WO2006076365A1

WO2006076365A1 - Improved lightfast, trichromatic black dye mixtures

Info

Publication number: WO2006076365A1
Application number: PCT/US2006/000824
Authority: WO
Inventors: Lawrence M. Krueger; Thomas Sommermann
Original assignee: Lanxess Corporation; Lanxess Deutschland Gmbh
Priority date: 2005-01-10
Filing date: 2006-01-10
Publication date: 2006-07-20
Also published as: TW200639219A; WO2006076063A1

Abstract

A trichromatic dye mixture containing a red dye component, a yellow dye component, and a blue dye component that provides improved lightfastness. The invention also relates to inks made with the above-described mixture, and methods of making and using the dye mixture.

Description

_ _

IMPROVED LIGHTFAST, TRICHROMATIC BLACK DYE MIXTURES

CROSS REFERENCES AND RELATED APPLICATIONS

The application claims priority from U.S. Provisional Application Serial Number 60/642,596 entitled "NEW LIGHTFAST, TRICHROMATIC BLACK AZO INKJET DYE", filed January 10, 2005, herein incorporated by reference in its entirety.

BACKGROUND The present invention relates to lightfast trichromatic black dye compositions, to inks containing such compositions, and to processes using such inks in printing and imaging technologies, particularly ink jet printing.

Lightfastness is a dye property which indicates its resistance to fading due to light exposure. One means of quantifying this property is to measure the change in color of a dye after the dye has been applied to a medium such as paper through the use of inkjet printing and then exposed to light.

Ink jet printing is a non-impact printing technique which involves ejecting droplets of ink from a fine nozzle directly onto a substrate (paper, textiles, plastic, metal, glass). Inks used in ink jet printers have to meet a variety of criteria, such as good filterability, low salt content, high surface tension, and long-term storage stability, in order to provide printed images which have good optical density, lightfastness, and ozonefastness.

For dye-based black inks, various dyes like food black dyes, naphthol direct azo dyes and reactive dyes have widely been known to-date. A typical example of food black dyes includes C.I. Food Black 2, described in JP-A 59- 093 766. However, food dyes give images with poor light fastness. Moderate lightfastness can be achieved using black naphthol direct azo dyes like C.I. Direct Black 168 or C.I. Direct Black 51, as described in EP-A 0 564 146. Reactive black dyes, especially C.I. Reactive Black 31, are described in EP-A 0693537, and give images with high lightfastness.

A common disadvantage of using black dyes in an ink jet ink is that a neutral black shade can not easily be obtained. All inks containing black dyes need shading to get a neutral black printout. Furthermore, it is sometimes - - impossible to obtain the desired shade for special applications with black dyes.

In these cases, trichromatic black compositions of yellow, red and blue dyes are advantageous because almost any shade can be easily adjusted by varying the component ratio. A typical example of a trichromatic composition of yellow and blue stilbene disazo dyes with a red azo dye is described in US- A 4 118 182.

However, known trichromatic compositions show inferior Hghtfastness compared to naphthol direct azo dyes like C.I. Direct Black 168, Direct Black 195, or reactive dyes such as C.I. Reactive Black 31.

For the foregoing reasons, there is an ongoing need to develop trichromatic black compositions that impart improved Hghtfastness on substrates.

For the foregoing reasons, there is an ongoing need to develop an imprpved lightfast trichromatic mixture with high optical density for the use in ink jet printing inks.

SUMMARY

The invention relates to a composition comprising a trichromatic dye mixture containing (1 ) a red dye of Formula (Ia, Ib, Ic, and Id), (2) a yellow dye of Formula (II), and (3) a blue dye of Formula (III); where Formula (Ia) is:

Formula (Ia)

Formula (Ib) is: - -

Formula (Ib)

Formula (Ic) is:

Formula (Ic)

Formula (Id) is:

Formula (Id)

Formula (II) is - -

Formula (II)

and Formula (III) is

Formula (III)

R in the above-mentioned formulae is either trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof.

In another embodiment, the invention relates to an ink made with such a mixture.

In a preferred embodiment, the disclosed ink is used in a method for inkjet printing.

In another embodiment, the invention relates to a method for dyeing substrates with the above-described mixture. Further embodiments include an ink set in which the black of the present invention is packaged with yellow, magenta and cyan dyes.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. - -

DESCRIPTION

The invention is based on a trichromatic dye composition that exhibits improved lightfastness on a variety of substrates, as compared to certain ordinarily trichromatic dye compositions and certain monochromatic dye compositions. The discovery is unexpected, in part, because of the unpredictable, synergistic nature of dye mixtures affect on the lightfastness of products containing such dye mixtures.

Other than in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term "about." Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

The trichromatic black dye composition of the invention includes a mixture of three dyes having the following formulae: A red dye of Formula Ia (G.I. Direct Red 239), Ib (C.I. Direct Red 254), Ic (C.I. Direct Red 75), or Id (C.I. Direct Red 212), where Formula (Ia) is;

Formula (Ia)

Formula (Ib) is:

- -

Formula (Ib)

Formula (Ic) is:

Formula (Ic)

and Formula (Id) is:

Formula (Id)

a Yellow Dye of Formula Il (C.I. Direct Yellow 133),

Formula Il - -

and a Blue Dye of Formula III (C.I. Direct Blue 273)

Formula (III)

The R substituents are cations and can be selected from trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium and potassium and combinations thereof.

The red dyes of formula (Ia), (Ib), (Ic) and (Id) are known anionic dyes and commercially available. The red dye is a component in the mixture with the yellow and blue dye to form the presently claimed black dye.

The red dyes when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness.

In one embodiment, the Red Dyes have a solids content ranging from about 1 to about 20 weight % or from about 1 to about 10 weight % solids.

In another embodiment, the red dyes have a solids content containing about 12.2 weight % color solids. The yellow dyes of formula (II) are known anionic dyes and commercially available. The yellow dye, when mixed with red and blue dye components forms the presently claimed black dye.

The yellow dye, when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness. In one embodiment, the yellow dye has a solids content ranging from about 1 to about 20 wieght % or from about 1 to about 10 weight % solids.

In another embodiment, the yellow dye has a solids content containing about 11.0 weight % color solids. The blue dyes of Formula (III) are known anionic dyes and commercially _ _

available. Without being bound by theory, it is believed that the blue dye component gives the improved lightfastness and adds depth of color to the blacK dye composition of the present invention.

The blue dye, when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness.

In one embodiment, the blue dye has a solids content ranging from about 1 to about 50 weight % solids.

In another embodiment, the blue dye has a soljds content containing about 25 weight % color solids. The aqueous dye mixture contains dye components described above in sufficient amounts such that when the dye mixture is used in an ink to print paper, the dye on the paper exhibits improved lightfastness.

In one embodiment, the aqueous dye mixture contains from about 1.0 to about 10.0 weight %, or from about 3.0 to about 5.0 weight % of red dye, from about 1.0 to about 15.0 weight %, or from about 5.0 to about 7.0 weight % of yellow dye, and from about 10 to 50 weight %, or from about 15 to about 25 weight % of blue dye with the remainder as water. This mixture is the dye concentrate which is then used as the colorant in the ink formulation.

Solvents, which are miscible with water, can be used with the aqueous dye mixture of the invention. These can be alcohols and their ethers or esters, carbonamides, ureas, sulfoxides and sulfones. Particularly usefule are those solvents with a molecular weight less than 200 g/mole. Examples of solvents particularly suitable for use in the present invention are: methanol, ethanol, propanol; ethylene-, propylene-, diethylene-, thiodiethylene-, and dipropyleneglycol; butanediol; 2-hydroxypropionitrile, pentamethyleneglycol, ethyleneglycolmonoethy]-, propyl- and butylether, ethylenediglycolmonoethylether, triethyleneglycolmonobutylether, butylpolyglycol, formamide, triethyleneglycol, 1,5-pentanediol, 1 ,3,6- hexanetriol, acetic acid-2-hydroxyethylester, acetic acid-2(2-hydroxy)- ethylester, glycerin, glycolacetate, 1 ,2-dihydroxypropane, 1-methyoxy-2- propanol, 2-methoxy-1 -propanol, N.N-dimethylformamide, pyrrolidone, N- methylpyrrolidinone, -caprolactam, N-methylcaprolactam, butyrolactone, urea, tetramethylurea, 1,3-dimethyl-2-imidazolidinone, N₁N'- _ _

dimethylolpropyleneurea, dimethylsuifoxide, dimethylsulfone, sulfolane, isopropanol, polyethyleneglycol, and mixtures thereof.

The trichromatic black dye mixture is generally made by blending appropriate amounts of red dye having Formula (Ia, Ib, Ic or Id), yellow dye having Formula (II) and bule dye having Fprmula (III) in sufficient amounts and under conditions that produce a trichromatic dye composition, which when used to print paper, produces printing with improved or comparable lightfastness, when compared to naphthol direct azo dyes like C.I. Direct Black 168, Direct Black 195, or reactive dyes such as C.I. Reactive Black 31. The conditions at which the red dyes of Formula (Ia, Ib, Ic or Id), yellow dyes of Formula (II) and blue dyes of Formula (III) are blended vary, depending on factors such as available equipment, product requirements, and the like, and are known by those of ordinary skill in the art. Below are illustrative conditions. In one embodiment, the dye composition described herein is mixed at pH of about 7 to about 10.

In another embodiment, the pH ranges from about 7 to about 8. The pH of the trichromatic black dye mixture from the invention can be from about 8 to about 10. In a preferred embodiment of the present invention the pH of the dye mixture is from about 9 to about 10.

The trichromatic black dye mixture solutions presented herein can be purified using separation and purification methods known to those familiar in the art. For instance, three examples of purification methods that can be used include: (1) ultrafiltration using a specified membrane to maximize removal of inorganic salts and minimize loss of color, (2) treatment with activated carbon to remove small amounts of surface active agents that negatively affect ink performance, and (3) sub-micron filtration to remove trace amounts of undissolved solids that affect the performance of the ink. In one embodiment, powders, liquids, or mixtures thereof of red dyes of

Formulas (Ia, Ib, Ic and Id), yellow dyes of Formula (II) and blue dyes of Formula (III) combined in an aqueous solution. This mixture is then purified for example by reverse osmosis or ultrafiltration using an appropriate - - membrane to remove undesirable inorganic salts such as sodium- or potassium chloride or sodium- or potassium sulfate. The salt content remaining in the purified liquid is normally less than about 0.2 to about 2 weight %, based upon the total weight of the dye mixture.

The desalinated liquid may then be treated with activated carbon to remove surface active impurities, and subsequently filtered through sub- micron filters to remove small amounts of undissolved material.

The trichromatic dye mixture containing (1) a red dye of Formula (Ia, Ib, Ic and Id), (2) a yellow dye of Formula (II), and (3) a blue dye of Formula (III) of the invention can be used as a component to make an ink that is useful in inkjet systems.

In one embodiment, the invention provides an ink formulation that includes the following components:

(1) a composition comprising a trichromatic black dye mixture containing (1) a red dye of Formula (Ia₁ Ib, Ic and Id), (2) a yellow dye of Formula (H)₁ and (3) a blue dye of Formula (111); where Formula (Ia) is:

Formula (Ia)

Formula (Ib) is:

Formula (Ib) - -

Formula (Ic) is:

Formula (Ic)

Formula (Id) is:

Formula (Id)

Formula (II) is:

Formula (II)

and Formula (III) is: - -

Formula (III)

R in the above-mentioned formulae is either trialkanolammonium, aikyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof;

(2) a solvent; and (3) a surfactant.

A specific ink formulation, for instance, can include trichromatic dye mixture of the present invention and the other components: water, diethylene glycol monobutyl ether, diethylene glycol, glycerine, an acetylene glycol surfactant, triethanolamine, 2-pyrrolidone, EDTA, and a biocide.

Another specific ink formulation can include the following components in addition to the trichromatic black dye composition of the invention: water, ethylene glycol, glycerol, urea, an acetylene glycol ethylene oxide adduct surfactant, and a silicon-containing surfactant. And, another specific ink formulation includes the following components in addition to the trichromatic dye of the present invention: water, trimethylolpropane, 2-pyrrolidone, 1 ,5-pentanediol, a nonionic surfactant, an anionic surfactant, buffer, and EDTA. Dyestuffs can be added in addition to these formulations. In another embodiment, the invention provides the following ink formulation in addition to the trichromatic black dye mixture containing (1) a red dye of Formula (Ia, Ib₁ Ic and Id), (2) a yellow dye of Formula (II), and (3) a blue dye of Formula (III):

Component Wt % Function/Purpose Direct Dyestuff* 2 - 7 Soluble colorant

Distilled Water 50 - 90 main solvent

Glycol, Pyrrolidone, Amine 5 - 20 Anti-clogging, humectant low alcohols, Glycerol ether, 5 - 20 paper penetrant, surface tension glycol ether corrosion inhibitors 0.1 protect surface of printer head

Biocide 0.1 - 0.3 Bactericide

Buffering Agent 0.1 - 0.5 pH control, dye stabilizer

Alginates 0.1 Viscosity control

Ethanofamine, Surfactants 0.1 Surface tension control, wetting

EDTA, Phosphate Sequestration (Ca++, Mg ++)

UV Absorbers, Antioxidant light stability, storage stability

In another embodiment, inks in accordance to the invention can contain the following components in addition to the trichromatic black dye mixture containing (1) a red dye of Formula (Ia, Ib, Ic and Id), (2) a yellow dye of Formula (II), and (3) a blue dye of Formula (III):

Water 39.6%

Diethylene glycol monobutyl ether 10.0%

Diethylene glycol 10.0%

Glycerine 10.0% acetylene glycol surfactant 1.0%

Triethanolamine 1.0%

2-pyrrolidone 2.5%

EDTA 0.01%

Biocide 0.3% or

Water 74.0%

Ethylene glycol 7.0%

Glycerol 8.0%

Urea 5.0% acetylene glycol ethylene oxide adduct surfactant 1.0% silicon-containing surfactant 0.01% or

Water 72.9%

Trimethylolpropane 12.0%

2-pyrrolidone 6.5%

1 ,5-pentanediol 2.0% nonionic surfactant 2.0% anionic surfactant 0.6%

Buffer 0.2% EDTA 0.0075%

(All percentages listed above are in weight %).

The trichromatic black dye mixture of the invention can be added to the above-mentioned formulations in various amounts, depending on the application. Generally, the amount can range from about 1 to about 10 weight %.

Suitable solvents that can be used to make inks suitable for inkjet systems include alcohols and their ethers or esters, carbonamides, ureas, sulfoxides and sulfones; particularly those solvents with molecular weight less than 200 g/mole. Examples of those solvents that are particularly suitable for use in the present invention are: methanol, ethanol, propanol; ethylene-, propylene-, diethylene-, thiodiethylene-, and dipropyleneglycol; butanediol; 2- hydroxypropionitrile, pentamethyleneglycol, ethyleneglycolmonoethyl-, propyl- and butylether, ethylenediglycolmonoethylether, triethyleneglycolmonobutylether, butylpolyglycol, formamide, triethyleneglycol, 1,5-pentanediol, 1 ,3,6-hexanetriol, acetic acid-2-hydroxyethylester, acetic acid-2(2-hydroxy)-ethylester, glycerin, glycolacetate, 1 ,2-dihydroxypropane, 1- methyoxy-2-propanol, 2-methoxy~1 -propanol, N.N-dimethylformamide, pyrrolidone, N-methylpyrrolidinone, -caprolactam, N-methylcaprolactam, butyrolactone, urea, tetramethylurea, 1 ,3-dimethyl-2-imidazolidinone, N,N'- dimethylolpropyleneurea, dimethylsulfoxide, dimethylsulfone, sulfolane, isopropanol, polyethyleneglycol, including mixtures thereof.

Suitable surfactants include nonionic surfactants having an HLB that is more than about 5, more particularly about 8 to about 13. Examples of suitable surfactants include but are not limited to Surfynol™ 440, and Surfynol™ 465, available from Air products. Other suitable non-ionic surfactants will be apparent and known to one of ordinary skill in the art. Also, anionic surfactants can be used, depending on the application. The water content of an ink of the invention can vary, depending on the application.

In one embodiment, the water content of the ink can be from about 50 to about 90 weight % of the total composition _ _

In another embodiment, the water content of the ink can be from about 50 to about 75 weight % of the total composition.

In some embodiments, the ink of the invention can also include other components such as biocides. Examples of suitable biocides include and are not limited to imidacloprid, tebuconazole, 1 ,2-benzisothiazolin-3-oπe, a mixture of benzylhemiformal and 2-octyl-2H-isothiazol-3-one, a mixture of 2- methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one, 2,6- dimethyl-m-dioxan-4 ol acetate and other mixtures thereof.

In another embodiment, the invention provides an ink cartridge that includes an ink container portion that contains the trichromatic black dye mixture of the present invention.

In addition to the above mentioned embodiment, the invention provides an ink set that includes the following components:

(a) a yellow ink component, (b) a magenta ink component

(c) a cyan ink component

(d) and a black ink containing the trichromatic black dye mixture of the present invention.

Such an ink set may include a combination of a first dye ink having a color tone, and a second dye ink having a color tone different from that of the first dye ink, such that at least one of the first and second dye inks in the ink set contains an ink of the trichromatic black dye mixture of the present invention.

In use, the trichromatic dye mixture of the present invention containing (1) a red dye of Formula (Ia, Ib, Ic and Id), (2) a yellow dye of Formula (II), and (3) a blue dye of Formula (III) can be used to color a variety of substrates.

Useful substrates include paper substrates, glass substrates, metal substrates, plastic substrates, and textile substrates.

In one embodiment, as compared to the use of ordinary trichromatic compositions and monochromatic blacks, a paper colored with this dye when exposed to light would exhibit a DE value (a measure of the lightfastness which is the dye's resistance to fading on paper or other media). The magnitude of the observed DE depends on the substrate that is being used. _

When an ink containing the trichromatic black dye mixture presented herein is used, the ink is applied to an appropriate medium by using drop-on demand ink jet technology (For example including but not limited to Thermal inkjet, Bubble-Jet, Piezo inkjet), to develop the letter character or graphic desired.

The invention provides previously unavailable advantages. The trichromatic black dye presented herein when applied to media such as paper, glass, metal, plastic, and textiles, exhibits excellent lightfastness properties and acceptable ozone fastness. The invention is further described in the following non-limiting illustrative examples in which all parts and percentages are by weight unless otherwise indicated.

EXAMPLES

EXAMPLE 1

A mixture of 55 parts C.I. Direct Blue 273 (E¹i = 70), 17 parts C.I. Direct Yellow 133 (E¹ _Λ = 60), and 18 parts C.I. Direct Red 239 (E¹ _I = 100), was dissolved in 10 parts of deionized water, where E¹i is defined as the maximum absorbance of an aqueous solution of 1 g of material diluted with water to 100 mL multiplied by 10,000. Undesired salts were removed by ultrafiltration using an appropriate membrane and deionized water, and then concentrated to an end volume of 75 parts. 1.0 part of activated carbon was added to the dye solution. The mixture was stirred for 1 hour and clarified to remove the carbon, followed by cascade filtration ending with a filter pore size of 0.2 micron. The total dye content in this solution was 17 weight % with an E¹i value of 50.

EXAMPLE 2 Two ink mixtures suitable for inkjet application at two different concentrations, E¹i = 7 and E¹i = 15, were prepared using the following formulations and filtered through a cellulose nitrate membrane with a pore size of 0.2 micron prior to use. - -

E¹, = 7 E¹! = 15

Dye liquid from Example 1 7.1 parts 15.2 parts

Deionized water 65.6 parts 57.5 parts

1 ,5-pentanediol 15.0 parts 15.0 parts polyethyleneglycol 200 10.0 parts 10.0 parts

N-methylpyrrolidine 2.0 parts 2.0 parts

Surfynol 465 0.1 parts 0.1 parts

Preventol^® BIT-20 0.2 parts 0.2 parts The formulated ink was added to a Hewlett-Packard HP 51645 black cartridge and applied to the following media: TCF Special Copy Paper (80 g/m²), HP Bright White InkJet Paper, HP Premium Paper, HP Premium High- Gloss Film Paper. The prints were dried, exposed to light at 290 nm (Atlas Suntest) and at 320 nm (Atlas Alpha) for 12 and 24 hrs.

EXAMPLE 3 (COMPARATIVE EXAMPLE)

A trichromatic composition according to U.S. Pat. No. 4,118,182, consisting of 63 parts of a blue compound prepared from coupling diazotized flavonic acid with a mixture of H acid and gamma acid (E¹i = 125), 30 parts of a yellow compound prepared from coupling diazotized flavonic acid with 2- hydroxy-3-methylbenzσic acid (E¹1 = 120), and 7 parts C.I. Direct Red 239 (E¹ _! = 100), was dissolved in 100 parts of deionized water. Undesired salts were removed by ultrafiltratioh using an appropriate membrane and deionized water, and then concentrated to an end volume of 100 parts. 1.5 parts of activated carbon was added to the dye solution. The mixture was stirred for 1 hour and clarified to remove the carbon, followed by cascade filtration ending with a filter pore size of 0.2 micron. The total dye content in this solution was 30 weight % with an E¹i value of 85.

EXAMPLE 4 (COMPARATIVE EXAMPLE)

Two ink mixtures suitable for inkjet application at two different concentrations, E¹ _! = 7 and E¹i = 15, were prepared using the formulations from Example 3 and filtered through a cellulose nitrate membrane with a pore size _ _

of 0.2 micron prior to use.

The formulated ink was added to a Hewlett-Packard HP 51645a black cartridge and applied to the following media: TCF Special Copy Paper (80 g/m²), HP Bright White InkJet Paper, HP Premium Paper, HP Premium High- Gloss Film Paper. The prints were dried, exposed to light at 290 nm (Atlas

Suntest) and at 320 nm (Atlas Alpha) for 12 and 24 hrs.

EXAMPLE 5 (COMPARATIVE EXAMPLE)

A desalinated, carbon-treated and 0.2 micron filtered solution of C.I. Direct Black 168 was prepared as described in Example 1. The total dye content in this solution was 25 weight % with an E¹i value of 75.

EXAMPLE 6 (COMPARATIVE EXAMPLE)

Two ink mixtures suitable for inkjet application at two different concen- trations, E¹i = 7 and E¹i = 15, were prepared using the formulations from example 5 and filtered through a cellulose nitrate membrane with a pore size of 0.2 micron prior to use.

The formulated ink was added to a Hewlett-Packard HP51645a black cartridge and applied to the following media: TCF Special Copy Paper (80 g/m²), HP Bright White InkJet Paper, HP Premium Paper, HP Premium High- Gloss Film Paper. The prints were dried, exposed to light at 290 nm (Atlas Suntest) and at 320 nm (Atlas Alpha) for 12 and 24 hrs.

EXAMPLE 7 (COMPARATIVE EXAMPLE) A desalinated, carbon-treated and 0.2 micron filtered solution of C.I.

Reactive Black 31 was prepared as described in example 1. The total dye content in this solution was 13 weight % with an E¹i value of 40.

EXAMPLE 8 (COMPARATIVE EXAMPLE) Two ink mixtures suitable for inkjet application at two different concentrations, E\ = 7 and E¹i = 15, were prepared using the formulations from Example 7 and filtered through a cellulose nitrate membrane with a pore size of 0.2 micron prior to use. - -

Results:

Optical density (OD) of the print-outs was determined (high value = good). After light fastness testing, DE* values were determined (low value =

10 good). Results for E\ - 7 are summarized in Table 1, for E¹i = 15 in table 2, with irradiation at 320 nm (Atlas Alpha) for 24 h. Table 1.

Table 2.

15 _ _

These results clearly show that the trichromatic mixture 2 (invention) is superior to the comparative trichromatic mixture 4 and to the common black dye C.I. Direct Black 168 in terms of light fastness, and can compete with the very lightfast dye C.I. Reactive Black 31. Especially in low concentration, mixture 2 (invention) shows superior optical density.

Although the present invention has been described in detail with reference to certain preferred versions thereof, other variations are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions contained therein.

Claims

- -WHAT IS CLAIMED IS:

1. A composition comprising a trichromatic dye mixture comprising: (1) a red dye;

(2) a yellow dye; and

(3) a blue dye; wherein the red dye is selected from compounds of general Formula (Ia);

Formula (Ia)

Formula (Ib);

Formula (Ib)

Formula (Ic); and

Formula (Ic)

Formula (Id), - -

Formula (Id) the blue dye is selected from compounds of the general Formula (II):

Formula (II)

and the blue dye is selected from compounds of general Formula (III):

Formula (III)

wherein R is selected from the group consisting of trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof.

2. The composition of Claim 1 , wherein the red dye is present from about 1 to about 10 weight %.

3. The composition of Claim 1, wherein the yellow dye is from - - about 1 to about 15 weight % of the total composition.

4. The composition of Claim 1 , wherein the blue dye is from about

10 to about 50 weight % of the total composition.

5. The composition of Claim 1 , wherein the blue dye is from about

1 to about 10 weight %, the yellow dye is from about 1 to about 15 weight %, and the blue dye is from about 10 to about 50 weight % of the total composition.

6. The composition of Claim 1 , further comprising water.

7. The composition of Claim 1 , further comprising a solvent.

8. The composition of Claim 1 , further comprising a surfactant.

9. An ink comprising:

(a) a trichromatic dye containing: (1) a red dye;

(2) a yellow dye; and

(3) a blue dye wherein the red dye is selected from compounds of Formula (Ia),

Formula (Ia)

Formula (Ib), - -

Formula (Ib)

Formula (Ic), and

Formula (Ic)

Formula (Id),

Formula (Id)

the yellow dye is selected from compounds of general Formula (II),

Formula (II) - -

and the blue dye is selected from compounds of general Formula (III),

Formula (III)

wherein R is selected from the group consisting of trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof; (b) an organic solvent; and (c) a surfactant.

10. The composition of Claim 9, wherein the organic solvent is from about 10 to about 60 weight % of the total composition.

11. A method of inkjet printing comprising ejecting droplets of ink onto a substrate, wherein the ink comprises:

(a) a trichromatic dye component containing

(1) a red dye;

(2) a yellow dye; and

(3) a blue dye of wherein the red dye is selected from compounds of general Formula (Ia),

Formula (Ia) - -

Formula (Ib),

Formula (Ib)

Formula (Ic), and

Formula (Ic)

Formula (Id),

Formula (Id)

the yellow dye is selected from compounds of general Formula (II), - -

Formula (II)

and the blue dye is έelected from compounds of general Formula (III)

Formula (111)

wherein R is selected from the group consisting of trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof; and (b) an organic solvent.

12. The method of Claim 11 , wherein the substrate is selected from the group consisting of paper substrates, textile substrates, plastic substrates, metal substrates, glass substrates, and combinations thereof.

13. The method of Claim 11 , wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol; ethylene-, propylene-, diethylene- thiodiethylene-, dipropyleneglycol; butanediol; 2- hydroxypropionitrile, pentamethyleneglycol, ethyleneglycolmonoethyl-, propyl- , butylether, ethylenediglycolmonoethylether, triethyleneglycolmonobutylether, butylpolyglycol, formamide, triethyleneglycol, 1 ,5-pentanediol, 1 ,3,6- hexanetriol, acetic acid-2-hydroxyethylester, acetic acid-2(2-hydroxy)- ethylester, glycerin, glycolacetate, 1 ,2-dihydroxypropane, 1-methyoxy-2- propanol, 2-methoxy-1 -propanol, N,N-dimethylformamide, pyrrolidone, N- - - methylpyrrolidinone, -caprolactam, N-methylcaprolactam, butyrolactone, urea, tetramethylurea, 1,3-dimethyl-2-imidazolidinone, N₁N'- dimethylolpropyleneurea, dimethylsulfoxide, dimethylsulfone, sulfolane, isopropanol, polyethyleneglycol, and mixtures thereof.

14. An ink set comprising:

(a) yellow ink;

(b) magenta ink;

(C) cyan ink component; and (d) black ink, wherein the black ink comprises a trichromatic dye comprising (1) a red dye;

(2) a yellow dye; and

(3) a blue dye, wherein the red dye is selected from compounds of general Formula (Ia),

Formula (Ia)

Formula (Ib),

Formula (Ib)

Formula (Ic), and - -

Formula (Ic)

Formula (Id),

Formula (Id)

the yellow dye is selected from compounds of general Formula (II), and

Formula (II)

the blue dye is selected from compounds of general Formula (III),

- -

Formula (III)

15. A method dyeing a substrate comprising: treating the substrate with a trichromatic dye comprising:

(1) a red dye; (2) a yellow dye; and

(3) a blue dye; wherein the red dye is selected from compounds of general Formula (Ia),

Formula (Ia)

Formula (Ib),

Formula (Ib)

Formula (Ic), and

- -

Formula (Ic)

Formula (Id),

Formula (Id)

the yellow dye is selected from compounds of general Formula (II), and

Formula (II)

the blue dye is selected from compounds of general Formula (III),

Formula (III)

wherein R is selected from the group consisting of trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof, and _ _

wherein the substrate is selected from the group consisting of paper substrates, glass substrates, metal substrates, plastic substrates, textile substrates and combinations thereof.

16. The method of Claim 15, wherein the red dye is from about 1 to about 10 weight % of the total composition.

17. The method of Claim 15, wherein the yellow dye is from about 1 to about 15 weight % of the total composition.

18. The method of Claim 15, wherein the blue dye is from about 10 to about 50 weight. % of the total composition.

19. The method of Claim 15, wherein the red dye is from about 1 to about 10 weight %, the yellow dye is from about 1 to about 15 weight %, and the blue dye is from about 10 to about 50 weight % of the total composition.

20. A substrate dyed with the method of Claim 13.