Anti-condensation coating based on nano aerogel and preparation method of anti-condensation coating

Abstract

The invention relates to the field of functional coatings, in particular to an anti-condensation coating based on nano aerogel and a preparation method of the anti-condensation coating. The anti-condensation coating based on the nano aerogel at least comprises the following raw materials in parts by mass: 100 to 130 parts of a resin base material, 20 to 35 parts of the nano aerogel, 20 to 35 parts of composite functional particles, 2 to 4 parts of a wetting dispersant, 0.2 to 0.4 part of a defoaming agent, 2 to 5 parts of a coalescing agent and 30 to 60 parts of water. According to the prepared nano aerogel anti-condensation coating, a gradient porous structure is constructed and matched with specific raw materials, a heat bridge is fundamentally blocked, the surface temperature of a base material is remarkably increased, and therefore the condensation phenomenon is efficiently eradicated within the wide temperature and humidity range; and the coating is endowed with extremely high mechanical strength, excellent water resistance and moisture resistance, and excellent durability capable of resisting long-term salt mist and ultraviolet aging.

Description

Technical Field

[0001] This application relates to the field of functional coatings, and more specifically to an anti-condensation coating based on nano-aerogel and its preparation method. Background Technology

[0002] In fields such as construction, warehousing, cold chain transportation, and marine engineering, the phenomenon of water vapor condensing into dew on object surfaces is extremely common when the ambient temperature is below the air dew point temperature. Condensation not only breeds mold, pollutes the environment, and harms health, but also leads to structural corrosion, paint peeling, and even electrical short circuits, seriously affecting the service life and safety of related facilities.

[0003] Traditionally, methods to address condensation problems include enhanced ventilation, the use of insulation materials, and the application of anti-condensation coatings. While enhanced ventilation can reduce air humidity, its effectiveness is limited in enclosed spaces or under specific climatic conditions, and it is also energy-intensive. Using insulation materials such as polystyrene boards and polyurethane foam for wall insulation presents challenges due to complex construction, high costs, and space requirements, making it particularly unsuitable for retrofitting existing buildings. Currently, the most common anti-condensation coatings on the market are porous hygroscopic types, relying on the hygroscopic properties of porous fillers such as diatomaceous earth and perlite to temporarily delay condensation. However, these coatings have inherent drawbacks: their moisture absorption capacity is limited, and once saturated, they lose their anti-condensation ability, becoming a source of moisture and pollution instead; their thermal conductivity is not low enough to effectively block thermal bridges, resulting in a short-lived anti-condensation effect; and the extensive use of porous fillers leads to poor mechanical strength of the paint film, making it prone to powdering and peeling after repeated moisture absorption and desiccation cycles, resulting in insufficient durability.

[0004] In summary, existing anti-condensation solutions generally have their own limitations, such as water absorption failure, limited functionality, excessive thickness and weight, or insufficient durability and environmental adaptability. They are unable to provide long-lasting, stable, and efficient anti-condensation protection under complex and harsh environments such as prolonged high humidity, salt spray, and ultraviolet radiation. Therefore, there is an urgent need in this field to develop a high-efficiency anti-condensation coating that combines low thermal conductivity, low water absorption, high moisture resistance factor, and excellent mechanical strength. Summary of the Invention

[0005] To address the aforementioned issues, this application proposes an anti-condensation coating based on nano-aerogel and its preparation method.

[0006] An anti-condensation coating based on nano-aerogel, comprising, by weight, at least the following raw materials: 100-130 parts resin base, 20-35 parts nano-aerogel, 20-35 parts composite functional particles, 2-4 parts wetting and dispersing agent, 0.2-0.4 parts defoamer, 2-5 parts film-forming aid, and 30-60 parts water.

[0007] Preferably, the resin base is a combination of an aqueous polyurethane-urea dispersion emulsion and an organosilicon-acrylic hybrid emulsion.

[0008] Preferably, the mass ratio of the aqueous polyurethane-urea dispersion emulsion to the organosilicon-acrylic hybrid emulsion is (6~8):(2~4).

[0009] Preferably, the mass ratio of the aqueous polyurethane-urea dispersion emulsion to the organosilicon-acrylic hybrid emulsion is (6.5~7.5):(3~3.5).

[0010] Preferably, the aqueous polyurethane-urea dispersion emulsion is Archsol-835, sourced from Wanhua Chemical.

[0011] Preferably, the nano-aerogel is nano-SiO2 aerogel powder.

[0012] Preferably, the average primary particle size of the nano-SiO2 aerogel powder is 10~20nm.

[0013] Preferably, the average particle size of the aggregates D50 of the nano-SiO2 aerogel powder is 5~10μm.

[0014] Preferably, the specific surface area of ​​the nano-SiO2 aerogel powder is 600~800m² / g, and the porosity is ≥90%.

[0015] Preferably, the nano-SiO2 aerogel powder is AG-DC15, which comes from Jiangsu Hanxin Tiancheng New Materials.

[0016] Preferably, the composite functional particles are a combination of plate-like boron nitride, ATO@TiO2, and diatomaceous earth.

[0017] Preferably, the mass ratio of the sheet-like boron nitride, ATO@TiO2 and diatomaceous earth is (1.5~2.5):(0.2~0.6):(0.5~1).

[0018] Preferably, the mass ratio of the sheet-like boron nitride, ATO@TiO2 and diatomaceous earth is (2~2.5):(0.3~0.5):(0.8~1).

[0019] Preferably, the average D50 particle size of the plate-like boron nitride is 6~10μm.

[0020] Preferably, the fineness of the diatomaceous earth is 1500~2000 mesh.

[0021] Preferably, the average D50 particle size of the ATO@TiO2 is 0.5~1.2μm.

[0022] This application utilizes a composite combination of waterborne polyurethane-urea dispersion emulsion, nano-SiO2 aerogel, and composite functional particles to significantly improve the overall performance of the anti-condensation coating while maintaining excellent low thermal conductivity, low water absorption, moisture resistance, and mechanical strength. The aerogel-functional particle-gradient polymer shell structure significantly reduces the coating's water absorption rate and weakens the rate of change in thermal coefficient after water absorption, ensuring performance stability under long-term high humidity environments. Furthermore, by employing a specific type of aerogel raw material to weaken the hydroxyl effect on its surface, water molecule adsorption is blocked. The elastic polyurethane-urea shell buffers external impacts, ensuring the stability of the internal aerogel-functional particle skeleton and avoiding brittleness and hydrophilic defects. The flake-like boron nitride and ATO@TiO2 work together to shield against heat radiation and conduction. The coating simultaneously possesses moisture and water resistance, heat insulation, and salt spray resistance, ensuring its effectiveness in complex environments such as high salt spray in the ocean, ultraviolet radiation, and large diurnal temperature variations.

[0023] Preferably, the wetting and dispersing agent is at least one selected from polyether siloxane copolymer, ammonium polyacrylate, alkylphenol polyoxyethylene ether, and maleic anhydride copolymer.

[0024] Preferably, the wetting and dispersing agent is a polyether siloxane copolymer or an ammonium polyacrylate.

[0025] Preferably, the wetting and dispersing agent is ammonium polyacrylate.

[0026] Preferably, the defoamer is at least one of silicone defoamers.

[0027] Preferably, the film-forming aid is at least one selected from dodecyl alcohol ester, dipropylene glycol butyl ether, tripropylene glycol butyl ether, and ethylene glycol butyl ether.

[0028] Preferably, the film-forming aid is dodecyl alcohol ester and / or dipropylene glycol butyl ether.

[0029] Preferably, the film-forming aid is a dodecyl alcohol ester.

[0030] Preferably, the mass ratio of the resin base, nano-aerogel and composite functional particles is (10~12):(2.2~3):(2.4~2.8).

[0031] Preferably, the mass ratio of the resin base, nano-aerogel and composite functional particles is (10~11):(2.6~3):(2.5~2.6).

[0032] Preferably, the anti-condensation coating based on nano-aerogel further comprises, by weight, 10-15 parts of auxiliary reinforcing agent, 3-8 parts of thickener, 2-5 parts of surface modifier, and 0.5-1.5 parts of pH adjuster.

[0033] Preferably, the mass ratio of the resin base to the auxiliary reinforcing agent is (10~12):(1~1.3).

[0034] Preferably, the mass ratio of the resin base to the auxiliary reinforcing agent is (10~11):(1.1~1.2).

[0035] Preferably, the auxiliary reinforcing agent is a combination of waterborne polycarbodiimide and fluorinated polyether acrylate oligomer.

[0036] Preferably, the mass ratio of the aqueous polycarbodiimide to the fluorinated polyether acrylate oligomer is (3~6):(1.5~2.5).

[0037] Preferably, the mass ratio of the aqueous polycarbodiimide to the fluorinated polyether acrylate oligomer is (4~5):(1.8~2.2).

[0038] Preferably, the aqueous polycarbodiimide is SV-02, manufactured by Nisshinbo, Japan.

[0039] Preferably, the fluorinated polyether acrylate oligomer is AD1700, manufactured by Solvay, USA.

[0040] The addition of auxiliary reinforcing agents actively interacts with the active functional groups in the resin system through efficient cross-linking, constructing a high-density covalent cross-linked network within the coating. This skeletal structure strengthens the coating's mechanical strength, adhesion, and hydrolysis resistance, making it more resistant to physical damage and penetrating corrosion. Simultaneously, thanks to fluorinated segments, these segments migrate to the coating surface and anchor during curing, forming a dense protective layer that imparts excellent and durable hydrophobic and oleophobic properties and stain resistance. The combined effect of these two factors effectively limits the movement and migration rate of water vapor and solves the coating's brittleness problem. Furthermore, it achieves multiple performance improvements, including salt spray resistance, weather resistance, low water absorption, and enhanced mechanical strength, ensuring the long-term effectiveness and lifespan of the nano-aerogel anti-condensation coating in harsh environments.

[0041] Preferably, the thickener is an associative polyurethane or a cellulose ether.

[0042] Preferably, the thickener is a cellulose ether.

[0043] Preferably, the thickener is any one of hydroxyethyl cellulose, hydroxypropyl methylcellulose, and methylcellulose.

[0044] Preferably, the surface modifier is at least one of fluorosiloxane, polyethylene wax, and organosilicon resin.

[0045] Preferably, the surface modifier is a fluorosiloxane or a polyethylene wax.

[0046] Preferably, the surface modifier is polyethylene wax.

[0047] Preferably, the pH adjuster is any one of ammonia, potassium hydroxide, sodium bicarbonate, and triethanolamine.

[0048] Preferably, the pH adjuster is sodium bicarbonate or triethanolamine.

[0049] A method for preparing the anti-condensation coating based on nano-aerogel includes the following steps: S1: Add all water, wetting and dispersing agent, and defoamer to the main mixing tank, then slowly add composite functional particles, and continuously stir and disperse to obtain a dispersion slurry; S2: Add resin base material to a high-speed mixer, then slowly add nano-aerogel in three equal portions, stirring at 400-500 rpm for 5-10 minutes each time to ensure that all nano-aerogel particles are fully coated, to obtain a premix; S3: Transfer the dispersion slurry to the main mixing vessel, add the remaining raw materials except for the surface modifier, increase the speed after addition and add the premix, continuously stir to ensure uniform dispersion of the system, reduce the speed and add the surface modifier and stir, then defoam, and filter the discharged material through a 200-mesh sieve to obtain the final product.

[0050] Preferably, the preparation method of the anti-condensation coating based on nano-aerogel specifically includes the following steps: S1: 300~400 Add all water, wetting and dispersing agent, and defoamer to the main mixing tank under rpm stirring. Then slowly add the composite functional particles, increase the speed to 600-800 rpm and continue stirring for 20-30 minutes to obtain a dispersion slurry. S2: In a high-speed mixer, add resin base material, stir at 200-300 rpm and slowly add nano-aerogel in three equal portions. Each addition is stirred at 400-500 rpm for 5-10 minutes to ensure that all nano-aerogel particles are fully coated to obtain a premix. S3: Transfer the dispersion slurry to the main mixing vessel, add the remaining raw materials except for the surface modifier at 200-300 rpm. After the addition is complete, increase the speed to 600-700 rpm and add the premix. Continue stirring for 10-15 minutes to ensure that the system is evenly dispersed. Reduce the speed to 200-300 rpm and finally add the surface modifier and stir for 10-15 minutes. Then degas for 5-10 minutes. After discharge, filter through a 200-mesh sieve to obtain the final product.

[0051] The beneficial effects of this application are: 1. The nano-aerogel anti-condensation coating prepared in this application, by constructing a gradient porous structure and using specific raw materials, fundamentally blocks thermal bridges and significantly increases the surface temperature of the substrate, thereby effectively preventing condensation over a wide temperature and humidity range. Simultaneously, a unique synergistic reinforcement system forms a dense cross-linked network and a superhydrophobic protective layer within the coating, endowing it with extremely high mechanical strength, excellent waterproof and moisture resistance, and superior durability against long-term salt spray and UV aging. Ultimately, the ultra-thin coating achieves a long-term, efficient, and stable anti-condensation effect that significantly surpasses traditional thick insulation materials, while also possessing multiple protective functions such as self-cleaning, greatly improving the application quality of the anti-condensation coating.

[0052] 2. This application utilizes a combination of waterborne polyurethane-urea dispersion emulsion, nano-SiO2 aerogel, and composite functional particles to significantly improve the overall performance of the anti-condensation coating while maintaining excellent low thermal conductivity, low water absorption, moisture resistance, and mechanical strength. By employing a specific type of aerogel raw material, the hydroxyl groups on its surface are weakened, thereby blocking the adsorption of water molecules. The elastic polyurethane-urea shell buffers external impacts, ensuring the stability of the internal aerogel-functional particle skeleton and avoiding brittleness and hydrophilic defects. Furthermore, the flake-like boron nitride and ATO@TiO2 work together to shield against heat radiation and conduction. The coating simultaneously possesses moisture and water resistance, heat insulation, and salt spray resistance, ensuring its application performance in complex environments such as high salt spray in the ocean, ultraviolet radiation, and large diurnal temperature variations.

[0053] 3. This application further incorporates an auxiliary reinforcing agent to actively interact with the active functional groups in the resin system through efficient cross-linking, constructing a high-density covalent cross-linked network within the coating. This framework strengthens the coating's mechanical strength, adhesion, and hydrolysis resistance, making it more resistant to physical damage and penetrating corrosion. The combined effect of the two raw materials effectively limits the movement and migration rate of water vapor and solves the coating brittleness problem. Furthermore, it achieves multiple performance improvements, including salt spray resistance, weather resistance, low water absorption, and enhanced mechanical strength, ensuring the long-term effectiveness and lifespan of the nano-aerogel anti-condensation coating under harsh environments. Attached Figure Description

[0054] Figure 1 This is a comparison diagram of the anti-condensation coating based on nano-aerogel prepared in Example 1 and the existing anti-condensation coating of acrylic polyurethane topcoat. The left side is the coating of Example 1, and the right side is the acrylic polyurethane topcoat.

[0055] Figure 2 This is a comparison chart showing the anti-condensation effect of the nano-aerogel anti-condensation coating prepared in Example 1 of this application.

[0056] In the figure: 1 - uncoated surface, 2 - coated surface. Detailed Implementation Example 1

[0057] An anti-condensation coating based on nano-aerogel comprises, by weight, the following raw materials: 100 parts resin base, 28 parts nano-aerogel, 25.5 parts composite functional particles, 3.4 parts wetting and dispersing agent, 0.3 parts defoamer, 2.6 parts film-forming aid, 38.5 parts water, 11 parts auxiliary reinforcing agent, 4.5 parts thickener, 3.2 parts surface modifier, and 0.8 parts pH adjuster.

[0058] The resin base is a combination of waterborne polyurethane-urea dispersion emulsion and organosilicon-acrylic hybrid emulsion in a mass ratio of 7:3. The waterborne polyurethane-urea dispersion emulsion is Archsol-8355, manufactured by Wanhua Chemical. The organosilicon-acrylic hybrid emulsion is HBC-3000, manufactured by Shenzhen Cansen Chemical.

[0059] The nano-aerogel is a nano-SiO2 aerogel powder with an average primary particle size of 15nm, an average aggregate D50 particle size of 7.5μm, a specific surface area of ​​680m² / g, and a porosity of 92%; the nano-SiO2 aerogel powder AG-DC15 is from Jiangsu Hanxin Tiancheng New Materials.

[0060] The composite functional particles are a combination of plate-like boron nitride, ATO@TiO2, and diatomaceous earth in a mass ratio of 2.2:0.5:0.8. The plate-like boron nitride has an average D50 particle size of 6.5 μm; the diatomaceous earth has a fineness of 1750 mesh; and the ATO@TiO2 has an average D50 particle size of 0.8 μm, is rutile, and is manufactured by Longbai Group.

[0061] The wetting and dispersing agent is ammonium polyacrylate, namely Sanopco 5040; the defoamer is silicone defoamer BYK-024; the film-forming aid is dodecyl alcohol ester; the thickener is hydroxyethyl cellulose; the surface modifier is polyethylene wax DeuRheo 201P, Haimingsi; and the pH adjuster is sodium bicarbonate.

[0062] The auxiliary reinforcing agent is a combination of waterborne polycarbodiimide and fluorinated polyether acrylate oligomers in a mass ratio of 4.5:2. Specifically, the waterborne polycarbodiimide is SV-02, manufactured by Nisshinbo, Japan; the fluorinated polyether acrylate oligomer is AD1700, manufactured by Solvay, USA.

[0063] A method for preparing an anti-condensation coating based on nano-aerogel includes the following steps: S1: Add all water, wetting and dispersing agent, and defoamer to the main mixing tank under stirring at 400 rpm, then slowly add composite functional particles, increase the speed to 800 rpm and continue stirring and dispersing for 25 min, to obtain a dispersion slurry; S2: In a high-speed mixer, add resin base material, stir at 250 rpm and slowly add nano-aerogel in three equal portions, stirring at 450 rpm for 8 min each time to ensure that all nano-aerogel particles are fully coated, to obtain a premix; S3: Transfer the dispersion slurry to the main mixing vessel, add the remaining raw materials except for the surface modifier at 240 rpm, increase the speed to 600 rpm and add the premix, continue stirring for 12 min to ensure uniform dispersion of the system, reduce the speed to 250 rpm, finally add the surface modifier and stir for 12 min, then defoam for 8 min, and filter through a 200-mesh sieve after discharge to obtain the final product.

[0064] The physical sample of the anti-condensation coating based on nano-aerogel prepared in this embodiment is shown below. Figure 1 As shown. Example 2

[0065] This embodiment differs from Embodiment 1 only in the following aspects: An anti-condensation coating based on nano-aerogel, by weight, comprises the following raw materials: 110 parts resin base, 24 parts nano-aerogel, 28 parts composite functional particles, 3.4 parts wetting and dispersing agent, 0.3 parts defoamer, 2.6 parts film-forming aid, 38.5 parts water, 12.5 parts auxiliary reinforcing agent, 4.5 parts thickener, 3.2 parts surface modifier, and 0.8 parts pH adjuster.

[0066] The remaining implementation methods are the same. Example 3

[0067] This embodiment differs from Embodiment 1 only in the following aspects: An anti-condensation coating based on nano-aerogel, by weight, comprises the following raw materials: 120 parts resin base, 25 parts nano-aerogel, 24.5 parts composite functional particles, 3.4 parts wetting and dispersing agent, 0.3 parts defoamer, 2.6 parts film-forming aid, 38.5 parts water, 10 parts auxiliary reinforcing agent, 4.5 parts thickener, 3.2 parts surface modifier, and 0.8 parts pH adjuster.

[0068] The remaining implementation methods are the same.

[0069] Comparative Example 1 This comparative example differs from Example 1 only in the following aspects: an anti-condensation coating based on nano-aerogel, comprising, by weight, the following raw materials: 120 parts resin base, 28 parts nano-aerogel, 25.5 parts composite functional particles, 3.4 parts wetting and dispersing agent, 0.3 parts defoamer, 2.6 parts film-forming aid, 38.5 parts water, 3.5 parts auxiliary reinforcing agent, 4.5 parts thickener, 3.2 parts surface modifier, and 0.8 parts pH adjuster.

[0070] The remaining implementation methods are the same.

[0071] Comparative Example 2 This comparative example differs from Example 1 only in the following aspects: an anti-condensation coating based on nano-aerogel, comprising, by weight, the following raw materials: 110 parts resin base, 20 parts nano-aerogel, 18.5 parts composite functional particles, 3.4 parts wetting and dispersing agent, 0.3 parts defoamer, 2.6 parts film-forming aid, 38.5 parts water, 11 parts auxiliary reinforcing agent, 4.5 parts thickener, 3.2 parts surface modifier, and 0.8 parts pH adjuster.

[0072] The remaining implementation methods are the same.

[0073] Comparative Example 3 The only difference between this comparative example and Example 1 is that the resin base is a combination of waterborne polyurethane-urea dispersion emulsion and organosilicon-acrylic hybrid emulsion in a mass ratio of 1:1.

[0074] The remaining implementation methods are the same.

[0075] Comparative Example 4 The only difference between this comparative example and Example 1 is that the resin base is a combination of waterborne polyurethane-urea dispersion emulsion and organosilicon-acrylic hybrid emulsion in a mass ratio of 9:1.

[0076] The remaining implementation methods are the same.

[0077] Comparative Example 5 The only difference between this comparative example and Example 1 is that the composite functional particles are a combination of sheet-like boron nitride, ATO@TiO2 and diatomaceous earth, with a mass ratio of 4:0.1:0.3.

[0078] The remaining implementation methods are the same.

[0079] Comparative Example 6 The only difference between this comparative example and Example 1 is that the auxiliary reinforcing agent is a combination of waterborne polycarbodiimide and fluorinated polyether acrylate oligomers in a mass ratio of 6:0.5.

[0080] The remaining implementation methods are the same.

[0081] Comparative Example 7 The only difference between this comparative example and Example 1 is that the auxiliary reinforcing agent is a combination of waterborne polycarbodiimide and fluorinated polyether acrylate oligomers in a mass ratio of 1:3.

[0082] The remaining implementation methods are the same.

[0083] Performance testing 1. Thermal conductivity: The test was conducted in accordance with GB / T 10297, and the average of 10 tests was recorded in Table 1.

[0084] 2. Anti-condensation effect: The coating was applied to one side of a stainless steel cup to a depth of 150 μm, while the other side remained uncoated as a control. An ice-water mixture (0~5℃) was poured into the stainless steel cup. The test environment was set at a temperature of 15±2℃ and a relative humidity of 85±3%. After maintaining this temperature for 4 days, the appearance of condensation droplets on the coating surface was observed. No condensation (condensation area 0% of the total coated area), slight condensation (0% ≤ condensation area ≤ 15% of the total coated area), and significant condensation (condensation area > 15% of the total coated area) were recorded. The results are shown in Table 1. Comparison of the test effects of the anti-condensation coating prepared in Example 1. Figure 2 As shown, (1) is the uncoated surface and (2) is the coated surface; obvious condensation was observed on the uncoated surface, while no condensation was observed on the side of the stainless steel cup coated with the coating of Example 1.

[0085] 3. Water absorption rate: The test was conducted in accordance with GB / T 1738-2020, and the results were the average of 10 tests and recorded in Table 1.

[0086] 4. Salt spray resistance: The test is conducted according to GB / T 1771-2007. After 3000 hours of testing, the surface is scratched to detect blistering, rusting, and peeling. If any of these occur, the test is considered unqualified; otherwise, it is considered qualified. Each group is tested 50 times, and the pass rate of each group is recorded in Table 1.

[0087] 5. Scrub resistance: The test is conducted in accordance with GB / T 9266-2009. The coating is evenly applied to a standard asbestos cement board. A scrub resistance tester is used with a 1kg brush loaded. The coating surface is scrubbed repeatedly in a cyclical manner. The number of scrubs before the coating is first worn through and the substrate is exposed is recorded. The number of scrubs is counted every 500 times and recorded in Table 1.

[0088] Table 1 Performance Test Results

[0089] Examples 1-3 achieved superior performance test results compared to Comparative Examples 1-7. The combined effect of the limited waterborne polyurethane-urea dispersion emulsion, nano-SiO2 aerogel, and composite functional particles used in Examples 1-3, along with the auxiliary reinforcing agent, significantly improved the internal stability of the coating, avoiding brittleness and hydrophilic defects. It also shielded against heat radiation and conduction, ensuring excellent thermal insulation performance while enhancing the coating's mechanical strength, adhesion, and hydrolysis resistance. Furthermore, the auxiliary reinforcing agent better resists physical damage and penetrating corrosion. The combined effect of the two raw materials effectively limited the movement and migration rate of water vapor and solved the coating brittleness problem. Based on this, multiple performance improvements were achieved, including salt spray resistance, weather resistance, low water absorption, and mechanical strength. This ensured the long-term effectiveness and lifespan of the nano-aerogel anti-condensation coating in harsh environments, guaranteeing its application performance in complex environments such as high salt spray in the ocean, ultraviolet radiation, and large diurnal temperature variations. In contrast, Comparative Examples 1 to 7 employed different non-limited technical solutions, resulting in a significant reduction in the effectiveness of their respective raw materials within the coating system, thus leading to a substantial decrease in their overall performance.

Claims

1. A nano-aerogel based anti-fogging coating characterized in that: The raw materials include at least: 100-130 parts of resin base, 20-35 parts of nano-aerogel, 20-35 parts of composite functional particles, 2-4 parts of wetting dispersant, 0.2-0.4 parts of defoaming agent, 2-5 parts of film-forming aid, 30-60 parts of water, in terms of mass fraction; The resin base is a combination of water-based polyurethane-urea dispersion emulsion and silicone-acrylic hybrid emulsion, with a mass ratio of (6-8):(2-4); The nano-aerogel is nano-SiO2 aerogel powder, with an average primary particle size of 10-20 nm, a specific surface area of 600-800 m² / g, and a porosity of ≥90%.

2. The nano-aerogel based anti-fogging coating according to claim 1, characterized in that: The composite functional particles are a combination of flaky boron nitride, ATO@TiO2 and diatomite, with a mass ratio of (1.5-2.5):(0.2-0.6):(0.5-1).

3. The nano-aerogel based anti-fogging coating according to claim 2, characterized in that: The flaky boron nitride has a D50 average particle size of 6-10 μm; and the diatomite has a fineness of 1500-2000 mesh.

4. The nano-aerogel based anti-fogging coating according to claim 3, characterized in that: The wetting dispersant is at least one of polyether siloxane copolymer, polyacrylic acid ammonium salt, alkyl phenol polyoxyethylene ether and maleic anhydride copolymer.

5. The nano-aerogel based anti-fogging coating according to claim 4, characterized in that: The film-forming aid is at least one of dodecanol ester, dipropylene glycol butyl ether, tripropylene glycol butyl ether and ethylene glycol butyl ether.

6. The nano-aerogel based anti-fogging coating according to claim 5, characterized in that: The mass ratio of the resin base, nano-aerogel and composite functional particles is (10-12):(2.2-3):(2.4-2.8).

7. The nano-aerogel based anti-fogging coating of claim 1, wherein: The anti-dew coating based on nano-aerogel further includes, in terms of mass fraction: 10-15 parts of auxiliary reinforcing agent, 3-8 parts of thickening agent, 2-5 parts of surface modifier, 0.5-1.5 parts of pH adjuster.

8. The nano-aerogel based anti-fogging coating according to claim 7, characterized in that: The mass ratio of the resin base and auxiliary reinforcing agent is (10-12):(1-1.3).

9. The nano-aerogel based anti-fogging coating according to claim 8, characterized in that: The auxiliary reinforcing agent is a combination of water-based polycarbodiimide and fluorinated polyether acrylate oligomer, with a mass ratio of (3-6):(1.5-2.5).

10. A method of preparing an anti-fogging coating based on nan-aerogel according to any one of claims 7 to 9, characterized in that: S1: Add all the water, wetting dispersant and defoaming agent into the main ingredient tank, then slowly add the composite functional particles, continuously stir and disperse to obtain a dispersion slurry; S2: In a high-speed mixer, add the resin base, then slowly add the nano-aerogel in three equal portions, each time stirring at 400-500 rpm for 5-10 min to ensure that all the nano-aerogel particles are fully wrapped, to obtain a premix; S3: Transfer the dispersion slurry into the main mixing kettle, add the remaining raw materials except the surface modifier, then increase the speed and add the premix, continuously stir to ensure uniform dispersion of the system, then add the surface modifier after reducing the speed, stir, then defoam, filter through a 200 mesh screen after discharging, and the process is completed.

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