COPPER PHYSICAL DEVELOPER FOR INTENSIFICATION OF SILVER IMAGES ON LOW-SILVER PHOTOGRAPHIC MATERIAL Russian patent published in 1994 - IPC

FIELD: photography. SUBSTANCE: copper physical developer contains copper sulfate, alkali metal tartrate, metol, sulfite, sodium hydroxide, water and additionally oxyethylenediphosphonic (OEDPhA) and boric acids, as well as ethonium [1,2-ethylene-bis-(N-dimethyl-carbodecyloxymethyl) ammonium chloride] and diaminophenol hydrochloride, at the following quantitative composition of components, g/l: CuSO₄·5H₂O - 14.70 to 20.30, ethonium - 0.05 to 0.07, OEDPhA - 2.50 to 3.40, boric acid - 2.0 to 2.70, Rochelle salt ((K₁NaC₄H₄O₆·4H₂O)) - 49.0 to 67.60, sodium hydroxide - 1.30 to 4.60, sodium sulfite - 7.70 to 10.70, metol - 4.90 to 6.80, diaminophenol hydrochloride - 1.30 to 1.70, water - up to 1. EFFECT: facilitated procedure.