WO2006076063A1

WO2006076063A1 - Improved lightfast, trichromatic black dye mixtures

Info

Publication number: WO2006076063A1
Application number: PCT/US2005/038608
Authority: WO
Inventors: Lawrence M. Krueger; Thomas Sommermann
Original assignee: Lanxess Deutschland GmbH; Lanxess Corp
Current assignee: Lanxess Deutschland GmbH; Lanxess Corp
Priority date: 2005-01-10
Filing date: 2005-10-27
Publication date: 2006-07-20
Anticipated expiration: 2007-07-10
Also published as: TW200639219A; WO2006076365A1

Abstract

A composition comprising a trichromatic dye mixture containing a C.I. Direct Red 239 component, a C.I. Direct Yellow 133 component, and a C.I. Direct Blue 273 component. The invention also relates to inks made with the above-described mixture, and methods of making and using the mixture.

Description

IMPROVED LIGHTFAST. TRICHROMATIC BLACK DYE MIXTURES

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.

InkJet 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 inkjet 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 0 693 537, 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 lightfastness 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 lightfastness on substrates.

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

SUMMARY

The invention relates to a composition comprising a dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III; where Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

R in the above-mentioned formulae is selected from the group consisting of 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 another embodiment, the invention relates to a method for dyeing substrates with the above-described mixture. These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. - A -

DESCR1PT1ON

The invention is based on the discovery that by using a certain combination of dyes, it is now possible to make 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 how the unpredictable, synergistic nature of different dye mixtures affect 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: Formula I (C.I. Direct Red 239), Formula Il (C.I. Direct Yellow 133), and Formula III (C.I. Direct Blue 273),

Formula (I)

Formula (II)

Formula (III)

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

The Direct Red 239 is a known anionic dye and commercially available. The Direct Red 239 is a required component in the mixture that is essential with the Direct Yellow 133 to form the black. Generally, the Direct Red 239 has the Formula I

Formula I in which R is selected from trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof.

The Direct Red 239, when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness to paper. In one embodiment, the Direct Red 239 has a solids content ranging from 1 to 20 or from 1 to 10 weight % solids. In another embodiment, the Direct Red 239 has a solids content containing 12.2wt% color solids.

The Direct Yellow 133 is a known anionic dye and commercially available. The Direct Yellow 133, when mixed with the Direct Red 239 and Direct Blue 273 components, forms the black.

Generally, the Direct Yellow 133 is of the Formula II:

Formula (II)

in which R is selected from trialkanolammonium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof.

The Direct Yellow 133, when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness to paper. In one embodiment, the Direct Yellow 133 has a solids content ranging from 1 to 20 or from 1 to 10 weight % solids. In another embodiment, the Direct Yellow 133 has a solids content containing 11.0 weight % color solids.

The Direct Blue 273 is a known anionic dye and commercially available. Without being bound by theory, it is believed that the Direct Blue 273 gives the good lightfastness and adds depth of color. Generally, the Direct Blue 273 is of the Formula III:

Formula

in which R is selected from trialkanolammonium, alkyldialkanol- ammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof.

The Direct Blue 273, when used in accordance to the invention, results in a trichromatic black dye composition that imparts improved lightfastness to paper. In one embodiment, the Direct Blue 273 has a solids content ranging from 1 to 20 or from 1 to 10 weight % solids. In another embodiment, the Direct Blue 273 has a solids content containing 11 weight % color solids.

The aqueous dye mixture contains dye components 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 1.0 to 10.0 weight %, or from 3.0 to 5.0 weight % of Formula (I), from 1.0 to 15.0 weight %, or from 5.0 to 7.0 weight % of Formula (II), and from 10 to 50 weight %, or from 15 to 25 weight % of Formula (III) 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 those with molecular weight < 200 g/mole. Examples of those solvents that are particularly suitable for use are: methanol, ethanol, propanol; ethylene-, propylene-, diethylene-, thiodiethylene-, and dipropyieneglycol; butanediol; 2-hydroxypropionitrile, _ _.

- 8 -

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, N₁N'- dimethylolpropyleneurea, dimethylsulfoxide, dimethylsulfone, sulfolane, isopropanol, polyethyleneglycol, including mixtures thereof.

The trichromatic black dye mixture is generally made by blending appropriate amounts of dyes having Formula (I), Formula (II), and Formula (III) in sufficient amounts under conditions that produce a trichromatic dye composition, which when used to print paper, produces printing with improved or comparable lightfastness, as 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 dyes of Formula (I), Formula (II) and Formula (III) are blended vary, depending on factors such as available equipment, product requirements, and the like. Below are illustrative conditions. The pH of the blend, for instance, can vary, depending on application. In one embodiment, the pH is 7, and in another embodiment, the pH ranges from 7 to 8. The pH of the trichromatic black dye mixture from the invention can be from 8 to 10, and preferably from 9 to 10. Separation and purification methods can be used in making the trichromatic black dye composition. For instance, three 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, an aqueous mixture of the three dyes described in Formulas (I), (II), and (III), can be formed from either powders, liquids, or mixtures thereof, of the three colorants. This mixture is then purified 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 2 weight %, or less than 1 weight %, or less than 0.2 weight %, based upon the dye mixture.

The desalinated liquid is then 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 dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III of the invention can be used as a component to make an ink that is useful in inkjet systems. As such, 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 dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III; where Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

(2) a solvent component (3) a surfactant component.

Specific ink formulations are discussed in the following passages. A specific ink formulation, for instance, can include trichromatic dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III 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 mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III: 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:

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

Ethanolamine, Surfactants 0.1 Surface tension control, wetting

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

UV Absorbers, Antioxidant light stability, storage stability

* trichromatic black dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III.

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 dye of Formula I, (2) a dye of Formula II, and (3) a 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%

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%

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%

The trichromatic black dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III of the invention can be added to the above-mentioned formulations in various amounts, depending on the application. Generally, the amount can range from 1 to 5 wt% or 10wt%. Percentages listed above are in 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 with molecular weight < 200 g/mole. Examples of those solvents that are particularly suitable for use are: methanol, ethanol, propanol; ethylene-, propylene-, diethylene-, thiodiethylene-, and dipropyleneglycol; butanediol; 2-hydroxypropionitrile, pentamethyleneglycol, ethyleneglycolmonoethyl-, propyl- and butylether, ethylenediglycolmonoethylether, triethyleneglycoimonobutylether, 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-i-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, including mixtures thereof.

Suitable surfactants include nonionic surfactants having an HLB that is more than 5, e.g. 8 or 13. Examples of suitable surfactants include 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. Generally, the water content of the ink can range from 50 to 75 wt% or 90wt%. Percentages listed above are in weight %.

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- one, 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, and 2,6-dimethyl-/77-dioxan-4 ol acetate. Imidacloprid, tebuconazole, 1 ,2-benzisothiazolin-3-one, a mixture of benzylhemiformal and 2-octyl-2H-isothiazol-3-one, and a mixture of 2-methyl-4-isothiazolin- 3-one and 5-chloro-2-methyl-4-isothiazolin-3-one may be obtained from LANXESS Corporation, Pittsburgh, PA. 2,6-dimethyl-/7?-dioxan-4 ol acetate can be obtained from Dow Chemical under the mark BIOBAN ™ DXN

An ink of the invention is made by formulating the trichromatic dye mixture containing (1 ) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III and blending the trichromatic dye mixture with the suitable components. In another embodiment, the invention provides an ink cartridge that includes an ink container portion that contains the trichromatic black dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III. 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 containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III.

Generally, such an ink set will 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 containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III. In use, the trichromatic dye mixture containing (1 ) a dye of Formula

I, (2) a dye of Formula II, and (3) a 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. The magnitude of this DE (a measure of the lightfastness which is the dye's resistance to fading on paper or other media) that is observed depends on the substrate that is being used. When an ink containing the trichromatic black dye mixture is used, the ink is applied to an appropriate medium by using drop-on demand ink jet technology (Thermal inkjet, Bubble-Jet, Piezo inkjet), to develop the letter character or graphic desired.

The invention provides previously unavailable advantages. The resulting jet-black dye which, when applied to varying media such as paper, glass, metal, plastic, and textiles, exhibits excellent lightfastness properties and acceptable ozone fastness. Inks of the invention also provide excellent lightfastness and acceptable ozone fastness.

The invention is further described in the following 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 (E¹ ₁ = 70), 17 parts C.I. Direct Yellow 133 (E¹i = 60), and 18 parts C.I. Direct Red 239 (E¹i = 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 E\ 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.

E\ = 7 E¹ _{1 =} 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-methylbenzoic acid (E¹ ₁ = 120), and 7 parts C.I. Direct Red 239 (E\ = 100), was dissolved in 100 parts of deionized water. Undesired salts were removed by ultrafiltration 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, E¹i = 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 concentrations, 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 E\ value of 40.

EXAMPLE 8 (COMPARATIVE EXAMPLE)

Two ink mixtures suitable for inkjet application at two different concentrations, E¹i = 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.

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.

10 Results:

Optical density (OD) of the print-outs was determined (high value = good). After light fastness testing, DE* values were determined (low value = good). Results for E¹i = 7 are summarized in Table 1, for E¹i = 15 in table 2, with irradiation at 320 nm (Atlas Alpha) for 24 h.

15 Table !

Table 2.

The 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

10 not be limited to the description of the versions contained therein.

Claims

WHAT 18 CLAIMED IS:

1. A composition comprising a trichromatic dye mixture containing (1) a dye of Formula I₁ (2) a dye of Formula II, and (3) a dye of Formula III; wherein Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

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

2. The composition of Claim 1 , wherein the compound of

Formula (I) is in an amount ranging from 1 to 10 weight %. 3. The composition of Claim 1 , wherein the compound of

Formula (II) is in an amount ranging from 1 to 15 weight %.

4. The composition of Claim 1 , wherein the compound of Formula (III) ranges from 10 to 50 %.

5. The composition of Claim 1 , wherein the compound of Formula (I) ranges from 1 to 10%, the compound of Formula (II) ranges from 1 to 15%, and the compound of Formula (III) ranges from 10 to 50 weight %.

6. The composition of Claim 1 , wherein the composition further comprises water. 7. An ink comprising:

(a) a trichromatic dye containing (1 ) a dye of Formula I₁ (2) a dye of Formula II, and (3) a dye of Formula 111, wherein Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

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

(b) an organic solvent component,

(c) a surfactant component.

7. The composition of Claim 6, wherein the organic solvent component is present in an amount ranging from 10 to 60 weight %.

8. An inkjet printing method comprising ejecting droplets of an ink onto a substrate, wherein the ink comprises:

(a) a trichromatic dye component containing (1 ) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III, wherein Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

(b) an organic solvent component.

10. The method of Claim 9, wherein the substrate is selected from the group consisting of paper substrates, textile substrates, plastic substrates, metal substrates, glass substrates, and combinations thereof. 11. The method of Claim 9, wherein the organic solvent component is selected from the group consisting of 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, D-caprolactam, N-methylcaprolactam, butyrolactone, urea, tetramethylurea, 1 ,3-dimethyl-2-imidazolidinone, N₁N'- dimethylolpropyleneurea, dimethylsulfoxide, dimethylsulfone, sulfolane, isopropanol, polyethyleneglycol, and mixtures thereof. 12. An ink set comprising:

(a) a yellow ink component,

(b) a magenta ink component

(c) a cyan ink component

(d) and a black ink containing a trichromatic dye component containing (1) a dye of Formula I₁ (2) a dye of Formula II, and (3) a dye of Formula III, wherein Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

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

13. A method comprising treating a substrate selected from the group consisting of paper substrates, glass substrates, metal substrates, plastic substrates, and textile substrates with a trichromatic black dye mixture containing (1) a dye of Formula I, (2) a dye of Formula II, and (3) a dye of Formula III; wherein Formula (I) is:

Formula (I)

Formula (II) is

Formula (II)

and Formula (III) is

Formula (III)

wherein R is selected from the group consisting of trialkanolammo nium, alkyldialkanolammonium, tetraalkylammonium, ammonium, lithium, sodium, potassium, and mixtures thereof 14. The method of Claim 13, wherein the compound of Formula

(I) is in an amount ranging from 1 to 10 wt %.

15. The method of Claim 13, wherein the compound of Formula

(II) is in an amount ranging from 1 to 15 wt %.

16. The method of Claim 13, wherein the compound of Formula (III) is in an amount ranging from 10 to 50 wt. %.

17. The method of Claim 13, wherein the compound of Formula (I) ranges from 1 to 10%, the compound of Formula (II) ranges from 1 to 15 wt %, and the compound of Formula (III) ranges from 10 to 50 wt %. 18. A substrate dyed with the method of Claim 13.