Development of heat-resistant anticorrosion urethane siloxane paints

Three two-layer heat-resistant and anticorrosion paints have been formulated from urethane siloxane binder and traditional anticorrosion pigments such as micaceous iron oxide (MIO), zinc phosphate (ZP), and aluminum oxide. These pigments were used as the dominant components of different undercoats or topcoats. Heat-resistant pigments such as silicon nitride and glass-spheres were used in the composition of the topcoats. Thermogravimetric analysis of paints shows that the paint with ZP as dominant component of the undercoat have the highest heat-resistance and stability in inert gas and oxygen. The paint with a combination of MIO and ZP has the best hardness as well as the best protective and anticorrosion properties based on the electrochemical impedance spectroscopy. A maximum synergic effect of the properties of pigments seems to appear in this paint. Surface morphology of paints was studied by means of scanning electron microscopy. Heated at different temperatures and for several hours, paint containing MIO as the dominant component in the undercoat exhibits the best mechanical and adhesion properties.