Next-Generation Rheology Modifier Technology

By John J. Rabasco, Tara Lyn Conley, David Fasano, Daniel Saucy

In the architectural paint market, attention has focused on driving down volatile organic compounds (VOCs) while enhancing application performance for the do-it-yourself (DIY) market. This segment seeks products offering easy application, long-lasting performance, and excellent hiding, with a minimum number of coats. Ultimately, the desired goal is an applicator experience and performance result that can be differentiated in the market when evaluated by consumer market rating organizations.

From a marketing perspective, how a paint feels when it is stirred, poured, and applied to the wall contributes to a unique end-user experience that helps to define the benefits of one brand over another. Rheology plays a key role in this area, directly affecting the in-can feel, as well as film thickness and finished smoothness of the final coating. An ideal rheology package is one that optimizes both sag resistance and flow across a range of shear. This is an ongoing formulator challenge due to the inherent characteristics of commonly used cellulosic thickeners and conventional hydrophobically modified ethylene oxide urethane (HEUR) rheology modifiers.

Cellulosics offer excellent sag resistance, but they lack the properties needed to optimize flow. Conventional HEURs, by contrast, offer excellent flow, but often lack sufficient sag resistance. In typical paint formulations, optimizing one property means sacrificing the other to some degree. To address this performance conflict, a new category of HEUR thickeners has been developed that optimizes both sag resistance and flow, a combination heretofore unseen in commercial rheology modifiers.