Organic-inorganic hybrid aerospace thermal control coating and preparation method thereof

Abstract

The invention discloses an organic-inorganic hybrid aerospace thermal control coating and a preparation method thereof, and belongs to the technical field of thermal control materials. The silicon dioxide sol is modified by benzyl organic silicon, so that the chemical composition of the inorganic silicon dioxide sol is changed, the flexibility of a molecular chain and the density of a network structure are improved, the chemical composition of the sol is effectively regulated and controlled, and the thermal expansion coefficient of the sol serving as a thermal control coating is remarkably reduced; the thermal expansion coefficient is harmoniously matched with the thermal expansion coefficient of the metal base material; meanwhile, in the aspect of filler selection and design of the thermal control coating, zinc oxide powder with different morphologies and sizes is mixed and used, and an efficient scattering network structure is constructed in the coating by virtue of unique morphological characteristics and size distribution of the zinc oxide powder; the form complementary scattering mechanism can further optimize the absorption and emission characteristics of the coating on infrared radiation, and provides powerful technical support for the application of the thermal control coating in the aerospace field.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal control materials, and in particular relates to an organic-inorganic hybrid aerospace thermal control coating and a preparation method thereof. Background Art

[0002] In the aerospace field, inorganic thermal control white coatings, compared to organic thermal control white paints, have become an indispensable key material in spacecraft and satellite thermal control systems due to their superior weathering, high-temperature resistance, and excellent resistance to atomic oxygen corrosion. However, the inherent high rigidity and low flexibility of inorganic thermal control white paints make it difficult for the coating to maintain ideal deformation under complex and changing stress environments. This weakens the bonding strength between the coating and the metal substrate, limiting the coating's service life and overall performance. In the extreme environment of space, inorganic thermal control white paint is particularly exposed to continuous irradiation of high-energy charged particles. These particles, when absorbed by the coating, are rapidly converted into high heat. The difference in thermal expansion coefficients between inorganic thermal control white paint and the metal substrate further increases the risk of deformation of the metal substrate due to thermal stress concentration under high temperature and radiation, posing a potential threat to the structural stability and thermal control effectiveness of the spacecraft.

[0003] In addition, existing thermal control coating systems often use oxide pigments with a single morphology or a single size as fillers. Oxide particles with a single morphology often lead to a single scattering pattern and cannot form a complex and efficient scattering network structure, which limits the interaction between infrared radiation and the coating material. At the same time, the distribution of particles of a single size makes it difficult to achieve fine control of the pore structure, which may lead to excessive ineffective pores or lack of necessary microcavity structure inside the coating, thereby affecting the effective absorption and emission of infrared radiation. In addition, fillers that lack morphological and size diversity often cannot fully adapt to various stress changes during the coating preparation process, which may cause defects inside the coating, thereby affecting the overall performance and stability of the coating. Summary of the Invention

[0004] The present invention aims to address, at least to some extent, one of the technical problems in the related art. To this end, the main purpose of the present invention is to provide an organic-inorganic hybrid aerospace thermal control coating that combines low solar absorptivity, high infrared emissivity, and excellent temperature resistance and resistance to atomic oxygen irradiation. This coating is of great significance for comprehensively improving the thermal control performance of spacecraft and satellite thermal control systems.

[0005] The present invention also provides a method for preparing the organic-inorganic hybrid aerospace thermal control coating.

[0006] The object of the present invention is achieved through the following technical solutions: The present invention provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, comprising the following steps: Step 1: Mixing silica sol with a certain particle size range and benzyl silicone resin in a certain proportion; Step 2: Add an appropriate amount (catalytic amount) of acidic catalyst; Step 3: Conduct a preliminary reaction at a certain temperature to ensure the mildness and controllability of the reaction. After a period of reaction, increase the temperature and continue the reaction for a certain period of time to ensure that the reaction is fully carried out; Step 4: Weigh a certain amount of zinc oxide powder with different morphologies and sizes and add it to an organic solvent. Add a silane coupling agent while stirring, and perform a modification reaction at a certain temperature for a period of time. By modifying the zinc oxide, it can be fully dispersed in the resin binder. Step 5: After the reaction is completed, the product is washed, filtered, dried, and the like to obtain modified zinc oxide powder; Step 6: Mix the modified zinc oxide powder and the benzyl silicone modified silica sol in a certain proportion and fully disperse them using a high-speed mixer to obtain color paste component A; Step 7: Add a certain amount of the color paste component A prepared in step 6 to the color paste component B and mix and stir to obtain a paint dilution solution; Step 8: Spray the coating dilution prepared in step 7 onto the surface of a metal substrate commonly used in the aerospace field, and perform thermal curing to obtain an organic-inorganic hybrid aerospace thermal control coating.

[0007] Furthermore, in step 1, the average particle size of the inorganic silica is 1 to 50 nm; the mixing mass ratio of the silica sol to the benzyl silicone resin is 1:(0.1 to 1); Furthermore, in step 2, the acidic catalyst comprises one or more of ammonium chloride, boron hexafluoride, phosphoric acid or sulfuric acid, and the mass ratio of the acidic catalyst to the silica sol is (0.001-0.1):1; Furthermore, in step 3, the temperature range for the preliminary reaction is 10-30° C., and the preliminary reaction time is 3-6 hours; the temperature range for the elevated temperature reaction is 50-80° C., and the reaction time is 1-3 hours; and the stirring rate is 200-500 rpm; Furthermore, in step 4, zinc oxide powders of different morphologies and sizes are mixed and used; wherein the morphologies of the zinc oxide powders are spherical, rod-shaped and flower-shaped, respectively, wherein the size of the spherical and rod-shaped zinc oxide powders is 15-100 nm, and the size of the flower-shaped zinc oxide powder is 3-10 μm; The mass ratio of the spherical zinc oxide powder, the rod-shaped zinc oxide powder and the flower-shaped zinc oxide powder is (0.2-1): (0.2-1): (0.5-1).

[0008] Furthermore, in step 4, the silane coupling agent includes one or more of KH550 or KH560, and the mass ratio of the silane coupling agent to the zinc oxide powder is (1-5):100; Furthermore, the process conditions of the modification reaction in step 4 are: stirring rate of 200-600 rpm, reaction temperature of 40-80° C., and reaction time of 1-5 hours; Furthermore, the washing, filtration and drying in step 5 are specifically washing with anhydrous ethanol, and the drying temperature after filtration is 40-80°C; Furthermore, in step 6, the mass ratio of the modified zinc oxide powder to the benzyl silicone modified silica sol is (0.8-4):1, the high-speed stirring speed is 1200-2000 rpm, and the dispersion time is 3-8 hours; Furthermore, in step 7, the color paste component B is diethylenetriamine or triethylenetetramine, the mass ratio of the color paste component A to the color paste component B is 100:(0.5-2), the stirring speed is 100-300 rpm, and the mixing time is 10-30 minutes; Furthermore, in step 8, the metal substrates commonly used in the aerospace field include aluminum alloys, titanium alloys, aluminum-based silicon carbide, and magnesium alloys; Furthermore, in step 8, the nozzle diameter used is 1-3 mm, the air pressure is 1-3 atm, the spraying distance is 10-30 cm, and the number of spraying times is 3-10 times; Furthermore, in step 8, the thermal curing conditions are: keeping the temperature at 80°C for 1 to 3 hours, then heating to 120°C and keeping the temperature at 120°C for 3 to 6 hours, and the coating thickness is controlled at 60 to 150 μm.

[0009] Compared with the prior art, the present invention has at least the following advantages: The preparation method of the present invention utilizes the acidic catalytic mediated benzyl silicone resin modification technology to generate new silicon-hydrogen bonds by utilizing the conversion of silicon-hydrogen bonds and the degradable alkyl migration reaction. The new silicon-hydrogen bonds undergo addition reactions with the hydroxyl / alcohol groups and other functional groups in the inorganic silica sol to construct a tightly cross-linked benzyl silicone modified silica resin structure. By modifying the silica sol with benzyl silicone, not only the chemical composition of the inorganic silica sol is changed, the flexibility of its molecular chain and the density of its network structure are improved, but also the chemical composition of the sol is effectively regulated, and the thermal expansion coefficient of the thermal control coating is significantly reduced, so that it is harmoniously matched with the thermal expansion coefficient of the metal substrate. The incorporation of the benzyl silicone resin improves the interfacial compatibility between the sol and the metal substrate, effectively alleviating the stress concentration and crack propagation problems caused by the difference in thermal expansion coefficients. While retaining the original excellent performance of the inorganic resin, the toughness of the coating of the present invention is significantly improved, making the bonding with the metal substrate more firm.

[0010] 2) The preparation method of the present invention, in terms of filler selection and design for the thermal control coating, utilizes a mixture of zinc oxide powders with varying morphologies (including spherical, rod-shaped, and flower-shaped forms) and sizes (including nanoscale and microscale). Leveraging their unique morphological characteristics and size distribution, this method constructs a highly efficient scattering network within the coating. This not only significantly enhances the interaction between infrared radiation and the coating material, effectively reducing unnecessary internal reflections, but also optimizes the pore structure, allowing infrared radiation to be more fully absorbed by the coating and converted into heat energy, which is then emitted with greater efficiency. This "morphologically complementary scattering" mechanism can further optimize the coating's absorption and emission characteristics for infrared radiation, providing strong technical support for the application of thermal control coatings in the aerospace field. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for the specific embodiments or the description of the prior art.

[0012] Figure 1 : Photograph of the organic-inorganic hybrid aerospace thermal control coating in Example 1 of the present invention; Figure 2 : Photograph of the appearance of the aerospace thermal control coating in Example 1 of the present invention after undergoing 100 cycles of a -196°C to +100°C thermal cycle test; Figure 3 : A photograph of the appearance of the aerospace thermal control coating in Example 1 of the present invention after atomic oxygen irradiation; Figure 4 : Integrating sphere reflectivity spectrum of the aerospace thermal control coating in Example 1 of the present invention in the visible light-near infrared band of 0.2-2 μm; Figure 5: Infrared reflectivity spectrum of the aerospace thermal control coating in Example 1 of the present invention in the mid-to-far infrared band of 2.5-20 μm. DETAILED DESCRIPTION

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are merely illustrative and non-restrictive, and should not be used to limit the scope of protection of the present invention.

[0014] When expressing a certain amount, concentration or other value or parameter in the form of a range, preferred range, or preferred upper and lower numerical limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper range limits or preferred numerical values ​​with any lower range limit or preferred numerical value, without considering whether the range is specifically disclosed. Unless otherwise indicated, the numerical range values ​​listed herein include the endpoints of the range and all integers and fractions within the range.

[0015] Unless otherwise indicated, all percentages, parts, ratios, etc. herein are by weight.

[0016] The materials, methods, and examples herein are illustrative and, unless otherwise indicated, are not to be construed as limiting.

[0017] In the following examples, the molecular weight of the benzyl silicone resin used is in the range of 3000-8000 g / mol, and specifically the average molecular weight is 5000 g / mol.

[0018] Example 1 This embodiment provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, which includes the following steps: Step 1: Weigh 200 g of silica sol with an average size of 20 nm and mix it with 20 g of benzyl silicone resin; Step 2: Add 1 g of acidic catalyst ammonium chloride to the mixed resin system in step 1; Step 3: Conducting a preliminary reaction at 25° C. for 3 hours at a rotation speed of 300 rpm; then raising the temperature to 60° C. and continuing the reaction at a rotation speed of 300 rpm for 2 hours to obtain a silica sol modified by a benzyl silicone resin; Step 4: Weigh 50 g of spherical zinc oxide powder with an average size of 60 nm and 50 g of flower-shaped zinc oxide powder with an average size of 5 μm, add them to anhydrous ethanol, and then add 3 g of silane coupling agent KH550; react at 50° C. for 3 hours under stirring at 300 rpm; Step 5: After the reaction is completed, wash with anhydrous ethanol, filter and dry at 60°C to obtain modified zinc oxide powder; Step 6: Weigh 100 g of modified zinc oxide powder, mix it with 80 g of benzyl silicone-modified silica sol, and disperse it at 1500 rpm for 5 hours to obtain color paste component A; Step 7: Weigh 100 g of the color paste component A in step 6, add 1 g of diethylenetriamine (color paste component B), and mix at 200 rpm for 20 minutes to obtain a paint dilution solution; Step 8: Spray the paint-free dilution prepared in step 7 onto a metal substrate; wherein the metal substrate is an aluminum alloy substrate.

[0019] During the specific spraying, the nozzle diameter of the spray gun is 1.0mm, the air pressure is 1.5atm, the spraying distance is 20cm, and the spraying is performed 5 times; then it is thermally cured at 80℃ for 2 hours, and then heated to 120℃ and thermally cured for 5 hours. The final aerospace thermal control coating prepared has a thickness of 100um.

[0020] The aerospace thermal control coating in this embodiment has a solar absorptivity of 0.133 in the 0.2-2 μm band and an infrared hemispherical emissivity of 0.940 in the 2.5-20 μm band. After exposure to atomic oxygen, the coating's solar absorptivity changed by 0.002, and its infrared hemispherical emissivity changed by 0.005. After 100 cycles of thermal cycling from -196°C to +100°C, the coating showed no signs of peeling, blistering, cracking, or shedding.

[0021] Example 2: This embodiment provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, which includes the following steps: Step 1: Weigh 200 g of silica sol with an average size of 20 nm and mix it with 50 g of benzyl silicone resin; Step 2: Add 1 g of acidic catalyst ammonium chloride to the mixed resin system in step 1; Step 3: Conducting a preliminary reaction at 25°C for 4 hours at a rotation speed of 300 rpm; then raising the temperature to 60°C and continuing the reaction at a rotation speed of 300 rpm for 3 hours to obtain a silica sol modified with benzyl silicone; Step 4: Weigh 50 g of rod-shaped zinc oxide powder with an average size of 50 nm and 50 g of flower-shaped zinc oxide powder with an average size of 5 μm, add them to anhydrous ethanol, and then add 3 g of silane coupling agent KH550; react at 50° C. for 3 hours under stirring at 300 rpm; Step 5: After the reaction is completed, wash with anhydrous ethanol, filter and dry at 60°C to obtain modified zinc oxide powder; Step 6: Weigh 100 g of modified zinc oxide powder, mix it with 100 g of benzyl silicone-modified silica sol, and disperse it at 1500 rpm for 5 hours to obtain color paste component A; Step 7: Weigh 100 g of the color paste component A in step 6, add 0.8 g of triethylenetetramine (component B) of the color paste, and mix at 200 rpm for 20 minutes to obtain a paint dilution solution; Step 8: Spray the diluted coating prepared in Step 7 onto a metal substrate. A titanium alloy substrate was selected for the metal substrate. The spray gun had a nozzle diameter of 1.0 mm, an air pressure of 1.5 atm, a spray distance of 20 cm, and four spray passes. The coating was then heat-cured at 80°C for 2 hours, then at 120°C for 5 hours. The resulting aerospace thermal control coating had a thickness of 80 μm.

[0022] The aerospace thermal control coating of this embodiment has a solar absorptivity of 0.122 in the 0.2-2 μm band and an infrared hemispherical emissivity of 0.935 in the 2.5-20 μm band. After exposure to atomic oxygen, the coating's solar absorptivity changed by 0.003, and its infrared hemispherical emissivity changed by 0.008. After 100 cycles of thermal cycling from -196°C to +100°C, the coating showed no signs of peeling, blistering, cracking, or shedding.

[0023] Example 3: This embodiment provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, which includes the following steps: Step 1: Weigh 200 g of silica sol with an average size of 10 nm and mix it with 40 g of benzyl silicone resin; Step 2: Add 1 g of acidic catalyst ammonium chloride to the mixed resin system in step 1; Step 3: Conducting a preliminary reaction at 25°C for 4 hours at a rotation speed of 300 rpm; then raising the temperature to 60°C and continuing the reaction at a rotation speed of 300 rpm for 3 hours to obtain a silica sol modified with benzyl silicone; Step 4: Weigh 25 g of spherical zinc oxide powder with an average size of 50 nm, 25 g of rod-shaped zinc oxide powder with an average size of 50 nm, and 50 g of flower-shaped zinc oxide powder with an average size of 5 μm, add them to anhydrous ethanol, and then add 3 g of silane coupling agent KH550; react at 50° C. for 3 hours under stirring at 300 rpm; Step 5: After the reaction is completed, wash with anhydrous ethanol, filter and dry at 60°C to obtain modified zinc oxide powder; Step 6: Weigh 100 g of modified zinc oxide powder, mix it with 100 g of benzyl silicone-modified silica sol, and disperse it at 1500 rpm for 5 hours to obtain color paste component A; Step 7: Weigh 100 g of the color paste component A in step 6, add 0.8 g of triethylenetetramine (component B) of the color paste, and mix at 200 rpm for 20 minutes to obtain a paint dilution solution; Step 8: Spray the diluted coating prepared in Step 7 onto a metal substrate. The metal substrate is an aluminum alloy substrate. The spray gun uses a nozzle diameter of 1.0 mm, an air pressure of 1.5 atm, a spray distance of 20 cm, and six passes. The coating is then heat-cured at 80°C for 2 hours, followed by a heat-curing at 120°C for 5 hours. The resulting aerospace thermal control coating has a thickness of 130 μm.

[0024] The aerospace thermal control coating of this embodiment has a solar absorptivity of 0.126 in the 0.2-2 μm band and an infrared hemispherical emissivity of 0.942 in the 2.5-20 μm band. After exposure to atomic oxygen, the coating's solar absorptivity changed by 0.005, and its infrared hemispherical emissivity changed by 0.002. After 100 cycles of thermal cycling from -196°C to +100°C, the coating showed no signs of peeling, blistering, cracking, or shedding.

[0025] Example 4: This embodiment provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, which includes the following steps: Step 1: Weigh 200 g of silica sol with an average size of 10 nm and mix it with 100 g of benzyl silicone resin; Step 2: Add 2 g of acidic catalyst boron hexafluoride to the mixed resin system in step 1; Step 3: Conducting a preliminary reaction at 25° C. for 4 hours at a rotation speed of 300 rpm; then raising the temperature to 80° C. and continuing the reaction at a rotation speed of 300 rpm for 3 hours to obtain a silica sol modified with benzyl silicone; Step 4: Weigh 50 g of spherical zinc oxide powder with an average size of 50 nm and 50 g of flower-shaped zinc oxide powder with an average size of 5 μm, add them to anhydrous ethanol, and then add 3 g of silane coupling agent KH550; react at 50° C. for 3 hours under stirring at 300 rpm; Step 5: After the reaction is completed, wash with anhydrous ethanol, filter and dry at 60°C to obtain modified zinc oxide powder; Step 6: Weigh 100 g of modified zinc oxide powder, mix it with 100 g of benzyl silicone-modified silica sol, and disperse it at 1500 rpm for 5 hours to obtain color paste component A; Step 7: Weigh 100 g of the color paste component A in step 6, add 0.8 g of triethylenetetramine (component B) of the color paste, and mix at 200 rpm for 20 minutes to obtain a paint dilution solution; Step 8: Spray the diluted coating prepared in Step 7 onto a metal substrate. The metal substrate selected was an aluminum-based silicon carbide substrate. The spray gun had a nozzle diameter of 1.0 mm, an air pressure of 1.5 atm, a spray distance of 20 cm, and five passes. The coating was then heat-cured at 80°C for two hours, followed by a heat-curing period of 120°C for five hours. The resulting aerospace thermal control coating had a thickness of 100 μm.

[0026] The aerospace thermal control coating of this embodiment has a solar absorptivity of 0.126 in the 0.2-2 μm band and an infrared hemispherical emissivity of 0.935 in the 2.5-20 μm band. After exposure to atomic oxygen, the coating's solar absorptivity and infrared hemispherical emissivity changed by 0.004, respectively. After 100 cycles of thermal cycling from -196°C to +100°C, the coating showed no signs of peeling, blistering, cracking, or shedding.

[0027] Example 5: This embodiment provides a method for preparing an organic-inorganic hybrid aerospace thermal control coating, which includes the following steps: Step 1: Weigh 200 g of silica sol with an average size of 10 nm and mix it with 100 g of benzyl silicone resin; Step 2: Add 2 g of acidic catalyst boron hexafluoride to the mixed resin system in step 1; Step 3: Conducting a preliminary reaction at 25° C. for 4 hours at a rotation speed of 300 rpm; then raising the temperature to 80° C. and continuing the reaction at a rotation speed of 300 rpm for 3 hours to obtain a silica sol modified with benzyl silicone; Step 4: Weigh 25 g of spherical zinc oxide powder with an average size of 50 nm, 25 g of rod-shaped zinc oxide powder with an average size of 50 nm, and 50 g of flower-shaped zinc oxide powder with an average size of 5 μm, add them to anhydrous ethanol, and then add 3 g of silane coupling agent KH550; react at 50° C. for 3 hours under stirring at 300 rpm; Step 5: After the reaction is completed, wash with anhydrous ethanol, filter and dry at 60°C to obtain modified zinc oxide powder; Step 6: Weigh 100 g of modified zinc oxide powder, mix it with 100 g of benzyl silicone-modified silica sol, and disperse it at 1500 rpm for 5 hours to obtain color paste component A; Step 7: Weigh 100 g of the color paste component A in step 6, add 0.8 g of triethylenetetramine (component B) of the color paste, and mix at 200 rpm for 20 minutes to obtain a paint dilution solution; Step 8: Spray the diluted coating prepared in Step 7 onto a metal substrate. The metal substrate selected was an aluminum-based silicon carbide substrate. The spray gun had a nozzle diameter of 1.0 mm, an air pressure of 1.5 atm, and a spray distance of 20 cm. Five passes were applied. The coating was then heat-cured at 80°C for 2 hours, followed by a heat-curing step at 120°C for 5 hours. The resulting aerospace thermal control coating had a thickness of 100 μm.

[0028] The aerospace thermal control coating of this embodiment has a solar absorptivity of 0.118 in the 0.2-2 μm band and an infrared hemispherical emissivity of 0.938 in the 2.5-20 μm band. After exposure to atomic oxygen, the coating's solar absorptivity changed by 0.007, and its infrared hemispherical emissivity changed by 0.004. After 100 cycles of thermal cycling from -196°C to +100°C, the coating showed no signs of peeling, blistering, cracking, or shedding.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for preparing an organic-inorganic hybrid aerospace thermal control coating, characterized in that: The steps include: 1) Preparation of benzyl organosilicon-modified silica sol After the silica sol and the benzyl silicone resin are uniformly mixed, a catalytic amount of an acidic catalyst is added, and a stepwise temperature addition reaction is performed to obtain the benzyl silicone modified silica sol; 2) Filler modification Zinc oxide powders of different morphologies and sizes are added to an organic solvent, and a silane coupling agent is added under stirring to carry out a modification reaction to obtain modified zinc oxide powder; 3) Preparation of thermal control coating dilution The modified zinc oxide powder and the benzyl silicone modified silica sol are mixed and dispersed evenly to obtain the color paste component A; Add the color paste component A to the aliphatic polyamine, mix and stir evenly to obtain a paint dilution solution; 4) Preparation of thermal control coating The paint dilution liquid is sprayed on the surface of a metal substrate commonly used in the aerospace field and thermally cured to obtain an organic-inorganic hybrid aerospace thermal control coating.

2. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 1, characterized in that: The particle size of the silica sol is 1-50 nm, and the acidic catalyst is one or more of ammonium chloride, boron hexafluoride, phosphoric acid or sulfuric acid.

3. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 2, characterized in that: The mass ratio of the silica sol, the benzyl silicone resin and the acid catalyst is 1:(0.1-1):(0.001-0.1).

4. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 3, characterized in that: The stepwise temperature-increasing addition reaction in step 1) is specifically as follows: at a rotation speed of 200-500 rpm, a preliminary reaction is first carried out at 10-30° C. for 3-6 hours, and then the temperature is increased to 50-80° C. for a further reaction of 1-3 hours.

5. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 1, characterized in that: The morphologies of the zinc oxide powders in step 2) are spherical, rod-shaped and flower-shaped, respectively. The sizes of the spherical and rod-shaped zinc oxide powders are 15-100 nm, and the size of the flower-shaped zinc oxide powders is 3-10 μm.

6. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 5, characterized in that: The process conditions of the modification reaction in step 2) are: a rotation speed of 200-600 rpm and a reaction temperature of 40-80° C. for 1-5 hours.

7. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 6, characterized in that: The mass ratio of the zinc oxide powder to the silane coupling agent in step 2) is 100:(1-5).

8. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 1, characterized in that: The mass ratio of the modified zinc oxide powder and the benzyl organosilicon-modified silica sol in step 3) is (0.8-4):

1.

9. The method for preparing the organic-inorganic hybrid aerospace thermal control coating according to claim 8, characterized in that: In step 3), the aliphatic polyamine is one of diethylenetriamine and triethylenetetramine or a mixture thereof, and the mass ratio of the color paste component A to the color paste component B is 100:(0.5-2).

10. An organic-inorganic hybrid aerospace thermal control coating prepared according to the preparation method according to any one of claims 1 to 9.

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