Photolatent Tertiary Amines – A New Technology Platform for Radiation Curing

Abstract

The lack of efficient photolatent amine catalysts has so far prevented the use of base-catalyzed formulations in radiation curing. The development of two new photocatalysts which release 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or tertiary amines upon irradiation opens new opportunities for this technology. Photolatent DBN is used for crosslinking processes where strong bases are required as catalyst, such as coatings crosslinked via the Michael addition reaction, while a tertiary amine efficiently catalyzes reactions involving more acidic compounds. A UV-A curable car refinish clear lacquer has been developed as a first example of a commercial formulation using a photolatent amine as catalyst.