Thermal / Blue light Induced Crosslinking of Acrylic Coatings with Diazo Compounds.

The thermal curing of industrial coatings (e.g., car painting, metal coil coatings) is accompanied by a substantial energy consumption due to the intrinsically high temperatures required during the curing process. Therefore, the development of new photochemical curing processes-preferably using visible light-is in high demand. In this work, we describe new diazo-based crosslinkers that can be used to photocure acrylic coatings using blue light. We demonstrate that the structure of the tethered diazo compounds influences the crosslinking efficiency, finding that side reactions are suppressed upon engineering greater molecular flexibility. Importantly, we show that these diazo compounds can be employed as either thermal or photochemical crosslinkers, exhibiting identical crosslinking performances. The performance of diazo-crosslinked coatings was evaluated to reveal excellent water resistance and demonstrably similar material properties to UV-cured acrylates. These studies pave the way for further usage of diazo-functionalized crosslinkers in the curing of paints and coatings. This article is protected by copyright. All rights reserved.