Polymide-based polyurethane water-borne dispersions for direct-to-metal applications

 
In the past few years Lubrizol developed a polyamide-polyurethane waterborne dispersion technology and we showed that these new materials have a unique balance of properties, good chemical resistance, higher hardness and many other advantageous properties. Several high-performance products have already been commercialized using the technology and we continue to explore the commercial feasibility of these materials, recently focusing on metal substrates and direct-to-metal applications. Conventional waterborne urethane dispersions perform poorly in direct-to-metal applications due to film formation issues and the hydrophilic/acidic nature of the dispersants. We found that polyamide-based urethane dispersions had significantly higher corrosion resistance than traditional waterborne urethanes, which can be attributed to the hydrolytic stability of the polyamide segment and its good adhesion to metal substrates. Polyamide-based urethane dispersions can provide single coat solutions with both corrosion resistance and protective features.