Method for preparing a composite film layer and optical panel

Abstract

The application provides a method for preparing a composite film layer and an optical panel, so as to improve the bonding force between the composite film layer and a glass substrate, thereby prolonging the service life of the composite film layer and the optical panel. The method comprises the following steps: attaching a target material with a transmittance less than a first threshold to the surface of a glass substrate to form a first film layer; wherein the decomposition temperature of the target material is greater than or equal to the melting temperature of the glass substrate; coating a target sol containing SiO2 colloidal particles and TiO2 colloidal particles on the surface of the first film layer to obtain a second film layer; and irradiating the surface of the second film layer with laser energy at the decomposition temperature of the target material, so that the first film layer is decomposed by heat, and the surface of the glass substrate is fused with the second film layer in a molten state to obtain the composite film layer.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a method for preparing a composite film layer and an optical panel. Background Technology

[0002] For surveillance equipment and other camera devices, the cleanliness of their transparent windows directly affects the clarity of the captured images and videos. However, for camera devices deployed outdoors, especially in open-air environments, their transparent windows are more susceptible to environmental factors such as dirt, dust accumulation, and fogging, which can negatively impact the captured footage.

[0003] To address this, current methods primarily employ high-temperature tempering or a combination of PEVCD (plasma-enhanced chemical vapor deposition) to coat the surface of transparent windows, mitigating the problem of unclear images caused by dust accumulation. However, the films prepared using these methods suffer from reliability issues; when the device is located outdoors, they are susceptible to detachment due to weather and other factors. Summary of the Invention

[0004] This application provides a method for preparing a composite film and an optical panel to improve the adhesion between the composite film and the glass substrate, thereby extending the service life of the composite film and the optical panel in which the composite film is located.

[0005] Firstly, embodiments of this application provide a method for preparing a composite film, comprising:

[0006] A target material with a light transmittance less than a first threshold is attached to the surface of a glass substrate to form a first film layer; wherein the decomposition temperature of the target material is greater than or equal to the melting temperature of the glass substrate;

[0007] A target sol containing SiO2 colloidal particles and TiO2 colloidal particles is coated onto the surface of the first film layer to obtain a second film layer;

[0008] The laser is used to irradiate the surface of the second film layer at the decomposition temperature of the target material, so that the first film layer is thermally decomposed, and the surface of the glass substrate fuses with the second film layer in a molten state to obtain the composite film layer.

[0009] In one possible implementation, the thickness of the first film layer is 0.03-0.07 mm; and the thickness of the second film layer is 120-150 nm.

[0010] One possible implementation involves coating a target sol containing SiO2 colloidal particles onto the surface of the first film layer before obtaining the second film layer, including:

[0011] The first SiO2 sol was prepared in a reaction system containing an acidic catalyst;

[0012] A second SiO2 sol was prepared in a reaction system containing an alkaline catalyst.

[0013] The first SiO2 sol after aging and the second SiO2 sol after aging are mixed to obtain a SiO2 sol containing the SiO2 colloidal particles.

[0014] In one possible implementation, the volume ratio between the second SiO2 sol and the first SiO2 sol is (3.5-4.0):1.

[0015] In one possible implementation, the target sol includes a soluble silver salt; before coating the target sol containing SiO2 colloidal particles and TiO2 colloidal particles onto the surface of the first film layer to obtain the second film layer, the method further includes:

[0016] SiO2 sol and TiO2 sol were mixed and aged.

[0017] A solution containing soluble silver salt is added to the aged sol to obtain the target sol; wherein the concentration of the solution is 0.2-0.4 mol / L.

[0018] One possible implementation, wherein the first film layer is obtained by attaching a target material with a light transmittance less than a first preset value to the surface of a glass substrate, includes:

[0019] The target material is dissolved in an organic solvent to obtain a first organic solution;

[0020] The first organic solution is coated onto the surface of the glass substrate and dried to allow the organic solvent to evaporate, thus obtaining the first film layer.

[0021] In one possible implementation, the target material is a fluorinated polyether material, and the organic solvent is selected from one or more of fluorinated hydrocarbon solvents, ketone solvents, and aromatic hydrocarbon solvents.

[0022] One possible implementation, wherein the laser energy irradiates the surface of the second film layer at the decomposition temperature of the target material to thermally decompose the first film layer, and the surface of the glass substrate fuses with the second film layer in a molten state to obtain the composite film layer, includes:

[0023] Using a laser source with an average power of 400-800 nanojoules, and with the center-to-center distance between two adjacent laser points greater than the diameter of the laser point, and each laser point remaining on the surface for 5-8 seconds, the second film layer is laser-written to obtain the composite film layer containing papillae; wherein the depth-to-diameter ratio of the papillae is (0.8-1.5):1.

[0024] In one possible implementation, the difference between the center distance of two adjacent laser points and the diameter of the laser point is 3-10 μm.

[0025] One possible implementation involves laser direct writing on the surface of the second film layer, with the laser source positioned such that the distance between any two adjacent laser points is greater than or equal to 5 μm, and each laser point remains stationary for 5-8 seconds, to obtain the target film layer containing the papillary array, comprising:

[0026] The laser beam from the laser source is split to form a laser point cloud on the surface of the second film layer. Laser direct writing is then performed to form a papillary array corresponding to the laser point cloud, thereby obtaining the target film layer.

[0027] Secondly, embodiments of this application provide an optical panel, including:

[0028] The composite film layer prepared by the method described in the first aspect and any possible implementation thereof.

[0029] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects:

[0030] In this embodiment, a first film layer with low light transmittance is provided between the second film layer and the glass substrate, making it easier to focus laser energy on the surface of the second film layer. This enables the transparent glass substrate and the pre-made second film layer to fuse together under laser irradiation, significantly improving the bonding force between the composite film layer substrates and enhancing the reliability of the composite film layer.

[0031] Furthermore, by utilizing lasers of appropriate energy and laser dot spacing, papillae are formed on the surface of the composite membrane. This not only provides excellent anti-reflection properties but also increases the surface energy and hydrophilicity of the membrane by increasing the contact area between the membrane and air or water mist. Correspondingly, the increased surface energy and hydrophilicity facilitate the spread of water droplets (beads) on the membrane surface, creating a fogging or water-repellent beading effect, which greatly enhances image clarity. Simultaneously, the improved hydrophilicity helps water droplets spread evenly on the membrane surface, effectively isolating dust and oil from the air. This water spread on the membrane surface also more easily penetrates between contaminants and the membrane, thus removing contaminants as the water droplets detach (e.g., due to wind).

[0032] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The purposes and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit this disclosure. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 A schematic flowchart illustrating a method for preparing a composite film layer according to an embodiment of this application;

[0035] Figure 2 A schematic flowchart of a method for preparing SiO2 sol provided in an embodiment of this application;

[0036] Figure 3 A schematic diagram illustrating laser irradiation of the surface of a second film layer, provided as an embodiment of this application;

[0037] Figure 4 This is a schematic diagram showing the formation of papillae on the surface of a composite film layer after laser irradiation, as provided in an embodiment of this application. Detailed Implementation

[0038] To address the current issue of insufficient reliability of surface films on transparent windows, this application provides a method for preparing a composite film: a first film layer with low light transmittance and high melting and boiling points is placed between a silica sol coating layer and a transparent substrate to ensure that laser energy does not penetrate the glass substrate but is instead concentrated on the surface of the silica sol coating layer (i.e., the second film layer). This causes the first film layer to pyrolyze under laser energy, while the silica in the second film layer undergoes a polycondensation reaction with the silica in the glass substrate and melts into one, thereby effectively improving the reliability of the surface film layer on the transparent window.

[0039] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0040] The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive protection. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. The term "multiple" in this application can mean at least two, for example, two, three, or more, and the embodiments of this application do not impose limitations.

[0041] Please refer to Figure 1 This application proposes a method for preparing a composite film to improve the density of the film on the surface of a glass substrate. The method specifically includes the following steps:

[0042] Step 101: Attach the target material with a light transmittance of less than the first threshold to the surface of the glass substrate to form the first film layer.

[0043] The decomposition temperature of the target material is greater than or equal to the melting temperature of the glass substrate.

[0044] Specifically, to ensure that the laser energy in step 103 can be focused and to prevent penetration of the glass substrate, the thickness of the first film layer is 0.03-0.07 mm. The first threshold can be, for example, 40%, 30%, or lower.

[0045] This application does not limit the specific SiO2 content in the glass substrate; for example, it can be 50% or higher. The light transmittance of the glass substrate is at least greater than 30%. The light transmittance can be adjusted according to its specific application scenario; for example, it can be adjusted to 70% or higher.

[0046] To allow the target material to adhere to the surface of the glass substrate, it can be coated by dissolving it in an organic solvent. The formation of the first film layer is described in detail below:

[0047] First, the target material can be dissolved in an organic solvent to obtain a first organic solution. The target material can be a fluorinated polyether material, such as a fluorinated polyarylether nitrile with a melting and boiling point of 550-700℃. The organic solvent is selected from one or more of fluorinated hydrocarbon solvents, ketone solvents, and aromatic hydrocarbon solvents.

[0048] Fluorinated hydrocarbon solvents include perfluoropropane and / or perfluoroisopropane. Ketone solvents include at least one of acetone, methyl ketone, dimethylformamide, and N-methylpyrrolidone. Aromatic hydrocarbon solvents include at least one of xylene, toluene, and benzene.

[0049] Furthermore, based on the total mass of the first organic solution, the solute content in the first organic solution is greater than 90%, preferably greater than or equal to 99%. To accelerate dissolution, the organic solvent can be heated upon addition of the target material, followed by stirring using a stirring device at a preset speed. The heating temperature can be 200°C.

[0050] Then, the first organic solution is coated onto the surface of the glass substrate, allowed to flow naturally and then dry to allow the organic solvent to evaporate, thus obtaining the first film layer. Specifically, it can be first dried at room temperature to allow the first film layer to initially form, and then heated at high temperature to allow the organic solvent to evaporate.

[0051] The high-temperature heating method can be: placing the first film layer, including the glass substrate, in an oven and heating it to 220°C in multiple stages.

[0052] Step 102: Coat the surface of the first film layer with the target sol containing SiO2 colloidal particles and TiO2 colloidal particles to obtain the second film layer.

[0053] Specifically, the thickness of the second film is 120-150 nm.

[0054] The target sol is obtained by mixing SiO2 sol and TiO2 sol and then aging the mixture.

[0055] The solid content of SiO2 sol is 2%-3%, and the solid content of TiO2 sol is 0.8%-1% of the solid content of SiO2 sol.

[0056] The volume ratio of SiO2 sol to TiO2 sol is greater than or equal to 9:1, for example, 10:1. The mixing time can be 2 hours, which can be achieved by stirring. The aging time can be 7 days in a constant temperature bath at 0°C.

[0057] The average particle size of the SiO2 colloidal particles is 10-20 nm, and the average particle size of the TiO2 colloidal particles is 50-100 nm. This average particle size can be obtained by measuring and calculating the average value of N randomly selected particles in the SEM image. N is an integer greater than or equal to 100. The particle size of each particle is the average of the length of the longest line segment in the SEM image whose endpoint is located at the edge of the oxide particle and passes through the geometric center of the oxide particle, and the length of the shortest line segment whose endpoint is located at the edge of the oxide particle and passes through the aforementioned geometric center.

[0058] The target solvent obtained in this way consists mostly of core-shell nanoparticles with TiO2 colloidal particles as the core and SiO2 colloidal particles coated on the surface, and a small portion consists of SiO2 colloidal particles that are not coated.

[0059] The above-mentioned TiO2 sol can be prepared by adding anhydrous ethanol, deionized water, concentrated hydrochloric acid and tetrabutyl titanate into a flat-bottomed flask at a preset molar ratio, reacting at a constant temperature and then aging.

[0060] The temperature for the above-mentioned isothermal reaction can be 25-35℃, and the reaction time can be, for example, 2 hours. The aging conditions can be: aging in a sealed glass container in a constant temperature bath at 30℃ for 3 days.

[0061] Furthermore, to prevent the aggregation of SiO2 colloidal particles in the sol, which would significantly reduce light transmittance and hydrophilicity, in some embodiments, the aforementioned SiO2 colloidal particles are obtained by mixing a first SiO2 sol catalyzed by a catalyst and a second SiO2 sol catalyzed by an alkaline catalyst. Detailed explanation follows; please refer to [link / reference]. Figure 2 :

[0062] Step 201: Prepare the first SiO2 sol in a reaction system containing an acidic catalyst.

[0063] Specifically, anhydrous ethanol, hydrochloric acid, deionized water, and TEOS (tetraethoxysilane) in a preset molar ratio can be mixed and reacted at a constant temperature of 30°C for 6-7 hours to obtain the product.

[0064] Step 202: Prepare a second SiO2 sol in a reaction system containing an alkaline catalyst.

[0065] Specifically, the mixture of anhydrous ethanol, concentrated ammonia, deionized water, and TEOS (tetraethoxysilane) in a predetermined molar ratio can be reacted at a constant temperature of 25-35℃ for 2-4 hours to obtain the final product.

[0066] Step 203: Mix the aged first SiO2 sol and the aged second SiO2 sol to obtain a SiO2 sol containing the aforementioned SiO2 colloidal particles.

[0067] Specifically, the aged first SiO2 sol can be obtained by placing the first SiO2 sol obtained from the isothermal reaction in step 201 in a 30°C isothermal bath for 3 to 7 days.

[0068] The aged second SiO2 sol can be obtained by placing the second SiO2 sol obtained from the isothermal reaction in step 202 in a 30℃ isothermal bath for 3-7 days, and then refluxing at a temperature of about 80℃ for 6-24 hours to remove ammonia.

[0069] Further, the first SiO2 sol after aging and the second SiO2 sol after aging are mixed and stirred at a preset volume ratio for 2-3 hours to obtain a SiO2 sol containing the SiO2 colloidal particles.

[0070] The volume ratio between the second SiO2 sol and the first SiO2 sol can be (3.5-4.0):1.

[0071] To further enhance the wavelength range of the absorbable spectrum of the second film layer, thereby broadening the application scenarios of the hydrophilic self-cleaning function of the composite film layer obtained in step 103 and making it no longer limited to ultraviolet light irradiation conditions, the target sol also includes a soluble silver salt, such as silver nitrate.

[0072] Before step 102, the SiO2 sol and TiO2 sol can be mixed and aged. Then, a solution containing soluble silver salts is added to the aged sol to obtain the target sol. The concentration of the solution is 0.2-0.4 mol / L. The solvent can be deionized water. Solubility here refers to the ability of the silver salt to dissolve in the corresponding solvent.

[0073] Step 103: The laser is used to irradiate the surface of the second film layer at the decomposition temperature of the target material, so that the first film layer is thermally decomposed and the surface of the glass substrate fuses with the second film layer in a molten state to obtain the composite film layer.

[0074] Specifically, the surface of the glass substrate can be a plane on the glass substrate that contacts the first film layer. Alternatively, it can be a plane on the glass substrate that contacts the first film layer that extends within 15 μm along the thickness direction of the glass substrate.

[0075] Since the decomposition temperature of the target material is equal to or higher than the melting temperature of the glass substrate, a laser point emitted from a laser source can be briefly suspended on the surface of the second film layer. The heat generated by the laser energy corresponding to the laser point corresponds to the decomposition temperature of the target material, thus causing the first film layer to pyrolyze, and the surface of the glass substrate in direct contact with the first film layer to become molten. Here, the residence time of the laser on the surface of the second film layer corresponds to the average power of the laser energy.

[0076] Specifically, the height of the laser source above the second film layer can be 10-15 cm. A laser source with an average power of 400-800 nanojoules can then be used to irradiate the surface of the second film layer, causing the laser beam to move across the surface. Please refer to [reference needed]. Figure 3 Specifically, the center-to-center distance D between two adjacent laser points is greater than the laser point diameter d (please refer to...). Figure 4 Under the condition that each laser point stays on the surface of the second film for 5-8 seconds, laser direct writing is performed on the second film. Because the energy at the center of the laser point attenuates towards the edge of the laser point, an array of papillae is formed after laser lithography, with protrusions around the laser and depression at the center. That is, papillae are formed on the surface of the second film, resulting in a composite film containing papillae. The depth-to-diameter ratio of these papillae is (0.8-1.5):1.

[0077] The center-to-center distance between two adjacent laser points is the distance between the centers of two adjacent laser points formed on the surface of the second film by the laser emitted by the laser source.

[0078] The aforementioned thermal decomposition of the first film layer is actually a cracking reaction of the first film layer at the thermal decomposition temperature, generating gases such as carbon dioxide and nitrogen oxides that escape, so that the second film layer can fuse with the glass substrate.

[0079] In the aforementioned laser direct writing process, the SiO2 in the second film layer and the SiO2 in the glass substrate first undergo condensation reactions, and then the first film layer thermally decomposes. The surface of the glass substrate and / or the second film layer turn into a molten state and fuse together. Thus, the second film layer after being irradiated by the laser fuses with the glass substrate to form a composite film layer with high adhesion to the substrate.

[0080] In some embodiments, the difference between the center distance D of two adjacent laser points and the diameter d of the laser point is 3-10 μm, i.e., 3≤Dd≤10 μm; in order to balance the morphology and number of papillae on the surface of the composite film and ensure that the first film can be completely decomposed.

[0081] In some embodiments, d can be selected from 3-8 μm. D can be selected from 6-17 μm.

[0082] Furthermore, a laser point cloud can be directly formed on the surface of the second film layer by splitting the laser beam from the laser source, and laser direct writing can be performed to form a papillary array corresponding to the laser point cloud, thus obtaining the target film layer. The surface of the target film layer then includes multiple laser point clouds.

[0083] Based on the same inventive concept, embodiments of this application provide an optical panel, including:

[0084] A glass substrate with a light transmittance greater than 30% and a composite film layer prepared by the aforementioned method.

[0085] The following detailed description is provided through examples and comparative examples:

[0086] Example 1

[0087] S1. Slowly add 15g of fluorinated polyarylene ether nitrile and 700mL of N-methylpyrrolidone solvent to the dissolving device in sequence. Heat the mixing device equipped with a reflux condenser and a mechanical stirrer to 140°C and stir at 200 rpm for 30 minutes.

[0088] S2. After the fluorinated polyarylene ether nitrile is completely dissolved in the solvent, slowly coat the mixed solution onto a clean viewing window, allowing it to flow naturally and dry at room temperature.

[0089] S3. Place the window glass obtained in S2 into an oven and start heating. The heating program is: 100℃, 150℃, and 180℃ for 40 minutes each, and then bake at 220℃ for 90 minutes to completely remove the N-methylpyrrolidone solvent from the film, thus obtaining the first film. The average thickness of the first film is 0.05 mm.

[0090] Preparation of S4 and SiO2 sol:

[0091] Preparation of SiO2 sol under alkaline catalytic conditions: Anhydrous ethanol, concentrated ammonia, deionized water, and TEOS were reacted at a molar ratio of 37:0.8:2:1 at 30℃ for 2-4 hours. The mixture was then removed and aged in a 30℃ constant temperature bath for 3-7 days. Finally, it was refluxed at 80℃ for 6-24 hours to remove ammonia, thus obtaining SiO2 sol under alkaline catalytic conditions.

[0092] Preparation of SiO2 sol under acid catalysis: Anhydrous ethanol, hydrochloric acid, deionized water and TEOS were mixed and reacted at a molar ratio of 20:0.01:4:1 at 30℃ for 6 hours and aged for 3-7 days to obtain SiO2 sol under acid catalysis.

[0093] Alkali-catalyzed SiO2 sol and acid-catalyzed SiO2 sol were mixed at a volume ratio of 4:1 and stirred for 2 hours to obtain an acid / alkali two-step catalytic SiO2 sol.

[0094] Preparation of S5 and TiO2 sol: Anhydrous ethanol, deionized water, concentrated hydrochloric acid and tetrabutyl titanate were added sequentially to a flat-bottomed flask in a molar ratio of 49.75:3.55:0.22:1. After reacting at 30°C for 2 hours, the flask was removed and placed in a sealed glass container and aged in a 30°C constant temperature bath for 3 days.

[0095] Preparation of S6 and SiO2 / TiO2 composite sol: The two sols were mixed at a volume ratio of 10:1, stirred for 2 hours, and then aged in a constant temperature bath at 30℃ for 7 days.

[0096] S7. Add silver nitrate solution with a concentration of 0.2-0.4 mol / L, stir and mix evenly to obtain the target sol.

[0097] S8. The target sol is uniformly coated onto the surface of the first film obtained in S3 using a roller coater. By controlling key parameters such as roller coating speed, roller coating pressure, and roller surface roughness, a second film layer with a thickness of 100nm and a uniformity of 5%-10% is obtained.

[0098] S9. Place the viewing window in the drying oven to dry. Ensure the oven is clean and tidy during baking, with a dust-free level of 10,000.

[0099] S10. Clean the surface of the window glass obtained above and fix it on the femtosecond laser stage. Modulate the diffraction optics (DOE) to split the femtosecond laser beam into a uniform 16mm*16mm square laser point cloud for direct laser writing (the laser point cloud is on the second thin film surface, the shape of the laser points is circular, the diameter of the laser points is d=5μm, and the spacing is D=9μm). During direct writing, the fluorinated polyarylene ether nitrile vapor is rapidly evaporated by side blowing airflow, which reduces heat concentration and reduces the heat-affected zone, ensuring the processing quality and efficiency of laser drilling, and forming a papillary array with a depth-to-diameter ratio of 1:1.

[0100] S11. Ultrasonic cleaning for 2 minutes, followed by baking in an 85℃ oven for 30 minutes, yields a glass plate containing a composite film layer.

[0101] Example 2

[0102] The difference from Example 1 is that the SiO2 sol in step S4 does not contain alkali-catalyzed SiO2 sol, so the SiO2 sol in step S4 is composed only of SiO2 sol obtained by acid catalysis.

[0103] Example 3

[0104] The difference from Example 1 is that step S7 is omitted. All other steps and parameters are the same as in Example 1.

[0105] Comparative Example 1

[0106] The difference from Example 1 is that steps S5-S7 are not included. Step S8 is as follows: SiO2 sol is uniformly coated onto the surface of the first film obtained in S3 using a roller coater. By controlling key parameters such as roller coating speed, roller coating pressure, and roller surface roughness, a second film layer with a thickness of 100nm and a uniformity of 5%-10% is obtained.

[0107] The other steps and parameters are the same as in the example.

[0108] Comparative Example 2

[0109] A composite film is obtained by directly spraying the target sol onto the surface of a glass substrate using a spraying process.

[0110] The following tests were conducted on the above embodiments and comparative examples:

[0111] (1) The transmittance of the glass plate containing the composite film was tested using a high-precision spectrophotometer from Yuanfang Optoelectronics.

[0112] (2) A cross-cut test was performed on the composite film layer on the surface of the glass plate to obtain the bonding force between the composite film layer and the substrate.

[0113] (3) Test the water droplet angle of the composite film under visible light conditions.

[0114] (4) Place the glass plate in a salt spray chamber with 5% NaCl and test the time it takes for it to show signs of peeling. The signs of peeling refer to a significant color change in a certain area of ​​the composite film layer on the surface of the glass plate.

[0115] The test data is shown in Table 1.

[0116] Table 1

[0117] Example 1 95％ 5B 7° 700h Example 2 92％ 5B 6° 700h Example 3 95％ 5B 35° 700h Comparative Example 1 93％ 5B 50 750h Comparative Example 2 91.5％ 3B 8° 240h

[0118] As shown in Table 1, the composite membrane layer in the embodiments has the advantage of strong adhesion, and the composite membrane layer in the embodiments exhibits superior salt spray resistance. Therefore, the composite membrane layer in the embodiments has high density.

[0119] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for preparing a composite film, characterized in that, include: A target material with a light transmittance less than a first threshold is attached to the surface of a glass substrate to form a first film layer; wherein the decomposition temperature of the target material is greater than or equal to the melting temperature of the glass substrate; A target sol containing SiO2 colloidal particles and TiO2 colloidal particles is coated onto the surface of the first film layer to obtain a second film layer; The laser is used to irradiate the surface of the second film layer at the decomposition temperature of the target material, so that the first film layer is thermally decomposed, and the surface of the glass substrate fuses with the second film layer in a molten state to obtain the composite film layer; The thickness of the first film layer is 0.03-0.07 mm; the first threshold is 40% or lower.

2. The method as described in claim 1, characterized in that, The thickness of the second film is 120-150 nm.

3. The method as described in claim 1 or 2, characterized in that, Before coating the target sol containing SiO2 colloidal particles onto the surface of the first film layer to obtain the second film layer, the process includes: The first SiO2 sol was prepared in a reaction system containing an acidic catalyst; A second SiO2 sol was prepared in a reaction system containing an alkaline catalyst. The first SiO2 sol after aging and the second SiO2 sol after aging are mixed to obtain a SiO2 sol containing the SiO2 colloidal particles.

4. The method as described in claim 3, characterized in that, The volume ratio between the second SiO2 sol and the first SiO2 sol is (3.5-4.0):

1.

5. The method as described in claim 4, characterized in that, The target sol includes soluble silver salts; before coating the target sol containing SiO2 colloidal particles and TiO2 colloidal particles onto the surface of the first film layer to obtain the second film layer, the method further includes: SiO2 sol and TiO2 sol were mixed and aged. A solution containing soluble silver salt is added to the aged sol to obtain the target sol; wherein the concentration of the solution is 0.2-0.4 mol / L.

6. The method according to any one of claims 1-2, 4-5, characterized in that, The process of attaching a target material with a light transmittance less than a first preset value to the surface of a glass substrate to obtain a first film layer includes: The target material is dissolved in an organic solvent to obtain a first organic solution; The first organic solution is coated onto the surface of the glass substrate and dried to allow the organic solvent to evaporate, thus obtaining the first film layer.

7. The method as described in claim 6, characterized in that, The target material is a fluorinated polyether material, and the organic solvent is selected from one or more of the following: fluorinated hydrocarbon solvents, ketone solvents, and aromatic hydrocarbon solvents.

8. The method according to any one of claims 1-2, 4-5, and 7, characterized in that, The method of irradiating the surface of the second film layer with laser energy at the decomposition temperature of the target material to cause the first film layer to decompose thermally, and fusing the surface of the glass substrate with the second film layer in a molten state to obtain the composite film layer, includes: Using a laser source with an average power of 400-800 nanojoules, and with the center-to-center distance between two adjacent laser points greater than the diameter of the laser point, and each laser point remaining on the surface for 5-8 seconds, the second film layer is laser-written to obtain the composite film layer containing papillae; wherein the depth-to-diameter ratio of the papillae is (0.8-1.5):

1.

9. The method as described in claim 8, characterized in that, The difference between the center distance of two adjacent laser points and the diameter of the laser point is 3-10 μm.

10. An optical panel, characterized in that, include: The composite film layer prepared by the method according to any one of claims 1-9.

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