UV curing systems based on cationic processes are very significant because the systems have several advantages, compared to the radical processes. Photoacid generators (PAGs) are essential for the cationic UV curing system including epoxides and vinyl ethers. Although many types of PAGs have been developed, most of them are not sensitive to i-line (365 nm) of a high-pressure mercury lamp. In this study, non-ionic and ionic PAGs that are thermally stable and highly sensitive to i-line were designed and synthesized. Furthermore, photochemistry of these PAGs and their applications to photocrosslinking systems based on epoxy-containing polymers and oligomers were studied.

Masamitsu Shirai received his Ph.D. degree from Osaka Prefecture University (OPU) in 1978. After working as an assistant professor and then an associate professor at OPU, he was promoted to a professor of applied chemistry at OPU in 1997. He spent his early career as a postdoctoral fellow (1978-1979) at the State University of New York at Syracuse, New York, USA. His research interests include synthesis and applications of photosensitive polymeric materials, especially photoresists, photoacid generators, photobase generators, UV curing materials, and photodegradation and stabilization mechanisms of polymeric materials. He has published more than 250 research papers including reviews and books.