JP6523253B2 - Metal surface treatment agent for galvanized steel, coating method and coated steel - Google Patents

Description

  The present invention relates to a metal surface treatment agent for galvanized steel, a coating method using the metal surface treatment agent, and a coated steel material.

  Conventionally, corrosion prevention treatment with chromate using hexavalent chromate etc. has been widely performed on zinc-plated steel materials etc., and coating with an organic resin is carried out to impart fingerprint resistance, scratch resistance and the like as needed. And then various paints were overcoated.

  In recent years, against the background of rising environmental problems, chromate treatment, which has conventionally been applied to steel materials, is being regulated or prohibited by law. The chromate-treated layer itself has a high degree of corrosion resistance and paint adhesion, so if this chromate treatment can not be carried out, these performances are significantly reduced. Therefore, it has been required to form a rustproof layer having good corrosion resistance and coating adhesion without performing chromate treatment.

In Patent Document 1, an ethylene-unsaturated carboxylic acid copolymer resin particle (A) having an average particle diameter of 20 to 100 nm and containing a silanol group and / or an alkoxysilyl group, and having an average particle diameter of 5 to 50 nm A coated steel sheet is described, which is a film in which a certain silicon oxide particle (B) and an organic titanium compound (C) are combined, and the film amount is 0.5 to 3 g / m ² . However, in the above-mentioned film, although adhesion to a substrate and press oil resistance are improved, a further improvement in tape peel resistance is required.

Patent Document 2 discloses a metal in which an organic resin, a silane coupling agent, and a solid wetting agent are contained in an aqueous solution of lithium silicate having an SiO ₂ / Li ₂ O ratio (molar ratio) of 18 to 33, as a metal A surface-treated metal plate is described, which is characterized by being applied to a plate surface and then dried. However, the above-mentioned metal plate has a problem that alkali resistance is inferior.

  Patent Document 3 describes a surface-treated metal plate in which a surface-treated film is formed on a metal plate or a plated metal plate, and the surface-treated film has a Si / Li ratio of 36 to 66 (molar ratio). A surface-treated metal plate is described which is characterized in that it has the following structure and is substantially free of Cr. However, the above-described metal plate has a problem that the tape peel resistance is inferior.

  Patent Document 4 discloses that in an aqueous medium, a lithium silicate having a Si / Li molar ratio in the range of 1 to 4 and a silane coupling agent in an amount of 5 to 50 parts by mass with respect to 100 parts by mass of the lithium silicate, Characterized by containing 0.2 to 10 parts by mass (as vanadium metal) of a vanadium compound, 0.2 to 10 parts by mass (as titanium metal) a titanium compound, and 0.01 to 10 parts by mass of a wax The surface treatment liquid for zinc-based plated metal materials is described. However, the above-mentioned surface treatment liquid for zinc-based plated metal materials does not have sufficient alkali resistance.

Patent No. 4922295 gazette Unexamined-Japanese-Patent No. 11-58599 JP 2000-45078 A Unexamined-Japanese-Patent No. 2010-37584

  In the present invention, in view of the above-mentioned present conditions, metal surface treatment for galvanized steel materials having improved press oil resistance, substrate adhesion, tape peel resistance, paint adhesion, processed part corrosion resistance, alkali resistance, and abrasion resistance. It is an object of the present invention to provide an agent, a coating method using the metal surface treatment agent, and a coated steel material.

  Here, the tape peel resistance is covered when the tape is peeled off, even if it is fixed with a highly adhesive tape when the coil or processed product of the steel material is transported by sea freight and exposed to high temperature and high humidity conditions. The film shows that the film does not peel, and the abrasion resistance indicates the resistance to abrasion damage that may occur due to abrasion when transporting the coil of steel material and the processed product.

The inventors of the present invention conducted intensive studies and found that specific organic resin particles (A), silicon oxide particles (B), lithium silicates (C), organic titanium compounds (D), and epoxy group-containing compounds (E). It is a metal surface treatment agent for galvanized steel materials containing, The SiO ₂ conversion number-of-moles of the total amount of the silicon contained in the said silicon oxide particle (B) and the said lithium silicate (C) is the said lithium silicate (C 40 to 70 times the number of moles of lithium element contained in (Li ₂ O), and the mass of the lithium silicate (C) with respect to the mass of the titanium element contained in the organic titanium compound (D) The metal surface treatment agent for galvanized steel materials having a ratio of 0.2 to 200 has excellent press oil resistance, adhesion to substrates, tape peelability, coating adhesion, corrosion resistance to processed parts, alkali resistance, and abrasion resistance. sex It found that expression, thereby completing the present invention.

That is, the present invention provides the following [1] to [7].
[1] Metal surface treatment agent for galvanized steel containing organic resin particles (A), silicon oxide particles (B), lithium silicate (C), organic titanium compound (D), and epoxy group-containing compound (E) The organic resin particles (A) are resin particles in which a base resin is modified with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and a silanol group and And / or a resin particle having an alkoxysilyl group, and the total number of silicon elements contained in the silicon oxide particles (B) and the lithium silicate (C) in terms of SiO ₂ conversion mole number is the lithium silicate (C ) Is 40 to 70 times the molar number of lithium element contained in Li ₂ O conversion, and the solid content mass of the organic resin particles (A) to the total solid mass of the metal surface treatment agent Is 20 70% by mass, 10 to 50% by mass of the silicon oxide particles (B), 1 to 10% by mass of the lithium silicate (C), and the organic titanium compound (D) in terms of titanium element It is 0.05-5 mass%, The said epoxy group containing compound (E) is 0.2-10 mass%, The said lithium silicate (The mass of the titanium element with respect to the mass of the titanium element contained in the said organic titanium compound (D) ( A metal surface treatment agent for galvanized steel, wherein the mass ratio of C) is 0.2 to 200.
[2] The ratio of the mass of the total amount of the silane coupling agent (A-1) to the sum of the mass of the titanium element contained in the organic titanium compound (D) and the mass of lithium silicate (C) is 0 The metal surface treatment agent for galvanized steel materials according to the above [1], which is 01 to 13.
[3] The metal surface for galvanized steel according to the above [1] or [2], containing 0.1 to 10% by mass of the niobium compound (F) based on the total solid mass of the metal surface treatment agent Processing agent.
[4] Any of the above [1] to [3], containing 0.1 to 10% by mass of the phosphoric acid compound (G) with respect to the total mass of the solid content of the metal surface treatment agent, as phosphorus element conversion Metal surface treatment agent for galvanized steel according to the description.
[5] The organic resin particles (A) are obtained by blending and reacting the silane coupling agent (A-1) in a proportion of 1 to 20% by mass based on the solid content mass of the base resin. The metal surface treatment agent for galvanized steel materials according to any one of the above [1] to [4].
[6] Organic resin particles (A) can be obtained by blending and reacting the multifunctional epoxy group-containing compound (A-2) in a proportion of 1 to 20% by mass with respect to the solid content mass of the base resin The metal surface treatment agent for galvanized steel products according to any of the above [1] to [5].
[7] The total SiO ₂ conversion mole number of the total amount of silicon elements contained in the silicon oxide particles (B) and the lithium silicate (C) is Li of lithium elements contained in the lithium silicate (C) The metal surface treatment agent for galvanized steel products according to any one of the above [1] to [6], which is 50 to 65 times the ₂ O conversion mole number.
[8] A galvanized steel according to any one of the above [1] to [7], which is coated on the surface of the galvanized steel to form a film. Coating method.
[9] A coated steel material obtained by the method for coating galvanized steel according to the above [8].

  According to the present invention, a metal surface treatment agent for galvanized steel having improved press oil resistance, substrate adhesion, tape peelability, paint adhesion, processed part corrosion resistance, alkali resistance and abrasion resistance, It is possible to provide a coating method and a coated steel material using a metal surface treatment agent.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[Metal surface treatment agent for galvanized steel]
The metal surface treatment agent for galvanized steel of the present invention comprises organic resin particles (A), silicon oxide particles (B), lithium silicate (C), organic titanium compound (D), and epoxy group-containing compound (E) A metal surface treatment agent for galvanized steel, wherein the organic resin particles (A) are modified with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2) It is a resin particle, It is a resin particle which has a silanol group and / or an alkoxy silyl group, The SiO ₂ conversion number-of-moles of the total amount of the silicon element contained in the said silicon oxide particle (B) and said lithium silicate (C) There are 40 to 70 times the Li 2 _O in terms of the number of moles of lithium element contained in the lithium silicate (C), the total of the solid mass of the metal surface treatment agent, the organic resin The solid content mass of the child (A) is 20 to 70% by mass, the silicon oxide particles (B) are 10 to 50% by mass, and the lithium silicate (C) is 1 to 10% by mass, The organic titanium compound (D) is 0.05 to 5% by mass in terms of titanium element, the epoxy group-containing compound (E) is 0.2 to 10% by mass, and is contained in the organic titanium compound (D) It is a metal surface treatment agent for galvanized steel materials in which the ratio of the mass of the lithium silicate (C) to the mass of the titanium element is 0.2 to 200.
Thus, the metal surface treatment agent for galvanized steel according to the present invention can be used in any of press oil resistance, substrate adhesion, tape peel resistance, paint adhesion, processed part corrosion resistance, alkali resistance, and abrasion resistance. It has excellent performance.

<Organic resin particles (A)>
The organic resin particles (A) used in the present invention are resin particles in which the base resin is modified with the silane coupling agent (A-1) and the polyfunctional epoxy group-containing compound (A-2), and Or resin particles having an alkoxysilyl group.
The base resin is not particularly limited. For example, a copolymer resin of ethylene and an unsaturated carboxylic acid such as acrylic acid, methacrylic acid or maleic anhydride (for example, ethylene-methacrylic acid copolymer) Water-dispersed acrylic resin neutralized with alkali metal hydroxides such as sodium and potassium hydroxide, ammonia water and organic amines and dispersed in water, isocyanate group-containing compound and polyol, low molecular weight polyol, and active hydrogen group A water dispersible polyurethane resin etc. which made the polyurethane prepolymer react by making it react with the compound containing a hydrophilic group, and then neutralized the above-mentioned hydrophilic group by the neutralizing agent are mentioned.
As organic resin particles (A), silanol groups and / or alkoxy obtained by reacting the dispersion resin liquid with a silane coupling agent (A-1) described later and a polyfunctional epoxy group-containing compound (A-2). Examples thereof include acrylic resin particles having a silyl group, and polyurethane resin particles having a silanol group and / or an alkoxysilyl group. In particular, a silane coupling agent (A-1) described later and a multifunctional epoxy group-containing compound (A-2) or the like are caused to act on the aqueous dispersion resin solution of the ethylene-methacrylic acid copolymer resin neutralized with a base. The acrylic resin particles thus obtained are preferable in that they can be micronized and can form a high-performance film.

For example, when the ethylene-methacrylic acid copolymer resin is used as the base resin, the ethylene content is 90 to 70% by mass, and the methacrylic acid content is 10 to 30% by mass. preferable.
Moreover, although it may contain other monomers as needed, it is preferable that the usage-amount is 10 mass% or less. When using the said ethylene- methacrylic acid copolymer resin, it can manufacture by well-known methods, such as superposition | polymerization by the manufacturing apparatus of high-pressure-process low-density polyethylene, for example.
As a compounding quantity, it is preferable to make base resin react by 80 mass% or more with respect to solid content mass of the said organic resin particle (A). More preferably, it is in the range of 90% by mass or more.

  The organic resin particles (A) have a silanol group and / or an alkoxysilyl group. By having the above functional group, a reaction with the silicon oxide particles (B) and the organic titanium compound (D) can be caused to form a film, and adhesion to a substrate, oil resistance against pressing, etc. can be improved. . The alkoxysilyl group in the above alkoxysilyl group is not particularly limited, and examples thereof include trimethoxysilyl group, dimethoxysilyl group, methoxysilyl group, triethoxysilyl group, diethoxysilyl group, and ethoxysilyl group. The said functional group can be obtained by making the silane coupling agent (A-1) etc. which are mentioned later react with the water dispersion liquid of the said base resin.

(Silane coupling agent (A-1))
The silane coupling agent (A-1) used in the organic resin particles (A) is, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxy Epoxy group-containing silane compounds such as silane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ -(2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- Amino group-containing silane compounds such as minopropyl ethoxysilane, N- [2- (vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltri Mercapto-containing silane compounds such as methoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyl Methyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, etc. It is preferable that it is a containing silane compound. These may be used alone or in combination of two or more.
As a compounding quantity, it is preferable to mix and react a silane coupling agent (A-1) in the ratio used as 1 to 20 mass% with respect to 100 mass% of solid content of the said base resin. More preferably, it is in the range of 1 to 10% by mass. When the content is 1% by mass or more, the alkali resistance, solvent resistance, coating adhesion, etc. of the film formed on the surface of the steel material are good, and when it is 20% by mass or less, the hydrophilicity of the film becomes appropriate and the corrosion resistance And the liquid stability of the metal surface treatment agent used to form the film may be good.

(Multifunctional epoxy group-containing compound (A-2))
Sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, propylene glycol diglycidyl as the polyfunctional epoxy group-containing compound (A-2) used for the organic resin particles (A) Ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, bisphenol A glycidyl ether, hydrogenated bisphenol A diglycidyl ether, etc. can be mentioned. These may be used alone or in combination of two or more. When a polyfunctional epoxy group containing compound (A-2) is used, since affinity with an organic resin will increase, when a top coat is apply | coated to the said film, it may be advantageous to coating-film adhesiveness improvement.
Here, a polyfunctional epoxy group containing compound (A-2) does not contain an epoxy group containing silane compound.
As a compounding quantity, it is preferable to make 1 to 20 mass% of polyfunctional epoxy group containing compounds (A-2) react with respect to 100 mass% of solid content of the said base resin. More preferably, it is in the range of 1 to 10% by mass. When the content is 1% by mass or more, the alkali resistance, solvent resistance, coating adhesion, etc. of the film formed on the surface of the steel material are good, and when it is 20% by mass or less, the hydrophilicity of the film becomes appropriate and the corrosion resistance And the liquid stability of the metal surface treatment agent used to form the film may be good.

  The resin particles of the organic resin particles (A) preferably have an average particle diameter of 20 to 100 nm. Here, the average particle diameter can be measured by a particle diameter measuring apparatus by a dynamic light scattering method, for example, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.). The value of the average particle size is a cumulant average particle size obtained by diluting an aqueous dispersion of resin particles (A) with ion-exchanged water to a concentration suitable for measurement by the above apparatus and measuring at a liquid temperature of 25 ° C. is there. When the average particle diameter by the above method is 20 nm or more, the viscosity and the hydrophilicity become appropriate, and the workability, the corrosion resistance and the like become good. When the average particle size is 100 nm or less, the adhesion to a substrate, the press oil resistance, etc. become good in terms of the film performance.

The said organic resin particle (A) is contained by 20-70 mass% with respect to the sum total of solid content mass of the said metal surface treatment agent. If the amount is less than 20% by mass, sufficient coating film performance, in particular, corrosion resistance at the machined portion can not be obtained. Moreover, it is 70 mass% or less from a viewpoint of adjusting balance with content of another component and exhibiting the effect of this invention favorably. From the same viewpoint, the content of the organic resin particles (A) is preferably 30 to 65% by mass, more preferably 40 to 60% by mass, based on the total mass of the solid content of the metal surface treatment agent. .
In addition, content of the said organic resin particle (A) can also be calculated from the compounding quantity at the time of mix | blending each raw material.

<Silicon oxide particles (B)>
The number average particle diameter of primary particles of the silicon oxide particles (B) used in the present invention is preferably 5 to 50 nm, more preferably 5 to 20 nm, and appropriately selected from colloidal silica, fumed silica, etc. be able to. The number average particle diameter of primary particles of the silicon oxide particles (B) can be determined by electron microscopic observation. Specific examples of the silicon oxide particles (B) include Snowtex N, Snowtex C (made by Nissan Chemical Industries, Ltd.), Adareite AT-20N, AT-20A (made by ADEKA), Cataloid S-20L, Cataloid SA (JGC Corporation) Catalysts, Inc. make) etc. are mentioned. These may be used alone or in combination of two or more.
The silicon oxide particles (B) are contained in an amount of 10 to 50% by mass with respect to the total solid mass of the metal surface treatment agent. If it is less than 10% by mass, sufficient coating film performance, in particular, substrate adhesion and tape peel resistance can not be obtained. Moreover, it is 50 mass% or less from a viewpoint of adjusting balance with content of another component and exhibiting the effect of this invention favorably. From the same viewpoint, the content of the silicon oxide particles (B) is preferably 15 to 45% by mass, more preferably 20 to 40% by mass, based on the total mass of the solid content of the metal surface treatment agent. .
In addition, content of a silicon oxide particle (B) can also be calculated from the compounding quantity at the time of mix | blending each raw material

<Lithium silicate (C)>
Lithium silicate (C) used in the present invention is a salt composed of lithium oxide and silicon dioxide, and is represented by the general formula Li ₂ O · nSiO ₂ . Lithium orthosilicate (Li ₄ SiO ₄ (Li ₂ O.0.5SiO ₂ : n = 0.5)), lithium metasilicate (Li ₂ SiO) according to the value of n representing the molar ratio of lithium oxide to silicon dioxide _{3 (Li 2 O · SiO 2} : n = 1)), ortho disilicate six lithium _{(Li 6 Si 2 O 7 (} Li 2 O · 2 / 3SiO 2: n = 2/3)), Li 4 Si 7 O ₁₆ (Li ₂ O.3.5SiO ₂ : n = 3.5), Li ₄ Si ₉ O ₂₀ (Li ₂ O.4.5SiO ₂ : n = 4.5), Li ₄ Si ₁₅ O ₃₂ (Li ₂ O · 7.5 SiO ₂ : n = 7.5) and the like. Also, lithium silicate (C) may be, for example, a hydrate thereof.
Furthermore, lithium silicate (C) can also be used, for example, as an aqueous solution of lithium silicate, and in such a case, the solid content concentration of the aqueous solution is, for example, 1 to 50% by mass, preferably 2 to 40% by mass It is. The water solubility of lithium silicate (C) differs depending on the molar ratio n of lithium oxide and silicon dioxide. For example, lithium silicate having n of 2 to 5 is soluble in water. , N is 6 to 10, and lithium silicate is insoluble in water.
Moreover, as such lithium silicate (C), for example, lithium silicate 35 (lithium silicate aqueous solution, SiO ₂ / Li ₂ O (molar ratio) = 3.5), lithium silicate 45 (lithium silicate aqueous solution, SiO ₂ / Li ₂ O (molar ratio) = 4.5), lithium silicate 75 (lithium silicate aqueous solution, SiO ₂ / Li ₂ O (molar ratio) = 7.5) (all manufactured by Nissan Chemical Industries, Ltd.) Etc. These may be used alone or in combination of two or more.
It is considered that a film excellent in tape adhesion resistance is formed when lithium silicate (C) forms a pseudo-crosslink by ionic crosslinking with the silicon oxide particles (B).
Lithium silicate (C) is contained in an amount of 1 to 10% by mass based on the total mass of the solid content of the metal surface treatment agent. If it is less than 1% by mass, the tape peel resistance will be poor. Moreover, it is 10 mass% or less from a viewpoint of adjusting balance with content of another component and exhibiting the effect of this invention favorably. From the same viewpoint, the content of the lithium silicate (C) is preferably 1 to 7% by mass, more preferably 1 to 5% by mass, based on the total mass of the solid content of the metal surface treatment agent. .
In addition, content of lithium silicate (C) can also be calculated from the compounding quantity at the time of mix | blending each raw material.

The SiO ₂ conversion mole number of the total amount of silicon elements contained in the silicon oxide particles (B) and the lithium silicate (C) corresponds to the Li ₂ O conversion of the lithium element contained in the lithium silicate (C) The molar ratio is 40 to 70 times (hereinafter, the molar ratio of SiO _{2 to} Li ₂ O is also simply 40 to 70). When the molar ratio of SiO _{2 to} Li ₂ O is less than 40, sufficient coating film performance can not be obtained, and particularly, the alkali resistance is lowered, and when it is more than 70, the tape peeling resistance is inferior. From the same viewpoint, the SiO ₂ molar ratio to the Li ₂ O is preferably 50 to 65, more preferably 50 to 60.

As described above, in the metal surface treatment agent for galvanized steel according to the present invention, the ratio of the mass of lithium silicate (C) to the mass of titanium element contained in the organic titanium compound (D) is 0.2 It is ~ 200. When the mass ratio is less than 0.2, press oil resistance and tape peel resistance deteriorate, and when the mass ratio exceeds 200, alkaline degreasing deteriorates. From the same viewpoint, the ratio of the mass of the lithium silicate (C) to the mass of the titanium element contained in the organic titanium compound (D) is preferably 0.5 to 17, and more preferably 1.5 to 17 It is.
In addition, the metal surface treatment agent for galvanized steel of the present invention is the silane coupling agent (based on the sum of the mass of titanium element contained in the organic titanium compound (D) and the mass of lithium silicate (C)) The mass ratio of A-1) is preferably 0.01 to 13. When the mass ratio is in the range of 0.01 to 13, the tape peel resistance and the alkali resistance are improved, and the press oil resistance and the corrosion resistance at the processed portion are also improved. From the same viewpoint, the ratio of the mass of the silane coupling agent (A-1) to the sum of the mass of the titanium element contained in the organic titanium compound (D) and the mass of lithium silicate (C) is Preferably it is 0.1-13, More preferably, it is 0.35-0.65.

<Organic titanium compound (D)>
Specific examples used as the organic titanium compound (D) used in the present invention include dipropoxybis (triethanolaminato) titanium, dipropoxybis (diethanolaminato) titanium, dibutoxybis (triethanolaminato) titanium, dibutoxybis (diethanolamito) Nato) titanium, dipropoxy bis (acetylacetonato) titanium, dibutoxy bis (acetyl acetonato) titanium, dihydroxy bis (lactato) titanium monoammonium salt, dihydroxy bis (lactato) titanium diammonium salt, propanedioxy titanium bis (ethyl acetoacetate) And oxotitanium bis (monoammonium oxalate), isopropyl tri (N-amidoethyl aminoethyl) titanate and the like. These may be independent or may use 2 or more types together.
The organic titanium compound (D) is contained in an amount of 0.05 to 5% by mass with respect to the total mass of the solid content of the metal surface treatment agent as titanium element conversion. If it is less than 0.05% by mass, sufficient coating film performance can not be obtained. Moreover, it is 5 mass% or less from a viewpoint of adjusting balance with content of another component and exhibiting the effect of this invention favorably. From the same viewpoint, the content of the organic titanium compound (D) is more preferably 0.1 to 2% by mass, still more preferably, based on the total mass of the solid content of the metal surface treatment agent, in terms of titanium element Is 0.3 to 1% by mass.
In addition, content of an organic titanium compound (D) can also be calculated from the compounding quantity at the time of mix | blending each raw material.

<Epoxy group-containing compound (E)>
The epoxy group-containing compound (E) used in the present invention is not particularly limited, but is a multifunctional epoxy resin, and from the viewpoint of being able to reduce the amount of raw materials used, more multifunctional is preferable, preferably trifunctional or more, more preferably Is four or more functional. Moreover, it is preferable that it is a 3-5 functional, for example from a viewpoint of adjusting the viscosity change by reaction with organic resin particle (A), and the handling property of the obtained metal processing agent. As a specific example, the above-mentioned polyfunctional epoxy group containing compound (A-2) can be used as an epoxy group containing compound, for example.
The epoxy group-containing compound (E) crosslinks with the organic resin particles (A) at the time of film formation to form a highly crosslinked film, thereby particularly improving the press resistance.
The epoxy group-containing compound (E) is contained in an amount of 0.2 to 10% by mass with respect to the total solid mass of the metal surface treatment agent. If the amount is less than 0.2% by mass, sufficient coating performance, particularly sufficient press resistance can not be obtained. Moreover, it is 10 mass% or less from a viewpoint of adjusting balance with content of another component and exhibiting the effect of this invention favorably. From the same viewpoint, the content of the epoxy group-containing compound (E) is preferably 1 to 8% by mass, more preferably 2 to 7% by mass, based on the total mass of the solid content of the metal surface treatment agent. is there.
In addition, content of an epoxy group containing compound (E) can also be calculated from the compounding quantity at the time of mix | blending each raw material.

<Niobium compound (F)>
It is preferable that the metal surface treatment agent for galvanized steel products of the present invention further contains a niobium compound (F) in addition to the above (A) to (E).
The niobium compound (F) is preferably contained in an amount of 0.1 to 10% by mass based on the total solid mass of the metal surface treatment agent. When it is in the range of 0.1 to 10% by mass, the corrosion resistance at the machined part is excellent. From the same viewpoint, the content of the niobium compound (F) is more preferably 0.2 to 5% by mass, still more preferably 0.5 to 2 based on the total mass of the solid content of the metal surface treatment agent. It is mass%.

  The niobium compound (F) is not particularly limited, and conventionally known niobium-containing compounds can be used, and examples thereof include niobium oxide, niobic acid and salts thereof, fluoroniobate salt, fluorooxoniobate salt and the like. Can. Among them, niobium oxide is preferable from the viewpoint of improving the corrosion resistance.

  The niobium oxide is preferably niobium oxide particles. Thereby, a film in which niobium oxide particles are complexed can be formed, and the corrosion resistance can be further improved.

  The niobium oxide particles refer to particles in which an oxide of niobium is dispersed in water in the form of fine particles. For example, niobium oxide is not strictly formed, and it is in an amorphous state in an intermediate state of niobium hydroxide and niobium oxide. It may be the

  Niobium oxide particles produced by a known method can be used as the niobium oxide particles added to the metal surface treatment agent used for forming a film. The niobium oxide particles are not particularly limited, and, for example, those produced by known methods described in JP-A-6-321543, JP-A-8-143314, JP-A-8-325018, etc. Can be mentioned. In addition, niobium oxide sol and niobium oxide slurry marketed by Taki Chemical Co., Ltd. can also be used.

  The average particle diameter of the niobium oxide particles is preferably 2 nm to 10 μm, and more preferably 2 nm to 1 μm. The smaller the average particle diameter, the more stable and dense the film comprising niobium oxide is formed, so that the rustproofness can be stably imparted to the object to be treated, which is more preferable. The average particle size of the niobium oxide particles is determined as a volume average particle size which is a particle size at which the volume accumulation is 50% using a laser light diffraction / scattering type microtrack HRA particle size distribution analyzer (manufactured by HONEYWELL) or the like. Can.

<Phosphoric acid compound (G)>
The metal surface treatment agent for galvanized steel according to the present invention preferably further contains a phosphoric acid compound (G) in addition to (A) to (E) or (A) to (F). Examples of phosphoric acid compounds (G) include phosphoric acids such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, triphosphoric acid, tetraphosphoric acid, etc., triammonium phosphate, diammonium hydrogen phosphate, trisodium phosphate, dibasic hydrogen phosphate Examples include phosphates such as sodium. These may be used alone or in combination of two or more.
When the phosphate compound (G) is used, phosphate ions can form a phosphate layer on the surface of the metal substrate to passivate and improve the corrosion resistance.
The phosphoric acid compound (G) is preferably contained in an amount of 0.1 to 10% by mass, based on the total mass of the solid content of the metal surface treatment agent, in terms of phosphorus element. When it exists in the range of 0.1-10 mass%, it is excellent in corrosion resistance of a process part. From the same viewpoint, the content of the phosphoric acid compound (G) is more preferably 0.2 to 5% by mass, still more preferably, based on the total mass of the solid content of the metal surface treatment agent, in terms of phosphorus element. Is 0.5 to 2% by mass.
In addition, content of a phosphoric acid compound (G) can also be calculated from the compounding quantity at the time of mix | blending each raw material.

  By using the phosphoric acid compound (G) and the niobium compound (F) in combination, it is possible to form a film which is excellent in corrosion resistance particularly in the processed part. The ratio of the phosphorus equivalent mass of the phosphoric acid compound (G) to the mass of the niobium compound (F) is preferably 0.01 to 100, more preferably 0.03 to 10, still more preferably 0.03 to 4

<Water>
The metal surface treatment agent for galvanized steel of the present invention further contains water in addition to the above (A) to (E), the above (A) to (F) or the above (A) to (G). May be

<Other ingredients>
The metal surface treatment agent for galvanized steel materials of the present invention may contain other components in addition to the above (A) to (G) and water. For example, waxes, lubricants and pigments may be blended. As the wax, it is possible to use conventionally known waxes such as paraffin, microcrystalline, hydrocarbon based waxes such as polyolefin and derivatives thereof. As said derivative, carboxylated polyolefin, chlorinated polyolefin, etc. can be mentioned. As the lubricant, for example, conventionally known lubricants such as fluorine type, hydrocarbon type, fatty acid amide type, ester type, alcohol type, metal soap type and inorganic type can be used. Examples of the pigment include titanium oxide (TiO ₂ ), zinc oxide (ZnO), calcium carbonate (CaCO ₃ ), barium sulfate (BaSO ₄ ), alumina (Al ₂ O ₃ ), kaolin clay, carbon black, iron oxide Inorganic pigments such as (Fe ₂ O ₃ , Fe ₃ O ₄ ), and various color pigments such as organic pigments can be used. In addition, as a rust inhibitor, for example, a thiocarbonyl compound or guanidine compound described in Japanese Patent No. 492295 can be used.

(Method of producing metal surface treatment agent for galvanized steel)
The metal surface treatment agent for galvanized steel of the present invention comprises the silicon oxide particles (B), the lithium silicate (C), and the organic material in an aqueous dispersion in which the resin particles of the organic resin particles (A) are dispersed. A titanium compound (D) and the epoxy group-containing compound (E) are blended to prepare the metal surface treatment agent, and further, if necessary, the niobium compound (F) the phosphoric acid compound (G), water, It can manufacture by mix | blending 1 or more types chosen from another component.

[Coating method of galvanized steel]
The coating method for galvanized steel according to the present invention is characterized in that the metal surface treatment agent for galvanized steel according to the present invention is applied to the surface of the galvanized steel to form a film. Thereby, the coating method of the galvanized steel according to the present invention is excellent in any of press oil resistance, base material adhesion, tape peel resistance, paint adhesion, processed part corrosion resistance, alkali resistance, and abrasion resistance. Have.

The film is in a state in which the organic resin particles (A), silicon oxide particles (B), organic titanium compound (D) and epoxy group-containing compound (E) are mutually bonded. That is, the functional group of the organic resin particle (A), the functional group of the silicon oxide particle (B) surface, the functional group of the organic titanium compound (D) and the epoxy group-containing compound (E) form a bond and form a complex It is.
Furthermore, it is considered that pseudo crosslinking is formed in the film by ionic crosslinking of the silicon oxide particles (B) and lithium silicate (C).

The bonding is mainly performed by the Si-OR group and / or the Si-OH group of the organic resin particle (A), the Si-OH group of the surface of the silicon oxide particle (B), and the Ti-OR 'group of the organic titanium compound (D) And / or a bond formed by the reaction of a Ti-OH group, which is considered to be a Si-O-Si bond, a Si-O-Ti-O-Si bond, or the like. These bonds provide the advantageous effect that the organic resin particles and the inorganic particles form chemically strong bonds. Further, by crosslinking the carboxylic acid group of the organic resin particle (A) and the epoxy group of the epoxy group-containing compound (E), a stronger film is formed, and the press oil resistance and the like are improved. it is conceivable that. Here, said R is a substituent derived from the above-mentioned silane coupling agent (A-1), and said R 'is a substituent derived from the above-mentioned organic titanium compound (D).
Furthermore, as described above, it is considered that a film excellent in tape adhesion resistance is formed by forming pseudo-crosslinking by silicon dioxide particles (B) and lithium silicate (C) by ionic crosslinking.
And, since the particle diameter of the organic resin particles (A) is within a specific range, the above-mentioned interparticle bonding is formed in high density in the above-mentioned film, so that it is chemically stable and fine. It becomes a coating with high homogeneity visually. For this reason, it is presumed that the metal surface treatment agent for galvanized steel of the present invention can obtain particularly remarkable effects.
In producing the metal surface treatment agent for coating the galvanized steel material, the addition order of the above-mentioned respective components is not particularly limited, but for example, the above-mentioned method of producing the metal surface treatment agent for galvanized steel material may be used it can.

  A solvent or a leveling agent may be used as the metal surface treatment agent for galvanized steel in order to form a more uniform and smooth film. The solvent and the leveling agent are not particularly limited as long as they are generally used in paints, and examples thereof include hydrophilic solvents such as alcohols, ketones, esters, and ethers, and leveling agents such as silicones. be able to.

The formation of the film by the metal surface treatment agent can be performed by applying the metal surface treatment agent to the surface of the steel material. For example, in order to coat a zinc-coated steel or an uncoated steel, the metal surface treatment agent is applied to a degreased object as required. The coating method is not particularly limited, and generally used roll coat, air spray, airless spray, immersion and the like can be appropriately adopted. In order to enhance the curability of the film, it is preferable to heat the substrate in advance, or to thermally dry the substrate after coating. The steel plate achieved temperature (PMT), which is an indicator of the heating temperature of the substrate, is preferably 20 to 250 ° C., more preferably 50 to 220 ° C. When the heating temperature is 50 ° C. or more, the evaporation rate of water is fast and sufficient film forming property can be obtained, so that the solvent resistance and the alkali resistance are improved. On the other hand, when the temperature is 250 ° C. or less, thermal decomposition of the resin hardly occurs, so that the solvent resistance and the alkali resistance can be improved, and the deterioration of the appearance due to yellowing can be suppressed.
In addition, the metal surface treatment agent for galvanized steel of the present invention has sufficiently excellent performance because the water is evaporated and dried even under low temperature conditions around room temperature (20 ° C.) A film can be formed.
The drying time in the case of heat drying after coating is preferably 1 second to 5 minutes.

[Coated steel material]
The coated steel material of the present invention is obtained by coating a steel material with the metal surface treatment agent for galvanized steel of the present invention. In addition, the metal surface treatment agent for galvanized steel according to the present invention is applied to the surface of the galvanized steel to form a film, which is obtained by the coating method of galvanized steel. Thereby, the coated steel material of the present invention has excellent performance in any of press oil resistance, substrate adhesion, tape peelability, paint adhesion, processed part corrosion resistance, alkali resistance, and abrasion resistance.

In the coated steel material, the coating amount of the coating is preferably 0.1 to 3 g / m ² , and more preferably 0.5 to 1.5 g / m ² . When the amount of the coating is 0.1 g / m ² or more, the corrosion resistance is improved. The fall of base-material adhesiveness can be suppressed as the said film amount is 3 g / m < ² > or less.

  Moreover, the coated steel material of this invention can also be used, apply | coating a top coat on the said film, forming a coating film, and using it. Examples of the top coat include paints made of acrylic resin, acrylic modified alkyd resin, epoxy resin, urethane resin, melamine resin, phthalic acid resin, amino resin, polyester resin, vinyl chloride resin and the like.

  The film thickness of the coating film of the top coat is appropriately determined according to the application of the rustproof metal product, the type of top coat to be used, and the like, and is not particularly limited. Usually, it is 5 to 300 μm, more preferably 10 to 200 μm. The formation of the coating film of the top coating can be performed by applying the top coating on the film formed by the metal surface treatment agent for the galvanized steel material, heating, drying, and curing. The drying temperature and time are appropriately adjusted according to the type of top coating to be applied, the film thickness of the coating film, etc. Generally, the drying temperature is preferably 50 to 250 ° C., and the drying time is , 5 minutes to 1 hour is preferred. As a coating method of top coat, it can carry out by a publicly known method according to a paint form.

  The steel materials used in the present invention include, for example, galvanized steel, zinc-nickel plated steel, zinc-iron plated steel, zinc-chromium plated steel, zinc-aluminum plated steel, zinc-titanium plated steel, zinc-magnesium plated steel Zinc-plated steel such as zinc-manganese plated steel, zinc-aluminum-magnesium plated steel, zinc-aluminum-magnesium-silicon plated steel, etc. Furthermore, cobalt, molybdenum, or the like as small amounts of dissimilar metal elements or impurities in these plated layers. Containing tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic, etc., dispersed inorganic substances such as silica, alumina, titania, etc. Be Furthermore, it is applicable also to the above-mentioned plating and other types of plating, for example, multi-layer plating combined with iron plating, iron-phosphorus plating, nickel plating, cobalt plating and the like. Furthermore, it is applicable also to aluminum or aluminum system alloy plating. The plating method is not particularly limited, and any known method such as electroplating, hot-dip plating, vapor deposition plating, dispersion plating, vacuum plating may be used.

  EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to the following examples. In the following description, unless otherwise specified, all% indications of concentration represent% by mass.

<Production Example 1>
(Production of Resin Particles (a-1))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. In this aqueous dispersion resin solution, further, hydrogenated bisphenol A diglycidyl ether (product name: SR-HBA, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) 0.69% and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (product Name: KBM-303 (Shin-Etsu Chemical Co., Ltd.) 1.15% added and reacted at 85 ° C for 2 hours to obtain resin particles having 24% solid content, silanol group and / or methoxysilyl group (a An aqueous dispersion of -1) was obtained. The average particle diameter of the resin particles (a-1) was 70 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 2>
(Production of Resin Particles (a-2))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of hydrogenated bisphenol A diglycidyl ether and 0.29% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are added to this aqueous dispersion resin solution, and the mixture is reacted at 85 ° C. for 2 hours. Thus, an aqueous dispersion of resin particles (a-2) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained. The average particle diameter of the resin particles (a-2) was 70 nm, which was measured by a particle diameter measurement apparatus using dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 3>
(Production of Resin Particle (a-3))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of hydrogenated bisphenol A diglycidyl ether and 5.75% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are added to this aqueous dispersion resin solution, and reacted at 85 ° C. for 2 hours. Thus, an aqueous dispersion of resin particles (a-3) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained. The average particle diameter of the resin particles (a-3) was 70 nm, which was measured by a particle diameter measurement apparatus using dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

Production Example 4
(Production of Resin Particles (a-4))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. 0.23% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are further added to this aqueous dispersion resin solution, and reacted at 85 ° C. for 2 hours. Thus, an aqueous dispersion of resin particles (a-4) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained. The average particle diameter of the resin particles (a-4) was 70 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 5>
(Production of Resin Particles (a-5))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 4.6% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are added to this aqueous dispersion resin solution, and reacted at 85 ° C. for 2 hours. Thus, an aqueous dispersion of resin particles (a-5) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained. The average particle diameter of the resin particles (a-5) was 70 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering method, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 6>
(Production of Resin Particles (a-6))
In a reaction vessel, water-based urethane resin (product name: Adekabon Titer HUX-320, manufactured by Adeka) (solid content 30%), hydrogenated bisphenol A diglycidyl ether 0.90% and 2- (3,4-epoxycyclohexyl ) An aqueous dispersion of resin particles (a-6) having a silanol group and / or a methoxysilyl group at a solid content of 24% by adding 1.50% of ethyltrimethoxysilane and reacting at 85 ° C. for 2 hours I got The average particle diameter of the resin particles (a-6) was 70 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering method, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

Production Example 7
(Production of Resin Particles (a-7))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of hydrogenated bisphenol A diglycidyl ether and 1.15% of γ-glycidoxypropyltrimethoxysilane (product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) are added to this aqueous dispersion resin solution. The reaction was carried out at 85 ° C. for 2 hours to obtain an aqueous dispersion of resin particles (a-7) having a silanol group and / or a methoxysilyl group at a solid content of 24%. The average particle diameter of the resin particles (a-7) was 70 nm, which was measured by a particle diameter measurement apparatus using dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 8>
(Production of Resin Particle (a-8))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% of sodium hydroxide and deionized water with respect to the resin in a reaction vessel, 95 ° C. The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of sorbitol polyglycidyl ether (product name: Denacol EX-614B, manufactured by Nagase ChemteX Corp.) and 0.65% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane were added to this aqueous dispersion resin solution. The reaction mixture was reacted at 85.degree. C. for 2 hours to obtain an aqueous dispersion of resin particles (a-8) having a silanol group and / or a methoxysilyl group at a solid content of 24%. The average particle diameter of the resin particles (a-8) was 70 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

<Production Example 9>
(Production of resin particles (b))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%) to the reaction vessel, add 4.6% of sodium hydroxide and deionized water to the resin, 95 ° C The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane are added to this water-dispersed resin solution and reacted at 85 ° C. for 2 hours. Thus, an aqueous dispersion of resin particles (b) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained. The average particle diameter of the resin particles (b) was 100 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering method, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

Production Example 10
(Production of resin particles (c))
Add ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%) to the reaction vessel, add 4.6% of sodium hydroxide and deionized water to the resin, 95 ° C The mixture was stirred for 6 hours to obtain an aqueous dispersion resin solution having a solid content of 23%. Further, 0.69% of hydrogenated bisphenol A diglycidyl ether is added to this aqueous dispersion resin solution, and the mixture is reacted at 85 ° C. for 2 hours to obtain an aqueous dispersion of resin particles (c) having a solid content of 24%. The In Production Example 10, no silane coupling agent is added. The average particle diameter of the resin particles (c) was 110 nm, which was measured by a particle diameter measurement apparatus by dynamic light scattering method, FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).

  The resin particles obtained in Production Examples 1 to 10 are shown in Table 1 below.

In Examples 1 to 32 and Comparative Examples 1 to 23 described later, the following raw materials and materials were used, and water was used as a solvent to prepare a metal surface treatment agent.
Silicon oxide particles; product name AT-20A, manufactured by ADEKA, average particle size 12 nm
Product name Lithium silicate 35, manufactured by Nippon Chemical Industry Co., Ltd. Organic titanium compound; Product name T-50, Dipropoxy bis (acetylacetonato) titanium manufactured by Nippon Soda Co., Ltd. Epoxy group-containing compound; Product name SR-HBA, Sakamoto Niobium compounds manufactured by Yakuhin Kogyo Co., Ltd .; product name: Viral Nb-G6000, manufactured by Takaki Chemical Co., Ltd., average particle diameter: 15 nm
Phosphoric acid compound; Material name: Trisodium phosphate (anhydride)
Other raw materials: Carbodiimide (product name: Carbodilight SV-02, manufactured by Nisshinbo Chemical Co., Ltd.), melamine resin (product name: Cymel 385, manufactured by Nippon Cytech Industries, Inc.) Polyethylene dispersion)

(Galvanized steel sheet)
Electrogalvanized steel sheet "NS Gin Coat (registered trademark)" manufactured by Nippon Steel & Sumikin Co., Ltd. (hereinafter referred to as EG), hot-dip galvanized steel sheet "NS Silver Zinc (registered trademark)" manufactured by Nippon Steel & Sumikin Co., Ltd. (Hereafter referred to as GI.), Zinc-aluminium-magnesium-silicon alloy plated steel sheet "Super-Dyma (registered trademark)" (hereinafter referred to as SD) manufactured by Nippon Steel & Sumikin Co., Ltd., manufactured by Nittetsu Sumikin Steel Co., Ltd. Zinc-Aluminum Alloy Plated Steel Plate "Galbarium Steel Plate (registered trademark)" (hereinafter referred to as "GL"), Zinc-Nickel Alloy Plated Steel Plate "NS Zincite (registered trademark)" manufactured by Nippon Steel & Sumikin Co., Ltd. (hereinafter referred to as ZL And a zinc-aluminum-magnesium alloy plated steel sheet “ZAM (registered trademark)” manufactured by Nisshin Steel Co., Ltd. were used as a base plate. The thickness of the original plate was 0.6 mm. The EG used had a plating adhesion amount of 20 g / m ² on one side. Moreover, GI, SD, GL, and ZAM used the thing whose plating adhesion amount is 60 g / m < ² > single-sided. The plating adhesion amount of ZL was 20 g / m ² on one side, and the amount of nickel in the plating layer was 12% by mass.

Example 1
(Preparation of metal surface treatment agent for galvanized steel)
Examples of the aqueous dispersion of the resin particles (a-1) include silicon oxide particles (B), lithium silicate (C), organic titanium compounds (D), epoxy group-containing compounds (E), niobium compounds (F) and phosphorus. The acid compound (G) was blended according to the formulation described in Table 2 to prepare a metal surface treatment agent for galvanized steel.
(Preparation of test plate)
Each galvanized steel sheet was degreased with a 2% aqueous solution of an alkaline degreaser (Surf Cleaner 155, manufactured by Nippon Paint Co., Ltd.) at 60 ° C. for 2 minutes, degreased, washed with water and dried in warm air. After cooling, the above metal surface treatment agent is applied to this degreased plate with a bar coater so that the dry film amount is 1 g / m ² , and the steel sheet reaching temperature using a hot air drying oven with an ambient temperature of 500 ° C. A test plate was produced by baking at a temperature of 150 ° C. and a temperature of 200 ° C. at a temperature of 150 ° C. using a hot air drying furnace so that the ultimate temperature (PMT) of the steel plate would be 50 ° C.

Examples 2 to 32 and Comparative Examples 1 to 23
Preparation of metal surface treatment agent for galvanized steel in the same manner as Example 1 using the combination of the metal surface treatment agent for galvanized steel described in Table 2 and Table 3, compounding condition, and preparation condition of test plate And the test plate was produced.

[Evaluation method]
The following evaluation was performed about the test plate of Examples 1-32 and Comparative Examples 1-23 produced as mentioned above. The evaluation results are shown in Tables 2 and 3.

<Press oil resistance>
After immersing the test plate in press oil (G6318SK, manufactured by Nippon Kogyo Oil Co., Ltd.) for 24 hours at room temperature, the test plate is washed with hexane, installed in a rubbing tester, and then using cotton impregnated with ethanol. The film condition after 10 cycles of rubbing with a load of 5 kgf / cm ² was evaluated according to the following evaluation criteria.
A: There is no rubbing mark on the rubbing surface B: A rubbing mark is slightly on the rubbing surface C: A white rubbing mark on the rubbing surface D: A part of the rubbing surface is peeled off

<Base material adhesion>
After extruding a test plate within 1 hour after painting with an Erichsen tester by 8 mm, Cellotape (registered trademark) (manufactured by Nichiban Co., Ltd.) was attached to the extrusion portion and forced peeling was performed. The film state after immersing the test plate after peeling in methyl violet stain | dye liquid for 30 minutes was evaluated by the following evaluation criteria.
A: Almost no peeling B: Peeling area less than 10% C: Peeling area 10% or more and less than 25% D: Peeling area 25% or more

<Tape peel resistance>
Filament tape (manufactured by Hitachi Maxell, Inc.) was attached to the test plate and left at 40 ° C. and humidity 80% for 2 weeks, and then the tape was forcibly peeled off. The film state was evaluated by the following evaluation criteria.
A: almost no peeling B: almost no peeling, but a tape mark remains C: less than 50% of peeled area D: 50% or more of peeled area

<Painting adhesion>
A melamine alkyd paint (trade name: Organa White, manufactured by Nippon Paint Co., Ltd.) was coated on the surface of the test plate with a bar coater so as to have a dry film thickness of 20 μm, and baked at 130 ° C. for 15 minutes to prepare a coated plate. Next, the coated plate is immersed in boiling water for 30 minutes, taken out and left for 24 hours, and the coated plate is extruded 7 mm with an Erichsen tester, and Sellotape (registered trademark) (manufactured by Nichiban Co., Ltd.) is affixed to the extrusion portion. The film state after forced peeling was evaluated by the following evaluation criteria.
A: Almost no peeling B: Peeling area less than 10% C: Peeling area 10% or more and less than 25% D: Peeling area 25% or more

<Processed part corrosion resistance>
The test plate was extruded by 7 mm with an Erichsen tester, the edge and back surface of the test plate were tape-sealed, and a salt spray test (SST) (JIS-Z-2371) was performed. The occurrence of white rust was observed after 72 hours and evaluated according to the following criteria.
A: No white rusting B: White rusting area less than 10% C: White rusting area 10% to less than 30% D: White rusting area 30% or more

<Alkali resistance>
The test plate is immersed in a 2% by mass aqueous solution (pH 12.5) of an alkaline degreaser (Surf Cleaner 155, manufactured by Nippon Paint Co., Ltd.) at 60 ° C. for 2 minutes with stirring, then the edge and back surface of the test piece are tape-sealed. The spray test (JIS-Z-2371) was performed. The occurrence of white rust was observed after 72 hours and evaluated according to the following criteria.
A: No white rusting B: White rusting area less than 10% C: White rusting area 10% to less than 30% D: White rusting area 30% or more

<Abrasion resistance>
A load of 10 g / cm ² was applied to the test plate through a corrugated paper, and an elliptical motion of 360 times / min was applied to generate abrasion (abrasion damage) on the sliding portion. The condition of the surface of the test plate after the test for 10 minutes was observed and evaluated according to the following criteria.
A: Almost no blackening B: The area less than 10% of the sliding part is blackened C: The area of 10% to 30% of the sliding part is blacked D: The area of 30% or more of the sliding part is black Turn

From the comparison between Examples 1 to 26 and Comparative Examples 1 to 19 as described in Tables 2 and 3 above, the metal surface treatment agent for galvanized steel of the present invention is resistant to press oil, adhesion to a substrate, The excellent effect was confirmed in any of the tape peelability, the paint adhesion, the corrosion resistance at the processed portion, the alkali resistance, and the abrasion resistance.
By using the metal surface treatment agent for galvanized steel according to the present invention, the coating method using the metal surface treatment agent, and the coated steel material, press oil resistance, substrate adhesion, tape peel resistance, coating adhesion, processing It was confirmed that excellent performance was exhibited in all of the corrosion resistance, the alkali resistance and the abrasion resistance.

  The metal surface treatment agent for galvanized steel according to the present invention, the coating method using the metal surface treatment agent, and the coated steel material can be suitably used for automobiles, home appliances, building material products and the like.

Claims (9)

Metal surface treatment agent for galvanized steel comprising organic resin particles (A), silicon oxide particles (B), lithium silicate (C), organic titanium compound (D), and polyfunctional epoxy group-containing compound (E) There,
The organic resin particles (A) modify the base resin into a state having a silanol group and / or an alkoxysilyl group by the silane coupling agent (A-1) and the polyfunctional epoxy group-containing compound (A-2) and a resin particle, lithium element total quantity of SiO2 in terms moles of silicon element contained in the silicon oxide particles (B) and the lithium silicate (C) is contained in the lithium silicate (C) 40 to 70 times the molar number of
Based on the total solid mass of the metal surface treatment agent,
The solid content mass of the organic resin particles (A) is 20 to 70% by mass,
10 to 50% by mass of the silicon oxide particles (B),
1 to 10% by mass of the lithium silicate (C),
The said organic titanium compound (D) is 0.05-5 mass% as titanium element conversion,
The content of the epoxy group-containing compound (E) is 0.2 to 10% by mass,
The ratio of the mass of the lithium silicate (C) to the mass of the titanium element contained in the organic titanium compound (D) is 0.2 to 200.
Metal surface treatment agent for galvanized steel. The mass in terms of the silane coupling agent (A-1) of the organic resin particles (A) relative to the sum of the mass of the titanium element contained in the organic titanium compound (D) and the mass of lithium silicate (C) The metal surface treatment agent for galvanized steel according to claim 1, wherein a ratio of is 0.01 to 13. Sum of solid content mass of the metal surface treatment agent of one or more niobium compounds (F) selected from the group consisting of niobium oxide, niobic acid and salts thereof, fluoroniobate salts, and fluorooxoniobate salts The metal surface treatment agent for galvanized steel products according to claim 1 or 2, wherein the content is 0.1 to 10% by mass.   The zinc plated steel material according to any one of claims 1 to 3, wherein the phosphoric acid compound (G) is contained in an amount of 0.1 to 10% by mass based on the total mass of the solid content of the metal surface treatment agent as phosphorus element conversion. Metal surface treatment agent.   The organic resin particles (A) are obtained by blending and reacting a silane coupling agent (A-1) in a ratio of 1 to 20% by mass with respect to the solid content mass of the base resin. The metal surface treatment agent for galvanized steel products according to any one of Items 1 to 4.   The organic resin particles (A) are obtained by blending and reacting the polyfunctional epoxy group-containing compound (A-2) in a proportion of 1 to 20% by mass with respect to the solid content mass of the base resin. The metal surface treatment agent for galvanized steel products according to any one of claims 1 to 5. The SiO ₂ conversion mole number of the total amount of silicon elements contained in the silicon oxide particles (B) and the lithium silicate (C) corresponds to the Li ₂ O conversion of the lithium element contained in the lithium silicate (C) The metal surface treatment agent for galvanized steel products according to any one of claims 1 to 6, which is 50 to 65 times the number of moles.   A method of coating a galvanized steel material, comprising applying the metal surface treatment agent for galvanized steel material according to any one of claims 1 to 7 onto the surface of the galvanized steel material to form a film. The coated steel material by which the film of the metal surface treatment agent for galvanized steel materials in any one of Claims 1-7 was coat | covered by the galvanized steel material .