JP5570452B2 - Surface treatment composition - Google Patents

Description

  The present invention relates to a surface treatment composition capable of obtaining a film excellent in processability, corrosion resistance, resistance to condensation whitening, and the like, and a surface-treated metal plate obtained using the surface treatment composition.

  Conventional surface treatment methods using chromate have the problem of scattering of chromate fume in the treatment process, the wastewater treatment equipment requires a large amount of cost, and the problem of chromic acid elution from the chemical conversion coating and so on. Hexavalent chromium compounds are extremely harmful substances because many public institutions, including IARC (International Agency for Research on Cancer Review), have designated them as carcinogenic substances for the human body. Therefore, there has been a strong demand for a surface-treated steel sheet that does not contain harmful chromium and has a one-layer coating film that has both workability and corrosion resistance.

  As a composition that does not contain chromium and forms a film having both workability and corrosion resistance, for example, Patent Document 1 discloses a water-soluble resin and / or a water-dispersible resin, a lubricant function-imparting agent, silica particles, and a vanadium compound. The composition which can form the membrane | film | coat formed by containing is disclosed. Patent Document 2 discloses at least one selected from silica particles, silane coupling agents, vanadic acid compounds, metal hydrofluoric acid and metal hydrofluoric acid salts with respect to water-soluble or water-dispersible polyurethane resins. A metal surface treatment composition containing the above fluorinated compound is disclosed. In the blend compositions described in Patent Documents 1 and 2, a film excellent in workability and corrosion resistance can be obtained, but there is a problem in terms of dew condensation whitening resistance.

  If the anti-condensation whitening resistance is poor, the steel sheet coil to which the surface treatment agent is applied may cause a phenomenon that moisture permeates from the end of the coil and the surface of the steel sheet is whitened, which may cause problems when the user uses the steel sheet. It was. In order to prevent the whitening that occurs in such a coil, the corrosion resistance decreases when the amount of silica particles or vanadium compound in the surface treatment agent is decreased.

Japanese Patent Laid-Open No. 2003-183587 Japanese Patent Laid-Open No. 2005-289837

  The problem to be solved by the invention is to provide a surface treatment agent capable of forming a surface-treated metal plate excellent in workability, corrosion resistance, anti-condensation whitening property and the like, and a steel sheet coated with the surface treatment agent.

The inventors have disclosed a surface treatment agent comprising a water-dispersible polyurethane resin (A), a rust inhibitor (B), a colloidal silica (C) treated with a silane coupling agent, and a basic alkali silicate (D). The colloidal silica (C) treated with a silane coupling agent, 5 to 50 parts by mass of a rust inhibitor (B) with respect to 100 parts by mass of the total solid content of the water-dispersible polyurethane resin (A). 10 to 150 parts by mass and basic alkali silicate (D) 30 to 110 parts by mass, and the rust inhibitor (B) contains a titanium compound (b1) and an organophosphate compound (b2). Further, it was found that the use of a surface treatment agent containing at least one selected from the vanadium compound (b3) and the zirconium compound (b4) can achieve the solution of the above problems. It came to complete Ming.

That is, the present invention relates to the following items:
1. A surface treatment agent containing a water-dispersible polyurethane resin (A), a rust inhibitor (B), a colloidal silica (C) treated with a silane coupling agent, and a basic alkali silicate (D), 5 to 50 parts by mass of the rust preventive agent (B) and 10 to 150 parts by mass of the colloidal silica (C) treated with the silane coupling agent with respect to 100 parts by mass of the solid content of the dispersible polyurethane resin (A). 30 to 110 parts by mass of basic alkali silicate (D) and the rust inhibitor (B) contains a titanium compound (b1) and an organic phosphate compound (b2), and further a vanadium compound ( A surface treating agent containing at least one selected from b3) and a zirconium compound (b4).

  2. Furthermore, in 1 item | term containing 0.1-160 mass parts colloidal silica (E) which has not performed the process by a silane coupling agent with respect to 100 mass parts of solid content total of water-dispersible polyurethane resin (A). The surface treating agent as described.

3. The film formation method which coat | covers the surface treating agent of 1 term | claim or 2 term | claim on a steel plate, and forms a film | membrane of 0.1-3.0 g / m < ² > by dry film weight.

  The surface treatment agent of the present invention can obtain a surface-treated steel sheet that is excellent in workability, corrosion resistance, condensation whitening resistance, and the like of the surface-treated plate.

  The surface treating agent of the present invention contains a specific rust preventive agent (B) in an amount of 5 to 100 parts by mass with respect to the total solid content of the water-dispersible polyurethane resin (A) and the water-dispersible polyurethane resin (A). 50 mass parts, 10-150 mass parts of colloidal silica (C) processed with the silane coupling agent, and 30-110 mass parts of basic alkali silicate (D) are characterized by the above-mentioned. Details will be described below.

Water dispersible polyurethane resin (A):
The surface treating agent of the present invention uses a polyurethane resin from the viewpoint of adhesion to the top coat film on the obtained film and processability. The water-dispersible polyurethane resin is a low molecular weight compound having two or more active hydrogens such as a diol and a diamine, if necessary, a polyurethane comprising a polyol and a diisocyanate such as polyester polyol and polyether polyol. The chain is elongated in the presence of an extender and is stably dispersed or dissolved in water, and known ones can be widely used.

  As a method for stably dispersing or dissolving the polyurethane resin in water, for example, the following methods can be used. (1) A method of imparting hydrophilicity by introducing an ionic group such as a hydroxyl group, an amino group, a carboxy group, or the like into the side chain or terminal of a polyurethane polymer, and dispersing or dissolving in water by self-emulsification; A method of forcibly dispersing a completed polymer or a polymer in which a terminal isocyanate group is blocked with a blocking agent such as oxime, alcohol, phenol, mercaptan, amine, sodium bisulfite, etc. in water using an emulsifier and mechanical shearing force; (3) A method in which a urethane prepolymer having a terminal isocyanate group is mixed with water, an emulsifier and an extender, and simultaneously dispersed and polymerized using mechanical shearing force; (4) As a polyol as a main polyurethane material Uses water-soluble polyols such as polyethylene glycol and is water-soluble polyurethane in water And a method of diffusing or dissolving the like. The molecular weight of the polyurethane resin is not particularly limited, but is preferably 10,000 to 1,000,000, preferably 50,000 to 500,000 in terms of weight average molecular weight.

  Examples of commercially available polyurethane resins include Hydran HW-330, Hydran HW-340, Hydran HW-350 (all manufactured by Dainippon Ink and Chemicals), Superflex 100, Superflex 130, Superflex 150, Superflex. 170 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekapon Tider HUX-206, Adekabon Tider HUX-232, Adekabon Tider HUX-360, Adekapon Tider HUX-540 (all manufactured by Adeka) and the like. be able to.

Rust preventive (B):
By containing the rust preventive agent (B), the surface treatment agent of the present invention can obtain a film having excellent corrosion resistance. Said rust preventive agent (B) contains a titanium compound (b1) and an organophosphate compound (b2), and further contains at least one metal salt selected from a vanadium compound (b3) and a zirconium compound (b4). contains. Hereinafter, each component contained in the rust inhibitor (B) will be described.

Titanium compound (b1)
Examples of the titanium compound (b1) include ammonium titanium fluoride, titanyl phosphate, titanium chloride, titanium sulfate, titanyl sulfate, titanium nitrate, titanyl nitrate, titanium hydrofluoric acid, a salt of fluorotitanic acid, titanium oxide, fluorine. Examples thereof include titanium fluoride. Preferably, titanium ammonium fluoride, titanium hydrofluoric acid, titanyl phosphate, etc. are mentioned.

  The titanium compound (b1) is 10 to 50 parts by mass, particularly 20 to 40 parts by mass based on the total solid content of 100 parts by mass of the rust inhibitor (B). It is preferable from the point. These titanium compounds (b1) can be used individually by 1 type or in mixture of 2 or more types.

Organophosphate compound (b2)
Examples of the organic phosphate compound (b2) include 1-hydroxymethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxypropane-1,1-diphosphonic acid, and the like. Suitable examples include -hydroxyphosphonoacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and salts thereof. In the present invention, titanyl phosphate is used not as an organic phosphate compound but as a titanium compound.

  The organic phosphoric acid compound (b2) has an effect of improving the storage stability of the rust inhibitor (B), and 1-hydroxyethane-1,1-diphosphonic acid is particularly preferable. The compounding amount of the organic phosphoric acid compound (b2) is 20 to 70 parts by mass, particularly 40 to 60 parts by mass based on the total solid content of 100 parts by mass of the rust inhibitor (B). From the viewpoint of stability and the like. These organophosphate compounds (b2) can be used alone or in combination of two or more.

Vanadium compound (b3)
Examples of the vanadium compound (b3) include lithium metavanadate, potassium metavanadate, sodium metavanadate, and ammonium metavanadate. Among them, ammonium metavanadate is particularly preferable from the viewpoint of stability and corrosion resistance.

  The compounding amount of the vanadium compound (b3) is 0 to 30 parts by mass, particularly 5 to 25 parts by mass, based on the total solid content of the rust inhibitor (B), from the viewpoint of corrosion resistance and the like. preferable. These vanadium compounds (b3) can be used individually by 1 type or in mixture of 2 or more types.

Zirconium compound (b4)
Examples of the zirconium compound (b4) include salts of zirconium hydrofluoric acid such as sodium, potassium, lithium, ammonium, zirconium nitrate, zirconium hydroxide, zirconium carbonate ammonium and the like. Among them, ammonium zirconium fluoride is corrosion resistant. From the viewpoints of storage stability and the like, ammonium zirconium carbonate is preferable.

  The compounding amount of the zirconium compound (b4) is 0 to 30 parts by mass, particularly 5 to 25 parts by mass based on the total solid content of 100 parts by mass of the rust inhibitor (B), in view of corrosion resistance and the like. preferable.

  The total amount of the vanadium compound (b3) and the zirconium compound (b4) is 5 to 60 parts by mass, particularly 10 to 50, based on 100 parts by mass of the solid content of the rust inhibitor (B). From the viewpoint of stability and corrosion resistance of the surface treatment agent. These zirconium compounds (b4) can be used individually by 1 type or in mixture of 2 or more types.

  The temperature and time for mixing each component in the preparation of the rust preventive agent (B) are 10 to 100 ° C., preferably 30 to 90 ° C. for 1 minute to 180 minutes, preferably 10 to 60 minutes. It is preferable to heat also from the surface which dissolves each component in water.

  In addition, the compounding ratio of the rust preventive agent (B) in the surface treating agent of the present invention is 5 to 50 parts by mass, preferably 6 to 35 with respect to 100 parts by mass in total of the solid content of the water dispersible polyurethane resin (A). Part by mass, more preferably 7 to 25 parts by mass is preferred for the stability of the surface treatment agent and for improving workability, corrosion resistance and condensation whitening resistance.

Colloidal silica (C) treated with a silane coupling agent:
The surface treating agent of the present invention contains colloidal silica (C) treated with a silane coupling agent (hereinafter sometimes abbreviated as “component (C)”). The colloidal silica (C) treated with the silane coupling agent is 1 to 50 parts by mass, preferably 3 to 30 parts by mass, more preferably 3 parts by mass with respect to 100 parts by mass of the solid content of the starting colloidal silica. Can be obtained by adding 5 to 20 parts by mass and reacting.

  In the reaction, the silane coupling agents are allowed to condense with each other or react rapidly with colloidal silica so that no increase in viscosity or gelation occurs. The temperature and time during the reaction are 10 to 100 ° C., preferably 40 to 90 ° C. for 1 minute to 180 minutes, preferably 10 to 60 minutes. Heating is also preferred in order to efficiently react the colloidal silica hydroxyl group with the silane coupling agent.

  Moreover, at the time of reaction of a silane coupling agent and colloidal silica, a metal compound, water-soluble resin, surfactant, etc. can also be mixed as needed.

  Examples of the silane coupling agent include vinyl methoxy silane, vinyl ethoxy silane, vinyl trichloro silane, vinyl trimethoxy silane, vinyl triethoxy silane, β- (3,4 epoxy cyclohexyl) ethyl trimethoxy silane, γ-glycol. Sidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ- Methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, p-styryltrimethoxysilane, γ -Acryloxypropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, γ-isocyanatopropyl Triethoxysilane, γ-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- (vinylbenzylamine) -β-aminoethyl-γ-aminopropylto Can be exemplified methoxy silane, you can use these alone or in combination of two or more.

  As commercially available products, KBM-403, KBM-502, KBM-503, KBM-603, KBE-903, KBM-603, KBE-602, KBE-603 (all trade names) manufactured by Shin-Etsu Silicone Co., Ltd. are used. be able to.

On the other hand, it is preferable to use colloidal silica obtained by stabilizing ultrafine particles of silicon dioxide (SiO ₂ ) with sodium and ammonium. The ultrafine particles of silicon dioxide (SiO ₂ ) are preferably spherical silica that has a high molecular weight by a siloxane bond and may have a hydroxyl group on the surface thereof. The size of the fine particles is preferably in the range of 1 to 50 nm, particularly 5 to 20 nm.

  Colloidal silica that can be used for the component (C) can be obtained as a commercial product. For example, Snowtex S, Snowtex NXS, Snowtex C (all manufactured by Nissan Chemical Industries, Ltd., trade name), Adelite AT-20A, Adelite AT-2045 (manufactured by Adeka Co., Ltd., trade name) and the like.

  Moreover, as said metal compound which may be mix | blended at the time of reaction, metal compounds, such as zirconium, titanium, zinc, aluminum, are mentioned, for example. Specifically, zirconium compounds include zirconium chloride, zirconyl chloride, zirconium sulfate, zirconyl sulfate, zirconium nitrate, zirconyl nitrate, zirconium hydrofluoric acid, zirconic fluoride salt, zirconium oxide, zirconyl bromide, zirconyl acetate, Examples thereof include zirconyl carbonate and zirconium fluoride.

  Examples of the titanium compound include titanium chloride, titanium sulfate, titanyl sulfate, titanium nitrate, titanyl nitrate, titanium hydrofluoric acid, a salt of fluorinated titanic acid, titanium oxide, and titanium fluoride.

  Examples of the zinc compound include zinc acetate, zinc lactate, zinc oxide, and zinc nitrate. Examples of the aluminum compound include aluminum nitrate.

  The water-soluble resin is a resin other than the urethane resin, such as an aqueous dispersion of acrylic resin, poly (N-vinylacetamide), polyvinylpyrrolidone, polyacrylamide, polyethylene glycol, water-soluble nylon, oxidized starch, etc. Can be mentioned.

  The surfactant may be any of a nonionic surfactant, an anionic surfactant, a cationic surfactant, and a zwitterionic surfactant. Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene compound, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene Examples thereof include ethylene alkylamine and alkylalkanolamide. Examples of the anionic surfactant include fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, and alkyl phosphates. Examples of the cationic surfactant include alkylamine salts and quaternary ammonium salts. Examples of the zwitterionic surfactant include alkylbedine.

  The content of the colloidal silica (C) treated with the silane coupling agent in the surface treatment agent of the present invention is silane coupling to the total solid content of 100 parts by mass of the water-dispersible polyurethane resin (A). 10 to 150 parts by mass, preferably 12 to 100 parts by mass, and more preferably 15 to 80 parts by mass of colloidal silica (C) treated with the agent is good for corrosion resistance and resistance to condensation whitening.

Basic alkali silicate (D):
In the surface treating agent of the present invention, a basic alkali silicate (D) is blended. Examples of the basic alkali silicate (D) include sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. Among these, sodium silicate is preferable from the improvement of condensation whitening resistance.

  The content of the basic alkali silicate (D) is 30 to 110 parts by mass, preferably 35 to 105 parts by mass with respect to 100 parts by mass of the total solid content of the water-dispersible polyurethane resin (A). Preferably 40-100 mass parts containing is good from the surface of stability and corrosion resistance of a surface treating agent.

Colloidal silica not treated with silane coupling agent (E)
The surface treatment agent of the present invention can contain colloidal silica (E) not treated with a silane coupling agent (hereinafter referred to as “untreated colloidal silica (E)”) according to the required performance. . Specifically, the starting material colloidal silica described in the section of the component (C) can be suitably used. SNOWTEX NXS, SNOWTEX XS (both manufactured by Nissan Chemical Industries, Ltd., trade name) Adelite AT- 20A (manufactured by Adeka) and the like.

  The content of the untreated colloidal silica (E) is 0.1 to 160 parts by weight, preferably 50 to 150 parts by weight, more preferably 100 parts by weight based on the total solid content of the water-dispersible polyurethane resin (A). 90 to 145 parts by mass is good for corrosion resistance.

  In addition to the components described above, the surface treatment agent of the present invention includes, for example, a lubricating function imparting agent, a thickener, a repellency inhibitor, an antifoaming agent, a surfactant, an oxidizing agent, a fungicide, and a rust inhibitor ( Tannic acid, phytic acid, benzotriazole, etc.), colored pigments, extender pigments, rust preventive pigments, conductive pigments and the like. Moreover, you may add hydrophilic solvents, such as methanol, ethanol, isopropyl alcohol, an ethylene glycol solvent, and a propylene glycol solvent, as needed.

Production of surface-treated metal plate In the surface treatment agent of the present invention, the conventional chromate treatment step can be omitted, such as untreated cold-rolled steel sheet, aluminum plate, etc .; untreated galvanized steel sheet, aluminum-plated steel sheet, etc. By directly applying and drying the plated steel sheet, a metal plate having excellent workability, corrosion resistance and dew condensation whitening resistance can be obtained.

  Examples of the galvanized steel sheet include an electrogalvanized steel sheet, a hot dip galvanized steel sheet, a nickel-zinc alloy plated steel sheet, and a zinc-aluminum alloy plated steel sheet. As a zinc-aluminum-plated steel plate, in the case of a metal plate whose main component is zinc, 5% Al-Zn steel plate, 8% Al-Zn steel plate, 15% Al-Zn steel plate, etc. Examples of the metal plate as the main component of plating include 55% Al—Zn steel plate and 75% Al—Zn steel plate. In addition, a composite mainly composed of aluminum and zinc in which Mg, Mn, Si, Ti, Ni, Co, Pb, Sn, Cr, rare metals (La, Ce, Y, Nb, etc.), etc. are added to an Al-Zn alloy. It can also be applied to plated steel sheets.

The surface treatment agent of the present invention is used by being applied to the metal plate, and the coating amount is 0.1 to 3.0 g / m ² , more preferably 0.5 to 3.0 g / m by dry film weight. ² is desirable.

  When the surface treatment agent of the present invention is applied to a steel sheet to form a film, the viscosity of the surface treatment agent is appropriately adjusted to 5 to 30 mPa · s depending on the application amount with a diluent such as water, and then roll coater coating, spray coating The coating is applied to a predetermined film weight by a generally known method such as dipping. Then, it is dried for 10 to 40 seconds at an ambient temperature of 150 to 250 ° C. At this time, the maximum ultimate temperature (PMT) of the metal plate is preferably in the range of 90 to 160 ° C. By coating and drying the surface treatment agent in this manner, a metal plate excellent in workability, corrosion resistance, condensation whitening resistance, and the like is produced.

  Hereinafter, the present invention will be described in more detail with reference to Production Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. In each example, “parts” indicates mass parts, and “%” indicates mass%.

Production Example 1 Anticorrosive No. Example 1
In a glass beaker, 400 parts of deionized water, 24 parts of titanium ammonium fluoride, 46 parts of 1-hydroxymethane-1,1-diphosphonic acid, 12 parts of ammonium metavanadate, 8 parts of ammonium zirconium fluoride, 10 parts of ammonium zirconium carbonate The mixture was stirred and heated at 80 ° C. for 2 hours, and then allowed to cool to prevent rust preventive No. 1 was obtained.

Production Examples 2-8
A rust preventive No. having a solid content of 20% was prepared in the same manner as in Production Example 1 except that the contents of Table 1 were used. 2-No. 8 was obtained.

Production and production example 9 of colloidal silica (C) treated with a silane coupling agent Production Example 1 Snowtex NXS (particle size: about 5 nm, SiO ₂ concentration: 15 mass%, manufactured by Nissan Chemical Industries, Ltd.) 667 parts (solid content: 100 parts), glass reaction equipped with a stirrer with an internal volume of 1 L I put it in a vessel. To this was added 20 parts (solid content) of KBM-403 (manufactured by Shin-Etsu Silicone Co., Ltd., trade name, 3-glycidoxypropyltrimethoxysilane) with 30 parts of ethanol, and the mixture was stirred uniformly. The mixture was heated to 95 ° C. and stirred for 2 hours, and modified silica No. 1 which was colloidal silica treated with a silane coupling agent. 1 was obtained.

Production Example 10 Modified silica No. Production Example 2 No. ₂ glass reactor equipped with a stirrer with an internal volume of 1 L of Snowtex NXS (particle size: about 5 nm, SiO ₂ concentration: 15% by mass, manufactured by Nissan Chemical Industries, Ltd.) 667 parts (solid content: 100 parts) Was charged. To this was added 10 parts (solid content) of KBM-503 (manufactured by Shin-Etsu Silicone Co., Ltd., trade name, 3-methacryloxypropyltrimethoxysilane) mixed with 30 parts of ethanol, and after stirring uniformly, the mixture was 95. The modified silica No. which is colloidal silica heated to ℃ and stirred for 2 hours and treated with a silane coupling agent. 2 was obtained.

Production Example 11 Modified Silica No. Production Example 3 No. 3 glass reactor equipped with a stirrer with an internal volume of 1 L of Snowtex NXS (particle size: about 5 nm, SiO ₂ concentration: 15 mass%, manufactured by Nissan Chemical Industries, Ltd.) 667 parts (solid content: 100 parts) Was charged. To this was added 5 parts (solid content) of KBE-903 (manufactured by Shin-Etsu Silicone Co., Ltd., trade name, 3-aminopropyltriethoxysilane) mixed with 7.5 parts of ethanol, and the mixture was stirred uniformly. Heated to 95 ° C. and stirred for 2 hours, modified silica No. 1 which is colloidal silica treated with a silane coupling agent. 3 was obtained.

Production Example 12 Modified silica No. 4 Production Example Snow Rex NXS (particle size: about 5 nm, SiO ₂ concentration: 15% by mass, manufactured by Nissan Chemical Industries, Ltd.) 667 parts (solid content: 100 parts) equipped with a 1 L internal volume stirrer Was charged. To this was added KBM-403 (manufactured by Shin-Etsu Silicone Co., Ltd., trade name, 3-glycidoxypropyltrimethoxysilane) 5 parts (solid content) with 30 parts of ethanol, and after stirring uniformly, 5 parts (solid content) of ammonium metavanadate was added and stirred, and the mixture was heated to 95 ° C. and further stirred for 2 hours, and modified silica No. 1 which was colloidal silica treated with a silane coupling agent. 4 was obtained.

Production Example 13 Modified Silica No. 5 Production Example Snowtex NXS (particle diameter: about 5 nm, SiO ₂ concentration: 15 mass%, manufactured by Nissan Chemical Industries, Ltd.) 667 parts (solid content: 100 parts) equipped with a 1 L internal volume stirrer Was charged. To this, 10 parts of KBM-403 (manufactured by Shin-Etsu Silicone, trade name, 3-glycidoxypropyltrimethoxysilane) (solid content) mixed with 70 parts of ethanol was added and stirred uniformly, and then metavanadate acid was added. 5 parts (solid content) of ammonium and 5 parts (solid content) of zirconium carbonate ammonium (solid content) were added, stirred, heated to 95 ° C. and stirred for 2 hours, and modified silica No. 1 which was colloidal silica treated with a silane coupling agent. 5 was obtained.
In Table 2 below, modified silica No. 1-No. The content of 5 is shown.

Production Examples 1-18 of Surface Treatment Agent
The components shown in Tables 3 and 4 below were mixed thoroughly with a stirrer, and deionized water was added to adjust the solid content to obtain a surface treatment agent No. 20 having a solid content of 20%. 1-No. 18 was created.

(Note 1) Adekapon Tider HUX-206: Made by Adeka, trade name, water-dispersible polyurethane resin (Note 2) Adeka Pontideer HUX-540: Made by Adeka, trade name, water-dispersible polyurethane resin (Note 3) Superflex 150: Daiichi Kogyo Seiyaku Co., Ltd., trade name, water-dispersible polyurethane resin (Note 4) Superflex 500: Daiichi Kogyo Seiyaku Co., Ltd., trade name, water-dispersible polyurethane resin (Note 5) Snowtex NXS: Nissan Chemical Industries, trade name, colloidal silica, particle size 5mm
(Note 6) Adelite AT-2045: manufactured by Adeka, trade name, colloidal silica,
Average particle size 5 nm.

Comparative Examples 1-8
Each component shown in Table 5 below was thoroughly mixed with a stirrer, deionized water was added to adjust the solid content, and the surface treatment agent No. 19-No. 26 was created.

Preparation of surface treated plate and performance evaluation example 19
Surface treatment agent No. 5 was applied to a hot dip galvanized steel sheet (plate thickness 0.6 mm, plating basis weight 100 g / m ² ). No. 1 was coated with a roll coater so that the dry film would be 0.5 g / m ^2, and dried for 10 seconds at an ambient temperature of 230 ° C. 1 was created.

Examples 20-36
Surface treatment agent No. 2-No. The surface treatment plate No. 18 was used in the same manner as in Example 1 except that 18 was used. 2-No. 18 was obtained. The obtained surface-treated plate was subjected to the test according to the test method described later. The results are shown in Tables 6-7.

Comparative Examples 9-16
Surface treatment agent No. 19-No. The surface treatment plate No. 26 was used in the same manner as in Example 1 except that No. 26 was used. 19-No. 26 was obtained. The obtained surface-treated plate was subjected to the test according to the test method described later. The results are shown in Table 8.

Test Method (Note 7) Film Appearance: For each surface-treated plate, the film appearance was visually evaluated according to the following criteria:
B, the film is a smooth continuous film and transparent;
C, the film is a smooth continuous film, but is quite cloudy or highly colored;
D does not result in a smooth continuous film.

(Note 8) Workability: For each surface-treated plate, a metal thin plate deep drawing tester type 142 manufactured by Eriksen was used, and a deep drawing processing test was performed under the following conditions:
・ Test temperature 20 ℃ and 80 ℃
・ Seat holder pressure 1500Kg
・ Punch diameter 50mm
・ Blank diameter 110mm
・ Aperture ratio 2.2
・ Processing speed 10mm / sec
The processed test plate was visually evaluated according to the following criteria:
A: There is no deposit on the die and no scratches are observed on the surface of the workpiece;
B: There is a small amount of deposit on the die, and a slight scratch is observed on the surface of the workpiece;
C: There is a little more deposit on the die and a lot of scratches on the surface of the work piece;
D: A large amount of deposits are present on the die, and significant scratches are observed on the entire surface of the workpiece.

(Note 9) Corrosion resistance: A salt spray test was conducted according to JIS Z-2371. The test time was 360 hours for the “flat plate” before processing, and 240 hours for the sample obtained in the above “workability” test, and was evaluated according to the following criteria from the degree of rust generation:
A shows no rusting at all;
B is rusted in an area of less than 5%;
C is rusted in an area of 5% or more and less than 20%;
As for D, generation | occurrence | production of rust is recognized by 20% or more of area.

(Note 10) Condensation whitening resistance: 1 ml of deionized water was dropped on each surface-treated plate with a dropper, allowed to dry at room temperature, and evaluated according to the following evaluation criteria:
A is no trace;
B is slightly traced;
C is slightly discolored;
In D, considerable discoloration is recognized.

(Note 11) Treatment agent stability:
500 g of each surface treatment agent was put in a glass container having an internal volume of 1 L, sealed, and stored in a constant temperature room at 40 ° C. for 14 days. Then, it returned to room temperature, the state in a container was observed visually, and the following references | standards evaluated:
A: Good without soft caking or separation B: Soft caking or separation is observed, but becomes uniform by stirring for 10 minutes or less,
C: Soft caking and separation are recognized, and it becomes uniform with stirring for more than 10 minutes and less than 60 minutes.
D: Hard caking and separation are recognized, and it is not uniform even with stirring exceeding 60 minutes.

(Note 12) Overall evaluation:
In the field of the surface treatment to which the present invention belongs, it is desirable that the surface appearance of the surface-treated plate, the workability, the corrosion resistance and the dew whitening resistance, and the treatment agent stability are all excellent. Therefore, a comprehensive evaluation was performed based on the following criteria:
A: Film appearance, workability, corrosion resistance, condensation whitening resistance and processing agent stability are all A or B evaluation, and there is at least one A evaluation;
B: The above five items are all B evaluations;
C: The above five items are all A, B or C evaluation, and there is at least one C evaluation;
D: There is at least one item of D evaluation.

  Home appliances and automobile steel sheets having excellent workability, corrosion resistance, and condensation whitening resistance can be obtained.

Claims (3)

A surface treatment agent containing a water-dispersible polyurethane resin (A), a rust inhibitor (B), a colloidal silica (C) treated with a silane coupling agent, and a basic alkali silicate (D), 5 to 50 parts by mass of the rust preventive agent (B) and 10 to 150 parts by mass of the colloidal silica (C) treated with the silane coupling agent with respect to 100 parts by mass of the solid content of the dispersible polyurethane resin (A). 30 to 110 parts by mass of basic alkali silicate (D) and the rust inhibitor (B) contains a titanium compound (b1) and an organic phosphate compound (b2), and further a vanadium compound ( A surface treating agent containing at least one selected from b3) and a zirconium compound (b4). Furthermore, 0.1-160 mass parts of colloidal silica (E) which has not performed the process by a silane coupling agent with respect to the solid content total 100 mass parts of a water-dispersible polyurethane resin (A) is contained. The surface treating agent as described in. The film formation method which coats the surface treating agent of Claim 1 or 2 on a steel plate, and forms a film of 0.1-3.0 g / m < ² > by dry film weight.