Examples 13 and 14 could be removed by filtration.

Claims (10)

A sealing treatment liquid for an anodized film of an aluminum alloy containing a metal salt, a pH buffer and a surfactant,
The metal salt is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts,
The pH buffering agent, Ri nitrogen-containing heterocyclic compound der,
The surfactant is at least one selected from the group consisting of anionic surfactants and amphoteric surfactants,
The pH of the sealing treatment liquid is 7.0 to 10.0,
The sealing treatment liquid does not contain nickel salt,
A sealing treatment liquid characterized by the following. The sealing treatment liquid according to claim 1, wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Na, Mg, K, and Ca. The pore-sealing treatment liquid according to claim 1, wherein the metal salt is a metal salt of at least one metal selected from the group consisting of Mg and Ca. The sealing treatment liquid according to claim 1, wherein the metal salt is at least one selected from the group consisting of acetate, sulfamate, sulfate and nitrate. The sealing treatment liquid according to claim 1, wherein the metal salt is a nitrate. The surfactant is at least one selected from the group consisting of a sulfate-based surfactant, a sulfonate-based surfactant, and a phosphate ester-based surfactant, according to any one of claims 1 to 5. Sealing treatment liquid described. It does not contain nickel metal salt, sealing treatment solution according to any one of claims 1-6. The sealing according to any one of claims 1 to 8 , wherein the total content of the metal salt, the pH buffer and the surfactant in the sealing treatment liquid is 0.2 to 100 g/L. Processing liquid. A method for sealing an anodized film of an aluminum alloy, comprising:
In the sealing treatment liquid for anodized film of aluminum alloy, having a step of immersing an article having an anodized film of aluminum alloy,
The sealing treatment liquid contains a metal salt, a pH buffer and a surfactant,
The metal salt is at least one selected from the group consisting of alkali metal salts and alkaline earth metal salts,
The pH buffering agent, Ri nitrogen-containing heterocyclic compound der,
The surfactant is at least one selected from the group consisting of anionic surfactants and amphoteric surfactants,
The pH of the sealing treatment liquid is 7.0 to 10.0,
The sealing treatment liquid does not contain nickel salt,
A sealing treatment method characterized by the above. The sealing treatment method according to claim 9 , wherein a liquid temperature of the sealing treatment liquid is 85 to 100°C.