Abstract: Described are novel photochromic 8-substituted fluoranthenopyran compounds having certain substituents at the 5 position of the pyran ring. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: The present invention has for subjects, novel benzopyran derivatives, substituted in position 2 with an adamantyl group as well as the compositions and (co)polymer matrices containing such derivatives. Said derivatives possess interesting photochromic properties.

Abstract: A microcapsulated pigment contains, as reaction media one or more specific aliphatic acid alcohol esters obtained from monohydric aliphatic alcohols having odd numbers of carbon atoms and aliphatic carboxylic acids, these reaction media in a homogeneous compatible state with chromatic components are occluded in microcapsules to obtain characteristics of thermochromism with a hysteresis range (segment HG) from 8.degree. C. to 30.degree. C.

Abstract: A process for producing a photochromic cured product by allowing an unpurified, impurities-containing polyfunctional (meth)acrylate monomer such as unpurified polyalkylene glycol dimethacrylate and a photochromic spirooxazine compound to contain a compound having at least one epoxy group in the molecule such as glycidyl methacrylate and then polymerizing the resulting composition. The process can provide a spirooxazine-based photochromic cured product which hardy undergoes initial coloring and is superior in initial color-developing performance.

Abstract: An effect coating material and an effect coating, especially for vehicle bodies, containing interference pigments, in which the interference pigments are composed of three-dimensionally crosslinked, liquid-crystalline, main-chain polymers, which include main-chain mesogens having an at least approximately chiral nematic arrangement, and which are formed from at least one esterified cellulose ether.

Abstract: This application discloses two-coat and three-coat automotive finishes, articles coated by an automotive finish and a process for their preparation wherein polychromism is achieved in the finish by incorporating an opaque, light interference pigment into the topcoat or a midcoat. The invention further relates to a coating composition which contains an opaque interference pigment at a pigment to binder ratio of less than 7/100.

Abstract: Described are novel photochromic indeno-fused naphthopyran compounds having certain substituents at the 2-position of the pyran ring and an alkoxy group at the number 6 carbon atom. Certain other substituents may also optionally be present at the number 5, 7, 8, 9, 10, 11, 12 or 13 carbon atoms of the compounds. These compounds may be represented by the following graphic formula: ##STR1## Also described are certain novel indeno-fused naphthols which are used to make the novel naphthopyran compounds. Further described are polymeric organic host materials that contain or that are coated with the novel naphthopyran compounds, or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds.

Abstract: Benzopyran compounds represented by the formulas: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, and R.sub.10 are selected from hydrogen, a stable organic radical, a heterocyclic group, halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound.

Abstract: A coloring layer composition for a chromatic device of the present invention contains an oxide such as tungsten oxide or niobium oxide and so on as a solute, water and an organic solvent such as propanol. In the step of forming a reduction coloring layer, a film is formed by using a peroxotungstic acid solution containing 100 parts by weight of WO.sub.3.aNb.sub.2 O.sub.5.bH.sub.2 O.sub.2 .andgate.cH.sub.2 O (wherein a, b and c are each a positive number) as a solute, 20 to 120 parts by weight of water and 80 to 800 parts by weight of n-propanol as an organic solvent. At this time, a dip coating method is used, and the vertical pulling-up speed is less than 15 cm/min. The present invention can effectively prevent unevenness and separation of the reduction coloring layer.

Abstract: The present invention relates to new methods of impregnating plastic substrates with photochromic additives. By impregnating the plastic substrate in multiple impregnation steps under varying conditions, the concentration profile of two or more photochromic additive within the plastic substrate can be independently controlled. Methods are also provided for the distribution of a photochromic additive in a high boiling solvent and for increasing the glass transition temperature of a partially cured polymeric resin.

Abstract: A photochromic article that includes a host material and a photochromic amount of a naphthopyran compound, the naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1 ', R.sub.2 ', R.sub.3 ', R.sub.4 ', R.sub.5 ', R.sub.6 ', R.sub.7 ', R.sub.8 ', R.sub.9 ', R.sub.10 ', R.sub.1 ", R.sub.2 ", R.sub.3 ", R.sub.4 ", R.sub.5 ", R.sub.6 ", R.sub.7 ", R.sub.8 ", R.sub.9 ", and R.sub.10 " are each selected from the following group: a stable organic radical, a heterocyclic group, halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound.

Abstract: A spiro (indolino) oxazine compound of general formula (I) ##STR1## wherein R.sub.1 represents a group of the formula --NR.sub.2 R.sub.3 wherein each of R.sub.2 and R.sub.3, which may be the same or different, independently represents an alkyl group, or a carbocyclic group, preferably aryl, or a heterocyclic group, or R.sub.2 and R.sub.3 taken together with the nitrogen atom to which they are attached represent a heterocyclic ring having one or more heteroatoms and which may optionally carry at least one substituent selected from alkyl, aryl or heteroaryl groups;--X-- is selected from --O--, --S--, --Se--, --NH-- or --NR-- wherein R represents an alkyl group, andring A is a carbocyclic or heterocyclic ring which can be optionally substituted with a group of formula R.sub.8 as defined above, or may optionally have a carbocyclic or heterocyclic ring fused thereto; and wherein R.sub.4 -R.sub.8 are as defined in the specification.

Abstract: Described are novel 7-methylidene-5-oxo-furo fused naphthopyran compounds having certain substituents at the 2 position of the pyran ring. Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: Describes polymerizable organic compositions of from about 30 to 95 weight percent of a first monomer component which is an alkoxylated diol, e.g., alkoxylated bisphenol, having acrylate or methacrylate groups, i.e., dimethacrylate of bisphenol A having an average of 1 to 4 ethoxy units, and from about 5 to 70 weight percent of a second monomer component which is an alkoxylated diol, e.g., alkoxylated bisphenol, having acrylate or methacrylate groups, i.e., dimethacrylate of bisphenol A having 25 to 70 ethoxy units. Optionally there may also be present from about 0 to 65 weight percent of at least one monomer component which is selected from: (i) a monoethylenically unsaturated monomer that is polymerizable by free radical initiation; (ii) a bis?(meth)acryloyl-terminated!polyethylene glycol monomer; and (iii) a monomer having at least three terminal ethylenically-unsaturated groups. Substantially completely cured polymerizates prepared from such compositions may be used to prepare photochromic articles, e.g.

Abstract: Described are novel photochromic spiro(indoline) fluoranthenoxazine compounds having certain substituents on the 1 and 3 positions of the indoline portion of the compounds and which may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: A photochromic compound which is initially colored less, exhibits excellent durability and features high color density and high color fading rate, and a photochromic material thereof. The photochromic compound basically has two aromatic heterocyclic groups or an aromatic heterocyclic group and a naphthyl group at the third position, and has a benzene ring that is condensed at the f-th position.

Abstract: Described are novel pentahydrophenanthro?9,10-b!pyrans and tetrahydrocyclopenta?c!-naphtho?1,2-b!pyrans. Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: Present invention provides ionic spiropyran compounds having a C10-C22 alkyl group or groups at the 1'- and/or 8-positions of 3',3'-dimethyl-6-nitrospiro?2H-1-benzopyran-2',2'-indoline! and a composite material made by conjugating the said ionic spiropyrans with clay mineral, the said composite material being capable of forming a transparent thin film which is photo-interconvertible between the said spiropyrans and the corresponding merocyanines.

Abstract: A photochromic curable composition obtained by adding (E) an .alpha.-methylstyrene dimer and (F) a photochromic compound to polymerizable monomers comprising (A) a compound having at least one epoxy group in the molecule, such as glycidyl methacrylate or the like, (B) a polypropylene glycol di(meth)acrylate monomer, (C) a polyethylene glycol di(meth)acrylate monomer and (D) a (meth)acrylate monomer and/or a styryl monomer. This composition is superior in moldability when cured and gives a cured product of excellent durability in photochromism.

Abstract: Describes a composition of a carrier, e.g., organic solvent or polymeric host material, photochromic naphthopyran material, and a stabilizer system comprising (a) polyphenolic antioxidant material, (b) ultraviolet light absorber and (c) hindered amine light stabilizer for said photochromic naphthopyran material. The stabilizer system is selected and used in amounts sufficient to provide at least a 30% reduction in % photopic fatigue of the naphthopyran material. The weight ratio of photochromic naphthopyran to the stabilizer system is from 2.5:1 to 1.5:1. The stabilizer system can comprise 5 to 50 weight percent of the antioxidant material, 5 to 50 weight percent of the ultraviolet light absorbent, and 10 to 90 weight percent of the hindered amine light stabilizer.

Abstract: The invention relates to organic photochromic materials consisting of a polymer matrix of optical quality and of at least one dye that imparts photochromic properties to the matrix, the dye being selected from spirooxazines, spiropyrans and chromenes. The polymer constituting the matrix is a copolymer of 30-95 wt % ethoxylated bisphenol A dimethacrylate and 5-70 wt % of a polyurethane oligomer having terminal di- or triacrylic or di- or trimethacrylic functionality. Such photochromic materials are most suitable for the production of ophthalmic and sun protection lenses.

Abstract: A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.5, R.sub.6, R.sub.8, R.sub.9, and R.sub.10 are each selected from hydrogen, a first stable organic radical, an organic heterocyclic group, halogen, a first nitrogen-substituted group, and a first nitrogen-substituted ring compound; A and B are each selected from hydrogen, substituted phenyl, and substituted naphthyl, provided that at least one of A or B is substituted phenyl or substituted naphthyl; and any substituent of any substituted phenyl or substituted naphthyl at A or B is selected from hydrogen, a second stable organic radical, an organic heterocyclic group, halogen, a second nitrogen-substituted group, and a second nitrogen-substituted ring compound, provided that at least one substituent of any substituted phenyl or substituted naphthyl at either A or B is phenyl, naphthyl, or furyl.

Abstract: Described are novel compositions of a carrier and at least two photochromic naphthopyran compounds, selected on the basis of specific criteria, that when exposed to solar ultraviolet radiation, exhibit neutral colors of gray or brown contained within the a* and b* ranges of +10 to -10 in the CIELAB color system. Also described are carriers, i.e., organic solvents and organic polymeric host materials, such as optically clear articles, e.g., ophthalmic lenses or other plastic transparencies that contain or that are coated with the naphthopyran compounds.

Abstract: The invention relates to photochromic compounds of general formula: ##STR1## wherein R.sup.a, R.sup.b and R.sup.c is denote hydrogen; alkyl; aryl; OR, SR, COR or COOR, in which R denotes hydrogen, alkyl or aryl, amino of formula NR.sub.1 R.sub.2 in which R.sub.1 and R.sub.2 denote hydrogen, alkyl, cycloalkyl or an aryl; a halogen atom; a mono- or polyhaloalkyl group; or an NO.sub.2, CN or SCN group; n and m denote integers from 1 to 5; p is equal to 1 or 2; and H is a 5-members aromatic heterocycle containing one or more heteroatoms selected from nitrogen, oxygen and sulfur, these heterocyclic nuclei being eventually substituted by one or more alkyl, alkoxy, amino, aryl or aralkyl groups or condensed with a phenyl nucleus, a substituted phenyl nucleus or a 6-members cycloaliphatic nucleus and to their use in ophtalmic optics.

Abstract: Described are novel reversible photochromic naphthopyran compounds, examples of which are 3H-naphtho?2,1-b!pyrans having an acyl or aroyl oxy-bearing substituent at the number 6 carbon atom and certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 7, 8, 9 or 10 carbon atom of the naphthopyran. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds, are also described.

Abstract: A description follows of photochromatic and thermochromatic compounds, belonging to the group of spiro-indoline-oxazines, and their application in polymeric materials.

Abstract: Described are novel photochromic heterocyclic fused indenonaphthopyran compounds having a substituted or unsubstituted heterocyclic ring fused to the g, h, i, n, o or p side of the indenonaphthopyran. These compounds may be represented by either of the following graphic formulae: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: Organic ophthalmic articles are photochromic and have high indices of refraction.

Abstract: Photochromic compounds with a 3H-naphthopyran structure having at least one pyrene moiety in the 3-position, a method for preparing such compounds, and the use of such compounds for producing photochromic articles from an organic synthetic material.

Abstract: A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, and R.sub.10 are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, a halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound and wherein A is a substituted divalent aromatic radical that includes substituents selected from the group consisting essentially of hydrogen and the stable organic radical.

Abstract: Described herein are photochromic compounds or a structural isomer of the photochromic compound, the photochromic compounds represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.4, R.sub.5, R.sub.6, R.sub.8, A, B, C, and D are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, halogen, a nitrogen-substituted radical, and a nitrogen-substituted ring radical.

Abstract: The present invention provides for light fatigue resistant photochromic compositions including a unique combination of hindered aminoether light stabilizer ("HAELS") compounds to extend the usable lifetime of naphthopyran photochromic compositions and articles. Additionally, light stabilizer compounds and hydroxyphenyl benzotriazole UV absorbers have a synergistic effect in extending the usable lifetime of photochromic compositions and articles. Specifically, certain tertiary and secondary amine HALS compounds in combination with hydroxyphenyl benzotriazole UV absorbers extend the usable lifetime of spiro-indolino-oxazine photochromic compositions and articles. Similarly, aminoether HAELS compounds in combination with hydroxyphenyl benzotriazole UV absorbers further extend the usable lifetime of the naphthopyran photochromic compositions and articles.

Abstract: Described are novel photochromic heterocyclic fused indenonaphthopyran compounds having a substituted or unsubstituted heterocyclic ring fused to the g, h, i, n, o or p side of the indenonaphthopyran. These compounds may be represented by either of the following graphic formulae: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds.

Abstract: A photochromic composition comprising (a) 100 parts by weight of a di(meth)acrylate compound represented by the formula (I): ##STR1## wherein R.sup.1 s each independently represent hydrogen or methyl, R.sup.2 s and R.sup.3 s each independently represent alkylene having 1 to 4 carbon atoms, X represents halogen other than fluorine, Y represents oxygen or sulfur, and m is an integer of 0 to 4, and (b) 0.01 to 5 parts by weight of a photochromic compound. The photochromic composition is excellent in heat resistance, mechanical strength, adhesion to a hard coat layer and moldability, and the photochromic properties thereof is highly resistant to light. By the use of the photochromic composition, a thin and light-weight photochromic lens or the like can be obtained.

Abstract: Described are novel reversible photochromic diaryl-3H-naphtho?2,1-b!pyran compounds having a substituted or unsubstituted, five or six member heterocyclic ring fused to the g, i, or l side of the naphthopyran. The heterocyclic ring contains an oxygen or nitrogen atom and is attached to the number 5, 6, 7, 8, 9, or 10 carbon atom of the naphtho portion of the naphthopyran. Also described are organic host materials containing such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline)oxazine-type compounds, are also described.

Abstract: A photochromic article comprising a host material and a photochromic amount of a photochromic compound or a structural isomer of the photochromic compound, the photochromic compound represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.4, R.sub.5, R.sub.6, R.sub.8, A, B, C, and D are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, halogen, a nitrogen-substituted radical, and a nitrogen-substituted ring radical.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho-portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b] pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho-portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the number 5 carbon atom of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring. Certain substituents may also be present at the number 6, 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds fused on the naphtho-portion of the naphthopyran ring with an indeno group or certain heterocyclic substituents. Certain substituents are also present at the 2 and 5 positions and sometimes at the 6 position of the naphthopyran ring. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: Described are novel reversible photochromic 2H-naphtho[1,2-b]pyran compounds, examples of which are compounds having certain substituents at the 5 and 6-positions of the naphtho portion of the naphthopyran and at the 2-position of the pyran ring, e.g., 2,2-bis(4-methoxy phenyl)-5-methoxycarbonyl-6-morpholino-2H-naphtho[1,2-b]pyran. Certain substituents may also be present at the number 7, 8, 9 or 10 carbon atoms of the naphtho portion of the naphthopyran. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Abstract: A photochromic compound, in particular, for tinting optical elements made of a plastic material has reduced mobility in plastic material. The photochromic compound is a photochromic 2H-pyran and is distinguished by the aromatic residues being chemically rigidly attached in the 2-position to a spiropyran.

Abstract: Described are novel photochromic indeno-fused naphthopyran compounds, examples of which are naphthopyran compounds having a substituted or unsubstituted indeno group, the 2,1 positions of which are fused to the f side of the naphtho portion of the naphthopyran, and certain substituents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 6, 7, 8, 9, 10, 11, 12, or 13 carbon atoms of the compounds. These compounds may be represented by the following graphic formula: ##STR1## Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds, are also described.

Abstract: A spiro-naphtho-oxaine compound having a specific substituent providing red color development which has been unknown in the past, and photosensitive materials containing the compound. Since the compound is superior in fatigue resistance and has a sufficient red color developing density, it is used in plastic articles, optical filters, recording materials, textiles, decoration materials, and toys, which change in color by light irradiation to develop a magenta color.

Abstract: Described are novel reversible photochromic 3H-naphtho[2,1-b]pyran compounds, of the following graphic formula: ##STR1## wherein R.sub.1 is hydrogen or alkyl, R.sub.2 is hydrogen or preferably a carboalkoxy group and R.sub.3 is hydrogen or preferably an alkyl group, provided that either R.sub.1 or R.sub.2 is hydrogen, and B and B' are the aryl groups phenyl or naphthyl, a heterocyclic aromatic group or together form a spiro adamantylene group. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(oxazine) type compounds, are also described.

Abstract: The invention relates to ophthalmic lenses comprising a transparent organic polymer material and photochromic compounds of general formula ##STR1## wherein R.sup.a, R.sup.b and R.sup.c are hydrogen; alkyl; aryl; OR, SR, COR or COOR, where R denotes hydrogen, alkyl or aryl, amino of formula NR.sub.1 R.sub.2 where R.sub.1 and R.sub.2 denote hydrogen, alkyl, cycloalkyl or an aryl; a halogen atom; a mono- or polyhaloalkyl group; or an NO.sub.2, CN or SCN group; n and m denote integers from 1 to 5; p is equal to 1 or 2; and H is an aromatic heterocycle having the general formula: ##STR2## wherein: X, Y and Z represent independently of each other, a CR.sub.8 radical or a nitrogen atom, and one or two of X, Y and Z is a nitrogen atom and R.sub.8 is selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 alkyl and phenyl; and R.sub.4 is selected from the group consisting of hydrogen, C.sub.1 -C.sub.6 alkyl and phenyl.

Abstract: A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, and R.sub.10 are each selected from the group consisting essentially of hydrogen, a stable organic radical, a heterocyclic group, a halogen, a nitrogen-substituted group, and a nitrogen-substituted ring compound and wherein A is a substituted divalent aromatic radical that includes substituents selected from the group consisting essentially of hydrogen and the stable organic radical.

Abstract: The present invention is a photochromic color rendering regulatory composition and cosmetics characterized in comprising of an inorgamic compound having photochromic property. Photochromic inorganic compounds colors the composition and cosmetics suitably according to the change in light intensity.Therefore, composition and cosmetics of the present invention can regulate appropriate the tendency in which the color of objects looks whiter when the light intensity is strong and it looks blacker when it is weak, and can always provide constant color rendering.

Abstract: A naphthopyran compound of general formula (I) ##STR1## wherein R.sub.1 represents a group of the formula --NR.sub.2 R.sub.3 wherein each of R.sub.2 and R.sub.3, which may be the same or different, independently represents an alkyl group, or a carbocyclic or heterocyclic group, or R.sub.2 and R.sub.3 taken together with the nitrogen atom to which they are attached represent a heterocyclic ring having one or more hetero atoms and which may optionally carry at least one substituent selected from alkyl, aryl, or heteroaryl groups; each of R.sub.4 and R.sub.5, which may be the same or different, independently represents an alkyl, alkenyl, carbocyclic or heterocyclic group, or R.sub.4 and R.sub.5 taken together with the carbon atom to which they are attached form a carboxylcyclic ring or a heterocyclic ring; and R.sub.6 represents a hydrogen atom or a substituent selected from alkyl, alkoxy, aryl, aryloxy, heteroaryl, halogen, a group of formula R.sub.

Abstract: A photochromic composition which can be polymerized and cured upon irradiation with active energy rays such as ultraviolet rays to exhibit favorable photochromic property. The photochromic composition comprises 100 parts by weight of a radical polymerizable monomer, 0.001 to 0.2 parts by weight of a photochromic compound, and 0.01 to 1 part by weight of a photo polymerization 1.0 initiator. A photochromic cured product is obtained by irradiating the photochromic composition with the light which contains ultraviolet rays.