Associative thickeners are an important tool to impart rheology to waterborne latex coatings. Unfortunately, one of the biggest drawbacks of associative thickeners has been the phenomenon known as "viscosity drop": the viscosity instability with the addition of colorants. It has proven a difficult problem to solve and has added increased formulation complexity while sometimes resulting in poor coating properties.Architectural universal colorants have been around for more than half a century and unlike paints have not been subject to major environmental legislation. Their technology has not been updated in many decades. Due to their traditional surfactant package and generous use of glycols they cause problems with newer paint technologies such as associative thickeners. By formulating colorants on different dispersant technology the "viscosity drop" can be greatly reduced.
展开▼
