Due to the higher polymer content of the paint film, there are greater performance demands for semi-gloss paints than for flat paints. These demands include gloss retention, block resistance and adhesion over previously painted glossy substrates. For exterior paints that are subjected to solar warming, block resistance performance is especially critical.
As the regulations drive allowable VOC levels in paint formulations lower, these performance properties can become more difficult to achieve. In order to achieve low-VOC coatings, the paint formulator either uses latex with a low glass transition temperature (Tg), or one with high amounts of non-volatile film formers. Unfortunately, both solutions can lead to poor block resistance, poor early water resistance and poor dirt resistance.
This problem can be overcome by using
Acronal Optive® 130 from BASF, which is a multiphase latex with soft
and hard phases on each latex particle. The soft phase aids in continuous film
formation, whereas the hard phase helps to create outstanding block and dirt
over six years of exposure, Acronal Optive 130 has proven to be the leading
choice for low- to zero-VOC all-acrylic paints. Results listed in Figure 1 are
based on a compilation of three years of southern exposure at a 45° angle in Florida, North
Carolina and Pennsylvania.
For more information, contact Kent Clow at firstname.lastname@example.org.