Copper strip or plate with brown coating and process for the production

摘要

Copper strip or sheet has a dark brown covering layer consisting of a 1st layer, made of Cu2O adhering to the base metal, of thickness of 0.05-5 (pref. 0.1-1) microns, and a second layer made of CuO of thickness of 1-100 (pref. 10-50) nm over the 1st layer. In the prodn. of a covering layer on a semi-finished prod. sheet made of Cu, a strip-like Cu semi-finished prod. is heat-treated at 250-750 degrees C for 0.1-5 mins. in a mixed gas atmos. contg. up to 15 vol.% O2 to form a Cu2O layer, and then heat-treated under oxidising conditions to form a CuO layer at 200-450 degrees C for 1-30 mins. in a mixed gas atmos. contg. 10-21 vol.% O2. Alternatively, a strip-like Cu semi-finished prod. is heat treated at 250-750 degrees C for 0.1-5 mins. for 0.1-5 mins. in a mixed gas atmos. contg. 1-21 vol.% O2, and then treated with an aq. soln. contg. alkaline salt alone or in cpd. with a salt of (in)organic peroxide and oxychloride acids. One surface of the semi-finished prod. is textured before heat treated. Heat treatment is carried out at 450-600 degrees C. The O2 content in the mixed gas atmos. is 3-10 vol.%. The aq. treating soln. has a pH of 10-14. The strip-like semi-finished prod. is electrolytically treated in the aq. soln., where the prod. is connected as anode, using a current density of 1-20 A/dm<2>. The strip-like semifinished prod. is deformed by up to 40 (pref. 5-7)%.