Recent developments in two-pack water-based epoxy coatings

In recent years new curing agent technology has been developed which allows water-based curing agents to be introduced into high performance coating, these are classified according to the type of epoxy resin used. Type I utilises low molecular weight, liquid epoxy resins and Type II pre-formed dispersions of higher molecular weight solid epoxy resins. The chemical composition of the binder of water-borne epoxy coatings plays a critical role in their performance properties, hence some of the structural properties of the amine hardeners will be reviewed. New curing agents will be discussed which demonstrate the versatility these products can offer to the coating formulator. Performance data of clear coats and anti-corrosive primers confirm the applicability of the new systems for the long term protection of steel and concrete surfaces.