A zinc-rich coating, its preparation method and use

Abstract

The application discloses a zinc-rich coating and a preparation method and application thereof, and belongs to the technical field of coatings.The zinc-rich coating comprises 20-40 parts of modified zinc powder, 55-60 parts of acrylic resin varnish, 4-6 parts of aluminum powder, 2-6 parts of nanoparticles, 0.3-0.5 parts of a dispersing agent and 0.2-0.5 parts of a defoaming agent.The modified zinc powder is obtained by modifying zinc powder with a modifying solution, and the modifying solution comprises sodium molybdate, trisodium phosphate, sodium acetate and deionized water.The acrylic resin varnish is composed of acrylic resin powder, ethyl acetate and dimethylbenzene.In the preparation, the sodium molybdate, trisodium phosphate and sodium acetate are dissolved in the deionized water, nitric acid is added to adjust the pH to 7.2+ / -0.1 after complete dissolution, then the zinc powder is added, and magnetic stirring is carried out until the solution becomes light blue, then the modified zinc powder is obtained by filtering, drying and grinding screening.The acrylic resin powder, ethyl acetate and dimethylbenzene are uniformly mixed to obtain the acrylic resin varnish.The modified zinc powder, aluminum powder and nanoparticles are added into the acrylic resin varnish and mixed, then the dispersing agent and the defoaming agent are added and uniformly mixed to obtain the zinc-rich coating.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion coating technology, and relates to zinc-rich coatings, particularly to a zinc-rich coating and its preparation method and application. Background Technology

[0002] The economic losses caused by corrosion of steel materials account for about 2-3% of the GDP of various countries. One-third of these losses come from marine corrosion. Corrosive media such as marine atmosphere, seawater and microorganisms can cause severe corrosion damage to the surface of marine steel components. Among these corrosions, 20% are caused by microorganisms. Microbial corrosion has been recognized as an important form of corrosion damage to metal structures such as marine ships, oil platforms and subsea pipelines. Preparing protective coatings on the surface of metal substrates is one of the simplest and most effective means of dealing with marine corrosion.

[0003] Currently, the surfaces of metal components in marine environments are often protected against corrosion by coating them with antifouling and anticorrosive coatings. Dacromet coatings are widely used in marine environments due to their low raw material cost, applicability to various complex parts, and advantages such as no hydrogen embrittlement, good heat resistance, and corrosion resistance. However, traditional Dacromet coatings are primarily composed of zinc powder, aluminum powder, chromate, and deionized water, which introduces several serious drawbacks. Firstly, while most commercially available Dacromet coatings meet usage standards, the volatilization of toxic hexavalent chromic anhydride remaining in the coating during service is unavoidable, posing significant safety hazards to human health and the marine ecosystem. Secondly, the Dacromet coating application process requires pretreatment of the substrate surface, followed by a spray-baking-second spray-baking-drying process, which is complex and costly. Furthermore, ordinary Dacromet coatings do not significantly inhibit marine microbial corrosion. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the existing technology, the purpose of this invention is to provide a zinc-rich coating, its preparation method and application. The zinc-rich coating of this invention has good adhesion, flexibility and corrosion resistance, and the coating does not contain toxic chromate substances, which can effectively reduce pollution to the marine ecological environment. At the same time, after adding a specific proportion of nano ZnO particles, the coating exhibits better comprehensive protective performance under seawater immersion test. The preparation process of the coating of this invention is simple and can effectively reduce construction costs.

[0005] The technical solution of this invention is implemented as follows:

[0006] A zinc-rich coating comprises 20-40 parts modified zinc powder, 55-60 parts acrylic resin varnish, 4-6 parts aluminum powder, 2-6 parts nanoparticles; 0.3-0.5 parts dispersant; and 0.2-0.5 parts defoamer.

[0007] The modified zinc powder is obtained by modifying zinc powder with a modifying liquid, which includes sodium molybdate, trisodium phosphate, sodium acetate and deionized water.

[0008] The acrylic resin varnish is composed of acrylic resin powder, ethyl acetate and xylene.

[0009] Furthermore, the mass-to-volume ratio of sodium molybdate, trisodium phosphate, sodium acetate, and deionized water in the modified solution is 5–7 g: 3–5 g: 2–4 g: 100 mL.

[0010] Furthermore, the mass ratio of zinc powder to sodium molybdate is 2 to 3:1.

[0011] Furthermore, the mass ratio of acrylic resin powder, ethyl acetate, and xylene is 2–3:3–5:4–6.

[0012] Furthermore, the nanoparticles are nano-ZnO particles with a particle size of 30±10nm; the zinc powder and aluminum powder are flake-shaped with a particle size of 30±10μm.

[0013] Furthermore, the dispersant is Tween 20 (polysorbate-20); the defoamer is one of silicone oil-based or organosilicon-based defoamers.

[0014] The method for preparing a zinc-rich coating described above includes the following steps:

[0015] (1) Dissolve sodium molybdate, trisodium phosphate and sodium acetate in deionized water. After complete dissolution, add nitric acid to adjust the pH to 7.2±0.1. Then add zinc powder and stir magnetically until the solution turns light blue. Then filter and dry to obtain modified zinc powder.

[0016] (2) Mix acrylic resin powder, ethyl acetate and xylene evenly to obtain acrylic resin varnish;

[0017] (3) Add modified zinc powder, aluminum powder and nanoparticles to acrylic resin varnish and stir to mix. Then add dispersant and defoamer and mix evenly to obtain the zinc-rich coating.

[0018] Further, in step (1), after drying, the modified zinc powder is ground and sieved to obtain uniformly dispersed modified zinc powder.

[0019] The aforementioned application of a zinc-rich coating in the corrosion protection of steel component substrates involves the following steps: After the substrate surface is pretreated by sanding it with metallographic sandpaper to 400 grit and cleaning to remove oil, the zinc-rich coating is directly applied to the substrate surface. After natural ventilation and curing, an anti-corrosion coating is obtained on the substrate surface.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention uses sodium molybdate, trisodium phosphate, and sodium acetate to modify zinc powder. Sodium molybdate activates the surface of the zinc powder filler, improving the adhesion between the zinc-rich coating and the metal substrate. Simultaneously, the molybdenum compounds generated from the reaction of molybdate with zinc powder in the coating enhance the coating's corrosion resistance. Trisodium phosphate has a certain corrosion-inhibiting effect, forming a protective film and slowing down the corrosion rate of the coating. Furthermore, the reaction of trisodium phosphate with zinc powder generates some insoluble phosphorus compounds, further improving the coating's corrosion resistance. Additionally, trisodium phosphate acts as an additive, adjusting the film-forming speed and structure of the coating. Sodium acetate enhances the wettability and fluidity of the coating liquid, allowing for more uniform distribution on the substrate surface, thus improving the coating's stability and durability. Therefore, the synergistic effect of sodium molybdate, trisodium phosphate, and sodium acetate significantly improves the coating's corrosion resistance. Furthermore, this invention, by adjusting the specific gravity of acrylic resin varnish in the coating and comparing the corrosion protection effect of the coating samples, further enhances the comprehensive anti-corrosion performance of the zinc-rich coating under actual working conditions.

[0022] 2. This invention adds nano-ZnO particles to the zinc-rich coating. On one hand, the nano-particles fill the pores of the modified zinc and aluminum powders in the zinc-rich coating, thereby improving the density of the zinc-rich coating and effectively preventing corrosive media from penetrating the substrate. On the other hand, nano-ZnO itself has antibacterial properties, effectively inhibiting the adhesion of microorganisms to the zinc-rich coating, reducing the possibility of corrosion damage caused by marine microorganisms at the source. Simultaneously, the activated zinc particles in the coating release ZnO with strong bactericidal effects. 2+ This can kill attached bacteria, thereby further enhancing the antimicrobial corrosion protection effect of the zinc-rich coating. Therefore, the zinc-rich coating of the present invention is particularly suitable for anti-corrosion engineering of metal substrates in marine environments.

[0023] 3. The zinc-rich coating of this invention does not contain toxic chromate substances, is environmentally friendly, and is prepared at room temperature (25±3℃). After curing in a well-ventilated environment at room temperature, an anti-corrosion coating can be obtained. The preparation cost is low, and the application is relatively simple. Testing showed that this coating can be directly applied to the surface of cleaned and polished test-grade tinplate sheets and AH36 ship hull steel substrates. The resulting zinc-rich coating samples exhibited good basic performance and good corrosion resistance in seawater. Attached Figure Description

[0024] Figure 1- Example 1: SEM images of zinc powder before and after modification.

[0025] Figure 2 - Example 1: EDS diagrams of zinc powder before and after modification.

[0026] Figure 3 -XRD pattern of modified zinc powder in Example 1.

[0027] Figure 4 - Microscopic morphology of the surface and cross-section of the anti-corrosion coating obtained in Example 1 and Comparative Example 1.

[0028] Figure 5 - Adhesion test diagrams of anti-corrosion coatings obtained in Examples 1, 5 and 6.

[0029] Figure 6 - Results of the anti-corrosion coatings obtained in Example 1 and Comparative Example 6 with 1000h resistance to neutral salt spray.

[0030] Figure 7 - SEM images of the anti-corrosion coatings obtained in Example 1 and Comparative Example 1 after 30 days in seawater solution.

[0031] Figure 8 - EIS spectra of the anti-corrosion coatings obtained in Examples 1-5 and Comparative Example 1 after 30 days in seawater solution.

[0032] Figure 9 - Polarization curves of the anti-corrosion coatings obtained in Examples 1-5 and Comparative Example 1 after 30 days in seawater solution. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] 1) Preparation of modified zinc powder

[0036] 32.35g sodium molybdate, 20.85g trisodium phosphate, 13.05g sodium acetate, and 500mL deionized water were mixed and stirred until completely dissolved. Nitric acid was then added dropwise to control the pH of the modified solution at 7.2±0.1. Next, 80.21g of flaky zinc powder (particle size approximately 20–40μm) was weighed and added to the modified solution. Finally, the mixture was stirred at high speed in a magnetic stirrer until complete modification. After 10 minutes, the solution gradually turned light blue. It was then filtered using a vacuum pump, and the filtered solution was dried in an oven at 80℃. The dried modified zinc powder was then ground and sieved through a 100-mesh standard sieve and sealed for later use. The grinding process was primarily to disperse large agglomerates of the modified zinc powder, and sieving was to remove any unagglomerated large particles.

[0037] 2) Preparation of acrylic resin varnish

[0038] 50.14g of acrylic resin powder, 92.55g of ethyl acetate, and 107.55g of xylene solution were poured into a beaker and mixed and stirred until dissolved to obtain acrylic resin varnish.

[0039] 3) Preparation of anti-corrosion coating

[0040] 30.43g of modified zinc powder, 60g of acrylic resin varnish, 5.07g of aluminum powder, 0.3g of Tween 20, 0.2g of BYK-024 defoamer and 4g of nano ZnO were mixed at room temperature and dispersed by high-speed stirring for 10 minutes. The mixture was then filtered and applied to the iron substrate surface using a No. 2 soft wool brush. After curing naturally in a ventilated place for 48 hours, a zinc-rich anti-corrosion coating was obtained.

[0041] Filtering the prepared coating solution is to ensure its purity and remove impurities such as sand particles and foreign matter. In addition, insufficient stirring of the zinc-rich coating of this invention may produce some large agglomerated particles. If these impurities are not filtered out, they will form uneven defects on the coating surface, affecting the product's appearance and overall quality.

[0042] Example 2

[0043] This embodiment is the same as Embodiment 1, except that in step 3), the modified zinc powder is 32.15g, the aluminum powder is 5.35g, and the nano ZnO is 2g.

[0044] Example 3

[0045] This embodiment is the same as Embodiment 1, except that in step 3), the modified zinc powder is 31.29g, the aluminum powder is 5.21g, and the nano ZnO is 3g.

[0046] Example 4

[0047] This embodiment is the same as Embodiment 1, except that in step 3), the modified zinc powder is 29.57g, the aluminum powder is 4.93g, and the nano ZnO is 5g.

[0048] Example 5

[0049] This embodiment is the same as Embodiment 1, except that in step 3), the modified zinc powder is 28.71g, the aluminum powder is 4.79g, and the nano ZnO is 6g.

[0050] Comparative Example 1

[0051] This embodiment is the same as Embodiment 1, except that in step 3), the modified zinc powder is 33.86g, the aluminum powder is 5.64g, and the nano ZnO is 0g.

[0052] Comparative Example 2

[0053] This embodiment is the same as Embodiment 1, except that sodium tungstate is used instead of sodium molybdate in step 1).

[0054] Comparative Example 3

[0055] This embodiment is the same as Embodiment 1, except that sodium dihydrogen phosphate is used instead of trisodium phosphate in step 1).

[0056] Comparative Example 4

[0057] This embodiment is the same as Embodiment 1, except that in step 1), trisodium citrate is used instead of sodium acetate.

[0058] Comparative Example 5

[0059] This embodiment is the same as embodiment 1, except that in step 3), 4g of nano Al2O3 is used instead of 4g of nano ZnO particles (both nano particles have a particle size of 30±10nm).

[0060] Comparative Example 6

[0061] This embodiment is the same as embodiment 3, except that the amount of acrylic resin varnish in step 3) is 50g.

[0062] Comparative Example 7

[0063] This embodiment is the same as embodiment 3, except that the acrylic resin varnish in step 3) is 65g.

[0064] Comparative Example 8

[0065] This embodiment is the same as embodiment 3, except that the acrylic resin varnish in step 3) is 70g.

[0066] 1. The SEM images of zinc powder before and after modification in Example 1 are shown below. Figure 1 (a) Figure 1 As shown in (b), the surface of the unmodified zinc powder is smooth with no obvious adhering substances, while the surface of the modified zinc powder is rougher and has small particles adhering to it. The EDS and XRD patterns of the modified zinc powder in Example 1 are shown below. Figure 2 and Figure 3 As shown, the results indicate that the reaction between zinc powder and the modified liquid produces substances such as Zn3Mo3O3 and Zn4(PO4)2OH2(H2O)3, which are chemically adsorbed onto the surface of the flake zinc powder.

[0067] 2. Microscopic morphology images of the surface and cross-section of the anti-corrosion coatings obtained in Example 1 and Comparative Example 1 are shown below. Figure 4 As shown, where Figure 4 (a) and 4(c) are comparative examples 1. Figure 4 (b) and 4(d) are examples of Example 1, from Figure 4It is evident that the coating surface without added nano-ZnO particles is porous, while the nano-ZnO particles added in Example 1 fill the pores of the coating, making the prepared coating surface and cross-section more dense and compact, thereby more effectively preventing corrosive media from penetrating into the substrate and causing corrosion.

[0068] 3. The coatings prepared in the above embodiments and comparative examples were applied to the surfaces of AH36 hull steel hangers and test-grade tinplate sheets (gradually polished to 400 mesh). After curing, the coatings exhibited a smooth and flat macroscopic morphology without any bubble defects. The zinc-rich coatings prepared in Examples 1-5 and Comparative Examples 1-8 were further tested for their basic properties. Coating adhesion and neutral salt spray resistance were tested on AH36 hull steel hangers, and coating flexibility was tested on test-grade tinplate sheets. The coating adhesion was tested according to GB / T9286-1998 standard, and the integrity of the coating within the grid was assessed by the cross-cut test. The adhesion grade required by this invention is ≤1. The flexibility was tested according to GB / T 1731-2020 standard. The coating sample was pressed tightly onto the rod shaft of the flexibility tester, and the rod shaft diameter was gradually reduced to observe whether cracks and peeling occurred. The requirement of this invention is ≤3mm. The salt spray resistance was tested according to GB / T 1771-2007 standard. The macroscopic morphology of the surface of each group of coating samples subjected to neutral salt spray corrosion was photographed and recorded every 24 hours. The requirement of this invention is that the time for the first red rust spot to appear is ≥1000 hours. The test results are shown in Table 1.

[0069] Table 1. Test results of basic properties of zinc-rich coatings

[0070] Example 1 47 2 0 pass Example 2 51 2 0 pass Example 3 45 2 0 pass Example 4 49 2 0 pass Example 5 42 2 0 pass Comparative Example 1 47 3 1 pass Comparative Example 2 52 2 1 pass Comparative Example 3 49 2 1 pass Comparative Example 4 59 2 1 pass Comparative Example 5 55 3 1 pass Comparative Example 6 47 3 2 Not passed Comparative Example 7 52 2 1 pass Comparative Example 8 51 2 1 pass

[0071] As can be seen from Table 1: (1) The coating prepared by the present invention is suitable for brushing, and the average thickness of the coating obtained is 50±10μm; and the acrylic resin varnish prepared in Examples 1 to 5 of the present invention has a 60% content and nano ZnO added coating with excellent basic properties, with good adhesion, high flexibility and strong salt spray resistance. Comparing Comparative Examples 2 to 4 with Example 1, it can be seen that replacing any component of the modifying liquid to modify zinc powder will lead to a decrease in coating adhesion, indicating that there is a synergistic effect between sodium molybdate, trisodium phosphate and sodium acetate to improve the adhesion between the coating and the metal substrate. At the same time, comparing Comparative Examples 6 to 8 with Example 1, it can be seen that the proportion of acrylic resin varnish in the coating will also affect the adhesion of the coating.

[0072] The coating samples prepared under 13 systems, including Examples 1-5 and Comparative Examples 1-8, all had a thickness of 50±10 μm, which is suitable for brushing. The flexibility test results of the coating samples showed that the diameter of the shaft without cracks in the coating samples of Examples 1-5, Comparative Examples 2-4, and 7-8 was 2 mm, indicating good flexibility. However, the coating samples of Comparative Examples 1, 5, and 6 showed poor flexibility. This indicates that the acrylic resin varnish content in the coating of this invention is 60%, and the addition of nano-ZnO particles improves the flexibility of the zinc-rich coating. However, using nano-Al2O3 particles instead of nano-ZnO reduces the flexibility of the coating.

[0073] The adhesion test results of the present invention at three levels are illustrated using the coating samples of Example 1, Comparative Example 5, and Comparative Example 6 as representative examples. Figure 5 As shown, where Figure 5 (c) is Example 1. Figure 5 (b) is for comparative example 5. Figure 5 (a) is Comparative Example 6. As can be seen from the figure, the scratch of the sample of Example 1 is smooth and there is basically no coating peeling around it, which is rated as level 0 according to the standard; the sample of Comparative Example 5 has a small amount of coating peeling around the scratch, and the peeling area is less than 5%, which is rated as level 1 according to the standard; the sample of Comparative Example 6 has coating peeling around the scratch, and the peeling area is greater than 5% but less than 15%, which is rated as level 2 according to the standard. This shows that the addition of nano ZnO will make the coating bond better to the iron substrate surface and the coating adhesion better.

[0074] The results of the anti-corrosion coatings obtained in Example 1 and Comparative Example 6 after 1000 hours of neutral salt spray resistance are shown in the figure. Figure 6 As shown, where Figure 6 (a) is Comparative Example 6. Figure 6 (b) In Example 1, under accelerated corrosion testing in a salt spray chamber, the zinc-aluminum powder and nano-ZnO in the coating preferentially corroded due to the cathodic protection of the coating. The corrosion products generated by the zinc-aluminum powder moved towards the damaged area of ​​the coating, covering the damaged area of ​​the coating surface, allowing the coating to continue to play a physical shielding role. However, as the corrosion time increased, some areas of the coating surface prepared by Comparative Example 6, which had a lower specific gravity of acrylic resin varnish, lost its physical shielding, cathodic protection, and self-healing effects, causing the substrate to be corroded. The coating of Comparative Example 6 had already formed red rust spots before the 1000h test node. Subsequently, the corrosive medium caused the corrosion area to expand through the corrosion defects on the coating surface, forming a large area of ​​red rust spots at 1000h, leading to the failure of the coating. Therefore, the neutral salt spray test was not passed. In contrast, the zinc-rich coating prepared in Example 1 with a specific gravity of 60% acrylic resin varnish remained smooth and had a certain metallic luster after 1000h of corrosion. The corrosion resistance of the coating was greatly improved, and the neutral salt spray test was passed.

[0075] 4. Using natural seawater rich in bacteria as the corrosion solution, a 30-day immersion corrosion test was conducted on the six groups of modified zinc-rich coating samples (substrate: AH36 ship hull steel) prepared in Examples 1-5 and Comparative Example 1. SEM images of the zinc-rich coating samples obtained in Example 1 and Comparative Example 1 after 30 days in the seawater solution are shown in Figure 7. Figure 7 (a) is Comparative Example 1. Figure 7 (b) As shown in the figure for Example 1, after immersion in seawater for 30 days, the zinc powder layer on the surface of the anti-corrosion coating sample obtained in Comparative Example 1 underwent large-scale activation and dissolution, resulting in obvious corrosion pits. In contrast, the anti-corrosion coating sample obtained in Example 1, after corrosion, showed a smaller activated area of ​​the zinc powder layer and a relatively intact and smooth surface structure. Comparison of the microscopic corrosion morphology of the two samples revealed that the coating with added nano-ZnO exhibited better corrosion resistance in seawater corrosive solutions and provided better protection against corrosive media. The improved corrosion resistance also extended the service life of the coating. This is because nano-ZnO itself possesses antibacterial properties, and its interaction with metal ions forms a protective film on the filler surface, thereby reducing the corrosion of the coating surface by microorganisms in seawater while further enhancing the coating's antioxidant and corrosion-resistant properties. Since nano-ZnO has high surface energy, excessive addition in organic coatings can easily lead to agglomeration, reducing energy and thus losing the characteristics of nanoparticles. Therefore, determining the appropriate nano-ZnO addition ratio for the coating of this invention to achieve optimal protective performance is crucial. To investigate the optimal addition ratio of nano-ZnO in the coating, the corrosion resistance of each group of coating samples was further evaluated using a three-electrode electrochemical testing system. The experimental results are shown in Table 2. The EIS spectra and polarization curves of the anti-corrosion coatings obtained in Examples 1-5 and Comparative Example 1 are shown in Table 2. Figure 8 and Figure 9 As shown.

[0076] Table 2. Electrochemical performance test results of the anti-corrosion coatings obtained in Examples 1-5 and Comparative Example 1

[0077]

[0078] Note: In this work, the threshold value for the open circuit potential (OCP) of the coating cathodic protection is generally selected as the threshold potential of the cathodic protection effect on the steel substrate -0.86V (vs. SCE). When the OCP value is lower than the threshold potential, the cathodic protection effect is "passed"; when the OCP value is higher than the threshold potential, it is "failed". Table 2 shows the electrochemical performance test results of each group of coatings. It can be seen that the open circuit potentials of Examples 1-5 and Comparative Example 1 are all lower than the threshold potential within 30 days, indicating that the cathodic protection effect of the six groups of coating samples is passed. Meanwhile, the low-frequency impedance modulus values ​​of the coating samples prepared under the systems of Examples 1-5 in the seawater environment are all greater than those of Comparative Example 1. Furthermore, the sample of Example 1 has the largest Nyqusit capacitive arc radius, the largest low-frequency impedance modulus, and the smallest corrosion current density obtained from the polarization curve fitting. Further increasing the amount of nano-ZnO added to the coating will lead to a decrease in the anti-corrosion performance of the coating. Electrochemical results indicate that the corrosion protection effect of the 4% nano-ZnO zinc-rich coating in this invention has reached its optimal level. Considering the high cost of the nano-ZnO filler coating, it is more economical and practical to use the zinc-rich coating prepared in Example 1 of this invention for seawater corrosion protection of metal surfaces.

[0079] Finally, it should be noted that the above embodiments of the present invention are merely illustrative examples and not intended to limit the implementation of the invention. Those skilled in the art can make other variations and modifications based on the above description. It is impossible to exhaustively list all possible implementations here. All obvious variations or modifications derived from the technical solutions of this invention are still within the scope of protection of this invention.

Claims

1. A zinc-rich coating, characterized in that, It includes 20-40 parts modified zinc powder, 55-60 parts acrylic resin varnish, 4-6 parts aluminum powder, 2-6 parts nanoparticles; 0.3-0.5 parts dispersant; and 0.2-0.5 parts defoamer. The modified zinc powder is obtained by modifying zinc powder with a modifying solution, which includes sodium molybdate, trisodium phosphate, sodium acetate, and deionized water; wherein the mass-volume ratio of sodium molybdate, trisodium phosphate, sodium acetate, and deionized water in the modifying solution is 5~7g:3~5g:2~4g:100mL; and the mass ratio of zinc powder to sodium molybdate is 2~3:

1. The acrylic resin varnish is composed of acrylic resin powder, ethyl acetate and xylene; the zinc powder and aluminum powder are in the form of flakes with a particle size of 30±10μm; the nanoparticles are nano ZnO with a particle size of 30±10 nm.

2. The zinc-rich coating according to claim 1, characterized in that, The mass ratio of acrylic resin powder, ethyl acetate and xylene is 2~3:3~5:4~6.

3. The zinc-rich coating according to claim 1, characterized in that, The dispersant is Tween 20; the defoamer is an organosilicon defoamer.

4. A method for preparing a zinc-rich coating according to any one of claims 1 to 3, characterized in that, Includes the following steps: (1) Dissolve sodium molybdate, trisodium phosphate and sodium acetate in deionized water. After complete dissolution, add nitric acid to adjust the pH to 7.2±0.

1. Then add zinc powder and stir magnetically until the solution turns light blue. Then filter and dry to obtain modified zinc powder. (2) Mix acrylic resin powder, ethyl acetate and xylene evenly to obtain acrylic resin varnish; (3) Add modified zinc powder, aluminum powder and nanoparticles to acrylic resin varnish and stir to mix. Then add dispersant and defoamer and mix evenly to obtain the zinc-rich coating.

5. The method for preparing a zinc-rich coating according to claim 4, characterized in that, In step (1), after drying, the modified zinc powder is ground and sieved to obtain a uniformly dispersed modified zinc powder.

6. The application of the zinc-rich coating according to any one of claims 1 to 3 in the corrosion protection of steel component substrates.

7. The application of the zinc-rich coating according to claim 6, characterized in that, After the substrate surface is pretreated by sanding with metallographic sandpaper to 400 grit and cleaning to remove oil, zinc-rich coating is directly applied to the substrate surface. After natural ventilation and curing, an anti-corrosion coating is obtained on the substrate surface.

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