KR100963734B1 - Surface treated steel sheet - Google Patents

Abstract

The surface-treated steel sheet has a surface-treated film containing titanium, nickel, aluminum and fluorine on the surface of the zinc-based plated steel sheet having a thickness of 0.05 to 1.0 µm, and the surface-treated film has a titanium deposition amount of 0.01 to 0.5 g / m 2. Moreover, it contains 0.01-5 mass parts of nickel, 0.1-25 mass parts of aluminum, and 1-500 mass parts of fluorine with respect to 100 mass parts of titanium. This surface-treated steel sheet does not contain any hexavalent chromium in the coating and has excellent heat discoloration resistance, corrosion resistance and blackening resistance.

Zinc-based plated steel sheet, surface treatment composition, aqueous treatment liquid, surface treatment steel sheet, heat discoloration resistance, corrosion resistance, blackening resistance

Description

SURFACE TREATED STEEL SHEET}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treated steel sheet which is very suitable for automobiles, home appliances, and building materials. In particular, the present invention relates to an environmentally compatible display treated steel sheet containing no hexavalent chromium in a surface treated film.

Steel plates for home appliances, steel plates for building materials, and automotive steel sheets are mainly made of chromic acid, dichromic acid or salts thereof for the purpose of improving the corrosion resistance (white-blue and blue-resistance) on the surface of galvanized or aluminum-based galvanized steel. Steel plates subjected to chromate treatment with one treatment liquid are widely used. This chromate treatment is an economical treatment method excellent in corrosion resistance and relatively simple to carry out.

The chromate treatment uses hexavalent chromium, a pollutant restriction material. The hexavalent chromium is treated with a closed system in the treatment process, and chromium from the chromate coating is formed by sealing with an organic coating formed on the upper layer. Since the elution can be made almost zero, the human body and the environment are not contaminated substantially with hexavalent chromium. However, with the recent high interest in global environmental issues, not only the existing regulations on work environment and wastewater treatment but also the regulations on environmental burden and environmental harmony are beginning. There is also a background in the era of evaluating manufacturers as environmental contributions, and there is a growing movement to reduce the use of heavy metals, including hexavalent chromium.

Under such a background, a lot of proposals have been made on the white rust suppression technology (chromate-free technology) of zinc-based galvanized steel sheets which do not use hexavalent chromium. For example, Japanese Patent Application Laid-Open No. 11-350157 and Japanese Patent Laid-Open No. 2000-26980 propose surface treating agents containing Al, phosphoric acid compounds, silica, and aqueous organic resin emulsions and metal materials coated therewith. . In addition, Japanese Laid-Open Patent Publication No. 2000-129460 proposes a zinc-based galvanized steel sheet in which an organic coating layer is formed after forming an amorphous coating by applying and drying a mixed aqueous solution of a polyphosphate first phosphate and a metal oxide sol. . Further, Japanese Patent Application Laid-Open No. 2002-53979 and Japanese Patent Laid-Open No. 2002-53980 disclose composite oxide coating layers containing oxide fine particles, phosphoric acid and / or phosphoric acid compounds, and at least one metal selected from Mg, Mn, and Al. The steel plate which used as a lower layer and formed the organic film in the upper layer is proposed.

In the application to which a zinc-based galvanized steel sheet is applied, there are not many parts to be heated in the temperature range (500-600 degreeC) more than melting | fusing point of zinc. For example, in a heat exchanger in an outdoor unit of an air conditioner, a zinc-based galvanized steel sheet is placed between a copper pipe and an evaporator to prevent dissolution of aluminum by heating using a gas burner when soldering the copper pipe and an evaporator made of aluminum. In order to prevent the burner flame from directly contacting aluminum. When the surface-treated steel sheet of the prior art is applied to such a use, since it is a film of the main body of the organic resin, it is discolored to yellow or dark brown by thermal decomposition, resulting in appearance defects. 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, chromate-free technology excellent in heat discoloration resistance is proposed. For example, Japanese Patent Application Laid-Open No. 2000-79370 and Japanese Patent Laid-Open No. 2001-348672 propose an inorganic rich film mainly composed of first phosphate and colloidal silica. Japanese Laid-Open Patent Publication No. 2004-91826 proposes a two-layer coating in which an inorganic rich film mainly composed of first phosphate and colloidal silica is disposed below, a silicate coating, and / or a silicone resin above.

However, the inorganic rich coatings described in JP-A-2000-79370 and JP-A-2001-348672 have very low corrosion resistance levels and are difficult to apply as a substitute for chromate coatings. On the other hand, the two-layer coating described in Japanese Patent Application Laid-Open No. 2004-91826 is a corrosion resistance level applicable as a chromate coating replacement, but there is a problem in terms of cost because it uses expensive silicate or silicone resin. In addition, since the coating by these techniques tends to turn black in a wet environment (black side), it is difficult to apply in a heat exchanger that is easy to condensate. no.

Accordingly, an object of the present invention is to solve the problems of the prior art, and to provide a surface-treated steel sheet which does not contain hexavalent chromium in the surface-treated coating and has excellent heat discoloration resistance, corrosion resistance and blackening resistance.

In an embodiment of the present invention, the surface of the zinc-based plated steel sheet has a surface treatment film containing titanium, nickel, aluminum, and fluorine having a thickness of 0.03 to 1.0 μm, and the surface treatment film has a titanium adhesion amount of 0.03 to 0.3 g / m 2 and 0.05 to 1.5 parts by mass of nickel, 0.5 to 10 parts by mass of aluminum, and 10 to 400 parts by mass of fluorine based on 100 parts by mass of titanium; The mass ratio of nickel and aluminum contained in the surface treatment film is in the range of 1: 5 to 1:25; The surface-treated coating film further contains 30 to 1000 parts by mass of zirconium, 10 to 200 parts by mass of phosphorus and 5 to 300 parts by mass of vanadium with respect to 100 parts by mass of titanium.

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In another embodiment of the present invention, on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet, a low-condensation product of a hydrolyzable titanium compound, a hydrolyzable titanium compound, a titanium hydroxide, and a low-condensation product of titanium hydroxide is selected. 0.01 to 10 parts by mass of a nickel compound, 5 to 30 parts by mass of an aluminum compound, and 50 parts by weight of a titanium-containing aqueous solution obtained by mixing at least one titanium compound with hydrogen peroxide solution, and 100 parts by mass of the solid content of the titanium-containing aqueous solution. A coating treatment amount of 0.1 to 2.0 g / m 2 formed by applying and drying a surface treatment composition containing ˜500 parts by mass of a fluorine-containing compound; The compounding ratio of the nickel compound and the aluminum compound is in the range of 1: 5 to 1:50; The fluorine-containing compound is at least one member selected from the group consisting of ammonium zircon fluoride and zircon fluoric acid; The surface treatment composition contains 20 to 300 parts by mass of an organic phosphate compound, 10 to 400 parts by mass of vanadate acid compound, and 10 to 400 parts by mass of zirconium carbonate compound with respect to 100 parts by mass of the solid content of the titanium-containing aqueous solution; The surface treatment composition provides at least one resin selected from the group consisting of a water-soluble organic resin and a water-dispersible organic resin, based on 100 parts by mass of the solid content of the titanium-containing aqueous liquid. .

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Therefore, the surface-treated steel sheet of the present invention is mainly composed of an inorganic component that does not accompany color development or discoloration by heating, and thus is excellent in heat discoloration resistance, and a chromate coating is formed because the inorganic component has a high barrier property. It has excellent corrosion resistance and blackening resistance comparable to the surface treated steel sheet having.

Embodiment 1

The present inventors examine the film composition which can solve the above problems, and as a result, by forming a surface treatment film containing titanium, nickel, aluminum and fluorine on the surface of the zinc-based plated steel sheet, excellent heat discoloration resistance, corrosion resistance, It was found that a surface treated steel sheet having a processed portion corrosion resistance and blackening resistance was obtained.

Examples of the zinc-based plated steel sheet serving as the base of the surface-treated steel sheet of the present invention include, for example, galvanized steel sheet, Zn-Ni alloy plated steel sheet, Zn-Fe alloy plated steel sheet (electroplated steel sheet, alloyed hot dip galvanized steel sheet), and 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-5mass% Al alloy plated steel sheet, Zn-55mass% Al alloy plated steel sheet), Zn-Mg alloy plated steel sheet, Zn-Al-Mg alloy plated steel sheet, and also in the plating film of these plated steel sheets Zinc-based composite plated steel sheets (eg, Zn-SiO ₂ dispersed plated steel sheets) in which metal oxides, polymers, etc. are dispersed may be used. Moreover, the multilayer plating steel plate which plated two or more layers of the same kind or a different kind among the above platings can also be used.

In addition, the plated steel sheet may be coated with thin coating of Ni or the like on the steel sheet surface in advance, and various platings as described above may be performed thereon.

As the plating method, any one of electrolytic methods (electrolysis in aqueous solution or electrolysis in non-aqueous solvent), melting method, and vapor phase method can be adopted.

In order to prevent coating defects or stains from occurring when the surface treated film is formed on the surface of the coated film, alkali degreasing, solvent degreasing, and surface adjustment treatment (alkaline surface adjustment treatment or acidic surface treatment) are performed on the surface of the coating film in advance as necessary. And other processing).

In addition, in order to prevent black stools (a type of oxidation phenomenon on the surface of plating) under the use environment, iron-plated metal ions (one or more of Ni ions, Co ions, and Fe ions) may be included in the plating surface in advance if necessary. Surface adjustment treatment with an acidic or alkaline aqueous solution may be performed.

In the case of using an electrogalvanized steel sheet as a base steel sheet, iron group metal ions (one or more of Ni ions, Co ions, and Fe ions) are added to the electroplating bath for the purpose of preventing black stools. 1 mass ppm or more of metals can be contained. In this case, the upper limit of the iron group metal concentration in the plating film is not particularly limited.

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 is a film containing a predetermined amount of titanium (Ti), nickel (Ni), aluminum (Al) and fluorine (F). This surface treatment coating does not contain hexavalent chromium.

Titanium (Ti) can be contained in a film by apply | coating the aqueous solution containing a titanium compound to a plated steel plate, and drying or heat-processing at low temperature. Thus, by using the aqueous liquid containing a titanium compound, the titanium oxide containing film which is compact, excellent in adhesiveness, and corrosion resistance and barrier property can be formed. Moreover, as heat processing temperature after apply | coating the aqueous liquid containing a titanium compound, 200 degrees C or less, especially 150 degrees C or less are preferable. Titanium adhesion amount in a surface treatment film is 0.01-0.5g / m <2>, Preferably it is 0.03-0.3g / m <2>. If the titanium deposition amount is less than 0.01 g / m 2, it is difficult to closely coat the entire surface of the plated steel sheet, and the corrosion resistance, in particular, the corrosion resistance of the processed portion is poor. On the other hand, when the titanium deposition amount exceeds 0.5 g / m 2, film peeling is likely to occur during steel sheet processing due to internal film stress.

Nickel (Ni) is an effective component for improving blackening resistance and can be contained in a film by adding a nickel compound to the aqueous solution containing the titanium compound. The nickel content in the surface-treated film is 0.01 to 5 parts by mass, preferably 0.05 to 1.5 parts by mass with respect to 100 parts by mass of titanium. When the nickel content is less than 0.01 parts by mass with respect to 100 parts by mass of titanium, the black side is improved. If the effect of is not obtained sufficiently and exceeds 5 parts by mass, the black side is sufficiently improved, but the deterioration of corrosion resistance is remarkable.

Aluminum (Al) is an effective component for improving the corrosion resistance and can be contained in the film by adding an aluminum compound to the aqueous solution containing the titanium compound. The content of aluminum in the surface treatment film is 0.1 to 25 parts by mass, preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of titanium. If the aluminum content is less than 0.1 part by mass with respect to 100 parts by mass of titanium, the improvement of the corrosion resistance is insufficient. On the other hand, the corrosion resistance deteriorates with an excessive amount of addition exceeding 25 parts by mass. It is considered that this is because the barrier coating made of titanium oxide cannot be formed properly.

In particular, from the viewpoint of achieving both blackening resistance and corrosion resistance, it is preferable that the mass ratio of nickel and aluminum contained in the surface-treated film is in the range of 1: 1 to 1:50, preferably in the range of 1: 5 to 1:25. Do.

Fluorine (F) is an effective component for improving the corrosion resistance, in particular, the corrosion resistance of the processed part and the water-resistant discoloration resistance. The fluorine (F) can be contained in the film by adding the fluorine-containing compound to the aqueous solution containing the titanium compound. Content of fluorine (F) in a surface treatment film is 1-500 mass parts with respect to 100 mass parts of titanium, Preferably it is 10-400 mass parts. If the fluorine content is less than 1 part by mass with respect to 100 parts by mass of titanium, the effect of improving the corrosion resistance is not observed. On the other hand, if the content of the fluorine exceeds 500 parts by mass, the effect of improving the corrosion resistance is not only saturated but also inhibits the effect of nickel present for blackening resistance.

The surface treatment film may further contain at least one of zirconium, phosphorus and vanadium.

Zirconium (Zr) is an effective component for improving the corrosion resistance after alkali degreasing and can be contained in the film by adding a zirconium compound to the aqueous solution containing the titanium compound. The content of zirconium in the surface treatment film is preferably 2 to 1000 parts by mass, preferably 30 to 1000 parts by mass with respect to 100 parts by mass of titanium. When the zirconium content is less than 2 parts by mass with respect to 100 parts by mass of titanium, the effect of adding zirconium is not sufficiently obtained. On the other hand, when the excess amount exceeds 1000 parts by mass, the effect of improving the corrosion resistance after alkali degreasing may be saturated. It also inhibits the effects of titanium.

Phosphorus (P) is a component effective for improving the storage stability of the aqueous solution containing the titanium compound, and can be contained in the film by adding a phosphorus-containing compound to the same aqueous solution. The content of phosphorus in the surface-treated coating film is suitably 1 to 300 parts by mass, preferably 10 to 200 parts by mass with respect to 100 parts by mass of titanium. When phosphorus content is less than 1 mass part with respect to 100 mass parts of titanium, the effect by adding phosphorus is not fully acquired, On the other hand, in excess addition amount exceeding 300 mass parts, the effect of phosphorus not only saturates but the effect of titanium Inhibits.

Vanadium (V) slightly deteriorates heat discoloration resistance, but is an effective component for improving water-resistant discoloration resistance, and can be contained in a film by adding a vanadium compound to an aqueous solution containing the titanium compound. The content of vanadium in the surface treatment film is preferably 1 to 300 parts by mass, preferably 5 to 300 parts by mass with respect to 100 parts by mass of titanium. If the vanadium content is less than 1 part by mass with respect to 100 parts by mass of titanium, the effect of adding vanadium is not sufficiently obtained. On the other hand, the excess effect of vanadium not only saturates at an excessive amount of addition of more than 300 parts by mass, but also the effect of titanium. Inhibits.

Component analysis of the surface treatment film as mentioned above can be performed by the following methods, for example. First, about titanium, zirconium, phosphorus, vanadium, and nickel, the film area is coated with concentrated sulfuric acid on the surface of a known surface-treated steel sheet, dissolved in each plating layer, washed with distilled water, collected and poured into a Kjeldahl flask for acid decomposition. In addition, concentrated hydrochloric acid may be added to dissolve all of the undissolved lysates and analyzed by the calibration curve method using ICP spectroscopic analysis apparatus. Fluorine can be quantified from a calibration curve made of a concentration known fluorine compound using a wavelength dispersion fluorescence X-ray analyzer. About aluminum, the difference of the analysis value by ICP of the acid decomposition liquid melt | dissolved for every plating layer and the acid decomposition liquid which melt | dissolved only the plating layer as above is made into the amount of aluminum in a film.

The surface treatment film of the present invention as described above can be obtained by applying an aqueous treatment liquid (surface treatment composition) to the surface of a plated steel sheet, and drying or heating and calcining. Each coating component is applied to the following treatment liquid components. Is preferably supplied. Titanium is supplied from an aqueous solution (A) containing titanium obtained by mixing at least one titanium compound selected from a hydrolyzable titanium compound, a low-condensation product of a hydrolyzable titanium compound, a titanium hydroxide, and a low-condensation product of titanium hydroxide and a hydrogen peroxide solution. do.

The hydrolyzable titanium compound is a titanium compound having a hydrolyzable group which directly bonds to titanium, and generates titanium hydroxide by reacting with water such as water and water vapor. In the hydrolyzable titanium compound, all of the groups bonded to titanium may be hydrolyzable or some of the groups bonded to titanium may be hydrolyzable.

The hydrolyzable group is not particularly limited as long as it forms titanium hydroxide by reacting with water as described above. Examples thereof include a lower alkoxyl group and a group forming a salt with titanium (for example, halogen atoms such as chlorine, hydrogen, etc.). Atoms, sulfate ions, and the like).

As the hydrolyzable titanium compound containing a lower alkoxyl group as the hydrolyzable group, tetraalkoxy titanium represented by the general formula Ti (OR) ₄ (wherein R represents the same or different alkyl group having 1 to 5 carbon atoms) is preferable. Do. Examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and the like.

As the hydrolyzable group, examples of the hydrolyzable titanium compound having a group which forms a salt with titanium include titanium chloride and titanium sulfate.

The low condensate of the hydrolyzable titanium compound is a low condensate of the above hydrolyzable titanium compounds. In this low-condensate, all of the groups bonded to titanium may be hydrolyzable or some of the groups bonded to titanium may be hydrolyzable.

For hydrolyzable titanium compounds (eg, titanium chloride, titanium sulfate, etc.) in which the hydrolyzable groups form salts with titanium, ortho titanic acid obtained by the reaction of an aqueous solution of the hydrolyzable titanium compound and an alkaline 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 titanium hydroxide, a compound having a condensation degree of 2 to 30 can be used, and it is particularly preferable to use a compound having a condensation degree of 2 to 10. If the degree of condensation exceeds 30, white precipitates occur when mixed with hydrogen peroxide, and a stable titanium-containing aqueous solution cannot be obtained.

Examples of the hydrolyzable titanium compound, the low-condensation product of the hydrolyzable titanium compound, the titanium hydroxide, and the low-condensation product of the titanium hydroxide may be used alone or in combination of two or more thereof. Among them, the hydrolyzable titanium compound represented by the above-described general formula Phosphorus tetraalkoxy titanium is particularly preferred.

As the titanium-containing aqueous solution (A), any conventionally known one can be used without particular limitation as long as it is an aqueous solution containing titanium obtained by mixing the above-described titanium compound and hydrogen peroxide solution. Specifically, the following are mentioned.

(Iii) A titanyl ion hydrogen peroxide complex or titanic acid (peroxotitahydrate) solution obtained by adding hydrogen peroxide to a gel or sol of hydrous titanium oxide (JP-A-63-35419, Japanese Patent Laid-Open No. 224220).

(Ii) Titania film-forming liquid obtained by reacting hydrogen peroxide solution with titanium hydroxide gel prepared from an aqueous solution of titanium chloride or titanium sulfate and a basic solution and synthesizing it (Japanese Patent Application Laid-Open No. 9-71418, Japanese Patent Laid-Open No. 10-67516).

In obtaining such a liquid for forming a tatania film, a titanium hydroxide gel called ortho titanic acid is precipitated by reacting an aqueous solution of titanium chloride or titanium sulfate with an alkaline solution such as ammonia or caustic soda. Subsequently, the separation and washing of the titanium hydroxide gel are repeated by decantation, and further, hydrogen peroxide is added and the excess hydrogen peroxide is decomposed and removed to obtain a yellow transparent viscous liquid.

The ortho titanic acid precipitated is in a kel state polymerized by polymerization or hydrogen bonding of OHs, and cannot be used as it is as an aqueous liquid containing titanium. When hydrogen peroxide is added to this gel, part of the OH becomes peroxidated and dissolved as peroxotitanate ions, or the polymer chain is cut to low molecular weight to form a kind of sol, and the excess hydrogen peroxide is decomposed into water and oxygen. It can be used as an aqueous liquid containing titanium for inorganic film formation.

Since these sols contain only oxygen atoms and hydrogen atoms other than titanium atoms, when converted to titanium oxide by drying or calcining, only sol and water are generated. No removal is required, and a titanium oxide film having a relatively high density can be formed even at a low temperature.

(Iii) adding peroxide to an aqueous solution of inorganic titanium compounds such as titanium chloride or titanium sulfate to form peroxotitahydrate, and then leaving the solution obtained by adding a basic substance to produce a precipitate of peroxotitahydrate polymer, Subsequently, a solution for forming titanium oxide obtained by removing at least a dissolved component other than water derived from a titanium-containing raw material solution and then reacting with hydrogen peroxide (see Japanese Patent Laid-Open Nos. 2000-247638 and 2000-247639).

The titanium-containing aqueous solution (A) using a hydrolyzable titanium compound and / or its low condensate (hereinafter referred to as &quot; hydrolyzable titanium compound a &quot; for the purpose of explanation) as a titanium compound is used to react the hydrolyzable titanium compound a with hydrogen peroxide solution and reaction temperature. It can obtain by making it react for 10 to 20 hours at 1-70 degreeC.

The titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a reacts with the hydrolyzable titanium compound a and hydrogen peroxide to hydrolyze the hydrolyzable titanium compound a to form a hydroxyl group-containing titanium compound. Subsequently, hydrogen peroxide is thought to coordinate with this hydroxyl-containing titanium compound, and this hydrolysis reaction and hydrogen peroxide coordination have occurred almost simultaneously, resulting in a chelating solution having a very high stability in the room temperature region and long-term preservation of organs. Create The titanium hydroxide gel used in the conventional manufacturing process is partially three-dimensionalized by Ti-O-Ti bonding, and its composition and stability are substantially different from those of the titanium-containing aqueous solution (A) in which the gel and the hydrogen peroxide solution are reacted. .

When the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a is subjected to heat treatment or autoclave treatment at 80 ° C. or higher, a titanium oxide dispersion liquid containing ultrafine particles of crystallized titanium oxide is obtained. If the heat treatment or autoclave treatment is less than 80 ° C, crystallization of titanium oxide does not proceed sufficiently. The titanium oxide dispersion prepared as described above has an average particle diameter of the titanium oxide ultrafine particles of 10 nm or less, preferably about 1 to 6 nm. When the average particle diameter of the ultrafine titanium oxide fine particles is larger than 10 nm, the film forming property is lowered (when the film is dried after coating and formed into a film, cracking occurs at a film thickness of 1 µm or more). The external appearance of this titanium oxide dispersion liquid has a translucent shape. Such a titanium oxide dispersion liquid can also be used as a titanium-containing aqueous liquid (A).

Aqueous treatment solution (also called surface treatment composition) containing a titanium-containing aqueous solution (A) using a hydrolyzable titanium compound a is applied to itself by coating and drying (for example, heat drying at low temperature) on the surface of a plated steel sheet. It is possible to form a dense titanium oxide-containing film (surface treatment film) with excellent properties.

As a heating temperature after apply | coating an aqueous process liquid, 200 degrees C or less, especially 150 degrees C or less are preferable, and the amorphous (amorphous) titanium oxide containing film containing some hydroxyl groups is formed by heat-drying at such temperature, for example. can do.

In addition, when the titanium oxide dispersion obtained through the above heat treatment or autoclave treatment as described above is used as the titanium-containing aqueous solution (A), a crystalline titanium oxide-containing film can be formed only by applying the aqueous treatment solution. It is useful as a coating material of a material that cannot be heat treated because of its presence.

As the titanium-containing aqueous solution (A), a titanium-containing aqueous solution (A1) obtained by reacting a 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 (you may add, for example, an aqueous organic solvent such as alcohol or alcohol ether). As this titanium oxide sol, a conventionally well-known thing can be used, For example, (i) Titanium oxide aggregate obtained by hydrolyzing titanium solution, such as titanium sulfate and titanium sulfate, (ii) Organic titanium compounds, such as titanium alkoxide An amorphous titania sol obtained by dispersing a titanium oxide aggregate such as a titanium oxide aggregate obtained by hydrolysis, a titanium oxide aggregate obtained by hydrolysis or neutralizing a titanium halide solution such as titanium tetrachloride or the like, or the titanium oxide aggregate It is possible to use a sol which is calcined to make anatase titanium fine particles and dispersed in water.

In the firing of the amorphous titania, the amorphous titania can be converted into anatase-type titania by firing at a temperature of at least the crystallization temperature of the anatase, for example, 400 ° C to 500 ° C or higher. Examples of the aqueous sol of titanium oxide include TKS-201 (trade name, manufactured by Tayca Co., Ltd., anatase crystal form, average particle diameter 6 nm), TA-15 (trade name, manufactured by Nissan Chemical Company, Ana TAS type | mold crystal form), STS-11 (brand name, Ishihara Industrial Co., Ltd., anatas type crystal form), etc. are mentioned.

In the titanium-containing aqueous solution (A1), the mass ratio (x / y) of the titanium oxide sol (x) and the titanium peroxide reactant (y) (the reaction product of the hydrolyzable titanium compound a and the hydrogen peroxide solution) is 1/99 to 99/1, preferably in the range of 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 is not sufficiently obtained in terms of stability and photoreactivity. .

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

The production form and characteristics of the titanium-containing aqueous solution (A1) are the same as those of the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a described above. (I) is suppressed. The reason for this is considered that the condensation reactant is adsorbed on the surface of the titanium oxide sol and the polymerization in solution is suppressed.

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

Similarly to the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a described above, an aqueous treatment liquid (surface treatment composition) containing the titanium-containing aqueous solution (A1) is applied and dried (for example, Heat drying at a low temperature) can form a dense titanium oxide-containing film (surface treatment film) that is excellent in adhesion.

As a heating temperature after apply | coating an aqueous process liquid, 200 degrees C or less, especially 150 degrees C or less are preferable, and the anatase-type titanium oxide containing film containing some hydroxyl groups can be formed by heat-drying at such temperature, for example. have.

As described above, among the titanium-containing aqueous solutions (A), the titanium-containing aqueous solution (A) and the titanium-containing aqueous solution (A1) using the hydrolyzable titanium compound a have excellent performances in storage stability, corrosion resistance, and the like. Particular preference is given to using these.

The blending ratio of hydrogen peroxide to at least one titanium compound selected from hydrolyzable titanium compounds, low-condensates of hydrolyzable titanium compounds, titanium hydroxide and titanium hydroxide is in terms of hydrogen peroxide relative to 10 parts by mass of the titanium compound. It is preferable to set it as 0.1-100 mass parts, Preferably it is 1-20 mass parts. When the compounding ratio of the hydrogen peroxide water is less than 0.1 parts by mass in terms of hydrogen peroxide, chelating formation is insufficient, so that a cloudy precipitate occurs. On the other hand, if it exceeds 100 parts by mass, unreacted hydrogen peroxide tends to remain and releases dangerous free radicals during storage, which is not preferable.

The hydrogen peroxide concentration of the hydrogen peroxide water is not particularly limited, but it is preferable that it is about 3 to 30% by mass because the solid content concentration of the production liquid related to coating workability is appropriate.

In the titanium-containing aqueous solution (A), other sol or pigment may be added and dispersed as necessary. For example, commercially available titanium oxide sol, titanium oxide powder, mica, talc, silica, baryta, clay and the like can be added. can do.

The content of the titanium-containing aqueous liquid (A) in the aqueous treatment liquid (surface treatment composition) is preferably 1 to 100 g / L, preferably 5 to 50 g / L, in terms of solid content, in view of the stability of the treatment liquid. .

Nickel can be contained in a film by adding 1 type, or 2 or more types of nickel acetate, nickel nitrate, a nickel sulfate, etc. to an aqueous treatment liquid, for example. Among them, nickel acetate is very suitable in terms of blackening resistance.

Aluminum can be contained in a film by adding 1 type, or 2 or more types, such as aluminum nitrate, aluminum acetate, aluminum sulfate, aluminum oxide, aluminum acetylacetonate, an aluminate, to aqueous treatment liquid, for example.

Fluorine can be contained in a film by adding 1 type, or 2 or more types, such as ammonium zircon fluoride, potassium zircon fluoride, a zirconic hydrofluoric acid, ammonium titanium fluoride, hydrofluoric acid, ammonium hydrofluoride, to an aqueous treatment liquid. Among them, at least one of ammonium zircon fluoride and zircon hydrofluoric acid is very suitable. That is, ammonium zirconium fluoride is preferable in terms of corrosion resistance after alkali degreasing and water-resistant discoloration, and hydrogen zircon fluoride in terms of corrosion resistance after alkali degreasing.

It is preferable to contain phosphorus in a film by adding an organophosphate compound to an aqueous treatment liquid. Examples of the organophosphate compound include 1-hydroxymethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxypropane-1,1-diphosphonic acid, and the like. Hydroxyl group-containing organic phosphoric acid; Carboxyl group-containing organophosphorous acids such as 2-hydroxyphosphonoacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and salts thereof are mentioned as very suitable ones, and one or two or more of them are mentioned. Can be used. Among them, the effect of 1-hydroxyethane-1,1-diphosphonic acid is great and particularly preferable.

Vanadium is formed by, for example, adding one or two or more kinds of lithium metavanadate, potassium metavanadate, sodium metavanadate, ammonium metavanadate, and vanadate anhydride to an aqueous treatment liquid. It can be contained in the stomach. Especially, ammonium metavanadate is preferable at the point of water-resistant discoloration resistance.

Zirconium can be added to a film by adding 1 type, or 2 or more types of salts, such as sodium, potassium, lithium, and ammonium, of zirconium carbonate to aqueous treatment liquid. Among them, zirconium ammonium carbonate is preferred in view of water resistance discoloration resistance and the like.

In addition, the surface treatment film of the present invention may contain an organic resin component for improving corrosion resistance. In order to contain an organic resin component in a film, it is good to add a water-soluble organic resin and / or a water-dispersible organic resin to an aqueous processing liquid.

The water-soluble organic resin and / or water-dispersible organic resin is an organic resin that can be dissolved or dispersed in water, and a conventionally known method can be applied as a method of accepting or water-oxidizing the organic resin. Specifically, the organic resin contains a functional group (eg, a hydroxyl group, a polyoxyalkylene group, a carboxyl group, an amino (imino) group, a sulfide group, a phosphine group, etc.) capable of being solubilized or water-oxidized alone, And amine compounds such as ethanolamine, triethylamine, etc. as long as some or all of these functional groups are acidic resins (carboxyl group-containing resins, etc.) if necessary; ammonia; If neutralized with alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, and basic resin (amino-group containing resin etc.), Fatty acids, such as acetic acid and lactic acid; What was neutralized with inorganic acids, such as phosphoric acid, etc. can be used.

As the water-soluble or water-dispersible organic resin, for example, epoxy resin, phenol resin, acrylic resin, urethane resin, olefin-carboxylic acid resin, nylon resin, resin having polyoxyalkylene chain, polyvinyl alcohol, poly Glycerin, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, etc. are mentioned, These 1 type, or 2 or more types can be used.

The surface treatment film (or the aqueous treatment liquid for film formation) may further be, for example, a silane coupling agent, a resin fine particle, a heavy metal compound other than the component of the present invention, a thickener, a surfactant, and a lubricating agent (polyethylene). Waxes, fluorine waxes, carnauba wax and the like), rust preventive agents, coloring pigments, extender pigments, rust preventive pigments, dyes and the like. The film thickness of the surface treated film is 0.05 to 1.0 mu m, preferably 0.10 to 0.70 mu m, and more preferably 0.15 to 0.50 mu m. If the film thickness is less than 0.05 µm, the corrosion resistance, the corrosion resistance of the processed portion and the corrosion resistance after alkali degreasing are inferior, while if it exceeds 1.0 µm, the heat discoloration resistance, the corrosion resistance, the corrosion resistance of the processed portion, the corrosion resistance and the water discoloration resistance after alkali degreasing are inferior.

In order to manufacture the surface-treated steel sheet of this invention, after apply | coating the aqueous treatment liquid mentioned above to the surface of a zinc-based galvanized steel sheet, what is necessary is just to dry or heat baking.

The coating method of an aqueous treatment liquid is arbitrary, for example, spray + roll compression, a roll coater, etc., and also the drying method after application | coating is arbitrary, for example, a hot air system, an induction heating system, an electric furnace system.

It is preferable that the drying temperature (steel plate temperature) of the apply | coated aqueous treatment liquid shall be about 60-200 degreeC. If the drying temperature is less than 60 ° C, the film formation becomes insufficient, resulting in a film having poor corrosion resistance and the like. On the other hand, even if it dries at the plate temperature exceeding 200 degreeC, the improvement effect of corrosion resistance corresponding to a drying temperature is not acquired, but corrosion resistance may fall on the contrary. It is considered that this is because cracks are generated in the film due to heat.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example  One

The titanium-containing aqueous liquid (A) and components (B) to (G) used in the aqueous treatment liquid (surface treatment composition) for film formation are shown below.

[Production of titanium-containing aqueous liquid (A)]

Preparation Example 1 (titanium-containing aqueous solution (T1))

Ammonia water (1: 9) was dripped at the solution which made 5 mm of titanium tetrachloride 60 mass% solutions into 500 mm of distilled water, and titanium hydroxide was precipitated. After washing with distilled water, 10 masses of a 30% by mass solution of hydrogen peroxide solution were added to the mixture, followed by stirring to obtain a yellow translucent, viscous titanium-containing aqueous solution (T1).

Preparation Example 2 (titanium-containing aqueous solution (T2))

A mixture of 10 parts by mass of tetraiso-propoxycitane and 10 parts by mass of iso-propanol was added dropwise with stirring at 20 ° C. over 1 hour in a mixture of 100 parts by mass of 30% by mass of hydrogen peroxide solution and 100 parts by mass of deionized water. Then, it aged at 25 degreeC for 2 hours, and obtained the yellow transparent slightly viscous titanium-containing aqueous liquid (T2).

Nickel Compound (B)

B1: nickel acetate

B2: nickel nitrate

[Aluminum Compound (C)]

C1: aluminum nitrate

C2: aluminum acetate

[Fluorine-containing compound (D)]

D1: zircon ammonium fluoride

D2: hydrofluoric acid

Organic Phosphate Compounds (E)

E1: 1-hydroxyethane-1,1-diphosphonic acid

[Vanadic Acid Compound (F)]

F1: ammonium metavanadate

F2: Sodium Metavanadate

[Zirconium Carbonate Compound (G)]

G1: zirconium ammonium carbonate

G2: Sodium Zirconium Carbonate

As the base steel sheet of the carbonated steel sheet, a plated steel sheet shown in Table 1 was used.

The aqueous treatment liquid (surface treatment composition) in which the above-described titanium-containing aqueous liquid (A) and components (B) to (G) were appropriately blended was applied to the surface of the plated steel sheet, and dried after 3 seconds so that the highest reaching plate temperature was 100 ° C. It was made into the test material. These test materials were evaluated for the analysis and performance evaluation (heat discoloration resistance, corrosion resistance, corrosion resistance of the processed portion, corrosion resistance after alkali degreasing, blackening resistance, and water-resistant discoloration resistance) of the coating components by the following method.

The results are shown in Tables 2 to 5 together with the film composition of each test material and the additive components of the aqueous treatment liquid.

[Film analysis method]

The component analysis of the surface treatment film was performed as follows.

For titanium, zirconium, phosphorus, vanadium and nickel, the film area is coated with concentrated sulfuric acid on the surface of the known surface-treated steel sheet and dissolved for each plating layer.Then, it is washed with distilled water, collected and poured into a Kjeldahl flask to perform acid decomposition. All the undissolved lysates were added and analyzed by the calibration curve method using ICP spectroscopic analysis. Fluorine was quantified from a calibration curve made of a concentration known fluorine compound using a wavelength dispersion fluorescence X-ray analyzer. In addition, about aluminum, the difference of the analysis value by the ICP of the acid decomposition liquid melt | dissolved for every plating layer and the acid decomposition liquid which melt | dissolved only the plating layer was made into the amount of aluminum in a film as mentioned above.

[Performance Evaluation Method]

(1) heat discoloration resistance

The test material was heated to a pan temperature of 500 ° C. for 30 seconds in an infrared image furnace, and kept for 30 seconds, and then visually observed the surface appearance when naturally cooled to room temperature. The evaluation criteria are as follows.

◎: no discoloration

○: slightly discolored

△: discoloration to pale yellow

X: discoloration to yellow to multicolored

(2) corrosion resistance

A test material (50 mm x 150 mm) sealed at the end and the back side is provided to the salt spray test based on the neutral salt spray test method of JIS-Z-2371-2000, and the test time at which the white rust generation area ratio becomes 5% Measured. The evaluation criteria are as follows.

◎: 120 hours or more

○: more than 96 hours, less than 120 hours

△: 48 hours or more, less than 96 hours

×: less than 48 hours

(3) Machining part corrosion resistance

About the test material (50 mm x 100 mm) which sealed the edge part and the back surface, after carrying out 180 degree bending by 2.5 mmR with the test surface outside, the neutral salt spray test method of JIS-Z-2371-2000 It used for the salt spray test according to the test, and the test time which becomes 5% of white rust incidence in the width direction 50mm length of the bending tip part was measured. The evaluation criteria are as follows.

◎: more than 96 hours

○: 48 hours or more, less than 96 hours

△: more than 24 hours, less than 48 hours

×: less than 24 hours

(4) corrosion resistance after alkali degreasing

After dissolving alkali degreasing agent "CLN-364S" (made by Nippon Parkarizing Co., Ltd.) at a concentration of 2% by mass in pure water and warming it to 60 ° C, it was sprayed on a test material (50 mm x 150 mm) for 2 minutes, The end part and the back surface were sealed, and it used for the salt spray test based on the neutral salt spray test method of JIS-Z-2371-2000, and the test time which white-blue generation area ratio becomes 5% was measured. The evaluation criteria are as follows.

◎: more than 96 hours

○: 48 hours or more, less than 96 hours

△: more than 24 hours, less than 48 hours

×: less than 24 hours

(5) blackening resistance

Change in whiteness (L value) (ΔL: L value after the test-L value before the test) when the specimen was left standing for 24 hours in a constant temperature and humidity chamber controlled at a temperature of 80 ° C. and a relative humidity of 95%. Saved. The evaluation criteria are as follows.

○: ΔL ≥ -5.0

Δ: -5.0> ΔL ≥ -10.0

×: -10.0> ΔL

(6) Waterproofing discoloration

Ten drops of ion-exchange water were dripped at the test material (50 mm x 50 mm) at about the same point, and it dried in the oven heated at 100 degreeC for 10 minutes, and visually judged by the appearance immediately after drying.

The evaluation criteria are as follows. The photograph of the sample plate used as the reference | standard of "(triangle | delta)" and "x" is shown in FIG.

○: no discoloration

△: slightly discolored

×: discoloration

In Table 2 and Table 4, * 1 to * 8 represent the following contents.

* 1 Plated steel sheets No. 1 to 5 listed in Table 1

* 2 Titanium-containing aqueous solutions T1 and T2 described in the main body of the specification

* 3 Nickel compounds B1 and B2 described in the text of the specification

* 4 Aluminum compounds C1 and C2 described in the text of the specification.

* 5 Fluorine-containing compounds D1 and D2 described in the text of the specification

* 6 Organophosphate compound E1 described in the text of the specification.

* 7 Banadinic acid compounds F1 and F2 described in the text of the specification.

* 8 Zirconium carbonate compounds G1 and G2 described in the text of the specification

Embodiment 2

MEANS TO SOLVE THE PROBLEM The present inventors examined the film composition which can solve the said subject, and, as a result, a nickel compound, an aluminum compound, and fluorine-containing water are contained with respect to the specific titanium-containing aqueous solution on the surface of a zinc-based plated steel plate or an aluminum-based plated steel sheet. Excellent corrosion resistance by forming a surface treatment film by using a surface treatment composition in which a compound is added in a predetermined ratio, and an organic phosphoric acid compound, vanadate acid compound, zirconium carbonate compound, and an aqueous organic resin are appropriately added as necessary. It was found that a surface treated steel sheet having heat discoloration resistance and blackening modification was obtained.

The surface-treated steel sheet of the present invention has at least one titanium compound selected from the group consisting of hydrolyzable titanium compounds, low-condensates of hydrolyzable titanium compounds, low-condensates of titanium hydroxide and titanium hydroxide on the surface of zinc-based galvanized steel or aluminum-based galvanized steel. The titanium-containing aqueous solution (A) obtained by mixing with hydrogen peroxide solution, a nickel compound (B), an aluminum compound (C), and a fluorine-containing compound (D) are blended in a predetermined ratio, and further necessary. According to the present invention, at least one selected from the group consisting of an organic phosphate compound (E), a vanadate compound (F), a zirconium carbonate compound (G), a water-soluble organic resin (H) and a water-dispersible organic resin (H) The surface treatment composition (I) blended in proportion is applied and dried to have a surface treatment coating film having a predetermined coating amount formed by drying. This surface treatment coating does not contain hexavalent chromium.

As a zinc-based galvanized steel sheet used as the base of the surface-treated steel sheet of this invention, a galvanized steel sheet, Zn-Ni alloy-plated steel sheet, Zn-Fe alloy-plated steel sheet (electroplated steel plate, alloying hot dip galvanized 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 sheet (for example, Zn-5mass% Al alloy plated steel sheet, Zn-55mass% Al alloy plated steel sheet), Zn-Mg alloy plated steel sheet, Zn-Al-Mg alloy plated steel sheet, or metal in the plating film of these plated steel sheets Zinc-based composite plated steel sheets (eg, Zn-SiO ₂ dispersed plated steel sheets) in which oxides, polymers, etc. are dispersed may be used. Moreover, the multilayer plating steel plate which plated two or more layers of the same or different types among the above platings can also be used.

As the aluminum-based plated steel sheet serving as the base of the surface-treated steel sheet of the present invention, an aluminum plated steel sheet, an Al-Si alloy plated steel sheet, or the like can be used.

In addition, the plated steel sheet may be coated with thin coating of Ni or the like on the steel sheet surface in advance, and various platings as described above may be performed thereon. As the plating method, any one of electrolytic methods (electrolysis in aqueous solution or electrolysis in non-aqueous solvent), melting method, and vapor phase method can be adopted.

Alkali degreasing, solvent degreasing, surface adjustment treatment (alkaline surface adjustment treatment or acidic surface adjustment treatment) are required on the surface of the coating coating in advance to prevent coating defects or stains from occurring when the surface treatment coating is formed on the surface of the coating coating. Processing) and the like.

In addition, in order to prevent black stools (a type of oxidation phenomenon on the plating surface) under the use environment, if necessary, an acidic or alkaline substance containing iron group metal ions (one or more of Ni ions, Co ions, and Fe ions) on the plating surface in advance. The surface adjustment treatment with an aqueous solution may be performed.

When using an electrogalvanized steel sheet as a base steel sheet, iron group metal ions (one or more of Ni ions, Co ions, and Fe ions) are added to the electroplating bath for the purpose of preventing black stools, and 1 ppm of these metals in the plating film. It can contain more. In this case, the upper limit of the iron group metal concentration in the plating film is not particularly limited.

In the surface-treated steel sheet of the present invention, the surface-treated film formed on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet includes a titanium-containing aqueous solution (A), a nickel compound (B), an aluminum compound (C), and fluorine-containing. It is formed by apply | coating and drying surface treatment composition (I) containing a compound (D) as an essential component.

The titanium-containing aqueous solution (A) comprises titanium obtained by mixing at least one titanium compound selected from hydrolyzable titanium compounds, low-condensates of hydrolyzable titanium compounds, low-condensates of titanium hydroxide and titanium hydroxide and hydrogen peroxide water. Aqueous solution.

The hydrolyzable titanium compound is a titanium compound having a hydrolyzable group which is directly bonded to titanium, and generates titanium hydroxide by reacting with water such as water and water vapor. In the hydrolyzable titanium compound, all of the groups bonded to titanium may be hydrolyzable or some of the groups bonded to titanium may be hydrolyzable.

The hydrolyzable group is not particularly limited as long as it forms titanium hydroxide by reacting with water as described above. Examples thereof include a lower alkoxyl group and a group forming a salt with titanium (for example, halogen atoms such as chlorine, hydrogen, etc.). Atoms, sulfate ions, and the like).

As the hydrolyzable titanium compound containing a lower alkoxyl group as the hydrolyzable group, tetraalkoxy titanium represented by general formula Ti (OR) ₄ (wherein R represents an alkyl group having 1 to 5 carbon atoms) is preferable. Do. Examples of the alkyl group having 1 to 5 carbon atoms include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and the like. As the hydrolyzable group, examples of the hydrolyzable titanium compound having a group which forms a salt with titanium include titanium chloride and titanium sulfate.

The low condensate of the hydrolyzable titanium compound is a low condensate of the above hydrolyzable titanium compounds. In this low-condensate, all of the groups bonded to titanium may be hydrolyzable or some of the groups bonded to titanium may be hydrolyzable.

For hydrolyzable titanium compounds (eg, titanium chloride, titanium sulfate, etc.) in which the hydrolyzable groups form salts with titanium, ortho titanic acid obtained by the reaction of an aqueous solution of the hydrolyzable titanium compound and an alkaline solution such as ammonia or caustic soda. (Titanium hydroxide gel) can also be used as a low condensate.

As a low condensate of a hydrolyzable titanium compound and a low condensate of titanium hydroxide, the compound of condensation degree 2-30 can be used, It is preferable to use the compound of condensation degree 2-10 especially. If the degree of condensation exceeds 30, white precipitates occur when mixed with hydrogen peroxide, and a stable titanium-containing aqueous solution cannot be obtained.

Examples of the hydrolyzable titanium compound, the low-condensation product of the hydrolyzable titanium compound, the titanium hydroxide, and the low-condensation product of the titanium hydroxide may be used alone or in combination of two or more thereof. Among them, the hydrolyzable titanium compound represented by the above-described general formula Phosphorus tetraalkoxy titanium is particularly preferred.

As a titanium-containing aqueous liquid (A), if it is an aqueous liquid containing titanium obtained by mixing said titanium compound and hydrogen peroxide solution, a conventionally well-known thing can be used without a restriction | limiting in particular. Specifically, the following are mentioned.

(Iii) A titanyl ion hydrogen peroxide complex or titanic acid (peroxo titanium hydrate) aqueous solution obtained by adding hydrogen peroxide to a gel or sol of hydrous titanium oxide (see Japanese Patent Application Laid-Open No. 63-35419, Japanese Patent Laid-Open No. Hei 1-224220). ).

(Ii) Titania film-forming liquid obtained by reacting hydrogen peroxide solution with titanium hydroxide gel prepared from an aqueous solution of titanium chloride or titanium sulfate and a basic solution and synthesizing it (Japanese Patent Application Laid-Open No. 9-71418, Japanese Patent Laid-Open No. 10-11). See publication 67516).

When obtaining this liquid for forming a titania film, a titanium hydroxide gel called ortho titanic acid is precipitated by reacting an aqueous solution of titanium chloride or titanium sulfate having a group which forms a salt with titanium and an alkaline solution such as ammonia or caustic soda. The yellowish transparent viscous liquid can then be obtained by separating the titanium hydroxide gel by decantation with water, washing well, further adding hydrogen peroxide and decomposing and removing excess hydrogen peroxide.

The ortho titanic acid precipitated is in a gel state polymerized by polymerization or hydrogen bonding of OHs, and cannot be used as it is as an aqueous liquid containing titanium. When hydrogen peroxide is added to this gel, a part of OH becomes peroxide, and it becomes a kind of sol which is dissolved as peroxo titanate ions or a polymer chain is divided into low molecules, and excess hydrogen peroxide is decomposed into water and oxygen to form an inorganic film. It can be used as an aqueous liquid containing titanium.

Since this sol contains only oxygen atoms and hydrogen atoms other than titanium atoms, when converted to titanium oxide by drying or calcining, only sol and water are generated. Therefore, the sol contains carbon and halogen components necessary for pyrolysis such as sol-gel method or sulfate. No removal is required, and a titanium oxide film having a relatively high density can be formed even at a low temperature.

(Iii) adding peroxide to an aqueous solution of inorganic titanium compounds of titanium chloride or titanium sulfate to form peroxotitahydrate, and then adding a basic substance to leave or heat the resulting solution to form a precipitate of the peroxotitahydrate hydrate polymer. Subsequently, a solution for forming titanium oxide obtained by removing at least a dissolved component other than water derived from a titanium-containing raw material solution and then reacting with hydrogen peroxide (see Japanese Patent Laid-Open Nos. 2000-247638 and 2000-247639).

The titanium-containing aqueous solution (A) using a hydrolyzable titanium compound and / or its low condensate (hereinafter referred to as &quot; hydrolyzable titanium compound a &quot; for the purpose of explanation) as a titanium compound is used to react the hydrolyzable titanium compound a with hydrogen peroxide solution and reaction temperature. It can obtain by making it react for 10 to 20 hours at 1-70 degreeC.

The titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a reacts with the hydrolyzable titanium compound a and hydrogen peroxide to hydrolyze the hydrolyzable titanium compound a to produce a hydroxyl group-containing titanium compound. Subsequently, it is thought that hydrogen peroxide coordinates to this hydroxyl-containing titanium compound, and this hydrolysis reaction and hydrogen peroxide coordination are obtained at the same time, and it is obtained, and the chelating liquid which is very stable in room temperature area | region and long lasts for long-term preservation is obtained. Create The titanium hydroxide gel used in the conventional manufacturing process is partially three-dimensionalized by Ti-O-Ti bonding, and its composition and stability are substantially different from those of the titanium-containing aqueous solution (A) in which the gel and the hydrogen peroxide solution are reacted. .

When the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a is subjected to heat treatment or autoclave treatment at 80 ° C. or higher, a titanium oxide dispersion liquid containing ultrafine particles of crystallized titanium oxide is obtained. If the heat treatment or autoclave treatment is less than 80 ° C, crystallization of titanium oxide does not proceed sufficiently. The titanium oxide dispersion prepared as described above has an average particle diameter of the 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 lowered (when dried after coating and formed into a film, cracking occurs at a film thickness of 1 µm or more). The external appearance of this titanium oxide dispersion liquid has a translucent shape. Such a titanium oxide dispersion liquid can also be used as a titanium-containing aqueous liquid (A).

The surface treatment composition (also called an aqueous treatment liquid, I) containing a titanium-containing aqueous solution (A) using a hydrolyzable titanium compound a is applied to the surface of the plated steel sheet and dried (for example, heated and dried at low temperature). It is possible to form a dense titanium oxide-containing film (surface treatment film) excellent in furnace adhesion.

As heating temperature after apply | coating surface treatment composition (I), 200 degrees C or less, especially 150 degrees C or less are preferable, The amorphous (amorphous) containing titanium oxide containing a few hydroxyl groups by heat-drying at such temperature is contained, for example. A film can be formed.

In the case where the titanium oxide dispersion obtained through the above heat treatment or autoclave treatment as described above is used as the titanium-containing aqueous solution (A), the crystalline titanium oxide-containing film is simply applied by applying the surface treatment composition (I). Since it can form, it is useful as a coating material of the material which cannot be heat-processed.

As the titanium-containing aqueous solution (A), a titanium-containing aqueous solution (A1) obtained by reacting a 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 (you may add, for example, an aqueous organic solvent such as alcohol or alcohol ether). As this titanium oxide sol, a conventionally well-known thing can be used, For example, (i) Titanium oxide aggregate obtained by hydrolyzing titanium solution, such as titanium sulfate and titanium sulfate, (ii) Organic titanium compounds, such as titanium alkoxide An amorphous titania sol obtained by dispersing a titanium oxide aggregate such as a titanium oxide aggregate obtained by hydrolysis, a titanium oxide aggregate obtained by hydrolysis or neutralizing a titanium halide solution such as titanium tetrachloride or the like, or the titanium oxide aggregate It is possible to use a sol which is calcined to make anatase titanium fine particles and dispersed in water.

In the firing of the amorphous titania, the amorphous titania can be converted into anatase-type titania by firing at a temperature of at least the crystallization temperature of the anatase, for example, 400 ° C to 500 ° C or higher. As an aqueous sol of this titanium oxide, it is TKS-201 (brand name, the product made by Teika Corporation, anatase type crystalline form, average particle diameter 6nm), TA-15 (brand name, the Nissan Chemicals company, anatase type crystalline form), STS-11, for example. (Brand name, the Ishihara industry company make, anatase type crystalline form), etc. are mentioned. In the titanium-containing aqueous solution (A1), the mass ratio (x / y) of the titanium oxide sol (x) and the titanium peroxide reactant (y, the reaction product of the hydrolyzable titanium compound a and the hydrogen peroxide solution) is 1/99 to 99. / 1, preferably in the range of about 10/90 to 90/10. If the mass ratio (x / y) is less than 1/99, the effect of adding the titanium oxide sol is not sufficiently obtained in terms of stability and photoreactivity. .

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

The production form and characteristics of the titanium-containing aqueous solution (A1) are the same as those of the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a described above. It is suppressed. The reason for this is considered that the condensation reactant is adsorbed on the surface of the titanium oxide sol and the polymerization in solution is suppressed.

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

Similarly to the titanium-containing aqueous solution (A) using the hydrolyzable titanium compound a described above, the surface treatment composition (I) containing the titanium-containing aqueous solution (A1) is applied and dried (for example, at a low temperature). Heat-drying) can form a dense titanium oxide-containing film (surface treatment film) that is excellent in adhesion.

As heating temperature after apply | coating surface treatment composition (I), for example, 200 degrees C or less, especially 150 degrees C or less are preferable, and anatase-type titanium oxide containing film containing a few hydroxyl groups is formed by heat-drying at such temperature. can do.

As described above, among the titanium-containing aqueous solutions (A), the titanium-containing aqueous solution (A) and the titanium-containing aqueous solution (A1) using the hydrolyzable titanium compound a have excellent performances in storage stability, corrosion resistance, and the like. Particular preference is given to using these.

The blending ratio of hydrogen peroxide to at least one titanium compound selected from hydrolyzable titanium compounds, low-condensates of hydrolyzable titanium compounds, titanium hydroxide and titanium hydroxide is in terms of hydrogen peroxide relative to 10 parts by mass of the titanium compound. 0.1-100 mass parts, Preferably it is 1-20 mass parts. When the compounding ratio of the hydrogen peroxide water is less than 0.1 parts by mass in terms of hydrogen peroxide, chelating formation is insufficient, so that a cloudy precipitate occurs. On the other hand, if it exceeds 100 parts by mass, unreacted hydrogen peroxide tends to remain and releases dangerous free radicals during storage, which is not preferable.

Although the hydrogen peroxide concentration of hydrogen peroxide water is not specifically limited, It is preferable that it is about 3-30 mass% for handling, since the solid content concentration of the production liquid which concerns coating workability is suitable.

In the titanium-containing aqueous solution (A), other sol or pigment may be added and dispersed as necessary. For example, as an additive, commercially available titanium oxide sol, titanium oxide powder, mica, talc, silica, barita, clay, etc. can be mentioned, One or more of these can be added.

The content of the titanium-containing aqueous liquid (A) in the surface treatment composition (I) is preferably 1 to 100 g / L, preferably 5 to 50 g / L, in terms of solid content, in view of the stability of the treatment liquid.

The surface treatment composition (I) used in the present invention is obtained by complex addition of a nickel compound (B), an aluminum compound (C) and a fluorine-containing compound (D) to the titanium-containing aqueous solution (A). The following effects are obtained. . That is, when the fluorine-containing compound (D) is added to the titanium-containing aqueous solution (A), the corrosion resistance and the storage stability are improved, but the blackening resistance deteriorates. On the other hand, when nickel compound (B) is added, blackening resistance improves, but corrosion resistance deteriorates. Therefore, deterioration of corrosion resistance is suppressed by adding aluminum compound (C). Therefore, it is considered that corrosion resistance, storage stability, and blackening resistance are all improved by adding a nickel compound (B), an aluminum compound (C), and a fluorine-containing compound (D) to the titanium-containing aqueous solution (A).

The said nickel compound (B) is mix | blended in order to improve blackening resistance, As a nickel compound (B), nickel acetate, nickel nitrate, a nickel sulfate, etc. are mentioned, for example, 1 type, or 2 or more types of these can be used. Can be. Among them, nickel acetate is very suitable in terms of improving blackening resistance.

The compounding quantity of a nickel compound (B) is 0.01-10 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous solution (A), Preferably you may be 0.1-2 mass parts. When the compounding quantity of the nickel compound (B) with respect to 100 mass parts of solid content of a titanium containing aqueous solution (A) is less than 0.01 mass part, the improvement of blackening resistance is not enough, and when it exceeds 100 mass parts, corrosion resistance deteriorates.

The said aluminum compound (C) is mix | blended in order to improve corrosion resistance, As an aluminum compound (C), aluminum nitrate, aluminum acetate, aluminum sulfate, aluminum oxide, aluminum acetylacetonate, aluminate, etc. are mentioned, for example. 1 type, or 2 or more types of these can be used. Among them, aluminum nitrate is very suitable in terms of improving water solubility and improving corrosion resistance.

The compounding quantity of an aluminum compound (C) is 1-100 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous liquid (A), Preferably it is 5-30 mass parts. When the compounding quantity of the aluminum compound (C) with respect to 100 mass parts of solid content of a titanium containing aqueous liquid (A) is less than 1 mass part, improvement of corrosion resistance is not enough, On the other hand, when it exceeds 100 mass parts, blackening resistance deteriorates.

In the present invention, the compounding ratio B / C of the nickel compound (B) and the aluminum compound (C) is in the range of 1/1 to 1/100 by mass ratio of the solid content, in particular, in terms of both blackening and corrosion resistance. Preferably, it is preferable to set it as 1/5-1/50.

The fluorine-containing compound (D) is blended to improve storage stability, corrosion resistance, water resistance, and the like. Examples of the fluorine-containing compound (D) include ammonium zircon fluoride, potassium zircon fluoride, zircon fluoride acid, and titanium fluoride. Ammonium, hydrofluoric acid, ammonium bifluoride, etc. are mentioned, These 1 type, or 2 or more types can be used. Especially, it is preferable to use 1 type chosen from ammonium zircon fluoride and a zircon hydrofluoric acid. In particular, ammonium zircon fluoride is very suitable in terms of corrosion resistance and water resistance after alkali degreasing, and zircon hydrofluoric acid is very suitable in corrosion resistance after alkali degreasing.

The compounding quantity of a fluorine-containing compound (D) is 1-800 mass parts with respect to 100 mass parts of solid content of a titanium-containing aqueous liquid (A), Preferably it is 50-500 mass parts. If 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 solution (A) is less than 1 part by mass, the improvement in storage stability, corrosion resistance, water resistance, and the like is not sufficient. Degeneration deteriorates.

The surface treatment composition (I) used in the present invention is essentially a titanium-containing aqueous liquid (A) and components (B) to (D) as described above. Further, if necessary, an organic phosphate compound (E), At least one selected from the group consisting of a vanadate compound (F), a zirconium carbonate compound (G), a water-soluble organic resin (H), and a water-dispersible organic resin (H) may be contained.

Examples of the organophosphate compound (E) include 1-hydroxymethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxypropane-1 and 1-. Hydroxyl group-containing organic phosphorous acid such as diphosphonic acid; Carboxyl group-containing organophosphorous acids such as 2-hydroxyphosphonoacetic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, and salts thereof are mentioned as very suitable ones, and one or two or more of them are mentioned. Can be used.

The organophosphate compound (E) has an effect of improving the storage stability of the titanium-containing aqueous solution (A). Among them, 1-hydroxyethane-1 and 1-diphosphonic acid are particularly effective because they are particularly effective. Particularly preferred. The compounding quantity of an organophosphate compound (E) is 1-400 mass parts with respect to 100 mass parts of solid content of a titanium-containing aqueous solution (A), It is preferable at the point of water-adhesion resistance etc. especially. When the compounding quantity of an organophosphate compound (E) exceeds 400 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous solution (A), since water resistance adhesiveness falls, it is unpreferable.

As said vanadate compound (F), lithium metavanadate, potassium metavanadate, sodium metavanadate, ammonium metavanadate, vanadate anhydride, etc. are mentioned, for example. Species or two or more kinds can be used. Among them, ammonium metavanadate is preferred in view of water resistance. The compounding amount of the vanadate compound (F) is 1 to 400 parts by mass, in particular 10 to 400 parts by mass, based on 100 parts by mass of the solid content of the titanium-containing aqueous solution (A), in terms of corrosion resistance after alkali degreasing the coating. desirable. When the compounding quantity of a vanadate compound (F) exceeds 400 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous solution (A), since corrosion resistance after alkali degreasing falls, it is unpreferable.

As said zirconium carbonate compound (G), salts, such as sodium, potassium, lithium, ammonium, of zirconium carbonate are mentioned, These 1 type, or 2 or more types can be used. Among them, zirconium ammonium carbonate is preferred in view of water resistance and the like. The blending amount of the zirconium carbonate compound (G) is preferably 1 to 400 parts by mass, particularly 10 to 400 parts by mass, based on 100 parts by mass of the solid content of the titanium-containing aqueous solution (A) in view of corrosion resistance after alkali degreasing the coating. Do. When the compounding quantity of a zirconium carbonate compound (G) exceeds 400 mass parts with respect to 100 mass parts of solid content of a titanium containing aqueous solution (A), since corrosion resistance after alkali degreasing falls, it is unpreferable.

The water-soluble organic resin and / or water-dispersible organic resin (H) is an organic resin that can be dissolved or dispersed in water, and a conventionally known method can be applied as a method of solubilizing or water-oxidizing the organic resin in water. Specifically, the organic resin contains a functional group (eg, a hydroxyl group, a polyoxyalkylene group, a carboxyl group, an amino (imino) group, a sulfide group, a phosphine group, etc.) capable of being solubilized or water-oxidized alone, and If necessary, some or all of these functional groups are acid resins (carboxyl group-containing resin etc.), Amine compounds, such as ethanolamine and triethylamine; ammonia; If neutralized with alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, and basic resin (amino-group containing resin etc.), Fatty acids, such as acetic acid and lactic acid; What was neutralized with inorganic acids, such as phosphoric acid, etc. can be used.

As the water-soluble or water-dispersible organic resin, for example, epoxy resin, phenol resin, acrylic resin, urethane resin, olefin-carboxylic acid resin, nylon resin, resin having polyoxyalkylene chain, polyvinyl alcohol, poly Glycerin, carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose 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 alkali resins, urethane resins and epoxy resins is preferable in view of storage stability of the surface-treated composition, and particularly water-soluble or water-dispersible alkali. It is preferable to use a system resin as a main component from the balance of the storage stability of a surface treatment composition and coating-film performance.

A water-soluble or water-dispersible alkaline resin can be obtained by a conventionally known method, for example, emulsion polymerization, suspension polymerization, polymers having hydrophilic groups by solution polymerization, and neutralization and aqueousization, if necessary. .

The polymer having a hydrophilic group can be obtained, for example, by polymerizing an unsaturated monomer having a hydrophilic group such as a carboxyl group, an amino group, a hydroxyl group, a polyoxyalkylene group, and other unsaturated monomers as necessary.

The water-soluble or water-dispersible alkali resin is preferably formed by copolymerizing styrene in terms of corrosion resistance and the like, and the amount of styrene in the total unsaturated monomer is preferably 10 to 60 mass%, particularly 15 to 50 mass%. Tg (glass transition point) of the acrylic resin obtained by copolymerization is 30-80 degreeC, It is preferable at the point of the toughness of the film obtained especially 40-70 degreeC.

Acrylic acid, methacrylic acid, maleic acid, maleic anhydride, crotonic acid, itaconic acid, etc. are mentioned as said carboxyl group-containing unsaturated monomer.

Examples of the nitrogen-containing unsaturated monomers such as the amino group-containing unsaturated monomers include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, Nt-butylaminoethyl (meth) acrylate, and the like. Nitrogen-containing alkyl (meth) acrylates; Acrylamide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxy Polymerizable amides such as methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, and N, N-dimethylaminoethyl (meth) acrylamide; Aromatic nitrogen-containing monomers such as 2-vinylpyridine, 1-vinyl-2-pyrrolidone and 4-vinylpyridine; And allylamine.

As said hydroxyl-containing unsaturated monomer, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2, 3- dihydroxy butyl (meth) acrylate, 4-hydroxybutyl (meth) acryl Monoesters of polyhydric alcohols such as latex, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and acrylic acid or methacrylic acid; The compound etc. which ring-opened-polymerized (epsilon) -caprolactone to the monoester of the said polyhydric alcohol and acrylic acid or methacrylic acid are mentioned.

As other unsaturated monomer, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) ) Acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, tridisil (meth) acrylate, octadisil (meth) Alkyl (meth) acrylates having 1 to 24 carbon atoms such as acrylate and isostearyl (meth) acrylate; Vinyl acetate etc. are mentioned.

The unsaturated monomer which mentioned the above example can use 1 type (s) or 2 or more types. In addition, in description of this application, "(meth) acrylate" means "acrylate or methacrylate."

As the urethane-based resin, a polyurethane composed of a polyol such as polyester polyol and polyether polyol and diisocyanate is chain-stretched in the presence of a chain extender, which is a low molecular weight compound having two or more active hydrogens such as diol and diamine, if necessary. And stably dispersed or dissolved in water can be suitably used, and conventionally known ones can be widely used (for example, JP-A-42-24192, JP-42-24194, JP-42). -5118, JP 49-986, KI 49-33104, JP 50-15027, JP 53-29175).

As a method of stably dispersing or dissolving a polyurethane resin in water, the following method can be used, for example.

(1) A method of imparting hydrophilicity by introducing ionic groups such as hydroxyl groups, amino groups, and carboxyl groups to the side chains or terminals of the polyurethane polymer, and dispersing or dissolving in water by self-emulsification.

(2) The polyurethane polymer which completed the reaction or the terminal isocyanate group blocked by blocking agent, such as oxime, alcohol, phenol, mercaptan, amine, and sodium bisulfite, is forcibly disperse | distributed in water using an emulsifier and a mechanical shear force. How to. A method of mixing a urethane polymer having a terminal isocyanate group with water, an emulsifier, and a chain extender, and simultaneously performing dispersing and high molecular weight using mechanical shear force.

(3) A method of dispersing or dissolving in water as a polyurethane soluble in water using a water-soluble polyol such as polyethylene glycol as the polyol of the polyurethane main raw material.

In addition, a polyurethane resin can also mix and use what was obtained by the other method of the dispersion | distribution or dissolution method mentioned above.

As diisocyanate which can be used for the synthesis | combination of the said polyurethane-type resin, aromatic, alicyclic, or aliphatic diisocyanate is mentioned, Specifically, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3'- dimethoxy-4, 4'-biphenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 1,3- (diisocyanate methyl) cyclohexanone, 1,4- (diisocyanatomethyl) cyclohexanone, 4,4'-diisocyanatocyclohexanone, 4,4'-methylenebis (cyclohexyl isocyanate), isophorodiisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenyl Rendiisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 4,4'-biphenylene Diisocyanate etc. are mentioned. Among these, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are especially preferable.

As a commercial item of a urethane resin, HYDRAN HW-330, the same HW-340, the same HW-350 (both brand names, Dainippon Ink & Chemicals Co., Ltd.), superflex 100, the same 150, the same E -2500, the same F-3438D (any and a brand name, the Dai-ichi Kogyo Pharmaceutical Co., Ltd. product) etc. are mentioned.

As said epoxy resin, Cation-type epoxy resin formed by adding an amine to an epoxy resin; Modified epoxy resins, such as acrylic modification and urethane modification, can be used suitably. Examples of the cationic epoxy resin include epoxy compounds and adducts such as primary mono or polyamines, secondary mono or polyamines, and primary and secondary mixed polyamines (for example, see US Patent No. 3,984, 299); Adducts such as secondary mono or polyamines having an epoxy compound and a kechiminized primary amino group (see, for example, US Pat. No. 4,017,438); The etherification reaction product of an epoxy compound and the hydroxyl compound which has a kechiminized primary amino group (for example, see Unexamined-Japanese-Patent No. 59-43013) etc. are mentioned.

As epoxy resin, it is preferable that number average molecular weights are 400-4000, especially 800-2000, and epoxy equivalents 190-2000, especially 400-1000. Such epoxy resin can be obtained, for example, by reaction of a polyphenol compound and epichlorohydrin. 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-dihydroxyphenyl sulfone, phenol novolak, cresol novolak, etc. are mentioned.

The compounding quantity of water-soluble organic resin or water-dispersible organic resin (H) is 30 mass parts or less with respect to 100 mass parts of solid content of a titanium-containing aqueous liquid (A), especially the uniformity of the film obtained by setting it as 5-20 mass parts, etc. It is preferable at the point of. When the compounding quantity of water-soluble organic resin or / and water dispersible organic resin (H) exceeds 30 mass parts, heat discoloration resistance will fall easily.

Further to the surface treatment composition (I), if necessary, for example, a silane coupling agent and a resin fine particle. Etching agents such as inorganic phosphate compounds, heavy metal compounds other than the components specified by the present invention, thickeners, surfactants, lubricants (polyethylene wax, fluorine wax, carnauba wax, etc.), rust preventive agent, coloring pigment, extender pigment, antirust Pigments, dyes and the like.

If necessary, the surface treatment composition (I) may be diluted with a hydrophilic solvent such as methanol, ethanol, isopropyl alcohol, an ethylene glycol solvent, or a propylene glycol solvent. The deposition amount of the surface treatment film formed by the surface treatment composition (I) is 0.1 to 2.0 g / m 2, preferably 0.2 to 1.5 g / m 2 fh. If the coating amount is less than 0.1 g / m 2, the corrosion resistance is inferior. On the other hand, if the coating amount is more than 2.0 g / m 2, the coating is easily broken and the corrosion resistance is lowered.

In order to manufacture the surface-treated steel sheet of the present invention, a titanium-containing aqueous solution (A), a nickel compound (B), an aluminum compound (C) and a fluorine-containing compound as described above on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet. As the main component (D), 1 of an organic phosphate compound (E), a vanadate compound (F), a zirconium carbonate compound (G), a water-soluble organic resin or / and a water-dispersible organic resin (H) as needed. After apply | coating the surface treatment composition (I, process liquid) containing species or more, it dries without washing with water.

The titanium-containing aqueous solution (A) or the surface treatment composition (I) may further contain other additives as mentioned above, if necessary.

The application means of the surface treatment composition (treatment liquid) is arbitrary, for example, spray + roll pressing, a roll coater, etc., and also the drying method after application is arbitrary, for example, a hot air method, an induction heating method, an electric furnace method.

It is preferable that the drying temperature of the apply | coated surface treatment composition (process liquid) shall be about 60-200 degreeC. If the drying temperature is less than 60 ° C, the film formation becomes insufficient, resulting in a film having poor corrosion resistance and the like. On the other hand, even if it dries at plate temperature exceeding 200 degreeC, the improvement effect of corrosion resistance corresponding to a drying temperature is not acquired, but corrosion resistance may fall rather. It is considered that this is because cracks are generated in the film due to heat.

Example  2

The titanium-containing aqueous liquid (A) and components (B) to (H) used in the surface treatment composition are shown below.

[Production of titanium-containing aqueous liquid (A)]

Preparation Example 1 (titanium-containing aqueous solution (T1))

Ammonia water (1: 9) was dripped at the solution which made 5 mm of titanium tetrachloride 60% solutions into 500 mm of distilled water, and titanium hydroxide was precipitated. After washing with distilled water, 10 cc of a 30% solution of hydrogen peroxide solution was added thereto, followed by stirring to obtain a yellow translucent, viscous titanium-containing aqueous solution (T1) containing titanium.

Preparation Example 2 (titanium-containing aqueous solution (T2))

A mixture of 10 parts by mass of tetraiso-propoxycitane and 10 parts by mass of iso-propanol was added dropwise while stirring at 20 ° C. over 1 hour in a mixture of 10 parts by mass of 30% hydrogen peroxide solution and 100 parts by mass of deionized water. Then, it aged at 25 degreeC for 2 hours, and obtained the yellow transparent slightly viscous titanium-containing aqueous liquid (T2).

Preparation Example 3 (titanium-containing aqueous solution (T3))

Titanium-containing aqueous solution (T3) was obtained under the same preparation conditions as in Preparation Example 2 except that tetran-butoxytitanium was used instead of tetraiso-propoxytitanium used in Preparation Example 2.

Preparation Example 4 (titanium-containing aqueous liquid (T4))

Titanium-containing aqueous solution (T4) was obtained under the same preparation conditions as in Preparation Example 2 except that a tetramer of tetraiso-propoxycitane was used instead of the tetraiso-propoxycitane used in Preparation Example 2.

Preparation Example 5 (titanium-containing aqueous solution (T5))

About Production Example 2 Titanium-containing aqueous solution (T5) was obtained under the same production conditions as in Production Example 2 except that the hydrogen peroxide solution was added dropwise at 50 ° C. over 1 hour, and further aged at 60 ° C. for 3 hours. .

Preparation Example 6 (titanium-containing aqueous solution (T6))

The titanium-containing aqueous solution (T3) prepared in Production Example 3 was further heat treated at 95 ° C for 6 hours to obtain a white-yellow translucent titanium-containing aqueous solution (T6).

Preparation Example 7 (titanium-containing aqueous solution (T7))

A mixture of 10 parts by mass of tetraiso-propoxycitane and 10 parts by mass of iso-propanol was mixed with "TS-203K" (trade name, manufactured by Teika Co., Ltd., titanium oxide sol) 5 parts by mass (solid content), 10 parts by mass of 30% hydrogen peroxide, and It was dripped at 10 degreeC over 1 hour in the mixture of 100 mass parts of deionized waters, stirring. 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 acetylacetonite

[Fluorine-containing compound (D)]

D1: ammonium zircon fluoride

D2: Zirconic Hydrofluoric Acid

D3: Sodium Zircon Fluoride

D4: potassium zircon fluoride

Organic Phosphate Compounds (E)

E1: 1-hydroxymethane-1,1-diphosphonic acid

E2: 1-hydroxyethane-1,1-diphosphonic acid

[Vanadic Acid Compound (F)]

F1: ammonium metavanadate

F2: Sodium Metavanadate

[Zirconium Carbonate Compound (G)]

G1: zirconium ammonium carbonate

G2: Sodium Zirconium Carbonate

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

H1: Superflex E-2500 (brand name, Daiichi Kogyo Pharmaceutical Co., Ltd., aqueous polyurethane resin)

H2: VYLONAL MD-1100 (trade name, product of Toyo Spin Co., Ltd., aqueous polyester resin)

H3: Adeka Resin EM-0718 (trade name, product of Adeka Industries, water-based epoxy resin)

As a base steel sheet of a surface-treated steel sheet, the plated steel sheet shown in Table 6 was used.

The surface treatment composition which suitably mix | blended said titanium-containing aqueous liquid (A) and components (B)-(H) was apply | coated to the surface of plated steel sheet, and it dried at the predetermined | prescribed drying temperature for 5 second, and used as a test material. About these test materials, heat discoloration resistance, corrosion resistance, and blackening resistance were evaluated by the following test method. The results are shown in Tables 7 to 10 together with the composition of the surface treatment composition applied to each specimen and its coating conditions.

(1) heat discoloration resistance

The test material was heated to a pan temperature of 500 ° C. for 30 seconds in an infrared image furnace, and kept for 30 seconds, and then visually observed the surface appearance when naturally cooled to room temperature. The evaluation criteria are as follows.

○: no discoloration

△: discoloration to pale yellow

X: discolor to yellow to multicolor

(2) corrosion resistance

About the test material which tape-sealed the edge part and the back surface, the salt spray test of JIS-Z-2371 was performed, and the test time which white-blue generation area ratio becomes 5% was measured. The evaluation criteria are as follows.

◎: 120 hours or more

○: more than 96 hours, less than 120 hours

△: 48 hours or more, less than 96 hours

×: less than 48 hours

(3) blackening resistance

The change in whiteness (L value) when the specimen was left standing for 24 hours in a constant temperature and humidity chamber controlled at a temperature of 80 ° C. and a relative humidity of 95% was calculated as ΔL (L value after the test-L value before the test). The evaluation criteria are as follows.

○: ΔL ≥ -5.0

Δ: -5.0> ΔL ≥ -10.0

×: -10.0> ΔL

In Table 7 and Table 9, * 1 to * 10 represent the following contents.

* 1 Plated steel sheets No. 1 to 9 listed in Table 6

* 2 Titanium-containing aqueous solution T1 to T7 described in the main body of the specification

* 3 Nickel compounds B1 to B3 described in the main text of the specification

* 4 Aluminum compounds C1 to C3 described in the text of the specification.

* 5 Fluorine-containing compounds D1 to D4 described in the main text of the specification

* 6 Organophosphate compounds E1 and E2 described in the text of the specification.

* 7 Banadinic acid compounds F1 and F2 described in the text of the specification.

* 8 Zirconium carbonate compounds G1 and G2 described in the text of the specification

* 9 Water-soluble or water-dispersible organic resins H1 to H3 described in the text of the specification.

* 10 Mass of solids in 1 liter of surface treatment composition (aqueous treatment liquid) (g)

Since the surface-treated steel sheet of the present invention is mainly composed of an inorganic component which does not accompany color development or discoloration by heating, it is excellent in heat discoloration resistance and has a chromate coating because the inorganic component has a high barrier property. It has excellent corrosion resistance and blackening resistance comparable to surface treated steel sheets.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the sample plate (photograph) used as the evaluation criteria of water resistance adhesion discoloration in Example 1. FIG.

Claims (6)

On the surface of the zinc-based plated steel sheet, the coating thickness containing titanium, nickel, aluminum and fluorine is 0.03 to 1.0 mu m, and the surface treatment coating has a titanium adhesion amount of 0.03 to 0.3 g / m 2, and titanium It contains 0.05-1.5 mass parts of nickel, 0.5-10 mass parts of aluminum, and 10-400 mass parts of fluorine with respect to 100 mass parts; The mass ratio of nickel and aluminum contained in the surface treatment film is in the range of 1: 5 to 1:25; The surface treated film further contains 30 to 1000 parts by mass of zirconium, 10 to 200 parts by mass of phosphorus and 5 to 300 parts by mass of vanadium with respect to 100 parts by mass of titanium. delete At least one titanium compound selected from the group consisting of a hydrolyzable titanium compound, a low-condensation product of a hydrolyzable titanium compound, a titanium hydroxide, and a titanium hydroxide low-condensation product is formed on the surface of a zinc-based plated steel sheet or an aluminum-based plated steel sheet. Titanium-containing aqueous solution obtained by mixing, and 0.01 to 10 parts by mass of nickel compound, 5 to 30 parts by mass of aluminum compound, and 50 to 500 parts by mass of fluorine-containing compound to 100 parts by mass of solids of the titanium-containing aqueous solution The coating amount formed by applying and drying the surface treatment composition has a surface treatment film of 0.1 to 2.0 g / m 2; The compounding ratio of the nickel compound and the aluminum compound is in the range of 1: 5 to 1:50; The fluorine-containing compound is at least one member selected from the group consisting of ammonium zircon fluoride and zircon fluoric acid; The surface treatment composition contains 20 to 300 parts by mass of an organic phosphate compound, 10 to 400 parts by mass of vanadate acid compound, and 10 to 400 parts by mass of zirconium carbonate compound with respect to 100 parts by mass of the solid content of the titanium-containing aqueous solution; The surface-treated steel sheet contains at least one resin selected from the group consisting of water-soluble organic resins and water-dispersible organic resins, based on 100 parts by mass of the solid content of the titanium-containing aqueous liquid. delete delete delete

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