A steel bar for reinforced concrete structures, a composite anti-corrosion coating on its surface, and a preparation method thereof.

Abstract

This invention relates to reinforcing bars for reinforced concrete structures, a composite anti-corrosion coating on their surface, and a preparation method thereof. The composite anti-corrosion coating on the surface of the reinforcing bars of this invention comprises, sequentially from the surface of the reinforcing bars outwards, a thermally sprayed coating and a sealing layer. This invention employs a two-layer composite structure to form a composite anti-corrosion layer with properties such as corrosion resistance, isolation, wear resistance, and resistance to strong alkalis.

Description

Technical Field

[0001] This invention belongs to the field of corrosion protection technology, specifically relating to a steel bar for reinforced concrete structures, a composite anti-corrosion coating on its surface, and a preparation method thereof. Background Technology

[0002] Reinforced concrete is commonly used in large-scale engineering projects such as bridge construction, which often require significant load-bearing capacity. If the quality of reinforced concrete structures is substandard, it can pose a serious threat to the lives and property of the public. For the reinforcing steel bars within concrete, corrosion can occur, often resulting in severe corrosion of the entire steel bar or only a portion of it. Once the reinforcing steel bars in reinforced concrete are severely corroded, the stability of the concrete will be compromised.

[0003] To prevent corrosion of steel bars in reinforced concrete structures, existing technologies employ epoxy coatings to coat the steel bars, using the integrity of the paint film to isolate them from external corrosive media. However, with this method, once the paint film is partially damaged, corrosive media can penetrate the damaged area and rapidly corrode the substrate. Moisture quickly enters the space between the paint film and the substrate, causing the paint film to peel off, blister, and eventually break completely.

[0004] Chinese patent application CN 111020447A discloses a thermally sprayed rare-earth alloy clad steel bar, wherein the Al content in the thermally sprayed coating is 15-40%, and the salt spray resistance time is only 800 hours. Chinese patent application CN 110923616A discloses a thermally sprayed rare-earth aluminum alloy clad steel bar, wherein the Zn content in the thermally sprayed coating is 15-40%, and the salt spray resistance time is only 800 hours. Summary of the Invention

[0005] To address the shortcomings of the prior art, this invention provides a steel bar for reinforced concrete structures, a composite anti-corrosion coating on its surface, and a preparation method thereof.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] On one hand, this invention provides a composite anti-corrosion coating for the surface of reinforcing bars in reinforced concrete structures, comprising a thermally sprayed coating and a sealing layer sequentially extending outwards from the surface of the reinforcing bars. This invention employs a two-layer composite structure to jointly form a composite anti-corrosion layer with properties such as corrosion resistance, isolation, wear resistance, and resistance to strong alkalis.

[0008] Preferably, the thermal spray coating comprises, by weight percentage, 0.5-10% Ti. 10 Al 90 Powder, 0.5-10% AlMg 2.50.1-0.8% rare earth metals, 0.5-10% composite ceramic micro powder, 0.5-10% strong alkali resistant nanomaterials, and the balance is zinc.

[0009] Preferably, the thermal spray coating comprises, by weight percentage, the following components: 1-5% Ti 10 Al 90 Powder, 1-5% AlMg 2.5 0.1-0.5% rare earth metals, 1-5% composite ceramic micro powder, 1-5% strong alkali resistant nanomaterials, and the balance is zinc.

[0010] Preferably, the Ti 10 Al 90 The powder, by mass percentage, contains 10% titanium and 90% aluminum.

[0011] Preferably, the AlMg 2.5 By mass percentage, magnesium accounts for 2.5% and aluminum accounts for 97.5%.

[0012] Preferably, the rare earth metal is selected from one or two of La, Ce and Sc, with Ce or Sc being the most preferred.

[0013] Preferably, the composite ceramic micropowder is composed of silicon dioxide and aluminum oxide in a mass ratio of 1:2 to 1:3, wherein the particle size of both silicon dioxide and aluminum oxide is 1 to 5 μm. This component further improves the hardness and wear resistance of the thermal spray coating.

[0014] Preferably, the alkali-resistant nanomaterial is selected from one or more of nano-alumina VK-L30, nano-zirconia VK-R30, nano-cerium oxide VK-CEO2, nano-silica VK-SP30, and nano-titanium oxide VK-TO2H. This component further improves the alkali resistance of the thermal spray coating and enhances the interfacial bonding with concrete.

[0015] Preferably, the thermal spray coating is formed by spraying with thermal spray filament, and the preparation method of the thermal spray filament is as follows:

[0016] (1) Prepare the ingredients according to the above-mentioned thermal spray coating formula, transfer them into a hollow induction furnace for melting, the melting temperature is 600-700℃, hold for 2.0-2.5h, stir thoroughly, let stand for 2.5-3.5h, remove the slag and transfer to a heat-preserving crystallization furnace, perform horizontal continuous casting under the condition of temperature not lower than 650℃, and obtain rod-shaped rare earth zinc aluminum magnesium titanium alloy blanks with a diameter of 10mm-50mm;

[0017] (2) The rod-shaped rare earth zinc-aluminum-magnesium-titanium alloy blank prepared in step (1) is subjected to homogenization annealing at 280℃-340℃ for 1.0-2.0h, and then drawn 3-8 times at a drawing speed of 0.5mm / s-4.0mm / s to reduce the diameter to 2-3mm.

[0018] Preferably, the sealing layer is formed by drying an aqueous sealing agent;

[0019] Preferably, the aqueous sealant comprises, by weight, the following components: 17-38 parts of cationic polyurethane resin emulsion, 18-38 parts of nonionic polyurethane resin emulsion, 18-35 parts of deionized water, 0.2-3.0 parts of wetting and dispersing agent, 5-15 parts of film-forming aid, 0.2-2.0 parts of defoamer, 0.1-1.0 parts of leveling agent, 0.1-2.0 parts of thickener, 2-18 parts of pigment, 0.05-0.8 parts of pH adjuster, 0.05-1.5 parts of antioxidant, and 0.2-2.5 parts of rust inhibitor.

[0020] Preferably, the aqueous sealant comprises, by weight, the following components: 20-35 parts of cationic polyurethane resin emulsion, 20-35 parts of nonionic polyurethane resin emulsion, 20-30 parts of deionized water, 0.5-2.5 parts of wetting and dispersing agent, 6-11 parts of film-forming aid, 0.3-1.5 parts of defoamer, 0.1-0.5 parts of leveling agent, 0.5-1.5 parts of thickener, 5-15 parts of pigment, 0.1-0.5 parts of pH adjuster, 0.1-1.0 parts of antioxidant, and 0.5-2 parts of rust inhibitor.

[0021] Preferably, the cationic polyurethane resin emulsion is selected from one or more of BW-8700 and PU7305.

[0022] Preferably, the nonionic polyurethane resin emulsion is selected from one or more of PU7301 and MR871.

[0023] Preferably, the solid content of the cationic polyurethane resin emulsion or the nonionic polyurethane resin emulsion is 40%.

[0024] Preferably, the wetting and dispersing agent is selected from one or more of phosphate ester surfactants and multi-branched alcohol polyethers;

[0025] Preferably, the phosphate ester surfactant is selected from one or more of the following: Viktor LFS-209 and Viktor LFS-210 wetting and dispersing agents;

[0026] Preferably, the multi-branched alcohol polyether is selected from Viktor LFS-090 wetting and dispersing agent;

[0027] Preferably, the film-forming aid is selected from one or more of dodecyl alcohol ester, propylene glycol phenyl ether, and dipropylene glycol butyl ether;

[0028] Preferably, the defoamer is selected from one or more polyethers and silicones;

[0029] Preferably, the polyether defoamer is selected from... Foamic-028 polyether defoamer;

[0030] Preferably, the silicone-based defoamer is selected from... Foamic-041 silicone defoamer;

[0031] Preferably, the leveling agent is selected from one or more of organosilicon and modified organosilicon, and more preferably... SI-800 One or more of Superwet 4000;

[0032] Preferably, the thickener is selected from one or more of cellulose ethers and associative polyurethanes;

[0033] Preferably, the pigment is selected from one or more of iron oxide ash, gray titanium powder, and mica iron oxide;

[0034] Preferably, the pH adjuster is selected from one or more of formic acid, acetic acid, and hydrochloric acid;

[0035] Preferably, the antioxidant is selected from one or more of the following: multi-functional hindered phenolic antioxidants, phosphites, and phenolic-phosphite complexes;

[0036] Preferably, the rust inhibitor is selected from one or more of sodium sulfonate, di-n-butyl phosphite, fatty acid amide, borate amine, and sodium benzoate.

[0037] Preferably, the aqueous sealant is prepared as follows:

[0038] (1) The cationic polyurethane resin emulsion, nonionic polyurethane resin emulsion, deionized water, wetting and dispersing agent, film-forming aid, defoamer, leveling agent, thickener, antioxidant, and rust inhibitor are mixed in a reactor and stirred at 500-1000 r / min for 60-90 minutes. The pH adjuster is slowly added and the mixture is stirred at 500-1000 r / min for 30-60 minutes to ensure uniform dispersion of the slurry and obtain a mixed slurry.

[0039] (2) Add pigment to the mixed slurry obtained in step (1), grind it, and filter it through a 200-mesh filter to obtain the final product.

[0040] Preferably, the thickness of the thermal spray coating is 105–210 μm.

[0041] Preferably, the thickness of the sealing layer is 5–10 μm.

[0042] Preferably, the total thickness of the anti-corrosion coating is 110–220 μm.

[0043] This invention addresses the corrosion protection of reinforcing bars in reinforced concrete structures by proposing a composite anti-corrosion layer consisting of a thermal spray coating and a sealing layer on the surface of the reinforcing bars. The sealing layer of a certain thickness serves as the first protective layer, providing physical shielding and corrosion protection. Even if the sealing layer is partially damaged later, the thermal spray coating preferentially undergoes a chemical reaction to generate dense compounds of zinc and aluminum, preventing external corrosive media from penetrating the reinforcing bars and extending their service life.

[0044] On the other hand, the present invention provides a method for preparing a composite anti-corrosion coating on the surface of steel bars for reinforced concrete structures, the method comprising the following steps:

[0045] (1) Shot blasting with steel shot with a diameter of 0.1 to 0.3 mm, or sandblasting with quartz sand with a diameter of 0.6 mm to 1.18 mm, to remove dust, impurities, oxide scale and rust adhering to the surface of the steel bar, exposing the metal surface of the steel bar, so that the surface roughness of the steel bar after treatment reaches Sa2.5 or above, and a pre-treated steel bar is obtained.

[0046] (2) Preheat the steel bars that have been pretreated in step (1) to 350-450°C, maintain the temperature, and immediately spray the aforementioned thermal spray coating material with a thermal spray gun within 0.5 hours to obtain steel bars with a thermal spray coating.

[0047] (3) Immerse or spray the steel bar with the thermal spray coating obtained in step (2) into or spray it with a water-based sealant and dry it to obtain the final product.

[0048] Preferably, in step (2), the thermal spraying method includes the following spraying methods: flame spraying, electric arc spraying, supersonic electric arc spraying, high-power electric arc spraying, multi-atomization electric arc spraying, dual-atomization electric arc spraying, and supersonic flame spraying. After spraying, the surface should have fine and uniform particles, and defects such as peeling, blistering, large droplets, runs, cracks, and flaking are not allowed.

[0049] Preferably, in step (2), if immersion is used, the immersion time is 20 to 40 seconds; if spraying is used, the spraying is done once.

[0050] Compared with the prior art, this application has at least the following beneficial technical effects:

[0051] This invention utilizes a thermal spray coating on the surface of reinforcing steel, such as a low-aluminum-content zinc-aluminum rare-earth composite coating. This coating exhibits high corrosion resistance, exceptional wear resistance, bending strength, and resistance to strong alkalis, further enhancing the durability of reinforced concrete. The addition of composite ceramic micropowder further improves the hardness and wear resistance of the thermally sprayed zinc-aluminum coating, while the addition of alkali-resistant nanomaterials further enhances its resistance to strong alkalis and strengthens the interfacial bond with concrete. This invention protects reinforcing steel through a sacrificial anode mechanism. Even if the coating has micropores, defects, or other damage, the surrounding active metals will react first, and the resulting products will adhere to the surface, protecting the substrate from external corrosive media. Therefore, the thermally sprayed coating provides longer-lasting and reliable protection for reinforcing steel, with a corrosion protection lifespan several times that of existing coating technologies.

[0052] This invention further forms a sealing layer on the outside of the thermal spray coating. This sealing layer has the effects of blocking water, oxygen, and gas, and is environmentally friendly and pollution-free. It can enhance the anti-corrosion performance of the thermal spray coating and improve the durability and weather resistance of the composite anti-corrosion steel bars. Compared with other water-based resins, such as water-based acrylic resin and water-based epoxy resin, the water-based sealant of this invention has excellent mechanical properties and exhibits better impact resistance and bending resistance after forming a film on the steel bar surface. Detailed Implementation

[0053] The present invention will be described below with reference to specific embodiments. Those skilled in the art will understand that these embodiments are for illustrative purposes only and do not limit the scope of the invention in any way. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods. Unless otherwise specified, the raw materials, reagents, and other materials used in the following embodiments are commercially available products. The purchase details of some reagents and raw materials are as follows:

[0054] (1)Ti 10 Al 90 Powder: Shanghai Gelin Technology Co., Ltd.

[0055] (2) AlMg 2.5 Bar stock: Dongguan Chang'an Derui Metal Materials Business Department

[0056] (3) Composite ceramic micro powder: Shanghai Huijingya Nanomaterials Co., Ltd.

[0057] (4) Alkali-resistant nanomaterials: Xuancheng Jingna Environmental Protection Technology Co., Ltd.

[0058] (5) Cationic waterborne polyurethane resin emulsion BW-8700: Zibo Baowei New Material Technology Co., Ltd.

[0059] (6) PU7305 cationic waterborne polyurethane resin emulsion, PU7301 nonionic waterborne polyurethane resin emulsion: Shanghai Belt New Material Technology Co., Ltd.

[0060] (7) Nonionic waterborne polyurethane resin emulsion MR871: Dongguan Baojing Chemical Co., Ltd.

[0061] (8) Wetting and dispersing agent Vicler LFS-209 / 210, Wetting and dispersing agent Vicler LFS-090 Foamic-041 silicone defoamer Foamic-028 polyether defoamer SI-800 silicone-based surfactant (leveling agent) Superwet4000 Series Leveling Agent: Tianjin Hepufele New Material Co., Ltd.

[0062] (9) High-efficiency antioxidant 1010: Anhui Youfeng New Material Technology Co., Ltd.

[0063] (10) Antioxidant CYANOX 2777: Cytec Industries, Inc., USA

[0064] Example 1: Preparation method of water-based sealant

[0065] The preparation method of the aqueous sealing agent of the present invention is as follows:

[0066] (1) The cationic polyurethane resin emulsion, nonionic polyurethane resin emulsion, deionized water, wetting and dispersing agent, film-forming aid, defoamer, leveling agent, thickener, antioxidant, and rust inhibitor are mixed in a reactor and stirred at 650 r / min for 70 minutes. Acetic acid is slowly added and stirred at 700 r / min for 50 minutes to make the slurry uniformly dispersed and obtain a mixed slurry.

[0067] (2) Add pigment iron oxide ash to the mixed slurry obtained in step (1) above to ensure that it matches the color of the concrete, grind it, filter it through a 200-mesh filter, and package it to obtain a water-based sealant.

[0068] Unless otherwise specified, the following examples and comparative examples all use this method to prepare aqueous sealing agents.

[0069] Example 2: Preparation method of composite anti-corrosion coating on the surface of steel bars for reinforced concrete structures

[0070] The method for preparing the composite anti-corrosion coating on the surface of steel bars for reinforced concrete structures according to the present invention is as follows:

[0071] (1) Shot blasting with steel shot with a diameter of 0.2 mm or sandblasting with quartz sand with a diameter of 1.18 mm is used to remove dust, impurities, oxide scale and rust adhering to the surface of the steel bar, exposing the metal surface of the steel bar, so that the surface roughness of the steel bar substrate reaches Sa2.5 or above after treatment, and the pre-treated steel bar is obtained.

[0072] (2) Preheat the pretreated steel bars in step (1) to 385°C, maintain the temperature, and immediately apply the thermal spray coating material using a thermal spray gun within 0.5 hours to obtain steel bars with thermal spray coating.

[0073] (3) Immerse the steel bar with thermal spray coating obtained in step (2) for 30 seconds and dry it to obtain the final product.

[0074] In step (2), the thermal spraying gun is used for spraying, which is an electric arc spraying. After spraying, the surface should have fine and uniform particles, and defects such as peeling, blistering, large droplets, runs, cracks, and flaking are not allowed.

[0075] Examples 3-7 and Comparative Examples 1-6: Thermal spray coatings and their physical properties when applied to reinforcing steel bars

[0076] The raw material ratios and physical and mechanical properties of the thermal spray coatings in Examples 3-7 and Comparative Examples 1-6 are shown in Table 1.

[0077] Table 1. Formulations and physical and mechanical properties of Examples 3-7 and Comparative Examples 1-6

[0078]

[0079]

[0080] Examples 8-12 and Comparative Examples 7-9: The formulation ratios of water-based sealants and their physical properties when applied to reinforcing bars

[0081] The formulations of the water-based sealant raw materials for Examples 8-12 and Comparative Examples 7-9 are shown in Table 2. The physical and mechanical properties of the water-based sealant applied to the thermal spray coating of Example 7 are shown in Table 2.

[0082] Table 2. Sealing agent formulations and composite layer performance of Examples 8-12 and Comparative Examples 7-9

[0083]

[0084]

[0085]

[0086] The neutral salt spray resistance test shall be conducted in accordance with GB / T1771-2007; the alkali resistance test shall be conducted in accordance with GB / T1690-2010 to determine whether the appearance of the coating changes; the adhesion of the sprayed coating shall be conducted in accordance with GB / T5210-2006; the hardness of the sprayed coating shall be conducted in accordance with GB / T4340.1; the 180° bending resistance shall be conducted in accordance with GB / T232-2010; the bond strength between steel bars and concrete and the impact resistance test shall be conducted in accordance with JG / T502-2016.

[0087] The results in Tables 1 and 2 show that the thermally sprayed coatings in Examples 3-7 exhibited no change in neutral salt spray resistance (≥5200h), hardness (0.1HV≥230), coating adhesion (≥10MPa), and strong alkali resistance (≥5100h). In Comparative Example 1, the amount of strong alkali-resistant nanomaterials was relatively small, resulting in poor alkali resistance of the coating. In Comparative Example 2, the amount of alumina in the composite ceramic micropowder was relatively large, leading to lower coating adhesion. In Comparative Example 3, Ti... 10 Al 90 The amount used was too low, and the trace amount of Al in the coating could not protect the coating, resulting in poor resistance to neutral salt spray. In Comparative Example 4, Fe2O3 was used instead of Al2O3, and the resistance to neutral salt spray and other properties were poor. In Comparative Example 5, Fe2O3 was used instead of SiO2, and the resistance to neutral salt spray and other properties were poor. In Comparative Example 6, nanodiamond powder was used instead of strong alkali resistant nanomaterials, and the coating hardness and adhesion were low.

[0088] In Examples 8-12, the composite coatings exhibited no change in resistance to neutral salt spray (≥5200h), strong alkali (≥5100h), no cracking after 180° bending, no change in impact resistance, and neutral salt spray resistance after impact >4500h. The 28-day bond strength between the steel reinforcement and concrete was ≥12MPa. In Comparative Example 7, the amount of nonionic waterborne polyurethane resin emulsion was relatively small, resulting in poorer resistance to bending and neutral salt spray. In Comparative Example 8, the amount of rust inhibitor was relatively small, resulting in poorer resistance to neutral salt spray and post-impact neutral salt spray. In Comparative Example 9, the amount of cationic waterborne polyurethane resin was relatively small, resulting in poorer resistance to bending and neutral salt spray.

Claims

1. A composite anti-corrosion coating on the surface of reinforcing bars for reinforced concrete structures, comprising a thermal spray coating and a sealing layer in sequence from the surface of the reinforcing bars for reinforced concrete structures outwards; in, The thermal spray coating comprises, by weight percentage, the following components: 0.5–10% Ti. 10 Al 90 Powder, 0.5-10% AlMg 2.5 0.1-0.8% rare earth metals, 0.5-10% composite ceramic micro powder, 0.5-10% strong alkali resistant nanomaterials, balance zinc; The sealing layer is formed by drying an aqueous sealant. The aqueous sealant, by weight, comprises the following components: 17-38 parts of cationic polyurethane resin emulsion, 18-38 parts of nonionic polyurethane resin emulsion, 18-35 parts of deionized water, 0.2-3.0 parts of wetting and dispersing agent, 5-15 parts of film-forming aid, 0.2-2.0 parts of defoamer, 0.1-1.0 parts of leveling agent, 0.1-2.0 parts of thickener, 2-18 parts of pigment, 0.05-0.8 parts of pH adjuster, 0.05-1.5 parts of antioxidant, and 0.2-2.5 parts of rust inhibitor.

2. The composite anti-corrosion coating according to claim 1, wherein, The thermal spray coating comprises, by weight percentage, the following components: 1-5% Ti 10 Al 90 Powder, 1-5% AlMg 2.5 0.1-0.5% rare earth metals, 1-5% composite ceramic micro powder, 1-5% strong alkali resistant nanomaterials, and the balance is zinc.

3. The composite anti-corrosion coating according to claim 1, wherein, The Ti 10 Al 90 The powder, by mass percentage, contains 10% titanium and 90% aluminum.

4. The composite anti-corrosion coating according to claim 1, wherein, The AlMg 2.5 By mass percentage, magnesium accounts for 2.5% and aluminum accounts for 97.5%.

5. The composite anti-corrosion coating according to claim 1, wherein, The rare earth metal is selected from one or two of La, Ce, and Sc.

6. The composite anti-corrosion coating according to claim 1, wherein, The rare earth metal is Ce or Sc.

7. The composite anti-corrosion coating according to claim 1, wherein, The composite ceramic powder is composed of silicon dioxide and aluminum oxide in a mass ratio of 1:2 to 1:3, wherein the particle size of silicon dioxide and aluminum oxide is 1 to 5 μm.

8. The composite anti-corrosion coating according to claim 1, wherein, The alkali-resistant nanomaterial is selected from one or more of the following: nano-alumina VK-L30, nano-zirconia VK-R30, nano-cerium oxide VK-CE02, nano-silicon oxide VK-SP30, and nano-titanium oxide VK-T02H.

9. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The thermal spray coating is formed by spraying with thermal spray filament, and the preparation method of the thermal spray filament is as follows: (1) Prepare the ingredients according to the above-mentioned thermal spray coating formula, transfer them into a hollow induction furnace for melting, the melting temperature is 600-700℃, hold for 2.0-2.5h, stir thoroughly, let stand for 2.5-3.5h, remove the slag and transfer to a heat-preserving crystallization furnace, perform horizontal continuous casting under the condition of temperature not lower than 650℃, and obtain rod-shaped rare earth zinc aluminum magnesium titanium alloy blanks with a diameter of 10mm-50mm; (2) The rod-shaped rare earth zinc-aluminum-magnesium-titanium alloy blank prepared in step (1) is subjected to homogenization annealing at 280℃-340℃ for 1.0-2.0h, and then drawn 3-8 times at a drawing speed of 0.5mm / s-4.0mm / s to reduce the diameter to 2-3mm.

10. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The aqueous sealant, by weight, comprises the following components: 20-35 parts of cationic polyurethane resin emulsion, 20-35 parts of nonionic polyurethane resin emulsion, 20-30 parts of deionized water, 0.5-2.5 parts of wetting and dispersing agent, 6-11 parts of film-forming aid, 0.3-1.5 parts of defoamer, 0.1-0.5 parts of leveling agent, 0.5-1.5 parts of thickener, 5-15 parts of pigment, 0.1-0.5 parts of pH adjuster, 0.1-1.0 parts of antioxidant, and 0.5-2 parts of rust inhibitor.

11. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The cationic polyurethane resin emulsion is selected from one or more of BW-8700 and PU7305.

12. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The nonionic polyurethane resin emulsion is selected from one or more of PU7301 and MR871.

13. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The solid content of the cationic polyurethane resin emulsion or the nonionic polyurethane resin emulsion is 40%.

14. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The wetting and dispersing agent is selected from one or more of phosphate ester surfactants and multi-branched alcohol polyethers.

15. The composite anti-corrosion coating according to claim 14, wherein, The phosphate ester surfactant is selected from one or more of the Wetting and Dispersing Agents Vectr LFS-209 and Vectr LFS-210.

16. The composite anti-corrosion coating according to claim 14, wherein, The multi-branched alcohol polyether is selected from Viktor LFS-090 wetting and dispersing agent.

17. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The film-forming aid is selected from one or more of dodecyl alcohol ester, propylene glycol phenyl ether, and dipropylene glycol butyl ether.

18. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The defoamer is selected from one or more of polyether defoamers and silicone defoamers.

19. The composite anti-corrosion coating according to claim 18, wherein, The polyether defoamer is selected from Tuyile. Foamic-028 polyether defoamer.

20. The composite anti-corrosion coating according to claim 18, wherein, The silicone-based defoamer is selected from TuYiLe. Foamic-041 silicone defoamer.

21. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The leveling agent is selected from one or more of organosilicon and modified organosilicon.

22. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The leveling agent is Tuyile. SI-800, Ketule One or more of the Superwet 4000.

23. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The thickener is selected from one or more of cellulose ethers and associative polyurethanes.

24. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The pigment is selected from one or more of iron oxide ash, gray titanium powder, and mica iron oxide.

25. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The pH adjuster is selected from one or more of formic acid, acetic acid, and hydrochloric acid.

26. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The antioxidant is selected from one or more of the following: multi-functional hindered phenolic antioxidants, phosphites, and phenolic-phosphite complexes.

27. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The rust inhibitor is selected from one or more of sodium sulfonate, di-n-butyl phosphite, fatty acid amide, borate amine, and sodium benzoate.

28. The composite anti-corrosion coating according to any one of claims 1 to 8, wherein, The preparation method of the aqueous sealant is as follows: (1) The cationic polyurethane resin emulsion, nonionic polyurethane resin emulsion, deionized water, wetting and dispersing agent, film-forming aid, defoamer, leveling agent, thickener, antioxidant, and rust inhibitor are mixed in a reactor and stirred at 500-1000 r / min for 60-90 minutes. The pH adjuster is slowly added and the mixture is stirred at 500-1000 r / min for 30-60 minutes to ensure uniform dispersion of the slurry and obtain a mixed slurry. (2) Add pigment to the mixed slurry obtained in step (1), grind it, and filter it through a 200-mesh filter to obtain the final product.

29. The composite anti-corrosion coating according to claim 28, wherein, The thickness of the thermal spray coating is 105–210 μm.

30. The composite anti-corrosion coating according to claim 28, wherein, The thickness of the sealing layer is 5–10 μm.

31. The composite anti-corrosion coating according to claim 28, wherein, The total thickness of the anti-corrosion coating is 110–220 μm.

Images