There are a number of basic ingredients necessary in formulating waterborne architectural paints - the latex resin (binder), pigments, coalescent solvents, thickeners and the additives. Among these additives are surfactants that offer dispersion stability, provide needed wetting for substrate application, and enhance characteristics such as gloss and color development. This paper addresses the effects of surfactants - phosphate ester-based surfactants in particular - in semigloss waterborne architectural formulations.
Surfactants (derived from 'surface active agents') are chemical substances that, when present at low concentrations in a system, have the property of migrating and being absorbed on the interface, which is typically a water-oil or water-air type. The presence of these species in the boundary layer alters its interfacial free energies. Surfactants must be soluble in at least one of the phases in the system, and the substance must aggregate into micelles at certain concentrations. Typically, one of these phases involves water; therefore, the surfactant molecule must be amphiphillic - contain a hydrophobic tail and a hydrophilic head.