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US 6,672,718 B1Granted
Aqueous latent image printing method and aqueous latent image printing ink for use therewith
AssigneeLaser Lock Technologies, Inc.
InventorTerry Stovold
Life of this patent
Estimating the term…
Abstract
The present invention relates to an aqueous latent image printing method which includes applying to a substrate, such as paper, a latent image ink composition, via an ink jet printer. The latent image is then activated to render it visible, by application of an activator.
Claims7
A method for covertly communicating information, comprising:
- applying a printing composition including an aqueous medium,
- a hydroquinonesulfonic acid salt in said aqueous medium, and
- a humectant in said aqueous medium, wherein said printing composition is adapted to print a latent image that reacts with a water soluble salt to produce a reaction product having a color visible in ambient light, to a substrate to encode said information on said substrate;
- and reacting said printing composition on said substrate with said water soluble salt to decode said information.
1 more element
Dependencies are inferred from the claim text.