Within the competing non-impact printing systems, ink jet printing has achieved a dominant position due to considerable advances in printer and colorant technology, and its capability of printing black and color on many surfaces at low cost. The continuing innovations in the field of dyes, pigments and inks for this true primary printing process are reflected by an increase to more than 640 patent applications in 1995. For recent industrial ink jet applications such as near-photographic, wide format and bar-code printing there is a growing demand for light fast colorants.In this paper, novel black disazo and tetrazo coppercomplex dyes are presented exhibiting improvements in light stability as compared to metal-free black azo dyes. The improved light fading resistance can be explained by enhanced dye aggregation. Furthermore, novel heavy metalfree black polyazo and polycyclic dyes for industrial ink jet applications have been developed on a pilot scale showing superior light fastness and bar code readability using infrared lasers. Optical as well as light and water fastness characteristics of the novel dyes are compared with commonly used heavy metal-free colorants.
W. Bauer, J. Geisenberger, H. Menzel, R. Pedrazzi, "Novel Black Colorants for Ink Jet Applications" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 99 - 102, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00024_1