Abstract: The new compounds of the general formula ##STR1## where R.sub.1 is hydrogen, alkyl or cyclic alkyl, R.sub.2 and R.sub.3 are each hydrogen, alkyl, a carboxylic acid, ester or amide group or cyano, and R.sub.4, R.sub.5 and R.sub.6 are each alkyl or aryl, are useful as antihalation dyes and as image dyes in photographic materials for dye-bleaching processes.

Abstract: Photographic light-sensitive materials particularly useful in connection with instant photography are disclosed. The disclosed photographic materials include films for instant photography which have a reduced image appearing time, a high Dmax and low Dmin. The disclosed materials include force-oxidized carbon black in liquid phase, which has a dispersibility of at least 4 in water.

Abstract: The present invention relates to a silver halide photographic light-sensitive material, and particularly to a silver halide photographic light-sensitive material containing a hydrophilic colloidal layer dyed by a dye useful as a light-absorbing dye.

Abstract: Light sensitive layers in photographic elements are protected against exposure to radiation in the blue region of the visible spectrum by a yellow filter dye having the structure: ##STR1## where: R.sup.1 is alkyl of 1 to 3 carbon atoms;R.sup.2 is hydrogen or alkyl of 1 to 3 carbon atoms;R.sup.3 and R.sup.4 are each individually alkyl of 1 to 3 carbon atoms, at least one of which is terminated with ##STR2## and R.sup.5 is alkyl of 1 to 3 carbon atoms or fluoroalkyl of 1 to 3 carbon atoms.

Abstract: In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein each R.sup.1 is the same and is selected from ##STR2## R.sup.2 is alkyl, R.sup.3 is an electron-withdrawing group positioned ortho, meta or para to said N atom, R.sup.4 is hydrogen, alkyl or an electron-withdrawing group positioned ortho, meta or para to said N atom; R.sup.5 is alkyl; X is hydrogen, an electron-withdrawing group or an electron-donating group; and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.

Abstract: An underlayer for a laser recording and data storage medium with a light absorption characteristic suited to a recording laser. The underlayer is formed by creating a nuclei layer in a silver-halide photosensitive emulsion layer and then contacting the emulsion layer with a chromogenic reducing agent and a chromogenic dye coupler. The reflective layer may be formed prior to this step by subjecting the nuclei layer to a monobath having a silver-halide solvent and a silver reducing agent until a reflective surface layer of non-filamentary silver particles is formed, or after the step by chemical vapor deposition or sputtering of a reflective metal layer over the underlayer.

Abstract: A UV sensitive dry silver photothermographic construction for graphic arts use can be freely handled for one to two minutes under cool white fluorescent lighting or incandescent lighting. The construction comprises in sequence:a. a substrate,b. a continuous layer of a dry silver dispersion coating containing an organic silver full soap/half soap blend, a reducing agent, halide ion, and a binder resin, andc. a continuous protective topcoat layer comprising a cellulose acetate resin admixed with an effective amount of a development accelerator,said construction further comprising (1) halide ion in said silver dispersion coating or in said topcoat layer, said halide ion being at least 96 mole percent chloride ion, said halide ion when present in said dispersion coating being admixed in said dispersion subsequent to the admixing of at least a portion of said binder resin with said organic silver soap blend, and (2) an antihalation agent in any of the aforementioned layers or in a separate layer.

Abstract: In the forming of microcellular arrays, such as those useful in photography, a closure is positioned to overlie a plurality of microcells forming a planar array. The closure is selectively removed from one set of micro- cells forming an interlaid pattern with a second set of microcells so that the contents of the first set of micro- cells can be changed without concurrently changing the contents of the second set of microcells.

Abstract: A method of making an underlayer for a laser recording and data storage medium with a light absorption characteristic suited to a recording laser. The underlayer is formed by creating a nuclei layer in a silver-halide photosensitive emulsion layer and then contacting the emulsion layer with a chromogenic reducing agent and a chromogenic dye coupler. The reflective layer may be formed prior to this step by subjecting the nuclei layer to a monobath having a silver-halide solvent and a silver reducing agent until a reflective surface layer of non-filamentary silver particles is formed, or after the step by chemical vapor deposition or sputtering of a reflective metal layer over the underlayer.

Abstract: A heat-developable photosensitive material is disclosed having a high image sharpness. The material is comprised of a heat-developable photosensitive layer which includes an organic silver salt, a photocatalyst, and a reducing agent. An antihalation layer is provided on the opposite face of the material with respect to the side intended for imagewise exposure. The antihalation layer contains a photosensitive halogen-containing compound which reduces the pH of the antihalation layer by photolysis and is colored with a dye which causes a change of color when the pH of the antihalation layer is reduced.

Abstract: A photographic element for tanning development which comprises a support, a layer of silver halide emulsion in non-hardened gelatin including a tanning developer dispersed therein, and over said emulsion layer, a layer of non-hardened gelatin comprising at least one colored pigment dispersed therein, characterized by the silver in said silver halide emulsion layer being present in a quantity of less than 0.6 g/m.sup.2 with a silver/gelatin ratio of less than 0.4. A method for obtaining a colored relief image in such an element is shown.

Abstract: Photographic elements, multicolor filters and receivers are disclosed having supports providing microvessels for materials such as radiation-sensitive materials, imaging materials, mordants, silver precipitating agents and materials which are useful in conjunction with these materials. Processes of forming microvessels and introducing materials therein are also disclosed. Processes of forming images are disclosed employing microvessel containing elements. Image transfer processes are disclosed for producing one or a combination of silver and multicolor subtractive primary images alone or in combination with multicolor additive primary images.

Abstract: A silver halide photographic material having a hydrophilic colloid layer comprising fine polymer particles loaded with a hydrophobic photographic addenda provided on a support wherein the polymer has repeating units formed from a nonionic hydrophobic monomer. The nonionic hydrophobic monomer has the formula ##STR1## R.sub.1 and R.sub.2 individually are a hydrogen atom or methyl group, R.sub.3 is a hydrogen atom, an alkyl or aryl group, and m and n are integers of from 2 to 100 individually.

Abstract: Transfer silver images high in maximum density, contrast and sharpness and small in dependency on developing temperatures are obtained by image wise exposing and developing a diffusion transfer light sensitive material which comprises a support having thereon at least a carbon black-containing layer and a silver halide emulsion layer present on said carbon black containing layer, said carbon black-containing layer and/or layer adjacent thereto containing 3-pyrazolidone compound represented by the following general formula: ##STR1## wherein R.sub.1 and R.sub.2 are hydroxyalkyl or alkyl group of 1-4 carbon atoms, at least one of R.sub.1 and R.sub.2 being hydroxyalkyl group and R.sub.3 is an aryl group.

Abstract: A light insensitive imageable layer comprising a synthetic polymeric binder, a dye, a nitrate salt, and an acid.

Abstract: The sensitometric properties of multicolor diffusion transfer film units may be modified after the photosensitive element has been coated. Sensitometric modification is effected by a photoexposure through a layer of a color correction dye(s). In a preferred embodiment, the color correction dye(s) is bleachable and is contained in a layer over the image-receiving layer.

Abstract: It is desirable to protect color photographic dye images from ultraviolet radiation which tends to cause dyes to fade.It has been the practice in the art to add materials into or above the silver halide emulsions which will absorb ultraviolet radiation but allow transmission of visible radiation.One of the best classes of compounds are the 2-(2'-hydroxyphenyl)-benzotriazoles. These materials absorb ultraviolet radiation well, but tend to have poor solubility, crystallize out of the coating solution and emulsion, and diffuse through the photographic element.A novel class of substituted 2-(2'-hydroxyphenyl)-benzotriazoles has been found to reduce many of these problems.

Abstract: This invention relates to a recording material containing diazo compounds, in particular a microfilm, comprising a film base which is at least partially pervious to visible radiation, a light-sensitive layer and, on the reverse side of the film base, a filter layer which absorbs light in the long-wave ultraviolet spectral range and in the short-wave visible spectral range, wherein the filter layer is composed of a polymer which is insoluble or has been rendered insoluble by cross-linking, and of at least one yellow to orange-colored dye which is compatible with the constituents of the polymer and absorbs light in the range between about 360 nm and about 500 nm. The invention also relates to a process for the manufacture of a recording material.

Abstract: In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein each R.sup.1 the same or different is hydrogen or alkyl, each R.sup.2 the same or different is alkyl or phenyl, R.sup.3 is phenyl or alkyl, Y is an electron-withdrawing group and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds.

Abstract: This disclosure relates to production of a photographic film assembly substantially free of optical pinholes for use as a base for negatives in self-developing film packs. The assembly comprises a paper layer and first and second layers of polyolefin adhered to opposite sides of the paper layer. The paper layer has a caliper of about 2 mils to about 4.5 mils and a basis weight of about 55 g/m.sup.2 to about 125 g/m.sup.2. The first and second polyolefin layers each have a layer weight of about 10 g/m.sup.2 to about 48 g/m.sup.2. Carbon black is uniformly dispersed in at least two out of the three layers. The total amount of carbon black in the assembly is about 2.5 g/m.sup.2 to about 4.0 g/m.sup.2.

Abstract: A silver halide color photographic light-sensitive material which contains at least one compound represented by the following general formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, each represents a hydrogen atom or an aliphatic group; R.sup.5 represents an aliphatic group or an aromatic group, R.sup.6 and R.sup.7, which may be the same or different, each represents a cyano group, a --COR.sup.8 group, a --COOR.sup.8 group or a --SO.sub.2 R.sup.9 group; and R.sup.8 represents an aliphatic group and R.sup.9 represents an aliphatic group or an aromatic group. The silver halide color photographic light-sensitive material has improved color reproduction which is not affected by differences in the ultraviolet light absorption characteristics of the camera lens.

Abstract: In one embodiment, the present invention is concerned with novel xanthene compounds selected from those of the formulae ##STR1## wherein each R.sup.1 the same or different is alkyl, each R.sup.2 the same or different is an electron-withdrawing group having a positive sigma value greater than 0.6, X is ##STR2## wherein R.sup.3 is alkyl, Y is an electron-withdrawing group, n is 0 or 1 and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.

Abstract: Dimensionally stable energy-treated polyester film is coated with an opaque antistatic backing layer of carbon-filled polyacrylate containing an aziridine cross-linking agent.

Abstract: A method is described for stabilizing organic substrate materials having an absorption maximum in the range of from about 300 nm to 800 nm to light which comprises making at least one complex represented by the formula (I) coexist with the organic substrate materials in an amount effective to stabilize said organic substrate material: ##STR1## wherein M represents copper, cobalt, nickel, palladium or platinum, and R.sup.1 and R.sup.2 independently represent a hydrogen atom, an alkyl group, an aryl group, an acyl group, an N-alkylcarbamoyl group, an N-arylcarbamoyl group, or an N-alkylsulfamoyl group, an N-arylsulfamoyl group, an alkoxycarbonyl group or an aryloxycarbonyl group.

Abstract: Optical filter agents and photographic products and processes using same are disclosed. The optical filter agents are pH-sensitive hydrazone compounds conforming to the following structural formula: ##STR1## where R is any group which can provide a double bond for conjugation with the ##STR2## portion of the compound to provide light-absorbing capability or color for the agent at a pH above its pKa, X is a substituent of R providing at least one electron-withdrawing group and each R' can be defined as any substituent that does not impair the light-absorbing capacity of the compound at a pH above the pKa thereof. The pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The pH-sensitive optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurence of fogging during in-light development.

Abstract: Images produced in photothermographic emulsions using silver halide as a light-sensitive material therein suffer from light scattering effects on the silver halide.Acutance dyes, many of which are novel, are disclosed which can absorb scattered light and which are bleached at the development temperature of the photothermographic composition.

Abstract: The present invention is concerned with novel compounds useful in photographic products and processes comprising triarylmethane dyes possessing in their triaryl structure a 4'-oxo-1'-naphthylidene (or a 4'-oxo-1'-phenylidene) moiety and a phenyl moiety substituted in the ortho-position to the central carbon atom with the group ##STR1## wherein R is an alkyl group or a phenyl group, unsubstituted or substituted with a solubilizing group and Y is an electron-withdrawing group.

Abstract: A silver halide photographic light-sensitive material having a hydrophilic organic colloid layer containing a dispersion of a substantially water-insoluble photographic additive dissolved in a phosphoric acid ester represented by the following general formula (I): ##STR1## wherein R.sub.1 represents a saturated alicyclic group; and R.sub.2 and R.sub.3, which may be the same or different, each represents a saturated alicyclic group, an alkyl group or an aryl group.

Abstract: The light stability of organic dyes is improved by the presence of at least one of the complexes represented by general formula (I) or (II) ##STR1## wherein M represents a Cu, Co, Ni, Pd or Pt atom; R.sup.1 and R.sup.4, which may be the same or different, each represents an alkyl group or an aryl group; R.sup.2 and R.sup.3, which may be the same or different, each represents a hydrogen atom, an alkyl group or an aryl group; or R.sup.1 and R.sup.2, and R.sup.3 and R.sup.4 may combine to represent a non-metallic atomic group necessary to form a 6-membered ring; and Z represents a non-metallic atomic group necessary to form a 5-membered ring, 6-membered ring, 8-membered ring, or 10-membered ring.

Abstract: Copy sheet comprising substantially transparent dye layer which can undergo color shift in response to color developer composition. Preferred dye comprises pH sensitive dye and preferred color developer comprises weak acid.

Abstract: A method of stabilizing an organic substrate material such as a photographic dye against the action of light having an absorption maximum between about 300 nm and about 800 nm in wavelength by making co-exist with the organic substrate material at least one compound represented by the formula (I) defined in the specification is disclosed.

Abstract: A method of stabilizing organic substrate materials having an absorption maximum in the wavelength region of about 300 nm to about 800 nm to light which comprises making coexist with the organic substrate at least one metal complex salt represented by the following general formula (I): ##STR1## wherein Cat represents a divalent or a monovalent cation, and n is 1 or 2. A photographic material thus stabilized is also disclosed.

Abstract: A method of stabilizing an organic substrate material having an absorption maximum in the wavelength region of about 300 nm to about 800 nm to light without detracting from the color hue and the purity of the organic substrate material, which comprises making at least one metal complex salt represented by the following formula (I) coexist with the organic substrate material: ##STR1## wherein M represents a Cu, Co, Ni, Pd or Pt atom; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 each represents a hydrogen atom, a halogen atom or a cyano group, or an alkyl group, an aryl group, a cycloalkyl group or a heterocyclic ring which may be attached directly to the carbon atom in the respective ring or through a divalent coupling group, or R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, or R.sup.8 and R.sup.9 may combine to form the non-metal atoms necessary to complete a 6-membered ring; R.sup.

Abstract: Polymeric optical filter agents and photographic products and processes using same are disclosed. The polymeric optical filter agents are pH-sensitive optical filter agents comprising polymeric backbone units having the following hydrazone moiety: ##STR1## where R is a group which can provide a double bond for conjugation with the ##STR2## portion of the moiety to provide light-absorbing capability for the agent at a pH above its pKa, and X represents a substituent of R providing at least one electron-withdrawing group. The polymeric pH-sensitive optical filter agents have a highly colored light-absorbing form at a pH above the pKa and are substantially non-absorbing at a pH below the pKa. The polymeric optical filter agents are useful in photographic film units and processes for the protection of photoexposed photosensitive elements against the occurence of fogging during in-light development.

Abstract: Organic substrate materials having absorption maxima between 300 and 800 nm can be stabilized against the action of light by the presence of at least one compound represented by either of the following general formula (I) or (II): ##STR1## where M represents a metal atom selected from the group comprising Cu, Co, Ni, Pd and Pt; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, may be the same or different and each represents a hydrogen atom, a halogen atom, cyano group, an alkyl group, an aryl group, a cycloalkyl group, or a heterocyclic ring, each of the latter four groups being bonded directly or via a divalent connecting group to the corresponding carbon atom of the benzene ring. Alternatively, R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, or R.sup.3 and R.sup.4, may combine to represent the non-metallic atoms necessary to complete a 6-membered ring.R.sup.5 and R.sup.

Abstract: A photographic material containing a removable antihalo layer comprising an antihalo agent and a mixture of two copolymers of a low alkymethacrylate and acrylic or methacrylic acid.

Abstract: A particular class of novel nitro-substituted dyes has been found to act as effective, heat labile acutance dyes for photothermographic emulsions.

Abstract: The present invention is concerned with novel 3,3-disubstituted-sulfam(na)phthaleins wherein one of the 3-substituents is derived from a 1-naphthol or a phenol substituted in the 2-position with a perhalomethylcarbinol group and wherein the N atom of the sulfam(na)phthalein ring is substituted with ##STR1## wherein R is alkyl or aryl or with ##STR2## wherein Y is hydrogen or an electron-withdrawing group, which compounds find utility, e.g., as pH-sensitive indicator dyes or as photographic light-screening dyes.

Abstract: In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein X is ##STR2## wherein R' is alkyl, Y is an electron-withdrawing group and n is 0 or 1. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds.

Abstract: In one embodiment, the present invention is concerned with novel xanthene compounds of the formula ##STR1## wherein R' is alkyl; Y is an electron-withdrawing group and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds.

Abstract: A method of stabilizing organic substrate materials having an absorption maximum in the wavelength region of about 300 nm to about 800 nm to light which comprises making coexist with the organic substrate at least one metal complex salt represented by the following general formula (I): ##STR1## wherein Cat represents a divalent or a monovalent cation, and n is 1 or 2. A photographic material thus stabilized is also disclosed.

Abstract: Organic substrate materials having absorption maxima between 300 and 800 nm can be stabilized against the action of light by the presence of at least one compound represented by either of the following general formula (I) or (II): ##STR1## where M represents a metal atom selected from the group comprising Cu, Co, Ni, Pd and Pt; R.sup.1, R.sup.2, R.sup.3 and R.sup.4, may be the same or different and each represents a hydrogen atom, a halogen atom, cyano group, an alkyl group, an aryl group, a cycloalkyl group, or a heterocyclic ring, each of the latter four groups being bonded directly or via a divalent connecting group to the corresponding carbon atom of the benzene ring. Alternatively, R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, or R.sup.3 and R.sup.4, may combine to represent the non-metallic atoms necessary to complete a 6-membered ring.R.sup.5 and R.sup.

Abstract: This invention is directed to photographic elements having hydrophilic colloid layers containing loaded particles of from 0.02 to 0.2 micron in average diameter consisting essentially of a loadable polymer, with greater than 2 percent by weight of the polymer being derived from monomers capable of forming water soluble homopolymers. A hydrophobic photographic dye, coupler, developing agent or ultraviolet absorbing compound is loaded into and distributed through the particles. The weight ratio of the hydrophobic photographic dye, coupler, developing agent or ultraviolet absorbing compound to the loadable polymer is from about 1:4 to 3:1.

Abstract: A method of stabilizing an organic substrate material having an absorption maximum in the wavelength region of about 300 nm to about 800 nm to light without detracting from the color hue and the purity of the organic substrate material, which comprises making at least one metal complex salt represented by the following formula (I) coexist with the organic substrate material: ##STR1## wherein M represents a Cu, Co, Ni, Pd or Pt atom; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.6, R.sup.7, R.sup.8 and R.sup.9 each represents a hydrogen atom, a halogen atom or a cyano group, or an alkyl group, an aryl group, a cycloalkyl group or a heterocyclic ring which may be attached directly to the carbon atom in the respective ring or through a divalent coupling group, or R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, or R.sup.8 and R.sup.9 may combine to form the non-metal atoms necessary to complete a 6-membered ring; R.sup.

Abstract: The light stability of organic dyes is improved by the presence of at least one of the complexes represented by general formula (I) or (II) ##STR1## wherein M represents a Cu, Co, Ni, Pd or Pt atom; R.sup.1 and R.sup.4, which may be the same or different, each represents an alkyl group or an aryl group; R.sup.2 and R.sup.3, which may be the same or different, each represents a hydrogen atom, an alkyl group or an aryl group; or R.sup.1 and R.sup.2, and R.sup.3 and R.sup.4 may combine to represent a non-metallic atomic group necessary to form a 6-membered ring; and Z represents a non-metallic atomic group necessary to form a 5-membered ring, 6-membered ring, 8-membered ring, or 10-membered ring.

Abstract: The light stability of organic substrate materials such as photographic dyes is improved by the copresence of at least one of the complexes shown by following formulae I, II, III, or IV ##STR1## wherein M represents Cu, Co, Ni, Pd or Pt; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each represents a hydrogen atom, a halogen atom, a cyano group or an alkyl group, an aryl group, a cycloalkyl group or a heterocyclic group bonded directly or through a divalent connecting group to the carbon atom of a benzene ring; or R.sup.1 and R.sup.2 ; R.sup.2 and R.sup.3 ; or R.sup.3 and R.sup.4 combine to represent the non-metallic atoms necessary to complete a 6-membered ring; R.sup.5 and R.sup.8 each represents a hydrogen atom, an alkyl group, or an aryl group; R.sup.6 represents a hydrogen atom, an alkyl group, an aryl group, or a hydroxyl group; R.sup.7 represents an alkyl group or an aryl group; and Z represents the non-metallic atoms necessary to complete a 5-membered or 6-membered ring.

Abstract: A method of stabilizing an organic substrate material such as a photographic dye against the action of light having an absorption maximum between about 300 nm and about 800 nm in wavelength by making co-exist with the organic substrate material at least one compound represented by the formula (I) defined in the specification is disclosed.

Abstract: Dyestuffs of the formula ##STR1## are provided wherein R.sub.1 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, amino or substituted amino, amido or substituted amido or hydroxyl, alkoxy, thioalkoxy or a carboxyl group or an ester thereof, R.sub.2 represents either --N.dbd. or a linking group .dbd.CH--(CH.dbd.CH).sub.n -where n is 0, 1 or 2 and R.sub.3 is an optionally substituted heteroaromatic ring which optionally may be benzannelated, an optionally substituted benzene ring, an optionally substituted 5- or 6-membered heterocyclic or carbocyclic ring, which contains at least one hydroxyl group and may optionally be benzannelated, or R.sub.

Abstract: Pyrylium, thiapyrylium and selenapyrylium salts and derivatives thereof having a trimethine linkage containing an aryl substituent attached to at least one carbon atom of the trimethine linkage are disclosed. Radiation sensitive compositions, e.g., photoconductive compositions, containing such materials are also disclosed.

Abstract: Pyridone dyestuffs of the formula ##STR1## are provided wherein R.sub.1 is hydrogen or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical or an optionally substituted amino group,R.sub.2, R.sub.3, R.sub.4 each independently represent hydrogen, halogen, alkoxy, or optionally substituted alkyl or cycloalkyl,R.sub.5 and R.sub.6 each independently represent hydrogen or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical or R.sub.5 and R.sub.6, R.sub.3 and R.sub.5 and R.sub.4 and R.sub.6 form heterocyclic rings,Y is hydrogen or hydroxy, --CN, --COOR.sub.7, --CONR.sub.7 R.sub.8 or --COR.sub.7 or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical, andZ represents --CN, --COOR.sub.9, --CONR.sub.9 R.sub.10, --SO.sub.3 H, --SO.sub.3 .crclbar. or --COR.sub.9, where R.sub.7, R.sub.8, R.sub.9 and R.sub.10 each independently represent hydrogen or an optionally substituted alkyl, aralkyl, cycloalkyl, aryl or heterocyclic radical.