On-Demand Curing of 2K-PUR with Photo-Latent Catalysts

Energy savings by the introduction of more efficient curing processes that use less energy is a constant theme for the coatings industry, and has high emphasis in automotive applications. Taking the case of two-component polyurethane (2K-PUR) coatings, the use of conventional catalysts, e.g. dibutyltindilaurate (DBTL), to accelerate the cross-linking reaction is limited by the balance between fast and efficient curing and sufficient pot-life for handling. Thus, the dosage of such catalysts is often sub-optimal regarding the curing step, and heat is used to shorten the curing time as compensation for using too little catalyst.