JP2008208410A - Surface-treated steel sheet, and steel sheet coated with organic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-treated steel sheet which has a film containing no hexavalent chromium thereon, has superior corrosion resistance, thermal discoloration resistance and blackening resistance, and further has excellent adhesiveness with an organic resin layer to be formed on the upper surface of the steel sheet. <P>SOLUTION: The surface treatment composition (J) includes: a titanium-containing aqueous liquid (A) of 100 parts by mass in terms of a solid content, which is obtained by mixing a titanium compound such as a hydrolyzable titanium compound and a low condensate thereof with hydrogen peroxide water; a nickel compound (B) of 0.01 to 10 parts by mass with respect to the aqueous liquid (A); an aluminum compound (C) of 1 to 100 parts by mass; a fluorine-containing compound (D) of 1 to 800 parts by mass; and further silicon oxide (E) of 20 to 90 mass% by a ratio to the whole solid content in the composition. The surface-treated steel sheet has the film with a coating weight of 0.1 to 2.0 g/m<SP>2</SP>on the surface, which has been formed by applying the surface treatment composition (J) onto the surface of a zinc-base plated steel sheet or an aluminum-base plated steel sheet, and drying the applied composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surface-treated steel sheet suitable for use in automobiles, home appliances, and building materials, and relates to an environment-adaptive surface-treated steel sheet containing no hexavalent chromium in the surface-treated film and an organic resin-coated steel sheet using the same. is there.

  Conventionally, steel plates for home appliances, steel plates for building materials, and steel plates for automobiles have been used for the purpose of improving corrosion resistance (white rust resistance, red rust resistance) on the surface of zinc-plated steel sheets or aluminum-plated steel sheets. Steel plates subjected to chromate treatment with a treatment liquid containing chromic acid or a salt thereof as a main component are widely used. This chromate treatment is an economical treatment method that is excellent in corrosion resistance and can be performed relatively easily.

  The chromate treatment uses hexavalent chromium which is a pollution control substance, but this hexavalent chromium is treated in a closed system in the treatment process, and the sealing action by the organic film formed in the upper layer causes the chromate film to contain Since the elution of chromium from can be made almost zero, the human body and the environment are not substantially polluted by hexavalent chromium. However, with increasing interest in global environmental issues in recent years, not only legal regulations that place emphasis on the conventional work environment and wastewater treatment, but also regulations that place emphasis on the environmental load and environmental harmony are beginning. In addition, with the background of the times when manufacturers are evaluated by their degree of environmental contribution, there is an increasing trend to reduce the use of heavy metals including hexavalent chromium.

  Under such a background, many white rust suppression techniques (chromate-free techniques) for zinc-based plated steel sheets that do not use hexavalent chromium have been proposed. For example, Patent Documents 1 and 2 propose a surface treatment agent containing Al, a phosphoric acid compound, silica, and a water-based organic resin emulsion, and a metal material coated therewith. Patent Document 3 proposes a galvanized steel sheet in which an organic coating layer is formed after an amorphous film is formed by applying and drying a mixed aqueous solution of polyphosphate primary phosphate and metal oxide sol. Has been. Further, in Patent Documents 4 and 5, a composite oxide film layer containing oxide fine particles, phosphoric acid and / or a phosphoric acid compound, and one or more metals selected from Mg, Mn, and Al is used as a lower layer. A steel sheet having an organic film formed thereon is proposed.

Japanese Patent Laid-Open No. 11-350157 JP 2000-26980 A JP 2000-129460 A JP 2002-53979 A JP 2002-53980 A

  Among the applications to which galvanized steel sheets are applied, there are not a few parts that are heated in a temperature range (about 500 to 600 ° C.) above the melting point of zinc. For example, in a heat exchanger in an air conditioner outdoor unit, when brazing a copper tube and an aluminum evaporator, a zinc-based plated steel sheet is placed between the copper tube and the evaporator to prevent melting of the aluminum by heating using a gas burner. Thus, the flame of the burner is prevented from touching the aluminum directly. When the above-described surface-treated steel sheet according to the prior art is applied to such a use, it is a film mainly composed of an organic resin, so that it is discolored to yellow or brown by thermal decomposition, resulting in poor appearance. For this reason, it is almost impossible to apply the surface-treated steel sheet of the prior art.

In order to solve such a problem, a chromate-free technique excellent in heat discoloration has been proposed. For example, Patent Documents 6 and 7 propose an inorganic rich film mainly composed of Mg-phosphate, colloidal silica, and a phosphonic acid compound. Patent Document 8 proposes a two-layer coating in which an inorganic rich coating mainly composed of primary phosphate and colloidal silica is disposed as a lower layer, and a silicate coating and / or a silicon resin is disposed as an upper layer.
JP 2000-79370 A JP 2001-348672 A JP 2004-91826 A

  However, the inorganic rich coatings of Patent Documents 6 and 7 have extremely low corrosion resistance levels and are difficult to apply as a chromate coating substitute. On the other hand, the two-layer coating of Patent Document 8 has a corrosion resistance level applicable as a chromate coating substitute, but has a problem in terms of cost because it uses expensive silicate or silicon resin. In addition, the coatings produced by these technologies are subject to a phenomenon of black discoloration (black discoloration) in a humid environment, making it difficult to apply to heat exchangers that are subject to dew condensation, and the storage environment during product transportation. Are also impractical and impractical.

  In addition, in organic resin-coated steel sheets such as coated steel sheets and laminated steel sheets, the adhesion of the organic resin layer is an important performance, but the conventional phosphating treatment that is performed as a base treatment has a crystalline film. Crystals are destroyed by strict processing, and the adhesion of the organic resin layer tends to be lowered. In particular, in the case of a coated steel sheet or a laminated steel sheet in which the thickness of the organic resin layer is 100 μm or more, the phosphate film is destroyed when the steel sheet is processed, and the organic resin layer is easily peeled off starting from this portion.

  For such problems, for example, in Patent Documents 3 to 5 cited above, the plating metal on the substrate reacts with the treatment liquid to form a very thin film of poorly soluble phosphate, thereby providing corrosion resistance and paint adhesion. However, even when such a surface-treated steel sheet is used for an organic resin-coated steel sheet, the adhesion and corrosion resistance when processed are likely to deteriorate. In particular, in the case of an organic resin-coated steel sheet having an organic resin layer with a thickness of 100 μm or more, since the film strength is high, a strong shearing force acts on the interface between the organic resin layer and its base during deformation, and the organic resin layer Peeling easily occurs.

Therefore, the object of the present invention is to solve such a problem of the prior art, and the surface treatment film does not contain hexavalent chromium at all, and has excellent corrosion resistance, heat discoloration resistance and blackening resistance, and is formed in the upper layer. An object of the present invention is to provide a surface-treated steel sheet capable of obtaining excellent adhesion with an organic resin layer to be obtained, particularly excellent adhesion at the time of deformation of a thick organic resin layer having a thickness of 100 μm or more.
Another object of the present invention is to provide an organic resin-coated steel sheet using such a surface-treated steel sheet.

  The inventors of the present invention have studied a coating composition that can solve the above-mentioned problems, and as a result, on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, a nickel compound, an aluminum compound, a specific titanium-containing aqueous liquid, Surface treatment film using a surface treatment composition in which a fluorine-containing compound and silicon oxide are added in a predetermined ratio and, if necessary, an organic phosphoric acid compound, vanadic acid compound, zirconium carbonate compound, and an aqueous organic resin are added in appropriate amounts. In addition to having excellent corrosion resistance, heat discoloration resistance and blackening resistance, it has excellent adhesion to an organic resin layer formed as an upper layer, particularly a thick organic resin layer having a thickness of 100 μm or more. It has been found that a surface-treated steel sheet can be obtained.

Since this invention was made | formed based on such knowledge, it makes the following a summary.
[1] At least one selected from a hydrolyzable titanium compound, a hydrolyzable titanium compound low-condensate, titanium hydroxide, and a titanium hydroxide low-condensate on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet 0.01-10 parts by mass of nickel compound (B), aluminum compound (C) with respect to 100 parts by mass of solid content of titanium-containing aqueous liquid (A) obtained by mixing a seed titanium compound with aqueous hydrogen peroxide. 1 to 100 parts by mass, 1 to 800 parts by mass of the fluorine-containing compound (D), and further 20 to 90 mass% of silicon oxide (E) in the total solid content of the surface treatment composition. A surface-treated steel sheet having a surface-treated film having a film adhesion amount of 0.1 to 2.0 g / m ² formed by applying and drying the surface-treated composition (J).

[2] The surface-treated steel sheet according to [1], wherein the fluorine-containing compound (D) is at least one selected from zircon ammonium fluoride and zircon hydrofluoric acid.
[3] In the surface-treated steel sheet according to [1] or [2], the surface treatment composition (J) further adds an organophosphate compound (F) to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). The surface-treated steel sheet is characterized by containing 1 to 400 parts by mass.
[4] In the surface-treated steel sheet according to any one of [1] to [3], the surface treatment composition (J) further contains a vanadic acid compound (G) in a solid content of the titanium-containing aqueous liquid (A) of 100 mass. 1 to 400 parts by mass with respect to parts.

[5] In the surface-treated steel sheet according to any one of the above [1] to [4], the surface treatment composition (J) further contains a zirconium carbonate compound (H) in a solid content of the titanium-containing aqueous liquid (A) of 100 mass. 1 to 400 parts by mass with respect to parts.
[6] In the surface-treated steel sheet according to any one of [1] to [5], the surface treatment composition (J) further contains a water-soluble organic resin and / or a water-dispersible organic resin (I) in a titanium-containing aqueous solution. A surface-treated steel sheet comprising 80 parts by mass or less with respect to 100 parts by mass of the solid content of the liquid (A).
[7] An organic resin-coated steel sheet having an organic resin layer on the surface-treated film of the surface-treated steel sheet according to any one of [1] to [6].

The surface-treated steel sheet of the present invention has excellent corrosion resistance and blackening resistance comparable to the chromate film because the surface-treated film made of a specific inorganic component has a high barrier property. In addition, the film is colored by heating. In addition, it has excellent heat discoloration resistance that hardly causes discoloration, and also has excellent adhesiveness when the steel plate is deformed in an organic resin layer formed as an upper layer, particularly a thick organic resin layer having a thickness of 100 μm or more.
In addition, the organic resin-coated steel sheet of the present invention is excellent in corrosion resistance, blackening resistance, and heat discoloration, and is excellent in adhesion of an organic resin layer, particularly in a thick organic resin layer having a thickness of 100 μm or more. Yes.

  The surface-treated steel sheet of the present invention is a hydrolyzable titanium compound, a hydrolyzable titanium compound low condensate, a titanium hydroxide, or a titanium hydroxide low condensate on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet. A titanium-containing aqueous liquid (A) obtained by mixing at least one titanium compound selected from the group consisting of hydrogen peroxide and a nickel compound (B), an aluminum compound (C), and a fluorine-containing compound (D ) And silicon oxide (E) in a predetermined ratio, and if necessary, an organic phosphate compound (F), a vanadic acid compound (G), a zirconium carbonate compound (H), a water-soluble organic resin or And / or having a surface treatment film with a predetermined film adhesion amount formed by applying and drying a surface treatment composition (J) containing at least one water dispersible organic resin (I) in a predetermined ratio. Is shall. This surface treatment film does not contain hexavalent chromium.

Examples of the galvanized steel sheet used as the base of the surface-treated steel sheet of the present invention include a galvanized steel sheet, a Zn—Ni alloy plated steel sheet, a Zn—Fe alloy plated steel sheet (electroplated steel sheet, galvannealed steel sheet), Zn -Cr alloy plated steel sheet, Zn-Mn alloy plated steel sheet, Zn-Co alloy plated steel sheet, Zn-Co-Cr alloy plated steel sheet, Zn-Cr-Ni alloy plated steel sheet, Zn-Cr-Fe alloy plated steel sheet, Zn-Al Alloy-plated steel sheets (for example, Zn-5 mass% Al alloy-plated steel sheets, Zn-55 mass% Al alloy-plated steel sheets), Zn-Mg alloy-plated steel sheets, Zn-Al-Mg alloy-plated steel sheets, and plating of these plated steel sheets metal oxides, dispersed zinc composite-plated steel sheet such as a polymer (e.g., Zn-SiO ₂ dispersion plating steel plate) used like in the coating Door can be. Moreover, the multilayer plating steel plate which plated two or more layers of the same kind or different kind among the above plating can also be used.

Moreover, as an aluminum system plated steel plate used as the base of the surface treatment steel plate of this invention, an aluminum plating steel plate, an Al-Si alloy plating steel plate, etc. can be used.
Moreover, as a plated steel plate, the steel plate surface may be previously plated with lightness such as Ni, and various plating as described above may be performed thereon.
As a plating method, any feasible method among an electrolytic method (electrolysis in an aqueous solution or electrolysis in a nonaqueous solvent), a melting method, and a gas phase method can be adopted.
In addition, when the surface treatment film is formed on the surface of the plating film, alkali degreasing, solvent degreasing, surface conditioning treatment (alkaline surface conditioning) is performed on the surface of the plating film as necessary in order to prevent film defects and unevenness from occurring. Treatment or acidic surface conditioning treatment) can be performed.

In addition, for the purpose of preventing blackening in the usage environment (a kind of oxidation phenomenon on the plating surface), an iron group metal ion (one or more of Ni ion, Co ion, Fe ion) is previously applied to the plating surface as necessary. Surface adjustment treatment with an acidic or alkaline aqueous solution containing can also be performed.
When using an electrogalvanized steel sheet as the base steel sheet, iron group metal ions (one or more of Ni ions, Co ions, Fe ions) are added to the electroplating bath for the purpose of preventing blackening, and the plating film These metals can be contained in an amount of 1 ppm or more. In this case, there is no particular limitation on the upper limit of the iron group metal concentration in the plating film.

In the surface-treated steel sheet of the present invention, the surface-treated film formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet includes a titanium-containing aqueous liquid (A), a nickel compound (B), an aluminum compound (C), and a fluorine-containing film. It is formed by applying and drying a surface treatment composition (J) containing the compound (D) and silicon oxide (E) as essential components.
The titanium-containing aqueous liquid (A) contains at least one titanium compound selected from hydrolyzable titanium compounds, hydrolyzable titanium compound low condensates, titanium hydroxide and titanium hydroxide low condensates. It is an aqueous liquid containing titanium obtained by mixing with hydrogen oxide water.

The hydrolyzable titanium compound is a titanium compound having a hydrolyzable group directly bonded to titanium, and generates titanium hydroxide by reacting with water such as water or water vapor. The hydrolyzable titanium compound may be one in which all of the groups bonded to titanium are hydrolyzable groups, or a part of the groups bonded to titanium may be hydrolyzable groups.
The hydrolyzable group is not particularly limited as long as it generates titanium hydroxide by reacting with moisture as described above. For example, a lower alkoxyl group or a group that forms a salt with titanium (for example, Halogen atoms such as chlorine, hydrogen atoms, sulfate ions, etc.).

The hydrolyzable titanium compound containing a lower alkoxyl group as the hydrolyzable group is particularly represented by the general formula Ti (OR) ₄ (wherein R represents the same or different alkyl groups having 1 to 5 carbon atoms). Tetraalkoxy titanium is preferred. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, and a tert-butyl group. Can be mentioned.
Typical examples of the hydrolyzable titanium compound having a group capable of forming a salt with titanium as a hydrolyzable group include titanium chloride and titanium sulfate.

Moreover, the low condensate of a hydrolysable titanium compound is a low condensate of the above-mentioned hydrolysable titanium compounds. The low condensate may be one in which all of the groups bonded to titanium are hydrolyzable groups, or a part of the groups bonded to titanium may be hydrolyzable.
For hydrolyzable titanium compounds whose hydrolyzable group forms a salt with titanium (for example, titanium chloride, titanium sulfate, etc.), an aqueous solution of the hydrolyzable titanium compound and an alkaline solution such as ammonia or caustic soda are used. Orthotitanic acid (titanium hydroxide gel) obtained by the reaction can also be used as a low condensate.

As the low condensate of the hydrolyzable titanium compound and the low condensate of titanium hydroxide, a compound having a condensation degree of 2 to 30 can be used, and a compound having a condensation degree of 2 to 10 is particularly preferable. When the condensation degree exceeds 30, a white precipitate is formed when mixed with hydrogen peroxide, and a stable titanium-containing aqueous liquid cannot be obtained.
The hydrolyzable titanium compounds, low condensates of hydrolysable titanium compounds, titanium hydroxide, and low condensates of titanium hydroxide can be used alone or in combination of two or more thereof. Tetraalkoxy titanium which is a hydrolyzable titanium compound represented by the formula is particularly preferable.

As the titanium-containing aqueous liquid (A), any conventionally known liquid can be used without particular limitation as long as it is an aqueous liquid containing titanium obtained by mixing the above-described titanium compound and hydrogen peroxide solution. Specifically, the following can be mentioned.
(I) A titanyl ion hydrogen peroxide complex or an aqueous solution of titanic acid (peroxotitanium hydrate) obtained by adding hydrogen peroxide to a hydrous titanium oxide gel or sol (JP-A 63-35419, JP-A 1-2224220 gazette).

(Ii) A liquid for forming a titania film obtained by synthesizing a titanium hydroxide gel produced from an aqueous solution of titanium chloride or titanium sulfate and a basic solution with a hydrogen peroxide solution (Japanese Patent Laid-Open No. 9-71418, (See Kaihei 10-67516).
When obtaining this titania film-forming liquid, titanium hydroxide gel called orthotitanic acid is precipitated by reacting an aqueous solution of titanium chloride or titanium sulfate having a salt-forming group with titanium and an alkaline solution such as ammonia or caustic soda. Let Next, the titanium hydroxide gel is separated by decantation with water, washed thoroughly with water, further added with hydrogen peroxide water, and excess hydrogen peroxide is decomposed and removed, whereby a yellow transparent viscous liquid can be obtained.

The precipitated orthotitanic acid is in a gel state polymerized by polymerization of OH or hydrogen bonds, and cannot be used as an aqueous liquid containing titanium as it is. When hydrogen peroxide solution is added to this gel, a part of OH is in a peroxidized state, dissolved as a peroxotitanate ion or in a kind of sol state in which the polymer chain is divided into low molecules, and excess hydrogen peroxide Is decomposed into water and oxygen, and can be used as an aqueous liquid containing titanium for forming an inorganic film.
Since this sol contains only oxygen and hydrogen atoms in addition to titanium atoms, when it is changed to titanium oxide by drying or firing, only water and oxygen are generated, so carbon components necessary for thermal decomposition such as sol-gel method and sulfate Further, it is not necessary to remove the halogen component, and a titanium oxide film having a relatively high density can be formed even at a low temperature.

(Iii) Hydrogen peroxide is added to an aqueous solution of an inorganic titanium compound such as titanium chloride or titanium sulfate to form peroxotitanium hydrate, and then the solution obtained by adding a basic substance is allowed to stand or be heated to allow peroxo A titanium oxide forming solution obtained by forming a precipitate of a titanium hydrate polymer, and then removing hydrogen and other dissolved components derived from at least a titanium-containing raw material solution (Japanese Patent Application Laid-Open 2000-247638, JP-A-2000-247639).

The titanium-containing aqueous liquid (A) using a hydrolyzable titanium compound and / or a low condensate thereof as a titanium compound (hereinafter referred to as “hydrolyzable titanium compound a” for convenience of explanation) contains hydrolyzable titanium compound a. It can be obtained by reacting with hydrogen oxide water at a reaction temperature of 1 to 70 ° C. for about 10 minutes to 20 hours.
In the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a, the hydrolyzable titanium compound a is hydrolyzed with water by reacting the hydrolyzable titanium compound a with hydrogen peroxide. A product obtained by producing a hydroxyl group-containing titanium compound and then coordinating hydrogen peroxide to this hydroxyl group-containing titanium compound, and this hydrolysis reaction and coordination by hydrogen peroxide occur simultaneously. It produces a chelate solution that is extremely stable at room temperature and can withstand long-term storage. The titanium hydroxide gel used in the conventional manufacturing method is partially three-dimensionalized by Ti—O—Ti bonds, and the titanium-containing aqueous liquid (A) obtained by reacting this gel with hydrogen peroxide is composition and stable. Sex is essentially different.

  Further, when the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a is heated or autoclaved at 80 ° C. or higher, a titanium oxide dispersion containing ultrafine particles of crystallized titanium oxide is obtained. When the heat treatment or autoclave treatment is less than 80 ° C., crystallization of titanium oxide does not proceed sufficiently. The titanium oxide dispersion thus produced has an average particle diameter of titanium oxide ultrafine particles of 10 nm or less, preferably about 1 to 6 nm. When the average particle diameter of the titanium oxide ultrafine particles is larger than 10 nm, the film forming property is deteriorated (when the film is dried after coating to form a film, cracking occurs at a film thickness of 1 μm or more), which is not preferable. The appearance of this titanium oxide dispersion is translucent. Such a titanium oxide dispersion can also be used as the titanium-containing aqueous liquid (A).

The surface treatment composition (J) containing the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a is applied to the surface of the plated steel sheet and dried (for example, heat-dried at a low temperature), thereby adhering to itself. A dense titanium oxide-containing film (surface treatment film) having excellent properties can be formed.
The heating temperature after applying the surface treatment composition (J) is, for example, 200 ° C. or less, particularly preferably 150 ° C. or less. By heating and drying at such a temperature, an amorphous material containing some hydroxyl groups (amorphous) A titanium oxide-containing film can be formed.
In addition, when the titanium oxide dispersion obtained through the heat treatment or autoclave treatment as described above at 80 ° C. or more is used as the titanium-containing aqueous liquid (A), the surface treatment composition (J) is simply applied. It is useful as a coating material for materials that cannot be heat-treated.

Further, as the titanium-containing aqueous liquid (A), a titanium-containing aqueous liquid (A1) obtained by reacting the hydrolyzable titanium compound a with hydrogen peroxide in the presence of a titanium oxide sol can also be used. .
The titanium oxide sol is a sol in which amorphous titania fine particles and / or anatase type titania fine particles are dispersed in water (for example, an aqueous organic solvent such as an alcohol or alcohol ether may be added if necessary). As this titanium oxide sol, conventionally known ones can be used. For example, (i) a titanium oxide aggregate obtained by hydrolyzing a titanium-containing solution such as titanium sulfate or titanyl sulfate, (ii) titanium alkoxide, etc. Titanium oxide aggregates obtained by hydrolyzing organic titanium compounds of the above, (iii) Titanium oxide aggregates obtained by hydrolyzing or neutralizing titanium halide solutions such as titanium tetrachloride, etc. An amorphous titania sol dispersed in water, or a sol in which the titanium oxide aggregates are calcined to form anatase-type titanium fine particles and this is dispersed in water can be used.

In the firing of the amorphous titania, the amorphous titania can be converted into anatase titania by firing at a temperature of at least the crystallization temperature of anatase, for example, a temperature of 400 ° C. to 500 ° C. or more. Examples of the aqueous sol of titanium oxide include, for example, TKS-201 (trade name, manufactured by TEIKA CORPORATION, anatase crystal form, average particle diameter 6 nm), TA-15 (trade name, manufactured by NISSAN CHEMICAL CO., LTD., Anatase crystal form). STS-11 (trade name, manufactured by Ishihara Sangyo Co., Ltd., anatase type crystal form) and the like.
In the titanium-containing aqueous liquid (A1), the mass ratio x / y between the titanium oxide sol x and the titanium hydrogen peroxide reactant y (reaction product of the hydrolyzable titanium compound a and hydrogen peroxide solution) is 1 / A range of 99 to 99/1, preferably about 10/90 to 90/10 is suitable. If the mass ratio x / y is less than 1/99, the effect of adding the titanium oxide sol cannot be sufficiently obtained in terms of stability, photoreactivity, etc. On the other hand, if it exceeds 99/1, the film forming property is inferior. Absent.

The titanium-containing aqueous liquid (A1) can be obtained by reacting the hydrolyzable titanium compound a with hydrogen peroxide at a reaction temperature of 1 to 70 ° C. for about 10 minutes to 20 hours in the presence of a titanium oxide sol.
The production form and characteristics of the titanium-containing aqueous liquid (A1) are the same as those of the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a described above, but in particular, by using a titanium oxide sol. , It is possible to suppress a partial condensation reaction during the synthesis to increase the viscosity. The reason is considered to be that the condensation reaction product is adsorbed on the surface of the titanium oxide sol, and polymerization in a solution state is suppressed.

  In addition, when the titanium-containing aqueous liquid (A1) is heated or autoclaved at 80 ° C. or higher, a titanium oxide dispersion containing ultrafine particles of crystallized titanium oxide is obtained. The titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a described above also describes the temperature conditions for obtaining this titanium oxide dispersion, the particle diameter of the crystallized titanium oxide ultrafine particles, the appearance of the dispersion, etc. It is the same. Such a titanium oxide dispersion can also be used as the titanium-containing aqueous liquid (A1).

Like the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a described above, the surface treatment composition (J) containing the titanium-containing aqueous liquid (A1) is applied to the surface of the plated steel sheet and dried (for example, By heating and drying at a low temperature, it is possible to form a dense titanium oxide-containing film (surface-treated film) having excellent adhesion by itself.
The heating temperature after applying the surface treatment composition (J) is, for example, 200 ° C. or less, particularly preferably 150 ° C. or less. By heating and drying at such a temperature, anatase-type titanium oxide containing some hydroxyl groups is contained. A film can be formed.
As described above, of the titanium-containing aqueous liquid (A), the titanium-containing aqueous liquid (A) and the titanium-containing aqueous liquid (A1) using the hydrolyzable titanium compound a are excellent in storage stability, corrosion resistance, and the like. It is particularly preferable to use these in the present invention.

The compounding ratio of hydrogen peroxide water to at least one titanium compound selected from hydrolyzable titanium compounds, hydrolyzable titanium compound low condensates, titanium hydroxide, titanium hydroxide low condensates is titanium compounds It is preferably 0.1 to 100 parts by mass, preferably 1 to 20 parts by mass in terms of hydrogen peroxide with respect to 10 parts by mass. If the blending ratio of the hydrogen peroxide solution is less than 0.1 parts by mass in terms of hydrogen peroxide, chelate formation is not sufficient and white turbid precipitation occurs. On the other hand, if it exceeds 100 parts by mass, unreacted hydrogen peroxide tends to remain, and dangerous active oxygen is released during storage, which is not preferable.
The hydrogen peroxide concentration of the hydrogen peroxide solution is not particularly limited, but it is preferably about 3 to 30% by mass from the viewpoint of ease of handling and the solid content of the product liquid related to coating workability.

Other sols and pigments can be added and dispersed in the titanium-containing aqueous liquid (A) as necessary. Examples of the additive include commercially available titanium oxide sol, titanium oxide powder, mica, talc, barita, clay, and the like, and one or more of these can be added.
The content of the titanium-containing aqueous liquid (A) in the surface treatment composition (J) is 1 to 100 g / L, preferably 5 to 50 g / L in terms of solid content. It is preferable from the point.

  In the surface treatment composition (J) used in the present invention, a nickel compound (B), an aluminum compound (C), a fluorine-containing compound (D), and silicon oxide (E) are added in combination to the titanium-containing aqueous liquid (A). By doing so, the following effects can be obtained. That is, when the fluorine-containing compound (D) is added to the titanium-containing aqueous liquid (A), corrosion resistance and storage stability are improved, but blackening resistance is deteriorated. On the other hand, when the nickel compound (B) is added, the blackening resistance is improved, but the corrosion resistance is deteriorated. Therefore, the deterioration of the corrosion resistance is suppressed by adding the aluminum compound (C). Further, by adding silicon oxide (E), the adhesion of the organic resin layer formed as an upper layer, particularly a thick organic resin layer having a thickness of 100 μm or more, at the time of deformation of the steel sheet is improved. Therefore, by adding a nickel compound (B), an aluminum compound (C), a fluorine-containing compound (D) and silicon oxide (E) to the titanium-containing aqueous liquid (A) in combination, corrosion resistance, storage stability, It is considered that all of the black modification and the adhesion with the organic resin layer are improved.

The nickel compound (B) is blended for improving blackening resistance. Examples of the nickel compound (B) include nickel acetate, nickel nitrate, nickel sulfate, and the like, one or two of these. More than seeds can be used. Of these, nickel acetate is preferred from the viewpoint of improving blackening resistance.
The compounding quantity of a nickel compound (B) shall be 0.01-10 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous liquid (A), Preferably it is 0.1-2 mass parts. When the blending amount of the nickel compound (B) is less than 0.01 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), the blackening resistance is not sufficiently improved. Deteriorates.

The aluminum compound (C) is blended for improving corrosion resistance. Examples of the aluminum compound (C) include aluminum nitrate, aluminum acetate, aluminum sulfate, aluminum oxide, aluminum acetylacetonate, and aluminate. And one or more of these can be used. Among these, aluminum nitrate is preferable because it has good water solubility and improves corrosion resistance.
The compounding quantity of an aluminum compound (C) shall be 1-100 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous liquid (A), Preferably you may be 5-30 mass parts. If the compounding amount of the aluminum compound (C) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A) is less than 1 part by mass, the corrosion resistance is not sufficiently improved, whereas if it exceeds 100 parts by mass, the blackening resistance deteriorates. To do.
In the present invention, the blending ratio B / C of the nickel compound (B) and the aluminum compound (C) is particularly 1/1 to 1/100 in terms of the solid content, preferably from the viewpoint of both blackening resistance and corrosion resistance. It is desirable to set to 1/5 to 1/50.

The fluorine-containing compound (D) is blended in order to improve storage stability, corrosion resistance, water resistance, and the like. Examples of the fluorine-containing compound (D) include zircon ammonium fluoride and zircon potassium fluoride. Zircon hydrofluoric acid, titanium ammonium fluoride, hydrofluoric acid, ammonium hydrofluoride, etc., and one or more of these can be used. Of these, it is preferable to use at least one selected from ammonium zircon fluoride and zircon hydrofluoric acid. Zirconium hydrofluoric acid is particularly suitable from the viewpoint of corrosion resistance after alkaline degreasing and adhesion to water, and zircon hydrofluoric acid from the viewpoint of corrosion resistance after alkaline degreasing.
The compounding amount of the fluorine-containing compound (D) is 1 to 800 parts by mass, preferably 50 to 500 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). When the blending amount of the fluorine-containing compound (D) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A) is less than 1 part by mass, the improvement in storage stability, corrosion resistance, water resistance adhesion, etc. is not sufficient. When the amount exceeds mass parts, the blackening resistance deteriorates.

The silicon oxide (E) is blended in order to improve adhesion to an organic resin layer formed as an upper layer, particularly a thick organic resin layer having a thickness of 100 μm or more. ) Includes, for example, amorphous silica such as liquid phase silica and gas phase silica, and one or more of these can be used. Of these, particulate liquid phase silica (colloidal silica) and gas phase silica (fumed silica) are preferred from the viewpoint of adhesion to the organic resin layer. Examples of colloidal silica include Snowtex O, N, 20, 30, 40, C, and S manufactured by Nissan Chemical Industries, Ltd. As fumed silica, AEROSIL manufactured by Nippon Aerosil Co., Ltd.
130, 200, 200V, 200CF, 300, 300CF etc. are mentioned.
The reason why the adhesion with the organic resin layer is improved by blending silicon oxide (E) is that the surface polarity of the surface treatment film changes due to the blending of silicon oxide, which acts advantageously on the adhesion, or It is considered that the surface unevenness on the order of submicron expressed by the aggregation of silicon oxide is due to the increase in the effective bonding area with the adhesive.

  The compounding quantity of a silicon oxide (E) is 20-90 mass% by the ratio in the total solid of a surface treatment composition, Preferably you may be 30-60 mass%. When the amount of silicon oxide (E) in the total solid content of the surface treatment composition is less than 20 mass%, the adhesion with the organic resin layer is not sufficiently improved. On the other hand, when the amount exceeds 90 mass%, the organic resin layer After coating, the adhesion with the organic resin layer after the steel plate deformation such as bending is deteriorated. Further, when the organic resin layer is coated and then exposed to a corrosive environment such as a salt spray environment or a moist environment, corrosion from the end face or the scratched portion tends to occur. Furthermore, if silicon oxide (E) is added in an excessive amount, the binder effect due to other components of the surface treatment composition will be insufficient, so that the surface treatment film will be brittlely broken at the time of deformation, and adhesion between the organic resin layer and the plating layer will occur. It becomes impossible to maintain sex. Moreover, when silicon oxide (E) is compounded excessively, the barrier property of the surface treatment film is impaired, the permeation of corrosion factors in a corrosive environment cannot be suppressed, and the plating layer is easily corroded.

The surface treatment composition (J) used in the present invention essentially comprises the titanium-containing aqueous liquid (A) and components (B) to (E) as described above. One or more of phosphoric acid compound (F), vanadic acid compound (G), zirconium carbonate compound (H), water-soluble organic resin and / or water-dispersible organic resin (I) can be contained.
Examples of the organic phosphoric acid compound (F) 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 hydroxyl group-containing organic phosphorous acid; carboxyl group-containing organic phosphorous acid such as 2-hydroxyphosphonoacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and salts thereof. These 1 type (s) or 2 or more types can be used.

The organic phosphoric acid compound (F) has an effect of improving the storage stability of the titanium-containing aqueous liquid (A). Among them, 1-hydroxyethane-1, 1-diphosphonic acid has a particularly large effect. These are particularly preferably used.
The blending amount of the organic phosphoric acid compound (F) is 1 to 400 parts by weight, particularly 20 to 300 parts by weight with respect to 100 parts by weight of the solid content of the titanium-containing aqueous liquid (A). To preferred. When the compounding amount of the organic phosphoric acid compound (F) exceeds 400 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), the water-resistant adhesion is inferior.

Examples of the vanadate compound (G) include lithium metavanadate, potassium metavanadate, sodium metavanadate, ammonium metavanadate, and anhydrous vanadate, and one or more of these can be used. Of these, ammonium metavanadate is preferable from the viewpoint of water adhesion resistance.
The amount of the vanadic acid compound (G) is 1 to 400 parts by mass, particularly 10 to 400 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). It is preferable from the viewpoint of later corrosion resistance. When the compounding amount of the vanadic acid compound (G) exceeds 400 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), the corrosion resistance after alkali degreasing is inferior.

Examples of the zirconium carbonate compound (H) include salts of zirconium carbonate such as sodium, potassium, lithium, and ammonium, and one or more of these can be used. Of these, ammonium zirconium carbonate is preferable from the viewpoint of water-resistant adhesion.
The blending amount of the zirconium carbonate compound (H) is 1 to 400 parts by mass, particularly 10 to 400 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). It is preferable from the viewpoint of later corrosion resistance. When the compounding amount of the zirconium carbonate compound (H) exceeds 400 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), the corrosion resistance after alkali degreasing is inferior.

  The water-soluble organic resin and / or water-dispersible organic resin (I) is an organic resin that can be dissolved or dispersed in water, and a conventionally known method for water-solubilizing or dispersing the organic resin in water is known. The method can be applied. Specifically, the organic resin contains a functional group (for example, a hydroxyl group, a polyoxyalkylene group, a carboxyl group, an amino (imino) group, a sulfide group, a phosphine group, etc.) that can be water-soluble or water-dispersed independently. , And if necessary, part or all of these functional groups are amine compounds such as ethanolamine and triethylamine if acidic resin (carboxyl group-containing resin, etc.); ammonia water; lithium hydroxide, sodium hydroxide, water Neutralized with alkali metal hydroxides such as potassium oxide, and basic resins (amino group-containing resins, etc.), fatty acids such as acetic acid and lactic acid; neutralized with mineral acids such as phosphoric acid, etc. Can be used.

Examples of water-soluble or water-dispersible organic resins include epoxy resins, phenolic resins, acrylic resins, urethane resins, olefin-carboxylic acid resins, nylon resins, resins having a polyoxyalkylene chain, and polyvinyl alcohol. , Polyglycerin, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose and the like. The said organic resin can use 1 type (s) or 2 or more types.
Among these, the use of at least one organic resin selected from water-soluble or water-dispersible acrylic resins, urethane resins, and epoxy resins from the viewpoint of storage stability of the surface treatment composition. In particular, it is preferable to use a water-soluble or water-dispersible acrylic resin as a main component from the viewpoint of the balance between the storage stability of the surface treatment composition and the coating film performance.

A water-soluble or water-dispersible acrylic resin is prepared by a conventionally known method, for example, an emulsion polymerization method, a suspension polymerization method, a polymer having a hydrophilic group by solution polymerization, and neutralized or made aqueous if necessary. Or the like.
The polymer having a hydrophilic group includes, for example, an unsaturated monomer having a hydrophilic group such as a carboxyl group, an amino group, a hydroxyl group, and a polyoxyalkylene group, and, if necessary, other unsaturated monomers. It can be obtained by polymerizing the monomer.
The water-soluble or water-dispersible acrylic resin is preferably one obtained by copolymerizing styrene from the viewpoint of corrosion resistance, and the amount of styrene in the total unsaturated monomer is 10 to 60% by mass, particularly 15 to 50% by mass. It is preferable that Moreover, it is preferable from points, such as toughness of the film obtained, that Tg (glass transition point) of the acrylic resin obtained by copolymerization is 30-80 degreeC, especially 40-70 degreeC.

Examples of the carboxyl group-containing unsaturated monomer include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, crotonic acid, and itaconic acid.
Examples of the nitrogen-containing unsaturated monomer such as the amino group-containing unsaturated monomer include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, Nt- Nitrogen-containing alkyl (meth) acrylates such as butylaminoethyl (meth) acrylate; acrylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl Polymerization of (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, etc. Amides; 2-vinylpyridine, - vinyl-2-pyrrolidone, aromatic nitrogen-containing monomers such as 4-vinylpyridine; and allylamine and the like.

  Examples of the hydroxyl group-containing unsaturated monomer include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono Monoesterified product of polyhydric alcohol such as (meth) acrylate, polypropylene glycol mono (meth) acrylate and acrylic acid or methacrylic acid; ε-caprolactone is opened to monoesterified product of polyhydric alcohol and acrylic acid or methacrylic acid. Examples include a ring-polymerized compound.

Other unsaturated monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 1 carbon number such as tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, octadecyl (meth) acrylate, isostearyl (meth) acrylate -24 alkyl (meth) acrylates; vinyl acetate and the like.
The unsaturated monomer mentioned above can use 1 type (s) or 2 or more types. In the description of the present application, “(meth) acrylate” means “acrylate or methacrylate”.

  Examples of the urethane-based resin include a chain extender which is a low molecular weight compound having two or more active hydrogens such as a diol and a diamine as needed, and a polyurethane composed of a polyol and a diisocyanate such as a polyester polyol and a polyether polyol. Those which are chain-extended in the presence and stably dispersed or dissolved in water can be suitably used, and conventionally known ones can be widely used (for example, Japanese Patent Publication No. 42-24192, Japanese Patent Publication No. 42-24194, (See JP-B-42-5118, JP-B-49-986, JP-B-49-33104, JP-B-50-15027, JP-B-53-29175).

As a method for stably dispersing or dissolving the polyurethane resin in water, for example, the following method can be used.
(1) A method of imparting hydrophilicity by introducing an ionic group such as a hydroxyl group, an amino group or a carboxyl group into the side chain or terminal of a polyurethane polymer, and dispersing or dissolving in water by self-emulsification.
(2) A polyurethane polymer that has been completely reacted or a polyurethane polymer in which a terminal isocyanate group is blocked with a blocking agent such as oxime, alcohol, phenol, mercaptan, amine, or sodium bisulfite is forcibly submerged in water using an emulsifier and mechanical shearing force. How to disperse. Further, a method in which a urethane polymer having a terminal isocyanate group is mixed with water, an emulsifier, and a chain extender, and dispersion and high molecular weight are simultaneously performed using mechanical shearing force.
(3) A method in which a water-soluble polyol such as polyethylene glycol is used as a polyol as a main polyurethane material, and is dispersed or dissolved in water as a water-soluble polyurethane.
In addition, what was obtained by the different method among the dispersion | distribution or melt | dissolution methods mentioned above can also mix and use a polyurethane-type resin.

Examples of the diisocyanate that can be used for the synthesis of the polyurethane resin include aromatic, alicyclic or aliphatic diisocyanates. Specifically, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3′-dimethoxy-4, 4'-biphenylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 1,3- (diisocyanatomethyl) cyclohexanone, 1,4- (diisocyanatomethyl) cyclohexanone, 4,4'-diisocyanato Cyclohexanone, 4,4'-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane di Isocyanate, m- phenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-biphenylene diisocyanate and the like. Among these, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferable.
Examples of commercially available polyurethane resins include Hydran HW-330, HW-340, HW-350 (both trade names, manufactured by Dainippon Ink and Chemicals), Superflex 100, 150, E-2500, F-3438D (all are trade names, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

  As the epoxy resin, a cationic epoxy resin obtained by adding an amine to an epoxy resin; a modified epoxy resin such as an acrylic modification or a urethane modification can be preferably used. Examples of cationic epoxy resins include adducts of epoxy compounds and primary mono- or polyamines, secondary mono- or polyamines, and primary and secondary mixed polyamines (see, for example, US Pat. No. 3,984,299). An adduct of an epoxy compound and a secondary mono- or polyamine having a ketiminated primary amino group (see, for example, US Pat. No. 4,017,438); an epoxy compound and a ketiminated primary amino group Examples include etherification reaction products with hydroxyl compounds (see, for example, JP-A-59-43013).

  As the epoxy resin, those having a number average molecular weight of 400 to 4000, particularly 800 to 2000, and an epoxy equivalent of 190 to 2000, particularly 400 to 1000 are preferable. Such an epoxy resin can be obtained, for example, by a reaction between a polyphenol compound and epirulhydrin, and examples of the polyphenol compound include bis (4-hydroxyphenyl) -2,2-propane, 4,4. -Dihydroxybenzophenone, bis (4-hydroxyphenyl) -1,1-ethane, bis (4-hydroxyphenyl) -1,1-isobutane, bis (4-hydroxy-tert-butylphenyl) -2,2-propane, Bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, bis (2,4-dihydroxyphenyl) methane, tetra (4-hydroxyphenyl) -1,1,2,2-ethane, 4,4-dihydroxy Diphenylsulfone, phenol novolak, cresol novolak, etc. That.

The blending amount of the water-soluble organic resin and / or water-dispersible organic resin (I) is 80 parts by mass or less, particularly 5 to 50 parts by mass with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). Is preferable from the viewpoint of the uniformity of the resulting film. When the amount of the water-soluble organic resin and / or water-dispersible organic resin (I) exceeds 80 parts by mass, the heat discoloration tends to be lowered.
In the surface treatment composition (J), if necessary, for example, etching agents such as silane coupling agents, resin fine particles, inorganic phosphate compounds, heavy metal compounds other than the components defined by the present invention, thickeners, A surfactant, a lubricity-imparting agent (polyethylene wax, fluorine-based wax, carnauba wax, etc.), a rust inhibitor, a color pigment, an extender pigment, a rust preventive pigment, and a dye can be contained. In particular, in order to improve the adhesion with the organic resin layer, it is preferable to contain a silane coupling agent.

  Moreover, in order to mix | blend silicon oxide (E) with a surface treatment composition (J), in the case of liquid phase silica (colloidal silica), what is necessary is just to adjust and mix a compounding quantity with another compounding component. In addition, in the case of vapor phase silica (fumed silica), before mixing with other compounding ingredients, a water-dispersed silicon oxide dispersion is prepared in advance by vigorous stirring in water and mixed with the other ingredients. do it. Alternatively, the surface treatment composition may be prepared by vigorously stirring vapor phase silica together with other compounding components and water.

Further, the surface treatment composition (J) can be used by diluting with a hydrophilic solvent such as methanol, ethanol, isopropyl alcohol, ethylene glycol solvent, propylene glycol solvent, if necessary.
The adhesion amount of the surface treatment film formed by the surface treatment composition (J) is 0.1 to 2.0 g / m ² , preferably 0.2 to 1.5 g / m ² . When the coating amount is less than 0.1 g / m ² , the corrosion resistance is inferior. On the other hand, when it exceeds 2.0 g / m ² , the coating is liable to break and the corrosion resistance and adhesion are deteriorated. Further, a more preferable adhesion amount is 0.2 to 0.6 g / m ² , and particularly preferable is 0.2 to 0.4 g / m ² .

In order to produce the surface-treated steel sheet of the present invention, the titanium-containing aqueous liquid (A), nickel compound (B), and aluminum compound (C) as described above are formed on the surface of the zinc-based plated steel sheet or the aluminum-based plated steel sheet. , A fluorine-containing compound (D) and silicon oxide (E) as main components, and if necessary, an organic phosphate compound (F), a vanadate compound (G), a zirconium carbonate compound (H), a water-soluble organic compound After apply | coating the surface treatment composition (J) (treatment liquid) containing 1 or more types of resin or / and water-dispersible organic resin (I), it dries without washing with water.
In addition, the titanium-containing aqueous liquid (A) and the surface treatment composition (J) may further contain other additive components as mentioned above, if necessary.

The means for applying the surface treatment composition (treatment liquid) is optional, for example, spray + roll squeezing, roll coater, etc. Also, the drying method after application is also, for example, a hot air method, induction heating method, electric furnace method, etc. Is optional.
The drying temperature (steel plate temperature) of the applied surface treatment composition (treatment liquid) is preferably about 60 to 200 ° C. When the drying temperature is less than 60 ° C., the film formation is insufficient and the film has poor corrosion resistance. On the other hand, even if it is dried at a plate temperature exceeding 200 ° C., the effect of improving the corrosion resistance commensurate with the drying temperature cannot be obtained, and the corrosion resistance may be lowered. This is presumably because cracks occur in the film due to heat. Moreover, a more preferable drying temperature is 60-140 degreeC, Furthermore, 60-90 degreeC is more preferable.

The organic resin-coated steel sheet of the present invention is obtained by forming an organic resin layer on the surface-treated film of the surface-treated steel sheet as described above. The method for forming the organic resin layer is arbitrary, and for example, a method of applying and drying a coating composition, a method of laminating an organic resin film, and the like can be applied.
Moreover, since the surface treatment film of the present invention is particularly excellent in adhesion of a thick organic resin layer having a thickness of 100 μm or more, the organic resin-coated steel sheet of the present invention has an organic resin layer thickness of 100 μm or more. Is particularly useful.
The organic resin layer may contain various additives including non-chromium rust preventive additives, solid lubricants, color pigments and the like.

The titanium-containing aqueous liquid (A) and components (B) to (I) used in the surface treatment composition are shown below.
[Production of titanium-containing aqueous liquid (A)]
Production Example 1 (Titanium-containing aqueous liquid T1)
Ammonia water (1: 9) was added dropwise to a solution in which 5 cc of a titanium tetrachloride 60 mass% solution was made 500 cc with distilled water to precipitate titanium hydroxide. After washing with distilled water, 10 cc of a 30% by mass hydrogen peroxide solution was added and stirred to obtain a yellow translucent viscous titanium-containing aqueous liquid T1 containing titanium.
Production Example 2 (Titanium-containing aqueous liquid T2)
A mixture of 10 parts by mass of tetraiso-propoxytitanium and 10 parts by mass of iso-propanol was dropped into a mixture of 30 parts by mass of 10 parts by mass of hydrogen peroxide and 100 parts by mass of deionized water with stirring at 20 ° C. over 1 hour. did. Thereafter, aging was carried out at 25 ° C. for 2 hours to obtain a yellow transparent, slightly viscous titanium-containing aqueous liquid T2.
Production Example 3 (Titanium-containing aqueous liquid T3)
A titanium-containing aqueous liquid T3 was obtained under the same production conditions as in Production Example 2 except that tetra-n-butoxy titanium was used instead of tetraiso-propoxy titanium used in Production Example 2.

Production Example 4 (Titanium-containing aqueous liquid T4)
A titanium-containing aqueous liquid T4 was obtained under the same production conditions as in Production Example 2 except that tetramer of tetraiso-propoxytitanium used in Production Example 2 was used instead of tetraiso-propoxytitanium.
Production Example 5 (Titanium-containing aqueous liquid T5)
A titanium-containing aqueous liquid was produced under the same production conditions as in Production Example 2, except that hydrogen peroxide was used in 3 times the amount of Production Example 2, dropped at 50 ° C over 1 hour, and further aged at 60 ° C for 3 hours. T5 was obtained.
Production Example 6 (Titanium-containing aqueous liquid T6)
The titanium-containing aqueous liquid T3 produced in Production Example 3 was further heat-treated at 95 ° C. for 6 hours to obtain a white yellow translucent titanium-containing aqueous liquid T6.
Production Example 7 (Titanium-containing aqueous liquid T7)
A mixture of 10 parts by mass of tetraiso-propoxytitanium and 10 parts by mass of iso-propanol, 5 parts by mass (solid content) of “TKS-203” (trade name, manufactured by Teika Co., Ltd.), 30% by mass hydrogen peroxide solution The mixture was added dropwise to a mixture of 10 parts by mass and 100 parts by mass of deionized water with stirring at 10 ° C. over 1 hour. Thereafter, the mixture was aged at 10 ° C. for 24 hours to obtain a yellow transparent, slightly viscous titanium-containing aqueous liquid T7.

[Nickel compound (B)]
B1: Nickel acetate B2: Nickel nitrate B3: Nickel sulfate [Aluminum compound (C)]
C1: Aluminum nitrate C2: Aluminum acetate C3: Aluminum acetylacetonate [fluorine-containing compound (D)]
D1: Zircon ammonium fluoride D2: Zircon hydrofluoric acid D3: Zircon sodium fluoride D4: Zircon fluoride [silicon oxide (E)]
E1: Aerosil 300 (trade name, manufactured by Nippon Aerosil Co., Ltd., fumed silica)
E2: Aerosil 200 (trade name, manufactured by Nippon Aerosil Co., Ltd., fumed silica)

[Organic Phosphate Compound (F)]
F1: 1-hydroxymethane-1,1-diphosphonic acid F2: 1-hydroxyethane-1,1-diphosphonic acid [vanadic acid compound (G)]
G1: ammonium metavanadate G2: sodium metavanadate [zirconium carbonate compound (H)]
H1: Ammonium zirconium carbonate H2: Sodium zirconium carbonate [Water-soluble or water-dispersible organic resin (I)]
I1: Superflex E-2500 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., water-based polyurethane resin)
I2: Bayronal MD-1100 (trade name, manufactured by Toyobo Co., Ltd., water-based polyester resin)
I3: Adeka Resin EM-0718 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd., aqueous epoxy resin)

As the base steel plate of the surface-treated steel plate, the plated steel plate shown in Table 1 was used.
A surface treatment composition in which components (B) to (I) are appropriately blended and mixed with the above-described titanium-containing product liquid (A) is applied to the surface of the plated steel sheet, and after 5 seconds, a predetermined drying temperature (maximum reached plate) is applied. It was dried to obtain a test material. Comparative Example 8 is a test material that was subjected to phosphate treatment. In this comparative example, as a pretreatment for the phosphate treatment, the surface of the zinc-based plated steel sheet was surface-treated with a surface conditioner (trade name “Plenpalen Z”, manufactured by Nihon Parkerizing Co., Ltd.), and then the zinc phosphate treatment A solution (trade name “PB3312M”, manufactured by Nihon Parkerizing Co., Ltd.) was used to perform phosphate treatment so that the amount of adhesion was 1.0 g / m ² .

These test materials were evaluated for heat discoloration resistance, corrosion resistance and blackening resistance by the following test methods (1) to (3).
Furthermore, after applying a common adhesive for polyvinyl chloride film to the test material so that the dry film thickness becomes 3 μm, the furnace temperature is heated in a heating furnace having a temperature of 100 ° C., and then a polyvinyl chloride film having a film thickness of 250 μm is formed. The polyvinyl chloride film (organic resin layer) was adhered by thermocompression bonding with the roll pressed against the surface of the test material so that the steel sheet temperature was 230 ° C. Thus, about the test material which formed the organic resin layer, adhesiveness, the adhesiveness after immersion in boiling water, and corrosion resistance were evaluated by the test method of following (4)-(6).
The above results are shown in Tables 2 to 9 together with the composition of the surface treatment composition applied to each specimen and the coating conditions. In Table 2, Table 4, Table 6, and Table 8, the blending amounts of components (A) to (D) and (F) to (I) are solids in 1 liter of the surface treatment composition (aqueous treatment liquid). It is the partial mass (g), and the blending amount of the component (E) is the total ratio (mass%) in the total solid content of the surface treatment composition (aqueous treatment liquid).

(1) Heat-resistant discoloration The specimen was heated to a plate temperature of 500 ° C. in an infrared image furnace in 30 seconds, held for 30 seconds, and then visually observed on the surface appearance when allowed to cool naturally to room temperature. The evaluation criteria are as follows.
○: No discoloration △: Discoloration to pale yellow ×: Discoloration from yellow to brown (2) Corrosion resistance JIS-Z-2371-2000 salt spray test was performed on the specimen with the end and back side tape-sealed. The test time when the rust generation area ratio was 5% was measured. The evaluation criteria are as follows.
○: 24 hours or more Δ: 12 hours or more, less than 24 hours ×: less than 12 hours

(3) Blackening resistance The change in whiteness (L value) when the test material was allowed to stand for 24 hours in a thermo-hygrostat controlled at a temperature of 80 ° C. and a relative humidity of 95% RH was expressed as ΔL (L before test) Value-L value after test). The evaluation criteria are as follows.
○: ΔL ≧ −5.0
Δ: −5.0> ΔL ≧ −10.0
×: −10.0> ΔL
(4) Adhesion In accordance with the adhesion test (Eriksen test) described in JIS-K-6744-1992 (polyvinyl chloride-coated metal plate), a test piece of 90 mm × 90 mm cut out from the test material was used. Thus, the adhesion of the organic resin layer was examined. In this adhesion test, after pushing in with an Erichsen height of 6 mm and a cut portion length of 50 mm, the state of peeling of the organic resin layer was visually observed and evaluated according to the following criteria.
◎: No peeling ○: Part of the cut edge is slightly peeled (within 1 mm from the cut)
X: The film is largely peeled at the edge of the cut part (exceeding 1 mm from the cut)

(5) Adhesion after immersion in boiling water Except that the test piece was immersed in boiling ion exchange water for 1 hour before the adhesion test, the same method as in “(4) Adhesion” above. An adhesion test was conducted and evaluated according to the following criteria.
◎: No peeling ○: Part of the cut edge is slightly peeled (within 1 mm from the cut)
X: The film is largely peeled at the edge of the cut part (exceeding 1 mm from the cut)
(6) Corrosion resistance (after coating with organic resin layer)
It is a method according to the description of the corrosion resistance section of JIS-K-6744-1992, using a test piece of 50 mm × 100 mm cut out from the test material, and in accordance with the provisions of JIS-Z-2371-2000 The spray test was conducted for 500 hours. In this test, a part of the end face of each test piece was exposed, and evaluation was performed according to the following criteria according to the degree of swelling of the organic resin layer from the edge.
◎: Swelling width from edge (maximum value) less than 10 mm ○: Swelling width from edge (maximum value) 10 mm or more and less than 20 mm △: Swelling width from edge (maximum value) 20 mm or more and less than 30 mm ×: From edge Swollen width (maximum value) 30 mm or more

In Table 2, Table 4, Table 6, and Table 8, * 1 to * 12 indicate the following contents.
* 1 Plated steel plates No. 1 to 9 listed in Table 1
* 2 Titanium-containing aqueous liquids T1 to T7 described in the specification text
* 3 Nickel compounds B1 to B3 described in the specification text
* 4 Aluminum compounds C1 to C3 described in the specification text
* 5 Fluorine-containing compounds D1 to D4 described in the main text of the specification
* 6 Silicon oxide E1, E2 as described in the text of the specification
* 7 Organophosphate compounds F1 and F2 in the description text
* 8 Vanadic acid compounds G1 and G2 described in the main text of the specification
* 9 Zirconium carbonate compounds H1 and H2 described in the specification text
* 10 Water-soluble or water-dispersible organic resins I1 to I3 described in the main text of the specification
* 11 Solid content in 1 liter of surface treatment composition (aqueous treatment liquid) (g)
* 12 Total ratio of the surface treatment composition (aqueous treatment liquid) in the total solid content (mass%)

Claims (7)

At least one titanium selected from a hydrolyzable titanium compound, a hydrolyzable titanium compound low-condensate, titanium hydroxide, and a titanium hydroxide low-condensate on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet The nickel compound (B) is 0.01 to 10 parts by mass and the aluminum compound (C) is 1 to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A) obtained by mixing the compound with hydrogen peroxide. Surface treatment composition containing ˜100 parts by mass, 1 to 800 parts by mass of fluorine-containing compound (D), and further containing 20 to 90 mass% of silicon oxide (E) in the total solid content of the surface treatment composition A surface-treated steel sheet having a surface-treated film having a film adhesion amount of 0.1 to 2.0 g / m ² formed by applying and drying the product (J).   The surface-treated steel sheet according to claim 1, wherein the fluorine-containing compound (D) is at least one selected from zircon ammonium fluoride and zircon hydrofluoric acid.   The surface treatment composition (J) further contains 1 to 400 parts by mass of the organic phosphate compound (F) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). Or the surface-treated steel plate of 2.   The surface treatment composition (J) further contains 1 to 400 parts by mass of the vanadic acid compound (G) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). The surface-treated steel sheet according to any one of 3 above.   The surface treatment composition (J) further contains 1 to 400 parts by mass of the zirconium carbonate compound (H) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). 4. The surface-treated steel sheet according to any one of 4 above.   The surface treatment composition (J) further contains 80 parts by mass or less of the water-soluble organic resin and / or the water-dispersible organic resin (I) with respect to 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A). The surface-treated steel sheet according to any one of claims 1 to 5.   An organic resin-coated steel sheet having an organic resin layer on the surface-treated film of the surface-treated steel sheet according to claim 1.