Alkalising and neutralising effects of anticorrosive pigments containing Zn, Mg, Ca, and Sr cations

The present paper deals with the possibility of replacing toxic anticorrosive pigments with pigments acceptable from the point of view of environment protection. Spinel pigments containing Zn(II), CaO, Mg(II), Sr(II), Fe(III), Al(III), and Ti(IV) cations were synthesised. Combining these elements gave five various oxide groups, which were applied to alkyd, styrene-acrylate, epoxy-resin and chlorinated-rubber binders. The binder containing acid groups gave aqueous extract with better inhibitive properties than the non-reactive binders. Using spinel pigments allows to significantly inhibit the corrosion reaction in comparison with the corrosion running in pure water. The chemical composition of synthesised pigments clearly shows that the compounds are ecologically harmless. (C) 2000 Elsevier Science S.A. All rights reserved.