Thermocurable epoxy composition and transparent thermocured coating with durable adhesion prepared therefrom

Abstract

This disclosure provides a thermally curable coating composition for an optical article. The coating composition comprises a polyfunctional epoxy monomer combined with a UV absorber. The inclusion of at least one polyfunctional epoxy monomer and at least one UV absorber provides an epoxy coating that exhibits excellent adhesion on various lens substrates.

Description

Technical Field

[0001] The present disclosure relates to a thermosettable epoxy coating composition having UV filtering and durable adhesion, a method for preparing a thermoset epoxy coating obtained therefrom, and an optical article having such a coating. Background Art

[0002] In the field of optical devices, an optical article can be coated with one or more coatings, such as impact-resistant, anti-abrasion / scratch-resistant, and / or anti-reflective coatings, in order to impart various mechanical and / or optical properties to the article.

[0003] In addition to the above functional coatings, an optical article can also be given a light filtering function to prevent or limit the transmission of light of a specific wavelength. The addition of the filtering function should be carried out without significantly changing other properties of the coating, such as abrasion resistance, transparency, or adhesion.

[0004] Blue light, sometimes referred to as high-energy visible (HEV) light, covers wavelengths from about 400 nm to about 500 nm. Many studies have confirmed that cumulative exposure to blue-violet light near 430 nm causes photooxidation of retinal cells, which leads to age-related macular degeneration (AMD). AMD is the leading cause of blindness in people over 55 years old. As the proportion of the elderly in the world's population increases, AMD will reach epidemic proportions. To help control the harmful effects of blue light, ophthalmic lens manufacturers have implemented blue cut-off technology (BCT) to filter and reduce retinal exposure to harmful blue-violet and UV light.

[0005] Typically, a coating composition is specifically adapted to one type of substrate and does not provide sufficient adhesion properties on other substrates. The inclusion of a blue cut-off dye typically requires modification of the coating composition in order to maintain an effective balance of adhesion, abrasion resistance, and low haze.

[0006] EP 3327091 discloses an ophthalmic lens coated with an epoxy-based coating obtained from a curable epoxy-functional composition containing an absorbent dye that blocks wavelengths that may have an impact on health.

[0007] US 2018 / 113239 provides an abrasion-resistant UV-curable coating composition for ophthalmic lenses, which comprises at least one epoxyalkoxysilane, at least one polyfunctional acrylate monomer and / or polyfunctional epoxide, and at least one UV absorber.

[0008] Although traditional epoxy coating compositions provide good initial adhesion on high-index optical substrates, these coatings show a significant decrease in adhesion after long-term exposure to full-spectrum sunlight. High-index optical substrates are known to degrade upon long-term exposure to UV light, and a common solution is to add UV absorbers to the substrate or coating to prevent photodegradation. During the curing process, some UV absorbers may interact unfavorably with the chemistry of the coating composition, resulting in an increase in haze and a decrease in the wavelength range of dye absorption. Thus, there is an industrial need for curable coating compositions suitable for blue-blocking technology that exhibit good adhesion to a wide range of optical substrates after long-term exposure to sunlight. Summary of the Invention

[0009] The inventors have found that adding a polyfunctional hydroxylated epoxy monomer to a thermally curable epoxy coating composition results in a modest improvement in the adhesion of the resulting coating to several optical substrates, including high-index lenses. Similarly, the inventors have also found that adding a UV absorber containing hydroxyphenylbenzotriazole or hydroxyphenyltriazine can slightly improve adhesion. Neither added by itself produces good adhesion after long-term exposure to full-spectrum sunlight. It has been demonstrated that the combination of a hydroxylated epoxy monomer and a UV absorber provides a significant improvement in the adhesion and durability of the resulting coating on various optical substrates. Even after 80 hours of exposure to full-spectrum sunlight, the coating does not lose adhesion. In addition, the coating retains the low haze and high abrasion resistance necessary for desired optical articles.

[0010] This disclosure relates to a thermally curable coating composition comprising at least one epoxy monomer containing two or three epoxy groups, at least one hydroxylated epoxy monomer containing at least three epoxy groups and one to three hydroxyl groups, at least one UV absorber containing hydroxyphenylbenzotriazole or hydroxyphenyltriazine, and at least one epoxy ring-opening catalyst. The composition may further comprise at least one epoxy group and at least one epoxy silane or its hydrolyzate containing at least one hydrolyzable group directly connected to a silicon atom. In some aspects, the epoxy silane is (3-glycidyloxypropyl)trimethoxysilane or hydrolyzed (3-glycidyloxypropyl)trimethoxysilane. In some aspects, the epoxy monomer does not include any hydrolyzable group directly connected to a silicon atom. In some embodiments, the epoxy monomer does not include any hydrolyzable group directly connected to a silicon atom.

[0011] The epoxy monomer and the hydroxylated epoxy monomer may account for at least 50% by weight of all epoxy group-containing compounds present in the composition. In some embodiments, the epoxy monomer is a diglycidyl ether, a triglycidyl ether, or an alicyclic epoxy. In some aspects, the hydroxylated epoxy monomer is a sorbitol polyglycidyl ether. In some embodiments, the thermally curable composition comprises two epoxy monomers, wherein one epoxy monomer is a glycidyl ether and the second epoxy monomer is an alicyclic epoxy. In additional embodiments, the composition comprises two epoxy monomers, wherein the first epoxy monomer is trimethylolethane triglycidyl ether, the second epoxy monomer is 3’,4’-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and the hydroxylated epoxy monomer is a sorbitol polyglycidyl ether. The epoxy ring-opening catalyst may be an aluminum chelate, aluminum acrylate, an aluminum alcoholate, trifluoromethanesulfonic acid, or a metal salt of trifluoromethanesulfonic acid. The composition may further comprise at least one absorptive dye. In some embodiments, the absorptive dye at least partially inhibits the transmission of light in at least one selected wavelength range between 380 and 1400 nm.

[0012] Some aspects of the present disclosure relate to a method for preparing an optical article, the method comprising: coating an optical substrate with a thermally curable coating composition comprising at least one epoxy monomer containing two or three epoxy groups, at least one hydroxylated epoxy monomer containing at least three epoxy groups and one to three hydroxyl groups, at least one UV absorber containing hydroxyphenylbenzotriazole or hydroxyphenyltriazine, and at least one epoxy ring-opening catalyst; and curing the resulting coating by heating. The composition may further comprise at least one of the following: an absorptive dye and at least one epoxy silane or its hydrolyzate containing at least one epoxy group and at least one hydrolyzable group directly connected to a silicon atom. In some aspects, the method comprises coating the optical substrate by spin coating, spraying, 3D printing, roll-to-roll coating, or inkjet printing. The coating may be heated to a temperature between 60 and 140 °C to form a non-tacky or fully cured coating.

[0013] Some embodiments of the present disclosure relate to an optical article having at least one major surface, the major surface including a coating obtained by depositing a thermocurable coating composition on an optical substrate and curing the resulting coating by heating, the thermocurable coating composition comprising at least one epoxy monomer containing two or three epoxy groups, at least one hydroxylated epoxy monomer containing at least three epoxy groups and one to three hydroxyl groups, at least one UV absorber containing hydroxyphenyl benzotriazole or hydroxyphenyl triazine, and at least one epoxy ring-opening catalyst. When tested according to ISTM 02-010, the coating exhibits at least 96% adhesion to the optical substrate after exposure to full-spectrum sunlight for at least 40 hours. In some embodiments, the optical substrate includes a thermosetting material or a polycarbonate lens having a hard coat.

[0014] Other objects, features, and advantages will become apparent from the following detailed description. However, it should be understood that the detailed description and examples, while indicating specific embodiments, are given by way of illustration only. Additionally, it is contemplated that changes and modifications will become apparent to those skilled in the art from this detailed description. Detailed Description

[0015] The various features and advantageous details are more fully explained with reference to the non-limiting embodiments detailed below. However, it should be understood that the detailed description and specific examples, while indicating embodiments, are given by way of illustration only and not by way of limitation. According to the present disclosure, various alternatives, modifications, additions, and / or rearrangements will be apparent to those of ordinary skill in the art.

[0016] The thermocurable coating compositions disclosed herein are prepared using a combination of at least one epoxy monomer, at least one hydroxylated epoxy monomer, at least one uv absorber, and at least one ring-opening catalyst to provide coatings with durable adhesion, low haze, and strong abrasion resistance after long-term exposure to sunlight. Additionally, the compositions disclosed herein are compatible with absorptive dyes and additives for many applications, including blue-blocking technology.

[0017] Thermocurable Coating Compositions

[0018] The epoxy monomers disclosed herein are cyclic ethers and are preferably epoxides (ethylene oxide). As used herein, the term "epoxide" denotes a subclass of epoxides containing a saturated three-membered cyclic ether. The epoxy groups of the epoxy monomers are preferably selected from glycidyl and alicyclic epoxy groups, more preferably from alkyl glycidyl ether groups and alicyclic epoxy groups.

[0019] In this disclosure, the term "alkyl" means a straight-chain or branched-chain, saturated or unsaturated monovalent hydrocarbon radical group preferably containing from 1 to 25 carbon atoms. The term alkyl includes acyclic groups preferably containing from 1 to 8 carbon atoms, more preferably from 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, butyl and n-hexyl, and alicyclic groups and cycloalkyl groups preferably containing from 3 to 7 carbon atoms, and cycloalkylmethyl groups preferably containing from 4 to 8 carbon atoms.

[0020] The term "alicyclic" denotes a saturated or unsaturated but non-aromatic carbocyclic group which contains one or several optionally fused rings and which may optionally be substituted by one or more of the groups cited above for aryl groups. The term "alicyclic" also includes "heteroalicyclic" groups, i.e. non-aromatic monocyclic or polycyclic groups in which one or more carbon atoms in one or more of the rings have been replaced by heteroatoms such as nitrogen, oxygen, phosphorus or sulfur. Alicyclic groups are preferably cycloalkyl groups.

[0021] The term "cycloalkyl" also includes "heterocycloalkyl" groups, i.e. non-aromatic monocyclic or polycyclic groups in which one or more carbon atoms in one or more of the rings have been replaced by heteroatoms such as nitrogen, oxygen, phosphorus or sulfur. Heterocycloalkyl preferably contains 1 to 4 internal heteroatoms. Heterocycloalkyl can be a structure containing one or more non-aromatic rings.

[0022] The term "aryl" denotes an aromatic carbocyclic group containing only one ring (e.g. phenyl) or several optionally fused rings (e.g. naphthyl or terphenyl), which may optionally be substituted by one or more groups such as but not limited to alkyl (e.g. methyl), hydroxyalkyl, aminoalkyl, hydroxy, mercapto, amino, halogen (fluorine, bromine, iodine or chlorine), nitro, alkylthio, alkoxy (e.g. methoxy), aryloxy, monoalkylamino, dialkylamino, acyl, carboxyl, alkoxycarbonyl, aryloxycarbonyl, hydroxy sulfonyl, alkoxy sulfonyl, aryloxy sulfonyl, alkyl sulfonyl, alkyl sulfinyl, cyano, trifluoromethyl, tetrazolyl, carbamoyl, alkylcarbamoyl or dialkylcarbamoyl. Alternatively, two adjacent positions of the aromatic ring may be substituted by methylenedioxy or ethylenedioxy. The term "aryl" also includes "heteroaryl" groups, i.e. aromatic rings in which one or more carbon atoms in one or more of the aromatic rings have been replaced by heteroatoms such as nitrogen, oxygen, phosphorus or sulfur.

[0023] The epoxy monomer may have two or three epoxy groups per molecule and does not include any hydrolyzable functional groups directly attached to a silicon atom. In this disclosure, the Si-O-Si group is not considered a hydrolyzable group. In some embodiments, the epoxy monomer does not include any silicon atoms.

[0024] Examples of hydrolyzable functional groups include but are not limited to alkoxy -O-R 1 where R1 Preferably represents a linear or branched alkyl or alkoxyalkyl group, preferably C 1 -C 4 alkyl; acyloxy O-C(O)R 2 , where R 2 Preferably represents an alkyl group, preferably C 1 -C 6 alkyl, and more preferably methyl or ethyl; halogen groups such as Cl and Br; an amino group optionally substituted by one or two functional groups such as an alkyl or silyl group, for example NHSiMe 3 group; an alkyleneoxy group such as isopropenyloxy; and a hydroxyl group -OH.

[0025] In some embodiments, the epoxy monomer does not contain reactive functional groups other than epoxy groups that can react with other polymerizable functional groups present in the composition and link to the polymer matrix of the coating, such as hydroxyl groups.

[0026] In some embodiments, the epoxy monomer is a diglycidyl ether, a triglycidyl ether, or an alicyclic epoxy. A glycidyl ether is a synthetic compound characterized by the following groups, where R 1 represents a monovalent group:

[0027]

[0028] Preferred alicyclic epoxy groups are shown below, where the hydrogen atoms in the structure may be substituted by one or more substituents such as those cited above as aryl substituents:

[0029]

[0030] and

[0031] In some embodiments, the epoxy monomer contains 3,4-epoxycyclohexylalkyl, such as 3,4-epoxycyclohexylmethyl and 3,4-epoxycyclohexylethyl.

[0032] Examples of epoxy monomers include but are not limited to trimethylolethane triglycidyl ether (GE-31 from CVC Thermoset Specialties), trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether (from CVC Thermoset Specialties) GE-31), trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether (from CVC Thermoset Specialties) GE-30), trimethylolpropane triglycidyl ether, triphenol triglycidyl ether, tetramethylol ethane triglycidyl ether, p-aminophenol triglycidyl ether, 1,2,6-hexanetriol triglycidyl ether, glycerol triglycidyl ether, diglycerol triglycidyl ether, glycerol ethoxylate triglycidyl ether, castor oil triglycidyl ether, propoxylated glycerol triglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, dibromoneopentyl glycol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether (Epalloy 5000 from CVC Thermoset Specialties), 3′,4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate ( 1500, Cyracure from The Dow Chemical Company TM UVR-6110 and UVR TM 6105), bis(3,4-epoxycyclohexylmethyl) adipate (Cyracure from The Dow Chemical Company TM UVR-6128), limonene diepoxide (6-methyl-3-(2-methyloxiranyl)-7-oxabicyclo[4.1.0]heptane, from Daicel Chemical Industries Ltd.) 3000), 1,3-bis[2-(3,4-epoxycyclohexyl)ethyl]tetramethyldisiloxane (SIB1092.0 from Gelest), bisphenol A diglycidyl ether (Epon TM Resin 828) from Hexion, hexahydrophthalic anhydride diglycidyl ester (CY 184 from Ciba), and derivatives thereof, and mixtures thereof.

[0033] At least one hydroxylated epoxy monomer may be a cyclic ether and preferably is an epoxide (ethylene oxide). The epoxy groups of the hydroxylated epoxy monomer are preferably selected from glycidyl groups, more preferably selected from alkyl glycidyl ether groups. As used herein, the term "hydroxylated" means the presence of one or more hydroxyl groups. The term "hydroxyl" means the -OH functional group.

[0034] In some embodiments, at least one hydroxylated epoxy monomer has at least three epoxy groups and one to three hydroxyl groups per molecule. In some aspects, the hydroxylated epoxy monomer does not include a hydrolyzable group directly connected to a silicon atom. In some embodiments, the hydroxylated epoxy monomer does not include any silicon atoms.

[0035] Examples of hydrolyzable functional groups include, but are not limited to, alkoxy groups -O-R 1 , where R 1 preferably represents a linear or branched alkyl or alkoxyalkyl group, preferably C 1 -C 4 alkyl group; acyloxy group O-C(O)R 2 , where R 2 preferably represents an alkyl group, preferably C 1 -C 6 alkyl group, and more preferably methyl or ethyl; halogen groups such as Cl and Br; an amino group optionally substituted with one or two functional groups such as an alkyl or silyl group, for example the NHSiMe 3 group; an alkyleneoxy group such as isopropenyloxy; and a hydroxyl group -OH.

[0036] Examples of hydroxylated epoxy monomers include, but are not limited to, glycerol diglycidyl ether, diglycerol tetraglycidyl ether, tetrahydroxyphenyl ethane triglycidyl ether, sorbitol polyglycidyl ether (Erisys GE-60 from CVC Thermoset Specialties), and derivatives thereof, and mixtures thereof. In some aspects, at least one hydroxylated epoxy monomer is preferably sorbitol polyglycidyl ether Erisys GE-60.

[0037] In one embodiment, the thermosettable coating composition comprises, based on the total weight of the composition, 5% to 30% by weight of the hydroxylated epoxy monomer b) according to the present invention. In another embodiment, the thermosettable coating composition comprises, based on the total weight of the composition, 10% to 25% by weight of the hydroxylated epoxy monomer b) according to the present invention.

[0038] In one embodiment, the thermosettable coating composition comprises, based on the total weight of the composition, 20% to 40% by weight of an epoxy monomer a) containing two or three epoxy groups, wherein the epoxy monomer does not include a hydrolyzable group directly connected to a silicon atom.

[0039] In some embodiments, the thermosettable composition comprises at least one dye, preferably in an amount ranging from 0.01% to 5% by weight of the composition. In some aspects, the absorbent dye at least partially inhibits the transmission of light in at least one selected wavelength range between 380 and 1400 nm.

[0040] In some aspects, the UV absorber comprises a hydroxyphenylbenzotriazole or a hydroxyphenyltriazine. The UV spectrum has multiple bands, including the UVA, UVB, and UVC bands. Among those UV bands that reach the Earth's surface, the UVA band ranging from 315 nm to 380 nm and the UVB band ranging from 280 nm to 315 nm are particularly harmful to the retina. The UV absorber is typically incorporated into an optical article to reduce or prevent UV light from reaching the retina (specifically incorporated into ophthalmic lens materials), and also to protect the substrate material itself, thereby protecting it from weathering and embrittlement and / or yellowing.

[0041] The UV absorber preferably has the ability to at least partially block light having wavelengths ranging from 10 to 450 nm. The UV absorber preferably has the ability to at least partially block light having UV wavelengths shorter than 400 nm, preferably below 385 or 390 nm, and also has an absorption spectrum extending into the visible blue light range (400 - 500 nm).

[0042] In addition to the UV absorption function, the UV absorber also enhances the adhesion of the resulting dry coating composition to the optical substrate. While the UV absorber can provide some adhesion improvement when combined with an epoxy monomer (such as trimethylolethane triglycidyl ether (Erisys GE - 31)), including the UV absorber in the coating composition with both an epoxy monomer and a hydroxylated epoxy monomer provides a significant improvement in adhesion.

[0043] UV absorbers capable of enhancing adhesion belong to the hydroxyphenylbenzotriazole or hydroxyphenyltriazine family. Examples of preferred hydroxyphenylbenzotriazole UV absorbers include, but are not limited to, 2-(2 - hydroxyphenyl)-benzotriazole, such as 2-(2 - hydroxy - 3 - tert - butyl - 5 - methylphenyl)chlorobenzotriazole, 2-(2′ - hydroxy - 5′ - tert - octylphenyl)benzotriazole, 2-(3′ - methallyl - 2′ - hydroxy - 5′ - methylphenyl)benzotriazole, or other allylhydroxymethylphenylbenzotriazoles, 2-(2 - hydroxy - 5 - methylphenyl)-2H - benzotriazole (Seesorb 701), 2-(3,5 - di - tert - amyl - 2 - hydroxyphenyl)benzotriazole, and 2 - hydroxy - 5 - acryloyloxyphenyl - 2H - benzotriazole disclosed in U.S. Patent No. 4,528,311. Examples of preferred hydroxyphenyltriazine UV absorbers include, but are not limited to 477 and 479.

[0044] Examples of preferred commercially available UV absorbers include, but are not limited to, those from BASF Corporation and Compounds, Seesorb 701 and 703 from Shipro Kasei Kaisha, UV-400 from Hunan Chemical BV, and from Chitec Technology Co., Ltd, and Viosorb 550 from Kyodo Chemicals. More particularly, , , ,

[0045] , ,

[0046] , ,

[0047] , ,

[0048] 1063 and 54005, and Viosorb 550 from Kyodo Chemicals. More particularly, 477 and 479, both being hydroxyphenyltriazines, are preferred UV absorbers. Suitable UV absorbers can be commercially available as blends of UV absorbers and hindered amine light stabilizers (HALS) such as 5151.

[0045] Absorptive dyes or attenuation transmissivity dyes provide local regions of reduced light transmittance, i.e., local transmittance minima, in specific wavelength regions. By incorporating dyes that reduce the light transmittance in specific wavelength regions, the non-reduced wavelength regions appear as regions with relatively high transmittance, i.e., local transmittance maxima. By adjusting the local minima and maxima to achieve the desired transmission spectrum, including specific dyes in the lens enhances the color contrast.

[0046] Absorptive dyes can be selected to reduce the transmittance over the desired wavelength range. The dye concentration can be selected to adjust the degree of reduction in transmittance. The total amount of dye can be adjusted to customize the transmission spectrum. By combining multiple dyes, various transmittance curves can be tailored for specific applications. The phrases "transmittance-reducing", "attenuation transmissivity", "color absorption", or "light absorption" are used interchangeably herein.

[0047] The amount and / or characteristics of absorptive dyes can be selected to balance the color of the light passing through the optical article. The amount and / or characteristics of absorptive dyes can be selected to impart color or hue to the optical article. Absorptive dyes can be selected from azo dyes, polymethine dyes, arylmethylene dyes, polyene dyes, anthracinedione dyes, pyrazolone dyes, anthraquinone dyes, isoindolinone dyes, auinophtalone dyes, naphthalenediamine dyes, and carbonyl dyes. Specific examples of such dyes include, but are not limited to, ABS420, D&C Violet, Savinyl Blue RS, PeroxBlue, Solvent Red 135, and Solvaperm Red RR.

[0048] In some embodiments, the epoxy ring-opening catalyst promotes the polycondensation and / or crosslinking reaction of the epoxy compounds of the composition. Preferred catalysts are capable of curing the epoxy composition at a temperature low enough (preferably ≤ 110 °C, more preferably ≤ 100 °C) so as not to damage the underlying substrate and / or have an adverse effect on other coatings or coating components.

[0049] To obtain a storage-stable thermosettable composition, the preferred catalyst does not catalyze epoxy ring-opening at room temperature. This feature prevents premature polymerization or the formation of prepolymers in the coating composition during storage or during production, thus extending the pot-life and shelf life. In this regard, the catalyst is preferably a blocked catalyst or a latent catalyst (such as a buffered acid catalyst). The blocked catalyst does not react until it reaches its respective deblocking temperature. The preferred catalyst is inactive at ambient temperature (20 °C) and is only activated to catalyze epoxy ring-opening when heated to typically 70 °C to 80 °C or higher.

[0050] Exemplary blocked catalysts or latent catalysts are based on trifluoromethanesulfonic acid (triflic acid), dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid (DNNDSA), and ammonium hexafluoroantimonate (Lewis acid), metal salts of trifluoromethanesulfonic acid (Lewis acids buffered to reduce their reactivity at ambient temperature). Both trifluoromethanesulfonic acid and metal salts of trifluoromethanesulfonic acid are preferred catalysts. Other useful catalysts include carboxylic anhydrides such as hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, or Lewis acid catalysts including BF 3 and BCl 3 amine complexes.

[0051] In some embodiments, the epoxy ring-opening catalyst is selected from aluminum chelates, aluminum acrylates, and aluminum alcoholates. When an aluminum catalyst is used, the composition preferably does not contain other epoxy ring-opening catalysts such as acid catalysts or ammonium salts of metal anions. Preferred aluminum acrylates and aluminum alcoholates have the general formulas Al(OC(O)R) n (OR′) 3-n and Al(OSiR”3) n (OR′) 3-n , where R and R′ are straight-chain or branched alkyl groups containing from 1 to 10 carbon atoms, R” is a straight-chain or branched alkyl group containing from 1 to 10 carbon atoms, a phenyl moiety, an acyl moiety having the formula OC(O)R where R is as defined above, and n is an integer from 1 to 3. Preferably, R′ is isopropyl or ethyl, and R and R” are methyl.

[0052] The epoxy ring-opening catalyst can be used in an amount ranging from 0.1% to 5% by weight, preferably from 0.2% to 3.5% by weight, more preferably from 0.5% to 3% by weight, based on the weight of the composition.

[0053] In some embodiments, the thermosettable composition further comprises at least one epoxy silane or its hydrolyzate having at least one hydrolyzable group directly linked to a silicon atom and at least one epoxy group. The epoxy silane preferably has from 2 to 6, more preferably 2 or 3, hydrolyzable functional groups directly linked to the silicon atom that generate OH groups upon hydrolysis. Examples of hydrolyzable functional groups include, but are not limited to, alkoxy -O-R 1 , where R 1 preferably represents a straight or branched alkyl or alkoxyalkyl group, preferably C 1 -C 4 alkyl; acyloxy O-C(O)R 2 , where R 2 preferably represents an alkyl group, preferably C 1 -C 6 alkyl, and more preferably methyl or ethyl; halogen groups such as Cl and Br; an amino group optionally substituted with one or two functional groups such as an alkyl or silyl group, for example the NHSiMe 3 group; an alkyleneoxy such as isopropenyloxy; and a hydroxyl group -OH.

[0054] Preferred epoxy silanes are epoxy alkoxysilanes, and more preferably those having one epoxy group and three alkoxy groups. The epoxy group of the epoxy silane is preferably selected from glycidyl and alicyclic epoxy groups, more preferably from alkyl glycidyl ether groups and alicyclic epoxy groups.

[0055] Examples of such epoxy silanes include λ-glycidoxypropyltriethoxysilane, λ-glycidoxypropyltrimethoxysilane (GLYMO), 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane. Among those silanes, γ-glycidoxypropyltrimethoxysilane (GLYMO) is preferred.

[0056] In some embodiments, the epoxy silane is hydrolyzed before being mixed with the other components of the composition. Hydrolysis can be carried out, as is known in the art, using an acidic catalyst (such as hydrochloric acid or acetic acid) in the presence of water.

[0057] In some embodiments, the epoxy silane is used in an amount of less than 30% by weight, preferably less than 20% by weight, relative to the total weight of the composition. This amount can be less than 10% or less than 5% by weight and even 0%. Even though the epoxy silane is usually hydrolyzed before being mixed with the other components of the composition, the amount of the epoxy silane is conventionally defined as the weight of the initial precursor before its hydrolysis.

[0058] The thermosettable composition may also comprise several additives such as surfactants, radical scavengers, and antioxidants.

[0059] Method for preparing an optical article

[0060] The substrate should be understood to mean an uncoated substrate and generally has two major surfaces. The substrate may in particular be an optically transparent material having the shape of an optical article (such as an ophthalmic lens destined to be mounted on spectacles). In this context, the term "substrate" should be understood to mean the basic constituent material of an optical lens and more particularly an ophthalmic lens. Such a material serves as a support for a stack of one or more functional coatings or layers.

[0061] The substrate of an optical article coated with a coating on at least one major surface may be a mineral or an organic glass, such as an organic glass made of a thermoplastic or a thermosetting plastic, generally chosen from ophthalmic-grade transparent materials used in the ophthalmic industry.

[0062] As particularly preferred types of substrate materials, mention may be made of polycarbonate, polyamide, polyimide, polysulfone, copolymers of polyethylene terephthalate and polycarbonate, polyolefins such as polynorbornene, resins resulting from the polymerization or (co)polymerization of alkylene glycol diallyl carbonates, such as polymers and copolymers of diethylene glycol bis(allyl carbonate) (e.g., sold under the trade name by PPG Industries), polycarbonates such as those derived from bisphenol A, (meth)acrylic or thio(meth)acrylic polymers and copolymers such as polymethyl methacrylate (PMMA), urethane and thiourethane polymers and copolymers, epoxy polymers and copolymers, episulfide polymers and copolymers.

[0063] Before depositing the coating, the substrate surface is generally subjected to a physical or chemical surface activation and cleaning treatment in order to improve the adhesion of the layer to be deposited, as disclosed in WO 2013 / 013929.

[0064] In some aspects, an epoxy coating is deposited on the optical substrate of the optical article and preferably in direct contact with the substrate. The deposition is carried out using methods known in the art, preferably by spin coating, spraying, 3D printing, roll-to-roll coating, or inkjet printing of the thermosettable composition.

[0065] The curing of the heat-curable composition can be carried out in one step or in two steps, including: a first pre-curing step at a temperature of at least 60°C, preferably at least 70°C, more preferably at least 75°C, typically from 75°C to 100°C or from 80°C to 100°C, for at least 5 minutes, usually from 10 to 25 or 30 minutes, typically 15 minutes, to form a non-tacky coating; and a second step of heating the optical article coated with the non-tacky coating to a temperature higher than or equal to the temperature of the pre-curing step, preferably at least 90°C or 95°C, more preferably at least 98°C or 100°C, typically from 100°C to 140°C, preferably from 100°C to 115°C, for 1 to 3 hours, usually at least two hours, preferably for 2.5 to 3.5 hours, typically 3 hours, to obtain a fully cured insoluble coating. An alternative coating curing method is a first curing step at a temperature of 100°C, preferably at least 110°C, more preferably at least 125°C, for at least 30 minutes, usually 60 minutes, and a second step at a temperature lower than the first step, preferably 100°C or lower, preferably at 80°C for 30 minutes, usually 60 minutes. The method produces a transparent and clear coating with low haze.

[0066] The thickness of the cured coating can be adapted to the specific application required and generally ranges from 0.5 μm to 50 μm, preferably from 1 μm to 20 μm, more preferably from 2 μm to 10 μm.

[0067] Optical article

[0068] Any embodiment of any of the disclosed compositions and / or methods can consist of or consist essentially of any of the described elements and / or features and / or steps - rather than comprising / including / containing / having any of the described elements and / or features and / or steps. Thus, in any claim, the term "consisting of" or "consisting essentially of" can replace any of the above-described open-ended linking verbs in order to change the scope of a given claim from what it would otherwise be using an open-ended linking verb.

[0069] The optical article is preferably a transparent optical article, particularly an optical lens or a lens blank, more preferably an ophthalmic lens or a lens blank. The term "ophthalmic lens" is used to mean a lens adapted to a spectacle frame to protect the eyes and / or correct vision. The lens can be selected from non-prescription lenses, single-focus lenses, bifocal lenses, trifocal lenses, and progressive lenses. Although the field of ophthalmic optics is preferred, it will be understood that the embodiments disclosed herein can be advantageously applied to other types of optical elements where filtering specific wavelengths may be beneficial, such as lenses for optical instruments, protective glasses, particularly filters for photography, astronomy, or the automotive industry, optical aiming lenses, eye protectors, optical components of lighting systems, screens, assembly glass, etc.

[0070] If the optical article is an optical lens, it may be coated on its front major surface, rear major surface, or both surfaces with one or more coatings as disclosed herein. As used herein, the back side of the substrate is intended to mean the surface that is closest to the wearer's eye when the article is in use. The surface is typically concave. In contrast, the front side of the substrate is the surface that is farthest from the wearer's eye when the article is in use. The surface is typically convex. The optical article may also be a plano article, i.e., an optical article that does not provide vision correction.

[0071] As used herein, a coating that is "on" a substrate / coating or has been deposited "on" a substrate / coating is defined as a coating that (i) is disposed above the substrate / coating, (ii) does not necessarily contact the substrate / coating, i.e., one or more intermediate coatings may be inserted between the substrate / coating and the relevant coating (however, it preferably contacts the substrate / coating), and (iii) does not necessarily completely cover the substrate / coating. When a first coating is said to be under a second coating, it is understood that the second coating is farther from the substrate than the first coating.

[0072] The term "substantially" and its variants are defined as being largely but not necessarily completely as specified as understood by one of ordinary skill in the art, and in one non-limiting embodiment substantially means within 10%, within 5%, within 1%, or within 0.5%.

[0073] A "derivative" of a parent compound refers to a chemically modified parent compound or an analogue thereof, where at least one substituent is not present in the parent compound or the analogue. One such non-limiting example is a parent compound that has been covalently modified. Typical modifications are amines, carbohydrates, alkyl groups, acyl groups, esters, pegylation, etc.

[0074] The term "about" or "approximate" or "substantially invariant" is defined as being close to what is understood by one of ordinary skill in the art, and in one non-limiting embodiment, these terms are defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0075] When used in conjunction with the term "comprising" in the claims and / or the specification, the word "a" or "an" may mean "one", but also conforms to the meaning of "one or more", "at least one", and "one or more than one".

[0076] As used in this specification and in one or more claims, the word “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0077] The compositions and methods for their use can “comprise any ingredient or step disclosed throughout the specification”, “consist essentially of” or “consist of”.

[0078] Examples

[0079] Preparation of wet coating compositions C1 - C4

[0080] Four preliminary epoxy solutions were prepared by mixing 3’,4’-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (epoxy monomer 1, 1500), trimethylolethane triglycidyl ether (epoxy monomer 2, Erisys GE-31), sorbitol polyglycidyl ether (hydroxylated epoxy monomer, Erisys GE-60) and a solvent (Dowanol PM) containing propylene glycol methyl ether as the major isomer in a container, and stirring it for 30 minutes. C1 prepared without the hydroxylated epoxy monomer is a reference coating.

[0081] Then the preliminary epoxy solutions were combined with a hexafluorantimonate-based catalyst (CXC-1612) for thermal-initiated cationic polymerization, propylene carbonate, methanol, aluminum acetylacetonate (Al(AcAc) 3 , epoxy ring-opening catalyst) and a fluorinated aliphatic polyester surfactant (Fluorad FC-4434, surfactant) in dipropylene glycol, and mixed for 30 minutes.

[0082] In another container, (3-glycidyloxypropyl)trimethoxysilane (GLYMO, epoxy silane monomer) was mixed with 0.1N HCl for at least one hour, then added to the four combined solutions prepared above and mixed for 30 minutes. The percentages of each component in the wet coating compositions of Examples C1 - C4 are shown in Table 1.

[0083] Table 1. Wet Coating Compositions for Examples C1 - C4 (Hydroxylated Epoxy Monomers, No UV Absorbent)

[0084]

[0085] First, different finished single vision (FSV) lenses (CR - 39, Trivex, PDQ PC, or MR7) and semi - finished (SF) lenses (MR8 or 1.74) were cleaned and dried with soap and water. Next, the convex side of each lens was corona - treated for 15 - 30 seconds. Finally, the lenses were cleaned and dried with deionized water. Each lens was spin - coated with the above coating composition solutions (C1, C2, C3, and C4) at a fixed speed (400 rpm / 8 s and 800 rpm / 10 s). Then the lenses were pre - cured at 80 °C for 15 minutes and further cured at 100 °C for 3 hours. The thickness of the resulting dry coating on the lenses was between 4 and 7 μm.

[0086] Evaluation of the C1 - C4 Dry Coating Properties

[0087] According to the ISTM 02 - 010 standard, a dry adhesion test (referred to as the cross - hatch tape peel adhesion test) was performed on the coated articles. The test was carried out on the coated articles by using a tool with six (6) parallel blades spaced 1 mm apart to cut a 25×1 square mm grid. The grid was cut into the coating, at least 5 to 10 mm from the edge of the lens. Then, a piece of 3M SCOTCH 600 tape that had not been exposed to air was removed from the tape roll, and it was evenly applied to the grid using a plastic squeegee, with approximately 15 to 20 mm of the tape extending beyond the edge of the lens. The tape was quickly removed from the lens with a brisk, rapid, continuous motion. This was repeated 5 times on the same grid. The adhesion performance of the coating was scored on a scale from 0 to 5. An adhesion score of 0 means no coating loss. The adhesion scores were as follows:

[0088] Table 2. Adhesion Test Scores

[0089] Adhesion score Removed squares Remaining intact area % 0 0 100 1 <1 96-100 2 1 to 4 84-96 3 >4 to 9 64-84 4 >9 to 16 36-64 5 >16 <36

[0090] Simulated Aging

[0091] After evaluating the coating by the dry adhesion test, each example lens was subjected to a Q - sun test to simulate the effect of sunlight exposure on the coated optical articles. The Q - sun test consisted of placing the coated optical articles at a relative humidity of 20% (±5%) and a temperature of 23 °C (±5 °C) In a Xe-3 xenon chamber (which reproduces full-spectrum sunlight), and expose its convex side to the light for one or two cycles (each cycle is 40 hours). If the lens is rated 0 or 1 in the dry adhesion test, it is further tested for one or two cycles in the Q-sun test; if it is rated 2 or higher in the dry adhesion test or the first 40-hour cycle, there is no subsequent adhesion test (n / a).

[0092] Table 3 shows the adhesion scores of each example coating (C1 - C4) on each substrate before and after 40 or 80 hours of Q-sun exposure. The dry coatings of Comparative Examples C1 - C4 show that an increasing amount of hydroxylated epoxy monomer (GE-60) provides improved initial adhesion on high refractive index substrates before and after Q-sun exposure. Coating C4 (with a relatively high content of hydroxylated epoxy monomer) shows the highest adhesion scores on MR7 and MR8 substrates. As the amount of hydroxylated epoxy monomer in the coating increases, the adhesion properties of the coating on high refractive index substrates are improved. However, after 40 hours of Q-sun exposure, Coating C4 fails on the 1.74 substrate. In these substrates, an increasing amount of hydroxylated epoxy monomer may reduce the solubility of the dye and / or increase the photodegradation of the dye.

[0093] Table 3. Adhesion test results after Q-Sun exposure for Examples C1 - C4

[0094]

[0095] Comparative Examples with UV Absorbents

[0096] Prepare comparative coating composition solutions (C5 - C11) using the same procedure as C1 above, except that each solution includes a UV absorbent selected from the group consisting of: CarboProtect (TCP), 477 (T477), 479 (T479), and 1130 (T1130). The compositions of Comparative Examples C9, C10, and C11 contain approximately twice the amount of their respective UV absorbents as Examples C5, C7, and C8. Table 3 shows the percentage of each component in the wet coating compositions of Examples C5 - C11.

[0097] Table 4. Wet coating compositions of Examples C5 - C11 (UV absorbents, no hydroxylated epoxy monomer)

[0098]

[0099]

[0100] Evaluation of C5 - C11 Dry Coating Properties

[0101] Each of the above coating compositions (C5 - C11) was spin - coated onto an MR7 lens substrate and cured according to the same procedure as in Example C1 above. Table 5 shows the adhesion scores of each example coating (C5 - C11) on a high - refractive - index MR7 substrate before and / or after 40 or 80 hours of Q - sun exposure. When compared with the reference example (C1), three coatings containing TCP, T477, and T479 (C5, C6, and C7 respectively) showed a slight improvement in adhesion on the high - refractive - index substrate (MR7); however, the coating containing T1130 (C8) did not show an improvement compared to the reference example. The UV absorber alone does not cause sufficient adhesion of the coating on the high - refractive - index substrate after Q - sun exposure. After 0 or 40 hours of Q - sun exposure, all coatings did not pass the adhesion test on the MR7 substrate. In addition, even without Q - sun exposure, doubling the amount of UV absorber in the compositions (C9 - C11) significantly reduced the adhesion of the coating.

[0102] Table 5. Adhesion Test Results after Q - Sun Exposure for Examples C5 - C11

[0103]

[0104] Examples (D1 - D5) Comprising Hydroxylated Epoxy Monomer and UV Absorber

[0105] The following coating composition solutions (D1 - D5) were prepared using the same procedure as above, but each solution contained both a hydroxylated epoxy monomer (GE - 60) and a UV absorber (T479 or T1130). For different coating composition solutions, the ratio of the hydroxylated epoxy monomer to the UV absorber was varied to obtain optimal coating adhesion on high - refractive - index substrates (MR7, MR8, and 1.74 lenses). Table 6 shows the percentage of each component in the wet coating compositions of Examples D1 - D5 of the present invention.

[0106] Table 6. Wet Coating Compositions of Examples D1 - D5 (UV Absorber + Hydroxylated Epoxy Monomer)

[0107]

[0108]

[0109] Evaluation of D1 - D5 Dry Coating Properties

[0110] Coatings D1, D2, and D3 were each spin-coated onto six different optical substrates (CR-39, Trivex, PDQPC, MR7, MR8, and 1.74 lenses) and cured according to the same procedure as in Example C1 above. Coatings D4 and D5 were only applied to the 1.74 lenses, i.e., the optical substrate with the highest refractive index, but were otherwise prepared in the same manner as Examples D1 - D3.

[0111] Table 7 shows the adhesion scores for each dry coating example (D1 - D3) on each optical substrate before and after 40 or 80 hours of Q-sun exposure. Even after 80 hours of Q-sun exposure, each coating example exhibited excellent adhesion on each substrate. The adhesion improvement from the combination of the hydroxylated epoxy monomer and the UV absorber exceeded any improvement expected based on the results of coatings containing only one of the components.

[0112] Table 7. Adhesion test results after Q-Sun exposure for Examples D1 - D3

[0113]

[0114] To further examine dry coating examples D1 - D3, CR-39 lenses with the dry coatings were subjected to haze and abrasion resistance tests. The results of these tests are shown in Table 8. Although the ratios of GE-60 and T479 in D1, D2, and D3 were different, the results for all three examples showed low haze and sufficient abrasion resistance.

[0115] As disclosed in WO 2012 / 173596, haze was measured on a Hazeguard XL 211 Plus device from BYK-Gardner according to standard ASTM D1003-00. Since haze is a measure of the percentage of transmitted light scattered more than 2.5° from the axis of the incident light, the lower the haze value, the lower the turbidity. Generally, for the optical articles described herein, a haze value of less than or equal to 0.3% is acceptable, and more preferably less than or equal to 0.2%.

[0116] Table 8. Haze and Sand Bayer results on CR-39 lenses for dry coating examples D1 - D3

[0117] Dry coating D1 D2 D3 Haze, % 0.1 0.1 0.1 Wear 0.7-0.8 Approximately 0.7 Approximately 0.6

[0118] Specific application: Blue cut-off filter lenses

[0119] A coating composition (D6) similar to the low haze and abrasion-resistant coating of Example D2 was prepared. The coating composition D6 was prepared by mixing three blue-blocking dyes (ABS420, D&C Violet, and Savinyl Blue RS) with an epoxy monomer 1 (Uvacure 1500, 3’,4’-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate) and propylene glycol methyl ether (solvent, Dowanol PM) in a container, and stirring it for 30 minutes to produce an epoxy solution. An epoxy monomer 2 (trimethylolethane triglycidyl ether, Erisys GE-31), a hydroxylated epoxy monomer (sorbitol polyglycidyl ether, Erisys GE-60), an epoxy ring-opening catalyst (aluminum acetylacetonate, Al(AcAc) 3 ), a surfactant (Fluorad FC-4434), and an additional solvent (methanol) were added to the epoxy solution and stirred for 30 minutes to 1 hour. In a separate container, an epoxy silane monomer ((3-glycidyloxypropyl)trimethoxysilane, GLYMO) was mixed with 0.1N HCl for at least one hour, added to the previously mixed epoxy solution, and stirred for an additional 30 minutes. The percentages of each component in the wet coating composition of Example D6 are shown in Table 9. The composition of Example I6 is similar to that of Example D2.

[0120] Table 9. Wet Coating Composition of Example D6

[0121]

[0122] The convex sides of three lenses (two CR-39 lenses and one PDQ PC lens) were corona-treated for 15 - 30 seconds. Then the lenses were cleaned and dried with soap and water. Each lens was spin-coated with the above coating composition solution (D6) at a fixed speed (400 rpm / 8 s and 800 rpm / 10 s). Then the lenses were pre-cured at 80 °C for 15 minutes and further cured at 100 °C for 3 hours. The thickness of the resulting dry coating on the lenses was between 5.4 and 6.5 μm.

[0123] Evaluation of D6 Dry Coating Properties

[0124] The coatings on all three lenses showed the same adhesion properties as the coatings on the same lenses in Example D2. The following Table 10 shows additional characteristics of the dry coating, such as haze, abrasion resistance, and blue-blocking performance (BVC%).

[0125] The light transmittance factor Tv in the visible spectrum was measured in transmission mode (angle of incidence: 0°) from the wearer's perspective using a Cary 50 spectrophotometer from Hunter Associates, where the back (concave) side of the lens (2 mm thickness at the center) faced the detector and light entered on the front side of the lens. Tv was measured under D65 illumination conditions (daylight).

[0126] Protection against phototoxic blue light by the coatings of the present invention can be demonstrated by calculating the average blue light protection factor BVC between 400 nm and 450 nm weighted by the light hazard function B'(λ) based on the transmission spectrum. This factor is defined by the following relationship and measured at 0° incidence:

[0127]

[0128] where T(λ) represents the lens transmittance factor at a given wavelength, measured at an angle of incidence between 0° and 17°, preferably 0°, and B'(λ) represents the light hazard function (relative spectral function efficiency) shown in FIG. 1 of Publication WO2017 / 077359 in the name of the present applicant. The light hazard function was generated through the work between the Paris Vision Institute and Essilor International. It can be seen from this figure that blue light is most dangerous to the human eye at 428 - 431 nm. Several values of the B'(λ) function between 400 and 450 nm are given below:

[0129]

[0130]

[0131] Table 10. Haze, Sabic, and blue cut-off results for dry coating example D6

[0132]

[0133] In a separate set of experiments, FSV CR-39 plano lenses were first subjected to caustic cleaning and then dip-coated with the wet coating composition D6 at a discharge rate of 1.7 mm / s. The resulting lenses exhibited a blue cut-off block of greater than 40%.

[0134] In summary, before and after long-term Q-sun exposure, the inclusion of both a hydroxylated epoxy monomer and a UV absorber in a thermocurable coating composition results in excellent adhesion on a high refractive index optical substrate. Additionally, the compositions of the present invention allow for the inclusion of blue cut-off dyes, color balancing dyes, and other dyes to provide durable, transparent, and effective coatings for optical articles such as ophthalmic lenses.

[0135] A claim should not be construed to include a means-plus-function or step-plus-function limitation, unless such a limitation is expressly recited in a given claim by use of one or more of the phrases "means for" or "step for".

Claims

1. A thermosettable coating composition comprising: a) at least one epoxy monomer containing two or three epoxy groups, wherein the epoxy monomer does not include a hydrolyzable group directly connected to a silicon atom; b) sorbitol polyglycidyl ether Erisys GE-60 in an amount of 10% - 25% by weight based on the total weight of the composition; c) at least one UV absorber containing hydroxyphenylbenzotriazole or hydroxyphenyltriazine; and d) at least one epoxy ring-opening catalyst; wherein at least one epoxy monomer includes trimethylolethane triglycidyl ether; and wherein the composition further comprises at least one epoxy silane in an amount of 10% or less by weight based on the total weight of the composition, the epoxy silane containing at least one hydrolyzable group directly connected to a silicon atom and at least one epoxy group, or its hydrolyzate.

2. The composition according to claim 1, wherein, the epoxy monomer is diglycidyl ether, triglycidyl ether, or an alicyclic epoxy.

3. The composition according to claim 1 or 2, wherein, the epoxy monomer and sorbitol polyglycidyl ether Erisys GE-60 account for at least 50% by weight of all epoxy group-containing compounds present in the composition.

4. The composition according to claim 1 or 2, wherein, the epoxy silane is (3-glycidyloxypropyl)trimethoxysilane or hydrolyzed (3-glycidyloxypropyl)trimethoxysilane.

5. The composition according to claim 4, which comprises a second epoxy monomer that is 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

6. The composition according to claim 1 or 2, wherein, the epoxy ring-opening catalyst is an aluminum chelate, aluminum acrylate, aluminum alcoholate, trifluoromethanesulfonic acid, or a metal salt of trifluoromethanesulfonic acid.

7. The composition according to claim 1 or 2, which further comprises at least one absorptive dye.

8. The composition according to claim 7, wherein, the absorptive dye at least partially inhibits the transmission of light in at least one selected wavelength range between 380 and 1400 nm.

9. A method for preparing an optical article, which comprises: a) coating an optical substrate with the thermosettable coating composition according to any one of claims 1 to 8; and b) curing the resulting coating by heating.

10. The method according to claim 9, wherein, coating the optical substrate includes spin coating, spraying, 3D printing, roll-to-roll coating, or inkjet printing.

11. The method according to claim 9 or 10, wherein, heating the resulting coating to a temperature between 60 °C and 140 °C to form a non-tacky or fully cured coating.

12. An optical article having at least one major surface, the major surface including a coating obtained by depositing and curing a composition on an optical substrate according to the method of any one of claims 9 to 11, wherein when tested according to ISTM02-010, after exposure to full-spectrum sunlight for at least 40 hours, the coating exhibits at least 96% adhesion to the optical substrate.

13. The optical article according to claim 12, wherein, the optical substrate includes a thermosetting material or a polycarbonate lens having a hard coating.

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