JP2000234187A - Surface treatment agents and surface treated metal materials - Google Patents

Abstract

(57) [Summary] A surface treatment agent capable of imparting excellent corrosion resistance to a metal material and forming a film excellent in electromagnetic wave shielding properties and weldability without using chromium. Provide a surface-treated metal material having a formed film. SOLUTION: (A) Organic resin and (B) Si, Ti, Z
It contains a coupling agent containing a metal selected from r, V, and Mo, and (C) a conductive substance having a particle size of 0.1 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment agent and a surface treatment metal material, and more particularly to a surface treatment agent suitable for producing a surface treatment metal material having excellent flat plate corrosion resistance, electromagnetic wave shielding properties and weldability. The present invention relates to a metal material having a film formed by the surface treatment agent.

[0002]

2. Description of the Related Art Conventionally, galvanized steel sheets such as galvanized steel sheets and galvanized aluminum steel sheets have been subjected to a surface treatment to impart corrosion resistance (rust prevention) to prevent the generation of white rust due to corrosion. . Various chemical conversion treatments, coatings, and the like have been conventionally known as such metal surface treatments. Generally, a chromate treatment capable of obtaining corrosion resistance at low cost is widely performed. In addition, since the adhesion is poor when a paint is directly applied to a metal, chromate treatment is widely used as a base treatment for coating. However, chromate treatment has a problem of waste liquid treatment containing hexavalent chromium, and it is necessary to perform special wastewater treatment.
There was a disadvantage that the cost was increased. Therefore, a processing technique that does not use chromium is required, and many techniques have been proposed to date.

For example, metals other than chromium (molybdenum,
Polymetal oxides such as tungsten (JP-A-57-5)
875) and tannic acid (JP-A-51-2902). In addition, a surface treatment agent containing a hydroxyl group-containing styrene-based water-soluble polymer and a silane coupling agent having an amino group, an epoxy group, and the like (Japanese Patent Application Laid-Open No. 9-241576) has been proposed.

[0004] However, in the method using a polymetal oxide, the stable region of the polymetal oxide against steel sheet corrosion is narrower than that of chromium, and it is impossible to obtain the same corrosion resistance as in the case of chromate treatment. Further, in the method using tannic acid, there is a problem that coloring by tannic acid occurs when sufficient corrosion resistance is to be obtained. Regardless of which method is used, the treated steel sheet does not have a self-repairing action like a chromate film, and if the film is damaged by press working, bending, or the like, the corrosion resistance is significantly reduced.

The surface treatment composition disclosed in Japanese Patent Application Laid-Open No. 9-241576 includes a silane coupling agent component having a reactive functional group such as an active hydrogen-containing amino group and an epoxy group, and a benzene ring-based component. It consists of a polymer resin. However, in this case, there is a problem that the thermal and chemical stability of the benzene ring is too high, resulting in poor weldability.
Under such circumstances, the electromagnetic waves of electrical products, especially those that generate electromagnetic waves such as microwave ovens, are shielded.
In the field of metal materials used for the purpose of development, it is desired to develop a surface treatment agent that can form a film that has electromagnetic wave shielding properties and at the same time imparts corrosion resistance and weldability to metal materials without using chromium. Until now, there has been no surface treatment agent capable of obtaining such a film.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and uses chromium as a film which imparts excellent flat plate corrosion resistance to a metal material and which is also excellent in electromagnetic wave shielding properties and weldability. It is an object of the present invention to provide a surface treatment agent that can be formed without using the same, and to provide a metal material having a film formed by the surface treatment agent.

[0007]

Means for Solving the Problems The present invention has been accomplished by finding that the above object can be achieved by a surface treatment agent containing an organic resin, a conductive substance, and a metal-containing coupling agent. That is, the surface treatment agent according to the present invention,
(A) Organic resin and (B) Si, Ti, Zr, V, Mo
And (C) a conductive material having a particle size of 0.1 μm or less. The present invention also provides a surface-treated metal material having a film formed by such a surface treatment agent on at least one surface.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The surface treating agent according to the present invention comprises the following (A) an organic resin, (B) a coupling agent containing a metal selected from Si, Ti, Zr, V, and Mo; μ
m or less of a conductive substance. In the present invention,
As the organic resin (A), known organic resins can be widely used, but it is preferably water-soluble. This is because a water-soluble organic resin usually has a polar group such as a carboxyl group, a hydroxyl group, and a phosphoric acid-derived group, and a dense film is easily obtained by interaction with a conductive substance.
The polar group contained in the organic resin may be one kind or two.
There may be more than one species.

The water-soluble organic resin is obtained by polymerizing or copolymerizing a polymerizable compound having a polar group, even if the polymer obtained in advance is made water-soluble by addition modification of a polar group compound. And the manufacturing method is not limited at all. When such a water-soluble organic resin is produced, a compound having a group which becomes a water-soluble polar group finally under acidic conditions can be used as a polymerization raw material or a modifier, for example, a carboxylate or the like (hereinafter referred to as a carboxylate). These include a carboxyl group), an epoxy group, and a compound having a reducing hydroxyl group such as aldehyde and ketone (hereinafter also referred to as a hydroxyl group).

In the present invention, examples of the organic resin (A) include a hydroxyl group-containing epoxy resin, an acid-modified epoxy resin, and a polymer or copolymer of a compound having a polar group and having an ethylenically unsaturated bond. . The unsaturated compound may have a plurality of the same or different polar groups in one molecule. Examples of the ethylenically unsaturated bond include a vinyl group, a vinylidene group, an acryloxy group, and a methacryloxy group.

As the compound having an ethylenically unsaturated bond having a polar group, specifically, for example, acrylic acid,
Methacrylic acid (hereinafter sometimes simply referred to as (meth) acrylic acid), monocarboxylic acids such as crotonic acid, dicarboxylic acids such as itaconic acid, maleic acid, and fumaric acid; alkali metal salts and ammonium salts of these carboxylic acids , Organic amine salts, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate,
3-hydroxybutyl (meth) acrylate, 2,2-bis (hydroxymethyl) ethyl acrylate, 2,3-dihydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycidyl (Meth) acrylate, allyl glycidyl ether,
β-methylglycidyl (meth) acrylate, 3,4-
(Meth) acrylic esters such as epoxycyclohexylmethyl (meth) acrylate, allyl alcohols, acrylamides such as N-methylolacrylamide, N-butoxymethylol (meth) acrylamide, aldehydes such as acrolein, and hydroxyl groups such as hydroxystyrene Containing aromatic vinyl compounds. As the phosphoric acid-derived group-containing compound, CH ₂ ＣCZ—C (＝ O) — (OR) _m —OP (＝ O)
(OH) ₂ (where Z is H or CH ₃ , and R is C 1-3
Is a linear or branched alkylene group, and m is an integer of 1 or more. ). Examples of this include:

[0012]

Embedded image And the like. Moreover _{CH 2 = CZ-C (=} O) -
_{O (R) n -OP (=} O) (OH) 2 ( where Z is H or CH _3, R is the number 1 or more linear or branched alkylene group having a carbon, n represents 4 or more And an integer.). Among these, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phosphoric acid, a derivative-containing compound, and the like are preferable.

The organic resin (A) may contain a unit derived from another polymerization component not having any of the above polar groups. The other polymerization components are not particularly limited as long as they do not impair the effects of the present invention, and include the above-mentioned ethylenically unsaturated compounds and copolymerizable compounds, for example, styrene and aromatic vinyl compounds such as vinyltoluene. , Methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate,
Examples include alkyl (meth) acrylates such as 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and cyclohexyl (meth) acrylate. Among these, styrene that can impart hydrophobicity to the organic resin (A), methyl acrylate, butyl methacrylate, and 2-ethylhexyl methacrylate that can impart flexibility are preferable. Organic resin (A)
May contain two or more types of units derived from such other polymerization components. Specific examples of the polar group-containing epoxy resin include a hydroxyl group-containing bisphenol-type epoxy resin represented by the following formula.

[0014]

Embedded image

Further, an acid-modified product of a hydroxyl group-containing bisphenol-type epoxy resin may also be used. As an example of the case where a saturated dicarboxylic acid is used as an acid denaturing agent, the one modified with sebacic acid is shown by the following formula 1. As an example of the case where an acid anhydride is used as an acid denaturing agent, the case of modification with maleic anhydride is shown in the following formula 2.

Embedded image

In the present invention, the organic resin (A) is a homopolymer of a compound having an ethylenically unsaturated bond having a polar group as described above, a copolymer of these unsaturated compounds, and a polymer having a polar group. It may be a copolymer with an unsaturated compound, a polar group-containing epoxy resin, or the like, or a mixture thereof as appropriate. More specifically, for example, polyacrylic acid, acrylic acid-maleic acid copolymer, butyl methacrylate / copolymer of unsaturated compound containing a phosphoric acid-derived group / styrene copolymer, butyl methacrylate / methacrylic acid / methyl acrylate / Examples include 2-ethylhexyl methacrylate / styrene copolymer and a hydroxyl group-containing epoxy resin. The organic resin (A)
By having the above-mentioned polar group, excellent adhesive strength is exhibited to a metal or a coating film. Particularly, by having a carboxyl group, excellent adhesiveness to a metal, particularly zinc is exhibited. In addition, the carboxyl groups associate with each other to enhance the aggregation effect, and thus impart denseness to the film.

The molecular weight Mw of the organic resin (A) varies depending on the resin and is not particularly limited as long as the viscosity of the organic resin (A) does not decrease the workability of coating the surface treatment agent and the film strength is obtained. Usually, it is desirable that the value in terms of polystyrene by GPC measurement is about 5,000 to 40,000. The glass transition point Tg is 10 to 100.
It is preferable that the temperature is about ° C. The acid value of the organic resin (A) is preferably from 50 to 350. When the acid value is in this range, excellent adhesion to metal is exhibited, and peeling is unlikely to occur during metal material processing after film formation. The acid value is 3
If it exceeds 50, the water resistance of the film is reduced, or the carboxyl groups which contribute to the adhesion to the plating due to the interaction between the carboxyl groups are insufficient, so that the corrosion resistance is reduced.

Further, the surface treating agent of the present invention comprises (B) S
It contains a coupling agent containing a metal selected from i, Ti, Zr, V, and Mo. Coupling agents include amino groups, epoxy groups (glycidoxy groups), vinyl groups, mercapto groups, (meth) acryloyloxy groups,
Known compounds having an acetylacetonate group, various phosphate groups, alkoxy groups, halogens and the like can be widely used. For example, taking a silane coupling agent as an example, γ-aminopropyltriethoxysilane, γ-
Aminopropyltrimethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, N-β
-Aminoethyl-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ
-Glycidoxypropylmethyldimethoxysilane, β-
3,4-epoxycyclohexylethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ
-Methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltris (2-methoxyethoxy)
Silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriacetoxysilane, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, γ-methacrylic Roxypropyltrimethoxysilane and the like. Further, Si in the compounds exemplified as the Si coupling agent is replaced with Ti, Zr, V or Mo.
And the like. Furthermore, Ti coupling agents such as isopropyl tri (dioctyl pyrophosphate) titanate and tetraoctyl bis (ditridecyl phosphate) titanate, and Zr coupling agents such as zirconium butyrate and zirconium acetate are also included.

Of these, Si, Ti, or Zr is contained, and the organic material has a bonding functional group such as an amino group, an epoxy group, an acetylacetonate group, various phosphate groups, and a hydrolyzable alkoxy group reactive with an inorganic material. Those containing a group or the like are preferred. More specifically, γ-glycidoxypropyltrimethoxysilane, isopropyl tri (dioctyl pyrophosphate) titanate, zirconium butyrate, zirconium acetate and the like are preferably used. Two or more of these can be used in combination. In the coupling agent (B) used in the present invention, a part of the above compounds may be condensed.

When the coupling agent (B) is used together with the organic resin (A), they interact (for example, van der Waals bonds), the pseudo-crosslinking density increases, and the adhesion and corrosion resistance of the film are improved. It can be further improved. On the other hand, according to the study of the present inventors, if the content of the coupling agent is too large, the film acts to contain water, and the corrosion resistance is reduced. Therefore, the content of the coupling agent (B) in the surface treatment agent is preferably 1 to 10% by weight, more preferably 2 to 10% by weight, assuming that the total components of the surface treatment agent when dried is 100% by weight. ８8% by weight. In order to sufficiently exhibit the above preferable characteristics, it is desirable that the amount of the coupling agent is 1 to 35 parts by weight, preferably 2 to 27 parts by weight based on 100 parts by weight of the organic resin (A).

The surface treating agent of the present invention must further contain (C) a conductive substance having a particle size of 0.1 μm or less. When the particle size exceeds 0.1 μm, a load is applied to the surface treatment agent film at the time of press molding, and compression and shear deformation are caused. However, detachment of the conductive substance from the surface treatment film at this time tends to occur. . The conductive material of the present invention can be used without particular limitation as long as it is a known conductive material in addition to metal, and may be not only electronic conductive but also ionic conductive. Examples of such a conductive substance include nickel powder, silver powder, iron powder, conductive aluminum, SUS, carbon black, silver oxide, and conductive antimony double oxide. It is desirable that the specific resistance of the conductive material is about 10 ⁻⁴ Ω · cm or less.
In the present invention, carbon black, conductive antimony double oxide and the like are particularly preferably used.

Carbon black has a specific surface area of 20-4.
It is desirably 00 m ² / g. This is because if the specific surface area of the carbon black is less than 20 m ² / g, adhesion to the organic resin (A) is insufficient, so that particles are likely to be detached during press molding. Also 400
Those exceeding m ² / g are not preferred for practical use. A more preferable specific surface area is 30 to 350 m ² / g.

Here, the particle size and specific surface area can be measured as follows. Particle size measurement method: 10 ^{5 with an} electron microscope
The size was doubled, 10 particles were randomly selected, the diameter was measured, and the average value was obtained. Specific surface area measuring method: BET method was used. Nitrogen was adsorbed on the surface and then desorbed, and the amount of desorbed nitrogen was measured by gas chromatography and converted to a specific surface area.

The content of the conductive substance (C) in the surface treatment agent is preferably 10 to 50% by weight, more preferably 10 to 50% by weight, when the total of the components in the surface treatment agent when dried is 100% by weight. Is from 20 to 40% by weight. When the content of the conductive substance (C) is less than 10% by weight, the surface electric resistance of the film increases and the electromagnetic wave shielding property decreases, and when it exceeds 50% by weight, the cohesive force of the film decreases. , Corrosion resistance tends to deteriorate. Further, the organic resin (A) 10
For 0 parts by weight, the amount of the conductive substance (C) is 12 to 16
It is desirably 7 parts by weight, preferably 20 to 135 parts by weight.

The surface treating agent according to the present invention contains the above organic resin (A), silane coupling agent (B) and conductive substance (C). The surface treatment agent is preferably water as a medium, and may further contain an organic solvent compatible with water, such as alcohol. Further, it is preferable not to contain a surfactant for dispersing the resin, such as an emulsion paint. This can avoid adverse effects on the film performance of the surfactant remaining in the film (for example, deterioration of corrosion resistance due to insufficient water resistance of the film due to the surfactant). The dry component concentration in such a surface treatment agent is 10 to 40 from the viewpoint of coating workability.
It is preferable that the amount is about% by weight. The surface treatment agent according to the present invention is generally desirably acidic.

The surface treating agent according to the present invention may optionally contain other components in addition to the components (A) to (C) as long as the object of the present invention is not impaired. (D) Zn, Mg, Zr, Ti, C
a, Ba, Mn, Nb, Sr, Al, Y, Ni, Fe,
A salt of one or more metals selected from Co and W can also be used. Specific examples include phosphates, acid phosphates, nitrates, sulfates, hydrochlorides, acetates, formates, citrates, tartrates and carbonates of these metals. More specifically, zinc phosphate, zinc hydrogen phosphate, magnesium phosphate, aluminum phosphate, calcium hydrogen phosphate,
Nickel (II) phosphate, cobalt (II) phosphate, iron phosphate (I
I), iron (III) phosphate, manganese (II) phosphate, aluminum nitrate, calcium nitrate, zinc nitrate, nickel nitrate (I
I), cobalt (II) nitrate, zirconium (IV) nitrate, aluminum sulfate, magnesium sulfate, zinc sulfate, nickel (II) sulfate, iron (II) sulfate, titanium (IV) sulfate, manganese sulfate (I
I) Aluminum, aluminum chloride, magnesium chloride, calcium chloride, zinc chloride, cobalt (II) chloride, iron (II) chloride, zirconium (IV) chloride, titanium (IV) chloride, manganese (II) chloride, zinc acetate, citrate Examples thereof include zinc oxide, calcium carbonate, cobalt carbonate, molybdic acid, and yttrium. Two or more of these metal salts may be used in combination.

The above metal salt (D) is usually used as a resin component.
(A) 10 to 200 weight parts per 100 weight parts in total
Parts, preferably 20 to 180 parts by weight
desirable. These metal salts are used in aqueous surface treating agents,
n²⁺, Mg²⁺, Zr⁴⁺, Ti⁴⁺, Ca ²⁺, Ba²⁺, Mn
²⁺, Mn⁴⁺, Nb³⁺, Nb⁵⁺, Sr²⁺, Al³⁺, Y³⁺,
Ni²⁺, Ni³⁺, Fe²⁺, Fe³⁺, Co²⁺, Co³⁺, W
⁶⁺And the like to generate cross-linking properties.
Therefore, such metal salts (metal ion
) Further improves the denseness of the film
In addition, corrosion resistance (rust prevention) and scratch resistance are further improved.

It is preferable that the surface treating agent contains (E) at least one selected from phosphoric acids, hydrofluoric acid and hydrogen peroxide. This phosphoric acid is any of phosphoric acid, polyphosphoric acid, hypophosphorous acid, phosphorous acid, tripolyphosphoric acid, hexametaphosphoric acid, primary phosphoric acid, diphosphoric acid, tertiary phosphoric acid, polymetaphosphoric acid, biphosphoric acid There may be. Such a component (E) develops metal etching properties and improves the adhesion of the coating to the metal. The acid (E) is preferably used in an amount of usually 5 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the total amount of the resin component (A). If the amount of (E) exceeds 200 parts by weight, the corrosion resistance tends to decrease.

As an additional component of the surface treating agent, (F) a metal oxide can be used. As the metal oxide, specifically, SiO ₂ , ZnO, MgO, TiO ₂ , Zr
O ₂ , SnO ₂ , Al ₂ O ₃ , Sb ₂ O ₅ , Fe
One or more selected from the group consisting of ₂ O ₃ and Fe ₃ O ₄ can be used. As such a metal oxide, for example, silicate may be used as long as it becomes SiO ₂ at the time of film formation. In the present invention, the metal oxide is desirably used as a colloid (sol) having high film properties.
As such a metal oxide sol, for example, commercially available products such as Snowtex-O and Snowtex-N (manufactured by Nissan Chemical Industries, Ltd.) can be used. These surface treatment agents containing a metal oxide are preferable because the denseness of the film is further improved and the corrosion resistance (rust prevention) is further improved. The metal oxide (F) is used in an amount of usually 5 to 150 parts by weight, preferably 10 to 10 parts by weight, based on 100 parts by weight of the total amount of the resin component (A).
It is desirable to use 0 parts by weight. The additional components as described above can be used in combination as appropriate.

<Surface-treated metal material> The present invention also provides a surface-treated metal material having on its surface at least one surface formed with a film formed by the above-mentioned surface treatment agent. The metal material to be surface-treated is not particularly limited, and the metal material itself does not need to have the electromagnetic wave shielding property. Iron (steel), stainless steel, aluminum and aluminum alloys, as well as zinc-containing metal-plated steel, aluminum-plated steel, tin-plated steel, and the like can be widely used.
Among these, a zinc-containing plated steel sheet can be used. More specifically, examples of the galvanized steel sheet include galvanized steel, galvanized steel, galvanized nickel-plated steel, galvannealed steel, galvalume steel, and the like. These metal materials are not limited to flat plates, and may be band-shaped. Further, the thickness of the sheet is not particularly limited. The metal type, shape, and the like may be appropriately selected according to the application.

Usually, it is desirable to apply the surface treating agent as described above in an amount of about 0.2 to 0.8 g / m ² in terms of the amount of adhesion per metal surface (when dried). This amount of adhesion is an amount per one side in the case of a metal plate. With such an attached amount, the film thickness is usually about 0.3 to 1.2 μm when dried. The surface treatment agent can be performed by a general coating method,
Any method such as roll coating, spray coating, brush coating, dip coating, and curtain flow may be employed. It is desirable to dry the film at a temperature of about 50 to 250 ° C. as the temperature of the metal material. In the case of a metal plate, the coating may be formed on both surfaces or only on one surface. It is preferable that the wire-like material is entirely covered. As described above, the film formed from the surface treatment agent according to the present invention has excellent adhesion and corrosion resistance, has electromagnetic wave shielding properties, and also has excellent weldability.
It is desirable that the electromagnetic wave shielding property of such a film is specifically 1 Ω or less in surface resistance. As long as such characteristics of the present invention are not impaired, an overcoating film may be further provided on this film.

[0032]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. <Evaluation method> The following evaluations were performed on the surface-treated steel sheets (plates) obtained in the examples or comparative examples.

(1) Flat plate corrosion resistance A salt spray test was performed in accordance with JIS Z-2371.
Evaluation was made based on the time required until 5% white rust was generated on the treated surface of the test specimen. ◎ 120 hours or more ○ 100 to 120 hours △ 50 to 100 hours × 0 to 50 hours

(2) Electromagnetic Wave Shielding Property The surface resistance of the test piece was determined by Lovesta MCP-TEST.
It was measured by the two probe method of ER (manufactured by Yuka Denshi). ×: 10Ω or more △: 1Ω or more to less than 10Ω ○: 0.5Ω or more to less than 1Ω ◎: less than 0.5Ω

(3) Weldability Using a CF type (tip 5 mmφ) electrode, pressure of 190 k
g, current 7.8 kA, initial pressurizing time 50 cycles, energizing time 8 cycles, cooling time 30 cycles, conducting a continuous spot test, measuring the tensile strength and nugget diameter, and setting the nugget diameter to 4√t of the plate thickness t. The limit number of hit points that could not be reached was determined. ◎: 3000 points or more ○: 2000 points or more to less than 3000 points △: 1000 points or more to less than 2000 points ×: less than 1000 points

(Examples 1 to 17) Electrogalvanized steel sheet (thickness: 1 mm, Zn adhesion: 20 g / m ² )
(A resin concentration of 20% by weight)
Aqueous solution) was applied on both sides by a roll coater so that the dry weight on one side was 0.5 g / m ^2, and the oven time was 1 hour.
Drying was performed under the condition that the reached plate temperature after 0 sec was 150 ° C. to form a film having a thickness of 0.8 μm. Table 1 shows the evaluation results of the obtained surface-treated steel sheets.

Comparative Example 1 A steel sheet was subjected to the surface treatment in the same manner as in Example 1 except that only the resin 1 was used. Table 1 shows the evaluation results of the obtained surface-treated steel sheets.

[Table 1]

The components in Tables 1 to 3 are shown below. <(A) Organic resin> Resin 1 ... Polyacrylic acid (A-30L manufactured by Toa Gosei Co., Ltd.)
L) (Molecular weight Mw = 50,000) Resin 2 ... Acrylic acid-maleic acid copolymer (A-6310 manufactured by Toagosei Co., Ltd.) (Molecular weight Mw = 20,000) Resin 3 ... Styrene (St) / butyl methacrylate (B
MA) / phosphoric acid-derived group-containing compound ^{* 1} (molecular weight Mw = 10
000)

Embedded image Resin 4: styrene (St) / butyl methacrylate (BMA) / methyl acrylic acid (MAA) / 2-ethylhexyl acrylate (HEMA) = 55/20/15 /
10 (% by weight) (molecular weight Mw = 20,000) and Epicoat 1009 (manufactured by Yuka Shell Epoxy Co., Ltd.) (M
w = 10000) / = 60/40 (% by weight)

Embedded image Epikote 1009

<(B) Coupling agent> Si coupling agent: γ-glycidoxypropyltrimethoxysilane (KBM403 manufactured by Shin-Etsu Silicon Co., Ltd.) Ti coupling agent: isopropyl tri (dioctyl pyrophosphate) titanate (Ajinomoto KR3 manufactured by
8S) Zr coupling agent: zirconium butyrate (Orgatics A60 manufactured by Matsumoto Kogyo Seiyaku Co., Ltd.)

<(C) Conductive substance> Carbon black: # 3030 (manufactured by Mitsubishi Chemical Corporation) Specific surface area: 32 m ² / g, particle size: 0.055 μm Carbon black: # 2300 (manufactured by Mitsubishi Chemical Corporation) (Specific surface area: 300 m ² / g, particle size: 0.013 μm) Sb compound: conductive antimony double oxide CX-Z300H (particle size: 0.08 μm) (manufactured by Nissan Chemical Industries, Ltd.)

<(D) Metal salt> Manganese phosphate (manufactured by Wako Pure Chemical) Magnesium phosphate (manufactured by Wako Pure Chemical) Zinc phosphate (manufactured by Wako Pure Chemical) <E> Phosphoric acid (manufactured by Wako Pure Chemical) Hydrofluoric acid (manufactured by Wako Pure Chemical) Hydrogen peroxide (manufactured by Wako Pure Chemical) <(F)> SiO ₂ (colloidal silica sol, Snowtex O manufactured by Nissan Chemical) ZrO ₂ (manufactured by Nissan Chemical)

(Examples 18 to 20)
A coating film was formed in a dry weight of 0.6 g / m ^{2 in the same} manner as in Example 1 except that the resin 1 was changed to the resin shown in Table 2, and a film having a thickness of 0.9 μm was formed. . Table 2 shows the evaluation results of the obtained surface-treated steel sheets.

(Comparative Examples 2 to 4)
The surface treatment of the steel sheet was performed in the same manner as in Examples 2 and 3, except that only each resin was used. Table 2 shows the evaluation results of the obtained surface-treated steel sheets. (Comparative Example 5) A surface treatment of a steel sheet was performed in the same manner as in Example 1 except that no resin was used.
Table 2 shows the evaluation results of the obtained surface-treated steel sheets. (Comparative Example 6) The surface treatment of the steel sheet was performed in the same manner as in Example 1 except that the resin (Resin 5) having the following structure was used instead of the resin.

[0044]

Embedded image Table 2 shows the evaluation results of the obtained surface-treated steel sheets.

[0045]

[Table 2]

(Examples 21 to 27)
The same coating as in Example 1 was formed except that the type of the metal plate was changed to each metal plate shown in Table 3. Table 3 shows the evaluation results of the obtained surface-treated metal sheets.

[Table 3]

[0047]

The surface treating agent according to the present invention provides an electromagnetic wave shielding property, a corrosion resistance, and the like on a metal surface without using chromium.
A film that imparts weldability can be formed. Further, the surface-treated metal material obtained by using such a surface-treating agent can be widely used for electromagnetic wave shielding, particularly for electric appliances such as home appliances.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Umino 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Inside the Technical Research Institute of Kawasaki Steel Co., Ltd. (72) Inventor Chiyoko Tada 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki (72) Katsuhei Kikuchi, Inventor: 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term (reference) 4D075 AA01 AB01 AC14 AC22 AC57 BB24Z CA25 CA33 DA06 DB01 DB04 DB05 DB07 EA06 EB22 EB33 EB53 EC01 EC45 EC54 4K062 AA01 BA01 BA02 BA08 BA14 BA17 BB03 BC09 BC11 BC12 BC13 CA10 FA09 FA12 GA03 GA08 GA10 5G301 DA18 DA23 DA42 DD02 DD06

Claims (2)

[Claims] 1. An organic resin comprising: (A) an organic resin; and (B) Si, Ti, Z.
A surface treatment agent comprising: a coupling agent containing a metal selected from r, V, and Mo; and (C) a conductive substance having a particle size of 0.1 μm or less. 2. A surface-treated metallic material having a film formed by the surface-treating agent according to claim 1 on at least one surface.