TW202041363A - Radiative cooling material, method for manufacturing the same and application thereof - Google Patents

Abstract

The present disclosure provides a radiative cooling material, a method for manufacturing the same and application thereof. The radiative cooling material includes a first functional layer, an encapsulation layer and a protective layer. The structure of the radiative cooling material can be in a form of a film, a sheet or a coating. The radiative cooling material can achieve radiative cooling under direct sunlight during the day. By a thermal connection between the radiative cooling material and a surface of a heat dissipating body, the temperature of the heat dissipating body can be effectively reduced without consuming additional energy. It can be applied in fields of construction, photovoltaic components and systems, automotive, outdoor products, agriculture, animal husbandry, aerospace, cold chain transportation, outdoor cabinets, textiles, outdoor communications equipment, industrial equipment, utilities, cooling water systems, energy system, energy-saving equipment, and so on.

Description

Radiation cooling material and preparation method and application thereof

The invention relates to the field of materials science and technology, in particular to a radiation cooling material and a preparation method and application thereof.

At present, the trend of global warming is increasing, especially in low latitudes near the equator. Objects such as buildings and cars that are directly exposed to the sun outdoors have high internal temperatures and require a lot of energy to cool down.

Radiation cooling is an effective cooling method. Radiation cooling utilizes the basic physical principle that all surfaces of objects greater than absolute zero radiate energy in the form of electromagnetic waves. The outer space temperature outside the atmosphere is close to absolute zero. Therefore, the temperature of outer space close to absolute zero is a kind of "cold source". Infrared radiation can transmit heat from the earth's surface to outer space. A large number of documents indicate that the earth’s atmospheric window is transparent to infrared radiation (thermal radiation) in the 7-14 μm band.

When the existing radiation cooling materials are applied to occasions that require light transmission, it is difficult to balance the transmittance and the efficiency of radiation cooling.

The invention aims to provide a radiation cooling material and its preparation method and application.

The present invention provides a radiation cooling material. The radiation cooling material has a multiple layer structure and includes a first functional layer for radiation cooling, an encapsulation layer and a protective layer, and the first functional layer includes at least one polymer layer; The first functional layer has a transmittance of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8-13 μm/ The 7-13μm/8-14μm infrared band radiation has an emissivity of not less than 0.8; the encapsulation layer is arranged on the first surface of the first functional layer, and the protective layer is arranged on the opposite side to the first surface. The second surface; wherein the first surface refers to the surface on either side of the first functional layer, and the second surface is the surface on the other side opposite to the first surface.

In some embodiments, the radiation cooling material further includes a second functional layer disposed on the first surface of the first functional layer, between the first functional layer and the encapsulation layer between.

The present invention also provides a method for preparing the radiation cooling material, including: Prepare a first functional layer, which has a transmittance of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7 Radiation in the infrared band of -14μm/8-13μm/7-13μm/8-14μm has an emissivity not less than 0.8; Providing an encapsulation layer on the first surface of the first functional layer; A protective layer is provided on the second surface of the first functional layer. After the step of preparing the first functional layer and before the step of providing a protective layer on the second surface of the first functional layer, the method further includes: providing a second functional layer on the first surface of the first functional layer; The step of setting an encapsulation layer outside the second functional layer.

The present invention also provides an application method of the radiation cooling material as described above, including: arranging the radiation cooling material on a heat dissipation body, and thermally connecting the first functional layer and the heat dissipation body. In this application method, heat is transferred from the heat dissipation body to the radiation cooling material, and then the first functional layer in the radiation cooling material emits heat outward, thereby achieving radiation cooling.

The present invention also provides a composite material containing the radiation cooling material.

Optionally, the composite material is composed of the radiation cooling material and the substrate. The substrate can be metal, plastic, rubber, asphalt, glass, waterproof material, textile or woven fabric.

The radiation cooling material of the present invention has the following advantages:

The radiation cooling material of the present invention is based on the basic principle of radiation cooling. When the emissivity of the material in the infrared band (7-14μm/8-13μm/7-13μm/8-14μm) is not less than 0.8, it can be achieved Radiation under direct sunlight during the day cools down. In addition, based on the solar radiation having a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm with a transmittance of not less than 0.8, this material can achieve better transmittance and can be applied to the transmittance Areas with special requirements, such as the sun room, etc., to achieve the dual effects of light transmission and radiation cooling.

The radiation cooling material of the present invention, through thermal communication with the surface of the heat dissipating body, can emit the heat in the heat dissipating body through the atmospheric window in the form of infrared radiation, and can effectively reduce the temperature of the heat dissipating body without consuming additional energy. It is mainly used on the outer surface of the heat dissipation body that needs to be cooled. Its application fields are wide, including construction, photovoltaic modules, automobiles, outdoor supplies, agriculture, animal husbandry and aquaculture, aerospace, cold chain transportation, outdoor tanks, textiles, outdoor communications Equipment, industrial equipment, public electrical and electronic facilities, cooling water systems, energy systems (such as air conditioning/refrigeration/heating systems), energy-saving equipment and other outdoor equipment and facilities that urgently need cooling or heat dissipation. Radiation cooling materials can also be used to improve The efficiency of solar cells, traditional power plants and even water treatment. Further, a second functional layer is provided between the first functional layer and the encapsulation layer. Limit the reflectivity of the second functional layer in the solar radiation band (0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm) to 5~100%, and in the infrared band (7-14μm/8-13μm/ The emissivity of 7-13μm/8-14μm) is not less than 0.8, and this second functional layer can further reflect solar radiation. Therefore, the radiation cooling effect of the radiation cooling material is further improved. The radiation cooling material provides a radiation cooling power from 6W/m ² to 2640W/m ² at a working temperature of -170°C to 200°C, and further The radiation cooling material provides radiation cooling power from 388W/m ² to 2640W/m ² at a working temperature of 20°C to 200°C.

In the radiation cooling material of the present invention, the encapsulation layer is provided on the first surface of the first functional layer or the second functional layer for encapsulating the first functional layer or the second functional layer Protection to prevent oxidation, discoloration, corrosion, aging, etc. of the first functional layer and the second functional layer, while the packaging layer acts as an adhesive to fix the radiation cooling material on the surface of the heat dissipation body .

The protective layer is disposed on a second surface opposite to the first surface of the first functional layer, and is used to protect the first functional layer, the second functional layer and the encapsulation layer, especially when When the radiation cooling material is used outdoors, it needs to withstand the test of harsh climatic conditions. Due to the particularity of the material, the radiation cooling material with the protective layer has good weather resistance and excellent performance. The heat resistance, oxidation resistance, chemical resistance, abrasion resistance and corrosion resistance.

The protective layer and the encapsulation layer are respectively arranged on the outer surfaces of the first functional layer and the second functional layer to maintain the reflectance, transmittance, and transmittance of the first functional layer and the second functional layer. The stability of the emissivity plays a very important role.

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is a part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person with ordinary knowledge in the technical field of the present invention without making progressive work shall fall within the protection scope of the present invention.

The terms "first", "second", "third", etc. in the specification of the present invention and the appended patent application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes unlisted steps or units, or optionally also includes Other steps or units inherent to these processes, methods, products or equipment.

Detailed descriptions will be given below through specific embodiments.

Please refer to FIG. 1 and FIG. 2, an embodiment of the present invention provides a radiation cooling material.

The radiation cooling material has a multiple layer structure, including a first functional layer 10 for radiation cooling, an encapsulation layer 30 and a protective layer 40, and the first functional layer 10 includes at least one polymer layer. The first functional layer 10 has a transmittance of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 8-13 μm/7 Radiation in the infrared band of -13μm/8-14μm has an emissivity not lower than 0.8. The encapsulation layer 30 is disposed on the first surface of the first functional layer 10, and the protective layer 40 is disposed on the second surface opposite to the first surface. Preferably, the first functional layer 10 has a transmittance of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and has a transmittance of not less than 0.8 for a wavelength range of 8. Radiation in the infrared band of -13μm/8-14μm has an emissivity not lower than 0.8.

In some embodiments, the radiation cooling material may further include a second functional layer 20 disposed on the first surface of the first functional layer 10 and interposed between the first functional layer 10 And the encapsulation layer 30. Optionally, the second functional layer 20 has a transmittance of 0-95% for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a transmittance of a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm. The solar radiation of 2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm has a reflectivity of 5% to 100%. Preferably, the second functional layer 20 has a transmittance of 0-95% for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm, and a transmittance of 0-95% for a wavelength range of 0.25-2.5 μm/0.25 -3μm/0.3-2.5μm solar radiation has a reflectivity of 5% to 100%. More preferably, the second functional layer has a transmittance of 0-95% to solar radiation with a wavelength range of 0.4-0.7 μm/0.38-0.78 μm/0.4-0.76 μm, and a transmittance of 0.4-0.7 μm/0.38 to a wavelength range of 0.4-0.7 μm/0.38. -0.78μm/0.4-0.76μm solar radiation has a reflectivity of 5% to 100%.

Please refer to FIG. 1, in some embodiments, the first surface of the first functional layer 10 is provided with an encapsulation layer 30 and the second surface is provided with a protective layer 40, which constitutes a transmissive radiation cooling material. As shown in FIG. 1, the transmissive radiation cooling material includes a protective layer 40, a first functional layer 10, and an encapsulation layer 30 from top to bottom.

Please refer to FIG. 2, in other embodiments, a second functional layer 20 is provided on the first surface of the first functional layer 10, and an encapsulation layer 30 is provided on the outside of the second functional layer 20. The second surface is provided with a protective layer 40, which constitutes a reflective/semi-transparent radiation cooling material, and its absorption rate is very small, almost zero. As shown in FIG. 2, the reflective/semi-transmissive radiation cooling material includes a protective layer 40, a first functional layer 10, a second functional layer 20, and an encapsulation layer 30 from top to bottom. Optionally, the reflective radiation cooling material has a reflectivity of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm.

Optionally, this semi-transparent radiation cooling material has a transmittance of 1%-95% to solar radiation with a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm, which is more Preferably it is 5%-95%, more preferably 20%-70%.

The structure of the radiation cooling material may take the form of a film, a sheet or a coating, and the first functional layer 10 thereof may be used to be configured to communicate with the heat dissipation body to be cooled.

Wherein, the first functional layer includes at least a polymer layer. Optionally, the polymer layer includes a polymer and dielectric particles 50, and the dielectric particles are dispersed in the polymer. The first functional layer may include only a polymer, or may include a polymer and dielectric particles dispersed in the polymer. Here, the dielectric particles may be micron-sized particles.

Optionally, the polymer layer may include at least one first polymer layer and at least one second polymer layer arranged at intervals, that is, two polymer layers. Optionally, dielectric particles are dispersed in the polymer of any one of the two polymer layers, or dielectric particles are dispersed in the polymer of both polymer layers, or two polymers No dielectric particles may be provided in the polymer of the layer.

Optionally, the polymer layer may also include at least one first polymer layer, at least one second polymer layer, and at least one third polymer layer arranged at intervals, that is, three polymer layers. Optionally, any one of the three polymer layers or any two polymer layers has dielectric particles dispersed in the polymer, or the three polymer layers have dielectric particles dispersed in the polymer, or There may be no dielectric particles in the polymer of the three polymer layers.

When only the first polymer layer is included, it has a single-layer structure; when it includes at least two polymer layers, it has a multiple-layer structure. The components in each polymer layer in the plural layer structure may be the same or different from each other.

The first polymer layer, the second polymer layer, and the third polymer layer are represented by X, Y, and Z, respectively, and the structure of the polymer layer can be X, YX, YXY, YXYX, YXYXY, XYZ, YXZ, XZY, XYZXYZ etc. The Y layer and the Z layer can be set to have the functions of reflection, emission, absorption, transmission, weather resistance, stain resistance, hydrophobicity, increase the adhesion of the upper and lower layers, support or protection according to their positions in the layered structure.

Optionally, the difference in refractive index between the dielectric particles and the first polymer layer is less than 0.5. Preferably, the difference in refractive index between the dielectric particles and the first polymer layer is greater than 0.1 and less than 0.5.

Optionally, the diameter of the dielectric particles is between 1 μm and 200 μm, preferably, the diameter of the dielectric particles is between 1 μm and 200 μm, preferably between 5 μm and 30 μm, and more preferably It is 10μm±2μm.

Optionally, the configuration of the dielectric particles may be a sphere, an ellipsoid, a cube, a cuboid, a rod, a polyhedron, or other indefinite shapes.

Optionally, the mass ratio of the dielectric particles in the first functional layer is not more than 30%, for example, between 0.3% and 30%. Considering that the mass ratio of dielectric particles in the first functional layer is too small, it will affect the radiation cooling effect of the first functional layer, and the mass ratio of dielectric particles in the first functional layer is too large, which will affect the first function. The transmittance and film-forming properties of the layer, the mass of the dielectric particles in the first functional layer is preferably between 0.1% and 20%, more preferably, 0.3% to 5%.

Optionally, the volume ratio of the dielectric particles in the first functional layer is not more than 30%.

Optionally, the dielectric particles are organic particles or inorganic particles or a combination of organic particles and inorganic particles. Among them, the organic particles are at least one of acrylic resin particles, silicone resin particles, nylon resin particles, polystyrene resin particles, polyester resin particles, and polyurethane resin particles; inorganic particles are dioxide Silicon (SiO ₂ ), silicon carbide (SiC), aluminum hydroxide (Al(OH) ₃ ), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), barium sulfide (BaS), magnesium silicate (MgSiO ₃₎ ), at least one of barium sulfate (BaSO ₄ ), calcium carbonate (CaCO ₃ ) and titanium dioxide (TiO ₂ ). Considering the uniformity of the dispersion of inorganic particles in the polymer, the inorganic particles are preferably at least one of silicon dioxide (SiO ₂ ), titanium dioxide (TiO ₂ ), and magnesium silicate (MgSiO ₃ ).

Optionally, the polymer of the polymer layer is a thermoplastic polymer, a thermosetting polymer, or a combination of a thermoplastic polymer and a thermosetting polymer.

Among them, the thermoplastic polymer can use at least one of the following materials: poly-4-methyl-1-pentene (TPX), polyethylene terephthalate (PET), polyethylene naphthalate ( PEN), polyethylene terephthalate-1,4-cyclohexanedimethanol (PCT), polyethylene terephthalate-1,4-cyclohexanedimethanol (PETG and PCTG), poly Polyethylene phthalate-acetate (PCTA), polymethyl methacrylate (PMMA), polycarbonate (PC), acrylonitrile-styrene copolymer (SAN), acrylonitrile-butadiene-styrene Terpolymer (ABS), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), ethylene propylene diene rubber (EPDM), polyolefin elastomer (POE), polyamide (PA) , Ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), polyhydroxyethyl methacrylate (HEMA), polytetrafluoroethylene (PTFE), perfluoro (ethylene propylene) copolymer ( FEP), polyperfluoroalkoxy resin (PFA), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), thermoplastic polyurethane (TPU), polystyrene (PS).

Among them, the thermosetting polymer may use at least one of the following materials: polyether sulfide derivative copolymer (PES), diallyl diethylene glycol carbonate polymer (CR-39), two-component polyurethane (PU).

Further optionally, the material of the polymer layer may be a combination of at least one of PVC, PMMA, PC, PS, EVA, POE, PP, PE, TPX, PETG, PCTG, and PET.

Optionally, the color of the polymer layer may be transparent.

Further optionally, the material of the polymer layer may be poly-4-methyl-1-pentene (TPX), polyethylene terephthalate (PET), polyethylene naphthalate (PEN) , Poly 1,4-cyclohexanedimethanol terephthalate (PCT), polyethylene terephthalate-1,4-cyclohexanedimethanol (PETG and PCTG), polyterephthalate A mixture of at least one of ethylene glycol formate-acetate (PCTA), polymethyl methacrylate (PMMA), and polycarbonate (PC).

In terms of cost, process and structural stability, preferably, the layered structure of the polymer layer is YXY. This special layered structure gives the polymer layer performance stability, and the Y layer is also Produced the role of supporting and protecting the X layer. That is, the polymer layer includes a second polymer layer, a first polymer layer, and a second polymer layer from top to bottom. The material of the first polymer layer is PET/PEN, and the thickness of the first polymer layer is 50μm ~ 150μm, the material of the second polymer layer is PET/PEN, the thickness of the second polymer layer is 5μm ~ 20μm.

From the perspective of cost reduction and structural optimization, it is more preferable that the layered structure of the polymer layer may be YX, which includes a first polymer layer and a second polymer layer spaced apart from each other. The first polymer layer The material of the layer is PET/PEN, the thickness of the first polymer layer is 30 μm-60 μm, the material of the second polymer layer is PET/PEN, and the thickness of the second polymer layer is 5 μm-10 μm.

Optionally, the main component of the encapsulation layer includes at least one of polyurethane adhesives, acrylic adhesives, and epoxy resins, preferably polyurethane pressure-sensitive adhesives and acrylic pressure-sensitive adhesives, and more preferably double The component polyurethane pressure-sensitive adhesive and acrylic pressure-sensitive adhesive are used to encapsulate and protect the first functional layer or the second functional layer, and at the same time produce the effect of an adhesive. In other words, the encapsulation layer has the dual functions of protecting the second functional layer and/or the first functional layer and bonding.

The encapsulation layer may be arranged on the second functional layer or the functional layer by means of bonding or coating.

Optionally, the second functional layer includes at least one metal layer, or at least one ceramic material layer, or a combination of at least one metal layer and at least one ceramic material layer. The mixed arrangement of the metal layer and the ceramic material layer can simultaneously improve the reflectivity and prevent the metal layer from being oxidized.

Optionally, the material of the metal layer is selected from a metal layer of silver, aluminum, chromium, titanium, copper, or nickel, or a metal alloy layer including at least one element of silver, aluminum, chromium, titanium, copper, and nickel.

Optionally, the material of the ceramic material layer includes aluminum oxide, titanium oxide, silicon oxide, niobium oxide, zinc oxide, indium oxide, tin oxide, silicon nitride, titanium nitride, aluminum silicide, zinc sulfide, indium sulfide, At least one of tin sulfide, magnesium fluoride, and calcium fluoride.

In some embodiments, the structure of the second functional layer (from top to bottom) may include: silver, aluminum, silver + aluminum, silver + silicon, silver + titanium, aluminum + silicon, aluminum + titanium, silver + aluminum + titanium, Silver + aluminum + silicon, silver + silicon oxide, aluminum + silicon oxide, silicon oxide + silver + silicon, silicon oxide + aluminum + silicon, silicon oxide + silver, silicon oxide + aluminum, silicon oxide + silver + aluminum + silicon nitride , Silver + silicon aluminum alloy, silicon oxide + silver + silicon oxide + silver + silicon oxide, silicon oxide + silver + aluminum oxide + aluminum + silicon aluminum alloy, etc.

Optionally, for the reflective radiation cooling material, the thickness of the second functional layer can be adjusted above 1 nm, preferably between 5 nm and 500 nm, more preferably between 50 nm and 200 nm.

In a preferred solution, the second functional layer includes at least one metal layer, and the metal layer is made of aluminum, silver or titanium. Optionally, at least one surface of the metal layer is provided with at least one ceramic material layer. The ceramic material is preferably a metal-like oxide layer, such as silicon oxide, silicon nitride, or magnesium fluoride. The ceramic material layer can simultaneously produce the functions of improving reflectivity and weather resistance, wear resistance, oxidation and corrosion resistance.

Further, the protective layer includes an organic fluorine polymer (Organofluorine Polymer) layer, an organic silicon polymer (Resistant Silicone Polymers) layer, a fluorosilicone copolymer resin (Fluorosilicone Copolymer Resin) layer, and a polyethylene-nylon (PE/PA) composite layer. At least one of a film layer, an ethylene-vinyl alcohol copolymer (EVOH) layer, and a polypropylene-nylon (PP/PA) composite film layer. The protective layer material has excellent optical properties, weather resistance and barrier properties, and further has excellent transparency, heat resistance, oxidation resistance, chemical resistance, and corrosion resistance. The organic fluoropolymer layer includes at least one of the following materials: polytetrafluoroethylene (PTFE) layer, perfluoro (ethylene propylene) copolymer (FEP) layer, polyperfluoroalkoxy resin (PFA) layer, poly Chlorotrifluoroethylene (PCTFE) layer, ethylene-chlorotrifluoroethylene copolymer (ECTFE) layer, ethylene-tetrafluoroethylene copolymer (ETFE) layer, polyvinylidene fluoride (PVDF) layer and polyvinyl fluoride (PVF) layer . Taking into account the diversification of climatic conditions and the complexity of the place of use, materials with better heat resistance, oxidation resistance, chemical resistance and corrosion resistance are selected. Preferably, the material of the organic fluoropolymer layer is polytetrafluoroethylene At least one of ethylene (PTFE), polyvinylidene fluoride (PVDF), and ethylene-chlorotrifluoroethylene copolymer (ECTFE).

Optionally, the protective layer includes a polytetrafluoroethylene (PTFE) layer, a polyvinylidene fluoride (PVDF) layer, a polyvinyl fluoride (PVF) layer, an ethylene-tetrafluoroethylene copolymer (ETFE) layer, and an ethylene-trifluorochloroethylene layer. Ethylene copolymer (ECTFE) layer, polyethylene-nylon (PE/PA) composite film layer, ethylene-vinyl alcohol copolymer (PE/PA or EVOH) layer, polypropylene-nylon (PP/PA) composite film layer.

Optionally, the thickness of the encapsulation layer is between 1 μm and 500 μm, preferably between 5 μm and 100 μm.

Optionally, the thickness of the protective layer is between 1 μm and 300 μm, preferably 5 to 150 μm or 2 to 50 μm.

Optionally, the thickness of the first functional layer is between 5 μm and 500 μm, preferably between 10 μm and 200 μm.

When the radiation cooling material includes a second functional layer, the thickness of the second functional layer can be adjusted above 1 nm, for example, between 5 nm and 500 nm, according to different requirements for transparency of the radiation cooling material. According to the thickness and material of the second functional layer, the transmittance of the radiation cooling material to sunlight can be adjusted between 0-95%, forming a reflective/semi-transparent radiation cooling material.

Further, the radiation cooling material of the embodiment of the present invention can provide radiation cooling power from 6W/m ² to 2640W/m ² at an operating temperature of -170°C to 200°C.

Further, the radiation cooling material of the embodiment of the present invention can be combined with metal, plastic, rubber, asphalt, glass products, waterproof materials, textiles, braids and other materials to form composite materials.

As above, the embodiment of the present invention discloses a radiation cooling material, which can exist in the form of a thin film, that is, a radiation cooling film; it can also exist in the form of a sheet or a coating.

According to different working methods, the radiation cooling material can be divided into a reflective radiation cooling film, a transmissive radiation cooling film and a semi-transparent radiation cooling film. The following are further instructions:

1.1 Reflective radiation cooling film

The reflective radiation cooling film has the functions of reflection and radiation cooling at the same time. The reflective radiation cooling film includes a first functional layer and a second function for reflecting sunlight in contact with the first functional layer. The second functional layer includes a metal layer, a metal substrate and/or a ceramic material layer.

The first functional layer is characterized by having an infrared light emissivity of 0.8 to 1.0, and more preferably 0.9-1.0, for the infrared wavelength range of 7-14 μm/8-13 μm/7-13 μm/8-14 μm. The reflective radiation cooling film has a reflectivity of 0.8 to 1, preferably 0.9 to 1, for sunlight in the wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm.

1.2 Transmissive radiation cooling film

The transmissive radiation cooling film has the functions of both light transmission and radiation cooling, and the transmissive radiation cooling film includes a first functional layer.

The first functional layer is characterized by having an infrared light emissivity in the infrared wavelength range of 7-14 μm/8-13 μm/7-13 μm/8-14 μm, preferably 0.8 to 1.0, preferably 0.9-1.0.

The transmissive radiation cooling film has an absorption rate of 0 to 0.3 for the wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm.

1.3 Semi-transparent radiation cooling film

The semi-transmissive radiation cooling film has the functions of light transmission, reflection, and radiation cooling and cooling. The semi-transmissive radiation cooling film includes a first functional layer and a contact with the first functional layer for reflecting the sun. The second functional layer of light, the second functional layer includes a metal layer, a metal substrate and/or a ceramic material layer.

The first functional layer is characterized by having an infrared light emissivity in the infrared wavelength range of 7-14 μm/8-13 μm/7-13 μm/8-14 μm, preferably 0.8 to 1.0, preferably 0.9-1.0.

The transmissivity of the semi-permeable radiation cooling film to solar energy can be adjusted between 1%-95%, preferably 5%-95%, more preferably 20%-70%.

In the following, in combination with several specific embodiments, the relationship between the parameter changes and performance of different material layers in different types of radiation cooling materials will be specifically described.

The present invention provides an embodiment. The radiation cooling material includes a first functional layer, an encapsulation layer and a protective layer. The encapsulation layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. The first functional layer includes a polymer layer. In this embodiment, the material of the first functional layer is PET, the thickness is 150 μm, the dielectric particles are SiO ₂ , and the diameter of the dielectric particles is 6 μm. The material of the encapsulation layer is two-component polyurethane pressure-sensitive adhesive; the material of the protective layer is polyvinylidene fluoride (PVDF). FIG. 4 is a diagram showing the relationship between wavelength and emissivity in the first functional layer containing dielectric particles with different mass ratios in this embodiment. When the mass ratio of SiO ₂ in the first functional layer is 2%, 4%, 6%, and 8%, the relationship between wavelength and emissivity in the first functional layer with different mass ratios of SiO ₂ is shown in Figure 4. It can be seen from Fig. 4 that the first functional layer containing SiO _{2 has} a higher mass ratio of SiO ₂ with an increase in the infrared emissivity of 7-14 μm, but there is no significant absorption effect in the solar spectrum. Please refer to FIG. 5, which is a graph of the relationship between wavelength and reflectance and transmittance in the first functional layer in this embodiment (the mass ratio of dielectric particles SiO ₂ in the first functional layer is 4%). It can be seen from Figure 5 that the average transmittance of the first functional layer at 300~2500nm is about 90%, and the average reflectance is about 10%, and there is no significant absorption effect in the solar spectrum. At this time, in this embodiment, the material in which the dielectric particles SiO ₂ occupies a mass ratio of 4% in the first functional layer is defined as the transmissive radiation cooling material A.

The present invention also provides an embodiment. The radiation cooling material includes a first functional layer, a second functional layer, an encapsulation layer and a protective layer. The second functional layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. The packaging layer is disposed on the second functional layer. The first functional layer includes a polymer layer. In this embodiment, the material of the first functional layer is PET, the thickness is 150 μm, the dielectric particles are SiO ₂ , the diameter of the dielectric particles is 6 μm, and the mass ratio of the dielectric particles SiO ₂ in the first functional layer Is 4%. The material of the encapsulation layer is acrylic pressure-sensitive adhesive; the material of the protective layer is fluorosilicone copolymer resin. Please refer to FIG. 6, which is a graph of the relationship between wavelength and reflectivity in the second functional layer of different thicknesses in this embodiment. The structure of the second functional layer (from top to bottom) is aluminum + silicon oxide, and the thickness ratio of the aluminum layer to the silicon oxide layer is 1:1. When the thickness of the second functional layer is 30nm, 50nm, 80nm, At 100nm and 150nm, the graph of the relationship between wavelength and reflectivity in the second functional layer is shown in FIG. 6, the reflectivity of the second functional layer at 300-2500nm increases as the thickness of the second functional layer increases. Please refer to FIG. 7, which is a graph of the relationship between wavelength and transmittance in the second functional layer of different thicknesses in this embodiment. When the thickness of the second functional layer is 30nm and 50nm, the graph of the relationship between wavelength and transmittance in the second functional layer is shown in Figure 7. The transmittance of the second functional layer at 300~2500nm increases with the thickness of the second functional layer. Increase and decrease. When the thickness of the second functional layer is 30nm and 50nm, since its transmittance is above 5%, it is defined as a semi-transmissive radiation cooling material. The thickness of the second functional layer in this embodiment is 30 nm as the semi-transmissive radiation cooling material B. When the thickness of the selective functional layer is 80nm, 100nm, 150nm, the transmittance is less than 5%, so it is defined as a reflective radiation cooling material. The thickness of the second functional layer of this embodiment is 80 nm as the reflective radiation cooling material C.

The present invention also provides the following embodiments:

The present invention also provides another embodiment. The radiation cooling material includes a first functional layer, an encapsulation layer and a protective layer. The first functional layer includes two polymer layers. The encapsulation layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. In this embodiment, the material of the first functional layer is PEN, the thickness is 100 μm, the dielectric particles are organic silicon resin particles, and the diameter of the dielectric particles is 10 μm. The organic silicon resin particles of the dielectric particles are in the first functional layer. The mass ratio of 5% is 5%. The material of the encapsulation layer is a two-component polyurethane pressure-sensitive adhesive; the material of the protective layer is ethylene-vinyl alcohol copolymer (EVOH). The first functional layer has a transmittance of 92% to sunlight with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8-13 μm/ The infrared emissivity of the infrared band of 7-13μm/8-14μm is 0.94.

The present invention also provides another embodiment. The radiation cooling material includes a first functional layer, an encapsulation layer and a protective layer. The first functional layer includes two polymer layers. The encapsulation layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. In this embodiment, the material of the first functional layer is PC, the thickness is 80 μm, the dielectric particles are MgSiO ₃ , the diameter of the dielectric particles is 11 μm, and the mass ratio of the dielectric particles MgSiO ₃ in the first functional layer is Is 9%. The material of the encapsulation layer is a two-component polyurethane pressure sensitive adhesive; the material of the protective layer is an organic silicon polymer. The first functional layer has a transmittance of 90% to sunlight with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8-13 μm/ The infrared emissivity of the infrared band of 7-13 μm/8-14 μm is 0.91.

The present invention also provides another embodiment. The radiation cooling material includes a first functional layer, a second functional layer, an encapsulation layer and a protective layer. The second functional layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. The packaging layer is disposed on the second functional layer. The first functional layer includes two polymer layers. In this embodiment, the material of the first functional layer is PMMA, the thickness is 70μm, the dielectric particles are nylon-based resin particles, the diameter of the dielectric particles is 5μm, and the nylon-based resin particles are formed in the first functional layer. The quality ratio is 4%. The second functional layer is magnesium fluoride, the thickness of the second functional layer is 20 nm, the material of the encapsulation layer is epoxy resin; the material of the protective layer is a polyethylene-nylon (PE/PA) composite film. The radiation cooling material has a transmittance of 55% to sunlight with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8-13 μm/7 The emissivity of infrared light in the infrared band of -13μm/8-14μm is 0.93.

The present invention also provides another embodiment. The radiation cooling material includes a first functional layer, a second functional layer, an encapsulation layer and a protective layer. The second functional layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. The packaging layer is disposed on the second functional layer. The first functional layer includes two polymer layers. In this embodiment, the material of the first functional layer is PETG/PCTG, the thickness is 35μm, the dielectric particles are polystyrene resin particles, the diameter of the dielectric particles is 15μm, and the dielectric particles are polystyrene resin particles. The mass ratio in the first functional layer is 10%. The second functional layer is silicon nitride, the thickness of the second functional layer is 25nm, the material of the encapsulation layer is acrylic pressure sensitive adhesive; the material of the protective layer is polyethylene-nylon (PE/PA) composite membrane. The radiation cooling material has a transmittance of 40% to sunlight with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8-13 μm/7 The emissivity of infrared light in the infrared band of -13μm/8-14μm is 0.92.

Please refer to FIG. 3, an embodiment of the present invention also provides a method for preparing the radiation cooling material as described above. The radiation cooling material can be divided into a reflection type radiation cooling film, a semi-transmission type radiation cooling film and a transmission type radiation cooling film.

For transmissive radiation cooling films, the preparation method may include:

Prepare a first functional layer, the first functional layer includes at least one polymer layer, the first functional layer has a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm solar radiation The transmittance is not less than 0.8, and the emissivity is not less than 0.8 for radiation in the infrared band with the wavelength range of 7-14μm/8-13μm/7-13μm/8-14μm;

Providing an encapsulation layer on the first surface of the first functional layer;

A protective layer is provided on the second surface of the first functional layer.

For the semi-transparent radiation cooling film, the preparation method may include:

Prepare a first functional layer, the first functional layer includes at least one polymer layer, the first functional layer has a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm solar radiation The transmittance is not less than 0.8, and the emissivity is not less than 0.8 for radiation in the infrared band with the wavelength range of 7-14μm/8-13μm/7-13μm/8-14μm;

A second functional layer is provided on the first surface of the first functional layer, and an encapsulation layer is provided on the outside of the second functional layer;

A protective layer is provided on the second surface of the first functional layer.

That is to say, the step of providing the second functional layer can be selected or not selected according to the transparency requirements of the radiation cooling material. Without the second functional layer, the transparency of the material can be improved, and a transmission type radiation cooling material can be made. At this time, the transmission type radiation cooling material is required to have a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/ The transmittance of solar radiation of 0.3-3μm is not less than 0.8. Setting the second functional layer can improve the reflectivity of the material and make a reflective/semi-transparent radiation cooling material. At this time, for the reflective radiation cooling material, the material of the second functional layer is required to have a wavelength range of 0.25-2.5μm /0.25-3μm/0.3-2.5μm/0.3-3μm, the reflectivity of solar radiation is not less than 0.8. For semi-transparent radiation cooling materials, the material of the second functional layer is required to have a wavelength range of 0.25-2.5μm/0.25- The transmittance of solar radiation of 3 μm/0.3-2.5 μm/0.3-3 μm is 1%-95%, preferably 5%-95%, more preferably 20%-70%.

Optionally, preparing the first functional layer includes: dispersing dielectric particles in a polymer to form the polymer layer. Wherein, the dielectric particles may be inorganic particles or organic particles or a combination of both.

In some embodiments, preparing the first functional layer may specifically include:

Using single-layer extrusion, multiple-layer co-extrusion, melt-forming film or biaxial stretching, the polymer and dielectric particles are processed into a layered polymer layer as the first functional layer.

Among them, the preparation method of single-layer extrusion or multiple-layer co-extrusion or melt film formation can include: polymer raw material conveying→50~150℃ drying→220~280℃melting extrusion→casting→cooling (cold) The temperature of the roll is set to 20~150℃) → traction → winding.

The main steps of the melt film forming method include casting and film blowing procedures. The film blowing program may include an upward blowing cooling program or a downward blowing water cooling program.

The preparation method of biaxial stretching, the preparation process can include: raw material conveying→150~180℃ drying→250~280℃ melt extrusion→casting→cooling (cold roll temperature is set to 15~30℃)→longitudinal stretching ( Infrared heating temperature is 200~300℃, longitudinal stretch ratio is 1.5:1~4.5:1)→transverse stretch (setting temperature is 150~190℃, transverse stretch ratio is 1.5:1~4.5:1)→traction →It is made by rewinding.

The preparation method of biaxial stretching can also be carried out at the same time of longitudinal stretching and transverse stretching, which can be completed in one step.

Optionally, preparing the first functional layer further includes: single-layer or multiple-layer coating or solution film formation on the prepared polymer layer.

That is, single-layer extrusion or multiple-layer co-extrusion or melt-forming film or biaxial stretching + single-layer or multiple-layer coating or solution film-forming methods can be used to process the prepared polymer into a polymer layer as the first A functional layer substrate; then the polymer and the dielectric particles are mixed to form a polymer layer with dielectric particles dispersed therein; and then through single layer or multiple layer coating or solution film formation, coating On the substrate, it serves as the first functional layer. The first functional layer prepared in this way may include at least one polymer layer dispersed with dielectric particles.

The main steps of single-layer or multiple-layer coating or solution film formation can include: unwinding→surface treatment (surface treatment is mainly for dust removal and corona, which is used to maintain the cleanliness of the substrate and improve adhesion)→coating→drying→rewinding volume. The coating is to coat a mixture of polymer and dielectric particles on the substrate.

In some embodiments, disposing the second functional layer on the first surface of the first functional layer may specifically include: The second functional layer is deposited on the second surface of the first functional layer through a magnetron sputtering process, an evaporation coating process, an ion sputtering process, an electroplating process or an electron beam coating process.

The main steps of the magnetron sputtering program can include: vacuuming to a vacuum of 10 ^-2 ~10 ^-6 Pa → unwinding (unwinding speed is 1~500m/min) → filling gas (gas is argon, Nitrogen, oxygen or air)→ion cleaning→coating in vacuum chamber (coating power is 1~100KW)→winding.

The main steps of the evaporation coating procedure can include: vacuuming to a vacuum of 10 ^-2 ~10 ^-6 Pa → unwinding (unwinding speed is 1~500m/min) → filling gas (gas is argon, nitrogen, oxygen Or air) → ion cleaning → pre-evaporation → evaporation coating → winding.

The main steps of the ion sputtering program can include: vacuuming to a vacuum of 10 ^-2 ~10 ^-6 Pa→unwinding (unwinding speed is 1~500m/min)→gas filling (gas is argon, nitrogen, Oxygen or air)→ion cleaning→coating (coating power is 1~100KW)→winding.

In some embodiments, disposing the encapsulation layer outside the second functional layer may specifically include: disposing the encapsulation layer on the second functional layer or the first functional layer by bonding or coating. The encapsulation layer can encapsulate and protect the second functional layer and/or the functional layer, and can also produce an adhesive. The main component may include at least one of polyurethane pressure sensitive adhesive, acrylic pressure sensitive adhesive, epoxy resin and other materials.

In some embodiments, disposing an encapsulation layer on the first surface of the first functional layer may specifically include: preparing and forming an encapsulation layer on the second surface of the first functional layer by coating or bonding or co-extrusion of multiple layers. The protective layer.

Optionally, a polytetrafluoroethylene (PTFE) layer, a perfluoro (ethylene propylene) copolymer (FEP) layer, a polyperfluoroalkoxy resin (PFA) layer, and a polychlorotrifluoroethylene (PTFE) layer can be applied by coating. PCTFE) layer, ethylene-chlorotrifluoroethylene copolymer (ECTFE) layer, ethylene-tetrafluoroethylene copolymer (ETFE) layer, polyvinylidene fluoride (PVDF) layer, polyvinyl fluoride (PVF) layer, organic silicon polymer (Resistant Silicone Polymers) layer, Fluorosilicone Copolymer Resin layer, polyethylene-nylon (PE/PA) composite film layer, polyethylene-vinyl alcohol copolymer (EVOH) layer, polypropylene-nylon (PP) /PA) The coating solution of the composite film layer is coated on the second surface of the first functional layer to form a protective layer. The main steps can include: unwinding→surface treatment (surface treatment is mainly for dust removal and corona, which is used to keep the substrate clean Degree and improve adhesion)→coating→drying→winding.

Optionally, the polytetrafluoroethylene (PTFE) layer, the perfluoro(ethylene propylene) copolymer (FEP) layer, the polyperfluoroalkoxy resin (PFA) layer, and the polychlorotrifluoroethylene (PTFE) layer can be laminated (PCTFE) layer, ethylene-chlorotrifluoroethylene copolymer (ECTFE) layer, ethylene-tetrafluoroethylene copolymer (ETFE) layer, polyvinylidene fluoride (PVDF) layer, polyvinyl fluoride (PVF) layer, silicone polymer (Resistant Silicone Polymers) layer, Fluorosilicone Copolymer Resin layer, polyethylene-nylon (PE/PA) composite film layer, ethylene-vinyl alcohol copolymer (EVOH) layer or polypropylene-nylon (PP) /PA) The composite film layer is arranged on the second surface of the first functional layer to form the protective layer.

Optionally, a polytetrafluoroethylene (PTFE) layer, a perfluoro(ethylene propylene) copolymer (FEP) layer, a polyperfluoroalkoxy resin (PFA) layer, a polychlorotrifluoroethylene (PCTFE) layer, an ethylene -Trifluorochloroethylene copolymer (ECTFE) layer, ethylene-tetrafluoroethylene copolymer (ETFE) layer, polyvinylidene fluoride (PVDF) layer, polyvinyl fluoride (PVF) layer, organic silicon polymer (Resistant Silicone Polymers) Layer, Fluorosilicone Copolymer Resin layer, polyethylene-nylon (PE/PA) composite film layer, ethylene-vinyl alcohol copolymer (EVOH) layer or polypropylene-nylon (PP/PA) composite film layer , Together with the functional layer raw materials, are formed on the surface of the first functional layer through multiple layers of co-extrusion. The preparation process can include: raw material conveying→50~150℃drying→220~280℃melting extrusion→casting→cooling (cold roll The temperature is set to 20~150℃)→towing→rewinding.

An embodiment of the present invention also provides a composite material, which includes the radiation cooling material as described above, and is formed by a composite of the radiation cooling material and other materials.

Optionally, the composite material may be composited by the radiation cooling material and metal, plastic, rubber, asphalt, glass products, waterproof materials, textiles or braids. However, it needs to be understood that the metal, plastic, rubber, asphalt, glass products, waterproof material, textile or braid materials mentioned here are not exhaustive, and the composite material may also be a composite of the radiation cooling material and other materials.

Examples are as follows:

1) Combination with fabric

Combining radiation cooling materials and fabrics to prepare fabrics with radiation cooling and cooling functions, which are used in clothing, hats, curtains, canopy curtains, canopy curtains, tents, umbrellas, gloves, shoes, special clothing (high altitude, field operations) Special clothing) etc.

2) Combination with outdoor membrane materials

Combining radiation cooling materials with outdoor membrane materials, outdoor membrane materials can be high-strength flexible film materials to prepare composite membrane materials with radiation cooling and cooling functions, which can be used in membrane structure buildings, tents, parasols, etc., which can greatly reduce outdoor The temperature level in the facilities without air conditioning.

3) Combination with waterproof membrane

The radiation cooling material is combined with the waterproof membrane to prepare the waterproof membrane with radiation cooling and cooling function, which is applied to the roof, road surface, etc.

4) Combination with glass

Radiation cooling materials are combined with glass to prepare glass with radiation cooling and cooling functions, which are used in buildings, solar photovoltaic elements and systems, automobiles, etc.

5) Combination with metal

The radiation cooling material is combined with metal to prepare metal with radiation cooling and refrigeration functions, which can be used in cold collectors, roofs of shaded warehouses, water tanks, etc.

6) Application method combined with other products

Combining the radiant cooling material with other products requiring a cooling environment, the prepared product has a passive radiant cooling and cooling function, and the heat is directly transferred to the radiant cooling material, and the heat is radiated from the functional layer of the radiant cooling material.

The present invention also provides an application method of the radiation cooling material as described above for cooling. The method may include: arranging the first functional layer in the radiation cooling material to communicate with the heat dissipation body, especially in thermal communication with the surface of the heat dissipation body; transferring heat from the heat dissipation body to the radiation cooling material; The first functional layer in the radiation cooling material emits heat outward, in particular, the functional layer in the radiation cooling material radiates heat.

In this way, the heat radiated by the sun to the heat dissipating body or the heat in/on the heat dissipating body can be transferred to the radiation cooling material and then emitted out to achieve the effect of cooling.

The radiation cooling material can be set on the roof, windows or external walls of buildings, on a certain part of the photovoltaic element, on the roof, windows or body of automobiles, and on outdoor composite membrane materials such as membrane structure buildings, tents, etc. Parasols, outdoor products such as clothing, hats, gloves, shoes, special clothing/helmets (special clothing for high-altitude and field operations), etc., ordinary greenhouses, greenhouses or smart greenhouses used in agriculture, animal husbandry and aquaculture, etc., aviation and aerospace In the field, the outside of the heat dissipation surface of spacecraft instruments, the outside of structural parts exposed to the space environment, the outside of multiple layers of thermal insulation elements, etc., the outside of transportation tools used in cold chain transportation, and outdoor cabinets such as outdoor integrated cabinets, communication cabinets, power distribution cabinets, and electrical Cabinets, containers (including ordinary containers, containers that need to maintain constant temperature and cold-chain logistics), etc., storage tanks such as LNG storage tanks, windows and curtains, outdoor communication equipment such as outdoor cabinets, base stations or radio frequency units, etc., industrial Equipment such as industrial instruments and their cabinets, public facilities such as street lights and their radiator components, air conditioners such as outside the outdoor unit of air conditioners, cooling water systems, energy systems (such as air conditioning/refrigeration/heating systems), On energy-saving equipment installations, as well as outdoor equipment and facilities that require cooling or heat dissipation, radiation cooling materials can also be used to improve the efficiency of solar cells, traditional power plants and even water treatment.

As described above, the embodiments of the present invention provide a radiation cooling material, its preparation method, its composite material and its application method.

The radiation cooling material of the present invention, based on the basic principle of radiation cooling, has an emissivity higher than 0.8 in the infrared band (7-14μm/8-13μm/7-13μm/8-14μm), which can achieve radiation under direct sunlight during the day Cooling, and based on different application areas, in some applications where light transmission is required, the dual effects of light transmission and radiation cooling can be achieved by adjusting the transmittance of the radiation cooling material. Furthermore, the second functional layer is introduced to make the reflectance of this material in the solar radiation band (0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm) as high as possible, and in the infrared band (7-14μm) /8-13μm/7-13μm/8-14μm) emissivity is also as high as possible, so its radiation cooling effect is better.

The radiation cooling material of the present invention communicates with the surface of the heat dissipation main body, can emit the heat in the heat dissipation main body through the atmospheric window in the manner of infrared radiation, and can effectively reduce the temperature of the heat dissipation main body without consuming additional energy.

The radiation cooling material of the present invention has a wide range of applications, including construction, photovoltaic elements and systems, automobiles, outdoor supplies, agriculture, animal husbandry and aquaculture, aviation and aerospace, cold chain transportation, outdoor tanks, textile industry, outdoor communication equipment, Industrial equipment, public facilities, cooling water systems, energy systems (such as: air conditioning/refrigeration/heating systems combined), energy-saving equipment, etc., as well as outdoor equipment and facilities that require cooling or heat dissipation.

Further, the radiation cooling material can be applied to construction fields including industrial buildings, commercial buildings, residential buildings and public buildings.

Further, the radiation cooling material can be applied to industrial equipment, such as outdoor power distribution cabinets.

Further, the radiation cooling material can be applied to public facilities, such as street lamps and their radiators, toilet roof walls, and the road surface of stadiums.

Further, the radiation cooling material can be applied to outdoor equipment and facilities that require cooling or heat dissipation.

The present invention can be further understood through the following non-limiting examples.

Example 1: Building

In order to illustrate the cooling effect of the radiation-induced cooling material, the application of the radiation cooling material in a building will be taken as an example for description below.

Example 1-1

Place stainless steel display houses with internal length, width and height of 5m, 4m, and 3m in an open outdoor area in a certain area, and paste reflective radiation cooling material C (0.25~2.5) on the outside of the roof and four walls. μm reflectivity is 90.2%, 7~14μm emissivity is 92.2%). Here, the outdoor exhibition room pasted with reflective radiation cooling materials is defined as exhibition room A, and a thermocouple with a data recorder is used to measure and record 9 test points on the surface and inside of exhibition room A for 24 hours in a day The temperature changes inside.

Comparative example 1-2

Place the display house of the same size, material, structure and shape in a place consistent with the environment of display house A, but no radiation cooling materials are attached to the roof and four walls. Here, the display house without radiation cooling materials is defined as Show room B, use a thermocouple with a data recorder to measure and record the temperature changes of 9 test points on the surface and inside of show room B in the same day and time period as show room A. The distribution of test points in the display room A and the display room B is the same, as shown in Figure 8a and Figure 8b.

In Figures 8a and 8b, A1 is the test point of the lower surface temperature of the radiation cooling material at the middle position of the roof of the display house A, and A6 is the test point of the lower surface temperature of the radiation cooling material at the middle position of the outer surface of the east wall of the display house A Test point, A7 is the test point at the middle of the outer surface of the west wall of display house A and the test point of the lower surface temperature of the radiation cooling material, and A8 is the test point of the lower surface temperature of the lower surface of the radiation cooling material at the middle of the outer surface of the south wall of display house A , A9 is the test point of the lower surface temperature of the radiation cooling material at the middle of the outer surface of the north wall of the display room A, A2, A3, A4, A5 are the same vertical line perpendicular to the ground in the display room A, and different heights from the ground Test point for local air temperature. As shown in Figure 8b, the outdoor ambient temperature was also tested.

In Figure 8a and Figure 8b, B1, B6, B7, B8, and B9 are the middle position of the outer surface of the roof of the display house B, the middle position of the outer surface of the east wall, the middle position of the outer surface of the west wall, and the outside of the south wall. The temperature test points at the center of the surface and the center of the outer surface of the north wall. B2, B3, B4, and B5 are the test points of the air temperature at different heights from the ground on the same vertical line in the display room B. .

Please refer to Figure 8c, the temperature measurement point curve diagram of different positions on the surface of outdoor and display house A. It can be seen from Figure 8c that when the radiant cooling material is pasted on the outer surface of the display room A, the temperature of the outer surface of the display room A and the lower surface of the radiant cooling material (including the roof and the four directions of south, east, north and west) are lower than that of the outdoor environment. The highest drop is about 10°C.

It can be seen from Figure 8d that the indoor temperature at different points in the longitudinal direction of the display room A with the radiation cooling material is lower than the ambient temperature for 24 hours a day, and the maximum temperature drops by about 10℃ compared with the outdoor temperature; and with the increase of sunshine time , Gradually appearing that the closer to the roof, the lower the temperature, indicating that the radiation cooling material has an obvious passive radiation cooling effect.

It can be seen from Figure 8e that the temperature of the outer surface (including the roof and the four directions of southeast, southeast, northwest) of the display room B without radiation cooling materials is about 30°C higher than the outdoor temperature. It can be seen from Fig. 8c and Fig. 8e that the surface temperature of the display room A with the radiation cooling material is about 37°C lower than that of the display room B without the radiation cooling material.

It can be seen from Figure 8f that the display room B without the radiation cooling material has a larger temperature difference at different points in the longitudinal direction, and the closer to the roof of the display room, the higher the temperature and the more obvious temperature stratification.

Example 2: PV modules

The application of radiation cooling materials in the field of solar photovoltaics can solve the problem of excessively high working temperature of solar cells and improve the photoelectric conversion rate of solar photovoltaic elements.

In order to illustrate the cooling effect of radiation cooling materials, an example is given below.

Example 2-1

The transmissive radiation cooling material A (visible light transmittance 91.2%, 8-13μm infrared emissivity 93.1%) is set on the outer surface of the front glass of the photovoltaic element.

Comparative example 2-2

For the same photovoltaic element (to ensure that the I-V performance of the element is highly consistent), the outer surface of the front glass of the photovoltaic element is not treated in any way.

Test the temperature and output power of Example 2-1 and Comparative Example 2-2 in the same place at different times on the same day. The test element is a P-type single crystal silicon element. A typical day in August is selected for the test. The test site is at latitude 29 north. Near °, the temperature measurement point is placed in the middle position under the component backplane, and is not affected by light. The test data is shown in the following table:

Table 1-1 Comparison of temperature and output power between Example 2-1 and Comparative Example 2-2 Time/h Example 2-1/℃ Comparative example 2-2/℃ Difference/℃ Example 2-1/W Comparative example 2-2/W Difference/W 8:00 41.9 45.1 3.2 213.2 210.7 2.5 9:00 43.2 49.3 6.1 217.2 212.4 4.8 10:00 49.6 58.5 8.9 221.8 214.7 7.1 11:00 50.5 61.3 10.8 227.3 218.5 8.8 12:00 54.1 65.9 11.8 232.8 222.9 9.9 13:00 53.3 63.7 10.4 228.5 219.7 8.8 14:00 54.4 63.4 9.0 225.7 218.4 7.3 15:00 47.0 53.8 6.8 220.0 214.6 5.4 16:00 46.5 52.6 6.1 213.4 208.5 4.9 17:00 43.2 47.7 4.5 210.1 206.7 3.4 18:00 39.2 42.1 2.9 205.6 203.5 2.1

It can be seen from Table 1-1 that ① the components with radiant cooling materials are installed on the front, and the surface temperature of the backplane is significantly lower than the components without film; ② the output power of components with radiant cooling materials is higher than that of components without radiant cooling materials ③The difference between the output power of the component with radiation cooling material and the output power of the component without radiation cooling material reaches the maximum at noon, and the cooling effect of radiation cooling material is the best at noon; ④The radiation cooling material can be effective for a long time Reduce the surface temperature of the photovoltaic element, improve the photoelectric conversion rate, and increase the output power.

Example 3: Car

When radiation cooling materials are used in the automotive field, they have the following application methods: ① directly install the radiation cooling materials on the roof, sunroof, body or body glass of the car; ② combine the radiation cooling materials with the original The parts are combined to produce a part with radiation cooling function. For example, the skylight is made into a skylight with radiation cooling function; the glass is made into glass with radiation cooling function, etc.

Applying radiation cooling materials to automobiles has the following effects: 1. Significantly reduce the temperature of the roof, sunroof, body or body glass and other parts and the interior of the car, solve the problem of parking heating under sun exposure, thereby extending the life and safety of the car, and increasing the comfort of the car; 2. Reduce air conditioning energy consumption and extend the cruising range.

In order to illustrate the effect of radiation cooling material products, the following examples are given.

Example 3-1

Existing GAC Trumpchi GS8 car C has a transmissive radiation cooling material A attached to the outside of the glass (transparent radiation cooling material has a transmittance of 91.2%, and an average emissivity of 7~14μm is 92.2%), which is installed inside the car 5 temperature measurement points, temperature measurement point C1: front seat shoulder-to-shoulder high air temperature; temperature measurement point C2: middle seat shoulder-to-shoulder high air temperature; temperature measurement point C3: rear seat shoulder-to-shoulder high air temperature; temperature measurement point C4: front The temperature of the inner surface of the top of the car body; temperature measurement point C5: the temperature of the inner surface of the top of the middle car body. The temperature data is tested every 30 minutes, the test duration is 24h, and the test result is shown in Figure 9b.

Comparative example 3-2

Existing car D of the same model as car C, car D does not do any treatment on the glass, set the same temperature measurement points inside car D as inside car C, respectively D1, D2, D3, D4, D5, Car D is placed in a place consistent with the environment of car C, and the temperature data is tested every 30 minutes. The test duration is 24 hours. The test results are shown in Figure 9c.

Figure 9a is a schematic diagram of the temperature measurement points in cars C and D.

Figure 9b is the temperature curve of the temperature measurement point in the car C.

Figure 9c is the temperature curve diagram of the temperature measurement point in the car D.

Figure 9d is a graph of the temperature difference between the temperature measurement points in the same position in the cars C and D.

From Figures 9b, 9c, and 9d, we can get: At the same moment, the temperature of the five temperature measurement points of car C with the transmitted radiation refrigeration material is lower than the temperature of the corresponding five temperature measurement points of car D. Among them, the maximum temperature difference between temperature measurement points C1 and D1 can reach 9℃, the maximum temperature difference between temperature measurement points C2 and D2 can reach 10℃, the maximum temperature difference between temperature measurement points C3 and D3 can reach 9℃, and the maximum temperature difference between temperature measurement points C4 and D4 The maximum temperature difference can reach 18℃, and the maximum temperature difference between the temperature measuring points C5 and D5 can reach 13℃. It shows that the application of radiation cooling materials to automobile glass has a certain cooling effect on the interior space of the car, and the cooling effect is significant.

Conclusion: ① The application of radiant cooling materials to automobiles can greatly reduce the temperature of the roof, sunroof, body or body glass and other parts and the interior of the car, solve the problem of heating up under the sun exposure, thereby prolonging the life and safety of the car, and increasing the interior of the car ② The application of radiant refrigeration materials to automobiles can achieve a certain energy saving effect, reduce the energy consumption of automobile air conditioning, extend the cruising range, and reduce CO ₂ emissions.

Example 4: Curtain field

When radiant cooling technology is applied to the field of curtains, it has the following application methods: ①Attach a film or paint with radiant cooling function to the curtain; ②Combine radiant cooling technology with ordinary curtain raw materials on the market to prepare Out of curtains with radiation cooling effect.

In order to illustrate the effect of radiation cooling materials, an example is given below.

Example 4-1

Coat the reflective radiation cooling material C (reflectivity 90.2%, infrared emissivity 93.1% at 8~13μm) in the form of paint on the surface of the roller blind E, and install the roller blind E on the sunroof of the XXX model car 1 Inside, the coated surface faces the sunroof, and the temperature changes at the three temperature measuring points E1, E2, E3 in the car 1 with the roller blind E are tested.

The temperature change at the temperature measurement point.

Comparative example 4-2

Existing roller blind F with the same size, material and style as roller blind E, without any treatment on the surface of roller blind F, install roller blind F in the sunroof of car 2 of the same model as car 1, test and install roller blind F The temperature changes of F1, F2, F3, 3 temperature measurement points in the car 2.

Among them, the temperature measuring points E1, E2 and E3 are respectively: the inner surface of the car sunroof, the roller shutter surface (toward the sunroof), and the indoor air temperature measuring point; F1, F2, F3 are the same positions corresponding to E1, E2, and E3 3 temperature measurement points.

Fig. 10a is a schematic diagram of temperature measurement points in the car 1 with the roller blind E and the car 2 with the roller blind F.

Fig. 10b is a graph of temperature measurement points in the car 1 with roller blind E and the car 2 with roller blind F.

Fig. 10c is a graph of the temperature difference between the car 1 with the roller blind E and the car 2 with the roller blind F at the same location.

It can be seen from Figure 10c: ① The surface temperature of roller blind E coated with radiant refrigeration material can be reduced by up to 35℃ relative to the surface temperature of roller blind F. ② Roller blinds coated with radiant cooling materials can reduce the air temperature in car 1 by up to 15°C relative to the air temperature in car 2. ③ The temperature difference between car 1 and car 2 is proportional to the temperature inside the car. The higher the temperature, the greater the temperature difference.

in conclusion: ① It means that the visible light and near-infrared part of the energy reflected by the radiant cooling material can still effectively penetrate the white glass and be discharged to the external environment. Radiation refrigeration materials arranged inside the white glass can still exert considerable radiation refrigeration effects. ② The radiation cooling material coated on the roller blind has an obvious passive cooling effect.

Example 5: Agriculture, Animal Husbandry and Fishery Industry

Combining radiation cooling materials with agricultural, animal husbandry and aquaculture greenhouses can reduce the damage of high temperature in summer and tropical areas to crops, increase yield and quality, reduce the incidence of diseases caused by high temperature in livestock, increase the slaughter rate, and have high comprehensive economic benefits.

The principle is that the heat in the greenhouse is continuously transferred to the outer space (-270℃) through the atmospheric window in the form of infrared radiation through the radiation cooling material. By adjusting the microstructure design and size control in the metamaterial, the electromagnetic wave radiation wavelength is adjusted to increase the infrared emissivity and enhance the heat radiation efficiency.

The use of radiation cooling materials in agricultural greenhouses: ① It can ensure high transmittance in the visible light range to meet the sufficient sunlight required for the growth of the agriculture, animal husbandry and aquatic industries; ② Reduce the ultraviolet transmittance and reduce the harm of ultraviolet rays to the agriculture, animal husbandry and aquatic industries; ③ Reduce the temperature in the greenhouse and promote the growth of agriculture, animal husbandry and aquaculture.

In order to illustrate the effect of radiation cooling materials used in the agriculture, animal husbandry and aquaculture industries, the following is an example.

Example 5-1

Place the simulated greenhouse G in an open place, and stick the transmissive radiation cooling material A on the outer surface of the greenhouse G. The transmittance of the transparent radiation cooling material is 91.2%, and the average infrared emissivity of 8-10μm is 93.8%.

Select different temperature measurement points to test the internal temperature.

Comparative example 5-2

Place the greenhouse H with the same size, shape, material and structure as the simulated greenhouse G in a place consistent with the environment of the greenhouse G, and select the same temperature measurement point as that of the greenhouse G for comparison testing.

Figure 11a is a schematic diagram of temperature measurement points in greenhouses G and H.

Among them, G1, G2, and G3 are the inner surface of the glass on the south side of the simulated greenhouse G, the air at the center of the glass greenhouse, and the temperature measurement points on the top inner surface of the glass greenhouse; H1, H2, and H3 are the same as the simulated greenhouse G The temperature measurement point at the corresponding location;

Figure 11b is the temperature curve diagram of the temperature measurement points in the greenhouse G and H.

Figure 11c is a graph of the temperature difference between the temperature measurement points in the greenhouse G and H at the same position.

It can be seen from Figure 11b that ① the temperature inside the greenhouse G with the transmissive radiation cooling material is lower than the temperature in the greenhouse H without the transmissive radiation cooling material;

It can be seen from Figure 11c that the temperature difference between the experimental greenhouse and the comparative greenhouse is proportional to the temperature in the greenhouse. The higher the temperature in the greenhouse, the greater the temperature difference, and the maximum temperature difference can reach 7°C.

From the above conclusions, it can be seen that the greenhouse with the transmissive radiation cooling material has obvious passive cooling effect. The cooling effect is proportional to the temperature in the greenhouse. The higher the temperature in the greenhouse, the more obvious the cooling effect.

In the above-mentioned embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; those with ordinary knowledge in the technical field to which the present invention belongs should understand that they can still modify the technical solutions described in the above-mentioned embodiments, or modify Some of the technical features are equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

10: The first functional layer 20: Second functional layer 30: Encapsulation layer 40: protective layer 50: Dielectric particles S1: Step S2: Step S3: steps S4: steps A1: Test point A2: Test point A3: Test point A4: Test point A5: Test point A6: Test point A7: Test point A8: Test point A9: Test point B1: Test point B2: Test point B3: Test point B4: Test point B5: test point B6: Test point B7: Test point B8: Test point B9: Test point C1: Temperature measurement point C2: Temperature measurement point C3: Temperature measurement point C4: Temperature measurement point C5: Temperature measurement point D1: Temperature measurement point D2: Temperature measurement point D3: Temperature measurement point D4: Temperature measurement point D5: Temperature measurement point E1: Temperature measurement point E2: Temperature measurement point E3: Temperature measurement point F1: Temperature measurement point F2: Temperature measurement point F3: Temperature measurement point G1: Temperature measurement point G2: Temperature measurement point G3: Temperature measurement point H1: Temperature measurement point H2: Temperature measurement point H3: Temperature measurement point

In order to explain the technical solutions of the embodiments of the present invention more clearly, the following will briefly introduce the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those with ordinary knowledge in the technical field of the invention, other drawings can be obtained based on these drawings without making progressive work.

FIG. 1 is a schematic structural diagram of a transmissive radiation cooling material provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a reflective/semi-transparent radiation cooling material provided by an embodiment of the present invention;

3 is a schematic flow chart of a method for preparing a radiation cooling material provided by an embodiment of the present invention;

Figure 4 is a graph showing the relationship between wavelength and emissivity in the first functional layer containing dielectric particles with different mass ratios;

Fig. 5 is a graph of the relationship between wavelength and reflectance and transmittance in the first functional layer;

Fig. 6 is a graph of the relationship between wavelength and reflectivity in second functional layers of different thicknesses;

Fig. 7 is a graph of the relationship between wavelength and transmittance in second functional layers of different thicknesses;

Figure 8a is a diagram showing the temperature measurement points of houses A and B;

Figure 8b is another temperature measurement point diagram showing houses A and B;

Figure 8c is a graph of temperature measurement points at different positions on the surface of outdoor and display room A;

Figure 8d is a graph showing different longitudinal temperature measurement points of house A;

Figure 8e is a graph of temperature measurement points at different positions on the surface of outdoor and display room B;

Figure 8f is a graph showing different longitudinal temperature measurement points of house B;

Figure 9a is a schematic diagram of temperature measurement points in cars C and D;

Figure 9b is the temperature curve diagram of the temperature measurement point in the car C;

Figure 9c is a temperature curve diagram of the temperature measurement point in the car D;

Figure 9d is a curve diagram of the temperature difference between the temperature measurement points in the same position in cars C and D;

Figure 10a is a schematic diagram of temperature measurement points in the car 1 with the roller shutter E and the car 2 with the roller shutter F;

Figure 10b is a graph of temperature measurement points in the car 1 with the roller shutter E and the car 2 with the roller shutter F;

Figure 10c is a graph of the temperature difference between the car 1 with the roller shutter E and the car 2 with the roller shutter F at the same location;

Figure 11a is a schematic diagram of temperature measurement points in greenhouses G and H;

Figure 11b is the temperature curve diagram of the temperature measurement points in the greenhouse G and H;

Figure 11c is a graph of the temperature difference between the temperature measurement points in the greenhouse G and H at the same position.

no

10: The first functional layer

30: Encapsulation layer

40: protective layer

50: Dielectric particles

Claims (21)

A radiation cooling material, the improvement is that the radiation cooling material has a multiple layer structure, including a first functional layer for radiation cooling, an encapsulation layer and a protective layer, and the first functional layer includes at least one polymer layer; The first functional layer has a transmittance of not less than 0.8 for solar radiation with a wavelength range of 0.25-2.5 μm/0.25-3 μm/0.3-2.5 μm/0.3-3 μm, and a wavelength range of 7-14 μm/8- The 13μm/7-13μm/8-14μm infrared band radiation has an emissivity not lower than 0.8; The encapsulation layer is disposed on a first surface of the first functional layer, and the protective layer is disposed on a second surface opposite to the first surface. The radiation cooling material according to claim 1, wherein the radiation cooling material further comprises a second functional layer, and the second functional layer is disposed on the first surface of the first functional layer and is located between the first functional layer. Between the functional layer and the encapsulation layer; The second functional layer has a transmittance of 0-95% to solar radiation with a wavelength range of 0.25-2.5μm/0.25-3μm/0.3-2.5μm/0.3-3μm, and a wavelength range of 0.25-2.5μm/0.25- Solar radiation of 3μm/0.3-2.5μm/0.3-3μm has a reflectivity of 5% to 100%. The radiation cooling material according to claim 1, wherein the radiation cooling material further comprises a second functional layer, and the second functional layer is disposed on the first surface of the first functional layer and is located between the first functional layer. Between the functional layer and the encapsulation layer; The second functional layer has a transmittance of 0-95% to solar radiation with a wavelength range of 0.4-0.7μm/0.38-0.78μm/0.4-0.76μm, and a wavelength range of 0.4-0.7μm/0.38-0.78μm/ The solar radiation of 0.4-0.76μm has a reflectivity of 5-100%. The radiation cooling material according to claim 1 or 2 or 3, wherein: The polymer layer includes a polymer and dielectric particles, the dielectric particles are dispersed in the polymer, and the difference in refractive index between the dielectric particles and the polymer in the polymer layer is greater than 0.1 and less than 0.5 . The radiation cooling material according to claim 4, wherein: The diameter of the dielectric particles is between 1 μm and 200 μm; The mass ratio of the dielectric particles in the first functional layer is not more than 30%. The radiation cooling material according to claim 4, wherein: The dielectric particles are organic particles or inorganic particles or a combination of organic particles and inorganic particles; wherein, The organic particles are at least one of acrylic resin particles, silicone resin particles, nylon resin particles, polystyrene resin particles, polyester resin particles, and polyurethane resin particles; The inorganic particles are at least one of silicon dioxide, silicon carbide, aluminum hydroxide, aluminum oxide, zinc oxide, barium sulfide, magnesium silicate, barium sulfate, calcium carbonate, and titanium dioxide. The radiation cooling material according to claim 1 or 2 or 3, wherein the polymer layer is a thermoplastic polymer, or a thermosetting polymer, or a combination of a thermoplastic polymer and a thermosetting polymer, wherein, The thermoplastic polymer uses at least one of the following materials: poly-4-methyl-1-pentene, polyethylene terephthalate, polyethylene naphthalate, and polyethylene terephthalate 1,4- Cyclohexanedimethanol, polyethylene terephthalate-1,4-cyclohexanedimethanol, polyethylene terephthalate-acetate, polymethyl methacrylate, polycarbonate , Acrylonitrile styrene copolymer, acrylonitrile-butadiene-styrene terpolymer, polyvinyl chloride, polypropylene, polyethylene, ethylene propylene diene monomer, polyolefin elastomer, polyamide, ethylene- Vinyl acetate copolymer, ethylene-methyl acrylate copolymer, polyhydroxyethyl methacrylate, polytetrafluoroethylene, perfluoro(ethylene propylene) copolymer, polyperfluoroalkoxy resin, polychlorotrifluoroethylene, ethylene -Trifluorochloroethylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride and polyvinyl fluoride, thermoplastic polyurethane, polystyrene; The thermosetting polymer adopts at least one of the following materials: polyether sulfide derivative copolymer, bisallyl diethylene glycol carbonate polymer, and two-component polyurethane. The radiation cooling material according to claim 1 or 2 or 3, wherein: The protective layer includes at least one of an organic fluoropolymer layer, an organosilicon polymer layer, a fluorosilicon copolymer resin layer, a polyethylene-nylon composite film layer, an ethylene-vinyl alcohol copolymer layer, and a polypropylene-nylon composite film layer. One kind. The radiation cooling material according to claim 8, wherein: The organic fluoropolymer layer includes at least one of the following materials: a polytetrafluoroethylene layer, a perfluoro(ethylene propylene) copolymer layer, a polyperfluoroalkoxy resin layer, a polychlorotrifluoroethylene layer, an ethylene-trifluoroethylene layer Fluorochloroethylene copolymer layer, ethylene-tetrafluoroethylene copolymer layer, polyvinylidene fluoride layer and polyvinyl fluoride layer. The radiation cooling material according to claim 1 or 2 or 3, wherein the encapsulation layer includes at least one of polyurethane pressure sensitive adhesive, acrylic pressure sensitive adhesive, and epoxy resin. The radiation cooling material according to claim 2 or 3, wherein the second functional layer includes at least one metal layer, or at least one ceramic material layer, or a combination of at least one metal layer and at least one ceramic material layer. The radiation cooling material according to claim 11, wherein the metal layer is a metal layer of silver, aluminum, chromium, titanium, copper, or nickel, or includes at least one element of silver, aluminum, chromium, titanium, copper, and nickel的metal alloy layer; The material of the ceramic material layer includes aluminum oxide, titanium oxide, silicon oxide, niobium oxide, zinc oxide, indium oxide, tin oxide, silicon nitride, titanium nitride, aluminum silicide, zinc sulfide, indium sulfide, tin sulfide, fluorine At least one of magnesium fluoride and calcium fluoride. The radiation cooling material according to claim 1, wherein the thickness of the encapsulation layer is between 1 μm and 500 μm; the thickness of the protective layer is between 1 μm and 300 μm; the thickness of the first functional layer is between 5 μm and Between 500μm. The radiation cooling material according to claim 2, wherein the thickness of the second functional layer is between 1 nm and 500 nm. A method for preparing a radiation cooling material, which is improved in that it comprises: preparing a first functional layer, the first functional layer includes at least one polymer layer, and the wavelength range of the first functional layer is 0.25-2.5 μm/0.25- The solar radiation of 3μm/0.3-2.5μm/0.3-3μm has a transmittance of not less than 0.8, and the radiation of the infrared band with a wavelength range of 7-14μm/8-13μm/7-13μm/8-14μm is not less than 0.8 emissivity; Providing an encapsulation layer on the first surface of the first functional layer; and A protective layer is provided on the second surface of the first functional layer. The method according to claim 15, wherein after the step of preparing the first functional layer and before the step of providing a protective layer on the second surface of the first functional layer, the method further comprises: The step of arranging a second functional layer on the first surface of the layer, and arranging an encapsulation layer outside the second functional layer, specifically includes: The second functional layer is deposited on the first surface of the first functional layer through a magnetron sputtering procedure, an evaporation coating procedure, an ion sputtering procedure, an electroplating procedure or an electron beam coating procedure. The method according to claim 15, wherein, providing an encapsulation layer on the first surface of the first functional layer specifically includes: The encapsulation layer is arranged on the first functional layer by bonding or coating. The method according to claim 15, wherein providing a protective layer on the second surface of the first functional layer includes: The protective layer is arranged on the second surface of the first functional layer through coating, bonding or co-extrusion of multiple layers. An application method of a radiation cooling material according to any one of claims 1-14, wherein the improvement includes: arranging the radiation cooling material on a heat dissipation body, and making the first functional layer and the heat dissipation body Thermal connection. A composite material containing the radiation cooling material according to any one of claims 1-14, wherein the improvement is that the composite material is formed by a composite of the radiation cooling material and a substrate. The composite material according to claim 20, wherein the substrate is at least one of metal, plastic, rubber, asphalt, waterproof material, textile, and braid.

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