Thermally developable imaging materials containing heat-bleachable antihalation composition

• Main Authors: Goswami, Ramanuj, Ramsden, William D, Zielinski, Paul A, Baird, David G, Weinstein, LuAnn K, Helber, Margaret J, Lynch, Doreen C
• Format: Patent
• Language: English
• Published: 06.05.2003

This invention relates to heat-bleachable antihalation compositions and their use in thermally developable imaging materials such as photothermographic materials. More particularly, it relates to photothermographic imaging materials that comprise a heat-bleachable antihalation composition, and have improved keeping stability. The invention also relates to methods of imaging using these materials. This invention is directed to the photothermographic imaging industry. Photothermographic materials comprise heat-bleachable antihalation compositions in backside antihalation layers. These compositions comprise a hexaarybiimidazole and an oxonol dye that can be represented by the following Structure I:wherein Aand Aare the same or different activated methylene moieties, Lthrough Lindependently represent a substituted or unsubstituted methine group, M represents a counterion, k is the number of M counterions necessary to provide neutral charge for Structure I, p, and q, are independently 0 or 1, and r is 0, 1, or 2. The antihalation composition is typically bleached when subjected to a temperature of at least 90° C. for at least 0.5 seconds.