A dissolution system called photosolubilization invented in 1964 by R.K. Blake and applied to silver halide was investigated to determine the feasibility of adapting the system from silver to copper. After cuprous bromide was shown to be light sensitive and able to be insolubilized, using a mercaptan ( 2-mercapto-4-phenylthiazole ), many of the parameters affecting this process were determined. The best photosolubilization was achieved using a 1/100 mole ratio of mercaptan to cuprous bromide. Insolubilization improved with increased mercaptan digestion time while pH appeared to have little effect on this mechanism. PH did change final print-out density. Increased sensitivity was observed when the emulsion was re-exposed while still wet. Fixing or dissolution depends on several factors including emulsion thickness.
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School of Photographic Arts and Sciences (CIAS)
Frisicano, Richard and Harris, Jeffrey, "Photosolubilization of cuprous bromide" (1975). Thesis. Rochester Institute of Technology. Accessed from
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