Patent ID: 7166421

Claim:
A black-and-white aqueous-based photothermographic material comprising a support and having thereon at least one photothermographic imaging layer comprising a hydrophilic polymer binder or a water-dispersible polymer latex binder and in reactive association: a. a photosensitive silver halide, b. a non-photosensitive source of reducible silver ions, c. a reducing agent for said reducible silver ions, and d. at least 0.005 g/m 2 of a tetrafluoroborate salt that is not a spectral sensitizing dye, wherein said tetrafluoroborate salt is an alkali metal or alkaline earth metal tetrafluoroborate, an imidazolium tetrafluoroborate, pyrazolium tetrafluoroborate, pyridinium tetrafluoroborate, pyrimidinium tetrafluoroborate, quaternary ammonium tetrafluoroborate, quaternary phosphonium tetrafluoroborate, or tertiary sulfonium tetrafluoroborate.