Aerogel reflective coating and method of making same

Abstract

This invention relates to the field of coating technology, and proposes an aerogel reflective coating and its preparation method. The aerogel reflective coating comprises the following raw materials in parts by weight: 60-80 parts acrylic emulsion, 10-20 parts silica nano-aerogel, 15-20 parts hollow glass microspheres, 10-20 parts filler, 2-4 parts dispersant, 1-2 parts defoamer, 2-3 parts film-forming aid, 2-3 parts leveling agent, and 30-40 parts water; the filler includes titanium dioxide composite material, boron nitride, and kaolin; the titanium dioxide composite material is obtained by aluminum doping of titanium dioxide followed by bismuth tungstate composite. This technical solution solves the problem of insufficient reflectivity in related technologies for aerogel reflective coatings.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to an aerogel reflective coating and its preparation method. Background Technology

[0002] Aerogel reflective coatings have become a research hotspot in the field of functional coating materials due to their high-efficiency thermal insulation and convenient application. In the construction industry, applying them to exterior walls or roofs can significantly reduce air conditioning energy consumption in summer. In the industrial sector, they can be used on the exterior walls of petrochemical storage tanks, pipelines, and equipment to effectively reduce medium temperature and improve operational safety. In the aerospace and special equipment fields, these coatings can also serve as lightweight thermal protection layers to meet thermal control requirements in extreme environments. However, current market products mostly focus on the thermal insulation function of aerogels, often lacking in reflective properties, making it difficult to achieve efficient light and heat blocking. Therefore, developing an aerogel coating with excellent reflective properties is of great significance. Summary of the Invention

[0003] This invention proposes an aerogel reflective coating and its preparation method, which solves the problem of insufficient reflectivity of aerogel reflective coatings in related technologies.

[0004] The technical solution of the present invention is as follows: This invention proposes an aerogel reflective coating, comprising the following raw materials in parts by weight: 60-80 parts acrylic emulsion, 10-20 parts silica nano-aerogel, 15-20 parts hollow glass microspheres, 10-20 parts filler, 2-4 parts dispersant, 1-2 parts defoamer, 2-3 parts film-forming aid, 2-3 parts leveling agent, and 30-40 parts water; The filler includes titanium dioxide composite material, boron nitride, and kaolin. The titanium dioxide composite material is obtained by doping titanium dioxide with aluminum and then combining it with bismuth tungstate.

[0005] As a further technical solution, the mass ratio of the titanium dioxide composite material, boron nitride, and kaolin is 10:5:8~12.

[0006] As a further technical solution, the preparation method of the titanium dioxide composite material includes the following steps: A1. After aluminum nitrate is added to solvent I and dispersed evenly, ethanolamine and tetrabutyl titanate are added and mixed. After drying, crushing and calcining, aluminum-doped titanium dioxide is obtained. A2. After dispersing sodium tungstate dihydrate in solvent II evenly, premixed solution I is obtained; A3. After dispersing bismuth nitrate pentahydrate evenly in solvent III, add hexadecyltrimethylammonium bromide and aluminum-doped titanium dioxide and mix to obtain premixed solution II; A4. After mixing the premixed liquid I with the premixed liquid II, the mixture is washed and dried to obtain the titanium dioxide composite material.

[0007] As a further technical solution, the mass ratio of tetrabutyl titanate, ethanolamine and aluminum nitrate is 60:62:8~10.

[0008] As a further technical solution, the mass ratio of sodium tungstate dihydrate, bismuth nitrate pentahydrate and tetrabutyl titanate is 20:60:80~100.

[0009] As a further technical solution, in step A1, the mixing time is 1.5~2.5h.

[0010] As a further technical solution, in step A1, the calcination temperature is 550~600℃, and the calcination time is 1.5~2.5h.

[0011] As a further technical solution, in step A4, the mixing temperature is 160~180℃, and the mixing time is 2~3h.

[0012] As a further technical solution, the raw materials of the aerogel reflective coating, by weight, also include 10-15 parts of silicone-modified acrylic emulsion and 5-10 parts of water-based aliphatic polyurethane emulsion.

[0013] In this invention, the reflectivity of the aerogel reflective coating is improved by adding silicone-modified acrylic emulsion and waterborne aliphatic polyurethane emulsion, which synergize with the acrylic emulsion. The acrylic emulsion, as the base film-forming component of the coating, possesses excellent film-forming properties and adhesion. The silicone-modified acrylic emulsion, with its silicone segments in its molecular chain, reduces the surface tension of the coating film, forming a dense and smooth film on the coating surface, reducing surface roughness, and thus reducing diffuse reflection loss of light. Simultaneously, it enhances the coating's reflectivity to ultraviolet and visible light, further improving reflectivity. The waterborne aliphatic polyurethane emulsion exhibits excellent compatibility and flexibility, effectively preventing the decline in reflectivity caused by component separation. The synergistic effect of these three components gives the coating excellent reflectivity in both the visible and near-infrared regions.

[0014] As a further technical solution, the dispersant includes polyphosphate dispersants.

[0015] As a further technical solution, the defoamer includes polyether-modified silicone defoamers.

[0016] As a further technical solution, the film-forming aid includes dodecyl alcohol ester.

[0017] As a further technical solution, the leveling agent includes a polyether-modified silicone leveling agent.

[0018] This invention also proposes a method for preparing an aerogel reflective coating, comprising the following steps: Water and dispersant are mixed, silica aerogel is added and dispersed, acrylic emulsion, hollow glass microspheres, filler, defoamer, leveling agent and film-forming aid are added in sequence, and stirred to obtain aerogel reflective coating.

[0019] The working principle and beneficial effects of this invention are as follows: This invention improves the reflectivity of aerogel reflective coatings by adding titanium dioxide composite material, boron nitride, and kaolin as fillers. The titanium dioxide composite material is obtained by aluminum doping of titanium dioxide followed by bismuth tungstate composite. Aluminum doping optimizes the crystal structure of the titanium dioxide composite, effectively enhancing its reflectivity for visible and near-infrared light. The aluminum-doped titanium dioxide is then combined with bismuth tungstate, which possesses excellent light reflection properties and synergistically enhances the reflection of light across different wavelengths. Boron nitride exhibits good thermal stability and optical inertness; its plate-like structure increases the reflection path of light within the coating, reducing light penetration and thus improving overall reflectivity. Kaolin possesses good dispersibility and hiding power, allowing it to be uniformly dispersed in the coating system, filling gaps within the coating and reducing light scattering loss. Furthermore, it works synergistically with the titanium dioxide composite and boron nitride to enhance the reflectivity of the aerogel reflective coating. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] In the following examples and comparative examples: Acrylic emulsion, model: E0511-X, solid content 45wt%; silicone-modified acrylic emulsion, model: Gemini5860, solid content 40wt%; waterborne aliphatic polyurethane emulsion, model: A-539, solid content 55wt%; silica nano-aerogel, model: MT1200; hollow glass microspheres, average particle size 30μm; polyphosphate dispersant, model: BG1900; polyether-modified silicone defoamer, model: TEGO FOAMEX 1488; polyether-modified silicone leveling agent, model: JY-33; titanium dioxide, average particle size: 0.3μm; boron nitride, average particle size: 2μm; kaolin, average particle size: 3μm.

[0022] Example 1 An aerogel reflective coating comprises the following raw materials in parts by weight: 60 parts acrylic emulsion, 10 parts silica nano-aerogel, 15 parts hollow glass microspheres, 10 parts filler, 2 parts polyphosphate dispersant, 1 part polyether-modified silicone defoamer, 2 parts dodecyl alcohol ester, 2 parts polyether-modified silicone leveling agent, and 30 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of titanium dioxide composite material includes the following steps: A1. Aluminum nitrate was added to glacial acetic acid (the mass-volume ratio of aluminum nitrate to glacial acetic acid was 1 g: 10 mL) and dispersed evenly. Then, ethanolamine and tetrabutyl titanate were added and mixed for 1.5 h. After drying and crushing to 30 μm, aluminum-doped titanium dioxide was obtained by calcining at 550 °C for 2.5 h. The mass ratio of tetrabutyl titanate, ethanolamine and aluminum nitrate was 60:62:8. A2. After dispersing the sodium tungstate dihydrate in water (the mass-volume ratio of sodium tungstate dihydrate to water is 1g:10mL) evenly, premixed solution I is obtained. A3. Bismuth nitrate pentahydrate was added to solvent III (the mass-volume ratio of bismuth nitrate pentahydrate to solvent III was 1 g: 15 mL) and dispersed evenly. Then, hexadecyltrimethylammonium bromide and aluminum-doped titanium dioxide were added and mixed for 1 h to obtain premixed solution II. The mass ratio of sodium tungstate dihydrate, bismuth nitrate pentahydrate and tetrabutyl titanate was 20:60:80. Solvent III was composed of anhydrous ethanol, acetic acid and water in a mass ratio of 1:1:3. Hexadecyltrimethylammonium bromide was 20% of the mass of bismuth nitrate pentahydrate. A4. Add premix I to premix II, place it in a polytetrafluoroethylene-lined hydrothermal reactor, mix at 160°C for 3 hours, and then wash and dry to obtain titanium dioxide composite material. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 8 min, silica aerogel was added and dispersed at 1200 r / min for 40 min, acrylic emulsion, hollow glass microspheres, filler, polyether modified silicone defoamer, polyether modified silicone leveling agent and dodecyl alcohol ester were added in sequence, and stirred at 350 r / min for 2 h to obtain aerogel reflective coating.

[0023] Example 2 An aerogel reflective coating comprises the following raw materials in parts by weight: 70 parts acrylic emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of titanium dioxide composite material includes the following steps: A1. Aluminum nitrate was added to glacial acetic acid (the mass-volume ratio of aluminum nitrate to glacial acetic acid was 1g:10mL) and dispersed evenly. Ethanolamine and tetrabutyl titanate were added and mixed for 2 hours. After drying and crushing to 30μm, aluminum-doped titanium dioxide was obtained by calcining at 580℃ for 2 hours. The mass ratio of tetrabutyl titanate, ethanolamine and aluminum nitrate was 60:62:9. A2. After dispersing the sodium tungstate dihydrate in water (the mass-volume ratio of sodium tungstate dihydrate to water is 1g:10mL) evenly, premixed solution I is obtained. A3. Bismuth nitrate pentahydrate was added to solvent III (the mass-volume ratio of bismuth nitrate pentahydrate to solvent III was 1 g: 15 mL) and dispersed evenly. Then, hexadecyltrimethylammonium bromide and aluminum-doped titanium dioxide were added and mixed for 1.5 h to obtain premixed solution II. The mass ratio of sodium tungstate dihydrate, bismuth nitrate pentahydrate and tetrabutyl titanate was 20:60:90. Solvent III was composed of anhydrous ethanol, acetic acid and water in a mass ratio of 1:1:3. Hexadecyltrimethylammonium bromide was 20% of the mass of bismuth nitrate pentahydrate. A4. Add premix I to premix II, place it in a polytetrafluoroethylene-lined hydrothermal reactor, mix at 170°C for 2.5 h, and then wash and dry to obtain titanium dioxide composite material. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 9 min, silica aerogel was added and dispersed at 1300 r / min for 35 min, then acrylic emulsion, hollow glass microspheres, filler, polyether modified silicone defoamer, polyether modified silicone leveling agent and dodecyl alcohol ester were added in sequence, and stirred at 400 r / min for 1.5 h to obtain aerogel reflective coating.

[0024] Example 3 An aerogel reflective coating comprises the following raw materials in parts by weight: 80 parts acrylic emulsion, 20 parts silica nano-aerogel, 20 parts hollow glass microspheres, 20 parts filler, 4 parts polyphosphate dispersant, 2 parts polyether-modified silicone defoamer, 3 parts dodecyl alcohol ester, 3 parts polyether-modified silicone leveling agent, and 40 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of titanium dioxide composite material includes the following steps: A1. Aluminum nitrate was added to glacial acetic acid (the mass-volume ratio of aluminum nitrate to glacial acetic acid was 1 g: 10 mL) and dispersed evenly. Then, ethanolamine and tetrabutyl titanate were added and mixed for 2.5 h. After drying and crushing to 30 μm, aluminum-doped titanium dioxide was obtained by calcining at 600 °C for 1.5 h. The mass ratio of tetrabutyl titanate, ethanolamine and aluminum nitrate was 60:62:8. A2. After dispersing the sodium tungstate dihydrate in water (the mass-volume ratio of sodium tungstate dihydrate to water is 1g:10mL) evenly, premixed solution I is obtained. A3. Bismuth nitrate pentahydrate was added to solvent III (the mass-volume ratio of bismuth nitrate pentahydrate to solvent III was 1 g: 15 mL) and dispersed evenly. Then, hexadecyltrimethylammonium bromide and aluminum-doped titanium dioxide were added and mixed for 2 h to obtain premixed solution II. The mass ratio of sodium tungstate dihydrate, bismuth nitrate pentahydrate and tetrabutyl titanate was 20:60:100. Solvent III was composed of anhydrous ethanol, acetic acid and water in a mass ratio of 1:1:3. Hexadecyltrimethylammonium bromide was 20% of the mass of bismuth nitrate pentahydrate. A4. Add premix I to premix II, place in a polytetrafluoroethylene-lined hydrothermal reactor, mix at 180°C for 2 hours, and then wash and dry to obtain titanium dioxide composite material. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, acrylic emulsion, hollow glass microspheres, filler, polyether modified silicone defoamer, polyether modified silicone leveling agent and dodecyl alcohol ester were added in sequence, and stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0025] Example 4 The only difference between this embodiment and Embodiment 2 is that the filler in this embodiment is composed of titanium dioxide composite material, boron nitride and kaolin in a mass ratio of 10:5:10.

[0026] Example 5 The only difference between this embodiment and Embodiment 2 is that the filler in this embodiment is composed of titanium dioxide composite material, boron nitride and kaolin in a mass ratio of 10:5:12.

[0027] Example 6 The difference between this embodiment and Embodiment 2 is only that the aerogel reflective coating in this embodiment includes the following raw materials in parts by weight: 70 parts acrylic emulsion, 10 parts silicone-modified acrylic emulsion, 5 parts waterborne aliphatic polyurethane emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of the titanium dioxide composite material is the same as in Embodiment 2. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, and then acrylic emulsion, silicone-modified acrylic emulsion, waterborne aliphatic polyurethane emulsion, hollow glass microspheres, filler, polyether-modified silicone defoamer, polyether-modified silicone leveling agent, and dodecyl alcohol ester were added in sequence. The mixture was stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0028] Example 7 The difference between this embodiment and Embodiment 2 is only that the aerogel reflective coating in this embodiment includes the following raw materials in parts by weight: 70 parts acrylic emulsion, 12 parts silicone-modified acrylic emulsion, 8 parts waterborne aliphatic polyurethane emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of the titanium dioxide composite material is the same as in Embodiment 2. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, and then acrylic emulsion, silicone-modified acrylic emulsion, waterborne aliphatic polyurethane emulsion, hollow glass microspheres, filler, polyether-modified silicone defoamer, polyether-modified silicone leveling agent, and dodecyl alcohol ester were added in sequence. The mixture was stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0029] Example 8 The difference between this embodiment and Embodiment 2 is only that the aerogel reflective coating in this embodiment includes the following raw materials in parts by weight: 70 parts acrylic emulsion, 15 parts silicone-modified acrylic emulsion, 10 parts waterborne aliphatic polyurethane emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of the titanium dioxide composite material is the same as in Embodiment 2. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, and then acrylic emulsion, silicone-modified acrylic emulsion, waterborne aliphatic polyurethane emulsion, hollow glass microspheres, filler, polyether-modified silicone defoamer, polyether-modified silicone leveling agent, and dodecyl alcohol ester were added in sequence. The mixture was stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0030] Example 9 The difference between this embodiment and Embodiment 2 is only that the aerogel reflective coating in this embodiment includes the following raw materials in parts by weight: 70 parts acrylic emulsion, 12 parts silicone-modified acrylic emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of the titanium dioxide composite material is the same as in Embodiment 2. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, acrylic emulsion, silicone-modified acrylic emulsion, hollow glass microspheres, filler, polyether-modified silicone defoamer, polyether-modified silicone leveling agent, and dodecyl alcohol ester were added in sequence, and stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0031] Example 10 The difference between this embodiment and Embodiment 2 is only that the aerogel reflective coating in this embodiment includes the following raw materials in parts by weight: 70 parts acrylic emulsion, 8 parts waterborne aliphatic polyurethane emulsion, 15 parts silica nano-aerogel, 18 parts hollow glass microspheres, 15 parts filler, 3 parts polyphosphate dispersant, 1.5 parts polyether-modified silicone defoamer, 2.5 parts dodecyl alcohol ester, 2.5 parts polyether-modified silicone leveling agent, and 35 parts water. The filler is composed of titanium dioxide composite material, boron nitride, and kaolin in a mass ratio of 10:5:8. The preparation method of the titanium dioxide composite material is the same as in Embodiment 2. A method for preparing an aerogel reflective coating includes the following steps: Water and polyphosphate dispersant were mixed for 10 min, silica aerogel was added and dispersed at 1500 r / min for 30 min, then acrylic emulsion, waterborne aliphatic polyurethane emulsion, hollow glass microspheres, filler, polyether modified silicone defoamer, polyether modified silicone leveling agent and dodecyl alcohol ester were added in sequence, and stirred at 450 r / min for 1 h to obtain aerogel reflective coating.

[0032] Comparative Example 1 The only difference between this comparative example and Example 2 is that the filler in this comparative example is composed of titanium dioxide composite material and boron nitride in a mass ratio of 10:5.

[0033] Comparative Example 2 The only difference between this comparative example and Example 2 is that the filler in this comparative example is composed of titanium dioxide composite material and kaolin in a mass ratio of 10:8.

[0034] Comparative Example 3 The only difference between this comparative example and Example 2 is that the filler in this comparative example is composed of boron nitride and kaolin in a mass ratio of 5:8.

[0035] Test case The aerogel reflective coatings prepared in Examples 1-10 and Comparative Examples 1-3 were tested according to the following method: 1. Reflectivity: In accordance with GB / T 25261 The solar reflectance and near-infrared reflectance were tested using the methods specified in the 2018 standard "Reflective Thermal Insulation Coatings for Buildings". The test results are shown in Table 1.

[0036] Table 1 Performance test results of aerogel reflective coatings prepared in Examples 1-10 and Comparative Examples 1-3

[0037] The solar reflectance and near-infrared reflectance of Examples 1-5 are higher than those of Comparative Examples 1-3, indicating that the present invention improves the reflectivity of aerogel coatings by adding titanium dioxide composite material, boron nitride and kaolin composite as fillers.

[0038] The solar reflectance and near-infrared reflectance of Examples 6-8 are higher than those of Examples 2 and 9-10, indicating that when the raw materials of the present invention also include organosilicon-modified acrylic emulsion and waterborne aliphatic polyurethane emulsion, the reflectivity of the aerogel coating is further improved.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An aerogel reflective coating, characterized in that, The raw materials include the following components by weight: 60-80 parts acrylic emulsion, 10-20 parts silica nano-aerogel, 15-20 parts hollow glass microspheres, 10-20 parts filler, 2-4 parts dispersant, 1-2 parts defoamer, 2-3 parts film-forming aid, 2-3 parts leveling agent, and 30-40 parts water. The filler includes titanium dioxide composite material, boron nitride, and kaolin. The titanium dioxide composite material is obtained by doping titanium dioxide with aluminum and then combining it with bismuth tungstate.

2. The aerogel reflective coating according to claim 1, characterized in that, The mass ratio of the titanium dioxide composite material, boron nitride, and kaolin is 10:5:8~12.

3. The aerogel reflective coating according to claim 1, characterized in that, The preparation method of the titanium dioxide composite material includes the following steps: A1. After aluminum nitrate is added to solvent I and dispersed evenly, ethanolamine and tetrabutyl titanate are added and mixed. After drying, crushing and calcining, aluminum-doped titanium dioxide is obtained. A2. After dispersing sodium tungstate dihydrate in solvent II evenly, premixed solution I is obtained; A3. After dispersing bismuth nitrate pentahydrate evenly in solvent III, add hexadecyltrimethylammonium bromide and aluminum-doped titanium dioxide and mix to obtain premixed solution II; A4. After mixing the premixed liquid I with the premixed liquid II, the mixture is washed and dried to obtain the titanium dioxide composite material.

4. The aerogel reflective coating according to claim 3, characterized in that, The mass ratio of tetrabutyl titanate, ethanolamine and aluminum nitrate is 60:62:8~10.

5. The aerogel reflective coating according to claim 3, characterized in that, The mass ratio of sodium tungstate dihydrate, bismuth nitrate pentahydrate, and tetrabutyl titanate is 20:60:80~100.

6. The aerogel reflective coating according to claim 3, characterized in that, In step A1, the mixing time is 1.5 to 2.5 hours.

7. The aerogel reflective coating according to claim 3, characterized in that, In step A1, the calcination temperature is 550~600℃ and the calcination time is 1.5~2.5h.

8. The aerogel reflective coating according to claim 3, characterized in that, In step A4, the mixing temperature is 160~180℃, and the mixing time is 2~3h.

9. An aerogel reflective coating according to claim 1, characterized in that, By weight, the raw materials of the aerogel reflective coating also include 10-15 parts of silicone-modified acrylic emulsion and 5-10 parts of waterborne aliphatic polyurethane emulsion.

10. A method for preparing an aerogel reflective coating, used to prepare the aerogel reflective coating according to any one of claims 1 to 9, characterized in that, Includes the following steps: Water and dispersant are mixed, silica aerogel is added and dispersed, acrylic emulsion, hollow glass microspheres, filler, defoamer, leveling agent and film-forming aid are added in sequence, and stirred to obtain aerogel reflective coating.

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