Solutions to imrove the application properties of water-based paints meeting the latest eco-label criteria

 
The latest version of the European Eco-label (EU Flower) toughens the criteria, particularly for volatile organic compounds (VOCs), by mentioning for the first time the semi-volatile organic compounds (SVOCs), residual monomers and preservatives (biocides). The risk incurred is to reduce the paints' performance levels in terms of film formation, adhesion and preservation properties. Fewer of VOCs, for example, can limit the leveling, the flow and the open time of a paint, as these properties are easily obtained using glycol derivatives. A lower level of residual monomers and preservatives make it more difficult to stabilize the paints with regards to the development of microorganisms. Hence the need to reduce the use of ingredients that have a high level of microbiological sensitivity such as cellulosic thickeners (HEC). The alternative solutions must combine the technical advantages traditionally provided by HEC-type thickeners, in particular the open time, without adopting the defects (microbiological sensitivity, limited application properties). The performance of a new class of thickener is discussed and original approaches are proposed to measure the open time by rheological and optical measurements.