WO2010070728A1 - Surface treating agent for metallic materials - Google Patents

Abstract

Disclosed is a surface treating agent for metallic materials that has various properties such as corrosion resistance and overcoating properties and, when used in coating-type surface treatment, particularly can form a film , which has excellent adhesion to the surface of metallic materials, and can fix, within the film, a component capable of functioning as a corrosion inhibitor for metallic materials. The surface treating agent for metallic materials comprises a silicic acid compound (A), an organoalkoxysilane (B), a metallic compound (C) containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn, at least one compound (D) selected from the group consisting of phosphoric acid compounds and fluoro compounds, water (E), and an alcohol (F) produced upon hydrolysis of the organoalkoxysilan (B). The molar concentration (mol/L) of the alcohol (F) in the treating agent has been regulated in a predetermined range.

Description

Surface treatment agent for metal materials

The present invention relates to a surface treatment agent for a metal material, a surface treatment method using the surface treatment agent for a metal material, and a surface treatment metal material having a film.

In order to obtain anticorrosion or paintability, the metal material is subjected to surface treatment. In other words, surface treatment can suppress the corrosion of metal, prevent the paint film from peeling off when applied, or prevent the corrosion from proceeding even if the paint film is peeled off. is important. Conventionally, as a surface treatment of a metal-based material, a phosphate treatment for depositing a crystal of a metal salt of phosphoric acid or a chromate treatment for forming a film containing hexavalent chromium has been performed.

In the phosphate treatment, first, the metal material is brought into contact with an aqueous solution containing phosphoric acid and metal ions. At this time, the metal is dissolved with an acid, and hydrogen is consumed at the interface of the metal material due to the dissolution reaction, resulting in an increase in pH. Due to the increase in pH, the metal salt of phosphoric acid that can no longer be dissolved is deposited on the surface of the metal material, and a phosphate film is formed. Since the phosphate film is deposited on the dissolution mark on the surface of the metal material, the adhesion with the metal material is very excellent. Furthermore, since a film is formed by a collection of fine crystals, the film is excellent in adhesion with a coated film by an anchor effect due to fine irregularities. Therefore, it is an excellent surface treatment that is still widely used as a base treatment for painting.

However, since it is a so-called reactive surface treatment that originates from bringing a metal into contact with a phosphoric acid-containing acidic aqueous solution and causing a dissolution reaction, the component of the treatment liquid containing phosphoric acid varies depending on the metal material type. was there. Moreover, since the phosphate that could not be deposited on the surface of the metal material floated in the treatment liquid as sludge, it was necessary to remove it. In addition, it is necessary to appropriately change the contact conditions (temperature, time, etc.) between the aqueous solution and the metal material, and further there is a problem that a water washing step (generation of waste water) is required after the surface treatment. Moreover, it could not be applied to a material such as stainless steel having poor reactivity.

There is a reaction type for chromate treatment as well as phosphate, and coating type chromate treatment in which an aqueous solution is applied and dried is well known. The coating-type chromate treatment is a simple method in which an aqueous solution containing hexavalent chromium is applied to the surface of a metal material and dried. Therefore, a washing process is unnecessary after the surface treatment, and a closed system that does not discharge water is used. Moreover, the coating type chromate film has a form in which soluble hexavalent chromium (chromic acid) is retained in the film skeleton based on the polymerization of trivalent chromium. Oxidation action (passivation action, self-healing action) by chromium gives the metal material excellent corrosion resistance. In addition, when applied as a base treatment for coating, it is known that the coating film is hardly peeled off by performing a slight displacement plating of Ni as a pretreatment. One reason for this is that the displacement plating improved the adhesion between the chromate film and the metal surface.

Ideal as a surface treatment for metal materials is an excellent adhesion to the metal material surface, and the film components are polymerized, and there is a soluble corrosion inhibitor in the film, which has been used for a long time. Is to form a film that can be held. In the coating type chromate treatment, a film having the above characteristics is formed.

However, the film formed by the coating-type chromate treatment contains hexavalent chromium, and the hexavalent chromium is eluted by contact with moisture, so that it tends to be avoided from the viewpoints of environment and safety. For this reason, various research and development have been conducted to suppress elution of hexavalent chromium from the chromate film.
However, recently, the existence of hexavalent chromium itself has been disliked, and many developments of non-chromate treatment that does not contain hexavalent chromium have been made.

As the non-chromate treatment, Patent Document 1 discloses a steel sheet having a film formed of a P compound, a Si compound, and a tetravalent vanadium compound. However, with this technique, sufficient adhesion to the surface of the metal material cannot be ensured, and sufficient corrosion resistance cannot be obtained.

In Patent Document 2, a treatment liquid containing a silane coupling agent, a specific resin, a metal complex having four or more Fs, and a metal compound (Mn, Co, Zn, Mg, Ni, Ti, V, Zr) is disclosed. Yes. However, with this technique, sufficient adhesion to the surface of the metal material cannot be ensured, and sufficient corrosion resistance cannot be obtained.

Patent Document 3 discloses an aqueous dispersible material of core / shell composite particles obtained by a reaction operation in which colloidal silica, organoalkoxysilane, and a vinyl monomer having an ethylenically unsaturated group are polymerized. . However, more than 80% of the particles are colloidal silica. This particle is a technique for stably mixing with a resin, and even if it is used as it is, a film cannot be formed and corrosion resistance cannot be obtained.

Patent Document 4 discloses a technique using a composition containing silane and a metal chelate. The metal chelate plays a role of dissolving a metal ion (particularly a cationic state) and a role of binding to the surface of the metal material. However, in this technique, metal ions are chelated to form a form in which metal ions are easily dissolved. As a result, their elution cannot be sufficiently suppressed, and long-term corrosion resistance cannot be obtained.

In Patent Document 5, silane coupling agent 0.01 to 100 g / L, silica 0.05 to 100 g / L, Zr 0.01 to 50 g / L and / or Ti 0.01 to 50 g / L, thiocarbonyl group-containing compound 0 A treatment liquid containing 0.01 to 100 g / L and acrylic resin 0.1 to 100 g / L is disclosed. Since this technique is excellent in adhesion, the paintability is good, but the corrosion resistance at the time of no painting is insufficient. Furthermore, since the treatment liquid gelated with time, it could not be used industrially.

Patent Document 6 discloses a technique using a carboxyl group-containing polyurethane resin, a silane coupling agent, silica, and flaky silica.

Patent Document 7 discloses a technique using a polyurethane resin, a silane coupling agent, and silica. The techniques disclosed in Patent Documents 6 and 7 have not been able to ensure sufficient adhesion to the metal material surface. Further, since silica cannot be sufficiently fixed in the film, sufficient corrosion resistance cannot be obtained.

Patent Document 8 discloses an organic resin film in which a film containing an organic resin and a silane coupling agent is formed in the lower layer and a thiocarbonyl group is contained in the upper layer. The present technology relates to the lower layer in the two-layer process, and the object can be achieved only by the combination with the upper layer. Therefore, as a single film, adhesion to a metal material and corrosion resistance cannot be obtained.

Patent Document 9 discloses a technique using a vanadium compound and Zr, Ti, Mo, W, Mn, and Ce. However, sufficient adhesion between the film formed by this technique and the metal material was not obtained, and elution of the metal compound could not be suppressed.

Patent Document 10 discloses a technique using a silane coupling agent, silica sol, and an aqueous organic resin. In this technique, since the silane coupling agent is bonded to the silica surface, the silica component can be immobilized, but elution of the metal compound cannot be suppressed.

As described above, no surface-treated steel sheet that replaces the chromate film has been obtained by any of the methods, and comprehensively satisfies various characteristics such as corrosion resistance and top coatability. There has been a strong demand for the development of a surface treatment agent capable of producing a surface-treated steel sheet with improved adhesion and suppression of corrosion of metal materials.

JP 2005-48199 A JP 2005-120469 A Japanese Patent No. 3818689 JP-T-2006-519307 JP 2001-316845 A JP 2005-178213 A JP 2005-200777 A Japanese Patent No. 3722658 JP 2002-30460 A JP 2001-98215 A

The present invention has various characteristics such as corrosion resistance and top coatability in a film formed by coating-type surface treatment, and particularly, the formed film has excellent adhesion to the surface of the metal material, and corrosion of the metal material. It is an object of the present invention to provide a surface treatment agent for a metal material that can immobilize a component that acts as an inhibitor in a film, and a surface treatment method using the surface treatment agent for a metal material.

As a result of intensive investigations by paying attention to the properties of organoalkoxysilane, the present inventors use a treatment agent containing a predetermined compound and having a controlled amount of alcohol resulting from hydrolysis of organoalkoxysilane. It has been found that the above problems can be solved.

That is, the present invention provides the following (1) to (9).
(1) Silicic acid compound (A), organoalkoxysilane (B),
A metal compound containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn (C )When,
At least one compound (D) selected from the group consisting of a phosphoric acid compound and a fluorine compound, and water (E),
A surface treatment agent for a metal material containing an alcohol (F) generated by hydrolysis of the organoalkoxysilane (B),
In the treatment agent of alcohol generated when the molar concentration (mol / L) (C _F1 ) in the treatment agent of the alcohol (F) and all alkoxy groups contained in the organoalkoxysilane (B) are hydrolyzed. The surface treatment agent for metal materials, wherein the ratio (C _F1 / C _F2 ) to the molar concentration (mol / L) (C _F2 ) in the range of 0.05 to 0.9 was adjusted.
(2) The surface treatment agent for a metal material according to (1), wherein a mass ratio (C / F) of the alcohol (F) to the metal compound (C) is in a range of 0.01 to 50.
(3) The surface treatment agent for a metal material according to (1) or (2), wherein a mass ratio (D / F) of the alcohol (F) to the compound (D) is 0.01 to 25.
(4) The mass ratio (A / B) between the silicic acid compound (A) and the organoalkoxysilane (B) is 0.01 to 3.0,
The total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the metal compound (C) (C / (A + B)) is 0.01 to 2.0,
The mass ratio (D / (A + B)) between the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the compound (D) is 0.01 to 1.5, (1 ) To (3) The surface treatment agent for metal materials according to any one of the above.
(5) The surface treatment agent for a metal material according to any one of (1) to (4), wherein the organoalkoxysilane (B) has an amino group and / or an epoxy group.
(6) The surface treatment for a metal material according to any one of (1) to (5), further comprising at least one compound (G) selected from the group consisting of a water-soluble polymer and an aqueous emulsion resin. Agent.
(7) The mass ratio (G / (A + B)) between the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) in the treating agent and the compound (G) is 0.01-0. The surface treatment agent for a metal material according to (6), which is .3.
(8) The surface treatment agent for a metal material according to any one of (1) to (7) is applied on the surface of the metal material, dried by heating, and the film amount is 2 to 1000 mg / m ² as the Si adhesion amount Is formed on the surface of the metal material.
(9) A surface-treated metal material having a film on the surface, obtained by the method for treating a metal material according to (8).

The present invention has various performances such as excellent corrosion resistance and top coatability in a film formed by a coating type surface treatment, and in particular, the formed film has excellent adhesion to the surface of a metal material. Provided are a surface treatment agent for a metal material capable of immobilizing a component acting as a corrosion inhibitor in the film, and a surface treatment method using the surface treatment agent for the metal material.

Below, the surface treatment agent for metal materials which concerns on this invention, and the surface treatment method using the surface treatment agent for metal materials are demonstrated.
First, the surface treatment agent for metal material will be described in detail.

<Surface treatment agent for metal materials>
The surface treatment agent for a metal material of the present invention includes a silicic acid compound (A), an organoalkoxysilane (B), Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W A metal compound (C) containing at least one metal element selected from the group consisting of Nb, Cr, and Zn, a compound (D) selected from the group consisting of a phosphate compound and a fluorine compound, and water (E ) And an alcohol (F) produced by hydrolysis of the organoalkoxysilane (B). Furthermore, in the alcohol treating agent produced when the molar concentration (mol / L) (C _F1 ) in the treating agent of alcohol (F) and all alkoxy groups contained in the organoalkoxysilane (B) are hydrolyzed. The ratio (C _F1 / C _F2 ) to the molar concentration (mol / L) (C _F2 ) is adjusted in the range of 0.05 to 0.9.
First, various components constituting the surface treatment agent for a metal material will be described.

<Silic acid compound (A)>
The surface treatment agent for a metal material of the present invention contains a silicate compound (A). By using a silicic acid compound, it is possible to form a film excellent in various properties such as corrosion resistance, top coatability, heat resistance, weldability, and continuous workability.
The silicic acid compound is mainly composed of silicon and oxygen, and the kind thereof is not particularly limited. For example, alkali silicates such as sodium silicate, potassium silicate and lithium silicate, colloidal silica, liquid phase silica and silicon chloride obtained by sols by removing sodium, potassium or lithium from these silicates by ion exchange method Examples include a dispersion in which vapor-phase silica prepared by burning and oxidizing in water is dispersed in water, and a hydrolyzate of alkoxysilane. Among these, colloidal silica and liquid phase silica are preferable in that the performance of the obtained film is more excellent.

For example, as liquid phase silica, Snowtex C, Snowtex CS, Snowtex CM, Snowtex O, Snowtex OS, Snowtex OM, Snowtex NS, Snowtex N, Snowtex NM, Snowtex S, Snowtex 20 , Snowtex 30, Snowtex 40, Adelite AT-20N, Adelite AT-20A, Adelite AT-20Q, etc. Also, Snowtex UP, Snowtex OUP, Snowtex PS- processed into special chain shape S, Snotex PS-SO, Snotex PS-M, Snotex PS-MO, Snotex PS-L, Snotex PS-LO, and the like.
Examples of the fine-particle silica called vapor phase silica include Aerosil 50, Aerosil 130, Aerosil 200, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil MOX80, Aerosil MOX170, and the like dispersed in water can also be used. .

The content of the silicic acid compound (A) in the surface treatment agent for metal materials is not particularly limited, but it is a treatment from the viewpoint that the corrosion resistance, top coatability, heat resistance, weldability, and continuous workability of the resulting film are more excellent. The amount is preferably from 0.1 to 70% by weight, more preferably from 1 to 50% by weight, based on the total solid content in the agent. In addition, the total solid content in the treatment agent means a solid component constituting a film described later, and does not include a solvent or the like.

<Orgoxyalkoxysilane (B)>
The surface treatment agent for a metal material of the present invention contains organoalkoxysilane (B). By using together the organoalkoxysilane (B) and the above-described silicic acid compound (A), a film having a three-dimensional structure by a siloxane bond between the silicic acid compound (A) and the organoalkoxysilane (B) is formed. Thereby, it is presumed that the corrosion resistance, top coatability, heat resistance, weldability, continuous workability, grounding property, adhesion to the metal material surface, and the like of the obtained film were improved.

The organoalkoxysilane used in the present invention is not particularly limited. For example, tetramethoxysilane, tetraethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, methyltriethoxy Silane, cyclohexylmethyldimethoxysilane, n-hexyltrimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, decyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, isobutyltri Methoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4-epoxy Cycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyl Methyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, p-styryl Trimethoxysilane, γ-acryloxypropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, bis (triethoxysilylpropyl) (Lopyl) tetrasulfide, γ-isocyanatopropyltriethoxysilane, γ-triethoxysilylyl-N- (1,3-dimethyl-butylidene) propylamine, N- (vinylbenzylamine) -β-aminoethyl-γ-amino And propyltrimethoxysilane.
Of these, trialkoxysilane having 3 mol of an active alkoxy group is preferred because the alcohol concentration can be easily adjusted.

Moreover, it is preferable that the organoalkoxysilane (B) has at least one functional group selected from an amino group and an epoxy group. By having these functional groups in the organoalkoxysilane (B), the siloxane bond between the silicon compound (A) and the organoalkoxysilane (B) is further promoted, and a film having a dense three-dimensional cross-link is formed. Presumed to be. As a result, the film can fix more components that act as corrosion inhibitors for the metal material, and the corrosion resistance is further improved.

One preferred embodiment of the organoalkoxysilane includes a compound represented by the following general formula (I).

In general formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, an acryloxy group, a ureido group, an isocyanate group, and a vinyl group. L represents a divalent linking group or a simple bond. R represents an alkyl group or a hydrogen atom. n represents an integer of 1 to 3.

In general formula (I), X represents any functional group selected from the group consisting of an epoxy group, an amino group, a mercapto group, an acryloxy group, a ureido group, an isocyanate group, and a vinyl group. Of these, an epoxy group and an amino group are preferable. When n is 2 or more, X may be the same or different.

In general formula (I), L represents a divalent linking group or a simple bond.
Examples of the linking group represented by L include an alkylene group (preferably having 1 to 20 carbon atoms), —O—, —S—, an arylene group, —CO—, —NH—, —SO ₂ —, —COO. -, -CONH-, or a combination thereof. Of these, an alkylene group is preferable. In the case of a simple bond, it means that X in the general formula (I) is directly connected to Si (silicon atom).
When n is 2 or more, L may be the same or different.

In general formula (I), each R independently represents an alkyl group (preferably having 1 to 4 carbon atoms) or a hydrogen atom.

In the general formula (I), n represents an integer of 1 to 3. Of these, 1 is preferable.

The organoalkoxysilane (B) may be a hydrolyzate in which a part of the alkoxy group is hydrolyzed.

The content of the organoalkoxysilane (B) in the surface treating agent for metal materials is not particularly limited, but the corrosion resistance, top coatability, heat resistance, weldability, continuous workability, grounding property, metal material surface of the resulting film From the standpoint of better adhesion to the treatment agent, it is preferably 0.1 to 70% by mass, more preferably 1 to 50% by mass, based on the total solid content in the treatment agent.

<Metal compound (C)>
The surface treatment agent for a metal material of the present invention is selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn. A metal compound (C) containing at least one metal element is included. By using a metal compound (C) in combination with a phosphoric acid compound and / or a fluorine compound described later, a hardly soluble salt is formed in the film. This hardly soluble salt promotes a crosslinking reaction between the silicon compound (A) and the organoalkoxysilane (B), and a film having a dense network structure is formed. It is assumed that the working metal compound (C) can be easily fixed in the film.
The metal compound (C) is not particularly limited as long as it contains the metal element, and examples thereof include nitrates, acetates, phosphates, sulfates, ammonium salts and fluorides containing the metal.

Specific examples of the metal compound (C) include Zr-containing metal compounds such as zirconium nitrate, zirconium oxynitrate, zirconyl acetate, zirconyl sulfate, zirconyl ammonium carbonate, zirconyl potassium carbonate, zirconyl sodium carbonate, and zirconia sol. Can be mentioned. Moreover, the zirconic acid and its salt which are produced by ion-exchange and alkali neutralizing the aqueous solution of a water-soluble zirconium salt are also mentioned.

Examples of the metal compound containing Ti include titanyl sulfate, titanyl nitrate, titanium nitrate, titanyl chloride, titanium chloride, titania sol, titanium oxide, potassium oxalate titanate, titanium lactate, titanium tetraisopropoxide, titanium acetylacetonate, Examples include diisopropyltitanium bisacetylacetone. Moreover, metatitanic acid obtained by thermally hydrolyzing an aqueous solution of titanyl sulfate, orthotitanic acid obtained by alkali neutralization, and salts thereof are also included.

Examples of the metal compound containing Co include cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt phosphate, cobalt chloride, cobalt oxide, and cobalt hydroxide.

Examples of the metal compound containing Fe include iron sulfate, iron nitrate, iron chloride, iron phosphate, iron oxide, iron hydroxide, and iron powder.

Examples of the metal compound containing V include vanadium pentoxide, ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride, vanadium trioxide, vanadium dioxide, vanadium oxysulfate, vanadium oxyacetylacetonate, vanadium acetylacetonate, 3 Examples thereof include vanadium chloride, phosphovanadomolybthenic acid, and vanadium sulfate.

Examples of the metal compound containing Ce include cerium nitrate, cerium acetate, cerium chloride, and cerium sol.

Examples of the metal compound containing Mo include ammonium molybdate, sodium molybdate, potassium molybdate, and ammonium molybdate.

Examples of metal compounds containing Mn include potassium permanganate, ammonium permanganate, sodium permanganate, permanganate, manganese sulfate, manganese nitrate, manganese oxide, manganese carbonate, manganese chloride, manganese phosphate, and the like. Is mentioned.

Examples of the metal compound containing Mg include magnesium sulfate, magnesium nitrate, magnesium carbonate, magnesium phosphate, magnesium chloride, magnesium oxide, and magnesium hydroxide.

Examples of the metal compound containing Al include aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum nitrate, aluminum phosphate, and aluminum chloride.

Examples of the metal compound containing Ni include nickel oxide, nickel hydroxide, nickel sulfate, nickel nitrate, nickel phosphate and nickel chloride.

Examples of the metal compound containing Ca include calcium oxide, calcium hydroxide, calcium sulfate, calcium nitrate, calcium phosphate, and calcium chloride.

Examples of the metal compound containing W include ammonium metatungstate, sodium metatungstate, potassium metatungstate, paratungstic acid, ammonium paratungstate, and sodium paratungstate.

Examples of the metal compound containing Nb include niobium oxalate, niobium oxide, and niobium sol.

Examples of the metal compound containing Cr include trivalent chromium, such as chromium sulfate, chromium nitrate, chromium chloride, chromium hydroxide, chromium oxide, and chromium phosphate.

Examples of the metal compound containing Zn include zinc oxide, zinc hydroxide, zinc sulfate, zinc nitrate, zinc chloride, zinc phosphate, and acetyl zinc. In addition, since zinc is an amphoteric metal, alkali is used. Examples thereof include sodium zincate and potassium zincate produced on the side.

Among these, it is more preferable to include at least one or more selected from metal compounds containing Zr, V, Al, or Zn, and salts thereof from the viewpoint that the effect of improving corrosion resistance is high.

The content of the metal compound (C) in the surface treatment agent for metal materials is not particularly limited, but it is 0 with respect to the total solid content in the treatment agent from the viewpoint of better corrosion resistance and grounding properties of the obtained film. 0.05 to 50% by mass is preferable, and 0.1 to 30% by mass is more preferable.

<Phosphate compound and / or fluorine compound>
The surface treatment agent for a metal material of the present invention contains at least one compound (D) selected from the group consisting of a phosphoric acid compound and a fluorine compound. As described above, the phosphoric acid compound and / or the fluorine compound promotes the crosslinking reaction between the silicon compound (A) and the organoalkoxysilane (B) when used in combination with the metal compound (C). Furthermore, since the phosphoric acid compound and / or fluorine compound etches the base metal to form a film bonded to the surface of the base material, the corrosion resistance of the film and the adhesion to the metal material surface are further improved. Guessed.

Examples of the phosphoric acid compound include ammonium salts and metal salts of phosphoric acid (metals include, for example, alkali metals, V, Co, W, Ti, Zr, Al, and Zn); condensed phosphoric acids such as pyrophosphoric acid An organic phosphoric acid compound having phytic acid, a phosphonic group, or a phosphine group; For example, phosphoric acid, metaphosphoric acid, pyrophosphoric acid, orthophosphoric acid, triphosphoric acid, tetraphosphoric acid, and ammonium salts, aluminum salts, magnesium salts, nitrilotrismethylenephosphonic acid, nitrilotrispropylenephosphonic acid, nitrilodiethylmethylenephosphone Acid, nitrilopropyl bismethylenephosphonic acid methane, 1-hydroxymethane-1,1-diphosphonic acid and the like.
A phosphoric acid compound is used individually or in combination of 2 or more types.

Examples of the fluorine compound include hydrofluoric acid, its ammonium salt, its alkali metal salt; tin fluoride, manganese fluoride, ferrous fluoride, ferric fluoride, aluminum fluoride, zinc fluoride, fluorine Metal fluorides such as vanadium fluoride; acid fluorides such as fluorine oxide, acetyl fluoride, and benzoyl fluoride.
More preferably, one having at least one element selected from the group consisting of Ti, Zr, Hf, Si, Al and B is suitably used. Specifically, for example, (TiF ₆ ) ²⁻ , (ZrF ₆ ) ²⁻ , (HfF ₆ ) ²⁻ , (SiF ₆ ) ²⁻ , (AlF ₆ ) ³⁻ , (BF ₄ OH) ^−, etc. Examples include complexes in which 1 to 3 hydrogen atoms are added to anions, ammonium salts of these anions, metal salts of these anions, and the like. More specifically, titanium hydrofluoric acid, zircon hydrofluoric acid, silicohydrofluoric acid and the like can be mentioned.
A fluorine compound is used individually or in combination of 2 or more types.

The total content of the compound (D) in the surface treatment agent for metal materials is not particularly limited, but from the viewpoint that the corrosion resistance of the resulting film is more excellent, 0.01 to about 0.01 to the total solid content in the treatment agent 40% by mass is preferable, and 0.1 to 30% by mass is more preferable.

<Water (E)>
The surface treatment agent for a metal material of the present invention contains water (E).
The content of water in the surface treatment agent for a metal material is not particularly limited, but is preferably 30 to 99% by mass, and preferably 40 to 95% with respect to the total amount of the treatment agent from the viewpoint of easier handling of the treatment agent. The mass% is more preferable.

<Alcohol (F)>
The surface treatment agent for a metal material of the present invention contains alcohol (F) produced by hydrolysis of the organoalkoxysilane (B) described above. Alcohol is generated from the hydrolysis reaction of the organoalkoxysilane (B) having an alkoxy group.
The type of alcohol depends on the type of alkoxy group of the organoalkoxysilane used, and examples thereof include methanol, ethanol, and propanol.

The molar concentration (mol / L) (C _F1 ) of the alcohol (F) contained in the surface treatment agent for a metal material of the present invention is a treatment agent obtained when all alkoxy groups contained in the organoalkoxysilane are hydrolyzed. In relation to the molar concentration (mol / L) (C _F2 ) of the alcohol in the solvent, it is adjusted so as to satisfy C _F1 / C _F2 = 0.05 to 0.9, preferably 0.1 to 0.8 Fulfill.
When the molar concentration ratio (C _F1 / C _F2 ) is less than 0.05, the effect of the reactive functional group required for the silicic acid compound (A) and the organoalkoxysilane (B) to form a siloxane bond is organo Since it is lost from the alkoxysilane (B), the corrosion resistance of the coating, the top coatability, and the adhesion between the formed coating and the metal material surface are reduced. Further, when the molar concentration ratio (C _F1 / C _F2 ) exceeds 0.9, the effect of the reactive functional group is high, so that a siloxane bond is formed between the organoalkoxysilanes (B), and serves as a corrosion inhibitor for metal materials. The working components cannot be fixed in the film.

The method for adjusting the molar concentration (mol / L) (C _F1 ) of alcohol derived from the alkoxy group of the organoalkoxysilane (B) is not particularly limited. For example, a solution in which a silanol condensation catalyst and water are mixed with an organoalkoxysilane. , A method of adjusting the concentration by controlling the amount of alcohol produced as a by-product, a method of adjusting the concentration by removing alcohol and water produced as a by-product, and the like.
The alcohol concentration measurement method is not particularly limited, and examples thereof include chromatographic methods such as gas chromatography and ion chromatography, and nuclear magnetic resonance spectroscopy.

The mass ratio (C / F) between the metal compound (C) and the alcohol (F) in the surface treatment agent for a metal material of the present invention preferably satisfies 0.01 to 50. It is more preferable to satisfy 1 to 40. If it is in the above-mentioned range, the component that acts as a corrosion inhibitor for the metal material is easily fixed in the film, which is preferable in that the resulting film is more excellent in corrosion resistance, top coatability, and adhesion to the metal material surface.

Furthermore, the mass ratio (D / F) of the compound (D) to the alcohol (F) in the surface treatment agent for a metal material of the present invention preferably satisfies 0.01 to 25, preferably 0.1 to 20 It is more preferable to satisfy the above condition, and it is more preferable to satisfy 0.1 to 15. If it is within the above range, the component that acts as a corrosion inhibitor of the metal material is easily fixed in the film, which is preferable in that the resulting film has better corrosion resistance, top coatability, and adhesion to the metal material surface.

The mass ratio (A / B) between the silicic acid compound (A) and the organoalkoxysilane (B) in the surface treatment agent for a metal material of the present invention is preferably 0.01 to 3.0, 0.05 ~ 2.5 is more preferred. If it is less than 0.01, the continuous processability may decrease, and if it exceeds 3.0, the adhesion between the formed film and the surface of the metal material may decrease.

The mass ratio (C / (A + B)) of the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the metal compound (C) in the surface treatment agent for a metal material of the present invention is 0. 0.01 to 2.0 is preferable, and 0.05 to 1.5 is more preferable. If it is less than 0.01, the corrosion resistance of the film may be reduced, and if it exceeds 2.0, the adhesion between the film and the metal material surface may be reduced along with the decrease in the corrosion resistance of the film.

The mass ratio (D / (A + B)) of the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the compound (D) in the surface treatment agent for a metal material of the present invention is 0.00. It is preferably from 01 to 1.5, more preferably from 0.05 to 1.0. If it is less than 0.01, the corrosion resistance of the film may decrease, and if it exceeds 1.5, the corrosion resistance of the film, the grounding property, the adhesion between the film and the metal material surface decreases, and In some cases, the component acting as a corrosion inhibitor is hardly fixed in the film.

<Other additives>
Various additives may be included in the surface treatment agent for a metal material according to the present invention as necessary. Below, the contained additive is demonstrated.

<Water-soluble polymer and / or water-based emulsion resin>
The surface treatment agent for a metal material of the present invention may contain at least one compound (G) selected from the group consisting of a water-soluble polymer and an aqueous emulsion resin. By adding this compound (G), the fingerprint resistance and lubricity of the film are improved.
The type of the water-soluble polymer and / or water-based emulsion resin is not particularly limited. For example, water-soluble polymers such as polyacrylic acid, polymethacrylic acid, polyacrylamide, and polyvinyl alcohol, and acrylic resin dispersed in water are used. , Urethane resin, epoxy resin, polyester resin, polyamide resin, polyolefin resin, ethylene-acrylic resin, polybutyral resin, polyacetal resin, fluorine resin, and the like.

Content of the compound (G) in the surface treating agent for metal materials is not specifically limited.
In particular, the mass ratio (G / (A + B)) of the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) in the treating agent to the compound (G) is 0.01 to 0.3. Preferably, it is 0.05 to 0.25. If it is less than 0.01, the fingerprint resistance and lubricity of the film may not be improved, and if it exceeds 0.3, the corrosion resistance and heat resistance of the film may be reduced.

The surface treatment agent for metal material of the present invention may contain a silanol condensation catalyst. The silanol condensation catalyst is not particularly limited. For example, formic acid, acetic acid, butyric acid, oxalic acid, succinic acid, lactic acid, L-ascorbic acid, tartaric acid, citric acid, DL-malic acid, malonic acid, maleic acid, phthalic acid Nitrilotrismethylenephosphonic acid, nitrilotrispropylenephosphonic acid, nitrilodiethylmethylenephosphonic acid, nitrilopropylbismethylenephosphonic acid methane, methane-1-hydroxy-1,1-diphosphonic acid, ethane-1-hydroxy-1,1- Examples include diphosphonic acid, propane-1-hydroxy-1,1-diphosphonic acid, sulfonic acid, benzenesulfonic acid, ketimine compound, aldimine compound, enamine compound, oxazolidine compound, and aminoalkylalkoxysilane.

The surface treatment agent for metal material of the present invention may contain a rust preventive additive containing N. Examples of these include ethylenediamine, triethylamine, urea, guanidine and the like.

The surface treatment agent for a metal material of the present invention may contain an additive (lubricant) for improving lubricity, if necessary. By improving the lubricity of the film, it can effectively prevent wrinkling on the film and reduce damage to the film during processing.
Examples of the additive include solid lubricants such as polyethylene wax, oxidized polyethylene wax, oxidized polypropylene wax, carnauba wax, paraffin wax, montan wax, rice wax, Teflon (registered trademark) wax, carbon disulfide, and graphite. Among these solid lubricants, one or more kinds can be used.

To the surface treatment agent for metal materials of the present invention, alcohol, ketone, cellosolve-based water-soluble solvent, surfactant, antifoaming agent, leveling agent, antibacterial and antifungal agent, coloring agent, etc. are added as necessary. May be. By these, the drying property, application | coating external appearance, workability | operativity, storage property, and designability of a processing agent can be improved. However, it is important to add them to such an extent that the quality obtained in the present invention is not impaired, and at most it is several mass% in the treatment liquid.

The pH of the surface treatment agent for a metal material of the present invention may be acidic or alkaline as long as the treatment liquid can be produced stably. However, when the pH is less than 0.5, the reactivity with the metal material may increase and the appearance may deteriorate, and when it exceeds 14, the stability of the metal compound decreases and the stability of the treatment agent itself. Is unfavorable because of lowering.

The surface treatment agent for a metal material of the present invention may contain a solvent (for example, alcohol) other than the water as necessary.

The method for preparing the surface treatment agent for a metal material of the present invention is not particularly limited. For example, a silicic acid compound (A), an organoalkoxysilane (B), a metal compound (C), a phosphoric acid compound and / or a fluorine compound (D), and water (E) are sufficiently mixed using a stirrer such as a mixing mixer. It can manufacture by mixing.

<Surface treatment method>
The surface treatment method using the surface treatment agent for metal material of the present invention is not particularly limited, but the above-described surface treatment agent for metal material is applied on the surface of the metal material, dried by heating, and the coating amount is set as the Si adhesion amount. A surface treatment method in which a film of 2 to 1000 mg / m ² is formed on the surface of the metal material is preferable.
The surface treatment method will be described below.

Prior to application, the metal material may be pretreated for the purpose of removing oil and dirt on the surface of the metal material, if necessary. Metallic materials are often coated with rustproof oil for rustproofing purposes. Moreover, even when not coated with rust preventive oil, there are oil and dirt adhered during the work. By performing the pretreatment, the surface of the metal material is cleaned, and the surface of the metal material is easily wetted uniformly by the metal material surface treatment agent of the present invention. In the case where there is no oil or dirt and the surface of the material is uniformly wetted with the surface treatment agent for a metal material of the present invention, the pretreatment process is not particularly necessary.
The pretreatment method is not particularly limited, and examples thereof include hot water washing, solvent washing, and alkaline degreasing washing.

The metal material to be used is not particularly limited, but a hot dip galvanized steel sheet (GI), an alloyed hot dip galvanized steel sheet (GA) obtained by alloying the same, and a hot dip Zn-5% Al alloy plated steel sheet (GF). ), Hot dip zinc-55% aluminum alloy plated steel sheet (GL), electrogalvanized steel sheet (EG), electrogalvanized Ni alloy plated steel sheet (Zn—Ni), aluminum plating, and aluminum sheet. Moreover, it is applicable also to the iron plate which has not plated.

As a method for applying the surface treatment agent for a metal material to a metal material, an optimum method is appropriately selected depending on the shape of the metal material to be treated, and examples thereof include a roll coating method, a dipping method, and a spray coating method.
More specifically, for example, in the case of a sheet form, the coating amount is adjusted by spraying a roll or gas at a high pressure by spraying a treatment liquid onto a metal material or a treatment liquid. If it is a molded product, it may be dipped in the treatment liquid and pulled up, and in some cases, the excess amount of the treatment liquid may be blown away with compressed air to adjust the coating amount.

The heating temperature for drying the coating film formed on the surface of the metal material is preferably 40 to 250 ° C, more preferably 60 to 200 ° C, and particularly preferably 60 to 180 ° C. If it is lower than 40 ° C., the water that is the main solvent of the treatment agent of the present invention remains, so that the metal compound cannot be fixed or the corrosion resistance of the film is lowered. When it exceeds 250 ° C., the film tends to crack, and the corrosion resistance may be lowered. The heating and drying method is not particularly limited, and the treatment agent may be dried by heating with hot air, an induction heater, infrared rays, near infrared rays, or the like.
The heating time is appropriately selected depending on the type of compound in the surface treatment agent for metal material used. Among these, from the viewpoint of productivity and the like, 0.1 to 60 seconds is preferable, and 1 to 30 seconds is more preferable.

The coating amount of the coating formed on the surface of the metal material is adjusted so that the Si adhesion amount is 2 to 1000 mg / m ² , preferably 10 to 800 mg / m ² , more preferably 20 to 500 mg / m 2. ² . When the amount is less than 2 mg / m ² , the effect of the present invention may not be sufficiently obtained. When the amount exceeds 1000 mg / m ² , the effect is saturated and economically disadvantageous. Corrosion resistance may be reduced.

On the film formed by the above surface treatment method, an organic polymer film is formed so that the film thickness after drying becomes 0.1 to 3.0 μm, and further higher corrosion resistance, fingerprint resistance and lubricity Can be granted. As such an organic polymer film, a known resin emulsion such as acrylic, urethane, or epoxy, or a material added with silica, a rust preventive agent, a lubricant, an ultraviolet absorber, a pigment, or the like can be used.

By performing the surface treatment of the metal material using the above-described surface treatment agent for metal material, it has corrosion resistance, top coating property, heat resistance, weldability, continuous workability, grounding property, fingerprint resistance, and particularly formed. It is possible to form a surface-treated film that has excellent adhesion to the surface of the metal material and can immobilize a component that acts as a corrosion inhibitor for the metal material in the film.
The surface-treated metal material obtained by using the surface treatment agent for a metal material of the present invention can be applied to various uses. Examples thereof include materials used in various fields such as architecture, electricity, and automobiles.

Next, the effects of the present invention will be described with reference to examples and comparative examples. However, the present examples are merely examples for explaining the present invention, and do not limit the present invention.

1. Test plate preparation method (1) Test material (material)
The following commercially available materials were used as test materials.
(I) Electrogalvanized steel sheet (EG): thickness 0.8 mm, basis weight = 20/20 (g / m ² )
(Ii) Hot-dip galvanized steel sheet (GI): thickness 0.8 mm, basis weight = 60/60 (g / m ² )
(Iii) Alloyed hot-dip galvanized steel sheet (GA): thickness 0.8 mm, basis weight = 40/40 (g / m ² )
The basis weight indicates the basis weight on the main surface of each steel plate. For example, in the case of an electrogalvanized steel sheet, it is 20/20 (g / m ² ), which means that each surface of the steel sheet has a plating of 20 g / m ² .

(2) Pretreatment (cleaning)
As a method for preparing a test piece, first, the surface of the above-mentioned test material was treated with Palclean N364S manufactured by Nihon Parkerizing to remove oil and dirt on the surface. Next, after rinsing with tap water and confirming that the surface of the metal material was 100% wet with water, pure water was further poured, and water removed from the oven in a 100 ° C. atmosphere was used as a test plate.

(3) Preparation of treatment liquid of the present invention Each component was mixed in water with the composition shown in Table 1 (solid content mass ratio) to obtain a treatment liquid.
In addition, the compounding quantity of component (A), (B), (C), (D), and (G) in Table 1 represents the quantity (g) mix | blended in 1 kg of surface treatment liquids for metal materials. . The content of the alcohol component (F) is measured using gas chromatography, C _F2 is calculated from the content of the organoalkoxysilane, and is expressed as the following molar concentration ratio (C _F1 ) / (C _F2 ). .

Hereinafter, the compounds used in Table 1 will be described.

<Silicon compound (A)>
A1: Snowtex C (manufactured by Nissan Chemical Industries)
A2: Snowtex O (manufactured by Nissan Chemical Industries)

<Orgoxyalkoxysilane (B)>
B1: γ-glycidoxytriethoxysilane B2: aminopropyltriethoxysilane B3: vinyltriethoxysilane B4: tetraethoxysilane

<Metal compound (C)>
C1: ammonium zirconium carbonate C2: vanadium acetylacetonate C3: magnesium nitrate C4: aluminum nitrate C5: zinc oxide

<Compound (D)>
D1: Phosphoric acid D2: 1-hydroxymethane-1.1-diphosphonic acid D3: titanium hydrofluoric acid D4: zircon hydrofluoric acid

<Alcohol concentration (molar concentration ratio) (C _F1 ) / (C _F2 )>

<Compound (G)>
G1: Acrylic resin (Polysol AM-2386, Showa Polymer Co., Ltd.)

(4) Treatment method Using the above-described surface treatment solution for metal materials, the coating is applied on each test plate by the following coating method, and then placed in an oven as it is without being washed with water, and the drying shown in Table 2 is performed. The film was dried at a temperature to form a film having the film amount shown in Table 2.
The drying temperature was adjusted by the atmospheric temperature in the oven and the time in the oven. The drying temperature indicates the temperature reached on the test plate surface. Specific methods of bar coat coating and roll coat coating are as follows.

Bar coat coating: The treatment solution was dropped onto the test plate and painted with a # 3-5 bar coater. It adjusted so that it might become a predetermined | prescribed film quantity with the count of the bar coater used and the density | concentration of a process liquid.
Roll coat coating: The test plate was immersed in the treatment liquid at room temperature for about 1 second and taken out, and then the excess liquid was cut with a roll to adjust the coating amount. It adjusted so that it might become the predetermined | prescribed film quantity with the amount of draining with a roll, and the density | concentration of a process liquid.

(5) Evaluation Test Method (5-1) Corrosion Resistance Evaluation The surface-treated test plate was cut out to 70 × 150 mm, the back surface and the end were sealed with vinyl tape, and the following tests were performed. In the evaluation, the rust generation area ratio was visually evaluated and evaluated.
Salt spray test (SST: according to JIS-Z-2371):
The white rust generation area ratio after 120 hours of SST was visually evaluated according to the following criteria.
Cycle test (CCT (JASO): M609-91 (automobile material corrosion test method)):
The white rust generation area ratio after 30 cycles of CCT was visually evaluated according to the following criteria.
Judgment criteria:
◎: Rust generation area ratio less than 10% ○: Rust generation area ratio of 10% or more and less than 20% △: Rust generation area ratio of 20% or more and less than 40% ×: Rust generation area ratio of 40% or more XX: Rust generation on the entire surface

(5-2) Evaluation of adhesion to metal material Method A: A stainless steel round bar with a diameter of 40 mm and a mirror-polished surface is reciprocated 10 times on the surface of a test plate surface-treated with a load of 50 kg, and the tape is peeled off. Then, substitution plating was performed with an aqueous copper sulfate solution (3% aqueous solution, immersed at room temperature for 5 seconds), and the degree of peeling of the film was evaluated.
Method B: Extrude the test plate surface-treated by Erichsen Extruder 7mm, peel the entire extruded part with cello tape (registered trademark), and perform displacement plating with copper sulfate aqueous solution (3% aqueous solution, room temperature, 5 seconds immersion) Then, the degree of peeling of the film was evaluated.
Judgment criteria:
◎: No peeling ○: Very slight point peeling △: Slight peeling ×: Remarkable peeling

(5-3) Evaluation of dissolution property of metal compound The surface-treated test plate was immersed in boiling water of pure water for 2 hours, and the residual amount of the metal compound was measured with a fluorescent X-ray analyzer. From the adhesion amount of the metal compound measured before the test, the metal fixation rate was calculated.
Fixing rate (%) = residual amount (mg / m ² ) / adhesion amount before test (mg / m ² ) × 100
Judgment criteria:
A: 95% to 100%
○: 90% or more and less than 95% △: 60% or more and less than 90% ×: 20% or more and less than 60% XX: less than 20%

(5-4) Evaluation of top coatability A commercially available melamine alkyd paint was applied on the surface-treated test plate and baked at 160 ° C. so that the coating thickness was 20 μm. Then, after being immersed in boiling water for 2 hours, 100 squares of 1 mm square were cut with an NT cutter, the part was extruded 6 mm with an Erichsen extruder, peeled off with tape, and the remaining state of the coating film was evaluated by the following evaluation.
Judgment criteria:
◎: Less than 5% peeling No peeling ○: Less than 10% peeling 5% or less △: Less than 20% to 10% peeling ×: Less than 60% peeling 20% or less XX: 60% peeling or more Corrosion resistance test: NT on test plate The incision reaching the material in the X shape was made with a cutter, and the rust generation state after 80 cycles of the CCT (cycle test) was evaluated according to the following criteria.
Judgment criteria:
◎: Less than 1 mm from the cut ○: From 1 mm to less than 2 mm from the cut Δ: From 2 mm to less than 5 mm from the cut ×: 5 mm or more from the cut XX: Film peeling occurred

With respect to the surface-treated metal materials obtained using the surface treatment agents for metal materials described in Examples 1 to 51 and Comparative Examples 52 to 67, the evaluations (5-1) to (5-4) above were performed. The results are shown in Table 3.
From a practical point of view, it is necessary that “x” and “xxx” are absent in the above evaluation items.

As shown in Table 3, the treatment agent of the present invention containing a predetermined compound and having an alcohol molar concentration ratio (C _F1 ) / (C _F2 ) adjusted is excellent in corrosion resistance and top coatability, and further formed. It was confirmed that the coated film had excellent adhesion to the surface of the metal material, and the elution of components that act as corrosion inhibitors for the metal material was suppressed.
In particular, from the comparison of Examples 23 to 26, it was found that when the organoalkoxysilane having an epoxy group or amino group was used as the organoalkoxysilane (B), each characteristic was more excellent. Further, from comparison between Examples 16 and 17, it was found that when two kinds of organoalkoxysilanes were used in combination, each characteristic was further improved.
On the other hand, in the comparative example, a result that comprehensively satisfies various characteristics was not obtained.

Claims (9)

1. Silicic acid compound (A), organoalkoxysilane (B),
   Metal compound containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn (C )When,
   At least one compound (D) selected from the group consisting of a phosphoric acid compound and a fluorine compound, and water (E),
   A surface treatment agent for a metal material containing an alcohol (F) generated by hydrolysis of the organoalkoxysilane (B),
   In the treatment agent of alcohol generated when the molar concentration (mol / L) (C _F1 ) in the treatment agent of the alcohol (F) and all alkoxy groups contained in the organoalkoxysilane (B) are hydrolyzed. The surface treatment agent for metal materials, wherein the ratio (C _F1 / C _F2 ) to the molar concentration (mol / L) (C _F2 ) in the range of 0.05 to 0.9 was adjusted.
2. The surface treatment agent for a metal material according to claim 1, wherein a mass ratio (C / F) of the alcohol (F) and the metal compound (C) is 0.01 to 50.
3. The surface treatment agent for a metal material according to claim 1 or 2, wherein a mass ratio (D / F) of the alcohol (F) to the compound (D) is in a range of 0.01 to 25.
4. The mass ratio (A / B) of the silicic acid compound (A) and the organoalkoxysilane (B) is 0.01 to 3.0,
   The total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the metal compound (C) (C / (A + B)) is 0.01 to 2.0,
   The mass ratio (D / (A + B)) between the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the compound (D) is 0.01 to 1.5. The surface treatment agent for a metal material according to any one of 1 to 3.
5. The surface treatment agent for a metal material according to any one of claims 1 to 4, wherein the organoalkoxysilane (B) has an amino group and / or an epoxy group.
6. The surface treatment agent for a metal material according to any one of claims 1 to 5, further comprising at least one compound (G) selected from the group consisting of a water-soluble polymer and an aqueous emulsion resin.
7. The mass ratio (G / (A + B)) between the total mass (A + B) of the silicic acid compound (A) and the organoalkoxysilane (B) and the compound (G) is 0.01 to 0.3. 6. The surface treatment agent for metal materials according to 6.
8. A surface treatment agent for a metal material according to any one of claims 1 to 7 is applied onto the surface of the metal material, dried by heating, and a film having a coating amount of 2 to 1000 mg / m ² as a Si adhesion amount is applied to the surface of the metal material A surface treatment method of a metal material formed on the surface.
9. A surface-treated metal material having a film on the surface, obtained by the method for surface treatment of a metal material according to claim 8.