High-weather-resistance electroless refrigeration coating, preparation method and application thereof

Abstract

This invention discloses a highly weather-resistant, non-electric cooling coating, its preparation method, and its applications. The coating comprises, by weight, 50-70 parts of silane-modified lithium silicate inorganic resin, 15-30 parts of barium sulfate, 5-10 parts of spherical glass microspheres, 3-6 parts of flake boron nitride, 2-5 parts of silane coupling agent, 1-3 parts of sodium fluoroborate, and additives. This invention utilizes spherical glass microspheres and flake boron nitride to construct a micro-nano composite rough surface, synergistically enhancing solar reflectance and infrared radiation; employs barium sulfate of three particle sizes to achieve full-spectrum scattering; and utilizes sodium fluoroborate to promote dense cross-linking of the inorganic network. The coating exhibits a solar reflectance >95%, a mid-infrared emissivity >94%, and excellent weather resistance, making it suitable for passive cooling in various fields such as construction, industry, and transportation, requiring no energy input.

Description

Technical Field

[0001] This invention belongs to the field of functional coatings and non-electric refrigeration technology, specifically relating to a high weather-resistant non-electric refrigeration coating based on silane-modified lithium silicate inorganic resin, its preparation method, and its application in construction, industry, transportation, and other fields. Background Technology

[0002] Against the backdrop of increasingly severe global energy consumption and climate change issues, the cooling needs of the building and industrial sectors constitute a huge energy burden. Traditional compressor-based air conditioning systems are not only energy-intensive, but the refrigerants they use also pose a potential threat to the environment. Therefore, the development of passive radiative cooling technology, which requires no external energy input, has become a focus of attention for the global scientific and industrial communities. Passive radiative cooling technology is a new type of cooling technology with zero energy consumption and zero emissions. It achieves cooling by simultaneously achieving high solar reflectivity (reflecting sunlight in the 0.3-2.5μm wavelength band back into space) and high-to-medium infrared thermal emissivity (radiating heat from the Earth's surface to the low-temperature outer space through an 8-13μm atmospheric window). In recent years, this technology has shown great potential in areas such as building energy conservation, industrial cooling, and outdoor equipment protection.

[0003] Existing non-electro-cooling coatings are mainly divided into two categories: one is solvent-based or water-based coatings based on organic resins, such as acrylic, polyurethane, and fluorocarbon resins. Although these can achieve high optical performance, organic base materials are susceptible to corrosion from ultraviolet light, high temperature, humidity, and acid rain under long-term outdoor exposure, leading to yellowing, chalking, decreased adhesion, and generally insufficient weather resistance, with an outdoor lifespan of less than 5 years. The other category is inorganic coatings, such as silicates and silica sols. Although they have excellent weather resistance, they suffer from poor film density, low flexibility, easy cracking, poor water resistance, and weak adhesion to the substrate, making them difficult to use directly as high-performance radiation-cooling coatings.

[0004] Existing cooling coatings still have the following shortcomings: (1) Insufficient optical performance: Most existing non-electric cooling coatings have a solar reflectance and mid-infrared emissivity of less than 95%. For example, the reflectance of TiO2 / PDMS coating is only 88.2% and the emissivity is 92.4%, which cannot meet the requirements of high-efficiency cooling. (2) Poor environmental adaptability: Under specific environmental conditions such as high humidity, existing coatings cannot achieve sub-environmental temperature cooling effect. For example, the daytime temperature difference in some areas is only 7.9℃, which seriously affects the actual application effect. (3) Insufficient weather resistance: Most existing technologies use organic resin matrix. When exposed to ultraviolet rays, temperature and humidity changes and other environmental conditions for a long time, the coating is prone to aging and peeling, resulting in a short service life. (4) High cost and limited applicability: Early research mostly used precious metal materials. Although the optical performance is excellent, the cost is high, making it difficult to apply on a large scale. Traditional coatings are mostly designed for specific substrates and cannot be widely used in various scenarios such as construction, industry, and transportation.

[0005] Therefore, developing an electro-cooling coating that combines high solar reflectivity (>95%), high and medium infrared emissivity (>95%), and ultra-long outdoor weather resistance (>10 years) is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0006] This invention aims to solve the problems of insufficient solar reflectivity, inadequate mid-infrared emissivity, and poor weather resistance in existing non-electric cooling coatings. It provides a non-electric cooling coating prepared using silane-modified lithium silicate inorganic resin, achieving a solar reflectivity >95% and a mid-infrared emissivity >95%. It can achieve significant non-electric cooling effects without external energy or refrigerant and has excellent weather resistance. It can be widely used in many fields such as building cooling, industrial energy conservation, logistics and transportation, new energy, and material storage.

[0007] This invention provides a highly weather-resistant, non-electric cooling coating, comprising the following components by weight: 50-70 parts of silane-modified lithium silicate inorganic resin, 15-30 parts of barium sulfate, 5-10 parts of spherical glass microspheres, 3-6 parts of flake boron nitride, 2-5 parts of silane coupling agent, 1-3 parts of sodium fluoroborate, 0.5-1 part of dispersant, 0.3-0.8 parts of leveling agent, 1-5 parts of defoamer, 2-8 parts of thickener, and 15-60 parts of deionized water.

[0008] As a preferred embodiment of the present invention, the barium sulfate is composed of three particles with different particle size ranges, and based on the total weight of the barium sulfate: barium sulfate with a particle size of 0.1-0.3 μm accounts for 20-30%, barium sulfate with a particle size of 1.0-2.5 μm accounts for 35-40%, and barium sulfate with a particle size of 4.0-10 μm accounts for 35-40%.

[0009] As a preferred embodiment of the present invention, the spherical glass microspheres have a diameter of 20-50 μm; the sheet-like boron nitride has a sheet diameter of 1-8 μm and a thickness of 1-20 nm.

[0010] As a preferred embodiment of the present invention, the silane coupling agent is one or more combinations of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0011] As a preferred embodiment of the present invention, the dispersant is at least one of ammonium polycarboxylate and sodium polycarboxylate.

[0012] As a preferred embodiment of the present invention, the defoamer is selected from one or more of mineral oil defoamers, fluorosiloxane defoamers, organosilicon defoamers, silicone-free defoamers, and polymeric defoamers.

[0013] As a preferred embodiment of the present invention, the thickener is one or more of cellulose thickener, polyurethane thickener, and polyacrylic acid thickener.

[0014] As a preferred embodiment of the present invention, the leveling agent is one or more of polyether-modified polydimethylsiloxane leveling agent, polyacrylate leveling agent, and fluorocarbon-modified polyacrylate leveling agent.

[0015] The silane-modified lithium silicate inorganic resin is prepared using the raw materials and method described in patent number 202210281702.6, the entire contents of which are incorporated herein by reference. This silane-modified lithium silicate inorganic resin comprises the following raw materials in parts by weight: 30-60 parts lithium silicate solution, 1-5 parts 3-ureapropyltriethoxysilane, 10-30 parts lithium hydroxide solution, 5-20 parts γ-aminopropyltriethoxysilane, and 5-20 parts methyltriethoxysilane.

[0016] Preferably, the concentration of the lithium silicate solution is 20-25%, and the modulus is 4-10. The concentration of the lithium hydroxide solution is 5-15%.

[0017] Preferably, the above-mentioned method for preparing lithium silicate-based inorganic resin includes the following steps: (1) adding lithium silicate solution into a constant temperature device and stirring; (2) adding 3-ureapropyltriethoxysilane and then adding lithium hydroxide solution to adjust the pH to 11-12.5; (3) continuing to add γ-aminopropyltriethoxysilane and then adding methyltriethoxysilane, stirring and reacting, and cooling to obtain the lithium silicate-based inorganic resin.

[0018] This invention provides a method for preparing a highly weather-resistant, non-electro-cooling coating, comprising the following steps:

[0019] (1) Mix deionized water, dispersant, and 30-70wt% defoamer evenly, add barium sulfate, spherical glass microspheres, and flake boron nitride, and disperse at high speed to obtain slurry;

[0020] (2) Add silane-modified lithium silicate inorganic resin, silane coupling agent, and sodium fluoroborate to the slurry and stir until uniform;

[0021] (3) Add leveling agent, thickener and remaining defoamer, stir evenly, filter and discharge to obtain the final product.

[0022] As a preferred embodiment of the present invention, the high-speed dispersion in step (1) is performed at a rotation speed of 500-2500 r / min for 15-45 minutes.

[0023] This invention also provides the application of highly weather-resistant, non-electric cooling coatings in building cooling, industrial energy conservation, logistics and transportation, new energy, and material storage.

[0024] This invention constructs a synergistic microscopic three-dimensional radiation structure by combining spherical glass microspheres with sheet-like boron nitride, achieving an ultra-high infrared emissivity exceeding 95%. The spherical glass microspheres, primarily composed of silicon dioxide, utilize the phonon resonance of their Si-O bonds to provide strong infrared emission, while their spherical shape enhances solar reflection. The sheet-like boron nitride imparts high emissivity. The combination of the two forms an uneven, rough three-dimensional surface, significantly increasing the effective radiation area. This combination of spherical and sheet-like structures increases the radiation surface, achieving a solar reflectivity >94% and significantly improving radiative cooling efficiency.

[0025] According to Mie scattering theory, the energy of the solar spectrum is mainly distributed in the 0.3-2.5 μm range. The scattering efficiency of reflective fillers is closely related to the ratio of particle size to light wavelength. This invention utilizes 0.1-0.3 μm nano-sized barium sulfate for efficient scattering of ultraviolet and short-wave visible light, 1.0-2.5 μm submicron-sized barium sulfate for efficient scattering of visible light and short-wave near-infrared light, and 4.0-10 μm micron-sized barium sulfate for efficient scattering of mid-to-long-wave near-infrared light. This "multi-modal" particle size distribution ensures extremely high broadband reflectance across the entire solar spectrum from ultraviolet to near-infrared, avoiding the reflectance limitations of single-size fillers in certain wavelength bands. The multi-graded filler also increases packing density, reduces light transmission, and increases the optical path length in the coating thickness direction, thereby increasing the total reflectance through multiple reflections. The solar reflectance of this combined formulation can stably reach over 96%, far exceeding that of single-size barium sulfate or traditional TiO2-based coatings.

[0026] The inorganic lithium silicate system (Si-O-Si, Si-O-Li bonds) selected in this invention possesses natural UV resistance, oxidation resistance, and high-temperature resistance compared to traditional organic resins, laying a solid foundation for the long-term weather resistance of the coating. The silane-modified lithium silicate inorganic resin can cure at room temperature to form -Si-O-Si- chemical crosslinking bonds, creating a dense three-dimensional inorganic network. This crosslinking network exhibits high chemical stability, strong UV resistance, and excellent water resistance and salt spray corrosion resistance, enabling the coating to maintain effective all-weather cooling for a long period. Compared to traditional polymer coatings, the inorganic lithium silicate system fundamentally avoids the degradation problem of organic components under UV irradiation. This invention also introduces sodium fluoroborate as a film-forming promoter. Sodium fluoroborate decomposes into fluoride ions and borate ions during the coating film-forming process, which is beneficial for promoting the crosslinking and densification of the -Si-O-Si- network in the silane-modified lithium silicate resin, while simultaneously regulating curing shrinkage stress and reducing microcracks. The denser coating not only improves UV reflectivity but also reduces the penetration paths of moisture and corrosive media, thus enhancing both the optical stability and weather resistance of the coating. Furthermore, the denser surface further increases specular reflection contribution, contributing to an overall improvement in reflectivity.

[0027] In addition, silane coupling agents improve filler dispersibility and compatibility, prevent sedimentation and agglomeration, ensure uniform and stable optical performance, and enhance the mechanical strength and adhesion of the coating.

[0028] The advantages or beneficial effects of the high weather-resistant, electro-cooling coating provided by this invention include at least the following:

[0029] (1) By using a combination of three barium sulfate particles with specific sizes, efficient reflection of the entire solar spectrum (300-2500nm) is achieved; (2) Through the synergistic effect of spherical glass microspheres and sheet-like boron nitride, a microscopic three-dimensional structure with multi-directional reflection and efficient infrared radiation is constructed; (3) Silane-modified lithium silicate inorganic resin is used as the base material, and sodium fluoroborate is introduced as a film-forming promoter, giving the coating excellent weather resistance and density. The coating prepared by this invention has a solar reflectivity >96% and a mid-infrared emissivity >94%, and can achieve a significant passive cooling effect without external energy. It can be widely used in many energy-saving and cooling fields such as building roofs, storage tanks, refrigerated trucks, and data centers. Detailed Implementation

[0030] To more clearly illustrate the purpose, technical solution, and advantages of this invention, the technical solution of this invention will be described in detail below through specific embodiments. It should be noted that these embodiments are only for illustrating this invention and not for limiting its scope of protection; the actual scope of protection of this invention should be determined by the claims.

[0031] Unless otherwise specified, the materials and reagents used in the following examples and comparative examples are commercially available. Unless otherwise specified, the amount of each component in the following examples is 1 g per part by weight.

[0032] I. Source of raw materials used in the examples:

[0033] 1. Silane-modified lithium silicate inorganic resin: Prepared according to Example 1 of patent CN202210281702.6 (lithium silicate solution modulus 6, concentration 22%; lithium hydroxide concentration 10%; reaction pH=11; raw materials by weight: 50 parts lithium silicate solution, 3 parts 3-ureapropyltriethoxysilane, 20 parts lithium hydroxide solution, 12 parts γ-aminopropyltriethoxysilane, 12 parts methyltriethoxysilane). Raw materials used: lithium silicate solution (modulus 8, solid content 22%), purchased from Zhejiang Tongtai Chemical Co., Ltd.; 3-ureapropyltriethoxysilane (A-Link 1524), γ-aminopropyltriethoxysilane (A-1100), methyltriethoxysilane (A-1630), and lithium hydroxide were all commercially available.

[0034] 2. Barium sulfate (BaSO4): Purchased from Foshan Bozhen Chemical Co., Ltd., and prepared in various particle sizes. Specifically: particle size 0.1-0.3 μm, average particle size D50 = 0.25 μm; particle size 1.0-2.5 μm, average particle size D50 = 1.5 μm; particle size 4.0-10 μm, average particle size D50 = 4.5 μm.

[0035] 3. Spherical glass microspheres: Model K25, with a diameter of approximately 40μm, purchased from 3M Company, USA.

[0036] 4. Boron nitride, XFBN05, 5μm diameter, 5nm thickness, purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.

[0037] 5. γ-aminopropyltriethoxysilane, sodium fluoroborate, ammonium polycarboxylate dispersant, polyether-modified polydimethylsiloxane leveling agent, mineral oil defoamer, and polyurethane thickener are all industrial grade and commercially available.

[0038] 6. Acrylic emulsion (for comparative example): Pure acrylic emulsion, model Primal AC-261, purchased from Dow Chemical Company, USA.

[0039] 7. Deionized water: prepared in the laboratory, conductivity <1 μS / cm.

[0040] II. Preparation Methods of Coatings

[0041] A method for preparing a highly weather-resistant, non-electric cooling coating includes the following steps:

[0042] (1) Mix deionized water, dispersant and 50% defoamer evenly, add barium sulfate, spherical glass microspheres and flake boron nitride, and disperse and stir at 1000 r / min for 30 min to obtain slurry;

[0043] (2) Add silane-modified lithium silicate inorganic resin, silane coupling agent, and sodium fluoroborate to the slurry and stir for 15 min;

[0044] (3) Add leveling agent, thickener and the remaining 50% defoamer, stir for 20 minutes, filter and discharge to obtain the final product.

[0045] The embodiments and comparative examples of the present invention were prepared using the above preparation method according to the weight parts shown in Table 1 below.

[0046] Table 1: Component formulations of the examples (unit: parts by weight)

[0047]

[0048] Table 2: Component formulations for comparative examples (unit: parts by weight)

[0049]

[0050] Comparative Example 7

[0051] The difference from Example 1 is that the lithium silicate was not modified, and an equal amount of lithium silicate was used to replace the silane-modified lithium silicate inorganic resin. Other conditions were the same as in Example 1.

[0052] Comparative Example 8

[0053] The difference from Example 1 is that an equal amount of acrylic emulsion is used instead of silane-modified lithium silicate inorganic resin, while other conditions are the same as in Example 1.

[0054] III. Performance Testing

[0055] 1. Solar reflectivity: Measured according to ASTM G173-03 standard, reflectivity in the 250-2500nm wavelength band.

[0056] 2. Mid-infrared emissivity: The average emissivity of the atmospheric window of 8-13 μm was measured using a Fourier transform infrared spectrometer (FTIR).

[0057] 3. Weather resistance test: QUV accelerated aging (UVA-340 lamp, irradiance 0.89W / m²@340nm, 60℃ light exposure for 4h, 50℃ condensation for 4h cycle), and the solar reflectance retention rate was tested after 1000h.

[0058] 4. Cooling and cooling test: An outdoor test chamber was set up, and the aluminum plate was coated with paint. The difference between the ambient temperature and the air temperature inside the chamber was compared (12:00-14:00 noon, with an average of 38℃). The test was performed 6 times and the average value was taken.

[0059] Table 3: Test Results

[0060]

[0061] According to the test results in Table 3, the high weather-resistant, non-electric cooling coatings prepared in Examples 1-6 exhibit excellent comprehensive performance, with a solar reflectivity of 95.0%-96.5%, a mid-infrared emissivity of 94.3%-96.1%, and a reflectivity retention rate of 96.8%-97.5% after 1000h QUV accelerated aging, achieving a passive cooling effect of 9.3-10.1℃. This performance advantage stems from the synergistic mechanism of barium sulfate with multiple particle sizes, spherical glass microspheres, sheet-like boron nitride, sodium fluoroborate, and silane-modified lithium silicate inorganic resin: the three specific barium sulfate particle sizes achieve full-spectrum efficient scattering in the ultraviolet-visible and near-infrared bands, respectively; the spherical glass microspheres and sheet-like boron nitride construct a micro-nano composite rough surface, synergistically enhancing solar reflection and infrared radiation; sodium fluoroborate catalyzes dense cross-linking of the -Si-O-Si- network, improving the coating's weather resistance; and the silane-modified lithium silicate inorganic resin provides a three-dimensional inorganic framework that resists ultraviolet radiation and aging, achieving a balance between high reflectivity, high radiation, and high weather resistance.

[0062] Comparative Example 1 used only 0.1-0.3 μm barium sulfate, Comparative Example 2 used only 1.0-2.5 μm barium sulfate, and Comparative Example 3 used only 4.0-10 μm barium sulfate. Compared with Example 1, the solar reflectance of the three examples decreased by 11.4%, 13.3%, and 12.6%, respectively. After 1000 h QUV, the reflectance retention rate decreased by 7.4%, 7.9%, and 7.7%, respectively, and the temperature difference decreased by 4.0℃, 4.4℃, and 4.2℃, respectively. The core reason is that the combination of three barium sulfate particle sizes is the key to achieving full-spectrum reflectance: small-sized barium sulfate efficiently reflects ultraviolet and short-wave visible light through Mie scattering, medium-sized particles efficiently reflect visible light and short-wave near-infrared light, and large-sized particles efficiently reflect mid-to-long-wave near-infrared light. A single particle size can only cover part of the solar spectrum, resulting in a reflectance deficiency and a significant reduction in overall reflectance. At the same time, single-sized filler is not densely packed, the coating is prone to micropores, the water vapor permeation path increases, and the weather resistance decreases simultaneously.

[0063] Comparative Example 4, omitting the sheet-like boron nitride, and Comparative Example 5, omitting the spherical glass microspheres, showed significant decreases in solar reflectivity, mid-infrared emissivity, reflectivity retention after aging, and midday cooling rate compared to Example 1, with Comparative Example 5 exhibiting the worst cooling effect. This is because the spherical glass microspheres provide a three-dimensional protruding structure, enhancing light scattering and radiation area; while the sheet-like boron nitride provides efficient infrared emission (BN bonds) and a two-dimensional sheet structure. The combination of these two forms a micro-nano rough surface, synergistically achieving high solar reflectivity and high-mid-infrared emissivity. Using spherical microspheres alone results in insufficient infrared emission efficiency, while using sheet-like boron nitride alone results in a flat surface and weak scattering ability, neither of which can achieve the dual high optical performance of >95%.

[0064] Comparative Example 6, omitting sodium fluoroborate, showed similar initial optical properties compared to Example 1, with only a slight decrease in reflectivity (0.4%) and emissivity (0.6%). However, after 1000 hours of QUV testing, the reflectivity retention decreased by 12.2%, indicating a significant deterioration in weather resistance. The core reason is that sodium fluoroborate decomposes into fluoride and borate ions during film formation, which is beneficial for the formation of -Si-O-Si- in the silane-modified lithium silicate resin. Simultaneously, it regulates curing shrinkage stress, reduces microcracks, and slows down the rapid degradation of optical properties.

[0065] Comparative Example 7 used unmodified lithium silicate instead of silane-modified lithium silicate inorganic resin. Compared with Example 1, the solar reflectance decreased by 5.9%, the mid-infrared emissivity decreased by 4.3%, and the weather resistance decreased significantly, with a retention rate of only 80.5%. This is because unmodified lithium silicate has poor film-forming properties, resulting in low density, poor flexibility, and easy cracking of the cured coating. The filler is unevenly dispersed, and the lack of bridging effect from organosilanes leads to weak adhesion between the coating and the substrate. Under ultraviolet and humid conditions, the coating rapidly chalks and peels off, and the optical properties deteriorate drastically.

[0066] Comparative Example 8 used acrylic emulsion instead of silane-modified lithium silicate inorganic resin. Compared with Example 1, the initial reflectivity and emissivity were similar, but the weather resistance was extremely poor, with a retention rate of only 65.0%. The reason is that acrylic emulsion is an organic resin. Although it can achieve high optical performance in the short term, its molecular chain contains unsaturated bonds and ester bonds. Under ultraviolet light, oxygen, and humid heat conditions, it is prone to photo-oxidative degradation, yellowing, and chalking, which accelerates the overall failure of the coating and cannot meet the requirements for long-term outdoor use.

[0067] The results of Comparative Examples 1-6 and Example 1 fully demonstrate that the combination of barium sulfate with three particle sizes, the morphological synergy of spherical glass microspheres and plate-like boron nitride, and the promotion of weather resistance of silane-modified lithium silicate inorganic resin by sodium fluoroborate, with each component having complementary functions and synergistic effects, together achieve the unity of high solar reflectivity, high and medium infrared emissivity and ultra-long weather resistance.

[0068] It should be clarified that the above embodiments are merely illustrative of specific implementations of the present invention and do not constitute a limitation on the scope of protection of the present invention. Based on the technical content disclosed in this invention, those skilled in the art can make various modifications, adjustments, or equivalent substitutions within its basic principles and design concepts. These modifications and improvements need not be listed exhaustively, but should all be considered to fall within the scope of protection of this invention.

Claims

1. A highly weather-resistant, non-electric cooling coating, characterized in that, By weight, it includes the following components: 50-70 parts of silane-modified lithium silicate inorganic resin, 15-30 parts of barium sulfate, 5-10 parts of spherical glass microspheres, 3-6 parts of flake boron nitride, 2-5 parts of silane coupling agent, 1-3 parts of sodium fluoroborate, 0.5-1 part of dispersant, 0.3-0.8 parts of leveling agent, 1-5 parts of defoamer, 2-8 parts of thickener, and 15-60 parts of deionized water; The barium sulfate is composed of three different particle size ranges, and by total weight of the barium sulfate: barium sulfate with a particle size of 0.1-0.3 μm accounts for 20-30%, barium sulfate with a particle size of 1.0-2.5 μm accounts for 35-40%, and barium sulfate with a particle size of 4.0-10 μm accounts for 35-40%.

2. The non-electric cooling coating according to claim 1, characterized in that, The spherical glass microspheres have a diameter of 20-50 μm; the sheet-like boron nitride has a sheet diameter of 1-8 μm and a thickness of 1-20 nm.

3. The non-electric cooling coating according to claim 1, characterized in that, The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

4. The non-electric cooling coating according to any one of claims 1-3, characterized in that, The dispersant is at least one of ammonium polycarboxylate and sodium polycarboxylate; the defoamer is one or more selected from mineral oil defoamers, fluorosiloxane defoamers, organosilicon defoamers, silicone-free defoamers, and polymeric defoamers.

5. The non-electric cooling coating according to any one of claims 1-3, characterized in that, The thickener is one or more of cellulose thickener, polyurethane thickener, and polyacrylic acid thickener; the leveling agent is one or more of polyether modified polydimethylsiloxane, polyacrylate, and fluorocarbon modified polyacrylate.

6. The non-electric cooling coating according to any one of claims 1-3, characterized in that, The silane-modified lithium silicate inorganic resin comprises the following raw materials in parts by weight: 30-60 parts lithium silicate solution, 1-5 parts 3-ureapropyltriethoxysilane, 10-30 parts lithium hydroxide solution, 5-20 parts γ-aminopropyltriethoxysilane, and 5-20 parts methyltriethoxysilane.

7. The non-electric cooling coating according to claim 6, characterized in that, The lithium silicate solution has a mass concentration of 20-25% and a modulus of 4-10; the lithium hydroxide solution has a mass concentration of 5-15%.

8. A method for preparing a highly weather-resistant, non-electro-cooling coating as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Mix deionized water, dispersant, and 30-70wt% defoamer evenly, add barium sulfate, spherical glass microspheres, and flake boron nitride, and disperse at high speed to obtain slurry; (2) Add silane-modified lithium silicate inorganic resin, silane coupling agent, and sodium fluoroborate to the slurry and stir until uniform; (3) Add leveling agent, thickener and remaining defoamer, stir evenly, filter and discharge to obtain the final product.

9. The method for preparing the non-electric cooling coating according to claim 8, characterized in that, The high-speed dispersion in step (1) is carried out at a speed of 500-2500 r / min for 15-45 minutes.

10. The application of a highly weather-resistant, non-electric cooling coating as described in any one of claims 1-7 in the fields of building cooling, industrial energy conservation, logistics and transportation, new energy, or material storage.

Images