JP2015004083A - Sealing liquid for anodic oxidation film of aluminum alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide novel sealing liquid for an anodic oxidation film of aluminum alloy, which does not contain nickel salt, which is capable of imparting approximately the same level of dye fixation as the case of using sealing liquid containing nickel salt without impairing external appearance of the anodic oxidation film of aluminum alloy, furthermore imparting approximately the same level of corrosion resistivity and sealing performance such as sealing level, and performing sealing relatively at low temperature comparing to the case of performing nickel acetate sealing, and to provide a sealing method for anodic oxidation film of aluminum alloy.SOLUTION: Sealing liquid for an anodic oxidation film of aluminum alloy consists of aqueous solution containing water-soluble divalent manganese salt and at least one type of anionic surfactant selected from the group consisting of sulfonate type anionic surfactant and sulfate ester salt type anionic surfactant. In a sealing method for an anodic oxidation film of aluminum alloy, an article having the anodic oxidation film of aluminum alloy is immersed in the sealing liquid.

Description

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

  The anodized film of an aluminum alloy is generally subjected to a sealing treatment in order to prevent contamination and improve corrosion resistance. Known sealing methods include boiling water sealing, water vapor sealing, room temperature sealing, nickel acetate sealing that performs sealing using a nickel acetate aqueous solution (see Non-Patent Document 1 below).

  In addition, the anodic oxide film may be dyed to enhance decorativeness. When sealing the stained anodic oxide film, boiling water sealing or water vapor sealing causes severe color loss, and the film surface called fogging, dusting, rainbow, blooming, etc. is covered with a powdery layer. In the case of normal-temperature sealing, a large amount of dye transfer to the sealing treatment liquid (so-called “crying”) occurs and fogging is likely to occur. For this reason, as a sealing treatment method when dyeing is performed on the anodized film, nickel acetate sealing, which has a high fixing rate of the dye to the film and can easily obtain the corrosion resistance of the film as compared with the boiling water sealing, is particularly preferable. Many are used.

  However, since nickel allergy and toxicity of finely powdered nickel salts have become a problem in recent years, a dye fixing property and corrosion resistance comparable to those of nickel acetate sealed pores can be obtained by a sealing treatment method that does not use nickel salts. It is desired to produce a dyed product of an anodized film of an aluminum alloy.

  Nickel acetate sealing is usually performed using a high-temperature sealing bath of 90 ° C. or higher, and can be sealed at a relatively low temperature from the viewpoint of energy saving, safety against the high temperature of the sealing bath, and the like. A sealing treatment method is also desired.

  A sealing treatment method that does not use nickel salt has been proposed (see Patent Document 1, Patent Document 2, and the like below). Patent Documents 1 and 2 describe a sealing treatment method using a sealing treatment liquid containing an alkaline earth metal such as magnesium or calcium. However, in these sealing treatment methods, dye transfer to the sealing treatment liquid (crying out) is very large, and color omission, color change, color unevenness pattern, etc. are compared to those with nickel acetate sealing. There is a problem that only a lot can be obtained.

  In addition, there is room temperature sealing as sealing at relatively low temperatures, but room temperature sealing is performed using a nickel salt such as nickel fluoride, so it is not nickel-free sealing treatment, and dye-dyed products As described above, there is a problem that fogging is liable to occur in the case of sealing in the case.

JP 2000-511972 A JP-A-5-106087

Edition of light metal publishers Aluminum surface technical manual Metal salt sealing section

  The present invention has been made in view of the above-mentioned problems of the prior art, and its main purpose is a sealing treatment liquid containing no nickel salt, which impairs the appearance of an anodized film of an aluminum alloy. In addition, it is possible to impart the same degree of dye fixing ability as when a sealing solution containing nickel salt is used, and further to provide sealing performance such as corrosion resistance and sealing degree, and nickel acetate. It is an object of the present invention to provide a novel aluminum alloy anodic oxide film sealing treatment liquid and a sealing treatment method capable of carrying out a sealing treatment at a relatively low temperature as compared with the case of sealing.

  The present inventor has intensively studied to achieve the above-described object. As a result, the anodized film of the aluminum alloy is immersed in a sealing treatment solution containing a divalent manganese salt and a specific anionic surfactant, so that the sealing containing a nickel salt is performed without impairing the appearance of the coating. Compared with the case where nickel acetate sealing is performed, it is possible to provide the same degree of dye fixing ability as when using a processing solution, and further to provide sealing performance such as corrosion resistance and sealing degree. It has been found that the sealing treatment can be performed at a low temperature, and the present invention has been completed here.

That is, the present invention provides the following sealing treatment solution for an anodized film of an aluminum alloy and a sealing treatment method using the sealing treatment solution.
Item 1. From an aqueous solution containing at least one anionic surfactant selected from the group consisting of a water-soluble divalent manganese salt and a sulfonate anionic surfactant and a sulfate ester anionic surfactant A sealing solution for anodized film of an aluminum alloy.
Item 2. Item 2. The aluminum according to Item 1, which is an aqueous solution having a pH of 5.3 to 6.5 containing 0.1 to 300 g / L of a water-soluble divalent manganese salt and 0.05 to 40 g / L of an anionic surfactant. Sealing solution for anodized film of alloy.
Item 3. Item 3. The sealing solution for anodized film of aluminum alloy according to Item 1 or 2, wherein the manganese salt is at least one selected from the group consisting of manganese sulfate, manganese nitrate, manganese acetate, and manganese methanesulfonate.
Item 4. Item 4. A sealing treatment solution for an anodized film of an aluminum alloy according to any one of Items 1 to 3, wherein the manganese salt is manganese acetate.
Item 5. The above item wherein the anionic surfactant has an alkyl group, a phenyl group, an alkylphenyl group, a naphthyl group, an alkylnaphthyl group, or a group in which these groups are bonded to each other by an ether bond or an ester bond as a hydrophobic group. 5. A sealing treatment solution for an anodized film of an aluminum alloy according to any one of 1 to 4.
Item 6. The anionic surfactant is at least one selected from the group consisting of alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl diphenyl ether disulfonate, alkyl ether sulfate, and alkyl sulfate. A sealing treatment liquid for an anodized film of an aluminum alloy according to any one of Items 1 to 5.
Item 7. 7. An aluminum alloy anodic oxide coating, characterized by immersing an article having an anodic oxide coating of an aluminum alloy in the sealing solution for an anodic oxide coating of an aluminum alloy according to any one of the above items 1 to 6. Hole processing method.
Item 8. Item 8. The method for sealing an aluminum oxide anodic oxide film according to Item 7, wherein the temperature of the sealing solution is 65 to 95 ° C.
Item 9. An article having an anodized film of an aluminum alloy sealed by the method according to Item 7 or 8.

  Hereinafter, the present invention will be described in detail.

Sealing Treatment Liquid The sealing treatment liquid of the present invention is at least one selected from the group consisting of divalent manganese salts, sulfonate type anionic surfactants and sulfate ester type anionic surfactants. It consists of an aqueous solution containing an anionic surfactant.

  As the divalent manganese salt, any water-soluble salt can be used without particular limitation. As such divalent manganese salts, inorganic salts such as manganese sulfate and manganese nitrate, carboxylates such as manganese acetate, organic sulfonates such as manganese methanesulfonate, etc. are preferable, and manganese acetate having pH buffering properties. Is particularly preferred. These divalent manganese salts can be used singly or in combination of two or more.

  In the sealing treatment liquid of the present invention, if the concentration of the divalent manganese salt is too low, it is not preferable because sufficient contamination resistance, corrosion resistance, sealing degree, etc. cannot be obtained. On the other hand, when the concentration is too high, appearance defects such as fog are likely to occur, which is also not preferable. Therefore, from such a viewpoint, the concentration of the divalent manganese salt is preferably about 0.1 to 300 g / L, and more preferably about 1 to 150 g / L.

  The anionic surfactant is not particularly limited as long as it is a sulfonate anionic surfactant whose hydrophilic group is a sulfonate, or a sulfate ester type anionic surfactant whose hydrophilic group is a sulfate salt. Can be used. Examples of such anionic surfactants include sulfonate type anionic surfactants having an alkyl group, a phenyl group, an alkylphenyl group, a naphthyl group, an alkylnaphthyl group or the like as a hydrophobic group, and sulfuric acid having a similar hydrophobic group. Examples include ester salt type anionic surfactants. These hydrophobic groups may be bonded to each other through an ether bond or an ester bond.

  Such anionic surfactants include sulfonate type anionic surfactants such as alkyl sulfonates, alkyl benzene sulfonates, alkyl naphthalene sulfonates, and alkyl diphenyl ether disulfonates; alkyl ether sulfates. Sulfate ester type anionic surfactants such as salts and alkyl sulfate esters are preferred.

  Examples of the alkyl group contained in the alkyl sulfonate, alkyl ether sulfate, alkyl sulfate, etc. include linear or branched higher alkyl groups having about 6 to 30 carbon atoms. Specific examples of such higher alkyl groups include hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosanyl, triacontanil and the like.

  Examples of the alkyl group contained as a substituent in the alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkyl diphenyl ether disulfonate, etc. include linear or branched alkyl groups having about 1 to 20 carbon atoms. Specific examples of such alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, sec-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl. Pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosanyl and the like.

  The salt form is not particularly limited as long as it is a water-soluble salt, and examples thereof include alkali metal salts such as sodium salt and potassium salt, ammonium salt, and amine salt. These anionic surfactants can be used singly or in combination of two or more.

  In the sealing treatment liquid of the present invention, if the concentration of the anionic surfactant is too low, sufficient contamination resistance, corrosion resistance and sealing degree cannot be obtained, which is not preferable. On the other hand, when the concentration is too high, appearance defects such as spot-like unevenness tend to occur, which is also not preferable. Therefore, from such a viewpoint, the concentration of the anionic surfactant is preferably about 0.05 to 40 g / L, and more preferably about 0.2 to 20 g / L.

  The sealing solution of the present invention preferably has a pH in the range of about 5.3 to 6.5, and more preferably in the range of about 5.5 to 6.3. When the pH is within this range, the dye fixing property can be improved without impairing the appearance of the anodized film by performing the sealing treatment under the conditions described later, and further the corrosion resistance, the degree of sealing, etc. Sealing performance can be improved. On the other hand, if the pH is too low, sufficient contamination resistance, corrosion resistance, sealing degree, etc. cannot be obtained, which is not preferable. On the other hand, when the pH is too high, poor appearance such as fog is likely to occur, which is also not preferable. The pH of the sealing treatment liquid may be adjusted to be within the above pH range using, for example, an aqueous solution of acids such as acetic acid, nitric acid, sulfuric acid, or the like; an aqueous solution of weak alkalis such as aqueous ammonia, sodium acetate, or sodium carbonate. .

  In order to improve the sealing performance, the practical utility of the liquid, etc., the sealing treatment liquid of the present invention includes a pH buffer, a pH adjuster, a dispersant, a fungicide, a complexing agent, etc., as necessary. An additive component may be included. Examples of additives include pH buffers or pH adjusters such as acetic acid, acetate, nitric acid, nitrate, ammonia, and ammonium salts; sulfonic acid-based dispersants such as sodium salt of naphthalenesulfonic acid formalin condensate; benzoic acid, benzoic acid Antifungal agents such as acid salts; complexing agents such as citric acid and citrate.

Sealing treatment method In the sealing treatment method of the present invention, the object to be treated is an article having an anodized film of an aluminum alloy.

  The anodized film of the aluminum alloy to be processed 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 an object of anodization. Specific examples of aluminum alloys include JIS-A 1000 series to 7000 series wrought alloy alloys, cast materials, die casting materials, etc. Examples include various alloy groups mainly composed of aluminum.

As the anodic oxidation method applied to the aluminum alloy, for example, an aqueous solution having a sulfuric acid concentration of about 100 to 400 g / L is used, the liquid temperature is about 0 to 30 ° C., and an anodic current of about 0.5 to 4 A / dm ^2. A method of performing electrolysis at a density is mentioned.

  Moreover, in the sealing treatment method of the present invention, an anodic oxide film of an aluminum alloy that has been dyed or electrolytically colored may be treated.

  As the dyeing method, any method may be used as long as it is a dyeing method using a dye for dyeing an anodic oxide film of an aluminum alloy. For example, a method of immersing an anodized film of an aluminum alloy in an aqueous solution of a dye can be mentioned. As the dye, a general dye for dyeing an anodized film of an aluminum alloy can be used. Specific examples include chromium-containing azo-based, metal-free azo-based, metal-free xanthene-based, metal-free anthraquinone-based, copper phthalocyanine-based, iron-containing gold-containing azo-based dyes. These dyes can be used alone or in combination of two or more.

  As the electrolytic coloring method, a known coloring technique can be employed. For example, after anodizing, the anodized film can be colored by dipping in an electrolytic coloring bath 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.

  In the sealing treatment method of the present invention, an article having an anodized film of the above-described aluminum alloy may be used as an object to be processed, and the object to be processed may be immersed in the above-described sealing treatment liquid. In addition, if necessary, an article having an anodized film of an aluminum alloy may be dyed, electrolytically colored, etc., and then sufficiently washed with water, and the object to be processed may be immersed in the sealing treatment liquid described above. . Thereby, the dye fixing property of the anodized film of the aluminum alloy as the object to be processed can be improved, and the sealing performance such as the corrosion resistance and the sealing degree can be greatly improved.

  Further, in the sealing treatment method of the present invention, the sealing treatment can be performed at a relatively low temperature by using the above-described sealing treatment liquid as compared with the case of performing nickel acetate sealing. The sealing treatment temperature may be 90 ° C. or higher as in the case of nickel acetate sealing, and is preferably about 65 to 95 ° C. From the viewpoints of thermal energy reduction, work safety, sealing performance, etc., it is more preferably about 70 to 85 ° C.

  The sealing treatment time can usually be determined by the film thickness of the anodized film to be treated. When the treatment time is extremely short, sufficient improvement in corrosion resistance, sealing degree, contamination resistance, etc. is not recognized. Further, when the treatment time is extremely long, appearance defects such as fogging occur, and the appearance of the anodized film may be impaired, which is not preferable. For this reason, the sealing treatment time may normally be a sealing treatment time of about the number of film thickness (μm) × 1 to 5 minutes, and the sealing time of the film thickness (μm) number × about 1.5 to 3 minutes. The treatment time is preferred. For example, if the thickness of the anodized film is 10 μm, the immersion time is preferably about 15 to 30 minutes.

  The sealing treatment liquid of the present invention is a sealing treatment liquid containing a divalent manganese salt and a specific anionic surfactant that does not contain a nickel salt. It can provide the same degree of dye fixing ability as when using a salt-containing sealing treatment solution, and can also provide sealing performance such as corrosion resistance and sealing degree, as well as nickel acetate sealing. Compared to the case, the sealing treatment can be performed at a relatively low temperature.

  Therefore, by performing the sealing treatment using the sealing treatment liquid of the present invention, an anodized film of an aluminum alloy excellent in dye fixing property and sealing performance without using a sealing treatment liquid containing a nickel salt. Can be formed.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  According to the following production conditions, anodized and dyed aluminum alloy test pieces used in the following examples and comparative examples were produced.

Degrease by immersing a test piece of aluminum alloy (JIS A1100P plate) in a weak alkaline degreasing solution (Okuno Pharmaceutical Co., Ltd. Top Alclean 101 (trade name), 30 g / L aqueous solution, bath temperature: 60 ° C.) for 3 minutes. And washed with water and then anodized in an anodizing bath containing sulfuric acid as a main component (including free sulfuric acid 180 g / L and dissolved aluminum 8.0 g / L) (bath temperature: 20 ± 1 ° C., anode current density: 1 A / dm ² , electrolysis time: 30 minutes, film thickness: about 10 μm). The obtained anodic oxide 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 to activate the acid, and after washing with water, the following dye aqueous solution (bath temperature: 50 ° C.) And dyed for 5 minutes, and washed with water to obtain an anodized and dyed aluminum alloy test piece (hereinafter referred to as “anodized-dyed test piece”).

  Here, the dyes and their concentrations are 2 g / L and 10 g / L for TAC black 415 (chromium-containing azo), 2 g / L for TAC yellow 201 (chromium-containing azo), and TAC red 102 (chrome). 5g / L for metal-containing azo), 5g / L for TAC blue 502 (copper phthalocyanine), 2g / L for TAC yellow 4G (metal-free azo), TAC pink 139 (metal-free anthraquinone) ) Is 5 g / L, and TAC Brown RH (iron-containing azo-based) is 5 g / L. The above dyes are all TAC dyes manufactured by Okuno Pharmaceutical Co., Ltd.

Example 1
Each anodized-dyed test piece manufactured according to the above manufacturing conditions contains 30 g / L manganese acetate, 10 g / L 2-methyl-7-ethylundecane-4-sulfate sodium salt, and is adjusted to pH 5.9 with acetic acid. It was immersed for 20 minutes in a sealing treatment solution (bath temperature: 75 ° C.) made of the aqueous solution thus prepared for sealing treatment, and then washed with water and dried.

Example 2
Each anodized-dyed test piece produced according to the production conditions described above was sealed with an aqueous solution containing 30 g / L of manganese acetate and 5 g / L of sodium dodecyl diphenyl ether disulfonate and adjusted to pH 5.9 with acetic acid ( The bath was immersed in a bath temperature of 75 ° C. for 20 minutes for sealing treatment, and then washed with water and dried.

Comparative Example 1
Each anodic oxidation-dyed test piece produced according to the above production conditions was a pH 5.6 aqueous solution containing 40 mL / L of nickel acetate-based sealant (Top Seal H-298 (trade name) manufactured by Okuno Pharmaceutical Co., Ltd.). It was immersed for 10 minutes in a sealing treatment solution (bath temperature: 90 ° C.) for sealing treatment, and then washed with water and dried.

Comparative Example 2
Each anodized-dyed test piece produced according to the above production conditions was immersed in a sealing treatment solution consisting of boiling ion exchange water for 10 minutes for sealing treatment, and then washed with water and dried.

Comparative Example 3
Each anodized-dyed test piece produced according to the above production conditions is immersed in a sealing treatment solution (bath temperature: 75 ° C.) made of an aqueous solution containing 30 g / L of manganese acetate and adjusted to pH 5.9 with acetic acid for 20 minutes. Then, sealing treatment was performed, and then washing and drying were performed.

Comparative Example 4
Each anodized-dyed test piece produced according to the above production conditions was sealed with an aqueous solution containing 10 g / L of sodium 2-methyl-7-ethylundecane-4-sulfate and adjusted to pH 5.9 with acetic acid. It was immersed in a liquid (bath temperature: 75 ° C.) for 20 minutes for sealing treatment, and then washed with water and dried.

Comparative Example 5
Each anodized-dyed test piece produced according to the above production conditions was subjected to a sealing treatment solution (bath temperature: 75 ° C.) composed of an aqueous solution containing 5 g / L of sodium dodecyldiphenyl ether disulfonate and adjusted to pH 5.9 with acetic acid. It was immersed for 20 minutes for sealing treatment, and then washed with water and dried.

Test Example About the test piece obtained in the said Example 1, 2 and Comparative Examples 1-5, the following method performed the determination of the dyeing | staining degree, the corrosion resistance test, and the sealing degree test. The results are shown in Tables 1-3. In addition, the results of the corrosion resistance test and the sealing degree test were performed on a test piece dyed with black 415 (2 g / L).
1. Judgment of the degree of dyeing The degree of dyeing of the test piece sealed with nickel acetate of Comparative Example 1 was visually evaluated in 11 stages from “0” (no coloration) to “10” (dark coloration), with the color density standard “10”. evaluated. In addition, “fogging” was determined when the color was difficult to judge due to poor fog (referring to a state where the surface of the test piece was covered with a powdery layer).
2. Corrosion resistance test In accordance with JIS H 8681-1: 1999 (corrosion resistance test method for anodized films of aluminum and aluminum alloys, Part 1: Alkali resistance test-alkali dropping test), an aqueous sodium hydroxide solution was dropped on each test piece. The time until the anodized film of the aluminum alloy was melted was measured. The larger the number of seconds, the higher the corrosion resistance.
3. Sealing degree test Each test piece was phosphoric acid in accordance with JIS H 8683-2: 1999 (Method for testing the degree of sealing of anodized film of aluminum and aluminum alloy Part 2: Phosphoric acid-chromic acid aqueous solution immersion test) -It immersed in chromic acid aqueous solution, and the mass reduction | decrease of the test piece per unit area was measured. The smaller the numerical value, the better the sealing degree.

  As apparent from Tables 1 to 3, when the sealing treatment was performed using the sealing treatment liquid containing the divalent manganese salt of Examples 1 and 2 and the anionic surfactant, the acetic acid of Comparative Example 1 was used. Despite the sealing treatment performed at a relatively low temperature compared to the case where the sealing treatment was performed using a nickel-containing sealing treatment liquid, good dye fixing properties, corrosion resistance, and It was confirmed that the degree of sealing was shown.

Claims (9)

From an aqueous solution containing at least one anionic surfactant selected from the group consisting of a water-soluble divalent manganese salt and a sulfonate anionic surfactant and a sulfate ester anionic surfactant A sealing solution for anodized film of an aluminum alloy. The aluminum according to claim 1, which is an aqueous solution having a pH of 5.3 to 6.5 containing 0.1 to 300 g / L of a water-soluble divalent manganese salt and 0.05 to 40 g / L of an anionic surfactant. Sealing solution for anodized film of alloy. 3. The sealing solution for an anodized film of an aluminum alloy according to claim 1, wherein the manganese salt is at least one selected from the group consisting of manganese sulfate, manganese nitrate, manganese acetate, and manganese methanesulfonate. The manganese salt is manganese acetate, The sealing treatment solution for an anodized film of an aluminum alloy according to any one of claims 1 to 3. The anionic surfactant has an alkyl group, a phenyl group, an alkylphenyl group, a naphthyl group, an alkylnaphthyl group, or a group in which these groups are bonded to each other by an ether bond or an ester bond as a hydrophobic group. 5. A sealing treatment solution for an anodized film of an aluminum alloy according to any one of 1 to 4. The anionic surfactant is at least one selected from the group consisting of alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl diphenyl ether disulfonate, alkyl ether sulfate, and alkyl sulfate. A sealing treatment liquid for an anodized film of an aluminum alloy according to any one of claims 1 to 5. An article having an anodized film of an aluminum alloy is immersed in the sealing solution for anodized film of an aluminum alloy according to any one of claims 1 to 6, wherein the anodized film of the aluminum alloy is sealed Hole processing method. The method for sealing an aluminum oxide anodized film according to claim 7, wherein the temperature of the sealing treatment liquid is 65 to 95 ° C. An article having an anodized film of an aluminum alloy sealed by the method according to claim 7 or 8.