CURABLE COMPOSITIONS.

Abstract

A curable composition is provided comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (ii) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (iii) an ethylenically unsaturated monomer. The invention also provides coatings formed from the curable composition and articles coated with the curable composition.

Description

CURABLE COMPOSITIONS CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to application No. 62 / 943,962, filed on December 5, 2019, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF INVENTION

[0002] This invention relates in general to curable compositions that are particularly suitable as coatings for optical articles. BACKGROUND OF THE INVENTION TECHNICAL CONSIDERATIONS

[0003] Radiation-curable hard coating products, such as those cured by exposure to ultraviolet radiation, are widely used in the prescription laboratory segment of the optical market to protect the surface side of a semi-finished lens that has been processed to achieve the prescribed power and configuration for the end user. To achieve hard coating adhesion to various common ophthalmic lens materials in the industry, epoxy-functional alkoxysilanes are well-known and widely used. However, these epoxy-functional alkoxysilanes are typically fully or partially hydrolyzed to allow the formation of condensed oligomers.

[0004] The published prior art describes compositions where the level of unhydrolyzed epoxy-functional alkoxysilane must be below 50 percent by weight of the total formula weight to achieve acceptable performance. U.S. Patent No. 6,780,232 teaches the hydrolysis of epoxy-functional alkoxysilane in an acidic environment. Hydrolysis of the alkoxy groups releases the associated alcohol to form silanol groups, which are relatively unstable and tend to condense spontaneously. In this example, the alkoxysilane is reacted with a stoichiometrically sufficient amount of water to hydrolyze at least 50% of the alkoxy groups. The solution is mixed for at least 16 hours. Self-condensation of the hydrolyzed alkoxysilane species yields a mixture of primarily oligomeric and polymeric products. κηοαηη / ζζηζ / Ε / γίΛΐ

[0005] Surprisingly, it has been discovered that by hydrolyzing less than 50 percent of the hydrolyzable groups under conditions that discourage spontaneous condensation, curable compositions can be achieved that provide improved properties. BRIEF DESCRIPTION OF THE INVENTION

[0006] The present invention provides a curable composition comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (i) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (iii) an ethylenically unsaturated monomer.

[0007] The invention also relates to coatings formed from the curable composition, as well as to articles comprising a substrate and a coating formed from the curable composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 represents the gas permeation chromatogram of the product of Example 1 described later herein.

[0009] Figure 2 represents the gas permeation chromatogram of the product of Comparative Example 2 described later herein.

[0010] Figure 3 represents an overlay of the chromatograms of Figures 1 and 2 in relation to the gas permeation chromatogram of pure, unhydrolyzed 3-glycidoxypropyltrimethoxysilane as a reference sample. DESCRIPTION OF THE INVENTION

[0011] All numbers used in the descriptive memorandum and the claims shall be understood to be modified in all cases by the expression "around". It shall be understood that all ranges disclosed herein encompass the initial and final range values ​​and each and every subrange included therein. The ranges stated herein represent the average values ​​over the specified range.

[0012] The terms polymer or polymeric include oligomers, homopolymers, copolymers, and terpolymers. For the purposes of the present invention, the term monomeric in the context of alkoxysilane means that the alkoxysilane or (silanol) groups hydrolyzed therefrom remain uncondensed or non-condensed.

[0013] Non-hydrolyzed means a percentage of hydrolysis of hydrolyzable groups of less than 5 percent, such as less than 3 percent, such as less than 1 percent, such as 0 percent. For example, during the preparation of component (i), it is preferred that water not be deliberately added to hydrolyze component (i).

[0014] The invention comprises, consists of, or essentially consists of the following aspects of the invention, in any combination.

[0015] The invention relates to curable compositions, such as thermally and / or radiation-curable coating compositions, which are suitable for optical articles.

[0016] The present invention provides a curable composition comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (ii) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (iii) an ethylenically unsaturated monomer. The first alkoxysilane and the second alkoxysilane may be the same or different. Furthermore, it should be mentioned that component (i) may comprise two or more first alkoxysilanes that are not hydrolyzed. Likewise, component (ii) may comprise two or more second alkoxysilanes, provided that 5 to 45 percent of the hydrolyzable groups present are hydrolyzed. That is, the second alkoxysilanes present in component (ii) are reacted with a sufficient amount of water to effect the hydrolysis of 5 to 45 percent, or 10 to 40 percent, of the alkoxy groups present in component (ii).

[0017] In addition, it should be noted that component (i) and component (ii) are prepared and added to the composition separately, i.e., as separate components.

[0018] Component (i) of the curable composition also comprises at least 30 percent monomeric alkoxysilane. For example, component (ii) of the curable composition may comprise from 30 to 100 percent monomeric alkoxysilane, such as from 30 to 95 percent or from 35 to 90 percent monomeric alkoxysilane, where the percentages are based on the total weight of component (ii).

[0019] Each of the first alkoxysilanes and the second alkoxysilanes present in the curable composition may independently have the following structure (I): (I) RxS¡(OR')4-x where x is 0, 1, 2 or 3; R is an organic radical independently selected from the group consisting of Ci to Ce alkyl, vinyl, methoxyalkyl, phenyl, γ-glycidoxyalkyl and κηοαηη / ζζηζ / E / γίΛΐ methacryloxyalkyl; and each R' is independently a Ci to O alkyl group or, in some cases, an aryl group.

[0020] Examples of suitable alkoxysilanes may include, but are not limited to, methyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, and acryloxysilane.

[0021] Partial hydrolysis can be carried out by adding a stoichiometrically sufficient amount of water to hydrolyze the target percentage of hydrolyzable groups (e.g., alkoxy groups), such as 5 to 45 percent of the hydrolyzable groups. To accelerate the hydrolysis reaction, an acidic or basic catalyst can be used. The hydrolysis of alkoxysilanes produces silanol groups, which can spontaneously condense to form siloxane oligomers. By carrying out the partial hydrolysis reaction at low temperatures, such as between 0°C and 20°C, for a period of 120 minutes or less, the amount of spontaneous condensation can be minimized. An exothermic reaction may occur during this time. The alcohol species released through the hydrolysis of the alkoxy groups, and optionally water, can be removed from the hydrolysis product under vacuum.The relative amount of monomeric (i.e., non-condensed) material can be measured by gel permeation chromatography (GPC), as described herein. For the purposes of the present invention, the amount of monomeric alkoxysilane material remaining after hydrolysis can be at least 30 percent, depending on the product mixture. Hydrolysis of larger stoichiometric amounts of water, for example, up to 50 percent, 60 percent, or 70 percent of the hydrolyzable groups, can be considered, provided that the reaction conditions are such that the resulting product mixture comprises the required amount of monomeric alkoxysilane.

[0022] The curable composition of the present invention also comprises component (ii) comprising an ethylenically unsaturated monomer. A wide variety of ethylenically unsaturated monomers (including oligomers) may be employed in the curable composition of the invention. Useful ethylenically unsaturated compounds include both monofunctional and difunctional ethylenically unsaturated monomers, but other polyfunctional or additional ethylenically unsaturated monomers may also be included. For the purposes of the present invention, suitable ethylenically unsaturated monomers may also include vinyl monomers as described below.

[0023] Examples of polyfunctional ethylenically unsaturated monomers, including difunctional, trifunctional, and tetrafunctional monomers, include neopentylglycol diacrylate, pentaerythritol triacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, tetraethylene glycol diacrylate, 1,3-butylene glycol diacrylate, trimethylolpropane trimethacrylate, 1,3-butylene glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol tetraacrylate, tetraethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol diacrylate, diacrylate diethylene glycol κηοαηη / ζζηζ / Ε / γίΛΐ, glycerol diacrylate, glycerol triacrylate, 1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, 1,2,4-butanetriol trimethacrylate, diethylene glycol diacrylate 1,4-cyclohexanediol, 1,4-cyclohexanediol dimethacrylate, pentaerythritol diacrylate, 1,5-pentanediol dimethacrylate and the like.

[0024] Examples of suitable vinyl monomers may include vinyl aromatic compounds such as styrene or vinyltoluene; vinyl or vinylidene halides such as vinyl chloride or vinylidene fluoride; vinyl ethers such as 1,4-butanediol divinyl ether or cyclohexanedimethanol divinyl ether; or vinyl esters such as vinyl acetate.

[0025] The ethylenically unsaturated monomer of component (iii) can be selected from the group consisting of hexanediol diacrylate, butanediol diacrylate, cyclohexanedimethanol divinyl ether, and mixtures thereof.

[0026] Generally, component (i) is present in the curable composition in an amount ranging from 5 to 90 percent by weight, such as from 10 to 80 percent by weight or from 25 to 70 percent by weight; component (ii) is present in the curable composition in an amount ranging from 5 to 90 percent by weight, such as from 10 to 70 percent by weight or from 25 to 50 percent by weight; and component (iii) is present in the curable composition in an amount ranging from 1 to 50 percent by weight, such as from 2 to 40 percent by weight or from 5 to 25 percent by weight, wherein the weight percentages are based on the total combined weight of components (i), (ii), and (iii).

[0027] The curable compositions of the present invention may further comprise a free radical initiator selected from the group consisting of thermal initiators, photoinitiators, and mixtures thereof. Examples of suitable thermal free radical initiators include, but are not limited to, organic peroxides, such as peroxymonocarbonate esters, such as tertiary butylperoxy isopropyl carbonate; peroxydicarbonate esters, such as di(2-ethylhexyl)peroxydicarbonate, di(secondary butyl)peroxydicarbonate, or diisopropylperoxydicarbonate; diacylperoxides, such as 2,4-dichlorobenzoyl peroxide, isobutyryl peroxide, decanoyl peroxide, lauryl peroxide, propionyl peroxide, acetyl peroxide, benzoyl peroxide, or p-chlorobenzoyl peroxide; peroxyesters, such as t-butylperoxy pivalate, t-butylperoxy octylate or t-butylperoxyisobutyrate; methyl ethyl ketone peroxide, acetylcyclohexane sulfonyl peroxide and mixtures thereof.

[0028] Examples of suitable photoinitiators may include, but are not limited to, haloalkylated aromatic ketones, chloromethylbenzophenones, certain benzoin ethers, and certain acetophenone derivatives, such as dietoxyacetophenone or 2-hydroxy-2-methyl-l-phenylpropan-l-one. Additional examples of free radical photoinitiators include benzyl ketals, which produce rapid cures. Also suitable as photoinitiators are those marketed under the product names IRGACURE™ and DAROCURE™, both available through BASF Corporation. Non-limiting examples include Irgacure 651 (α,α-dimethoxy-α-phenylacetophenone) and Darocure™ 1173 (2-hydroxy-2-methyl-l-phenylpropan-l-one). Specific examples of photoinitiators may include ethylbenzoin ether, isopropylbenzoin ether, dimethoxyphenylacetophenone, dietoxyacetophenone, and benzophenone.

[0029] When an alkoxysilane with epoxy functionality, for example, 3-glycidoxypropyltrimethoxysilane, is used in the curable composition of the present invention (for example, in component (i) and / or component (ii)), the composition may also include a curing agent comprising a cationic initiator. Such cationic initiators may include aromatic onium salts, including salts of Group VA elements, such as phosphonium salts, for example, triphenylphenacylphosphonium hexafluorophosphate; salts of Group VIA elements, such as sulfonium salts, for example, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium hexafluoroantimonate; and salts of Group VIIA elements, such as iodonium salts, such as diphenyliodonium chloride and diarylodonium hexafluoroantimonate.Aromatic onium salts and their use as cationic initiators in the polymerization of epoxy compounds are described in detail in U.S. Patent No. 4,058,401, column 1, line 49 to column 5, line 17, Photocurable Compositions Containing Group VIA Aromatic Onium Salts, by JV Crivello, issued November 15, 1977; U.S. Patent No. 4,069,055 in column 1, line 48 to column 4, line 44, Photocurable Epoxy Compositions Containing Group VA Onium Salts, by J.V. Crivello, issued January 17, 1978; U.S. Patent No. 4,101,513 in column 3, line 51 to column 4, line 68, Catalyst for Condensation of Hydrolyzable Silanes and Storage Stable Compositions Thereof, by F.J. Fox et al., issued July 18, 1978; and U.S. Patent No. 4,161,478 in column 1, line 14 to column 9, line 68, Photoinitiators, by J.V.Crivello, issued on July 17, 1979, whose specified disclosures are incorporated herein by reference.

[0030] Other suitable cationic initiators may be used, such as phenyldiazonium hexafluorophosphates containing alkoxy or benzyloxy radicals as substituents on the phenyl radical, as described in U.S. Patent No. 4,000,115, Column 1, Line 9 to Column 3, Line 41, Photopolymerization of Epoxides, by Sanford S. Jacobs, issued December 28, 1976, the specified disclosures of which are incorporated herein by reference. The preferred cationic initiators for use in the compositions of this invention are the salts of the Group VIA elements, and especially the sulfonium salts, and also the Group VIIA elements, particularly the diarylodonium hexafluoroantimonates.Particular cationic catalysts may include diphenyliodonium salts of tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate; and triphenylsulfonium salts of tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate.

[0031] The curable film-forming composition of the present invention may (optionally) further comprise a polyglycidyl ether, such as a diglycidyl ether and / or a triglycidyl ether. Higher polyglycidyl ethers may also be used. Polyhydric alcohols that may be used to prepare the polyglycidyl ether include, for example, ethylene glycol, propylene glycol, butylene glycol, 1,6-hexylene glycol, neopentyl glycol, diethylene glycol, glycerol, trimethylolpropane, resorcinol, catechol, hydroquinone, and pentaerythritol. Examples of suitable polyglycidyl ethers may include resorcinol diglycidyl ether and trimethylolpropane triglycidyl ether. Combinations of polyglycidyl ethers are also suitable.

[0032] The curable compositions of the present invention may include a variety of optional ingredients and / or additives that depend to some extent on the particular application of the curable composition. For example, the composition may be dyed and contain a colorant. The film-forming curable compositions of the present invention are particularly suitable for dyeing. Other optional ingredients include rheology control agents, surfactants, for example, those commercially available under the trade name BYK, initiators, catalysts, curing inhibitors, reducing agents, acids, bases, preservatives, free radical donors, free radical scavengers, and heat stabilizers, the adjuvant materials of which are known to persons of a mid-level trade.

[0033] As used herein, the term colorant means any substance that imparts color and / or other opacity and / or other visual effect to the composition. The colorant may be added to the coating in any suitable form, such as particles, dispersions, solutions, and / or separate flakes. A single colorant or a mixture of two or more colorants may be used in the compositions of the present invention.

[0034] Example colorants include pigments, dyes, and tints, such as those listed by the Dry Color Manufacturers Association (DCMA), as well as special effect compositions. A colorant may include, for example, a finely divided solid powder that is insoluble but wettable under conditions of use. A colorant may be organic or inorganic and may be agglomerated or non-agglomerated. Colorants may be incorporated into coatings by milling or simple mixing.

[0035] Example pigments and / or pigment compositions may include, but are not limited to, crude carbazole dioxazine pigment, azo, monoazo, disazo, naphthol AS, salt type (lagos), benzimidazolone, condensation, metal complex, isoindolinone, isoindoline and polycyclic phthalocyanine, quinacridone, perylene, perinone, diketopyrrole pyrrole, thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavantrone, pyrantrone, antantrone, dioxazine, triarylcarbonium, quinophthalone pigments, diketopyrrole pyrrole red (DPPBO red), titanium dioxide, carbon black, and mixtures thereof. The term pigment and the expression colored filler may be used interchangeably. κηοαηη / ζζηζ / Ε / γίΛΐ

[0036] Examples of suitable dyes include, but are not limited to, solvent-based and / or aqueous dyes such as acid dyes, azo dyes, basic dyes, direct dyes, disperse dyes, reactive dyes, solvent dyes, sulfur dyes, mordant dyes, e.g., bismuth vanadate, anthraquinone, perylene, aluminum, quinacridone, thiazole, thiazine, azo, indigoid, nitro, nitroso, oxazine, phthalocyanine, quinoline, stilbene, and triphenylmethane.

[0037] The curable compositions of the present invention are especially suitable for use as curable coating compositions. In particular, the curable coating compositions are useful for coating articles, such as optical articles, where the curable coating compositions provide coated substrates, such as optical substrates, that have improved scratch resistance.

[0038] Therefore, the present invention also relates to an article comprising (a) a substrate and (b) a coating on at least a portion of the substrate, wherein the coating is formed from any of the curable compositions described above. In particular, the article is an optical article selected from the group consisting of windows, display elements, mirrors, lenses, active and passive liquid crystal cells, visors, and protective eyewear. The curable composition of the present invention provides a coating on at least a portion of the optical substrate that provides improved scratch resistance. Therefore, the curable compositions of the present invention are particularly suitable for application as scratch-resistant coatings on lenses.

[0039] The curable compositions of the present invention can be applied as a coating to any suitable substrate. For example, the substrate can be a glass substrate, such as crown glass or other optical-grade glass, or a plastic substrate, such as a thermoplastic or thermoset substrate comprising a polymeric organic material.

[0040] Examples of suitable polymeric organic materials that may be used as substrates for the curable composition of the present invention may include polymers of bis(allyl carbonate) monomers, diethylene glycol dimethacrylate monomers, diisopropenylbenzene monomers, ethoxylated bisphenol A dimethacrylate monomers, ethylene glycol bismethacrylate monomers, poly(ethylene glycol) bismethacrylate monomers, ethoxylated phenol bismethacrylate monomers, alkoxylated polyhydric alcohol acrylate monomers, such as ethoxylated trimethylolpropane triacrylate monomers, urethane acrylate monomers, such as those described in U.S. Patent No. 5,373,033 in column 2, line 27 to column 9, line 10, the specified disclosure of which is incorporated herein. by reference, and vinylbenzene monomers, such as those described in U.S. Patent No. 5,475,074 in column 2, line 20 to column 4, line 2,whose specified disclosure is incorporated herein by reference, and styrene; polymers of monofunctional (meth)acrylate monomers, polyfunctional acrylate and / or methacrylate monomers, for example, difunctional or multifunctional, poly(C1-C12 alkyl methacrylates), such as poly(methyl methacrylate), poly(oxyalkylene dimethacrylate), poly(alkoxylated phenol methacrylates), cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), polyurethanes, polythiourethanes, thermoplastic polycarbonates, polyesters, poly(ethylene terephthalate), polystyrene, poly(alpha methylstyrene), copoly(styrenemethylmethacrylate), copoly(styrene-acrylonitone), polyvinylbutyral; olefin polymers,particularly cyclic olefins; polymers of epoxy and / or episulfide monomers; and diallylidide pentaerythritol polymers, particularly copolymers with polyol (allyl carbonate) monomers, for example, diethylene glycol bis(allyl carbonate), acrylate monomers, for example, ethyl acrylate, butyl acrylate, and mixtures thereof. Further examples of polymeric organic materials are disclosed in U.S. Patent No. 5,753,146 in column 8, line 62 to column 10, line 34, the specified disclosure of which is incorporated herein by reference.

[0041] Transparent copolymers and transparent polymer blends are also suitable as substrates. The substrate for the curable composition may be an optically transparent, polymerized organic material prepared from a thermoplastic polycarbonate resin, such as the carbonate-bonded resin derived from bisphenol A and phosgene, marketed under the registered trademark LEXAN; a polyester, such as the material marketed under the trademark MYLAR; or a poly(methyl methacrylate), such as the material marketed under the registered trademark PLEXIGLAS.polymerized from a polyol (allyl carbonate) monomer, especially diethylene glycol bis(allyl carbonate), the monomer of which is sold under the registered trademark CR-39®, and polymerized from copolymers of a polyol (allyl carbonate), for example, diethylene glycol bis(allyl carbonate), with other copolymerizable monomeric materials, such as copolymers with vinyl acetate, for example, copolymers of 80 to 90 percent diethylene glycol bis(allyl carbonate) and 10 to 20 percent vinyl acetate, particularly 80 to 85 percent allyl bicarbonate and 15 to 20 percent vinyl acetate, and copolymers with a polyurethane having terminal diacrylate functionality, as described in U.S. Patent No. 4,360,653 in column 3, line 55 to column 8, line 47, and 4,994,208 in column 4, line 15 to column 7, line 41, whose specified disclosures are incorporated herein by reference;and copolymers with aliphatic urethanes, the terminal portion of which contains groups having allyl or acryloyl functionality, as described in U.S. Patent No. 5,200,483 in column 4, line 66 to column 10, line 65, the specified disclosure of which is incorporated herein by reference; poly(vinyl acetate), polyvinylbutyral, polyurethane, polythiourethanes, polymers of members of the group consisting of diethylene glycol dimethacrylate monomers, diisopropenylbenzene monomers, ethoxylated bisphenol A dimethacrylate monomers, ethylene glycol bismethacrylate monomers, poly(ethylene glycol) bismethacrylate monomers, ethoxylated phenol bismethacrylate monomers and ethoxylated trimethylolpropane triacrylate monomers; cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, polystyrene and copolymers of styrene with methyl methacrylate, vinyl acetate, acrylonitrile and mixtures thereof.

[0042] The substrate may comprise materials of glass, polycarbonate, polyamide, polyurea, polyurethane, poly(urea)urethane, polythiourethane, polythio(urea)urethane, and / or polyol (allyl carbonate), as well as episulfide-derived resin materials. In addition, the substrate may be in the form of a film, such as a meltblown polymer film, comprising cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), poly(ethylene terephthalate), polyester, polyurethane, polythiourethane, polycarbonate, copolymers thereof, and / or mixtures thereof.

[0043] Any of the curable compositions described above of the present invention may be applied to the substrate by using, for example, any conventional coating technique, including flow coating, dip coating, spin coating, roll coating, curtain coating, and spray coating. The coatings formed from the curable compositions of the present invention may vary in thickness from 0.1 to 50 micrometers, such as from 1 to 20 micrometers or from 2 to 10 micrometers, for example, 5 micrometers.

[0044] After the application of the curable composition of the present invention to the substrate, the coating is cured. As used herein, the terms "cure" and "curing" refer to at least partial crosslinking or polymerization of the components of the composition to be cured, i.e., crosslinking or polymerization. The coating may be thermally cured by exposing the coated substrate to elevated temperatures for a time sufficient to effect crosslinking or polymerization of the components. In addition, the coating may be cured by irradiation with infrared, ultraviolet, visible, or electron radiation. When a photoinitiator is present in the curable composition, a coated substrate may be irradiated with infrared, ultraviolet, visible, or electron radiation of sufficient energy to activate the photoinitiator.This photopolymerization can occur as the sole curing method, or it can occur before or after the thermal curing stages, or simultaneously during the thermal curing process. During the irradiation stage, the coated substrate can be kept at room temperature, for example, 22°C to 27°C, or it can be heated to an elevated temperature that is below the temperature at which substrate damage occurs.

[0045] The present invention relates, for example and without limitation, to the following aspects:

[0046] In a first aspect, the present invention relates to a curable composition comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (i) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (iii) an ethylenically unsaturated monomer.

[0047] In a second aspect, the present invention relates to the curable composition as described in the first aspect, wherein component (i) and component (i) are prepared and added separately.

[0048] In a third aspect, the present invention relates to the composition as described in either the first or second aspect, wherein the component (i) comprises at least 30 percent monomeric alkoxysilane.

[0049] In a fourth aspect, the present invention relates to the curable composition as described in any of the first to third aspects, wherein the first alkoxysilane (i) and the second alkoxysilane (i) are the same or different.

[0050] In a fifth aspect, the present invention relates to the curable composition as described in any one of aspects one through four, wherein each of the first alkoxysilane and the second alkoxysilane independently has the following structure (I): (I) RxS¡(OR')4-x where: x is 0, 1, 2 or 3; each R is an organic radical independently selected from Ci to Ce alkyl, vinyl, alkoxyalkyl, aryl, aryloxyalkyl, γ-glycidoxyalkyl or Y-(meth)acryloxyalkyl; and each R' is independently an alkyl group Ci to Q.

[0051] In a sixth aspect, the present invention relates to the curable composition as described in any of aspects one through five, wherein the curable composition further comprises a free radical initiator selected from the group consisting of thermal initiators, photoinitiators, and mixtures thereof.

[0052] In a seventh aspect, the present invention relates to the curable composition as described in the sixth aspect, wherein the free radical initiator is a photoinitiator.

[0053] In an eighth aspect, the present invention relates to the curable composition as described in any of aspects one through seven, wherein: component (i) is present in the curable composition in an amount that varies from 5 to 90 percent by weight; Component (i) is present in the curable composition in an amount ranging from 5 to 90 percent by weight; and component (ii) is present in the curable composition in an amount ranging from 1 to 50 percent by weight, where the weight percentages are based on the total weight of components (i), () and (ii).

[0054] In a ninth aspect, the present invention relates to the curable composition as described in any one of aspects one through eight, wherein each of the first alkoxysilane of component (i) and the second alkoxysilane of component (i) is independently selected from the group consisting of methyltriethoxysilane, y-glycidoxypropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, acryloxysilane and mixtures thereof.

[0055] In a tenth aspect, the present invention relates to the curable composition as described in any of aspects five through nine, wherein R is y-glycidoxyalkyl and the curable composition further comprises a curing agent comprising a cationic initiator.

[0056] In an eleventh aspect, the present invention relates to the curable composition as described in any of aspects one through ten, wherein the curing agent comprises arylonium salts of group VA elements, salts of group VIA elements, salts of group VIIA elements, or mixtures thereof.

[0057] In a twelfth aspect, the present invention relates to the curable composition as described in any one of aspects one through eleven, wherein the ethylenically unsaturated monomer of component (ii) is selected from the group consisting of hexanediol diacrylate, butanediol diacrylate, cyclohexanedimethanol divinyl ether, and mixtures thereof.

[0058] In a thirteenth aspect, the present invention relates to the curable composition as described in any one of aspects one through twelve, wherein the second alkoxysilane of component (i) is 10 to 40 percent hydrolyzed.

[0059] In a fourteenth aspect, the present invention relates to the curable composition as described in any of aspects one through thirteen, wherein the curable composition further comprises a polyglycidyl ether.

[0060] In a fifteenth aspect, the present invention relates to a coating formed from the curable composition as described in any of aspects one through fourteen.

[0061] In a sixteenth aspect, the present invention relates to an article comprising: (a) a substrate; and (b) a coating over at least a portion of the substrate, wherein the coating is formed from the curable composition as described in any one of the first to fourteenth aspects.

[0062] In a seventeenth aspect, the present invention relates to the article as described in the sixteenth aspect, wherein the component (i) of the curable composition comprises at least 30 percent monomeric alkoxysilane.

[0063] In an eighteenth aspect, the present invention relates to the article as described in either the sixteenth or seventeenth aspect, wherein the substrate comprises materials of glass, polycarbonate, polyamide, polyurea, polyurethane, poly(urea)urethane, polythiourethane, polythio(urea)urethane, polyol(allyl carbonate) and / or episulfide-derived resin.

[0064] In a nineteenth aspect, the present invention relates to the article as described in any of the sixteenth to eighteenth aspects, wherein the article is an optical article selected from the group consisting of windows, display elements, mirrors, lenses, active and passive liquid crystal cells, viewers, and protective goggles.

[0065] In a twentieth aspect, the present invention relates to the article as described in any of the sixteenth to nineteenth aspects, wherein the article is a lens.

[0066] The present invention is described more particularly in the following examples, which are intended to be illustrative only, since numerous modifications and variations will be evident to people of average skill. EXAMPLES EXAMPLE 1

[0067] Preparation of Hydrolysis Product 1: A partially hydrolyzed epoxy functional alkoxysilane was prepared by loading 27.3 g of 3-glycidoxypropyltrimethoxysilane into a flask and cooling to 5°C in an ice bath. Then, 2.7 g of a 0.055% aqueous HCl solution was added to the cooled 3-glycidoxypropyltrimethoxysilane, and the ingredients were mixed for 30 minutes, during which time a peak exotherm of 15°C was observed. The volatiles of the resulting hydrolysis product were removed under vacuum. COMPARATIVE EXAMPLE 2

[0068] Preparation of Hydrolysis Product 2: A partially hydrolyzed epoxy functional alkoxysilane was prepared by combining 236 g of 3-glycidoxypropyltrimethoxysilane, 36 g of water and 0.5 mL of a 1% HCl (aqueous) solution at room temperature and mixing for κηοαηη / ζζηζ / E / γίΛΐ 16.25 hours, during which time a peak exotherm of approximately 45°C occurred. The volatiles of the resulting hydrolysis product were removed under vacuum.

[0069] Hydrolysis Product 1 (Example 1) and Hydrolysis Product 2 (Comparative Example 2) were analyzed by Fourier transform infrared spectroscopy (FTIR) to evaluate the percentage of hydrolysis based on hydrolyzable alkoxy groups (see Table 1 below). The theoretical percentage of hydrolysis is given in Table 1 for both Hydrolysis Product 1 (from Example 1) and Hydrolysis Product 2 (from Comparative Example 2) as a function of the stoichiometric ratio of water to hydrolyzable alkoxy groups.

[0070] The percentage monomeric content (as defined herein) of both the Example 1 and Comparative Example 2 products was also verified by GPC to demonstrate that the Example 1 product remains relatively uncondensed (see Table 1 below). The GPC chromatogram of Hydrolysis Product 1 (Example 1) is shown in Figure 1. The GPC chromatogram of Hydrolysis Product 2 (Comparative Example 2) is shown in Figure 2. A comparison of the respective GPC chromatograms demonstrates the difference in molecular weight distribution, which represents the degree of condensation of the hydrolyzed alkoxysilane. For clarity, Figure 3 shows a superimposition of the GPC chromatograms from Figures 1 and 2 relative to the GPC chromatogram of a reference sample of pure, unhydrolyzed 3-glycidoxypropyltrimethoxysilane.

[0071] To support the difference in the percentage monomeric content for Hydrolysis Product 1 (Example 1) and Hydrolysis Product 2 (Comparative Example 2) detected by GPC, nuclear magnetic resonance (NMR) measurements of 29Si were performed to detect, on a molar basis, the relative fraction of completely unhydrolyzed 3-glycidoxypropyltrimethoxysilane species in the product (see Table 1). Importantly, the NMR characterization of 29Si quantifiably shows a high molar fraction of completely unhydrolyzed 3-glycidoxypropyltrimethoxysilane species in Hydrolysis Product 1 (Example 1), compared to Hydrolysis Product 2 (Comparative Example 2), which is consistent with the molecular weight distribution characterized by GPC. κηοαηη / ζζηζ / Ε / γίΛΐ Table 1 Example 1 (Hydrolysis Product 1) Comparative Example 2 (Hydrolysis Product 2) Theoretical Hydrolysis Percentage 40 67 Hydrolysis Percentage 1 30.8 62.3 Monomeric Percentage 2 35.0 5.9 Percentage of Unhydrolyzed Alkoxysilane 3 40.0 8.7 1Fourier transform infrared (FTIR) spectra were collected on a VERTEX 70 FTIR bench (Bruker Corp) using a PIKE MIRacle attenuated total reflectance (ATR) fixture (PIKE Technologies) with a diamond plate. The methoxy CH segment at 2840 cm1 was used to calculate the percent hydrolysis. An unhydrolyzed sample of 3-glycidoxypropyltrimethoxysilane was used as the 0% hydrolysis reference. 2. GPC characterization was performed using a Waters 600E LC, a Waters 2414 refractive index detector, and a PerkinElmer TotalChrom C / S chromatography data system. The column array consisted of 2 x PL Gel 500A, 5 µm, 300 x 7.5 mm columns in series with a mobile phase of 100% tetrahydrofuran (THF, stabilized with butylated hydroxytoluene). The gradient was isocratic, 25 minutes; the flow rate was 1.0 mL / min; the column / detector temperature was 35°C; and the injection volume was 100 pL. The sample preparation was 100 mg / 10 mL of THF. The Mw reference standards were seven polyethylene glycol standards with an Mw range of 10⁶–17,500. The products from Example 1 and Comparative Example 2 were analyzed under GPC conditions identical to those described above. Pure, monomeric, non-hydrolyzed 3-glycidoxypropyltrimethoxysilane was also analyzed by GPC to determine the retention time of the monomeric material.The peak corresponding to the retention time of the unhydrolyzed alkoxysilane reagent was integrated on the basis of the area to obtain the relative amount of monomeric material. Monomeric percentage = [(integrated area, monomeric) f (total integrated area)] x 1003. The unhydrolyzed alkoxysilane content was determined by de29S1 NMR. de29S1 NMR was performed on a 500 MHz magnet with a carrier frequency of 99.4 MHz. Approximately 200 mg of sample were dissolved in CDCi3. Chromium(III) acetylacetonate (Cr(AcAc)3) dissolved in CDCh3 was added to the sample to serve as a relaxing agent. de29S1 NMR spectra were recorded by acquiring 2048 scans with a recycle delay of 6 s. A sample of pure, unhydrolyzed 3-glycidoxypropyltrimethoxysilane was analyzed by de29S1 NMR to determine the chemical shift of the unhydrolyzed material, which is approximately -42 ppm. This sample of unhydrolyzed 3-glycidoxypropyltrimethoxysilane was then compared with the samples from Example 1 and Comparative Example 2, in which there may be various states of hydrolysis.These different hydrolysis states have 29S resonances in the following regions: -72 to -63, -62 to -56, -52 to -47, -41 to -35, and -23 to -21 ppm. These chemical shift ranges can be integrated with a single integration or with several integrations within the region. To calculate the relative molar percentage of unhydrolyzed 3-glycidoxypropyltrimethoxysilane in the sample, the following equation was used: Σ Integration of non-hydrolyzed Percentage of unhydrolyzed alkoxysilane = —-------------------—-— --------—-— ---— 2. Integrations of non-hydrolyzed and hydrolyzed components EXAMPLE 3

[0072] Preparation of Coating Compositions: Four coating compositions, labeled Coating A, Comparative Coating B, Coating C, and Comparative Coating D respectively in Table 2 below, were prepared by mixing the indicated ingredients, where the quantities are given in parts by weight. The compositions were spin-coated onto lenses prepared from CR39® monomer (commercially available from PPG Industries, Inc.) and cured using a Type D ultraviolet curing lamp (300 W / in; 4.13 / cm2UVA, as measured with an EIT® UV Power Puck® II).

[0073] The surface abrasion resistance of the resulting coated substrates was evaluated using a Bayer Abrasion Tester. The abrasion resistance of the coated substrate was quantified by measuring the turbidity of the test sample after abrasion and comparing that value to that measured on a control sample, i.e., a flat lens prepared from CR-39® monomer. Measurements were performed on multiple pairs of test / control samples, e.g., 5 pairs, to ensure statistically significant results. The samples and controls to be evaluated were cleaned with mild soapy water, rinsed with water, and then air-dried. The test samples and controls were conditioned for approximately 2 hours. The percentage turbidity of the test and control samples was measured using an UltraScan Pro spectrophotometer (HunterLab).The test and control samples were mounted in the Bayer Abrader, and the abrasion medium was placed in the Abrader tray. The Abrader was run for 4 minutes at a rate of 150 cycles per minute for a total of 600 cycles. The samples and controls were cleaned with mild soapy water, rinsed, and air-dried. The turbidity of the test and control samples was measured again using the UltraScan Pro spectrophotometer. The turbidity gain was calculated from the difference in turbidity before and after abrasion. The reported Bayer ratio was calculated by dividing the measured turbidity of the control by that of the test sample. Bayer ratio = turbidity gain (control) / turbidity gain (test sample). κηοαηη / ζζηζ / Ε / γίΛΐ Table 2 Coating compositions Component A Comparative BC Comparative D Hydrolysis Product 1 (Example 1) 9.828 - 5.495 - Hydrolysis Product 2 9.825 - 5.516 (Comparative Example 2) 3-Glycidoxypropyltrimethoxysilane 13.313 13.301 5.002 4.997 Hexanediol diacrylate 4.915 4.902 - - Butanediol diacrylate - - 7.998 7.999 2-Hydroxy-2-methylpropiophenone 1.123 1.133 1.122 1.171 Diphenyliodonium hexafluorophosphate 1.958 1.968 1.957 1.962 BYK-3071 0.145 0.156 0.139 0.166 Cyclohexanedimethanol divinyl ether - - 2.005 2.013 Trimethylolpropane triglycidyl ether - - 7.497 7.501 Bayer ratio (compared to 1.83 3.08 1.98 with CR-39®uncoated)1A silicone-containing surface additive available through BYK.

[0074] The results presented above in Table 2 clearly demonstrate the improvement in scratch resistance, as shown by the improved Bayer ratio for Inventive Coating Compositions A and C compared to Comparative Coating Compositions B and D with higher hydrolysis levels and lower monomeric alkoxysilane compositions.

[0075] Persons of average skill will readily appreciate that modifications to the invention can be made, as indicated above, without departing from the concepts disclosed in the preceding description. Accordingly, the particular embodiments described in detail herein are merely illustrative and do not limit the scope of the invention, which is fully expressed in the appended claims and all their equivalents.

Claims

NOVELTY OF THE INVENTION CLAIMS 1. A curable composition comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (ii) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (iii) an ethylenically unsaturated monomer.

2. The curable composition according to claim 1, wherein component (i) and component (i) are prepared and added separately.

3. The curable composition according to claim 1 or 2, wherein component (i) comprises at least 30 percent monomeric alkoxysilane.

4. The curable composition according to any of claims 1 to 3, wherein the first alkoxysilane and the second alkoxysilane are the same or different.

5. The curable composition according to any of claims 1 to 4, wherein each of the first alkoxysilane and the second alkoxysilane independently has the following structure (I): (I) RxS¡(OR')4-x wherein: x is 0, 1, 2 or 3; each R is an organic radical independently selected from Ci to Ce alkyl, vinyl, alkoxyalkyl, aryl, aryloxyalkyl, y-glycidoxyalkyl or Y-(meth)acryloxyalkyl; and each R' is independently an alkyl group Ci to Q.

6. The curable composition according to any of claims 1 to 5, further comprising a free radical initiator selected from the group consisting of thermal initiators, photoinitiators, and mixtures thereof.

7. The curable composition according to claim 6, wherein the free radical initiator is a photoinitiator.

8. The curable composition according to any one of claims 1 to 7, wherein: component (i) is present in the curable composition in an amount ranging from 5 to 90 percent by weight; component (ii) is present in the curable composition in an amount ranging from 5 to 90 percent by weight; and component (ii) is present in the curable composition in an amount ranging from 1 to 50 percent by weight, wherein the weight percentages are based on the total weight of components (i), (ii) and (ii).

9. The curable composition according to any one of claims 1 to 8, wherein each of the first alkoxysilane of component (i) and the second alkoxysilane of component (i) is independently selected from the group consisting of methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, acryloxysilane and mixtures thereof.

10. The curable composition according to any of claims 5 to 9, wherein R is γ-glycidoxyalkyl and the curable composition further comprises a curing agent comprising a cationic initiator.

11. The curable composition according to claim 10, wherein the curing agent comprises arylonium salts of the group VA elements, salts of the group VIA elements, salts of the group VIIA elements or mixtures thereof.

12. The curable composition according to any one of claims 1 to 11, wherein the ethylenically unsaturated monomer of component (iii) is selected from the group consisting of hexanediol diacrylate, butanediol diacrylate, cyclohexanedimethanol divinyl ether, and mixtures thereof.

13. The curable composition according to any of claims 1 to 12, wherein the second alkoxysilane of component (i) is 10 to 40 percent hydrolyzed.

14. The curable composition according to any of claims 1 to 13, further comprising a polyglycidyl ether.

15. A coating formed from the curable composition according to any of claims 1 to 14.

16. An article comprising: (a) a substrate; and (b) a coating on at least a portion of the substrate, wherein the coating is formed from a curable composition comprising the following components: (i) a first alkoxysilane that is not hydrolyzed; (ii) a second alkoxysilane that is 5 to 45 percent hydrolyzed; and (ii) an ethylenically unsaturated monomer.

17. The article according to claim 16, wherein component (i) comprises at least 30 percent monomeric alkoxysilane.

18. The article according to claim 16 or 17, wherein the substrate (a) κηοαηη / ζζηζ / Ε / γίΛΐ comprises glass materials, polycarbonate, polyamide, polyurea, polyurethane, poly(urea)urethane, polythiourethane, polythio(urea)urethane, polyol(allyl carbonate) and / or resin derived from episulfide.

19. The article according to any of claims 16 to 18, wherein the article is an optical article selected from the group consisting of windows, display elements, mirrors, lenses, active and passive liquid crystal cells, viewfinders, and protective goggles.

20. The article according to claim 19, wherein the optical article is a lens.