Display film material and method for manufacturing the same

Abstract

The present invention relates to a display film material and a method for manufacturing the same. The display film material includes a substrate and a light-modulating layer provided on the substrate. The substrate is an optically transparent material, and the light-modulating layer is formed by alternately stacking a low refractive index material and a high refractive index material. The difference in refractive index between the low refractive index material and the high refractive index material is greater than 0.4. After light rays act through the light-modulating layer and the substrate, the visible light transmittance is 90% or more, the near-infrared blocking rate reaches a maximum of 80% or more, and the transmittance is high at 940-1000 nm. The mid-infrared emissivity reaches 90% or more, ultimately achieving a temperature reduction effect of 3-8 degrees Celsius.

Description

Technical Field

[0001] The present invention relates to a film, and particularly to a display film material and a method for manufacturing the same.

Background Art

[0002] With the increase in the global population and the development of society, the problem of global warming is becoming increasingly serious, which also increases the demand for cooling energy consumption. Conventional active cooling means are based on a compression cooling system, which consumes a large amount of electric power and emits a large amount of carbon dioxide. On the other hand, refrigerants such as freon used in the compression cooling system destroy the ozone layer and cause serious environmental problems. Radiative cooling, which is significantly different from conventional cooling means, is a passive cooling method that releases heat to the cold universe by thermal radiation. The Earth's atmosphere has different transmittances for electromagnetic waves of different wavelengths, and the transmittance for electromagnetic waves in the wavelength range of 8 - 13 μm is extremely high, which is so-called the "atmospheric window". Therefore, an excellent radiative cooling surface must have as high an emissivity as possible in the 8 - 13 μm wavelength range and strongly reflect sunlight (0.3 - 2.5 μm), thereby realizing self-cooling without consuming energy. As described above, radiative cooling technology can save energy and alleviate problems such as the greenhouse effect and environmental pollution caused by conventional cooling.

[0003] With the development of nanophotonics and advanced manufacturing technologies, photonic crystals and metamaterials have been first applied to radiative cooling materials. Nanophotonic crystals refer to nanophotonic materials having various layered structures and metasurface structures formed by processing a plurality of semiconductor materials through coating processes such as magnetron sputtering and electron beam evaporation or micro-nano processing processes, thereby realizing selective high emissivity in the mid-infrared specific wavelength range.

[0004] While the radiation spectra of common materials are typically broad, it is possible to design heat sources with controllable narrowband radiation spectra using photonic materials, which is particularly needed in radiative cooling. Currently, many nanostructured materials are being applied to radiative cooling. However, current radiative cooling materials are mostly used in outdoor buildings such as walls and roofs, with fewer applications in display devices. This is because display devices have higher spectral requirements for radiative cooling materials. [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a radiative cooling film for use in display devices, particularly a radiative cooling film for use in display devices with integrated sensors. Based on this object, the present invention provides a display film material which satisfies high visible light transmittance, high near-infrared reflectance, and high mid-infrared emissivity through the design of selected materials and structure. [Means for solving the problem]

[0006] The technical solution adopted by the present invention is as follows: A display film material comprising a substrate and a light-modulating layer provided on the substrate, wherein the substrate has a visible light absorptance of <5% in the 400-780 nm range, preferably no absorption, and a transmittance of >90%, and a near-infrared light absorptance of <5% in the 900-1100 nm wavelength range, preferably no absorption, and may be an organic or inorganic material, a flexible or rigid material, preferably a mixture of one or more materials from Glass, PET, PC, PMMA, PE, and COP. The light-modulating layer is used to adjust the optical properties of the film material, compensate for any deficiencies in the optical properties of the substrate, and enhance the operability of the material, and the light-modulating layer is formed by depositing a plurality of organic and / or inorganic materials. After the light rays act through the light-modulating layer and the substrate, the transmittance in the visible light wavelength range of 400 to 780 nm is greater than 80%, preferably greater than 90%, the emissivity in the mid-infrared wavelength range of 8 to 13 μm is greater than 85%, preferably greater than 95%, the reflectance in the near-infrared wavelength range of 900 to 1400 nm is greater than 70%, and the transmittance in the 940 to 1100 nm range is >70%.

[0007] More preferably, the substrate has an absorptivity of less than 1% and a transmittance of more than 90% in the 400-780 nm wavelength range, and an absorptivity of less than 1% in the 900-1400 nm wavelength range; the light-modulating layer is formed by alternately stacking a low refractive index material and a high refractive index material, and the difference in refractive index between the low refractive index material and the high refractive index material is greater than 0.5; and after the light rays act through the light-modulating layer and the substrate, the transmittance in the 400-780 nm wavelength range is greater than 90%, the emissivity in the 8-13 μm wavelength range is greater than 85%, the reflectance in the 900-1400 nm wavelength range is greater than 80%, and the transmittance in the 940-1000 nm wavelength range is greater than 90%.

[0008] The light-modulating layer in this invention is formed by laminating at least two types of materials, and the difference in refractive index between the two types of materials is 0.4 or more, preferably 0.5 or more, and more preferably 0.5 to 0.8. Among these two types of materials, the one with the higher refractive index is called the high refractive index material, and the one with the lower refractive index is called the low refractive index material. The high refractive index material and the low refractive index material are arranged in alternating layers, and by alternating lamination of high and low refractive index materials, light in different wavelength ranges can be interfered with, selectively transmitted or reflected, and spectral adjustment can be achieved. When the difference in refractive index between the high refractive index material and the low refractive index material is 0.4 or more, by performing admittance matching interference of multiple layer films, light in the 400 to 780 nm wavelength range and the 940 to 1100 nm wavelength range has a refractive index of 1 close to that of air, and high transmittance can be achieved in this wavelength range. In the 900 to 1400 nm (excluding 940 to 1100 nm) wavelength range, the refractive index has a value of ∞ far from that of air, so high reflectance can be achieved in this wavelength range.

[0009] The number of layers of the high refractive index material and the number of layers of the low refractive index material may be the same or different, and the high refractive index material may be one type of material or a combination of multiple types of materials. Similarly, the low refractive index material may be one type of material or multiple types of materials. Preferably, the present invention includes at least two layers of material within a thickness range of 25 nm to 500 nm, and the difference in refractive index between these two layers of materials is 0.5 to 0.8. To explain in more detail, in the case of a film layer thinner than the preferred thickness, the following problems occur during the processing process: (1) Film uniformity decreases, the cooling effect and sensor sensitivity deteriorate, and in severe cases, it affects normal operation. (2) The stress in the film layer becomes unbalanced, stress cancellation with adjacent layers cannot be achieved, and this leads to problems such as film cracking. (3) The effect of errors is amplified during the normal processing process, and it becomes impossible to control the spectral deviation with high precision. On the other hand, in the case of a film layer thicker than the preferred thickness, localized film layer stress is too large, which tends to cause problems such as waste of film material, poor appearance, and an increased equipment failure rate. The refractive index difference between the two layers of materials is preferably 0.5 to 0.8. This refractive index difference ensures a sufficient refractive index difference, achieves an excellent spectral adjustment effect with a small number of layers, and helps in selecting appropriate materials during product processing. Furthermore, based on the film thickness of the present invention, if the refractive index difference is lower than this, the near-infrared reflectance decreases, affecting the cooling effect of radiative cooling.

[0010] In the light-modulating layer, multiple layers of low-refractive-index material and multiple layers of high-refractive-index material are provided, with a preferred total number of layers being 38 to 50. If the number of layers is lower than this, the optical effect in each wavelength range cannot be adjusted, and if the number of layers is higher than this, the bonding strength between the light-modulating layer and the substrate will be poor, and the light transmittance will also decrease. Each low-refractive-index material and each high-refractive-index material is a metal oxide or a non-metal oxide, and the transmittance of each low-refractive-index material and each high-refractive-index material in the visible light wavelength range within a nanometer thickness range is higher than 90%. Each low-refractive-index material may be the same or different, and is preferably a combination of one or more selected from TiO2 [titanium oxide], Ti3O5 [titanium pentoxide], ZrO2 [zirconium oxide], CeO2 [cesium oxide], HfO2 [hafnium oxide], Nb2O5 [niobium pentoxide], and Ta2O5 [tantalum pentoxide]. Each high refractive index material may be the same or different, and preferably a combination of one or more selected from SiO2 (silicon dioxide), SiO (silicon monoxide), MgF2 (magnesium fluoride), Al2O3 (alumina), PRO4 (a mixture of silicon and aluminum), PRO6 (a mixture of silicon and aluminum), cryolite, and AlF3 (aluminum fluoride). The above high refractive index materials do not absorb light in the spectral wavelength range that needs tuning, which is advantageous for enhancing the phototuning effect.

[0011] The thickness settings of high-refractive-index and low-refractive-index materials affect the optical control effect of the material layer. In this invention, the preferred thickness value for high-refractive-index materials is 10 to 200 nm, and the preferred thickness value for low-refractive-index materials is 20 to 300 nm. Under this thickness combination, uniformity of the material layer can be ensured, high film stress can be prevented, the possibility of film cracking can be reduced, and furthermore, beams in each wavelength range can be sensitively distinguished, the paths of beams in each wavelength range can be adjusted, and visible light, near-infrared light, and mid-infrared light can be effectively distinguished. In addition, based on optical interference, transmittance in the visible light wavelength range and reflectance in the near-infrared wavelength range can be improved.

[0012] In the present invention, the alternating lamination method of high refractive index materials and low refractive index materials is not limited to adjacent alternating lamination, but may also involve laminating multiple layers of low refractive index materials followed by high refractive index materials, that is, the lamination method may be (1) or (2). (1) 1 layer of high refractive index material - 1 layer of low refractive index material - 1 layer of high refractive index material..., (2) 2 layers of high refractive index material - 1 layer of low refractive index material - 1 layer of high refractive index material - 2 layers of low refractive index material.... In method (2), the adjustability of the wavelength range can be increased, and light in different wavelength ranges can exhibit different optical properties.

[0013] The light-modulating layer in this invention may be deposited directly onto the substrate, or a transition layer may be deposited on the substrate first. The presence of a transition layer is advantageous in strengthening the bonding stability between the light-modulating layer and the substrate. Preferably, the transition layer is an organic material, hereinafter referred to as the first organic layer, and more preferably SA, RA, SHA, phthalocyanine-based organic compounds, etc. SA, RA, and SHA are organic material products with model numbers SA, RA, and SHA from Ceko and Nano Primer in Korea. When SA, RA, SHA, or phthalocyanine-based organic compounds are used as the first organic layer, there is no light absorption in the visible light wavelength range, the influence on the transmittance of the film layer in the visible light wavelength range is reduced, and it has excellent impact resistance, improving the bonding stability between the substrate and the light-modulating layer. A second organic layer is provided above the light-modulating layer, i.e., on the side opposite the substrate of the light-modulating layer. The second organic layer is a hydrophobic, oleophobic organic material, preferably a fluorine-containing organic material, and more preferably an AF (fingerprint-resistant film). The AF has an extremely low surface energy and can achieve an automatic surface cleaning function. The provision of the second organic layer makes the film material of the present invention less susceptible to contamination by water and oil stains during use, thus fulfilling the role of automatic cleaning. Furthermore, the AF has excellent spectral adjustment performance. Preferably, the thickness of the AF layer is (10-40) nm. If the AF thickness is less than 10 nm, it is difficult to form a dense film layer on the surface, and the hydrophobic effect is inferior. If it exceeds 40 nm, oil stains will form on the surface, and it will not be able to bond effectively with other film layers. If the film layer is too thick, it will cause material waste and surface scratches.

[0014] The second organic layer must be deposited onto the film by a resistance heating deposition process. The current is preferably (30-200) mA, and the coating rate is (3-9) A / s. If the deposition rate is too low, the kinetic energy of the AF material will be insufficient, resulting in a low film thickness and poor film layer density. If the deposition rate is too high, the uniformity of the product will be poor.

[0015] Preferably, the second organic layer is provided on the substrate, specifically on the side of the substrate opposite to the light-modulating layer, so that when the film is attached, the light-modulating layer contacts the display screen via AB glue, and the second organic layer is positioned on the surface. This arrangement enhances the hydrophobicity and abrasion resistance of the AF material.

[0016] In one preferred embodiment, the high refractive index material in the present invention is TiO2, the low refractive index material is SiO2, the light-modulating layer is made up of TiO2 and SiO2 layered alternately, totaling 41 layers, the first organic layer is SHA, the second organic layer is AF, and the particle size of both the high refractive index material and the low refractive index material is (1-3) mm. The production process is as follows. The coating temperature for the light-modulating layer is set to 100°C, and the vacuum level is set to 1*10. -3 The setting is Pa. The energy for SiO2 ion source coating acceleration is 170V, 6A, and the energy for TiO2 ion source coating acceleration is 200V, 8A. SHA is processed using the EB (electron beam deposition) method with a current of 10-60mA. AF is processed using the resistance heating deposition process with a heating current of 100-200mA.

[0017] [Table A]

[0018] As a preferred embodiment, the high refractive index material in the present invention is TiO2 (n = 2.35 @ 500 nm), the low refractive index material is SiO2 (n = 1.46 @ 550 nm) & MgF2 (n = 1.38 @ 550 nm), a total of 41 layers of the high refractive index material and the low refractive index material are provided, the particle sizes of the high refractive index material and the low refractive index material are both 1 to 3 mm, the first organic layer is SHA, the second organic layer is AF, and the manufacturing process adopted is as follows. The coating temperature is selected to be 150 °C, and the degree of vacuum is 1.5 * 10 -3 is set. The energy for promoting SiO2 ion source coating is 200 V, 7 A, the energy for promoting TiO2 ion source coating is 250 V, 7.5 A, SHA is processed by the EB method with a current of 10 - 60 mA. AF is processed by a resistance heating evaporation process with a heating current of 100 - 200 mA.

[0019]

Table B

[0020] As a preferred embodiment, the high refractive index material in the present invention is Ta2O5 (n = 2.32 @ 500 nm), the low refractive index material is SiO2 (n = 1.46 @ 550 nm), the total number of layers of the high refractive index material and the low refractive index material is 49 layers, the particle sizes of the high refractive index material and the low refractive index material are both 1 - 3 mm, the first organic layer is SA, the second organic layer is AF, and the manufacturing process adopted is as follows.

[0021] The coating temperature is selected to be 100 °C, and the degree of vacuum is 1 * 10 -3 is set. The energy for promoting SiO2 ion source coating is 170 V, 6 A, the energy for promoting Ta2O5 ion source coating is 200 V, 8 A, SA is processed by the EB method with a current of 10 - 60 mA. AF is processed by a resistance heating evaporation process with a heating current of 100 - 200 mA.

[0022]

Table C

Advantages of the Invention

[0023] The beneficial effects brought about by the present invention include the following. This film adjusts the spectral performance in different wavelength ranges through the structural design of a multi-layer film structure, and endows the film material in the present invention with the following performances. (1) High near-infrared blocking performance, (2) Without affecting the sensor sensing effect, (3) Effectively blocking other energy incidence in the solar light wavelength range, (4) Radiating heat in the form of electromagnetic waves to the natural cooling source in the universe through the thermal infrared wavelength range, and realizing the maximum radiation cooling effect.

[0024] The film material of the present invention alternately provides a high refractive index material and a low refractive index material, and utilizes the optical interference effect. By laminating different materials, the transmittance in the visible light wavelength range, the reflectance in the near-infrared wavelength range, and the emissivity in the mid-infrared wavelength range are improved, and finally the following performances are achieved. The visible light transmittance is 90% or more, the near-infrared blocking rate reaches up to 80% or more, the mid-infrared wavelength range emissivity reaches 90% or more, the transmittance in the wavelength range of 940 - 1000 nm is high, reaching 90% or more, and a temperature reduction effect of 3 - 8 degrees can be obtained.

[0025] The film material of the present invention can be stretched on almost any material surface, such as glass, walls, roofs, display devices of electronic equipment, etc., to reduce the temperature, and it is an effective tool for energy conservation and emission reduction. By adding an organic sealing layer on the surface of the film material, excellent anti-aging characteristics are imparted to the product, and excellent hydrophobic and antifouling performance and wear resistance performance during the use process are realized.

[0026] When the film material of the present invention is applied to a display device, the screen of a tablet display device, particularly a product such as a mobile phone, integrates a large number of sensors, including fingerprint sensors, Face ID sensors, distance sensors, ambient light sensors, and TOF sensors. The operating wavelengths of these sensors are mainly concentrated in the visible light or near-infrared wavelength range (generally 940 nm). The film material of the present invention can achieve high transmittance near 940 nm, thereby ensuring the sensitivity of the sensors.

[0027] Planck's law of thermal radiation: B(λ,T)=(2hc 2 / λ 5 Based on )*(1 / (e^(hc / λkT)-1)), B(λ,T) is the unit area and the radiant energy density within a unit wavelength range, λ is the wavelength, T is the absolute temperature, c is the speed of light, h is Planck's constant, and k is Lutzmann's constant. The operating temperature of products related to daily life is in the range of 30-70°C, and in particular, the operating temperature of display devices is usually in the range of 30-60°C, with the main wavelength range of their thermal radiation located in the atmospheric window region. By attaching the present invention to the screen cover glass of a display device, broad spectrum adjustment is achieved, blocking solar radiation heat, optimizing the operating wavelength of optical sensors (avoiding impact on operation), and improving the thermal radiation capability of the product in the 8-13 μm atmospheric window wavelength range. [Brief explanation of the drawing]

[0028] [Figure 1] This is a structural diagram of the film material in Example 1. [Figure 2] This shows the transmittance of the film before and after coating in Example 1. [Figure 3] This is the emissivity of the film material in Example 1. [Figure 4] These are the detected temperatures when a film is applied to the display, when a film is not applied to the display, and the ambient temperature. [Figure 5] This is a structural diagram of the film material in Example 2. [Modes for carrying out the invention]

[0029] The present invention will be described in more detail below with reference to the drawings and specific embodiments, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0030] Example 1 In this embodiment, the substrate for the film material was a steel film for commercial mobile phones. The high refractive index material in the light-modulating layer was TiO2 (n=2.35@500nm), and the low refractive index material was SiO2 (n=1.46@550nm). The light-modulating layer was obtained by an electron beam deposition system and consisted of a total of 39 layers. TiO2 layers, SiO2 layers, TiO2 layers...SiO2 layers, TiO2 layers were arranged sequentially from the substrate towards the substrate. The thickness of each layer and the coating rate are shown in Table 1, and the particle size of the high and low refractive index materials was selected to be 1-3 mm. SHA&AF was used for the organic layer. As shown in Figure 1, the structure of the film material consisted of a first organic layer deposited on the substrate and a second organic layer deposited on the back side of the substrate. The symbols 1 / 2 / 3...n in the drawing were the number of layers in the light-modulating layer.

[0031] The coating temperature for the light-modulating layer is set to 100°C, and the vacuum level is set to 1*10. -3 The energy for SiO2 ion source coating acceleration was 170V, 6A, and the energy for TiO2 ion source coating acceleration was 200V, 8A. SHA was processed using the EB method with a current of 10-60mA. AF was processed using a resistance heating deposition process with a heating current of 100-200mA.

[0032] [Table 1]

[0033] Both the original glass (steel film for commercial mobile phones) and the coated glass were tested.

[0034] 1. The reflectance of commercial glass and coated glass in the solar wavelength range was tested. The instrument used was a UV-vis-nir spectrophotometer (uv3600, Shimadzu) equipped with an integrating sphere model (ISR-3100), and the test range was (0.3-2.5) μm.

[0035] The reflectance of the glass before and after coating is shown in Figure 2. The results show that after adding the radiative cooling film of the present invention, the transmittance of the glass in the near-infrared wavelength range clearly decreased, dropping from 90% of the original glass to about 30%.

[0036] 2. The emissivity of commercial glass and coated glass in the mid-infrared wavelength range was tested. The instruments used were a Fourier transform infrared (FT-IR) spectrometer (Nicolet IS50, ThermoFisher), a gold integrating sphere (IntergatIR MIR, Pike), and a mercury-cadmium telluride detector. The emissivity of the glass before and after coating is shown in Figure 3. The results show that after adding the radiative cooling film of the present invention, the emissivity of the glass in the mid- and far-infrared wavelength range clearly improved, and in particular, in the atmospheric window (8-13 μm), it improved from an average of 0.8 or less for the original glass to 0.9 or more.

[0037] 3. The cooling effect of commercial glass and coated glass was tested. A temperature tester was placed in the coated glass, the original glass (attached to a commercial mobile phone under conditions where it operates continuously with a bright screen), and air. The temperature change under these three conditions was recorded simultaneously, with lower temperatures indicating a better cooling effect. The equipment used was a K-type, Omega thermocouple. The results are shown in Figure 4. Under outdoor conditions with an ambient temperature of approximately 30°C, the coated glass was able to lower the operating temperature of the mobile phone by 3-8°C, demonstrating a significant cooling effect.

[0038] 4. The hydrophobic properties of the coated glass were tested using a Theta contact angle tester (LSA100, LAUDA Scientific). The average static contact angle exceeded 115°, indicating excellent hydrophobic properties.

[0039] Example 2 In this embodiment, the substrate of the film material is tempered glass, the low refractive index material in the light-modulating layer is SiO2, and the high refractive index material is TiO2. The light-modulating layer is obtained by an electron beam deposition system and consists of a total of 36 layers, with particle sizes of 1-3 mm selected for the high and low refractive index materials. SHA&AF was adopted for the organic layer, and the post-coating structure, as shown in Figure 5, consists of a first organic layer deposited as a buffer transition layer between the light-modulating layer and the glass substrate, and a second organic layer deposited on top of the light-modulating layer.

[0040] The coating temperature was set to 150°C, and the vacuum level to 1.5*10 -3 The following settings were used. The energy for SiO2 ion source coating acceleration was 200V, 7A, and the energy for TiO2 ion source coating acceleration was 250V, 7.5A. SHA was processed using the EB method with a current of 10-60mA. AF was processed using a resistance heating deposition process with a heating current of 100-200mA.

[0041] [Table 2]

[0042] Both the original glass (steel film for commercial mobile phones) and the coated glass were tested.

[0043] 1. The reflectance of commercial glass and coated glass in the solar wavelength range was tested. The instrument used was a UV-vis-nir spectrophotometer (uv3600, Shimadzu) equipped with an integrating sphere model (ISR-3100), and the test range was (0.3-2.5) μm.

[0044] The reflectivity of the glass before and after coating showed that after adding the radiative cooling film of the present invention, the transmittance of the glass in the near-infrared wavelength range clearly decreased, dropping from 90% of the original glass to about 30%.

[0045] 2. The emissivity of commercial glass and coated glass in the mid-infrared wavelength range was tested. The instruments used were a Fourier transform infrared (FT-IR) spectrometer (Nicolet IS50, ThermoFisher), a gold integrating sphere (IntergatIR MIR, Pike), and a mercury-cadmium telluride detector. The emissivity results of the glass before and after coating showed that after adding the radiative cooling film of the present invention, the emissivity of the glass in the mid- and far-infrared wavelength range clearly improved. In particular, in the atmospheric window (8-13 μm), it improved from an average of 0.8 or less for the original glass to 0.9 or more.

[0046] 3. Using a chromatic aberration meter (HC-CR8W), a reflectivity test of the bonded screen was performed on the processed product, and the test reflectivity Y was set to approximately 1.8. A reflectivity test of the bonded screen was also performed on the original glass, and the test reflectivity Y was set to approximately 5.3. The processed product exhibited significant anti-reflective and anti-glare properties.

[0047] 4. The cooling effect of commercial glass and coated glass was tested. A temperature tester was placed in the coated glass, the original glass (attached to a commercial mobile phone under conditions where it operates continuously on a bright screen), and air. The temperature change under these three conditions was recorded simultaneously, with lower temperatures indicating a better cooling effect. The equipment used was a K-type, Omega thermocouple. Under outdoor conditions with an ambient temperature of approximately 30°C, the coated glass was able to lower the operating temperature of the mobile phone by 3-8°C, demonstrating a clear cooling effect.

[0048] 5. The hydrophobic properties of the coated glass were tested using a Theta contact angle tester (LSA100, LAUDA Scientific). The average static contact angle exceeded 115°, indicating excellent hydrophobic properties.

[0049] Example 3 In this embodiment, the substrate of the film material is tempered glass, the low refractive index material in the light-modulating layer is SiO2, and the high refractive index material is Ta2O5 (n=2.32@500nm). The light-modulating layer is obtained by an electron beam deposition system and consists of a total of 39 layers, arranged in the order of TA2O5 layer, SiO2 layer, TA2O5 layer, SiO2 layer...TA2O5 layer, SiO2 layer from the substrate closer to the substrate to the substrate further away. The particle sizes of the high and low refractive index materials were selected to be 1-3 mm. The first organic layer is made of SA and the second organic layer is made of AF, both being particulate materials. The first organic layer is provided between the light-modulating layer and the substrate material, and the second organic layer is provided on the opposite side of the light-modulating layer from the first organic layer.

[0050] The coating temperature is set to 100℃, and the vacuum level is set to 1*10. -3 The following settings were used. The energy for SiO2 ion source coating acceleration was 170V, 6A, and the energy for Ta2O5 ion source coating acceleration was 200V, 8A. SA was processed using the EB method with a current of 10-60mA. AF was processed using a resistance heating deposition process with a heating current of 100-200mA.

[0051] [Table 3]

[0052] Both the original glass (steel film for commercial mobile phones) and the coated glass were tested.

[0053] 1. The reflectance of commercial glass and coated glass in the solar wavelength range was tested. The instrument used was a UV-vis-nir spectrophotometer (uv3600, Shimadzu) equipped with an integrating sphere model (ISR-3100), and the test range was (0.3-2.5) μm.

[0054] According to the reflectivity of the glass before and after coating, the transmittance of the glass in the near-infrared wavelength range clearly decreased after adding the radiative cooling film of the present invention, dropping from 90% of the original glass to about 40%.

[0055] 2. The emissivity of commercial glass and coated glass in the mid-infrared wavelength range was tested. The instruments used were a Fourier transform infrared (FT-IR) spectrometer (Nicolet IS50, ThermoFisher), a gold integrating sphere (IntergatIR MIR, Pike), and a mercury-cadmium telluride detector. The emissivity of the glass before and after coating showed that after adding the radiative cooling film of the present invention, the emissivity of the glass in the mid- and far-infrared wavelength range clearly improved. In particular, in the atmospheric window (8-13 μm), it improved from an average of 0.8 or less for the original glass to 0.9 or more.

[0056] 3. The cooling effect of commercial glass and coated glass was tested. A temperature tester was placed in the coated glass, the original glass (attached to a commercial mobile phone under conditions where it operates continuously with a bright screen), and air. Temperature changes were recorded simultaneously under three conditions, with lower temperatures indicating better cooling effect. The equipment used was a K-type, Omega thermocouple. Under outdoor conditions with an ambient temperature of approximately 30°C, the coated glass was able to lower the operating temperature of the mobile phone by 3-6°C, demonstrating a clear cooling effect.

[0057] 4. The hydrophobic properties of the coated glass were tested using a Theta contact angle tester (LSA100, LAUDA Scientific). The average static contact angle exceeded 115°, indicating excellent hydrophobic properties.

[0058] The above embodiments are not limiting but merely illustrate the technical aspects of the present invention. While the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical aspects of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical aspects of the present invention.

Claims

1. A display film material, It includes a substrate and a light-modulating layer provided on the substrate, The substrate has an absorption rate of less than 5% and a transmittance of more than 80% in the 400-780 nm wavelength range, and an absorption rate of less than 5% in the 900-1400 nm wavelength range. The aforementioned light-modulating layer is formed by alternately stacking a low-refractive-index material and a high-refractive-index material, and the difference in refractive index between the low-refractive-index material and the high-refractive-index material is greater than 0.

5. A display film material characterized in that, after light rays act upon it by passing through the light-modulating layer and the substrate, the transmittance in the 400-780 nm wavelength range is greater than 80%, the emissivity in the 8-13 μm wavelength range is greater than 85%, the reflectance in the 900-1400 nm wavelength range is greater than 70%, and the transmittance in the 940-1000 nm range is greater than 80%.

2. The number of layers of the low refractive index material and the high refractive index material may be the same or different, the total number of spectral adjustment layers may be 28 to 50, the low refractive index material in each layer may have the same or different composition and the same or different thickness, and the high refractive index material in each layer may have the same or different composition and the same or different thickness. The display film material according to claim 1, characterized in that the light-modulating layer is provided directly or indirectly on the substrate.

3. The display film material according to claim 2, characterized in that the light-modulating layer is provided on the substrate via a first organic layer, the light absorption rate of the first organic layer in the 400 to 780 nm wavelength range is less than 5%, and the first organic layer is one or more selected from SA, RA, SHA, and phthalocyanine organic substances.

4. The spectral adjustment layer is where the high refractive index material is TiO ２ , Ti ３ O ５ , ZrO ２ , CeO ２ , HfO ２ , Nb ２ O ５ , Ta ２ O ５ and is one or more selected from The low refractive index material is SiO ２ SiO, MgF ２ Al ２ O ３ PR0 ４ PR0 ６ Cryolite, AlF ３ It must be one or more selected from, The thickness of the low refractive index material is 20-300 nm, The display film material according to claim 1, characterized in that it satisfies at least one combination of the following: the thickness of the high refractive index material is 10-200 nm.

5. A second organic layer is provided on the side of the substrate opposite to the light-modulating layer, or a second organic layer is provided on the side of the light-modulating layer opposite to the substrate, and the second organic layer is The second organic layer is a fluorine-containing organic material, The second organic layer is AF, The contact angle of the second organic layer is greater than 115°, The thickness of the second organic layer is 10-40 nm, The display film material according to claim 1, characterized in that the second organic layer is deposited by a resistance heating deposition process, and satisfies at least one combination of the following: a preferred range of resistance heating deposition current is (30-200) mA and a coating rate is (3-9) A / s.

6. A first organic layer and a second organic layer are provided on both sides of the substrate, and the optical adjustment layer is provided on the side where the first organic layer is provided, and TiO in the optical adjustment layer ２ and SiO ２ This is because 41 to 49 layers are arranged in an alternating pattern, and TiO ２ The layer thickness is (15-300) nm, and SiO ２ The display film material according to claim 1, characterized in that the layer thickness is (10-200) nm, the first organic layer is SHA, and the second organic layer is AF.

7. The display film material according to claim 1, characterized in that, in the thickness direction of the light-modulating layer, at least two layers of material having a refractive index difference of 0.5 to 0.8 are provided within any one thickness interval of 25 nm to 500 nm.

8. The display film material according to claim 1, characterized in that, after passing through the light-modulating layer and the substrate, the transmittance in the visible light wavelength range is greater than 90%, the emissivity in the mid-infrared wavelength range is greater than 95%, the reflectance in the near-infrared wavelength range is greater than 80%, and the transmittance at 940 nm is greater than 90%.

9. The display film material according to claim 1, characterized in that the material and thickness of each layer in the spectral adjustment layer are set as follows. Table 4

10. TiO ２ High refractive index material, SiO ２ The TiO is used as a low refractive index material. ２ and SiO ２ All of these are deposited by electron beam evaporation, the coating temperature is selected to be (100-150)°C, and the vacuum level is 1*10 －３ ~1.5*10 －３ Set to SiO ２ The energy required to accelerate ion source coating is (170-200) V, (6-7) A, and TiO ２ The energy required to accelerate ion source coating is (200-250) V, (7.5-8) A, and TiO ２ The particle size is 1-3 mm, and SiO ２ The method for producing a display film material according to claim 1, characterized in that the particle size of the material is 1-3 mm.

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