WO2018074195A1 - Aqueous metal surface treatment agent, metal surface treatment method, and surface-treated metal sheet - Google Patents

Abstract

The present invention relates to an aqueous metal surface treatment agent containing amino group-containing acrylic resin particles (A), which have a core-shell structure and the amine value is 14–72 mg KOH/g, and a phosphate compound (B), wherein the aqueous metal surface treatment agent contains 0.5–1.0 mass% of the phosphate compound (B) with respect to the total amount of solids of the amino group-containing acrylic resin particles (A).

Description

Aqueous metal surface treatment agent, metal surface treatment method and surface treated metal plate

The present invention relates to an aqueous metal surface treatment agent not containing a chromium compound, a metal surface treatment method using the aqueous metal surface treatment composition, and the aqueous metal surface treatment assembly, which replaces the conventional chromate treatment and phosphate treatment. The present invention relates to a surface-treated metal plate using an agent.

Conventionally, chromate treatment and phosphate treatment are generally performed to improve the corrosion resistance of metal surfaces. However, the toxicity of chromium has become a social problem in recent years. The surface treatment method using chromate has a problem of scattering of chromate fume in the treatment process, a problem that requires a large amount of cost for wastewater treatment equipment, and a problem due to elution of chromic acid from the chemical conversion treatment film. is there.

In addition, in phosphate treatment, zinc phosphate-based and iron phosphate-based surface treatments are usually performed, but for the purpose of imparting corrosion resistance, after phosphating, usually rinsing treatment with chromic acid, There is a problem with chrome treatment. In addition, since the metal surface is etched, there are problems such as wastewater treatment of metal ions and sludge treatment due to elution of metal ions from the metal to be treated.

As a treatment method other than the chromate treatment and the zinc phosphate treatment, for example, Patent Document 1 discloses that zinc treated steel is treated with an aqueous solution containing aluminum biphosphate and then heated at a temperature of 150 to 550 ° C. A surface treatment method for a plated steel material is disclosed, and Patent Document 2 discloses a method for treating a galvanized steel material with an aqueous solution containing tannic acid.

In Patent Document 3, as a zinc-based plated steel sheet having a surface treatment film of a thin film with a film thickness of several μm or less, a zinc-based plated steel sheet is used as a base material, a chromate film is formed thereon, and an organic layer is formed thereon as an uppermost layer. A rust-proof steel sheet for cationic electrodeposition coating having a composite silicate film is disclosed, and this rust-proof steel sheet has excellent workability and corrosion resistance.

In Patent Document 4, a zinc-based or aluminum-based plated steel sheet is surface-treated using a surface treatment liquid containing a cationic urethane resin, a specific phenol resin, a silane coupling agent, a titanium compound, and a specific acid or salt thereof. A surface-treated steel sheet is disclosed.

Patent Document 5 discloses a metal surface treatment agent comprising a cationic acrylic resin, a resin compound represented by a specific formula, and a compound of Zr, Ti, V, Mo, W, Mn, or Ce mixed in water. Further, a metal surface treating agent is disclosed in which the metal is selected from a steel plate, a plated steel plate, and an aluminum-based metal material.

Patent Document 6 includes an acrylic resin that is water-soluble, water-dispersible, or emulsion-based, and includes at least one of an amino group or an ammonium group, a hydroxyl group, and a hydrophobic group, and a heavy metal or a salt thereof. An acrylic resin-containing metal surface treatment composition characterized by containing is disclosed.

Patent Document 7 discloses a metal that is water-soluble, water-dispersible, or emulsion-based, and contains an organic polymer compound or a salt thereof containing at least one nitrogen atom and a heavy metal or a salt thereof. A surface treatment composition is disclosed.

Japanese Patent Publication No. 53-28857 Japanese Unexamined Patent Publication No. 51-71233 Japanese Unexamined Patent Publication No. 60-50180 Japanese Unexamined Patent Publication No. 2003-105562 Japanese Unexamined Patent Publication No. 2008-163462 Japanese Unexamined Patent Publication No. 11-106939 Japanese Laid-Open Patent Publication No. 9-25436

However, in the method described in Patent Document 1, when a paint is applied on a galvanized steel material, the adhesion of the paint is not sufficient, and the method described in Patent Document 2 has a problem that the corrosion resistance is inferior.

Since the rust-proof steel sheet described in Patent Document 3 has a chromate film, there is a problem of health and safety due to chromate ions. Moreover, in the steel plate obtained by removing the chromate film from the rust-proof steel plate, the corrosion resistance is greatly reduced.

In the surface-treated steel sheet described in Patent Document 4, the performance balance of characteristics such as corrosion resistance such as flat portion corrosion resistance, corrosion resistance after alkali degreasing, and processed portion corrosion resistance, water resistance, topcoat adhesion, and acid resistance was not always good.

The metal surface treatment agent described in Patent Document 5 and the metal surface treatment compositions described in Patent Documents 6 and 7 have a problem that the corrosion resistance, particularly the corrosion resistance after processing of the metal-treated plate is insufficient.

In other words, the chromium-free surface-treated metal plates proposed so far are more resistant to corrosion than conventional surface-treated metal plates in which an organic resin is coated on the chromate film, in particular, after processing the surface-treated metal plate. Performance balance regarding required properties such as safety and chemical resistance was not sufficient.

An object of the present invention is to provide an aqueous metal surface treatment agent that can form a surface-treated metal plate that is excellent in water resistance, discoloration resistance, corrosion resistance, ethanol rubbing resistance, and abrasion resistance, and that can satisfy corrosion resistance after Erichsen processing. That is.

Another object of the present invention is to provide a surface-treated metal plate using the aqueous metal surface treatment agent and a metal surface treatment method using the aqueous metal surface treatment agent.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using the amino group-containing acrylic resin particles (A) and the phosphoric acid compound (B), and have completed the present invention. It was.
That is, the present invention relates to the following <1> to <11>.

<1> An aqueous metal surface treatment agent comprising an amino group-containing acrylic resin particle (A) having a core-shell structure and an amine value of 14 to 72 mgKOH / g, and a phosphoric acid compound (B), An aqueous metal surface treatment agent containing 0.5 to 10% by mass of the phosphoric acid compound (B) based on the total solid content of the amino group-containing acrylic resin particles (A).
<2> The aqueous metal surface treatment agent according to <1>, further comprising at least one of a fluorometal acid and a salt thereof (C).
<3> The aqueous metal surface treatment agent according to <1> or <2>, further containing a vanadium compound (D).
<4> The aqueous metal surface treatment agent according to any one of <1> to <3>, further containing at least one of a silane coupling agent and a hydrolysis-condensation product thereof (E).
<5> The aqueous metal surface treatment agent according to any one of <1> to <4>, further comprising a polyolefin wax (F) having an average particle size of 0.1 to 3 μm.
<6> The phosphoric acid compound (B) is at least one compound selected from the group consisting of orthophosphoric acid, hydroxymethane diphosphonic acid and 1-hydroxyethane-1,1-diphosphonic acid. The aqueous metal surface treating agent according to any one of <5>.
<7> The aqueous metal surface treatment agent according to any one of <2> to <6>, wherein the metal of at least one of the fluorometal acid and its salt (C) is titanium or zirconium.
<8> Any one of <3> to <7>, wherein the vanadium compound (D) is at least one compound selected from the group consisting of ammonium metavanadate, sodium metavanadate, potassium metavanadate, and vanadyl sulfate. The aqueous metal surface treatment agent according to 1.
<9> The aqueous metal surface treatment agent according to any one of <1> to <8>, wherein the pH is 3 to 7, and the solid content concentration is 5 to 30% by mass.
<10> A metal surface treatment method in which the aqueous metal surface treatment agent according to any one of <1> to <9> is applied onto a metal substrate and dried.
<11> A surface-treated metal sheet, wherein the surface of the metal substrate is subjected to a surface treatment with the aqueous metal surface treatment agent according to any one of <1> to <9>.

According to the aqueous metal surface treatment agent of the present invention, it is an aqueous metal surface treatment agent that does not contain a chromium compound, but is excellent in water resistance, discoloration resistance, corrosion resistance, ethanol rubbing resistance and abrasion resistance, and after Erichsen processing. It is possible to obtain a surface-treated metal sheet on which a surface-treated film that satisfies the above corrosion resistance is formed.

Therefore, the aqueous metal surface treatment agent of the present invention and the surface-treated metal plate that has been surface-treated with this treatment agent can overcome environmental problems and satisfy the above-mentioned performances. Have

Each component in the aqueous metal surface treating agent of the present invention will be described below, but these are examples of desirable embodiments and are not limited to these contents.
In the present specification, “mass” is synonymous with “weight”.
In the present specification, “X and / or Y” means “at least one of X and Y”.

[Amino group-containing acrylic resin particles (A)]
The aqueous metal surface treatment agent of the present invention contains amino group-containing acrylic resin particles (A). The amino group-containing acrylic resin particles (A) have a core-shell structure with a core portion as a central portion and a shell portion as an outer shell portion, and the core portion and the shell portion are obtained from monomer mixtures having different compositions.
The core-shell structure specifically refers to a structure in which components having different resin compositions exist in the same micelle and the resin composition is different between the central portion (core) and the outer shell portion (shell).

The core-shell structure is generally a layer structure in which the core part is completely covered by the shell part, but the shell part forms a layer structure depending on the mass ratio of the core part to the shell part, other conditions, and the like. It may be insufficient for this. In such a case, it is not necessary to have a complete layer structure as described above, and a structure in which a shell part covers a part of the core part may be used.

From the viewpoint of dispersion stability, the composition ratio of the core part to the shell part is preferably set to core part: shell part = 90: 10 to 10:90 (mass ratio), more preferably 70:30 to 20: 80, more preferably 70:30 to 30:70.

If the core ratio in the amino group-containing acrylic resin particles (A) is less than 10% by mass, the corrosion resistance may decrease. Moreover, since dispersion stability will fall when a core part ratio exceeds 90 mass%, the dispersibility of an amino-group-containing acrylic resin particle (A) may fall.

Both the monomer mixture used for the polymerization of the core part and the shell part contains a polymerizable unsaturated monomer. The core part and the shell part are preferably obtained by polymerizing polymerizable unsaturated monomers using monomer mixtures having different types and / or blending ratios.

Examples of the polymerizable unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, and i-butyl. (Meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (Meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, Alkyl or cycloalkyl (meth) acrylates such as clododecyl (meth) acrylate and tricyclodecanyl (meth) acrylate; polymerizable unsaturated monomers having an isobornyl group such as isobornyl (meth) acrylate; adamantyl such as adamantyl (meth) acrylate Polymerizable unsaturated monomer having a group; polymerizable unsaturated monomer having a tricyclodecenyl group such as tricyclodecenyl (meth) acrylate; benzyl (meth) acrylate, styrene, α-methylstyrene, vinyltoluene, etc. Aromatic ring-containing polymerizable unsaturated monomers: vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane, vinyltriisopropoxy Silane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (meth) acryloyloxypropylmethyldiethoxysilane , Γ- (meth) acryloyloxypropyltri-n-propoxysilane, γ- (meth) acryloyloxypropyltriisopropoxysilane, vinyltriacetoxysilane, β- (meth) acryloyloxyethyltrimethoxysilane, etc. Polymerizable unsaturated monomer having a silyl group; perfluoroalkyl (meth) acrylate such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate; fluoroolefin, etc. Polymerizable unsaturated monomer having a fluorinated alkyl group; vinyl compounds such as N-vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate and vinyl acetate; (meth) acrylonitrile, (meth) acrylamide, methylenebis (meth) acrylamide, Nitrogen-containing polymerizable unsaturated monomers such as ethylenebis (meth) acrylamide, 2- (methacryloyloxy) ethyltrimethylammonium chloride, adducts of glycidyl (meth) acrylate and amines; glycidyl (meth) acrylate, β-methylglycidyl (Meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate Polymerization having at least two polymerizable unsaturated groups such as allyl (meth) acrylate, 1,6-hexanediol di (meth) acrylate, etc. in an epoxy group-containing polymerizable unsaturated monomer such as acrylate and allyl glycidyl ether Unsaturated monomers; (meth) acrylic acid such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the number of carbon atoms Monoesterified product of 2 to 8 dihydric alcohols; ε-caprolactone modified product of monoesterified product of (meth) acrylic acid and 2 to 8 carbon dihydric alcohols; Saturated monomer; hydroxyl group at the end or alkyleneoxy having 1 to 3 carbon atoms And a polyoxyalkylene group-containing (meth) acrylic monomer such as an acrylic monomer having a silyl group and having a polyoxyethylene group or a polyoxypropylene group.

The above polymerizable unsaturated monomers can be used alone or in combination of two or more.

In the present invention, “(meth) acrylate” in each compound means “acrylate or methacrylate”. “(Meth) acryl” means “acryl or methacryl”. “(Meth) acryloyl” means “acryloyl or methacryloyl”.

In the polymerizable unsaturated monomer, a hydroxyl group-containing polymerizable unsaturated monomer is preferably used from the viewpoint of adhesion, and a polymerizable unsaturated monomer having at least two polymerizable unsaturated groups in one molecule is used from the viewpoint of corrosion resistance. be able to.

When using a hydroxyl group-containing polymerizable unsaturated monomer, the amount used thereof is 0.1% by mass or more, preferably 1% by mass or more, in the total amount of all monomer components constituting the amino group-containing acrylic resin particles (A). More preferably, it is in the range of 1 to 10% by mass.

In the case of using a polymerizable unsaturated monomer having at least two polymerizable unsaturated groups in one molecule, the amount used is 0. of the total amount of all monomer components constituting the amino group-containing acrylic resin particles (A). It is suitable that the content is in the range of 05% by mass or more, preferably 0.1% by mass or more, more preferably 0.1 to 10% by mass.

The amino group-containing acrylic resin particles (A) are acrylic resin particles having a cationic core-shell structure containing an amino group.
From the viewpoint of dispersion stability of the amino group-containing acrylic resin particles (A), the amino group is preferably present in the shell.
The amino group-containing acrylic resin particles (A) preferably have an amino group-containing shell part obtained by polymerizing a monomer mixture containing an amino group-containing monomer.

Examples of the amino group-containing monomer include dimethylaminomethyl (meth) acrylate, diethylaminomethyl (meth) acrylate, dibutylaminomethyl (meth) acrylate, dihexylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and di Mention may be made of monomers such as isohexylaminoethyl acrylate, dihexylaminopropyl (meth) acrylate and di (tert-butyl) aminohexyl (meth) acrylate.

Of these, dimethylaminoethyl (meth) acrylate and diethylaminomethyl (meth) acrylate are preferred from the viewpoint of dispersion stability.

The amine value of the amino group-containing acrylic resin particles (A) is 14 to 72 mgKOH / g, preferably 20 to 72 mgKOH / g, more preferably 20 to 65 mgKOH / g.

In the present specification, the amine value (mgKOH / g) means the number of mg of potassium hydroxide when the amount of amino group contained in 1 g of sample (solid content in the case of resin) is converted into potassium hydroxide. It is represented by. The molecular weight of potassium hydroxide is 56.1.

Moreover, in this specification, the hydroxyl value (mgKOH / g) is the number of mg of potassium hydroxide when the amount of hydroxyl group contained in 1 g of sample (solid content in the case of resin) is converted into potassium hydroxide. It is a representation. The molecular weight of potassium hydroxide is 56.1.

As a method for producing the amino group-containing acrylic resin particles (A), for example, in the presence of a shell portion polymerized in advance, a monomer mixture for forming a core portion containing the aforementioned polymerizable unsaturated monomer using water as a main solvent. The method of polymerizing can be mentioned.

The charge ratio of the monomer mixture for forming the shell part and the core part can be appropriately selected according to the desired solid mass ratio of the core part / shell part.

In the aqueous metal surface treatment agent of the present invention, it is preferable to use a shell part synthesized by solution polymerization in an organic solvent from the viewpoint of coating properties such as corrosion resistance and water resistance due to film forming properties. . By employing a shell portion synthesized by solution polymerization, the amount of emulsifier that is negative for water resistance can be reduced.

Any appropriate polymerization initiator can be adopted as a polymerization initiator used in the polymerization of the amino group-containing acrylic resin particles (A).

As the polymerization initiator, any of oil-soluble and water-soluble types can be used, but water-soluble types can be preferably used.

Examples of the oil-soluble polymerization initiator include organic peroxides such as benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide; azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile) ) And the like.

Examples of the water-soluble polymerization initiator include hydrogen peroxide water; cumene hydroperoxide, tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, Organic peroxides such as diisopropylbenzene hydroperoxide; azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2- Methyl propionate), azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], azobis {2-methyl-N- [2- (1-hydroxybutyl)]-propionamide}, etc. Compound: potassium persulfate, ammonium persulfate Can be mentioned um, persulfate salts such as sodium persulfate.

These can be used alone or in combination of two or more.

Furthermore, if necessary, a reducing agent such as sugar, sodium ascorbate, sodium formaldehyde sulfoxylate, or iron complex may be used in combination with the polymerization initiator to form a redox polymerization system.

The polymerization initiator is preferably used in a range of generally 0.1 to 5% by mass, particularly 0.2 to 3% by mass, based on the total mass of all monomers used. The method for adding the polymerization initiator is not particularly limited, and can be appropriately selected according to the type and amount thereof. For example, the polymerization initiator may be preliminarily included in the monomer mixture or the aqueous medium, or at the time of polymerization. It may be added all at once or may be dropped.

From the viewpoint of coating performance such as water resistance, it is preferable not to use an emulsifier, but an emulsifier can be used in the polymerization of the amino group-containing acrylic resin particles (A). Any appropriate emulsifier can be adopted as the emulsifier. For example, cationic surfactants such as alkylamine salts and quaternary ammonium salts; polyoxyethylene alkyl ethers such as polyoxyethylene nonylphenyl ether, sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene-polyoxypropylene Nonionic surfactants such as block copolymers and reactive nonionic surfactants; (modified) polyvinyl alcohol and the like can be mentioned.

The above emulsifiers can be used alone or in combination of two or more.

The content of the emulsifier is preferably 0.01 to 10% by mass with respect to the total amount of monomers used in the polymerization of the amino group-containing acrylic resin particles (A). Furthermore, chain transfer agents such as tert-dodecyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methylstyrene dimer can be used as necessary. .

The polymerization temperature in the polymerization of the amino group-containing acrylic resin particles (A) is preferably 40 to 110 ° C., more preferably 40 to 90 ° C. The polymerization time is preferably 1 to 12 hours, more preferably 1 to 6 hours.

The shell part can be obtained by polymerizing a monomer mixture for forming a shell part containing the above-mentioned polymerizable unsaturated monomer and amino group-containing monomer.

Any appropriate solvent can be adopted as a solvent used when the shell portion is polymerized. As the solvent, for example, alcohol solvents, cellosolve solvents, carbitol solvents and the like are preferable. Specifically, for example, alcohol solvents such as n-butanol; ethylene glycol monobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol mono n-butyl ether, Examples thereof include cellosolve solvents such as dipropylene glycol monomethyl ether and dipropylene glycol mono n-butyl ether; carbitol solvents such as diethylene glycol monobutyl ether, diethylene glycol monoethyl ether and diethylene glycol monoethyl ether acetate.

In addition, organic solvents that are not mixed with water other than those described above can be used as long as they do not hinder the water dispersion stability of the amino group-containing acrylic resin particles (A). Examples of such an organic solvent include aromatic hydrocarbon solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl ethyl ketone and cyclohexanone.

Any appropriate polymerization initiator can be adopted as the polymerization initiator used when the shell portion is polymerized. Examples of the polymerization initiator include benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, di-tert-amyl peroxide, tert-butyl peroxide. Organic peroxides such as -2-ethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, diisopropylbenzene hydroperoxide; azobisisobutyronitrile, Azobis (2,4-dimethylvaleronitrile), azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4'-azobis (4-cyanobuta Acid), dimethylazobis (2-methylpropionate), azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], azobis {2-methyl-N- [2- (1-hydroxybutyl) )]-Propionamide} and the like.

These polymerization initiators may be used alone or in combination of two or more.

The blending amount of the polymerization initiator is usually 0.01 to 20% by mass, preferably 0.1 to 15% by mass based on the total amount of the polymerizable unsaturated monomers used, from the viewpoint of polymerization reactivity and the like. More preferably, it can be in the range of 0.3 to 10% by mass.

The polymerization temperature in the polymerization of the shell part is preferably 80 to 250 ° C., more preferably 100 to 210 ° C. The polymerization time is preferably 1 to 12 hours, more preferably 2 to 8 hours.

The weight average molecular weight of the shell part is usually in the range of 5,000 to 400,000, particularly 10,000 to 200,000, and the water dispersibility and storage of the amino group-containing acrylic resin particles (A). Suitable from the viewpoint of stability and manufacturing.

The shell part may have a functional group such as an unsaturated group, an epoxy group, a hydroxyl group, a carboxyl group, or an isocyanate group, and these groups can be introduced into the shell part by a known method.

In addition, the number average molecular weight and the weight average molecular weight in this specification are the number average molecular weight and the weight average molecular weight measured by gel permeation chromatograph (trade name “HLC8120GPC” manufactured by Tosoh Corporation), and the molecular weight of standard polystyrene. It is the value converted with reference. In this measurement, a total of three columns, “TSKgel Super-H3000” manufactured by Tosoh Corporation and two “TSKge Super-H2500” manufactured by Tosoh Corporation (both trade names), were used as mobile columns. : Tetrahydrofuran (containing 0.5% by mass of triethanolamine), measurement temperature: 25 ° C., flow rate: 0.6 mL / min, detector: measured under the conditions of a differential refractometer.

(Method for producing amino group-containing acrylic resin particles (A))
The amino group-containing acrylic resin particles (A) are acrylic resin particles having a form in which the core portion is dispersed in an aqueous medium using the shell portion as a dispersion stabilizer.

A typical production method of the amino group-containing acrylic resin particles (A) is shown below, but the production method of the amino group-containing acrylic resin particles (A) is not limited to this method.

1. A shell polymer, which is a dispersion stabilizer synthesized in advance, is added to an aqueous medium.

2. Next, a neutralizing agent for shell part amino groups and deionized water are added to obtain an aqueous dispersion.

The neutralizing agent is not particularly limited as long as it can neutralize an amino group, and examples thereof include organic compounds such as acetic acid and formic acid, and acidic compounds such as inorganic acids.

These neutralizing agents are desirably used in such an amount that the pH of the aqueous dispersion of the amino group-containing acrylic resin particles (A) is finally about 4.0 to 8.0.

These neutralizing agents are usually used in an amount of 0.1 to 1.0 equivalent, preferably 0.3 to 1.0 equivalent, based on a basic group such as an amino group.

The aqueous dispersion can be obtained by dispersion with an ordinary stirrer, but a homomixer, a homogenizer, a disper, a line mixer, or the like can also be used to obtain a uniform aqueous dispersion having a finer particle size.

3. A polymerizable monomer mixture constituting the core part and a radical polymerization initiator are added to the aqueous dispersion, and a polymerization reaction of the polymerizable unsaturated monomer constituting the core part is performed by a conventional method.

By performing the above steps, an aqueous dispersion of amino group-containing acrylic resin particles (A) can be produced.

The amino group-containing acrylic resin particles (A) are generally 10 to 5,000 nm, preferably 10 to 1,000 nm, more preferably 20 to 500 nm, and still more preferably 50 to 300 nm from the viewpoint of dispersibility and storage stability. It can have an average particle size within the range.

In the present specification, the average particle diameter of the amino group-containing acrylic resin particles (A) is a value measured at 23 ° C. after being diluted with deionized water by a conventional method using a submicron particle size distribution analyzer. As the submicron particle size distribution measuring device, for example, “COULTER N5 type” (trade name, manufactured by Beckman Coulter, Inc.) can be used.

The solid content concentration of the amino group-containing acrylic resin particles (A) in the aqueous dispersion is preferably 20 to 50% by mass, more preferably 30 to 40% by mass. When the solid content concentration exceeds 50% by mass, emulsification becomes difficult and an aqueous dispersion may be difficult to obtain. If the solid content concentration is less than 20% by mass, the concentration of the solvent (mainly water) increases because of the low concentration, and for example, it may be difficult to use as a component of the aqueous metal surface treatment agent.

[Phosphate compound (B)]
The aqueous metal surface treatment agent of the present invention also contains a phosphoric acid compound (B). The phosphoric acid compound (B) is a compound that contains a phosphate group, a phosphonic acid group, or a salt of these groups and has water solubility. The phosphoric acid compound (B) can be phosphoric acid, organic phosphonic acid and salts thereof.

The phosphoric acid includes, for example, orthophosphoric acid and condensed phosphoric acid, and the condensed phosphoric acid includes metaphosphoric acid and polyphosphoric acid. Metaphosphoric acid is a cyclic phosphoric acid condensate, including trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, etc., and polyphosphoric acid is a chain phosphoric acid condensate, pyrophosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid Etc.

Examples of the organic phosphonic acid include hydroxyl group-containing organic phosphonic acids such as hydroxymethane diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid (HEDP), and 1-hydroxypropane-1,1-diphosphonic acid; Carboxyl group-containing organic phosphonic acids such as 2-hydroxyphosphonoacetic acid and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC); nitrilotris (methylenephosphonic acid) (NTMP), nitrilotris (ethylenephosphonic acid), Alkylene having the same or different alkylene groups, such as nitrilotris (propylenephosphonic acid), nitrilobis (ethylenephosphonic acid) mono (methylenephosphonic acid), nitrilobis (methylenephosphonic acid) mono (propylenephosphonic acid), etc. The nitrilotri group (Alkylenephosphonic acid); ethylenediaminetetramethylenephosphonic acid, ethylenediaminetetraethylenephosphonic acid, ethylenediaminetetraalkylenephosphonic acid such as ethylenediaminetetraethylenephosphonic acid, ethylenediaminetetraalkylenephosphonic acid having an alkylene group of 1 to 4 carbon atoms; hexamethylenediaminetetramethylene Examples include phosphonic acid; diethylenetriaminepentamethylenephosphonic acid and the like.

Examples of the phosphoric acid and organic phosphonic acid salts include alkali metal salts (lithium salts, sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, barium salts, etc.), ammonium salts, and the like. Can be mentioned. In consideration of solubility, salts such as zinc, manganese and nickel can also be used.

When there are a plurality of phosphoric acid groups or phosphonic acid groups in one molecule of the phosphoric acid compound (B), some of them may be a salt or all may be a salt. In addition, some or all of the active hydrogen atoms of the phosphate group or phosphonic acid group may be substituted with alkali metal ions or ammonium ions.

These phosphoric acid compounds (B) can be used alone or in combination of two or more.

The phosphoric acid compound (B) has the effect of improving the storage stability of the surface treatment agent of the present invention and improving the corrosion resistance of the surface treatment film, and in particular, orthophosphoric acid, hydroxymethane diphosphonic acid, 1- Hydroxyethane-1,1-diphosphonic acid is preferred.

The blending amount of the phosphoric acid compound (B) is 0.5 to 10% by mass, preferably 3 to 8% by mass, based on the total solid content of the amino group-containing acrylic resin particles (A). Suitable from the viewpoint of both corrosion resistance and water resistance.

[Fluorometallic acid and / or its salt (C)]
The fluorometallic acid and / or salt thereof (C) blended in the aqueous metal surface treatment agent of the present invention as necessary improves the corrosion resistance of the surface treatment film obtained from the aqueous metal surface treatment agent of the present invention. Formulated for purpose.

The fluoro metal acid is an acid containing a fluorine atom and a metal. Examples of the metal include titanium, zirconium, hafnium, vanadium, magnesium, manganese, zinc, tungsten, molybdenum, aluminum, nickel, cobalt, and calcium. It can be 1 type or 2 types or more of metals, such as. Among these, titanium or zirconium is particularly preferable because it is inexpensive and relatively easily available for industrial use.

Examples of the fluorometal acid include hexafluorotitanic acid (H ₂ TiF ₆ ), hexafluorozirconic acid (H ₂ ZrF ₆ ), hexafluorohafnium acid (H ₂ HfF ₆ ), and hexafluoroaluminum acid. (H ₃ AlF ₆ ), tetrafluoroboric acid (HBF ₄ ), and the like can be given.

Examples of the salt of the fluorometal acid include sodium salt, potassium salt, lithium salt, ammonium salt, amine salt and zinc salt of the fluorometal acid.

As the fluorometallic acid and / or its salt (C), the above-mentioned fluorometallic acids and their salts can be used alone or in combination of two or more.

Fluorometal acids and / or salts thereof (C) include, among others, hexafluorotitanic acid (H ₂ TiF ₆ ), hexafluorozirconic acid (H ₂ ZrF ₆ ), ammonium salts of these fluorometal acids, amines A salt is preferred from the viewpoint of corrosion resistance.

Fluorometallic acid and / or its salt (C) generates ions in water, controls the corrosion potential and oxidation-reduction reaction of the metal surface in the corrosive environment, forms a very thin film on the metal surface, and film components It is thought that it has the effect of improving the corrosion resistance by, for example, improving the film density due to the crosslinking reaction with the functional group therein.

The blending amount of the fluorometal acid and / or salt thereof (C) is 1 to 5% by mass, preferably 2 to 4% by mass, based on the total solid content of the amino group-containing acrylic resin particles (A). It is suitable from the viewpoint of improved corrosion resistance and stability of the processing solution.

[Vanadium compound (D)]
The vanadium compound (D) blended in the aqueous metal surface treatment agent of the present invention as necessary is blended for the purpose of improving the corrosion resistance of the surface treatment film obtained from the aqueous metal surface treatment agent of the present invention.

The vanadium compound (D) is preferably water-soluble or water-dispersible. Further, the vanadium compound (D) can be, for example, carbonate, phosphate, nitrate, sulfate, acetate, oxide, etc., and may be an anhydride or a hydrate.

Examples of the vanadium compound (D) include ammonium metavanadate, sodium metavanadate, potassium metavanadate, vanadyl sulfate, and vanadium oxide. Among them, ammonium metavanadate is particularly preferable from the viewpoint of solubility in an acidic aqueous solution. Sodium metavanadate, potassium metavanadate and vanadyl sulfate are preferred.

The amount of the vanadium compound (D) is 0.1 to 5% by mass, preferably 0.3 to 1% by mass, based on the total solid content of the amino group-containing acrylic resin particles (A). It is suitable from the viewpoint of stability.

[Silane coupling agent and / or hydrolysis condensate thereof (E)]
The silane coupling agent and / or its hydrolysis condensate (E), which is blended as necessary with the aqueous metal surface treatment agent of the present invention, improves the adhesion of the resulting surface treatment film to the substrate surface, In some cases, the film can contribute to improving the corrosion resistance and water resistance of the film.

Examples of the silane coupling agent include N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane. N-β (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl Methyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, methyltrimethoxysilane, vinyltriacetoxysilane, γ-chloropropyltrimethoxysilane, Examples include oxamethyldisilazane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, and trimethylchlorosilane.
Of these, epoxy group-containing silane coupling agents such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane are preferred.

These silane coupling agents may be used alone or in combination of two or more.

The hydrolysis condensate of the silane coupling agent means an oligomer of a silane coupling agent hydrolyzed and condensed from the silane coupling agent as a raw material.

The blending amount of the silane coupling agent and / or its hydrolysis condensate (E) is 0.1 to 20% by mass, preferably 2 to 15% by mass, based on the total solid content of the amino group-containing acrylic resin particles (A). % Is suitable from the viewpoint of the storage stability of the surface treatment agent, the corrosion resistance of the resulting surface treatment film and the adhesion of the top coat.

[Polyolefin wax (F)]
The polyolefin wax (F) blended in the aqueous metal surface treatment agent of the present invention as necessary is a component that imparts lubricity to the obtained surface treatment film.

Examples of the polyolefin wax (F) include polyethylene, polypropylene, and microcrystalline.

The blending amount of the polyolefin wax (F) is 0.1 to 10% by mass, preferably 0.3% as a solid content with respect to the total solid content of the aqueous metal surface treatment agent from the viewpoint of molding processability and corrosion resistance. It is suitable to be in the range of ˜8% by mass.

The average particle diameter of the polyolefin wax (F) is 0.1 to 3 μm, preferably 0.5 to 2 μm, from the viewpoint of maintaining a low dynamic friction coefficient.

[Solvent and other ingredients]
The aqueous metal surface treatment agent of the present invention is aqueous. Aqueous means that the solvent has water as a main component. The solvent may be water alone, but for the purpose of adjusting the drying property of the film, the viscosity of the treatment agent, etc., one or two of various water-soluble organic solvents such as monovalent or polyhydric alcohols, ketones, ether alcohols, etc. Two or more species may be used in combination. The aqueous metal surface treatment agent of the present invention preferably contains 70% by mass or more, and particularly preferably 80% by mass or more of water in the solvent.

If necessary, the aqueous metal surface treatment agent of the present invention may be a pH adjuster (acid or base), titanium-containing aqueous liquid, filler, colloidal silica, colorant, interface, in addition to the solvent and the components described above. An activator, an antifoaming agent, a leveling agent, an antibacterial agent and the like can be blended. These can be added in the range which does not impair the performance of the treatment film obtained and the stability of the surface treatment agent.

As the pH adjuster, for example, acetic acid, formic acid, lactic acid, aqueous ammonia and the like can be suitably used.

The aqueous metal surface treatment agent of the present invention preferably has a pH of 3 to 7, more preferably a pH of 3.5 to 6.5, from the viewpoint of liquid stability.
The solid content concentration of the aqueous metal surface treatment agent of the present invention is preferably 5 to 30% by mass, particularly preferably 10 to 25% by mass, from the viewpoint of coating workability and the stability of the treatment liquid.

The above-mentioned aqueous titanium-containing liquid may be effective in improving the corrosion resistance of the resulting treated film. The titanium-containing aqueous liquid is obtained by reacting at least one titanium compound selected from hydrolyzable titanium, hydrolyzable titanium low condensate, titanium hydroxide and titanium hydroxide low condensate with hydrogen peroxide. (See, for example, Japanese Patent Application Laid-Open No. 2006-22370). When the titanium-containing aqueous liquid is blended, the blending amount is 5.0% by mass or less in terms of solid content with respect to the total solid content of the amino group-containing acrylic resin particles (A). It is preferable from the viewpoint.

Examples of the filler include fine powders such as silica, talc, barita, calcium carbonate, mica, and examples of those used as extender pigments. Examples of the colorant include color pigments and dyes.

[Metal surface treatment method]
The metal surface treatment method of the present invention is a metal surface treatment method in which the aqueous metal surface treatment agent of the present invention is applied on a metal substrate and dried, and the surface of the metal substrate is treated with the aqueous metal surface treatment agent of the present invention. This is a method of forming a treatment film. In the present invention, the “treated film” includes not only a continuous treated film, but also a treated product that is not a continuous treated film due to a small amount of treated adhesion, but also becomes discontinuous.

The metal substrate is not limited as long as it is a metal material, and includes, for example, iron, copper, aluminum, tin, zinc and alloys containing these metals, and plated steel plates or vapor deposition products of these metals. It is done. Especially, the metal plate by the said metal can be used conveniently.

Examples of the metal plate used as the metal substrate include cold-rolled steel sheets, hot-dip galvanized steel sheets, electrogalvanized steel sheets, zinc alloy (alloys such as zinc-iron, zinc-aluminum, zinc-nickel) plated steel sheets, aluminum A plated steel plate, a stainless steel plate, a copper plated steel plate, a tin plated steel plate, an aluminum plate, a copper plate, etc. can be mentioned. Among these, galvanized steel sheets (including both hot dip galvanized steel sheets and electrogalvanized steel sheets) and zinc alloy plated steel sheets are suitable.

Before applying the aqueous metal surface treatment agent of the present invention on the metal substrate, the surface of the metal substrate can be adjusted by one or more of degreasing, pickling, hot water washing, detergent washing, etc. Also in this case, it is preferable to thoroughly wash with water at the end. Further, the liquid temperature of the aqueous metal surface treatment agent of the present invention at the time of application may be room temperature, but may be cooled or heated as desired.

Also, a first layer may be formed on the surface of the metal base material by other surface treatment. The first layer is formed for the purpose of, for example, enhancing adhesion between the treatment film formed by the aqueous metal surface treatment agent of the present invention and the metal surface, and is preferably formed of a chromium-free surface treatment agent.

On the metal substrate, the aqueous metal of the present invention is formed by a known method such as a roll coating method, a spray coating method, a brush coating method, an electrostatic coating method, an immersion method, an electrodeposition coating method, a curtain coating method, or a roller coating method. A surface treatment film can be formed by coating and drying the surface treatment agent. In addition, formation of the surface treatment film mentioned above may be only one side or both sides of the metal substrate.

The coating amount of the treatment film by the aqueous metal surface treatment agent of the present invention is not particularly limited, but is usually 0.4 to 3.6 g / m ² , preferably 0.5 to 2.5 g / m ² . It is suitable from a viewpoint of corrosion resistance and workability that it is a range. The drying conditions of the treated film may be set as appropriate. However, when continuously coating the material coated by the coil coating method or the like, the maximum material reaching temperature is usually 60 to 200 ° C, preferably 70 to 120 ° C. It can be performed by heating for 5 to 60 seconds under the following conditions. In the case of baking in a batch method, for example, it can be performed by heating at an atmospheric temperature of 100 to 180 ° C. for 1 to 30 minutes.

[Surface-treated metal plate]
The surface-treated metal plate of the present invention is a surface-treated metal plate obtained by performing surface treatment with the aqueous metal surface treatment agent of the present invention on the surface of a metal substrate. The surface-treated metal plate of the present invention has a plate-like metal base material, and can be obtained by the metal surface treatment method of the present invention.

In the surface-treated metal plate of the present invention, the coating amount of the treated film by the aqueous metal surface treatment agent of the present invention is in the range of 0.4 to 3.6 g / m ² , preferably 0.5 to 2.5 g / m ² . It is preferable from the viewpoint of corrosion resistance and workability.

On the treated film of the surface-treated metal plate of the present invention, an upper film such as a colored coating or a clear coating can be further formed for the purpose of improving cosmetics, improving durability, and improving functionality. . The formation of the upper layer film can be performed before the surface-treated metal plate of the present invention is molded, but is preferably performed after the molding process.

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

In each example, “part” and “%” are based on mass unless otherwise specified. Further, the coating amount of the treatment coating is based on the dry coating amount.

[Example of production of shell portion of amino group-containing acrylic resin particles]
(Production of amino group-containing acrylic resin (S1) solution)
Into a reaction vessel equipped with a thermometer, thermostat, stirrer, reflux condenser, nitrogen gas inlet tube and dripping device, 50 parts of propylene glycol (PG) monomethyl ether was charged, stirred and mixed in a nitrogen stream, and heated to 105 ° C. After warming, 20 parts of styrene (St), 45 parts of methyl methacrylate (MMA), 5 parts of n-butyl acrylate (nBA), 5 parts of 2-hydroxyethyl acrylate (2-HEA) and 2- (N, N-dimethylamino) ) A mixture of 25 parts of ethyl methacrylate (DMAEMA) and 2 parts of tert-butylperoxy-2-ethylhexanoate (PBO) and 15 parts of propylene glycol (PG) monomethyl ether were dropped simultaneously over 3 hours. After completion, the mixture was aged for 1 hour.

Thereafter, the mixture was diluted with propylene glycol monomethyl ether and stirred for 30 minutes to obtain an amino group-containing acrylic resin (S1) solution having a solid content concentration (NV value) of 45%.

The amino group-containing acrylic resin (S1) obtained had an amine value of 90 mgKOH / g, a hydroxyl value of 22 mgKOH / g, and a weight average molecular weight (Mw) of 45,000.

(Production of amino group-containing acrylic resins (S2) to (S14))
In the same manner as described above, amino group-containing acrylic resins (S2) to (S14) were obtained according to the compositions shown in Tables 1 and 2 below.

[Synthesis example of Core / Shell emulsion]
(Production of amino group-containing acrylic resin particles (A1) aqueous dispersion)
In a reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen gas inlet tube and dropping device, 111 parts of an amino group-containing acrylic resin (S1) solution having a solid content concentration of 45% was stirred and mixed. After the temperature was raised to 80 ° C., the solvent was removed under reduced pressure until the solid content concentration reached 69%.

Next, it is cooled to 60 ° C., 20 parts of styrene, 20 parts of methyl methacrylate, 7 parts of n-butyl acrylate, 2.5 parts of 2-hydroxyethyl methacrylate (2-HEMA), 0.5 part of allyl methacrylate (AMA), 3 parts of acetic acid was added to the reaction vessel and mixed with stirring for 15 minutes.

Subsequently, after cooling to 40 degreeC, 180 parts of deionized water (DIW) was dripped over 1 hour, and it age | cure | ripened for 15 minutes after completion | finish of dripping.
Thereafter, the temperature was raised to 60 ° C., 0.3 parts of sodium ascorbate and 0.3 part of 5% ferrous sulfate aqueous solution were added, and then 0.4 part of 30% hydrogen peroxide water and 30 parts of deionized water The mixture was added dropwise over 1 hour, then aged for 1 hour, and measured at 23 ° C. using an average particle size of 75 nm [submicron particle size distribution analyzer “COULTER N5 type” (Beckman Coulter, Inc.). An amino group-containing acrylic resin particle (A1) aqueous dispersion having a solid content concentration of 30% was obtained.

The amine value of the obtained amino group-containing acrylic resin particles (A1) was 45 mgKOH / g, the hydroxyl value was 23 mgKOH / g, and the weight average molecular weight was 1,200,000.

(Manufacture of A2 to A15)
In the same manner as described above, amino group-containing acrylic resin particles (A2) to (A15) in aqueous dispersion were obtained according to the compositions shown in Tables 3 and 4 below.

In the amino group-containing acrylic resin particles (A1) to (A15), the constituent ratio (mass ratio) between the core part and the shell part is as follows.
(A1) to (A13) Core portion: shell portion = 50: 50
(A14) Core portion: Shell portion = 90: 10
(A15) Core portion: Shell portion = 10: 90

(Production of amino group-containing acrylic resin particles (A16) aqueous dispersion)
An amino group-containing acrylic resin particle (A1) having an average particle diameter of 55 nm is solid, except that 111 parts of an amino group-containing acrylic resin (S13) solution having a solid content of 45% and 6 parts of acetic acid are used. An amino group-containing acrylic resin particle (A16) aqueous dispersion having a partial concentration of 30% was obtained.
The amino group-containing acrylic resin particles (A16) thus obtained had an amine value of 90 mgKOH / g, a hydroxyl value of 23 mgKOH / g, and a weight average molecular weight of 1,200,000.

(Production of amino group-containing acrylic resin particles (A17) aqueous dispersion)
The average particle diameter is 240 nm in the same manner as the amino group-containing acrylic resin particle (A1) aqueous dispersion, except that 111 parts of an amino group-containing acrylic resin (S14) solution having a solid content concentration of 45% and 0.6 part of acetic acid are used. An amino group-containing acrylic resin particle (A17) aqueous dispersion having a solid content concentration of 30% was obtained.
The amino group-containing acrylic resin particles (A17) thus obtained had an amine value of 9 mgKOH / g, a hydroxyl value of 23 mgKOH / g, and a weight average molecular weight of 1,200,000.

(Production of amino group-containing acrylic resin particles (A18) aqueous dispersion)
In a reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen gas inlet tube and dropping device, 110 parts of deionized water, “ADEKA rear soap ER-40” (trade name, manufactured by ADEKA Corporation, emulsifier) , 60% active ingredient) was charged, and the mixture was stirred and mixed in a nitrogen stream and heated to 60 ° C.

Next, 5% of the total amount of the following monomer emulsion for core part, 10% “Kayabutyl H-70” (trade name, manufactured by Kayaku Akzo Co., Ltd., polymerization initiator, tert-butyl hydroperoxide, active ingredient) 70%) 1 part aqueous solution and 1 part 3% aqueous sodium ascorbate solution were added to the reaction vessel and held at 60 ° C. for 1 hour.

Thereafter, the remainder of the following monomer emulsion for the core part, 7 parts of a 10% “Kayabutyl H-70” aqueous solution and 10 parts of a 3% aqueous sodium ascorbate solution were dropped into a reaction vessel maintained at the same temperature over 2 hours, After completion of dropping, aging was performed for 1 hour.

Next, 5 parts of a 10% “Kayabutyl H-70” aqueous emulsion and 10 parts of a 3% aqueous sodium ascorbate solution were added dropwise over 2 hours and aged for 1 hour, and then 0.6 parts of acetic acid. Was added to the reaction vessel and held for 30 minutes.

Next, the mixture was cooled to 30 ° C. and diluted with deionized water to obtain an amino group-containing acrylic resin particle (A18) aqueous dispersion having an average particle diameter of 170 nm and a solid content concentration of 30%.

The amino group-containing acrylic resin particles (A18) thus obtained had an amine value of 10 mgKOH / g, a hydroxyl value of 16 mgKOH / g, and a number average molecular weight of about 65,000.

Monomer emulsion for shell part: 20 parts of deionized water, 3.5 parts of “ADEKA rear soap ER-40”, 3 parts of styrene, 19 parts of methyl methacrylate, 3 parts of n-butyl methacrylate (nBMA), n-butyl acrylate 2 Monomer emulsion obtained by mixing 2 parts of 2-hydroxyethyl methacrylate and 1 part of 2- (N, N-dimethylamino) ethyl methacrylate.

Monomer emulsion for core part: 40 parts of deionized water, 7 parts of “ADEKA rear soap ER-40”, 44 parts of methyl methacrylate, 17 parts of n-butyl methacrylate, 5 parts of n-butyl acrylate, 2 parts of 2-hydroxyethyl methacrylate And a monomer emulsion obtained by mixing 2 parts of 2- (N, N-dimethylamino) ethyl methacrylate.

(Production of amino group-containing acrylic resin particles (A19) aqueous dispersion)
In a reaction vessel equipped with a thermometer, thermostat, stirring device, reflux condenser, nitrogen gas inlet tube and dropping device, 50 parts of propylene glycol monomethyl ether was charged and stirred and mixed in a nitrogen stream. 20 parts of styrene, 45 parts of methyl methacrylate, 5 parts of n-butyl acrylate, 5 parts of 2-hydroxyethyl acrylate, 25 parts of 2- (N, N-dimethylamino) ethyl methacrylate and tert-butylperoxy-2-ethylhexanoate 2 parts of the mixture was added dropwise over 3 hours and aged for 1 hour after completion of the addition.

Thereafter, the mixture was cooled to 60 ° C., 14 parts of acetic acid was added to the reaction vessel and held for 30 minutes, and then diluted with deionized water (DIW) to have an average particle size of 25 nm and an amino group-containing acrylic having an average particle size of 20%. A resin particle (A19) aqueous dispersion was obtained.

The amino group-containing acrylic resin particles (A19) thus obtained had an amine value of 90 mgKOH / g, a hydroxyl value of 23 mgKOH / g, and a weight average molecular weight of 45,000.

Amino group-containing acrylic resin particles (A16) to (A19) are for comparative examples, and for convenience, amino group-containing acrylic resin particles (A16) to (A19) are used. It is a resin particle which does not correspond to an amino group-containing acrylic resin particle (A).

In the amino group-containing acrylic resin particles (A16) to (A18), the constituent ratio (mass ratio) between the core part and the shell part is as follows.
(A16) to (A17) Core portion: Shell portion = 50: 50
(A18) Core portion: Shell portion = 70: 30

[Examples and Comparative Examples]
Each component was blended according to the blending ratio shown in the following table, adjusted by adding deionized water so that the solid content concentration was 15% by mass, and sufficiently stirred to obtain each metal surface treatment agent. The blending amount in the following table is based on the solid mass or the active ingredient mass.

In the table below, amino group-containing acrylic resin particles (A), phosphoric acid compounds (B), fluorometal acids and / or their salts (C), vanadium compounds (D), silane coupling agents and / or their The components of the hydrolysis condensate (E) and the polyolefin wax (F) are as follows.

In the following table, amino group-containing acrylic resin particles (A) components A1 to A19: Amino group-containing acrylic resin particles (A1) to (A19) obtained in the above [Synthesis example of Core / Shell emulsion]

In the table below, component of phosphoric acid compound (B) B1: orthophosphoric acid B2: 1-hydroxyethylidene-1,1-diphosphonic acid B3: nitrilotris (methylenephosphonic acid)

Components of fluorometallic acid and / or its salt (C) in the following table C1: Ammonium hexafluorotitanate C2: Ammonium hexafluorozirconate C3: Hexafluorotitanic acid C4: Hexafluorozirconic acid C5: Six Hafnium fluoride fluoride

Components of vanadium compound (D) in the following table D1: ammonium metavanadate D2: sodium metavanadate D3: vanadyl sulfate

In the following table, the component of the silane coupling agent and / or its hydrolysis condensate (E) E1: γ-methacryloyloxypropyltrimethoxysilane E2: 3-glycidoxypropyltrimethoxysilane E3: 3-mercaptopropyltrimethoxy Silane

Components of polyolefin wax (F) in the table below F1: Chemipearl W-700 manufactured by Mitsui Chemicals, Inc. Average particle size 1.5 μm
F2: HIDISPER AC-90 manufactured by Gifu Seratsuk Co., Ltd. Average particle size 1.3 μm
F3: HIDISPER A-206N manufactured by Gifu Seratsuk Manufacturing Co., Ltd. Average particle size 1 μm
F4: HIDISPER AG-73, average particle size 0.1 μm, manufactured by Gifu Seratsuk Manufacturing Co., Ltd.
F5: Chemipearl W-500 manufactured by Mitsui Chemicals, Inc. Average particle size 2.5 μm

[Water resistance test]
(Surface treatment metal plate production conditions)
A double-sided electrogalvanized steel sheet with a plating adhesion amount of 20 g / m ² on one side and a thickness of 0.8 mm was added to an alkaline degreasing agent with a concentration of 2% (trade name “Chem Cleaner 561B”, manufactured by Nippon C.B. The solution was spray degreased with a solution at a liquid temperature of 65 ° C. for 60 seconds, then washed with hot water at a liquid temperature of 50 ° C. for a spray time of 20 seconds, and dried to obtain an alkali degreased metal plate. The surface treatment agent obtained in the above [Examples and Comparative Examples] was applied to the obtained alkaline degreased metal plate with a bar coater so that the dry film weight was 0.9 g / m ^2, and the metal plate reached the maximum. Each surface-treated metal plate was obtained by heating and drying for 12 seconds so that the temperature was 60 ° C.

(Evaluation criteria)
Leave each surface-treated metal plate at room temperature for 5 minutes, place deionized water on the surface-treated metal plate for 2 minutes so that the diameter is about 3 cm, and then remove water drops with gauze etc. to change the appearance of the treated surface. The results were visually observed and evaluated according to the following criteria, and the results are shown in the following table.
A: No change was observed at all.
○: Discolored slightly white.
X: Discolored clearly white.
The practical level was “と し た” or “◯”.

[Copper sulfate discoloration test]
(Surface treatment metal plate production conditions)
A double-sided electrogalvanized steel sheet with a plating adhesion amount of 20 g / m ² on one side and a thickness of 0.8 mm was added to an alkaline degreasing agent with a concentration of 2% (trade name “Chem Cleaner 561B”, manufactured by Nippon C.B. The solution was spray degreased with a solution at a liquid temperature of 65 ° C. for 60 seconds, then washed with hot water at a liquid temperature of 50 ° C. for a spray time of 20 seconds, and dried to obtain an alkali degreased metal plate. The surface treatment agent obtained in the above [Examples and Comparative Examples] was applied to the obtained alkaline degreased metal plate with a bar coater so that the dry film weight was 0.9 g / m ^2, and the metal plate reached the maximum. Each surface-treated metal plate was obtained by heating and drying for 12 seconds so that the temperature became 80 ° C.

(Evaluation criteria)
Place 20 μL of 5% copper sulfate aqueous solution on the treated surface of each surface-treated metal plate, and after 15 seconds, remove the copper sulfate aqueous solution with gauze, etc., visually observe the appearance change of the treated surface and evaluate according to the following criteria The results are shown in the following table.
A: No discoloration was observed at all.
○: Slight discoloration was observed.
X: Discoloration was clearly recognized.
The practical level was “と し た” or “◯”.

[Corrosion resistance test]
(Surface treatment metal plate production conditions)
Each surface-treated metal plate was obtained under the same conditions and method as the copper sulfate discoloration test.

(General Department Evaluation Criteria)
Each surface-treated metal plate was cut into a width of 7 cm and a length of 15 cm to obtain a surface-treated metal test plate for corrosion resistance test. The end face part and the back face part of the obtained test plate are sealed, and by the salt spray test (SST) according to JIS Z 2371, the rust generation area on the treated surface is determined according to the rating number method, and the time until the rating number becomes 9 is determined. Evaluation was performed according to the following criteria, and the results are shown in the following table.
SS: The time until the rating number reached 9 was 96 hours or more.
S: The time until the rating number reached 9 was 72 hours or more and less than 96 hours.
A: The time until the rating number reached 9 was 48 hours or more and less than 72 hours.
B: The time until the rating number reached 9 was 24 hours or more and less than 48 hours.
C: The time until the rating number reached 9 was less than 24 hours.
The practical level was “SS”, “S”, “A” or “B”.

(Processing part evaluation criteria)
Each surface-treated metal plate was cut into a width of 7 cm and a length of 15 cm, and extruded with an Erichsen machine to obtain a surface-treated metal test plate for a processed portion corrosion resistance test having a dome-shaped processed portion until the height reached 7 mm. The end face part and the back face part of the obtained test plate are sealed, and by the salt spray test (SST) according to JIS Z 2371, the time until rust is generated at the zenith part of the dome-shaped processed part is evaluated according to the following criteria. The results are shown in the table below.
S: The time until rust was generated was 72 hours or more.
A: The time until rust was generated was 48 hours or more and less than 72 hours.
B: Time until rust was generated was 24 hours or more and less than 48 hours.
C: Time until rust was generated was less than 24 hours.
The practical level was “S”, “A” or “B”.

[Ethanol rubbing resistance test]
(Surface treatment metal plate production conditions)
Each surface-treated metal plate was obtained under the same conditions and method as the copper sulfate discoloration test.

(Evaluation criteria)
Soak four layers of gauze with ethanol, rub the treated surface of each surface-treated metal plate 10 times with a load of 1 kg, visually observe the appearance change of the treated surface and evaluate it according to the following criteria, and the results are shown in the table below. Indicated.
A: No change was observed at all.
○: A trace of rubbing was observed.
X: The rubbing trace was clearly recognized.
The practical level was “と し た” or “◯”.

[Dynamic friction coefficient measurement test]
(Surface treatment metal plate production conditions)
Each surface-treated metal plate was obtained under the same conditions and method as the copper sulfate discoloration test.

(Evaluation criteria)
For each surface-treated metal plate, with a Bowden abrasion tester (made by Shinko Engineering Co., Ltd., Iwata-type adhesion slip tester, friction part ball indenter 3/16 inch steel ball, load 200 gf, friction speed 7 reciprocations / min) A friction test was performed to measure the dynamic friction coefficient. The number of frictions until the value of the obtained dynamic friction coefficient reached 0.4 was evaluated according to the following criteria, and the results are shown in the following table.
S: The number of frictions until the value of the dynamic friction coefficient reached 0.4 was 20 or more.
A: The number of frictions until the value of the dynamic friction coefficient reached 0.4 was 10 times or more and less than 20 times.
B: The number of frictions until the value of the dynamic friction coefficient reached 0.4 was 5 or more and less than 10 times.
C: The number of frictions until the value of the dynamic friction coefficient reached 0.4 was less than 5.
The practical level was “S”, “A” or “B”.

As is clear from the above Examples and Comparative Examples, the surface-treated metal plate coated with the surface treatment agent of the present invention has water resistance, corrosion resistance (particularly, corrosion resistance of the surface-treated metal plate after Erichsen processing) and ethanol rubbing resistance. It was excellent in performance and satisfied performances such as a copper sulfate discoloration test and a dynamic friction coefficient.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on October 19, 2016 (Japanese Patent Application No. 2016-205570), the contents of which are incorporated herein by reference.

Claims (11)

1. An aqueous metal surface treatment agent comprising an amino group-containing acrylic resin particle (A) having a core-shell structure and an amine value of 14 to 72 mgKOH / g, and a phosphoric acid compound (B),
   An aqueous metal surface treatment agent containing 0.5 to 10% by mass of the phosphoric acid compound (B) based on the total solid content of the amino group-containing acrylic resin particles (A).
2. Furthermore, the aqueous metal surface treating agent of Claim 1 containing at least one (C) of a fluoro metal acid and its salt.
3. The aqueous metal surface treatment agent according to claim 1 or 2, further comprising a vanadium compound (D).
4. The aqueous metal surface treatment agent according to any one of claims 1 to 3, further comprising at least one of a silane coupling agent and a hydrolysis condensate thereof (E).
5. 5. The aqueous metal surface treatment agent according to claim 1, further comprising a polyolefin wax (F) having an average particle diameter of 0.1 to 3 μm.
6. The phosphoric acid compound (B) is at least one compound selected from the group consisting of orthophosphoric acid, hydroxymethane diphosphonic acid and 1-hydroxyethane-1,1-diphosphonic acid. The aqueous metal surface treatment agent according to claim 1.
7. The aqueous metal surface treating agent according to any one of claims 2 to 6, wherein the metal of at least one of the fluorometal acid and its salt (C) is titanium or zirconium.
8. The aqueous metal according to any one of claims 3 to 7, wherein the vanadium compound (D) is at least one compound selected from the group consisting of ammonium metavanadate, sodium metavanadate, potassium metavanadate, and vanadyl sulfate. Surface treatment agent.
9. The aqueous metal surface treatment agent according to any one of claims 1 to 8, wherein the pH is 3 to 7 and the solid content concentration is 5 to 30% by mass.
10. A metal surface treatment method in which the aqueous metal surface treatment agent according to any one of claims 1 to 9 is applied onto a metal substrate and dried.
11. A surface-treated metal sheet, wherein the surface of the metal substrate is subjected to a surface treatment with the aqueous metal surface treatment agent according to any one of claims 1 to 9.