JP5438536B2 - 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, and a surface treatment metal material and a metal surface treatment method using the same.

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 technologies have been proposed as solutions to satisfy the required performance such as conductivity, corrosion resistance, adhesion of top coat, heat resistance, storage stability, etc. using metal surface treatment agents that do not contain chromium. ing.

  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”. (See paragraph [0008]), and examples of the “vanadium compound (A)” include ammonium metavanadate and vanadium acetylacetonate (see paragraph [0012]).

  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. In which “(A) peroxovanadate” is produced by reacting ammonium metavanadate with hydrogen peroxide (see paragraphs [0014] and [0015]). .

  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

  The film obtained from the metal surface treatment agent is required to have various performances such as adhesion to top coat and heat resistance as described above. In recent years, when using metal materials in the field of general-purpose home appliances such as precision equipment, OA equipment, and white goods home appliances, in particular, in addition to corrosion resistance, the level of demand for electrical conductivity is increasing from the viewpoint of antistatic.

When this inventor further examined about the metal surface treating agent containing vanadium compounds, such as ammonium metavanadate and vanadium acetylacetonate which are used by patent documents 1, 2, it is obtained from this metal surface treating agent. It has become clear that the corrosion resistance and conductivity of the film have not reached the levels required recently, and need to be improved.
Further, in Patent Document 2, since hydrogen peroxide is used, there is a possibility of causing a fire or an explosion due to heat or the like, and there is a problem in terms of safety at the time of manufacture.

  In addition, although there exists a method of making a membrane | film | coat thin as a method of improving electroconductivity, in this method, corrosion resistance will fall. Moreover, when resin etc. are mix | blended with a metal surface treating agent so that corrosion resistance is acquired, although a thin film | membrane with favorable corrosion resistance will be obtained, electroconductivity will fall. Thus, the electrical conductivity and the corrosion resistance are often in a trade-off relationship, and it has been difficult to achieve both at a high level.

  On the other hand, when the present inventor further examined a metal surface treatment agent containing a silane compound as disclosed in Patent Document 3, various properties of the film obtained from the metal surface treatment agent (for example, corrosion resistance) , Conductivity, heat resistance, etc.) have not always reached a level that is practically satisfactory.

  Thus, the conventional known metal surface treatment agent can form a film excellent in conductivity, corrosion resistance, topcoat adhesion, heat resistance, and storage stability that can be used as a substitute for the chromate film. However, there has been a strong demand for the development of a metal surface treatment agent that can satisfy these requirements comprehensively.

  In view of the above circumstances, the present invention is a metal surface treatment agent that is excellent in topcoat adhesion, heat resistance, and storage stability, and in particular, can obtain a film that can achieve both high conductivity and corrosion resistance. The purpose is to provide.

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 inventor has obtained a hydrolyzate obtained by using a predetermined amount of vanadium alkoxide (A) represented by a predetermined structural formula and a predetermined alkoxy group-containing metal compound (B), and By using a metal surface treatment agent containing a condensate / or its condensate, it has been clarified that a film excellent in both corrosion resistance and conductivity can be obtained, and the present invention has been completed.
That is, the present invention provides the following (1) to (8).

(1) A hydrolyzate obtained by using at least the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) and / or a condensate thereof, wherein the vanadium alkoxide (A) has the general formula VO (OR) ₃ (R each independently represents an alkyl group), and the alkoxy group-containing metal compound (B) is at least one selected from the group consisting of Si, Ti, Zr, Al, Mg, Sn, and In. A metal surface treating agent comprising a seed metal element and an alkoxy group, wherein the molar ratio (A / B) of the vanadium alkoxide (A) to the compound (B) is 0.005 to 5.

  (2) The metal surface treating agent according to (1) above, wherein the hydrolyzate and / or the condensate thereof has a weight average molecular weight of 100 to 5,000.

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

  (4) A surface treatment 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. Metal 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 the above (4) or (5), wherein the mass of the film obtained by heating and 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.

  According to the present invention, there is provided a metal surface treatment agent capable of obtaining a film that is excellent in adhesion with top coat, heat resistance and storage stability, and in particular, can achieve both high conductivity and corrosion resistance. Can do.

<Metal surface treatment agent>
The metal surface treating agent of the present invention contains a hydrolyzate obtained by using at least the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) and / or a condensate thereof, and the vanadium alkoxide (A) The general formula VO (OR) ₃ (R each independently represents an alkyl group), and the alkoxy group-containing metal compound (B) is composed of Si, Ti, Zr, Al, Mg, Sn, and In. Metal surface containing at least one metal element selected from the group and an alkoxy group, wherein the molar ratio (A / B) of the vanadium alkoxide (A) to the compound (B) is 0.005 to 5 It is a processing agent.
Hereinafter, the components of the metal surface treatment agent of the present invention will be described.

[Vanadium alkoxide (A)]
The vanadium alkoxide (A) is a compound represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group).
The vanadium alkoxide (A) is 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 by hydrolysis in the presence of water, or all of the alkoxy groups are hydroxyl groups. And the like are produced. When a film is obtained from a metal surface treatment agent containing such a compound, amorphous vanadium oxide can be formed.
By including amorphous vanadium oxide obtained from the vanadium alkoxide (A) in the film, it is considered that the corrosion resistance and conductivity that are usually 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 (A) has an alkoxy group and has a hydroxy group by hydrolysis. Both the alkoxy group and the hydroxy group are electron donating groups. Therefore, the vanadium alkoxide (A) is in a state where tetravalent vanadium is easily formed, and it is considered that the hopping conduction between V ^{4+ and} V ⁵⁺ is promoted.

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 (A) include vanadium oxytriisopropoxide, vanadium oxytributoxide, vanadium oxytriethoxide, vanadium oxytriisobutoxide, etc. Among them, the corrosion resistance and conductivity of the resulting film Therefore, vanadium oxytriisopropoxide and vanadium oxytributoxide are preferable.

  Although the amount (content) of the vanadium alkoxide (A) in the metal surface treatment agent of the present invention is not particularly limited, it is based on the total amount of the treatment agent from the viewpoint of the corrosion resistance of the coating and the storage stability of the treatment agent. 0.05 to 20% by mass, and more preferably 0.1 to 10% by mass.

[Alkoxy group-containing metal compound (B)]
The alkoxy group-containing metal compound (B) is a compound containing at least one metal element selected from the group consisting of Si, Ti, Zr, Al, Mg, Sn, and In and an alkoxy group.

In the metal surface treatment agent of the present invention, the presence of the alkoxy group-containing metal compound (B) together with the vanadium alkoxide (A) can further improve the corrosion resistance, coating adhesion, conductivity, etc. of the resulting film. it can.
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.

  In the obtained film, V (vanadium element) derived from the vanadium alkoxide (A) and the metal element M derived from the alkoxy group-containing metal compound (B) are subjected to a sol-gel reaction (hydrolysis condensation reaction). For example, since a network through oxygen such as VOM 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. .

Among the alkoxy group-containing metal compounds (B), it is preferable to contain a metal element selected from Si, Ti and Zr, and Si is particularly preferable from the viewpoint of excellent corrosion resistance and conductivity of the film.
Although it does not restrict | limit especially as an alkoxy group contained, A methoxy group, an ethoxy group, a propoxy group, an isopropoxy group etc. are mentioned.

The alkoxy group-containing metal compound (B) can also be expressed as the following formula (X).
R ¹ _n M (OR ² ) _mn formula (X)
R ¹ represents an organic group. Although it does not restrict | limit especially as an organic group, For example, 1) Hydrocarbon groups (aliphatic hydrocarbon group), such as an alkyl group (for example, a methyl group, an ethyl group, a propyl group), an aryl group (for example, a phenyl group), and a vinyl group 2) Hydrocarbon groups having substituents such as mercaptopropyl group, methacryloyloxypropyl group, γ-glycidoxypropyl group, γ-ureidopropyl group, N, N-dimethylamino group, etc. (Substituted hydrocarbon group) 3) Oxygen-binding ligands such as acetylacetonate group, triethanolaminate group, and ethylacetoacetate group can be mentioned.
M represents a metal atom selected from the group consisting of Si, Ti, Zr, Al, Mg, Sn and In.
R ² represents an alkyl group. Especially, C1-C6 is preferable and C1-C3 is more preferable.
When R ¹ are a plurality, each R ¹ may be different from one another identical, if OR ² there are a plurality, each OR ² may be different even identical to each other.
m is the valence of the metal atom M, and specifically represents an integer of 2 to 4. n is an integer of 0 to 2 when m is 4, an integer of 0 to 1 when m is 3, and 0 when m is 2.

  Among the alkoxy group-containing metal compounds (B) containing Si, an alkoxy group-containing compound (B) having a hydrophobic functional group is preferable because the resulting film is hydrophobic and has better corrosion resistance. Particularly preferred are the containing alkoxysilanes and mercapto group-containing alkoxysilanes.

Specific examples of the alkoxy group-containing metal compound (B) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltriethoxysilane, and N-2- (aminoethyl). ) -3-Aminopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltri Methoxysilane, titanium diisopropoxybis (acetylacetonate), titanium diisopropoxybis (triethanolaminate), zirconium tributoxymonoacetylacetonate, zirconium dibutoxybis (ethylacetate) Acetate), aluminum triisopropoxide, aluminum tri-tert-butoxide, magnesium dibutoxide, magnesium diisopropoxide, tin tetraisopropoxide, tin tetra-sec butoxide, indium triisopropoxide, indium tri-tert-butoxide, etc. Is mentioned.
Of these, vinyltrimethoxysilane, titanium diisopropoxybis (acetylacetonate), and zirconium tributoxymonoacetylacetonate are preferred because of their superior corrosion resistance and electrical conductivity.

  The amount (content) of the alkoxy group-containing metal compound (B) 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 It is preferable that it is 0.50-20 mass% with respect to.

[Hydrolyzate and / or its condensate]
The metal surface treating agent of the present invention contains a hydrolyzate and / or a condensate thereof obtained by using at least the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B). In other words, a hydrolyzate obtained by hydrolyzing and condensing a starting material (hydrolyzable compound material) containing the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) and / or a condensate thereof. contains.
The “hydrolyzate obtained by using vanadium alkoxide (A) and alkoxy group-containing metal compound (B)” means that the hydrolyzate of vanadium alkoxide (A) and the hydrolyzate of alkoxy group-containing metal compound (B). It is a concept including a decomposition product.
The “condensate of a hydrolyzate obtained using vanadium alkoxide (A) and an alkoxy group-containing metal compound (B)” includes a hydrolyzate condensate of vanadium alkoxide (A) and an alkoxy group-containing metal compound. It is a concept including a hydrolyzate condensate of (B) and a hydrolyzate condensate (cocondensate) of vanadium alkoxide (A) and an alkoxy group-containing metal compound (B).
In addition to the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B), other hydrolyzable compounds may be used in combination as raw materials within a range not impairing the effects of the present invention.

  The vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) reach a condensation reaction through a hydrolysis reaction in a solvent (such as water), for example. By the hydrolysis reaction, V—OH and M—OH (M is at least one metal element selected from the group consisting of Si, Ti, Zr, Al, Mg, Sn, and In) are generated. If the hydrolysis reaction proceeds sufficiently, the production of VOV, MOM, and VOM 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 heating and reaction time as necessary to obtain the intended weight average molecular weight.

The film obtained from the metal surface treatment agent of the present invention has a corrosion resistance compared to the film from the metal surface treatment agent containing only one of the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B). And excellent conductivity.
This is because the hopping conduction is promoted and the conductivity is improved, and the molecular weight is increased to suppress the oxygen permeability and the water vapor permeability, thereby exhibiting excellent barrier properties and improving the corrosion resistance. Moreover, the hydroxyl group which did not contribute to condensation reacts with the polar group which the top coat has, and improves the top coat adhesion.

[Molar ratio (A / B)]
In the metal surface treating agent of the present invention, the molar ratio (A / B) between the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) used is 0.005 to 5, 0.01 It is preferable that it is -1, and it is preferable that it is 0.05-0.5.
When the molar ratio (A / B) is less than 0.005, not only corrosion resistance cannot be obtained, but also the conductivity is inferior because the effect of hopping conduction by the vanadium alkoxide (A) is reduced. On the other hand, when the molar ratio (A / B) exceeds 5, the fixing rate of vanadium in the film is lowered, the corrosion resistance and the heat resistance are inferior, and the storage stability of the treatment agent is also deteriorated.

[Weight average molecular weight]
In the present invention, the hydrolyzate obtained using at least the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) and / or the condensate thereof may have a weight average molecular weight of 100 to 5,000. Preferably, it is 200-2000.
When the weight average molecular weight is within this range, the condensation of the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) is sufficient, so that the corrosion resistance of the film is more excellent. In addition, when the weight average molecular weight is within this range, the molecular weight is appropriate, and the storage stability of the treatment agent is also good.
If the weight average molecular weight is too low, condensation may be insufficient and sufficient corrosion resistance may be difficult to obtain. If the weight average molecular weight is too high, sufficient storage stability of the treatment agent may not be obtained.

[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 liquid 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, sufficient liquid stability of the treatment agent may not be obtained.

As the pH adjusting agent for adjusting the pH, conventionally known ones can be used. For example, phosphoric acid, hydrofluoric acid, nitric acid, formic acid, acetic acid, lactic acid, glycolic acid, phosphonic acid, citric acid, tartaric acid, Examples include 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 alcohol, ketone, cellosolve-based water-soluble organic solvent is added if necessary, such as improvement of 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]
To the metal surface treatment agent of the present invention, additives such as a surfactant, an antifoaming agent, and a leveling agent can be added within a range not impairing the spirit and film performance of the present invention.

<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 known plating methods such as electroplating method, hot dipping method, vapor deposition plating method, dispersion plating method, vacuum plating method, displacement plating method, chemical plating method and 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, the adhesion is better, and the conductivity is more excellent.

<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>
The vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) were mixed in advance according to the mixing ratio shown in Table 1 to be described later, and then dropped into distilled water. The mixture was stirred for 30 minutes, and the pH was adjusted with a pH adjuster to obtain a predetermined metal surface treatment agent.

The weight average molecular weight of the hydrolyzate and / or its condensate obtained by using the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) in the obtained metal surface treatment agent was determined by gel filtration chromatography (GFC). Was determined using. 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 components used for the preparation of the metal surface treatment agent, the molar ratio (A / B) of the vanadium alkoxide (A) to the alkoxy group-containing metal compound (B), the vanadium alkoxide (A) and the alkoxy. The hydrolyzate obtained using the group-containing metal compound (B) and / or the condensate weight average molecular weight and the pH of the metal surface treatment agent are shown. In Table 1, the mass% of the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) represents the amount charged (mass%) relative to the total amount of the processing agent.
In Examples 1 to 25, hydrolyzate of vanadium alkoxide (A) and its condensate, hydrolyzate of alkoxy group-containing metal compound and its condensate, and vanadium alkoxide (A) and alkoxy group-containing metal A cocondensate with the compound was contained.
Specific names of the components corresponding to the symbols shown in Table 1 are shown below.

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

・ Alkoxy group-containing metal compound (B)
B1: Vinyltrimethoxysilane B2: 3-Glycidoxypropyltrimethoxysilane B3: 3-Aminopropyltriethoxysilane B4: Titanium diisopropoxybis (acetylacetonate)
B5: Zirconium tributoxy monoacetylacetonate B6: Aluminum triisopropoxide B7: Magnesium dibutoxide B8: Tin tetraisopropoxide B9: Indium triisopropoxide

PH adjuster D1: phosphoric acid D2: monoethanolamine D3: acetic acid D4: 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) Plane portion corrosion resistance Using a test piece of an unprocessed surface-treated metal material, evaluation was performed as follows based on the area ratio of white rust generated 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

(2) 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

(3) Processed part corrosion resistance Using an unprocessed surface-treated metal material test piece, after extruding 7 mm from Erichsen, the area ratio of white rust generated 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

(4) Conductivity Using a test piece of a surface-treated metal material, a load with which the surface resistance is 10 −3 Ω or less was evaluated as follows with a four-probe surface resistance measuring device.
・ 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

(5) Adhesion of topcoat coating The test piece of the surface-treated metal material was coated with a melamine alkyd resin paint using a bar coater so that the dry film thickness was 25 μm, and baked at an oven temperature of 130 ° C. for 20 minutes. Next, a grid of 1 mm and 100 squares was applied with a cutter, and the part was further subjected to Erichsen processing by extruding 7 mm. A tape peeling test was performed on the processed part, and the number of remaining resin layers was evaluated as follows.
○: 100 △: 50 or more and 99 or less ×: Less than 50

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

(7) 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 in 40 degreeC atmosphere.
○: More than 1 month ×: Less than 1 month

Table 1 shows the evaluation results.
From the evaluation results shown in Table 1, it was found that Examples 1 to 25 were both excellent in corrosion resistance and conductivity, and also had good top coat adhesion, heat resistance, and storage stability.

Moreover, when Examples 1-6 were seen, Example 3 whose molar ratio (A / B) was 0.05 and Example 4 which is 0.5 were understood that it was excellent by corrosion resistance and electroconductivity. .
Moreover, when Examples 7-11 were seen, it turned out that the outstanding effect is acquired in the wide pH range of a processing agent.
Moreover, when Examples 12-16 were seen, it turned out that the outstanding effect is acquired in various film | membrane masses.

Moreover, when Examples 1-11 are seen, Examples 1-6 using B1 (vinyl trimethoxysilane) rather than Examples 7-11 using B2 (3-glycidoxypropyltrimethoxysilane). It has been found that is superior in corrosion resistance (after alkali degreasing) and conductivity.
Moreover, when Examples 1-6 and 12-16 are seen, Example 1 using B1 (vinyl trimethoxysilane) rather than Examples 12-16 using B3 (3-aminopropyltriethoxysilane). 6 was found to be more excellent in corrosion resistance (after alkali degreasing) and conductivity.

  Further, when Examples 17 to 25 are viewed, Example 17 using B1 (vinyltrimethoxysilane), Example 20 using B4 (titanium diisopropoxybis (acetylacetonate)), and B5 (zirconium tributoxy). It was found that Example 21 using monoacetylacetonate was superior in corrosion resistance.

On the other hand, it can be seen from the evaluation results shown in Table 1 that Comparative Example 1 containing no vanadium alkoxide (A) does not provide the barrier property and hopping conduction effect of the film, and both the corrosion resistance and conductivity are inferior. It was. Furthermore, it was inferior also in coating adhesiveness and heat resistance.
Further, Comparative Example 2 having a molar ratio (A / B) less than the lower limit value of the range (0.005 to 5) of the present invention is inferior in conductivity because not only corrosion resistance is obtained, but also the effect of hopping conduction is reduced. I understood that.
Moreover, it was found that Comparative Example 3 in which the molar ratio (A / B) exceeded the upper limit of the range (0.005 to 5) of the present invention was inferior in corrosion resistance due to a decrease in the fixing rate of vanadium in the film. .
Moreover, it turned out that the comparative example 4 which does not contain an alkoxy group containing metal compound (B) is inferior to corrosion resistance and coating adhesion.
Comparative Examples 5 to 7 in which the vanadium alkoxide (A) is A3 (ammonium metavanadate), A4 (vanadium acetylacetonate, or A5 (vanadium diisopropoxybis (acetylacetonate)) are used as barriers for the film. Thus, it was found that the corrosion resistance and conductivity were inferior.

Claims (8)

A hydrolyzate obtained by using at least the vanadium alkoxide (A) and the alkoxy group-containing metal compound (B) and / or a condensate thereof,
The vanadium alkoxide (A) is represented by the general formula VO (OR) ₃ (R each independently represents an alkyl group),
The alkoxy group-containing metal compound (B) contains at least one metal element selected from the group consisting of Si, Ti, Zr, Al, Mg, Sn and In and an alkoxy group,
The metal surface treating agent whose molar ratio (A / B) of the said vanadium alkoxide (A) and the said compound (B) is 0.005-5.   The metal surface treating agent according to claim 1, wherein the hydrolyzate and / or the condensate thereof has a weight average molecular weight of 100 to 5,000.   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.