This presentation will describe how two nano-structured inorganic material classes which are produced by flame processes have been crucial to the technical evolution of the toner industry during the past two decades: fumed metal oxides as external additives and carbon black as the essential pigment. Market forces driving this evolution and increasing additive diversity are the demand for high speed office printers and commercial digital presses and the need for low priced laser printers to make small office and home (SOHO) use affordable. Additionally, ecofriendly printers with reduced energy consumption and zero emissions require the development of toner with low fusing temperatures (low Tg) based on environmentally safe raw materials. Novel fumed silicon/titanium mixed oxides offer the positive tribo-charging benefits of titanium dioxide combined with the surface properties of silica. Acting as effective spacers that prevent re-agglomeration of low Tg toner, fumed sub-micron particles based on both silica and titania have distinct advantages over precipitated and sol-gel-derived materials, respectively. These include; low moisture, high purity, and the complete absence of internal porosity. For improved dispersibility and optimized toner surface coverage, de-agglomerated, chemical and mechanical structure-modified fumed metal oxides have been developed and will be discussed. Lastly, the paper will explore the impact of the ongoing EH&S (environmental, health & safety) discussion on external additives, carbon black and development trends toward safe external additives.
Paul Brandl, Yuki Amano, Akira Inoue, Masanobu Kaneeda, Steffen Hasenzahl, Monika Maier, Martin Moerters, Robert E. Johnson, "Evolution and Regulatory Impact of Fumed Inorganic Materials in Toners" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP24), 2008, pp 1 - 6, https://doi.org/10.2352/ISSN.2169-4451.2008.24.1.art00001_1