Résumé : |
Over the years, the use of conventional organic solvent-based paints has come under increasing environmental pressure. More recently, the toxicity of these solvents to humans has also become an area of concern. Prolonged exposure to these solvents, especially by professional painters and those working in the paint manufacturing industry, has been found to cause the organo-psycho syndrome (OPS). In addition, most organic solvents are flammable, and come from oil sources, which may become depleted at some time in the future. These concerns have driven the world coatings industry to develop water-borne technology for application in low VOC paint systems. For many years now, water-borne dispersions have been used for decorative coatings where they are slowly replacing conventional solvent-borne alkyd systems. Whereas in some other application areas, the advantageous fast drying and superior properties of water-borne dispersions has led to rapid replacement of solvent-based coatings, this same fast drying has limited the success in decorative coating applications. The "open time" or "wet edge time" of water-borne coatings is generally regarded as being too short. |