UVA prevent the degradation of both coatings and
substrates by filtering out the harmful UV radiation
before subsequent photochemical reactions can take
place. In the case of UVA one has to differentiatebetween inorganic and organic products. Today, the
most widely used organic UVA for medium-to-high
quality coating applications are 2-(2-hydroxyphenyl)-
benzotriazole (BTZ) and 2-hydroxyphenyl-s-triazine
(HPT) derivatives. The latest class shows a great
variety of advantages in many different applications
and cure conditions and can be used in high-performance
applications or where BTZ cannot be used.3
Inorganic products are ideally nano particulate materials,
the so-called mineral screeners (MS) comprised
of titanium dioxide (TiO2), zinc oxide (ZnO), or
cerium oxide (CeO2).