Abstract:
Photothermographic materials have increased photospeed provided by gold(III)-containing chemical sensitizers that are used combination with sulfur- and/or tellurium-containing chemical sensitizers. Increased photographic speed is achieved with minimal increase in Dmin. The gold(III)-containing chemical sensitizers are represented by the following Structure GOLD: Au(III)L′rYq GOLD wherein L′ represents the same or different ligands, each ligand comprising at least one heteroatom that is capable of forming a bond with gold, Y is an anion, r is an integer of from 1 to 8, and q is an integer of from 0 to 3.
Abstract:
Photothermographic materials have increased photospeed provided by certain organic solvent-soluble thiourea compounds that can be represented by the following Structure I, II, or III: wherein in Structure I, R1, R2, R3 and R4 are independently alkyl, cycloalkyl, allyl, alkenyl, alkynyl, aryl or heterocyclic groups, or R1 and R2 taken together, R3 and R4 taken together, R1 and R3 taken together or R2 and R4 taken together, can form a 5- to 7-membered heterocyclic ring, in Structure II, R1, R2, R3, R4 and R5 are independently alkyl, cycloalkyl, allyl, alkenyl, alkynyl, aryl or heterocyclic groups, or R3 and R5 taken together, R4 and R5 taken together, R1 and R3 taken together or R2 and R4 taken together, can form a substituted or unsubstituted 5- to 7-membered heterocyclic ring, and in Structure III, R1, R2, R3, R4, R5, and R6 are independently alkyl, cycloalkyl, allyl, alkenyl, alkynyl, aryl or heterocyclic groups, or R3 and R6 taken together, R4 and R5 taken together, R1 and R3 taken together, R2 and R4 taken together, or R5 and R6 taken together, can form a substituted or unsubstituted 5- to 7-membered heterocyclic ring, and R7 is a divalent aliphatic or alicyclic linking group. In addition, the speed increasing compounds represented by Structure I do not require a heat activation step at 30° C. or higher temperature for at least 5 minutes and have a pKa of at least 7. Compounds of Structure I are also free of exocyclic carbon-carbon double bonds and nucleophilic groups.
Abstract:
An infrared sensitized photothermographic silver halide element comprising a support layer having on at least one surface thereof a photothermographic composition comprising a binder, a light insensitive silver source, a reducing agent for silver ion and infrared radiation sensitive preformed silver halide grains having number average particle size of 30, and an IR absorbance of at least 0.3 within the range of 750-1400 and an optical density of less than 0.03 in the visible region.
Abstract:
Photothermographic emulsions and materials that are highly sensitive to imaging radiation and that provide high contrast images are provided by making the emulsions with photosensitive silver halide grains that have been formed in the presence of a hydroxytetrazaindene or an N-heterocyclic compound comprising at least one mercapto group, such as a mercapto tetrazole. Such grains can then be chemically sensitized before or after mixing with an organic silver salt using a sulfur-, tellurium-containing, or gold-containing chemical sensitizing compound, or mixtures thereof.
Abstract:
A negative-acting photothermographic element comprising a support bearing at least one heat-developable, photosensitive, image-forming photothermographic emulsion layer comprising:(a) an iridium doped, preferably iridium-doped core-shell, photosensitive silver halide grains, generally containing a total silver iodide content of less than 10 mole %, the shell having a second silver iodide content lower than the silver iodide content of the core;(b) a non-photosensitive, reducible source of silver;(c) a reducing agent for the non-photosensitive, reducible source of silver;(d) a binder; and(e) optionally at least one compound selected from the group consisting of: a halogen molecule; an organic haloamide; and hydrobromic acid salts of nitrogen-containing heterocyclic compounds which are further associated with a pair of bromine atoms.A process of forming photothermographic emulsions from iridium-doped silver halide grains by forming silver soaps in the presence of those grains is also described.
Abstract:
An infrared sensitized photothermographic silver halide element comprising a support layer having on at least one surface thereof a photothermographic composition comprising a binder, a light insensitive silver source, a reducing agent for silver ion and infrared radiation sensitive preformed silver halide grains having number average particle size of 30, and an IR absorbance of at least 0.3 within the range of 750-1400 and an optical density of less than 0.03 in the visible region.
Abstract:
A negative-acting photothermographic element comprising a support bearing at least one heat-developable, photosensitive, image-forming photothermographic emulsion layer comprising:(a) an iridium doped, preferably iridium-doped core-shell, photosensitive silver halide grains, generally containing a total silver iodide content of less than 10 mole %, the shell having a second silver iodide content lower than the silver iodide content of the core;(b) a non-photosensitive, reducible source of silver;(c) a reducing agent for the non-photosensitive, reducible source of silver;(d) a binder; and(e) optionally at least one compound selected from the group consisting of: a halogen molecule; an organic haloamide; and hydrobromic acid salts of nitrogen-containing heterocyclic compounds which are further associated with a pair of bromine atoms.A process of forming photothermographic emulsions from iridium-doped silver halide grains by forming silver soaps in the presence of those grains is also described.
Abstract:
Silver halide emulsions lack stability in that their properties vary over a period of time. Various stabilizers have been used to reduce the rate and degree of variation. The combination of uracils and nitroso-substituted phenols has been found to provide a synergistic stabilization of speed in silver halide emulsions. Other stabilizers may be combined with those two classes to further improve the stability of the emulsion.
Abstract:
An infrared sensitized photothermographic silver halide element comprising a support layer having on at least one surface thereof a photothermographic composition comprising a binder, a light insensitive silver source, a reducing agent for silver ion and infrared radiation sensitive preformed silver halide grains having number average particle size of 30, and an IR absorbance of at least 0.3 within the range of 750-1400 and an optical density of less than 0.03 in the visible region.
Abstract:
Photothermographic imaging materials having increased photospeed are provided by certain tellurium chemical sensitizers that are added during the formulation of a photothermographic emulsion. These useful chemical sensitizers are represented by the following Structure I or II: Te(L)m(X1)n (I) Pd(X2)2[Te(R′)2]2 (II) wherein X1 and X2 independently represent halo, OCN, SCN, S(C═S)N(Ra)(Rb), S(C═S)ORa, S(C═S)SRa, S(P═S)(ORa)(ORb)2, S(P═S)(Ra)(Rb), SeCN, TeCN, CN, SRa, ORa, N3, alkyl, aryl, or O(C═O)Ra groups, Ra and Rb are an alkyl, alkenyl, cycloalkyl, heterocycyl, or aryl group, or Ra and Rb taken together can form a 5-, 6- or 7-membered heterocyclic ring, L is a ligand derived from a neutral Lewis base, R′ is an alkyl or aryl group, m is 0, 1, 2, or 4, and n is 2 or 4 provided that when m is 0 or 2, n is 2 or 4, and when m is 1 or 4, n is 2, and further provided that multiple X1, X2, L, Ra, Rb, or R′ groups in the molecule can be the same or different groups.