Abstract: This invention pertains to aqueous-based ink formulations for inkjet printing of invisible markings on the surface of articles for identification, authentication, sorting, etc. The ink formulations contain at least one near infrared monomeric (as opposed to copolymerized) dye which has been previously dispersed or dissolved in water, glycols, aliphatic alcohols, and are useful for printing by both Continuous inkjet (CIJ) and Drop-on-demand (DOD) methods. This invention also demonstrates the enhanced ability to formulate said inkjet ink formulations when a small amount of water-dissipatible sulfopolyester/amide is added. Also, melt extrusion blending is demonstrated to be an alternative manufacturing process for premixing current Eastman ClirCode™ copolymerizable dyes with the water-dissipatible sulfopolyesters without need for more expensive polymer process manufacturing steps.

Abstract: The present invention relates to thermal transfer ribbons comprising a ribbon backing element and at least one printing media layer comprising at least one near infrared fluorescent compound in a concentration which provides detectable fluorescence without imparting color to a mark made from said printing media layer. Methods for printing marks containing said at least one near infrared fluorescent compounds via thermal transfer and methods for reading said marks are also disclosed.

Abstract: An organic solvent based polyester ink formulation having a fluorescing compound therein is suitable for ink jet printing applications. The ink is useful for producing invisible printing/markings on the surface of a variety of materials for identification, authentication, sorting, etc. Suitable printing substrates include porous and non-porous materials such as plastic, film, sheeting, fabric, paper, high gloss paper; metal, foils, plates; rubber; glass; cellophane; wood; and the like. The ink formulation contains at least one organic soluble polyester, having at least one near infrared fluorophore copolymerized therein, dissolved in an organic solvent. Suitable organic solvents include a C.sub.3 -C.sub.6 carbon ketone, a C.sub.3 -C.sub.6 carbon organic ester, a C.sub.1 -C.sub.3 carbon alcohol, or a combination thereof. In a preferred embodiment, the polyester containing the copolymerized near infrared fluorophore is dissolved in a solvent comprising a C.sub.3 -C.sub.6 carbon ketone and a C.sub.1 -C.sub.

Abstract: The present invention provides inks which contain a near infrared fluorophoric compound incorporated into a water-dissipatible polyester backbone. The inks of the present invention are preferably colorless or "invisible" but could be made slightly colored if desirable. Specifically, the inks of the present invention comprise:A. between about 1 and 10 weight percent of at least one water-dissipatable polyester having from about 0.1 ppm by weight to about 10% by weight of a thermally stable near infrared fluorophoric compound copolymerized therein;B. between about 5 and 75 weight percent of at least aliphatic humectant;C. between about 0 and 15 weight percent of at least one lower aliphatic alcohol of no more than 3 carbon atoms;D. water and optionally up to about 2 weight percent of one or more additives;wherein the weight percentages of components A-D equal 100%.