Optical film, method for manufacturing the same, display piece, and electronic device

Abstract

The application provides an optical film and a preparation method thereof, a display piece and an electronic device; wherein the optical film comprises a substrate, a low-refraction anti-reflection layer and a wear-resistant anti-reflection layer; the low-refraction anti-reflection layer and the wear-resistant anti-reflection layer are respectively located on two sides of the substrate; from the direction close to the substrate to the direction away from the substrate, the low-refraction anti-reflection layer comprises a second-refraction sub-anti-reflection layer and a first-refraction sub-anti-reflection layer which are arranged in a stack; the refractive index of the first-refraction sub-anti-reflection layer is a, and the refractive index of the second-refraction sub-anti-reflection layer is b; from the direction close to the substrate to the direction away from the substrate, the wear-resistant anti-reflection layer comprises a third-refraction sub-anti-reflection layer and a fourth-refraction sub-anti-reflection layer which are arranged in a stack, and the total number of layers of the third-refraction sub-anti-reflection layer and the fourth-refraction sub-anti-reflection layer is greater than or equal to 4; the refractive index of the third-refraction sub-anti-reflection layer is c, the refractive index of the fourth-refraction sub-anti-reflection layer is d, and a < b < c < d.

Description

Technical Field

[0001] This invention belongs to the field of optical thin film technology, and relates to an optical film and its preparation method, a display device, and an electronic device. Background Technology

[0002] In optical products such as lenses, displays, and displays, antireflective coatings are used to reduce light reflection and increase transmittance. An ideal antireflective coating requires low reflectivity, high abrasion resistance, high hardness, and environmental stability. Existing antireflective coatings suffer from high reflectivity.

[0003] To reduce the reflectivity of antireflective coatings, low-refractive-index materials such as magnesium fluoride (MgF2) and porous silica (SiO2) can be used. However, the refractive index of magnesium fluoride is about 1.38, which is difficult to further reduce to the ideal value, making it difficult to break through the theoretical limit of reflectivity. Although porous silica can reduce the refractive index, its high porosity results in low film hardness, making it prone to scratches and pore collapse during subsequent processing or use, and it also has poor environmental stability.

[0004] Therefore, there is a need in the field for an optical film that simultaneously possesses high transmittance, high hardness, and high abrasion resistance. Summary of the Invention

[0005] This invention provides an optical film that, through a dual-sided synergistic film layer design and a multi-layer alternating structure, improves the hardness and wear resistance of the optical film while ensuring its transmittance.

[0006] The present invention also provides a method for preparing an optical film, which can prepare the above-mentioned optical film and has a simple process.

[0007] The present invention also provides a display device, which, because it includes the above-mentioned optical film, has ultra-low reflection on the product side of its display screen and high wear resistance on the user side, thus balancing visual effect and durability.

[0008] The present invention also provides an electronic device, which, because it includes the above-mentioned optical film or display element, has a display screen with good visual effect and durability.

[0009] In a first aspect, the present invention provides an optical film comprising a substrate, a low-refractive-index antireflective layer, and a wear-resistant antireflective layer; wherein the low-refractive-index antireflective layer and the wear-resistant antireflective layer are respectively located on both sides of the substrate; in the direction from near the substrate to away from the substrate, the low-refractive-index antireflective layer comprises a second refracting antireflective layer and a first refracting antireflective layer stacked together; the refractive index of the first refracting antireflective layer is a, and the refractive index of the second refracting antireflective layer is b; in the direction from near the substrate to away from the substrate, the wear-resistant antireflective layer comprises a third refracting antireflective layer and a fourth refracting antireflective layer stacked together, the total number of layers of the third refracting antireflective layer and the fourth refracting antireflective layer is greater than or equal to 4; the refractive index of the third refracting antireflective layer is c, and the refractive index of the fourth refracting antireflective layer is d, a <b<c<d。

[0010] Optionally, where 1.1 ≤ a ≤ 1.2;

[0011] And / or, 1.3 ≤ b < 1.4;

[0012] And / or, 1.4 ≤ c < 1.5;

[0013] And / or, 1.8≤d≤2.1.

[0014] Optionally, the material of the first refractive antireflective layer includes silicon dioxide;

[0015] And / or, the material of the second refractive antireflective layer includes silicon dioxide;

[0016] And / or, the material of the third refractive index antireflective layer includes silicon dioxide;

[0017] And / or, the material of the fourth refractive index antireflective layer includes silicon nitride;

[0018] And / or, an underlayer is further included between the second refractive index antireflection layer and the substrate, the underlayer and the second refractive index antireflection layer being stacked; preferably, the material of the underlayer includes silicon dioxide.

[0019] Optionally, the first refractive antireflection layer includes a first nanopore structure, wherein the pore size of the first nanopore structure is less than 50 nm; preferably, the pore size of the first nanopore structure is 10 nm to 30 nm.

[0020] And / or, the porosity of the first antireflective layer is x, where x satisfies: 60% <x≤80%;

[0021] And / or, the second refractive antireflection layer includes a second nanopore structure, wherein the pore size of the second nanopore structure is less than 50 nm; preferably, the pore size of the second nanopore structure is 10 nm-30 nm.

[0022] And / or, the porosity of the second refractive antireflection layer is y, where y satisfies: 40%≤y≤60%.

[0023] Optionally, the first nanoporous structure and / or the second nanoporous structure includes hydrophobic groups, preferably, the hydrophobic groups include trimethylsilyl groups.

[0024] Optionally, the total thickness of the fourth antireflective layer is greater than the total thickness of the third antireflective layer;

[0025] And / or, the total thickness of the first refracting antireflection layer and the second refracting antireflection layer is 200nm-300nm;

[0026] And / or, the thickness of the underlying layer is less than or equal to 100 nm;

[0027] And / or, the total thickness of the wear-resistant and anti-reflective layer is greater than or equal to 600 nm;

[0028] Optionally, the thickness of the first antireflective layer is less than or equal to 150 nm;

[0029] And / or, the thickness of the second refractive antireflection layer is less than or equal to 100 nm.

[0030] Optionally, the optical film satisfies at least one of the following conditions:

[0031] 1) The average transmittance of the optical film is greater than or equal to 99% in the 400nm-680nm range;

[0032] 2) The pencil hardness of the optical film is 7-9H;

[0033] 3) The cross-cut adhesion of the optical film is 4-5B;

[0034] 4) The thrust of the optical film is greater than or equal to 500N;

[0035] 5) The nanohardness of the optical film is greater than or equal to 12 GPa;

[0036] 6) The water droplet angle of the low-refractive antireflection layer of the optical film is greater than or equal to 140°;

[0037] 7) The water droplet angle of the wear-resistant and anti-reflective layer of the optical film is greater than or equal to 110°.

[0038] Secondly, the present invention provides a method for preparing an optical film, comprising the following steps:

[0039] A second refracting antireflection layer and a first refracting antireflection layer are disposed on one side of the substrate to form the low refractive antireflection layer;

[0040] A third refracting antireflective layer and a fourth refracting antireflective layer are stacked on the other side of the substrate to form the wear-resistant antireflective layer, thereby obtaining the optical film.

[0041] Optionally, the provision of the second antireflective layer and the first antireflective layer on one side of the substrate specifically includes the following steps:

[0042] The second refractive index antireflection layer is formed on one side of the substrate by a single magnetron co-sputtering process using a Si target and a Si-Al target; or, the substrate is formed on one side by a single sputtering process using a Si target, and the second refractive index antireflection layer is formed on one side of the substrate by a single magnetron co-sputtering process using a Si target and a Si-Al target.

[0043] The first refractive index antireflection layer is formed on one side of the second refractive index antireflection layer by using a Si target and a Si-Al target through a secondary magnetron co-sputtering process.

[0044] The low-refractive-index antireflective layer is obtained by acid etching.

[0045] And / or, a third refractive index antireflection layer and a fourth refractive index antireflection layer are disposed on the other side of the substrate, specifically including the following steps:

[0046] The third refractive index antireflection layer is formed on the other side of the substrate by a secondary sputtering process using a Si target.

[0047] The fourth refractive index antireflection layer is formed on one side of the third refractive index antireflection layer by three sputtering processes on the other side of the substrate using a Si target.

[0048] The primary sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5 KW-10 KW.

[0049] And / or, the first magnetron co-sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 4 kW-10 kW, and the sputtering power of the Si-Al target is 5 kW-10 kW.

[0050] And / or, the secondary magnetron co-sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 2 kW-6 kW and the sputtering power of the Si-Al target is 5 kW-10 kW.

[0051] And / or, the secondary sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5KW-10KW.

[0052] And / or, the three sputtering processes include: achieving a coating vacuum of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas N2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas N2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5 kW-10 kW.

[0053] Optionally, after forming the first and second antireflective layers on one side of the substrate, the method further includes the following steps:

[0054] The substrate with the first and second antireflective layers is placed in an atmosphere containing hexamethyldisilazane to form hydrophobic groups.

[0055] Thirdly, the present invention provides a display device comprising an optical film prepared by the method of the first aspect or the method of the second aspect.

[0056] Optionally, the low-refractive antireflective layer is disposed on the product side of the substrate; the abrasion-resistant antireflective layer is disposed on the user side of the substrate.

[0057] Fourthly, the present invention provides an electronic device, including an optical film prepared by the method of the first aspect or the method of the second aspect or the display device of the third aspect.

[0058] The optical film provided by this invention features a dual-sided synergistic film layer design. One side faces the light source or internal structure and has a low refractive index with adjustable refractive index. The other side faces the external environment and has wear and scratch resistance. Specifically, the low-refractive-index antireflection layer achieves an ultra-low single-sided reflectivity effect by having the first refractive-index antireflection layer have the lowest refractive index. The refractive indices of the first and second refractive-index antireflection layers form a gradient transition, effectively mitigating interference loss caused by abrupt changes in refractive index. The wear-resistant antireflection layer significantly improves the hardness and wear resistance of the film layer through alternating layers of high and low refractive index materials. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of the optical film in a specific embodiment of the present invention;

[0060] Figure 2 This is a microscopic SEM image of the first refractive index sub-antireflection layer after acid etching in Example 1;

[0061] Figure 3 This is a single-sided reflectance curve of the low-refractive antireflection layer in Example 1;

[0062] Figure 4 This is a microscopic SEM image of the first refractive index sub-antireflection layer before acid etching in Example 1;

[0063] Figure 5 The images are SEM images of the low-refractive antireflection layers after acid etching in Examples 1 and 8; where a is the SEM image of the low-refractive antireflection layer after acid etching in Example 8, and b is the SEM image of the low-refractive antireflection layer after acid etching in Example 1.

[0064] Figure 6 The transmittance curve of the optical film in Example 1;

[0065] Figure 7 The transmittance curve of the optical film in Comparative Example 1 is shown.

[0066] Figure 8 The transmittance curve of the optical film in Comparative Example 2 is shown.

[0067] Figure 9 The transmittance curve of the optical film in Comparative Example 3 is shown.

[0068] Figure 10 The transmittance curve is for the optical film in Comparative Example 4.

[0069] Explanation of reference numerals in the attached figures:

[0070] 1-First antireflective layer for refraction; 2-Second antireflective layer for refraction; 3-Underlayer; 4-Substrate; 5-Third antireflective layer for refraction; 6-Fourth antireflective layer for refraction. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0072] Research has shown that the theoretically achievable average residual reflectivity for low-reflection films depends on the bandwidth, the refractive index of the outermost layer, the number of antireflective layers, the total thickness, and the difference between the high and low refractive indices of the layers excluding the outermost layer. Therefore, for most lenses, optical components, and common optical products, whose optical applications are primarily in the visible light band, and where the film layer needs to be wear-resistant, scratch-resistant, and possess good mechanical properties, the refractive index of the outermost layer and the difference between the high and low refractive indices of the film layer are key factors affecting the average residual reflectivity.

[0073] Based on the above, in the first aspect, the present invention provides an optical film, see [link to relevant documentation]. Figure 1 The system includes a substrate 4, a low-refractive-index anti-reflective layer, and a wear-resistant anti-reflective layer; wherein the low-refractive-index anti-reflective layer and the wear-resistant anti-reflective layer are located on opposite sides of the substrate; from the direction closest to the substrate to the direction furthest from the substrate, the low-refractive-index anti-reflective layer includes a second refractive-index anti-reflective layer 2 and a first refractive-index anti-reflective layer 1 stacked together; the refractive index of the first refractive-index anti-reflective layer is a, and the refractive index of the second refractive-index anti-reflective layer is b; the wear-resistant anti-reflective layer includes a third refractive-index anti-reflective layer 5 and a fourth refractive-index anti-reflective layer 6 stacked together, the total number of layers of the third refractive-index anti-reflective layer and the fourth refractive-index anti-reflective layer is greater than or equal to 4; the refractive index of the third refractive-index anti-reflective layer is c, and the refractive index of the fourth refractive-index anti-reflective layer is d, a <b<c<d。

[0074] In this invention, a low-refractive antireflective layer is provided on one side of the substrate, and a wear-resistant antireflective layer is provided on the other side of the substrate. This enables functional separation between the product side and the user side, avoiding compromises between optical and mechanical properties in a single-sided film layer. At the same time, the refractive index gradient design of each sublayer achieves high transmittance over a wide band and at multiple angles, and the reflectance is reduced to the limit by utilizing the principle of interference cancellation, thereby reducing the average reflectance of the optical film in the range of 400-680 nm. Furthermore, the multi-layered alternating structure of the wear-resistant antireflective layer can enhance the freedom of film system design, making it easier to improve its mechanical strength and environmental stability while ensuring transmittance.

[0075] In some alternative implementations, 1.1 ≤ a ≤ 1.2. The ultra-low refractive index of the first refractory antireflection layer is key to achieving near-zero reflection in the optical film. Exemplarily, a is any value or a range of any combination of 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, 1.2, etc.

[0076] In some alternative implementations, 1.3 ≤ b < 1.4. The second antireflective layer, serving as an intermediate layer for the low-refractive-index antireflective layer, balances the refractive index difference between the bottom layer and the outermost first antireflective layer, preventing abrupt changes in interface reflection. Exemplarily, b is any value from 1.3, 1.31, 1.32, 1.33, 13.4, 1.35, 1.36, 1.37, 1.38, 1.39, or a range of any combination of both.

[0077] In some alternative embodiments, 1.4 ≤ c < 1.5. A third refractive index antireflective layer with the above refractive indices can ensure that the optical film as a whole has a certain refractive index and guarantee the initial abrasion resistance of the abrasion-resistant antireflective layer. For example, c is any value from 1.4, 1.45, 1.5, etc., or a range of any combination of both.

[0078] In some alternative embodiments, 1.8 ≤ d ≤ 2.1. A fourth refractive index antireflective layer with these values ​​ensures that the overall optical film has a certain refractive index and guarantees the high wear resistance of the wear-resistant antireflective layer. For example, d is any value from 1.8, 1.9, 2.0, 2.1, or a range of any combination of both.

[0079] In some implementations, the values ​​of a, b, c, and d can be measured using a JAWoollam ellipsometer.

[0080] In some alternative embodiments, the first refractive index antireflection layer is made of silicon dioxide. This first refractive index antireflection layer can achieve an ultra-low refractive index of 1.1-1.2.

[0081] In some alternative embodiments, the second refractive index antireflective layer is made of silicon dioxide. This material allows for precise control of the refractive index between 1.3 and 1.4.

[0082] In some alternative embodiments, the third refractive index antireflection layer is made of silicon dioxide. Silicon dioxide is a mature hard film material with strong compatibility and structural stability.

[0083] In some alternative implementations, the fourth refractive index antireflective layer is made of silicon nitride. Silicon nitride, as the fourth layer, can provide the wear-resistant antireflective layer with high refractive index and ultra-high hardness.

[0084] In some optional embodiments, refer to Figure 1 , there is also a bottom layer 3 between the second refractive index enhancing layer and the substrate, and the bottom layer and the second refractive index enhancing layer are stacked. The setting of the bottom layer can further increase the transmittance of the optical film.

[0085] In some optional embodiments, the material of the bottom layer includes silicon dioxide. Using silicon dioxide as the bottom layer can improve the adhesion between the low refractive index enhancing layer and the substrate.

[0086] In some optional embodiments, the first refractive index enhancing layer includes a first nanopore structure, and the pore diameter of the first nanopore structure is less than 50 nm. The first refractive index enhancing layer including the above first nanopore structure can avoid visible light scattering and keep the optical film with high transmittance.

[0087] In some optional embodiments, the porosity of the first refractive index enhancing layer is x, and x satisfies: 60% < x ≤ 80%; the transmittance of the optical film can be achieved by adjusting the porosity within the above range.

[0088] In some specific embodiments, the pore diameter of the first nanopore structure is 10 nm - 30 nm; the first refractive index enhancing layer includes the above first nanopore structure

[0089] structure, which can maintain the stability of the film layer structure while ensuring a low refractive index and avoid pore collapse.

[0090] Exemplarily, the pore diameter of the first nanopore structure is any value among 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, etc. or the range composed of any two of them.

[0091] In some optional embodiments, the second refractive index enhancing layer includes a second nanopore structure, and the pore diameter of the second nanopore structure is less than 50 nm. The second refractive index enhancing layer including the above second nanopore structure can avoid visible light scattering and keep the optical film with high transmittance.

[0092] In some optional embodiments, the porosity of the second refractive index enhancing layer is y, and y satisfies: 40% ≤ y ≤ 60%; the transmittance of the optical film can be achieved by adjusting the porosity within the above range.

[0093] In some specific embodiments, the pore diameter of the second nanopore structure is 10 nm - 30 nm. The second refractive index enhancing layer including the above second nanopore structure can maintain the stability of the film layer structure while ensuring a low refractive index and avoid pore collapse.

[0094] For example, the pore size of the second nanopore structure is any value or a range of any two of the following: 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, etc.

[0095] The porous structure itself is superhydrophilic and easily adsorbs dirt. Therefore, in some optional embodiments, the first nanoporous structure and / or the second nanoporous structure includes hydrophobic groups. The above embodiments can enable the first refractive antireflective layer and / or the second refractive antireflective layer to possess both superhydrophobicity and antifouling properties.

[0096] In some alternative embodiments, the hydrophobic group includes a trimethylsilyl group. The trimethylsilyl group has strong hydrophobicity (contact angle >140°) and steric hindrance effect, which can effectively prevent the adsorption of dust particles. At the same time, the group enhances the stability of the pore structure through chemical bonding (Si-O-Si), avoiding the decrease in transmittance caused by pore collapse during environmental testing.

[0097] In some alternative embodiments, the total thickness of the fourth refractive index antireflective layer is greater than the total thickness of the third refractive index antireflective layer. This embodiment ensures that the probe primarily contacts the fourth refractive index antireflective layer during indentation testing, preventing the third refractive index antireflective layer from affecting the hardness reading of the optical film.

[0098] In some alternative embodiments, the total thickness of the first and second antireflective layers is 200 nm to 300 nm.

[0099] The antireflective layer within the aforementioned thickness range ensures the reflective effect of the optical film while also providing adhesion and stress buffering. For example, the total thickness of the first and second antireflective layers is any value from 200 nm, 220 nm, 250 nm, 270 nm, 300 nm, or any combination thereof.

[0100] In some alternative embodiments, the thickness of the substrate is less than or equal to 100 nm. A substrate thickness of this thickness can help further improve the adhesion between the antireflective layer and the substrate. On the other hand, it facilitates the design of a V-shaped antireflective film system in conjunction with a first and second antireflective layer, further reducing the reflectivity of the optical film and increasing its transmittance. Exemplarily, the thickness of the substrate is any value or a range of any combination of 100 nm, 80 nm, 70 nm, 60 nm, 50 nm, etc.

[0101] In some alternative embodiments, the total thickness of the abrasion-resistant anti-reflective layer is greater than or equal to 600 nm. Abrasion-resistant anti-reflective layers of this thickness possess stronger impact resistance, scratch resistance, and abrasion resistance. Exemplarily, the total thickness of the abrasion-resistant anti-reflective layer is any value or a range of any combination of 600 nm, 610 nm, 620 nm, 630 nm, 640 nm, 650 nm, 660 nm, 670 nm, 680 nm, 690 nm, 700 nm, 800 nm, and 900 nm.

[0102] In some alternative implementations, the thickness of the first refractive index antireflection layer is less than or equal to 150 nm.

[0103] The thickness of the first antireflective layer is controlled to be below 150 nm, which reduces the etching difficulty and ensures a more uniform first nanopore structure, resulting in a denser nanopore structure and stabilizing the refractive index below 1.2. For example, the thickness of the first antireflective layer can be any value or a range of any combination of 150 nm, 140 nm, 120 nm, 100 nm, 80 nm, 70 nm, 60 nm, 50 nm, 40 nm, 30 nm, 20 nm, and 10 nm.

[0104] In some alternative embodiments, the thickness of the second refracting antireflection layer is less than or equal to 100 nm. Controlling the thickness of the second refracting antireflection layer to below 100 nm reduces etching difficulty while ensuring greater uniformity of the second nanopore structure, achieving a denser nanopore structure, and stabilizing the refractive index between 1.3 and 1.4. Exemplarily, the thickness of the second refracting antireflection layer is any value or a range of any combination of 100 nm, 90 nm, 80 nm, 70 nm, 60 nm, 50 nm, 40 nm, 30 nm, 20 nm, and 10 nm.

[0105] In some alternative embodiments, the optical film satisfies at least one of the following conditions:

[0106] 1) The average transmittance of the optical film is greater than or equal to 99% in the 400nm-680nm range;

[0107] 2) The pencil hardness of the optical film is 7H-9H;

[0108] 3) The cross-cut adhesion of the optical film is 4B-5B;

[0109] 4) The thrust of the optical film is greater than or equal to 500N;

[0110] 5) The nanohardness of the optical film is greater than or equal to 12 GPa;

[0111] 6) The water droplet angle of the low-refractive antireflection layer of the optical film is greater than or equal to 140°;

[0112] 7) The water droplet angle of the wear-resistant anti-reflective layer of the optical film is greater than or equal to 110°.

[0113] Optical films can have specific performance indicators set based on actual application scenarios, such as camera lenses, display cover plates, optical lenses, and display screen protectors.

[0114] Secondly, the present invention provides a method for preparing an optical film, comprising the following steps:

[0115] A second refracting antireflection layer and a first refracting antireflection layer are disposed on one side of the substrate to form a low refractive antireflection layer;

[0116] A third refracting antireflective layer and a fourth refracting antireflective layer are stacked on the other side of the substrate to form a wear-resistant antireflective layer, thus obtaining an optical film.

[0117] The above preparation methods can produce optical films with high transmittance, high hardness, and high wear resistance. The process is highly controllable, suitable for large-area substrates, environmentally friendly, and low-cost.

[0118] In some alternative embodiments, the above preparation method first prepares a wear-resistant antireflective layer and then prepares a low-refractive-index antireflective layer, which can prevent scratches on the low-refractive-index antireflective layer.

[0119] In some optional embodiments, a second antireflective layer and a first antireflective layer are disposed on one side of the substrate, specifically including the following steps:

[0120] A second refractive index antireflection layer is formed on one side of a substrate by using a Si target and a Si-Al target through a single magnetron co-sputtering process; or, a bottom layer is formed on one side of a substrate by using a Si target through a single sputtering process, and a second refractive index antireflection layer is formed on one side of the bottom layer by using a Si target and a Si-Al target through a single magnetron co-sputtering process.

[0121] A first refractive index anti-reflection layer is formed on one side of the second refractive index anti-reflection layer by using a Si target and a Si-Al target through a secondary magnetron co-sputtering process.

[0122] Acid etching process is used to obtain a low-refractive antireflective layer.

[0123] The above method achieves precise deposition of each functional layer through magnetron sputtering. Specifically, by using magnetron co-sputtering and selective chemical etching, a second refractive index antireflective layer and a first refractive index antireflective layer with controllable refractive index can be prepared. Taking advantage of the acid insufficiency of alumina, it forms a water-soluble compound with acid, forming a nanoporous network structure in the second refractive index antireflective layer and the first refractive index antireflective layer, thereby reducing the overall refractive index of the low refractive index antireflective layer.

[0124] Compared to magnetron co-sputtering with Si and Al targets, magnetron co-sputtering with Si and Si-Al targets can better utilize the protective effect of Si atoms on Al atoms, thereby ensuring the stability of the physical thickness of the thin low-refractive-index antireflection layer.

[0125] Acid etching can be performed using any acid capable of etching alumina, such as phosphoric acid, sulfuric acid, or hydrochloric acid. The acid concentration and etching time can be adjusted according to the desired refractive index.

[0126] In some optional embodiments, a third refractive index antireflection layer and a fourth refractive index antireflection layer are disposed on the other side of the substrate, specifically including the following steps:

[0127] A third refractive index antireflection layer is formed on the other side of the substrate by a second sputtering process using a Si target.

[0128] A fourth refractive index antireflection layer is formed on one side of the third refractive index antireflection layer by three sputtering processes on the other side of the substrate using a Si target.

[0129] In some alternative embodiments, a single sputtering process includes: achieving a coating vacuum of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced. The gas flux of sputtering gas Ar2 is 100 sccm-300 sccm, and the gas flux of reactive gas O2 is 100 sccm-300 sccm. The sputtering power of the Si target is 5 KW-10 KW.

[0130] The above process can prepare a substrate of suitable thickness, improving the adhesion between the low-refractive antireflective layer and the substrate.

[0131] In some alternative implementations, a single magnetron co-sputtering process includes: achieving a coating vacuum of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced. The gas flux of sputtering gas Ar2 is 100sccm-300sccm, and the gas flux of reactive gas O2 is 100sccm-300sccm. The sputtering power of Si target is 4KW-10KW, and the sputtering power of Si-Al target is 5KW-10KW.

[0132] The above process, through co-sputtering of Si and Si-AL targets, reduces the impact of a large number of Al atoms being etched, thus ensuring the stability and refractive index of the second refractive index antireflection layer.

[0133] In some optional embodiments, the secondary magnetron co-sputtering process includes: achieving a coating vacuum of 1×10⁻⁶. -3Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced. The gas flux of sputtering gas Ar2 is 100sccm-300sccm, and the gas flux of reactive gas O2 is 100sccm-300sccm. The sputtering power of Si target is 2KW-6KW, and the sputtering power of Si-Al target is 5KW-10KW.

[0134] The above process, through co-sputtering of Si and Si-AL targets, reduces the impact of a large number of Al atoms being etched, thus ensuring the stability and refractive index of the first refractor antireflection layer.

[0135] In some optional embodiments, the secondary sputtering process includes: the secondary sputtering process includes: the coating vacuum degree reaching 1×10 -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced. The gas flux of sputtering gas Ar2 is 100sccm-300sccm, and the gas flux of reactive gas O2 is 100sccm-300sccm. The sputtering power of the Si target is 5KW-10KW.

[0136] By optimizing the sputtering power and gas flow rate, the process parameters make the stress distribution of the film layer more uniform.

[0137] In some alternative embodiments, the triple sputtering process includes: achieving a coating vacuum of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas N2 are introduced. The gas flux of sputtering gas Ar2 is 100 sccm-300 sccm, and the gas flux of reactive gas N2 is 100 sccm-300 sccm. The sputtering power of the Si target is 5 KW-10 KW.

[0138] By optimizing the sputtering power and gas flow rate, the process parameters make the stress distribution of the film layer more uniform.

[0139] In some optional embodiments, after forming the underlayer, the first antireflective layer, and the second antireflective layer on one side of the substrate, the following steps are further included:

[0140] A substrate having a base layer, a first refractive index antireflection layer, and a second refractive index antireflection layer is placed in an atmosphere containing hexamethyldisilazane (HMDS) to form hydrophobic groups.

[0141] In an atmosphere containing hexamethyldisilazane, the Si-N bonds in HMDS molecules break, and the trimethylsilyl group (-SiMe3) undergoes a nucleophilic substitution reaction with the silanol group (Si-OH) on the surface of SiO2 to form a Si-O-SiMe3 structure. This reaction significantly improves the hydrophobicity of the low-refractive antireflection layer on the product side.

[0142] The immersion time in an atmosphere containing hexamethyldisilazane can be adjusted according to the hydrophobicity of the desired low-refractive antireflective layer. For example, the immersion time in an atmosphere containing hexamethyldisilazane is 24h-36h.

[0143] The temperature of the atmosphere containing hexamethyldisilazane can be adjusted according to the reaction rate. To ensure a suitable reaction rate, the temperature can be controlled at 50°C or below.

[0144] Thirdly, the present invention provides a display device comprising an optical film prepared by the method of the first aspect or the method of the second aspect.

[0145] Display components include, but are not limited to: LCD display cover plates, OLED display cover plates, touch sensor modules, camera lenses, fingerprint recognition cover plates, flexible display protective layers, industrial human-machine interface touch screens, or medical endoscope lenses, etc.

[0146] In some alternative embodiments, the substrate includes a product side and a user side disposed opposite to each other; a low-refractive antireflective layer is disposed on the product side of the substrate; and a wear-resistant antireflective layer is disposed on the user side of the substrate.

[0147] Fourthly, the present invention provides an electronic device, including an optical film prepared by the method of the first aspect or the method of the second aspect or the display device of the third aspect.

[0148] Because this electronic device includes an optical film, it achieves a balance between optical and mechanical performance, significantly improving the user experience.

[0149] Electronic devices include, but are not limited to: smartphones, tablets, smartwatches, laptops, digital cameras, virtual reality / augmented reality devices, in-vehicle central control screens, head-up displays, autonomous driving sensors, smart home devices, industrial barcode scanners, medical monitors, or medical ultrasound equipment, etc.

[0150] The stacked battery provided by the present invention will be described in detail below through specific embodiments.

[0151] Example 1

[0152] This embodiment provides an optical film, which includes a substrate glass, a low-refractive-index antireflection layer, and an abrasion-resistant antireflection layer; wherein, the low-refractive-index antireflection layer is disposed on the product side of the substrate; the abrasion-resistant antireflection layer is disposed on the user side of the substrate; the low-refractive-index antireflection layer includes a bottom layer (silica), a second refractive-sub antireflection layer (silica), and a first refractive-sub antireflection layer (silica) that are sequentially stacked from top to bottom; the refractive index of the first refractive-sub antireflection layer is a, and the refractive index of the second refractive-sub antireflection layer is b; the abrasion-resistant antireflection layer includes a third refractive-sub antireflection layer (silica) and a fourth refractive-sub antireflection layer (silicon nitride) that are sequentially stacked from bottom to top, the refractive index of the third refractive-sub antireflection layer is c, and the refractive index of the fourth refractive-sub antireflection layer is d, where a < b < c < d, as shown in Table 1 specifically.

[0153] The first refractive-sub antireflection layer (porosity 80%) and the second refractive-sub antireflection layer (porosity 40%) include a nanoporous structure, and the pore diameter of the nanoporous structure is less than 50 nm; the nanoporous structure includes trimethylsilyl groups.

[0154] Its preparation method includes the following steps: Substrate cleaning

[0155] Take a glass substrate, remove the surface dust and dirt on a cleaning line, and after drying, obtain a clean glass substrate.

[0156] (2) Preparation of the abrasion-resistant antireflection layer

[0157] When the coating vacuum reaches 2×10 -3 Pa, turn the glass over and place it for the preparation of the abrasion-resistant antireflection layer on the user side.

[0158] The first SiO2 layer: Select a Si target as the target and form a SiO2 thin film by magnetron sputtering. When the coating vacuum reaches 2×10 -3 Pa, introduce the sputtering gas Ar2, the gas flux is 100 sccm, the reaction gas O2, the gas flux is 200 sccm. The Si target maintains a sputtering power of 8 KW. The film thickness is 100 nm.

[0159] The second Si3N4 layer: Select a Si target as the target and form a Si3N4 thin film by magnetron sputtering. Introduce the sputtering gas Ar2, the gas flux is 100 sccm, the reaction gas N2, the gas flux is 150 sccm. The Si target maintains a sputtering power of 8 KW. The film thickness is 12 nm.

[0160] The third SiO2 layer: Select a Si target as the target and form a SiO2 thin film by magnetron sputtering. Introduce the sputtering gas Ar2, the gas flux is 100 sccm, the reaction gas O2, the gas flux is 200 sccm. The Si target maintains a sputtering power of 8 KW. The film thickness is 40 nm.

[0161] The fourth Si3N4 layer: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 75 nm.

[0162] The fifth SiO2 layer: A SiO2 thin film was formed using a Si target via magnetron sputtering. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 10 nm.

[0163] The sixth layer, Si3N4: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 40 nm.

[0164] The seventh SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 100 nm.

[0165] The eighth Si3N4 layer: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 10 nm.

[0166] The ninth SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 45 nm.

[0167] The tenth layer, Si3N4: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 100 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 252 nm.

[0168] The eleventh SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas Ar2 was introduced at a flux of 100 sccm, and the reactive gas O2 was introduced at a flux of 200 sccm. The Si target was maintained at a sputtering power of 8 kW. The film thickness was 85 nm.

[0169] (1) Preparation of low refractive antireflective layer

[0170] Bottom layer: A Si target is used to form a SiO2 thin film by magnetron sputtering, achieving a deposition vacuum of 3×10⁻⁶. - 3 At Pa, sputtering gas Ar2 is introduced at a flow rate of 100 sccm, and reaction gas O2 is introduced at a flow rate of 200 sccm. The sputtering power of the Si target is maintained at 8 kW, and the bottom layer thickness is 80 nm.

[0171] Second refractive index antireflection layer: A Si-Al-O thin film was formed by magnetron co-sputtering using Si and Si-Al targets. Ar2 sputtering gas was introduced at a flux of 100 sccm, and O2 reaction gas was introduced at a flux of 200 sccm. The sputtering power of the Si target was maintained at 4 kW, and the sputtering power of the Si-Al target was 10 kW. The thickness of the second refractive index antireflection layer was 93 nm.

[0172] First refractor antireflection layer: Si-Al-O thin film is formed by magnetron co-sputtering using Si target and Si-Al target. Sputtering gas Ar2 is introduced with a gas flux of 100 sccm, and reaction gas O2 with a gas flux of 200 sccm. The sputtering power of Si target is maintained at 3 kW, and the sputtering power of Si-Al target is 10 kW. The thickness of the first refractor antireflection layer is 113 nm.

[0173] (4) Acid etching and hydrophobic treatment

[0174] The substrate deposited in step (3) above was placed in a phosphoric acid solution at 90°C for 5 minutes for etching. After removal, it was rinsed with deionized water for 5 minutes and finally dried with an air gun.

[0175] After drying, place the product in a sealed HMDS atmosphere and let it stand for 24 hours. After removing it, rinse it with deionized water for 5 minutes and finally dry it with an air gun.

[0176] Example 2

[0177] This embodiment provides an optical film, which differs from Embodiment 1 only in that the refractive index α of the first refracting antireflection layer is changed, and the porosity of the first refracting antireflection layer is 72% accordingly, as detailed in Table 1.

[0178] The only difference between its preparation method and that of Example 1 is:

[0179] Bottom layer: A Si target is used to form a SiO2 thin film by magnetron sputtering, achieving a deposition vacuum of 3×10⁻⁶. - 3At Pa, sputtering gas Ar2 is introduced at a flow rate of 100 sccm, and reaction gas O2 is introduced at a flow rate of 200 sccm. The sputtering power of the Si target is maintained at 8 kW, and the bottom layer thickness is 80 nm.

[0180] Second refractive index antireflection layer: A Si-Al-O thin film was formed by magnetron co-sputtering using Si and Si-Al targets. Ar2 sputtering gas was introduced at a flux of 100 sccm, and O2 reaction gas was introduced at a flux of 200 sccm. The sputtering power of the Si target was maintained at 4 kW, and the sputtering power of the Si-Al target was 10 kW. The thickness of the second refractive index antireflection layer was 93 nm.

[0181] First refractor antireflection layer: Si-Al-O thin film is formed by magnetron co-sputtering using Si target and Si-Al target. Sputtering gas Ar2 is introduced with a gas flux of 100 sccm, and reaction gas O2 is introduced with a gas flux of 200 sccm. The sputtering power of Si target is maintained at 3 kW, and the sputtering power of Si-Al target is 9.5 kW. The thickness of the first refractor antireflection layer is 113 nm.

[0182] Everything else is the same as in Example 1.

[0183] Example 3

[0184] This embodiment provides an optical film, which differs from Embodiment 1 only in that the refractive index b of the second refracting antireflection layer is changed, and the porosity of the second refracting antireflection layer is 52% accordingly, as detailed in Table 1.

[0185] The only difference between its preparation method and that of Example 1 is:

[0186] Bottom layer: A Si target is used to form a SiO2 thin film by magnetron sputtering, achieving a deposition vacuum of 3×10⁻⁶. - 3 At Pa, sputtering gas Ar2 is introduced at a flow rate of 100 sccm, and reaction gas O2 is introduced at a flow rate of 200 sccm. The sputtering power of the Si target is maintained at 8 kW, and the bottom layer thickness is 80 nm.

[0187] Second refractive index antireflection layer: A Si-Al-O thin film was formed by magnetron co-sputtering using Si and Si-Al targets. Ar2 sputtering gas was introduced at a flux of 100 sccm, and O2 reaction gas was introduced at a flux of 200 sccm. The sputtering power of the Si target was maintained at 4.5 kW, and the sputtering power of the Si-Al target was 10 kW. The thickness of the second refractive index antireflection layer was 93 nm.

[0188] First refractor antireflection layer: Si-Al-O thin film is formed by magnetron co-sputtering using Si target and Si-Al target. Sputtering gas Ar2 is introduced with a gas flux of 100 sccm, and reaction gas O2 with a gas flux of 200 sccm. The sputtering power of Si target is maintained at 3 kW, and the sputtering power of Si-Al target is 10 kW. The thickness of the first refractor antireflection layer is 113 nm.

[0189] Everything else is the same as in Example 1.

[0190] Example 4

[0191] This embodiment provides an optical film, which differs from Embodiment 1 only in that: the refractive index a of the first refracting antireflection layer and the refractive index b of the second refracting antireflection layer are changed, the porosity of the first refracting antireflection layer is 65% and the porosity of the second refracting antireflection layer is 41%, as detailed in Table 1.

[0192] The only difference between its preparation method and that of Example 1 is:

[0193] Bottom layer: A Si target is used to form a SiO2 thin film by magnetron sputtering, achieving a deposition vacuum of 3×10⁻⁶. - 3 At Pa, sputtering gas Ar2 is introduced at a flow rate of 100 sccm, and reaction gas O2 is introduced at a flow rate of 200 sccm. The sputtering power of the Si target is maintained at 8 kW, and the bottom layer thickness is 80 nm.

[0194] Second refractor antireflection layer: A Si-Al-O thin film was formed by magnetron co-sputtering using Si and Si-Al targets. The sputtering gas Ar2 was introduced at a flux of 100 sccm, and the reactant gas O2 was introduced at a flux of 200 sccm. The sputtering power of the Si target was maintained at 5 kW, and the sputtering power of the Si-Al target was 10 kW. The thickness of the second refractor antireflection layer was 93 nm.

[0195] First refractor antireflection layer: Si-Al-O thin film is formed by magnetron co-sputtering using Si target and Si-Al target. Sputtering gas Ar2 is introduced with a gas flux of 100 sccm, and reaction gas O2 with a gas flux of 200 sccm. The sputtering power of Si target is maintained at 3 kW, and the sputtering power of Si-Al target is 9 kW. The thickness of the first refractor antireflection layer is 113 nm.

[0196] Everything else is the same as in Example 1.

[0197] Example 5

[0198] This embodiment provides an optical film, which differs from Embodiment 1 only in that the refractive index d of the fourth refractor antireflection layer is changed, as detailed in Table 1.

[0199] The preparation method differs from that in Example 1 only in that the gas flux of N2 during the preparation of all Si3N4 layers is changed to 100 sccm; otherwise, it is the same as in Example 1.

[0200] Example 6

[0201] This embodiment provides an optical film, which differs from Embodiment 1 only in that: the thickness of the bottom layer is 100 nm; and the thickness of the second refractive index antireflection layer is 100 nm.

[0202] The thickness of the first refractive index antireflection layer is 150 nm.

[0203] Example 7

[0204] This embodiment provides an optical film, which differs from Embodiment 1 only in that:

[0205] The first SiO2 layer: A SiO2 thin film is formed by magnetron sputtering using a Si target, achieving a deposition vacuum of 4 × 10⁻⁶. -3 At Pa, sputtering gas Ar2 is introduced at a flux of 150 sccm, and reactant gas O2 is introduced at a flux of 200 sccm. The sputtering power of the Si target is maintained at 5 kW. The film thickness is 100 nm.

[0206] The second Si3N4 layer: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas Ar2 was introduced at a flux of 150 sccm, and the reactive gas N2 was introduced at a flux of 150 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 12 nm.

[0207] The third SiO2 layer: A SiO2 thin film was formed using a Si target via magnetron sputtering. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 40 nm.

[0208] The fourth Si3N4 layer: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 75 nm.

[0209] The fifth SiO2 layer: A SiO2 thin film was formed using a Si target via magnetron sputtering. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 10 nm.

[0210] The sixth layer, Si3N4: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 40 nm.

[0211] The seventh SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 100 nm.

[0212] The eighth layer, Si3N4: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 10 nm.

[0213] The ninth SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was O2 at a flux of 200 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 45 nm.

[0214] The tenth layer, Si3N4: A Si3N4 thin film was formed by magnetron sputtering using a Si target. The sputtering gas was Ar2 at a flux of 150 sccm, and the reactive gas was N2 at a flux of 150 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 252 nm.

[0215] The eleventh SiO2 layer: A SiO2 thin film was formed by magnetron sputtering using a Si target. The sputtering gas Ar2 was introduced at a flux of 150 sccm, and the reactant gas O2 was introduced at a flux of 200 sccm. The Si target was maintained at a sputtering power of 5 kW. The film thickness was 85 nm.

[0216] Example 8

[0217] The only difference from Example 1 is the preparation of the low-refractive antireflective layer.

[0218] Bottom layer: A Si target is used to form a SiO2 thin film by magnetron sputtering, achieving a deposition vacuum of 3×10⁻⁶. - 3 At Pa, sputtering gas Ar2 is introduced at a flow rate of 100 sccm, and reaction gas O2 is introduced at a flow rate of 200 sccm. The sputtering power of the Si target is maintained at 8 kW, and the bottom layer thickness is 80 nm.

[0219] Second refractive index antireflection layer: A Si-Al-O thin film is formed by magnetron co-sputtering using Si and Al targets. Ar2 sputtering gas is introduced at a flux of 100 sccm, and O2 reaction gas is introduced at a flux of 200 sccm. The sputtering power of the Si target is maintained at 4 kW, and the sputtering power of the Al target is 10 kW. The thickness of the second refractive index antireflection layer is 93 nm.

[0220] First refractor antireflection layer: Si-Al-O thin film is formed by magnetron co-sputtering using Si and Al targets. Sputtering gas Ar2 is introduced with a gas flux of 100 sccm, and reaction gas O2 with a gas flux of 200 sccm. The sputtering power of the Si target is maintained at 3 kW, and the sputtering power of the Al target is 10 kW. The thickness of the first refractor antireflection layer is 113 nm.

[0221] Figure 5 The images show microscopic SEM images of the low-refractive-index antireflection layer before acid etching in Examples 1 and 8; where a is the microscopic SEM image of the low-refractive-index antireflection layer before acid etching in Example 1, and b is the microscopic SEM image of the low-refractive-index antireflection layer before acid etching in Example 10; by comparing the microscopic images of the two samples, it can be seen that the optical film thickness of Example 1, which is co-sputtered using Si and Si-AL targets, is more uniform.

[0222] Example 9

[0223] The optical film differs from that of Example 1 only in that it does not contain a substrate.

[0224] Comparative Example 1

[0225] The optical film differs from that in Example 1 only in that the first and second antireflective layers are made of TiO2; the refractive indices a and b of the two are shown in Table 1.

[0226] The only difference between its preparation method and Example 1 is that the magnetron sputtering targets for both the first and second refracting antireflection layers are Ti targets.

[0227] Comparative Example 2

[0228] The only difference between the optical film and Example 1 is that it does not include a low-refractive anti-reflective layer.

[0229] Comparative Example 3

[0230] The only difference between the optical film and Example 1 is that it does not include the wear-resistant anti-reflective layer.

[0231] Comparative Example 4

[0232] The optical film differs from Example 1 only in that it does not include a low-refractive antireflective layer, and the fourth refractor antireflective layer is made of TiO2. 2， The refractive index d is shown in Table 1.

[0233] The only difference between its preparation method and Example 1 is that the magnetron sputtering target for preparing the fourth refractive index antireflection layer is a Ti target.

[0234] Test case

[0235] Test the following properties of the above optical films:

[0236] Color: The product color was tested using an X-Rite CM2300 colorimeter.

[0237] Refractive index: The refractive index of the material was measured using a JAWoollam ellipsometer.

[0238] Pencil Hardness: Using Mitsubishi test pencil lead of specified hardness, apply 1 kgf of pressure with the lead at a 45° angle to the surface to be tested. Make 5 strokes at the test location, each stroke 5-10 mm long. No indentations or scratches are allowed on the outer surface; indentations that can recover within 24 hours are not considered problematic. Minor scratches at the starting point (1 / 3 of the total length) are permissible. For camera lenses, both the small lens and the coating must meet the requirements, and no traces should remain when viewed from any angle.

[0239] Cross-cut adhesion test: Use a sharp blade (blade angle 20°-30°, blade thickness 0.43±0.03mm) to make 10×10 1mm×1mm grids on the surface of the test sample, each line should be deep enough to reach the bottom layer of the coating; use a brush to clean the debris in the test area; firmly stick the test grids with adhesive tape with an adhesion strength of (10±1)N / 25mm, and squeeze the tape with your fingernail (note that the fingernail should not damage the tape; for glass PET film or soft substrate film, use an eraser or cotton swab to remove air bubbles) to remove air bubbles between the tape and the coating, so as to increase the contact area and strength between the tape and the test area; after standing for (90±30) seconds, hold one end of the tape with your hand and pull off the tape in a 60° opposite direction within 0.5 seconds. Perform the test once, and then use a 5x magnifying glass to check the paint coating peeling.

[0240] Visible light transmittance: The visible light transmittance (400nm-680nm) and LAB value of the coated products were measured using a Carry 5000 UV-Vis spectrophotometer; among which, Figure 6 The transmittance curve of the optical film in Example 1 is shown. Figures 7 to 10 The transmittance curves are for the optical films of Comparative Examples 1 to 4, respectively.

[0241] Thrust test: A reliability test to evaluate product strength. After inspecting the sample for any abnormalities in appearance, attach the camera lens to the back cover or camera trim. Using a metal rod indenter (8mm diameter, 10mm radius), apply pressure at a speed of 10mm / min to the center of the lens (center of the camera lens window), continuously applying pressure until failure. Record the force value at failure after the test.

[0242] Nanoscale hardness testing: Tested using a Ti980 nanoindenter. Testing was conducted according to GB / T 22458-2008, using a quasi-static dotting mode and a standard diamond probe as the indenter.

[0243] Water droplet angle test: Use a water droplet angle tester.

[0244] 1. Before testing, inspect the sample surface and wipe it clean with a dry cloth; ensure the sample testing area is clean;

[0245] 2. Place the sample on the test platform (ensuring the sample is placed horizontally), set the water flow rate to 2 microliters, and conduct the test;

[0246] 3. Test data: Simply record the data.

[0247] Figure 2 This is a microscopic SEM image of the first refractive index sub-antireflection layer in Example 1;

[0248] Figure 3 This is a single-sided reflectance curve of the low-refractive antireflection layer in Example 1;

[0249] Figure 4 This is a microscopic SEM image of the first refractive index sub-antireflection layer before acid etching in Example 1;

[0250] Figure 6 This is a transmittance curve from Example 1.

[0251] The test results are shown in Table 1.

[0252] Table 1:

[0253]

[0254] As shown in Table 1, compared with the comparative example, the optical film obtained in the embodiment significantly improves its hardness and wear resistance while ensuring the transmittance of the optical film through the double-sided synergistic film layer design and multi-layer alternating structure.

[0255] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical film, characterized in that, The system includes a substrate, a low-refractive-index anti-reflective layer, and a wear-resistant anti-reflective layer; wherein the low-refractive-index anti-reflective layer and the wear-resistant anti-reflective layer are located on opposite sides of the substrate; from the direction near the substrate to the direction away from the substrate, the low-refractive-index anti-reflective layer includes a second refractive-index anti-reflective layer and a first refractive-index anti-reflective layer stacked together; the refractive index of the first refractive-index anti-reflective layer is a, and the refractive index of the second refractive-index anti-reflective layer is b; the wear-resistant anti-reflective layer includes a third refractive-index anti-reflective layer and a fourth refractive-index anti-reflective layer stacked together, the total number of layers of the third refractive-index anti-reflective layer and the fourth refractive-index anti-reflective layer is greater than or equal to 4; the refractive index of the third refractive-index anti-reflective layer is c, and the refractive index of the fourth refractive-index anti-reflective layer is d, a <b<c<d。 2. The optical film according to claim 1, characterized in that, 1.1≤a≤1.2； And / or, 1.3 ≤ b < 1.4; And / or, 1.4 ≤ c < 1.5; And / or, 1.8≤d≤2.

1.

3. The optical film according to claim 1 or 2, characterized in that, The material of the first antireflective layer for the refractive index includes silicon dioxide; And / or, the material of the second refractive antireflective layer includes silicon dioxide; And / or, the material of the third refractive index antireflective layer includes silicon dioxide; And / or, the material of the fourth refractive index antireflective layer includes silicon nitride; And / or, an underlayer is further included between the second refractive index antireflection layer and the substrate, the underlayer and the second refractive index antireflection layer being stacked; preferably, the material of the underlayer includes silicon dioxide.

4. The optical film according to any one of claims 1-3, characterized in that, The first refractive antireflection layer includes a first nanopore structure, the pore size of which is less than 50 nm; preferably, the pore size of the first nanopore structure is 10 nm-30 nm. And / or, the porosity of the first antireflective layer is x, where x satisfies: 60% <x≤80%; And / or, the second refractive antireflection layer includes a second nanopore structure, wherein the pore size of the second nanopore structure is less than 50 nm; preferably, the pore size of the second nanopore structure is 10 nm-30 nm. And / or, the porosity of the second refractive antireflection layer is y, where y satisfies: 40%≤y≤60%.

5. The optical film according to claim 4, characterized in that, The first nanoporous structure and / or the second nanoporous structure include hydrophobic groups, preferably, the hydrophobic groups include trimethylsilyl groups.

6. The optical film according to any one of claims 3-5, characterized in that, The total thickness of the fourth anti-reflective layer is greater than the total thickness of the third anti-reflective layer; And / or, the total thickness of the first refracting antireflection layer and the second refracting antireflection layer is 200nm-300nm; And / or, the thickness of the underlying layer is less than or equal to 100 nm; And / or, the total thickness of the wear-resistant and anti-reflective layer is greater than or equal to 600 nm.

7. The optical film according to claim 6, characterized in that, The thickness of the first antireflective layer of the refractive index is less than or equal to 150 nm; And / or, the thickness of the second refractive antireflection layer is less than or equal to 100 nm.

8. The optical film according to any one of claims 1-7, characterized in that, The optical film satisfies at least one of the following conditions: 1) The average transmittance of the optical film is greater than or equal to 99% in the 400nm-680nm range; 2) The pencil hardness of the optical film is 7-9H; 3) The cross-cut adhesion of the optical film is 4-5B; 4) The thrust of the optical film is greater than or equal to 500N; 5) The nanohardness of the optical film is greater than or equal to 12 GPa; 6) The water droplet angle of the low-refractive antireflection layer of the optical film is greater than or equal to 140°; 7) The water droplet angle of the wear-resistant and anti-reflective layer of the optical film is greater than or equal to 110°.

9. A method for preparing an optical film as described in any one of claims 1-8, characterized in that, Includes the following steps: A second refracting antireflection layer and a first refracting antireflection layer are disposed on one side of the substrate to form the low refractive antireflection layer; A third refracting antireflective layer and a fourth refracting antireflective layer are stacked on the other side of the substrate to form the wear-resistant antireflective layer, thereby obtaining the optical film.

10. The preparation method according to claim 9, characterized in that, The provision of a second antireflective layer and a first antireflective layer on one side of the substrate specifically includes the following steps: The second refractive index antireflection layer is formed on one side of the substrate by a single magnetron co-sputtering process using a Si target and a Si-Al target; or, the substrate is formed on one side by a single sputtering process using a Si target, and the second refractive index antireflection layer is formed on one side of the substrate by a single magnetron co-sputtering process using a Si target and a Si-Al target. The first refractive index antireflection layer is formed on one side of the second refractive index antireflection layer by using a Si target and a Si-Al target through a secondary magnetron co-sputtering process. The low-refractive-index antireflective layer is obtained by acid etching. And / or, a third refractive index antireflection layer and a fourth refractive index antireflection layer are disposed on the other side of the substrate, specifically including the following steps: The third refractive index antireflection layer is formed on the other side of the substrate by a secondary sputtering process using a Si target. The fourth refractive index antireflection layer is formed on one side of the third refractive index antireflection layer by three sputtering processes on the other side of the substrate using a Si target.

11. The preparation method according to claim 10, characterized in that, The primary sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5 KW-10 KW. And / or, the first magnetron co-sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 4 kW-10 kW, and the sputtering power of the Si-Al target is 5 kW-10 kW. And / or, the secondary magnetron co-sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 2 kW-6 kW and the sputtering power of the Si-Al target is 5 kW-10 kW. And / or, the secondary sputtering process includes: achieving a coating vacuum degree of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas O2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas O2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5KW-10KW. And / or, the three sputtering processes include: achieving a coating vacuum of 1×10⁻⁶. -3 Pa-5×10 -3 At Pa, sputtering gas Ar2 and reactive gas N2 are introduced, with the gas flux of sputtering gas Ar2 being 100 sccm-300 sccm and the gas flux of reactive gas N2 being 100 sccm-300 sccm; the sputtering power of the Si target is 5 kW-10 kW.

12. The preparation method according to any one of claims 9-11, characterized in that, After the first and second antireflective layers are formed on one side of the substrate, the method further includes the following steps: The substrate having the first and second antireflective layers is placed in an atmosphere containing hexamethyldisilazane to form hydrophobic groups.

13. A display element, characterized in that, The optical film includes the optical film according to any one of claims 1-8 or the optical film prepared by the preparation method according to any one of claims 9-12.

14. The display element according to claim 13, characterized in that, The low-refractive antireflective layer is disposed on the product side of the substrate; the abrasion-resistant antireflective layer is disposed on the user side of the substrate.

15. An electronic device, characterized in that, Includes the optical film according to any one of claims 1-8, or the optical film prepared by the preparation method according to any one of claims 9-12, or the display device according to claim 13 or 14.

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