Patent ID: 7026105

Claim:
A photothermographic material comprising a support and having on at least one side thereof, one or more imaging layers comprising a binder and in reactive association: a. photosensitive silver halide grains, b. a non-photosensitive source of reducible silver ions, and c. a reducing composition for said reducible silver ions, wherein said photosensitive silver halide grains have been chemically sensitized with a combination of chemical sensitizers that consists essentially of: 1) a gold (III)-containing compound that is represented by the following Structure GOLD: Au(III)L′ r Y q (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, and 2) a sulfur-containing compound that is a diphenylphosphine sulfide that is represented by the following Structure PS: wherein Ph 1 and Ph 2 are the same or different phenyl groups, R 1 and R 2 are independently hydrogen or an alkyl or phenyl group, L is a direct bond or a linking group, m is 1 or 2 and when m is 1, R 3 is a monovalent group, and when m is 2, R 3 is a divalent aliphatic linking group having 1 to 20 carbon, nitrogen, oxygen, or sulfur atoms in the chain, and the molar ratio of said gold(III)-containing compound to said sulfur-containing compound used in the chemical sensitization is at least 1:1.