Patent ID: 7022441

Claim:
A silver-free, black-and-white thermographic material comprising a support having thereon at least one imaging layer comprising predominantly a hydrophilic or water-dispersible polymeric latex binder, and further comprising: a) a color developing agent precursor that releases a color developing agent when heated to a temperature of at least 80° C., and b) a cyan dye-forming color coupler that is capable of reacting with said released color developing agent to produce a cyan dye, c) a magenta dye-forming color coupler that is capable of reacting with said released color developing agent to produce a magenta dye, d) a yellow dye-forming color coupler that is capable of reacting with said released color developing agent to produce a yellow dye, and e) an oxidizing agent that is a benzoquinone that is capable of oxidizing the released color developing agent, said material being substantially free of silver metal or reducible silver ions.