Interaction of latex and clay in starch/latex bound pigmented coatings

A new method of improvement of the water resistance of starch in paper coating formulations is described. It depends upon a crosslinking mechanism between polymeric material and clay, producing a strong water- resistant network which can tolerate high starch levels. Swelling ratio studies and stress- strain curves of clay- loaded films are discussed, and a pigment crosslinking mechanism proposed consistent with these data. Paper coating formulations are illustrated. Data from production and printing trials are given to illustrate applications of this system to manufacture of high quality offset papers.