Effect of Distribution of Fluorine Resin on Hydrophobic Property of Inorganic Coating on Steel Sheet

Abstract

Covering metal with fluorine resin can create a hydrophobic surface on metals for many applications such as self-cleaning, anti-icing, and corrosion resistance. When fluorine resin is dispersed in a coating, the material's hydrophobicity can be controlled by altering the fluorine resin distribution in the coating. This study investigated fluorine resin dispersion effects on the hydrophobicity of an inorganic coating. The fluorine resin coverage was analyzed using X-ray photoelectron spectroscopy （XPS） and scanning low-energy electron microscopy （SLEEM）. Hydrophobicity was evaluated by the water contact angle. The contact angle on inorganic coatings in which fluorine resin was dispersed increased concomitantly with increasing amounts of fluorine resin. Furthermore, the surface coverage of the fluorine resin increased as the fluorine resin amount increased, but the coverage was not directly proportional to the resin amount. Results suggest that the fluorine resin is concentrated in the outermost layer of the coatings. The coating hydrophobicity is determined by the fluorine resin coverage on the outermost layer according to Cassie's law. The water contact angle also depends on the drying temperature of the coatings because the fluorine resin spreads in the outermost layer when the coating is dried at a temperature higher than the resin softening point.