Patent ZA-200502404-B (ZA)
Title: Method and ink sets marking and authenticating articles
Inventor: DEGOTT PIERRE
IPC: G07D/
Filed: 2005-03-23
Abstract: Printing ink comprises at least one dye or pigment with at least one absorption maximum in visible range of electromagnetic spectrum different from absorption maxima of base colors of Commission Internale d'Eclairge with visible color coordinates of red, green and blue system and/or having absorption band in visible range whose band width at half intensity is narrower than 2400, preferably narrower than 1500 cm ->1. Printing ink, comprises at least one dye or pigment having at least one absorption maximum in the visible range of the electromagnetic spectrum that is substantially different from the absorption maxima of the base colors of the Commission Internale d'Eclairge with three basic visible color coordinates of red, green and blue (CIEXYZ) system and/or having an absorption band in the visible range of the electromagnetic spectrum whose band width at half intensity is narrower than 2400 cm ->1, preferably narrower than 1500 cm ->1. Independent claims are also included for: (a) a set of printing inks, comprising >=2 printing inks as above; (b) a method for marking an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good, comprising providing on the article a marking that is applied using printing ink(s) above or a set of printing inks above using coating composition(s) comprising printing ink(s) above or a set of printing inks above; (c) a method of authenticating an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good, comprising measuring an absorbance, reflectance or transmittance spectrum of an article marked using the method above, in the ultraviolet, visible and/or infrared wavelength domain of the electromagnetic spectrum; and comparing the spectrum measured and/or information derived from it with a corresponding spectrum of an authentic item and/or information derived from it; (d) a marking, comprising printing ink(s) above and/or set(s) of printing inks above; (e) an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good, comprising marking above; (f) use of a dye or pigment having at least one absorption maximum in the visible range of the electromagnetic spectrum that is substantially different from the absorption maxima of the base colors of the CIEXYZ system and/or having an absorption band in the visible range of the electromagnetic spectrum whose band width at half intensity is narrower than 2400 cm ->1, preferably narrower than 1500 cm ->1, for marking and/or authenticating an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good; (g) use of a printing ink or a set of printing inks above for marking and/or authenticating an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good; and (h) use of a marking as above for authenticating an article, such as a banknote, a document, a ticket, a foil, a thread, a label, a card, or a commercial good.