WO2018199968A1

WO2018199968A1 - Inks inlcuding a near infrared absorbing dye

Info

Publication number: WO2018199968A1
Application number: PCT/US2017/029964
Authority: WO
Inventors: Fred Charles Thomas, Iii; Paul Howard Mazurkiewicz; Bruce E. Blaho; Scott Rawlings
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2017-04-27
Filing date: 2017-04-27
Publication date: 2018-11-01

Abstract

According to an example, an ink may include a white-colored inorganic pigment; a near infrared absorbing dye; and a carrier.

Description

INKS INLCUDING A NEAR INFRARED ABSORBING DYE

BACKGROUND

[0001] Users are increasingly demanding functionalities beyond merely recognizing a touch to the surface of a touch-sensitive device. Such other functionalities include handwriting recognition and direct note taking (using, for example, a stylus). Such functionalities are generally provided in so-called digitizing systems. Digitizing systems may have position-dependent indicia defected by an image sensor in a stylus, such as an electro-optical pen or other image reader, where the position-dependent indicia include an ink.

BRIEF DESCRIPTION OF THE DRAWING

[0002] Features of the present disclosure are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which:

[0003] FIG. 1 is a simplified diagram of an example ink;

[0004] FIG. 2 is a simplified diagram of an example printed medium; and

[0005] FIG. 3 is a flow chart of an example of a method of making an example ink.

DETAILED DESCRIPTION

[0006] For simplicity and illustrative purposes, the present disclosure is described by referring mainly to an example thereof. In the following description, numerous specific details are set forth in order to provide a thorough

understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these specific details. In other instances, some methods and structures have not been described in detail so as not to unnecessarily obscure the present disclosure. As used herein, the terms "a" and "an" are intended to denote at least one of a particular element, the term "includes" means includes but not limited to, the term "including" means including but not limited to, and the term "based on" means based at least in part on.

[0007] With reference to FIG. 1 , there is shown a simplified diagram of an example ink 100. The ink 100 may include a white-colored inorganic pigment 120; a near infrared absorbing dye 130; and a carrier 1 10. The ink 100 may be visibly white-colored and may absorb, or may not reflect, light in the near infrared wavelength (about 700 nm to about 1000 nm, for example about 850 nm). In another aspect, the ink 100 may include a white-colored ink (not shown) and a near infrared absorbing dye 130. As shown in FIG. 2, the ink 100 may be applied to a white-colored surface 210, such as white paper or a whiteboard, in a pattern of indicia 220 so that the pattern may be invisible to the human eye to create a printed medium 200. The near infrared absorbing dye 130 present in the ink 100 may make the visibly white-colored ink appear black in color to an electro-optical (E/O) pen or other electronic reader. However, because the ink 100 is white-colored, the ink 100 may blend into a white-colored surface 210 providing an aesthetically appealing coloration.

[0008] The white-colored inorganic pigment 120 may be present in the ink 100 in an amount ranging from about 15 wt.% to about 65 wt.% relative to the total weight of the ink 100. In an aspect, the white-colored inorganic pigment 120 may be present in the ink 100 in an amount ranging from about 20 wt. % to about 40 wt. %, for example, from about 25 wt. % to about 35 wt. %, relative to the total weight of the ink 100.

[0009] The white-colored inorganic pigment 120 may be any pigment that is visibly white-colored. Non-limiting examples of a white-colored inorganic pigment 120 for use in the ink 100 include titanium oxides, zinc oxide, zinc sulphides, zirconium oxide, silicon dioxide, aluminum oxides, white lead, basic lead sulfate, barium sulfate, calcium carbonate (precipitated, ground, and treated), calcium silicate, kaolin clay, talc, silica, and combinations thereof. In an aspect, the white-colored inorganic pigment 120 may include sodium aluminosilicate particles, aluminum-doped zinc oxide, zinc dioxide, titanium dioxide, polytetrafluoroethylene, and combinations thereof.

[0010] The ink 100 may also include a near infrared absorbing dye 130. The near infrared absorbing dye 130 may be any organic dye that absorbs, or does not reflect, light in the near infrared wavelength (about 700 nm to about 1000 nm) and transmits light in the visible wavelength (about 400 nm to about 699 nm). The near infrared absorbing dye 130 may be visibly transparent and infrared opaque to reduce the reflection in the near infrared wavelength relative to the visible wavelengths. The near infrared absorbing dye 130 may be color neutral. In an aspect, the near infrared absorbing dye 130 and the white-colored inorganic pigment 120 may be the same compound. Suitable near infrared absorbing dyes 130 may be available, for example, from HW Sands, Epolin, and QRC Solutions.

[0011] Non-limiting examples of near infrared absorbing dyes 130 include

mixtures thereof. In the above formulations, M may be a divalent metal atom (e.g., copper) or may have OSOaNa axial groups filling any unfilled valencies if the metal is more than divalent (e.g., indium), R may be any C₁-C₈ alkyl group (including substituted alkyl and unsubstituted alkyl), and Z may be a counterion such that the overall charge of the near-infrared absorbing dye 130 is neutral. For example, the counterion may be sodium, lithium, potassium, NHj⁺, etc.

[0012] In one aspect, the near infrared absorbing dye 130 may include:

mixtures thereof. In the above formulations, R may be any C₁-C₈ alkyl group (including substituted alkyl and unsubstituted alkyl). In another aspect, the near infrared absorbing dye 130 may be a hydrophobic near infrared absorbing dye. The hydrophobic near infrared absorbing dye 130 may include:

and mixtures thereof. For hydrophobic near infrared absorbing dyes, M may be a divalent metai atom (e.g., copper) or may include a metal that has CI, Br, OR' (R' = H, CH₃, COCH3, COCH₂COOCH3, COCH₂COCH3) axial groups filling any unfilled valencies if the metal is more than divalent, and R may be any C₁-C₈ alkyl group (including substituted alkyl and unsubstituted alkyl). In one aspect, the hydrophobic near infrared absorbing dye may include:

mixtures thereof. For hydrophobic near infrared absorbing dye, may be a divalent metal atom (e.g., copper) or may include a metal that has CI, Br, OR' (R' = H, CH₃, COCH₃, COCH₂COOCH₃, COCH₂COCH₃) axial groups filling any unfilled valencies if the metal is more than divalent, and R may be any C₁-C₈ alkyl group (including substituted alkyl and unsubstituted alkyl).

[0013] While M in the above formulations may be any metal, in an aspect, the metal may include indium, gallium, thallium, germanium, tin (II and IV), antimony, bismuth, zinc, cobalt, copper, nickel, silicon, titanium, vanadium, chromium, manganese, yttrium, scandium, zirconium, niobium, molybdenum, ruthenium, rhodium, hafnium, tantalum, bismuth, and mixtures thereof.

[0014] In an aspect, the near infrared absorbing dye 130 may be solvent soluble. Non-limiting examples of solvent soluble near infrared absorbing dyes 130 include:

2-[2-[2-Chloro-3-[(1 ,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene]-1-cy cloxen-1-yl]-ethenyl]-1,3,3-trimethyl-1 H indolium iodide; 2-[2-[2-Chloro-3-[(1 ,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene]-1-cy cloxen-1-yl]-ethenyl]-1,3,3-trimethyl-1 H indolium perchlorate;

2-[2-[2-Chloro-3-[(1 ,3-dihydro-3,3-dimethyl-1-propyl-2H-indol-2-ylidene)ethyliden e]-1 -cycloxen-1 -yl]-ethenyl]-3,3-dimethy-1 -propyl-1 H-indolium iodide;

2-[2-[2-Chloro-3-[(1 ,3-dihydro-3,3-dimethyl-1-propyl-2H-indol-2-ylidene)ethyliden e]-1 -cycloxen-1 -yl]-ethenyl]-3,3-dimethy-1 -propyl-1 H-indolium perchlorate;

2-[2-[2-Chloro-3-[(1 ,3-dihydro-3,3-dimethyl-1-(2-hydroxyethyl)-2H-indol-2-yliden e)ethylidene]-1 -cycloxen-1 -yl]-ethenyl]-3,3-dimethy-1-(2-hydroxyethyl)-1 H-indoli um perchlorate;

2-[2-[3-[2-(1 ,3-Dihydro-1,3,3-trimethyl-2H-indol-2-ylideneJ-ethylidenel-2-(1-phen yl-1 H-tetrazol-5-ylsulfanyl)-1 -cyclohexen-1 -yl]-ethenyl]-1,3,3-trimethyl-3H-indoliu m chloride;

2-[2-[2-(4-Methylbenzeneoxy)-3-[2-(1 ,3-dihydro-1 ,1 ,3-trimethyl-2H-benz[e]indol- 2-yilidene)ethylidene]-1-cylohexen-1-yl]-ethenyl]-1 ,1 ,3-trimethyl-1 H-benz[e]indoli um 4-methylbenzenesulfonate;

2-[2-[2-chloro-3-[2-(1 ,3-dihydro-3,3-dimethyl-1-ethyl-2H-benz[e]indol-2-ylidene)e thylidene]-1 -cylohexen-1 -yl]-ethenyl]-3,3-dimethyl-1 -ethyl- 1 H-benz[e]indolium iodide;

2-[2-[2-chloro-3-[2-(1 ,3-dihydro-1 , 1 ,3-trimethyl-2H-benz[e]indol-2-ylidene)ethylid ene]-1 -cylohexen-1 -yl]-ethenyl]-1 ,1 ,3-trimethyl-l H-benz[e]indolium

4-methylbenzenesulfonate;

1 ,4-Benzenediamine,N,N-bis[4-(dibutylamino)phenyl]-N',N^,-diethyl-,radical ion (2+), bis [hexafluoroantimonate (1-)];

4,4',4"-tris(N,N-phenyl-3-methylphenylamino)triphenylammonium

hexafluoroantimonate; and combinations thereof.

[0015] In an aspect, the near infrared absorbing dye 130 may be water soluble. Non-limiting examples of water soluble near infrared absorbing dyes include: 2-[2-[2-Chloro-3-[2-(1 ,3-dihydro-3,3-dimethyl-1 -(4-sulfobutyl)-2H-indol-2-yli -ethylidene]-1 -cyclohexen-1 -yl]-ethenyl]-3,3-dimethyl-1 -(4-sulfobutyl)-1 H-indoliu m, inner salt, monosodium;

2-[7-(1 ,3-Dihydro-3,3-dimethy-1 -(4-sulfobutyl)l-2H-benz[e]indol-2-ylidene)-1 ,3,5- heptatrienyl]-3,3-dimethyl-1 -(4-sulfobutyl)-1 H-benz[e]indolium innersalt, monosodium;

2-[2-[2-(4-aminobenzenethio)-3-[(1 ,3-dihydro-3,3-dimethyl-1 -(4-sulfobutyl)-2H-in dol-2-ylidene)-ethylidene]-1 -cycloxen-1 -yl]-ethynyl]-3,3-dimethyl-1 -(4-sulfobutyl)- 3H-indolium, innersalt, monosodium;

2-[2-[2-Chloro-3-[2-(3-(4-sulfobutyl)-3H-benzothiazol-2-ylidene)-ethylidene]-1 -cy clohexen-1 -yl]-ethenyl]3-(4-sulfobutyl)benzothiazolium, inner salt,

triethylammonium salt;

2-[2-[2-Chloro-3-[2-(1 ,3-dihydro-3,3-dimethyl-1 -(4-sulfobutyl)-2H-benz[e]-indol-2 -ylidene)-ethylidene]-1 -cyclohexen-1 -yl]-ethenyl]-3,3-dimethyl-1 -(4-sulfobutyl)-1 H-benz[e]indolium, inner salt, free acid;

2-2-[2-[2-(4-aminothiophenyl)-3-[[1 ,3-dihydro-1 , 1 -dimethyl-3-(4-sulfobutyl)-2H-b enz[e]-indol-2-ylidene]ethylidene]-1 -cyclohexen-1 -yl]ethenyl]-1 , 1 -dimethyl-3-(4-s ulfonyl)-, inner salt, sodium salt; and combinations thereof.

[0016] In an aspect, the near infrared absorbing dye 130 may be a metal-complex. Non-limiting examples of metal-complex near infrared absorbing dyes include:

Tetrabutylammonium bis(3,6-dichloro-1 ,2-benzene-dithiolato)nickelate;

Tetrabutylammonium bis(3,4,6-trichloro-1 ,2-benzene-dithiolato)nickelate;

Tetrabutylammonium bis(4-methyl-1 ,2-benzenedithiolato) nickelate;

Bis(4,4'-dimethoxydithiobenzyl) nickel; and combinations thereof.

[0017] The near infrared absorbing dye 130 may be present in the ink 100 in an amount ranging from about 5 wt.% to about 15 wt.% relative to the total weight of the ink 100. In an aspect, the near infrared absorbing dye 130 may be present in the ink 100 in an amount ranging from about 7 wt.% to about 13 wt.% relative, for example, from about 9 wt.% to about 1 1 wt.% relative to the total weight of the ink 100.

[0018] In an aspect, the near infrared absorbing dye 130 may be present as a layer on the white-colored inorganic pigment 120. For example, the near infrared absorbing dye 130 may partially or may completely surround the white-colored inorganic pigment 120.

[0019] The ink 100 may include a carrier 1 10, such as a clear carrier or clear resin. By way of non-limiting examples, the carrier 1 10 may be polyvinyl alcohol, polyvinyl acetate polyvinylpyrrolidone, poly(ethoxyethylene), poly(methoxyethylene), poly(acrylic) acid, poly(acrylamide), poly(oxyethylene), poly(maleic anhydride), hydroxyethyl cellulose, cellulose acetate,

poly(sacchrides) such as gum arabic and pectin, poly(acetals) such as polyvinylbutyral, polyvinyl halides) such as polyvinyl chloride and polyvinylene chloride, poly(dienes) such as polybutadiene, poly(alkenes) such as

polyethylene, poly(acrylates) such as polymethyl acrylate, poly(methacrylates) such as poly methylmethacrylate, poly(carbonates) such as poly(oxycarbonyl oxyhexamethylene, poly(esters) such as polyethylene terephthalate,

poly(urethanes), poly(siloxanes), poly(sulphides), poly(sulphones),

poly(vinylnitriles), poly(acrylonitriles), poly(styrene), poly(phenylenes) such as poly(2,5 dihydroxy-1 ,4-phenyleneethylene), poly(amides), natural rubbers, formaldahyde resins, other polymers and mixtures of polymers and polymers with solvents.

[0020] A printed medium 200, as shown in FIG. 2, may include a surface 210 including a pattern of indicia 220 in which the pattern of indicia 220 includes an ink 100 including a white-colored inorganic pigment 120, a near infrared absorbing dye 130, and a carrier 1 10 as discussed herein. In an aspect, the surface may 210 be a white-colored paper or a whiteboard. The pattern of indicia 220 may be a dot array applied to the surface 210 with the ink 100. Because the ink 100 is visibly white-colored, the ink 100 may not be visible to the human eye when applied to the surface 210, i.e., the ink 100 may blend in with the surface 210 and may be aesthetically appealing. However, the ink 100 may appear black in color to an electro-optical pen or similar reader due to the presence of the near infrared absorbing dye 130 in the ink 100.

[0021] After the ink 100 is applied to a white-colored surface 210, the ink 100 may be cured using ultraviolet light, visible light, infrared, electron beam, or the like. Curing may proceed in an inert or ambient atmosphere. In an aspect, the curing may utilize an ultraviolet light source having a wavelength of about 395 nm. The ultraviolet light source may be applied to the ink 100 at a dose ranging from about 200 mJ to about 1000 mJ, for example ranging from about 250 mJ to about 900 mJ, and as a further example from about 300 mJ to about 850 mJ. Some of the near infrared absorbing dyes 130 may be sensitive to high exposure to ultraviolet light so other drying mechanisms may be used.

[0022] The cured ink 100 may be tuned to a neutral white-color hue using a colorimeter.

[0023] With reference now to FIG. 3, there is shown a flow diagram of an example method 300 of making an ink 100. In the method 300, at block 310, a near infrared absorbing dye 130 may be dissolved in a solvent to form a solution. At block 320, a white-colored inorganic pigment 120 may be added to the solution. In addition, at block 330 the solution may be mixed to evenly coat the white-colored inorganic pigment 120 with the near infrared absorbing dye 130. Moreover, at the block 340, the coated pigment may be removed from the solution. Further, at block 350, the coated pigment may be combined with a carrier 1 10 to form the ink 100.

[0024] The solvent may include water, alcohol, tetrahydrofuran, methyl ethyl ketone, methanol, isooctane, hexanes, toluene, dichloromethane, ethylene chloride, dimethylsulfoxide, diethyl ether, ethyl acetate, dioxane,

hexachlorobenzene, N-methyl-2-pyrrolidone, dimethyl formamide, nitrobenzene, carbon disulfide, or the like.

[0025] Although described specifically throughout the entirety of the instant disclosure, representative examples of the present disclosure have utility over a wide range of applications, and the above discussion is not intended and should not be construed to be limiting, but is offered as an illustrative discussion of aspects of the disclosure.

[0026] What has been described and illustrated herein is an example of the disclosure along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the disclosure, which is intended to be defined by the following claims - and their equivalents - in which all terms are meant in their broadest reasonable sense unless otherwise indicated.

Claims

What is claimed is:

1 . An ink, comprising:

a white-colored inorganic pigment;

a near infrared absorbing dye; and

a carrier.

2. The ink of claim 1 , wherein the white-colored inorganic pigment is present in the ink in an amount ranging from about 15 wt.% to about 65% wt.% relative to the total weight of the ink.

3. The ink of claim 1 , wherein the white-colored inorganic pigment includes titanium oxides, zinc oxide, zinc sulphides, zirconium oxide, silicon dioxide, aluminum oxides, white lead, basic lead sulfate, barium sulfate, calcium carbonate, calcium silicate, kaolin clay, talc, silica, and combinations thereof.

4. The ink of claim 1 , wherein the near infrared absorbing dye is present in the ink in an amount ranging from about 5 wt.% to about 15% wt.% relative to the total weight of the ink.

5. The ink of claim 1 , wherein the near infrared absorbing dye is visibly transparent and infrared opaque to reduce the reflection in the near infrared wavelength relative to the visible wavelengths.

6. The ink of claim 1 , wherein the near infrared absorbing dye is color neutral.

7. The ink of claim 1 , wherein the white-colored pigment and the near infrared absorbing dye may be a single compound.

8. The ink of claim 1 , wherein the ink is white-colored.

9. The ink of claim 1 , wherein the near infrared absorbing dye is present as a layer on the white-colored inorganic pigment.

10. The ink of claim 9, wherein the near infrared absorbing dye completely surrounds the white-colored inorganic pigment.

1 1 . A printed medium, comprising:

a surface including a pattern of indicia, wherein the pattern of indicia includes an ink including a white-colored inorganic pigment, a near infrared absorbing dye, and a carrier.

12. The printed medium of claim 1 1 , wherein the surface is a white-colored paper.

13. The printed medium of claim 1 1 , wherein the surface is a whiteboard.

14. A method of making ink, comprising:

dissolving a near infrared absorbing dye in a solvent to form a solution; adding to the solution a white-colored inorganic pigment;

mixing the solution to evenly coat the white-colored inorganic pigment with the near infrared absorbing dye; and

removing the coated pigment from the solution.

15. The method of claim 14, wherein the solvent includes water, alcohol, tetrahydrofuran, methyl ethyl ketone, methanol, isooctane, hexanes, toluene, dichloromethane, ethylene chloride, dimethylsulfoxide, diethyl ether, ethyl acetate, dioxane, hexachlorobenzene, N-methyl-2-pyrrolidone, dimethyl formamide, nitrobenzene, and carbon disulfide.