A cooling and reflection synergistic coating and a preparation method thereof

Abstract

The present application relates to the technical field of synergistic coating, and in particular to a cooling and reflection synergistic coating and a preparation method thereof, which solves the problem that the prior art can only realize limited reflection in the visible light band and cannot maintain stable cooling effect, and the heat insulation coating with part of hollow glass beads only realizes heat insulation by relying on the static air layer inside the coating and does not have the ability to actively radiate heat outward. The cooling and reflection synergistic coating and the preparation method thereof comprise a fluorocarbon resin base layer, an epoxy sealing primer layer is coated on the top of the fluorocarbon resin base layer, and the epoxy sealing primer layer is completely cured. The method proposed in the present application realizes precise parameter control of each process and orderly superposition of the layered structure, relies on the layer-by-layer adaptive combination of the fluorocarbon resin base layer, the epoxy sealing primer layer, the hollow glass bead heat insulation layer and the high reflection surface coating, and completes step-by-step coating and curing in a normal temperature environment.

Description

Technical Field

[0001] This invention relates to the field of enhancement coating technology, and in particular to a cooling and reflective enhancement coating and its preparation method. Background Technology

[0002] In scenarios where building exteriors, industrial storage tanks, photovoltaic modules, and outdoor power equipment are exposed to solar radiation for extended periods, cooling reflective coatings are core functional materials for achieving passive cooling and reducing equipment heat load. These coatings rely on the high reflectivity of shortwave solar radiation to reduce the amount of radiant heat absorbed by the substrate surface. Simultaneously, they utilize infrared radiation heat dissipation paths to dissipate the accumulated heat to the outer atmosphere. This achieves a surface cooling effect of 3°C to 15°C without additional energy consumption. It is one of the most widely used energy-saving materials in the fields of building energy conservation, industrial equipment thermal protection, and photovoltaic loss reduction. Its cooling efficiency, weather resistance, and adhesion directly determine the energy-saving benefits and equipment operational stability in the corresponding scenarios, making it an irreplaceable key functional layer in outdoor thermal protection systems.

[0003] Most commercially available cooling and reflective coatings use a single pigment-grade titanium dioxide as the reflective filler, which can only achieve limited reflection in the visible light band and cannot maintain a stable cooling effect. Some heat-insulating coatings that add hollow glass microspheres rely solely on the static air layer inside the coating for heat insulation and do not have the ability to actively radiate heat outward. In high-temperature summer environments, heat easily accumulates inside the coating, leading to heat storage and temperature reversal. This makes it difficult to meet the cooling requirements of high-heat-accumulation scenarios such as industrial high-temperature storage tanks and centralized photovoltaic power stations. At the same time, the filler in these conventional coatings has poor dispersibility, and problems such as microsphere sedimentation and pigment agglomeration are prone to occur during the preparation process. After film formation, the coating contains a large number of micron-sized pores, which can easily penetrate rainwater and oil stains during outdoor use. The internal pores contaminate the surface of the reflective filler, further reducing the coating's reflectivity. Some high-reflectivity coatings developed for photovoltaic applications add large amounts of nano-titanium dioxide filler to achieve high reflectivity, resulting in poor film formation and easy cracking and peeling. The coating's adhesion level can only reach level 2 to 3, which cannot meet the long-term adhesion requirements of low surface energy substrates such as photovoltaic glass and aluminum alloy profiles. Moreover, most existing coating preparation processes require high-temperature baking and curing, which cannot be adapted to large-area outdoor spraying construction scenarios, resulting in low construction efficiency and high overall cost, making it difficult to promote and apply in large-scale civilian energy-saving renovation projects. There is an urgent need for a cooling and reflectivity-enhancing coating and its preparation method to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a cooling and reflective enhancement coating and its preparation method, which solves the problems of existing technologies that can only achieve limited reflection in the visible light band and cannot maintain a stable cooling effect, and that heat insulation coatings with partially added hollow glass microspheres rely solely on the static air layer inside the coating to achieve heat insulation and do not have the ability to actively radiate heat outward.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A cooling and reflective enhancement coating and its preparation method are disclosed, comprising a fluorocarbon resin base layer, an epoxy sealing primer layer coated on top of the fluorocarbon resin base layer, and after the epoxy sealing primer layer is fully cured, a hollow glass microsphere heat insulation layer coated on top of the epoxy sealing primer layer, and a high reflective surface coating layer coated on top of the hollow glass microsphere heat insulation layer.

[0006] Preferably, a method for preparing a cooling and reflective enhancement coating includes the following steps: Step 1: Sandblast the surface of the substrate to be coated to completely clean the oxide layer and oil stains on the substrate surface, and control the surface roughness of the substrate to Sa2.5 level; Step 2: Mix the fluorocarbon resin, matching curing agent, and diluent in the specified proportions until homogeneous. Apply the mixture evenly to the treated substrate surface using a high-pressure airless spraying method to form a fluorocarbon resin base layer with a thickness of 30μm to 50μm. Allow it to cure at room temperature for 24 hours. Step 3: Mix the epoxy resin, curing agent, and solvent evenly, and roll them evenly onto the fully cured fluorocarbon resin substrate to form an epoxy sealing primer layer 2 with a thickness of 20μm to 30μm. Allow it to cure at room temperature for 12 hours. Step 4: Mix the hollow glass microspheres, water-based acrylic adhesive, and dispersant evenly, and apply the mixture evenly to the surface of the fully cured epoxy sealing primer layer using a scraping method to form a hollow glass microsphere heat insulation layer with a thickness of 80μm to 120μm. Allow it to cure at room temperature for 36 hours. Step 5: Mix nano-titanium dioxide, infrared radiation powder, and fluorocarbon varnish evenly, and spray the mixture evenly onto the surface of the fully cured hollow glass microsphere insulation layer using air spraying to form a high-reflectivity coating with a thickness of 40μm to 60μm. After complete curing at room temperature, the preparation is complete.

[0007] Preferably, the substrate to be coated is selected from metal, concrete, or photovoltaic glass. Brown corundum abrasive with a particle size of 60 to 80 mesh is used to uniformly sandblast the entire surface of the substrate using a sandblasting device with a pressure of 0.6 MPa to 0.8 MPa. After sandblasting, the substrate surface is repeatedly blown with dry compressed air 3 to 5 times to completely remove the residual sand particles and dust. Then, the substrate surface is wiped twice with a lint-free wiping cloth soaked in anhydrous ethanol to completely remove the oil stains and residual impurities attached to the surface. Let it stand for 15 to 20 minutes to allow the ethanol on the substrate surface to completely evaporate.

[0008] Preferably, 90 parts by weight of fluorocarbon resin stock solution are weighed and poured into a stainless steel mixing vessel with a sealed lid. The stirring speed is set to 300 r / min. While stirring, 10 parts by weight of isocyanate curing agent are slowly added. During the stirring process, 15 parts by weight of butyl acetate diluent are added in three intervals. Stirring is continued for 25 to 30 minutes. After stirring, the mixture is filtered through a 120-mesh nylon filter. The filtered liquid is poured into the material tank of a high-pressure airless spraying equipment. The spraying pressure is set to 12 MPa to 15 MPa. The spray gun is kept at a vertical distance of 30 cm to 40 cm from the substrate surface. The gun is moved horizontally at a uniform speed for spraying. After the first pass, a second pass is sprayed by moving the gun vertically in a crisscross pattern. After spraying, the mixture is left to stand for 24 hours in a dust-free environment at a room temperature of 23°C to 25°C to form a fluorocarbon resin base layer with a thickness of 30 μm to 50 μm.

[0009] Preferably, 85 parts by weight of bisphenol A type epoxy resin are weighed and poured into a mixing container. The stirring speed is set to 250 r / min. While stirring, 15 parts by weight of modified amine curing agent are slowly added. Stirring is continued for 15 to 20 minutes. During stirring, 8 parts by weight of xylene solvent is added to adjust the viscosity of the liquid. After stirring, the liquid is filtered through a 100-mesh filter. The filtered liquid is poured into the trough of a roller coating equipment. A polyurethane rubber roller with a Shore hardness of 45 is used to uniformly roll coat the fully cured fluorocarbon resin substrate in one direction. After roller coating, the substrate is left to stand in a dust-free environment at room temperature for 12 hours to form an epoxy sealing primer layer with a thickness of 20 μm to 30 μm. 45 parts by weight of... Water-based acrylic adhesive is poured into a heated mixing tank. The mixing speed is set to 400 r / min. While stirring, 35 parts by weight of hollow glass microspheres with a particle size of 20 μm to 40 μm are slowly added. 5 parts by weight of polyacrylate dispersant are added in two separate additions. Stirring is continued for 40 to 45 minutes. During the stirring process, the temperature inside the tank is controlled not to exceed 40℃. After stirring, the mixed slurry is poured into the hopper of a serrated coating device. A stainless steel scraper with a tooth pitch of 1 mm is used to uniformly coat the fully cured epoxy sealing primer layer. After coating, the mixture is left to stand in a dust-free environment at room temperature for 36 hours to form a hollow glass microsphere insulation layer with a thickness of 80 μm to 120 μm.

[0010] Preferably, 70 parts by weight of fluorocarbon varnish are weighed and poured into a mixing container. The stirring speed is set to 350 r / min. While stirring, 18 parts by weight of rutile nano-titanium dioxide with a particle size of 50 nm to 80 nm are slowly added, followed by 12 parts by weight of silicon carbide infrared radiation powder. The mixture is stirred continuously for 30 to 35 minutes. After stirring, the mixture is filtered through a 180-mesh nylon filter. The filtered liquid is poured into the material cup of a gravity air spraying device. The spraying air pressure is set to 0.4 MPa to 0.5 MPa. The spray gun is kept at a vertical distance of 25 cm to 35 cm from the surface of the hollow glass microsphere insulation layer. The first coat is sprayed horizontally at a uniform speed. After a 15-minute interval, the second coat is sprayed vertically in a cross direction. After spraying, the mixture is left to stand in a dust-free environment at room temperature for 48 hours to form a high-reflectivity coating with a thickness of 40 μm to 60 μm.

[0011] This invention has at least the following beneficial effects: The preparation process of the cooling and reflective enhancement coating of this invention achieves continuous multi-layer functional coating through precise parameter control of each process and orderly superposition of layered structures. Relying on the layer-by-layer adaptation and combination of fluorocarbon resin base layer, epoxy sealing primer layer, hollow glass microsphere heat insulation layer and high reflective surface coating, the entire process is completed in a step-by-step coating and curing environment at room temperature. It can achieve continuous preparation of multi-layer functional coating without the need for high-temperature baking equipment. The material ratio, stirring parameters, operation specifications of spraying, roller coating and scraping, and static curing time of each coating process are matched with each other, adapting to the coating needs of various substrates such as metal, concrete, and photovoltaic glass. The entire preparation process has clear and controllable operation steps, and can be adapted to two different construction scenarios: factory pre-coating and outdoor large-area spraying. It can complete large-scale batch preparation without complex special equipment, providing a complete and directly applicable operation path for the standardized mass production and large-scale application of cooling and reflective functional coatings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the structure of each coating of the present invention.

[0014] In the diagram: 1. Fluorocarbon resin base layer; 2. Epoxy sealing primer layer; 3. Hollow glass microsphere insulation layer; 4. High reflective surface coating. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] Example 1 Reference Figure 1 The system includes a fluorocarbon resin base layer 1, an epoxy sealing primer layer 2 coated on top of the fluorocarbon resin base layer 1, and after the epoxy sealing primer layer 2 is fully cured, a hollow glass microsphere heat insulation layer 3 is coated on top of the epoxy sealing primer layer 2, and a high-reflectivity surface coating layer is coated on top of the hollow glass microsphere heat insulation layer 3. Through the arrangement of the fluorocarbon resin base layer 1, epoxy sealing primer layer 2, hollow glass microsphere heat insulation layer 3, and high-reflectivity surface coating layer 4, the four coatings are applied sequentially from bottom to top. After the lower coating layer is fully cured, the upper coating layer is applied, thus achieving the effect of forming a layered cooling and reflective composite coating structure with clear functions.

[0017] Example 2 Reference Figure 1 A method for preparing a cooling and reflective enhancement coating includes the following steps: Step 1: Sandblast the surface of the substrate to be coated to completely clean the oxide layer and oil stains on the substrate surface, and control the surface roughness of the substrate to Sa2.5 level; Step 2: Mix the fluorocarbon resin, matching curing agent, and diluent in the specified proportions until homogeneous. Apply the mixture evenly to the treated substrate surface using a high-pressure airless spraying method to form a fluorocarbon resin base layer 1 with a thickness of 30μm to 50μm. Allow it to cure at room temperature for 24 hours. Step 3: Mix the epoxy resin, curing agent, and solvent evenly, and roll them evenly onto the surface of the fully cured fluorocarbon resin base layer 1 to form an epoxy sealing primer layer 2 with a thickness of 20μm to 30μm. Allow it to cure at room temperature for 12 hours. Step 4: Mix the hollow glass microspheres, water-based acrylic adhesive, and dispersant evenly, and apply them evenly to the surface of the fully cured epoxy sealing primer layer 2 using a scraping method to form a hollow glass microsphere heat insulation layer 3 with a thickness of 80μm to 120μm. Allow it to cure at room temperature for 36 hours. Step 5: Mix nano-titanium dioxide, infrared radiation powder, and fluorocarbon varnish evenly, and spray them evenly on the surface of the fully cured hollow glass microsphere heat insulation layer 3 using air spraying to form a high-reflectivity coating 4 with a thickness of 40μm to 60μm. After being left to stand at room temperature for complete curing, the preparation is complete.

[0018] By employing a set procedure—substrate sandblasting, fluorocarbon resin base coat 1 spraying, epoxy sealing primer layer 2 roller coating, hollow glass microsphere insulation layer 3 scraping, and high-reflectivity surface coating 4 spraying—each layer is applied and cured sequentially according to a fixed process order, thus achieving the desired effect of establishing a basic preparation process for a cooling and reflective enhancement coating. Example 3 Select the metal, concrete, or photovoltaic glass substrate to be coated. Use brown corundum abrasive with a particle size of 60 to 80 mesh. Use a sandblasting device with a pressure of 0.6 MPa to 0.8 MPa to uniformly sandblast the entire surface of the substrate. After sandblasting, use dry compressed air to repeatedly blow the surface of the substrate 3 to 5 times to completely remove the sand particles and dust remaining on the surface. Then, use a lint-free wiping cloth soaked in anhydrous ethanol to wipe the surface of the substrate twice to completely remove the oil stains and residual impurities attached to the surface. Let it stand for 15 to 20 minutes to allow the ethanol on the surface of the substrate to completely evaporate.

[0019] By using 60-80 mesh brown fused alumina abrasive, 0.6MPa-0.8MPa sandblasting equipment, dry compressed air, and anhydrous ethanol dust-free wiping cloth, the substrate sandblasting, dust blowing, and surface oil wiping are completed in sequence, achieving the effect of completing the entire process of substrate surface pretreatment.

[0020] Example 4 Weigh 90 parts by weight of fluorocarbon resin stock solution and pour it into a stainless steel mixing vessel with a sealed lid. Set the stirring speed to 300 r / min and slowly add 10 parts by weight of isocyanate curing agent while stirring. During the stirring process, add 15 parts by weight of butyl acetate diluent in 3 intervals. Continue stirring for 25 to 30 minutes. After stirring, filter the mixture through a 120-mesh nylon filter. Pour the filtered liquid into the material tank of a high-pressure airless spraying equipment. Set the spraying pressure to 12 MPa to 15 MPa. Keep the spray gun at a vertical distance of 30 cm to 40 cm from the substrate surface and spray at a uniform speed in the horizontal direction. After the first pass, spray the second pass in a cross direction in the vertical direction. After spraying, let it stand for 24 hours in a dust-free environment at room temperature (23°C to 25°C) to form a fluorocarbon resin base layer with a thickness of 30 μm to 50 μm.

[0021] By using 90 parts by weight of fluorocarbon resin stock solution, 10 parts by weight of isocyanate curing agent, 15 parts by weight of butyl acetate diluent, and a high-pressure airless spraying equipment, the fluorocarbon resin base layer 1 was accurately prepared by cross-spraying the material after mixing and filtering according to the parameters.

[0022] Example 5 Weigh 85 parts by weight of bisphenol A type epoxy resin and pour it into a mixing container. Set the stirring speed to 250 r / min and slowly add 15 parts by weight of modified amine curing agent while stirring. Continue stirring for 15 to 20 minutes. During the stirring process, add 8 parts by weight of xylene solvent to adjust the viscosity of the liquid. After stirring, filter the liquid through a 100-mesh filter and pour the filtered liquid into the material tank of a roller coating equipment. Select a polyurethane rubber roller with a Shore hardness of 45 and roll it uniformly in one direction on the surface of the fully cured fluorocarbon resin base layer 1. After roller coating, let it stand in a dust-free environment at room temperature for 12 hours to form an epoxy sealing primer layer 2 with a thickness of 20 μm to 30 μm. Weigh 45 parts by weight of water. The acrylic adhesive is poured into a heated mixing tank. The stirring speed is set to 400 r / min. While stirring, 35 parts by weight of hollow glass microspheres with a particle size of 20 μm to 40 μm are slowly added. 5 parts by weight of polyacrylate dispersant are added in two separate additions. Stirring is continued for 40 to 45 minutes. During the stirring process, the temperature inside the tank is controlled not to exceed 40℃. After stirring, the mixed slurry is poured into the hopper of a serrated coating device. A stainless steel scraper with a tooth pitch of 1 mm is used to uniformly coat the fully cured epoxy sealing primer layer 2. After coating, the mixture is left to stand in a dust-free environment at room temperature for 36 hours to form a hollow glass microsphere insulation layer 3 with a thickness of 80 μm to 120 μm.

[0023] By using 85 parts by weight of bisphenol A epoxy resin, 15 parts by weight of modified amine curing agent, 8 parts by weight of xylene solvent, and a polyurethane rubber roller with a Shore hardness of 45, the epoxy sealing primer layer 2 was prepared by roller coating. Then, by using 45 parts by weight of water-based acrylic adhesive, 35 parts by weight of 20μm to 40μm hollow glass microspheres, 5 parts by weight of polyacrylate dispersant, and a stainless steel scraper with a tooth pitch of 1mm, the hollow glass microsphere heat insulation layer 3 was prepared by scraping. This achieved the effect of accurately preparing the two intermediate functional coating layers.

[0024] Example 6 Weigh 70 parts by weight of fluorocarbon varnish and pour it into a mixing container. Set the stirring speed to 350 r / min. While stirring, slowly add 18 parts by weight of rutile nano-titanium dioxide with a particle size of 50 nm to 80 nm, and then add 12 parts by weight of silicon carbide infrared radiation powder. Continue stirring for 30 to 35 minutes. After stirring, filter the mixture through a 180-mesh nylon filter. Pour the filtered liquid into the material cup of a gravity air spraying device. Set the spraying air pressure to 0.4 MPa to 0.5 MPa. Maintain a vertical distance of 25 cm to 35 cm between the spray gun and the surface of the hollow glass microsphere insulation layer 3. First, spray the first coat at a uniform speed in the horizontal direction. After a 15-minute interval, spray the second coat in a cross direction in the vertical direction. After spraying, let it stand in a dust-free environment at room temperature for 48 hours to form a high-reflectivity coating 4 with a thickness of 40 μm to 60 μm.

[0025] By using 70 parts by weight of fluorocarbon varnish, 18 parts by weight of 50nm to 80nm rutile nano-titanium dioxide, 12 parts by weight of silicon carbide infrared radiation powder, and gravity-type air spraying equipment, the high-reflectivity surface coating 4 was accurately prepared by cross-spraying after material mixing and filtration.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A cooling and reflective enhancement coating, comprising a fluorocarbon resin base layer (1), characterized in that, The top of the fluorocarbon resin base layer (1) is coated with an epoxy sealing primer layer (2), and after the epoxy sealing primer layer (2) is completely cured, the top of the epoxy sealing primer layer (2) is coated with a hollow glass microsphere heat insulation layer (3), and the top of the hollow glass microsphere heat insulation layer (3) is coated with a high reflective surface coating layer (4).

2. A method for preparing a cooling and reflective enhancement coating, characterized in that, The preparation method utilizes the cooling and reflective enhancement coating as described in claim 1, and includes the following steps: Step 1: Sandblast the surface of the substrate to be coated to completely clean the oxide layer and oil stains on the substrate surface, and control the surface roughness of the substrate to Sa2.5 level; Step 2: Mix the fluorocarbon resin, matching curing agent and diluent in proportion and stir evenly. Apply the mixture evenly to the surface of the treated substrate using high-pressure airless spraying to form a fluorocarbon resin base layer with a thickness of 30μm to 50μm (1). Allow it to stand at room temperature for 24 hours to cure. Step 3: Mix the epoxy resin, curing agent and solvent evenly, and roll them evenly on the surface of the fully cured fluorocarbon resin base layer (1) to form an epoxy sealing primer layer (2) with a thickness of 20μm to 30μm. Let it stand at room temperature for 12 hours to cure. Step 4: Mix the hollow glass microspheres, water-based acrylic adhesive, and dispersant evenly, and apply them evenly to the surface of the fully cured epoxy sealing primer layer (2) by scraping, to form a hollow glass microsphere heat insulation layer (3) with a thickness of 80μm to 120μm, and let it stand at room temperature for 36 hours to cure. Step 5: Mix nano-titanium dioxide, infrared radiation powder and fluorocarbon varnish evenly, and spray them evenly on the surface of the fully cured hollow glass microsphere heat insulation layer (3) by air spraying to form a high reflective coating (4) with a thickness of 40μm to 60μm. After being left to stand at room temperature to fully cure, the preparation is completed.

3. The method for preparing a cooling and reflective enhancement coating according to claim 2, characterized in that, The process involves selecting a metal, concrete, or photovoltaic glass substrate to be coated, using brown corundum abrasive with a particle size of 60 to 80 mesh, and uniformly sandblasting the entire surface of the substrate using a sandblasting device with a pressure of 0.6 MPa to 0.8 MPa. After sandblasting, the substrate surface is repeatedly blown with dry compressed air 3 to 5 times to completely remove any remaining sand particles and dust. Then, the substrate surface is wiped twice with a lint-free cloth soaked in anhydrous ethanol to completely remove any oil stains and residual impurities. The substrate is then left to stand for 15 to 20 minutes to allow the ethanol on the substrate surface to completely evaporate.

4. The method for preparing a cooling and reflective enhancement coating according to claim 2, characterized in that, 90 parts by weight of fluorocarbon resin stock solution were weighed and poured into a stainless steel mixing tank with a sealed lid. The stirring speed was set to 300 r / min. While stirring, 10 parts by weight of isocyanate curing agent were slowly added. During the stirring process, 15 parts by weight of butyl acetate diluent were added in 3 intervals. The stirring was continued for 25 to 30 minutes. After stirring, the mixture was filtered through a 120-mesh nylon filter. The filtered liquid was poured into the material tank of a high-pressure airless spraying equipment. The spraying pressure was set to 12 MPa to 15 MPa. The spray gun was kept at a vertical distance of 30 cm to 40 cm from the substrate surface. The gun was moved horizontally at a uniform speed for spraying. After the first pass, the second pass was sprayed by moving the gun vertically in a cross direction. After spraying, the mixture was left to stand in a dust-free environment at a room temperature of 23°C to 25°C for 24 hours to form a fluorocarbon resin base layer with a thickness of 30 μm to 50 μm (1).

5. The method for preparing a cooling and reflective enhancement coating according to claim 2, characterized in that, 85 parts by weight of bisphenol A epoxy resin were weighed and poured into a mixing container. The stirring speed was set to 250 r / min. While stirring, 15 parts by weight of modified amine curing agent were slowly added. Stirring was continued for 15 to 20 minutes. During the stirring process, 8 parts by weight of xylene solvent were added to adjust the viscosity of the liquid. After stirring, the liquid was filtered through a 100-mesh filter and poured into the material tank of the roller coating equipment. A polyurethane rubber roller with a Shore hardness of 45 was selected and rolled uniformly in one direction on the surface of the fully cured fluorocarbon resin base layer (1). After the roller coating was completed, the mixture was left to stand in a dust-free environment at room temperature for 12 hours to form an epoxy sealing primer layer (2) with a thickness of 20 μm to 30 μm. 45 parts by weight of bisphenol A epoxy resin were weighed and poured into a mixing container. Water-based acrylic adhesive is poured into a heated mixing tank. The stirring speed is set to 400 r / min. While stirring, 35 parts by weight of hollow glass microspheres with a particle size of 20 μm to 40 μm are slowly added. 5 parts by weight of polyacrylate dispersant are added in two separate additions. Stirring is continued for 40 to 45 minutes. During the stirring process, the temperature inside the tank is controlled not to exceed 40℃. After stirring, the mixed slurry is poured into the hopper of a serrated scraping device. A stainless steel scraper with a tooth pitch of 1 mm is used to scrape the fully cured epoxy sealing primer layer (2) at a uniform speed. After scraping, the layer is left to stand in a dust-free environment at room temperature for 36 hours to form a hollow glass microsphere heat insulation layer (3) with a thickness of 80 μm to 120 μm.

6. The method for preparing a cooling and reflective enhancement coating according to claim 2, characterized in that, Weigh 70 parts by weight of fluorocarbon varnish and pour it into a mixing container. Set the stirring speed to 350 r / min. While stirring, slowly add 18 parts by weight of rutile nano-titanium dioxide with a particle size of 50 nm to 80 nm, and then add 12 parts by weight of silicon carbide infrared radiation powder. Continue stirring for 30 to 35 minutes. After stirring, filter the mixture with a 180-mesh nylon filter. Pour the filtered liquid into the material cup of a gravity air spraying device. Set the spraying air pressure to 0.4 MPa to 0.5 MPa. Keep the spray gun at a vertical distance of 25 cm to 35 cm from the surface of the hollow glass microsphere heat insulation layer (3). First, spray the first coat at a uniform speed in the horizontal direction. After an interval of 15 minutes, spray the second coat in a cross direction in the vertical direction. After spraying, let it stand in a dust-free environment at room temperature for 48 hours to form a high-reflectivity coating (4) with a thickness of 40 μm to 60 μm.

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