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

Claim 27:
28. A photochromic inkjet ink formulation that prints an invisible mark on a substrate and changes to a visible mark upon exposure to sunlight or UV light, the formulation comprising:
a photochromic dye at about 3% by weight of the ink formulation;
alcohol at about 20% by weight of the ink formulation;
vinyl chloride or vinyl acetate resin at about 10% by weight of the ink formulation;
acetate at about 2% by weight of the ink formulation;
glycol ether at about 0.5% of the ink formulation;
surfactant at about 0.3% of the ink formulation; and
an ester at about 64% of the ink formulation, and
wherein the ink formulation is for printing by an inkjet printer.