Chromium-free substrate treatment agent

Abstract

The invention discloses a chromium-free substrate treating agent capable of improving corrosion resistance and chemical resistance of metal. A chromium-free substrate treatment agent comprises an organic phosphonic acid resin, a phosphoric acid compound, a complex fluoride and a manganese compound, the organic phosphonic acid resin is a copolymer comprising a chain segment derived from a carboxyl group-containing acrylic monomer and a chain segment derived from a phosphonic acid group-containing monomer, and the phosphonic acid group-containing monomer is vinyl phosphonic acid or phosphonic acid group-containing acrylate.

Description

Technical Field

[0001] The present invention relates to a chromium-free substrate treatment agent. Background Art

[0002] Conventionally, in order to improve the corrosion resistance of metals, a method of surface-treating metals with a substrate treatment agent containing a chromium compound such as a hexavalent chromium compound or a trivalent chromium compound has been known.

[0003] However, according to recent trends in environmental regulations, the use of a substrate treatment agent containing a chromium compound may be restricted. Therefore, various chromium-free substrate treatment agents that do not contain a chromium compound have been developed. For example, as a chromium-free metal surface treatment agent used in metal materials such as galvanized steel sheet materials and aluminum-based materials, a surface treatment agent containing a zirconium compound, a vanadium compound, a metal fluorocomplex compound, an organic phosphorus compound and an inorganic phosphorus compound, and a high acid value resin is known (see Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-208874 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] The technique disclosed in Patent Document 1 not only improves the adhesion to metal materials, but also improves the adhesion to coatings and corrosion resistance. However, there is still room for further improvement, particularly in terms of corrosion resistance and chemical resistance at the end faces of metal materials.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to provide a chromium-free substrate treatment agent capable of improving the corrosion resistance and chemical resistance of metals.

[0010] Means for Solving the Problems

[0011] (1) A chromium-free substrate treatment agent comprising an organic phosphonic acid resin, a phosphoric acid compound, a complex fluoride, and a manganese compound, wherein the organic phosphonic acid resin is a copolymer comprising a segment derived from a carboxyl group-containing acrylic monomer and a segment derived from a phosphonic acid group-containing monomer, and the phosphonic acid group-containing monomer is vinyl phosphonic acid or a phosphonic acid group-containing acrylate.

[0012] (2) The chromium-free substrate treatment agent according to (1), further comprising a vanadium compound.

[0013] (3) The chromium-free substrate treatment agent according to (1) or (2), wherein the complex fluoride is fluosilicic acid.

[0014] (4) The chromium-free substrate treatment agent according to any one of (1) to (3), wherein the content ratio of the manganese element of the manganese compound to the organophosphonic acid resin (manganese / organophosphonic acid resin) is 0.05 to 2.0.

[0015] (5) A substrate treatment film formed by curing the chromium-free substrate treatment agent according to any one of (1) to (4).

[0016] Advantages of the Invention

[0017] According to the present invention, a chromium-free substrate treatment agent capable of improving the corrosion resistance and chemical resistance of metals can be provided. Detailed Embodiments

[0018] Hereinafter, the substrate treatment agent of the embodiment of the present invention will be described. The present invention is not limited to the description of the following embodiments.

[0019] <Chromium-free Substrate Treatment Agent>

[0020] The chromium-free substrate treatment agent of the present embodiment (hereinafter, sometimes referred to as "substrate treatment agent") contains an organophosphonic acid resin, a phosphoric acid compound, a complex fluoride, and a manganese compound. It is further preferably contains a vanadium compound.

[0021] The substrate treatment agent of the present embodiment preferably does not contain trivalent and hexavalent chromium. The forms of trivalent and hexavalent chromium are not particularly limited to metallic chromium, chromium ions, chromium compounds, etc.

[0022] (Organophosphonic Acid Resin)

[0023] The organophosphonic acid resin is a copolymer containing a segment derived from a carboxyl group-containing acrylic monomer and a segment derived from a phosphonic acid group-containing monomer. The segment derived from the carboxyl group-containing acrylic monomer reacts with the coating film formed on the film formed by the substrate treatment agent to improve the adhesion. The segment derived from the phosphonic acid group-containing monomer reacts with the surface of the metal substrate coated with the substrate treatment agent to improve the adhesion. In addition, the chemical resistance is improved by the crosslinking effect of other components. The segment derived from the carboxyl group-containing acrylic monomer may be a monomer segment in which the functional group of an acrylic monomer having a functional group other than a carboxyl group is modified to a carboxyl group. The segment derived from the phosphonic acid group-containing monomer may be a monomer segment in which the functional group of a monomer having a functional group other than a phosphonic acid group is modified to a phosphonic acid group.

[0024] The carboxyl group-containing acrylic monomer is not particularly limited, and for example, (meth)acrylic monomers are preferably used.

[0025] The phosphonic acid group-containing monomer is vinylphosphonic acid, vinylidene-1,1-diphosphonic acid, or a phosphonic acid group-containing acrylate.

[0026] The content ratio of the segment derived from the phosphonic acid group-containing monomer in the organophosphonic acid resin is preferably 20 mol% or more and 95 mol% or less with respect to the total of all segments constituting the organophosphonic acid resin. When the content ratio of the segment derived from the phosphonic acid monomer is 20 mol% or more, the phosphonic acid group binds sufficiently to the surface of the metal substrate, improving the adhesion and corrosion resistance. On the other hand, when it exceeds 95 mol%, the binding to the coating film is insufficient, reducing the adhesion and corrosion resistance.

[0027] The content ratio of the segment derived from the carboxyl group-containing acrylic monomer in the organophosphonic acid resin is preferably 5 mol% or more and 80 mol% or less with respect to the total of all segments constituting the organophosphonic acid resin. By making the content ratio of the segment derived from the carboxyl group-containing acrylic monomer 5 mol% or more, the acrylic group binds sufficiently to the coating film, improving the adhesion and corrosion resistance. On the other hand, when it exceeds 80 mol%, the binding to the surface of the metal substrate is insufficient, reducing the adhesion and corrosion resistance.

[0028] The organophosphonic acid resin may contain other segments derived from monomers other than the above. The monomers other than the above are not particularly limited, and examples include hydroxyl group-containing acrylic monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc., acrylate monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, 1-methylethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, phenyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, etc., non-acrylic monomers such as styrene, α-methylstyrene, tert-butylstyrene, vinylnaphthalene, acrylonitrile, methacrylonitrile, ethylene, propylene, vinyl acetate, vinyl propionate, butadiene, isoprene, etc., and (meth)acrylamide-based compounds such as N-hydroxyethyl (meth)acrylamide, N-hydroxypropyl (meth)acrylamide, N,N'-methylenebisacrylamide. The content ratio of the above other segments in the organophosphonic acid resin is preferably 30 mol% or less, more preferably 10 mol% or less, and most preferably 0 mol%. The organophosphonic acid resin is more preferably a two-component system of a carboxyl group-containing acrylic monomer and a phosphonic acid group-containing monomer, and does not contain segments derived from other monomers. When the above other segments in the organophosphonic acid resin are 30 mol% or less, it binds sufficiently to the surface of the metal substrate and the coating film, improving the adhesion and corrosion resistance.

[0029] The organophosphonic acid resin can be prepared by solution polymerization of a monomer mixture containing the above monomers. As the molecular weight of the organophosphorus resin, the weight-average molecular weight is preferably 10,000 to 100,000. By having a weight-average molecular weight of 10,000 or more, the adhesion and corrosion resistance are improved. By having a weight-average molecular weight of 100,000 or less, it can be compounded without crosslinking and increasing viscosity with other metal components. The weight-average molecular weight can be measured by gel permeation chromatography. As the organophosphonic acid resin, commercially available products can be used. There is no particular limitation for commercially available products, and for example, ADDIBOND (registered trademark) series manufactured by Solvay can be cited.

[0030] By making the content of the organophosphonic acid resin 2% by mass or more based on the total solid content of the surface treatment agent, the adhesion of the metal and the corrosion resistance of the end face part can be improved. By making the content of the organophosphonic acid resin 30% by mass or less, it can be compounded evenly with other components, and high corrosion resistance, adhesion, and chemical resistance can be exhibited.

[0031] (Phosphoric acid compound)

[0032] The phosphoric acid compound includes compounds having a phosphoric acid group such as orthophosphoric acid (phosphoric acid), condensed phosphoric acid, and their salts. By containing a phosphoric acid compound in the substrate treatment agent, the corrosion resistance of the metal can be improved. The above-mentioned condensed phosphoric acid is a general term for linear high-molecular phosphoric acid generated by dehydration condensation of orthophosphoric acid, and for example, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, metaphosphoric acid, tetrametaphosphoric acid, superphosphoric acid, etc. can be cited. There is no particular limitation for the salt of the above-mentioned phosphoric acid compound, and sodium salt, potassium salt, ammonium salt, etc. can be cited.

[0033] The content of the phosphoric acid compound is preferably 30% by mass to 70% by mass based on the total solid content of the substrate treatment agent. By making the content of the phosphoric acid compound 30% by mass or more, the corrosion resistance of the metal can be improved. By making the content of the phosphoric acid compound 70% by mass or less, it can be compounded evenly with other components, and high corrosion resistance, adhesion, and chemical resistance can be exhibited.

[0034] (Complex fluoride)

[0035] By containing a complex fluoride in the substrate treatment agent, the adhesion between the film formed by the substrate treatment agent and the metal is improved. As the complex fluoride, for example, fluorosilicic acid, zinc fluorosilicate, magnesium fluorosilicate, nickel fluorosilicate, iron fluorosilicate, calcium fluorosilicate, etc., fluorozirconic acid (H2ZrF6), ammonium hexafluorozirconate ((NH4)2ZrF6), etc., zirconium fluorides, fluorotitanic acid (H2TiF6), ammonium hexafluorotitanate ((NH4)2TiF6), etc., titanium fluorides, etc. can be cited. From the aspect of better adhesion, the complex fluoride is preferably fluorosilicic acid.

[0036] The content of the complex fluoride is preferably 5.0 to 20% by mass relative to the total solid content of the base treatment agent. When the content of the complex fluoride is 5.0% by mass or more, the adhesion between the film and the metal becomes good. By making the content of the complex fluoride 20% by mass or less, it is possible to balance the blending with other components and exhibit high corrosion resistance, adhesion, and chemical resistance.

[0037] (Manganese compound)

[0038] By including a manganese compound in the base treatment agent, the chemical resistance (acid resistance and alkali resistance) of the metal is improved. Examples of the manganese compound include organic acid salts such as manganese acetate, manganese benzoate, manganese lactate, manganese formate, and manganese tartrate, halides such as manganese chloride and manganese bromide, inorganic acid salts such as manganese nitrate, manganese carbonate, and manganese sulfate, alcoholates such as methoxymanganese; manganese(II) acetylacetonate, manganese(III) acetylacetonate, manganese dioxide, manganese oxide, etc.

[0039] By making the content of manganese element derived from the manganese compound 1% by mass or more relative to the total solid content of the surface treatment agent, the chemical resistance of the metal can be improved. By making the content of manganese element derived from the manganese compound 15% by mass or less, it is possible to balance the blending with other components and exhibit high corrosion resistance, adhesion, and chemical resistance.

[0040] The mass ratio of manganese element of the manganese compound to the organic phosphonic acid resin (manganese / organic phosphonic acid resin) is preferably 0.05 to 2.0. When manganese / organic phosphonic acid resin is 0.05 or more, a sufficient amount of manganese to exhibit chemical resistance can be ensured, so the chemical resistance of the metal can be preferably improved. When manganese / organic phosphonic acid resin is 2.0 or less, the functional groups of the organic phosphine resin are not consumed in the binding with manganese, and a sufficient amount of organic phosphonic acid resin can be ensured, so the adhesion and corrosion resistance can be preferably improved. From the above viewpoints, manganese / organic phosphonic acid resin is more preferably 0.1 to 1.0.

[0041] (Vanadium compound)

[0042] The vanadium compound acts as a rust inhibitor (inhibitor) by being included in the base treatment agent, thereby improving the corrosion resistance of the metal. There is no particular limitation on the vanadium compound, and examples thereof include vanadium pentoxide, metavanadic acid, ammonium metavanadate, sodium metavanadate, vanadyl trichloride, vanadyl sulfate, vanadyl oxalate, magnesium vanadate, vanadium trioxide, vanadium trichloride, vanadium dioxide, vanadyl acetylacetonate, vanadium acetylacetonate, etc.

[0043] The content of the vanadium compound is preferably 5.0 to 20% by mass relative to the total solid content of the substrate treatment agent. By the content of the vanadium compound being 5.0% by mass or more, the corrosion resistance of the metal is improved. By the content of the vanadium compound being 20% by mass or less, it is possible to be balanced with other components, and high corrosion resistance, adhesion, and chemical resistance can be exhibited.

[0044] (Other components)

[0045] From the viewpoint of improving the stability of the treatment liquid, the substrate treatment agent of the present embodiment may contain a chelating agent. As the chelating agent applicable to the substrate treatment agent of the present embodiment, for example, at least one selected from the group consisting of phosphonic acid-based chelating agents, aminocarboxylic acid-type chelating agents, and carboxyethyl-based chelating agents can be cited.

[0046] Here, as the phosphonic acid-based chelating agent, for example, HEDP, NTMP, PBTC, EDTMP, etc. can be cited. As the aminocarboxylic acid-type chelating agent, EDTA, NTA, DTPA, HEDTA, TTHA, PDTA, DPTA-OH, HIDA, DHEG, GEDTA, CMGA, EDDS, etc. can be cited. As the carboxyethyl-based chelating agent, for example, citric acid, structural isomers of citric acid, adipic acid, aminohexanoic acid, etc. can be cited.

[0047] The total content of the chelating agent contained in the substrate treatment agent of the present embodiment is preferably 1000 to 15000 mass ppm, more preferably 1500 to 12000 mass ppm. When the total content of the chelating agent is less than 1000 mass ppm, the chelating stabilization effect of the metal components in the aqueous solution becomes insufficient. On the other hand, when the total content of the chelating agent exceeds 15000 mass ppm, the chelating stabilization effect saturates, and thus it becomes uneconomical.

[0048] In the substrate treatment agent of the present embodiment, other components can be further contained within a range that does not hinder the above functions. As the other components, known components contained in substrate treatment agents such as crosslinking agents, rust inhibitors, leveling agents, defoaming agents, and pH adjusters can be cited.

[0049] <Metal substrate>

[0050] The metal substrate, which is the object to be substrate-treated using the substrate treatment agent of the present embodiment, is not particularly limited. For example, as iron-based materials, metal steels such as cold-rolled steel, hot-rolled steel, stainless steel, electro-galvanized steel, hot-dip galvanized steel, zinc-aluminum alloy-coated steel, zinc-iron alloy-coated steel, zinc-magnesium alloy-coated steel, zinc-aluminum-magnesium alloy-coated steel, aluminum-coated steel, aluminum-silicon alloy-coated steel, tin-coated steel, lead-tin-coated steel, chromium-coated steel, Ni-coated steel, etc. can be cited. As aluminum-based materials, metal materials such as pure aluminum and various aluminum alloys can be cited. The shape of the metal substrate is not particularly limited, and for example, a plate shape, etc. can be cited.

[0051] <Substrate treatment method>

[0052] As a substrate treatment method using the substrate treatment agent of the present embodiment, for example, it includes a coating step of coating the substrate treatment agent on the surface of the metal substrate and a sintering step of sintering and curing the substrate treatment agent coated on the metal substrate.

[0053] In the coating step, the method of coating the substrate treatment agent on the surface of the metal substrate is not particularly limited. For example, methods such as roll coating, bar coating, spray treatment, dipping treatment, etc. can be cited. It should be noted that before the coating step, the surface of the metal substrate can be subjected to degreasing treatment, pickling, and etching treatment as needed.

[0054] In the sintering step, after the coating step, the substrate treatment agent coated on the metal substrate is sintered. The method of the above sintering is not particularly limited. For example, after coating the substrate treatment agent on the surface of the metal substrate, the upper layer can be painted in a state where the substrate treatment agent is not cured, and then sintered.

[0055] <Substrate treatment film>

[0056] A film formed by the above substrate treatment agent (hereinafter, sometimes referred to as "film") is formed on the surface of the above metal substrate. The film thickness of the film is not particularly limited, and is preferably 0.01 to 1.0 μm. The weight of the film is not particularly limited, and is preferably 0.01 to 1.0 g / m 2 . It is preferable to form a coating film on the upper layer of the film. This is because the substrate treatment agent of the present embodiment can obtain preferable adhesion with the coating film. The coating material for forming the coating film is not particularly limited, and a coating material for single coating can be used, or a primer and a topcoat can be used.

[0057] Examples

[0058] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples.

[0059] <Preparation of substrate treatment agent>

[0060] [Examples 1 to 41, Comparative Examples 1 to 6]

[0061] Mix and stir an organophosphonic acid resin, a resin (comparative example), a phosphoric acid compound, a complex fluoride, a manganese compound, a vanadium compound, a chelating compound, and ion-exchanged water to make the solid content of the substrate treatment agent 2% by mass so as to obtain the contents described in Tables 1 to 4 below. The blending amounts of the respective components described in Tables 1 to 4 represent the solid content amounts (parts by mass).

[0062] The details of the types of raw materials described in Tables 1 to 4 are as follows.

[0063] (A1 to A3: organophosphonic acid resins, A4 to A5: resins (comparative examples))

[0064] A1: ADDIBOND (registered trademark) 021 (organophosphonic acid resin (non-volatile content (NV): 20%), copolymer of vinylphosphonic acid and acrylic acid, molar ratio of vinylphosphonic acid: 30%, weight average molecular weight: 30,000 to 90,000, manufactured by Solvay)

[0065] A2: ADDIBOND (registered trademark) 829 (organophosphonic acid resin (non-volatile content (NV): 40%), manufactured by Solvay)

[0066] A3: Jurymer AC-10L (polyacrylic acid (non-volatile content (NV): 40%), manufactured by Toagosei Co., Ltd.)

[0067] A4: Polyvinylphosphonic acid (non-volatile content (NV): 100%, manufactured by Sigma-Aldrich)

[0068] (B1 to B3: phosphoric acid compounds)

[0069] B1: Phosphoric acid

[0070] B2: Pyrophosphoric acid

[0071] B3: Polyphosphoric acid

[0072] (C1 to C4: complex fluorides)

[0073] C1: Fluorosilicic acid

[0074] C2: Fluorotitanic acid (manufactured by Morita Chemical Industries Co., Ltd.)

[0075] C3: Fluorozirconic acid (manufactured by Morita Chemical Industries Co., Ltd.)

[0076] C4: Aluminum fluoride

[0077] (D1 to D2: Manganese compounds)

[0078] D1: Manganese nitrate

[0079] D2: Manganese carbonate

[0080] (E1 to E6: Vanadium compounds)

[0081] E1: Vanadyl sulfate

[0082] E2: Ammonium metavanadate

[0083] E3: Sodium metavanadate

[0084] E4: Vanadyl oxalate

[0085] E5: Vanadium pentoxide

[0086] E6: Vanadyl acetylacetonate (VO(C5H7O2)2) (NACEM Vanadyl, manufactured by Nippon Chemical Industry Co., Ltd.)

[0087] (F1 to F2: Chelating agents)

[0088] F1: 1-Hydroxyethane-1,1-diphosphonic acid (HEDP)

[0089] F2: 2-Phosphonobutane-1,2,4-tricarboxylic acid (PBTC)

[0090] [Table 1]

[0091]

[0092] [Table 2]

[0093]

[0094] [Table 3]

[0095]

[0096] [Table 4]

[0097]

[0098] [Fabrication of test plates]<

[0099] Using the substrate treating agents shown in Tables 1 to 4, perform substrate treatment on the 55% molten aluminum-zinc alloy plated steel sheet (substrate shown in Tables 1 to 4: GL) or the molten galvanized steel sheet (substrate shown in Table 2: GI), respectively. The substrate treatment is carried out according to the following steps.

[0100] (Degreasing and surface treatment)

[0101] Degrease by spraying with an alkaline degreaser (Surfcleaner 155, manufactured by Nipponpaint SurfChemicals) at 60°C for 10 seconds, wash with water, and then dry at 80°C. Next, after adjusting the solid component concentration of the surface treatment agents prepared in the examples and comparative examples, coat them on the degreased steel plate using a bar coater (#3 brush), and dry using a hot air circulation oven so that the metal substrate reaches a temperature of 80°C to produce test plates with a chemical conversion film formed thereon.

[0102] (Resin layer formation)

[0103] After coating a commercially available PCM primer paint (Flekicoat 600, manufactured by Nipponpaint Industrial Coatings) (dry film thickness: 5.0 μm), sinter at 200°C. Then, further coat a PCM topcoat paint (polyester-based paint, Flekicoat 5030, manufactured by Nipponpaint Industrial Coatings) (dry film thickness: 15 μm) on the sintered surface and sinter at 225°C to produce painted steel plates. Cut out test pieces from each of the painted steel plates thus produced as test plates. Conduct the following evaluations using the test plates obtained as described above.

[0104] <Evaluation>

[0105] [Compound cycle test (corrosion resistance)]

[0106] Make incisions reaching the metal substrate on the coating films of each of the test plates prepared above using a cutter, and conduct 150 cycles of the compound cycle test (CCT) specified in JIS H8502 (JASO M609-91). Then, measure the maximum value of the coating film swelling width starting from the damaged part and the average value of the coating film swelling width starting from the end face part of the test piece, and conduct evaluations according to the following criteria. Consider evaluations of 3.5 or above as passing. The results are shown in Tables 1 to 4. Note that the measurement of the above average value means visually selecting the part with the average swelling width in the entire coating film swelling part starting from the end face part of the test piece and measuring the coating film swelling width of that part.

[0107] (Evaluation criteria: maximum value of coating film swelling width starting from the damaged part)

[0108] 5: Less than 1 mm

[0109] 4.5: 1 mm or more and less than 2 mm

[0110] 4: 2 mm or more and less than 3 mm

[0111] 3.5: 3 mm or more and less than 4 mm

[0112] 3: Above 4 mm and less than 5 mm

[0113] 2.5: Above 5 mm and less than 6 mm

[0114] 2: Above 6 mm and less than 7 mm

[0115] 1.5: Above 7 and less than 8 mm

[0116] 1: Above 8 mm

[0117] (Evaluation criterion: Average value of the film swelling amplitude measured from the end face of the test piece)

[0118] 5: Less than 4 mm

[0119] 4.5: Above 4 mm and less than 6 mm

[0120] 4: Above 6 mm and less than 8 mm

[0121] 3.5: Above 8 mm and less than 10 mm

[0122] 3: Above 10 mm and less than 12 mm

[0123] 2.5: Above 12 mm and less than 14 mm

[0124] 2: Above 14 mm and less than 16 mm

[0125] 1.5: Above 16 mm and less than 18 mm

[0126] 1: Above 18 mm

[0127] [Sealing property after one bending]

[0128] For each of the test plates fabricated above, clamp the spacer according to the test method specified in JIS G3312, perform 2T bending (bending by 180 degrees) at 20 °C, and conduct the tape peeling test on the bent portion. Then, visually evaluate the film peeling state after the test according to the following criteria. An evaluation of 3.5 or higher is considered qualified. The results are shown in Tables 1 to 4.

[0129] 5: No peeling

[0130] 4.5: 1 - 10% peeling

[0131] 4: 11 - 20% peeling

[0132] 3.5: 21 - 30% peeling

[0133] 3: 31 - 40% peeling

[0134] 2.5: 41 - 50% peeling

[0135] 2: 51 - 60% delamination

[0136] 1.5: 61 - 70% delamination

[0137] 1: 71 - 80% delamination

[0138] 0.5: 81 - 90% delamination

[0139] 0: 91 - 100% delamination

[0140] [Bending secondary sealing property]

[0141] After immersing the test plate in boiling water for 2 hours, leave it indoors for 24 hours, and evaluate it according to the same criteria under the condition of 2TT as in the case of bending once sealing property. Consider 3.5 or above as qualified, and the results are shown in Tables 1 - 4.

[0142] [Alkali resistance (chemical resistance)]

[0143] For each of the above - prepared test plates, evaluate the alkali resistance according to the test method specified in ASTM D714 - 56 using the following method. After immersing each of the prepared test plates in a 5 mass% sodium hydroxide aqueous solution at room temperature for 24 hours, visually evaluate the size and generation density of the bubbles generated on the evaluation surface according to the following criteria. Consider 3.5 or above as qualified. The results are shown in Tables 1 - 4.

[0144] (Evaluation criteria: Alkali resistance (chemical resistance))

[0145] 5: No bubbles

[0146] 4.5: The size of one bubble is less than 0.3 mm and the generation density is VF or F.

[0147] 4: The size of one bubble is 0.3 mm or more and less than 0.6 mm, and the generation density is VF or F.

[0148] 3.5: The size of one bubble is less than 0.6 mm and the generation density is FM.

[0149] 3: The size of one bubble is less than 0.6 mm and the generation density is M. Or, the size of one bubble is 0.6 mm or more and less than 1.2 mm, and the generation density is F or FM.

[0150] 2.5: The size of one bubble is less than 0.6 mm and the generation density is MD. Or, the size of one bubble is 0.6 mm or more and less than 1.2 mm and the generation density is FM or M. Or, the size of one bubble is 1.2 mm or more and less than 1.8 mm and the generation density is VF or F.

[0151] 2: The size of a single bubble is 0.6 mm or more and less than 1.2 mm, and the generation density is M or MD. Alternatively, the size of a single bubble is 1.2 mm or more and less than 1.8 mm, and the generation density is F or FM.

[0152] 1.5: The size of a single bubble is 1.2 mm or more and less than 1.8 mm and the generation density is M or MD.

[0153] 1: The size of a single bubble is 1.8 mm or more. Alternatively, regardless of the size of the bubble, the generation density is D.

[0154] It should be noted that the meanings of the notations used for the generation density are as follows.

[0155] VF: The number of bubbles generated is extremely small.

[0156] F: The number of bubbles generated is small.

[0157] FM: The number of bubbles generated is at an intermediate level between F and M.

[0158] M: The number of bubbles generated is large.

[0159] MD: The number of bubbles generated is at an intermediate level between M and D.

[0160] D: The number of bubbles generated is extremely large.

[0161] [Acid resistance (chemical resistance)]

[0162] After immersing each of the above-prepared test plates in a 5 mass% hydrochloric acid aqueous solution at room temperature for 24 hours, visually observe the size and generation density of the bubbles generated on the evaluation surface, and evaluate according to the same criteria as in the alkali resistance test. An evaluation of 3.5 or more is considered qualified. The results are shown in Tables 1 to 4.

[0163] From the results in Tables 1 to 4, it can be seen that the substrate treatment agents of the respective examples have higher metal corrosion resistance, adhesion, and chemical resistance compared to the substrate treatment agents of the respective comparative examples. For example, compared to the substrate treatment agents of Comparative Example 1, Comparative Example 5, and Comparative Example 6 that do not contain an organophosphonic acid resin, the substrate treatment agents of the respective examples have higher metal corrosion resistance, adhesion, and chemical resistance (alkali resistance). In addition, compared to the substrate treatment agent of Comparative Example 4 that does not contain a manganese compound, the substrate treatment agents of the respective examples have higher metal chemical resistance.

Claims

1. A chromium-free substrate treatment agent, which comprises an organic phosphonic acid resin, a phosphoric acid compound, a complex fluoride, and a manganese compound, The organic phosphonic acid resin is a copolymer comprising a segment derived from a carboxyl group-containing acrylic monomer and a segment derived from a phosphonic acid group-containing monomer, The phosphonic acid group-containing monomer is vinyl phosphonic acid or a phosphonic acid group-containing acrylate.

2. The chromium-free substrate treatment agent according to claim 1, which further comprises a vanadium compound.

3. The chromium-free substrate treatment agent according to claim 1 or 2, wherein, The complex fluoride is fluorosilicic acid.

4. The chromium-free substrate treating agent according to claim 1 or 2, wherein, The content ratio of manganese element of the manganese compound relative to the organic phosphonic acid resin, i.e., manganese / organic phosphonic acid resin, is 0.05 to 2.

0.

5. A substrate treatment film cured from the chromium-free substrate treatment agent according to claim 1 or 2.

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