A multi-gradient temperature regulating window film
By employing a composite functional layer design in the window film and utilizing vanadium dioxide with different doping ratios to prepare multiple phase transition temperature points, the problem that a single phase transition temperature cannot meet the diverse temperature changes inside the vehicle is solved, achieving a multi-gradient temperature regulation effect, reducing energy consumption and improving in-vehicle comfort and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANTONG NAR MATERIAL TECH CO LTD
- Filing Date
- 2024-10-15
- Publication Date
- 2026-06-02
AI Technical Summary
The single phase change temperature of existing temperature-regulating window films cannot meet the diverse usage scenarios with large temperature variations in different vehicles, resulting in the inability to effectively regulate the temperature inside the vehicle under different temperature environments, thus increasing energy consumption.
A composite functional layer is adopted, including an outer phase change layer and an inner phase change layer. The phase change temperature of the outer phase change layer is lower than that of the inner phase change layer. By doping vanadium dioxide with different proportions of elements, multiple phase change temperature points are prepared to achieve gradient changes in infrared transmittance and meet the control requirements of different temperature environments.
It achieves multi-gradient control of the vehicle interior temperature under different temperature environments, reducing energy consumption and improving the comfort and safety of the vehicle interior environment.
Smart Images
Figure CN224313449U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of protective film technology, specifically relating to a multi-gradient temperature-regulating window film. Background Technology
[0002] Solar radiation passes through the windshield and side windows of a vehicle and shines onto objects inside. These objects absorb and release heat, but the heat cannot be effectively dissipated, causing the interior temperature to rise rapidly. Additionally, the cooler outside air transfers heat through convection between the vehicle body and the interior environment, causing the interior temperature to drop as well. To ensure the comfort of passengers while driving, the car's air conditioning system heats or cools the air inside the cabin, maintaining a comfortable temperature range for the human body, reducing driver fatigue, and improving driving safety. However, car air conditioning systems have high energy consumption, affecting not only overall vehicle performance but also failing to meet daily energy-saving needs.
[0003] Currently, applying heat-insulating film to car windows helps improve the cooling effect of the air conditioning system, thereby reducing the car's energy consumption. Heat-insulating film can reflect or absorb infrared rays in sunlight to reduce the heat entering the car body. However, if the temperature inside the car is lower than the human body's comfortable temperature, using heat-insulating film cannot fully utilize solar radiation heat to increase the temperature inside the car.
[0004] Existing technologies incorporate vanadium dioxide nanomaterials into heat insulation films. Before the phase transition, vanadium dioxide nanomaterials are in a monoclinic rutile semiconductor state, allowing infrared light to pass through. After the phase transition, they become a tetragonal rutile metallic state, exhibiting high infrared reflectivity. The significant change in infrared transmittance before and after the phase transition allows for temperature regulation within the vehicle. Furthermore, the visible light transmittance remains essentially unchanged before and after the phase transition, meeting lighting requirements. Patent CN206242627U discloses a nano-intelligent heat insulation window film. This film incorporates an intelligent heat insulation adhesive layer containing an appropriate amount of nano-intelligent heat insulation material. Based on the ambient temperature, the adhesive layer automatically and selectively blocks or transmits infrared light based on the infrared rejection rate. When applied to automotive and building glass, this achieves heat insulation and energy-saving effects. However, the temperature inside a car varies greatly depending on the time of day and the region. When the temperature is below 15-20°C, it needs to be heated. When it is around 26°C, it needs to be kept warm. In hot weather, the temperature inside a car can reach 45-60°C, or even above 70°C, requiring rapid cooling. A single phase change temperature cannot meet the needs of more usage scenarios. Utility Model Content
[0005] To address the shortcomings of existing temperature-regulating window films that have a single phase change temperature and cannot meet the needs of various application scenarios due to the large range of temperature changes inside the vehicle, the purpose of this invention is to provide a multi-gradient temperature-regulating window film. The composite functional layer includes an outer phase change layer and an inner phase change layer with increasing phase change temperature, which increases the number of nodes where infrared transmittance changes, and makes the heat entering the vehicle change in a gradient, thereby regulating the temperature inside the vehicle in multiple gradients.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: a multi-gradient temperature-regulating window film, comprising a composite functional layer, wherein the composite functional layer comprises an outer phase change layer and an inner phase change layer from the outside to the inside, and the phase change temperature of the outer phase change layer is lower than that of the inner phase change layer.
[0007] Furthermore, the phase change materials of the outer and inner phase change layers are vanadium dioxide with nano-doped elements, and the doping ratio of the outer phase change layer is higher than that of the inner phase change layer.
[0008] Furthermore, the raw materials for the outer phase change layer and the inner phase change layer also include a matrix, which is polyurethane.
[0009] Furthermore, the doping element in the vanadium dioxide nanoparticles is tungsten, with a doping ratio of 0% to 2%.
[0010] Furthermore, a protective layer is provided on each side of the composite functional layer. One protective layer is coated with an anti-wear and scratch-resistant layer on the side away from the composite functional layer, and the other protective layer is coated with an installation adhesive layer on the side away from the composite functional layer.
[0011] Furthermore, the protective layer is a PET film with added additives, the additives being nano-sized silicon dioxide, with a thickness of 18-23 μm and a visible light transmittance of over 90%.
[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model improves the composite functional layer of the existing window film by combining phase change layers with increasing phase change temperatures from the outside to the inside, so that the composite functional layer has a gradient change in phase change temperature, which can meet more usage scenarios; the phase change layers with different phase change temperatures are made by doping vanadium dioxide with different proportions of elements. The infrared light transmittance of vanadium dioxide with nano-doped elements changes before and after the phase change, and multiple phase change layers can increase the number of nodes where infrared light transmittance changes, so that the heat entering the vehicle changes in a gradient, which can meet the needs of different ambient temperatures in the vehicle. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the structure of this utility model;
[0014] Among them, 11 is the outer phase change layer, 12 is the inner phase change layer, 21 is the outer protective layer, 22 is the inner protective layer, 3 is the mounting adhesive layer, and 4 is the wear-resistant and scratch-resistant layer. Detailed Implementation
[0015] To clearly, accurately, and completely express the technical means of realizing this utility model, the present utility model will be further described below in conjunction with the embodiments and accompanying drawings.
[0016] The higher the total solar energy rejection rate of a window film, the better its heat insulation performance. The total solar energy rejection rate is equal to (1 - infrared transmittance) multiplied by 53%, plus (1 - visible light transmittance) multiplied by 44%, plus ultraviolet light rejection rate multiplied by 3%. It can be seen that as the infrared transmittance decreases, the total solar energy rejection rate increases, and the heat insulation effect also improves.
[0017] This invention improves upon existing window film composite functional layers by combining multiple phase change layers with different phase transition temperatures, making the composite functional layer adaptable to more application scenarios. Phase change layers with different phase transition temperatures are prepared by doping vanadium dioxide with different proportions of elements. The doping elements inject holes or electrons into vanadium dioxide, promoting or hindering the phase transition. Doping with elements whose ionic radii are larger than tetravalent vanadium ions can significantly lower the phase transition temperature of vanadium dioxide, while doping with smaller ionic radii and lower valence states will increase the phase transition temperature. Furthermore, using different phase change materials for different phase change layers influences the consistency of mechanical and optical properties. Considering cost and production factors, the composite functional layer consists of a two-layer structure from the outside in, consisting of an outer phase change layer and an inner phase change layer. The phase change temperature of the outer phase change layer is lower than that of the inner phase change layer. Assuming that the heat inside the vehicle is higher than that outside and is in the rising phase, the heat inside the vehicle is first conducted from the inner phase change layer to the outer phase change layer, causing the outer phase change layer to undergo a phase change and reducing the infrared transmittance. If the heat increases further, the inner phase change layer will rapidly undergo a phase change, further reducing the infrared transmittance. However, if the phase change temperature of the outer phase change layer is higher than that of the inner phase change layer, the heat inside the vehicle will cause the inner phase change layer to undergo a phase change. If the heat increases further, it needs to be conducted from the inner phase change layer to the outer phase change layer before the outer phase change layer can undergo a phase change. In the high-heat state inside the vehicle, it is even more necessary to rapidly cause the inner phase change layer to undergo a phase change. Therefore, the phase change temperature of the outer phase change layer is lower than that of the inner phase change layer.
[0018] The phase change materials of the outer and inner phase change layers of this invention are vanadium dioxide with nano-doped elements. The doping ratio of the outer phase change layer is higher than that of the inner phase change layer. The doping element is tungsten, and the doping ratio is 0% to 2%. When the doping ratio is 0%, that is, pure vanadium dioxide, the phase change temperature is 68°C, which can be used to control the high interior temperature of the vehicle when no one is inside during hot weather. The phase change temperature of vanadium dioxide doped with 1% tungsten is 43°C, that of vanadium dioxide doped with 1.5% tungsten is 30°C, and that of vanadium dioxide doped with 2% tungsten is 20-25°C. Because the phase change temperature of the outer phase change layer is lower than that of the inner phase change layer, the combination of the two phase change temperature points increases the number of nodes where infrared transmittance changes, allowing the heat entering the vehicle to change in a gradient, meeting multiple usage scenarios, effectively balancing the indoor temperature, and reducing energy consumption. As the doping ratio of the phase change layer increases, the decrease in visible light transmittance also increases. Furthermore, the visible light transmittance decreases after the phase change layer undergoes a phase change at its phase change temperature. Therefore, this invention employs multiple phase change layers. One phase change layer undergoes a phase change sufficient to meet the infrared transmittance requirements, while another phase change layer does not need to undergo a phase change, thus minimizing the impact on visible light transmittance. Vanadium dioxide, a nano-doped element, is dispersed in a polyurethane matrix and coated to form an outer and inner phase change layer. The polyurethane matrix possesses advantages such as impact resistance and strong adhesion, enabling the fabrication of composite functional layers.
[0019] To protect the composite functional layer, a protective layer is provided on each side of the composite functional layer. The protective layer protecting the outer phase change layer is called the outer protective layer, and the protective layer protecting the inner phase change layer is called the inner protective layer. The protective layers, serving as the carrier of the composite functional layer, are made of polyester film, whose tensile strength is 3 to 5 times that of polypropylene or polyethylene films. Its uniform longitudinal and transverse tensile properties ensure the clarity and stability of the overall window film. The polyester film of this invention is an additive-containing polyester film, with nano-sized silica as the additive. This additive has minimal effect on light refraction and reflection. When light shines on the polyester film, the light waves bypass the tiny silica additive particles and pass directly through the polyester film. Therefore, light diffusion is minimal, increasing light transmittance and transparency, fully utilizing the control effect of the composite functional layer. The additive also makes the film surface smooth, improving the winding effect of the polyester film and facilitating subsequent processing.
[0020] Window film is typically applied to the inside of car windows. During use, it is less susceptible to external interference, thus extending its lifespan. Additionally, one side of the film features an anti-scratch and scratch-resistant layer with excellent scratch and abrasion resistance, preventing scratches from wiping or washing and keeping the film surface looking new for a long time. The other side has an adhesive layer for bonding to the glass. This adhesive provides adhesion and, together with the protective layer, provides safety protection. When the film is impacted, the tensile strength of the polyester film and the adhesive layer pull the glass together, preventing fragments from flying and penetration.
[0021] Example 1
[0022] In this embodiment, the window film is used on the inside of the vehicle window glass, such as... Figure 1 As shown, the window film includes, from the outside to the inside, an adhesive layer 3, an outer protective layer 21, an outer phase change layer 11, an inner phase change layer 12, an inner protective layer 22, and an anti-abrasion and scratch-resistant layer 4.
[0023] An inner phase change layer 12 with a phase change temperature of 30°C is obtained by coating a mixture of vanadium dioxide containing 1.5% tungsten nanoparticles onto one surface of the inner protective layer 22 and then curing it. An outer phase change layer 11 with a phase change temperature of 20°C is obtained by coating a mixture of vanadium dioxide containing 2% tungsten nanoparticles onto the surface of the inner phase change layer 12 and then curing it. The outer phase change layer 11 is laminated with the outer protective layer 21. A scratch-resistant material is coated on the other surface of the inner protective layer 22 to form a scratch-resistant and wear-resistant anti-scratch layer 4. The other surface of the outer protective layer 21 is laminated with a release film coated with an installation adhesive layer 3. The release film is used to protect the installation adhesive layer and is removed when the window film is installed.
[0024] The window film in this embodiment has two phase transition points, namely 20°C and 30°C. Below 20°C, both nano-doped vanadium dioxide with 1.5% tungsten and nano-doped vanadium dioxide with 2% tungsten are in a semiconductor state, exhibiting high infrared light transmittance. This allows for full utilization of solar radiation heat and can also improve the heating effect of the air conditioning system, thereby reducing vehicle energy consumption. Between 20°C and 30°C, nano-doped vanadium dioxide with 2% tungsten is in a metallic state, with infrared transmittance decreasing by 55%, while nano-doped vanadium dioxide with 1.5% tungsten is in a semiconductor state, with no change in infrared light transmittance. Infrared light is partially blocked by the outer layer of nano-doped vanadium dioxide with 2% tungsten, while the remaining portion can... Vanadium dioxide nanoparticles doped with 1.5% tungsten can be used to maintain the temperature inside the vehicle. In addition, research shows that infrared radiation also has certain benefits for the human body, promoting blood circulation and metabolism. When the temperature rises above 30°C, vanadium dioxide nanoparticles doped with 1.5% tungsten are in a metallic state, and the infrared light transmittance decreases by 75%, further blocking the transmission of infrared radiation and achieving a heat insulation effect. For vehicles parked outdoors in hot weather, the interior temperature can be reduced to below 40°C, preventing the aging process of interior components from accelerating, and ensuring that passengers do not experience unbearable heat inside the vehicle.
[0025] Example 2
[0026] In this embodiment, the window film is used on the inside of the vehicle window glass, such as... Figure 1 As shown, the window film includes, from the outside to the inside, an adhesive layer 3, an outer protective layer 21, an outer phase change layer 11, an inner phase change layer 12, an inner protective layer 22, and an anti-abrasion and scratch-resistant layer 4.
[0027] An inner phase change layer 12 with a phase change temperature of 68°C is obtained by coating a mixture containing nano-vanadium dioxide onto one surface of the inner protective layer 22 and then curing it. An outer phase change layer 11 with a phase change temperature of 43°C is obtained by coating a mixture containing nano-doped 1% tungsten vanadium dioxide onto the surface of the inner phase change layer 12 and then curing it. The outer phase change layer 11 is laminated with the outer protective layer 21. A scratch-resistant material is coated on the other surface of the inner protective layer 22 to form a scratch-resistant and wear-resistant anti-scratch layer 4. The other surface of the outer protective layer 21 is laminated with a release film coated with an installation adhesive layer 3. The release film is used to protect the installation adhesive layer and is removed when the window film is installed. The outer protective layer 21 is a polyester film with added heat insulation material and an infrared transmittance of 65%.
[0028] The window film in this embodiment has two phase transition points, namely 43°C and 68°C. The phase transition occurs at 43°C and 68°C, respectively, and the infrared transmittance decreases, thereby reducing the infrared transmittance gradient and lowering the temperature inside the vehicle.
Claims
1. A multi-gradient temperature-regulating window film, characterized in that, The system includes a composite functional layer, comprising an outer phase change layer and an inner phase change layer from the outside in. The phase change temperature of the outer phase change layer is lower than that of the inner phase change layer. The phase change materials of the outer and inner phase change layers are vanadium dioxide with nano-doped elements, and the doping ratio of the outer phase change layer is higher than that of the inner phase change layer. The raw materials of the outer and inner phase change layers also include a matrix, which is polyurethane.
2. The multi-gradient temperature-regulating window film according to claim 1, characterized in that, The vanadium dioxide nanoparticles are tungsten as the doping element, with a doping ratio of 0% to 2%.
3. The multi-gradient temperature-regulating window film according to claim 1, characterized in that, The composite functional layer has a protective layer on each side. One of the protective layers is coated with an anti-wear and scratch-resistant layer on the side away from the composite functional layer, and the other protective layer is coated with an installation adhesive layer on the side away from the composite functional layer.
4. The multi-gradient temperature-regulating window film according to claim 3, characterized in that, The protective layer is a PET film with added additives, the additives being nano-sized silicon dioxide, with a thickness of 18~23μm and a visible light transmittance of over 90%.