SILVERLESS PHOTOGRAPHIC IMAGES OBTAINED FROM NI(II) CHELATES WITH 8-MERCAPTOQUINOLINE AND 5,8-DIMERCAPTOQUINOLINE

The formation of silverless photographic images consisting of Ni(II) c helates with 8-mercaptoquinoline and 5,8-dimercaptoquinoline from silv er images by three-stage chemical processes (bleaching, fixing, and to ning) has been studied. D-solid black inverted triangle = f(D-Ap) rela tionships, where D-solid black inverted triangle is the optical densit y of a silverless image formed from the initial silver image having D- Ag density, for a wide range of organic compound concentrations in the toning solutions and various durations of the toning stage, have been obtained and analyzed. It has been determined that in the case of 8-m ercaptoquinoline, the image carrier is Ni(II) chelate with this organi c compound having a Ni(II) ion ligand ratio of 1:2, whereas in the cas e of 5,8-dimercaptoquinoline the image carrier is a ''semi-chelate'' p olymeric complex having a Ni(II) ion/ligand ratio of 2:2. The possibil ity of practical application of the process for image amplication and complete silver removal from the photographic layer is discussed.