Infrared and visible dual dye jet printer ink

Claim 2

AN OPTICAL CHARACTER READER READABLE AND VISUALLY READABLE INK JET INK FORMULATION COMPRISINGAN INFRARED ABSORBING DYE WHICH EXHIBITS HIGH ABSORPTIVITY FOR RADIATION WITH A WAVELENGTH OF ABOUT 9000A, PRESENT IN THE INK FORMULATION IN ABOUT 1 TO 5 PERCENT; A DYE WHICH HIGHLY ABSORBS IN THE VISIBLE SPECTRUM AND WHICH PERMENANETLY DYES THE FIBERS OF A CELLULOSIC SUBSTRATE PRESENT IN ABOUT 2 TO 5 PERCENT CONCENTRATION AND WHERE SAID DYE IS SELECTED FROM GROUP CONSISTING OF DYES HAVING COLOR INDEX NUMBERS OF 30235; A POLYETHYLENE GLYCOL OF AN AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 500 TO 600, PRESENT IN THE INK IN ABOUT 1 TO 3.5 PERCENT: A DYE SOLVENT FOR AT LEAST ONE OF SAID DYES, PRESENT IN THE INK IN THE AMOUNT OF ABOUT 2.0 TI 4.5 PERCENT WHEREIN SAID SOLVENT IS SELECTED FROM THE GROUP CONSISTING OF N-METJYL2-PYRROLIDONE AND DIETHYLENE GLYCOL MONOETHYL ETHER; DIETHYLENE GLYCOL MONOBUTYL ETHER PRESENT IN THE INK IN THE AMOUNT OF ABOUT 0.25 TO 0.75 PERCENT; AND THE BALANCE WATER, ALL PERCENTAGES BEING PERCENTAGES BY WEIGHT WITH RESPECT TO THE WEIGHT OF THE ENTIRE INK FORMULATION.

Claim 3

An optical character reader readable and visually readable ink jet ink formulation comprising: an infrared absorbing dye which exhibits high absorptivity for radiation with a wavelength of about 9000 A, present in the ink formulation in about 1 to 5 percent; a dye which highly absorbs in the visible spectrum and which permanently dyes the fibers of a cellulosic substrate present in about 2 to 5 percent concentration and where said dye is selected from group consisting of dyes having color index numbers of 30235 and 30245; a polyethylene glycol of an average molecular weight of from about 500 to 600, present in the ink in about 1 to 3.5 percent: a dye solvent for at least one of said dyes, present in the ink in the amount of about 2.0 to 4.5 percent wherein said solvent is selected from the group consisting of N-methyl-2-pyrrolidone and diethylene glycol monoethyl ether; diethylene glycol monobutyl ether present in the ink in the amount of about 0.25 to 0.75 percent; and the balance water, all percentages being percentages by weight with respect to the weiGht of the entire ink formulation.

Claim 4

An optical character reader readable and visually readable ink jet ink formulation comprising: an infrared absorbing dye which exhibits high absorptivity for radiation with a wavelength of about 9000 A, present in the ink formulation in about 1 to 5 percent; a dye which highly absorbs in the visible spectrum and which permanently dyes the fibers of a cellulosic substrate present in about 2 to 5 percent concentration and where said dye is selected from group consisting of dyes having color index numbers of 30235 and 30245; a polyethylene glycol of an average molecular weight of from about 500 to 600, present in the ink in about 1 to 3.5 percent: a dye solvent for at least one of said dyes, present in the ink in the amount of about 2.0 to 4.5 percent wherein said solvent is selected from the group consisting of N-methyl-2-pyrrolidone and diethylene glycol monoethyl ether; diethylene glycol monobutyl ether present in the ink in the amount of about 0.25 to 0.75 percent; and the balance water, all percentages being percentages by weight with respect to the weiGht of the entire ink formulation.

Claim 5

claim 1 wherein said infrared absorbing dyes is water soluble Nigrosine.

Claim 6

claim 2 wherein said water contains an effective concentration of an anti-microbial agent selected from the group consisting of sodium-2-pyridinethiol-1-oxide and sodium propionate.