Salt compound comprised of a ferricyanide anion and a protonated nitrogen- substituted hydrocarbon compound cation, and a stable solution thereof

摘要

A photolithographic plate, method for preparation thereof, and salt compound useful in the preparation, the method involving the treatment of a metallic silver image on a substrate with a homogeneously stable acidic aqueous salt solution comprising a ferricyanide anion for oxidizing the metallic silver and an organic cation capable of forming a water- insoluble, inherently oleophilic complex with oxidized silver, the cation being derived from a protonatable nitrogen-substituted hydrocarbon compound containing a formal imine group therein which is in resonant association with adjacent groups within the hydrocarbon compound.