Anti-reflection film, preparation method, anti-reflection optical article and application

Abstract

The present invention discloses an antireflection film, a preparation method, an antireflection optical article and an application. The antireflection film comprises a low refractive index film layer and a high refractive index film layer which are alternately stacked, and the refractive index of the low refractive index film layer is lower than that of the high refractive index film layer; the bottom film layer and the top film layer of the antireflection film are both low refractive index film layers; the high refractive index film layer disposed under the top film layer is a silicon nitride film layer with a thickness of 500 nm to 2000 nm; the antireflection film has a nano-hardness of more than 11 GPa and a light transmittance of more than 94% in the wavelength range of 400 nm to 700 nm. The above antireflection optical film designs the high refractive index film layer located under the top film layer as a silicon nitride layer and greatly increases its thickness, which can effectively improve the nano-hardness of the antireflection optical article on the premise of ensuring the light transmittance.

Description

Technical Field

[0001] The present invention relates to the technical field of optical product coating, and particularly to an antireflection film, a preparation method, an antireflection optical product and an application thereof. Background Art

[0002] An antireflection film, also known as an antireflection coating, is used to reduce the intensity of reflected light on the surface of an optical element and increase the light transmittance of the optical element within the working wavelength band. It is the most widely used type of optical thin film. The antireflection film mainly reduces the reflectivity of light at the interface by designing a composite film layer, causing light to interfere in multiple film layers with different refractive indices, thereby enhancing the intensity of transmitted light and reducing the intensity of reflected light to achieve the antireflection effect. Traditional materials for preparing antireflection films include TiO 2 , HfO 2 , ZrO 2 , Nb 2 O 5 , Ta 2 O 5 , Al 2 O 3 , SiO 2 etc. The methods for preparing each film layer in the antireflection film are generally sputtering coating or evaporation coating.

[0003] Nowadays, in application fields such as camera lenses, mobile phone screens, protective cover glasses for in-vehicle and industrial touch display screens, etc., an antireflection film with both high light transmittance and high nano-hardness is usually required. In traditional technologies, a wear-resistant layer is usually added on the surface of the antireflection film, such as a diamond-like carbon coating, a combination of a diamond-like carbon coating and an AF fingerprint-resistant layer, carbonitride, silicon nitride, etc., to improve the nano-hardness and wear resistance of the antireflection film. In addition to adding a wear-resistant layer on the surface of the antireflection film, a wear-resistant layer can also be sandwiched between the antireflection film and the substrate to improve the wear resistance of the antireflection film product. However, an additional wear-resistant layer will affect the interference of light at the interface of the antireflection film, thus significantly affecting the light transmittance of the antireflection film. Therefore, the thickness of the wear-resistant layer is relatively thin, which limits the further improvement of the nano-hardness of the antireflection film, and an additional film also adds an additional preparation process. Summary of the Invention

[0004] Based on this, it is necessary to provide an antireflection film that can improve the nano-hardness and wear resistance of the surface of the product without adding an additional wear-resistant layer. Further, a preparation method and an application thereof are provided.

[0005] According to an embodiment of the present invention, an antireflection optical article includes a low refractive index film layer and a high refractive index film layer alternately stacked, wherein the refractive index of the low refractive index film layer is lower than that of the high refractive index film layer; the bottom film layer and the top film layer of the antireflection film are both the low refractive index film layer; the high refractive index film layer disposed under the top film layer is a silicon nitride film layer with a thickness of 500 nm to 2000 nm; the antireflection film has a nano-hardness of more than 11 GPa, and the average light transmittance of the antireflection film in the wavelength range of 400 nm to 700 nm is more than 94%.

[0006] In one embodiment, the antireflection film further includes an anti-fingerprint layer disposed on the top film layer.

[0007] In one embodiment, the antireflection film can pass a linear abrasion test of more than 2000 cycles.

[0008] In one embodiment, the low refractive index film layer includes a first low refractive index film layer, a second low refractive index film layer, a third low refractive index film layer, and a fourth low refractive index film layer, and the high refractive index film layer includes a first high refractive index film layer, a second high refractive index film layer, and a third high refractive index film layer; the antireflection film sequentially includes a first low refractive index film layer, a first high refractive index film layer, a second low refractive index film layer, a second high refractive index film layer, a third low refractive index film layer, a third high refractive index film layer, and a fourth low refractive index film layer.

[0009] In one embodiment, the first low refractive index film layer is the bottom film layer, the third high refractive index film layer is the silicon nitride film layer, and the fourth low refractive index film layer is the top film layer; the low refractive index film layers are all silica film layers; and / or

[0010] The materials of the first high refractive index film layer and the second high refractive index film layer are independently selected from a zirconia film layer, a titanium oxide film layer, a tantalum oxide film layer, a niobium oxide film layer, a hafnium oxide film layer, or a silicon nitride film layer.

[0011] In one embodiment, the low refractive index film layers are all silica film layers, and the high refractive index film layers are all silicon nitride film layers.

[0012] In one embodiment, the first low refractive index film layer is the bottom film layer, the third high refractive index film layer is the silicon nitride film layer, the fourth low refractive index film layer is the top film layer. The thickness of the first low refractive index film layer is 10 nm to 90 nm, the thickness of the first high refractive index film layer is 5 nm to 30 nm, the thickness of the second low refractive index film layer is 20 nm to 70 nm, the thickness of the second high refractive index film layer is 15 nm to 150 nm, the thickness of the third low refractive index film layer is 10 nm to 40 nm, and the thickness of the fourth low refractive index film layer is 70 nm to 100 nm.

[0013] A method for preparing an antireflection optical film, comprising the following steps:

[0014] Deposit each film layer of the antireflection film on the surface of the substrate in sequence. The antireflection film includes alternately stacked low refractive index film layers and high refractive index film layers, and both the bottom film layer and the top film layer of the antireflection film are the low refractive index film layers; the high refractive index film layer disposed under the top film layer is the silicon nitride film layer;

[0015] The method for depositing each film layer is inductively coupled plasma-assisted magnetron sputtering, and an anode layer linear ion source is used for auxiliary linear ion beam bombardment while magnetron sputtering; control the deposition time so that the thickness of the silicon nitride film layer is 500 nm to 2000 nm.

[0016] In one embodiment, before depositing each film layer of the antireflection film, it further includes the step of pretreating the surface of the substrate with an anode layer linear ion source.

[0017] In one embodiment, during the pretreatment, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 600 V to 2000 V, and the time is 3 min to 10 min.

[0018] In one embodiment, the low refractive index film layer is a silicon dioxide film layer, and the process for depositing the low refractive index film layer is as follows: the oxygen flow rate is 100 sccm to 300 sccm, the power of the silicon target is 3 kW to 12 kW, the power of the inductively coupled plasma source is 2 kW to 5 kW, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film-forming temperature is 150 °C to 300 °C; and / or

[0019] The high refractive index film layer is a silicon nitride film layer. The process for depositing the high refractive index film layer is as follows: the nitrogen gas flow rate is 100 sccm to 300 sccm, the power of the silicon target is 3 kW to 12 kW, the power of the inductively coupled plasma source is 2 kW to 5 kW, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film forming temperature is 150 °C to 300 °C.

[0020] An antireflection optical article, which includes a substrate and an antireflection film disposed on at least one surface of the substrate. The antireflection film is the antireflection film according to any one of the above embodiments, or an antireflection film prepared by the preparation method of the antireflection film according to any one of the above embodiments.

[0021] On the other hand, an application of an antireflection optical article in a display screen, a camera lens or a window glass. The antireflection optical article is the antireflection optical article according to any one of the above embodiments.

[0022] A display screen, which includes a protective cover plate and a display screen functional body;

[0023] The protective cover plate covers the surface of the display screen functional body, and the protective cover plate is an antireflection optical article or is processed from the antireflection optical article. The antireflection optical article is the antireflection optical article according to any one of the above embodiments.

[0024] A camera lens, which is an antireflection optical article or is processed from the antireflection optical article. The antireflection optical article is the antireflection optical article according to any one of the above embodiments.

[0025] Or, a window glass, which is an antireflection optical article or is processed from the antireflection optical article. The antireflection optical article is the antireflection optical article according to any one of the above embodiments.

[0026] The above antireflection optical film designs the high refractive index film layer under the top film layer as a silicon nitride layer and greatly increases its thickness to effectively improve the nano-hardness of the antireflection film. The antireflection film can exhibit a nano-hardness of more than 11 GPa. Since the antireflection film does not adopt the method of setting a wear-resistant layer to increase the nano-hardness, but improves the thickness of the silicon nitride film layer, it can have a high nano-hardness while ensuring the light transmittance, which is equivalent to simplifying the preparation process. At the same time, the silicon nitride film layer has a variable thickness of 500 nm to 2000 nm, and can be correspondingly selected and designed to obtain different nano-hardnesses. Description of the Drawings

[0027] Figure 1 A schematic diagram of an antireflection optical article for an embodiment;

[0028] Figure 2 Flow chart of the preparation method of an antireflection optical article according to an embodiment;

[0029] Figure 3 Schematic diagram of the light transmittance of the optical articles of Test Example 1 and Comparative Example 3 at different wavelength bands;

[0030] Figure 4 Schematic diagram of the light transmittance of the optical articles of Test Example 2 and Comparative Example 3 at different wavelength bands. Detailed implementation manners

[0031] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the understanding of the disclosure of the present invention is more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items. The "plurality" used herein includes more than two items. The "above a certain number" used herein should be understood as a certain number and a range greater than that certain number.

[0033] Adding a transparent wear-resistant layer in the middle or on the surface of the optical antireflection film is a commonly used method in traditional technologies to improve the wear resistance of the antireflection film. Most traditional multi-layer antireflection film systems are alternately composed of high-refractive-index materials and low-refractive-index materials with relatively uniform thicknesses. Since the antireflection effect of the antireflection film depends on the combination of the materials and thicknesses of each film layer, so that light undergoes multiple refractions, reflections and interferences therein to reduce the reflectance of light. Usually, when changing the material or thickness of one of the film layers, a large amount of debugging is still required to simultaneously adjust the materials and thicknesses of other film layers, and the workload is extremely large. Therefore, traditional technologies often adopt the method of setting an additional wear-resistant layer to improve the nano-hardness and wear resistance of the antireflection film. At the same time, improving and optimizing the composition and structure of the wear-resistant layer is an important means to improve the wear resistance of traditional multi-layer antireflection films. However, this method has a higher preparation cost, a more complex preparation process and a limited improvement in wear resistance.

[0034] The present invention provides a new technical concept for improving the nano-hardness and wear resistance of the antireflection film through structural design, and its structure is as follows.

[0035] An antireflection optical article, comprising: a substrate and an antireflection film disposed on the surface of the substrate, the antireflection film including a thickened silicon nitride film layer.

[0036] The antireflection film includes alternately stacked low refractive index film layers and high refractive index film layers, and the bottom film layer and the top film layer of the antireflection film layer are both low refractive index film layers. The high refractive index film layer disposed under the top film layer is a silicon nitride film layer with a thickness of 500 nm to 2000 nm. Moreover, the antireflection film has a nano-hardness of 11 GPa or more. It can be understood that when the antireflection film is disposed on the substrate, the film layer close to the substrate is the bottom film layer, and the film layer farthest from the substrate is the top film layer.

[0037] Furthermore, the antireflection film has a nano-hardness of 11.4 GPa or more; still further, the antireflection film has a nano-hardness of 12 GPa or more; even further, the antireflection film has a nano-hardness of 12.2 GPa or more.

[0038] In the traditional technology, a wear-resistant layer is often disposed above or in the middle of the antireflection film, but the introduction of the wear-resistant layer will affect the antireflection effect, resulting in a decrease in the light transmittance. In this embodiment, the antireflection film 200 should have excellent antireflection performance in the visible light range, for example, in the wavelength range of 400 nm to 700 nm (more specifically, for example, between about 420 nm and about 700 nm, or between about 450 nm and about 680 nm), and the average light transmittance of the antireflection film 200 is above 94%.

[0039] Herein, the low refractive index film layer and the high refractive index film layer are relative concepts and do not represent a specific refractive index value range. The refractive index of the low refractive index film layer is lower than that of the high refractive index film layer.

[0040] In some specific examples, the total number of the low refractive index film layers in the antireflection film disposed on the substrate is three or more. More specifically, please refer to Figure 1, a detailed structural schematic diagram of an antireflection optical article. The antireflection optical article 10 includes a substrate 100 and an antireflection film 200 disposed on the first surface 110 of the substrate 100. Among them, the antireflection film 200 includes a first low refractive index film layer 210, a first high refractive index film layer 220 disposed on the first low refractive index film layer 210, a second low refractive index film layer 230 disposed on the first high refractive index film layer 220, a second high refractive index film layer 240 disposed on the second low refractive index film layer 230, a third low refractive index film layer 250 disposed on the second high refractive index film layer 240, a third high refractive index film layer 260 disposed on the third low refractive index film layer 250, and a fourth low refractive index film layer 270 disposed on the third high refractive index film layer 260. It can be understood that in this specific embodiment, the first low refractive index film layer 210 is the bottom film layer, the fourth low refractive index film layer 270 is the top film layer, and the third high refractive index film layer 260 is the silicon nitride layer. Then, the thickness of the third high refractive index film layer 260 is 500 nm to 2000 nm.

[0041] In some specific examples, the thickness of the first low refractive index film layer 210 is 10 nm to 90 nm. Optionally, the thickness of the first low refractive index film layer 210 is 30 nm to 80 nm. Further, the thickness of the first low refractive index film layer 210 is 40 nm to 70 nm, such as 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, or 70 nm, including all ranges and sub-ranges therebetween.

[0042] In some specific examples, the thickness of the first high refractive index film layer 220 is 5 nm to 30 nm. Optionally, the thickness of the first high refractive index film layer 220 is 5 nm to 20 nm. Further, the thickness of the first high refractive index film layer 220 is 10 nm to 20 nm, such as 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, or 20 nm, including all ranges and sub-ranges therebetween.

[0043] In some specific examples, the thickness of the second low refractive index film layer 230 is 20 nm to 70 nm. Optionally, the thickness of the second low refractive index film layer 230 is 30 nm to 70 nm. Further, the thickness of the second low refractive index film layer 230 is 40 nm to 70 nm, such as 40 nm, 45 nm, 50 nm, 55 nm, 59 nm, 65 nm, or 70 nm, including all ranges and sub-ranges therebetween.

[0044] In some specific examples, the thickness of the second high refractive index film layer 240 is 15 nm to 150 nm. Optionally, the thickness of the second high refractive index film layer 240 is 15 nm to 100 nm. Further, the thickness of the second high refractive index film layer 240 is 15 nm to 60 nm, such as 15 nm, 20 nm, 25 nm, 30 nm, 31 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm or 60 nm, including all ranges and sub-ranges therebetween.

[0045] In some specific examples, the thickness of the third low refractive index film layer 250 is 10 nm to 40 nm. Optionally, the thickness of the third low refractive index film layer 250 is 15 nm to 35 nm. Further, the thickness of the third low refractive index film layer 250 is 10 nm to 30 nm, such as 10 nm, 13 nm, 15 nm, 18 nm, 21 nm, 22 nm, 25 nm, 28 nm or 30 nm, including all ranges and sub-ranges therebetween.

[0046] In some specific examples, the thickness of the third high refractive index film layer 260 is 500 nm to 2000 nm. Optionally, the thickness of the third high refractive index film layer 260 is 500 nm to 1500 nm. Further, the thickness of the third high refractive index film layer 260 is 500 nm to 1000 nm, such as 500 nm, 581 nm, 650 nm, 700 nm, 750 nm, 800 nm, 850 nm, 900 nm, 949 nm or 1000 nm, including all ranges and sub-ranges therebetween.

[0047] In some specific examples, the thickness of the fourth low refractive index film layer 270 is 70 nm to 100 nm. Optionally, the thickness of the fourth low refractive index film layer 270 is 75 nm to 95 nm. Further, the thickness of the fourth low refractive index film layer 270 is 80 nm to 90 nm, such as 80 nm, 81 nm, 82 nm, 83 nm, 84 nm, 85 nm, 86 nm, 87 nm, 88 nm, 89 nm or 90 nm, including all ranges and sub-ranges therebetween.

[0048] Optionally, an anti-fingerprint layer 300 is further provided on the fourth low refractive index film layer 270 of the anti-reflection film 200. In some specific examples, the anti-fingerprint layer 300 is an AF anti-fingerprint layer, and its thickness is 5 nm to 30 nm, such as 5 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, 20 nm, 23 nm, 25 nm or 30 nm, including all ranges and sub-ranges therebetween.

[0049] In some specific examples, the anti-reflection film 200 should exhibit an increasing nano-hardness as the thickness of the third high refractive index film layer 260 increases. Further, the nano-hardness of the substrate 100 should be less than that of the anti-reflection optical article 10.

[0050] In some specific examples, the material of the substrate 100 can be glass, sapphire glass, quartz, PMMA resin, etc.; among them, the glass can be soda-lime glass, aluminosilicate glass, borosilicate glass, etc. Those skilled in the art can select a suitable substrate according to the specific application field of the anti-reflection optical article 10.

[0051] Materials suitable for use as the high refractive index film layer include: zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), tantalum oxide (Ta 2 O 5 ), niobium oxide (NbO 2 ), hafnium oxide (HfO 2 ), or silicon nitride (Si 3 N 4 ). Materials suitable for use as the low refractive index film layer include: silicon dioxide (SiO 2 ). It should be understood that the chemical formulas corresponding to the above compounds are only common identifiers for those skilled in the art, but do not represent that the stoichiometric ratios of the atoms therein strictly conform to the subscript numbers. For example, in the process of specifically preparing the silicon nitride layer, it may be affected by the specific preparation process, resulting in certain lattice defects, and the obtained silicon nitride is actually SiN x (x≠3 / 4), but this does not exceed the scope of the above compounds.

[0052] In some more specific examples, the materials of the first low refractive index film layer 210, the second low refractive index film layer 230, the third low refractive index film layer 250, and the fourth low refractive index film layer 270 are all silicon dioxide; the materials of the first high refractive index film layer 220, the second high refractive index film layer 240, and the third high refractive index film layer 260 are all silicon nitride. Among them, silicon nitride has a relatively high nano-hardness. Using silicon nitride as the material of the third high refractive index film layer 260 and designing the anti-reflection film 200 to significantly increase the thickness of the third high refractive index film layer 260 can effectively improve the nano-hardness of the anti-reflection film 200.

[0053] In some specific examples, during the deposition of the above-mentioned low-refractive-index film layers and high-refractive-index film layers, inductively coupled plasma-assisted magnetron sputtering is used, and at the same time, an anode layer linear ion source is used to assist linear ion beam bombardment to increase the overall nano-hardness of the antireflection film 200. Further, the substrate 100 is a substrate that has been pre-cleaned by an anode layer linear ion source to enhance the adhesion between the antireflection film 200 and the substrate 100.

[0054] On the other hand, a method for preparing an antireflection optical article. It includes the following steps:

[0055] Use an anode layer linear ion source to clean the surface of the substrate, and sequentially deposit the film layers of the antireflection film. The antireflection film includes alternately stacked low-refractive-index film layers and high-refractive-index film layers, and both the bottom film layer and the top film layer of the antireflection film are low-refractive-index film layers; the high-refractive-index film layer disposed under the top film layer is a silicon nitride film layer;

[0056] The method for depositing each film layer is inductively coupled plasma-assisted magnetron sputtering, and an anode layer linear ion source is used to assist linear ion beam bombardment during magnetron sputtering; control the deposition time so that the thickness of the silicon nitride film layer is 500 nm to 2000 nm.

[0057] It can be understood that magnetron sputtering is a commonly used method for preparing thin films. Magnetron sputtering introduces a magnetic field on the surface of the target cathode and uses the magnetic field to constrain charged particles to increase the plasma density to increase the sputtering rate. Inductively coupled plasma-assisted magnetron sputtering refers to generating secondary plasma (ICP) through an inductively coupled coil placed between the target and the substrate, which can greatly increase the ionization rate and plasma density. Depositing with inductively coupled plasma-assisted magnetron sputtering has a wide working pressure range, a high dissociation rate, and high-concentration reactive ions and free radicals can fully combine the film layer, with small film layer absorption and fast deposition rate, which can significantly improve the density and hardness of the film layer.

[0058] When depositing each film layer, it also includes bombarding the substrate and the film layer deposited on the surface of the substrate with an anode layer linear ion source. The further increased auxiliary linear ion beam bombardment can remove the adsorbed gas on the surface of the film layer and the loosely bound atoms on the surface during deposition, compact the film layer, eliminate the film layer stress, greatly enhance the bonding force between the film layers, improve the density and nano-hardness of the film layer, and improve its wear resistance and scratch resistance.

[0059] Please refer to Figure 2 , in some specific examples, it is the following steps.

[0060] Step S100, use an anode layer linear ion source (LP) to clean the surface of the substrate.

[0061] In some specific examples, before step S100, it also includes pre-cleaning the substrate to remove dust, oil stains and other residual foreign matters on the surface of the substrate.

[0062] In some specific examples, before step S100, it also includes placing the substrate in a vacuum chamber for vacuum pumping and preheating steps. More specifically, the vacuum pressure ≤ 5×10 -3 Pa, and the preheating temperature is 120°C to 150°C. Optionally, the preheating temperature is 130°C.

[0063] In some specific examples, during the linear ion cleaning process, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 600 V to 2000 V, and the time is 3 min to 10 min. The linear ion cleaning process is completed in a protective atmosphere. The protective gas can be argon, nitrogen or other inert gases. The protective gas is a flowing gas, and the gas flow rate is 30 sccm to 100 sccm.

[0064] The ion beam emitted from the linear ion source bombards the surface of the substrate, which can not only remove the contaminants on the surface of the substrate, but also form an atomic mixing zone at the substrate - antireflection film layer interface, improving the film - substrate bonding strength and adhesion.

[0065] Step S200, depositing each low - refractive - index film layer and high - refractive - index film layer.

[0066] Specifically, inductively coupled plasma (ICP) - assisted magnetron sputtering is used to deposit each low - refractive - index film layer and high - refractive - index film layer, and at the same time, an anode layer linear ion source is used for auxiliary linear ion beam bombardment.

[0067] In some specific examples, the magnetron sputtering is selected from pulsed DC magnetron sputtering, medium - frequency magnetron sputtering, radio - frequency sputtering or high - power pulsed magnetron sputtering. Optionally, the magnetron sputtering is pulsed DC magnetron sputtering. For the pulsed DC magnetron sputtering technology, the arc response speed is fast, which can effectively suppress the discharge arc caused by the charge accumulation on the target surface or the film layer surface, effectively avoid the damage defects of the film layer caused by arc discharge, thereby further improving the quality of the film layer and improving its wear - resistance and scratch - resistance performance.

[0068] In some specific examples, the material of the low refractive index film layer is silicon dioxide, the magnetron sputtering target is a silicon target, and the reaction gas is oxygen. More specifically, the process for depositing the low refractive index film layer is as follows: the oxygen flow rate is 100 sccm to 300 sccm, the silicon target power is 3 kW to 12 kW, the inductively coupled plasma source power is 2 kW to 5 kW, the anode layer linear ion source current is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film forming temperature is 150 °C to 300 °C. Control an appropriate deposition time to obtain the thickness of each required low refractive index film layer. The thickness of each low refractive index film layer can refer to the thickness of each low refractive index film layer in the above antireflection optical article 10.

[0069] In some specific examples, the material of the high refractive index film layer is silicon nitride, the magnetron sputtering target is a silicon target, and the reaction gas is nitrogen. More specifically, the process for depositing the high refractive index film layer is as follows: the nitrogen flow rate is 100 sccm to 300 sccm, the silicon target power is 3 kW to 12 kW, the inductively coupled plasma source power is 2 kW to 5 kW, the anode layer linear ion source current is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film forming temperature is 150 °C to 300 °C. Control an appropriate deposition time to obtain the thickness of each required high refractive index film layer. The thickness of each low refractive index film layer can refer to the thickness of each low refractive index film layer in the above antireflection optical article 10.

[0070] Step S300, prepare an anti-fingerprint layer.

[0071] In some specific examples, the anti-fingerprint layer is an AF anti-fingerprint layer. The way to prepare the AF anti-fingerprint layer is evaporation coating, and adjust the film forming time to the target film thickness.

[0072] The above antireflection optical article designs the high refractive index film layer under the top film layer as a silicon nitride layer and greatly increases its thickness to effectively improve the nano-hardness of the antireflection optical article. The antireflection optical article exhibits excellent nano-hardness and wear resistance. The side including the antireflection film exhibits a nano-hardness of more than 11 GPa and can pass a linear abrasion test of more than 2000 cycles. And, since the antireflection optical article does not add a wear-resistant layer but increases the thickness of the silicon nitride film layer, the high refractive index film layer also has the function of improving nano-hardness. Therefore, the surface nano-hardness and wear resistance of the article can be improved without adding a wear-resistant layer, which is equivalent to simplifying the preparation process. At the same time, the silicon nitride film layer has a variable thickness of 500 nm to 2000 nm, and can be correspondingly selected and designed to improve the nano-hardness of the optical article.

[0073] Furthermore, the above antireflection optical article can also be applied to display screens, camera lenses or window glasses.

[0074] According to one embodiment, a display screen includes a protective cover plate and a display screen functional body, and the protective cover plate covers the surface of the display screen functional body. The protective cover plate is the antireflection optical article provided in the above embodiment, or the antireflection optical article prepared by the preparation method of the antireflection optical article provided in the above embodiment.

[0075] According to another embodiment, a camera lens is the antireflection optical article provided in the above embodiment, or the antireflection optical article prepared by the preparation method of the antireflection optical article provided in the above embodiment.

[0076] According to still another embodiment, a window glass can be, for example, a vehicle window glass or a door and window glass, etc. The window glass is the antireflection optical article provided in the above embodiment, or the antireflection optical article prepared by the preparation method of the antireflection optical article provided in the above embodiment.

[0077] To make the present invention easier to understand and implement, the following also provides relatively easy-to-implement and more specific and detailed test examples and comparative examples for reference. Through the description and performance results of the following specific test examples and comparative examples, the embodiments of the present invention and their advantages will also be obvious.

[0078] Unless otherwise specified, the raw materials used in the following test examples can be conventionally purchased from the market.

[0079] In addition, during the actual preparation process, the thickness of each film layer is prepared by adjusting specific parameters of the preparation process, so its actual thickness may deviate slightly from the expected thickness, but it does not affect the progress of each comparative example and test example.

[0080] The base materials of each test example and each comparative example are selected as aluminosilicate glass.

[0081] Test Example 1

[0082] The glass substrate is pre-cleaned to remove dust, oil stains and other residual foreign matters on the substrate surface.

[0083] The qualified substrate after inspection and cleaning is placed in a vacuum chamber for evacuation and preheating, and the vacuum pressure ≤ 5.0×10 - 3 Pa, and the preheating temperature is 130 °C.

[0084] Linear ion cleaning treatment is carried out using an anode layer linear ion source, flowing argon gas is introduced, the flow rate is 100 sccm, the current is 600 mA, the voltage is 1000 V, and the cleaning time is 10 min to activate the surface of the substrate.

[0085] Deposit the first low-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing oxygen gas are introduced. The argon gas flow rate is 300 sccm, the oxygen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited first low-refractive-index film layer is about 50 nm.

[0086] Deposit the first high-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing nitrogen gas are introduced. The argon gas flow rate is 300 sccm, the nitrogen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited first high-refractive-index film layer is about 11 nm.

[0087] Deposit the second low-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing oxygen gas are introduced. The argon gas flow rate is 300 sccm, the oxygen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited second low-refractive-index film layer is about 55 nm.

[0088] Deposit the second high-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing nitrogen gas are introduced. The argon gas flow rate is 300 sccm, the nitrogen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited second high-refractive-index film layer is about 31 nm.

[0089] Deposit the third low-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing oxygen gas are introduced. The argon gas flow rate is 300 sccm, the oxygen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited third low-refractive-index film layer is about 21 nm.

[0090] Deposit the third high-refractive-index film layer. The Si target is connected to a pulsed DC power supply, and flowing argon gas and flowing nitrogen gas are introduced. The argon gas flow rate is 300 sccm, the nitrogen gas flow rate is 300 sccm, the Si target power is 10 kW, the inductively coupled plasma source power is 5 kW, the current of the anode layer linear ion source is 600 mA, and the voltage is 500 V. The thickness of the deposited third high-refractive-index film layer is about 581 nm.

[0091] Deposit the fourth low refractive index film layer. Connect the Si target to a pulsed DC power supply, introduce flowing argon gas and flowing oxygen gas. The argon gas flow rate is 300 sccm, the oxygen gas flow rate is 300 sccm, the power of the Si target is 10 kW, the power of the inductively coupled plasma source is 5 kW, the current of the anode layer linear ion source is 600 mA, the voltage is 500 V, and the thickness of the deposited fourth low refractive index film layer is about 86 nm.

[0092] Form an AF fingerprint-proof layer on the fourth low refractive index film layer by evaporation. The thickness of the AF fingerprint-proof layer is about 10 nm.

[0093] The thickness parameters of each layer in Test Example 1 are as follows:

[0094] The thickness of the first low refractive index film layer is about 50 nm;

[0095] The thickness of the first high refractive index film layer is about 11 nm;

[0096] The thickness of the second low refractive index film layer is about 55 nm;

[0097] The thickness of the second high refractive index film layer is about 31 nm;

[0098] The thickness of the third low refractive index film layer is about 21 nm;

[0099] The thickness of the third high refractive index film layer is about 581 nm;

[0100] The thickness of the fourth low refractive index film layer is about 86 nm;

[0101] The thickness of the AF fingerprint-proof layer is about 10 nm.

[0102] Test Example 2

[0103] The difference between this test example and Test Example 1 is that the thickness of each layer is slightly different, and the rest of the preparation processes are basically the same. The thickness parameters of each layer in Test Example 2 are as follows:

[0104] The thickness of the first low refractive index film layer is about 65 nm;

[0105] The thickness of the first high refractive index film layer is about 10 nm;

[0106] The thickness of the second low refractive index film layer is about 59 nm;

[0107] The thickness of the second high refractive index film layer is about 30 nm;

[0108] The thickness of the third low refractive index film layer is about 22 nm;

[0109] The thickness of the third high refractive index film layer is about 949 nm;

[0110] The thickness of the fourth low refractive index film layer is about 86 nm;

[0111] The thickness of the AF fingerprint-proof layer is about 20 nm.

[0112] Test Example 3

[0113] The difference between this test example and Test Example 1 is that the thickness of each layer is slightly different, and the remaining preparation processes are basically the same. The thickness parameters of each layer in Test Example 3 are as follows:

[0114] The thickness of the first low-refractive-index film layer is about 20 nm;

[0115] The thickness of the first high-refractive-index film layer is about 21 nm;

[0116] The thickness of the second low-refractive-index film layer is about 27 nm;

[0117] The thickness of the second high-refractive-index film layer is about 46 nm;

[0118] The thickness of the third low-refractive-index film layer is about 5 nm;

[0119] The thickness of the third high-refractive-index film layer is about 510 nm;

[0120] The thickness of the fourth low-refractive-index film layer is about 86 nm;

[0121] The thickness of the AF fingerprint-proof layer is about 10 nm.

[0122] Test Example 4

[0123] The difference between this test example and Test Example 1 is that the thickness of each layer is slightly different, and the remaining preparation processes are basically the same. The thickness parameters of each layer in Test Example 4 are as follows:

[0124] The thickness of the first low-refractive-index film layer is about 108 nm;

[0125] The thickness of the first high-refractive-index film layer is about 8 nm;

[0126] The thickness of the second low-refractive-index film layer is about 57 nm;

[0127] The thickness of the second high-refractive-index film layer is about 27 nm;

[0128] The thickness of the third low-refractive-index film layer is about 23 nm;

[0129] The thickness of the third high-refractive-index film layer is about 2000 nm;

[0130] The thickness of the fourth low-refractive-index film layer is about 86 nm;

[0131] The thickness of the AF fingerprint-proof layer is about 10 nm.

[0132] Comparative Example 1

[0133] The thickness of each layer and the preparation process of Comparative Example 1 are basically the same as those of Test Example 1. The main difference is that when preparing each film layer, an anode layer linear ion source is not used for auxiliary bombardment.

[0134] Comparative Example 2

[0135] The preparation process of each layer of Comparative Example 2 is basically the same as those of Test Example 1 and Test Example 2. The main difference is that when preparing each film layer, an anode layer linear ion source is not used for auxiliary bombardment, and the thickness of the third high refractive index film layer is only 50 nm. The thickness parameters of each layer of Comparative Example 2 are as follows:

[0136] The thickness of the first low refractive index film layer is about 30 nm;

[0137] The thickness of the first high refractive index film layer is about 15 nm;

[0138] The thickness of the second low refractive index film layer is about 46 nm;

[0139] The thickness of the second high refractive index film layer is about 48 nm;

[0140] The thickness of the third low refractive index film layer is about 20 nm;

[0141] The thickness of the third high refractive index film layer is about 50 nm;

[0142] The thickness of the fourth low refractive index film layer is about 97 nm;

[0143] The thickness of the AF fingerprint-proof layer is about 10 nm.

[0144] Comparative Example 3

[0145] The preparation process of each layer of Comparative Example 3 is basically the same as those of Test Example 1 and Test Example 2. The main difference is that the thickness of the third high refractive index film layer is only 50 nm. The thickness parameters of each layer of Comparative Example 3 are as follows:

[0146] The thickness of the first low refractive index film layer is about 30 nm;

[0147] The thickness of the first high refractive index film layer is about 15 nm;

[0148] The thickness of the second low refractive index film layer is about 46 nm;

[0149] The thickness of the second high refractive index film layer is about 48 nm;

[0150] The thickness of the third low refractive index film layer is about 20 nm;

[0151] The thickness of the third high refractive index film layer is about 50 nm;

[0152] The thickness of the fourth low refractive index film layer is about 97 nm;

[0153] The thickness of the AF fingerprint-proof layer is about 10 nm.

[0154] Comparative Example 4

[0155] Blank aluminosilicate glass without deposited antireflection film.

[0156] The nano-hardness, linear abrasion test results, and light transmittance test results of the above test examples and comparative examples can be seen in Table 1.

[0157] The hardness test uses the methods specified in GB / T 22458 and ASTM E 2546-07 standards. The nano-hardness is measured by an Anton-Paar NHT 3 nano-indentation tester. As used herein, the nano-hardness test includes indenting the material surface with a diamond Berkovich nano-hardness tester indenter, and using a method based on load-depth data to determine nano-hardness and material parameters to measure the nano-hardness of the film layer. The test load is 2 mN, the load loading and unloading rate is 4 mN / min, and the indentation depth is in the range of about 50 - 200 nm.

[0158] "Linear abrasion test" refers to a test method using a Taber 5750 linear abrasion tester and accessories provided by Taber Company, in an environment with a temperature of about 22°C ± 3°C and a relative humidity of not more than about 70%, a load of 500 g, a cycle rate of 40 times / min, a steel wool model of Bonstar#0000, and a steel wool friction area of 20 mm * 20 mm, which complies with the content specified in ASTM D1044-99 standard.

[0159] Table 1

[0160]

[0161]

[0162] The light transmittance spectra of Test Example 1 and Comparative Example 5 can be seen in Figure 3 , and it can be seen that the antireflection optical article obtained in Test Example 1 has a light transmittance of more than 94% in a wide wavelength range of 400 nm to 700 nm.

[0163] The light transmittance spectra of Test Example 2 and Comparative Example 5 can be seen in Figure 4 , and it can be seen that the antireflection optical article obtained in Test Example 1 has a light transmittance of more than 94% in the wavelength range of 400 nm to 700 nm.

[0164] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0165] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. An antireflection optical article, characterized in that, it comprises a substrate and an antireflection film disposed on at least one surface of the substrate, the antireflection film comprising alternately stacked low refractive index film layers and high refractive index film layers, the refractive index of the low refractive index film layers being lower than that of the high refractive index film layers; the bottom film layer and the top film layer of the antireflection film are both the low refractive index film layers; the high refractive index film layer disposed under the top film layer is a silicon nitride film layer with a thickness of 500 nm to 2000 nm; the antireflection film has a nano-hardness of 11 GPa or more, and the average light transmittance of the antireflection optical article in the wavelength range of 400 nm to 700 nm is above 94%; the antireflection film comprises a first low refractive index film layer with a thickness of 10 nm to 90 nm, a first high refractive index film layer with a thickness of 5 nm to 30 nm disposed on the first low refractive index film layer, a second low refractive index film layer with a thickness of 20 nm to 70 nm disposed on the first high refractive index film layer, a second high refractive index film layer with a thickness of 15 nm to 150 nm disposed on the second low refractive index film layer, a third low refractive index film layer with a thickness of 10 nm to 40 nm disposed on the second high refractive index film layer, a third high refractive index film layer with a thickness of 500 nm to 2000 nm disposed on the third low refractive index film layer, and a fourth low refractive index film layer with a thickness of 70 nm to 100 nm disposed on the third high refractive index film layer; the first low refractive index film layer is the bottom film layer, and the fourth low refractive index film layer is the top film layer.

2. The antireflection optical article according to claim 1, characterized in that, the antireflection film further comprises an anti-fingerprint layer, and the anti-fingerprint layer is disposed on the top film layer.

3. The antireflection optical article according to any one of claims 1 to 2, characterized in that, the antireflection film can pass a linear abrasion test of more than 2000 cycles.

4. The antireflection optical article according to any one of claims 1 to 2, characterized in that, the low refractive index film layers are all silica film layers.

5. The antireflection optical article according to any one of claims 1 to 2, characterized in that, the materials of the first high refractive index film layer and the second high refractive index film layer are independently selected from zirconia film layer, titanium oxide film layer, tantalum oxide film layer, niobium oxide film layer, hafnium oxide film layer or silicon nitride film layer respectively.

6. The antireflection optical article according to any one of claims 1 to 2, characterized in that, the low refractive index film layers are all silica film layers, and the high refractive index film layers are all silicon nitride film layers.

7. The antireflection optical article according to any one of claims 1 to 2, characterized in that, the preparation method of the antireflection film comprises the following steps: depositing each film layer of the antireflection film on the surface of the substrate in sequence, the antireflection film comprising alternately stacked low refractive index film layers and high refractive index film layers, and the bottom film layer and the top film layer of the antireflection film are both the low refractive index film layers; the high refractive index film layer disposed under the top film layer is a silicon nitride film layer; The method for depositing each film layer is inductively coupled plasma-assisted magnetron sputtering, and an anode layer linear ion source is used for auxiliary linear ion beam bombardment while magnetron sputtering; the deposition time is controlled so that the thickness of the silicon nitride film layer is 500 nm to 2000 nm.

8. The antireflection optical article according to claim 7, wherein, before depositing each film layer of the antireflection film, it further includes a step of pre-treating the surface of the substrate with an anode layer linear ion source.

9. The antireflection optical article according to claim 8, wherein, during the pre-treatment, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 600 V to 2000 V, and the time is 3 min to 10 min.

10. The antireflection optical article according to any one of claims 8 to 9, wherein, the low refractive index film layer is a silicon dioxide film layer, and the process for depositing the low refractive index film layer is as follows: the oxygen flow rate is 100 sccm to 300 sccm, the power of the silicon target is 3 kW to 12 kW, the power of the inductively coupled plasma source is 2 kW to 5 kW, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film forming temperature is 150 °C to 300 °C.

11. The antireflection optical article according to any one of claims 8 to 9, wherein, the high refractive index film layer is a silicon nitride film layer, and the process for depositing the high refractive index film layer is as follows: the nitrogen flow rate is 100 sccm to 300 sccm, the power of the silicon target is 3 kW to 12 kW, the power of the inductively coupled plasma source is 2 kW to 5 kW, the current of the anode layer linear ion source is 300 mA to 600 mA, the voltage is 100 V to 600 V, and the film forming temperature is 150 °C to 300 °C.

12. The application of an antireflection optical article in the preparation of a display screen, a camera lens or a window glass, wherein the antireflection optical article is the antireflection optical article according to any one of claims 1 to 11.

13. A display screen, a camera lens or a window glass, wherein, the display screen includes a protective cover plate and a display screen functional body, the protective cover plate covers the surface of the display screen functional body, and the protective cover plate is the antireflection optical article or is processed from the antireflection optical article; the camera lens is the antireflection optical article or is processed from the antireflection optical article; the window glass is the antireflection optical article or is processed from the antireflection optical article; wherein: the antireflection optical article is the antireflection optical article according to any one of claims 1 to 11.

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