PROTECTIVE PRINTING LIQUID AND A METHOD OF PRINTING WITH NANOPARTICLES Russian patent published in 2007 - IPC C09K11/08 C09D11/00 B41J2/00 B41M3/14 

FIELD: printing engineering.

SUBSTANCE: invention, in particular, relates to a method of printing allowing protection of printing materials against counterfeit reprints, for instance in fabrication of banknotes, shares, checks, and other valuable paper documents. Invention provides printing liquid for printing through narrow nozzles onto objects, in particular when fabricating banknotes, shares, and checks, which liquid comprises carrying medium and nanoparticles of metal salts in the form of crystalline solid particles having average diameter less than 300 nm, which fluorescent and phosphorescent when excited by UV emission of the A, B, or C band, or visual light, while emitted fluorescent and phosphorescent waves do not lie in the visual light frequency region and excitation frequency region and emission frequency region are shifted in frequency scale. Nanoparticles contain enhancing additives of at least one type having excitation and emission frequency ranges corresponding to fluorescence and phosphorescence. Provided is also printing method including injecting of above-described liquid(s) through one or several narrow nozzles, which are regulated individually or by groups in relation to availability or lack of printing liquid and in relation to duration or intensity of flowing of printing liquid. Printing method is either piezoelectric method or jet printing one. Employment of proposed liquid for ink-pots and object marking, in particular when fabricating banknotes, shares, and checks involving printing equipment provided with one or several narrow nozzles is also described.

EFFECT: increased reliability of protection.

15 cl, 2 dwg