Optical article having a multilayer antireflection coating comprising a encapsulated metal film

Abstract

This invention relates to an optical article comprising a transparent substrate having a front main surface and a rear main surface, at least one of which is coated with a multilayer antireflective coating, the multilayer antireflective coating comprising: at least one low refractive index layer (LI) having a refractive index less than 1.55 at 550 nm, hereinafter referred to as a first LI layer; a first high refractive index layer (HI) having a refractive index greater than or equal to 1.55 at 550 nm, hereinafter referred to as a first HI layer; and an encapsulating metal film (EMF), the encapsulating metal film comprising metal island layers (MIL) encapsulated between the first layer (L1) and the second layer (L2), wherein the first... Both layer (L1) and the second layer (L2) are composed of at least one dielectric material, characterized in that: - the first layer (L1) is a second L1 layer having a refractive index of less than 1.55 at 550 nm and a physical thickness equal to or greater than 10 nm; - the metal island layer (MIL) has a plasma effect and an effective thickness ranging from 0.2 nm to 4 nm, preferably from 0.5 nm to 4 nm; - the second layer (L2) has a physical thickness equal to or greater than 10 nm, wherein the multilayer antireflective coating has an average light reflectance coefficient R in the visible light region on the front and / or back of the optical article. v The average light reflectance coefficient is equal to or less than 2.5% for an incident angle of at least less than 35°, and preferably for an incident angle of 0°. The light absorption of the AR stack is mainly caused by the MIL layer.

Description

1. Technical Field

[0001] This invention relates to an optical article comprising a multilayer antireflective coating, the multilayer antireflective coating being colored in transmission. The optical article is particularly suitable for ophthalmic lenses, such as spectacle lenses. 2. Background Technology

[0002] Anti-reflective coatings typically consist of multiple layers, including thin, transparent interferometric layers, usually based on alternating layers of high-refractive-index and low-refractive-index dielectric materials. When deposited on a transparent substrate, this coating functions to reduce light reflection and thus increase light transmission. The substrate thus coated will have an increased transmitted / reflected light ratio, thereby improving the visibility of objects placed behind it. When seeking maximum anti-reflective effect, it is preferable to apply this type of coating to both sides of the substrate (front and back).

[0003] Such anti-reflective coatings are commonly used in ophthalmology. Accordingly, conventional anti-reflective coatings are designed and optimized to reduce reflections on the lens surface in the visible light region (typically in the 380nm to 780nm spectral range). Typically, the average light reflectance R in the visible light region on the front and / or back of an ophthalmic lens is... v Less than 2.5%, more preferably between 0.4% and less than 2.5%, and even more preferably between 0.5% and less than 1%.

[0004] In most cases, antireflective coatings exhibit a perceived residual reflected color, which is further associated with a perceived residual transmitted color. Specifically, the transmitted residual color is complementary to the reflected color of the clear lens. In practice, conventional antireflective coatings consisting of thin, transparent layers, as described above, cannot break the dependency between the residual colors in transmission and reflection.

[0005] Therefore, there is a need for a novel antireflective coating that can separate the reflected transmitted color from the reflected complementary color.

[0006] Several solutions have already been disclosed in the existing technology.

[0007] For example, existing solutions associate colored lens substrates coated with an anti-reflective coating. The coloring of the substrate can be provided by pigments or additives contained in or sprayed into the substrate.

[0008] Another solution involves introducing a continuous thin film of metal, such as silver (Ag), gold (Au), or copper (Cu), into a multilayer antireflective coating. However, this solution does not offer the flexibility to customize the transmitted color and results in increased yellowness and an overall increase in light absorption in the visible spectrum. For many ophthalmic applications, this yellowness is aesthetically unacceptable and may interfere with the user's normal color perception if the optics are ophthalmic lenses.

[0009] Therefore, compared with existing anti-reflective coatings, there is still a need for an anti-reflective coating for optical products, especially for ophthalmic lenses, which has very good anti-reflective properties in the visible light region and has a customized transmission color.

[0010] It is also necessary to provide such an anti-reflective coating without preferably increasing the yellowness (high b* value) according to the international colorimetric method CIE L*a*b*. 3. Summary of the Invention

[0011] Therefore, one object of the present invention is to overcome the aforementioned disadvantages by seeking to develop a transparent optical article, such as an ophthalmic lens, particularly a spectacle lens, comprising a substrate of a mineral or organic material, the substrate including at least one anti-reflective coating (AR coating). This anti-reflective coating, which has very good anti-reflective properties in the visible light region, also has a customized transmission tint, without compromising its economic and / or industrial feasibility of manufacture.

[0012] Therefore, the present invention relates to an optical article comprising a transparent substrate having a front main surface and a rear main surface, at least one of these main surfaces being coated with a multilayer antireflective coating, the multilayer antireflective coating comprising: at least one low refractive index layer (LI) having a refractive index less than 1.55 at 550 nm; at least one high refractive index layer (HI) having a refractive index greater than or equal to 1.55 at 550 nm; and at least one encapsulating metal film (EMF), the encapsulating metal film comprising metal island layers (MIL) encapsulated between the first layer (L1) and the second layer (L2), the first layer (L1) and the second layer (L2) being composed of the same or different dielectric materials.

[0013] Its features are,

[0014] - The first layer (L1) has a refractive index of less than 1.55 at 550 nm and a physical thickness equal to or greater than 10 nm.

[0015] - The metal island layer (MIL) exhibits a plasma effect and has an effective thickness ranging from 0.2 nm to 4 nm, preferably from 0.5 nm to 4 nm.

[0016] - The physical thickness of the second layer (L2) is equal to or greater than 10 nm.

[0017] The multilayer antireflective coating has an average light reflectance coefficient R in the visible light region on the front and / or back of the optical article. v The average light reflectance coefficient is equal to or less than 2.5% for an incident angle of at least less than 35°, preferably for an incident angle of 15° or 0°, and the light absorption of the AR stack is mainly due to the MIL layer.

[0018] Therefore, the optical article according to the present invention includes a high-efficiency anti-reflective (AR) coating that is capable of separating complementary colors in reflection and transmission. Furthermore, as shown in the following examples, the anti-reflective coating of the present invention is capable of reducing yellowness in transmission. 4. Description of the attached drawings

[0019] The invention will be described in more detail with reference to the accompanying drawings, in which:

[0020] - Figure 1 TEM images of gold films on Si3N4 films (coated with SiO2 passivation layers of effective thicknesses of a) 0.5 nm, b) 1.2 nm, and c) 1.7 nm deposited at room temperature are shown.

[0021] - Figure 2 This is a schematic diagram of an anti-reflective coating including an encapsulating metal layer according to an embodiment of the present invention. 5. Detailed Implementation

[0022] A°) definition

[0023] The terms “comprise” (and any of its grammatical variations, such as “comprises” and “comprising”), “have” (and any of its grammatical variations, such as “has” and “having”), “contains” (and any of its grammatical variations, such as “contains” and “containing”), and “include” (and any of its grammatical variations, such as “includes” and “including”) are all open-ended linking verbs. They are used to indicate the presence of a feature, integer, step, or component or group thereof, but do not exclude the presence or inclusion of one or more other features, integers, steps, or components or groups thereof. Therefore, a method or a step in a method that “comprises,” “has,” “contains,” or “includes” one or more steps or elements possesses, but is not limited to, only possessing, those steps or elements.

[0024] Unless otherwise specified, all figures or expressions relating to quantities of ingredients, reaction conditions, etc., used herein should be understood to be modified by the term “about” in all cases.

[0025] Furthermore, unless otherwise specified, according to the present invention, the indication of a value range "X to Y" or "between X and Y" means that it includes the values ​​of both X and Y. Additionally, unless otherwise specified, for value ranges, the expressions "below X" or "above Y" do not include the values ​​of X or Y.

[0026] The terms “multilayer antireflective coating” or “AR coating” and “AR stack” have the same meaning.

[0027] In this application, when an optical article includes one or more coatings on its surface, the expression "depositing a layer or coating onto the article" is intended to refer to depositing a layer or coating onto the outer (exposed) surface of the outer coating of the article, that is, onto the coating that is furthest from the substrate.

[0028] A coating “on” or deposited on a substrate is defined as a coating that: (i) is positioned above the substrate, (ii) is not necessarily in contact with the substrate, that is, one or more intermediate coatings may be arranged between the substrate and the coating in question, and (iii) does not necessarily completely cover the substrate.

[0029] In a preferred embodiment, the coating on or deposited on the substrate is in direct contact with the substrate.

[0030] When “layer 1 is below layer 2”, it means that layer 2 is farther from the substrate than layer 1.

[0031] The outermost layer of a multilayer antireflective coating refers to the layer of the antireflective (AR) coating that is furthest from the substrate.

[0032] The innermost layer of a multilayer antireflective coating refers to the layer of the antireflective coating closest to the substrate.

[0033] The inner layer of a multilayer antireflective coating refers to any layer of the antireflective coating other than the outermost layer of the AR coating.

[0034] Furthermore, unless otherwise stated and except for the metal island layer (MIL), all thicknesses disclosed in this application refer to physical thicknesses.

[0035] Metal islands have an average physical height.

[0036] On the final AR stack, the average height of the metal islands can be determined by observing the cross-section of the stack (measured via TEM).

[0037] The effective thickness (ET) of a MIL is the mass equivalent thickness of the MIL, which is the thickness of a continuous film made of the same material as the individual islands having the same mass as the MIL, for the surface covered by the MIL.

[0038] Because the mass is distributed among the islands, therefore Island height It will be higher than ET.

[0039] The effective thickness can be calculated using the following formula:

[0040] Effective thickness = Surface area occupancy factor x Island height x Shape factor.

[0041] - The surface area occupancy factor is the total island projected area on the surface under consideration divided by the total surface under consideration.

[0042] - The shape factor depends on the exact shape of the island; for example, 0.66 for a hemispherical island and 1.00 for a cylindrical island.

[0043] - Surface coverage, island shape, and island height can be estimated by transmission electron microscopy examination of the cross-section and top surface of the MIL (obtained through statistical evaluation by measuring hundreds of islands).

[0044] In fact, with these characteristics, the total volume of the material can be calculated, and thus the effective thickness of the MIL can be calculated.

[0045] When the MIL is included in a stack, the layers above and below the MIL can be etched using a focused ion beam to measure the total island projected area on the surface under consideration.

[0046] Unless otherwise specified, the refractive index mentioned in this application is expressed at 25°C and 550 nm wavelength.

[0047] In this application, when the refractive index of the antireflective coating layer is greater than or equal to 1.55, preferably greater than or equal to 1.6, even more preferably greater than or equal to 1.90 (e.g., 1.95), even more preferably greater than or equal to 2.00 (e.g., 2.14), it is referred to as a high refractive index layer (HI).

[0048] When the refractive index of the antireflective coating layer is less than 1.55, preferably less than or equal to 1.50, and more preferably less than or equal to 1.48, it is called a low refractive index layer (LI). The LI layer preferably has a refractive index greater than 1.1.

[0049] As used herein, and except for the metal island layer (MIL), a layer of antireflective coating is defined as having a thickness greater than or equal to 1 nm. Therefore, when counting the number of layers in an antireflective coating, any layer with a thickness less than 1 nm will not be considered. Sublayers, as described below, will also not be considered when counting the number of layers in an antireflective coating.

[0050] The multilayer antireflective coating according to the invention can be formed on at least one of the main surfaces of a bare substrate (i.e., an uncoated substrate) or on at least one of the main surfaces of a substrate that has been coated with one or more functional coatings (such as an anti-abrasion coating).

[0051] As used herein, the rear (or inner, concave, or CC) surface of the substrate is intended to refer to the surface closest to the wearer's eyes when the article is in use. It is typically concave. Conversely, the front (or convex, or CX) surface of the substrate is the surface furthest from the wearer's eyes when the article is in use. It is typically convex.

[0052] Furthermore, as used herein, "transparent substrate" should be understood as transparent when no significant loss of contrast is perceived when viewing an image through the substrate, i.e., when obtaining an image formed through the substrate without adversely affecting the quality of the image.

[0053] According to the present invention, the "angle of incidence (symbol θ)" is the angle formed by the light ray incident on the surface of an ophthalmic lens and the normal to the surface at the point of incidence. The light ray is, for example, a light-emitting source, such as those used in international colorimetric methods (CIE L). * a * b * The standard light source D65 is defined in (1976). Generally, the angle of incidence varies from 0° (normal incidence) to 90° (grazing incidence). The general range of the angle of incidence is 0° to 75°.

[0054] The optical products of this invention are compliant with the international colorimetric system CIE L. * a* b * The colorimetric coefficients (e.g., chromaticity C) in (1976) * The hue ("h") is calculated between 380nm and 780nm, taking into account the standard light source D65 and the observer (angle 10°). The observer is as per the CIE L international colorimetric system. * a * b * The "standard observer" as defined in CIE L. In fact, in CIE L. * a * b * In space, it can represent not only the overall change in color, but also the change in relation to the parameter L. * a * and b * One or more related changes in L. This can be used to define new parameters and associate them with visual attributes. Clarity related to luminosity is directly determined by L. * The value represents chroma. Chroma: C* = (a*) 2 +b 2 ) 1 / 2 Hue angle: h = tg⁻¹(b* / a*) (expressed in degrees); related to hue.

[0055] Transmission coefficient τ in the visible light range V Also known as the relative transmittance in the visible light range, it should be understood as defined by the international standard (ISO 13666:1998 standard) and measured according to ISO 8980-3 standard. It is defined in the wavelength range of 380nm to 780nm.

[0056] In this specification, unless otherwise specified, transmittance / transmittance is measured at the center of an optical article with a thickness ranging from 0.7 mm to 2 mm, preferably from 0.8 mm to 1.5 mm, at an angle of incidence ranging from 0° to 15°, preferably 0° or 15°. As used herein, transmitted light refers to light that reaches the front main surface of the optical article and passes through the lens.

[0057] In this article, it is denoted as R. v "Light reflectance" is defined in ISO 13666:1998 and measured according to ISO 8980-4, which is the weighted average spectral reflectance over the entire visible spectrum from 380 nm to 780 nm. v It is typically measured for an angle of incidence of less than 17°, typically 15°, but can be evaluated for any angle of incidence.

[0058] B°) Optical Products

[0059] The optical article according to the present invention is a transparent optical article, preferably a lens or lens blank, more preferably an ophthalmic lens or lens blank. The optical article may be coated with the multilayer antireflective coating of the present invention on its convex main side (front side), concave main side (rear side), or both sides.

[0060] B1°) Substrate

[0061] Generally, the interference multilayer coating of the optical article according to the present invention can be an anti-reflective coating (hereinafter referred to as AR coating), which can be deposited on any substrate, preferably on an organic lens substrate, such as a thermoplastic or thermosetting plastic material.

[0062] Thermoplastics may be selected from, for example: polyamides; polyimides; polysulfones; polycarbonates and their copolymers; poly(ethylene terephthalate) and polymethyl methacrylate (PMMA).

[0063] Thermosetting materials can be selected from, for example: cyclic olefin copolymers, such as ethylene / norbornene or ethylene / cyclopentadiene copolymers; homopolymers and copolymers of allyl carbonates of linear or branched aliphatic or aromatic polyols, such as homopolymers of diethylene glycol bis(allyl carbonate) (CR). (); homopolymers and copolymers of (meth)acrylic acid and its esters that may be derived from bisphenol A; polymers and copolymers of thio(meth)acrylic acid and its esters, polymers and copolymers of allyl esters that may be derived from bisphenol A or phthalic acid and allyl aromatic hydrocarbons such as styrene, polymers and copolymers of urethane and thiourethane, polymers and copolymers of epoxy resins, and polymers and copolymers of sulfides, disulfides and cyclic sulfides, and combinations thereof.

[0064] As used herein, (co)polymer is intended to mean copolymer or polymer. As used herein, (meth)acrylate is intended to mean acrylate or methacrylate. As used herein, polycarbonate (PC) is intended to mean homopolymer or copolymer and block copolymer.

[0065] Preferred diethylene glycol bis(allyl carbonate) (CR) Homopolymers, allyl and (meth)acrylic acid copolymers with a refractive index between 1.54 and 1.58, polymers and copolymers of thiourethane, and polycarbonate are preferred.

[0066] Prior to depositing the antireflective coating of the present invention, the substrate may be coated with one or more functional coatings. These functional coatings, commonly used in optical devices, may be, but are not limited to, impact-resistant primers, abrasion-resistant coatings and / or scratch-resistant coatings, polarizing coatings, photochromic coatings, or coloring coatings. Hereinafter, substrate refers to a bare substrate or such coated substrate.

[0067] Preferably, the substrate and the optional abrasion-resistant and / or scratch-resistant coatings typically applied to the substrate have similar / close refractive indices to avoid streaks or appearance defects.

[0068] Prior to depositing the antireflective coating, the surface of the substrate is typically subjected to a physical or chemical surface activation treatment to enhance the adhesion of the antireflective coating. This pretreatment is usually performed under vacuum. Such pretreatment can be bombardment with high-energy and / or reactive components, such as ion beams (“ion pre-cleaning” or “IPC”) or electron beams, corona discharge treatment, ion spallation treatment, ultraviolet radiation treatment, or vacuum plasma-mediated treatment (typically using oxygen or argon plasma). This pretreatment can also be an acidic or alkaline treatment and / or a solvent-based treatment (water, hydrogen peroxide, or any organic solvent).

[0069] B2° Multi-layer Anti-reflective Coating

[0070] The multilayer antireflective coating of the present invention will now be described below.

[0071] As previously stated, at least one of the main surfaces (front or rear main surface) of the transparent substrate is coated with a multilayer antireflective coating (hereinafter referred to as AR coating) according to the present invention.

[0072] The AR coating comprises: at least one low refractive index layer (LI) having a refractive index of less than 1.55 at 550 nm, hereinafter referred to as the first LI layer; at least one high refractive index layer (HI) having a refractive index of greater than or equal to 1.55 at 550 nm, hereinafter referred to as the first HI layer; and at least one encapsulating metal film (EMF), the encapsulating metal film comprising a metal island layer (MIL) encapsulated between the first layer (L1) and the second layer (L2), wherein the first layer (L1) and the second layer (L2) are both composed of the same or different dielectric materials, characterized in that:

[0073] - The first layer (L1) is a second L1 layer with a refractive index of less than 1.55 at 550 nm and a physical thickness equal to or greater than 10 nm.

[0074] - The metal island layer (MIL) exhibits a plasma effect and has an effective thickness ranging from 0.2 nm to 4 nm, preferably from 0.5 nm to 4 nm.

[0075] - The physical thickness of the second layer (L2) is equal to or greater than 10 nm.

[0076] The multilayer antireflective coating has an average light reflectance coefficient R in the visible light region on the front and / or back of the optical article. vThe average light reflectance coefficient is equal to or less than 2.5% for an incident angle of at least less than 35°, preferably for an incident angle of 0°, and more preferably for an incident angle of less than 15°.

[0077] The light absorption of the anti-reflective coating is primarily due to the MIL layer. This means that at least 50% of the transmittance (Tv) reduction caused by the anti-reflective coating is attributable to the MIL layer. The transmittance loss caused by the anti-reflective coating can be assessed by comparison with an optical product without the anti-reflective coating.

[0078] For example, in the initial growth stages of noble metal films such as gold, silver, and copper (Volmer-Weber growth), islands often form on the dielectric surface. The size of these islands restricts the free electrons of the metal (the mean free path of the electrons is greater than the size of the island), causing them to accumulate at the metal / dielectric interface (here, L1 and L2) when exposed to electromagnetic waves, thus forming a dipole. This dipole resonates at a specific frequency (and therefore wavelength), defined as the plasmon resonance frequency (wavelength). Typically, metal island layers (MILs) with an effective thickness of a few nanometers produce high absorption in the visible spectrum, which causes color formation.

[0079] In particular, MIL supports the excitation of localized surface plasmon resonances (LSPRs) in the visible spectrum. Indeed, at the wavelength corresponding to the resonance frequency, the coupling between the incident light and the electron cloud is particularly strong. This induces strong localized light absorption, which then transforms into collective electron oscillations (called localized surface plasmon polaritons – LSPs). Plasmon polaritons can also be re-emitted, causing scattering.

[0080] Here, the applicant has developed a MIL with an effective thickness of a few nanometers that produces selective light absorption in the visible spectrum, thereby generating custom colors.

[0081] In particular, the encapsulation metal film (EMF) of the present invention is capable of absorbing a portion of light within a selected wavelength range of the visible spectrum. Specifically, the absorption of the AR coating of the present invention is primarily due to the encapsulation metal film EMF, and more particularly due to the presence of the discontinuous metal island layers MIL.

[0082] For example, at least 50% or 85%, preferably at least 90%, typically at least 95% (e.g., 98%) of the light absorption in the visible light region by the AR coating (or alternatively, a decrease in transmittance Tv) is due to the EMF or MIL.

[0083] In practice, according to an embodiment of the invention, the AR coating does not include a continuous metal layer. According to another embodiment of the invention, the AR coating does not include another encapsulating metal film (EMF) having metal island layers.

[0084] In addition, to meet the limitations in the ophthalmic field (such as the requirement for high TV), the applicant has developed an encapsulated metal film EMF that includes MIL, which helps reduce reflection in the visible light region, but more importantly, it is able to correct the color of the resulting AR coating in transmission.

[0085] Furthermore, the applicant has discovered that the MILs of the present invention have optical constants that are significantly different from their successive counterparts (e.g., continuous metal layers). In particular, contrary to the use of these continuous metal layers to achieve AR coatings, it has been shown that the selective light absorption of the MILs of the present invention can maintain a high transmittance value.

[0086] In fact, as shown in the example below, the antireflective coating according to the present invention can achieve a low reflectivity (R0 at an incident angle of 15°). v ≤0.8%), high transmittance (Tv≥83% at a 15° incident angle), and at the same time, the custom-designed transmittance color has very little or no yellowness (relatively low b* value).

[0087] In particular, the customized transmission color of the AR coating of the present invention can be controlled according to the characteristics of the encapsulated metal film EML. In fact, the applicant has discovered that the colorimetric parameters of the transmitted color of the AR coating of the present invention, such as hue "h", color saturation (chromaticity C*) and brightness, can be changed / controlled by plasma resonance characteristics and therefore by the design of the EML according to the present invention.

[0088] As mentioned above and as Figure 2 As shown, the EML according to the present invention comprises, and preferably consists of, a metal island layer (MIL) encapsulated between a first layer (L1) and a second layer (L2), both of which are composed of at least one dielectric material.

[0089] like Figure 2 As shown, these islands are covered by layer L1, with the top L2 layer touching the bottom L1 layer. Of course, if L1 is very thin and depends on the height of the islands, the L1 layer will not be as... Figure 2 It is as flat as shown and will follow the shape of the island.

[0090] Preferably, the metal of the metal island layer (MIL) is selected from silver (Ag), gold (Au), or copper (Cu) or a mixture thereof.

[0091] According to the present invention, the metal island layer (MIL) has an effective thickness (ET) as defined above, wherein the effective thickness ranges from 0.2 nm to 4 nm, preferably from 0.5 nm to 4 nm. Typically, the effective thickness of the metal island layer (MIL) ranges from 0.3 nm to 3 nm, preferably from 1 nm to 2 nm.

[0092] Here, the effective thickness range of "0.2nm to 4nm" includes the following values ​​and / or any intervals (including limits) between these values: 0.2; 0.3; 0.4; 0.5; 0.6; 0.7; 0.8; 0.9; 0.10; 0.11; 0.12; 0.15; 0.20; 0.25; 0.30; 0.35; 0.40; 0.45; 0.50; 0.55; 0.60; 0.65; 0.70; 0.75; 0.80; 0.90; 0.95; 1.0; 1.05; 1 1.10; 1.15; 1.20; 1.25; 1.30; 1.35; 1.40; 1.45; 1.50; 1.55; 1.60; 1.65; 1.70; 1.75; 1.80; 1.85; 1.90; 2.00; 2.10; 1.20; 2.30; 2.40; 2; 50; 2.60; 2.70; 2.80; 2.90; 3.00; 3.10; 3.20; 3.40; 3.50; 3.60; 3.70; 3.80; 3.90; 4.00.

[0093] For example, the effective thickness can be calculated as follows:

[0094] If the island has such Figure 1 The hemispherical shape shown in figure a, with a surface occupancy factor of 17% and an island height of 4.4 nm (and therefore a diameter of 8.8 nm), yielded:

[0095] ET = 2 / 3 × surface area occupancy factor × island height.

[0096] ET = 2 / 3 × 0.17 × 4.4 = 0.5 nm

[0097] Furthermore, for Figure 1 The island shown in c, with a measured island height of 4.6 nm and a surface occupancy factor of 55%, thus yielded ET = 1.7 nm.

[0098] According to the features of the invention and as Figure 1 or Figure 2 As shown, MIL is composed of or constituted by the aforementioned metal nanoislands having spherical, elliptical, or other shapes.

[0099] Preferably, the nanoislands have a uniform shape, especially a spherical shape (see...). Figure 1 ).

[0100] According to this embodiment, the size (or diameter) of the nanoisland ranges from 1 nm to 50 nm, preferably from 3 nm to 30 nm, and typically from 3 nm to 15 nm. In this document, "size" refers to the diameter of the nanoisland or the longest distance within the nanoisland.

[0101] In fact, nanoislands with a uniform spherical shape and small size distribution (e.g., less than 50 nm) can produce well-defined absorption peaks, especially for MILs with an effective thickness of 1.5 nm or less. Indeed, for MILs with a higher effective thickness (e.g., 2.3 nm), the absorption peaks in the visible light region are typically broader and redshifted due to the worm-like nature of the islands.

[0102] For example, the density of the nanoislands according to the present invention is typically determined by SEM or TEM imaging.

[0103] Furthermore, the surface area occupancy factor of this MIL is typically in the range of 10% to 98%, preferably in the range of 17% to 75%, preferably in the range of 53% to 70%, and typically in the range of 63% to 70%.

[0104] Here, the MIL range occupancy factor of "10% to 83" includes the following values ​​and / or any intervals (including limits) between these values: 10; 11; 15; 18; 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50; 51, 52, 53, 54, 55, 56, 57, 58, 59; 60; 61; 62; 63; 64; 65; 66; 67; 68; 69; 70; 71; 72; 73; 74; 75%.

[0105] Preferably, this MIL has a low surface area occupancy factor (or coverage) and is in the range of 10% to 80%, preferably in the range of 15% to 70%. In fact, the applicant has found that a low surface area occupancy factor (or low coverage) can enhance the adhesion between layer L1 and layer L2.

[0106] According to the present invention, the “occupancy factor of MIL” refers to the proportion of the surface of the layer located directly below the MIL (here, usually L2 as described above) and covered by the MIL.

[0107] In addition, the applicant also found that the two layers L1 and L2 encapsulating the MIL have an impact on the local surface plasmon resonance of the MIL.

[0108] In particular, it has been shown that L1 and L2 should be thick enough to cover MIL and also limit the effect of additional dielectric layers (e.g., at least one first LI layer and at least one first HI layer) added below or above EML.

[0109] Thus, according to the present invention, the first layer (L1) is a second LI layer having a refractive index lower than 1.55 at 550 nm and having a physical thickness equal to or greater than 10 nm, while the physical thickness of the second layer (L2) is equal to or greater than 10 nm.

[0110] According to a feature of the present invention, the physical thickness of the first layer L1 ranges from 10 nm to 100 nm, preferably from 15 nm to 50 nm.

[0111] According to another feature of the present invention, the physical thickness of the second layer L2 ranges from 10 nm to 100 nm, preferably from 15 nm to 50 nm.

[0112] In particular, the physical thickness of layer L1 is similar to the physical thickness of layer L2.

[0113] Generally, the first layer, i.e., the LI layer (e.g., having a refractive index lower than 1.55 at 550 nm) contains one or more dielectric materials selected from the following: silicon oxide (SiO x , where 1.3 < x ≤ 2), MgF2, preferably silicon dioxide (SiO2).

[0114] The second layer L2 can be a LI layer or a HI layer. If the second layer L2 is a LI layer, it can contain one or more dielectric materials selected from the following: silicon oxide (SiO x , where 1.3 < x ≤ 2), MgF2, preferably silicon dioxide (SiO2), and if the second layer L2 is a HI layer, it can contain one or more dielectric materials selected from zirconium oxide (ZrO2), titanium dioxide (TiO2), or tantalum pentoxide (Ta2O5).

[0115] Generally, the encapsulation metal film EMF of the present invention includes, in a direction away from the transparent substrate, in the following order: the second layer (L2) / the metal island layer (MIL) / the first layer (L1). In fact, generally, the MIL is coated on the second layer L2.

[0116] In particular, according to the present invention, layers L1, MIL, and layer L2 are in direct contact. For example, the MIL is directly coated on the L2 layer and the L1 layer is coated on itself (encapsulation).

[0117] As mentioned above, in addition to the EML, that is, below or above the EML, the AR coating of the present invention further includes at least one LI layer, hereinafter referred to as the "first LI layer", and at least one HI layer, hereinafter referred to as the "first HI layer".

[0118] In fact, in addition to EML, the AR coating also includes at least one layer with a low refractive index (LI), preferably two layers, typically three layers, and at least one layer with a high refractive index (HI), preferably two layers, typically three layers. This is a simple stack because the total number of layers in the antireflective coating (without EML) is greater than or equal to 2, and typically less than or equal to 12.

[0119] (Besides the EML) the HI and LI layers do not necessarily have to alternate in the stack, but they may alternate according to one embodiment of the invention. Two HI layers (or more) may be deposited one above the other, and two LI layers (or more) may also be deposited one above the other. Typically, the HI and LI layers alternate in the stack of the AR coating according to the invention. In particular, the HI and LI layers alternate according to the AR coating stack and are placed below and / or above the EML.

[0120] According to the features of the present invention, the outermost layer of the AR coating is a first L1 layer. Typically, the physical thickness of the outermost layer is equal to or greater than 50 nm, preferably equal to or greater than 60 nm, and generally ranges from 60 nm to 150 nm.

[0121] According to another feature of the invention, the layer of the AR coating closest to the substrate is either the second layer (L2) of the encapsulating metal film (EMF) or the first HI layer.

[0122] According to a first embodiment of the present invention, the multilayer antireflective coating may include, along the direction away from the substrate, the multilayer antireflective coating.

[0123] - A first HI layer with a physical thickness of less than or equal to 30 nm, preferably ranging from 5 nm to 30 nm, and more preferably ranging from 5 nm to 11 nm;

[0124] - A Li layer with a physical thickness ranging from 30 nm to 60 nm, more preferably from 40 nm to 50 nm;

[0125] - An L2 layer with a physical thickness ranging from 10 nm to 30 nm, more preferably from 12 nm to 20 nm, and preferably a HI layer;

[0126] - MIL layers with an effective thickness ranging from 0.5 nm to 4 nm, more preferably from 0.5 nm to 2 nm;

[0127] - An L1 layer with a physical thickness ranging from 10 nm to 30 nm, more preferably from 10 nm to 20 nm;

[0128] - A HI layer with a physical thickness of less than or equal to 30 nm, preferably ranging from 5 nm to 30 nm, and more preferably ranging from 5 nm to 12 nm;

[0129] - A first LI layer with a physical thickness greater than 60 nm, ranging from 70 nm to 150 nm, more preferably from 75 nm to 90 nm, also known as the outermost LI layer.

[0130] According to a second embodiment of the present invention, the multilayer antireflective coating may include, along the direction away from the substrate, the multilayer antireflective coating.

[0131] - A first HI layer with a physical thickness of less than or equal to 50 nm, preferably ranging from 5 nm to 50 nm, and more preferably ranging from 20 nm to 30 nm;

[0132] -LI layers with a physical thickness ranging from 30nm to 70nm, more preferably from 40nm to 60nm;

[0133] - A HI layer with a physical thickness greater than or equal to 20 nm, preferably ranging from 30 nm to 60 nm, and more preferably ranging from 40 nm to 50 nm.

[0134] - An L2 layer, or LI layer, with a physical thickness ranging from 10 nm to 30 nm, more preferably from 12 nm to 20 nm;

[0135] - MIL layer with an effective thickness equivalent to 0.5 nm to 4 nm, more preferably 1 nm to 3 nm;

[0136] - An L1 layer with a physical thickness ranging from 10 nm to 30 nm, more preferably from 10 nm to 20 nm;

[0137] - A HI layer with a physical thickness of less than or equal to 30 nm, preferably ranging from 5 nm to 30 nm, and more preferably ranging from 5 nm to 18 nm;

[0138] - A first LI layer with a physical thickness greater than 40 nm, ranging from 40 nm to 150 nm, more preferably from 50 nm to 70 nm, also known as the outermost LI layer.

[0139] According to a third embodiment of the present invention, the multilayer antireflective coating may include, along the direction away from the substrate, the multilayer antireflective coating.

[0140] - A first HI layer with a physical thickness of less than or equal to 50 nm, preferably ranging from 5 nm to 50 nm, and more preferably ranging from 5 nm to 15 nm;

[0141] - An L2 layer, or LI layer, with a physical thickness ranging from 10 nm to 30 nm, more preferably from 12 nm to 20 nm;

[0142] - MIL layer with an effective thickness equivalent to 0.5 nm to 4 nm, more preferably 3 nm to 4 nm;

[0143] - An L1 layer (LI layer) with a physical thickness ranging from 10 nm to 30 nm, more preferably from 10 nm to 20 nm;

[0144] - A first LI layer with a physical thickness greater than 60 nm, ranging from 70 nm to 150 nm, more preferably from 75 nm to 90 nm, also known as the outermost LI layer.

[0145] Advantageously, at least one HI layer not included in the encapsulating metal film (EMF) comprises one or more metal oxides selected from: zirconium oxide (ZrO2), aluminum oxide (Al2O3), tantalum pentoxide (Ta2O5), praseodymium oxide (Pr2O3), praseodymium titanate (PrTiO3), lanthanum oxide (La2O3), yttrium oxide (Y2O3), niobium oxide (Nb2O5), titanium dioxide (TiO2), and mixtures thereof. Preferred materials include zirconium oxide (ZrO2) and tantalum pentoxide (Ta2O5). Optionally, the HI layer may further comprise silicon dioxide or other materials having a low refractive index, provided that they have a refractive index greater than or equal to 1.6 as indicated above.

[0146] Furthermore, preferably, it is also known that at least one LI layer not included in the encapsulating metal film (EMF) may include, but is not limited to, mixtures of MgF2, SiO2, silicon dioxide, and alumina, especially alumina-doped silicon dioxide (alumina helps increase the heat resistance of the antireflective coating), or mixtures thereof. The LI layer is preferably a layer comprising at least 80% by weight of silicon dioxide relative to the total weight of the layer, more preferably at least 90% by weight of silicon dioxide, and even more preferably a layer composed of a silicon dioxide layer (SiO2). Optionally, the LI layer may further comprise a material having a high or very high refractive index, provided that the resulting layer has a refractive index of less than 1.55.

[0147] When using a LI layer containing a mixture of SiO2 and Al2O3, it preferably contains 1% to 10% by weight, more preferably 1% to 8% by weight, and even more preferably 1% to 5% by weight of Al2O3 relative to the total weight of SiO2+Al2O3 in such a layer.

[0148] For example, SiO2 doped with 4% or less Al2O3, or SiO2 doped with 8% Al2O3, can be used. Commercially available SiO2 / Al2O3 mixtures can be used, such as those sold by Umicore Materials AG. (At 550 nm, the refractive index n = 1.48-1.50), or products sold by Merck KGaA. (At 500 nm, the refractive index n = 1.48).

[0149] Typically, the total number of layers in an AR coating (with EML) is greater than or equal to 5, more preferably greater than or equal to 6, typically greater than or equal to 7, and especially greater than or equal to 8.

[0150] In particular, the total number of layers in the antireflective coating (with EML) is less than or equal to 11 layers, more preferably less than or equal to 10 layers, even more preferably less than or equal to 9 layers, and most preferably equal to or less than 8 layers.

[0151] Preferably, the total thickness of the antireflective coating (with EML) is less than or equal to 450 nm, more preferably less than or equal to 350 nm, and even more preferably less than or equal to 250 nm. The total thickness of the antireflective coating is typically greater than 50 nm, preferably greater than or equal to 100 nm. Generally, the physical thickness of the antireflective coating ranges from 100 nm to 250 nm.

[0152] As used herein, the range less than or equal to 450 nm includes the following values ​​and / or any range (including limits) between these values: 450; 440; 430; 420; 410; 400; 390; 380; 370; 360; 350; 340; 330; 320; 310; 300; 250; 230; 220; 210; 200; 190; 180; 170; 160; 150; 140; 130; 120; 110; 105; 100; 95; 90; 85; 80; 75; 70; 65; 60; 55; 50, etc.

[0153] According to another feature of the invention, the AR coating may include an antistatic layer (also known as a conductive layer).

[0154] In fact, the ophthalmic lens of the present invention can be made antistatic by incorporating at least one conductive layer into a stack present on the surface of the article, that is, by not retaining and / or forming a large amount of static charge.

[0155] The ability of a material to dissipate static charge acquired after rubbing it with a cloth or using any other procedure that generates static charge (charge applied by corona, etc.) can be quantified by measuring the time required for the charge to dissipate. Thus, antistatic materials have discharge times of approximately several hundred milliseconds, preferably 500 ms or less, while electrostatic glass has times of approximately tens of seconds. In this application, the discharge time is measured according to the method disclosed in French application FR 2 943 798.

[0156] As used herein, "conductive layer" or "antistatic layer" is intended to refer to a layer that, due to its presence on the surface of a non-antistatic substrate (i.e., having a discharge time of more than 500 ms), is capable of having a discharge time of 500 ms or less after an electrostatic charge has been applied to its surface.

[0157] The conductive layer can be located at different positions within the stack, typically within or in contact with the antireflective coating, provided its antireflective properties are not affected. Preferably, the conductive layer is located between two layers of the antireflective coating and / or adjacent to a high-refractive-index layer of such an antireflective coating. Preferably, the conductive layer is located directly beneath a low-refractive-index layer of the antireflective coating, most preferably as the penultimate layer of the antireflective coating (directly beneath the silica-based outer layer of the antireflective coating): for example, “LI outer layer” or “LI outermost layer”.

[0158] The conductive layer should be thin enough not to alter the transparency of the antireflective coating. The conductive layer is preferably made of a conductive and highly transparent material (typically an optionally doped metal oxide). In this case, the thickness of the conductive layer preferably varies from 1 nm to 15 nm, more preferably from 1 nm to 10 nm. Preferably, the conductive layer comprises an optionally doped metal oxide selected from indium, tin, zinc oxides, and mixtures thereof. Indium tin oxide (In₂O₃:Sn, tin-doped indium oxide), aluminum-doped zinc oxide (ZnO:Al), indium oxide (In₂O₃), and tin oxide (SnO₂) are preferred. In the most preferred embodiment, the conductive and light-transparent layer is an indium tin oxide layer, referred to as an ITO layer or tin oxide layer.

[0159] Typically, conductive layers, due to their small thickness, help (but in a limited way) achieve anti-reflective properties within the stack and typically represent high-refractive-index layers in such anti-reflective coatings. This is the case for layers made of conductive and highly transparent materials (such as ITO layers).

[0160] Preferably, the antireflective coating does not include any indium oxide-based layer with a thickness greater than or equal to 20 nm, more preferably greater than 15 nm. When multiple indium oxide-based layers are present in the antireflective coating, their total thickness is preferably less than 20 nm, more preferably less than 15 nm. As used herein, an indium oxide-based layer is intended to refer to a layer containing at least 50% by weight of indium oxide relative to the total weight of the layer.

[0161] According to a preferred embodiment, the antireflective coating does not include any layer containing indium oxide, tin oxide, or zinc oxide with a thickness greater than or equal to 20 nm, preferably greater than 15 nm. When multiple layers containing indium oxide, tin oxide, or zinc oxide are present in the antireflective coating, their total thickness is preferably less than 20 nm, more preferably less than 15 nm.

[0162] Therefore, the present invention provides an improved antireflective coating comprising a relatively thin stack of layers, the thickness and materials of which have been selected to achieve satisfactory antireflective properties and customized transmission color.

[0163] Preferably, the residual reflected light from the multilayer antireflective coating has a chromaticity C* as defined in the CIE L*a*b* colorimetric standard and for an incident angle (θ) of 30° or 15° equal to or greater than 9, preferably equal to or greater than 14.

[0164] Typically, optical products are ophthalmic lenses, such as spectacle lenses. The anti-reflective coatings on the front and back can preferably be different.

[0165] In embodiments of the invention, the rear and front main surfaces of the optical article are coated with the same or different multilayer anti-reflective coatings according to the invention. According to another embodiment, the front of the ophthalmic lens of the invention is coated with the aforementioned anti-reflective coating. In yet another embodiment, the rear of the ophthalmic lens of the invention is coated with a conventional anti-reflective coating.

[0166] In one embodiment, the ophthalmic lens according to the invention does not absorb much in the visible light, which means that, in the context of this application, its transmittance coefficient τV in the visible light range, also known as the relative transmittance coefficient in the visible light range, is greater than 75%, more preferably greater than 80%, and even more preferably greater than 85%.

[0167] B3°) sublayer

[0168] In one embodiment of the invention, the anti-reflective coating may be deposited on a sublayer. It should be noted that such a sublayer is not considered an anti-reflective coating.

[0169] As used herein, a sublayer or adhesive layer is intended to refer to a relatively thick coating used to improve the mechanical properties of the coating (such as abrasion resistance and / or scratch resistance) and / or to enhance its adhesion to the substrate or underlying coating.

[0170] Due to its relatively high thickness, the sublayer typically does not participate in anti-reflective optical activity, especially when the refractive index of the sublayer is close to that of the underlying substrate (usually an anti-wear and anti-scratch coating or a bare substrate).

[0171] The thickness of the sublayer should be sufficient to improve the abrasion resistance of the anti-reflective coating, but preferably not to the point of causing light absorption, which, depending on the properties of the sublayer, could significantly reduce the relative transmittance τ. v The thickness of this sublayer is typically less than 300 nm, more preferably less than 200 nm, and typically greater than 90 nm, more preferably greater than 100 nm.

[0172] The sublayer is preferably a SiO2-based layer, comprising preferably at least 80% by weight of silicon dioxide, more preferably at least 90% by weight of silicon dioxide, and even more preferably composed of a silicon dioxide layer relative to the total weight of the layer. The thickness of such a silicon dioxide-based layer is typically less than 600 nm, more preferably less than 500 nm, and typically greater than 90 nm, more preferably greater than 100 nm, and even more preferably greater than 150 nm.

[0173] In another embodiment, the SiO2-based layer is a silicon dioxide layer doped with aluminum oxide in the amount defined above, preferably consisting of an aluminum oxide-doped silicon dioxide layer.

[0174] In a specific embodiment, the sublayer consists of a SiO2 layer.

[0175] Single-layer sublayers are preferred. However, sublayers can be stacked (multi-layered), especially when the sublayer and the underlying substrate have significantly different refractive indices. This is particularly suitable when the underlying substrate has a high refractive index, i.e., a refractive index greater than or equal to 1.55, preferably greater than or equal to 1.57.

[0176] In this case, in addition to the 90-400 nm thick layer (referred to as the main layer), the sublayer may also include preferably up to three additional layers, more preferably up to two additional layers, which are inserted between the optionally coated substrate and this 90-400 nm thick layer (which is typically a silicon dioxide-based layer). These additional layers are preferably thin layers, and their function is to limit multiple reflections at the sublayer / underlying coating interface or at the sublayer / substrate interface (where appropriate).

[0177] In addition to the main layer, the multilayer sublayers preferably include layers with a high refractive index and a thickness of 80 nm or less, more preferably 50 nm or less, and even more preferably 30 nm or less. Such high-refractive-index layers directly contact the high-refractive-index substrate or the high-refractive-index lower coating (where appropriate). Of course, this embodiment can also be used even if the substrate (or lower coating) has a refractive index of less than 1.55.

[0178] Alternatively, in addition to the main layer and the aforementioned high-refractive-index layer, the sublayer also includes a layer made of a SiO2-based material (i.e., preferably containing at least 80% by weight silicon dioxide), having a refractive index less than or equal to 1.55, preferably less than or equal to 1.52, more preferably less than or equal to 1.50, and a thickness less than or equal to 80 nm, more preferably less than or equal to 50 nm, and even more preferably less than or equal to 30 nm, on which the aforementioned high-refractive-index layer is deposited. Typically, in this case, the sublayer comprises a 25 nm thick SiO2 layer, a 10 nm thick ZrO2 or Ta2O5 layer, and the sublayer main layer, deposited in this order on an optionally coated substrate.

[0179] According to an embodiment, the anti-reflective coating is not deposited on the aforementioned sublayer.

[0180] B4° process

[0181] Different layers (except MIL) of the antireflective coating, and optional sublayers, are preferably deposited under vacuum by vapor deposition according to any of the following methods: i) optionally ion beam assisted evaporation, ii) ion beam sputtering; iii) cathode sputtering; iv) plasma-assisted chemical vapor deposition. These different methods are described in the following references, “Thin Film Processes” and “Thin Film Processes II”, edited by Vossen & Kern, Academic Press, 1978 and 1991, respectively. Vacuum evaporation is particularly recommended.

[0182] Preferably, the deposition of each of these layers of the antireflective coating (except MIL) and optional sublayers is carried out by vacuum evaporation under classical conditions known to those skilled in the art, such as those described in EP 2122392, EP 2411850, or WO 2012076714.

[0183] The deposition process of EML will now be described.

[0184] In particular, the manufacturing of EML includes the following sequential steps.

[0185] - For example, depositing an L2 layer using the techniques described above;

[0186] - Deposition of the MIL layer; and

[0187] -For example, depositing layer L1 using the above-mentioned techniques

[0188] In particular, the deposition of the MIL layer can be accomplished through evaporation or sputtering.

[0189] As mentioned above, noble metals (Ag, Au, and Cu) typically exhibit 3D growth patterns (island growth) on dielectric surfaces. The energy of the incoming atoms, the surface temperature of the substrate, and the deposition rate (power and pressure) are all parameters that influence the growth kinetics by affecting the diffusion length of the atoms. This length determines several properties, such as the density of the islands (the average distance between each island), their size, and their shape.

[0190] Therefore, the surface temperature of the substrate is preferably between 20°C and 300°C, and particularly preferably between 20°C and 100°C. Indeed, during room temperature deposition, when two islands meet, low surface fluidity leads to incomplete coalescence, resulting in an elliptical shape. Deposition at higher temperatures or after subsequent annealing helps the islands recrystallize, thus achieving complete coalescence. Therefore, it has been shown that increasing surface heating during deposition helps promote the formation of MILs with the desired plasmonic properties (strong and narrow light absorption).

[0191] Polymer substrates typically cannot withstand temperatures above 120°C.

[0192] In fact, the size and density of the islands obtained through deposition techniques such as magnetron sputtering are closely related. Indeed, according to a simple growth kinetic model, based on N∝(F / D0)... 1 / 3 The density N of the island is related to the incoming vapor flux F and the diffusion length D0, where the diffusion length D0 depends on the surface temperature of the substrate.

[0193] The longer diffusion length D0 results in a lower density of islands for a given flux. This allows islands to reach a larger size before membrane penetration, compared to membranes deposited at lower temperatures or higher deposition rates.

[0194] In short, these two depositional parameters are preferred for achieving the desired density / island size.

[0195] B5°) Other functional layers

[0196] Typically, the front and / or rear main surfaces of the substrate on which a multilayer interference coating is deposited are coated with an impact-resistant primer layer, an abrasion-resistant coating and / or an anti-scratch coating, or an impact-resistant primer layer coated with an abrasion-resistant coating and / or an anti-scratch coating.

[0197] The anti-reflective coating of the present invention is preferably deposited on an abrasion-resistant coating and / or a scratch-resistant coating. The abrasion-resistant coating and / or a scratch-resistant coating can be any layer conventionally used as an abrasion-resistant coating and / or a scratch-resistant coating in the field of ophthalmic lenses.

[0198] Abrasion-resistant and / or scratch-resistant coatings are preferably hard coatings based on poly(meth)acrylate or silane, which typically include one or more mineral fillers designed to increase the hardness and / or refractive index of the coating once cured.

[0199] Hard wear-resistant coatings and / or scratch-resistant coatings are preferably prepared from a composition comprising at least one alkoxysilane and / or its hydrolysis product, which is obtained, for example, by hydrolysis with hydrochloric acid solution and optional condensation and / or curing catalyst.

[0200] Suitable coatings recommended for this invention include coatings based on epoxy silane hydrolysis products, such as those described in patents FR2 702 486 (EP 0 614 957), US 4 211 823, and US 5 015 523.

[0201] Abrasion-resistant and / or scratch-resistant coating compositions can be deposited onto the main surface of a substrate by dip coating or spin coating. They are then cured by a suitable method (preferably using heat or ultraviolet radiation).

[0202] The thickness of the abrasion-resistant coating and / or scratch-resistant coating typically varies from 2 μm to 10 μm, preferably from 3 μm to 5 μm.

[0203] Prior to depositing abrasion-resistant and / or scratch-resistant coatings, a primer coating can be applied to the substrate to improve the impact resistance and / or adhesion of subsequent layers in the final product. This coating can be any impact-resistant primer layer commonly used in articles made of transparent polymer materials, such as ophthalmic lenses.

[0204] Preferred primer compositions are polyurethane-based compositions and latex-based compositions, particularly polyurethane-type latexes that optionally contain polyester units.

[0205] Such a primer composition can be deposited on the surface of the article by dip coating or spin coating, and then dried at a temperature of at least 70°C and up to 100°C, preferably about 90°C, for a period of time ranging from 2 minutes to 2 hours, typically about 15 minutes, to form a primer layer with a cured thickness of 0.2 μm to 2.5 μm, preferably 0.5 μm to 1.5 μm.

[0206] The ophthalmic lens according to the invention may further include a coating formed on the antireflective coating and capable of altering its surface properties, such as a hydrophobic coating and / or an oleophobic coating (anti-fouling surface coating). These coatings are preferably deposited on the outer layer of the antireflective coating. Generally, the thickness of these coatings is less than or equal to 10 nm, preferably ranging from 1 nm to 10 nm, more preferably from 1 nm to 5 nm.

[0207] Instead of hydrophobic coatings, hydrophilic coatings that provide anti-fogging properties, or anti-fogging precursor coatings that provide anti-fogging properties when associated with a surfactant, can be used. An example of such an anti-fogging precursor coating is described in patent application WO 2011 / 080472.

[0208] Typically, the ophthalmic lens according to the invention comprises a substrate on the back of which are sequentially coated with an impact-resistant primer layer, an abrasion-resistant layer and / or a scratch-resistant layer, an anti-UV, an anti-reflective coating, and a hydrophobic and / or oleophobic coating, or a hydrophilic coating providing anti-fogging properties, or an anti-fogging precursor coating.

[0209] The front surface of the substrate of the ophthalmic lens may be sequentially coated with an impact-resistant primer layer, an abrasion-resistant layer and / or a scratch-resistant layer, an anti-reflective coating according to the present invention, and a hydrophobic coating and / or an oleophobic coating.

[0210] The ophthalmic lens according to the present invention is preferably a spectacle lens, or a spectacle lens blank. The lens may be a polarizing lens, a photochromic lens, or a sunglass lens, and may be tinted or untinted, and may be corrective or uncorrective.

[0211] The following examples illustrate the invention in a more detailed but non-limiting manner.

[0212] 6. Example

[0213] A) General Procedure

[0214] The optical article according to the present invention comprises an optical article having a diameter of 65 mm and a refractive index of 1.50 (Essilor Corporation). The lens substrate has a center thickness of -2.00 diopter and 1.2 mm, and is coated on its front and back, followed by an anti-abrasion coating and a scratch-resistant coating.

[0215] Example 3 of patent EP 0 614 957 discloses an anti-wear coating and a scratch-resistant coating (refractive index equal to 1.47 and thickness of 3.5 μm) made of colloidal silica and aluminum acetylacetonate, based on hydrolysis products composed of GLYMO and DMDES, deposited on a substrate.

[0216] The wear-resistant and scratch-resistant coating can be obtained by depositing and curing a composition comprising, by weight, 224 parts of GLYMO, 80.5 parts of HCl 0.1N, 120 parts of DMDES, 718 parts of colloidal silica in methanol (30% by weight), 15 parts of aluminum acetylacetonate, and 44 parts of ethyl cellosolve. The composition also contains 0.1% by weight of FLUORAD surfactant manufactured by 3M. TM FC-

[0217] The aforementioned abrasion and scratch resistant coating has a refractive index of about 1.5 (HC1.5 hereinafter) and is used on a substrate having a refractive index of 1.5.

[0218] Anti-reflective coating layers (except MIL) can be deposited on the front of the test lens without heating the substrate via vacuum evaporation (evaporation source: electron gun).

[0219] The deposition framework is typically a Leybold 1104 machine equipped with an electron gun (ESV14 (8kV)) for evaporating oxides and an ion gun (Commonwealth Mark II) for the initial stage of preparing the substrate surface using argon ions (IPC).

[0220] Typical EMF deposition process:

[0221] An EMF (L2 / MIL / L1) stack was deposited on the substrate, ultrasonically cleaned with an alkaline solution, then immersed in isopropanol, rinsed with distilled water, and finally dried with nitrogen. Prior to deposition, the surface was also exposed to an argon / oxygen plasma (flow ratio 2:1) at an RF bias of -100 for 5 minutes. All depositions were performed using an RF power supply with a base pressure typically of 2 × 10⁻⁶. -6 MIL was deposited by sputtering from a 5 cm gold target (99.99%) in an Ar (99.999%) atmosphere at a pressure of 6 mTorr and a power of 25 W (deposition rate approximately...). (Verified for each experiment).

[0222] For example, layer L1 is a gas containing atmospheric argon and oxygen (99.999%) (5:1 flow ratio) at a pressure of 5 millitor. The SiO2 layer was deposited from the SiO2 target (99.995%) at an RF power of 150W, while the L2 layer was deposited through... A titanium dioxide (TiO2) layer is deposited from a titanium target (99.99%) by reactive sputtering. The effective thickness of the MIL is controlled by a quartz crystal microbalance (QCM).

[0223] For Examples 2 and 3, both L1 and L2 layers are SiO2 layers deposited as described above.

[0224] The effective thickness of the MIL, as described above, was determined by a combination of spectrophotometry—transmission and reflection (Cary 7000 spectrophotometer with universal measurement accessories) and elliptic polarization spectroscopy (JA Woollam RC2-XI)—using a non-in-situ optical characterization calibrated QCM with a thicker continuous gold film. The optical properties of the resulting EMF were established using the same optical characterization equipment.

[0225] The optical parameters Rv, C*, and h° are determined in reflection at an incident angle of 15°, while the optical parameters a*, b*, and Tv are determined in transmission at an incident angle of 0°.

[0226] B) Test Program

[0227] The method for manufacturing optical articles includes the steps of introducing a substrate coated with an anti-abrasion coating and a scratch-resistant coating into a vacuum deposition chamber, evacuating the chamber until a high vacuum is achieved, activating the substrate by an argon ion beam (anodine current: 1A, anodine voltage: 100V, neutralization current: 130mA), turning off the ion irradiation, forming various layers of anti-reflective coating by successive evaporation on the substrate (as described above), and a final ventilation step.

[0228] Traditional AR coatings have been deposited (vacuum evaporation) as described above.

[0229] C) Result

[0230] C1. Case Study of Orange Anti-reflective Coating (Example 1)

[0231] Example 1 is compared with Comparative Example 1, which consists of pure SiO2 / ZrO2 (transparent dielectric material). Both stacks exhibit the same colorimetric properties (Rv, C*, and h°) in reflection:

[0232]

[0233]

[0234] Table 1

[0235] Therefore, for the same reflected color, the lens 1 according to the invention can achieve a more pronounced transmitted color. Thus, the transmitted color has been separated from the reflected color.

[0236] C2. Case Study of Green Anti-Reflective Coating (Example 2)

[0237] Example 2 is compared with Comparative Example 2, which consists of pure SiO2 / ZrO2 (a transparent dielectric material). Both stacks exhibit the same colorimetric properties in reflection:

[0238]

[0239] Table 2

[0240] Therefore, for the same reflected color, the lens 2 according to the invention can achieve a more pronounced transmitted color. Thus, the transmitted color has been separated from the reflected color.

[0241] C3. Case Study of Blue Anti-reflective Coating (Example 3)

[0242] Example 3 is compared with Comparative Example 3 composed of pure SiO2 / ZrO2 (transparent dielectric material). Both stacks exhibit the same colorimetric properties in reflection:

[0243]

[0244] Table 3

[0245] Therefore, for the same reflected color, the lens 3 according to the invention can achieve a more pronounced transmitted color. Thus, the transmitted color has been separated from the reflected color.

Claims

1. An optical article comprising a transparent substrate having a front main surface and a rear main surface, wherein at least one of the main surfaces is coated with a multilayer antireflective coating, the multilayer antireflective coating comprising: The system comprises at least one low-refractive-index layer (LI) having a refractive index less than 1.55 at 550 nm, hereinafter referred to as the first LI layer; at least one high-refractive-index layer (HI) having a refractive index greater than or equal to 1.55 at 550 nm, hereinafter referred to as the first HI layer; and at least one encapsulating metal film (EMF), said encapsulating metal film comprising a metal island layer (MIL) encapsulated between the first layer (L1) and the second layer (L2), wherein the first layer (L1) and the second layer (L2) are both composed of the same or different dielectric materials. The multilayer anti-reflective coating imparts an average light reflectance coefficient R to the optical product in the visible light region. v The average light reflectance coefficient is equal to or less than 2.5% for an incident angle of at least 35°, and the light absorption of the anti-reflective coating is mainly caused by the MIL layer. Its features are: - The first layer (L1) is a second L1 layer having a refractive index of less than 1.55 at 550 nm and a physical thickness equal to or greater than 10 nm. - The metal island layer (MIL) exhibits a plasma effect and has an effective thickness ranging from 0.2 nm to 4 nm. - The physical thickness of the second layer (L2) is equal to or greater than 10 nm. Among them, the first layer (L1) comprises one or more dielectric materials selected from the following: silicon oxide (SiO x , where 1.3 < x ≤ 2), MgF2, and Among them, the second layer (L2) comprises one or more dielectric materials selected from the following: silicon oxide (SiO x , where 1.3 < x ≤ 2), zirconium oxide (ZrO2), titanium dioxide (TiO2), tantalum pentoxide (Ta2O5), The surface area occupancy factor of the metal island layer (MIL) is in the range of 53% to 83%.

2. The optical article according to claim 1, wherein, The metal island layer (MIL) has an effective thickness ranging from 0.5 nm to 4 nm.

3. The optical article according to claim 1 or 2, wherein, The encapsulation metal film comprises, in the following order along the direction away from the transparent substrate: the second layer (L2) / the metal island layer (MIL) / the first layer (L1).

4. The optical article according to claim 1, wherein, The first layer (L1) is composed of silicon dioxide (SiO2).

5. The optical article according to claim 1, wherein, The second layer (L2) is composed of silicon dioxide (SiO2).

6. The optical article according to claim 1 or 2, wherein, The physical thickness of the first layer (L1) ranges from 10 nm to 100 nm.

7. The optical article according to claim 6, wherein, The physical thickness of the first layer (L1) ranges from 15 nm to 50 nm.

8. The optical article according to claim 1 or 2, wherein, The physical thickness of the second layer (L2) ranges from 10 nm to 100 nm.

9. The optical article according to claim 8, wherein, The physical thickness of the second layer (L2) ranges from 15 nm to 50 nm.

10. The optical article according to claim 1 or 2, wherein, The metal island layer (MIL) is selected from silver (Ag), gold (Au), or copper (Cu) or mixtures thereof.

11. The optical article according to claim 1 or 2, wherein, The effective thickness of the metal island layer (MIL) ranges from 0.3 nm to 3 nm.

12. The optical article according to claim 11, wherein, The effective thickness of the metal island layer (MIL) ranges from 1 nm to 2 nm.

13. The optical article according to claim 1 or 2, wherein, The surface area occupancy factor of the metal island layer (MIL) is in the range of 63% to 83%.

14. The optical article according to claim 1 or 2, wherein, The outermost layer of the multilayer antireflective coating is the first LI layer.

15. The optical article according to claim 1 or 2, wherein, The layer of the multilayer antireflective coating closest to the substrate is either the second layer (L2) of the encapsulated metal film (EMF) or the first HI layer.

16. The optical article according to claim 1 or 2, wherein, The at least one first HI layer comprises one or more metal oxides or metal-like oxides selected from the following: zirconium oxide (ZrO2), titanium dioxide (TiO2), aluminum oxide (Al2O3), tantalum pentoxide (Ta2O5), neodymium oxide (Nd2O5), praseodymium oxide (Pr2O3), praseodymium titanate (PrTiO3), lanthanum oxide (La2O3), niobium oxide (Nb2O5), yttrium oxide (Y2O3), silicon dioxide (SiOx), and silicon nitride (Si3N4).

17. The optical article according to claim 16, wherein, The at least one first HI layer comprises one or more metal oxides selected from the following: zirconium oxide (ZrO2) and titanium dioxide (TiO2).

18. The optical article according to claim 1 or 2, wherein, The at least one first LI layer comprises one or more metal oxides or metal-like oxides selected from the following: SiO2, or a mixture of silicon dioxide and aluminum oxide.

19. The optical article according to claim 1 or 2, wherein, The at least one first L1 layer is composed of silicon dioxide (SiO2).

20. The optical article according to claim 1 or 2, wherein, The optical product has a transmittance (Tv) of more than 75% in the visible spectrum.

21. The optical article according to claim 20, wherein, The optical product has a transmittance (Tv) of over 80% in the visible spectrum.

22. The optical article according to claim 1 or 2, wherein, The rear and front surfaces of the optical article are coated with the same or different multilayer antireflective coatings as described in any one of claims 1 to 21.

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