PRESERVING DYE IMAGES WITH A WATERFAST COLORLESS PLUORESCENT MATERIAL
Original Publication Date: 1992-Oct-31
Included in the Prior Art Database: 2004-Apr-06
Xerox Disclosure Journal
Images of dye based inks on plain and coated papers usually have poorer waterfastness than that of pigment based inks. This is because the dyes used in the inks are water soluble while the pigments are not. Due to good water solubility of the dyes their images on papers can be redissolved by water unless they can strongly react with paper or a paper coating additive to reduce dye water solubility. Most dye images have waterfastness problems. Information created with a nonwaterfast dye ink can be easily lost or distorted by water exposure. This creates a serious archival problem and it is especially true for an important document. Ink jet technology utilizing dye based inks may have this kind of problem. One way to improve the waterfastness of a dye image is to modify chemical structure of a dye so that it will either have reduced water solubility or can react with paper or an additive. Another way to preserve dye images or dye printed information from water damage is to use a colorless waterfast material whose image can be recognized easily under certain viewing illumination or conditions. The colorless nature of the chemical additive does not interfere with the original color of a dye and can be used in any color dye ink. Materials capable of preserving nonwaterfast dye images are disclosed.