The impact of insoluble cellulose fibrills on the rheology of waterbased acrylic satin paint upon tinting

 
Associative thickeners are commonly used to thicken water based coatings. Their action is based on the hydrophobic interaction between the hydrophobic polymer groups as well as with the surface of the binder latex particles. It is commonly known, that associative thickener based formulations are prone to viscosity loss upon tinting due to the surfactants present in the tinting systems. In this work, the effect of insoluble cellulose fibrils on the prevention of viscosity loss on tinting was studied with a deep tone base, formulated with hydrophobically modified polyurethane associative thickener (HEUR) together with a non-associative cellulose fibril thickener. The formulations were evaluated in terms of viscosity, syneresis, sag resistance, flow and levelling, contrast ratio, gloss, color acceptance and float as well as scrub and block resistance. We will demonstrate how cellulose fibrils can improve resistance to the viscosity loss and sag resistance without sacrificing the flow properties of the coating.