WO2021211138A1

WO2021211138A1 - Fluid set

Info

Publication number: WO2021211138A1
Application number: PCT/US2020/028781
Authority: WO
Inventors: Zhang-Lin Zhou; Xiaoqi Zhou
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2021-10-21

Abstract

An example of an fluid set includes a pre-treatment fluid, a reactive fluid, and a white inkjet ink. The pre-treatment fluid includes a silicon-containing surface energy control agent and an aqueous pre-treatment vehicle. The reactive fluid includes a cross-linking agent and an aqueous reactive fluid vehicle. The white inkjet ink includes a white pigment particle; a self-cross-linked polyurethane binder particle; and an aqueous ink vehicle.

Description

FLUID SET BACKGROUND

[0001] Textile printing methods often include rotary and/or flat-screen printing. Traditional analog printing typically involves the creation of a plate or a screen, i.e., an actual physical image from which ink is transferred to the textile. Both rotary and flat screen printing have great volume throughput capacity, but also have limitations on the maximum image size that can be printed. For large images, pattern repeats are used. Conversely, digital inkjet printing enables greater flexibility in the printing process, where images of any desirable size can be printed immediately from an electronic image without pattern repeats. Inkjet printers are gaining acceptance for digital textile printing. Inkjet printing is a non-impact printing method that utilizes electronic signals to control and direct droplets or a stream of ink to be deposited on media.

BRIEF DESCRIPTION OF THE DRAWINGS [0002] Features of examples of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to similar, though perhaps not identical, components. For the sake of brevity, reference numerals or features having a previously described function may or may not be described in connection with other drawings in which they appear.

[0003] Fig. 1 schematically illustrates an example fluid set and an example textile printing kit, each of which includes an example of a fixer composition and an example of a white inkjet ink;

[0004] Fig. 2 is a flow diagram illustrating an example printing method;

[0005] Fig. 3 is a schematic diagram of an example of a printing system; and [0006] Fig. 4 depicts a T urn-On-Energy (TOE) curve for three example white inkjet inks, plotting drop weight in nanograms (ng) vs. energy in microJoules (pJ).

DETAILED DESCRIPTION

[0007] The textile market is a major industry, and printing on textiles, such as cotton, etc., has been evolving to include digital printing methods. Some digital printing methods enable direct to garment (or other textile) printing. White ink is one of the most heavily used inks in direct to textile printing. More than two-thirds of the textile printing that is performed utilizes a white ink on a colored textile.

There are certain challenges involved with thermally inkjet printing white ink formulations, and thus these inks may be printed using analog methods, such as screen printing, or other digital printing methods, such as piezoelectric inkjet printing. White ink formulations may be made with titanium dioxide or other white metal oxide pigments, which may have a high density (e.g., 4.23 g/cm³ for rutile and 3.78 g/cm³ for anatase titanium dioxide). These high density pigments can settle, which deleteriously affects the stability of the ink. These high density pigments can also limit the type and/or amount of polymeric binder that can be used in the ink, which can affect the thermal ink jettability of the ink. With textile printing, limited polymeric binder types and/or amounts can also affect the durability and/or opacity of the resulting image. Moreover, obtaining white images on textile fabrics with desirable opacity has also proven to be challenging because of fibrillation (e.g., hair-like fibers sticking out of the fabric surface).

[0008] Disclosed herein is a fluid set, which includes a white inkjet ink. The white inkjet ink includes a self-cross-linked polyurethane binder particle, which contributes to improved ink stability and thermal inkjet performance. The fluid set also includes a pre-treatment fluid and a reactive fluid. The pre-treatment fluid includes a silicon-containing surface energy control agent, which can increase the hydrophobicity of the textile fabric and reduce white ink penetration towards the bulk of the fabric. Reducing white ink penetration increases the amount of pigment at the textile fabric surface and thus increases image optical density. The reactive fluid includes a cross-linking agent that strongly fixes the binders and pigment in the white ink onto the fabric substrate. Together, the fluids in the fluid set generate white images and/or text on textile fabrics that have desirable opacity and durability (e.g., washfastness). The opacity and durability of the white prints is significantly improved when a dark textile fabric substrate is used. As such, the fluid set disclosed herein may be particularly suitable for generating opaque and durable white prints on dark, e.g., black, grey, etc. textile fabrics.

[0009] The compositions and/or white inkjet ink disclosed herein may include different components (e.g., polymeric binder, polymeric dispersant), and these polymeric binders and/or dispersant may have different acid numbers. As used herein, the term “acid number” refers to the mass of potassium hydroxide (KOH) in milligrams that is used to neutralize one (1 ) gram of a particular substance. The test for determining the acid number of a particular substance may vary, depending on the substance. For example, to determine the acid number of the self-cross- linked polyurethane binder, a known amount of a sample of the binder may be dispersed in water and the aqueous dispersion may be titrated with a polyelectrolyte titrant of a known concentration. In this example, a current detector for colloidal charge measurement may be used. An example of a current detector is the Miitek PCD-05 Smart Particle Charge Detector (available from BTG). The current detector measures colloidal substances in an aqueous sample by detecting the streaming potential as the sample is titrated with the polyelectrolyte titrant to the point of zero charge. An example of a suitable polyelectrolyte titrant is poly(diallyldimethylammonium chloride) (i.e., Poly DAD MAC). It is to be understood that any suitable test for a particular component may be used [0010] Throughout this disclosure, a weight percentage that is referred to as “wt% active” refers to the loading percentage of an active component, without taking into account the weight of an aqueous solvent (e.g., water), that may be present with the active component. As such, the wt% active refers to the dry weight. The term “wt%,” without the term actives, refers to the loading percentage (in the particular fluid) that accounts for all of the components in a fluid.

[0011] Pre-treatment Fluid

[0012] In the examples disclosed herein, the pre-treatment fluid includes a silicon-containing surface energy control agent and an aqueous pre-treatment vehicle. As illustrated in the Example section, the pre-treatment fluid disclosed herein contributes to generating prints that exhibit excellent durability. [0013] Silicon-Containing Surface Energy Control Agent [0014] The silicon-containing surface energy control agent is selected to help maintain the critical surface energy or surface tension (g) of the textile fabric within a desirable range before the reactive fluid and white inkjet ink are printed thereon.

In the examples disclosed herein, the critical surface tension is the surface tension at which a liquid (e.g., Dl water) completely wets the textile fabric. In an example, the silicon-containing surface energy control agent is selected to bring the critical surface tension of the textile fabric to within the range of from about 20 mN/m to about 55 mN/m at about 25°C. In another example, the silicon-containing surface energy control agent is selected to bring the critical surface tension of the textile fabric to within the range of from about 25 mN/m to about 45 mN/m at about 25°C. In still another example, the silicon-containing surface energy control agent is selected to bring the critical surface tension of the textile fabric to within the range of from about 30 mN/m to about 45 mN/m at about 25°C. In yet another example, the silicon-containing surface energy control agent is selected to bring the critical surface tension of the textile fabric to within the range of from about 40 mN/m to about 45 mN/m at about 25°C.

[0015] The silicon-containing surface energy control agent is selected from the group consisting of a polydialkylsiloxane, an organosilicone terpolymer, a silylated organic polymer, a disiloxane, a trisiloxane, a tetrasiloxane, and combinations thereof.

[0016] In some examples, the silicon-containing surface energy control agent is a polydialkylsiloxane. Specific examples of suitable polydialkylsiloxanes include polymethylhydrosiloxane, hydromethyl polysiloxane, dimethyl polysiloxane, hydromethyl-dimethyl polysiloxane, polyhexamethyl disiloxane, polydecamethyl tetrasiloxane, polydodecamethyl pentasiloxane, polyoctamethyl trisiloxane, polyoctamethyl cyclotetrasiloxane, polydodecamethyl cyclohexasiloxane, polydecamethyl cyclopentasiloxane, or a combination thereof. Other suitable polydialkylsiloxanes include copolymers with the following structure: where x is an integer from 1 to 500 and y is an integer from 1 to 20; each R is an alkyl group (e.g., a C1-C4 alkyl); each X is a methyl group or an end cap group, such as hydroxyl (-OH) or a C1-C4 alkoxy-substituted methyl and each X may be the same or different; and

is an organic functional group.

[0017] Examples of R^ in structure 1 include a mono amino group -R’NH₂, a

V diamino group -R’NHR”NH₂, an epoxy group , or an alicyclic epoxy group

in which R’ and R” are independently selected from hydrogen, an alkyl group (optionally substituted), or is/are absent. Other examples of R^ in structure 1 include hydrogen; hydroxyl, forming a silanol group; -R’OH, forming a carbinol group; -R’SH, forming a mercapto group; a carboxyl group, -R’COOH (e.g., a carboxylic acid); a phenol group

carboxylic anhydride group ; a fluoroalkyl group, -

CH₂CH₂CF₃; a long chain alkyl group -C_mH_2m+1 in which m is from 2 to 50; a fatty acid ester group, -OCOR’; or a fatty acid amide group -R’NHCOR”, in which R’ and R” are independently selected from hydrogen, an alkyl group (optionally substituted), or is/are absent. These organic functional groups can i) help control the hydrophobicity of the textile fabric surface, ii) improve the compatibility of the textile fabric with the aqueous vehicles of the reactive fluid and the white inkjet ink, iii) be reactive with other functional groups, such as -OH, present on the textile fabric surface, and/or iv) improve adhesion of the silicon-containing surface energy control agent with the textile fabric.

[0018] Still other examples of

in structure 1 include a polyether: R’(C₂H₄0)a(C₃H₆0)_bR’-, in which a and b are each in the range of 5 to 30 and may be the same or different, or an optionally substituted aralkyl group:

[0019] In other examples, the silicon-containing surface energy control agent is an organosilicone terpolymer. An organosilicone terpolymer may contain a number of reactive epoxy groups and oxyalkylene groups, in addition to siloxane or silanol groups.

[0020] In still other examples, the silicon-containing surface energy control agent is a silylated organic polymer. Silylated organic polymers may be obtained by reacting polymeric organic acids with silylated amino functional polyethers, hydrophilic organosilicones including a trialkoxysilyl pendant group, and a polyoxyethylene/polyoxypropylene chain terminated with hydrogen or an acyl group. [0021] In yet further examples, the silicon-containing surface energy control agent is a disiloxane. Examples of disiloxanes include hexamethyldisiloxane, dimethyltetramethoxydisiloxane, and trimethyltrimethoxydisiloxane.

[0022] In other examples, the silicon-containing surface energy control agent is a trisiloxane. An example of a trisiloxane is octamethyltrisiloxane.

[0023] In other examples, the silicon-containing surface energy control agent is a tetrasiloxane. An example of a tetrasiloxane is decamethyltetrasiloxane.

[0024] Another example of a suitable silicon-containing surface energy control agent is methyl hydrogen siloxane.

[0025] The silicon-containing surface energy control agent may be present in the pre-treatment fluid in an amount ranging from about 20 wt% active to about 100 wt% active. In other words, the silicon-containing surface energy control agent makes up from about 20 wt% to about 100 wt% of the solids in the pre-treatment fluid. In one example, silicon-containing surface energy control agent may be present in the pre-treatment fluid in an amount ranging from about 80 wt% active to about 95 wt% active. When the liquid components of the pre-treatment fluid are considered, the weight percentage of the silicon-containing surface energy control agent ranges from about 1 wt% to about 5 wt%.

[0026] The silicon-containing surface energy control agent may introduced into the pre-treatment fluid in the form on an emulsion. In these examples, the silicon- containing surface energy control agent is an oil that is dispersed in water using an emulsifier, such as anionic and non-ionic emulsifiers, polyethylene glycol based emulsifiers, and various commercially available emulsifiers for example, under the trade names of TERGITOL™, TRITON™, ECOSURF™, DOWSIL™, and CARBOWAX™ (each of which is available from Dow Chemical).

[0027] One example of a commercially available water-based silicone emulsion is WACKER® HC 303 from Wacker Chemie AG.

[0028] Aqueous Pre-treatment Vehicle

[0029] The aqueous pre-treatment vehicle includes water. The water may be purified water or deionized water. The amount of water will depend on the other components in the pre-treatment fluid. In some instances, the aqueous pre treatment vehicle includes water, without any other components. In other instances, the aqueous pre-treatment vehicle includes water and one or more additives. Some suitable additives may include a surfactant, a thickening agent, a defoamer, a pH control agent, or combinations thereof.

[0030] When included, the surfactant in the aqueous pre-treatment vehicle may be any non-ionic or cationic surfactant.

[0031 ] Examples of the non-ionic surfactant may include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, alkylalkanolamide, polyethylene glycol polypropylene glycol block copolymer, acetylene glycol, and a polyoxyethylene adduct of acetylene glycol. Specific examples of the non-ionic surfactant may include polyoxyethylenenonyl phenylether, polyoxyethyleneoctyl phenylether, and polyoxyethylenedodecyl. Further examples of the non-ionic surfactant may include silicon surfactants such as a polysiloxane oxyethylene adduct; fluorine surfactants such as perfluoroalkylcarboxylate, perfluoroalkyl sulfonate, and oxyethyleneperfluoro alkylether; and biosurfactants such as spiculisporic acid, rhamnolipid, and lysolecithin.

[0032] In some examples, the aqueous vehicle may include a silicone-free alkoxylated alcohol surfactant such as, for example, TEGO® Wet 510 (Evonik Degussa) and/or a self-emulsifiable wetting agent based on acetylenic diol chemistry, such as, for example, SURFYNOL® SE-F (Evonik Degussa). Other suitable commercially available surfactants include SURFYNOL® 465 (ethoxylatedacetylenic diol), SURFYNOL® 440 (an ethoxylated low-foam wetting agent) SURFYNOL® CT-211 (now CARBOWET® GA-211 , non-ionic, alkylphenylethoxylate and solvent free), and SURFYNOL® 104 (non-ionic wetting agent based on acetylenic diol chemistry), (all of which are from Evonik Degussa); ZONYL® FSO (a.k.a. CAPSTONE®, which is a water-soluble, ethoxylated non ionic fluorosurfactant from DuPont); TERGITOL® TMN-3 and TERGITOL® TMN-6 (both of which are branched secondary alcohol ethoxylate, non-ionic surfactants), and TERGITOL® 15-S-3, TERGITOL® 15-S-5, and TERGITOL® 15-S-7 (each of which is a secondary alcohol ethoxylate, non-ionic surfactant) (all of the TERGITOL® surfactants are available from The Dow Chemical Company); and BYK® 345, BYK® 346, BYK® 347, BYK® 348, BYK® 349 (each of which is a silicone surfactant) (all of which are available from BYK Chemie).

[0033] Examples of the cationic surfactant include quaternary ammonium salts, such as benzalkonium chloride, benzethonium chloride, methylbenzethonium chloride, cetalkonium chloride, cetylpyridinium chloride, cetrimonium, cetrimide, dofanium chloride, tetraethylammonium bromide, didecyldimethylammonium chloride, domiphen bromide, alkylbenzyldimethylammonium chlorides, distearyldimethylammonium chloride, diethyl ester dimethyl ammonium chloride, dipalmitoylethyl hydroxyethylmonium methosulfate, and ACCOSOFT® 808 (methyl (1) tallow amidoethyl (2) tallow imidazolinium methyl sulfate available from Stepan Company). Other examples of the cationic surfactant include amine oxides, such as lauryldimethylamine oxide, myristamine oxide, cocamine oxide, stearamine oxide, and cetamine oxide.

[0034] When included in the aqueous pre-treatment vehicle, the surfactant may be present in an amount ranging from about 0.01 wt% active to about 5 wt% active (based on the total dry wet weight of the pre-treatment fluid). In an example, the surfactant is present in an amount ranging from about 0.05 wt% active to about 3 wt% active, based on the total dry weight of the pre-treatment fluid. In another example, the surfactant is present in an amount of about 0.3 wt% active, based on the total dry weight of the pre-treatment fluid.

[0035] Examples of thickening agents that may be included in the pre-treatment fluid include for example, ASE (Alkali-Soluble Emulsion) type thickeners and HASE (Hydrophobically-modified Alkali-Soluble Emulsion) type thickeners. The high- molecular weight polymer-type thickeners and thickeners with large surface area substances, such as fumed silica, can be also used. The amount of the thickener that can be used in the pre-treatment fluid ranges from about 0.2 wt% active to about 3 wt% active. In other words, the thickener makes up from about 0.2 wt% to about 3 wt% of the solids in the pre-treatment fluid.

[0036] Examples of defoamers that may be included in the pre-treatment fluid include are, for example, aqueous coating deformers such as BYK® 12, BYK® 14 , BYK® 16, BYK® 22, BYK® 28, BYK® 38 and BYK® 39 (available from BYK USA Inc.) The amount of the defoamer that can be used in the pre-treatment fluid ranges from about 0.01 wt% active to about 0.5 wt% active. In other words, the defoamer makes up from about 0.01 wt% to about 0.5 wt% of the solids in the pre treatment fluid.

[0037] A pH control agent may also be included in the pre-treatment fluid. A pH adjuster may be included in the pre-treatment fluid to achieve a desired pH (e.g., about 4) and/or to counteract any slight pH increase that may occur over time. In an example, the total amount of pH control agent(s) in the pre-treatment fluid ranges from greater than 0 wt% to about 0.1 wt% (based on the total wet weight of the pre-treatment fluid). In another example, the total amount of pH adjuster(s) in the pre-treatment fluid is about 0.03 wt% (based on the total wet weight of the pre treatment fluid).

[0038] An example of a suitable pH control agent that may be used in the pre treatment fluid includes diluted hydrochloric acid (10%).

[0039] Suitable pH ranges for examples of the pre-treatment fluid can be less than pH 7, from pH 5 to less than pH 7, from pH 5.5 to less than pH 7, from pH 5 to pH 6.6, or from pH 5.5 to pH 6.6. In one example, the pH of the fixer composition is pH 5.5.

[0040] Cationic Polymer

[0041] Some examples of the pre-treatment fluid do not include a cationic polymer. In other examples however, the pre-treatment fluid may also include a cationic polymer. As will be described below, the reactive fluid includes a cross- linking agent, which may be a cationic polymer that can interact with the pigment and/or binder particles in the white inkjet ink to fix the components to the textile fabric. Any example of the cationic polymeric species described in reference to the reactive fluid may be used in some examples of the pre-treatment fluid. When included in the pre-treatment fluid, the cationic polymer is present in an amount ranging from about 0.1 wt% active to about 3 wt% active, based on the total wet weight of the pre-treatment fluid. In other examples, the cationic polymer is present in the pre-treatment fluid in an amount ranging from about 0.5 wt% active and 1 wt% active, based on the total wet weight of the pre-treatment fluid.

[0042] Reactive Fluid

[0043] In the examples disclosed herein, the reactive fluid includes a cross- linking agent and an aqueous reactive fluid vehicle. [0044] Cross-linking Agent

[0045] The cross-linking agent may be any polymeric component that includes reactive groups that can cross-link with reactive groups on the surface of the textile fabric (e.g., carboxyl groups, hydroxyl groups, amino groups, etc.) and/or in the white inkjet ink (e.g., carboxyl groups, amino groups, etc. on the self-cross-linked polyurethane binder molecules and on the surface of pigment dispersion particles). [0046] In the examples disclosed herein, the cross-linking agents are cationic polymers.

[0047] In some examples, the cationic polymer is a polyamine, i.e., an organic compound having more than two amino groups and that is capable of bearing ionizable amine moieties, such as primary, secondary, and tertiary amines. Some example amines include diethylenetriamine, 1 ,5-diaminopentane, 1 ,5- diaminopentane dihydrochloride, tris(2-aminoethyl)amine, 1 ,4,7-triazacyclononane, A/,/\/-Bis(3-aminopropyl)-1 ,4-butanediamine tetrahydrochloride, N,N'-B s(3- aminopropyl)ethylenediamine, A/,/\/-Bis(2-aminoethyl)-1 ,3-propanediamine, and . Some commercially available polyamines include ULTRAFLOC® 503, ULTRAFLOC® 507, ULTRAFLOC® 509, ULTRAFLOC® 512, and ULTRAFLOC® 518, all from GEO Specialty Chemicals Inc.

[0048] Other suitable cationic polymers include macromolecular compound (high molecular weight polymers or copolymers). As examples, the weight average molecular weight of the cationic polymer may range from about 3,000 to about 3,000,000. Any weight average molecular weight throughout this disclosure is in Daltons. Macromolecular compounds can perform a dual function in that they can i) fix ink pigments with their positive ionic charge and ii) bind with their high molecular weight.

[0049] Some example macromolecular compounds include an acrylamide monomer or co-monomer. These macromolecular compounds are initially characterized by a high molecular weight and are essentially non-ionic or anionic. The Mannich reaction is used to convert the acrylamide units into positively charged sites by decreasing the solution pH or by including the quaternization reaction in the manufacturing process. Examples of suitable macromolecular compounds are polyacrylamide; polyethyleneimine; polyethylenediamine acrylamide-acrylic acid copolymers; A/,/\/-dimethylaminoethyl methyl acrylate chloride quaternary; A/,/\/-dimethylaminoethyl methacrylate methyl chloride quaternary; poly(dimethylamine-co-epichlorohydrin); poly(monomethylamine-co- epichlorohydrin); a polyamine epichlorohydrin resin; a polyamide epichlorohydrin resin; poly(diallyldimethylammonium chloride); poly(methylene-co-guanidine) anion, wherein the anion is selected from the group consisting of hydrochloride, bromide, nitrate, sulfate, and sulfonates; or combinations thereof. Some examples of commercially available polydiallyldimethylammonium chloride may include ULTRAFLOC® 320HV, ULTRAFLOC® 320LV, ULTRAFLOC® 322HV and ULTRAFLOC® 322LV, each of which is available from GEO Specialty Chemicals. Some examples of commercially available polyamine epichlorohydrin resins may include CREPETROLTM 73, KYMENETM 736, KYMENETM 736NA, POLYCUPTM 7360, and POLYCUPTM 7360A, each of which is available from Solenis LLC. In one example of the reactive fluid, the cross-linking agent includes a cationic polymer selected from the group consisting of poly(dimethylamine-co- epichlorohydrin); a polyamide epichlorohydrin resin; a polyamine epichlorohydrin resin; and a combination thereof.

[0050] In an example, the cross-linking agent (e.g,. cationic polymer) of the reactive fluid is present in an amount ranging from about 1 wt% to about 15 wt% based on a total wet weight of the reactive fluid. In further examples, the cationic polymer is present in an amount ranging from about 1 wt% to about 10 wt%; or from about 4 wt% to about 8 wt%; or from about 2 wt% to about 7 wt%; or from about 2 wt% to about 6 wt%, based on a total wet weight of the reactive fluid.

[0051] Aqueous Reactive Fluid Vehicle

[0052] The aqueous reactive fluid vehicle includes water. The water may be purified water or deionized water. The amount of water will depend on the other components in the reactive fluid. In the examples disclosed herein, the reactive vehicle includes water, without any other components. In other instances, the aqueous reactive fluid vehicle includes water and one or more additives. Some suitable additives may include a co-solvent, a surfactant, or combinations thereof. [0053] The aqueous reactive fluid vehicle may include co-solvent(s). In an example, the co-solvent is a water soluble or water miscible organic co-solvent. Examples of co-solvents include alcohols, amides, esters, ketones, lactones, and ethers. In additional detail, the co-solvents may include aliphatic alcohols, aromatic alcohols, diols, glycol ethers, polyglycol ethers, lactams, formamides, acetamides, glycols, and long chain alcohols. Examples of such compounds include primary aliphatic alcohols, secondary aliphatic alcohols, 1 ,2-alcohols, 1 ,3-alcohols, 1 ,5- alcohols, ethylene glycol alkyl ethers, propylene glycol alkyl ethers (e.g., DOWANOL™ TPM or DOWANOL™ TPnB (from Dow Chemical), higher homologs (C₆-Ci₂) of polyethylene glycol alkyl ethers, N-alkyl caprolactams, unsubstituted caprolactams, both substituted and unsubstituted formamides, both substituted and unsubstituted acetamides, and the like. Specific examples of alcohols may include ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol. Other specific examples include dimethyl sulfoxide, sulfolane, propylene carbonate, ethylene carbonate, and/or alkyldiols, such as 1 ,2-hexanediol.

[0054] The co-solvent may also be a polyhydric alcohol or a polyhydric alcohol derivative. Examples of polyhydric alcohols may include ethylene glycol, diethylene glycol, propylene glycol, 2,2-dimethyl-1 ,3-propanediol, 2-ethyl-2-(hydroxymethyl)- 1 , 3-propanediol, butylene glycol, triethylene glycol, 1 ,5-pentanediol, 1 ,2-hexanediol, 1 ,2,6-hexanetriol, glycerin, trimethylolpropane, and xylitol. Examples of polyhydric alcohol derivatives may include an ethylene oxide adduct of diglycerin.

[0055] The co-solvent may also be a nitrogen-containing solvent. Examples of nitrogen-containing solvents may include 2-pyrrolidone, 1-(2-hydroxyethyl)-2- pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, and triethanolamine. [0056] The co-solvent(s) may be present in an amount ranging from about 4 wt% to about 30 wt% (based on the total wet weight of the reactive fluid). In an example, the total amount of co-solvent(s) present in the reactive fluid is about 10 wt% (based on the total wet weight of the reactive fluid).

[0057] The surfactant in the aqueous reactive fluid vehicle may be any example of the non-ionic and/or cationic surfactants set forth herein for the pre-treatment fluid. The amount of the non-ionic or cationic surfactant may be any amount set forth herein for the surfactant(s) in the pre-treatment fluid (except that the amount(s) are based on the total wet weight of the reactive fluid instead of the pre treatment fluid). [0058] White Inkjet Ink

[0059] In the examples disclosed herein, the white inkjet ink includes a white pigment particle, a self-cross-linked polyurethane binder particle, and an aqueous ink vehicle.

[0060] White Pigment Particles

[0061] Examples of suitable white pigment particles include white metal oxide pigments, such as titanium dioxide (Ti0₂), zinc oxide (ZnO), zirconium dioxide (Zr0₂), or the like. In one example, the white pigment is titanium dioxide. In an example, the titanium dioxide is in its rutile form. In another example, the titanium dioxide is in its anatase form.

[0062] In some examples, the white pigment may include white metal oxide pigment particles coated with silicon dioxide (Si0₂). In one example, the white metal oxide pigment content to silicon dioxide content can be from 100:3.5 to 5:1 by weight. In other examples, the white pigment may include white metal oxide pigment particles coated with silicon dioxide (Si0₂) and aluminum oxide (Al₂0₃). In one example, the white metal oxide pigment content to total silicon dioxide and aluminum oxide content can be from 50:3 to 4:1 by weight. One example of the white pigment includes TI-PURE® R960 (Ti02 pigment powder with 5.5 wt% silica and 3.3 wt% alumina (based on pigment content)) available from Chemours. Another example of the white pigment includes TI-PURE® R931 (Ti0₂ pigment powder with 10.2 wt% silica and 6.4 wt% alumina (based on pigment content)) available from Chemours.

[0063] The white pigment particles may have high light scattering capabilities, and the average particle size of the white pigment may be selected to enhance light scattering and lower transmittance, thus increasing opacity. The average particle size of the white pigment may range anywhere from about 100 nm to about 2000 nm. In another example, the average particle size of the white pigment may range anywhere from about 200 nm to about 500 nm. In some examples, the average particle size ranges from about 120 nm to about 2000 nm, from about 150 nm to about 1000 nm, from about 150 nm to about 750 nm, or from about 250 nm to about 350 nm, or from about 290 nm to about 300 nm. The term “average particle size”, as used herein, may refer to a volume-weighted mean diameter of a particle distribution. For example, the average particle size may be in terms of D50, which is the size that splits a distribution with half of the particle being above and half of the particles being below this diameter.

[0064] The amount of the white pigment in a dispersion that is used to form the white inkjet ink may range from about 20 wt% to about 60 wt%, based on the total weight of the dispersion.

[0065] The white pigment dispersion may then be incorporated into the ink vehicle so that the white pigment solids are present in an active amount that is suitable for the inkjet printing architecture that is to be used. In an example, the white pigment particles are present in an amount (which does not account for other dispersion components) ranging from about 3 wt% to about 20 wt%, based on a total wet weight of the white inkjet ink. In other examples, the white pigment is present in an amount ranging from about 5 wt% to about 20 wt%, or from about 5 wt% to about 15 wt%, based on a total wet weight of the white inkjet ink. In still another example, the white pigment is present in an amount of about 10 wt% based on a total wet weight of the white inkjet ink. These percentages reflect the total pigments solids in the final white inkjet ink.

[0066] The white pigment particles may be incorporated into the inkjet ink as a white pigment dispersion. The white pigment particles may be non-self-dispersed, and thus the dispersion may include a separate polymeric dispersant that disperses the pigment.

[0067] In an example, the separate pigment dispersant is selected from the group consisting of a water-soluble acrylic acid polymer, a branched co-polymer of a comb-type structure with polyether pendant chains and acidic anchor groups attached to a backbone, and a combination thereof.

[0068] Some examples of the water-soluble acrylic acid polymer include CARBOSPERSE® K7028 (polyacrylic acid having a weight average molecular weight (Mw) of about 2,300), CARBOSPERSE® K752 (polyacrylic acid having a weight average molecular weight (Mw) of about 2,000), CARBOSPERSE® K7058 (polyacrylic acid having a weight average molecular weight (Mw) of about 7,300), and CARBOSPERSE® K732 (polyacrylic acid having a weight average molecular weight (Mw) of about 6,000), all available from Lubrizol Corporation.

[0069] Some examples of the branched co-polymer of the comb-type structure with polyether pendant chains and acidic anchor groups attached to the backbone include DISPERBYK®-190 (an acid number of about 10 mg KOH/g) and DISPERBYK®-199, both available from BYK Additives and Instruments, as well as DISPERSOGEN® PCE available from Clariant.

[0070] The amount of the pigment dispersant in the dispersion may range from about 0.1 wt% to about 2 wt%, based on the total wet weight of the dispersion. [0071] The white pigment dispersion may then be incorporated into the ink vehicle so that the pigment dispersant is present in an amount ranging from about 0.01 wt% to about 0.5 wt%, based on a total wet weight of the white inkjet ink. In one of these examples, the dispersant is present in an amount of about 0.04 wt%, based on a total wet weight of the white inkjet ink. These percentages reflect the total dispersant solids in the final white inkjet ink.

[0072] In some examples, the pigment dispersant includes both the water- soluble acrylic acid polymer and the branched co-polymer of the comb-type structure with polyether pendant chains and acidic anchor groups attached to the backbone. In some of these examples, the pigment dispersant includes CARBOSPERSE® K7028 and DISPERBYK®-190. In some of these examples, the pigment dispersant includes both the water-soluble acrylic acid polymer and the branched co-polymer of the comb-type structure with polyether pendant chains and acidic anchor groups attached to the backbone, where the water-soluble acrylic acid polymer is present in an amount ranging from about 0.02 wt% to about 0.4 wt%, and the branched co-polymer of the comb-type structure with polyether pendant chains and acidic anchor groups attached to the backbone is present in an amount ranging from about 0.03 wt% to about 0.6 wt%. In one of these examples, the water-soluble acrylic acid polymer is present in an amount of about 0.09 wt%, and the branched co-polymer of the comb-type structure with polyether pendant chains and acidic anchor groups attached to the backbone is present in an amount of about 0.14 wt%.

[0073] The white pigment particles and the separate pigment dispersant (prior to being incorporated into the ink formulation), may be dispersed in water alone or in combination with an additional water soluble or water miscible co-solvent, such as 2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone, glycerol, 2-methyl-1 ,3-propanediol, 1 ,2-butane diol, diethylene glycol, triethylene glycol, tetraethylene glycol, or a combination thereof. It is to be understood that the liquid components of the white pigment dispersion become part of the aqueous ink vehicle in the white inkjet ink. [0074] Some commercially available white pigment dispersions include EMACOL™ SF white pigment dispersions (from Sanyo Color). Some of the EMACOL™ SF white pigment dispersions are pigment white 6 (Ti0₂) aqueous dispersions that have about 50% solids and a pH of 7.6.

[0075] Self-Cross-Linked Polyurethane Binder Particles

[0076] The binder particles in the white inkjet ink are made up of a self-cross- linked polyurethane.

[0077] The self-cross-linked polyurethane binder particles may be synthesized by first reacting a diisocyanate with a polyester diol. This reaction may occur in the presence of a catalyst (e.g., dibutyl tin dilaurate, bismuth octanoate, and 1 ,4- diazabicyclo[2.2.2]octane) and in an organic solvent (e.g., methyl ethyl ketone (MEK), tetrahydrofuran (THF), ethyl acetate, acetone, or combinations thereof) under reflux. This reaction forms a pre-polymer having urethane linkages. The pre-polymer is dissolved in the organic solvent.

[0078] Some example diisocyanates include hexamethylene-1 ,6-diisocyanate (HDI), 2,2,4-trimethyl-hexamethylene-diisocyanate (TDMI), 1 ,12-dodecane diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate, 2-methyl-1 ,5- pentamethylene diisocyanate, isophorone diisocyanate (IPDI), and combinations thereof. Polyester polyols are typically made from mixtures of diols, triols, and dibasic acids or anhydrides.

[0079] During this reaction, the diisocyanate is used in excess so that additional NCO groups are available for subsequent cross-linking.

[0080] The pre-polymer is then cross-linked. Cross-linking may be accomplished by adding water, and one or more diamine cross-linkers to the pre polymer solution.

[0081] With respect to the diamines that can be used in forming the polyurethane particles as described herein, polymerized sulfonated-diamines as well as non-ionic diamines can be used. Polymerized sulfonated-diamines can be prepared from diamines by adding sulfonate groups thereto. Non-ionic diamines can be diamines that include aliphatic groups that are not charged, such as alkyl groups, alicyclic groups, etc. A charged diamine is not used for the non-ionic diamine, if the non-ionic diamine is present. Example diamines can include various dihydrazides, alkyldihydrazides, sebacic dihydrazides, alkyldioic dihydrazides, aryl dihydrazides, e.g., terephthalic dihydrazide, organic acid dihydrazide, e.g., succinic dihydrazides, adipic acid dihydrazides, etc, oxalyl dihydrazides, azelaic dihydrazides, carbohydrazide, etc. It is noted however that these examples may not be appropriate for use as one or the other type of diamine, but rather, this list is provided as being inclusive of the types of diamines that can be used in forming the polymerized sulfonated-diamines and/or the non-ionic diamines, and not both in every instance (though some can be used for either type of diamine).

[0082] Example diamine structures are shown below. More specific examples of diamines include 4,4'-methylenebis(2-methylcyclohexyl-amine) (DMDC), 4- methyl-1 ,3'-cyclohexanediamine (HTDA), 4,4'-Methylenebis(cyclohexylamine) (PACM), isphorone diamine (I PDA), tetramethylethylenediamine (TMDA), ethylene diamine (DEA), 1 ,4-cyclohexane diamine, 1 ,6-hexane diamine, hydrazine, adipic acid dihydrazide (AAD), carbohydrazide (CHD), and/or diethylene triamine (DETA), notably, DETA includes three amines, and thus, is a triamine. However, since it also includes 2 amines, it is considered to fall within the definition herein of “diamine,” meaning it includes two amines. Many of the diamine structures shown below can be used as the non-ionic diamine, such as the uncharged aliphatic diamines shown below. H₂

IPDA TMDA DEA 1,4-cyclohexane diamine 1,6-hexane diamine hydrazine

AAD CHD DETA

[0083] There are also other alkyl diamines (other than 1 ,6-hexane diamine) that can be used, such as, by way of example:

[0084] There are also other dihydrazides (other than AAD shown above) that can be used, such as, by way of example:

[0085] As an example of a carboxylate-or sulfonated diamine, which in this case is an alkylamine-alkylamine-sulfonate (shown as a sulfonic acid in Formula I below, but as a sulfonate, would include a positive counterion associated with an S0₃ group). While one example is shown in Formula I below, it is to be understood that other diamines may be used, including those based on structures shown above.

(Formula I)

[0086] where R is H or is a C1 to C10 straight-or branched-alkyl or alicyclic or combination of alkyl and alicyclic, m is 1 to 5, and n is 1 to 5. One example of such a structure, sold by Evonik Industries (USA), is A-95, which is exemplified where R is H, m is 1 , and n is 1. Another example structure sold by Evonik Industries is VESTAMIN®, where R is H, m is 1 , and n is 2.

[0087] After the cross-linking reaction, any solvent is then removed, e.g., by vacuum distillation to afford the final polyurethane dispersion (i.e. , self-cross-linked polyurethane binder particles dispersed in water). More specifically, the polyurethane solution may be slowly added to water including a base with vigorous agitation, or vice versa. The mixture may be stirred and the organic solvent may be removed by distillation to form the polyurethane binder dispersion. In an example, the acid number of the self-cross-linked polyurethane binder particles is 30 mg KOH/g solid resin or less, or 10 mg KOH/g solid resin or less. As examples, the self-cross-linked polyurethane binder particles may have an acid number ranging from greater than 0 mg KOH/g to 30 mg KOH/g, or from greater than 0 mg KOH/g to about 20 mg KOH/g, or from greater than 0 mg KOH/g to about 19 mg KOH/g, or from greater than 0 mg KOH/g to about 15 mg KOH/g, or from greater than 0 mg KOH/g to about 10 mg KOH/g, etc.

[0088] The average particle size of the self-cross-linked polyurethane binder particles may range from about 200 nm to about 400 nm. In one example, this range refers to the D50 particle size. As examples, the self-cross-linked polyurethane binder particles may have a D50 particle size ranging from about 200 nm to about 400 nm, or from about 200 nm to about 350 nm, or from about 300 nm to about 375 nm, or from about 250 nm to about 350 nm, etc.

[0089] In some examples, the self-cross-linked polyurethane binder particles also have an acid number less than 10, a weight average molecular weight ranging greater than 50,000, and a particle size ranging from about 200 nm to about 400 nm.

[0090] The self-cross-linked polyurethane binder particles may be incorporated into the inkjet ink as a polyurethane dispersion, and any liquid components of the dispersion become part of the ink vehicle. The polyurethane dispersion is added in a suitable amount so that the solid self-cross-linked polyurethane binder particles are present in an active amount that is suitable for the inkjet printing architecture that is to be used. In an example, the self-cross-linked polyurethane binder particles (which does not account for other dispersion components) are present in an amount ranging from about 1 wt% to about 30 wt%, based on a total wet weight of the white inkjet ink. In other examples, the self-cross-linked polyurethane binder particles are present in an amount ranging from about 2 wt% to about 20 wt%, or from about 3 wt% to about 15 wt%, based on a total wet weight of the white inkjet ink. In still another example, the self-cross-linked polyurethane binder particles are present in an amount of about 5 wt% or about 12 wt%, based on a total wet weight of the white inkjet ink. These percentages reflect the total self-cross-linked polyurethane binder solids in the final white inkjet ink.

[0091] Aqueous Ink Vehicle

[0092] The aqueous ink vehicle includes water. The water may be purified water or deionized water. The amount of water will depend on the other components in the white inkjet ink, but will include at least 30 wt%. In some instances, water may be present in the white inkjet ink in an amount of at least 60 wt%. Water may be present in an amount of at most 99 wt%, for example, at most 95 wt%. In some examples, water may be present in the white inkjet ink in an amount ranging from about 30 wt% to about 99 wt%, for instance, from about 40 wt% to about 98 wt% or from about 50 wt% to about 95 wt%. In other examples, water may be present in an amount ranging from about 60 wt% to about 93 wt%, for instance, from about 70 wt% to about 90 wt%.

[0093] In the examples disclosed herein, the aqueous ink vehicle includes water, without any other components. In other instances, the aqueous ink vehicle includes water and one or more additives. Some suitable additives may include a co-solvent, a surfactant, a humectant, an anti-microbial agent, a chelating agent, an anti-kogation agent, a viscosity modifier, a pH control agent, combinations thereof. [0094] Any of the co-solvents set forth herein for the reactive fluid may be used in the white inkjet ink. The amount of the co-solvent in the white inkjet ink may be up to 50 wt%, depending on the jetting architecture. As other example, the co- solvents) may range from about 1 wt% to about 30 wt%, or from about 5 wt% to about 20 wt% of the total wet weight of the white inkjet ink.

[0095] The surfactant in the aqueous ink vehicle may be any example of the non-ionic surfactant set forth herein for the reactive fluid. The surfactant in the aqueous ink vehicle may also or alternatively be an anionic surfactant. Examples of the anionic surfactant may include alkylbenzene sulfonate, alkylphenyl sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, sulfate ester salt of higher fatty acid ester, sulfonate of higher fatty acid ester, sulfate ester salt and sulfonate of higher alcohol ether, higher alkyl sulfosuccinate, polyoxyethylene alkylether carboxylate, polyoxyethylene alkylether sulfate, alkyl phosphate, and polyoxyethylene alkyl ether phosphate. Specific examples of the anionic surfactant may include dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenyl sulfonate, monobutylbiphenylsul fonate, and dibutylphenylphenol disulfonate.

[0096] The amount of the non-ionic and/or anion surfactant present in the white inkjet ink may be any amount set forth herein for the surfactant(s) in the pre treatment fluid (except that the amount(s) are based on the total weight of the white inkjet ink instead of the pre-treatment fluid).

[0097] The aqueous ink vehicle may include a humectant. An example of a suitable humectant is ethoxylated glycerin having the following formula:

in which the total of a+b+c ranges from about 5 to about 60, or in other examples, from about 20 to about 30. An example of the ethoxylated glycerin is LIPONIC® EG-1 (LEG-1 , glycereth-26, a+b+c=26, available from Lipo Chemicals). Other examples of suitable humectants include alcohols, for example, glycols such as 2,2’-thiodiethanol, glycerol, 1 ,3-propanediol, 1 ,5-pentanediol, polyethylene glycol, ethylene glycol, diethylene glycol, propylene glycol and/or tetraethylene glycol; pyrrolidones, such as 2-pyrrolidone, N-methyl-2-pyrrolidone, and/or N-methyl-2- oxazolidinone; and/or monoalcohols, such as n-propanol and/or iso-propanol. In an example, the humectant includes a mixture of alcohols. In another example, the humectant includes a mixture of 2,2'-thiodiethanol and a glycol, such as a polyalkylene glycol.

[0098] The humectant(s) may be present in an amount ranging from about 0.2 wt% to about 5 wt% (based on the total wet weight of the white inkjet ink). In an example, the humectant is present in the white inkjet ink in an amount of about 1 wt%, based on the total wet weight of the white inkjet ink.

[0099] The aqueous ink vehicle may also include anti-microbial agent(s). Anti microbial agents are also known as biocides and/or fungicides. Examples of suitable anti-microbial agents include the NUOSEPT® (Ashland Inc.),

UCARCIDE™ or KORDEK™ or ROCIMA™ (The Dow Chemical Company), PROXEL® (Arch Chemicals) series, ACTICIDE® B20 and ACTICIDE® M20 and ACTICIDE® MBL (blends of 2-methyl-4-isothiazolin-3-one (MIT), 1 ,2- benzisothiazolin-3-one (BIT) and Bronopol) (Thor Chemicals), AXIDE™ (Planet Chemical), NIPACIDE™ (Clariant), blends of 5-chloro-2-methyl-4-isothiazolin-3-one (CIT or CMIT) and MIT under the tradename KATHON™ (The Dow Chemical Company), and combinations thereof.

[0100] In an example, the total amount of anti-microbial agent(s) in the white inkjet ink ranges from about 0.001 wt% to about 0.05 wt% (based on the total wet weight of the white inkjet ink). In another example, the total amount of anti microbial agent(s) in the white inkjet ink is about 0.04 wt% (based on the total wet weight of the inkjet ink).

[0101] The aqueous ink vehicle may also include chelating agent/sequestering agent. In an example, the chelating agent is selected from the group consisting of methylglycinediacetic acid, trisodium salt; 4,5-dihydroxy-1 ,3-benzenedisulfonic acid disodium salt monohydrate; ethylenediaminetetraacetic acid (EDTA); hexamethylenediamine tetra(methylene phosphonic acid), potassium salt; and combinations thereof. Methylglycinediacetic acid, trisodium salt (Na3MGDA) is commercially available as TRILON® M from BASF Corp. 4,5-dihydroxy-1 ,3- benzenedisulfonic acid disodium salt monohydrate is commercially available as TIRON™ monohydrate. Hexamethylenediamine tetra(methylene phosphonic acid), potassium salt is commercially available as DEQUEST® 2054 from Italmatch Chemicals.

[0102] When included in the white inkjet ink, the chelating agent is present in an amount greater than 0 wt% and less than or equal to 0.5 wt% based on the total wet weight of the white inkjet ink. In an example, the chelating agent is present in an amount ranging from about 0.05 wt% to about 0.2 wt% based on the total wet weight of the white inkjet ink.

[0103] An anti-kogation agent may also be included in the vehicle of the white inkjet ink, for example, when the white inkjet ink is to be applied via a thermal inkjet printhead. Anti-kogation agent(s) is/are included to assist in preventing the buildup of kogation. In some examples, the anti-kogation agent may improve the jettability of the white inkjet ink.

[0104] Examples of suitable anti-kogation agents include oleth-3-phosphate (commercially available as CRODAFOS™ 03A or CRODAFOS™ N-3A) or dextran 500k. Other suitable examples of the anti-kogation agents include CRODAFOS™ HCE (phosphate-ester from Croda Int.), CRODAFOS® 010A (oleth-10-phosphate from Croda Int.), or DISPERSOGEN® LFH (polymeric dispersing agent with aromatic anchoring groups, acid form, anionic, from Clariant), etc. It is to be understood that any combination of the anti-kogation agents listed may be used. [0105] The anti-kogation agent may be present in the white inkjet ink in an amount ranging from about 0.1 wt% to about 1 .5 wt%, based on the total wet weight of the white inkjet ink. In an example, the anti-kogation agent is present in an amount of about 0.5 wt%, based on the total wet weight of the white inkjet ink. [0106] The aqueous ink vehicle may also include a pH control agent. A pH adjuster may be included in the white inkjet ink to achieve a desired pH (e.g., 8.5) and/or to counteract any slight pH drop that may occur over time. In an example, the total amount of pH adjuster(s) in the white inkjet ink ranges from greater than 0 wt% to about 0.1 wt% (based on the total wet weight of the white inkjet ink). In another example, the total amount of pH adjuster(s) in the white inkjet ink is about 0.03 wt% (based on the total wet weight of the white inkjet ink). [0107] Examples of suitable pH adjusters include metal hydroxide bases, such as potassium hydroxide (KOH), sodium hydroxide (NaOH), etc. In an example, the metal hydroxide base may be added to the white inkjet ink in an aqueous solution.

In another example, the metal hydroxide base may be added to the white inkjet ink in an aqueous solution including 5 wt% of the metal hydroxide base (e.g., a 5 wt% potassium hydroxide aqueous solution).

[0108] Suitable pH ranges for examples of the white inkjet ink can be from pH 7 to pH 11 , from pH 7 to pH 10, from pH 7.2 to pH 10, from pH 7.5 to pH 10, from pH 8 to pH 10, 7 to pH 9, from pH 7.2 to pH 9, from pH 7.5 to pH 9, from pH 8 to pH 9, from 7 to pH 8.5, from pH 7.2 to pH 8.5, from pH 7.5 to pH 8.5, from pH 8 to pH 8.5, from 7 to pH 8, from pH 7.2 to pH 8, or from pH 7.5 to pH 8.

[0109] Fluid Sets and Printing Kits

[0110] The pre-treatment fluid, the reactive fluid, and the white inkjet ink may be part of a fluid set. An example of the fluid set 10 disclosed herein is shown schematically in Fig. 1. In an example, the fluid set 10 includes the pre-treatment fluid 12 including a silicon-containing surface energy control agent and an aqueous pre-treatment vehicle; a reactive fluid 14 including a cross-linking agent and an aqueous reactive fluid vehicle; and a white inkjet ink 16, including a white pigment particle, a self-cross-linked polyurethane binder particle, and an aqueous ink vehicle. It is to be understood that any example of the pre-treatment fluid 12, the reactive fluid 14, and the white inkjet ink 16 disclosed herein may be used in the examples of the fluid set 10.

[0111] In any example of the fluid set 10, the reactive fluid 14 and the white inkjet ink 16 may be maintained in separate containers (e.g., respective reservoirs/fluid supplies of respective inkjet cartridges) or separate compartments (e.g., respective reservoirs/fluid supplies) in a single container (e.g., inkjet cartridge).

[0112] The fluid set 10 may also be part of a textile printing kit 20 which is also shown schematically in Fig. 1. Thus, the textile printing kit 20 includes a textile fabric 18; a pre-treatment fluid 12 including a silicon-containing surface energy control agent and an aqueous pre-treatment vehicle; a reactive fluid 14 including a cross-linking agent and an aqueous reactive fluid vehicle; and a white inkjet ink 16 including a white pigment particle, a self-cross-linked polyurethane binder particle, and an aqueous ink vehicle. In an example of the textile printing kit 20, the textile fabric 18 is selected from the group consisting of polyester fabrics, polyester blend fabrics, cotton fabrics, cotton blend fabrics, nylon fabrics, nylon blend fabrics, silk fabrics, silk blend fabrics, wool fabrics, wool blend fabrics, and combinations thereof.

[0113] Textile Fabrics

[0114] In the examples disclosed herein, the textile fabric 18 may be selected from the group consisting of polyester fabrics, polyester blend fabrics, cotton fabrics, cotton blend fabrics, nylon fabrics, nylon blend fabrics, silk fabrics, silk blend fabrics, wool fabrics, wool blend fabrics, and combinations thereof. In a further example, the textile fabric 18 is selected from the group consisting of cotton fabrics and cotton blend fabrics.

[0115] It is to be understood that organic textile fabrics and/or inorganic textile fabrics may be used for the textile fabric 18. Some types of fabrics that can be used include various fabrics of natural and/or synthetic fibers. It is to be understood that the polyester fabrics may be a polyester coated surface. The polyester blend fabrics may be blends of polyester and other materials (e.g., cotton, linen, etc.). In another example, the textile fabric 18 may be selected from nylons (polyamides) or other synthetic fabrics.

[0116] Example natural fiber fabrics that can be used include treated or untreated natural fabric textile substrates, e.g., wool, cotton (regular plant cotton, organic cotton, pima cotton, supima cotton, and/or slub cotton), silk, linen, jute, flax, hemp, rayon fibers, thermoplastic aliphatic polymeric fibers derived from renewable resources (e.g. cornstarch, tapioca products, sugarcanes), etc. Example synthetic fibers used in the textile fabric/substrate 18 can include polymeric fibers such as nylon fibers, polyvinyl chloride (PVC) fibers, PVC-free fibers made of polyester, polyamide, polyimide, polyacrylic, polypropylene, polyethylene, polyurethane (LYCRA®, The Lycra Co.), polystyrene, polyaramid (e.g., KEVLAR®) polytetrafluoroethylene (TEFLON®) (both trademarks of E.l. du Pont de Nemours and Company, Delaware), fiberglass, polytrimethylene, polycarbonate, polyethylene terephthalate, polyester terephthalate, polybutylene terephthalate, or a combination thereof. In an example, natural and synthetic fibers may be combined at ratios of 1 :1 , 1 :2, 1 :3, 1 :4, 1 :5, 1 :6, 1 :7, 1 :8, 1 :9, 1 :10, 1 :11 , 1 :12, 1 :13, 1 :14, 1 :15, 1 :16, 1 :17, 1 :18, 1 :19, 1 :20, or vice versa. One example blend includes polyester, cotton, and rayon.

[0117] In some examples, the fiber can be a modified fiber from the above-listed polymers. The term “modified fiber” refers to one or both of the polymeric fiber and the fabric as a whole having undergone a chemical or physical process such as, but not limited to, copolymerization with monomers of other polymers, a chemical grafting reaction to contact a chemical functional group with one or both the polymeric fiber and a surface of the fabric, a plasma treatment, a solvent treatment, acid etching, or a biological treatment, an enzyme treatment, or anti-microbial treatment to prevent biological degradation.

[0118] In addition, the textile fabric 18 can contain additives, such as a colorant (e.g., pigments, dyes, and tints), an antistatic agent, a brightening agent, a nucleating agent, an antioxidant, a UV stabilizer, a filler, and/or a lubricant, for example.

[0119] It is to be understood that the terms “textile fabric” or “fabric substrate” are used interchangeably, and do not include materials commonly known as any kind of paper (even though paper can include multiple types of natural and synthetic fibers or mixtures of both types of fibers). Fabric substrates can include textiles in filament form, textiles in the form of fabric material, or textiles in the form of fabric that has been crafted into finished articles (e.g., clothing, blankets, tablecloths, napkins, towels, bedding material, curtains, carpet, handbags, shoes, banners, signs, flags, etc.). In some examples, the fabric substrate can have a woven, knitted, non-woven, or tufted fabric structure. In one example, the fabric substrate can be a woven fabric where warp yarns and weft yarns can be mutually positioned at an angle of about 90°. This woven fabric can include fabric with a plain weave structure, fabric with an end-on-end weave, fabric with a voile weave, fabric with an Oxford weave, fabric with twill weave structure where the twill weave produces diagonal lines on a face of the fabric, or a satin weave. In another example, the fabric substrate can be a knitted fabric with a loop structure. The loop structure can be a warp-knit fabric, a weft-knit fabric, or a combination thereof. A warp-knit fabric refers to every loop in a fabric structure that can be formed from a separate yarn mainly introduced in a longitudinal fabric direction. A weft-knit fabric refers to loops of one row of fabric that can be formed from the same yarn. In a further example, the fabric substrate can be a non-woven fabric. For example, the non-woven fabric can be a flexible fabric that can include a plurality of fibers or filaments that are one or both bonded together and interlocked together by a chemical treatment process (e.g., a solvent treatment), a mechanical treatment process (e.g., embossing), a thermal treatment process, or a combination of multiple processes.

[0120] In one example, the textile fabric 18 can have a basis weight ranging from 10 gsm to 500 gsm. In another example, the textile fabric 18 can have a basis weight ranging from 50 gsm to 400 gsm. In other examples, the textile fabric 18 can have a basis weight ranging from 100 gsm to 300 gsm, from 75 gsm to 250 gsm, from 125 gsm to 300 gsm, or from 150 gsm to 350 gsm.

[0121] The textile fabric 18 may be any color, and in an example is a color other than white.

[0122] Printing Method and System

[0123] Fig. 2 depicts an example of a printing method 100. As shown in Fig. 2, an example of the printing method 100 comprises applying a pre-treatment fluid 12 to a textile fabric 18 to form a treated textile fabric, the pre-treatment fluid 12 including a silicon-containing surface energy control agent and an aqueous pre treatment vehicle (reference numeral 102); drying the treated textile fabric (reference numeral 104); and sequentially printing a reactive fluid 14 and a white inkjet ink 16 on the dried, treated textile fabric, the reactive fluid 14 including: a cross-linking agent; and an aqueous reactive fluid vehicle; and the white inkjet ink 16 including: a white pigment particle; a self-cross-linked polyurethane binder particle; and an aqueous ink vehicle (reference numeral 106).

[0124] Another example of the printing method 100 comprises applying a pre treatment fluid 12 to a textile fabric 18 to form a treated textile fabric, the pre treatment fluid 12 including a silicon-containing surface energy control agent and an aqueous pre-treatment vehicle (reference numeral 102); and sequentially printing a reactive fluid 14 and a white inkjet ink 16 on the treated textile fabric, the reactive fluid 14 including: a cross-linking agent; and an aqueous reactive fluid vehicle 14; and the white inkjet ink 16 including: a white pigment particle; a self- cross-linked polyurethane binder particle; and an aqueous ink vehicle (reference numeral 106). In this example, the treated textile fabric is not dried before receiving the aqueous reactive fluid 14 or the white inkjet ink 16.

[0125] It is to be understood that any example of the pre-treatment fluid 12, the reactive fluid 14, and the white inkjet ink 14 may be used in the examples of the method 100. Further, it is to be understood that any example of the textile fabric 18 may be used in the examples of the method 100.

[0126] As shown in reference numeral 102 in Fig. 2, the method 100 includes applying the pre-treatment fluid 12 to the textile fabric 18. The pre-treatment fluid may be applied using any suitable analog method. Using analog methods, the pre treatment fluid 12 may be applied using an auto analog pretreater, a drawdown coater, a slot die coater, a roller coater, a fountain curtain coater, a blade coater, a rod coater, an air knife coater, a sprayer, or a gravure application.

[0127] In one example, the textile fabric 18 is passed under an adjustable spray nozzle. The adjustable spray nozzle may alter the rate at which the pre-treatment fluid 12 is sprayed onto the textile fabric 18. By adjusting factors, such as the rate at which the textile fabric 18 is passed under the nozzle, the rate at which the pre treatment fluid 12 is sprayed on textile fabric 18, the distance of the textile fabric 18 from the nozzle, the spraying profile of the nozzle, and the concentration of the surface energy control agent in the pre-treatment fluid 12 (such as, in one example, from 0.1% to 30% dry (active) weight percentage, or from 1% to 10% dry (active) weight percentage of pre-treatment fluid 12), a layer of pre-treatment fluid 12 with desired attributes may be deposited on the textile fabric 18. In other examples, the pre-treatment fluid may be spontaneously distributed on the surface of textile fabric 18.

[0128] With any of the analog methods, the pre-treatment fluid 12 may be coated on all or substantially all of the textile fabric 18. As such, the pre-treatment fluid layer that is formed may be a continuous layer that covers all or substantially all of the textile fabric 18. In an example, the pre-treatment fluid 12 is applied in an amount ranging from about 20 gsm to about 250 gsm. In another example, the pre treatment fluid 12 is applied in an amount ranging from about 50 gsm to about 75 gsm. [0129] After applying pre-treatment fluid 12, the textile fabric 18 can be forwarded to the printing zone B without drying (i.e. , wet-on-wet printing), or alternatively, the pre-treated textile fabric 18 with 12 thereon can be dried and then forwarded to the printing zone B (i.e., dry-on-wet printing).

[0130] As shown in reference numeral 104 in Fig. 2, one example of the method 100 includes drying the treated textile fabric (i.e., the fabric 18 with the pre treatment fluid 12 thereon). Drying may be accomplished using any suitable dryer or an oven. In one example, a box hot air dryer is used. The dryer can be a single unit or could include a series of 3 to 7 units so that a temperature profile can be created with initial exposure being to a higher temperature (to remove excessive water) followed by exposure to mild temperatures (to ensure substantially complete drying with a final moisture level of less than 5%, 4%, 3%, 2%, or 1%, for example). The peak dryer temperature can be programmed into a profile with higher temperature at the beginning of the drying when wet moisture is high and reduced to a lower temperature when the treated textile fabric is becoming dry. The dryer temperature is controlled to a temperature of less than about 100°C. In some examples, the operation speed of the drying line is about 50 yards per minute. [0131] As shown in reference numeral 106 in Fig. 2, the method 100 includes sequentially printing the reactive fluid 14 and the white inkjet ink 16 on the dried, treated textile fabric. Several passes may be performed so that several layers of the reactive fluid 14 and white inkjet ink 16 are printed.

[0132] The fluid 14 and ink 16 are wet when the next layer fluid or 16 is applied. Wet on wet printing may be desirable because less reactive fluid 14 may be applied during this process (as compared to when the reactive fluid 14 is dried prior to inkjet ink 16 application), and because the printing workflow may be simplified without the additional drying. In an example of wet on wet printing, the white inkjet ink 16 is printed onto the reactive fluid 14 or the reactive fluid 14 is printed onto the white inkjet ink 16 within a period of time ranging from about 0.01 second to about 30 seconds after the fixer composition 12 is printed. In further examples, the white inkjet ink 16 is printed onto the reactive fluid 14 or the reactive fluid is printed onto the white inkjet ink 16 within a period of time ranging from about 0.1 second to about 20 seconds; or from about 0.2 second to about 10 seconds; or from about 0.2 second to about 5 seconds after the previous layer is applied. [0133] Both the reactive fluid 14 and the white inkjet ink 16 can applied using digital inkjet printing, such as thermal inkjet printing or piezoelectric inkjet printing. Any suitable inkjet applicator, such as a thermal inkjet printhead, a piezoelectric printhead, a continuous inkjet printhead, etc. may be used. In these examples, the reactive fluid 14 and the white inkjet ink 16 may be printed at desirable areas, and thus may be non-continuous. In other words, dried, treated textile fabric may contain gaps where no reactive fluid 14 or white inkjet ink 16 is printed.

[0134] In an example, the combination of the reactive fluid 14 and the white inkjet ink 16 are applied in an amount ranging from about 200 gsm to about 400 gsm. In another example, the combination of the reactive fluid 14 and the white inkjet ink 16 are applied in an amount ranging from about 200 gsm to about 350 gsm.

[0135] In other examples, the reactive fluid 14 can be applied using an analog method, including any of those described herein for applying the pre-treatment fluid 12, such as spraying and roll coating.

[0136] In some examples, multiple inkjet inks (including the white inkjet ink 16) may be inkjet printed onto the dried, treated textile fabric 18. In these examples, each of the other inkjet inks may include a pigment, an example of the polymeric binder, and the ink vehicle. Each of the inkjet inks may include a different colored pigment so that a different color (e.g., cyan, magenta, yellow, black, violet, green, brown, orange, purple, etc.) is generated by each of the inkjet inks.

[0137] While not shown in Fig. 2, the method 100 may also include thermally curing the print. The thermal curing of the print may be accomplished by applying heat to the print. In an example of the method 100, the thermal curing involves heating the print to a temperature ranging from about 80°C to about 200°C, for a period of time ranging from about 10 seconds to about 15 minutes. In another example, the temperature ranges from about 100°C to about 180°C. In still another example, thermal curing is achieved by heating the print to a temperature of 150°C for about 3 minutes.

[0138] Referring now to Fig. 3, a schematic diagram of a printing system 30 is depicted. The printing system 30 includes three zones A, B, C, including a pre treatment zone A, a printing zone B, and a curing zone C. [0139] The textile fabric/substrate 18 may be transported through the printing system 30 such that it is first fed to the pre-treatment zone A. In the pre-treatment zone A, an example of the pre-treatment fluid 12 is applied to the textile fabric 18.

In the example shown, the application of the pre-treatment fluid 12 is performed using a padding process. In this process, the textile fabric 18 can be soaked in a bath of the pre-treatment fluid 12 and the excess can be rolled out. Instead of soaking, dipping, spraying, or another analog application may be used. While the pre-treatment fluid 12 is shown on top of the textile fabric 18 in Fig. 3, the textile fabric 18 becomes impregnated with the pre-treatment fluid 12. After impregnation, the impregnated textile fabric 18 can be passed through padding nip rolls 22 under pressure. Examples of the padding nip rolls 22 may include a pair of soft rubber rolls, or one chromic metal hard roll and one tough-rubber synthetic soft roll. The amount of pressure that is applied may be controlled to leave a desired amount of the amount of pre-treatment fluid 12 on the textile fabric 18. In some examples, the pressure, that is applied ranges from about 10 PSI to about 150 PSI. In other examples, the applied pressure may range from about 30 PSI to about 70 PSI. [0140] The impregnated textile fabric 18, after nip rolling, can then be dried using any suitable heating mechanism 24. As described in reference to Fig. 2, heating may involve a temperature profile to initially remove excess fluid 12 and then dry the impregnated textile fabric 18. Heating may be accomplished for any functional time which is controlled, in part, by machine speed and the peak fabric temperature.

[0141] The impregnated textile fabric (shown as fabric 18 with a pre-treatment fluid layer 12’ thereon) is then transported through a printing zone B where an example of the reactive fluid 14 and the white inkjet ink 16 are sequentially applied onto the impregnated textile fabric 18 and 12’. In the printing zone B, the reactive fluid 14 and the white inkjet ink 16 are applied via inkjet printheads 26A and 26B to form respective fluid 14 and ink 16 layers. Multiple passes may be performed to form several alternating reactive fluid 14 and white inkjet ink 16 layers.

[0142] The alternating reactive fluid 14 and white inkjet ink 16 layers may be heated in the printing zone B (for example, the air temperature in the printing zone B may range from about 10°C to about 90°C) such that water may be at least partially evaporated from the alternating reactive fluid 14 and white inkjet ink 16 layers.

[0143] The impregnated textile fabric 18 and 12’ (having the alternating reactive fluid 14 and white inkjet ink 16 layers thereon) may then be transported to the curing zone C where the compositions/layers 14, 16 are heated to cure the print. Any heating mechanism 28, such as a dryer or an oven, may be used. The heat is sufficient to initiate cross-linking or other interactions that bind the white pigment onto the textile fabric 16. The heat to initiate fixation (thermal curing) may range from about 80°C to 200°C as described above. This process forms the printed article 34 including the image 32 formed on the textile fabric 18.

[0144] To further illustrate the present disclosure, examples are given herein. It is to be understood that these examples are provided for illustrative purposes and are not to be construed as limiting the scope of the present disclosure.

EXAMPLES

[0145] Example 1

[0146] Three different example white inks were prepared with the self-cross- linked polyurethane binder particles disclosed herein and with different white dispersions. Two commercially available white dispersions were used, including EMACOL™ SF White AH 2298F and EMACOL™ SF White AH 2084F. The third white dispersion was prepared with the formulation shown in Table 1. The ink formulations are shown in Table 2.

TABLE 1 - 3^rd White Dispersion

TABLE 2 - White Inks

Reflects pigment solids loading in final ink

^**reflects binder solids loading in final ink

[0147] These white inks were tested for printability. The inks were printed using a thermal inkjet printer, and both decap performance and decel performance were tested.

[0148] The term "decap performance," as referred to herein, means the ability of the white ink to readily eject from the printhead, upon prolonged exposure to air. The decap time is measured as the amount of time that a printhead may be left uncapped (i.e. , exposed to air) before the printer nozzles no longer fire properly, potentially because of clogging, plugging, or retraction of the colorant from the drop forming region of the nozzle/firing chamber. To test the decap performance, a reference line of the ink was printed from a printhead that was not uncapped (i.e., was not exposed to air). Then, the printhead was filled with the ink and left uncapped (i.e. , exposed to air) for a predetermined amount of time (e.g., 1 second or 7 seconds) before the ink was ejected again from the printhead. A score was then assigned to the ink based on the number of spits performed before a line with the same print quality as the reference line was printed. A lower decap score indicates higher quality firing of the nozzles and less clogging, plugging, or retraction of the colorant from the drop forming region of the nozzle/firing chamber. A decap score higher than 15 (> 15) indicates that a good line was not obtained after 15 spits. The results of the decap performance tests for each ink are shown in Table 3.

[0149] The term “decel,” as referred to herein, refers to a decrease in the drop velocity over time (e.g., 6 seconds) of ink droplets fired from an inkjet printhead. A large decrease in drop velocity (e.g., a decrease in drop velocity of greater than 0.5 m/s) can lead to poor image quality, which can be observed by the color difference between the print samples from continuously firing nozzles and the print samples from non-continuously firing nozzles. In contrast, inks that do not experience decel (i.e., no decrease in drop velocity) or experience an acceptable decel (e.g., a decrease in drop velocity of 0.5 m/s or less) will continue to generate quality printed images. In order to determine decel performance, each of the example inks were filled into a thermal inkjet print head and the drop velocity vs. firing time over 6 seconds was collected. The results of the decel performance tests for each ink are also shown in Table 3.

TABLE 3 - Printing Performance

[0150] The results shown in Table 3 indicate that the example white inkjet inks 1 and 3 have excellent printability. Ink 2 exhibited less desirable print performance. [0151] These white inks were also tested for stability.

[0152] Each example white ink was stored in an accelerated storage (AS) or accelerated shelf life (ASL) environment at a temperature of 60°C for one week. The viscosity, pH, and particle size of each example white ink was measured before and after the inks were stored in the AS environment.

[0153] The viscosity before and after storage in the AS environment of each of the white inkjet inks was measure at room temperature (25°C) using a Viscolite viscometer. Then the percent change (%D) in the viscosity was calculated for each ink.

[0154] The pH of each white inkjet ink was measured before and after the inks were stored in the AS environment. Then the change (D) in the pH was calculated for each ink.

[0155] The particle size for each example white ink was measured in terms of the volume-weighted mean diameter (Mv) and the D95 (i.e., 95% the population is below this value) using dynamic light scattering with a NANOTRAC® WAVE™ particle size analyzer (available from MICROTRAC™ - NIKKISO GROUP™).

Then the percent change (%D) in particle size was calculated for ink.

[0156] The results of the viscosity, pH, and particle size change are shown in Table 4.

TABLE 4 - AS Stability Results

[0157] Additionally, each white inkjet ink was put through a T-cycle. During the T-cycle, each white inkjet ink was heated to and maintained at a high temperature of 70°C for 4 hours, and then each ink was cooled to and maintained at a low temperature of -40°C for 4 hours. This process was repeated for each example white inkjet ink for 5 cycles. For each example white inkjet ink, the viscosity, pH, and particle size (in terms of Mv and D95) were measured before and after the T- cycle, and the change (pH) or percent change (viscosity, particle size) was calculated. The results are shown below in Table 5.

TABLE 5 - T-cycle Stability Results

[0158] The results shown in Tables 4 and 5 indicate that the example white inkjet inks 1 and 3 are stable. Ink 2 was less stable in terms of particle size change after AS and the T-cycle.

[0159] In this example, the jettability of the white inkjet inks was measured through a “Turn-On Energy (TOE) Curve”. The term “Turn-On Energy (TOE) curve,” as used herein, refers to the drop weight of the ink as a function of firing energy. An inkjet ink with good jettability performance also has a good TOE curve, where the ink drop weight rapidly increases (with increased firing energy) to reach a designed drop weight for the pen architecture used; and then a steady drop weight is maintained when the firing energy exceeds the TOE. In other words, a sharp TOE curve may be correlated with good jettability performance. In contrast, an inkjet ink with a poor TOE curve may show a slow increase in drop weight (with increased firing energy) and/or may never reach the designed drop weight for the pen architecture. A poor TOE curve may be correlated with poor jettability performance. The TOE curve for the example inkjet inks is shown in Fig. 4. As depicted, each of the example white inks exhibited a good TOE curve, indicating good jettability via thermal inkjet printheads. [0160] Example 2

[0161] Comparative prints 1 , 2 and 3 were generated, respectively, using example inks 1 , 2 and 3 from Example 1. These comparative prints were generated without any pre-treatment fluid or reactive fluid.

[0162] For the comparative prints, Gildan black heavy (780) cotton T-shirts were used as the textile fabric, and the white inks were printed directly on the fabrics (total of 300 gsm deposited over 6 passes using an 11 ng thermal inkjet printhead). [0163] The opacity and durability of the comparative prints were measured.

[0164] Opacity was measured in terms of L^*, i.e. , lightness (D50/2), of the comparative white prints. A greater L^* value indicates a greater opacity of the white ink on the colored textile fabric. In some examples disclosed herein, the textile fabric has an L^* ranging from about 0 to about 20, and the white image formed on the textile fabric has an L^* ranging from about 85 to about 100.

[0165] The durability of the comparative prints was assessed by its ability to retain color after being exposed to washing. This is also known as washfastness. Washfastness was measured in terms of a change in L^* before and after washing. Washfastness was also measured in terms of DE. The term “DE,” as used herein, refers to the change in the L^*a^*b^* values of a color (e.g., cyan, magenta, yellow, black, red, green, blue, white) after washing. L^* is lightness, a^* is the color channel for color opponents green-red, and b^* is the color channel for color opponents blue- yellow. The initial L^*a^*b^* values of the comparative prints were measured. Then, each comparative prints was washed 5 times in a Whirlpool Washer (Model WTW5000DW) with warm water (at about 40°C) and detergent. Each example and comp print was allowed to air dry between each wash. Then, the L^*a^*b^* values after the 5 washes of comparative print was measured.

[0166] The color change DE was calculated by:

The results of the opacity and washfastness tests for the comparative prints are shown in Table 6. TABLE 6 - Opacity and Washfastness for Comp. Prints

[0167] Example ink 1 from Example 1 was used with two different pre-treatment fluids and an example of the reactive fluid disclosed herein. The formulation of the pre-treatment fluids and reactive fluid are shown in Tables 7 and 8, respectively.

TABLE 7 - Pre-treatment Fluids

TABLE 8 - Reactive Fluid

Reflects cationic polymer solids loading in final ink

[0168] For the example prints, Gildan black heavy (780) cotton T-shirts were used as the textile fabric. For example print 1 , PT 1 was applied a Lab padder under the pressure of 50 PSI with a speed set of 2 on the machine. After padding, the fabric was dried using a box oven at 120°C for 15 minutes. For example print 2, PT 2 was applied a Lab padder under the pressure of 50 PSI with a speed set of 2 on the machine. After padding, the fabric was dried using a box oven at 120°C for 15 minutes.

[0169] The reactive fluid and white ink 2 were printed on the treated fabrics (total of about 55 gsm of the reactive fluid and about 295 gsm of white ink 2, deposited over 6 passes using an 11 ng thermal inkjet printhead). The prints were cured at 150°C for 3 minutes.

[0170] The opacity and durability of the example prints were measured as described above. The results of the opacity and washfastness tests for the comparative prints are shown in Table 9.

TABLE 9 - Opacity and Washfastness for Example Prints

[0171] Comparing the results for the example prints and the comparative prints, the durability was comparable, and the opacity (L^*) was improved by at least 10. [0172] The results in these examples demonstrate that the white inkjet inks are jettable via thermal inkjet printheads, and when printed with the reactive fluid and pre-treatment fluids disclosed herein, generated prints with desirable washfastness (durability) and improved opacity on black fabrics.

[0173] It is to be understood that the ranges provided herein include the stated range and any value or sub-range within the stated range, as if the value(s) or sub range^) within the stated range were explicitly recited. For example, a range from about 1 wt% to about 10 wt%, should be interpreted to include not only the explicitly recited limits of from about 1 wt% to about 10 wt%, but also to include individual values, such as about 1.15 wt%, about 2.5 wt%, 4.0 wt%, 6.77 wt%, 8.85 wt%, 9.33 wt%, etc., and sub-ranges, such as from about 2 wt% to about 5.65 wt%, from about 3 wt% to about 7 wt% from about 4.35 wt% to about 8.95 wt%, etc. Furthermore, when “about” is utilized to describe a value, this is meant to encompass minor variations (up to +/- 10%) from the stated value.

[0174] Reference throughout the specification to “one example”, “another example”, “an example”, and so forth, means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the example is included in at least one example described herein, and may or may not be present in other examples. In addition, it is to be understood that the described elements for any example may be combined in any suitable manner in the various examples unless the context clearly dictates otherwise.

[0175] In describing and claiming the examples disclosed herein, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

[0176] While several examples have been described in detail, it is to be understood that the disclosed examples may be modified. Therefore, the foregoing description is to be considered non-limiting.

Claims

What is claimed is:

1 . A fluid set, comprising: a pre-treatment fluid, including: a silicon-containing surface energy control agent; and an aqueous pre-treatment vehicle; a reactive fluid, including: a cross-linking agent; and an aqueous reactive fluid vehicle; and a white inkjet ink, including: a white pigment particle; a self-cross-linked polyurethane binder particle; and an aqueous ink vehicle.

2. The fluid set as defined in claim 1 wherein the self-cross-linked polyurethane binder particle includes non-ionic diamine cross-links and anionic diamine cross-links.

3. The fluid set as defined in claim 1 wherein the self-cross-linked polyurethane binder particle has an acid number less than 10, a weight average molecular weight ranging greater than 50,000, and a particle size ranging from about 200 nm to about 400 nm.

4. fluid set as defined in claim 1 wherein the white pigment particle is titanium dioxide, zinc oxide, zirconium oxide, or combinations thereof.

5. The fluid set as defined in claim 1 wherein the silicon-containing surface energy control agent is selected from the group consisting of a polydialkylsiloxane, an organosilicone terpolymer, a silylated organic polymer, a disiloxane, a trisiloxane, a tetrasiloxane, and combinations thereof.

6. The fluid set as defined in claim 1 wherein the cross-linking agent includes a cationic polymer selected from the group consisting of poly(dimethylamine-co-epichlorohydrin); a polyamide epichlorohydrin resin; a polyamine epichlorohydrin resin; and a combination thereof.

7. A textile printing kit, comprising: a textile fabric; a pre-treatment fluid, including: a silicon-containing surface energy control agent; and an aqueous pre-treatment vehicle; a reactive fluid, including: a cross-linking agent; and an aqueous reactive fluid vehicle; and a white inkjet ink, including: a white pigment particle; a self-cross-linked polyurethane binder particle; and an aqueous ink vehicle.

8. The textile printing kit as defined in claim 7, wherein the textile fabric is selected from the group consisting of polyester fabrics, polyester blend fabrics, cotton fabrics, cotton blend fabrics, nylon fabrics, nylon blend fabrics, silk fabrics, silk blend fabrics, wool fabrics, wool blend fabrics, and combinations thereof.

9. The textile printing kit as defined in claim 7, wherein the self-cross-linked polyurethane binder particle includes non-ionic diamine cross-links and anionic diamine cross-links.

10. The textile printing kit as defined in claim 9 wherein the self-cross-linked polyurethane binder particle has an acid number less than 10, a weight average molecular weight ranging greater than 50,000, and a particle size ranging from about 200 nm to about 400 nm.

11. The textile printing kit as defined in claim 7 wherein the white pigment particle is titanium dioxide, zinc oxide, zirconium oxide, or combinations thereof.

12. The textile printing kit as defined in claim 7 wherein the silicon- containing surface energy control agent is selected from the group consisting of a polydialkylsiloxane, an organosilicone terpolymer, a silylated organic polymer, a disiloxane, a trisiloxane, a tetrasiloxane, and combinations thereof.

13. The textile printing kit as defined in claim 7 wherein the cross-linking agent includes a cationic polymer selected from the group consisting of poly(dimethylamine-co-epichlorohydrin); a polyamide epichlorohydrin resin; a polyamine epichlorohydrin resin; and a combination thereof.

14. A printing method, comprising: applying a pre-treatment fluid to a textile fabric to form a treated textile fabric, the pre-treatment fluid including: a silicon-containing surface energy control agent; and an aqueous pre-treatment vehicle; and sequentially printing a reactive fluid and a white inkjet ink on the treated textile fabric, the reactive fluid including: a cross-linking agent; and an aqueous reactive fluid vehicle; and the white inkjet ink including: a white pigment particle; a self-cross-linked polyurethane binder particle; and an aqueous ink vehicle.

15. The method as defined in claim 14, further comprising drying the treated textile fabric before sequentially printing the reactive fluid and the white inkjet ink.