KR102500400B1 - Surface treatment agent, aluminum or aluminum alloy material having surface treatment film, and manufacturing method thereof - Google Patents

Abstract

It is an object to provide a surface treatment agent for aluminum or aluminum alloy materials capable of forming a surface treatment film having excellent corrosion resistance on aluminum or aluminum alloy materials and having excellent corrosion resistance even when the film is exposed to high temperatures. An ion (A) containing trivalent chromium, at least one ion (B) selected from ions containing titanium and ions containing zirconium, an ion (C) containing zinc, and a free fluorine ion ( D) and a surface treatment agent that contains nitrate ions (E) and is used for surface treatment of aluminum or aluminum alloy materials.

Description

Surface treatment agent, aluminum or aluminum alloy material having surface treatment film, and manufacturing method thereof

The present invention relates to a surface treatment agent used for surface treatment of aluminum or aluminum alloy material, an aluminum or aluminum alloy material having a surface treatment film formed by the surface treatment agent, and a method for producing the same.

As a surface treatment agent for aluminum or aluminum alloy materials in a wide range of fields such as aircraft materials, building materials, and automobile parts, surface treatment agents for metal materials containing trivalent chromium have conventionally been developed.

For example, in Patent Document 1, a component (A) composed of a water-soluble trivalent chromium compound, a component (B) composed of at least one selected from a water-soluble titanium compound and a water-soluble zirconium compound, and a component composed of a water-soluble nitrate compound ( Disclosed is a chemical conversion treatment liquid for metal materials containing C), a component (D) composed of a water-soluble aluminum compound, and a component (E) composed of a fluorine compound, and having a pH controlled in the range of 2.3 to 5.0. there is.

Patent Literature 2 discloses a chemical conversion treatment liquid containing a specific trivalent chromium compound, a specific zirconium compound, and a specific dicarboxylic acid compound in predetermined amounts.

Japanese Unexamined Patent Publication No. 2006-328501 Japanese Unexamined Patent Publication No. 2006-316334

However, the corrosion resistance of the film formed on aluminum or aluminum alloy material using the surface treatment agent according to Patent Literatures 1 and 2 may deteriorate due to exposure to a high-temperature environment depending on the use of the aluminum or aluminum alloy material.

The present invention provides a surface treatment agent capable of forming a surface treatment film having excellent corrosion resistance on aluminum or an aluminum alloy material and having excellent corrosion resistance even when the film is exposed to high temperatures, and a surface treatment film formed by the surface treatment agent. It is an object to provide an aluminum or aluminum alloy material having and a method for producing the same.

As a result of intensive studies to solve the above problems, the present inventors have found that at least one ion (B) selected from an ion (A) containing trivalent chromium, an ion containing titanium and an ion containing zirconium, and , the surface treatment agent containing zinc-containing ions (C), free fluorine ions (D), and nitrate ions (E) has excellent corrosion resistance to aluminum or aluminum alloy materials, and the coating is exposed to high temperatures. It was found that a surface-treated film having excellent corrosion resistance can be formed even when the present invention is damaged, and the present invention has been completed.

The present invention for solving the above problems,

(1) an ion containing trivalent chromium (A), at least one ion selected from ions containing titanium and ions containing zirconium (B), an ion containing zinc (C), and glass a surface treatment agent containing fluorine ions (D) and nitrate ions (E) and used for surface treatment of aluminum or aluminum alloy materials;

(2) A method for producing an aluminum or aluminum alloy material having a surface-treated film, including a contact step of bringing the surface treatment agent according to (1) into contact with the surface or surface of the aluminum or aluminum alloy material;

(3) an aluminum or aluminum alloy material having a surface-treated film obtained by the production method described in the above (2);

etc.

According to the present invention, a surface treatment agent capable of forming a surface-treated film having excellent corrosion resistance on an aluminum or aluminum alloy material and having excellent corrosion resistance even when the film is exposed to high temperatures, and a surface treatment formed by the surface treatment agent It becomes possible to provide an aluminum or aluminum alloy material having a film and a manufacturing method thereof.

(1) Surface treatment agent

The surface treatment agent according to the present embodiment is a treatment agent for surface treatment of aluminum or aluminum alloy material. The said surface treatment agent can also be used as a chemical conversion treatment agent. The surface treatment agent comprises an ion (A) containing trivalent chromium, at least one ion (B) selected from ions containing titanium and ions containing zirconium, and an ion (C) containing zinc. , containing free fluorine ions (D) and nitrate ions (E). The surface treatment agent may be formulated with only these ion supply sources in an aqueous medium, or may be formulated with other components. Hereinafter, each component, composition (content), and liquid are described in detail. Moreover, as an ion containing the said metal, a metal ion, a metal oxide ion, a metal hydroxide ion, a metal complex ion, etc. are mentioned.

(Ion containing trivalent chromium)

The source of the trivalent chromium-containing ion (A) in the surface treatment agent is not particularly limited as long as it can provide the ion (A) by mixing it with an aqueous medium. For example, chromium fluoride, chromium nitrate, chromium sulfate, chromium phosphate, etc. are mentioned. Although these may use only 1 type, they may use 2 or more types. The content of the ion (A) in the surface treatment agent is not particularly limited, but is usually within the range of 5 to 1000 mg/L, preferably 20 to 700 mg/L in terms of chromium equivalent mass concentration. Also, in this embodiment, it is preferable not to contain hexavalent chromium ion. In addition, "it does not contain hexavalent chromium ion" does not mean that the content is zero, and unavoidable mixing is permitted. Specifically, it may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, or 0.1 mg/L or less.

(At least one ion selected from ions containing titanium and ions containing zirconium)

The supply source of at least one type of ion (B) selected from ions containing titanium and ions containing zirconium in the surface treatment agent is particularly limited as long as it can provide ions (B) by mixing with an aqueous medium. It is not. For example, titanium sulfate, titanium oxysulfate, ammonium titanate sulfate, titanium nitrate, titanium oxynitrate, ammonium titanium nitrate, hexafluorotitanic acid, hexafluorotitanium complex salt, zirconium sulfate, zirconium oxysulfate, ammonium zirconium sulfate, zirconium nitrate , zirconium oxynitrate, zirconium ammonium nitrate, hexafluorozirconic acid, hexafluorozirconium complex salt, titanium lactate, titanium acetylacetonate, titanium triethanolamine, titanium octyl glycolate, tetraisopropyl titanate, tetranormal butyl titanate nate, zirconyl acetate, zirconyl lactate, zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, tetranormal butoxyzirconium, tetranormal propoxyzirconium, and the like. Although these may use only 1 type, they may use 2 or more types. The content of the ion (B) in the surface treatment agent is not particularly limited, but is usually in the range of 5 to 1000 mg/L in terms of metal conversion mass concentration (total metal conversion mass concentration when two or more types of sources are mixed) within, preferably within the range of 20 to 700 mg/L.

(ion containing zinc)

The supply source of zinc-containing ions (C) in the surface treatment agent is not particularly limited as long as it can provide ions (C) by mixing with an aqueous medium. Examples thereof include metal zinc, zinc oxide, zinc carbonate, zinc nitrate, zinc chloride, zinc sulfate, zinc fluoride, zinc iodide, zinc dihydrogen phosphate, and zinc acetylacetonate. Although these may use only 1 type, they may use 2 or more types. The content of ions (C) in the surface treatment agent is not particularly limited, but is usually within the range of 20 to 10000 mg/L, may be within the range of 50 to 10000 mg/L in terms of mass concentration in terms of zinc, preferably It is within the range of 300 to 8000 mg/L, more preferably within the range of 700 to 5000 mg/L.

(free fluorine ion)

The supply source of free fluorine ions (D) in the surface treatment agent is not particularly limited as long as it can provide free fluorine ions (D) by mixing with an aqueous medium. For example, hydrofluoric acid, ammonium fluoride, chromium fluoride, hexafluorotitanic acid, hexafluorotitanium complex salt, hexafluorozirconic acid, hexafluorozirconium complex salt, magnesium fluoride, aluminum fluoride, hexafluorosilicic acid, sodium fluoride, Potassium fluoride, zinc fluoride, etc. are mentioned. Although these may use only 1 type, they may use 2 or more types. In addition, the free fluorine ion (D) may be provided by the same compound as the supply source of (A), (B) and/or (C) above, or may be provided by a different compound. The mass concentration of free fluorine ions (D) in the surface treatment agent in terms of fluorine is preferably from 3 to 100 mg/L, more preferably from 5 to 70 mg/L.

(Nitrate ion)

The supply source of nitrate ions (E) in the surface treatment agent is not particularly limited as long as nitrate ions (E) can be provided by mixing with an aqueous medium. Examples thereof include nitric acid, sodium nitrate, potassium nitrate, magnesium nitrate, ammonium nitrate, cerium nitrate, manganese nitrate, strontium nitrate, calcium nitrate, cobalt nitrate, aluminum nitrate, and zinc nitrate. Although these may use only 1 type, they may use 2 or more types. In addition, the nitrate ion (E) may be provided by the same compound as the supply source of (A), (B) and/or (C) above, or may be provided by a different compound. The content of nitrate ions (E) in the surface treatment agent is not particularly limited, but is usually within the range of 100 to 30000 mg/L in terms of mass concentration in terms of nitric acid.

(other ingredients)

Various metal components and additives may be added to the surface treatment agent of the present embodiment as long as they are within a range that does not impair the effect of the present invention. Examples of the metal component include vanadium, molybdenum, tungsten, manganese, cerium, magnesium, calcium, cobalt, nickel, strontium, lithium, niobium, yttrium, and bismuth. As the additive, a compound having a hydroxyl group, a compound having a formyl group, a compound having a benzoyl group, a compound having an amino group, a compound having an imino group, a compound having a cyano group, a compound having an azo group, a compound having a thiol group, a sulfo group A compound having a, a compound having a nitro group, a compound having a urethane bond, and the like are exemplified. Although only 1 type may be used for these metal components and additives, they may use 2 or more types. Since these additives are added within the range which does not impair the effect of this invention, their content is several mass % with respect to the total amount of surface treatment agents at most.

On the other hand, the surface treatment agent of the present embodiment preferably does not contain a compound having a carboxyl group, preferably does not contain a compound having an amidino group, preferably does not contain a compound having an aromatic ring, and preferably does not contain an organic substance. It is more preferable not to contain. By using a surface treatment agent that does not contain organic substances, a decrease in corrosion resistance of the film formed can be suppressed. In addition, "it does not contain organic matter" does not necessarily mean that the content is zero, and it is allowed to contain within the range which does not significantly impair the effect of this invention. Specifically, it may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, 0.1 mg/L or less, or zero. In addition, the organic substance refers to a compound containing carbon as a main component, and derivatives thereof may also be included in the organic substance.

(liquid)

The pH of the surface treatment agent according to the present embodiment is not particularly limited, but is preferably from 2.3 to 5.0, more preferably from 3.0 to 4.5. Here, pH in this specification means the value in the temperature at the time of making a surface treatment agent contact the surface or surface of an aluminum or aluminum alloy material. The pH can be measured, for example, by a portable electrical conductivity/pH meter [WM-32EP (manufactured by Toa DK Co., Ltd.)] or the like.

In the above, the composition of the surface treatment agent according to the present embodiment has been described, but another aspect of the present invention is to select from a source of trivalent chromium-containing ion (A), a titanium-containing ion, and a zirconium-containing ion. aluminum or aluminum obtained by blending at least one source of ions (B), a source of zinc-containing ions (C), a source of free fluoride ions (D), and a source of nitrate ions (E). It is a surface treatment agent used for surface treatment of alloy materials. In addition, the source of the free fluorine ion (D) may be the same compound as the source of (A), (B) and/or (C), or may be a different compound. In addition, the supply source of nitrate ion (E) may be the same compound as the supply source of (A), (B) and/or (C), or may be a different compound.

(2) Manufacturing method of surface treatment agent

The surface treatment agent according to the present embodiment is a source of the aforementioned trivalent chromium-containing ion (A), a source of at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, and , A source of zinc-containing ions (C), a source of free fluorine ions (D), and a source of nitrate ions (E) are blended in appropriate amounts in an aqueous medium and can be obtained by stirring. Further, during production, the solid supply source may be blended into an aqueous medium, or the solid supply source may be dissolved in an aqueous medium beforehand and then blended as an aqueous medium solution. In addition, the pH range of the surface treatment agent is as described above, and it is preferably adjusted using a pH adjuster such as nitric acid, hydrofluoric acid, ammonium bicarbonate, or aqueous ammonia, but is not limited to these components. Moreover, you may use 1 type(s) or 2 or more types of pH adjusters.

As the aqueous medium, water is typically used. A water-miscible organic solvent may be contained within a range not impairing the effect of the present invention, but it is preferably water. When containing a water-miscible organic solvent, it may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, or 0.1 mg/L or less.

(3) Method for producing an aluminum or aluminum alloy material having a surface-treated film

The method for producing an aluminum or aluminum alloy material having a film formed by the surface treatment agent according to the present embodiment includes a contact step of contacting the surface treatment agent according to the present embodiment to the surface or the surface of the aluminum or aluminum alloy material. . As a result, a surface treatment film is formed on the surface or surface of the aluminum or aluminum alloy material. You may perform a pretreatment process, such as a degreasing process and an acid pickling process, before a contact process. Moreover, a water washing process may be performed after each process, and a drying process may be performed after the water washing process.

(aluminum or aluminum alloy material)

The aluminum or aluminum alloy material targeted by the surface treatment agent is not particularly limited, but is particularly effective for an aluminum die-cast material having a thick surface oxide film and segregating alloy components. The use of the aluminum or aluminum alloy material is not particularly limited, but examples thereof include marine propulsion engines and their peripheral equipment, internal combustion engine parts for motorcycles, and the like.

(degreasing process)

In the production method of the present embodiment, it is preferable to perform a degreasing step of contacting a known degreasing agent on the surface or surface of aluminum or aluminum material before performing the contact step. Although the degreasing method is not specifically limited, For example, solvent degreasing, alkali degreasing, etc. are mentioned.

(contact process)

In the contact step in the manufacturing method of the present embodiment, the contact temperature and contact time are not particularly limited, but usually, the surface treatment agent is applied on the surface or surface of aluminum or aluminum alloy material at 30 to 80 ° C., preferably It is made to contact for 10 to 600 second at 40-70 degreeC. In addition, after the said process, if necessary, you may wash with water, wash with deionized water, and then dry. The drying temperature is not particularly limited, but is preferably 50 to 140°C. In addition, the method of bringing the surface treatment agent into contact with the surface or surface of the aluminum or aluminum alloy material is not particularly limited, but examples thereof include a dipping method, a spray method, and a flow coating method.

(4) Aluminum or aluminum alloy material with surface treatment film

An aluminum or aluminum alloy material having a surface treatment film manufactured by the above production method is another embodiment of the present invention. The coating amount of the surface treatment film on the aluminum or aluminum alloy material is not particularly limited, but the total mass of Cr, Ti and/or Zr and Zn contained in the surface treatment film is 1 to 200 mg/m 2 per unit area. desirable.

The aluminum or aluminum alloy material having a surface-treated film of the present embodiment has excellent corrosion resistance even without performing a painting process of coating the surface-treated film, and has excellent corrosion resistance even when the film is exposed to high temperatures. may be carried out.

The coating step is not particularly limited, but can be carried out by, for example, a coating method such as water-based coating, solvent coating, powder coating, anion electrodeposition coating, cationic electrodeposition coating, etc. using a known coating composition. .

Example

Hereinafter, Examples and Comparative Examples of the present invention will be described. In addition, this invention is not limited to the said Example.

<Aluminum material>

Aluminum die-cast material (JIS-ADC12)

<surface treatment agent>

The supply sources shown in Tables 1 to 5 were mixed with water to obtain surface treatment agents of Examples 1 to 20 and Comparative Examples 1 to 3 in which the concentration of each ion is the value shown in Table 6. In addition, ammonia water was used as a pH adjuster. In addition, the free fluorine ion concentration was measured using a commercially available fluorine ion meter [ion electrode: fluoride ion composite electrode F-2021 (manufactured by Toa DK Co., Ltd.)].

<<Manufacture of aluminum die-cast material having surface treatment film>>

Using the surface treatment agents of Examples 1 to 20 and Comparative Examples 1 to 3, aluminum die-cast materials having surface-treated coatings were produced, and test pieces 1 to 23 were obtained.

Specifically, the aluminum die-cast material was immersed at 60°C for 2 minutes in an alkali degreasing agent [a 20 g/L aqueous solution of Fine Cleaner 315E (manufactured by Nihon Parkerizing Co., Ltd.)], and then washed and cleaned the surface with tap water. After that, the contact step was performed by spraying the surface treatment agent on the surface or the surface of the aluminum die-cast material at the contact temperature shown in Table 6. After that, it was washed with running tap water (room temperature - 30 seconds), washed with deionized water (room temperature - 30 seconds), and then dried in an electric oven (80 ° C - 5 minutes) to obtain an aluminum die-cast material having a surface treatment film ( Test pieces 1 to 23) were prepared. The total mass of Cr, Ti and/or Zr, Zn contained in the surface treatment film was measured with respect to the adhesion amount of the surface treatment film of test pieces 1 to 23, using a scanning-type fluorescence X-ray analyzer [ZSXprimus II (manufactured by Rigaku Co., Ltd.)] was measured using Table 7 shows the measurement results.

In addition, each test was performed for test pieces 1 to 23 as shown below, and the corrosion resistance of the surface treatment film and the corrosion resistance after heating were evaluated. The results are shown in Table 8.

≪Evaluation method≫

<corrosion resistance>

A neutral salt spray test (JIS-Z2371: 2015) was performed on test pieces 1 to 23 for 240 hours. After drying, the ratio of white rust generated on the surface of the test piece was visually measured. The ratio of white rust is the ratio of the area where white rust occurs to the area of the observation site. The evaluation criteria are as follows. An evaluation result is shown in Table 8.

<Evaluation Criteria>

5 White rust ratio 10% or less

4 White rust ratio more than 10% to 30% or less

3 White rust ratio more than 30% to 50% or less

2 White rust ratio more than 50% to 70% or less

1 White rust ratio over 70%

<Corrosion resistance after heating>

After heating each test piece in an electric oven (180°C - 20 minutes), a neutral salt spray test (JIS-Z2371: 2015) was conducted for 240 hours. After drying, the ratio of white rust generated on the surface of the metal material was visually measured. The ratio of white rust is the ratio of the area where white rust occurs to the area of the observation site. The evaluation criteria are as follows. An evaluation result is shown in Table 8.

<Evaluation Criteria>

5 White rust ratio 10% or less

4 White rust ratio more than 10% to 30% or less

3 White rust ratio more than 30% to 50% or less

2 White rust ratio more than 50% to 70% or less

1 White rust ratio over 70%

Claims (3)

An ion (A) containing trivalent chromium, at least one ion (B) selected from ions containing titanium and ions containing zirconium, an ion (C) containing zinc, and a free fluorine ion ( D) and a surface treatment agent containing nitrate ions (E) and used for surface treatment of aluminum or aluminum alloy materials,
A surface treatment agent that does not contain a compound having an aromatic ring. A method for producing an aluminum or aluminum alloy material having a surface treatment film, comprising a contact step of bringing the surface treatment agent according to claim 1 into contact with the surface or surface of the aluminum or aluminum alloy material. An aluminum or aluminum alloy material having a surface-treated film obtained by the production method according to claim 2.