Use of starch dispersions as binder in coating compositions and process for preparing the starch dispersions

摘要

The invention is directed to coating compositions comprising a pigment and starch dispersion of discrete crosslinked starch particles in an aqueous liquid. The dispersion may be used as coating color for paper. A preferred process of preparing said dispersion of starch particles comprises (a) obtaining a mixture of starch and an aqueous liquid; (b) processing the mixture using shear forces in the presence of a crosslinker in an extruder; and (c) injecting a hydroxylic liquid into the extruder and dispersing the mixture inside the extruder or outside the extruder or both inside and outside the extruder to obtain the dispersion.