Thermographic recording material having authentication characteristic, contains two or more color formers developing different colors to give image with specific coloristic properties

摘要

A thermographic material (A), comprising a substrate supporting an active coating layer containing color former(s) (I) and developer(s) (II) reacting in presence of heat to form a colored printed image, contains at least two different (I) reacting with (II) to form different, first and second colors. The obtained image has a color formed from the first and second colors, with a color location of specific Lab values as authentication characteristic. A thermographic material (A), comprising a substrate supporting an active coating layer containing color former(s) (I) and developer(s) (II) reacting in presence of heat to form a colored printed image, contains at least two different (I) reacting with (II) to form different, first and second colors. The obtained image has a color formed from the first and second colors, with a color location having the following specific Lab values L*, a*, b* (determined with Elrepho 3000 (RTM: not defined) apparatus using light of type D 65/10) as authentication characteristic: L* = 24-35%; a* = -1 to +30; and b* = -2 to -60.