JP5528924B2 - Metal surface treatment agent, surface treatment metal material, and metal surface treatment method - Google Patents

Description

  The present invention relates to a metal surface treatment agent not containing chromium, a surface treatment metal material obtained by using the treatment agent, and a metal surface treatment method.

Conventionally, as steel plates represented by steel plates for home appliances, steel plates that have been chromated with a chromate surface treatment agent containing hexavalent chromium as a main component have been widely used for the purpose of improving corrosion resistance.
On the other hand, a problem that environmental pollution is caused by the toxicity of hexavalent chromium has been pointed out. In recent years, many non-chromate surface treatment techniques using a metal surface treatment agent not containing chromium have been proposed as a solution.

  For example, Patent Document 1 includes “at least one vanadium compound (A) and a metal compound (B) containing at least one metal selected from the group consisting of zirconium, titanium, molybdenum, tungsten, and manganese”. Metal surface treatment agent ”, and examples of the“ vanadium compound (A) ”include ammonium metavanadate, vanadium oxyacetylacetonate, and the like.

  Further, Patent Document 2 discloses that “(A) peroxovanadate, (B) titanium compound and / or zirconium compound, and (C) water-soluble or water-dispersible organic resin, if necessary, a metal surface treatment composition. "(A) peroxovanadate" is disclosed that it is produced by reacting ammonium metavanadate with hydrogen peroxide.

  Furthermore, in Patent Document 3, 5 to 30 parts by weight of a silane compound having an epoxy group and a silane compound having an amino group or a hydrolysis condensate thereof based on 100 parts by weight of the total solution, and 0.1 to 0.1 of a vanadium compound 5 parts by weight, 0.1 to 5 parts by weight of magnesium compound, 1 to 10 parts by weight of organic / inorganic acid, 0.05 to 2 parts by weight of crosslinking accelerator and coupling agent, and 0.01 to 1 of antifoaming agent A chromium-free low-temperature curing metal surface treatment composition comprising parts by weight, 1 to 2 parts by weight of a wetting agent, and the balance consisting of water and ethanol is disclosed.

JP 2002-30460 A JP 2009-174051 A JP 2008-544088 A

  A film obtained from a metal surface treatment agent is required to have various performances such as corrosion resistance, heat resistance, electrical conductivity, and resistance to black residue during processing. In recent years, when metal materials are used in the field of general-purpose home appliances such as precision equipment, OA equipment, white goods, etc., in particular, the required level regarding conductivity and heat resistance is increasing in addition to corrosion resistance.

  The present inventor conducted further studies on metal surface treatment agents containing vanadium compounds such as ammonium metavanadate and vanadium oxyacetylacetonate used in Patent Documents 1 and 2, and obtained from this metal surface treatment agent. It has become clear that the corrosion resistance, heat resistance and electrical conductivity of the resulting film have not reached the level required recently, and need to be improved.

  On the other hand, when this inventor further examined also about the metal surface treating agent containing a silane compound as disclosed by patent document 3, the storage stability of a treating agent and this metal surface treating agent are obtained. Various characteristics of the film (for example, corrosion resistance, heat resistance, black residue resistance, etc.) have not always reached a level that is practically satisfactory.

  As described above, it is difficult to say that a conventionally known metal surface treatment agent can form a film excellent in heat resistance, conductivity, corrosion resistance, and black residue, which can be used as a substitute for a chromate film. Therefore, there has been a strong demand for the development of a metal surface treatment agent excellent in storage stability that can satisfy these requirements comprehensively.

  In view of the above circumstances, an object of the present invention is to provide a metal surface treatment agent excellent in storage stability, which can obtain a film excellent in heat resistance, conductivity, corrosion resistance, and black residue resistance. .

As a result of intensive studies to solve the above problems, the present inventor has found that the vanadium compound in the film is eluted in a corrosive environment as a cause of deterioration of the corrosion resistance in the prior art. Based on these findings, the present inventor provides a hydrolyzate of vanadium alkoxide represented by a predetermined structural formula and / or a condensate thereof (A), and a predetermined metal oxide colloid (B). By using a metal surface treating agent contained in a predetermined amount, it was clarified that a film excellent in corrosion resistance, conductivity and heat resistance can be obtained, and the present invention was completed.
That is, the present invention provides the following (1) to (8).

(1) Vanadium alkoxide hydrolyzate and / or its condensate (A) represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group), Al, Si, Ti, A metal oxide colloid (B) containing an oxide of a metal element selected from the group consisting of Y, Zr, Nb, Sn, La, Ce and Nd, and a hydrolyzate of the vanadium alkoxide and / or a condensation thereof. things metal V converted mass (W _a) of (a), the mass ratio of the mass (W _B) of the metal oxide colloid _{(B) (W a / W} B) is at 0.005 to 5.0 , Metal surface treatment agent.

  (2) The metal surface treatment agent according to (1), wherein the hydrolyzate of vanadium alkoxide and / or its condensate (A) has a weight average molecular weight of 100 to 3000.

  (3) The metal surface treating agent according to (1) or (2), wherein the pH is 2 to 11.

  (4) A surface-treated metal comprising: a metal material; and a film obtained by heating and drying the metal surface treatment agent according to any one of (1) to (3) applied on the surface of the metal material. material.

  (5) The surface-treated metal material according to (4), wherein the metal material is a zinc-based plated steel sheet.

(6) The surface-treated metal material according to (4) or (5), wherein the mass of the film obtained by the heat drying is 0.05 to 3 g / m ² .

  (7) An application step of applying the metal surface treatment agent according to any one of (1) to (3) on the surface of the metal material, and the metal surface treatment agent applied on the surface of the metal material. A metal surface treatment method comprising: a heat drying step of obtaining a film by heat drying.

  (8) The metal surface treatment method according to (7), wherein the heat drying temperature in the heat drying step is 50 to 200 ° C.

  ADVANTAGE OF THE INVENTION According to this invention, the metal surface treating agent excellent in the storage stability which can obtain the film | membrane excellent in heat resistance, electroconductivity, corrosion resistance, and black residue can be provided.

<Metal surface treatment agent>
The metal surface treatment agent of the present invention comprises a hydrolyzate of vanadium alkoxide represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group) and / or a condensate thereof (A), A metal oxide colloid (B) containing an oxide of a metal element selected from the group consisting of Al, Si, Ti, Y, Zr, Nb, Sn, La, Ce and Nd, and hydrolysis of the vanadium alkoxide The mass ratio (W _A / W _B ) between the metal V equivalent mass (W _A ) of the product and / or its condensate (A) and the mass (W _B ) of the metal oxide colloid ( _B ) is 0.005. It is a metal surface treating agent which is -5.0.
Hereinafter, the components of the metal surface treatment agent of the present invention will be described.

[Hydrolyzate of vanadium alkoxide and / or condensate thereof (A)]
The vanadium alkoxide used in the present invention is a compound represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group).
The vanadium alkoxide is hydrolyzed in the presence of water, and a compound represented by the general formula VO (OR) ₂ OH in which a part of the alkoxy group is substituted with a hydroxyl group, or all of the alkoxy group is substituted with a hydroxyl group. And other compounds. When a film is obtained from a metal surface treatment agent containing a hydrolyzate and / or a condensate obtained through hydrolysis and condensation of such a compound, amorphous vanadium oxide can be formed.
By including amorphous vanadium oxide obtained by using the vanadium alkoxide as a starting material in the film, it is considered that both corrosion resistance and conductivity, which are normally in a trade-off relationship, can be achieved at a high level.

In general, in amorphous vanadium oxide, the valence of vanadium is close to pentavalent, and the conduction mechanism is that electrons flow from a slightly present tetravalent vanadium ion to a pentavalent vanadium ion. It is said that it is hopping conduction caused by. For this reason, amorphous vanadium oxide exhibits high conductivity.
On the other hand, in the case of crystalline vanadium oxide, the valence of vanadium is pentavalent, and the hopping conduction caused by the difference in valence between vanadium is prevented, so that the conductivity is deteriorated.

The vanadium alkoxide has an alkoxy group and a hydroxy group by hydrolysis. Both the alkoxy group and the hydroxy group are electron donating groups. Therefore, it is considered that the vanadium alkoxide is in a state where tetravalent vanadium is easily formed, and promotes hopping conduction between V ^{4+ and} V ⁵⁺ .

R in the general formula VO (OR) ₃ each independently represents an alkyl group, and is preferably an alkyl group having 1 to 8 carbon atoms, and an alkyl group having 1 to 4 carbon atoms from the viewpoint of ease of handling and availability. More preferred. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. R may be the same or different.

  Specific examples of the vanadium alkoxide include vanadium oxytriisopropoxide, vanadium oxytributoxide, vanadium oxytriethoxide, vanadium oxytriisobutoxide, etc. Among them, the heat resistance, corrosion resistance and conductivity of the resulting film Therefore, vanadium oxytriisopropoxide and vanadium oxytributoxide are preferable.

The conditions for the hydrolysis / condensation reaction of vanadium alkoxide are not particularly limited. For example, by performing the hydrolysis-condensation reaction in a solvent (such as water), a hydrolyzate having a desired weight average molecular weight or a condensate thereof (hydrolysis) Decomposition condensate). More specifically, first, V—OH (hydroxyl group) is generated by a hydrolysis reaction. Next, if the hydrolysis reaction proceeds sufficiently, the production of V—O—V by the condensation reaction is also rapidly performed, leading to an increase in the weight average molecular weight.
Since the hydrolysis reaction and the condensation reaction are affected by temperature and time, it is preferable to adjust the reaction temperature and reaction time as necessary to achieve the target weight average molecular weight.

The reaction temperature for the hydrolysis / condensation reaction is preferably from 0 to 70 ° C., more preferably from 20 to 40 ° C., from the viewpoint of easy reaction control.
The reaction time for the hydrolysis / condensation reaction is appropriately selected depending on the compound used, but is preferably 5 to 60 minutes from the viewpoint of productivity.
The hydrolysis / condensation reaction may be performed in a solvent as necessary. Examples of the solvent used include water and organic solvents such as alcohols (such as methanol), ketones, and cellosolves that partially contain water.
The pH of the reaction system during the hydrolysis / condensation reaction is not particularly limited, and an optimum range is appropriately selected according to the compound to be used and the target weight average molecular weight.

  The weight average molecular weight of the hydrolyzate of vanadium alkoxide and / or its condensate (A) is preferably 100 to 3000, and more preferably 200 to 1000. When the weight average molecular weight is within this range, the molecular weight is appropriate, so that the storage stability of the treatment agent is good and various film properties are also good. If the weight average molecular weight is too high, sufficient storage stability of the treatment agent may not be obtained, and various characteristics of the film such as corrosion resistance may be slightly inferior.

  The amount of the vanadium alkoxide, which is a starting material in the metal surface treatment agent of the present invention, is not particularly limited. However, from the viewpoint of the corrosion resistance of the film and the storage stability of the treatment agent, the amount of the vanadium alkoxide is 0. It is preferable that it is 05-20 mass%, and it is more preferable that it is 0.1-10 mass%.

  The content of the hydrolyzate and / or its condensate (A) in the metal surface treatment agent of the present invention is not particularly limited, but from the viewpoint of the corrosion resistance of the film and the storage stability of the treatment agent, the total amount of the treatment agent In contrast, the metal V (vanadium) equivalent mass is preferably 0.01 to 5 mass%, and more preferably 0.02 to 2 mass%.

[Metal oxide colloid (B)]
The metal oxide colloid (B) is a colloidal metal containing an oxide of at least one metal element selected from the group consisting of Al, Si, Ti, Y, Zr, Nb, Sn, La, Ce and Nd It is an oxide. That is, the metal oxide colloid (B) is a colloid containing an oxide of the metal element.

In the metal surface treatment agent of the present invention, the metal oxide colloid (B) coexists with the hydrolyzate of vanadium alkoxide and / or its condensate (A), whereby the heat resistance and conductivity of the resulting film are obtained. Corrosion resistance can be further improved.
In particular, with regard to the improvement of conductivity, the conductivity has been increased through the above-described hopping conduction by coexisting vanadium oxide having a valence of pentavalent and a tetravalent or lower atom having a lower valence than that. Conceivable. Further, regarding the improvement of heat resistance, it is considered that the heat resistance has increased due to the stability of the metal oxide to heat.

  Furthermore, in the obtained film, V (vanadium element) derived from the vanadium alkoxide and the metal element M derived from the metal oxide colloid (B) are mediated by oxygen such as VOM. Since a part of the network is formed, elution of V (vanadium element) contributing to corrosion resistance can be suppressed even in a corrosive environment, and the corrosion resistance is considered to be improved.

The metal oxide colloid (B) contains an oxide of at least one metal element selected from the group consisting of Al, Si, Ti, Y, Zr, Nb, Sn, La, Ce and Nd. Specific examples of the metal oxide contained include, for example, aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), titanium oxide (TiO ₂ ), yttrium oxide (Y ₂ O ₃ ), and zirconium oxide (ZrO). ₂ ), niobium oxide (Nb ₂ O ₅ ), tin oxide (SnO), lanthanum oxide (La ₂ O ₃ ), cerium oxide (CeO ₂ ), and neodymium oxide (Nd ₂ O ₃ ). Of these, silicon oxide, titanium oxide, and zirconium oxide are preferred from the viewpoint that the various properties such as corrosion resistance, conductivity, and heat resistance of the resulting film are more excellent.
The metal oxide colloid may contain only one type of metal element oxide or two or more types of metal element oxides. Further, the content ratio of the metal element oxide in the metal oxide colloid (B) is not particularly limited, but it is preferably substantially composed of the metal element oxide. In addition, substantial means about 99-100 mass%.

  The average particle size of the metal oxide colloid (B) is not particularly limited, but is preferably from 0.1 to 100 nm, and more preferably from 1 to 50 nm, from the viewpoint that various properties such as corrosion resistance of the resulting film are more excellent.

When producing the metal surface treating agent of the present invention containing the metal oxide colloid (B), a sol (metal oxide sol) in which the metal oxide colloid is dispersed in a solvent can also be used.
Specific examples of the metal oxide sol include alumina sol, silica sol, titanium oxide sol, yttrium oxide sol, zirconium oxide sol, niobium oxide sol, tin oxide sol, lanthanum oxide sol, cerium oxide sol, neodymium oxide sol, and the like.
Of these, silica sol, titanium oxide sol, and zirconium oxide sol are preferred because of their superior heat resistance, corrosion resistance, and black residue.
The solvent in the metal oxide sol is not particularly limited, but may be water, an organic solvent such as ethanol or isopropyl alcohol, or a mixture thereof.
In addition, the solid content of the metal oxide colloid in the metal oxide sol is not particularly limited, and is preferably 1 to 50% by mass with respect to the total sol amount from the viewpoint of handleability.

The metal oxide colloid (B) may be synthesized by a known method, or the above-mentioned commercially available product (metal oxide sol) may be used.

  The amount of the metal oxide colloid (B) charged in the metal surface treatment agent of the present invention is not particularly limited, but it is 0 with respect to the total amount of the treatment agent from the viewpoint of the corrosion resistance of the film and the storage stability of the treatment agent. It is preferable that it is 1-20 mass%, and it is more preferable that it is 1-10 mass%.

[Mass ratio (W _A / W _B )]
In the metal surface treatment agent of the present invention, the metal V (vanadium) equivalent mass (W _A ) of the hydrolyzate and / or condensate (A) of the vanadium alkoxide used and the metal oxide colloid (B) The mass ratio (W _A / W _B ) to the mass (W _B ) is 0.005 to 5.0. The metal V (vanadium) equivalent mass (W _A ) is the metal V (vanadium) equivalent of the mass of the hydrolyzate and / or its condensate (A) in the metal surface treatment agent.
When the mass ratio (W _A / W _B ) is less than 0.005, corrosion resistance cannot be obtained, and the effect of hopping conduction by the vanadium alkoxide hydrolyzate and / or its condensate (A) is reduced. Therefore, conductivity is inferior. On the other hand, when the mass ratio (W _A / W _B ) exceeds 5.0, the heat resistance, corrosion resistance, and black residue resistance are inferior.
On the other hand, when the mass ratio (W _A / W _B ) is 0.005 to 5.0, a film excellent in heat resistance, conductivity, corrosion resistance, and black residue resistance can be obtained. Especially, it is preferable that it is 0.025-2.5 at the point which the effect of this invention is more excellent, and it is preferable that it is 0.05-0.5.

[PH]
The metal surface treatment agent of the present invention preferably has a pH of 2 to 11 and more preferably 4 to 9.
If the pH is within this range, the metal material is not excessively etched in the process from the application of the metal surface treatment agent to the metal material until the film is formed by drying or heat treatment, and the appearance of the resulting metal material is It becomes good. Moreover, if pH is this range, the storage stability of a metal surface treating agent is also favorable.
If the pH is too low, the appearance of the metal material may be partially impaired, and if the pH is too high, the storage stability of the treatment agent may not be obtained.

A conventionally known pH adjusting agent for adjusting the pH can be used. Examples include phosphoric acid, hydrofluoric acid, nitric acid, formic acid, acetic acid, lactic acid, glycolic acid, phosphonic acid, citric acid, tartaric acid, ammonia, sodium hydroxide, monoethanolamine, diethanolamine, triethanolamine, and ethylenediamine. .
Of these, acetic acid and ammonia are preferable from the viewpoint of storage stability and etching effect.

[solvent]
The metal surface treatment agent of the present invention may contain a solvent, and the solvent is mainly water, but an alcohol, ketone, cellosolve-based water-soluble organic solvent is added as necessary, for example, to improve the drying property of the film. An aqueous medium may be used.
The amount of solvent in the metal surface treatment agent of the present invention is not particularly limited, but is preferably 1 to 99% by mass, more preferably 30 to 95% by mass, and more preferably 50 to 90% by mass with respect to the total amount of the treatment agent. % Is particularly preferred.

[Additive]
The metal surface treatment agent of the present invention includes an alkoxy group-containing metal compound, a water-soluble inorganic compound, a water-soluble organic resin, a wax, a pigment, a surfactant, and an antifoaming agent as long as the spirit and film performance of the present invention are not impaired. Additives such as leveling agents can be added.

[Method for preparing metal surface treatment agent]
The method for preparing the metal surface treating agent of the present invention is not particularly limited, and can be produced by a known method. For example, it can be produced by adding a predetermined amount of the metal oxide colloid (B) to a solution containing the hydrolyzate of vanadium alkoxide and / or its condensate (A) and mixing them.

<Surface-treated metal material>
The surface-treated metal material of the present invention is a surface-treated metal material comprising a metal material and a film obtained by heating and drying the metal surface treatment agent of the present invention applied on the surface of the metal material.

Examples of the metal material include iron, an alloy mainly composed of iron, aluminum, an alloy mainly composed of aluminum, copper, an alloy mainly composed of copper, and a plated metal material obtained by plating these metal materials. Among these, a zinc-based plated steel sheet is preferable.
Zinc-coated steel sheets include galvanized steel sheets, zinc-nickel plated steel sheets, zinc-iron plated steel sheets, zinc-chromium plated steel sheets, zinc-aluminum plated steel sheets, zinc-titanium plated steel sheets, zinc-magnesium plated steel sheets, zinc-manganese. Examples thereof include a plated steel sheet, a zinc-aluminum-magnesium plated steel sheet, and a zinc-aluminum-magnesium-silicon plated steel sheet.
In addition, as the zinc-based plated steel sheet, the plating layer in the above-described zinc-based plated steel sheet includes cobalt, molybdenum, tungsten, nickel, titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, A material containing cadmium, arsenic, or the like as a small amount of a different metal element or an impurity; a material in which an inorganic material such as silica, alumina, titania or the like is dispersed;
Furthermore, as the zinc-based plated steel sheet, a multilayer plated steel sheet combining the above-described zinc-based plating and other types of plating (for example, iron plating, iron-phosphorus plating, nickel plating, cobalt plating, etc.) can also be used. .
The plating method is not particularly limited, and a known plating method such as an electroplating method, a hot dipping method, a vapor deposition plating method, a dispersion plating method, a vacuum plating method, or the like can be used.

Mass of the film obtained by heating and drying the metal surface treatment agent of the present invention is preferably 0.05 to 3 g / m ^2, and more preferably 0.1 to 1.5 g / m ² .
When the film mass is within this range, the surface of the metal material is sufficiently coated to exhibit various performances, the film is hard to break, heat resistance is improved, and corrosion resistance is further improved.

<Metal surface treatment method>
The metal surface treatment method of the present invention includes a coating step of coating the metal surface treatment agent of the present invention on the surface of the metal material, and heat drying the metal surface treatment agent of the present invention coated on the surface of the metal material. And a heat drying step for obtaining a film.
In addition, before apply | coating the metal surface treating agent of this invention, you may degrease the surface of the said metal material as needed.

  The application means in the application step is not particularly limited, and examples thereof include commonly used roll coat, shower coat, air spray, airless spray, curtain flow coat, brush coating, and dipping.

The heat drying step is performed without washing the metal material after the coating step. Examples of the heat drying means in the heat drying step include a dryer, a hot air furnace, a high frequency induction heating furnace, and an infrared furnace.
The heating and drying temperature in the heating and drying step is preferably 50 to 200 ° C, and more preferably 60 to 150 ° C. If the heating and drying temperature is within this range, the moisture evaporation rate is fast and the drying efficiency is better, and the improvement in the performance of the resulting film can be expected.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Preparation of metal surface treatment agent>
Vanadium alkoxide was added to distilled water, stirred at 25 ° C. for 10 minutes, and the pH was adjusted to produce a hydrolyzate and its condensate. A predetermined amount of metal oxide colloid was added to the solution according to the mixing ratio shown in Table 1 described later, and the mixture was stirred for 30 minutes to obtain a predetermined metal surface treatment agent.

The weight average molecular weight of the hydrolyzate of vanadium alkoxide and / or its condensate (A) in the obtained metal surface treatment agent was determined using gel filtration chromatography (GFC). The measurement conditions for GFC are shown below.
・ Analyzer: TRI ROTAR-V (JASCO)
Detector: differential refractometer 830-RI (JASCO), cell temperature 50 ° C.
-Column thermostat: TU-100 (JASCO), temperature 55 ° C
Guard column: OHpak Q-800P (shodex), inner diameter 8 mm × 50 mm
Column: OHpak Q-802 (shodex), inner diameter 8 mm × 500 mm
-Eluent: distilled water-Flow rate: 0.7 mL / min
・ Standard materials: diethylene glycol, polyethylene glycol

<Composition of metal surface treatment agent>
Table 1 shows the types of each component used for the preparation of the metal surface treatment agent, the metal V equivalent mass (W _A ) of the hydrolyzate of vanadium alkoxide and / or its condensate ( _A ) and the metal oxide colloid (B mass) (W _B) and the mass ratio of (W _a / W _B), the weight average molecular weight of the vanadium alkoxide hydrolyzate and / or condensate (a), and shows the pH of the metal surface treatment agent. In Table 1, the mass% of vanadium alkoxide and metal oxide colloid (B) represents the charged amount (mass%) relative to the total amount of the processing agent.
Specific names of the components corresponding to the symbols shown in Table 1 are shown below.

Vanadium alkoxide A1: Vanadium oxytriisopropoxide A2: Vanadium oxytributoxide A3: Ammonium metavanadate A4: Vanadium oxyacetylacetonate A5: Vanadium diisopropoxybis (acetylacetonate)

・ Metal oxide colloid (B)
B1: Alumina sol (manufactured by Nissan Chemical Industries, Ltd., trade name: alumina sol 200, solid content mass: 10% by mass, pH 5)
B2: Silica sol (manufactured by Nissan Chemical Industries, Ltd., trade name: Snowtex O, colloidal particle size: 10 nm, solid content mass: 20% by mass, pH 3)
B3: Titanium oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Tynock A-6, colloid particle size: 10 nm, solid content mass: 6% by mass, pH 10)
B4: Yttrium oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Bayal Y-10C, solid content mass: 10% by mass, pH 11)
B5: Zirconium oxide sol (manufactured by Nissan Chemical Industries, Ltd., trade name: Nanouse ZR-30AL, solid content mass: 30% by mass, pH 3)
B6: Niobium oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Bayal Nb-X10, solid content mass: 10% by mass, pH 6)
B7: Tin oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Cerames S-8, colloidal particle size: 2 nm, solid content mass: 8 mass%, pH 10)
B8: Lanthanum oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Bayal La-C10, solid content mass: 10% by mass, pH 9.5)
B9: Cerium oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Niedral U-15, solid content mass: 15 mass%, pH 3.5)
B10: Neodymium oxide sol (manufactured by Taki Chemical Co., Ltd., trade name: Viral Nd-C10, solid content mass: 10% by mass, pH 9)

PH adjuster C1: Phosphate C2: Monoethanolamine C3: Acetic acid C4: Ammonia

<Metal surface treatment method>
A hot dip galvanized steel sheet with a thickness of 0.6 mm (60 g / m ² adhesion amount per side) is used as the metal material, and after alkali degreasing and washing with water, the prepared metal surface treatment agent is applied to one side of the plated steel sheet. It was applied with a coater and dried by heating to prepare a surface-treated metal material. Table 1 shows the film mass and the heating temperature (PMT: maximum plate temperature) of the formed film.
The obtained surface-treated metal material was evaluated by the following method.

<Evaluation method>
(1) Heat resistance A test piece of a surface-treated metal material was heated at 300 ° C. for 20 minutes, and a color difference ΔE before and after heating (E value difference in Hunter color system) was measured and evaluated as follows.
◎: Less than 1 ○: 1 or more, less than 2 △: 2 or more, less than 3 ×: 3 or more

(2) Conductivity Using a test piece of a surface-treated metal material, a load at which the surface resistance was 10 ⁻³ Ω or less was evaluated with a four-probe surface resistance measuring device as follows.
・ Measuring device: Loresta GP (Mitsubishi Chemical)
・ Probe: ASP
◎: Less than 100 g ○: 100 g or more, less than 250 g Δ: 250 g or more, less than 500 g ×: 500 g or more

(3) Plane portion corrosion resistance Using a test piece of an unprocessed surface-treated metal material, evaluation was performed as follows based on a white rust generation area ratio after 240 hours of salt spraying based on JIS-Z-2371.
◎: Less than 5% ○: 5% or more, less than 10% △: 10% or more, less than 50% ×: 50% or more

(4) Corrosion resistance after alkaline degreasing Using an unprocessed surface-treated metal material test piece, an alkaline degreasing agent CL-N364S (manufactured by Nihon Parkerizing Co., Ltd.) (20 g / L, 60 ° C., 10 seconds spray, spray pressure 0.5 kg) / Cm < ² >), spray water washing was performed for 10 seconds, and then the white rust generation area ratio after 120 hours of salt water spraying based on JIS-Z-2371 was evaluated as follows.
◎: Less than 5% ○: 5% or more, less than 10% △: 10% or more, less than 50% ×: 50% or more

(5) Processed part corrosion resistance Using an unprocessed surface-treated metal material test piece, Erichsen 7 mm extrusion was performed, and then the white rust generation area rate after 120 hours of salt spraying based on JIS-Z-2371 It was evaluated as follows.
◎: Less than 5% ○: 5% or more, less than 10% △: 10% or more, less than 50% ×: 50% or more

(6) Corrosion resistance after heating After heating for 20 minutes at 300 ° C. using a test piece of unprocessed surface-treated metal material, the area ratio of white rust generated after 120 hours of salt spraying based on JIS-Z-2371 Evaluation was performed as follows.
◎: Less than 5% ○: 5% or more, less than 10% △: 10% or more, less than 50% ×: 50% or more

(7) Black residue resistance In the high-speed deep drawing test, the degree of black residue when processed at a drawing ratio of 2.0 was calculated from the L value before and after the test, and evaluated as follows.
○: Less than 1.0 Δ: 1.0 or more, less than 2.0 ×: 2.0 or more

(8) Storage stability Storage stability was evaluated as follows in the period until gelatinization and precipitation generate | occur | produce when a metal surface treating agent was left still at 40 degreeC atmosphere.
○: More than 1 month ×: Less than 1 month

Table 1 shows the evaluation results. In addition, in the evaluation result of each Example of Table 1, it is practically preferable that it is (circle) or (double-circle).
From the evaluation results shown in Table 1, it was found that Examples 1 to 24 were excellent in heat resistance, conductivity, corrosion resistance, black residue resistance during processing, and storage stability.

Also, looking at the Examples 1-6, the weight ratio (W _A / W _B) is Example 1-3 is 0.005 to 0.05 is more excellent heat resistance, the mass ratio (W _A / W _B) It turned out that Examples 4-6 which are 0.50-5.0 are excellent by electroconductivity.
Moreover, when Example 7-10 was seen, it turned out that the outstanding effect is acquired in the wide pH range of a processing agent.
Moreover, when Examples 11-14 were seen, it turned out that the outstanding effect is acquired in various film | membrane masses.

  In addition, when Examples 15 to 24 are viewed, Examples 16, 17, and 19 using B2 (silica sol), B3 (titanium oxide sol), and B5 (zirconium oxide sol) are superior in heat resistance, conductivity, and corrosion resistance. I understood.

On the other hand, from the evaluation results shown in Table 1, it was found that Comparative Example 1 containing no vanadium alkoxide could not obtain the barrier property and hopping conduction effect of the film, and both the corrosion resistance and conductivity were inferior.
The mass ratio (W _A / W _B) is Comparative Example 2 is less than the lower limit of the scope of the present invention (0.005-5.0) are inferior in corrosion resistance, furthermore, the effect of hopping conduction is reduced It was found that the conductivity was inferior.
Further, Comparative Example 3 in which the mass ratio (W _A / W _B ) exceeded the upper limit of the range (0.005 to 5.0) of the present invention is excellent in heat resistance, black residue resistance, storage stability and corrosion resistance. I found it inferior.
Moreover, it turned out that the comparative example 4 which does not contain a metal oxide colloid (B) is inferior to heat resistance, corrosion resistance, and black residue resistance.
In Comparative Examples 5 to 7, where the vanadium alkoxide is A3 (ammonium metavanadate), A4 (vanadium oxyacetylacetonate), or A5 (vanadium diisopropoxybis (acetylacetonate)), the barrier properties of the film It was also found that the hopping conduction effect was not obtained and the conductivity, corrosion resistance, and black residue resistance were inferior.
As can be seen from the results of Comparative Examples 1 and 4, when the hydrolyzate of vanadium alkoxide and / or its condensate (A) or the metal oxide colloid (B) is contained alone, both are corrosion resistant. Inferior to On the other hand, it was found that when both were used in combination, the corrosion resistance was excellent and there was a synergistic effect.

Claims (8)

A hydrolyzate of vanadium alkoxide and / or a condensate thereof (A) represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group);
A metal oxide colloid (B) containing an oxide of a metal element selected from the group consisting of Al, Si, Ti, Y, Zr, Nb, Sn, La, Ce and Nd,
The mass ratio of the mass (W _B) of the vanadium alkoxide hydrolyzate and / or condensate and metal V converted mass of _(A) (W A), the metal oxide colloid (B) (W _A / W Metal surface treatment agent whose _B ) is 0.005-5.0.   The metal surface treating agent according to claim 1, wherein the hydrolyzate of vanadium alkoxide and / or the condensate thereof (A) has a weight average molecular weight of 100 to 3,000.   The metal surface treating agent according to claim 1 or 2, wherein the pH is 2-11.   A surface-treated metal material comprising: a metal material; and a film obtained by heating and drying the metal surface treatment agent according to any one of claims 1 to 3 applied on the surface of the metal material.   The surface-treated metal material according to claim 4, wherein the metal material is a zinc-based plated steel sheet. The mass of the heat dried coating obtained is a 0.05 to 3 g / m ^2, the surface treated metal material according to claim 4 or 5.   An application step of applying the metal surface treatment agent according to any one of claims 1 to 3 on the surface of the metal material; and heating and drying the metal surface treatment agent applied on the surface of the metal material to form a film. A metal surface treatment method comprising: a heat drying step to obtain.   The metal surface treatment method of Claim 7 whose heat drying temperature in the said heat drying process is 50-200 degreeC.