Porcelain aerogel coating and preparation method thereof

Abstract

The invention relates to the technical field of heat insulation materials, in particular to a ceramic aerogel coating and a preparation method thereof.The ceramic aerogel coating comprises a ceramic anti-corrosion bottom layer, a middle coating and a transparent surface layer, and the preparation method of the ceramic aerogel coating comprises the steps that firstly, sand blasting treatment is conducted on a metal base material; step II, spraying a ceramic anti-corrosion primer, and drying; iII, preparing a floating coat base material; iV, spraying a floating coat base material, and sealing and baking; v, spraying a floating coat fabric, and sealing and baking; step VI, polishing the coating; step VII, spraying transparent finish paint after polishing, and sealing and drying; and step VIII, after unified inspection is completed, finish paint is sprayed, sealing baking is conducted for thorough drying, and then the ceramic aerogel coating is obtained, the prepared ceramic aerogel coating is good in adhesiveness, excellent in acid and alkali resistance, not prone to cracking and peeling, capable of protecting metal for a long time, low in heat conductivity coefficient and high in hardness, and the problems that an existing aerogel coating is high in brittleness, weather resistance and hardness and not prone to cracking and peeling are solved. And the mechanical performance is low.

Description

Technical Field

[0001] The present application relates to the technical field of thermal insulation materials, and more specifically, to a ceramic aerogel coating and a preparation method thereof. Background Art

[0002] With the development of science and technology, the semiconductor industry and the photovoltaic industry have higher and higher requirements for production equipment. Especially in the semiconductor manufacturing process, the cavity equipment needs to maintain strict temperature control and cleanliness to ensure the quality of chip production. Similarly, in photovoltaic equipment, the cavity of the production equipment also needs to have good thermal insulation performance to ensure the stability and energy efficiency of the equipment operation.

[0003] As a new type of porous material, aerogel has been known for its extremely low density, high porosity and excellent thermal insulation properties since it was first synthesized in the 1930s. It has broad application prospects in the outer shells of semiconductor cavities, photovoltaic production equipment cavities and other equipment. However, due to its inherent characteristics, it also has some obvious disadvantages. First, due to its porous structure, aerogel has low mechanical strength and high brittleness, and is prone to break, crush or deform when subjected to force. In addition, due to its porous structure, it is easy to absorb moisture in a humid environment. The structural changes of aerogel will lead to reduced thermal insulation performance and poor durability. Secondly, in the manufacturing process of aerogel, it is necessary to go through a long closed baking and drying stage. This process is not only time-consuming, but also complicated, resulting in low production efficiency. The above problems not only increase the production cost of thermal insulation coatings, but also restrict the promotion and application of aerogel coatings in more fields. Summary of the invention

[0004] In order to solve the technical problems mentioned in the background technology, the present application provides a ceramic aerogel coating and a preparation method thereof.

[0005] In the first aspect, the present application provides a ceramic aerogel coating, which adopts the following technical solution: A ceramic aerogel coating, wherein the ceramic aerogel coating comprises, from top to bottom, a transparent topcoat layer obtained by spraying and curing a transparent topcoat, a midcoat surface layer obtained by spraying and curing a midcoat surface material, a midcoat bottom layer obtained by spraying and curing a midcoat primer, and a ceramic anticorrosive primer layer obtained by spraying and curing a ceramic anticorrosive primer; The middle coating surface is made of the following raw materials in parts by weight: 10-12 parts of aerogel powder, 40-42 parts of resin base material A, 0.5-1 parts of curing agent, 0.5-1 parts of leveling agent, 0.5-1 parts of defoaming agent, 0.5-1 parts of anti-settling agent, 0.5-1 parts of thickener, and 80-100 parts of toluene; The raw material formula of the mid-coat base material is as follows: perlite accounting for 10-50% of the total raw materials is added to the raw material formula of the mid-coat surface.

[0006] Preferably, the preparation of the ceramic anticorrosive primer comprises the following steps: Step ①, grind and sieve the ceramic filler, stir and evenly disperse it in DMF, add the polymer, continue stirring, filter, wash and dry after stirring evenly, to obtain intermediate product A; Step ②, heat-treating the intermediate product A and then cooling it naturally to obtain a modified ceramic filler; Step ③, put the modified ceramic filler and the anti-corrosion primer in a mass ratio of 1-3:8-10 into a high-speed disperser for grinding and dispersion, fully stir and mix, and evenly filter to obtain the ceramic anti-corrosion primer.

[0007] Preferably, the ceramic filler is composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1-3:2-4:2-3.

[0008] Preferably, the high molecular polymer is composed of polyimide and polyethersulfone in a ratio of 1-2:2-3.

[0009] Preferably, the heat treatment comprises a preheating temperature of 60-80°C, a preheating treatment time of 30-40 minutes, a curing temperature of 80-150°C, and a curing treatment time of 1-3 hours.

[0010] Preferably, the preparation of the mid-coated surface comprises the following steps: Step A, subjecting aerogel powder to ultrasonic dispersion treatment in 1 / 3-2 / 3 parts by weight of toluene to obtain an aerogel dispersion; Step B, dispersing the resin base material A in the remaining toluene to obtain a resin solution A; Step C, mixing the aerogel dispersion and the resin solution A, adding a curing agent, a leveling agent, a defoaming agent, an anti-settling agent, and a thickener, and stirring with a high-speed disperser until the mixture is uniformly mixed to obtain a mid-coated surface; Preferably, the resin base material A is composed of silicone resin, polyurethane resin and acrylic resin in a mass ratio of 1-2:2-3:1-3.

[0011] Preferably, the perlite is modified perlite hollow floating beads of 90-120 mesh.

[0012] Preferably, the preparation of the modified perlite hollow floating beads comprises the following steps: Step (1), soaking, washing, filtering, and drying the hollow pearlite beads at 100-120° C. for 1-2 hours; Step (2), adding the dried hollow pearlite beads and carbon fibers to the silane coupling agent solution, stirring and mixing, and heating the mixture at 80-90° C. for 1-2 hours to obtain a mixed solution A; Step (3), adding fatty acid to the mixed solution A, mixing evenly, heating at 90-110° C. for 1-2 h, filtering, drying and sieving to obtain modified perlite hollow floating beads.

[0013] Preferably, the mass ratio of the perlite hollow floating beads, carbon fiber and silane coupling agent is 5-8:1-3:25-35, and the silane coupling agent is a 3-aminopropyl triethoxysilane ethanol solution with a mass concentration of 1-3%.

[0014] Preferably, the curing agent is diethylenetriamine or phthalic anhydride; the leveling agent is polyether modified silicone oil or fluorine surfactant; the defoaming agent is an organosilicon defoaming agent or a polyether defoaming agent, and the anti-settling agent is fumed silica; the thickener is a polyurethane thickener or a cellulose thickener.

[0015] In a second aspect, the present application provides a method for preparing a ceramic aerogel coating, using the following technical solution: A method for preparing a ceramic aerogel coating comprises the following steps: Step Ⅰ: After cleaning the surface of the metal substrate, perform sandblasting; Step II, spray the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, spray once, dry at 90-110°C for 1-2h, spray once again, and continue drying at 110-120°C for 1-2h to obtain a ceramic anticorrosion primer layer with a thickness of 28-32μm; Step III, add modified perlite hollow floating beads to the middle coating surface, heat to 60-80°C, stir and mix evenly, and cool naturally to obtain the middle coating base material; Step IV, continue to spray 3-5mm mid-coat primer on the surface of the ceramic anti-corrosion primer layer, control the sealing and baking temperature to 80-85°C, seal and bake for 30-40 minutes, then 100-150°C, continue to seal and bake for 2-4 hours, to obtain the mid-coat bottom layer; Step V, continue to spray 2-4 mm of the middle coating surface on the surface of the middle coating bottom layer, control the sealing and baking temperature to 80-85°C, seal and bake for 1-2 hours, then 140-160°C, continue to seal and bake for 1-2 hours, to obtain the middle coating surface layer; Step VI, grind the middle coating surface after sealing and baking twice, the first time with 360 mesh air grinder, the second time with 400 mesh sandpaper, and control the total coating thickness to 4-6mm; Step VII: spraying a transparent topcoat on the polished coating surface, and sealing and baking; Step VIII: After unified inspection, spray transparent topcoat twice and seal and bake to dry thoroughly.

[0016] Preferably, the spraying method in step VII is to continuously spray the transparent topcoat 2-4 times, and continuously bake at 80-85°C for 3-6h, or spray one coat of transparent topcoat, bake at 80-85°C for 15-60min, and spray 2-4 times.

[0017] Preferably, in step VIII, water-based color paste or metal powder is added to the transparent topcoat and stirred evenly to obtain a dyed topcoat; Preferably, the specific sealing and baking method in step VIII is to seal and bake at 80-85°C for 30-40 minutes, then seal and bake at 150-160°C for 1-2 hours, or dry at room temperature for 6-12 hours, and then seal and bake at 60-80°C to dry thoroughly.

[0018] In summary, this application has the following beneficial effects: The present application utilizes a mixture of high molecular polymer and ceramic filler to improve the hydrophilicity / lipophilicity of the ceramic filler surface, help prevent agglomeration of filler particles, enhance the interfacial bonding strength between the filler and the resin matrix, and improve the adhesion of the ceramic anti-corrosion primer to the metal substrate. The ceramic filler itself has good high temperature resistance, and the modification treatment can further improve its thermal stability and reduce the thermal conductivity of the ceramic anti-corrosion primer, further improving its thermal insulation performance.

[0019] The present application adds a compound of hollow perlite beads and carbon fibers to the aerogel midcoat base layer and performs surface treatment on the compound, thereby retaining the thermal insulation effect of the hollow perlite beads. The porous structure increases the surface area inside the coating, which helps the solvent to diffuse from the inside of the coating to the surface more quickly. The hollow structure can reduce the resistance encountered when the solvent evaporates, enabling it to achieve quick-drying characteristics. The shortcomings of the hollow perlite beads, such as poor mechanical properties, high brittleness, easy fracture, crushing or deformation when subjected to force, and easy moisture absorption in a humid environment, are improved overall. The surface of the hollow perlite beads is activated and the bonding force with the resin is increased, thereby significantly improving its dispersibility and compatibility in the resin matrix. Stearic acid treatment can introduce hydrophobic long-chain alkyl groups on the surface of the hollow perlite beads, increase their roughness and hardness, and reduce water absorption, thereby improving their mechanical properties and durability.

[0020] The present application adopts a multi-layer spraying and layer-by-layer drying method to ensure the uniformity, thickness and density of the coating, reduce bubbles and pores, and avoid sagging and unevenness between the coatings, thereby improving the flatness of the coating. The modified perlite hollow floating beads have a lower thermal conductivity, which can effectively reduce heat transfer and improve the thermal insulation performance of the coating. Through multi-layer spraying and gradual drying, a dense and uniform thermal insulation layer can be formed. Gradual drying ensures the density and thermal insulation effect of the coating, and the final high-temperature sealing and baking can further improve the density and stability of the coating and enhance the thermal insulation effect of the coating. The coating prepared by this preparation method not only has a good appearance and touch, but also has excellent thermal insulation and heat preservation performance, and is particularly suitable for the thermal insulation of various metal equipment such as photovoltaic production equipment cavities, including but not limited to: photovoltaic production equipment cavities, industrial furnaces and reactors, pipelines and storage tanks. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 These are finished pictures of the ceramic aerogel coatings prepared in Example 1 and Comparative Example 8. DETAILED DESCRIPTION

[0022] The present application is further described in detail below in conjunction with embodiments.

[0023] Embodiments 1-3 provide a ceramic aerogel coating and a preparation method thereof. The anticorrosive primer used in the embodiments of the present invention and the comparative examples was purchased from Ba Strontium Fluoride (Wuxi) New Materials Technology Co., Ltd. (product model: GLT990); the transparent topcoat was purchased from Xi'an Youxin Hengye New Materials Co., Ltd. (product number: Y0038); the perlite empty floating beads were purchased from Lingshou County Wanzhu Mineral Products Co., Ltd. (product specification: 2-43); the polyurethane resin was purchased from Foshan Wengkaier Trading Co., Ltd. (product model: PUD-107A); the acrylic resin was purchased from Jiangyin Liren Chemical Co., Ltd. (brand: 866B); the silicone resin was purchased from Shenzhen Jipeng Silicon Fluorine Materials Co., Ltd. (product model: 9611); the aerogel powder was purchased from Fusman Technology (Beijing) Co., Ltd. (brand number: 1407014-10kg); the polyimide (brand: PD-400) was purchased from Dongguan Taotao Plastic Raw Materials Co., Ltd.; the polyether sulfone (brand: E2010) was purchased from Shanghai Liangrun International Trade Co., Ltd. Company; carbon fiber was purchased from Cangzhou Zhongli New Material Technology Co., Ltd. (ZL-CF200); alumina (article number: 96521007) and silicon carbide (article number: 10021) were purchased from Nangong Jingrui Alloy Products Co., Ltd.; silicon dioxide (model: SP-10) and fumed silica anti-settling agent (model: 10NM) were purchased from Shanghai Huijingya Nano New Materials Co., Ltd.; curing agent diethylenetriamine was purchased from Boxuan Chemical (Shandong) Co., Ltd.; polyether modified silicone oil leveling agent (article number: 601) was purchased from Yantai Shunming New Materials Co., Ltd.; silicone defoamer (model: BWF-WB880) was purchased from Guangdong Bawofu Environmental Protection Technology Co., Ltd.; polyurethane thickener (model: C-101) was purchased from Guangdong Zhonglian Federation Fine Chemical Co., Ltd.

[0024] Example 1 A ceramic aerogel coating, which comprises, from top to bottom, a transparent topcoat layer obtained by spraying and curing a transparent topcoat, a midcoat surface layer obtained by spraying and curing a midcoat surface material, a midcoat bottom layer obtained by spraying and curing a midcoat primer, and a ceramic anticorrosive primer layer obtained by spraying and curing a ceramic anticorrosive primer; The middle coating surface is made of the following raw materials in parts by weight: 10 parts of aerogel powder, 40 parts of resin base material A, 0.5 parts of curing agent, 0.5 parts of leveling agent, 0.5 parts of defoaming agent, 0.5 parts of anti-settling agent, 0.5 parts of thickener, and 80 parts of toluene; The raw material formula of the mid-coat base material is: add perlite accounting for 10% of the total raw materials to the raw material formula of the mid-coat surface.

[0025] Wherein, the preparation of ceramic anticorrosive primer comprises the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1:2:2 through a 90-mesh sieve, stirring at 200 rpm for 30 minutes, and evenly dispersing in DMF, adding a polymer of polyimide and polyether sulfone in a mass ratio of 1:2, controlling the mass ratio of the ceramic filler, the polymer and the solvent DMF to be 1:0.01:9, continuing to stir for 30 minutes, after stirring evenly, filtering, washing, and drying at 100°C for 2 hours to obtain an intermediate product A; Step ②, preheating the intermediate product A at 60°C for 30 min, curing at 120°C for 1 h, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 1:8 into a high-speed disperser for dispersion, control the speed to 200 rpm at a temperature of 50°C, stir for 40 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0026] The preparation of the mid-coated surface comprises the following steps: Step A, subjecting the aerogel powder to ultrasonic dispersion treatment in 1 / 3 weight portion of toluene, controlling the ultrasonic power to 300 W, the ultrasonic frequency to 30 kHz, the ultrasonic time to 30 min, the ultrasonic interval time to 20 s on, and 10 s off, to obtain an aerogel dispersion; Step B, dispersing silicone resin, polyurethane resin and acrylic resin in a mass ratio of 1:2:1 in the remaining toluene, stirring while adding, controlling the stirring speed to 300 rpm, stirring at 50° C. for 20 minutes, to obtain resin solution A; Step C, mixing the aerogel dispersion and the resin solution A according to weight parts, adding a curing agent, a leveling agent, a defoaming agent, an anti-settling agent, and a thickener, stirring using a high-speed disperser, stirring at a speed of 600 rpm, stirring at room temperature for 30 minutes, until the mixture is uniformly mixed, to obtain a mid-coated surface; A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 90°C for 1 hour, spraying once again, and continuing to dry at 110°C for 1 hour to obtain a ceramic anticorrosion primer layer with a thickness of 28 μm; Step III, add modified perlite hollow floating beads to the middle coating surface, heat to 60°C, stir at a speed of 600 rpm for 20 minutes, stir evenly, and cool naturally to obtain the middle coating base material; The preparation of the modified perlite hollow floating beads specifically includes the following steps: Step (1), soaking the hollow pearlite beads in 60°C deionized water for 1 hour, washing, filtering, and drying at 100°C for 1 hour; Step (2), mixing hollow pearlite beads, carbon fibers and a silane coupling agent in a mass ratio of 5:1:25, wherein the silane coupling agent is a 3-aminopropyltriethoxysilane ethanol solution with a mass concentration of 1%, stirring at a speed of 200 rpm for 1 hour, and after mixing evenly, heating the mixture at 80° C. for 1 hour to obtain a mixed solution A; Step (3), mixing the mixed solution A with a 2% stearic acid ethanol solution in a mass ratio of 9:1, heating at 90° C. for 1 h, filtering, drying at 120° C. for 3 h, and passing through a 90-mesh sieve to obtain modified perlite hollow floating beads; Step IV, continue to spray 3mm mid-coat primer on the surface of the ceramic anticorrosive primer layer, control the sealing and baking temperature to 80°C, seal and bake for 30 minutes, and then continue to seal and bake at 100°C for 2 hours to obtain the mid-coat bottom layer; Step V, continue to spray 2mm of the middle coating surface on the surface of the middle coating bottom layer according to the above method, control the sealing and baking temperature to 80°C, seal and bake for 1 hour, then 140°C, continue to seal and bake for 1 hour, to obtain the middle coating surface layer; Step VI, grind the middle coating surface layer after sealing and baking twice, the first time with 360 mesh air grinding, the second time with 400 mesh sandpaper, and control the total coating thickness to 4mm; Step VII: spraying transparent topcoat twice on the polished coating surface, and baking at 80°C for 3 hours; Step VIII: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 80°C for 30 minutes, and then seal and bake at 150°C for 1 hour to thoroughly dry, so as to obtain the porcelain aerogel coating.

[0027] Example 2 A ceramic aerogel coating, which comprises, from top to bottom, a transparent topcoat layer obtained by spraying and curing a transparent topcoat, a midcoat surface layer obtained by spraying and curing a midcoat surface material, a midcoat bottom layer obtained by spraying and curing a midcoat primer, and a ceramic anticorrosive primer layer obtained by spraying and curing a ceramic anticorrosive primer; The middle coating surface is made of the following raw materials in parts by weight: 11 parts of aerogel powder, 41 parts of resin base material A, 0.8 parts of curing agent, 0.8 parts of leveling agent, 0.8 parts of defoaming agent, 0.8 parts of anti-settling agent, 0.8 parts of thickener, and 90 parts of toluene; The raw material formula of the mid-coat base material is: add perlite accounting for 30% of the total raw materials to the raw material formula of the mid-coat surface.

[0028] Wherein, the preparation of ceramic anticorrosive primer comprises the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 2:3:2.5 through a 110 mesh sieve, stirring at 250rpm for 35min, and evenly dispersing in DMF, adding a polymer of polyimide and polyethersulfone in a mass ratio of 1.5:2.5, controlling the mass ratio of the ceramic filler, the polymer and the solvent DMF to be 1.5:0.03:9.5, continuing to stir for 35min, after stirring evenly, filtering, washing, and drying at 110°C for 2.5h to obtain an intermediate product A; Step ②, preheating the intermediate product A at 70°C for 35 minutes, curing at 135°C for 2 hours, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 2:9 into a high-speed disperser for dispersion, control the speed to 250 rpm at a temperature of 60°C, stir for 50 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0029] The preparation of the mid-coated surface comprises the following steps: Step A, subjecting the aerogel powder to ultrasonic dispersion treatment in 1 / 2 weight part of toluene, controlling the ultrasonic power to 300 W, the ultrasonic frequency to 30 kHz, the ultrasonic time to 30 min, the ultrasonic interval time to 20 s on, and 10 s off, to obtain an aerogel dispersion; Step B, dispersing silicone resin, polyurethane resin and acrylic resin in a mass ratio of 1.5:2.5:2 in the remaining toluene, stirring while adding, controlling the stirring speed to 350 rpm, stirring at 55° C. for 25 minutes, to obtain resin solution A; Step C, mixing the aerogel dispersion and the resin solution A according to weight parts, adding a curing agent, a leveling agent, a defoaming agent, an anti-settling agent, and a thickener, stirring using a high-speed disperser, stirring at a speed of 700 rpm, stirring at room temperature for 35 minutes, until the mixture is uniformly mixed, to obtain a mid-coated surface; A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 100°C for 1-2h, spraying once again, and continuing to dry at 115°C for 1.5h to obtain a ceramic anticorrosion primer layer with a thickness of 30μm; Step III, add modified perlite hollow floating beads to the middle coating surface, heat to 70°C, stir at a speed of 700 rpm for 25 minutes, stir evenly, and cool naturally to obtain the middle coating base material; The preparation of the modified perlite hollow floating beads specifically includes the following steps: Step (1), soaking the hollow pearlite beads in 65°C deionized water for 1.5 hours, washing, filtering, and drying at 110°C for 1.5 hours; Step (2), mixing hollow pearlite beads, carbon fibers and a silane coupling agent in a mass ratio of 6:2:30, wherein the silane coupling agent is a 3-aminopropyltriethoxysilane ethanol solution with a mass concentration of 2%, stirring at a speed of 250 rpm for 1.5 hours, and after mixing evenly, heating the mixture at 85° C. for 1.5 hours to obtain a mixed solution A; Step (3), mixing the mixed solution A with a 3% stearic acid ethanol solution in a mass ratio of 9:1, heating the mixture at 100° C. for 1.5 h, filtering, drying at 150° C. for 4 h, and passing through a 110-mesh sieve to obtain modified perlite hollow floating beads; Step IV: Continue to spray 4 mm of mid-coat primer on the surface of the ceramic anticorrosive primer layer, control the sealing and baking temperature to 82°C, seal and bake for 35 minutes, and then continue to seal and bake at 125°C for 3 hours to obtain the mid-coat bottom layer; Step V, continue to spray 3mm of the middle coating surface on the surface of the middle coating bottom layer according to the above method, control the sealing and baking temperature to 82°C, seal and bake for 1.5 hours, then 150°C, continue to seal and bake for 1.5 hours, to obtain the middle coating surface layer; Step VI, grind the middle coating surface after sealing and baking twice, the first time with 360 mesh air grinder, the second time with 400 mesh sandpaper, and control the total coating thickness to 5mm; Step VII: spray the polished coating surface with a transparent topcoat three times continuously, and bake it at 82°C for 4.5 hours to dry; Step VIII: After unified inspection, spray the transparent topcoat twice according to the above method, dry at room temperature for 9 hours, and then seal and bake at 70℃ to dry thoroughly.

[0030] Example 3 A ceramic aerogel coating, which comprises, from top to bottom, a transparent topcoat layer obtained by spraying and curing a transparent topcoat, a midcoat surface layer obtained by spraying and curing a midcoat surface material, a midcoat bottom layer obtained by spraying and curing a midcoat primer, and a ceramic anticorrosive primer layer obtained by spraying and curing a ceramic anticorrosive primer; The middle coating surface is made of the following raw materials in parts by weight: 12 parts of aerogel powder, 42 parts of resin base material A, 1 part of curing agent, 1 part of leveling agent, 1 part of defoaming agent, 1 part of anti-settling agent, 1 part of thickener, and 100 parts of toluene; The raw material formula of the mid-coat base material is: add perlite accounting for 50% of the total raw materials to the raw material formula of the mid-coat surface.

[0031] Wherein, the preparation of ceramic anticorrosive primer comprises the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 3:4:3 through a 120-mesh sieve, stirring at 300 rpm for 40 minutes, and evenly dispersing in DMF, adding a polymer of polyimide and polyether sulfone in a mass ratio of 2:3, controlling the mass ratio of the ceramic filler, the polymer and the solvent DMF to be 2:0.05:10, continuing to stir for 40 minutes, after stirring evenly, filtering, washing, and drying at 120°C for 3 hours to obtain an intermediate product A; Step ②, preheating the intermediate product A at 80°C for 40 min, curing at 150°C for 3 h, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 3:10 into a high-speed disperser for dispersion, control the speed to 300 rpm at a temperature of 70°C, stir for 60 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0032] The preparation of the mid-coated surface comprises the following steps: Step A, subjecting the aerogel powder to ultrasonic dispersion treatment in 2 / 3 parts by weight of toluene, controlling the ultrasonic power to 300 W, the ultrasonic frequency to 30 kHz, the ultrasonic time to 30 min, the ultrasonic interval time to 20 s on, and 10 s off, to obtain an aerogel dispersion; Step B, dispersing silicone resin, polyurethane resin and acrylic resin in a mass ratio of 2:3:3 in the remaining toluene, stirring while adding, controlling the stirring speed to 400 rpm, stirring at 60° C. for 30 minutes, to obtain resin solution A; Step C, mixing the aerogel dispersion and the resin solution A according to weight parts, adding a curing agent, a leveling agent, a defoaming agent, an anti-settling agent, and a thickener, stirring using a high-speed disperser, stirring at a speed of 800 rpm, stirring at room temperature for 40 minutes, until the mixture is uniformly mixed, to obtain a mid-coated surface; A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, sandblast the 90-mesh aluminum oxide at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 110°C for 2 hours, spraying once again, and continuing to dry at 120°C for 2 hours to obtain a ceramic anticorrosion primer layer with a thickness of 32 μm; Step III, add modified perlite hollow floating beads to the middle coating surface, heat to 80°C, stir at a speed of 800 rpm for 30 minutes, stir evenly, and cool naturally to obtain the middle coating base material; The preparation of the modified perlite hollow floating beads specifically includes the following steps: Step (1), soaking the hollow pearlite beads in 70°C deionized water for 2 hours, washing, filtering, and drying at 120°C for 2 hours; Step (2), mixing hollow pearlite beads, carbon fibers and a silane coupling agent in a mass ratio of 8:3:35, wherein the silane coupling agent is a 3% 3-aminopropyltriethoxysilane ethanol solution, stirring at a speed of 300 rpm for 2 h, and after mixing evenly, heating the mixture at 90° C. for 2 h to obtain a mixed solution A; Step (3), mixing the mixed solution A with a 5% stearic acid ethanol solution in a mass ratio of 9:1, heating the mixture at 110° C. for 2 h, filtering, drying at 180° C. for 5 h, and passing through a 120-mesh sieve to obtain modified perlite hollow floating beads; Step IV: Continue to spray 5 mm of mid-coat primer on the surface of the ceramic anticorrosive primer layer, control the sealing and baking temperature to 85°C, seal and bake for 40 minutes, and then continue to seal and bake at 150°C for 4 hours to obtain the mid-coat bottom layer; Step V, continue to spray 4mm of the middle coating surface on the surface of the middle coating bottom layer according to the above method, control the sealing and baking temperature to 85°C, seal and bake for 2 hours, then 160°C, continue to seal and bake for 2 hours, to obtain the middle coating surface layer; Step VI, grind the middle coating surface layer after sealing and baking twice, the first time with 360 mesh air grinder, the second time with 400 mesh sandpaper, and control the total coating thickness to 6mm; Step VII: spraying the polished coating surface with a transparent topcoat 4 times continuously, and baking at 85°C for 6 hours continuously; Step VIII: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 85°C for 40 minutes, and then seal and bake at 160°C for 2 hours to completely dry, so as to obtain the porcelain aerogel coating.

[0033] Comparative Example 1 This comparative example is the same as Example 1, except that the preparation method of the ceramic anticorrosive primer is different, as follows: The preparation of ceramic anticorrosive primer includes the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1:2:2 through a 90-mesh sieve, stirring at 200 rpm for 30 minutes, and evenly dispersing in DMF, controlling the mass ratio of the ceramic filler to the solvent DMF to be 1:9, continuing to stir for 30 minutes, and after stirring evenly, filtering, washing, and drying at 100°C for 2 hours to obtain an intermediate product A; Step ②, preheating the intermediate product A at 60°C for 30 min, curing at 120°C for 1 h, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 1:8 into a high-speed disperser for dispersion, control the speed to 200 rpm at a temperature of 50°C, stir for 40 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0034] Comparative Example 2 This comparative example is the same as Example 1, except that the preparation method of the ceramic anticorrosive primer is different, as follows: The preparation of ceramic anticorrosive primer includes the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1:2:2 through a 90-mesh sieve, stirring at 200 rpm for 30 minutes, and evenly dispersing in DMF, adding polyimide, controlling the mass ratio of ceramic filler, polyimide and solvent DMF to be 1:0.01:9, continuing to stir for 30 minutes, after stirring evenly, filtering, washing, and drying at 100°C for 2 hours to obtain intermediate product A; Step ②, preheating the intermediate product A at 60°C for 30 min, curing at 120°C for 1 h, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 1:8 into a high-speed disperser for dispersion, control the speed to 200 rpm at a temperature of 50°C, stir for 40 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0035] Comparative Example 3 This comparative example is the same as Example 1, except that the preparation method of the ceramic anticorrosive primer is different, as follows: The preparation of ceramic anticorrosive primer includes the following steps: Step ①, grinding a ceramic filler composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1:2:2 through a 90-mesh sieve, stirring at 200 rpm for 30 minutes, and evenly dispersing in DMF, adding polyethersulfone, controlling the mass ratio of ceramic filler, polyethersulfone and solvent DMF to be 1:0.01:9, continuing to stir for 30 minutes, after stirring evenly, filtering, washing, and drying at 100°C for 2 hours to obtain intermediate product A; Step ②, preheating the intermediate product A at 60°C for 30 min, curing at 120°C for 1 h, and naturally cooling to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anti-corrosion primer in a mass ratio of 1:8 into a high-speed disperser for dispersion, control the speed to 200 rpm at a temperature of 50°C, stir for 40 minutes, fully stir and mix, and filter to obtain the ceramic anti-corrosion primer.

[0036] Comparative Example 4 This comparative example is the same as Example 1, except that the preparation method of the modified perlite hollow floating beads added during the preparation of the midcoat primer is different, as follows: The preparation of modified perlite hollow floating beads specifically includes the following steps: Step (1), soaking the hollow pearlite beads in 60°C deionized water for 1 hour, washing, filtering, and drying at 100°C for 1 hour; Step (2), mixing hollow pearlite beads and a silane coupling agent in a mass ratio of 5:25, wherein the silane coupling agent is a 1% mass concentration 3-aminopropyltriethoxysilane ethanol solution, stirring at a speed of 200 rpm for 1 hour, and after mixing evenly, heating the mixture at 80° C. for 1 hour to obtain a mixed solution A; Step (3), mixing the mixed solution A with a 2% stearic acid ethanol solution in a mass ratio of 9:1, heating at 90°C for 1h, filtering, drying at 120°C for 3h, and passing through a 90-mesh sieve to obtain modified perlite hollow floating beads.

[0037] Comparative Example 5 This comparative example is the same as Example 1, except that the preparation method of the modified perlite hollow floating beads added during the preparation of the midcoat primer is different, as follows: The preparation of modified perlite hollow floating beads specifically includes the following steps: Step (1), soaking the hollow pearlite beads in 60°C deionized water for 1 hour, washing, filtering, and drying at 100°C for 1 hour; Step (2), mixing hollow pearlite beads, carbon fibers and a silane coupling agent in a mass ratio of 5:1:25, wherein the silane coupling agent is a 1% mass concentration 3-aminopropyltriethoxysilane ethanol solution, stirring at a speed of 200 rpm for 1 hour, and after mixing evenly, heating the mixture at 80° C. for 1 hour to obtain a mixed solution A; Step (3), heating the mixed solution A at 90° C. for 1 h, filtering, drying at 120° C. for 3 h, and passing through a 90-mesh sieve to obtain modified perlite hollow floating beads.

[0038] Comparative Example 6 This comparative example is the same as Example 1, except that hollow pearlite beads are added during the preparation of the midcoat base material without modification, as follows: A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 90°C for 1 hour, spraying once again, and continuing to dry at 110°C for 1 hour to obtain a ceramic anticorrosion primer layer with a thickness of 28 μm; Step III, adding perlite hollow floating beads to the middle coating surface, heating to 60°C, stirring at a speed of 600 rpm for 20 minutes, stirring evenly, and cooling naturally to obtain the middle coating base material; Step IV, continue to spray 3mm mid-coat primer on the surface of the ceramic anticorrosive primer layer, control the sealing and baking temperature to 80°C, seal and bake for 30 minutes, and then continue to seal and bake at 100°C for 2 hours to obtain the mid-coat bottom layer; Step V, continue to spray 2mm of the middle coating surface on the surface of the middle coating bottom layer according to the above method, control the sealing and baking temperature to 80°C, seal and bake for 1 hour, then 140°C, continue to seal and bake for 1 hour, to obtain the middle coating surface layer; Step VI, grind the middle coating surface layer after sealing and baking twice, the first time with 360 mesh air grinding, the second time with 400 mesh sandpaper, and control the total coating thickness to 4mm; Step VII: spraying transparent topcoat twice on the polished coating surface, and baking at 80°C for 3 hours; Step VIII: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 80°C for 30 minutes, and then seal and bake at 150°C for 1 hour to thoroughly dry, so as to obtain the porcelain aerogel coating.

[0039] Comparative Example 7 This comparative example is the same as Example 1, except that modified perlite hollow floating beads are added to the middle coating surface, and modified perlite hollow floating beads are not added to the middle coating base material, specifically as follows: A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 90°C for 1 hour, spraying once again, and continuing to dry at 110°C for 1 hour to obtain a ceramic anticorrosion primer layer with a thickness of 28 μm; Step III, continue to spray 3mm mid-coat primer on the surface of the ceramic anti-corrosion primer layer, control the sealing and baking temperature to 80°C, seal and bake for 30 minutes, and then continue to seal and bake at 100°C for 2 hours to obtain the mid-coat bottom layer; Step IV, add modified perlite hollow floating beads to the mid-coat base material, heat to 60°C, stir at a speed of 600 rpm for 20 minutes, stir evenly, and cool naturally to obtain a mid-coat surface; Step V, continue to spray 2mm of the middle coating surface on the surface of the middle coating bottom layer according to the above method, control the sealing and baking temperature to 80°C, seal and bake for 1 hour, then 140°C, continue to seal and bake for 1 hour, to obtain the middle coating surface layer; Step VI, grind the middle coating surface layer after sealing and baking twice, the first time with 360 mesh air grinding, the second time with 400 mesh sandpaper, and control the total coating thickness to 4mm; Step VII: spraying transparent topcoat twice on the polished coating surface, and baking at 80°C for 3 hours; Step VIII: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 80°C for 30 minutes, and then seal and bake at 150°C for 1 hour to thoroughly dry, so as to obtain the porcelain aerogel coating.

[0040] Comparative Example 8 This comparative example is the same as Example 1, except that the mid-coat surface is replaced with a mid-coat base material, as follows: A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 90°C for 1 hour, spraying once again, and continuing to dry at 110°C for 1 hour to obtain a ceramic anticorrosion primer layer with a thickness of 28 μm; Step III, add 10% of the total raw materials of the middle coating material to the middle coating material, heat to 60°C, stir at a speed of 600rpm for 20min, stir evenly, and then cool the middle coating base material A naturally; Step IV: Continue to spray 5 mm of mid-coat primer A on the surface of the ceramic anticorrosive primer layer, control the sealing and baking temperature to 80°C, seal and bake for 1.5 hours, and then continue to seal and bake at 140°C for 3 hours to obtain the mid-coat bottom layer; Step V, grind the bottom layer of the middle coating after sealing and baking twice, the first time with 360 mesh air grinding, the second time with 400 mesh sandpaper, and control the total thickness of the coating to 4mm; Step VI: spray the polished coating surface with a transparent topcoat twice continuously, and bake at 80°C for 3 hours to dry; Step VII: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 80°C for 30 minutes, and then seal and bake at 150°C for 1 hour to thoroughly dry, so as to obtain the porcelain aerogel coating.

[0041] Comparative Example 9 This comparative example is the same as Example 1, except that the midcoat base material is replaced with a midcoat surface material, as follows: A method for preparing a ceramic aerogel coating comprises the following steps: Step I: After cleaning the surface of the metal substrate, 80-mesh aluminum oxide was sandblasted at a spraying angle of 60° and a distance of 100 mm at a spraying pressure of 0.75 MPa for 15 minutes; Step II, spraying the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, with a spraying pressure of 0.4 MPa and a spraying angle of 60°. After spraying once, drying at 90°C for 1 hour, spraying once again, and continuing to dry at 110°C for 1 hour to obtain a ceramic anticorrosion primer layer with a thickness of 28 μm; Step III, continue to spray 5mm mid-coat surface on the surface of the ceramic anti-corrosion primer layer, control the sealing and baking temperature to 80°C, seal and bake for 1.5 hours, and then continue to seal and bake at 100°C for 3 hours to obtain the mid-coat surface layer; Step IV, grind the middle coating after sealing and baking twice, the first time with 360 mesh air grinder, the second time with 400 mesh sandpaper, and control the total thickness of the coating to 4mm; Step V, spraying the polished coating surface with a transparent topcoat twice continuously, and baking at 80°C for 3 hours to dry; Step VI: After uniform inspection, spray the transparent topcoat twice according to the above method, seal and bake at 80°C for 30 minutes, and then seal and bake at 150°C for 1 hour to completely dry, so as to obtain the porcelain aerogel coating.

[0042] Performance Testing The comprehensive properties of the ceramic aerogel coatings prepared in Examples 1-3 and Comparative Examples 1-9 of the present application are as follows: Adhesion test: Tested in accordance with national standard GB / T 5210-2006; Thermal conductivity: refer to the international standard ASTME1461-01 to test the thermal conductivity of the sample coating; Coating wear rate: The coating wear rate of the sample coating is tested according to the international standard ASTM G65. The sample is tested using a Taber abrasion machine. The test conditions are: using a friction material CS-10 grinding wheel, a load of 500g, and testing the coating wear rate at 500 revolutions; Hardness: Tested in accordance with the international standard ASTM E384-2017; Corrosion resistance test: Tested in accordance with national standard GB / T9274-1988; The specific test results are shown in Table 1 below.

[0043] Table 1 Performance parameters of the ceramic aerogel coatings prepared in Examples 1-3 and Comparative Examples 1-9

[0044] The present application discloses a ceramic aerogel coating, which is composed of Table 1 and Figure 1 It can be seen that the ceramic aerogel coating prepared in the present application has extremely strong adhesion, outstanding acid and alkali resistance, is not easy to crack and peel off, can play a long-term protective role on metals, and has low thermal conductivity and high hardness, which solves the defects of existing aerogel coatings such as high brittleness, weather resistance, and low mechanical properties. Figure 1 These are finished product pictures of the porcelain aerogel coatings prepared by Example 1 (left) and Comparative Example 8 (right). Modified perlite hollow floating beads are added to both the middle coating surface and the middle coating base material of Comparative Example 8. The perlite hollow floating beads are lightweight particles of a certain size, which may cause slight unevenness on the coating surface, affecting the smoothness and flatness of the final coating. If the aerogel layer is thick, small bubbles or voids will be formed in the coating during the drying process. These bubbles will leave traces after drying, and the uneven distribution may lead to insufficient thermal insulation performance or decreased mechanical properties in local areas.

[0045] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A ceramic aerogel coating, characterized in that: The ceramic aerogel coating is composed of, from top to bottom, a transparent topcoat layer obtained by spraying and curing a transparent topcoat, a midcoat surface layer obtained by spraying and curing a midcoat surface material, a midcoat bottom layer obtained by spraying and curing a midcoat base material, and a ceramic anticorrosive primer layer obtained by spraying and curing a ceramic anticorrosive primer; The middle coating surface is made of the following raw materials in parts by weight: 10-12 parts of aerogel powder, 40-42 parts of resin base material A, 0.5-1 parts of curing agent, 0.5-1 parts of leveling agent, 0.5-1 parts of defoaming agent, 0.5-1 parts of anti-settling agent, 0.5-1 parts of thickener, and 80-100 parts of toluene; The raw material formula of the mid-coat base material is as follows: perlite accounting for 10-50% of the total raw materials is added to the raw material formula of the mid-coat surface.

2. The ceramic aerogel coating according to claim 1, characterized in that: The preparation of the ceramic anticorrosive primer comprises the following steps: Step ①, grind and sieve the ceramic filler, stir and evenly disperse it in DMF, add the polymer, continue stirring, filter, wash and dry after stirring evenly, to obtain intermediate product A; Step ②, heat-treating the intermediate product A and then cooling it naturally to obtain a modified ceramic filler; Step ③, add the modified ceramic filler and the anticorrosive primer in a mass ratio of 1-3:8-10 into a high-speed disperser for dispersion, fully stir and mix, and filter to obtain the ceramic anticorrosive primer.

3. The ceramic aerogel coating according to claim 2, characterized in that: The ceramic filler is composed of alumina, silicon dioxide and silicon carbide in a mass ratio of 1-3:2-4:2-3; the high molecular polymer is composed of polyimide and polyether sulfone in a mass ratio of 1-2:2-3; the heat treatment is specifically a preheating temperature of 60-80°C, a preheating treatment of 30-40 minutes, a curing temperature of 120-150°C, and a curing treatment of 1-3 hours.

4. The ceramic aerogel coating according to claim 1, characterized in that: The preparation of the mid-coated surface comprises the following steps: Step A, subjecting aerogel powder to ultrasonic dispersion treatment in 1 / 3-2 / 3 parts by weight of toluene to obtain an aerogel dispersion; Step B, dispersing the resin base material A in the remaining toluene to obtain a resin solution A; Step C: Mix the aerogel dispersion and the resin solution A, add a curing agent, a leveling agent, a defoaming agent, an anti-settling agent, and a thickener, and stir using a high-speed disperser until the mixture is evenly mixed to obtain a mid-coated surface.

5. The ceramic aerogel coating according to claim 1, characterized in that: The resin base material A is composed of silicone resin, polyurethane resin and acrylic resin in a mass ratio of 1-2:2-3:1-3.

6. The ceramic aerogel coating according to claim 1, characterized in that: The perlite is a modified perlite hollow floating bead with a mesh size of 90-120. The preparation of the modified perlite hollow floating bead comprises the following steps: Step (1), soaking, washing, filtering, and drying the hollow pearlite beads at 100-120° C. for 1-2 hours; Step (2), adding the dried hollow pearlite beads and carbon fibers to the silane coupling agent solution, stirring and mixing, and heating the mixture at 80-90° C. for 1-2 hours to obtain a mixed solution A; Step (3), adding fatty acid to the mixed solution A, mixing evenly, heating at 90-110° C. for 1-2 h, filtering, drying and sieving to obtain modified perlite hollow floating beads.

7. The ceramic aerogel coating according to claim 6, characterized in that: The mass ratio of the perlite hollow floating beads, carbon fiber and silane coupling agent is 5-8:1-3:25-35; the silane coupling agent is a 3-aminopropyl triethoxysilane ethanol solution with a mass concentration of 1-3%.

8. A method for preparing a ceramic aerogel coating according to any one of claims 1 to 7, characterized in that: The specific preparation steps include: Step Ⅰ: After cleaning the surface of the metal substrate, perform sandblasting; Step II, spray the surface of the metal substrate after sandblasting with ceramic anticorrosion primer twice, spray once, dry at 90-110°C for 1-2h, spray once again, and continue drying at 110-120°C for 1-2h to obtain a ceramic anticorrosion primer layer with a thickness of 28-32μm; Step III, add modified perlite hollow floating beads to the middle coating surface, heat to 60-80°C, stir and mix evenly, and cool naturally to obtain the middle coating base material; Step IV, continue to spray 3-5mm mid-coat primer on the surface of the ceramic anti-corrosion primer layer, control the sealing and baking temperature to 80-85°C, seal and bake for 30-40 minutes, then 100-150°C, continue to seal and bake for 2-4 hours, to obtain the mid-coat bottom layer; Step V, continue to spray 2-4 mm of the middle coating surface on the surface of the middle coating bottom layer, control the sealing and baking temperature to 80-85°C, seal and bake for 1-2 hours, then 140-160°C, continue to seal and bake for 1-2 hours, to obtain the middle coating surface layer; Step VI, grind the middle coating surface after sealing and baking twice, the first time with 360 mesh air grinder, the second time with 400 mesh sandpaper, and control the total coating thickness to 4-6mm; Step VII: spraying a transparent topcoat on the polished coating surface, and sealing and baking; Step VIII: After unified inspection, spray transparent topcoat twice and seal and bake to dry thoroughly.

9. The method for preparing a ceramic aerogel coating according to claim 8, characterized in that: The spraying method in step VII is to spray the transparent topcoat 2-4 times continuously, and bake at 80-85° C. for 3-6 hours continuously, or spray one coat of the transparent topcoat, bake at 80-85° C. for 15-60 minutes, and spray 2-4 times.

10. The method for preparing a ceramic aerogel coating according to claim 8, characterized in that: In the step VIII, water-based color paste or metal powder is added to the transparent topcoat and stirred evenly to obtain a dyed topcoat; the specific sealing and baking method in the step VIII is to seal and bake at 80-85°C for 30-40 minutes, then seal and bake at 150-160°C for 1-2 hours, or dry at room temperature for 6-12 hours, and then seal and bake at 60-80°C to thoroughly dry.

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