TWI473665B - Surface-treating composition and surface-treated steel sheet - Google Patents

Description

Surface treatment composition and surface treated steel sheet

The present invention relates to an environmentally-friendly surface treatment composition which is completely free of hexavalent chromium in a surface treatment composition and a surface-treated steel sheet which are suitable for use in automobiles, home appliances, building materials, and surface treatment using the same. Steel plate.

Steel sheets for home appliances, steel sheets for building materials, and steel sheets for automobiles are widely used on the surface of galvanized steel sheets or aluminized steel sheets. In order to improve corrosion resistance (white rust resistance and red rust resistance), the main component is chromium. A chromate-treated steel sheet is treated with a treatment liquid of acid, dichromic acid or a salt thereof. The chromate treatment is an economical treatment method which is excellent in corrosion resistance and can be easily carried out.

The chromate treatment is a method of using hexavalent chromium of a pollution-damping substance, but the hexavalent chromium is treated by a closed system in the treatment process, and the organic film formed by the upper layer can be hardly replaced by chromic acid by using a sealing effect. Since chromium is eluted from the salt film, substantially hexavalent chromium does not contaminate the human body and the environment. However, with the increasing interest in global environmental issues, attention has been paid not only to the previous operating environment and drainage treatment, but also to the regulation of environmental impacts and environmental adjustments. Moreover, the background of the times has changed to assessing the manufacturer with environmental contribution, so the motivation for reducing the use of heavy metals containing hexavalent chromium has increased.

In this context, white rust suppression technology (chromate-free technology) that does not use hexavalent chromium galvanized steel sheets has been proposed many times. For example, as disclosed in Patent Documents 1 and 2, a surface treatment agent containing aluminum and a phosphoric acid compound, ceria and a water-based organic resin emulsion, and a metal material coated therewith are contained. Further, in Patent Document 3, a galvanized steel sheet in which an organic coating layer is formed by applying a mixed aqueous solution of a polyvalent metal monophosphate and a metal oxide sol and drying to form an amorphous coating is proposed. Further, as disclosed 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, and an upper layer thereof is provided. A steel sheet forming an organic film.

In the use of a galvanized steel sheet, there is a member which is heated in a temperature range (500 to 600 ° C) which is higher than the melting point of zinc. For example, in the heat exchanger in the outdoor unit of the refrigerator, when the copper tube and the aluminum evaporator are waxed, in order to prevent the aluminum from being dissolved by the use of the spray gun, a galvanized steel sheet is disposed between the copper tube and the evaporator to avoid the spray gun. The flame is in direct contact with the aluminum. When the surface-treated steel sheet of the above prior art is used for this application, since the film main body is an organic resin, it is discolored to yellow or brownish brown by thermal decomposition, and the appearance is poor. It is therefore almost impossible to use the surface treated steel sheets of the prior art.

In order to solve such problems, a chromate-free technology having excellent heat discoloration resistance has been proposed. For example, as proposed in Patent Documents 6 and 7, the main component is an inorganic saturated film of magnesium diphosphate and colloidal cerium oxide and a phosphonic acid compound. Further, as proposed in Patent Document 8, the inorganic saturated film of the primary component phosphate and the colloidal ceria is used as the lower layer, and the upper layer is provided with the double coating of the niobate film and/or the tantalum resin. Further, Patent Document 9 discloses at least one titanium compound and hydrogen peroxide water selected from the group consisting of a hydrolyzable titanium compound, a low condensate of a hydrolyzable titanium compound, a titanium oxyhydroxide, and a low condensate of titanium hydroxide. A surface treatment composition of the obtained titanium-containing aqueous liquid and organic phosphoric acid, a water-soluble or water-dispersible organic resin, a vanaic acid compound, a zirconium fluoride compound, and a zirconium carbonate compound.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 11-350157

[Patent Document 2] JP-A-2000-26980

[Patent Document 3] JP-A-2000-129460

[Patent Document 4] JP-A-2002-53979

[Patent Document 5] JP-A-2002-53980

[Patent Document 6] JP-A-2000-79370

[Patent Document 7] JP-A-2001-348672

[Patent Document 8] JP-A-2004-91826

[Patent Document 9] JP-A-2006-9121

However, the inorganic saturated coatings of Patent Documents 6 and 7 have extremely low corrosion resistance, and are difficult to be applied as chromate coating substitutes. Further, although the double-layer film of Patent Document 8 has a corrosion resistance level suitable for use as a chromate film substitute, there is a cost problem due to the use of expensive tantalate and tantalum resin. Moreover, the film of these techniques is prone to discoloration to black in a wet environment (blackening), so that it is difficult to adapt to a heat exchanger that is easy to frost, and the storage environment during product transportation is also limited, and there is no practicality. Further, in the surface-treated composition of Patent Document 9, since the fluoride contained therein is a material which improves water-resistant adhesion and corrosion resistance after alkali degreasing, when the upper layer has a thick organic resin layer, the adhesion is lowered.

Further, in the organic resin-coated steel sheet such as a coated steel sheet or a laminated steel sheet, the adhesion of the organic resin layer is an important performance, but the film obtained by the phosphate treatment previously performed as a low-layer treatment is crystalline, so that it is severe. The processing destroys the crystal and easily reduces the adhesion of the organic resin layer. In particular, when the thickness of the organic resin layer is 100 μm or more of the coated steel sheet and the laminated steel sheet, the phosphate film is destroyed when the steel sheet is processed, and the organic resin layer is easily peeled off from the starting point.

In order to solve this problem, for example, in the above-mentioned Patent Documents 3 to 5, the plating metal on the substrate is reacted with the treatment liquid to form a poorly soluble phosphate of an extremely thin film to find corrosion resistance, paint adhesion, etc., but even The surface-treated steel sheet is used for an organic resin-coated steel sheet, and it is easy to reduce adhesion and corrosion resistance during processing. In particular, when the organic resin-coated steel sheet having an organic resin layer having a thickness of 100 μm or more has a high film strength, the organic resin layer is easily peeled off due to a strong shearing force at the interface between the organic resin layer and the bottom layer during deformation.

In view of the above-mentioned problems of the prior art, the present application has been proposed in Japanese Patent Application No. 2008-335387, which can provide excellent corrosion resistance, heat discoloration resistance and blackening resistance, and can be formed with an organic resin layer formed on the surface of the surface treatment film. Excellent surface adhesion is obtained, and in particular, when the steel sheet having an organic resin layer having a thickness of 100 μm or more is deformed, a surface-treating composition having excellent adhesion can be obtained. The surface treatment composition is a titanium compound containing at least one selected from the group consisting of a hydrolyzable titanium compound, a low condensate of a hydrolyzable titanium compound, a titanium hydroxide, and a low condensate of titanium hydroxide. An aqueous solution containing titanium obtained by mixing hydrogen peroxide with a zirconium carbonate compound, an organic phosphoric acid compound, a metal phosphate, and cerium oxide.

However, it has been found by the inventors of the present invention that the film formed by the surface treatment composition has a brittle nature. Therefore, when a surface-treated steel sheet is produced by a real machine, it is contained in a film formed after contact with a metal roller. Injury, it is easy to reduce the problem of corrosion resistance. Further, in a severe environment such as a high-temperature wet environment, there is a problem that the adhesion to the above-mentioned thick organic resin layer cannot be sufficiently ensured.

In order to solve the above problems, it is an object of the present invention to provide excellent corrosion resistance, heat discoloration resistance, and blackening resistance which are excellent in corrosion resistance, heat discoloration resistance, and blackening resistance, and excellent contact resistance when contacting a metal roller after forming a surface treatment film. And excellent adhesion to the organic resin layer formed on the surface of the surface treatment film, in particular, forming a thick organic resin layer having a thickness of 100 μm or more, and excellent adhesion even when subjected to excessive processing, Further, in a harsh environment as in a high-temperature wet environment, a surface-treated composition excellent in adhesion to the thick organic resin layer and a surface-treated steel sheet can be obtained.

Further, another object of the present invention is to provide an organic resin-coated steel sheet using the surface-treated steel sheet.

The inventors of the present invention have reviewed the composition of the film to solve the above-mentioned problems, and as a result, found that a surface of a metal material (preferably a galvanized steel sheet or an aluminum-plated steel sheet) is added with a specific ratio of carbonic acid to a specific titanium-containing aqueous liquid. When a surface treatment film is formed by a zirconium compound, an organic phosphoric acid compound, a metal phosphate, a cerium oxide, a water-soluble organic resin, and/or a water-dispersible organic resin, and a surface treatment composition of a decane coupling agent, excellent corrosion resistance and heat discoloration are obtained. And blackening resistance, scratch resistance when contacting a metal roll after forming a surface treatment film, and forming an organic resin layer on the upper layer of the surface treatment film, in particular, a thick organic resin layer having a thickness of 100 μm or more. Excellent adhesion can be obtained when the processing is performed severely, and excellent adhesion to the thick organic resin layer can be obtained even in a severe environment such as a high-temperature wet environment.

Based on this finding, the gist of the present invention is as follows.

[1] A surface treatment composition comprising at least one selected from the group consisting of a low condensate of a hydrolyzable titanium compound, a hydrolyzable titanium compound, a titanium hydroxide, and a titanium hydroxide. 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A) obtained by mixing the titanium compound with hydrogen peroxide water, 10 to 300 parts by mass of the zirconium carbonate compound (B), and 50 to 200 parts by mass of the organic phosphoric acid compound ( C), the metal phosphate (D) which is still contained in the total solid content of the surface treatment composition in a ratio of 2 to 20 mass%, and the ratio of the total solid content of the surface treatment composition is 20 to 40 mass% The cerium oxide is a water-soluble organic resin and/or a water-dispersible organic resin (F) in a ratio of 2 to 10 mass% in the total solid content of the surface treatment composition, and is in the total solid content of the surface-treated composition. A decane coupling agent (G) in a ratio of 0.5 to 20 mass%.

[2] The surface treatment composition according to [1] above, wherein the cerium oxide (E) is a gas phase cerium oxide produced by a dry method.

[3] The surface treatment composition according to [2] above, wherein the gas phase cerium oxide has a bulk specific gravity of 40 g/L or less.

[4] The surface treatment composition according to any one of the above [1] to [3] wherein the decane coupling agent (G) has a glycidyl group.

[5] The surface treatment composition according to any one of the above [1] to [4], which has a pH of from 7 to 12.

[6] A surface-treated steel sheet characterized by coating the surface-treated composition of any one of the above [1] to [5] on a surface of a galvanized steel sheet or an aluminum-plated steel sheet to be dried. The surface-treated film having a film adhesion amount formed thereafter is 0.03 to 0.5 g/m ² .

[7] An organic resin-coated steel sheet characterized in that the surface-treated coating of the surface-treated steel sheet according to the above [6] has an organic resin layer.

The surface treatment film formed by the surface treatment composition of the present invention has a high barrier property by being composed of a specific inorganic component, and thus has excellent corrosion resistance and blackening resistance comparable to a chromate film, and is not easily heated. Excellent color heat resistance and color change. Further, when the surface treatment film is formed, it is excellent in scratch resistance when it is contacted with a metal roll or the like, and an organic resin layer is formed on the upper layer of the surface treatment film, in particular, a thick organic resin layer having a thickness of 100 μm or more, even if it is too strict Excellent adhesion is also obtained during processing, and excellent adhesion to the thick organic resin layer can be obtained even in a severe environment such as a high-temperature wet environment.

Moreover, the surface-treated steel sheet and the organic resin-coated steel sheet of the present invention have excellent corrosion resistance, blackening resistance, heat discoloration resistance, and scratch resistance, and adhesion to the organic resin layer, particularly, thickness of 100 μm or more. The adhesiveness of the organic resin layer also has excellent adhesion in a harsh environment like a high-temperature wet environment.

[Best Mode for Carrying Out the Invention]

The surface treatment composition of the present invention comprises an aqueous liquid (A) containing titanium, a zirconium carbonate compound (B), an organic phosphoric acid compound (C), a metal phosphate (D), cerium oxide (E), and a water-soluble organic resin. And/or a water-dispersible organic resin (F) or a decane coupling agent (G). The surface treatment composition does not contain hexavalent chromium (except for the unclean 6-valent chromium).

The titanium-containing aqueous liquid (A) is a titanium compound selected from at least one selected from the group consisting of a hydrolyzable titanium compound, a low condensate of a hydrolyzable titanium compound, a titanium hydroxide, and a low condensate of titanium hydroxide. The aqueous solution containing titanium obtained by mixing hydrogen peroxide water.

The hydrolyzable titanium compound is a titanium compound having a hydrolyzable group directly bonded to titanium, and is formed by reacting with water such as water or steam to form titanium hydroxide. Further, the hydrolyzable titanium compound may be one in which all of the groups bonded to the titanium are hydrolyzable groups, or the group bonded to the base of titanium is a hydrolyzable group.

The hydrolyzable group may be one which is formed by reacting with water to form titanium hydroxide as described above, and is not particularly limited, for example, a lower alkoxy group or a salt forming a salt with titanium (for example, a halogen atom such as chlorine, a hydrogen atom, a sulfate ion, or the like). )Wait.

The hydrolyzable titanium compound having a hydrolyzable group which is a lower alkoxy group is particularly preferably represented by a general formula of Ti(OR) ₄ (wherein R is the same or a different alkyl group having 1 to 5 carbon atoms). Titanyl alkoxide. The alkyl group having 1 to 5 carbon atoms is, for example, 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, a tert-butyl group or the like.

The water-decomposable group contained is a hydrolyzable titanium compound which forms a salt with titanium, such as titanium chloride, titanium sulfate or the like.

Further, the low condensate of the hydrolyzable titanium compound is a low condensate of the hydrolyzable titanium compounds. The low condensate may be one in which all of the groups bonded to the titanium are hydrolyzable groups, or the group bonded to the base of titanium is a hydrolyzable group.

The hydrolyzable titanium compound (for example, titanium chloride, titanium sulfate, etc.) in which the hydrolyzable group is a salt with titanium, ortho-titanic acid obtained by reacting an aqueous solution of the hydrolyzable titanium compound with an alkali solution such as ammonia or caustic soda ( Titanium hydroxide gel) can also be used as a low condensate.

As the low condensate of the hydrolyzable titanium compound and the low condensate of the titanium hydroxide, a compound having a degree of condensation of 2 to 30 can be used, and a compound having a degree of condensation of 2 to 10 is particularly preferably used. When the degree of condensation is 30 or less, a stable aqueous solution containing titanium can be obtained by mixing with hydrogen peroxide.

The hydrolyzable titanium compound, the low condensate of the hydrolyzable titanium compound, the low condensate of the titanium hydroxide or the titanium hydroxide may be used alone or in combination of two or more kinds, and particularly preferably, the hydrolyzable property represented by the above general formula. Titanium compound titanium tetraalkoxide. The reason for this is that the alcohol formed by the tetraalkoxy titanium during the hydrolysis can be volatilized during the process of drying the surface-treated composition, so that the film properties such as corrosion resistance and the like are not affected, and in particular, excellent film properties can be obtained.

The aqueous liquid (A) containing titanium may be an aqueous liquid containing titanium obtained by mixing the above titanium compound and hydrogen peroxide water, and the prior art may be used without particular limitation. Specifically, for example, the following.

(i) a titanium oxyhydroxide hydroperoxide complex or a titanic acid (peroxide titanium hydrate) aqueous solution obtained by adding a hydrogen oxyhydroxide-containing gel or a sol with hydrogen peroxide water (refer to Japanese Laid-Open Patent Publication No. SHO63-35419, JP-A-1-224220).

(ii) a titanium dioxide film-forming liquid obtained by the action of hydrogen peroxide water in a titanium hydroxide gel produced from an aqueous solution of titanium chloride or titanium sulfate and an alkaline solution (refer to Japanese Laid-Open Patent Publication No. Hei 9-71418, No. Bulletin 10-67516).

When the liquid for forming titanium dioxide is produced, an aqueous solution of titanium chloride or titanium sulfate having a base forming a salt with titanium is reacted with an alkali solution such as ammonia or caustic soda to precipitate a titanium hydroxide gel called orthotitanic acid. . Next, the titanium hydroxide gel is separated by decantation using water, and after fully washing with water, hydrogen peroxide water is added to decompose and remove excess hydrogen peroxide to obtain a yellow transparent viscous liquid.

The ortho-titanic acid after precipitation is a gel state in which OH is polymerized or hydrogen-bonded to form a polymer, and it cannot be directly used as an aqueous solution containing titanium. The addition of hydrogen peroxide water to the gel causes the OH moiety to become a peroxidized state, or a sol state in which the peroxytitanate ion is dissolved or the polymer chain is interrupted to become a low molecule, and the excess hydrogen peroxide water is decomposed into water. Oxygen can be used as an aqueous solution containing titanium for forming an inorganic film.

Since the sol contains only an oxygen atom and a hydrogen atom in addition to the titanium atom, when it is changed to titanium oxide by drying or baking, only water and oxygen are generated, so that it is not necessary to remove the carbon necessary for thermal decomposition such as a sol-gel method or a sulfate. The composition and the halogen component can form a high-density titanium oxide film even at a low temperature.

(iii) adding hydrogen peroxide to the aqueous solution of the inorganic titanium compound of titanium chloride or titanium sulfate to form a titanium peroxide hydrate, adding a basic substance, and the resulting solution is placed to be heated to form a precipitate of the titanium perotate hydrate polymer. Then, a solution for forming a titanate which is obtained by the action of the hydrogen peroxide is removed from the solution of the titanium-containing raw material solution, and the solution for forming a titanate is obtained by the action of hydrogen peroxide (see JP-A-2000-247638, JP-A-2000-247639).

The titanium-containing aqueous liquid (A) which is a hydrolyzable titanium compound and/or its low condensate (hereinafter referred to as "hydrolyzable titanium compound a" for convenience of explanation) may be a hydrolyzable titanium compound a is obtained by reacting hydrogen peroxide with water at a reaction temperature of 1 to 70 ° C for 10 minutes to 20 hours.

The titanium-containing aqueous liquid (A) of the hydrolyzable titanium compound a is presumed to be a reaction of hydrolyzable titanium compound a with hydrogen peroxide water, and hydrolyzed hydrolyzable titanium compound a with water to form a titanium compound containing a hydroxyl group, followed by Hydrogen peroxide is located in the titanium compound containing a hydroxyl group, so that the hydrolysis reaction and the coordination of hydrogen peroxide are generated at the same time, so that the stability at room temperature is extremely high, and long-term storage can be formed. Chelating solution. The titanium hydroxide gel used in the previous method is partially ternary by a Ti-O-Ti bond, so the composition and stability are substantially different from those of the titanium containing the reaction of the gel with hydrogen peroxide. Aqueous liquid (A).

In addition, when the aqueous solution (A) containing titanium of the hydrolyzable titanium compound a is used for heat treatment at 80 ° C or higher or autoclave treatment, a titanium oxide dispersion liquid containing ultrafine particles of crystallized titanium oxide can be obtained. The heat treatment or the autoclave treatment is carried out at 80 ° C or higher to sufficiently crystallize the titanium oxide. The titanium oxide ultrafine particles of the thus-produced titanium oxide dispersion preferably have an average particle diameter of 10 nm or less, more preferably 1 to 6 nm. When the average particle diameter of the titanium oxide ultrafine particles is 10 nm or less, the film forming property is excellent (when the film is formed by drying after coating, the film thickness is 1 μm or more, and cracking does not occur). Further, when the average particle diameter of the titanium oxide ultrafine particles is 1 nm or more, the surface treatment composition can be maintained in a state in which the viscosity is not high. The titanium oxide dispersion has a translucent appearance. Such a titanium oxide dispersion can also be used as an aqueous liquid (A) containing titanium.

The surface-treated composition (H) containing the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a is applied onto the surface of a gold-plated steel sheet, and dried (for example, dried at a low temperature) to form an excellent one. Adhesive dense titanium oxide-containing film (surface treated film).

The heating temperature of the steel sheet after the surface treatment composition (H) is applied is, for example, 200 ° C or lower, particularly preferably 150 ° C or lower, and by heating and drying at this temperature, an amorphous oxidation containing a plurality of hydroxyl groups can be formed. Titanium film.

In addition, when the titanium oxide dispersion liquid obtained by the heat treatment at 80 ° C or higher or the autoclave treatment is used as the aqueous liquid (A) containing titanium, the surface-treated composition (H) can be used to form a crystalline titanium oxide. The film is suitable for the coating agent of the material without heat treatment.

Further, an aqueous liquid (A) containing titanium may be used, and an aqueous liquid (A1) containing titanium obtained by reacting a hydrolyzable titanium compound a with hydrogen peroxide in a titanium oxide sol may be used.

The titanium oxide sol is a sol obtained by dispersing water in an amorphous titanium dioxide fine particle or/and an anatase-based titanium oxide fine particle (if necessary, an aqueous organic solvent such as an alcohol-based or alcohol ether-based solvent). The titanium oxide sol can be obtained by hydrolyzing an organic titanium compound such as (i) titanium oxide solution obtained by hydrolysis of a titanium-containing solution such as titanium sulfate or titanyl sulfate, or (ii) an alkali titanium compound such as titanium alkoxide. An amorphous titanium dioxide sol obtained by dispersing a titanium oxide agglomerate such as a titanium oxide agglomerate, (iii) a titanium halide solution such as titanium tetrachloride, or a titanium oxide aggregate obtained by neutralization, in water, or the above-mentioned titanium oxide agglomerate calcination After the anatase type titanium fine particles are obtained, the substance is dispersed in a sol obtained by water.

When the amorphous titanium dioxide is calcined, the amorphous titanium oxide can be converted into anatase titanium dioxide by baking at a temperature higher than the crystallization temperature of the anatase, for example, at a temperature of 400 ° C to 500 ° C or higher. The aqueous sol of titanium dioxide is, for example, TKS-201 (trade name, manufactured by Tieka Co., 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 crystal form).

In the aqueous liquid (A1) containing titanium, the mass ratio x/y of the titanium oxide sol x to the titanium hydrogen peroxide reactant y (reaction product of the hydrolyzable titanium compound a and hydrogen peroxide water) may be 1/99. Up to 99/1, preferably about 10/90 to 90/10. When the mass ratio x/y is 1/99 or more, the effect of sufficiently adding a titanium oxide sol can be obtained from the viewpoints of stability, photoreactivity, and the like, and it is preferable that an excellent film forming property is obtained at 99/1 or less.

The aqueous liquid (A1) containing titanium can be obtained by reacting the hydrolyzable titanium compound a with hydrogen peroxide in a titanium oxide sol at a reaction temperature of 1 to 70 ° C for 10 minutes to 20 hours.

The formation 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, and particularly when a titanium oxide sol is used, partial condensation reaction during synthesis can be suppressed. sticky. The reason for this is that the condensation reaction product is adsorbed on the surface of the titanium oxide sol, and the polymerization in a solution state can be suppressed.

Further, when the aqueous liquid (A1) containing titanium is heated at 80 ° C or higher or autoclaved, a titanium oxide dispersion containing ultrafine particles of crystallized titanium oxide can be obtained. The temperature conditions for producing the titanium oxide dispersion, the particle size of the crystallized titanium oxide ultrafine particles, and the appearance of the dispersion are the same as those of the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a. This titanium oxide dispersion can also be used as an aqueous liquid (A1) containing titanium.

Further, similarly to the titanium-containing aqueous liquid (A) using the hydrolyzable titanium compound a, the surface-treated composition (H) containing the aqueous liquid (A1) containing titanium is applied onto the surface of the plated steel sheet and dried (for example). After drying at a low temperature, a dense titanium oxide-containing film (surface treatment film) having excellent adhesion thereto can be formed.

The heating temperature of the steel sheet after the surface treatment composition (H) is applied is, for example, 200 ° C or lower, particularly preferably 150 ° C or lower, and heating and drying at this temperature can form an anatase-type titanium oxide-containing coating containing a plurality of hydroxyl groups.

In the aqueous liquid (A) containing titanium as described above, the aqueous liquid (A) containing titanium and the aqueous liquid (A1) containing titanium of the hydrolyzable titanium compound a have excellent storage stability and corrosion resistance. Therefore, the present invention is particularly preferred for use.

The titanium compound having at least one selected from the group consisting of a hydrolyzable titanium compound, a low condensate of a hydrolyzable titanium compound, a titanium oxyhydroxide, and a low condensate of titanium hydroxide, is preferably added in a ratio of hydrogen peroxide water. It is 0.1 to 100 parts by mass, more preferably 1 to 20 parts by mass, based on 10 parts by mass of the titanium compound in terms of hydrogen peroxide. When the ratio of addition of hydrogen peroxide is 0.1 parts by mass or more in terms of hydrogen peroxide, it can be sufficiently chelated to form a white turbid precipitate, and no unreacted hydrogen peroxide remains in 100 parts by weight or less, during storage. It is better not to release active oxygen.

The hydrogen peroxide concentration of the hydrogen peroxide water is not particularly limited, but the solid content of the coating liquid for the coating workability is preferably from 3 to 30 mass%.

The aqueous liquid (A) containing titanium may be added to disperse other sols and pigments as necessary. For the additive, for example, a commercially available titanium oxide sol, a titanium oxide powder, a mica, a talc, an anthracene, a clay, or the like may be added.

The surface treatment composition contains the content of the aqueous liquid (A) of titanium, and the solid content is preferably from 1 to 100 g/L, more preferably from 5 to 50 g/L, from the viewpoint of stability of the treatment liquid and the like.

The surface treatment composition of the present invention is characterized in that the aqueous solution containing titanium (A) is added with a zirconium carbonate compound (B) to further improve the corrosion resistance and even the organic resin coating layer (the organic resin layer formed by lamination or coating) The anti-rust can be used to lift the corrosion resistance of the coated organic resin layer. Further, the organic phosphoric acid compound (C) can improve the reactivity with the steel sheet to improve the corrosion resistance, and obtain a good storage stability of the surface treatment composition. Further, the addition of the metal phosphate (D) and the cerium oxide (E) can enhance the organic resin layer formed by the upper layer, particularly a thick organic resin layer having a thickness of 100 μm or more (for example, an organic resin layer formed by lamination). The adhesion at the time of deformation of the steel sheet and the addition of the decane coupling agent (G) can also improve the adhesion (adhesiveness to the above-mentioned thick organic resin layer) in a severe environment such as a high-temperature wet environment. Further, the addition of the water-soluble organic resin and/or the water-dispersible organic resin (F) can improve the scratch resistance of the surface-treated film, and an excellent corrosion resistance can be found even when the surface-treated film is formed and contacted with the roll.

The zirconium carbonate compound (B) is preferably zirconium ammonium carbonate or zirconium oxycarbonate, and the corrosion resistance can be improved by using one or more of these. The amount of the zirconium carbonate compound (B) to be added is 10 to 300 parts by mass, preferably 50 to 100 parts by mass, per 100 parts by mass of the solid content of the aqueous liquid (A) containing titanium. When the amount of the zirconium carbonate compound (B) is less than 10 parts by mass based on 100 parts by mass of the solid content of the aqueous liquid (A) containing titanium, the effect of improving the corrosion resistance is reduced, and when it exceeds 300 parts by mass, the density tends to be dense. The quality is worse.

The organic phosphoric acid compound (C) is preferably, for example, 1-hydroxymethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxypropane-1,1-diphosphonic acid, or the like. a hydroxyl group-containing organic phosphorous acid; a 2-hydroxyphosphonaki acetic acid; a 2-phosphonium butane-1,2,4-tricarboxylic acid-containing carboxyl group-containing organic phosphorous acid, and the like; One or two or more of these may be used.

The organic phosphoric acid compound (C) has an effect of improving corrosion resistance and storage stability of the aqueous liquid (A) containing titanium, and the effect of 1-hydroxyethane-1,1-phosphonic acid is particularly large, so It is especially good to use it.

The amount of the organic phosphate compound (C) to be added is 50 to 200 parts by mass based on 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), and particularly preferably 70 to 150 parts by mass in terms of water resistance and the like. When the amount of the organic phosphate compound (C) added is less than 50 parts by mass based on 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A), the storage stability of the surface-treated composition is deteriorated, and the corrosion resistance is also lowered. . Moreover, when it exceeds 200 mass parts, water-resistant adhesion will worsen.

The metal phosphate (D) and the cerium oxide (E) are added to the organic resin layer formed on the upper layer by lamination or the like, in particular, the adhesion of the thick organic resin layer having a thickness of 100 μm or more. In the case of the cerium oxide (E), the liquid phase cerium oxide produced by the liquid phase reaction method, or the amorphous cerium oxide such as the gas phase cerium oxide produced by the dry method, one or more of these may be used. . The specific liquid phase cerium oxide can be obtained from Nissan Chemical Industry Co., Ltd., which is made of Snow, which is registered in the company, O, N, 20, 30, 40, C, S, and gas phase cerium oxide. AREROSIL (registered trademark) 130, 200, 200V, 200CF, 300, 300CF, etc.

Among them, the gas phase cerium oxide is excellent in terms of adhesion to the organic resin layer, and good performance can be obtained.

Further, the type of the metal phosphate (D) is not particularly limited, and among them, an aluminum salt, a magnesium salt, and a manganese salt are effective. In particular, the aluminum salt has the advantage of reducing the solubility of the phosphate and the effect of continuously humidifying the environment. One type or two or more types of the above metal phosphates can be used. Further, the metal phosphate (D) is preferably a phosphoric acid/metal cation component which can be present in an aqueous solution as a commercially available aqueous solution of phosphorus-rich rock.

When the metal phosphate (D) and the cerium oxide (E) are added to the surface treatment composition, it is preferred to mix the metal phosphate (D) and the cerium oxide (E) in advance and add them as a mixture. When it is added in a state of being premixed, it is possible to obtain better adhesion and corrosion resistance when compared with each other. Although the reason is not clear, it is estimated that the effect of using a phosphoric acid component can increase the cohesive force of the film obtained from the surface treatment composition. Moreover, mixing with this method can enhance the storage stability of the surface treatment composition.

Further, when cerium oxide (E) is produced by a dry method of cerium oxide (gas phase cerium oxide), a gas phase cerium oxide can be added to a metal phosphate aqueous solution to be dispersed in a metal phosphate aqueous solution by strong stirring. The cerium oxide dispersion obtained from the gas phase cerium oxide is mixed with other components. At the same time, the surface treatment composition can be prepared by vigorously stirring the gas phase cerium oxide and the metal phosphate aqueous solution with other added components and water.

Further, when the gas phase cerium oxide is dispersed in the surface treatment composition by a sand mixer or the like, aggregation occurs in one week to several weeks to form a precipitate. Although the detailed mechanism is not clear, it is judged that the coagulation is less likely to occur when the gas phase ceria having a lower specific gravity is used, and the storage stability (solution stability) can be effectively improved. Specifically, it is preferred to use a gas phase cerium oxide having a bulk specific gravity of 40 g/L or less. The volume specific gravity of the gas phase ceria can be adjusted by controlling the degassing conditions after the dry process, whereby a gas phase ceria having a small specific gravity can be obtained.

The reason for adding the adhesion between the metal phosphate (D) and the cerium oxide (E) to the organic resin layer is that the addition of cerium oxide and metal phosphate can change the surface polarity of the surface treated film, which is advantageous for the adhesion. Sex. The polarity of the cerium oxide may be increased by directly applying the organic resin layer to the upper layer and interposing the organic resin film with the adhesive, thereby increasing the adhesion to the resin layer and the adhesive layer. However, when the polarity is too high, it is easy to inhale moisture and swell in a humid environment, which is disadvantageous. The relatively non-polar phosphoric acid (metal phosphate) is added to achieve a moderate surface polarity by making the adhesion and the stability at the time of wetting. Further, in the case of secondary aggregation of cerium oxide, surface unevenness at the submicron order level is formed, and the surface unevenness is formed to increase the effective area of the adhesion interface. Therefore, it is estimated that an effective effect can be obtained with respect to the adhesion. Although the influence of the addition of metal phosphate on the surface properties cannot be fully understood, it is inferred that the secondary coagulation of cerium oxide affects the surface properties.

The ratio of the amount of the metal phosphate (D) added to the total solid content of the surface treatment composition is 2 to 20 mass%, preferably 2 to 8 mass%, and the amount of cerium oxide (E) added to the surface treatment composition is The ratio in the solid fraction is 20 to 40 mass%.

When the amount of the metal phosphate (D) added to the total solid content of the surface treatment composition is less than 2 mass%, the effect is not exhibited, and the adhesion to the steel sheet is insufficient. In addition, when it is added in excess of 20 mass%, the performance such as blackening during storage until the coating of the organic resin layer is deteriorated. Further, when the amount of the metal phosphate (D) added exceeds 8 mass%, the liquid stability during storage tends to be lowered.

When the proportion of the cerium oxide (E) added to the total solid content of the surface treatment composition is less than 20 mass%, the unevenness of the submicron size formed will be insufficient, and the organic resin layer of the upper layer will not be obtained when the processing is too strict. Fully adhered. In addition, when it exceeds 40 mass%, the object which is excellent in adhesion will be damaged by the surface treatment film, and the film will be damaged when it contacts the roller or the like. Therefore, it is needless to say that the bare corrosion resistance is even after the organic resin is coated. The starting point is corroded.

The water-soluble organic resin and/or the water-dispersible organic resin (F) is an organic resin which can be dissolved or dispersed in water, and a method of water-solubilizing or water-dispersing an organic resin in water is applied to a previously known method. Specifically, an organic resin may be used, and a functional group (for example, a hydroxyl group, a polyoxyalkylene group, a carboxyl group, an amine (imine) group, a sulfide group, a phosphino group, or the like) which can be separately water-solubilized or water-dispersed may be used. And if necessary, part or all of the functional groups may be an amine resin such as an ethanol resin or a triethylamine such as an acidic resin (a resin containing a carboxyl group); chlorine water; lithium hydroxide, sodium hydroxide, potassium hydroxide The substance neutralized with an alkali metal oxide or the like may be a fatty acid such as acetic acid or lactic acid of a basic resin (an amine group-containing resin or the like), or a neutralized product of a mineral acid such as phosphoric acid.

Water-soluble or water-dispersible organic resin such as epoxy resin, phenol resin, acrylic resin, urethane resin, olefin-carboxylic acid resin, nylon resin, resin having polyalkylene oxide chain , polyvinyl alcohol, polyglycerin, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and the like. One type or two or more types of the above organic resins can be used.

Among these, it is particularly preferable in terms of storage stability of the surface treatment composition, and at least one selected from the group consisting of water-soluble or water-dispersible acrylic resin, urethane resin, and epoxy resin. The organic resin is particularly preferable in terms of the balance between the storage stability of the surface treatment composition and the coating film property, and a water-soluble or water-dispersible acrylic resin or a urethane-based resin as a main component.

The water-soluble or water-dispersible acrylic resin can be synthesized by solution polymerization by a previously known method such as an emulsion polymerization method, a suspension polymerization method, or a hydrophilic group, and if necessary, can be neutralized and water-based. The method of chemistry is obtained.

The polymer having a hydrophilic group can be, for example, polymerized with an unsaturated group having a hydrophilic group such as a carboxyl group, an amine group, a hydroxyl group or a polyepoxyalkyl group, and if necessary, can be polymerized otherwise. Saturated monomer derived.

The water-soluble or water-dispersible acrylic resin is preferably a copolymer of styrene in terms of corrosion resistance and the like, and the amount of styrene in the wholly unsaturated monomer is preferably from 10 to 60 mass%, particularly preferably from 15 to 50mass%. Further, the Tg (glass transition point) of the obtained acrylic resin is preferably from 30 to 80 ° C, particularly preferably from 35 to 70 ° C, from the viewpoint of the toughness of the obtained film.

The above carboxyl group-containing unsaturated monomer such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, crotonic acid, itaconic acid or the like.

The above nitrogen-containing unsaturated monomer containing an amino group-containing unsaturated monomer or the like, for example, N,N-dimethylaminoethyl (meth) acrylate, N,N-diethylaminoethyl (A) Nitrogen-containing alkyl (meth) acrylate such as acrylate, Nt-butylaminoethyl (meth) acrylate, etc.; acrylamide, methacrylamide, N-methyl (methyl) Acrylamide, N-ethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxy (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-dimethyl A polymerizable guanamine such as aminoethyl (meth) acrylamide; an aromatic nitrogen-containing monomer such as 2-vinylpyridine, 1-vinyl-2-pyrrolidone or 4-vinylpyridine; Alkylamine and the like.

The above hydroxyl group-containing unsaturated monomer such as 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxyl group a monoester of a polyvalent alcohol such as butyl (meth) acrylate, polyethylene glycol mono (meth) acrylate or polypropylene glycol mono (meth) acrylate with acrylic acid or methacrylic acid; the above polyvalent alcohol A compound obtained by ring-opening polymerization of ε-butyrolactone with a monoester of acrylic acid or methacrylic acid.

Other unsaturated monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl Alkyl groups having 1 to 24 carbon atoms such as (meth) acrylate, tridecyl (meth) acrylate, octadecyl (meth) acrylate, isostearyl hydrazine (meth) acrylate ( Methyl) acrylate; vinyl acetate, and the like.

The above-exemplified unsaturated monomers may be used alone or in combination of two or more. The "(meth) acrylate" described in the present application means "acrylate or methacrylate".

The urethane-based resin is preferably a polyurethane formed from a polyol such as a polyester polyol or a polyether polyol and a diisocyanate, and if necessary, a diol, a diamine or the like is present. In the case of a chain extender of a low molecular weight compound of two or more active hydrogens, a previously known substance which is stably dispersed or dissolved in water by chain elongation can be widely used (for example, refer to Japanese Patent Publication No. Sho 42-24192, Japanese Patent No. 42 Japanese Unexamined Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei.

As a method of dispersing or dissolving the polyurethane 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 amine group or a carboxyl group into a branch or a terminal of a polyurethane polymer, and dispersing or dissolving it in water by self-emulsification.

(2) using an emulsifier or a mechanical shearing force, the polyurethane obtained by the end of the reaction or a blocker of hydrazine, alcohol, phenol, thiol, amine, bisulfite, etc. A method in which a polyurethane polymer obtained from an isocyanate group block is forcibly dispersed in water. Further, a method of simultaneously dispersing and polymerizing a urethane polymer having a terminal isocyanate group and water, an emulsifier, and a chain extender by mechanical shearing force is used.

(3) Polyol The main raw material polyol is a method in which a polyethylene glycol-like water-soluble polyol is dispersed or dissolved in water in the form of a water-soluble polyurethane.

The polyurethane resin may be used in combination with a method different from the above dispersion or dissolution methods.

A diisocyanate such as an aromatic, alicyclic or aliphatic diisocyanate which can be used for the synthesis of the above polyurethane resin, specifically, for example, hexamethylene diisocyanate, tetramethylammonium diisocyanate, 3,3 '-Dimethoxy-4,4'-linked phenyl diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 1,3-(diisocyanatomethyl)cyclohexane Ketone, 1,4-(diisocyanatomethyl)cyclohexanone, 4,4'-diisocyanatocyclohexanone, 4,4'-extended methyl bis(cyclohexyl isocyanate), different buddha Mercapone diisocyanate, 2,4-tolyl diisocyanate, 2,6-tolyl diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, 2, 4-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-linked phenyl diisocyanate, 4,4'-linked phenyl diisocyanate, and the like. Among them, particularly preferred are 2,4-tolyl diisocyanate, 2,6-tolyl diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

Commercial products such as Hydralan (registered trademark) HW-330, HW-340, and HW-350 (all of which are trade names, manufactured by Dainippon Ink Chemical Industry Co., Ltd.) and superbend ( Registered trademarks) 100, 150, E-2500, and F-3438D (all trade names, manufactured by Daiichi Kogyo Co., Ltd.).

The epoxy resin is a cationic epoxy resin obtained by adding an amine to an epoxy resin; a modified epoxy resin such as an acrylic acid modification or a urethane modification. a cationic epoxy resin such as an adduct of an epoxy compound with a primary mono- or polyamine, a 2-stage mono- or polyamine, a 1,2-stage mixed polyamine (for example, refer to US Pat. No. 3,984,299); an epoxy compound An adduct of a ketone-imidized 2-stage mono- or polyamine having a 1st-order amine group (for example, refer to the specification of U.S. Patent No. 4017438); an epoxy compound and a ketone-imidized amine having a grade 1 amine group An etherification reaction product of a hydroxy compound (for example, JP-A-59-43013).

The epoxy resin is preferably a number average molecular weight of 400 to 4,000, particularly preferably 800 to 2,000, an epoxy equivalent of 190 to 2,000, and particularly preferably 400 to 1,000. Such an epoxy resin can be obtained, for example, by reacting a polyphenol compound with epichlorohydrin, such as bis(4-hydroxyphenyl)-2,2-propane or 4,4-dihydroxybenzophenone. Ketone, 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, tetrakis(4-hydroxyphenyl)-1,1,2 , 2-ethane, 4,4-dihydroxydiphenyl hydrazine, phenol novolak, cresol novolac, and the like.

The water-soluble organic resin and / or the water-dispersible organic resin (F) is added in an amount of from 2 to 10 mass% in the total solid content of the surface-treated composition. The water-soluble organic resin and/or the water-dispersible organic resin (F) is added in such a manner that when the ratio of the total solid content of the surface-treated composition is less than 2 mass%, the brittleness of the surface-treated film cannot be improved, and the surface-treated film is formed. Since the rear contact roller or the like brings the flaw into the film, it is not necessary to mention the bare corrosion resistance, and the organic resin is coated and the corrosion is started from the wound portion. Moreover, when it exceeds 10 mass%, heat-resistant discoloration property and adhesiveness after processing will fall.

Decane coupling agent (G) such as vinyl methoxy decane, vinyl ethoxy decane, vinyl trichloro decane, vinyl trimethoxy decane, vinyl triethoxy decane, β- (3, 4 ring Oxycyclohexyl)ethyltrimethoxydecane, γ-glycidoxypropyltrimethoxydecane, γ-glycidoxypropylmethyldiethoxydecane, γ-glycidoxypropane Triethoxy decane, N-β (aminoethyl) γ-aminopropyl methyl dimethoxy decane, N-β (aminoethyl) γ-aminopropyl trimethoxy decane, N-β (aminoethyl) γ-aminopropyl triethoxy decane, γ-aminopropyl trimethoxy decane, γ-aminopropyl triethoxy decane, γ-methyl propylene oxide Propylmethyldimethoxydecane, γ-methylpropenyloxypropyltrimethoxydecane, γ-methylpropoxypropylmethyldiethoxydecane, γ-methylpropenyloxy Propyltriethoxydecane, γ-mercaptopropylmethyldimethoxydecane, γ-mercaptopropyltrimethoxydecane, p-styryltrimethoxydecane, γ-acryloxypropyltrimethoxy Baseline, N-phenyl-γ-aminopropyltrimethoxydecane Γ-ureidopropyltriethoxydecane, γ-chloropropyltrimethoxydecane, bis(triethoxydecylpropyl)tetrasulfide, γ-isocyanatepropyltriethoxydecane, γ- Triethoxydecyl-N-(1,3-dimethyl-butylene)propylamine, N-(vinylbenzylamine)-β-aminoethyl-γ-aminopropyltrimethoxy One or two or more of these may be used. Among them, the viewpoint of improving corrosion resistance is preferably a glycidyl-based decane coupling agent, particularly preferably γ-glycidoxypropyltrimethoxydecane or γ-glycidoxypropylmethyldiethoxylate. Decane, γ-glycidoxypropyltriethoxydecane.

As a result of review by the present inventors, as a result of the surface-resistance of the film, it is impossible to obtain a composite effect of only the metal phosphate (D) and the cerium oxide (E) at the concentration of the cerium oxide (E). In order to solve the above problems and improve the adhesion in a high temperature and humidity environment, it is judged that the addition of a decane coupling agent has an effect in order to solve the above problems in order to solve the above problems and to improve the adhesion under a high temperature and humidity environment. . However, when the organic resin and the cerium oxide are used together with the decane coupling agent, the liquid stability during storage tends to be lowered, and by suppressing the concentration of the metal phosphate (D), the problem does not occur, and the adhesion is not deteriorated when the processing is excessively performed. It can improve the adhesion under high temperature and humid environment (especially the adhesion with thick organic resin layer).

The decane coupling agent (G) is added in an amount of from 0.5 to 20 mass%, preferably from 0.5 to 10 mass%, based on the total solid content of the surface treatment composition. The amount of the decane coupling agent (G) added is such that when the ratio of the total solid content of the surface treatment composition is less than 0.5 mass%, the adhesion in a high-temperature humid environment cannot be sufficiently improved, and when it exceeds 20 mass%, the liquid is lowered. Stability, increase costs.

The pH of the surface treatment composition is preferably adjusted to 7 to 12. When the pH is less than 7 and exceeds 12, the surface treatment composition is agglomerated over time, and the film cannot be formed.

The surface treatment composition of the present invention may contain, for example, an etchant such as resin fine particles or an inorganic phosphate compound, and a heavy metal compound, a tackifier, a surfactant, and a lubricity imparting agent (polyethylene) other than the components specified in the present invention. Wax, fluorine-based wax, carnauba wax, etc.), rust inhibitors, coloring pigments, extender pigments, rust-preventive pigments, dyes, and the like.

Moreover, the surface treatment composition of the present invention can be diluted, for example, with a hydrophilic solvent such as methanol, ethanol, isopropyl alcohol, ethylene glycol solvent or propylene glycol solvent.

The surface treatment composition of the present invention preferably has a solid content of from 2 to 10 mass% from the viewpoints of storage stability and stability at the time of coating.

The surface treatment composition of the present invention can be used as a surface treatment agent for various metal materials, but is particularly preferably used as a surface treatment agent for a galvanized steel sheet or an aluminum-plated steel sheet to be described later.

The surface-treated steel sheet of the present invention is coated on the surface of a galvanized steel sheet or an aluminum-plated steel sheet, and is coated with the above surface treatment composition, that is, an aqueous liquid solution containing titanium (A), a zirconium carbonate compound (B), and an organic phosphoric acid compound. (C), metal phosphate (D), cerium oxide (E), water-soluble organic resin or / and water-dispersible organic resin (F), and surface treatment composition of decane coupling agent (G), dried and formed The surface treatment film having a certain amount of film adhesion. The surface treatment film does not contain hexavalent chromium (except for the hexavalent chromium which is unavoidable).

Further, the aqueous liquid (A) containing titanium and the surface treatment composition may contain other additives listed above as necessary.

The galvanized steel sheet of the substrate of the surface-treated steel sheet of the present invention may be, for example, a galvanized steel sheet, a Zn-Ni alloy plated steel plate, a Zn-Fe alloy plated steel plate (a plated steel plate, a plated alloyed molten zinc plate), or a Zn-Cr alloy plated. Steel plate, Zn-Mn alloy plate, Zn-Co alloy plate, Zn-Co-Cr alloy plate, Zn-Cr-Ni alloy plate, Zn-Cr-Fe alloy plate, Zn-Al alloy plate For example, a Zn-5 mass% Al alloy steel plate, a Zn-55 mass% Al alloy steel plate, a Zn-Mg alloy steel plate, a Zn-Al-Mg alloy steel plate, and a gold-plated coating of such a gold-plated steel plate are dispersed in a metal oxide. A galvanized composite steel sheet such as a polymer (for example, a Zn-SiO ₂ -distributed steel sheet). Further, in the above gold plating, a two-layer or more multi-layer gold-plated steel sheet of the same type or a different type may be used.

Further, the aluminum-plated steel sheet of the substrate of the surface-treated steel sheet of the present invention may be used, an aluminum-plated steel sheet or an Al-Si alloy-plated steel sheet.

Further, in the gold-plated steel sheet, the steel sheet surface may be previously subjected to a thin layer of Ni or the like, and the above various gold plating materials may be further applied thereto.

The gold plating method may be any method which can be carried out by an electrolytic method (electrolysis in an aqueous solution or electrolysis in a nonaqueous solvent), a melting method, or a gas phase method.

Further, in order to form a surface-treated film on the surface of the gold-plated film, film defects and spots are not generated, and if necessary, alkali degreasing, solvent degreasing, and surface conditioning treatment (alkaline surface conditioning treatment or acid surface conditioning treatment) may be performed on the surface of the gold plating film in advance. ) and so on.

In addition, in order to prevent blackening in the use environment (one of the gold plating surface oxidation phenomenon), an acid or a base containing an iron group metal ion (one or more of Ni ions, Co ions, and Fe ions) may be applied to the gold plating surface in advance if necessary. Surface conditioning treatment of aqueous solutions.

When an electrogalvanized steel sheet is used as the underlayer steel sheet, iron group metal ions (one or more of Ni ions, Co ions, and Fe ions) may be added to the plating bath to prevent blackening, and the gold plating film may be contained in an amount of 1 mass ppm or more. Wait for the metal. The upper limit of the concentration of the iron group metal in the gold plating film at this time is not particularly limited.

The adhesion amount of the surface treatment film formed by the surface treatment composition is from 0.03 to 0.5 g/m ² . When the amount of the film adhered is less than 0.03 g/m ² , the corrosion resistance is deteriorated, and when it exceeds 0.5 g/m ² , the film is easily broken, and the adhesion of the excessively processed film after the coating of the organic resin is lowered.

When the surface-treated steel sheet of the present invention is produced, the above surface-treated composition is used. That is, an aqueous liquid (A) containing titanium, a zirconium carbonate compound (B), an organic phosphoric acid compound (C), a metal phosphate (D), cerium oxide (E), a water-soluble organic resin or/and a water-dispersible organic resin ( F) The surface treatment composition (treatment liquid) of the decane coupling agent (G) is applied to the surface of a galvanized steel sheet or an aluminum-plated steel sheet, and then directly dried without washing with water.

Further, the aqueous liquid (A) containing titanium and the surface treatment composition may contain other additives as listed above as necessary.

The coating method of the surface treatment composition (treatment liquid) may be, for example, spray + roll extrusion, roll coating, or the like, and the drying method after coating may be, for example, a hot air method, a derivative heating method, or an electric furnace method. Wait.

The drying temperature (steel plate temperature) of the surface treatment composition (treatment liquid) after coating is preferably from 60 to 200 °C. When the drying temperature is 60° C. or more, it is possible to sufficiently form a film having excellent corrosion resistance and the like. Further, when the drying temperature is 200 ° C or lower, the film is not cracked by heat, so that the effect of sufficiently improving the corrosion resistance can be obtained. Further, the drying temperature is preferably from 60 to 140 ° C, more preferably from 60 to 100 ° C.

Moreover, the organic resin-coated steel sheet of the present invention is an article in which an organic resin layer is formed on the surface treatment film of the surface-treated steel sheet described above. The method of forming the organic resin layer may be any method, for example, a method of applying a coating composition for re-drying or a method of laminating an organic resin film, or the like.

Further, since the surface-treated film of the present invention has excellent adhesion to a thick organic resin layer having a thickness of 100 μm or more, the organic resin-coated steel sheet of the present invention is particularly suitably used when the thickness of the organic resin layer is 100 μm or more.

At this time, various additives including a non-chromium-based rust preventive additive, a solid lubricant, a coloring pigment, and the like can be added to the organic resin layer.

Example

The titanium-containing aqueous liquid (A) and the components (B) to (G) used for the surface treatment composition are as follows. [Manufacture of aqueous liquid containing titanium (A)]

‧Manufacturing Example 1 (aqueous liquid T1 containing titanium)

Aqueous ammonia (1:9 = ammonia: water mass ratio) was dropped into a solution obtained by distilling water to make 5 cc of titanium tetrachloride 60 mass% solution into 500 cc, and a low condensate of titanium hydroxide was precipitated. After washing with distilled water, 10 cc of a 30 mass% solution of hydrogen peroxide water was added to obtain a yellow translucent titanium-containing aqueous liquid T1 containing titanium.

‧Manufacturing Example 2 (aqueous liquid T2 containing titanium)

a mixture of 10 parts by mass of tetraiso-propoxytitanium and 10 parts by mass of iso-propanol in a mixture of 10 parts by mass of 30 mass% hydrogen peroxide water and 100 parts by mass of deionized water in a stirred state at 20 ° C for 1 hour. in. Thereafter, the mixture was aged at 25 ° C for 2 hours to obtain a yellow transparent aqueous solution T2 containing a slightly viscous titanium.

‧Manufacturing Example 3 (aqueous liquid T3 containing titanium)

The aqueous liquid T3 containing titanium was obtained except that the four iso-propoxy titanium used in Production Example 2 was replaced with tetra-n-butoxytitanium in the same production conditions as in Production Example 2.

‧Manufacturing Example 4 (aqueous liquid T4 containing titanium)

The same manufacturing conditions as in Production Example 2 were carried out except that the tetraiso-propoxytitanium terpolymer (low isocondensate of tetraiso-propoxytitanium) was substituted for the four iso-propoxytitanium used in Production Example 2. An aqueous liquid T4 containing titanium is obtained.

‧Manufacturing Example 5 (aqueous liquid T5 containing titanium)

Titanium-containing aqueous solution T5 was obtained except that three times the amount of hydrogen peroxide water was used in the production example 2, and the mixture was dropped at 50 ° C for 1 hour, and then cooked at 60 ° C for 3 hours.

‧Manufacturing Example 6 (aqueous liquid T6 containing titanium)

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.

‧Manufacturing Example 7 (aqueous liquid T7 containing titanium)

A mixture of 10 parts by mass of tetraiso-propoxytitanium and 10 parts by mass of iso-propanol was added to the stirred "TKS-203" (trade name, manufactured by Tieka Co., Ltd., titanium oxide sol) at 10 ° C for 1 hour. 5 parts by mass (solid content), 30 mass% of hydrogen peroxide water, 10 parts by mass, and 100 parts by mass of deionized water. Thereafter, the mixture was aged at 10 ° C for 24 hours to obtain a yellow transparent aqueous solution T7 containing a slightly viscous titanium.

[Zirconium compound (B)]

B1: ammonium zirconium carbonate

B2: zirconium oxycarbonate

B3: Zirconium ammonium fluoride

[Organic Phosphate Compound (C)]

C1:1-hydroxymethane-1,1-diphosphonic acid

C2: 1-hydroxyethane-1,1-diphosphonic acid

[Mixed metal phosphate (D) and cerium oxide (E) mixture]

According to the solid content addition ratio shown in Table 3, Table 5, Table 7, Table 9, and Table 11, the cerium oxide (E) is added to the aqueous solution of the metal phosphate (D) and stirred vigorously to obtain a metal phosphate aqueous solution dispersed cerium oxide. mixture. Further, the comparative examples of No. 92 in Tables 9 and 10 contained only ruthenium oxide E4.

‧ metal phosphate (D)

D1: First generation aluminum phosphate

D2: First generation magnesium phosphate

D3: First generation manganese phosphate

‧Oxide (E)

E1: Ai Luoji 300 (trade name, Japan Ai Luoji (stock) system, gas phase cerium oxide, volume specific gravity: 50 g / L)

E2: Ai Luoji 200 (trade name, Japan Ai Luoji (stock) system, gas phase cerium oxide, volume specific gravity: 35g / L)

E3: Snow Iron O (trade name, Nissan Chemical Industry Co., Ltd., colloidal cerium oxide)

E4: Ai Luoji 300CF (trade name, Japan Ai Luoji (stock) system, gas phase cerium oxide, volume specific gravity: 35g / L)

[Water-soluble or water-dispersible organic resin (F)]

Among the water-soluble or water-dispersible organic resins, the water-dispersible acrylic resins of F1 to F5 are produced by the following Production Examples 8 to 12, and the commercial products of F6 to F13 are used. Moreover, the "parts" and "%" of the following manufacturing examples are the quality standards.

‧Manufacturing Example 8 (water-dispersible acrylic resin F1)

665 parts of deionized water, 9 parts of Ekron RN-50 (Note 1), 87 parts of Ekron RN-2025 (Note 2), and forced emulsification of monomer mixture 1 (paragraph 1) of the following composition 5% (28.9 parts) of the pre-emulsion was placed in a 2-liter 4-liter flask equipped with a reflux condenser, a stirrer, a thermometer, and a dropping funnel, and the temperature was raised by nitrogen substitution.

"Monomer Mix 1"

Deionized water 166.5 parts

Akulon RN-50 6.6

Akuron RN-2025 53 copies

Styrene 35 parts

Methyl methacrylate 163.5 parts

2-ethylhexyl acrylate 105 parts

2-hydroxyethyl methacrylate 5 parts

Methacrylic acid 3 parts

Acrylonitrile 38.5 parts

Tert-dodecanethiol 1 part

When it reaches 55 ° C or higher, 5 parts of butyl peroxide (4. 3 parts) and 2.5 parts of sodium formaldehyde sulfoxylate dissolved in 83.5 parts of deionized water are added to dissolve in 83.5 parts of deionized water. 5% (4.3 parts) of the aqueous reducing agent solution was heated to maintain the temperature at 60 °C. After 15 minutes from the addition, the remaining pre-latex was added over 1.5 hours, and the aqueous solution of the oxidizing agent was added over 3.5 hours, and the aqueous reducing agent solution was added dropwise over 3.5 hours. The aqueous solution of the oxidizing agent and the aqueous solution of the reducing agent were continuously dropped, and the pre-emulsion drip of the first stage was completed for 1 hour, and then the monomer mixture 2 of the following composition was dropped into the second step (second stage).

"Monomer Mix 2"

Styrene 15 parts

Methyl methacrylate 84.5 parts

2-ethylhexyl acrylate 22.5 parts

2-hydroxyethyl methacrylate 4.25 parts

Methacrylic acid 6 parts

Acrylonitrile 15 parts

γ-Methyl propylene methoxy propyl trimethoxy decane 2.75 parts

After the completion of all the dripping, the temperature was maintained at 60 ° C for 1 hour, after which the temperature was lowered to below 40 ° C, and then 3.35 parts of 25% ammonia water, 0.35 parts of Slao EX (Note 4), 2, 2, 4-38 83.5 parts of 1,3-pentanediol monoisobutyrate to obtain a water-dispersible acrylic resin F1 having a pH of 8.0 and a nonvolatile content of 31%.

(Note 1) Akulon RN-50, trade name, first industrial pharmaceutical (stock) system, non-ionic emulsifier, solid content 60%

(Note 2) Akulon RN-2025, trade name, first industrial pharmaceutical (stock) system, non-ionic emulsifier, solid content 25%

(Note 3) Perbutyl H, trade name, manufactured by Nippon Oil & Fats Co., Ltd., t-butyl hydroxy peroxide, active ingredient 69%

(Note 4) Slano EX, trade name, Japan Enbello (share) system, preservative

‧Manufacturing Examples 9 to 12 (water-dispersible acrylic resins F2 to F5)

The water-dispersible acrylic resins F2 to F5 were obtained in the same manner as in Production Example 8, except that the monomer compositions of the first and second stages in Production Example 8 were as shown in Table 2.

Table 2 also shows the characteristic values of each water-dispersible acrylic resin.

F6: Ultra-bend E-2500 (trade name, first industrial pharmaceutical (stock) system, water-based polyurethane resin)

F7: Ultra-bend 150 (trade name, first industrial pharmaceutical (stock) system, water-based polyurethane resin)

F8: Superbend 420 (trade name, first industrial pharmaceutical (share) system, waterborne polyurethane resin)

F9: Ultra-bend 300 (trade name, first industrial pharmaceutical (stock) system, water-based polyurethane resin)

F10: Bailuo MD-1100 (trade name, Toyo Textile Co., Ltd., water-based polyester resin)

F11: Aidan Lei EM-0718 (trade name, ADEKA (share), waterborne epoxy resin)

F12: Modanpi 303 (trade name, Arakawa Chemical Industry Co., Ltd., waterborne epoxy resin)

F13: Ouda left S-370 (trade name, Dainippon Ink Chemical Industry Co., Ltd., waterborne epoxy resin)

[decane coupling agent (G)]

G1: KBM-403 (trade name, Shin-Etsu Chemical Co., Ltd., containing glycidyl type)

G2: KBE-403 (trade name, Shin-Etsu Chemical Co., Ltd., containing glycidyl type)

G3: KBE-402 (trade name, Shin-Etsu Chemical Co., Ltd., containing glycidyl type)

G4: KBM-303 (trade name, Shin-Etsu Chemical Co., Ltd., containing glycidyl type)

G5: KBE-903 (trade name, Shin-Etsu Chemical Co., Ltd., containing amine type)

G6: KBM-803 (trade name, Shin-Etsu Chemical Co., Ltd., containing sulfhydryl type)

G7: KBE-585 (trade name, Shin-Etsu Chemical Co., Ltd., containing urea-based type)

G8: KBM-1003 (trade name, Shin-Etsu Chemical Co., Ltd., containing vinyl type)

The base steel sheet of the surface-treated steel sheet was a gold-plated steel sheet shown in Table 1.

After the components (B) to (G) and distilled water are appropriately added to the aqueous liquid (A) containing titanium, the surface treatment composition having a solid content of 2 to 10 mass% and a pH of 8 is applied to the gold-plated steel sheet. After 5 seconds, the surface was dried to a certain drying temperature (up to the plate temperature) to prepare a surface-treated steel sheet. With respect to the obtained surface-treated steel sheet, a rubber roller (48 mm Φ × 205 mm) was used to attach the photocopying paper, and the surface of the coating film was subjected to a wound treatment with a load of 690 g (including the drum self-weight) without rotating the drum, and the test material was obtained. 1. Further, the comparative examples of No. 58 described in Tables 5 and 6 did not perform the above-described tape wound treatment.

With respect to the test materials 1, the heat-resistant discoloration property, the water-resistant adhesion property, the corrosion resistance, and the blackening resistance were evaluated by the following test methods (1) to (4).

Further, a general polyvinyl chloride film was applied to the test material 1 with an adhesive to a dry film thickness of 3 μm, and then heated in a furnace at a furnace temperature of 100 ° C, and then a polyvinyl chloride having a film thickness of 250 μm was rolled by a roller. The film was pressed against the surface of the test material, and an organic resin-coated steel sheet (which is "test material 2") was produced by thermocompression bonding of a polyvinyl chloride film (organic resin layer) with a steel sheet temperature of 230 °C. The test material 2 produced was evaluated for post-processing adhesion, boiling water adhesion, and corrosion resistance by the following test methods (5) to (7).

Further, the storage stability of the surface treatment composition was evaluated by the following test methods (8) and (9).

The above results and the composition of the surface treatment composition applicable to each test material and the coating conditions thereof are shown in Tables 3 to 12.

(1) Heat discoloration

The test material 1 was heated to a plate temperature of 500 ° C for 30 seconds using an infrared ray oven, and after 30 seconds, it was naturally allowed to cool to room temperature to visually observe the surface appearance. The evaluation criteria are as follows.

○: no discoloration

△: The color is light yellow

×: Discoloration is yellow to brown

(2) Water resistance

1 mL of pure water was dropped on the test material 1, and the surface appearance was visually observed by drying in an oven at 100 ° C for 10 minutes. The evaluation criteria are as follows.

◎: no discoloration

○: almost no discoloration

△: only the contour of the drip portion was observed

×: Discoloration of the whole liquid part

(3) Corrosion resistance

Using a test piece of 50 mm × 100 mm cut out from the test material 1 and sealing the end portion and the back surface of the test piece, a salt spray test of JIS-Z-2371-2000 was carried out to measure the area ratio of white rust to 5%. Test time. The evaluation criteria are as follows.

◎: 36 hours or more

○: More than 24 hours, less than 36 hours

△: 12 hours or more, less than 24 hours

×: less than 12 hours

(4) Resistance to blackening

ΔL (L value after test - L value before test) was calculated. The whiteness (L value) of the test material 1 was statically placed in a constant temperature and humidity machine controlled at a temperature of 80 ° C and a relative humidity of 95% for 24 hours. . The evaluation criteria are as follows.

○: ΔL≧-5.0

△: -5.0>ΔL≧-10.0

×:-10.0>ΔL

(5) Adhesiveness after processing (peeling strength after processing)

A test piece of 30 mm × 120 mm cut out from the test material 2 was used, and at the substantially central portion in the longitudinal direction of the test piece, two lines of 50 mm intervals were drawn in a right angle direction with respect to the longitudinal direction, and then a clip of a tensile tester was used. The longitudinal ends of the test piece were sandwiched, and the interval between the two lines was extended to 60 mm in the uniaxial direction. The test piece after the extension was used as a sample, and the organic resin layer between the two lines after the augmentation was set to have a width of 20 mm and a depth of the steel plate. After forcibly peeling one end of the organic resin layer having the cut, the end of the peeled organic resin layer was sandwiched by a clip of one of the tensile testers, and the steel sheet was sandwiched by the other of the tensile tester, and the peeling speed was 50 mm/ The peel test was carried out under the conditions of each. In the peeling test, the organic resin layer was peeled off from the surface of the steel sheet in the direction of 180 degrees (opposite direction), and the maximum strength (=peel strength) at the time of peeling was measured. When the peel strength is large, the organic resin layer is hardly peeled off from the metal sheet, and the adhesion after bending and twisting is excellent. Based on the measured peel strength, the post-processing adhesion was evaluated on the basis of the following criteria.

4 (comment): Peel strength is 50N/20mm or more

3 (comment): Peel strength is 40N/20mm or more, less than 50N/20mm wide

2 (comment): Peel strength is 30N/20mm or more, less than 40N/20mm wide

1 (point): peel strength is less than 30N/20mm wide

(6) Boiling water adhesion (peeling strength after hot water immersion)

A test piece of 30 mm × 120 mm was cut out from the test material 2, and the test piece was immersed in boiling water for 5 hours, and taken out. The peel strength of the organic resin layer of the test piece from the steel sheet was measured in the same manner as in the test of the above (5). When the peel strength is large, the adhesion after hot water immersion, that is, the adhesion in a high-temperature wet environment is excellent. Based on the measured peel strength, the boiling water adhesion was evaluated on the basis of the following criteria.

4 (comment): Peel strength is 50N/20mm or more

3 (comment): Peel strength is 40N/20mm or more, less than 50N/20mm wide

2 (comment): Peel strength is 30N/20mm or more, less than 40N/20mm wide

1 (point): peel strength is less than 30N/20mm wide

(7) Corrosion resistance (resistance to scratch)

A test piece of 50 mm × 100 mm was cut out from the test material 2, and a cross was cut out from the surface of the test piece, and a salt spray test for 1000 hours was carried out in accordance with JIS-Z-2371-2000. The unilateral corrosion width from the cross was measured. The evaluation criteria are as follows.

◎: The average corrosion width of the self-cutting part is less than 5mm

○: The average corrosion width from the cut portion is 5 mm or more, less than 10 mm.

×: The average corrosion width of the self-cutting portion is 10 mm or more

When the film formed on the surface of the surface-treated steel sheet is inferior in damage resistance, the film is cut off to form a wound that reaches most of the gold-plated surface. Since the wound portion does not have a film, it lacks adhesion to the organic resin layer, and water is easily invaded. Therefore, the salt water invaded from the cross will soak the wound for corrosion. As a result, when the resistance to the tape is poor, the corrosion from the cross is wide. The tape damage resistance was evaluated by evaluating the one-sided average corrosion width from the cross.

(8) Storage stability (I)

The surface treatment composition of the solid fraction of 8 mass% was visually evaluated for the precipitation state and viscosity of the solid fraction after 2 weeks at 40 °C. The evaluation criteria are as follows.

◎: The solid content is not precipitated and the viscosity is unchanged.

○: a small amount of solid precipitates or a slight change in viscosity

△: There are more solid precipitates or larger viscosity changes.

×: solid precipitates are more precipitated and the viscosity changes more

(9) Storage stability (II)

The surface treatment composition of the solid fraction of 8 masS% was kept at 30 ° C, and the precipitation state of the solid fraction was visually evaluated every one week. The evaluation criteria are as follows.

◎: No precipitation after 4 weeks

○: precipitation occurred after 4 weeks

△: precipitation occurs after 2 weeks to 3 weeks

×: precipitation occurred after 1 week

The contents of *1 to *10 in Table 3, Table 5, Table 7, Table 9, and Table 11 are as follows.

*1 Gold-plated steel sheets No.1 to No.9 as shown in Table 1.

*2 Titanium-containing aqueous liquids T1 to T7 described in this manual

*3 Zirconium compounds B1 to B3 described in this manual

*4 The organic phosphate compounds C1 and C2 described in this manual

*5 Metal phosphates D1 to D3 described in this manual

*6 Oxide E1 to E4 described in this manual

*7 Water-soluble or water-dispersible organic resins F1 to F13 described in this manual

*8 The decane coupling agents G1 to G8 described in this manual

*9 Surface treatment composition (aqueous treatment liquid) Solid mass in 1 liter (g)

*10 Proportion of the total solid content of the surface treatment composition (aqueous treatment liquid) (mass%)

Claims (7)

A surface treatment composition which is a titanium compound containing at least one selected from the group consisting of a low condensate of a hydrolyzable titanium compound, a hydrolyzable titanium compound, a titanium hydroxide, and a titanium hydroxide. 100 parts by mass of the solid content of the titanium-containing aqueous liquid (A) obtained by mixing hydrogen peroxide water, 10 to 300 parts by mass of the zirconium carbonate compound (B), and 50 to 200 parts by mass of the organic phosphoric acid compound (C), which are still contained The ratio of the total solid content of the surface treatment composition is 2 to 20 mass%, and one or more metal phosphates (D) selected from the aluminum salt, the magnesium salt and the manganese salt of the phosphoric acid are formed on the surface. A water-soluble organic resin and/or a water-dispersible organic resin having a ratio of 20 to 40 mass% of cerium oxide (E) and a total solid content of the surface-treated composition of 2 to 10 mass% in the total solid content of the substance (F), a decane coupling agent (G) in a ratio of 0.5 to 20 mass% to the total solid content of the surface treatment composition. The surface treatment composition of claim 1, wherein the cerium oxide (E) is a gas phase cerium oxide produced by a dry method. The surface treatment composition of claim 2, wherein the gas phase cerium oxide has a bulk specific gravity of 40 g/L or less. The surface treatment composition according to any one of claims 1 to 3, wherein the decane coupling agent (G) has a glycidyl group. The surface treatment composition of claim 1 is pH 7 to 12. A surface-treated steel sheet characterized by coating a surface treatment composition according to any one of claims 1 to 5 on a surface of a galvanized steel sheet or an aluminum-plated steel sheet to have a dried surface The surface-treated film having a film deposition amount of 0.03 to 0.5 g/m ² was formed. An organic resin-coated steel sheet characterized by having an organic resin layer on a surface-treated film of a surface-treated steel sheet according to item 6 of the application of the patent application.