KR20160141733A - Metal surface treatment agent for zinc-plated steel material, coating method, and coated steel material - Google Patents

Abstract

The metal surface treatment agent for a zinc-plated steel material of the present invention is a metal surface treatment agent for zinc-plated steel which contains an organic resin particle (A), a silicon oxide particle (B), a lithium silicate (C), an organic titanium compound (D), and an epoxy group- The organic resin particle (A) is a resin particle obtained by modifying a gas resin with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and the resin particle having a silanol and / or alkoxysilyl group particles, and the SiO ₂ in terms of the number of moles of the total amount of the silicon element contained in the silicon oxide particles (B), and the lithium silicate (C), for the Li ₂ O in terms of the number of moles of lithium element contained in the lithium silicate (C) And 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.

Description

TECHNICAL FIELD [0001] The present invention relates to a metal surface treatment agent, a coating method, and a coated steel material for a zinc-plated steel material,

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

Zinc-plated steel and the like have conventionally been widely subjected to chromate-rust-proofing treatment using a hexavalent chromate or the like, and coating with an organic resin is carried out in order to impart a weatherability, scratch resistance or the like, if necessary, Various paints were being overpainted.

In recent years, there has been a movement in which the chromate treatment that has been carried out on conventional steels is regulated or prohibited by laws and ordinances, with the background of environmental problems. Since the chromate treatment layer itself has a high degree of corrosion resistance and paint adhesion, when the chromate treatment can not be carried out, these performances are remarkably deteriorated. For this reason, it is required to form a rust preventive layer having good corrosion resistance and paint adhesion without performing chromate treatment.

Patent Document 1 discloses 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, a silicon oxide particle (B) having an average particle diameter of 5 to 50 nm, And a coating amount of 0.5 to ³ g / m < ² >, in which the organic titanium compound (C) is a composite coating. However, in the above-mentioned coating, the adhesion of the base material and the oil resistance of the inner press are improved, but further improvement of the inner tape peeling property is demanded.

In Patent Document 2, a treatment liquid containing an organic resin, a silane coupling agent, and a solid wetting agent in an aqueous lithium silicate solution having a SiO ₂ / Li ₂ O ratio (molar ratio) of 18 to 33 is applied to the surface of a metal sheet, Wherein the surface-treated metal sheet is characterized in that the surface-treated metal sheet is made of a metal. However, the above-mentioned metal plate has a problem that alkali resistance is poor.

Patent Document 3 discloses a surface-treated metal plate on which a surface treatment film is formed on a metal plate or a plated metal plate. The surface treatment film has Si and Li so that Si / Li (molar ratio) is 36 to 66, The surface-treated metal sheet does not have a surface-treated metal sheet. However, the above metal plate has a problem that the peelability of the inner tape is poor.

Patent Document 4 discloses a lithium silicate having an Si / Li molar ratio of 1 to 4 in an aqueous medium and a silane coupling agent in an amount of 5 to 50 parts by mass, 0.2 to 10 parts by mass in terms of 100 parts by mass of the lithium silicate, , A vanadium compound (as a vanadium metal), a titanium compound (as a titanium metal) in an amount of 0.2 to 10 parts by mass, and a wax in an amount of 0.01 to 10 parts by mass, . However, the surface treatment liquid for zinc-based plated metal materials is not sufficiently alkaline.

Japanese Patent No. 4922295 Japanese Patent Laid-Open No. 11-58599 Japanese Patent Application Laid-Open No. 2000-45078 Japanese Patent Application Laid-Open No. 2010-37584

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned phenomenon, and it is an object of the present invention to provide a metal surface treatment agent for a zinc-plated steel material having improved resistance to oil press, adhesion to a substrate, peelability to paint on a tape, coating adherence, A coating method using a treating agent, and a coated steel material.

Here, the peeling resistance of the tape indicates that the coated film is not peeled off when the tape is peeled off even if the coil or the workpiece of the steel is fixed with a highly adhesive tape when exposed to high temperature and high humidity conditions, The term "resistance" refers to resistance to abrasion flaws which may be generated by friction when a steel coil or a workpiece is transported.

As a result of intensive studies, the inventors of the present invention have found that a zinc-plated steel sheet containing a specific organic resin particle (A), silicon oxide particles (B), lithium silicate (C), an organic titanium compound (D), and an epoxy group- Wherein the molar ratio of the total amount of the silicon oxide particles (B) and the silicon contained in the lithium silicate (C) to the SiO _{2 in} terms of SiO ₂ is less than the molar ratio Li ₂ O of the lithium element contained in the lithium silicate (C) , And 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. The metal surface treating agent for zinc- Oil film, base material adhesion, substrate tape peelability, paint adhesion, processed portion corrosion resistance, alkali resistance, and releasability. Thus, the present invention has been completed.

That is, the present invention provides the following [1] to [7].

[1] A metal surface treatment agent for a galvanized steel material comprising an organic resin particle (A), a silicon oxide particle (B), a lithium silicate (C), an organic titanium compound (D), and an epoxy group- The organic resin particles (A) are resin particles obtained by modifying a base resin with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and the silanol and / or alkoxysilyl groups resin particles, and the SiO ₂ in terms of the number of moles of the total amount of the silicon element contained in the silicon oxide particles (B), and the lithium silicate (C), number of moles Li ₂ O in terms of lithium element contained in the lithium silicate (C) has (A) is 20 to 70 mass%, the amount of the silicon oxide particles (B) is 10 to 50 mass%, and the amount of the silicon oxide particles %, The lithium silicate (C) is 1 to 10% by mass, the organic titanium compound (D) is 0.05 to 5 mass% in terms of a titanium element, the epoxy group-containing compound (E) is 0.2 to 10 mass%, and the amount of the lithium silicate (C) is in the range of 0.2 to 200 by mass.

[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 the lithium silicate (C) A metal surface treatment agent for a zinc-plated steel material according to the above [1].

[3] The metal surface treatment agent for a zinc-plated steel material according to [1] or [2], wherein the niobium compound (F) is contained in an amount of 0.1 to 10 mass% with respect to the total mass of solids of the metal surface treatment agent.

[4] The zinc-plated steel sheet according to any one of [1] to [3], which comprises 0.1 to 10% by mass of the sum of the mass of the solid component of the metal surface treatment agent, Of metal surface treatment agent.

The organic resin particle (A) is obtained by reacting the silane coupling agent (A-1) in a proportion of 1 to 20 mass% based on the solid mass of the gas resin. To (4), wherein the metal surface treating agent is a metal surface treating agent for a zinc-plated steel material.

[6] The organic resin particle (A) is obtained by reacting the multifunctional epoxy group-containing compound (A-2) in a proportion of 1 to 20% by mass with respect to the solid mass of the gas resin, A metal surface treatment agent for a galvanized steel material according to any one of [1] to [5].

[7] The SiO ₂ in terms of the number of moles of the total amount of the silicon element contained in the silicon oxide particles (B), and the lithium silicate (C), for the Li ₂ O in terms of the number of moles of lithium element contained in the lithium silicate (C) A metal surface treatment agent for a galvanized steel material according to any one of [1] to [6], wherein the metal surface treatment agent is 50 to 65 times.

[8] A method for coating a zinc-plated steel material, comprising coating the surface of a zinc-plated steel material with a metal surface treatment agent for a zinc-plated steel material according to any one of [1] to [7].

[9] A coated steel obtained by the coating method of the zinc-plated steel material according to the above-mentioned [8].

According to the present invention, there is provided a metal surface treatment agent for a zinc-plated steel material improved in an inner press grease, a substrate adhesion, an inner tape peelability, a coating adhesion, a processed portion corrosion resistance, an alkali resistance and an abatement property, and a coating method using the metal surface treatment agent And a coated steel material.

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 a zinc-plated steel material of the present invention is a zinc surface-treatment agent for a zinc-plated steel material which comprises zinc (A), silicon oxide particles (B), lithium silicate (C), organic titanium compound (D), and epoxy group- (A) is a resin particle modified by a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and the silanol group and / or (B) and the silicon element contained in the lithium silicate (C) satisfy the relationship of Li ₂ < ₂ > of the lithium element contained in the lithium silicate (C) (A) is 20 to 70 mass% and the silicon oxide particle (B) is 10 to 70 mass% with respect to the total mass of the solid component of the metal surface treatment agent, By mass to 50% by mass, and the lithium silicate (C) is 1% by mass to 10% , The organic titanium compound (D) in an amount of 0.05 to 5 mass% in terms of a titanium element, the epoxy group-containing compound (E) in an amount of 0.2 to 10 mass%, the mass of the titanium element contained in the organic titanium compound (D) Wherein the ratio of the mass of the lithium silicate (C) to the total amount of the lithium silicate (C) is 0.2 to 200.

As a result, the metal surface treatment agent for zinc-plated steel of the present invention has excellent performance in any of the inner press grease, the substrate adhesion, the inner tape peelability, the paint adhesion, the processed portion corrosion resistance, the alkali resistance and the releasability.

≪ Organic resin particle (A) >

The organic resin particle (A) used in the present invention is a resin particle obtained by modifying a gas resin with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and the silanol and / Group.

The gas resin is not particularly limited, and examples thereof include a copolymer resin of an unsaturated carboxylic acid such as ethylene and acrylic acid, methacrylic acid or maleic anhydride (for example, ethylene-methacrylic acid copolymer) Dispersible acrylic resin prepared by neutralizing with an alkali metal hydroxide such as potassium hydroxide or aqueous ammonia or organic amines and dispersed in water, a compound containing an isocyanate group-containing compound and a polyol, a low molecular weight polyol, and a compound containing an active hydrogen group and a hydrophilic group And a water-dispersed polyurethane resin prepared by preparing a polyurethane prepolymer and then neutralizing the hydrophilic group with a neutralizing agent.

Examples of the organic resin particles (A) include acryl resin having a silanol group and / or an alkoxysilyl group obtained by reacting a silane coupling agent (A-1) and a multifunctional epoxy group-containing compound (A-2) Resin particles, or polyurethane resin particles having silanol groups and / or alkoxysilyl groups. Among them, an acrylic resin (A-1) obtained by reacting a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2) Particles are preferable in that they can form fine particles and can form a high-performance coating film.

For example, when the above-mentioned ethylene-methacrylic acid copolymer resin is used as a gas resin, it is preferable that an ethylene content is 90 to 70 mass% and a methacrylic acid content is 10 to 30 mass% Do.

Further, if necessary, other monomers may be contained, but the amount thereof is preferably 10 mass% or less. When the above-mentioned ethylene-methacrylic acid copolymer resin is used, it can be produced by a known method such as polymerization by a production apparatus of a high-pressure process low-density polyethylene.

The blending amount is preferably such that the gas resin is reacted at 80 mass% or more with respect to the solid content of the organic resin particles (A). More preferably 90% by mass or more.

The organic resin particles (A) have a silanol group and / or an alkoxysilyl group. With the above-mentioned functional groups, it is possible to form a film by causing a reaction with the silicon oxide particles (B) and the organic titanium compound (D), thereby improving the adhesion of the substrate and the oil resistance of the press. The alkoxysilyl group in the alkoxysilyl group is not particularly limited and includes, for example, a trimethoxysilyl group, a dimethoxysilyl group, a methoxysilyl group, a triethoxysilyl group, a diethoxysilyl group, And the like. The functional group can be obtained by reacting a silane coupling agent (A-1) or the like described later with an aqueous dispersion of the gas resin.

(Silane coupling agent (A-1))

The silane coupling agent (A-1) used in the organic resin particle (A) may be, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3 Epoxy group-containing silane compounds such as glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ - (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropylmethyl diethoxysilane,? -Aminopropyltrimethoxysilane,? -Aminopropyltriethoxysilane,? -Aminopropylethoxysilane, N- [2- Vinylbenzylamino) ethyl] -3-aminopropyltrimethoxysilane, N-phenyl- gamma -aminopropyltrimethoxy Aminosilane-containing silane compounds such as xylenes and cis-lysines,? -Mercaptopropyltrimethoxysilane,? -Mercaptopropylmethyldimethoxysilane,? -Mercaptopropyltriethoxysilane,? -Mercaptopropylmethyl Mercapto group-containing silane compounds such as diethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane,? -Methacryloxypropylmethyldimethoxysilane,? -Methacryloxypropyltrimethoxy Silane,? -Methacryloxypropylmethyldiethoxysilane,? -Methacryloxypropyltriethoxysilane, and the like, and is preferably an epoxy group-containing silane compound. These may be used alone, or two or more of them may be used in combination.

It is preferable that the silane coupling agent (A-1) is blended in a proportion of 1 to 20% by mass based on 100% by mass of the solid content of the above-mentioned gas resin. And more preferably 1 to 10% by mass. When the blending amount is 1% by mass or more, the coating formed on the surface of the steel material has good resistance to alkali, solvent resistance and paint adhesion, and when it is 20% by mass or less, the hydrophilicity of the coating becomes appropriate and the corrosion resistance becomes good. The metal surface treatment agent used in the present invention may have improved liquid stability.

(Polyfunctional epoxy group-containing compound (A-2))

Examples of the polyfunctional epoxy group-containing compound (A-2) used in the organic resin particles (A) include sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl Ether, propylene glycol diglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate, bisphenol A glycidyl ether, hydrogenated bisphenol A diglycidyl ether, and the like. These may be used alone, or two or more of them may be used in combination. When the polyfunctional epoxy group-containing compound (A-2) is used, since the affinity with the organic resin is high, the coating film may be advantageously improved in coating film adhesion when the top coat is applied to the coating film.

Here, the multifunctional epoxy group-containing compound (A-2) does not contain an epoxy group-containing silane compound.

As the blending amount, it is preferable to react the polyfunctional epoxy group-containing compound (A-2) in an amount of 1 to 20 mass% with respect to 100 mass% of the solid content of the gas resin. And more preferably 1 to 10% by mass. When the blending amount is 1% by mass or more, the coating formed on the surface of the steel material has good resistance to alkali, solvent resistance and paint adhesion, and when it is 20% by mass or less, the hydrophilicity of the coating becomes appropriate and the corrosion resistance becomes good. The metal surface treatment agent used in the present invention may have improved liquid stability.

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

The organic resin particles (A) are contained in an amount of 20 to 70 mass% with respect to the total mass of solids of the metal surface treatment agent. If it is less than 20% by mass, sufficient coating film performance, in particular, processed portion corrosion resistance can not be obtained. Further, it is within 70% by mass from the viewpoint of adjusting the balance with the content of other components and exerting the effect of the present invention well. From the same viewpoint, the content of the organic resin particle (A) is preferably 30 to 65% by mass, more preferably 40 to 60% by mass, based on the total mass of the solid matter of the metal surface treatment agent.

On the other hand, the content of the organic resin particles (A) may be calculated from the blending amount when each raw material is blended.

<Silicon oxide particles (B)>

The silicon oxide particles (B) used in the present invention preferably have a number average particle diameter of 5 to 50 nm, more preferably 5 to 20 nm, and can be suitably selected from colloidal silica and fumed silica . The number average particle diameter of the primary particles of the silicon oxide particles (B) can be determined by electron microscopic observation. Specific examples of the silicon oxide particles (B) include Snotex N, SNOWTEX C (manufactured by Nissan Chemical Industries, Ltd.), Adelite AT-20N and AT-20A (manufactured by ADEKA), Catalysts S-20L, Catalyst SA Ltd.). These may be used alone, or two or more of them may be used in combination.

The silicon oxide particles (B) are contained in an amount of 10 to 50 mass% with respect to the total mass of solid matter of the metal surface treatment agent. If it is less than 10% by mass, sufficient coating film performance, particularly, substrate adhesion and tape peeling resistance can not be obtained. Further, it is 50 mass% or less from the viewpoint of adjusting the balance with the content of the other components and exerting the effect of the present invention excellently. From the same viewpoint, the content of the silicon oxide particles (B) is preferably 15 to 45 mass%, and more preferably 20 to 40 mass% with respect to the total mass of the solid component of the metal surface treatment agent.

On the other hand, the content of the silicon oxide particles (B) may be calculated from the blending amount when each raw material is blended

&Lt; Lithium silicate (C) >

The 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 . (Li ₄ SiO ₄ (Li ₂ O 0.5 SiO ₂ : n = 0.5)), lithium metasilicate (Li ₂ SiO ₃ (Li ₂ O _{· SiO 2: n = 1)} ), ohssoyi silicate 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 7.5SiO ₂ : n = 7.5) . The lithium silicate (C) may be, for example, a hydrate thereof.

The lithium silicate (C) may be used, for example, as an aqueous solution of lithium silicate. In such a case, the solid concentration of the aqueous solution is, for example, 1 to 50 mass%, preferably 2 to 40 mass% %to be. On the other hand, lithium silicate (C) has a water solubility 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 and n is 6 to 10 Lithium silicate is insoluble in water.

Examples of such lithium silicate (C) include 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), and lithium silicate 75 (lithium silicate aqueous solution, SiO ₂ / Li ₂ O (molar ratio) = 7.5) (all manufactured by Nissan Chemical Industries Co., Ltd.). These may be used alone, or two or more of them may be used in combination.

It is believed that lithium silicate (C) forms a pseudo-crosslink by ionic crosslinking with the silicon oxide particles (B), thereby forming a coating having excellent adhesive property to the tape.

The lithium silicate (C) is contained in an amount of 1 to 10 mass% with respect to the total mass of the solid component of the metal surface treatment agent. If it is less than 1% by mass, the peelability of the tape will be poor. Further, it is 10 mass% or less from the viewpoint of adjusting the balance with the content of the other components and exerting the effects of the present invention excellently. From the same viewpoint, the content of the lithium silicate (C) is preferably from 1 to 7% by mass, more preferably from 1 to 5% by mass, based on the sum of the solid mass of the metal surface treatment agent.

On the other hand, the content of lithium silicate (C) may be calculated from the amount of each raw material to be blended.

The SiO ₂ in terms of the number of moles of the total amount of the silicon element contained in the silicon oxide particles (B), and the lithium silicate (C), for the Li ₂ O in terms of the number of moles of lithium element contained in the lithium silicate (C) 40~70 (Hereinafter, simply referred to as a SiO ₂ molar ratio to Li ₂ O of 40 to 70). If the molar ratio of SiO ₂ to Li ₂ O is less than 40, sufficient coating film performance can not be obtained, and especially alkali resistance is lowered. On the other hand, if it exceeds 70, the peeling resistance of the inner tape is poor. From the same viewpoint, the molar ratio of SiO ₂ to Li ₂ O is preferably 50 to 65, more preferably 50 to 60.

As described above, in the metal surface treatment agent for zinc-plated steel of the present invention, 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. If the mass ratio is less than 0.2, the peel resistance of the inner press grease and inner tape deteriorates. If the mass ratio exceeds 200, the alkali degreasing property is deteriorated. From the same viewpoint, the mass ratio 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, more preferably 1.5 to 17.

The metal surface treatment agent for galvanized steel according to the present invention is characterized in that 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 the lithium silicate (C) Is in the range of 0.01 to 13. When the mass ratio is within the range of 0.01 to 13, the tape peelability and alkali resistance are improved, and the inner press grease and the processed portion corrosion resistance 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 the lithium silicate (C) Is 0.1 to 13, more preferably 0.35 to 0.65.

&Lt; Organic Titanium Compound (D) >

Specific examples of the organic titanium compound (D) used in the present invention include dipropoxybis (triethanolamineate) titanium, dipropoxybis (diethanolamineate) titanium, dibutoxybis (triethanolamine (Acetyl acetonate) titanium, dibutoxybis (acetylacetonato) titanium, dihydroxybis (lactate), and the like. ), Isopropyltri (N-amidoethyl) phosphate, isopropyltriethoxysilane, isopropyltriethoxysilane, isopropyltriethoxysilane, isopropyltriethoxysilane, isopropyltriethoxysilane, Aminoethyl) titanate, and the like. These may be used alone, or two or more of them may be used in combination.

The organic titanium compound (D) is contained in an amount of 0.05 to 5% by mass based on the sum of the solid mass of the metal surface treatment agent in terms of titanium element. If it is less than 0.05% by mass, sufficient coating film performance can not be obtained. It is also within 5 mass% from the viewpoint of adjusting the balance with the content of the other components and exerting the effects of the present invention well. From the same viewpoint, the content of the organotitanium compound (D) is preferably 0.1 to 2% by mass, more preferably 0.3 to 2% by mass, based on the sum of the solid mass of the metal surface treatment agent, 1% by mass.

On the other hand, the content of the organic titanium compound (D) may be calculated from the compounding amount when each raw material is blended.

<Epoxy group-containing compound (E)>

The epoxy group-containing compound (E) to be used in the present invention is not particularly limited, but it is a polyfunctional epoxy resin, and from the viewpoint of reducing the amount of the raw material used, the epoxy group-containing compound is more preferably polyfunctional, more preferably trifunctional or more, Four-acting. From the viewpoint of adjusting the change in viscosity due to the reaction with the organic resin particles (A), and from the viewpoint of the handling property of the obtained metal treating agent, for example, it is preferably 3 to 5 action. As specific examples, for example, the aforementioned multifunctional epoxy group-containing compound (A-2) can be used as an epoxy group-containing compound.

The epoxy group-containing compound (E) improves the press resistance particularly by forming a crosslinking reaction with the organic resin particles (A) at the time of film formation to form a high-crosslink coating.

The epoxy group-containing compound (E) is contained in an amount of 0.2 to 10 mass% with respect to the total mass of solid matter of the metal surface treatment agent. If it is less than 0.2% by mass, sufficient coating film performance, particularly sufficient press lubricity, can not be obtained. Further, it is 10 mass% or less from the viewpoint of adjusting the balance with the content of the other components and exerting the effects of the present invention excellently. 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 component of the metal surface treatment agent.

On the other hand, the content of the epoxy group-containing compound (E) may be calculated from the compounding amount when each raw material is blended.

&Lt; Niobium compound (F) >

The metal surface treatment agent for zinc-plated steel of the present invention preferably further contains an niobium compound (F) in addition to the above (A) to (E).

The niobium compound (F) is contained preferably in an amount of 0.1 to 10 mass% with respect to the total mass of the solid component of the metal surface treatment agent. If it is within the range of 0.1 to 10 mass%, the corrosion resistance at the processed portion is excellent. From the same viewpoint, the content of the niobium compound (F) is more preferably 0.2 to 5% by mass, and more preferably 0.5 to 2% by mass, based on the sum of the solid masses of the metal surface treatment agent.

The niobium compound (F) is not particularly limited, and conventionally known niobium-containing compounds can be used. Examples thereof include niobium oxide, niobic acid and salts thereof, fluoroniobates, Oxalate, and the like. Among them, niobium oxide is preferable from the viewpoint of improvement of corrosion resistance.

The niobium oxide is preferably niobium oxide particles. As a result, it is possible to form a composite film of niobium oxide particles, and the corrosion resistance can be further improved.

The niobium oxide particle refers to an oxide of niobium dispersed in the form of particles in water. For example, niobium oxide is not strictly formed, but an intermediate state between niobium hydroxide and niobium oxide, Or may be in a state that is in a state.

As the niobium oxide particles to be added to the metal surface treatment agent used for forming the coating film, niobium oxide particles produced by a known method can be used. The niobium oxide particle is not particularly limited, and examples of the niobium oxide particle include, for example, those disclosed in Japanese Patent Application Laid-Open Nos. 6-321543, 8-143314, 8-325018, And the like. It is also possible to use niobium oxide or a niobium oxide slurry commercially available from DAKI Chemical.

The average particle diameter of the niobium oxide particles is preferably 2 nm to 10 m, more preferably 2 nm to 1 m. It is more preferable that the average particle diameter is smaller, since a coating comprising more stably dense niobium oxide is formed, so that rustproofing property can be imparted stably to the object to be treated. The average particle size of the niobium oxide particles can be determined as a volume average particle size, which is 50% of the cumulative volume by using a laser diffraction / scattering type microtrack HRA particle size distribution meter (manufactured by Honeywell).

<Phosphoric acid compound (G)>

The metal surface treatment agent for zinc plated steel of the present invention preferably further contains a phosphoric acid compound (G) in addition to the above (A) to (E) or the above (A) to (F). Examples of the phosphoric acid compound (G) include phosphoric acids such as orthophosphoric acid, metaphosphoric acid, pyrophosphoric acid, trisphosphoric acid and triphosphoric acid, triammonium phosphate, ammonium hydrogenphosphate, trisphosphate and disodium hydrogenphosphate have. These may be used alone, or two or more of them may be used in combination.

When the phosphate compound (G) is used, phosphate ions can passivate by forming a phosphate layer on the surface of the metal base, thereby improving the corrosion resistance.

The phosphoric acid compound (G) is contained in an amount of preferably 0.1 to 10% by mass based on the sum of the solid mass of the metal surface treatment agent in terms of phosphorus element. The content is in the range of 0.1 to 10 mass%, and therefore, the corrosion resistance at the processed portion is excellent. From the same viewpoint, the content of the phosphate compound (G) is preferably 0.2 to 5% by mass, more preferably 0.5 to 2% by mass, based on the total of the solid mass of the metal surface treatment agent, Mass%.

On the other hand, the content of the phosphate compound (G) may be calculated from the amount of each raw material to be compounded.

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

<Water>

The metal surface treatment agent for zinc plated steel of the present invention may further contain water in addition to the above (A) to (E), (A) to (F) or (A) to (G).

&Lt; Other components >

The metal surface treatment agent for zinc-plated steel of the present invention may contain other components in addition to the above (A) to (G) and water. For example, wax, a lubricant, and a pigment may be blended. As the wax, for example, conventionally known waxes such as hydrocarbon waxes such as paraffin, microcrystalline and polyolefin, and derivatives thereof can be used. Examples of the derivative include a carboxylated polyolefin and a chlorinated polyolefin. As the lubricant, conventionally known lubricants such as fluorine, hydrocarbon, fatty acid amide, ester, alcohol, metal soap, and inorganic lubricants 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, (Fe ₂ O ₃ , Fe ₃ O ₄ ), and various coloring pigments such as organic pigments. As the rust inhibitor, for example, a thiocarbonyl compound or a guanidine compound described in Japanese Patent No. 492295 can be used.

(Manufacturing method of metal surface treatment agent for zinc-plated steel material)

The metal surface treatment agent for a zinc-plated steel material of the present invention is characterized in that the above-mentioned metal oxide surface treatment agent is added to an aqueous dispersion in which resin particles of the organic resin particles (A) are dispersed, the silicon oxide particles (B), the lithium silicate (C) (F), the phosphoric acid compound (G), water, and other components, if necessary, in combination with the epoxy group-containing compound (E) Can be produced by blending at least one of them.

[Coating method of galvanized steel]

The method for coating a galvanized steel sheet of the present invention is characterized in that the surface of a galvanized steel sheet is coated with a metal surface treatment agent for a galvanized steel sheet of the present invention to form a coating. As a result, the coating method of the zinc-plated steel sheet of the present invention has excellent performance in both of the inner press grease, the substrate adhesion, the inner tape peelability, the coating adhesion, the processed portion corrosion resistance, the alkali resistance, and the releasability.

The coating is a state in which the organic resin particles (A), the silicon oxide particles (B), the organic titanium compound (D) and the epoxy group-containing compound (E) are bonded to each other. That is, the functional group of the organic resin particle (A), the functional group of the surface of the silicon oxide particle (B), the organic titanium compound (D) and the functional group of the epoxy group containing compound (E)

It is considered that in the film, pseudo-crosslinking is formed by ionic crosslinking between the silicon oxide particles (B) and lithium silicate (C).

The bonding is mainly carried out in the presence of a Ti-OR 'group (Si) of the organic resin particle (A) and / or a Si-OH group on the surface of the Si- Si-O-Si bond, Si-O-Ti-O-Si bond, and the like. By these bonds, an advantageous effect that the organic resin particles and the inorganic particles form a chemically strong bond is obtained. Further, it is considered that a stronger coating is formed by crosslinking the epoxy group of the epoxy group-containing compound (E) with the carboxylic acid group of the organic resin particle (A), and the press resistance and the like are improved. Here, R is a substituent derived from the silane coupling agent (A-1) described above, and R 'is a substituent derived from the above-mentioned organic titanium compound (D).

In addition, as described above, it is considered that the coating of silicon nitride (B) and the lithium silicate (C) forms a crosslinked structure by ionic crosslinking, thereby forming a coating having excellent adhesive property to the tape.

Since the particle diameter of the organic resin particle (A) is within a specific range, the above-mentioned inter-particle bonding is formed at a high density, so that the film is chemically stable and microscopically homogeneous. Therefore, it is presumed that the metal surface treating agent for zinc-plated steel of the present invention can obtain a remarkable effect.

In the preparation of the metal surface treatment agent for coating the zinc-plated steel material, the order of addition of the respective components is not particularly limited, but for example, the above-mentioned method for producing the metal surface treatment agent for zinc-plated steel material can be used.

As the metal surface treatment agent for the galvanized steel, a solvent or a leveling agent may be used in order to form a more uniform and smooth film. The solvent and leveling agent are not particularly limited as long as they are generally used in paints, and examples thereof include alcohol-based, ketone-based, ester-based and ether-based hydrophilic solvents and silicone leveling agents.

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 the zinc-coated steel or the non-coated steel, the metal surface treatment agent is applied to a degreased base material (coating object), if necessary. The coating method is not particularly limited, and commonly used roll coating, air spraying, airless spraying, dipping and the like can be suitably employed. In order to enhance the hardenability of the coating film, it is preferable to heat the coating material in advance or to heat-dry the coating material after coating. The steel sheet reaching temperature (PMT), which is an index of the heating temperature of the substrate, is preferably 20 to 250 캜, more preferably 50 to 220 캜. If the heating temperature is 50 占 폚 or higher, the evaporation rate of water is high and sufficient film-forming property can be obtained, thereby improving the solvent resistance and alkali resistance. On the other hand, when the temperature is lower than 250 占 폚, thermal decomposition of the resin is less likely to occur, and the solvent resistance and alkali resistance are improved, and deterioration of appearance due to yellowing can be suppressed.

In addition, the metal surface treatment agent for zinc-plated steel of the present invention can form a film having sufficiently excellent performance by evaporating and drying the water even under a low temperature condition at room temperature (20 캜).

The drying time in the case of thermal drying after coating is preferably 1 second to 5 minutes.

[Coated steel]

The coated steel of the present invention is obtained by coating a steel material with a metal surface treatment agent for a galvanized steel material of the present invention. Further, it is obtained by a coating method of a zinc-plated steel material characterized by coating a metal surface treatment agent for a zinc-plated steel material of the present invention on the surface of a zinc-plated steel material to form a film. As a result, the coated steel of the present invention has excellent performance in either of the inner press grease, the substrate adhesion, the inner tape peelability, the coating adhesion, the processed portion corrosion resistance, the alkali resistance and the releasability.

In the coated steel, the coating amount is preferably 0.1 to 3 g / m ² , more preferably 0.5 to 1.5 g / m ² . When the coating amount is 0.1 g / m ² or more, the corrosion resistance is improved. When the coating amount is 3 g / m ² or less, deterioration of the substrate adhesion can be suppressed.

Further, the coated steel of the present invention may be used by forming a coating film by applying an upper coating on the coating. Examples of the top coat include paints composed of an acrylic resin, an acrylic modified alkyd resin, an epoxy resin, a urethane resin, a melamine resin, a phthalic acid resin, an amino resin, a polyester resin, a vinyl chloride resin and the like.

The thickness of the coating film of the top coat is appropriately determined depending on the use of the antirust metal product, the type of the top coat used, and the like, and is not particularly limited. And is usually from 5 to 300 mu m, and more preferably from 10 to 200 mu m. The coating film of the top coat can be formed by applying the top coat onto the coating film formed by the metal surface treatment agent for the galvanized steel material, and drying and curing by heating. The drying temperature and time are appropriately adjusted depending on the type of the top coat to be applied and the film thickness of the coated film, but usually the drying temperature is preferably 50 to 250 DEG C, and the drying time is preferably 5 minutes to 1 hour . The top coat may be applied by a conventionally known method depending on the type of the coating.

Examples of the steel used in the present invention include zinc-plated steel, zinc-nickel plated steel, zinc-iron plated steel, zinc-chromium plated steel, zinc-aluminum plated steel, zinc- Zinc-aluminum-magnesium plated steel, zinc-aluminum-magnesium-silicon plated steel, and the like, and further to these plating layers a small amount of dissimilar metal elements or impurities such as cobalt, molybdenum And the like, inorganic materials such as silica, alumina, titania and the like, which are dispersed in an organic solvent such as water, . Further, the present invention can be applied to the plating of two or more layers in combination with the above plating and other kinds of plating, for example, iron plating, iron-phosphor plating, nickel plating, cobalt plating and the like. Further, it is adaptable to aluminum or aluminum-based alloy plating. The plating method is not particularly limited, and may be any known electroplating method, hot dip coating method, vapor deposition plating method, dispersion plating method, or vacuum plating method.

Example

Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples. On the other hand, in the following description, unless otherwise stated, the percentages of the percentages denote% by mass.

&Lt; Preparation Example 1 &

(Production of Resin Particle (a-1)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. 0.69% of hydrogenated bisphenol A diglycidyl ether (product name: SR-HBA, manufactured by Sakamoto Chemical Industries, Ltd.) and 0.69% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (A-1) having a silanol group and / or a methoxysilyl group with a solid content of 24% was prepared by adding 1.15% of a polyvinyl alcohol resin (trade name: KBM-303 manufactured by Shin-Etsu Chemical Co., Aqueous dispersion. The average particle size of the resin particle (a-1) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Preparation Example 2 &

(Production of Resin Particle (a-2)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. To the aqueous dispersion resin solution, 0.69% of hydrogenated bisphenol A diglycidyl ether and 0.29% of 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane were added, and the reaction was carried out at 85 ° C for 2 hours To obtain an aqueous dispersion of the resin particles (a-2) having a solid content of 24% and having a silanol group and / or a methoxysilyl group. The average particle size of the resin particles (a-2) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Preparation Example 3 &

(Production of Resin Particle (a-3)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. To the aqueous dispersion resin solution, 0.69% of hydrogenated bisphenol A diglycidyl ether and 5.75% of 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane were added, and the reaction was carried out at 85 ° C for 2 hours To obtain an aqueous dispersion of resin particles (a-3) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle diameter of the resin particles (a-3) measured by FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) by a dynamic light scattering method was 70 nm.

&Lt; Preparation Example 4 &

(Production of Resin Particle (a-4)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. 0.23% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane were further added to this water dispersion resin solution, and the reaction was carried out at 85 ° C for 2 hours To obtain an aqueous dispersion of resin particles (a-4) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle diameter of the resin particles (a-4) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Production Example 5 &

(Production of Resin Particle (a-5)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. 4.6% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyl trimethoxysilane were further added to this water dispersion resin solution, and the reaction was carried out at 85 ° C for 2 hours To obtain an aqueous dispersion of resin particles (a-5) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle diameter of the resin particle (a-5) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Production Example 6 &

(Production of Resin Particle (a-6)) [

To the reaction vessel were added 0.90% hydrogenated bisphenol A diglycidyl ether and 2- (3,4-epoxy (meth) acrylate) to an aqueous urethane resin (product name: Adekabon Tita HUX-320, (A-6) having a silanol group and / or a methoxysilyl group at a solid content of 24% was obtained by adding 1.50% of a silyl group-containing ethylenically unsaturated compound . The average particle size of the resin particles (a-6) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Production Example 7 >

(Production of Resin Particle (a-7)

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. 0.69% of hydrogenated bisphenol A diglycidyl ether and 1.15% of? -Glycidoxypropyltrimethoxysilane (product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to this water dispersion resin solution to obtain 85 C for 2 hours to obtain an aqueous dispersion liquid of resin particles (a-7) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle size of the resin particles (a-7) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Production Example 8 &

(Production of Resin Particle (a-8)) [

Ethylene-methacrylic acid copolymer resin (ethylene content: 80%, methacrylic acid content: 20%), 5.6% sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 DEG C for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. 0.69% of sorbitol polyglycidyl ether (product name: Denacol EX-614B, manufactured by Nagase ChemteX) and 0.69% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane %, And the mixture was allowed to react at 85 占 폚 for 2 hours to obtain an aqueous dispersion of resin particles (a-8) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle diameter of the resin particles (a-8) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By the dynamic light scattering method was 70 nm.

&Lt; Production Example 9 &

(Production of Resin Particle (b)) [

Ethylene-methacrylic acid copolymer resin (80% of ethylene and 20% of methacrylic acid), 4.6% of sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 占 폚 for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. To the aqueous dispersion resin solution, 0.69% of hydrogenated bisphenol A diglycidyl ether and 1.15% of 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane were added, and the reaction was carried out at 85 ° C for 2 hours To obtain an aqueous dispersion of resin particles (b) having a solid content of 24% and having silanol groups and / or methoxysilyl groups. The average particle diameter of the resin particles (b) measured by FPAR-1000 (manufactured by OTSUKA ELECTRONICS CO., LTD.) By a dynamic light scattering method was 100 nm.

&Lt; Production Example 10 &

(Production of Resin Particle (c)) [

Ethylene-methacrylic acid copolymer resin (80% of ethylene and 20% of methacrylic acid), 4.6% of sodium hydroxide and deionized water were added to the reaction vessel and stirred at 95 占 폚 for 6 hours To obtain a water dispersion resin liquid having a solid content of 23%. An aqueous dispersion of the resin particles (c) having a solid content of 24% was obtained by adding 0.69% hydrogenated bisphenol A diglycidyl ether to the aqueous dispersion resin solution and allowing the reaction to proceed at 85 캜 for 2 hours. In Production Example 10, no silane coupling agent was added. The average particle diameter of the resin particles (c) measured by FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.) by the dynamic light scattering method was 110 nm.

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

In the following Examples 1 to 32 and Comparative Examples 1 to 23, the following raw materials and materials were used, and a metal surface treatment agent was prepared using water as a solvent.

Silicon oxide particles; Product name AT-20A, manufactured by ADEKA, average particle diameter 12 nm

Lithium silicate; Product name Lithium silicate 35, manufactured by Nippon Chemical Industry Co., Ltd.

Organic titanium compounds; Product name T-50, dipropoxy bis (acetylacetonato) titanium, manufactured by Nippon Soda Co.,

An epoxy group-containing compound; Product name SR-HBA, manufactured by Sakamoto Pharmaceutical Co., Ltd.

Niobium compounds; Product name: Bayer Nb-G6000, manufactured by Dakiki Chemical Co., Ltd., average particle diameter 15 nm

Phosphate compounds; Ingredient Trisodium phosphate (anhydrous)

Other raw materials; (Manufactured by Nippon Synthetic Industries Co., Ltd.), WAX (product name: Hi-Tech E-6000S, manufactured by Toho Chemical Industry Co., Ltd., trade name; manufactured by Nippon Synthetic Chemicals Co., Ltd.), melamine resin (product name: Cymeel 385, Purge)

(galvanized steel)

NS gal coat (registered trademark) "(hereinafter referred to as EG), hot-dip galvanized steel sheet" NS Silver zinc (registered trademark) "(hereinafter referred to as" GI ") manufactured by Shin-Nittsu Kabushiki- (Hereinafter referred to as SD), a zinc-aluminum-magnesium alloy-silicon alloy-plated steel sheet manufactured by Shin-Nittsu Kabushiki Kaisha (hereinafter referred to as SD) (Hereinafter referred to as "ZL") manufactured by Nippon Steel Chemical Co., Ltd. (hereinafter referred to as "GL"), zinc-nickel alloy coated steel sheet "NS Zinkite (registered trademark)" The aluminum-magnesium alloy coated steel sheet "ZAM (registered trademark)" was used as the original plate. The plate thickness of the original plate was 0.6 mm. The EG used was one having a plating amount of 20 g / m ^{2 on one} side. Further, GI, SD, GL, and ZAM were used in which the plating adhesion amount was 60 g / m ^{2 on one} side. The plating amount of ZL was 20 g / m ² on one side, and the amount of nickel in the plating layer was 12 mass%.

&Lt; Example 1 >

(Preparation of metal surface treatment agent for galvanized steel)

(B), lithium silicate (C), an organic titanium compound (D), an epoxy group containing compound (E), a niobium compound (F) and a phosphoric acid compound (D) are added to an aqueous dispersion of the resin particle (a- G) was formulated according to the prescription described in Table 2 to prepare a metal surface treatment agent for galvanized steel.

(Preparation of trial version)

Each galvanized steel sheet was spray-treated at 60 DEG C for 2 minutes by using a 2% aqueous solution of an alkaline degreasing agent (Surf Cleaner 155, manufactured by Nippon Paint Co., Ltd.), degreased, washed with water and dried by hot air. After cooling, the metal surface treatment agent was coated on the degreasing treatment plate so that the amount of the dried coating was 1 g / m ² with a bar coater, and the steel sheet reached a temperature (PMT) of 150 ° C By using a hot-air drying furnace having an atmospheric temperature of 200 캜 so as to have a steel sheet reaching temperature (PMT) of 50 캜.

&Lt; Examples 2 to 32 and Comparative Examples 1 to 23 >

A metal surface treatment agent for a zinc-plated steel material was prepared and a test plate was prepared in the same manner as in Example 1, using the combination of the metal surface treatment agent for zinc-plated steel materials, the mixing conditions, and the preparation conditions of the test plate described in Tables 2 and 3.

[Assessment Methods]

The test plates of Examples 1 to 32 and Comparative Examples 1 to 23 produced as described above were subjected to the following evaluations. The evaluation results are shown in Tables 2 and 3.

<My Press Meteor>

After immersion for 24 hours under room temperature to maintain a pre-press (G6318SK, Nippon Tool like agents), cleaning the test plate with hexane, and then installed in the rubbing tester, using an absorbent cotton impregnated with ethanol, of 0.5kgf / cm ² The state of the film after 10 rounds of rubbing with a load was evaluated by the following evaluation criteria.

A: No friction marks on the friction surface

B: Traces of friction are slightly formed on the friction surface

C: White friction marks on the friction surface

D: Part of the friction surface is peeled off

&Lt; Substrate adhesion property &

A test plate of 1 hour or less after coating was extruded 8 mm from Eric's tester, and then Cellotape (registered trademark) (Nichia's reflective agent) was attached to the extruded portion and forcedly peeled off. The peeled test plate was immersed in a methyl violet dyeing solution for 30 minutes, and the state of the film was evaluated by the following evaluation criteria.

A: Almost no peeling

B: Peeled area less than 10%

C: Peel area 10% or more and less than 25%

D: Peeling area 25% or more

&Lt; Tape peelability &

A filament tape (manufactured by Hitachi Maxell) was attached to the test plate, and the tape was allowed to stand for 2 weeks under conditions of 40 캜 and 80% humidity, 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 tape marks remain

C: Peel area less than 50%

D: Peel area of 50% or more

&Lt; Coating adhesion &

A melamine alkyd paint (trade name: Olga Neo 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 thickness of 20 μm and baked at 130 ° C for 15 minutes to prepare a coated plate. Next, the coated plate was immersed in boiling water for 30 minutes, taken out, left for 24 hours, extruded 7 mm from the coated plate in Eric's tester, Cellotape (registered trademark) (Nichia reflector) was attached to the extruded part, The state of the film after forced release was evaluated by the following evaluation criteria.

A: Almost no peeling

B: Peeled area less than 10%

C: Peel area 10% or more and less than 25%

D: Peeling area 25% or more

&Lt; Corrosion resistance of machined portion &

The test plate was extruded 7 mm from Eric's tester, and the edge and back of the test plate were tape-sealed and subjected to a salt water spray test (SST) (JIS-Z-2371). The occurrence of white rust after 72 hours was observed and evaluated according to the following criteria.

A: No white rust

B: Less than 10% white rust occurrence area

C: White rust occurrence area is 10% or more and less than 30%

D: 30% or more of white rust occurrence area

<Alkali resistance>

The test plate was immersed in a 2% by mass aqueous solution (pH 12.5) of an alkaline degreasing agent (Surf Cleaner 155, manufactured by Nippon Paint Co., Ltd.) at 60 ° C for 2 minutes while stirring. The edge and back surface of the test piece were tape- -2371). The occurrence of white rust occurrence after 72 hours was observed and evaluated according to the following criteria.

A: No white rust

B: Less than 10% white rust occurrence area

C: White rust occurrence area is 10% or more and less than 30%

D: 30% or more of white rust occurrence area

<Abbreviation>

A load of 10 g / cm &lt; ² &gt; was applied to a test plate through a corrugated cardboard, and an elliptical motion of 360 revolutions / min was applied to generate abrasion (abrasion scratches) on the sliding portion. The state of the test plate surface after the test for 10 minutes was observed, and evaluated according to the following criteria.

A: Almost no blackening

B: Less than 10% of the sliding area is blackened

C: An area of 10% or more and less than 30% of the sliding part is blackened

D: More than 30% of the sliding area is blackened

As shown in Table 2 and Table 3, from the comparison between Examples 1 to 26 and Comparative Examples 1 to 19, the metal surface treatment agent for zinc-plated steel of the present invention is superior in resistance to oil press, oil resistance, Excellent effects were confirmed in any of adhesion, corrosion resistance, alkali resistance, and releasability.

By using the metal surface treatment agent for zinc-plated steel material of the present invention, the coating method using the metal surface treatment agent, and the coated steel material, it is possible to provide an inner press grease, substrate adhesion, inner tape peelability, paint adhesion, It was confirmed that excellent performance was exhibited in any of the bronzing properties.

The metal surface treatment agent for a zinc-plated steel material of 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 materials, and the like.

Claims (9)

A metal surface treatment agent for a zinc-plated steel material comprising an organic resin particle (A), a silicon oxide particle (B), a lithium silicate (C), an organic titanium compound (D), and an epoxy group-
The organic resin particle (A) is a resin particle obtained by modifying a base resin with a silane coupling agent (A-1) and a polyfunctional epoxy group-containing compound (A-2), and is a silanol and / or alkoxysilyl Wherein the molar ratio of the total amount of the silicon element contained in the silicon oxide particles (B) and the lithium silicate (C) to the SiO _{2 in} terms of SiO ₂ is less than or equal to the Li ₂ O-converted amount of the lithium element contained in the lithium silicate (C) 40-70 times the number of moles,
The total mass of the solid component of the metal surface treatment agent,
Wherein the organic resin particles (A) have a solid content of 20 to 70 mass%
Wherein the silicon oxide particles (B) are contained in an amount of 10 to 50 mass%
The lithium silicate (C) is contained in an amount of 1 to 10 mass%
Wherein the organic titanium compound (D) is 0.05 to 5% by mass in terms of titanium element,
, The amount of the epoxy group-containing compound (E) is 0.2 to 10%
Wherein 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 method according to claim 1,
Wherein 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 the lithium silicate (C) is 0.01 to 13, Surface treatment agent. 3. The method according to claim 1 or 2,
A metal surface treatment agent for zinc-plated steel products, comprising a niobium compound (F) in an amount of 0.1 to 10 mass% with respect to a total mass of solids of the metal surface treatment agent. 4. The method according to any one of claims 1 to 3,
A metal surface treatment agent for a zinc-plated steel material, wherein the phosphoric acid compound (G) is contained in an amount of 0.1 to 10% by mass relative to the sum of the solid mass of the metal surface treatment agent in terms of phosphorus. 5. The method according to any one of claims 1 to 4,
Wherein the organic resin particles (A) are obtained by reacting a silane coupling agent (A-1) in a proportion of 1 to 20 mass% based on the solid mass of the gas resin and reacting. Treatment agent. 6. The method according to any one of claims 1 to 5,
Wherein the organic resin particles (A) are obtained by reacting a polyfunctional epoxy group-containing compound (A-2) in a proportion of 1 to 20% by mass with respect to the solid mass of the gas resin, Surface treatment agent. 7. The method according to any one of claims 1 to 6,
The SiO ₂ in terms of the number of moles of the total amount of the silicon element contained in the silicon oxide particles (B), and the lithium silicate (C), for the Li ₂ O in terms of the number of moles of lithium element contained in the lithium silicate (C) 50~65 Metal surface treatment agent for copper plating and galvanized steel. A method for coating a zinc-plated steel material, comprising coating the surface of a zinc-plated steel material with a metal surface treatment agent for zinc-plated steel according to any one of claims 1 to 7 to form a film. A coated steel obtained by the coating method of the zinc-plated steel material according to claim 8.