Substiantially light-insensitive thermographic recording material with improved stability and image-tone

摘要

A substantially light-insensitive monosheet recording material comprising a support and a thermosensitive element containing a substantially light-insensitive organic silver salt, an organic reducing agent therefor in thermal working relationship therewith and a binder, characterized in that the thermosensitive element further contains an unsaturated carbocyclic or heterocyclic stabilizer compound substituted with a -SA group where A is hydrogen, a counterion to compensate the negative charge of the thiolate group or a group forming a symmetrical or an asymmetrical disulfide and the recording material is capable of producing prints with a numerical gradation value defined as the quotient of the fraction (2.5 - 0.1)/(E2.5 - E0.1) greater than 2.3 , where E2.5 is the energy in Joule applied in a dot area of 87 mu m x 87 mu m of the imaging layer that produces an optical density value of 2.5, and E0.1 is the energy in Joule applied in a dot area of the imaging layer material that produces an optical density value of 0.1.