JP2000248377A - Chromium-free surface treated galvanized steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide chromium-free corrosion resistant surface treated steel having an organic polymer coating film layer on the outermost surface to be used for house appliances, building materials, automobiles or the like. SOLUTION: This plated steel is the one in which the lower layer of an electrogalvanizing coating layer of 0.1 to 300 g/m2 coating weight contg., by weight, >=70% zinc, and the balance one or >= two kinds among Fe, Ni, Co, Cr, Mn, Mg, Al, Si and Pb is applied with a metal coating layer of 0.1 to 3000 mg/m2 composed of one or >= two kinds among Ni, Co, Fe, Cr, C and P. In this case, the surface layer of the plating layer has an organic polymer coating layer which does not contain chromium by 0.05 to 50 g/m2 coating weight, and this organic polymers of 100 pts.wt. are incorporated with 0.1 to 50 pts.wt. thiocarbonyl compd. and optionally with phosphate ions, a vanadic acid compd. and silica.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion-resistant surface-treated steel material having an organic resin film on the outermost surface used for home appliances, building materials or automobiles.

[0002]

2. Description of the Related Art In the field of surface treatment of steel sheets, a chromate treatment containing hexavalent chromium is frequently used to improve the corrosion resistance of the steel sheets. However, hexavalent chromium is known to be a harmful element, and there is an increasing demand for surface treatment agents and surface-treated steel sheets that do not contain this hexavalent chromium. In addition, electrolytic chromate mainly composed of trivalent chromium may contain a small amount of hexavalent chromium, and may be difficult to use in the future. The chromate treatment is used as a primary rust preventive treatment for a steel sheet or a plated steel sheet, or as a base treatment for painting or coating. However, development of a chromium-free treatment technique to replace the chromate treatment is desired.

[0003] As a surface treatment technology that does not contain chromium,
There is a phosphate treatment such as a zinc phosphate treatment. However, phosphate treatment is slightly inferior to chromate as a primary rust preventive treatment, and chromium sealing is necessary to ensure corrosion resistance even as a coating base treatment, and is not a sufficient substitute for chromate. It is. In order to solve these problems, JP-A-5-195244 or JP-A-7-145486 proposes a processing method for forming a coating layer containing no chromium. Performance equivalent to that of chromate treatment, that is, corrosion resistance and paint adhesion equivalent to chromate treatment, has not yet been achieved.

[0004]

However, on the surface of the steel base steel, which is the lower layer of the organic polymer film applied to the outermost layer, electro-galvanizing or electro-zinc alloy plating is usually used as a base treatment for improving rust prevention. However, the higher the adhesion between the plating layer surface and the organic polymer film, the better the corrosion resistance. The present invention has a function of controlling the morphology and crystal structure of a plating layer by providing a coating layer made of a dissimilar metal below the electro-zinc alloy coating layer, thereby improving the adhesion of the plating surface. .

[0005]

The gist of the present invention is as follows. (1) Containing at least 70% by weight of zinc, with the balance being Fe, N
i, Co, Cr, Mn, Mg, Al, Si, Pb containing 0.1 to 300 g /
Ni, Co, F under the electrogalvanized coating layer of m ²
e, Cr, C, P, in a plated steel material comprising a metal coating layer having a coating weight of 0.1 to 3000 mg / m ² , comprising an organic polymer coating layer containing no chromium on the surface of the plating layer the has 0.05 to 50 g / m ² in coating weight, the surface treatment of the organic polymer coating layer is characterized by containing 0.1 to 50 parts of thiocarbonyl group-containing compound per 100 parts of organic polymer Steel. (2) The organic polymer coating layer comprises (a) 0.01 to 20 parts by weight of a phosphoric acid component, (b) 1 to 500 parts by weight of silica, and (c) 0.1 to 20 parts by weight of a vanadate compound. The surface-treated steel material according to (1), further comprising at least one of the following.

[0006]

Next, the present invention will be described in detail. The present invention has an organic polymer in the outermost layer, a zinc plating layer comprising at least 70% by weight of zinc in a lower layer, and one of Ni, Co, Fe, Cr, C, and P in a lower layer. Or it is a surface-treated steel material provided with a metal plating layer of two or more types. The outermost organic polymer layer has a function of blocking corrosion reaction factors such as oxygen, water, chloride ions and the like to suppress metal corrosion, and the galvanized layer exhibits corrosion resistance due to a sacrificial corrosion prevention effect of the steel material. Here, increasing the adhesion between the organic polymer film as the outermost layer and the electrogalvanized layer increases the barrier property of a corrosion reaction factor and is very important in securing corrosion resistance. The inventors of the present invention have intensively studied a method for improving the adhesion, and as a result, have refined the crystal of the electrogalvanized layer over the entire plating surface, and made the 002 plane of zinc a certain angle (approximately 5 to 90 degrees) with respect to the substrate. It has been found that it is effective to have the presence. In order to form such an electrogalvanized layer, the amount of adhesion of one or more of Ni, Co, Fe, Cr, C, and P is 0.1 to less than the electrogalvanized layer. 3000mg /
The present inventors have found that a metal coating layer of m ² may be applied, and have made the present invention. Normally, various stains, flaws and defective portions were present on the surface of the steel material, and it was found that such portions showed different shapes and crystal orientations in the plating layer as compared with the healthy portions. Even if there is such a part, if there is a lower plating layer,
It has been found that the upper zinc plating layer is in a uniform and desirable plating layer state. On the other hand, the reason why the adhesion is improved if the 002 plane is formed at a certain angle with respect to the substrate is not clear, but high index planes such as 101 plane, 111 plane, and 102 plane are formed by stacking hexagonal plate-like crystals. On the side surface, fine triangular pyramids or step-like irregularities are formed as can be estimated from the prism surface and the pyramid surface. Further, as the crystal size becomes finer, these irregularities become finer.
Here, it is presumed that these irregularities exert an anchor effect on the coating film to improve the adhesion. Furthermore, since these high index surfaces have more active points for chemical reaction than the 002 surface, it is presumed that the bonding reaction with the coating film is also activated and the chemical bonding force is strengthened. Therefore, even if there is a non-uniform part where the surface of the steel material is unavoidable, in order to obtain good plating layer surface characteristics with good adhesion to the organic coating,
Before applying the galvanized layer, Ni, Co, Fe, Cr, C,
The adhesion amount of one or more of P is 0.1 to 30
It has been found that a metal coating layer of 00 mg / m ² may be applied. This metal coating layer has the effect of shielding non-uniform portions on the surface of the steel material and bringing the morphology and crystal structure of the electrogalvanized layer formed thereon onto the state of excellent adhesion with the organic polymer described above. . The method of forming the undercoat layer is as follows:
Although not specified, examples thereof include an electroplating method, an electroless plating method, a displacement plating method, a vacuum evaporation method, an ion plating method, and a thermal spraying method.

The type of the organic polymer film is not limited as long as it has corrosion resistance, but it is required to exhibit good corrosion resistance even at minute flaws and thin portions of the coating film.
Therefore, it has been found that it is extremely effective to include various rust preventives in the organic polymer. Sulfides, like chromic acid, are easily adsorbed on the metal surface and have excellent oxidizing ability, so that the metal surface can be passivated. Accordingly, the thiocarbonyl group-containing compound, which is one of the oxides, has an effect of preventing white rust of zinc plating.

In addition to the thiocarbonyl group-containing compound, at least one of (a) a phosphoric acid component, (b) silica, and (c) a vanadate compound is present in the organic polymer film. It is effective for improving the corrosion resistance of the treated steel.

For example, when a vanadium compound is added to a rust preventive containing a thiocarbonyl group-containing compound, the following rust preventive action of vanadate ions is added to further enhance the rust preventive effect. . The vanadium compound is ionized and dissolved in the rust inhibitor, and depending on the compound and the amount added, the dissolved amount of ions is saturated and dispersed as a solid in the rust inhibitor to form a rust preventive pigment. And sometimes. In any case, the vanadate ion forms a passivation film on the zinc surface during application. This is the reason why the vanadium compound exhibits a rust preventive action. In addition, when water as a corrosion factor penetrates into the organic polymer film and a corrosion site is formed on the zinc surface, vanadate ions eluted from the vanadate compound by vanadate ions present in the film and permeated water. It is considered that the ions act on the corrosion site to suppress the corrosion reaction.

When the vanadate ion coexists with the thiocarbonyl group compound or the phosphate ion, a synergistic action with them is developed. The reason for this synergism is not clear, but vanadate ions form a passive film at sites where phosphate or thiocarbonyl group-containing compounds cannot be adsorbed, or vice versa. It is considered that a phosphate ion or a thiocarbonyl group is adsorbed on a defective portion of the film to supplement the action of the vanadate ion, thereby obtaining a synergistic effect of the anticorrosion action.

Further, when the thiocarbonyl group-containing compound is added together with phosphate ions, its rust-preventing effect is remarkably improved, and a rust-preventive coating agent superior to the conventional chromium-containing resin-based rust-preventive agent is obtained. It is presumed that this is because the rust-preventing effect is exhibited by the synergistic action of the thiocarbonyl group-containing compound and the phosphate ion. That is,
(1) It is presumed that ions of the thiol group in the thiocarbonyl group-containing compound are adsorbed to sites on the zinc surface when the high-molecular organic coating agent is applied, and exhibit a rust-preventive effect. Naturally, a sulfur atom easily forms a coordination bond with zinc,
Thiocarbonyl group (Formula 1)

[0012]

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The compound having the formula (2)

[0014]

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As described above, those having both nitrogen and oxygen atoms are more preferable. In these compounds, since a nitrogen atom and an oxygen atom can also form a coordinate bond with zinc, a thiocarbonyl compound having these atoms at the same time easily forms a chelate bond on the zinc surface, and the thiocarbonyl compound It is possible to firmly adsorb on the zinc surface. A thiocarbonyl group-containing compound is not adsorbed to sites on the inactive zinc surface (eg, oxide surface), but phosphate ions act on such an inactive surface to form zinc phosphate. To form an active surface. Since the thiocarbonyl group-containing compound is adsorbed on the surface activated in this way, it is presumed that a rust-preventive effect is exerted on the entire zinc surface. Further, (2) both the thiocarbonyl group-containing compound and the phosphate ion act as a crosslinking accelerator for the organic polymer film. It is presumed that the synergistic action of the two can reduce the number of micropores in the organic polymer film and efficiently block harmful ions such as water and chloride ions.

Notably, in addition to the excellent rust-preventing action of the above-mentioned thiocarbonyl group-containing compound, phosphate ions and vanadate ions, the addition of water-dispersible silica to this further promotes the rust-preventing action. It was discovered. Water-dispersible silica adsorbs rust-preventive ions and molecules such as phosphate ions and thiocarbonyl group-containing compounds and vanadate ions onto the silica surface, and appropriately applies rust-preventive ions and the like to the galvanized surface where a corrosion reaction occurs. It is considered that the release of the molecules enhances the rust prevention effect.

As described above, the rust preventive agent found in the present invention is extremely effective in achieving passivation of the metal surface by rust preventive ions and the like. Next, the thiocarbonyl group-containing compound-based rust inhibitor according to the present invention will be described in detail. In the present invention, the thiocarbonyl group-containing compound is
Thiocarbonyl group (1)

[0018]

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The compounds having the formula (I) may further include compounds capable of releasing a thiocarbonyl group-containing compound in an aqueous solution or in the presence of an acid or an alkali. A typical example of the thiocarbonyl group-containing compound is represented by the formula (3)

[0020]

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Thiourea and its derivatives represented by
For example, methylthiourea, dimethylthiourea, ethylthiourea, diethylthiourea, diphenylthiourea, thiopental, thiocarbazide, thiocarbazones, thiocyanuric acids, thiohydantoin, 2-thiouramil, 3
-Thiourazole and the like; Formula (4)

[0022]

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A thioamide compound represented by the formula: thioformaldehyde, thiocarbostyril, thiosaccharin, etc .;

[0024]

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A thioaldehyde compound represented by the following formula: thioformaldehyde, thioacetaldehyde, etc .;

[0026]

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Carbothios represented by the following formulas, for example, thioacetic acid, thiobenzoic acid, dithioacetic acid, etc .;

[0028]

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A thiocarbonate represented by the following formula;
Compounds having the structure, for example, thiocoumazone, thiocumotiazone, thionin blue J, thiopyrone, thiopyrine,
Thiobenzophenone and the like can be exemplified. Among the above, those which do not directly dissolve in water are once dissolved in an alkaline solution and then blended in a rust preventive coating.

Here, if the amount of the thiocarbonyl group-containing compound is less than 0.1 part by weight with respect to 100 parts by weight of the organic polymer, the corrosion resistance becomes insufficient, while if it exceeds 50 parts by weight, the corrosion resistance becomes saturated. Not only is it uneconomical, but when it is added to a resin-containing aqueous solution, the resin gels and cannot be applied depending on the aqueous resin used. Therefore, the upper limit of the treating agent containing no resin is 50 parts by weight.

When the amount of the vanadate compound is less than 0.1 part by weight, the corrosion resistance becomes insufficient. On the other hand, when the amount exceeds 20 parts by weight, not only is the corrosion resistance saturated and uneconomical,
It is not preferable to add the resin to an aqueous solution containing a resin, because the resin gels and the coating becomes impossible. Vanadate compounds are vanadates such as vanadate, ammonium vanadate, sodium vanadate, potassium vanadate, strontium vanadate, sodium hydrogen vanadate, and vanadate such as vanadate, ammonium phosphovanadate and the like. Can be supplied at

Phosphate ions form a phosphate layer on the metal substrate, passivate it, remarkably improve the adhesion between the resin layer and the substrate, and promote the crosslinking reaction of the resin film derived from the aqueous resin. As a result, a dense rust prevention film is formed, so that the rust prevention property is further improved. If the content of phosphate ions is less than 0.01 parts by weight, the rust-preventing effect is not sufficiently exhibited. On the other hand, if the content exceeds 20 parts by weight, corrosion resistance is saturated and uneconomical. When added to an aqueous solution, the resin gels depending on the aqueous resin used, making application impossible. Therefore, the upper limit of the treating agent containing no resin is set to 20 parts by weight.

The corrosion resistance is further improved by adding 1 to 500 parts by weight of water-dispersible silica to the rust preventive coating agent according to the present invention. Moreover, in addition to the corrosion resistance, the drying property, the scratch resistance, and the coating film adhesion can be improved. In the present invention, the water-dispersed silica is a generic term for silica having properties such that it has a fine particle size, maintains a stable state when dispersed in water, and has no semipermanent sedimentation. . The water-dispersible silica is not particularly limited as long as it has a small amount of impurities such as sodium and is weakly alkaline. For example, "Snowtex N" (manufactured by Nissan Chemical Industries), "Adelite AT-20"
N "(manufactured by Asahi Denka Kogyo Co., Ltd.) or commercially available aerosil powdered silica particles can be used.

If the content of the water-dispersible silica is less than 1 part by weight, the effect of improving the corrosion resistance is insufficient, while if it exceeds 500 parts by weight, the corrosion resistance is saturated and uneconomical. The treatment method of the polymer organic coating layer of the present invention is not particularly limited, but a method of forming a film from an aqueous resin, an organic solvent-based resin, a powder resin, or the like is preferable. In particular, in the treatment from an aqueous resin, the above various rust preventive agents are easily mixed, which is good. In the present invention, the term "aqueous resin" includes not only a water-soluble resin but also a water-insoluble resin which is originally insoluble in water and in which an insoluble resin is finely dispersed in water such as an emulsion or a suspension. Examples of resins that can be used as such an aqueous resin include polyolefin resins, polyurethane resins, acrylic resins, polycarbonate resins, epoxy resins, polyester resins, alkyd resins, phenol resins, and other heat-curable resins. And the like, and a crosslinkable resin is more preferable. Particularly preferred resins are polyolefin-based resins, polyurethane-based resins, and mixed resin-based resins of both. The aqueous resin may be used as a mixture of two or more kinds.

The resin-based coating agent according to the present invention may further contain other components.
For example, pigments, surfactants and the like can be mentioned. Further, a silane coupling agent or a hydrolyzed condensate thereof for improving the affinity between the aqueous resin and the silica particles and the pigment, and further improving the adhesion between the aqueous resin and the zinc or iron phosphate layer or the like. You may mix | blend both of them. Here, the “hydrolysis condensate of a silane coupling agent” refers to an oligomer of a silane coupling agent obtained by subjecting a silane coupling agent to a raw material and hydrolyzing and polymerizing the same.

As the above pigment, for example, titanium oxide (T
iO ₂ ), zinc oxide (ZnO), zirconium oxide (Z
rO), calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), alumina (Al ₂ O ₃ ), kaolin clay, carbon black, iron oxide (Fe ₂ O ₃ , Fe ₃
Inorganic pigments such as O ₄ ) and organic pigments can be used.

The silane coupling agent that can be used in the present invention is not particularly limited, but preferred examples include the following: vinylmethoxysilane, vinyltrimethoxysilane, vinylethoxysilane, Vinyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N- (1,3-dimethylbutylidene) ) -3-
(Triethoxysilyl) -1-propanamine, N,
N′-bis [3- (trimethoxysilyl) propyl] ethylenediamine, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ
-Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,
N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane.

Particularly preferred silane coupling agents are vinyltrimethoxysilane, vinylethoxysilane, 3-
Aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N- (1,3-dimethylbutylidene)
-3- (triethoxysilyl) -1-propanamine,
N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine. One of these silane coupling agents may be used alone, or two or more thereof may be used in combination.

In the present invention, the silane compound is added in an amount of 0.1 to 1 liter of a composition containing an aqueous resin and water as main components.
02 to 20 g (silica solid content ratio: about 0.04 to 40
%), Preferably 0.1 to 2.5 g (silica solid content ratio:
(About 0.2-5%). When the addition amount of the silane compound is less than 0.02 g, the effect of the addition is reduced, and the effect of improving the corrosion resistance and the adhesion of the top coat is insufficient.
If it exceeds g, the storage stability decreases, which is not preferable.

A solvent may be used in the rust preventive coating agent containing a resin according to the present invention in order to improve the film forming property of the aqueous resin and form a more uniform and smooth coating film. The solvent is not particularly limited as long as it is generally used in paints, and examples thereof include alcohol-based, ketone-based, ester-based, and ether-based solvents.

As a method for forming the organic polymer film layer, a method is generally used in which a rust-preventive coating agent containing a resin is applied to an object to be coated, and after the application, the object is heated with hot air and dried. The heating temperature is 50 to 250 ° C. 50 ℃
If it is less than 10%, the evaporation rate of water is too slow to obtain a sufficient film-forming property, so that the rust-preventing ability is insufficient. On the other hand, when the temperature exceeds 250 ° C., thermal decomposition of the aqueous resin occurs, so that the salt spray resistance and the water resistance are reduced, and the appearance is yellowed. The drying time when the object to be coated is heated with hot air after application and dried is preferably 1 second to 5 minutes.

The coating thickness of the organic polymer coating layer is desirably a dry thickness of 0.05 μm or more. 0.05μ
If it is less than m, the rust-preventive power is insufficient. On the other hand, if the dry film thickness is too large, problems such as cracks and the like at the time of processing occur, and it is uneconomical.
1 to 20 μm. The coating method is not particularly limited, and the coating can be performed by generally used roll coating, air spray, airless spray, dipping, or the like. After the application, the object to be coated is heated in a hot air oven, a direct fire oven, a 1H oven, or the like, and dried.

The steel material is not particularly limited, but may be a cold-rolled steel plate, a hot-rolled steel plate, a thick plate, a steel bar, a steel tube or the like. By adding a wax to the rust preventive coating agent of the system containing the resin of the present invention, it can be used as a lubricating rust preventive for lubricated steel sheets. In the following examples, the corrosion resistance was evaluated by the following method. [Evaluation method] (A) Rust prevention a) Preparation of specimens A commercially available cold-rolled steel sheet was electroplated with a predetermined amount of the first layer, and after washing with water, the second layer of galvanized layer was further subjected to electricity. It was applied by a plating method. After washing and drying, a water-soluble rust inhibitor containing a high-molecular organic substance was applied by a bar coat # 3 so as to have a predetermined adhesion amount, and then dried to a PMT of 150 ° C.

B) Salt Spray Test A test method in accordance with JIS Z2371 (5% saline was sprayed on the surface of the object to be coated at 35 ° C., and the degree of white rust after 240 hours was evaluated on a scale of 1 to 10. Is a flat part and Eriksen 7
This was performed for both the mm extruded portions. The evaluation criteria were as follows.

10 points: no abnormality 9 points: between 10 points and 8 points 8 points: slight white rust generation 7 points to 6 points: between 8 points and 5 points 5 points: white rust generation in half of the area 4 2 points: between 5 points and 1 point 1 point: white rust occurred on the entire surface (B) Top coat adhesion a) Preparation of test specimen After drying the above surface treatment material, Super Rack 100 (manufactured by Nippon Paint Co .; acrylic) Melamine paint) dried film thickness 2
PMT1 after coating with a bar coat to a thickness of 0 μm
The coating was dried at 50 ° C. for 20 minutes to produce a topcoat adhesion test plate.

B) Primary Adhesion Test Crosscut: The tape peelability of a portion having a crosscut of 1 mm was evaluated, and the tape was evaluated on a scale of 10 out of the following criteria. Erichsen 7 mm: A tape was applied to a portion extruded with Erichsen to 7 mm, and the tape peelability was similarly evaluated.

Cross-cut + Erichsen 7 mm: A tape with a cut of 1 mm in cross-section was extruded to 7 mm with Erichsen, and a tape was applied thereto. The evaluation criteria were as follows. 10 points: No abnormality 9 points: The percentage of peeling out of the grids measured was 10% or less 8 points: ２０ 20% or less 7 points: ３０ 30% or less 6 points: ４０ 40% or less 5 points: ５０ 50% or less 4 Points: 〃60% or less 3 points: ７０70% or less 2 points: 〃80% or less 1 point: ９０90% or less 0 points: 大 Greater than 90% c) Secondary adhesion test Immerse the test plate in boiling water for 30 minutes Thereafter, the same test and evaluation as the temporary test were performed.

[0048]

EXAMPLES Examples 1 to 6 show examples and comparative examples. Example 1
29 are the lower plating metal type, the amount of adhesion, the upper plating type,
Although the amount of adhesion, the components of the polymer organic coating layer, and the amount of adhesion were variously changed, all exhibited good SST resistance and topcoat adhesion within the scope of the present patent. On the other hand, in the comparative example, the SST resistance and the overcoat adhesion were not sufficient.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

[Table 4]

[0053]

[Table 5]

[0054]

[Table 6]

[0055]

As described above, according to the present invention, Fe, N
By applying a Zn-based plating to a base plating treatment of i, Co, Cr, etc. and further applying an organic polymer coating layer, a surface-treated steel material having good adhesion between the plating and the polymer layer and excellent corrosion resistance is provided. It becomes possible.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Atsushi Morishita 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Corporation Kimitsu Works (72) Inventor Toshiaki Shimakura 4-1-1-15 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint Co., Ltd. (72) Inventor Katsuyoshi Yamazoe 4-1-1-15 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint Co., Ltd. F-term (reference) 4K044 AA03 AB02 BA10 BA12 BA14 BA17 BA21 BB04 BC02 CA18 CA53

Claims (2)

[Claims] 1. A composition containing at least 70% by weight of zinc and the balance of F
e, Ni, Co, Cr, Mn, Mg, Al, Si, Pb
Is 0.1 to 30 containing one or more kinds of
0 g / m ² of electrogalvanized coating layer
Organic polymer that does not contain chromium in the surface layer of the plating layer in a plated steel material comprising a metal coating layer of one or more of o, Fe, Cr, C, and P having an adhesion amount of 0.1 to 3000 mg / m ^2. 0.05 to 50 g / m in coating weight of coating layer
^2. A surface-treated steel material, wherein the organic polymer coating layer contains 0.1 to 50 parts of a thiocarbonyl group-containing compound based on 100 parts of the organic polymer. 2. The organic polymer coating layer comprises: (a) 0.01 to 20 parts by weight of a phosphoric acid component, (b) 1 to 500 parts by weight of silica, and (c) 0.1 to 20 parts by weight of a vanadate compound. The surface-treated steel material according to claim 1, further comprising at least one of: