阅读说明：本技术 辐射制冷膜及其制品 (Radiation refrigeration film and product thereof ) 是由 徐绍禹 杨荣贵 钟松 王明辉 尹铮杰 杨慧慧 夏兆路 于 2021-02-04 设计创作，主要内容包括：本发明涉及一种辐射制冷膜及其制品,所述辐射制冷膜包括层叠设置的载体层、反射层和发射层,所述发射层为所述辐射制冷膜的入光侧,所述发射层的材料为含C-F键的聚合物,所述载体层的材料为含C-C键和/或C-O键的聚合物,所述载体层在120℃下放置30min后的横向方向的热收缩率≤2％、纵向方向的热收缩率≤3％,所述辐射制冷膜的厚度为50μm-170μm,其中,所述发射层的厚度占20％-90％。本发明的辐射制冷膜通过材料、结构和厚度的优化,在不需要添加辐射制冷颗粒的条件下就具有优异的大气窗口发射率,进而避免了辐射制冷颗粒的添加对辐射制冷膜的力学性能和耐候性的产生不利影响,使得辐射制冷膜具有更优异的力学性能和耐候性。(The invention relates to a radiation refrigeration film and a product thereof, wherein the radiation refrigeration film comprises a carrier layer, a reflecting layer and an emitting layer which are arranged in a stacking mode, the emitting layer is the light incident side of the radiation refrigeration film, the emitting layer is made of a polymer containing C-F bonds, the carrier layer is made of a polymer containing C-C bonds and/or C-O bonds, the carrier layer is placed at 120 ℃ for 30min, the heat shrinkage rate in the transverse direction is less than or equal to 2%, the heat shrinkage rate in the longitudinal direction is less than or equal to 3%, the thickness of the radiation refrigeration film is 50-170 mu m, and the thickness of the emitting layer accounts for 20-90%. The radiation refrigeration film has excellent atmospheric window emissivity under the condition of not adding radiation refrigeration particles through optimization of materials, structures and thicknesses, and further avoids adverse effects of the addition of the radiation refrigeration particles on the mechanical property and the weather resistance of the radiation refrigeration film, so that the radiation refrigeration film has more excellent mechanical property and weather resistance.)

1. The radiation refrigeration film is characterized by comprising a carrier layer, a reflecting layer and an emitting layer which are arranged in a stacking mode, wherein the emitting layer is the light incident side of the radiation refrigeration film, the emitting layer is made of a polymer containing C-F bonds, the carrier layer is made of a polymer containing C-C bonds and/or C-O bonds, the carrier layer is placed at 120 ℃ for 30min, the heat shrinkage rate in the transverse direction is less than or equal to 2%, the heat shrinkage rate in the longitudinal direction is less than or equal to 3%, the thickness of the radiation refrigeration film is 50-170 mu m, and the thickness of the emitting layer accounts for 20-90%.

2. The radiation-cooled film of claim 1, wherein the thickness of the radiation-cooled film is 55 μ ι η -170 μ ι η when the reflective layer is disposed between the carrier layer and the emissive layer.

3. A radiation-cooled film according to claim 2, wherein the ratio of the thickness of the emitter layer to the carrier layer is 1:2-8: 1.

4. The radiation refrigerating film as claimed in claim 3, wherein the thickness of the emitting layer is 25 μm to 120 μm.

5. The radiation chilling film of claim 1, wherein the thickness of said radiation chilling film is 50-125 μm when said carrier layer is disposed between said reflective layer and said emissive layer.

6. The radiant refrigeration film of claim 5 wherein the ratio of the thickness of the emitter layer to the carrier layer is from 3:10 to 22: 3.

7. The radiation-cooled film of claim 6, wherein the emissive layer has a thickness of 15 μm to 110 μm.

8. The radiation chilling film according to any one of claims 1-7, wherein the material of the emission layer comprises a fluorine-containing resin;

and/or the material of the carrier layer comprises at least one of polyester, polyurethane, polyamide and polycarbonate;

and/or the material of the reflecting layer comprises at least one of metal and alloy.

9. A radiation refrigerating film according to any of claims 1 to 7, wherein the surface energy of the surface of the carrier layer for carrying the reflective layer is greater than or equal to 40 mN/m.

10. The radiation chilling film according to any one of claims 1-7, wherein a polymer coating is further disposed between the carrier layer and the reflective layer, the polymer coating having a surface energy of greater than or equal to 40mN/m, the polymer coating having a thickness of 3nm to 200 nm.

11. A radiation-cooled film according to claim 10, wherein the absolute value of the difference in refractive index between the carrier layer and the polymer coating is greater than or equal to 0.05.

12. The radiation refrigerating film according to any one of claims 1 to 7, wherein the light incident surface of the emitting layer is provided with an embossed structure.

13. An article comprising a radiation-cooled film comprising a substrate and the radiation-cooled film of any of claims 1-12 disposed on the substrate, wherein the radiation-cooled film is attached to the substrate on a side thereof remote from the emissive layer by an adhesive layer.

14. The article comprising the radiant chilling film of claim 13, wherein the substrate comprises at least one of a metal substrate, a ceramic substrate, a semiconductor substrate, a plastic substrate, a glass substrate, a rubber substrate, an asphalt substrate, a cement substrate, a textile substrate.

15. The article comprising the radiant refrigerating film as claimed in claim 13, wherein the article is a radiant refrigerating waterproof roll, and the substrate is one of a petroleum asphalt paper base asphalt felt, a petroleum asphalt glass fiber base roll, an aluminum foil surface roll, an SBS modified asphalt waterproof roll, an APP modified asphalt waterproof roll, an ethylene propylene diene monomer roll, a polyvinyl chloride roll, a chlorinated polyethylene roll, a rubber blend roll and a TPO waterproof roll.

16. The article comprising a radiation-cooled film according to claim 13, wherein the article is a radiation-cooled metal sheet and the substrate is one of an aluminum alloy metal sheet, a zinc-plated metal sheet, a tin-plated metal sheet, a composite steel metal sheet, a color-coated steel metal sheet.

Technical Field

The invention relates to the technical field of new materials and energy conservation, in particular to a radiation refrigeration film and a product thereof.

Background

In the technical field of energy conservation, the radiation refrigeration film can transfer the surface heat of an object to the outer space in an infrared radiation mode of an atmospheric window (8-13 mu m) wave band, thereby achieving the purpose of cooling without energy consumption. As shown in fig. 1, the conventional radiation refrigeration film includes a first base layer 11, a first reflective layer 12, and a first emission coating 13, which are sequentially stacked, wherein the first emission coating 13 is formed by curing fluorine-containing resin, and first radiation refrigeration particles 14 are further distributed in the first emission coating 13. In the radiation refrigeration film, the first radiation refrigeration particles 14 are added in the first emission coating 13, so that on one hand, the mechanical property of the radiation refrigeration film can be reduced, and on the other hand, the orderliness of a fluorine-containing resin molecular chain in the first emission coating 13 can be destroyed, so that the permeability of water and oxygen is increased, and the weather resistance of the radiation refrigeration film is reduced.

In order to avoid the defects caused by the radiation refrigeration particles added into the fluorine-containing thin film coating, as shown in fig. 2, the another conventional radiation refrigeration film comprises a second base layer 21, a second reflection layer 22, a second emission layer 23 and a fluorine-containing thin film 24 which are sequentially stacked, wherein the second emission layer 23 comprises colloid and second radiation refrigeration particles 25 distributed in the colloid. In the radiation refrigeration film, the second radiation refrigeration particles 25 are not added in the fluorine-containing film 24, but are added in the colloid, so that the adhesive layer formed by the colloid and the second radiation refrigeration particles is used as the second emitting layer 23, and the fluorine-containing film 24 is mainly used for improving the weather resistance of the radiation refrigeration film. However, the addition of the second radiant refrigerant particles 25 to the colloid also results in an increase in the water and oxygen permeability of the colloid, thereby also reducing the weather resistance of the radiant refrigerant film; in addition, the second radiant refrigerating particles 25 added in the colloid reduce the cohesive force of the colloid, so that the integrity of the radiant refrigerating film is reduced, and meanwhile, the internal structure of the colloid is damaged, the cohesive force of the colloid is reduced, and the mechanical property of the radiant refrigerating film is reduced.

Disclosure of Invention

In view of the above, there is a need to provide a radiation refrigeration film and an article thereof having excellent refrigeration effect, weather resistance and mechanical properties.

The radiation refrigeration film comprises a carrier layer, a reflecting layer and an emitting layer which are arranged in a stacked mode, wherein the emitting layer is the light incidence side of the radiation refrigeration film, the emitting layer is made of a polymer containing C-F bonds, the carrier layer is made of a polymer containing C-C bonds and/or C-O bonds, the carrier layer is placed at 120 ℃ for 30min, the heat shrinkage rate in the transverse direction is not more than 2%, the heat shrinkage rate in the longitudinal direction is not more than 3%, the thickness of the radiation refrigeration film is 50-170 mu m, and the thickness of the emitting layer accounts for 20-90%.

In one embodiment, the thickness of the radiant refrigerating film is 55 μm to 170 μm when the reflective layer is disposed between the carrier layer and the emission layer.

In one embodiment, the thickness of the emitting layer and the carrier layer is 1:2-8: 1.

In one embodiment, the thickness of the emissive layer is 25 μm to 120 μm.

In one embodiment, the thickness of the radiation refrigerating film is 50 μm to 125 μm when the carrier layer is disposed between the reflection layer and the emission layer.

In one embodiment, the thickness of the emission layer and the carrier layer is 3:10-22: 3.

In one embodiment, the thickness of the emission layer is 15 μm to 110 μm.

In one embodiment, the material of the emissive layer comprises a fluorine-containing resin;

and/or the material of the carrier layer comprises at least one of polyester, polyurethane, polyamide and polycarbonate;

and/or the material of the reflecting layer comprises at least one of metal and alloy.

In one embodiment, the surface energy of the surface of the carrier layer for carrying the reflective layer is greater than or equal to 40 mN/m.

In one embodiment, a polymer coating is further arranged between the carrier layer and the reflecting layer, the surface energy of the polymer coating is more than or equal to 40mN/m, and the thickness of the polymer coating is 3nm-200 nm.

In one embodiment, the absolute value of the refractive index difference between the carrier layer and the polymer coating is greater than or equal to 0.05.

In one embodiment, the light incident surface of the emitting layer is provided with an embossed structure.

An article comprising a radiation-cooled film, the article comprising a substrate and the radiation-cooled film disposed on the substrate, wherein a side of the radiation-cooled film remote from the emissive layer is attached to the substrate by an adhesive layer.

In one embodiment, the substrate comprises at least one of a metal substrate, a ceramic substrate, a semiconductor substrate, a plastic substrate, a glass substrate, a rubber substrate, an asphalt substrate, a cement substrate, and a textile substrate.

In one of them embodiment, the goods is radiation refrigeration waterproofing membrane, the base member is one of petroleum asphalt tyre asphalt felt, the fine child coiled material of petroleum asphalt glass, aluminium foil face coiled material, SBS modified asphalt waterproofing membrane, APP modified asphalt waterproofing membrane, EPT coiled material, polyvinyl chloride coiled material, chlorinated polyethylene coiled material, rubber blend coiled material, TPO waterproofing membrane.

In one embodiment, the article is a radiation-cooled metal sheet and the substrate is one of an aluminum alloy metal sheet, a zinc-plated metal sheet, a tin-plated metal sheet, a composite steel metal sheet, and a color-coated steel metal sheet.

C-F bond has strong absorptivity in atmospheric window waveband of 8-13 mu m, and has strong absorptivity in waveband of 8-10 mu m, and C-C and C-O also have strong absorptivity in atmospheric window waveband of 8-13 mu m, especially have strong absorptivity in waveband of 8-9.5 mu m, so that the polymer containing C-F bond has excellent spectral selectivity, and the polymer containing C-C bond and/or C-O bond has excellent spectral selectivity. Meanwhile, the F atom has large electronegativity, the bond energy of the C-F bond is high and can reach 500KJ/mol, but in the optical band of sunlight, the optical band which damages organic matters is 280nm-780nm, the energy of the optical band does not reach the degree of damaging the C-F bond, the F atom polarizability is low, and the polymer containing the C-F bond can show high thermal stability and chemical inertness, so the polymer containing the C-F bond also has excellent weather resistance.

Therefore, in the radiation refrigeration film, the polymer containing C-F bonds is used as the material of the emission layer, the polymer containing C-C bonds and/or C-O bonds is used as the material of the carrier layer, the polymer containing C-C bonds and/or C-O bonds are matched with each other for use, meanwhile, the emission layer is used as the light incidence side of the radiation refrigeration film, the number of the C-F bonds, the C-C bonds and/or the C-O bonds in a unit area is optimized through the control of the thickness, and the heat absorption of a sunlight wave band is controlled, so that the radiation refrigeration film has excellent atmospheric window emissivity under the condition that radiation refrigeration particles do not need to be added, the adverse influence of the addition of the radiation refrigeration particles on the mechanical property and the weather resistance of the radiation refrigeration film is avoided, and the radiation refrigeration film has more excellent mechanical property and weather resistance.

Drawings

FIG. 1 is a schematic diagram of a conventional radiation-cooled membrane;

FIG. 2 is a schematic diagram of another conventional radiant cooling membrane;

FIG. 3 is a schematic structural view of a radiation refrigerating film according to a first embodiment of the present invention;

FIG. 4 is a schematic structural view of a radiation refrigerating film according to a second embodiment of the present invention;

FIG. 5 is a schematic structural view of a radiation refrigerating film according to a third embodiment of the present invention;

FIG. 6 is a model house of an engineering application experiment;

FIG. 7 is a graph showing the cooling effect of the experiment shown in FIG. 6.

In the figure: 11. a first base layer; 12. a first reflective layer; 13. a first emissive coating; 14. a first radiant refrigerant particle; 21. a second base layer; 22. a second reflective layer; 23. a second emission layer; 24. a fluorine-containing film; 25. a second radiant refrigerant particle; 31. a carrier layer; 32. a reflective layer; 33. an emission layer; 34. an adhesive layer; 35. a polymer coating; 36. and (3) embossing structure.

Detailed Description

The radiation refrigeration film and the product thereof provided by the invention will be further explained below.

As shown in fig. 3, a radiation refrigerating film of a first embodiment is provided, which includes a carrier layer 31, a reflective layer 32, and an emission layer 33, which are stacked.

Wherein, the material of the emitting layer 33 is a polymer containing C-F bond, the C-F bond has strong absorptivity in the atmospheric window wave band of 8 μm-13 μm and has strong absorption peak in the wave band of 8 μm-13 μm, so the polymer containing C-F bond has excellent spectral selectivity, and when used as the material of the emitting layer 33, the emitting layer 33 can have excellent atmospheric window emissivity. Meanwhile, since the F atom has large electronegativity, the bond energy of the C-F bond is high and can reach 500KJ/mol, but the optical band which is destroyed to organic matters in the optical band of sunlight is 280nm-780nm, the energy of the optical band does not reach the degree of destroying the C-F bond, the polarizability of the F atom is low, and the polymer containing the C-F bond can show high thermal stability and chemical inertness, the polymer containing the C-F bond also has excellent weather resistance, and when the polymer is used as the material of the emission layer 33, the emission layer 33 can have excellent weather resistance.

The material of the carrier layer 31 is a polymer containing C-C bonds and/or C-O bonds, and C-C and C-O have strong absorptivity in an atmospheric window of 8-13 mu m, especially have strong absorption peaks in a wave band of 8-9.5 mu m, so that the polymer containing C-C bonds and/or C-O bonds also has excellent spectral selectivity, and when the material is used as the material of the carrier layer 31, the material can assist in improving the atmospheric window emissivity of the radiation refrigeration film.

In the radiation refrigeration film, the emissivity y is a-be (-x/k), where a, b, and k are constants determined according to different materials, x is a thickness, and e is a natural index, and it can be known from the formula of the emissivity that as the thicknesses of the emission layer 33 and the carrier layer 31 increase, the number of C-F bonds, C-C bonds, and/or C-O bonds per unit area increases, and the atmospheric window emissivity of the radiation refrigeration film also increases, but the increase in the thickness not only increases the cost of the radiation refrigeration film, but also increases the heat absorption of the emission layer 33 and the carrier layer 31 to the solar wavelength band, and when the thickness reaches a limit, the cooling effect of the radiation refrigeration film is rather reduced.

Therefore, the thickness of the radiation refrigeration film is controlled to be 50-170 μm, wherein the thickness of the emission layer 33 accounts for 20-90%, so that the number of C-F bonds, C-C bonds and/or C-O bonds in a unit area is optimized through the thickness control, the heat absorption of a solar wave band is controlled, the heat absorption rate of the emission layer 33 and the carrier layer 31 is less than or equal to 20%, the radiation refrigeration film has excellent atmospheric window emissivity under the condition that radiation refrigeration particles do not need to be added, the adverse influence of the addition of the radiation refrigeration particles on the mechanical property and the weather resistance of the radiation refrigeration film is avoided, and the reflection type radiation refrigeration particles have more excellent mechanical property and weather resistance.

In this embodiment, the reflective layer 32 is disposed between the carrier layer 31 and the emission layer 33, and when the radiation refrigerating film is used on a substrate, the emission layer 33 is a light incident side of the radiation refrigerating film, so that the radiation refrigerating film has excellent weather resistance.

At the moment, after the sunlight reaches the radiation refrigeration film, most of the sunlight is reflected back to the atmosphere by the reflection layer 32, so that the sunlight wave band is blocked and rarely enters the matrix, then the heat in the matrix is converted into infrared rays with the size of 8 mu m-13 mu m by the emission layer 33, the infrared rays radiate through an atmosphere window with the size of 8 mu m-13 mu m, and the infrared rays directly enter an outer space cold source because the atmosphere in the atmosphere window with the size of 8 mu m-13 mu m has no absorption basically, so that the radiation refrigeration effect is realized, and the temperature of the matrix is reduced.

In this embodiment, since the carrier layer 31 is separated from the emission layer 33 by the reflection layer 32, the carrier layer 31 can protect the reflection layer 32, but the effect of auxiliary emission is reduced accordingly, and therefore, in an embodiment, the thickness of the radiation refrigerating film is further preferably 55 μm to 170 μm. In view of the heat shrinkability of the radiation refrigeration film, wherein the thickness of the emission layer 33 and the carrier layer 31 is 1:2 to 8:1, preferably 1:1 to 3.75:1, the ratio of the thicknesses of the emission layer 33 and the reflection layer 32 is 50:1 to 12000:1, preferably 80:1 to 4000:1, and the thickness of the emission layer 33 is 25 μm to 120 μm, more preferably 40 μm to 75 μm. Thus, the number of C-F bonds, C-C bonds and/or C-O bonds per unit area is further optimized by controlling the thickness, and the heat absorption in the solar wavelength band is controlled, so that the heat absorption rate of the emitting layer 33 and the carrier layer 31 is further 15% or less, and further 10% or less.

In the radiation refrigeration film of this embodiment, the material of the reflective layer 32 includes at least one of metal and alloy, specifically, at least one of silver, silver alloy, aluminum alloy, titanium and titanium alloy. In an embodiment, the reflective layer 32 includes a plurality of sub-reflective layers to reduce the internal stress of the reflective layer 32, and meanwhile, when the materials of the sub-reflective layers are different, for example, the reflective layer 32 includes a silver reflective layer and an aluminum reflective layer which are stacked, or further includes a titanium reflective layer which is stacked, through the coordination of the plurality of sub-reflective layers, the technical defect and the effect defect when the respective sub-reflective layer exists alone can be made up, the reflectivity of the reflective layer 32 to the sunlight full-wave band can be improved, and further, the reflectivity of the radiation refrigeration film can be improved, and meanwhile, the damage of ultraviolet light to the radiation refrigeration film can be reduced, and the service life of the radiation refrigeration film can be prolonged. Therefore, in the embodiment, through optimization of materials, structures and thicknesses, the emissivity of the radiation refrigerating film in an atmospheric window waveband can reach 85%, further 90% and further 95%; the reflectivity of the solar water heater to the whole wave band of sunlight can reach 82%, further can reach 87%, further can reach 92%, and the solar water heater has an excellent refrigeration effect.

In view of the mechanical properties of the radiation refrigerating film, such as tensile strength, in one embodiment, the polymer containing C-C bonds and/or C-O bonds is preferably at least one of polyester, polyurethane, polyamide, and polycarbonate, wherein the polyester includes at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), poly (ethylene terephthalate-1, 4-cyclohexadienedimethylene terephthalate) (PETG).

Because the surface energy of the reflective layer 32 made of metal or alloy material is high, the reflective layer 32 can be directly attached to the surface of the carrier layer 31, or directly deposited on the surface of the carrier layer 31 by sputtering, evaporation, or the like.

In order to ensure the flatness of the reflecting layer, the cooling effect of the radiation refrigerating film and the service life, the heat shrinkage rate of the carrier layer 31 in the Transverse Direction (TD) is less than or equal to 2% and the heat shrinkage rate in the longitudinal direction (MD) is less than or equal to 3% after being placed at 120 ℃ for 30 min.

In view of containing C — F bond in the fluorine-containing resin and easy availability, in one embodiment, the material of the emission layer 33 is preferably fluorine-containing resin, and specifically includes at least one of ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polyvinyl formal (PVF), Polychlorotrifluoroethylene (PCTFE), fluoroolefin-vinyl ether copolymer (FEVE), Polytetrafluoroethylene (PTFE), ethylene chlorotrifluoroethylene copolymer (ECTFE), fluoroethylene propylene copolymer (FEP), meltable Polytetrafluoroethylene (PFA), and further, the fluorine-containing resin specifically includes at least one of ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polyvinyl formal (PVF) fluoroolefin-vinyl ether copolymer (FEVE), Polytetrafluoroethylene (PTFE), and fluoroethylene propylene copolymer (FEP).

The surface energy of the fluorine-containing resin is low, so that the emission layer 33 may be formed by directly curing a coating of the fluorine-containing resin on the surface of the reflection layer 32, and the coating of the fluorine-containing resin may be water-based or oil-based.

When the emitting layer 33 is a fluorine-containing thin film, as shown in fig. 4, the radiation refrigeration film of the second embodiment is provided, in the radiation refrigeration film of the embodiment, the fluorine-containing resin thin film is fixedly adhered to the reflecting layer 32 through an adhesive layer 34, wherein the material of the adhesive layer 34 includes at least one of polyurethane glue and acrylic glue with good weather resistance, and the thickness of the adhesive layer 34 is 0.5 μm to 20 μm.

In addition, when the material of the carrier layer 31 is selected from polyester, polyurethane, polyamide, polycarbonate, its surface energy is low, before the reflective layer 32 is deposited or adhered, the surface of the carrier layer 31 may be treated by a plasma method, a corona method or the like, to increase the surface energy to 40mN/m or more, further to 42mN/m or more, or 45mN/m or more, or 50mN/m or more, or 55mN/m or more, alternatively, a polymer coating 35 is provided on the carrier layer 31, the surface energy of the polymer coating 35 being 40mN/m or more, further 42mN/m or more, or 45mN/m or more, or 50mN/m or more, or 55mN/m or more, thereby, the adhesive force of the carrier layer 31 and the reflecting layer 32 is greatly improved, and the peeling strength of the whole radiation refrigerating film is further improved.

When a polymer coating 35 is provided, preferably having a thickness of 3nm to 200nm, the absolute value of the refractive index difference between the carrier layer 31 and the polymer coating 35 is greater than or equal to 0.05 to assist in increasing the reflectivity of the radiation-cooled film.

In one embodiment, the material of the polymer coating 35 includes at least one of epoxy acrylic polymer, urethane acrylate, and polyester acrylate.

As shown in fig. 4, in the radiation refrigeration film of the present invention, the light incident surface of the emitting layer 33 may further be provided with an embossed structure 36, the embossed structure is one or more of a square structure, a circular structure, a diamond structure and a twill pattern structure, and the depth is 0.5 μm to 2.5 μm, so that the surface gloss of the radiation refrigeration film can be reduced by the embossed structure 36, and the light reflected by the mirror surface is reduced, thereby reducing the light pollution of the radiation refrigeration film in the application process, and being suitable for the field such as an airport and the like having special requirements for light pollution.

As shown in fig. 5, a radiation refrigerating film according to a third embodiment of the present invention is provided, in which the carrier layer 31 is disposed between the reflective layer 32 and the emission layer 33. At this time, after the sunlight reaches the radiation refrigeration film, the reflection layer 32 reflects most of the sunlight back to the atmosphere, so that the sunlight wave band is blocked and rarely enters the substrate; then the emitting layer 33 converts the heat in the matrix into infrared rays with the size of 8-13 μm, the infrared rays radiate through an atmospheric window with the size of 8-13 μm, the atmosphere in the atmospheric window with the size of 8-13 μm basically has no absorption, and the infrared rays directly enter an outer space cold source, so that the radiation refrigeration effect is realized, and the cooling of the matrix is realized.

In this embodiment, the carrier layer 31 is located between the emission layer 33 and the reflection layer 32, so that the carrier layer 31 can better assist the emission layer 33 to radiate, and therefore, in an embodiment, the thickness of the radiation refrigerating film is further preferably 50 μm to 125 μm. Meanwhile, in consideration of the heat shrinkability of the radiation refrigeration film, the thickness of the emission layer 33 to the carrier layer 31 is 3:10 to 22:3, preferably 1:5 to 20:3, the ratio of the thickness of the emission layer 33 to the thickness of the reflection layer 32 is 30:1 to 110000:1, preferably 25:1 to 100000:1, and the thickness of the emission layer 33 is 15 μm to 110 μm, and more preferably 40 μm to 75 μm. Thus, the number of C-F bonds, C-C bonds and/or C-O bonds per unit area is further optimized by controlling the thickness, and the heat absorption in the solar wavelength band is controlled, so that the heat absorption rate of the emitting layer 33 and the carrier layer 31 is further 15% or less, and further 10% or less.

Therefore, in this embodiment, through optimization of materials, structures and thicknesses, the emissivity of the radiation refrigeration film in the atmospheric window band can reach 87%, further, 92%, and further, 97%; the reflectivity of the sunlight in all bands can reach 80 percent; further, 85% can be achieved, and further 90% can be achieved, so that the refrigerating effect is excellent.

It is understood that, in this embodiment, the reflective layer 32 may be directly attached to the surface of the carrier layer 31, or directly deposited on the surface of the carrier layer 31 by sputtering, evaporation, or the like, and before the reflective layer 32 is deposited or attached, the surface of the carrier layer 31 may be treated by plasma method, corona method, or the like to improve the surface energy thereof, or a polymer coating 35 is disposed on the carrier layer 31 to improve the adhesion between the carrier layer 31 and the reflective layer 32, thereby improving the peel strength of the entire radiation refrigeration film.

In addition, the emitting layer 33 may be formed by directly curing a coating material containing fluorine resin on the surface of the carrier layer 31, the coating material containing fluorine resin may be water-based or oil-based, or when the emitting layer 33 is a fluorine-containing film, the fluorine-containing film is fixedly bonded to the carrier layer 31 by an adhesive layer 34.

Therefore, the radiation refrigeration film provided by the invention has excellent atmospheric window emissivity under the condition that radiation refrigeration particles are not required to be added through optimization of materials, structures and thicknesses, and further avoids adverse effects of the addition of the radiation refrigeration particles on the mechanical property and the weather resistance of the radiation refrigeration film, so that the radiation refrigeration film has more excellent mechanical property and weather resistance and has excellent refrigeration effect.

The invention also provides an application of the radiation refrigeration film, wherein the radiation refrigeration film is arranged on the surface of the substrate and is used for reflecting sunlight and emitting heat through the atmospheric window in an infrared radiation mode.

In one embodiment, the substrate comprises at least one of a metal substrate, a ceramic substrate, a semiconductor substrate, a plastic substrate, a glass substrate, a rubber substrate, an asphalt substrate, a cement substrate, a textile substrate.

The invention also provides a product comprising the radiation refrigerating film, the product comprises a base body and the radiation refrigerating film arranged on the base body, one surface, far away from the emission layer 33, of the radiation refrigerating film is connected with the base body through an adhesive layer, and the surface, far away from the base body, of the emission layer 33 is a light incident side.

In an embodiment, the adhesive layer includes one of an acrylic adhesive, a polyurethane pressure sensitive adhesive, a hot melt adhesive film, and a butyl adhesive, and the thickness of the adhesive layer is 20 μm to 1500 μm, and further the thickness of the adhesive layer is 25 μm to 150 μm. The sunlight absorption rate of the adhesive layer is increased due to the fact that the adhesive layer is too thick, and the cooling effect of the radiation refrigerating film is further influenced; too thin an adhesive layer may degrade the adhesive properties and may further affect the service life of the radiation refrigerating film.

In one embodiment, the substrate comprises at least one of a metal substrate, a plastic substrate, a glass substrate, a rubber substrate, a bitumen substrate, a cement substrate, a textile substrate.

In an embodiment, the goods is radiation refrigeration waterproofing membrane, the base member is one of petroleum asphalt tyre asphalt felt, the fine child coiled material of petroleum asphalt glass, aluminium foil face coiled material, SBS modified asphalt waterproofing membrane, APP modified asphalt waterproofing membrane, EPT coiled material, polyvinyl chloride coiled material, chlorinated polyethylene coiled material, rubber blend coiled material, TPO waterproofing membrane.

In one embodiment, the article is a radiation-cooled metal sheet and the substrate is one of an aluminum alloy metal sheet, a zinc-plated metal sheet, a tin-plated metal sheet, a composite steel metal sheet, and a color-coated steel metal sheet.

Therefore, the radiation refrigeration film can be used on the outer surfaces of the enclosure structures such as grain depots, large public buildings (such as high-speed rail stations, airports, exhibition halls and museums), petrochemical storage tanks, power cabinets and communication cabinets, and can reflect sunlight and emit heat through an atmospheric window in an infrared radiation mode, so that the energy-consumption-free cooling of the enclosure structures is realized.

Hereinafter, the radiation refrigerating film and the product thereof will be further described by the following specific examples.

Example 1

The preparation method comprises the steps of taking a polyethylene terephthalate film with the thickness of 30 mu m as a carrier layer, placing the carrier layer at 120 ℃ for 30min to obtain a silver reflecting layer with the thickness of 100nm through magnetron sputtering, wherein the transverse thermal shrinkage rate of the carrier layer is 1.2%, and the longitudinal thermal shrinkage rate of the carrier layer is 1.4%, then coating polytetrafluoroethylene resin on the surface of the carrier layer, which is far away from the silver reflecting layer, and curing the polytetrafluoroethylene resin into an emitting layer with the thickness of 50 mu m to obtain the radiation refrigerating film.

Example 2

The polyethylene terephthalate film with the thickness of 30 mu m is used as a carrier layer, the carrier layer is placed at 120 ℃ for 30min, the thermal shrinkage rate in the transverse direction is 1.2%, the thermal shrinkage rate in the longitudinal direction is 1.4%, a silver reflecting layer with the thickness of 100nm is obtained on the carrier layer through magnetron sputtering, then polytetrafluoroethylene resin is coated on the silver reflecting layer, and the silver reflecting layer is solidified into an emitting layer with the thickness of 50 mu m, so that the radiation refrigerating film is obtained.

Example 3

Example 3 differs from example 1 in that a polytetrafluoroethylene film having a thickness of 50 μm was bonded to the surface of the support layer through a polyurethane adhesive layer having a thickness of 10 μm to obtain a radiation refrigerating film.

Example 4

Example 4 is different from example 3 in that the polytetrafluoroethylene film of example 4 is processed by an embossing process, and has a square embossed structure on the surface and a depth of 1 μm, and the embossed structure is disposed on the light incident surface of the emitting layer.

Example 5

Example 5 differs from example 3 in that the surface of example 5 for carrying a silver reflective layer was provided with an epoxy acrylic polymer coating having a thickness of 50nm, the surface energy was 56mN/m, and the absolute value of the difference in refractive index of the carrier layer and the polymer coating was 0.06.

Example 6

The preparation method comprises the steps of taking a polyethylene terephthalate film with the thickness of 15 mu m as a carrier layer, carrying out plasma treatment on one surface of the carrier layer to enable the surface of the carrier layer to reach 42mN/m after the carrier layer is placed at 120 ℃ for 30min, then carrying out magnetron sputtering on the surface to obtain a silver reflecting layer with the thickness of 50nm, then coating polytetrafluoroethylene resin on the surface of the carrier layer, which is far away from the silver reflecting layer, and curing the polytetrafluoroethylene resin to form an emitting layer with the thickness of 35 mu m, and forming a square embossing structure on the surface of the emitting layer through an embossing process to obtain the radiation refrigerating film, wherein the depth of the emitting layer is 0.5 mu m.

Example 7

A polyethylene terephthalate film having a thickness of 20 μm was used as a carrier layer, the carrier layer had a heat shrinkage rate of 1.5% in the transverse direction and 1.6% in the longitudinal direction after being left at 120 ℃ for 30 minutes, one surface of the carrier layer was coated with a polyurethane-based acrylate polymer coating having a thickness of 10nm, the surface energy was 42mN/m, and the absolute value of the difference in refractive index between the carrier layer and the polymer coating was 0.07. Then carrying out magnetron sputtering on the polymer coating to obtain a 60nm thick silver reflecting layer, then coating polytetrafluoroethylene resin on the surface of the carrier layer, which is far away from the silver reflecting layer, and curing the polytetrafluoroethylene resin into a 40 mu m thick emitting layer, and forming a square embossed structure on the surface of the emitting layer through an embossing process, wherein the depth of the emitting layer is 0.5 mu m, thus obtaining the radiation refrigerating film.

Example 8

A polyethylene terephthalate film having a thickness of 30 μm was used as a support layer, the support layer had a heat shrinkage rate of 1.2% in the transverse direction and 1.4% in the longitudinal direction after being left at 120 ℃ for 30 minutes, a polyester-based acrylate polymer coating layer having a thickness of 100nm was coated on one surface of the support layer, the surface energy was 47mN/m, and the absolute value of the difference in refractive index between the support layer and the polymer coating layer was 0.06. Then carrying out magnetron sputtering on the polymer coating to obtain a silver reflecting layer with the thickness of 50nm and an aluminum reflecting layer with the thickness of 50nm, then coating polytetrafluoroethylene resin on the surface of the carrier layer, which is far away from the silver reflecting layer, and curing the polytetrafluoroethylene resin into an emitting layer with the thickness of 15 microns, and forming a square embossed structure on the surface of the emitting layer through an embossing process, wherein the depth of the emitting layer is 1 micron, so as to obtain the radiation refrigerating film.

Example 9

A polyethylene terephthalate film having a thickness of 50 μm was used as a support layer, the support layer had a heat shrinkage rate of 0.8% in the transverse direction and 1.0% in the longitudinal direction after being left at 120 ℃ for 30 minutes, a polyester-based acrylate polymer coating layer having a thickness of 20nm was coated on one surface of the support layer, the surface energy was 47mN/m, and the absolute value of the difference in refractive index between the support layer and the polymer coating layer was 0.06. Then, magnetron sputtering is carried out on the polymer coating to obtain the silver reflecting layer with the thickness of 200 nm. And then adhering a polytetrafluoroethylene film with the thickness of 75 microns to the surface, away from the silver reflecting layer, of the carrier layer through a polyurethane adhesive layer with the thickness of 5 microns, wherein the polytetrafluoroethylene film is subjected to embossing processing, the surface has a square embossing structure, and the depth is 2 microns, so that the radiation refrigeration film is obtained.

Example 10

A polyethylene terephthalate film having a thickness of 35 μm was used as a support layer, the support layer had a heat shrinkage rate of 1.1% in the transverse direction and 1.2% in the longitudinal direction after being left at 120 ℃ for 30 minutes, a urethane acrylate polymer coating having a thickness of 50nm was coated on one surface of the support layer, the surface energy was 42mN/m, and the absolute value of the difference in refractive index between the support layer and the polymer coating was 0.07. Then carrying out magnetron sputtering on the polymer coating to obtain a silver reflecting layer with the thickness of 100nm and an aluminum reflecting layer with the thickness of 100nm, and then bonding a polytetrafluoroethylene film with the thickness of 110 mu m to the surface of the carrier layer away from the reflecting layer through a polyurethane adhesive layer with the thickness of 5 mu m, wherein the polytetrafluoroethylene film is subjected to embossing process treatment, the surface has a square embossing structure, and the depth is 2.5 mu m, so as to obtain the radiation refrigerating film.

Comparative example 1

Comparative example 1 differs from example 1 in that a mixed coating of polytetrafluoroethylene resin and silica particles, wherein the silica particles have a mass percentage of 1% and a particle diameter of 5 μm, is applied to the surface of the support layer facing away from the silver reflective layer.

Comparative example 2

Comparative example 2 is different from comparative example 1 in that the silica particles have a particle diameter of 5 μm with a mass percentage of 10%.

Comparative example 3

Comparative example 3 is different from example 3 in that the polyurethane glue layer contains silica particles, wherein the mass percentage of the silica particles is 1%, and the particle diameter is 5 μm.

Comparative example 4

Comparative example 4 is different from example 3 in that the polyurethane glue layer contains silica particles, wherein the silica particles are 10% by mass and have a particle diameter of 5 μm.

The radiation refrigeration films of examples 1 to 10 and comparative examples 1 to 4 were subjected to the following performance tests, and the results are shown in table 1.

Atmospheric window (8-13 μm) waveband emissivity test method: and (3) testing by using an infrared spectroscopy, wherein a testing instrument is a Fourier transform infrared spectrometer, the infrared emissivity of the wave band of 8-13 mu m is tested, the testing interval is 5nm, and the emissivity of the wave band of 8-13 mu m is the emissivity of the atmospheric window.

The method for testing the reflectivity of the sunlight (300nm-2500nm) wave band comprises the following steps: according to the regulation of GB/T25968-20106.2.

Gloss test method: the test is carried out according to the specification of GB/T9754-2007, and the test result of 60 ℃ is taken.

Xenon lamp aging test method: the xenon arc lamp should meet the regulations of GB/T16422.2-2014. The test was performed according to cycle 1 of GB/T16422.2-2014. When in test, the sample film surface faces to the light source and is placed for 1000 h.

Peel Strength test method: referring to the test method for 180-degree peel force and residual adhesion rate of release film of optical functional film in the standard GB/T25256-.

Elongation at break and tensile strength test methods: according to the regulation of chapter 5 in GB/T1040.1-2018. 3 pieces of long-strip sample (i.e., type 2 sample in GB/T1040.3-2006) having a test speed of 150mm/min, a width of 25mm and a length of not less than 150 mm. The edges of the sample should be ensured to be neat, smooth and unnotched. During the test, the sample is arranged on a clamp of a tensile testing machine, the clamp interval is 100mm, the sample is stretched at the speed of 100mm/min, and the maximum tensile force and the elongation of the sample when the sample is broken are measured. The elongation at break was calculated according to formula (1). The value is trimmed to one bit after the decimal point.

In the formula: e is elongation at break; l is₁Is the elongation at break of the specimen；L₀Is the initial distance between the clamps. Thermal shrinkage test method: refer to ASTM D1204.

TABLE 1

[ engineering application experiment ]

In order to simulate the cooling effect of the radiation refrigeration film in the building, two model houses A, B shown in fig. 6 are selected in the same environment in Ningbo city, the outer surface of the model house B is not processed, the radiation refrigeration film in the embodiment 1 is arranged on the outer surface of the model house A, 1 temperature measuring point A1 and B1 are respectively installed in the middle area of each model house A, B, an environment temperature measuring point is installed beside each model house, and the temperature data of the temperature measuring points A1 and B1 and the temperature data of the environment temperature in the range of 2020.10.1-2020.10.3 are continuously collected, as shown in the temperature curve in fig. 7.

As can be seen from fig. 7, (1) the radiation refrigeration film can effectively reduce the temperature inside the model house, and the maximum contrast temperature difference between the model house a and the model house B reaches 18 ℃; (2) before and after noon every day, the solar irradiation intensity reaches the maximum, and the temperature difference of the 2 model houses is the maximum at the moment; (3) the radiation refrigeration film can continuously and effectively reduce the overall temperature of the model house, and is energy-saving and environment-friendly.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.