High-temperature radiation refrigeration coating with protection function and preparation method thereof

Abstract

The present application relates to a kind of high temperature radiation refrigeration coating with protection function, which is composed of the following mass parts of raw materials: radiation refrigeration pigment 20~35 parts, protective filler 4~6 parts, binder 20~40 parts, dispersing agent 3~5 parts, wetting agent 3~5 parts, defoaming agent 1~3 parts, leveling agent 1~3 parts and di-n-butyl ether 15~25 parts. At the same time, the preparation method of the high temperature radiation refrigeration coating is also disclosed. The present application has simple process, low cost, can realize large-scale industrial production, and the obtained coating not only has excellent radiation refrigeration performance, but also shows good high temperature resistance, corrosion resistance, wear resistance, radiation resistance and electrical insulation and other protection performance, which can be widely used in many fields such as large oil storage tank, large power equipment, thermal power generation, building refrigeration, photovoltaic power generation and so on.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature control coatings, in particular to a high-temperature radiation refrigeration coating with a protective function and a preparation method thereof. BACKGROUND

[0002] With the continuous warming of the global climate, the surface temperature rises, and the urban heat island effect is greatly intensified. The proportion of refrigeration energy consumption continues to rise, and the traditional vapor compression cooling strategy, such as air conditioning, consumes a large amount of fossil fuels, leading to increased carbon emissions, further exacerbating the global climate. As a zero-energy and zero-pollution refrigeration technology, radiation refrigeration provides a new opportunity for sustainable carbon neutralization.

[0003] Radiation refrigeration can transfer the heat of the earth to outer space in the form of thermal radiation through the atmospheric window (8-13 µm), without any energy input. During the day, it achieves a cooling effect below the ambient temperature by minimizing solar energy (0.3-2.5 µm) absorption. This zero-energy and efficient cooling method provides new strategies and opportunities for the development of global energy-saving fields. At present, through the design of spectral selective materials with high reflectivity of solar spectrum and high emissivity of atmospheric window, all-weather radiation refrigeration has been achieved. For example, the invention patent CN115558351 provides a method for improving the radiation refrigeration performance of radiation refrigeration coating, which improves the radiation refrigeration effect by fully utilizing the reflection of fillers to light and the radiation of heat; the invention patent CN116445074 provides a non-energy consumption radiation refrigeration coating, a preparation method and application thereof. The prepared cooling coating has significantly improved cooling efficiency and has broad application prospects. However, these coatings are high in cost, poor in mechanical properties, and single in function, and are only suitable for sub-ambient radiation refrigeration under room temperature conditions. They cannot work stably for a long time in complex outdoor environments. For high-temperature environments such as data centers, vehicles, and communication base stations, due to the huge internal heat, the temperature is usually higher than the ambient temperature, and the refrigeration application cannot be used for long-term exposure to outdoor conditions.

[0004] Therefore, there is an urgent need for a high-temperature radiation refrigeration coating material with a protective function that is resistant to high temperature, corrosion, wear and tear, and high thermal conductivity, in order to greatly expand the potential applications of this energy-saving cooling technology. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high-temperature radiation refrigeration coating with a protective function with good performance.

[0006] Another technical problem to be solved by the present application is to provide a preparation method of the high-temperature radiation refrigeration coating with a protective function.

[0007] To solve the above problems, the high-temperature radiation refrigeration coating with protection function has the characteristics that the coating is composed of the following raw materials in mass fraction: radiation refrigeration pigment 20-35 parts, protective filler 4-6 parts, binder 20-40 parts, dispersing agent 3-5 parts, wetting agent 3-5 parts, defoaming agent 1-3 parts, leveling agent 1-3 parts and di-n-butyl ether 15-25 parts.

[0008] The thickness of the coating is 150-250 microns, the reflectivity is greater than 0.95, the emissivity is greater than 0.94, and the high-temperature resistance is greater than 800 DEG C.

[0009] The radiation refrigeration pigment is composed of not less than one kind of compound of aluminum oxide, silicon oxide, barium sulfate and calcium carbonate, and the particle size of each compound pigment is between 100 nanometers and 2 microns, the electron band gap is between 6 electron volts and 9 electron volts, and the refractive index is between 1.5 and 2.0.

[0010] The protective filler is composed of not less than one kind of compound of silicon carbide, zirconium oxide and boron nitride, and the particle size of each filler is between 500 nanometers and 10 microns.

[0011] The binder is one or both of perhydrogen polysilazane and polyurea silazane.

[0012] The dispersing agent is one or both of AFCONA-4011, BYK-1165 and ANTI-TERRA-U 100.

[0013] The wetting agent is one or both of AFCONA-5008, ANTI-TERRA-203 and BYKUMEN.

[0014] The defoaming agent is one or both of BYK-070, AFCONA-2791 and BYK-1788.

[0015] The leveling agent is one or both of CERATIX 8566, AFCONA-3030 and RHEOBYK-431.

[0016] The preparation method of the high-temperature radiation refrigeration coating with protection function as described above comprises the following steps:

[0017] (1) weighing according to the proportion;

[0018] 2. The high-temperature radiation refrigeration coating is prepared by the following steps: 1. mixing and dispersing uniformly di-n-butyl ether, a binder, a wetting agent, a dispersing agent, an antifoaming agent and a leveling agent, and then adding the radiation refrigeration pigment and the protective filler to the mixture, stirring at a rotating speed of 400-800 r / min for 60-100 min by using a high-speed dispersion machine, and then dispersing and grinding by using a sand mill or a ball mill until the fineness is 10-20 microns, and then filtering by using a 100-200 mesh silk screen to obtain the high-temperature radiation refrigeration coating, and sealing and storing;

[0019] 4. The surface of the substrate is sandblasted by using quartz stone or brown corundum with a particle size of 1-5 microns, so that the cleanliness of the surface of the substrate reaches the requirement of Sa 2.5-3.0 level.

[0020] 5. The high-temperature radiation refrigeration coating with the protective function is obtained by the following steps: spraying twice by using 0.8 MPa compressed air under the conditions that the ambient temperature is 15-30 DEG C and the relative humidity of air is less than 85%, and then curing at room temperature after spraying.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The polysilazane resin binder used in the present application has a high melting point (1500-2000 DEG C), and the molecular structure is very stable due to the existence of silicon-nitrogen bond and carbon-nitrogen bond, so that the binder has excellent stability in a high-temperature environment; and the binder contains silicon, nitrogen and carbon elements, so that the radiation refrigeration coating material has strong corrosion resistance, wear resistance, radiation resistance and electrical insulation, and can maintain its performance unchanged in a complex outdoor working environment, thereby greatly enhancing the service life of the coating in harsh environments.

[0023] 2. In the present application, silicon carbide (SiC), hexagonal boron nitride (HBN) and zirconium oxide (ZrO2) are added as protective fillers, and these materials have stable chemical properties, high-temperature resistance, corrosion resistance, oxidation resistance and good wear resistance; the silicon carbide (SiC) and the hexagonal boron nitride (HBN) also have the characteristics of high thermal conductivity and small thermal expansion coefficient, so that the heat generated inside can be effectively conducted out, and the safety hidden danger caused by frequent changes of thermal load under high temperature conditions can be relieved; the high-refractive zirconium dioxide (ZrO2) improves the original dielectric contrast, causes a series of forward and backward scattering events, and effectively improves the light reflection performance of the material; and the metastable tetragonal phase zirconium dioxide also improves the mechanical strength of the material. Therefore, the coating is added with a protective layer due to a series of special properties of these materials, and the practicability for outdoor application is effectively improved.

[0024] 3、The application adds aluminum oxide (Al2O3), silicon oxide (SiO2), barium sulfate (BaSO4), calcium carbonate (CaCO3) with different energy band structures as the radiative cooling pigment, the pigment uses several different band gap fillers to coordinate the contradiction between the refractive index and the extinction coefficient, so that the pigment has excellent spectral selection performance, shows high refractive index (n) and low extinction coefficient (k), which further improves the original dielectric contrast, realizes effective multiple scattering of sunlight. In addition, the complex crystal structure and the appropriate bond strength cause the infrared phonon vibration, thereby improving the light reflection performance and the infrared radiation performance of the material, and showing good radiative cooling performance (as shown in Figures 1-3 ).

[0025] 4、The application has simple process, low cost, high production efficiency, does not need complex treatment process, and can realize large-scale industrial production.

[0026] 5、The coating has excellent radiative cooling performance, and also shows good protective performances such as high-temperature resistance, corrosion resistance, wear resistance, radiation resistance and electrical insulation, and can be widely applied to many fields such as large oil storage tanks, large power equipment, thermal power generation, building cooling, photovoltaic power generation and the like. BRIEF DESCRIPTION OF DRAWINGS

[0027] The specific embodiments of the application will be further described in detail below with reference to the accompanying drawings.

[0028] Figure 1 The solar reflectance spectrum diagram of the high-temperature radiative cooling coating with protective function of the application embodiment 1 in the 0.3-2.5 μm wave band.

[0029] Figure 2 The infrared emission spectrum diagram of the high-temperature radiative cooling coating with protective function of the application embodiment 1 in the 2.5-16 μm wave band.

[0030] Figure 3 The outdoor cooling test of the high-temperature radiative cooling coating with protective function of the application embodiment 1. DETAILED DESCRIPTION

[0031] A high-temperature radiative cooling coating with protective function, which is composed of the following raw materials in mass fraction (g): radiative cooling pigment 20-35 parts, protective filler 4-6 parts, binder 20-40 parts, dispersant 3-5 parts, wetting agent 3-5 parts, defoaming agent 1-3 parts, leveling agent 1-3 parts and di-n-butyl ether 15-25 parts. The thickness of the coating is 150-250 microns, the reflectivity is greater than 0.95, the emissivity is greater than 0.94, and the high-temperature resistance is greater than 800℃.

[0032] The radiation cooling pigment is composed of not less than one of aluminum oxide, silicon oxide, barium sulfate, and calcium carbonate, and each of the composite pigments has a particle size of 100 nm to 2 microns, an electron band gap of 6 electron volts to 9 electron volts, and a refractive index of 1.5 to 2.0.

[0033] The protective filler is composed of not less than one of silicon carbide, zirconium oxide, and boron nitride, and each of the fillers has a particle size of 500 nm to 10 microns.

[0034] The binder is one or both of perhydropolysilazane and polyureasilazane.

[0035] The dispersant is one or both of AFCONA-4011, BYK-1165, and ANTI-TERRA-U 100.

[0036] The wetting agent is one or both of AFCONA-5008, ANTI-TERRA-203, and BYKUMEN.

[0037] The defoaming agent is one or both of BYK-070, AFCONA-2791, and BYK-1788.

[0038] The leveling agent is one or both of CERATIX 8566, AFCONA-3030, and RHEOBYK-431.

[0039] A preparation method of a high-temperature radiation cooling coating with a protective function, comprising the following steps:

[0040] (1) weighing according to the ratio;

[0041] (2) mixing and uniformly dispersing di-n-butyl ether, a binder, a wetting agent, a dispersant, a defoaming agent, and a leveling agent, then adding radiation cooling pigments and protective fillers, using a high-speed dispersion machine to stir at a speed of 400-800 r / min for 60-100 min, then using a sand mill or a ball mill to disperse and grind to a fineness of 10-20 microns, and then filtering with a 100-200 mesh silk screen to obtain a high-temperature radiation cooling coating, which is sealed and stored;

[0042] (3) sandblasting the surface of the substrate using quartz stone or brown corundum with a particle size of 1-5 microns to make the cleanliness of the substrate surface reach the requirement of Sa 2.5-3.0;

[0043] (4) under the condition of an ambient temperature of 15-30℃ and an air relative humidity of less than 85%, spraying twice using 0.8 MPa compressed air, and then curing at room temperature after spraying to obtain a high-temperature radiation cooling coating with a protective function.

[0044] Example 1 A high-temperature radiant refrigeration coating with a protective function, which is composed of the following raw materials: 10 g of alumina, 10 g of silicon oxide, 5 g of barium sulfate, 5 g of calcium carbonate, 1 g of silicon carbide, 1 g of zirconium oxide, 2 g of boron nitride, 40 g of perhydro-polysilazane, 1.5 g of dispersant (BYK-1165) + 1.5 g of dispersant (ANTI-TERRA-U 100), 1.5 g of wetting agent (ANTI-TERRA-203) + 1.5 g of wetting agent (BYKUMEN), 1.0 g of defoaming agent (BYK-070), 1.0 g of leveling agent (RHEOBYK-431), and 18 g of di-n-butyl ether.

[0045] The preparation method thereof comprises the following steps:

[0046] 1. Weigh according to the proportion;

[0047] 2. Mix and disperse the di-n-butyl ether, perhydro-polysilazane, wetting agent, dispersant, defoaming agent, and leveling agent uniformly, then add the alumina, silicon oxide, barium sulfate, calcium carbonate, silicon carbide, zirconium oxide, and boron nitride, use a high-speed dispersion machine to stir at a speed of 400-800 r / min for 60-100 min, then use a sand mill or a ball mill to disperse and grind to a fineness of 10-20 μm, and then filter with a 100-200 mesh silk screen to obtain the high-temperature radiant refrigeration coating, which is sealed and stored;

[0048] 3. Use quartz stone or brown corundum with a particle size of 1-5 μm to perform sandblasting treatment on the surface of the substrate, so that the cleanliness of the surface of the substrate reaches the requirement of Sa 2.5-3.0 level;

[0049] 4. Under the condition that the ambient temperature is 15-30 ℃ and the relative humidity of air is less than 85%, use 0.8 MPa compressed air to spray twice, and then stand at room temperature for solidification after the spraying is completed, to obtain the high-temperature radiant refrigeration coating with a protective function.

[0050] The performance indicators of the obtained coating are shown in Table 1.

[0051] Table 1

[0052]

[0053] Example 2 A high-temperature radiant refrigeration coating with a protective function, which is composed of the following raw materials: 10 g of alumina, 10 g of barium sulfate, 5 g of silicon oxide, 10 g of calcium carbonate, 1 g of silicon carbide, 1 g of zirconium oxide, 2 g of boron nitride, 35 g of perhydro-polysilazane, 3.5 g of dispersant (AFCONA-4011), 3.5 g of wetting agent (SAFCONA-5008), 2 g of defoaming agent (AFCONA-2791), 2 g of leveling agent (AFCONA-3030), and 15 g of di-n-butyl ether.

[0054] A preparation method thereof comprises the following steps:

[0055] 1. Weighing according to the proportion;

[0056] 2. Mixing and uniformly dispersing di-n-butyl ether, per-hydrogenated polysilazane, wetting agent, dispersant, defoaming agent and leveling agent, then adding alumina, barium sulfate, silicon oxide, calcium carbonate, silicon carbide, zirconium oxide and boron nitride, using a high-speed dispersion machine to stir at a speed of 400-800 r / min for 60-100 min, then using a sand mill or a ball mill to disperse and grind to a fineness of 10-20 μm, and then filtering with a 100-200 mesh silk screen to obtain the high-temperature radiation refrigeration coating, which is sealed and stored;

[0057] 3. Using quartz stone or brown corundum with a particle size of 1-5 μm to sandblast the surface of the substrate to make the cleanliness of the surface of the substrate reach the requirement of Sa 2.5-3.0 level;

[0058] 4. Under the condition that the ambient temperature is 15-30 ℃ and the relative humidity of air is less than 85%, using 0.8 MPa compressed air to spray twice, and then standing at room temperature to solidify after spraying to obtain the high-temperature radiation refrigeration coating with a protective function.

[0059] The performance indexes of the obtained coating are shown in Table 2.

[0060] Table 2

[0061]

[0062] Example 3 A high-temperature radiation refrigeration coating with a protective function, which is composed of the following raw materials: 10 g of alumina, 10 g of barium sulfate, 6 g of silicon oxide, 7 g of calcium carbonate, 2 g of silicon carbide, 2 g of zirconium oxide, 2 g of boron nitride, 20 g of polyurea silazane, 2.5 g of dispersant (BYK-1165) + 2.5 g of dispersant (ANTI-TERRA-U 100), 2.5 g of wetting agent (ANTI-TERRA-203) + 2.5 g of wetting agent (BYKUMEN), 3.0 g of defoaming agent (BYK-070), 3.0 g of leveling agent (RHEOBYK-431) and 25 g of di-n-butyl ether.

[0063] A preparation method thereof comprises the following steps:

[0064] 1. Weighing according to the proportion;

[0065] (2) After uniformly dispersing di-n-butyl ether, polyurea silazane, wetting agent, dispersant, defoamer, and leveling agent, add alumina, barium sulfate, silicon dioxide, calcium carbonate, silicon carbide, zirconium oxide, and boron nitride. Use a high-speed disperser to stir at a speed of 400~800 r / min for 60~100 min, then use a sand mill or ball mill to disperse and grind to a fineness of 10~20 μm. Finally, filter with a 100~200 mesh screen to obtain the high-temperature radiation cooling coating, which should be sealed and stored.

[0066] (3) Use quartz stone or brown corundum with a particle size of 1~5μm to sandblast the substrate surface so that the surface cleanliness of the substrate meets the requirements of Sa 2.5~3.0.

[0067] (4) Under the conditions of ambient temperature of 15~30℃ and relative humidity of air below 85%, spray twice with 0.8MPa compressed air. After spraying, let it stand at room temperature to cure, and a high-temperature radiation cooling coating with protective function is obtained.

[0068] The performance indicators of the obtained coating are shown in Table 3.

[0069] Table 3

[0070]

[0071] Example 4 A high-temperature radiation cooling coating with protective function, the coating is composed of the following raw materials: 5g alumina, 5g silicon oxide, 5g barium sulfate, 5g calcium carbonate, 2g silicon carbide, 2g zirconium oxide, 2g boron nitride, 33g polyurea silazane, 5g dispersant (AFCONA-4011), 5g wetting agent (AFCONA-5008), 3g defoamer (AFCONA-2791), 3g leveling agent (AFCONA-3030), and 25g di-n-butyl ether.

[0072] Its preparation method includes the following steps:

[0073] (1) Weigh according to the proportions;

[0074] (2) After uniformly dispersing di-n-butyl ether, polyurea silazane, wetting agent, dispersant, defoamer, and leveling agent, add alumina, silicon dioxide, barium sulfate, calcium carbonate, silicon carbide, zirconium oxide, and boron nitride. Use a high-speed disperser to stir at a speed of 400~800 r / min for 60~100 min, then use a sand mill or ball mill to disperse and grind to a fineness of 10~20 μm. Finally, filter with a 100~200 mesh wire mesh to obtain the high-temperature radiation cooling coating, which should be sealed and stored.

[0075] (3) Use quartz stone or brown corundum with a particle size of 1~5μm to sandblast the substrate surface so that the surface cleanliness of the substrate meets the requirements of Sa 2.5~3.0.

[0076] ⑷In the condition that the ambient temperature is 15-30℃ and the relative humidity of air is less than 85%, the high-temperature radiation refrigeration coating with the protection function is obtained by spraying twice with 0.8 MPa compressed air and then curing at room temperature after spraying.

[0077] The performance indexes of the obtained coating are shown in Table 4.

[0078] Table 4

[0079]

Claims

1. A high-temperature radiative cooling coating with a shielding function, characterized in that: The coating is composed of the following raw materials in mass fraction: radiation refrigeration pigment 20-35 parts, protective filler 4-6 parts, binder 20-40 parts, dispersant 3-5 parts, wetting agent 3-5 parts, defoaming agent 1-3 parts, leveling agent 1-3 parts, and di-n-butyl ether 15-25 parts; the thickness of the coating is 150-250 microns, the reflectivity is greater than 0.95, the emissivity is greater than 0.94, and the high-temperature resistance temperature reaches 800°C; the radiation refrigeration pigment is a combination of aluminum oxide, silicon oxide, barium sulfate, and calcium carbonate, and the particle size of each pigment is between 100 nanometers and 2 microns, the electron band gap is between 6 electron volts and 9 electron volts, and the refractive index is between 1.5 and 2.0; the binder is one or both of perhydro-polysilazane and polyurea-silazane; the protective filler is a combination of silicon carbide, zirconium oxide, and boron nitride, and the particle size of each filler is between 500 nanometers and 10 microns.

2. The high-emissivity radiant cooling coating with a protective function according to claim 1, characterized in that: The dispersant is one or both of AFCONA-4011, BYK-1165, and ANTI-TERRA-U 100.

3. The high-emissivity radiant cooling coating with a protective function according to claim 1, characterized in that: The wetting agent is one or both of AFCONA-5008, ANTI-TERRA-203, and BYKUMEN.

4. The high-emissivity radiant cooling coating with a protective function according to claim 1, characterized in that: The defoaming agent is one or both of BYK-070, AFCONA-2791, and BYK-1788.

5. The high-emissivity radiant cooling coating with a protective function according to claim 1, characterized in that: The leveling agent is one or both of CERATIX 8566, AFCONA-3030, and RHEOBYK-431.

6. A preparation method of a high-temperature radiation refrigeration coating with a protective function according to claim 1, comprising the following steps:

1. Weigh according to the ratio; 2. Mix and disperse the di-n-butyl ether, binder, wetting agent, dispersant, defoaming agent, and leveling agent uniformly, then add the radiation refrigeration pigment and protective filler, use a high-speed dispersing machine to stir at a speed of 400-800 r / min for 60-100 min, then use a sand mill or a ball mill to disperse and grind to a fineness of 10-20 μm, and then filter with a 100-200 mesh silk screen to obtain the high-temperature radiation refrigeration coating, which is sealed and stored; 3. Perform sandblasting treatment on the surface of the substrate using quartz stone or brown corundum with a particle size of 1-5 μm, so that the cleanliness of the substrate surface reaches the requirement of Sa 2.5-3.0 level; 4. Under the conditions of an environmental temperature of 15-30°C and an air relative humidity of less than 85%, use 0.8 MPa compressed air to spray twice, and then stand at room temperature for curing after spraying to obtain the high-temperature radiation refrigeration coating with a protective function.

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