Homogeneous photosensitive optically variable ink compositions for ink jet printing
US6793723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2002 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | May 9, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2211/1018
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Ink compositions described are suitable for ink jet printing (ink jet inks) and are highly effective for simultaneously imparting visible and fluorescent images. In the preferred forms, both a dark, visible image and a complementary fluorescent image will be visually discernable as well as machine readable to enable efficient hand and automated processing or handling of the objects printed. These results are achieved by ink formulations that moderate the typically occurring phenomenon of quenching while possessing the physical properties necessary for an ink jet ink. In one form, the inks comprise a first colorant comprising at least one fluorescent dye, the fluorescent dye emitting light within a characteristic emission band when excited by fluorescent-exciting radiation; a second colorant having a light absorption band at longer wavelengths than the characteristic emission band of the first colorant, the second colorant comprising a water-soluble polymeric dye of effective molecular configuration to inhibit quenching of fluorescence of said first colorant due to collisional and resonance energy transfer with said second colorant; and an aqueous liquid vehicle comprising water and…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.