The ink jet printing system is becoming popular in the market. There are two varieties of ink in the conventional ink jet ink system. One is water-soluble dye based ink and the other is pigmented ink. Dye-based ink has clear color and high reliability, however it is suffering from insufficiency of waterfastness and lightfastness. Pigmented ink has advantages in waterfast and lightfast, but it has limitation on ink stability, clear color and rub resistance. Therefore, new inks have been required to overcome these problems.We have developed new emulsion colorant in order to solve these problems. The colorant is water based polymer emulsion containing water insoluble dye or pigment. When using polymer emulsion containig water insoluble dye, prints show clear color, waterfastness, and rub resistance properties. And when using polymer emulsion containing pigment, prints show waterfastness, lightfastness, and rub resistance properties. Emulsion-based ink would be a technological breakthrough to improve the durability of aqueous ink jet system.
T. Tsutsumi, M. Sawada, Y. Nakano, "Polymer Emulsion-Based Ink Jet Colorant and Ink" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP15), 1999, pp 133 - 136, https://doi.org/10.2352/ISSN.2169-4451.1999.15.1.art00035_1