JP4907315B2 - Surface-treated metal material - Google Patents

Description

  The present invention relates to a surface-treated metal material, and in particular, a metal material subjected to a chromate-free surface treatment excellent in corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black residue resistance during processing, and stain resistance. About.

  Generally, it has excellent adhesion to the metal material surface, and as a technology to give corrosion resistance and fingerprint resistance to the metal material surface, it contains chromic acid, dichromic acid or their salts as the main component on the metal material surface. In recent years, the chromate treatment film contains a large amount of harmful hexavalent chromium, and it is a non-chromium type that can be used as an alternative to the chromate film in consideration of the environment. Surface treatment technology is being developed. Examples of such non-chromium-based surface treatment techniques include a method of performing a treatment using an inorganic component, a method of performing a phosphate treatment, a method of performing a treatment with a silane coupling agent alone, and a method of performing an organic resin film treatment. , Etc. are known and are in practical use.

  As a technique mainly using an inorganic component, for example, Patent Document 1 discloses a metal surface treatment containing a vanadium compound and a metal compound containing at least one metal selected from zirconium, titanium, molybdenum, tungsten, manganese, and cerium. Agents are mentioned.

  On the other hand, as a technique mainly using a silane coupling agent, for example, Patent Document 2 teaches treatment of a metal plate with an aqueous solution containing a low concentration of an organofunctional silane and a crosslinking agent in order to obtain a temporary anticorrosive effect. is doing. Further, this document discloses a method for forming a dense siloxane film by crosslinking an organofunctional silane with a crosslinking agent.

  Further, for example, Patent Document 3 discloses a specific resin compound (A) and a cationic urethane resin (B) having at least one cationic functional group selected from a first to third amino group and a quaternary ammonium base. And at least one silane coupling agent (C) having a specific reactive functional group and a specific acid compound (E), and a cationic urethane resin (B) and a silane coupling agent (C ), A non-chromium surface-treated steel sheet excellent in corrosion resistance, excellent in fingerprint resistance, blackening resistance and paint adhesion, and a method for producing the same are disclosed. Yes.

  Furthermore, for example, Patent Documents 4 to 5 disclose a method for imparting contamination resistance by adding a photocatalyst (L) into a surface treatment agent.

JP 2002-30460 A US Pat. No. 5,292,549 JP 2003-105562 A Japanese Patent Laid-Open No. 10-314599 JP 2001-64539 A

  However, these technologies do not satisfy all of the corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black scum resistance during processing, and contamination resistance. ing.

  As described above, the surface treatment agent that can be used as a substitute for the chromate film has not been obtained by any of these methods, and there is a strong demand for the development of a surface treatment agent and a treatment method that can satisfy these conditions comprehensively. -ing

  Therefore, the present invention solves the above-mentioned problems of the prior art, and can satisfy all of corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black residue resistance during processing and stain resistance. It aims at providing the metal material which gave chromate free surface treatment.

  As a result of intensive studies to solve these problems, the present inventors have obtained an intramolecular structure obtained by blending two kinds of specific silane coupling agents at a specific solid content mass ratio on the metal material surface. In which two or more specific functional groups, one or more specific hydrophilic functional groups are contained, an organosilicon compound (W), a fluoro compound (X), phosphoric acid (Y), and a vanadium compound (Z) And a water-based metal surface treatment agent comprising photocatalyst (L) is applied and dried to form a composite film containing each component, thereby providing corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, processing The present inventors have found that a chromate-free surface-treated metal material that can satisfy all of the black residue resistance and contamination resistance at the time can be obtained, and the present invention has been completed.

That is, the present invention provides a solid content of a silane coupling agent (A) containing one amino group in the molecule and a silane coupling agent (B) containing one glycidyl group in the molecule on the surface of the metal material. Formula-SiR ¹ R ² R ³ (in the formula, R ¹ , R ² and R are obtained by blending at a mass ratio [(A) / (B)] of 0.5 to 1.7. ³ independently represents an alkoxy group or a hydroxyl group, at least one represents an alkoxy group, and two or more functional groups (a) and a hydroxyl group (which can be contained in the functional group (a)) And at least one hydrophilic functional group (b) selected from amino groups, an organosilicon compound (W) having an average molecular weight of 1000 to 10,000, and titanium hydrogen fluoride At least selected from acid or zirconium hydrofluoric acid A composite containing each component by applying and drying an aqueous metal surface treatment agent comprising one kind of fluoro compound (X), phosphoric acid (Y), vanadium compound (Z), and photocatalyst (L). A film is formed, and in each component of the composite film, the solid content mass ratio [(X) / (W)] of the organosilicon compound (W) and the fluoro compound (X) is 0.02 to 0.07. Yes, the solid content mass ratio [(Y) / (W)] of the organosilicon compound (W) and phosphoric acid (Y) is 0.03 to 0.12, and the organosilicon compound (W) and the vanadium compound (Z ) Solid content mass ratio [(Z) / (W)] is 0.05 to 0.17, and the solid content mass ratio of fluoro compound (X) and vanadium compound (Z) [(Z) / ( X)] is 1.3 to 6.0, and the total solid content mass ratio of the photocatalyst (L) [(L) / (W) + (X) + (Y) + (Z) + (L)) to provide a surface-treated metal material which is a 0.02 to 0.5.

  The water-based metal surface treatment agent comprises at least one cobalt compound (C) selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate in the coating of the organosilicon compound (W) and the cobalt compound (C). The solid content mass ratio [(C) / (W)] is preferably contained at a ratio of 0.01 to 0.1.

The surface-treated metal material is coated with the aqueous metal surface-treating agent on the surface of the metal material, and dried at a temperature higher than 50 ° C. and lower than 250 ° C., and the film weight after drying is 0.05-2. It is preferably 0 g / m ² .

  The metal material is preferably a galvanized steel sheet.

  The surface-treated metal material of the present invention can satisfy all of corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black residue resistance during processing, and contamination resistance.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The metal material applicable in the present invention is not particularly limited, and examples thereof include iron, iron-base alloy, aluminum, aluminum-base alloy, copper, copper-base alloy, and the like, and optionally plated on the metal material. A plated metal material can also be used. Among them, the most suitable for the application of the present invention is a galvanized steel sheet. 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. Galvanized steel sheet such as plated steel sheet, zinc-aluminum-magnesium plated steel sheet, zinc-aluminum-magnesium-silicon plated steel sheet, and cobalt, molybdenum, tungsten, nickel as a small amount of different metal elements or impurities in these plated layers Examples include those containing titanium, chromium, aluminum, manganese, iron, magnesium, lead, bismuth, antimony, tin, copper, cadmium, arsenic and the like, and those in which inorganic substances such as silica, alumina, and titania are dispersed. Furthermore, multi-layer plating in combination with the above plating and other types of plating such as iron plating, iron-phosphorus plating, nickel plating, cobalt plating and the like is also applicable. The plating method is not particularly limited, and any known method such as an electroplating method, a hot dipping method, a vapor deposition plating method, a dispersion plating method, and a vacuum plating method may be used.

  The organosilicon compound (W), which is an essential component of the aqueous metal surface treatment agent of the chromate-free surface treatment metal material of the present invention, includes a silane coupling agent (A) containing one amino group in the molecule, and It is obtained by blending a silane coupling agent (B) containing one glycidyl group at a solid content mass ratio [(A) / (B)] of 0.5 to 1.7. As a compounding ratio of the silane coupling agent (A) and the silane coupling agent (B), it is necessary that the solid content mass ratio [(A) / (B)] is 0.5 to 1.7, and 0 0.7 to 1.7 is preferable, and 0.9 to 1.1 is most preferable. If the solid content mass ratio [(A) / (B)] is less than 0.5, fingerprint resistance, bath stability, and black residue resistance are remarkably lowered, which is not preferable. On the other hand, if it exceeds 1.7, the water resistance is remarkably lowered.

  Further, the silane coupling agent (A) containing one amino group in the molecule in the present invention is not particularly limited, but 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, etc. Examples of the silane coupling agent (B) containing one glycidyl group in the molecule include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like. Can do.

  Moreover, the manufacturing method of the organosilicon compound (W) of the present invention is not particularly limited. For example, water adjusted to about pH 4 is mixed with a silane coupling agent (A) and a silane coupling agent (B). Are sequentially added and stirred for a predetermined time.

Formula -SiR ¹ R ² R ³ in the organosilicon compound (W) which is an essential component of the present invention (wherein R ¹ , R ² and R ³ independently represent an alkoxy group or a hydroxyl group, and at least one of The number of functional groups (a) represented by (representing an alkoxy group) needs to be 2 or more. When the number of functional groups (a) is one, the adhesion to the metal material surface and the film-forming property are lowered, so that the black residue resistance is lowered. The number of carbon atoms of the alkoxy group in the definition of R ¹ , R ² and R ³ of the functional group (a) is not particularly limited, but is preferably 1 to 6, more preferably 1 to 4, more preferably 1 or 2. Most preferably. According to the inventors' inference, the number of bonds per unit area of OM (metal) bonds formed between the alkoxy group and the base metal plate is shorter when the carbon chain of the alkoxy group is shorter. This is because the contact force between the film and the metal plate increases. The existence ratio of at least one hydrophilic functional group (b) selected from a hydroxyl group and an amino group may be one or more in one molecule. The average molecular weight of the organosilicon compound (W) needs to be 1000 to 10000, and preferably 1300 to 6000. The molecular weight here is not particularly limited, but either direct measurement by TOF-MS method or conversion measurement by chromatography method may be used. When the average molecular weight is less than 1000, the water resistance of the formed film is remarkably lowered. On the other hand, if the average molecular weight is greater than 10,000, it is difficult to stably dissolve or disperse the organosilicon compound.

  Moreover, regarding the compounding quantity of fluoro compound (X) which is an essential component of this invention, solid content mass ratio [(X) / (W)] of organosilicon compound (W) and fluoro compound (X) is 0.00. It is necessary to be 02 to 0.07, 0.03 to 0.06 is preferable, and 0.04 to 0.05 is most preferable. When the solid content mass ratio [(X) / (W)] of the organosilicon compound (W) and the fluoro compound (X) is less than 0.02, the effect of adding the fluoro compound (improvement of corrosion resistance) is not manifested. Absent. On the contrary, if it is larger than 0.07, the conductivity is lowered, which is not preferable.

  Moreover, regarding the compounding quantity of phosphoric acid (Y) which is an essential component of this invention, solid content mass ratio [(Y) / (W)] of organosilicon compound (W) and phosphoric acid (Y) is 0.03. It is necessary to be -0.12, preferably 0.05-0.12, and most preferably 0.09-0.1. If the solid content mass ratio [(Y) / (W)] of the organosilicon compound (W) and phosphoric acid (Y) is less than 0.03, the addition effect (improvement of corrosion resistance) of phosphoric acid is not preferable. . On the other hand, if it exceeds 0.12, the film becomes extremely water-soluble, which is not preferable.

  Moreover, regarding the compounding quantity of the vanadium compound (Z) which is an essential component of this invention, solid content mass ratio [(Z) / (W)] of an organosilicon compound (W) and a vanadium compound is 0.05-0. 17 and preferably 0.07 to 0.15, more preferably 0.09 to 0.14, and most preferably 0.11 to 0.13. When the solid content mass ratio [(Z) / (W)] of the organosilicon compound (W) and the vanadium compound (Z) is less than 0.05, the effect of adding the vanadium compound (improvement in corrosion resistance) does not appear, which is not preferable. . On the other hand, if it exceeds 0.17, the stability is extremely lowered, which is not preferable.

Further, the vanadium compound (Z) in the present invention is not particularly limited, but vanadium pentoxide V ₂ O ₅ , metavanadate HVO ₃ , ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride VOCl ₃ , three Vanadium oxide V ₂ O ₃ , vanadium dioxide VO ₂ , vanadium oxysulfate VOSO ₄ , vanadium oxyacetylacetonate VO (OC (═CH ₂ ) CH ₂ COCH ₃ )) ₂ , vanadium acetylacetonate V (OC (═CH ₂ ) CH ₂ COCH ₃ )) ₃ , vanadium trichloride VCl ₃ , phosphovanadomolybdic acid and the like. In addition, the pentavalent vanadium compound is an organic compound having at least one functional group selected from the group consisting of a hydroxyl group, a carbonyl group, a carboxyl group, a primary to tertiary amino group, an amide group, a phosphoric acid group, and a phosphonic acid group. Those reduced to tetravalent to divalent can also be used.

  Moreover, regarding the compounding quantity of fluoro compound (X) and vanadium compound (Z) which are essential components of this invention, solid content mass ratio [(Z) / (X) of fluoro compound (X) and vanadium compound (Z) ] Needs to be 1.3 to 6.0, preferably 1.3 to 3.5, more preferably 2.5 to 3.3, and 2.8 to 3.0. Most preferably it is. It is not preferable that the solid mass ratio [(Z) / (X)] of the fluoro compound (X) and the vanadium compound (Z) is less than 1.3 because the effect of adding the vanadium compound (Z) is not exhibited. On the other hand, if it exceeds 6.0, bath stability and black residue resistance are lowered, which is not preferable.

  On the other hand, the photocatalyst (L) in the present invention is a particle that develops photocatalytic performance when irradiated with light having a wavelength greater than the band gap. Titanium oxide, zinc oxide, tungsten oxide, iron oxide, titanium One or more known metal compound semiconductors such as strontium acid can be used in combination. Among these, titanium oxide having high photocatalytic activity, chemically stable and harmless, particularly this anatase type is preferable. Furthermore, in order to stabilize the photocatalyst (L) in the treatment liquid, improve the photocatalytic effect, etc., in some cases, Pt, Au as a second component may be present inside or at least one of the surfaces of the photocatalyst particles. , Ag, Cu, Co, Ni, Pd, Rh, Ru, V, Fe, and at least one selected from the group consisting of two or more metals or metal compounds, a pH buffer, etc. One type or two or more types may be contained.

  Moreover, regarding the compounding quantity of the photocatalyst (L) which is an essential component of this invention, mass ratio [(L) / ((W) + (X) + (Y) + (Z) with respect to the total solid of a photocatalyst (L). ) + (L))] needs to be 0.02 to 0.5, preferably 0.03 to 0.45, and most preferably 0.05 to 0.3. When the mass ratio [(L) / ((W) + (X) + (Y) + (Z) + (L))] to the total solid content of the photocatalyst (L) is less than 0.02, the photocatalyst (L) Since the additive effect (contamination resistance) does not appear, it is not preferable. On the contrary, if it is larger than 0.5, the film formability of the film is lowered, which is not preferable.

  The cobalt compound (C) as an additive component of the present invention is preferably at least one cobalt compound selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate. The blending ratio is preferably such that the solid content mass ratio [(C) / (W)] of the organosilicon compound (W) and the cobalt compound (C) is 0.01 to 0.1. It is more preferably 02 to 0.07, and most preferably 0.03 to 0.05. When the solid content mass ratio [(C) / (W)] of the organosilicon compound (W) and the cobalt compound (C) is less than 0.01, the addition effect of the cobalt compound (C), that is, the initial corrosion of zinc This is not preferable because the product (basic zinc chloride) is stabilized and the effect of exhibiting a corrosion inhibiting effect as a corrosion barrier is not exhibited. Conversely, if it is larger than 0.1, the corrosion resistance is lowered, which is not preferable.

The surface-treated metal material of the present invention is coated with the aqueous metal surface treatment agent and dried at a temperature higher than 50 ° C. and lower than 250 ° C., and the film weight after drying is 0.05 to 2.0 g / m ^2. It is preferable that The drying temperature is preferably higher than 50 ° C. and lower than 250 ° C., more preferably 70 ° C. to 150 ° C., and most preferably 100 ° C. to 140 ° C. An ultimate temperature of 50 ° C. or lower is not preferable because the solvent for the aqueous metal surface treatment agent does not completely evaporate. Conversely, when the temperature is 250 ° C. or higher, a part of the organic chain of the film formed with the aqueous metal surface treatment agent is decomposed, which is not preferable. For the coating weight is preferably from 0.05 to 2.0 g / ^{m 2,} more preferably from 0.2 to 1.0 g / ^{m 2,} is 0.3-0.6 g / ^{m 2} Most preferred. When the film weight is less than 0.05 g / m ² , the surface of the metal material cannot be coated, and therefore the corrosion resistance is remarkably lowered. Conversely, if it is larger than 2.0 g / m ² , the black residue resistance at the time of processing is lowered, which is not preferable.

  The water-based metal surface treatment agent used in the present invention includes a leveling agent, a water-soluble solvent, a metal stabilizer, an etching inhibitor, a pH adjuster, and the like for improving the coating properties within a range that does not impair the effects of the present invention. It is possible to use. Examples of the leveling agent include nonionic or cationic surfactants such as polyethylene oxide or polypropylene oxide adducts and acetylene glycol compounds. Examples of the water-soluble solvent include alcohols such as ethanol, isopropyl alcohol, t-butyl alcohol and propylene glycol, cellosolves such as ethylene glycol monobutyl ether and ethylene glycol monoethyl ether, esters such as ethyl acetate and butyl acetate, Examples include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of the metal stabilizer include chelate compounds such as EDTA and DTPA, and examples of the etching inhibitor include amine compounds such as ethylenediamine, triethylenepentamine, guanidine and pyrimidine. In particular, those having two or more amino groups in one molecule are more preferable because they are effective as metal stabilizers. Examples of the pH adjuster include organic acids such as acetic acid and lactic acid, inorganic acids such as hydrofluoric acid, ammonium salts and amines.

  Furthermore, if the use which requires severe shaping | molding, such as roll homing processing of the metal material which apply | coats the processing agent of this invention is also considered, the effect of this invention will not be impaired to said aqueous metal surface treatment agent. In the range, a lubricant for improving the moldability may be added. Examples of the lubricant include organic lubricants such as polyethylene wax.

  The surface-treated metal material of the present invention can satisfy all of corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black residue resistance during processing, and contamination resistance. The reason is presumed as follows, but the present invention is not limited to such presumption. The film formed using the aqueous metal surface treatment agent used in the present invention is mainly composed of an organosilicon compound. First, the corrosion resistance is such that when one part of the organosilicon compound is concentrated by drying or the like, the organosilicon compound reacts with each other to form a continuous film, and one part of the organosilicon compound hydrolyzes. It is presumed that the generated —Si—OH group forms a Si—O—M bond (M: metal element on the surface of the object to be coated) and exerts a remarkable barrier effect. In addition, since a dense film can be formed, the film can be thinned and the conductivity is improved.

  On the other hand, the film using the water-based metal surface treatment agent of the present invention is formed on the basis of silicon, and because of its structure, the arrangement of silicon-organic chains is regular and the organic chains are relatively short, The silicon-containing part and the organic part, that is, the inorganic substance and the organic substance are regularly and densely arranged in a very small area in the film. Therefore, it is presumed that it becomes possible to form a new film having both heat resistance, conductivity, black residue at the time of workability, and anti-fingerprint property and paintability normally possessed by organic films. . The analysis confirmed that about 80% of silicon formed siloxane bonds in the silicon-containing part of the film.

  For the purpose of imparting corrosion resistance to such a base film, a fluoro compound that forms a dense film by raising the pH in the vicinity of the surface of the metal to be treated generated by the etching reaction, phosphoric acid as an eluting inhibitor, and corrosion resistance by redox reaction. By adding the vanadium compound to be imparted, it is presumed that excellent corrosion resistance is exhibited in addition to heat resistance, fingerprint resistance, conductivity, paintability, black scum resistance during processing and stain resistance.

  In addition to the above, by adding a photocatalyst to the aqueous metal surface treatment agent of the present invention, good contamination resistance is expressed as described above because the coating using the aqueous metal surface treatment agent of the present invention is based on silicon. As for the structure, it is considered that the photocatalytic degradation reaction of the organic chain hardly occurs because the arrangement of the silicon-organic chain is regular and the organic chain is relatively short. For this reason, it is presumed that the photocatalyst does not give deterioration or alteration to the film, exists stably while maintaining the various functions of the film, and maintains the resolution of external contaminants due to the photocatalytic reaction.

  EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples of the present invention, but the present invention is not limited thereto. Preparation of the test plate, examples and comparative examples, and a method of applying the surface treatment agent for metal material will be described below.

(Preparation of test plate)
(1) Test material As a metal material, the commercially available material shown below was used.
・ Electrogalvanized steel sheet (EG)
: Plate thickness = 0.8 mm, basis weight = 20/20 (g / m ² )
・ Hot galvanized steel sheet (GI)
: Plate thickness = 0.8 mm, basis weight = 90/90 (g / m ² )
・ Electro zinc-12% nickel plating (ZL)
: Plate thickness = 0.8 mm, basis weight = 20/20 (g / m ² )
-Hot-dip zinc-11% aluminum-3% magnesium-0.2% silicon plating (SD)
: Plate thickness = 0.8 mm, basis weight = 60/60 (g / m ² )
(2) Degreasing treatment The above test material is spray-treated for 2 minutes under the conditions of a concentration of 20 g / L and a temperature of 60 ° C. using a silicate alkaline degreasing agent Fine Cleaner 4336 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.). The test plate was washed with pure water for 30 seconds and then dried.
(3) Preparation of surface treatment agent After adding a silane coupling agent (A) and a silane coupling agent (B) and kneading to prepare an organosilicon compound (W), a fluoro compound (X), phosphoric acid ( Y), a vanadium compound (Z), and a lubricant (J) were added in this order, and the surface treatment agent was prepared by sufficiently stirring at room temperature.
(4) Preparation of surface-treated metal material (application method of surface treatment agent)
A surface-treating agent was applied to the test plate with a roll coater, baked while changing the ultimate plate temperature, and air-cooled to prepare a surface-treated metal material.

  Table 1 shows silane coupling agents used in Examples and Comparative Examples, Table 2 shows vanadium compounds, and Tables 3 to 5 show formulation examples, film amounts, and drying temperatures. Furthermore, the commercially available anatase-type titanium oxide (particle size distribution of 5 to 200 nm) was used as the photocatalyst used in Examples and Comparative Examples shown in Tables 3 to 5.

〔Evaluation test〕
1. SST flat surface portion test A salt spray test according to JIS-Z-2371 was performed for 120 hours, and the corrosion resistance of the flat surface portion of the surface-treated metal material was evaluated by observing the occurrence of white rust.
<Evaluation criteria>
◎ = Rust generation is less than 3% of the total area ○ = Rust generation is 3% or more and less than 10% of the total area Δ = Rust generation is 10% or more and less than 30% of the total area × = Rust generation is 30% or more of the total area

2. SST processed part test After performing Erichsen test (7 mm extrusion), a salt spray test according to JIS Z 2371 was performed for 72 hours, and the corrosion resistance of the processed part of the surface-treated metal material was evaluated by observing the occurrence of white rust.
<Evaluation criteria>
◎ = Rust generation is less than 10% of the total area ○ = Rust generation is 10% or more and less than 20% of the total area Δ = Rust generation is 20% or more and less than 30% of the total area × = Rust generation is 30% or more of the total area

3. Heat resistance test After heating for 2 hours at 200 ° C. in an oven, a salt spray test according to JIS-Z-2371 was conducted for 48 hours, and the heat resistance of the surface-treated metal material was evaluated by observing the occurrence of white rust. .
<Evaluation criteria>
◎ = Rust generation is less than 3% of the total area ○ = Rust generation is 3% or more and less than 10% of the total area Δ = Rust generation is 10% or more and less than 30% of the total area × = Rust generation is 30% or more of the total area

4). Finger Stretch Resistance Test Fingerprint resistance of the surface-treated metal material was evaluated by measuring L value increase / decrease (ΔL) before and after application of petrolatum with a color difference meter.
<Evaluation criteria>
◎ = ΔL is less than 0.5 ○ = ΔL is 0.5 or more and less than 1.0 Δ = ΔL is 1.0 or more and less than 2.0 × = ΔL is 2.0 or more

5. Conductivity test The conductivity of the surface-treated metal material was evaluated by measuring the interlayer resistance with an interlayer resistance measuring machine.
<Evaluation criteria>
◎ = Interlayer resistance is less than 1.0Ω ○ = Interlayer resistance is 1.0Ω or more and less than 2.0Ω Δ = Interlayer resistance is 2.0Ω or more and less than 3.0Ω × = Interlayer resistance is less than 3.0Ω

6). Paintability test Melamine alkyd paint was applied by bar coating so that the film thickness after baking and drying was 25 μm, baked at 120 ° C. for 20 minutes, then cut into 1 mm grids, and the adhesion ratio was evaluated By performing (remaining number / number of cuts: 100), the paintability of the surface-treated metal material was evaluated.
<Evaluation criteria>
◎ = 100%
○ = 95% or more Δ = 90% or more and less than 95% × = less than 90%

7). Black residue test The degree of occurrence of black residue when processed at a drawing ratio of 2.0 in a high-speed deep drawing test was evaluated by increasing or decreasing the L value before and after the test.
<Evaluation criteria>
◎ = ΔL is less than 0.5 ○ = ΔL is 0.5 or more and less than 1.0 Δ = ΔL is 1.0 or more and less than 2.0 × = ΔL is 2.0 or more

8). Contamination resistance test 1 mg / cm ^{2 of} salad oil was attached to the test piece, and the oil degradation rate was determined from the change in weight after irradiating with a black light having a wavelength of 365 nm and an ultraviolet intensity of 3 mW / cm ² for 24 hours. Contamination resistance was evaluated.
<Evaluation criteria>
○ = Oil decomposition rate is 40% or more × = Oil decomposition rate is less than 40%

  Test results are shown in Tables 6-17. Examples 1 to 68 exhibit corrosion resistance equivalent to that of chromate and satisfy all of good corrosion resistance, heat resistance, fingerprint resistance, conductivity, paintability, black residue resistance during processing, and contamination resistance. Recognize.

  As mentioned above, although preferred embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

Claims (4)

On the metal surface,
A functional group represented by the formula —SiR ¹ R ² R ³ (wherein R ¹ , R ² and R ³ independently represent an alkoxy group or a hydroxyl group, and at least one represents an alkoxy group) in the molecule. (A) having two or more and at least one hydrophilic functional group (b) selected from a hydroxyl group (separate from those which can be included in the functional group (a)) and an amino group An organosilicon compound (W) having an average molecular weight of 1000 to 10,000;
At least one fluoro compound (X) selected from titanium hydrofluoric acid or zirconium hydrofluoric acid;
Phosphoric acid (Y),
A vanadium compound (Z);
A photocatalyst (L);
Having a composite film containing
The organosilicon compound (W) comprises a silane coupling agent (A) containing one amino group in the molecule and a silane coupling agent (B) containing one glycidyl group in the molecule. The ratio [(A) / (B)] is obtained by blending at a ratio of 0.5 to 1.7,
The ratio of each component in the said composite film satisfy | fills the conditions of following (1)-(5), The surface treatment metal material characterized by the above-mentioned.
(1) When the mass ratio of the solid content of the organosilicon compound (W) and the fluoro compound (X) is [(X) / (W)], 0.02 ≦ [(X) / (W)] ≦ 0.07
(2) When the solid content mass ratio between the organosilicon compound (W) and the phosphoric acid (Y) is [(Y) / (W)], 0.03 ≦ [(Y) / (W)] ≦ 0.12
(3) When the solid content mass ratio between the organosilicon compound (W) and the vanadium compound (Z) is [(Z) / (W)], 0.05 ≦ [(Z) / (W)] ≦ 0.17
(4) When the solid content mass ratio between the fluoro compound (X) and the vanadium compound (Z) is [(Z) / (X)], 1.3 ≦ [(Z) / (X)] ≦ 6.0
(5) When the total solid content mass ratio of the photocatalyst (L) is [(L) / ((W) + (X) + (Y) + (Z) + (L)]), 0.02 ≦ [ (L) / ((W) + (X) + (Y) + (Z) + (L)] ≦ 0.5   In the coating, at least one cobalt compound (C) selected from the group consisting of cobalt sulfate, cobalt nitrate, and cobalt carbonate is added to the solid content mass ratio of the organosilicon compound (W) and the cobalt compound (C) [(C ) / (W)] is further contained at a ratio of 0.01 to 0.1, the surface-treated metal material according to claim 1. The aqueous metal surface treatment agent according to claim 1 or 2 is applied to the surface of the metal material and dried at a temperature higher than 50 ° C and lower than 250 ° C. A surface-treated metal material, characterized in that the surface-treated metal material is 05 to 2.0 g / m ² .   The surface-treated metal material according to claim 1, 2, or 3, wherein the metal material is a zinc-based plated steel sheet.