JPH11124544A - Metal surface treatment composition and surface-treated metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal surface treatment composition which forms, when forming a protecting film on a metal plate directly or through other layers, a film having a high hardness, scratch resistance and a good processability, and a surface-treated metal plate treated with such composition. SOLUTION: A metal surface treatment composition contains an organic metal compound of the formula: M(OR<1> )n (wherein M is a metal element; each R<1> is identical to or different from each other and represents a hydrogen atom, a lower alkyl group or an acyl group; and n is identical to the valence number of the metal element M) and/or a hydrolyzed condensate thereof, an amino group-containing silane coupling agent, a compound containing, within the molecule, a functional group which reacts with the amino group and a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for metal surface treatment capable of forming a film having high hardness and excellent scratch resistance, and a surface-treated metal sheet treated with the composition.

[0002]

2. Description of the Related Art Metal materials are used in various fields such as furniture, building materials (interior materials, exterior materials), automobiles, various containers, etc. because of their excellent durability, strength, rigidity and the like. At this time, in order to improve corrosion resistance, protect the metal surface, or improve the appearance, in addition to a base treatment such as a chromate treatment, a surface treatment such as metal coating such as plating, painting, and lamination is performed.

[0003] The production of metal sheets in which a polymer film and a metal material are previously combined by painting or the like is increasing year by year. However, such a polymer protective film is required to have various characteristics depending on the use of the metal sheet. Is done. For example, there are mechanical properties such as hardness, scratch resistance and workability, chemical properties such as adhesion, chemical resistance, water resistance and heat resistance, and properties relating to appearance such as stain resistance and sharpness. All of these properties are important, but if the protective film is scratched, the metal substrate will be exposed and the protective effect of the film lamination will not work at all, so it has high hardness and abrasion resistance, and also has good workability. However, a good protective film is required.

[0004]

Therefore, according to the present invention, when a protective film is formed directly on a metal plate or via another layer, it has high hardness and abrasion resistance and has good workability. An object of the present invention is to provide a metal surface treatment composition capable of forming a film, and to provide a surface-treated metal sheet treated with such a composition.

[0005]

The composition for metal surface treatment according to the present invention comprises an organometallic compound (I) represented by the following general formula and / or a hydrolyzed condensate thereof: M (OR ¹ ) _n . (Wherein M is a metal element, R ¹ may be the same or different and represents a hydrogen atom, a lower alkyl group or an acyl group, and n coincides with the valence of the metal element M) Amino group-containing silane coupling The greatest feature is that the composition contains the agent (II), the compound (III) having a functional group capable of reacting with an amino group in the molecule, and a solvent.

M in the organometallic compound (I) is Si, T
It is preferably one of i, Zr, and Al. When the compound (III) has at least one epoxy group as a functional group capable of reacting with an amino group, or has two or more functional groups capable of reacting with an amino group, silane coupling It is preferable because it can react quickly with the amino group in the agent (II). Compound (III)
However, if the compound has an aromatic ring or its hydrogenated ring in the molecule, the water resistance of the film is further improved.

The present invention also includes a surface-treated metal plate in which a cured product layer made of the metal surface treatment composition is formed directly on the metal plate or via another layer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The metal surface treatment composition of the present invention has high hardness and excellent scratch resistance, and can form a film having flexibility and excellent adhesion to a substrate. Even if the metal is processed after the formation of the film, no cracking or peeling occurs. Further, this film is excellent in heat resistance, transparency, moisture resistance, solvent resistance and the like. Therefore, protecting the metal surface for a long time,
Corrosion resistance and durability can be improved. This will be described in detail below.

One of the essential components of the metal surface treatment composition of the present invention is an organometallic compound (I) represented by the following general formula and / or a hydrolytic condensate thereof. M (OR ¹ ) _n (I) (wherein M is a metal element, R ¹ may be the same or different and represents a hydrogen atom, a lower alkyl group or an acyl group, and n is the valence of the metal element M) Matches)

The metal element is preferably Si, Ti, Zr or Al. Specifically, in the above formula, M is Si, such as tetrahydroxysilane, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraacetoxysilane, or the like; Titanium tetraethoxide, M in which M is Ti, titanium Tetraisopropoxide, titanium tetrabutoxide, etc .;
Zirconium tetraethoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide and the like; aluminum triethoxide, aluminum triisopropoxide, aluminum tributoxide and the like in which M is Al; and one or two of these. The above can be used.

In order to adjust the flexibility of the film, a silane compound (IV) represented by the following general formula (IV) can be used instead of a part of the organometallic compound (I). R ² _p Si (OR ³ ) _q (IV) (wherein R ² may be the same or different and is directly bonded to a hydrogen atom, a lower alkyl group, an aryl group, an unsaturated aliphatic residue or a carbon chain) Represents a functional group other than an amino group,
³ may be the same or different and represents a hydrogen atom, a lower alkyl group or an acyl group;
And m + n is 4. )

Specific examples of the silane compound (IV) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,
n-propyltrimethoxysilane, n-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- Mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylsilanol, and the like, One or more of these can be used.

However, if the amount of the silane compound (IV) used is too large, the resulting film may be inferior in density and may have poor abrasion resistance and chemical resistance.
Is preferably 10% by weight or less, and more preferably 5% by weight or less, based on the organometallic compound (I).

In order to prevent evaporation of the organometallic compound (I) when the metal surface treatment composition is coated on a substrate and then dried, the organometallic compound (I) is hydrolyzed and condensed in advance to obtain a high molecular weight compound. It is preferable to make it. Silane compounds
(IV) and the amino group-containing silane coupling agent described later (II)
And co-hydrolysis condensation. In the (co) hydrolysis condensation reaction, a known catalyst can be used, and the reaction is advantageously performed in a solvent described below.

The second essential component of the metal surface treatment composition of the present invention is an amino group-containing silane coupling agent (II) having an amino group and a hydrolyzable group in the molecule. Amino group-containing silane coupling agent (II) is the organometallic compound
In addition to performing a cohydrolytic condensation reaction with (I), the compound also reacts with a compound (III) described below. A film formed by adding the compound (III) to only the organometallic compound (I) or only the amino group-containing silane coupling agent (II) is not preferable because it has low hardness. Further, when a film is formed only with the organometallic compound (I) and the amino group-containing silane coupling agent (II), the film becomes brittle and hard, resulting in poor flexibility. Organometallic compound (I) and amino group-containing silane coupling agent (I
By combining the three components of (I) and the compound (III), the resulting film is appropriately three-dimensionally cured, and has high hardness and excellent scratch resistance.

Specific examples of the amino group-containing silane coupling agent (II) include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane. Ethoxysilane, N-β
-(Aminoethyl) -γ-aminopropyltriisopropoxysilane, N-β- (aminoethyl) -γ-aminopropyltributoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N
-Β- (aminoethyl) -γ-aminopropylmethyldiethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldiisopropoxysilane, N-β-
(Aminoethyl) -γ-aminopropylmethyldibutoxysilane, N-β- (aminoethyl) -γ-aminopropylethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropylethyldiethoxysilane, N
-Β- (aminoethyl) -γ-aminopropylethyldiisopropoxysilane, N-β- (aminoethyl) -γ
-Aminopropylethyldibutoxysilane, N-β-
(N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) −
γ-aminopropyltriisopropoxysilane, N-β
-(N-vinylbenzylaminoethyl) -γ-aminopropyltributoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (N-vinylbenzylaminoethyl ) -Γ-aminopropylmethyldiethoxysilane, N
-Β- (N-vinylbenzylaminoethyl) -γ-aminopropylmethyldiisopropoxysilane, N-β-
(N-vinylbenzylaminoethyl) -γ-aminopropylmethyldibutoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylethyldimethoxysilane, N-β- (N-vinylbenzylaminoethyl ) -Γ-aminopropylethyldiethoxysilane,
N-β- (N-vinylbenzylaminoethyl) -γ-aminopropylethyldiisopropoxysilane, N-β-
(N-vinylbenzylaminoethyl) -γ-aminopropylethyldibutoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ
-Aminopropyltributoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldiisopropoxysilane, γ-aminopropylmethyldibutoxysilane, γ-aminopropylethyldimethoxysilane , Γ-aminopropylethyldiethoxysilane, γ-
Examples thereof include aminopropylethyldiisopropoxysilane, γ-aminopropylethyldibutoxysilane, and γ-aminopropyltriacetoxysilane, and one or more of these can be used.

The amount of the organometallic compound (I) and the amino group-containing silane coupling agent (II) used is 5 to 5 amino acid-containing silane coupling agents (II) based on the organometallic compound (I).
Preferably it is 200% by weight. If the amount of the amino group-containing silane coupling agent (II) is less than 5% by weight, the flexibility of the film is reduced, and the moldability is sometimes not so good. When used in excess of 200% by weight, the adhesion to the metal surface or other layers tends to be poor. More preferably, the amount of the amino group-containing silane coupling agent (II) used is 7 to 200% by weight based on the weight of the organometallic compound (I).
The most preferred range is from 7 to 125% by weight.

The metal surface treatment composition of the present invention also contains, as an essential component, a compound (III) having a functional group capable of reacting with the amino group of the amino group-containing silane coupling agent (II). Compound (III) is a cross-linking component and has a function of adjusting the degree of three-dimensional curing, imparts flexibility to the film, and improves scratch resistance. The functional group capable of reacting with the amino group of the compound (III) includes an epoxy group, a carboxyl group, an isocyanate group, an oxazolinyl group, a hydroxyl group and the like. This functional group is preferably plural in compound (III),
In that case, the functional groups may be the same or different. The epoxy group is the most reactive among the above functional groups. To improve the water resistance of the film, the compound (III)
Preferably has an aromatic ring or a hydrogenated ring thereof.

Specific examples of the compound (III) usable in the present invention include ethylene glycol diglycidyl ether,
Diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, nonaethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6- Aliphatic diglycidyl ethers such as hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and glycerol diglycidyl ether; glycerol triglycidyl ether;
Diglycerol triglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate,
Polyglycidyl ethers such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; aliphatic or aromatic diglycidyl esters such as adipic acid diglycidyl ester and o-phthalic acid diglycidyl ester; bisphenol A diglycidyl ether; Resorcin diglycidyl ether, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, and compounds represented by the following formula

[0020]

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Glycidyls having an aromatic ring or a hydrogenated ring thereof (including a nuclear-substituted derivative); or oligomers having a glycidyl group as a functional group (for example, in the case of bisphenol A diglycidyl ether oligomer, Can be expressed);

[0022]

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Isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, 1,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate;
Dicarboxylic acids such as tartaric acid and adipic acid; polymers containing a carboxyl group such as polyacrylic acid; and polymers containing an oxazolinyl group. One or more of these can be used. In addition, the compound (I
Of the compounds in II), compounds having an aromatic ring or a hydrogenated ring thereof (including a nuclear-substituted derivative) have an effect of further improving the water resistance of the film.

Further, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane,
(3,4-epoxycyclohexyl) ethyltriisopropoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, γ-glycidoxy Propyltrimethoxysilane, γ
Epoxy group-containing silane coupling agents such as glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxysisilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane Isocyanate group-containing silane coupling agents such as γ-isocyanopropyltrimethoxysilane, γ-isocyanopropyltriethoxysilane, γ-isocyanopropylmethyldimethoxysilane, and γ-isocyanopropylmethyldiethoxysilane; (III) having a functional group capable of reacting with a group
And one or more of these can be used.

In the compound (III), the functional group equivalent (Y) in the compound (III) is Y / Y with respect to the functional group equivalent (X) in the amino group-containing silane coupling agent (II). It is recommended to use X as 0.01 to 1.0. Preferably, Y / X is in the range of 0.05 to 0.7, more preferably 0.05 to 0.3. Y / X is 0.01
If it is smaller, the flexibility of the film tends to be insufficient, and Y /
When X exceeds 1.0, hardness and heat resistance may be reduced.

The metal surface treatment composition of the present invention contains a solvent and is in the form of a solution. This is because the presence of the solvent facilitates the hydrolysis-condensation reaction and also facilitates handling when coating on a metal substrate. The solvent is not particularly limited, but a solvent capable of dissolving or dispersing the components of the compounds (I) to (III) is preferable. For example, alcohols such as methanol, ethanol, 2-propanol, butanol and ethylene glycol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene, benzene and xylene, hexane, heptane, octane and the like Hydrocarbons, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, propyl ether, water and the like, and one or more of these can be used as a mixture.

As described above, the composition for metal surface treatment of the present invention comprises a composition essentially comprising an organometallic compound (I), an amino group-containing silane coupling agent (II), a compound (III) and a solvent. Things. The organometallic compound (I), the amino group-containing silane coupling agent (II), the silane coupling agent among the compounds (III), and the silane compound (IV) used as required have a hydrolyzable group. Therefore, it is recommended that the (co) hydrolysis-condensation reaction be allowed to proceed before coating using each alone or two or more of these. When these compounds are made to have a high molecular weight by hydrolysis and condensation, the film formability is improved, and the uniformity and smoothness of the obtained film are further improved.

The (co) hydrolysis-condensation reaction proceeds with moisture in the air, but is preferably carried out in the above-mentioned solvent, since it can be used as it is as a metal surface treatment composition in the coating step. The reaction may be performed by adding a known acid or base as a reaction catalyst.

The method for preparing the metal surface treatment composition is not particularly limited, but the amino group-containing silane coupling agent (II)
When the organometallic compound (I) or a hydrolytic condensate thereof is added after the amino group of the compound (III) is reacted with the functional group in the compound (III), the stability of the composition is improved. The composition includes:
Various inorganic and organic additives such as a curing catalyst, a wettability improver, a plasticizer, an antifoaming agent, and a thickener may be added as needed, as long as the effects of the present invention are not impaired.

Since the composition for metal surface treatment of the present invention can form a transparent film having high hardness and excellent scratch resistance, basically, a top coat,
It is preferably applied as a so-called hard coat layer. In addition, because it has excellent adhesion to a metal substrate, the composition of the present invention is directly coated on a metal plate,
Only by curing and drying, a metal plate having a cured product layer having high hardness and excellent scratch resistance can be obtained. The composition of the present invention is applicable not only to metal plates but also to metal products of various shapes such as metal foils, pipes, wires, and the like. Further, since the composition of the present invention has excellent adhesion to metals, it can be used as a primer for adhesion of various paints.

The present invention also includes a surface-treated metal plate treated with the above composition. The surface-treated metal plate is, that is, by coating the composition of the present invention directly on the metal plate or on another layer formed on the metal plate, and then drying and curing the metal plate. A film (cured material layer) was formed thereon. As the type of metal plate,
An iron plate, various steel plates, a zinc alloy plate, an aluminum plate, a titanium plate, a copper plate, an alloy plate of these, or a plate coated with a metal coating such as plating can be used. In particular, the composition of the present invention comprises a composition of the present invention on the surface of stainless steel, since a transparent film that adheres well to metals such as stainless steel having poor adhesion to ordinary organic paints is formed. By forming a hardened material layer, it is possible to maintain the gloss without damaging the stainless steel. The metal plate may be subjected to a known anticorrosion base treatment (chromate treatment, phosphate conversion treatment, etc.). Further, if necessary, another layer such as a coating layer or a film layer for imparting a design property may be interposed between the metal plate and the cured product layer made of the composition of the present invention. Another layer can be provided on the cured product layer comprising the composition of the present invention.

The method for coating the metal plate with the composition for metal surface treatment is not particularly limited, and examples thereof include roll coating, dip coating, bar coating, die coating, spray coating, and the like.
A curtain flow coating method or a combination thereof can be employed.

After coating the composition, it is dried to harden the coating. The drying / curing temperature at this time is 1
A temperature of about 00 to 200 ° C. is preferable because a dense cured film can be formed.

The thickness of the film (cured material layer) after drying is 0.1 mm.
A range of 1 to 10 μm is suitable. Preferably 0.3 to
It is 5 μm, more preferably 0.5 to 3 μm. If the coating is thinner than 0.1 μm, the scratch resistance becomes insufficient and the object of the present invention cannot be achieved. Conversely, if the thickness is more than 10 μm, cracks may occur in the film, and the surface protection effect becomes insufficient.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention.
Modifications and alterations that do not depart from the spirit described below are all included in the technical scope of the present invention. The evaluation method of the characteristics used in the examples is as follows.

[Pencil hardness] The film formed on the steel plate was measured according to JIS K5400.

[Scratch resistance] The film formed on the steel plate was rubbed vigorously five times with # 000 steel wool, and the state of the film being scratched was visually observed. The one with the mark was marked as x.

[Cross-cut test] The coating formed on the steel plate was subjected to the cross-cut tape method of JIS K5400 according to the cross cut tape method.
Tests and evaluations (10-point method) were performed.

[Cross-Ericsen] A cross-cut was formed on the film formed on the steel sheet according to JIS K5400, extruded with Erichsen by 5 mm, and then taped. Thereafter, the test and evaluation were performed in the same manner as in the above grid test.

[Chemical resistance] The coating formed on the steel sheet was subjected to a rubbing test 100 times with xylene, and the coating having no change was evaluated as "O", and the coating whitened or dissolved was evaluated as "X". did.

Example 1 A flask equipped with a stirrer, thermometer and cooler was charged with N-
After charging 100 g of β- (aminoethyl) -γ-aminopropyltriethoxysilane and 80 g of ethanol and raising the temperature to 70 ° C., bisphenol A diglycidyl ether 1
0.0 g was added dropwise over 30 minutes. After aging at 70 ° C. for 3 hours, the mixture was cooled to room temperature, and 5 g of water
0 g of the mixture was added, and the mixture was stirred at room temperature for 1 hour and then aged.
The hydrolysis reaction was allowed to proceed. Next, a mixed solution of 50 g of tetraethoxysilane and 150 g of ethanol was added to obtain a composition 1 for metal surface treatment.

The composition 1 for metal surface treatment was coated on a stainless steel plate (SU) so that the thickness after drying was 2.0 μm.
S304) and dried at 200 ° C. for 1 minute. The resulting film was transparent. Table 1 shows the results of the property evaluation test of the surface-treated steel sheet.

Examples 2 to 4 and Comparative Examples 1 to 3 As shown in Table 1, a surface-treated steel sheet was prepared in the same manner as in Example 1 except that the composition of the metal treatment composition and the type of the metal plate were changed. I got The evaluation results are also shown in Table 1. In Table 1, the following abbreviations were used to represent the composition for metal surface treatment.

MS: tetramethoxysilane ES: tetraethoxysilane M-51: "M-silicate 51" (manufactured by Tama Chemical;
MTEOS: Methyltriethoxysilane (for comparative example) TBO: Titanium tetrabutoxide ZBO: Zirconium tetrabutoxide AiP: Aluminum triisopropoxide AEAPTES: N-β (aminoethyl) -γ-aminopropyltriethoxy Silane APTMS: γ-aminopropyltrimethoxysilane APTES: γ-aminopropyltriethoxysilane PhAPTMS: N-phenyl-γ-aminopropyltriethoxysilane BisADGE: Bisphenol A diglycidyl ether RDGE: Resorcinol diglycidyl ether EGDGE: Ethylene glycol di Glycidyl ether HDI: Hexamethylene diisocyanate PhDGE: Phenyl glycidyl ether EO : Ethanol MOH: methanol POH: 2-propanol

[0045]

[Table 1]

[0046]

The composition for metal surface treatment of the present invention is obtained by combining an all-functional organometallic compound with an amino group-containing silane coupling agent and a compound having reactivity with an amino group. In addition to having high hardness and excellent scratch resistance, a film having flexibility and excellent substrate adhesion can be formed. For this reason, even if metal processing is performed after film formation, cracks occur,
There is no peeling. Further, this film is excellent in heat resistance, transparency, moisture resistance, solvent resistance and the like. Therefore, the surface-treated metal plate having a cured product layer formed of the composition on the surface can maintain a beautiful and scratch-free surface for a long period of time.

Claims (6)

[Claims] An organometallic compound represented by the following general formula:
(I) and / or a hydrolytic condensate thereof, M (OR ¹ ) _n ... (I) (wherein M is a metal element, R ¹ may be the same or different and is a hydrogen atom, a lower alkyl group or an acyl group) Wherein n is the same as the valence of the metal element M) Amino group-containing silane coupling agent (II), compound having a functional group capable of reacting with an amino group in the molecule (I
II) and a solvent. 2. M in the organometallic compound (I) is Si, T
The metal surface treatment composition according to claim 1, which is any one of i, Zr, and Al. 3. The metal surface treatment composition according to claim 1, wherein the compound (III) has at least one epoxy group as a functional group capable of reacting with an amino group. 4. The metal surface treatment composition according to claim 1, wherein the compound (III) has two or more functional groups capable of reacting with an amino group. 5. The metal surface treatment composition according to claim 1, wherein the compound (III) is a compound having an aromatic ring or a hydrogenated ring thereof in the molecule. 6. A cured product layer comprising the metal surface treatment composition according to any one of claims 1 to 5,
Alternatively, a surface-treated metal plate formed through another layer.