Composite titania-calcined kaolin opacifying pigments and method for making and using same

摘要

Novel titania-calcined kaolin composite pigments wherein structuring and adhesion of titania and calcined kaolin particles is achieved by use of a cationic polyelectrolyte. Methods for compositing titania and calcined kaolin pigments which feature the presence of at least one polyanionic dispersant (such as sodium polyacrylate, sodium silicate, sodium condensed phosphate or mixtures thereof) in the pigment slurry into which cationic polyelectrolyte is introduced and the use of strongly alkaline pH (e.g., above 9).