WEATHER RESISTANT COPPER MATERIAL AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide a weather-resistant copper material which can effectively prevent corrosion due to acid rain or the like in a period till natural verdigris is produced, and which is suitable to be used as a structural material of various kinds of external facilities requiring high weather resistance. SOLUTION: A sulfurizing treatment liquid in which sodium sulfide, sodium tetrasulfide and sodium silicate and ammonium thioglycolate are compounded is applied on the surface of a copper material to form a copper sulfide film comprising only a copper sulfide component without mixing a copper suboxide component. The copper sulfide film is preferably formed to 0.05 to 1μm, more preferably 0.1 to 0.5μm in the thickness.