Iodonium Salts Comprising Different Cations and Anions: Effect of Solubility in Coatings, Reactivity in NIR-Photopolymers and Toxicological Aspects

摘要

Photopolymers have received gained importance in coating sciences due to their multifunctional properties as chemical drying method resulting in a huge saving of energy. Beside the well established UV-technology, photopolymer systems using NIR radiation to initiate radical polymerization may be of interest for systems in which UV absorbers or yellow pigments are embedded. NIR-photopolymer systems have been known in the graphic industry for the use in lithographic plates for more than 15 years. Thus, we investigate the efficiency of some NIR-photoinitiator systems comprising as sensitizer the NIR-dye (1) and as electron acceptor an iodonium salt (2). Such a combination initiates well radical polymerization in some model coatings. One major focus was also the solubility of 1 and 2 in coatings of different polarity and viscosity. Particularly, the introduction of the [CF3SO_2NSO_2CF3]~- anion resulted in a giant solubility of the iodonium salt. Some of the iodonium salts were obtained as liquids, which were completely compatible with the resins used.