| abstract |
Disclosed is a class of dyes that can be rendered colorless by the application of heat in a silverless imaging system and which have utility in information recording and display, color hard copy and photographic systems. Certain dye ylides, for example, xanthane dye ylides are disclosed which when incorporated in a thin film can be imagewise heated to develop an image by reason of the ylide dye disassociating in the areas where heated and thereby being rendered colorless. |