METHOD OF FORMING COBALT OXIDE CONVERSION COATING AND AQUEOUS SOLUTION FOR PREPARING COBALT OXIDE CONVERSION COATING Russian patent published in 1999 - IPC

FIELD: protective coatings. SUBSTANCE: aqueous solution for anticorrosive coatings containing compound Co(NH₃)₆X, where X is Cl, Br, NO₃, CN, SCN, 1/3 PO₄, ? SO₄, C₂H₃O₂, or ? CO₃, is prepared by interaction of Co(II) salt with Mg(NO₃)₂, Ca(NO₃)₂•6H₂O, NaNO₃, KNO₃, or LiNO₃. Concentration of cobalt salt varies from 0.01 M to saturation limit and that of metal nitrate from 0.03 to 2.5 M. According to invention, ammonium acetate is added to concentration from 0.06 to 6.0 M, pH of solution ranging from 5.0 to 9.0. Aluminum substrate is exposed to solution at 20 to 72 C for 3 to 60 min in presence of hydrogen peroxide, washed, and dried. EFFECT: increased density of coating having good adhesion to substrate, and eliminated harmful sewage. 21 cl, 8 dwg