Adhäsionsverhalten zwischen bewitterten 2K-EP-Beschichtungen und 2K-PUR-Beschichtungen - Einfluss der Bewitterung

Investigation of the adhesion behaviour between exposed 2K-EP coatings and following 2K-PUR coatings - influence of weathering.

During weathering of coatings of aromatic epoxy resins, for corrosion protection usually crosslinked by amine based hardeners, the chemical structure of surface layers might be changed. Therefore the following coating layers can suffer from bad adhesion. The impairment of adhesion between intermediate coat and top coat depends on weathering parameters. So the testing methods, including outdoor exposure, show often insufficient reproducibility. Important parameters are the starting time and duration of weathering.
In this paper investigations of the adhesion between several coatings of epoxy resins and top coats, consisting of 2K-polyurethane are described. Here the special topic is the testing of adhesion between intermediate coat and top coat.