Synthesis and properties of pigments based on X_xZn_yFe₂O₄ ferrites with non‐isometric particles

To synthesise anticorrosion pigments of a lamellar and core‐shell type based on Zn, Ca and Mg ferrites for metal protecting paints.

The anticorrosion pigments were synthesised from oxides or carbonates at high temperature. The pigments synthesised had particles with a pronounced lamellar‐tubular shape consisting of MgFe₂O₄; Mg_0.8Zn_0.2Fe₂O₄; Mg_0.6Zn_0.4Fe₂O₄; Mg_0.4Zn_0.6Fe₂O₄; Mg_0.2Zn_0.8Fe₂O₄; ZnFe₂O₄; Ca_0.2Zn_0.8Fe₂O₄; and CaFe₂O₄. The other type of synthesised ferrite pigments were core‐shell anticorrosion pigments where a layer corresponding to the compositions including MgFe₂O₄/KAl₃Si₃O₁₁; Mg_0.8Zn_0.2Fe₂O₄/KAl₃Si₃O₁₁; Mg_0.6Zn_0.4Fe₂O₄/KAl₃Si₃O₁₁; Mg_0.4Zn_0.6Fe₂O₄/KAl₃Si₃O₁₁; Mg_0.2Zn_0.8Fe₂O₄/KAl₃Si₃O₁₁; ZnFe₂O₄/KAl₃Si₃O₁₁; Ca_0.2Zn_0.8Fe₂O₄/KAl₃Si₃O₁₁; and CaFe₂O₄/KAl₃Si₃O₁₁ was applied onto the core – white mica – by a chemical reaction. The pigments prepared were characterised by means of X‐ray diffraction analysis, particle size distribution measurement, and scanning electron microscopy. The anticorrosion pigments synthesised were used to formulate alkyd paints that were tested in corrosion atmospheres.

Lamellar particles were detected in the pigments prepared, whereas quality coverage of the core was identified in the core‐shell ferrites. Good anticorrosion efficiency was detected in all of the pigments synthesised.

The pigments synthesised can be conveniently utilised in paints to protect metal bases from corrosion.

The method of using the ferrites synthesised as metal protecting anticorrosion paints is new. Of great benefit are the application and the method of synthesising the anticorrosion pigments that do not contain any heavy metals and are environmentally friendly.