| abstract |
A high sensitivity thermal paper resistant to image erasure has a colour forming composition comprising a chromogenic material, an acidic developer material, a water insoluble hydrocarbon resin selected from poly- alpha -methylstyrene or alpha -methylstyrene/vinyltoluene copolymer, a thermal modifier and a binder. Preferably the thermal modifier is acetoacet-o-toluidine, diphenoxyethane, phenyl 1-hydroxy-2-naphthoate, diheptadecyl ketone or octadecanamide. The disclosed composition when thermally imaged is surprisingly resistant to image erasure and smearing attributable to fingerprint oils. |