Waterborne acrylic and epoxy systems have both grown in popularity and are now widely used by industrial metal coating applicators, in particular for primers. Waterborne acrylic systems are fast in early hardness development, good at UV resistance and easy to handle but have limited corrosion protection. Waterborne epoxy systems on the other hand offer good corrosion resistance and flexibility but with slow early hardness development, limited UV resistance and very limited pot life.
This paper will illustrate how the latest developments in acrylic –epoxy cross linking systems make it now possible for metal primer applications to provide the benefits of a long pot life, fast drying time and fast early hardness development with sufficient flexibility. This while maintaining the corrosion protection performance of a classical waterborne epoxy. The acrylic-epoxy cross linking technology also provides cost benefits versus a traditional waterborne epoxy system and does not require the use of an amine hardener making the coating application easier. The good UV resistance of the acrylic-epoxy cross linking systems also makes it an interesting system for certain topcoat applications.