JP2008202149A - Treatment liquid for metal surface treatment, and surface treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment liquid and a surface treatment method where a surface treatment film having excellent corrosion resistance after coating can be deposited on a metal surface without incorporating components harmful to the environment and without generating sludge made into waste. <P>SOLUTION: Disclosed is a water base surface treatment liquid for surface-treating a metallic material selected from an iron based material, a zinc based material, an aluminum based material and a magnesium based material or simultaneously surface-treating two or more kinds thereamong. The treatment liquid comprises: (1) one or more kinds of compounds selected from a zirconium compound and a titanium compound by 5 to 5,000 ppm in terms of the above metallic element; (2) free fluorine ions by 0.1 to 100 ppm; and (3) one or more kinds of compounds selected from the group consisting of a calcium compound, a magnesium compound and a strontium compound; wherein, the concentration of the above compound is 5 to 50 ppm in the case of a calcium compound in terms of the above metallic element, and is 10 to 5,000 ppm in the case of a magnesium compound or a strontium compound in terms of the above metallic element, further comprises: (4) nitrate of 1,000 by 50,000 ppm; and (5) at least one kind of oxygen acid and/or oxoate selected from HBrO<SB>3</SB>, HNO<SB>2</SB>, H<SB>2</SB>O<SB>2</SB>, H<SB>2</SB>WO<SB>4</SB>, H<SB>2</SB>MoO<SB>4</SB>and their salts, and has (6) a pH of 3 to 6. The treatment liquid may further comprise a polymer compound and a surfactant. A metallic material is brought into contact with the above treatment liquid, so as to form a film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention can be applied to the surface of a metal material of an iron-based material, a zinc-based material, an aluminum-based material, and a magnesium-based material typified by an automobile body or a structure composed of 2 to 4 kinds thereof. Relates to a surface treatment treatment liquid and a surface treatment method capable of precipitating a surface treatment film having excellent corrosion resistance after coating two to four kinds at the same time.

  As a technique for depositing a surface treatment film having excellent corrosion resistance after coating on a metal surface, a zinc phosphate treatment method and a chromate treatment method are generally used. The zinc phosphate treatment method can deposit a film having excellent corrosion resistance on the surface of steel such as cold-rolled steel sheets, galvanized steel sheets and some aluminum alloys. However, when the zinc phosphate treatment is performed, the generation of sludge as a by-product of the reaction is inevitable, and depending on the type of aluminum alloy, the yarn rust resistance after coating cannot be sufficiently ensured. For aluminum alloys, sufficient post-painting performance can be ensured by applying chromate treatment. However, due to recent environmental regulations, chromate treatment containing hexavalent chromium harmful to the treatment liquid is in a direction to be avoided. Therefore, the following invention has been proposed as a surface treatment method that does not contain harmful components in the treatment liquid.

  For example, a compound containing a nitrogen atom having a lone electron pair and a non-chromium coating agent for a metal surface containing the compound and a zirconium compound have been proposed (see Patent Document 1). This method makes it possible to obtain a surface-treated film excellent in corrosion resistance and adhesion after coating without applying hexavalent chromium, which is a harmful component, by applying the composition. However, since the target metal material is limited to aluminum alloy and a surface treatment film is formed by coating and drying, it is difficult to apply to a complicated structure such as an automobile body.

  Then, many methods are proposed as a method of depositing the surface treatment film | membrane which is excellent in the adhesiveness and corrosion resistance after coating by chemical conversion reaction (for example, refer patent document 2, patent document 3, patent document 4, and patent document 5). . However, the metal materials targeted by either method are limited to aluminum alloys that are excellent in corrosion resistance of the materials themselves, and it was impossible to deposit a surface treatment film on the surface of iron-based materials or zinc-based materials. .

Further, a method for depositing a surface treatment film having excellent corrosion resistance and adhesion after coating with a surface treatment composition comprising a metal acetylacetonate and a water-soluble inorganic titanium compound or a water-soluble inorganic zirconium compound has been proposed ( (See Patent Document 6).
By using this method, the metal material applied was expanded to magnesium, magnesium alloy, zinc, and galvanized alloy in addition to aluminum alloy. However, in this method, it is impossible to deposit a surface treatment film on the surface of an iron-based material such as a cold-rolled steel sheet, and the iron-based material cannot be treated simultaneously.

  Further, a metal surface treatment method using a chromium-free coating-type acidic composition, for example, an aqueous solution of a component that can be a film having excellent corrosion resistance is applied to the metal surface, and then the film is fixed by baking and drying without performing a water washing step. A metal surface treatment method has been proposed (see Patent Document 7). Since this method does not involve a chemical reaction in the formation of the film, it is possible to perform a film treatment on metal surfaces such as galvanized steel sheets, cold-rolled steel sheets, and aluminum alloys. However, similarly to the invention disclosed in Patent Document 1, since a film is generated by coating and drying, it is difficult to perform a uniform film treatment on a complicated structure such as an automobile body.

  Therefore, in the prior art, it is a treatment liquid that does not contain environmentally harmful components and does not generate sludge as waste, such as ferrous materials such as cold-rolled steel sheets and zinc-based materials such as galvanized steel sheets, It has been impossible to treat two or four types of aluminum and magnesium materials at the same time and perform surface treatment with excellent corrosion resistance and adhesion.

JP 2000-204485 A JP-A-56-136978 JP-A-8-176841 Japanese Patent Laid-Open No. 9-25436 JP-A-9-31404 JP 2000-199077 A JP-A-5-195244

  The present invention does not contain components harmful to the environment, which is impossible with the prior art, and does not generate waste sludge, and is coated on the surface of iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials. Provided is a treatment liquid for surface treatment that makes it possible to deposit a surface treatment film having excellent corrosion resistance later, and two to four types of iron-based material, zinc-based material, aluminum-based material, and magnesium-based material as in an automobile body. Provided with a surface treatment solution that allows a surface treatment film with excellent corrosion resistance after coating to be deposited on the metal surface of a structure with a combination of seeds at the same composition and under the same conditions. It is an object of the present invention to provide a surface treatment method using a treatment liquid.

As a result of intensive studies on means for solving the above problems, the present inventors have completed a surface treatment solution and a surface treatment method that are not present in the prior art.
That is, the present invention is a water-based surface treatment liquid for surface-treating a metal material selected from iron-based material, zinc-based material, aluminum-based material and magnesium-based material alone or two or more of them simultaneously,
(1) One or more compounds selected from a zirconium compound and a titanium compound are used as the metal element in an amount of 5 to 5000 ppm,
(2) 0.1-100 ppm of free fluorine ions, and (3) one or more compounds selected from the group consisting of calcium compounds, magnesium compounds, and strontium compounds, and the concentration of the compound as the metal element, 5 to 50 ppm for calcium compounds and 10 to 3000 ppm for magnesium compounds or strontium compounds (4) Contains 1000 to 50000 ppm nitrate radicals (5) HBrO ₃ , HNO ₂ , H ₂ O ₂ , H ₂ WO ₄ And H ₂ MoO ₄ and at least one oxygen acid and / or oxyacid salt selected from these salts (6) A metal surface treatment solution characterized by having a pH of 3 to 6 . One or more compounds selected from a zirconium compound and a titanium compound are contained as the metal element in an amount of 5 to 5000 ppm, free fluorine ions are contained in an amount of 0.1 to 100 ppm, and the pH is 2 to 6. This is a treatment liquid for surface treatment.

  These surface treatment liquids may further contain at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound, a nonionic surfactant, an anionic interface. You may contain the at least 1 sort (s) of surfactant chosen from an activator and a cationic surfactant.

  In the present invention, each of metal materials selected from iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials may be brought into contact with the above-mentioned surface treatment solution at the same time or two or more of them simultaneously. This is a metal surface treatment method. In this surface treatment method, at least one selected from the group consisting of cobalt, nickel, tin, copper, titanium, and zirconium, after being brought into contact with the treatment liquid for surface treatment, without being washed with water or with water. It may be contacted with an acidic aqueous solution of a compound containing any of these elements, or may be contacted with a treatment liquid containing at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound.

  In addition, the present invention provides the above-described surface treatment using a metal material selected from iron-based material, zinc-based material, aluminum-based material, and magnesium-based material alone or two or more of them simultaneously and using the metal material as a cathode. It is the metal surface treatment method characterized by carrying out the electrolytic treatment in the process liquid. In this surface treatment method, at least selected from the group consisting of cobalt, nickel, tin, copper, titanium, and zirconium, after the electrolytic treatment of the metal material in the surface treatment solution, without being washed with water or with water. You may make it contact with the acidic aqueous solution of the compound containing 1 type of elements, and you may make it contact with the process liquid containing at least 1 sort (s) of high molecular compound chosen from a water-soluble high molecular compound and a water-dispersible high molecular compound. .

  In addition, the present invention provides a metal material selected from iron-based material, zinc-based material, aluminum-based material, and magnesium-based material that has not been degreased and cleaned, or two or more of them simultaneously. A surface treatment solution containing at least one surfactant selected from nonionic surfactants, anionic surfactants and cationic surfactants, to perform degreasing treatment and film formation treatment on the metal surface. This is a method that can be performed simultaneously.

Further, the present invention provides at least one metal element selected from titanium and zirconium formed on the surface of a metal material selected from iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials by the surface treatment method described above. In the case of a surface of a zinc-based metal material, the amount of the surface-treated film including the surface treatment film is 30 mg / m ² or more in the case of an iron-based metal material surface in terms of the metal element. is a 20 mg / m ² or more, in the case of aluminum-based metal material surface is at 10 mg / m ² or more, a metal material, characterized in that in the case of magnesium-based metal material surface is 10 mg / m ² or more is there.

  According to the treatment liquid for surface treatment of the present invention and the surface treatment method using this treatment liquid, without generating sludge in a treatment bath that does not contain components harmful to the environment, which is impossible with the prior art, A surface-treated film having excellent corrosion resistance after coating can be deposited on a metal surface composed of two or four of iron-based material, zinc-based material, aluminum-based material and magnesium-based material simultaneously or individually. Further, the surface treatment film can be deposited without performing the surface adjustment step of the metal material to be treated. In this case, the treatment step can be shortened and the space can be saved.

The present invention provides a surface-treated film excellent in corrosion resistance after coating by individually or individually treating metal materials selected from iron-based materials, zinc-based materials, aluminum-based materials and magnesium-based materials. It is related to the technique of depositing. Here, the iron-based material refers to a steel plate such as a cold-rolled steel plate and a hot-rolled steel plate, and an iron-based metal such as cast iron and a sintered material. The zinc-based material refers to zinc die-casting or zinc-containing plating. This zinc-containing plating is plated with zinc or an alloy of zinc and another metal (for example, at least one metal such as nickel, iron, aluminum, manganese, chromium, magnesium, cobalt, lead and antimony) and inevitable impurities. The plating method is not limited by, for example, hot dipping, electroplating, and vapor deposition plating.
The aluminum-based material refers to an aluminum alloy plate material such as a 5000-series aluminum alloy or a 6000-series aluminum alloy, an aluminum alloy die-cast represented by ADC-12, or the like. Further, the magnesium-based material refers to a plate material, die-cast, or the like using a magnesium alloy.

  The present invention is applied to a structure including a single metallic material as a constituent member, or a structure including two to four metallic materials as a constituent member. And when applying to the structure which contains 2 to 4 types of said metal materials in a structural member, the surface of 2 to 4 types of metal materials can be surface-treated simultaneously. Here, when the surface treatment of two to four kinds of metal materials is performed simultaneously, the dissimilar metals may not be in contact with each other, and the dissimilar metals are joined and contacted by a joining method such as welding, adhesion, riveting or the like. It does not matter even if it is in the state.

The treatment liquid for surface treatment of the present invention contains 5 to 5000 ppm of one or more compounds selected from a zirconium compound and a titanium compound as the metal element, contains 0.1 to 100 ppm of free fluorine ions, and has a pH of 2 to 2. 6 treatment liquid. Here, examples of the zirconium compound used in the present invention include ZrCl ₄ , ZrOCl ₂ , Zr (SO ₄ ) ₂ , ZrOSO ₄ , Zr (NO ₃ ) ₄ , ZrO (NO ₃ ) ₂ , H ₂ ZrF ₆ , H _2. ZrF ₆ salts, ZrO ₂ , ZrOBr ₂ , ZrF _{4 and the} like can be mentioned. Titanium compounds include TiCl ₄ , Ti (SO ₄ ) ₂ , TiOSO ₄ , Ti (NO ₃ ) ₄ , TiO (NO ₃ ) ₂ , TiO ₂ OC ₂ O ₄ , H ₂ TiF ₆ , and H ₂ TiF ₆ . Examples thereof include salts, TiO ₂ , and TiF ₄ . In the present invention, a zirconium compound is preferably used.

  The concentration of one or more compounds selected from the zirconium compound and titanium compound used in the present invention is preferably 5 to 5000 ppm as the metal element (that is, as zirconium and / or titanium), more preferably 10 to 10 ppm. 3000 ppm. Since the film obtained using the surface treatment solution and the surface treatment method of the present invention is an oxide or hydroxide of zirconium or titanium, the concentration of one or more compounds selected from the zirconium compound or titanium compound is high. If it is less than 5 ppm as zirconium and / or titanium, it is difficult to obtain a sufficient amount of adhesion in a practical treatment time for obtaining corrosion resistance because the concentration of the main component of the film is small. Further, when the concentration is higher than 5000 ppm, a sufficient amount of adhesion can be obtained, but there is no further effect of improving the corrosion resistance, which is only economically disadvantageous.

  A zirconium compound or a titanium compound is relatively soluble in an acidic solution, but is unstable in an alkaline solution and easily precipitates as an oxide or hydroxide of zirconium or titanium. The surface treatment solution of the present invention has a pH of 2 to 6, more preferably 3 to 6. When the metal material to be treated is brought into contact with the treatment liquid for surface treatment of the present invention at this pH, a dissolution reaction of the metal material to be treated occurs. Then, when the metal material to be treated is dissolved, the pH rises at the metal material interface, and zirconium and titanium oxides or hydroxides are deposited on the surface of the metal material as a film.

In the treatment liquid for surface treatment of the present invention, free fluorine ions are present therein. In order to make free fluorine ions exist, a fluorine compound is added to the surface treatment solution. As a source of this free fluorine ion, hydrofluoric acid, H ₂ ZrF ₆ , H ₂ ZrF ₆ salt, H ₂ TiF ₆ , H ₂ TiF ₆ salt, H ₂ SiF ₆ , H ₂ SiF ₆ salt , HBF ₄ , HBF ₄ salt, NaHF ₂ , KHF ₂ , NH ₄ HF ₂ , NaF, KF, and NH ₄ F. Free fluorine ions have the effect of improving the stability of the zirconium compound and the titanium compound in the surface treatment solution. Furthermore, free fluorine ions are dissolved in an acidic solution with respect to any of iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials, which are metal materials to be subjected to the surface treatment of the present invention. Has the effect of promoting Therefore, by adding a fluorine compound and allowing free fluorine ions to be present, it is possible to improve the reactivity of the metal material to be treated while improving the stability of the treatment liquid for surface treatment of the present invention.

  The present applicant previously used a titanium compound, a zirconium compound, and a fluorine-containing compound for a surface treatment composition and a surface treatment solution for treating the surface of a metal containing at least one of iron or zinc. The ratio A / B between the total molar weight A of the metal elements in the surface treatment composition and the surface treatment liquid and the molar weight B when all fluorine atoms in the fluorine-containing compound are converted to HF is a specific range, Proposed to be 0.06 to 0.18 (PCT / JP02 / 05860). According to the present invention, by defining the concentration, pH, and free fluorine ion concentration of the metal element of the titanium compound or zirconium compound, the iron-based material, the zinc-based material, the aluminum can be used even outside the above specific range. A metal material selected from a base material and a magnesium base material can be surface-treated alone or in combination of two or more thereof.

  Iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials have different reactivities. Therefore, in the prior art, it has been impossible to simultaneously treat two or more of the metal materials. In the present invention, the balance between the stability and reactivity of the treatment liquid for surface treatment can be freely changed by adjusting the concentration of free fluorine ions. Therefore, the iron-based material, zinc-based material having different reactivity, Two or more types of aluminum-based and magnesium-based materials can be subjected to surface treatment simultaneously or independently.

  The density | concentration of the free fluorine ion said here shows the fluorine ion concentration measured using a commercially available ion electrode. It is preferable that the density | concentration of the free fluorine ion in the processing liquid for surface treatment of this invention is 0.1-100 ppm, More preferably, it is 2-70 ppm. When the concentration of free fluorine ions is higher than 100 ppm, the dissolution reaction of the metal material to be treated is promoted, but the zirconium compound and the titanium compound in the surface treatment solution are very stable. Even if the pH rises at the material interface, it is difficult to deposit as a film. On the other hand, when the concentration is less than 0.1 ppm, the effect of improving the stability and reactivity of the surface treatment solution is small, and the meaning of containing free fluorine ions is lost.

  The free fluorine ions in the present invention have the effect of keeping the components eluted by dissolution of the metal material to be treated stably in the surface treatment liquid in addition to the action of improving the stability and reactivity of the surface treatment liquid. . In the case of zinc phosphate treatment, which is one of the prior arts, sludge is generated because, for example, iron ions eluted from an iron-based metal material form iron phosphate which is an insoluble salt with phosphoric acid. In the surface treatment liquid of the present invention, phosphate radicals can be contained in the treatment liquid, but sludge may be generated when the concentration of phosphate radicals exceeds 1.0 g / L. In addition, when the amount of the metal material to be treated is remarkably large with respect to the volume of the treatment bath, for example, inorganic acids such as sulfuric acid and hydrochloric acid; acetic acid, oxalic acid, tartaric acid, citric acid, etc. are used to solubilize the eluted components. Organic acids such as oxalic acid, gluconic acid, phthalic acid, etc .; one or more chelating agents capable of chelating elution components may be added.

  The surface treatment solution of the present invention may contain at least one selected from the group consisting of calcium compounds, magnesium compounds and strontium compounds. In the present invention, the concentration of free fluorine ions in an aqueous solution containing a specific concentration of a zirconium compound and a titanium compound is set within a certain range, whereby two to four types of iron-based material, zinc-based material, aluminum-based material, and magnesium-based material are used. It is possible to perform the surface treatment on the seeds simultaneously or individually. Here, the metal element (calcium, magnesium or strontium) contained in the calcium compound, magnesium compound or strontium compound generates a salt of fluorine and fluoride in the aqueous solution, so that the concentration of free fluorine ions in the aqueous solution is constant. It has the effect of trying to keep the value of. Because of this action, even if various types of metal materials to be processed are surface-treated at the same time, a constant free fluorine ion concentration is always maintained regardless of the ratio of use, so the optimum film for each metal material to be processed Amount of adhesion can be obtained.

  Examples of the calcium compound, magnesium compound or strontium compound that can be used in the present invention include oxides, hydroxides, chlorides, sulfates, nitrates and carbonates of these metal elements. In addition to calcium compounds, magnesium compounds, and strontium compounds, any compound that has an action of keeping the free fluorine ion concentration in the fluorine-containing aqueous solution constant can be used in the present invention regardless of whether it is an inorganic substance or an organic substance. it can.

  The concentration of the magnesium compound or strontium compound used in the present invention is preferably 10 to 5000 ppm, more preferably 100 to 3000 ppm as the metal element. In the case of a calcium compound, since the solubility of calcium fluoride is remarkably small, 5-100 ppm as calcium is preferable, More preferably, it is 5-50 ppm. Here, when the concentration of the compound is larger than the upper limit value, the stability of the treatment liquid for surface treatment may be impaired, which may cause trouble in continuous operation. In addition, when the concentration of the compound is smaller than the lower limit, the amount of the coating of the present invention on the iron-based material may be reduced.

  Moreover, 1000 to 50000 ppm, more preferably 1000 to 30000 ppm of nitrate radicals can be added to the surface treatment solution of the present invention. The nitrate radical acts as an oxidant and has an action of promoting the film deposition reaction in the present invention and an action of increasing the solubility of the calcium compound, magnesium compound or strontium compound in the surface treatment solution. Accordingly, even when the concentration of nitrate radical is less than 1000 ppm, a film having excellent corrosion resistance can be deposited. However, when the concentration of the calcium compound, magnesium compound or strontium compound is high, the surface treatment solution is stable. There is a risk that the sex will be impaired. Further, the concentration of nitrate radicals is sufficient at 50,000 ppm, and adding more nitrate radicals is only economically disadvantageous.

The surface treatment solution of the present invention is selected from the group consisting of HClO ₃ , HBrO ₃ , HNO ₃ , HNO ₂ , HMnO ₄ , HVO ₃ , H ₂ O ₂ , H ₂ WO ₄ and H ₂ MoO _4. At least one oxygen acid and / or salts of these oxygen acids can be added. Oxygen acid or a salt thereof acts as an oxidizing agent for the material to be treated, and accelerates the film forming reaction in the present invention. The addition concentration of the above-mentioned oxygen acid or salts of these oxygen acids is not particularly limited, but the effect as an oxidizing agent is sufficiently exhibited with an addition amount of about 10 to 5000 ppm.

  Furthermore, at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound may be added to the surface treatment treatment liquid of the present invention. The metal material surface-treated with the treatment liquid for surface treatment of the present invention has sufficient corrosion resistance. However, when a further function such as lubricity is required, a polymer compound depending on the desired function May be selected and added to modify the physical properties of the film. Examples of the water-soluble polymer compound and the water-dispersible polymer compound include polyvinyl alcohol, poly (meth) acrylic acid, a copolymer of acrylic acid and methacrylic acid, ethylene and (meth) acrylic acid, and (meth). Polymer compounds commonly used for metal surface treatment, such as copolymers with acrylic monomers such as acrylates, copolymers of ethylene and vinyl acetate, polyurethane, amino-modified phenolic resins, polyester resins, and epoxy resins Can be used.

  In order to treat the surface of a metal using the surface treatment liquid of the present invention, it is only necessary to degrease the surface by a conventional method and bring the cleaned metal material into contact with the surface treatment liquid. As a result, a film made of an oxide and / or hydroxide of a metal element selected from zirconium and titanium is deposited on the surface of the metal material, and a surface-treated film layer having good adhesion and corrosion resistance is formed. For this contact treatment, any method such as spray treatment, dipping treatment and pouring treatment can be used, and this contact method does not affect the performance. It is chemically difficult to obtain the metal hydroxide as a pure hydroxide. In general, a form in which the metal oxide has hydrated water is also included in the category of hydroxide. . Therefore, the metal hydroxide eventually becomes an oxide when heated. The structure of the surface treatment film layer in the present invention is a state in which an oxide and a hydroxide are mixed when dried at room temperature or low temperature after the surface treatment, and further when oxidized at a high temperature after surface treatment. It is considered that only the object or the oxide is in a large state.

  There are no particular limitations on the use conditions of the surface treatment solution in the present invention. The reactivity of the surface treatment liquid of the present invention can be freely controlled by changing the concentration of the zirconium compound or the titanium compound and the free fluorine ion concentration in the surface treatment liquid. Therefore, the treatment temperature and treatment time can be changed in any way in combination with the reactivity of the treatment bath.

  In addition, at least one surfactant selected from the group of nonionic surfactants, anionic surfactants and cationic surfactants is added to the above-described surface treatment treatment solution and used for the surface treatment. be able to. When a metal material is surface-treated using the surface treatment liquid, a good film can be formed without degreasing the metal material to be treated in advance and cleaning it. That is, this surface treatment liquid can be used as a degreasing chemical treatment surface treatment agent.

  Further, in order to treat the surface of a metal using the surface treatment solution of the present invention, a method of performing electrolysis in the surface treatment solution using a metal material to be treated as a cathode may be employed. Here, when electrolytic treatment is performed using the metal material to be treated as a cathode, a reduction reaction of hydrogen occurs at the cathode interface and the pH rises. As the pH increases, the stability of the zirconium compound and / or titanium compound at the cathode interface decreases, and the surface-treated film is deposited as an oxide or a hydroxide containing water.

  In addition, after contacting the metal material to be treated with the surface treatment liquid or after electrolytic treatment in the surface treatment liquid, from cobalt, nickel, tin, copper, titanium and zirconium without washing with water. By contacting with an acidic aqueous solution of a compound containing at least one element selected from the group consisting of, or a treatment liquid containing at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound, Furthermore, the effect of the present invention can be enhanced.

  The surface-treated film layer obtained by the present invention is a thin film and exhibits excellent coating performance. However, depending on the surface state of the metal material to be treated, there may be a fine defect in the surface-treated film layer. Therefore, an acidic aqueous solution of a compound containing at least one element selected from the group consisting of cobalt, nickel, tin, copper, titanium and zirconium, or at least one selected from a water-soluble polymer compound and a water-dispersible polymer compound By contacting with a treatment liquid containing the above polymer compound, the fine defects are covered and the corrosion resistance is further enhanced.

  The compound containing at least one element selected from the group consisting of cobalt, nickel, tin, copper, titanium, and zirconium is not particularly limited, but is easily available as an oxide or hydroxide of the metal element. , Fluoride, complex fluoride, chloride, nitrate, oxynitrate, sulfate, oxysulfate, carbonate, oxycarbonate, phosphate, oxyphosphate, oxalate, oxysilicate, organometallic compounds, etc. Can be used. The pH of the acidic aqueous solution containing the metal element is preferably 2 to 6, and acids such as phosphoric acid, nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, and organic acids, sodium hydroxide, hydroxide It can adjust with alkalis, such as potassium, lithium hydroxide, an alkali metal salt, an ammonium salt, and amines.

  Examples of at least one polymer compound selected from the water-soluble polymer compound and the water-dispersible polymer compound include polyvinyl alcohol, poly (meth) acrylic acid, and a copolymer of acrylic acid and methacrylic acid. , Copolymers of ethylene and acrylic monomers such as (meth) acrylic acid and (meth) acrylate, copolymers of ethylene and vinyl acetate, polyurethane, amino-modified phenolic resins, polyester resins, epoxy resins, Tannin, tannic acid and its salt, phytic acid and the like can be used.

  The present invention dramatically increases the corrosion resistance of a metal material by providing a surface treatment film layer made of an oxide and / or hydroxide of a metal element selected from zirconium and / or titanium on the surface of the metal material to be treated. It is possible. Here, the oxide and hydroxide of the metal element have a chemically stable property that is hardly affected by acid or alkali. In an actual metal corrosive environment, a decrease in pH occurs at the anode portion where metal elution occurs, and a pH increase occurs at the cathode portion where the reduction reaction occurs. Therefore, the surface treatment film inferior in acid resistance and alkali resistance dissolves in a corrosive environment and loses its effect. Since the main component of the surface treatment film layer in the present invention is not easily affected by acid or alkali, excellent effects are maintained even in a corrosive environment.

  In addition, the metal element oxides and hydroxides form a network structure through the metal and oxygen, so that a very good barrier film is obtained. Although the corrosion of a metal material differs depending on the environment in which it is used, it is generally an oxygen demand type corrosion in the presence of water and oxygen, and the corrosion speed is accelerated by the presence of components such as chloride. Here, since the surface treatment film layer of the present invention has a barrier effect against water, oxygen and corrosion promoting components, it can exhibit excellent corrosion resistance.

Here, in order to improve the corrosion resistance of iron-based materials such as cold rolled steel sheet, hot rolled steel sheet, cast iron and sintered material using the barrier effect, adhesion of 30 mg / m ² or more in terms of the metal element The amount is necessary, and the amount is preferably 40 mg / m ² or more, more preferably 50 mg / m ² or more. Moreover, in order to improve the corrosion resistance of zinc-based materials such as zinc or galvanized steel sheets and alloyed hot-dip galvanized steel sheets, an amount of adhesion of 20 mg / m ² or more in terms of the metal element is required, preferably 30 mg / m ^2. It is the above adhesion amount. Furthermore, in order to improve the corrosion resistance of aluminum-based materials such as aluminum castings and aluminum alloy plates, an amount of deposit of 10 mg / m ² or more is required in terms of the metal element, and preferably an amount of deposit of 20 mg / m ² or more. . Further, in order to enhance the corrosion resistance of magnesium-based materials such as magnesium alloy plates and magnesium castings, an amount of adhesion of 10 mg / m ² or more is required in terms of the metal element, and preferably an amount of adhesion of 20 mg / m ² or more. . Although there is no restriction | limiting in particular about the upper limit of the adhesion amount, If the adhesion amount exceeds 1 g / m < ² >, it will become easy to generate | occur | produce a crack in a surface treatment film layer, and the operation | work which obtains a uniform film | membrane will become difficult. Therefore, iron-based material, zinc-based material, and aluminum-based materials in both, the upper limit of the coating weight, preferably from 1 g / m ² is 800 mg / m ^2.

  Examples are given below together with comparative examples to specifically describe the effects of the surface treatment liquid and the surface treatment method of the present invention. In addition, the to-be-processed material used in the Example, a degreasing agent, and a coating material are arbitrarily selected from commercially available materials, and limit the actual use of the surface treatment liquid and the surface treatment method of the present invention. Not what you want.

[Test plate]
Cold rolled steel plates, hot dip galvanized steel plates, aluminum alloy plates and magnesium alloy plates were used for the test plates of the examples and comparative examples. The abbreviations and breakdown of this test plate are shown below.
For evaluation of the appearance after the surface treatment, a test plate in which three kinds of metal materials of SPC, GA and Al were joined by spot welding was used. For the evaluation of the adhesion amount of the surface treatment film layer, each test plate of SPC, GA, Al, and Mg, and a test plate in which three kinds of metal materials of SPC, GA, and Al are joined by spot welding, Was used. For the evaluation of coating performance, a series of tests from surface treatment, coating, and coating performance evaluation were carried out using test plates in which three kinds of metal materials of SPC, GA and Al were joined by spot welding. FIG. 1 is a plan view of a test plate spot welded with three kinds of metal materials of SPC, GA, and Al, and FIG. 2 is a front view thereof. Reference numeral 1 denotes a spot weld.
・ SPC (Cold rolled steel sheet: JIS-G-3141)
GA (double-side alloyed hot-dip galvanized steel sheet: plating weight 45 g / m ² )
・ Al (aluminum alloy plate: 6000 series aluminum alloy)
・ Mg (magnesium alloy plate: JIS-H-4201)

[Processing process]
The processing steps of the examples and comparative examples are as follows.
Examples 1-4, Reference Example 7 and Comparative Examples 1-4: Alkaline degreasing → Washing → Film conversion treatment → Washing → Pure water washing → Drying Reference example 5: Alkaline degreasing → Water washing → Electrochemical conversion treatment → Washing → Pure water washing → Drying Example 6: Film chemical conversion treatment (degreasing chemical combination) → water washing → pure water washing → drying Example 8: alkali degreasing → water washing → film chemical conversion treatment → water washing → post treatment → pure water washing → drying Example 9: film chemical conversion treatment (degreasing) Chemical conversion) → Washing → Post-treatment → Pure water washing → Drying Comparative Example 5: Alkaline degreasing → Washing → Surface preparation → Zinc phosphate treatment → Washing → Pure water washing → Drying Cleaner L4460 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.) was diluted to 2% with tap water and sprayed onto a plate to be treated at 40 ° C. for 120 seconds. The washing with water and the washing with pure water after the film treatment were sprayed on the plate to be treated for 30 seconds at room temperature in both the examples and the comparative examples.

Example 1
An aqueous solution having a zirconium concentration of 200 ppm was prepared using a zirconium oxynitrate reagent and nitric acid. After heating this aqueous solution to 45 ° C, the pH is adjusted to 3.0 using a sodium hydroxide reagent and hydrofluoric acid, and a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) The surface treatment solution was prepared by adjusting the free fluorine ion concentration measured at 1 to 1 ppm. The total fluorine concentration in the surface treatment solution after adjusting the free fluorine ion concentration was 50 ppm.
The test plate that had been degreased and washed with water was immersed in the surface treatment solution for 120 seconds for surface treatment.

Example 2
Using a zirconium oxynitrate reagent, a magnesium nitrate reagent, and a strontium nitrate reagent, an aqueous solution having a zirconium concentration of 100 ppm, a magnesium concentration of 5000 ppm, a strontium concentration of 2000 ppm, and a nitrate radical of 28470 ppm was prepared. After heating this aqueous solution to 50 ° C, the pH is adjusted to 4.0 using an aqueous ammonia reagent and hydrofluoric acid, and measurement is performed with a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.). The free fluorine ion concentration to be adjusted to 80 ppm was used as a surface treatment solution. The total fluorine concentration in the treatment liquid for surface treatment after adjusting the free fluorine ion concentration was 2000 ppm.
The test plate that had been degreased and washed with water was immersed in the surface treatment solution for 60 seconds to perform surface treatment.

Example 3
Using an aqueous hexafluorozirconate (IV) solution, an aqueous titanium (IV) sulfate solution, a calcium sulfate reagent, and nitric acid, an aqueous solution having a zirconium concentration of 1000 ppm, a titanium concentration of 2000 ppm, a calcium concentration of 5 ppm, and a nitrate radical of 1000 ppm was prepared. After heating this aqueous solution to 40 ° C., the pH is adjusted to 5.0 using a potassium hydroxide reagent and hydrofluoric acid, and a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) The surface treatment solution was prepared by adjusting the free fluorine ion concentration measured in step 1 to 25 ppm. The total fluorine concentration in the surface treatment solution after adjusting the free fluorine ion concentration was 2250 ppm.
The test plate that had been degreased and washed with water was immersed in the surface treatment solution for 90 seconds for surface treatment.

Example 4
Using an aqueous hexafluorotitanate (IV) solution, a strontium nitrate reagent and a sodium nitrite reagent, an aqueous solution having a titanium concentration of 5000 ppm, a strontium concentration of 5000 ppm, a nitrate radical of 7080 ppm, and a nitrite radical of 40 ppm was prepared. After heating this aqueous solution to 35 ° C., the pH is adjusted to 4.0 using a triethanolamine reagent and hydrofluoric acid, and a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) The surface treatment solution was prepared by adjusting the free fluorine ion concentration measured in step 1 to 10 ppm. The total fluorine concentration in the surface treatment solution after adjusting the free fluorine ion concentration was 11900 ppm.
The surface treatment was carried out by spraying the above-mentioned surface treatment solution on a test plate that had been washed with water after degreasing for 120 seconds.

Reference Example 5
Using zirconium oxynitrate reagent, hexafluorotitanate (IV) aqueous solution, magnesium nitrate reagent, nitric acid and sodium chlorate reagent, zirconium concentration is 5 ppm, titanium concentration is 5 ppm, magnesium concentration is 100 ppm, nitrate radical is 30520 ppm, chlorate radical An aqueous solution with 100 ppm was prepared. After heating this aqueous solution to 30 ° C, the pH is adjusted to 6.0 using ammonia water reagent and hydrofluoric acid, and measured with a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.). The surface treatment solution was adjusted to a free fluorine ion concentration of 0.5 ppm. The total fluorine concentration in the treatment liquid for surface treatment after adjusting the free fluorine ion concentration was 12 ppm.
Using a test plate that had been degreased and washed with water as a cathode, and using a carbon electrode as the anode, surface treatment was performed by electrolysis for 5 seconds in the above-described surface treatment solution under an electrolytic condition of 5 A / dm ² .

Example 6
Using a zirconium oxynitrate reagent, a magnesium oxide reagent, nitric acid, and a hydrogen peroxide solution, an aqueous solution having a zirconium concentration of 150 ppm, a magnesium concentration of 10 ppm, a nitrate radical of 5200 ppm, and hydrogen peroxide of 10 ppm was prepared.
After heating this aqueous solution to 50 ° C., the pH is adjusted to 5.0 using an aqueous ammonia reagent and hydrofluoric acid, and with a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.). The concentration of free fluorine ions to be measured was adjusted to 50 ppm, and 2 g / L of polyoxyethylene nonyl phenyl ether (number of moles of ethylene oxide added: 12 mol), which is a nonionic surfactant, was added to the surface treatment treatment liquid. did. The total fluorine concentration in the treatment liquid for surface treatment after adjusting the free fluorine ion concentration was 170 ppm.
The surface treatment was performed simultaneously with the degreasing by spraying the above-mentioned surface treatment treatment liquid on the test plate as it was without being degreased and sprayed for 90 seconds.

Reference Example 7
Using titanium (IV) sulfate aqueous solution, calcium nitrate reagent, magnesium nitrate reagent and potassium permanganate reagent, titanium concentration is 100 ppm, calcium concentration is 50 ppm, magnesium concentration is 5000 ppm, nitrate radical is 25660 ppm, and permanganate is 10 ppm. An aqueous solution was prepared. Further, a water-soluble acrylic polymer compound (Jurimer AC-10L: manufactured by Nippon Pure Chemical Co., Ltd.) was added to this aqueous solution so that the solid content concentration would be 1% and heated to 50 ° C., and then a sodium hydroxide reagent. PH adjusted to 3.0 with HF and hydrofluoric acid, and free fluorine ion concentration measured with a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) is adjusted to 95 ppm to treat the surface treatment It was. The total fluorine concentration in the treatment liquid for surface treatment after adjusting the free fluorine ion concentration was 2000 ppm.
The test plate that had been washed with water after the degreasing treatment was immersed in the surface treatment solution for 60 seconds for surface treatment.

Example 8
An aqueous solution in which a water-soluble acrylic polymer compound (Julimer AC-10L: manufactured by Nippon Pure Chemical Co., Ltd.) was 1% in terms of solid content and a phosphate reagent was 2 g / L as a phosphate group was prepared. This aqueous solution was heated to 40 ° C., and then adjusted to pH 4.5 with an aqueous ammonia reagent to prepare a post-treatment liquid. The test plate that had been subjected to film formation and water washing in the surface treatment of Example 5 was immersed in the post-treatment liquid for 30 seconds to perform post-treatment.

Example 9
Using an aqueous hexafluorozirconic acid (IV) solution and a cobalt nitrate reagent, an aqueous solution having a zirconium concentration of 50 ppm and a cobalt concentration of 50 ppm was prepared, and the aqueous solution was further heated to 40 ° C. Was adjusted to 5.0 to prepare a post-treatment liquid. The test plate that had been subjected to film formation and water washing in the surface treatment of Example 6 was immersed in the above-described post-treatment liquid for 30 seconds for post-treatment.

Comparative Example 1
Using a zirconium oxynitrate reagent, a magnesium nitrate reagent, and nitric acid, an aqueous solution having a zirconium concentration of 500 ppm, a magnesium concentration of 1000 ppm, and a nitrate radical of 6780 ppm was prepared. This aqueous solution was heated to 45 ° C., and then adjusted to pH 4.0 with a sodium hydroxide reagent to obtain a surface treatment solution. The free fluorine ion concentration in the surface treatment solution was measured with a commercially available fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) and found to be 0 ppm.
The test plate that had been degreased and washed with water was immersed in the surface treatment solution for 120 seconds for surface treatment.

Comparative Example 2
An aqueous solution having a titanium concentration of 2000 ppm was prepared using an aqueous solution of titanium (IV) sulfate. After the aqueous solution is heated to 50 ° C., the pH is adjusted to 3.5 with an aqueous ammonia reagent and hydrofluoric acid, and measured by a fluorine ion meter (IM-55G; manufactured by Toa Denpa Kogyo Co., Ltd.) The surface treatment liquid was prepared by adjusting the fluorine ion concentration to 400 ppm.
The test plate that had been degreased and washed with water was immersed in the surface treatment solution for 90 seconds for surface treatment.

Comparative Example 3
Alchrome 713 (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.), which is a commercially available chromic chromate treatment agent, was diluted to 3.6% with tap water, and the total acidity and free acidity were adjusted to the center of the catalog value.
The test plate that had been degreased and washed with water was immersed in the chromate treatment solution heated to 35 ° C. for 60 seconds for chromate treatment.

Comparative Example 4
Palcoat 3756 (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.), a commercially available non-chromate treatment agent, was diluted to 2% with tap water, and the total acidity and free acidity were adjusted to the center of the catalog value. The test plate that had been degreased and washed with water was immersed in the non-chromate treatment solution heated to 40 ° C. for 60 seconds to perform non-chromate treatment.

Comparative Example 5
A test plate that has been degreased and washed with water is sprayed with a solution prepared by diluting Preparen ZN (registered trademark: manufactured by Nippon Parkerizing Co., Ltd.) 0.1% with tap water at room temperature for 30 seconds. After that, Palbond L3020 (registered trademark: manufactured by Nihon Parkerizing Co., Ltd.) was diluted to 4.8% with tap water, and after adding 200 ppm of sodium hydrogen fluoride reagent as fluorine, the total acidity and free acidity were cataloged. A zinc phosphate coating was deposited by dipping in a 42 ° C. zinc phosphate conversion solution adjusted to the center of the value.

[Evaluation of surface treatment film]
The appearance of the test plates after the surface treatment of the examples and comparative examples was visually evaluated. The results are shown in Table 1. Moreover, the adhesion amount of the surface treatment film layer was measured with a fluorescent X-ray analyzer (system 3270; manufactured by Rigaku Denki Kogyo Co., Ltd.). The results are shown in Tables 2 and 3. In addition, the adhesion amount of the surface treatment film layer was measured when each metal material was treated individually without joining (no joining) and when treated by spot welding (joined).

  Table 1 shows the appearance evaluation results of the surface treatment films obtained in Examples and Comparative Examples. In Examples and Reference Examples, uniform films could be obtained for all metal material types of all test plates. Furthermore, it was observed that the surface treatment film was deposited on the spot welds of the test plates used in Examples and Reference Examples. On the other hand, in the comparative example, a uniform film could not be deposited on all the test plates. In particular, in Comparative Examples 3, 4, and 5, no film was deposited on the spot welds. Moreover, although the comparative example 5 is a zinc phosphate processing liquid used when processing a cold-rolled steel plate, a galvanized steel plate, and an aluminum alloy simultaneously, each test piece was joined by welding like this test. Under the conditions, a portion where a metal material base called Suke was exposed appeared on the cold-rolled steel sheet.

  Tables 2 and 3 show the measurement results of the adhesion amount of the surface treatment film obtained in Examples, Reference Examples and Comparative Examples. In Examples and Reference Examples, target adhesion amounts could be obtained for all metal material types of all test plates. Moreover, the adhesion amount of the surface treatment film layer in Examples and Reference Examples was constant regardless of the presence or absence of bonding of the test plates. On the other hand, in the comparative example, a uniform film could not be deposited on all the test plates, as is apparent from the film appearance evaluation results.

[Evaluation of coating performance]
(Preparation of paint performance evaluation board)
In order to evaluate the coating performance of the surface treated plates of Examples, Reference Examples and Comparative Examples,
The coating was performed in the process of cationic electrodeposition coating → pure water washing → baking → intermediate coating → baking → top coating → baking. Cationic electrodeposition coating, intermediate coating, and top coating are as follows.
Cationic electrodeposition coating: Epoxy-based cationic electrodeposition coating (Electron 9400: manufactured by Kansai Paint Co., Ltd.), voltage 200 V, film thickness 20 μm, 175 ° C., 20 minutes baking intermediate coating: aminoalkyd coating (Amirac TP-37 Gray: Kansai Paint Co., Ltd.), spray coating, film thickness 35 μm, 140 ° C. for 20 minutes baking top coating: aminoalkyd paint (Amirac TM-13 white: manufactured by Kansai Paint Co., Ltd.), spray coating, film thickness 35 μm, 140 Baking for 20 minutes

(Painting performance evaluation)
The coating performance of Examples and Comparative Examples was evaluated. The results are shown in Tables 4 and 5. Evaluation items and abbreviations are shown below. The coating film at the time of completion of electrodeposition coating is referred to as an electrodeposition coating film, and the coating film at the time of completion of top coating is referred to as a 3 coats coating film.
<1> SST: Salt spray test (electrodeposition coating)
<2> SDT: salt warm water test (electrodeposition coating)
<3> 1st ADH: Primary adhesion (3coats coating film)
<4> 2nd ADH: Water resistant secondary adhesion (3coats coating)

SST: 5% salt water was sprayed for 840 hours (according to JIS-Z-2371) onto an electrodeposition coated plate with a crosscut cut with a sharp cutter. After spraying, the maximum swollen width on both sides from the crosscut part was measured.
SDT: The electrodeposition coated plate was immersed in a 5 wt% NaCl aqueous solution heated to 50 ° C. for 840 hours. After the immersion, the entire surface of the test piece washed with tap water and dried at room temperature was peeled off with a gum tape, and the peeled area of the coating film on each metal material was visually determined.

1st ADH: 100 coats of 2 mm intervals were cut with a sharp cutter on the 3 coats coating. The cellophane tape was peeled off from the grid area, and the number of peeled grids was counted.
The 2nd ADH: 3coats coating plate was immersed in deionized water at 40 ° C. for 240 hours. After dipping, 100 grids at intervals of 2 mm were cut with a sharp cutter. The cellophane tape was peeled off from the grid area, and the number of peeled grids was counted.

  Table 4 shows the coating performance evaluation results of the electrodeposition coating film. The examples and reference examples showed good corrosion resistance for all the test plates. On the other hand, in Comparative Example 1, since the surface treatment liquid did not contain any free fluorine ions, the surface treatment film did not sufficiently precipitate and the corrosion resistance was poor. Moreover, in the comparative example 2, since the free fluorine ion density | concentration in the processing liquid for surface treatment was high, it was a result in particular that the coating amount on SPC was small and it was inferior to corrosion resistance. Although Reference Example 5 and Example 6 showed coating performance superior to that of the comparative example, the results were slightly inferior in corrosion resistance after electrodeposition coating as compared with other examples. However, as shown in Examples 8 and 9, the corrosion resistance was further improved by the post-treatment.

  Since Comparative Example 3 is a chromate treatment agent for aluminum alloys and Comparative Example 4 is a non-chromate treatment agent for aluminum alloys, the corrosion resistance of Al was excellent, but the corrosion resistance of other test plates is clearly in the examples. It was inferior. Comparative Example 5 is a zinc phosphate treatment generally used as a cationic electrodeposition coating base. However, in Comparative Example 5 as well, the test pieces were inferior to the Examples in the conditions in which the test pieces were joined by welding as in this test.

  Table 5 shows the adhesion evaluation results of the 3coats plate. The Examples and Reference Examples showed good adhesion to all the test plates. As for 1st ADH, good results were obtained in the comparative examples. However, in 2nd ADH, there was no level showing good adhesion to all the test plates as well as the corrosion resistance of the electrodeposition coating film. In Comparative Example 5, sludge, which is a by-product during the zinc phosphate treatment, was generated in the treatment bath after the surface treatment. However, in Examples and Reference Examples, no sludge was observed at any level.

  From the above results, by using the treatment liquid for surface treatment and the surface treatment method according to the present invention, SPC, GA and Al are simultaneously treated without changing the treatment bath and treatment conditions, and the surface has excellent adhesion and corrosion resistance. It is clear that a treatment film can be deposited. Furthermore, by using the present invention, it becomes possible to deposit a surface treatment film having excellent corrosion resistance on the welded portion. In addition, since the surface treatment method of the present invention only needs to contact the metal material to be treated and the treatment liquid for surface treatment, the surface treatment film is deposited even on the portion where the stirring effect cannot be expected, such as inside the bag structure. It is possible to improve the corrosion resistance.

Plan view of the test plate Front view of the test plate

Explanation of symbols

1 Spot weld, SPC cold-rolled steel sheet, GA hot-dip galvanized steel sheet, Al aluminum alloy sheet

Claims (11)

A water-based surface treatment liquid for surface-treating metal materials selected from iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials individually or in combination of two or more thereof,
(1) One or more compounds selected from a zirconium compound and a titanium compound are used as the metal element in an amount of 5 to 5000 ppm,
(2) 0.1-100 ppm of free fluorine ions,
(3) One or more compounds selected from the group consisting of a calcium compound, a magnesium compound and a strontium compound, and the concentration of the compound is 5 to 50 ppm in the case of a calcium compound as the metal element, a magnesium compound or a strontium compound (4) containing 1000 to 50000 ppm of nitrate radical (5) selected from HBrO ₃ , HNO ₂ , H ₂ O ₂ , H ₂ WO ₄ and H ₂ MoO ₄ and their salts (6) A metal surface treatment liquid characterized by having a pH of 3 to 6 and containing at least one oxygen acid and / or oxyacid salt.   The metal surface treatment solution according to claim 1, further comprising at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound.   The metal surface treatment solution according to claim 1 or 2, further comprising at least one surfactant selected from nonionic surfactants, anionic surfactants, and cationic surfactants.   The treatment for surface treatment according to any one of claims 1 to 3, wherein each of metal materials selected from iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials is used alone or in combination of two or more thereof. A metal surface treatment method comprising contacting with a liquid.   After contacting the metal material with the treatment liquid for surface treatment, the acid of the compound containing at least one element selected from the group consisting of cobalt, nickel, tin, copper, titanium and zirconium, with or without washing with water The metal surface treatment method according to claim 4, wherein the metal surface treatment method comprises contacting with an aqueous solution.   A treatment liquid containing at least one polymer compound selected from a water-soluble polymer compound and a water-dispersible polymer compound, with or without being washed with water after contacting the metal material with the treatment liquid for surface treatment; The metal surface treatment method according to claim 4, wherein contact is made.   The surface according to claim 3, wherein each of the metal materials selected from iron-based materials, zinc-based materials, aluminum-based materials, and magnesium-based materials that has not been degreased and cleaned is used alone or in combination of two or more thereof. A metal surface treatment method comprising contacting with a treatment liquid for treatment. A surface treatment film comprising at least one metal element selected from titanium and zirconium formed by the surface treatment method according to claim 4 on the surface of an iron-based metal material, and the surface treatment film The metal material is characterized in that the amount of adhering is 30 mg / m ² or more in terms of the metal element. A surface-treated film comprising at least one metal element selected from titanium or zirconium formed by the surface treatment method according to any one of claims 4 to 7 on the surface of a zinc-based metal material, and the surface-treated film The metal material is characterized in that the amount of adhering is 20 mg / m ² or more in terms of the metal element. A surface treatment film layer containing at least one metal element selected from titanium or zirconium formed by the surface treatment method according to any one of claims 4 to 7 on the surface of an aluminum-based metal material, and the surface treatment A metal material, wherein the amount of coating is 10 mg / m ² or more in terms of the metal element. A surface treatment film layer containing at least one metal element selected from titanium or zirconium formed by the surface treatment method according to any one of claims 4 to 7 on the surface of the magnesium-based metal material, and the surface treatment A metal material, wherein the amount of coating is 10 mg / m ² or more in terms of the metal element.

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