Zinc Hypophosphite: a suitable additive for anticorrosive paints to promote pigments synergism

M. C. DEYÁ, G. BLUSTEIN, R. ROMAGNOLI Y B. DEL AMO

Journal of Coating Technology and Research (está es Scopus)

Springer

Lugar: Boston; Año: 2009 vol. 6 p. 369 - 376

1547-0091

In this investigation, the synergism promoted by zinc hypophosphite in an anticorrosive pigment mixture is reported. The paper describes the anticorrosive behaviour of a commercial pigment mixture containing zinc hypophosphite, reduced levels of zinc phosphate and zinc oxide. The anticorrosive performance of the pigment mixture was assessed by electrochemical techniques (corrosion potential and linear polarization measurements) employing pigment suspensions. The behaviour of each separate component of the mixture was also studied in the same way. The nature of the protective layer was investigated by scanning electron microscopy (SEM). In a second stage, the anticorrosive properties of the pigment were assessed by incorporating it into alkyd and epoxy paints which were evaluated by accelerated (salt spray and humidity tests) and electrochemical measurements. Experimental results showed that improved anticorrosion protection is achieved in paints with reduced zinc phosphate contents as a consequence of the synergistic interaction between zinc hypophosphite and the other components of the pigment mixture. Keywords: Anticorrosive paints, electrochemical tests, phosphate pigments, zinc hypophosphite.