Digital thermal printing process using reactive ink

Abstract

A method of digitally printing reactive ink contained in a heat meltable ink layer comprising dyes or pigments or other colorants, using a thermal printer. The ink layer comprises compounds with functional groups capable of reacting with active hydrogen, and compounds with functional groups containing active hydrogen, or functional groups capable of conversion to active hydrogen containing groups. The reactive ink contains one or more blocking agents which prevent initiation of the reaction during thermal printing. An image is thermally printed onto a substrate, at a first temperature, so that the ink is not reacted during the process of printing on to the medium. The image is subsequently transferred or permanently fixed on the substrate by the application of heat and pressure, which removes the blocking agent and reacts the ink, bonding the colorant to the substrate.