Influence of shape and particle size distribution of natural fillers on the barrier properties of organic coatings

Studies have been carried out in order to verify the criteria for elaborating paint formulations based on the value of critical pigment volume concentration (CPVC), determined on the basis of the packing factor of the mixture of pigments and fillers. The particle size distribution of mixtures, packing factor values and the CPVC values were established based on the authors' own procedure by taking into account the pigment and filler particle size distribution determined by means of the sedimentation method. Based on the data obtained and on the reduced volume concentration value (Lambda) for anticorrosive paints, different paint formulations were developed and the mechanical and protective properties of the obtained coatings were tested. It was found that using the CPVC value as a criterion for the elaboration of paint formulations with a determined. value, and thus with established properties, makes it possible to obtain anticorrosive paints without an active pigment. The properties of such coatings are comparable to coatings containing the anticorrosive pigment.