Optimization of Binary Pigment Coatings

In this effort, an approach was devised and utilized to theoretically predict optimum coating compositions using two parameters, the maximum pigment packing factor and the coating critical pigment volume concentration, CPVC. Five binary pigment systems were evaluated in this study. 1. Titanium dioxide - silicon dioxide, 2. titanium dioxide - antimony oxide, 3. titanium dioxide - zinc chromate, 4. titanium dioxide - vesiculated polymer beads, 5. titanium dioxide - solid polymer beads. Each pigment systems was systematically formulated in a polyurethane resin using a simplex statistical design. After application and cure, the coatings were tested and evaluated for gloss and flexibility to experimentally determine the CPVC of the coating system. The correlation between the theoretical and experimental CPVC's was either good or fair for the five systems studies. These results indicate that theoretically predicting CPVC's along with a statistically designed formulation procedure will yield an optimum coating region for the given pigment system. Keywords: Paints, Oil absorption.