TWI428468B - A metal surface treatment agent, a metal surface treatment method, and a metal material containing the metal surface treatment agent - Google Patents

Description

Metal surface treatment agent, metal surface treatment method and metal material containing the metal surface treatment agent

The present invention relates to a surface treatment agent, a surface treatment method, and a metal material including a surface treatment agent, particularly a metal surface treatment agent, a metal surface treatment method, and a metal material containing the metal surface treatment agent.

Surface-treated metal materials (such as galvanized steel sheets) have good corrosion resistance, easy molding, welding and painting, and are widely used in home appliances, electronic products, machinery and construction industries. However, in the case of the conventional galvanized steel sheet, after a period of use, the galvanized layer of the conventional galvanized steel sheet is corroded in the air (especially in a high-humidity heat environment) to form white rust, so the steel sheet is plated. After passivation, surface passivation treatment is required.

The prior art documents of several conventional metal surface treatments are exemplified below.

1. Republic of China Patent Notice No. TW 506996:

Method: A metal surface treatment agent comprising (A) a vanadium compound and (B) a metal compound containing at least one metal selected from the group consisting of zirconium, titanium, molybdenum, tungsten, manganese or cerium. In the examples of the patent, in addition to the above (A) and (B), an etchant (HF, H ₂ ZrF ₆ , CH ₃ COOH, H ₂ SiF ₆ ) is added, and the vanadium-containing compound is mainly used. +5 vanadium compound.

Disadvantages: The patented metal surface treatment agent found 10 to 30% of white rust occurrence area after 48 hours of corrosion resistance test. It is obvious that the patented treatment agent cannot effectively improve corrosion resistance. In addition, the treatment agent of this patent requires a complicated procedure in preparation, and the solubility and stability in the treatment agent are still degraded.

2. Republic of China Patent Application No. 098114631:

Method: A metal surface treatment agent comprises an organic vanadium compound and a phosphorus-containing inorganic acid, wherein the vanadium ion oxidation number in the organic vanadium compound is not +5. A protective film is formed on the surface of the surface-treated metal material, and the protective film has good adhesion to the surface of the metal material, and has better corrosion resistance and high temperature resistance.

Disadvantages: However, after the above-mentioned surface-treated metal material was treated with alkali-eluting grease, the corrosion resistance test after alkali washing was found for 24 hours, and the problem of 100% white rust formation was found. It is obvious that the treatment agent of the patent does not have alkali-resistant washing property. .

Therefore, it is necessary to provide an innovative and progressive metal surface treatment agent, a metal surface treatment method, and a metal material containing the metal surface treatment agent to solve the above problems.

The present invention provides a metal surface treatment agent comprising: a vanadium compound in which the vanadium ion oxidation number is not +5; an organic compound having a C=O functional group, and the content of the organic compound is 100 parts by mass relative to the vanadium compound 65 to 260 parts by mass; and a metal compound selected from the group consisting of a compound containing aluminum, magnesium, manganese or calcium, or a group thereof, the content of the metal compound being 100 parts by mass relative to the vanadium compound 10 to 90 parts by mass.

The present invention further provides a metal surface treatment method for forming a metal surface treatment agent as described above on a surface of a metal body.

The present invention further provides a metal material comprising a metal body and a metal surface treatment agent as described above, the metal surface treatment agent being formed on a surface of the metal body.

The metal surface treatment agent, the metal surface treatment method and the metal material containing the metal surface treatment agent can effectively block the invasion of the corrosion factor, and the metal material having the metal surface treatment agent can have good corrosion resistance and resistance at the same time. Alkali washability and high temperature discoloration.

The metal surface treatment agent of the present invention includes a vanadium compound, an organic compound, and a metal compound. The vanadium ion oxidation number is not +5. The vanadium compound is selected from the group consisting of VOSO ₄ , VCl ₃ , VCl ₄ , V ₂ O ₃ , V ₂ O ₄ , V(C ₅ H ₇ O ₂ ) ₃ or VO(C ₅ H ₇ O ₂ ) ₂ , or A group of vanadium compounds. Wherein, VOSO ₄ , VCl ₃ , VCl ₄ , V ₂ O ₃ , V ₂ O ₄ are inorganic vanadium compounds, and V(C ₅ H ₇ O ₂ ) ₃ or VO(C ₅ H ₇ O ₂ ) ₂ is an organic vanadium compound. . In other words, the vanadium compound may be selected from an inorganic vanadium compound or an organic vanadium compound.

The organic compound has a C=O functional group. Preferably, the content of the organic compound is 65 to 260 parts by mass based on 100 parts by mass of the vanadium compound. When the content of the organic compound is less than 65 parts by mass, the corrosion resistance of the formed protective film is not good; when the content is more than 260 parts by mass, the formed protective film is deteriorated in moisture absorption resistance and high temperature discoloration resistance. situation.

The functional group of the organic compound may be selected from a combination of a carbonyl group, a carboxyl group or the like. The organic compound may be selected from the group consisting of 2,4-pentanedione, acetic acid, citric acid, maleic acid or lactic acid, or the like. The infrared absorption spectrum of the organic compound ranges from 1600 to 1800 cm ^-1 .

The metal compound is selected from the group consisting of compounds containing aluminum, magnesium, manganese or calcium, or the like. Preferably, the content of the metal compound is from 10 to 90 parts by mass based on 100 parts by mass of the vanadium compound. When the content of the metal compound is less than 10 parts by mass, the effect of improving the alkali-resistant washing property of the metal surface is not good; when the content is more than 90 parts by mass, although the alkali-resistant alkali-washing property of the metal surface is effectively improved, it may cause The corrosion resistance of the formed protective film is remarkably deteriorated.

The metal element of the metal compound is at least one of aluminum, magnesium, manganese and calcium. In one embodiment of the present invention, the metal compound is selected from the group consisting of aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum oxide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium oxalate, magnesium oxide, manganese sulfate, manganese nitrate, and acetic acid. a group consisting of manganese, manganese oxide, calcium sulfate, calcium nitrate, calcium acetate or calcium oxide, or the like.

Preferably, the metal surface treatment agent further comprises a decane coupling agent. The decane coupling agent can be any decane coupling agent used to treat metal surfaces. After the hydrolysis and condensation, the decane coupling agent forms a chemical bond with the metal surface to form Si-OM (M represents a metal), so that the metal surface treatment agent and the metal surface have good adhesion, so that the metal surface treatment agent The overall structure is more compact.

The content of the decane coupling agent is preferably 65 to 260 parts by mass based on 100 parts by mass of the vanadium compound. When the content of the decane coupling agent is less than 65 parts by mass, although a protective film is still formed on the surface of the metal material, the corrosion resistance and adhesion of the protective film are not good; when the amount of the decane coupling agent exceeds 260 mass At the time of the dispersion, the solubility of the metal surface treatment agent is poor to cause precipitation, and the high temperature resistance of the protective film may also become poor.

Preferably, the decane coupling agent is selected from the group consisting of γ-aminopropyltrimethoxydecane, γ-aminopropyltriethoxydecane, γ-propylene oxide propyltrimethoxy decane, γ-epoxy Propyl propyl triethoxy decane, N-β (aminoethyl)-γ-aminopropylmethyldiethoxy decane, N-β(aminoethyl)-γ-aminopropyl A group consisting of trimethoxydecane, N-β (aminoethyl)-γ-aminopropyltriethoxydecane, and γ-propylene oxide propylmethyldiethoxydecane.

Preferably, the metal surface treatment agent has a pH of from 1.5 to 5.0. When the pH is lower than 1.5, the corrosion resistance of the protective film formed on the metal surface by the metal surface treatment agent is not affected, and the surface appearance is affected; and when the pH is higher than 5.0, the metal surface treatment agent is less. It is stable and easily forms a precipitate. The metal surface treatment agent can adjust the pH in various ways, for example, by using an alkali solution as needed.

The present invention further provides a metal surface treatment method for forming a metal surface treatment agent as described above on a surface of a metal body. In various applications, the metal body may be selected from the group consisting of aluminum, zinc, galvanized steel or galvanized aluminum. Preferably, before the metal surface treatment agent is formed on the surface of the metal body, the metal surface treatment method of the present invention may further comprise a cleaning and degreasing step to clean the metal surface, and further, the metal surface may be reheated and dried. Treatment agent. Preferably, the temperature of the heat drying step is 50 to 250 °C.

After the metal body is subjected to the above metal surface treatment method, the metal material of the present invention can be obtained, wherein the metal surface treatment agent is disposed on the surface of the metal body to form the protective film.

Preferably, in the metal material of the present invention, the amount of the vanadium compound on the surface of the metal body is 1 to 20 mg/m ² . In other words, the surface of the metal body has a vanadium compound adhesion amount of 1 to 20 mg/m ^{2 in terms} of vanadium. When the adhesion amount of the vanadium compound on the surface of the metal body is less than 1 mg/m ² , although the protective film can still form a protective film, the corrosion resistance and the alkali-resistant washing property of the protective film are not good; When the amount of adhesion on the surface of the metal body is higher than 20 mg/m ² , the solubility of the metal surface treatment agent may be poor to cause precipitation.

Preferably, the protective film has a thickness of 0.05 to 2 μm. More preferably, the protective film has a thickness of 0.1 to 1 μm. When the thickness of the protective film is less than 0.05 μm, the corrosion resistance and adhesion of the protective film will be poor; when the thickness of the protective film exceeds 2 μm, although the corrosion resistance can be improved, the appearance of the metal material will not be caused. Good and increase production costs.

The corrosion process of metal materials is caused by the infiltration of corrosion factors (oxygen, water, chloride ions, etc.) on the metal surface, which induces the electrochemical redox reaction, that is, in the cathode reaction, oxygen, water, etc. get electrons and generate OH ^-, that the OH ^- concentration increased, the anode reaction material lost electrons due to the metal to form a metal ion. Therefore, in order to improve the corrosion resistance of a metal material (for example, a galvanized steel sheet), it is conceivable to suppress the oxidation-reduction reaction of the anode and the cathode.

In the present invention, the metal surface treatment agent is used to suppress the redox reaction of the anode and the cathode. Wherein, after heating and drying, the vanadium ions in the organic vanadium compound will be converted into vanadium oxide (the vanadium oxide has better hydrolysis resistance than the oxide formed by the +5-valent vanadium ion), and The ligand in the organovanadium compound will chelate with the metal ion of the metal body, and form an insoluble and stable organometallic chelate on the metal surface, thereby effectively preventing the invasion of the corrosion factor. The excess organic compound can further react with the metal ions of the metal material to form a poorly soluble and stable organometallic chelate on the surface of the metal material to slow the corrosion. Further, in the alkali washing process, the metal compound generates a poorly soluble product by reacting with a hydroxyl group to inhibit the action of the hydroxyl group to damage the protective film or to infiltrate the surface of the metal material, thereby reducing the surface corrosion reaction after the alkali washing treatment.

Therefore, the metal surface treatment agent, the metal surface treatment method and the metal material containing the metal surface treatment agent of the invention can effectively block the invasion of the corrosion factor, and at the same time, the metal material surface has good corrosion resistance and alkali-resistant washing property, and The formed protective film also has high temperature discoloration resistance.

The invention is illustrated in the following examples and comparative examples, but is not intended to limit the invention to the invention.

Example:

The common method of examples 1~11 (hereafter labeled E1~E11):

1. Metal surface treatment agent:

According to the content and composition of Table 1, the vanadium compound, the organic compound, the metal compound and the selectively added decane coupling agent are respectively mixed, and then added with water and stirred uniformly to obtain the metal surface treatment agents of Examples 1 to 11, respectively. .

2. Surface treated metal materials:

A metal body (hot dip galvanized steel sheet, GI) was taken, and the surface was subjected to alkali degreasing treatment, water washing and drying, and then the surface of the metal obtained by the above was treated with a #3 bar coater (RDS No. 3). The agent is applied to the surface of the metal body, and the metal body coated with the metal surface treatment agent is placed in a heat cycle type oven, and dried at a plate temperature of 100 ° C, respectively, and dried for a period of time, that is, respectively, an example 1 is prepared. ~11 surface treated metal material.

The common method of Comparative Examples 1 to 4 (hereinafter referred to as C1 to C4):

1. Metal surface treatment agent:

Except for changing the composition and amount according to Table 1, the other preparation processes were the same as those of Examples 1 to 11, and finally the metal surface treatment agents of Comparative Examples 1 to 4 were respectively prepared.

2. Surface treated metal materials:

Except for the metal surface treatment agents of Comparative Examples 1 to 4, respectively, the other preparation processes were the same as those of Examples 1 to 11, and finally the surface-treated metal materials of Comparative Examples 1 to 4 were respectively obtained.

In Table 1, A1 is vanadium sulphate; B1 is 2,4-pentanedione; C1 is aluminum nitrate; C2 is magnesium nitrate; C3 is manganese sulfate; and D1 is γ-aminopropyltriethoxydecane. Among them, the values in the parentheses in A1, B1, C1, C2, C3, and D1 indicate the mass parts they contain.

[test]

The steel sheets (metal materials) obtained in the above Examples 1 to 11 and Comparative Examples 1 to 4 were respectively subjected to the following tests, and the results are shown in Table 2:

1. Corrosion resistance: The salt spray test using the standard method of JIS Z-2371 was carried out, and the area of white rust on the surface of the steel sheet was visually evaluated after 72 hours of the test, and the smaller the area where white rust occurred, the better the corrosion resistance. If the area of white rust is ≧50%, it is judged that the corrosion resistance is not good, and it is marked as “×”; if 30% ≦ white rust occurs in area ≦50%, it is judged that the corrosion resistance is poor, and it is marked as “△”; if 10% ≦ white rust When the occurrence area is ≦30%, it is judged that the corrosion resistance is acceptable, and it is marked as "○": If the white rust occurrence area is <10%, the corrosion resistance is judged to be good, and it is indicated as "◎".

2. Alkali-resistant washing property: The surface-treated steel sheet prepared above was immersed in an alkali-releasing fat agent Parclean 364S (20 g/L) manufactured by Baccarat, Japan, and adjusted to a degreasing agent aqueous solution at 65 ° C for 2 minutes. After washing, it is dried by cold air. Subsequently, the salt spray test using the standard method of JIS Z-2371 was carried out, and the area of white rust on the surface of the steel sheet was visually evaluated 48 hours after the test, and the smaller the area where the white rust occurred was, the better the alkali-resistant washing property after the alkali washing. If the area of white rust is ≧50%, it is judged that the alkali-resistant washing property is not good, and it is marked as “×”; if the area of 5% white rust is ≦50%, it is judged that the alkali-resistant washing property is poor, and it is marked as “△”; When the area of occurrence of white rust is ≦30%, it is judged that the alkali-resistant washing property is acceptable, and it is marked as "○": If the white rust occurrence area is <10%, it is judged that the alkali-resistant washing property is good, and it is marked as "◎".

3. High temperature discoloration property: After the surface-treated steel sheet obtained above was allowed to stand in a high temperature environment (450 ° C) for 5 minutes, the surface of the protective film was visually evaluated for high temperature resistance. The evaluation criteria are as follows:

◎: The appearance of the protective film after the high temperature test was the same as that of the protective film (original protective film) which was not subjected to the high temperature test.

○: The appearance of the protective film after the high temperature test was slightly different from that of the original protective film.

△: After the high temperature test, the appearance of the protective film has a yellowing or darkening appearance compared with the appearance of the original protective film.

×: After the high temperature test, the appearance of the protective film has a yellowish or darkened appearance compared with the appearance of the original protective film, and there is a clear crack path at the surface of the protective film.

It can be seen from the results of Table 2 that the steel sheets obtained in Examples 1 to 11 have good corrosion resistance, alkali-resistant washing resistance and high temperature discoloration resistance; in contrast, the steel sheets obtained in Comparative Examples 1 to 4 have poorer properties. Corrosion resistance, alkali wash resistance and high temperature discoloration resistance.

When Example 6 was compared with Comparative Example 1, it was found that Example 6 had considerably excellent corrosion resistance, alkali wash resistance and high temperature discoloration resistance, and the properties of Comparative Example 1 were significantly inferior. This is because Comparative Example 1 does not have a decane coupling agent, so that the denseness of the protective film cannot be improved, so that the formed protective film and the surface of the metal substrate cannot have good corrosion resistance. Further, in Comparative Example 1, the addition of the metal compound resulted in poor alkali-resistant washing performance.

When the case 7 was compared with the comparative example 2, it was found that the organic compound and the metal compound were not added in the comparative example 2, so that the corrosion resistance and the alkali-washing resistance were remarkably poor, and the high temperature discoloration resistance was poor due to the addition of the excess decane coupling agent. .

When Comparative Example 3 was compared with Comparative Example 3, Comparative Example 3 showed significant deterioration in corrosion resistance before and after alkali washing due to the addition of an excessive amount of the metal compound.

When Example 9 was compared with Comparative Example 4, Comparative Example 4 added only a vanadium compound, and no organic compound was added, so that an organometallic compound could not be formed with a metal ion, and a metal compound or a decane coupling agent was not added, so that it was formed. Good corrosion resistance and alkali-resistant washability between the protective film and the surface of the metal material

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the scope of the present invention. The scope of the invention should be as set forth in the appended claims.

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Claims (14)

A metal surface treatment agent comprising: a vanadium compound, wherein the vanadium ion oxidation number is not +5; and an organic compound having a C=O functional group, and the content of the organic compound is 65~ relative to 100 parts by mass of the vanadium compound. 260 parts by mass, the infrared absorption spectrum of the organic compound is in the range of 1600 to 1800 cm ^-1 ; and a metal compound selected from the group consisting of a compound containing aluminum, magnesium, manganese or calcium, or a group thereof, the metal compound The content is 10 to 90 parts by mass based on 100 parts by mass of the vanadium compound. The metal surface treatment agent according to claim 1, wherein the organic vanadium compound is selected from the group consisting of VOSO ₄ , VCl ₃ , VCl ₄ , V ₂ O ₃ , V ₂ O ₄ , V(C ₅ H ₇ O ₂ ) ₃ or VO. (C ₅ H ₇ O ₂ ) ₂ , or a group of such vanadium compounds. The metal surface treatment agent of claim 1, wherein the functional group of the organic compound is selected from the group consisting of a carbonyl group, a carboxyl group, or the like. The metal surface treatment agent of claim 1, wherein the organic compound is selected from the group consisting of 2,4-pentanedione, acetic acid, citric acid, maleic acid or lactic acid, or the like. The metal surface treatment agent according to claim 1, wherein the metal element of the metal compound is at least one of aluminum, magnesium, manganese and calcium. The metal surface treatment agent according to claim 5, wherein the metal compound is selected from the group consisting of aluminum sulfate, aluminum nitrate, aluminum acetate, aluminum oxide, magnesium sulfate, magnesium nitrate, magnesium acetate, magnesium oxalate, magnesium oxide, manganese sulfate, and manganese nitrate. , manganese acetate, manganese oxide, calcium sulfate, calcium nitrate, calcium acetate or calcium oxide, or The group formed by the group. The metal surface treatment agent of claim 1 further comprising a decane coupling agent in an amount of from 65 to 260 parts by mass based on 100 parts by mass of the vanadium compound. The metal surface treatment agent according to claim 7, wherein the decane coupling agent is selected from the group consisting of γ-aminopropyltrimethoxydecane, γ-aminopropyltriethoxydecane, and γ-propylene oxide propyl. Trimethoxy decane, γ-propylene oxide propyl triethoxy decane, N-β (aminoethyl)-γ-aminopropyl methyldiethoxy decane, N-β (aminoethyl) )-γ-aminopropyltrimethoxydecane, N-β(aminoethyl)-γ-aminopropyltriethoxydecane or γ-propylene oxide propylmethyldiethoxydecane , or a group of such groups. The metal surface treatment agent of claim 1 has a pH of from 1.5 to 5.0. A metal surface treatment method for forming a metal surface treatment agent according to claim 1 on a surface of a metal body. The metal surface treatment method of claim 10, wherein the metal system is selected from the group consisting of aluminum, zinc, galvanized steel, or galvanized aluminum. The metal surface treatment method of claim 10, further comprising a heat drying step, wherein the temperature of the heat drying step is 50 to 250 °C. A metal material comprising a metal body and a metal surface treatment agent according to claim 1, wherein the metal surface treatment agent is formed on a surface of the metal body. The metal material of claim 13, wherein the amount of the vanadium compound on the surface of the metal body is 1 to 20 mg/m ² .