Dye-based black ink formulations and ink-jet ink sets

Dye-based black ink formulations, ink-jet ink sets, and methods of making a dye-based black ink formulation, are disclosed.

BACKGROUND

The use of inkjet printing systems in offices and homes has grown dramatically in recent years. The growth can be attributed to drastic reductions in cost of inkjet printers and substantial improvements in print resolution and overall print quality. While the print quality has drastically improved, research and development efforts continue toward improving the permanence of inkjet images, particularly on porous media, because this property still falls short of the permanence produced by other printing and photographic techniques. A continued demand in inkjet printing has resulted in the need to produce images of high quality, high permanence, and high durability, while maintaining a reasonable cost. In particular, there is a demand for inkjet printing on porous media that can produce documents and photographs that can kept for long periods of time without fading due to ozone and/or light.

SUMMARY

Briefly described, embodiments of this disclosure include dye-based black ink formulation, ink-jet ink set, and method of making a dye-based black ink formulation, are disclosed. One exemplary dye-based black ink formulation, among others, includes a black dye, wherein the black dye is in an amount from about 0.5 to 5.0 weight percent of the dye-based black ink formulation; a yellow dye, wherein the yellow dye is in an amount from about 0.5 to 4.0 weight percent of the dye-based black ink formulation; a magenta dye, wherein the magenta dye is in an amount from about 0 to 3.5 weight percent of the dye-based black ink formulation; and a cyan dye, wherein the cyan dye is in an amount from about 0 to 4.0 weight percent of the dye-based black ink formulation.

An embodiment of an ink-jet ink set comprises a plurality of colored inks, and a dye-based black ink formulation comprising a black dye, wherein the black dye is in an amount from about 0.5 to 5.0 weight percent of the dye-based black ink formulation; a yellow dye, wherein the yellow dye is in an amount from about 0.1 to 4.0 weight percent of the dye-based black ink formulation; a magenta dye, wherein the magenta dye is in an amount from about 0 to 3.5 weight percent of the dye-based black ink formulation; and a cyan dye, wherein the cyan dye is in an amount from about 0 to 4.0 weight percent of the dye-based black ink formulation.

Another exemplary ink-jet ink set, among others, includes a plurality of colored inks, and dye-based black ink formulation. The dye-based black ink formulation includes a black dye, wherein the black dye is in an amount from about 0.5 to 5.0 weight percent of the dye-based black ink formulation; a yellow dye, wherein the yellow dye is in an amount from about 0.5 to 4.0 weight percent of the dye-based black ink formulation; a magenta dye, wherein the magenta dye is in an amount from about 0.2 to 3.5 weight percent of the dye-based black ink formulation; and a cyan dye, wherein the cyan dye is in an amount from about 0.5 to 4.0 weight percent of the dye-based black ink formulation.

An exemplary method of making a dye-based black ink formulation, among others, includes providing at least one dye from each of the following: a black dye, a yellow dye, a magenta dye, and a cyan dye; mixing the dyes; and forming the dye-based black ink formulation, wherein the black dye is in an amount from about 0.5 to 5.0 weight percent of the dye-based black ink formulation, wherein the yellow dye is in an amount from about 0.5 to 4.0 weight percent of the dye-based black ink formulation, wherein the magenta dye is in an amount from about 0.2 to 3.5 weight percent of the dye-based black ink formulation, and wherein the cyan dye is in an amount from about 0.5 to 4.0 weight percent of the dye-based black ink formulation.

DETAILED DESCRIPTION

Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of synthetic organic chemistry, ink chemistry, media chemistry, and the like, that are within the skill of the art. Such techniques are explained fully in the literature.

Light fastness is defined based on nominal light exposure behind glass before a failure condition (loss in optical density and/or change in hue) is reached. Nominal light exposure is 450 lux per 12 h day. The failure conditions used is 25% dye loss for the black, starting with a black only optical density of 0.6 and 4-ink (CMYK) optical density of 1.5 and or change in hue with time. The light fade is scored on a scale of 1 to 4 where a score of 1 would mean 0-25 yrs of light fade, a score of 2 would mean 26-50 yrs of light fade, a score of 3 would mean 51-75 yrs of light fade, and a score of 4 would mean >75 yrs of light fade.

Ozone fade testing is carried out in a Hampton 903 ozone chamber at a temperature of 25° C., 50% relative humidity and with an ozone concentration of 1 ppm until a failure condition (loss in optical density and/or change in hue) is reached. The failure conditions used is 25% dye loss for the black, starting with a black only optical density of 0.6 and 4-ink (CMYK) optical density of 1.5 and/or change in hue with time. The ozone fade is scored on a scale of 1 to 4 where a score of 1 would mean 0-2 yrs of ozone fade, a score of 2 would mean 3-5 yrs of ozone fade, a score of 3 would mean 6-8 yrs of ozone fade and a score of 4 would mean >9 yrs of ozone fade.

Water resistance is determined using the ISO water resistance testing method ISO/DIS 18935:2004 (E). The waterfastness was scored on a scale of 0-6 where a score of 2 or lower would mean poor water resistance, a score of 3-4 would mean fairly water resistant and a score of 5-6 would indicate good water resistance.

Discussion

Dye-based black ink formulations and ink-jet ink sets including the dye-based black ink formulation are described. The dye-based black ink formulation includes a combination of black dyes, yellow dyes, magenta dyes, and cyan dyes. The dye-based black ink formulation produces black ink that is neutral over a wide media range (e.g., office paper, all-in-one paper, photo paper, semi-gloss paper, HP Office Paper, HP All-In-One Paper, HP Advanced Photo Paper, HP Everyday Photo Paper, semi-gloss, and transparencies), has permanence over long periods of times, and is waterfast. For example, media printed with the dye-based black ink formulation are resistant to ozone fade for at least five years, are resistant to light fade for 50 or more years, and are water resistant, relative to inks made with only black dyes and the like. In particular, media printed with the dye-based black ink formulation have good archival properties when printed on porous media such as, but not limited to, HP Advanced Photo Paper, HP Everyday Photo Paper, semi-gloss.

The dye-based black ink formulation can be printed using an ink dispensing system that includes, but is not limited to, ink-jet technologies and coating technologies, which dispense the ink onto the print medium. Ink-jet technology, such as drop-on-demand and continuous flow ink-jet technologies, can be used to dispense the ink. The ink dispensing system can include at least one ink-jet printhead system (e.g., thermal ink-jet printhead and/or a piezo ink-jet print head) operative to dispense (e.g., jet) the inks through one or more of a plurality of nozzles in a printhead. The printhead system incorporates an array of firing chambers that receive the ink dissolved or dispersed in a liquid vehicle, which are in fluid communication with one or more ink reservoirs.

In an embodiment, the dye-based black ink formulation can be included in a 4-ink ink-jet set including a cyan ink, magenta ink, and yellow ink, where the dye-based black ink formulation is the fourth ink of the set or as the fifth ink in a five-ink ink-jet set which, in addition to the colors has a pigment based black ink. In another embodiment, the dye-based black ink formulation can be included in a 6-ink ink-jet set including cyan ink, magenta ink, yellow ink, light cyan ink, light magenta ink, where the dye-based black ink formulation is the sixth ink of the set or as the seventh ink in a seven ink system where in addition to the colors there is a pigmented black ink. In another embodiment, the dye-based black ink formulation can be included in a 8-ink ink-jet set including cyan ink, magenta ink, yellow ink, light cyan ink, light magenta ink, light gray ink, medium gray ink, where the dye-based black ink formulation is the eighth ink of the set or as the ninth ink in a nine-ink ink-jet set which, in addition to the cyan ink, magenta ink, yellow ink, light cyan ink, light magenta ink, light gray ink, and medium gray ink, has a pigmented black ink.

The term “print media” or “print medium” can include, but is not limited to, a paper substrate, a photobase substrate, a plastic media (e.g., clear to opaque plastic film) substrate, and the like. The print media may include, but is not limited to, a hard or flexible material made from a polymer, a paper, a glass, a ceramic, a woven cloth, or a non-woven cloth material.

The dye-based black ink formulation includes, but is not limited to, a black dye, a yellow dye, a magenta dye, and a cyan dye. In addition, the dye-based black ink formulation includes, but is not limited to, solvents, salts, buffers, biocides, binders, an aqueous solution, and combinations thereof.

In addition, it should be noted that the black dye can include, but is not limited to, trisazo-dyes or tetra azo dyes. In particular, the black dye can include compounds defined by formula 1 and 2 below:

wherein X is SO3Q, where Q is a sodium ion, lithium ion, or a combination thereof, and where n is 1, 2 or 3.

The black dye can be about 0.5 to 5.0 weight % of the dye-based black ink formulation.

The cyan dye can be about 0 to 4.0 weight % of the dye-based black ink formulation.

When the dye-based black ink formulation is printed on media, in particular porous media, the dye-based black ink formulation has black ink neutrality, permanence, and waterfastness. Specific examples of characteristics of embodiments of the present disclosure are provided in the Examples.

As mentioned above, the dye-based black ink formulation can include solvents, salts, buffers, biocides, binders, an aqueous solution, and combinations thereof, which are described in more detail below.

In particular, the solvent can include, but is not limited to, ethoxylated glycerol, 2-methyl-1,3-propanediol; 2-methyl-2,4-pentanediol; 1,5-pentanediol; 2-pyrrolidone; 1-(2-hydroxylethyl)-2-pyrrolidinone; 2-ethyl-2-hydroxymethyl-1,3-propanediol; diethylene glycol; 3-methoxybutanol; and 1,3-dimethyl-2-imidazolidinone. The solvent can also include, but is not limited to, 1,2-hexanediol; 1,2-octanediol; 2,5-dimethyl-3-hexyne-2,5-diol; trimethylol propane, 3-hexnye-2,5-diol; sulfolane; 3-pyridyl carbinol; and other pyrridine derivatives. In addition, the solvents can be added to reduce the rate of evaporation of water in the ink-jet to minimize clogging or other properties of the ink such as viscosity, pH, surface tension, optical density, and print quality.

The solvent can be about 5 to 25 weight % of the dye-based black ink formulation.

The salt can be about 1 to 6 weight % of the dye-based black ink formulation.

Various buffers or pH adjusting agents can also be optionally used in the ink formulation. The buffering agent can include, but are not limited to, hydroxides of alkali metals and amines (e.g., lithium hydroxide, sodium hydroxide, potassium hydroxide, and citric acid); amines (e.g., triethanolamine, diethanolamine, and dimethylethanolamine); hydrochloric acid; and other basic or acidic components which do not substantially interfere with the bleed control or optical density characteristics. In addition, commercially available pH buffers can also be used and are available from Sigma Aldrich (e.g., MES, MOPs, Trizma, Bis-Tris, MOPSO, TES, TAPSO, TEA, TRICINE, BICINE, TAPS, and AMPSO, in the acid or salt form).

The buffers can be about 0.1 to 3 weight % of the dye-based black ink formulation.

Various biocides can be used to inhibit growth of undesirable microorganisms. The biocides can include, but are not limited to, benzoate salts, sorbate salts, commercial products such as NUOSEPT™ (Nudex, Inc., a division of Huls America), UCARCIDE™ (Union Carbide), VANCIDE (RT Vanderbilt Co.), and PROXEL™ (ICI Americas), and other biocides.

The biocides can be about 0.1 to 3 weight % of the dye-based black ink formulation.

Various surfactants can be used in the ink formulation. The surfactant can include, but are not limited to, anionic, non-ionic, and zwitterionic surfactants. The anionic surfactant can include, but is not limited to, sodium or potassium salts of straight chain fatty acids; sodium and potassium salts of coconut oil fatty acids; sodium and potassium salts of tall oil fatty acids; amine salts; acylated polypeptides; linear alkyl benzene sulfonates; higher alkyl benzene sulfonates; benzene; toulene; xylene; cumenesulfonate; lignosulfonates; petroleum sulfonates; N-acyl-n-alkyltaurates; paraffin sulfonates; secondary n-alkanesulfonates; alpha olefin sufonates; sulfosuccnic esters; alkyl naphalene sulfonates; isethionates; sulfuric acid ester salts; sulfated polyoxyethylenated straight-chain alcohols; sulfated triglycerides oils; phosphoric and polyphosphoric acid esters; and perfluorinated anionic surfactants.

The surfactant can be about 0.05 to 3.0 weight % of the dye-based black ink formulation.

As mentioned above, the dye-based black ink formulation can be used in conjunction with one or more color inks in an ink-jet ink set (e.g., 4-ink printing system, 6-ink printing system, and 8-ink printing system). The ink formulation and the one or more color inks can be used in the same printhead or in one or more printheads.

Specific examples of such dyes include the Pro-Jet series of dyes available from Avecia Ltd., including Pro-Jet Yellow I Direct Yellow 86, Acid Red 249, Direct Blue 199, Direct Black 168, and Direct Yellow 132; Aminyl Brilliant Red F-B (Sumitomo Chemical Co.); the Duasyn line of “salt-free” dyes available from Hoechst, such as Reactive Black 31, Direct Yellow 157, Reactive Yellow 37, Acid Yellow 23, Reactive Red 180, Acid Red 52, and Acid Blue 9; mixtures thereof; and the like.

EXAMPLES

Now having described the embodiments of the present disclosure, in general, the following Examples describe some additional embodiments of the present disclosure. While embodiments of present disclosure are described in connection with the following examples and the corresponding text and figures, there is no intent to limit embodiments of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of the present disclosure.

Table 1 provides the performance of different black dyes when used individually at a 4.0 weight % in an ink. The black inks do not provide a neutral black color on printing, do not provide equal to or greater than 5 years of ozone resistance, and do not provide equal to or greater than 50 years of light resistance while displaying good water resistance properties.

TABLE 1Black dye comparison-4% dye load on porous media. Light fade andozone fade based on a arbitrary scale of 1-4 and water fastness ona scale of 1-5Ex Black 10Formula 2Ex Black 16ColorBlueBlueReddish blueLight Fade244Ozone132Water Fastness513L*min5.814.76.98Chrom11.624.68.1

Table 2 provides examples of blending dyes. The dyes listed in Table 2 can be mixed with black dyes and one another to increase light fade, ozone fade, and water fastness. The color dyes chosen for blending are selected to compensate for the performance gaps in the black dye

Table 3 provides performance of black inks made by blending a suitable black dye such as Experimental Black 16 with one or more or more color dyes (C,M,Y) to enhance color neutrality, light fade, ozone fade, and waterfastness.

Table 4a provides an illustrative embodiment of an ink formulation of the present disclosure. The use of the black dye Experimental Black 10 in a blend with Y104 and Experimental Magenta 1 provides good color neutrality and waterfastness properties and acceptable light fade (Table 4b). Images printed with this ink however, are not resistant to ozone for 5 or more years thus demonstrating the importance of the black dye performance in blended black inks.

Table 5a provides an illustrative embodiment of an ink formulation of the present disclosure. The use of the black dye Experimental Black 16 in a blend with Y104 and Experimental Magenta 1 provides good color neutrality and waterfastness properties as well as good light fade and ozone fade properties (Table 5b), thus demonstrating the importance of the black dye performance in blended black inks.

Table 6a provides an illustrative embodiment of an ink formulation of the present disclosure. In this example Experimental Black 16 is blended with a yellow dye to provide an ink with a neutral black color, good waterfastness, light fade and ozone fade properties (Table 6b).

Table 7a provides an illustrative embodiment of an ink formulation of the present disclosure. In this example the black dye based on formula 2 is blended with a yellow dye Y1 04 and Experimental Magenta 1. This blend results in an ink that do not provide as neutral black inks as in examples 5 and 6 but they have excellent light fade (Table 7b). The images printed with this ink have better ozone fade than the ink in Example 4 however, it does not meet or exceed the performance of the inks in Examples 5 and 6.

Many variations and modifications may be made to the above-described embodiments. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.