TY - JOUR A1 - Brömme, T. A1 - Schmitz, C. A1 - Oprych, D. A1 - Wenda, A. A1 - Strehmel, V. A1 - Grabolle, Markus A1 - Resch-Genger, Ute A1 - Ernst, S. A1 - Reiner, K. A1 - Keil, D. A1 - Lüs, P. A1 - Baumann, H. A1 - Strehmel, B. T1 - Digital imaging of lithographic materials by radical photopolymerization and photonic baking with NIR diode lasers JF - Chemical engineering & technology N2 - Photo-initiated cross-linking of multifunctional acrylic esters in polymeric binders was investigated based on digital imaging using the Computer-to-Plate (CtP) technology applying laser exposure in the near-infrared (NIR). Generation of initiating radicals occurs by electron transfer from the excited state of the NIR-sensitizer to the radical generator, an onium salt. Iodonium salts derived from several borates and those with the bis(trifluoromethylsulfonyl)imide anion resulted in lithographic materials with high sensitivity. Photo-induced electron transfer plays a major function to generate initiating radicals by a sensitized mechanism but thermal events also influence sensitivity of the coating. Internal conversion was the major deactivation pathway while a certain fraction of NIR-dye fluorescence was also available. A line shape focused laser system with emission in the NIR was successfully used to bake the materials. KW - Iodonium KW - Near-infrared laser KW - Photonic baking KW - Photophysics KW - Photopolymer PY - 2016 DO - https://doi.org/10.1002/ceat.201500453 SN - 0930-7516 SN - 1521-4125 VL - 39 IS - 1 SP - 13 EP - 25 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35303 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -