| 摘要 |
PURPOSE:To obtain an artificially patinated embossed roofing material having a bluish-green fine appearance by treating the surface of a sulfurized embossed copper roofing material with a mixed aqueous soln. contg. chemicals for corroding copper sulfide and a patina forming agent. CONSTITUTION:The finely uneven surface 3 of an embossed copper roofing material 2 is blackened by sulfurization, and the blackened surface is coated with a mixed aqueous soln. 5 contg. chemicals consisting of copper nitrate and sodium chloride for corroding copper sulfide 4 and a patina forming agent such as NH4Cl. The copper sulfide 4 is corroded with the chemicals and peeled, and the patina forming agent forms artificial patina 8 on the copper surface. The surface of the material 2 is then coated with acrylic clear laquer as usual so as to prevent the peeling of the patina 8. Thus, the desired artificially patinated embossed roofing material is obtd. |
