Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/60—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
  • C23C22/62—Treatment of iron or alloys based thereon
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
  • C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00

Definitions

• the present invention relates to a metal surface treatment agent.
• Zinc phosphate treatment and zirconium-based conversion coatings have been known as technologies for imparting corrosion resistance to metal substrates such as steel.
• Zinc phosphate treatment is used as a conversion coating for paint bases, but because its coating components contain phosphorus, an element that contributes to eutrophication, and nickel, which may be carcinogenic, its use has tended to be avoided in recent years due to concerns about environmental protection and its impact on the human body.
• Zirconium-based chemical conversion coating is a technology that has traditionally been applied to aluminum-based materials, and there is still room for improvement in terms of technology that can impart high corrosion resistance to steel materials.
• Patent Document 1 The technology described in Patent Document 1 is related to surface-treated steel sheets, and the surface treatment film contains an acrylic resin emulsion.
• the main component of the surface treatment film contains a resin component such as an acrylic resin emulsion, it is difficult to raise the material temperature (PMT) during baking to a high temperature exceeding 200°C, for example, and the current situation is that sufficient heat resistance and durability of the coating film cannot be obtained, and sufficient corrosion resistance after painting cannot be obtained.
• PMT material temperature
• the present invention was made in consideration of the above, and aims to provide a metal surface treatment agent that can be baked at high temperatures and can impart high corrosion resistance to metal substrates.
• the present invention relates to a metal surface treatment agent that contains a silicate compound (A), an alkali metal salt (B) that is other than a silicate compound, a vanadium compound, and a zirconium compound, a vanadium compound (C), a zirconium compound (D), and water, and that has a silicon element content of 10 mass% or more based on the total solid content of the metal surface treatment agent.
• the present invention provides a metal surface treatment agent that can be baked at high temperatures and can impart high corrosion resistance to metal substrates.
• the following describes the metal surface treatment agent according to an embodiment of the present invention.
• the present invention is not limited to the description of the following embodiment.
• the metal surface treatment agent according to the present embodiment contains a silicic acid compound (A), an alkali metal salt (B) other than a silicic acid compound, a vanadium compound, and a zirconium compound, a vanadium compound (C), a zirconium compound (D), and water. It is also preferable that the metal surface treatment agent contains a chelating agent (E).
• the silicic acid compound (A) is the main component of the film formed by the metal surface treatment agent. By making the silicic acid compound (A), which is an inorganic compound, the main component of the film, the film can be baked at high temperatures.
• Specific examples of the silicic acid compound (A) include alkali metal silicate, colloidal silica, alkyl silicate compound, hydrolysis product of alkyl silicate compound, condensation polymerization product of alkyl silicate compound, etc., but the silicic acid compound (A) is preferably an alkali metal silicate from the viewpoint of corrosion resistance.
• silicate of the alkali metal examples include alkali metal salts of orthosilicic acid such as lithium orthosilicate, sodium orthosilicate, potassium orthosilicate, etc.; alkali metal salts of metasilicic acid such as lithium metasilicate, sodium metasilicate, potassium metasilicate, etc.; and the like.
• alkyl silicate compound examples include methyl silicate, ethyl silicate, etc.
• the silicon element content of the metal surface treatment agent of this embodiment is 10 mass% or more relative to the total solid content.
• the silicon element content is preferably 20 mass% or more and 40 mass% or less.
• PMT material target temperature
• the alkali metal salt (B) is an alkali metal salt other than a silicate compound, a vanadium compound, and a zirconium compound, and acts as a crosslinking agent.
• the alkali metal salt (B) is contained in the metal surface treatment agent, and thereby the barrier property of the formed film against water and corrosion factors (chloride ions, etc.) is improved, and as a result, the corrosion resistance imparted to the metal substrate can be improved.
• alkali metal salt (B) examples include, but are not limited to, carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; hydrogen carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate; hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; nitrites such as lithium nitrite, sodium nitrite, and potassium nitrite; and the like.
• the vanadium compound (C) acts as a rust inhibitor when added to a metal surface treatment agent.
• the vanadium compound (C) is not particularly limited, but examples thereof include vanadium pentoxide, metavanadic acid, ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride, vanadyl sulfate, magnesium vanadate, vanadium trioxide, vanadium trichloride, vanadium dioxide, vanadyl acetylacetonate, and vanadium acetylacetonate.
• the vanadium element content is preferably 0.1 to 10 mass% relative to the total solid content of the metal surface treatment agent of this embodiment.
• the vanadium element content is more preferably 0.5 to 5 mass%. If the vanadium element content is less than 0.1 mass%, sufficient rust prevention properties cannot be obtained. If the vanadium element content exceeds 10 mass%, the stability and corrosion resistance of the metal surface treatment agent decrease.
• the zirconium compound (D) acts as a crosslinking agent to improve the barrier properties of the formed coating against water and corrosion factors (chloride ions, etc.), resulting in improved corrosion resistance.
• the zirconium compound (D) is not particularly limited, but examples thereof include zirconium carbonate salts such as ammonium zirconium carbonate and potassium zirconium carbonate , alkali metal fluorozirconates such as K2ZrF6 , zirconium hydrofluoric acid ( H2ZrF6 ), ammonium zirconium fluoride (( NH4 ) 2ZrF6 ), zirconium fluoride, zirconium nitrate, zirconium oxide, and the like.
• the zirconium element content is preferably 0.1 to 10 mass% relative to the total solid content of the metal surface treatment agent of this embodiment. With the zirconium element content in this range, the stability and corrosion resistance of the metal surface treatment agent are improved.
• the zirconium element content is more preferably 0.5 to 5 mass%. If the zirconium element content is less than 0.1 mass%, the effect as a sufficient cross-linking agent is not obtained. If the zirconium element content exceeds 10 mass%, the stability and corrosion resistance of the treatment agent are reduced.
• the molar ratio (M/Si) of the alkali metal element (M) to the silicon element (Si) contained in the solid content of the metal surface treatment agent of this embodiment is preferably 0.5 to 1.2.
• the molar ratio (M/Si) is more preferably 0.6 to 1.1. If the molar ratio (M/Si) is less than 0.5, the corrosion resistance decreases. If the molar ratio (M/Si) exceeds 1.2, the stability of the metal surface treatment agent decreases.
• the alkali metal element (M) includes alkali metal elements derived from silicate compounds (A), vanadium compounds (C), zirconium compounds (D), or other compounds other than the alkali metal salt (B).
• the chelating agent (E) is added to the metal surface treatment agent to stabilize zirconium in the metal surface treatment agent.
• the chelating agent (E) is not particularly limited, but examples thereof include hydroxycarboxylic acids such as lactic acid, malic acid, tartaric acid, citric acid, and gluconic acid, ethylenediaminetetraacetic acid (EDTA), organic phosphorus compounds such as 1-hydroxyethane-1,1-diphosphonic acid (HEDP), hydroxyamines such as triethanolamine (TEA), and salts of the above compounds.
• the chelating agent (E) may contain an organic phosphorus compound such as the above-mentioned HEDP, but from the viewpoint of reducing the environmental impact due to eutrophication, it is preferable that the metal surface treatment agent according to this embodiment does not contain inorganic phosphorus compounds such as phosphoric acids such as orthophosphoric acid (H3PO4 ) , pyrophosphoric acid ( H4P2O7 ), metaphosphoric acid ( HPO3 ), and phosphates such as ammonium phosphate and sodium phosphate.
• phosphoric acids such as orthophosphoric acid (H3PO4 )
• metaphosphoric acid ( HPO3 ) metaphosphoric acid
• phosphates such as ammonium phosphate and sodium phosphate.
• the metal surface treatment agent of this embodiment contains water as a component other than the above.
• the metal surface treatment agent may further contain other components within a range that does not inhibit the above functions.
• the other components include resin components such as acrylic resins, urethane resins, epoxy resins, olefin resins such as ethylene acrylic copolymers, polyester resins, polyolefin resins, alkyd resins, and polycarbonate resins.
• the solid content of the resin components relative to the total solid content of the metal surface treatment agent is preferably 10% by mass or less, more preferably 5% by mass or less. This allows the metal surface treatment agent to be preferably baked at high temperatures.
• other components other than the above include known components contained in surface treatment agents such as crosslinkers, rust inhibitors, leveling agents, defoamers, and pH adjusters.
• the solid content of the metal surface treatment agent of the present embodiment is preferably 0.1 to 30 mass %, and more preferably 1.0 to 25 mass %.
• the metal substrate to be surface-treated with the metal surface treatment agent of the present embodiment is not particularly limited, and examples thereof include metal steel materials such as cold-rolled steel, hot-rolled steel, stainless steel, electrogalvanized steel, hot-dip galvanized steel, zinc-aluminum alloy-based plated steel, zinc-iron alloy-based plated steel, zinc-magnesium alloy-based plated steel, zinc-aluminum-magnesium alloy-based plated steel, aluminum-based plated steel, aluminum-silicon alloy-based plated steel, tin-based plated steel, lead-tin-based plated steel, chromium-based plated steel, and Ni-based plated steel.
• the shape of the metal substrate is not particularly limited, and examples thereof include a plate shape.
• the metal surface treatment agent of this embodiment is a so-called coating-type metal surface treatment agent.
• the coating-type metal surface treatment agent is used in a method in which the surface treatment agent is applied to the surface of a metal substrate, and then the surface of the metal substrate is baked (dried) without rinsing with water. That is, the metal surface treatment method of this embodiment includes a coating step of applying the metal surface treatment agent to the surface of the metal substrate, and a baking step of baking the coated metal surface treatment agent on the metal substrate.
• the coating-type metal surface treatment agent of this embodiment has the advantage that the formation of a metal surface treatment film can be performed relatively easily and no waste liquid is generated.
• the method for coating the surface of the metal substrate with the metal surface treatment agent is not particularly limited, and examples of the method include roll coating, bar coating, spraying, and immersion.
• the surface of the metal substrate may be degreased, pickled, or etched, if necessary.
• the metal surface treatment agent applied to the metal substrate is baked.
• the baking method is not particularly limited.
• the baking temperature is not particularly limited, but it is preferable to set the material reachable temperature (PMT) to 200°C to 400°C, for example.
• the baking time is not particularly limited, but it can be set to, for example, 3 to 180 seconds.
• the film formed by the above-mentioned metal surface treatment method contains each component of the above-mentioned metal surface treatment agent, excluding volatile components such as water. That is, the content of silicon element contained in the metal surface treatment film is 10 mass% or more.
• the molar ratio (M/Si) of the alkali metal element (M) to the silicon element (Si) contained in the metal surface treatment film is preferably 0.5 to 1.2.
• the content of vanadium element contained in the metal surface treatment film is preferably 0.1 to 10 mass%.
• the content of zirconium element contained in the metal surface treatment film is preferably 0.1 to 10 mass%.
• the weight of the film is not particularly limited, but is preferably 0.3 to 2.0 g/ m2 , and more preferably 0.5 to 1.5 g/ m2 .
• the surface-treated metal according to the present embodiment is obtained by forming the metal surface treatment film on the surface of the metal substrate.
• the surface-treated metal may be a metal surface treatment film on which a coating film is formed.
• the paint for forming the coating film is not particularly limited, and a one-coat paint or a primer and a top coat may be used.
• Examples 1 to 36, Comparative Examples 1 to 4 The silicic acid compound (A), the alkali metal salt (B), the vanadium compound (C), the zirconium compound (D), and the chelating agent (E) were weighed out so as to obtain the solid content shown in Tables 1 to 4 below, and ion-exchanged water was added and mixed and stirred so that the total solid content concentration of these compositions in the metal surface treatment agent was 18 mass %, to obtain a metal surface treatment agent.
• the unit of the blending amount of each component shown in Tables 1 to 4 is parts by mass.
• the "Si amount”, “V amount”, and “Zr amount” shown in Tables 1 to 4 respectively indicate the contents (unit: mass %) of silicon element, vanadium element, and zirconium element relative to the total solid content of the metal surface treatment agent.
• A1 J Sodium Silicate No. 3 (sodium silicate, manufactured by Nippon Chemical Industry Co., Ltd.)
• A4 2K potassium silicate (potassium silicate, manufactured by Nippon Chemical Industry Co., Ltd.)
• A5 Hydrolysis product of Ethyl Silicate 28 (Ethyl Silicate, manufactured by Colcoat Co., Ltd.)
• Vanadium Compound (C) C1: Vanadyl sulfate C2: Ammonium metavanadate C3: Sodium metavanadate
• the metal surface treatment agents shown in Tables 1 to 4 were applied to the surfaces of the metal substrates using a bar coater so that the coating amount was 0.7 g/ m2 .
• the metal substrates after application were heated in an oven at a temperature of 550°C for 15 seconds to perform baking.
• the material reached temperature (PMT) during baking was 300°C.
• the following evaluations were performed using the test plates according to the examples and comparative examples obtained as described above.
• test plates according to the Examples have better corrosion resistance results than the test plates according to Comparative Examples 1, 3, and 4, which do not contain any specific components, and the test plate according to Comparative Example 2, which has a silicon element content of less than 10 mass%.
• the metal surface treatment agents according to the Examples have better storage stability than the surface treatment agents according to Comparative Examples 2 and 4.

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• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Chemical Treatment Of Metals (AREA)
• Paints Or Removers (AREA)

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• 2023
  • 2023-11-13 KR KR1020257008563A patent/KR20250042845A/ko not_active Ceased
  • 2023-11-13 CN CN202380063852.2A patent/CN119895078A/zh active Pending
  • 2023-11-13 WO PCT/JP2023/040774 patent/WO2024111458A1/ja not_active Ceased
  • 2023-11-13 JP JP2024560086A patent/JP7813383B2/ja active Active
• 2026
  • 2026-01-30 JP JP2026014212A patent/JP2026063452A/ja active Pending

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