JP2000282252A - Non-chromium type surface treated metal material - Google Patents

Abstract

(57) [Problem] To provide a non-chromium type surface-treated metal material excellent in corrosion resistance without containing hexavalent chromium. SOLUTION: This metal material has a lower rust-preventive film containing an inhibitor component formed on the surface of the metal material and an upper rust-preventive film containing the inhibitor component further formed thereon. The film has a thickness of 0.1 to 5 μm, and as a solid content, (1) 100 parts by weight of an organic resin and a thiocarbonyl group-containing compound 0.2 to 5 as an inhibitor component.
100 parts by weight, or (2) 100 parts by weight of an organic resin and 0.2 to 200 parts by weight of a vanadate compound as an inhibitor component, and the upper anticorrosive film has a thickness of 0.1 to 5 μm and a solid content of: (3) 100 parts by weight of an organic resin and 0.1 to 50 parts by weight of a thiocarbonyl group-containing compound of an inhibitor component, or (4) 100 parts by weight of an organic resin and 0.1 to 20 parts by weight of a vanadate compound of an inhibitor component. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to home appliances, construction materials,
The present invention relates to a non-chromium type surface-treated metal material used for automobiles and the like which does not contain hexavalent chromium and has excellent corrosion resistance.

[0002]

2. Description of the Related Art For example, galvanized steel sheets or galvanized steel sheets in a salty atmosphere such as seawater or in a high-temperature and high-humidity atmosphere have white rust on the surface and significantly impair the appearance of the steel sheet. The power is reduced.

In order to prevent white rust, a chromate-based rust preventive agent has conventionally been used.
No. 370 describes a resin-based treating agent comprising a water-dispersible chromium compound and water-dispersible silica in an olefin-α, β-ethylenically unsaturated carboxylic acid copolymer resin dispersion.

[0004] Such a film made of a chromate-based treating agent is recognized as having the best corrosion resistance among known treating agents. Nevertheless, the film formed by the chromate treatment contains hexavalent chromium, which is known to be a harmful element. Therefore, there is an increasing demand for a surface-treated metal plate containing no hexavalent chromium.

[0005] Non-chromium rust preventive agents containing no harmful chromium are disclosed in JP-A-8-239776 and JP-A-8-6.
No. 7834, which uses sulfide and sulfur. However, not only sulfur but also some sulfides give off a peculiar odor, and handling of these treating agents was not always easy.

[0006] A treating agent using a triazine thiol compound containing a sulfur atom but having no odor or toxicity has also been proposed. For example, Japanese Patent Application Laid-Open No. 31737/1983 discloses an aqueous solution containing a dithiol-S-triazine derivative. An anticorrosive paint is disclosed. However, this water-soluble anticorrosive paint
It is intended to prevent corrosion of mild steel, copper, brass, etc., and is particularly prepared so that the base material is more easily adhered to copper or brass. Therefore, it is not sufficient as a rust inhibitor for metal surfaces such as zinc.

[0007] JP-A-61-223062 describes a reactive emulsion of a metal obtained by mixing a thiocarbonyl group-containing compound with an organic compound which is hardly soluble or insoluble in water. However, this emulsion also
It reacts with copper, nickel, tin, cobalt, aluminum and the like and their alloys, and is still insufficient as a rust inhibitor for metal surfaces such as zinc.

The applicants of the present application have disclosed in Japanese Patent Application No. 9-2557 a triazinethiol-containing rust-preventive coating agent which is also effective for rust-prevention of galvanized steel sheets. However, triazine thiol is an expensive compound, so it would be beneficial to have a less expensive rust inhibitor.

As a surface treatment method for zinc or zinc alloy which does not contain chromium and does not use triazine thiol,
JP-A-54-71734 and JP-A-3-2265.
No. 84 is disclosed. JP-A-54-
No. 71734 discloses a treatment method in which 2 to 6 bonded phosphate esters of myo-inositol or salts thereof are mixed with 0.5% of myo-inositol.
And at least one of titanium fluoride and zirconium fluoride is 0.5 to 30 g in terms of metal.
/ L and an aqueous solution containing 1 to 50 g / l of thiourea or a derivative thereof for surface-treating zinc or a zinc alloy. This method requires titanium fluoride or zirconium fluoride to form a passivation film as a protective layer on the zinc surface. JP-A-3-226584 discloses that one or both of Ni ²⁺ and Co ²⁺ is 0.02 g / l.
A surface treatment agent that is an aqueous solution having a pH of 5 to 10 containing the above and at least one of the compounds having ammonia and a primary amine group is used. This treatment agent requires one or both of Ni ²⁺ and Co ^{2+ to} impart coating adhesion and corrosion resistance after coating by depositing cobalt or nickel. The treating agents containing these metal ions have disadvantages such as an increase in load during wastewater treatment.

[0010]

As described above, conventional rust inhibitors containing no chromium are inferior to chromium-containing rust inhibitors in terms of corrosion resistance, and have other disadvantages as described above. Was. So, instead of chromium-containing rust inhibitor,
In addition, there has been a strong demand for the development of a new rust inhibitor that does not have the above-mentioned disadvantages.

As a new technique for satisfying these demands, the present applicant has proposed a rust-proof coating containing an aqueous resin, a thiocarbonyl group-containing compound and a phosphate ion, and optionally containing finely divided silica (Japanese Patent Application No. Hei. 10-36265
No.) was developed. In addition, a rust preventive coating (Japanese Patent Application No. 10-36264) containing an aqueous resin, a thiocarbonyl group-containing compound and fine silica particles and containing no phosphate ions was developed. Furthermore, a rust-preventive coating (Japanese Patent Application No. 10-36267) containing an aqueous resin and a vanadate compound, and optionally further containing at least one of a thiocarbonyl group-containing compound, a phosphate ion and finely divided silica. developed.

[0012] Such a new antirust coating agent is
Since it does not contain chromium and has excellent corrosion resistance, it can be used in place of zinc-coated steel such as zinc-plated or zinc-alloy-plated steel, as well as aluminum-coated steel (Al-coated steel) and uncoated steel instead of conventional chromate-based treatment agents. It is expected to be used as an anticorrosive agent for, etc. Further improvement of the corrosion resistance inherent in these new rust preventive coating agents is very useful in further enhancing the practicality of metal materials surface-treated with these rust preventive coating agents and promoting their use. is there.

Accordingly, an object of the present invention is to provide a non-chromium type surface-treated metal material having improved corrosion resistance.

[0014]

According to the present invention, there is provided a non-chromium type surface-treated metal material comprising a lower rust-preventive film containing an inhibitor component formed on the surface of the metal material, and further formed thereon.
The lower rust-preventive film having an inhibitor component and an upper rust-preventive film having a thickness of 0.1 to 5 μm and having a solid content of (1) 100 parts by weight of the organic resin and a thiocarbonyl group of the inhibitor component. 0.2 to 500 parts by weight of a compound contained, or (2) 100 to 100 parts by weight of an organic resin and 0.2 to 200 parts by weight of a vanadate compound as an inhibitor component, and the upper anticorrosive film has a thickness of 0.1 to 5 μm. In terms of solid content, (3) 100 parts by weight of an organic resin and 0.1 to 50 parts by weight of a thiocarbonyl group-containing compound of an inhibitor component, or (4) 100 parts by weight of an organic resin and a vanadate compound 0 of an inhibitor component 0.1-20 parts by weight.

[0015] The lower rust-preventive coating containing the solid content of the above (1) further comprises 0.1 to 200 parts by weight (as PO ₄ ) of an inhibitor component of a phosphoric acid compound and 1 to 500 parts by weight of fine silica. The lower rust-preventive film containing a solid content of the above (2) may further contain 0.2 to 500 parts by weight of an inhibitor component of a thiocarbonyl group-containing compound, 0.1 or more. ~ 200 parts by weight (PO
₄ ) an inhibitor component of a phosphoric acid compound and 1 to
Optionally, at least one or more of 500 parts by weight of finely divided silica can be contained.

Further, the upper rust-preventive film containing the solid content of the above (3) further comprises 0.01 to 20 parts by weight (as PO ₄ ) of an inhibitor component of a phosphoric acid compound and 1 to 500 parts by weight of fine silica particles. At least one of the above, and the upper rust-preventive film containing the solid content of the above (4) may further contain 0.1 to 50 parts by weight of an inhibitor component of a thiocarbonyl group-containing compound, 0.1 to 20 parts by weight (as PO ₄ ) of an inhibitor component of a phosphoric acid compound and at least one of 1 to 500 parts by weight of fine silica.
Optionally, more than one species may be included.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, metal materials to be surface-treated with a rust preventive film are zinc-coated steel, aluminum-coated steel (Al-coated steel) and uncoated steel. The zinc-coated steel is, specifically, galvanized, zinc and Fe, Ni, Co, C
r, Mg, Al, Si, Mn, etc. refers to a steel material that has been subjected to alloy plating comprising one or more of the same, and the plating method is not particularly limited, and may be an electroplating method, a hot-dip plating method, or a vacuum method. Any method such as a plating method may be used. 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 pipe, a wire, or the like.

These metal materials may be subjected to an optional surface treatment such as degreasing before forming a rust preventive film.

The non-chromium type surface treated metal material of the present invention has a rust-preventive coating layer having a laminated structure composed of a lower rust-preventive film and an upper rust-preventive film. The lower rust-preventive film has a solid content of (1) 100 parts by weight of an organic resin and 0.1% of a thiocarbonyl group-containing compound.
A film having a thickness of 0.1 to 5 μm, comprising 2 to 500 parts by weight or (2) 100 parts by weight of an organic resin and 0.2 to 200 parts by weight of a vanadate compound. The upper rust-preventive film has a solid content of (3) 100 parts by weight of an organic resin and 0.1 to 50 parts by weight of a thiocarbonyl group-containing compound, or (4) 100 parts by weight of an organic resin and 0.1 to 20 parts of a vanadate compound. It is a coating having a thickness of 0.1 to 5 μm, including parts by weight.

In the present invention, the upper coating containing the solid content of (3) may be present on the lower coating containing the solid content of (1), or the upper coating containing the solid content of (4) May be present. Similarly, the upper layer coating containing the solid content of (3) may be present on the lower layer coating containing the solid content of (2), or the upper coating containing the solid content of (4) may be present. Good.

Further, when the essential inhibitor component is a thiocarbonyl group-containing compound in the lower and upper coatings of the present invention, a phosphoric acid compound as an additional inhibitor component and a fine silica having an anticorrosion promoting action are added. At least one of them may coexist. When the essential inhibitor component of the lower layer and the upper layer film is a vanadate compound, at least one or more of a thiocarbonyl group-containing compound and a phosphate compound as additional inhibitor components and fine silica having a corrosion resistance promoting action. May coexist. In each case, the content of the vanadate compound as an additional inhibitor component in the underlayer coating was 0.1%.
2 to 200 parts by weight, the content of the phosphoric acid compound is 0.1 to 20
0 parts by weight (as PO ₄ ) is preferred, the fine silica content is preferably 1 to 500 parts by weight, while the vanadate compound content of the additional inhibitor component in the upper coating is 0.1 to 20 parts by weight, Phosphate compound content is 0.0
1-20 parts by weight (as PO ₄₎ is preferable, fine silica content is preferably 1 to 500 parts by weight.

As described above, important points in the present invention are:
This is due to the presence of a higher concentration of inhibitor components in the lower coating than in the upper coating.

These rust preventive films are based on organic resins. This organic resin is obtained by applying a composition containing an aqueous resin and other components of a rust-preventive film in water and then drying it. The term "aqueous resin" used herein includes, in addition to a water-soluble resin, a resin (a water-dispersible resin) that is insoluble in nature but can be in a finely dispersed state in water, such as an emulsion or a suspension. .

The resin usable as the aqueous resin in the present invention includes, for example, polyolefin resin, acrylic olefin resin, polyurethane resin, acrylic resin, polycarbonate resin, epoxy resin, polyester resin, alkyd resin, Phenolic resin,
Other heat-curable resins can be exemplified, and a crosslinkable resin is more preferable. Particularly preferred resins are
An acrylic olefin resin, a polyurethane resin, and a mixed resin of both. The aqueous resin may be used as a mixture of two or more or copolymerization.

The rust-preventive film of the present invention contains a thiocarbonyl group-containing compound or a vanadate compound as an essential component, so that its rust-preventing effect is significantly improved.

The thiocarbonyl group-containing compound is a sulfide, is easily adsorbed on the metal surface, and has excellent oxidizing power. Therefore, the thiocarbonyl group-containing compound has a rust prevention effect by passivating the metal surface. In particular, it is considered that thiol group ions in the thiocarbonyl group-containing compound are adsorbed to active sites on the metal surface and exhibit a rust-preventive effect.

The thiocarbonyl group-containing compound acts as a crosslinking accelerator for the resin film, reduces the micropores in the resin film, and has the effect of efficiently blocking harmful ions such as water and chloride ions. Is also considered to contribute to the rust prevention effect.

In the present invention, the thiocarbonyl group-containing compound is a thiocarbonyl group represented by the following formula:

[0029]

Embedded image

And a compound capable of releasing a thiocarbonyl group-containing compound in an aqueous solution or in the presence of an acid or an alkali. Typically,

Embedded image

Thiourea represented by the following formulas and derivatives thereof, for example, methylthiourea, dimethylthiourea, ethylthiourea, diethylthiourea, diphenylthiourea, thiopental, thiocarbazide, thiocarbazones, thiocyanuric acids, thiohydantoin, 2-thiouramyl,
Such as thiourazole,

[0032]

Embedded image

A thioamide compound represented by the formula:
Is, for example _{-H, -CH 3, -CH 2 CH} 3, -C 6 H
₅ etc.), for example, thioformamide, thioacetamide, thiopropionamide, thiobenzamide,
Thiocarbostyril, thiosaccharin, etc.

[0034]

Embedded image

(Wherein R represents, for example, —H, —CH _3, etc.), for example, thioformaldehyde, thioacetaldehyde, etc.

[0036]

Embedded image

Carbothioic acids represented by the formula (R in the formula:
For example -CH _3, represents a -C ₆ H _5, etc.), as an example, thioacetic acid, thiobenzoic acid, and the like dithio acetate, the formula

[0038]

Embedded image

And other compounds having the structure of formula (1), for example, thiocoumazone,
Thiocmotiazone, thionin blue J, thiopyrone, thiopyrine, thiobenzophenone and the like are exemplified.

When the thiocarbonyl group-containing compound is contained in the undercoat, the amount thereof is determined as a solid content of the organic resin 10.
The amount is preferably 0.2 to 500 parts by weight with respect to 0 parts by weight.
1 to 50 parts by weight is preferred. If the content of the thiocarbonyl group-containing compound in the lower layer and the upper layer film is less than the lower limit, respectively, the effect as an inhibitor becomes inconspicuous. The effect cannot be expected.

The thiocarbonyl group-containing compound can be solely contained in the rust preventive film as an essential inhibitor component, or added as an additional optional component in the rust preventive film containing a vanadate compound as an essential inhibitor component. You may. When the thiocarbonyl group-containing compound and the vanadate compound coexist, they are considered to exert a rust-preventive effect by their cooperative action.

When the rust-preventive film contains a vanadate compound, it exhibits the same rust-preventive action as a chromic compound.
That is, the vanadate compound forms a passivation film on the surface of the metal material when the composition for forming a rust prevention film is applied, and exhibits a rust prevention effect. Further, the vanadate compound has an effect that even when a corrosion site occurs on a metal surface (particularly a galvanized surface), vanadate ions present in the film act on the corrosion site to suppress a corrosion reaction. Conceivable.

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

When the vanadate compound is contained in the lower layer coating, the amount thereof is preferably 0.2 to 200 parts by weight as solids per 100 parts by weight of the organic resin. 0.1 to 20 parts by weight
Parts by weight are good. If the contents of the vanadate compound in the lower layer and the upper layer are each less than the above lower limit, the rust preventive effect is not sufficient, and if it is more than the above upper limit, the rust preventive effect is saturated and uneconomical.

The rust preventive film of the present invention can contain any additional inhibitor component in addition to the thiocarbonyl group-containing compound or the vanadate compound which is an essential inhibitor component. When the thiocarbonyl group-containing compound is an essential component, the antirust coating can contain a phosphate compound as an optional inhibitor component, while, when the vanadate compound is an essential component, the thiocarbonyl group-containing compound and It can contain at least one or more of phosphoric acid compounds.

As described above, the thiocarbonyl group-containing compound or the vanadate compound, which is an essential inhibitor component in the rust-preventive film of the present invention, is adsorbed to active sites on the metal surface and exhibits a rust-preventive effect. However, the optional phosphate compound acts on an inactive site on the metal surface to form an active surface, on which the thiocarbonyl group-containing compound or the vanadate compound is adsorbed, thereby preventing the phosphate compound. It is considered that it exhibits a rust effect. Also,
Phosphoric acid compounds also act as a crosslinking accelerator for the resin film, reducing the micropores in the resin film and effectively blocking harmful ions such as water and chloride ions, which also contributes to the rust prevention effect. Can be

The phosphate compound may be any compound containing a phosphate ion. For example, ammonium phosphate, sodium phosphate, potassium phosphate and the like can be used.

When a phosphoric acid compound is contained in the underlayer coating,
The amount thereof is preferably 0.1 to 200 parts by weight (as PO ₄ ) based on 100 parts by weight of the organic resin as a solid content, and 0.01 to 200 parts by weight based on 100 parts by weight of the organic resin when contained in the upper layer coating. 20 parts by weight (as PO ₄₎ is good. If the content of the phosphoric acid compound in the lower layer and the upper layer is less than the above lower limit, a sufficient rust-preventing effect cannot be obtained, while if the content exceeds the above upper limit, the rust-preventing effect is reduced, or the state of the coating solution is reduced. In some cases, the resin gels or causes problems.

The lower and upper rust preventive films of the present invention may contain finely divided silica together with or without any of the above-mentioned inhibitor components. When the rust preventive film contains fine silica, its rust preventive action (corrosion resistance) is remarkably promoted. Moreover, in addition to the corrosion resistance, the drying property at the time of film formation, the abrasion resistance and adhesion of the formed film can be improved.

In the present invention, the term "fine silica" refers to silica having such a property that when it is dispersed in water, it can stably maintain a water-dispersed state and has no semi-permanent sedimentation. It is a generic term. The finely divided silica is not particularly limited as long as it has a small amount of impurities such as sodium and is weakly alkaline. For example, commercially available silica gel such as "Snowtex N" (manufactured by Nissan Chemical Industries, Ltd.) and "Adelite AT-20N" (manufactured by Asahi Denka Kogyo KK), or commercially available aerosil powdered silica can be used.

When fine silica is contained, the content of the fine silica is preferably 1 to 500 parts by weight, based on 100 parts by weight of the organic resin, as a solid content in both the lower layer coating and the upper layer coating. If the amount is less than 1 part by weight, the effect of addition is small, and if it exceeds 500 parts by weight, the effect of improving the corrosion resistance is saturated and uneconomical, and the film becomes too hard, resulting in film cracking and peeling, resulting in deterioration of the corrosion resistance. There is also.

When the finely divided silica is used in combination with the vanadate compound, the vanadate compound is adsorbed on the surface of the finely divided silica, and the rust-preventing effect is synergistically exhibited. In this sense, when the fine silica particles are of the ammonium adsorption type or the aluminum oxide coating type, the silica particles are easily adsorbed and the rust prevention effect is improved, which is preferable.

As described above, an important point in the present invention is that an inhibitor component has a higher concentration in the lower film than in the upper film. As described above, the presence of the coating having a higher inhibitor concentration in the portion close to the metal material surface improves the corrosion resistance of the processed portion of the metal material (the coating is easily cracked), the scratched portion, and the end face particularly. I do. In such a portion, the metal material underlying the rust-preventive film is easily exposed to the external atmosphere, and corrosion is likely to occur. However, according to the present invention, since the inhibitor component is concentrated near the metal surface, the inhibitory effect is reduced. It is considered that the rust effect is promoted. This promotion of the rust-preventive action is particularly noticeable in a corrosive environment where water is present. This is presumably because the concentrated inhibitor component in a region near the metal material elutes into water and exerts a rust-preventive effect on the exposed metal surface.

The rust preventive film in the present invention may contain components other than the above components in both the lower layer film and the upper layer film. For example, pigments, surfactants and the like can be mentioned. Further, in order to improve the affinity between the organic resin and the silica particles and the pigment, and to further improve the adhesion between the organic resin and the base metal, a silane coupling agent or a hydrolyzed condensate thereof or both of them are blended. You may. 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 pigment, for example, titanium oxide (Ti
O ₂ ), zinc oxide (ZnO), zirconium oxide (Zr
O ₂ ), calcium carbide (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 various coloring pigments such as 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 used in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the organic resin.
It is preferably 0 parts by weight. When the addition amount of the silane compound is less than 0.01 part by weight, 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 the amount exceeds the weight part, the resin may gel in the state of the coating solution, which may cause a problem.

In order to form a rust-preventive film layer having a laminated structure according to the present invention, a coating composition containing predetermined components (aqueous resin as an organic resin, an inhibitor component, and other optional components) in water is used. Prepare, apply to the underlying metal material,
The coating film is heated and dried to first form an underlayer coating. Next, another coating agent composition containing a predetermined component in water is similarly prepared, applied on the lower layer coating, and the coating is heated and dried to form an upper layer coating. The coating composition may be prepared at any concentration. In general, a coating composition containing 1 to 80 parts by weight of solids (a component other than water) and 99 to 20 parts by weight of water is preferable from the viewpoint of application and subsequent heating and drying. The method of applying the coating composition is not particularly limited, and generally known application methods such as roll coating, air spray, airless spray, and immersion can be employed.

By heating each coating film, the resin is cured in the case of a curable resin, and the resin is crosslinked in the case of a crosslinkable resin. Heating and drying (baking) of the coating film may be performed by a known method using a hot blast stove, an induction heating furnace, a near-infrared furnace, a direct-fired furnace, or a combination thereof. Alternatively, air drying may be performed without using the forced drying, or the metal material may be preheated, and the coating agent composition may be applied thereto and air dried. In addition, depending on the type of the aqueous resin used, the resin can be cured by energy rays such as ultraviolet rays and electron beams. As the heating temperature,
50-250 degreeC is good. If the temperature is less than 50 ° C., 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 organic resin occurs, so that there is a problem that the corrosion resistance and the water resistance are reduced and the appearance is yellowed. 70-200 degreeC is more preferable. Cooling after heating and drying may be performed by a known method such as water cooling, air cooling, natural cooling, or a combination thereof.

The thickness (dryness) of the rust preventive film to be formed is preferably 0.1 μm or more for both the lower layer and the upper layer. 0.1
Films smaller than μm are difficult to form. Further, when the total thickness of the lower layer and the upper layer is less than 0.2 μm,
Sufficient rust prevention (corrosion resistance) cannot be obtained. On the other hand, when the film thickness is large, further improvement in rust prevention (corrosion resistance) is not recognized so much, which is uneconomical. Therefore, it is appropriate that the upper limit of the film thickness of both the lower layer and the upper layer is 5 μm.
Preferably, the total thickness of the lower layer and the upper layer is 0.4 to 5
It is about μm.

[0062]

Next, the present invention will be further described with reference to examples.
Of course, the invention is not limited to these examples.

The electrogalvanized steel sheet having a coating weight of 20 g / m ² per side and a thickness of 0.8 mm was used as a base.
An aqueous coating solution containing the surface treating agent having the composition of the lower rust-preventive film shown in No. 4 as a total solid content of 20% by weight was applied by a roll coater and dried in a hot-air drying oven to form a lower rust-preventive film. An aqueous coating solution containing a surface treatment agent having an upper rust-preventive coating composition shown in Tables 1 to 4 and having a total solid content of 20% by weight was applied thereon using a roll coater, and dried in a hot-air drying oven to form an upper rust-preventive coating. Formed. Thickness of each film (μ
m) and drying conditions (baking plate temperature) are shown in Tables 1-4. The stability of the treatment liquid was good, and after leaving it at room temperature for three months, the quality was almost the same as the initial one. Also, a hot-dip galvanized steel sheet having a coating weight of 60 g / m ² per side and a thickness of 0.8 mm, a galvannealed steel sheet having a coating weight of 40 g / m ² per side and a thickness of 0.8 mm, A surface-treated steel sheet using a zinc-nickel alloy-plated steel sheet (nickel content: 11% by weight) having a thickness of 0.8 mm and an amount of 20 g / m ² per side as a base was also evaluated in the same manner. Table 1
4 shows the plating type. EG is an electrogalvanized steel sheet, GI is a hot-dip galvanized steel sheet, GA is an alloyed hot-dip galvanized steel sheet, and ZN is a zinc-nickel alloy-plated steel sheet. The contents of the surface treatment agents shown in Tables 1 to 4 are as follows.

1. Aqueous resin type Olefin: "HITEC S-7024" (Toho Kagaku) Urethane: "Bon Titer HUX-320" (Asahi Denka) Acrylic: "AP-1058 (12)" (Toa Gosei) Epoxy type: "Polysol 8500" (manufactured by Showa Polymer Co., Ltd.) Polyester type: "Pesresin A-124G" (manufactured by Takamatsu Yushi Co., Ltd.) Urethane olefin type: The above olefin type and urethane type were mixed at a solid content of 1: 1. thing

2. Colloidal silica ST-N: "Snowtex N" (manufactured by Nissan Chemical Industries) ST-S: "Snowtex S" (manufactured by Nissan Chemical Industries) ST-C: "Snowtex C" (manufactured by Nissan Chemical Industries) AT-20N: "Adelite AT-20N" (made by Asahi Denka Kogyo)

3. Phosphate ion Ammonium phosphate: Diammonium hydrogen phosphate first grade (manufactured by Kanto Chemical Co., Ltd.) was dissolved in the treating agent such that the phosphate ion concentration became parts by weight in Tables 1-4.

4. Thiocarbonyl group-containing compound Thiourea: Thiourea Class 1 (Kanto Chemical Co., Ltd.)

5. Vanadate Compound Ammonium Vanadate: Ammonium Vanadate Class 1 (Kanto Chemical Co., Ltd.)

6. Silane compound A: γ-glycidoxypropyltriethoxysilane “K
BE-403 "(manufactured by Shin-Etsu Chemical Co., Ltd.) B: γ-glycidoxypropyltrimethoxysilane" K
BM-403 "(Shin-Etsu Chemical Co., Ltd.) C: Vinyltrimethoxysilane" KBM-1003 "
(Manufactured by Shin-Etsu Chemical Co., Ltd.) D: N-β (aminoethyl) γ-aminopropyltriethoxysilane “KBE-603” (manufactured by Shin-Etsu Chemical Co., Ltd.) E: γ-mercaptopropyltrimethoxysilane “KB”
M-803 "(Shin-Etsu Chemical Co., Ltd.)

The prepared surface-treated steel sheet was evaluated as follows, and the results shown in Tables 5 to 8 were obtained. 1. Finished Appearance The appearance of the treated film was judged visually and scored. The rating was 5: uniform, 4: very slight unevenness, 3: partial unevenness, 2: overall unevenness, and 1: severe unevenness on the entire surface.

2. Adhesiveness of rust-preventive film Flat plate adhesiveness was determined by the cross-cut tape method (gap 1 mm) described in 8.5.2 of JIS K 5400. The evaluation was made according to the criteria shown below. The corrosion resistance of the processed portion was determined by extruding with an Erichsen tester specified in 8.2 of JIS K 5400, peeling the extruded portion with a tape, and visually determining the peeling of the film. The adhesion between the flat plate and the processed portion was rated according to the following criteria.

10 points: no peeling 9 points: peeling area of 3% or less 8 points: peeling area of more than 3% and 5% or less 7 points: peeling area of more than 5% and 8% or less 6 points: more than 8% and 10% or less 5 points: Peeling area of more than 10% and 15% or less 4 points: Peeling area of more than 15% and 30% or less 3 points: Peeling area of more than 30% and 50% or less 2 points: Peeling more than 50% and 75% or less Area 1 point: Exfoliation area of more than 75%

When it is difficult to judge visually, the film is dyed with a 0.1% acetone solution of methyl violet, and the film exists in the stained portion, and the film does not exist in the unstained portion. The adhesiveness of the film was determined as The same applies to the appearance evaluation of the treated film.

3. Olga Select 100 which is a melamine alkyd paint
(Nippon Paint Co., Ltd.), dry film 25μ
m, and dried and baked in a hot air oven at 150 ° C. for 20 minutes, and then the adhesion was evaluated. In the evaluation, the flat plate adhesion was determined by the cross-cut tape method (1 mm gap) described in 8.5.2 of JISK 5400. The corrosion resistance of the processed portion was determined by extruding 7 mm with an Erichsen tester specified in 8.2 of JIS K 5400, peeling the extruded portion with a tape, and visually determining the peeling of the film. Both flat plate and processed part adhesion were rated according to the following criteria.

10 points: no peeling 9 points: peeling area of 3% or less 8 points: peeling area of more than 3% and 5% or less 7 points: peeling area of more than 5% and 8% or less 6 points: more than 8% and 10% or less 5 points: Peeling area of more than 10% and 15% or less 4 points: Peeling area of more than 15% and 30% or less 3 points: Peeling area of more than 30% and 50% or less 2 points: Peeling more than 50% and 75% or less Area 1 point: Exfoliation area of more than 75%

Further, as a secondary adhesiveness, after the surface-treated steel sheet was immersed in boiling water for 30 minutes and allowed to stand for 24 hours, the adhesiveness of the coating film after Olgaselect 100 was applied by the above-described method was examined.

4. Fingerprint resistance Fingerprints were adhered to the film of the surface-treated steel sheet, and the visibility of the fingerprints was visually judged and scored. As for the score, 5 indicates that no fingerprint mark is visible, 4 indicates that the fingerprint mark is very slight, 3 indicates that the fingerprint mark is visible, 2 indicates that the fingerprint mark is noticeable, and 1 indicates that the fingerprint mark is very noticeable.

5. Ethanol resistance Press oil was impregnated with gauze and applied onto the film of the surface-treated steel sheet. This oil was wiped off with gauze impregnated with ethanol, and the remaining traces of the film were visually judged and scored. In order to clean oil stains and the like, an operation of wiping with ethanol is sometimes performed. At this time, the test is performed to evaluate whether or not the film is damaged. The rating was 5: no trace, 4: very slight trace, 3: trace, 2: trace is noticeable, 1: trace is very noticeable.

6. Corrosion resistance (SST) Flat plate (sealed end and back of steel plate as cut)
And a 7mm processed part of Erichsen (the end face and the back face of the steel sheet extruded 7mm by Erichsen are sealed) and a cross cut part (the end face of the steel sheet that is scratched like a cross to the depth reaching the base metal plate with a cutter knife) And a seal on the back surface), a salt spray test (as defined in JIS Z 2371) was performed for 168 hours on a flat plate and a 7 mm Ericksen processed portion, and for 120 hours on a cross cut portion. The evaluation criteria were as follows.

Evaluation criteria for flat plate and Ericksen 7 mm processed part 10 points: no abnormality 9 points: between 10 and 8 points 8 points: slight white rust generated 7 to 6 points: between 8 and 5 points 5 points : White rust occurred on half of the area 4 to 2 points: Between 5 and 1 point 1 point: White rust occurred on the entire surface

Evaluation criteria for cross cut portion The average value of the maximum values of the rust progress widths on the four sides of the cross cut portion is: ：: 10 mm or less ：: 10 to 15 mm ： １: 15 to 20 mm ×: 20 mm or more

In the examples, the lower and upper rust-preventive coatings were thinner in Examples 1 and 46, and the fingerprint resistance and the corrosion resistance were slightly inferior. Inferiorly, the corrosion resistance was slightly poor in Example 51 in which the amount of ammonium vanadate added in the lower and upper rust preventive films was small, and the corrosion resistance was slightly inferior in Example 13 in which the amount of thiourea added in the upper rust preventive film was small. Example 53 in which the amount of ammonium vanadate added was small.
In Examples 10 and 59, the corrosion resistance was slightly inferior, and the corrosion resistance was slightly poor in Examples 10 and 59, and in Examples 11 and 58 where the amount of silica was not added in the lower rust prevention film, the corrosion resistance was slightly poor. In Examples 18 and 63 where the amount of silica added in the rust film was small, the corrosion resistance was slightly poor, and in Examples 20 and 65 where the amount of silica was not added in the upper rust preventive film, the corrosion resistance was slightly poor and the amount of ammonium vanadate added in the upper rust preventive film. In Examples 54 and 88, which have a large amount of ethanol, the ethanol resistance is slightly inferior, and in Examples 44 and 88, in which the baked plate temperature of the upper rust-preventive film is low, the ethanol resistance is slightly inferior, but both are practically usable. According to the present invention, a surface-treated steel sheet having excellent corrosion resistance, adhesion to a top coat, fingerprint resistance, ethanol resistance, and galling resistance can be obtained even in an example in which the plating of the original plate is changed.

On the other hand, as examples which are not within the scope of the present invention, in Comparative Examples 1 to 3 in which the lower and upper rust preventive films are thin, the fingerprint resistance and corrosion resistance are inferior, and the thiol in the lower and upper rust preventive films is low. In Comparative Example 4 in which urea and ammonium vanadate were not added, adhesion and corrosion resistance were poor, and in Comparative Example 5 in which the amount of thiourea in the lower and upper rust preventive films was small, the corrosion resistance was poor, and vanadate in the lower and upper rust preventive films. In Comparative Example 6 in which the amount of added ammonium was small, adhesion and corrosion resistance were poor, and in Comparative Examples 7 and 1 in which the amount of added phosphate ions in the lower rust-preventive film was large.
Comparative Examples 1 and 15 are inferior in corrosion resistance and have a large amount of phosphate ions in the upper rust preventive film. Comparative Examples 8, 12 and 16 are inferior in corrosion resistance and ethanol resistance and comparative examples have a large amount of silica in the lower rust preventive film. 9, 13, and 17 are inferior in corrosion resistance and adhesion,
Comparative Examples 10 and 1 in which the amount of silica added in the upper rust-preventive film was large.
In Nos. 4 and 18, the corrosion resistance, adhesion and ethanol resistance are inferior.

[0084]

[Table 1]

[0085]

[Table 2]

[0086]

[Table 3]

[0087]

[Table 4]

[0088]

[Table 5]

[0089]

[Table 6]

[0090]

[Table 7]

[0091]

[Table 8]

[0092]

As described above, according to the present invention,
It is possible to use a non-chromium type surface-treated metal material which does not contain harmful hexavalent chromium and has excellent corrosion resistance.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Yujiro Miyauchi 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Co., Ltd. (72) Inventor Akira Takahashi 1 Kimitsu, Kimitsu-shi, Chiba Nippon Steel Co., Ltd. (72) Inventor Toshiaki Shimakura 4-1-1-15 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint Co., Ltd. (72) Katsuyoshi Yamazoe 4-1-1-15 Minamishinagawa, Shinagawa-ku, Tokyo Japan Paint Inside the corporation

Claims (5)

[Claims] 1. A lower rust-preventive film containing an inhibitor component formed on a surface of a metal material, and further formed thereon.
The lower rust-preventive film having an inhibitor component and an upper rust-preventive film having a thickness of 0.1 to 5 μm and having a solid content of (1) 100 parts by weight of the organic resin and a thiocarbonyl group of the inhibitor component. 0.2 to 500 parts by weight of a compound contained, or (2) 100 to 100 parts by weight of an organic resin and 0.2 to 200 parts by weight of a vanadate compound as an inhibitor component, and the upper anticorrosive film has a thickness of 0.1 to 5 μm. In terms of solid content, (3) 100 parts by weight of an organic resin and 0.1 to 50 parts by weight of a thiocarbonyl group-containing compound of an inhibitor component, or (4) 100 parts by weight of an organic resin and a vanadate compound 0 of an inhibitor component 0.1 to 20 parts by weight of a non-chrome type surface-treated metal material. 2. The lower rust-preventive film is a film containing the solid content of (1), and the lower rust-preventive film further comprises 0.1 to 20%.
0 parts including (PO ₄ as) of at least one or more of the inhibitor component and 1 to 500 parts by weight of fine silica phosphate compound of a non-chromium type surface treated metal sheet according to claim 1, wherein. 3. The lower rust-preventive film is a film containing a solid content of (2).
0 parts by weight of an inhibitor component of a thiocarbonyl group-containing compound, 0.1 to 200 parts by weight (as PO ₄ ) of an inhibitor component of a phosphoric acid compound, and 1 to 500 parts by weight of at least one of fine silica particles. The non-chromium type surface treated metal sheet according to claim 1. 4. The upper rust-preventive film is a film containing the solid content of (3), and the upper rust-preventive film further comprises 0.01 to 2%.
_4. Non-chromium according to any one of claims 1 to 3, comprising 0 parts by weight (as PO4) of an inhibitor component of a phosphoric acid compound and at least one of 1 to 500 parts by weight of finely divided silica. Mold surface treated metal material. 5. The upper rust-preventive film is a film containing the solid content of (4), and the upper rust-preventive film further comprises 0.1 to 50%.
At least one of an inhibitor component of a thiocarbonyl group-containing compound, 0.01 to 20 parts by weight (as PO ₄ ) of an inhibitor component of a phosphoric acid compound and 1 to 500 parts by weight of finely divided silica. The non-chrome type surface-treated metal material according to any one of claims 1 to 3.