Bleaching of dyes in photosensitive systems

Abstract

A process for producing an imaged article with little or no residual dye stain and with a colored image involving the steps of: (a) exposing a positive- or negative-acting photoresist to radiation having a wavelength in the range of from about 300 to 1100 nm, the photoresist containing: (i) a photosensitive composition; and (ii) a dye, capable of sensitizing a photolyzable organic halogen compound, in reactive association with an aromatic iodonium salt or halogenated triazine compound, thereby forming an image in the exposed or unexposed areas of the photoresist; (b) developing the image resulting from step (a); and (c) bleaching the remaining sensitizing dye in the photoresist by simultaneously heating and exposing the sensitizing dye and aromatic iodonium salt or halogenated triazine compound to radiation having a wavelength in the range of about 300 to about 700 nm at a temperature of at least about 40.degree. C. Optionally, the remaining sensitizing dye in the photoresist of step (b) can be brought into further reactive association with additional aromatic iodonium salt or halogenated triazine compound before or concurrently with the second exposure step involving the simultaneous application of heat and light.

Dependencies are inferred from the claim text.