Synthesis of Amino Acid-derived Curing Reagents Containing a Disulfide Bond and Their Application to Anionic UV Curing Materials

Anionic UV curing has been applied for many kinds of industrial resins, because it overcomes technical problems in conventional radical and cationic UV curing. In this study, a cystine-based latent curing reagent was designed, and synthesized from l- and d-cysteine. The reagents showed not only good solubility toward organic media, but also good thermal decomposition behavior in the presence of basic species. Using them with a photo-base generator and an epoxy resin having a disulfide bond, UV-cured films of B-to-3B grade of pencil-hardness were fabricated successfully, after 10 J/cm2 of 365 nm-light irradiation and subsequent heating at 120-160°C for 30 min. Furthermore, two glass substrates were adhered by using this anionic UV curing system, and 1.6-3.7 MPa of shear stress was recorded in the photo-adhesion and re-adhesion experiments.