Silver-electroplating process

Abstract

A process for silver-plating, which comprises steps of preplating a substrate material in an aqueous preplating solution comprising 10.sup.-5 to 0.02 mole/l of silver and more than 0.01 mole/l of a silver complexing agent such as thiocyanic ions under non-current density, to preplate a sufficient thickness of silver to restrain or substantially prevent substitution plating, and then electroplating the preplated substrate material until a sufficient thickness by supplying an electric current to said material in an aqueous silver plating solution comprising silver ions, thiocyanic ions and a film improving agent.

Dependencies are inferred from the claim text.