Tailored ferrites-kaolin anticorrosive hybrid pigments in solvent-based paints for protection of cold-rolled steel

摘要

Purpose - The purpose of this paper is to determine a new easy route to obtain high performance and economic anticorrosive hybrid pigments based on kaolin and ferrite. The new route is based on depositing a surface layer of an expensive efficient anticorrosive pigment (ferrite) on a bulk of cheap extender pigment (kaolin). The combination of these pigments can add improved properties to the new pigment different from each of its individual components. These improved properties lead to imparting new properties to paint films containing these prepared pigments. Design/methodology/approach - The new prepared hybrid pigments contain different concentrations of deposited ferrite on kaolin surface, are determined using X-ray fluorescence analysis to estimate the concentration of each element in the pigments. The pigments are characterised using different spectro-photometric and analytical methods to prove the deposition of the shell layer and elucidate the structure of their particles. Then, they are incorporated in anticorrosive paint formulations, where their presence in these formulations is between 50 and 75 per cent of the total pigments in the paint formula. A model of the mechanism of protection to the metal substrate is presented. Findings - The results show that the presence of these hybrid pigments imparts excellent corrosion protection to steel substrates, in spite of their different concentrations and loadings in the paint films. Practical implications - These pigments can be applied in other polymer composites, e.g. rubber and plastics as filler and reinforcing agent. Originality/value - Prepared pigments are eco-friendly and can replace other hazardous pigments (e.g. chromates) - also it can replace original ferrite pigments. These pigments can compensate for the presence of other known pigments in markets successfully. The main advantage of these pigments is that they combine both the properties of their counter-parts, and they are of lower cost than the original inhibitive pigment (ferrite). Also, they can be applied in other industries other than paints, e.g. paper, rubber and plastics composites. Show less