Waterborne heavy anti-corrosion coating for construction of rusty and residual paint film

Abstract

The invention discloses a water-based heavy anti-corrosion coating for construction with rust and residual paint films. The coating comprises an ionic water-based modified alkyd emulsion, water-based fluorocarbon resin, deionized water, an anti-rust pigment, a filler, an anti-flash rust agent, a salt spray resistant auxiliary agent, a self-repairing auxiliary agent, a penetrant, a corrosion inhibitor, a thixotropic agent and an auxiliary agent. The coating contains the anti-rust pigment, the filler, the flash-rust inhibitor and the salt-spray-resistant additive, the four components interact with each other and can act on the steel surface and rust left on the surface to generate a stable chelate passivation layer and a complex, and the product is strongly attached to the steel surface in the form of physical bonds and chemical bonds to form a good insoluble protective film, so that the corrosion resistance of the coating is improved, and the service life of the coating is prolonged. The rust inhibitor can stabilize rust and prevent rust, inhibits the corrosion process, realizes construction with rust, and has the advantages of safety, environmental protection, construction with rust and residual paint film and the like.

Description

A water-based heavy-duty anti-corrosion coating for application with rust and residual paint film Technical Field

[0001] This invention belongs to the field of corrosion and anti-corrosion technology, specifically relating to a water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film. Background Technology

[0002] Steel structures possess advantages such as high strength and toughness, ease of fabrication, and short construction cycles, leading to their increasingly widespread application in the construction and engineering fields. Applying anti-corrosion coatings to steel structures is one of the more economical and reasonable anti-corrosion measures. However, many complex steel structures, such as buildings, bridges, and towers, are limited by structural factors during construction or maintenance, requiring manual or light power tools for surface treatment such as rust removal. This results in rust and other corrosion products remaining on the steel structure surface, especially in corners and dead angles, making it difficult to meet the Sa2.5 standard or higher. During continuous corrosion and maintenance, steel structures exhibit a coexistence of the original (thick, cracked) paint film, zinc film, and rust, requiring coatings to possess excellent comprehensive properties such as thick film curing, penetration, and good toughness.

[0003] According to Article 11, Section 4 of Category I of the "Guidance Catalogue for Industrial Structure Adjustment (2024 Edition)," coatings and dyes (pigments): environmentally friendly and resource-saving coatings with low VOC content; high-performance coatings and supporting resins used in key areas such as large aircraft, high-speed rail, large ships, new energy, and electronics; and the development and production of new dyes, pigments, printing and dyeing auxiliaries and intermediates used in fields such as phototherapy, photoresist, liquid crystal displays, photovoltaic cells, solution coloring, digital inkjet printing, and functional chemical fiber dyeing are encouraged. Coatings capable of being applied to areas with rust and residual paint film are developing towards water-based, high-performance, easy-to-apply, and environmentally friendly directions.

[0004] Chinese invention patent CN105017926A (A nano-composite zinc-containing anti-corrosion coating for rust-prone steel structures) discloses a nano-composite zinc-containing anti-corrosion coating for rust-prone steel structures. The coating mainly uses two components, A and B. Component A includes epoxy resin, nano-composite anti-rust components, reduced zinc powder, butyl ether, xylene, butanol, organobentonite, mica powder, and toughening agent. Component B includes polyamide, xylene, and butanol. The anti-corrosion mechanism of this coating includes a shielding effect and the cathodic protection effect of Zn. Chinese invention patent CN101372599B (An epoxy heavy-duty anti-corrosion coating applicable to rust-prone steel structures and its preparation method) discloses an epoxy heavy-duty anti-corrosion coating applicable to rust-prone steel structures and its preparation method. The coating mainly uses component A (epoxy resin, pigment, filler, additives, solvent) and component B (cashew oil modified epoxy curing agent, cashew oil modified epoxy curing agent, filler, solvent). The weight percentages of component A are as follows: epoxy resin 10-40%, pigment 2-5%, filler 35-60%, additives 2-5%, solvent 10-20%. The weight percentages of component B include: NX-2041 cashew oil modified epoxy curing agent 40-50%, NX-2040 cashew oil modified epoxy curing agent 5-10%, filler 15-20%, and solvent 15-30%. It can be applied to steel structure surfaces with low rust removal requirements. The solvents for components A and B are selected from aromatic hydrocarbons, alcohols, or alcohol ethers. Chinese invention patent CN101760109A (Two-component epoxy phenolic rust-resistant primer and its preparation process) discloses a two-component solvent-based rust-resistant primer using epoxy resin and phenolic resin as film-forming materials. It consists of two components with a weight ratio of 6:1 for component one and component two. Component one contains epoxy phenolic resin liquid, rust-preventive pigments, fillers, additives, and solvents, while component two is an epoxy curing agent. It is mixed immediately before use and can be directly applied to large steel surfaces with a thin layer of rust, eliminating the need for surface treatment before coating large steel components. However, this type of coating uses a large amount of organic solvents, which does not meet current green and environmental protection requirements.

[0005] Chinese invention patent CN102391732A (Water-based environmentally friendly anti-corrosion coating primer for steel rust) discloses a water-based environmentally friendly anti-corrosion coating primer for steel rust. It uses styrene-acrylic emulsion and tannic acid as a rust conversion agent. It is made by mixing the following raw materials in the following weight ratio: 200-300 parts deionized water, 100-150 parts styrene-acrylic emulsion, 5-8 parts tannic acid, 7-10 parts graphite powder, 0.5-2 parts polyvinyl alcohol, 2-5 parts sodium methyl cellulose, and 0.5 parts potassium sorbate. Chinese invention patent CN101921516B (A water-based anti-corrosion transparent coating suitable for steel surfaces and its preparation method) discloses a water-based anti-corrosion transparent coating suitable for steel surfaces and its preparation method. The coating raw materials mainly consist of water-based film-forming resin, water-based film-forming aid, nano-level filler, nano-level anti-rust pigment, dispersant, water-based defoamer, water-based wetting agent, water-based leveling agent, rust conversion liquid, surfactant, and the balance being deionized water. The aqueous film-forming resin is an aqueous self-crosslinking styrene-acrylic emulsion MC-101, MC-102, MC-201, or MC-202; the nano-level filler is nano-level titanium dioxide, nano-level silica, nano-level talc, or nano-level mica powder; the nano-level anti-rust pigment is nano-level aluminum tripolyphosphate, nano-level zinc phosphate, nano-level zinc molybdate, or nano-level zinc phosphomolybdate; the rust conversion solution is prepared by mixing 1 part by weight of potassium ferrocyanide with 2-10 parts by weight of pretreatment acid solution, wherein the pretreatment acid solution can be phosphoric acid, phytic acid, or tannic acid. The coating containing the conversion solution causes rust to transform into a hard shell with mismatched strength, hardness, toughness, and modulus. Although the bonding strength is increased during film formation, it will quickly crack and peel off due to thermal expansion and contraction during service, leading to the failure of the anti-corrosion coating.

[0006] Chinese invention patent CN105925030A (A Rust-Proof Anti-Corrosion Coating for Steel and Its Preparation Method) discloses a rust-proof anti-corrosion coating for steel and its preparation method. The coating's main raw materials include pure water, polyvinyl chloride resin, silicone rubber, acetone, vermiculite powder, kaolin, white oil, glycerin, benzotriazole, barium petroleum sulfonate, vinyl acetate, butyl acrylate, acrylic acid, and potassium persulfate. Chinese invention patent CN105925098A (A Water-Based Rust-Proof Anti-Corrosion Coating for Steel and Its Preparation Method) discloses a water-based rust-proof anti-corrosion coating for steel and its preparation method. The raw materials are butyl methacrylate, potassium ferrocyanide, polyol phosphonate, methyl acrylate, acrylonitrile, N-hydroxymethylacrylamide, toluene diisocyanate, talc, zinc oxide, barium sulfate, lauryl methacrylate, sodium dodecyl sulfonate, acrylic acid, and aluminum tripolyphosphate. The raw materials are stirred and then ground. Chinese invention patent CN118956228A (A Water-Based Anti-Corrosion Coating for Rust-Proof Application) discloses a water-based anti-corrosion coating for rust-proof application, comprising, by weight: 14-23 parts rust inhibitor, 12-17 parts polycarboxylated epoxy resin, 3-5 parts dehydrating agent, 5-7 parts corrosion inhibitor, 7-12 parts rust-preventive pigment, and 50-70 parts water. The rust inhibitor includes organophosphonates and polyether-modified siloxanes, with a weight ratio of (9-13):(5-10) for the organophosphonates and polyether-modified siloxanes. The addition of polycarboxylated epoxy resin allows the anti-corrosion coating to have higher permeability and better physical properties when bonded to rust-prone surfaces. The anti-corrosion mechanism of this type of water-based anti-rust coating is a shielding effect, providing protection by shielding the coating from corrosive media in the environment. The coating lacks self-healing capabilities. Once the coating is damaged, the steel substrate at the damaged area will corrode and the corrosion will continue to spread, causing the coating to lose its anti-corrosion function. Summary of the Invention

[0007] The technical problem this invention aims to solve is to address the shortcomings of the existing technology by providing a water-based heavy-duty anti-corrosion coating suitable for application even with rust and residual paint film. This coating offers advantages such as safety, environmental friendliness, and the ability to be applied even with rust and residual paint film. It can penetrate not only the rust layer but also the residual paint film, providing safe, long-lasting, and easy-to-apply anti-corrosion protection and maintenance for steel products. Furthermore, within the effective anti-corrosion period, the coating will not crack, peel, or flake off, preventing the steel products from rusting or re-rusting, thus ensuring their sustainable use.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a water-based heavy-duty anti-corrosion coating for application with rust and residual paint film, characterized in that, calculated by weight, it comprises: 20-28 parts of ionic water-based modified alkyd emulsion, 5-10 parts of water-based fluorocarbon resin, 25-35 parts of deionized water, 5-10 parts of anti-rust pigment, 10-20 parts of filler, 2-5 parts of anti-flash rust agent, 3-6 parts of salt spray resistant additive, 5-8 parts of self-healing additive, 0.2-0.8 parts of penetrant, 0.1-0.4 parts of corrosion inhibitor, 1-2 parts of thixotropic agent, and 0.4-1.2 parts of additives.

[0009] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the ionic water-based modified alkyd emulsion is an acrylic modified alkyd emulsion.

[0010] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the anti-rust pigment is a phosphate and / or an organophosphonate; the filler is barium sulfate, zinc hydroxide and nano-polyethylene wax powder, the mass ratio of barium sulfate to zinc hydroxide is 1:(3~6), and the mass ratio of the sum of the masses of barium sulfate and zinc hydroxide to the mass of nano-polyethylene wax powder is 1:(3~6); the flash rust inhibitor is an organic amine and / or an aminocarboxylate.

[0011] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the phosphate is aluminum zinc phosphate or polyphosphate, the organophosphonate is tetrasodium hydroxyethylidene diphosphonate or sodium dimethylphenylphosphonate, the organic amine is pentamethyldiethylenetriamine or triethanolamine, and the aminocarboxylate is sodium p-dimethylaminoazobenzoic acid or sodium 6-acetaminopyridinecarboxylate.

[0012] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the salt spray resistant additive is modified vermiculite and / or modified graphene.

[0013] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the self-healing additive is a nano-conductive polymer polyaniline, polypyrrole, or polythiophene; and the penetrant is sodium fatty alcohol polyoxyethylene ether sulfate and / or sulfonic acid anionic surfactant.

[0014] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the corrosion inhibitor is maleic acid and / or amino acids.

[0015] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the thixotropic agent is fumed silica and / or castor oil modified derivative.

[0016] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the additives include modified polysiloxane defoamer, low surface tension wetting agent, leveling agent and dispersant.

[0017] The above-mentioned water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is characterized in that the modified polysiloxane defoamer is a single-end vinyl-modified polysiloxane defoamer or a fluorocarbon-modified polysiloxane defoamer; the low surface tension wetting agent is a fluorocarbon wetting agent; the leveling agent is a vinyl-end modified polymethyltrifluoropropylsiloxane leveling agent, a modified polyacrylate copolymer leveling agent, or an organosilicon leveling agent; and the dispersant is a sodium polycarboxylate, an ammonium polycarboxylate, or a polymeric dispersant.

[0018] Compared with the prior art, the present invention has the following advantages: 1. The coating of the present invention uses water as a solvent and does not use organic solvents (volatile organic compounds, VOCs), which is beneficial to environmental protection and health protection.

[0019] 2. The coating of the present invention contains anti-rust pigments, fillers, anti-flash rust agents, and salt spray resistant additives. The four interact with each other to react with the steel surface and the rust remaining on the surface, producing a stable chelate passivation layer and complex. The products adhere strongly to the steel surface in the form of physical and chemical bonds, forming a good insoluble protective film that stabilizes and prevents rust, inhibits the corrosion process, and enables construction on rusted surfaces.

[0020] 3. The coating of the present invention contains corrosion inhibitors and nano-conductive polymers, which can passivate the steel surface to form a dense oxide film, delaying corrosion. Furthermore, when the oxide film on the steel surface is damaged, this conductive polymer material can induce the oxide film to gradually repair itself, giving the passivation layer and coating a self-healing function, and providing continuous protection for steel products.

[0021] 4. The coating of this invention contains a penetrant, which allows the coating to penetrate into rust layers, residual paint films, and steel surfaces. It transforms excess rust into filler within the coating, promoting the formation of chelate passivation layers and complexes, enabling application even with rust and residual paint films, and resulting in a coating with high bonding strength. The penetrant also displaces ionic and atomic harmful substances (such as oxygen atoms, hydroxide ions, and bicarbonate ions) adsorbed on steel surface defects into the coating, accelerating surface drying and hard drying. The penetrant desorbs these ionic and atomic harmful substances, preventing the coating from cracking or peeling due to the desorption and vaporization of these substances under high temperatures, thus providing long-lasting protection. The displaced ionic and atomic harmful substances also promote the formation of a passivation layer, enhancing the coating's protective effect.

[0022] 5. The interaction between ionic waterborne modified alkyd emulsion and waterborne fluorocarbon resin results in a denser film with stronger penetration, and stronger comprehensive resistance to corrosion media, including anti-corrosion, anti-aging, and anti-soaking capabilities.

[0023] The water-based heavy-duty anti-corrosion coating for application with rust and residual paint film of the present invention has the advantages of safety, environmental protection, and application with rust and residual paint film. The coating can penetrate not only into the rust layer, but also into the residual paint film, providing safe, long-lasting, and easy-to-apply anti-corrosion protection and maintenance for steel products. Moreover, within the effective anti-corrosion period, the coating will not crack, peel, or flake off, and the steel products will no longer rust or re-rust, giving the steel products sustainable use value.

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 is a photograph of a rusted SPCC steel plate from Embodiment 1 of the present invention.

[0026] Figure 2 is a photograph of the rusted SPCC steel plate of Embodiment 1 of the present invention.

[0027] Figure 3 shows photos before and after the adhesion test of the heavy-duty anti-corrosion coating in Embodiment 1 of the present invention.

[0028] Figure 4 is a photograph of the test results of the neutral salt spray resistance of the heavy-duty anti-corrosion coating in Example 1 of the present invention.

[0029] Figure 5 is a photograph of the rusted SPCC steel plate of Embodiment 2 of the present invention.

[0030] Figure 6 is a photograph of the rusted SPCC steel plate of Embodiment 2 of the present invention.

[0031] Figure 7 shows photos before and after the adhesion test of the heavy-duty anti-corrosion coating in Embodiment 2 of the present invention.

[0032] Figure 8 is a photograph of the test results of the neutral salt spray resistance of the heavy-duty anti-corrosion coating in Example 2 of the present invention.

[0033] Figure 9 is a photograph of the rusted SPCC steel plate of Embodiment 3 of the present invention.

[0034] Figure 10 is a photograph of the rusted SPCC steel plate of Embodiment 3 of the present invention.

[0035] Figure 11 shows photos before and after the adhesion test of the third anti-corrosion coating of the present invention.

[0036] Figure 12 is a photograph of the test results of the neutral salt spray resistance of the anti-corrosion coating in Example 3 of the present invention. Detailed Implementation

[0037] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention are described in detail below with reference to examples. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified. The following examples specifically illustrate the content of the present invention, and the following description is not intended to limit the present invention. Example 1

[0038] This embodiment of the water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is prepared by weighing and mixing the following components evenly: 25 kg of acrylic modified alkyd emulsion, 5 kg of water-based fluorocarbon resin, 31 kg of deionized water, 10 kg of aluminum zinc phosphate, 13 kg of barium sulfate and zinc hydroxide, and nano-polyethylene wax powder (the mass ratio of barium sulfate to zinc hydroxide is 1:4, and the mass ratio of barium sulfate and zinc hydroxide to nano-polyethylene wax powder is 1:4), 2 kg of pentamethyldiethylenetriamine, 6 kg of silane coupling agent modified vermiculite, 5 kg of polypyrrole, 0.8 kg of sodium fatty alcohol polyoxyethylene ether sulfate, 0.4 kg of maleic acid, 1 kg of fumed silica, 0.3 kg of single-end vinyl modified polysiloxane defoamer, 0.3 kg of fluorocarbon wetting agent, 0.1 kg of vinyl-end modified polymethyltrifluoropropylsiloxane leveling agent, and 0.1 kg of polyacrylate dispersant. The heavy-duty anti-corrosion coating was prepared by mixing at 600 rpm and shearing at 800 rpm for 2 hours in a stainless steel container until homogeneous, and then filtering through a vacuum 200-mesh nylon mesh.

[0039] This embodiment describes the application of a water-based heavy-duty anti-corrosion coating to rusted SPCC steel plates with residual paint film.

[0040] First, a rust-bearing SPCC steel plate is prepared. The specific method is as follows: First, the SPCC steel plate is sandblasted, and then placed in a salt spray chamber for 2 days to allow the substrate surface to be covered with rust (as shown in Figure 1). The rust-bearing steel plate is taken out, brushed and rinsed with a brush, and then baked at (105±2)℃ for 1 hour. Then, the surface rust is removed by manually grinding with a wire brush, leaving firmly attached rust. The surface dust is blown away with high-pressure air to obtain the rust-bearing SPCC steel plate, as shown in Figure 2.

[0041] The heavy-duty anti-corrosion coating of this embodiment was applied to the prepared rusted SPCC steel plate using a 400μm coating rod. After coating, it was dried in an oven at 60°C for 2 hours. Then, an acrylic-modified alkyd emulsion topcoat was applied to the coating using a 150μm coating rod. After topcoat, it was dried in an oven at 60°C for 2 hours and then left at room temperature (25°C) for 168 hours to obtain the heavy-duty anti-corrosion coating. The dry film thickness was measured to be approximately 200μm using a thickness gauge.

[0042] The adhesion of the heavy-duty anti-corrosion coating was tested according to the national standard GB / T9286-2021. The photos before and after the test are shown in Figure 3. The coating adhesion was grade 0.

[0043] The flexibility of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1731-2020, and the result showed that the flexibility of the heavy-duty anti-corrosion coating was 1 mm. The impact resistance of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1732-2020, and the result showed that the impact resistance of the heavy-duty anti-corrosion coating was 50 cm. The neutral salt spray resistance performance of the heavy-duty anti-corrosion coating in this embodiment was tested according to national standard GB / T1771-2007. The photo is shown in Figure 4. After 2400 hours, some blistering occurred on the board surface, and the coating's neutral salt spray resistance time was 2400 hours. Example 2

[0044] This embodiment of the water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is prepared by weighing and mixing the following components evenly: 20 kg of acrylic modified alkyd emulsion, 10 kg of water-based fluorocarbon resin, 35 kg of deionized water, 5 kg of tetrasodium hydroxyethylidene diphosphonate, 10 kg of barium sulfate and zinc hydroxide, and nano-polyethylene wax powder (the mass ratio of barium sulfate to zinc hydroxide is 1:3, and the mass ratio of barium sulfate and zinc hydroxide to nano-polyethylene wax powder is 1:3), 5 kg of sodium p-dimethylaminoazobenzene carboxylate, 3 kg of silane coupling agent modified graphene, 8 kg of polyaniline, 0.7 kg of sodium alkyl glycerol ether sulfonate, 0.3 kg of β-primary oil amino acid, 2 kg of castor oil modified derivative, 0.2 kg of fluorocarbon modified polysiloxane defoamer, 0.2 kg of fluorocarbon wetting agent, 0.3 kg of modified polyacrylate copolymer leveling agent, and 0.3 kg of modified polycarboxylate copolymer sodium salt dispersant. The heavy-duty anti-corrosion coating was prepared by mixing at 600 rpm and shearing at 800 rpm for 2 hours in a stainless steel container until homogeneous, and then filtering through a vacuum 200-mesh nylon mesh.

[0045] The heavy-duty anti-corrosion coating of this embodiment is used to coat rusted SPCC steel plates.

[0046] First, a rust-bearing SPCC steel plate is prepared. The specific method is as follows: First, the SPCC steel plate is sandblasted, and then placed in a salt spray chamber for 2 days to allow the substrate surface to be covered with rust (as shown in Figure 5). The rust-bearing steel plate is taken out, brushed and rinsed with a brush, and then baked at (105±2)℃ for 1 hour. Then, the surface rust is removed by manually grinding with a wire brush, leaving firmly attached rust. The surface dust is blown away with high-pressure air to obtain the rust-bearing SPCC steel plate, as shown in Figure 6.

[0047] The heavy-duty anti-corrosion coating of this embodiment was applied to the prepared rusted SPCC steel plate using a 400μm coating rod. After coating, it was dried in an oven at 60°C for 2 hours. Then, an acrylic-modified alkyd emulsion topcoat was applied to the coating using a 150μm coating rod. After topcoat, it was dried in an oven at 60°C for 2 hours and then left at room temperature (25°C) for 168 hours to obtain the heavy-duty anti-corrosion coating. The dry film thickness was measured to be approximately 200μm using a thickness gauge.

[0048] The adhesion of the anti-corrosion coating was tested according to the national standard GB / T9286-2021. The photos before and after the test are shown in Figure 7. The coating adhesion was grade 0.

[0049] The flexibility of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1731-2020, and the result showed that the flexibility of the heavy-duty anti-corrosion coating was 1 mm. The impact resistance of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1732-2020, and the result showed that the impact resistance of the heavy-duty anti-corrosion coating was 50 cm. The neutral salt spray resistance performance of the heavy-duty anti-corrosion coating in this embodiment was tested according to national standard GB / T1771-2007. The photo is shown in Figure 8. After 3000 hours, some blistering occurred on the board surface, and the coating's neutral salt spray resistance time was 3000 hours. Example 3

[0050] This embodiment of the water-based heavy-duty anti-corrosion coating for application with rust and residual paint film is prepared by weighing and mixing the following components evenly: 28 kg of acrylic modified alkyd emulsion, 6 kg of water-based fluorocarbon resin, 25 kg of deionized water, 6 kg of modified aluminum tripolyphosphate and sodium dimethylphenylphosphonate (mass ratio of modified aluminum tripolyphosphate and sodium dimethylphenylphosphonate is 3:1), 20 kg of barium sulfate, zinc hydroxide, and nano-polyethylene wax powder (mass ratio of barium sulfate and zinc hydroxide is 1:6, and mass ratio of barium sulfate and zinc hydroxide to nano-polyethylene wax powder is 1:3), 3 kg of triethanolamine and sodium 6-acetaminopyridinecarboxylate (mass ratio of triethanolamine and sodium 6-acetaminopyridinecarboxylate is 2:1), and silane coupling agent modified vermiculite and silane coupling agent modified graphene (silane coupling agent modified vermiculite and silane coupling agent modified graphene). The following ingredients are listed: 4 kg of modified vermiculite and silane coupling agent-modified graphene (mass ratio 1:5), 6 kg of polythiophene, 0.2 kg of sodium fatty alcohol polyoxyethylene ether sulfate and sodium p-methoxy fatty amide benzenesulfonate (mass ratio 1:1), 0.1 kg of maleic acid and β-primary oil amino acids (mass ratio 1:3), 1.1 kg of fumed silica and castor oil modified derivatives (mass ratio 3:1), 0.1 kg of fluorocarbon modified polysiloxane defoamer, 0.1 kg of fluorocarbon wetting agent, 0.2 kg of polyether modified polydimethylsiloxane leveling agent, and 0.2 kg of modified polycarboxylic acid copolymer ammonium salt dispersant. The heavy-duty anti-corrosion coating was prepared by mixing at 600 rpm and shearing at 800 rpm for 2 hours in a stainless steel container until homogeneous, and then filtering through a vacuum 200-mesh nylon mesh.

[0051] The heavy-duty anti-corrosion coating of this embodiment is used to coat rusted SPCC steel plates.

[0052] First, a rust-bearing SPCC steel plate is prepared. The specific method is as follows: First, the SPCC steel plate is sandblasted, and then placed in a salt spray chamber for 2 days to allow the substrate surface to be covered with rust (as shown in Figure 9). The rust-bearing steel plate is taken out, brushed and rinsed with a brush, and then baked at (105±2)℃ for 1 hour. Then, the surface rust is removed by manually grinding with a wire brush, leaving firmly attached rust. The surface dust is blown away with high-pressure air to obtain the rust-bearing SPCC steel plate, as shown in Figure 10.

[0053] The heavy-duty anti-corrosion coating of this embodiment was applied to the prepared rusted SPCC steel plate using a 400μm coating rod. After coating, it was dried in an oven at 60°C for 2 hours. Then, an acrylic-modified alkyd emulsion topcoat was applied to the coating using a 150μm coating rod. After topcoat, it was dried in an oven at 60°C for 2 hours and then left at room temperature (25°C) for 168 hours to obtain the heavy-duty anti-corrosion coating. The dry film thickness was measured to be approximately 200μm using a thickness gauge.

[0054] The adhesion of the anti-corrosion coating was tested according to the national standard GB / T9286-2021. The photos before and after the test are shown in Figure 11. The coating adhesion was grade 0.

[0055] The flexibility of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1731-2020, and the result showed that the flexibility of the heavy-duty anti-corrosion coating was 1 mm. The impact resistance of the heavy-duty anti-corrosion coating in this embodiment was tested according to standard GB / T1732-2020, and the result showed that the impact resistance of the heavy-duty anti-corrosion coating was 50 cm. The neutral salt spray resistance performance of the heavy-duty anti-corrosion coating in this embodiment was tested according to national standard GB / T1771-2007. The photo is shown in Figure 12. After 2600 h, some blistering occurred on the board surface, and the coating's neutral salt spray resistance time was 2600 h.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film, characterized in that, The ingredients, calculated by weight, include: 20-28 parts of ionic waterborne modified alkyd emulsion, 5-10 parts of waterborne fluorocarbon resin, 25-35 parts of deionized water, 5-10 parts of anti-rust pigment, 10-20 parts of filler, 2-5 parts of flash rust inhibitor, 3-6 parts of salt spray resistant additive, 5-8 parts of self-healing additive, 0.2-0.8 parts of penetrant, 0.1-0.4 parts of corrosion inhibitor, 1-2 parts of thixotropic agent, and 0.4-1.2 parts of additives.

2. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The ionic aqueous modified alkyd emulsion is an acrylic acid modified alkyd emulsion.

3. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The rust-preventive pigment is a phosphate and / or an organophosphonate; the filler is barium sulfate, zinc hydroxide and nano-polyethylene wax powder, the mass ratio of barium sulfate to zinc hydroxide is 1:(3~6), and the mass ratio of the sum of the masses of barium sulfate and zinc hydroxide to the mass of nano-polyethylene wax powder is 1:(3~6); the flash rust inhibitor is an organic amine and / or an aminocarboxylate.

4. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 3, characterized in that, The phosphate is aluminum zinc phosphate or polyphosphate, the organophosphonate is tetrasodium hydroxyethylidene diphosphonate or sodium dimethylphenylphosphonate, the organic amine is pentamethyldiethylenetriamine or triethanolamine, and the aminocarboxylate is sodium p-dimethylaminoazobenzoic acid or sodium 6-acetaminopyridinecarboxylate.

5. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The salt spray resistant additive is modified vermiculite and / or modified graphene.

6. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The self-healing agent is a nano-conductive polymer such as polyaniline, polypyrrole, or polythiophene; the penetrant is sodium fatty alcohol polyoxyethylene ether sulfate and / or sulfonic acid anionic surfactant.

7. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The corrosion inhibitor is maleic acid and / or amino acids.

8. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, The thixotropic agent is fumed silica and / or a castor oil-modified derivative.

9. The water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film as described in claim 1, characterized in that, Additives include modified polysiloxane defoamers, low surface tension wetting agents, leveling agents, and dispersants.

10. A water-based heavy-duty anti-corrosion coating for application to areas with rust and residual paint film, as described in claim 9, characterized in that, The modified polysiloxane defoamer is a single-end vinyl-modified polysiloxane defoamer or a fluorocarbon-modified polysiloxane defoamer; the low surface tension wetting agent is a fluorocarbon wetting agent; the leveling agent is a vinyl-end modified polymethyltrifluoropropylsiloxane leveling agent, a modified polyacrylate copolymer leveling agent, or an organosilicon leveling agent; and the dispersant is a sodium polycarboxylate, an ammonium polycarboxylate, or a polymeric dispersant.

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