MXPA06009937A - Photochromic optical article - Google Patents

Abstract

Describes a photochromic plastic article, e.g., an opthalmic photochromic article, such as a lens, in which the article includes (1) a rigid substrate, e.g., polymeric substrate, such as a thermoset or thermoplastic substrate, (2) a photochromic polymeric coating appended to a least one surface of the substrate, the photochromic polymeric coating containing a photochromic amount of at least one photochromic material, e.g., spirooxazine, naphthopyran and/or fulgide, and (3) a dentitric polyester acrylate film coherently appended to the photochromic coating. Describes also the aforedescribed photochromic article having an abrasion-resistant coating affixed to the dentitric polyester acrylate film, e.g., an abrasion-resistant coating comprising an organo silane;and a photochromic article having an antireflective coating affixed to the abrasion-resistant coating.

Description

OPTICAL ARTICLE PHOTOCROMICO DESCRIPTION OF THE INVENTION The present invention relates to photochromic articles comprising a rigid substrate to which a photochromic polymeric coating is applied on which a transparent polymer comprising a dendritic polyester acrylate is superimposed. In particular, the present invention relates to rigid transparent substrates, for example, glass and organic plastic substrates used for optical applications. More particularly, the present invention relates to photochromic articles used for ophthalmic applications, for example, contact lenses. Still more particularly, the present invention relates to photochromic articles comprising a transparent polymeric substrate having a transparent photochromic organic polymeric coating added to at least a portion of at least one surface of the substrate, and a transparent layer comprising a polyester acrylate. Dendritic superimposed on said photochromic coating. In a particular embodiment, the present invention relates to photochromic articles such as an ophthalmic plastic lens, on at least a portion of at least one surface from which it has been sequentially added, a first layer of a transparent, transparent, optically transparent photochromic coating. , and a second layer of a transparent dendritic polyester acrylate. In a further embodiment of the present invention, photochromic articles having a third layer comprising at least one abrasion resistant coating overlying the second layer are contemplated. In a further embodiment, a fourth layer, for example an antireflective coating is superimposed on the abrasion resistant coating. Additional layers may be applied to or below the fourth layer to provide additional functional properties to the photochromic article, for example antistatic and / or anti-wetting coatings. Transparent ophthalmic articles that provide good image quality, while reducing the transmission of incident light to the eye, are necessary for various applications such as sunglasses, ophthalmic lenses for vision correction, flat lenses and color lenses, for example, prescription and non-prescription lenses, sports masks, facial protections, diving goggles, safety glasses, camera lenses, windows, car windshields and transparent elements for aircraft and cars, for example T roofs, side windows and rear windows . Responding to this need, considerable attention has been given to photochromic plastic articles used for optical applications. In particular, photochromic ophthalmic plastic lenses have been of interest due to the weight advantage they offer, vis-à-vis, with respect to glass lenses. In addition, the embodiments of the present invention may be used in association with films and sheets of plastic, optical devices, for example optical switches, visualization devices and memory storage devices, such as those described in U.S. Patent No. 6,589. .452 and security elements, such as optical reading data media, for example those described in U.S. Patent Application No. 2002/0142248, security elements in the form of strands or strips as described in the Patent of US No. 6,474,695, and security elements in the form of verification marks that can be placed on security documents and articles of manufacture. Photochromism is a phenomenon that involves a reversible change in the color of an organic or inorganic material, for example a chromene or a silver halide salt, or an article comprising said material, after exposure to ultraviolet radiation. Radiation sources containing ultraviolet rays include, for example, sunlight and light from a mercury lamp. When the photochromic material is exposed to ultraviolet radiation, presents a color change, and when the ultraviolet radiation is discontinuous, the photochromic material returns to its original color or to its colorless state. Ophthalmic articles having a photochromic material or materials applied to or incorporated within the article show this reversible color change and a consequential reversible change in light transmission. The mechanism believed to be responsible for the reversible change of color, ie the change in the absorption spectrum in the electromagnetic spectrum of visible light (400-700 nm), which is characteristic of different types of organic photochromic compounds, has been described. See, for example, John C. Crano, "Chromogenic Materials (Photochromic)", Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, 1993, p. 321-332. The mechanism responsible for reversible color change for organic photochromic compounds, such as indolino spiropyrans and indolino spirooxazines, is believed to involve an electrocyclic mechanism. When exposed to ultraviolet radiation activation, these photochromic organic compounds are transformed from a colorless closed ring form to a colored open ring shape. In contrast, the electrocyclic mechanism responsible for the reversible color change of photochromic fulled compounds is believed to involve a transformation from a colorless open ring form to a colored closed ring shape. The photochromic plastic articles have been prepared by incorporating the photochromic material into the plastic substrate by means of surface embedding techniques. In said method, the photochromic dyes are incorporated in the surface region, of a plastic article, such as a lens, by first applying one or more dyes / photochromic compounds to the surface of the plastic article, either as pure dye / photochromic compound or dissolved in a polymeric vehicle or other organic solvent, and then applying heat to the coated surface to cause the colorant / photochromic compound or compounds to diffuse into the surface region of the plastic article (a process commonly referred to as "embedding"). The plastic substrates of said photochromic plastic articles are presented as having a sufficient free volume within the polymer matrix to allow the photochromic compounds, such as the spirooxazines, spiropyrans and fulgida mentioned above, to be transformed from a colorless to a colored form , and then return to its original colorless form. However, there are certain polymer matrices that are presented as not having sufficient volume to allow the electrocylic mechanism described above to occur to a sufficient extent to allow its use as a substrate for embedded (or internally incorporated) photochromic materials for commercially acceptable photochromic applications. Such substrates include, for example, thermosetting polymer matrices, such as those prepared from polyol (allyl carbonate) monomers, to highlight allyl diglycol carbonate monomers, for example diethylene glycol bis (allyl carbonate), and copolymers thereof, thermoplastic polycarbonates based on bisphenol A usually known, and highly crosslinked optical polymers. To allow the use of thermoset polymers, thermoplastic polycarbonates and highly crosslinked optical polymeric materials as plastic substrates for photochromic articles, it has been proposed to apply organic photochromic coatings to the surface of said plastic substrates. It has also been proposed to apply an abrasion resistant coating on the surface exposed to the photochromic coating to protect the surface of the photochromic coating from scratches and other similar cosmetic defects resulting from physical handling, cleaning and other exposure of the photochromic coating to the environment. In certain circumstances involving ophthalmic plastic lenses that have a photochromic polymer coating and coated with an abrasion resistant coating, it has been observed that when said lenses are scratched deeply, cleaning said scratched lenses with commercially available cleaning solutions containing alcohol, for example isopropyl alcohol, can cause imperfections in the photochromic coatings. Furthermore, it is customary to find that during the manufacture of said plastic lenses, an abrasion-resistant coating that is applied to the photochromic coating, or an anti-reflective coating that is applied to the abrasion-resistant coating, fails to pass the requirements of the invention. product, or in the case of ophthalmic lenses, does not meet commercially acceptable "cosmetic standards" for ophthalmic lenses. The cosmetic defects in a coated lens can include spots, scratches, inclusions, cracks and microcracks. When this occurs, it is economically desirable to remove the defective coating, for example, by chemical treatment with an aqueous caustic solution, and subsequently apply it to a new coating. In the process of chemical removal of the unacceptable coating, the underlying coatings, for example the photochromic coating, may be damaged, thereby destroying the value of the article, for example the lens. As is readily apparent to those skilled in the art, the sequential application of abrasion-resistant and anti-reflective coatings to the photochromic coating of an ophthalmic lens is one of the last in a series of multiple manufacturing steps, each of which adds value and they increase the cost of the lens that is being produced. Discarding the lens at this stage near the end of the production process because an added coating fails to meet the requirements of the product increases production costs and increases the final cost of the lens product. Therefore, it is economically desirable to avoid said product losses. In addition, some photochromic ophthalmic lens manufacturers wish to place their own abrasion and / or antireflective coatings on the photochromic coated lenses that another manufacturer has prepared. It is possible that the photochromic coating is scratched or stained as a result of packaging, transport, unpacking, cleaning or other physical handling of the lens during the preparation for the application of said abrasion and / or anti-reflective coatings. Accordingly, it is desirable that a lens that is transported to said manufacturers is resistant to scratches or other cosmetic imperfections that may be caused during the packaging, unpacking, transport, cleaning and / or handling of the coated photochromic lens, ie scratch-resistant.

In order to alleviate some of the above difficulties, it has been proposed to apply a film based on radiation-cured acrylate between the photochromic coating and the abrasion-resistant coating, to thereby reduce certain manufacturing problems associated with the removal of defects resistant coatings. abrasion and / or antireflective coatings of the photochromic coating, and to protect a photochromic coating that does not have an abrasion resistant coating during handling and transportation. The radiation-cured acrylate-based film is described as being (a) scratch-resistant, (b) resistant to treatment with diluted aqueous inorganic caustic solutions and (c) compatible with abrasion-resistant coatings, containing organosilane. During the application of the acrylate-based film to the photochromic coating, a polymerizable acrylic composition containing a photoinitiator is used. Generally, photoinitiating compounds have an aromatic ring in their structure that effectively absorbs ultraviolet light. In addition, they are usually of low molecular weight to improve their solubility in the radiation curable composition, and consequently they are relatively volatile when subjected to heat. These characteristics can cause yellowing of the cured composition and produce unpleasant odors respectively when the curable and cured composition containing the photoinitiator is subjected to heat and light during and after curing. In addition, it is known that unreacted or decomposed photoinitiators remain in the cured composition after curing, and if the cured composition is contacted with water, the unreacted photoinitiator oozes out. It is therefore desirable to use a radiation curable coating composition that does not require a photoinitiator for curing or that requires minor amounts of a photoinitiator that are generally used in radiation curable coating compositions. It has now been discovered that coatings / films comprising dendritic polyester acrylate can be radiation cured without using a photoinitiator, or can be cured by radiation using only small amounts of photoinitiator, and that said coating / film, when placed between the polymeric coating Photochromic and abrasion resistant coating can substantially attenuate the manufacturing problems described above. The dendritic polyester acrylate / film coating adheres to the photochromic coating, is typically harder than the photochromic coating, and is compatible with abrasion resistant coatings comprising an organosilane material; that is to say, the applied abrasion-resistant coating has no microcracks, ie it has fine cracks. According to an embodiment of the present invention, there is contemplated a photochromic article, for example a lens, which comprises in combination: (a) a rigid transparent substrate; (b) a photochromic organic polymeric coating added to at least a portion of at least one surface of said polymeric substrate, said polymeric coating comprising at least one organic photochromic material; and (c) a cured transparent film comprising dendritic polyester acrylate consistently added to said photochromic polymeric coating. In another embodiment of the present invention, the photochromic article described above is contemplated which additionally comprises an abrasion resistant coating, such as a hard coating comprising an organosilane, added to the exposed surface of the cured dendritic polyester acrylate film. In a further embodiment of the present invention, a photochromic article having an antireflective coating applied to the abrasion resistant coating is contemplated. Other coatings, such as antistatic and / or anti-wetting coatings can also be applied to the antireflective coating. In yet another embodiment of the present invention, an ophthalmic photochromic article is contemplated which comprises, in combination: (a) a transparent organic plastic substrate, such as a thermostable substrate prepared from a polymerizable composition comprising an allyl diglycol carbonate, for example diethylene glycol bis (allyl carbonate), a substrate prepared from thermoplastic polycarbonate, a substrate prepared from a polyurea urethane or a substrate prepared from compositions comprising the reaction product of isocyanate or polyfunctional isocyanates and / or isothiocyanate or isothiocyanates with polythiols or monomer or monomers of polyepisulfide; (b) an optically transparent photochromic organic polymeric coating, such as an acrylic based photochromic coating, based on polyurethane, based on polyureaurethane, based on aminoplast resin or based on polyepoxy, added to at least one surface of said plastic substrate, said polymeric coating a photochromic amount of at least one organic photochromic material; (c) an optically transparent, radiation-cured layer, for example a film, comprising dendritic polyester acrylate coherently adhered to said photochromic coating; and (d) optionally an abrasion resistant coating, such as a hard coating comprising an organosilane adhered to said layer of dendritic polyester acrylate. In a further contemplated embodiment, an antireflective coating adheres to said abrasion resistant coating, assuming that the abrasion resistant coating is present. DETAILED DESCRIPTION OF THE INVENTION According to the present invention, photochromic articles are provided - comprising, in combination, a rigid substrate, for example a transparent substrate such as glass or an organic polymeric material; a photocromo polymeric coating fixed to at least a portion of at least one surface of the substrate; and a layer, eg, coating / film, comprising dendritic polyester acrylate superimposed on, for example, adhered to the photochromic coating. The dendritic polyester acrylate film is typically (a) harder than the photochromic coating, for example it is less likely to be penetrated, surface scratched or scratched than the photochromic coating when rubbed or discarded, and desirably (b) ) compatible with abrasion resistant coatings, which contain organosilane. For the purposes of this specification (in others other than the operative examples), unless otherwise indicated, all numbers expressing quantities and ranges of ingredients, reaction conditions, etc., such as those expressing Refractive indexes and wavelengths, should be understood as modified in all cases by the term "approximately". Accordingly, unless otherwise indicated, the numerical parameters indicated in this specification and the appended claims are approximations that may vary depending on the desired properties desired by the present invention. Finally, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter must be understood at least in light of the number of significant digits presented and applying ordinary rounding techniques. In addition, as used in this specification and the appended claims, the singular forms of "a," "an," and "the" are intended to include plural referents unless expressly and unequivocally limited to a single referent. . As used herein, the term "cure", "cure" or similar terms, as used in connection with a cured or curable composition, for example a "cured composition" of some specific description, is intended to mean that at least one portion of the polymerizable and / or crosslinkable components forming the curable composition is at least partially polymerized and / or crosslinked. In certain embodiments, the crosslinking density of the crosslinkable components, for example the degree of crosslinking can vary from 5% to 100% complete crosslinking. In other embodiments, the crosslink density may vary from 35% to 85%, for example from 50% to 85%, of complete crosslinking. The degree of crosslinking can vary between any combination of values indicated above, including the values quoted. Regardless of the numerical ranges and parameters that set out the broad scope of the invention are approximations, the numerical values shown in the specific examples are presented as accurately as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective test measurements. The specific mention in this specification to patent applications, published or granted patents and published articles, such as the descriptions in the identified patents referred to by the column and line number, which describe relevant methods for the preparation of monomers, polymers, coatings, articles of manufacture, photochromic compounds, etc. they are incorporated into this document, in its entirety, as a reference. According to an embodiment of the present invention, a layer for example a film comprising cured dendritic polyester acrylate is superposed on, for example coherently adheres to, the photochromic polymeric coating. Macromolecules of the non-acrylate dendritic polyester type are described in U.S. Patent Nos. 5,418,301, 5,663,247, 6,225,404 Bl and U.S. 2002/0151652 Al, among others. These macromolecules are typically three-dimensional molecules that have a tree-like structure. As used herein, the terms "dendritic polyester-type macromolecules" and "dendritic polyester-type oligomers" (or terms of similar importance) are meant to include hyperbranched dendritic macromolecules and dendrimers. The dendrimers are highly symmetric, while similar macromolecules called hyperbranched can maintain an asymmetry to a certain degree, still maintaining a very branched tree type structure. It can be said that the dendrimers are monodisperse or substantially monodisperse hyperbranched dendritic macromolecules. The hyperbranched dendritic polyester macromolecules typically comprise an initiator or core having one or more reactive sites or functions and numerous branching layers and finally one or more spacer layers and / or a layer of chain terminator molecules. The continuous replication of the branched layers usually results in the increase of the multiplicity of branches and, when applicable or desirable, the increase in the number of terminal functions. The layers are usually called generations and the branches are dendrons. The hyperbranched dendritic macromolecules (dendrimers) can be illustrated by the formulas described in column 6 lines 8 to 30 of U.S. Patent No. 6,225,404 Bl. In those formulas, X and Y are initiators or cores that have four and two reactive functions, respectively, and A, B and C are branch chain extenders that have three (A and C) and four (B) reactive functions, each branch chain extender forming a generation of branching in the macromolecule. T in the formulas mentioned above is a terminating chain stop element or a suitable terminal function or site, such as hydroxyl, carboxyl or epoxide groups. A dendron can be produced previously and then added to a kernel. A dendron can be produced for example by condensing one or more hydroxy functional carboxylic acids at normal esterification temperatures, allowing the mono, di, tri or polyfunctional carboxylic acids to form ester bonds with mono, di, tri or polyfunctional alcohols or epoxides or by similar procedures resulting in ester bonds, ether bonds or other chemical bonds. The raw materials used to produce a dendron are chosen to provide at least one terminal reactive site to react with a core or initiator. Dendritic macromolecules of the polyester type are typically constructed from ester or polyester units optionally in combination with ether or polyether units. The hyperbranched dendritic macromolecule comprises a monomeric or polymeric core having at least one epoxide reactive group, hydroxyl, carboxyl or anhydride, to which nuclei 1 to 100, usually 1 to 20, for example 2 to 8, branching generations comprising at least one monomeric or polymeric branching chain extender having at least three are added reactive groups, of which at least one is a hydroxyl group and at least one is a carboxyl or anhydride group, and optionally at least one spacer generation comprising at least one chain extender. The spacer chain extender is desirably a compound having two reactive groups, one which is the hydroxyl group and one which is a carboxyl or anhydride group or is an internal ether such as a lactone or a similar compound. The terminal chain extender functions of the hyperbranched dendritic macromolecule are substantially hydroxyl, carboxyl or anhydride groups and the hyperbranched dendritic macromolecule is optionally, fully or partially a chain terminated by at least one monomeric or polymeric chain stop element and / or is functionalized Dendritic polyester type macromolecules are well defined, highly branched macromolecules that radiate from a central core and, as analyzed, are synthesized by a stepwise repetitive branching reaction sequence. The repetitive branching sequence typically guarantees a complete coating for each generation, leading to macromolecules that are typically monodisperse. Synthetic procedures for the preparation of dendritic polyester macromolecule often provide an almost complete pontrol on size, shape, surface / interior chemistry, flexibility and topology. The macromolecule of dendritic polyester can have complete and asymmetric branches as well as incomplete and asymmetric branches. Non-limiting examples of central initiator molecules for polyester type dendritic macromolecules include aliphatic, cycloaliphatic or aromatic diols, triols, tetraols, sorbitol, mannitol, dipentaerythritol, a reaction product of di-, tri- or polyalcohol and an alkylene oxide , for example, ethylene oxide, propylene oxide and butylene oxide having a molecular weight less than 2000. Non-limiting examples of suitable diols include 1,3-propanediol, a dimer, trimer or polymer of 1,3-propanediol , a 2-alkyl-1,3-propanediol, a 2,2-dialkyl-1,3-propanediol, such as 2-butyl-2-ethyl-1,3-propanediol, a 2-hydroxy-2-alkyl- 1, 3-propanediol, a 2,2-di (hydroxyalkyl) -1,3-propanediol, a 2-hydroxyalkoxy-2-alkyl-1,3-propanediol, a 2,2-di (hydroxyalkoxy) -1,3 -propanediol, 1,2-propanediol, 1,3-butanediol, 1,2-ethanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol, trimethylolethane, ditrimethylolpropane, 1,6-hexanediol and polytetrahydrofuran. The alkyl groups of the initiator molecules are typically C x to C 2 alkyl groups, for example Ci to C 4. The polyester chain extenders are monofunctional carboxylic acids having at least two hydroxyl groups such as, but not limited to, dimethylolpropionic acid, a, a-bis (hydroxy) propionic acid, a, a-bis (hydroxymethyl) propionic acid, a, a-bis (hydroxymethyl) butyric, a, -bis (hydroxymethyl) valeric acid, a, a, a-tris (hydroxymethyl) acetic acid, a, a-bis (hydroxymethyl) butyric acid, a, b-dihydroxy acid propionic acid, heptonic acid, citric acid, d- or 1-tartaric acid or a-phenylcarboxylic acids such as 3,5-dihydroxybenzoic acid. Chain terminating agents, which can be used, include saturated monofunctional carboxylic acids, saturated fatty acids, unsaturated monofunctional carboxylic acids, monofunctional aromatic carboxylic acids, such as benzoic acid and difunctional or polyfunctional carboxylic acids or anhydrides thereof, one example of said Acid is behenic acid. The terminal hydroxyl groups in the polyester chain extender can be reacted with chain stop elements with or without functional groups. Dendritic polyester macromolecules are commercially available from Perstorp Specialty Chemicals, Perstorp, Switzerland, with the denomination dendritic macromolecules BOLTORN® H20, H30 and H40, said macromolecules being functionalized with hydroxy groups in their periphery. These materials have a weight average molecular weight in the range of 1,000 to 4,000. The BOLTORN® H20, H30 and H40 materials have an average of 16, 32 and 64 hydroxy groups respectively in the periphery of the macromolecule. The dendritic polyester macromolecule materials can be acrylated by known esterification techniques to provide material used to form the dendritic polyester acrylate film described herein. See, for example, the descriptions in International Patent Publications WO 00/77070 A2 and WO 00/64975. The acrylation, recovery and purification of the acrylated dendritic polyester macromolecule can be suitably performed using well-known methods from the literature, for example as described in Kirk-Othmer Encyclopedia of Chemical Technology-1980 Vol. 1, pages 386-413, "Acrylic Ester Polymers". Acrylation is typically a direct reaction, such as esterification, with acrylic acid, methacrylic acid, crotonic acid (α-methacrylic acid) and / or a direct reaction with an anhydride and / or a halide corresponding to said acrylic acid, usually at a molar ratio of hydroxyl groups for said acid, anhydride and / or halide of between 1: 0.1 and 1: 5, more usually between 1: 0.5 and 1: 1.5. Typically, the acrylating agent is used in a stoichiometric molar excess. Other acrylating agents include, for example, acrylates with epoxide or anhydride and methacrylate functionality such as glycidyl methacrylate. The acrylated dendritic polyester macromolecule can have a variable percentage of functional acrylic acid groups, for example hydroxyl groups that have been acrylated. Said percentage may vary from 5 to 100%, based on the initial hydroxyl content. Often, the percentage will vary from 20 to 90%, from 40 to 85%, such as from 45 to 80%. The percentage of acrylated hydroxyl groups can vary between any combination of these percentages, including the percentages quoted. The esterification step is typically carried out in the presence of a solvent such as an apolar organic solvent, examples of which include, but are not limited to, heptane, cyclohexane, toluene, benzene, xylene or mixtures of such solvents. The esterification is conveniently carried out in the presence of a catalyst such as p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, trifluoroacetic acid, sulfuric acid, phosphoric acid, naphthalenesulfonic acid, Lewis acids such as BF3, A1C13, SnCl4, titanates such as tetrabutyl titanates and organotin compounds. The acrylation step is typically carried out at temperatures of 50 to 200 ° C, more usually 80 to 150 ° C, depending on the selected solvent and the pressure at which the acrylation step is performed. The acrylation step can be carried out in the presence of a radical polymerization inhibitor such as methyl ether hydroquinone, hydroquinone, phenothiazine, di-t-butyl hydroquinone or a mixture of said inhibitors. According to the description of International Patent Publication WO 00/64975, the dendritic polyester macromolecule can be mixed with an organic alcohol, for example an aliphatic alcohol having one or more hydroxyl groups and a molecular weight of less than 2000, by example from 60 to 1500 or from 100 to 1000, before the acrylation stage because the dendritic polyester macromolecules are generally viscous liquids. Typically, alcohol is a liquid at temperatures of 20 to 50 ° C or produces liquid mixtures with said dendritic polyester macromolecule at said temperature. The alcohol can be a diol such as ethylene glycol, a 1,2- or 1,3-propylene glycol, a butanediol or a di-, tri- or polyglycol such as a diethylene glycol, a polypropylene glycol or a polymeric glycol such as a polymer comprising one or more ethylene glycols and one or more propylene glycols. The macromolecule of dendritic polyester and alcohol can be blended in a weight ratio of dendritic polyester to alcohol of between 90:10 and 10:90, such as between 25:75 and 75:25 or between 40:60 and 60:40, example 50:50. The acrylation of the mixture produces an acrylate composition comprising at least one dendritic polyester acrylate and at least one acrylate monomer. The weight ratio of dendritic polyester macromolecule and alcohol can vary between any combination of the cited values, including the specified values. As used in the present description and claims, the term "dendritic polyester acrylate" (or a term of similar importance) is intended to mean and include the composition produced by acrylating a macromolecule of the dendritic polyester type or by acrylating a macromolecule of the dendritic polyester type containing a viscosity reducing material having a group that is acrylated during the acrylation step, for example one or more alcohols having one or more hydroxyl groups. The expression "Dendritic polyester acrylate film" (or a term of similar importance) is intended to mean and include the film produced by the radiation curing of a composition comprising a dendritic polyester acrylate (as defined above) and a composition comprising a dendritic polyester acrylate and at least one other acrylic material curable by radiation or thermally, for example a composition of a mixture of dendritic polyester acrylate (as defined above) and monomer or (meth) acrylic monomers curable by radiation or thermally (hereinafter referred to collectively as a radiation curable material). The term "composition comprising a dendritic polyester acrylate" (or terms of similar importance) is intended to mean and include any such composition. It is also contemplated that a mixture of different dendritic polyester acrylates may be used in the compositions used to prepare the dendritic polyester acrylate film. Non-limiting examples of radiation-curable monomeric (meth) acrylic material or materials which can be incorporated into the dendritic polyester acrylate composition include monoacrylates and polyacrylates such as diacrylates, acrylates, tetraacrylates, pentaacrylates, etc. Typically contemplated are diacrylates, triacrylates and mixtures of said acrylates. The additional monomeric (meth) acrylic material or materials can be blended with the dendritic polyester acrylate composition in various proportions, depending on the physical properties of the desired film, for example viscosity of the mixture, the degree of crosslinking, and the hardness of the film. Typically, the weight ratio of the dendritic polyester acrylate (as defined above) to the additional (meth) acrylic monomeric material or materials can vary widely. In particular, the weight ratio can vary from 90:10 to 10:90, more particularly, from 70:30 to 30:70, for example from 40:60 to 60:40, such as 50:50. The ratio of the dendritic polyester acrylate to additional monomeric (meth) acrylic material can vary between any combination of the cited values including the specified values. As used herein, the terms "acrylic" and "acrylate" are used interchangeably (unless doing so alters the intended meaning) and include acrylic acid derivatives, as well as substituted acrylic acids such as ethacrylic acid, acid ethacrylic, etc., unless otherwise clearly indicated. The terms "(meth) acrylic" or "(meth) acrylate" are intended to cover both acrylic and acrylate and methacrylic and methacrylate forms of the indicated material, for example monomer. As in a contemplated embodiment, the dendritic polyester acrylate film is interposed between and is adjacent to the photochromic coating and the abrasion resistant coating, serves to join together these coatings and serves as a barrier to protect the photochromic coating. In such an embodiment, the dendritic polyester acrylate film can be referred to as a "tie layer". Non-limiting examples of acrylic monomers include polyacrylates, for example, di-, tri-, tetra- and penta-functional and monoacrylates, for example, a monomer containing a single acrylic functionality, hydroxy-substituted monoacrylates and alkoxysilyl alkyl acrylates such as trialkoxysilylpropylmethacrylate. . Many acrylates can be represented by the following general formula I, R "- [OC (0) C (R ') = CH2] n I wherein R" is an aliphatic or aromatic group containing from 2 to 20 carbon atoms and optionally from 1 to 20 alkyleneoxy bonds; R 'is hydrogen or an alkyl group containing 1 to 4 carbon atoms and n is an integer from 1 to 5. When n is greater than 1, R "is a linking group that binds the acrylic functional groups together. R 'is hydrogen or methyl and n is an integer from 1 to 3. More specifically, diacrylates (when n is 2) can be represented by general formula II, wherein Ri and R2 may be the same or different and each is selected from hydrogen or alkyl groups containing 1 to 4 carbon atoms, for example methyl, and A is a hydrocarbyl linking group of, for example, 1 to 20 carbon atoms, for example an alkylene group, one or more oxyalkylene groups [or a mixture of different oxyalkylene groups]; or a group of the following general formula III, wherein each R3 is a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, for example methyl; X is a halogen atom for example chlorine; a is an integer from 0 to 4, for example from 0 to 1, representing the number of substituted halogen atoms in the benzene ring; k and m are numbers from 0 to 20 for example to l to l5 or from 2 to! 0. The values of k and are average numbers and when they are calculated they can be a whole number or a fractional number. The acrylates having an epoxy group can be represented by the following general formula IV, wherein Ri and Re may be the same or different and each is selected from hydrogen or an alkyl group of 1 to 4 carbon atoms, for example methyl; R4 and R5 are alkylene groups containing from 2 to 3 carbon atoms, for example ethyleneoxy and propyleneoxy, and m and n are numbers from 0 to 20, for example from 0 or 1 to 15 or 2 to 10. When one of yn is 0 and the other is 1, the remaining group can be an aromatic group of the following formula V, for example, a group derived from the 2,2'-diphenylenepropane radical, said phenyl groups being able to be substituted with Ci to C4 alkyl groups or halogens, for example methyl and / or chloro. In the following detailed examples of monomeric, acrylic identified materials, the term "acrylate" is intended to mean and include the corresponding alkyl acrylates containing from 1 to 4 carbon atoms in the alkyl group, particularly the corresponding methacrylate; and where the alkyl acrylate, for example methacrylate is identified, the corresponding acrylate is contemplated. For example, reference to hydroxyethyl acrylate in the examples includes hydroxyethyl methacrylate, hydroxyethyl ethacrylate, etc .; and the reference to ethylene glycol diacrylate includes for example ethylene glycol dimethacrylate, ethylene glycol diethacrylate, etc. Non-limiting examples of said monomeric acrylic materials include: Hydroxyethyl acrylate, Hydroxypropyl acrylate, Hydroxybutyl acrylate, Hydroxy-poly (alkyleneoxy) alkyl acrylate, Caprolactone acrylate, Ethylene glycol diacrylate, Butanediol diacrylate, Hexanediol diacrylate, Hexamethylene diacrylate, Diethylene glycol diacrylate, Triethylene glycol diacrylate, tetraethylene glycol diacrylate, Polyethylene glycol diacrylate, Dipropylene glycol diacrylate, Tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, polypropylene glycol diacrylate, Glyceryl ethoxylate diacrylate, Glyceryl propoxylate diacrylate, Trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, Neopentyl glycol diacrylate, Neopentyl ethoxylated glycol diacrylate, neopentyl glycol propoxylate diacrylate , Monomethoxy trimethylolpropane ethoxylated diacrylate, Pentaerythritol ethoxylated tetraacrylate, Pentaerythritol propoxylated tetraacrylate, Dipentaer itritol pentaacrilato, Dipentaerythritol ethoxylated pentaacrilate, Dipentaerythritol propoxylated pentaacrilate, Di-trimethylolpropane ethoxylated tetraacrylate, Bisphenol A ethoxylated diacrylate containing 2 to 20 ethoxy groups, Bisphenol A propoxylated diacrylate containing 2 to 20 propoxy groups, Bisphenol A alkoxylated diacrylate containing a mixture of 2 to 20 ethoxy and propoxy groups, Bisphenol A glycerolate dimethacrylate, Bisphenol A glycerolate (1 glycerol / 1 phenol) dimethacrylate, Glycidyl acrylate / 5-methylglycidyl acrylate, bisphenol A-monoglycidyl ether acrylate, 4-glicidiloxibutil methacrylate, 3- (glycidyl-2-oxyethoxy) -2-hydroxypropyl methacrylate, 3- (glycidyloxy-1-isopropyloxy) -2-hydroxypropyl acrylate, 3- (glycidyloxy-2-hydroxypropyloxy) -2-hydroxypropyl acrylate, 3- (trimethoxysilyl) propyl methacrylate. In a further embodiment of the present invention, it is contemplated that other reactive monomers / diluents, such as monomers containing a thermally polymerizable ethylenic or allylic functional group or radiation (other than the acrylic functional group) may also be present. Examples of such materials include, but are not limited to, radiation curable vinyl compounds, for example vinyl ethers. It is contemplated that these reactive monomers / diluents may be present in amounts of up to 30 or 40 percent by weight, for example from 0 to 40 percent (based on resin solids), such as from 0 to 10 or 20 weight percent of the composition comprising the dendritic polyester acrylate. The amount of reactive monomers / diluents can vary between any of the specified amounts including the cited values. Compounds having vinyl ether groups that can be used in the radiation curable dendritic polyester acrylate composition include, but are not limited to, alkyl vinyl ethers having a terminal group substituted with hydrogen, halogen, hydroxyl, and amino atoms / groups; a cycloalkyl vinyl ether having a terminal group substituted with hydrogen, halogen, hydroxyl and atoms / amino groups; monovinyl ethers, divinyl ethers and polyvinyl ethers in which a vinyl ether group is connected with an alkylene group; and wherein a vinyl ether group is connected to at least one group with and without substituents selected from alkyl, cycloalkyl and aromatic groups, by at least one linkage selected from an ether linkage, a urethane linkage and an ester linkage. Examples of such compounds include, but are not limited to, methyl vinyl ether, hydroxymethyl vinyl ether, chloromethyl vinyl ether, ethyl vinyl ether, 2-hydroxyethyl vinyl ether, 2-chloroethyl vinyl ether, diethyl aminoethyl vinyl ether, propyl vinyl ether, 3-hydroxypropyl. vinyl ether, 2-hydroxypropyl vinyl ether, 3-chloropropyl vinyl ether, 3-aminopropyl vinyl ether, isopropyl vinyl ether, butyl vinyl ether, 4-hydroxybutyl vinyl ether, isobutyl vinyl ether, 4-aminobutyl vinyl ether, pentyl vinyl ether, isopentyl vinyl ether, hexyl vinyl ether, 1,6-hexanediol monovinyl ether, heptyl vinyl ether, 2-ethylhexyl vinyl ether, octyl vinyl ether, isoctyl vinyl ether, nonyl vinyl ether, isononyl vinyl ether, decyl vinyl ether, isodecyl vinyl ether, dodecyl vinyl ether, isododecyl vinyl ether, tridecyl vinyl ether, isotridecyl vinyl ether, pentadecyl vinyl ether, isopentadecyl vinyl ether, hexadecyl vinyl ether, octadecyl vinyl ether, methylene glycol divinyl ether, ethylene glycol divinyl ether, propyl glycol divinyl ether, 1-butanediol divinyl ether, 1,6-hexanediol divinyl ether, cyclohexanediol divinyl ether, trimethylolpropane trivinyl ether, and pentaerythritol tetravinyl ether.

Cycloalkyl vinyl ethers include, but are not limited to, cyclopropyl vinyl ether, 2-hydroxycyclopropyl vinyl ether, 2-chlorocyclopropyl vinyl ether, cyclopropylmethyl vinyl ether, cyclobutyl vinyl ether, 3-hydroxycyclobutyl vinyl ether, 3-chlorocyclobutyl vinyl ether, cyclobutylmethyl vinyl ether, cyclopentyl. vinyl ether, 3-hydroxycyclopentyl vinyl ether, 3-chlorocyclopentyl vinyl ether, cyclopentylmethyl vinyl ether, cyclohexyl vinyl ether, 4-hydroxycyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, 4-aminocyclohexyl vinyl ether, cyclohexanediol monovinyl ether, cyclohexanedimethanol monovinyl ether, and cyclohexanedi ethanol divinyl ether. Other non-limiting examples of vinyl ethers that can be used include ethylene glycol methyl vinyl ether, diethylene glycol monovinyl ether, diethylene glycol methyl vinyl ether, diethylene glycol divinyl ether, triethylene glycol monovinyl ether, etc. See, for example, the vinyl ethers specified in column 19, line 26 to column 20, line 27 of U.S. Patent No. 6,410,611 Bl. The above-described amounts of additional acrylate monomers and other reactive monomers / diluents are based on the total amount of polymerizable materials (resin solids) comprising the film composition containing curable dendritic polyester acrylate, not including other components such as non-polymerizable organic diluents for example solvents, photoinitiators, stabilizers, plasticizers and other similar components. The total of all the various polymerizable materials comprising the curable film composition will of course be equal to 100 percent. Radically curable (meth) acrylic materials are typically commercially available; and if they are not available in the market, they can be prepared by methods well known to those skilled in the art. Examples of commercial acrylate materials can be found in U.S. Patent No. 5,910,375, particularly the description found in column 8, lines 20-55 and column 10, lines 5-36. Acrylate materials available on the market are available from various manufacturers and include those marketed under the names SARTOMER, EBECRYL, and PHOTOMER. As described in the U.S. patent application Serial No. xx / xxx.xxx in the filing with the present filed on the same date it is by W. Blackburn et al and entitled "Photochromic Optical Article", it is contemplated that an enhancing amount of the adhesion of at least one adhesion promoter material (adhesion promoter) can be incorporated into the composition comprising the dendritic polyester acrylate. By "adhesion enhancing amount" it is meant that the compatibility of the dendritic polyester acrylate film with abrasion resistant coating containing organosilane superimposed (as described herein) is applied to the dendritic polyester acrylate film. Typically, 0.1 to 20 weight percent of at least one adhesion promoter is incorporated into the dendritic polyester acrylate composition before it is applied to the photochromic coating. More particularly, from 0.5 to 16, for example from 0.5 to 10 weight percent, more particularly from 0.5 to 8, for example 5 weight percent of at least one adhesion promoter is incorporated into the composition of polyester acrylate. The amount of adhesion promoter incorporated into the dendritic polyester acrylate composition can vary between any combination of the values mentioned above, including the values quoted. Among the adhesion promoter materials that can be incorporated into the dendritic polyester acrylate film to enhance its compatibility with an abrasion resistant coating, for example an abrasion resistant coating comprising organosilane material include but not limited to organosilane materials adhesion promoters such as aminoorganosilanes and silane coupling agents, organic titanate coupling agents and organic zirconate coupling agents. The aminoorganosilanes that can be used are primary, secondary and tertiary aminoorganosilanes, particularly aminoorganosilanes represented by the following general formula VI: Rl "(RO) 3-" - S 1i-R, 2-N- (R33) R <; 4 VI where n is an integer from 0 to 2, usually O or l; each R is independently selected from Ci-Cß alkyl, usually C?-C4 alkyl such as methyl, ethyl, propyl and butyl, a C?-C4 alkoxy C alquilo-C8 alkyl, typically C alco-C3 alkoxy C alquilo-C3 alkyl such as methoxymethyl, methoxyethyl, ethoxymethyl, etc. or Cß-Cι aryl, for example, C 6 -C 8 aryl; R 1 is hydrogen, a C 1 -C 4 alkyl, usually C 1 -C 3 alkyl or Cg-C 10 aryl, for example C 6 -C 8 aryl; R2 is a divalent Ci-Cio alkylene, C2-C ?o or phenylene alkylene, usually a C2-C5 alkylene such as ethylene, trimethylene, etc., or C2-C5 alkylene such as vinylene, 1-propenylene, butenylene, 2-pentenylene , etc.; each R3 and R4 are independently selected from hydrogen, Ci-Cg alkyl, usually C?-C3 alkyl, C?-C8 hydroxyalkyl, typically C2-C3 hydroxyalkyl, C?-C8 aminoalkyl, typically C2-C3 aminoalkyl, CC cycloalkyl, example C5-C6 cycloalkyl, Cß-Cι aryl for example C 6 -C 8 aryl, (meth) acryloxy C? ~C alkyl (the alkyl group being optionally substituted by a functional group such as hydroxy), for example (meth) acryloxy-2 -hydroxypropyl, or R3 and R4 combine to form a cycloalkyl group of 4 to 7 carbon atoms for example of 5 to 6 carbon atoms or a C4-C heterocyclic group in which the heteroatoms or atoms is an oxygen and / or Nitrogen eg morpholine and piperazine or are a group represented by the formula VIA R'p I 2 (RO) 3-n-Si-R2-VIA where R, R1, R2 and n are as defined with respect to the general formula VI. Also included are compounds of formula VI and the partial and total hydrolysates of the compounds represented by the formula. Nonlimiting examples of aminosilanes gue can be used include aminopropyl trimethoxysilane, aminopropyl triethoxysilane, aminoethyl trimethoxysilane, aminoethyl triethoxysilane, trimethoxysilane inopropil methylates, aminobutilmetil dimethoxysilane, ethoxysilane aminopropildimetil, aminopropylmethyl dimethoxysilane, ethoxysilane aminopropildimetil, aminobutilmetil dimethoxysilane, bis- (gamma-trimethoxysilylpropyl) amine, N- (3-methacryloxy-2-hydroxypropyl) -3-aminopropyl triethoxysilane, N- (3-acryloxy-2-hydroxypropyl) -3-aminopropyl triethoxysilane, (N, -dimethylaminopropyl) trimethoxysilane, (N, N-diethyl-3- to inopropyl) trimethoxysilane, diethylaminomethyl triethoxysilane, bis (2-hydroxyethyl) -3-aminopropyl triethoxysilane,? -aminopropyltrimethoxysilane, N- (2'- to inoethyl) ) -3-aminopropyl trimethoxysilane, N ~ (2'-aminoethyl) -3- to inopropyl triethoxysilane, N-butyl-3-aminopropyl triethoxysilane, N-octyl-3-aminopropyltrimethoxysilane, N-cyclohexyl-3-aminopropyl-triethoxysilane, N - (3'-triethoxysilylpropyl) -piperazine, bis- (3-triethoxysilylpropyl) amine, tris- (3-trimethoxysilylpropyl) amine, N, N-dimethyl-3-aminopropyl triethoxysilane, N-methyl-N-butyl-3-aminopropyl triethoxysilane, N- (3'-aminopropyl) -3-aminopropyl triethoxysilane, N- (3'-triethoxysilylpropyl) morpholine, N-phenyl-gamma-aminopropyltrimethoxysilane, and N-phenyl-gamma-amino-2-methylpropytrimethoxysilane. The silane coupling agents can be represented by the following general formula VII: (R5) a (R6) bSi [(0R) 3Jc VII wherein each R5 is an organofunctional group independently chosen from epoxy, glycidoxy, amino, vinyl, styryl , (meth) acryloxy, mercapto, haloalkyl, for example chloroalkyl, ureido, or a hydrocarbon radical having no more than 10 carbon atoms substituted with said organofunctional group; each R6 is a hydrocarbon radical of not more than 20 carbon atoms which is independently chosen from aliphatic radicals, aromatic radicals or mixtures of said hydrocarbon radicals, for example C alquilo-C20 alquilo alkyl, more particularly C C1-C10 alquilo alkyl for example Ca-alkyl. C? or phenyl; each R is independently selected from C alquilo-C alquilo alkyl, usually C?-C alkyl such as methyl ethyl propyl and butyl, a Cx-Cs alkoxy, typically C?-C3 alkoxy, C ~C3 alkyl, such as methoxymethyl, methoxyethyl, ethoxymethyl, etc., C6-C aryl or for example C6-C8 aryl or acetoxy; a is an integer 1 or 2 normally 1, b is the integer 0, 1 or 2 for example 0 and c is the integer 1, 2 or 3 for example 2 or 3, with the proviso that the sum of a + b + c equals 4. Non-limiting examples of silane coupling agents include: vinyl triacetoxysilane, vinyl trimethoxysilane, vinyl tri (2-methoxyethoxy) silane, vinyl triphenoxysilane, vinyl triisopropoxysilane, vinyl tri-t-butoxysilane, divinyl diethoxysilane , gamma glycidoxypropyl trimethoxysilane, beta- (3,4-epoxycyclohexyl) ethyl trimethoxysilane, allyl triethoxysilane, allyl trimethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, (3-acryloxypropyl) methyldimethoxysilane, (3-acryloxypropyl) trimethoxysilane, (3-methacryloxypropyl) trimethoxysilane, (methacryloxymethyl) ethoxysilane dimethyl, methacryloxymethyl triethoxysilane, trimethoxysilane methacryloxymethyl, methacryloxypropyl ethoxysilane dimethyl trimethoxysilane methacryloxypropyl trimethoxysilane estiriletil, mercaptomethyl methyldiethoxysilane, 3-ercaptopropyl methyldimethoxysilane, 3-mercaptopropyl triethoxysilane, 3-mercaptopropyl trimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, dimethyl diethoxysilane, chloropropyltriethoxysilane, 3- (trimethoxysilyl) propylmethacrylate, ureidopropyltriethoxysilane, mixtures of such silane and less partial hydrolysates of said silanes. Non-limiting examples of titanate coupling agents include: tetra (2,2-diallyloxymethyl) butyl titanate, di (ditridecyl) phosphite titanate (commercially available as KR 55 from Kenrich Petrochemicals, Inc.); neopentyl (diallyl) oxy trineodecanoyl titanate; neopentyl (diallyl) oxy tri (dodecyl) benzene sulfonyl titanate; neopentyl (diallyl) oxy tri (dioctyl) phosphate titanate; neopentyl (diallyl) oxy tri (dioctyl) pyro-phosphate titanate; neopentyl (diallyl) oxy tri (N-ethylenediamino) ethyl titanate; neopentyl (diallyl) oxy tri (m-amino) phenyl titanate; neopentyl (diallyl) oxy trihydroxy caproyl titanate; isopropyl dimethylacrylisostearoyl titanate; tetraisopropyl (dioctyl) phosphite titanate; mixtures of said titanates and at least partial hydrolysates thereof. Non-limiting examples of organic zirconate coupling agents include tetra (2,2-diallyloxymethyl) butyl di (ditridecyl) phosphite zirconate (commercially available as KZ 55 from Kenrich Petrochemicals); neopentyl (diallyloxy) trineodecanoyl zirconate; neopentyl (diallyl) oxy tri (dodecyl) benzene sulfonyl zirconate; neopentyl (diallyloxy) tri (dioctyl) phosphate zirconate; neopentyl (diallyloxy) tri (dioctyl) pyro-phosphate zirconate; neopentyl (diallyloxy) tri (N-ethylenediamine) ethyl zirconate; neopentyl (diallyloxy), tri (m-amino) phenyl zirconate; neopentyl (diallyloxy) tri ethacryl zirconate; neopentyl (diallyloxy) triacryl zirconate; dyneopentyl (diallyloxy) di (p-amino) benzoyl zirconate; dyneopentyl (allyl) oxy di (3-mercapto) propionic zirconate; mixtures of said zirconates and at least partial hydrolysates thereof.

As used in this description and in the claims, the expression "at least partial hydrolysates" is intended to mean and include compounds that are partially hydrolyzed or fully hydrolyzed. As described above, the dendritic polyester acrylates can be cured without using photoinitiators. In addition, it is contemplated that the compositions described herein comprising the dendritic polyester acrylate can also be cured without using photoinitiators. However, the use of small amounts of one or more photoinitiators will enhance the curing speed and provide a more complete cure in a shorter amount of time. Accordingly, it is contemplated that the curable dendritic polyester acrylate composition may also contain at least one photoinitiator. A photoinitiator is not necessary when the resin formulation is to be cured by an electron beam process. When used, the photoinitiator is present in sufficient amounts to initiate and sustain the curing of the composition, for example, an initiating or photoinitiating amount. Photoinitiators are desirably used in the least amount necessary to obtain the initiation of the curing process. Generally, the photoinitiator or photoinitiators may be present in amounts of 0.1 to 10 weight percent such as 0.5 to 6 weight percent, more generally 1 to 4 weight percent, based on the total weight of the polymerizable photoinitiated components in the curable dendritic polyester acrylate film composition. The photoinitiators are analyzed and described later in connection with the photochromic polymeric coating. This analysis is applicable here also in relation to the radiation curable dendritic polyester acrylate composition and is incorporated herein. Additional examples of commercial photoinitiators can be found in column 19, lines 38-43 of U.S. Patent No. 5,910,375 and in column 11, lines 24-65 of U.S. Patent 6,271,339 Bl. The dendritic polyester acrylate film forming composition may contain ultraviolet light stabilizers which may be an ÜV absorber and / or a hindered amine light stabilizer (HALS). Non-limiting examples of UV absorbers including benzotriazoles and hydroxybenzophenones. Care must be taken, however, in the case of UV absorbers, that sufficient UV radiation of the appropriate wavelength is allowed to pass through the layer containing the maleimide derivative to activate the photochromic material or materials within the polymeric coating. photochromic HALS stabilizers are available in Ciba-Geigy under the trade name TINüVIN. The amount of light stabilizer that is used is that amount which is effective to stabilize the composition, i.e., an effective amount which will depend on the specific compounds chosen, although typically it is up to 20 parts by weight with respect to 100 parts by weight of the polymerizable resin components. The UV absorber is also used in effective amounts, which is typically up to 10 parts by weight, for example 0.05 to 5 parts by weight, relative to 100 of the polymerizable resin components. The dendritic polyester acrylate film-forming composition may include other additives known to those skilled in the art. These additives may include, but are not limited to, solvents if appropriate viscosity, flow and level additives, wetting agents, antifoaming agents, rheology modifiers, surfactants, e.g., fluorosurfactants, stabilizers, and antioxidants need to be achieved. Such materials are well known to those skilled in the art and examples of some commercial surfactants and antioxidants / stabilizers can be found in column 10, lines 43-54 of the aforementioned "375 Patent". Other non-limiting examples of such additives include silicones, modified silicones, silicone acrylate, hydrocarbons and other compounds containing fluorine. The curable dendritic polyester acrylate film-forming composition is prepared by mixing two components of the composition at temperatures that facilitate mixing and blending. The composition can then be applied to the photochromic coating by the same procedures described below for the application of the photochromic coating to the plastic substrate, for example spin coating and dip coating. Before applying the dendritic polyester acrylate composition to the photochromic coating it is usual, but not necessary, to treat the surface of the photochromic coating to enhance the adhesion of the dendritic polyester acrylate film to the photochromic coating. Effective treatments include treatment with activated gas such as a treatment with a low temperature plasma or corona discharge. A particularly desirable surface treatment is a plasma treatment at low temperature. This method allows the treatment of the surface to enhance the adhesion of a film or overlay, and is a clean and effective way to alter the physical surface, for example, roughening and / or chemically altering the surface without affecting the rest of the article. . Inert gases such as argon and reactive gases such as oxygen have been used as a plasma gas. The inert gases will roughen the surface while reactive gases such as oxygen will roughen and chemically alter the surface exposed to the plasma, for example by producing hydroxyl or carboxyl units on the surface. Oxygen is used as the plasma gas in a contemplated embodiment because it is considered to provide a light but effective physical roughness of the surface along with a light but effective chemical modification of the surface. Naturally, the extent of the surface roughness and / or chemical modification will be a function of the plasma gas and the operating conditions of the plasma unit (including the amount of treatment time). It is reported that a conventional plasma treatment alters the upper 20 to 200 angstroms of the surface (a few molecular layers). The operating conditions of the plasma unit are a function of the design and size, for example volume of the plasma chamber, power and construction of the plasma unit. The frequency at which the plasma operates may vary, for example, from a low frequency such as 40 kHz to microwave frequencies such as 2.45 GHz. Similarly, the power at which the plasma unit operates may vary, for example. from 50 to 1000 watts, for example from 50 to 750 such as from 50 to 150 watts. The pressure at which the plasma unit works may also vary; however, it has been observed that low pressures are generally less physically destructive to the treated surface, which is desirable. Low pressures, for example from 20 to 65 or 70 Pa, are thought to be useful. The time that the surface is exposed to the plasma can also vary and will be a function of the type of surface to be treated, i.e. the type of polymer used for the photochromic polymeric coating. However, care must be taken that the surface is not treated for too long periods of treatment that may be counterproductive. One skilled in the art can easily determine the minimum time required to provide a plasma treated surface that enhances the adhesion of the dendritic polyester acrylate film to the photochromic coating. For ophthalmic articles, such as lenses, the duration of plasma treatment will generally vary from 1 to 10 minutes, for example from 1 to 5 minutes. A contemplated plasma treatment involves the use of an oxygen plasma generated by a Plasmatech machine operating at a power level of 100 watts from 1 to 10, for example, from 1 to 5 minutes, while introducing 100 ml / minute of oxygen in the vacuum chamber of the Plasmatech machine. The surface of the coating or article subjected to plasma treatment will typically be at room temperature; however, if desired, the surface can be slightly preheated. It should be noted that plasma treatment will tend to increase the surface temperature (and of the treated article.) Consequently, the surface temperature during the treatment will be a direct function of the duration of the plasma treatment.The surface temperature to be subjected to plasma treatment should be maintained at temperatures below the which the surface is not adversely affected significantly (other than the intended increase in surface area when rough and light chemical modification is put on). A person skilled in the art can easily select the operating conditions of the plasma unit, vis-à-vis, the treated substrate to achieve an improvement in the adhesion of a film / coating superimposed on the plasma treated surface. The examination of the treated surface can be done using an atomic force microscope to determine the relative extent of the physical change in the surface. Generally, an oxygen plasma at low temperature and microwave frequency can be used for the treatment of a photochromic coating for which a radiation-cured dendritic polyester acrylate film is applied. The curable dendritic polyester acrylate film-forming composition is applied in a manner that results in a substantially homogenous cured film, the thickness of which may vary. In one contemplated embodiment, the thickness is less than 200 microns, typically less than 100 microns, for example no more than 50 microns. In another contemplated embodiment, the thickness of the film can vary from 2 to 20 microns, for example from 2 to 15 microns, more typically from 8 to 12 microns. The thickness of the film can vary between any combination of those values, including the values quoted. The term "film" is generally considered by those skilled in the coating art to be a layer with a thickness of no more than 20 mils (500 microns); however, as used in this description and in the claims, the term "film" when used with respect to radiation-cured dendritic polyester acrylate film, is defined as having a thickness, as described herein. The applied film is then exposed to UV radiation (or to an electron beam process, if UV radiation is not used), that is, the radiation in the range of 200 and 450 nm. Typically, this is achieved by passing the film (or the substrate on which the film is applied) under a commercially available UV lamp or Excimer laser on a conveyor belt moving at predetermined speeds. The radiation can contain visible and ultraviolet light in its spectrum. The radiation may be monochromatic or polychromatic, incoherent or coherent and should be sufficiently intense to initiate polymerization. Any type of UV lamp can be used, for example, mercury vapor or pulse xenon. If a photoinitiator is used, the absorbance spectra of the photoinitiator or photoinitiators must be adjusted with the spectral output of the ÜV lamp (bulb), for example a H bulb, a D bulb, a Q bulb or a V bulb, for further curing effective. The curing process is generally more effective when oxygen, for example air, is excluded from the curing process. This can be achieved by using a layer of nitrogen on the film applied during the curing process. After curing by radiation, for example UV curing, a thermal post-curing can be used to completely cure the film. Heating in an oven at 212 ° F (100 ° C) for 0.5 to 3 hours is usually adequate to cure the film thoroughly. The analysis with respect to the radiation curing of the photochromic coating is also applicable here in relation to the curing of the dendritic polyester acrylate film and accordingly this analysis is incorporated herein.

As an alternative, the dendritic polyester acrylate film can be thermally cured, although thermal curing is less desirable. For example, an azo-type or peroxy-type thermal free radical initiator may be incorporated into the film and the film cured by infrared heating or by placing the film (or the substrate containing the film) in a conventional oven, for example an oven. convection, maintained at sufficient temperatures to cure the film. Examples of such free radical initiators are described herein in relation to the photochromic coating composition based on acrylic / ethacrylic monomer, and this analysis is applicable herein. In a further contemplated embodiment, the dendritic polyester acrylate film can be cured with a combination of a thermal initiator, as described above and a photoinitiator. Non-limiting examples of photoinitiators are described herein in relation to photopolymerization of the photochromic polymeric coating.

This analysis is applicable here and is incorporated into this document. When the thermal curing of the composition comprising the dendritic polyester acrylate is used, alone or in combination with a photoinitiator, for example using radiation curing, one or more of the other reactive monomeric materials for example (meth) acrylic monomers, which are incorporated with the dendritic polyester acrylate will also be thermally curable. Rigid substrates to which the photochromic polymeric coating is applied may vary and include any rigid substrate that supports a polymeric or photochromic coating. Non-limiting examples of such rigid substrates include: paper, glass, ceramics, wood masonry, fabrics, metals and organic polymeric materials. The particular substrate used will depend on the particular application that requires both a rigid substrate and a photochromic coating. In a desired embodiment, the rigid substrate is transparent. The polymeric substrates that can be used in the preparation of photochromic articles of the present invention include organic polymeric materials and inorganic materials such as glass. As used herein, the term "glass" is defined as a polymeric substance, for example a polymeric silicate. The glass substrates can be of any type suitable for the intended purpose; although it is desirably a clear, slightly colored transparent glass, such as the well known silica type glasses particularly soda-lime-silica glass. The nature and composition of various silica glasses is well known in the art. The glass can be hardened by thermal or chemical tempering. The polymeric organic substrates that can be used to prepare the photochromic articles described herein are any of the plastics materials currently known (or later discovered) that are chemically compatible with the photochromic polymeric coating applied to the surface of the substrate. Particularly contemplated synthetic resins are contemplated which are useful as optical substrates, for example organic optical resins which are used to prepare optically transparent molds for optical applications, such as ophthalmic lenses. Non-limiting examples of organic substrates that can be used as polymeric organic substrates are polymers, ie homopolymers and copolymers prepared from the monomers and monomer mixtures described in U.S. Patent No. 5,962,617 and in U.S. Pat. No. 5,658,501 from column 15, line 28 to column 16, line 17. Said organic substrates can be thermoplastic or thermoset polymeric substrates, for example transparent substrates, more particularly optically transparent, having a refractive index which it desirably varies between 1.8 to 1.74 for example from 1.50 to 1.67. Non-limiting examples of said described monomers and polymers include: polyol (allyl carbonate) monomers, for example, allyl diglycol carbonates such as diethylene glycol bis (allyl carbonate), which monomer is sold under the trademark CR-39 in PPG Industries, Inc.; polyurea-polyurethane (polyurea urethane) polymers, which are prepared by examples by the reaction of a polyurethane prepolymer and a diamine curing agent, a composition for a polymer like this being sold under the trademark TRIVEX from PPG Industries, Inc .; carbonate monomers terminated in poly (meth) acryloyl; diethylene glycol dimethacrylate monomer; ethoxylated phenol methacrylate monomers; diisopropenyl benzene monomer; ethoxylated monomers of trimethylol propane triacrylate; ethylene glycol bismethacrylate monomers; polyethylene glycol bismethacrylate monomers; urethane acrylate monomers; poly (bisphenol A dimethacrylate ethoxylate) monomers; vinyl polyacetate, polyvinyl alcohol; poly (vinyl chloride), poly (vinylidene chloride), polyethylene, polypropylene, polyurethanes, polythiourethanes, thermoplastic polycarbonates such as the carbonate-bonded resins derived from bisphenol A and phosgene, one of said materials being marketed under the trademark LEXAN; polyesters such as the material marketed under the MYLAR trademark; poly (ethylene terephthalate); polyvinyl butyral; poly (methyl methacrylate), such as the material marketed under the trademark PLEXIGL S, and polymers prepared by reacting isocyanate or polyfunctional isocyanates and / or isothiocyanates with polyols or polyepisulfide monomers, homopolymerized or co-and / or terpolymerized with polythiols, polyisocyanates, polyisothiocyanates and optionally ethylenically unsaturated monomers or vinyl monomers containing halogenated aromatics. Copolymers of said monomers and mixtures of the described polymers and copolymers with other polymers are also contemplated for example to form interpenetrating network products. The exact chemical nature of the organic substrate is not critical to the present invention. However, the organic polymeric substrate must be chemically compatible with the photochromic polymeric coating applied to the surface of the substrate. For optical applications, the substrate must be transparent, more desirably optically transparent. The polymeric organic substrate used to prepare the photochromic articles of the present invention may have a protective coating, for example an abrasion resistant coating, on its surface. For example, commercially available thermoplastic optical polycarbonate lenses are typically marketed with an abrasion resistant coating, for example a hard coating, applied around their surface or surfaces because the surface tends to scratch, scrape or scratch easily. An example of such a lens is the Gentex polycarbonate lens (available from Gentex Optics) that is marketed with a hard coating around it applied to the polycarbonate surface. As used in this description and claims, the terms "polymeric organic substrate" (or similar terms) or "surface" of said substrate, is meant to include both the polymeric organic substrate itself or said substrate with a coating, for example a coating protector and / or primer layer, on the substrate. Therefore, when reference is made in that description or in the claims to the application of a primer coating or photochromic polymer coating to the surface of the substrate, said reference includes applying said coating to the polymeric organic substrate per se or to a coating, by example an abrasion resistant coating or primer layer on the surface of the substrate. Therefore, the term "substrate" includes substrates having a protective coating and / or primer layer on its surface. The coating can be any suitable coating (other than a photochromic coating) and is not limited to an abrasion resistant coating (hard coating) for example any protective coating, primer coating or even a coating that. provides additional functional properties to the article of which the substrate forms a part. The use of photochromic organic coatings on plastic substrates has been described, particularly plastic substrates such as thermoplastic polycarbonates. In accordance with the present invention, any organic polymeric material that can be used as a coating with the chosen organic substrate and which will function as a host material for the organic photochromic materials / compounds selected for use can be used. Normally, the organic polymeric host coating has a sufficient internal free volume for the photochromic material to function effectively, for example to change from a colorless form to a colored form that is visible to the naked eye in response to ultraviolet radiation (ÜV) and Change back to the colorless form when the ÜV radiation is removed. On the other hand, the precise chemical nature of the organic coating that is used as the host material for the photochromic material or materials is not critical.

Non-limiting examples of such organic polymeric materials include polyurethane-based coatings such as those described in U.S. Patent Nos. 6,107,395 and 6,187,444 Bl and International Patent Publication WO 01/55269; coatings based on epoxy resins such as those described in U.S. Patent No. 6,268,055 Bl; coatings based on acrylic / methacrylic monomers, such as those described in U.S. Patent No. 6,602,603, International Patent Publications WO 96/37593 and WO 97/06944, and U.S. Patent Nos. 5,621,017 and U.S. Pat. 5,776,376; aminoplasts, for example of melamine type, resins such as those described in U.S. Patent Nos. 6,506,488 Bl and 6,432,544 Bl; coatings comprising hydroxyl functional components and components with polymeric anhydride functionality, for example polyanhydride coatings, such as those described in U.S. Patent No. 6,436,525 Bl; urethane polyurea coatings, such as those described in column 2, line 27 to column 18, line 67 of U.S. Patent No. 6,531,076 B2; and coatings comprising polymers with N-alkoxymethyl (meth) acrylamide functionality, such as those described in U.S. Patent No. 6,060,001. Of particular interest are photochromic polyurethane based coatings, photochromic polyacrylic or polymethacrylic based coatings [collectively referred to as poly (meth) acrylic based coatings], photochromic aminoplast resin based coatings, photochromic polyurea urethane based coatings and coatings based on in photochromic epoxy resin. Of particular interest are optically transparent coatings based on photochromic polyurethane, polyurea urethane, epoxy and polymethacrylic for use on transparent plastic substrates, for example, optically transparent for ophthalmic applications, such as flat ophthalmic lenses and for vision correction, sunglasses and diving glasses, windows for shops and homes, transparent elements for cars and airplanes, helmets, plastic laminates, transparent films, etc. The term "transparent", as used in this description and claims in relation to a substrate, film, material or coating is intended to mean that the indicated coating, film, substrate or material, such as the plastic substrate, the non-activated photochromic coating, the radiation-cured dendritic polyester acrylate film and overlapping or superimposed coatings on the radiation-cured dendritic polyester acrylate film has a light transmission of at least 70%, typically at least 80% and more typically at least 85% By the term "optically transparent" as used in this description and in the claims, it is understood that the specified article has a light transmission that satisfies the regulatory values and accepted in the market for optical articles, for example ophthalmic articles. The polyurethanes that can be used to prepare a photochromic polyurethane coating are those produced by the reaction of an organic polyol component and an isocyanate component, as will be more fully described in column 3, line 4 to column 6, line 22 of the United States No. 6,187,444 Bl. More particularly, the polyurethanes are produced from a combination of at least one hard segment that produces organic polyol and at least one soft segment that produces organic polyol. Generally, the hard segment results from the reaction of the isocyanate and a chain extender; and the soft segment results from the reaction of the isocyanate with a polymer structural component such as a polycarbonate polyol, a polyester polyol or a polyether polyol, or mixtures of said polyols. The weight ratio of the polyols that produce the hard segment to polyols that produce the soft segment can vary from 10:90 to 90:10. The relative amounts of the components comprising the polyurethane reaction mixture can be expressed as a proportion of the available number of isocyanate groups reactive to the available number of reactive hydroxyl groups, for example, a ratio of NCO: OH groups from 0.3: 1.0 to 3.0: 1.0. The isocyanate component can be an aliphatic, aromatic, cycloaliphatic or heterocyclic isocyanate, or mixtures of said isocyanates. Typically, the isocyanate component is selected from blocked or unblocked aliphatic or cycloaliphatic isocyanates, or mixtures of said isocyanates. As further described in U.S. Patent No. 6,107,395, suitable polyurethanes as photochromic host material can be prepared from a reactive isocyanate mixture comprising (i) 40 to 85 percent by weight of one or more polyols having a nominal functionality of 2 to 4 and molecular weights of 500 to 6000 g / mol; (ii) 15 to 60 weight percent of one or more diols or triols or mixtures thereof having a functionality of 2 to 4; at 3 and molecular weights from 62 to 499, and (iii) an aliphatic polyisocyanate having a functionality of less than 3, for example 2. U.S. Patent No. 6,602,603 referred to above describes reaction mixtures for poly-host materials (meth) acrylics for photochromic materials comprising at least two difunctional (meth) acrylate monomers, which may have from more than 3 to less than 15 alkoxy units. In a described embodiment, a difunctional methacrylate has the reactive acrylate groups connected by a straight or branched chain alkylene group, which usually contains from 1 to 8 carbon atoms; while a second difunctional methacrylate has reactive acrylate groups connected by ethylene oxide, propylene oxide, butylene oxide or mixtures of said oxide groups in random or block order. The epoxy resin-based coatings described in US Pat. No. 6,268,055 Bl are those prepared by the reaction of a composition comprising an epoxy or polyepoxide resin, for example polyglycidyl ethers of aliphatic alcohols and phenols, epoxy-containing acrylic polymers. , polyglycidyl esters of polycarboxylic acids and mixtures of said epoxy-containing materials, with a curing agent, for example a polyacid comprising a half-ester formed from the reaction of an acid anhydride with an organic polyol. The amount of photochromic coating applied to at least one surface of the plastic substrate is that amount that provides a sufficient amount of organic photochromic material to produce a coating that exhibits a desired change in optical density (? OD) when the cured coating is exposed to ultraviolet radiation (UV), that is, a photochromic quantity. Typically, the change in optical density measured at 22 ° C (72 ° F) after 30 seconds of UV exposure is at least 0.05, more typically at least 0.15 and even more typically at least 0.20. The change in optical density after 15 minutes of ÜV exposure is typically at least 0.10, more typically at least 0.50, and even more typically at least 0.70. By exposing it in a different manner, the amount of active photochromic material used in the photochromic coating can vary from 0.5 to 40.0 percent by weight, based on the total weight of the monomer or monomers / resin or resins used to produce the coating . The relative amounts of photochromic material or materials used will vary and will depend in part on the relative intensities of the color of the activated form of the photochromic compound or compounds, the desired final color and the solubility or dispersibility of the photochromic material or materials in the polymeric coating. Care should be taken to avoid the use of amounts of photochromic material, which cause the crystals of the photochromic material or materials to form within the coating. Typically, the concentration of the active photochromic material or materials within the photochromic coating ranges from 1.0 to 30 percent by weight, more typically from 3 to 20 percent by weight and even more typically from 3 to 10 percent by weight (based on in the total weight of monomer or monomers / resin or resins used to produce the coating). The amount of photochromic material in the coating can vary between any combination of these values, including the values quoted. The bleach rate of the photochromic coating, presented in terms of half-life of loss of intensity T (V2), is typically not more than 500 seconds, more typically not more than 190 seconds, and even more typically not more than 115 seconds. The semi-life bleaching rate is the time interval in seconds for which the change in optical density (? OD) of the activated form of the photochromic coating occurs to reach half of the highest? OD after the withdrawal of the activating light source. The values described above for changing the optical density and bleaching rate are measured at 22 ° C (72 ° F). The photochromic coating applied to the surface of the substrate will typically have a thickness of at least 3 microns, more typically at least 5 microns, still more typically at least 10 microns, for example at least 20 or 30 microns. The applied photochromic coating will also have a thickness typically of not more than 200 microns, more usually not more than 100 microns and more usually not more than 50 microns, for example not more than 40 microns. The thickness of the photochromic coating can vary between any combination of these values, including the values quoted. For example, the photochromic coating can vary from 10 to 50 micrometers, for example from 20 to 40 micrometers. The applied photochromic coating should be more desirably free of cosmetic defects such as scratches, spots, spots, cracks, inclusions, etc. Typically, the term "coating" is considered by those skilled in the coating art to be a layer having a thickness of no more than 4 mils (approximately 100 microns). However, as used in this specification and in the claims relating to the photochromic coating, the term "coating" is defined in as having a thickness such as a thickness defined inbefore. Furtore, as used in this specification and in the claims, it is intended that the term "polymeric substrate surface" or similar terms, ie the surface to which the photochromic polymeric coating is applied, include the embodiment in which only a portion of the surface of the substrate is coated. Tfore, the photochromic coating (and the dendritic polyester acrylate film applied to the photochromic coating) can cover only a portion of a surface of the substrate, although it is typically applied to the entire surface of at least one surface of the substrate. The hardness of the photochromic coating is not critical, although after application and curing, it should desirably be hard enough to be physically / mechanically handled without causing imperfections, for example scratches on the coating. The hardness of the photochromic coating is typically less than that of the film prepared from the radiation-cured dendritic polyester acrylate composition applied to the photochromic coating, which in turn is typically softer than the abrasion-resistant coating (hard coating). applied to the dendritic polyester acrylate film. Tfore, the main coatings applied to the plastic substrate (which do not include any primer layer that can be applied to the substrate) increase the hardness in the direction of the abrasion resistant coating. The coating hardness or films can be quantified by tests known to those skilled in the art, for example Fiscmicrohardness, pencil hardness or Knoop hardness. Fiscmicrohardness of photochromic polymer coatings is typically less than 30 Newton per mm 2, more particularly less than 25, for example less than 15 such as 2 or 5 Newton per mm 2. In particular, the Fiscmicrohardness values will be in the lower portion of the ranges described in, for example 2 to 25, such as 10 to 15, for example 12 Newton per imS. The lower hardness range allows the Electrocyclic mechanism analyzed above with respect to photochromic materials occurs more effectively than at highardness values. The Fiscmicrohardness of the photochromic polymeric coatings can vary between any combination of the indicated values including the cited values. Fiscmicrohardness values can be obtained with an HCV Model H-100 Fiscscope (available from FiscTechnology, Inc.) taking 3 measurements in the central area of the test sample under 100 milliNew load conditions, 30 loading stages and pauses of 0.5 seconds between loading stages on an indentation hardness testing machine (Vickers diamond style) at a depth of 2 μm (micrometers).

Photochromic materials, for example, dyes / photochromic compounds or compositions containing said dyes / compounds, which can be used for the photochromic coating applied to the rigid substrate are inorganic photochromic compounds and / or substances containing said photochromic compounds that are commonly known to the specialists in the art (or who are discovered later). The particular photochromic material or materials, for example compound or selected compounds, are not critical, and their selection will depend on the final application and the color or shade desired for this application. When two or more photochromic compounds are used in combination, they are generally chosen to complement each other to produce a desired color or shade. The organic photochromic compounds used in the photochromic coating usually have at least one maximum absorption activated within the visible spectrum of between 300 and 1000, for example between 400 and 700 nanometers. The organic photochromic material or materials are incorporated, for example, dissolved or dispersed in the photochromic coating and color when activated, i.e. when exposed to ultraviolet radiation, the photochromic material or materials changes to the color or hue that is characteristic of the form colored of said material or materials. The inorganic photochromic material typically contains silver halide crystallites, cadmium halide and / or copper halide. Generally, the halide material is chloride and bromide. Other photochromic and inorganic materials can be prepared by the addition of europium (II) and / or cerium (III) to a mineral glass such as soda-silica glass. In one embodiment, the inorganic photochromic material or materials are added to molten glass and formed as particles that are incorporated into the coating composition that is used to form the polymeric photochromic coating. Such inorganic photochromic materials are described in Kirk Othmer Encyclopedia of Chemical Technology, 4th Edition, Volume 6, pages 322-325.

In a contemplated embodiment, the organic photochromic component of the photochromic coating comprises: (a) at least one photochromic organic compound having a maximum visible lambda of 400 to less than 550, for example of 400 to 525 nanometers; and (b) at least one photochromic organic compound having a maximum visible lambda greater than 525 or 550 nanometers, for example 525 or 550 to 700 nanometers. Non-limiting examples of photochromic compounds that can be used in the photochromic coating include benzopyrans, chomenes, for example, naphthopyrans such as naphtho [1,2-b] pyrans, and naphtho [2, lb] pyrans, spiro-9-fluorene [ 1, 2-b] pyrans, phenanthropyrans, quinopyrans and indene-naphthopyrans fused such as those described in U.S. Patent No. 5,645,767 in column 1, line 10 to column 12, line 57 and U.S. Pat. 5,658,501 column 1, line 64 to column 13, line 36. Additional non-limiting examples of photochromic compounds that may be used include oxazines such as benzoxazines, naftoxazines, and spiro (indoline) pyridobenzoxazines. Other photochromic substances contemplated for use herein are metal dithizonatos, for example mercury dithytonates which are described in for example U.S. Patent No. 3,361,706; fulgides and fulgimides, for example the 3-furyl and 3-thienyl fulgides and fulgimides which are described in U.S. Patent No. 4,931,220 in column 20, line 5 to column 21, line 38; diariletenqs, which are described in U.S. Patent Application No. 2003/0174560 from paragraphs [0025] to [0086]; and mixtures of any of the photochromic materials / compounds mentioned above. Other non-limiting examples of photochromic compounds, polymerizable photochromic compounds and complementary photochromic compounds are described in the following United States Patents: 5,166,345 in column 3, line 36 to column 14, line 3; 5,236,958 in column 1, line 45 to column 6, line 65; '5,252,742 in column 1, line 45 to column 6, line 65; 5,359,085 in column 5, line 25 to column 19, line 55; 5,488,119 in column 1, line 29 to column 7, line 65; 5,821,287 in column 3, line 5 to column 11, line 39; 6,113,814 in column 2, line 23 to column 23, line 29; 6,153,126 in column 2, line 18 to column 8, line 60; 6,296,785 in column 2, line 47 to column 31, line 5; 6,348,604 in column 3, line 26 to column 17, line 15; and 6,353,102 in column 1, line 62 to column 11, line 64. Spiro (indoline) pyrans are also described in the text Techniques in Chemistry, Volume III, "Photochro ism", Chapter 3, Glenn H. Brown, Editor, John Wiley and Sons, Inc., New York, 1971. Furthermore, it is contemplated that organic photochromic materials such as photochromic pigments and photochromic compounds encapsulated in metal oxides can be used in the photochromic coating. See, for example, the materials described in U.S. Patent Nos. 4,166,043 and 4,367,170. The photochromic coating of the present invention may contain a photochromic compound or a mixture of two or more photochromic compounds, as desired. Mixtures of photochromic compounds can be used to obtain certain activated colors such as almost neutral gray or almost neutral brown. See, for example, U.S. Patent No. 5,645,767, column 12, line 66 to column 13, line 19, which describes the parameters defining the neutral gray and brown colors. The photochromic compound or compounds described herein can be incorporated into the curable coating composition by addition to the coating composition and / or by dissolving the compound or compounds in a solvent before adding it to the curable coating composition. Alternatively, although more involved, the photochromic compound or compounds may be incorporated into the polymeric coating cured by embedding, permeation, diffusion or other transfer methods, said methods being known to those skilled in the art of dye transfer to host materials. In addition to photochromic materials, the photochromic coating (or precursor formulation) may contain additional conventional adjuvants that confer the desired properties or characteristics to the coating that are necessary for the process used to apply and cure the photochromic coating on the surface of the plastic substrate or that enhance the performance of the coating. Such adjuvants include, but are not limited to, ultraviolet light absorbers, light stabilizers such as hindered amine light stabilizers (HALS), asymmetric diaryloxalamide compounds (oxanilide), singlet oxygen inactivators, for example a nickel ion complex with an organic ligand, antioxidants, polyphenolic antioxidants, thermal stabilizers, rheology control agents, leveling agents, for example surfactants, free radical acceptors and adhesion promoting agents such as trialkoxy silane, for example silanes having an alkoxy radical of 1 to 4 carbon atoms, including α-glycidoxypropyl trimethoxy silane, α-aminopropyl trimethoxysilane 3,4-epoxy cyclohexylethyl trimethoxysilane, dimethyldiethoxysilane, aminoethyl trimethoxysilane and 3- (trimethoxysilyl) propyl methacrylate. Mixtures of said adjuvant materials that enhance the photochromic performance are contemplated. See, for example, the materials described in U.S. Patent Nos. 4,720,356, 5,391,327 and 5,770,115.

Compatible dyes (chemically and of the same color), for example dyes, can also be added to the photochromic coating formulation or applied to the plastic substrate for medical reasons or for fashionable reasons, for example to achieve a more aesthetic result. The particular dye selected may vary and will depend on the need mentioned above and the result to be achieved. In an embodiment, the dye can be selected to complement the resulting color of the activated photochromic materials used, for example to achieve a more neutral color or to absorb a particular wavelength or incident light. In another contemplated embodiment, the colorant may be selected to provide a desired shade to the substrate and / or coating when the photochromic coating is in an inactivated state. The photochromic coating composition can be applied to the surface of the plastic substrate as a polymerizable formulation and then cured (polymerizable) by methods well known to those skilled in the art including, but not limited to, photopolymerization, thermal polymerization (including infrared polymerization and other sources). of radiation). Said methods of application include the methods recognized in the art of rotation coating, curtain coating, dip coating, spray coating or by the methods used in the preparation of the superposed layers. Such methods are described in U.S. Patent No. 4,873,029. When applied as a polymerizable formulation, the photochromic coating formulation will typically also contain a catalyst or polymerization initiator. The amount of catalyst / initiator or polymerization initiators used to polymerize the polymerizable components of the photochromic coating formulation may vary and will depend on the particular initiator and the polymerizable monomers used. Typically, only this amount is needed to initiate (catalyze) and sustain the polymerization reaction, i.e. an initiating or catalytic amount. Generally, 0 to 10 weight percent, eg, 0.01 to 8 weight percent, more typically 0.1 to 5 weight percent, based on the total weight of the polymerizable monomer or monomers is used. the formulation, of at least one catalyst and / or polymerization initiator, including photoinitiators. The amount of catalyst / initiator can vary between any combination of the values indicated above, including the values quoted. The catalyst or catalysts / initiator or initiators will be selected from those materials that can be used to polymerize the particular monomer or monomers used to produce the polymeric coating chosen as the photochromic host and which will not significantly interfere with the functioning of the photochromic materials included in the coating formulation. For example, catalysts that can be used to cure polyurethane reaction mixtures can be selected from the group consisting of Lewis bases, Lewis acids and insertion catalysts described in Ullmann's Encyclopedia of Industrial Chemistry, 5th Edition, 1992, Volume A21 , p. 673 to 674. Normally the catalyst is an organotin catalyst, for example tin octylate, dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin mercaptide, dibutyl tin dimaleate, dimethyl tin diacetate, dimethyl tin dilaurate and , 4-diazabicyclo [2.2.2] octane. Mixtures of tin catalysts can be used. Other tin catalysts described in the art can also be used. Epoxy resin coating compositions typically contain a polyacid curing agent having a medium high acid functionality, ie two or more acid groups per molecule. Typically, the acid group is a carboxylic acid group. Non-limiting examples of polycarboxylic acids include dicarboxylic acids such as oxalic, malonic, succinic, tartaric, glutaric, adipic, sebacic, maleic, fumaric, phthalic, isophthalic, terephthalic, and dodecanedioic acids; tricarboxylic acids such as citric acid and tetracarboxylic acids such as 1, 2, 3, 4-butane tetracarboxylic acid. The polyanhydride coating compositions typically contain an amine compound as a curing catalyst. Non-limiting examples of amine compounds include, dimethyl cocoamine, dimethyl dodecylamine, triethylamine, tetranolamine and phenolic compounds containing at least two dialkyl amino groups. Aminoplast resins and polymeric alkoxy acrylamide coating compositions usually contain an acidic material as a catalyst. Non-limiting examples including phosphoric acid or substituted phosphoric acids such as alkyl phosphate acid and phenyl phosphate acid; and sulfonic acid or substituted sulfonic acids such as para-toluene sulfonic acid, dodecylbenzene sulfonic acid and dinonyl naphthalene sulfonic acid. Coating compositions based on acrylic / methacrylic monomers may contain thermal initiators, for example initiators that produce free radicals such as organic peroxide compounds or azobis (organonitrile) compounds, photoinitiators or mixtures of said initiators. Non-limiting examples of suitable organic peroxy compounds include peroxymonocarbonate esters, such as tert-butylperoxy isopropyl carbonate; peroxydicarbonate esters such as di (2-ethylhexyl) peroxydicarbonate di (butyl secondary), peroxydicarbonate and diisopropyl peroxydicarbonate; diacyl peroxides such as 2,4-dichlorobenzoyl peroxide, isobutyryl peroxide, decanoyl peroxide, lauroyl peroxide, propionyl peroxide, acetyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, peroxyesters such as t-pivalate. butylperoxy, t-butylperoxy octylate and t-butylperoxy isobutyrate; Methyl ethyl ketone peroxide and acetyl cyclohexane sulfonyl peroxide. Non-limiting examples of suitable azobis (organonitrile) compounds include azobis (isobutyronitrile), 2,2'-azobis (2,4-dimethylpentanenitrile), 1,1'-azobiscyclohexane carbonitrile and azobis (2,4-dimethylvaleronitrile) and mixtures of said azo thermal initiators. The desired thermal initiators are those that do not discolor the resulting coating or decompose the incorporated photochromic material within the polymerizable coating composition.

The photopolymerization can be carried out in the presence of at least one photoinitiator using ultraviolet light and / or visible light, if photoinitiators are needed. Photoinitiators that are initiators of free radicals are classified into two main groups based on their mode of action. The cleavage-type photoinitiators include, but are not limited to acetophenones, a-aminoalkylphenones, benzoin ethers, benzoyl oximes, acylphosphine oxides and bisacylphosphine oxides. Photoinitiators of the abstraction type include, but are not limited to, benzophenone, Michler's ketone, thioxanthone, anthraquinone, camphorquinone, fluorone, and ketocoumarin. Photo-initiators of the abstraction type work best in the presence of materials such as amines and other hydrogen-donor materials added to provide unstable hydrogen atoms for abstraction. Typical hydrogen donors have an active hydrogen placed in an alpha position with respect to an oxygen or nitrogen, for example alcohols, ethers and tertiary amines, or an active hydrogen atom directly attached to sulfur, for example thiols. In the absence of said added materials, photoinitiating can still occur by abstraction of hydrogen from monomers, oligomers or other components of the system. Non-limiting examples of photopolymerization initiators that may be used include benzyl, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzophenol, acetophenone, benzophenone, 4,4'-dichlorobenzophenone, 4, '-bis (N, N' -dimethylamino) benzophenone, diethoxyacetophenone, fluorones, for example, the H-Nu series of initiators available from Spectra Group Limited, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-isopropylthixanthone, a- aminoalkylphenone, for example, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, acylphosphine oxides, such as 2,6-dimethylbenzoyl diphenyl phosphine oxide, 2,4,6-trimethylbenzoyl oxide diphenyl phosphine, 2,6-dichlorobenzoyl diphenyl phosphine oxide, and 2,6-dimethoxybenzoyl diphenyl phosphine oxide; bisacylphosphine oxides, such as bis (2,6-di-etioxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,6-dimethylbenzoyl) -2,4,4-trimethylpentylphosphine oxide, (2,, 6-trimethylbenzoyl) -2, 4, 4-trimethylpentyl phosphine, and bis (2,6-dichlorobenzoyl) -2,4,4-trimethylpentyl phosphine oxide; phenyl-4-octyloxyphenyliodonium hexafluoroantimonate, dodecyldiphenyliodonium hexafluoroantimonate, (4- (2-tetradecanol) oxyphenyl) -iodonium hexafluoroantimonate and mixtures of said photopolymerization initiators. The radiation source used for photopolymerization is selected from those sources that emit ultraviolet light and / or visible light. The radiation source can be a mercury lamp, a mercury lamp doped with Fel3 and / or Gal3, a germicidal lamp, a xenon lamp, a tungsten lamp, a metal halide lamp or a combination of said lamps. Typically, the absorbance spectra of the photoinitiator or photoinitiators are adjusted with the spectral output of the light source bulb, for example a bulb H, a bulb D, a bulb Q and / or a bulb V, for a greater efficiency of cured. The exposure time of the curable coating to the light source will vary depending on the wavelength and intensity of the light source, the photoinitiator and the thickness of the coating. Generally, the exposure time will be sufficient to substantially cure the coating or produce a coating that is sufficiently cured to permit physical handling followed by a post-thermal cure. The photochromic coating can also be cured using an electron beam process that does not require the presence of a thermal photoinitiator. Solvents may also be present in the coating formulation to dissolve and / or disperse the components of the coating formulation. Typically, an amount of solvent solvation is used, for example, an amount that is sufficient to solubilize / disperse the solid components in the coating formulation. Usually, 10 to 80 percent solvent material is used, based on the total weight of the coating formulation. Solvents include, but are not limited to, benzene, toluene, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethanol, tetrahydrofurfuryl alcohol, propyl alcohol, propylene carbonate, N-methyl pyrrolidinone, N-vinyl pyrrolidinone, N-acetyl pyrrolidinone, N-hydroxymethyl pyrrolidinone, N-butyl pyrrolidinone, N-ethyl pyrrolidinone, N- (N-octyl) pyrrolidinone, N- (N-dodecyl) pyrrolidinone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methyl cyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, methanol, amyl propionate, propionate methyl, propylene glycol methyl ether, diethylene glycol monobutyl ether, di-ethyl sulfoxide, dimethylformamide, ethylene glycol, mono- and di-alkyl ethers of ethylene glycol and their derivatives, which are marketed as industrial solvent CELLOSOLVE and mixtures of said solvents. In a further contemplated embodiment, the photochromic polymeric coating can be applied as an aqueous coating, for example an aqueous polymer dispersion, such as a latex with or without the presence of an organic solvent. This type of system is a two-phase system comprising an aqueous phase and an organic phase, which is dispersed in the aqueous phase. The use of aqueous coatings is well known in the art. See for example U.S. Patent 5,728,769 which relates to aqueous urethane resins and coatings prepared from said resins and the patents referred to in the 769 patent. After applying the photochromic coating formulation to the surface of the plastic substrate, it is cured (polymerized) by exposure to ultraviolet radiation or electron beam, or thermally cured. The specific curing conditions used will depend on the plastic substrate, the polymerizable components in the formulation and the type of catalyst / initiator used or in the case of electron beam radiation, the intensity of the electron beam. The term curing may involve heating from room temperature to temperatures below which the plastic substrate is not damaged due to such heating. Temperatures of up to 200 ° C have been reported. Such curing conditions are well known in the art. For example, a typical thermal curing cycle involves heating the formulation from room temperature (22 ° C) to 85 to 125 ° C for a period of 2 to 20 minutes. The time required for curing by ultraviolet or electron beam radiation is generally shorter than thermal curing, for example from 5 seconds to 5 minutes and will depend on the intensity (power) of the radiation. When the thermal cure or UV / electron beam conditions produce a physically manageable coating, even if it is not fully cured, an additional post-thermal curing step may also be employed to fully cure the photochromic coating. Before applying the photochromic coating to the surface of the plastic substrate, the surface of the substrate is often cleaned and treated to provide a clean surface and a surface that will enhance the adhesion of the photochromic coating to the substrate. Effective cleaning and commonly used treatments include, but are not limited to, ultrasonic washing with an aqueous soap / detergent solution, cleaning with an aqueous mixture of organic solvent, for example 50:50 mixture of isopropane: water or ethanol: water, UV treatment, activated gas treatment, for example plasma treatment at low temperature or corona discharge as described above, and chemical treatment which results in hydroxylation of the surface of the substrate, for example surface attack with an aqueous hydroxide solution of alkali metal, for example sodium or potassium hydroxide, said solution also containing a fluorosurfactant. Generally, the alkali metal hydroxide solution is a dilute aqueous solution, for example 5 to 40 weight percent, more typically 10 to 15 weight percent such as 12 weight percent, of alkali metal hydroxide . See, for example, U.S. Patent No. 3,971,872, column 3, line 13 to 25; U.S. Patent No. 4,904,525, column 6, lines 10 to 48 and U.S. Patent No. 5,104,692, column 13, lines 10 to 59, describing surface treatments of polymeric organic materials. In some cases, a primer coating is applied to the plastic surface substrate before application of the photochromic coating. The primer coating is interposed between the organic substrate and the photochromic polymeric coating and serves as a barrier coating to prevent interaction of the components comprising the photochromic polymeric coating with the substrate and vice versa and / or as an adhesive layer to promote adhesion of the photochromic coating to the plastic substrate. The primer can be applied to the plastic substrate by any method used to apply the photochromic coating, for example spray coating, rotation, dispersion, curtain, roller or dipping; and can be applied to a clean and untreated or cleaned and treated surface for example chemically treated of the substrate. The primer coatings are well known to those skilled in the art. The selection of an appropriate primer coating will depend on the plastic substrate used and the particular photochromic coating, for example the primer coating must be chemically and physically compatible with the surface of the plastic substrate and the photochromic coating, while providing the desired functional benefits for the primer coating for example barrier and adhesive properties. The primer coating may be one or more monomolecular layers of thickness which may vary from 0.1 to 10 micrometers, more usually from 0.1 to 2 or 3 micrometers in thickness. The thickness of the primer can vary between any combination of the values mentioned above, including the values quoted. One contemplated embodiment of a suitable primer coating comprises an organofunctional silane such as methacryloxypropyl trimethoxysilane, a catalyst of a material that generates acid during exposure to actinic radiation, for example onium salts, and an organic solvent such as diglyme or isopropyl alcohol as described in U.S. Patent No. 6,150,430. A further example of a primer coating is disclosed in U.S. Patent No. 6,025,026, which discloses a composition that is substantially free of organosiloxanes and that comprises organic anhydrides having at least one ethylenic bond and an isocyanate-containing material. . In a further contemplated embodiment, an abrasion resistant coating overlays, for example, overlays on the dendritic polyester acrylate film. In such an embodiment, the post-thermal cure of the dendritic polyester acrylate film can be postponed until after the application of the abrasion-resistant coating if there is no significant physical handling of the product coated with the dendritic polyester acrylate film until after the application of the abrasion resistant coating. If such extensive handling is necessary, it is suggested that the post-thermal curing of the dendritic polyester acrylate film be carried out before the application of the abrasion-resistant coating. The cured dendritic polyester acrylate film should be transparent, more particularly, optically transparent when used for optical applications, for example ophthalmic and which does not significantly interfere with the optical properties of the photochromic coated substrate. For example, the dendritic polyester acrylate film should allow a sufficient amount of appropriate UV radiation to pass through it to activate the photochromic materials incorporated in the photochromic polymeric coating added to the substrate. The terms "transparent" and "optically transparent" have been defined above in this description. The surface of the cured dendritic polyester acrylate film or films is desirably harder than the photochromic coating to which it is applied, and is usually softer than the abrasion resistant coating that is usually applied to the dendritic polyester acrylate film. As described, the cured dendritic polyester acrylate film must adhere well to the photochromic coating and must be compatible with the abrasion resistant coatings that are prepared with organosilanes. Furthermore, it is desirable, though not essential, that the cured dendritic polyester film be resistant to treatment, eg, removed, with aqueous inorganic caustic solutions, for example, diluted aqueous solutions of sodium or potassium hydroxide, as described later in this document. The radiation-cured dendritic polyester acrylate film should desirably adhere firmly to the photochromic coating applied to the plastic substrate. Adhesion can be determined by the conventional test recognized in the adhesion technique of crosshatch tape release, and by an adhesion test of cross hatch strip release in boiling water, which is a more rigorous test. The first is often referred to as the primary (1 °) test or dry test; while the latter is often referred to as secondary (2 o) or wet test. In the primary test, a cutting tool composed of eleven blades spaced approximately 1 mm apart (tip to tip) and 0.65 mm thick is used to make a first longitudinal cut on the sample followed by a second and third cuts, which are made at 90 degrees towards and transversally the first cut. The second and third cuts are separated from each other to provide separate areas of cross hatching. A piece of Scotch 3M protective tape of one inch (2.54 cm) wide and 2 to 2 1/2 inches in length (5 to 6.3 cm) is applied in the direction of the first cut and pressed for eliminate any bubble. The tape separates after the surface with a sudden, fast, uniform and continuous movement. The procedure is repeated with a new piece of tape. A small piece of tape (1-1 / 2 inches, 3.8 cm) is applied to each of the cross hatching areas produced by the second and third cuts in a 90 degree direction relative to the direction of the first tape. , and these pieces of tape are also separated from the surface with a sudden, rapid, uniform and continuous movement. If it is found that 30 percent or less of the squares of the grid produced by the cutting tool have been separated from the substrate (photochromic coating) that is, at least 70 percent of the grids remain intact, the coating is considered which passes the adhesion test. More particularly, it is desirable that no more than 20, particularly no more than 10 squares, even more particularly no more than 5 squares, for example 1 square of every 100 squares of the grid are separated from the substrate. According to the present invention, the radiation-cured dendritic polyester acrylate film must pass the cross-hatch strip release adhesion test which is considered to have adhered to the photochromic coating. In other words, if the radiation-cured dendritic polyester acrylate film passes the cross-hatch strip release test it is referred to in that document as having been coherently added (or cohesively added) or attached to the layer, for example the photochromic coating, to which it is added. A more severe addition test is the secondary or wet addition test, which can finally be performed to evaluate the adhesion of the radiation-cured dendritic polyester acrylate film to the photochromic coating. This additional test, that is, the cross hatch adhesion test in boiling water involves placing the test sample, for example, a lens, which has been scored with a cross hatch, as described above, in boiling deionized water during 30 minutes. After the test sample has cooled to room temperature, the cross hatch strip release adhesion test is performed again as described above. The same step / failure requirements that were described for the cross hatch adhesion test for this modified boiling water test are used. The radiation-cured dendritic polyester acrylate film, in a contemplated treatment-resistant embodiment, for example, removed by aqueous inorganic caustic solutions, for example with respect to dilute solutions of alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide solutions . The film is considered to be resistant to removal by such solutions if the thickness of the film is reduced no more than 0.5 microns after exposure to 12.5% aqueous potassium hydroxide at 140 ° F (60 ° C) for four minutes. Desirably, the thickness of the film is not reduced more than 0.5 microns after two exposures, more desirably after three exposures, to the aqueous potassium hydroxide solution. It is also desirable that the radiation-cured dendritic polyester acrylate film be compatible with abrasion-resistant coatings (hard coating), particularly abrasion resistant coatings comprising organosilane material or materials that are used to protect plastic surfaces from abrasion, scratching, etc. Silane-containing abrasion-resistant coatings are often referred to as hard coatings or silane-based hard coatings, are well known in the art and are commercially available from various manufacturers such as SDC Coatings, Inc. and PPG Industries, Inc. Reference is made in column 5, lines 1-45 of U.S. Patent No. 4,756,973 and in column 1, lines 58 to column 2, line 8 and column 3, line 52 to column 5, line 50 of U.S. Patent 5,462,806, the disclosures of which describe hard organosilane coatings. Reference is also made to U.S. Patents Nos. 4,731,264, 5,134,191, 5,231,156 and International Patent Publication WO 94/20581 for descriptions of hard coatings of organosilanes. Although a described physical feature of the radiation-curable dendritic polyester acrylate film is that it is compatible with hard organosilane coatings, other coatings that provide abrasion and scratch resistance, such as polyfunctional acrylic hard coatings, can be used as an abrasion-resistant coating. hard coatings based on melamine, hard coatings based on urethane, coatings based on alkyd, hard coatings based on silica sol, or other hard inorganic / organic hybrid coatings. A person skilled in the art can easily determine whether the dendritic polyester acrylate film is compatible with hard organosilane coatings by applying a hard coating of organosilane to the dendritic polyester acrylate film and determining the compatibility of the dendritic polyester acrylate film with the hard coating by means of the cross-hatch strip release adhesion test, which is carried out on the hard coating.

Another method for determining the compatibility of the dendritic polyester acrylate film with the hard coating is the absence of icrofissures in the hard coating after it has been applied to the dendritic polyester acrylate film and cured. Microcracking is the presence of fractures in the hard coating. These fractures are sometimes easily noticeable by observation; however, fractures can be very fine and observable by magnification under a bright light. The light source can be composed of a high-intensity white light arc of a 75-watt xenon bulb, with the light projected vertically down through the hard coating. By using the phrase "compatible with an abrasion resistant coating of organosilane (hard coating)" it is meant that the dendritic polyester acrylate film is capable of having a hard coating of organosilane deposited on its surface and that the hard coating of organosilane adheres to the dendritic polyester acrylate film under ordinary handling / wear conditions, determined by the cross hatch strip release adhesion test or the absence of microcracks in the hard coating. Naturally, the organosilane hard coating can be removed by treatment with concentrated aqueous caustic soda or severe mechanical abrasion. In addition, the term abrasion resistant coating containing organosilane (or another term of similar meaning) means that the abrasion resistant coating is prepared from a composition comprising at least one organosilane.

It is contemplated, if necessary, that a primer coating may be applied to the dendritic polyester acrylate film before applying the abrasion resistant coating thereon. Such primer coatings are known in the art. The selection of an appropriate primer coating will depend on the particular dendritic polyester acrylate film and the abrasion resistant coating used, i.e., the primer coating must be chemically and physically compatible (non-reactive) with the surfaces on which it is applied. supports The primer coating may be one or more monomolecular layers in thickness and may vary from 0.1 to 10 micrometers, for example from 0.1 to 2 or 3 micrometers in thickness. Said primer coatings are analyzed in this document in relation to the photochromic coating and this analysis is also applicable in this document. In one embodiment, the hard coating can be prepared from a composition comprising from 35 to 95 weight percent, as calculated solids, of at least one organosilane monomer represented by the following empirical formula VIII: R1SiW3 VIII wherein R1 is glycidoxy alkyl (Ci-C20), desirably glycidoxyi (C? -C10) alkyl and more desirably glycidoxy alkyl (C? -C4); W is hydrogen, halogen, hydroxy, C 1 -C 5 alkoxy, C 1 -C 5 alkoxy (C 1 -C 5) alkoxy, C 1 -C 4 acyloxy, phenoxy, C 1 -C 3 alkyl phenoxy or C 1 -C 3 alkoxy phenoxy, said halogen being bromine, chlorine or fluoro. Typically, W is hydrogen, halogen, hydroxy, C 1 -C 3 alkoxy, C 1 -C 3 alkoxy (C 1 -C 3) alkoxy, C 2 -C 2 acyloxy, phenoxy, C 2 -C 2 alkyl phenoxy or C 2 -C 2 phenoxy alkoxy and Halogen is chlorine or fluoro. More typically, W is hydroxy, C 1 -C 3 alkoxy, C 1 -C 3 alkoxy (C 1 -C 3) alkoxy, C 1 -C 2 acyloxy, phenoxy, C 1 -C 2 alkyl, phenoxy, or C 1 -C 2 alkoxy phenoxy. The percentage by weight, as calculated solids, of monomer or silane monomers represented by empirical formula VIII in the hard coating composition is typically 40 to 90, more typically 45 to 85 and even more typically 50 to 70 percent. in weigh. The calculated weight percentage of the solids is determined as the percentage of silanol that is formed theoretically during hydrolysis of the orthosilicate. Non-limiting examples of silane monomers represented by formula VIII include: glycidoxymethyltriethoxysilane, Glicidoximetiltrimetoxisilano, alpha-glycidoxyethyltrimethoxysilane, alpha-glycidoxyethyltriethoxysilane, alpha-glycidoxypropyltrimethoxysilane, alpha-glycidoxypropyltriethoxysilane, alpha-glycidoxypropyltrimethoxysilane, alpha-glycidoxypropyltriethoxysilane, beta-glycidoxyethyltrimethoxysilane, beta-glycidoxyethyltriethoxysilane, beta-glycidoxypropyltrimethoxysilane, beta-glycidoxypropyltriethoxysilane, beta-glycidoxybutyltrimethoxysilane, beta-glicidoxibuti1trietoxisilaño , gamma-glycidoxypropyltrimethoxysilane. gamma-glycidoxypropyltriethoxysilane, gamma-glicidoxipropiltripropoxisilano, gamma-glycidoxypropyltributoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropyltriphenoxysilane, gamma-glycidoxybutyltrimethoxysilane, gamma-glicidoxibutiltrietoxisilano, delta-glycidoxybutyltrimethoxysilane, delta-glicidoxibutiltrietoxisilano, hydrolysates of said silane monomers and mixtures of such silane monomers and hydrolysates thereof. The hard coating composition of the embodiments described above may additionally include from 5 to 65 weight percent, as calculated solids, of: (a) silane monomers represented by empirical formula IX; (b) metal alkoxides represented by the empirical formula X; or (c) a mixture thereof in a weight ratio of (a): (b) from 1: 100 to 100: 1.

Typically, the hard coating composition includes to 60 weight percent of calculated solids, more typically 15 to 55 and even more typically 30 to 50 weight percent solids calculated from the materials mentioned above (a), (b) or (c). The hard coating composition may include at least one silane monomer represented by the following empirical formula IX: R b (R) cSÍZ 4 _ (b + c) IX wherein R 2 may be C 1 -C 20 alkyl, C 1 haloalkyl C2o / C2-C20 alkenyl, C2-C20 haloalkenyl, phenyl, phenylalkyl (C? -C20), alkyl (C? -C2o) phenyl, phenylalkenyl (C2-C20), alkenyl (C2-C2o) phenyl, morpholino, amino-alkyl (C? -C2u), amino-alkenyl (C2-C2o), mercapto alkyl (C? -C2o), mercapto alkenyl (C2-C2o), cyano (C? -C2o) alkyl, cyano (C2-C20) alkenyl, acryloxy, methacryloxy or halogen. The halo or halogen can be bromine, chlorine, or fluoro. Typically, R2 is a C? -C10 alkyl, C? -C10 haloalkyl, C2-C? 0 alkenyl, phenyl, phenylalkyl (C? -C10), C1-C10 alkylphenyl, morpholino, amino (C1-C10) alkyl, amino alkenyl (C2-C? 0), mercapto (C1-C10) alkyl, mercapto alkenyl (C2-C? o), cyano (C? -C10) alkyl, cyano (C2-C? o) alkenyl or halogen and the halo or halogen is chlorine or fluoro. In formula IX, R3 can be C? -C20 alkylene, C2-C2o alkenylene, phenylene, C? -C2 alkylene phenylene, amino (C? -C20) alkylene, (C2-C20) alkenylene amino; Z can be hydrogen, halogen, hydroxy, C?-C alco alkoxy, C alcoC alco alkoxy (C?-C5) alkoxy, C?-C 4 acyloxy, phenoxy, C C-C3-phenoxy alkyl or C?-C3-phenoxy alkoxy, halo or halogen is bromine, chlorine or fluoro; each of b and c is an integer from 0 to 2 and; and the sum of b and c is an integer from 0 to 3. Typically, R3 is C? -C10 alkylene, C2-C10 alkenylene, phenylene, C? -C? alkylene or phenylene, C? -C? amino, alkylene, amino C2-C? alkenylene? Z, is hydrogen, halogen, hydroxy, C? -C3 alkoxy, C? -C3 alkoxy C? -C3 alkoxy, C? -C2 acyloxy, phenoxy, C? -C2 alkyl phenoxy or C? alkoxy? -C2 phenoxy and the halo or halogen is chloro or fluoro. Non-limiting examples of silane monomers represented by general formula IX include methyltrimethoxysilane, methyl triethoxysilane, metiItrimetoxietoxisilano, methyltri-acetoxysilane, methyltripropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, gamma-methacryloxypropyltrimethoxysilane and, gamma- aminopropyltri ethoxysilane, gamma-aminopropyltriethoxysilane, gamma - ercaptopropyltrimethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, dimethyldiethoxysilane, gamma-chloropropylmethyldimethoxysilane, gamma-chloropropyl-methyldiethoxysilane, tetramethylorthosilicate, tetraethylorthosilicate, hydrolysates of said silane monomers and mixtures of said silane monomers and hydrolysates thereof. The hard coating compositions may additionally include at least one compound represented by the empirical formula X: M (T) q X wherein M is a metal selected from aluminum, antimony, tantalum, titanium or zirconium; T is alkoxy C? -C? O and q is an integer equivalent to the valence of M. Normally M is chosen from aluminum, titanium or zirconium and T is Ci-C5 alkoxy for example propoxy. The hard coating composition may also include 0 to 20 weight percent, based on the total weight of the metal oxide composition chosen from silicon dioxide (silica), aluminum oxide (alumina), antimony oxide, tin, titanium oxide, zirconium oxide or mixtures of said metal oxides. The metal oxide may be in the form of a sol. As used herein, the term "sol" means and includes a colloidal dispersion of finely divided solid inorganic metal oxide particles in an aqueous or organic liquid. The average size of said particles can vary from 1 to 200 nanometers, typically from 2 to 100 nanometers, and more typically from 5 to 50 nanometers.

Said metal oxide sols can be prepared by hydrolyzing a metal salt precursor for a sufficient time to form the desired particle size or said sols can be purchased commercially. Examples of commercially available metal oxide sols that can be used in the hard coating composition include NALCO® colloidal sols (available from NALCO Chemical Co.).zED , colloidal soils REMASOL® (available from Remet Corp.) and colloidal sols LUDOX® (available from EI I. du Pont de Nemours Co., Inc.). The stable metal oxide, acid and alkali sols are commercially available as aqueous dispersions. Usually the metal oxide is silica or alumina supplied in the form of a colloidal silica stabiliwith acid, colloidal alumina stabiliwith acid for example NALCO® 8676, or a silica sol coated with alumina stabiliwith acid for example NALCO® 1056. The sols of Metal oxide can also be obtained as dispersions in organic liquids, for example ethanol, isopropyl alcohol, ethylene glycol and 2-propoxyethanol. The hard coating composition also contains a catalytic amount of a water soluble acid catalyst. A catalytic amount is that amount which is sufficient to cause the polycondensation of the silane monomer or monomers. Typically, the catalytic amount of acid catalyst will vary from 0.01 to 10 weight percent, based on the total weight of the hard coating composition. The water-soluble acid catalyst can be a carboxylic acid or an inorganic acid. Examples of suitable catalysts include acetic acid, formic acid, glutaric acid, maleic acid, nitric acid, sulfuric acid and hydrochloric acid. The organic solvents present in the hard coating composition can be added or formed in situ by the hydrolysis of the silane monomer or monomers. Useful organic solvents are those that dissolve or disperse the solid components of the coating composition. The minimum amount of solvent present in the coating composition is an amount of solvation, that is, an amount that is sufficient to solubilize or disperse the solid components in the coating composition. For example, the amount of solvent present may vary from 20 to 90 weight percent based on the weight based on the total weight of the coating composition and depends in part on the amount of silane monomer present in the coating composition. Examples of 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-methyl pyrrolidinone, N-vinyl pyrrolidinone, N -acetyl pyrrolidinone, N-hydroxymethyl pyrrolidinone, N-butyl pyrrolidinone, N-ethyl pyrrolidinone, N- (N-octyl) pyrrolidinone, N- (N-dodecyl) pyrrolidinone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methyl cyclohexanone , ethyl acetate, butyl acetate, tetrahydrofuran, methanol, amyl propionate, methyl propionate, diethylene glycol onobutilus, dimethyl sulfoxide, dimethyl formamide, ethylene glycol, mono- and di-alkyl ethers of ethylene glycol and their derivatives, which are marketed with the commercial name of industrial solvents. CELLOSOLVE, methyl propylene glycol methyl ether and methyl ether propylene glycol acetate, sold under the trade names DOWANOL® PM and PMA respectively, and mixtures of these solvents. A leveling amount of surfactant or nonionic surfactants may be present as a component in the hard coating composition. A leveling amount is that amount which is sufficient to allow the coating to uniformly disperse or level the hard coating composition on the surface of the dendritic polyester acrylate film to which it is applied. Typically, the nonionic surfactant is a liquid under the conditions of use and is used in amounts of about 0.05 to about 1.0 weight percent based on the amount of the silane monomer or monomers. Suitable nonionic surfactants are described in the Kirk Othmer Encyclopedia of Chemical Technology, 3rd Edition, Volume 22, pages 360 to 377. Other potential nonionic surfactants include the surfactants described in U.S. Patent No. 5,580,819, column 7, line 32 to column 8, line 46. Non-limiting examples of nonionic surfactants that can be used in the hard coating composition include ethoxylated alkyl phenols such as surfactants IGEPAL® DM or octyl-phenoxy polyethoxyethanol, which is marketed as TRITON® X-100, an acetylenic diol such as 2, 4, 7, 9-tetramethyl-5-decino-4,7-diol, which is marketed as SURFYNOL® 104, ethoxylated acetylenic diols, such as SURFYNOL series of surfactants ® 400, fluoro-surfactants such as the series of FLUORAD® fluorochemical surfactants, and finished non-ionic surfactants, such as finished benzyl octyl phenol ethoxylates, which is marketed as TRITON® CF87, the alkyl ethoxylates terminated with propylene oxide, which are available as the series of surfactants PLURAFAC® 'RA, octylphenoxyhexadecylethoxy benzyl ether, copolymer of dimethylpolysiloxane modified with polyether in solvent, sold as additive BYK® -306 by Byk Chemie and mixtures of said cited surfactants. The water is also present in the hard coating composition in an amount sufficient to form hydrolysates of the silane monomer or monomers. The water present in the optional metal oxide sol can supply the necessary amount of water. If not, additional water may be added to the coating composition to provide the required additional amount necessary to hydrolyze the silane monomer or monomers. The abrasion resistant coating (hard coating) can be applied to the dendritic polyester acrylate film using the same application techniques described with respect to the photochromic coating and the dendritic polyester acrylate film, for example spin coating. The abrasion resistant film can be applied at a thickness of 0.5 to 10 micrometers. Before applying the hard coating, for example, the hard coating of organosilane, to the acrylate film of the dendritic polyester, the dendritic polyester acrylate film can be treated to enhance its receptivity to and adhesion of the hard coating. Said treatments, for example plasma treatments, which are as described above with respect to the pretreatment of the photochromic coating can be used before the application of the dendritic polyester acrylate film. In a further embodiment of the present invention, additional coatings, such as anti-reflective coatings, may be applied to the hard coating layer. Examples of antireflective coatings are described in U.S. Patent No. 6,175,450 and in International Patent Publication WO 00/33111. The present invention is described more particularly in the following examples which are intended to be illustrative only, since numerous modifications and variations thereof will be apparent to those skilled in the art. In the examples, the percentages are presented as a percentage by weight, unless otherwise specified. Materials, such as monomers, catalysts, initiators, etc., which are identified in one example by a lowercase letter in parentheses and used in other examples, are identified in the following examples with the same lowercase letter. EXAMPLE 1 In the following example, PDQ flat lenses coated with polycarbonate obtained from Gentex Optics were used. The test lenses were treated with an oxygen plasma for one minute using a Plasmatech machine at a power setting of 100 watts while oxygen was iduced at a rate of 100 ml / min in a vacuum chamber of the Plasmatech machine. The lenses were then rinsed with deionized water and air dried. A photochromic polyurethane coating composition was applied to the plasma treated lenses by spin coating and thermally cured. The components of the polyurethane composition and their amounts are shown in Table 1. The components of the polyurethane composition were mixed for 30 minutes at 60 ° C., followed by 30 minutes of mixing at room temperature before applying it to the lenses. The photochromic polyurethane coating was approximately 20 micrometers thick.

TABLE 1 Formulation Component / Quantity, Grams Desmodur PL 3175A (a) 2,6 Vestanat B 1358A (b) 7,6 PC 1122 (c) 8,0 polyol HCS 6234 (d) 1,9 Stabilizer ÜV Tinuvin 144 0,36 (e) 0.53 A-187 (f) 5.6 N-methyl pyrrolidinone 0.58 Photochromic material (g) 0.05 Surfactant L-5340 (h) 0.16 Dibutyltin dilaurate (a) Hexamethylene diisocyanate blocked with methyl ethyl ketoxime (Bayer) (b) Isophorone diisocyanate trimer blocked with methyl ethyl ketoxime (CreaNova, Inc.) (c) Polyhexane carbonate diol (Stahl) (d) Polyacrylate polyol (Composition D in Example 1 of the document US 6,187,444 Bl) (e) Amine light stabilizer with impediments (Ciba-Geigy) (f) Trimethoxysilane coupling agents? glycidoxypropyl (OSi) (g) A mixture of photochromic naphthopyran materials in the proportions designed to give the coating a gray stain when activated by UV radiation. (h) Surfactant (Niax) Two coating preparations were prepared using 15 grams of each of dendritic polyester acrylate PRO-5249. The dendritic polyester acrylate PRO-5249 is presented by its supplier as a 50/50 mixture of neopentyl glycol-2-propoxylated diacrylate and a dendritic polyester acrylate in which approximately 13 of the 16 terminal hydroxy groups have been acrylated. The first coating preparation used pure PRO 5249 without a photoinitiator; while the second coating preparation contained 0.038 grams (0.25% by weight) of BAPO photoinitiator [bis (2,4,6-trimethylbenzoyl) phenyl phosphine oxide]. The photochromic polyurethane coating on the test lenses was treated by plasma discharge using the Plasmatech machine using the same conditions used to treat the uncoated flat lenses. The dendritic polyester acrylate coating preparations were applied to the test lenses by spin coating to give a wet film weight of about 0.06 grams (about 10 microns thick). The coatings were cured in a nitrogen atmosphere with ÜV light from a D bulb. Subsequently, 4 lenses (2 with the BAPO photoinitiator and 2 without photoinitiator) were treated with plasma using the Plasmatech machine using the same conditions used to treat flat lenses. uncoated and then coated with the hard coating with a hard siloxane-based coating (HI-GARD 1035 available from PPG Industries, Inc.) The thickness of the hard coating was approximately 2 microns. All samples were hardened again in a convection oven for 3 hours at 100 ° C. The test lenses were tested for adhesion using the cross-hatch strip release secondary adhesion test and for hard coating compatibility by observing the level of microcracks after hard coating cure. It was found that all test lenses coated with dendritic polyester acrylate coatings (with and without photoinitiator) but without a hard coating had 100% adhesion in both primary crosshatch tape release adhesion tests (dry ) and secondary (wet). It was found that hard coated lenses (without photoinitiator) had 100% adhesion (primary crosshatch) and 90% adhesion (secondary crosshatch) respectively. It was found that hard coated lenses (with photoinitiator) have 90% adhesion (primary cross streak) and 70% adhesion (secondary cross stitch) respectively. It was observed that all hard coatings did not have microcracks, indicating that the hard coating was compatible with the dendritic polyester acrylate coating. The test lenses coated with dendritic polyester acrylate film were transparent and had a light transmission of 86%. The test lenses, coated with dendritic polyester acrylate film, were exposed to UV light and observed for reversible color change. EXAMPLE 2 The procedures of Example 1 were followed using polycarbonate PDQ flat lenses obtained from Gentex Optics, except that the dendritic polyester coating solutions were prepared using 5 grams of dendritic polyester acrylate PRO 5249 and 0.0125 grams (0.25% by weight) of BAPO photoinitiator. Additionally, a coating solution further contained 0.25 grams of β-glycidoxypropyltrimethoxysilane (A-187). The test lenses were treated with a plasma discharge, as described in Example 1, and coated with a photochromic polyurethane coating of the type described in Example 1, and the dendritic polyester acrylate coating solutions were applied. by spin coating the photochromic polyurethane coatings and cured in the manner described in Example 1. Two lenses were treated with plasma, as described in Example 1, and hard coated with a hard coating based on siloxane. All the lenses were hardened again in a convection oven for 3 hours at 100 ° C. The tests for adhesion and hardcoat compatibility were performed as described in Example 1. It was found that all lenses containing the silane additive A-187 (with and without hard coating) had 100% adhesion (crosshatching) primary and secondary cross hatch). In addition, the hard coatings did not show microcracks after curing. It was found that lenses without the A-187 silane additive and without a hard coating had 100% adhesion (primary cross-hatched and secondary cross-hatched), whereas it was found that the hard-coated lenses had an adhesion of 100%. % (primary cross streak) and 40% adhesion (secondary cross stitch). These lenses also showed no microcracks in the hard coating.

Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that said details be observed as limitations of the scope of the invention except as it is included in the appended claims.

Claims (56)

1. A photochromic article comprising: (a) a rigid substrate (b) a photochromic organic polymeric coating added to at least a portion of at least one surface of said substrate, said polymeric coating comprising a photochromic amount of at least one photochromic material, and (c) a transparent dendritic polyester acrylate film superposed on said photochromic polymeric coating.

2. The photochromic article of claim 1 wherein the dendritic polyester acrylate film is prepared from a liquid composition prepared by acrylating a macromolecule of dendritic polyester and an organic alcohol having a molecular weight of less than 2000.

3. The photochromic article of claim 1 wherein the dendritic polyester acrylate film is prepared from a composition comprising dendritic polyester acrylate and at least one other acrylic material curable by radiation or thermally.

4. The photochromic article of claim 3 wherein at least one other acrylic material curable by radiation or thermally is a monomeric (meth) acrylic material selected from monoacrylates and polyacrylates.

5. The photochromic article of claim 4 wherein the polyacrylate is a diacrylate, triacrylate or mixture of diacrylates and triacrylates.

6. The photochromic article of claim 4 wherein the weight ratio of the dendritic polyester acrylate to the other monomeric (meth) acrylic material or materials curable by radiation or thermally ranges from 90:10 to 10:90.

7. The photochromic article of claim 6 wherein the weight ratio of the dendritic polyester acrylate to the other monomeric (meth) acrylic material or materials curable by radiation or thermally varies from 70:30 to 30:70.

8. The photochromic article of claim 6 wherein the weight ratio of the dendritic polyester acrylate to the other monomeric (meth) acrylic material or curable by radiation or thermally varies from 60:40 to 40:60.

9. The photochromic article of claim 4 wherein the dendritic polyester acrylate film is prepared from a composition further comprising at least one other monomeric material curable by radiation containing polymerizable group or groups, other than acrylic functional groups, being present said at least one other monomeric material curable by radiation in amounts of up to 40 weight percent of said composition.

10. The photochromic article of claim 1 further comprising an abrasion resistant coating superimposed on the surface of the dendritic polyester acrylate film.

11. The photochromic article of claim 10 wherein the abrasion resistant coating comprises an organosilane based coating.

12. The photochromic article of claim 10 further comprising an antireflective coating attached to the surface of the abrasion resistant film.

13. The photochromic article of claim 3 wherein at least one photoinitiator is present in photoinitiating amounts in the composition comprising the dendritic polyester acrylate and the at least one other acrylic material curable by radiation.

14. The photochromic article of claim 4 wherein at least one photoinitiator is present in photoinitiating amounts in the composition comprising the dendritic polyester acrylate.

15. The photochromic article of claim 14 wherein at least one photoinitiator is present in an amount of 0.1 to 10 weight percent.

16. The photochromic article of claim 14 wherein at least one photoinitiator is present in an amount of 0.5 to 6% by weight.

17. The photochromic article of claim 1 wherein the thickness of the dendritic polyester acrylate film varies from 2 to 20 microns.

18. The photochromic article of claim 1 wherein the acrylate film of dendritic polyester is compatible with abrasion resistant coatings containing organosilane.

19. The photochromic article of claim 18 wherein the photochromic organic polymeric coating is softer than the dendritic polyester acrylate film.

20. The photochromic article of claim 1 wherein the transparent rigid substrate is an organic polymeric substrate chosen from thermoset or thermoplastic materials having a refractive index of 1.48 to 1.74.

21. The photochromic article of claim 20 wherein the polymeric substrate is a substrate chosen from thermoset substrates prepared from polymerizable compositions comprising monomer or monomers of allyl diglycol carbonate, substrates prepared from thermoplastic polycarbonates, substrates prepared from polyurea urethanes or substrates prepared from compositions comprising the reaction product of isocyanate or polyfunctional isocyanates and / or isothiocyanate or isothiocyanates with polythiol or monomer or polyepisulfide monomers.

22. The photochromic article of claim 21 wherein the allyl diglycol carbonate is diethylene glycol bis (allyl carbonate).

23. The photochromic article of claim 1 wherein the photochromic organic polymeric coating is chosen among photochromic coatings based on polyurethane, photochromic coatings based on polyurea urethane, photochromic coatings based on poly (meth) acrylic, photochromic coatings based on aminoplast resin or coatings photochromic based on epoxy resin.

24. The photochromic article of claim 1 wherein the photochromic material is a photochromic material selected from photochromic spirooxazines, benzopyrans, naphthopyrans, fulgida, metal dithizonatos, diaryletenes or mixtures of said photochromic materials.

25. The photochromic article of claim 24 wherein the photochromic naphthopyran is selected from naphtho [1,2-b] pyrans, naphtho [2, lb] pyrans, spiro-9-fluorene [1,2-b] pyrans, phenanthropyrans, quinopyrans or naphthopyrans condensed with indene and spirooxazine is selected from naphthoxazines or spiro (indoline) pyridobenzoxazines.

26. A photochromic article comprising: (a) a transparent rigid organic polymeric substrate, (b) a photochromic organic polymeric coating added to at least a portion of at least one surface of said polymeric substrate, said polymeric coating comprising a photochromic amount of at least one a photochromic material, and (c) a transparent dendritic polyester acrylate film consistently added to said photochromic polymeric coating.

27. The photochromic article of claim 26 wherein the polymeric substrate is chosen from thermoset or thermoplastic materials having a refractive index of 1.48 to 1.74.

28. The photochromic article of claim 26 wherein the polymeric substrate is a substrate chosen from thermoset substrates prepared from polymerizable compositions comprising monomer or monomers of allyl diglycol carbonate, substrates prepared from thermoplastic polycarbonates, substrates prepared from polyurea urethanes or substrates prepared from compositions comprising the isocyanate reaction product or polyfunctional isocyanates and / or isothiocyanate or polythiol isothiocyanates or polyepisulfide monomer or monomers.

29. The photochromic article of claim 28 wherein the dendritic polyester acrylate film is prepared from a liquid composition prepared by acrylating a dendritic polyester macromolecule and an organic alcohol having a molecular weight of less than 2000,

30. The photochromic article of claim 28 wherein the dendritic polyester acrylate film is prepared from a composition comprising dendritic polyester acrylate and at least one other radiation curable acrylic material and said at least one other acrylic radiation curable material is a methacrylic monomeric material selected from monoacrylates, polyacrylates and mixtures of said acrylic materials.

31. The photochromic article of claim 30 wherein the dendritic polyester acrylate film is prepared from a composition comprising dendritic polyester acrylate and neopentyl glycol-2-propoxylated diacrylate.

32. The photochromic article of claim 30 wherein at least one photoinitiator is present in photoinitiating amounts in the composition comprising the dendritic polyester acrylate.

33. The photochromic article of claim 26 further comprising an abrasion resistant coating attached to the surface of the dendritic polyester acrylate film.

34. The photochromic article of claim 33 wherein the abrasion resistant coating comprises an organosilane based coating.

35. The photochromic article of claim 33 further comprising an antireflective coating attached to the surface of the abrasion resistant film.

36. A photochromic article comprising: (a) a transparent organic polymeric substrate selected from thermoset substrates prepared from polymerizable compositions comprising monomer or monomers of allyl diglycol carbonate, substrates prepared from thermoplastic polycarbonates, substrates prepared from polyurea urethanes or substrates prepared from compositions comprising the isocyanate reaction product or polyfunctional isocyanates and / or isothiocyanates with polythiols or polyepisulfide monomer or monomers, said substrate having a refractive index of 1.48 to 1.74, (b) a transparent photochromic organic polymeric coating added to at least one surface of said polymeric substrate, said polymeric coating comprising a photochromic amount of at least one organic photochromic material chosen among spirooxazines, benzopyrans, naphthopyrans, fulgida, metal dithizonatos, diaryletene s or mixtures of said photochromic materials, said photochromic polymeric coating having a thickness of 5 to 200 microns, and (c) a transparent dendritic polyester acrylate film cured by radiation added in a coherent manner to said photochromic polymeric coating.

37. The photochromic article of claim 36 wherein the photochromic coating is chosen among photochromic coatings based on polyurethane, photochromic coatings based on polyurethane urethane, photochromic coatings based on polymethacrylic, photochromic coatings based on aminoplast resin or photochromic coatings based on epoxy resin and It has a thickness of 10 to 50 micrometers.

38. The photochromic article of claim 36 further comprising an abrasion resistant coating attached to the surface of the dendritic polyester acrylate film.

39. The photochromic article of claim 38 wherein the abrasion resistant coating comprises an organosilane based coating.

40. The photochromic article of claim 38 further comprising an anti-reflective coating attached to the surface of the abrasion-resistant coating.

41. The photochromic article of claim 36 wherein the polymeric substrate is a substrate comprising a thermoplastic polycarbonate.

42. The photochromic article of claim 36 wherein the dendritic polyester acrylate film is prepared from a liquid composition prepared by acrylating a macromolecule of dendritic polyester and an aliphatic alcohol having a molecular weight of from 60 to 1000.

43. The photochromic article of claim 41 wherein the dendritic polyester acrylate film is prepared from a composition comprising dendritic polyester acrylate and at least one other radiation curable acrylic material -

44. The photochromic article of claim 43 in that at least the other acrylic radiation curable material is a monomeric (meth) acrylic material or materials chosen from monoacrylates or polyacrylates.

45. The photochromic article of claim 44 wherein the polyacrylate material or materials is a diacrylate, triacrylate or mixtures of diacrylate or diacrylates and triacrylate or triacrylate.

46. The photochromic article of claim 44 wherein the weight ratio of. Dendritic polyester acrylate to other material or curable (meth) acrylate acrylics by radiation varies from 70:30 to 30:70.

47. The photochromic article of claim 43 wherein at least one photoinitiator is present in photoinitiating amounts in the composition comprising the dendritic polyester acrylate and the at least one other acrylic radiation curable material.

48. The photochromic article of claim 47 wherein the at least one photoinitiator is present in amounts of 0.5 to 6 weight percent.

49. The photochromic article of claim 36, wherein the article is an ophthalmic article.

50. The photochromic article of claim 49 wherein the ophthalmic article is a lens.

51. The photochromic article of claim 41 wherein the photochromic coating is chosen among photochromic coatings based on polyurethane, photochromic coatings based on polyurethane urethane, photochromic coatings based on poly (meth) acrylic, photochromic coatings based on aminoplast resin or photochromic coatings based on in epoxy resin and has a thickness of 10 to 50 microns and the dendritic polyester acrylate film is prepared from a composition comprising dendritic polyester acrylate and at least one (meth) acrylic material curable by radiation.

52. The photochromic article of claim 51 wherein at least one photoinitiator is present in amounts of 0.1 to 10 weight percent in the composition comprising the dendritic polyester acrylate and the at least one (meth) acrylic material curable by radiation.

53. The photochromic article of claim 52 wherein the article is an ophthalmic article.

54. The photochromic article of claim 53 wherein the ophthalmic article is a lens.

55. The photochromic article of claim 54 further comprising an abrasion resistant coating attached to the surface of the dendritic polyester acrylate film.

56. The photochromic article of claim 55 further comprising an antireflective coating attached to the surface of the abrasion resistant coating.