An aerogel-based interior thermal insulation coating and a method for preparing the same

Abstract

The application discloses an indoor thermal insulation coating based on aerogel and a preparation method thereof, and belongs to the technical field of coating preparation, and is used for solving the technical problem that the adhesion and corrosion resistance of the indoor thermal insulation coating in the prior art need to be further improved; the application constructs a multi-component system of composite aerogel powder, phosphorus-containing silane bonding resin and fluorinated corrosion-resistant resin, so that the microporous structure, interface bonding and chemical stability are simultaneously optimized in the same coating, wherein the composite aerogel powder provides a stable porous heat-conducting barrier structure, the phosphorus-containing silane bonding resin improves the bonding density of the coating between the substrate and the inorganic phase, and the fluorinated corrosion-resistant resin endows the coating with the structural retention ability under alkaline and humid heat conditions; through the synergistic regulation of the material structure and the interface, the coating is significantly improved in terms of thermal insulation, wear resistance, adhesion and alkali corrosion resistance.

Description

Technical Field

[0001] This invention relates to the field of coating preparation technology, specifically to an aerogel-based indoor thermal insulation coating and its preparation method. Background Technology

[0002] In existing research on indoor thermal insulation coatings, adhesion and corrosion resistance remain key performance characteristics. As thermal insulation systems develop towards lightweight and porous structures, the bonding methods between organic resins and inorganic substrates within the coating are constantly evolving from simple physical adsorption to achieving stable connections through various means such as polarity adjustment, silane modification, and the construction of interfacial transition layers. This is to meet the long-term bonding requirements under conditions of humidity, thermal cycling, and mechanical stress. At the same time, factors such as moisture, cleaning agents, and alkaline mortar residues in the indoor environment can cause chemical corrosion to the coating. Therefore, existing technologies generally employ methods such as reducing resin water absorption, introducing hydrophobic segments, increasing coating density, and constructing anti-permeability barriers to maintain the structural integrity of the coating under alkaline and humid conditions. Overall, the stabilization of the adhesion interface and the construction of a structure resistant to media corrosion are gradually becoming the main directions for the development of indoor thermal insulation coating technology.

[0003] Existing indoor thermal insulation coatings still have certain limitations in long-term use. As the system tends to be lightweight and porous, the interface between the coating and the substrate is prone to problems such as unstable adhesion and decreased adhesion under thermal cycling, humid and hot conditions, and continuous stress. The insufficient density of the interface transition layer formed by the porous structure also causes local softening of the coating after water vapor penetration, affecting its mechanical retention ability. At the same time, corrosion protection mostly relies on the hydrophobicity of the resin or a single barrier structure. In alkaline media, cleaning agents, and repeated humid environments, early failures such as whitening, blistering, or softening may still occur. Some formulations have limited structural retention ability under long-term alkaline immersion conditions and are difficult to maintain a stable state over a long exposure period. In addition, the insufficient functional distribution and compatibility between multi-component systems also make it difficult to achieve both thermal insulation performance and media resistance performance, affecting the overall performance of the coating.

[0004] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an aerogel-based indoor thermal insulation coating and its preparation method, which solves the technical problem that the adhesion and corrosion resistance of existing indoor thermal insulation coatings need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solutions: An aerogel-based indoor thermal insulation coating comprises the following raw materials in parts by weight: 40-60 parts composite aerogel powder, 20-35 parts phosphorus-containing silane binding resin, 10-15 parts fluorinated corrosion-resistant resin, 80-100 parts dispersant, 1-2 parts leveling agent and 1-2 parts defoamer. Furthermore, the dispersant is obtained by mixing deionized water and anhydrous ethanol at a ratio of 2-3 mL: 1 mL and adjusting the pH to 7-8; the leveling agent is polyether-modified polysiloxane; and the defoamer is one or both of polydimethylsiloxane and polypropylene glycol. Furthermore, the preparation method of the composite aerogel powder includes the following steps: A1. Add porous silica-oxygen gel powder, anhydrous ethanol and deionized water to a reaction vessel and stir. Adjust the pH of the system to 4-5 with glacial acetic acid, then add 3-(2,3-epoxypropoxy)propyltrimethoxysilane to the reaction vessel and keep the temperature of the reaction vessel at 20-30℃. Stir for 2-3 hours and then process to obtain epoxy-modified aerogel powder. A2. Epoxy-modified aerogel powder, 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, trimethylolpropane triacrylate, 1H,1H,2H,2H-perfluorodecyl acrylate, azobisisobutyronitrile and N,N-dimethylformamide are added to a reaction vessel. After thorough stirring, nitrogen gas is introduced for protection, and the reaction vessel is heated to 70-80℃ and stirred for 3-5 hours. The composite aerogel powder is then obtained through post-treatment.

[0007] The reaction principle for preparing composite aerogel powder is as follows: By introducing 3-(2,3-epoxypropoxy)propyltrimethoxysilane under weak acid conditions, the silanol generated after hydrolysis can condense with the hydroxyl groups on the surface of porous silica-oxygen gel to form stable Si-O-Si bonds, thereby grafting epoxy-containing organic functional groups onto the surface of the inorganic framework, providing reaction sites for subsequent reactions. Subsequently, under the action of an initiator, the epoxy-modified surface, along with phosphorus-containing flame-retardant units, acrylic trifunctional crosslinking agents, and fluorinated hydrophobic monomers, participate in free radical polymerization. The resulting crosslinked organic network is fixed on the surface of the silica-oxygen framework through chemical bonds or strong interfacial interactions, giving the material a flame-retardant structure, hydrophobic segments, and a three-dimensional crosslinked layer. Through the synergistic construction of multiple functional materials, composite aerogel powder is finally prepared.

[0008] Furthermore, the ratio of porous silica-oxygen gel powder, anhydrous ethanol, deionized water, and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 10-20 g: 400 mL: 100-200 mL: 20-30 mL. Post-treatment includes: after the reaction is complete, the reaction solution is filtered to collect the filter cake. The filter cake is washed 3-5 times with anhydrous ethanol and deionized water. The filter cake is then transferred to a drying oven at 60°C and vacuum dried to constant weight. It is then milled and sieved to obtain D. 50 Epoxy-modified aerogel powder with a diameter of 8-10 μm; Further, in step A2, the ratio of epoxy-modified aerogel powder, 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, trimethylolpropane triacrylate, 1H,1H,2H,2H-perfluorodecyl acrylate, azobisisobutyronitrile, and N,N-dimethylformamide is 10g:2-3g:2-4g:1-2g:0.1-0.2g:100-120mL. Post-treatment includes: after the reaction is complete, wait for the reactor temperature to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3-5 times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 60℃ and vacuum dry to constant weight, then grind and sieve to obtain D. 50 Composite aerogel powder with a diameter of 10-12 μm.

[0009] Furthermore, the preparation method of the porous silica-oxygen gel powder is as follows: tetraethoxysilane, methyltrimethoxysilane, anhydrous ethanol and deionized water are added to a reaction vessel, the pH of the reaction system is adjusted to 9-10 using saturated ammonia water and the temperature of the reaction vessel is maintained at 20-30℃, the mixture is stirred at this temperature for 1-2 hours, and then allowed to stand for aging for 12-16 hours. The porous silica-oxygen gel powder is then obtained through post-treatment.

[0010] The reaction principle for preparing porous silica-oxygen gel powder is as follows: In an alcohol-water system, tetraethoxysilane and methyltrimethoxysilane first undergo hydrolysis of the ethoxy and methoxy groups under alkaline conditions to generate intermediates with active silanol groups. Subsequently, these silanols gradually construct a three-dimensional cross-linked Si-O-Si inorganic network structure through siloxane bond condensation. The participation of methylsilane can introduce organic side groups into the network, making the resulting framework more hydrophobic and improving structural stability. As the hydrolysis and condensation reactions continue, the system gradually transforms from a sol into a wet gel with a spatially continuous framework and nanoscale pores. The pores of this gel mainly originate from phase separation and structural solidification during the self-assembly process of the siloxane network. After subsequent solvent replacement and drying, the solvent is removed from the channels while the framework structure is retained, thus forming a lightweight, porous, and high specific surface area porous silica-oxygen gel powder.

[0011] Furthermore, in the preparation of porous silica-oxygen gel powder, the ratio of tetraethoxysilane, methyltrimethoxysilane, anhydrous ethanol, and deionized water is 10-12 mL:4 mL:40-50 mL:10 mL. Post-treatment includes: after static aging, cutting the wet gel into blocks and immersing them in anhydrous ethanol 3-5 times, each time for 4-6 hours. After immersion, the blocks are dried in a drying oven at 40-60℃ until constant weight, then ground and sieved to obtain D. 50 Porous silica-oxygen gel powder with a diameter of 5-8 μm.

[0012] Furthermore, the preparation method of the phosphorus-containing silane bonding resin includes the following steps: B1. Add ε-caprolactone, trimethylolpropane and stannous octoate to a reaction vessel, stir under nitrogen protection, raise the temperature of the reaction vessel to 110-130℃, keep it at the temperature and stir for 4-6 hours, and then cool it to room temperature to obtain polycaprolactone polyol. B2. Polycaprolactone polyol, ethyl acetate, anhydrous ethanol, triethylamine and phosphorus oxychloride are added to a reaction vessel. The reaction vessel is cooled to 0-10℃ and stirred for 1-2 hours. Then the reaction vessel is heated to 40-50℃ and stirred for 1 hour. Isophorone diisocyanate and 3-aminopropyltriethoxysilane are added to the reaction vessel in sequence. The reaction vessel is heated to 60-70℃ and stirred for 3-5 hours. The post-treatment yields a phosphorus-containing silane bonding resin.

[0013] The reaction principle for preparing phosphorus-containing silane bonding resin is as follows: First, stannous octoate catalyzes the ring-opening polymerization of ε-caprolactone and trimethylolpropane to form a polycaprolactone polyol with multiple hydroxyl end groups, providing reaction sites for the subsequent introduction of phosphorus, aminosilane, and isocyanate. Subsequently, in the presence of basic amine, phosphorus oxychloride undergoes esterification and substitution reactions with the hydroxyl groups of the polyol, converting some hydroxyl groups into phosphate ester structures, thereby endowing the system with a stable phosphorus-containing skeleton. Further, isophorone diisocyanate undergoes addition reactions with the residual hydroxyl groups to construct flexible polyurethane segments. In the later stage of the reaction, it further reacts with the amino and silanol alkyl groups of 3-aminopropyltriethoxysilane, allowing the organic polyurethane structure to be simultaneously grafted with silane groups. The resulting silane groups can undergo hydrolysis and condensation during subsequent curing or use to form a stable Si-O-Si network, realizing an organic-inorganic composite of phosphate ester structure, polyurethane segments, and silane crosslinking points, thereby constructing a phosphorus-containing silane adhesive resin with adhesiveness, heat resistance, and flame retardancy.

[0014] Furthermore, in step B1, the ratio of ε-caprolactone, trimethylolpropane, and stannous octanoate is 50-60 mL: 5 g: 0.08 mL. Further, in step B2, the ratio of polycaprolactone polyol, ethyl acetate, anhydrous ethanol, triethylamine, phosphorus oxychloride, isophorone diisocyanate, and 3-aminopropyltriethoxysilane is 8-10g:15-20mL:5-10mL:1.2mL:0.6mL:3mL:1-2mL. The post-treatment includes: after the reaction is completed, removing part of the organic solvent under reduced pressure at 40-50℃ until the viscosity is 2000-2400mPa·s, and then cooling to room temperature to obtain a phosphorus-containing silane bonding resin.

[0015] Furthermore, the preparation method of the fluorinated corrosion-resistant resin includes the following steps: C1. 2,5-furandicarboxylic acid, polyethylene glycol 400, p-toluenesulfonic acid and xylene are added to a reaction vessel, the reaction vessel is heated to reflux and water is separated for 4-6 hours, and then the furan polyester is obtained after post-treatment. C2. Add furan polyester and N,N-dimethylformamide to a reaction vessel and stir. After the solid has completely dissolved, add N,N'-(4,4'-methylenediphenyl)bismaleimide and heat the reaction vessel to 80-100℃. Keep the temperature and stir for 2-4 hours. Then, cool the reaction vessel to 60-70℃ and add 1H,1H,2H,2H-perfluorodecyl isocyanate to the reaction vessel. Continue to keep the temperature and stir for 2-3 hours. The post-treatment yields a fluorinated corrosion-resistant resin.

[0016] The reaction principle for preparing fluorinated corrosion-resistant resins is as follows: First, 2,5-furandicarboxylic acid and polyethylene glycol undergo esterification and polycondensation under acid catalysis to form a polyester with a furan ring structure in the main chain, thereby providing flexible segments. Further, the perfluorodecyl isocyanate introduced into the system undergoes isocyanate addition reaction with the hydroxyl groups in the polyester, grafting hydrophobic perfluoroalkyl structures onto the segments, giving the resin low surface energy and anti-fouling properties. Through the synergistic construction of flexible polyester segments and fluorinated hydrophobic end groups, a fluorinated corrosion-resistant resin is finally prepared.

[0017] Further, in step C1, the ratio of 2,5-furandicarboxylic acid, polyethylene glycol 400, p-toluenesulfonic acid, and xylene is 10-12g:18mL:0.1-0.3g:10-15mL. The post-processing includes: after the reaction is completed, vacuum distillation is carried out until no liquid is collected, and the reaction vessel is cooled to room temperature to obtain furan polyester. Further, in step C2, the ratio of furan polyester, N,N-dimethylformamide, N,N'-(4,4'-methylenediphenyl)bismaleimide and 1H,1H,2H,2H-perfluorodecyl isocyanate is 10g:30mL:20-30g:10-15mL. The post-treatment includes: after the reaction is completed, the temperature of the reaction vessel is reduced to room temperature, and the system is distilled under reduced pressure until the solid content of the system is 65-70%, to obtain fluorinated corrosion-resistant resin.

[0018] This invention also discloses a method for preparing an indoor thermal insulation coating based on aerogel, comprising the following steps: adding a dispersant, composite aerogel powder and phosphorus-containing silane binding resin into a dispersion vessel, stirring for 40-60 minutes, then adding a fluorinated corrosion-resistant resin, a defoamer and a leveling agent, and continuing to stir for 20-30 minutes to obtain the indoor thermal insulation coating.

[0019] The reaction principle for preparing indoor thermal insulation coatings is as follows: The composite aerogel powder has a highly porous silica-oxygen network. The numerous nanopores inside can effectively inhibit heat convection and conduction, making it the core heat insulation unit of the coating. At the same time, the phosphorus-containing silane binder resin enhances the interfacial bonding with the aerogel surface through the hydrolysis and condensation of silane and the polar effect of the phosphate ester structure during dispersion, so that the coating forms a continuous and stable inorganic-organic composite skeleton, thereby improving the structural strength and flame retardancy of the coating film. The fluoroalkyl segments of the subsequently added fluorinated corrosion-resistant resin endow the coating film with low surface energy properties, making it hydrophobic, antifouling and aging resistant, and finally preparing an indoor thermal insulation coating.

[0020] The present invention has the following beneficial effects: 1. The composite aerogel powder prepared by this invention has a three-dimensional porous Si-O-Si framework structure and extremely low solid thermal conductivity, which can effectively block the transfer of heat in the coating and is the main functional component for reducing the thermal conductivity. The phosphorus-containing silane binding resin forms a stable silane interface layer on the surface of the composite aerogel powder, so that the aerogel is uniformly dispersed in the coating and tightly bonded to the resin matrix, thereby avoiding local thermal bridges caused by particle agglomeration. At the same time, its cross-linking structure improves the density of the coating and extends the heat transfer path. Meanwhile, the fluorinated corrosion-resistant resin gives the system low moisture absorption and good environmental stability, so that the pore structure of the composite aerogel powder remains intact under humid and hot conditions, avoiding the increase in thermal conductivity caused by water absorption. Finally, through the synergistic effect of the three materials in terms of structural construction, interface bonding and humid and hot stability, the coating of this invention forms a continuous and stable low thermal conductivity composite network, thereby achieving a thermal insulation effect superior to traditional thermal insulation coatings.

[0021] 2. The phosphorus-containing silane bonding resin prepared by this invention can hydrolyze and condense on the substrate surface to form stable Si-O-base bonds, giving the coating excellent chemical bonding strength. At the same time, the cross-linking structure of the resin enhances the overall strength and density of the coating film, effectively inhibiting interfacial peeling during wear. The uniform dispersion of composite aerogel powder in the coating film can form a multi-point support structure, effectively dispersing frictional loads and reducing local stress concentration, thereby improving the coating's resistance to repeated wear. Meanwhile, the fluorinated corrosion-resistant resin has high surface hardness and low surface energy, which can reduce adhesive wear during friction and prevent the interface from weakening under environmental conditions by improving the coating's hygrothermal stability. Finally, through the synergistic effect of multiple components in mechanical reinforcement, interfacial bonding, and surface stability, the coating has both high wear resistance and high adhesion, and its overall performance is significantly better than that of conventional indoor coatings.

[0022] 3. The fluorinated corrosion-resistant resin prepared by this invention has excellent chemical stability and low polarity structure. Its molecular chain has high resistance to strong alkaline environments and can form a stable protective interface on the coating surface, avoiding degradation of the resin matrix by alkaline solutions. The composite aerogel powder has a stable Si-O-Si inorganic network structure and high chemical inertness to alkaline media. It can form a stable inorganic skeleton inside the coating, reducing the erosion of the coating depth by alkaline solutions. At the same time, the silane groups in the phosphorus-containing silane bonding resin form a dense cross-linked network during the curing process and generate stable Si-O- bonds with the substrate surface, which can effectively block the penetration of alkaline media and reduce the risk of interface hydrolysis and powdering. The synergistic effect of the three in terms of inorganic stability, interface densification and surface chemical resistance makes the coating form a continuous and corrosion-resistant composite barrier structure, so that it can still maintain integrity and adhesion under strong alkaline conditions, significantly improving the overall alkali corrosion resistance. Detailed Implementation

[0023] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] In this application, polyethylene glycol 400 was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with the product number S30185; xylene was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with the product number X112051; polyether-modified polysiloxane was purchased from Zhejiang Zhenghe Silicon Materials Co., Ltd., with the product number PB98334; and polypropylene glycol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with the product number P103209.

[0025] Example 1 This embodiment provides a method for preparing composite aerogel powder, including the following steps: Step ①: Preparation of porous silica-oxygen gel powder Weigh out 30.0 mL of tetraethoxysilane, 12.0 mL of methyltrimethoxysilane, 120.0 mL of anhydrous ethanol, and 30.0 mL of deionized water and add them to the reaction vessel. Adjust the pH of the reaction system to 9 using saturated ammonia water and maintain the reaction vessel temperature at 20°C. After stirring at this temperature for 1 hour, allow it to stand for aging for 12 hours. After aging is complete, cut the wet gel into pieces and soak them in anhydrous ethanol three times, each time for 4 hours. After soaking, place the pieces in a drying oven at 40°C and dry to constant weight. Grind and sieve to obtain D. 50 Porous silica-oxygen gel powder with a diameter of 5 μm.

[0026] Step 2: Preparation of epoxy-modified aerogel powder Weigh out 10.0 g of porous silica-oxygen gel powder, 400.0 mL of anhydrous ethanol, and 100.0 mL of deionized water and add them to a reaction vessel. Stir the mixture and adjust the pH of the system to 4 using glacial acetic acid. Then, add 20.0 mL of 3-(2,3-epoxypropoxy)propyltrimethoxysilane to the reaction vessel and maintain the temperature at 20°C. Stir for 2 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the filter cake three times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 60°C and vacuum dry it to constant weight. Grind and sieve the product to obtain D. 50 Epoxy-modified aerogel powder with a diameter of 8 μm.

[0027] Step 3: Preparation of composite aerogel powder Weigh out 10.0g of epoxy-modified aerogel powder, 2.0g of 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, 2.0g of trimethylolpropane triacrylate, 1.0g of 1H,1H,2H,2H-perfluorodecyl acrylate, 0.1g of azobisisobutyronitrile, and 100.0mL of N,N-dimethylformamide and add them to a reaction vessel. After thorough stirring, purge with nitrogen for protection and heat the reaction vessel to 70℃. Maintain this temperature and stir for 3 hours. After the reaction is complete, allow the reaction vessel temperature to drop to room temperature, filter the reaction solution, collect the filter cake, wash the filter cake three times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 60℃ and vacuum dry to constant weight. Grind and sieve to obtain D. 50 Composite aerogel powder with a diameter of 10 μm.

[0028] Example 2 This embodiment provides a method for preparing composite aerogel powder, including the following steps: Step ①: Preparation of porous silica-oxygen gel powder Weigh out 36.0 mL of tetraethoxysilane, 12.0 mL of methyltrimethoxysilane, 150.0 mL of anhydrous ethanol, and 30.0 mL of deionized water and add them to the reaction vessel. Adjust the pH of the reaction system to 10 using saturated ammonia water and maintain the reaction vessel temperature at 30°C. After stirring at this temperature for 2 hours, allow it to stand for 16 hours. After standing aging is complete, cut the wet gel into pieces and soak them in anhydrous ethanol five times, each time for 6 hours. After soaking, place the pieces in a drying oven at 60°C and dry them to constant weight. Grind and sieve to obtain D. 50 Porous silica-oxygen gel powder with a diameter of 8 μm.

[0029] Step 2: Preparation of epoxy-modified aerogel powder Weigh out 20.0 g of porous silica-oxygen gel powder, 400.0 mL of anhydrous ethanol, and 200.0 mL of deionized water and add them to a reaction vessel. Stir the mixture and adjust the pH of the system to 5 using glacial acetic acid. Then, add 30.0 mL of 3-(2,3-epoxypropoxy)propyltrimethoxysilane to the reaction vessel and maintain the temperature at 30°C. Stir for 3 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the filter cake five times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 60°C and vacuum dry it to constant weight. Grind and sieve the product to obtain D. 50 Epoxy-modified aerogel powder with a diameter of 10 μm.

[0030] Step 3: Preparation of composite aerogel powder Weigh out 10.0g of epoxy-modified aerogel powder, 3.0g of 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, 4.0g of trimethylolpropane triacrylate, 2.0g of 1H,1H,2H,2H-perfluorodecyl acrylate, 0.2g of azobisisobutyronitrile, and 120.0mL of N,N-dimethylformamide and add them to a reaction vessel. After thorough stirring, purge with nitrogen for protection and heat the reaction vessel to 80℃. Maintain this temperature and stir for 5 hours. After the reaction is complete, allow the reaction vessel temperature to drop to room temperature, filter the reaction solution, collect the filter cake, wash the filter cake five times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 60℃, vacuum dry to constant weight, grind and sieve to obtain D. 50 Composite aerogel powder with a diameter of 12 μm.

[0031] Example 3 This embodiment provides a method for preparing composite aerogel powder, including the following steps: Step ①: Preparation of porous silica-oxygen gel powder Weigh out 36.0 mL of tetraethoxysilane, 12.0 mL of methyltrimethoxysilane, 135.0 mL of anhydrous ethanol, and 30.0 mL of deionized water and add them to the reaction vessel. Adjust the pH of the reaction system to 10 using saturated ammonia water and maintain the reaction vessel temperature at 25°C. After stirring at this temperature for 2 hours, allow it to stand for aging for 15 hours. After aging is complete, cut the wet gel into pieces and soak them in anhydrous ethanol four times, each time for 5 hours. After soaking, place the pieces in a drying oven at 50°C and dry to constant weight. Grind and sieve to obtain D. 50 Porous silica-oxygen gel powder with a diameter of 6 μm.

[0032] Step 2: Preparation of epoxy-modified aerogel powder Weigh out 160.0 g of porous silica-oxygen gel powder, 400.0 mL of anhydrous ethanol, and 150.0 mL of deionized water and add them to a reaction vessel. Stir the mixture and adjust the pH of the system to 4 using glacial acetic acid. Then, add 25.0 mL of 3-(2,3-epoxypropoxy)propyltrimethoxysilane to the reaction vessel and maintain the temperature at 25°C. Stir for 3 hours. After the reaction is complete, filter the reaction solution and collect the filter cake. Wash the filter cake four times with anhydrous ethanol and deionized water. Transfer the filter cake to a drying oven at 60°C and vacuum dry it to constant weight. Grind and sieve the product to obtain D. 50 Epoxy-modified aerogel powder with a diameter of 9 μm.

[0033] Step 3: Preparation of composite aerogel powder Weigh out 10.0g of epoxy-modified aerogel powder, 2.5g of 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, 3.0g of trimethylolpropane triacrylate, 1.6g of 1H,1H,2H,2H-perfluorodecyl acrylate, 0.2g of azobisisobutyronitrile, and 120.0mL of N,N-dimethylformamide and add them to a reaction vessel. After thorough stirring, purge with nitrogen for protection and heat the reaction vessel to 75℃. Maintain this temperature and stir for 4 hours. After the reaction is complete, allow the reaction vessel temperature to drop to room temperature, filter the reaction solution, collect the filter cake, wash the filter cake four times with anhydrous ethanol and deionized water, transfer the filter cake to a drying oven at 60℃, vacuum dry to constant weight, grind and sieve to obtain D. 50 Composite aerogel powder with a diameter of 11 μm.

[0034] Example 4 This embodiment provides a method for preparing a phosphorus-containing silane bonding resin, including the following steps: Step I: Preparation of polycaprolactone polyol Weigh out 50.0 mL of ε-caprolactone, 5.0 g of trimethylolpropane and 0.08 mL of stannous octoate and add them to the reaction vessel. Stir under nitrogen protection and raise the temperature of the reaction vessel to 110 °C. Keep stirring at this temperature for 4 h and then cool to room temperature to obtain polycaprolactone polyol.

[0035] Step II: Preparation of phosphorus-silane-containing bonding resin Weigh out 8.0 g of polycaprolactone polyol, 15.0 mL of ethyl acetate, 5.0 mL of anhydrous ethanol, 1.2 mL of triethylamine, and 0.6 mL of phosphorus oxychloride and add them to a reaction vessel. Cool the reaction vessel to 0°C and stir for 1 h, then heat the reaction vessel to 40°C and stir for 1 h. Then add 3.0 mL of isophorone diisocyanate and 1.0 mL of 3-aminopropyltriethoxysilane to the reaction vessel in sequence, and heat the reaction vessel to 60°C and stir for 3 h. After the reaction is complete, remove part of the organic solvent under reduced pressure at 40°C until the viscosity is 2000 mPa·s, and then cool to room temperature to obtain a phosphorus-containing silane bonding resin.

[0036] Example 5 This embodiment provides a method for preparing a phosphorus-containing silane bonding resin, including the following steps: Step I: Preparation of polycaprolactone polyol Weigh out 60.0 mL of ε-caprolactone, 5.0 g of trimethylolpropane and 0.08 mL of stannous octoate and add them to the reaction vessel. Stir under nitrogen protection and raise the temperature of the reaction vessel to 130 °C. Keep stirring at this temperature for 6 h and then cool to room temperature to obtain polycaprolactone polyol.

[0037] Step II: Preparation of phosphorus-silane-containing bonding resin Weigh out 10.0 g of polycaprolactone polyol, 20.0 mL of ethyl acetate, 10.0 mL of anhydrous ethanol, 1.2 mL of triethylamine, and 0.6 mL of phosphorus oxychloride and add them to a reaction vessel. Cool the reaction vessel to 10 °C and stir for 2 h. Then heat the reaction vessel to 50 °C and stir for 1 h. Add 3.0 mL of isophorone diisocyanate and 2.0 mL of 3-aminopropyltriethoxysilane to the reaction vessel in sequence. Heat the reaction vessel to 70 °C and stir for 5 h. After the reaction is complete, remove part of the organic solvent under reduced pressure at 50 °C until the viscosity is 2400 mPa·s. Cool to room temperature to obtain phosphorus-containing silane bonding resin.

[0038] Example 6 This embodiment provides a method for preparing a phosphorus-containing silane bonding resin, including the following steps: Step I: Preparation of polycaprolactone polyol Weigh out 54.0 mL of ε-caprolactone, 5.0 g of trimethylolpropane and 0.08 mL of stannous octoate and add them to the reaction vessel. Stir under nitrogen protection and raise the temperature of the reaction vessel to 120 °C. Keep stirring at this temperature for 5 h and then cool to room temperature to obtain polycaprolactone polyol.

[0039] Step II: Preparation of phosphorus-silane-containing bonding resin Weigh out 9.0 g of polycaprolactone polyol, 18.0 mL of ethyl acetate, 8.0 mL of anhydrous ethanol, 1.2 mL of triethylamine, and 0.6 mL of phosphorus oxychloride and add them to a reaction vessel. Cool the reaction vessel to 5 °C and stir for 2 h, then heat the reaction vessel to 45 °C and stir for 1 h. Then add 3.0 mL of isophorone diisocyanate and 1.5 mL of 3-aminopropyltriethoxysilane to the reaction vessel in sequence, and heat the reaction vessel to 65 °C and stir for 4 h. After the reaction is complete, remove part of the organic solvent under reduced pressure at 45 °C until the viscosity is 2100 mPa·s, and then cool to room temperature to obtain a phosphorus-containing silane bonding resin.

[0040] Example 7 This embodiment provides a method for preparing a fluorinated corrosion-resistant resin, including the following steps: Step (1): Preparation of furan polyester Weigh out 10.0g of 2,5-furandicarboxylic acid, 18.0mL of polyethylene glycol 400, 0.1g of p-toluenesulfonic acid and 10.0mL of xylene and add them to the reaction vessel. Heat the reaction vessel to reflux and separate the water for 4 hours. After the reaction is completed, distill under reduced pressure until no liquid is collected. Cool the reaction vessel to room temperature to obtain furan polyester.

[0041] Step 2: Preparation of fluorinated corrosion-resistant resin Weigh 10.0 g of furan polyester and 30.0 mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the solid is completely dissolved. Then add 20.0 g of N,N'-(4,4'-methylenediphenyl)bismaleimide and heat the reaction vessel to 80°C. Keep it heated and stirred for 2 hours. Then cool the reaction vessel to 60°C and add 10.0 mL of 1H,1H,2H,2H-perfluorodecyl isocyanate. Continue to keep it heated and stirred for 2 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and then distill under reduced pressure until the solid content of the system is 65% to obtain the fluorinated corrosion-resistant resin.

[0042] Example 8 This embodiment provides a method for preparing a fluorinated corrosion-resistant resin, including the following steps: Step (1): Preparation of furan polyester Weigh out 12.0g of 2,5-furandicarboxylic acid, 18.0mL of polyethylene glycol 400, 0.3g of p-toluenesulfonic acid and 15.0mL of xylene and add them to the reaction vessel. Heat the reaction vessel to reflux and separate the water for 6 hours. After the reaction is completed, distill under reduced pressure until no liquid is collected. Cool the reaction vessel to room temperature to obtain furan polyester.

[0043] Step 2: Preparation of fluorinated corrosion-resistant resin Weigh out 10.0 g of furan polyester and 30.0 mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the solid is completely dissolved. Then add 30.0 g of N,N'-(4,4'-methylenediphenyl)bismaleimide and heat the reaction vessel to 100°C. Keep the temperature and stir for 4 h. Then cool the reaction vessel to 70°C and add 15.0 mL of 1H,1H,2H,2H-perfluorodecyl isocyanate. Continue to keep the temperature and stir for 3 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and then distill under reduced pressure until the solid content of the system is 70% to obtain fluorinated corrosion-resistant resin.

[0044] Example 9 This embodiment provides a method for preparing a fluorinated corrosion-resistant resin, including the following steps: Step (1): Preparation of furan polyester Weigh out 12.0g of 2,5-furandicarboxylic acid, 18.0mL of polyethylene glycol 400, 0.2g of p-toluenesulfonic acid, and 12.0mL of xylene and add them to the reaction vessel. Heat the reaction vessel to reflux and separate the water for 5 hours. After the reaction is complete, distill under reduced pressure until no liquid is collected. Cool the reaction vessel to room temperature to obtain furan polyester.

[0045] Step 2: Preparation of fluorinated corrosion-resistant resin Weigh out 10.0 g of furan polyester and 30.0 mL of N,N-dimethylformamide and add them to the reaction vessel. Stir until the solid is completely dissolved. Then add 25.0 g of N,N'-(4,4'-methylenediphenyl)bismaleimide and heat the reaction vessel to 90 °C. Keep it heated and stirred for 3 h. Then cool the reaction vessel to 65 °C and add 12.0 mL of 1H,1H,2H,2H-perfluorodecyl isocyanate. Continue to keep it heated and stirred for 3 h. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and then distill it under reduced pressure until the solid content of the system is 68% to obtain the fluorinated corrosion-resistant resin.

[0046] Example 10 This embodiment provides a method for preparing an aerogel-based indoor thermal insulation coating, including the following steps: Weigh out 200.0 mL of deionized water and 100.0 mL of anhydrous ethanol, mix them, and adjust the pH to 7 to obtain the dispersant; Weigh out 40 parts by weight of the composite aerogel powder prepared in Example 1, 20 parts by weight of the phosphorus-containing silane bonding resin prepared in Example 4, and 80 parts by weight of the dispersant and add them to the dispersion vessel. After stirring for 40 minutes, add 10 parts by weight of the fluorinated corrosion-resistant resin prepared in Example 7, 1 part by weight of the polyether-modified polysiloxane, and 1 part by weight of the polypropylene glycol. Continue stirring for 20 minutes to obtain the indoor thermal insulation coating.

[0047] Example 11 This embodiment provides a method for preparing an aerogel-based indoor thermal insulation coating, including the following steps: Weigh out 300.0 mL of deionized water and 100.0 mL of anhydrous ethanol, mix them, and adjust the pH to 8 to obtain the dispersant; Weigh out 60 parts by weight of the composite aerogel powder prepared in Example 2, 35 parts by weight of the phosphorus-containing silane bonding resin prepared in Example 5, and 100 parts by weight of the dispersant and add them to the dispersion vessel. After stirring for 60 minutes, add 15 parts by weight of the fluorinated corrosion-resistant resin prepared in Example 9, 2 parts by weight of the polyether-modified polysiloxane and 2 parts by weight of the polypropylene glycol, and continue stirring for 30 minutes to obtain the indoor thermal insulation coating.

[0048] Example 12 This embodiment provides a method for preparing an aerogel-based indoor thermal insulation coating, including the following steps: Weigh out 250.0 mL of deionized water and 100.0 mL of anhydrous ethanol, mix them, and adjust the pH to 8 to obtain the dispersant; Weigh out 50 parts by weight of the composite aerogel powder prepared in Example 3, 35 parts by weight of the phosphorus-containing silane bonding resin prepared in Example 6, and 90 parts by weight of the dispersant and add them to the dispersion vessel. After stirring for 50 minutes, add 12 parts by weight of the fluorinated corrosion-resistant resin prepared in Example 9, 2 parts by weight of the polyether-modified polysiloxane and 2 parts by weight of the polypropylene glycol, and continue stirring for 25 minutes to obtain the indoor thermal insulation coating.

[0049] Comparative Example 1 The difference between this comparative example and Example 12 is that the composite aerogel powder used in this example omits the use of 1H,1H,2H,2H-perfluorodecyl acrylate in step ③ of the preparation process.

[0050] Comparative Example 2 The difference between this comparative example and Example 12 is that the phosphorus-containing silane bonding resin used in this example omits the use of 3-aminopropyltriethoxysilane in step II of the preparation process.

[0051] Comparative Example 3 The difference between this comparative example and Example 12 is that the fluorinated corrosion-resistant resin used in this example omits the use of 1H,1H,2H,2H-perfluorodecyl isocyanate in step II of the preparation process.

[0052] Performance testing: The wall surface is dusted, degreased, and repaired to ensure a smooth and clean surface, with the moisture content controlled to <10%. Then, under conditions of 20℃ and 60% relative humidity, a primer is applied evenly using a roller, with a coating amount of approximately 100g / m². 2After the primer has dried naturally until it is surface dry, the indoor thermal insulation coatings prepared in Examples 10-12 and Comparative Examples 1-3 are applied in two coats, with each coat having a wet film thickness of 0.4 mm and a 2-hour interval between coats. The coating amount is 80 g / m². 2 After construction, maintain good ventilation and allow it to cure for 5 days to obtain a functional coating; The thermal insulation performance of the functional coatings obtained after curing of the indoor thermal insulation coatings prepared in Examples 10-12 and Comparative Examples 1-3 was determined in accordance with the standard T / CIE 082-2020 "Test Method for Thermal Insulation Temperature Difference of Thermal Insulation Coatings". The abrasion resistance of the functional coatings obtained after curing of the indoor thermal insulation coatings prepared in Examples 10-12 and Comparative Examples 1-3 was determined in accordance with the standard GB / T 1768-2006 "Determination of Abrasion Resistance of Paints and Varnishes - Rotary Rubber Grinding Wheel Method". The adhesion properties of the functional coatings obtained after curing of the indoor thermal insulation coatings prepared in Examples 10-12 and Comparative Examples 1-3 were determined in accordance with the standard GB / T 1720-2020 "Cross-cut Test of Coating Film". The corrosion resistance of the functional coatings obtained after curing of the indoor thermal insulation coatings prepared in Examples 10-12 and Comparative Examples 1-3 was determined in accordance with the standard GB / T 9755-2024 "Synthetic Resin Emulsion Wall Coatings". See Table 1 for specific data; Table 1 - Performance Test Data for Each Sample

[0053] Data Analysis: Comparative analysis of the data in Table 1 reveals that the temperature difference between the inside and outside of the wall surface after curing the functional coating obtained by applying the indoor thermal insulation coating prepared in this invention is 11.3℃, and the mass loss is 6mg·1000r. -1 The adhesion grade was 1, and no abnormalities were observed after treatment with 3% sodium hydroxide aqueous solution for 72 hours. All data were superior to the comparative example. This indicates that: In Comparative Example 1, step ③ did not construct a fluorinated organic shell layer on the surface of the epoxy-modified aerogel powder, resulting in the composite aerogel powder retaining only a polar-affinity inorganic framework and a small amount of organic groups. This resulted in a high surface energy, making it prone to interaction with water and alkaline media. During the service of the coating, the pores of this type of powder are prone to moisture absorption and expansion or structural rearrangement, leading to local pore collapse. This destroys the original continuous porous network, shortens the heat transfer path, increases the thermal conductivity, and reduces the heat preservation effect. At the same time, the interfacial compatibility between the powder and the organic resin is insufficient. Under repeated friction and alkaline immersion conditions, the interfacial voids become stress concentration sources, easily generating microcracks that extend into the coating. This manifests as increased coating peeling and accelerated alkaline media penetration during the wear process, ultimately leading to a simultaneous decrease in wear resistance and alkali corrosion resistance. In Comparative Example 2, step II did not introduce a silane structure that could condense with the inorganic phase and substrate into the resin molecule. As a result, the interface between the phosphorus-containing adhesive resin and the inorganic wall and composite aerogel powder relied solely on physical adsorption and limited polarity, lacking stable chemical bond connections. After the coating cured, the continuity and density of the interface layer were significantly insufficient. Under temperature and humidity fluctuations and external forces, microscopic debonding and voids were easily generated, leading to a reduction in the stiffness and load-bearing capacity of the adhesion interface. During the wear process, these interface defects rapidly expanded into macroscopic peeling under shear stress, resulting in a decrease in wear resistance. Under alkaline media corrosion conditions, the interface voids provided a rapid penetration channel for the alkali solution, causing blistering, powdering, and adhesion decay near the substrate, thereby weakening the overall coating's resistance to alkali corrosion and long-term adhesion stability. In Comparative Example 3, step (2) did not introduce fluorinated segments into the furan polyester / maleimide backbone, resulting in a higher surface polarity and increased water absorption tendency of the obtained resin. In alkaline and humid environments, it is more prone to swelling and segment relaxation. During long-term service of the coating, the water absorption swelling and drying shrinkage of the resin phase alternate, causing the internal residual stress to accumulate continuously. Fatigue damage occurs at the interface, and the adhesion gradually decreases. Under the action of abrasion, the mechanical strength and hardness of the swollen resin phase decrease, making it difficult to form an effective coating and support for the composite aerogel powder. The abraded surface is more easily torn and peeled off. At the same time, the resin phase's shielding ability against alkaline media is weakened. Alkali can penetrate into the coating through resin microcracks and interface channels, accelerating substrate corrosion and interface failure, thus causing a significant decrease in alkali corrosion resistance. In conclusion, the functional coating obtained by this invention relies on the multiple roles of composite aerogel powder, phosphorus-containing silane binder resin, and fluorinated corrosion-resistant resin in structural construction, interface regulation, and chemical stability. This enables the coating to exhibit stable, balanced, and highly consistent performance output in multiple key properties. Specifically, the composite aerogel powder forms a continuous and stable microporous network in the coating, effectively extending the heat conduction path; the phosphorus-containing silane binder resin forms a dense interface between the substrate, inorganic phase, and organic phase, allowing the coating to maintain its intact structure under external force, humid heat, and chemical media conditions; and the fluorinated corrosion-resistant resin endows the coating with the ability to maintain its structure in strongly alkaline environments. This allows the coating to maintain long-term stable performance in application scenarios such as wear resistance, adhesion, and alkali corrosion resistance. The three types of materials in the system respectively undertake different functions of pore structure stability, interface bonding, and protective barrier, enabling the coating to achieve comprehensive effects in thermal, mechanical, and chemical properties that are difficult to achieve with a single component, demonstrating excellent application applicability and performance completeness.

[0054] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An aerogel-based indoor thermal insulation coating, characterized in that, The raw materials consist of the following parts by weight: 40-60 parts composite aerogel powder, 20-35 parts phosphorus-containing silane bonding resin, 10-15 parts fluorinated corrosion-resistant resin, 80-100 parts dispersant, 1-2 parts leveling agent and 1-2 parts defoamer. The preparation method of the composite aerogel powder includes the following steps: A1. Add porous silica-oxygen gel powder, anhydrous ethanol and deionized water to a reaction vessel and stir. Adjust the pH of the system to 4-5 with glacial acetic acid, then add 3-(2,3-epoxypropoxy)propyltrimethoxysilane to the reaction vessel and keep the temperature of the reaction vessel at 20-30℃. Stir for 2-3 hours and then process to obtain epoxy-modified aerogel powder. A2. Epoxy-modified aerogel powder, 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, trimethylolpropane triacrylate, 1H,1H,2H,2H-perfluorodecyl acrylate, azobisisobutyronitrile and N,N-dimethylformamide are added to a reaction vessel. After thorough stirring, nitrogen gas is introduced for protection, and the reaction vessel is heated to 70-80℃ and kept at this temperature for 3-5 hours. The composite aerogel powder is then obtained through post-treatment. The method for preparing the porous silica-oxygen gel powder is as follows: tetraethoxysilane, methyltrimethoxysilane, anhydrous ethanol and deionized water are added to a reaction vessel, the pH of the reaction system is adjusted to 9-10 using saturated ammonia water and the temperature of the reaction vessel is maintained at 20-30℃. After stirring at this temperature for 1-2 hours, the mixture is allowed to stand for aging for 12-16 hours, and then post-processed to obtain the porous silica-oxygen gel powder. The preparation method of the phosphorus-containing silane bonding resin includes the following steps: B1. Add ε-caprolactone, trimethylolpropane and stannous octoate to a reaction vessel, stir under nitrogen protection, raise the temperature of the reaction vessel to 110-130℃, keep it at the temperature and stir for 4-6 hours, and then cool it to room temperature to obtain polycaprolactone polyol. B2. Polycaprolactone polyol, ethyl acetate, anhydrous ethanol, triethylamine and phosphorus oxychloride are added to a reaction vessel. The reaction vessel is cooled to 0-10℃ and stirred for 1-2 hours. Then the reaction vessel is heated to 40-50℃ and stirred for 1 hour. Isophorone diisocyanate and 3-aminopropyltriethoxysilane are added to the reaction vessel in sequence. The reaction vessel is heated to 60-70℃ and stirred for 3-5 hours. The post-treatment yields a phosphorus-containing silane bonding resin. The preparation method of the fluorinated corrosion-resistant resin includes the following steps: C1. 2,5-furandicarboxylic acid, polyethylene glycol 400, p-toluenesulfonic acid and xylene are added to a reaction vessel, the reaction vessel is heated to reflux and water is separated for 4-6 hours, and then the furan polyester is obtained by post-treatment. C2. Add furan polyester and N,N-dimethylformamide to a reaction vessel and stir. After the solid has completely dissolved, add N,N'-(4,4'-methylenediphenyl)bismaleimide and heat the reaction vessel to 80-100℃. Keep the temperature and stir for 2-4 hours. Then, cool the reaction vessel to 60-70℃ and add 1H,1H,2H,2H-perfluorodecyl isocyanate to the reaction vessel. Continue to keep the temperature and stir for 2-3 hours. The post-treatment yields a fluorinated corrosion-resistant resin.

2. The aerogel-based indoor thermal insulation coating according to claim 1, characterized in that, In step A1, the ratio of porous silica-oxygen gel powder, anhydrous ethanol, deionized water and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 10-20g:400mL:100-200mL:20-30mL.

3. The aerogel-based indoor thermal insulation coating according to claim 1, characterized in that, In step A2, the ratio of epoxy-modified aerogel powder, 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide, trimethylolpropane triacrylate, 1H,1H,2H,2H-perfluorodecyl acrylate, azobisisobutyronitrile and N,N-dimethylformamide is 10g:2-3g:2-4g:1-2g:0.1-0.2g:100-120mL.

4. The aerogel-based indoor thermal insulation coating according to claim 1, characterized in that, In the process of preparing porous silica-oxygen gel powder, the ratio of tetraethoxysilane, methyltrimethoxysilane, anhydrous ethanol and deionized water is 10-12 mL:4 mL:40-50 mL:10 mL.

5. The aerogel-based indoor thermal insulation coating according to claim 1, characterized in that, In step B1, the ratio of ε-caprolactone, trimethylolpropane, and stannous octoate is 50-60 mL: 5 g: 0.08 mL; in step B2, the ratio of polycaprolactone polyol, ethyl acetate, anhydrous ethanol, triethylamine, phosphorus oxychloride, isophorone diisocyanate, and 3-aminopropyltriethoxysilane is 8-10 g: 15-20 mL: 5-10 mL: 1.2 mL: 0.6 mL: 3 mL: 1-2 mL.

6. The aerogel-based indoor thermal insulation coating according to claim 1, characterized in that, In step C1, the ratio of 2,5-furandicarboxylic acid, polyethylene glycol 400, p-toluenesulfonic acid, and xylene is 10-12g:18mL:0.1-0.3g:10-15mL; in step C2, the ratio of furan polyester, N,N-dimethylformamide, N,N'-(4,4'-methylenediphenyl)bismaleimide, and 1H,1H,2H,2H-perfluorodecyl isocyanate is 10g:30mL:20-30g:10-15mL.

7. A method for preparing an aerogel-based indoor thermal insulation coating as described in any one of claims 1-6, characterized in that, The preparation method of the aerogel-based indoor thermal insulation coating includes the following steps: adding dispersant, composite aerogel powder and phosphorus-containing silane binding resin into a dispersion vessel, stirring for 40-60 minutes, adding fluorinated corrosion-resistant resin, defoamer and leveling agent, and continuing to stir for 20-30 minutes to obtain the indoor thermal insulation coating.

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