A new technical study of eco-friendly copper foil surface passivation treatment

In order to replace the poisonous hexavalent chromium in the passivation treatment technology ofcopper foil, a new passivation treatment technology is studied by using sodium molybdate and phytic acid asadditives. The passivation treatment experiment was conducted directly to the copper foil that had been treatedby coarsening and curing disposition. The effects of the passivation coating are explored by changing thecontent of sodium molybdate, sodium phosphate, zinc oxide and the experimental conditions of current density, passivation time and existence of phytic acid. The optimization process parameters are shown as follows, sodiummolybdate 8 g/L, zinc oxide 3 g/L, sodium phosphate 4 g/L, phytic acid 2 mL/L, current density 0.2 A/dm², passivation time 10 s. The copper foil with good quality obtained under the optimal condition is well -distributed. More importantly, the copper foil has no drawbacks after the antioxidative experiment and saltspray test, which exhibits good antioxidant and anticorrosion ability with promising application.