JP2002509976A - Composition - Google Patents

Abstract

  (57) [Summary] A composition comprising a water-dispersible acrylic polymer, water, a colorant, a water-immiscible organic solvent, and a water-miscible organic solvent. This composition can be used in thermal ink jet printers and piezoelectric ink jet printers.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to compositions containing certain acrylic polymers and their use in ink jet printing.

[0002] Ink jet printing is a method of printing a substrate through a fine nozzle.
te) Non-im printing an image on a substrate using ink droplets ejected onto the substrate without bringing the nozzles into contact with the substrate.
pact) printing method.

There are many performance requirements for colorants and inks used in ink jet printing. For example, it is desirable that these inks provide sharp, non-feathered images having good waterfastness, lightfastness and optical density. In addition, these inks are often required to dry quickly when applied to a substrate to prevent bleeding, but should not create a skin on the tip of the ink jet nozzle. Is to stop the operation of the printer. These inks should furthermore be storage-stable over time without decomposing or forming precipitates that can clog fine nozzles. The most popular ink jet printers are thermal ink jet printers and piezoelectric ink jet printers.

[0004] There is a need for inks that are suitable for both thermal and piezoelectric ink jet printers, have high color strength, and produce images with high lightfastness and waterfastness when printed on a substrate. ing. Many inks do not work in thermal ink jet printers and tend to foul the heater elements and clog nozzles.

[0005] According to a first aspect of the present invention, a water-dissipatable is used.
e) providing a composition comprising an acrylic polymer, water, a colorant, a water-miscible organic solvent and a water-immiscible organic solvent. Acrylic Polymer The water-dispersible acrylic polymer may optionally be a water-dispersing group.
one or more olefinically unsaturated monomers having an aqueous dispersing group (olef) in the presence of one or more olefinically unsaturated monomers without a sing group
It is preferably obtained from the polymerization of essentially unsaturated monomers.

[0006] The number average molecular weight (Mn) of the acrylic polymer is preferably less than 25,000, more preferably less than 20,000, especially 15,000. The Mn of the acrylic polymer can be measured by gel permeation chromatography ("gpc").

The gpc method used to measure Mn preferably applies the acrylic polymer to a chromatography column packed with cross-linked polystyrene / divinylbenzene, elutes the column with tetrahydrofuran at a temperature of 40 ° C., Mn is compared to known Mn values on a polystyrene basis to evaluate the Mn of the acrylic polymer. Suitable cross-linked polystyrene / divinylbenzene chromatography columns are commercially available from Polymer Laboratories.

[0008] If the gpc method for measuring Mn does not work for any reason, for example if the polymer has unexpected interactions with the gpc column and produces unrealistic results, an alternative method Can be used to measure Mn, for example, by vapor phase osmometry.

The acrylic polymer is preferably from 0 to 300 mg KOH / g, more preferably from 2 to 300 mg KOH / g.
It has an acid number of 0-250 mg KOH / g, especially 50-225 mg KOH / g. The dispersing group confers a self-dispersing and dissolving function to the acrylic polymer in the ink medium, especially in water. The dispersing group can be an ionic dispersing group, a non-ionic dispersing group, or a mixture of an ionic dispersing group and a non-ionic dispersing group. Preferred ionic dispersing groups include cationic quaternary ammonium groups and acid groups, such as phosphoric, sulfonic and carboxylic groups.

As a monomer or oligomer having a suitable dispersing group, a dispersing group can be incorporated into the acrylic polymer. Acrylic polymers that are not water-dispersible can also be reacted with monomers or oligomers that make the acrylic polymer water-dispersible.

Thereafter or during the formation of the polymer, the acid groups can be completely or partially neutralized by a base containing a cationic charge to form a salt. If an acid dispersing group is used in combination with a non-ionic dispersing group, neutralization may not be necessary. It is contemplated that the conversion of any free acid groups to the corresponding salt occurs during the preparation of the acrylic polymer and / or during the preparation of the ink from the acrylic polymer.

[0012] Preferably, the base used to neutralize any acid dispersing groups is ammonia, an amine or an inorganic base. A suitable base is a tertiary amine, for example triethylamine or triethanolamine. Suitable inorganic bases include alkali metal hydroxides and carbonates, such as lithium hydroxide, sodium hydroxide or potassium hydroxide. Quaternary ammonium hydroxide, for example ^{_{N + (CH 3) 4 OH}} - , can also be used. Generally, bases are used that provide the necessary requisite counterions for compositions made from acrylic polymers. For example, suitable counterions include Li ⁺ , Na ⁺ , K ⁺ , NH ₄ ⁺ , and substituted ammonium salts, including tetrasubstituted amines such as (CH ₃ ) ₄ N ⁺ .

[0013] The nonionic dispersing group may be any of an in-chain group, a pendant group, and a terminal group. Preferably, the non-ionic dispersing group is a pendant polyoxyalkylene group, more preferably a polyoxyethylene group. The nonionic group can be introduced into the acrylic polymer as a compound having a nonionic dispersing group and at least one (preferably only one) copolymerizable olefinically unsaturated group.

The nature and level of the dispersing groups in the acrylic polymer depends on the dispersion of the acrylic polymer (
It affects whether a solution, dispersion, emulsion or suspension is formed during the dissociation.

The dispersing group content of the acrylic polymer can vary within a wide range but is preferably sufficient to cause the acrylic polymer to form a stable ink jet printing ink in water or an aqueous medium. Preferably, the acrylic polymer is soluble in water, but when mixed with an aqueous medium or water, a small amount of the acrylic polymer is insoluble in water and can be present as dispersed particles.

The proportion of insoluble water-dispersible acrylic polymer is preferably less than 50% by weight, more preferably less than 40% by weight and most preferably less than 30% by weight, based on the total weight of the acrylic polymer. The size of the insoluble acrylic polymer particles when dispersed in the ink is preferably less than 100 nm, more preferably less than 60 nm.

When producing an acrylic polymer by polymerizing (a) an olefinically unsaturated monomer to which a dispersing group is applied in the presence of (b) an olefinically unsaturated monomer having no dispersing group, (b) Is preferably from 1 to 95% by weight, more preferably from 2 to 90% by weight, based on the weight of (a) + (b).

The acrylic polymer is produced by a conventional method by polymerizing an olefinically unsaturated monomer to which a dispersing group is applied, alone or in the presence of an olefinically unsaturated monomer having no dispersing group. Can be. Temperatures between 20C and 180C are preferred. The polymerization can be continued until the reaction between the monomers is completed.

In one embodiment, an acrylic oligomer having a water dispersing group and one olefinically unsaturated end group is combined with one or more olefinically unsaturated monomers having no water dispersing group and / or a water dispersing group. An acrylic polymer can be produced by polymerizing in the presence of an olefinic unsaturated monomer having the same. Alternatively, an acrylic oligomer having no water dispersing group can be polymerized in the presence of one or more olefinically unsaturated monomers having a water dispersing group.

[0020] Preferred polymerization methods include solution polymerization, emulsion polymerization, suspension polymerization, and solution / dispersion polymerization, and such general methods are well known in the art. If desired, an initiator can be used to promote polymer formation. Suitable initiators are free-radical gens
eaters). Examples of catalysts include azobis compounds, peroxides, hydroperoxides, redox catalysts, such as potassium persulfate, ammonium persulfate, t
tert-butyl peroctoate, benzoyl peroxide, isopropyl percarbonate, 2
, 4-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, azobisisobutyronitrile, azobis (2-amidino-propane) hydrochloride and the like.

Typically, 0.05 to 5% by weight of initiator is used, based on the total weight of the monomers. It is preferred to carry out the polymerization in the presence of an emulsifier. The Mn of the acrylic polymer can be controlled by the addition of chain transfer agents and / or by adjusting the ratio of monomer concentration based on the initiator concentration during the polymerization. Typical chain transfer agents are thiols, halocarbons, and cobalt macrocycles. Applying the preferred monomeric ionic dispersing groups, preferred olefinically unsaturated monomers are acrylic acid, methacrylic acid, itaconic acid, maleic acid, monoalkyl itaconates (e.g., monomethyl maleate, monoethyl maleate, monobutyl maleate and Monooctyl maleate), citraconic acid, styrene sulfonic acid, vinylbenzyl sulfonic acid, vinyl sulfonic acid, acryloyloxyalkyl sulfonic acid (for example, acryloyloxymethyl sulfonic acid, acryloyloxyethyl sulfonic acid, acryloyloxypropyl sulfonic acid and acryloyloxy) Butylsulfonic acid), methacryloyloxymethylsulfonic acid, methacryloyloxyethylsulfonic acid, methacryloyloxypropylsulfonic acid and methacryloyloxy Butylsulfonic acid), 2-acrylamido-2-alkylalkanesulfonic acid (for example, 2-acrylamido-2-methylethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid and 2-acrylamido-2-methylbutanesulfonic acid) ), 2-methacrylamido-2-alkylalkanesulfonic acids (eg, 2-methacrylamido-2-methylethanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, and 2-methacrylamido-2-methylbutanesulfonate) Acid), mono (acryloyloxyalkyl) phosphates (e.g., mono (acryloyloxyethyl) phosphate and mono (3-acryloyloxypropyl) phosphate), and mono (methacryloyloxyalkyl) phosphate (e.g., If encompasses mono (methacryloyloxyethyl) phosphate and mono (3-methacryloyloxypropyl) phosphate).

Preferred olefinically unsaturated monomers to which a nonionic dispersing group is applied include alkoxypolyethylene glycol (meth) acrylates, preferably having a number average molecular weight of 350-2000. Examples of such monomers, which are commercially available, include ω-methoxy polyethylene glycol acrylate (polyethylene glycol has an average degree of polymerization of about 9) and diethylene glycol vinyl ether.

Preferred olefinically unsaturated monomers that do not contain a dispersing group are alkyl (meth)
Acrylate, styrene optionally substituted, methacrylamide, allyl compound,
Includes vinyl ethers, vinyl ketones, vinyl halides, olefins and unsaturated nitriles.

Preferred alkyl (meth) acrylates contain less than 20 carbon atoms.
Such examples include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, tert.
-Octyl acrylate, 2-phenoxyethyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4-chlorobutyl acrylate, cyanoethyl acrylate, 2-acetoxyethyl acrylate, dimethylaminoethyl acrylate, benzyl acrylate, methoxybenzyl acrylate, 2 -Chlorocyclohexyl acrylate, acylate
, Cyclohexyl acylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, phenyl acrylate, hydroxyethyl (methyl) acrylate, hydroxypropyl (meth) acrylate, 5-hydroxypentyl acrylate, 2,2-dimethyl-3-hydroxypropyl acrylate, 2 -Methoxyethyl acrylate, 3-methoxybutyl acrylate, 2-ethoxyethyl acrylate, 2-iso-propoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-methoxyethoxy) ethyl acrylate, 2- (2
-Butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate , S
ec-butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, N-ethyl-N-phenylaminoethyl methacrylate, 2- (3-phenylpropyloxy) ethyl methacrylate, dimethylaminophenoxy Includes ethyl methacrylate and furfuryl methacrylate.

Preferred styrene which may be substituted is styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, chloromethyl styrene, trifluoromethyl Styrene, ethoxymethylstyrene, acetoxymethylstyrene, methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene , Trifluorostyrene and 2
-Bromo-4-trifluorostyrene.

Preferred methacrylamides contain less than 12 carbon atoms. Examples are methyl methacrylamide, tert-butyl methacrylamide, tert-butyl methacrylamide, tert-octyl methacrylamide, benzyl methacrylamide, cyclohexyl methacrylamide, phenyl methacrylamide, dimethyl methacrylamide, dipropyl methacrylamide, hydroxyethyl-N -Methylmethacrylamide, N-methylphenylmethacrylamide, N-ethyl-N-phenylmethacrylamide and methacrylhydrazine.

Preferred allyl compounds are allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, allyloxyethanol, allyl butyl ether and allyl Phenyl ether.

Preferred vinyl ethers contain less than 20 carbon atoms. Examples are methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, hydroxyethyl vinyl ether, and dimethyl Includes aminoethyl vinyl ether.

Preferred vinyl ketones contain less than 12 carbon atoms. Examples include methyl vinyl ketone, phenyl vinyl ketone and methoxyethyl vinyl ketone. Preferred vinyl halides include vinyl chloride, vinylidene chloride and chlorotrifluoroethylene.

Preferred olefins include unsaturated hydrocarbons having less than 20 carbon atoms. Examples are dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 5-methyl-1-nonene , 5,5-dimethyl-1-octene,
4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 5-methyl-1
-Hexene, 4-methyl-1-heptene, 5-methyl-1-heptene, 4,4-
Includes dimethyl-1-hexene, 5,5,6-trimethyl-1-heptene, 1-dodecene and 1-octadecene.

Preferred unsaturated nitriles include acrylonitonyl and methacrylonitrile. Preferred olefinically unsaturated monomers without dispersing groups are the alkyl (meth) acrylates containing less than 20 carbon atoms, especially the alkyl (meth) acrylates specifically listed above.

The acrylic polymer of the present invention can, if necessary, be purified in the usual way for colorants used in ink jet printing inks. For example, ion exchange, filtration, reverse osmosis, dialysis, ultrafiltration (ul
(tra-filtration) or a combination thereof. In this way, co-solvents, low molecular weight salts, impurities and free monomers used in the polymerization can be removed. Colorants Preferably , the colorant is soluble in the acrylic polymer. The colorant is preferably soluble in organic solvents and insoluble in water; for example, the colorant has no sulfo and carboxy groups. In a preferred embodiment, the colorant is a dye,
More preferred are dyes that are soluble in organic solvents and insoluble in water, especially disperse dyes.

The colorant is preferably yellow, magenta
), Cyan or black. The colorant may be a single coloring component or a mixture of coloring components, for example, a mixture of various dyes. By using mixtures of different dyes as colorants, great flexibility in the color of the ink can be achieved.

Useful types of coloring agents include anthraquinones, phthalocyanines, pyrrolines, triphenodioxazines, methines, benzodifuranones, coumarins, indoanilines, benzenoids, xanthenes, phenazines, solvents Soluble sulfur dyes, quinophthalones, pyridones, aminopyrazoles,
Pyrrolidines, styryl compounds (styrics) and azo compounds (a
zoics). Examples of preferred azo compounds are monoazo, disazo and trisazo disperse dyes, each of which is a metal-soluble, solvent-soluble dye; particularly preferred azo compounds contain a heterocyclic group. Color
Index International lists suitable disperse and solvent soluble dyes, examples of which are Solvent Blue 63, Disperse.
Blue 24, Solvent Black 3, Solvent Black
k 35 and Disperse Red 60.

Another example of a disperse dye is Color Index, Third Edition, Volume 2, 2483-2.
Other examples of solvent-soluble dyes are described in Volume 3, 3566-364.
Each of these dyes is described on page 7 and is incorporated herein.

Preferred colorants for use in the ink are CuPc (SO ₂ NHCH ₂ CH ₂ CH ₂ N (CH ₃ ) _2.7 (SO ₃ H) _0.3 (where Pc is phthalocyanine) and

[0037]

Embedded image

Is as follows. Water-miscible organic solvents suitable water-miscible organic solvent, C ₁ -C ₅ alkanols such as methanol, ethanol, n- propanol, isopropanol, n- butanol, sec- butanol, tert- butanol and isobutanol; amides, e.g. dimethylformamide and dimethylacetamide; ketones and ketone alcohols such as acetone and diacetone alcohol; C ₂ -C ₄ ethers, such as tetrahydrofuran and dioxane; alkylene glycol or thioglycolic containing C ₂ -C ₆ alkylene radical, such as ethylene glycol, Propylene glycol, butylene glycol, pentylene glycol and hexylene glycol; poly (alkylene glycol) and thioglycol) such as diethylene glycol, thiodiglyco Polyol, for example, glycerol and 1,2,6-hexanetriol; lower alkyl glycol and polyglycol ether, for example, 2-methoxyethanol, 2- (2-methoxyethoxy) ethanol, 2- (2 -Ethoxyethoxy) ethanol, 2- (
2-butoxyethoxy) ethanol, 3-butoxypropan-1-ol, 2-
[2- (2-methoxyethoxy) -ethoxy] ethanol, 2- [2- (2-ethoxyethoxy) -ethoxy] ethanol; cyclic esters and cyclic amides such as optionally substituted pyrrolidone; sulfolane; And mixtures containing two or more of the organic solvents. Preferred water-miscible organic solvent is a C ₁ -C ₆ alkyl monoethers of C ₁ -C ₆ alkyl monoethers and poly C ₂ -C ₆ alkylene glycol (C ₂ -C ₆ alkylene glycol). Water-immiscible organic solvents Suitable water-immiscible organic solvents are aromatic hydrocarbons, such as toluene, xylene,
Naphthalene, tetrahydronaphthalene and methylnaphthalene; chlorinated aromatic hydrocarbons such as chlorobenzene, fluorobenzene, chloronaphthalene and bromonaphthalene; esters such as butyl acetate, ethyl acetate, methyl benzoate, ethyl benzoate, benzyl benzoate and benzoic acid Butyl, phenylethyl acetate, butyl lactate, benzyl lactate, diethylene glycol dipropionate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di (2-ethylhexyl) phthalate;
Alcohols having 6 or more carbon atoms, such as hexanol, octanol,
Benzyl alcohol, phenylethanol, phenoxyethanol, phenoxy propanol and phenoxy butanol; ethers having at least 5 carbon atoms, preferably C ₅ -C ₁₄ ethers such as anisole and phenetole; nitrocellulose, cellulose ether, cellulose acetate; low odor petroleum Distillate;
Turpentine; white spirit (white s)
naphtha; isopropyl biphenyl; terpenes; vegetable oils; mineral oils; essential oils; and natural oils; and mixtures of any two or more of these. Benzyl alcohol is particularly preferred. Preferred Formulations The composition according to the first aspect of the present invention can be prepared by mixing the acrylic polymer, colorant, water, water-miscible organic solvent and water-immiscible organic solvent in any order. Suitable mixing methods are well known in the art, such as, for example, agitation, sonication or stirring of the components. Acrylic polymers are in any form that is particularly suitable for use in ink jet printing, including forms suitable for dilution to obtain an ink jet printing ink, such as dispersions, emulsions, suspensions, and the like. It may be present in the composition as a liquid, a solution or a combination thereof.

Preferably, the composition is prepared by mixing a dispersion of the acrylic polymer in the first liquid medium with a solution of the colorant in the second liquid medium, wherein the first liquid medium is optionally mixed with water. And a second liquid medium comprising a water-immiscible organic solvent and optionally a water-miscible organic solvent.

The weight ratio of the water-miscible organic solvent to the water-immiscible organic solvent in the ink is preferably 19: 1 to 1: 1, more preferably 8: 1 to 1: 1, particularly 5: 1 to 1 :. It is one.

The amount of the colorant and the amount of the water-dispersible acrylic polymer contained in the composition vary depending on the required depth of the shade. However, the composition typically comprises (a
0.5) to 50 parts, more preferably 2 to 20 parts, of a water-dispersible acrylic polymer (preferably having a weight average molecular weight of less than 50,000 or Mn of less than 25,000); 1 to 20 parts, more preferably 0.5 to 10 parts, especially 0.5
(C) 40 to 90 parts, more preferably 50 to 80 parts of water, (d)
2) 30 parts, more preferably 5 to 15 parts, especially 8 to 12 parts of a water-immiscible organic solvent, and (e) 2 to 60 parts, more preferably 5 to 25 parts, especially 10 to 20 parts Water-miscible organic solvents, where all parts are parts by weight and (a) + (b) +
The total number of copies of (c) + (d) + (e) is 100 in total.

The number of parts of the water-dispersible acrylic polymer is calculated based on 100% solids. For example, 50 g of 20% solids acrylic polymer is considered 10 g of acrylic polymer.

The composition may optionally comprise other components of the type commonly used in ink jet printing inks, such as biocides, such as Proxel GXL (Proxel is Zene
is a trademark of ca Limited) or Kathon (Kathon is a trademark of R
ohm and Haas), fungicides, rheological agents such as waxes (eg, beeswax), clays (eg, bentonite), IR absorbers such as Projet 900NP (Projet is Zeneca Limited).
Or a fluorescent brightener.
ner), for example, C.I. I. Fluorescent Brighttener 1
79 and / or UV absorbers such as hydroxyphenylbenzotriazole. Further, the ink composition optionally comprises a surfactant, a wetting agent and / or an emulsifier,
For example, McCutcheon's Emulsifiers and Dete
rgents 1996, International Edition or Surfactants Europa
Third edition 1996 may be included, each of which is incorporated herein by reference.

[0044] The composition preferably has a pH of 3 to 11, more preferably a pH of 4 to 10. The choice of pH will depend in part on the cation desired for the colorant and the materials used to construct the ink jet printer head. The desired pH can be obtained by the addition of acids, bases or pH buffers. If a base is used, it is preferably the same base that was used to neutralize the anionic dispersing groups during the production of the acrylic polymer.

The viscosity of the composition at 20 ° C. is preferably less than 20 cp, more preferably less than 15
less than cp, especially less than 10 cp. The composition of the present invention can be used for a piezoelectric ink jet printer, a thermal ink jet printer, and a continuous ink jet printer. Many other compositions based on polymers do not work well or even do not work at all in thermal ink jet printers.

The compositions of the present invention have little tendency to spread on the substrate, and have discrete droplets (di).
forming a “screte drop”. As a result, it is possible to obtain a clear image having excellent print quality and almost no bleeding between colors printed side by side. In addition, the inks have good storage stability, moisture and light fastness, and both acidic and alkaline highlighter pens.
r pen).

The composition is preferably filtered through a filter having an average porosity of less than 10 μm, more preferably less than 5 μm, especially less than 1 μm. using this method,
In other cases, particulate matter that may have clogged the printer head is removed.

Preferably, the composition is an ink, in particular an ink jet printing ink, or a liquid that can be used to make such an ink. Another aspect of the present invention is a method for printing an image on a substrate, comprising the first aspect of the present invention.
Provided is a method as described above, comprising applying the composition according to the embodiment onto a substrate by an ink jet printer.

[0049] The ink jet printer preferably applies the composition to the substrate as small droplets that are ejected onto the substrate through small nozzles. Preferred ink jet printers are piezoelectric ink jet printers and thermal ink jet printers. In thermal ink jet printers, a register adjacent to the nozzle applies a programmed heat pulse to the composition in the reservoir, thereby causing a small movement directed toward the substrate during relative movement between the substrate and the nozzle. Inject the composition as drops. In a piezoelectric ink jet printer, the vibration of small crystals causes the composition to be ejected from a nozzle.

The substrate is preferably a paper, plastic or fibrous material, more preferably a paper, an overhead projector slide.
vector or fiber material, especially paper.

Preferred papers are plain papers, coated papers or processed papers, which can have acidic, alkaline or neutral properties. Most preferably, the substrate is a coated paper. According to a further feature of the present invention there is provided an ink jet printer cartridge containing a composition as defined above.

The invention will now be described by way of example only. All parts and percentages are by weight unless otherwise specified. In the examples, the compounds mentioned in connection with the CI value are the dyes identified by these numbers in the Color Index International, 3rd edition, 3rd edition. Example 1 Preparation stage 1 of water-dispersible acrylic terpolymer: BA / MMA / AA = 50/35/15 ( % by weight )

[0053]

[Table 1]

AIBN is azobisisobutyronitrile. 1,2,3,4 and 6 were added to a 1 liter baffled round bottom flask equipped with stirrer and condenser and heated gradually to a reaction temperature of 80 ° C under a flow of dry nitrogen with stirring. After 3 hours at this temperature, the polymerization is complete. The solids content was 29.8% by weight.

After the mixture was cooled, the butyl acetate was removed by rotary evaporation to give the water-dispersible acrylic polymer as a viscous resinous material. This polymer has an M of 4980
n; Tg = -13.7 ° C; acid value = 115 mg KOH / g ("Resin 1").

Next, resin 1 (30 g) was added to a solution of ammonia (4 g) in water (66 g), dissolved with gentle stirring, and heated to obtain a 30% by weight solids dispersion in water. Was. Step 2-Preparation of Ink 1 A sample (3 g) of a solvent-soluble phthalocyanine dye was prepared by adding
0 g) and 2-pyrrolidone (20 g) in a mixture of an ultrasonic generator (sonic).
ator). Resin 1 from Step 1 adjusted to pH 9.5 (30
g, a 30% by weight dispersion in water (discipiation) and water (37 g) were added and the mixture was shaken to give Ink 1 having the following composition: Component amount (g) Dye 3 Resin 130 (30% solids) Benzyl alcohol (immiscible) 10 2-Pyrrolidone (miscible) 20 Water 37 100 Examples 2-6 Step 1 Except for using the following components in place of the components described in Example 1 The procedure described in Example 1, Step 1 was repeated:

[0057]

[Table 2]

Abbreviations: BA is n-butyl acrylate. BAC is butyl acetate. MMA is methyl methacrylate.

MA is methacrylic acid. 3-BM is 3-butyl mercaptan. AIBN is azobisisobutyronitrile. The water-dispersible polymers obtained from Examples 2 to 6 (resins 2 to 6, respectively) had the following properties:

[0060]

[Table 3]

N / M means not measured. Step 2- An ink was prepared by the method of Example 1, Step 2, except that the ingredients of Inks 2-6 were used in the amounts shown in the table below:

[0062]

[Table 4]

Note: Resins 2, 3 and 4 had a solids content of 20% and resins 5 and 6 had a solids content of 30%. The dye is the same phthalocyanine dye as the dye used in Example 1. Comparative Example 1 Preparation of High-Molecular-Weight Hydrophobic Styrene-Acrylic Derivative Ink C1 A sample (3 g) of the phthalocyanine dye used in Example 1 was mixed in a mixture of benzyl alcohol (10 g) and 2-pyrrolidone (20 g). It melt | dissolved using the sound wave generator. Neocryl BT44 (20 g, Zeneca Resins
(45% by weight dispersion in water) and water (47 g) were added and the mixture was shaken to give an ink C1 having the following composition: component amount (g) dye 3 Neocryl BT44 20 (45) % Solid content) Benzyl alcohol (immiscible) 10 2-Pyrrolidone (miscible) 20 Water 47 100 Comparative example 2-Preparation of non-acrylic polymer ink C2 Sample (1 g) of phthalocyanine dye used in Example 1 was benzyl The mixture was dissolved in a mixture of alcohol (10 g) and 2-pyrrolidone (20 g) using an ultrasonic generator. Water (69 g) was added and the mixture was shaken to give ink C2 having the following composition: component amount (g) dye 1 benzyl alcohol (immiscible) 10 2-pyrrolidone (miscible) 20 water 69 100 Ink C2 was found to be unstable on storage overnight and the dye precipitated from the lysate. Therefore, freshly manufactured samples were used for the tests described in Table 1 below. Example 7-Ink jet printing inks 1-6 using the above inks and inks C1 and C2 were used with Arjo Wiggins Limit
100g of Condor High White Wove plain paper from ed
On / M ² were printed have use a thermal ink jet printer of Hewlett Packard. The properties of the prints obtained are shown in Table 1 below.

The prints obtained from Inks 1 and C2 showed very good color strength and sharpness (chroma), as shown in Table 1.
, And showed very high water fastness. 0.5 ml of water, which was flushed on the test prints only 5 minutes after printing, did not substantially stain on white paper. However, ink C2 had the disadvantage of poor storage stability.
Table 1

[0065]

[Table 5]

N / M means not measured. ROD is the reflected optical density (reflected optica) of the resulting print.
l density).

The wet rub after 5 minutes was evaluated with a score of 1-10, where 1 is
Poor rub resistance is indicated, and 10 indicates excellent rub resistance.Example 8 It is possible to produce further inks having the compositions described in Tables 2 and 3 below.
The following abbreviations are used in the table. These inks are ink jet printers
Can be applied to plain paper. FRU: Fructose resin^*: Confirm which of the acrylic polymers produced in Examples 1 to 6 is to be used. BZ: benzyl alcohol DEG: diethylene glycol DMG: diethylene glycol monobutyl ether ACE: acetone IPA: isopropyl alcohol MEOH: methanol 2P: 2-pyrrolidone MIBK: methyl isobutyl ketone SUR: Surfinol 465 (surfactant) PHO: K_TwoPO_Four TEN: Triethanolamine NMP: N-methylpyrrolidone TDG: Thiodiglycol CAP: Caprolactam BUT: Butyl cellosolve GLY: Glycerol Resin: Resin 1 from Example 1 (30% dispersion in water) Colorant 1: CuPc (SO_TwoNHCH_TwoCH_TwoCH_TwoN (CH_Two)_Three)_2.7(SO_ThreeH) _0.3 (Wherein Pc is phthalocyanine) Coloring agent 2: Pyridone dye shown on page 10

[0068]

[Table 6]

[0069]

[Table 7]

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY , CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE , KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW (72) Inventor Holbrook, Mark Manchester M 9.8 GS, Black, UK Lee, P.O. Box 42, Hexagon House F-term (reference) BE01 BE12 CA06 EA35 EA38 EA41 EA42 GA24

Claims (13)

[Claims] 1. A composition comprising a water-dispersible acrylic polymer, water, a colorant, a water-miscible organic solvent and a water-immiscible organic solvent. 2. The acrylic polymer obtained from the polymerization of one or more olefinically unsaturated monomers having water dispersing groups, optionally in the presence of one or more olefinically unsaturated monomers having no water dispersing groups. The composition of claim 1, wherein the composition is 3. The composition according to claim 1, wherein the colorant is soluble in the acrylic polymer. 4. The water immiscible organic solvent is benzyl alcohol.
A composition according to any one of claims 1 to 3. 5. (a) 0.5 to 50 parts of a water-dispersible acrylic polymer, (b)
0.1 to 20 parts of a colorant, (c) 40 to 90 parts of water, (d) 2 to 30 parts of a water-immiscible organic solvent, and (e) 2 to 60 parts of a water-miscible organic solvent. 5. In this case, all parts are parts by weight and the total number of (a) + (b) + (c) + (d) + (e) totals 100. A composition according to any of the above. 6. The composition according to claim 1, wherein the acrylic polymer has a Mn of less than 25,000. 7. The composition according to claim 1, which has a viscosity at 20 ° C. of less than 20 cp.
The composition according to any one of the above. 8. The composition according to claim 1, which is used for an ink jet printer. 9. The composition according to claim 1, which is suitable for use in a thermal ink jet printer. 10. The composition according to claim 1, which has been filtered through a filter having an average pore size of less than 10 μm. 11. An ink jet printing ink according to claim 1. 12. A method for printing an image on a substrate, comprising applying the composition defined in any one of claims 1 to 11 on the substrate using an ink jet printer. 13. An ink jet printer cartridge containing the composition defined in claim 1.