Environmental concern was the main reason to develop other systems like powder
coatings, high-solids, radiation-curable and waterborne alternatives to mature
solventborne (S/B) coatings. The present paper is focused on radiation-curable
and waterborne coatings, so high-solids and powder coatings will not be
discussed here.
In the beginning of the 1960s, waterborne systems (W/B) based on polymer
dispersions, mainly polyvinyl acetate (PVA) homopolymers
or copolymers, were used for interior and exterior decorative paints.
Waterborne technology allowed the reduction of the organic solvent content in
the paint formulation but, especially at the beginning, some properties of W/B
products were inferior to the properties of solventborne types (Table 1). The
waterborne market was developing very fast, and polymer dispersions of different
chemistry types were created and introduced to various waterborne coating and
cementitious systems.4 Acrylic copolymers are
used very commonly because of their versatility and tailor-made properties
depending on the monomer content and polymerization technique.5