Exterior coatings can be long lasting, cost efficient and environmentally advanced
Write:
Raphaella [2011-05-20]
If you walk around cities in China after it has rained, you may notice obvious stains on the exterior walls of many buildings. The reason, in most cases, is that traditional exterior emulsion coatings are not smooth, nor continuous, which allow pollutants to gather on the surface and penetrate into the coatings - leaving unsightly stains. The serviceable life of these coatings are significantly reduced. Rohm and Haas has introduced a solution to this problem.
In China, paint manufacturers normally use high glass transition temperature (Tg) polymers to enhance the relative hardness of the coating to resist dirt pick-up. These coatings require high levels of expensive, solvent based, film-forming additives. When manufacturers try to save cost by reducing these additives, the films micro-crack and are easily stained.