WO2017078105A1 - Aqueous surface treatment agent for zinc plated steel material or zinc-based alloy plated steel material, coating method, and coated steel material - Google Patents

Abstract

[Problem] To provide: an aqueous surface treatment agent that is for a zinc plated steel material or a zinc-based alloy plated steel material, that has satisfactory properties such as corrosion resistance, post-degreasing corrosion resistance, coating adhesion, post-degreasing coating adhesion, blackening resistance, condensation whitening resistance, treatment agent stability, actual device operability, and the like, and that can form a coating having excellent stack whitening resistance and filament tape resistance; a coating method using the treatment agent; and a coated steel material obtained using the method. [Solution] This aqueous surface treatment agent for a zinc plated steel material or a zinc-based alloy plated steel material is obtained by blending a cationic polyurethane resin (A), a cationic phenolic resin (B), a silane coupling agent (C), an acetylacetone complex of titanium (D), an olefin wax (F), a vanadium compound (E), an acetic acid component (G), a phosphoric acid component (H), and water.

Description

Aqueous surface treatment agent for galvanized steel or zinc-base alloy-plated steel, coating method and coated steel

The present invention relates to an aqueous surface treating agent for galvanized steel or zinc-based alloy plated steel, a coating method using this treating agent, and a coated steel obtained using this method.

Many technologies have been proposed so far for surface-treated steel sheets that have a chromium-free rust-preventing film with resin as the main component and, if necessary, other organic or inorganic components added to the surface of steel sheets such as galvanized steel sheets. ing. These rust preventive coatings are required to have performance such as corrosion resistance, corrosion resistance after degreasing, coating adhesion, coating adhesion after degreasing, blackening resistance, anti-condensation whitening, treatment agent stability, and actual machine operability.

For example, Patent Document 1 contains a raw material of a olefinic wax surface-modified with a cationic resin, a siloxane compound, a titanium compound, a vanadium compound, and preferably a silicon compound in a zinc-based plated steel sheet base material in a specific ratio. There has been proposed a technique for forming a poorly water-soluble film in which the total content of strong electrolyte components remaining in the film is less than 0.3 mg · m ⁻² by application of an aqueous treatment liquid and baking drying.

Japanese Patent No. 522050

Here, when the present inventors evaluated the surface treatment agent for forming the surface treatment film in the surface-treated steel sheet described in Patent Document 1, the stability of the treatment agent is not sufficiently considered. It has been found. As a result of studies to improve the stability of the treatment agent, it has been found that when acetic acid is added to the surface treatment agent described in Patent Document 1, the treatment agent stability of the surface treatment agent is improved.

However, as a result of further studies by the present inventors, the present inventors have newly found that when the surface treatment agent described in Patent Document 1 is mixed with acetic acid, the stack whitening resistance and the filament tape resistance deteriorate. It turns out that a problem arises. Stack whitening resistance means the resistance to whitening of the surface-treated film in a state simulating the storage conditions during coil storage of the surface-treated steel sheet, and its performance evaluation is consistent with the surface-treated steel sheet under high temperature and high humidity conditions. Pressure is applied (stack), and the appearance after a certain period of time is evaluated. In addition, the filament tape resistance means using the filament tape to temporarily fix the end of the coil of the surface-treated steel sheet, but means the resistance of the surface-treated film to the filament tape, and its performance evaluation is After applying the filament tape to the surface-treated steel sheet, the appearance after peeling the filament tape after a certain period of time under high temperature and high humidity conditions is evaluated. The cause of the deterioration of stack whitening resistance is that acetic acid remaining in the surface treatment film becomes water-containing due to high humidity, and the zinc galvanized layer of the galvanized steel sheet, which is the base material, is attacked. This is thought to be due to the tendency to occur. Moreover, the cause of the deterioration of the resistance to filament tape is that acetic acid remaining in the surface-treated film becomes water-containing due to high humidity, and the adhesive layer of the filament tape is damaged, thereby reducing the adhesion of the filament tape. This is thought to be due to film damage to the attachment part of the ment tape.

Therefore, the present invention has been made in view of the above circumstances, and is corrosion resistance, corrosion resistance after degreasing, coating adhesion, coating adhesion after degreasing, blackening resistance, condensation whitening resistance, processing agent stability, actual machine operability. Water-based surface treatment agent for galvanized steel or zinc-base alloy-plated steel material that can form a film with excellent resistance to stack whitening and filament tape, and a coating method using this treatment agent, and An object is to provide a coated steel material obtained by using this method.

As a result of intensive studies to solve the above problems, the present inventor has obtained a cationic polyurethane resin, a cationic phenol resin, a silane coupling agent, an acetylacetone complex of titanium, a vanadium compound, and an olefin wax. An aqueous surface treatment agent for galvanized steel or zinc-based alloy-plated steel that can form a film with excellent stack whitening resistance and filament tape resistance by adding an acetic acid component and a phosphoric acid component to water. Based on this finding, the present invention has been completed.

That is, the present invention includes a cationic polyurethane resin (A), a cationic phenol resin (B), a silane coupling agent (C), an acetylacetone complex of titanium (D), a vanadium compound (E), and acetic acid. A water-based surface treatment agent for galvanized steel or zinc-based alloy-plated steel material comprising a component (G) and a phosphoric acid component (H) mixed in water, wherein the solid content (V) of the water-based surface treatment agent The ratio (NC) / (NV) of the silane coupling agent (C) to the mass in terms of SiO _{2 with} respect to the mass of 0.16 to 0.19 and the mass of the solid content (V) The ratio (ND) / (NV) to the mass (ND) in terms of Ti of the acetylacetone complex (D) is 0.0170 to 0.0240, and the vanadium compound (E) with respect to the mass of the solid content (V). Ratio (NE) / (NV) to mass (NE) in terms of V is 0.0070 to 0.0090, ratio of mass of acetic acid component (G) to mass of solid content (V) (NG) / (NV) is 0.040 to 0.140, and the ratio (NH) / (NV) of the phosphoric acid component (H) to the mass of the solid content (V) is 0.025 to 0.075. The ratio (ND) / (NE) of the acetylacetone complex (D) of titanium to the mass of Ti of the vanadium compound (E) in terms of V is 2.10 to 2.90, the acetic acid component ( The ratio (NH) / (NG) of the phosphoric acid component (H) to the mass of G) is 0.25 to 1.10, and the mass (ND) in terms of Ti of the acetylacetone complex (D) of titanium. To the mass of the phosphoric acid component (H) ( H) / (ND) is 1.11 to 3.19, which is for galvanized steel or zinc base alloy plated steel product for aqueous surface-treating agent.

The water-based surface treatment agent for galvanized steel or zinc-based alloy-plated steel further includes a ratio of the olefin wax (F) to the mass of the olefin wax (F) with respect to the mass of the solid content (V). It may contain 0.035 to 0.060 as (NF) / (NV). The olefin wax (F) is surface-modified with a silane coupling agent (I), and the ratio of the mass of the silane coupling agent (I) to the mass of the olefin wax (F) (NI / NF). ) May be 0.025 to 0.035. Further, the olefin wax (F) may have an average particle size of 0.05 to 0.15 μm.

The vanadium compound (E) may be an acetylacetone complex of vanadium. The olefin wax (F) may be surface-modified with an epoxy group-containing silane coupling agent.

In the water-based surface treating agent for galvanized steel or zinc-based alloy-plated steel, the cationic polyurethane resin (A) is a polycarbonate-based water-dispersible cationic polyurethane resin containing a structural unit represented by the general formula (1) There may be.

In the formula (1), R is an aliphatic alkylene group having 4 to 9 carbon atoms, and n is an integer corresponding to a number average molecular weight in the range of 500 to 5000.

Further, the cationic phenol resin (B) may be a polymer molecule having an average polymerization degree of 2 to 50 having a repeating unit represented by the general formula (2).

In the formula (2), Y1 and Y2 each independently represent hydrogen or a Z group represented by the general formula (3) or (4), and the average number of substitutions of Z groups per benzene ring is 0.2. ~ 1.0.

In formulas (3) and (4), R1, R2, R3, R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms, ^- represents a hydroxide ion or an oxo acid ions.

Further, the present invention is a coating method in which a coating is formed by applying the above-described aqueous surface treatment agent for galvanized steel or zinc-base alloy-plated steel to galvanized steel or zinc-base alloy-plated steel.

Further, the present invention is a coated steel material obtained by the above coating method.

According to the present invention, an aqueous surface treatment agent for galvanized steel or zinc-based alloy-plated steel material capable of forming a film excellent in stack whitening resistance and filament tape resistance, a coating method using this treatment agent, and this It becomes possible to provide the coated steel material obtained by using the method.

Furthermore, the present invention is excellent in the anti-condensation whitening property, which is one of the important required properties regarding the surface appearance quality of the surface-treated steel sheet used without coating, and further contains an olefin wax (F) as an optional component. By doing so, it is possible to improve the oil-free lubricity and handleability (that is, the coil deformation resistance and the cut plate pile load collapse resistance).

Hereinafter, preferred embodiments of the present invention will be described in detail. The aqueous surface treatment agent, coating method, and coated steel material for galvanized steel or zinc-based alloy plated steel according to the present invention will be described in the following order.
[Aqueous surface treatment agent for galvanized steel or zinc-based alloy-plated steel]
(component)
<Cationic polyurethane resin (A)>
<Cationic phenol resin (B)>
<Silane coupling agent (C)>
<Titanium acetylacetone complex (D)>
<Vanadium compound (E)>
<Olefin wax (F)>
<Acetic acid component (G)>
<Phosphoric acid component (H)>
<Unsuitable component>
(Mixing ratio)
<(NC) / (NV)>
<(ND) / (NV)>
<(NE) / (NV)>
<(NF) / (NV)>
<(NG) / (NV)>
<(NH) / (NV)>
<(ND) / (NE)>
<(NH) / (NG)>
<(NH) / (ND)>
(Physical properties)
<PH>
[Coating method]
(Base material: Galvanized steel or zinc-base alloy plated steel)
(Processing process)
[Coated steel]
(Amount of coating)

[Aqueous surface treatment agent for galvanized steel or zinc-based alloy-plated steel]
The aqueous surface treating agent for galvanized steel or zinc-based alloy plated steel according to the present invention includes at least a cationic polyurethane resin (A), a cationic phenol resin (B), a silane coupling agent (C), This is an aqueous surface treatment agent comprising titanium acetylacetone complex (D), vanadium compound (E), acetic acid component (G), and phosphoric acid component (H) in water. Moreover, the compounding ratio of each component in this aqueous surface treating agent is as follows.
(1) The ratio (NC) / (NV) of the silane coupling agent (C) to the mass in terms of SiO _{2 with} respect to the mass of the solid content (V) of the aqueous surface treating agent of the present invention is 0.16 to 0.00. 19
(2) The ratio (ND) / (NV) of the mass of acetylacetone complex (D) of titanium to the mass (ND) in terms of Ti with respect to the mass of solid content (V) is 0.0170 to 0.0240.
(3) The ratio (NE) / (NV) of the vanadium compound (E) to the mass (NE) in terms of V with respect to the mass of the solid content (V) is 0.0070 to 0.0090.
(4) The ratio (NG) / (NV) of the mass of the acetic acid component (G) to the mass of the solid content (V) is 0.040 to 0.140.
(5) The ratio (NH) / (NV) of the mass of the phosphoric acid component (H) to the mass of the solid content (V) is 0.025 to 0.075.
(6) The ratio (ND) / (NE) of the acetylacetone complex of titanium (D) to the mass in terms of Ti with respect to the mass in terms of V of the vanadium compound (E) is 2.10 to 2.90.
(7) The ratio (NH) / (NG) of the mass of the phosphoric acid component (H) to the mass of the acetic acid component (G) is 0.25 to 1.10.
(8) The ratio (NH) / (ND) of the phosphoric acid component (H) to the mass (ND) in terms of Ti of the acetylacetone complex (D) of titanium is 1.11 to 3.19.

Hereinafter, the composition (component, compounding ratio) and physical properties of the aqueous surface treatment agent for galvanized steel or zinc-based alloy plated steel according to the present invention will be described in detail.

(component)
First, the component mix | blended with the aqueous surface treating agent of this invention is described.

<Cationic polyurethane resin (A)>
The cationic polyurethane resin (A) is blended as an essential component in the aqueous surface treatment agent of the present invention, and is formed using the aqueous surface treatment agent of the present invention (that is, formed by application and drying of the aqueous surface treatment agent). It is a resin that forms the main component of a poorly water-soluble film (hereinafter also simply referred to as “slightly water-soluble film”). Since the treating agent to be used is aqueous, an aqueous resin is used as the cationic polyurethane resin (A) to be contained in the treating agent. Water-based resins are roughly classified into water dispersibility, emulsion, and water solubility. In the present invention, it is preferable to use a water dispersible resin in order to obtain a film having condensation whitening resistance and water resistance. . Since the water-soluble resin is an equilibrium dissolution system, a strong electrolyte component (fluorine, lithium, sodium, potassium, chlorine, bromine, sulfuric acid, sulfurous acid, nitric acid, nitrous acid, acetic acid, formic acid, propionic acid, Ions such as sulfonic acids, etc.) are required (condensation whitening is likely to occur when the strong electrolyte component substantially remains in the film), and in the emulsion, the surfactant remains in the film, This is because the water resistance may deteriorate.

The water-dispersible resin is preferably a type in which the resin particle surface is amine-modified and cation-dispersed, that is, a cationic water-dispersible resin. By cation dispersion, coexistence with a silane coupling agent (C) described later becomes possible. In the anion dispersion, the treatment agent becomes alkaline and the silane coupling agent becomes unstable. In that case, the silane coupling agent can be added to the alkaline treatment agent by dissolving the silane coupling agent using lithium hydroxide, sodium hydroxide or the like as a counter cation, but the addition of strong electrolyte ions such as lithium and sodium This is not preferable because the condensation whitening resistance deteriorates.

The particle size of the water dispersible resin is preferably in the range of 9 nm to 200 nm. The larger the particle size of the water-dispersible resin, the more the adverse effect of hydrophilization due to amine modification can be reduced.

As the cationic water-dispersible resin as described above, in the present invention, a cationic polyurethane resin (A) is blended in the treating agent. Since the film mainly composed of the cationic polyurethane resin (A) has an excellent balance between tensile strength and elongation, processability and adhesion are improved.

The cationic polyurethane resin (A) is preferably a polycarbonate-based water-dispersible cationic polyurethane resin containing a structural unit represented by the following general formula (1). When the cationic polyurethane resin (A) contains a structural unit represented by the following general formula (1), more excellent barrier properties are imparted, and condensation whitening resistance is improved.

In the above formula (1), R is an aliphatic alkylene group having 4 to 9 carbon atoms, and n is a number average molecular weight of a carbonate-based polyol that is a raw material of the polycarbonate-based cationic polyurethane resin (A) of 500 to An integer corresponding to the range of 5000.

<Cationic phenol resin (B)>
In addition to the cationic polyurethane resin (A), a cationic phenol resin (B) is further blended as an essential component in the aqueous surface treating agent of the present invention. When the aqueous surface treating agent of the present invention contains the cationic phenol resin (B), the stability of the treating agent is improved. Moreover, when the poorly water-soluble film | membrane of this invention contains a cationic phenol resin (B), topcoat water-resistant secondary adhesiveness will improve.

The cationic phenol resin (B) preferably has a repeating unit represented by the following general formula (2), and more preferably a polymer molecule having an average degree of polymerization of 2 to 50 of the repeating unit. When the average degree of polymerization is within this range, the water resistance of the film is improved. The average degree of polymerization of the repeating unit of formula (2) can be determined from the integration ratio by ¹ H-NMR.

In the above formula (2), Y1 and Y2 each independently represent hydrogen or a Z group represented by the general formula (3) or (4), and the average number of substitutions of Z groups per benzene ring is 0.00. 2 to 1.0. The average number of substitutions of the Z group can be determined from the integration ratio by ¹ H-NMR.

In the above formulas (3) and (4), R1, R2, R3, R4 and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms, A ⁻ represents a hydroxide ion or an oxo acid (eg, nitric acid, sulfuric acid, phosphoric acid, carbonic acid, carboxylic acid, etc.) ion.

As described above, the counter anion of the cationic resin (cationic polyurethane resin (A) and cationic phenol resin (B)) used in the present invention is an anion that volatilizes under dry film formation, specifically formic acid or Acetate ions are preferred. When the counter anion of the cationic resin is a hydroxide ion, the treatment agent is inclined to alkalinity, and as described above, the silane coupling agent is easily gelled and the liquid becomes unstable.

When the counter anion of the cationic resin is formic acid or acetate ion, formic acid or acetic acid volatilizes during dry film formation. As a result, in the cationic resin, the amine loses its charge, and irreversible aggregation as a film-forming reaction occurs due to the hydrophobicity of the resin particles. At the same time, volatilization of the counter anion increases the pH, and the silane coupling agent silanolized by hydrolysis advances irreversible gelation and condensation as a film-forming reaction. At this time, a network of resin, siloxane, metalloxane bond is formed by reaction between the side chain of the cationic polyurethane resin (A) and the cationic phenol resin (B) and the silane coupling agent, and reaction between the silanol and the plating substrate. Therefore, a strong film excellent in adhesion, corrosion resistance, and solvent resistance can be formed.

<Silane coupling agent (C)>
In the aqueous surface treating agent of the present invention, a silane coupling agent (C) is blended as an essential component. The silane coupling agent (C) undergoes hydrolysis and condensation in the film formation (baking) process to form a siloxane-type film that is three-dimensionally crosslinked by a siloxane bond. That is, the poorly water-soluble film of the present invention contains a siloxane compound (C ′). By using not only the cationic polyurethane resin (A) and the cationic phenol resin (B) but also the siloxane compound (C ′) as a film-forming component, the corrosion resistance, adhesion, and solvent resistance of the formed film are improved. Performance is significantly improved.

As the silane coupling agent (C) used as a raw material for the siloxane compound (C ′), it is preferable to use an alkoxysilane having 2 or more, preferably 3 or more alkoxy groups. The partial hydrolyzate can also be used.

The alkoxy group of the silane coupling agent (C) is hydrolyzed by addition to an aqueous system to form silanol (—Si—OH). Silanol dispersion stability is obtained at pH 6.5 or less. If the pH of the treatment agent exceeds 6.5, pot life cannot be obtained due to gelation.

Commercial products can also be used as the silane coupling agent (C). Examples of commercially available products include N- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, vinyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane and the like. Preferred silane coupling agents (C) are those having a functional group reactive with the cationic polyurethane resin (A) and the cationic phenol resin (B) to be used (for example, 3-aminopropyltriethoxysilane, 3-glycol Sidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like are preferable, and 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and the like are particularly preferable. The kind of reaction with these cationic resins may be polymerization reaction, condensation reaction, addition reaction or the like, and is not particularly limited.

<Titanium acetylacetone complex (D)>
In the aqueous surface treatment agent of the present invention, an acetylacetone complex (D) of titanium is also blended as an essential component. The titanium acetylacetone complex (D) is blended with the treating agent of the present invention, and the hardly water-soluble film formed contains a titanium compound (D ′) that is a reaction precipitate of the titanium acetylacetone complex (D). Corrosion resistance is greatly improved.

When a titanium acetylacetone complex is added to the treatment agent, the corrosion resistance of the poorly water-soluble film formed is further improved, and acetylacetonate and acetylacetone remaining in the dry film-forming film are weakly ionic and dew condensation occurs. Does not adversely affect whitening. Titanium acetylacetone complex reacts with the plating substrate under dry film formation to form a hardly water-soluble film. Of the titanium chelate compounds, the triethanolamine complex having a cationic property is preferable in that it does not adversely affect condensation whitening, but the triethanolamine remaining in the film after dry film formation exhibits water absorption, so that it has corrosion resistance. The improvement effect is greater with the acetylacetone complex. Titanium hydrofluoric acid and ammonium titanium fluoride are not suitable because fluorine is liberated and the resistance to condensation whitening deteriorates.

<Vanadium compound (E)>
In the aqueous surface treatment agent of the present invention, the vanadium compound (E) is also blended as an essential component. The vanadium compound (E) is blended with the treatment agent of the present invention, and the formed hardly water-soluble film contains the vanadium compound (E ′) which is a reaction precipitate of the vanadium compound (E), so that the corrosion resistance is very high. improves.

Examples of the vanadium compound (E) include vanadium pentoxide not containing a strong electrolyte, metavanadate and its salt (for example, ammonium metavanadate), vanadium trioxide, vanadium dioxide, vanadium oxyacetylacetonate, vanadium acetylacetonate, and the like. And vanadium acetate which is a salt with a volatile acid. Considering the effect of improving corrosion resistance, vanadium acetylacetone complexes such as vanadium acetylacetonate and vanadium oxyacetylacetonate are preferable. As will be described later, the vanadium compound (E ′) is immobilized in the film as an oxide or an acetylacetone complex.

<Olefin wax (F)>
In the aqueous surface treating agent of the present invention, the olefin wax (F) is preferably blended as an optional component. The olefin wax (F) is more preferably surface-modified with a silane coupling agent (I). When the poorly water-soluble film of the present invention contains the olefin wax (F) surface-modified with the silane coupling agent (I), it is dispersed in the film without being exposed to the surface, so that it is oil-free lubrication And handleability, that is, coil deformation resistance and cut plate pile load collapse resistance can both be achieved. The reason why the olefinic wax (F) is dispersed in the film is thought to be because the surface tension of the silane coupling agent (I) increases the surface tension of the wax and the wettability to the treatment agent increases.

Generally, in a lubricious film to which a solid lubricant such as wax is added, the wax is concentrated on the film surface by liquid convection under dry film formation, and it is not easy to uniformly disperse the wax in the film. However, the wax particles can be uniformly dispersed in the film by surface modification with a silane coupling agent.

As the silane coupling agent (I), a silane coupling agent having a reactive functional group is preferably used. The surface modification with the silane coupling agent (I) can be carried out by directly mixing the silane coupling agent (I) into the olefin wax emulsion. As a result, a surface-modified olefin wax that is stable in an acidic treatment solution having a pH of 6.5 or less containing a cationic polyurethane resin, a cationic phenol resin, and a silane coupling agent is obtained. Examples of the olefin wax (F) that can be used include polyethylene wax, oxidized polyethylene wax, oxidized polypropylene wax, and the like. As the olefin wax (F) surface-modified with the silane coupling agent (I) of the present invention, a silane coupling agent containing an epoxy group in a polyethylene wax emulsion having a carboxyl group that is stable in an acidic treatment solution (for example, The surface-modified olefin wax obtained by directly mixing glycidylpropyltrimethoxysilane) is preferable.

Further, the ratio (NI / NF) of the mass of the silane coupling agent (I) to the mass of the olefin wax (F) is preferably 0.025 to 0.035. By making NI / NF 0.025 or more, handleability can be improved. Moreover, workability can be improved by making NI / NF 0.035 or less. The addition amount of the silane coupling agent (I) is preferably equimolar or more with the acid value of the wax dispersion.

Furthermore, the average particle diameter of the olefin wax (F) is preferably 0.05 to 0.15 μm. If the wax particle size is 0.15 μm or less, the volume of the wax present on the surface of the film is reduced and the handleability is improved, and if it is 0.05 μm or more, the processability is improved and the treatment agent is stabilized by wax aggregation. There is little adverse effect on sex. The average particle diameter of the olefin wax (F) is a value measured by a laser diffraction / scattering method.

<Acetic acid component (G)>
An acetic acid component (G) is blended as an essential component in the aqueous surface treating agent of the present invention. By mix | blending an acetic acid component (G), the liquid stability (processing agent stability) of a processing agent improves. This is presumed to be because the pH buffering action of the acetic acid component (G) stabilizes the pH of the treatment agent in the vicinity of 3.5 to 4.0, and the condensation reaction of the silane coupling agent (C) becomes slow. . According to the study by the present inventors, it is known that the pH at which the condensation reaction of the silane coupling agent (C) is slowest is around 3.5 to 4.0. Acetic acid has a boiling point of 118 ° C., but the organic acid having a buffering action has a low boiling point and is relatively difficult to remain in the film. For this reason, it is suitable as an organic acid to be contained in the surface treatment agent.

Examples of the acetic acid component (G) include acetic acid, ammonium acetate, potassium acetate, and sodium acetate. Considering the effect of improving the treatment agent stability, acetic acid is particularly preferable.

<Phosphoric acid component (H)>
In the aqueous surface treating agent of the present invention, the phosphoric acid component (H) is blended as an essential component. When the phosphoric acid component (H) is blended and the poorly water-soluble film formed contains the phosphoric acid component (H), it reacts with the galvanized layer of the galvanized steel or zinc-base alloy-plated steel material. Since zinc phosphate film is generated, elution of zinc from the galvanized layer can be suppressed. As a result, the occurrence of white rust of zinc is suppressed, and the stack whitening resistance is improved. In addition, the amount of acetic acid remaining in the film can be reduced by adding the phosphoric acid component (H) to the treatment agent. As a result, the adhesive layer of the filament tape is not attacked and the filament tape is closely attached. Deterioration can be suppressed.

Examples of the phosphoric acid component (H) include inorganic phosphoric acid such as phosphoric acid and inorganic phosphoric acid compounds such as ammonium phosphate, potassium phosphate, sodium phosphate, and monosodium dihydrogen phosphate. In view of the effect of improving stack whitening resistance and filament tape resistance, inorganic phosphoric acid compounds and inorganic phosphoric acid are preferable, and phosphoric acid is particularly preferable.

<Unsuitable component>
The aqueous surface treatment agent of the present invention preferably contains no colloidal silica. When colloidal silica is blended in the aqueous surface treatment agent of the present invention, the silane coupling agent (C) reacts with the colloidal silica and the treatment agent stability decreases, which is not preferable. The aqueous surface treatment agent of the present invention preferably contains no basic alkali silicate. The aqueous surface treatment agent of the present invention is acidic, and if an alkaline basic silicate that is alkaline is blended, the treatment agent stability is lowered, which is not preferable.

(Mixing ratio)
Next, the blending ratio of the components blended in the aqueous surface treatment agent of the present invention will be described.

<(NC) / (NV)>
The ratio (NC) / (NV) of the silane coupling agent (C) to the mass in terms of SiO _{2 with} respect to the mass of the solid content (V) of the aqueous surface treating agent of the present invention is 0.16 to 0.19. Yes, preferably from 0.16 to 0.18. When (NC) / (NV) exceeds 0.19, the primary adhesion is lowered, and when it is less than 0.16, sufficient planar portion corrosion resistance cannot be obtained.

<(ND) / (NV)>
The ratio (ND) / (NV) of the mass of acetylacetone complex (D) of titanium to the mass (ND) of Ti with respect to the mass of the solid content (V) is 0.0170 to 0.0240, preferably 0. 0190-0.0230. When (ND) / (NV) is less than 0.0170, the corrosion resistance after degreasing deteriorates, and when it exceeds 0.0240, the effect of improving the corrosion resistance after degreasing is saturated and the adhesion after degreasing is reduced. To do.

<(NE) / (NV)>
The ratio (NE) / (NV) of the vanadium compound (E) to the mass (NE) in terms of V with respect to the mass of the solid content (V) is 0.0070 to 0.0090, preferably 0.0075. ~ 0.0090. When (NE) / (NV) is less than 0.0070, a sufficient effect of improving the corrosion resistance of the cut portion cannot be obtained, and when it is more than 0.0090, the effect of improving the corrosion resistance of the cut portion is saturated and the secondary adhesion is achieved. Decreases.

<(NF) / (NV)>
The ratio (NF) / (NV) of the mass of the olefin wax (F) to the mass of the solid content (V) is preferably 0.035 to 0.060, more preferably 0.040 to 0. .055. When (NF) / (NV) is 0.035 or more, sufficient oil-free lubricity is obtained, so that workability is improved. On the other hand, when (NF) / (NV) is 0.060 or less, the coil deformation resistance and the cut plate pile load collapse resistance are improved, and the handleability is improved.

<(NG) / (NV)>
The ratio (NG) / (NV) of the mass of the acetic acid component (G) to the mass of the solid content (V) is 0.040 to 0.140, preferably 0.050 to 0.130. More preferably, it is 0.060 to 0.120. When (NG) / (NV) is less than 0.040, a sufficient effect of improving the stability of the processing agent cannot be obtained, and when it exceeds 0.140, the effect of improving the stability of the processing agent is saturated and the condensation resistance is increased. Whitening property decreases.

<(NH) / (NV)>
The ratio (NH) / (NV) of the mass of the phosphoric acid component (H) to the mass of the solid content (V) is 0.025 to 0.075, preferably 0.030 to 0.070. More preferably, it is 0.035 to 0.065. When (NH) / (NV) is less than 0.025, a sufficient zinc elution suppression effect from the plating layer cannot be obtained, and when it exceeds 0.075, the zinc elution suppression effect is saturated and black resistance Denaturation is reduced.

<(ND) / (NE)>
In addition, the ratio (ND) / (NE) of the acetylacetone complex (D) of titanium to the mass of Ti in terms of V to the mass of vanadium compound (E) in terms of V is 2.10 to 2.90, preferably 2.20 to 2.80, more preferably 2.30 to 2.70. When (ND) / (NE) is less than 2.10, the fixing rate of the vanadium compound (E) to the film is lowered, and the corrosion resistance of the processed part is lowered. On the other hand, when (ND) / (NE) is more than 2.90, the fixing ratio of titanium to the acetylacetone complex (D) is lowered, and the processed portion corrosion resistance is lowered.

<(NH) / (NG)>
The ratio (NH) / (NG) of the mass of the phosphoric acid component (H) to the mass of the acetic acid component (G) is 0.25 to 1.10. When (NH) / (NG) is less than 0.25 and more than 1.10, stack whitening resistance is deteriorated. In order to enhance the effect of improving stack whitening resistance, (NH) / (NG) is preferably 0.30 to 1.00, more preferably 0.35 to 0.90.

<(NH) / (ND)>
The ratio (NH) / (ND) of the mass of the phosphoric acid component (H) to the mass (ND) in terms of Ti of the acetylacetone complex (D) of titanium is 1.11 to 3.19. When (NH) / (ND) is less than 1.11 and more than 3.19, the resistance to filament tape deteriorates. In order to enhance the effect of improving the filament tape resistance, (NH) / (ND) is preferably 1.40 to 3.00, and more preferably 1.80 to 2.81.

By dissolving or dispersing the above components in an aqueous solvent, a surface treatment agent used for film formation in the present invention can be prepared. Each component is adjusted so as to have a predetermined ratio in the film, and accordingly, adjusted to have a predetermined ratio with respect to the total amount of the non-volatile content (solid content) excluding the solvent and the volatile component. Since the treatment agent used in the present invention is aqueous, the solvent may be only water, but for the purpose of improving the drying property of the film, the water-soluble organic solvent (for example, alcohols) that does not contain the above-mentioned strong electrolyte. May be contained in a small amount (for example, within 30% by mass of the entire solvent). Further, additives commonly used in coating treatment liquids such as leveling agents and antifoaming agents can be added to the treatment agents.

(Physical properties)
Next, the physical property of the component mix | blended with the aqueous surface treating agent of this invention is described.

<PH>
As described above, the aqueous surface treatment agent of the present invention contains the cationic polyurethane resin (A) and the cationic phenol resin (B) as essential components, and also for the dispersion stabilization of the silane coupling agent (C). Preferably, the pH is in an acidic region of 6.5 or less. The preferred pH range of the aqueous surface treatment agent is 2.0 to 6.5. If necessary, volatile acids such as acetic acid and formic acid can be added to adjust the acidity (pH) of the treatment agent.

[Coating method]
As described above, the water-based surface treatment agent for galvanized steel or zinc-based alloy-plated steel according to the present invention has been described in detail. Subsequently, the above-described water-based surface treatment agent for galvanized steel or zinc-based alloy-plated steel was used. The coating method according to the present invention will be described. In the coating method according to the present invention, the above-described aqueous surface treatment agent for galvanized steel or zinc-base alloy-plated steel is applied to the galvanized steel or zinc-base alloy-plated steel (more specifically, galvanized steel or This is a surface treatment method for forming a film on the surface of a galvanized steel material or a zinc-based alloy-plated steel material by bringing it into contact with a zinc-based alloy-plated steel material and then drying it.

(Base material: Galvanized steel or zinc-base alloy plated steel)
Examples of the galvanized steel material or zinc base alloy plated steel material used in the present invention include zinc-nickel plated steel material, zinc-iron plated steel material, zinc-chromium plated steel material, zinc-aluminum plated steel material, zinc-titanium plated steel material, zinc -Zinc-coated steel materials such as magnesium-plated steel materials, zinc-manganese-plated steel materials, zinc-aluminum-magnesium-plated steel materials, zinc-aluminum-magnesium-silicon-plated steel materials, and small amounts of different metal elements or impurities in these plated layers As an inorganic substance such as cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic, etc., silica, alumina, titania, etc. Is distributed Murrell.

Furthermore, the present invention can also be applied to multilayer plating in which the above plating layer and other types of plating layers such as iron plating, iron-phosphorus plating, nickel plating, cobalt plating, etc. are combined. The formation of the plating layer is not particularly limited, and can be performed using any known method such as electroplating, hot dipping, vapor deposition, dispersion plating, and vacuum plating. The amount of plating adhesion is not particularly limited, and may be within the conventional general range. The plating may be either single-sided plating or double-sided plating. In the surface treatment method according to the present invention, when the substrate is a double-sided plated steel plate, a film can be formed on one side or both sides of the plated steel plate.

(Processing process)
Forming a film (poorly water-soluble film) on the surface of galvanized steel or zinc-based alloy-plated steel by bringing the above-mentioned aqueous surface treatment agent into contact with the above-mentioned galvanized steel or zinc-based alloy-plated steel, and then drying. Let This film is blended with the treatment agent of the present invention, the cationic polyurethane resin (A), the cationic phenol resin (B), the silane coupling agent (C), the acetylacetone complex of titanium (D), the vanadium compound (E ), Cationic polyurethane resin (A), cationic phenol resin (B), siloxane compound (C ′), titanium compound (D ′), vanadium compound derived from acetic acid component (G) and phosphoric acid component (H) (E '), an acetic acid component (G), and a phosphoric acid component (H) are included at least.

The contact method of the treatment agent of the present invention to the galvanized steel material or zinc-base alloy-plated steel material can be carried out by any conventional contact method such as dipping, spraying, roll coating or the like. Bake drying after contact. The heating temperature at that time is selected so that volatile components in the treatment agent (for example, acetic acid or formic acid derived from the counter anion of the cationic resin) are volatilized. It is preferable to perform the drying so that the maximum plate temperature (PMT) is in the range of 60 to 150 ° C. Baking and drying can be performed by hot air drying or oven drying.

In the baking and drying process, volatile acid components such as acetic acid are volatilized from the liquid film of the treatment agent, and the pH rises. As a result, the plating base and titanium acetylacetone complex, silane coupling agent, cationic polyurethane resin dispersion, and cationic phenol resin undergo hydrolysis and condensation reactions, and the plating base surface, resin, organosilane compound, titanium compound , And a vanadium compound forms a strong network by an ionomer bond, a metalloxane bond, or a siloxane bond, and a poorly water-soluble film having a structure in which the vanadium compound and the olefinic wax are fixed is formed.

[Coated steel]
Next, the coated steel material according to the present invention having a film (poorly water-soluble film) formed by using the above-described coating method will be described.

(Amount of coating)
The amount of the poorly water-soluble film attached may be 100 mg / m ² or more for the purpose of primary rust prevention (measures against rust during delivery to users), but bare use (omitting painting of final product) Is intended to be 300 mg / m ² or more. The upper limit of the coating amount is 3000 mg / m ² . If the adhesion amount is larger than that, the top coatability is lowered, and the handleability is also deteriorated even if the film does not contain wax. When spot welding is performed, it is preferable that the coating amount be 1500 mg / m ² or less.

The coated steel material of the present invention comprises at least a cationic polyurethane resin (A), a cationic phenol resin (B), a siloxane compound (C ′), a titanium compound (D ′), a vanadium compound (E ′), and an acetic acid component (G ) And a phosphoric acid component (H), a poorly water-soluble film is formed on the surface of the galvanized steel material or the zinc-base alloy plated steel material. Therefore, not only is it excellent in resistance to condensation whitening and corrosion, but it is also excellent in resistance to stack whitening and resistance to filament tape. In a preferred embodiment, when the coating contains an olefinic wax and further contains an olefinic wax (F) surface-modified with a silane coupling agent (I), the coating has no oil-coated lubricity. Moreover, since the wax is dispersed in the film without being exposed to the surface, the coil deformation resistance and the cut plate pile load collapse resistance are excellent.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples of the present invention, but the present invention is not limited to these examples.

1. Test materials The galvanized steel materials or zinc base alloy plated steel materials used in Examples and Comparative Examples are shown below.
Electro-galvanized steel sheet “NS Zincoat (registered trademark)” (hereinafter referred to as “EG”) and hot-dip galvanized steel sheet “NS Silver Zinc (registered trademark)” (hereinafter referred to as “GI”) manufactured by Nippon Steel & Sumitomo Metal Corporation. ), Galvannealed steel sheet “NS Silver Alloy (registered trademark)” (hereinafter referred to as “GA”), zinc-aluminum-magnesium-silicon alloy plated steel sheet “Superdimer (registered trademark)” ( Hereinafter referred to as “SD”), zinc-nickel alloy plated steel sheet “NS Zinclite (registered trademark)” (hereinafter referred to as “ZL”), and zinc-aluminum alloy plating manufactured by Nippon Steel & Sumikin Steel Sheet Co., Ltd. Steel plate “Galbarium Steel Plate (registered trademark)” (hereinafter referred to as “GL”), and zinc-aluminum-magnesium alloy plating manufactured by Nippon Steel & Sumikin Steel Co., Ltd. Plate "Esujieru steel plate (registered trademark)" (hereinafter, referred to as "SGL".) Was used as the original plate.
As the original plate, a plate having a thickness of 0.8 mm was used. As the EG, one having a plating adhesion amount of 20 g / m ² on one side was used. Moreover, as GI, GA, SD, GL, and SGL, those with a plating adhesion amount of 60 g / m ² on one side were used. As ZL, one having a plating adhesion amount of 20 g / m ² on one side and a nickel amount in the plating layer of 12% by mass was used.

2. Water-based surface treatment agent Each raw material used is described below.

[Cationic urethane resin (A)]
A1: Polycarbonate-based cationic polyurethane resin Superflex 650 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
A2: Polyester-based cationic polyurethane resin Adekabon titer HUX-680 manufactured by ADEKA Corporation
A3: Polyether-based cationic polyurethane resin Superflex 600 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
A4: Polyether-based anionic polyurethane resin Adekabon titer HUX-350 manufactured by ADEKA Corporation

[Cationic phenol resin (B)]
B1: Cationic phenol resin The average degree of polymerization n of the repeating unit of formula (2) n = 5, Y1 = —CH ₂ N (CH ₃ ) ₂ of formula (2), Y2 = H of formula (2), formula (2) ) Z substitution degree = 0.5
B2: Cationic phenol resin Average polymerization degree n of repeating unit of formula (2) = 10, Y1 of formula (2) = — CH ₂ N (CH ₃ ) (C ₂ H ₄ OH), Y2 of formula (2) = H, Z substitution degree of formula (2) = 1.0

[Silane coupling agent (C)]
C1: 3-aminopropyltriethoxysilane C2: 3-glycidoxypropyltrimethoxysilane C3: 3-mercaptopropyltrimethoxysilane

[Acetylacetone complex of titanium (D)]
D1: Titanium diisopropoxybisacetylacetonate D2: Titanium tetrakisacetylacetonato D3: Titanium diisopropoxybistriethanolamate

[Vanadium compound (E)]
E1: Vanadium acetylacetonate E2: Ammonium metavanadate

[Olefin wax (F)]
The olefin wax whose surface was modified with a silane coupling agent (3-glycidoxypropyltrimethoxysilane) shown in Table 1 below was used.

[Acetic acid component (G)]
G1: Acetic acid G2: Ammonium acetate

[Phosphoric acid component (H)]
H1: Phosphate H2: Ammonium phosphate

The processing agents used in the following Examples and Comparative Examples were prepared by mixing the components listed above in the composition shown in Table 2 below. In addition, solid content in a processing agent was adjusted so that it might become 11 mass%. In Table 2, the content of component (C) is the content in terms of SiO ₂ , the content of component (D) is the content in terms of Ti, and the content of component (E) is in terms of V Content.

3. Test plate preparation process Using the silicate alkaline degreasing agent Fine Cleaner E6406 (manufactured by Nihon Parkerizing Co., Ltd.) dissolved in water to a concentration of 20 g / L, the above-mentioned test was conducted for 10 seconds at a temperature of 60 ° C. What was applied to the material, further washed with pure water for 30 seconds and then dried was used in the following test. Each treatment agent was applied by a bar coater and dried in a hot air drying furnace so as to have a predetermined ultimate plate temperature (PMT). The details such as the amount of adhesion are shown in Table 3 below.

[Evaluation methods]
(1) Corrosion resistance Corrosion resistance tests were performed on unprocessed ones (planar part), cross-cut with a NT cutter until the substrate was reached (cross-cut part), and Erichsen 7 mm extruded (worked part). . The evaluation method is as follows.
1-1 (corrosion resistance of flat surface):
Based on the salt spray test method JIS-Z-2371, the white rust generation area ratio 72 hours after the salt spray was determined and evaluated. The evaluation criteria are shown below.
◎: White rust generation area ratio is less than 10% ○: White rust generation area ratio is 10% or more and less than 30% △: White rust generation area ratio is 30% or more and less than 60% ×: White rust generation area ratio is 60 % Or more (△ or more is practical performance)
1-2 (corrosion resistance of the cross cut part):
Based on the salt spray test method JIS-Z-2371, the occurrence of white rust 72 hours after the salt spray was evaluated with the naked eye. The evaluation criteria are shown below.
◎: Almost no rust generation ○: Slight rust generation is observed △: Rust generation is observed ×: Rust generation is remarkable (△ or more is practical performance)
1-3 (corrosion resistance of processed parts):
Based on the salt spray test method JIS-Z-2371, the occurrence of white rust 72 hours after the salt spray was evaluated with the naked eye. The evaluation criteria are shown below.
◎: Almost no rust generation ○: Slight rust generation is observed △: Rust generation is observed ×: Rust generation is remarkable (△ or more is practical performance)

(2) Alkali resistance (corrosion resistance after degreasing)
Fine cleaner E6406 (manufactured by Nihon Parkerizing Co., Ltd.) was bathed at 20 g / L, the test plate was immersed in a degreasing aqueous solution adjusted to 65 ° C. for 2 minutes, washed with water, and dried at 80 ° C. About this board, corrosion resistance was evaluated by the conditions and evaluation method of planar part corrosion resistance described in said (1).

(3) Coating adhesion The coating was applied to the test plate under the following conditions, and a coating film adhesion test was conducted.
Paint condition paint: Amirac # 1000 (registered trademark) (white paint) manufactured by Kansai Paint Co., Ltd.
Coating method: Bar coating method Baking and drying conditions: 140 ° C., 20 minutes Coating thickness: 25 μm

The evaluation method is as follows.
3-1 (cross-cut primary adhesion):
With respect to the test plate, 100 mm grids of 1 mm square were cut with an NT cutter, a peel test with an adhesive tape was performed, and the number of coating films peeled was evaluated. The evaluation criteria are shown below. The “number of peeled coating films” referred to here means the number of pieces from which more than half of each grid has been peeled (the “number of peeled coating films” described below has the same meaning).
◎: Number of peeled less than 1 ○: Number of peeled 1 or more and less than 10 △: Number of peeled 10 or more, less than 50 x: Number of peeled 50 or more
3-2 (secondary cross-cut adhesion):
The test plate was immersed in boiling water for 2 hours, left standing for a whole day and night, 1 mm square, 100 grids were cut with an NT cutter, a peel test with an adhesive tape was performed, and the number of peeled films was evaluated. The evaluation criteria are shown below.
◎: Number of peeled less than 1 ○: Number of peeled 1 or more and less than 10 △: Number of peeled 10 or more, less than 50 ×: Number of peeled 50 or more (△ or more is practical performance)

(4) Paint adhesion after degreasing Fine cleaner E6406 (manufactured by Nihon Parkerizing Co., Ltd.) was constructed at 20 g / L, immersed in a degreasing aqueous solution adjusted to 65 ° C. for 2 minutes, washed with water, and then 80 Dried at ℃. About this board, the coating was given with respect to the test board on the following conditions, and the coating-film adhesiveness test was done.
(Painting conditions)
Paint: Amirac # 1000 (registered trademark) (white paint) manufactured by Kansai Paint Co., Ltd.
Coating method: Bar coating method Baking and drying conditions: 140 ° C., 20 minutes Coating thickness: 25 μm

The evaluation method is as follows.
(Crosscut primary adhesion after degreasing)
With respect to the test plate, 100 mm grids of 1 mm square were cut with an NT cutter, a peel test with an adhesive tape was performed, and the number of coating films peeled was evaluated. The evaluation criteria are shown below.
◎: Number of peeled less than 1 ○: Number of peeled 1 or more and less than 10 △: Number of peeled 10 or more, less than 50 ×: Number of peeled 50 or more (△ or more is practical performance)

(5) Workability A test plate is fixed on a turntable, the turntable is rotated at a rotational speed of 100 mm / s, a pin-on-disk slider (f5 tool steel) is pressed against the test piece with a pressing load of 30 N, and the generated friction is applied. A pin-on-disk test to measure was performed. According to this test, the minimum value (dynamic friction coefficient) of the coefficient of friction of the uncoated oil test piece (measured average of 6 friction coefficients measured every 0.1 seconds) and the number of turns in which the friction coefficient exceeds 0.20 for the first time ( The number of seizure occurrence sliding was evaluated. In addition, this evaluation was implemented only with the processing agent containing the olefin wax (F) shown in Table 3. The evaluation criteria are shown below.
◎: Dynamic friction coefficient is less than 0.16, and seizure occurrence sliding frequency is 25 times or more. ○: Dynamic friction coefficient is less than 0.16, seizure occurrence sliding frequency is 20 times or more and less than 25 times, or dynamic friction coefficient. Is 0.16 or more and less than 0.18, and seizure occurrence sliding frequency is 25 times or more. ○-: Dynamic friction coefficient is 0.16 or more and less than 0.18, seizure occurrence sliding frequency is 20 times or more and less than 25 times. : Dynamic friction coefficient is 0.18 or more, seizure occurrence sliding number is 20 times or more, or dynamic friction coefficient is 0.16 or more and less than 0.18, seizure occurrence number is less than 20 times ×: Dynamic friction coefficient is 0 .18 or more and seizure occurrence sliding frequency is less than 20 times (Δ or more is practical performance).

(6) Handling characteristics In order to simulate pile collapse, a model of inertia system consisting of a small steel plate (steel 1) with a weight (weight 1) fixed with double-sided tape and a steel plate (steel 2) fixed with a bolt on a carriage is used. Created. By dropping the weight (weight 2) connected to the carriage via a wire / pulley, a constant impulse due to the collision of the carriage against the collision plate was applied to the inertial system to cause sliding. The sliding distance of the steel plate 1 at this time was measured, the sliding friction coefficient was calculated by the following formula 1, and evaluated as handleability. In addition, this evaluation was implemented only with the processing agent containing the olefin wax (F) shown in Table 3.
Test conditions: as shown in Table 4 below.
Sliding friction coefficient μ: μ = m3 × h / (m1 + m2) × L (Equation 1)
In Equation 1, m1 = weight of steel plate 1 + weight 1 (g), m2 = weight of steel plate 2 + cart, m3 = weight of weight 2 (g), h = fall distance of weight 2 (mm) ), L = sliding distance (mm)
The evaluation criteria are shown below.
A: Sliding friction coefficient is 0.85 or more O: Sliding friction coefficient is 0.84 or more and less than 0.85 Δ: Sliding friction coefficient is 0.83 or more and less than 0.84 ×: Sliding friction coefficient is less than 0.83 (The above is the practical performance.)

(7) Blackening resistance After holding the test plate in a wet box at a temperature of 70 ° C. and a relative humidity of 80% for 6 days, the test plate was taken out and the blackening state of the test plate was visually determined. The evaluation criteria are as follows.
◎: Area ratio of blackened area is less than 1% (no blackened)
○: Area ratio of blackened portion is 1% or more and less than 5% ○-: Area ratio of blackened portion is 5% or more and less than 25% Δ: Area ratio of blackened portion is 25% or more, 50 Less than% ×: Area ratio of blackened portion is 50% or more (Δ or more is practical performance)

(8) Stack whitening resistance 5-10 pairs of two test plates facing each other so that the painted surfaces face each other are overlapped, bolted at four corners, and torque wrench. The load was applied to a scale of 7 N · m. And after hold | maintaining for 6 days in the humidity box of the temperature of 70 degreeC and 80% of relative humidity, it took out and determined the whitening condition of the overlapping part visually. The evaluation criteria are as follows.
◎: Area ratio of whitened area is less than 1% (no whitening)
○: Area ratio of whitened portion is 1% or more and less than 5% ○-: Area ratio of whitened portion is 5% or more and less than 25% Δ: Area ratio of whitened portion is 25% or more, 50 Less than% ×: Area ratio of whitened portion is 50% or more (Δ or more is practical performance)

(9) Filament tape resistance Filament tape (registered trademark) no. After attaching 9514, it was peeled off after being held in a wet box at a temperature of 40 ° C. and a relative humidity of 80% for 7 days, and the appearance was evaluated. The evaluation criteria are as follows.
◎: The peeled part is not seen at all from an angle. ○: The peeled part is slightly seen from the oblique side. ○-: The peeled part is clearly seen from the oblique side. △: The peeled part is seen from the front. Slightly understood ×: The peeled portion can be clearly seen from the front (Δ or more is practical performance).

(10) Condensation whitening resistance One drop of ion-exchanged water is dropped on the surface of the test plate, and another test piece is stacked on the dropping surface side so that the films face each other, and water is sandwiched between the two test pieces. It was in a state. Subsequently, the test piece was wrapped, the four corners were clipped, and the presence or absence of whitening of the water droplet dropping portion after storage in a dryer at 50 ° C. for 72 hours was visually evaluated. The evaluation criteria are as follows.
◎: No whitening visually, no glossiness (loss of gloss) ○: No whitening visually, but glossiness (loss of gloss) ×: Visually whitening, glossiness (loss of gloss) Yes (○ or higher is practical performance)

(11) Stability of treatment agent 200 ml of the treatment agent immediately after preparation was put in an airtight container and kept at 40 ° C., and the solidification (gelation) state was observed at regular intervals to evaluate the period until solidification. The evaluation criteria are as follows.
◎: not solidified for 60 days or more ○: solidified for 30 days or more and less than 60 days Δ: solidified for 14 days or more and less than 30 days ×: solidified in less than 14 days (Δ or more is practical performance)

(12) Actual machine operability (Zn elution amount)
Ten hot-dip galvanized plates (75 × 40 mm) were immersed in 300 ml of a treatment agent at 25 ° C., and the amount of Zn in the treatment agent after 6 hours was evaluated. The evaluation criteria are as follows.
◎: Zn amount less than 700 mg / L ○: Zn amount is 700 mg / L or more and less than 850 mg / L Δ: Zn amount is 850 mg / L or more and less than 1000 mg / L ×: Zn amount is 1000 mg / L or more (△ or more is Practical performance.)

The evaluation results of (1) to (12) above are shown in Table 5 (Example) and Table 6 (Comparative Example).

[Evaluation results]
As can be seen from Table 5, Examples 1 to 78 using the treating agent containing the essential components of the present invention and containing these essential components in a blending ratio within the scope of the present invention are all corrosion resistance, alkali resistance, Excellent or practically satisfied with all evaluations of coating adhesion, coating adhesion after degreasing, blackening resistance, stack whitening resistance, filament tape resistance, condensation whitening resistance, processing agent stability and actual machine operability It became performance. In addition, Examples 1-27 and 29-78 blended with the olefin wax (F) were excellent in workability and handleability, or had practically satisfactory performance.

On the other hand, as can be seen from Table 6, Comparative Examples 1 to 14 and 17 to 22 which do not contain the essential component of the present invention or whose blending ratio of the essential component is outside the range of the present invention are corrosion resistance, alkali resistance, Performance that at least one of coating adhesion, coating adhesion after degreasing, blackening resistance, stack whitening resistance, filament tape resistance, condensation whitening resistance, treatment agent stability and actual machine operability is not satisfied in practice. It became. In Comparative Examples 15 and 16 using the anionic polyurethane resin A4, since the treatment agent could not be prepared, the evaluations (1) to (12) were not performed.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment. That is, it is understood that other forms or various modifications that can be conceived by those skilled in the art within the scope of the invention described in the claims belong to the technical scope of the present invention.

Claims (10)

1. A cationic polyurethane resin (A), a cationic phenol resin (B), a silane coupling agent (C), an acetylacetone complex of titanium (D), a vanadium compound (E), an acetic acid component (G), An aqueous surface treatment agent for galvanized steel or zinc-based alloy-plated steel comprising a phosphoric acid component (H) in water,
   The ratio (NC) / (NV) of the silane coupling agent (C) to the mass in terms of SiO _{2 with} respect to the mass of the solid content (V) of the aqueous surface treatment agent is 0.16 to 0.19,
   The ratio (ND) / (NV) of the mass of the acetylacetone complex (D) of titanium with respect to the mass of the solid content (V) (ND) / (NV) is 0.0170 to 0.0240,
   The ratio (NE) / (NV) of the vanadium compound (E) to the mass (NE) in terms of V with respect to the mass of the solid content (V) is 0.0070 to 0.0090,
   The ratio (NG) / (NV) of the mass of the acetic acid component (G) to the mass of the solid content (V) is 0.040 to 0.140,
   The ratio (NH) / (NV) of the mass of the phosphoric acid component (H) to the mass of the solid content (V) is 0.025 to 0.075,
   The ratio (ND) / (NE) of the mass of the acetylacetone complex (D) of titanium to the mass of Ti of the vanadium compound (E) in terms of V is 2.10 to 2.90,
   The ratio (NH) / (NG) of the mass of the phosphoric acid component (H) to the mass of the acetic acid component (G) is 0.25 to 1.10,
   Zinc plating in which the ratio (NH) / (ND) of the phosphoric acid component (H) to the mass (ND) in terms of Ti of the titanium acetylacetone complex (D) is 1.11 to 3.19 Aqueous surface treatment agent for steel or zinc-base alloy plated steel.
2. Furthermore, the olefinic wax (F) is contained in an amount of 0.035 to 0.060 as a ratio (NF) / (NV) of the olefinic wax (F) to the mass of the solid content (V). The aqueous surface treating agent for galvanized steel or zinc-based alloy-plated steel according to claim 1.
3. The olefin wax (F) is surface-modified with a silane coupling agent (I), and the ratio (NI / NF) of the mass of the silane coupling agent (I) to the mass of the olefin wax (F) is The aqueous surface treating agent for galvanized steel or zinc-based alloy plated steel according to claim 2, which is 0.025 to 0.035.
4. The water-based surface treating agent for galvanized steel or zinc-based alloy-plated steel according to claim 2 or 3, wherein the olefin wax (F) has an average particle size of 0.05 to 0.15 µm.
5. The aqueous surface treating agent for galvanized steel or zinc-based alloy plated steel according to any one of claims 1 to 4, wherein the vanadium compound (E) is an acetylacetone complex of vanadium.
6. The aqueous system for galvanized steel or zinc-based alloy plated steel according to any one of claims 2 to 5, wherein the olefin wax (F) is surface-modified with an epoxy group-containing silane coupling agent. Surface treatment agent.
7. The galvanized steel material according to any one of claims 1 to 6, wherein the cationic polyurethane resin (A) is a polycarbonate-based water-dispersible cationic polyurethane resin containing a structural unit represented by the general formula (1). Water-based surface treatment agent for use in zinc-based alloy-plated steel.
   

   

   [Wherein R is an aliphatic alkylene group having 4 to 9 carbon atoms, and n is an integer corresponding to a number average molecular weight in the range of 500 to 5000. ]
8. The galvanized steel material according to any one of claims 1 to 7, wherein the cationic phenol resin (B) is a polymer molecule having an average polymerization degree of 2 to 50 and having a repeating unit represented by the general formula (2). Water-based surface treatment agent for use in zinc-based alloy-plated steel.
   

   

   [Wherein Y1 and Y2 each independently represent hydrogen or a Z group represented by the general formula (3) or (4), and the average number of substitutions of Z groups per benzene ring is 0.2 to 1 .0. ]
   

   

   [In the formulas (3) and (4), R1, R2, R3, R4 and R5 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a hydroxyalkyl group having 1 to 10 carbon atoms, A ⁻ represents a hydroxide ion or an oxoacid ion. ]
9. A coating method for forming a film by applying the aqueous surface treating agent for galvanized steel or zinc-based alloy plated steel according to any one of claims 1 to 8 to a galvanized steel or zinc-based alloy plated steel.
10. A coated steel material obtained by the coating method according to claim 9.