Читать книгу Additives for Waterborne Coatings - et al. - Страница 79

Defoamers are required in practically all water-borne coating formulations. Important criteria in choosing the right defoamer are the types of binder and cosolvent.

The use of external emulsifiers is frequently necessary for stabilising water-borne binders. Depending on the binder chemistry, there are large differences between the type and amount of emulsifiers used. The hydrophobicity of the defoamer thus has to suit the binder chemistry and the emulsifiers to achieve efficient defoaming. Paint manufacturers only rarely have detailed knowledge of the composition of a binder, but general recommendations for choosing defoamers are possible based on experience.