MXPA01006212A - Aminoplast resin photochromic coating composition and photochromic articles - Google Patents

Abstract

Described are articles having an aminoplast resin photochromic coating prepared from an aminoplast resin, component(s) having hydroxyl functional groups and photochromic substances. The coatings exhibit a Fischer microhardness of from 45 to 180 Newtons per mm2 and desirable photochromic properties, i.e., the formation of darker activated colors and faster rates of photochromic activation and fade when irradiated with ultraviolet light. Also described are photochromic aminoplast resin articles.

Description

COMPOSITION OF PHOTOCRO ICO RESIN OF AMINOPLASTIC RESIN AND PHOTOCROMIC ARTICLES DESCRIPTION OF THE INVENTION The present invention relates to coatings comprising an aminoplast resin, components having two hydroxyl functional groups and photochromic substances, referred to herein as photochromic aminoplast resin coatings. In particular, this invention relates to articles coated with such photochromic coatings and photochromic, i.e., polymerized, articles made from such polymerizable compositions. More particularly, this invention relates to certain photochromic aminoplast resin coatings which, when present in a substrate and exposed to activating light radiation, exhibit improved photochromic properties. In addition, this invention relates to photochromic aminoplast resin coatings that meet commercially acceptable "cosmetic" standards for optical coatings applied to optical elements, eg, lenses. Photochromic compounds show a reversible change in color when exposed to light radiation that involves ultraviolet rays, such as ultraviolet radiation in sunlight or light from a mercury lamp. Various classes of photochromic compounds have been synthesized and have been suggested for use in applications where a color change or reversible darkening induced by sunlight is desired. The most widely described classes of photochromic compounds are oxazines, pyranos and fulgida. The use of melamine resins as a potential matrix for photochromic compounds in multi-layer articles has been described in U.S. Patent 4,756,973 and Japanese Patent Applications 62-226134, 3-2864, 3-35236. In U.S. Patent 4,756,973 and JP 62-226134, the melamine resin is referred to herein as a list of several different materials, but specific examples of melamines and reagents are not disclosed to produce photochromic coatings. JP 3-2864 and 3-35236 describe examples of melamine photochromic coatings, but the information needed to duplicate these examples is not included in the applications. JP 61-268788 discloses a photochromic coating composition consisting of spironaphthoxazine, melamine condensed with polyol and a polymer or copolymer of a vinyl compound containing a hydroxyl group. The comparative examples 6-10 herein represent the examples of JP 61-268788. Lenses prepared with the coatings of Comparative Examples 6-10 demonstrate cosmetic defects or have performance properties outside the desired range. The photochromic aminoplast coatings prepared with the examples of the present invention are prepared by mixing all of the ingredients together instead of using the additional step of JP61-2687888, which is to condense a polyol with a melamine resin before adding the other ingredients . It has now been discovered that photochromic aminoplast resin coatings can be produced which exhibit good photochromic properties, i.e., color and fade at acceptable rates and obtain a sufficiently dark color state and which satisfy the "cosmetic" optical coating standards. Such coatings allow the production of photochromic articles using plastics in which the photochromic compounds do not work properly, and avoids the use of thermal transfer processes. The novel coatings described herein show a Fischer microhardness of at least 45 to 180 Newtons per mm 2. The articles of the present invention having this hardness range are suitable for handling by automated process equipment without being damaged. The photochromic aminoplast coating composition used to form the photochromic coating can also be used to form a photochromic aminoplast resin polymer.

DETAILED DESCRIPTION OF THE INVENTION In recent years, photochromic articles, particularly photochromic plastic materials for optical applications, have received considerable attention. In particular, photochromic ophthalmic plastic lenses have been investigated because they offer an advantage in terms of weight compared to glass lenses. In addition, photochromic transparencies for vehicles such as automobiles and airplanes have been of interest due to their potential safety features offered by such transparencies. The photochromic articles that are most useful are those in which the photochromic compounds associated with the article show a highly activated intensity and acceptable coloration and fading rates. The use of photochromic coatings allows the preparation of photochromic plastic articles without the need to incorporate the photochromic compounds into the plastic substrate. This is advantageous when the plastic, for example thermoplastic polycarbonate, does not have sufficient internal free volume or polymer chain flexibility for the photochromic compounds incorporated in the plastic to function properly. In addition, the use of photochromic coatings results in a more efficient use of photochromic compounds. Losses associated with more conventional transfer methods, for example imbibition or permeation, as well as costs associated with the disposal of spent photochromic dye solutions are avoided. In addition to the operation examples, or when indicated otherwise, all values such as those expressing wavelengths, ingredient amounts, ranges or reaction conditions, used in this description and in the appended claims should be considered modified. , in all cases, by the term "approximately". When the coating compositions of the present invention are applied as a coating and cured, the coating exhibits a Fischer microhardness of at least 45 Newtons per mm 2, preferably at least 55, and more preferably at least 60. Newtons per mm2. Typically, the cured coating exhibits a Fischer microhardness no greater than 180 Newtons per mm 2, preferably no greater than 160 and much more preferably no greater than 150 Newtons per mm 2. The Fischer microhardness of the coating can vary between any combination of these values, inclusive, of the aforementioned range.

The photochromic properties of the cured coating of the present invention are characterized by an? OD after 30 seconds of at least 0.15, preferably of at least 0.16 and much more preferably of at least 0.17 and a? OD, after 8 minutes of at least 0.47, preferably 0.50 and much more preferably at least 0.55. The photochromic properties are also characterized by a bleaching rate of not more than 180 seconds, preferably not more than 140, and more preferably not more than 100 seconds - all measured at 29.4 ° C (85 ° F) and as described in part D of example 16 herein. Aminoplast resin coatings having a microhardness and photochromic performance properties within the ranges set forth above can be made by balancing the amounts of the components of the crosslinkable composition used to prepare the coating matrix. For example, the specific properties of the components comprising the coating matrix or the polymerization that will alter the microhardness and the photochromic performance properties of the aminoplast resin matrix are the vitreous transition temperature and the molecular weight of the components, as well as the crosslink density of the resulting matrix. Generally, using components that have vitreous transition temperatures and higher molecular weights, result in polymerized coatings that have an increased microhardness, and vice versa. An increase in the number of reactive groups of a component will also cause an increase in microhardness, with the condition that all the groups react. In the latter case, the increase in the number of reactive groups, i.e., crosslinking sites, increases the density of the cured coating. However, it is considered that the harder the coating or the polymerized, the lower the operation of the photochromic compound contained therein will be. The contribution of a particular component, for example a hydroxyl functional component such as an organic polyol, either to easily determine the hardness or smoothness of the coating measured by the Fischer microhardness of the resulting aminoplast resin coating. The hardness producing component, as defined herein, is a component that increases the microhardness of the aminoplast resin coating as its concentration increases. Similarly, the softness producing component, as defined herein, is a component that decreases the microhardness of the aminoplast resin coating as its concentration increases. Examples of hardness producing organic polyols include, but are not limited to low molecular weight polyols, amide-containing polyols, polyvinyl polyhydric alcohols, for example poly (vinylphenol), epoxy polyols and polyacrylic polyols. Organic polyols that produce softness include, but are not limited to polyester polyols, urethane polyols and polyether polyols, for example polyoxyalkylenes and poly (oxytetramethylene) diols. All of the polyols mentioned above are defined in the following. The photochromic coating composition of the present invention can be prepared by combining a photochromic component with the reaction product of the hydroxyl functional component or components having at least two functional groups and an aminoplast resin, i.e., a crosslinking agent. The coating composition may also include a catalyst. Solvents may also be present in the coating composition. However, as described herein, solvents are not manufactured in weight and percent by weight ratios, as set forth herein. All weight and percent by weight ratios used herein are based on the total solids in the coating composition, unless stated otherwise. Typically, the component having a plurality of functional groups of the present invention is a film-forming polymer, but a component which is not a film-forming polymer can be used. However, it is necessary that at least the combination of the aminoplast resin component with the component having a plurality of groups results in a crosslinked polymer coating. The component or components that contain a functional group is referred to in the following as the functional component has at least two pendant or terminal groups that are selected from hydroxyl. The component having such functional groups can be a monomer, polymer, oligomer or mixture thereof. Preferably, the component is a polymer or oligomer such as an acrylic polymer, a polyester polymer or oligomer, or a bleach of two or more of these materials. Preferred materials are acrylic polymers or oligomers. The acrylic materials of the functional component are copolymers of one or more alkyl esters of acrylic acid or methacrylic acid and, functional components of hydroxyl and optionally, one or more additional polymerizable ethylenically unsaturated monomers. Suitable alkyl esters of acrylic or methacrylic acids, ie, alkyl esters of (meth) acrylic acids, having from one to 17 carbon atoms in the alkyl group, include methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Suitable copolymerizable ethylenically unsaturated monomers include vinyl aliphatic compounds; vinyl aromatic compounds, monomers of (meth) acrylamidobutyraldehyde and dialkyl acetal such as acrylamidobutyraldehyde diethyl acetal (ABDA) and methacrylamidobutyraldehyde diethyl acetal (MABDA) as monomers; (meth) poly (alkylene glycol) acrylate, for example methoxypolyethylene glycol monomethacrylate; nitriles such as ^ acrylonitrile and methacrylonitrile; vinyl and vinylidene halides; vinyl esters; comonomers with acid functionality such as acrylic and methacrylic acid; and mixtures of such ethylenically unsaturated monomers. A further description of the selected ethylenically unsaturated monomers which are included in the following in relation to the preparation of polyacrylic polyols. The hydroxyl functional components can be copolymerized with the acrylic monomers to prepare the functional component of the present invention include, but are not limited to (a) low molecular weight polyols, ie, polyols having an average lower molecular weight weight of 500, for example diols such as diols, triols and aliphatic polyhydric alcohols of 2 to 10 carbon atoms; (b) polyester polyols; (c) polyether polyols; (d) polyols containing amide; (e) polyacrylic polyols; (f) polyvinyl polyhydric alcohols; (g) epoxy polyols; (h) urethane polyols; e (i) mixtures of such polyols. Preferably, the organic polyols are selected from the group consisting of low molecular weight polyols, polyacrylic polyols, polyether polyols, polyester polyols and mixtures thereof. More preferably, the organic groups are selected from the group consisting of polyacrylic polyols, polyester polyols, polyether polyols and mixtures thereof, and much more preferably polyacrylic polyols, polyether polyols and mixtures thereof. As used herein, the term "polyol" means including materials that include at least two hydroxyl groups. Examples of low molecular weight polyols that can be used in the coating composition of the present invention include: tetramethylolmethane, ie, pentaerythritol; trimethylolethane; trimethylolpropane; di (trimethylolpropane), dimethylolpropionic acid; 1,2-ethanediol, that is, ethylene glycol; 1,2-propanediol, that is, propylene glycol; 1,3-propanediol; 2, 2-dimethyl-1,3-propanediol, i.e., neopentyl glycol; 1, 2, 3-propanotriol, ie, glycerin; 1,2-butanediol; 1,4-butanediol; 1,3-butanediol; 1, 2,4-butanetriol; 1, 2, 3, 4-butanotetrol; 2, 2, 4-trimethyl-l, 3-pentanediol; 1,5-pentanediol; 2,4-pentanediol; 1,6-hexanediol; 2,5-hexanediol; 1, 2, 6-hexanotriol; 2-methyl-1,3-pentanediol; 2,4-heptanediol; 2-ethyl-l, 3-hexanediol; 1,4-cyclohexanediol; 1- (2,2-dimethyl-3-hydroxypropyl) -2,2-dimethyl-3-hydroxypropionate; hexahydric alcohol, that is, sorbitol; diethylene glycol; dipropylene glycol; 1,4-cyclohexanedimethanol; 1,2-bis (hydroxymethyl) cyclohexane; 1,2-bis (hydroxyethyl) -cycothexane; bishydroxypropylhydantoins; TMP / epsilon-caprolactone triols; hydrogenated bisphenol A; tris hydroxyethyl isocyanurate; the alkoxylation product of 1 mole of 2,2-bis (4-hydroxyphenyl) propane (ie, bisphenol-A) and 2 moles of propylene oxide; ethoxylated or propoxylated trimethylolpropane or pentaerythritol having an average number of molecular weight less than 500, and mixtures of such low molecular weight polyols. Polyester polyols are known and can have an average number of molecular weight in the range of 500 to 10,000. They are prepared by conventional techniques using diols, triols and low molecular weight polyhydric alcohols known in the art, including but not limited to low molecular weight polyols previously described (optionally in combination with monohydric alcohols) with polycarboxylic acids. Examples of suitable polycarboxylic acids for use in the preparation of polyesters include: phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, tetrachlorophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, succinic acid , glutaric acid, fumaric acid, chlordenedic acid, trimellitic acid, tricarballylic acid and mixtures thereof. The anhydrides of the above acids, when they exist, can also be used. In addition, certain materials which react in a manner similar to acids to form polyester polyols are also useful. Such materials include lactones, for example caprolactones, propiolactone and butyrolactone, and hydroxy acids such as hydroxycaproic acid and dimethylolpropionic acid. If a triol or polyhydric alcohol is used, a monocarboxylic acid, such as acetic acid or benzoic acid may be used in the preparation of the polyester polyols and for some purposes, such a polyester polyol may be desirable. Further, it is understood that the polyester polyols herein include polyester polyols modified with fatty acids or fatty acid glyceride oils (i.e., conventional alkyd polyols containing such modification). Another polyester polyol which can be used is one prepared by reacting an alkylene oxide, for example ethylene oxide, propylene oxide, etc. and the glycidyl esters of versatic acid with methacrylic acid to form the corresponding ester. Polyether polyols are known and can have an average number of molecular weight in the range of 500 to 10,000. Examples of polyether polyols include various polyoxyalkylene polyols, polyalkoxylated polyols having an average number of molecular weight greater than 500, for example poly (oxytetramethylene) diols, and mixtures thereof.

The polyoxyalkylene polyols can be prepared, according to well-known methods, by condensing alkylene oxide, or a mixture of alkylene oxides using an acid or base catalyzed addition, with a polyhydric initiator or a mixture of polyhydric initiators such as ethylene glycol , propylene glycol, glycerol, sorbitol and the like. Illustrative alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, for example 1,2-butylene oxide, amylene oxide, aralkylene oxide, for example styrene oxide and halogenated alkylene oxides such as trichlorobutylene and so on. The most preferred alkylene oxides include butylene oxide, propylene oxide and ethylene oxide or a mixture thereof using random or stepwise oxyalkylation. Examples of such polyoxyalkylene polyols include polyoxyethylene, ie, polyethylene glycol, polyoxypropylene, i.e., polypropylene glycol and polyoxybutylene, i.e., polybutylene glycol. The average molecular number of such polyoxyalkylene polyols used as the soft segment is equal to or greater than 600, more preferably equal to or greater than 725, and more preferably, equal to or greater than 1000. The polyether polyols also include the known poly (oxytetramethylene) diols prepared by the polymerization of tetrahydrofuran in the presence of Lewis acid catalysts such as boron trifluoride, tin (IV) chloride and sulfonyl chloride. The average number of molecular weight of poly (oxytetramethylene) diols used as a soft segment ranges from 500 to 5000, preferably from 650 to 2900, more preferably from 1000 to 2000, and much more preferably from 1000. Polyalkoxylated polyols having an average number of molecular weight greater than 500 can be represented by the following general formula I, where m and m are each a positive number, the sum of m and n is from 5 to 70, R and R2 are each hydrogen, methyl or ethyl, preferably hydrogen or methyl, and A is a divalent linking group selected from the group consisting of straight or branched chain alkylene (usually containing 1 to 8 carbon atoms), phenylene, phenylene substituted with alkyl of 1 to 9 carbon atoms and a group represented by the following general formula II, II wherein R3 and R4 are each alkyl of 1 to 4 carbon atoms, chlorine or bromine, p and q are each an integer from 0 to 4, B represents a divalent benzene group or a divalent cyclohexane group, and D is O, S, -S (02) -, -C (0) -, -CH2-, -CH = CH-, -C (CH3) 2-, • C (CH3) (C6H - or when is a divalent benzene group and D is 0, S, -CH2-, or -C (CH3) 2- when it is a divalent cydohexane group. Preferably, the polyalkoxylated polyol is one in which the sum of m and n is from 15 to 40, for example from 25 to 35, R x and R 2 are each hydrogen and A is a divalent linking group, according to general formula II , where represents a divalent benzene group, p and q are each 0, and D is -C (CH3) 2-, and much more preferably, the sum of m and n is from 25 to 35, for example 30. Such materials can be prepared by methods which are well known in the art. One such commonly used method involves reacting a polyol, for example, 4,4'-isopropylidenediphenol, with an oxirane-containing substance, for example ethylene oxide, propylene oxide, debut ileum oxide or β-butylene oxide, to form what is commonly referred to as an ethoxylated, propoxylated or butoxylated polyol having hydroxy functionality. Examples of suitable polyols for use in the preparation of polyalkoxylated polyols include the low molecular weight polyols described herein; f-enylenediols such as ortho, meta and para-dihydroxybenzene; alkyl-substituted enylendiols such as 2,6-dihydroxytoluene, 3-methylcatechol, 4-methylcatechol, 2-hydroxybenzyl alcohol, 3-hydroxybenzyl alcohol and 4-hydroxybenzyl alcohol; dihydroxybifinyl such as 4,4'-dihydroxybifinyl and 2,2'-dihydroxybifinyl; bisphenols such as 4,4'-isopropylidenediphenol; 4,4'-oxybisphenol; 4,4'-dihydroxybenzeneenone; 4, 4 '-thiobisf enol; phenolphthalein; bis (4-hydroxy-enyl) methane; 4, 4 '- (1,2-ethenediyl) bisfol; and 4,4'-sulfonylbisfolol; halogenated bisphenols such as 4,4'-isopropylidenebis (2,6-dibromofenol), 4,4 '-is op r op i 1 i denob is (2, 6-di c 1 or of ene 1) and 4, 4 '-isopropylidenebis (2, 3, 5, 6-tetrachlorophenol); and biscyclohexanols, which can be prepared by hydrogenating the corresponding bisphenols such as 4,4'-isopropylidenebiscyclohexanol, 4,4'-oxybiscyclohexanol; 4,4'-thiobiscyclohexanol; and bis (4-hydroxycyclohexanol) methane.

Preferably, the polyether polyols are selected from the group consisting of polyoxyalkylene polyols, polyalkoxylated polyols, poly (oxytetramethylene) diols, and mixtures thereof, and more preferably, polyoxyalkylene polyols having an average number of molecular weight or the like. greater than 1,000, ethoxylated bisphenol A having about 30 ethoxy groups, poly (oxytetramethylene) diols having an average number of molecular weight of 1000 and mixtures thereof. Polyols containing amide are known and are typically prepared from the reaction of diacids or lactones and low molecular weight polyols described herein with diamines or amino alcohols as described in the following. For example, polyols containing amide can be prepared by the reaction of neopentyl glycol, adipic acid and hexamethylenediamine. Polyols containing amide can also be prepared by aminolysis by the reaction, for example, of carboxylates, carboxylic acids or lactones with aminoalcohols. Examples of suitable diamines and aminoalcohols include hexamethylenediamines, ethylenediamines, phenylenediamine, monoethanolamine, diethanolamine, isophorone diamine, and the like. Polyvinyl polyhydric alcohols are known and can be prepared, for example, by the polymerization of vinyl acetate in the presence of suitable initiators followed by hydrolysis of at least a portion of the acetate portions. In the hydrolysis process, hydroxyl groups are formed which bind directly to the polymeric backbone. In addition to the homopolymers, vinyl acetate copolymers and monomers such as vinyl chloride can be prepared and similarly hydrolyzed to form copolymers of polyvinyl alcohol polyvinyl chloride. Also included in this group are poly (vinylphenol) polymers and copolymers of poly (vinylphenols) which can be synthesized by vinyl polymerization of p-vinylphenol monomers. Epoxy polyols are known and can be prepared, for example, by the reaction of glycidyl ethers of polyphenols such as diglycidyl ether of 2,2-bis (4-hydroxyphenyl) panthenol, with polyphenols such as 2,2-bis ( 4-hydroxyphenyl) propane. Epoxy polyols of variable molecular weights and average hydroxyl functionality can be prepared depending on the ratio of the initial materials used. Urethane polyols are known and can be prepared, for example, by reacting a polyisocyanate with an excess of organic polyol to form a hydroxyl functional product. Examples of polyisocyanates useful in the preparation of urethane polyols include toluene-2,4-diisocyanate; toluene-2,6-diisocyanate; diphenylmethane-4,4'-diisocyanate; diphenylmethane-2,4 '-diisocyanate; para-phenylene diisocyanate, biphenyl diisocyanate; 3,3'-dimethyl-4,4'-diphenylene diisocyanate; tetramethylene-1,4-diisocyanate; hexamethylene-1,6-diisocyanate; 2,2,4-trimethylhexane-1,6-diisocyanate; lysine methyl ester diisocyanate; bis (isocyanatoethyl) fumarate; isophorone diisocyanate; ethylene diisocyanate; dodecane-1, 12-diisocyanate; Cyclobutane-1,3-diisocyanate; cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; methylcyclohexyl diisocyanate; bicyclohexylmethane diisocyanate; hexahydrotoluene-2,4-diisocyanate; hexahydrotoluene-2,6-diisocyanate; hexahydrophenylene-1,3-diisocyanate; hexahydrophenylene-1,4-diisocyanate; isocyanates of polymethylenepolyphenol, perhydrodiphenylmethane-2,4'-diisocyanate; perhydrodiphenylmethane-, 4'-diisocyanate, and mixtures thereof. Examples of organic polyols useful in the preparation of urethane polyols include hydroxyl-terminated butadiene homopolymers, and the other polyols described herein, for example low molecular weight polyols, polyester polyols, polyether polyols, amide-containing polyols , polyacrylic polyols, polyvinyl polyhydric alcohols and mixtures thereof. The polyacrylic polyols are known and can be prepared by polymerization techniques by addition of free radicals of the monomers described in the following.

Preferably, such polyacrylic polyols have an average molecular weight weight of 500 to 50,000 and a hydroxyl number of 20 to 270. More preferably, the average molecular weight is from 1,000 to 30,000 and the hydroxyl number is 80. to 250. More preferably, the average molecular weight is from 3,000 to 20,000 and the hydroxyl number is from 100 to 225. Polyacrylic polyols include, but are not limited to, the known hydroxyl-functional addition polymers and acid copolymers acrylic and methacrylic; their ester derivatives including, but not limited to their hydroxyl functional ester derivatives. Examples of hydroxyl-functionalized ethylenically unsaturated monomers used in the preparation of the hydroxyl-functional addition polymers include hydroxyethyl (meth) acrylate, ie, hydroxyethyl acrylate and hydroxyethyl methacrylate, hydroxypropyl (meth) acrylate, ( met) hydroxybutyl acrylate, hydroxymethylethyl acrylate, hydroxymethylpropyl acrylate and mixtures thereof. More preferably, the polyacrylic polyol is a copolymer of ethylenically unsaturated ethylenically unsaturated (meth) acrylic monomers and other ethylenically unsaturated monomers which are selected from the group consisting of vinyl aromatic monomers, for example styrene, α-methylstyrene, t-butyl styrene and vinyltoluene; vinyl aliphatic monomers such as ethylene, propylene and 1,3-butadiene; (meth) acrylamide; (meth) acrylonitrile; vinyl and vinylidene halides; for example vinyl chloride and vinylidene chloride; vinyl esters, for example vinyl acetate; alkyl esters of acrylic and methacrylic acids having from 1 to 17 carbon atoms in the alkyl group including methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) asrilate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate and lauryl (meth) asrilate; ethylenically unsaturated monomers with epoxy functionality such as glycidyl (meth) acrylate; ethylenically unsaturated monomers with carboxy functionality such as acrylic and methacrylic acids, and mixtures of such ethylenically unsaturated monomers. The hydroxyl-functionally ethylenically unsaturated (meth) acrylic monomers or monomers may comprise up to 95% by weight of the polyacrylic polyol copolymer. Preferably, it comprises up to 70% by weight, and more preferably, the ethylenically unsaturated (meth) acrylic monomer (s) with hydroxyl functionality comprises up to 45% by weight, for example, 40% by weight of the total copolymer. The polyacrylic polyols described herein may be prepared by addition polymerization initiated by free radicals of the monomer or monomers and by organic solution polymerization techniques. The monomers are typically dissolved in an organic solvent or mixture of solvents including ketones such as methyl ethyl ketones, esters such as butyl acetate, propylene glycol acetate and hexyl acetate, alcohols such as ethanol and butanol, ethers such as propylene glycol monopropyl ether and ethyl-3-ethoxypropionate, and aromatic solvents such as xylene and SOLVESSO 100, a mixture of high boiling point hydrocarbon solvents available from Exxon Chemical Co. The solvent is first heated to reflux, usually 70 to 160 ° C, and the monomer or a mixture of monomers and the free radical initiator is added slowly to the refluxing solvent, for a period of about 1 to 7 hours. Adding the monomers too quickly can result in poor conversion or a rapid high exothermic reaction, which is dangerous to health. Suitable initiators for free radicals include t-amyl peroxyacetate, di-t-amyl peroxyacetate and 2,2'-azobis (2-methylbutanonitrile). The free radical initiator is typically present in the reaction mixture from 1 to 10%, based on the total weight of the monomers. The polymer prepared by the processes described herein does not gel or remain ungelled and preferably has an average molecular weight weight of 500 to 50,000 grams per mole.

The molecular weight of the hydroxyl-functional components suitable for the preparation of compositions of the invention can vary within wide limits based on the nature of the specific classes of polyols that are selected. Typically, the average number of molecular weight of the suitable polyols may vary from 62 to 50,000, preferably from 1,000 to 20,000, and the hydroxyl equivalent weight may vary from 31 to 25,000, preferably from 500 to 10,000. The molecular weights of the hydroxyl group-containing polymers are determined by gel permeation chromatography using a polystyrene standard. The acrylic materials, ie polymers of the component containing the functional group can be prepared by the free radical polymerization methods mentioned above and which are described in relation to the polyacrylic polyols or by solution polymerization technique, in the presence of suitable catalysts. Such catalysts are organic peroxides or azo compounds, for example, benzoyl peroxide or N, N-azobis (isobutyronitrile). The polymerization can be carried out in an organic solution in which the monomers are soluble by techniques conventional in the art. Alternatively, the acrylic polymer can be prepared by aqueous emulsion or by dispersion polymerization techniques well known in the art.

The acrylic polymer typically has an average molecular weight weight from about 500 to 50,000, preferably from about 1,000 to 30,000, as determined by gel permeation chromatography using a polystyrene standard, and an equivalent weight of less than 5,000, preferably within of the range from 140 to 2500, based on the equivalents of the reactive or terminal hydroxyl, carbamate, urea terminal groups or combinations of such functional groups. The equivalent weight is a calculated value that is based on the relative amounts of the various ingredients that are used to make the acrylic material and is based on the solids of the acrylic material. Polyesters can also be used in the formulation of the functional component in the coating composition and can be prepared by the polyesterification of a polycarboxylic acid or anhydride thereof with polyols or an epoxide. Examples of suitable materials for preparing polyesters are described herein in relation to polyester polyols. Polyesters having hydroxyl functional groups can be prepared by the methods described above to make polyester polyols. The polyurethanes can also be used in the formulation of the functional component in the coating composition. The polyurethanes can be formed by reacting a polyisocyanate with a polyester having hydroxyl functionality and containing pendant hydroxyl groups. Examples of suitable polyisocyanates are aromatic and aliphatic polyisocyanates, with aliphatics being preferred because of their better color and durability properties. Examples of suitable aromatic diisocyanates are diphenylmethane-4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate and toluene diisocyanate. Examples of suitable aliphatic diisocyanates are straight chain aliphatic diisocyanates such as 1-tetramethylene diisocyanate and 1,6-hexamethylene diisocyanate. In addition, cycloaliphatic diisocyanates can be used and can be selected to impart hardness to the product. Examples include 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, alpha diisocyanate, alpha-xylylene and 4,4-methylene-bis- (cyclohexyl isocyanate). Other polyisocyanates useful for preparing the polyurethanes are included in the methods described above for making urethane polyols. The polyester or polyurethane materials used to prepare the functional component typically have an average number of molecular weights of about 300 to 3., 000, preferably from about 300 to 1,500, determined by gel permeation chromatography using a polystyrene standard, and an equivalent weight from about 140 to 2,500 based on the equivalents of the pendant, hydroxyl-functional groups. The equivalent weight is a value calculated on the basis of the relative amounts of the various ingredients used to make the polyester or polyurethane and is based on the solids of the material. The aminoplast resin of the coating composition of the present invention is in the composition in amounts of at least 1% by weight, preferably at least 2% by weight, and more preferably at least 5% by weight . Typically, the aminoplast resin is present in amounts of not more than 30% by weight, preferably not more than 20% by weight, and much more preferably, not more than 15% by weight in the coating composition. The amount of aminoplast resin in the coating composition can vary between any combination of these values, inclusive of the aforementioned values. Aminoplast resins are condensation products of amines or amides with aldehydes. Examples of suitable amines or amides are melamine, benzoguanamine, glycoluril, urea and similar compounds. Preferably, the aminoplast resin has at least two reactive groups, ie, groups that are reactive with the hydroxyl groups. In general, the aldehyde used is formaldehyde, although products of other aldehydes such as acetaldehyde, crotonaldehyde, benzaldehyde and furfural can be prepared. The condensation products contain methylol groups or similar alkylol groups depending on the particular aldehyde used. These alkylol groups can be heterified by reaction with an alcohol. The various alcohols used include monohydric alcohols containing 1 to 6 carbon atoms such as methanol, ethanol, isopropanol, n-butanol, pentanol and hexanol. Preferably, alcohols containing 1 to 4 carbon atoms are used. Aminoplast resins are commercially available from American Cyanamid Co. under the trademark CYMEL and from Monsanto Chemical Co. under the trademark RESIMENE. The preferred aminoplast resin for use in the coating composition of the present invention is a melamine-formaldehyde alkylated condensate found in products such as CYMEL ^ 345, 350 or 370 resins. However, condensation products can also be used of other amines and amides, for example, triazine aldehyde, diazines, triazoles, guanidines, guanimines, and alkyl and aryl substituted derivatives of such compounds, including alkyl and aryl substituted melamines. Some examples of such compounds are N, N'-dimethylurea, benzourea, dicyandiamide, formaguanamine, acetoguanamine, ammelin, 2-chloro-4,6-diamino-1, 3, 5-triazine, 6-methyl-2,4-diamino. -1, 3,5-triazine, 3,5-diaminotriazole, triaminopyrimidine, 2-mercapto-4,6-diamino-pyrimidine, 3,4,6-tris (ethylamino) -1,3, 5-triazine, tris ( alkoxycarbonylamino) triazine and the like. Typically, the amount of the component containing a functional group and the aminoplast component in the coating compositions of the invention are selected to provide an equivalents ratio of functional groups, hydroxyl, with respect to the equivalents of reactive aminoplast groups, ie, methylol or methylol ether groups, in the range of 0.5 to 2: 1. This ratio is based on the calculated equivalent weights and is sufficient to result in a crosslinked coating. The functional component and the aminoplast component in combination may be present in the coating composition in amounts of from 20 to 99.9, preferably from 60 to 95%, and most preferably from 70 to 90% by weight based on the weight of the total resin solids. The coating composition of the invention may include a catalytic agent to accelerate the curing reaction between the functional groups and the functional group containing the component and the reactive groups of the aminoplast component. Examples of suitable catalysts are acidic materials and include phosphoric acid or substituted phosphoric acid such as alkyl acid phosphate and phenyl acid phosphatesulfonic acids or substituted sulphonic acids such as paratoluensulonic acid, dodecylbenzinsulfonic acid and dinonylnaphthalenesulphonic acid. The amount of optional catalyst is a catalytic amount, that is, an amount necessary to catalyze the polymerization of the monomers. The catalyst may be present in an amount of 0.5 to 5.0% by weight, preferably 1 to 2% by weight, based on the total weight of the resin solids. After adding a catalytic amount of the catalyst, any manner of curing the polymerizable composition of the present invention that is appropriate for the specific composition and the substrate can be used. The solvents that may be present in the coating composition of the present invention are those that are necessary to dissolve the solid components. The minimum amount of solvent present in the coating composition is a solvating amount, that is, an amount which is sufficient to solubilize the solid components in the coating composition. For example, the amount of solvent present may vary from 10 to 80% by weight based on the total weight of the coating composition. Suitable solvents include, but are not limited to the following: benzene, toluene, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethanol, tetrahydrofurfuryl alcohol, propyl alcohol, propylene carbonate, N-methylpyrrolidinone, N-vinylpyrrolidinone, N-acetylpyrrolidinone, N-hydroxymethylpyrrolidinone , N-butylpyrrolidinone, N-ethylpyrrolidinone, N- (N-octyl) pyrrolidinone, N- (N-dodecyl) pyrrolidinone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methylcyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, methanol, amyl propionate, methyl propionate, propylene glycol methyl ether, diethylene glycol monobutyl ether, dimethyl sulfoxide, dimethylformamide, ethylene glycol, mono- and dialkyl ethers of ethylene glycol and their derivatives which are sold as industrial solvents CELLOSOLVE by Union Carbide, and mixtures of such solvents. The photochromic aminoplast resin coating composition of the present invention may further comprise additional conventional ingredients which impart the desired characteristics to the composition, of which are those required for the process used to apply and cure the composition to the substrate or which improve the finished cured coating thereof. Such additional ingredients comprise rheology control agents, leveling agents, for example surfactants, plasticizers such as benzoate esters, initiators, curing inhibiting agents, free radical scavengers, polymer chain terminating agents and adhesion promoting agents, as trialkoxysilanes, which preferably have an alkoxy radical of 1 to 4 carbon atoms, including β-glycosidoxypropyltrimethoxysilane, α-aminopropyltrimethoxysilane, 4-epoxycyclohexylethyltrimethoxy-silane and aminoethyltrimethoxysilane. The photochromic compounds that can be used in the aminoplast resin coating composition or compositions of the present invention are organic photochromic compounds. Such compounds can be used individually or in combination with other complementary photochromic compounds. The photochromic compounds or substances containing the same used in the coating composition described herein have at least one absorption maximum activated within the range of between about 400 and 700 nanometers. Such substances can be incorporated, for example, dissolved or dispersed, into an aminoplast resin composition used to prepare the photochromic aminoplast resin coating and color when activated at an appropriate tone. More particularly, in one embodiment, the organic photochromic component comprises: (a) at least one organic photochromic compound having a lambda maximum visible from 400 nanometers to 525 nanometers; and (b) at least one organic photochromic compound having a maximum visible lambda greater than 525 nanometers at 700 nanometers.

Examples of suitable photochromic compounds for use in the aminoplast resin coating composition of the present invention include benzopyrans, naphthopyrans, for example naphtho [1,2-b] pyrans and naphtho [2,1-b] pyrans, phenanthropyrans, quinopyrans. , benzoxazines, naftoxazines, spiro (indolino) pyridobenzoxazines and naphthopyrans fused with indene, such as those described in U.S. Patent 5,645,767. Specific examples include the novel naphthopyrans of U.S. Patent 5,658,501 and the complementary organic photochromic substances described in this patent from column 11, line 57 to column 13, line 36. Other photochromic substances contemplated for use herein are photochromic metal-dithiozoates, for example, mercury dithiozoates which are described, for example, in U.S. Patent 3,361,706; fulgides and fulgimides, for example 3-furyl and 3-thienyl-fulphides and fulgimides, which are described in U.S. Patent 4,931,220 in column 20, line 5 to column 21, line 38, and mixtures of suitable photochromic substances mentioned before. The descriptions in relation to such photochromic compounds in the patents described above are incorporated herein, in toto, by reference. The photochromic coatings of the present invention may contain a photochromic compound or a mixture of photochromic compounds, as desired. Mixtures of photochromic compounds can be used to obtain certain activated colors, such as near neutral gray or brown. An additional discussion of neutral colors and ways of describing such colors is found in U.S. Patent 5,645,767, column 12, line 66 to column 13, line 19. The amount of the photochromic substances described herein to be used in the coating or polymerization of the present invention is an amount sufficient to produce a photochromic effect discernible to the naked eye upon activation. Generally, such an amount can be described as a photochromic amount. The relative amounts of the photochromic compounds mentioned above that will be used will vary depending in part on the relative intensities of the color of the activated species of such compounds, and the desired final color. Generally, the amount of photochromic substance incorporated in the coating composition can vary from 0.1 to 40% by weight based on the weight of the solids in the coating composition. Preferably, the concentration of photochromic substances ranges from 1.0 to 30% by weight, and more preferably from 3 to 20% by weight, and much more preferably from 5 to 15% by weight, for example from 7 to 14% in weigh. The photochromic compound or compounds described herein can be incorporated into the coating composition by dissolving or dispersing the photochromic substance within a component, for example the organic polyol of the coating composition. The photochromic substance can be added directly to the coating composition or can be dissolved in solvent before adding it to the component or the formulated coating composition. Alternatively, the photochromic compounds can be incorporated into the cured coating or polymerized by imbibition, permeation or other transfer methods, as is known to those skilled in the art. Compatible inks (chemically and of a similar color), ie dyes, can be added to the coating composition, applied to the coated or applied article to the substrate before the coating achieves a more aesthetic result, for medical reasons, or for reasons of appearance. The particular dye selected will vary depending on the need mentioned above and the result obtained. In one embodiment, the dye can be selected to complement the color resulting from the activated photochromic substances, for example to obtain a more neutral color or absorb a particular wavelength of the incident light. In another embodiment, the colorant may be selected to provide a desired shade to the substrate or coated article when the photochromic substance is in a non-activated state.

The adjuvant materials can also be incorporated into the coating composition with the photochromic substances, before, simultaneously with or subsequent to the application or incorporation of the photochromic substances into the cured coating or coating composition. For example, substances that absorb ultraviolet light with photochromic substances can be mixed before they are added to the coating composition of such absorbent substances which can be superimposed, for example, placed on top, as a layer between the photochromic coating and the incident light. In addition, stabilizers can be mixed with the photochromic substances before their addition to the coating composition to improve the fatigue resistance of the photochromic substances. Stabilizers are contemplated such as amine light stabilizers (HALS), antioxidants, for example polyphenolic antioxidants, asymmetric diaryloxalamide (oxanilide) compounds and singlet oxygen scavengers, for example nickel ion complex with an organic ligand or mixtures of stabilizers. They can be used alone or in combination. Such stabilizers are described in U.S. Patents 4,720,356, 5,391,327 and 5,770,115, patents which are incorporated herein by reference.

The coating compositions of the present invention can be applied to substrates of any type such as, for example, paper, glass, ceramic, wood, masonry, textiles, metals and polymeric organic materials. Preferably, the substrate is a polymeric organic material, particularly thermosetting and thermoplastic polymeric organic materials, for example polymers of the thermoplastic polycarbonate type and copolymers and homopolymers or copolymers of a polyol (allyl carbonate) used as organic optical materials. coating applied to a substrate is an amount necessary to incorporate a sufficient amount of the organic photochromic substance or substances to produce a coating that exhibits the required change in optical density (? OD) when the cured coating is exposed to UV radiation. The required change in optical density is that which, when tested at 29.4 ° C (85 ° F) produces an? OD of at least 0.15 after 30 seconds and at least 0.47 after 8 minutes. The bleached rate of the photochromic coating (on or the photochromic substances in the coating) should be no greater than 180 seconds using the photochromic test response described in part D of example 16 herein.

The applied coating may have a thickness of at least 5 microns, preferably at least 10 microns, more preferably at least 20 microns, eg, 25 microns. The applied coating will also usually have a thickness of not more than 200 microns, preferably not greater than 100 microns, and more preferably not greater than 50 microns, for example 40 microns. The thickness of the coating can vary between any combination of these values, inclusive of the mentioned values. It is typical to treat the surface of the substrate to be coated before applying the coating composition of the present invention for purposes of cleaning the surface and promoting adhesion. Effective treatment techniques for plastics, such as those prepared from bis (allyl carbonate) monomer of diethylene glycol CR-39MR or thermoplastic polycarbonate, for example a resin derived from bisphenol A and phosgene, include ultrasonic cleaning; washing with an aqueous mixture of organic solvent, for example a 50:50 mixture of isopropanol: water or ethanol: water; UV treatment; activated gas treatment, for example treatment with a low temperature plasma discharge or corona discharge, and chemical treatment such as hydroxylation, ie etching the surface with an aqueous solution of an alkaline material, for example sodium hydroxide or potassium hydroxide which may also contain a fluoro surfactant. See U.S. Patent 3,971,872, column 3, lines 13 to 25; U.S. Patent 4,904,525, column 6, lines 10 to 48; and U.S. Patent 5,104,692, column 13, lines 10 to 59, which describe surface treatments of polymeric organic materials. This treatment used for cleaning glass surfaces will depend on the type of dirt present on the surface of the glass. Such treatments are known to those skilled in the art. For example, washing the glass with an aqueous solution that may contain an easy rinse detergent with little foaming, followed by rinsing and drying with a lint-free flannel; and a treatment with ultrasonic bath in heated wash water (approximately 50 ° C), followed by rinsing and drying. Pre-washing with a cleaner based on alcohol or an organic solvent before washing may be needed to remove adhesive substances from labels or tapes. In some cases, it may be necessary to apply a size to the surface of the substrate prior to the application of the coating composition of the present invention. The size serves as a barrier coating to prevent the interaction of the coating ingredients with the substrate and vice versa, or as an adhesive layer for adhering the coating composition to the substrate. The sizing application may be by any of the methods used in coating technology such as, for example, spray coating, centrifugal coating, dispersion coating, curtain coating, dip coating, and roll coating. The use of protective coatings, some of which may have polymer forming silane organs, as sizing agents to improve the adhesion of subsequently applied coatings, has already been described. In particular, the use of coatings that can not be dyed is preferred. Examples of commercial coating products include coatings SILVUE 124 and HI-GARD, available from SDC Coatings, Inc., and PPG Industries, Inc., respectively. Furthermore, depending on the proposed use of the coated article, it may be necessary to apply one or more suitable protective coatings, i.e., an abrasion-resistant coating on the exposed surface of the coating composition to avoid scraping the effects of friction and abrasion. In some cases, the sizing and protective coatings are interchangeable, that is, the same coating can be used as the sizing and as the coating or protective coatings. Other coatings or surface treatments, for example a dyeable coating, an anti-reflective surface, etc., may also be applied to the cured coating of the present invention. The coating composition of the present invention can be applied using the same methods described herein to apply the size and protective coatings or other methods known in the art can be used. Preferably, the coating composition is applied by centrifugal coating, curtain coating, dip coating, and spray coating methods, or by methods used in overlays of preparation, such methods for producing overlays are described in the US Patent. No. 4,873,027, which patent is incorporated herein by reference, After application of the coating composition to the treated surface of the substrate, the coating is cured, based on the components selected for the coating composition of the present invention. , the coating can be cured at temperatures ranging from 22 ° C to 200 ° C. If heating is required to obtain a cured coating, temperatures of between 80 ° C and a temperature above which the substrate is damaged are typically used. due to heating, for example 80 ° C to 200 ° C. For example, certain organic polymeric materials can be heated up to 130 ° C for a period of 1 to 16 hours in order to cure the coating without causing damage to the substrate. Although a range of temperatures has been described for curing the coated substrate, it will be recognized by those skilled in the art that temperatures other than those described herein can be used. Additional methods for curing the photochromic aminoplast resin coating composition include irradiating the coating with infrared, ultraviolet, visible, microwave or electron radiation. This can be followed by a heating step. Preferably, the resulting cured coating satisfies commercially acceptable "cosmetic" standards for optical coatings. Examples of cosmetic coated lens defects include an appearance similar to orange detachment, dents, spots, inclusions, fractures and cracks in the coating. Most preferably, the coatings are prepared using the photochromic coating composition of the present invention and are substantially free of cosmetic defects. Examples of polymeric organic materials that can be substrates for the coating composition of the present invention are polymers, ie homopolymers and copolymers of the monomers and mixtures of the monomers described in U.S. Patent 5,658,501, from column 15, line 28 to column 16, line 17, which is incorporated herein by reference. Examples of such monomers and polymers include: polyol monomers (allyl carbonate), for example bis (allyl carbonate) of diethylene glycol, monomer which is sold under the trademark CR-39; carbonate monomer terminated in poly (meth) acryloyl; diethylene glycol dimethacrylate monomers; ethoxylated phenol methacrylate monomers; diisopropenylbenzene monomers; ethoxylated trimethylolpropane triacrylate monomers; ethylene glycol bismetacrylate monomers; poly (ethylene glycol) bis methacrylate monomers; urethane acrylate monomers; poly (bisphenol A dimethacrylate ethoxylate); poly (vinyl acetate); poly (vinyl alcohol); polyvinylchloride); poly (vinylidene chloride); polyurethanes, polythiourethanes, thermoplastic polycarbonates such as the carbonate bound resin derived from bisphenol A and phosgene, which is sold under the trademark LEXAN; polyesters such as the material sold under the MYLAR trademark; poly (ethylene terephthalate); polyvinyl butyral and poly (methyl methacrylate) such as the material sold under the trademark PLEXIGLÁS, and mixtures thereof. More particularly contemplated is the use of the combination of the photochromic aminoplast resin coating composition of the present invention with polymeric organic materials such as optically clear polymerisates, ie materials suitable for optical applications, such as optical elements, for example flat and ophthalmic lenses for vision correction, advantages, transparent polymer films, transparencies for automobiles, for example windscreens, transparencies for aircraft, plastic laminates, etcetera. Such optically clear polymers can have a refractive index that can vary from 1.48 to 2.00, for example, from 1495 to 1.75 or from 1.50 to 1.66. Specifically contemplated optical elements made of thermoplastic polycarbonates are contemplated. The application of the photochromic aminoplast resin coating composition of the present invention to a polymeric film in the form of an "application" can be carried out using the methods described in column 17, line 28 to column 18, line 57 of the United States Patent 5,198,267. More particularly contemplated, is the use of the combination of the photochromic aminoplast resin coating composition of the present invention with optical elements to produce photochromic optical articles. Such articles are prepared by sequentially applying to the optical element a size, the photochromic aminoplast resin composition of the present invention and one or more suitable protective coatings. The resulting cured coating preferably satisfies commercially acceptable "cosmetic" standards for optical coatings, and more preferably, is substantially free of cosmetic defects. In another embodiment of the invention, the photochromic coating composition can be used to form polymerized, for example optically clear solid shaped polymerized composites as defined herein with respect to polymeric organic materials. The polymerization of the coating composition can be carried out by adding a catalyst to the polymerizable composition and curing in a manner appropriate for the specific composition and the desired shape. The resulting polymer demonstrates the same Fischer microhardness and the photochromic performance properties of the cured coating, and is substantially free of cosmetic defects and may have a thickness of 0.5 millimeters or greater. In a contemplated embodiment, a two-part glass lens mold is filled with the photochromic desolvated coating composition, i.e., the polymerizable composition containing a minimum amount of solvent, which additionally may contain a catalytic amount of acid. phosphoric. The glass mold is sealed and placed in an oven. A thermal polymerization cycle is started, which can vary from 10 to 20 hours at a temperature of 45 to 110 ° C. Then the mold and the resulting lens are opened, that is, the polymerized, is removed. The polymer lens produced in this way is then annealed for a period and at a temperature sufficient to eliminate the residual stresses in the lens. The temperature is generally between 100 and 110 ° C and the annealing is carried out for 1 to 5 hours. If the photochromic material is not included in the polymerizable composition, it can be incorporated into the polymerized by imbibition, permeation or other transfer method known to those known in the art. In a further contemplated embodiment, a single semi-finished vision lens (SFSV) having an adherent layer of the photochromic crosslinkable composition of the present invention can be prepared by an overmolding process. Typically, a predetermined volume of the photochromic polymerizable composition is delivered in a volume defined by a spherical negative glass mold, which roughly matches the curve of the front surface of the outer diameter of an SFSV lens. The glass mold is placed with a circular polyvinyl chloride gasket that extends approximately 0.2 millimeters above the mold and has a lower diameter approximately 4 millimeters smaller than the outer diameter of the glass mold. After the monomer is supplied, the SFSV lens is carefully placed in the polymerizable composition - 4.8 - supplied which diffuses to fill the defined volume. A circular glass plate having an outer diameter equal to or greater than that of the lens is placed on the rear surface of the lens. A spring clip is placed so that one side of the clip is on the front surface of the negative mold and the other side of the clip is on the back surface of the glass plate. The resulting assembly is sealed by covering the circumference of the plate-lens-joint-mold using polyurethane tape. The assembly is preheated in an air oven, from 30 to 95 ° C for 60 minutes and subsequently the temperature increases from 95 ° C to 125 ° C and decreases to 82 ° C during a 3 hour interval. The assembly is separated by inserting a wedge under the joint between the lens and the mold. The lens now has an adherent layer of 180 to 200 microns if no photochromic material is included in the polymerizable composition, it can be incorporated into the adherent layer by imbibition, permeation or other transfer method known to those skilled in the art. The present invention is described more particularly in the following examples, which are considered only as illustrative, since numerous modifications and variations therein will be apparent to those skilled in the art. - 4Í > - Composition A The following materials are added in the order and manner described to a suitable reaction vessel equipped with an agitator, a fractional distillation column, a condenser, a receiver receiving distillation, a nitrogen inlet, an internal temperature probe connected to an external electronic controller and a heating blanket: Load-1 Material Weight (grams) Solvent SOVESSO 100 (1) 120 Xylene 120 Isobutanol 48 Load-2 Material Weight (wrong) Hydroxypropyl acrylate 448 Butyl acrylate 212.8 Butyl methacrylate 207.2 Styrene 224.0 Acrylic acid 22.4 Methyl methacrylate 5.6 Tertiary dodecyl mercaptan 11.2 Load-3 Material Weight (grams) Xylene 96 Solvent SOLVESSO 100 72 Initiator VAZO-d? ^ 56 Load-4 Material Weight (grams Solvent SOLVESSO 100 '12 Initiator VAZO-67M 4.5 Load-5 Material Weight (grams) Solvent SOLVESSO 100 12 Initiator VAZO- 67MR 4.5 (1) Exxon aromatic solvent available. (2) 2,2'-azobis- (2-methylbutyronitrile) available from E. I. duPont de Nemours and Company.

The charge-1 is added to the reaction vessel. The nitrogen is introduced into the vessel and with the agitator running and heat is applied to the reaction vessel to maintain the temperature at which the reflux of the solvent occurs. After reaching the reflux temperature, charges 2 and 3 are separately added to the reaction vessel in a continuous manner for a period of 2 hours. Subsequently, the charge 4 is added and the reaction mixture is maintained for an additional 1 hour at the reflux temperature. The filler-5 is then added and the reaction mixture is maintained for an additional 1.5 hours at the reflux temperature. The contents of the reaction vessel are then cooled and transferred to a suitable vessel. The resulting polymer solution has a total solids content calculated, based on the weight of the total solution, of about 70.7%. The polymer has an average weight of molecular weight, measured by gel permeation chromatography using polystyrene as a standard, of about 9,000, and a hydroxyl value of about 170, based on the polymer solids.

Composition B The following materials are added in the order described to an appropriate container.

Material Weight (grams) Photochromic 1 (3) 5,229 TSNUVIN * 144 UV Stabilizer (4> 1,268 BAYSILONE Paint Additive "PL (5) 0.315 pTSA (6) 0.252 NMP (11) 32.55 (3) A naphtho [1,2-b] pyran that shows a blue color when irradiated with ultraviolet light. (4) A hindered amine ultraviolet light stabilizer available from CIBA-GEIGY CORPORATION. (5) Phenylmethylpolysiloxane available from Bayer Corporation. (6) Para-toluenesulfonic acid. (7) N-methylpyrrolidone solvent of 99% purity.

After all the materials are added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Composition C The following materials are added in the order described to an appropriate container.

Material Weight (grams! Photochromic 1 5.90 Stabilizer TINUVIN ^ 144 UV 1.48 NMF '79.03 Resin CYMEL ^ 350 18.29 (8) Described as partially alkylated formaldehyde melamine resin available from CYTEC Industries, Inc.

After all the materials are added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Composition D The following materials are added in the order described, to an appropriate container.

Material Weight (grams) Photochromic 1 5.83 Stabilizer TINUVIN1 ^ 144 UV 1.46 NMP 29.48 Resin CYMEL * ® 345 < 9) 19.76 (9) Described as a methylated formaldehyde melamine resin, with high imino percentage, available from CYTEC Industries, Inc.

After all the materials have been added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Composition E The following materials are added in the order described, to an appropriate container.

Material Weight (grams) Photochromic 1 7.02 Stabilizer TINUVIN ^ 144 UV 1.75 NMP 39.68 Resin CYMEL "11 345 (9> 19.63 (10) Described as a highly methylated monomeric formaldehyde melamine resin, available from CYTEC Industries, Inc.

After all the materials have been added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Example 1 The following materials are added in the order described to an appropriate container.

Material Weight (grams) Composition A 4.86 CYMEL * ® 350 resin 1.51 Composition B 3.77 After all materials are added to the container, the contents are mixed at 2000 revolutions per minute (rpm) for approximately 2 minutes, if necessary, to obtain a clear solution.

Example 2 The procedure of Example 1 is followed, except that 4.62 grams of composition A are used and 0.17 grams of polypropylene glycol having an average molecular weight number of 2,200 are used. The same amounts of the other materials are used in the composition of Example 1 .

Example 3 The procedure of Example 2 is followed, except that 4.37 grams of composition A are used and 0.34 grams of polypropylene glycol are used.

Example 4 The procedure for example 2 is followed, except that 4.13 grams of composition A and 0.51 grams of polypropylene glycol are used.

Example 5 Stage 1 The following materials are added in the order described to a suitable container equipped with an agitator.

Material Weight (grams) Photochromic 1 5.83 Stabilizer TINUVINMR 144 UV 1.46 Paint additive BAYSILONE "PL 0.55 Phosphoric acid 0.53 NMP 29.48 CYMEL resin ^ 345 19.70 After all the materials are added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Stage 2 The following materials are added in the order described to a suitable container equipped with an agitator.

Material Weight (grams) Composition A 3.65 product of stage 1 4.57 pTHF (11) 0.28 (11) Poly (oxytetramethylene) diol having an average number of molecular weight of 1000 which is available from Great Lakes Chemical Corporation After all the materials are added to the container, the contents are mixed at 2000 rpm for approximately 2 minutes, if necessary, to obtain a clear solution.

Example 6 The procedure of Example 5 is followed, except that in step 2, 3.24 grams of composition A and 0.57 grams of PTHF are used. The same amounts of the other materials are used in the composition of Example 5.

Example 7 The procedure of example 5 is followed, except that in stage 2 2.84 grams of composition A and 0.85 grams of pTHF are used.

Example 8 The procedure of Example 5 is followed, except that in step 2, 2.43 grams of composition A are used and 1. 14 grams of pTHF Example 9 Stage 1 The following materials are added in the order described to a suitable container equipped with an agitator.

Material Weight (grams) Photochromic 1 5.90 Stabilizer TINUVTN'1® 144 UV 1.48 Paint additive BAYSILONE "PL 0.05 Phosphoric acid 0.53 NMP 31.698 CYMEL resin" 1 * 345 18.2 After all the materials are added to the container, the contents are heated for approximately 15 minutes at 60 ° C.

Stage 2 The following materials are added in the order described to an appropriate container.

Material Weight (grams) Composition A 3.70 pTHF 0.29 product of stage 1 4.45 After all the materials are added to the container, the contents are mixed at 5000 rpm for about 2 minutes, if necessary, to obtain a clear solution.

Example 10 The procedure of example 95 is followed, except that in step 2, 3.294 grams of composition A and 0.58 grams of PTHF are used.

Example 11 The procedure of example 9 is followed, except that in stage 2 2.88 grams of composition A and 0.86 grams of pTHF are used.

Example 12 The following materials are added in the order described to an appropriate container.

Material Weight (grams) Composition C 4.41 Composition A 3.70 pTHF 0.29 After all the materials are added to the container, the contents are mixed at 500 rpm for about 2 minutes, if necessary, to obtain a clear solution.

Example 13 The procedure of Example 12 is followed, except that 3.29 grams of composition A and 0.58 grams of pTHF are used.

Example 14 The procedure of example 12 is followed, except that 4.35 grams of composition D are used instead of composition C, and 3.65 grams of composition A and 0.28 grams of pTHF are used.

Example 15 The procedure of Example 12 is followed, except that 5.24 grams of composition E are used in place of composition C and 4.86 grams of composition A are used. PTHF is not used.

Comparative Example 1 The procedure for example 2 is followed, except that 3.89 grams of composition A and 0.68 grams of polypropylene glycol are used.

Comparative Example 2 The procedure for example 5 is followed, except that in step 2, 4.05 grams of composition A are used and pTHF is not added.

Comparative Example 3 The procedure for example 5 is followed, except that in step 2 2.03 grams of composition A and 1.42 grams of pTHF are used.

Comparative Example 4 The procedure for example 9 is followed, except that in step 2, 4.11 grams of composition A are used and pTHF is not added.

Comparative Example 5 - 4 - The procedure for example 9 is followed, except that in step 2, 2.47 grams of composition A and 1.15 grams of pTHF are used.

Comparative Examples 6-10 The procedures described in Japanese Patent Application Number 61-268788 are followed for the preparation of the application examples (AE) 1, 2, 3, 6 and 7, to produce the comparative examples 6, 7, 8, 9 and 10 with the exception that spironaphthoxazine is substituted with the amount of Photochromic 1 used in the examples herein and ethyl cellosolve 400 is replaced with N-methylpyrrolidone (NMP). The AE 4 and 5 do not duplicate since the same prepolymer and the polyol weights were used in AE 2 of JP 61-268788. The differences between AE 2 and AE 4 and 5 are that AE 4 contains 4 times the amount of photochromic in AE2, and AE5 uses 2 parts of IN hydrochloric acid as the curing accelerator instead of 0.5 parts of NH4SCN. The specific procedures used to prepare the comparative examples 6-10 are included in the following.

Part A The following materials are added in the order and manner described • to a suitable reaction vessel equipped with a magnetic stirring apparatus, a fractional distillation column, a condenser, a distillation receiver, a nitrogen inlet, a thermometer and a heating mantilla: Material Weight (grams) RESIN CYME ™ 350 293.0 1, -butanediol 195.0 0.1 M phosphoric acid The charge 1 is added to the reaction vessel; a layer of N2 is applied and the magnetic stirrer is turned on. Then heat is applied to the reaction vessel; at 130 ° C the N2 layer is converted to a N2 discharge and the reaction mixture is maintained at this temperature for about 4 hours to produce 50 grams of distillate.

Part B To a reaction flask are added 100 grams of butyl acrylate, 25 grams of 2-hydroxyethyl methacrylate and 1.3 grams of azoisobutyl nitrile (AIBN) to a reaction flask containing 600 grams of ethyl alcohol. The reaction mixture is heated to reflux at approximately 70 ° C and maintained at this temperature for 8 hours. The resulting polymer product has a total solids content calculated, based on the total weight of the solution, of 17.38%. The polymer has a hydroxyl value of about 86.3, based on the polymer solids. The polymer is concentrated at 64.5% solids, based on the weight of the total solution, by rotary evaporation to reduce the level of ethyl alcohol in which the Photocromic No. 1 material is minimally soluble.

Part C Add 10 grams of methyl methacrylate, 46.5 grams of 2-hydroxyethyl methacrylate and 1.3 grams of azoisobutyl nitrile (AIBN) to a reaction flask containing 600 grams of ethyl alcohol. The reaction mixture is heated to reflux, about 70 ° C and maintained at this temperature for 8 hours. The resulting polymer product has a total solids content calculated, based on the total weight of the solution, of 8.78%. The polymer has a hydroxyl value of about 397.8 based on the polymer solids. The polymer is concentrated at 37.8% solids, based on the weight of the total solution, by rotary evaporation to reduce the level of ethyl alcohol in which the Photocromic No. 1 material is minimally soluble.

Part D The materials listed below, in grams (g) is added to a suitable container, mixed at 500 rpm for approximately 2 minutes, if necessary, to obtain a clear solution.

Product Product Product Number of part of part of part NH4SCN PC No. Sample A (g) B (g) C (g) (g) 1 (g) NMP (g) CE 6 4.0 8.53 0.05 1.03 4.54 CE 7 6.0 6.2 0.05 1.03 6.5 CE 8 8.5 2.3 0.05 1.03 6.9 CE 9 6.0 10.6 0.05 1.03 2.1 CE 10 8.5 3.97 0.05 1.03 6.2 Comparative Example 11 The procedure of Example 12 is followed, except that 4.11 grams of composition A and 0 grams of pTHF are used.

Comparative Example 12 The procedure of Example 12 is followed, except that 2.88 grams of composition A and 0.86 grams of pTHF are used.

Comparative Example 1.3 The procedure of Example 14 is followed, except that 4.05 grams of composition A are used in 0. grams of pTHF.

Comparative Example 14 • The procedure of Example 14 is followed, except that 3.24 grams of composition A and 0.57 grams of pTHF are used. - §9 - Comparative Example 15 The procedure of Example 15 is followed, except that 4.37 grams of composition A and 0.34 grams of pTHF are used.

Example 16 Part A The solutions prepared in Examples 1-15 and Comparative Examples 1-15 are applied by a rotary coating method to preforms of lenses made of monomer CR-39m. Prior to coating application, each lens preform is washed with detergent, rinsed with water, immersed for 3 minutes in an aqueous solution of potassium hydroxide having a normality of about 2.4 which is maintained at about 50 ° C. and then rinsed twice with deionized water. The subsequent immersion and rinsing steps are carried out in a Bramson Ultrasonic Model 5200 Sonnicater. The solutions are supplied on each of the lenses which rotate at 2000 rpm. The lenses are coated with solutions of the examples and comparative examples and cured for 40 minutes in a convection oven maintained at 140 ° C. - 1o - A duplicate lens for each of the comparative examples 6-10 is also cured for 3 hours at 140 ° C as described in JP 61-268788. The results for the tests performed in the subsequent parts on the cured lenses for 3 hours were comparable with the results obtained in the lenses cured for 40 minutes and are not included in the tables.

Part B The photochromic coated test examples that are prepared in part A are subjected to microhardness test (Fh) using a Fischerscope HCV equipment, model H-100 available from Fischer Technology, Inc. The microhardness, measured in Newtons (N) per mm 2 of the coated test samples is determined by taking 3 measurements at a depth of 2 microns in the central area of the test sample prepared for each example and comparative example under the conditions of a load of 100 milliNewton, stages of 30 loads and pauses of 0.5 seconds between the loading stages. Before the test, each lens is stored in a closed chamber that has a humidity of no more than 50%, for example 30% for at least 12 hours. Table 1 includes the results of the test.

All lenses coated with the solutions of Comparative Examples 6-9 demonstrate cosmetic effects. The lenses coated with comparative examples 6, 7 and 8 have a hazy appearance, indicating phase separation in the coating formulation. The lenses of comparative example 9 have a precipitate which is also indicative of the instability of the product.

Part C Place the photochromic coated test lenses from part B on a Siemens PE-1000 AC Plasma unit. The lenses are treated with oxygen plasma under the following conditions: the energy is adjusted to 100 Watts; the gas pressure is 38 pascals; a gas flow rate of 100 ml / minute is used; The processing time is 60 seconds. Plasma-treated lenses are coated with a HiGard coating solution "11 1030 via a rotating coating method." Approximately 4 ml of HiGard® 1030 coating solution is supplied in each of the lenses which rotate at 1100 revolutions per minute ( rpm) for 13 seconds, then the lenses are heated in an oven at 60 ° C for 20 minutes and then in an oven at 120 ° C for 3 hours. - ^ 2 - Part D The photochromic coated test examples that are prepared in part C are placed for photochromic response in an optical rack in a 85 ° F photochromic performance test described in the following. Prior to testing on the optical rack, the photochromic test samples are exposed to ultraviolet light at 365 nanometers for approximately 20 minutes to activate the photochromic compounds and then placed in an oven at 75 ° C for approximately 20 minutes to bleach (inactivate ) the photochromic compounds. The coated test specimens are then cooled to room temperature, exposed to normal fluorescent illumination for at least 2 hours and then kept covered for at least 2 hours before performing the test on an optical rack. The shelf is placed with the 300 watt xenon arc lamp, a remote control switch, a Schott 3 mm bandpass filter KG-2, which removes short wavelength radiation, neutral density filters, a quartz cell sample holder to maintain the temperature of the sample in which the test sample to be tested is inserted. Adjust the energy output of the optical shelf, ie the dosage of light at which the test sample should be exposed to 0.67 milliwatts per square centimeter (mW / cm2) using a GRASEBY Optronics Model S-371 portable photometer (number series 21536) with a UV-A detector (serial number 22411). The UV-A detector is placed on a sample holder and the light output is measured. Adjustments are made to the energy output by increasing or decreasing the watage of the lamp or by adding or removing neutral density filters in the light path. A beam of collimated surveillance light is passed from a tungsten lamp through the sample at 30 ° normal to the surface of the lenses. After passing through the lenses, the light from the tungsten lamp is directed through a 570 nanometer (nm) filter attached to a detector. The 570 nm filter allows the passage of characteristic wavelengths of the photochromic compound used in the examples. The output signals of the detector are processed by a radiometer. The control of the test conditions and data acquisition is handled by the Labtech Notebook Pro software and the recommended I / O board. The change in optical density (? OD) from the bleached state to the darkened state is determined by examining the initial transmittance, opening the shutter of the xenon lamp to provide ultraviolet radiation to change the test sample from the bleached state to an activated state. (ie darkened) at selected time intervals, measure the transmittance in the activated state and calculate the change in optical density according to the formula:? OD = log (% Tb /% Ta), where% Tb is the percentage of transmittance in the blanched state,% Ta is the percentage of transmittance in the activated state and the logarithm is in base 10. It is measured? OD using a 570 nanometer filter after the first thirty ( 30) seconds of UV exposure and after every eight (8) minutes with an optical shelf maintained at a temperature of 29.4 ° C (85 ° F). The whitening rate (T 1/2) is the time interval in seconds for the OD of the activated form of the photochromic compound in the coated test samples to reach half of the highest OD at 29.4 ° C, (85 ° F) after removal of the activating light source. The results for the photochromic coated test samples for each example and the comparative example are included in table 2.

Table 1 Fischer microhardness Example No, Newtons / mm2 1 138 2 114 3 78 4 62 5 174 6 119 - T'S 7 77 8 57 9 159 89 11 47 12 120 13 48 14 102 109 IEC 36 CE2 206 CE3 27 CE4 192 CE5 27 CE6 CE7 71 CE8 130 CE9 ** CE10 187 CEU 174 CE12 20 CE13 197 CE14 35 CE15 18 * Fischer microhardness not determined because the coating is too sticky ** Fischer microhardness not determined due to the. coating contains precipitates that generate an irregular surface.

Table 2 ? OD @ 29 .4C 'C? OD © 29 .4' 'C T 1/2 (85 ° F) (85 ° F) seconds E nish No. After iie 30 After 8 seconds minutes i 0.17 0.74 137 2 0.30 0.75 75 3 0.38 0.74 57 4 0.39 0.73 50 5 0.18 0.47 104 6 0.31 0.57 46 7 0.39 0.58 32 8 0.41 0.58 28 9 0.23 0.55 75 10 0.37 0.60 39 11 0.43 0.61 27 12 0.34 0.68 55 13 0.44 0.65 32 14 0.22 0.58 94 15 0.36 1.15 161 CEI 0.46 0.74 40 CE2 0.07 0.32 370 CE3 0.46 0.60 22 CE4"0.09 0.39 306 CE5 0.47 0.61 23 CE6 0.44 0.56 19 CE7 0.29 0.46 35 CE8 0.14 0.33 138 CE9 0.05 0.26> 500 CE10 0.04 0.19> 500 CEU 0.14 0.63 193 CE12 0.48 0.86 45 CE13 0.10 0.45 415 CE14 0.35 0.63 43 CEI5 0.70 0.99 62 The results of table 1 and 2 show that the lenses coated with the solutions of examples 1 to 15 have the following properties: the microhardness results which are within the desired range of 45 to 180 Newtons / mm2, a? OD of at least 0.15 after 30 seconds and at least 0.47 after 8 minutes; and a fade rate not greater than 180 seconds, all are tested at 29.4 ° C (85 ° F). All of the lenses coated with the solutions of the comparative examples have a result by at least one of the above-mentioned properties that is outside the desired range or demonstrated cosmetic defects, eg, the comparative examples 6-9 as presented in FIG. part B of this example. Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details be construed as limitations on the scope of the invention, except insofar as they are included in the appended claims.

Claims (26)

1. An article comprising, in combination, a substrate and a cured aminoplast resin coating containing one or more photochromic compounds on at least one surface of the substrate, the photochromic aminoplast resin coating is prepared from a coating composition comprising: a) a reaction product of (i) one or more components having 2 hydroxyl groups; and (ii) aminoplast resin having at least two groups that are reactive with the hydroxyl groups; the reaction product is prepared in the presence of: (b) one or more photochromic compounds, components (a) (i), (a) (ii) and (b) are used in such proportions that they produce a cured coating that shows a Fischer microhardness from at least 45 up to a maximum of 180 newtons per mm2, the cross-coating has a photochromic amount of one or more photocromic compounds showing properties characterized by an "OD of at least 0.15 after 30 seconds and so less 0.55 after 8 minutes, and a bleaching speed not greater than 180 seconds - all measured in the photochromic performance test at 29.4 ° C (85 ° F).

2. The article accng to claim 1, characterized in that the cured coating shows a Fischer microhardness of at least 55 up to a maximum of 160 Newtons per mm2, a "OD of at least 0.16 after 30 seconds and a blanking rate not greater than 140 seconds.

3. The article accng to claim 1, characterized in that the cured coating shows a Fischer microhardness from at least 60 up to a maximum of 150 Newtons per mm2, a? OD of at least 0.17 after 30 seconds and a blanching rate. no more than 100 seconds

4. The article accng to claim 1, characterized in that the photochromic aminoplast resin coating further comprises a catalytic amount of catalyst to accelerate the curing reaction between the hydroxyl groups of (a) (i) and the aminoplast reactive groups of (a) (ii).

5. The article in accnce with the claim 4, characterized in that the catalyst is selected from phosphoric acid, substituted phosphoric acid, sulfonic acid, substituted sulfonic acid or mixtures of such acids.

6. The article accng to claim 1, characterized in that the equivalent ratio of the functional hydroxyl groups (a) (i) to the aminoplast groups (a) (ii) varies from 0.5 to 2.0: 1.

7. The article accng to claim 1, characterized by the hydroxyl component (a) (i) has an average molecular weight number of 62 to 50,000.

8. The article in accnce with the claim 7, characterized in that the hydroxyl component is selected from polyacrylic polyols, polyester polyols, polyether polyols or mixtures thereof.

9. The article accng to claim 1, characterized in that the hydroxyl component is selected from polyacrylic polyols, polyether polyols or mixtures thereof.

10. The article in accnce with the claim 8, characterized in that the polyacrylic polyol is a copolymer of ethylenically unsaturated monomers having at least two hydroxyl groups and at least one polymerizable ethylenically unsaturated monomer which is free of hydroxyl groups.

11. The article accng to claim 1, characterized in that the aminoplast resin is a condensate of melamine with formaldehyde and optionally an alcohol containing from 1 to 6 carbon atoms.

12. The article accng to claim 11, characterized in that the aminoplast component is a condensation product of melamine with formaldehyde and an alcohol containing 1 to 4 carbon atoms.

13. The article accng to claim 1, characterized in that the reactive groups of the aminoplast resin are selected from methylol, methylol ether groups or combinations thereof.

1 . The article according to claim 1, characterized in that the photochromic component (s) comprise: (a) at least one photochromic compound having a lambda maximum visible from 400 nanometers to 525 nanometers; And (b) at least one photochromic compound having a lambda maximum visible from greater than 525 nanometers to 700 nanometers.

15. The article according to claim 14, characterized in that the photochromic compound or compounds are benzopyrans, naphthopyrans, phenanthropyrans, quinopyrans, naphthopyrans fused with indene, benzoxazines, naphthoxazines, spiro (indolino) pyridobenzoxazines, metal dithytonates, fulgida, fulgimides or mixtures of the same.

16. The article according to claim 1, characterized in that the photochromic aminoplast resin coating has a thickness of 5 to 200 micrometers.

17. The article according to claim 16, characterized in that the photochromic aminoplast resin coating has a thickness of 10 to 40 micrometers.

18. The article according to claim 1, characterized in that the substrate is paper, glass, ceramic material, wood, masonry, textile material, metal or polymeric organic materials.

19. The article according to claim 18, characterized in that the polymeric organic material is a solid transparent polymer that is selected from the group consisting of poly (methyl methacrylate), poly (ethylene glycol bismethacrylate), poly (bisphenol A dimethacrylate ethoxylate) , poly (thermoplastic carbonate), poly (vinyl acetate), polyvinyl butyral, polyurethane, polythiourethanes and polymers of members of the group consisting of diethylene glycol bis (allyl carbonate) monomers, diethylene glycol dimethacrylate monomers, ethoxylated phenol methacrylate monomers , diisopropenylbenzene monomers, trimetinol propane ethoxylated triacrylate monomers and mixtures thereof.

20. The article according to claim 19, characterized in that the substrate is an optical element.

21. The article according to claim 20, characterized in that the optical element is a lens.

22. The article in accordance with the claim 21, characterized in that the refractive index of the lens is 1.48 to 2.00.

23. A photochromic article, characterized in that it comprises a polymerizate of a polymerizable composition comprising: (a) a reaction product of: (i) one or more components having at least two hydroxyl groups; (ii) an aminoplast resin having at least two groups that are reactive with the hydroxyl groups; the reaction product is prepared in the presence of: (b) one or more photochromic compounds, the components (a) (i), (a) (ii) and (b) are used in such proportions as to produce a polymerisate showing a microhardness Fischer from at least 45 to not more than 180 Newtons per mm2, the cured coating has a photochromic amount of one or more photochromic compounds showing properties characterized by an "OD of at least 0.15 after 30 seconds and at least 0.55. after 8 minutes, and a bleaching speed of no more than 180 seconds - all measured in the photochromic performance test at 29.4 ° C (85 ° F).

24. The photochromic article according to claim 23, characterized in that the polymerizable composition further comprises a catalytic amount of catalyst.

25. The photochromic article according to claim 23, characterized in that the article is a lens.

26. The photochromic article according to claim 25, characterized in that the lens has a thickness of at least 0.5 mm.