| 摘要 |
The present invention provides jet ink compositions suitable for producing security markings on documents and other articles for subsequent identification. The jet ink composition comprises a fluorescent colorant, an ink carrier, and optionally one or more binder resins. The markings are invisible to the unaided eye and are visible only when excited by ultraviolet light. The colorant comprises a rare earth metal and a chelating ligand, is excitable by ultraviolet light having a wavelength of from about 275 nm to about 400 nm, and fluoresces at a wavelength of from about 550 nm to about 700 nm, with the proviso that when the rare earth metal is europium, dysprosium, or terbium, the chelating ligand is not dibenzoylmethane. The present invention further provides a method of identifying objects comprising providing a security marking as described above, exciting the marking and reading the fluorescent emission. The present invention also provides a system for identification of objects bearing the security markings.
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