COPPER STRIP OR SHEET WITH A BROWN COVER LAYER AND METHODS FOR ITS PRODUCTION

摘要

A copper strip or sheet having a red-brown to dark brown cover layer. The cover layer includes a first layer of Cu2O which adheres to the base metal, with a thickness in the range of 0.05 to 5 .mu.m, preferably in the range of 0.1 to 1 .mu.m, and a second layer of CuO arranged on top of the first layer, with a thickness between 1 and 100 nm, preferably with a thickness between 10 and 50 nm. The cover layer is applied by heat treating the copper base to form a Cu2O layer, followed by a second heat treatment to form a CuO layer. Alternatively, the cover layer is applied by heat treating the copper base in an oxygen containing atmosphere followed by treatment with an aqueous solution of a salt which produces an alkali reaction. The resulting copper strip or sheet of the invention is well suited for use in the construction sector.