1996 Volume 45 Issue 8 Pages 460-466
To achieve water repellency and lubricity with corrosion resistance for powder coatings, the surface properties of fluoroplastics (PTFE) particle dispersed saturated polyester coatings were investigated. Lubricity increased with adding about 5 mass% PTFE particles, and the coefficient of friction became 0.07. Water repellency also increased with adding PTFE particles, and the angle of contact was about 140 degree. The surface roughness of powder coatings depends on the kind of PTFE particle. Rough surfaces cause powder coatings to be water repellent under a low PTFE content. Observation with SEM and analysis with EPMA show that PTFE particles segregate on the surface of coating films. This is considered to cause high water repellency and lubricity in a powder coated surface with a relatively low dispersed PTFE content, 20 mass% or less. As a result, PTFE particle dispersed saturated polyester coatings are expected to have excellent water repellency and lubricity, and high corrosion resistance due to the high adhesiveness of saturated polyester on metal without the obstacle of adhesion by fluoroplastics particles.
