The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 08, 2011
Filed:
Jan. 10, 2008
Terry W. Stovold, Raleigh, NC (US);
Joann Domanski, Kennett Square, PA (US);
Terry W. Stovold, Raleigh, NC (US);
JoAnn Domanski, Kennett Square, PA (US);
Nocopi Technologies, Inc., W. Conshohocken, PA (US);
Abstract
An invisible ink, a method for preparing an invisible ink, and an invisible ink product are disclosed herein. An invisible ink comprising a first ink combined with a second ink is applied to a print medium. The first ink comprises a color developer activator without a color former leuco dye and the second ink comprises a color former leuco dye without a color developer activator. The first ink is prepared with a polyvinyl alcohol binder, dispersant/surfactant, and a wetting agent. The second ink is prepared with a polyvinyl alcohol binder, grind aid, dispersant/surfactant and defoamer. Heat generated by rubbing and/or scratching the invisible ink on the print medium activates the color former leuco dye and activator to change the color on the printing medium.