| 摘要 |
PURPOSE:To render a surface of copper multicolored and provide an arbitrary colored pattern to the surface by forming reswellable resin-based coated layers of different thicknesses on the surface followed by dipping in a sulfurizing soln. and removal of the layers. CONSTITUTION:A surface of copper 1 is partially printed with blend 2 based on a reswellable resin such as gelatin, casein or PVA, blend 2' and blend 2'' in order with a difference in size to form coated layers of different thicknesses. The coated surface is dried, humidity-controlled in an atmosphere of a suitable humidity, and dipped in a soln. contg. sulfide such as barium sulfide or potassium sulfide, or polysulfide. The dipping time depends upon a desired colored pattern, the thicknesses of the layers and the concn. of the soln. Since the soln. permeates into the copper surface at different speeds according to a difference in thickness of the layers, a multicolored layer is formed. The coated layers are then peeled by dipping in an aq. soln. of caustic soda or the like. |
