Used primarily as a photoinitiator in UV-curable systems, this compound plays a key role in free-radical polymerization upon exposure to light. It is especially effective in clear coatings, inks, and adhesives where deep cure and low yellowing are required. Its bulky t-butyl group enhances solubility in non-polar matrices and improves shelf stability. Commonly found in formulations requiring high reactivity under medium-pressure mercury lamps, it enables fast curing in printing and electronic coating applications. Additionally, its sulfonate ester structure contributes to good thermal stability prior to activation, making it suitable for precision curing processes.