METHOD FOR PREVENTING SUBSTITUTION DURING PARTIAL GOLD PLATING ON COPPER OR COPPER ALLOY MATERIAL

摘要

PURPOSE:To obtain a partially gold plated product having fine appearance and superior quality by immersing a copper (alloy) material in a pretreating soln. contg. a prescribed heterocyclic thion compd. and a prescribed silver compd. and by carrying out partial gold plating. CONSTITUTION:The pretreating soln. contg. the heterocyclic thion compd. such as 3-aminorhodanine, 3-thiourazol or 2-thiouracil and the silver compd. such as potassium silver cyanide or silver nitrate is prepd. The copper (alloy) material is immersed in the pretreating soln. and the prescribed part of the material is plated with gold.