HK1129695B - Inkjet ink solvent system - Google Patents

Description

Inkjet ink solvent system

Background

Ink jet printing has become a common method of recording images on various media surfaces, particularly paper, for a number of reasons, including low printer noise, the ability to record at high speeds, and the ability to record in multiple colors. Moreover, these advantages of inkjet printing can be achieved at a lower price for the consumer. While significant advances have been made in inkjet printing technology, with these advances, consumer demands such as higher speed, higher resolution, full color image formation, higher stability, etc. have increased.

With respect to the chemistry of inkjet inks, commercial inkjet inks are mostly water-based. Thus, their components are usually water-soluble (as is the case in many dyes) or water-dispersible (as is the case in many pigments). Because of their water-based nature, inkjet ink systems often tend to exhibit poor image fade and durability when exposed to water or high humidity environments as compared to other photographic or printing methods.

Significant advances in the water resistance of inkjet inks have been achieved by the incorporation of certain polymeric colloids which are compatible with the inkjet ink. However, many inkjet inks still exhibit undesirable optical density, durability, and/or (wet smear) resistance in response to highlighters. In particular, alkaline highlighters are particularly detrimental to conventional printed images because alkaline highlighters inks can dissolve inkjet inks containing an alkali soluble binder.

Summary of The Invention

In one aspect of the present system and method, the smear resistant ink-jet ink formulation comprises 0.1-6% colorant, 1-40% solvent, 0.3-10% latex binder having a particle size of 100-.

Brief description of the drawings

The accompanying drawings illustrate various embodiments of the present system and method and are a part of the specification. The described embodiments are merely examples of the present system and method and do not limit the scope of the invention.

FIG. 1 is a simplified block diagram illustrating an inkjet material dispensing system according to one exemplary embodiment.

In the drawings, like reference numbers indicate similar, but not necessarily identical, elements.

Detailed Description

Before particular embodiments of the present system and method are disclosed and described, it is to be understood that the present system and method are not limited to the particular process and materials disclosed herein as such may vary to some degree. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present system and method will be limited only by the appended claims and equivalents thereof.

In this specification and the appended claims, the following terms are used:

the term "decap" is a measure of the length of time that a nozzle remains dormant until it becomes clogged. Similarly, the term "decap splash" shall be defined as the number of inkjet configuration firings (firings) required to reestablish proper drop ejection after a blockage occurs due to remaining inactive.

The term "2-time HL (2Pass HL)" is understood to mean the amount of ink transfer (in Optical Density (OD)) that occurs when an 1/8 "wide print line is scratched twice with a Sanford major Accent fluorescence Yellow highlighter.

The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a pigment" includes reference to one or more of such substances.

The terms "about" and "approximately" when referring to a numerical value or range are meant to encompass the values resulting from experimental error that can occur when taking measurements.

As used herein, "liquid vehicle" is defined to include liquid compositions that can be used to carry colorants (including pigments) to a substrate. Liquid vehicles are well known in the art and a variety of liquid vehicle components may be used in accordance with embodiments of the present systems and methods. These liquid vehicles may include a mixture of a variety of different agents, including but not limited to surfactants, co-solvents, buffers, biocides, viscosity modifiers, sequestering agents, stabilizing agents, and water. Although not liquid in nature, the liquid vehicle may also carry other solids, such as polymers, uv-curable materials, plasticizers, salts, and the like.

As used herein, "colorant" may include dyes, pigments, dye/pigment mixtures, and/or other particles that may be suspended or dissolved in the ink medium. Dyes are generally water soluble and, therefore, can be used in many embodiments as desired. However, pigments may also be used in other embodiments. Pigments that may be used include self-dispersed pigments and non-self-dispersed pigments. Self-dispersed pigments include those pigments that have been chemically surface modified by charge or polymer groups. The chemical modification helps the pigment to begin and/or substantially remain dispersed in the liquid vehicle. The pigment may also be a non-self-dispersing pigment utilizing a separate and free dispersant (which may be, for example, a polymer, oligomer, or surfactant) in the liquid vehicle or physically coated on the surface of the pigment.

The term "latex" or "latex dispersion" includes latex particulates and the aqueous medium in which the latex particulates are dispersed. More specifically, a latex is a suspension comprising a liquid (e.g., water and/or other liquid) and polymer microparticles having a particle size of 20 nm to 500 nm (preferably 100 nm to 300 nm). Typically, the polymer microparticles are present in the liquid in an amount of from 0.3 wt% to 10 wt%. Such polymeric microparticles may comprise a large amount of monomers that are generally randomly polymerized, and also crosslinkable. Additionally, in one embodiment, the latex component has a glass transition temperature of about-20 ℃ to +100 ℃.

Concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a weight range of about 1 wt% to about 20 wt% should be interpreted to include not only the explicitly recited concentration limits of 1 wt% to about 20 wt%, but also include individual concentrations such as 2 wt%, 3 wt%, 4 wt%, and sub-ranges such as 5 wt% to 10 wt%, 10 wt% to 20 wt%, etc.

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present system and method, in order to produce and use a solvent system for durable latex and adhesive mixtures. It will be apparent, however, to one skilled in the art that the present method may be practiced without these specific details. Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

Exemplary Structure

FIG. 1 illustrates an exemplary system (100) that may be used to apply an inkjet ink (160) to an ink receiving medium (170) according to one exemplary embodiment. As shown in FIG. 1, the system includes a computing device (110) that is controllably coupled to a moveable carriage (140) via a servo mechanism (120), the carriage (140) having an inkjet dispenser (150) disposed thereon. The material reservoir (130) is also coupled to the movable support (140) and thus to the ink jet print head (150). A plurality of rollers (180) are positioned adjacent the ink jet dispenser (150), the dispenser (150) being configured to selectively position the ink jet receiving medium (170). While the exemplary system (100) of the present invention is described in the context of applying an inkjet ink (160) to an ink receiving medium (170), any number of objects may be marked with the inkjet ink of the present invention using the present system and method. The above-described components of the present exemplary system (100) will now be described in more detail.

As shown in fig. 1, a computing device (110) controllably coupled to the servo mechanism (120) controls selective deposition of inkjet ink (160) onto an ink receiving medium (170). The representation of the desired image or text may be formed using a program hosted by the computing device (110). The representation is then converted into servo instructions contained in a processor readable medium (not shown). When accessed by the computing device (110), instructions in a processor-readable medium are used to control the servo mechanism (120) and the moveable carriage (140) and inkjet dispenser (150). The computing device (110) shown in FIG. 1 may be, but is not limited to, a workstation, a personal computer, a laptop computer, a Personal Digital Assistant (PDA), or any other processor-containing device.

The moveable support (140) of the printing system (100) of the present invention shown in fig. 1 is a moveable material dispenser that can include any number of inkjet material dispensers (150) for dispensing inkjet inks (160) of the present invention. The movable carriage (140) is controllable by the computing device (110) and may be controllably moved, for example, by a shaft system, a belt system, a chain system, etc., to form the servo mechanism (120). The computing device (110) may inform the user of the operating conditions and provide a user interface to the user while the mobile carriage (140) is operating.

In printing an image or text onto an ink receiving medium (170), the computing device (110) may controllably position the movable carriage (140) to direct one or more of the inkjet dispensers (150) to selectively dispense the inkjet ink as digitally addressed drops onto predetermined locations on the ink receiving medium (170) to form the desired image or text. The ink-jet material dispenser (150) used in the printing system (100) of the present invention can be any type of ink-jet dispenser useful for performing the methods of the present invention, including, but not limited to, thermally-actuated ink-jet dispensers, mechanically-actuated ink-jet dispensers, electrostatically-actuated ink-jet dispensers, magnetically-actuated dispensers, piezoelectrically-actuated dispensers, continuous ink-jet dispensers, and the like.

A material reservoir (130) in fluid communication with the inkjet material dispenser (150) contains the inkjet ink (160) of the present invention prior to printing. The material reservoir can be any container or containers that seal the inkjet ink (160) prior to printing, and can be constructed of a variety of materials, including but not limited to metal, plastic, composite, or ceramic. As shown in fig. 1, the material reservoir (130) may be separate from but in fluid communication with the inkjet material dispenser (150). Alternatively, the material reservoir (130) may be directly coupled to the ink-jet material dispenser (150) as part of the dispenser.

FIG. 1 also shows the components of the present system that aid in receiving the inkjet ink (160) on an ink receiving medium (170). As shown in FIG. 1, a plurality of positioning rollers (180) may transport and/or position the ink receiving medium (170) during printing. Alternatively, various belts, rollers, substrates, or other transport devices may be used to transport and/or position the ink receiving medium (170) during printing, as is well known in the art. In addition, various thermal pickup rollers (not shown), thermal fans (not shown), or radiation devices (not shown) may be used to apply thermal energy to fix the image on the ink receiving medium.

Inkjet inks are typically formulated with various organic polymers to improve highlighter smear. These polymers are typically styrene-acrylics, polyurethanes, and polyesters that are soluble or colloidal in water. However, the hydrophobic character of the binders typically used to obtain good highlighter smear makes the reliability and stability of these inkjet inks problematic.

Thus, the exemplary anionic ink systems of the present invention provide near laser (near laser) resistance to highlighter smear and wet smear on office paper while maintaining high stability in solution. The formation and composition of the anionic inkjet ink (160) of the present invention will be described in detail below.

Exemplary compositions

In accordance with the present system and method, a system for printing an image on a substrate can include an inkjet ink (160) and a printhead or other material dispenser (150) loaded with the inkjet ink. According to one exemplary embodiment, the ink-jet ink of the present invention can comprise an anionic ink system and a cationic fixer fluid. More specifically, according to one exemplary embodiment, an exemplary inkjet ink of the present invention may include: anionic inks comprising a colorant, such as a dye or pigment; a solvent system comprising 2-pyrrolidone and 1, 2-hexanediol; water; and various binders including, but not limited to, hydrophobic styrene-acrylic or acrylic resins and/or combinations of polyurethane resins and latex binders. According to one exemplary embodiment, the styrene-acrylic resins described below have an acid value of about 50 to about 250 and a molecular weight of about 1000-. When the polyurethane resin is contained, the acid value of the polyurethane resin is 40-200 and the molecular weight is 3000-400,000. In addition, the latex binder component of the exemplary binder assembly has a particle size of about 100-300 nm and a glass transition temperature of-20 to +100 ℃. Additionally, according to one exemplary embodiment, the inkjet ink system of the present invention may include a cationic fixer fluid for fixing the ink to a desired substrate. According to an exemplary embodiment, the cationic fixative includes, but is not limited to, a crashing agent (crasing agent), such as an acid, a metal salt, or a cationic polymer. In accordance with the above components, the exemplary inkjet ink compositions of the present invention may include various surfactants, buffers, biocides, sequestering agents, viscosity modifiers, humectants, stabilizers, and/or other known additives. The above-described respective inkjet ink components will be described in more detail below.

Hydrophobic styrene-acrylic acids

As noted above, exemplary inkjet ink systems of the present invention include a hydrophobic styrene-acrylic or acrylic binder having an acid value of 50-250 and a molecular weight of about 1000-60,000. According to one exemplary embodiment, the styrene-acrylic or acrylic binder may include, but is not limited to, styrene-acrylic or acrylic binders having an acid number of less than about 220 sold under the trade name Acronal by BASF (BASF), Joncryl 678 acrylic resin of john Polymer (Johnson Polymer) having an acid number of 215, and/or acrylic binder emulsions such as DFC 3030 of john Polymer or Joncryl 624 acrylic emulsions of john Polymer having acid numbers of 64 and 50, respectively. Additionally, styrene-acrylic resins such as Joncryl 586 and other Joncryls or SMA resins may also be used.

Polyurethane (PU) resin

When a polyurethane resin is used in combination with the latex binder, the polyurethane resin has an acid value of 40-200 and a molecular weight of 3000-400,000. Specifically, according to one exemplary embodiment, the polyurethane resin may include, but is not limited to, commercially available polyurethane resins, such as, for example, Avecia PU resin; u520, U712, U910 and U40 of Alberdingk-Boley PU resin; BASF PU resin Luviset p.u.r; and CromptonPU resins Witcobond W-232 and W-236.

Latex adhesive

In addition to the styrene-acrylic or acrylic binder described above, exemplary inkjet ink systems of the present invention include a latex binder having a particle size of about 100 and 300 nanometers and a glass transition temperature of about-20 to +100 ℃.

According to one exemplary embodiment, the latex binder component of the present exemplary inkjet ink includes various polymer microparticles in the form of a latex dispersion. The inclusion of the latex may improve the durability of an image formed later.

According to one exemplary embodiment, the latex particulates included in the inkjet ink of the present invention may include latex particulates having surface acid groups. In particular, latex particulates having surface acid groups can remain stable for extended periods of time, often resisting agglomeration. Thus, in one exemplary embodiment, neutralized surface acid groups may be present on the latex particulates. These acid groups may be present throughout the latex particle (including on the surface), or may be present more centrally on the surface. In a more specific aspect, the latex particulates can be prepared using acid monomers copolymerized with other monomers to form latex polymers. The acid functionality is neutralized to impart a surface charge to the latex particles. In this exemplary embodiment, the acid monomer is present in an amount of about 0.5 to 10 weight percent of the total monomers forming the latex polymer. Typical acids used to acidify the surface of the latex particulates include carboxylic acids, although stronger acids may also be used. Carboxylic acids are weak acids that have been quite effective for use in latex/inkjet ink systems. For example, about 6 weight percent methacrylic acid may be used to form the methacrylic acid functionalized latex particulates.

In another exemplary embodiment, the latex particulates may be provided by copolymerizing a plurality of monomers to form the latex particulates, the plurality of monomers including at least one crosslinking monomer present in an amount of about 0.1 wt% to about 3 wt% of the total monomers used to form the latex particulates. Such crosslinking monomers do not provide acid groups, but may provide other properties to the latex that are desirable for ink jet applications.

Specific examples of latex particulates that can be used include those prepared using emulsion monomer mixtures of styrene, hexyl methacrylate, ethylene glycol dimethacrylate, and methacrylic acid in various weight ratios, which monomers are copolymerized to form the latex. Typically, styrene and hexyl methacrylate monomers provide the bulk of the latex particulates with which ethylene glycol dimethacrylate and methyl methacrylate may be copolymerized in lesser amounts. According to this exemplary embodiment, the acid group is provided by methacrylic acid. Although examples of such latex particulates are provided, other combinations of monomers may be similarly used to form the latex particulates. Exemplary monomers that may be used to form the latex particulates of the exemplary systems and methods of the present invention include, but are not limited to, styrene, C1-C8 alkyl methacrylates, C1-C8 alkyl acrylates, ethylene glycol methacrylates and dimethacrylates, methacrylic acid, acrylic acid, and the like.

Other aspects of the latexes of the present exemplary systems and methods may include properties such as desired glass transition temperature and particle density. For example, in one exemplary embodiment, the polymer glass transition temperature of the latex particulates used in the present exemplary systems and methods may be from about-20 ℃ to +100 ℃ for inks that print at room temperature. The glass transition temperature of the latex may contribute to the desired ink performance in terms of thermal shear stability, deceleration, decap, particle settling, and co-solvent resistance.

Coloring agent

According to one exemplary embodiment, the present exemplary inkjet ink system includes from about 0.1 vol% to about 6 vol% colorant. In particular, the present exemplary inkjet ink systems may include various anionic dyes and/or pigments or dye/pigment mixtures.

Examples of suitable anionic dyes include various water-soluble acid dyes and direct dyes. Specific examples of anionic dyes include Direct Yellow (Direct Yellow)86, Acid Red (Acid Red)249, Direct Blue (Direct Blue)199, Direct Black (Direct Black)168, Direct Yellow 132, reactive Black (reactive Black)31, Direct Yellow 157, reactive Yellow 37, Acid Yellow 23, reactive Red 180, Acid Red 52, Acid Blue 9, Direct Blue 86, reactive Red 4, reactive Red 56, Acid Red 92, reactive Red 31, and Pro-Jet series dyes (available from Avecia Ltd.), including Pro-Jet Yellow I, Pro-Jet magenta I, Pro-Jet cyan I, Pro-Jet Black I, and Pro-Jet Yellow 1-G; aminyl Bright Red (Brilliant Red) F-B (Simitoo Chemical Co.); dessen line "salt free" dyes available from Hoechst (Hoechst) such as Dessen direct Black HEF-SF, Dessen Black RL-SF, Dessen direct yellow 6G-SF VP216(, Dessen Brilliant yellow GL-SF VP220, Dessen acid yellow XX-SF VP413, Dessen Brilliant Red F3B-SF VP218, Dessen Rhodamine (Rhodamine) B-SF VP353, Dessen direct Green pine Blue (Turquose Blue) FRL-SF VP368, and Dessen acid Blue AE-VP 344; mixtures thereof; and the like. other examples include Terre-ken (pont) acid Red 52, Terre-ken direct Red 227, and Terre-ken acid yellow 17 (Terre-ken color corporation (Tricon Colors, acid Red (Berney) 2, Brand-Brillid-Blue A34, Brillid-Brilliant Blue A-34, pontamine, Food (Food) Black 2, Cato direct Green pine Color (direct Turquoise) FBLSupra Conc., Carolina Color and Chemical), Special Fast Green pine Color (Fast Turquoise)8GL Liquid, Mobay Chemical), lntra in combination with Green pine Color Liquid (bond Liquid Turquoise) GLL, Crompton and Knowles, Cibracon Bright Red 38-A, Aldrich Chemical (Aldrich Chemical)), Drimarene Bright Red X-2B, Pymam, Inc., Levafix Bright Red E-4B (Mobay Chemical)), Levax Bright Red E-6BA (Mobai Chemical), Pymam Ceiff D & C Red (Red 28, Pymam direct Bri Red (mountain Bri Chemical)), Levax Bright Red E-6BA (yellow Bri yellow Fa. C & D & C & D & C & D & C & D & C & G & D & G & D, cartasol yellow GTF liquid specialty 110 (Zadok Company), D & C yellow #10 (yellow 3, Terrakin), yellow gradient (Shade)16948 (Terrakin), Basacid black X34(BASF), Carta Black 2GT (Zadoz Company), Neozapon Red 492(BASF), Orasol Red G (Ciba-Geigy)), direct Bright peach Red B (Crompton-Knolls), Aizen Spilon Red C-BH (Hodagaya Chemical Company), Kayanol Red 3BL (Nippon Kayaku Company), Levanol Bright Red 3BW (Mobay Chemical Company (Mobay Company)), Levaderm lemon yellow (Aizen Chemical Company), Aizen Spran yellow 167 (Sizary yellow), Sizary yellow G (Red), Orasol black RLP (CGTakara-3G), Oryza yellow RLp-4 (Oryza yellow-Gray Company), savinyl black RLS (prandoz), dermocaron 2GT (prandoz), Pyrazol black BG (ICI america), Morfast black Conc a (Morton-Thiokol), Diazol black RN Quad (ICI america), Orasol blue GN (babar-giry), Savinyl blue GLS (prandoz corporation), Luxol blue MBSN (Morton-Thiokol), Sevron blue 5GMF (ICI america), and Basacid blue 750 (BASF); levafix brilliant yellow E-GA, Levafix yellow E2RA, Levafix black EB, Levafix black E-2G, Levafix black P-36A, Levafix black PN-L, Levafix brilliant red E6BA, and Levafix brilliant blue EFFA, all of which are available from Bayer (Bayer); procion green pine color PA, Procion green pine color HA, Procion green pine color Ho5G, Procion green pine color H-7G, Procion red MX-5B, Procion red H8B, Procion red MX8B GNS, Procion red G, Procion yellow MX-8G, Procion black H-EXL, Procion black P-N, Procion blue MX-R, Procion blue MX-4GD, Procion blue MX-G, and Procion blue MX-2GN, all from ICI USA; cibacron Red F-B, Cibacron Black BG, Lanasol Black B, Lanasol Red 5B, Lanasol Red B, and Lanasol yellow 46, all of which are available from Cibacron-Girrill; baslien Black P-BR, Baslien yellow EG, Baslien Brilliant P-3GN, Baslien yellow M-6GD, Baslien Brilliant Red P-3B, Baslien Scarlet (Scarlet) E-2G, Baslien Red E-B, Baslien Red E-7B, Baslien Red M-5B, Baslien blue E-R, Baslien Brilliant blue P-3R, Baslien Black P-BR, Baslien Green pine blue P-GR, Baslien Green pine M-2G, Baslien Green pine E-G, and Baslien Green E-6B, all from BASF; sumifix turquoise blue G, Sumifix turquoise blue H-GF, Sumifix Black B, Sumifix Black H-BG, Sumifix yellow 2GC, Sumifix Supra scarlet 2GF, and Sumifix Bright Red 5BF, all available from Simatoo Chemical Company; lntracron yellow C-8G, lntracron red C-8B, lntracron green piny blue GE, lntracron green piny color HA, and lntracron black RL, all of which are available from Kremen and Nowey Dyes and chemical Division (Cromptons and Knowles, Dyes and Chemicals Division); Pro-Jet 485; magenta 377; mixtures thereof; and so on. These lists are merely exemplary and should not be construed as limiting the present invention.

Similarly, suitable pigments can be black pigments, white pigments, cyan pigments, magenta pigments, yellow pigments, and the like. Further, the pigment may be organic or inorganic particles as is well known in the art. Suitable inorganic pigments include, for example, carbon black. However, other inorganic pigments are also suitable, such as titanium dioxide, cobalt blue (CoO-Al)₂O₃) Chrome yellow (PbCrO)₄) And iron oxide. Suitable organic pigments include, for example, azo pigments (including disazo pigments and monoazo pigments), polycyclic pigments (e.g., phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, perylene pigments, perynone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments (isoindolinone pigments), pyranthrone pigments and quinophthalone pigments), insoluble dye chelates (e.g., basic dye chelates and acidic dye chelates), nitro pigments, nitroso pigments, and the like. Representative examples of phthalocyanine blues include copper phthalocyanine Blue and derivatives thereof (Pigment Blue 15). Representative examples of quinacridones include pigment orange 48, pigment orange 49, pigment red 122, pigment red 192, pigment red 202, pigment red 206, pigment red 207, pigment red 209, pigment violet 19 and pigment violet 42. Representative examples of anthraquinones include pigment Red 43, pigment Red 194(Perinone Red), pigment Red 216 (Brominated Pyranthrone Red) and pigment Red 226 (Pyranthrone Red). Substituted peryleneIllustrative examples include pigment Red 123 (Vermilion), pigment Red 149 (Scarlet), pigment Red 179 (Maroon), pigment Red 190 (Red), pigment Violet 19, pigment Red 189 (Yellow Shade Red) and pigment Red 224. Representative examples of thioindigoids include pigment Red 86, pigment Red 87, pigment Red 88, pigment Red 181, pigment Red 198, pigment Violet 36, and pigment Violet 38. Representative examples of heterocyclic yellows include pigment yellow 1, pigment yellow 3, pigment yellow 12, pigment yellow 13, pigment yellow 14, pigment yellow 17, pigment yellow 65, pigment yellow 73, pigment yellow 74, pigment yellow 151, pigment yellow 117, pigment yellow 128, pigment yellow 138, pigment yellow 155, pigment yellow 83, and pigment yellow 213. Such pigments are commercially available in powder or pressed cake form from a number of sources, including basf Corporation, nehadard Corporation (Engelhard Corporation), and Sun chemical Corporation (Sun chemical Corporation).

Examples of black pigments that can be used include carbon pigments. The carbon pigment can be almost any commercial carbon pigment that provides acceptable optical density and printing properties. Carbon pigments suitable for use in the present system and method include, but are not limited to, carbon black, graphite, glassy carbon, charcoal, and combinations thereof. Such carbon pigments can be produced by various known methods such as a tank process, a contact process, a furnace process, an acetylene process or a thermal process, and also can be purchased from manufacturers such as Cabot (Cabot) corporation, Columbian chemical Company, Degussa AG and dupont de Nemours and Company. Suitable carbon BLACK pigments include, but are not limited to, Cabot (Cabot) pigments such as MONARCH1400, MONARCH 1300, MONARCH 1100, MONARCH 1000, MONARCH 900, MONARCH 880, MONARCH 800, MONARCH 700, CAB-O-JET 200, CAB-O-JET 300, REGAL, BLACK PEARLS, ELFTEX, MOGUL, and VULCAN pigments; colombian (Columbian) pigments such as RAVEN 7000, RAVEN 5750, RAVEN 5250, RAVEN 5000 and RAVEN 3500; degussa pigments such as Color Black (Color Black) FW200, RAVEN FW2, RAVEN FW2V, RAVEN FW1, RAVEN FW18, RAVENs160, RAVEN FW S170, specialty Black (Special Black)6, specialty Black (Special Black)5, specialty Black (Special Black)4A, specialty Black (Special Black)4, pranex U, pranex 140U, pranex V, and pranex 140V; and TIPURE R-101 from DuPont. The pigments described above include unmodified pigment particulates, small molecule attached pigment particulates, and polymer dispersed pigment particulates.

Similarly, many types of color pigments can be used in the systems and methods of the present invention, and thus the following list is not limiting. For example, the colored pigment can be a blue, brown, cyan, green, white, violet, magenta, red, orange, yellow pigment, and mixtures thereof. The following color pigments are available from Cabot (Cabot) corporation: CABO-JET 250C, CABO-JET 260M, and CABO-JET 270Y. The following color pigments are available from basf: PALIOGEN orange, PALIOGEN orange 3040, PALIOGEN blue L6470, PALIOGEN violet 5100, PALIOGEN violet 5890, PALIOGEN yellow 1520, PALIOGEN yellow 1560, PALIOGEN red 3871K, PALIOGEN red 3340, HELIOGEN blue L6901F, HELIOGEN blue NBD 7010, HELIOGEN blue K7090, HELIOGEN blue L7101F, HELIOGEN blue L6900, L7020, HELIOGEN blue D6840, HELIOGEN blue D7080, HELIOGEN green L8730, HELIOGEN green K8683, and HELIOGEN green L9140. The following pigments were purchased from Ciba-Geigy Corp: CHROMOPHTAL yellow 3G, CHROMOPHTAL yellow GR, CHROMOPHTAL yellow 8G, IGRAZIN yellow 5GT, IGRALITE Gem Red (Rubine)4BL, IGRALITE blue BCA, MONASTRAL magenta, MONASTRAL scarlet, MONASTRAL Violet R, MONASTRAL Red B, and MONASTRAL Violet Castanea (Violet Maroon) B. The following pigments were purchased from charged cloth (Heubach Group): DALAMAR yellow YT-858-D and HEUCOPHTHAL blue GXBT-583D. The following pigments were purchased from Hoechst Specialty Chemicals: permanent yellow GR, Permanent yellow G, Permanent yellow DHG, Permanent yellow NCG-71, Permanent yellow GG, Hansa yellow RA, Hansa brilliant yellow 5GX-02, Hansa yellow-X, NOVOPERM yellow HR, NOVOPERM yellow FGL, Hansa brilliant yellow 10GX, Permanent yellow G3R-01, HOSTAPERM yellow H4G, HOSTAPERM yellow H3G, HOSTAPERM orange GR, HOSTAPER scarlet GO, HOSTAPERM pink E, Permanent gemstone red (Permanent Rubine) F6B, and HOSTAFINE series. The following pigments were purchased from Mobai corporation: quinodo magenta, indoast brilliant scarlet, quinodo red R6700, quinodo red R6713, and indoast violet. The following pigments were purchased from Sun Chemical Corp: l74-1357 yellow, L75-1331 yellow, and L75-2577 yellow. Other examples of pigments may include Normandy magenta RD-2400, permanent violet VT2645, Argyle green XP-111-S, bright green Toner (Toner) GR0991, Sudan (Sudan) blue OS, PV fast blue B2GO1, Sudan III, Sudan II, Sudan IV, Sudan orange G, Sudan orange 220, Ortho orange OR2673, Lithol fast yellow 0991K, Paliotol yellow 1840, Lumogen yellow D0790, Suco-Gelb L1250, Suco-yellow D1355, Fanal peach D4830, Cinqasia magenta, Lithol scarlet D3700, toluidine red, scarlet (for Thermoplast NSD PA), E.D. toluidine red, Lithol ruby red Toner, Lithol scarlet 4440, Lithan red C, Royal red 8192, Oracle red peach 4300, and Lithol scarlet L4300. These pigments are commercially available, for example, from Hoechst Celanese Corporation, Pileryanchi (Paul Uhlich), Basff (BASF), American Hoechst (American Hoechst), Qiba-Jiri (Ciba-Geigy), Adirech (Aldrich), DuPont (DuPont), Canada Ubberman (Ugine Kuhlman of Canada), domino Color Company (Dominion Color Company), Mader (Magruder), and Masson (Matheson). Examples of other suitable color pigments are described in The Colour Index, 3 rd edition (The Society of Dyers and Colourists, 1982).

Other pigments not specifically listed are also suitable for use in the exemplary systems of the present invention. The above pigments may be used alone, or in combination of two or more kinds, or in combination with an anionic or nonionic dye. Generally, the pigments of the present systems and methods can be from about 10 nanometers to about 10 micrometers, and in one aspect, can be from 10 nanometers to about 500 nanometers in diameter, although sizes outside this range can be used if the pigment remains dispersed and provides sufficient color properties. In one particular aspect of the present system and method, the pigment is present in the ink-jet ink composition in an amount of from about 1% to about 6% by weight.

Additionally, according to one exemplary embodiment described above, the polymer is attached to a pigment, such as a polymer-attached pigment of cabot. According to this exemplary embodiment, incorporation of the polymer-attached pigment may reduce or even eliminate the use of a fixative or pretreatment of the desired substrate. According to one exemplary embodiment, the polymer-attached pigment may include, but is not limited to, any pigment having a polymer attachment, wherein the polymer is a styrene-acrylic resin having an acid value of 50 to 250 and a molecular weight of about 1,000 to 60,000.

Solvent(s)

The exemplary inkjet ink system of the present invention also includes about 1-40% solvent. According to one exemplary embodiment, the solvent consists essentially of 2-pyrrolidone and 1, 2-hexanediol, or other typical volatile solvents having a vapor pressure above about 0.01mmHg at 25 ℃. These typically fast solvents exhibit fast evaporation rates, resulting in improved throughput and printing rates. While the above solvents primarily comprise volatile solvents having a vapor pressure above about 0.01mmHg at 25 deg.C, the remaining portion of the solvent may comprise solvents having a vapor pressure below 0.01mmHg at 25 deg.C, including but not limited to ethoxylated glycerol (LEG-1).

In particular, the solvent may also include, but is not limited to, ethoxylated glycerol; 2-methyl-1, 3-propanediol; 2-methyl-2, 4-pentanediol; 1, 5-pentanediol; 2-pyrrolidone; 1- (2-hydroxyethyl) -2-pyrrolidone; 2-ethyl-2-hydroxymethyl-1, 3-propanediol; diethylene glycol; 3-methoxybutanol; and 1, 3-dimethyl-2-imidazolidinone. The solvent may also include, but is not limited to, 1, 2-hexanediol; 1, 2-octanediol; 2, 5-dimethyl-3-hexyne (hexyne) -2, 5-diol; trimethylolpropane; 3-hexyne-2, 5-diol; sulfolane; 3-pyridylmethanol; and other pyridine derivatives. In addition, the solvent may impart properties required for the pigment-based ink of the present invention. More particularly, a solvent may be added to reduce the rate of evaporation of water during the ink jetting process, thereby minimizing clogging or affecting other properties of the ink such as viscosity, pH, surface tension, optical density, and print quality.

Water (W)

As noted above, the remaining components in the exemplary inkjet ink systems of the present invention include water.

In addition to water, the remaining components of the present exemplary inkjet ink systems may include various types of buffers and/or biocides. Any commonly known buffering agent can be used to establish the desired pH level in the inkjet ink system. In addition, various biocides can be used to inhibit the growth of undesirable microorganisms. Some examples of suitable biocides include, but are not limited to, benzoate, sorbate, commercial products such as nuosept (isp), ucarcide (dow), VANC1DE (RT Vanderbilt Co.) and proxel (avecia), and other known biocides. Typically, such biocides comprise less than about 5 wt% of the ink-jet ink composition, and typically from about 0.05 wt% to about 2 wt%.

Cationic fixative fluid

As noted above, cationic fixing fluids can also be used in conjunction with the present exemplary inkjet ink systems to fix the ink on a desired substrate. According to an exemplary embodiment of the present invention, the cationic fixative fluid may be a solution composition comprising a liquid vehicle and a "collision agent". According to one exemplary embodiment, the combination of the liquid vehicle and the colliding agent may be chemically stable, useful for inkjet printing. The collision agent may be a cationic polymer, a polyvalent metal ion or ionic group, and/or an organic acid. The crashing agent is typically deposited (overprinted or underprinted) on the substrate along with at least one of the constituent components of the associated inkjet ink. The constituent component which precipitates with the collision agent may be, for example, an anionic dye or a polymer.

According to one exemplary embodiment, the fixer composition may be stored separately from the inkjet ink, and the fluid dispensing system may be designed to overprint or underprint the fixer composition relative to the inkjet ink. Further, the exemplary inkjet ink and cationic fixer fluid of the present invention may be located in two separate inkjet pens, or may be located in two separate reservoirs of a common inkjet pen. In another exemplary embodiment, the cationic fixative fluid may be applied to the desired substrate in a pretreatment operation, wherein the desired substrate is completely coated with the cationic fixative fluid or other fixation element.

According to exemplary embodiments of the present invention, the crashing agent included in the cationic fixing fluid may be any single chemical or several chemicals combined in a fixer composition capable of promoting the dissolution or precipitation of one or more components of the inkjet ink. Precipitation of anionic dyes can affect the water resistance of inkjet images. Precipitation of non-colorants such as anionic surfactants may be beneficial for bleed control. Desolventizing can be accomplished by collision or close proximity-induced proton transfer of the collision agent with the colorant and/or other inkjet ink components, or by collision-induced component association and/or component association with the collision agent. Other collision or reaction mechanisms may also occur.

As described above, according to one exemplary embodiment, the collision agent may be, for example, a cationic polymer, a multivalent ion or ionic group, or an acid. Many possible collision agents in these or other classes can be used to collide with one or more components of the inkjet ink. For example, if the collision agent is a cationic polymer, the collision agent may be one or more of the following: polyvinylpyridine, polyalkylaminoethylacrylate, polyalkylaminoethylmethacrylate, poly (vinylimidazole), polyethyleneimine, polybiguanide, polyguanidine, polyvinylamine, polyallylamine, polyacrylamide, polyquaternary amine, cationic polyurethane, amino cellulose and/or polysaccharide amine.

Alternatively, if the collision agent comprises a multivalent ion or ionic group, the collision agent may be provided by one or more of the following: polyvalent metal salts (e.g., aluminum nitrate, calcium chloride, and magnesium nitrate), EDTA salts, phosphonium halide phosphine salts, organic acids, and/or other monovalent salts.

Further, according to an exemplary embodiment, if the collision agent is an acid, the collision agent may be provided by one or more of the following: succinic acid, glycolic acid, citric acid, nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, polyacrylic acid, acetic acid, malonic acid, maleic acid, ascorbic acid, glutaric acid, fumaric acid, tartaric acid, lactic acid, nitrous acid, boric acid, carbonic acid, carboxylic acids such as formic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, fluoroacetic acid, trimethylacetic acid, methoxyacetic acid, thioglycolic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, rinolic acid, rinoleic acid, cyclohexanecarboxylic acid, phenylacetic acid, benzoic acid, o-toluic acid, m-toluic acid, p-chlorobenzoic acid, o-bromobenzoic acid, m-bromobenzoic acid, p-bromobenzoic acid, o-nitrobenzoic acid, m-nitrobenzoic acid, p-nitrobenzoic acid, oxalic acid, adipic acid, phthalic acid, m-phthalic acid, Terephthalic acid, salicylic acid, p-hydroxybenzoic acid, anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, benzenesulfonic acid, methylbenzenesulfonic acid, ethylbenzene sulfonic acid, dodecylbenzenesulfonic acid, 5-sulfosalicylic acid, 1-sulfonaphthalene, hexylsulfonic acid, octylsulfonic acid, dodecylsulfonic acid, amino acids such as glycine, alanine, valine, alpha-aminobutyric acid, alpha-alanine, taurine, serine, alpha-amino-n-hexanoic acid, leucine, norleucine and/or phenylalanine.

When the above-described anionic ink system is used in combination with a cationic fixer fluid, the level of resistance to highlighter smear and wet smudge on office paper is comparable to the typical level of resistance of similar images printed using conventional laser printing processes. Specifically, as described in the examples below, the above described anionic ink system and cationic fixer fluid provide wet set-off and highlighter set-off of less than 60mOD for office paper and less than 30mOD for coated office paper. Furthermore, when used with black pigments, the optical densities achieved are quite high, in the range of 1.30-1.90. The exemplary ink formulations of the present invention also provide good nozzle conditions over a wide frequency range and remain stable during storage.

Examples

The following examples illustrate the best presently known system and method embodiments. It is to be understood, however, that the following is only exemplary or illustrative of the application of the principles of the present system and method. Numerous modifications and alternative compositions, methods, and systems may be devised by those skilled in the art without departing from the spirit and scope of the present system and method. It is intended that the appended claims cover such modifications and arrangements. Thus, while the present system and method has been described above with particularity, the following examples provide further detail in connection with what are presently deemed to be the most practical and preferred embodiments of the present system and method.

Various inkjet ink formulations in accordance with the systems and methods of the present invention and more traditional control inks were prepared using the components and ranges shown in table 1. The components of each of the five formulations were mixed to form an ink jettable ink:

TABLE 1

Components	Formulation A	Formulation B	Formulation C	Formulation D	Formulation E	Formulation F
							Kabot 200 pigment	3.0	3.0	0.0	0.0	0.0	3.0
Pigment of polymer attached by cabot	0.0	0.0	3.0	3.0	3.0	0.0
							Acrylic latex A	3.0	0.0	0.0	0.0	0.0	0.0
Acrylic latex B	0.0	3.0	0.0	0.0	0.0	0.0
							Acrylic latex C	0.0	0.0	3.0	0.0	0.0	0.0
Acrylic latex D	0.0	0.0	0.0	3.0	3.0	0.0
							Joncryl 586 resin	0.6	0.6	0.6	0.0	0.0	1.8
Avecia PU resin	0.0	0.0	0.0	0.4	0.0	0.0
							Zonyl FSO surfactant	0.03	0.03	0.03	0.03	0.03	0.03
2-pyrrolidone	5.0	5.0	5.0	5.0	5.0	7.0
							1, 2-hexanediol	5.0	5.0	5.0	5.0	5.0	4.0
LEG-1	3.0	3.0	3.0	3.0	3.0	0.0
							Water (W)	Balance of	Balance of	Balance of	Balance of	Balance of	Balance of

The above inkjet ink formulation was printed on a piece of standard office paper (cationic fixer fluid as underprint) and coated glossy paper without fixer. Note that formulation E is a latex control formulation, without resin. Formulation F was a non-latex control formulation and contained Joncryl 586 resin. The results of printing and the print quality thereafter are shown in table 2.

TABLE 2

As shown in Table 2, the results belonging to formulas A and B are representative of the same formula using various colorant/pigment/dye systems. Similarly, formulations C and D are representative results that would be achieved using various polymer-attached pigments of J586 or PU resin. The results for formulations E and F show the results that might be expected with conventional latex and non-latex formulations, respectively. As shown in table 2, all inks tested exhibited acceptable decap performance. However, formulations a-D generally exhibited enhanced set-off performance on both standard and glossy paper. In particular, when formulations a-D were printed on coated offset Gloss (offset Lustro Gloss) media, the (smear) resistance was increased by a factor of 2-10 compared to the more traditional control formulations.

The foregoing description illustrates and describes merely exemplary embodiments of the present system and method. They are not intended to be exhaustive or to limit the present system and method to any precise forms disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the present system and method be defined by the following claims.

Claims (8)

1. A smear resistant anionic ink jettable ink system comprising:

0.1-6% of a colorant;

1-40% of a solvent comprising a combination of 2-pyrrolidone and 1, 2-hexanediol;

0.3-10% of latex adhesive, the granularity of which is 100-300 nanometers, and the glass transition temperature of which is-20 to +100 ℃;

water; and

0.1-4% of hydrophobic styrene-acrylic resin with an acid value of 50-250 and a molecular weight of 1,000-60,000 or polyurethane resin with an acid value of 40-200 and a molecular weight of 3,000-400,000.

2. The ink system of claim 1, wherein the colorant comprises a self-dispersed pigment.

3. The ink system as recited in claim 1, wherein the polyurethane resin comprises one of an Avecia polyurethane resin, an Alberdingk-Boley polyurethane resin, a basf polyurethane resin, or a Crompton polyurethane resin.

4. The ink system of claim 1, wherein the colorant comprises one of a dye, a pigment, or a pigment/dye mixture.

5. The ink system of claim 1, further comprising a cationic fixer fluid used in conjunction with the ink, the cationic fixer fluid including a crashing agent.

6. A method of printing an ink-jet image having high smear resistance, comprising:

selectively ink-jet printing an anionic ink-jet ink on a desired substrate;

fixing the anionic inkjet ink on the desired substrate with a cationic fixer fluid;

the anionic ink-jettable ink comprises 0.1 to 6% of a colorant; 1-40% of a solvent comprising a combination of 2-pyrrolidone and 1, 2-hexanediol; 0.3-10% of latex adhesive, the granularity of which is 100-300 nanometers, and the glass transition temperature of which is-20 to +100 ℃; water; and 0.1-4% of a hydrophobic styrene-acrylic resin having an acid value of 50-250 and a molecular weight of 1,000-60,000 or a polyurethane resin having an acid value of 40-200 and a molecular weight of 3,000-400,000.

7. The method of claim 6, wherein fixing the anionic inkjet ink to the desired substrate with a cationic fixing agent comprises overprinting the desired substrate with the cationic fixing agent.

8. The method of claim 6, wherein fixing the anionic inkjet ink to the desired substrate with a cationic fixing agent comprises underprinting the desired substrate with the cationic fixing agent.