Abstract: There is described a novel thermographic recording film, and more specifically, a novel image-forming system incorporated therein which employs both thiolactone and silver reduction chemistries.Thermographic recording films comprising the novel image-forming system of the present invention exhibit excellent thermal sensitivity and visual color saturation, enhanced image density, and desirable visual minimum optical densities.

Abstract: There is described a novel thermographic recording film, and more specifically, a novel image-forming system incorporated therein comprising at least one layer and including and a Lewis acid material, a di- or triarylmethane thiolactone dye precursor, an acidic organic material, a binder and a thermal stabilizer.Thermographic recording films comprising the novel image-forming system of the present invention exhibit excellent thermal stability, and desirable minimum optical densities, indicative of substantially less premature image development at elevated environmental temperatures.Embodiments of the invention wherein the thermographic recording films further include a light insensitive organic silver salt, a reducing agent, a binder and, preferably, a toning agent, show substantially enhanced image density.

Abstract: This invention relates to novel recording materials which employ color-forming di- and triarylmethane compounds possessing certain S-containing ring-closing moieties, namely, or thiolactone, dithiolactone or thioether ring-closing moiety and to a method of forming color by contacting these dye precursor compounds with a Lewis acid material capable of opening the thiolactone, dithiolactone or thioether ring-closing moiety whereby the compound is rendered colored, that is, converted to its chromophore color.

Abstract: This invention relates to the use of 3,5-dihydroxybenzoic acid as an organic acidic reagent in thermographic recording materials comprising a di- or triarylmethane thiolactone dye precursor, silver behenate and a polymeric binder, and in a further embodiment, relates to coating compositions useful in the preparation of the recording materials.