Effects of Selected Pigments on the Properties of Silicone Resin-Based Paints

The purpose of this research was to evaluate the impact of selected pigments on the performance of waterborne emulsion paint. Each pigment was incorporated into the paint at 5% w/w. Density and viscosity measurements as well as the rub-out test were used to test the wet state properties of the colored paint. Wet-scrub, adhesion-to-substrate, water-uptake, vapor-permeability, UV-aging, and other tests were conducted to evaluate effects of the pigments on the dried paint. Bohemian green earth pigment was found to have the most positive effect, as it improved the water resistance of the paint without changing its rheological properties. Therefore, this pigment was selected for further studies, in which the pigment was included as part of the paint formula rather than as a post-additive. The results were satisfactory, confirming the compatibility of the pigment with the formula. However, a slight change in the rheological profile of the paint was observed during tests on a rotational rheometer. This research shows the need for intensive quality control measures while testing alternative formulations, to both enable early detection of negative effects and identify possible improvements.