TWI682011B - Metal surface treatment agent - Google Patents

Abstract

The present invention provides a non-chromate metal surface treatment agent that can impart excellent workability, adhesion, and corrosion resistance to a metal surface when used on a metal surface as a pretreatment agent for coating of paints and the like.

The above metal surface treatment agent contains a benzotriazole compound represented by the following general formula (1) and a silane coupling agent,

[In the formula, R ¹ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ² represents an alkylene group having 1 to 10 carbon atoms, and R ³ and R ⁴ independently represent a hydrogen atom and 1 to 10 carbon atoms. Alkyl group or a group represented by the following general formula (2), but at least one of R ³ and R ⁴ is a group represented by the following formula (2): -R ⁵ -OH (2)

(In the formula, R ⁵ represents an alkylene group having 1 to 10 carbon atoms)].

Description

Metal surface treatment agent

The present invention relates to a metal surface treatment agent, and more specifically, to a non-chromate metal surface treatment agent not containing chromium.

Conventionally, chromium-based surface treatment agents such as chromate and phosphate chromate have been widely used as metal surface treatment agents.

However, to inquire about the recent environmental regulations, due to the toxicity of chromium, especially carcinogenicity, and the possibility of restricting its use in the future, it is expected to develop non-free materials with the same adhesion and corrosion resistance as chromate treatment agents. Chromium (non-chromate) metal surface treatment agent.

As a non-chromate metal surface treatment agent, for example, in Patent Document 1, a non-chromate anti-rust treatment agent containing a water-soluble resin, a sulfocarbonyl group-containing compound, a phosphate ion, and a water-dispersible silica is disclosed, but this system Although it has excellent corrosion resistance, it has insufficient workability and adhesion to the substrate.

Patent Document 2 discloses an acidic surface treatment agent containing two or more kinds of silane coupling agents, but the system has insufficient corrosion resistance after the treatment of the metal surface is required when corrosion resistance and workability are required.

As a technique for solving these shortcomings, Patent Document 3 discloses that a silane coupling agent, water-dispersible silica, and zirconium or titanium ions are essential components. Non-chromate metal surface treatment agent. Although the corrosion resistance and workability of the surface treatment agent have been improved, the coating properties on the substrate and the adhesion strength with the upper coating film are still insufficient.

In addition, Patent Document 4 discloses a surface treatment agent for a steel structure containing a silane coupling agent having a specific functional group that reacts with an aqueous emulsion, but in this case, the required corrosion resistance is only for comparison such as a wet test It is a mild test without corrosion resistance that can withstand severe corrosion resistance tests.

Patent Document 5 discloses the use of organosilicon compounds containing imidazolyl groups in surface treatment agents such as metals, and Patent Document 6 discloses the use of organosilicon compounds containing benzotriazole groups in surface treatment agents such as metals. , But none of them have fully satisfied performance such as corrosion resistance or deep drawing.

Patent Document 7 discloses a compound containing an aqueous emulsion, 2 molecules of β-diketone and 2 molecules of water coordinated to a trivalent transition metal ion, and a surface treatment agent for rust prevention containing a silane coupling agent. The characteristic of this surface treatment agent is that trivalent transition metal complexes become insoluble compounds by drying to exhibit rust prevention ability and coating film adhesion ability, but the required corrosion resistance cannot withstand excessively harsh environments. There is 120,000 points of room for improvement.

As described above, there is no known metal surface treatment agent that can exhibit various characteristics such as corrosion resistance, process adhesion, coating property, and adhesive strength at a high level as a thin film, and it is desired to develop a surface treatment agent having such properties.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 11-29724

[Patent Document 2] Japanese Patent Laid-Open No. 8-073775

[Patent Document 3] Japanese Patent Laid-Open No. 2001-316845

[Patent Document 4] Japanese Patent Laid-Open No. 10-60315

[Patent Document 5] Japanese Patent Laid-Open No. 2000-297093

[Patent Document 6] Japanese Patent Laid-Open No. 6-279463

[Patent Document 7] Japanese Patent Application Publication No. 2007-297648

The present invention has been completed in view of the above circumstances, and an object thereof is to provide a non-chromic acid that can impart excellent workability, adhesion, and corrosion resistance to a metal surface when used as a pretreatment agent for the coating of a paint or the like when used on the metal surface. Salt metal surface treatment agent.

As a result of an active review by the present inventors to solve the above-mentioned problems, it was found that a composition containing an alcohol group-containing benzotriazole compound and a silane coupling agent as an essential component, due to the alkoxysilane in the alcohol group and silane coupling agent Based on the reaction, the benzotriazole layer and the siloxane layer are integrated, and a coating film excellent in rust prevention and corrosion resistance is obtained, so it can be preferably used as a metal surface treatment agent, thus completing the present invention.

That is, the present invention provides

[式中，R¹相互獨立表示氫原子或碳數1~10之烷基，R²表示碳數1~10之伸烷基，R³及R⁴相互獨立表示氫原子、碳數1~10之烷基、或以下述通式(2)表示之基，但R³及R⁴之至少一者為以下述式(2)表示之基：[化2]-R⁵-OH (2)(式中，R⁵表示碳數1~10之伸烷基)]。 1. A metal surface treatment agent characterized by containing a benzotriazole compound represented by the following general formula (1) and a silane coupling agent,

[In the formula, R ¹ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ² represents an alkylene group having 1 to 10 carbon atoms, and R ³ and R ⁴ independently represent a hydrogen atom and 1 to 10 carbon atoms. Alkyl group, or a group represented by the following general formula (2), but at least one of R ³ and R ⁴ is a group represented by the following formula (2): [Chem 2]-R ⁵ -OH (2)( In the formula, R ⁵ represents a C 1-10 alkylene group)].

2. The metal surface treatment agent according to the aforementioned 1, wherein the aforementioned R ² is a methylene group, R ³ and R ⁴ are both groups represented by the aforementioned general formula (2), and the aforementioned R ⁵ is an ethylidene group.

3. A metal surface treatment agent such as 1 or 2, wherein the aforementioned silane coupling agent is a silane coupling agent having an amine group.

4. Metal surface treatment agent such as 1 or 2, wherein the aforementioned silane coupling agent is a silane coupling agent having an epoxy group.

5. The metal surface treatment agent according to any one of 1 to 4, which contains an organic titanate.

6. The metal surface treatment agent according to any one of 1 to 5, which contains water-dispersible silica or organic solvent-dispersible silica.

7. The metal surface treatment agent according to any one of 1 to 6, which contains Fe, Zr, Ti, V, W, Mo, Al, Sn, Nb, Hf, Y, Ho, Bi, La, Ce and A compound of one or more metals of Zn.

8. The metal surface treatment agent according to any one of 1 to 7, which contains a compound containing a sulfur carbonyl group.

9. The metal surface treatment agent according to any one of 1 to 8, which contains a water-soluble resin or a water-dispersible resin.

10. The metal surface treatment agent according to any one of 1 to 9, which contains phosphoric acid ions.

Since the metal surface treatment agent of the present invention contains a benzotriazole compound having an alcohol group and a silane coupling agent as essential components, it is considered that the alcohol group and silane in the benzotriazole compound in the coating liquid or the coating film after treatment The transesterification reaction occurs between the alkoxysilyl groups in the coupling agent to integrate the benzotriazole group with the siloxane layer.

Therefore, the coated steel sheet treated with the metal surface treatment agent of the present invention exhibits high levels of rust and corrosion resistance.

The present invention will be specifically described below.

The metal surface treatment agent of the present invention is represented by the following general formula (1) The benzotriazole compound and silane coupling agent.

In formula (1), R ¹ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ² represents an alkylene group having 1 to 10 carbon atoms, and R ³ and R ⁴ independently represent a hydrogen atom and a carbon number 1 An alkyl group of ~10, or a group represented by the following general formula (2), but at least one of R ³ and R ⁴ is a group represented by the following formula (2).

【Chemical 4】-R ⁵ -OH (2)

(In the formula, R ⁵ represents an alkylene group having 1 to 10 carbon atoms)].

Here, the alkyl group having 1 to 10 carbon atoms may be linear, cyclic, or branched. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, and n-butyl. Straight-chain or branched alkyl, cyclopropyl, cyclobutyl, such as alkyl, second butyl, third butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, etc. Cycloalkyl groups such as alkyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc.

Specific examples of the alkylene group having 1 to 10 carbon atoms include methylene, ethylidene, trimethylene, propylidene, isopropylidene, tetramethylene, isobutylidene, and pentamethylene , Hexamethylene, heptamethylene, octamethylene, and nine methylene Base, decamethylene, etc.

Among them, R ^{1 is} preferably independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, and even more preferably a hydrogen atom or a methyl group, More preferably, at least one of R ¹ is a methyl group, and preferably any one of R ¹ is a methyl group, and the rest are hydrogen atoms.

R ^{2 is} preferably a C 1-5 alkylene group, more preferably a methylene group, an ethyl group, a trimethylene group, and even more preferably a methylene group.

R ³ and R ⁴ are preferably both groups represented by the above formula (2).

R ^{5 is} preferably a C 1-5 alkylene group, more preferably a methylene group, an ethyl group, a trimethylene group, and even more preferably an ethyl group.

Preferred benzotriazole compounds represented by formula (1) are exemplified by the following general formula (3).

(In the formula, R ¹ has the same meaning as described above).

In particular, 2,2'-[[(4-methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol (formula (4)), 2,2' can be preferably used -[[(5-methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol (formula (5)), 2,2'-[[(1H-benzotriazole -1-yl)methyl]imino]diethanol (formula (6)), etc.

In addition, as shown in the following formula (7), the methyl position on the benzotriazole ring is unspecified 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl] Amino] diethanol (produced by Chengbei Chemical Industry Co., Ltd., TT-LYK) is marketed, but this compound can also be preferably used in the present invention.

On the other hand, the silane coupling agent is not particularly limited, but can be appropriately selected and used by those skilled in the art. Specific examples thereof include an alkyl group silane coupling agent, an aryl group silane coupling agent, and a vinyl group silane. Coupling agent, silane coupling agent with amine group, silane coupling agent with epoxy group, silane coupling agent with (meth)acryloyl group, silane coupling agent with mercapto group, these can be used alone, or Use 2 or more types together.

Among these, a silane coupling agent having an amine group and a silane coupling agent having an epoxy group are preferred.

Specific examples of the silane coupling agent having an amine group include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane , 3-aminopropylmethyl diethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ- Aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-amino Propylmethyl diethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropylmethyldimethoxysilane, etc.

Specific examples of the silane coupling agent having an epoxy group are 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyl Dimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethylmethyldiethoxysilane , 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxy Propyl methyl diethoxy silane, etc.

In the metal surface treatment agent of the present invention, the amount of the silane coupling agent is preferably 0.1 to 100 times, more preferably 1 to 50 times, and more preferably 5 to 30 in terms of mass ratio relative to the benzotriazole compound. Times.

As described above, the metal surface treatment agent of the present invention can exhibit high rust and corrosion resistance by using a benzotriazole compound having a hydroxyl group and a silane coupling agent together.

As a reason for this, it is speculated that the hydrolyzability of the hydroxyl group of benzotriazolyl group and the silane coupling agent is integrated based on transesterification in the composition or in the coating film, In this way, benzotriazole forms complexes based on the metal surface, and forms a siloxane layer on the upper layer.

The metal surface treatment agent of the present invention preferably contains a solvent in addition to the above-mentioned essential components. Examples of the solvent include water, an organic solvent that can dissolve essential components, a benzotriazole compound, and a silane coupling agent, and a mixed solvent of the organic solvent and water.

Specific examples of the organic solvent include alcohol-based solvents such as methanol and ethanol; acylamine-based solvents such as methylamine, N,N-dimethylformamide, pyrrolidone, and N-methylpyrrolidone; Ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; saturated hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene, etc., Among these, methanol and ethanol are preferred.

In the case of metal surface treatment agents containing benzotriazole compounds, silane coupling agents and solvents, the above benzotriazole compounds are better It is preferably contained at a concentration of 0.01 to 100 g/L, more preferably at a concentration of 0.05 to 50 g/L.

On the other hand, when considering the obtained anti-corrosion and anti-corrosion effect and the liquid stability of the coating, etc., the above-mentioned silane coupling agent is preferably contained in the metal surface treatment agent at a concentration of 0.01 to 200 g/L, more preferably 0.05 to 100 g/ Contains L concentration.

The metal surface treatment agent of the present invention preferably further contains organic titanates.

Commercially available organic titanate esters can be used, and the structure and the like are not particularly limited. As specific examples, tetraethyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, and the And other polymers, or titanium chelate compounds such as titanium acetylacetonate, titanium titanium acetone, titanium octylglycinate, titanium lactate, titanium ethyl lactate, titanium triethanolamine, etc.

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

When using the above-mentioned organic titanate, the amount of the compound is considered to be contained in a concentration of 0.05 to 100 g/L in the metal surface treatment agent, considering the effect of improving the corrosion resistance and the bath stability of the metal surface treatment agent, and more preferably Contained at a concentration of 0.5~60g/L.

The metal surface treatment agent of the present invention preferably further contains water-dispersible silica or organic solvent-dispersible silica. In this case, specific examples of the organic solvent include alcohols such as methanol, ethanol, and isopropanol; ethers such as propylene glycol monomethyl ether, tetrahydrofuran, and the like.

The water- or organic-solvent-dispersible silica is not particularly limited, but it is preferable that sodium and other impurities are few, and it is a weak alkali-based spherical silica, chain silica, and aluminum-modified silica.

As spherical silica, colloidal silica such as "SNOWTEX N", "SNOWTEX UP" (both manufactured by Nissan Chemical Industry Co., Ltd.), or fumed oxidation such as "AEROSIL" (manufactured by Japan AEROSIL) can be used. Silicone can use "SNOWTEX PS" (manufactured by Nissan Chemical Industry Co., Ltd.) as silicon oxide chains, and "ADELITE AT-20A" (manufactured by ADEKA) for aluminum modified silica. Of various commercially available products.

When the above water or organic solvent dispersible silica is used, the amount of the compound, considering the effect of improving the corrosion resistance and the stability of the bath of the metal surface treatment agent, is calculated as the solid content in the metal surface treatment agent, preferably 0.05 to 100g Contains a concentration of /L, preferably 0.5 to 60g/L.

The metal surface treatment agent of the present invention preferably further contains any one or more selected from Fe, Zr, Ti, V, W, Mo, Al, Sn, Nb, Hf, Y, Ho, Bi, La, Ce, and Zn Metal compounds.

Examples of the compound of the above-mentioned metal include carbonates, oxides, hydroxides, nitrates, sulfates, phosphates, fluorides, fluoric acid or salts thereof, oxyacid salts, and organic acid salts of the above-mentioned metals.

Specific examples of the zirconium (Zr) compound include ammonium zirconium carbonate, zirconium hydrofluorate, ammonium zirconium fluoride, potassium zirconium fluoride, sodium zirconium fluoride, acetone zirconium zirconium, zirconium butoxide 1-butanol solution, positive Zirconium propoxide, etc.

Specific examples of titanium (Ti) compounds include titanium hydrofluorate, titanium ammonium fluoride, potassium titanium oxalate, titanium isopropoxide, isopropyl titanate, titanium ethoxide, and titanium 2-ethyl-1-hexanoate , Isopropyl titanate, tetra-n-butyl titanate, potassium titanium fluoride, sodium titanium fluoride, etc.

Specific examples of vanadium (V) compounds include vanadium pentoxide (V), vanadium trioxide (III), vanadium dioxide (IV), vanadium (II) hydroxide, vanadium (III) hydroxide, and vanadium sulfate (II) ), vanadium (III) sulfate, vanadyl sulfate (IV), vanadium fluoride (III), vanadium fluoride (IV), vanadium fluoride (V), vanadium oxychloride VOCl ₃ , vanadium trichloride VCl ₃ , Hexafluorovanadic acid (III) or its salts (potassium salt, ammonium salt, etc.), metavanadic acid (V) or its salts (sodium salt, ammonium salt, etc.), vanadium acetonate (IV) VO (OC (= CH ₂ )CH ₂ COCH ₃ ) ₂ , vanadium (III) acetylacetonate V(OC(=CH ₂ )CH ₂ COCH ₃ ) ₃ , phospho-vanadium molybdate H _15-X [PV _12-X MoO ₄₀ ]. nH ₂ O (6<X<12, n<30), etc.

Specific examples of the tungsten (W) compound include tungsten (IV) oxide, tungsten oxide (V), tungsten oxide (VI), tungsten fluoride (IV), tungsten fluoride (VI), and tungstic acid (VI) H ₂ WO ₄ or its salt (ammonium salt, sodium salt, etc.), metatungstic acid (VI) H ₆ [H ₂ W ₁₂ O ₄₀ ] or its salt (ammonium salt, sodium salt, etc.), paratungstic acid (VI) H ₁₀ [H ₁₀ W ₁₂ O ₄₆ ] or its salt (ammonium salt, sodium salt, etc.), etc.

As a specific example of a molybdenum (Mo) compound, phosphorus vanadium molybdate H _15-X [PV _12-X MoO ₄₀ ]. nH ₂ O (6<X<12, n<30), molybdenum oxide, molybdenum H ₂ MoO ₄ , ammonium molybdate, ammonium paramolybdate, sodium molybdate, molybdenum phosphate compounds (such as ammonium molybdate phosphate (NH ₄ ) ₃ [PO ₄ Mo ₁₂ O ₃₆ ]. 3H ₂ O, sodium molybdate Na ₃ [PO ₄ Mo ₁₂ O ₃₆ ]. nH ₂ O, etc.).

Specific examples of aluminum (Al) compounds include aluminum nitrate, aluminum sulfate, potassium aluminum sulfate, aluminum sulfate aluminum, aluminum ammonium sulfate, aluminum phosphate, aluminum carbonate, aluminum oxide, aluminum hydroxide, and the like.

Specific examples of tin (Sn) compounds include tin (IV) oxide, sodium stannate Na ₂ SnO ₃ , tin (II), tin (IV), tin (II) nitrate, and tin (IV) nitrate , Ammonium hexafluorostannate (NH ₄ ) ₂ SnF ₆ etc.

Specific examples of the niobium (Nb) compound include niobium pentoxide (Nb ₂ O ₅ ), sodium niobate (NaNbO ₃ ), niobium fluoride (NbF ₅ ), ammonium hexafluoroniobate (NH ₄ ) NbF ₆ and the like.

Specific examples of the hafnium (Hf) compound, yttrium (Y) compound, 鈥 (Ho) compound, bismuth (Bi) compound, and lanthanum (La) compound are hafnium oxide, hafnium hexafluoride, yttrium oxide, and acetone acetone Yttrium, yttrium oxide, bismuth oxide, lanthanum oxide, etc.

Specific examples of the cerium (Ce) compound include cerium oxide, cerium acetate Ce(CH ₃ CO ₂ ) ₃ , cerium (III) or (VI) nitrate, cerium ammonium nitrate, cerium sulfate, cerium chloride, and the like.

Specific examples of zinc (Zn) compounds include zinc oxide, zinc hydroxide, zinc acetate, zinc nitrate, zinc sulfate, zinc chloride, and sodium zincate.

In addition, each of the above metal compounds may be used alone, or two or more of the same species may be used in combination, or two or more of different species may be used in combination.

When using the above-mentioned metal compound, the amount of the compound is calculated based on the amount of each metal ion in the metal surface treatment agent when considering the effect of improving the corrosion resistance, the effect of improving the crosslinking adhesion performance, and the bath stability of the metal surface treatment agent The concentration is preferably 0.01-50 g/L, more preferably 0.05-5 g/L.

The metal surface treatment agent of the present invention preferably further contains a sulfur-containing carbonyl compound.

Specific examples of the sulfur-containing carbonyl compound include thiourea, dimethylthiourea, 1,3-dimethylthiourea, dipropylthiourea, dibutylthiourea, and 1,3-diphenyl-2 -Thiourea, 2,2-xylylthiourea, thioacetamide, sodium dimethyldithiocarbamate, tetramethylthiuram monosulfide, tetrabutylthiuram disulfide, N- Ethyl-N-phenyl dithiocarbamate zinc, dimethyl dithio Zinc carbamate, piperidine salt of pentamethylene dithiocarbamate, zinc diethyldithiocarbamate, sodium diethyldithiocarbamate, zinc isopropylxanthate, ethylidene Compounds containing at least one thiocarbonyl group such as thiosemicarbazide, dimethylxanthogen sulfide, dithioethylenediamine, polydithiocarbamic acid or its salts, etc. These can be used alone or Two or more types can be used in combination.

When the above sulfur-containing carbonyl compound is used, the amount of the compound is considered to be a balance of 0.01 to 100 g/L, more preferably 0.1 to 10 g in the metal surface treatment agent when considering the balance between the corrosion resistance improvement effect and economic efficiency obtained. /L concentration.

The metal surface treatment agent of the present invention preferably further contains a water-soluble resin or a water-dispersible resin.

Specific examples of water-soluble or water-dispersible resins are acrylic resins, epoxy resins, urethane resins, ethylene acrylic acid copolymers, phenol resins, polyester resins, polyolefin resins, alkyds Resins, polycarbonate resins, etc., these can be used alone, two or more kinds can be used in combination, and can also be used by copolymerization.

Examples of water-soluble acrylic resins are copolymers containing acrylic acid and/or methacrylic acid derivatives as main components. Examples of the above derivatives include methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, etc. Copolymers of these and other acrylic monomers can also be used.

In particular, the proportion of acrylic acid and/or methacrylic acid monomers in the copolymer is preferably 70% by mass or more.

The molecular weight of the water-soluble or water-dispersible resin is considered to give full play to the effect of improving the deep drawability of the coating film while setting the viscosity to an appropriate range. When the handleability is good, the weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC) is preferably 10,000 or more, more preferably 300,000 to 2 million.

When the above water-soluble or water-dispersible resin is used, when the amount of the compound is taken into consideration, the effect of improving the bending adhesiveness and the deep-drawing property, and the economic efficiency are considered. In the metal surface treatment agent, it is preferably 0.1~ The concentration of 100g/L is more preferably 5 to 80g/L.

In addition, when a resin is used, in order to improve the film-forming property and form a more uniform and smooth coating film, an organic solvent may be used. Furthermore, a surfactant, a leveling agent, a wettability improver, and a defoaming agent may also be used.

The metal surface treatment agent of the present invention preferably further contains phosphoric acid ions, and by adding it, the corrosion resistance can be further improved.

The addition of the phosphate ion can be carried out by adding a compound capable of generating phosphate ion in water.

Examples of such compounds include phosphates such as phosphoric acid, Na ₃ PO ₄ , Na ₂ HPO ₄ , and NaH ₂ PO ₄ , condensed phosphoric acid, polyphosphoric acid, metaphosphoric acid, diphosphoric acid, and the like, or salts thereof , These can be used alone, and can also be used in combination of two or more.

When using the above-mentioned phosphoric acid ion, the blending amount in the metal surface treatment agent is preferably a concentration of 0.01 to 100 g/L, more preferably a concentration of 0.1 to 10 g/L. When the addition amount is less than 0.01g/L, the corrosion resistance improvement effect may not be sufficient, and if it exceeds 100g/L, the zinc-based plated steel may be excessively etched, resulting in reduced performance. When the water-based resin is included as another component, A condition that causes gelation.

In addition, the metal surface treatment agent of the present invention can also be formulated with tannic acid Conventional additives for various metal surface treatment agents such as salts thereof, phytic acid or salts thereof, etc.

The metal subjected to surface treatment using the metal surface treatment agent of the present invention is not particularly limited, and conventional general metals can be used. Among them, copper, nickel, silver, zinc, iron, aluminum, or alloys thereof are preferably used, and more preferably Aluminum, copper, copper alloy, and various plated steel materials can also be used better.

The surface treatment method using the metal surface treatment agent of the present invention may be a method of applying the above metal surface treatment agent to the metal surface of the object to be coated, and drying the object to be coated after coating, or it may be heated in advance The coated object is then coated with the above metal surface treatment agent and dried by waste heat.

The coating method is not particularly limited, and generally used roll coating, shower coating, spraying, dipping, brush coating, etc. can be used.

In any case, the above drying conditions are preferably room temperature to 250°C for 2 seconds to 1 hour, and more preferably 40 to 180°C for 5 seconds to 20 minutes. If the temperature exceeds 250°C, there is a possibility of deterioration of performance such as adhesion and corrosion resistance.

In the above surface treatment method, when the coating amount of the metal surface treatment agent is taken into consideration, the quality of the coating after drying is preferably 0.1 mg/m ² or more, more preferably 0.5 to 500 mg/ m ² , and more preferably 1 to 250 mg/m ² .

The metal steel material is surface-treated with the metal surface treatment agent of the present invention, dried, and then coated with an upper coating layer to obtain a coated steel material. The metallic steel material may be either pre-coated steel material or post-coated steel material. also, The steel material in the present invention includes the concept of a steel plate.

Examples of the coating layer include a coating system in which a non-chromate primer is applied and dried as needed, followed by a top coat, or a functional coating having functions such as fingerprint resistance and lubricity.

As a non-chromate primer, it can be used for all primers that do not use chromate-based anti-rust pigments in the preparation of the primer.

As such an undercoat, it is preferable to use a vanadic acid-based antirust pigment and a phosphoric acid-based antirust pigment (V/P pigment undercoat), and a calcium silicate-based antirust pigment.

In consideration of the balance of corrosion resistance and processing adhesion, the thickness of the coating film of the above primer is preferably 1 to 20 μm.

The baking and drying conditions of the non-chromate primer can be set to, for example, a metal surface temperature of 150-250° C. and a time of 10 seconds-5 minutes.

The above-mentioned top coat is not particularly limited, and any general top coat for coating can be used.

In addition, the functional coating is not particularly limited, and can be used for all coatings and the like currently applied to chromate-based pretreatment coatings.

The coating methods of the above non-chromate primer coating, top coating and functional coating are not particularly limited, and roll coating, shower coating, gas spray, gasless spray, dipping, etc., which are generally used, can be used.

In addition, the thickness of the top coat can be selected as appropriate, and it can be set to the thickness of the normal coating film according to the type.

[Example]

The following examples and comparative examples illustrate the present invention more specifically, but the present invention is not limited to these examples.

In the following, the following compounds are used as the benzotriazole compound, silane coupling agent, organic titanate, water-dispersible silica, zirconium ion generating compound, sulfur-containing carbonyl compound, water-soluble resin, and phosphate ion generating compound. Commercial products.

[Benzotriazole compound]

A: TT-LYK (2,2’-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]diethanol, manufactured by Chengbei Chemical Industry Co., Ltd.)

B: BT-120 (benzotriazole, manufactured by Chengbei Chemical Industry Co., Ltd.)

[Silane coupling agent]

A: KBE-903 (γ-aminopropyltriethoxysilane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

B: KBM-403 (γ-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

C: KBM-603 (N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

[Organic Titanate]

Titanium tetraisopropoxide (made by Tokyo Chemical Industry Co., Ltd.)

[Water-dispersible silica]

Methanol silica sol (made by Nissan Chemical Industry Co., Ltd.)

[Compounds forming zirconium ions]

Zirconium sol AC-7 (ammonium zirconium carbonate; first rare element chemical industry (stock) system)

[Sulfur-containing carbonyl compound]

Thiourea (Tokyo Chemical Industry Co., Ltd.)

[Water-soluble resin]

Polyacrylic acid (weight average molecular weight 1 million) (Tokyo Chemical Industry Co., Ltd.)

[Compounds that generate phosphate ions]

Phosphoric acid (Tokyo Chemical Industry Co., Ltd. system)

[Example 1]

To a mixed solvent of 500 g of methanol and 500 g of water, 0.5 g of benzotriazole compound A and 9.5 g of silane coupling agent A were added, and stirred at room temperature for 5 minutes to obtain a metal surface treatment agent.

The obtained metal surface treatment agent was coated on a degreased and dried commercial aluminum plate (made by TEST PIECE; 70×150×0.4 mm) with a bar coater No. 20 to a dry film thickness of 10 μm at the metal surface temperature Dry at 105°C for 10 minutes.

Subsequently, a non-chromate primer (manufactured by Nippon Paint Co., Ltd.) containing V/P pigment was coated with a bar coater No. 16 to a dry film thickness of 5 μm, and dried at a metal surface temperature of 215° C. for 5 minutes. Furthermore, FLEKY COAT 1060 (polyester top coating; manufactured by Nippon Paint Co., Ltd.) as a top coat was coated with a bar coater No. 36 to a dry film thickness of 15 μm and dried at a metal surface temperature of 230° C. Breadboard.

[Example 2]

Except that the silane coupling agent A was changed to the silane coupling agent B, a metal surface treatment agent was prepared in the same manner as in Example 1, and a test plate was also produced in the same manner as in Example 1.

[Examples 3 to 10]

Except for the types of benzotriazole compound, silane coupling agent, organic titanate, water-dispersible silica, zirconium ion, sulfur-containing carbonyl compound, water-soluble resin and phosphoric acid ion, they were prepared at the concentrations shown in Table 1. 1 A metal surface treatment agent was prepared in the same manner, and a test plate was produced in the same manner as in Example 1.

[Comparative Examples 1, 2]

A metal surface treatment agent was prepared in the same manner as in Example 1 except that the silane coupling agent was not used and each component shown in Table 1 was prepared at the concentration in Table 1. Further, a test plate was prepared in the same manner as in Example 1.

[Comparative Examples 3-7]

Except that the benzotriazole compound B was used and each component shown in Table 1 was formulated at the concentration in Table 1, a metal surface treatment agent was prepared in the same manner as in Example 1, and a test plate was also prepared in the same manner as in Example 1.

[Comparative Example 8]

In addition to replacing metal surface treatment agents, commercially available coating chromate treatment agents (manufactured by Nippon Paint Co., Ltd.) are applied and dried with chromium adhesion material at 20 mg/m ² , and then a chromium-containing base coat (Japan Except for the paint (product), a test plate was produced in the same manner as in Example 4.

For each test plate obtained in the above examples and comparative examples, the bending adhesion, deep drawability, and corrosion resistance were evaluated according to the following evaluation methods and evaluation criteria. The results are shown in Table 2.

[Evaluation method] (1) Bending tightness

Under a 20°C environment, use a tapered mandrel tester to sandwich a 2 mm Φ spacer between the test plates for 180° bending processing, and perform 3 times of tape peeling at the bending processing portion, and observe the peeling degree with a 20 times magnifying glass, as follows Evaluation criteria Evaluation.

A: Not cracked

B: The processing department is completely cracked

C: The peeling area is less than 20% of the processing department

D: The peeling area is more than 20% of the processing and less than 80%

E: The peeling area is more than 80% of the processed part

(2) Deep drawability

Under a 20°C environment, a cylinder tensile test was carried out under an oil-free condition with a draw ratio: 2.3, a wrinkle suppression pressure: 2 t, a punch R: 5 mm, and a die shoulder R: 5 mm. Subsequently, the peeling width of the coating film from the cross-cut portion was measured and evaluated according to the following criteria.

A: The expansion width is less than 1mm

B: The expansion width is more than 1mm and less than 2mm

C: The expansion width is more than 2mm and less than 3mm

D: The expansion width is more than 3mm and less than 5mm

E: Expansion width is more than 5mm

(3) Corrosion resistance (Cutting section)

After cross-cutting on the test plate and performing a 500-hour salt spray test based on JIS Z 2371, the swelling width on one side of the cut portion was measured, and the following criteria were used for evaluation.

A: The expansion width is 0mm

B: The expansion width is more than 0mm and less than 1mm

C: The expansion width is more than 1mm and less than 3mm

D: The expansion width is more than 3mm and less than 5mm

E: Expansion width is more than 5mm

(End face)

After a 500-hour salt water spray test was performed on the test plate based on JIS Z 2371, the swelling width from the upper burr end surface was evaluated on the same basis as the cut portion.

As shown in Table 2, it can be seen that the coatings formed using the metal surface treatment agents of Examples 1 to 10 exhibit good anti-rust performance and substrate adhesion.

[Example 11]

To a mixed solvent of 500 g of methanol and 500 g of water, 0.1 g of benzotriazole compound A and 9.9 g of silane coupling agent A were added, and stirred at room temperature for 5 minutes to obtain a metal surface treatment agent.

Dipping the copper plate washed with sulfuric acid in the resulting metal surface treatment agent (Made by TEST PIECE; 70×150×0.4 mm) for 1 minute, and dried at a metal surface temperature of 105° C. for 10 minutes to obtain a test plate.

[Example 12]

Except that the silane coupling agent A was changed to the silane coupling agent B, a metal surface treatment agent was prepared in the same manner as in Example 11, and a test plate was produced in the same manner as in Example 11.

[Example 13]

Except that the silane coupling agent A was changed to the silane coupling agent C, a metal surface treatment agent was prepared in the same manner as in Example 11, and a test plate was produced in the same manner as in Example 11.

[Examples 14 to 22]

Except that the types and formulation amounts of the benzotriazole compound and the silane coupling agent were changed as shown in Table 3, a metal surface treatment agent was prepared in the same manner as in Example 11, and a test plate was also prepared in the same manner as in Example 11.

[Comparative Examples 9, 10]

A metal surface treatment agent was prepared in the same manner as in Example 11 except that the silane coupling agent was not used and the compounding amount of the benzotriazole compound was changed to the concentration shown in Table 3. Further, a test plate was prepared in the same manner as in Example 11.

[Comparative Examples 11-14]

Except that the types and formulation amounts of the benzotriazole compound and the silane coupling agent were changed to those shown in Table 3, a metal surface treatment agent was prepared in the same manner as in Example 11, and a test plate was also prepared in the same manner as in Example 11.

For the tests obtained in the above Examples 11-22 and Comparative Examples 9-14 For the panel inspection, heat resistance and corrosion resistance were evaluated according to the following evaluation methods and evaluation criteria. The results are shown in Table 4.

(1) Heat resistance

The test plate was placed in a 150°C thermostat, and the appearance after 1 hour and 5 hours was evaluated according to the following criteria.

A: No change

B: roughly unchanged

C: Redness

D: Severe redness

E: Albino

(2) Corrosion resistance

For the test panel, after performing the salt spray test for 24 hours and 72 hours based on JIS Z 2371, the appearance was evaluated according to the following criteria.

A: No rust occurred

B: Rust occurs in 5~20% area

C: Rust occurs in 29~50% of the area

D: Rust occurs in 50~90% area

E: rust occurred in 90~100% area

As shown in Table 4, the coatings formed using the metal surface treatment agents of Examples 11 to 22 exhibit good heat resistance and rust resistance.

Claims (8)

A metal surface treatment agent characterized by containing a benzotriazole compound represented by the following general formula (1) and a silane coupling agent, the silane coupling agent is a silane coupling agent having an amine group, and the amount of the silane coupling agent used is relatively In the aforementioned benzotriazole compound, the mass ratio is 1 to 50 times,

[In the formula, R ¹ independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ² represents an alkylene group having 1 to 10 carbon atoms; R ³ and R ⁴ independently represent a hydrogen atom and 1 to 10 carbon atoms. Alkyl group, or a group represented by the following general formula (2); but at least one of R ³ and R ⁴ is a group represented by the following formula (2): -R ⁵ -OH (2) (wherein, R ⁵ represents a C 1-10 alkylene group)]. The metal surface treatment agent according to claim 1, wherein the aforementioned R ² is a methylene group, R ³ and R ⁴ are both groups represented by the aforementioned general formula (2), and the aforementioned R ⁵ is an ethylidene group. The metal surface treatment agent according to claim 1 or 2, which contains an organic titanate. The metal surface treatment agent according to claim 1 or 2, which contains water-dispersible silica or organic solvent-dispersible silica. The metal surface treatment agent according to claim 1 or 2, which contains one kind selected from Fe, Zr, Ti, V, W, Mo, Al, Sn, Nb, Hf, Y, Ho, Bi, La, Ce and Zn Compounds of the above metals. A metal surface treatment agent as claimed in claim 1 or 2, which contains a sulfocarbonyl-containing compound. The metal surface treatment agent according to claim 1 or 2, which contains a water-soluble resin or a water-dispersible resin. The metal surface treatment agent according to claim 1 or 2, which contains phosphate ions.