Novel CNSL-based low viscosity epoxy curing agents for solvent-free high-performance protective coatings

 
To fulfill the increasing demand for low V.O.C. and high-performance protective coatings, a series of new solvent-free (SF) epoxy curing agents have been developed based on renewable cashew nutshell liquid (CNSL) technology with good handling and application properties. This paper will present the performance data of new SF curing agents in typical protective epoxy coatings formulations as well as flooring coatings. The performance test results reveal that those novel low viscosity curing agents can be easily formulated into SF or Ultra high solids epoxy primer systems, which exhibit fast cure at low temperatures, excellent adhesion to various substrates, and good corrosion resistance and good intercoat adhesion to polyurethane topcoat. Furthermore, common challenges faced by the removal of solvents, such as the balance between fast cure and long pot life, and effects of various diluents on compatibility and overall properties, are discussed.