Water based inks containing near infrared fluorophores

摘要

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%.