METHOD FOR PRODUCING RHEOLOGICAL ADDITIVES AND COATING COMPOSITIONS INCORPORATING SAME

摘要

A process for preparing an additive-thickened water-based coating formulation exhibiting improved pourability, hiding characteristics, and thickening in relation to the quantities of rheological additive in the coating formulation. The process involves preparing an aqueous smectite clay slurry having 3 to 30 % clay by weight; bead milling the aqueous smectite slurry with a grinding media at an energy input in the range of from about 44 of 146 kw-hr/metric ton of dry clay; and incorporating the milled smectite slurry as a rheological additive in a water-based coating formulation in an amount in the range of from about 6 to 120 g per liter of formulation.