No abstract

Purpose -The purpose of this paper is to synthesize anticorrosion pigments of the perovskite type, YXO 3 , where X ϭ Ti, Zr, Mn or Al and Y ϭ Ca, Sr, La or Fe, for coating materials intended for corrosion protection of metals. Also, to synthesize pigments containing hexavalent Mo and W (double perovskites). Design/methodology/approach -The anticorrosion pigments were synthesized from oxides or carbonates by a high-temperature process. The following pigments were synthesized: CaTiO . The pigments were characterized by the physico-chemical properties of the powders, by X-ray diffraction analysis and by scanning electron microscopy. Epoxy-ester coating materials containing the pigments at a volume concentration PVC ϭ 10 per cent were prepared and subjected to tests examining their physico-mechanical properties and tests in simulated corrosion atmospheres. Findings -The perovskite structure was identified in the majority of the pigments. The pigments were found to impart good corrosion inhibiting properties to coating materials. The highest calculated anticorrosion efficiency was found for paints containing CaMnO 3 or SrMnO 3 as the pigments. Practical implications -The pigments synthesized can be used with advantage in paints intended for corrosion protection of the substrate metals. Originality/value -The use of the above pigments in anticorrosion coating materials to protect metals is new. Especially beneficial are the uses and procedures for the synthesis of anticorrosion pigments which do not contain heavy metals and are acceptable from the environmental protection aspect.

The effect of pigment particle surface treatment with polyaniline and polypyrrole on the corrosion inhibiting properties of organic paints was investigated. Mixed oxides possessing the spinel and perovskite structures were synthesised for the study. Coatings based on an alkyde resin were prepared for the investigation of the corrosion protection properties of the pigments, the surfaces of which had been provided with a polyaniline and polypyrrole layers. Laboratory corrosion tests were applied to the paint films. Polyaniline phosphate was found preferable to polypyrrole as the modifying agent of the pigment surface regarding the pigment's corrosion inhibiting efficiency.