Heat-insulating and anti-reflection functional film

Abstract

The utility model discloses a heat-insulation anti-reflection functional film which comprises a base material layer, a titanium dioxide layer, an indium tin oxide layer, a base layer and an anti-reflection layer which are sequentially stacked, the refractive index of the indium tin oxide layer ranges from 1.8 to 2.0, and the refractive index of the antireflection layer ranges from 1.40 to 1.45. On one hand, the heat insulation and anti-reflection functional film can reduce external heat entering a vehicle and reduce the use energy consumption of the vehicle in daily life, the viewing of passengers to external natural landscapes can be greatly enhanced by matching with the anti-reflection coating, and due to the fact that the forbidden band width (band gap) of the ITO thin film is usually between 3.5 eV and 4.3 eV, the heat insulation and anti-reflection functional film has a good anti-reflection effect. The energy of photons in the ultraviolet light area is larger than the forbidden band width, so that photons are absorbed and electron transition is caused, the extremely low light penetration rate is shown, and therefore the skin of a user in the vehicle can be protected from being hurt by ultraviolet rays.

Description

Technical Field

[0001] This utility model belongs to the field of optical film technology, specifically relating to a heat-insulating and anti-reflective functional film. Background Technology

[0002] Existing automotive sunroofs generally use ordinary glass or single-layer coated glass. While their light transmittance meets basic requirements (approximately 80%-90%), they are prone to glare or reflection interference in complex lighting conditions, affecting the driver's visibility. For example, while fixed panoramic sunroofs offer superior visual transparency, it's difficult to balance light transmittance with heat insulation. Especially under direct sunlight, they require auxiliary devices such as sunshades, reducing the continuity of the user experience. Furthermore, traditional sunroof structures (such as multi-layered glass or metal frames) may suffer from reduced light scattering or transmission efficiency due to thickness or material limitations, making it difficult to achieve truly "seamless enhanced transparency."

[0003] Furthermore, the heat insulation performance of sunroofs mainly relies on the glass material and coating technology, but existing solutions have significant shortcomings. Ordinary sunroof glass has limited reflectivity for infrared radiation (approximately 60%-80% for near-infrared radiation), and its blocking effect on far-infrared radiation (such as interior heat radiation) is even worse, causing the interior temperature to rise rapidly in summer, requiring additional cooling with air conditioning and increasing energy consumption. Although some models use Low-E coating technology to improve infrared reflectivity, the coating's durability is insufficient, and it is prone to oxidation or scratches after long-term use, leading to performance degradation. In addition, panoramic sunroofs, due to their large area and complex sealing structure, are prone to aging of the rubber seals due to thermal expansion and contraction, further weakening the heat insulation effect and causing leakage problems.

[0004] Current patents often focus on optimizing a single performance aspect (such as sealing, durability, or safety), lacking a synergistic design for anti-reflective and thermal insulation. For example, the "skylight glass clamp patent" (CN222138055U) simplifies the installation process but fails to address the inherent thermal conductivity limitations of glass. While the "automatic window-breaking patent" (CN119659517A) enhances emergency escape capabilities, it does not consider the optical and thermal management needs of everyday use.

[0005] Therefore, in order to address the aforementioned technical problems, it is necessary to provide a heat-insulating and light-reflecting functional film.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0007] The purpose of this invention is to provide a heat-insulating and light-transmitting functional film that combines heat insulation and light transmission properties, thereby improving the light transmission and heat insulation effects of car sunroofs.

[0008] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:

[0009] A heat-insulating and anti-reflective functional film includes a substrate layer, a titanium dioxide layer, an indium tin oxide layer, an underlayer, and an anti-reflective layer stacked sequentially.

[0010] The refractive index of the indium tin oxide layer is 1.8-2.0, and the refractive index of the antireflective layer is 1.40-1.45.

[0011] In one or more embodiments of this utility model, the thickness of the indium tin oxide layer is 50nm-300nm.

[0012] In one or more embodiments of this utility model, the thickness of the antireflection layer is 80nm-100nm.

[0013] In one or more embodiments of this utility model, the antireflective layer is an acrylic resin layer.

[0014] In one or more embodiments of this utility model, the thickness of the titanium dioxide layer is 10nm-20nm.

[0015] In one or more embodiments of this utility model, the underlayer is a silicon dioxide layer.

[0016] In one or more embodiments of this utility model, the thickness of the underlay layer is 10nm-20nm.

[0017] In one or more embodiments of this utility model, the anti-reflective layer is further provided on the side of the anti-reflective layer away from the base layer, and the thickness of the anti-fouling layer is 10nm-20nm.

[0018] In one or more embodiments of this utility model, the substrate layer is a PET layer with a thickness of 23μm-125μm.

[0019] Compared with existing technologies, the heat-insulating and anti-reflective functional film of this invention can reduce the amount of external heat entering the vehicle interior, thereby reducing energy consumption during daily vehicle use. Combined with an anti-reflective coating, it can significantly enhance passengers' view of the natural scenery. Furthermore, because the band gap of ITO films is typically between 3.5 and 4.3 eV, and the photon energy in the ultraviolet region is greater than this band gap, photons are absorbed and electrons undergo transitions, resulting in extremely low light transmittance. Therefore, it can protect the skin of vehicle occupants from ultraviolet radiation damage. When this heat-insulating and anti-reflective functional film is used in automotive sunroofs, it can significantly improve the sunroof's anti-reflective and heat-insulating effects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of the heat-insulating and anti-reflective functional membrane in one embodiment of the present invention.

[0022] Explanation of key figure labels:

[0023] 1. Substrate layer; 2. Titanium dioxide layer; 3. Indium tin oxide layer; 4. Undercoat layer; 5. Anti-reflective layer; 6. Anti-fouling layer. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0025] The existing automotive sunroofs have the following main defects: (1) Insufficient heat insulation: Sunroofs generally rely on traditional coating technology (such as Low-E coating) to improve infrared reflectivity, but their blocking efficiency for far-infrared bands (such as heat radiation inside the car) is low. Moreover, the coating is prone to performance degradation due to oxidation or scratches. In addition, the sunroof (fixed panoramic glass) cannot be opened and lacks sunshade curtains, so the heat insulation effect is extremely poor when directly exposed to sunlight in summer, the temperature inside the car rises rapidly, and air conditioning is required for additional cooling, which significantly increases energy consumption; (2) Contradiction between light transmittance and functionality: Although the light transmittance of traditional sunroofs (80%-90%) meets the basic requirements, it is easy to produce glare or reflection interference when strong light shines directly, requiring auxiliary equipment such as sunshade curtains, which damages visual transparency; (3) Existing patented technologies mostly focus on single performance optimization and lack innovation in the synergistic design of enhanced light transmittance and heat insulation, which often results in the sacrifice of heat insulation performance when light transmittance is improved.

[0026] A specific embodiment of this utility model provides a heat-insulating and anti-reflective functional membrane, such as... Figure 1 As shown, the material includes a substrate layer 1, a titanium dioxide layer 2, an indium tin oxide layer 3, a base layer 4, an anti-reflective layer 5, and an anti-fouling layer 6, which are stacked sequentially. The indium tin oxide layer 3 has a refractive index of 1.8-2.0, and the anti-reflective layer 5 is an acrylic resin layer with a refractive index of 1.40-1.45.

[0027] Specifically, ITO (indium tin oxide) possesses both infrared resistance and high refractive index properties, primarily due to the synergistic effect of its high carrier concentration and plasma effect. ITO has an extremely high concentration of free electrons (approximately 10⁻⁶). 21 cm -3 Under optical frequencies, ITO forms collective oscillations (plasma oscillations), significantly enhancing its dielectric response and giving it a high refractive index (approximately 1.8–2.0) in the visible light band, thus achieving optical anti-reflection or waveguide functions. Simultaneously, its plasma frequency is located in the near-infrared band (1.5–3 μm). When the incident infrared light frequency is below this threshold, ITO exhibits metallic properties, reflecting near-infrared radiation (reflectivity can reach over 80%; free electrons in the ITO film interact with infrared photons, generating plasma oscillations, causing most of the infrared light to be reflected back), effectively blocking heat transmission.

[0028] This invention utilizes ITO as a high-refractive-index layer, while simultaneously coating its surface with a low-refractive-index anti-reflective layer. Through the synergistic effect of multilayer interference and refractive index gradient matching, reflection under strong light is reduced, increasing the transmittance of the thin film. Furthermore, an anti-scratch and anti-fouling layer is coated on its surface to extend its service life.

[0029] Furthermore, the substrate layer is a PET (polyethylene terephthalate) layer with a thickness of 23μm-125μm. Specifically, 23μm, 50μm, 60μm, 100μm, 100μm or 125μm can be selected. Based on the total light transmittance of the substrate, a PET substrate with a total light transmittance of more than 90% is preferred.

[0030] Furthermore, the titanium dioxide layer has a thickness of 10nm-20nm, and the indium tin oxide layer has a thickness of 50nm-300nm.

[0031] Specifically, a TiO2 layer is deposited on the substrate layer using medium-frequency magnetron sputtering. PET substrates have low surface energy and are chemically inert; direct ITO deposition can easily lead to poor film adhesion, potentially resulting in peeling or cracking during long-term use. Introducing a TiO2 interlayer significantly improves interfacial bonding strength, buffers stress caused by temperature changes, and reduces coating cracking.

[0032] Furthermore, the base layer is a silicon dioxide layer with a thickness of 10nm-20nm; the antireflective layer has a thickness of 80nm-100nm.

[0033] Specifically, the antireflective layer is formed by coating with an acrylic resin solution (model Arakawa Chemical SL045). The SiO2 surface is rich in active hydroxyl groups, which can form hydrogen bonds or covalent bonds with polar groups (such as hydroxyl and amino groups) in the resin. This chemical bonding significantly improves the interfacial bonding energy, rather than relying solely on mechanical intercalation. Furthermore, SiO2, as the underlayer, can cover microscopic defects in the coating, reducing stress concentration points and preventing the resin coating from peeling off due to localized weak areas. Simultaneously, its dense structure effectively blocks the corrosion of the coating by environmental media, maintaining interfacial stability. After silicon dioxide deposition, it is cured at 100°C for 1 hour to improve its overall performance (such as film density, replenishing oxygen vacancies that may exist during sputtering, eliminating residual internal stress, reducing film surface roughness, and improving its transmittance in the visible light region).

[0034] Furthermore, the thickness of the antifouling layer is 10nm-20nm.

[0035] Specifically, the antifouling layer is formed by a fluorinated coating liquid, and its application on the antireflective layer can enhance the durability of the membrane surface.

[0036] The present invention will be further described in detail below with reference to specific embodiments.

[0037] Example 1

[0038] A 50µm thick PET substrate was selected, and a 15nm thick TiO2 layer was sputtered onto its surface using magnetron sputtering. Then, an ITO layer (indium oxide:tin oxide = 90:10) with a thickness of 50nm was sputtered. Following this, a 5nm thick SiO2 layer was sputtered. After curing, an 80nm thick antireflective layer was coated onto the surface using wire rod coating. The coating was first thermo-cured (80℃, 1.5min), and then UV-cured at an energy of 400mJ / cm². 2 The material is then photocured and then coated with a 15nm thick antifouling layer using a wire rod, and cured at 80°C for 24 hours.

[0039] Example 2

[0040] A 50µm thick PET substrate was selected, and a 15nm thick TiO2 layer was sputtered onto its surface using magnetron sputtering. Then, an ITO layer (indium oxide:tin oxide = 90:10) with a thickness of 300nm was sputtered. Following this, a 5nm thick SiO2 layer was sputtered. After curing, a 98nm thick antireflective layer was coated onto the surface using wire rod coating. The coating was first thermo-cured (80℃, 1.5min), and then UV-cured at an energy of 400mJ / cm². 2The material is then photocured and then coated with a 15nm thick antifouling layer using a wire rod, and cured at 80°C for 24 hours.

[0041] Comparative Example 1

[0042] A 50µm thick PET substrate was selected, and a 15nm thick TiO2 layer was sputtered onto its surface using magnetron sputtering. Then, an ITO layer (indium oxide:tin oxide = 90:10) with a thickness of 30nm was sputtered. Following this, a 5nm thick SiO2 layer was sputtered. After curing, an 80nm thick antireflective layer was coated onto the surface using wire rod coating. The coating was first thermo-cured (80℃, 1.5min), and then UV-cured at an energy of 400mJ / cm². 2 The material is then photocured and then coated with a 15nm thick antifouling layer using a wire rod, and cured at 80°C for 24 hours.

[0043] Comparative Example 2

[0044] A 50µm thick PET substrate was selected, and a 15nm thick TiO2 layer was sputtered onto its surface using magnetron sputtering. Then, an ITO layer (indium oxide:tin oxide = 90:10) with a thickness of 500nm was sputtered. Following this, a 5nm thick SiO2 layer was sputtered. After curing, an 80nm thick antireflective layer was coated onto the surface using a wire rod coating method. The coating was first thermo-cured (80℃, 1.5min), and then UV-cured at an energy of 400mJ / cm². 2 The material is then photocured and then coated with a 15nm thick antifouling layer using a wire rod, and cured at 80°C for 24 hours.

[0045] The heat-insulating and anti-reflection functional films in the examples and comparative examples were tested. The total light transmittance TT was measured by a haze meter, the reflectance R was measured by an Olympus reflectance meter, and the transmittance T was measured by a spectrophotometer. The results are shown in Table 1.

[0046] Table 1 Test data of heat insulation and anti-reflection functional film

[0047]

[0048] As can be seen from the above data, the transmittance of ITO in the infrared band gradually decreases as the thickness of ITO increases. However, when the thickness of ITO reaches 500nm, its transmittance in the visible light region drops to 80.46%. When the thickness of ITO is 30nm, although the transmittance in the visible light region is relatively high, the effect of blocking infrared light is greatly reduced.

[0049] ITO is a highly doped n-type semiconductor whose infrared transmittance is highly correlated with the concentration of free electrons (n). e Closely related. According to the Drude model, the absorption coefficient (α) of free carriers to infrared light is... FCA It is inversely proportional to the square of the carrier concentration and the incident light frequency: As the film thickness increases, the total number of free carriers increases, causing more infrared light to be absorbed when it passes through the film, thus reducing transmittance.

[0050] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A heat-insulating and anti-reflective functional membrane, characterized in that, It includes a substrate layer, a titanium dioxide layer, an indium tin oxide layer, an underlayer, and an anti-reflection layer, which are stacked sequentially. The refractive index of the indium tin oxide layer is 1.8-2.0, and the refractive index of the antireflective layer is 1.40-1.

45.

2. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The thickness of the indium tin oxide layer is 50nm-300nm.

3. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The thickness of the antireflective layer is 80nm-100nm.

4. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The antireflective layer is an acrylic resin layer.

5. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The thickness of the titanium dioxide layer is 10nm-20nm.

6. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The base layer is a silicon dioxide layer.

7. The heat-insulating and anti-reflective functional membrane according to claim 6, characterized in that, The thickness of the substrate layer is 10nm-20nm.

8. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The anti-reflective layer is further provided on the side opposite to the base layer, and the thickness of the anti-fouling layer is 10nm-20nm.

9. The heat-insulating and anti-reflective functional membrane according to claim 1, characterized in that, The substrate layer is a PET layer with a thickness of 23μm-125μm.

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