Novel de-aerators for airless spray applied water-based coatings

摘要

Identifying, the best defoamers or de-aerators for water-based coatings remains a challenge for coatings formula-tors. The selection process often takes place only after the main components of the formulation have been selected and foaming issues have been identified. Time pressures often make the search for a solution even more challenging. Finding the right defoamer or de-aerator is a question of finding the right balance between two opposite properties: compatibility of the defoamer and its defoaming efficacy. On one hand, a compatible defoamer is easy to incorporate and does not create surface defects or stability issues; but it can be less efficient at defoaming, especially in highly filled or viscous systems. On the other hand, an incompatible defoamer, by its very nature, will have more affinity for the air/liquid interface and will be active at the air bubble surface facilitating foam breaking. The disadvantage is that this can create compatibility issues leading to poor coating aesthetics.