The monomer known as VeoVa vinyl ester, which featured at the 2015 European Coatings Show in Nuremberg, Germany, has been shown in exterior paint testing to help resist dirt pick-up and water whitening when formulated into acrylic latices, offering manufacturers an opportunity to differentiate.
In one recent study comparing exterior paints containing high quality all-acrylic binders, styrene/acrylic binders, or acrylic emulsions co-polymerized with Hexion’s VeoVa 10 monomer– commonly referred to as Veocryl – the Veocryl latex paints exhibited equal or better dirt pick-up resistance than those without Veocryl in natural outdoor exposures. The study also highlighted superior resistance to UV exposure as measured by the coating yellowing index, as well as resistance to fungi.
“We evaluated paints using these various binder systems in several locations in Asia, including sites selected for their severe climate/pollution conditions,” said Egbert Klaassen, global managing director, Versatics Business Unit at Hexion. “Dirt pick-up was determined by measuring the delta L of the coatings over a two-year exposure period. The Veocryl latices, because of their highly-branched aliphatic structure, exhibited better weathering over all-acrylic systems.”
Hexion also presented new test results on water-whitening performance for VeoVa vinyl ester-based exterior paints at the European Coatings Show. Paint manufacturers prefer that dried latex film not turn white when in contact with water, as whitening implies inferior water resistance and poor durability. New testing has shown that adding small quantities of VeoVa 10 vinyl ester, the most hydrophobic monomer on the market, into acrylate systems produces latices with superior water-whitening resistance.
“Formulating effective, water-whitening resistant latex requires careful control of many factors including surfactants, silanes and functional monomers like hexanediol diacrylate (HDDA),” added Klaassen, “But when done correctly and enhanced with VeoVa monomers, water-whitening resistance can be remarkably improved.”