Building material quickly forming natural patina

摘要

Material (I), which can quickly form natural Patina, comprises: (a) a base material consisting of Cu(alloy); and (b) a layer made of a cpd. selected from CuCl, CuBr and CuI formed on the base material. Layer (b) has a theoretical thickness of at least 0.1 microns, calculated from the amt. of reduced electricity, when the layer made of the cpd. is subjected to cathodic reduction in a 0.1N aq. KCl soln..Also claimed is a material as in (I), but where layer (b) is made of Cu2O, an amorphous cpd. of Cu and Cl, or Cu and Br, or Cu and I. Further claimed is the prodn. of (I).