VACUUM-DEPOSITED COLORANTS

摘要

A radiation curable monomer and a dyestuff are mixed in a curable formulation and fed into a hot evaporator under vacuum. The blend is flash evaporated through a nozzle (36) and recondensed onto a moving substrate in contact with a temperature-controlled rotating drum (44). The condensed film is then crosslinked with a high-energy ultraviolet or electron-beam radiation source (28) to effect cross-linking of the monomer. The resulting product consists of a crosslinked polymer matrix incorporating dyestuff molecules within its structure, which dramatically enhances the durability, solvent resistance, heat stability and migration fastness of the product. These properties can be further improved by chemically bonding the dyestuff molecules with the crosslinked polymer network, which can be accomplished by judiciously functionalizing the dyestuff with appropriate functional groups designed to polymerize or to react with the curable monomer.