Abstract: The object of the present invention is to provide a photothermographic material improved in the aging stability of unprocessed photosensitive material and/or in the image stability after the processing, which is a photothermographic material of the invention comprising a support and on the same surface of the support, a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent and a binder, wherein the concentration of chloride contained on the same surface is 1,000 ppm or less based on the organic silver salt.

Abstract: This invention comprises a silver halide photographic element comprising a support with low oxygen permeability and at least one silver halide emulsion layer containing a fragmentable electron donating compound of the formula: X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is present in the emulsion layer, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.4 V; and 2) the oxidized form of X—Y′ undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y′; and, optionally, 3) the radical X• has an oxidation potential≦−0.7V (that is, equal to or more negative than about −0.7V).

Abstract: A photothermographic material comprising: a support; and a photosensitive silver halide, a nonphotosensitive organic silver salt, a reducing agent and a binder, wherein the photosensitive silver halide comprises 90% by mole or more of a silver iodide and has a silver iodobromide structure having an average silver iodide content of 35% by mole or less in vicinity of a surface thereof.

Abstract: A silver halide photosensitive material comprises at least one light sensitive silver halide emulsion layer on a support. The silver halide photosensitive material contains at least one compound capable of undergoing a one-electron oxidation to thereby form a one-electron oxidation product thereof, the one-electron oxidation product being capable of releasing further one or more electrons, and at least one reducing compound having a C/H value of 3 or less, and another reducing compound having a C/H value of more than 3, the C/H value representing a ratio of (the number of Group IV elements)/(the sum of Groups III, V, VI and VII elements).

Abstract: A photothermographic material including a substrate carrying on one surface thereof an image forming layer containing at least a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for a silver ion, and a binder, wherein the photosensitive silver halide has a silver iodide content of 40 to 100 mol %, and an average particle size of 5 to 80 nm, and the photothermographic material contains a compound of the following general formula (1);

Abstract: A process for preparing a photothermographic material with increased photosensitivity, the photothermographic material comprising a support and a photo-addressable thermally developable element, exclusive of a compound R—S(M)n wherein R is an aliphatic hydrocarbon, aryl or heterocyclic group, M is a hydrogen atom, or cation, and letter n is a number determined so as to render the molecule neutral and also exclusive of a compound capable of releasing a mobile dye corresponding to or inversely corresponding to the reduction of silver halide to silver at elevated temperatures, the photo-addressable thermally developable element containing a photosensitive agent in catalytic association with a light-insensitive organic silver salt, a reducing agent for the light-insensitive organic silver salt in thermal working relationship therewith and a binder, comprising the steps of: (i) increasing the photosensitivity of a photosensitive silver halide by chemical sensitisation with a chemical sensitising merocyanine

Abstract: A silver halide photographic emulsion wherein a variation coefficient of an equivalent-circle diameter of all the silver halide grains is 40% or less, and 50% or more of the total projected area is occupied by tabular grains satisfying requirements (i) to (v): (i) silver iodobromide having (111) faces as principal surfaces; (ii) the equivalent-sphere diameter of 0.5 &mgr;m or less, a thickness of 0.20 &mgr;m or less, and an average aspect ratio of 3 or more; (iii) a silver iodide content of 2 mol % or more and 6 mol % or less; (iv) a multiple-structure having a quintuple structure or more in which a silver iodide distribution has at least two maximums from a center to an edge, the first maximum is in a range of 3 to 25% by a silver amount constituting grains, and the second maximum is in a range of 50 to 80%; and (v) ten or more of dislocation lines per grain are present at a fringe portion.

Abstract: A silver salt photohermographic material is disclosed, comprising a support having provided thereon a light-sensitive layer containing light-sensitive silver halide, a light-insensitive organic silver salt and a binder, wherein the photohermographic material exhibits a gradation of 2.0 to 5.0 within the density region of 0.5 and 2.0 on a photographic characteristic curve obtained when the photothermographic material is subjected to exposure of 50 &mgr;J/cm2 and thermal development at 124° C. for 16 sec.; the light-sensitive layer comprises lower and upper layers and a glass transition temperature of a binder contained in the lower layer being higher than that of a binder contained in the upper layer.

Abstract: Disclosed is a silver halide photographic light-sensitive material comprising at least one silver halide emulsion layer on a support, which contains at least one organic gold compound and has a characteristic curve drawn in orthogonal coordinates of logarithm of light exposure (x-axis) and optical density (y-axis) using equal unit lengths for the both axes, on which gamma is 5.0 or more for the optical density range of 0.3-3.0. This silver halide photographic light-sensitive material provides high contrast and high sensitivity.

Abstract: A photothermographic material comprising at least (a) a photosensitive silver halide, (b) a reducible silver salt, (c) a reducing agent represented by the following formula (1), (d) a binder, and (e) a phenol compound represented by the following formula (2) on the same side of a support: wherein, in the formula (1), V1 to V8 each independently represent hydrogen atom or a substituent, L represents a bridging group consisting of —CH(V9)— or —S—, and V9 represents hydrogen atom or a substituent; wherein, in the formula (2), R1 and R2 each independently represent hydrogen atom or a substituent, X1 to X3 each independently represent hydrogen atom or a substituent, provided that the substituents represented by X1 to X3 do not represent hydroxy group, and when the substituents represented by X1 to X3 are bonded to the phenol ring via nitrogen atoms, X1 to X3 represent a nitrogen-containing heterocyclic group or a group represented as —NH—C(&bo

Abstract: A silver halide emulsion comprises an electron-releasing compound of Types 1 to 4:

Abstract: The present invention provides a spectrally sensitized photothermographic silver halide element support having a first surface and a second surface, a photothermographic composition that is to be exposed to a laser being disposed on the first surface of the support. The element has at least one back layer disposed on the second surface of the support. The photothermographic composition comprises silver halide emulsion grains having a number average grain size of less than 0.1 &mgr;m and that are spectrally sensitized with a sensitizing dye having a spectral sensitivity that corresponds to the spectral properties of the laser. The photothermographic composition further comprises an organic silver salt, a reducing agent for silver ions, and at least one dye. In addition, the photothermographic composition has a transmission optical density greater than 0.1 at the exposure wavelength, and the back layer has a transmission optical density greater than 0.1 at the exposure wavelength.

Abstract: A silver halide photosensitive material containing a compound selected from Types 1-4 below which is capable of undergoing a one-electron oxidation to form a one-electron oxidation product (OEOP), and a reducing compound (Type 1) the OEOP is capable of releasing further two or more electrons accompanying a subsequent bond cleavage reaction, (Type 2) the OEOP is capable of releasing further one electron accompanying a subsequent bond cleavage reaction, and the compound having, in its molecule, two or more groups adsorptive to silver halide, (Type 3) the OEOP is capable of releasing further one or more electrons after going through a subsequent bond forming process, and (Type 4) the OEOP is capable of releasing further one or more electrons after going through a subsequent intramolecular ring cleavage reaction.

Abstract: A silver halide color photosensitive material has at least one blue-sensitive silver halide emulsion layer containing a yellow coupler, at least one green-sensitive silver halide emulsion layer containing a magenta coupler, at least one red-sensitive silver halide emulsion layer containing a cyan coupler, and at least one non-lightsensitive layer, on a support. The photosensitive material contains, in at least one of the layers, a compound having a reducing group and a compound having at least three hetero atoms capable of increasing a photographic speed of the photosensitive material in comparison with the case where the material does not contain the same.

Abstract: A process for producing a lightsensitive silver halide emulsion comprising silver halide grains, wherein the emulsion contains tabular silver halide grains in an amount of at least 50% of the total projected area of all the silver halide grains, the average iodine content of all the silver halide grains is at least 2 mol %, and the tabular silver halide grains have at least 10 dislocation lines per grain, wherein the process comprises (step 1) set fourth below, and the process comprises a step of performing chemical sensitization so that a selenium sensitizer is added in an amount of 2.

Abstract: A silver halide photographic material is disclosed, comprising a support having provided thereon at least a silver halide emulsion layer, which contains at least one compound represented by the following formula (I), and has a characteristic curve of gamma value being 5.0 or more in optical density of from 0.3 to 3.0 on the characteristic curve shown on the orthogonal axis of coordinates having equal unit length expressed by logarithmic exposure amount (x axis) and optical density (y axis): (X)l—(L)m—(A—B)n  (I) wherein X represents a silver halide-adsorptive group having at least one of N, S, P, Se and Te atom, or a light absorptive group; L represents a divalent linking group having at least one of C, N, S and O atom; A represents an electron donative group; B represents a releasing group or a hydrogen atom, which forms radical A. by releasing or deproton after oxidation; l and m each represents an integer of from 0 to 3; and n represents 1 or 2.

Abstract: A method of increasing speed of a silver halide color photosensitive material. The photosensitive material has, on a support, a blue-sensitive silver halide emulsion layer, a green-sensitive silver halide emulsion layer, a red-sensitive silver halide emulsion layer, and a nonsensitive layer.

Abstract: Photothermographic imaging materials having increased photospeed are provided by certain selenium chemical sensitizers that are added during the formulation of a photothermographic emulsion. These selenium chemical sensitizers can be used alone or in combination with other sulfur, tellurium, or gold chemical sensitizers as well as with oxidatively decomposed sulfur-containing compounds.

Abstract: A silver halide emulsion is disclosed, comprising silver halide grains, wherein at least 50% of total grain projected area is accounted for by tabular grains having an aspect ratio of 10 to 100 and at least 50% by number of total grains is accounted for by tabular grains having at least 30 dislocation lines per grain in the fringe portion of the grain, and the emulsion contains a compound having a function of permitting injection of at least two electrons into silver halide via photoexcitation by a single photon.

Abstract: A silver halide photographic light-sensitive emulsion comprising a silver halide and a compound represented by the following Formula (I): 1

Abstract: Thermally developable compositions such thermographic and photothermographic emulsions include certain quaternary phthalazine compounds. These emulsions can be used in thermally developable materials such as thermographic and photothermographic materials to provide improved sensitometric and post processing properties. Such materials can have imaging layers on one or both sides of the support.

Abstract: Thermally developable photothermographic materials comprise a backside layer that includes a toner as a backside stabilizer. Useful backside stabilizers include pyridazine, phthalazine, phthalazinone, benzoxazine dione, benzthiazine dione, or quinazoline dione compounds, or derivatives of any of these compounds to provide improved shelf stability. These backside stabilizers can be provided particularly in non-photosensitive compositions that include an antihalation composition.

Abstract: A silver halide photographic light-sensitive material having at least one emulsion layer comprising silver halide grains, with the emulsion layer further comprising at least one compound represented by the following formula (I) and at least one compound represented by the following formula (II), (III), (IV-1), (IV-2), (V-1), (V-2), (V-3) or (VI): (X&Parenclosest;1&Parenopenst;L&Parenclosest;m&Parenopenst;A—B)n  (I)  (Het&Parenclosest;k1&Brketopenst;&Parenopenst;Q1&Parenclosest;k2&Parenopenst;Hy)]k3  (III) wherein the substituents as defined herein the specification.

Abstract: A silver halide photographic element comprises at least one silver halide emulsion layer comprising a silver halide emulsion comprising core/shell silver halide grains wherein the core region comprises silver bromide with from about 5 to about 20% silver iodide and the shell region comprises silver bromide with about 0.1 to about 10% silver iodide and said layer contains a fragmentable electron donor compound of the formula X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is covalently linked directly or indirectly to X, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.

Abstract: A silver halide emulsion comprising at least one gold-containing compound represented by composition formula (1): [Au(0)Lm]Xn  (1) wherein Au(0) is an Au atom having a valence of zero, L is a compound having at least one group capable of being adsorbed to or coordinating with Au(0), m is a value of 0 or more including decimals, X is an ion required for neutralizing electric charge of the compound, and n is a value of 0 or more including decimals.

Abstract: A method for producing an image comprising a step for heat-developing after light exposure a photothermographic material containing elsewhere on a support a non-photosensitive organic acid silver salt, a photosensitive silver halide, a nucleation aid, a binder and at least one compound expressed by the formula (A) below, at a line speed of 140 cm/min or faster: [where R1, R2, R3, X1 and X2 independently represent a hydrogen atom, halogen atom or the like; at least either one of X1 and X2 is a group expressed as —NR4R5, where R4 and R5 independently represents a hydrogen atom, alkyl group or the like] is provided. The method for producing an image of the present invention is successful in raising Dmax (maximum density), suppressing increase in fog during a long-term storage, and suppressing dimensional instability of line width affected by the energy of exposure.

Abstract: The present invention provides a silver halide photographic material that is excellent in photographic speed as well as image graininess and exhibits low residual color even after rapid processing. The silver halide photographic material contains a compound represented by formula (I) and a compound represented by formula (II), as defined.

Abstract: A photothermographic material comprising, on one surface of a support, at least one kind of photosensitive silver halide, a silver salt of an organic acid, a reducing agent for silver ions, and a binder, wherein (1) said material further comprises two or more kinds of organic polyhalogenated compounds, and (2) a melting point of a mixture which consists of the organic polyhalogenated compounds in the same content ratio as the content ratio of said compounds in the photothermographic material is in the range of from −10° C. to 50° C. relative to a heat development temperature for the photothermographic material. The photothermographic material of the present invention shows high sensitivity and superior storability before heat development, and the material can be used for medical images, photoengraving and the like.

Abstract: A silver salt photothermographic material is disclosed, comprising on a support (a) a light-insensitive organic silver salt, (b) light-sensitive silver halide and (c) a reducing agent capable of reducing a silver ion of the organic silver salt to silver upon heating, wherein when the exposed and thermally processed photothermographic material having a density of 3.0 have been kept at 50° C. and 50% RH for 120 hr., the photothermographic material exhibits a variation of density from 3.0 being within ±0.2.

Abstract: Disclosed is a method for chemical sensitization of a silver halide emulsion comprising a sensitization step of subjecting the silver halide emulsion to chemical sensitization with a chalcogen compound or a chalcogen compound and a gold compound to produce silver chalcogenide or gold silver chalcogenide, wherein the chemical sensitization is performed under such conditions that at least a part of the silver chalcogenide or gold silver chalcogenide produced in the sensitization step can be amorphized. This method can provide a silver halide emulsion showing high sensitivity without increasing fog and degrading storability and such a silver halide emulsion.

Abstract: A silver halide photographic emulsion in which tabular grains each having an equivalent-circle diameter of 0.6 &mgr;m or more, a thickness of 0.3 &mgr;m or less, and an aspect ratio of 2 or more account for 70% or more in number of all the grains contained therein, wherein each of the tabular grains has a multilayered structure including two or more layers, at least one of the layers contains 1 to 20 mol % of a chloride with respect to the silver amount contained in the at least one of the layers, and each of the tabular grains contains a metal complex represented by formula (C-1) or (C-2) below: [M1(CN)6-aLa]n  (C-1) [M2(CN)4-bLb]m  (C-2) wherein M1 represents Fe, Ru, Re, Os, Ir, or Pt; M2 represents Pt or Au; L represents a ligand except for CN; a represents 0, 1, or 2; b represents 0, 1, or 2; n represents 2-, 3-, or 4-; and m represents 1- or 2-.

Abstract: A silver halide photographic emulsion comprising grains, wherein 70% or more of the total projected area of the grains is occupied by silver halide grains each meeting requirements (a) to (d) below

Abstract: This invention comprises an imaging element comprising an imaging layer having associated therewith a compound of Structure I: In the above Structure I, the substituents are as defined in the application. Such compounds have good reactivity and can by used to block photographically useful compounds such as developing agents until thermally activated under preselected conditions. Compounds according to the present invention are especially useful in color photothermographic imaging elements.

Abstract: This invention comprises a multicolor photographic element comprising a support bearing a cyan dye image-forming unit comprising at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan dye-forming coupler, a magenta dye image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta dye-forming coupler, a yellow dye image-forming unit comprising at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow dye-forming coupler, wherein at least one of said layers comprises large tabular grains having an average circular diameter of greater than 2 &mgr;m and contains a fragmentable electron donating compound is of the formula: X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a pr

Abstract: A silver halide color photographic light-sensitive material has a support provided thereon a photographic constitutional layer including at least one photographic light-sensitive layer that contains a light-sensitive silver halide, an organosilver salt having a nitrogen-containing heterocycle, a compound capable of forming a dye by coupling reaction with an oxidized developing agent, and a binder, wherein the light-sensitive layer contains: (A) as the silver halide, a silver halide emulsion composed of tabular silver halide grains having a main face made up of a (111) plane, an average diameter of an equivalent circle of at least 0.70 &mgr;m, and an average thickness of less than 0.20 &mgr;m; and (B) as the organosilver salt, a compound in which a hydrogen on a 5- or 6-membered nitrogen-containing heterocycle having at least one —NH— group is replaced with Ag.

Abstract: A multicolor photographic element comprising a support bearing a cyan dye image-forming unit comprising at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan dye-forming coupler, a magenta dye image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta dye-forming coupler, a yellow dye image-forming unit comprising at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow dye-forming coupler, wherein at least one of said silver halide emulsion layers contains a tabular grain silver halide emulsion having a halide content of at least 95% bromide and less than about 5% iodide, said iodide being substantially uniformly distributed in the silver halide grains of said emulsion, and said emulsion is sensitized with a fragmentable electron donor of the formula X—Y′ or an electron donor which contains an —XY′ moiety; wherein

Abstract: This invention comprises a photographic element comprising at least one light-sensitive silver halide emulsion layer containing a fragmentable electron donating compound of the formula: X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is present in the emulsion layer, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.4 V; and 2) the oxidized form of X—Y′ undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y′; and 3) the radical X• has an oxidation potential ≦−0.

Abstract: This invention comprises a photographic element comprising a support and at least one blue sensitive silver halide emulsion layer containing a tabular grain silver halide emulsion, or an emulsion in which the halide content is at least 50% chloride and no more than 5% iodide, wherein the emulsion is spectrally sensitized with at least one dye providing a peak sensitization between 446 and 500 nm and at least one dye providing a peak sensitization between 400 and 445 nm and additionally sensitized with a fragmentable electron donor of the formula: X—Y′. or an electron donor which contains an —XY′ moiety; wherein X is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is H a base, &bgr;−, is covalently linked directly or indirectly to X. and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.

Abstract: This invention comprises a photographic element comprising at least one light-sensitive silver halide emulsion layer containing a fragmentable electron donating compound of the formula: X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein

Abstract: The present invention provides a thermally developable photosensitive material including a support, the image-forming layer containing a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent, a binder and a compound represented by the following formula (I), wherein after the material is exposed and thermally developed at 121° C.

Abstract: This invention provides a photographic element comprising at least one silver halide emulsion layer in which the silver halide is sensitized with a compound of the formula (a): &Dgr;−(t)m−XY′  (a) XY′−(t)m−&Dgr;  (b) &Dgr;−(t)m−XY′−(t)m−&Dgr;  (c) wherein &Dgr; is protective group that is eliminated during development of the photographic element, t is a timing group, m is an integer from 0 to 3, and XY′ is a fragmentable electron donor moiety in which X is an electron donor group and Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is present in the emulsion or is covalently linked directly or indirectly to X, and wherein: 1) X—Y′ has an oxidation potential between 0 and about 1.

Abstract: A red or infrared sensitive silver halide emulsion is disclosed, comprising at least a compound represented by the following formula. A photographic material containing the emulsion is also disclosed.

Abstract: There is disclosed a silver halide photographic light-sensitive material comprising at least one compound selected from the group consisting of the compounds represented by the following formula (1), (2) or (3): wherein R1 represents a phenyl, aromatic heterocyclic or aliphatic group, having at least one electron-withdrawing group as a substituent, PUG represents a residue of a development inhibitor, Y1 and Z1 respectively represent a substituent which is substitutable on a benzene ring, and n1 and p1 denote integers from 0 to 4, Ar represents an aryl group or an aromatic heterocyclic group, PUG represents a residue of a development inhibitor, TIME represents a timing group and t denotes 0 or 1, A represents a connecting group, m denotes an integer from 2 to 6.

Abstract: A silver halide emulsion which exhibits high sensitivity, high contrast, little sensitivity variation with humidity conditions at the time of exposure, and excellent reciprocity law properties at high illumination intensities. Also, a method of preparing the emulsion in a stable manner, and a silver halide color photographic photosensitive material and an image forming method that use the emulsion. The emulsion includes a mesoionic compound having a thiolate structure or a protonated thiolate structure, and the emulsion is sensitized by an Au (III) compound. The emulsion preferably contains an oxidatively dimerized form of a mesoionic compound having a thiolate structure, and a silver chloride content of at least 90 mol %.

Abstract: Image recording materials, especially photothermographic light-sensitive image recording materials, that comprise a compound of formula (1) to acquire excellent image storage stability: wherein X1 and X2 each represent a halogen atom; X3 represents a hydrogen atom, a halogen atom or a univalent substituent group; L represents a divalent organic group; Y represents a divalent organic group containing a hetero atom, or a single bond; and Z represents an acidic functional group or a salt thereof.

Abstract: A silver halide photographic light-sensitive material includes a compound selected from: (1) a quaternary nitrogen or phosphorus salt compound, having 20 or more of total recurring units consisting of an ethyleneoxy group and/or a propyleneoxy group; (2) a quaternary salt compound represented by formula (A): wherein Q represents nitrogen or phosphorus, R1, R2 and R3 represent an alkyl, aryl, alkenyl, alkynyl, or heterocyclic group, L1 represents an alkylene group, Y represents —C(═O) or —SO2—, L2 represents a divalent connecting group having at least one hydrophilic group, Xn− represents an n-valent counter anion, n being an integer of 1 to 3; and (3) a quaternary salt compound represented by formula (B): wherein A represents an organic moiety necessary to complete a nitrogen-containing aromatic heterocyclic ring. L2 represents a divalent connecting group having at least one hydrophilic group that divides L2.

Abstract: Disclosed is a color photographic element comprising at least one of (1) a light sensitive silver halide emulsion layer and (2) a non-silver containing light insensitive layer, said at least one layer containing a compound with a minimum of three heteroatoms that does not react with oxidized developer and that has a ClogP sufficient to increase the photographic speed of said element compared to the same element without the compound. The invention provides improved light sensitivity.

Abstract: A colour photographic silver halide material comprising a support and at least one silver halide emulsion layer which is deposited thereon and which contains at least one colour coupler, characterised in that said layer also contains a compound of formula (I) wherein R1 denotes alkyl, aryl, aralkyl or hetaryl, R2 denotes H or R1, or R1 and R2 together denote the remaining members of a heterocyclic ring, R3, R4, independently of each other, denote aryl or hetaryl or together denote the remaining members of a phenanthrene ring which is condensed-on in the 9,10-position, wherein R1 can also be H if R3 and R4 together form a phenanthrene ring, is distinguished by improved granularity.

Abstract: This invention relates to an imaging element comprising an imaging layer having associated therewith a compound of Structure I: In the above Structure I, the substituents are as defined in the application, wherein B is a six-membered heteroaromatic ring. Such compounds have good reactivity and can by used to block photographically useful compounds such as developing agents until thermally activated under preselected conditions. Compounds according to the present invention are especially useful in color photothermographic imaging elements.

Abstract: This invention comprises multicolor photographic element comprising a support bearing a cyan dye image-forming unit comprising at least one red-sensitive silver halide emulsion layer having associated therewith at least one cyan dye-forming coupler, a magenta dye image-forming unit comprising at least one green-sensitive silver halide emulsion layer having associated therewith at least one magenta dye-forming coupler, a yellow dye image-forming unit comprising at least one blue-sensitive silver halide emulsion layer having associated therewith at least one yellow dye-forming coupler, wherein at least one of said red-sensitive or green-sensitive layers comprises a fragmentable electron donating compound of the formula: X—Y′ or a compound which contains a moiety of the formula —X—Y′; wherein the speed gain deriving from addition of said compound to said layer is less than or equal to 0.