Displaying color change

A cathodochromic sodalite defined by the formula Na.sub.3 Al.sub.3 Si.sub.3 O.sub.12.NaX (X = Cl, Br or J) comprising at least one of the elements tin, lead and germanium in a quantity of between 0.05 and 2 atom % calculated with respect to silicon. The addition of the said elements results in an improvement...     

Silver-free photochromic glasses capable of reversibly changing from the clear nonpolarizing state to the darkened polarizing state are provided by heating a photochromic alkali boroaluminosilicate base glass containing copper and/or cadmium halides to a working temperature and elongating the glass to...     

This invention relates to protonated compounds of the formula: ##SPC1## Wherein A is a radical selected from ##SPC2## X represents the atoms necessary to complete a ring-closing moiety selected from phthalide and naphthalide; and Z is an anion derived from a protic acid. These compounds are useful as...     

Photochromic glasses having index of refraction values (n.sub.D) in the range from 1.52-1.54, compositions comprising, in weight percent, about 49-60% SiO.sub.2, 2-9% Al.sub.2 O.sub.3, 15-18% B.sub.2 O.sub.3, 6-12% Na.sub.2 O, 9-18% ZrO.sub.2, 0.5-0.9% Ag, 0.5-0.8% Cl, 0.010-0.030% CuO, 0.5-1% PbO, and...     

An ultraviolet light reflective coating is disclosed which exhibits high reflectance to ultraviolet light having wavelengths down to about 2,000 Angstrom units. The coating composition comprises a dispersion of barium sulphate in an aqueous solution of a water-soluble inorganic binder selected from the...     

A fast-acting photochromic filter--i.e. a filter whose optical density in the visible light range of 4000 to 7500 angstroms is increased when subject to radiation shorter than 6000 angstroms--which is room temperature stable, that is from at least about 20.degree. to 80.degree.C., consists of (1) a solid...     

Inorganic photochromic crystalline particles which are particularly useful in ophthalmic quality plastic host materials are formed for instance utilizing a silver halide crystal whose dimensions lie generally in the range between 30 Angstroms and 10,000 Angstroms. The surface of the silver halide crystal...     

Photochromic plastic materials are disclosed which comprise a polymeric matrix containing a multiplicity of activated silver halide particles less than 1000 Angstroms in size. The matrix may contain a retained amount of plasticizer which optimizes the desirable photochromic properties and may be sealed...     

Tungsten hexacarbonyl acts as a photochromic agent and an infrared absorber when incorporated in liquid allyl glycol carbonates, such as allyl diglycol carbonate, and polymerizates thereof. Photochromic, infrared-absorbing optical and ophthalmic lenses containing tungsten derived from tungsten hexacarbonyl...     

Copper, cadmium, silver and halogen-containing glass compositions suitable for the production of photochromic glass articles comprising these constituents in a separated, particulate photochromic phase are described. The glasses exhibit a characteristic copper-cadmium halide absorption inflection in...     

A phototropic glass containing P.sub.2 O.sub.5 as the principal component and, as agents imparting phototropy, silver and halogen in non-crystalline form.

A method for producing photochromic plastic materials is disclosed which is characterized by forming a transparent polymeric shape from a mixed polymer consisting of a polyester resin made by esterification of an unsaturated polybasic organic acid with a polyhydric alcohol, and a polar vinyl monomer,...     

In an electro-optic display which utilizes the electrochromism phenomenon of a transition metal oxide, an organic solvent for an electrolyte in contact with the transition metal oxide comprises at least one member selected from the group consisting of ketones represented by the chemical formula of C.sub.n...     

A composition is described comprising at least two co-crystallized acetylenic compounds, of different chemical structures, each containing at least one --C.tbd.C--C.tbd.C-- group and substituents selected from the group consisting of sulfonate, urethane and alcohol radicals, at least one of the compounds...     

Photochromic compounds of the formula ##STR1## wherein one of R.sub.1 and R.sub.2 is halogen or lower alkoxy, and the other is hydrogen, and R.sub.3 and R.sub.4 are hydrogen, lower alkyl, lower alkoxy, or halogen and their use in lenses are disclosed.

A composition is described comprising at least two co-crystallized acetylenic compounds, of different chemical structures, each containing at least one --C.tbd.C-C.tbd.C-- group and substituents selected from the group consisting of sulfonate, urethane and alcohol radicals, at least one of the compounds...     

Photochromic compounds of the formula ##STR1## wherein one of R.sub.1 and R.sub.2 is halogen or lower alkoxy, and the other is hydrogen, R.sub.3 and R.sub.4 are hydrogen, lower alkyl, lower alkoxy, or halogen and R.sub.5 is an alkyl of 2 to 10 carbons, and their use in lenses are disclosed.

Organic photochromic materials comprising a photochromic dye and a resinous material can be stabilized with a protective coating which will protect them from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful...     

The organic photochromic composition of this invention comprises spiro [indoline-2,3'-[3H]-naphth [2,1-b] [1,4] oxazine] (SO) dye and an unconventional ultraviolet stabilizer. The ultraviolet stabilizer improves the light fatigue resistance of the SO dye and will not hinder the photocolorability of the...     

Multiphase heterogeneous compositions containing polymeric material and pyrilium dye are illuminated by coherent optical light to generate second harmonic radiation. The compositions comprise a continuous phase of the polymeric material having therein a discontinuous phase comprising the pyrilium dye...     

The organic photochromic composition of this invention comprises trifluoromethyl substituted spiro (indoline-2,3'-(3H) napth-(2,1-b)(1,4)oxazine) (SO) dyes. This new class of (SO) photochromic compounds has a more neutral color when subjected to ultraviolet light irradiation. When used with a photochromic...     

A thermochromic composition comprising (1) an electron-donating chromogenic material, (2) a 1,2,3-triazole compound, (3) a weakly basic, sparingly soluble azomethine or carboxylic acid primary amine salt, and (4) an alcohol, amide or ester serving as a solvent.

An organic photochromic composition comprising spiro [indoline-2,3'-[3H]-naphth [2,1-b] [1,4] oxazine] dye (spirooxazine dye) and unconventional ultraviolet stabilizers. The ultraviolet stabilizers improve the light fatigue resistance of the spirooxazine (S.O.) dye and will not hinder the photocolorability...     

An activatable time-temperature indicator consists of an oxygen-sensitive reaction product of a triarylmethane dye and a decolorant that is coated on a substrate and covered by an oxygen barrier. Optinally, an oxygen-permeable layer is between the coating and the oxygen barrier. The indicator is activated...     

Described are photochromic spiro(indoline)benzoxazine compounds having substituents on the benzoxazine portion of the compound, and their use in plastic hosts to impart a photochromic response thereto.

A series of novel photochromic spiropyrans are disclosed in which a spiro-adamantane group is introduced into the 2-position of the benzopyran or naphthopyran ring. The spiropyran compounds of the invention exhibit heliochromic properties, i.e. they color in sunlight and fade rapidly at ambient temperatures...     

Described are photochromic spiro(indoline)benzoxazine compounds having substituents on the benzoxazine portion of the compound, and their use in plastic hosts to impart a photochromic response thereto.

A plastic organic photochromic article, typically a lens such as an ophthalmic lens or a window such as a vehicle roof light, comprisig a plastics host material having a photochromic compound incorporated therein or applied thereto, the article exhibiting the following properties, measured at Air Mass...     

There are provided compounds which give quasi-liquid crystals, which comprise a mesogenic group, which can contain bridging groups, a bridging group and a spiropyran moiety having a 2H pyran ring, a terminal group being attached to the mesogenic group. The mesogenic group contains two aromatic, heterocyclic...     

Thermochromic compounds containing the [Pt(dipic)Cl].sup.- anion. These compounds are yellow and monomeric at high temperatures or in low concentrations and abruptly change to red and polymeric at low temperatures or higher solution concentrations. This unusual property allows them to be used as temperature...     

Described is photochromic particulate material comprising a photochromic substance within a matrix of a polymerizate of a polyfunctional acrylate monomer. The photochromic particulate material may be produced by adding an organic photochromic substance to a polymerizable composition including a polyfunctional...     

Described are a series of novel photochromic benzopyran and naphthopyran compounds in which two cyclopropyl groups are appended at the 2-position of the benzopyran or naphthopyran ring. Also described are organic host materials that contain or that are coated with such compounds. Articles such as ophthalmic...     

An image forming device is provided which comprises an image forming layer containing molecules of an organic compound capable of phase transition, and functional molecules such as those of a photochromic compound. An image forming process is also provided which employs the above-mentioned device.

Compositions of matter and methods of preparation are described for water and air stable, square planar transition metal double-complex salts which contain isonitrile ligands derivatized with long chain aliphatic groups. These salts are composed of two metal-containing complex ions: the cation is a tetrakis...     

Described are a series of novel benzospiropyran and naphthospiropyran compounds in which a norcamphor group (or its alkyl-substituted homologues) or a tricyclodecane group (or its alkyl-substituted derivatives) are appended at the 2-position of the benzospiropyran or naphthospiropyran ring. Also described...     

An optical resonant assembly which comprises a plurality of partially light-transmitting mirrors, a layer of photochromic material disposed between the mirrors, a light source providing a light beam of variable intensity incident on the layer of photochromic material and detecting means for determining...     

A photochromic article having improved photochromic equilibrium response is described. In particular, a photochromic compound is incorporated into or applied to an article, e.g., matrix, of a synthetic organic resin prepared from a composition comprising from about 55 to about 90 weight percent of a...     

A photochromic material adapted for coating light transmissive materials. The photochromic material contains photosensitive silver halide crystals having dimensions in the range of approximately 50 Angstroms to 800 Angstroms. The silver halide crystals are surface doped with copper ions and another sensitizer...     

An electrochromic resin composition comprising (A) 100 parts by weight of a network comprising a crosslinked polymer containing 4,4'-diaminodiphenylmethane units in a form in which the amino groups in the formula are quaternized, and (B) 5 to 150 parts by weight of an electrolytic material uniformly...     

The invention relates to compounds of formula I ##STR1## wherein R.sup.1 is C.sub.12 -C.sub.30 alkyl, R.sup.2 is hydrogen or C.sub.1 -C.sub.30 alkyl, R.sup.3 is C.sub.1 -C.sub.3 -alkyl or C.sub.1 -C.sub.3 alkoxy, R.sup.4 may have one of the meanings of R.sup.3 or is halogen, k and n are each independently...     

In accordance with the present invention, there are provided photo-recording media comprising photochromic compounds having been dispersed or dissolved in stretched films or nematic liquid crystals, the transition moment of light absorption of said photochromic compounds being orientated in a definite...     

An improvement of electrochromic devices incorporating a perfluorosulfonic acid polymer ion conducting layer interposed between a working electrode and a counter electrode. The improvement relates to the composition of the perfluorosulfonic acid polymer of the ion conducting layer. In the present invention...     

The invention relates to a heat-shrinkable article that is at least partially coated with a temperature indicator. This temperature indicator is composed of an organic polymer having a suitable bonding agent, whereby the organic polymer is contained therein in a finely ground condition. As a result of...     

A thermochromic effect coating is provided which that it comprises an aqueous binder component including a flop effect pigment and an encapsulated thermochromic liquid crystal pigment. The particular combination in accordance with the present invention results in a coating with altered flop effect from...     

Described are a series of novel photochromic benzopyran and naphthopyran compounds substituted with (1) a cyclopropyl group and (2) a phenyl, substituted phenyl, or 5-member aromatic heterocyclic group at the 2-position of the benzopyran or naphthopyran ring. Also described are organic host materials...     

The photochromic material of the invention is such that a composition having an organic photochromic compound dissolved or dispersed in a hindered amine-type compound is microencapsulated. The photochromic material of the invention is not deteriorated in photochromic properties and can be used for a...     

An electrolyte for electrochromic elements which comprises an electrolytic base material to conduct ions and charge-controlling substances contained in the electrolytic base material. The electrolytic base material is composed of a polar organic solvent and a supporting electrolyte and the charge-controlling...     

The resistance to yellowing caused by post formation heating of a solid organic polymer produced by polymerizing a polymerizable composition comprising: (a) from about 55 to about 89 percent by weight poly(allyl carbonate)-functional material selected from the group consisting of poly(allyl carbonate)-functional...     

A photochromic material adapted for coating light transmissive materials. The photochromic material contains photosensitive silver halide crystals having dimensions in the range of approximately 50 Angstroms to 800 Angstroms. The silver halide crystals are surface doped with copper ions and another sensitizer...     

This invention relates to the paper-making domain and especially to a forgery-proof safety paper, which includes on its surface and/or in its mass, at least one compound responding to formula: ##STR1## in which: R.sub.1, R.sub.2, R.sub.3 may be either H, OH, or OR, R being a hydrocarbon chain, substituted...     

Disclosed is a photochromic composition comprising an organic photochromic compound and a specific tertiary amine compound which are dissolved or dispersed in a high-molecular compound. Also disclosed are a photochromic film composed of the above photochromic composition and a photochromic laminate having...     

A novel photochromic compound as a photoreactive material making use of photochromism is provided, which compound is expressed by the following formula (1) or (2)): ##STR1## wherein R is alkyl, alkoxy, perfluoroalkyl or cyano; X.sub.1, X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 are each H, halogen,...     

A method of making a photochromic polysiloxane includes the steps of forming a photochromic spironaphthooxazine monomer including an alkene terminated side and, by addition reaction, covalently bonding the alkene carbon to [SiH] moieties of a siloxane polymer. Novel spironaphthooxazine monomers and photochromic...     

A compound represented by the following general formula (II): ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a phenyl group, a benzyl group, a phenethyl group, an alkylamine group having 1 to 4 carbon atoms,...     

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds substituted at the 3 position of the pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl...     

A photochromic composition comprising (A) 100 parts by weight of a compound having at least one epoxy group in the molecule and (B) 0.0001 to 10,000 parts by weight of a photochromic compound. The compound (A) is represented by the following general formula ##STR1## wherein A is a residue of an n-valent...     

A novel photochromic spironaphthopyran composition having the general structural formula: ##STR1## in which phenyl substituents positioned adjacent to the oxygen of the pyran ring are linked at their adjacent ortho positions by the functionality (R).sub.n wherein n is the integer 0-2 and wherein R is...     

Described are novel reversible photochromic benzopyran compounds, examples of which are compounds substituted at the 2 position of the pyran ring and have fused at the benzo portion of the benzopyran a substituted or unsubstituted heterocyclic ring such as a benzothieno or benzofurano group. Also described...     

Dispersions of electrically conductive particles useful for preparing electrically conductive, essentially ionically isolative composite layers having electrically conductive particles dispersed in a polymer matrix. Composite layers can be used in laminates for electrochromic displays where an ionically...     

A photochromic plastic has been discovered which is useful in the manufacture of protective eyeglasses. The photochromic plastic comprises a host polymer material and a dopant. The plastic exhibits photochromic properties due to excited state absorption which occurs when the material is exposed to UV...     

The present invention provides a novel photochromic material which is capable of forming two kinds of aggregates, each having a sharp absorption peak at a different wavelength. The photochromic material comprises a spiropyran compound represented by the following general formula: ##STR1## wherein R.sup.1...     

Described are novel reversible photochromic benzopyran compounds, examples of which are compounds having the 2,3 position of a benzofurano or benzothieno group fused to the f, g, or h side of the benzopyran, or a benzo group fused to the f side of the benzopyran, and (i) a substituted or unsubstituted...     

Compounds of the formula I ##STR1## in which X is O, S, SO, SO.sub.2 or NR.sub.13, R.sub.13 is, for example, methyl, and R.sub.1 to R.sub.12, independently of one another, are, for example, H, C.sub.1 -C.sub.12 alkyl, C.sub.1 14 C.sub.12 alkoxy, halogen or --CN. The compounds are photosensitive and photochromic...     

Materials, films, methods, and systems are described which relate to infrared imaging using a polymeric semiconductor compound having an infrared absorption band crosslinked with a spiroypran capable of producing a visible absorption band. These materials, films, methods, and systems are adapted to produce...     

Photochromic compounds having the following structure II ##STR1## in which R.sup.1 is a group selected from hydrogen, alkyl, alkoxy, amino, aryl or heteroaryl; each R.sup.2 is a group selected from C1 to C10 branched or linear alkyls, carbocylic or heterocyclic, the R.sup.2 groups can be independent...     

Photochromic materials which have a structure which includes a spiro-pyrrolidinebenzoxazine structure comprising a pyrrolidine part and a benzoxazine part and the benzoxazine part includes at least one mesomeric electron donating group chosen from amino and alkoxy moieties, the one or more mesomeric...     

A photo reactive material, such as a photochromic material, which has the following structure: ##STR1## where the variables, A, R, R', R", R*, R.sup.+, m, and n are defined in claim 1.

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,...     

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds having certain substituents at the number 5 and 6 carbon atoms 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...     

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds substituted at the 3 position of the pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl...     

A photochromic composition comprising (A) 100 parts by weight of a compound having at least one epoxy group in the molecule and (B) 0.0001 to 10,000 parts by weight of a photochromic compound. The compound (A) is represented by the following general formula ##STR1## wherein A is a residue of an n-valent...     

Described are novel reversible photochromic naphthopyran compounds which have two phenyl moieties adjacent to each oxygen of each pyran ring. The substituents on each pair of phenyl moieties mirror one another when the phenyl groups are substituted. The naphthodipyrans are prepared from .beta.,.beta.-dihydroxynaphthalene...     

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...     

A color changing pigment composition which changes color reversibly when ted comprising (a) a cyclic aryl lactone dye, (b) a diaminoalkane activator and (c)an ester. The pigment composition can also include a white pigment such as titanium dioxide as an opacifier or a yellow dye such Hansa yellow G....     

Materials, films, methods, and systems are described which relate to infrared imaging using a polymeric semiconductor compound having an infrared absorption band crosslinked with a spiroypran capable of producing a visible absorption band. These materials, films, methods, and systems are adapted to produce...     

Described are novel reversible photochromic phenanthropyran compounds, examples of which are substituted 2H-phenanthro 4,3-b!pyran and 3H-phenanthro 1,2-b!pyran compounds. The 2H-phenanthropyran compounds have certain substituents at the number 5 and 6 carbon atoms of the phenanthro portion of the phenanthropyran...     

A naphthopyran compound of general formula (I) ##STR1## wherein R.sub.1 represents an alkyl group or an aryl group; 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...     

A naphthopyran compound represented by the formula: ##STR1## wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, and R.sub.11 are each selected from the group consisting essentially of hydrogen, a first stable organic radical, a heterocyclic group, halogen, a first nitrogen-substituted...     

Methods for making optical quality plastics lenses with photochromic additives are described. According to a first embodiment of the invention, a casting resin is containing photochromic additives is arranged between a mold and a lens preform and then cured. According to a second embodiment of the invention,...     

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds substituted at the 3 position of the pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl...     

Described are novel reversible photochromic benzopyran compounds, examples of which are compounds substituted at the 2-position of the pyran ring with a dibenzo-fused 5 member heterocyclic compound; other enumerated substituents at the other 2-position of the pyran ring; and a substituted or unsubstituted...     

A reversible thermochromic composition develops fluorescent color of yellow, yellowish orange, orange, reddish orange, or red with a high color density and high color brightness, yet gives no residual color under non-color-developing conditions, and has remarkably improved light resistance. The reversible...     

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,...     

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds having certain substituents at the number 5 and 6 carbon atoms 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...     

Described are novel reversible photochromic 3H-naphtho[2,1-b]pyran compounds, examples of which are substituted with an oxy-bearing substituent at the number 8 carbon atom and with either an alkyl group at the number 7 carbon atom or with a carbonyl bearing substituent at the number 9 carbon atom and...     

Described are novel reversible photochromic naphthopyran compounds substituted at the number eight carbon atom on the naphtho portion of the naphthopyran ring with, for example, a methoxy group. Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically...     

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...     

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,...     

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...     

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...     

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.

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....     

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...     

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...     

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...     

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...     

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...     

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,...     

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...     

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...