Improvement in the light stability of ink jet printing images, by addition of salts in ink jet printing ink and the pressure medium

摘要

At least one of the following compounds is included on a surface layer of a print medium and in an inkjet ink formulation to be printed thereon: potassium iodide, sodium iodide, sodium thiosulfate, potassium thiosulfate, and sodium thiocyanate. The addition of at least one of these compounds to both the print medium and the inkjet ink can improve light fastness on the order of eight to thirteen times or more on porous glossy media. These additives are particularly effective with water-soluble dyes, including such dyes as Reactive Black 31 (Pacified) (RB31), Direct Blue 199 (DB199), Magenta 377 (M377), and Direct Yellow 132 (DY132).