Chromate-Free Silane-Containing Primer Technology

With the use of silane-containing primer technology the chromate in the conversion coating and the primer as well as the volatile organic compounds of the primer can be eliminated. This primer, which is based on water-dispersed resins, crosslinkers and silanes, is applied onto the substrate directly after alkaline cleaning. Because of the organofunctional silane contained in the primer, its adhesion to the substrate is maintained even without a pretreatment layer. The corrosion resistance of the primer is assured by incorporating chromate-free corrosion-inhibiting pigments into the formulation. For industrial applications, primers need to be dividable into packs and should be compatible for many different coating systems. This paper reports on two phases of investigation of an epoxy-acrylate primer. In the first phase this primer is divided into packs and its performance and chemistry are studied in an aircraft coating system. In the second phase the same primer and its improved version are studied in an automotive coating system and are compared with an automotive reference coating system. Our study reveals that the primer is dividable into packs and the performance of the primer is promising in both applications.