Inkjet technology is finding utility in a variety of applications ranging from advertising, packaging, proofing, and the in-home printing of photographs. In many applications transparency of the inkjet coating is a critical parameter. Transparent media is widely used for graphic displays, window advertisements, and backlit applications. Ink receptive transparent coatings are also critical in glossy photographic media, especially transparency of the topcoat in multiple layer architectures. A transparent and glossy top layer is highly desirable and in most cases clarity correlates with gloss. It is generally accepted that a high degree of topcoat transparency translates to high printed color optical density.Silica nanoparticles are used in highly pigmented topcoats to create a porous structure, which traps the colored elements of the ink and lets the carrier liquid pass through to the underlying absorptive layer. In some cases nanoparticles are used in clear films to improve its mechanical properties.This paper describes two studies. Study I investigated the impact of the properties of silica nanoparticles on the clarity, gloss and printability of inkjet coating films. An experimental design was used to evaluate silica nanoparticles in combination with various binders. In Study II we explored the impact of acetoacetylated polyvinyl alcohols combined with different silicas on the transparency and gloss of the film.
Natalia V. Krupkin, Beate C. Stief, Michael R. Sestrick, Demetrius Michos, "Silica Nanoparticles: Design Considerations for Transparent and Glossy Inkjet Coatings" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP21), 2005, pp 442 - 444, https://doi.org/10.2352/ISSN.2169-4451.2005.21.1.art00029_2