Chemical conversion treatment agent

Abstract

The purpose of the present invention is to provide a chemical conversion treatment agent for forming a chemical conversion film on the surface or on the surface of a metal material, the chemical conversion treatment agent having excellent appearance and corrosion resistance after chemical conversion treatment, the corrosion resistance being evaluated by the post-coating exposure test, VDA621-415 method, etc. And the chemical conversion treatment agent can be used in a wide temperature range. The problem is solved by a chemical conversion treatment agent for forming a chemical conversion coating film on the surface of a metal material or on the surface of the metal material, the chemical conversion treatment agent satisfies formula (1) and is blended with a supply source of fluorine ions, a supply source A containing zirconium ions, a supply source B containing aluminum ions, and a water-soluble or water-dispersible polymer containing 90% or more by mole of a structural unit represented by formula (i) or a salt C thereof. (Ac + Bc) * (pH-3) x > = 0.38 (In formula (1), X = 7.2 * 12 (-16 * (Ac + Bc)). # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a chemical conversion treatment agent for forming a chemical conversion film on the surface or on the surface of a metal material. Background Art

[0002] Conventionally, treatment liquids for metal surface treatment that can perform surface treatment with excellent corrosion resistance and good adhesion have been developed. For example, Patent Document 1 discloses a composition for surface treatment of aluminum, aluminum alloy, magnesium, or magnesium alloy, which is characterized by containing: Compound A, containing at least one metal element selected from Hf(IV), Ti(IV), and Zr(IV); a sufficient amount of a fluorine-containing compound such that fluorine is at least 5 times the molar concentration of the total molar concentration of the metals contained in Compound A present in the composition; at least one metal ion B selected from alkaline earth metals; at least one metal ion C selected from Al, Zn, Mg, Mn, and Cu; and nitrate ions.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: International Publication No. 03 / 074761. Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in addition to adhesion and corrosion resistance, appearance is also emphasized as work completion. In addition, in corrosion resistance tests, exposure tests and corrosion tests close to actual environmental conditions have been emphasized in recent years compared to general salt spray tests (SST), JASO-M609 method, etc. Furthermore, from the viewpoint of reducing the environmental load, lowering the chemical conversion treatment temperature is also emphasized. On the other hand, in conventional surface treatment technologies, there is no technology that takes into account both the appearance and corrosion resistance after chemical conversion treatment.

[0008] An object of the present invention is to provide a chemical conversion treatment agent for forming a chemical conversion film on the surface or on the surface of a metal material, which has excellent appearance and corrosion resistance after chemical conversion treatment, the above corrosion resistance is evaluated by exposure tests after painting, VDA621-415 method, etc., and the chemical conversion treatment agent can be used in a wide temperature range.

[0009] Solutions to the Problems

[0010] The present inventors have conducted in-depth research to solve the above problems and, as a result, have found that a chemical conversion treatment agent containing a supply source of fluoride ions, a supply source A of zirconium-containing ions, a supply source B of aluminum-containing ions, and a specific water-soluble or water-dispersible polymer or its salt C can form a chemical conversion film having excellent corrosion resistance and appearance after chemical conversion by satisfying specific parameters, thus completing the present invention.

[0011] The present invention includes the following:

[0012] [1] A chemical conversion treatment agent that forms a chemical conversion film on the surface or on the surface of a metal material,

[0013] The above chemical conversion treatment agent satisfies the following formula (1) and is formulated with:

[0014] A supply source of fluoride ions;

[0015] A supply source A of zirconium-containing ions;

[0016] A supply source B of aluminum-containing ions; and

[0017] A water-soluble or water-dispersible polymer or its salt C, containing 90% or more of the structural unit represented by the following formula (i) in terms of molar conversion,

[0018] (Ac + Bc) × (pH - 3) x ≥0.38... Formula (1)

[0019] where X = 7.2 × 12 (-1.6×(Ac+Bc)) ,

[0020] [Chemical formula 1]

[0021]

[0022] Here, in the above formula (1), Ac is the concentration of zirconium element from the supply source A in the above chemical conversion treatment agent, and the above Ac is 0.02 g / L or more and 2 g / L or less,

[0023] Bc is the concentration of aluminum element from the supply source B in the above chemical conversion treatment agent, and the above Bc is 0.02 g / L or more and 2 g / L or less,

[0024] The ratio Bc / Ac of Bc to Ac is 0.03 or more and 10.0 or less,

[0025] The concentration of the above polymer or its salt C in the above chemical conversion treatment agent is 0.0001 g / L or more and (0.16 × Ac + 0.23) g / L or less,

[0026] The pH is the pH of the above chemical conversion treatment agent, and the above pH is 3.8 or more and 6.0 or less;

[0027] [2] The chemical conversion treatment agent according to [1], wherein the above metal material is at least one or more of iron materials, galvanized materials or galvanized series materials, aluminum materials, aluminum alloy materials, aluminized series materials, magnesium materials, and magnesium alloy materials; etc.

[0028] Advantages of the Invention

[0029] According to the present invention, it is possible to provide a chemical conversion treatment agent for forming a chemical conversion film on the surface or on the surface of a metal material, which has excellent appearance and corrosion resistance after chemical conversion treatment. The above corrosion resistance is evaluated by exposure tests after painting, the VDA621-415 method, etc., and the chemical conversion treatment agent can be used in a wide temperature range. Detailed Embodiments

[0030] In this specification, the numerical range expressed by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, and "A~B" means A or more and B or less.

[0031] Hereinafter, a chemical conversion treatment agent according to an embodiment of the present invention will be described.

[0032] (Chemical Conversion Treatment Agent)

[0033] The chemical conversion treatment agent of this embodiment is prepared by blending a specified amount of a fluoride ion supply source, a zirconium-containing ion supply source A, an aluminum-containing ion supply source B, and a water-soluble or water-dispersible polymer or its salt C having a structural unit represented by formula (i) in a molar conversion of 90% or more in an aqueous medium. By using this chemical conversion treatment agent, it is possible to form a chemical conversion film with excellent corrosion resistance after painting and film appearance on a metal material.

[0034] The chemical conversion treatment agent of this embodiment may be a chemical conversion treatment agent that only blends a fluoride ion supply source, supply source A, supply source B, and a specified polymer or its salt C in an aqueous medium, or a chemical conversion treatment agent that further blends other components.

[0035] (Fluoride Ion Supply Source)

[0036] The chemical conversion treatment agent of this embodiment is combined with a supply source of fluoride ions. The supply source of fluoride ions is not particularly limited as long as it is a compound that can supply fluoride ions when combined with the chemical conversion treatment agent (hereinafter referred to as "fluorine-containing compound"). Examples of the fluorine-containing compound include, but are not limited to, zirconium hexafluoride, hexafluorotitanic acid, hafnium hexafluoride, hydrofluoric acid, ammonium fluoride, ammonium bifluoride, germanium fluoride, potassium fluoride, potassium bifluoride, iron fluoride, fluorosilicic acid, sodium fluoride, sodium bifluoride, etc. In addition, compounds containing zirconium and fluorine such as zirconium hexafluoride can supply both zirconium-containing ions and fluoride ions. In addition, various fluorine-containing compounds can be combined with only one kind, or two or more kinds can be combined.

[0037] There is no particular limitation on the compounding amount of the fluorine-containing compound, and it can be set to a level that has no influence on the formation of the chemical conversion film. Specifically, it is preferably compounded in such a way that the concentration of fluoride ions becomes the sum of 4 to 8 times the molar concentration of zirconium element contained in the chemical conversion treatment agent and 2 to 4 times the molar concentration of aluminum element contained in the chemical conversion treatment agent. By compounding the fluorine-containing compound within this range, the concentration of free fluoride ions during treatment becomes appropriate, and the reaction rate between the metal material and the chemical conversion treatment agent becomes suitable. As a result, the amount of the formed film becomes appropriate.

[0038] (Supply source A)

[0039] The chemical conversion treatment agent of this embodiment is combined with supply source A. Supply source A is not particularly limited as long as it is a compound that can supply zirconium-containing ions (hereinafter referred to as "zirconium-containing ions") when combined with the chemical conversion treatment agent. Therefore, the chemical conversion treatment agent of this embodiment contains zirconium-containing ions. Examples of zirconium-containing ions include: metal ions of zirconium; complex ions containing zirconium; oxide ions of zirconium, etc.

[0040] Specific examples of supply source A as a supply source of zirconium-containing ions include zirconium hexafluoride, zirconium nitrate, zirconyl nitrate, zirconium carbonate, zirconium hydroxide, zirconium oxide, etc. These supply sources can be combined with only one kind, or two or more kinds can be combined.

[0041] The concentration of zirconium-containing ions in the chemical conversion treatment agent is not particularly limited. The concentration Ac of zirconium element from supply source A in the chemical conversion treatment agent is usually 0.02 g / L or more, preferably 0.05 g / L or more, and usually 2 g / L or less, preferably 1.5 g / L or less. When two or more supply sources A are combined with the chemical conversion treatment agent, Ac refers to the total concentration of zirconium element from them.

[0042] By making the zirconium element concentration Ac within the above range, Zr in the chemical conversion film can be an effective amount.

[0043] (Supply source B)

[0044] The chemical conversion treatment agent of this embodiment is combined with a supply source B. The supply source B is not particularly limited as long as it can supply a compound containing aluminum ions (hereinafter referred to as "aluminum-containing ions") when combined with the chemical conversion treatment agent. Therefore, the chemical conversion treatment agent of this embodiment contains aluminum-containing ions. Examples of the aluminum-containing ions include, for example: metal ions of aluminum; complex ions containing aluminum; oxide ions of aluminum, etc. Specific examples of the supply source B of the aluminum-containing ions include aluminum hydroxide, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum oxide, etc., but are not limited to these. In addition, when they can take the form of salts, they can be their salts. These supply sources can be combined with only one kind, or two or more kinds can be combined.

[0045] The concentration of aluminum-containing ions in the chemical conversion treatment agent is not particularly limited. The concentration Bc of aluminum element from the supply source B in the chemical conversion treatment agent is usually 0.02 g / L or more, preferably 0.05 g / L or more. In addition, it is usually 2 g / L or less, preferably 1.5 g / L or less. When two or more supply sources B are combined with the chemical conversion treatment agent, Bc refers to the total concentration of aluminum element from them.

[0046] By making the aluminum element concentration Bc within the above range, the concentration of free fluoride ions in the chemical conversion treatment agent can be made appropriate.

[0047] (Ratio of supply source A to B)

[0048] The ratio (Bc / Ac) of the concentration Bc of aluminum element from the supply source B to the concentration Ac of zirconium element from the supply source A in the chemical conversion treatment agent is usually 0.03 or more and usually 10.0 or less.

[0049] (Water-soluble or water-dispersible polymer or its salt C)

[0050] The chemical conversion treatment agent of this embodiment contains a water-soluble or water-dispersible polymer or its salt C (hereinafter simply referred to as "polymer C"). The polymer C is not particularly limited as long as it is a polymer having a structural unit represented by the above formula (i) in a molar conversion of 90% or more. Specifically, examples of the polymer C include: diallylamine polymers; salts of diallylamine polymers such as diallylamine hydrochloride polymers, diallylamine sulfate polymers, and diallylamine acetate polymers, etc., poly diallylamines.

[0051] The degree of polymerization of the polymer C is not particularly limited. The weight-average molecular weight is usually 1000 or more, preferably 5000 or more. In addition, the weight-average molecular weight is a value measured by GPC (gel permeation chromatography) and converted to polystyrene.

[0052] The content (mixing amount) of polymer C in the chemical conversion treatment agent is usually 0.0001 g / L or more, preferably 0.001 g / L or more, more preferably 0.005 g / L or more, and is (0.16×Ac + 0.23) g / L or less in terms of solid content.

[0053] By setting the content of polymer C within the above range, the adhesion and corrosion resistance of the chemical conversion film are improved.

[0054] (Aqueous medium)

[0055] The chemical conversion treatment agent of the present embodiment may contain an aqueous medium. The aqueous medium is not particularly limited as long as it is water or a mixture of water and a water-miscible organic solvent (containing 50% by volume or more of water based on the volume of the aqueous medium). As the water-miscible organic solvent, any organic solvent that is miscible with water is not particularly limited, and examples include: ketone solvents such as acetone and methyl ethyl ketone; amide solvents such as N,N'-dimethylformamide and dimethylacetamide; alcohol solvents such as methanol, ethanol, and isopropyl alcohol; ether solvents such as ethylene glycol monobutyl ether and ethylene glycol monohexyl ether; pyrrolidone solvents such as 1-methyl-2-pyrrolidone and 1-ethyl-2-pyrrolidone, etc. These water-miscible organic solvents can be mixed with water alone or in combination of two or more.

[0056] (Other components)

[0057] The chemical conversion treatment agent of the present embodiment may incorporate additives commonly used in chemical conversion treatment agents as other components. As other components, examples include: organic acids, oxidants, metal ions other than supply sources A and B, organosilane compounds, metal alkoxides, water-soluble resins or water-dispersible resins other than polymer C, surfactants, pH regulators, etc. In addition, these other components can be incorporated alone or in combination of two or more. Also, these other components can be incorporated within a range that does not impair the effects of the present invention.

[0058] (Organic acid)

[0059] Examples of the organic acids that can be incorporated into the chemical conversion treatment agent of the present embodiment are organic sulfonic acids, organic phosphonic acids, organic phosphoric acids, aliphatic carboxylic acids, and aromatic carboxylic acids, specifically methanesulfonic acid, ethanesulfonic acid, lactic acid, oxalic acid, citric acid, etc., but are not limited to these. The organic acids can be incorporated alone or in combination of two or more.

[0060] (Oxidant)

[0061] Examples of the oxidizing agent that can be incorporated into the chemical conversion treatment agent of the present embodiment include, for example, hydrogen peroxide, nitrate, nitrite, permanganate, chlorate, persulfate, nitro-containing compounds, hypochlorous acid, organic peroxides, and bromate, etc. Hydrogen peroxide, nitrate, and nitrite are preferred, but not limited to these. The oxidizing agent can be incorporated alone or in combination of two or more. In addition, it may or may not contain sulfate ions.

[0062] (Source of metal ions other than sources A and B)

[0063] Examples of the source of metal ions other than sources A and B that can be incorporated into the chemical conversion treatment agent of the present embodiment include, for example, compounds containing copper, iron, manganese, magnesium, nickel, cobalt, zinc, tungsten, etc., but not limited to these. The source of metal ions other than sources A and B can be incorporated alone or in combination of two or more.

[0064] (Organosilane compound)

[0065] Examples of the organosilane compound that can be incorporated into the chemical conversion treatment agent of the present embodiment include, for example, aminosilane compounds, epoxy silane compounds, and alkoxysilane compounds, etc. Specifically, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyldimethylmethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyldiethylethoxysilane, N-2-(aminoethyl)-3-aminopropylethyldiethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyldiethylethoxysilane, 3-aminopropylethyldiethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyldimethylmethoxysilane, 3-glycidoxypropyldiethylethoxysilane, 3-glycidoxypropyltriethoxysilane, etc., but not limited to these. In addition, each organosilane compound in the chemical conversion treatment agent can be in its original form, or in the form of a hydrolyzate obtained by hydrolysis of the organosilane compound, or in the form of a condensate obtained by polycondensation of the hydrolyzate, or in the form of a copolymer (alternating copolymer, random copolymer, block copolymer, graft copolymer, etc.) obtained by copolymerizing the respective hydrolyzates, or in a mixed state of multiple forms.

[0066] (Metal alkoxides)

[0067] Examples of metal alkoxides that can be incorporated into the chemical conversion treatment agent of this embodiment include, but are not limited to: zirconium tetrapropyl alcoholate, zirconium tetraisopropyl alcoholate, zirconium tetra-n-propyl alcoholate, zirconium tetra-n-butyl alcoholate, titanium methoxide, titanium ethoxide, titanium tetraisopropyl alcoholate, titanium tetra-n-butyl alcoholate, titanium butoxide dimer, titanium tetra-2-ethylhexanolate, vanadium(V) triisopropoxide oxide, vanadium butoxide, vanadium(V) triethoxide oxide, aluminum isopropoxide, aluminum tert-butoxide, etc. One type of metal alkoxide can be incorporated alone, or two or more types can be incorporated. In addition, the metal alkoxide in the chemical conversion treatment agent can be in its original form, or in the form of a hydrolyzate of the metal alkoxide, or in the form of a condensate obtained by polycondensation of the hydrolyzate or the hydrolyzate of the organosilane compound, or in the form of a copolymer (alternating copolymer, random copolymer, block copolymer, graft copolymer, etc.) obtained by copolymerizing the respective hydrolyzates or the hydrolyzates of the organosilane compound, or in a mixed form of multiple forms. The metal alkoxide containing zirconium is also treated as supply source A, and the metal alkoxide containing aluminum is also treated as supply source B.

[0068] (Water-soluble resin or water-dispersible resin other than polymer C)

[0069] Examples of water-soluble resins or water-dispersible resins other than polymer C that can be incorporated into the chemical conversion treatment agent of this embodiment include, but are not limited to: poly(meth)acrylic resins, polyurethane resins, acrylic resins, epoxy resins, phenolic resins, amine resins that do not contain the structural unit represented by formula (i), etc. One type of water-soluble resin or water-dispersible resin other than polymer C can be incorporated alone, or two or more types can be incorporated.

[0070] (Surfactant)

[0071] Examples of the surfactant that can be incorporated into the chemical conversion treatment agent of the present embodiment include, for example, nonionic surfactants; ionic surfactants such as cationic, anionic, or amphoteric surfactants. There is no particular limitation on the nonionic surfactant, and examples thereof include polyethylene glycol type nonionic surfactants such as polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene-polyoxypropylene-block polymer; polyol type nonionic surfactants such as sorbitan fatty acid ester; amide type nonionic surfactants such as fatty acid alkanolamide, etc. There is no particular limitation on the cationic surfactant, and examples thereof include amine salt type cationic surfactants such as higher alkyl amine salts and polyoxyethylene higher alkyl amines; quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, etc. There is no particular limitation on the anionicsurfactant, and examples thereof include higher alkyl ether sulfate salts with ethylene oxide added, etc. In addition, the HLB value (calculated by the Griffin method) of the above surfactant is not particularly limited, and is preferably 6 or more and 18 or less, more preferably 10 or more and 14 or less. The above surfactant can be incorporated alone as one kind in the chemical conversion treatment agent of the present embodiment, or two or more kinds can be incorporated. By making the chemical conversion treatment agent of the present embodiment contain the above surfactant, chemical conversion treatment and degreasing treatment can be carried out simultaneously in one step.

[0072] (pH of the chemical conversion treatment agent)

[0073] The pH of the chemical conversion treatment agent of the present embodiment is usually in the acidic to neutral range. Specifically, the pH is in the range of 3.8 to 6.0, more preferably in the range of 4.1 to 5.1.

[0074] Here, the pH value in this specification refers to the value measured at 40 °C using a pH meter.

[0075] The pH of the chemical conversion treatment agent can be adjusted using, for example, acid components such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, boric acid, and organic acids; base components such as lithium hydroxide, potassium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, alkali metal salts, ammonia, ammonium salts, and amines as pH regulators, but are not limited to these components. In addition, one or more kinds of pH regulators can be used.

[0076] (Value of a specific parameter)

[0077] The value on the left side of the following formula (1) is usually 0.38 or more and 10 or less, preferably 0.8 or more and 5 or less. By satisfying formula (1), the effects of the present invention can be exerted.

[0078] (Ac + Bc) × (pH - 3) x≥0.38… Formula (1)

[0079] wherein, X = 7.2 × 12 (-1.6×(Ac+Bc)) .

[0080] (Method for manufacturing chemical conversion treatment agent)

[0081] The chemical conversion treatment agent of the present embodiment can be manufactured by mixing a specified amount of a fluoride ion supply source, supply source A, supply source B, and a specified polymer or its salt C as raw materials in an aqueous medium.

[0082] (Method for forming chemical conversion film)

[0083] The method for forming a chemical conversion film using the chemical conversion treatment agent of the present embodiment includes a contact step of bringing the chemical conversion treatment agent of the present embodiment into contact with the surface of a metal material or on the surface. Thereby, a chemical conversion film is formed on the surface of the metal material or on the surface. As the method of bringing the chemical conversion treatment agent into contact with the metal material, existing contact methods can be cited, such as an immersion treatment method, a spray treatment method, a rinsing treatment method, or a combination of these methods, etc., but it is not limited thereto.

[0084] The contact temperature in the above contact method is preferably in the range of 10°C or higher and 60°C or lower, more preferably in the range of 20°C or higher and 50°C or lower. In addition, in the present embodiment, the range of 10°C or higher and 25°C or lower is set as "low temperature", and the range greater than 25°C and 50°C or lower is set as "high temperature". Furthermore, the contact time is preferably in the range of 30 seconds to 300 seconds, more preferably in the range of 60 seconds to 180 seconds, but is not limited to these times.

[0085] In addition, a pretreatment process can be performed before the process of contacting the chemical conversion treatment agent. Examples of the pretreatment process include: pickling process; degreasing process; alkali cleaning process; chromate chemical conversion treatment process; phosphate chemical conversion treatment process using phosphates such as zinc phosphate and iron phosphate; bismuth displacement plating process, zirconium chemical conversion treatment process, titanium chemical conversion treatment process, hafnium chemical conversion treatment process, vanadium chemical conversion treatment process, etc. In addition, one of these pretreatment processes can be performed, or two or more processes can be combined and performed in sequence. Examples of the combination of two or more processes include the combination of the phosphate chemical conversion treatment process and the chromate chemical conversion treatment process, bismuth displacement plating process, zirconium chemical conversion treatment process, titanium chemical conversion treatment process, hafnium chemical conversion treatment process, or vanadium chemical conversion treatment process. The zirconium chemical conversion treatment process implemented as the pretreatment process can use the chemical conversion treatment agent of the present embodiment or a chemical conversion treatment agent different from the chemical conversion treatment agent of the present embodiment. In addition, in the case of performing the above various pretreatment processes, a water washing treatment process can be performed after each of the various pretreatment processes. In the case of performing the above various pretreatment processes, a water washing treatment process can be performed after each process or after a part of the processes. In addition, in the case of performing the water washing treatment process, a drying process for drying the surface of the metal material can be performed thereafter.

[0086] In addition, in the method for forming a chemical conversion film of the present embodiment, after the contacting process, post-treatment processes such as an alkali washing process, a water washing process, a chromate chemical conversion treatment, a zinc phosphate chemical conversion treatment process, a bismuth displacement plating process, an iron phosphate chemical conversion treatment process, a zirconium chemical conversion treatment process, a titanium chemical conversion treatment process, a hafnium chemical conversion treatment process, a drying process, etc. can be performed. As these post-treatment processes, one process can be performed alone, or two or more processes can be combined and performed in sequence. The zirconium chemical conversion treatment process implemented as the post-treatment process can use the chemical conversion treatment agent of the present embodiment or a chemical conversion treatment agent different from the chemical conversion treatment agent of the present embodiment. In addition, in the case of performing the above various post-treatment processes, a water washing treatment process can be performed after each of the various post-treatment processes. In the case of performing the above various post-treatment processes, a water washing treatment process can be performed after each process or after a part of the processes. In addition, in the case of performing the water washing treatment process, a drying process for drying the surface of the metal material can be performed thereafter.

[0087] In addition, a coating film can also be formed on the chemical conversion coating film formed by the above-described method for forming a chemical conversion coating film, to produce a coated metal material having the chemical conversion coating film and the coating film. In this case, after forming the chemical conversion film, coating film formation treatments such as a coating process for forming the coating film and a drying process for drying the coating on the surface of the coated metal material (which may include a sintering process, a curing process, etc.) can be carried out.

[0088] In addition, before the coating process, a water washing treatment process for washing the surface of the metal material that has come into contact with the chemical conversion treatment agent of the present embodiment can be carried out. Further, a drying process for drying the surface of the metal material that has come into contact with the chemical conversion treatment agent or the surface of the metal material after the water washing treatment process can also be carried out. Furthermore, one or more of the above post-treatment processes can be carried out after the above contact process and before the coating process. In addition, when carrying out the above various post-treatment processes, a water washing treatment process can be carried out after the various post-treatment processes. When carrying out a plurality of various post-treatment processes, a water washing treatment process can be carried out after each process or after a part of the processes. In addition, when carrying out the water washing treatment process, a drying process for drying the surface of the metal material can be carried out after that.

[0089] The above coating process coats the surface of the metal material having the above chemical conversion coating film with a coating material. The coating method is not particularly limited, and known methods can be applied, such as roll coating, electrodeposition coating (e.g., cationic electrodeposition coating, anionic electrodeposition coating, etc.), spraying, thermal spraying, airless spraying, electrostatic (powder) coating, roll coating, curtain flow coating, brush coating, bar coating, dip flow method, and the like.

[0090] Examples of the above coatings include known coatings such as oil-based coatings, cellulose derivative coatings, phenolic resin coatings, alkyd resin coatings, amino alkyd resin coatings, urea resin coatings, unsaturated resin coatings, vinyl resin coatings, acrylic resin coatings, epoxy resin coatings, polyurethane resin coatings, silicone resin coatings, fluororesin coatings, rust-preventive paints, antifouling coatings, powder coatings, cationic electrodeposition coatings, anionic electrodeposition coatings, water-based coatings, and solvent coatings. In addition, in the coating process, various coatings that are the same or different can be used, and one coating can be performed, or two or more coatings can be performed. Further, the drying process is a process of drying and curing the coated coating. Examples of the drying method include natural drying, reduced-pressure drying, convective heat drying (e.g., natural convective heat drying, forced convective heat drying), radiative drying (e.g., near-infrared drying, far-infrared drying), ultraviolet curing drying, electron beam curing drying, vapor curing (Vapor-cure, ベーポキュア), sintering drying, and the like. In addition, one of these drying methods can be implemented, or two or more can be implemented in combination.

[0091] As the above cationic electrodeposition coating, known methods can be applied. Examples include a method of using a cationic electrodeposition coating containing an amine-added epoxy resin and a blocked polyisocyanate curing agent as a curing component as the coating, and immersing a metal material having a chemical conversion film in the coating. The cationic electrodeposition coating is carried out, for example, by maintaining the temperature of the coating at a specified temperature, stirring the coating, and applying a voltage with a rectifier using the metal material having a chemical conversion film as the cathode. By subjecting the above metal material that has undergone cationic electrodeposition coating to water washing and sintering, a coating film can be formed on the chemical conversion film. The sintering is carried out for a certain period of time within a specified temperature range. For example, a method of performing sintering at 170°C for 20 minutes can be cited. In addition, in the case of applying the cationic electrodeposition coating method using a cationic electrodeposition coating, in order to prevent the aggregation of the coating caused by sodium ions, it is preferable to perform the above water washing treatment process using water having a sodium ion concentration of less than 500 ppm based on mass before the coating process.

[0092] As coating methods such as spraying using powder coatings, electrostatic powder coating, and flow dipping method, known methods can be applied. Examples of the powder coating include a powder coating containing a polyester resin, a blocked isocyanate curing agent as a curing agent, a β-hydroxyalkylamide curing agent (e.g., refer to Japanese Patent Application Laid-Open No. 2011-88083), or triglycidyl isocyanurate. The sintering is carried out for a certain period of time within a specified temperature range. For example, a method of performing sintering at 130°C to 250°C for 20 minutes can be cited.

[0093] As coating methods such as spraying, electrostatic coating, and bar coating using the above solvent coatings, well-known methods can be applied. As solvent coatings, for example, solvent coatings containing resins such as melamine resin, acrylic resin, polyurethane resin, polyester resin, and organic solvents such as diluents can be cited. Sintering is carried out for a certain period of time within a specified temperature range. For example, a method of carrying out at 130 °C for 20 minutes can be cited.

[0094] As drying methods for curing the coated paint, for example, the following can be cited: natural drying, vacuum drying, convective heat drying (e.g., natural convection heat drying, forced convection heat drying), radiation drying (e.g., near-infrared drying, far-infrared drying), ultraviolet curing drying, electron beam curing drying, air flow curing, etc. These drying methods can be implemented singly or two or more of them can be combined and implemented.

[0095] The coating film obtained through the coating process can be single-layer or multi-layer. In the case of being multi-layer, the coatings for forming various coating films, the coating methods using the coatings, the drying methods of the coated metal materials, etc. can be the same or different respectively.

[0096] As metal materials, for example, the following can be cited: iron (e.g., cold-rolled steel sheets, hot-rolled steel sheets, high tensile strength steel sheets, tool steel, alloy tool steel, spheroidal graphite cast iron, gray cast iron, etc.); plating materials, for example, galvanized materials and galvanized-based materials (e.g., electro-galvanized, hot-dip galvanized, hot-dip galvanized-aluminum-based, hot-dip galvanized-aluminum-magnesium-based, alloyed hot-dip galvanized, electro-galvanized-based, etc.); aluminum and aluminum alloy materials (e.g., 1000 series aluminum alloy materials, 2000 series aluminum alloy materials, 3000 series aluminum alloy materials, 4000 series aluminum alloy materials, 5000 series aluminum alloy materials, 6000 series aluminum alloy materials, 7000 series aluminum alloy materials, 8000 series aluminum alloy materials, aluminum castings, aluminum alloy castings, die-casting materials, etc.); aluminized-based materials; magnesium and magnesium alloy materials (e.g., AZ91, AZ61, AZ31, etc.).

[0097] For the chemical conversion film formed using the chemical conversion treatment agent of this embodiment, preferably, the total mass of titanium, zirconium, and hafnium contained in the chemical conversion film per unit area is 5 mg / m 2 Above, more preferably 10 mg / m 2 Above, further preferably 20 mg / m 2 Above. As the upper limit value, there is no particular limitation, and it is preferably 800 mg / m 2 Below. In addition, the masses of titanium, zirconium, and hafnium in the chemical conversion film can be measured by using, for example, a fluorescent X-ray analysis device.

[0098] The metal material with a chemical conversion coating may have one or more of the above various coatings (e.g., chromate chemical conversion coating, phosphate chemical conversion coating, bismuth replacement plating coating, etc.) above or below the chemical conversion coating obtained by contacting with the chemical conversion treatment agent of the present embodiment.

[0099] By applying a coating on the surface of a metal material with a chemical conversion coating to form a coating film, a coated metal material with a chemical conversion coating and a coating film can be manufactured. The coated metal material may have a coating film on the surface of the metal material with a chemical conversion coating, or may have a coating film on the surface of one or more of the above various coatings (e.g., chromate chemical conversion coating, phosphate chemical conversion coating, bismuth replacement plating coating, vanadium chemical conversion coating, etc.) further formed on the chemical conversion coating. In addition, the coating film may be composed of one layer or two or more layers. The thickness of the coating film is not particularly limited and can be appropriately set according to the use purpose of the coated metal material.

[0100] Examples

[0101] Hereinafter, the effects of the present invention will be described in detail by way of examples, but the present invention is not limited to the following examples.

[0102] <Metal material>

[0103] As the metal materials, cold-rolled mild steel sheets (SPCC: thickness 0.8 mm) conforming to the provisions of JIS G3141:2011, alloyed hot-dip galvanized steel sheets (GA: thickness 0.8 mm) conforming to the provisions of JIS G3302:2012, aluminum alloy sheets (A6061: thickness 0.8 mm) conforming to the provisions of JIS H4000:2014, hot-dip galvanized steel sheets (SGCC: thickness 0.8 mm) conforming to the provisions of JIS G3302:2012, magnesium alloy sheets (MP-AZ31B: thickness 0.8 mm) conforming to the provisions of JIS H4201:2018, and hot-dip galvanized aluminum magnesium-based (ZM40 / 40: thickness 0.8 mm) were each cut into a size of 70 mm in length × 150 mm in width.

[0104] <Each component used in the preparation of the chemical conversion treatment agent>

[0105] In the preparation of the chemical conversion treatment agent, the following raw materials were used.

[0106] (Supply source A)

[0107] A1: Hexafluorozirconic acid

[0108] A2: Zirconium nitrate

[0109] A3: Zirconium hydroxide

[0110] (Supply source B)

[0111] B1: Aluminum nitrate

[0112] B2: Aluminum hydroxide

[0113] (Polymer C)

[0114] C1: Diallylamine polymer (PAS-21; Nittobo-Medical Co., Ltd., content ratio of formula (i) 100%)

[0115] C2: Diallylamine hydrochloride polymer (PAS-21CL; Nittobo-Medical Co., Ltd., content ratio of formula (i) 100%)

[0116] C3: Allylamine hydrochloride - diallylamine hydrochloride polymer (PAA-D11-HCL: Nittobo-Medical Co., Ltd., content ratio of formula (i) 50%)

[0117] In addition, hydrofluoric acid is used as the supply source of fluoride ions.

[0118] In addition, the following raw materials are used as other additives.

[0119] (Organic acid)

[0120] D1: Methanesulfonic acid

[0121] D2: Ethanesulfonic acid

[0122] D3: Succinic acid

[0123] D4: Citric acid

[0124] (Oxidizer E)

[0125] E1: Nitric acid

[0126] (Metal F other than supply sources A and B)

[0127] F1: Ferrous sulfate

[0128] F2: Iron(III) nitrate

[0129] F3: Copper nitrate

[0130] (Organosilane compound G)

[0131] G1: 3-Aminopropyldimethylmethoxysilane

[0132] G2: 3-Aminopropylmethyldimethoxysilane

[0133] G3: 3-Aminopropyldiethylethoxysilane

[0134] G4: 3-Aminopropyl ethyldiethoxysilane

[0135] G5: 3-Aminopropyltriethoxysilane

[0136] G6: 3-Aminopropyltrimethoxysilane

[0137] G7: 3-Glycidoxypropyltrimethoxysilane

[0138] G8: Ethyltrimethoxysilane

[0139] G9: Ureidopropyltriethoxysilane

[0140] G10: Isocyanatopropyltriethoxysilane

[0141] (Metal alkoxide H)

[0142] H1: Titanium methoxide

[0143] H2: Vanadium propoxide

[0144] H3: Tetra-n-propoxyzirconium

[0145] H4: Aluminum isopropoxide

[0146] H5: Vinyltrimethoxysilane

[0147] (Other components)

[0148] I1: Hydroxylamine sulfate

[0149] I2: Ascorbic acid

[0150] <Preparation of chemical conversion treatment agent>

[0151] As shown in Tables 1 to 2, the chemical conversion treatment agents of Examples 1 to 48 and Comparative Examples 1 to 24 were prepared by mixing the respective components in the specified amounts and then adjusting the pH to the specified value with sodium hydroxide.

[0152] <Manufacture of metal material with chemical conversion film>

[0153] The surfaces of various metal materials were degreased by spraying a degreasing agent (FC-E2093; manufactured by Parkerizing Co., Ltd., Japan; an aqueous solution dissolved in water to a concentration of 13 g / L of Agent A and 11 g / L of Agent B) at 43°C for 120 seconds. Subsequently, spray water washing was performed at 25°C for 30 seconds. Then, the metal materials that had been spray water washed after degreasing were immersed in various chemical conversion treatment agents (chemical conversion treatment agents of Examples 1 to 48 and Comparative Examples 1 to 24) at 15°C (low temperature) or 38°C (high temperature) for 120 seconds to form a chemical conversion film on the surfaces of the metal materials. The surfaces of the obtained metal materials with chemical conversion films were successively washed with tap water and deionized water at 25°C. After water washing, the test pieces for appearance evaluation were dried at 40°C for 10 minutes. The test pieces for corrosion resistance after painting were not dried and were used for the painting described below.

[0154] [Table 1]

[0155] Table 1

[0156]

[0157] [Table 2]

[0158] Table 2

[0159]

[0160] <Determination of the amount of zirconium element (Zr adhesion amount) in the chemical conversion film>

[0161] The amount of zirconium element in the chemical conversion film formed on the surface of the metal material was determined as the Zr adhesion amount using fluorescent X-rays (scanning type fluorescent X-ray analyzer ZSX primusII manufactured by Rigaku Corporation).

[0162] <Manufacture of metal materials with coating films>

[0163] After painting on the chemical conversion films formed on the surfaces of various metal materials, sintering was performed to produce metal materials with coating films. The following shows the detailed content of the painting method and the sintering conditions.

[0164] (Cationic electrodeposition painting)

[0165] A metal material with various chemical conversion films was used as the cathode, and electrolysis was carried out using a cationic electrodeposition coating (GT-100V; manufactured by Kansai Paint Co., Ltd.) to form a coating film. In addition, the electrolysis was carried out at an applied voltage of 180 V and a temperature of 30.0 ± 0.5 °C. Furthermore, the electrolysis was carried out by adjusting the amount of electricity so that the coating film thickness became 15.0 ± 1.0 μm. After cationic electrodeposition, the surface of the coating film was washed with deionized water and sintered at 170 °C for 26 minutes to produce a metal material with a coating film (each test piece).

[0166] <Chemical conversion appearance>

[0167] The film appearance of the test pieces with chemical conversion films obtained from each example and comparative example was visually determined.

[0168] <Evaluation criteria>

[0169] A: There is no unevenness in the flat part and the edge when observing the test piece from the front, and there is no unevenness in the flat part and the edge when observing the test piece at an inclination of 20° from the front

[0170] B: There is no unevenness in the flat part and the edge when observing the test piece from the front, and there is unevenness in the flat part and the edge when observing the test piece at an inclination of 20° from the front

[0171] C: There is no unevenness in the flat part when observing the test piece from the front, there is unevenness in the edge, and there is unevenness in the flat part and the edge when observing the test piece at an inclination of 20° from the front

[0172] D: There is unevenness in the flat part and the edge when observing the test piece from the front, and there is unevenness in the flat part and the edge when observing the test piece at an inclination of 20° from the front

[0173] <Corrosion resistance test (exposure test)>

[0174] Using a cutter, a cross-shaped scar (cross-cut) reaching the metal substrate was made on the coating film surface of various test pieces with a coating film. The test pieces were exposed near the sea in Okinawa for two years, and then the coating film swelling width (maximum unilateral swelling width) starting from the scar part (cross-cut part) of the test piece was measured. The corrosion resistance was evaluated according to the following evaluation criteria.

[0175] <Evaluation criteria - cross-cut part>

[0176] A: The unilateral swelling width is less than 5.0 mm

[0177] B: The unilateral swelling width is 5.0 mm or more and less than 10.0 mm

[0178] C: The unilateral swelling width is 10.0 mm or more and less than 15.0 mm

[0179] D: The unilateral swelling width is 15.0 mm or more

[0180] <Corrosion Resistance Test (VDA)>

[0181] Using a cutting knife, make a scratch reaching the metal substrate in the center of the coated surface of various test pieces with a coating film, and conduct a corrosion cycle test based on VDA Test 621-415 and DIN EN ISO 20567-1 (1982 edition; Method C) for 6 cycles.

[0182] Measure the swelling width of the coating film (the maximum unilateral swelling width) starting from the scratched part (cut part) of the test piece. Evaluate the corrosion resistance according to the following evaluation criteria.

[0183] <Evaluation Criteria - Cut Part>

[0184] A: The unilateral swelling width is less than 5.0 mm

[0185] B: The unilateral swelling width is 5.0 mm or more and less than 10.0 mm

[0186] C: The unilateral swelling width is 10.0 mm or more and less than 15.0 mm

[0187] D: The unilateral swelling width is 15.0 mm or more

[0188] The results of each evaluation test are shown in Tables 3 to 6. In addition, in all evaluations, B or above is set as the passing level.

[0189] [Table 3]

[0190] Table 3

[0191]

[0192] [Table 4]

[0193] Table 4

[0194]

[0195] [Table 5]

[0196] Table 5

[0197]

[0198] [Table 6]

[0199] Table 6

[0200]

[0201] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A chemical conversion treatment agent that forms a chemical conversion film on the surface or on the surface of a metal material. The chemical conversion treatment agent satisfies the following formula (1) and is formulated with: A supply source of fluoride ions; A supply source A of ions containing zirconium; A supply source B of ions containing aluminum; and A water-soluble or water-dispersible polymer or its salt C, which contains structural units represented by the following formula (i) in a molar conversion of 90% or more. (Ac + Bc) × (pH - 3)x ≥ 0.38... Formula (1) Among them, X＝7.2×12 (-1.6×(Ac+Bc)) ， Here, in the formula (1), Ac is the zirconium element concentration from the supply source A in the chemical conversion treatment agent, and the Ac is 0.02 g / L or more and 2 g / L or less. Bc is the aluminum element concentration from the supply source B in the chemical conversion treatment agent, and the Bc is 0.02 g / L or more and 2 g / L or less. The ratio Bc / Ac of Bc to Ac is 0.03 or more and 10.0 or less. The concentration of the polymer or its salt C in the chemical conversion treatment agent is 0.0001 g / L or more and (0.16 × Ac + 0.23) g / L or less. pH is the pH of the chemical conversion treatment agent, and the pH is 3.8 or more and 6.0 or less.

2. The chemical conversion treatment agent according to claim 1, wherein The metal material is at least one or more of an iron material, a galvanized material or a galvanized-based material, an aluminum material, an aluminum alloy material, an aluminized-based material, a magnesium material, and a magnesium alloy material.

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