Ink jet printing of concealed images on carbonless paper

Claim 2

A process which comprises the steps of: (1) incorporating into a printing apparatus for generating ink jet images a carbonless paper set comprising a first sheet having two major surfaces, a second sheet having two major surfaces, and optional intermediate sheets having two major surfaces situated between the first sheet and second sheet, wherein the first sheet comprises paper coated on one surface with a color former and the second sheet comprises paper coated on one surface with a color developer, and wherein, when the carbonless paper set is assembled, the surface of the first sheet coated with the color former is in contact with the surface of a sheet coated with the color developer and the surface of the second sheet coated with the color developer is in contact with the surface of a sheet coated with the color former; (2) incorporating into the printing apparatus an ink jet ink comprising (a) water; (b) a member selected from the group consisting of glycols, sulfolane, and mixtures thereof; (c) optionally, an alcohol component selected from the group consisting of ethanol, isopropanol, n-butanol, benzyl alcohol, hexanetriol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, 1,3-butanediol, and mixtures thereof; (d) diethylene glycol monobutyl ether; (e) optionally, dipropylene glycol monomethyl ether acetate; and (f) a marking material which is substantially colorless and detectable when exposed to radiation outside of a visible wavelength range; and (3) causing droplets of the ink to be ejected in an imagewise pattern onto at least one surface of at least one of the sheets of the carbonless paper set.

Claim 3

A process according to claim 1 wherein the ink jet ink comprises water, ethylene glycol, isopropanol, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether acetate, and the marking material.

Claim 4

A process according to claim 1 wherein the ink jet ink contains the marking material in an amount of from about 0.1 to about 6 percent by weight, the glycol or sulfolane component in an amount of from about 5 to about 30 percent by weight, the alcohol component in an amount of from 0 to about 5 percent by weight, diethylene glycol monobutyl ether in an amount of from about 6 to about 20 percent by weight, dipropylene glycol monomethyl ether acetate in an amount of from 0 to about 10 percent by weight, and water in an amount of from about 24 to about 88.9 percent by weight.

Claim 5

A process according to claim 1 wherein the ink jet ink has a surface tension of from about 25 to about 45 dynes per square centimeter.

Claim 6

A process according to claim 1 wherein the marking material is a dye selected from the group consisting of 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetrachloride salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetrabromide salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetraacetate salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetra-perchlorate salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetrafluoroborate salt; 5,10,15,20-tetrakis-( 1 -methyl-4-pyridyl)-21H,23H-porphine tetra-perchlorate salt; 5,10,15,20-tetrakis-(1-methyl-4-pyridyl)-21H,23H-porphine tetra-triflate salt; 5,10,15,20-tetrakis-(1-hydroxymethyl-4-pyridyl)-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[1-(2-hydroxyethyl)-4-pyridyl]-21 H,23H-porphine tetrachloride salt; 5,10,15,20-tetrakis-[1-(3-hydroxypropyl)-4-pyridyl]-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[1-(2-hydroxypropyl)-4-pyridyl]-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[1-(2-hydroxyethoxyethyl)-4-pyridyl]-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[1-(2-hydroxyethoxypropyl)-4pyridyl]-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetra-p-tosylate salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetrachloride salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetrabromide salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetra-acetate salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetraperchlorate salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetrafluoroborate salt; 5,10,15,20-tetrakis-[4-(trimethylammonio)phenyl]-21H,23H-porphine tetra-triflate salt; meso-(N-methyl-X-pyridinium) n -(phenyl)-4-n-21H,23H-porphine tetra-p-tosylate salt, where n is an integer of value 0, 1, 2, or 3, and where X=4-(para), 3-(meta), or 2-(ortho) and refers to the position of the nitrogen in the pyridinium substituent; meso-tetrakis-[o-(N-methylnicotinamido)phenyl]-21H,23H-porphine tetra-methyl sulfonate salt; 5,10,15,20-tetrakis-(2-sulfonatoethyl-4-pyridyl)-21H,23H-porphine chloride salt; 5,10,15,20-tetrakis-(carboxymethyl-4-pyridyl)-21H,23H-porphine chloride salt; 5,10,15,20-tetrakis-(carboxyethyl-4-pyridyl)-21H,23H-porphine chloride salt; 5,10,15,20-tetrakis-(carboxyethyl-4-pyridyl)-21H,23H-porphine bromide salt; 5, 10, 15,20-tetrakis-(carboxylate-4-pyridyl)-21H,23H-porphine bromide salt; 2,3,7,8,12,13,17,18-octa-(2-hydroxyethyl)-21H-23H-porphine; 2,3,7,8, 12,13, 17,18-octa-(2-hydroxyethoxyethyl)-21H-23H-porphine; 2,3,7,8,12,13,17,18-octa-(2-aminoethyl)-2 1H-23H-porphine; 2,3,7,8,12,13,17,18-octa-(2-hydroxyethoxypropyl)-21H-23H-porphine; and mixtures thereof.

Claim 7

A process according to claim 1 wherein the marking material is a dye selected from the group consisting of dansyl-L-alanine; Dansyl-L-α-amino-n-butyric acid; α-dansyl-L-arginine; dansyl-L-asparagine; dansyl-L-aspartic acid; dansyl-L-cysteic acid; N,N'-di-dansyl-L-cystine; dansyl-L-glutamic acid; dansyl-L-glutamine; N-dansyl-trans-4-hydroxy-L-proline; dansyl-L-isoleucine; dansyl-L-leucine; di-dansyl-L-lysine; N-ε-dansyl-L-lysine; dansyl-L-methionine; dansyl-L-norvaline; dansyl-L-phenylalanine; dansyl-L-proline; N-dansyl-L-serine; N-dansyl-L-threonine; Nα-dansyl-L-tryptophan ; N,O-di-dansyl-L-tyrosine monocyclohexylammonium salt; dansyl-L-valine; dansyl-γ-amino-n-butyric acid; dansyl-DL-α-amino-n-butyric acid; dansyl-DL-aspartic acid; dansyl-DL-glutamic acid; dansylglycine; dansyl-DL-leucine; dansyl-DL-methionine; dansyl-DL-norleucine; dansyl-DL-norvaline; dansyl-DL-phenylalanine; dansylsarcosine; N-dansyl-DL-serine ; N-dansyl-DL-threonine ; Nα-dansyl-DL-tryptophan; dansyl-DL-valine; dansyl-DL-α-aminocaprylic acid cyclohexylamine salt; (dansylaminoethyl)-trimethylammonium perchlorate; didansylcadaverine; monodansylcadaverine; dansylputrescine; dansylspermidine; didansyl-1,4-diamino-butane; didansyl-1,3-diamino-propane; didansylhistamine; and mixtures thereof.

Claim 8

A process according to claim 1 wherein the marking material is a pigment.

Claim 9

A process according to claim 1 wherein the ink jet ink has a viscosity of no more than about 8 centipoise.

Claim 10

A process according to claim I wherein the printing apparatus employs a thermal ink jet printing process wherein the ink is contained in nozzles which are selectively heated in an imagewise pattern, thereby causing droplets of the ink to be ejected in imagewise pattern.

Claim 11

A printing process which comprises steps of (1) incorporating into an imaging apparatus capable of generating both electrostatic images and ink jet images a carbonless paper set comprising a first sheet having two major surfaces, a second sheet having two major surfaces, and optional intermediate sheets having two major surfaces situated between the first sheet and second sheet, wherein the first sheet comprises paper coated on one surface with a color former and the second sheet comprises paper coated on one surface with a color developer, and wherein, when the carbonless paper set is assembled, the surface of the first sheet coated with the color former is in contact with the surface of a sheet coated with the color developer and the surface of the second sheet coated with the color developer is in contact with the surface of a sheet coated with the color former; (2) generating an electrostatic latent image on an imaging member in the imaging apparatus, developing the latent image with a toner, and contacting the developed image on the imaging member with the first sheet of the carbonless paper set, thereby transferring the developed image to the first sheet; (3) generating an electrostatic latent image on the imaging member in the imaging apparatus, developing the latent image with a toner, and contacting the developed image on the imaging member with the second sheet of the carbonless paper set, thereby transferring the developed image to the second sheet; (4) optionally permanently affixing to the first and second sheets the developed images transferred thereto in steps (2) and (3); (5) incorporating into the imaging apparatus an ink jet ink comprising (a) water; (b) a member selected from the group consisting of glycols, sulfolane, and mixtures thereof; (c) optionally, a member selected from the group consisting of ethanol, isopropanol, n-butanol, benzyl alcohol, hexanetriol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, 1,3-butanediol, and mixtures thereof; (d) diethylene glycol monobutyl ether; (e) optionally, dipropylene glycol monomethyl ether acetate; and (f) a marking material which is substantially colorless and detectable when exposed to radiation outside of a visible wavelength range; and (6) causing droplets of the ink to be ejected in an imagewise pattern onto at least one surface of at least one of the sheets of the carbonless paper set.

Claim 12

A printing process which comprises steps of (1) incorporating into an imaging apparatus capable of generating both electrostatic images and ink jet images a carbonless paper set comprising a first sheet having two major surfaces, a second sheet having two major surfaces, and optional intermediate sheets having two major surfaces situated between the first sheet and second sheet, wherein the first sheet comprises paper coated on one surface with a color former and the second sheet comprises paper coated on one surface with a color developer, and wherein, when the carbonless paper set is assembled, the surface of the first sheet coated with the color former is in contact with the surface of a sheet coated with the color developer and the surface of the second sheet coated with the color developer is in contact with the surface of a sheet coated with the color former; (2) generating an electrostatic latent image on an imaging member in the imaging apparatus, developing the latent image with a toner, and contacting the developed image on the imaging member with the first sheet of the carbonless paper set, thereby transferring the developed image to the first sheet; (3) generating an electrostatic latent image on the imaging member in the imaging apparatus, developing the latent image with a toner, and contacting the developed image on the imaging member with the second sheet of the carbonless paper set, thereby transferring the developed image to the second sheet; (4) optionally permanently affixing to the first and second sheets the developed images transferred thereto in steps (2) and (3); (5) incorporating into the imaging apparatus an ink jet ink comprising (a) water; (b) a member selected from the group consisting of glycols, sulfolane, and mixtures thereof; (c) optionally, a member selected from the group consisting of ethanol, isopropanol, n-butanol, benzyl alcohol, hexanetriol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, 1,3-butanediol, and mixtures thereof; (d) diethylene glycol monobutyl ether; (e) optionally, dipropylene glycol monomethyl ether acetate; and (f) a marking material which is substantially colorless and detectable when exposed to radiation outside of a visible wavelength range; and (6) causing droplets of the ink to be ejected in an imagewise pattern onto at least one surface of at least one of the sheets of the carbonless paper set.

Claim 13

A process according to claim 10 wherein the imaging apparatus employs a thermal ink jet printing process, wherein the ink is contained in nozzles which are selectively heated in an imagewise pattern, thereby causing droplets of the ink to be ejected in imagewise pattern.

Claim 14

A printing process which comprises steps of (1) incorporating into an ink jet imaging apparatus a carbonless paper set comprising a first sheet having two major surfaces, a second sheet having two major surfaces, and optional intermediate sheets having two major surfaces situated between the first sheet and second sheet, wherein the first sheet comprises paper coated on one surface with a color former and the second sheet comprises paper coated on one surface with a color developer, and wherein, when the carbonless paper set is assembled, the surface of the first sheet coated with the color former is in contact with the surface of a sheet coated with the color developer and the surface of the second sheet coated with the color developer is in contact with the surface of a sheet coated with the color former; (2) incorporating into the printing apparatus an ink jet ink comprising water and a colorant; (3) causing droplets of the ink containing the colorant to be ejected in an imagewise pattern onto at least one surface of the first sheet; (4) causing droplets of the ink containing the colorant to be ejected in an imagewise pattern onto at least one surface of the second sheet; (5) incorporating into the printing apparatus an ink jet ink comprising (a) water; (b) a member selected from the group consisting of glycols, sulfolane, and mixtures thereof; (c) optionally, a member selected from the group consisting of ethanol, isopropanol, n-butanol, benzyl alcohol, hexanetriol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, 1,3-butanediol, and mixtures thereof; (d) diethylene glycol monobutyl ether; (e) dipropylene glycol monomethyl ether acetate; and (f) a marking material which is substantially colorless and detectable when exposed to radiation outside of a visible wavelength range; and (6) causing droplets of the ink to be ejected in an imagewise pattern onto at least one surface of at least one of the sheets of the carbonless paper set.

Claim 15

A printing process which comprises steps of (1) incorporating into an ink jet imaging apparatus a carbonless paper set comprising a first sheet having two major surfaces, a second sheet having two major surfaces, and optional intermediate sheets having two major surfaces situated between the first sheet and second sheet, wherein the first sheet comprises paper coated on one surface with a color former and the second sheet comprises paper coated on one surface with a color developer, and wherein, when the carbonless paper set is assembled, the surface of the first sheet coated with the color former is in contact with the surface of a sheet coated with the color developer and the surface of the second sheet coated with the color developer is in contact with the surface of a sheet coated with the color former; (2) incorporating into the printing apparatus an ink jet ink comprising water and a colorant; (3) causing droplets of the ink containing the colorant to be ejected in an imagewise pattern onto at least one surface of the first sheet; (4) causing droplets of the ink containing the colorant to be ejected in an imagewise pattern onto at least one surface of the second sheet; (5) incorporating into the printing apparatus an ink jet ink comprising (a) water; (b) a member selected from the group consisting of glycols, sulfolane, and mixtures thereof; (c) optionally, a member selected from the group consisting of ethanol, isopropanol, n-butanol, benzyl alcohol, hexanetriol, 1,6-hexanediol, 1,5-pentanediol, 1,4-butanediol, 1,3-butanediol, and mixtures thereof; (d) diethylene glycol monobutyl ether; (e) dipropylene glycol monomethyl ether acetate; and (f) a marking material which is substantially colorless and detectable when exposed to radiation outside of a visible wavelength range; and (6) causing droplets of the ink to be ejected in an imagewise pattern onto at least one surface of at least one of the sheets of the carbonless paper set.

Claim 16

A process according to claim 10 wherein the inkjet printing process is a thermal ink jet printing process, wherein the ink is contained in nozzles which are selectively heated in an imagewise pattern, thereby causing droplets of the ink to be ejected in imagewise pattern.