KR20170098243A - Inks - Google Patents

Abstract

An ink comprising: (a) from 0.5 to 5 parts of a self dispersible pigment; (b) 2 to 8 parts of a styrene acrylate latex binder and / or a styrene butadiene latex binder; (c) 0.5 to 5 parts of a polyurethane latex binder; (d) 0 to 5 parts of a glycol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol or triethylene glycol; (e) 1 to 10 parts of 2-pyrrolidone; (f) 1 to 15 parts of glycerol; (g) 0.1 to 3 parts of an acetylene surfactant; (h) 0.001 to 5 parts of biocidal agent; (i) 0 to 10 parts of viscosity modifier; And (j) The remainder of the water to make 100 parts. Further, the ink-jet printing method. Inkjet ink containers, printed jars and inkjet printers.

Description

Inks {Inks}

The present invention relates to an ink, an inkjet printing process, an inkjet ink container, an ink set, and an inkjet printer.

Ink-jet printing is a non-impact printing technique in which an ink droplet is ejected through a fine nozzle onto a substrate without contacting the nozzle with the substrate. There are basically three types of inkjet printing:

i) Continuous inkjet printing uses a pressurized ink source that produces a continuous flow of ink droplets from the nozzles. The ink droplets are sent from the nozzles at a nominally constant distance thermally or electrostatically. Successfully deflected droplets are recycled through the gutter to the ink reservoir.

ii) Drop-on-demand inkjet printing is where the ink is stored in the cartridge and ejected from the printhead nozzles using a pressurization actuator (typically thermal or piezoelectric). For drop-on-demand printing, only the droplets required for printing are generated.

iii) Recycled ink-jet printing requires that the ink be continuously recirculated in the printhead and only droplets necessary for printing (such as drop-on-demand printing) are drawn into the nozzles.

Each of these types of inkjet printing presents a unique problem. Thus, during continuous inkjet printing, during flight times (i.e., the time between nozzle ejection and gutter recirculation) of the droplets that are ejected from the nozzles or that do not produce printed images, and excess air (when the unused droplets are recirculated, To prevent evaporation of the solvent from the ventilation process.

In drop-on-demand printing, the ink can be stored in the cartridge for a long period of time, where the ink can deteriorate to form a precipitate, which can block the fine nozzles in the printhead during use. This problem is particularly acute in pigment inks where suspended pigment particles can be precipitated.

Recycled inkjet printing avoids these problems. Since the ink circulates continuously, the chance of pigment settling is reduced and the evaporation of the solvent is minimized since the ink is removed by the nozzle only as required to form the image.

Recycled inkjet printers have found particular usefulness in industry. Industrial inkjet printers are required to operate at high speeds. Optimally, printheads for industrial inkjet printers will have a high number of nozzles arranged at a high density, thus allowing for high productivity single-pass printing, which has acceptable print resolution.

Much is required of ink formulations for all types of inkjet printing. It is particularly difficult to formulate inks that can operate in these high speed one-pass printheads. To enable such a printer to operate at such a high speed, the ink used should exhibit less bubbling and excellent droplet formation.

Therefore,

(i) without causing nozzle blockage in the recycle head;

(ii) is more volatile than standard inkjet inks to enable fast drying (which is essential in industrial processes because it allows high production rates with low energy consumption (i. e., low temperature printing));

(iii) provide high quality images of high durability comparable to flexographic printing by incorporating carefully selected latex and optimizing the ink delivery design;

(iv) sufficiently stable and robust to be used in continuous industrial environments;

(v) does not cause foaming;

(vi) does not cause face-plate wetting of the printhead.

The wetting capability of the liquid is a function of the surface tension of the liquid relative to the surface energy of the solid surface. Thus, when the liquid molecules have molecules on the solid surface and a larger attractive force than the attraction between them (the adhesion is stronger than the cohesive force), surface wetting occurs. However, if the molecules in the liquid are attracted more strongly than molecules on the solid surface (cohesion is stronger than adhesion), the liquid becomes bead-up and does not wet the surface. The degree of wetting of a liquid on a specific surface can be determined by measuring the contact angle of the liquid droplet located on the surface. If the contact angle is less than 90 °, the liquid is said to wet the surface. The lower the contact angle, the greater the degree of wetting.

It is a problem to design a volatile ink containing a low film forming temperature latex (as required in (ii) and (iii)) that does not wet the face plate of the print head without causing foaming.

Thus, according to one aspect of the present invention, there is provided an ink comprising:

(a) 0.5 to 5 parts of a self-dispersible pigment;

(b) 2 to 8 parts of a styrene acrylate latex binder and / or a styrene butadiene latex binder;

(c) 0.5 to 5 parts of a polyurethane latex binder;

(d) 0 to 5 parts of a glycol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol or triethylene glycol;

(e) 1 to 10 parts of 2-pyrrolidone;

(f) 1 to 15 parts of glycerol;

(g) 0.1 to 3 parts of an acetylene surfactant;

(h) 0.001 to 5 parts of biocidal agent;

(i) 0 to 10 parts of viscosity modifier; And

(j) The remainder of the water to make 100 parts.

All parts and percentages herein are by weight (unless otherwise stated) and percent by weight.

A "self dispersible pigment" is a pigment preparation which, when added to a liquid medium, is free, fast and continuously dispersible. If the pigment has a charged group on its surface (either directly or through a conjugated polymer dispersant), it preferably has a counterion.

Preferably, the self-dispersible pigments are derived from any kind of pigment described in the Color Index Third Edition (1971) and later in the edition entitled " Pigments "

Examples of suitable organic pigments are azo pigments including azo (including disazo and condensed azo), thioindigo, indanthrone, isoindanthrone, anthanthrone, anthraquinone, isodibenzanthrone, triphendioxane, quinacridone, Phthalocyanine series, especially copper phthalocyanine and its nucleus halogenated derivatives, as well as those derived from acid dye lake, base dye lake and mordant dye lake. Carbon black is often considered to be an inorganic pigment, but its dispersion properties behave similarly to organic pigments and are also suitable. Preferred organic pigments are phthalocyanines, especially copper phthalocyanine pigments, azo pigments, indanthrone, anthanthrone, quinacridone and carbon black pigments.

Preferably, the pigment is a yellow, cyan, magenta or black pigment. The pigment may be a single species or a mixture comprising two or more species (for example, a mixture comprising two or more different pigments). That is, two or more different pigment solids can be used in the process of the present invention.

More preferably, the self-dispersible pigment is selected from the group consisting of carbon black; Pigment Blue 15: 3; Pigment Blue 60; Pigment Yellow 74; Pigment Yellow 155; Pigment Red 254 and Pigment Red 122.

The pigments in the self-dispersing pigments may be dispersed by any means known in the art. This may include coating the surface of the pigment with a suitable dispersing agent or a mixture thereof. The dispersing agent may be anionic, cationic or nonionic and may include random, block or comb polymers. Suitable dispersing agents include, but are not limited to, poly (meth) acrylates, polyurethanes, polyesters and polyethers.

Other preferred self-dispersible pigments can be prepared by chemically modifying the surface of the pigment. This is particularly desirable in the case of carbon black, where the pigment surface is oxidized so that the carbon black is water-dispersible. Suitable oxidizing agents include air, hydrogen peroxide, hypochlorite, nitric acid, nitrogen dioxide, ozone and persulfate.

Thus, in one preferred embodiment of the present invention, the self-dispersible pigment is a surface-oxidized carbon black.

The organic pigments may also have charged groups introduced on their surface using reagents characterized for a particular type / type of pigment or using more general reactions such as sulfonation.

Alternatively, the self-dispersible pigment may have a charged group or have a polymeric dispersant chemically covalently attached to its surface.

Thus, for example, carbon black can react with a diazonium salt. This allows the introduction of certain charged groups on the surface of the carbon black. A phenyl spacer group is commonly used with a charged group / dispersant group to be attached to the phenyl. Examples of such charged groups are sulfonate, carboxyl, phosphonate and non-phosphonate. It is also possible to introduce various polymeric dispersants onto the surface of the carbon black using diazonium chemistry.

In addition, certain organic pigments may have charged groups and polymeric dispersants introduced via diazonium chemistry on their surface. The dispersant attached to the surface of the self-dispersing pigment may be of any type known to those skilled in the art. Dispersants may be designed for use with a particular pigment or may be generally applicable.

In a preferred embodiment of the invention, the self-dispersible pigment is a pigment having a charged group or polymer dispersant covalently attached to the surface of the pigment by means of a diazonium compound.

One preferred form of dispersant is a diblock copolymer A-B or a triblock copolymer A-B-A, wherein block B has affinity for the pigment and block A contributes to colloidal stabilization. In the case of an organic pigment, it is possible to synthesize a specific pigment containing such a dispersant rather than attaching the dispersant to the pigment in the post-synthesis step.

The self-dispersing pigment of component (a) preferably comprises a dispersing agent bridged around the pigment.

In a particularly preferred embodiment, the self-dispersing pigment of component (a) comprises a carboxy-functional dispersant cross-linked by a crosslinking agent around the pigment core, wherein the crosslinking agent is selected from oxetane, carbodiimide, hydrazide, At least two groups selected from oxazoline, aziridine, isocyanate, N-methylol, ketene imine, isocyanurate and epoxy groups, especially two or more epoxy groups.

Prior to crosslinking with the crosslinking agent, the dispersant preferably has an acid value of at least 125 mg KOH / g.

Preferably, the dispersant has at least one oligomer dispersing group.

In order to provide water-dispersibility, polymer-encapsulated pigment particles preferably have a carboxyl group (i.e., all of the carboxyl groups in the dispersant are crosslinked to form pigment particles encapsulated in a polymer no).

The pigment particles encapsulated with the polymer may be prepared by crosslinking some of the carboxyl groups in the carboxy-functional dispersant, preferably in the presence of a pigment and a crosslinking agent, preferably at a temperature of less than 100 < 0 > C and / or at a pH of at least 6. [ Such crosslinking is generally carried out in an aqueous medium, for example, a mixture comprising water and an organic solvent. Suitable mixtures, including water and organic solvents, are described above in connection with inks.

Preferably, the pigment particles encapsulated with the polymer have a Z-average particle size of less than 500 nm, more preferably from 10 to 400 nm, especially from 15 to 300 nm.

The Z-average particle size can be measured by any means, but the preferred method is to use a photon correlation spectroscopy apparatus commercially available from Malvern (R) or Coulter (R).

Suitable methods of preparing the pigment particles encapsulated with the polymer are described in WO2006 / 064193 and WO2010 / 038071. Essentially, after a dispersant with a carboxyl group is adsorbed to the pigment, some (but not all) of the carboxyl groups are crosslinked to provide a pigment dispersion, which is permanently entrapped in the crosslinked dispersant. These particles are commercially available from FUJIFILM Imaging Colorants Limited.

Preferably, the carboxy-functional dispersant comprises benzyl methacrylate.

Preferred carboxy-functional dispersants include at least one hydrophobic ethylenically unsaturated monomer (preferably at least one-half by weight benzyl methacrylate); At least one hydrophilic ethylenically unsaturated monomer having at least one carboxyl group; And optionally some hydrophilic or non-hydrophilic ethylenically unsaturated monomers having at least one hydrophilic nonionic group.

A particularly preferred carboxy-functional dispersant is a copolymer comprising:

(i) from 75 to 97 parts of at least one hydrophobic ethylenically unsaturated monomer comprising at least 50 parts of benzyl methacrylate;

(ii) 3 to 25 parts of at least one hydrophilic ethylenically unsaturated monomer having at least one carboxyl group; And

(iii) 0 to 1 part of a hydrophilic ethylenically unsaturated monomer having at least one hydrophilic nonionic group.

Here, parts are parts by weight.

Typically, the negative sum of (i), (ii) and (iii) is 100 or less.

In component (i) it is preferred that the hydrophobic ethylenically unsaturated monomer is only benzyl methacrylate.

More preferably, the carboxy-functional dispersant is a copolymer comprising:

(i) 80 to 93 parts of at least one hydrophobic ethylenically unsaturated monomer comprising at least 50 parts of benzyl methacrylate;

(ii) 7 to 20 parts of at least one hydrophilic ethylenically unsaturated monomer having at least one carboxyl group; And

(iii) 0 to 1 part of a hydrophilic ethylenic unsaturated monomer having a hydrophilic nonionic group;

Here, the parts are parts by weight.

Typically, the negative sum of (i), (ii) and (iii) is 100 or less.

Preferably, the hydrophobic monomer does not have an ionic or nonionic hydrophilic group. For example, there is preferably no water-dispersible group.

Preferably, the hydrophobic ethylenically unsaturated monomer has a calculated log P value of at least 1, more preferably from 1 to 6, in particular from 2 to 6.

A review report by Mannhold, R and Dross, K. (Quant. Struct-Act Relat. 15, 403-409, 1996) describes how to calculate the log P value.

Preferred hydrophobic ethylenically unsaturated monomers include styrene-based monomers (e.g., styrene and alpha-methyl styrene), aromatic (meth) acrylate (in particular, benzyl (meth) acrylate), C _{1 - 30} hydrocarbyl (meth) acrylate , Butadiene, (meth) acrylates containing a poly (C _3-4 ) alkylene oxide group, (meth) acrylates and vinylnaphthalenes containing an alkylsiloxane or a fluorinated alkyl group.

Preferably, the dispersant comprises recurring units derived from copolymerization of component (i) of 75 to 97, more preferably 77 to 97, especially 80 to 93, most particularly 82 to 91 parts by weight.

Dispersants comprising at least 50 benzyl (meth) acrylate monomer repeat units can provide a pigment dispersion encapsulated with a polymer having excellent stability and good optical density.

Preferably, component (i) comprises at least 60 parts by weight, more preferably at least 70 parts by weight, especially at least 75 parts by weight benzyl (meth) acrylate. The remainder required to obtain the entire desired amount of hydrophobic monomer may be provided by one or more of any of the above hydrophobic monomers other than benzyl (meth) acrylate. Preferably, benzyl (meth) acrylate is benzyl methacrylate (rather than benzyl acrylate).

In a preferred embodiment, component (i) comprises only benzyl (meth) acrylate, more preferably only benzyl methacrylate.

Preferably, the monomers of component (ii) have a weight average molecular weight of less than 1, more preferably from 0.99 to -2, especially from 0.99 to 0, Most particularly from 0.99 to 0.5.

Preferred hydrophilic ethylenically unsaturated monomers having at least one carboxyl group in component (ii) include betacarboxyl ethyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, more preferably acrylic acid, especially methacrylic acid. Preferably, these ethylenically unsaturated monomers provide a unique ionic group to the dispersant when polymerized.

In a preferred embodiment, component (ii) is either methacrylic acid or methacrylic acid.

Preferably, the dispersing agent comprises repeating units derived from copolymerization of 3 to 25 parts by weight, more preferably 3 to 23 parts by weight, especially 7 to 20 parts by weight, and most particularly 9 to 18 parts by weight of component (ii) . This is especially true when component (ii) comprises methacrylic acid or, more preferably, is methacrylic acid.

For the purposes of the present invention, monomers having both ionic and nonionic hydrophilic groups are considered to belong to component (iii). Thus, all ethylenically unsaturated monomers in component (ii) are free of hydrophilic nonionic groups.

Preferably, the monomers in component (iii) have a calculated log P value of less than 1, more preferably from 0.99 to -2.

Preferably, component (iii) is less than 1 part, more preferably less than 0.5 part, especially less than 0.1 part, and most particularly 0 part (i.e., absent). In this manner, the dispersant does not contain repeating units derived from a hydrophilic monomer having at least one hydrophilic nonionic group.

Examples of hydrophilic nonionic groups include polyethyleneoxy, polyacrylamide, polyvinylpyrrolidone, hydroxy-functional cellulose and polyvinyl alcohol. The most common ethylenically unsaturated monomer having a hydrophilic nonionic group is polyethyleneoxy (meth) acrylate.

In one embodiment of the embodiment wherein recurring units derived from component (iii) are present in the dispersant (e.g., 1 part by weight of component (iii)) the amount of component (iii) is from the preferred amount of component (i) Subtract. In this way, all amounts of components (i), (ii) and (iii) are still less than 100 in total. Thus, for embodiments in which component (iii) is present in an amount of 1 part by weight, the preferred amount of component (i) mentioned above is in the range of 74 to 96 (75-1 to 97-1) parts by weight, more preferably 76 to 96 (I) of from 80 to 93-1 parts by weight, particularly from 79 to 92 parts by weight, and most particularly from 81 to 90 parts by weight (82-1 to 91-1 parts by weight) will be. In another embodiment, it is also possible to subtract the amount of component (iii) from the preferred amount of component (ii), in which case the sum of the amounts of components (i), (ii) and (iii) .

The main function of the carboxylic acid group (s) in the dispersant is to crosslink with the crosslinking agent, and then to provide the pigment particles encapsulated with the polymer with dispersing ability in an aqueous ink medium. When the carboxylic acid group (s) is the only group that stabilizes the pigment particles encapsulated in the polymer in the aqueous medium, the carboxylic acid group of the molar excess relative to the carboxy-reactive group (e.g., epoxy group) , Which is to ensure that unreacted carboxylic acid groups remain after the crosslinking reaction is completed. In one embodiment, the ratio of the number of moles of carboxylic acid groups to the number of moles of carboxy-reactive groups (e.g., epoxy groups) in the crosslinking agent is preferably from 10: 1 to 1.1: 1, more preferably from 5: : 1, particularly preferably from 3: 1 to 1.1: 1.

The dispersant may optionally have other stabilizers. As well as the choice of stabilizer, the amount of these groups will vary greatly depending on the nature of the aqueous medium.

In embodiments in which the crosslinking agent has at least one oligomer dispersing group, the dispersing agent has an acid value of at least 125 mg KOH / g.

The acid value of the dispersant before crosslinking with the crosslinking agent is preferably 130 to 320, more preferably 135 to 250 mg KOH / g. The present inventors have found that dispersants having such acid values not only provide excellent stability in aqueous liquid inks, but also provide pigment particles encapsulated with polymers having sufficient carboxyl groups for subsequent crosslinking with the crosslinking agent. Preferably, the dispersant (prior to crosslinking) has a number average molecular weight of 500 to 100,000, more preferably 1,000 to 50,000, especially 1,000 to 35,000. The molecular weight can be measured by gel permeation chromatography.

The dispersant need not be completely dissolved in the liquid medium used to prepare the pigment particles encapsulated with the polymer. That is, it need not be a completely transparent, non-scattering solution. The dispersant may aggregate with micelles like a surfactant to provide a slightly turbid solution in the liquid medium. The dispersing agent may be one in which some proportion of the dispersing agent tends to form a colloidal or micelle phase. The dispersant preferably produces a uniform and stable dispersion in a liquid medium used to prepare the pigment particles encapsulated with a polymer that is not precipitated or separated on standing.

The dispersant is preferably substantially soluble in the liquid medium used to prepare the pigment particles encapsulated in the polymer, which provides a clear or turbid solution.

While preferred random polymer dispersants tend to provide a clear composition, less preferred polymeric dispersants having two or more segments tend to provide a cloudy composition as described above in a liquid medium.

Typically, the dispersant is adsorbed onto the pigment prior to crosslinking to form a relatively stable pigment particle dispersion. This dispersion is then crosslinked using a crosslinking agent to form pigment particles encapsulated in the polymer. This pre-adsorption and pre-stabilization distinguishes the present invention from the coacervation approach in particular, whereby the polymer or prepolymer (but not the dispersant) is mixed with the particulate solid, the liquid medium and the cross-linking agent, Or crosslinked polymeric precipitate is formed on the particulate solid.

In embodiments where the dispersant has an acid value of at least 125 mg KOH / g, the crosslinking agent may not have an oligomer dispersing group, but preferably the crosslinking agent has at least one oligomer dispersing group.

Crosslinking agents having one or more oligomeric dispersing groups increase the stability of the pigment particles encapsulated in the polymer in the ink.

Preferably, the oligomer dispersing group is or comprises a polyalkylene oxide, more preferably a poly C _{2 -4} -alkylene oxide, especially polyethylene oxide. The polyalkylene oxide groups provide steric stabilization which improves the stability of the resulting encapsulated particulate solids.

Preferably, the polyalkylene oxide contains 3 to 200, more preferably 5 to 50, alkylene oxides, especially 5 to 20 alkylene oxide repeat units.

Preferably, the crosslinking agent has at least two epoxy groups.

Preferred crosslinking agents having two epoxy groups and free of oligomer dispersing groups are ethylene glycol diglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, hydrogenated bisphenol A diglycidyl ether and polybutadiene diglycidyl ether.

Preferred crosslinking agents having two epoxy groups and having at least one oligomer dispersing group are diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether .

Preferred crosslinking agents having three or more epoxy groups and no oligomer dispersing group are sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether Diallyl ether and trimethylol propane polyglycidyl ether.

In one embodiment, the epoxy cross-linker does not have an oligomer dispersing group.

Examples of the oxetane crosslinking agent include 1,4-bis [(3-ethyl-3-oxetanylmethoxymethyl)] benzene, 4,4'-bis [(3-ethyl-3oxetanyl) methoxy] Bis [(3-ethyl-3-oxetanyl) -methoxy] benzene, 4,4-bis (3-ethyl-3-oxetanyl) methoxy] biphenyl and 3,3 ', 5,5'-tetramethyl- [4,4'- Lt; / RTI > biphenyl.

Examples of carbodiimide crosslinking agents include crosslinking agent CX-300 from DSM NeoResin. Carboymide crosslinking agents having excellent solubility and dispersibility in water can also be prepared as described in Synthesis Examples 1 to 93 of U.S. Patent No. 6,124,398.

Examples of carbodiimide crosslinking agents include crosslinking agent CX-300 from DSM NeoResin. Carboymide crosslinking agents having excellent solubility and dispersibility in water can also be prepared as described in Synthesis Examples 1 to 93 of U.S. Patent No. 6,124,398.

Examples of isocyanate crosslinking agents include isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, methylenediphenyl diisocyanate, methylenedicyclohexyl diisocyanate, 2-methyl-1,5-pentane diisocyanate, 2,2,4 -Trimethyl-1,6-hexane diisocyanate and 1,12-dodecane diisocyanate, 1,11-diisocyanatocondecane, 1,12-diisocyanatododecane, 2,2,4- and 2,4 , 4-trimethyl-1,6-diisocyanatohexane, 1,3-diisocyanatocyclobutane, 4,4'-bis- (isocyanatocyclohexyl) -methane, hexamethylene diisocyanate, 1 (Isocyanatomethyl) -cyclobutane, 1,3- and 1,4-bis- (isocyanatomethyl) cyclohexane, hexahydro-2,4- and / or -2, 6-diisocyanatoluene, 1-isocyanato-2-isocyanatomethylcyclopentane, 1-isocyanato-3-iso Cyanate methyl-3,5,5-trimethyl-cyclohexane, 2,4'-dicyclohexylmethane diisocyanate and 1-isocyanato-4 (3) -isocyanato methyl- Hexane, tetramethyl-1,3, - and / or -1,4-xylene diisocyanate, 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / Toluene diisocyanate, 2,4- and / or 4,4'-diphenyl-methane diisocyanate, 1,5-diisocyanatonaphthalene and p-xylylene diisocyanate. Suitable diisocyanates also include those containing a modification group such as biuret, uretdione, isocyanurate, allophanate and / or carbodiimide groups, as long as they contain two or more isocyanate groups . In the case of isocyanates, in some cases water is allowed in blocked isocyanates, but preferably the liquid medium is non-aqueous.

In a preferred embodiment, the polyisocyanate crosslinker contains three isocyanate groups. A convenient source of triisocyanate functional compounds is known as isocyanurate derivatives of diisocyanates. Isocyanurate derivatives of diisocyanates can be prepared by reacting a diisocyanate with a suitable trimerization catalyst. An isocyanurate derivative containing an isocyanurate core having a pendant organic chain terminated with three isocyanate groups is prepared. Some isocyanurate derivatives of diisocyanates are commercially available. In one preferred embodiment, the isocyanurate used is an isocyanurate of isophorone diisocyanate. In another preferred embodiment, isocyanurate of hexamethylene diisocyanate is used.

Examples of N-methylol cross-linkers include dimethoxydihydroxyethylene urea; N, N-dimethylol ethyl carbamate; Tetramethylol acetylenediurea; Dimethylolurone; Dimethylol ethyleneurea; Dimethylol propylene urea; Dimethylol adipic amide; And mixtures comprising two or more of the foregoing.

Examples of ketene imine crosslinkers include compounds of the formula Ph ₂ C = C = NC ₆ H ₄ -N = C = CPh ₂ , wherein each Ph is independently an optionally substituted phenyl group.

Examples of hydrazide crosslinking agents are malonic acid dihydrazide, ethyl malonic acid dihydrazide, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, isophthalic dihydrazide , Oxyl dihydrides and pimelic dihydrazides.

Very highly reactive oxazoline crosslinkers commercially available are, for example, available from Nippon Shokubai under the trade name Epocross®. They may be of the emulsion type (e.g. Epocross K-2000 series, e.g. K-2010E, K-2020E and K-2030E) and aqueous type (e. G. Epocross WS series, -300, WS-500 and WS-700).

Examples of aziridine crosslinking agents include ethyleneimine polyaziridines (e.g., PZ-28 and PZ-33 available from PolyAziridine LLC, Medford, NJ); XC-103 trifunctional aziridine, XC-105 polyfunctional aziridine and Crosslinker XC-113 (available from Shanghai Zealchem Co., Ltd., China); Multifunctional aziridine liquid crosslinking agent SaC-100 (available from Shanghai UN Chemical Co., Ltd, China); Aziridine crosslinking agents disclosed in WO 2009/120420; NeoCryl 占 CX-100 (available from DSM NeoResin); Xama® polyfunctional aziridine (available from Lubrizol); (Beta-aziridino) propionate, pentaerythrityl tetra (beta-aziridino) propionate, neopentyl glycol di (beta-aziridino) propionate, glyceryl tris Dino) propionate, 4,4'-isopropylidenediphenol di (beta-aziridino) propionate, 4,4'-methylenediphenol di (beta-aziridino); And mixtures comprising at least two of the foregoing.

Particularly preferred crosslinking agents are polyethylene glycol diglycidyl ether and / or trimethylolpropane polyglycidyl ether (available, for example, from Nagase Chemtex, having an average molecular weight of 526 and available from Aldrich) Denacol® EX-321 with an epoxy weight of 140).

Preferably, component (a) is present in the range of 0.75 to 4 parts, more preferably 1 to 3 parts.

The ink may comprise one or more styrene acrylic latex binders and / or styrene butadiene latex binders (component (b)). The latex binders may differ in properties such as particle size, glass transition temperature or molecular weight.

However, the styrene acrylate latex binder and / or styrene butadiene latex binder is preferably a styrene acrylate latex binder or a styrene butadiene latex binder. More preferably, component (b) is a styrene acrylic latex binder.

Preferably, the styrene acrylic latex binder has a Tg in the range of -30 캜 to 50 캜, more preferably in the range of 0 캜 to 40 캜, and particularly in the range of 10 캜 to 30 캜.

Preferably, the styrene butadiene latex binder has a Tg in the range of from 0 占 폚 to 120 占 폚, more preferably from 10 占 폚 to 110 占 폚, and particularly in the range of from 50 占 폚 to 90 占 폚.

The Tg is measured by Differential Scanning Calorimetry of the dried latex. The Tg is taken as an intermediate value of the reheating differential scanning calorimetry scan (i.e., after the initial heating and cooling).

The styrene acrylic latex preferably has an acid value in the range of 5 to 100 mgKOH / g, more preferably 30 to 70 mgKOH / g.

Preferably, the styrene acrylate latex binder and / or styrene butadiene latex binder is prepared by emulsion polymerization.

The molecular weight of the styrene acrylic latex binder and the styrene butadiene latex binder can be adjusted by methods known in the art, for example, by the use of a chain transfer agent (e.g., mercaptan) and / By controlling the concentration and / or by the heating time. Preferably, the styrene acrylic latex binder and the styrene butadiene latex binder have a molecular weight of greater than 20,000 daltons, more preferably greater than 100,000 daltons. The molecular weight of the styrene acrylate latex binder and the styrene butadiene latex binder is particularly preferably more than 200,000 to more than 500,000 daltons.

The styrene acrylic latex binder and the styrene butadiene latex binder may preferably be monomodal with an average particle size of less than 1000 nm, more preferably less than 200 nm and especially less than 150 nm. Preferably, the average particle size of the styrene acrylic latex binder and the styrene butadiene latex binder is at least 20 nm, more preferably at least 50 nm. Thus, the styrene acrylate latex binder and the styrene butadiene latex binder may have an average particle size preferably in the range of 20 to 200 nm, more preferably in the range of 50 to 150 nm. The average particle size of the styrene acrylic latex binder and the styrene butadiene latex binder can be measured using photon correlation spectroscopy.

The styrene acrylic latex binder and the styrene butadiene latex binder may also exhibit a bimodal particle size distribution. This may be accomplished by mixing two or more latexes of different particle sizes or by directly producing a bimodal distribution by, for example, two-step polymerization. When a bimodal particle size distribution is used, it is preferred that the lower particle size peak is in the 20-80 nm range and the higher particle size peak is in the 100-500 nm range. More preferably, the ratio of the two particle sizes is at least 2, more preferably at least 3, and most preferably at least 5.

The molecular weight of the styrene acrylic latex binder and the styrene butadiene latex binder can be measured by gel permeation chromatography on a polystyrene standard using an Agilent HP 1100 apparatus with a PL Mixed Gel C column with THF as the eluent.

Once the styrene acrylic latex binder and the styrene butadiene latex binder are formed, they are screened and over-exposed prior to use, for example, through a filter having an average pore size of less than 3 mu m, preferably 0.3 to 2 mu m, particularly 0.5 to 1.5 mu m, Size particles are removed. The styrene acrylate latex binder and the styrene butadiene latex binder may be screened during or after the formation of the ink by mixing it with other components.

Commercially available styrene acrylate latex binders and styrene butadiene latex binders can be used in the inks according to the present invention.

Examples of commercially available styrene acrylic latex binders and styrene butadiene latex binders that can be used in the inks of the present invention are the Rovene® range supplied by Mallard Creek Polymer, in particular the styrene acrylic latexes of Rovene 6102, Rovene 6112 and Rovene 6103, Rovene 5499, and Rovene 4111.

Component (b) preferably ranges from 5 to 8 parts.

Component (c) is a polyurethane latex binder.

The polyurethane dispersions are conventionally prepared by:

(i) formation of a prepolymer by reaction of a polymeric diol (polyol) and optionally other components capable of reacting with an isocyanate group with a diisocyanate;

(ii) dispersion in water (optionally followed by chain extension of the prepolymer) by reaction with water and / or by reaction with a chain extender present as an aqueous phase.

The dispersion may be stabilized by monomers present in the polyurethane, for example, ionic groups or nonionic groups, or by added surfactants.

The Tg of the polyurethane latex binder can be controlled through the selection of the polyol, diisocyanate and chain extender. It is also possible to control the Tg of the polyurethane binder latex by mixing batches of latexes having different Tg's.

Preferably, the polyurethane latex binder has a Tg in the range of -30 캜 to 0 캜.

The weight average molecular weight of the polyurethane is preferably > 20,000, more preferably > 50,000, and most preferably > 100,000.

Preferably, the polyurethane latex binder has an average particle size of less than 1000 nm, more preferably less than 200 nm, in particular less than 150 nm. Preferably, the average particle size of the latex binder is at least 20 nm, more preferably at least 50 nm. Thus, the latex binder has an average particle size in the range of 20 to 200 nm, more preferably in the range of 50 to 150 nm. The average particle size of the latex binder can be measured using photon correlation spectroscopy.

Commercially available polyurethane latex binders include W835 / 177 and W835 / 397 from Incorez, Joncryl® U4190 from BASF and Sancure 2710 from Lubrizol.

Component (c) is preferably present in the range of 1 to 3 parts. The latex binder plays a key role in improved adhesion to the ink of the present invention when applied to low surface energy substrates and to durability of prints under wet and oily conditions.

The latex binders (b) and (c) play a key role in improved adhesion to the ink of the present invention when applied to low surface energy substrates and to durability of prints under wet and oily conditions.

Component (d) is preferably ethylene glycol or triethylene glycol.

Component (d) is preferably present in the range of 0.5 to 2.5 parts and more preferably in the range of 0.75 to 2.0 parts.

Component (e) is preferably present in the range of from 2.5 to 7.5 parts.

Component (f) is preferably present in the range of 2 to 7.5 parts.

Any acetylenic surfactant can be used as component (g). However, it has been found that when 2,4,7,9-tetramethyl-5-decyne-4,7-diol and its ethylene oxide condensate and 2,5,8,11-tetramethyl-6-dodecyne- And an ethylene oxide condensate thereof are preferable.

It is particularly preferred that the acetylene surfactant is 4,7,9-tetramethyl-5-decyne-4,7-diol or an ethylene oxide condensate thereof. It is particularly preferable that the acetylene surfactant is 4,7,9-tetramethyl-5-decyne-4,7-diol. Surfactants 2,4,7,9-Tetramethyl-5-decyne-4,7-diol and its ethylene oxide condensates are available from Air Products in the surfactant Surfynol® range.

The preferred surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol is commercially available from Air Products as Surfynol® 440 or the ethoxylated analogue Surfynol® 465.

Mixtures containing various surfactants may be used.

The component (g) is preferably present in the composition in a range of 0.001 to 2.5 parts, more preferably 0.01 to 1.5 parts, especially 0.05 to 1.0 part, and more particularly 0.1 to 0.5 part.

The surfactant is a major component in the ink of the present invention. The correct selection of both the surfactant and its concentration, especially in the ink, is essential for effectively spraying the ink without wetting the face of the printhead.

It is essential that the surfactant does not foil the ink.

Further, it is preferable that the ink is designed not to wet the face plate of the print head that has not been treated with the "non-wetting coating ". Such a face plate may exhibit a contact angle of less than 90 DEG or less than 80 DEG with water. A face plate specifically designed to be non-wetted may have a contact angle greater than 90 °, sometimes greater than 95 °, and sometimes even greater than 100 °.

In order to achieve this property, it is desirable that the ink exhibit a dynamic surface tension range, i.e. its surface tension depends on the surface age. The surface tension of the newly generated surface is high but decreases due to surfactant or other surface active species moving to the surface. The dynamic surface tension range can be determined by measurement in a bubble tensiometer. This measures the surface tension as a function of surface life or bubble frequency. The surface tension measured at 5 ms (γ (5)) is> 35 dynes / cm and the surface tension measured at 1,000 ms (γ (1000)) is in the range of 20 to 40 dynes / cm, ) >? (1000)). Alternatively, the equilibrium surface tension of the ink may be compared to that of an equivalent prepared without the inclusion of the surfactant (s). The equilibrium surface tension without surfactant is preferably at least 10 dynes / cm higher than when the surfactant (s) are present.

In the case of component (h), any biocide stable (or a mixture of biocides) in the ink may be used. The biocide is a mixture of 1,2-benzisothiazolin-3-one from Lonza's Proxel® and Bioban® available as an active solution at 20% and DXN (2,6- Dimethyl-1,3-dioxan-4-yl acetate).

The viscosity modifier of component (i) is preferably selected from the group consisting of polyethers (e.g., polyethylene glycol and poly (ethylene oxide)), cellulosic polymers (such as hydroxyethylcellulose, hydroxypropylcellulose and carboxymethylcellulose ), Water-soluble polyesters, homopolymers of 2-ethyl-oxazoline, poly-2-ethyl-2-oxazoline), poly (vinyl alcohol) and poly (vinylpyrrolidone) do.

Component (i) is preferably poly (ethylene glycol) or poly (ethylene oxide). More preferably, component (h) is polyethylene glycol, especially polyethylene glycol 20,000.

Component (i) is preferably present in the composition in an amount of from 3 to 8 parts.

The ink preferably has a MFFT of less than 65 占 폚, especially less than 60 占 폚.

The MFFT is the lowest temperature at which components of the ink component coalesce to form a film, for example during ink drying.

MFFT measurement devices are commercially available, for example, the Minimum Film Forming Temperature Bar is available from Rhopoint Instrument ("MFFT Bar 90"). The MFFT Bar 90 includes a temperature bar with a nickel plated copper platen, with an electronically imposed temperature gradient. Ten sensors of equal spacing beneath the surface immediately measure the temperature along the bars. The desired temperature program is selected, allowing the instrument to reach thermal equilibrium. Using a cube applicator or a spreader, the tracks of the wet test ink can be applied. Once the ink has dried, the device shows MFFT. If, for some reason, the above-described commercially available equipment does not operate on the ink (e.g. due to low latex content and / or ink tint), a small amount of ink may be placed in the dish instead, The plate is heated for 24 hours at the desired evaluation temperature (e.g., 70 DEG C) and then rubbed with gloved fingers to assess whether the film is formed. If a film is formed, little or no ink will be applied to the fingers with gloves, but if the film is not formed, the fingers with the gloves will have significant inking or the dried ink will crack.

A preferred MFFT can be achieved by appropriate selection of a combination of polymer latex and organic solvent. If the MFFT of the ink is too high, the amount of coalescing solvent (coalescing solvent) to bring the ink MFFT to the desired range may be increased and / or polymer latex of lower Tg may be used. Thus, in the ink design step, it may be determined, depending on the desired MFFT, to include more or less cohesive solvent and higher or lower Tg polymer latex.

Typically, the ink will select the ink and substrate so that the substrate has a MFFT below the temperature at which the substrate is deformed, twisted, or melted. In this way, the ink can form a film on the substrate at a temperature that does not damage the substrate.

In a first preferred embodiment the viscosity of the ink at 32 DEG C is in the range of 10 to 14 mPa.s when measured at 150 rpm using BROOKFIELD SC4-18.

In a second preferred embodiment, the viscosity of the Ink 1 at 32 占 폚 is in the range of 4 to 8 mPa.s when measured at 150 rpm using Brookfield SC4-18.

In a first preferred embodiment, the ink has a viscosity of from 20 to 65 dynes / cm, more preferably from 20 to 50 dynes / cm, especially from 32 to 42 dynes / cm, more particularly from 20 to 65 dynes / And a surface tension of 34 to 38 dynes / cm.

In a second preferred embodiment, the ink has a surface tension of from 20 to 65 dynes / cm, more preferably from 20 to 50 dynes / cm, especially from 30 to 40 dynes / cm, as measured at 25 DEG C using a Kruss K100 tensiometer Respectively.

Preferably, the ink composition is filtered through a filter having an average pore size of less than 10 microns, more preferably less than 5 microns, and especially less than 1 micron.

Preferably, the ink has a pH in the range of 7.5 to 9.5. The pH can be controlled by a suitable buffer.

In addition to the above-mentioned ingredients, the ink composition may optionally comprise one or more ink additives. Preferred additives suitable for inkjet printing inks are anti-kogation agents, rheology medifiers, corrosion inhibitors and chelating agents. Preferably, the total amount of all such additives does not exceed 10 parts by weight. These additives are added to component (j) which is the water added to the ink and occupy a part of component (j).

In one preferred embodiment, the ink comprises:

(a ') 0.75 to 4 parts of a self-dispersible pigment;

(b ') 4 to 10 parts of a styrene acrylate latex binder;

(c ') 1 to 3 parts of a polyurethane latex binder;

(d ') 0.5 to 2.5 parts of ethylene glycol;

(e ') 2.5 to 7.5 parts of 2-pyrrolidone;

(f ') 2 to 7.5 parts of glycerol;

(g ') 0.05 to 1.0 part of 2,4,7,9-tetramethyl-5-decyne-4,7-diol;

(h ') 0.001 to 2 parts of biocidal agent;

(i ') 3 to 8 parts of viscosity modifier; And

(j ') The remainder of the water to make 100 parts.

In a second preferred embodiment, the ink of the present invention is deficient in glycol. That is, the component (d) is zero.

The present invention is of particular value in printing on non-absorbent and / or thermosensitive substrates, but can also be used for printing on absorbent and / or non-thermosensitive substrates. For these substrates, the inks and methods of the present invention provide the advantage of providing prints with excellent rub-fastness properties at temperatures lower than those used in conventional processes, thereby reducing manufacturing costs do.

Examples of non-absorbent substrates include, but are not limited to, polyester, polyurethane, bakelite, polyvinyl chloride, nylon, polymethylmethacrylate, polyethylene terephthalate, polypropylene, acrylonitrile-butadiene-styrene, polycarbonate, % Polycarbonate, and a blend of about 50% acrylonitrile-butadiene-styrene, polybutylene terephthalate, rubber, glass ceramic and metal.

In one embodiment, the ink of the present invention is particularly preferably used for printing on a substrate comprising a low density polyethylene film.

In another preferred embodiment, the ink is preferably used for printing a substrate comprising a spunbond film laminate, in particular a polypropylene-based spunbond film laminate.

The ink preferably comprises polypropylene and more preferably is particularly preferably used for printing non-woven wipes comprising a polypropylene-based spunbond film laminate.

If desired, the substrate can be pretreated using, for example, plasma, corona discharge or a surfactant treatment to improve the adhesion of the ink to the substrate. For example, the substrate may be roughened or coated with an ink receptive coating.

In one embodiment, the method further comprises drying the ink applied to the substrate at a maximum of 70 캜, more preferably at most 65 캜, particularly at most 60 캜.

A second aspect of the present invention provides an inkjet printing method for printing an ink according to the first aspect of the present invention on a substrate by means of an inkjet printer. Preferably, in the second aspect of the present invention, the ink according to the first aspect of the present invention is printed on a substrate using an ink jet printer having an ink recycling print head.

The method of the present invention can use any inkjet printer having an ink recycling printhead. Preferably, the printhead has an ink recirculation channel in the ink supply system. These channels allow fresh ink to be used for injection, which can be part of the ink supply system or even be specially engineered channels that operate behind the nozzle plate. An ink supply system that operates behind the nozzle plate is desirable because it can use more volatile ink without compromising the restart / latency behavior. Recirculation behind the nozzle plate is exemplified by a commercially available FUJIFILM Dimatix printhead, such as Samba® or SG1024®.

A preferred type of recycle print head of the present invention is generally equipped with a reservoir heater and a thermistor to control the spray temperature. Preferably, the spray temperature in step (III) exceeds 30 占 폚.

Preferably, the drop volume of the ink applied by the ink jet printer is in the range of 1 to 100 pl.

As described above in step (I), when the ink of the first preferred embodiment is jetted, the droplet volume of the ink applied by the ink jet printer is preferably in the range of 20 to 100 pl and more preferably in the range of 20 to 40 pl And in particular from 25 to 35 pl.

As described above in step (I), when the ink of the second preferred embodiment is sprayed, the droplet volume of the ink applied by the ink jet printer is preferably in the range of 1 to 20 pl and more preferably 2 to 8 pl .

A third aspect of the present invention provides a substrate printed by the ink jet printing method described in the second aspect of the present invention using the ink described in the first aspect of the present invention. This substrate is as described in the first aspect of the present invention, and it is preferable that the substrate is preferably described.

Thus, in one embodiment, the printed substrate preferably comprises a low density polyethylene film.

In a second embodiment, the printed substrate is preferably a substrate comprising a spunbond film laminate, in particular a polypropylene-based spunbond film laminate.

More preferably, in a second embodiment, the printed substrate comprises a non-woven wipe, preferably comprising a nonwoven wipes comprising polypropylene and more preferably a polypropylene spunbond film laminate do.

According to a fourth aspect of the present invention, there is provided an inkjet printer ink container (e.g., a cartridge or a larger ink tank) containing the ink defined in the first aspect of the present invention.

A fifth aspect of the present invention is an inkjet printer having a recycling printhead as described in the second aspect of the present invention and an inkjet printer comprising the ink as described in the fourth aspect of the invention. Lt; / RTI >

A sixth aspect of the present invention provides an ink set comprising a black ink, a cyan ink, a yellow ink and a magenta ink, wherein the ink is as described in the first aspect of the present invention, Do. Preferably, the pigment in the black ink is carbon black; The pigment in the cyan ink is Pigment Blue 15: 3; The pigment in the yellow ink is Pigment Yellow 74 (or Pigment Yellow 155); The pigment in the magenta ink is Pigment Red 122. The ink set may also include a blue ink and a red ink. Preferably, the pigment in the blue ink is Pigment Blue 60, and the pigment in the red ink is Pigment Red 254.

Example

The present invention will now be illustrated by the following examples in which all parts are by weight unless otherwise stated.

The self-dispersible pigment used was Pro-Jet APD 1000 Black. Pro-Jet® APD 1000 The same ink can be prepared using cyan, magenta, yellow and yellow LF, red and blue. The Pro-Jet APD 1000 pigment dispersion is available from FUJIFILM Imaging Colorants Limited.

Surfynol® 440 and 465 are acetylenic surfactants from Air Products.

Rovene® 6102 is a styrene acrylic dispersion from Mallard Creek Polymer. The Tg of Rovene 6102 is 20 ° C and the acid number is 50 mg KOH / g.

Sancure® 20025F is an aliphatic polyester urethane polymer dispersion from Lubrizol.

NeoRez® R-551 is a polyurethane dispersion from DSM.

1,2-Benzisothiazolin-3-one was obtained as Proxel (R) GXL (20% solution) from Lonza.

Example Ink 1 ingredient 100% active ( Active ) ≪ / RTI > Wt %) Pro-Jet APD 1000 Black 2.00 Glycerol 3.75 Ethylene glycol 1.25 2 Pyrrolidone 95% 5.00 Surfynol 440 0.35 1,2-benzisothiazolin-3-one 0.004 Rovene 6102 5.50 Sancure 20025F 2.0 PEG 20K 6.2 Deionized water Remaining part to become 100 characteristic pH 8.6 Viscosity at 32 캜 cP 12.85 Surface tension D / cm 35.5

Example Ink 2 ingredient Formulation at 100% activity ( Wt %) Pro-Jet APD 1000 Black 2.00 Glycerol 3.75 Ethylene glycol 1.25 2 Pyrrolidone 95% 5.00 Surfynol 440 0.4 1,2-benzisothiazolin-3-one 0.004 Rovene 6102 5.50 NeoRez R-551 2.0 PEG 20K 6.2 Deionized water Remaining part to become 100 characteristic pH 8.6 Viscosity at 32 캜 cP 12.85 Surface tension D / cm 35.5

The inks of Examples 1 and 2 were printed through a StarFire (R) SG1024 recycle printhead from FUJIFILM Dimatix. StarFire® SG1024 recycle printheads are typically only used with non-aqueous inks because they tend to "wet" their faces when used with water-based inks, which adversely affects printer performance.

However, the ink of the above example was printed without any problem. The printhead was measured with a JetXpert drop watcher. There was no evidence that the ink of the present invention was a wetted faceplate.

Comparative Example Ink 1 ingredient Formulation at 100% activity ( Wt %)  Pro-Jet APD 1000 Black 2.00 Glycerol 3.75 Ethylene glycol 1.25 2 Pyrrolidone 95% 5.00 Surfynol 440 0.28 1,2-benzisothiazolin-3-one 0.015 Rovene 6102 7.50 PEG 20K 6.45 Deionized water Remaining part to become 100 characteristic pH 8.4 Viscosity at 32 캜 cP 13.3 Surface tension D / cm 35.6

Comparative Example Ink 2 ingredient Formulation at 100% activity ( Wt %)  Pro-Jet APD 1000 Black 2.00 Glycerol 3.75 Ethylene glycol 1.25 2 Pyrrolidone 95% 5.00 Surfynol 440 0.5 1,2-benzisothiazolin-3-one 0.02 Acrylic latex 5.50 PEG 20K 5.75 Deionized water Remaining part to become 100 characteristic pH 8.4 Viscosity at 32 캜 cP 14.36 Surface tension D / cm 35.54

Comparative Example Ink 3 ingredient Formulation at 100% activity ( Wt %)  Pro-Jet APD 1000 Black 2.00 Glycerol 3.75 Ethylene glycol 1.25 2 Pyrrolidone 95% 5.00 Surfynol 465 1.85 1,2-benzisothiazolin-3-one 0.02 Acrylic latex 7.50 PEG 20K 5.45 Deionized water Remaining part to become 100 characteristic pH 8.34 Viscosity at 32 캜 cP 13.24 Surface tension D / cm 35.38

Wet fastness to fastness ( Wet Crock - fastness )

The inks of Example 1 and Comparative Examples 1 and 2 were each printed on a polyolefin film.

Printing was evaluated for wet fastness to fastness using the protocol of the ASTM D5264 method as amended in F1571.

The results are shown below and the higher number reflects higher wet fastness.

Wet fastness Example Ink 1 2.89 Example Ink 2 3.20 Comparative Example Ink 1 1.24 Comparative Example Ink 2 2.2 Comparative Example Ink 3 1.53

Obviously, the ink of the present invention exhibited excellent wet fixation fastness as compared with the comparative ink.

Foam testing ( Foam Testing )

To test the ink resistance to foaming, 2 ml of ink was placed in a disposable 12 cm plastic test tube. Thereafter, air was bubbled through the ink for 2 minutes to form a foam. Thereafter, the ink was allowed to stand for 2 minutes so that the foam disappears. The measurement of the height of the foam formed on the ink was recorded at intervals of 30 s during the rise of the foam and during the disappearance of the foam. The test was carried out three times and the average results are shown in the table below.

time Liquid / foam height
Comparative Example Ink 1 Liquid / foam height
Example Ink 1 Liquid / foam height
Comparative Example Ink 3 0 0.40 cm 0.40 cm 0.40 cm 30 s 2.90 cm 2.80 cm 3.23 cm 60 s 4.70 cm 4.03 cm 5.33 cm 90 s 5.77 cm 5.40 cm 7.03 cm 120 s 7.00 cm 5.57 cm 8.53 cm Stop air flow 30 s 5.87 cm 5.33 cm 8.10 cm 60 s 4.63 cm 3.73 cm 7.10 cm 90 s 3.13 cm 2.17 cm 6.37 cm 120 s 1.50 cm 1.13 cm 5.47 cm

Obviously, the ink of the present invention showed a much lower foaming tendency than the comparative ink, and any foams formed disappeared much faster.

Claims (15)

An ink comprising:
(a) from 0.5 to 5 parts of a self-dispersible pigment;
(b) 2 to 8 parts of a styrene acrylate latex binder and / or a styrene butadiene latex binder;
(c) 0.5 to 5 parts of a polyurethane latex binder;
(d) 0-5 parts of a glycol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol or triethylene glycol;
(e) 1 - 10 parts of 2-pyrrolidone;
(f) 1 to 15 parts of glycerol;
(g) 0.1 to 3 parts of an acetylene surfactant;
(h) 0.001 to 5 parts biocide;
(i) 0 to 10 parts of a viscosity modifier; And
(j) the remainder of water to make 100 parts. The method according to claim 1,
The self-dispersible pigment of component (a) is selected from the group consisting of carbon black; Pigment Blue 15: 3; Pigment Blue 60; Pigment Yellow 74; Pigment Yellow 155; Pigment Red 254, and Pigment Red 122. 3. The method according to claim 1 or 2,
Wherein the self-dispersible pigment of component (a) comprises a carboxy-functional dispersant bridged around the pigment core by two or more epoxy groups. 4. The method according to any one of claims 1 to 3,
Component (b) is a styrene acrylic latex binder. 5. The method according to any one of claims 1 to 4,
And the component (c) is in the range of 1 to 3.0 parts. 6. The method according to any one of claims 1 to 5,
Component (d) is ethylene glycol. 7. The method according to any one of claims 1 to 6,
Component (e) is present in the range of 2.5 to 7.5 parts. 8. The method according to any one of claims 1 to 7,
Component (f) is present in the range of 2 to 7.5 parts. 9. The method according to any one of claims 1 to 8,
Wherein the component (g) is 2,4,7,9-tetramethyl-5-decyne-4,7-diol. 10. The method according to any one of claims 1 to 9,
Wherein component (i) is polyethylene glycol. The method according to claim 1,
An ink comprising:
(a ') 0.75 to 4 parts of a self dispersible pigment;
(b ') 4 to 10 parts of a styrene acrylate latex binder;
(c ') 1 to 3 parts of a polyurethane latex binder;
(d ') 0.5 to 2.5 parts of ethylene glycol;
(e ') 2.5 to 7.5 parts of 2-pyrrolidone;
(f ') 2 to 7.5 parts of glycerol;
(g ') 0.05 to 1.0 part of 2,4,7,9-tetramethyl-5-decyne-4,7-diol;
(h ') 0.001 to 2 parts of biocidal agent;
(i ') 3 to 8 parts of viscosity modifier; And
(j ') < / RTI > As an inkjet printing method,
An inkjet printing method, wherein the ink according to any one of claims 1 to 11 is printed on a substrate using an inkjet printer having an ink recycling printhead. A substrate printed by the inkjet printing method according to claim 12. An ink-jet printer ink container comprising the ink defined in any one of claims 1 to 11. An ink jet printer having an ink container containing an ink according to claim 14 and a recirculating printer head.