The use of calcined clay as part replacement of titanium dioxide in latex paint formulations

Titanium dioxide, TiO2, being a prime pigment, has been used extensively in the paint industry. The growing demand and the increasing cost of TiO2 has driven the attention of paint technologists to search for other alternatives. There has been continuous effort to replace part of the TiO2 with a fine particle size extenders in paint formulations. A detailed study has been undertaken to replace TiO2 pigment by various percentages of calcined clays in two latex paint formulations. Properties such as thixotropy, hiding power, light fastness, film brightness, scrub resistance, and weather resistance have been determined to establish the optimum use of calcined clays in the paint formulation. Thixotropy, one of the important properties of latex paints, has been studied with the help of thixotropic loop area method. The viscosity data has also been analyzed by Casson's equation. It has been found that the calcined clays can replace up to 20% TiO2 in paint formulations without having any adverse effect on their properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1029 -1036, 2000