Method for producing metal material with chemical conversion coating film

Abstract

The purpose of the present invention is to provide a method for producing a metal material with a chemical conversion coating film, said metal material having a chemical conversion coating film formed thereon, said chemical conversion coating film having excellent appearance after a chemical conversion treatment and excellent corrosion resistance as evaluated by an exposure test, VDA621-415 method or the like after coating, and being usable over a wide temperature range. The problem is solved by a method for producing a metal material with a chemical conversion coating film, in which a chemical conversion coating film is formed on the surface or on the surface of a metal material. The method includes a step I in which the metal material is brought into contact with a chemical conversion treatment agent and a step II in which the metal material after being brought into contact with the chemical conversion treatment agent is brought into contact at least once with an aqueous solution having a pH of 4.0-12.0. The chemical conversion treatment agent comprises a supply source of fluorine ions, a supply source A containing zirconium ions, a supply source B containing aluminum ions, and 0.0001 g / L to 1.000 g / L inclusive of a water-soluble or water-dispersible polymer having a structural unit represented by formula (i) in an amount of 90% or more in terms of mole, or a salt C thereof. The value obtained by subtracting the value obtained by formula (2) from the value obtained by formula (1) is 0.2 or more. Formula (1): (Ac + Bc) * (pH-2. 7) 8. Formula (2): (D / 0.18) 3 * (t / 1.5) 5. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a metal material with a chemical conversion film formed on the surface or on the surface of a metal material, the metal material with a chemical conversion film. Background Art

[0002] Conventionally, a treatment liquid for metal surface treatment has been developed, which can perform surface treatment with excellent corrosion resistance and good adhesion. 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, a sufficient amount of a fluorine-containing compound, metal ion B, metal ion C, and nitrate ions. The above Compound A contains at least one metal element selected from Hf(IV), Ti(IV), and Zr(IV). The above sufficient amount of the fluorine-containing compound makes the fluorine in the composition present at least 5 times the molar concentration of the total molar concentration of the metals contained in the above Compound A. The above metal ion B is at least one selected from alkaline earth metals, and the above metal ion C is at least one selected from Al, Zn, Mg, Mn, and Cu.

[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 surface treatment, in addition to attaching importance to adhesion and corrosion resistance, appearance is also emphasized as the finish of processing. Regarding the finish of processing, if the liquid adhesion amount of the chemical conversion treatment agent is excessive or the adhesion time is too long between the contact process of the chemical conversion treatment agent and the next process, appearance unevenness will occur, or the corrosion resistance performance will be affected. It is necessary to stipulate the optimal compounding conditions of the chemical conversion treatment agent, the liquid adhesion amount of the chemical conversion treatment agent, and the adhesion time for showing sufficient performance. In addition, in the corrosion resistance test, compared with the usual salt spray test (SST), JASO-M609 method, etc., in recent years, exposure tests and corrosion tests closer to actual environmental conditions have been more emphasized. Furthermore, in recent years, from the viewpoint of reducing the environmental load, lowering the chemical conversion treatment temperature has also been emphasized.

[0008] An object of the present invention is to provide a method for manufacturing a metal material with a chemical conversion film, the metal material with a chemical conversion film having a chemical conversion film formed thereon, the chemical conversion film having excellent appearance after chemical conversion treatment and excellent corrosion resistance evaluated by exposure tests, VDA621-415 method, etc. after painting and being capable of being used in a wide temperature range.

[0009] Solution for solving problems

[0010] In order to solve the above problems, the present inventors conducted intensive studies repeatedly and found that by manufacturing a metal material with a chemical conversion film under conditions satisfying specified parameters, the above manufacturing method includes: a step of bringing the metal material into contact with a chemical conversion treatment agent, the chemical conversion treatment agent being 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 specific water-soluble or water-dispersible polymer or its salt C; and a step of bringing the metal material into contact with an aqueous solution having a pH of 4 to 12 at least once, it is possible to manufacture a chemical conversion film having excellent corrosion resistance and appearance after chemical conversion treatment, thus completing the present invention.

[0011] The present invention includes the following contents and the like.

[0012] [1] A method for manufacturing a metal material with a chemical conversion film, the chemical conversion film being formed on the surface or surfaces of the metal material,

[0013] The above manufacturing method includes:

[0014] Step I of bringing the metal material into contact with a chemical conversion treatment agent; and

[0015] Step II of bringing the metal material that has been in contact with the chemical conversion treatment agent into contact with an aqueous solution having a pH of 4.0 or more and 12.0 or less at least once,

[0016] The above chemical conversion treatment agent is formulated with:

[0017] A supply source of fluoride ions;

[0018] A supply source A of ions containing zirconium;

[0019] A supply source B of ions containing aluminum; and

[0020] A water-soluble or water-dispersible polymer or its salt C having a structural unit represented by the following formula (i) in a molar conversion of 90% or more and in an amount of 0.0001 g / L or more and 1.000 g / L or less,

[0021] [Chemical formula 1]

[0022]

[0023] The value obtained by subtracting the value obtained from the following formula (2) from the value obtained from the following formula (1) is 0.2 or more.

[0024] (Ac + Bc) × (pH - 2.7) 8 …Formula (1)

[0025] (D / 0.18) 3 ×(t / 1.5) 5 …Formula (2)

[0026] Here, in the above formula (1), Ac is the concentration of zirconium element from the above supply source A in the above chemical conversion treatment agent, and is 2 g / L or less,

[0027] Bc is the concentration of aluminum element from the above supply source B in the above chemical conversion treatment agent, and is 2 g / L or less,

[0028] The ratio Bc / Ac of Bc to Ac is 0.03 or more and 10.0 or less,

[0029] pH is the pH of the above chemical conversion treatment agent, and is 3.2 or more and 6.0 or less,

[0030] In the above formula (2), D is the liquid adhesion amount of the above chemical conversion treatment agent adhered to the surface of the above metal material between Process I and Process II, and is greater than 0 L / m 2 and is 0.5 L / m 2 or less,

[0031] t is the time from the end of the above Process I to the start of Process II, and is 0.01 minute or more and 3.00 minutes or less.

[0032] [2] The manufacturing method of the metal material with a chemical conversion film according to [1], wherein,

[0033] Before the above Process I, it includes:

[0034] Process III of contacting with an alkaline solution having a pH of 8.0 or more and 13.0 or less; and

[0035] Process IV of contacting with an aqueous solution having a pH of 7.0 or more and 12.0 or less.

[0036] [3] The manufacturing method of the metal material with a chemical conversion film according to [1] or [2], wherein the above metal material is at least one of an iron material, a galvanized material or a galvanized system material, an aluminum material, an aluminum alloy material, an aluminized system material, a magnesium material, and a magnesium alloy material.

[0037] Advantages of the Invention

[0038] According to the present invention, a method for manufacturing a metal material with a chemical conversion film can be provided. In the metal material with a chemical conversion film, a chemical conversion film is formed on the surface or surfaces of the metal material. The chemical conversion film has excellent corrosion resistance evaluated by exposure tests, the VDA621-415 method, etc. after painting and can be used in a wide temperature range. Detailed Embodiments

[0039] In this specification, a numerical range expressed using "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. "A~B" means A or more and B or less.

[0040] Hereinafter, a method for manufacturing a metal material with a chemical conversion film according to an embodiment of the present invention will be described.

[0041] (Chemical Conversion Treatment Agent)

[0042] The chemical conversion treatment agent used in this embodiment is prepared by mixing a supply source of fluoride ions, a supply source A of zirconium-containing ions, a supply source B of aluminum-containing ions, 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, a chemical conversion film with excellent corrosion resistance after painting and film appearance can be formed on the metal material. In addition, the chemical conversion treatment agent used in this embodiment may be a chemical conversion treatment agent that contains only a supply source of fluoride ions, 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 contains other components.

[0043] (Supply Source of Fluoride Ions)

[0044] The chemical conversion treatment agent used in this embodiment is mixed 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 mixed 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, hexafluorozirconic acid, hexafluorotitanic acid, hexafluoro Hafnium acid, 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 hexafluorozirconic acid can supply both zirconium-containing ions and fluoride ions. In addition, various fluorine-containing compounds can be mixed with only one kind, or two or more kinds can be mixed. The mixing amount of the fluorine-containing compound is not particularly limited, and it is preferably set to a level that does not affect the formation of the chemical conversion film. Specifically, it is preferably mixed 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 mixing 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.

[0045] (Supply source A)

[0046] The chemical conversion treatment agent used in this embodiment is mixed 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 mixed with the chemical conversion treatment agent. Therefore, the chemical conversion treatment agent used in this embodiment contains zirconium-containing ions. Examples of zirconium-containing ions include, for example: metal ions of zirconium; complex ions containing zirconium; oxide ions of zirconium, etc.

[0047] Specific examples of supply source A as a supply source of zirconium-containing ions include hexafluorozirconic acid, zirconium nitrate, zirconyl nitrate, zirconium carbonate, zirconium hydroxide, zirconium oxide, etc. In addition, when these substances can be in the form of salts, they can also be their salts. These supply sources can be mixed with only one kind, or two or more kinds can be mixed.

[0048] 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. In addition, it is usually 2 g / L or less, preferably 1.5 g / L or less. When two or more supply sources are mixed in the chemical conversion treatment agent, it refers to the total concentration of zirconium element contained in them.

[0049] By making the zirconium element concentration Ac within the above range, Zr in the chemical conversion film can be made an effective amount.

[0050] (Supply source B)

[0051] The chemical conversion treatment agent used in this embodiment contains 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 incorporated into the chemical conversion treatment agent. Therefore, the chemical conversion treatment agent used in this embodiment contains aluminum-containing ions. Examples of 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 aluminum-containing ions include aluminum hydroxide, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum oxide, etc., but are not limited to these. In addition, when these substances can take the form of salts, they can also be their salts. These supply sources can be incorporated singly or in combination of two or more.

[0052] 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, and in addition, usually 2 g / L or less, preferably 1.5 g / L or less. When two or more supply sources B are incorporated into the chemical conversion treatment agent, it refers to the total concentration of aluminum element from them.

[0053] 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.

[0054] (Ratio of supply source A to B)

[0055] 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.

[0056] (Water-soluble or water-dispersible polymer or its salt C)

[0057] The chemical conversion treatment agent used in 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, diallylamine acetate polymers, etc., i.e., polydiallylamines.

[0058] 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 equivalent.

[0059] 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, as a solid component mass concentration. In addition, it is usually 1.000 g / L or less, preferably (0.16×Ac + 0.23) g / L or less. By making the content of polymer C within the above range, the adhesion and corrosion resistance of the chemical conversion film will be improved.

[0060] (aqueous medium)

[0061] The chemical conversion treatment agent used in this 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, there is no particular limitation as long as it is miscible with water, 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 singly or in combination of two or more.

[0062] (Other components)

[0063] In the range that does not hinder the effects of the present invention, other additives can also be incorporated into the chemical conversion treatment agent used in this embodiment. Specifically, for example, organic acids, oxidants, supply sources of 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. can be cited. In addition, these other components can be incorporated singly or in combination of two or more.

[0064] (Organic acid)

[0065] As the organic acids that can be contained in the chemical conversion treatment agent used in this embodiment, for example, organic sulfonic acids, organic phosphonic acids, organic phosphoric acids, aliphatic carboxylic acids, and aromatic carboxylic acids, etc. Specifically, methanesulfonic acid, ethanesulfonic acid, lactic acid, oxalic acid, citric acid, etc., but not limited to these. The organic acids can contain only one kind or two or more kinds.

[0066] (Oxidant)

[0067] Examples of the oxidizing agents that can be incorporated into the chemical conversion treatment agent used in the present embodiment include, for example, hydrogen peroxide, nitrates, nitrites, permanganates, chlorates, persulfates, nitro-containing compounds, hypochlorous acid, organic peroxides, and bromates, etc. Hydrogen peroxide, nitrates, and nitrites are preferred, but not limited to these. Only one type of oxidizing agent can be incorporated, or two or more types can be incorporated. In addition, sulfate ions may or may not be included.

[0068] (Sources of metal ions other than sources A and B)

[0069] Examples of the sources of metal ions other than sources A and B that can be incorporated into the chemical conversion treatment agent used in the present embodiment include, for example, compounds containing copper, iron, manganese, magnesium, nickel, cobalt, zinc, tungsten, etc., but not limited to these. Only one type of source of metal ions other than sources A and B can be incorporated, or two or more types can be incorporated.

[0070] (Organosilane compound)

[0071] The organosilane compounds that can be incorporated into the chemical conversion treatment agent used in the present embodiment are, for example, aminosilane compounds, epoxy group-containing 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-glycidoxypropyldiethylethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. are included, 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 after hydrolysis of the organosilane compound, or in the form of a condensate after polycondensation of the hydrolyzate, or in the form of a copolymer (alternating copolymer, random copolymer, block copolymer, graft copolymer, etc.) after copolymerization of the respective hydrolyzates, or multiple forms can coexist in a mixed state.

[0072] (Metal alkoxides)

[0073] Examples of the metal alkoxides that can be incorporated in the chemical conversion treatment agent used in this embodiment include, but are not limited to, zirconium tetrapropoxide, zirconium tetraisopropoxide, zirconium tetra-n-propoxide, zirconium tetra-n-butoxide, titanium methoxide, titanium ethoxide, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium butoxide dimer, titanium tetra-2-ethylhexoxide, vanadium(V) triisopropoxide, vanadium butoxide, vanadium(V) triethoxide, 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 alkoxides in the chemical conversion treatment agent can be in their original form, or in the form of hydrolyzates of the metal alkoxides, or in the form of polycondensates of the hydrolyzates or hydrolyzates of organosilane compounds, or in the form of copolymers (alternating copolymers, random copolymers, block copolymers, graft copolymers, etc.) obtained by copolymerizing the respective hydrolyzates or hydrolyzates of organosilane compounds, or multiple forms can coexist in a mixed state.

[0074] The metal alkoxide containing zirconium can also be regarded as supply source A, and the metal alkoxide containing aluminum can also be regarded as supply source B.

[0075] (Water-soluble resin or water-dispersible resin other than polymer C)

[0076] Examples of the water-soluble resin or water-dispersible resin other than polymer C that can be incorporated in the chemical conversion treatment agent used in this embodiment include, but are not limited to, poly(meth)acrylic resin, polyurethane resin, acrylic resin, epoxy resin, phenolic resin, amine resin that does 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.

[0077] (Surfactant)

[0078] Examples of the surfactant that can be incorporated in the chemical conversion treatment agent used in the present embodiment include: nonionic surfactants; ionic surfactants such as cationic, anionic, or amphoteric surfactants. As the nonionic surfactant, there is no particular limitation, and examples include polyglycol-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. As the cationic surfactant, there is no particular limitation, and examples 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. As the anionic surfactant, there is no particular limitation, and examples include higher alkyl ether sulfates added with ethylene oxide, etc. In addition, the HLB value (calculated by the Griffin method) of the above surfactant is not particularly limited, preferably 6 or more and 18 or less, more preferably 10 or more and 14 or less. The above surfactant can be incorporated alone or in combination of two or more in the chemical conversion treatment agent used in the present embodiment. By including the above surfactant in the chemical conversion treatment agent, chemical conversion treatment and degreasing treatment can be carried out simultaneously in one step.

[0079] (pH of the chemical conversion treatment agent)

[0080] The pH of the chemical conversion treatment agent used in the present embodiment is generally in the acidic to neutral range. Specifically, the pH is in the range of 3.2 to 6.0, more preferably in the range of 3.4 to 6.0, and particularly preferably in the range of 4.1 to 5.1. Here, the pH value in this specification refers to the value measured at 40 °C using a pH meter.

[0081] 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; and 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 is not limited to these components. In addition, one or more pH regulators can be used.

[0082] (Method for manufacturing the chemical conversion treatment agent)

[0083] The above chemical conversion treatment agent can be manufactured by incorporating a supply source of fluoride ions, supply source A, supply source B, and a specified polymer or its salt C as raw materials in a specified amount in an aqueous medium.

[0084] (Method for forming the chemical conversion film)

[0085] The manufacturing method of the metal material with a chemical conversion film formed on the surface or on the surface of the metal material in this embodiment includes step I of bringing the above chemical conversion treatment agent into contact with the surface or on the surface of the metal material. Thereby, a chemical conversion film is formed on the surface or on the surface of the metal material. As the method of bringing the chemical conversion treatment agent into contact with the metal material, existing contact methods can be cited, such as immersion treatment method, spray treatment method, flow coating treatment method and other treatment methods or combinations thereof, but it is not limited to these.

[0086] The contact temperature in the above contact step 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 this embodiment, the range of 10°C or higher and 25°C or lower is regarded as "low temperature", and the range greater than 25°C and 50°C or lower is regarded as "high temperature". In addition, 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 it is not limited to these times.

[0087] In the manufacturing method of the metal material with a chemical conversion film in this embodiment, after step I of bringing the metal material into contact with the chemical conversion treatment agent, it includes step II of bringing the metal material that has come into contact with the above chemical conversion treatment agent into contact with an aqueous solution having a pH of 4.0 or higher and 12.0 or lower. The contact of the aqueous solution in step II is carried out by, for example, immersion treatment method, spray treatment method, etc., but it is not limited to these. The pH of the aqueous solution in step II is in the range of 4.0 to 12.0, preferably in the range of 5.0 to 10.0, and particularly preferably in the range of 6.5 to 9.0. The aqueous solution in step II is not particularly limited as long as it is within the above pH range. Exemplarily, tap water, deionized water, sodium hydroxide aqueous solution, etc. can be cited. The contact in step II only needs to be carried out at least once, and it can also be carried out multiple times. In addition, after step II is carried out, a drying step of drying the surface of the metal material can also be carried out.

[0088] (Liquid adhesion amount D)

[0089] In the method for manufacturing a metal material with a chemical conversion film according to this embodiment, the liquid adhesion amount D is the liquid adhesion amount of the chemical conversion treatment agent adhered to the surface of the metal material between Process I and Process II. When the contact method in Process I is the dipping method, it refers to the adhesion amount per unit area of the chemical conversion treatment agent remaining on the surface of the metal material at the moment when the metal material is lifted from the chemical conversion treatment bath and no longer in contact with the liquid surface. In addition, when the contact method in Process I is spray treatment or flow coating treatment, it refers to the adhesion amount per unit area of the chemical conversion treatment agent remaining on the surface of the metal material at the moment when the spraying or flow coating of the chemical conversion treatment agent on the metal material is stopped. The liquid adhesion amount D is greater than 0 L / m 2 and is 0.5 L / m 2 Hereinafter, it is preferably 0.4 L / m 2 or less.

[0090] (Time t from Process I to Process II)

[0091] In the method for manufacturing a metal material with a chemical conversion film according to this embodiment, the time from the end of Process I to the start of Process II is set as t. Regarding the end moment of Process I, when the contact method in Process I is the dipping method, it refers to the moment when the metal material is lifted from the chemical conversion treatment bath and no longer in contact with the liquid surface. When the contact method in Process I is spray treatment or flow coating treatment, it refers to the moment when the spraying or flow coating of the chemical conversion treatment agent on the metal material is stopped. The start moment of Process II is the moment when the metal material comes into contact with the aqueous solution of Process II. t is preferably 0.01 minute or more and 3.00 minutes or less, more preferably 0.08 minute or more and 2.00 minutes or less, and particularly preferably 0.1 minute or more and 1.5 minutes or less.

[0092] (Value of specific parameter)

[0093] In the method for manufacturing a metal material with a chemical conversion film according to this embodiment, the value derived from Formula (1) related to the properties of the chemical conversion treatment agent and the value derived from Formula (2) related to the liquid adhesion amount and residence time of the chemical conversion treatment agent have a specified relationality. Specifically, the value obtained by subtracting Formula (2) from Formula (1) is usually 0.2 or more and 5000 or less, preferably 0.5 or more and 2000 or less, and further preferably 2.5 or more and 1000 or less. By making the value obtained by subtracting Formula (2) from Formula (1) within the above range, a chemical conversion film that not only has excellent corrosion resistance after coating but also has excellent appearance after chemical conversion treatment can be formed on the surface or on the surface of the metal material.

[0094] In addition, before the step I of contacting with the chemical conversion treatment agent, it may further include a step III of contacting with an alkaline solution having a pH of 8.0 or more and 13.0 or less, and a step IV of contacting with an aqueous solution having a pH of 7.0 or more and 12.0 or less. By performing the step III and the step IV in this way, it is possible to remove oil and dirt adhering to the surface of the metal material. The alkaline solution in the step III is not particularly limited as long as it is an alkaline solution having a pH of 8.0 or more and 13.0 or less. Exemplarily, an alkaline solution containing a degreasing agent can be cited. In addition, the aqueous solution in the step IV is not particularly limited as long as it is an aqueous solution having a pH of 7.0 or more and 12.0 or less. Exemplarily, an aqueous sodium hydroxide solution can be cited.

[0095] In addition, in the method for manufacturing a metal material with a chemical conversion film of the present embodiment, before the step I of contacting with the chemical conversion treatment agent, in addition to the step III and the step IV, a pretreatment step may also be performed. As the pretreatment step, for example, a pickling step; a degreasing step; an alkali washing step; a chromate chemical conversion treatment step; a phosphate chemical conversion treatment step using phosphates such as zinc phosphate and iron phosphate; a bismuth replacement plating step, a zirconium chemical conversion treatment step, a titanium chemical conversion treatment step, a hafnium chemical conversion treatment step, a vanadium chemical conversion treatment step, etc. can be cited. In addition, these pretreatment steps may be performed in one step, or two or more steps may be combined and performed in sequence. As a combination of two or more steps, for example, a combination of a phosphate chemical conversion treatment step and a chromate chemical conversion treatment step, a bismuth replacement plating step, a zirconium chemical conversion treatment step, a titanium chemical conversion treatment step, a hafnium chemical conversion treatment step, or a vanadium chemical conversion treatment step can be cited. The zirconium chemical conversion treatment step implemented as the pretreatment step may use the above chemical conversion treatment agent, or may use a chemical conversion treatment agent different from the above chemical conversion treatment agent. In addition, in the case of performing the above various pretreatment steps, a water washing treatment step may also be performed after each of the various pretreatment steps. In the case of performing a plurality of various pretreatment steps, a water washing treatment step may also be performed after each step or after some steps. In addition, in the case of performing a water washing treatment step, a drying step of drying the surface of the metal material may also be performed after that.

[0096] The order of the step III and the step IV and the pretreatment step is not particularly limited. The pretreatment step may be performed before the step III and the step IV, or may be performed after the step III and the step IV. In addition, in the case of performing two or more pretreatment steps, the pretreatment step may also be performed before and after the step III and the step IV.

[0097] In addition, in the method for manufacturing a metal material with a chemical conversion film according to this embodiment, 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 replacement plating process, a ferrophosphorus 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 after the contact process II. 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 a post-treatment process can use the above chemical conversion treatment agent, or a chemical conversion treatment agent different from the above chemical conversion treatment agent. In addition, in the case of performing the above various post-treatment processes, a water washing treatment process can also be performed after the various post-treatment processes. In the case of performing multiple various post-treatment processes, a water washing treatment process can also be performed after each process or some processes. Furthermore, in the case of performing a water washing treatment process, a drying process for drying the surface of the metal material can also be performed after that.

[0098] In addition, a coating film can also be formed on the chemical conversion film formed by the method for manufacturing a metal material with a chemical conversion film according to this embodiment to manufacture a coated metal material having a chemical conversion film and a coating film. In this case, after forming the chemical conversion film, a coating film forming treatment for forming a coating film can be implemented, and the coating film forming treatment is a coating process and a drying process (which can include a baking process, a curing process, etc.) for drying the coating on the surface of the coated metal material.

[0099] In addition, a drying process for drying the surface of the metal material after the water washing treatment process II can also be performed. Furthermore, one or two or more of the above post-treatment processes can be performed after the above process II and before the coating process. In addition, in the case of performing the above various post-treatment processes, a water washing treatment process can also be performed after the various post-treatment processes. In the case of performing multiple various post-treatment processes, a water washing treatment process can also be performed after each process or some processes. Furthermore, in the case of performing a water washing treatment process, a drying process for drying the surface of the metal material can also be performed after that.

[0100] The above coating process is performed on the surface of the metal material with a chemical conversion film using a coating material. The coating method is not particularly limited, and conventional well-known methods can be applied, such as rolling coating, electrodeposition coating (such as cationic electrodeposition coating, anionic electrodeposition coating, etc.), spraying, thermal spraying, airless spraying, electrostatic (powder) coating, roll coating, curtain flow coating, brush coating, bar coating, flow dipping method, etc.

[0101] Examples of such coatings include well-known coatings such as oil-based coatings, cellulose derivative coatings, phenolic resin coatings, alkyd resin coatings, amino alkyd resin coatings, urea-formaldehyde resin coatings, unsaturated resin coatings, vinyl resin coatings, acrylic resin coatings, epoxy resin coatings, polyurethane resin coatings, silicone resin coatings, fluororesin coatings, rust-preventive coatings, antifouling coatings, powder coatings, cationic electrodeposition coatings, anionic electrodeposition coatings, water-based coatings, and solvent coatings. In addition, for the coating process, one coating can be performed using various coatings that are the same or different, or two or more coatings can be performed. Further, the drying process is a treatment for drying the coated paint to cure it. Examples of drying methods include natural drying, vacuum drying, convective heat drying (e.g., natural convection heat drying, forced convection heat drying), radiative drying (e.g., near-infrared drying, far-infrared drying), ultraviolet curing drying, electron beam curing drying, vapor cure, baking drying, etc. Additionally, one of these drying methods can be implemented, or two or more can be combined and implemented.

[0102] For the above-mentioned cationic electrodeposition coating, well-known methods can be applied. Examples include the following methods: As the coating, a cationic electrodeposition coating containing an amine-added epoxy resin and a blocked polyisocyanate curing agent as the curing component is used, and a metal material with a chemical conversion film is immersed in this coating. Cationic electrodeposition coating is carried out, for example, by applying a voltage with a rectifier using the metal material with a chemical conversion film as the cathode while maintaining the temperature of the coating at a specified temperature and stirring the coating. By performing water washing and baking on the above-mentioned metal material after cationic electrodeposition coating in this way, a coating film can be formed on the chemical conversion film. Baking is carried out for a certain time within a specified temperature range. For example, it can be carried out in the manner of 20 minutes at 170 °C. In addition, when 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 use water with a sodium ion concentration of less than 500 ppm based on mass to perform the above-mentioned water washing treatment process before the coating process.

[0103] For coating methods such as spraying using powder coatings, electrostatic powder coating, and flow dipping method, well-known methods can be applied. Examples of powder coatings include powder coatings containing a polyester resin and a blocked isocyanate curing agent, a β-hydroxyalkylamide curing agent (e.g., refer to Japanese Patent Laid-Open No. 2011-88083), or triglycidyl isocyanurate. Baking is carried out for a certain time within a specified temperature range. For example, it can be carried out in the manner of 20 minutes at 130 °C to 250 °C.

[0104] As coating methods such as spraying, electrostatic coating, and rod coating using the above solvent coatings, known methods can be applied. As solvent coatings, for example, solvent coatings containing resins such as melamine resin, acrylic resin, polyurethane resin, and polyester resin, and organic solvents such as diluents can be cited. Baking is carried out for a certain time within a specified temperature range. For example, it can be carried out at 130 °C for 20 minutes.

[0105] As drying methods for curing the coated paint, for example, natural drying, vacuum drying, convective heat drying (such as natural convective heat drying, forced convective heat drying), radiation drying (such as near-infrared drying, far-infrared drying), ultraviolet curing drying, electron beam curing drying, gas phase curing, etc. can be cited. These drying methods can be implemented singly, or two or more of them can be implemented in combination.

[0106] The coating film obtained through the coating process can be single-layer or multi-layer. In the case of 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.

[0107] As metal materials, for example: iron (such as cold-rolled steel sheet, hot-rolled steel sheet, high-tensile steel sheet, tool steel, alloy tool steel, spheroidal graphite cast iron, gray cast iron, etc.); plating materials, such as galvanized materials and galvanized-based materials (such as 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 (such as 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 (such as AZ91, AZ61, AZ31, etc.).

[0108] Regarding the chemical conversion film formed by the manufacturing method of the metal material with a chemical conversion film of the present embodiment, the mass of zirconium contained in the chemical conversion film is preferably 5 mg / m per unit area 2 or more, more preferably 10 mg / m 2 or more, and further preferably 20 mg / m 2 or more. As the upper limit value, there is no particular limitation, and it is preferably 800 mg / m 2 or less. In addition, the mass of zirconium in the chemical conversion film can be measured by, for example, using a fluorescent X-ray analysis device.

[0109] The metal material with a chemical conversion film manufactured by the manufacturing method of the metal material with a chemical conversion film of the present embodiment may have one or more of the above various films (such as chromate chemical conversion film, phosphate chemical conversion film, bismuth replacement plating film, etc.) above or below the chemical conversion film obtained by bringing it into contact with the chemical conversion treatment agent of the present embodiment.

[0110] By applying a coating on the surface of the metal material having the chemical conversion film of the present embodiment to form a coating film, a coated metal material having a chemical conversion film and a coating film can be manufactured. The coated metal material may have a coating film on the surface of the metal material having the chemical conversion film of the present embodiment, or may have a coating film on the surface of one or more of the above various films (such as chromate chemical conversion film, phosphate chemical conversion film, bismuth replacement plating film, vanadium chemical conversion film, etc.) further formed on the chemical conversion film. 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.

[0111] Examples

[0112] Hereinafter, the effects of the present invention will be described in detail by way of examples, and the present invention is not limited by the following examples.

[0113] <Metal material>

[0114] As the metal materials, the following materials were respectively cut into a size of 70 mm in length × 150 mm in width and used: cold-rolled mild steel sheet (SPCC: thickness 0.8 mm) conforming to the specification of JIS G3141:2011, alloyed hot-dip galvanized steel sheet (GA: thickness 0.8 mm) conforming to the specification of JIS G3302:2012, aluminum alloy sheet (A6061: thickness 0.8 mm) conforming to the specification of JIS H4000:2014, hot-dip galvanized steel sheet (SGCC: thickness 0.8 mm) conforming to the specification of JIS G3302:2012, magnesium alloy sheet (MP-AZ31B: thickness 0.8 mm) conforming to the specification of JIS H4201:2018, and hot-dip galvanized-aluminum-magnesium system (ZM40 / 40: thickness 0.8 mm).

[0115] <Components for preparing the chemical conversion treatment agent>

[0116] In the preparation of the chemical conversion treatment agent, the following raw materials were used.

[0117] (Supply source A)

[0118] A1: Hexafluorozirconic acid

[0119] A2: Zirconium nitrate

[0120] A3: Zirconium hydroxide

[0121] (Supply source B)

[0122] B1: Aluminum nitrate

[0123] B2: Aluminum hydroxide

[0124] (Polymer C)

[0125] C1: Diallylamine polymer (PAS-21; Nittobo Medical Co., Ltd., content ratio of formula (i) 100%)

[0126] C2: Diallylamine hydrochloride polymer (PAS-21CL; Nittobo Medical Co., Ltd., content ratio of formula (i) 100%)

[0127] C3: Allylamine hydrochloride - diallylamine hydrochloride polymer (PAA-D11-HCL; Nittobo Medical Co., Ltd., content ratio of formula (i) 50%)

[0128] In addition, hydrofluoric acid is used as the supply source of fluoride ions.

[0129] Furthermore, the following raw materials are used as other additives.

[0130] (Organic acid D)

[0131] D1: Methanesulfonic acid

[0132] D2: Ethanesulfonic acid

[0133] D3: Succinic acid

[0134] D4: Citric acid

[0135] (Oxidizer E)

[0136] E1: Nitric acid

[0137] (Metal F other than supply sources A and B)

[0138] F1: Iron(III) sulfate

[0139] F2: Iron(III) nitrate

[0140] F3: Copper nitrate

[0141] (Organosilane compound G)

[0142] G1: 3-Aminopropyldimethylmethoxysilane

[0143] G2: 3-Aminopropylmethyldimethoxysilane

[0144] G3: 3 - aminopropyldiethylethoxysilane

[0145] G4: 3 - aminopropylethyldiethoxysilane

[0146] G5: 3 - aminopropyltriethoxysilane

[0147] G6: 3 - aminopropyltrimethoxysilane

[0148] G7: 3 - glycidoxypropyltrimethoxysilane

[0149] G8: ethyltrimethoxysilane

[0150] G9: ureidopropyltriethoxysilane

[0151] G10: isocyanatopropyltriethoxysilane

[0152] (Metal alkoxide H)

[0153] H1: titanium methoxide

[0154] H2: vanadium propoxide

[0155] H3: tetra - n - propoxyzirconium

[0156] H4: aluminum isopropoxide

[0157] H5: vinyltrimethoxysilane

[0158] (Other components)

[0159] I1: hydroxylamine sulfate

[0160] I2: ascorbic acid

[0161] <Preparation of chemical conversion treatment agent>

[0162] As shown in Tables 1 - 5, after mixing the specified amounts of each component, the pH was adjusted to the specified value with sodium hydroxide, thereby preparing the chemical conversion treatment agents of Examples 1 - 59 and Comparative Examples 1 - 27.

[0163] <Manufacture of metal material with chemical conversion film>

[0164] As shown in Tables 1 to 5, various metal materials are treated to produce metal materials with chemical conversion films. That is, various metal materials are immersed in a degreasing agent (FC-E2093; Japan Parkersei Co., Ltd.; dissolved in water in a manner to obtain a concentration of 13 g / L of reagent A and 11 g / L of reagent B, and adjusted to a prescribed pH with sodium hydroxide or CO2 gas) at 43°C for 120 seconds (process III). After contact with the alkaline solution, an aqueous solution adjusted to a prescribed pH with sodium hydroxide is sprayed at 25°C for 30 seconds (process IV). In addition, when two aqueous solutions are used in process IV, each aqueous solution is sprayed at 25°C for 30 seconds. The metal material after spraying is placed flat on a flat surface, and the evaluation surface is sprayed with a liquid adhesion amount D (L / m 2 ) in a manner of spraying various chemical conversion treatment agents (chemical conversion treatment agents of Examples 1 to 59 and Comparative Examples 1 to 27) for 120 seconds (Step I). The temperature of the treatment liquid during spraying is 15°C as a low temperature and 38°C as a high temperature. After spraying the chemical conversion treatment liquid, let it stand for a specified time t minutes shown in Tables 1 to 5 (Steps I to II). Then, the surface of the metal material having the obtained chemical conversion film is cleaned with tap water with a pH of 6 and deionized water with a pH of 7 in turn (Step II).

[0165] After washing with water, the test piece for appearance evaluation was dried at 40° C. for 10 minutes. The test piece for corrosion resistance after painting was not dried but was subjected to painting described later.

[0166] [Table 1]

[0167]

[0168] [Table 2]

[0169]

[0170] [Table 3]

[0171]

[0172] [Table 4]

[0173]

[0174] [Table 5]

[0175]

[0176] <Manufacturing of metal materials with coatings>

[0177] After coating on the chemical conversion film formed on the surface of various metal materials, baking is performed to produce a metal material having a coating film.

[0178] The details of the painting method and the baking conditions are shown below.

[0179] (Cationic electrodeposition coating)

[0180] A metal material with various chemical conversion films is used as the cathode, and electrolysis is carried out using a cationic electrodeposition coating (KG-400; manufactured by Kansai Paint Co., Ltd.) to form a coating film. In addition, the electrolysis is carried out at an applied voltage of 180 V and a temperature of 30.0 ± 0.5 °C. Furthermore, the electrolysis is carried out by adjusting the amount of electricity so that the coating film thickness becomes 15.0 ± 1.0 μm. After cationic electrodeposition, the surface of the coating film is washed with deionized water and baked at 170 °C for 20 minutes to produce a metal material (each test piece) with a coating film.

[0181] <Chemical conversion appearance>

[0182] The film appearance of the test pieces with chemical conversion films obtained through each example and comparative example is visually determined.

[0183] <Evaluation criteria>

[0184] A: When observing the test piece from the front, there is no unevenness on the flat part and the edge. When observing the test piece at an angle of 20° from the front, there is no unevenness on the flat part and the edge

[0185] B: When observing the test piece from the front, there is no unevenness on the flat part and the edge. When observing the test piece at an angle of 20° from the front, there is unevenness on the flat part and the edge

[0186] C: When observing the test piece from the front, there is no unevenness on the flat part, there is unevenness on the edge. When observing the test piece at an angle of 20° from the front, there is unevenness on the flat part and the edge

[0187] D: When observing the test piece from the front, there is unevenness on the flat part and the edge. When observing the test piece at an angle of 20° from the front, there is unevenness on the flat part and the edge

[0188] <Corrosion resistance test (exposure test)>

[0189] Using a cutter, an X-shaped incision (cross-cut) reaching the metal substrate is made on the coating film surface of various test pieces with a coating film. After exposing the test pieces to the near-seashore of Okinawa for 2 years, the coating film swelling amplitude (one-sided maximum swelling amplitude) starting from the scratch part (cross-cut part) of the test piece is measured. The corrosion resistance is evaluated according to the following evaluation criteria.

[0190] <Evaluation criteria - cross-cut part>

[0191] A: The one-sided swelling amplitude is less than 5.0 mm

[0192] B: The unilateral expansion amplitude is 5.0 mm or more and less than 10.0 mm

[0193] C: The unilateral expansion amplitude is 10.0 mm or more and less than 15.0 mm

[0194] D: The unilateral expansion amplitude is 15.0 mm or more

[0195] <Corrosion Resistance Test (VDA Method)>

[0196] Use a cutting tool to make an incision 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 version; method C) for six cycles. Measure the coating film expansion amplitude (unilateral maximum expansion amplitude) starting from the incision part (cutting part) of the test piece. Evaluate the corrosion resistance according to the following evaluation criteria.

[0197] <Evaluation Criteria - Cutting Part>

[0198] A: The unilateral expansion amplitude is less than 5.0 mm

[0199] B: The unilateral expansion amplitude is 5.0 mm or more and less than 10.0 mm

[0200] C: The unilateral expansion amplitude is 10.0 mm or more and less than 15.0 mm

[0201] D: The unilateral expansion amplitude is 15.0 mm or more

[0202] The results of each evaluation test are shown in Tables 6 to 8. In addition, in all evaluations, B or above is regarded as the qualified level.

[0203] [Table 6]

[0204]

[0205] [Table 7]

[0206]

[0207] [Table 8]

[0208]

[0209] Although the present invention has been described in detail with reference to specific embodiments, it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

Claims

1. A manufacturing method of a metal material with a chemical conversion film, wherein the chemical conversion film is formed on the surface or surfaces of the metal material. The manufacturing method includes: Step I of bringing the metal material into contact with a chemical conversion treatment agent; and Step II of bringing the metal material after being in contact with the chemical conversion treatment agent into contact with an aqueous solution having a pH of 4.0 or more and 12.0 or less at least once, The chemical conversion treatment agent is formulated with: A supply source of fluoride ions; Supply source A of ions containing zirconium; Supply source B of ions containing aluminum; and A water-soluble or water-dispersible polymer or its salt C having a structural unit represented by the following formula (i) in a molar conversion of 90% or more and in an amount of 0.0001 g / L or more and 1.000 g / L or less, The value obtained by subtracting the value obtained from the following formula (2) from the value obtained from the following formula (1) is 0.2 or more. (Ac + Bc)×(pH - 2.7) 8 … Equation (1) (D / 0.18) 3 ×(t / 1.5) 5 … Equation (2) Here, in the formula (1), Ac is the zirconium element concentration from the supply source A in the chemical conversion treatment agent and is 2 g / L or less. Bc is the aluminum element concentration from the supply source B in the chemical conversion treatment agent and is 2 g / L or less. The ratio Bc / Ac of Bc to Ac is 0.03 or more and 10.0 or less. pH is the pH of the chemical conversion treatment agent and is 3.2 or more and 6.0 or less. In the formula (2), D is the liquid adhesion amount of the chemical conversion treatment agent adhered to the surface of the metal material between Process I and Process II, and is greater than 0 L / m 2 and is 0.5 L / m 2 Hereinafter, t is the time from the end of Step I to the start of Step II and is 0.01 minute or more and 3.00 minutes or less.

2. The manufacturing method of the metal material with a chemical conversion film according to claim 1, wherein Before Step I, it includes: Step III of bringing it into contact with an alkaline solution having a pH of 8.0 or more and 13.0 or less; and Step IV of bringing it into contact with an aqueous solution having a pH of 7.0 or more and 12.0 or less.

3. The manufacturing method of the metal material with a chemical conversion film according to claim 1 or 2, wherein, The metal material is at least one 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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