Patent ID: 11884831
Assignee: TROY GROUP, INC.
Field: Basic materials chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 0:
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.