JP2003160897A - Method for sealing anodic oxide film of aluminum or aluminum alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a long-lasting sealing liquid which imparts satisfactory corrosion resistance to the anodic oxide film of aluminum, and does not cause powder generation on the surface of the sealed film. <P>SOLUTION: The sealing liquid for the anodic oxide film of aluminum or an aluminum alloy contains a nickel salt of organic acid and a high polymer expressed by general formula; (wherein, AO is an oxy alkylene with a carbon number of 2-10; m is 1-1,000; and n is 1-100). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sealing treatment liquid for an anodized film of aluminum or an aluminum alloy (hereinafter referred to as “aluminum”), and a method for sealing aluminum treatment using the sealing treatment liquid.

[0002]

2. Description of the Related Art Since the surface of anodized aluminum is a porous film having adsorptivity, it is easily polluted and has insufficient corrosion resistance. Conventionally, a sealing treatment has been carried out for the purpose of reducing the adsorptivity of such an oxide film, improving the corrosion resistance, and preventing the elution of adsorbed dye. Examples of the sealing treatment that has been industrially performed include pressurized steam treatment, boiling water (hot water) treatment, dichromate or chromate solution treatment, and nickel acetate treatment.

The pressurized steam treatment has excellent performance as compared with the sealing film obtained by other methods, but it requires a large amount of equipment cost and is not suitable for continuous treatment of building materials having a large shape. . The boiling water treatment is suitable for sealing large building materials because it is easy to operate and allows continuous treatment, but it does not have sufficient corrosion resistance, and the sealing treatment of colored aluminum anodic oxide coatings is not sufficient. However, there is a drawback that a large amount of dye is eluted. The dichromate or chromate solution treatment has a drawback that the sealing surface is yellowed, which may adversely affect the environment. Also, nickel acetate treatment
It is widely used for dye-colored products and electrolytically-colored products, but it has drawbacks such as turbidity and precipitates generated in the sealing bath and a large amount of dust wipes formed on the surface to be sealed.

The improved nickel acetate treatment method has been generally practiced as a method of remedying the drawbacks of these conventional treatment methods to some extent. This method uses a conventional nickel acetate bath,
For the purpose of preventing dusting, one type of surfactant having a dispersing or wetting action such as sulfosalicylate, naphthalenesulfonate formalin condensate, ligninsulfonate, nonylphenol ethers, and alkyltrimethylammonium chlorides or For the purpose of adding two or more kinds and further strengthening the buffering effect of the bath to stabilize the bath pH and prevent the formation of turbidity or precipitation, boric acid, acetic acid, succinic acid, benzoic acid, phthalic anhydride, tartaric acid, etc. This is a method of adding one or two kinds of acids or alkali salts thereof.

[0005]

However, in the above-mentioned improved nickel acetate method, turbidity and precipitation are hardly formed at the beginning of the bath, and dusting is hardly generated. However, the adhesion of the obtained sealing film to the paint is small. Is not enough,
When the sealing bath is used continuously for a long period of time, turbidity or precipitation occurs in the bath due to the reduced complexing ability, which gradually increases and eventually dusting occurs. Then, even after adding precipitates or cloudiness to the improved nickel acetate bath, it is difficult to prevent clouding or stains from occurring, even if supplementing with a dust-prevention agent or a buffer, the cloudiness or precipitates of the bath cannot be eliminated. is there. In this way, even with the improved nickel acetate method, it is not possible to prevent turbidity and precipitation of the bath from occurring at an early stage, so dust and dirt are generated, the film performance deteriorates, and the bath life is short. There were drawbacks such as having to do it.

The present invention has been made in view of the above problems, and an object thereof is to solve various drawbacks of the conventional method, to prolong the life of the sealing treatment liquid, and to make an anodized film of aluminum. To provide sufficient sealing corrosion resistance to the sealing film, and to provide a sealing solution which does not generate dust on the surface of the sealing film, and a method for sealing an anodized film of aluminum using the sealing solution. Is to provide.

[0007]

Means for Solving the Problems The inventors of the present invention have been investigating and researching a sealing treatment of an anodized film of aluminum, and as a sealing treatment liquid, a nickel salt of an organic acid as a main component, When using a liquid containing a polymer having a polyoxyalkylene group, an acid anhydride group and a styrylene group as a subcomponent, it is possible to impart sufficient corrosion resistance to the anodized film of aluminum, and, The present invention has been completed by finding that no dust is generated on the surface of the sealing film and that the life of the sealing treatment liquid is long.
Further, it has been found that when one kind or two or more kinds of surfactants are added to the sealing treatment liquid, the effect becomes more excellent.

1. The sealing treatment solution for an anodized aluminum film according to the present invention is characterized by containing a nickel salt of an organic acid and a polymer represented by the following general formula.

[Chemical 3] (In the formula, AO is an oxyalkylene group having 2 to 10 carbon atoms, m is 1 to 1000, and n is 1 to 100.)

2. The sealing treatment liquid for an anodized aluminum film according to the present invention is the same as the sealing treatment liquid according to 1 above, wherein the content of the nickel salt of an organic acid is 0.0001 to 1.
It is mol / l, and the content of the polymer represented by the above general formula is 0.000001 to 0.01 mol / l.

3. The sealing treatment liquid for an anodized aluminum film according to the present invention is characterized in that the sealing treatment liquid according to 1 or 2 above further contains one or more surfactants.

4. The method for sealing a anodic oxide coating of aluminum according to the present invention is a method for sealing a anodic oxide of aluminum or an aluminum alloy, and then containing a nickel salt of an organic acid and a polymer represented by the following general formula. It is characterized by being immersed in the treatment liquid.

[Chemical 4] (In the formula, AO is an oxyalkylene group having 2 to 10 carbon atoms, m is 1 to 1000, and n is 1 to 100.)

5. The sealing treatment method for an anodized aluminum film according to the present invention is the sealing treatment method according to 4 above, wherein the content of the nickel salt of the organic acid in the sealing treatment liquid is 0.0001 to 1 mol / 1, and the content of the polymer represented by the above general formula is 0.000001 to 0.
It is characterized by being 01 mol / l.

6. The sealing treatment method for an anodized aluminum film according to the present invention is the same as the sealing treatment method according to 4 or 5, wherein the sealing treatment liquid further contains one or more surfactants. It is characterized by being

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a sealing treatment liquid for an anodized aluminum film, which contains a nickel salt of an organic acid as a main component and has a polyoxyalkylene group, an acid anhydride group and a styrylene group in the molecule. It is characterized in that an aqueous solution containing a polymer as an auxiliary component and, if necessary, one or more kinds of surfactants added thereto is used.

The nickel salt of an organic acid used in the sealing solution of the present invention includes nickel salts of unsaturated carboxylic acids such as nickel acetate and nickel lactate, nickel malonate,
Nickel salts of saturated dicarboxylic acids such as nickel succinate, nickel adipate, nickel salts of unsaturated dicarboxylic acids such as nickel maleate, nickel fumarate, nickel malate, nickel tartrate, nickel citrate, nickel diglycolate, etc. Aromatic polybasic salts such as nickel salts of polybasic oxyacids, nickel phthalate, nickel trimellitate, nickel pyromellitic acid and the like can be mentioned. These nickel salts of organic acids may be used alone or in combination of two or more. Among these nickel salts of organic acids, nickel acetate, nickel malate and nickel succinate are preferable.

The content of the nickel salt of an organic acid in the sealing treatment liquid of the present invention is 0.0001 to 1 mol / l, preferably 0.001 to 0.1 mol / l. 0.0
When the amount is less than 001 mol / l, nickel is immediately consumed, which shortens the bath life and deteriorates the sealing degree. When it exceeds 1 mol / l, the nickel salt of the organic acid is not completely dissolved in the aqueous solution and the sealing treatment liquid becomes turbid, resulting in dusting of the sealing treatment surface.

These nickel salts of organic acids easily hydrolyze in the fine pores of the anodic oxide coating to form nickel hydroxide, and fill the fine pores to increase the corrosion resistance of the oxide coating. Also, due to the chelate-stabilizing effect, it acts to suppress the formation of a precipitate in the pore-sealing solution.

The "polymer having a polyoxyalkylene group, an acid anhydride group and a styrylene group in the molecule" used in the sealing treatment liquid of the present invention is a polymer represented by the following general formula, Alternatively, two or more kinds may be used in combination.

[Chemical 5] (In the formula, AO is an oxyalkylene group having 2 to 10 carbon atoms, m is 1 to 1000, and n is 1 to 100.)

Examples of the oxyalkylene group include ethylene oxide, propylene oxide and butylene oxide. Among them, ethylene oxide and propylene oside are preferable.

The content of the polymer represented by the above general formula in the sealing liquid of the present invention is 0.000001-.
0.01 mol / l, preferably 0.00001-
It is 0.001 mol / l. 0.000001 mol
If it is less than 1 / l, the ability as a surfactant is reduced and the dust-proofing effect is weakened. Also, 0.01mo
If it exceeds 1, the surface active agent is partially excessively adsorbed on the surface subjected to the pore-sealing and the appearance is deteriorated.

The polymer represented by the above general formula has a pore-sealing effect by itself, and when one or more other surfactants are used in combination, the polymer has a synergistic dispersion effect. It also has the effect of finishing the surface of the resulting oxide film more beautifully and also prolonging the life of the pore-sealing treatment liquid by virtue of its strong dispersing power and chelating action.

Surfactants that can be used in the sealing solution of the present invention include polyacrylic acid salts, salts of copolymers of vinyl compounds and maleic acid, alginates, polycarboxylic acid salts such as carboxymethyl cellulose. System: Polynaphthalates such as alkyl naphthalene sulfonate formalin condensate, naphthalene sulfonate formalin condensate, lignin sulfonate, petroleum sulfonate, melamine sulfonate formalin condensate; polyphosphoric acid such as hexametaphosphate Salt-based; nonionic polymers such as polyvinyl alcohol and water-soluble starch; cationic polymers such as polyacrylamide, cationic starch and polyethyleneamine. Among them, naphthalene sulfonate formalin condensate and lignin sulfonate are preferable. Further, these surfactants can be used alone or in combination of two or more. The content of these surfactants in the sealing treatment liquid of the present invention is 0.00000.
1-1 mol / l, preferably 0.00001-0.
It is 1 mol / l. The reason for using these surfactants is to promote the sealing effect and to improve the cleanability of the sealing surface.

Further, in the present invention, a buffering agent such as acetic acid, acetate, or ammonia water is used for the purpose of enhancing the buffering action of the sealing treatment liquid, and triethanol is used for the purpose of further promoting clarification of the sealing treatment liquid. A chelating agent such as amine, nitrilotriacetic acid trisalt, ethylenediaminetetraacetic acid disalt and the like, and one or more nickel salts such as nickel acetate, nickel gluconate, nickel glycolate, nickel sulfosalicylate and nickel sulfate for the purpose of supplementing nickel content. It is possible to add two or more kinds to the sealing treatment liquid.

[0024]

Next, examples of the present invention will be given together with comparative examples.
The present invention will be specifically described, but the present invention is not limited to the following examples.

[Example 1] In 500 ml of ion-exchanged water,
5 g of nickel acetate and a polymer having a polyoxyalkylene group, an acid anhydride group and a styrylene group in the above molecule (trade name: AKM-0531, manufactured by NOF Corporation) (hereinafter,
After adding 0.5 g of "PA"), ion-exchanged water was added to the aqueous solution obtained by stirring and mixing, and the whole was adjusted to 11 to obtain a sealing treatment liquid 1.

[Example 2] In 500 ml of deionized water,
After adding 5 g of nickel succinate and 0.6 g of PA, stir
Ion-exchanged water was added to the mixed aqueous solution to give a total of 11
Then, the sealing treatment liquid 2 was obtained.

[Example 3] In 500 ml of ion-exchanged water,
After adding 5 g of nickel acetate, 0.3 g of PA and 0.2 g of formalin condensate of alkylnaphthalene sulfonate, ion-exchanged water was added to the aqueous solution obtained by stirring and mixing, and the whole was 1
The sealing treatment liquid 3 was obtained by adjusting so as to be 1.

[Example 4] In 500 ml of ion-exchanged water,
After adding 6 g of nickel acetate, 0.5 g of PA, and 0.1 g of lignin sulfonate, ion-exchanged water was added to the aqueous solution obtained by stirring and mixing to adjust the total to 11, and then the sealing treatment liquid 4 Got

[Example 5] In 500 ml of ion-exchanged water,
After adding 5 g of nickel malate, 0.5 g of PA and 0.08 g of polyvinyl alcohol, ion-exchanged water was added to the aqueous solution obtained by stirring and mixing, and the whole solution was adjusted to 11 to prepare sealing treatment liquid 5. Obtained.

[Example 6] In 500 ml of ion-exchanged water,
After adding 6 g of nickel acetate, 0.4 g of PA, 0.15 g of formalin condensate of alkylnaphthalene sulfonate and 0.04 g of water-soluble starch, ion-exchanged water is added to the aqueous solution obtained by stirring and mixing, and the total becomes 11. The sealing treatment liquid 6 was thus obtained.

[Embodiment 7] In 500 ml of deionized water,
After adding 5 g of nickel acetate, 0.4 g of PA, 0.1 g of formalin condensate of naphthalene sulfonate, and 0.06 g of lignin sulfonate, ion-exchanged water was added to the aqueous solution obtained by stirring and mixing, and the total became 11. Thus, the sealing treatment liquid 7 was obtained.

[Embodiment 8] The liquid after the sealing treatment liquid 7 was subjected to the sealing treatment 50 times (the above-mentioned sealed specimen of 200 cm ² was treated 50 times, and 1 m ^{2 was} treated per 1 liter of the sealing treatment liquid. The liquid after being treated so as to correspond to this was used as the sealing treatment liquid 8.

Comparative Example 1 Boiling tap water was used as the sealing treatment liquid 9 (sealing treatment liquid used in the conventional boiling water method).

[Comparative Example 2] In 500 ml of deionized water,
After adding 6 g of nickel acetate, 8 g of boric acid, 8 g of sodium acetate and 0.5 g of acetic acid, ion-exchanged water was added to the aqueous solution obtained by stirring and mixing, and the whole solution was adjusted to 11,
A sealing treatment liquid 10 was obtained (the sealing treatment liquid used in the conventional nickel acetate method).

[Comparative Example 3] In 500 ml of deionized water,
After adding 6 g of nickel acetate and 0.9 g of naphthalene sulfonate formalin condensate, 1.5 g of phthalic anhydride, stirring
Ion-exchanged water was added to the mixed aqueous solution to give a total of 11
The sealing treatment liquid 11 was obtained (the sealing treatment liquid used in the conventional improved nickel acetate method).

[Comparative Example 4] Sealing treatment liquid 11 was subjected to 50 times of sealing treatment (50 cm ² of the sealed test piece was sealed).
The liquid after the treatment was repeated, and the treatment was performed so as to correspond to 1 m ² per 1 liter of the pore-sealing liquid).
It was set to 2.

<Preparation of Sealed Specimen> An aluminum specimen of JIS A 1100P subjected to usual degreasing and etching treatment was anodized in a 20% by weight sulfuric acid aqueous solution at 20 ° C. at a current density of 1 A / dm ² for 30 minutes. After doing, 30 ℃
AC electrolysis was performed in an aqueous solution of 100 g nickel sulfate + 30 g boric acid / L for 10 V for 5 minutes.

[Examples 9 to 16 and Comparative Examples 5 to 8] The sealed sample obtained as described above was used as the sealing treatment liquid of the present invention and the sealing treatment liquid of the comparative example. A sealing treatment was performed by immersing at 20 ° C. for 20 minutes. Acid resistance test (JIS H 8681-2), alkali resistance test (JIS H 8681-1), sealing degree test (J
ISH 8683-2), surface observation test (presence or absence of dust, dirt, rainbow, pit-like corrosion, etc.), life test of sealing solution (total alumite processing area amount), and evaluated according to the following evaluation criteria. The results are shown in Table 1.

<Acid resistance test> Using a Cass tester, an acetic acid acid salt aqueous solution containing a copper salt was sprayed on the sample for 8 hours, and the corrosion resistance of the film was examined according to the state of corrosion. The state in which the total corrosion area ratio was 0% was designated as a rating number 10, and the state of the sealed test piece after the 8-hour test was evaluated by the rating number and classified into the following five stages. Rating A: Rating number 9.5 or higher Rating B: Rating number 9.3 Rating C: Rating number 9 Rating D: Rating number 8 Rating E: Rating number 7 or less

<Alkali resistance test> An alkali dropping tester was used to drop an aqueous solution of sodium hydroxide on the test piece, and the time until the film was removed was measured to check the alkali resistance.
The larger the number of seconds, the better the sealing performance. The time until the film on the sealing test piece melted away was classified into the following five stages. Evaluation A: 130 seconds or more Evaluation B: 110 seconds or more and less than 130 seconds Evaluation C: 90 seconds or more and less than 110 seconds Evaluation D: 70 seconds or more and less than 90 seconds Evaluation E: less than 70 seconds

<Sealing Degree Test> By dipping the sealing test piece in an aqueous solution of phosphoric acid-chromic acid, the weight loss affected was measured, and the sealing degree was examined by the degree of acid resistance.
The smaller the mass reduction amount, the better the sealing performance. The mass reduction amount of the sealing test piece was classified into the following five stages. Evaluation A: 0.01 g / dm ^{2 or} less Evaluation B: 0.01 g / dm ² or more and less than 0.02 g / dm ² Evaluation C: 0.02 g / dm ² or more and less than 0.03 g / dm ² Evaluation D: 0.03 g / Dm ² or more and less than 0.05 g / dm ² Evaluation E: 0.05 g / dm ² or more

<Surface observation test> The surface of the sealing test piece is wiped with powder,
It was classified into the following five stages according to the state of dirt, rainbow, and pit-like corrosion. Evaluation A: Defects are not seen at all Evaluation B: Defects are hardly seen Evaluation C: Defects are slightly generated Evaluation D: Defects are generated in places Evaluation E: Defects are generated entirely

<Life Test> The total treated area of the test pieces after being immersed in the sealing treatment liquid at 92 ° C. for 20 minutes to perform the sealing treatment was classified into the following five stages. To determine the life of the sealing treatment liquid, the life was defined as the time when defects occurred locally (D) or less in the surface observation test. Evaluation A: 2.0 m ² / L or more Evaluation B: 1.5 m ² / L or more and less than 2.0 m ² / L Evaluation C: 1.0 m ² / L or more and less than 1.5 m ² / L Evaluation D: 0.5 m ² / L or more and less than 1.0 m ² / L Evaluation E: less than 0.5 m ² / L

[0044]

[Table 1]

[0045]

INDUSTRIAL APPLICABILITY As described in detail above, the present invention provides a sealing treatment for an anodized aluminum film using a sealing treatment liquid containing a nickel salt of an organic acid and the polymer represented by the above general formula. If you do, wipe the surface of the sealing
There is no rainbow or pit-like corrosion, and the sealing film performance such as acid resistance, alkali resistance, and sealing degree is excellent, and there is a remarkable effect that almost no turbidity or precipitate is generated in the sealing treatment liquid. Further, the sealing treatment liquid of the present invention has a long life, is inexpensive and can be easily used for sealing treatment, and therefore has an extremely high industrial value.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Haruo Usami             1-23-23, Uemachi, Chuo-ku, Osaka-shi, Osaka Prefecture             Nippon Chemical Industry Co., Ltd. Osaka Branch

Claims (4)

[Claims] 1. A sealing treatment solution for an anodized film of aluminum or an aluminum alloy, which contains a nickel salt of an organic acid and a polymer represented by the following general formula. [Chemical 1] (In the formula, AO is an oxyalkylene group having 2 to 10 carbon atoms, m is 1 to 1000, and n is 1 to 100.) 2. The sealing treatment liquid for an anodized film of aluminum or an aluminum alloy according to claim 1, further containing one or more kinds of surfactants. 3. An anodizing treatment of aluminum or an aluminum alloy, followed by immersion in a sealing treatment liquid containing a nickel salt of an organic acid and a polymer represented by the following general formula: A method for sealing an anodized film of aluminum or aluminum alloy. [Chemical 2] (In the formula, AO is an oxyalkylene group having 2 to 10 carbon atoms, m is 1 to 1000, and n is 1 to 100.) 4. The method for sealing an anodized film of aluminum or an aluminum alloy according to claim 3, wherein the sealing solution further contains one or more surfactants.