Anti-corrosion properties of composite inhibiting pigment based on natural calcium silicate and zinc monophosphate in alkyd coating on carbon steel

A composite inhibiting pigment based on natural calcium silicateand zinc monophosphate was obtained by mechanochemical modification. Pigment extracts reduce the corrosion current density and increase the resistance to charge transfer of carbon steel in the slightly acidic atmospheric precipitations due to the formation of a protective film on its surface. The presence of phosphorus, zinc, and calcium was found in the composition of this film, which indicates the formation of phosphates. Adding a composite pigment to the priming layer of the alkyd coating significantly increases its corrosion resistance compared to the uninhibited sample. The obtained composite pigment has increased protective properties in the slightly acidic atmospheric precipitations and is promising for use in paint coatings on carbon steels.