Balancing Act: Principles of Design and Formulation for Waterborne Acrylic DTM Coatings

Abstract Achieving high performance with waterborne acrylic latex DTM coatings often requires a balancing act to be performed by both the polymer scientist designing the latex polymer and the coating scientist formulating the coating. A successful coating is defined by a set of critical properties while in the paint can, during application, and ultimately in its performance throughout its service life. It is often found, particularly with single component waterborne acrylic latex DTM coatings, that realizing certain combinations of key properties is difficult because the polymer feature or formulating technique that delivers one property leads to a decrease in another property. An example is producing a film with high gloss – one easy path to high film gloss is lowering the polymer molecular weight, but this usually also leads to a decrease in solvent resistance and exterior durability. Another is formulating a coating to low VOC – using a non-volatile plasticizer to aid in film coalescence is one path to low VOC, but film hardness is sacrificed. Thus, it is the task of the polymer chemist and coating formulator to understand certain principles employed in latex polymer design and coating formulation, and use those principles in finding an acceptable solution with the appropriate balance of properties. This paper will describe a variety of the guiding principles used in designing and formulating waterborne acrylic DTM coatings, as well as some of the exceptional solutions that have been devised to break free from the delicate balancing act and the restrictions it sometimes places on achieving high performance. The challenges, principles and creative solutions will be demonstrated with performance data from waterborne acrylic DTM coatings developed over the course of several decades.