Properties of calcined kaolins in anticorrosion paints depending on PVC,chemical composition and shape of particles

The properties of calcined kaolins in paints were identified in relation to their pigment volume concentration (PVC). The study involved three kinds of kaolin exhibiting different development of the lamellar structure of primary particles as well as different distribution of particle size. Kaolins also displayed varying contents of a glassy phase – mullite and quartz. Prepared model paints were formulated with the increasing content of kaolins, with PVC ranging from 5 to 40% up to a maximum critical pigment concentration (CPVC), i.e. up to a point where PVC = CPVC. The properties of paints were tested by means of laboratory corrosion tests in the environments of neutral salt mist and of condensed humidity. It was the aim of the study to identify the effect of kaolin's PVC on the mechanical and corrosion resistance of coatings based on water-borne epoxy resin.