Optical antireflection film, vehicle window glass, and vehicle

Abstract

This invention discloses an optical antireflective film, a car window glass, and a vehicle. The optical antireflective film includes an antireflective dielectric film and a moth-eye film; the antireflective dielectric film includes n high-refractive-index layers and n-1 low-refractive-index layers, the high-refractive-index layers and low-refractive-index layers are staggered and stacked, and the two outermost layers are both high-refractive-index layers; the moth-eye film is disposed on the outer surface of one of the outermost high-refractive-index layers. This invention combines the antireflective dielectric film and the moth-eye film, and uses the structural support layer of the moth-eye film as the outermost low-refractive-index layer of the dielectric antireflective film for a unified optical refractive index design, which not only ensures the antireflective effect of the dielectric antireflective film, but also gives its outer surface anti-fogging, hydrophobic, and fingerprint-resistant effects.

Description

Technical Field

[0001] This invention relates to the field of glass, specifically to an optical antireflective film, automotive window glass, and vehicles. Background Technology

[0002] Currently, automotive LiDAR (Light Detection and Ranging) applications are generally external, mounted on the roof of the vehicle; however, external LiDAR solutions have disadvantages such as large size and weight, susceptibility to adverse weather conditions such as rain and snow, impact from gravel, high wind resistance, and difficulty in defogging and defrosting. Based on these shortcomings, the trend is towards internally mounted LiDAR systems (internal placement means placing the LiDAR inside the windshield, i.e., inside the vehicle).

[0003] In LiDAR technology, the windshield affects the signal strength received by the built-in LiDAR. Fogging prevention in the signal window area is a crucial condition for ensuring the vehicle's autonomous driving capabilities in real-world driving conditions. Currently, most mid-to-high-end vehicles have windshields with wire-reinforced heating or silver-plated heating for defrosting and defogging; however, the wires in the glass are usually tungsten wires, which may obstruct or even block the LiDAR signal to some extent; silver-plated heating further attenuates the LiDAR signal due to the high reflectivity of silver.

[0004] How to both enhance the transmission of near-infrared signals (typically 905nm or 1550nm) in the signal window area of ​​the windshield and provide anti-fog functionality in the same area is a crucial technical challenge that needs to be overcome in the development of future autonomous vehicles (or advanced driver assistance systems). Summary of the Invention

[0005] One object of the present invention is to provide an optical antireflective film that also has anti-fogging, hydrophobic, and anti-fingerprint functions.

[0006] Another objective of this invention is to provide a vehicle window glass, wherein the surface of the signal window area is provided with an optical anti-reflective film provided by this invention, which also has functions such as anti-fogging, specifically a windshield.

[0007] Another object of the present invention is to provide a vehicle including a window glass having the aforementioned optical anti-reflective film of the present invention, which also has functions such as anti-fogging.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In one aspect, the present invention provides an optical antireflective film, comprising an antireflective medium film and a moth-eye film;

[0010] The antireflective medium film includes n high refractive index layers and n-1 low refractive index layers, which are stacked alternately, with both outermost layers being high refractive index layers; the moth-eye film is disposed on the outer surface of one of the outermost high refractive index layers.

[0011] When the optical antireflective film provided by this invention is applied to glass, the moth-eye film is located on the side away from the glass surface; that is, starting from the glass surface, the layers are in sequence: high refractive index layer, low refractive index layer, high refractive index layer, low refractive index layer, ... high refractive index layer, moth-eye film.

[0012] According to the optical antireflective film of the present invention, preferably, the moth-eye film includes a structural support layer and a moth-eye structural layer; the structural support layer is in direct contact with the outermost high refractive index layer of the antireflective medium film. That is, there is no adhesive layer between the moth-eye film and the antireflective medium film.

[0013] In the optical antireflective film of the present invention, the moth-eye film has superhydrophobic properties, with a water contact angle of 150° to 165°, thus providing an anti-fogging effect. Furthermore, the moth-eye structure of the film has a period length in the range of 100nm to 200nm; the smaller the period, the larger the water contact angle, and the better the hydrophobicity (superhydrophobic surfaces generally refer to surfaces with a water contact angle greater than 150°), resulting in a better anti-fogging effect. This superhydrophobicity is caused by surface modification of the moth-eye structure: a surface morphology with a certain roughness allows water droplets to suspend above the protrusions on the solid surface, reducing the actual contact area between the water droplets and the solid surface, thereby reducing the adhesion between water and the solid surface and increasing the surface hydrophobicity. Due to the superhydrophobicity of the moth-eye film, water droplets easily roll off at tilt angles. When the optical antireflective film of the present invention is applied to the windshield, its installation angle is generally between 18° and 32°, thus the moth-eye film has anti-fogging, hydrophobic, and fingerprint-resistant effects.

[0014] Furthermore, the moth-eye membrane also possesses optical surface anti-reflection effects; the moth-eye structure is equivalent to being composed of multiple layers of anti-reflection films with varying refractive indices, which can reduce Fresnel reflection on the material surface and achieve low reflectivity over a wide spectral range. In the membrane structure design of the antireflective medium, the moth-eye membrane is located outside the outermost high-refractive-index layer of the antireflective medium, and its structural support layer acts as a low-refractive-index layer. A unified optical simulation design for both the antireflective medium and the moth-eye membrane ensures the accuracy of the refracted light deflection design, thereby enhancing its antireflection effect on near-infrared signals (typically 905nm or 1550nm).

[0015] According to the optical antireflective film of the present invention, preferably, the refractive index of the structural support layer of the moth-eye film is 1.50 to 1.60.

[0016] According to the optical antireflective film of the present invention, the total number of layers of the antireflective medium film is an odd number (2n-1), and preferably greater than or equal to 7, and generally does not exceed 21 layers. That is, preferably, 7≤2n-1≤21.

[0017] According to the optical antireflective film of the present invention, preferably, the total thickness of the antireflective medium film is 200nm to 2500nm; more preferably, it is 200nm to 1000nm.

[0018] According to the optical antireflective coating of the present invention, preferably, the refractive index of the high refractive index layer is 1.6 to 3.5; and the refractive index of the low refractive index layer is 1.2 to 1.6.

[0019] According to the optical antireflective coating of the present invention, preferably, the material of the high refractive index layer is selected from Si and FeO. x NbO x SiN x ZrO x TiO x TiN x MoO x TaO x At least one of the following; the material of the low refractive index layer is selected from SiO2. x MgF x AlO x AlSiO x At least one of them.

[0020] The antireflective coating can be applied by magnetron sputtering physical deposition. The equipment can be a continuous vertical coating machine or a horizontal coating machine, with a continuous vertical coating machine being preferred.

[0021] According to the optical antireflective film of the present invention, preferably, the material of the moth-eye film is an ultraviolet-curable resin, comprising 80-97 parts by weight of a main resin, 2-4 parts by weight of a coupling agent and 1-2.5 parts by weight of a photoinitiator;

[0022] The main resin includes, but is not limited to, at least one of epoxy acrylate, polyurethane acrylate, polyester acrylate, polyether acrylate, amino acrylate, and acrylate; the coupling agent is selected from, but is not limited to, at least one of silane coupling agents, titanate coupling agents, aluminate coupling agents, and metal composite coupling agents; the photoinitiator is selected from, but is not limited to, at least one of common 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzoin and its derivatives, benzoyl derivatives, dialkoxyacetophenone, α-hydroxyalkyl benzophenone, benzophenone and its derivatives, vinyl sulfide compounds, diazonium salts, diaryliodomonium salts, triarylthionium salts, alkylthionium salts, and iron aromatic salts.

[0023] The unique feature of the moth-eye membrane described in this invention is the addition of a certain amount of coupling agent to its material to increase the adhesion between the moth-eye membrane and the antireflective medium membrane, eliminating the need for an adhesive layer. The specific coupling agent is selected based on the material of the outermost high-refractive-index layer of the antireflective medium membrane; for example, in actual production processes, Si and SiN are commonly used to fabricate high-refractive-index layers, in which case a silane coupling agent is selected accordingly.

[0024] As will be understood by those skilled in the art, the amount of photoinitiator added is sufficient to initiate ultraviolet curing; preferably, in the total material formulation of the moth eye film, the amount of photoinitiator added is 1 to 2.5 parts by weight.

[0025] According to the optical antireflective film of the present invention, preferably, the moth-eye film is prepared by a nano-transfer process to transfer the moth-eye structure onto a UV-curable resin; specifically, the moth-eye microstructure can be fabricated using porous alumina (AAO) as a template.

[0026] According to the optical antireflective film of the present invention, preferably, the period length of the moth-eye structure is 100nm to 200nm, the linewidth of the structure is 50nm to 100nm, and the height is 400nm to 1000nm.

[0027] According to the optical antireflective film of the present invention, preferably, the total thickness of the moth-eye film is 500nm to 1500nm, and the thickness of the structural support layer is 1 / 4 to 1 / 2 of the thickness of the moth-eye structural layer, more preferably 1 / 3.

[0028] Another aspect of the present invention provides a vehicle window glass having the aforementioned optical anti-reflective coating disposed on its surface.

[0029] The preferred type of vehicle window glass is the windshield, which can be used to embed an onboard LiDAR. The optical antireflective film provided above is set in the signal window area, thereby enabling the signal window area to simultaneously have the functions of enhancing the transmission of signals within a specific wavelength range, as well as anti-fogging, surface hydrophobicity, and anti-fingerprint properties.

[0030] According to the present invention, the vehicle window glass preferably includes laminated glass, which includes an outer glass panel, an intermediate layer and an inner glass panel;

[0031] The intermediate layer is sandwiched between the outer glass plate and the inner glass plate. The outer glass plate has a first surface and a second surface facing each other, with the second surface facing the intermediate layer. The inner glass plate has a third surface and a fourth surface facing each other, with the third surface facing the intermediate layer.

[0032] The laminated glass has a signal window area for the transmission of signals from an optical sensor; an optical antireflective film provided by the present invention is provided on the fourth surface of the inner glass plate, wherein the antireflective medium film and the moth-eye film are arranged sequentially in the direction away from the fourth surface; in the thickness direction of the laminated glass, the projection of the optical antireflective film on the signal window area covers the signal window area.

[0033] According to the present invention, preferably, the signal window region has a signal transmittance of ≥80% for wavelengths in the 900nm-950nm or 1500nm-1600nm range incident at an angle of 60°-67°. Compared to a window without the anti-fog and anti-reflective film described in the present invention, the signal transmittance in the 900nm-950nm or 1500nm-1600nm wavelength range incident at an angle of 60°-67° increases by 6%-10%. Specifically, the corresponding signal transmittance is achieved by selecting the appropriate optical anti-reflective film structure based on the working signal wavelength of LiDAR.

[0034] According to the present invention, the transmittance of the signal window area for signals in the wavelength range of 900nm to 950nm or 1500nm to 1600nm incident at an incident angle of 0° is preferably ≥88%.

[0035] In another aspect, the present invention provides a vehicle, including a vehicle body and a window glass provided above, the window glass being connected to the vehicle body.

[0036] The beneficial effects of this invention include:

[0037] 1) In the LiDAR signal window area of ​​the windshield, if only a moth-eye film is used, the anti-reflection capability at the installation angle is still insufficient to meet the requirements of LiDAR signal transmittance. On the other hand, a single anti-reflection medium film does not have the effect of surface anti-fogging. This invention combines the anti-reflection medium film and the moth-eye film, and uses the structural support layer of the moth-eye film as the outermost low refractive index layer of the medium anti-reflection film with a unified optical refractive index design. This ensures the anti-reflection effect of the medium anti-reflection film and also gives it anti-fogging, surface hydrophobic, and anti-fingerprint effects. Compared with a simple anti-reflection medium film, it adds the anti-reflection effect of the moth-eye structure, making the signal transmittance of the glass signal area higher.

[0038] 2) When only an antireflective coating is used, a large number of film layers are often required, which makes the coating process costly and slows down production. This invention addresses this by adding a "moth-eye" film to the outermost layer of the antireflective coating. Because the moth-eye film structure causes the refractive index of the material surface to change continuously along the depth direction, it reduces the reflection phenomenon caused by abrupt changes in refractive index. Therefore, a film system with fewer film layers is sufficient to achieve the required increase in transmittance for the corresponding wavelength band.

[0039] 3) Common moth-eye films often require an adhesive layer (usually OCA optical adhesive) to bond the film to the substrate. This adhesive layer typically exceeds 10 μm in thickness, which can negatively impact the antireflective effect of the antireflective medium. The moth-eye film in this invention is directly applied to the outermost layer of the antireflective medium using UV curing. Furthermore, the structural support layer of the moth-eye film is nanometer-thick, serving as the outermost low-refractive-index layer in the optical film system design, thus not affecting the antireflective and antireflective effects of the antireflective medium. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the optical antireflective film provided by the present invention.

[0041] Figure 2 This is a schematic diagram of the structure of the vehicle window glass provided by the present invention.

[0042] Figure 3 A schematic diagram of the structure of the moth-eye membrane in the optical antireflective film of this invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Antireflective coating; 11. High refractive index layer; 12. Low refractive index layer;

[0045] 2. Moth eye membrane, 21. Structural support layer, 22. Moth eye structural layer. Detailed Implementation

[0046] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0047] This invention combines an antireflective dielectric film and a moth-eye film to design an optical antireflective film. The structural support layer of the moth-eye film is used as the outermost low-refractive-index layer of the dielectric antireflective film, and the optical refractive index is uniformly designed. This not only ensures the antireflective effect of the dielectric antireflective film, but also gives its outer surface an anti-fogging effect. Moreover, compared with a simple antireflective dielectric film, the antireflective effect of the moth-eye structure is added, making it more transparent to near-infrared signals (generally 905nm or 1550nm).

[0048] like Figure 1As shown, the optical antireflective film provided by the present invention includes an antireflective medium film 1 and a moth-eye film 2. The antireflective medium film 1 includes n high-refractive-index layers 11 and n-1 low-refractive-index layers 12, which are staggered and stacked, with both outermost layers being high-refractive-index layers 11. The moth-eye film 2 is disposed on the outer surface of one of the outermost high-refractive-index layers 11. The total number of layers in the antireflective medium film 1 is an odd number (2n-1), preferably greater than or equal to 7, and generally does not exceed 21 layers. That is, preferably, 7≤2n-1≤21. The moth-eye film 2 includes a structural support layer 21 and a moth-eye structural layer 22, wherein the structural support layer 21 is in direct contact with the outermost high-refractive-index layer 11 of the antireflective medium film 1, without the need for an adhesive layer connection.

[0049] like Figure 2 As shown, when the optical antireflective film provided by the present invention is applied to glass, the moth-eye film 2 is located on the side away from the glass surface; that is, starting from the glass surface, the layers are in sequence: high refractive index layer 11, low refractive index layer 12, high refractive index layer 11, low refractive index layer 12, ... high refractive index layer 11, moth-eye film 2.

[0050] The moth-eye film 2 possesses superhydrophobic properties, with a water contact angle ranging from 150° to 165°, thus providing an anti-fogging effect. Furthermore, the moth-eye structure of the film 2 has a period length in the range of 100nm to 200nm; the smaller the period, the larger the water contact angle, resulting in better hydrophobicity (superhydrophobic surfaces generally refer to surfaces with a water contact angle greater than 150°), and thus better anti-fogging performance. This superhydrophobicity is caused by surface modification of the moth-eye structure: a surface morphology with a certain degree of roughness allows water droplets to suspend above the protrusions on the solid surface, reducing the actual contact area between the water droplets and the solid surface, thereby reducing the adhesion of water to the solid surface and increasing the surface hydrophobicity. Due to the superhydrophobicity of the moth-eye film, water droplets easily roll off at tilt angles. When the optical anti-reflective film of this invention is applied to the windshield, its installation angle is generally between 18° and 32°, thus the moth-eye film has anti-fogging, hydrophobic, and fingerprint-resistant effects.

[0051] Furthermore, the moth-eye membrane 2 also has the effect of optical surface anti-reflection; the moth-eye structure is equivalent to being composed of multiple layers of anti-reflection films with varying refractive indices, which can reduce Fresnel reflection on the material surface and obtain a low reflectivity over a wide spectral range. In the film structure design of the antireflection medium film 1, the moth-eye membrane 2 is located outside the outermost high refractive index layer of the antireflection medium film 1, and its structural support layer 21 acts as a low refractive index layer. By performing a unified optical simulation design on the antireflection medium film 1 and the moth-eye membrane 2, the design accuracy of the refracted light deflection can be guaranteed, thus enhancing its antireflection effect on near-infrared signals (generally 905nm or 1550nm).

[0052] like Figure 3 As shown, in a preferred embodiment of the present invention, the period length of the moth-eye structure in the moth-eye structure layer 22 is 100nm to 200nm, the linewidth of the structure is 50nm to 100nm, and the height H is 400nm to 1000nm.

[0053] Furthermore, the total thickness of the moth eye membrane is preferably 500 nm to 1500 nm, and the thickness of the structural support layer is preferably 1 / 4 to 1 / 2 of the thickness of the moth eye structural layer, more preferably 1 / 3.

[0054] Preferably, the refractive index of the structural support layer of the moth eye membrane is 1.50 to 1.60.

[0055] Preferably, the total thickness of the antireflective dielectric film 1 is 200 nm to 2500 nm; more preferably, it is 200 nm to 1000 nm. The refractive index of the high refractive index layer 11 is 1.6 to 3.5, and the material is preferably Si or FeO. x NbO x SiN x ZrO x TiO x TiN x MoO x TaO x At least one of the following, such as Si3N4; the refractive index of the low-refractive-index layer 12 is 1.2 to 1.6, and the material is preferably SiO2. x MgF x AlO x AlSiO x At least one of them, such as SiO2.

[0056] The antireflective coating 1 can be coated by magnetron sputtering physical deposition. The equipment can be a continuous vertical coating machine or a horizontal coating machine, preferably a continuous vertical coating machine.

[0057] The material of the moth eye membrane 2 is preferably a UV-curable resin, comprising 80-97 parts by weight of a main resin, 2-4 parts by weight of a coupling agent, and 1-2.5 parts by weight of a photoinitiator.

[0058] The main resin includes, but is not limited to, at least one of epoxy acrylate, polyurethane acrylate, polyester acrylate, polyether acrylate, amino acrylate, and acrylate.

[0059] The special feature of the moth-eye membrane described in this invention is that a certain amount of coupling agent is added to its material to increase the adhesion between the moth-eye membrane and the antireflective medium membrane. The coupling agent is selected from, but is not limited to, silane coupling agents, titanate coupling agents, aluminate coupling agents, metal composite coupling agents, etc. The specific selection of the coupling agent depends on the material of the outermost high refractive index layer of the antireflective medium membrane. For example, in actual production processes, Si, SiN, etc. are commonly used to make high refractive index layers, and silane coupling agents are selected accordingly.

[0060] The amount of photoinitiator added is sufficient to initiate ultraviolet curing; for example, in the total material formulation of the moth eye film 2, the mass fraction of the photoinitiator is preferably 1 to 2.5. Specifically, the photoinitiator is selected from, but not limited to, conventional ultraviolet photoinitiators, such as, but not limited to, at least one selected from, 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzoin and its derivatives, benzoyl derivatives, dialkoxyacetophenone, α-hydroxyalkyl phenyl ketone, benzophenone and its derivatives, vinyl sulfide compounds, diazonium salts, diaryliodomonium salts, triarylthionium salts, alkylthionium salts, and iron aromatic salts.

[0061] Common moth-eye films often require an adhesive layer (usually OCA optical adhesive) to bond the film to the substrate. This adhesive layer typically exceeds 10 μm in thickness, which can negatively impact the antireflective properties of the antireflective medium. The moth-eye film in this invention is directly applied to the outermost layer of the antireflective medium using UV curing. Furthermore, the structural support layer of the moth-eye film is nanometer-thick, serving as the outermost low-refractive-index layer in the optical film system design without affecting the antireflective properties of the antireflective medium itself.

[0062] Preferably, the moth-eye membrane is prepared using a nano-transfer process to transfer the moth-eye structure onto a UV-curable resin; specifically, the moth-eye microstructure can be fabricated using porous alumina (AAO) as a template. For example, an exemplary preparation process of the moth-eye membrane of the present invention includes: 1) coating a porous alumina (AAO) template onto a UV-curable resin (containing a coupling agent); 2) coating the template-coated UV-curable resin onto the surface of a substrate (specifically, the outermost high-refractive-index layer of an antireflective medium film); 3) irradiating the template-coated UV-curable resin with a UV lamp until it is completely cured onto the substrate; 4) removing the AAO template.

[0063] like Figure 2 As shown, the present invention also provides a vehicle window glass with an optical anti-reflective film designed above on its surface. The vehicle window glass is preferably a windshield, which can be used to house an in-vehicle LiDAR. The optical anti-reflective film provided above is applied to the signal window area, thereby enabling the signal window area to simultaneously possess both anti-reflective and anti-fog functions for signals within a specific wavelength range.

[0064] Preferably, the vehicle window glass comprises laminated glass, which includes an outer glass panel, an intermediate layer, and an inner glass panel; the intermediate layer is sandwiched between the outer glass panel and the inner glass panel; the outer glass panel has opposing first and second surfaces, with the second surface facing the intermediate layer; the inner glass panel has opposing third and fourth surfaces, with the third surface facing the intermediate layer. The laminated glass has a signal window area for signals from an optical sensor to pass through; an optical antireflective film provided by the present invention is provided on the fourth surface of the inner glass panel, with the antireflective medium film 1 and the moth-eye film 2 arranged sequentially in a direction away from the fourth surface; in the thickness direction of the laminated glass, the projection of the optical antireflective film onto the signal window area covers the signal window area.

[0065] Preferably, the signal window region has a signal transmittance of ≥80% for wavelengths of 900nm-950nm or 1500nm-1600nm at an incident angle of 60°-67°. Compared to car window glass without the anti-fog and anti-reflective film of the present invention, the signal transmittance for wavelengths of 900nm-950nm or 1500nm-1600nm at an incident angle of 60°-67° increases by 6%-10%.

[0066] Preferably, the signal window region has a transmittance of ≥88% for signals in the wavelength range of 900nm~950nm or 1500nm~1600nm incident at a 0° incident angle.

[0067] The present invention further provides a vehicle including a vehicle body and above-mentioned window glass, the window glass being connected to the vehicle body, thereby realizing the built-in vehicle-mounted LiDAR.

[0068] The present invention provides a set of embodiments to further illustrate the solution:

[0069] In the embodiments and comparative examples of the present invention, the antireflective dielectric film structure is based on cleaned sodium-calcium-silicon glass (or high-alumina glass, etc.), as shown in Table 1 as an example.

[0070] The antireflective coating consists of a stacked structure of six high- and low-refractive-index layers (D1-D6) from the glass surface upwards, plus an outermost high-refractive-index layer (H7 in D7), for a total of 13 layers, including seven Si3N4 high-refractive-index layers and six SiO2 low-refractive-index layers. In this series of embodiments and comparative examples, the outermost low-refractive-index layer in the film system design (i.e., L7 in D7), if L7 is SiO2 (refractive index 1.46), then the theoretical thickness of L7 (SiO2) is 268 nm; when L7 is set as the structural support layer of the moth-eye film (refractive index 1.55), the theoretical thickness of the structural support layer is 252 nm.

[0071] Table 1. Membrane structure of antireflective dielectric membranes

[0072]

[0073] This invention provides examples 1-9 and comparative examples 1-11 of an antireflection medium membrane structure for transmittance gain at 905nm (based on the signal wave of a specific laser LiDAR, commonly 905nm and 1550nm, with 905nm being the most common). The specific structural details, transmittance, and hydrophobicity are shown in Table 2.

[0074] The hydrophobic moth eye membrane 2 is made of UV-curable resin, comprising a main resin, a silane coupling agent, and a photoinitiator, with a total mass fraction of 100. Specifically, the main resin is polyurethane acrylate; the silane coupling agent is commercially available KH550 (γ-aminopropyltriethoxysilane), with mass fractions detailed in Table 2; the photoinitiator is 1.5% 2-hydroxy-2-methyl-1-phenyl-1-propanone; the remainder is the main resin. The moth eye membrane is prepared using a nano-transfer process to transfer the moth eye structure onto the UV-curable resin; the microstructure of the moth eye is fabricated using porous alumina (AAO) as a template, and the specific parameters of the moth eye structure are listed in Table 2.

[0075] Examples 1-9 are the optical antireflective coatings and automotive window glass designed according to the present invention. Comparative Example 1 is a blank windshield, i.e., the glass substrate used in Table 1. Comparative Example 2 is a pure antireflective dielectric film, i.e., fabricated on a glass substrate according to the film system structure in Table 1, and the outermost low refractive index layer (L7 in D7) is SiO2 with a thickness of 268nm. Comparative Example 3 is a pure moth-eye film, fabricated directly on a glass substrate according to the parameters listed in Table 2. Comparative Example 4 does not add a silane coupling agent to the material of the moth-eye film, but uses a 5μm OCA layer as an adhesive layer. Comparative Example 5 does not add a silane coupling agent to the material of the moth-eye film, nor does it have an adhesive layer. In Comparative Examples 6-11, the structural variables of the moth-eye film are changed.

[0076] Table 2 Examples 1-9 and Comparative Examples 1-11

[0077]

[0078] Note: In Comparative Examples 5 and 3, the adhesion between the moth-eye membrane and the antireflective medium or glass was unqualified, and the moth-eye membrane was easily detached and peeled off. The adhesion between the moth-eye membrane and the antireflective medium or glass was tested according to ISO 4587 and GB / T 7124-2008 "Determination of tensile shear strength of adhesives (rigid material to rigid material)".

[0079] Analysis of the data in Table 2:

[0080] 1) Comparing Examples 1, 8, 9, 5, 10, and 11, it can be seen that: when the mass fraction of the silane coupling agent is less than 2% or there is no silane coupling agent, the adhesion between the moth eye membrane and the antireflective medium membrane is unqualified; when the mass fraction of the silane coupling agent is greater than 4%, the surface water contact angle of the entire moth eye membrane structure becomes smaller, resulting in less than 150°; in addition, excessive silane coupling agent will slightly reduce the optical transmittance of the moth eye membrane structure. Therefore, the reasonable mass fraction of the silane coupling agent is between 2% and 4%.

[0081] 2) Comparing Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3, it can be seen that: compared to a blank windshield, the glass coated with the dielectric antireflective film can improve the transmittance of a 905nm wavelength signal at 65° by 4.4%, but the transmittance at 0° is reduced by 2.8%, and the water contact angle is 42°; compared to a blank windshield, the glass with a moth-eye film alone can improve the transmittance of a 905nm wavelength signal at 65° by 3.9%, the transmittance at 0° by 2.3%, and the water contact angle is 158°; compared to a blank windshield, the glass with the combined structure antireflective film of the present invention can improve the transmittance of a 905nm wavelength signal at 65° by 7.0%, the transmittance at 0° is basically the same as that of the blank glass, and the water contact angle is 156°.

[0082] 3) Comparing Example 2 and Comparative Example 6, and Example 1 and Comparative Example 7, respectively, it can be seen that when the thickness of the support layer is 252 nm, it conforms to the optical design of the dielectric antireflection film listed in Table 1. Increasing the thickness of the support layer to more than 1 / 2 of the structural layer thickness or decreasing it to less than 1 / 4 of the structural layer thickness will significantly reduce the overall optical transmittance, but there is no significant change in the surface water contact angle. Therefore, when the thickness of the structural support layer is 1 / 4 to 1 / 2 of the thickness of the moth-eye structural layer, the overall antireflection effect is better.

[0083] 4) Comparing Example 1 and Comparative Example 4, it can be seen that when a thicker adhesive layer is provided between the moth-eye membrane and the antireflective medium membrane, the antireflective effect of the combined antireflective membrane on the glass transmittance is greatly weakened, but there is no significant change in the surface water contact angle.

[0084] 5) Based on Examples 1, 6, 7, 8, and 9, we can conclude that the period of the structural layer of the moth eye membrane has a certain influence on the surface water contact angle. When the period of the structural layer is between 100nm and 200nm, the smaller the period, the larger the surface water contact angle. However, when the period of the structural layer is less than 100nm or greater than 200nm, the surface water contact angle will decrease.

[0085] In addition, the present invention provides another example of the membrane system design structure of the second type of antireflective membrane shown in Table 3.

[0086] The antireflective coating consists of a stacked structure of five high- and low-refractive-index layers (D1-D5) from the glass surface upwards, plus an outermost high-refractive-index layer (H6 in D6), for a total of 11 layers, including six Si high-refractive-index layers and five Al2O3 low-refractive-index layers. In this series of embodiments and comparative examples, the outermost low-refractive-index layer in the film system design (i.e., L6 in D6), if L6 is Al2O3 (refractive index 1.65), then the theoretical thickness of L6 (Al2O3) is 273 nm; when L6 is set as the structural support layer of the moth-eye film (refractive index 1.55), the theoretical thickness of the structural support layer is 290 nm.

[0087] Table 3. Membrane structure of the second type of antireflective medium membrane.

[0088]

[0089] Referring to the experimental design in Table 2, the variables of the more preferred moth-eye membrane structure matching the membrane system structure in Table 3 are as follows: the main resin is 95.5 parts by mass of polyurethane acrylate, the amount of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone added is 1.5 parts by mass, the amount of silane coupling agent KH550 added is 3 parts by mass, the thickness of the structural support layer of the moth-eye membrane is 290 nm, the thickness of the structural layer of the moth-eye membrane is 865 nm, the linewidth of the structural layer is 75 nm, the period of the structural layer is 150 nm, the transmittance of the corresponding 905 nm wavelength signal is 88.5% at 0° and 81.5% at 65°, and the surface water contact angle is 159°.

[0090] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A type of vehicle window glass, wherein an optical anti-reflective coating is provided on its surface; wherein, The optical antireflective coating includes an antireflective medium film and a moth-eye film; The antireflective coating comprises, sequentially disposed, a first high refractive index layer of 48 nm thickness, a first low refractive index layer of 21 nm thickness, a second high refractive index layer of 47 nm thickness, a second low refractive index layer of 112 nm thickness, a third high refractive index layer of 7 nm thickness, a third low refractive index layer of 72 nm thickness, a fourth high refractive index layer of 30 nm thickness, a fourth low refractive index layer of 52 nm thickness, a fifth high refractive index layer of 7 nm thickness, a fifth low refractive index layer of 162 nm thickness, a sixth high refractive index layer of 48 nm thickness, a sixth low refractive index layer of 20 nm thickness, and a seventh high refractive index layer of 47 nm thickness; wherein the high refractive index layer is made of Si3N4 and the low refractive index layer is made of SiO2; the moth-eye membrane is disposed on the outer surface of the seventh high refractive index layer; or The antireflective coating comprises, sequentially disposed, a first high refractive index layer of 23 nm thickness, a first low refractive index layer of 100 nm thickness, a second high refractive index layer of 40 nm thickness, a second low refractive index layer of 88 nm thickness, a third high refractive index layer of 42 nm thickness, a third low refractive index layer of 113 nm thickness, a fourth high refractive index layer of 42 nm thickness, a fourth low refractive index layer of 118 nm thickness, a fifth high refractive index layer of 46 nm thickness, a fifth low refractive index layer of 95 nm thickness, and a sixth high refractive index layer of 45 nm thickness; wherein, the high refractive index layer is made of Si, and the low refractive index layer is made of Al2O3; the moth-eye membrane is disposed on the outer surface of the sixth high refractive index layer; The materials used in the above-mentioned moth-eye membranes are all UV-curable resins, including 80-97 parts by weight of the main resin, 2-4 parts by weight of the coupling agent, and 1-2.5 parts by weight of the photoinitiator. The moth-eye membrane includes a structural support layer and a moth-eye structural layer. The structural support layer is in direct contact with the outermost high-refractive-index layer of the antireflective medium membrane. The refractive index of the structural support layer is 1.50-1.

60. In the moth-eye structural layer, the period length of the moth-eye structure is 100nm-200nm, the structural linewidth is 50nm-100nm, and the height is 400nm-1000nm. The total thickness of the moth-eye membrane is 500nm-1500nm, and the thickness of the structural support layer is 1 / 4 to 1 / 2 of that of the moth-eye structural layer. The vehicle window glass includes laminated glass, which includes an outer glass panel, an intermediate layer, and an inner glass panel. The intermediate layer is sandwiched between the outer glass plate and the inner glass plate. The outer glass plate has a first surface and a second surface facing each other, with the second surface facing the intermediate layer. The inner glass plate has a third surface and a fourth surface facing each other, with the third surface facing the intermediate layer. The laminated glass has a signal window area for the signal of the optical sensor to pass through; the optical antireflective film is provided on the fourth surface of the inner glass plate, and the antireflective medium film and the moth-eye film are arranged in sequence in the direction away from the fourth surface; in the thickness direction of the laminated glass, the projection of the optical antireflective film on the signal window area covers the signal window area. The signal window region has a transmittance of ≥80% for signals in the wavelength range of 900nm~950nm or 1500nm~1600nm when incident at an angle of 60°~67°.

2. The vehicle window glass according to claim 1, wherein, The moth eye membrane has a superhydrophobic surface, and its contact angle with water is 150°~165°.

3. The vehicle window glass according to claim 1, wherein, The main resin is selected from at least one of epoxy acrylate, polyurethane acrylate, polyester acrylate, polyether acrylate, amino acrylate, and acrylate. The coupling agent is selected from at least one of silane coupling agents, titanate coupling agents, aluminate coupling agents, and metal composite coupling agents; The photoinitiator is selected from at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzoin and its derivatives, benzoyl derivatives, dialkoxyacetophenone, α-hydroxyalkyl phenyl ketone, benzophenone and its derivatives, vinyl sulfide compounds, diazonium salts, diaryliodomonium salts, triarylthionium salts, alkylthionium salts, and iron aromatic salts.

4. The vehicle window glass according to claim 1, wherein, The signal window region has a transmittance of ≥88% for signals in the wavelength range of 900nm~950nm or 1500nm~1600nm when incident at an incident angle of 0°.

5. A vehicle comprising a vehicle body and a window glass as described in any one of claims 1-4, the window glass being connected to the vehicle body.

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