Formulating High-Performance Waterborne Acrylic Direct-to-Metal Coatings Under 25 g/L VOC

By Kathleen Auld, Matthew Padaon, Leo Procopio

Waterborne direct-to-metal (DTM) coatings for the protection of steel infrastructure are currently in demand because they allow the end user to reduce volatile organic compound (VOC) emissions, promote higher safety standards, and take advantage of sustainable technology. Raw material and formulation modifications necessary to reach low-VOC content must be carefully designed, as typical approaches often lead to trade-offs in properties such as block, corrosion, and dirt pickup resistance (DPUR).

Today, waterborne acrylic DTM coatings at 50 g/L VOC with a good balance of properties are available, but a demand for even lower VOC content exists. This article describes a new acrylic resin for formulating DTM coatings at a VOC level further reduced to less than 25 g/L, while also demonstrating the highest standards of exterior durability and corrosion resistance. A comparison to currently available low-VOC resins and DTM coatings will be described to highlight the advantages of the new binder.