CHROMIUM-FREE PASSIVATION OF STEEL Russian patent published in 2010 - IPC C23C22/36 C23C22/83 

FIELD: metallurgy.

SUBSTANCE: invention refers to application of coating on metal surface. The procedure for application of conversion or passivated coating on surface of galvanised steel and steel galvanised by hot immersion consists in interaction of said steel with a water treating composition containing film-forming latex polymer including acrylate resin, fluorine-containing acid, phosphorus acid and non-ionogenic polymer surface active substance containing block copolymer of poly-oxy-ethylene/oxy-propylene. Composition for forming conversion or passivated coating contains from 0.01 to 50 wt % of film-forming latex polymer and from 0.01 to 40 wt % H₃PO_4, from 0.01 to 30 wt % of fluorine containing acid, from 0.01 to 20 wt % of poly-oxy-ethylene/oxy-propylene block copolymer, water - the rest, wherein the said composition equals to 100 wt %.

EFFECT: facilitating production of chromium-free conversion or passivation coating on surface of galvanised steel for inhibition of corrosion of metal surface and for raised adhesion of paint or other coating applied on metal surface.

16 cl, 1 ex