JPWO2019069920A1 - Chrome-free metal surface treatment agent - Google Patents

Abstract

A uniform coating film is formed on the surface of the metal material without uneven thickness while suppressing the blending of environmentally regulated components, making it possible to obtain a metal material with excellent appearance, and further, excellent corrosion resistance and paint adhesion on the surface of the metal material. Provided is a novel chrome-free metal surface treatment agent which can be imparted with water and effectively suppresses deterioration of corrosion resistance and paint adhesion due to water washing treatment. A chromium-free metal surface treatment agent containing the aqueous silane compound (A).

Description

The present invention relates to a chromium-free metal surface treatment agent and a metal surface treatment method using the same.

The surface of metal materials such as aluminum, zinc, magnesium, iron, copper, and alloys containing these is easily oxidized by atmospheric moisture, oxygen, chlorine ions, sulfate ions, etc., and the corrosive substances generated by the oxidation are metal materials. It is easy to spoil the appearance of.

Chromate treatment has been conventionally known as a method for suppressing corrosion on the surface of a metal material. In the chromate treatment, a reactive chromate treatment in which the surface of a metal material is brought into contact with a treatment liquid containing chromium such as chromic acid chromate and phosphoric acid chromate to form a chromate film is known.

The film formed by the chromate treatment has excellent corrosion resistance. However, since this treatment liquid contains hexavalent chromium having carcinogenicity, there is a big problem in the working environment for surface treatment. In addition, the cost of wastewater treatment is high. Furthermore, since the metal material surface-treated with the treatment liquid also contains hexavalent chromium, strict usage restrictions are currently imposed due to concerns about environmental pollution and adverse effects on the human body.

As an alternative to chromate treatment, various chromium-free metal surface treatment agents that impart excellent corrosion resistance to the surface of metal materials have been developed. As a chromium-free metal surface treatment, for example, a chemical conversion that forms a corrosion-resistant film with fluorides, phosphates, nitrates, sulfates, etc. of transition metals such as Mo, W, Ti, Zr, V, Mn, Co, and Fe. Treatment methods are known (see, for example, Patent Documents 1 and 2). However, although such a metal surface treatment method can improve the corrosion resistance of the metal material surface to some extent, the corrosion resistance is insufficient as compared with the chromate treatment.

As a metal surface treatment agent capable of imparting corrosion resistance comparable to that of chromate treatment to the surface of a metal material, for example, Patent Documents 3 and 4 contain an organic phosphonic acid polymer, an alkylphosphonic acid and a water-soluble complex fluoride. Chrome-free metal surface treatment agents for aluminum, aluminum alloys, zinc, and zinc alloys are disclosed. According to such a metal surface treatment agent, it is said that corrosion resistance equivalent to that of conventional chromate treatment can be imparted to the surface of a metal material without using chromium.

Japanese Unexamined Patent Publication No. 2003-155578 Japanese Unexamined Patent Publication No. 2004-18930 International Publication No. 2011/145594 Pamphlet Japanese Patent Application No. 2014-16599

As described above, according to the metal surface treatment agents disclosed in Patent Documents 3 and 4, it is possible to impart corrosion resistance equivalent to that of the conventional chromate treatment to the surface of the metal material without using chromium.

However, in recent years, environmental regulations have required new metal surface treatment agents that can reduce the emission of volatile organic compounds (VOCs). Alternatively, in order to preserve the water environment in closed water areas such as lakes and marshes, the Ministry of the Environment has established effluent standards for phosphorus content based on the Water Pollution Control Law, so phosphorus content can be suppressed. There is a demand for metal surface treatment agents.

Further, the metal surface treatment agents disclosed in Patent Documents 3 and 4 have a problem that the corrosion resistance of the surface of the metal material is lowered when the metal surface treatment agent is washed with water after the chemical conversion treatment.

Under such circumstances, the present invention can form a uniform coating film on the surface of a metal material with uniform thickness while suppressing the blending of environmentally regulated components, and can be used as a metal material having an excellent appearance. The main purpose is to provide a novel chrome-free metal surface treatment agent that can impart excellent corrosion resistance and paint adhesion to the material surface and effectively suppress the deterioration of corrosion resistance and paint adhesion due to water washing treatment. To do.

The present inventor has made diligent studies to solve the above problems. As a result, by using the aqueous silane compound as the metal surface treatment agent, a uniform coating film is formed on the surface of the metal material without adding chromium, while suppressing the addition of environmentally regulated components, resulting in an appearance. A chrome-free metal surface that can be used as an excellent metal material, can impart excellent corrosion resistance and paint adhesion to the surface of the metal material, and can effectively suppress deterioration of corrosion resistance and paint adhesion due to water washing treatment. It has been found that a treatment agent can be obtained.
The present invention is an invention completed by further studying based on these findings.

That is, the present invention provides the inventions of the following aspects.
Item 1. A chromium-free metal surface treatment agent containing the aqueous silane compound (A).
Item 2. Item 1. The aqueous silane compound (A) is at least one selected from the group consisting of an aqueous silane oligomer having a reactive functional group and an aqueous sol-gel silane polymer having a reactive functional group. The chrome-free metal surface treatment agent described.
Item 3. Item 2. The chromium-free metal surface treatment agent according to Item 2, wherein the reactive functional group is at least one selected from the group consisting of an amino group, an alkyl group, an epoxy group, and a diamino group.
Item 4. Item 2. The chromium-free metal surface treatment agent according to any one of Items 1 to 3, wherein the concentration of the aqueous silane compound (A) is 10 to 90% by mass.
Item 5. Item 2. The chromium-free metal surface treatment agent according to any one of Items 1 to 3, wherein the concentration of the aqueous silane compound (A) is 100 to 500,000 ppm.
Item 6. Further comprising at least one selected from the group consisting of an amine compound (B), a silicon compound (C), a phosphonic acid compound (D), an organic acid compound (E), and a chelating agent (F). Item 4. The chrome-free metal surface treatment agent according to any one of Items 1 to 4.
Item 7. The amine compound (B) is aqueous ammonia, ammonium chloride, ammonium fluoride, ammonium silicate, tetra-n-butylammonium fluoride, tetra-n-butylammonium hydroxide, tetra-n-butylammonium chloride, tetra. Methylammonium fluoride, tetramethylammonium hydroxide, tetramethylammonium chloride, ammonium nitrate, ammonium sulfate, hydroxylammonium phosphate, hydroxylammonium sulfate, hydroxylammonium chloride, ammonium dihydrogen citrate, monoammonium phosphate, diammonium phosphate, acetate Ammonium, ammonium dihydrogen citrate, methylamine, dimethylamine, trimethylamine, N-methyldiethanolamine, ethylamine, ethylenediamine, diethylamine, triethylamine, tetramethylethylenediamine, monoethanolamine, diethanolamine, triethanolamine, hexamethylenediamine, subermidin, subermin , 4-Aminoantipyrine, N, N-dimethyl-4-aminopyridine, naphthylamine, N-ethylformamide, ammonium amidosulfate, urea, thiourea, pyrazole, imidazole, and at least one selected from the group consisting of amino acids. , Item 6. The chrome-free metal surface treatment agent according to Item 6.
Item 8. The silicon compound (C) is sodium metasilicate, sodium orthosilicate, potassium silicate, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3 Item 6. The chromium-free metal surface treatment agent according to Item 6, which is at least one selected from the group consisting of −aminopropyltriethoxysilane and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane.
Item 9. The phosphonic acid compound (D) is derived from 1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, nitrilotris (methylenephosphonic acid), and ethylenediaminetetramethylenephosphonic acid. Item 6. The chromium-free metal surface treatment agent according to Item 6, which is at least one selected from the above group.
Item 10. At least one of the organic acid-based compound (E) selected from the group consisting of oxalic acid, acetic acid, citric acid, lactic acid, malic acid, gluconic acid, tartaric acid, formic acid, glutaric acid, adipic acid, sebacic acid, and ascorbic acid. Item 6. The chrome-free metal surface treatment agent according to Item 6, which is a seed.
Item 11. The chelating agent (F) is ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid disodium, ethylenediaminetetraacetic acid trisodium, ethylenediaminetetraacetic acid tetrasodium, ethylenediamine-N, N, N', N'-tetraacetic acid disammonium salt, ethylenediaminetetraacetic acid. Item 6. The chromium-free metal surface treatment agent according to Item 6, which is at least one selected from the group consisting of a chelating agent that forms a trisodium acetate salt, a fatty acid amine salt, and a chelating agent that forms an aromatic nitrogen compound.
Item 12. Item 6. The chromium-free metal surface treatment agent according to Item 6, wherein the mass ratio of the aqueous silane compound (A) to the amine compound (B) is 1: 10 to 1,000: 1.
Item 13. Item 6. The chromium-free metal surface treatment agent according to Item 6, wherein the mass ratio of the aqueous silane compound (A) to the silicon-based compound (C) is 1: 10 to 1,000: 1.
Item 14. Item 6. The chromium-free metal surface treatment agent according to Item 6, wherein the mass ratio of the aqueous silane compound (A) to the phosphonic acid compound (D) is 1: 10 to 1,000: 1.
Item 15. Item 6. The chromium-free metal surface treatment agent according to Item 6, wherein the mass ratio of the aqueous silane compound (A) to the organic acid-based compound (E) is 1: 10 to 1,000: 1.
Item 16. Item 6. The chromium-free metal surface treatment agent according to Item 6, wherein the mass ratio of the aqueous silane compound (A) to the chelating agent (F) is 1: 10 to 1,000: 1.
Item 17. Item 2. The chromium-free metal surface treatment agent according to any one of Items 1 to 16, wherein the pH is in the range of 1 to 9.
Item 18. Item 6. The chromium-free metal surface treatment agent according to Item 17, further comprising a pH adjuster.
Item 19. Item 2. The chromium-free metal surface treatment agent according to Item 18, wherein the pH adjuster is an inorganic compound.
Item 20. Item 19. The chromium-free metal surface treatment agent according to Item 19, wherein the inorganic compound is at least one selected from the group consisting of phosphoric acid, sulfuric acid, nitric acid, acetic acid, and caustic soda.
Item 21. Item 2. The chromium-free metal surface treatment agent according to any one of Items 1 to 20, which is used for surface treatment of aluminum, zinc, magnesium, iron, copper, or an alloy containing at least one of these metals.
Item 22. A contact step of bringing the chromium-free metal surface treatment agent according to any one of Items 1 to 21 into contact with the surface of a metal material, and
A treatment step in which the metal material having the chromium-free metal surface treatment agent adhered to the surface is placed in an environment of 15 to 80 ° C.
A metal surface treatment method.
Item 23. Item 22. The metal surface treatment method according to Item 22, further comprising a water washing step of washing the surface of the metal material with rinsing water after the treatment step.
Item 24. Item 23. The metal surface treatment method according to Item 23, further comprising a dilution step of diluting the chromium-free metal surface treatment agent with diluting water before the contact step.
Item 25. Item 2. The metal surface treatment method according to any one of Items 22 to 24, wherein the treatment time of the treatment step is 10 to 300 seconds.

According to the present invention, a uniform coating film is formed on the surface of a metal material without uneven thickness while suppressing the blending of environmentally regulated components, so that the metal material has an excellent appearance, and the surface of the metal material is excellent. It is possible to provide a novel chrome-free metal surface treatment agent which can impart corrosion resistance and paint adhesion and effectively suppress deterioration of corrosion resistance and paint adhesion due to water washing treatment. Further, according to the present invention, it is also possible to provide a metal surface treatment method using the chromium-free metal surface treatment agent.

1. 1. Chromium-free metal surface treatment agent The chromium-free metal surface treatment agent of the present invention is characterized by containing an aqueous silane compound (A). More specifically, the chromium-free metal surface treatment agent of the present invention is an aqueous chromium-free metal surface treatment agent containing the aqueous silane compound (A) and water.

In the present invention, chromium-free means that chromium is substantially not contained, for example, it means that the content of chromium in the chromium-free metal surface treatment agent is 0.4 ppm or less, preferably 0 ppm. Is.

In the chromium-free metal surface treatment agent of the present invention, the concentration of the aqueous silane compound (A) is not particularly limited. For example, the chromium-free metal surface treatment agent of the present invention is used as a stock solution and mixed with diluted water at the time of use. When used, the concentration of the aqueous silane compound (A) is preferably about 10 to 90% by mass, more preferably about 20 to 80% by mass, still more preferably about 40 to 60% by mass. By mixing such a high-concentration chromium-free metal surface treatment agent (stock solution) with diluted water, a chromium-free metal surface treatment agent having a suitable concentration can be easily prepared.

Further, in the present invention, the concentration of the aqueous silane compound (A) in the chromium-free metal surface treatment agent when brought into contact with the metal surface is preferably about 100 to 500,000 ppm, more preferably 1,000 to 100. About 000 ppm, more preferably about 2,500 to 100,000 ppm can be mentioned. Since the aqueous silane compound (A) is contained in such a concentration, an appropriate amount of the aqueous silane compound (A) can be adhered to the surface of the metal material, and the surface of the metal material is uniformly coated with an even thickness. A film is formed to impart an excellent appearance to the surface of the metal material, to impart excellent corrosion resistance and paint adhesion to the surface of the metal material, and further, deterioration of corrosion resistance and paint adhesion due to water washing treatment is suitably suppressed.

While suppressing the blending of environmentally regulated components, a uniform coating film with uneven thickness is suitably formed on the surface of the metal material to give an excellent appearance to the surface of the metal material, and further, excellent corrosion resistance and adhesion to the paint on the surface of the metal material. The aqueous silane compound (A) is preferably an aqueous silane oligomer having a reactive functional group from the viewpoint of preferably imparting properties and more effectively suppressing deterioration of corrosion resistance and paint adhesion due to water washing treatment. , Aqueous sol-gel silane polymer having a reactive functional group. Only one type of the aqueous silane compound (A) may be used, or two or more types may be mixed and used.

The reactive functional groups in the aqueous silane oligomer having a reactive functional group and the aqueous sol-gel silane polymer having a reactive functional group include an amino group, an alkyl group, an epoxy group, a vinyl group and a diamino group, respectively. It is preferable that it is at least one selected from the group. These functional groups can enhance the adhesion of the chromium-free metal surface treatment agent of the present invention to the surface of the metal material.

Specific examples of the aqueous silane oligomer having a reactive functional group include amino-modified siloxane, amino-modified polysiloxane, and amino-modified alkylpolysiloxane.

Specific examples of the aqueous sol-gel silane polymer having a reactive functional group include amino-modified silicone formate, amino-modified silicone formate, and amino-modified colloidal silicic acid.

While suppressing the blending of environmentally regulated components, a uniform coating film with uneven thickness is suitably formed on the surface of the metal material to give an excellent appearance to the surface of the metal material, and further, excellent corrosion resistance and adhesion to the paint on the surface of the metal material. From the viewpoint of preferably imparting properties and more effectively suppressing deterioration of corrosion resistance and paint adhesion due to water washing treatment, the chromium-free metal surface treatment agent of the present invention is an amine compound (B), if necessary. ), Silicon-based compound (C), phosphonic acid-based compound (D), organic acid-based compound (E) such as carboxylic acid-based compound, chelating agent (F), and additives such as pH adjuster. Good. Only one type of additive may be used, or two or more types may be mixed and used.

Preferred specific examples of the amine compound (B) are aqueous ammonia (ammonia), ammonium chloride, ammonium fluoride, ammonium silicate, tetra-n-butylammonium fluoride, tetra-n-butylammonium hydroxide, tetrachloride. -N-butylammonium, tetramethylammonium fluoride, tetramethylammonium hydroxide, tetramethylammonium chloride, ammonium nitrate, ammonium sulfate, hydroxylammonium phosphate, hydroxylammonium sulfate, hydroxylammonium chloride, ammonium dihydrogen citrate, monoammonium phosphate , Diammonium phosphate, ammonium acetate, ammonium dihydrogen citrate, methylamine, dimethylamine, trimethylamine, N-methyldiethanolamine, ethylamine, ethylenediamine, diethylamine, triethylamine, tetramethylethylenediamine, monoethanolamine, diethanolamine, triethanolamine, Hexamethylenediamine, subermidin, subermin, 4-aminoantipyrine, N, N-dimethyl-4-aminopyridine, naphthylamine, N-ethylformamide, ammonium amidosulfate, urea, thiourea, pyrazole, imidazole, amino acids and the like can be mentioned. As the amine compound (B), only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the mass ratio of the aqueous silane compound (A) to the amine compound (B) is such that the surface of the metal material is uniformly coated while suppressing the blending of environmentally regulated components. The film is suitably formed to give an excellent appearance to the surface of the metal material, and further, excellent corrosion resistance and paint adhesion are preferably given to the surface of the metal material, and the deterioration of the corrosion resistance and the paint adhesion due to the washing treatment is further improved. From the viewpoint of more effective suppression, a ratio of 1: 10 to 1,000: 1, more preferably 1: 1 to 200: 1, and even more preferably 1: 1 to 100: 1 can be mentioned.

Preferred specific examples of the silicon-based compound (C) include sodium metasilicate, sodium orthosilicate, potassium silicate, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and so on, from the same viewpoint. Examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane. As the silicon-based compound (C), only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the mass ratio of the aqueous silane compound (A) to the silicon-based compound (C) is preferably 1: 10 to 1,000: 1, more preferably 1: 10 to 1,000: 1 from the same viewpoint. A ratio of 1: 1 to 200: 1, more preferably 1: 1 to 100: 1 can be mentioned.

Preferred specific examples of the phosphonic acid-based compound (D) include 1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and nitrilotris (methylenephosphonic acid) from the same viewpoint. ), Ethylenediaminetetramethylenephosphonic acid and the like. As the phosphonic acid compound (D), only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the mass ratio of the aqueous silane compound (A) to the phosphonic acid compound (D) is preferably 1: 10 to 1,000: 1, more preferably from the same viewpoint. Is a ratio of 1: 1 to 200: 1, more preferably 1: 1 to 100: 1.

Preferred specific examples of the organic acid-based compound (E) include oxalic acid, acetic acid, citric acid, lactic acid, malic acid, gluconic acid, tartaric acid, formic acid, glutaric acid, adipic acid, sebacic acid, ascorbic acid and the like from the same viewpoint. Carboxylic acid-based compounds can be mentioned. As the organic acid-based compound (E), only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the mass ratio of the aqueous silane compound (A) to the organic acid-based compound (E) is preferably 1: 10 to 1,000: 1, more preferably from the same viewpoint. Is a ratio of 1: 1 to 200: 1, more preferably 1: 1 to 100: 1.

As a preferable specific example of the chelating agent (F), from the same viewpoint, ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid disodium, ethylenediaminetetraacetic acid trisodium, ethylenediaminetetraacetic acid tetrasodium, ethylenediamine-N, N, N', N' Examples thereof include diammonium tetraacetic acid salt, trisodium ethylenediaminetetraacetic acid salt, chelating agent forming fatty acid amine salts, and chelating agent forming aromatic nitrogen compound. As the chelating agent (F), only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the mass ratio of the aqueous silane compound (A) to the chelating agent (F) is preferably 1: 10 to 1,000: 1, more preferably 1 from the same viewpoint. : 1 to 200: 1, more preferably a ratio of 1: 1 to 100: 1.

The pH adjuster is not particularly limited, but an inorganic compound such as phosphoric acid, sulfuric acid, nitric acid, acetic acid, and caustic soda is preferable. As the pH adjuster, only one type may be used, or two or more types may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the content of the pH adjuster is not particularly limited, and is, for example, an amount required for the pH of the chromium-free metal surface treatment agent of the present invention to be the pH described later. can do.

In the chromium-free metal surface treatment agent of the present invention, the total mass ratio of the aqueous silane compound (A) and these additives is preferably 1: 10 to 1,000: 1, more preferably 1: 10 to 1,000: 1 from the same viewpoint. A ratio of 1: 1 to 200: 1, more preferably 1: 1 to 100: 1 can be mentioned.

In the chrome-free metal surface treatment agent of the present invention, a uniform coating film having no uneven thickness is suitably formed on the surface of the metal material while suppressing the blending of environmentally regulated components to give an excellent appearance to the surface of the metal material. Aqueous silane compound (A) (aqueous sol-) from the viewpoint of suitably imparting excellent corrosion resistance and paint adhesion to the surface of a metal material and more effectively suppressing deterioration of corrosion resistance and paint adhesion due to water washing treatment. A gel-based silane polymer is preferable), and at least one of an amine-based compound (B), a silicon-based compound (C), and a phosphonic acid-based compound (D) is preferably contained. In this treatment agent, the content of the aqueous silane compound (A) is in the range of 3000 to 10000 ppm, and the content when the amine compound (B) is contained is in the range of 100 to 5000 ppm, and the silicon compound. The content when (C) is contained is preferably in the range of 1000 to 2000 ppm, and the content when the phosphonic acid compound (D) is contained is preferably in the range of 2000 to 3000 ppm.

In the chromium-free metal surface treatment agent of the present invention, for example, the following composition is mentioned as a particularly preferable composition.
Composition 1: The aqueous silane compound (A) (preferably an aqueous sol-gel silane polymer) is in the range of 4000 to 6000 ppm, the phosphonic acid compound (D) is in the range of 2000 to 3000 ppm, and the pH is 2. It is 0 to 4.0.
Composition 2: The aqueous silane compound (A) (preferably an aqueous sol-gel silane polymer) is in the range of 5000 to 15000 ppm, the amine compound (B) is in the range of 100 to 7000 ppm, and the pH is 4.0. ~ 8.0.
Composition 3: The aqueous silane compound (A) (preferably an aqueous sol-gel silane polymer) is in the range of 1000 to 5000 ppm, the amine compound (B) is in the range of 100 to 5000 ppm, and the silicon compound (C). ) Is in the range of 1000 to 2000 ppm, and the pH is 2.0 to 6.0.

The water contained in the chromium-free metal surface treatment agent of the present invention is not particularly limited, and examples thereof include ion-exchanged water, tap water, distilled water, and pure water. Only one kind of water may be used, or two or more kinds of water may be mixed and used.

In the chromium-free metal surface treatment agent of the present invention, the water content is the above-mentioned aqueous silane compound (A), the above-mentioned amine compound (B), silicon-based compound (C), and phosphone, which are blended as needed. It is the balance after removing additives such as an acid compound (D), an organic acid compound (E), a chelating agent (F), and a pH adjuster.

When the chromium-free metal surface treatment agent of the present invention is used as a stock solution and mixed with diluted water at the time of use, the content of water in the chromium-free metal surface treatment agent is, for example, about 10 to 90% by mass. is there. Further, the water content when the chromium-free metal surface treatment agent of the present invention is brought into contact with the metal surface is, for example, about 80 to 99% by mass.

The pH of the chromium-free metal surface treatment agent of the present invention is not particularly limited, but it is excellent on the surface of the metal material by forming a uniform coating film on the surface of the metal material without uneven thickness while suppressing the blending of environmentally regulated components. From the viewpoint of imparting an appearance, further imparting excellent corrosion resistance and paint adhesion to the surface of the metal material, and effectively suppressing deterioration of corrosion resistance and paint adhesion due to water washing treatment, it is preferably about 1 to 9. It is preferably about 2 to 8, and more preferably about 2.5 to 7.

The treatment target of the chromium-free metal surface treatment agent of the present invention is not particularly limited as long as it is a metal surface, but in particular, the surface of aluminum, zinc, magnesium, iron, copper, or an alloy containing at least one of these metals. It is preferably used for treatment. By using the chrome-free metal surface treatment agent of the present invention for the surface treatment of these metals, a uniform coating film having no uneven thickness is suitably formed on the surface of the metal material while suppressing the blending of environmentally restrictive components, resulting in an appearance. It is possible to obtain an excellent metal material, further, it is possible to suitably impart excellent corrosion resistance and paint adhesion to the surface of the metal material, and it is possible to more effectively suppress deterioration of corrosion resistance and paint adhesion due to water washing treatment. it can.

2. Metal Surface Treatment Method The metal surface treatment method of the present invention comprises a contact step of bringing the chrome-free metal surface treatment agent of the present invention into contact with the surface of the metal material, and a metal material having the chrome-free metal surface treatment agent adhered to the surface. It is characterized by including a treatment step of placing it in an environment of about 80 ° C.

In the metal surface treatment method of the present invention, since the chrome-free metal surface treatment agent of the present invention is used, a uniform coating film is formed on the surface of the metal material without uneven thickness while suppressing the blending of environmentally regulated components. It is possible to impart an excellent appearance to the surface, further impart excellent corrosion resistance and paint adhesion to the surface of the metal material, and effectively suppress deterioration of corrosion resistance and paint adhesion due to water washing treatment.

Details of the chromium-free metal surface treatment agent of the present invention are as described above. When the chromium-free metal surface treatment agent of the present invention is applied to a metal surface treatment method, the present invention is required so that the amount of the aqueous silane compound (A) adhering to the surface of the metal material is appropriate. Diluting water may be added to the chromium-free metal surface treatment agent of.

In the metal surface treatment method of the present invention, the amount of the coating film formed on the surface of the metal material is not particularly limited, but the amount of the aqueous silane compound (A) present on the surface of the metal material after drying is, for example, 100. An amount of about 200 mg / m ² can be mentioned.

In the contact step of bringing the chromium-free metal surface treatment agent of the present invention into contact with the surface of the metal material, as a method of contacting the chromium-free metal surface treatment agent, the chromium-free metal surface treatment agent contacts and adheres to the surface of the metal material. Then, without particular limitation, it can be carried out by a known method such as a roll coating method, a spin coating method, a spray method, and a dipping method.

Next, a treatment step is performed in which the metal material on which the chromium-free metal surface treatment agent is attached is placed in an environment of 10 to 80 ° C. In the treatment step, it is sufficient that the chromium-free metal surface treatment agent can be in contact with the surface of the metal material for a sufficient time, and it is preferably about 10 to 300 seconds in an environment of 10 to 80 ° C.

The metal surface treatment method of the present invention may further include a dilution step of diluting the chromium-free metal surface treatment agent with diluting water before the contact step. By the dilution step, the amount of the aqueous silane compound (A) adhering to the surface of the metal material can be adjusted to be appropriate. When the chromium-free metal surface treatment agent of the present invention is used in advance so that the amount of the aqueous silane compound (A) adhering to the surface of the metal material is appropriate, the dilution step is not required. is there.

In the metal surface treatment method of the present invention, it is preferable to carry out a contact step on the surface of the metal material whose surface has been washed. The main purpose of cleaning the surface of a metal material is to remove various stains (oil, etc.) adhering to the surface of the metal material. The method for cleaning the surface of the metal material is not particularly limited, and for example, a method using a known cleaning agent such as an alkaline degreasing agent or an acidic degreasing agent can be adopted. Further, it is preferable to wash the cleaning agent adhering to the surface of the metal material with water before using the metal surface treatment method of the present invention.

Further, the metal surface treatment method of the present invention further includes a water washing step of washing the surface of the coating film formed on the surface of the metal material with rinsing water after the step of treating the surface of the metal material with a chromium-free metal surface treatment agent. You may be. As described above, for example, the metal surface treatment agents disclosed in Patent Documents 3 and 4 have a problem that the corrosion resistance and the paint adhesion on the surface of the metal material are lowered when the metal surface treatment is performed after the chemical conversion treatment. In the metal surface treatment method using the chrome-free metal surface treatment agent of the present invention, deterioration of corrosion resistance and paint adhesion on the surface of the metal material is effectively suppressed even when water washing treatment is performed after the treatment step.

Further, in the metal surface treatment method of the present invention, an anhydrous washing treatment may be performed after the step of treating the surface of the metal material with a chromium-free metal surface treatment agent. Examples of the method of the anhydrous washing treatment include air blow.

In the metal surface treatment method of the present invention, it is preferable to perform a drying treatment after the step of treating the surface of the metal material with a chromium-free metal surface treatment agent. By the drying treatment, the moisture contained in the chromium-free metal surface treatment agent can be suitably dried, and a strong dry coating film of the chromium-free metal surface treatment agent can be formed.

The drying step may be carried out by natural drying, or may be carried out at a temperature of about 30 to 200 ° C. under drying conditions of about 5 to 30 minutes.

In the metal surface treatment method of the present invention, the metal material to be treated is not particularly limited, but is particularly aluminum, zinc, magnesium, iron, copper, or an alloy containing at least one of these metals. Is preferable. By applying the metal surface treatment method of the present invention to the surface treatment of these metal materials, a uniform coating film having no uneven thickness is suitably formed on the surface of the metal material while suppressing the blending of environmentally restrictive components, resulting in an appearance. It is possible to obtain an excellent metal material, further, it is possible to suitably impart excellent corrosion resistance and paint adhesion to the surface of the metal material, and it is possible to more effectively suppress deterioration of corrosion resistance and paint adhesion due to water washing treatment. it can.

3. 3. Surface-treated metal material The surface-treated metal material of the present invention is a metal material whose surface is surface-treated with the chromium-free metal surface-treating agent of the present invention. That is, among the components contained in the chromium-free metal surface treatment agent of the present invention, components other than volatile components (water, etc.) are attached to the surface of the surface-treated metal material of the present invention.

Since the surface-treated metal material of the present invention is surface-treated with the chrome-free metal surface treatment agent of the present invention, adhesion of environmentally restrictive components is suppressed, and a uniform coating film is formed on the surface of the metal material with no uneven thickness. It has excellent appearance, corrosion resistance, and paint adhesion without impairing the metallic glossy color of the metallic material, and further, deterioration of corrosion resistance and paint adhesion due to water washing treatment is effectively suppressed.

The metal material constituting the surface-treated metal material of the present invention is not particularly limited, but may be aluminum, zinc, magnesium, iron, copper, or an alloy containing at least one of these metals. preferable.

The surface of the surface-treated metal material of the present invention may be further painted with a paint or the like. When the surface of the surface-treated metal material of the present invention is painted, the chromium-free metal surface-treating agent of the present invention serves as a base for the paint.

The paint is not particularly limited, and known paints including, for example, acrylic resin-based, fluororesin-based, urethane resin-based, silicon resin-based, epoxy resin-based, melamine resin-based, polyester resin-based, and the like can be used. ..

In the surface-treated metal material of the present invention, since the metal material is surface-treated by the above-mentioned metal treatment agent of the present invention, the surface of the metal material is coated with these paints to treat the surface with the metal treatment agent. It is possible to improve the hardness, corrosion resistance, and paint adhesion of the surface of the painted metal material while exhibiting high adhesion to the paint later. Further, by using a transparent paint, it is possible to impart an excellent appearance to the surface-treated metal material of the present invention by making the best use of the gloss of the metal material.

When painting with paint, it is preferable to perform baking. The baking conditions are not particularly limited and may be appropriately set according to the type of paint and the like, and examples thereof include baking at 100 to 250 ° C. for 5 to 90 minutes.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

1. 1. Preparation of Chromium-Free Metal Surface Treatment Agent <Examples 1-39>
Each component was mixed so as to have the compounding ratio shown in Table 1 (the balance is ion-exchanged water) to obtain a chromium-free metal surface treatment agent. The details of each component are as follows. The pH of the chromium-free metal surface treatment agent is shown in Table 1.

-Aqueous silane compound (A)
A1: Dynasylan (registered trademark) SIVO110 (manufactured by Evonik Industries))
A2: Dynasylan (registered trademark) SIVO160 (manufactured by Evonik Industries))
A3: Dynasylan (registered trademark) HYDROSIL2909 (manufactured by Evonik Industries))

-Amine compound (B)
B1: Ammonia water B2: Hydroxammonium phosphate B3: Ammonium silice B4: Tetra-n-butylammonium fluoride B5: Ammonium fluoride B6: Ammonium amidosulfate B7: Tetra-n-butylammonium chloride

-Silicon compound (C)
C1: Soda metasilicate C2: 3-glycidoxypropyltriethoxysilane

-Phosphonate compound (D)
D1: 2-phosphonobutane-1,2,4-tricarboxylic acid

-Organic acid compounds (carboxylic acid compounds) (E)
E1: Oxalic acid E2: Ascorbic acid

・ Chelating agent (F)
F1: Kirest 2N40 (manufactured by Kirest Co., Ltd.)
F2: Killes Light WZ-7 (manufactured by Killest Co., Ltd.)

2. Manufacture of surface-treated metal material Aluminum material (A5052 material) is a 5% aqueous solution of each degreasing agent shown in Table 2 (acidity is "Alclean EP01" manufactured by Kiwa Chemicals, alkaline is "alkylene F700K" manufactured by Kiwa Chemicals. Was washed with (3% aqueous solution of) and washed with water. Next, the aluminum material is dipped in each metal surface treatment agent and treated under the treatment process conditions (treatment temperature and treatment time) shown in Table 2 to form a coating film of each metal surface treatment agent on the surface of the aluminum material. did. Next, the coating film was dried under the drying conditions of 150 ° C. for 10 minutes to obtain each surface-treated metal material.

In Comparative Examples 1 and 2, a coating film of the metal surface treatment agent was not formed on the surface of the aluminum material. Further, in Comparative Examples 3 to 6, the organic phosphonic acid polymer (copolymer of vinylphosphonic acid and acrylic acid, weight average molecular weight of 40,000, molar ratio of vinylphosphonic acid and acrylic acid is 1: 3, 2400 ppm). Each surface-treated metal material was obtained using a metal surface-treating agent containing an alkylphosphonic acid (octylphosphonic acid, 1200 ppm).

3. 3. Evaluation of corrosion resistance of surface-treated metal material In order to evaluate the corrosion resistance of the surface-treated metal material obtained above, the area where white rust occurs after spraying salt water (concentration 5%) on the surface and leaving it at room temperature for 48 hours. Was visually observed and evaluated according to the following criteria. The results are shown in Table 3.
◯: White rust area is 10% or less Δ: White rust area is more than 10%, 20% or less ×: White rust area is more than 20%

In addition, each surface-treated metal material using ADC12 material, ADC10 material, or A6063 material as an aluminum material is also manufactured, and the following "4. Painting of surface-treated metal material" and "5. Paint adhesion evaluation" are performed. It was. However, in Table 3, "-" indicates that no evaluation has been performed.

4. Painting of surface-treated metal materials For each of the surface-treated metal materials obtained above, melamine alkyd resin-based paint (Deliyun # 300, 5-minute gloss 5Y9 / 0.5) manufactured by Dainippon Paint Co., Ltd. and Kansai Paint Co., Ltd. Amino acrylic resin-based paint (Magicron 1000) or urethane resin-based paint, respectively, was applied and baked at 140 ° C. for 20 minutes to coat with a coating thickness of 20 to 30 μm.

5. Evaluation of paint adhesion The following adhesion evaluation and cas test were performed on each surface-treated metal material coated above to evaluate the paint adhesion . The results are shown in Table 3.

[Adhesion (primary adhesion)]
The surface of each surface-treated metal material coated above was cross-cut with 100 squares at 1 mm intervals. An adhesive tape (cellophane adhesive tape manufactured by Nichiban Co., Ltd., CT405AP-24) was attached from above, and then peeled off, and the number of peeled cells out of 100 squares was measured and evaluated according to the following criteria.
◯: No peeling of coating film (paint) Δ: Peeling of coating film (paint) is 20% or less ×: Peeling of coating film (paint) exceeds 20%

[Cass test]
A cross cut is made near the center of each surface-treated metal material coated above with a cutter, the Cass test described in JIS-Z-2371 is performed for 144 hours, and the swelling width of the coating film at the cross cut portion is measured and described below. Evaluated by criteria.
⊚: No swelling ○: Swelling width is 1.0 mm or less Δ: Swelling width exceeds 1.0 mm, 3.0 mm or less ×: Swelling width exceeds 3.0 mm

Claims (25)

A chromium-free metal surface treatment agent containing the aqueous silane compound (A). Claim 1 that the aqueous silane compound (A) is at least one selected from the group consisting of an aqueous silane oligomer having a reactive functional group and an aqueous sol-gel silane polymer having a reactive functional group. The chrome-free metal surface treatment agent described in. The chromium-free metal surface treatment agent according to claim 2, wherein the reactive functional group is at least one selected from the group consisting of an amino group, an alkyl group, an epoxy group, and a diamino group. The chromium-free metal surface treatment agent according to any one of claims 1 to 3, wherein the concentration of the aqueous silane compound (A) is 10 to 90% by mass. The chromium-free metal surface treatment agent according to any one of claims 1 to 3, wherein the concentration of the aqueous silane compound (A) is 100 to 500,000 ppm. Further comprising at least one selected from the group consisting of an amine compound (B), a silicon compound (C), a phosphonic acid compound (D), an organic acid compound (E), and a chelating agent (F). The chrome-free metal surface treatment agent according to any one of claims 1 to 4. The amine compound (B) is aqueous ammonia, ammonium chloride, ammonium fluoride, ammonium silicate, tetra-n-butylammonium fluoride, tetra-n-butylammonium hydroxide, tetra-n-butylammonium chloride, tetra. Methylammonium fluoride, tetramethylammonium hydroxide, tetramethylammonium chloride, ammonium nitrate, ammonium sulfate, hydroxylammonium phosphate, hydroxylammonium sulfate, hydroxylammonium chloride, ammonium dihydrogen citrate, monoammonium phosphate, diammonium phosphate, acetate Ammonium, ammonium dihydrogen citrate, methylamine, dimethylamine, trimethylamine, N-methyldiethanolamine, ethylamine, ethylenediamine, diethylamine, triethylamine, tetramethylethylenediamine, monoethanolamine, diethanolamine, triethanolamine, hexamethylenediamine, subermidin, subermin , 4-Aminoantipyrine, N, N-dimethyl-4-aminopyridine, naphthylamine, N-ethylformamide, ammonium amidosulfate, urea, thiourea, pyrazole, imidazole, and at least one selected from the group consisting of amino acids. , The chrome-free metal surface treatment agent according to claim 6. The silicon compound (C) is sodium metasilicate, sodium orthosilicate, potassium silicate, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3 The chromium-free metal surface treatment agent according to claim 6, which is at least one selected from the group consisting of −aminopropyltriethoxysilane and N-2- (aminoethyl) -3-aminopropyltrimethoxysilane. The phosphonic acid compound (D) is derived from 1-hydroxyethane-1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, nitrilotris (methylenephosphonic acid), and ethylenediaminetetramethylenephosphonic acid. The chromium-free metal surface treatment agent according to claim 6, which is at least one selected from the group. At least one of the organic acid-based compound (E) selected from the group consisting of oxalic acid, acetic acid, citric acid, lactic acid, malic acid, gluconic acid, tartaric acid, formic acid, glutaric acid, adipic acid, sebacic acid, and ascorbic acid. The chrome-free metal surface treatment agent according to claim 6, which is a seed. The chelating agent (F) is ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid disodium, ethylenediaminetetraacetic acid trisodium, ethylenediaminetetraacetic acid tetrasodium, ethylenediamine-N, N, N', N'-tetraacetic acid disammonium salt, ethylenediaminetetraacetic acid. The chromium-free metal surface treatment agent according to claim 6, which is at least one selected from the group consisting of a chelating agent that forms a trisodium acetate salt, a fatty acid amine salt, and a chelating agent that forms an aromatic nitrogen compound. The chromium-free metal surface treatment agent according to claim 6, wherein the mass ratio of the aqueous silane compound (A) to the amine compound (B) is 1: 10 to 1,000: 1. The chromium-free metal surface treatment agent according to claim 6, wherein the mass ratio of the aqueous silane compound (A) to the silicon-based compound (C) is 1: 10 to 1,000: 1. The chromium-free metal surface treatment agent according to claim 6, wherein the mass ratio of the aqueous silane compound (A) to the phosphonic acid-based compound (D) is 1: 10 to 1,000: 1. The chromium-free metal surface treatment agent according to claim 6, wherein the mass ratio of the aqueous silane compound (A) to the organic acid-based compound (E) is 1: 10 to 1,000: 1. The chromium-free metal surface treatment agent according to claim 6, wherein the mass ratio of the aqueous silane compound (A) to the chelating agent (F) is 1: 10 to 1,000: 1. The chromium-free metal surface treatment agent according to any one of claims 1 to 16, wherein the pH is in the range of 1 to 9. The chromium-free metal surface treatment agent according to claim 17, further comprising a pH adjuster. The chromium-free metal surface treatment agent according to claim 18, wherein the pH adjuster is an inorganic compound. The chromium-free metal surface treatment agent according to claim 19, wherein the inorganic compound is at least one selected from the group consisting of phosphoric acid, sulfuric acid, nitric acid, acetic acid, and caustic soda. The chromium-free metal surface treatment agent according to any one of claims 1 to 20, which is used for surface treatment of aluminum, zinc, magnesium, iron, copper, or an alloy containing at least one of these metals. A contact step of bringing the chromium-free metal surface treatment agent according to any one of claims 1 to 21 into contact with the surface of a metal material.
A treatment step in which the metal material having the chromium-free metal surface treatment agent adhered to the surface is placed in an environment of 15 to 80 ° C.
A metal surface treatment method. The metal surface treatment method according to claim 22, further comprising a water washing step of washing the surface of the metal material with rinsing water after the treatment step. The metal surface treatment method according to claim 23, further comprising a dilution step of diluting the chromium-free metal surface treatment agent with diluting water before the contact step. The metal surface treatment method according to any one of claims 22 to 24, wherein the treatment time of the treatment step is 10 to 300 seconds.