Understanding light- and storage stability is of utmost importance in inkjet printing. In this paper we present investigations of light-induced kinetics of dye degradation. Magenta black and cyan dyes are irradiated on typical glossy and matt media using a Xenon lamp and the decrease of remission intensity with irradiation time is recorded using UV-Vis spectroscopy. Most dye kinetics can be described as 1st order reaction at least in the beginning of the reaction. From temperature dependence of 1st order kinetics we are able to determine activation energies for the decay process allowing us a detailed media-dependent comparison of kinetic behaviour. Furthermore an analysis of UV-Vis spectra show that not only one single degradation channel is responsible for light fading processes.In order to define the contribution of oxidative non-light induced processes UV-Vis data of dark storage under oxidative atmosphere are compared in shape and intensity allowing a separation of light and oxidative decay channels. For most ink-paper combinations a superposition of light-induced and oxidative mechanisms are likely. Using activation energies as parameter for dye-paper stability also the influence of room humidity on stability of inkjet prints can be estimated.
U. De Rossi, U. Litz, C. Blendl, "Activation Energy of Dye Degradation Processes on Different Inkjet Papers" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP19), 2003, pp 450 - 453, https://doi.org/10.2352/ISSN.2169-4451.2003.19.1.art00107_1