Transparent heat-insulating coating and preparation method thereof

Abstract

According to the technical scheme, the transparent heat-insulating coating and the preparation method of the transparent heat-insulating coating are provided, the transparent heat-insulating coating comprises a surface layer formed by compounding a transparent resin component and a modified nano SnO2 component, and the modified nano SnO2 component is obtained by doping antimony atoms in crystal lattices of nano SnO2 particles. As SnO2 has excellent optical performance, and the transparent heat insulation effect of SnO2 is determined by oxygen vacancies, research finds that antimony atoms can be doped into SnO2 crystal lattices in the forms of Sb < 3 + > and Sb < 5 + > to occupy the position of Sn < 4 + > to form a stable pinning effect, and an n-type semiconductor, namely a modified nano SnO2 component, is obtained. Experiments prove that the transparent heat-insulating coating formed by compounding the modified nano SnO2 component and the transparent resin component has excellent transparency and optical performance, is superior to a traditional near-infrared shielding material in the aspects of chemical stability, visible light transmittance, cost effectiveness and the like, can be used for adjusting the transmission, reflection and absorption characteristics of incident light, and can be applied to the field of near-infrared shielding materials. And the transmission and distribution of heat are effectively managed.

Description

Technical Field

[0001] The present invention relates to the technical field of optical coatings, and more specifically to a transparent heat-insulating coating and a method for preparing the transparent heat-insulating coating. Background Art

[0002] Energy consumption caused by energy exchange of architectural glass accounts for 9.45% of the total energy consumption of our society. The research and development and promotion of high-performance thermal insulation materials for energy-saving glass has become a top priority for achieving building energy conservation.

[0003] Traditional near-infrared shielding coatings generally use tin-based compound components as optical components, such as tin oxide, indium tin oxide, and fluorine-doped tin oxide. Among them, the band gap width of tin-based compounds is 3.5-4.3eV, and such a wide band gap gives them excellent optical properties. The visible light photon energy is 1.62-3.11eV. At this time, the visible light photon energy is significantly smaller than the band gap width, so the tin-based compound will not have obvious intrinsic absorption in the visible light region. It has excellent optical properties.

[0004] SnO 2 It is a tetragonal rutile structure n-type semiconductor with a 3.6-4.0eV bandgap, high electron mobility, high transmittance in the 380-780nm band, high absorption in the 780-2500nm band, high infrared shielding and high stability. Currently, as one of the most effective materials for shielding near-infrared (NIR) radiation, it has been widely used in solar filter films for automobiles and building windows to reduce energy consumption. However, SnO 2 The transparent heat-insulating effect of the coating is determined by oxygen vacancies, but the oxygen vacancy concentration itself is difficult to control. Therefore, an improved technical solution is needed to solve at least part of the above problems of the existing transparent heat-insulating coating. Summary of the invention

[0005] In view of the above-mentioned problems in the prior art, the technical solution of the present invention provides a transparent thermal insulation coating and a method for preparing the transparent thermal insulation coating, which can solve at least some of the problems existing in the transparent thermal insulation coating in the existing patents.

[0006] The present invention provides a transparent heat-insulating coating, which comprises a transparent resin component and a modified nano SnO 2 The surface layer is formed by the composite components, wherein the modified nano-SnO 2 The components are composed of nano-SnO 2 It is obtained by doping antimony atoms into the particle's crystal lattice.

[0007] According to the technical solution of the present invention, due to SnO 2 It has excellent optical properties, and its transparent heat insulation effect is determined by oxygen vacancies. 2The pure SnO is controlled by doping antimony atoms in the particle lattice. 2 The oxygen vacancy of the antimony atom was found to be Sb 3+ and Sb 5+ Formally doped into SnO 2 Lattice occupancy Sn 4+ The position of the nano-tin oxide (modified nano-SnO 2 Components). Experiments have shown that the modified nano SnO 2 The transparent thermal insulation coating formed by the composite component and the transparent resin component has excellent transparency and optical properties, and is superior to traditional near-infrared shielding materials in terms of chemical stability, visible light transmittance, cost-effectiveness, etc., and can be used to adjust the transmission, reflection and absorption characteristics of incident light, as well as effectively manage the transmission and distribution of heat.

[0008] As a preferred technical solution of the present invention, modified nano SnO 2 The components are prepared by mixing tin tetrachloride, antimony trichloride and alkaline reactants.

[0009] According to the preferred technical solution, by mixing tin tetrachloride, antimony trichloride and an alkaline reactant, antimony atoms can be doped into the lattice of tin oxide during the generation of tin oxide, thereby generating tin antimony oxide particles with more stable chemical properties.

[0010] As a preferred technical solution of the present invention, the alkaline reactants are NaOH, Na 2 CO 3 、NaHCO 3 and NH 4 HCO 3 One or more combinations of .

[0011] As a preferred technical solution of the present invention, the mass fraction ratio of tin tetrachloride to antimony trichloride is 15-20, and the mass fraction ratio of the alkaline reactant to tin tetrachloride is 2-4.

[0012] According to the preferred technical solution, the mass fraction ratio of tin tetrachloride and tin trichloride can control the modified nano SnO 2 The doping amount of antimony atoms in the component, and the antimony atoms in SnO 2 The amount of doping in the lattice can determine the modified nano-SnO 2 The carrier concentration of the components can be adjusted to adjust the performance of the coating according to the application scenario.

[0013] As a preferred technical solution of the present invention, the transparent resin component is one or more combinations of fluorosilicone resin, polycarbonate, polymethyl methacrylate, polystyrene, and acrylic resin.

[0014] As a preferred technical solution of the present invention, the transparent resin component and the modified nano SnO 2 The mole fraction ratio of the components is 2:1.

[0015] According to the preferred technical solution, the modified nano SnO 2 The molar fraction ratio of the component to the transparent resin component is 2:1, which can take into account both the strength of the coating and the optical properties of the coating, and improve the weather resistance, stability and light selectivity of the coating.

[0016] As a preferred technical solution of the present invention, the transparent heat-insulating coating further includes: an ultraviolet absorbing additive and an auxiliary additive.

[0017] According to this preferred technical solution, the ultraviolet shielding performance of the coating can be further improved by adding ultraviolet absorbing additives and auxiliary additives, thereby improving the light selectivity of the coating.

[0018] As a preferred technical solution of the present invention, the thickness of the surface layer is less than 1 mm.

[0019] According to the preferred technical solution, due to the modified nano SnO 2 The components have excellent optical properties, so a good UV shielding effect can be achieved with a thickness of less than 1 mm, which is beneficial to saving costs while avoiding excessive thickness that reduces the transmittance of the coating.

[0020] A second aspect of the present invention provides a method for preparing a transparent heat-insulating coating, comprising the following steps:

[0021] Modified Nano-SnO 2 The component preparation step is to mix tin tetrachloride, antimony trichloride and alkaline reactants to obtain modified nano SnO 2 Component precursor, modified nano SnO 2 The component precursors are dried and polished to obtain modified nano SnO 2 particle;

[0022] Preparation steps of thermal insulation coating: modified nano SnO 2 The component particles are added into a transparent resin and mixed to obtain a transparent heat-insulating coating.

[0023] As a preferred technical solution of the present invention, modified nano SnO 2 The component preparation step also includes the following sub-steps:

[0024] The precursor preparation step is to put tin tetrachloride, antimony trichloride and alkaline reactants into a polytetrafluoroethylene ball mill, add zirconium oxide balls of different sizes and mill for 0.5-3h, wash and dry to obtain modified nano SnO 2 Component precursors.

[0025] Nanoparticle preparation steps: modified nano SnO 2 The component precursors are calcined at a temperature of 400-900°C for 0.5-2h, and then kept at the same calcination temperature for more than 6h, and then cooled by ventilation and standing until room temperature, and then washed and dried to obtain modified nano SnO 2 particle.

[0026] According to the preferred technical solution, by placing tin tetrachloride, antimony trichloride and alkaline reactants into a polytetrafluoroethylene ball mill, adding zirconium oxide balls of different sizes for ball milling, the reaction can be carried out more evenly, and the particle size of the generated precursor particles can be ensured to be uniform and fine, and then calcining, heat preservation and rapid cooling can be performed to make the modified nano SnO generated in the precursor preparation step 2 The component precursors react quickly to generate modified nano-SnO 2 The particles have high preparation efficiency and are conducive to mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of a method for preparing a transparent heat-insulating coating provided in an embodiment of the present invention.

[0028] Figure 2 It is a graph showing the temperature change over time on the surface of the transparent thermal insulation coating sample provided by an embodiment of the present invention.

[0029] Figure 3 It is a schematic diagram of the surface ice coverage of the transparent thermal insulation coating sample and the control sample provided in an embodiment of the present invention at 300s. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In an embodiment of the present invention, a transparent heat-insulating coating is provided, wherein the transparent heat-insulating coating comprises a transparent resin component and a modified nano SnO 2 The surface layer is formed by the composite components.

[0032] Among them, modified nano SnO 2 The components are composed of nano-SnO 2 The particles are doped with antimony atoms. 2 It has excellent optical properties, and its transparent heat insulation effect is determined by oxygen vacancies.2 The pure SnO is controlled by doping antimony atoms in the particle lattice. 2 The oxygen vacancy of the antimony atom was found to be Sb 3+ and Sb 5+ Formally doped into SnO 2 Lattice occupancy Sn 4+ The position of the nano-tin oxide (modified nano-SnO 2 Component), the modified nano SnO 2 The transparent heat-insulating coating formed by compounding the component with the transparent resin component can have more excellent transparency and optical properties.

[0033] In some preferred embodiments, the modified nano SnO 2 The components are prepared by mixing tin tetrachloride, antimony trichloride and alkaline reactants. The mixing reaction method is not limited here. For example, tin tetrachloride and antimony trichloride can be added to a solution of an alkaline reactant, mixed and dispersed, and then heated to prepare, or solid powders can be directly mixed and ball-milled and then calcined to prepare, all of which belong to the protection scope of the present invention. By mixing tin tetrachloride, antimony trichloride and alkaline reactants, antimony atoms can be doped into the lattice of tin oxide during the generation of tin oxide, thereby generating tin antimony oxide particles with more stable chemical properties.

[0034] The alkaline reactant can be freely selected by those skilled in the art according to the requirements, and is not limited here. Preferably, the alkaline reactant can be NaOH, Na 2 CO 3 、NaHCO 3 and NH 4 HCO 3 One or more combinations of .

[0035] The inventors have found that antimony atoms in SnO 2 The amount of doping in the lattice can determine the modified nano-SnO 2 The carrier concentration of the components, that is, the transparent resin component and the modified nano-SnO 2 Therefore, in order to make the transparent heat-insulating coating have better optical properties and conductivity, the mass fraction ratio of tin tetrachloride to antimony trichloride is selected to be 15-20, and the mass fraction ratio of the alkaline reactant to tin tetrachloride is selected to be 2-4, so that the prepared modified nano SnO 2 The components can be more suitable for application scenarios of solar filter films on automobiles and building windows.

[0036] Further preferably, the transparent resin component is one or more combinations of fluorosilicone resin, polycarbonate, polymethyl methacrylate, polystyrene, acrylic resin, etc. By selecting the transparent resin component, the strength, weather resistance and transparency of the coating can be further improved. In particular, the fluorosilicone resin can be combined with the modified nano SnO 2 Strong chemical bonds can be formed between the components, thereby improving the overall chemical stability of the coating and the strength of the coating. The hydrophobicity of fluorosilicone resin inhibits the adhesion of ice crystals, making the transparent thermal insulation coating have a good anti-icing effect in some cold and humid weather.

[0037] Transparent resin component and modified nano-SnO 2 The components are compounded to form the surface layer of the transparent heat-insulating coating. When the transparent resin component is too much, the modified nano SnO 2 The distribution of components is relatively dispersed, which may affect the shielding effect of transparent thermal insulation coating on near infrared. However, if the modified nano SnO 2 Too much filling of components may affect the toughness and adhesion of the coating. Therefore, in order to obtain better coating performance, it is preferred that the transparent resin component be mixed with the modified nano-SnO 2 The molar fraction ratio of the components is selected to be 2:1, thereby improving the weather resistance, stability and light selectivity of the coating.

[0038] Wherein, preferably, the transparent heat-insulating coating may also include: ultraviolet absorbing aids and auxiliary aids. By adding ultraviolet absorbing aids and auxiliary aids to the transparent heat-insulating coating, the ultraviolet shielding performance of the coating can be further improved, and the light selectivity of the coating can be improved. Wherein, the ultraviolet absorbing aid can select one or more combinations of salicylates, benzophenones, benzotriazoles, substituted acrylonitriles and triazines, and the auxiliary aids can select quenchers, free radical scavengers, antioxidants, etc., wherein the quenchers are usually metal complexes, such as nickel complexes, which can capture excited molecules to prevent the occurrence of photooxidation reactions. Free radical scavengers can capture free radicals generated by ultraviolet irradiation and prevent the chain reactions caused by them, thereby avoiding the degradation of materials. Antioxidants can prevent or slow down the oxidation process, especially under high temperature and light conditions, they can protect the material from oxidative degradation. Those skilled in the art can also freely choose to add ultraviolet absorbing aids and auxiliary aids according to needs, without limitation here.

[0039] Due to the modified nano-SnO 2 The components have excellent optical properties, so better UV shielding effect can be achieved with a smaller thickness, which is beneficial to cost saving, while avoiding excessive thickness that reduces the transmittance of the coating. Therefore, the surface layer can be selected to be less than 1 mm thick.

[0040] In this embodiment, modified nano SnO2 The transparent thermal insulation coating formed by the composite component and the transparent resin component has excellent transparency and optical properties, and is superior to traditional near-infrared shielding materials in terms of chemical stability, visible light transmittance, cost-effectiveness, etc., and can be used to adjust the transmission, reflection and absorption characteristics of incident light, as well as effectively manage the transmission and distribution of heat.

[0041] The following experiment further demonstrates the anti-icing performance of the transparent thermal insulation coating provided by this embodiment.

[0042] 1. Material Preparation

[0043] Figure 1 FIG. 1 is a flow chart of a method for preparing a transparent heat-insulating coating according to an embodiment of the present invention. Figure 1 As shown, the preparation method of the transparent heat-insulating coating provided in this embodiment includes modifying the nano SnO 2 Component preparation step S1 and transparent heat-insulating coating preparation S2:

[0044] 1.1 Modified Nano-SnO 2 Component preparation

[0045] Modified Nano-SnO 2 Component preparation step S1, mixing tin tetrachloride, antimony trichloride and alkaline reactants to obtain modified nano SnO 2 Component precursor, modified nano SnO 2 The component precursors are dried and polished to obtain modified nano SnO 2 The method of mixing the tin tetrachloride, antimony trichloride and the alkaline reactant is not limited.

[0046] Further preferably, the modified nano SnO 2 The component preparation step S1 also includes a precursor preparation step S11 and a nanoparticle preparation step S12.

[0047] (1) Precursor preparation

[0048] In the precursor preparation step S11, tin tetrachloride, antimony trichloride and alkaline reactants are placed in a polytetrafluoroethylene ball mill, and zirconium oxide balls of different sizes are added for ball milling for 0.5-3 hours. After washing and drying, modified nano SnO 2 Component precursor. By placing tin tetrachloride, antimony trichloride and alkaline reactants into a polytetrafluoroethylene ball mill, adding zirconium oxide balls of different sizes for ball milling, the dry mixing and grinding method can make the reaction more uniform and ensure that the size of the generated precursor particles is uniform and fine, which is conducive to the subsequent reaction.

[0049] Specifically, in this embodiment, SnCl 4 ·5H2 O as a tin source precursor: weigh 35g SnCl 4 ·5H 2 O and 16-20g NaOH, 20-23g Na 2 CO 3 32-36 g NaHCO 3 、35-38gNH 4 HCO 3 In a 500 ml polytetrafluoroethylene ball mill, 1.8-2.2 g SbCl was added. 3 Weigh 5mm, 8mm and 10mm zirconium oxide balls respectively, add 5mm zirconium oxide balls, 8mm zirconium oxide balls and 10mm zirconium oxide balls in a mass ratio of 3:5:2 and a total weight of 480g into the above ball milling jar, cover and seal it in a planetary ball mill for ball milling reaction for 0.5-3h, dry and sieve after ball milling to obtain nano SnO 2 Component precursors.

[0050] (2) Nanoparticle preparation

[0051] In the nanoparticle preparation step S12, the modified nano SnO 2 The component precursors are calcined at a temperature of 400-900°C for 0.5-2h, and then kept at the same calcination temperature for more than 6h, and then cooled by ventilation and standing until room temperature, and then washed and dried to obtain modified nano SnO 2 The precursor obtained after dry mixing is more suitable for direct calcination. Through calcination, heat preservation and rapid cooling, the modified nano SnO generated in the precursor preparation step can be 2 The component precursors react quickly to generate modified nano-SnO 2 The particles have high preparation efficiency and are conducive to mass production.

[0052] Specifically, in this embodiment, the modified nano SnO prepared by ball milling 2 The component precursors are calcined in batches at 400-900°C in a muffle furnace for 0.5-2h. After calcination, a long-term heat preservation method is installed, that is, after calcination, the heat preservation treatment is carried out at the same calcination temperature for 6h, and then rapid cooling is carried out, that is, after calcination, it is immediately taken out for ventilation and cooling, and finally normal furnace cooling is carried out, that is, after sintering, it is naturally left to stand in the furnace to cool to room temperature. After the treatment is completed, it is washed and dried to obtain modified nano SnO 2 The modified nano SnO 2 The particles are uniform in size and high in purity.

[0053] 1.2 Preparation of transparent thermal insulation coating

[0054] In the thermal insulation coating preparation step S2, the modified nano SnO 2 The component particles are added to the transparent resin and mixed to obtain the transparent heat-insulating coating. Generally speaking, the transparent resin can be dissolved in a solvent, and then the modified nano-SnO 2 The component particles may preferably be added with some dispersants, UV additives or auxiliary additives as required. After adding, they are stirred evenly and then applied. The application method may be spraying, spin coating, coating, etc., which are not limited here. After application, the transparent heat-insulating coating can be obtained by curing.

[0055] Specifically, in this embodiment, the modified nano SnO 2 The particles were mixed with solvents and different dispersants in a polytetrafluoroethylene ball mill, and a certain proportion of zirconium oxide ball mill beads were added. The mixture was placed in an LGB2 planetary ball mill for ball milling modification for 3-6 hours. After the modification was completed, the modified nano SnO was obtained by filtration. 2 Then, a modified organic silicone resin with good performance, an organic ultraviolet absorber and corresponding auxiliary agents are selected to mix with the modified nano-SnO 2 The particle dispersion liquid is mixed and dispersed at high speed to obtain an ATO thermal insulation coating with good performance.

[0056] 2. Material Characterization

[0057] 2.1 UV-Vis-NIR spectroscopy analysis

[0058] Using modified nano SnO 2 The transparent heat-insulating coating obtained by compounding the particles with the transparent resin has a significant decrease in infrared transmittance in the band after 760nm, and the infrared transmittance at a single wavelength of 1400nm is only 18.8% and 15.6%, while its visible light transmittance is still 82.3% and 79.2%. It can be concluded that the transparent heat-insulating coating obtained in this embodiment can shield near-infrared light in the light while improving the light transmittance, thereby improving the shielding effect of near-infrared light without affecting the light transmittance of the glass.

[0059] 2.2 Photothermal analysis

[0060] A xenon lamp was used as a sunlight simulation system to expose the prepared transparent heat-insulating coating to one sun. After a period of irradiation, the light source was turned off and an infrared thermal imager was used to record the temperature change on the surface of the composite material during the whole process. -2)'s photothermal effect. Place the densitometer sensor under the light source in advance and adjust the current parameters to make the light intensity at 1sun. Place different samples in the same position of the polystyrene plastic box and ensure that this position is in the center of the illumination area. Turn on the thermal infrared imager and set the parameters to record a data graph every ten seconds. Turn on the light source and use a stopwatch to time and observe the temperature reading. When the equilibrium temperature is reached after a period of time, turn off the power and record the heating time at the same time. Record the cooling process at the same time interval. Ensure the same time interval when testing each transparent thermal insulation coating sample. Figure 2 FIG. 1 is a graph showing the change in surface temperature over time of the transparent heat-insulating coating sample prepared in this embodiment during the experiment. Figure 2 As shown, the temperature of the transparent thermal insulation coating sample rises to equilibrium within 600 seconds, and the temperature difference of the transparent thermal insulation coating sample with the most light absorption reaches 30°C. The thermal insulation effect of the transparent thermal insulation coating is excellent.

[0061] 2.3 Ice coverage test

[0062] The intensity of sunlight was measured in advance using a CEL-NP2000 optical power meter. A low-temperature circulation pump was connected and precooled to -25°C. The packaged perovskite cell samples were placed inside a glass chamber to avoid condensation / evaporation of water and pollutants in the air. Dry nitrogen continuously entered the homemade chamber through a gas wash bottle to maintain a constant relative humidity. Different humidity levels can be adjusted by changing the ratio of water vapor and dry nitrogen flow rates to maintain humidity at RH = 20% + 5%. The surface temperature and ambient humidity were measured using a thermocouple and a hydrometer.

[0063] In a self-made room, the -2 ) Time-resolved image of frost on the battery surface under light intensity of 1kW m-2. After adjusting the temperature and humidity in advance, the transparent thermal insulation coating sample and the control sample without transparent thermal insulation coating were placed in the glass chamber. After a period of time, a thick layer of frost formed on the surface of the transparent thermal insulation coating sample and the control sample. Then the photothermal device was turned on for a fixed time of ten minutes to take pictures of the frost on the surface of the transparent thermal insulation coating sample and the control sample. In order to obtain the numerical value of the ice coverage rate, Image J was used to analyze and process the image. The area of ​​the entire sample was regarded as 1, and the area of ​​the frosted area was calculated as the proportion of the entire sample surface. The sample coated with the transparent thermal insulation coating was compared with the control sample without the transparent thermal insulation coating. Figure 3 The surface ice coverage of the two samples at 300s is shown in Figure 3 The left side shows the sample coated with transparent heat-insulating coating. Figure 3The right side is a control sample without transparent heat-insulating coating. The frost on the surface of the transparent heat-insulating coating sample has completely melted within 256 seconds, while the control sample has not melted within 300 seconds, which proves that the transparent heat-insulating coating provided in this embodiment also has a good light-heat deicing effect.

[0064] So far, the technical solutions of the present invention have been described in conjunction with the accompanying drawings, but it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A transparent heat-insulating coating, characterized in that: The invention comprises a surface layer formed by a composite of a transparent resin component and a modified nano SnO2 component, wherein the modified nano SnO2 component is obtained by doping antimony atoms in the crystal lattice of nano SnO2 particles.

2. The transparent heat-insulating coating according to claim 1, characterized in that: The modified nano SnO2 component is prepared by mixing tin tetrachloride, antimony trichloride and alkaline reactants.

3. The transparent heat-insulating coating according to claim 2, characterized in that: The alkaline reactant is one or more combinations of NaOH, Na2CO3, NaHCO3 and NH4HCO3.

4. The transparent heat-insulating coating according to claim 3, characterized in that: The mass ratio of the tin tetrachloride to the antimony trichloride is 15-20, and the mass ratio of the alkaline reactant to the tin tetrachloride is 2-4.

5. The transparent heat-insulating coating according to claim 1, characterized in that: The transparent resin component is one or more combinations of fluorosilicone resin, polycarbonate, polymethyl methacrylate, polystyrene and acrylic resin.

6. The transparent heat-insulating coating according to claim 5, characterized in that: The molar ratio of the transparent resin component to the modified nano-SnO2 component is 2:

1.

7. The transparent heat-insulating coating according to claim 1, characterized in that: Also includes: UV absorbing additives and auxiliary additives.

8. The transparent heat-insulating coating according to claim 1, characterized in that: The thickness of the surface layer is less than 1 mm.

9. A method for preparing a transparent heat-insulating coating, characterized in that: The steps include: The modified nano SnO2 component preparation step comprises: mixing tin tetrachloride, antimony trichloride and an alkaline reactant to obtain a modified nano SnO2 component precursor, and drying and polishing the modified nano SnO2 component precursor to obtain modified nano SnO2 particles; The heat-insulating coating preparation step is to add the modified nano SnO2 component particles into the transparent resin and mix them to obtain the transparent heat-insulating coating.

10. The method for preparing the transparent heat-insulating coating according to claim 9, characterized in that: The modified nano SnO2 component preparation step also includes the following sub-steps: Precursor preparation step, putting the tin tetrachloride, antimony trichloride and alkaline reactant into a polytetrafluoroethylene ball milling tank, adding zirconium oxide balls of different sizes and milling for 0.5-3h, washing and drying to obtain the modified nano SnO2 component precursor; The nanoparticle preparation step is to calcine the modified nano-SnO2 component precursor at a temperature of 400-900°C for 0.5-2h, keep it at the same calcination temperature for more than 6h, then ventilate and cool it to room temperature, wash and dry it to obtain the modified nano-SnO2 particles.

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