| 摘要 |
NOVEL RECORDING MATERIAL This invention relates to novel recording materials which employ color-forming di- and triarylmethane compounds possessing certain S-containing ring-closing moieties, namely, a 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. |
