Patent ID: 7135432

Claim:
A black and white non-photosensitive direct thermographic material comprising a support and on one or both sides thereof, one or more thermally sensitive imaging layers having in reactive association, a non-photosensitive source of reducible silver ions and an ortho-amino-phenol, para-amino-phenol, or hydroquinone compound reducing agent for said reducible silver ions, wherein said ortho-amino phenol compounds have a calculated aqueous deprotonation energy of less than 307 kcal/mol and a calculated anion HOMO energy more negative than −4.17 eV, said para-amino phenol compounds have a calculated aqueous deprotonation energy of less than 310 kcal/mol and a calculated anion HOMO energy more negative than −4.18 eV, and said hydroquinones have a calculated aqueous deprotonation energy of less than 311 kcal/mol and a calculated anion HOMO energy more negative than −4.06 eV.