PROCESSES FOR CONVERTING ZERO-VALENT METALS PHOTOGRAPHIC IMAGES TO FORMAZAN DYE IMAGES

摘要

A zero valent metal image in which the metal has a standard oxidation potential more positive than -0.98 volt is advantageously converted to a nondiffusible formazan dye image by the single process step of contacting the metal image with a solution of a tetrazolium salt that contains a metal complexing moiety when the combination of tetrazolium salt, metal and water produces a solution reaction potential E of at least +0.01 volt.