US 11,884,831 B2
Photochromic inkjet inks and methods of making photochromic inkjet inks for security printing applications
Xiaorong Cai, Mount Pleasant, SC (US); and Michael R. Riley, Steubenville, OH (US)
Assigned to TROY GROUP, INC., Costa Mesa, CA (US)
Filed by TROY GROUP, INC., Costa Mesa, CA (US)
Filed on Nov. 26, 2019, as Appl. No. 16/695,757.
Claims priority of provisional application 62/772,495, filed on Nov. 28, 2018.
Prior Publication US 2020/0165478 A1, May 28, 2020
Int. Cl. C09D 11/50 (2014.01); C09D 11/328 (2014.01); C09D 11/102 (2014.01); C09D 11/38 (2014.01); C09D 11/106 (2014.01); C09D 11/36 (2014.01)
CPC C09D 11/50 (2013.01) [C09D 11/102 (2013.01); C09D 11/106 (2013.01); C09D 11/328 (2013.01); C09D 11/36 (2013.01); C09D 11/38 (2013.01)] 29 Claims
OG exemplary drawing
 
1. A method of making a photochromic inkjet ink for printing invisible marks on a porous substrate with an inkjet printer, the printed marks changing to a visible color upon exposure to sunlight or UV light, the method comprising:
dissolving a photochromic dye, from 0.1% to 10% by weight of the ink composition, in a non-volatile organic solvent;
mixing a polymer resin, from 1% to 10% by weight of the ink composition, into the non-volatile organic solvent containing the photochromic dye; and
mixing surface modifying agents and additives into the non-volatile organic solvent containing the photochromic dye and polymer resin, and
wherein the photochromic inkjet ink is configured to be printed by the inkjet printer and includes the mixture of the surface modifying agents and additives with the non-volatile organic solvent containing the photochromic dye and polymer resin.