How to Design Novel Photoinitiators for Blue Light
This paper shows some examples of the construction of new photoinitiators for blue light based on different chromophores: naphthalimides, naphthalic anhydrides, benzo-isoquinolinones, benzophenones, indanediones, chalcones, chromones, and perylenes. Theoretical calculations allow the molecular orbitals to be efficiently combined to shift the absorption properties of classical photoinitiators to longer wavelength. Moreover, suitable combinations of these original photoinitiators with various additives ensure excellent initiation of the free-radical polymerization of methacrylate monomers both in laminate and under air. Many additives were also studied in these multi-component photoinitating systems to drastically improve their initiating ability. The stability of photoinitiators in formulations as well as their bleaching properties are also important parameters to characterize for the end user.