Externally-added charge control agents (EA-CCA) were prepared by means of a coacervation process. Spherical silica particles of 100 nm average diameter were coated with two kinds of charge control agents (CCAs); one is a polymer type P-1 and the other is a low molecular weight type P-2. Both of them make a remarkable contribution to toner charge. In a concentration range from 1 to 1×103 ppm of CCA on toner, toner charge increased. From the relationship between the amount of EA-CCA in the toner and the tribocharge, P-2 was found more effective than P-1. It is estimated that 0.7 % of P-1 repeating units and 1.2 % of P-2 molecules contribute to toner charge, respectively.Calculation of the surface coverage of P-2 on spherical silica particles shows that the efficient concentration region of charge agreed with the surface coverage. The P-2 concentration was 50 ppm based on toner. This means that the CCA molecule has great effect on tribocharge in small concentration.
Koichi Tsunemi, Atsushi Suka, Takashi Iimura, Toshihiko Oguchi, Norihisa Kobayashi, "Toner Charge Control with Externally-Added CCA Particles" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP26), 2010, pp 81 - 84, https://doi.org/10.2352/ISSN.2169-4451.2010.26.1.art00022_1