TITLE

AQUEOUS INKS CONTAINING SOLVENT DYES CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 from U.S. Provisional Ap- plication Serial No. 62/272176, filed December 29, 2015, which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present disclosure pertains to a dye-based inkjet ink and, more particularly, to a dye-based inkjet ink suitable for printing on textile. Digital printing methods such as inkjet printing are becoming increasingly important for the printing of textiles and offer a number of potential benefits over conventional printing methods such as screen printing. Digital printing eliminates the set up expense associated with screen preparation and can potentially enable cost-effective short run production. Inkjet printing furthermore allows visual effects, like infinite pattern re- peat sizes, that cannot be practically achieved with a screen-printing process.

One area of textile printing ideally suited to digital printing is the flag and banner market where short runs are common. However, printing of flags and banners presents unique challenges. For example, ink is printed on one side, but must penetrate the fabric so that the image is equally visible on the back (imprinted) side as on the front (printed) side. In addition, while the ink must travel through the fabric, it must not travel laterally causing blurring and bleeding. This seemingly contradictory set of conditions is not easily achieved. Furthermore, the printed products will typically be displayed in sunny areas and the colorants in the inks are preferably resistant to light fade.

US5847740 discloses an inkjet printing process on nylon cloth. US20050193499 discloses flag and banner printing methods and pretreatment solutions therefor.

Typically disperse dyes are used as colorants in digital inks for printing on polyester fabrics. Selection of specific Colour Index (CI) dyes have varied between ink manufacturers, but have generallybeen limited to the disperse class of CI dyes. A need exists for inkjet inks with wide gamut and desirable light-fastness for printing on textile. The present disclosure satisfies this need by providing aqueous inks containing solvent dyes in addition to disperse dyes.

SUMMARY OF THE INVENTION An embodiment provides an aqueous ink jet ink for printing on textile, said ink comprising an aqueous vehicle and a water-insoluble colorant dispersed by a polymeric dispersant, wherein said colorant comprises one or more solvent dyes having a structure of Formula I and one or more solvent dyes having a structure of Formula II:

® (II) wherein:

R ¹ and R ³ are independently CN or optionally substituted Ci-Cg alkoxycarbonyl;

R ² and R ⁴ are independently H or optionally substituted C1-C ₃ alkyl;

R ⁵ is CN, optionally substituted Ci-Cg alkylsulphonyl or optionally substituted Ci-Cg alkoxycar- bonyl;

R ⁶ is optionally substituted Ci-Cg alkyl, optionally substituted Ci-Cg alkoxycarbonyl, optionally ally substituted C3-C7 cycloalkyl or optionally substituted C6-C10 aryl;

R ⁷ is H or independently of R ⁶ and has the definition of R ⁶ ;

R ⁸ is optionally substituted Ci-Cg alkyl, optionally substituted Ci-Cg alkoxycarbonyl, optionally ally substituted C ₃ -C7 cycloalkyl or optionally substituted C ₆ -C1 ₀ aryl;

R ⁹ is H or independently of R ⁶ and has the definition of R ⁶ ;

R ¹⁰ is H, Ci-Cg alkyl or optionally substituted Ci-Cg alkyl; R ⁿ is CN or H;

R ¹² is H or Ci-Cg alkyl; and

X, Y, Z are independently H, NO2, CI, Br, F, C1-C5 alkyl, Ci-Cg alkylcarbonyl, optionally substituted C1-C2 ₀ alkoxycarbonyl, optionally substituted C6-C2 ₀ phenoxy sulfonate or optionally substi- tuted C6-C20 arylsulfonate.

Another embodiment provides that the ink further comprising a water miscible organic solvent.

Another embodiment provides that the polymeric dispersant is acrylic.

Another embodiment provides that the ink further comprising a shading component. Another embodiment provides that the ink further comprising a polymeric binder wherein said binder is different from said polymeric dispersant.

Another embodiment provides that the polymeric binder is polyurethane.

Another embodiment provides that the polymeric binder is acrylic.

These and other features and advantages of the present invention will be more readily un- derstood by those of ordinary skill in the art from a reading of the following detailed description. It is to be appreciated that certain features of the invention which are, for clarity, described above and below in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. In addition, references in the singular may also include the plural (for example, "a" and "an" may refer to one, or one or more) unless the context specifically states otherwise. Further, reference to values stated in ranges include each and every value within that range.

DETAILED DESCRIPTION

Unless otherwise stated or defined, all technical and scientific terms used herein have commonly understood meanings by one of ordinary skill in the art to which this invention pertains.

Unless stated otherwise, all percentages, parts, ratios, etc., are by weight.

When an amount, concentration, or other value or parameter is given as either a range, preferred range or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

As used herein, the term "aqueous vehicle" refers to water or a mixture of water and at least one water-soluble, or partially water-soluble (i.e. methyl ethyl ketone), organic solvent (co-solvent).

As used herein, the term "MW" means weight average molecular weight.

As used herein, the term "Mn" means number average molecular weight.

As used herein, the term "D50" means the volume particle diameter of the 50th percentile (median) of the distribution of particle sizes.

As used herein, the term 'D95 ' means the volume particle diameter of the 95th percentile of the distribution of particle sizes.

As used herein, the term "cPs" means centipoise, a viscosity unit.

As used herein, the term "mN.m ^"1 " means milliNewtons per meter, a surface tension unit. As used herein, the term "mPa.s" means millipascal second, a viscosity unit.

As used herein, the term "substituted alkyl" denotes substitution of hydrogen at- om(s) on an alkyl moiety by functional group(s) including ethers, esters, amines, thioether, mercaptans, hydroxy, halides, and acid groups, etc.

As used herein, the term "substituted arylsulfonate" denotes substitution of hydro- gen atom(s) on an arylsulfonate moiety by alkyl or functional group(s) including ethers, esters, amines, thioether, mercaptans, hydroxy, halides, and acid groups, etc. Another depiction of the arylsulfonate moiety is Ar-SC^O-, where Ar is an aryl group.

Unless otherwise noted, the above chemicals were obtained from Aldrich (Milwaukee, WI) or other similar suppliers of laboratory chemicals.

In addition, references in the singular may also include the plural (for example, "a" and

"an" may refer to one, or one or more) unless the context specifically states otherwise.

Colorants

The inks of the present ink set are characterized by the presence of particular, specified colorants. The colorants (dyes) are substantially solvent dyes. Solvent dyes are typi- cally used in solvent based, non-aqueous inks, or aqueous inks wherein the dye is dissolved in a solvent such as acetone or mixed with a dispersant followed by removal of the solvent by evaporation. The use of solvents is undesirable from several points of view including safety hazards and environmental effects. The inventors surprisingly found that certain solvent dyes can be dispersed by a polymeric dispersant and used in an aqueous media. In the present disclosure, the solvent dyes are used in an aqueous ink instead of a solvent based, non-aqueous ink.

Reference to the specified dyes is made by their "C.I." designation established by Society Dyers and Colourists, Bradford, Yorkshire, UK and published in The Color Index. Third Edition, 1971. Sources of these dyes are generally well known to those of ordinary skill in the relevant art.

The solvent dyes of the present disclosure include the ones having a structure of Formula I and Formula II:

(I) (II) wherein:

R ¹ and R ³ are independently CN or optionally substituted Ci-Cg alkoxycarbonyl;

R ² and R ⁴ are independently H or optionally substituted C1-C3 alkyl;

R ⁵ is CN, optionally substituted Ci-Cs alkylsulphonyl or optionally substituted Ci-Cs alkoxycarbonyl;

R ⁶ is optionally substituted Ci-Cg alkyl, optionally substituted Ci-Cg alkoxycarbonyl, optionally ally substituted C3-C7 cycloalkyl or optionally substituted C6-C1 ₀ aryl;

R ⁷ is H or independently of R ⁶ and has the definition of R ⁶ ; R is optionally substituted Ci-Cg alkyl, optionally substituted Ci-Cg alkoxycarbonyl, optionally ally substituted C3-C7 cycloalkyl or optionally substituted C6-C1 ₀ aryl;

R ⁹ is H or independently of R ⁶ and has the definition of R ⁶ ;

R ¹⁰ is H, Ci-Cg alkyl or optionally substituted Ci-Cg alkyl;

R ⁿ is CN or H;

R ¹² is H or Ci-Cg alkyl; and

X, Y, Z are independently H, NO2, CI, Br, F, C1-C5 alkyl, Ci-Cg alkylcarbonyl, optionally substituted C1-C2 ₀ alkoxycarbonyl, optionally substituted C6-C2 ₀ phenoxysulfonate or optionally substituted C6-C20 arylsulfonate.

Compounds of Formula (I) and Formula (II) include all geometric and stereoisomers, can exist as one or more stereoisomers. Stereoisomers are isomers of identical constitution but differing in the arrangement of their atoms in space and include enantiomers, diastereomers, cis-trans isomers (also known as geometric isomers), and tautomers. For a comprehensive discussion of all aspects of stereoisomerism, see Ernest L. Eliel and Samu- el H. Wilen, Stereochemistry of Organic Compounds, John Wiley & Sons, 1994.

Vehicle

The vehicle is a carrier for the colorant. An "aqueous vehicle" refers to a vehicle comprised of water or a mixture of water and at least one water-soluble organic solvent

(co-solvent). Selection of a suitable mixture depends on requirements of the specific ap- plication, such as desired surface tension and viscosity, the selected colorant, and compatibility with substrate onto which the ink will be printed.

Examples of water-soluble organic solvents include alcohols, ketones, keto- alcohols, ethers and others, such as thiodiglycol, sulfolane, 2-pyrrolidone, 1,3- dimethyl-2- imidazolidinone and caprolactam; glycols such as ethylene glycol, diethylene glycol, tri- ethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, trimethylene glycol, butylene glycol and hexylene glycol; addition polymers of ox- yethylene or oxypropylene such as polyethylene glycol, polypropylene glycol and the like;

triols such as glycerol and 1,2,6-hexanetriol; lower alkyl ethers of polyhydric alcohols, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl, diethylene glycol monoethyl ether; lower dialkyl ethers of polyhydric alcohols, such as diethylene glycol dimethyl or diethyl ether. An aqueous vehicle will typically contain about 30% to about 95% water with the balance (i.e., about 70% to about 5%) being the water-soluble solvent.

Additives

Other ingredients, additives, may be formulated into the inkjet ink, to the extent that such other ingredients do not interfere with the stability and jetablity of the finished ink, which may be readily determined by routine experimentation. Such other ingredients are in a general sense well known in the art.

Commonly, surfactants are added to the ink to adjust surface tension and wetting properties. Suitable surfactants include ethoxylated acetylene diols (e.g. Surfynols® series from Air Products), ethoxylated primary (e.g. Tomadol® series from Tomah Products) and secondary (e.g. Tergitol® series from Union Carbide) alcohols, sulfosuccinates (e.g. Aerosol® series from Cytec), organosilicones (e.g. Silwet® series from GE Silicons) and fluoro surfactants (e.g. Zonyl® series from DuPont). Surfactants are typically used in the amount of about 0.01 to about 5% and preferably about 0.2 to about 2%, based on the total weight of the ink.

Polymers may be added to the ink to improve durability. The polymers can be soluble in the vehicle or dispersed (e.g. "emulsion polymer" or "latex"), and can be ionic or nonionic. Useful classes of polymers include acrylics, styrene-acrylics and polyurethanes.

Biocides may be used to inhibit growth of microorganisms. Buffers may be used to maintain pH. Buffers include, for example, tris(hydroxymethyl)-aminomethane ("Trizma" or "Tris").

Inclusion of sequestering (or chelating) agents such as ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA), ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetic acid (NTA), dihydroxyethylglycine (DHEG), trans-1,2- cyclo- hexanediaminetetraacetic acid (CyDTA), dethylenetriamine-Ν,Ν,Ν',Ν", N"-pentaacetic acid (DTP A), and glycoletherdiamine-N,N,N',N'-tetraacetic acid (GEDTA), and salts thereof, may be advantageous, for example, to eliminate deleterious effects of heavy metal impurities. Proportions of Ingredients

The components described above can be combined to make an ink in various proportions and combinations in order to achieve desired ink properties, as generally described above, and as generally recognized by those of ordinary skill in the art. Some ex- perimentation may be necessary to optimize inks for a particular end use, but such optimization is generally within the ordinary skill in the art.

The amount of vehicle in an ink is typically in the range of from about 70 wt% to about 99.8 wt%, and more typically from about 80 wt% to about 99 wt%. Colorant is generally present in amounts up to about 15 wt%. For flag and banner applications, the color- ant is typically in the range of from about 3 wt% to about 12 wt%. Percentages are weight percent of the total weight of ink.

Other ingredients (additives), when present, generally comprise less than about 15 wt%, based on the total weight of the ink. Surfactants, when added, are generally in the range of from about 0.2 wt% to about 3 wt%, based on the total weight of the ink. Poly- mers can be added as needed, but will generally be less than about 15 wt%, based on the total weight of the ink.

Ink Properties

Drop velocity, separation length of the droplets, drop size and stream stability are greatly affected by the surface tension and the viscosity of the ink. Ink jet inks typically have a surface tension in the range of about 20 dyne/cm to about 70 dyne/cm at 25°C.

Viscosity can be as high as 30 cP at 25°C, but is typically somewhat lower. The ink has physical properties are adjusted to the ejecting conditions and printhead design. The inks should have excellent storage stability for long periods so as not clog to a significant extent in an ink jet apparatus. Further, the ink should not corrode parts of the ink jet printing device it comes in contact with, and it should be essentially odorless and non-toxic.

Substrate

The instant ink is suitable for printing on textile, and especially advantageous for printing substrate that is synthetic polyamide fabric, and particularly flag and banner stock. Most commonly, the synthetic polyamide fabric fibers are nylon-6 and/or nylon-6,6 fibers. For flag and banner stock, the fabric is generally from about 70 to about 200 deni- ers. A commercial example of such stock is SolarMax® 185 bright Nylon 200 denier, SGS-667/50, prepared for print; and SolarMax® 185 bright HT Nylon 70 denier, SGS- 773/76, prepared for print, both commercially available from Glen Raven Mills (Glen Raven, North Carolina). SolarMax® is a trademark of Invista.

Suitable printing substrate also includes paper. Typically, an image is printed on paper followed by transferring the printed image by heat or other means to a textile.

The fabric is commonly pretreated prior to printing. Application of the pretreatment to the fabric can be any convenient method and such methods are generally well- known in the art. One example is an application method referred to as padding. In padding, a fabric is dipped in the pretreatment solution, then the saturated fabric is passed through nip rollers that squeeze out the excess solution. The amount of solution retained in the fabric can be regulated by the nip pressure applied by the rollers. Other pretreatment techniques include spray application wherein the solution is applied by spraying on the face or face and back of the fabric. The wet pick-up of pretreatment solution is preferably from about 20 and about 100 grams of solution, and more preferably from about 25 to about 75 grams of solution, per 100 grams of fabric.

After application of pretreatment the fabric is dried in any convenient manner. The final percent moisture is (approximately) equal to the equilibrium moisture of the pretreated fabric at ambient temperature, and can vary somewhat depending on the relative humidity of the surrounding air.

The resins remaining in the fabric after drying provide the absorbent layer for the inkjet inks during printing. It will be appreciated that sufficient resin must be present to absorb the ink load applied. On the other hand, the presence of too much resin may prevent proper penetration. Routine optimization will reveal appropriate coating levels for a given printer and ink set. Other suitable pretreatments include those disclosed in U.S. Patent No. 6656228 and U.S. Patent Application Publication No. 20020081421, the disclosures of which are incorporated by reference herein for all purposes as if fully set forth.

Printing Method Printing can be accomplished by any inkjet printer equipped for handling and printing fabric. Commercial printers include, for example, the Dupont™ Artistri™ 3210 and 2020 printers, and the Mimaki TX series of printers.

The amount of ink laid down on the fabric can vary by printer model, by print mode (resolution) within a given printer and by the percent coverage need to achieve a given color. The combined effect of all these considerations is grams of ink per unit area of fabric for each color. In one embodiment, ink coverage is preferably from about 5 to about 17 grams of ink per square meter of fabric. There is a balance between the ink density needed to achieve a desired color and the absorption capacity of the coating resins in the pretreatment. Printed fabric will typically be post-treated according to procedures well-known in the textile art. A preferred post treatment is to heat the printed fabric with steam-treatment to set the printed inks, and washing the steam-treated fabric.

EXAMPLES

Six inks were prepared with colorants and loads listed in Table 1 below. Inks were prepared and jetted using a Seiko print rig. Various color wedges were printed on 250 denier woven polyester fabric which was fused with hot air at 400F (204 °C) for 2 minutes. DR 177 represents Direct Red 177, Rl represents Solvent Red 195, and Yl represents Direct Yellow 114. Table 1

The gamut properties of the above ink were measured and presented in Table 2 below. Data was measured using D65 illuminant with 2 degree observer.

Table 2

14.4 37.695 55.419 22.308 59.741 21.926 13.205 1.585

12.6 38.295 56.794 22.730 61.174 21.812 13.317 1.597

10.8 39.161 58.467 22.945 62.808 21.427 13.490 1.604

9.0 40.227 59.531 22.565 63.664 20.759 13.053 1.583

7.2 41.872 61.340 22.190 65.231 19.887 12.619 1.558

5.4 44.350 63.025 20.108 66.156 17.694 11.572 1.492

3.6 48.231 62.648 14.299 64.259 12.857 8.569 1.332

1.8 58.881 53.768 1.906 53.804 2.017 4.308 0.914

18.0 36.288 52.506 20.568 56.391 21.392 13.085 1.554

16.2 36.700 54.079 21.259 58.107 21.460 13.493 1.583

14.4 37.492 55.636 21.767 59.743 21.368 13.510 1.593

12.6 38.203 57.194 22.136 61.328 21.158 13.637 1.605

10.8 39.243 58.759 21.971 62.732 20.502 13.510 1.599

9.0 40.281 59.877 21.421 63.594 19.684 13.147 1.579

7.2 41.921 61.887 20.697 65.257 18.492 12.917 1.557

5.4 44.577 63.403 18.121 65.942 15.950 11.473 1.479

3.6 48.149 63.367 13.154 64.719 11.726 8.848 1.344

1.8 58.734 54.160 0.814 54.167 0.854 4.089 0.922

17.9 36.698 52.784 21.348 56.938 22.020 12.814 1.551

16.1 37.103 54.591 22.281 58.963 22.202 13.386 1.589

14.3 37.800 56.414 23.028 60.933 22.205 13.756 1.612

12.5 38.643 57.496 23.538 62.127 22.263 13.511 1.608

10.7 39.612 59.064 23.878 63.709 22.012 13.564 1.608

9.0 40.743 60.099 23.480 64.523 21.339 13.102 1.584

7.2 42.171 61.739 23.767 66.157 21.054 12.852 1.569 5.4 44.672 63.235 21.738 66.867 18.971 11.697 1.497

3.6 48.601 63.057 16.085 65.078 14.309 8.817 1.339

1.8 58.325 55.087 3.702 55.217 3.831 4.093 0.947

18.2 36.664 53.211 22.248 57.674 22.690 13.204 1.573

16.4 37.303 54.835 22.935 59.439 22.697 13.304 1.593

14.6 37.918 56.228 23.484 60.935 22.668 13.521 1.607

12.7 38.695 57.561 24.130 62.414 22.743 13.501 1.613

10.9 39.777 59.090 24.395 63.928 22.433 13.416 1.607

9.1 40.641 60.141 24.285 64.859 21.989 13.304 1.596

7.3 42.280 61.540 23.968 66.043 21.280 12.746 1.562

5.5 44.724 63.043 22.642 66.986 19.755 11.657 1.498

3.6 48.390 62.681 17.693 65.131 15.761 8.891 1.346

1.8 58.647 53.221 5.145 53.476 5.491 4.269 0.912

18.2 35.815 51.471 15.692 53.810 16.955 12.636 1.502

16.4 36.701 53.077 16.462 55.572 17.231 12.382 1.514

14.6 37.400 54.599 16.856 57.142 17.157 12.381 1.528

12.7 38.112 56.005 17.045 58.541 16.928 12.361 1.536

10.9 39.099 57.950 16.991 60.390 16.341 12.397 1.545

9.1 40.196 59.690 16.588 61.952 15.531 12.281 1.541

7.3 41.675 61.739 15.682 63.700 14.252 12.033 1.529

5.5 43.881 64.141 13.217 65.489 11.643 11.398 1.492

3.6 46.910 65.262 8.437 65.805 7.366 9.561 1.403

1.8 55.756 60.174 -2.571 60.234 357.546 4.280 1.080