JP2001098392A - Rust-prevention treated metal, composition for rust preventive film deposition and rust preventive film deposition method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rust-prevention treated metal in which rust preventive films which maintains rust preventability are deposited on the surface of a metallic substrate. SOLUTION: By a rust preventively treated metal provided with a first rust preventive film essentially consisting of tannic acid and deposited so as to tightly be adhered onto the surface of a metallic substrate, a second rust preventive film mainly containing metallic ions and/or metallic compounds and deposited on the upper layer part of the first rust preventive film and, if required, with a third rust preventive film essentially consisting of tannic acid and deposited so as to tightly be adhered onto the second rust preventive film as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust-preventive metal having a rust-preventive film having excellent rust-preventive properties formed on the surface of a metal substrate, a composition for forming a rust-preventive film, and the formation of a rust-proof film using the same It is about the method.

[0002]

2. Description of the Related Art Conventionally, in order to protect the surface of a metal substrate, prevent the generation of rust, and improve the functionality and decorativeness, a conventional method has been proposed.
There are many methods of performing a chemical conversion treatment with a treatment liquid containing chromium (V), or performing a surface treatment with a treatment liquid containing hexavalent chromium after plating.

[0003] This hexavalent chromium is excellent in rust prevention and is relatively easy to treat, and the rust prevention film formed by hexavalent chromium can damage the surface of the metal substrate such as scratches. Even though the film is regenerated, the film has a so-called self-healing effect, but hexavalent chromium is extremely toxic and has a large effect on the environment.

[0004] Therefore, as a method of treating with a treatment solution containing no hexavalent chromium, for example, JP-A-48-27936, JP-A-51-71233, and JP-A-52-5-5
4630, JP-A-52-141440, JP-A-53-19149, and JP-A-53-37150.
JP, JP-A-53-116240, JP-A-54-116240
JP-A-110941, JP-A-55-148773, JP-A-55-62173, JP-A-57-16
No. 177, JP-A-58-197285, JP-A-59-116381 and the like disclose an organic protection using a treatment solution containing tannic acid or a treatment solution containing tannic acid and other components. A rust film treatment has been proposed, and Japanese Patent Application Laid-Open Nos. Sho 56-43384, 52-9236 and 57-145987.
Patent Publication, Japanese Patent Application Laid-Open No. 9-53192, etc., have proposed a surface treatment using an alternative metal to hexavalent chromium.
Compared to the surface treatment containing hexavalent chromium, which has been performed conventionally,
At present, corrosion resistance is not sufficient, and even if scratches or the like occur in the film, self-healing properties are not seen, so that practical use has hardly been achieved.

Japanese Patent Application Laid-Open No. 49-47224 discloses a process in which a metal surface is contacted with a phosphate-containing composition for treatment, and the contact-treated surface is sufficiently treated to impart corrosion resistance and moisture resistance. A metal surface treatment method comprising a step of contacting the composition with a composition containing a natural vegetable tannin has been proposed, but the rust prevention property, that is, the corrosion resistance is not sufficiently improved. At present, it has hardly been used because there is no rust-preventing effect such as scratches on the surface of the metal substrate due to the absence of such a material.

[0006]

SUMMARY OF THE INVENTION The first object of the present invention is to provide a metal substrate having a surface equivalent to hexavalent chromium without using harmful chemicals such as hexavalent chromium which affect the environment. A second object of the present invention is to provide a rust-preventive metal having a rust-preventive film having excellent rust-preventive property and maintaining the rust-preventive property even if scratches or the like are generated in the rust-preventive film. The object of the present invention is to provide a composition for forming a rust-preventive film used to easily obtain the rust-preventive metal of the present invention,
A third object of the present invention is to provide a method for forming a rust preventive film for easily obtaining the rust preventive treated metal of the present invention by treating the surface of a metal substrate using the composition for forming a rust preventive film of the present invention. It is to be.

[0007]

According to the present invention, as a result of intensive studies to solve the problems of the prior art, for example, a first rust preventive film mainly composed of tannic acid is first formed on the surface of a metal substrate. Then, by forming a second rust-preventive film mainly containing metal ions and the like on the upper layer of the first rust-preventive film, for example, the upper layer including the surface of the first rust-preventive film mainly composed of tannic acid is formed. The second rust preventive film is formed by adsorption, sorption and chemical bonding of metal ions and the like, and the synergistic effect of these rust preventive films significantly improves the rust preventive property, and the rust preventive film is damaged. The present inventors have found that the rust-preventive property is maintained even if such damage is caused, and thus the present invention has been accomplished.

According to the first aspect of the present invention, there is provided a first rust preventive film mainly composed of tannic acid formed in close contact with the surface of a metal substrate, and an upper layer formed on the first rust preventive film. Rust-preventive film mainly containing metal ions and / or metal compounds, and if necessary, a third rust-preventive film mainly composed of tannic acid formed in close contact with the second rust-preventive film. A fourth rust-preventive film mainly containing metal ions and / or metal compounds formed on the upper part of the third rust-preventive film, if necessary. The present invention relates to a rust-proof metal, wherein at least one similar rust-proof film is provided in close contact with the fourth rust-proof film.

[0009] The invention described in claim 2 of the present invention is claim 1.
In the rust-proofing metal according to the above, the metal substrate is zinc,
It has a metal surface selected from the group consisting of nickel, aluminum, magnesium, copper, iron and alloys thereof.

The third aspect of the present invention is the first aspect of the present invention.
Alternatively, in the rustproofing metal according to claim 2, the metal ions are Al, Cu, Fe, Ni, Mo, V, T
a mixture of one or more metal ions of i, W, Zn, and Zr, wherein the metal compound is a mixture of one or more metal compounds containing these metals. Things.

According to a fourth aspect of the present invention, there is provided a first treatment solution containing tannic acid for treating the surface of a metal substrate, and a metal ion for successively treating the surface treated with the first treatment solution. And / or a second treatment liquid containing a metal compound.

The invention according to claim 5 of the present invention is the invention according to claim 4.
In the composition for forming a rust-preventive film according to the above, the concentration of tannic acid in the first treatment liquid is in the range of 0.1 to 30 g / l, and p
H is in the range of 3.5 to 8.0.

The invention according to claim 6 of the present invention is the invention according to claim 4.
Alternatively, in the composition for forming a rust-preventive film according to claim 5, the pH of the second treatment liquid is in the range of 2.0 to 10.0.

According to a seventh aspect of the present invention, a fourth aspect is provided.
Alternatively, the surface of the metal substrate is treated with the first treatment liquid according to claim 5 to form a first rust-preventive film mainly composed of tannic acid in close contact with the surface of the metal substrate, and if necessary, washing with water,
Subsequently, a second rust preventive film mainly containing a metal ion and / or a metal compound is formed on the first rust preventive film by treating with the second processing solution according to claim 4 or 6, and then washed with water. And a method for forming a rust preventive film characterized by drying.

The invention according to claim 8 of the present invention is the invention according to claim 7
In the method for forming a rust preventive film according to the above, after forming the second rust preventive film, the rust preventive film is treated with the first treatment liquid according to the claim 4 or 5 and adheres onto the second rust preventive film to mainly use tannic acid. After forming a third rust-preventive film to be washed with water and dried,
Alternatively, after the washing, if necessary, the fourth treatment solution is treated with the second treatment solution according to claim 4 or claim 6, and the fourth rust prevention film mainly containing metal ions and / or metal compounds in the upper layer of the third rust prevention film. After forming a rust film, wash with water and dry or, if necessary,
After forming at least one rust preventive film on the rust preventive film, the film is washed with water and dried.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. FIG. 1 is a schematic view showing the results of analyzing the cross section of an embodiment of the rust-proofed metal of the present invention in the thickness direction of the rust-proof coating (hereinafter referred to as XPS analysis) using X-ray photoelectron spectroscopy. FIG. FIG. 2 is an explanatory view schematically showing the result of XPS analysis of the cross section of another embodiment of the rustproofing metal of the present invention in the same manner. In FIG. 1, a rust-preventive metal 1 of the present invention comprises a first rust-preventive film 3 mainly composed of tannic acid formed in close contact with the surface of a metal substrate 2 and a surface of the first rust-preventive film 3. Metal ions formed on the upper layer portion containing
Alternatively, a second rust preventive film 4 mainly containing a metal compound is provided.

The tannic acid used in the present invention is a gallotannin having a complex molecular structure based on polyoxyphenyl, and is not necessarily a pure substance. The crude substance is called tannin. Specific examples thereof include, for example, depsid, tannins from China, tannins from Turkey, hamameli tannins, sumac tannins, kepric acid, quintuple tannins, ellagic acid tannins, catechins, catechus, gambia, quebracho tannins, etc. Species or a mixture of two or more kinds. In the present invention, commercially available tannic acid can be used.

The material of the surface of the metal substrate 2 is not particularly limited, but specific examples include metals selected from the group consisting of zinc, nickel, aluminum, magnesium, copper, iron, and alloys thereof. . The metal base 2 may be formed of these metals themselves, or the main body of the metal base 2 may be formed of another metal or a material such as ceramic. These metal layers may be formed by a method such as the above method or a lamination method, or a combination thereof.

The metal ion is not particularly limited. Specifically, for example, Al, Cu, Fe, Ni, Mo,
One or two metal ions of V, Ti, W, Zn, Zr
Mixtures of more than one species can be mentioned. The metal compound is one or a mixture of two or more metal compounds containing these metals.

Examples of the metal compound include a metal compound such as a molybdate compound, a vanadate compound, a titanate compound, a tungstate compound, a zirconate compound, a metal oxide containing the metal, and a metal oxide. Or a mixture of two or more kinds of fluorine metal compounds containing

As the molybdate compound, for example, ammonium molybdate, sodium molybdate and the like can be used.

As the vanadic acid compound, for example,
Ammonium vanadate, sodium vanadate and the like can be used.

As the tungstate compound, for example, ammonium tungstate, sodium tungstate and the like can be used.

As the titanate compound and zirconate compound, for example, similarly to various alkali metal salts, halogen compounds can also be used.

The first tannic acid shown in FIG.
In order to form the rust preventive film 3 in close contact with the surface of the metal substrate 2, first, the surface of the metal substrate 2 is treated with a first treatment liquid containing tannic acid. The concentration and pH of tannic acid in the first treatment liquid are not particularly limited, but the concentration of tannic acid is preferably 0.1 to 30 g / l, more preferably 0.5 to 30 g / l.
25 g / l and the pH is preferably between 3.5 and
8.0, and more preferably in the range of 4.0 to 7.0.

If the concentration of tannic acid is less than 0.1 g / l, there is a possibility that a tannic acid film having good corrosion resistance may not be obtained. The effect of can not be expected.

The temperature of the first processing solution is about 10
~ 50 ° C is desirable. If the temperature is lower than 10 ° C., the reaction rate may be slow and a sufficient film may not be formed. If the temperature is higher than 50 ° C., organic substances may be decomposed, and the processing solution may be largely evaporated, which is uneconomical. Further, the processing time with the first processing liquid is desirably about 15 to 180 seconds. If the time is less than 15 seconds, the formation of the rust-preventive film may be insufficient. If the time exceeds 180 seconds, no further effect can be expected in the reduction of the treatment concentration and the rust-preventive performance.

When the pH of the first treatment liquid is lower than 3.5 or higher than 8.0, the formed rust-preventive film is easily redissolved.

The pH of the first processing solution can be adjusted using an alkaline substance or an acidic substance. Examples of the alkaline substance for pH adjustment include sodium hydroxide, potassium hydroxide, and aqueous ammonia. Examples of the acidic substance include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, and organic acids. And organic carboxylic acids.

The thickness of the first rust preventive film 3 obtained by treating with the first treating solution is not particularly limited. However, when treated under the above treatment conditions, the first rust preventive film 3 having a thickness of about 0.05 to 0.3 μm, which is in good contact with the metal substrate 2, can be obtained.

Next, in order to form the second rust-preventive film 4 on the upper layer including the surface of the first rust-preventive film 3 formed as described above, it is preferable that the second rust-preventive film 4 be treated immediately with the first treatment liquid. Is treated with the first treatment liquid and then washed with water to substantially rinse the first treatment liquid from above the first rust-preventive film 3, and then the surface of the first rust-preventive film 3 is washed with metal ions and / or metal compounds. The treatment is performed with the contained second treatment liquid. After processing with the second processing solution,
After the second treatment liquid is substantially washed off from the second rust-preventive film 4 by washing with water, the rust-proof treated metal 1 of the present invention can be obtained by finishing by drying.

Although the pH of the second processing solution is not particularly limited,
The pH is preferably in the range of 2.0 to 10.0, more preferably adjusted to 3.5 to 8.0. Second
When the pH of the treatment liquid is lower than pH 2.0 or higher than 10.0, the formed rust-preventive film is easily redissolved.

The content of metal ions and / or metal compounds in the second treatment liquid is not particularly limited, but the content is preferably 0.01 to 50 g / l in terms of metal ions.
More preferably, it is 0.1 to 30 g / l. 0.0
If it is less than 1 g / l, rust prevention may be inferior, and 50 g / l
Even if it exceeds 1, there is a possibility that the rust prevention property is not further improved and it becomes uneconomical.

The pH of the second processing solution is preferably adjusted using an acidic substance or an alkaline substance. As alkaline substances for pH adjustment, sodium hydroxide, potassium hydroxide,
Examples of lithium hydroxide, aqueous ammonia, and the like, and examples of the acidic substance include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, organic acids, and organic carboxylic acids.

The processing temperature of the second processing solution is about 10 to
About 60 ° C, preferably about 15 to 50 ° C is good. 1
If the temperature is lower than 0 ° C., the reaction rate such as adsorption, sorption, and chemical bonding of metal ions to the tannic acid film may be low, and sufficient corrosion resistance may not be obtained. The amount increases and it becomes uneconomical. Further, the processing time by the second processing liquid is about 5 to 180 seconds,
Preferably, the time is about 10 to 150 seconds. If the time is less than 10 seconds, the formation of the rust-preventive film may be insufficient. If the time exceeds 150 seconds, no further effect can be expected in the reduction of the treatment concentration and the rust-preventive performance. The second treatment liquid contains metal ions and / or
Alternatively, in addition to the metal compound, known additives such as an oxidizing agent, a reducing agent, and a chelating agent can be added as a stabilizer in the treatment solution of the metal ion.

The thickness of the second rust preventive film 4 obtained by the treatment with the second treating solution is not particularly limited. However, the upper layer including the surface of the first rust preventive film 3 can be treated under the above treatment conditions. The second rust preventive film 4 having a thickness of about 0.05 to 0.3 μm is obtained in the portion. The total thickness of the first rust preventive film 3 and the second rust preventive film 4 formed on the metal base 2 as described above is not particularly limited. However, when treated under the above-described treatment conditions, a rust-preventive film having excellent rust-preventive properties having a total thickness of about 0.1 to 0.5 μm is obtained.

The first tannic acid shown in FIG.
The rust-preventive film 3 is formed in close contact with the surface of the metal substrate 2, and the second rust-preventive film 4 mainly containing metal ions and / or metal compounds is formed on the upper layer including the surface of the first rust-preventive film 3. Since they are integrally formed, the rust-proofed metal 1 of the present invention has excellent rust-proofing properties and, in addition to the rust-proof coatings 3 and 4, is such that the metal base 2 appears due to scratches. Even if there is, the metal ions and / or the metal compound in the second rust preventive film 4 are supplied to the flaw to cover the flaw and prevent rust, so that the rust resistance is maintained.

FIG. 2 is an explanatory view schematically showing the results of XPS analysis of the cross section of another embodiment of the rust-proofed metal of the present invention in the same manner. In FIG. 2, a rust-preventive metal 1A of the present invention comprises a first rust-preventive film 3 mainly composed of tannic acid formed in close contact with the surface of a metal substrate 2 and an upper layer of the first rust-preventive film 3. A second rust preventive film 4 mainly containing metal ions and / or metal compounds formed on the second rust preventive film 4 and a third rust preventive film mainly composed of tannic acid formed in close contact with the second rust preventive film 4 5 is provided.

The rust-preventive metal 1A of the present invention provided with a plurality of rust-preventive coatings having the structure shown in FIG. 2 has increased rust-preventive properties as compared with the rust-preventive metal 1 of the present invention shown in FIG. In addition to having more excellent rust-prevention properties, even when a plurality of rust-preventing films are used, even if a metal substrate 2 appears due to a flaw, the metal ion is applied to the flaw in the same manner as described above. And / or a metal compound is supplied to cover the wound and prevent rust, so that rust resistance is maintained.

[0040]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example 1) SPCC steel plate (100 × 50
× 1.0 mm) and subjected to galvanization with a plating film thickness of 8 to 12 μm as a test piece, and this test piece was first treated with a first treatment liquid (tannic acid content of 0%) of the composition for forming a rust-preventive film of the present invention. (2 g / l) at 25 ° C. for 60 seconds, followed by washing with water. After the treatment with the first treatment liquid and washing with water, the composition is dipped in the second treatment liquid (V ion content: 10 g / l) of the composition for forming a rust preventive film of the present invention at 25 ° C. for 60 seconds, and then washed with water. Then, it was dried at 60 ° C. for 10 minutes to obtain a rust-proof metal of the present invention. In order to evaluate its corrosion resistance, JIS-
A salt spray test according to 2371 was performed. The evaluation method was evaluated by the time when white rust occurred on the test piece and the time until the area where white rust occurred (the ratio of the total area where white rust occurred to the total area of the test piece) exceeded 5%. Table 1 shows the tannic acid content of the first treatment liquid, the metal ion content of the second treatment liquid, and the salt spray test results.

(Examples 2 to 12) Test pieces were treated in the same manner as in Example 1 except that the first treatment liquid and the second treatment liquid shown in Table 1 were used, and the rust-proofed metal of the present invention was used. I got Table 1 shows the results of the salt spray test performed in the same manner as in Example 1.

[0043]

[Table 1]

Example 13 Using the same test piece as used in Example 1, this test piece was first treated with a first treatment liquid (tannic acid content: 5 g / l) of the composition for forming a rust preventive film of the present invention. 25
After immersion at 30 ° C. for 30 seconds for treatment, the substrate was washed with water. After the treatment with the first treatment liquid and washing with water, the composition for forming a rust-preventive film of the present invention is then treated with the second treatment liquid (Al ion content: 10 g / l) by 25%.
Immersion at 60 ° C. for 60 seconds, washing with water,
After being immersed in a treatment liquid (tannic acid content: 5 g / l) at 25 ° C. for 60 seconds for treatment, it was washed with water and dried at 60 ° C. for 10 minutes to obtain a rust preventive metal of the present invention. Table 2 shows the results of the salt spray test performed in the same manner as in Example 1.

(Examples 14 to 22) A test piece was treated in the same manner as in Example 13 except that the first treatment liquid and the second treatment liquid shown in Table 2 were used, and the rust-proof treated metal of the present invention was used. I got Table 2 shows the results of the salt spray test performed in the same manner as in Example 1.

[0046]

[Table 2]

(Example 23) After the rust-preventive metal of the present invention obtained in Example 18 was cut with a cross-cut in the rust-preventive film using a knife until it reached zinc plating, Example 1 was used.
Table 3 shows the results of the salt spray test performed in the same manner as described above.

(Example 24) The rust-preventive metal of the present invention obtained in Example 19 was cross-cut with a knife using a knife until reaching the galvanization.
Table 3 shows the results of the salt spray test performed in the same manner as described above.

(Embodiment 25) The rust-preventive metal of the present invention obtained in Example 21 was cross-cut with a knife to the rust-preventive film until it reached zinc plating.
Table 3 shows the results of the salt spray test performed in the same manner as described above.

[0050]

[Table 3]

(Comparative Example 1) Using the same test piece used in Example 1, the test piece was immersed in a first treatment solution (tannic acid content 0.2 g / l) at 25 ° C for 30 seconds. Thereafter, it was washed with water and dried at 60 ° C. for 10 minutes to obtain a rust-proof metal for comparison. Table 4 shows the results of the salt spray test performed in the same manner as in Example 1.

(Comparative Examples 2 to 5) Rust-proof metals for comparison were obtained in the same manner as in Comparative Example 1 except that the first treatment liquid shown in Table 4 was used. Table 4 shows the results of the salt spray test performed on the rust-proof treated metals of Comparative Examples 2 to 4 in the same manner as in Example 1. With respect to the rust-proof treated metal of Comparative Example 5, a knife was used to make a cross-cut scratch on the rust-proof coating until zinc plating was reached, and the results of a salt spray test performed in the same manner as in Example 1 are shown in Table 4. Show.

[0053]

[Table 4]

(Comparative Example 6) The same test piece as used in Example 1 was used, and this test piece was treated with the second treatment liquid (V ion content: 5 g).
/ L) at 25 ° C for 60 seconds, followed by rinsing with water and drying at 60 ° C for 10 minutes to obtain a rustproof metal for comparison. Table 5 shows the results of the salt spray test performed in the same manner as in Example 1.

(Comparative Examples 7 to 9) Rust-proof metals for comparison were obtained in the same manner as in Comparative Example 6 except that the second treatment liquid shown in Table 5 was used. Table 5 shows the results of the salt spray test performed in the same manner as in Example 1.

[0056]

[Table 5]

From Table 1, it can be seen that the rust preventive metals of the present invention of Examples 1 to 12 which were treated with the first treatment liquid-the second treatment liquid have excellent rust prevention properties. From Table 2, the rust-preventive metals of the present invention of Examples 13 to 22 were treated with the first treatment liquid-the second treatment liquid and then with the first treatment liquid.
It turns out that it has more excellent rust-proofing property than the rust-proofing metal of the present invention of Examples 1-12 treated with the second treating solution. From Table 3, the rust-proofed metals of the present invention of Examples 18, 19 and 21 have excellent rust-preventive properties even when cross-cut scratches are made in the rust-preventive film until zinc plating is reached, and the rust-proof durability is maintained. It turns out that there is. From Table 4, it can be seen that the rust-proof treated metals of Comparative Examples 1 to 5 which were only treated with the first treatment liquid were inferior in rust-proof properties. From Table 5, Comparative Examples 6 to 9 only treated with the second treatment liquid
It can be seen that the anti-rust treated metal is inferior in anti-rust properties.

(Example 26) (Example of XPS analysis) The same test piece used in Example 1 was processed under the following conditions. Test piece → degreasing (alkaline degreasing agent, 50g / l, 50 ° C,
10 minutes) → water washing → acid washing (35% acid salt, 30 Vol%, room temperature, 5 minutes) → water washing → electrolytic washing (electrolytic cleaning agent, 100 g /
1, room temperature, 3 A / dm ² , 5 minutes) → water washing → zinc plating (standard medium cyanide bath, 2 A / dm ² , 15 minutes, 25 ° C., using organic brightener). Next, in the same manner as in Example 1, a first rust-preventive film (b) mainly composed of tannic acid formed in close contact with the surface of the metal substrate (a), and the first rust-preventive film (b) A second rust preventive film (c) mainly containing a metal ion and / or a metal compound formed on the upper layer portion, and tannic acid formed in close contact with the second rust preventive film (c). And a fourth rust-preventive film (e) mainly containing metal ions and / or metal compounds formed on the upper part of the third rust-preventive film (d). A rust-proof metal (test piece) of the present invention was prepared.

An XPS analysis of the rust preventive film of this test piece was performed under the following conditions. (Surface analysis conditions) Analysis method X-ray photoelectron spectroscopy (XPS) Depth direction analyzer PHI-5400MC (PerkinElmer) XPS measurement Vacuum 1 × 10 ⁷ Pa X-ray source Aluminum (Kα) 1486.7 eV Monochromator Monochromatic 15KV 300W Etching Argon ion beam 4KV, 25mA Argon 5mPa The depth direction analysis is (1) Argon ion etching 6
At 0 seconds, (2) XPS measurement (carbon, oxygen, zinc, vanadium) was repeated to analyze the composition in the depth direction.
Zinc is derived from a metal substrate, carbon and oxygen are derived from a rust-preventive film mainly composed of tannic acid, and vanadium is derived from a rust-preventive film mainly composed of metal ions and the like.

FIG. 3 shows the result of the XPS analysis. In FIG. 3, the vertical axis indicates the atomic concentration (%), and the horizontal axis indicates the sputtering time (minute). One minute of sputtering time is 5nμm (thickness)
Is equivalent to In FIG. 3, C1S is a curve showing carbon, O1S is oxygen, Zn2P3 is zinc, and V2P is a curve showing the atomic concentration (%) of vanadium, respectively. In FIG. 3, the metal substrate (a) has a sputtering time of about 28 minutes or more, the first rust preventive film (b) has a sputter time of about 18 to 28 minutes, and the second rust preventive film (c) has a sputter time of about 28 minutes. It is considered that the region of 12 to 18 minutes, the third rust-preventive film (d) is in the region of about 5 to 12 minutes of the sputtering time, and the fourth rust-preventive film (e) is in the region of 0 to about 5 minutes of the sputter time.

(Example 27) In the same manner as in Example 1, a first rust preventive film (b) mainly composed of tannic acid formed in close contact with the surface of the metal substrate (a), A rust-proofed metal (test piece) of the present invention comprising a second rust-preventive film (c) mainly containing metal ions and / or metal compounds formed on the upper layer of the rust film (b). FIG. 4 shows the results of XPS analysis of the rust preventive film of this test piece in the same manner as in Example 26. In FIG. 4, C1S is a curve showing carbon, O1S is oxygen, Zn2P3 is zinc, and V2P is a curve showing the atomic concentration (%) of vanadium, respectively. FIG.
In the above, the metal substrate (a) has a sputtering time of about 10 minutes or more, and the first rust preventive film (b) has a sputtering time of about 5 to 10 minutes.
Minute area, the second rust-preventive film (c) has a sputtering time of 0 to about 5
In the area of minutes.

[0062]

According to the first aspect of the present invention, there is provided a rust-preventive metal having a plurality of excellent rust-resistant metals formed on the surface of a metal substrate without using harmful chemicals such as hexavalent chromium which affect the environment. Since it is provided with a rust-preventive film, it has excellent rust-preventive properties and maintains its rust-preventive properties even if it is damaged until it reaches the metal substrate.

The rust-proofed metal according to claim 2 of the present invention comprises:
The metal substrate has a metal surface selected from the group consisting of zinc, nickel, aluminum, magnesium, copper, iron and alloys thereof, and has more excellent rust prevention.

The rust-proofing metal according to claim 3 of the present invention comprises:
Metal ions are Al, Cu, Fe, Ni, Mo, V, T
a mixture of one or more metal ions of i, W, Zn, and Zr, wherein the metal compound is a mixture of one or more metal compounds containing these metals, and a more excellent protection. Has rust properties.

The surface of the metal substrate is treated with the first treatment liquid of the composition for forming a rust-preventive film according to claim 4 of the present invention, and adheres to the surface of the metal substrate to form a first tannic acid-based composition. A rust preventive film can be easily formed, and a metal ion and / or a metal compound is formed on the upper layer of the first rust preventive film using the second treatment liquid of the composition for forming a rust preventive film according to claim 4 of the present invention. The second rust-preventive film mainly contained can be easily formed. Furthermore, if necessary, the third rust-preventive film mainly composed of tannic acid can be easily formed in close contact with the surface of the second rust-preventive film using the first treatment liquid. And metal ions and / or
Alternatively, a fourth rust-preventive film mainly containing a metal compound can be easily formed. At least one rust preventive film can be easily formed in close contact with the fourth rust preventive film in the same manner by using the first processing liquid and the second processing liquid.

In the composition for forming a rust-preventive film according to the fifth aspect of the present invention, since the concentration and pH of tannic acid in the first treatment liquid are specified, a rust-preventive film having more excellent adhesion and rust-preventive properties can be obtained. Can be formed.

Since the composition for forming a rust preventive film according to claim 6 of the present invention regulates the pH of the second treatment liquid, a rust preventive film having more excellent adhesion and rust preventive properties can be formed.

According to the method for forming a rust-preventing film according to the present invention, a rust-preventing film having excellent rust-preventing properties and rust-preventing durability can be easily formed.

According to the method for forming a rust-preventive film according to the eighth aspect of the present invention, a rust-preventive film having excellent rust-preventive properties and rust-preventive durability can be easily formed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a result of XPS analysis of a surface of one embodiment of a rust-proofing metal of the present invention.

FIG. 2 is an explanatory view schematically showing the results of XPS analysis of the surface of another embodiment of the rust-proofed metal of the present invention.

FIG. 3 is a graph showing the results of XPS analysis of the surface of the rust-proofed metal of the present invention.

FIG. 4 is a graph showing the result of XPS analysis of the surface of another rust-treated metal of the present invention.

[Explanation of symbols]

 1, 1A Rust-proof metal 2 Metal substrate 3 First rust-proof coating 4 Second rust-proof coating 5 Third rust-proof coating

Continued on the front page F term (reference) 4D075 AE03 BB24Y BB24Z BB61X BB61Y BB61Z BB65Y BB65Z CA33 DA06 DB01 4J038 EA011 JA64 NA03 PA07 PC08 4K062 AA01 BA05 BA06 BA10 BB07 CA03 CA05 FA16 GA08

Claims (8)

[Claims] 1. A first rust preventive film mainly composed of tannic acid formed in close contact with the surface of a metal substrate, and a metal ion and / or metal compound formed on an upper layer of the first rust preventive film. It is provided with a second rust-preventive film mainly containing, and if necessary, a third rust-preventive film mainly composed of tannic acid formed in close contact with the second rust-preventive film. A fourth rust-preventive film mainly containing metal ions and / or metal compounds formed on the upper layer of the third rust-preventive film, or if necessary, a close contact with the fourth rust-preventive film. Then at least one
An anti-rust treated metal comprising two similar anti-rust coatings. 2. The rustproof metal according to claim 1, wherein the metal substrate has a metal surface selected from the group consisting of zinc, nickel, aluminum, magnesium, copper, iron and alloys thereof. 3. The method according to claim 2, wherein the metal ions are Al, Cu, Fe,
A mixture of one or more of metal ions of Ni, Mo, V, Ti, W, Zn, and Zr, wherein the metal compound is a mixture of one or more of metal compounds containing these metals; The rust-proofed metal according to claim 1 or 2, wherein 4. A first treatment liquid containing tannic acid for treating the surface of a metal substrate, and a first treatment liquid containing metal ions and / or a metal compound for successively treating the surface treated with the first treatment liquid. A composition for forming a rust-preventive film, comprising two treatment liquids. 5. The tannic acid concentration of the first treatment liquid is 0.1
The composition for forming a rust-preventive film according to claim 4, wherein the composition is in the range of from 30 to 30 g / l and the pH is in the range of from 3.5 to 8.0. 6. The method according to claim 4, wherein the pH of the second processing solution is in the range of 2.0 to 10.0.
The composition for forming a rust-preventive film according to the above. 7. The surface of a metal substrate is treated with the first treatment solution according to claim 4 to form a first rust preventive film mainly composed of tannic acid in close contact with the surface of the metal substrate. 7. Rinsing, if necessary, followed by treatment with the second treatment solution according to claim 4 or 6, wherein the second rust preventive film mainly contains metal ions and / or metal compounds in the upper layer of the first rust preventive film. A method for forming a rust-preventive film, comprising forming a film, washing with water, and drying. 8. After forming the second rust preventive film, the second rust preventive film is treated with the first treatment liquid according to claim 4 and adheres tightly on the second rust preventive film to form a third rust preventive film mainly composed of tannic acid. After forming the rust-preventive film, it is washed with water and dried, or after the water-washing, if necessary, it is treated with the second treatment liquid according to claim 4 or claim 6 to form an upper layer of the third rust-preventive film. After forming a fourth rust-preventive film mainly containing metal ions and / or metal compounds on the fourth rust-preventive film, it may be washed with water and dried, or, if necessary, may be provided with at least one anti-rust film on the fourth rust-preventive film. The method for forming a rust-preventive film according to claim 7, wherein after forming the rust film, the film is washed with water and dried.