JP2017048447A - Metal surface treatment agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal surface treatment agent capable of imparting excellent corrosion resistivity to a metallic material having various properties of a metallic surface and a metallic structure including a processing part or the like such as an edge part or a weld zone, and not containing a material harmful to an environment.SOLUTION: A metal surface treatment agent having pH of 2-7 comprises at least one kind of metal compound (A) selected from a group comprising Zr, Ti, Hf and Bi as a metal element, and a polyhydric phenol compound (B) having a specific structure.SELECTED DRAWING: None

Description

  The present invention relates to a novel metal surface treatment agent for imparting excellent corrosion resistance to the surfaces of various metal materials and metal structures.

  Many industrial products made of metallic materials are generally painted to prevent corrosion. There are various coating methods such as powder coating, solvent coating, and electrodeposition coating, but there are many cases where sufficient corrosion resistance cannot be obtained just by directly coating metal materials. Substrate treatment such as chemical conversion treatment is performed.

  The most common surface treatment is phosphate treatment. Phosphate treatment has already been used for nearly 100 years, and various improved inventions have been proposed during that time, and it is a treatment agent still used in various industrial fields. On the other hand, insoluble iron phosphate, commonly called sludge, is generated as a by-product of the film deposition reaction. This sludge is precipitated in the system and then discharged out of the system and discarded as industrial waste. Reduction of industrial waste has become a major issue from the viewpoint of conservation, and a treatment agent that does not generate waste is strongly desired.

  Next, as a typical chemical conversion, there is a chromate treatment. The history of practical application of chromate chromate conversion treatment is also old, and it is still widely used for surface treatment of aircraft materials, building materials, automobile parts and so on. Since this chromate chemical conversion treatment agent contains chromic acid composed of hexavalent chromium as a main component, a film partially containing hexavalent chromium is formed on the surface of the metal material. Although the chromate film has excellent corrosion resistance and paint adhesion, it contains harmful hexavalent chromium. Therefore, a chemical conversion treatment agent containing no hexavalent chromium is strongly desired from the environmental viewpoint.

  In recent years, a chemical conversion treatment agent based on zirconium has been proposed (Patent Document 1). Regarding the advantages of the chemical conversion treatment agent based on zirconium, the first advantage is that a film can be formed with a small amount of etching (dissolution of the metal to be treated), and the amount of dissolution of the metal to be treated is small. There is a point that there is almost no sludge generation which was a problem of acid treatment. The second advantage is that it is a chemical conversion treatment agent that does not contain harmful metals such as hexavalent chromium and is environmentally friendly.

JP 2007-262577 A

In the automobile industry, the use of metal materials such as high-tensile steel plates (high-tensile materials) and hot stamp materials is increasing for the purpose of reducing the weight of vehicle bodies. However, these metal materials tend to have poor chemical conversion properties, such as corrosion resistance may be inferior. This is because, for high-strength steel sheets, elements such as Si and Mn added to obtain excellent mechanical properties such as high bending and elongation are concentrated on the metal surface of the high-strength steel sheets. It is conceivable that the stamp material is exposed to a high temperature atmosphere in the manufacturing process, and a thick oxide film is formed on the metal surface, and the properties of the metal surface in these metal materials are not uniform surfaces. hard. Therefore, when these metal materials are subjected to a chemical conversion treatment with a chemical conversion treatment agent, it may be difficult to form a uniform chemical conversion film because of being affected by the state of the metal surface.
On the other hand, in a metal structure (such as an automobile body), there are processed parts such as a welded part subjected to welding in addition to a burr part and an edge part generated in the cutting process of the metal material. Since this processed part also has a non-uniform surface compared to the metal surface of a general metal material, when the processed part is subjected to chemical conversion treatment with a chemical conversion agent, it is affected by the properties of the metal surface. It may be difficult to form a chemical conversion film.
Therefore, a chemical film is uniformly formed on a metal structure including various metal surface properties and processed parts such as edges and welds, and a chemical film with good film performance such as corrosion resistance is formed. Treatment agents are desired.
However, when the inventors evaluated the chemical conversion treatment agent described in Patent Document 1, it has become clear that the film performance on metal materials having various metal surface properties may be insufficient. It was.
Therefore, the present invention can give excellent corrosion resistance to metal materials having various metal surface properties and metal structures including processed parts such as edges and welds, and is harmful to the environment. An object of the present invention is to provide a metal surface treatment agent that does not contain any substances. Further, after a metal material whose metal surface has been cleaned in advance is brought into contact with a metal surface treatment agent, a film is formed on the surface of the metal material by at least one process selected from a chemical conversion reaction process and an electrolytic chemical conversion reaction process. It is another object of the present invention to provide a metal surface treatment method.

  As a result of intensive studies on means for solving the above-mentioned problems, the present inventors have completed a metal surface treatment agent that does not exist in the prior art. That is, the present invention is as follows.

［但し、式（１）のＸ_１〜Ｘ_３は、それぞれ独立に、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基及びアミノ基から選ばれる基であり、Ｚは、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基、アミノ基及び式（２）で表される基から選ばれる基である。］

［式（２）のＸ_４〜Ｘ_６は、それぞれ独立に、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基及びアミノ基から選ばれる基であり、Ｒ１及びＲ２は、それぞれ独立に、水素原子又はメチル基である。］ The present invention (1) adds at least one metal compound (A) selected from the group consisting of Zr, Ti, Hf and Bi as a metal element and a polyhydric phenol compound (B) represented by the formula (1). The metal surface treatment agent having a pH of 2 to 7.

[However, X _{1 to} X ₃ in the formula (1) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group. , Z is a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, an amino group and a group represented by the formula (2). ]

[X _{4 to} X ₆ in the formula (2) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group; And R2 are each independently a hydrogen atom or a methyl group. ]

  This invention (2) is a metal surface treating agent of the said invention (1) which adds 10-5000 mg / L of the said metal compound (A) as the total density | concentration of the said metal element.

  This invention (3) is a metal surface treating agent of the said invention (1) or (2) which adds the said polyhydric phenol compound (B) as a density | concentration 10-10000 mg / L.

  In the present invention (4), the metal material to be treated whose surface has been cleaned in advance is brought into contact with any one of the metal surface treatment agents of the inventions (1) to (3), and then a chemical conversion reaction step and an electrolytic chemical conversion are performed. It is a metal surface treatment method for forming a film on the surface of the metal material to be treated by at least one step selected from reaction steps.

  By using the metal surface treatment agent of the present invention, it is possible to impart excellent corrosion resistance to metal materials having various metal surface properties and metal structures including processed parts such as edges and welds. it can. Furthermore, according to the method of the present invention, almost no by-product harmful to the environment such as sludge is generated, and since no chromium compound is used, the influence on the environment can be reduced.

  One embodiment of the present invention will be described. However, the technical scope of the present invention is not limited to this form. In the present invention, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

≪Metal surface treatment agent≫
An example of the metal surface treating agent according to the present invention must contain at least one metal compound (A) selected from the group consisting of Zr, Ti, Hf and Bi, and a polyhydric phenol compound (B). Each component will be described below.

<Metal compound (A)>
When the metal element of the metal compound (A) is Zr, the metal compound (A) includes, for example, zirconium nitrate, zirconium oxynitrate, zirconium sulfate, zirconium oxysulfate, zirconium acetate, zirconium lactate, fluorozirconic acid, and a fluorozirconium complex salt. Can be mentioned.

  When the metal element of the metal compound (A) is Ti, for example, titanium sulfate, titanium oxysulfate, titanium nitrate, titanium oxynitrate, fluorotitanic acid, and a fluorotitanium complex salt can be used as the metal compound (A).

  When the metal element of the metal compound (A) is Hf, as the metal compound (A), for example, hafnium nitrate, hafnium oxide, hafnium silicate, hafnium chloride, fluorohafnium, a fluorohafnium complex, or the like can be used.

  When the metal element of the metal compound (A) is Bi (trivalent bismuth), the metal compound (A) is bismuth nitrate (III), bismuth phosphate (III), bismuth sulfate (III), bismuth chloride (III) Bismuth (III) fluoride, bismuth bromide (III), bismuth iodide (III), bismuth acetate (III), bismuth formate (III), bismuth citrate (III) complex, bismuth lactate (III) complex, Shu Bismuth (III) acid complex, Bismuth (III) malate, Bismuth (III) tartrate, Bismuth (III) ascorbate, EDTA bismuth (III) complex, NTA bismuth (III) complex, HEDTA bismuth (III) complex , Bismuth tris (methanesulfonic acid) bismuth (III), bismuth benzene sulfonic acid, bismuth tris (D-gluconic acid), bismuth heptogluconic acid (III), etc. Rukoto can.

  The metal compound (A) includes a soluble compound and a hardly soluble compound. When the metal compound (A) is soluble, it can be used after being dissolved in pure water or industrial water. In addition, when the metal compound (A) is hardly soluble, it can be obtained by using an inorganic acid such as nitric acid, sulfuric acid or hydrochloric acid, or an organic acid (chelating agent) such as aminocarboxylic acid, hydroxycarboxylic acid, organic sulfonic acid or organic phosphonic acid. It can be dissolved and used.

  In the metal surface treating agent of the present invention, the metal compound (A) may be used alone, or two or more metal compounds (A) may be used in combination. The concentration of the metal element derived from the metal compound (A) blended in the metal surface treatment agent is not particularly limited as the total concentration of the metal elements, but is preferably 10 to 5,000 mg / L. If it is 10 mg / L or more, the corrosion resistance becomes better, but if it exceeds 5,000 mg / L, no further improvement in corrosion resistance is recognized, resulting in an increase in cost. More preferably, it is 25-5,000 mg / L.

［但し、式（１）のＸ_１〜Ｘ_３は、それぞれ独立に、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基及びアミノ基から選ばれる基であり、Ｚは、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基、アミノ基及び式（２）で表される基から選ばれる基である。］

［式（２）のＸ_４〜Ｘ_６は、それぞれ独立に、水素原子又はメチル基、エチル基、水酸基、スルホン基、ニトロ基、カルボキシル基、メトキシ基及びアミノ基から選ばれる基であり、Ｒ１及びＲ２は、それぞれ独立に、水素原子又はメチル基である。］ <Polyhydric phenol compound (B)>
In the present invention, the polyhydric phenol compound (B) is a compound represented by the formula (1).

[However, X _{1 to} X ₃ in the formula (1) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group. , Z is a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, an amino group and a group represented by the formula (2). ]

[X _{4 to} X ₆ in the formula (2) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group; And R2 are each independently a hydrogen atom or a methyl group. ]

  Specific examples of the polyhydric phenol compound (B) include catechol (1,2-benzenediol), 3-methylcatechol, 4-methylcatechol, 3-ethylcatechol, 4-ethylcatechol, 3-nitrocatechol, 4 -Nitrocatechol, catechol-3,5-disulfonic acid, 2,3-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3-aminocatechol, 4-aminocatechol, 3-methoxycatechol, 4-sulfocatechol, 3, , 5-dimethylcatechol, 3,4-dimethylcatechol, 4,5-dimethylcatechol, 3,6-dimethylcatechol, 3,4,6-trimethylcatechol, 3,4,5-trimethylcatechol, 3,5-dinitro Catechol, 3,6-dinitrocatechol, 3,5-diaminocatechol, 4- Til-5-ethylcatechol, 3-methyl-5-nitrocatechol, 3-methyl-4-nitrocatechol, 4-methyl-5-nitrocatechol, 3,5,6-trimethyl-4-methoxycatechol, 3,4 -Dimethoxycatechol, 4,5-dimethoxycatechol, 3,6-dimethoxycatechol, resorcinol (1,3-benzenediol), 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, 2-ethylresorcinol, 4- Ethylresorcinol, 5-ethylresorcinol, 2-nitroresorcinol, 5-nitroresorcinol, 2-aminoresorcinol, 4-aminoresorcinol, 5-aminoresorcinol, 2-methoxyresorcinol, 4-methoxyresorcinol, 5-methoxy Resorcinol, 2,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 4,5-dimethylresorcinol, 2,4-dimethylresorcinol, 2,5-dimethylresorcinol, 5-ethyl -4-methylresorcinol, 4-ethyl-2-methylresorcinol, 5-methoxy-4-methylresorcinol, 2-methoxy-5-methylresorcinol, 2-nitro-5-methylresorcinol, 4-nitro-5-methylresorcinol 2,4,5-trimethylresorcinol, 2,4,6-trimethylresorcinol, tetramethylresorcinol, 2,5-dimethoxyresorcinol, hydroquinone (1,4-benzenediol), methylhydroquinone, ethylhydroquinone, nitrohydro Quinone, aminohydroquinone, methoxyhydroquinone, hydroquinonesulfonic acid, 2,5-dihydroxybenzoic acid, 2,5-dimethylhydroquinone, 2,6-dimethylhydroquinone, 2,6-diethylhydroquinone, 2,3-dimethoxy-5-methyl Hydroquinone, 2,5-diaminohydroquinone, 2,6-diaminohydroquinone, 2,5-dinitrohydroquinone, trimethylhydroquinone, tetramethylhydroquinone, pyrogallol (1,2,3-benzenetriol), 4-methylpyrogallol, 5-methyl Pyrogallol, 5-ethyl pyrogallol, 4-nitropyrogallol, 5-nitropyrogallol, pyrogallol-5-sulfonic acid, pyrogallol-4-carboxylic acid, gallic acid (3,4,5-trihydroxybenzoic acid), 4,5- Jime Lupyrogallol, 4,6-dimethylpyrogallol, 4,6-diaminopyrogallol, hydroxyquinol, 3-methyl-1,2,5-benzenetriol, 5-methyl-1,2,4-benzenetriol, phloroglucinol ( Benzene-1,3,5-triol), methylphloroglucinol, phloroglucinol carboxylic acid (2,4,6-trihydroxybenzoic acid), 1,2,3,4-tetrahydroxybenzene, 1,2, Examples include 3,5-tetrahydroxybenzene, hexahydroxybenzene, bis (3,4-dihydroxyphenyl) methane, 2,2-bis (3,4-dihydroxyphenyl) propane, and the like. Here, a polyhydric phenol compound (B) may be used individually by 1 type, or may be used together 2 or more types.

Although the polyhydric phenol compound (B) which can be used for the metal surface treating agent of the present invention is not particularly limited, in the polyhydric phenol compound (B), Z in the formula (1) is a hydrogen atom or a methyl group. The polyhydric phenol compound (B) which is a group selected from ethyl group, hydroxyl group, sulfone group, nitro group, carboxyl group, methoxy group and amino group is preferred.
In the polyphenol compound (B), Z in the formula (1) is a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group. The polyhydric phenol compound (B) in which the benzene ring has 2 or 3 hydroxyl groups is more preferable.
Furthermore, in the polyhydric phenol compound (B), Z in the formula (1) is a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group. The polyphenol compound (B) in which the benzene ring has two hydroxyl groups is most preferable.

  Although the density | concentration of the polyhydric phenol compound (B) mix | blended with the metal surface treating agent of this invention does not have a restriction | limiting in particular, Preferably it is 10-10,000 mg / L, More preferably, it is 50-8,000 mg / L. It is. When the concentration of the polyhydric phenol compound (B) is 10 mg / L or more, the effects described later are more easily exhibited. Moreover, the film formation of a metal compound (A) becomes easier as the density | concentration of a polyhydric phenol compound (B) is 10,000 mg / L or less.

  Between the metal compound (A) and the polyhydric phenol compound (B) contained in the metal surface treatment agent, the “polyhydric phenol compound” with respect to the “concentration (mg / L) of the metal element derived from the metal compound (A)” The ratio (B / A) of (B) concentration (mg / L) is not particularly limited, but if B / A is 0.05 or more, the adhesion is further improved.

  The metal surface treatment agent of the present invention may contain a metal compound such as Zn, Al, Fe, V, Mo, W, Mn, and Ni, in addition to the metal compound (A).

  The metal surface treating agent of the present invention may contain a general inorganic acid or organic acid, and may be anything as long as it contributes to the etching reaction of the metal material to be treated. Examples of inorganic acids include nitric acid, nitrous acid, sulfuric acid, hydrochloric acid, hydrofluoric acid, and the like. Examples of organic acids include formic acid, acetic acid, lactic acid, ascorbic acid, citric acid, gluconic acid, tartaric acid, malic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, oxalic acid, malonic acid, succinic acid, etc. Is mentioned.

  Furthermore, the metal surface treatment agent of the present invention may contain a chelating agent. Examples of the chelating agent include EDTA (ethylenediaminetetraacetic acid), HEDTA (hydroxyethylethylenediaminetriacetic acid), NTA (nitrilotriacetic acid), DTPA (diethylenetriaminepentaacetic acid), TTHA (triethylenetetraminehexaacetic acid), and DHEG (dihydroxyethyl). Glycine), iminodiacetic acid, tricine, tartaric acid, malic acid, citric acid, glycolic acid, lactic acid, gluconic acid, mucoic acid, quinic acid, taurine, EDTMP (ethylenediaminetetramethylenephosphonic acid), NTMP (nitrilotrimethylenephosphonic acid), HEDP (hydroxyethylidene diphosphonic acid) etc. are mentioned.

  In general, industrial water is used as the metal surface treatment agent, and various impurities are contained depending on the water source of the industrial water. For example, industrial water generally contains so-called hardness components such as Ca and Mg, but when the content of the hardness component is large, the chemical treatment of the metal surface treatment agent is effective. In order to have an adverse effect, the water quality can be stabilized by adding a chelating agent. Furthermore, in the process of chemical conversion treatment with the metal surface treatment agent, the metal is eluted as metal ions by the etching reaction of the metal material to be treated. For example, when the metal material is iron, iron ions are eluted. The eluted iron ions eventually become insoluble iron hydroxide with time and become sludge. In order to suppress this phenomenon, the application of a chelating agent is effective.

  Furthermore, the metal surface treatment agent of the present invention may contain a water-soluble or water-dispersible resin.

<Liquid>
The pH of the metal surface treatment agent of the present invention must be 2-7. The pH is more preferably 2.5 to 6.5. If the pH is less than 2, the metal material to be treated is excessively etched, so that the uniform coating property of the film is impaired. If the pH is more than 7, a sufficient film amount cannot be obtained, so that the corrosion resistance decreases. . In addition, pH in this specification and a claim is the value measured with the commercially available pH meter about the agent of 25 degreeC.

≪Metal surface treatment method and film≫
The metal surface treatment method of the present invention includes a step of bringing a metal material that is a metal to be treated into contact with the metal surface treatment agent of the present invention by a method such as immersion or spraying. That is, the metal surface treatment method of the present invention is a method of forming a film mainly containing a metal derived from the metal compound (A) on a metal material to be treated by a chemical conversion reaction.

  In the treatment method of the present invention, a metal film can be deposited by cathodic electrolysis in addition to a chemical conversion reaction without energization. That is, immediately after immersing the metal material to be treated in the metal surface treatment agent of the present invention, a voltage may be applied for cathodic electrolysis treatment, or after immersion for a certain period of time without conducting electricity, the cathode is subjected to a chemical reaction. A voltage may be applied for electrolytic treatment.

  Although the temperature in the metal surface treatment of the metal surface treatment agent according to the present invention is not particularly specified, it is preferably 15 to 60 ° C, and more preferably 20 to 50 ° C.

  The treatment time of the present invention is not particularly defined, but is preferably 10 to 600 seconds, and preferably 15 to 300 seconds. When processing time is less than a minimum, the precipitation amount of the film | membrane originating in a metal compound (A) will fall, and sufficient corrosion resistance will not be obtained.

<Applicable metal materials>
The metal material applicable to the metal surface treating agent of the present invention is not particularly limited. Examples of metal materials include cold-rolled steel sheets, hot-rolled steel sheets, high-tensile steel sheets, hot stamped steel sheets, galvanized steel sheets (including alloyed hot-dip galvanized steel sheets, hot-dip galvanized steel sheets, electrogalvanized steel sheets, etc.), aluminum Materials, magnesium materials and the like.

<Film>
The metal surface treatment film according to the present invention is obtained by the metal surface treatment method of the present invention using the metal surface treatment agent of the present invention. By the way, when the metal of the metal compound (A) is Bi, a film is formed by a different precipitation mechanism as compared with metals other than Bi, that is, Zr, Ti, or Hf.

  When the metal of the metal compound (A) is Bi, Bi used in the present invention is presumed to exist in the form of a trivalent Bi ion (including a complex and the like) in the treatment liquid. This trivalent Bi ion has a potential higher than the standard electrode potential of steel, galvanized steel sheet, aluminum alloy, etc., which are general metal materials to be treated, and is a noble metal Bi and a base metal. A redox reaction occurs with a certain metal material to be treated. That is, the metal is dissolved by the anode reaction of the base metal material, and the electrons released by the dissolution reaction reduce trivalent Bi ions in the treatment liquid, and Bi is reduced on the surface of the metal material to be treated. It will be deposited.

  On the other hand, when the metal of the metal compound (A) is Zr, Ti, or Hf, the metal is dissolved in the metal surface treatment liquid by the anode reaction of the metal material to be treated. Will be released inside. The hydrogen ions in the metal surface treatment liquid are reduced by receiving the electrons, and the hydrogen ions are consumed. As a result, the pH of the surface of the metal material to be treated is relatively higher than that of the bulk (not the interface of the metal surface treatment liquid), so that Zr, Ti or Hf is insoluble in hydroxide. Is formed and precipitated on the surface of the metal material to be treated.

  Two or more metal compounds (A) may be used in combination for the metal compound (A). For example, in the case where Bi and Zr are used in combination, the reaction that occurs when Bi ions receive the electrons and when the hydrogen ions receive the electrons occurs due to the anodic reaction of the metal material to be processed. become. When Bi ions receive electrons, Bi is reduced and deposited on the metal material to be treated. In addition, when hydrogen ions receive electrons, a pH increase occurs at the surface interface of the metal material to be treated, and accordingly, Zr ions form an insoluble salt with hydroxide ions, It will precipitate out.

  It was found that the polyhydric phenol compound (B) has a function of enhancing the uniform coverage of the film in the film deposition process of the metal element derived from the metal compound (A). As described above, the first step in the film deposition process of the chemical conversion film is a dissolution reaction of the metal material to be treated. However, a uniform metal dissolution reaction does not occur on the entire surface of the metal surface. Since the dissolution of the metal becomes easier, a non-uniform film is formed. Here, when the polyhydric phenol compound (B) is applied to the metal surface treatment liquid, it is assumed that the polyhydric phenol compound (B) has an inhibitory function. By acting like an inhibitor, active sites rich in reactivity on the surface of the metal material to be treated are quickly blocked. It is presumed that since the uniformity of the dissolution reaction of the metal material to be treated is further enhanced by the blocking of the active site, the uniform coverage of the film on the metal surface is also enhanced. By increasing the uniform coverage of the film, the metal material after the metal surface treatment has excellent corrosion resistance.

  In recent years, for example, in the automobile industry, the weight of vehicles has been reduced in order to reduce the environmental load, and the use of high-tensile steel plates and hot stamped steel plates (hot steel plates) is increasing as metal materials used. As described above, these metal materials generally tend to be inferior in corrosion resistance as compared with ordinary cold-rolled steel sheets and the like. This is because, for example, in the case of a high-tensile steel plate, Si and Mn added for imparting mechanical properties are concentrated on the metal surface of the high-tensile steel plate, resulting in uneven metal surface properties. It is considered that a uniform film cannot be formed on the metal surface of the tensile steel plate. However, when the polyhydric phenol compound (B) of the present invention is applied, the surface activity at the active site rich in reactivity on the metal surface of the metal to be treated is suppressed. Therefore, when the phenol compound (A) is applied to the metal surface treatment liquid, a uniform dissolution reaction of the metal surface in the metal material is promoted, so that a metal film having excellent coverage on the metal surface can be obtained. Therefore, the metal material has excellent corrosion resistance.

Moreover, the metal structure is manufactured by performing various processes such as cutting, welding, and bending. The structure includes a processing part called a burr part or an edge part generated by cutting or the like, or a welding part in which a thick surface oxide film or the like is locally formed in the vicinity of the welding due to the influence of welding or the like. become. And these processed parts have a non-uniform nature of the metal surface compared to general metal materials that are not processed, so these processed parts are general metal that is not processed The corrosion resistance is often inferior compared to the material. However, by using the metal surface treating agent of the present invention, it is possible to form a uniform film even in such a processed portion, and thus has excellent corrosion resistance.
〔Example〕

  Examples are given below together with comparative examples to specifically describe the effects of the surface treatment liquid, the surface treatment method, and the surface-treated metal material of the present invention. In addition, the to-be-processed metal plate, degreasing agent, and coating material used in the examples are arbitrarily selected from commercially available materials, and the actual use of the surface treatment liquid and the surface treatment method of the present invention is as follows. It is not limited.

<Production of metal surface treatment agent>
Example 1
Fluorozirconic acid was used as a supply source of Zr as the metal compound (A), and Zr was added so that the final concentration was 200 mg / L. Further, hydroquinone was finally added to 500 mg / L and nitric acid was finally added to 1000 mg / L. For pH adjustment, nitric acid or ammonia water was used to adjust to a predetermined pH. The metal surface treating agent of Example 1 is shown in Table 1A.

Examples 2-34
In the same manner as in Example 1, metal surface treatment agents of Examples 2-34 shown in Table 1A were prepared. In addition, only in Example 34, a metal surface treating agent was prepared by adding polyallylamine (PAA) having a molecular weight of 3000 as a water-soluble resin.

Examples 35-53
In the same manner as in Example 1, metal surface treatment agents of Examples 35 to 53 shown in Table 1A were produced. In addition, fluorotitanic acid was used as a supply source of Ti which is a metal compound (A).

Examples 54-56
Bismuth oxide was used as a source of Bi as the metal compound (A). First, HEDTA having a molar mass three times that of Bi was dissolved in deionized water. Next, bismuth oxide was dissolved so as to have a Bi concentration shown in Table 1B. Furthermore, the zirconium concentration shown in Table 1B was adjusted by using fluorozirconic acid as a supply source of Zr as the metal compound (A). About the other, the metal surface treatment chemical | medical agent shown to Table 1B was produced using the method similar to Example 1. FIG.

Example 57
Bismuth oxide was used as a source of Bi as the metal compound (A). First, HEDTA having a molar mass three times that of Bi was dissolved in deionized water. Next, bismuth oxide was dissolved so that the Bi concentration was finally 100 mg / L. Further, hydroquinone was added so that the final concentration was 500 mg / L. For the pH adjustment, nitric acid or aqueous ammonia was used to adjust the pH to a predetermined value, and metal surface treatment agents shown in Table 1B were obtained.

Examples 58-90
A metal surface treating agent was produced in the same manner as in Example 57 except that the polyhydric phenol compound (B) shown in Table 1B was used.

Comparative Examples 1 and 2
The metal compound (A) was not used, and the polyhydric phenol compound (B) shown in Table 1B was used. A treatment liquid was prepared in the same manner as in Example 1 except that the composition of the metal surface treatment agent shown in Table 1B was used.

Comparative Examples 3-5
The polyhydric phenol compound (B) was not used, and the metal compound (A) shown in Table 1B was used. The same supply source as Zr, Ti, and Bi was used. A metal surface treatment agent was produced in the same manner as in Example 1 except that the composition of the metal surface treatment agent shown in Table 1B was used.

Comparative Examples 6-8
Instead of the polyhydric phenol compound (B), phenol having one hydroxyl group bonded to one benzene ring was used. The source of Zr, Ti, and Bi as the metal compound (A) was the same as that used in the example, and the treatment was performed in the same manner as in Example 1 except that the composition of the metal surface treatment agent shown in Table 1B was used. A liquid was prepared.

Comparative Example 9
A metal surface treating agent was prepared in the same manner as in Example 1 except that the composition of the metal surface treating agent shown in Table 1B was used and the pH of the treating agent was adjusted to 1.5 with nitric acid.

Comparative Examples 10 and 11
The composition of the metal surface treatment agent shown in Table 1B, except that the pH of the treatment agent was adjusted to 1.5 with nitric acid for Comparative Example 10 and 7.2 to aqueous ammonia for Comparative Example 11, A metal surface treating agent was produced in the same manner as in Example 58.

Comparative Example 12
A metal surface treatment composition described in Example 1 of Japanese Patent Application Laid-Open No. 2007-262577 was prepared.

Comparative Example 13
A zinc phosphate treatment, which is a conventional metal surface treatment agent, was used. “PB-L3020” manufactured by Nippon Parkerizing Co., Ltd. was used as the zinc phosphate treating agent.

<Metal material>
The following metal materials were prepared as test materials.
-Cold rolled steel sheet: SPCC (JISG 3141), 70 x 150 x 0.8 mm
・ High tensile steel plate: SPFC980Y (JISG3135), 70 × 150 × 1.2 mm
・ Alloyed hot-dip galvanized steel sheet: GA (JISG3302), 70 x 150 x 0.8 mm
・ Hot rolled material: SS400 (JISG3101), 70 × 150 × 0.8 mm
・ High-tensile hot-rolled steel sheet: SPH590 (JISG3131), 70 × 150 × 1.6 mm
Hereinafter, the cold-rolled steel sheet is represented as SPC, the high-tensile steel sheet as high tensile steel, the galvannealed steel sheet as GA, the hot-rolled material as SS, and the high-tensile hot-rolled steel sheet as SPH.

<Degreasing treatment>
Oil such as rust preventive oil may adhere to the test material, and degreasing treatment was performed as a pre-stage of metal surface treatment with a metal surface treatment agent. “FC-E2001” which is an alkaline degreasing agent manufactured by Nippon Parkerizing Co., Ltd. was used. After mixing FC-E2001A with 13 g / L and FC-E2001B with 7 g / L industrial city water and heating to 40 ° C., the test material was degreased by spraying for 120 seconds. Then, after washing with water by spraying for 30 seconds, metal treatment with the metal surface treatment agent shown in Examples and Comparative Examples was performed in the next step.

<Surface treatment with metal surface treatment agent>
The test material cleaned by the degreasing treatment was subjected to surface treatment using the metal surface treatment agents shown in Examples 1 to 90 and Comparative Examples 1 to 13. About the metal surface treatment agent shown in Examples 1-90 and Comparative Examples 1-12, after heating the metal surface treatment agent to 40 ° C., the cleaned metal material was immersed for 60 seconds to form a film. . Thereafter, the metal material was taken out of the metal surface treatment agent, washed with deionized water, and then dried by removing moisture with an air blow. For the zinc phosphate treating agent of Comparative Example 13, a metal material that was cleaned by degreasing after adjusting the free acidity (FA) of the zinc phosphate treating agent to 0.9 pt and the accelerator concentration (AC) to 4.0 pt. Was immersed in “PL-X” manufactured by Nihon Parkerizing Co., Ltd. for 30 seconds, and then the test material was immersed in a zinc phosphate treating agent at a temperature of 40 ° C. for 120 seconds to form a zinc phosphate coating. Then, after taking out from the phosphate treating agent, it was washed with deionized water and then dried by removing moisture with an air blow.

<Measurement of metal adhesion>
The amount of metal deposited on the test material after the chemical conversion treatment with the metal surface treatment agent was measured by fluorescent X-ray spectroscopic analysis (XRF).

<Evaluation of uniform coverage of metal film>
The uniform coverage of the metal film deposited on the metal material after the chemical conversion treatment was calculated using an XPS apparatus.
Measuring instrument: ESCA850 manufactured by Shimadzu Corporation
X-ray source: MgKα (8 kV-30 mA)
Sputtering: Ar sputter measurement depth:
Surface layer: 1 layer (1st layer)
First etching layer (1.2 second etching): 4 layers (2nd to 5th layers)
Second etching layer (etching for 2.4 seconds): 4 layers (sixth layer to ninth layer)
Third etching layer (etching for 4.8 seconds): 7 layers (10th to 16th layers)
16 layers in total (1st to 16th layers)
Measuring element: Metal derived from metal compound (A), Fe, Zn, C, O (however, Zn is measured only when the metal material is GA)

  Under the above measurement conditions, the atomic concentration of each element in the surface layer and each etching layer (depth direction) is measured. For the metal derived from the metal compound (A), the concentrations detected in the surface layer and each etching layer (16 layers in total) are integrated (this is X). Further, the concentrations detected from the surface layer to the fifth layer are integrated (this is assumed to be Y). When Y / X (uniform coverage:%), the higher the value, the higher the uniform coverage of the deposited metal film.

<Cation electrodeposition coating>
Cationic electrodeposition coating was performed on the metal materials subjected to the coating treatment with the metal surface treatment agents of Examples 1 to 90 and Comparative Examples 1 to 13. As the cationic electrodeposition coating, GT-100 manufactured by Kansai Paint Co., Ltd. was used. In the state where the metal material was immersed in a cationic electrodeposition coating bath, a constant voltage cathodic electrolysis was performed for 180 seconds to deposit a cationic electrodeposition coating film on the test material after the film treatment. Then, after washing with water and deionized water, the cation electrodeposition coating film was cured by heating and baking at 170 ° C. for 20 minutes. The film thickness of the cationic electrodeposition coating was adjusted to 15 μm.

<Corrosion resistance test method and evaluation method>
Salt water immersion test (SDT)
The test plate subjected to the cationic electrodeposition coating was cross-cut using a cutter knife, and immersed in a 5% by mass sodium chloride aqueous solution heated to 55 ° C. for 240 hours. Further, in order to evaluate the performance under severe conditions, immersion was also performed for 480 hours. After dipping, it was washed with tap water, and water was removed with a cloth or the like. Next, the cross cut part was peeled off with an adhesive tape, the maximum peel width on one side of the coating film was measured, and the SDT performance was evaluated according to the following criteria.
◎ +: Less than 1 mm ◎: 1 mm or more and less than 2 mm ○: 2 mm or more and less than 3 mm Δ: 3 mm or more and less than 5 mm x: 5 mm or more

Water resistance secondary adhesion test (adhesion)
The test plate subjected to the cationic electrodeposition coating was immersed in deionized water at 40 ° C. for 240 hours. After completion of the immersion, moisture was removed with a cloth or the like, and then 100 grids at intervals of 2 mm were cut using a cutter knife. After peeling the cross section with an adhesive tape, the number of cross cuts of the coating film was calculated, and the adhesion was evaluated according to the following criteria.
○: 0 △: 1 to 10 ×: 11 or more

<Consideration of performance evaluation of Examples and Comparative Examples>
In the coating performance evaluation used in the present invention, those having an evaluation of Δ or more can be said to have performance at a level with no practical problem. That is, Examples 1 to 90 showed good performance at all levels, while Comparative Examples 1 to 13 had x evaluations at all treatment levels except the evaluation of the GA material of Comparative Example 13. However, sufficient corrosion resistance was not obtained. In Comparative Examples 1 and 2, since there is no metal compound (A), it is considered that the metal film was not formed in the first place, and neither the SDT performance nor the adhesion performance was obtained. Although Comparative Examples 3 to 5 have metal film formation, sufficient performance is not obtained for both SDT performance and adhesion performance, but this is because there is no polyhydric phenol compound (B), and film formation with high coverage is achieved. It is thought that the effect was not made. In Comparative Examples 6 to 8, instead of the polyhydric phenol compound (B), phenol having one hydroxyl group bonded per benzene ring was applied. For improving the coverage of the metal compound (A), It does not contribute at all, and it is considered that sufficient corrosion resistance and adhesion were not obtained. In Comparative Examples 9 and 10, since the pH of the treatment agent was 1.5, the etching of the metal material was excessive, and as a result, the film formation was inferior in uniform coverage, so that the corrosion resistance was inferior. . In Comparative Example 11, since the pH of the treatment agent was 7.2, a sufficient amount of the metal film was not obtained, and the performance was inferior particularly in SDT evaluation under severe conditions. Comparative Example 12 was treated with the metal surface treatment composition of Example 1 described in Japanese Patent Application Laid-Open No. 2007-262577. Both SPC material and other metal materials SS material and SPH material are particularly SDT materials. The performance was insufficient under harsh conditions. Comparative Example 13 is a zinc phosphate treatment with a sufficient market performance and has a sufficient performance in normal SDT evaluation, but the performance is inferior under severe conditions, but this is a zinc phosphate coating in an alkaline environment. In this case, since the film has a characteristic to dissolve, it is considered that the performance deteriorated because the zinc phosphate film probably disappeared by dissolution after prolonged immersion.

  ADVANTAGE OF THE INVENTION According to this invention, the coating material which has the outstanding corrosion resistance also with respect to various metal materials can be provided using the processing liquid with little environmental impact.

Claims (4)

At least one metal compound (A) selected from the group consisting of Zr, Ti, Hf and Bi as a metal element and a polyhydric phenol compound (B) represented by the formula (1) are added, and the pH is 2 to 2 7 is a metal surface treatment agent.

[However, X _{1 to} X ₃ in the formula (1) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group. , Z is a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, an amino group and a group represented by the formula (2). ]

[X _{4 to} X ₆ in the formula (2) are each independently a hydrogen atom or a group selected from a methyl group, an ethyl group, a hydroxyl group, a sulfone group, a nitro group, a carboxyl group, a methoxy group, and an amino group; And R2 are each independently a hydrogen atom or a methyl group. ]   The metal surface treating agent according to claim 1, wherein the metal compound (A) is added in an amount of 10 to 5000 mg / L as the total concentration of the metal elements.   The metal surface treating agent according to claim 1 or 2, wherein the polyphenol compound (B) is added at a concentration of 10 to 10,000 mg / L.   After the metal material to be treated whose surface has been cleaned in advance is brought into contact with the metal surface treatment agent according to any one of claims 1 to 3, at least one selected from a chemical reaction step and an electrolytic chemical reaction step A metal surface treatment method for forming a film on the surface of the metal material to be treated by a process.