Resin lens with visible light anti-reflection coating and method for manufacturing the same

Abstract

The present application relates to the technical field of visible light antireflection film, and particularly relates to a visible light antireflection coated resin lens and a preparation method thereof, which comprises a resin base material and a coating layer arranged on at least one side of the resin base material, the coating layer comprising, from inside to outside, an interface bonding layer, a hardening layer, an antireflection film layer and a top film layer; the interface bonding layer is a covalent bonding structure formed by the free radical reaction of methyltrimethoxysilane vapor with the surface of the resin base material in a vacuum plasma environment; the antireflection film layer comprises, in sequence, an Al2O3 water-blocking layer, an Al2O3-SiO2 composite layer, a SiO2 layer, a SiO2-TiO2 composite layer and a MgF2 layer; wherein the mass proportion of SiO2 in the Al2O3-SiO2 composite layer gradually increases from inside to outside, and the mass proportion of SiO2 in the SiO2-TiO2 composite layer gradually decreases from inside to outside, and the average transmittance of the visible light antireflection coated resin lens in the visible light band is greater than or equal to 99.0%.

Description

Technical Field

[0001] The present invention relates to the technical field of visible light anti-reflection films, and in particular to a visible light anti-reflection coated resin lens and a preparation method thereof. Background Art

[0002] Resin lenses such as CR-39 and polycarbonate are gradually replacing glass lenses due to their light weight and ease of processing. However, due to issues with surface hardness and insufficient optical performance, the mainstream industrial solution is to harden the surface of the resin lenses and then vacuum coat them. This involves spin-coating a UV-curable silicone resin onto the pre-treated substrate to form a hard layer. Then, multiple layers of low-refractive-index and high-refractive-index materials are vacuum-deposited or magnetron-sputtered to form an anti-reflection coating. The lowest reflectivity is achieved at a designed wavelength of 500-550nm.

[0003] However, this discrete film design presents a conflicting relationship between optical and mechanical properties. To achieve high adhesion, increasing the transition layer thickness is necessary, but excessively thick films introduce more interface reflection and volume scattering losses. Conversely, while reducing the film thickness improves transmittance, it compromises adhesion. This dilemma limits the transmittance of traditional designs to below 95%, making it difficult for average transmittance to exceed theoretical limits. Furthermore, each additional interface introduces additional Fresnel reflection losses, further limiting optical performance improvements.

[0004] Furthermore, after a period of use or in special environments, most lenses will experience cracking or peeling of the lens coating, resulting in reduced light transmittance and increased surface patterning. This is due to a mismatch in thermal expansion coefficients between the resin substrate and the inorganic film layer. The UV-cured silicone hard layer generates tensile stress during curing and shrinkage, which, in turn, induces microcracks that become channels for water and oxygen permeation. The resin substrate's water absorption and expansion rate is much higher than that of the inorganic film layer. In a hot and humid environment (85°C / 85%RH), water vapor penetrates the resin interface through micro-defects in the film layer, inducing expansion stresses ≥15MPa and causing bubbling and delamination of the film layer. Therefore, achieving high-performance, high-durability coatings on resin lenses while simultaneously meeting visible light anti-transmittance requirements has been a long-standing technical challenge in this field.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a visible light anti-reflection coated resin lens, realize long-term stable coating of an inorganic optical film layer on a highly flexible organic resin substrate, effectively buffer thermal stress and maintain optical transparency.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A visible light anti-reflection coated resin lens, comprising a resin substrate and a coating layer disposed on at least one side of the resin substrate, wherein the coating layer comprises an interface bonding layer, a hardening layer, an anti-reflection film layer, and a top film layer disposed on the resin substrate from the inside out;

[0009] The interface bonding layer is a covalent bonding structure formed by the reaction of methyltrimethoxysilane vapor with free radicals on the surface of the resin substrate in a vacuum plasma environment; and the inorganic component of the layer is ≥90at%;

[0010] The antireflection film layer includes an Al2O3 water-blocking layer, an Al2O3-SiO2 composite layer, a SiO2 layer, a SiO2-TiO2 composite layer, and a MgF2 layer in sequence;

[0011] Among them, the mass proportion of SiO2 in the Al2O3-SiO2 composite layer gradually increases from the inside to the outside, and the mass proportion of SiO2 in the SiO2-TiO2 composite layer gradually decreases from the inside to the outside. The average transmittance of the visible light anti-reflection coated resin lens in the visible light band is ≥99.0%.

[0012] Preferably, the resin substrate is CR-39 or polycarbonate, and the refractive index of the resin substrate is 1.50-1.59.

[0013] Preferably, the interface bonding layer is an ultra-thin covalent bonding layer with no macroscopic discrete entity layer structure. It is grafted to the surface of the resin substrate through in-situ covalent bonds with a thickness of 5 to 10 nm. Most of the organic groups in the bonding layer are dissociated into volatile components by plasma, so the inorganic components of this layer are ≥ 90 at%. The Si-OC covalent bond network formed by the interface bonding layer not only improves the bonding energy between the resin substrate and the hardened layer, but also fills the micropores on the surface of the resin substrate, effectively reducing the interfacial refractive index difference and reducing Fresnel reflection. The flexible transition zone formed can absorb more than 80% of the thermal stress and improve the interface thermal stress tolerance threshold. The thickness of the interface bonding layer is less than 1 / 30 of the wavelength of visible light, does not participate in optical interference, and only serves as a chemical bonding transition layer; 5 to 10 nm can avoid the problem of thermal stress causing the anti-reflection film to crack and reduce the transmittance when the thickness is too large; and the situation where the thickness is too small and the bonding sites are insufficient, resulting in reduced adhesion.

[0014] Preferably, the interface bonding layer is formed by the following steps:

[0015] (1) Immerse the lens substrate in 60℃ alkaline cleaning solution and ultrasonically treat for 20 minutes, rinse with deionized water and blow dry with nitrogen; -2 In a plasma chamber with a RF power of 50-100W, an argon-oxygen mixed gas is introduced to pretreat the surface of the resin substrate;

[0016] (2) After dehydration of methyltrimethoxysilane with molecular sieves, low-boiling-point impurities are removed by vacuum distillation to obtain a purified monomer. Methyltrimethoxysilane (MTMS) vaporized at 80-120°C is injected into the plasma chamber to react and form a Si-OC covalently bonded structure with a thickness of 5-10 nm, which is the interface bonding layer.

[0017] Among them, vacuum degree ≤10 -2 Pa can completely eliminate the interference of water molecules and prevent silane hydrolysis byproducts from affecting the bonding purity; the volume ratio of argon to oxygen in the argon-oxygen mixture is 5~9:1. The ratio of 5~9:1 ensures the generation of sufficient oxygen free radicals to activate the resin surface while avoiding excessive etching to damage the flatness of the substrate.

[0018] Specifically, oxygen free radicals O· bombard the surface of the resin substrate, capturing alkyl hydrogen to generate resin carbon free radicals, and methyltrimethoxysilane vapor is introduced into the chamber at 10sccm through a precision flow valve; in a plasma environment, methyltrimethoxysilane dissociates into ·Si(OCH3)3 free radicals, and C· on the resin surface attacks the silicon atoms of ·Si(OCH3)3 to form Si-C covalent bonds. The residual methoxy group hydrolyzes with the ·OH generated by the plasma, condensing into a silicon-oxygen network, and finally forming an interfacial bonding layer.

[0019] Preferably, the hardened layer is obtained by spin coating an organic silicon sol containing hollow SiO2 spheres, followed by gradient curing and supercritical CO2 drying. The thickness of the hardened layer is 3-4 μm, and the refractive index is 1.46-1.52.

[0020] Preferably, calculated by mass percentage, the organic silica sol containing hollow SiO2 balls includes 35~45wt% of γ-glycidyloxypropyltrimethoxysilane, 30~40wt% of ethyl orthosilicate, 20~30wt% of hollow SiO2 balls, and 0.05~0.15wt% of dibutyltin dilaurate, and is balanced to 100wt% using anhydrous ethanol. After mixing, the mixture is ball-milled for 24 hours and aged for 48 hours to obtain the organic silica sol containing hollow SiO2 balls.

[0021] Preferably, the particle size of the hollow SiO2 sphere is 48-52 nm, the shell thickness is 7-9 nm, the cavity ratio is 38-42%, and the surface of the hollow SiO2 sphere is modified with 3-(methacryloyloxy)propyltrimethoxysilane.

[0022] Hollow SiO2 spheres are introduced into the hardened layer to form nanopores. These spheres provide stress buffering cavities, absorbing curing shrinkage stress. Their size is much smaller than the wavelength of visible light, so they do not scatter visible light and avoid interference reflection. γ-Glycidyloxypropyltrimethoxysilane provides a tough network, while ethyl orthosilicate builds a rigid framework. The three components synergistically enhance the fracture toughness of the hardened layer.

[0023] In the prior art, when the interfacial bonding force between the resin substrate and the hardening layer is ≤ 20 MPa, the antireflection film layer peels off after thermal cycling, and cannot achieve long-lasting antireflection; the interfacial bonding layer of the present application increases the bonding force to ≥ 30 MPa, creating a stable substrate for the gradient design of the antireflection film layer, which is a necessary prerequisite for achieving ultra-low reflectivity. In the present application, the methyl acryloyloxy group on the surface of the hollow SiO2 ball reacts with the epoxy group in the silica sol and the free radicals in the interfacial bonding layer to form an organic-inorganic interpenetrating network, the interfacial bonding force between the interfacial bonding layer and the hardening layer is ≥ 30 MPa, which changes the failure mode from interfacial peeling to cohesive failure in the substrate, reducing the risk of film layer falling off.

[0024] Preferably, the thickness of the Al2O3 water-blocking layer is 5-10 nm, the thickness of the Al2O3-SiO2 composite layer is 30-50 nm, the thickness of the SiO2 layer is 15-20 nm, the thickness of the SiO2-TiO2 composite layer is 50-70 nm, and the thickness of the MgF2 layer is 90-110 nm.

[0025] Preferably, the mass fraction of SiO2 in the Al2O3-SiO2 composite layer increases linearly from 30±5% to 70±5% along the film thickness direction, the mass fraction of SiO2 in the SiO2-TiO2 composite layer decreases linearly from 70±5% to 30±5% along the film thickness direction, and the gradient change rate is 0.9-1.1% / nm. Matching the gradient change rate can widen the visible light spectrum, ensuring that the reflectivity of blue light (450 nm) and red light (650 nm) is suppressed simultaneously.

[0026] Further preferably, the thickness of the Al2O3 water-blocking layer is 5-10 nm, and the refractive index is 1.72-1.80; the thickness of the Al2O3-SiO2 composite layer is 30-50 nm, and the refractive index gradually changes from 1.65-1.70 to 1.46-1.50, buffering the stress between Al2O3 and the subsequent low refractive index layer; the thickness of the SiO2 layer is 15-20 nm, and the refractive index is 1.45-1.47; the present application forms an optical hub between the Al2O3-SiO2 composite layer and the SiO2-TiO2 composite layer; the Young's modulus is between the high modulus water-blocking layer and the low modulus gradient layer, which can reduce the modulus jump amplitude between the film layers and suppress the expansion of micro-cracks caused by thermal stress; the thickness of the SiO2-TiO2 composite layer is 50-70 nm, and the refractive index gradually changes from 1.46-1.50 to 2.10-2.20, with the lowest refractive index point matching the SiO2 layer; the highest refractive index point forms an interference pair with the MgF2 layer; the thickness of the MgF2 layer is 90-110 nm, and the refractive index is 1.28-1.42.

[0027] The dual electron beam evaporation source in the Al2O3-SiO2 composite layer realizes spatial superposition of Al2O3 and SiO2 sputtering particle flows through angle control, and linear regulation of evaporation rate is combined to obtain continuous and gradual change of refractive index. The Fresnel reflection loss caused by the discrete interface of the traditional film system is eliminated, the reflectivity fluctuation in the full visible light band is effectively reduced, and the hardness mutation between the Al2O3 water-blocking layer and the SiO2 layer is relieved, thereby reducing the risk of film cracking. The gradual change of refractive index formed can widen the antireflection bandwidth and reduce residual reflection color.

[0028] The dual electron beam evaporation source in the SiO2-TiO2 composite layer realizes spatial superposition of TiO2 and SiO2 sputtering particle flows through angle control, and linear regulation of evaporation rate is combined to obtain continuous and gradual change of refractive index. The rate regulation algorithm adopts PID closed-loop control, and the feedback signal comes from the quartz crystal thickness meter. The angle between the target plane of the dual electron beam evaporation source and the normal line of the substrate is initially 15° (SiO2 source) and 30° (TiO2 source), and is synchronously adjusted in the opposite direction at a rate of 0.5° / min during deposition, ensuring that the composition gradient change rate in the sputtering particle flow superposition area is 1.0±0.1% / nm. The Al2O3-SiO2 composite layer adopts the same adjustment method.

[0029] As preferred, the preparation method of the antireflection film layer comprises the following steps:

[0030] An Al2O3 water-blocking layer is deposited on the surface of the hardening layer by electron beam evaporation;

[0031] An Al2O3-SiO2 composite layer with SiO2 mass fraction increasing from 30±5% to 70±5% is deposited on the Al2O3 water-blocking layer by dual electron beam co-evaporation, and the SiO2 evaporation rate is linearly increased from 0.1 Å / s to 0.5 Å / s; the refractive index mutation between the Al2O3 and SiO2 layers is eliminated, and the interface reflection loss is reduced;

[0032] A SiO2 layer is deposited, and then a SiO2-TiO2 composite layer with SiO2 mass fraction decreasing from 70±5% to 30±5% is formed by dual electron beam co-evaporation, and the TiO2 evaporation rate is linearly increased from 0.1 Å / s to 0.6 Å / s; the refractive index is reversely graded, and a "V-shaped" optical compensation structure is formed with the inner Al2O3-SiO2 layer, thereby reducing the reflectivity in the full visible light band;

[0033] A MgF2 layer is deposited on the SiO2-TiO2 composite layer, and the substrate temperature is maintained at 80±5°C without ion beam assistance during deposition, so that the MgF2 is maintained in an amorphous state to avoid scattering loss caused by grain boundaries.

[0034] Preferably, the hollow SiO2 balls in the hardened layer form surface undulations, and the Al2O3 water-blocking layer is deposited in an island growth mode. The bonding is enhanced by mechanical interlocking, so that the interface bonding force between the antireflection film layer and the hardened layer is ≥25MPa, effectively reducing interface slip.

[0035] Preferably, the top film layer comprises a nano-MgF2-reinforced silica film and a perfluoropolyether antifouling layer, arranged sequentially from the inside out. The nano-MgF2-reinforced silica film has a thickness of 14-16 nm, a refractive index of 1.28-1.35, a MgF2 content of 28-32 wt%, and a porosity of 43-47%. The perfluoropolyether antifouling layer has a thickness of 2.5-3.5 nm. The MgF2 nanocrystals fill the pores to increase hardness, while the pores adsorb the perfluoropolyether to form a -CF2-Si-O-covalent bond. The -CF3 terminal groups of the perfluoropolyether ensure a contact angle of ≥120° and reduce oil adhesion to ≤5 μN.

[0036] The second object of the present invention is to provide a method for preparing a visible light anti-reflection coated resin lens, so as to achieve a synergistic effect of ultra-high average transmittance of the resin lens in the visible light band and long-term stability of the film layer.

[0037] In order to achieve the above object, the technical solution adopted by the present invention is:

[0038] A method for preparing a visible light anti-reflection coated resin lens, characterized by comprising:

[0039] The S1 resin substrate was activated by Ar / O2 mixed gas plasma at ≤10 -2 Pa vacuum reacts with methyltrimethoxysilane vapor to form a 5~10nm covalent bonding structure, namely the interface bonding layer;

[0040] S2 spin-coats the organic silicon sol containing hollow SiO2 spheres prepared by the sol-gel method onto the interfacial bonding layer, and obtains a 3-4 μm hardened layer through gradient curing and supercritical CO2 drying, which can reduce the curing shrinkage stress and avoid pore collapse.

[0041] S3 sequentially deposits a 5-10 nm Al2O3 water-blocking layer, a 30-50 nm Al2O3-SiO2 composite layer, a 15-20 nm SiO2 layer, a 50-70 nm SiO2-TiO2 composite layer, and a 90-110 nm MgF2 layer on the hardened layer to form an antireflection film.

[0042] S4 spin-coats a silica sol containing MgF2 nanocrystals on the anti-reflection film layer, and after curing, vapor deposits a perfluoropolyether anti-fouling layer to obtain a visible light anti-reflection coated resin lens.

[0043] The beneficial effects of the present invention are:

[0044] Prior to hard coating, the present invention subjects the cleaned resin lens to a low-temperature plasma treatment, while simultaneously introducing methyltrimethoxysilane vapor. The plasma activates the lens surface and triggers graft polymerization of monomers on the surface, forming a strongly chemically bonded organic silicon interface layer with a gradient cross-linked structure. The flexibility of the interface bonding layer effectively buffers stress between the inorganic film layer and the resin substrate, providing an excellent anchor point for the film layer and significantly improving adhesion. The ultra-thin design of the interface bonding layer can fill the submicron pores of the resin substrate itself, resulting in molecular-level flatness on the resin substrate surface. This effectively reduces the interfacial refractive index difference, enhances the anti-reflection effect, and avoids optical path interference effects.

[0045] This invention utilizes a five-layer precision film system to create a unique V-shaped gradient refractive index structure. This reduces reflection through phase cancellation. By precisely controlling the composition gradients of the Al2O3-SiO2 and SiO2-TiO2 composite film layers, a continuously varying refractive index profile is created, keeping reflectance fluctuations within 0.15% across the entire 400-700nm wavelength range. Ultimately, this achieves an ultra-high average transmittance of 99%, approaching the intrinsic transmittance limit of resin materials. The invention also incorporates a SiO2 layer between the two gradient composite layers as a stress buffer, significantly broadening the anti-reflection bandwidth and reducing residual color. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic structural diagram of a visible light anti-reflection coated resin lens according to the present invention;

[0047] Figure 2 Schematic diagram of the structure of the coating layer;

[0048] Figure 3 is a curve diagram of the change of thickness and refractive index in the Al2O3-SiO2 composite layer;

[0049] Figure 4 This is a curve diagram of the change in thickness and refractive index in the SiO2-TiO2 composite layer.

[0050] Figure numerals: 10, resin substrate; 20, interface bonding layer; 30, hardening layer; 40, anti-reflection film layer; 50, top film layer; 41, Al2O3 water-blocking layer; 42, Al2O3-SiO2 composite layer; 43, SiO2 layer; 44, SiO2-TiO2 composite layer; 45, MgF2 layer; 51, nano-MgF2 enhanced silica film; 52, perfluoropolyether antifouling layer. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0053] like Figure 1 and Figure 2 As shown, the visible light anti-reflection coated resin lens comprises a resin substrate 10 and a coating layer disposed on at least one side of the resin substrate 10. It should be noted that the resin substrate 10 is CR-39 or polycarbonate, and the refractive index of the resin substrate 10 is 1.50-1.59. CR-39 excels in optical precision and chemical stability, while polycarbonate is more impact-resistant and lightweight. Persons skilled in the art can select the appropriate material based on the application scenario.

[0054] The coating layer includes an interface bonding layer 20, a hardening layer 30, an anti-reflection film layer 40 and a top film layer 50 arranged on the resin substrate 10 from the inside to the outside;

[0055] The interfacial bonding layer 20 is a covalently bonded structure formed by the reaction of methyltrimethoxysilane vapor with free radicals on the surface of the resin substrate 10 in a vacuum plasma environment. It should be noted that the interfacial bonding layer 20 is in situ covalently grafted onto the surface of the resin substrate 10 to achieve molecular-level bonding with the resin substrate 10. Most organic groups in the bonding layer are dissociated into volatile components by the plasma, so the inorganic component content of this layer is ≥90at%. The Si-OC covalent bond network formed by the interfacial bonding layer 20 not only improves the bonding energy between the resin substrate 10 and the hardening layer 30, but also fills the micropores on the surface of the resin substrate 10, effectively reducing the interfacial refractive index difference and Fresnel reflection. The resulting flexible transition zone can absorb more than 80% of thermal stress, thereby improving the interfacial thermal stress tolerance threshold. The thickness of the interface bonding layer 20 is less than 1 / 30 of the wavelength of visible light, does not participate in optical interference, and only serves as a chemical bonding transition layer; it is specifically limited to 5~10nm to avoid the problem of thermal stress causing increased cracking rate of the antireflection film and decreased transmittance when the thickness is too large; and the problem of insufficient bonding sites leading to reduced adhesion when the thickness is too small.

[0056] The hardened layer 30 is obtained by spin-coating an organosilica sol containing hollow SiO2 spheres, followed by gradient curing and supercritical CO2 drying. The thickness of the hardened layer 30 is 3-4 μm, and the refractive index is 1.46-1.52. The specific parameters of the gradient curing and supercritical CO2 drying can be adjusted by those skilled in the art to achieve coating uniformity.

[0057] The organic silica sol containing hollow SiO2 spheres comprises, by mass percentage, 35-45wt% of γ-glycidyloxypropyltrimethoxysilane, 30-40wt% of ethyl orthosilicate, 20-30wt% of hollow SiO2 spheres, and 0.05-0.15wt% of dibutyltin dilaurate. The mixture is balanced to 100wt% with anhydrous ethanol, ball-milled for 24 hours, and aged for 48 hours to obtain the organic silica sol containing hollow SiO2 spheres. The hollow SiO2 spheres have a particle size of 48-52nm, a shell thickness of 7-9nm, and a cavity fraction of 38-42%. The surface of the hollow SiO2 spheres is modified with 3-(methacryloyloxy)propyltrimethoxysilane.

[0058] Hollow SiO2 balls are introduced into the hardened layer 30 to form nanopores. The hollow SiO2 balls provide stress buffering holes and absorb curing shrinkage stress. Their size is much smaller than the wavelength of visible light, does not scatter visible light, and avoids interference reflection. γ-glycidyloxypropyltrimethoxysilane provides a tough network, and ethyl orthosilicate builds a rigid skeleton. The three components work together to improve the fracture toughness of the hardened layer 30. The methacryloyloxy group modified on the surface of the hollow SiO2 balls in the present invention reacts with the epoxy group in the silica sol and the free radicals in the interface bonding layer to form an organic-inorganic interpenetrating network. The interface bonding force between the interface bonding layer 20 and the hardened layer 30 is ≥30MPa, which changes the failure mode from interface peeling to cohesive failure of the substrate, reducing the risk of film shedding.

[0059] Specific as Figure 2 As shown, the antireflection film layer 40 includes an Al2O3 water-blocking layer 41, an Al2O3-SiO2 composite layer 42, a SiO2 layer 43, a SiO2-TiO2 composite layer 44, and a MgF2 layer 45 in sequence;

[0060] The SiO2 mass fraction in the Al2O3-SiO2 composite layer 42 increases linearly from 30±5% to 70±5% along the film thickness, while the SiO2 mass fraction in the SiO2-TiO2 composite layer 44 decreases linearly from 70±5% to 30±5% along the film thickness, with the gradient rate of change ranging from 0.9% to 1.1% / nm. This gradient rate matches the wide visible light spectrum, ensuring simultaneous suppression of blue light (450nm) and red light (650nm) reflectivity. The average transmittance of the visible light anti-reflection coated resin lens in the visible light band is ≥99.0%.

[0061] It should be noted that the thickness of the Al2O3 water-blocking layer 41 is 5-10 nm, and the refractive index is 1.72-1.80; the thickness of the Al2O3-SiO2 composite layer 42 is 30-50 nm, and the refractive index gradually changes from 1.65-1.70 to 1.46-1.50, which buffers the stress of the Al2O3 and the subsequent low-refractive-index layer. Figure 3As shown, the thickness of the SiO2 layer 43 is 15-20nm, and the refractive index is 1.45-1.47. The present invention forms an optical hub between the Al2O3-SiO2 composite layer 42 and the SiO2-TiO2 composite layer 44; its Young's modulus is between the high modulus water-blocking layer and the low modulus gradient layer, which can reduce the modulus jump amplitude between the film layers and inhibit the expansion of microcracks caused by thermal stress. The thickness of the SiO2-TiO2 composite layer 44 is 50-70nm, and the refractive index gradually changes from 1.46-1.50 to 2.10-2.20. Figure 4 As shown, the lowest refractive index point matches the SiO2 layer 43; the highest refractive index point forms an interference pair with MgF2, and the thickness of the MgF2 layer 45 is 90-110 nm, and the refractive index is 1.28-1.42.

[0062] In the Al2O3-SiO2 composite layer 42, the dual electron beam evaporation source achieves spatial superposition of the Al2O3 and SiO2 sputtering particle streams through tilt control. Combined with linear regulation of the evaporation rate, this results in a continuous refractive index gradient. This eliminates Fresnel reflection losses caused by discrete interfaces in traditional film systems, effectively reducing reflectivity fluctuations across the entire visible light band. It also mitigates the sudden hardness change between the Al2O3 water-blocking layer and the SiO2 layer, reducing the risk of film cracking. The resulting gradient refractive index broadens the anti-reflection bandwidth and reduces residual reflection color.

[0063] In the SiO2-TiO2 composite layer 44, the dual electron-beam evaporation source achieves spatial superposition of the TiO2 and SiO2 sputtering particle streams through tilt control. Combined with linear evaporation rate regulation, this achieves a continuous gradient of refractive index. The rate control algorithm utilizes PID closed-loop control, with feedback from a quartz crystal film thickness meter. The initial angles between the target plane and the substrate normal of the dual electron-beam evaporation source are 15° (SiO2 source) and 30° (TiO2 source). During deposition, these angles are synchronously reversed at a rate of 0.5° / min to ensure a composition gradient change rate of 1.0±0.1% / nm in the superposition region of the sputtering particle streams. The same adjustment method is used for the Al2O3-SiO2 composite layer 42.

[0064] The hollow SiO2 balls in the hardened layer 30 form surface undulations, and the Al2O3 water-blocking layer 41 is deposited in an island growth mode. The mechanical interlocking enhances the bonding, so that the interface bonding force between the antireflection film layer 40 and the hardened layer 30 is ≥25MPa, effectively reducing interface slip.

[0065] The top film layer 50 comprises, from inside to outside, a nano-MgF2 reinforced silica film 51 and a perfluoropolyether antifouling layer 52; the thickness of the nano-MgF2 reinforced silica film 51 is 14-16 nm, the refractive index is 1.28-1.35, the MgF2 content is 28-32 wt%, and the porosity is 43-47%; the thickness of the perfluoropolyether antifouling layer 52 is 2.5-3.5 nm. Among them, the MgF2 nanocrystals fill the pores to improve the hardness, and the pores adsorb perfluoropolyether to form a -CF2-Si-O- covalent bond; the perfluoropolyether -CF3 end group makes the contact angle ≥120°, and the oil stain adhesion is reduced to ≤5 μN.

[0066] Specifically, the preparation method of the visible light anti-reflection coated resin lens in the present application comprises:

[0067] S1 immerse the lens substrate in a 60℃ alkaline cleaning solution for ultrasonic treatment for 20 min, rinse with deionized water, and dry with nitrogen; under a vacuum degree ≤10 -2 In a plasma chamber with a power of 50-100 W, the surface of the resin substrate 10 is pretreated by introducing argon-oxygen mixed gas; after methyltrimethoxysilane is dehydrated by molecular sieves, low-boiling-point impurities are removed by vacuum distillation to obtain purified monomers. The plasma chamber is injected with 80-120℃ vaporized methyltrimethoxysilane (MTMS) steam, and a covalent bond structure with a thickness of 5-10 nm, Si-O-C, is generated by reaction, which is the interface bonding layer 20.

[0068] S2 disperse the hollow SiO2 balls modified by 3-(methacryloyloxy) propyl trimethoxysilane in ethanol, ultrasonic treatment for 30 min, add γ-glycidyl ether propyl trimethoxysilane, tetraethyl orthosilicate, and catalyst, and magnetically stir under nitrogen protection for 2 h; under the condition of 25℃ and light avoidance for 48 h, the hydrolysis degree reaches ≥90%, the organic silica sol containing hollow SiO2 balls prepared by sol-gel method is spin-coated on the interface bonding layer 20, and gradient curing and supercritical CO2 drying are performed to obtain a hardening layer 30 with a thickness of 3-4 μm;

[0069] S3 deposits an Al2O3 water-blocking layer 41 on the surface of the hardened layer 30 by electron beam evaporation; deposits an Al2O3-SiO2 composite layer 42 on the Al2O3 water-blocking layer by double electron beam co-evaporation, wherein the SiO2 mass ratio increases from 30±5% to 70±5%, and controls the SiO2 evaporation rate to increase linearly from 0.1Å / s to 0.5Å / s; eliminates the refractive index mutation between the Al2O3 and SiO2 layers 43, and reduces the interface reflection loss; deposits the SiO2 layer 43, and then forms a SiO2 mass layer by double electron beam co-evaporation. The SiO2-TiO2 composite layer 44 was reduced from 70±5% to 30±5%, and the TiO2 evaporation rate was controlled to increase linearly from 0.1Å / s to 0.6Å / s; a reverse gradient of the refractive index was achieved, forming a "V-shaped" optical compensation structure with the inner layer Al2O3-SiO2, thereby reducing the reflectivity of the entire visible light band; a MgF2 layer 45 was deposited on the SiO2-TiO2 composite layer. During the deposition process, the substrate temperature was maintained at 80±5℃ without ion beam assistance, so as to maintain the MgF2 in an amorphous state and avoid scattering losses caused by grain boundaries.

[0070] S4 MgF2 nanocrystals are blended with silica sol and ball-milled for 24 hours. Fluorosilane is then added and aged for 24 hours to form a silica sol containing MgF2 nanocrystals. The silica sol containing MgF2 nanocrystals is spin-coated onto the anti-reflection film layer 40. After curing, a perfluoropolyether antifouling layer 52 is vapor-deposited to form a visible light anti-reflection coated resin lens.

[0071] Example 1:

[0072] The visible light anti-reflection coated resin lens comprises a resin substrate 10 and a coating layer arranged on at least one side of the resin substrate 10, wherein the resin substrate 10 is CR-39.

[0073] The coating layer includes a 5 nm interface bonding layer 20, a 3 μm hardening layer 30, a 190 nm anti-reflection film layer 40 and a 16.5 nm top film layer 50 arranged on the resin substrate 10 from the inside to the outside;

[0074] The interface bonding layer 20 is methyltrimethoxysilane vapor at a vacuum degree of ≤10 -2 The covalent bonding structure is formed by reacting with free radicals formed on the surface of the resin substrate 10 pretreated by passing an argon-oxygen mixed gas (argon-oxygen volume ratio 5:1) in a plasma chamber with a power of 80W.

[0075] The organic silica sol containing hollow SiO2 balls of the hardened layer 30 is prepared by mixing 35 wt% of γ-glycidyloxypropyltrimethoxysilane, 40 wt% of ethyl orthosilicate, 20 wt% of hollow SiO2 balls, and 0.05 wt% of dibutyltin dilaurate, and balancing to 100 wt% with anhydrous ethanol, ball milling for 24 hours, and aging for 48 hours.

[0076] The 190nm antireflection film 40 sequentially includes a 5nm Al2O3 water-blocking layer 41, a 30nm Al2O3-SiO2 composite layer 42 (the mass proportion of SiO2 increases linearly from 32% to 68% along the film thickness direction, with a gradient change rate of 0.9% / nm), a 15nm SiO2 layer 43, a 50nm SiO2-TiO2 composite layer 44 (the mass proportion of SiO2 decreases linearly from 72% to 28% along the film thickness direction, with a gradient change rate of 0.9% / nm), and a 90nm MgF2 layer 45.

[0077] The 16.5 nm top film layer 50 includes a 14 nm nano-MgF 2 reinforced silicon dioxide film 51 and a 2.5 nm perfluoropolyether antifouling layer 52 arranged sequentially from the inside to the outside.

[0078] Example 2:

[0079] The visible light anti-reflection coated resin lens comprises a resin substrate 10 and a coating layer arranged on at least one side of the resin substrate 10, wherein the resin substrate 10 is polycarbonate.

[0080] The interface bonding layer 20 is methyltrimethoxysilane vapor at a vacuum degree of ≤10 -2 The covalent bonding structure is formed by reacting with free radicals formed on the surface of the resin substrate 10 pretreated by introducing an argon-oxygen mixed gas (argon-oxygen volume ratio 7:1) in a plasma chamber with a power of 90W.

[0081] The coating layer includes an 8nm interface bonding layer 20, a 3.5μm hardening layer 30, a 220nm antireflection film layer 40 and an 18nm top film layer 50 arranged on the resin substrate 10 from the inside to the outside;

[0082] The 220nm antireflection film 40 sequentially includes an 8nm Al2O3 water-blocking layer 41, a 40nm Al2O3-SiO2 composite layer 42 (the mass proportion of SiO2 increases linearly from 30% to 70% along the film thickness direction, with a gradient change rate of 1% / nm), a 17nm SiO2 layer 43, a 60nm SiO2-TiO2 composite layer 44 (the mass proportion of SiO2 decreases linearly from 70% to 30% along the film thickness direction, with a gradient change rate of 1% / nm), and a 95nm MgF2 layer 45.

[0083] The 18nm top film layer 50 includes a 15nm nano-MgF2 reinforced silicon dioxide film 51 and a 3nm perfluoropolyether antifouling layer 52 arranged in sequence from the inside to the outside.

[0084] Example 3:

[0085] The visible light anti-reflection coated resin lens comprises a resin substrate 10 and a coating layer arranged on at least one side of the resin substrate 10, wherein the resin substrate 10 is CR-39.

[0086] The coating layer includes a 10 nm interface bonding layer 20, a 4 μm hardening layer 30, a 260 nm anti-reflection film layer 40 and a 19.5 nm top film layer 50 arranged on the resin substrate 10 from the inside to the outside;

[0087] The interface bonding layer 20 is methyltrimethoxysilane vapor at a vacuum degree of ≤10 -2 The covalent bonding structure is formed by reacting with free radicals formed on the surface of the resin substrate 10 pretreated by introducing an argon-oxygen mixed gas (argon-oxygen volume ratio 9:1) in a plasma chamber with a power of 90W.

[0088] The 260nm antireflection film 40 sequentially includes a 10nm Al2O3 water-blocking layer 41, a 50nm Al2O3-SiO2 composite layer 42 (the mass proportion of SiO2 increases linearly from 28% to 72% along the film thickness direction, with a gradient change rate of 1.1% / nm), a 20nm SiO2 layer 43, a 70nm SiO2-TiO2 composite layer 44 (the mass proportion of SiO2 decreases linearly from 68% to 32% along the film thickness direction, with a gradient change rate of 1.1% / nm), and a 110nm MgF2 layer 45.

[0089] The 19.5 nm top film layer 50 includes a 16 nm nano-MgF 2 reinforced silicon dioxide film 51 and a 3.5 nm perfluoropolyether antifouling layer 52 arranged sequentially from the inside to the outside.

[0090] Comparative Example 1:

[0091] The interface bonding layer 20 is formed by wet coating 200 nm of methyltrimethoxysilane, and the rest is the same as in Example 1.

[0092] Comparative Example 2:

[0093] There is no interface bonding layer 20 , and the rest is the same as in Example 1.

[0094] Comparative Example 3:

[0095] The two components in the Al2O3-SiO2 composite layer 42 and the SiO2-TiO2 composite layer 44 are constant at 1:1 without gradual change, and the rest are the same as in Example 1.

[0096] Performance Verification:

[0097] The lenses of the embodiments and comparative examples were tested in accordance with QB / T 2506-2017, GB 10810.3-2006 and industry regulations.

[0098]

[0099] Among them, the bonding layer-hardened layer bonding strength test in Comparative Example 2 is the bonding strength between the hardened layer and the resin substrate. As can be seen from the above, in Comparative Example 1, methyltrimethoxysilane is hydrolyzed and condensed in ethanol to generate cyclic siloxane by-products to form water vapor permeation channels, which significantly attenuates the bonding strength. In addition, the 200nm thick layer participates in optical interference, resulting in additional reflection losses at 550nm, resulting in a decrease in the average transmittance; in Comparative Example 2, the interface bonding layer is cancelled, the modulus of the resin substrate and the hardened layer jumps and there is no buffer layer, and stress is concentrated under the action of external force, resulting in overall performance degradation. In Comparative Example 3, the gradient layer is changed to a homogeneous layer, and the hardness between the homogeneous layers suddenly changes, causing the interface reflection to accumulate, thereby losing transmittance.

[0100] Prior to hard coating, the present invention subjects the cleaned resin lens to a low-temperature plasma treatment, while simultaneously introducing methyltrimethoxysilane vapor. The plasma activates the lens substrate surface and triggers graft polymerization of monomers on the surface, forming a strongly chemically bonded organic silicon interface layer with a gradient cross-linked structure. The flexibility of the interface bonding layer effectively buffers stress between the inorganic film layer and the resin substrate, providing excellent anchoring points for the film layer and significantly improving adhesion. The ultra-thin design of the interface bonding layer can fill the submicron pores of the resin substrate itself, resulting in molecular-level flatness on the resin substrate surface. This effectively reduces the interfacial refractive index difference, enhances the anti-reflection effect, and mitigates optical path interference effects.

[0101] This invention utilizes a five-layer precision film system to create a unique V-shaped gradient refractive index structure. This reduces reflection through phase cancellation. By precisely controlling the composition gradients of the Al2O3-SiO2 and SiO2-TiO2 composite film layers, a continuously varying refractive index profile is created, keeping reflectance fluctuations within 0.15% across the entire 400-700nm wavelength range. Ultimately, this achieves an ultra-high average transmittance of 99%, approaching the intrinsic transmittance limit of resin materials. The invention also incorporates a SiO2 layer between the two gradient composite layers as a stress buffer, significantly broadening the anti-reflection bandwidth and reducing residual color.

[0102] Those skilled in the art will appreciate that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Visible light anti-reflection coated resin lens, characterized in that: It includes a resin substrate and a coating layer arranged on at least one side of the resin substrate, wherein the coating layer includes an interface bonding layer, a hardening layer, an anti-reflection film layer and a top film layer arranged on the resin substrate from the inside to the outside; The interface bonding layer is a covalent bonding structure formed by the reaction of methyltrimethoxysilane vapor with free radicals on the surface of the resin substrate in a vacuum plasma environment; The antireflection film layer includes an Al2O3 water-blocking layer, an Al2O3-SiO2 composite layer, a SiO2 layer, a SiO2-TiO2 composite layer, and a MgF2 layer in sequence; Among them, the mass proportion of SiO2 in the Al2O3-SiO2 composite layer gradually increases from the inside to the outside, and the mass proportion of SiO2 in the SiO2-TiO2 composite layer gradually decreases from the inside to the outside. The average transmittance of the visible light anti-reflection coated resin lens in the visible light band is ≥99.0%.

2. The visible light anti-reflection coated resin lens according to claim 1, characterized in that: The interface bonding layer is formed by the following steps: (1) When the vacuum degree is ≤10 -2 In a plasma chamber with a RF power of 50-100W, an argon-oxygen mixed gas is introduced to pretreat the surface of the resin substrate; (2) Methyltrimethoxysilane vapor vaporized at 80-120° C. is injected into the plasma chamber to react and generate a Si-OC covalent bonding structure with a thickness of 5-10 nm, which is the interface bonding layer.

3. The visible light anti-reflection coated resin lens according to claim 1, characterized in that: The hardening layer is obtained by spin coating an organic silicon sol containing hollow SiO2 balls, followed by gradient curing and supercritical CO2 drying. The thickness of the hardening layer is 3-4 μm.

4. The visible light anti-reflection coated resin lens according to claim 3, characterized in that: Calculated by mass percentage, the organic silica sol containing hollow SiO2 balls includes 35-45wt% of γ-glycidyloxypropyltrimethoxysilane, 30-40wt% of ethyl orthosilicate, 20-30wt% of hollow SiO2 balls, and 0.05-0.15wt% of dibutyltin dilaurate.

5. The visible light anti-reflection coated resin lens according to claim 1, characterized in that: The thickness of the Al2O3 water-blocking layer is 5~10nm, the thickness of the Al2O3-SiO2 composite layer is 30~50nm, the thickness of the SiO2 layer is 15~20nm, the thickness of the SiO2-TiO2 composite layer is 50~70nm, and the thickness of the MgF2 layer is 90~110nm.

6. The visible light anti-reflection coated resin lens according to claim 5, characterized in that: The mass proportion of SiO2 in the Al2O3-SiO2 composite layer increases linearly from 30±5% to 70±5% along the film thickness direction, and the mass proportion of SiO2 in the SiO2-TiO2 composite layer decreases linearly from 70±5% to 30±5% along the film thickness direction, and the gradient change rate is 0.9~1.1% / nm.

7. The visible light anti-reflection coated resin lens according to claim 5, characterized in that: The method for preparing the antireflection film comprises the following steps: On the surface of the hardened layer, an Al2O3 water-blocking layer is deposited by electron beam evaporation; By double electron beam co-evaporation, an Al2O3-SiO2 composite layer with a SiO2 mass ratio increased from 30±5% to 70±5% is deposited on the Al2O3 water-blocking layer, and the SiO2 evaporation rate is controlled to increase linearly from 0.1Å / s to 0.5Å / s; A SiO2 layer was deposited, and then a SiO2-TiO2 composite layer was formed by double electron beam co-evaporation, in which the SiO2 mass fraction was reduced from 70±5% to 30±5%. The TiO2 evaporation rate was controlled to increase linearly from 0.1Å / s to 0.6Å / s. A MgF2 layer is deposited on the SiO2-TiO2 composite layer, wherein the substrate temperature is maintained at 80±5° C. without ion beam assistance.

8. The visible light anti-reflection coated resin lens according to claim 1, characterized in that: The interface bonding force between the interface bonding layer and the hardened layer is ≥30 MPa; the interface bonding force between the antireflection film layer and the hardened layer is ≥25 MPa.

9. The visible light anti-reflection coated resin lens according to claim 1, characterized in that: The top film layer includes a nano-MgF2-reinforced silica film and a perfluoropolyether antifouling layer arranged in sequence from the inside to the outside; the thickness of the nano-MgF2-reinforced silica film is 14-16 nm, the MgF2 content is 28-32 wt%, and the porosity is 43-47%; the thickness of the perfluoropolyether antifouling layer is 2.5-3.5 nm.

10. A method for preparing a visible light anti-reflection coated resin lens, characterized in that: include: The S1 resin substrate is activated by argon-oxygen mixed gas plasma at ≤10 -2 Pa vacuum reacts with methyltrimethoxysilane vapor to form a 5~10nm covalent bonding structure, namely the interface bonding layer; S2 spin-coats the organic silicon sol containing hollow SiO2 spheres prepared by the sol-gel method onto the interface bonding layer, and obtains a 3-4 μm hardened layer through gradient curing and supercritical CO2 drying. S3 sequentially depositing a 5-10 nm Al2O3 water-blocking layer, a 30-50 nm Al2O3-SiO2 composite layer, a 15-20 nm SiO2 layer, a 50-70 nm SiO2-TiO2 composite layer, and a 90-110 nm MgF2 layer on the hardened layer to form an antireflection film; S4: spin-coating a silica sol containing MgF2 nanocrystals on the anti-reflection film layer, and vapor-depositing a perfluoropolyether anti-fouling layer after curing to obtain the visible light anti-reflection coated resin lens.

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