Development of Photobase Generators Liberating Radicals as well as Bases and Their Application to Hardcoating Materials

Abstract

Most of the photosensitive materials are based on photoradical and/or photocationic polymerization, because many photoradical and photoacid generators, monomers, and oligomers are commercially available. Although photosensitive materials based on basecatalyzed reactions have merit in preventing erosion of metallic substrates, Photobase generators (PBGs) generally have lower quantum yields when compared to photoradical initiators (PIs) and photoacid generators (PAGs). We report here novel PBGs based on a benzoin structure. This PBG can liberate radicals as well as bases with high efficiency by iline irradiation, so that a homogeneous organic-inorganic hybrid film can be formed. As a result, the hardcoating materials based on the organic-inorganic hybrid show high pencilhardness (4H), transparency, and scratch resistance compared to coating materials using conventional PIs and PBGs.