Radiative cooling film structure

Abstract

The utility model is suitable for intelligent protection material field, provide radiation refrigeration film structure, including film main part, the film main part includes surface layer and bottom layer, the surface layer is radiation refrigeration layer, the surface layer adopts hierarchical porous nested structure, hierarchical porous nested structure contains nanometer level pore and micrometer level pore, nanometer level pore and micrometer level pore staggered arrangement each other, in the utility model, high -efficient cooling, energy -conserving and loss reducing: surface layer adopts hierarchical porous nested structure, contains nanometer level and micrometer level pore, this structure can high -efficiently reflect sunlight, and realizes passive cooling by using atmospheric window infrared radiation, under the high temperature environment in summer, can significantly reduce indoor temperature, greatly reduces air conditioning use frequency, reduces building energy consumption, has promoted indoor comfort level again, has saved energy cost.

Description

Technical Field

[0001] This utility model belongs to the field of intelligent protective materials, and in particular relates to radiation cooling film structures. Background Technology

[0002] In the field of building energy conservation and protection, traditional architectural window films have many drawbacks. Ordinary films can only provide basic heat insulation and protection functions, and cannot effectively cope with the high indoor temperatures caused by solar radiation in summer, resulting in high air conditioning energy consumption and increasing the building's energy costs. Some reflective films can reflect some sunlight, but they pose a risk of light pollution and are difficult to achieve sustained cooling through radiative heat dissipation. Some films using heat-absorbing materials rise in temperature after absorbing heat, resulting in limited cooling effects and potentially accelerating material aging. These traditional films cannot meet the demands of modern buildings for energy conservation, environmental protection, and efficient heat insulation. Therefore, radiative cooling film structures are needed to solve these problems. Utility Model Content

[0003] The purpose of this utility model embodiment is to provide a radiation cooling film structure to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A radiation-cooling membrane structure includes a membrane body, which includes a surface layer and a bottom layer. The surface layer is a radiation-cooling layer and adopts a hierarchical porous nested structure. The hierarchical porous nested structure includes nano-sized pores and micro-sized pores, which are arranged alternately.

[0006] The surface substrate is polycarbonate or ethylene-vinyl acetate copolymer, and titanium dioxide nanoparticles and boron nitride microplates are added to the surface substrate.

[0007] The bottom layer is a primer layer, which uses an acrylic-modified polyurethane adhesive.

[0008] In a further technical solution, the diameter of the nanoscale pores on the surface layer is 50-200 nm, and the diameter of the microscale pores is 1-10 μm.

[0009] In a further technical solution, the surface layer is modified with a hydrophobic agent, the surface contact angle is ≥110°, and the substrate hardness is ≥2H.

[0010] A further technical solution is that the surface layer uses intrinsic flame-retardant materials or encapsulates phosphorus / nitrogen-based flame retardants using microencapsulation technology, achieving a flame retardant rating of UL94V-0.

[0011] A further technical solution is that the overall thickness of the membrane body is 0.3-0.5mm, it adopts a flexible substrate, has a honeycomb microstructure inside, and is sealed by hot pressing on all sides and has an internal elastic fiber mesh.

[0012] A further technical solution is that the peel strength between the bottom layer and the outer surface of the car is ≥5N / cm, and the bottom layer forms a protective layer with a thickness of 0.1-0.3mm.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] This invention offers efficient cooling and energy conservation: the surface layer adopts a hierarchical porous nested structure containing nano- and micro-sized pores. This structure can efficiently reflect sunlight and utilize atmospheric window infrared radiation to achieve passive cooling. In high-temperature summer environments, it can significantly reduce indoor temperature, greatly reduce the frequency of air conditioning use, and reduce building energy consumption, thereby improving indoor comfort and saving energy costs.

[0015] This utility model is waterproof and moisture-proof: the surface of the membrane body is specially treated, with a surface contact angle ≥110°, which has excellent hydrophobicity; when rainwater falls on the membrane surface, it will form water droplets and roll off quickly, unable to penetrate into the pores, effectively blocking rainwater from corroding the glass, preventing the glass from fogging, mold and other problems caused by long-term contact with rainwater, and extending the service life of the glass.

[0016] Scratch and wear resistant: The surface substrate has a hardness of ≥2H, and with its dense porous structure, it has strong resistance to external impact. When it encounters wind, sand or hard objects, the porous structure can disperse stress and control the scratch depth to ≤50μm, which can effectively protect the glass surface and reduce the appearance damage caused by accidental scratches during daily use of architectural glass.

[0017] Flame retardant safety: The surface is made of flame retardant materials or treated with special encapsulation technology, and the flame retardant rating reaches UL94V-0. When exposed to high temperature or fire source, it can quickly suppress the spread of flame and will not release toxic gases, providing a higher guarantee for the safety of people and property inside the building, especially suitable for building glass in densely populated places.

[0018] Weather-resistant and anti-aging: Special light stabilizers and ultraviolet absorbers are added to the surface, which can effectively capture free radicals generated by ultraviolet radiation and inhibit material aging and degradation. No matter the harsh environment such as strong ultraviolet rays, high temperature or wind and rain, the membrane body can maintain stable performance for a long time, reducing the need for frequent replacement due to environmental factors and reducing maintenance costs.

[0019] This utility model is convenient, practical, and flexibly adaptable: the overall thickness of the membrane body is only 0.3-0.5mm, made of flexible substrate, with a honeycomb microstructure inside, and sealed by heat pressing on all sides with an internal elastic fiber mesh. These designs enable it to maintain good elasticity within an ambient temperature range of -10℃ to 60℃, and can withstand ≥1000 bending cycles without breakage. During installation, it can be flexibly cut according to the glass size, making construction convenient. When not in use, the membrane body can be easily folded and stored for easy storage and transportation.

[0020] This invention offers a stable and superior fit: the bottom layer uses an acrylic-modified polyurethane adhesive with a bonding strength ≥5N / cm to the surface of architectural glass (including ordinary glass, tempered glass, etc.), ensuring a firm adhesion and preventing detachment. The bottom layer also forms a 0.1-0.3mm thick protective adhesive layer, which not only prevents external dust and moisture from corroding the glass but also fills in the minor unevenness of the glass surface, resulting in a smoother surface adhesion. This ensures uniformity of sunlight reflection and infrared radiation, further enhancing the cooling and protective effects of the membrane.

[0021] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the elastic fiber mesh of this utility model.

[0024] In the figure: 1. Membrane body; 11. Surface layer; 111. Nanoscale pores; 112. Micrometer-scale pores; 113. Titanium dioxide nanoparticles; 114. Boron nitride microsheets; 12. Bottom layer; 2. Elastic fiber mesh. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0027] like Figures 1-2As shown, this utility model embodiment provides a radiation-cooling film structure, including a film body 1, which includes a surface layer 11 and a bottom layer 12. The surface layer 11 is a radiation-cooling layer, and the surface layer 11 adopts a hierarchical porous nested structure to simulate the micro-nano optical properties of the beetle elytra. The hierarchical porous nested structure includes nano-scale pores 111 and micro-scale pores 112. The nano-scale pores 111 and micro-scale pores 112 are arranged alternately to form a unique multi-scale pore structure, so as to achieve efficient solar light reflection and atmospheric window infrared radiation.

[0028] The surface layer 11 is made of polycarbonate or ethylene-vinyl acetate copolymer, which has good flexibility and physical properties. Titanium dioxide nanoparticles 113 and boron nitride microflakes 114 are added to the surface layer 11 substrate. Titanium dioxide nanoparticles 113 enhance the ability to reflect sunlight. Boron nitride microflakes 114 improve infrared radiation efficiency. The bottom layer 12 is an adhesive layer, which uses acrylic modified polyurethane adhesive, which has high elasticity and strong adhesion.

[0029] In this embodiment, the main focus is on describing the operational process and corresponding effects of the structures, and the function of each structure is described in detail. Specifically, the nanoscale pores 111 of the surface layer 11 have a diameter of 50-200 nm, and the microscale pores 112 have a diameter of 1-10 μm.

[0030] Specifically, the surface layer 11 is modified with a hydrophobic agent, with a surface contact angle ≥110°, providing excellent waterproof performance. The substrate hardness is ≥2H, which can resist minor scratches caused by wind, sand, and hard objects, with a scratch depth ≤50μm.

[0031] Specifically, the surface layer 11 uses intrinsically flame-retardant materials or encapsulates phosphorus / nitrogen-based flame retardants using microencapsulation technology, achieving a UL94V-0 flame retardancy rating and not releasing toxic gases at high temperatures. Specifically, the membrane body 1 has an overall thickness of 0.3-0.5mm, uses a flexible substrate, has a honeycomb microstructure, and is heat-sealed on all sides with an internal elastic fiber mesh 2, capable of withstanding ≥1000 bending cycles, ensuring convenient folding and storage while maintaining structural integrity. Specifically, the bottom layer 12 has an adhesion strength ≥5N / cm to the architectural glass surface, ensuring a tight bond between the bottom layer 12 and the glass surface; the bottom layer 12 forms a 0.1-0.3mm thick adhesive protective layer, effectively blocking rainwater, moisture, dust, and other external substances from corroding the glass; furthermore, it fills the minor unevenness of the glass surface, making the surface layer 11 adhere more smoothly and ensuring uniform cooling effect.

[0032] The working principle of this utility model:

[0033] Cooling principle: When sunlight shines on the surface layer 11 of the membrane body 1, the nano-sized pores 111 produce Mie scattering of ultraviolet-visible light waves (300-760nm), and the micron-sized pores 112 produce Bragg reflection of near-infrared light waves (760-2500nm). The two work together to reflect most of the sunlight, greatly reducing heat absorption. At the same time, the BN microplates in the surface layer 11 can directionally emit infrared waves of 8-13μm. This waveband is an atmospheric window, and heat can be directly radiated into space through this waveband, thereby achieving passive cooling with zero energy consumption, making the indoor temperature 5-10℃ lower than the outdoor ambient temperature.

[0034] Waterproofing principle: After the surface layer 11 is modified with a hydrophobic agent, a low surface energy structure is formed on the surface. The contact angle of water molecules on the surface is ≥110°, which prevents them from penetrating into the pores. Rainwater can only form water droplets on the membrane surface and roll off, thus achieving a waterproof effect.

[0035] Scratch-resistant principle: The high-hardness surface layer 11 substrate 2H-3H combined with the dense porous structure can effectively resist external impact; when subjected to slight scratches, the porous structure can disperse stress, reduce damage to the substrate, and control the scratch depth to ≤50μm.

[0036] Weather resistance principle: The hindered amine light stabilizer and ultraviolet absorber added to the surface layer 11 can capture free radicals generated by ultraviolet radiation, effectively inhibiting the aging and degradation process of the material; under the influence of long-term light exposure, high temperature and other environmental factors, it can still maintain stable performance and ensure weather resistance ≥ 5 years;

[0037] Folding and storage principle: The flexible substrates EVA and TPU used in the membrane body 1 have low glass transition temperatures and maintain elasticity over a wide temperature range, enabling it to withstand repeated folding; the internal honeycomb microstructure can evenly distribute stress during folding, avoiding local stress concentration that could lead to membrane body breakage; the elastic fiber mesh 2 and silicone edge design around the perimeter further enhance the flexibility and wear resistance of the edges, allowing the membrane body 1 to maintain good structural integrity and performance even after multiple folds.

[0038] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A radiation-cooled membrane structure, comprising a membrane body (1), characterized in that: The membrane body (1) includes a surface layer (11) and a bottom layer (12). The surface layer (11) is a radiation cooling layer. The surface layer (11) adopts a hierarchical porous nested structure. The hierarchical porous nested structure includes nano-sized pores (111) and micro-sized pores (112). The nano-sized pores (111) and micro-sized pores (112) are arranged alternately. The substrate of the surface layer (11) is polycarbonate or ethylene-vinyl acetate copolymer, and titanium dioxide nanoparticles (113) and boron nitride microplates (114) are added to the substrate of the surface layer (11). The bottom layer (12) is a primer layer, which uses acrylic modified polyurethane adhesive.

2. The radiation-cooling film structure according to claim 1, characterized in that: The surface layer (11) has nanoscale pores (111) with a diameter of 50-200 nm and microscale pores (112) with a diameter of 1-10 μm.

3. The radiation-cooling film structure according to claim 1, characterized in that: The surface layer (11) is modified with a hydrophobic agent, with a surface contact angle ≥110° and a substrate hardness ≥2H.

4. The radiation-cooling film structure according to claim 1, characterized in that: The surface layer (11) is made of intrinsic flame retardant material or encapsulated with phosphorus / nitrogen flame retardant through microencapsulation technology, and the flame retardant rating reaches UL94V-0.

5. The radiation-cooling film structure according to claim 1, characterized in that: The membrane body (1) has an overall thickness of 0.3-0.5 mm, uses a flexible substrate, has a honeycomb microstructure inside, and is sealed by hot pressing on all sides and has an internal elastic fiber mesh (2).

6. The radiation-cooling film structure according to claim 1, characterized in that: The peel strength between the bottom layer (12) and the outer surface of the vehicle is ≥5N / cm, and the bottom layer (12) forms a protective layer with a thickness of 0.1-0.3mm.

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