AU2022294569A1

AU2022294569A1 - Method for manufacturing surface-treated metal member, and aqueous surface treatment agent for processed and cast metal member

Info

Publication number: AU2022294569A1
Application number: AU2022294569A
Authority: AU
Inventors: Yusuke Miura; Yuji Ohtake; Akira Utsunomiya
Original assignee: Nippon Paint Surf Chemicals Co Ltd
Current assignee: Nippon Paint Surf Chemicals Co Ltd
Priority date: 2021-06-17
Filing date: 2022-06-10
Publication date: 2024-01-04
Also published as: TW202307266A; JPWO2022264949A1; WO2022264949A1; KR20240021167A; JP7560188B2; CN117460862A

Abstract

The present invention provides a method for manufacturing a surface-treated metal member with which an amount of chemical sludge can be reduced while achieving corrosion resistance and coating adhesion equivalent to those in the prior art. A method for manufacturing a surface-treated metal member includes: a degreasing and water-washing step for forming a degreased and water-washed metal member; a surface treatment agent contact step for bringing the degreased and water-washed metal member into contact with an aqueous surface treatment agent; and a drying step for drying the metal member having a liquid coating on the surface thereof without washing with water. The aqueous surface treatment agent contains a specific water-based resin (A), a metal compound (B), a chelating agent (C), and water, and the aqueous surface treatment agent has a solid content of 0.01-6 mass% relative to the total mass of the aqueous surface treatment agent.

Description

DESCRIPTION TITLE PRODUCTION METHOD FOR SURFACE-TREATED METAL MEMBER AND WATER-BASED SURFACE TREATMENT AGENT FOR PROCESSED/MOLDED METAL MEMBER TECHNICAL FIELD

[0001] The present disclosure relates to a production method for a surface treated metal member and a water-based surface treatment agent for a processed/molded metal member.

BACKGROUND

[0002] In a situation in which the surface of a metal member is to be coated, the metal member is normally subjected to chemical conversion treatment prior to coating so as to form a chemical conversion film at the surface of the metal member and impart corrosion resistance, coating film close adherence, and so forth to the metal member.

[0003] Phosphate chemical conversion treatment is typically adopted as this chemical conversion treatment. Moreover, zirconium chemical conversion treatment that does not include a harmful heavy metal such as nickel has also started to be used in recent years as a chemical conversion treatment having reduced environmental impact.

[0004] For example, Patent Literature (PTL) 1 discloses a composition for surface preparation that is used for surface preparation of a metal prior to phosphate chemical conversion treatment being performed.

[0005] PTL 2 discloses a composition for metal surface treatment that contains zirconium, fluorine, and a soluble epoxy resin.

CITATION LIST Patent Literature

[0006] PTL 1: JP2007-297709A PTL 2: JP2013-053326A

SUMMARY (Technical Problem)

Ref No. P0222933-PCT-ZZ (1/30)

[0007] However, the composition for surface preparation in PTL 1 and the composition for metal surface treatment in PTL 2 each form a film through a chemical reaction between a metal material surface and a chemical conversion treatment liquid. A surface treatment process in which such a surface treatment agent is used faces issues such as the inability to use the surface treatment agent at normal temperature; the production of chemical conversion sludge as a by-product; the need for at least one water-washing step after chemical conversion treatment; and the need for extensive equipment and cost due to increased treatment time and treatment steps.

[0008] Accordingly, one object of the present disclosure is to provide a production method for a surface-treated metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of sludge that is produced in a chemical conversion reaction (hereinafter, also referred to simply as "chemical conversion sludge").

[0009] Moreover, another object of the present disclosure is to provide a water-based surface treatment agent for a processed/molded metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of chemical conversion sludge. (Solution to Problem)

[0010] A production method for a surface-treated metal member according to the present disclosure comprises: a degreasing and water-washing step of degreasing and then water washing a metal member to form a degreased and water-washed metal member; a surface treatment agent contacting step of bringing the degreased and water-washed metal member into contact with a water-based surface treatment agent to form a metal member having a liquid film at a surface; and a drying step of drying the metal member having the liquid film at the surface, without performing water-washing, to form a metal member having a surface treatment film, wherein the water-based surface treatment agent contains an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer,

Ref No. P0222933-PCT-ZZ (2/30) the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent. This makes it possible to achieve corrosion resistance and coating film close adherence equivalent to those in the prior art even when heating of a chemical conversion treatment tank or water-washing after chemical conversion treatment is omitted.

[0011] In one embodiment of the production method according to the present disclosure, the amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 3 mass% relative to total mass of the water-based surface treatment agent.

[0012] In one embodiment of the production method according to the present disclosure, the metal member is a processed/molded member.

[0013] In one embodiment of the production method according to the present disclosure, fluoride ion content in the water-based surface treatment agent is less than 0.005 mass%.

[0014] In one embodiment of the production method according to the present disclosure, the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound.

[0015] In one embodiment of the production method according to the present disclosure, when a number of equivalents of a metal element in the metal compound (B) is taken to be EB and a number of equivalents of a metal coordination site in the chelating agent (C) is taken to be EC, EB relative to EC is within a range of 0.50 to 4.00.

[0016] In one embodiment of the production method according to the present disclosure, the aqueous resin (A) is a resin that includes two or more types of groups selected from the group consisting of a primary amino group, a

Ref No. P0222933-PCT-ZZ (3/30) secondary amino group, a carboxyl group, a hydroxy group, a urethane group, and a ureido group.

[0017] In one embodiment of the production method according to the present disclosure, the aqueous resin (A) includes one or more selected from the group consisting of an acrylic-modified epoxy resin, a carbon-carbon unsaturated bond-containing polyurethane resin, and an aromatic ring structure-containing polyurethane resin.

[0018] In one embodiment of the production method according to the present disclosure, the chelating agent (C) includes one or more selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N methylethanolamine, ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, 1-hydroxyethane-1,1 diphosphonic acid, and 2-phosphonobutane-1,2,4-butanetricarboxylic acid.

[0019] A water-based surface treatment agent according to the present disclosure is for a processed/molded metal member and comprises an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, wherein the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent. This makes it possible to achieve corrosion resistance and coating film close adherence equivalent to those in the prior art even when heating of a chemical conversion treatment tank or water-washing after chemical conversion treatment is omitted.

[0020] In one embodiment of the water-based surface treatment agent according to the present disclosure, the amount of solid content in the water based surface treatment agent is within a range of 0.01 mass% to 3 mass%

Ref No. P0222933-PCT-ZZ (4/30) relative to total mass of the water-based surface treatment agent. (Advantageous Effect)

[0021] According to the present disclosure, it is possible to provide a production method for a surface-treated metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of chemical conversion sludge. Moreover, according to the present disclosure, it is possible to provide a water based surface treatment agent for a processed/molded metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of chemical conversion sludge.

DETAILED DESCRIPTION

[0022] The following describes embodiments of the present disclosure. The following description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way.

[0023] Two or more of the embodiments can be freely combined.

[0024] Herein, the terms "film" and "coating film" can be used interchangeably.

[0025] The term "solid content" is a concept that is inclusive of solid content, non-volatile content, and active ingredients.

[0026] Numerical ranges given in the present specification are intended to include the upper limit and the lower limit of that range, unless specified otherwise. For example, 0.01 mass% to 6 mass% indicates a range of not less than 0.01 mass% and not more than 6 mass%.

[0027] In the present specification, an aqueous resin (A), a metal compound (B), and a chelating agent (C) may be referred to simply as an "A component", "B component", and "C component", respectively.

[0028] A surface treatment agent contacting step may also be referred to simply as a "contacting step" in the present specification.

[0029] Herein, the term "primary amino group" refers to "-NH 2 ", the term "secondary amino group" refers to ">NH", the term "urethane group" refers to a "structure represented by -NH-(C=O)-O-", and the term "ureido group" refers to a "structure represented by -NH-(C=0)-NH-".

[0030] In the present specification, "(meth)acrylic acid" indicates "one or more selected from the group consisting of acrylic acid and methacrylic acid".

Ref No. P0222933-PCT-ZZ (5/30)

[0031] (Production method for surface-treated metal member) The production method for a surface-treated metal member according to the present disclosure comprises: a degreasing and water-washing step of degreasing and then water washing a metal member to form a degreased and water-washed metal member; a surface treatment agent contacting step of bringing the degreased and water-washed metal member into contact with a water-based surface treatment agent to form a metal member having a liquid film at a surface; and a drying step of drying the metal member having the liquid film at the surface, without performing water-washing, to form a metal member having a surface treatment film, wherein the water-based surface treatment agent contains an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent.

[0032] The following describes each step of the production method for a surface-treated metal member according to the present disclosure.

[0033] 1 Degreasing and water-washing step In the degreasing and water-washing step, degreasing and then water washing are performed with respect to a metal member to form a degreased and water-washed metal member. Oil content and/or dirt attached to the surface of the metal member is removed through this degreasing. Moreover, degreasing agent present at the surface of the metal member after the degreasing treatment is removed through the water-washing performed after degreasing.

[0034] Any commonly known metal member can be used as the metal member Ref No. P0222933-PCT-ZZ (6/30) without any specific limitations. For example, the metal member may be an iron-based substrate, an aluminum-based substrate, a zinc-based substrate, a magnesium-based substrate, or the like. The iron-based substrate is a substrate that is one or more selected from the group consisting of iron and an iron alloy. The aluminum-based substrate is a substrate that is one or more selected from the group consisting of aluminum and an aluminum alloy. The zinc-based substrate is a substrate that is one or more selected from the group consisting of zinc and a zinc alloy. The magnesium-based substrate is a substrate that is one or more selected from the group consisting of magnesium and a magnesium alloy.

[0035] In one embodiment of the production method according to the present disclosure, the metal member is a processed/molded member. The processed/molded member may be a processed/molded member that has undergone laser processing, press processing, or the like, for example.

[0036] No specific limitations are placed on the method of degreasing. For example, a degreasing agent and degreasing conditions described in PTL 2 can be adopted.

[0037] 1 Surface treatment agent contacting step In the surface treatment agent contacting step, the degreased and water washed metal member is brought into contact with the water-based surface treatment agent to form a metal member having a liquid film at a surface.

[0038] 1 Water-based surface treatment agent The water-based surface treatment agent that is used in the production method according to the present disclosure contains an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, wherein the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group, and an amount of solid content in the water-based surface treatment agent

Ref No. P0222933-PCT-ZZ (7/30) is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent.

[0039] * A component The A component includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer. From a viewpoint of corrosion resistance of a chemical conversion treatment film with respect to the metal member, the A component is preferably an aqueous epoxy resin.

[0040] One example of a preferred form of the aqueous epoxy resin is an acrylic-modified epoxy resin. The inclusion of an acrylic-modified epoxy resin is advantageous in terms that good close adherence of a chemical conversion treatment film with respect to the metal member can be ensured.

[0041] Examples of commercially available products for the acrylic-modified epoxy resin include MODEPICS 301, MODEPICS 302, MODEPICS 303, and MODEPICS 304 (product names) produced by Arakawa Chemical Industries, Ltd.

[0042] Besides the above examples, an aqueous epoxy resin that is described in PTL 1, JP2005-008975A, or the like, for example, can be used as the aqueous epoxy resin.

[0043] One aqueous epoxy resin may be used individually, or two or more aqueous epoxy resins may be used in combination.

[0044] The aqueous polyurethane resin is not specifically limited and may, for example, be an aqueous polyurethane resin described in JP2005-008975A, or the like.

[0045] In one embodiment, the A component includes one or more selected from the group consisting of a carbon-carbon unsaturated bond and an aromatic ring structure in a molecule thereof.

[0046] In one embodiment of the production method according to the present disclosure, the aqueous resin (A) is a resin that includes two or more types of groups selected from the group consisting of a primary amino group (-NH 2 ), a secondary amino group (>NH), a carboxyl group, a hydroxy group, a urethane group, and a ureido group. From a viewpoint of increasing corrosion resistance of a chemical conversion treatment film, a resin that includes two or more of the types of functional groups listed above is preferable.

[0047] The aqueous polyurethane resin is not specifically limited, and an example thereof is a product obtained by reacting a polyol compound and a

Ref No. P0222933-PCT-ZZ (8/30) diisocyanate compound, further performing chain extension with a diamine or the like, and then performing dispersion in water.

[0048] A commercially available product may be used as the aqueous polyurethane resin. Examples of commercially available products include HUX-320 and HUX-550 (product names) produced by Adeka Corporation, SUPERFLEX© (SUPERFLEX is a registered trademark in Japan, other countries, or both) produced by DKS Co., Ltd., and HYDRAN© (HYDRAN is a registered trademark in Japan, other countries, or both) produced by DIC Corporation.

[0049] One aqueous polyurethane resin may be used individually, or two or more aqueous polyurethane resins may be used in combination.

[0050] The aqueous silicone oligomer is not specifically limited and can, for example, be a silicone oligomer (A) described in JP6058843B1, or the like.

[0051] A commercially available product maybe used as the silicone oligomer. Examples of commercially available products include methyl methoxy-type oligomers such as KC-89, KR-500, X-40-9225, X-40-9246, and X-40-9250 (product names) produced by Shin-Etsu Chemical Co., Ltd.; phenyl methoxy type oligomers such as KR-217 (product name) produced by Shin-Etsu Chemical Co., Ltd.; aminosilane oligomers such as a condensate of KBM-903 (product name) produced by Shin-Etsu Chemical Co., Ltd.; methyl/phenyl methoxy-type oligomers such as KR-9218, KR-213, KR-510, X-40-9227, X 40-9247, and KR-401N (product names) produced by Shin-Etsu Chemical Co., Ltd.; and methyl methoxy-type oligomers such as MSE-100 (product name) produced by Wacker Silicone.

[0052] One aqueous silicone oligomer may be used individually, or two or more aqueous silicone oligomers may be used in combination.

[0053] In one embodiment of the production method according to the present disclosure, the aqueous resin (A) includes one or more selected from the group consisting of an acrylic-modified epoxy resin, a carbon-carbon unsaturated bond-containing polyurethane resin, and an aromatic ring structure-containing polyurethane resin.

[0054] The amount of the A component should be adjusted as appropriate and may be 20 mass% to 80 mass% relative to all solid content in the water-based surface treatment agent, for example. In one embodiment, the amount of the A component is 20 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, 60 mass% or more, or 70 mass% or more relative to all solid

Ref No. P0222933-PCT-ZZ (9/30) content in the water-based surface treatment agent. In another embodiment, the amount of the A component is 80 mass% or less, 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, or 30 mass% or less relative to all solid content in the water-based surface treatment agent.

[0055] * B component The B component includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium. The B component acts in conjunction with the A component to impart good corrosion resistance.

[0056] The B component may be a carbonate, phosphate, nitrate, sulfate, acetate, oxide, hydroxide, organic acid salt, complex compound, or the like that includes any of the aforementioned metal elements, for example. The B component may be a simple salt or may be a double salt.

[0057] Examples of the B component that include magnesium include magnesium nitrate, magnesium sulfate, magnesium acetate, and magnesium oxide.

[0058] Examples of the B component that include aluminum include aluminum nitrate, aluminum sulfate, aluminum acetate, and aluminum oxide.

[0059] Examples of the B component that include titanium include titanium nitrate, titanyl nitrate, titanyl sulfate, titanium sulfate, titanium oxide, diisopropoxytitanium bis(acetylacetone), a reaction product of lactic acid and titanium alkoxide, titanium laurate, titanium acetylacetonate, and barium titanate.

[0060] Examples of the B component that include zirconium include zirconyl nitrate, zirconyl acetate, zirconium acetate, zirconium sulfate, zirconyl sulfate, titanium sulfate, basic zirconium sulfate, zirconium oxyphosphate, zirconium phosphate, sodium zirconium phosphate, ammonium zirconyl carbonate, ammonium zirconium carbonate, potassium zirconium carbonate, basic zirconium carbonate, zirconium oxide, zirconium hydroxide, zirconium acetylacetonate, and calcium zirconate.

[0061] A metal compound that includes zirconium can suitably be used as the B component, and ammonium zirconium carbonate, potassium zirconium carbonate, or the like, for example, can particularly suitably be used as the B component.

[0062] One B component may be used individually, or two or more B components may be used in combination.

Ref No. P0222933-PCT-ZZ (10/30)

[0063] The amount of the B component should be adjusted as appropriate and may be 10 mass% to 70 mass% relative to all solid content in the water-based surface treatment agent, for example. In one embodiment, the amount of the B component is 10 mass% or more, 20 mass% or more, 25 mass% or more, 30 mass% or more, 40 mass% or more, 50 mass% or more, or 60 mass% or more relative to all solid content in the water-based surface treatment agent. In another embodiment, the amount of the B component is 70 mass% or less, 60 mass% or less, 50 mass% or less, 40 mass% or less, 30 mass% or less, or 20 mass% or less relative to all solid content in the water-based surface treatment agent.

[0064] In one embodiment of the production method according to the present disclosure, when a number of equivalents of a metal element in the metal compound (B) is taken to be EB and a number of equivalents of a metal coordination site in the chelating agent (C) is taken to be EC, EB relative to EC is within a range of 0.50 to 4.00.

[0065] One example of calculation of EB relative to EC is given based on Example 1, which is described further below. Ammonium zirconium carbonate (NH 4 )2ZrO(CO3)2 serving as the B component is taken to be 263.33 g/mol, and diethanolamine is taken to be 105.14 g/mol. In Example 1, 99.6 parts by mass of (NH 4 )2ZrO(CO3)2 corresponds to 99.6/263.33 = 0.378 mol = 378 mmol. Note that since 1 mol of Zr is contained in1 mol of (NH4)2ZrO(CO3)2, EB is 378 mmol. On the other hand, 9.9 parts by mass (in terms of active ingredient) of diethanolamine in Example 1 corresponds to 9.9/105.14 = 0.0942 mol = 94.2 mmol. Since the number of metal coordination sites in diethanolamine is 3 (two hydroxy groups and one NH group), the number of moles of metal coordination sites (i.e., EC) is 94.2 mmol x 3 = 282.6 mmol. Accordingly, EB/EC= 378/282.6 = 1.337 ~ 1.34.

[0066] * C component The C component is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group.

[0067] Examples of chelating agents that can preferably be used include alkanolamines, hydroxy group-containing organic phosphonic acid compounds, and carboxyl group-containing organic phosphonic acid compounds.

Ref No. P0222933-PCT-ZZ (11/30)

[0068] Examples of alkanolamines include monoethanolamine, diethanolamine, triethanolamine, N-butylethanolamine, N methylethanolamine, 2-amino-2-methyl-1-propanol, dimethylethanolamine, dibutylethanolamine,andmethyldiethanolamine.

[0069] Examples of hydroxy group-containing organic phosphonic acid compounds include hydroxymethane diphosphonic acid, 1-hydroxyethane-1,1 diphosphonic acid, and 1-hydroxypropane-1,1-diphosphonic acid.

[0070] Examples of carboxyl group-containing organic phosphonic acid compounds include 2-hydroxyphosphonoacetic acid and 2-phosphonobutane 1,2,4-butanetricarboxylic acid.

[0071] In one embodiment of the production method according to the present disclosure, the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound.

[0072] An alkanolamine can particularly suitably be used as the C component.

[0073] In one embodiment of the production method according to the present disclosure, the chelating agent (C) includes one or more selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N methylethanolamine, ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, 1-hydroxyethane-1,1 diphosphonic acid, and 2-phosphonobutane-1,2,4-butanetricarboxylic acid.

[0074] One C component may be used individually, or two or more C components may be used in combination.

[0075] The amount of the C component should be adjusted as appropriate and may be 2 mass% to 30 mass% relative to all solid content in the water-based surface treatment agent, for example. In one embodiment, the amount of the C component is 2 mass% or more, 5 mass% or more, 10 mass% or more, 15 mass% or more, 20 mass% or more, or 25 mass% or more relative to all solid content in the water-based surface treatment agent. In another embodiment, the amount of the C component is 30 mass% or less, 25 mass% or less, 20 mass% or less, 15 mass% or less, 10 mass% or less, or 5 mass% or less relative to all solid content in the water-based surface treatment agent.

[0076] The water-based surface treatment agent contains water. The amount of water can be set as an amount such that solid content in the water-based surface

Ref No. P0222933-PCT-ZZ (12/30) treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water-based surface treatment agent. The water-based surface treatment agent can contain an organic solvent to the extent that the effects according to the present disclosure are not lost.

[0077] The amount of solid content in the water-based surface treatment agent is an amount that falls within a range of 0.01 mass% to 6 mass% relative to total mass of the water-based surface treatment agent. The amount of solid content may preferably be 0.1 mass% to 3 mass% or 0.1 mass% to 1 mass%.

[0078] The water-based surface treatment agent can be a water-based surface treatment agent that does not contain fluoride ions. Alternatively, the water based surface treatment agent may contain fluoride ions as an unavoidable impurity.

[0079] In one embodiment of the production method according to the present disclosure, the water-based surface treatment agent does not contain fluoride ions or contains fluoride ions as an unavoidable impurity.

[0080] The method by which the degreased and water-washed metal member is brought into contact with the water-based surface treatment agent may be immersion, spraying, roll coating, bar coating, or the like, for example, without any specific limitations. Alternatively, the water-based surface treatment agent may be caused to freely flow over and come into contact with the degreased and water-washed metal member.

[0081] No specific limitations are placed on conditions in terms of temperature and time in contacting of the degreased and water-washed metal member with the water-based surface treatment agent. The temperature of the water-based surface treatment agent during contacting can be set as a temperature of10°C to 40 0 C that is the same as the external air temperature, for example. The time for which contacting is performed can be freely set in accordance with conditions such as the equipment and member that are adopted and can be set as 10 seconds to 30 seconds, for example.

[0082] In the present disclosure, the use of the water-based surface treatment agent described above makes it possible to adopt a lower temperature (for example, normal temperature) than is conventionally adopted as the temperature of a water-based surface treatment agent in a contacting step. Although heating may be performed to the minimum degree necessary to melt the water-based surface treatment agent in a situation in which the water-based surface treatment agent freezes in a cold environment, heating of the water

Ref No. P0222933-PCT-ZZ (13/30) based surface treatment agent is not necessary in a normal environment. In one embodiment, the contacting step is performed without a heating means for maintaining the temperature of the water-based surface treatment agent at 400 C or higher, 38 0 C or higher, or 350 C or higher.

[0083] The amount of solid content in a liquid film that is formed at the surface of the metal member in the contacting step may be within a range of 0.01 mass% to 6 mass%, for example.

[0084] The amount of solid content in a liquid film formed in the surface treatment agent contacting step is in any case within a range of 0.01 mass% to 6 mass%.

[0085] 1 Drying step In the drying step, the metal member having the liquid film at the surface is dried to form a metal member having a surface treatment film without performing water-washing. By performing the drying without water-washing, it is possible to reduce wastewater cost and industrial waste cost. Moreover, the formation of sludge in a chemical conversion reaction does not occur.

[0086] In conventional reaction-type chemical conversion treatment, water washing is performed in order to avoid the following three problems that arise when water-washing is not performed. The first problem is that reactive chemical conversion treatment liquid remains at the surface of the metal member, and thus reaction of a film cannot be controlled and the target film cannot be obtained. The second problem is that typical reaction-type chemical conversion treatment agents are acidic and cause the formation of manufacturing rust when they remain at the surface of a metal member such as a steel sheet. The third problem is that reaction-type chemical conversion treatment causes the formation of chemical conversion sludge during treatment, and this sludge adheres to the surface of a metal member, leading to external appearance abnormalities in coating performed after chemical conversion.

[0087] In contrast, the water-based surface treatment agent used in the present disclosure is a non-reaction type agent, and thus the formation of a surface treatment film does not involve a chemical conversion reaction. Since a chemical conversion reaction is not involved, the formation of sludge in a chemical conversion reaction does not occur. Consequently, the production method according to the present disclosure eliminates the need for water washing that is necessary in conventional reaction-type chemical conversion treatment such as described above.

Ref No. P0222933-PCT-ZZ (14/30)

[0088] The drying temperature and the drying time after application of the surface treatment agent are not specifically limited so long as a temperature and time that enable evaporation of unnecessary components (for example, water and/or organic solvent) from the film are adopted. For example, a method in which a hot air dryer (for example, a PHH-202 produced by ESPEC Corp.) is used to perform 3 minutes of drying inside a 100°C dryer can be adopted. Moreover, the drying may be performed after excess treatment liquid is removed by air blowing or the like, as necessary, prior to drying.

[0089] The dry film-thickness of the surface treatment film formed through drying is not specifically limited and may be 0.001 pm to 1.0 pm, for example. In one embodiment, the dry film-thickness of the surface treatment film is 0.002 pm to 1.0 pm, or 0.002 pm to 0.5 pm. In another embodiment, the dry film-thickness of the surface treatment film is 0.002 pm or more, 0.005 pm or more, 0.010 pm or more, 0.050 pm or more, 0.100 pm or more, 0.500 pm or more, or 1.000 pm or more. In yet another embodiment, the dry film-thickness of the surface treatment film is 2.000 pm or less, 1.000 pm or less, 0.500 pm or less, 0.100 pm or less, 0.050 pm or less, 0.010 pm or less, or 0.005 Pm or less.

[0090] 1 Other steps The production method for a surface-treated metal member according to the present disclosure may optionally include other steps in addition to the degreasing and water-washing step, the contacting step, and the drying step. For example, a coating step of applying a coating composition onto the metal member or onto the surface treatment film to form a coating film after the drying step may be included as another step.

[0091] The coating composition used in the coating step is not specifically limited and should be selected as appropriate depending on the application, etc.

[0092] The coating method used in the coating step can be a commonly known coating method such as immersion, spraying, roll coating, bar coating, brush coating, or roller coating without any specific limitations. In one embodiment, the coating method in the coating step is spraying.

[0093] (Water-based surface treatment agent) The water-based surface treatment agent according to the present disclosure is for a processed/molded metal member and contains an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, wherein the aqueous resin (A) includes one or more selected from the group

Ref No. P0222933-PCT-ZZ (15/30) consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent.

[0094] The water-based surface treatment agent described in the contacting step of the production method for a surface-treated metal member set forth above (hereinafter, also referred to as a "first water-based surface treatment agent") and the water-based surface treatment agent according to the present disclosure (hereinafter, also referred to as a "second water-based surface treatment agent") differ in terms of scope of the C component, but are the same with regards to other components, amounts, and so forth. More specifically, the C component in the first water-based surface treatment agent is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group, whereas the C component in the second water-based surface treatment agent is one or more selected from the group consisting of an alkanolamine, a hydroxy group containing organic phosphonic acid compound, and a carboxyl group containing organic phosphonic acid compound. Accordingly, the C component in the first water-based surface treatment agent is a broader generic concept compared to the C component in the second water-based surface treatment agent.

[0095] The one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound that constitute the C component in the second water-based surface treatment agent are as previously described for the C component in the first water-based surface treatment agent.

Ref No. P0222933-PCT-ZZ (16/30)

[0096] The second water-based surface treatment agent is for surface treatment of a processed/molded metal member. The processed/molded metal member may be a processed/molded metal member that has undergone laser processing, press processing, or the like, for example.

[0097] Besides the A to C components, additives such as typical organic and inorganic rust inhibitors and surface conditioners can be used in the water based surface treatment agent according to the present disclosure to the extent that the object thereof is not lost. Examples of such additives include imidazole and benzotriazole.

EXAMPLES

[0098] The following provides a more detailed description of the present disclosure through examples. However, these examples are for illustrative purposes and are not intended to limit the scope of the present disclosure in any way.

[0099] Materials of water-based surface treatment agents used in the examples were as follows. A component Aqueous epoxy resin: EPICLON© (EPICLON is a registered trademark in Japan, other countries, or both) H-502-42W (product name) produced by DIC Corporation; aqueous modified phenoxy resin; solid content 39 mass% to 43 mass%; including hydroxy groups and carboxyl groups; denoted as "EPICLON" in Tables 1 and 2 Aqueous epoxy resin: MODEPICS© (MODEPICS is a registered trademark in Japan, other countries, or both) 301 (product name) produced by Arakawa Chemical Industries, Ltd.; solid content 32% to 34%; including hydroxy groups and carboxyl groups; denoted as "MODEPICS" in Tables 1 and 2 Aqueous polyurethane resin: HUX-320 (product name) produced by Adeka Corporation; solid content 30% to 34%; aromatic ring structure containing polyurethane resin including urethane groups and carboxyl groups; denoted as "HUX320" in Table 1 Aqueous polyurethane resin: HUX-550 (product name) produced by Adeka Corporation; solid content 26.5% to 29.5%; aromatic ring structure containing polyurethane resin including urethane groups and carboxyl groups; denoted as "HUX550" in Table 1

Ref No. P0222933-PCT-ZZ (17/30)

Aqueous silicone oligomer: Solution of hydrolysis-condensation product of KBM-903 (product name) produced by Shin-Etsu Chemical Co., Ltd.; solid content 20%; including hydroxy groups and primary amino groups; denoted as "903 condensate" in Table 1 •Comparative A component Acrylic resin: NP-900A (product name) produced by Saiden Chemical Industry Co., Ltd.; solid content 47% to 49%; denoted as "900A" in Table 2 B component Ammonium zirconium carbonate: Zircosol AC-7 (product name) produced by Daiichi Kigenso Kagaku Kogyo Co., Ltd.; (NH 4 )2ZrO(CO3)2; solid content 29%; denoted as "AC-7"in Tables 1 and 2 Zirconyl nitrate: EKZ-5 (product name) produced by Daiichi Kigenso Kagaku Kogyo Co., Ltd.; ZrO(NO3)2; solid content 40%; denoted as "ZN" in Table 1 Titanium bis(triethanolamine)diisopropoxide: ORGATIX TC-400 (product name) produced by Matsumoto Fine Chemical Co., Ltd.; Ti(O-i C 3 H 7 ) 2 (C 6 H 4 0 3 N) 2 ; solid content 79%; denoted as "TC400" in Table 1 Aluminum acetate: Basic aluminum acetate (reagent) produced by FUJIFILM Wako Pure Chemical Corporation; Al(OH)(CH 3 COO) 2 ; solid content 100%; denoted as "Al acetate" in Table 1 Magnesium oxide: Magnesium oxide (reagent) produced by FUJIFILM Wako Pure Chemical Corporation; MgO; solid content 100%; denoted as "MgO" in Table 1 * C component Diethanolamine: Diethanolamine (reagent) produced by FUJIFILM Wako Pure Chemical Corporation; alkanolamine; molecular weight 105.14; including one amino group as a first metal coordination site and two hydroxy groups as second metal coordination sites; active ingredient concentration 99% or more; denoted as "Diethanolamine" in Tables 1 and 2 Triethanolamine: 2,2',2"-Nitrilotriethanol (reagent) produced by FUJIFILM Wako Pure Chemical Corporation; alkanolamine; molecular weight 149.19; including one amino group as a first metal coordination site and three hydroxy groups as second metal coordination sites; active ingredient concentration 98% or more; denoted as "Triethanolamine" in Tables 1 and 2 1-Hydroxyethane-1,1-diphosphonic acid: PH-210 (product name) produced by Chelest Corporation; molecular weight 206.03; including two

Ref No. P0222933-PCT-ZZ (18/30) phosphonic acid groups as first metal coordination sites and one hydroxy group as a second metal coordination site; solid content 60%; denoted as "HEDP" in Table 1 2-Phosphonobutane-1,2,4-tricarboxylic acid: PH-430 (product name) produced by Chelest Corporation; molecular weight 270.13; including one phosphonic acid group as a first metal coordination site and three carboxyl groups as second metal coordination sites; solid content 50%; denoted as "PBTC" in Table 1 * Comparative C component Citric acid: Produced by FUJIFILM Wako Pure Chemical Corporation; molecular weight 192.123; solid content 100%; denoted as "CA" in Table 2 Acetylacetone: Produced by FUJIFILM Wako Pure Chemical Corporation; molecular weight 100.117; active ingredient concentration 99% or more; denoted as "AA" in Table 2 * Surface treatment agent for zinc phosphate treatment: SURFDINE 6350 (product name) produced by Nippon Paint Surf Chemicals Co., Ltd.

[0100] Other materials were as follows. Degreasing agent: SURFCLEANER 53NF (product name) produced by Nippon Paint Surf Chemicals Co., Ltd. Surface conditioner: SURFFINE GLI (product name) produced by Nippon Paint Surf Chemicals Co., Ltd. Powder paint: Biryusia PL1000 (product name) produced by Nippon Paint Industrial Coatings Co., Ltd. Metal member: Cold rolled steel sheet (SPC270D produced by Paltec Co., Ltd.) Cellophane tape: Cellotape© (Cellotape is a registered trademark in Japan, other countries, or both) produced by Nichiban Co., Ltd.

[0101] 1 Examples 1 to 17 and Comparative Examples 1 to 3 Components and water were mixed in a formulation indicated in Table 1 or 2 to prepare a water-based surface treatment agent. The amounts of the components are parts by mass of solid content. The amount of solid content in the water-based surface treatment agent is also shown in Table 1 or 2. Moreover, a value for the number of equivalents EB of a metal element in a B component relative to the number of equivalents EC of a metal coordination site in a C component is also shown in Table 1 or 2. Fluoride ions were not added in preparation of the water-based surface treatment agents of Examples 1 to 17

Ref No. P0222933-PCT-ZZ (19/30) and Comparative Examples 1 to 3.

[0102] * SURFDINE 6350, which is a surface treatment agent for zinc phosphate treatment, was used as a surface treatment agent in Comparative Example 4.

[0103] [Table 1]

Ref No. P0222933-PCT-ZZ (20/30)

00 C)

CIA CLCZ

V000

cMI -IZ

001

LC~~~ C Z/ j C C t

Ct'

C5 U

Re o 0223-C-Z 2/0

[0104] [Table 2]

*4z

m om m Ncz

- ; o a cs- oaao

oz m

c~ O)

moc

..... . .. .. .~~ .

22 co z

I~~ ~ II ... .. .. .

cz ccz

~~~~~~~ oS-z C

-~Re z o . ea No P0293PTZ (22/o30oo)

0 Q 00 0 oQ 0

Ref-oP022.33-PT-ZZ(2/30

[0105] Degreasing and water-washing step The cold rolled steel sheet serving as a metal member was immersed for 120 seconds in the degreasing agent, which was heated to a temperature of 40°C, so as to perform degreasing and was then thoroughly water-washed with tap water to obtain a degreased and water-washed metal member.

[0106] 1 Surface treatment agent contacting step The water-based surface treatment agent prepared in Example 1 was sprayed against the degreased and water-washed metal member for 30 seconds at room temperature (25°C) without heating so as to bring the metal member into contact with the water-based surface treatment agent and form a liquid film of the water-based surface treatment agent at the surface of the metal member.

[0107] 1 Drying step The metal member having the liquid film at the surface was dried in a dryer having a temperature of 100°C, without performing water-washing, to obtain a metal member having a surface treatment film. The dry film-thickness of the surface treatment film was 0.06 pm.

[0108] 1 Coating step Next, the powder paint was coated onto the surface treatment film by spraying such as to have a dry film-thickness of at least 60 Pm and was dried to form a coating film.

[0109] In Examples 2 to 17 and Comparative Examples I to 3, these four steps were performed in the same way as in Example 1 to form a surface treatment film and a coating film in order from the metal member-side with the exception that the water-based surface treatment agent of Example 1 was changed to the water-based surface treatment agent of that example or comparative example. The dry film-thickness of the surface treatment film was within a range of 0.002 pm to 0.5 pm in each case, with the exception of Example 17. The dry film-thickness of the surface treatment film in Example 17 was within a range of 0.002 pm to 1.0 pm.

[0110] In Comparative Example 4, the degreasing and water-washing step was performed in the same way as in Example 1. Next, the surface conditioner was used to perform surface preparation treatment by 30 seconds of immersion at room temperature. Next, the zinc phosphate treatment agent was used to perform chemical conversion treatment by immersion at 35°C for 2 minutes. Next, water-washing treatment was performed thoroughly using tap water, and

Ref No. P0222933-PCT-ZZ (23/30) then water-washing treatment was performed thoroughly in the same manner using pure water. Next, the drying step and the coating step were performed in the same way as in Example 1 to form a surface treatment film and a coating film in order from the metal member-side. The dry film-thickness of the surface treatment film was 2 pm. In Comparative Example 4, sludge was formed during chemical conversion treatment using the zinc phosphate treatment agent.

[0111] The metal member having a surface treatment film and a coating film that was obtained in each example or comparative example was subjected to testing as described below to evaluate corrosion resistance and coating film close adherence. The results are shown in Tables 1 and 2.

[0112] 1 Production of test sheet for corrosion resistance A cross-shaped cross-cut (cut length 5 cm) was made in the coating film surface of the metal member to prepare a test sheet.

[0113] 1 Corrosion resistance (SST) test The test sheet was subjected to a salt spray test (SST) for 500 hours under conditions in JIS Z 2371:2015. Next, cellophane tape was affixed to the cross-cut section, this cellophane tape was peeled off, and the maximum peeling width at one side from the cross-cut section was measured. A point score was allocated based on the following standard. A score of 4 points or 5 points is a pass. 5 Points: No peeling 4 Points: Peeling with maximum peeling width of less than 3 mm 3 Points: Maximum peeling width of not less than 3 mm and less than 5 mm 2 Points: Maximum peeling width of not less than 5 mm and less than 10 mm 1 Point: Maximum peeling width of 10 mm or more

[0114] 1 Corrosion resistance (CCT) test The test sheet was subjected to a cyclic corrosion test (CCT) for 500 hours under conditions in JASO M609. The maximum blistering width from the cross-cut section was measured. A point score was allocated based on the following standard. A score of 4 points or 5 points is a pass. 5 Points: Blistering with maximum blistering width of less than 3 mm 4 Points: Maximum blistering width of not less than 3 mm and less than 5 mm 3 Points: Maximum blistering width of not less than 5 mm and less than

Ref No. P0222933-PCT-ZZ (24/30)

7 mm 2 Points: Maximum blistering width of not less than 7 mm and less than 10 mm 1 Point: Maximum blistering width of 10 mm or more

[0115] 1 Corrosion resistance (SDT) test The test sheet was subjected to a salt dipping test (SDT) for 500 hours under conditions of 25°C and salt water having a NaCl concentration of 3%. Next, the maximum peeling width at one side from the cross-cut section was measured in the same way as in the SST test. A point score was allocated based on the following standard. A score of 4 points or 5 points is a pass. 5 Points: No peeling 4 Points: Peeling with maximum peeling width of less than 3 mm 3 Points: Maximum peeling width of not less than 3 mm and less than 5 mm 2 Points: Maximum peeling width of not less than 5 mm and less than 10 mm 1 Point: Maximum peeling width of 10 mm or more

[0116] 1 Production of test sheet for coating film close adherence Scratches were made in the coating film surface of the metal member in a grid shape at intervals of 1 mm such as to form 100 squares and thereby prepare a test sheet.

[0117] 1 Coating film close adherence test Cellophane tape was affixed to the scratched section of the test sheet. This cellophane tape was then peeled off, and the number of 1 mm-square coating films that remained on the test sheet without being peeled off was measured. A point score was allocated based on the following standard. A score of4 points or 5 points is a pass. 5 Points: Number of remaining coating films is 100 4 Points: Number of remaining coating films is not less than 80 and less than 100 3 Points: Number of remaining coating films is not less than 60 and less than 80 2 Points: Number of remaining coating films is not less than 40 and less than 60 1 Point: Number of remaining coating films is less than 40

[0118] 1 Preservation stability test

Ref No. P0222933-PCT-ZZ (25/30)

The water-based surface treatment agents obtained in the examples and comparative examples and the surface treatment agent for zinc phosphate treatment of Comparative Example 4 were each left at rest for 30 days in a 40°C constant temperature tank. The presence or absence of gelation or sediment in the treatment agent was then visually observed and was evaluated by the following standard. The results are shown in Tables 1 and 2. Pass: Gelation and sediment not present Fail: Gelation or sediment present

[0119] According to the present disclosure, it was possible to provide a production method for a surface-treated metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art could be achieved while also reducing the amount of chemical conversion sludge. Moreover, according to the present disclosure, it was possible to provide a water-based surface treatment agent for a processed/molded metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art could be achieved while also reducing the amount of chemical conversion sludge.

INDUSTRIAL APPLICABILITY

[0120] According to the present disclosure, it is possible to provide a production method for a surface-treated metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of chemical conversion sludge. Moreover, according to the present disclosure, it is possible to provide a water based surface treatment agent for a processed/molded metal member with which corrosion resistance and coating film close adherence equivalent to those in the prior art can be achieved while also reducing the amount of chemical conversion sludge.

Ref No. P0222933-PCT-ZZ (26/30)

Claims

[Claim 1] A production method for a surface-treated metal member comprising: a degreasing and water-washing step of degreasing and then water washing a metal member to form a degreased and water-washed metal member; a surface treatment agent contacting step of bringing the degreased and water-washed metal member into contact with a water-based surface treatment agent to form a metal member having a liquid film at a surface; and a drying step of drying the metal member having the liquid film at the surface, without performing water-washing, to form a metal member having a surface treatment film, wherein the water-based surface treatment agent contains an aqueous resin (A), a metal compound (B), a chelating agent (C), and water, the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is a chelating agent that includes, in a single molecule, at least one first metal coordination site selected from the group consisting of an amino group and a phosphonic acid group and at least one second metal coordination site selected from the group consisting of a carboxyl group and a hydroxy group, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent.
[Claim 2] The production method according to claim 1, wherein the amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 3 mass% relative to total mass of the water-based surface treatment agent.
[Claim 3] The production method according to claim 1 or 2, wherein the metal member is a processed/molded member.

Ref No. P0222933-PCT-ZZ (27/30)
[Claim 4] The production method according to claim 1 or 2, wherein the water-based surface treatment agent does not contain fluoride ions or contains fluoride ions as an unavoidable impurity.
[Claim 5] The production method according to claim 1 or 2, wherein the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound.
[Claim 6] The production method according to claim 1 or 2, wherein when a number of equivalents of a metal element in the metal compound (B) is taken to be EB and a number of equivalents of a metal coordination site in the chelating agent (C) is taken to be EC, EB relative to EC is within a range of 0.50 to 4.00.
[Claim 7] The production method according to claim 1 or 2, wherein the aqueous resin (A) is a resin that includes two or more types of groups selected from the group consisting of a primary amino group, a secondary amino group, a carboxyl group, a hydroxy group, a urethane group, and a ureido group.
[Claim 8] The production method according to claim 1 or 2, wherein the aqueous resin (A) includes one or more selected from the group consisting of an acrylic-modified epoxy resin, a carbon-carbon unsaturated bond-containing polyurethane resin, and an aromatic ring structure-containing polyurethane resin.
[Claim 9] The production method according to claim 1 or 2, wherein the chelating agent (C) includes one or more selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, 1-hydroxyethane-1,1-diphosphonic acid, and 2-phosphonobutane-1,2,4 butanetricarboxylic acid.
[Claim 10] A water-based surface treatment agent that is for a processed/molded metal member and that comprises an aqueous resin (A), a

Ref No. P0222933-PCT-ZZ (28/30) metal compound (B), a chelating agent (C), and water, wherein the aqueous resin (A) includes one or more selected from the group consisting of an aqueous epoxy resin, an aqueous polyurethane resin, and an aqueous silicone oligomer, the metal compound (B) includes one or more metal elements selected from the group consisting of magnesium, aluminum, titanium, and zirconium, the chelating agent (C) is one or more selected from the group consisting of an alkanolamine, a hydroxy group-containing organic phosphonic acid compound, and a carboxyl group-containing organic phosphonic acid compound, and an amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 6 mass% relative to total mass of the water based surface treatment agent.
[Claim 11] The water-based surface treatment agent according to claim 10, wherein the amount of solid content in the water-based surface treatment agent is within a range of 0.01 mass% to 3 mass% relative to total mass of the water based surface treatment agent.

Ref No. P0222933-PCT-ZZ (29/30)