Porous high-transmission ar film
By introducing a porous SiO2 layer into the AR film, the problems of AR film adhesion and reflectivity were solved, achieving a breakthrough in high transmittance and stable optical performance, making it suitable for a variety of optical products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TAICANG SIDIKE NEW MATERIALS SCI & TECH CO LTD
- Filing Date
- 2023-03-27
- Publication Date
- 2026-07-03
AI Technical Summary
Existing AR films suffer from low film adhesion, high reflectivity, poor visual effects, and limited selection of coating materials, which restricts the design and performance of optical thin films.
A porous SiO2 layer is used to form a multi-layer AR film through magnetron sputtering. Combined with spraying etchant and etching processes, a porous structure with controllable porosity is constructed to adjust the refractive index of the film. The film includes a transparent substrate layer, an anti-glare hard coating, an interface transition layer, an AR layer, and an anti-fouling layer.
It achieves low reflectivity, high transmittance and stable optical performance, breaking through the material and coating precision limitations of traditional multilayer AR films, and has good visual effects, low cost and is suitable for large-area preparation.
Smart Images
Figure CN116381827B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical film materials, and in particular to a porous high-transmittance AR film. Background Technology
[0002] With the development of optical design and optical coating, optical thin films have been widely used in the fields of optics and optoelectronics. Anti-reflective coatings (AR films), also known as anti-reflective coatings, are the most widely used and produced type of optical thin film in the field of optics, and remain an important research topic in optical thin film technology. The main function of AR films is to reduce reflectivity and increase light transmittance, achieving strong light visibility. They are widely used in automotive displays, smartphones, high-definition televisions, head-mounted displays (HMDs), VR (Virtual Reality) / AR (Augmented Reality) products, and more. Research on AR films focuses on finding new materials (low / high refractive index), designing new film systems, and improving manufacturing processes to achieve the highest possible yield with the fewest layers and the simplest, most stable processes, thus achieving the most ideal anti-reflective effect. Common AR films include single-layer dielectric AR films, double-layer dielectric AR films, multilayer dielectric AR films, and micro / nano structure AR films.
[0003] With the pursuit of lightweighting, organic thin films have replaced glass as the coating substrate, which has become a new trend. AR films are generally set on the outer layer of organic thin films, but existing AR films have low film adhesion, are prone to delamination, and have excessively high reflectivity, resulting in color difference and poor visual effect. In addition, current optical thin films are usually designed according to the film system (the arrangement and combination of refractive index differences and different thicknesses between film materials) to meet specific technical requirements. Since there are not many types of coating materials available, the refractive index that can be selected is very limited and is a fixed constant, which to some extent limits the design of optical thin films and in some cases cannot obtain the required spectral performance. Unconventional refractive index film layers can better match other refractive index film layers, or achieve optical performance that was previously difficult to achieve, or simplify the original film system design and improve the processability of coating. Therefore, the research on variable refractive index film layers, especially high-precision variable refractive index film layer technology, is of great significance for breaking through the bottleneck of high-performance optical thin film development. Through porous structure, low refractive index film is an effective method to obtain film. The relationship between porosity and effective refractive index can be represented by the relationship (1).
[0004] n eff =P·n γ +(1-P)·n s (1)
[0005] Where P is porosity, and n γ n represents the refractive index of the pores. sn represents the refractive index of the solid portion. eff The effective refractive index. According to equation (1), the refractive index of the thin film can be adjusted by utilizing the porous structure (porosity).
[0006] Therefore, it is theoretically feasible to obtain thin films requiring low refractive index by constructing porous structures, but no publicly available and reliable solutions have been found for its application in AR films. Summary of the Invention
[0007] The technical problem to be solved by the present invention is to provide a porous high-transmittance AR film that addresses the shortcomings of the prior art.
[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a porous high-transparency AR film, comprising, from bottom to top, the following layers stacked sequentially: a transparent substrate layer, an anti-glare hard coating layer, an interface transition layer, an AR layer, and an anti-fouling layer;
[0009] The AR layer comprises a first high refractive index layer, a low refractive index layer, a second high refractive index layer, and a porous SiO2 layer, which are stacked sequentially from bottom to top.
[0010] The AR layer is prepared by the following method: a first high refractive index layer, a low refractive index layer, a second high refractive index layer, and a SiO2 substrate are sequentially formed on the interface transition layer by magnetron sputtering. Then, a porous SiO2 layer with controllable porosity is constructed on the SiO2 substrate by spraying etchant, wet etching, dry etching, or wet etching process, thereby obtaining the AR layer.
[0011] Preferably, the refractive index n1 of the first high refractive index layer and the second high refractive index layer at 550 nm satisfies: 2.1≤n1≤2.6, and the refractive index n2 of the low refractive index layer at 550 nm satisfies: 1.0<n2≤1.5.
[0012] Preferably, the materials of the first high refractive index layer and the second high refractive index layer are one or more combinations of titanium dioxide, niobium pentoxide, tantalum pentoxide and silicon nitride compounds;
[0013] The material of the low refractive index layer is one or more of silicon dioxide, aluminum oxide, silicon monoxide, and magnesium fluoride.
[0014] Preferably, in the method for preparing the AR layer, a porous SiO2 layer with controllable porosity is formed on the SiO2 substrate by spraying an etching solution. The specific process is as follows:
[0015] A mixture of hydrofluoric acid and water is used as the etching solution. The etching solution is sprayed onto the SiO2 substrate using a nozzle. The porosity of the formed porous SiO2 layer is controlled by one or more of the following methods: controlling the concentration of the etching solution, the size of the sprayed etching solution droplets, the spraying flow rate of the etching solution, and the dispersion of the etching solution on the SiO2 substrate.
[0016] Preferably, in the method for preparing the AR layer, a porous SiO2 layer with controllable porosity is formed on the SiO2 substrate by spraying an etching solution. The specific process is as follows:
[0017] Hydrofluoric acid aqueous solution with a hydrofluoric acid-to-water ratio of 1:100-1:10 was used as the etching solution. The etching solution was sprayed onto the SiO2 substrate using an array nozzle. An electric field was applied between the array nozzle and the SiO2 substrate, with the voltage of the electric field adjusted to 1000-3000V. The spraying flow rate of the etching solution was controlled at 0.1-50μL / min, the droplet size of the sprayed etching solution was controlled at 200nm-5μm, and the linear velocity of the etching solution sprayed onto the SiO2 substrate was controlled at 1-100mm / s. Finally, a porous SiO2 layer was constructed.
[0018] Preferably, the anti-glare hard coating is formed by applying an anti-glare hardening liquid onto the transparent substrate layer, followed by drying and ultraviolet light curing. The anti-glare hardening liquid comprises the following components by weight percentage:
[0019] The composition includes 10-20% polyurethane acrylic resin, 20-40% multifunctional monomers, 4-8% photoinitiator, 10-30% organic solvent, 10-30% oxide particles, and 0.5-2% dispersant.
[0020] The multifunctional monomer is one or more of di-trimethylolpropane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, or dipentaerythritol hexaacrylate;
[0021] The photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone (184), 2-hydroxy-methylphenylpropane-1-one, benzoin dimethyl ether, and 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide;
[0022] The organic solvent is one or more selected from methanol, ethanol, propanol, acetone, butanone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and ethyl propionate.
[0023] The dispersant is one or more of the following: dispersant DISPERBYK-130, dispersant DISPERBYK-140, dispersant DISPERBYK-142, dispersant DISPERBYK-163, and dispersant DISPERBYK-171.
[0024] Preferably, the oxide particles are one or more selected from SiO2, Al2O3, TiO2, and ZrO2;
[0025] The oxide particles are protruded to one side of the interface transition layer by means of glow discharge treatment, plasma treatment, ion etching or alkaline treatment, and the protrusion height is 0.1-1% of the average particle size of the oxide particles.
[0026] Preferably, the interface transition layer is made of an oxide or metal in an oxygen-deficient state and is formed on the anti-glare hard coating by magnetron sputtering; wherein the oxide in the oxygen-deficient state is one or more of the oxides in the corresponding oxygen-deficient state formed by Si, Al, Ti, Zr, Zn and Ta.
[0027] Preferably, the preparation process of the interface transition layer is as follows: first, the anti-glare hard coating is subjected to glow discharge treatment, and the treatment intensity of the glow discharge treatment is 1800-2300 W·min / m. 2 Then, a Si interface transition layer with a thickness of 1-5 nm is formed on the anti-glare hard coating after glow discharge treatment by sputtering. The sputtering process parameters are: silicon target, coating power of 8000-1500W, Ar flow rate of 40-120sccm, and linear velocity of 1-10.0m / min.
[0028] Preferably, the antifouling layer is prepared by first performing a glow discharge treatment on the surface of the AR layer, wherein the intensity of the glow discharge treatment is 150-750 W·min / m. 2 Next, an antifouling layer containing perfluoropolyether groups of alkoxysilane compounds with a thickness of 5-10 nm is formed on the AR layer by vapor deposition. The vapor deposition process parameters are: vapor deposition temperature 140-360℃, linear velocity 0.2-5.0m / min, and vapor deposition liquid flow rate 0.1-5mL / min.
[0029] The beneficial effects of this invention are:
[0030] This invention provides an AR film with a multilayer film combined with a porous surface structure. Unlike traditional multilayer AR films, this invention can control the refractive index by controlling the porosity of the porous SiO2 layer, so that the multilayer AR film is no longer limited by the stringent requirements of material refractive index and coating precision. Compared with traditional multilayer AR films, it also has the characteristics of good visual effect, low reflectivity and high transmittance, and has stable optical performance under a wide incident angle.
[0031] In the AR layer of this invention, a spraying process is used to spray an etchant onto a SiO2 substrate to form a porous SiO2 layer. By controlling parameters such as the concentration of the etchant, the size of the sprayed etchant droplets, the spraying flow rate of the etchant, and the linear velocity of the etchant sprayed on the SiO2 substrate, high-precision control of porosity can be achieved. This allows for the accurate acquisition of a porous SiO2 layer with the required refractive index. This process can be used for large-area preparation, has good repeatability, and is low in cost, laying the foundation for high-transparency AR film surface processing technology and practical applications. Attached Figure Description
[0032] Figure 1 This is a schematic diagram of the porous high-transmittance AR membrane of the present invention;
[0033] Figure 2 This is a schematic diagram illustrating the control of porosity of porous SiO2 by the spraying process in this invention.
[0034] Figure 3 This invention relates the porosity and refractive index of the porous SiO2 structure at a wavelength of 550 nm.
[0035] Figure 4 The transmittance and reflectance spectra of the porous high-transmittance AR film prepared in Example 1 of the present invention;
[0036] Figure 5 The transmittance and reflectance spectra of the porous high-transmittance AR film prepared in Example 21 of the present invention are shown.
[0037] Explanation of reference numerals in the attached figures:
[0038] 1—Transparent substrate layer; 2—Anti-glare hard coating; 3—Interface transition layer; 4—AR layer; 4a—First high refractive index layer; 4b—Low refractive index layer; 4c—Second high refractive index layer; 4d—Porous SiO2 layer; 5—Anti-fouling layer. Detailed Implementation
[0039] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.
[0040] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.
[0041] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.
[0042] Reference Figure 1 The present invention provides a porous high-transparency AR film, comprising, in order from bottom to top (or from inside to outside): a transparent substrate layer 1, an anti-glare hard coating layer 2, an interface transition layer 3, an AR layer 4, and an anti-fouling layer 5.
[0043] In this invention, the transparent substrate layer 1 is composed of a transparent material capable of transmitting light in the visible light region, using a material with a light transmittance of 80% or more in the wavelength region without impairing the effects of the invention. The transparent substrate 1 can be a sheet or roll of one of the following materials: polyethylene naphthalate (PEN), polyethylene terephthalate (PET), cellulose triacetate (TAC), cyclic olefin copolymer (COP), cyclic olefin polymer (COC), polycarbonate (PC), or other polymeric resin materials. The transparent substrate 1 can also be an inorganic substrate, such as a glass film. The transparent substrate 1 can also be a film material endowed with optical and / or physical functions, such as a polarizing plate, phase difference compensation film, heat ray blocking film, transparent conductive film, brightness-enhancing film, or barrier-enhancing film. The thickness of the transparent substrate 1 is not particularly limited, but is typically 25–200 μm, preferably 40–80 μm. The surface of the transparent substrate 1 can be pre-treated with etching processes such as sputtering, corona discharge, ultraviolet irradiation, electron beam irradiation, chemical conversion, and oxidation, as well as primer treatment, solvent cleaning, and ultrasonic cleaning. This process can remove dust and clean the surface of the transparent substrate 1, and improve the adhesion of the hard coating 2 on the transparent substrate 1.
[0044] In this invention, the anti-glare hard coating 2 is formed by coating an anti-glare hardening liquid onto a transparent substrate layer 1, followed by drying and ultraviolet light curing. The anti-glare hardening liquid comprises the following components by mass percentage:
[0045] The composition includes 10-20% polyurethane acrylic resin, 20-40% multifunctional monomers, 4-8% photoinitiator, 10-30% organic solvent, 10-30% oxide particles, and 0.5-2% dispersant.
[0046] The multifunctional monomer is one or more of di-trimethylolpropane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, or dipentaerythritol hexaacrylate.
[0047] The photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone (184), 2-hydroxy-methylphenylpropane-1-one (1173), benzoin dimethyl ether (651), and 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide (TPO).
[0048] The organic solvent is one or more of the conventional alcohols, ketones, or esters. Alcohols include methanol, ethanol, and propanol; ketones include acetone, butanone, and methyl isobutyl ketone; and esters include ethyl acetate, butyl acetate, and ethyl propionate.
[0049] The dispersant is one or more of BYK Chemical's DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-163, and DISPERBYK-171.
[0050] The thickness of the anti-glare hard coating 2 is preferably 2μm-10μm, and its preparation process is as follows: an anti-glare hardening liquid is coated on the transparent substrate layer 1, dried, and cured under ultraviolet light to obtain the anti-glare hard coating 2. The UV energy for ultraviolet curing is 500mJ / cm. 2 ~1000mJ / cm 2 .
[0051] The oxide particles are one or more of SiO2, Al2O3, TiO2, and ZrO2, with highly transparent SiO2 being preferred.
[0052] Among them, oxide particles are protruded to one side of the interface transition layer 3 by methods such as glow discharge treatment, plasma treatment, ion etching or alkaline treatment, and the protrusion height is 0.1-1% of the average particle size of oxide particles.
[0053] In this invention, the interface transition layer 3 is made of oxide or metal in an oxygen-deficient state and is formed on the anti-glare hard coating 2 by magnetron sputtering.
[0054] Among them, oxygen-deficient metal oxides refer to oxides in which the number of oxygen atoms is less than the stoichiometric composition. Oxide with oxygen vacancies is one or more of the oxides SiOx, AlOx, TiOx, ZrOx, ZnOx, and TaOx that form the corresponding oxygen vacancies in Si, Al, Ti, Zr, Zn, and Ta.
[0055] In a preferred embodiment, the thickness of the interface transition layer 3 is less than 50% of the average particle size of the metal oxide particles exposed on the surface of the hard coating, specifically 1 nm to 10 nm.
[0056] In a preferred embodiment, the preparation process of the interface transition layer 3 is as follows: first, the anti-glare hard coating 2 is subjected to glow discharge treatment, and the treatment intensity of the glow discharge treatment is 1800-2300 W·min / m. 2Then, a Si interface transition layer 3 with a thickness of 1-5 nm is formed on the anti-glare hard coating 2 after glow discharge treatment by sputtering. The sputtering process parameters are: silicon target, coating power of 8000-1500W, Ar flow rate of 40-120sccm, and linear velocity of 1-10.0m / min.
[0057] In this invention, the AR layer 4 includes a first high refractive index layer 4a, a low refractive index layer 4b, a second high refractive index layer 4c, and a porous SiO2 layer 4d stacked sequentially from bottom to top. The AR layer 4 is prepared by the following method: the first high refractive index layer 4a, the low refractive index layer 4b, the second high refractive index layer 4c, and the SiO2 substrate are sequentially formed on the interface transition layer 3 by magnetron sputtering. Then, a porous SiO2 layer 4d with controllable porosity is constructed on the SiO2 substrate by spraying an etchant, wet etching, dry etching, or wet etching process, thereby obtaining the AR layer 4.
[0058] Among them, the refractive index is adjusted by controlling the porosity of the outermost porous SiO2 layer 4d, so that the AR film is no longer limited by the stringent requirements of material refractive index and coating precision.
[0059] Among them, the refractive index n1 of the first high refractive index layer 4a and the second high refractive index layer 4c at 550nm satisfies: 2.1≤n1≤2.6, and the refractive index n2 of the low refractive index layer 4b at 550nm satisfies: 1.0<n2≤1.5.
[0060] The materials of the first high refractive index layer 4a and the second high refractive index layer 4c are one or more combinations of titanium dioxide (TiO2), niobium pentoxide (Nb2O5), tantalum pentoxide (Ta2O5), and silicon nitride (SiNx);
[0061] The material of the low refractive index layer 4b is one or a combination of silicon dioxide (SiO2), aluminum oxide (Al2O3), silicon monoxide (SiO), and magnesium fluoride (MgF2).
[0062] In a preferred embodiment, the preparation method of AR layer 4 involves constructing a porous SiO2 layer 4d with controllable porosity on a SiO2 substrate by spraying an etching solution. The specific process is as follows: a mixture of hydrofluoric acid and water is used as the etching solution, and the etching solution is sprayed onto the SiO2 substrate using a nozzle. The porosity of the constructed porous SiO2 layer 4d is controlled by one or more of the following means: controlling the concentration of the etching solution, the size of the sprayed etching solution droplets, the spraying flow rate of the etching solution, and the dispersion of the etching solution on the SiO2 substrate.
[0063] In a further preferred embodiment, the AR layer 4 is prepared by spraying an etching solution to form a porous SiO2 layer 4d with controllable porosity on the SiO2 substrate. The specific process is as follows:
[0064] Hydrofluoric acid aqueous solution with a hydrofluoric acid to water ratio of 1:100-1:10 was used as the etching solution. The etching solution was sprayed onto the SiO2 substrate using an array nozzle. An electric field was applied between the array nozzle and the SiO2 substrate, with the voltage of the electric field adjusted to 1000-3000V. The spraying flow rate of the etching solution was controlled at 0.1-50μL / min, the droplet size of the sprayed etching solution was controlled at 200nm-5μm, and the linear velocity of the etching solution sprayed on the SiO2 substrate was controlled at 1-100mm / s. Finally, a porous SiO2 layer with a diameter of 4d was constructed.
[0065] The process of spraying etchant is easier for roll-to-roll production, is a mature technology, and has the advantages of controllable droplet size, high precision, and maximized material savings. (Refer to...) Figure 2 This diagram illustrates how porosity is controlled in a spraying process by adjusting the dispersion and size of the etchant droplets. In a preferred embodiment, an ultra-high precision electrohydraulic iEHD spraying system is used, which features ultra-high spraying accuracy and surface uniformity, enabling precise control of porosity.
[0066] By controlling the porosity, porous SiO2 layers with different refractive indices (4d) can be obtained, thus providing greater flexibility to meet the needs of different products. (Refer to...) Figure 3 The figure shows the relationship between porosity and refractive index of a porous SiO2 4d layer at a wavelength of 550 nm. It can be seen that within a certain range, the larger the porosity, the smaller the refractive index of the porous SiO2 4d layer. Larger porosity results in a higher air density and a lower SiO2 density, thus altering the refractive index of the SiO2 film. Excessive porosity can lead to reduced strength, collapse, and damage to the porous SiO2 4d layer. Therefore, it is necessary to control the porosity within a certain range. Within this range, an appropriate porosity can be selected based on the required refractive index of the porous SiO2 4d layer.
[0067] In this invention, the antifouling layer 5 is located on the outermost surface of the AR layer 4. The antifouling layer 5 prevents contamination of the AR layer 4 and imparts water repellency, oil repellency, and sweat resistance; furthermore, when applied to touch panels, the antifouling layer 5 inhibits wear and tear on the AR layer 4 through its abrasion resistance and scratch resistance. In a preferred embodiment, the fluorine compound contained in the antifouling layer 5 is, for example, a fluorine-based organic compound. For example, by using an alkoxysilane compound with a perfluoropolyether group as the fluorine-containing organic compound, it is possible to exhibit water repellency with a water contact angle of 110° or higher, thereby improving antifouling properties. The thickness of the antifouling layer 5 is 2 nm-15 nm, and the antifouling layer 5 can be prepared by wet coating, organic vapor deposition, chemical vapor deposition, etc.
[0068] In a preferred embodiment, the fabrication process of the antifouling layer 5 is as follows: first, a glow discharge treatment is performed on the surface of the AR layer 4, with the intensity of the glow discharge treatment being 150-750 W·min / m. 2 Next, an antifouling layer 5 containing perfluoropolyether-based alkoxysilane compounds with a thickness of 5-10 nm is formed on AR layer 4 by vapor deposition. The vapor deposition process parameters are: vapor deposition temperature 140-360℃, linear velocity 0.2-5.0 m / min, and vapor deposition liquid flow rate 0.1-5 mL / min.
[0069] The above is the general concept of the present invention. Detailed embodiments are provided below to further illustrate the present invention.
[0070] Example 1
[0071] A porous high-transparency AR film includes, from bottom to top, the following layers stacked sequentially: a transparent substrate layer 1, an anti-glare hard coating layer 2, an interface transition layer 3, an AR layer 4, and an anti-fouling layer 5;
[0072] 1. The transparent substrate is a cellulose triacetate (TAC) roll with a thickness of 60-80μm.
[0073] 2. The preparation process of the anti-glare hard coating 2 is as follows: an anti-glare hardening liquid is coated on the transparent substrate layer 1, dried, and cured with ultraviolet light to obtain an anti-glare hard coating 2 with a thickness of 5-10 μm. The UV energy for ultraviolet curing is 500 mJ / cm². 2 .
[0074] The anti-glare and hardening liquid comprises the following components by mass percentage: 15% polyurethane acrylic resin, 30% multifunctional monomer, 5% photoinitiator, 25% oxide particles, 1% dispersant, and the remainder being organic solvent. The multifunctional monomer is pentaerythritol triacrylate, the photoinitiator is 1-hydroxycyclohexylphenyl ketone (184), the organic solvent is ethyl acetate, the oxide particles are silica particles, and the dispersant is DISPERBYK-171.
[0075] 3. The preparation process of the interface transition layer 3 is as follows: First, the anti-glare hard coating 2 is subjected to glow discharge treatment, and the treatment intensity of the glow discharge treatment is 2000 W·min / m. 2 Then, a Si interface transition layer 3 with a thickness of 1-5 nm is formed on the anti-glare hard coating 2 after glow discharge treatment by sputtering. The sputtering process parameters are: silicon target, coating power of 1000W, Ar flow rate of 80sccm, and linear velocity of 3.0m / min.
[0076] 4. The fabrication process of AR layer 4 is as follows:
[0077] (1) A first high refractive index layer 4a (specifically, an Nb2O5 layer), a low refractive index layer 4b (specifically, a SiO2 layer), a second high refractive index layer 4c (specifically, an Nb2O5 layer), and a SiO2 base layer are sequentially deposited on the interface transition layer 3 by magnetron sputtering.
[0078] The sputtering process parameters for the first high refractive index layer 4a are: niobium target, coating power 2000W, Ar / O2 flow rate 40 / 10sccm, linear velocity 0.2m / min, and thickness 10-15nm.
[0079] The sputtering process parameters for the low refractive index layer 4b are as follows: silicon target, coating power 5000W, Ar / O2 flow rate 40 / 80sccm, linear velocity 0.2m / min, and thickness 25-30nm.
[0080] The sputtering process parameters for the second high refractive index layer 4c are: niobium target, coating power 8000W, Ar / O2 flow rate 80 / 20sccm, linear velocity 0.2m / min, and thickness 110-120nm.
[0081] The sputtering process parameters for the SiO2 substrate are: silicon target, coating power 6000W, Ar / O2 flow rate 80 / 120sccm, linear velocity 0.2m / min, and thickness 80-90nm.
[0082] (3) A porous SiO2 layer 4d formed on a SiO2 substrate by spraying:
[0083] The etching solution was dispersed and sprayed onto AR layer 4 using an ultra-high precision electrohydrodynamic (iEHD) spraying system. An array nozzle was used, and an electric field was applied between the array nozzle and the SiO2 substrate. The voltage controller was adjusted to output an AC pulse voltage with a frequency of 50Hz and a high voltage of 2000V. The spraying flow rate of the etching solution was controlled at 30μL / min, the spraying linear velocity at 10mm / s, the droplet size of the etching solution at 500nm, and the volume ratio of HF to water in the etching solution at 3:50.
[0084] 5. The antifouling layer 5 is formed by vapor deposition: First, glow discharge treatment is performed on the surface of AR layer 4, with an intensity of 320 W·min / m2; then, an antifouling layer 5 with a thickness of 5-10 nm of alkoxysilane compound with perfluoropolyether group is formed on AR layer 4 by vapor deposition. The vapor deposition process parameters are: vapor deposition temperature 280℃, linear velocity 1.0 m / min, and vapor deposition liquid flow rate 0.5 ml / min.
[0085] Example 2
[0086] The preparation process of the porous high-transmittance AR film provided in this embodiment is basically the same as that in Example 1. The main difference lies in the process of constructing the porous SiO2 layer 4d in the AR layer 4. Specifically, the process in this embodiment is as follows:
[0087] The etching solution was dispersed and sprayed onto AR layer 4 using an ultra-high precision electrohydrodynamic (iEHD) spraying system. An array nozzle was used, and an electric field was applied between the array nozzle and the SiO2 substrate. The voltage controller was adjusted to output an AC pulse voltage with a frequency of 50Hz and a high voltage of 2000V. The spraying flow rate of the etching solution was controlled at 10μL / min, the spraying linear velocity at 10mm / s, the droplet size of the etching solution at 200nm, and the volume ratio of HF to water in the etching solution at 3:50.
[0088] The main difference between Example 1 and Example 2 lies in the spraying flow rate and droplet size of the etching solution in the process of constructing the 4d porous SiO2 layer. The porosity of the 4d porous SiO2 layer can be adjusted by controlling these two process parameters. In Example 1, the droplet size is controlled at 500 nm, the spraying flow rate is 30 μL / min, and the porosity is approximately 20%. Figure 4 The transmittance and reflectance spectra of the porous high-transmittance AR film prepared in Example 1 show that its total light transmittance reaches 96.3% and the average reflectance is 0.29% in the 380-780 nm wavelength range. In Example 2, the droplet size was controlled at 200 nm and the spraying flow rate was 10 μL / min, resulting in a porosity of approximately 5%. Figure 5 The transmittance and reflectance spectra of the porous high-transmittance AR film prepared in Example 2 show that in the 380-780nm wavelength range, its total light transmittance reaches 96.1%, and the average reflectance is 0.30%.
[0089] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.
Claims
1. A porous, high-transmittance AR film, characterized in that, It includes, from bottom to top, the following layers stacked together: a transparent substrate layer, an anti-glare hard coating layer, an interface transition layer, an AR layer, and an anti-fouling layer; The AR layer comprises a first high refractive index layer, a low refractive index layer, a second high refractive index layer, and a porous SiO2 layer, which are stacked sequentially from bottom to top. The AR layer is prepared by the following method: a first high refractive index layer, a low refractive index layer, a second high refractive index layer and a SiO2 substrate are sequentially formed on the interface transition layer by magnetron sputtering. Then, a porous SiO2 layer with controllable porosity is constructed on the SiO2 substrate by spraying an etching solution, thereby obtaining the AR layer. In the method for preparing the AR layer, the specific process of constructing a porous SiO2 layer with controllable porosity on the SiO2 substrate by spraying an etching solution is as follows: Hydrofluoric acid aqueous solution with a hydrofluoric acid-to-water ratio of 1:100-1:10 was used as the etching solution. The etching solution was sprayed onto the SiO2 substrate using an array nozzle. An electric field was applied between the array nozzle and the SiO2 substrate, with the voltage of the electric field adjusted to 1000-3000V. The spraying flow rate of the etching solution was controlled at 0.1-50μL / min, the droplet size of the sprayed etching solution was controlled at 200nm-5μm, and the linear velocity of the etching solution sprayed onto the SiO2 substrate was controlled at 1-100mm / s. Finally, a porous SiO2 layer was constructed.
2. The porous high-transmittance AR film according to claim 1, characterized in that, The refractive indices n1 of the first and second high refractive index layers at 550 nm satisfy: 2.1 ≤ n1 ≤ 2.6, and the refractive index n2 of the low refractive index layer at 550 nm satisfies: 1.0 < n2 ≤ 1.
5.
3. The porous high-transmittance AR film according to claim 2, characterized in that, The materials of the first high refractive index layer and the second high refractive index layer are one or more combinations of titanium dioxide, niobium pentoxide, tantalum pentoxide and silicon nitride compounds; The material of the low refractive index layer is one or more of silicon dioxide, aluminum oxide, silicon monoxide, and magnesium fluoride.
4. The porous high-transmittance AR film according to claim 1, characterized in that, The anti-glare hard coating is formed by applying an anti-glare hardening liquid onto the transparent substrate layer, followed by drying and ultraviolet light curing. The anti-glare hardening liquid comprises the following components by mass percentage: The composition includes 10-20% polyurethane acrylic resin, 20-40% multifunctional monomers, 4-8% photoinitiator, 10-30% organic solvent, 10-30% oxide particles, and 0.5-2% dispersant. The multifunctional monomer is one or more of di-trimethylolpropane tetraacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, or dipentaerythritol hexaacrylate. The photoinitiator is one or more of 1-hydroxycyclohexylphenyl ketone (184), 2-hydroxy-methylphenylpropane-1-one, benzoin dimethyl ether, and 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide; The organic solvent is one or more selected from methanol, ethanol, propanol, acetone, butanone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and ethyl propionate. The dispersant is one or more of the following: dispersant DISPERBYK-130, dispersant DISPERBYK-140, dispersant DISPERBYK-142, dispersant DISPERBYK-163, and dispersant DISPERBYK-171.
5. The porous high-transmittance AR film according to claim 4, characterized in that, The oxide particles are one or more of SiO2, Al2O3, TiO2, and ZrO2; The oxide particles are protruded to one side of the interface transition layer by means of glow discharge treatment, plasma treatment, ion etching or alkaline treatment, and the protrusion height is 0.1-1% of the average particle size of the oxide particles.
6. The porous high-transmittance AR film according to claim 1, characterized in that, The interface transition layer is formed on the anti-glare hard coating by using an oxide or metal in an oxygen-deficient state as the material and a magnetron sputtering process; wherein, the oxide in the oxygen-deficient state is one or more of the oxides in the corresponding oxygen-deficient state formed by Si, Al, Ti, Zr, Zn and Ta.
7. The porous high-transmittance AR film according to claim 6, characterized in that, The preparation process of the interface transition layer is: first, the anti-glare hard coating is subjected to glow discharge treatment, the treatment intensity of the glow discharge treatment is 1800-2300 W·min / m 2 ; then, the Si interface transition layer with a thickness of 1-5 nm is formed on the anti-glare hard coating after the glow discharge treatment by sputtering, the sputtering process parameters are: silicon target, the coating power is 8000-1500 W, the flow rate of Ar is 40-120 sccm, and the linear speed is 1-10.0 m / min.
8. The porous high-transmittance AR film according to claim 1, characterized in that, The antifouling layer is prepared by first performing a glow discharge treatment on the surface of the AR layer, with the intensity of the glow discharge treatment being 150-750 W·min / m. 2 Next, an antifouling layer containing perfluoropolyether groups of alkoxysilane compounds with a thickness of 5-10 nm is formed on the AR layer by vapor deposition. The vapor deposition process parameters are: vapor deposition temperature 140-360℃, linear velocity 0.2-5.0m / min, and vapor deposition liquid flow rate 0.1-5mL / min.