UV screening clear coats based on encapsulated CeO2 hybrid latexes

Abstract

CeO₂ nanoparticles have been successfully incorporated into acrylic latex particles with an excellent homogeneous distribution (mostly one inorganic particle per polymer particle) and limited aggregation (inorganic nanoparticles predominantly in the 17–26 nm range, when the original cerium oxide dispersion had a volume average diameter of 8 nm). The hydrophobicity and wettability of the inorganic nanoparticles with the monomer mixture and the process used, semibatch emulsion polymerization on a seed produced by miniemulsion polymerization containing the whole load of the metal oxide, were the key aspects to achieve this morphology for the first time at industrially relevant solids content (40 wt%). Furthermore, the transparency and the substantially enhanced UV-Vis absorbance capacity make those hybrid acrylic/CeO₂ dispersions excellent candidates for a large number of applications including clear coatings and cosmetics.