JP2010090407A - Liquid for treating metal surface, and method for treating metal surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid for treating metal surface and a method for treating metal surface which can impart excellent corrosion resistance and excellent coating adhesiveness on the metal surface, and high electrodeposition coating, in particular, to provide an economically inexpensive liquid for treating metal surface and an economically inexpensive method for treating metal surface which can impart high throwing power in the electrodeposition coating equivalent to that of phosphate without drying when being applied to an automobile body and components thereof, providing adequate corrosion resistance and coating adhesiveness, suppressing and easily controlling industrial wastes such as sludge in the industrialization and operation. <P>SOLUTION: The liquid for treating metal surface contains: at least one water-soluble tellurium compound (A); and at least one compound (B) selected from a group composed of water-soluble titanium compound and water-soluble zirconium compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel metal surface treatment agent, surface treatment liquid and surface treatment method for imparting excellent corrosion resistance and paint adhesion to the surface of metals, particularly metal structures.

  Chemical conversion treatment has been used for a long time for the purpose of imparting corrosion resistance and paint adhesion for metals. The chemical conversion treatment is classified as a surface treatment, and involves a considerable amount of metal material dissolution (etching). The most common is phosphating. Phosphate treatment is based on an acidic phosphoric acid aqueous solution. In phosphating, for example, when the most common steel material is processed as a metal material, the metal surface is etched (corrosion phenomenon) when the phosphating solution comes into contact with the steel material. At this time, phosphoric acid is consumed, resulting in an increase in pH at the solid-liquid interface. Thereby, insoluble phosphate precipitates on the surface. Further, by allowing zinc or manganese to coexist in the treatment liquid, crystalline salts such as zinc phosphate and manganese phosphate can be precipitated. These phosphate films are suitable as a coating base treatment, and exhibit excellent effects such as improvement in paint adhesion, suppression of under-coating corrosion, and significant improvement in corrosion resistance.

  The phosphating process itself has already been in use for nearly 100 years, and many improved inventions have been devised during that time. However, since the steel material is etched, eluted iron is generated as a by-product of the chemical conversion reaction. This iron is precipitated in the system as iron phosphate and is periodically discharged out of the system. In general, the precipitate is called sludge. Currently, this sludge is dumped as industrial waste or reused as part of raw materials such as tiles. However, from the viewpoint of global environmental conservation in recent years, reduction of industrial waste has become a major issue. For this reason, a chemical conversion treatment solution and a processing method that do not generate waste are desired.

  Next, as a typical chemical conversion treatment, there is a chromate chemical conversion treatment. The chromic acid chromate chemical conversion treatment has a long history of practical use and is still widely used for surface treatment of aircraft materials, building materials, automobile parts, etc. Since this chromate chemical conversion treatment solution contains chromic acid composed of hexavalent chromium as a main component, a chemical conversion film partially containing hexavalent chromium is formed on the surface of the metal material. Although the chromate conversion coating has excellent corrosion resistance and paint adhesion, it contains harmful hexavalent chromium. Therefore, a chemical conversion treatment solution and conversion coating containing no hexavalent chromium are strongly desired because of environmental problems. Yes.

  On the other hand, metal structures for transportation represented by automobiles are subjected to electrodeposition coating in order to impart anticorrosion performance. In this case, electrodeposition coating without drying after chemical conversion treatment of the metal structure is a common coating method worldwide. In electrodeposition coating, since the paint is deposited by electrolytic treatment, the paint film thickness tends to be relatively uniform. For this reason, it is suitable for painting of structures. However, in the case of a particularly complicated structure such as an automobile body or a part, there are places where it is difficult for electricity to flow due to the structure. For this reason, in a bag structure etc., a difference arises in the coating film thickness of an outer surface and an inner surface. In general, it is called “circumstance with electrodeposition coating”, and it is desired to have good circulation with electrodeposition coating.

A number of inventions have been devised for improving the reversibility with electrodeposition coating.
For example, Patent Document 1 uses a cationic electrodeposition coating composition containing an amine-added epoxy resin (I) modified with alkylphenol and polycaprolactone as a base resin and a blocked polyisocyanate curing agent (II) as a curing component. In addition, when the electrodeposition of the article having a bag structure is applied, the polarization resistance value (a) per unit film thickness of the coating film is 125 to 150 kΩ · cm ² / μm, and the amount of paint deposited per unit amount of electricity When the condition (b) is 28 to 50 mg / C, the inner plate / outer plate thickness (c) in throwing power is 10 μm for the inner plate thickness and 10 to 12 μm for the inner plate thickness. An electrodeposition coating film forming method for obtaining a coating film having a ratio of thickness to outer film thickness of 10/10 to 12, a cationic electrodeposition coating composition used in this method, and a coated article coated by the method are shown. Has been.

In Patent Document 2, a cationic electrodeposition paint is used in order to improve the throwing power in the cationic electrodeposition coating, and the paint characteristics at the time of electrodeposition coating are as follows:
(A) The electrical conductivity of the paint is 0.16 S / m or more,
(B) The electric conductivity of the coating film is 1.0 × 10 ⁻⁷ S / m or less,
(C) the precipitation ineffective electric quantity is 320 coulomb / m ² or less, and (d) the electrochemical equivalent is 1.0 × 10 ⁻⁴ kg / coulomb or more,
The method of performing electrodeposition coating with adjustment is shown.

  As described above, in the complicated structure represented by the automobile body, the throwing power of the electrodeposition coating is an important issue. However, as a solution to this problem, conventionally, only the approach from the painting side such as improvement of paint and improvement of electrodeposition conditions has been made. In general, phosphating has a relatively high electrodepositionability, but it is important to provide an electrodepositionability equal to or higher than that for practical use of alternative technologies. It is a problem, and it is desirable to improve the throwing power from the chemical conversion film side, which is a ground treatment.

  A great number of inventions have been proposed as chemical conversion treatment solutions and surface treatment methods other than phosphating and not containing hexavalent chromium, but there are not so many technologies that can be industrialized. Is described below.

  As a typical invention of a non-chromate type chemical conversion treatment solution containing no chromium, there is a treatment solution disclosed in Patent Document 3. This chemical conversion treatment solution is an acidic aqueous coating solution containing zirconium or titanium or a mixture thereof, phosphoric acid and fluoride, and having a pH of about 1.5 to 4.0. When the metal surface is treated with this chemical conversion treatment liquid, a chemical conversion film mainly composed of an oxide of zirconium or titanium is formed on the metal surface. This non-chromate type chemical conversion treatment solution has the advantage of not containing hexavalent chromium, and is actually widely used for the surface treatment of aluminum D & I cans used in beverage cans such as beer. This is a classic technique that falls into the category of non-chromium chemical conversion treatment liquids generally called zirconium-based or titanium-based.

  The treatment method disclosed in Patent Document 4 includes a surface of aluminum, magnesium and an alloy thereof, one or more of titanium salt or zirconium salt, one or more of imidazole derivatives, nitric acid, hydrogen peroxide, Surface treatment is performed using an aqueous solution containing an oxidizing agent such as potassium permanganate. The oxidizing agent promotes the precipitation of titanium and zirconium. This treatment method is in the category of improvement technology of non-chromium chemical conversion treatment solution called zirconium-based or titanium-based.

As the non-chromate type treatment liquid, the following proposals can be further cited.
Patent Document 5 discloses a chemical conversion treatment solution comprising an aqueous solution containing a vanadium compound and at least one compound selected from the group consisting of a titanium salt, a zirconium salt and a zinc salt. This treatment liquid is obtained by combining vanadium with the above-described zirconium- and titanium-based non-chromium chemical conversion treatment liquid.

  Patent Document 6 discloses an acidic metal surface treatment solution containing metal acetylacetonate, at least one compound selected from a water-soluble inorganic titanium compound and a water-soluble inorganic zirconium compound. This treatment liquid uses vanadyl acetate, zirconium acetate, zinc acetate or the like. This treatment liquid is a composite of metal acetate and zirconium- and titanium-based non-chromium chemical conversion treatment liquid.

  Patent Document 7 contains 0.01 to 50 g / L permanganic acid or a salt thereof, and 0.01 to 20 g / L of at least one compound selected from a water-soluble titanium compound and a water-soluble zirconium compound. In addition, surface treatment liquids for light metal or light alloy materials having a pH of 1.0 to 7.0 have been proposed. This treatment liquid is in the category of a non-chromium chemical conversion treatment liquid called manganese-titanium or manganese-zirconium.

  Patent Document 8 discloses high corrosion resistance for aluminum and aluminum alloys containing hexacyanoate ion and one or more metal ions selected from the group consisting of Ti, V, Mn, Fe, Co, Zr, Mo and W. A chromium-free chemical film treatment agent is disclosed. Elements other than cobalt are the elements mentioned in the above proposal.

  Patent Document 9 proposes a chromium-free metal surface treatment composition in which a film generated by surface treatment on a metal surface includes a plurality of metal elements, and at least one metal element has a plurality of valences. Yes. Actually, at least two of Mg, Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Nb, Y, Zr, Mo, In, Sn, Ta and W are used as metal elements. It is a metal surface treatment composition using more than one kind. This treatment composition is considered to be an expansion of the zirconium-based, titanium-based, vanadium-based, tungsten-based, molybdenum-based, and manganese-based non-chromium chemical conversion treatment solutions.

  Patent Document 10 discloses (1) a compound A containing at least one metal element selected from Hf (IV), Ti (IV) and Zr (IV), and (2) a metal contained in the compound A. A fluorine-containing compound in an amount sufficient to cause at least 5 times the molar concentration of fluorine in the composition to be present in the composition, (3) at least one metal ion B selected from alkaline earth metals, (4) Al Surface treatment compositions for aluminum, aluminum alloys, magnesium or magnesium alloys containing at least one metal ion C selected from Zn, Mg, Mn and Cu and (5) nitrate ions have been proposed. In a broad sense, this treatment liquid is on the extension of zirconium-based and titanium-based non-chromium chemical conversion treatment liquids.

  Further, Patent Document 11 includes a step (A) of treating a treatment object with a non-chromium metal surface treatment agent comprising a water-soluble zirconium compound and / or a water-soluble titanium compound (1) and an organic phosphonic acid compound (2), And a non-chromium metal surface treatment method comprising a step (B) of treating an object subjected to the step (A) with an aqueous solution of tannin (3), wherein the water-soluble zirconium compound and / or the water-soluble titanium compound (1 ) Is 40 to 1000 ppm on a mass basis as the amount of zirconium and / or titanium, the content of the organic phosphonic acid compound (2) is 20 to 500 ppm on a mass basis, and the non-chromium metal surface treatment agent is The pH is 1.6 to 4.0, and the content of tannin (3) in the aqueous solution is 400 to 10000 ppm by mass. Non-chromium metal surface treatment wherein the bets have been proposed. In a broad sense, this treatment liquid is on the extension of zirconium-based and titanium-based non-chromium chemical conversion treatment liquids.

  Patent Document 12 includes a step (A) of treating an object to be treated with a non-chromium metal surface treatment agent comprising a water-soluble zirconium compound and / or a water-soluble titanium compound (1) and an organic phosphonic acid compound (2), and A non-chromium metal surface treatment method comprising a step (B) of treating an object to be treated which has undergone step (A) with an aqueous solution of tannin (3), wherein the organic phosphonic acid compound (2) comprises phosphorous constituting a phosphonic group. An atom is bonded to a carbon atom, and the content of the water-soluble zirconium compound and / or the water-soluble titanium compound (1) is 20 to 800 ppm on a mass basis as the amount of zirconium and / or titanium. The content of the compound (2) is 10 to 500 ppm on a mass basis, and the tannin (3) aqueous solution has a tannin concentration of 3 on a mass basis. A non-chromium metal surface treatment method is proposed, characterized in that the non-chromium metal surface treatment agent has a pH of 1.6 to 4.0 and is used for the production of a thermoplastic polyester resin-coated metal plate. Has been. In a broad sense, this treatment liquid is also an extension of the zirconium-based and titanium-based non-chromium chemical conversion treatment liquid as before.

  In Patent Document 13, the aqueous acidic liquid composition is (A) at least one selected from the group consisting of Ti, V, Mn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd and W; B) at least one selected from the group consisting of organic acids and / or inorganic acids and / or salts thereof, and (C) fluorine as an optional component, wherein the aqueous liquid composition is trivalent chromium, Ti, V, Mn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, W, Li, Na, K, Be, Mg, Ca, Al, Fe, Ni, Co, Si, Sr, In, Ag, Zn, Cu, Sc, organic acid, inorganic acid, organic acid salt, inorganic acid salt, amino acid, amino acid salt, fluorine, amines, alcohols, water-soluble polymer, surfactant, silane coupling agent, carbon powder ,dye, Fee, the processing solution containing at least one selected from the group consisting of colloidal organic and inorganic colloids are mentioned. This treatment liquid is also on the extended line of the zirconium-based and titanium-based non-chromium chemical conversion treatment liquid as before.

  Patent Document 14 discloses a coating pretreatment method for treating a workpiece with a chemical conversion treatment liquid to form a chemical conversion film, wherein the chemical conversion treatment liquid is at least one selected from the group consisting of zirconium, titanium and hafnium, fluorine. In addition, a coating pretreatment method comprising at least one selected from the group consisting of an amino group-containing silane coupling agent, a hydrolyzate thereof, and a polymer thereof has been proposed. This treatment liquid is also on the extension line of the zirconium-based and titanium-based non-chromium chemical conversion treatment liquid, and is added with a silane coupling agent which is a known technique.

  Patent Document 15 discloses a chemical conversion treatment solution comprising at least one selected from the group consisting of zirconium, titanium, and hafnium, fluorine, and adhesion and corrosion resistance imparting agent, wherein the adhesion and corrosion resistance imparting agent are zinc, At least one metal ion (A) selected from the group consisting of manganese and cobalt ions (A) 1 to 5000 ppm (metal ion concentration), alkaline earth metal ions (B) 1 to 5000 ppm (metal ion concentration), periodic table It consists of 3 group metal ions (C) 1-1000 ppm (metal ion concentration), copper ions (D) 0.5-100 ppm (metal ion concentration), and silicon-containing compound (E) 1-5000 ppm (as silicon component). A chemical conversion solution that is at least one selected from the group has been proposed. This treatment liquid is also on the extended line of the zirconium-based and titanium-based non-chromium chemical conversion treatment liquid as before, but as an adhesion imparting agent, zinc ions, alkaline earth metal ions, group 3 metal ions of the periodic table ( (Preferably described as aluminum), copper ions, silicon-containing compounds and the like are added.

Patent Document 16 includes at least one selected from the group consisting of zirconium, titanium, and hafnium, fluorine, an adhesion imparting agent, and a chemical reaction accelerator, and the adhesion imparting agent contains metal ions such as zinc, silicon-containing Compound, water-soluble resin having an amino group and having at least — (— CH ₂ —CHNH ₂ —) — or — (— CH ₂ —CHCH ₂ NH ₂ —) — as a structural unit, epoxy compound, and silane cup The chemical conversion reaction accelerator is at least one selected from the group of nitrite ions, nitro group-containing compounds, organic acids, etc., and the compounding amount thereof is 1 to 5000 ppm. Treatment liquids have been proposed. This treatment liquid is also on the extension line of the zirconium-based and titanium-based non-chromium chemical conversion treatment liquid as before, but contains an organic substance and is close to the resin-metal non-chromium chemical conversion treatment liquid shown below.

  On the other hand, in chemical conversion treatment liquids and chemical conversion treatment methods aimed at imparting corrosion resistance and paint adhesion to aluminum-containing metal materials and the like, those using water-soluble resins are disclosed in, for example, Patent Literature 17 to Patent Literature 23. ing. In these conventional chemical conversion treatment solutions and chemical conversion treatment methods, the metal surface is treated with a solution containing a derivative of a polyhydric phenol compound. These are in a category called a resin-based or resin-metal composite-based non-chromium chemical conversion treatment solution.

  Patent Document 24 includes a zirconium compound, fluorine ions, a water-soluble resin, and an aluminum salt. The concentration of the zirconium compound is 100 to 100,000 ppm in terms of zirconium ion, the fluorine ion concentration is 125 to 125,000 ppm, and the nonvolatile content concentration of the water-soluble resin is A non-chromium antirust treatment solution for aluminum having a concentration of 100 to 100,000 ppm and an aluminum salt concentration of 10 to 10,000 ppm in terms of aluminum ions has been proposed. This is also a non-chromium chemical conversion treatment liquid in which the above resin system and zirconium system are combined.

  On the other hand, a chemical conversion treatment solution using trivalent chromium which is not completely non-chromium but does not contain harmful hexavalent chromium has been proposed. Patent Document 25 discloses at least one ion (B) selected from an acid ion (A) having a phosphorus-containing acid group and a trivalent chromium ion, and a compound ion having trivalent chromium, a fluoride, a complex fluoride. A hexavalent chromium-free chemical conversion surface treatment solution for aluminum and aluminum alloys containing at least one fluorine compound (C) selected from chemical compounds has been proposed. This treatment liquid belongs to a category called trivalent chromium.

  Patent Document 26 discloses a chemical conversion treatment solution used after treating a substrate made of aluminum or an aluminum alloy with an acidic aqueous solution at 10 to 70 ° C. for 5 seconds to 5 minutes, wherein the acidic aqueous solution is (a) Fe, At least one selected from the group consisting of a metal salt selected from Ni, Co, Mo and Ce and a metal acid salt is 0.01 to 5% by mass of the acidic aqueous solution, and (b) a pH of 2 or less containing an inorganic acid The chemical conversion treatment solution is (c) Zr and / or Ti containing 0.001 to 1% by mass of the chemical conversion treatment solution, and (d) trivalent chromium ions or salts thereof being 0.1% of the chemical conversion treatment solution. Chemical conversion liquids containing ˜1000 ppm and (e) fluoride have been proposed. This treatment liquid is similar to Patent Document 25 and belongs to the trivalent chromium system.

  Patent Document 27 includes (A) trivalent chromium ion, (B) Mo, W, Ti, Zr, Mn, Tc, Fe, Ru, Co, alkaline earth metal, Ni, Pd, Pt, Sc, Y , V, Nb, Ta, Cu, Ag and Au, (C) one or more members selected from the group consisting of chlorine, fluorine, sulfate ions and nitrate ions, and (D) of phosphorus There has been proposed a method for forming a colored anticorrosive film for a metal which forms an anticorrosive film with a liquid composition containing at least one member selected from the group consisting of oxygen acids, oxyacid salts, anhydrides, and phosphorus compounds. This invention is basically similar to Patent Document 25 and belongs to the trivalent chromium system.

  In Patent Document 28, in a method for producing a chemical conversion film containing no hexavalent chromium by treating a metal surface with a solution of at least one trivalent chromium chelate complex, 5 to 100 g of the chelate complex trivalent chromium is contained in the solution. It has been proposed that a trivalent chromium chelate complex that is present at a concentration of / l uses a solution that has a faster ligand substitution rate than the fluoride substitution rate in a trivalent chromium-fluoro complex. This solution belongs to the trivalent chromium system.

  Also, the same technology is often used for zinc die casting. Patent document 29 describes a substantially coherent conversion layer of hexavalent chromium and trivalent chromium on zinc or a zinc alloy, and further components such as silicate, cerium, aluminum and borate. In the absence of a salt spray test according to DIN 50021 SS or ASTM B 117-73, providing corrosion protection of about 100 to 1000 hours until the first erosion according to DIN 50961 Chapter 10, clear, transparent and A conversion layer that is basically colorless, exhibits multicolored gloss, has a layer thickness of about 100 to 1000 nm, is hard and has good adhesion, and is resistant to wiping. Proposals have been made regarding trivalent chromium coatings on zinc. This belongs to the trivalent chromium system.

Patent Document 30 related to the same applicant includes a water-soluble trivalent chromium compound (A), a water-soluble Ti and / or zirconium compound (B), a water-soluble nitric acid compound (C), and a water-soluble aluminum compound (D). And an aqueous acid chemical conversion treatment solution containing a fluorine compound (E) and adjusted to pH = 2.3 to 5.0 is brought into contact with the surface of the metal material for 1 to 60 seconds, washed with water and dried. includes a 1 mmol / m ² of Cr and 0.02~1mmol / m ² of Ti and / or Zr, it has been proposed to form a conversion coating with a thickness of 1 to 100 nm. This also belongs to the trivalent chromium system.

  Further, Patent Document 31 discloses a method of forming a protective film on the surface of a metal, wherein (I) the surface is coated with a layer of an aqueous acidic liquid composition, the composition comprising water and (A) a negative electrode. Each of the ionic components is (i) at least 4 fluorine atoms, (ii) at least one element selected from the group consisting of titanium, zirconium, hafnium, silicon and boron, and (iii) 1 An anionic component comprising at least one oxygen atom; (B) a cationic component selected from the group consisting of cobalt, magnesium, manganese, zinc, nickel, tin, zirconium, iron, aluminum and copper; and (C) a composition. An amount of free acid sufficient to keep the pH of the product within the range of about 0.5 to about 5.0 and, optionally, (D) a composition that forms an organic thin layer by direct drying; B) a liquid composition in which the number of cations is 1/3 or more of the number of anions in component (A); and (II) the aqueous acidic liquid composition layer is dried as it is without intermediate rinsing. A metal surface treatment method comprising the steps is disclosed. This is a coating type surface treatment method, which is different from the chemical conversion reaction type in which a material is dissolved to form a film.

  Similarly, in Patent Document 32, on the surface of a zinc-based or aluminum-based plated steel sheet, (a) an epoxy group-containing resin (A), a primary amine compound and / or a secondary amine compound (B), An aqueous epoxy resin dispersion in which a modified epoxy resin obtained by reacting a part or all of the active hydrogen-containing compound (C) composed of a hydrazine derivative having active hydrogen is dispersed in water; and (b) a urethane resin. The film thickness formed by applying and drying a surface treatment composition containing an aqueous dispersion, (c) a silane coupling agent, and (d) phosphoric acid and / or hexafluorometal acid is 0. Although the invention having a surface treatment film of 01 to 5 μm is mentioned, this is also roughly classified into a coating type surface treatment.

  Summarizing conventional proposals regarding surface treatment, (1) zirconium-based or titanium-based and derivatives thereof, (2) vanadium, molybdenum, tungsten, cobalt-containing systems, (3) organic systems containing tannic acid or water-soluble resins (4) Organic / inorganic composite system combining zirconium and resin, (5) Trivalent chromium system, and (6) Coating type system.

  Among these, (5) the trivalent chromium system has trivalent chromium in the film to be formed. When this film is exposed to high temperatures, trivalent chromium is oxidized to hexavalent chromium which is harmful to the human body. For this reason, it can be said that it is an inappropriate technique from the viewpoint of environmental conservation. (6) The coating type system can be used when the structure is simple, such as a sheet material or a coil material, but a complex structure typified by an automobile causes a liquid pool to form a uniform film. I can't.

  (1) Zirconium-based materials are sufficiently industrialized and practically used in applications such as paint base applications, cold rolled materials with a uniform aluminum surface, and applications where corrosion resistance requirements are not strict. There is also. For example, the treatment liquid mainly composed of phosphoric acid, fluorozirconic acid and nitric acid described in Patent Document 33 has been put into practical use for surface treatment of aluminum D & I cans and is still used after more than 25 years. However, metal structures for transportation vehicles represented by automobiles are complex in shape, composite materials such as cold-rolled steel sheets and galvanized steel sheets, and sufficient for subsequent electrodeposition coating. There are various demands such as the need to have a swiftness and the fact that there is little waste in the chemical conversion treatment process. .

  (2) Vanadium, molybdenum, tungsten, and cobalt-containing systems have been put into practical use as zirconium-based development systems, but their corrosion resistance has not been dramatically improved, and they are represented by automobiles as described above. Transportability of transport vehicles with electrodeposition coating is not good.

  (3) Even if an organic system containing tannic acid or a water-soluble resin, (4) an organic / inorganic composite system in which zirconium and a resin are combined, (1) the corrosion resistance may be improved as compared with the zirconium system. However, it is incomplete when considering the wrapping property of electrodeposition coating as a metal structure for transportation represented by automobiles.

  Further, as a recent technology, Patent Document 34 includes zirconium ions and / or titanium ions, an adhesion imparting agent, and a stabilizer that suppresses elution of components in a rust preventive film during cationic electrodeposition coating. In the metal surface treatment method for forming a rust-preventive film having excellent circulation properties on a metal base material having a plurality of curved portions, using the metal surface treatment composition for cationic electrodeposition coating pretreatment, It has been proposed to use an adhesion-imparting agent containing at least one selected from the group consisting of :) a silicon-containing compound, (B) an adhesion-imparting metal ion, and (C) an adhesion-imparting resin. (A) The silicon-containing compound is at least one selected from the group consisting of silica, silicofluoride, water-soluble silicate compound, silicate ester, alkyl silicate, and silane coupling agent, and (B) adhesion The imparting metal ion is at least one metal ion selected from the group consisting of magnesium, zinc, calcium, aluminum, gallium, indium, copper, iron, manganese, nickel, cobalt, and silver, and (C) imparting adhesion The resin is at least one selected from the group consisting of a polyamine compound, a blocked isocyanate compound, and a melamine resin. Even if the inventors re-executed the example described in Patent Document 34, sufficient results were not always obtained as compared with the conventional phosphate coating.

  Patent Document 35 discloses at least one kind of adhesion selected from the group consisting of zirconium ions and / or titanium ions, (A) silicon-containing compounds, (B) adhesion-imparting metal ions, and (C) adhesion-imparting resins. A surface treatment step of bringing the metal surface treatment composition containing the property imparting agent into contact with the metal substrate, and a post-treatment step of heat-treating the metal substrate that has undergone the surface treatment step. ) A step of drying the metal substrate at a temperature of 60 ° C. to 190 ° C. for 30 seconds or more under atmospheric pressure or pressure, and (2) the metal substrate under atmospheric pressure or pressure. A surface treatment method for improving the throwing power of cationic electrodeposition coating, which is at least one selected from the group consisting of heat treatment at 60 ° C. to 120 ° C. for 2 seconds to 600 seconds or more It has been disclosed. However, when carrying out the present invention, a hot air drying furnace or a hot water process is required, which is industrially disadvantageous in terms of cost increase and process increase, and is not practical.

  Patent Document 36 discloses at least one kind of adhesion selected from the group consisting of zirconium ions and / or titanium ions, (A) silicon-containing compounds, (B) adhesion-imparting metal ions, and (C) adhesion-imparting resins. A metal surface treatment method comprising a surface treatment step of a metal substrate that forms a rust-preventive film by surface treatment of the metal substrate using a composition for surface treatment containing a property imparting agent, and a post-treatment step. The post-processing step is selected from the group consisting of step (a), step (b), step (c), step (d), step (e), step (f), and step (g). A metal surface treatment method for improving the throwing power of at least one cationic electrodeposition coating is disclosed. (A) a step in which all or part of the metal substrate that has undergone the surface treatment step is contact-treated with an alkaline aqueous solution having a pH of 9 or higher; (b) all or part of the metal substrate that has undergone the surface treatment step is subjected to polyanion. A step of contact treatment with an aqueous solution; (c) a step of subjecting all or part of the metal substrate subjected to the surface treatment step to contact treatment with the polyvalent anion aqueous solution and then a washing treatment with water; (d) a metal subjected to the surface treatment step. A step of contacting all or part of the base material with an oxidizing agent; (e) a step of contacting all or part of the metal base material that has undergone the surface treatment step with the oxidizing agent and then washing with water; f) a step of contacting the whole or part of the metal substrate that has undergone the surface treatment step with a fluorine stabilizer; and (g) a whole or part of the metal substrate that has undergone the surface treatment step being subjected to a fluorine stabilizer. After contact treatment, further water washing treatment That process has been proposed. However, in any case, after the chemical conversion treatment, there is a post-treatment step, which is unfavorably industrially costly and increases in number of steps, and is not practical.

JP 2004-083824 A JP 2004-269942 A JP 52-131937 A JP-A-57-41376 JP-A-56-136978 JP 2000-199077 A JP 11-36082 A JP 2004-232047 A JP 2001-247777 A International Publication WO03 / 074761A1 JP 2003-313679 A JP 2003-313681 A JP 2003-171778 A Japanese Patent Application Laid-Open No. 2004-218070 JP 2004-218073 A JP 2004-218075 A JP-A-61-91369 JP-A-1-172406 JP-A-1-177379 JP-A-1-177380 JP-A-2-608 JP-A-2-609 Japanese Patent No. 2771110 JP 2001-303267 A Japanese Patent No. 3333311 JP 2000-332575 A JP 2004-010937 A JP 2004-3019 A Japanese Patent No. 35597542 Japanese Patent No. 3784400 JP-A-5-195244 JP 2004-238716 A Japanese Patent Laid-Open No. 52-131937 JP 2008-88551 A JP 2008-88552 A JP 2008-88553 A

  As described above, chemical coatings formed by applying conventional non-chromate type surface treatment liquids to metal structures for transportation vehicles such as automobiles have a wide variety of applications including corrosion resistance and paint adhesion. Issues remain. In particular, a surface treatment solution (chemical conversion solution) and surface treatment method (coating ground treatment) that provide a high level of electrodeposition coating required for automobile metal structures at a low cost and in a simple process are proposed. However, improvement of the wearability with electrodeposition coating is an important issue.

  The present invention is for solving the above-mentioned problems of the prior art, and specifically provides excellent corrosion resistance and paint adhesion to the surface of a metal material, and also has high removability with electrodeposition coating. A surface treatment liquid to be applied and a surface treatment method are provided. In particular, when applied to an automobile body or this part, it has a high electrodeposition coating performance equivalent to or higher than that of phosphate without drying, and also has appropriate corrosion resistance and paint adhesion, The present invention provides a surface treatment solution for metal structures and a surface treatment method that can control industrial waste such as sludge when industrialized and operate, can be easily controlled, and are economically inexpensive.

The present inventors diligently studied a means for solving the above-described problems of the prior art. As a result, it has been found that the above problem can be solved by using a surface treatment liquid containing a water-soluble tellurium compound and a water-soluble titanium compound and / or a water-soluble zirconium compound.
More specifically, the surface treatment liquid is brought into contact with the metal structure, and a specific film is formed on the metal structure, thereby giving the metal structure excellent reversibility with electrodeposition coating, and The inventors have found a surface treatment method capable of imparting excellent corrosion resistance and paint adhesion, and have completed the present invention. In this method, by appropriately adjusting the composition to be used and the processing conditions, generation of sludge and the like is greatly suppressed when continuously operated.
In particular, in the present invention, it is completely new that the throwing power of electrodeposition coating is greatly improved by depositing tellurium on the surface from at least one tellurium compound selected from water-soluble tellurium compounds. I found it. As a result, the throwing power of the electrodeposition coating can be controlled from the base film. Furthermore, it has been found that high corrosion resistance and paint adhesion can be imparted by simultaneously depositing and attaching a compound selected from two types of titanium compounds and zirconium compounds on the surface to form a composite film.

  That is, the present inventor has intensively studied for the purpose of solving the above-mentioned problems, and has found a solution. That is, the present invention includes the following (1) to (17).

(1) A metal surface treatment liquid containing at least one water-soluble tellurium compound (A) and at least one compound (B) selected from the group consisting of a water-soluble titanium compound and a water-soluble zirconium compound.
(2) Furthermore, at least one water-soluble nitrate compound (C), at least one water-soluble aluminum compound (D), at least one water-soluble zinc compound (E), and at least one fluorine compound The metal surface treatment liquid according to (1), comprising (F).
(3) Content (CA) as tellurium of the water-soluble tellurium compound (A) is 0.05 to 10 mmol / L,
The total content (CB) of the compound (B) as titanium and / or zirconium is 0.1 to 10 mmol / L,
The content (CC) of the water-soluble nitrate compound (C) as a nitrate radical is 1 to 300 mmol / L,
The content (CD) of the water-soluble aluminum compound (D) as aluminum is 0.2 to 200 mmol / L,
The content (CE) of the water-soluble zinc compound (E) as zinc is 0.1 to 100 mmol / L,
The fluorine content (CF) of the fluorine compound (F) satisfies the following formulas (1) and (2):
Formula (1): CF (minimum value) = CA × 10 + CB × 4 + CD × 2
Formula (2): CF (maximum value) = CA × 40 + CB × 7 + CD × 4
And the metal surface treatment liquid as described in (2) whose pH of a treatment liquid is 2.5-5.0.
(4) The metal surface treatment liquid according to any one of (1) to (3), further comprising a cationic water-soluble resin (G).
(5) The metal surface treatment liquid according to any one of (1) to (4), further containing a silane compound (H).
(6) The metal surface treatment liquid according to any one of (1) to (5), further comprising a metal chelating agent (I).
(7) The water-soluble tellurium compound (A) is at least one selected from the group consisting of telluric acid, potassium tellurate, sodium tellurate, telluric acid, potassium tellurite, sodium tellurite, and tellurium dioxide. The metal surface treatment liquid according to any one of (1) to (6), which is a seed.
(8) Compound (B) is titanium sulfate, titanium oxysulfate, titanium ammonium sulfate, titanium nitrate, titanium oxynitrate, titanium ammonium nitrate, fluorotitanic acid, fluorotitanium complex salt, zirconium sulfate, zirconium oxysulfate, ammonium zirconium sulfate. The metal surface treatment according to any one of (1) to (7), which is at least one selected from the group consisting of zirconium nitrate, zirconium oxynitrate, ammonium zirconium nitrate, fluorozirconic acid, and fluorozirconium complex salt liquid.
(9) The water-soluble nitrate compound (C) is at least one selected from the group consisting of titanium nitrate, zirconium nitrate, magnesium nitrate, calcium nitrate, aluminum nitrate, zinc nitrate, strontium nitrate, manganese nitrate, and copper nitrate. , (2) to (8) The metal surface treatment liquid according to any one of (8).
(10) The water-soluble aluminum compound (D) is at least one selected from the group consisting of aluminum nitrate, aluminum sulfate, and aluminum fluoride, according to any one of (2) to (9). Metal surface treatment solution.
(11) The metal surface treatment liquid according to any one of (2) to (10), wherein the water-soluble zinc compound (E) is at least one selected from the group consisting of zinc nitrate and zinc sulfate. .
(12) The fluorine compound (F) is selected from the group consisting of hydrofluoric acid, ammonium fluoride, fluorotitanic acid, fluorotitanium complex, fluorozirconic acid, fluorozirconium complex, aluminum fluoride, and tin fluoride. The metal surface treatment liquid according to any one of (2) to (11), which is at least one kind.
(13) The cationic water-soluble resin (G) is at least one selected from the group consisting of an amino group-containing water-soluble oligomer and a water-soluble polymer, and the content of the resin (G) is 0.001. The metal surface treatment solution according to any one of (4) to (12), which is ˜1 mmol / L.
(14) The silane compound (H) is at least one selected from the group consisting of a silane coupling agent and colloidal silica, and the content of the compound (H) is 0.02 to 20 mmol / L. (5) The metal surface treatment liquid according to any one of (13).
(15) The chelating agent (I) is at least one selected from the group consisting of oxalic acid, tartaric acid, citric acid, malic acid, organic phosphonic acid, nitrilotriacetic acid, and ethylenediaminetetraacetic acid, The metal surface treatment solution according to any one of (6) to (14), wherein the content of I) is 0.001 to 10 mmol / L.
(16) The metal to be treated is composed of at least one metal material selected from the group consisting of a cold-rolled steel plate, an aluminum plate, an aluminum alloy plate, a zinc plate, a zinc alloy plate, a galvanized steel plate, or an alloyed galvanized steel plate. The metal surface treatment liquid according to any one of (1) to (15), wherein the metal surface treatment liquid is a transported vehicle or a part thereof and contains metal ions eluted from the metal to be treated.
(17) Using the metal surface treatment liquid according to any one of (1) to (16), a metal is surface-treated, and an adhesion amount is 0.02 to 2.0 mmol as tellurium on the metal surface. / m ² , and titanium or zirconium or a total of 0.02 to 2.0 mmol / m ² , when converted to a film thickness, a conversion film of 2.0 to 200 nm is formed, washed with water, and deionized with water A metal surface treatment method characterized by subjecting a metal surface to electrodeposition coating without drying.

  ADVANTAGE OF THE INVENTION According to this invention, the surface treatment liquid and surface treatment method which provide the corrosion resistance and coating-material adhesiveness which were excellent on the metal material surface, and also provide the high revolving property with electrodeposition coating can be provided. In particular, when applied to an automobile body or this part, it has a high electrodeposition coating performance equivalent to or higher than that of phosphate without drying, and also has appropriate corrosion resistance and paint adhesion, Can suppress industrial waste such as sludge when industrialized and operated, and can provide a surface treatment solution for metal structures and a surface treatment method that can be controlled easily and economically.

The present invention relates to a novel surface treatment solution (chemical conversion solution) for metal surface treatment and a surface treatment method for imparting excellent corrosion resistance and coating film adhesion to the surface of a metal structure.
First, the surface treatment liquid used in the present invention will be described.
The metal surface treatment liquid according to the present invention contains at least one water-soluble tellurium compound (A) and at least one compound (B) selected from the group consisting of a water-soluble titanium compound and a water-soluble zirconium compound. Preferably, at least one water-soluble nitrate compound (C), at least one water-soluble aluminum compound (D), at least one water-soluble zinc compound (E), and at least one fluorine compound. (F).
Below, each component contained in a metal surface treatment liquid is demonstrated.

<Water-soluble tellurium compound (A)>
The water-soluble tellurium compound (A) used in the present invention is an essential component of the treatment liquid and greatly affects the throwing power of electrodeposition coating.
The water-soluble tellurium compound is not particularly limited as long as it is a compound containing a tellurium atom and soluble in water. For example, at least one compound selected from the group consisting of telluric acid, potassium tellurate, sodium tellurate, telluric acid, potassium tellurite, sodium tellurite, and tellurium dioxide can be used. Of these, telluric acid and telluric acid are more preferable.
The content (CA) of the water-soluble tellurium compound (A) in the treatment liquid of the present invention is preferably in the range of 0.05 to 10 mmol / L as tellurium, that is, in terms of metal tellurium, and 0.1 to 1.0 mmol. The range of / L is more preferable. If it is less than 0.05 mmol / L, the concentration may be low and the tellurium adhesion amount may not be sufficient. On the other hand, when the concentration exceeds 10 mmol / L, the concentration in the treatment liquid is high, and the cost is high, which is not preferable economically. In the case of 10 mmol / L or less, the eutectoid of the water-soluble titanium compound and / or the water-soluble zirconium compound (B) described later proceeds better, and a sufficient amount of titanium or zirconium is contained in the film. Thus, the corrosion resistance is further improved.

<Water-soluble titanium compound and / or water-soluble zirconium compound>
At least one compound (B) selected from the group consisting of a water-soluble titanium compound and a water-soluble zirconium compound used in the present invention is an essential component of the treatment liquid, and this greatly affects the corrosion resistance.
Examples of the compound (B) include titanium sulfate, titanium oxysulfate, titanium ammonium sulfate, titanium nitrate, titanium oxynitrate, titanium ammonium nitrate, fluorotitanic acid, fluorotitanium complex salt, zirconium sulfate, zirconium oxysulfate, ammonium zirconium sulfate, It is preferable to use at least one selected from zirconium nitrate, zirconium oxynitrate, ammonium zirconium nitrate, fluorozirconic acid, and fluorozirconium complex salt. Of these, titanium nitrate, fluorotitanic acid, fluorotitanate, zirconium nitrate, fluorozirconic acid, and fluorozirconic acid salt are more preferable.
The total content (CB) of the compound (B) in the treatment liquid of the present invention is 0.1 to 10 mmol / t as titanium or zirconium or the total thereof, that is, the total in terms of metal titanium or metal zirconium. The range of L is preferable, and the range of 0.5 to 5.0 mmol / L is more preferable. If the concentration is less than 0.1 mmol / L, the concentration is low and the adhesion of zirconium or titanium may not be sufficient, and the excellent corrosion resistance may not be sufficiently exhibited. Moreover, when it exceeds 10 mmol / L, the density | concentration in a process liquid is high, cost increases, and it is not economically preferable.

<Water-soluble nitrate compound (C)>
The treatment liquid of the present invention may contain a water-soluble nitrate compound (C). The water-soluble nitrate compound (C) affects the uniformity of the formed film and affects the final corrosion resistance. It is considered that nitric acid is present at the interface between the treatment liquid and the material during the treatment, suppressing excessive etching and making the film uniform.
As the water-soluble nitrate compound, for example, it is preferable to use at least one selected from titanium nitrate, zirconium nitrate, magnesium nitrate, calcium nitrate, aluminum nitrate, zinc nitrate, strontium nitrate, manganese nitrate, and copper nitrate. Among these, at least one compound selected from titanium nitrate, zirconium nitrate, aluminum nitrate, and zinc nitrate is more preferable.
The content (CC) of the water-soluble nitrate compound (C) in the treatment liquid of the present invention is preferably in the range of 1.0 to 300 mmol / L, more preferably in the range of 20 to 200 mmol / L, as the nitrate radical of the nitrate. . If it is less than 1.0 mmol / L, sufficient effects may not be exhibited, and the final corrosion resistance may be insufficient. In addition, even if it exceeds 300 mmol / L, there is no problem in performance, but the nitrate concentration in the subsequent washing water increases, and the amount of nitrogen in the final wastewater treatment increases, which may lead to eutrophication. It is not preferable.

<Water-soluble aluminum (D)>
The treatment liquid of the present invention may contain water-soluble aluminum (D). Water-soluble aluminum (D) has the effect of suppressing excessive etching and depositing the film efficiently and uniformly.
As the water-soluble aluminum compound, for example, it is preferable to use at least one selected from aluminum nitrate, aluminum sulfate, and aluminum fluoride.
The content (CD) of water-soluble aluminum (D) in the treatment liquid of the present invention is preferably in the range of 0.2 to 200 mmol / L as aluminum, that is, in terms of metal aluminum, and is 1.0 to 20 mmol / L. A range is more preferred. If it is less than 0.2 mmol / L, the sufficient effect is not exhibited, the chemical conversion film may not adhere uniformly and efficiently, and problems such as an increase in processing time may occur. Moreover, even if it exceeds 200 mmol / L, there is no problem in terms of performance, but the concentration in the surface treatment solution is high and the cost is high, which is not economically preferable.

<Water-soluble zinc compound (E)>
The treatment liquid of the present invention may contain a water-soluble zinc compound (E). The water-soluble zinc compound (E) has an effect of increasing the uniform continuity of the film to be formed.
As the water-soluble zinc compound, for example, it is preferable to use at least one selected from zinc nitrate and zinc sulfate.
The content (CE) of the water-soluble zinc compound (E) in the treatment liquid of the present invention is preferably in the range of 0.1 to 100 mmol / L as zinc, that is, in terms of metallic zinc, and is 5.0 to 50 mmol / L. The range of is more preferable. If it is less than 0.1 mmol / L, sufficient effects may not be exhibited, and the uniform continuity of the chemical conversion film may not be sufficient, and as a result, corrosion resistance may not be sufficient. Moreover, when it exceeds 100 mmol / L, the production | generation of a chemical conversion film may be inhibited.

<Fluorine compound (F)>
The treatment liquid of the present invention may contain a fluorine compound (F). The fluorine compound depends on the etching of the material, but has recently been found to have a great influence on the corrosion resistance. Further, it has been found that by appropriately regulating the amount of this fluorine, the generation of sludge is suppressed during continuous operation. In past inventions, etc., it is mentioned that a part contains a fluorine compound, but it puts emphasis on the etching action, and there are very few things that mention improvement in corrosion resistance and stability of processing solution. .
As the fluorine compound, for example, at least one compound selected from hydrofluoric acid, ammonium fluoride, fluorotitanic acid, fluorotitanium complex, fluorozirconic acid, fluorozirconium complex, aluminum fluoride, and tin fluoride is used. It is preferable to do. Of these, hydrofluoric acid and ammonium fluoride are important, and it is preferable to finally adjust the content thereof.

The content (CF) of the fluorine compound (F) in the treatment liquid of the present invention is preferably the content as fluorine, that is, the total fluorine (total fluorine amount) is in the following formula-containing concentration range. That is, the content (CF) of the fluorine compound (F) is selected from at least one compound (B) selected from a water-soluble tellurium compound (A), a water-soluble titanium compound and a water-soluble zirconium compound, and water-soluble aluminum. It is closely related to the concentration with at least one compound (D) and is preferably in the range represented by the following formulas (1) and (2) derived from these contents.
Formula (1): CF (minimum value) = CA × 10 + CB × 4 + CD × 2
Formula (2): CF (maximum value) = CA × 40 + CB × 7 + CD × 4
If the CF (minimum value) is less than the concentration shown in the formula, the etching ability is inferior and partial surface etching (which may etch only a relatively active surface portion) may occur, resulting in uniform coating. The corrosion resistance of the formed film may not be sufficient. In addition, the stability of the treatment liquid is relatively low, and sludge generation may increase during continuous operation of the chemical conversion treatment. Moreover, when CF (maximum value) is exceeded, etching power will become strong and the deposition efficiency of a film | membrane may worsen.
Further, more preferable CF (optimum minimum value) and CF (optimum maximum value) are in the ranges of the following formulas (3) and (4).
Formula (3): CF (optimum minimum value) = CA × 15 + CB × 5.5 + CD × 2
Formula (4): CF (optimum maximum value) = CA × 30 + CB × 6.5 + CD × 4

<PH>
The pH of the treatment liquid of the present invention is not particularly limited, but it is preferable that there is an appropriate range from the viewpoint of the ability to attach electrodeposition coating.
Specifically, the pH of the treatment liquid is preferably in the range of 2.5 to 5.0, and more preferably in the range of 3.0 to 4.5. The pH of the surface treatment solution of the present invention is preferably controlled within the above range not only before being used for the chemical conversion treatment but also when the chemical conversion treatment is continuously operated. When the pH is less than 2.5, the etching power becomes strong and the deposition efficiency of the film may be deteriorated. Moreover, when pH exceeds 5.0, generation | occurrence | production of sludge may increase at the time of a continuous operation.
Moreover, when a compound (B) is a water-soluble titanium compound, pH3.0-3.6 which is a somewhat low pH range is more preferable. When the compound (B) is a water-soluble zirconium compound, pH 3.4 to 4.0 which is a slightly higher pH range is more preferable.
The compound used for pH adjustment is not particularly limited, but it is adjusted with nitric acid belonging to compound (C), hydrofluoric acid belonging to compound (F), ammonium hydrogen carbonate, aqueous ammonia, or the like. It is preferable.

<Cationic water-soluble resin (G)>
The treatment liquid of the present invention may further contain a cationic water-soluble resin (G). The cationic water-soluble resin (G) has the effect of improving the paint adhesion by depositing simultaneously with the essential components to form a film. For example, it is more effective when the electrodeposition coating material applied on the chemical conversion film has poor adhesion.
The cationic water-soluble resin (G) preferably contains at least one selected from amino group-containing water-soluble oligomers and water-soluble polymers. Specifically, amino group-containing oligomers (molecular weight: 2000 to 10000) or amino group-containing polymers (10000 to 30000) such as polyvinyl, polyvinyl phenol, and phenol formalin condensate are preferable. In order not to inhibit the chemical conversion reaction, an oligomer type having a lower molecular weight is preferred.
The content of the cationic water-soluble resin (G) in the treatment liquid of the present invention is preferably in the range of 0.001 to 1 mmol / L. Since this range varies depending on the molecular weight, more specifically, in terms of mass% (ppm), a range of 2 to 100,000 ppm is preferable, and a range of 10 to 400 ppm is more preferable. When the content is too small, the effect of improving paint adhesion is small. Moreover, when there is too much the content, it is economically not preferable, and also a chemical conversion reaction may be inhibited, and it is not preferable.

<Silane compound (H)>
The treatment liquid of the present invention may further contain a silane compound (H). The silane compound precipitates simultaneously with the essential components to form a film, and has the effect of improving the corrosion resistance and paint adhesion. For example, when the electrodeposition coating is inexpensive and has poor adhesion, It is preferable to use a ring agent.
As the silane compound (H), for example, a silane coupling agent or colloidal silica can be used. Specifically, an amino silane coupling agent containing an amino group or an epoxy silane coupling agent containing an epoxy group can be used. Moreover, colloidal silica is also preferable for improving the corrosion resistance. These two types may be used together.
The content of the silane compound (H) in the treatment liquid of the present invention is preferably in the range of 0.02 to 20 mmol / L, more preferably in the range of 0.1 to 0.6 mmol / L. When the content is too small, the effect of improving paint adhesion is small. Moreover, when there is too much content, it is economically unpreferable, and also a chemical conversion reaction may be inhibited, and is unpreferable.

<Metal chelating agent (I)>
The treatment liquid of the present invention may further contain a metal chelating agent (I). The metal chelating agent (I) basically has the effect of increasing the stability of the surface treatment liquid without depositing simultaneously with the essential components to form a film.
When there is a lot of carry-in from the previous process (degreasing) to the chemical conversion process (such as a washing process or a line where the amount of water tends to be insufficient), the pH tends to increase and the stability of the treatment liquid may be impaired. In such a case, the chelating agent has an effect of improving the stability.
The metal chelating agent (I) preferably contains at least one selected from, for example, oxalic acid, tartaric acid, citric acid, malic acid, organic phosphonic acid, NTA (nitrilotriacetic acid) and EDTA (ethylenediaminetetraacetic acid). .
The content of the metal chelating agent (I) in the treatment liquid of the present invention is preferably in the range of 0.001 to 10 mmol / L, more preferably in the range of 0.1 to 0.6 mmol / L. If the content is too small, the stability improving effect is small. Moreover, when there is too much content, it is economically unpreferable, and also a chemical conversion reaction may be inhibited, and is unpreferable.

In addition, about the compound (A)-(F) mentioned above, the same compound can be used, respectively. For example, zinc nitrate can be used both as compound (C) and compound (E), and by adding zinc nitrate to an aqueous solution, nitrate radical and zinc can be simultaneously imparted. Otherwise, aluminum nitrate also acts as compound (C) and compound (E).
Further, fluorozirconic acid and fluorotitanic acid act as the compound (B) and the compound (F).

  As described above, the metal surface treatment liquid of the present invention includes tellurium metal element (content: 0.05 to 10 mmol / L), titanium metal element and / or zirconium metal element (total content: 0.1 to 0.1). 10 mmol / L), nitrate radical (nitrate ion) (content: 1.0 to 300 mmol / L), aluminum metal element (content: 0.2 to 200 mmol / L), zinc metal element (content: 0.1) To 100 mmol / L), and a treatment liquid containing fluorine ions (content: range satisfying formula (1) and formula (2)) is preferable.

<Preparation of surface treatment solution>
The surface treatment liquid of the present invention is prepared by adding each compound as a constituent component to solvent water in any order and stirring and mixing. Preferably, they are mixed in the order of (F), (A), (B), (C), (D), (E). Alternatively, the order in which the pH increases as mixing is more preferable.
The appearance of the surface treatment liquid of the present invention is transparent, and sludge and the like are hardly observed in the treatment liquid after the surface treatment. Specifically, it is preferable that the surface treatment liquid of the present invention is transparent in appearance even after standing for 24 hours under the condition of a predetermined temperature.

<Metal to be treated>
The metal material to be surface-treated by bringing the surface treatment liquid into contact with the present invention is not particularly limited, but is practically used cold-rolled steel plate, aluminum plate and aluminum alloy plate, zinc plate and zinc alloy plate, galvanized steel plate and alloying. A transport vehicle or a part thereof composed of at least one metal material made of a galvanized steel sheet is preferred.

  Among metal materials, a metal structure having a bag structure is preferable. A metal structure having a bag structure is a metal material having a complicated shape typified by an automobile body, and a portion where an electrodeposition coating film is difficult to form even if a cationic electrodeposition coating is applied. It means a metal structure having a structural part). Examples of metal structures having a bag structure include automobile bodies, automobile parts, building materials, construction machine parts, transport machine parts, steel furniture, and the like.

<Surface treatment method>
The surface treatment of the present invention is performed by bringing the treatment liquid into contact with a metal member or a metal structure. In doing so, the surface of the metal to be contacted must be clean. Oil, dirt, or metal powder (caused by wear or molding) must be removed. Although it does not restrict | limit especially as a method to clean, Industrially common alkali washing | cleaning etc. can be used. Next, the surface treatment liquid of the present invention is brought into contact with the surface of the metal which has been washed with water and rinsed with an alkali component or the like.
The method of bringing the treatment liquid of the present invention into contact with a metal member or metal structure is not particularly limited, and may be a method applied in a normal chemical conversion treatment method. For example, a spray treatment method, an immersion treatment method, a pouring method may be used. Treatment methods and electrolytic treatment methods may be mentioned.
Of these, the immersion treatment method is preferred. This is because a film containing tellurium, titanium and / or zirconium can be formed on the entire surface of the metal material relatively easily.

  Although the temperature which performs surface treatment (chemical conversion reaction) is not specifically limited, 30-60 degreeC is preferable. The reaction time is generally in the range of 2 to 600 seconds, although it depends on the metal material, the concentration of the treatment liquid, and the treatment temperature. In the case of a complex structure typified by an automobile body, liquid replacement inside the bag structure is necessary, so that the immersion contact is generally performed for 30 to 120 seconds. If the liquid replacement is possible, there is no problem even with a surface treatment method such as spraying.

  It is preferable to wash with water after the surface treatment. Moreover, it is preferable to wash with deionized water. It is preferable to wash with deionized water after washing with water. The washing method is not particularly limited, and a conventionally known method such as a dipping method or a spray method can be applied. After washing with water, it may be dried or not dried.

Even if the treatment liquid of the present invention contains metal ions eluted from the metal during continuous operation of the surface treatment, there is no problem.
For example, when a metal structure made of cold-rolled steel sheet is surface-treated, iron ions gradually increase in the treatment liquid, but if the content of each compound as a component is controlled within the above range, sludge Such a problem does not occur. In the case of a normal automobile body, there is a natural take-out of the surface treatment liquid due to the transportation of the automobile body, so that the concentration of eluted metal ions from the automobile body reaches a steady state at a relatively low concentration of less than 100 mass ppm. It is preferable to positively remove these eluted metal ions from the system by a centrifugal separator, filtering with various membranes, or the like.
When a metal structure made of galvanized steel sheet or aluminum is surface-treated, the eluted metal ions can be an essential component of the present invention, so that the treatment liquid of the present invention can be used more effectively. The surface-treated metal structure is washed with water, then with deionized water, and then subjected to electrodeposition without drying.

<Chemical conversion coating>
In the treatment method of the present invention, the amount of conversion coating on the surface of a metal member or metal structure is 0.02 to 2.0 mmol / m ² (more preferably 0.05 to 0.5 mmol / m ^{2 in} terms of metal tellurium). ² ) and titanium or zirconium or the total thereof is preferably 0.02 to 2.0 mmol / m ² (more preferably 0.1 to 1.0 mmol / m ² ), It is preferable to form a film having a thickness of 2.0 to 200 nm. If the amount of tellurium deposited is less than 0.02 mmol / m ² , the effect of improving throwing power may not be sufficient. Further, even if the amount of tellurium deposited exceeds 2 mmol / m ² , there is no particular problem. However, since these are expensive, they are not economically preferable.
In addition, the preferable range of the adhesion amount of the metal mentioned above changes with materials to apply. In cold-rolled steel sheets, a higher adhesion amount is required. Next, according to the alloyed galvanized steel sheet and the aluminum material, sufficient performance is exhibited even at a low adhesion amount. In addition, it is considered that tellurium basically exists as a metal, an oxide, or a hydroxide. Although the properties differ slightly depending on the material of the metal structure, tellurium basically exists on the surface of the metal as a semiconductor, controls hydrogen gas generation appropriately during electrodeposition coating, and adheres between the coating and the deposited paint. It is considered that the resistance of the electrodeposition film component deposited as a result is increased and the throwing power is improved. For this reason, it is preferable that tellurium exists on the outermost surface of the film.

If titanium or zirconium or the total amount thereof is less than 0.02 mmol / m ² , the amount of adhesion is small and the corrosion resistance may not be sufficient. Moreover, when it adheres exceeding ² mmol / m <2>, although corrosion resistance does not have a problem in particular, processing cost becomes high and is not economically preferable.
In terms of film thickness, the film has a range of 2 to 200 nm, and a range of 20 to 100 nm is more preferable. Titanium and / or zirconium are also considered to be basically present as oxides and hydroxides. Titanium and / or zirconium are considered to be factors that exhibit high corrosion resistance because they have basically high barrier properties and are strong in acid resistance and alkali resistance.

<Electrodeposition coating>
The surface of the metal member or metal structure having the chemical conversion film described above can be subjected to cationic electrodeposition coating. In the present invention, such a cationic electrodeposition coating exhibits good coating coverage.
Conventionally known methods can be applied as the cationic electrodeposition coating.
For example, a cationic electrodeposition coating composition containing an amine-added epoxy resin as a coating material and a blocked polyisocyanate curing agent as a curing component is used, and the coated metal material of the present invention is immersed therein. In addition, the metal material with a film of the present invention may be dried before the immersion, or may be immersed in the paint without being dried.

And the temperature of a coating material is hold | maintained at about 26-30 degreeC, for example, and a voltage is applied to the metal member and metal structure with a film | membrane obtained, for example using the rectifier, in the state which stirred the coating material with the stirrer if desired. . The electrolysis conditions are appropriately selected depending on the paint used, and may be conventional general conditions. For example, first, a voltage is linearly applied from 0 V to 200 V in the cathode direction over 30 seconds, and then held at 200 V for 150 seconds.
After coating the surface of the metal member or metal structure with a coating in this way, it is washed with water and then the coating film is baked. For example, baking is performed at 170 ° C. for 20 minutes to form a coating film.

  The coating film of the obtained coated metal material preferably has an average thickness of 1 to 50 μm, more preferably 5 to 40 μm, and even more preferably 7 to 25 μm. Moreover, it is preferable that the thickness of the thinnest part is 7 μm or more. If the minimum film thickness is thin, the corrosion prevention effect is not sufficiently exhibited. Furthermore, the thickness of the thickest part is preferably 40 μm or less, and more preferably 25 μm or less. If the maximum film thickness is large, the roughness of the coating film surface increases, which causes problems in appearance and is disadvantageous economically.

Here, the thickness of the coating film is measured using an electromagnetic film thickness meter or an eddy current film thickness meter. When the coating film is formed on the surface of a magnetic metal material (iron, iron-based alloy, etc.), it is measured using an electromagnetic film thickness meter. When the coating film is formed on the surface of a non-magnetic metal material (aluminum, aluminum alloy, etc.), measurement is performed using an eddy current film thickness meter.
The average thickness is calculated | required by measuring several arbitrary places of a coating film by these.

Examples and comparative examples relating to the metal surface treatment liquid and the treatment method according to the present invention will be described below, and novelty, inventive step and usefulness thereof will be described.
First, a metal plate, a pretreatment method (cleaning) of the metal plate, a surface treatment method, and an electrodeposition coating method will be described. Next, various test methods and evaluation methods for each metal plate will be described. Next, the composition of the surface treatment liquid will be described later. In addition, the result of various test methods (evaluation method) was put together in Tables 1-3, and was shown.

<Metal plate>
The metal material is made of cold-rolled steel plate [70 × 150 × 0.8 mm; SPCC (JIS 3141) manufactured by Partec Co., Ltd.], galvannealed steel plate [70 × 150 × 0.8 mm; SGCC manufactured by Partec Co., Ltd. F06 MO (JIS G3302)] and aluminum alloy plate [70 × 150 × 1.0 mm; A5052P (JIS 4000) manufactured by Partec Co., Ltd.] were used. Hereinafter, the cold rolled steel sheet is abbreviated as SPC, the galvannealed steel sheet is abbreviated as GA, and the aluminum alloy sheet is abbreviated as AL.

<Cleaning method>
By using a degreasing agent [Fine Cleaner E2001 made by Nihon Parkerizing Co., Ltd. (A agent 13 g / L, B agent 7 g / L)], the surface of each metal plate is heated to 40 ° C. and sprayed for 120 seconds. Degreased. Then, it spray-washed for 30 seconds, surface-treated using the surface treatment liquid, and formed the chemical conversion film. In addition, when processing the following box, although the said degreasing agent was used, it was set as immersion treatment and time was 180 seconds. Washing with water was also carried out, and the time was set to 60 seconds, and rocked well.

<Surface treatment method>
A surface treatment solution having the composition described below was prepared, and the mixture was stirred for 1 hour at a predetermined temperature in order to confirm the degree of stability such as pH and the occurrence of precipitation, and allowed to stand, and the appearance of the surface treatment solution was observed (the initial appearance and Called). Then, the surface treatment of each metal plate or the following box was performed by any of the following surface treatment methods (1) to (3). After the surface treatment, each metal plate was washed with running tap water (room temperature, 30 seconds), and further washed with deionized water (room temperature, 30 seconds).
Surface treatment method (1)
Processing temperature: 45 ° C
Treatment time: 90 seconds Contact method: Immersion surface treatment method (2)
Processing temperature: 35 ° C
Treatment time: 120 seconds Contact method: Immersion surface treatment method (3)
Processing temperature: 50 ° C
Treatment time: 45 seconds Contact method: Immersion

<Electrodeposition coating method>
Electrodeposition coating [GT-10HT, manufactured by Kansai Paint Co., Ltd.] was applied to the metal plate on which the above-mentioned chemical film was formed by washing with running water and deionized water and not drying. After the coating film was deposited, it was washed with water and baked at 170 ° C. for 20 minutes for electrodeposition coating to form a coating film. The film thickness of the coating film was adjusted to 20 μm by controlling the voltage.

<Adhesion amount>
The amount of each metal adhering on the treated metal plate after the surface treatment was quantified with a fluorescent X-ray analyzer (manufactured by Rigaku Corporation, System 3270E). The surface of the metal plate was washed with water, washed with deionized water, dried with cold air, and subjected to the adhesion amount measurement.

<Chemical film thickness>
The film thickness of the chemical conversion coating on the treated metal plate after the surface treatment was quantified with a surface analyzer (ESCA-850M manufactured by Shimadzu Corporation, sputtering rate: 80 nm / min). The chemical conversion film was subjected to argon sputtering, and the time until the base metal was 70 atomic% was defined as the film. The film thickness was obtained in terms of the sputtering time. In addition, the processing metal plate used what was used for said adhesion amount measurement.

<Film thickness of electrodeposition coating>
The film thickness of the coating film on the metal coated plate after electrodeposition coating was measured with a commercially available electromagnetic induction type film thickness meter (LZ-200, manufactured by Kett Scientific Laboratory).

<Coating adhesion>
A grid was cut into the electrodeposited metal coated plate, immersed in boiling water for 1 hour, wiped with water, and then peeled off. The state of the grid after peeling was observed. The number of cells was 100, and the number that did not peel was measured. Therefore, 100 is the best and 0 is the worst.

<Corrosion resistance>
A cross-cut was performed on the electrodeposited metal coated plate, a salt spray test (JIS-Z2371) was performed, and the one-side swollen width of the cross-cut portion after 1000 hours was evaluated. Generally, 3 mm or less is good for cold-rolled steel sheets, 2 mm or less is a very good level, 1.2 mm or less is a good level for alloyed galvanized steel sheets, and 0.5 mm or less is a good level for aluminum alloy sheets It becomes.

<Testing method for electrodeability with electrodeposition coating>
Four metal plates 12 to 15 of the same kind were prepared, and a hole 10 having a diameter of 8 mm was formed in three of the metal plates 12 to 14 among them. The position of the hole 10 was set at the center in the short side direction of the metal plate and 50 mm from the lower end in the long side direction. As shown in FIG. 1, the four metal plates 12 to 15 were assembled with a clearance of 20 mm. The four metal plates 12-15 are arrange | positioned in parallel, respectively. Glue each of the two vinyl chloride plates (21, 22) with adhesive tape so that they touch all the long sides of the four metal plates 12-15, and then touch one of the short sides. The vinyl chloride plate (23) was adhered with an adhesive tape. In this way, the four-box 1 was assembled.
The assembled box was surface-treated by any one of the surface treatment methods (1) to (3), and electrodeposition coating was performed without drying. At that time, the four-sheet box 1 and the counter electrode 2 were arranged as shown in FIGS. That is, the four-box was arranged so that the metal plate 12 with the holes 10 formed on the side close to the counter electrode 2. 2 shows a cross-sectional view at the center in the short side direction of the metal plate, and FIG. 3 is a perspective view. As the counter electrode, a stainless steel plate (SUS304) 70 × 150 × 0.55 mm whose one surface was sealed with an insulating tape was used. The liquid level of the electrodeposition paint was controlled at a position where the metal plates 12 to 15 and the counter electrode were immersed 90 mm. The electrodeposition coating was carried out while maintaining the temperature of the electrodeposition paint at 28 ° C. and stirring with a stirrer. After all the four metal plates 12 to 15 were short-circuited (FIG. 2), the coating film was electrolytically deposited by a cathodic electrolysis method using a rectifier with the counter electrode as an anode. Electrolytic conditions were such that a voltage was applied linearly from 0 to 230 V over 30 seconds, and then maintained at 230 V for 150 seconds. After the electrolysis, each of the metal plates 12 to 15 was washed with water and baked at 170 ° C. for 20 minutes to form a coating film. The counter electrode side of the metal plate 12 closest to the counter electrode is the A surface, the counter electrode side of the metal plate 15 furthest from the counter electrode is the G surface, the coating thickness of the A surface and the G surface is measured, and the ratio of A / G is determined. It was used as an indicator of the throwing power of electrodeposition coating. Generally, it is judged that the ratio is preferably 2.5 or less, and 2.0 or less is an excellent level.
In addition, the film thickness of the coating film formed on the A surface and the G surface is measured using an electromagnetic film thickness meter (when the metal plate is SPC or GA) or an eddy current film thickness meter (when the metal plate is Al). Measured. The coating thickness on the A and G surfaces was the average of the measurement results at 10 randomly selected locations.

<Sludge generation test>
In order to evaluate the operability of industrialization of surface treatment, a sludge generation test was conducted. First, the initial appearance of the surface treatment liquid was checked. Then, the surface treatment liquid 1L was used and the said metal plate was continuously surface-treated for 10 minutes. Each component due to liquid loss (carrying out) by chemical conversion coating and surface treatment was appropriately replenished so as to keep the initial value. And the surface treatment liquid after surface treatment was left still at 40 degreeC for 48 hours, and the state (turbidity etc.) and sediment (sludge) of the subsequent surface treatment liquid were determined visually. It is preferable that no sludge is generated.

Example 1
A surface treatment liquid 1 having the following composition was prepared, and the surface treatment method (1) was applied to the surface treatment of the above-mentioned box produced using each of the three types of metal plates and the three types of metal plates, and then the chemical conversion film. Formed. The preparation of the surface treatment liquid 1 is carried out by adding the following components (A) to (F) to water (F), (A), (B), (D), (E) They were added in order, and finally diluted with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film.
Surface treatment liquid 1
(A): Telluric acid: 0.2 mmol / L
(B): fluorozirconic acid: 1.1 mmol / L
(C): nitrate radical according to (D): 55.5 mmol / L
(D): Aluminum nitrate: 18.5 mmol / L
(E): Zinc sulfate: 7.7 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 65 mmol / L
(G) (H) (I): None pH: 4.0 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 43.4 mmol / L, and CF (maximum value) is calculated to be 89.7 mmol / L.
In addition, content of a compound (A) represents content as tellurium. Compound (B) represents titanium and zirconium or the total content thereof. Content of a compound (C) represents content as a nitrate radical. Content of a compound (D) represents content as aluminum. The content of the compound (E) represents the content as zinc. The content of the compound (F) represents the content as fluorine. The description of the following examples is also the same.

(Example 2)
In the same procedure as in Example 1, a surface treatment liquid 2 having the following composition was prepared, and in the surface treatment method (3), three types of metal plates and three types of metal plates were used. Surface treatment was performed. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 2
(A): Potassium tellurite: 0.2 mmol / L
(B): fluorozirconic acid: 1.1 mmol / L
(C): nitrate nitrate by magnesium nitrate and (D) and (E): 150 mmol / L
(D): Aluminum nitrate: 5.6 mmol / L
(E): Zinc nitrate: 46.2 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 28 mmol / L
(G) (H) (I): None pH: 2.5 Adjusted with aqueous ammonia CF (minimum value) is calculated as 17.6 mmol / L, and CF (maximum value) is calculated as 38.1 mmol / L.

(Example 3)
In the same procedure as in Example 1, a surface treatment liquid 3 having the following composition was prepared, and in the surface treatment method (2), three types of metal plates and three types of metal plates were used. Surface treatment was performed. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 3
(A): Sodium tellurite: 0.2 mmol / L
(B): Zirconium nitrate: 3.3 mmol / L
(C): nitrate radical according to (B) and (E): 28.6 mmol / L
(D): Aluminum sulfate: 9.3 mmol / L
(E): Zinc nitrate: 7.7 mmol / L
(F): Total fluorine of hydrofluoric acid: 60 mmol / L
(G) (H) (I): None pH: 3.5 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 33.8 mmol / L, and CF (maximum value) is calculated to be 68.3 mmol / L.

Example 4
In the same procedure as in Example 1, a surface treatment liquid 4 having the following composition was prepared, and in the surface treatment method (1), three kinds of metal plates and three kinds of metal plates were used. Surface treatment was performed. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment solution 4
(A): Tellurium dioxide: 0.1 mmol / L
(B): Fluorozirconic acid: 0.5 mmol / L
(C): Magnesium nitrate: nitrate root by 20.6 mmol / L: 41.2 mmol / L
(D): Aluminum sulfate: 2.8 mmol / L
(E): Zinc sulfate: 46.2 mmol / L
(F): Total fluorine of ammonium fluoride and (B): 17 mmol / L
(G) (H) (I): None pH: 3.0 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 8.6 mmol / L, and CF (maximum value) is calculated to be 18.7 mmol / L.

(Example 5)
In the same procedure as in Example 1, a surface treatment solution 5 having the following composition was prepared, and in the surface treatment method (2), three types of metal plates and three types of metal plates were used. Surface treatment was performed. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment solution 5
(A): Telluric acid: 1.0 mmol / L
(B): Fluorotitanic acid: 0.5 mmol / L
(C): nitrate nitrate by magnesium nitrate and (E): 30 mmol / L
(D): Aluminum sulfate: 9.3 mmol / L
(E): Zinc nitrate: 7.7 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 68 mmol / L
(G) (H) (I): None pH: 3.0 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 30.6 mmol / L, and CF (maximum value) is calculated to be 80.7 mmol / L.

(Example 6)
In the same procedure as in Example 1, a surface treatment liquid 6 having the following composition was prepared, and in the surface treatment method (1), three types of metal plates and three types of metal plates were used. Surface treatment was performed. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 6
(A): Tellurite: 0.2 mmol / L
(B): Titanium sulfate: 1.9 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid: 38 mmol / L
(G) (H) (I): None pH: 2.5 Adjustment with aqueous ammonia CF (minimum value) is calculated to be 31.8 mmol / L, and CF (maximum value) is calculated to be 65.7 mmol / L.

(Example 7)
A surface treatment liquid 7 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (A) to (G) are added to water in the order of (F), (A), (B), (D), (E), and (G) with respect to 80% of the total amount of water. At the end, and was diluted with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 7
(A): Telluric acid: 0.2 mmol / L
(B): fluorozirconic acid: 1.1 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 44 mmol / L
(G): Polyvinylphenol aminated product (average molecular weight 10,000): 0.02 mmol / l
(H) (I): None pH: 3.5 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 28.6 mmol / L, and CF (maximum value) is calculated to be 60.1 mmol / L.

(Example 8)
A surface treatment liquid 8 having the following composition was prepared, and surface treatment of the box produced using each of the three metal plates and the three metal plates was performed by the surface treatment method (1). In preparation, the following components (A) to (F) and (H) are added to water for (F), (A), (B), (D), (E), (H ) In this order, and finally, the volume was made up with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 8
(A): Telluric acid: 1.0 mmol / L
(B): fluorozirconic acid: 3.3 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 75 mmol / L
(G): None (H): Aminopropyltriethoxysilane (molecular weight 264.5): 0.4 mmol / L
(I): None pH: 4.0 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 45.4 mmol / L, and CF (maximum value) is calculated to be 107.5 mmol / L.

Example 9
A surface treatment liquid 9 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (A) to (F) and (I) are added to water for (F), (I), (A), (B), (D), (E ) In this order, and finally, the volume was made up with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 9
(A): Tellurite: 1.0 mmol / L
(B): fluorozirconic acid: 3.3 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 75 mmol / L
(G) (H): None (I): 1-hydroxyethylidene-1,1-diphosphonic acid: 1 mmol / L
pH: 3.0 Adjusted with aqueous ammonia CF (minimum value) is calculated to be 45.4 mmol / L, and CF (maximum value) is calculated to be 107.5 mmol / L.

(Example 10)
A surface treatment liquid 10 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (A) to (G) and (I) are added to water for (F), (I), (A), (B), (D), (E ) And (G) were added in this order, and finally it was made up with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 10
(A): Telluric acid: 1 mmol / L
(B): fluorozirconic acid: 1.1 mmol / L
(C): nitrate radical according to (D) and (E): 67.1 mmol / L
(D): Aluminum nitrate: 1.9 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of ammonium fluoride and (B): 35 mmol / L
(G): Polyvinylphenol aminated product (average molecular weight 10,000): 0.01 mmol / l
(H) None (I): Tartaric acid: 0.3 mmol / L
pH: 4.5 Adjustment with ammonia water It is calculated that CF (minimum value) is 18.2 mmol / L and CF (maximum value) is 55.3 mmol / L.

(Example 11)
A surface treatment liquid 11 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (A) to (H) are added to water for (F), (A), (B), (D), (E), (G), (H ) In this order, and finally, the volume was made up with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and the box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 11
(A): Tellurium dioxide: 0.1 mmol / L
(B): Fluorotitanic acid: 4.2 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 61 mmol / L
(G): Polyvinylphenol aminated product (average molecular weight 10,000): 0.01 mmol / l
(H): Colloidal silica (molecular weight 60): 16 mmol / L
(I): None pH: 2.5 Adjusted with aqueous ammonia CF (minimum value) is calculated as 40 mmol / L, and CF (maximum value) is calculated as 77.8 mmol / L.

Example 12
A surface treatment liquid 12 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (A) to (F), (H), and (I) are added to water for 80% of the water (F), (I), (A), (B), (D ), (E), and (H) were added in this order, and finally it was made up with water and stirred at room temperature for 20 minutes. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and the box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 12
(A): Telluric acid: 1 mmol / L
(B): fluorozirconic acid: 1.7 mmol / L
(C): nitrate radical according to (D) and (E): 95 mmol / L
(D): Aluminum nitrate: 11.1 mmol / L
(E): Zinc nitrate: 30.8 mmol / L
(F): Total fluorine of hydrofluoric acid and (B): 71 mmol / L
(G): None (H): Colloidal silica (molecular weight 60): 4 mmol / L
And aminosilane coupling agent (A0876, manufactured by Tokyo Chemical Industry Co., Ltd.): 0.5 mmol / L
(I): Malic acid: 0.8 mmol / L
pH: 3.0 Adjusted with aqueous ammonia CF (minimum value) is calculated as 39 mmol / L, and CF (maximum value) is calculated as 96.3 mmol / L.

(Comparative Example 1)
A surface treatment liquid 13 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (B) to (F) are added to water in the order of (F), (B), (D), and (E) with respect to 80% of the total amount of water. And stirred for 20 minutes at room temperature. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 13
(A): None (B): Fluorozirconic acid: 5 mmol / L
(C): nitrate radical according to (D): 20 mmol / L
(D): Magnesium nitrate: 20 mmol / L
(E): Zinc sulfate: 0.4 mmol / L
(F): Fluorotitanic acid (total fluorine): 32 mmol / L
(G): None pH: 3.6 Adjusted with ammonia water

(Comparative Example 2)
A surface treatment solution 14 having the following composition was prepared, and surface treatment was performed on the three types of metal plates and the box produced using each of the three types of metal plates by the surface treatment method (1). In preparation, the following components (B) to (F) are added to water in the order of (B) and (E) with respect to 80% of the total amount of water, finally diluted with water and stirred at room temperature for 20 minutes. did. Next, the pH was adjusted by heating to a predetermined temperature. The metal plate and box after the surface treatment were washed with water, washed with deionized water, and electrodeposition-coated by the above method and conditions without drying to form a coating film. Thereafter, the evaluation described above was performed.
Surface treatment liquid 14
(A): None (B): Fluorotitanic acid: 1.0 mmol / L
(C): nitrate radical according to (E): 0.4 mmol / L
(D): None (E): Zinc nitrate: 0.4 mmol / L
(F): Total fluorine according to (B): 1 mmol / L
(G): None pH: 2.3 Adjusted with nitric acid

(Comparative Example 3)
Three kinds of metal plates and three kinds of metal plates using a 2% aqueous solution of registered trademark Allodin 404 (corresponding to JP-A-52-131937), which is a commercially available non-chromate chemical, for 30 seconds at 40 ° C. Each of these was sprayed onto a box produced using a surface treatment to form a chemical conversion film. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 4)
A surface treatment solution 15 (corresponding to Patent Document 8) composed of iron hexacyanoate 2 g / L, fluorotitanic acid 1 g / L, and cobalt nitrate 1 g / L is prepared, and this is subjected to three kinds of metal plates at 40 ° C. for 60 seconds. And the box produced using each of 3 types of metal plates was immersed, surface treatment was performed, and a chemical conversion film was formed. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 5)
(1) Titanium sulfate 1 mmol / L, (2) Hydrofluoric acid equivalent to 6 times mole of titanium sulfate, (3) Calcium nitrate 0.2 mmol / L, (4) Aluminum nitrate 0.2 mmol / L, ( 5) After preparing a surface treatment liquid (corresponding to Patent Document 10) containing nitrate ions (added as described above) and adjusting the pH to 3.8, three kinds of metal plates and three kinds at 40 ° C. for 60 seconds. Boxes prepared using the respective metal plates were dipped and subjected to surface treatment to form a chemical conversion film. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 6)
Zirconium 1000 mass ppm (added as fluorozirconic acid), zinc 1000 mass ppm (added as zinc nitrate), magnesium 500 mass ppm (added as magnesium nitrate), titanium 100 mass ppm (added as fluorotitanic acid), indium 3 Mass ppm (added with indium nitrate) and 800 mass ppm of nitroguanidine were added to water in this order, and stirred and mixed at room temperature to prepare a surface treatment solution, which was adjusted to pH 4.5 with aqueous ammonia. In this treatment solution, three types of metal plates and boxes prepared using the three types of metal plates were respectively immersed at 40 ° C. for 60 seconds, and surface-treated to form a chemical conversion film (Patent Document 15). Equivalent to Example 14). Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 7)
Zirconium 200 mass ppm (added with fluorozirconic acid), zinc 500 mass pppm (added with zinc nitrate), silica 200 mass ppm (added as Snowtex N), and ammonium persulfate 200 mass ppm were added to water in this order. The surface treatment solution was prepared by stirring and mixing at room temperature, and adjusted to pH 4.0 with ammonia water. In this treatment solution, three types of metal plates and boxes prepared using the three types of metal plates were respectively immersed at 40 ° C. for 60 seconds, and surface-treated to form a chemical conversion film (Patent Document 15). Equivalent to Example 3). Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 8)
Zirconium 500 mass ppm (added as fluorozirconic acid), magnesium 1000 mass ppm (added as magnesium nitrate), calcium 500 mass ppm (added as calcium nitrate), and sodium chlorate 100 mass ppm were added to water in this order. A surface treatment solution was prepared by stirring and mixing at room temperature, and adjusted to pH 4.5 with aqueous ammonia. In this treatment solution, three types of metal plates and boxes prepared using the three types of metal plates were respectively immersed at 25 ° C. for 60 seconds, and surface-treated to form a chemical conversion film (Patent Document 15). Equivalent to Example 10). Next, the metal plate and box after the surface treatment were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying to form a coating film.

(Comparative Example 9)
Using a 5% aqueous solution of registered trade name Palbond L3020, which is a zinc phosphate-based chemical conversion agent, immersing each of the three types of metal plates and the boxes prepared using the three types of metal plates at 35 ° C. for 120 seconds. Then, a chemical conversion film was formed by surface treatment. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film.

(Comparative Example 10)
Zirconic acid 40% as zirconium, 500 mass ppm in terms of metal element, 3-aminopropyltriethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd., “KBE903”] as an adhesion-imparting agent, 200 ppm by mass in active ingredient concentration, stabilized HIDA (hydroxyethyliminodiacetic acid) as an agent was added to 200 mass ppm, and the pH was adjusted to 4 with sodium hydroxide to obtain a surface treatment solution. As KBE903, 5 parts by mass of KBE903 is uniformly dropped over 60 minutes from a dropping funnel into a mixed solvent of 45 parts by mass of deionized water and 50 parts by mass of ethanol (solvent temperature: 25 ° C.). Was reacted for 24 hours at 25 ° C. under a nitrogen atmosphere, and then the ethanol was evaporated by reducing the pressure of the reaction solution. The hydrolyzed polycondensate of KBE903 containing 5% active ingredient (hereinafter referred to as “KBE903 polycondensate A”). Was used. The ORP (redox potential) of the obtained surface treatment liquid is 308 mV, and the ratio of the content of zirconium element to the total content of silicon element contained in aminosilane and / or the hydrolysis polycondensate of aminosilane (Zr / Si) Ratio) was 20. The surface treatment was performed by immersing each of the three types of metal plates and the three types of metal plates in the surface treatment solution at 40 ° C. for 60 seconds, and surface-treating to form a chemical conversion film. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film. (Based on Patent Document 36)

(Comparative Example 11)
N-2- (aminoethyl) -3-aminopropyltrimethoxysilane [manufactured by Shin-Etsu Chemical Co., Ltd., "KBM603"] as an adhesiveness imparting agent is 200 ppm by mass as an active ingredient concentration, and aspartic acid is 100 as a stabilizer. A surface treatment solution was prepared according to the method described in Comparative Example 10 except that ppm was used and 250 ppm by mass of zirconium in terms of metal element was used. The KBM603 is a hydrolyzed polycondensate of KBM603 (hereinafter referred to as “KBM603 polycondensate”) that has been hydrolyzed and polycondensed in advance in the same manner as in Comparative Example 11 except that KBM603 is used instead of KBE903. Used). The ORP of the surface treatment solution was 356 mV, and the Zr / Si ratio was 10. In the surface treatment, a chemical conversion film was formed under the same conditions as described in Comparative Example 10. Next, the surface-treated metal plate and box were washed with water, washed with deionized water, and subjected to electrodeposition coating under the above method and conditions without drying, thereby forming a coating film. (Based on Patent Document 36)

(Comparative Example 12)
Only cleaning (degreasing only) was performed, electrodeposition coating was performed without surface treatment, and a coating film was formed.

Tables 1 to 3 show the test and evaluation results of the surface treatment coatings of Examples 1 to 12 and Comparative Examples 1 to 12. Table 1 shows the results for the cold-rolled steel sheet, Table 2 for the galvannealed steel sheet, and Table 3 for the aluminum alloy sheet.
In Tables 1 to 3, “(A) adhesion amount” represents the adhesion amount (mmol / m ² ) of tellurium (Te) in the film. Further, in Tables 1 to 3, “(B) adhesion amount” represents the adhesion amount (mmol / m ² ) of titanium and / or zirconium in the film. “Chemical conversion film thickness” represents the film thickness of the obtained film.
The “coating performance” is a result of evaluation using a metal plate in which the film thickness of the coating film is adjusted to 20 μm by the above electrodeposition method.
“Chemical conversion film characteristics” are the results of evaluation using a metal plate after the above-mentioned box is subjected to chemical conversion treatment.

In Tables 1 to 3, it was found that, in any metal plate, in the prior art, the throwing power of the electrodeposition coating was insufficient except when phosphate was used. In addition, when a sludge generation test is carried out, there are many cases in which sediment is generated, which has a problem in operability (productivity) when industrialized.
On the other hand, in the surface treatment liquid and the surface treatment method of the present invention (Examples 1 to 12), excellent removability with electrodeposition coating can be imparted, and in addition, the corrosion resistance and paint adhesion are excellent, and the operation. It was found to be excellent in performance.

It is a sketch of the box used for the throwing power test of electrodeposition coating (four-sheet box test). It is explanatory drawing which shows the evaluation method of the revolving property with electrodeposition coating. It is another explanatory drawing which shows the evaluation method of the surrounding property with electrodeposition coating.

Explanation of symbols

1 Box 2 Counter electrode 10 Hole 12 Test plate No. 1 (outside: A side)
13 Test plate No. 2
14 Test plate No. 3
15 Test plate No. 4 (Inside: G side)
21 Side divider (vinyl chloride plate)
22 Side divider (vinyl chloride plate)
23 Bottom partition plate (vinyl chloride plate)

Claims (17)

  A metal surface treatment liquid comprising at least one water-soluble tellurium compound (A) and at least one compound (B) selected from the group consisting of a water-soluble titanium compound and a water-soluble zirconium compound.   Furthermore, at least one water-soluble nitrate compound (C), at least one water-soluble aluminum compound (D), at least one water-soluble zinc compound (E), and at least one fluorine compound (F). The metal surface treatment liquid of Claim 1 containing these. Content (CA) as tellurium of the water-soluble tellurium compound (A) is 0.05 to 10 mmol / L,
The total content (CB) of the compound (B) as titanium and / or zirconium is 0.1 to 10 mmol / L,
The content (CC) of the water-soluble nitrate compound (C) as a nitrate radical is 1 to 300 mmol / L,
The content (CD) of the water-soluble aluminum compound (D) as aluminum is 0.2 to 200 mmol / L,
The content (CE) of the water-soluble zinc compound (E) as zinc is 0.1 to 100 mmol / L,
The fluorine content (CF) of the fluorine compound (F) satisfies the following formulas (1) and (2):
Formula (1): CF (minimum value) = CA × 10 + CB × 4 + CD × 2
Formula (2): CF (maximum value) = CA × 40 + CB × 7 + CD × 4
And the metal surface treatment liquid of Claim 2 whose pH of a treatment liquid is 2.5-5.0.   Furthermore, the metal surface treatment liquid of any one of Claims 1-3 containing cationic water-soluble resin (G).   Furthermore, the metal surface treatment liquid of any one of Claims 1-4 containing a silane compound (H).   Furthermore, the metal surface treatment liquid of any one of Claims 1-5 containing metal chelating agent (I).   The water-soluble tellurium compound (A) is at least one selected from the group consisting of telluric acid, potassium tellurate, sodium tellurite, telluric acid, potassium tellurite, sodium tellurite, and tellurium dioxide. The metal surface treatment liquid according to any one of claims 1 to 6.   The compound (B) is titanium sulfate, titanium oxysulfate, titanium ammonium sulfate, titanium nitrate, titanium oxynitrate, ammonium ammonium nitrate, fluorotitanic acid, fluorotitanium complex, zirconium sulfate, zirconium oxysulfate, zirconium ammonium sulfate, zirconium nitrate. The metal surface treatment liquid according to any one of claims 1 to 7, which is at least one selected from the group consisting of zirconium oxynitrate, ammonium zirconium nitrate, fluorozirconic acid, and a fluorozirconium complex salt.   The water-soluble nitrate compound (C) is at least one selected from the group consisting of titanium nitrate, zirconium nitrate, magnesium nitrate, calcium nitrate, aluminum nitrate, zinc nitrate, strontium nitrate, manganese nitrate, and copper nitrate. The metal surface treatment liquid according to any one of 2 to 8.   The metal surface treatment liquid according to any one of claims 2 to 9, wherein the water-soluble aluminum compound (D) is at least one selected from the group consisting of aluminum nitrate, aluminum sulfate, and aluminum fluoride.   The metal surface treatment liquid according to any one of claims 2 to 10, wherein the water-soluble zinc compound (E) is at least one selected from the group consisting of zinc nitrate and zinc sulfate.   The fluorine compound (F) is at least one selected from the group consisting of hydrofluoric acid, ammonium fluoride, fluorotitanic acid, fluorotitanium complex, fluorozirconic acid, fluorozirconium complex, aluminum fluoride, and tin fluoride. The metal surface treatment solution according to any one of claims 2 to 11, which is a seed.   The cationic water-soluble resin (G) is at least one selected from the group consisting of an amino group-containing water-soluble oligomer and a water-soluble polymer, and the content of the resin (G) is 0.001 to 1 mmol / The metal surface treatment liquid according to any one of claims 4 to 12, which is L.   6. The silane compound (H) is at least one selected from the group consisting of a silane coupling agent and colloidal silica, and the content of the compound (H) is 0.02 to 20 mmol / L. The metal surface treatment liquid according to any one of ˜13.   The chelating agent (I) is at least one selected from the group consisting of oxalic acid, tartaric acid, citric acid, malic acid, organic phosphonic acid, nitrilotriacetic acid, and ethylenediaminetetraacetic acid, and the chelating agent (I) The metal surface treatment liquid according to any one of claims 6 to 14, wherein the content is 0.001 to 10 mmol / L.   Transport in which the metal to be treated is composed of at least one metal material selected from the group consisting of cold-rolled steel plates, aluminum plates, aluminum alloy plates, zinc plates, zinc alloy plates, galvanized steel plates, and galvannealed steel plates The metal surface treatment liquid according to any one of claims 1 to 15, which is a vehicle for use or a part thereof and contains metal ions eluted from the metal to be treated. A metal is surface-treated using the metal surface treatment solution according to any one of claims 1 to 16, and the amount of adhesion is 0.02 to 2.0 mmol / m ² as tellurium on the metal surface, and Titanium or zirconium or 0.02 to 2.0 mmol / m ² as the total, when converted to a film thickness, forms a chemical film of 2.0 to 200 nm, washed with water, deionized water, without drying, A metal surface treatment method comprising subjecting a metal surface to electrodeposition coating.

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