Anticorrosive coating composition, anticorrosive coating film, and anticorrosive coated steel material

Abstract

To provide an anticorrosive coating composition, an anticorrosive coating film and an anticorrosive coated steel material exhibiting excellent anticorrosion properties equal to or higher than those of a zinc-rich paint.SOLUTION: The anticorrosive coating composition contains metal powder and a binder, wherein the metal powder contains aluminum alloy particles containing copper.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an anticorrosion coating composition, an anticorrosion coating film, and an anticorrosion-coated steel material. More specifically, the present invention relates to an anticorrosion coating composition, an anticorrosion coating film, and an anticorrosion-coated steel material that exhibit excellent corrosion prevention properties equal to or better than those of zinc-rich paint. [Background technology]

[0002] Anticorrosion coating compositions have been developed to impart corrosion resistance to steel materials and the like. For example, an anticorrosion coating composition is a coating composition (zinc-rich paint) containing 70 mass% or more of zinc powder. However, zinc-rich paint produces a fragile coating film that is prone to peeling and other problems. Therefore, Patent Document 1 discloses a corrosion prevention method using a metal paint containing a metal powder of a mixture or alloy of aluminum and magnesium. Patent Document 2 discloses a corrosion prevention method using an alloy powder of Al with at least one element selected from Mg, Si, Cd, Ba, Ga, In, Sn, and Bi. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-87267 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-31505 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the corrosion prevention methods described in Patent Documents 1 and 2 sometimes do not provide sufficient corrosion prevention effects.

[0005] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an anticorrosive coating composition, an anticorrosive coating film, and an anticorrosive-coated steel material that exhibit excellent anticorrosion properties equal to or better than those of zinc-rich paint. [Means for solving the problem]

[0006] The present invention, which solves the above problems, mainly comprises the following configuration.

[0007] (1) A corrosion-resistant coating composition comprising a metal powder and a binder, wherein the metal powder comprises aluminum alloy particles containing copper.

[0008] With this configuration, the anticorrosive coating composition exhibits excellent anticorrosion properties equal to or greater than those of zinc-rich paint.

[0009] (2) The anticorrosion coating composition according to (1), wherein the content of the copper in the aluminum alloy particles is 2 to 20 mass %.

[0010] According to this configuration, the anticorrosion coating composition exhibits superior anticorrosion properties. Furthermore, the anticorrosion coating composition is easy to produce because the aluminum alloy particles are easily powdered during production of the aluminum alloy particles.

[0011] (3) The anticorrosion coating composition according to (1) or (2), wherein the aluminum alloy particles have a volume-based average particle size (D50) of 5 to 30 μm.

[0012] According to this configuration, the anticorrosion coating composition tends to have a suitable viscosity and is easy to handle. Furthermore, the anticorrosion coating composition has an appropriate number of alloy particles per unit amount in the resulting coating film, which tends to provide excellent corrosion protection. Furthermore, the coating film is less likely to sag during coating film formation.

[0013] (4) The anticorrosion coating composition according to any one of (1) to (3), wherein the metal powder further contains zinc powder.

[0014] With this configuration, the anticorrosion coating composition exhibits excellent anticorrosion properties for a longer period of time.

[0015] (5) A corrosion-resistant coating formed on a steel material, the corrosion-resistant coating comprising a metal powder and a binder, the metal powder comprising aluminum alloy particles containing copper.

[0016] With this configuration, the anticorrosive coating film exhibits excellent anticorrosion properties equal to or better than those of coating films obtained using zinc-rich paint.

[0017] (6) The corrosion-protective coating according to (5), wherein the metal powder further contains zinc powder.

[0018] With this configuration, the anticorrosion coating film exhibits excellent anticorrosion properties for a longer period of time.

[0019] (7) A corrosion-protective coated steel material comprising a steel material and the corrosion-protective coating film according to (5) or (6) formed on the steel material.

[0020] According to this construction, the corrosion-resistant coated steel material exhibits excellent corrosion resistance equal to or greater than that of corrosion-resistant coated steel material obtained using zinc-rich paint.

[0021] (8) A corrosion-protective coated steel material comprising a steel material, a first corrosion-protective coating film formed on the steel material, and a second corrosion-protective coating film formed on the first corrosion-protective coating film, wherein the first corrosion-protective coating film contains 70 mass% or more of zinc dust, and the second corrosion-protective coating film is the corrosion-protective coating film described in (5) or (6).

[0022] With this configuration, the corrosion-resistant coated steel material exhibits excellent corrosion resistance for a longer period of time. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide an anticorrosion coating composition, an anticorrosion coating film, and an anticorrosion coated steel material that exhibit excellent anticorrosion properties equal to or better than those of zinc-rich paint. DETAILED DESCRIPTION OF THE INVENTION

[0024] <Anti-corrosion coating composition> The anticorrosion coating composition according to one embodiment of the present invention comprises a metal powder and a binder. The metal powder comprises aluminum alloy particles containing copper. Each of these will be described below.

[0025] (metal powder) The metal powder includes aluminum alloy particles containing copper.

[0026] The copper content in the aluminum alloy particles is preferably 2% by mass or more, and more preferably 3% by mass or more. Furthermore, the copper content in the aluminum alloy particles is preferably 20% by mass or less, and more preferably 18% by mass or less. By having the copper content within the above range, the anticorrosion coating composition exhibits superior corrosion prevention. Furthermore, the anticorrosion coating composition is easy to produce because the aluminum alloy particles are easily powdered during production.

[0027] The aluminum alloy particles may contain other metals in addition to copper, as appropriate. The other metals are not particularly limited. Examples of the other metals include manganese, magnesium, chromium, and iron.

[0028] The aluminum content in the aluminum alloy particles is preferably 80% by mass or more, and more preferably 82% by mass or more. Furthermore, the aluminum content in the aluminum alloy particles is preferably 98% by mass or less, and more preferably 97% by mass or less. By having the aluminum content within the above range, the anticorrosion coating composition exhibits superior corrosion prevention. Furthermore, the anticorrosion coating composition is easy to produce because the aluminum alloy particles are easily powdered during production.

[0029] The volume-based average particle diameter (D50) of the aluminum alloy particles is preferably 5 μm or more, more preferably 10 μm or more. Furthermore, the D50 of the aluminum alloy particles is preferably 30 μm or less, more preferably 25 μm or less. When the D50 of the aluminum alloy particles is within the above range, the anticorrosion coating composition tends to have an appropriate viscosity and is easy to handle. Furthermore, the anticorrosion coating composition has an appropriate number of alloy particles per unit amount in the resulting coating film, making it easy to obtain excellent corrosion protection. Furthermore, the coating film is less likely to sag during coating film formation. The volume-based average particle diameter (D50) in this specification is the 50% volume cumulative diameter measured using a laser diffraction particle size distribution analyzer (Microtrac particle size analyzer MT3300, manufactured by Nikkiso Co., Ltd.). When measuring the volume-based average particle diameter (D50), if the particles are aggregated, ultrasonic dispersion is required immediately before measurement.

[0030] The content of the aluminum alloy particles in the metal powder is preferably 80 mass% or more, more preferably 90 mass% or more. The content of the aluminum alloy particles in the metal powder may be 100 mass%. When the content of the aluminum alloy particles is within the above range, the anticorrosion coating composition tends to exhibit excellent corrosion prevention properties.

[0031] The metal powder may further contain zinc powder, which allows the anticorrosion coating composition to exhibit excellent anticorrosion properties for a longer period of time.

[0032] When zinc dust is contained, the content of zinc dust is not particularly limited. For example, the content of zinc dust in the metal powder is preferably 30 mass% or more. Furthermore, the content of zinc dust in the metal powder is preferably 70 mass% or less. When the content of zinc dust is within the above range, the anticorrosion coating composition exhibits excellent corrosion prevention properties for a longer period of time.

[0033] The volume-based average particle size (D50) of the zinc dust is preferably 1 μm or more, more preferably 2 μm or more. Furthermore, the D50 of the zinc dust is preferably 20 μm or less, more preferably 10 μm or less. When the D50 of the zinc dust is within the above range, the anticorrosion coating composition exhibits excellent anticorrosion properties.

[0034] Returning to the explanation of the metal powder as a whole, the content of the metal powder is not particularly limited. For example, the content of the metal powder is preferably 70 mass% or more, more preferably 75 mass% or more, of the total solid content of the anticorrosion coating composition. Furthermore, the content of the metal powder is preferably 99 mass% or less, more preferably 95 mass% or less, of the total solid content of the anticorrosion coating composition. By having the content of the metal powder within the above range, the anticorrosion coating composition exhibits excellent corrosion prevention properties.

[0035] The method for producing metal powder is not particularly limited. For example, metal powder can be produced by gas atomization or the like. More specifically, a molten aluminum or aluminum alloy, which serves as the raw material for the metal powder, is first prepared in a melting furnace. To produce a molten aluminum metal, for example, aluminum ingot may be introduced into the melting furnace. The aluminum ingot may be high-purity aluminum with a purity of 99.9% by mass or higher, or may contain impurities such as 0.15% by mass or less of silicon (Si) and / or 0.2% by mass or less of iron (Fe). To produce a molten aluminum alloy, for example, aluminum ingot may be introduced into the melting furnace, and other elements may be introduced so that the content (mass %) of the other elements in the molten metal reaches the desired composition. Next, the molten metal in the melting furnace is subjected to gas atomization to produce metal powder. According to the gas atomization method, one end of a pipe with a nozzle attached to the other end is immersed in molten metal, and a negative pressure region is created near the nozzle using high-pressure gas. The molten metal is then sucked up into the nozzle and sprayed through the nozzle hole to produce metal powder.

[0036] The metal powder may be produced by water atomization, rotating electrode method, plasma atomization, centrifugal atomization, mechanical alloying, chemical process, or the like.

[0037] (binder) The binder is not particularly limited, and examples thereof include various organic binders and inorganic binders.

[0038] Examples of organic binders include epoxy resins, polyester resins, polyurethane resins, polyacrylic resins, polyol resins, polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives, acetate resins, polyvinyl chloride resins, polyimide resins, latex resins, starch, gelatin, vegetable proteins, casein, gum arabic, albumin, etc. Examples of inorganic binders include inorganic oxide sols such as alkyl silicate condensates, silica sols, alumina sols, zirconia sols, and titania sols.

[0039] Among these, the binder is preferably an epoxy resin, such as a bisphenol-type epoxy resin, a glycidyl ester-modified epoxy resin, a glycidyl amine-modified epoxy resin, a novolac-modified epoxy resin, a dimer acid-modified epoxy resin, an aliphatic-modified epoxy resin, or an aromatic-modified epoxy resin.

[0040] The content of the binder is not particularly limited. For example, the content of the binder is preferably 1% by mass or more, more preferably 5% by mass or more, of the total solid content of the anticorrosion coating composition. Furthermore, the content of the binder is preferably 20% by mass or less, more preferably 15% by mass or less, of the total solid content of the anticorrosion coating composition. When the content of the binder is within the above range, the anticorrosion coating composition exhibits excellent corrosion prevention properties.

[0041] Other components of the anticorrosion coating composition are not particularly limited. As an example, the anticorrosion coating composition is preferably a two-component coating composition consisting of a base agent containing a metal powder and a binder, and a curing agent. Such a coating composition is used by mixing the base agent and the curing agent at the time of application, and can be easily used as a room temperature drying type coating composition. Note that a one-component coating composition may also be used as the anticorrosion coating composition.

[0042] When the binder is an epoxy resin, the curing agent preferably contains an amine-based compound, and examples thereof include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine; aromatic polyamines such as metaxylylenediamine, diaminodiphenylmethane, and phenylenediamine; alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane and isophoronediamine; and modified polyamines obtained by subjecting these polyamines to modification reactions such as polyamidation, epoxy adduct formation, Mannich conversion, and ketiminization by known methods.

[0043] (optional ingredient) The anticorrosion coating composition of this embodiment may contain, in addition to the metal powder and the binder, optional components as appropriate. The optional components are not particularly limited. Examples of optional components include reactive diluents, silane coupling agents, pigments (coloring pigments, extender pigments, anti-rust pigments, etc.), solvents, pigment dispersants, leveling agents, anti-sagging agents, and antifoaming agents.

[0044] There is no particular limitation on the method for producing the anticorrosion coating composition. For example, the anticorrosion coating composition can be produced by mixing metal powder, a binder, and optional components.

[0045] The viscosity of the anticorrosion coating composition is not particularly limited. For example, the viscosity is preferably 1 Pa·s or more, and more preferably 5 Pa·s or more. Furthermore, the viscosity is preferably 100 Pa·s or less, and more preferably 20 Pa·s or less. When the viscosity is within the above range, the anticorrosion coating composition has excellent coating workability and can form a uniform coating film. In this embodiment, the viscosity can be measured using a B-type rotational viscometer (BII-type viscometer, manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C and a rotation speed of 20 rpm, using a No. 5 rotor.

[0046] The anticorrosion coating composition of this embodiment can form an anticorrosion coating film with excellent adhesion and corrosion prevention properties on various steel materials and zinc plating layers.

[0047] As described above, according to this embodiment, the anticorrosive coating composition exhibits excellent anticorrosion properties equal to or better than those of zinc-rich paint.

[0048] <Anti-corrosion coatings, anti-corrosion coated steel> A corrosion-resistant coating according to one embodiment of the present invention is a corrosion-resistant coating formed on a steel material. The corrosion-resistant coating includes a metal powder and a binder. The metal powder includes aluminum alloy particles containing copper. A corrosion-resistant coated steel material according to one embodiment of the present invention is a corrosion-resistant coated steel material having a steel material and a corrosion-resistant coating formed on the steel material. Each of these will be described below. In the following description, the metal powder and binder are the same as those described above in relation to the embodiment of the corrosion-resistant coating composition. Therefore, redundant description will be omitted as appropriate.

[0049] The steel material is not particularly limited. For example, the steel material may be steel material used for structures such as various plant structures, land structures, marine structures, ships, etc. (including base materials used when constructing these structures and base materials constituting these structures). The steel material may also be steel material coated with an old paint film from which the old paint film has been removed.

[0050] The anticorrosion coating film is a coating film obtained by applying the above-mentioned anticorrosion coating composition and drying it. The dry film thickness of the coating film is not particularly limited. For example, the dry film thickness is preferably 40 to 300 μm, and more preferably 50 to 270 μm. When the dry film thickness is within the above range, the obtained anticorrosion coating film can exhibit sufficient corrosion prevention properties and adhesion to steel materials.

[0051] The method for applying the corrosion-protective coating composition to the steel material is not particularly limited. For example, the coating may be performed using an air spray, an airless spray, a brush, a roller, a spatula, a trowel, or the like. This allows the corrosion-protective coating film of the present embodiment and a corrosion-protective coated steel material having the corrosion-protective coating film formed thereon to be produced. The obtained corrosion-protective coating film exhibits excellent corrosion protection for a longer period of time. Furthermore, the corrosion-protective coated steel material exhibits excellent corrosion protection equal to or greater than that of a corrosion-protective coated steel material obtained using zinc-rich paint.

[0052] The anticorrosion coating film of this embodiment may further have one or more coating layers (undercoat coating film, intermediate coating film, topcoat coating film) formed thereon.

[0053] The primer coating film is a layer formed on the anticorrosion coating film by applying a primer coating composition. The primer coating composition is not particularly limited. Examples of the primer coating composition include epoxy resin coatings, modified epoxy resin coatings, epoxy resin-based glass flake coatings, epoxy resin coating materials, ultra-thick film epoxy resin coatings, chlorinated rubber resin coatings, phthalic acid resin coatings, and epoxy ester resin coatings.

[0054] The method for applying the undercoat paint composition is not particularly limited, and examples thereof include known methods such as spray coating, roller coating, brush coating, and flow coating.

[0055] The undercoat paint composition is applied as appropriate under painting conditions of humidity of 85% or less, at 5 to 35°C, and for about 12 to 48 hours, and then dried.

[0056] The dry film thickness of the primer coating film is not particularly limited. For example, the dry film thickness is preferably 30 μm or more, more preferably 45 μm or more. Furthermore, the dry film thickness is preferably 200 μm or less, more preferably 180 μm or less. When the dry film thickness is within the above range, the resulting coated product has better rust prevention properties, weather resistance, and water resistance.

[0057] The intermediate coating film is a layer formed on the base coating film by applying an intermediate coating film composition. The intermediate coating composition is not particularly limited. Examples of intermediate coating compositions include epoxy resin-based paints, polyurethane-based paints, epoxy resin MIO paints, phenolic resin-based MIO paints, chlorinated rubber resin-based paints, and phthalic acid resin-based paints.

[0058] The method for applying the intermediate coating composition is not particularly limited, and examples thereof include known methods such as spray coating, roller coating, brush coating, and flow coating.

[0059] The intermediate coating composition is applied as appropriate under coating conditions of a humidity of 85% or less, at 5 to 35°C, and for about 12 to 48 hours, and then dried.

[0060] The dry film thickness of the intermediate coating film is not particularly limited. For example, the dry film thickness is preferably 10 μm or more, more preferably 20 μm or more. Furthermore, the dry film thickness is preferably 100 μm or less, more preferably 80 μm or less. When the dry film thickness is within the above range, the resulting coated product has better rust prevention properties, weather resistance, and water resistance.

[0061] The topcoat film is a layer formed on the intermediate coating film by applying a topcoat paint composition. When the intermediate coating layer is omitted, the topcoat film may be formed on the primer coating film.

[0062] The topcoat paint composition is not particularly limited, and examples thereof include acrylic resin-based paints, urethane resin-based paints, epoxy resin-based paints, chlorinated polyolefin-based paints, silicone resin-based paints, fluororesin-based paints, chlorinated rubber resin-based paints, phthalic acid resin-based paints, epoxy resin MIO paints, and phenolic resin MIO paints.

[0063] The method for applying the topcoat paint composition is not particularly limited, and examples of the application method that can be used include known methods such as spray coating, roller coating, brush coating, and flow coating.

[0064] The topcoat paint composition is applied as appropriate under painting conditions of a humidity of 85% or less, at 0 to 35°C, and for about 4 to 48 hours, and then dried.

[0065] The dry film thickness of the topcoat coating film is not particularly limited. For example, the dry film thickness is preferably 10 μm or more, more preferably 20 μm or more. Furthermore, the dry film thickness is preferably 100 μm or less, more preferably 80 μm or less. When the dry film thickness is within the above range, the resulting coated product has better rust prevention properties, weather resistance, and water resistance.

[0066] <Other embodiments of corrosion-resistant coated steel material> In the above embodiment, a corrosion-protective coated steel material having a single layer of corrosion-protective coating film formed thereon is exemplified. However, in the present embodiment, a corrosion-protective coated steel material having a plurality of corrosion-protective coating films formed thereon may be used instead.

[0067] As an example, the corrosion-protective coated steel material of this embodiment is a corrosion-protective coated steel material having a steel material, a first corrosion-protective coating formed on the steel material, and a second corrosion-protective coating formed on the first corrosion-protective coating. The first corrosion-protective coating contains 70 mass% or more of zinc dust. The second corrosion-protective coating is similar to the corrosion-protective coating described in the embodiment of the corrosion-protective coated steel material having a single layer of corrosion-protective coating formed thereon. That is, the corrosion-protective coated steel material of this "other embodiment" differs from the embodiment of the corrosion-protective coated steel material having a single layer of corrosion-protective coating formed thereon in that a first corrosion-protective coating is further provided between the steel material and the second corrosion-protective coating, but is otherwise similar.

[0068] First anti-corrosion coating The first corrosion-protective coating film contains 70 mass % or more of zinc dust. The method for forming the first corrosion-protective coating film is not particularly limited. For example, the first corrosion-protective coating film can be formed by applying a first corrosion-protective coating composition.

[0069] The first anticorrosion coating composition is not particularly limited. For example, the first anticorrosion coating composition contains a metal powder including zinc powder, a binder, and optional components.

[0070] The volume-based average particle size (D50) of the zinc dust is preferably 1 μm or more, more preferably 2 μm or more. Furthermore, the D50 of the zinc dust is preferably 20 μm or less, more preferably 10 μm or less. When the D50 of the zinc dust is within the above range, the first anticorrosion coating composition tends to have an appropriate viscosity and is easy to handle.

[0071] The first anticorrosion coating composition may be a commercially available zinc-rich paint, including organic zinc-rich paints and inorganic zinc-rich paints.

[0072] The first corrosion-protective coating film is a coating film obtained by applying and drying the above-mentioned first corrosion-protective coating composition. The dry film thickness of the coating film is not particularly limited. For example, the dry film thickness is preferably 10 to 100 μm, and more preferably 20 to 50 μm. When the dry film thickness is within the above range, the obtained first corrosion-protective coating film can exhibit sufficient corrosion protection and adhesion to steel materials.

[0073] The method for applying the first anticorrosion coating composition to the steel material is not particularly limited, and examples thereof include air spray, airless spray, brush, roller, spatula, trowel, and the like.

[0074] Second anti-corrosion coating The second corrosion-protective coating is the corrosion-protective coating described above in relation to the embodiment of the single-layer corrosion-protective coating. The method for forming the second corrosion-protective coating is not particularly limited. For example, the second corrosion-protective coating can be formed by the same method as the method described above in relation to the embodiment of the single-layer corrosion-protective coating.

[0075] The second corrosion-protective coating is a coating obtained by applying and drying the corrosion-protective coating composition of the above-described embodiment. While the dry thickness of the coating is not particularly limited, it is characterized by exhibiting high corrosion protection performance at a thickness thinner than that of the single-layer corrosion-protective coating of the above-described embodiment. For example, the dry thickness is preferably 10 to 100 μm, more preferably 20 to 50 μm. By ensuring that the dry thickness is within the above range, the resulting second corrosion-protective coating can exhibit sufficient corrosion protection and adhesion to the first corrosion-protective coating. Furthermore, the corrosion-protective coated steel of this embodiment exhibits higher corrosion protection performance than a typical zinc-rich paint, even when the total thickness of the two layers (the first and second corrosion-protective coatings) is comparable to that of a typical zinc-rich paint single layer (e.g., 100 μm or less).

[0076] The method for applying the anticorrosion coating composition of the above embodiment to the first anticorrosion coating film is not particularly limited. For example, the application may be performed using an air spray, airless spray, brush, roller, spatula, trowel, or the like.

[0077] The corrosion-protective coated steel of this embodiment may have one or more coating layers (primer coating, intermediate coating, topcoat coating) formed on the second corrosion-protective coating. These primer coating, intermediate coating, and topcoat coating layers are the same as those described above in connection with the single-layer corrosion-protective coating embodiment.

[0078] As described above, according to this embodiment, the corrosion-resistant coated steel material exhibits excellent corrosion resistance for a longer period of time. [Example]

[0079] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0080] The raw materials used and the methods for preparing the raw materials are shown below. <Metal powder> (Metal powder A) Al metal powder with a D50 of 20 μm was used. (Alloy B) First, a molten aluminum alloy was prepared in a melting furnace to serve as the raw material for the metal powder. The raw aluminum alloy was introduced into the furnace, and Cu, Mn, and Mg were added so that the content (mass%) of other elements in the molten metal was the target composition. The aluminum alloy contained 0.15 mass% or less of silicon (Si) and / or 0.2 mass% or less of iron (Fe) as impurities. The molten metal in the melting furnace was then gas atomized to produce metal powder. The resulting alloy B had a composition of 93.6 mass% Al, 4.3 mass% Cu, 0.6 mass% Mn, and 1.5 mass% Mg. The D50 of alloy B was 20 μm. (Alloy C~Alloy F) Alloys C to F were produced in the same manner as Alloy B, except that the raw materials were changed so as to have the compositions shown in Table 1. (Metal powder G) Al metal powder with a D50 of 2 μm was used.

[0081] [Table 1]

[0082] Alkylphenol novolac modified epoxy resin: EPICLON 5970-60, manufactured by DIC Corporation, solid content 60% by mass, binder Talc: MS412, manufactured by Fuji Talc Industries Co., Ltd. Clay: BENTONE SD-1, manufactured by Elementis Anti-sagging agent: ASA T-380-20BS, manufactured by Ito Oil Mills, solid content 20% by mass Antifoaming agent, FLORENE AC-903, manufactured by Kyoeisha Chemical Co., Ltd. Curing agent (polyamidoamine): Tomide TXP-696; manufactured by T&K TOKA Corporation, solid content 80% by mass High-boiling aliphatic and aromatic hydrocarbon mixed solvent: HAWS; Shell Chemicals

[0083] <Comparative Example 1> An anticorrosion coating composition of Comparative Example 1 was prepared according to the following formulation 1. (Formulation 1) Alkylphenol novolac modified epoxy resin 14.5 Metal powder A 70.0 Talc 4.5 Clay 0.5 Anti-sagging agent 4.0 Antifoaming agent 0.2 Hardener 0.7 High boiling point aliphatic and aromatic hydrocarbon mixed solvent 10.0 Total 104.4 (parts by mass)

[0084] <Examples 1 to 3, Comparative Examples 2 and 3> Anticorrosion coating compositions of Examples 1 to 3 and Comparative Examples 2 and 3 were produced using the same formulation as Formulation 1 above, except that the types of alloys were changed to achieve the combinations shown in Table 2 below.

[0085] [Table 2]

[0086] Test plates were prepared according to the following method for the anticorrosive coating compositions of Examples 1 to 3 and Comparative Examples 1 to 3, and a neutral salt spray test (SST) was conducted to evaluate the corrosion resistance. The results are shown in Table 2. The coating film thickness on the test plates was 140 μm.

[0087] (Preparation of test plates) The anticorrosion coating composition was sprayed onto a 70 mm x 150 mm x 3.2 mm blasted SS400 steel plate (steel grid) using an air spray to a predetermined thickness and then dried at 23°C for 4 hours to form an anticorrosion coating. Next, a primer (New Epo 21HB Primer, manufactured by Tohpe Corporation, modified epoxy resin coating, 125 μm thickness), an intermediate coat (New Fusso 21 Intermediate Coat E, manufactured by Tohpe Corporation, intermediate coat for fluororesin coating, 35 μm thickness), and a top coat (New Fusso 21DC Top Coat, manufactured by Tohpe Corporation, fluororesin coating, 30 μm thickness) were applied sequentially to the predetermined thicknesses. The interval between coats was 24 hours at 23°C. An X-cut scratch was made on the resulting coated plate according to JIS K 5400;1990 8.5.3 X-cut tape method to prepare a test plate (corrosion-protective coated steel). (Neutral salt spray test (SST)) A neutral salt spray resistance test (SST) was conducted in accordance with JIS K 5600-7-1 and classified according to the following criteria. Note that the "cut area" refers to the area with the X-cut scratch, and the "general area" refers to the rest of the coating surface. ⊚: No red rust was observed on either the cut or general areas, or only a small amount of red rust was observed on the cut areas. ◯: There was a slight amount of red rust on the cut and general areas, or a slight amount of rust fluid was observed on the cut areas. △: Rust leaked from the cut area. ×: A lot of rust leaked out from the cut area.

[0088] As shown in Table 1, the anticorrosion coating compositions of Examples 1 to 3 of the present invention and the anticorrosion coating films obtained from the anticorrosion coating compositions exhibited excellent anticorrosion properties.

[0089] Example 4 The anticorrosion coating composition of Example 4 was prepared using the same formulation as Formulation 1, except that Formulation 2 was used, in which 70 parts by mass of metal powder A in Formulation 1 was replaced with 35 parts by mass of alloy B and 35 parts by mass of zinc powder (zinc powder (F), D50: 4 μm, manufactured by Hakusui Tech Co., Ltd.).

[0090] <Comparative Example 4, Example 5> Anticorrosion coating compositions of Comparative Example 4 and Example 5 were produced using the same formulation as in Example 4 above, except that the types of alloys were changed to achieve the combinations shown in Table 3 below.

[0091] [Table 3]

[0092] Test plates were prepared in the same manner as above for the anticorrosive coating compositions of Examples 4 to 5 and Comparative Example 4, and a neutral salt spray test (SST) was conducted to evaluate the corrosion resistance. The results are shown in Table 3. The thickness of the anticorrosive coating film on the test plates was 70 μm.

[0093] As shown in Table 3, the anticorrosion coating compositions and the anticorrosion coating films obtained from the anticorrosion coating compositions of Examples 4 and 5 of the present invention exhibited excellent anticorrosion properties.

[0094] Example 6 A first anticorrosion coating composition was prepared by employing formulation 3, in which 70 parts by mass of zinc powder (zinc powder (F), D50: 4 μm, manufactured by Hakusui Tech Co., Ltd.) was used instead of 70 parts by mass of the alloy (alloy A) in formulation 1. A second anticorrosion coating composition was prepared using the same formulation as formulation 1, except that alloy B was used.

[0095] Example 7 A first anticorrosion coating composition and a second anticorrosion coating composition were prepared in the same manner as in Example 6, except that alloy D was used instead of alloy B.

[0096] For the anticorrosion coating compositions of Examples 6 and 7, a first anticorrosion coating film having a thickness of 35 μm was formed by coating a first anticorrosion coating composition. A second anticorrosion coating film having a thickness of 45 μm was then formed on the first anticorrosion coating film. The obtained test plates were subjected to a neutral salt spray test (SST) using the same method as above, and their corrosion resistance was evaluated. The results are shown in Table 4.

[0097] [Table 4]

[0098] As shown in Table 4, the anticorrosion coating compositions of Examples 6 and 7 of the present invention and the anticorrosion coating films obtained from the anticorrosion coating compositions exhibited excellent anticorrosion properties.

Claims

1. Contains metal powder and a binder, The anticorrosion coating composition, wherein the metal powder comprises aluminum alloy particles containing copper.

2. 2. The anticorrosion coating composition according to claim 1, wherein the content of said copper in said aluminum alloy particles is 2 to 20 mass %.

3. 3. The anticorrosion coating composition according to claim 1, wherein the aluminum alloy particles have a volume-based average particle size (D50) of 5 to 30 μm.

4. 3. The anticorrosion coating composition according to claim 1, wherein the metal powder further contains zinc powder.

5. It is a corrosion-resistant coating formed on steel materials. Contains metal powder and a binder, The metal powder comprises aluminum alloy particles containing copper.

6. The corrosion-protective coating according to claim 5 , wherein the metal powder further contains zinc powder.

7. A corrosion-protective coated steel material comprising a steel material and the corrosion-protective coating film according to claim 5 or 6 formed on the steel material.

8. A steel material, a first corrosion-resistant coating film formed on the steel material, and a second corrosion-resistant coating film formed on the first corrosion-resistant coating film, the first corrosion-protective coating film contains 70 mass% or more of zinc powder, 7. A corrosion-resistant coated steel material, wherein the second corrosion-resistant coating film is the corrosion-resistant coating film according to claim 5 or 6.

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