Generation alpha: Novel acylphosphine oxides for superior photoinitiation

 
Acylphosphine oxides, including BAPO (Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide) and TPO (2,4,6-Trimethylbenzoyldiphenylphosphine oxide) have been widely used as photoinitiators in UV-curable coatings, inks, and adhesives due to their efficient initiation and photobleaching properties. However, these materials bring some problems like the low solubility of BAPO and the recent regulatory bans due to potential health concerns of TPO. These issues have prompted the need for alternative photoinitiators using the advantages of acylphosphine oxide chemistry. We will discuss advancements in new photoinitiator design, such as improved reactivity, reduced toxicity, and enhanced compatibility with existing formulations (both 100% solids and waterborne systems). The comparative analysis of these photoinitiators highlights the progress and challenges in the search for effective and regulatory-compliant novel acylphosphine oxides.