Protective coatings based on alkali silicate

Abstract

The protective coatings based on the silicate based binders prepared and filled with standard pigments and fillers were hardened by the following methods: physical procedure, zinc powder with isometric spherical particles, zinc powder with lamellar particles, blocked polyisocyanate in an organic solvent, blocked polyisocyanate in water dispersion, with condensed aluminum phosphate, hydrated aluminum phosphate, and alkoxysilyl isocyanurate. With coatings, the physical-mechanical property tests of the coats on steel or glass panels, as the case may be (adhesion by the grid method, bending strengths, cupping stability, shock resistance, and coating hardness) and corrosion resistance in a condensation chamber and salt chamber with cycles tests were performed. The results obtained were evaluated from the silicate binder type point of view, as well as the used hardening system type point of view. The overall best results were obtained with a lithium-sodium water glass, the coats of which exhibit good physicomechanical and anticorrosion properties. From the composition point of view, the coating materials filled with zinc powder exhibit very good results. Zinc with lamellar particle shape exhibits a higher anticorrosion efficiency.