Low VOC Autocatalytic Anti-Corrosion Primers

Anti-corrosion coating systems typically rely on viscous two-component systems with high VOC content. Autocatalytic, moisture-cure polyurethanes (MC PU) offer a unique approach to develop one-component coatings, which are easier to apply compared to 2k systems and usually can be formulated with lower VOC content. However, highly filled MC PU primers are prone to bubbling and lack flexibility. Recent developments in autocatalytic MC PU will be discussed, especifically on how they enable the development of low VOC primers and minimize primer defects such as mud-cracking and bubble formation. Additionally, coating compatibility, recoat time and effects on interlayer adhesion will be addressed.