Process for the manufacture of printing plates

Claim 1

IN A PROCESS FOR THE MANUFACTURE OF A SILVER IMAGE BEARING ALUMINUM PLATE FOR PRINTING PURPOSES BY APPLICATION OF THE SILVER HALIDE DUFFUSION TRANSFER PROCESS, THE STEPS OF TREATING A PHOTOGRAPHIC MATERIAL CONTAINING A LIGHT-SENSITIVE SILVER HALIDE EMULSION LAYER HAVING EXPOSED AND NON-EXPOSED AREAS WITH A SILVER HALIDE DEVELOPING SOLUTION AND CONTACTING THE SIDE OF THE PHOTOGRAPHIC MATERIAL BEARING THE AT LEAST PARTIALLY DEVELOPED SILVER HALIDE LAYER WITH A SUBSTANTIALLY OXIDE-FREE ALUMINUM SURFACE OF AN ALUMINUM PLATE IN THE PRESENCE OF A SILVER HALIDE OF AN ALUMINUM PLATE IN THE PRESENCE OF A SILVER HALIDE SOLVENT AND OF AN ADHERENCE PROMOTER FOR THE TRANSFERRED SILVER, SAID ADHERENCE PROMOTER BING AT LEAST INITIALLY CONTAINED IN SAID PHOTOGRAPHIC MATERIAL AND BEING A SALT OF A METAL SELECTED FROM THE GROUP CONSISTING OF WATER SOLUBLE CADMIUM AND ZINC SALTS, WHEREBY SAID ADHERENCE PROMOTER AND THE UNDEVELOPED SILVER HALIDE IN THE EMULSION LAYER AT LEAST PARTIALLY DISSOLVES AND SAID UNDEVELOPED SILVER HALIDE DIFFUSES FROM SAID EMULSION LAYER TO SAID ALUMINUM PLATE WHERE REDUCTION OF SAID UNDEVELOPED SILVER HALIDE IS INITIATED BY SAID ALUMINUM SURFACE OF SAID PLATE AND A SILVER IMAGE IS DEPOSITED THAT FIRMLY ADHERES TO THE SURFACE OF SAID ALUMINUM PLATE.