Study on Relation Between Dirt Pick-up Tendency from Outdoor Exposure and Paint Film Physical Properties

Abstract

We have executed the outdoor exposure of various kinds of exterior decorative finish coatings, and the relation between the paint film physical properties and dirt pick-up tendency from the outdoor exposure has been investigated. The higher the surface hardness was and the lower the elongation ratio by tensile test was, the paint film without function of generating hydrophilic property showed better dirt pick-up resistance. On the other hand, dirt pick-up resistance of the paint film that has function of generating hydrophilic property did not show much correlation with those properties above, but was depending on only water contact angle on the paint film surface. This time, we will report new findings obtained from the continued outdoor exposure and the difference of dirt pick-up tendency by starting season of outdoor exposure.