Study On Preparation Of Ion-exchange Anti-corrosion Pigments

Traditional anti-corrosion paint is not only rich in organic solvents, but also contains many toxic substances which caused great pollution on the environment. Many countries around the world are trying hard in developing anti-corrosion paint on the environment-friendly, the mechanism were also studied. Meanwhile, people have developed many long-term anti-corrosion paint of low toxic or nontoxic. Ion exchange-type non-toxic anti-corrosion paint is come into being in such circumstances. It is non-toxic, free of heavy metals, with good rust-proof performance and synergistic effect, wide applicability, no pollution, and simple process.Based on the statement of status of anti-corrosion pigments and principles of corrosion paint corrosion both domestic and abroad, the preparation of calcium ion exchange-type anti-corrosion pigments and the performance of the pigments in the coatings has been studied in this paper.1. Two kinds of ion-exchange type anti-corrosion pigments were prepared as a carrier by aluminum silicate and silica gel. The structure and properties of silica gel and aluminum silicate were described, and the outstanding properties of the two raw materials in ion exchange and physi-chemical adsorption were analyzed.2. Anti-corrosion mechanism and protection principles of the ion exchange-type anti-corrosion pigment for iron and steel have been studied. Silica and aluminum silicate were used as raw materials to prepare ion-exchange pigment, in the experiments,, the effect of calcium ion source, reaction time, boiling time, raw material type on the amount of calcium as the quota exchange were studied. By used single factor experiments and orthogonal test method, the optimum process conditions for preparing the two kinds of anti-corrosion pigments were determined.3. Structure and properties were determined by using XRD, laser particle size analysis and oil content was determined, test on its effectiveness in anti-corrosion coatings was done. Alkyd paints prepared by the two calcium ion exchanged pigments were coated on the thin steel plate, the performance of the coating in 3% NaCl solution was tested. The results show that, in this study, the prepared anti-corrosion paint containing ion exchange-type pigments have achieved the requirements of the standard of ZBG51006-87 C53-31 Red Lead Alkyd antirust. The anti-corrosive time in salt water can be 144h, which is much higher than the national standard of 96h. It is also found that there are some differences between the two different carrier pigments in oil absorption and anti-corrosion performance.4. Protection mechanism and anti-corrosion principles of the two kinds of ion exchange pigments were further explored based on the chemical properties of calcium and the electrochemical role of the pigments on the metal surface, it is mainly because of the dense intermediate film formed between the coating and the substrate, which protected the substrate isolated from the external environment.