The anticorrosive performance of zinc-free non-toxic pigment for paints

The objective of this research was to study the efficiency of calcium aluminium phosphosilicate hydrate (PSh), as anticorrosive pigment for paints in simulated aggressive environments. This compound is zinc-free and the phosphate content is less than 30% by weight. Alkyd and epoxy paints, of the solvent-borne type, containing 30% by volume (v/v) of the pigment, were formulated. The pigment volume concentration was fixed at 42.3%. Standardised accelerated salt spray exposure and electrochemical tests were used to assess the protective performance of the coatings. Analysis and interpretation of the experimental data showed that PSh inhibits corrosion of painted steel panels exposed to aggressive environments. Zinc phosphate (ZP), a traditional anticorrosive pigment, was used as reference in all the essays.