PASSIVATING AND LUBRICATING AGENTS FOR GOLD, SILVER AND COPPER SURFACES AND METHOD FOR ITS APPLICATION

摘要

Disclosed is a passivator and lubricant for gold, silver, and copper surfaces and corresponding alloy surfaces. Said passivator and lubricant comprises an aqueous emulsion with a linear fatty alcohol as an emulsifier, especially at least one CSUB12/SUB-CSUB14/SUB fatty alcohol containing about 8 ethoxy units. Preferably, the concentration of the fatty alcohol amounts to about 25 to 35 g/l. An organic hydrophobic thiol compound, particularly hexadecanethiol and/or octadecanethiol, is dissolved in said aqueous emulsion as an inhibitor at a preferred concentration of about 6 to 12 g/l. In order to prepare said emulsion, the emulsifier is first dissolved in a certain amount of water. Said solution is then thoroughly mixed and is preferably heated to a temperature ranging from about 42 to 49°, whereupon the inhibitor is added. The resulting solution is then further mixed until a uniform milky emulsion is obtained. Silver and copper surfaces that are to be passivated are initially treated with said aqueous emulsion and are then rinsed with water, the temperatures of the emulsion and the water being selected so as to exceed the melting point of the inhibitor.