A Peel Apart Imaging System by Using Decarboxylation Reaction (I)

Principle of the New Imaging System

Abstract

A new peel apart imaging system based on decarboxylation reaction was studied. A polymer layer which contained carbon black and organic carboxylic acid was sandwiched between a cover film and a substrate film. When it was imagewisely exposed to a flash light either through the cover film or through the substrate film, gaseous carbon dioxide evolved and the polymer layer became detachable from the film through which illumination was performed. Therefore, a visible image was obtained by peeling the cover film off.
Organic carboxylic acids with the thermal decomposition temperature below 120°C gave good results when used in this system.
For imge formation, the exposure had to be done through the cover film or through the substrate film to which the polymer layer adhered stronger. The adhesive force depends on the polymers used for the photo-thermal sensitive layers, the cover films and the substrate film.
In one example, a solid solution of acetonedicarboxylic acid in polymethyl methacrylate matrix with dispersed carbon black was coated as an photo-thermal sensitive layer between a polyethylene terephthalate substrate and a transparent cover film with adhesive layer. By imagewise flash exposure through the substrate film, a positive and a negative image was formed on the substrate and the cover film, respectively.
The image of this system showed a high contrast and a resolving power of 2 lps/mm.