JP3499953B2 - Ink jet ink and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording liquid having excellent water resistance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as ink jet recording liquids, water-soluble dyes such as acid dyes, direct dyes and basic dyes are dissolved in a glycol solvent and water (JP-A-53-53).
61212, JP-A-54-89811, JP-A-55-6
5269), which is commonly used. As the water-soluble dye, those having high solubility in water are generally used in order to obtain stability of the recording liquid. Therefore, the ink jet recorded matter generally has poor water resistance, and there is a problem that spillage of water easily causes bleeding of the dye in the recorded portion.

In order to improve such poor water resistance,
Attempts have been made to change the structure of the dye or to prepare a recording liquid having a strong basicity (JP-A-56-57862). Further, it has been attempted to improve the water resistance by making good use of the reaction between a recording paper and a recording liquid (Japanese Patent Laid-Open No. 50900/50).
4, JP-A-57-36692, JP-A-59-2069
6, JP-A-59-146889). Although these methods have a remarkable effect on a specific recording paper, they lack versatility in that they are restricted by the recording paper, and when a non-specific recording paper is used, a water-soluble dye is used. In many cases, the recording liquid used cannot obtain sufficient water resistance of the recorded matter.

Recording liquids having good water resistance include those in which an oil-soluble dye is dispersed or dissolved in a high boiling point solvent and those in which an oil-soluble dye is dissolved in a volatile solvent. There is a problem of the emission of sewage, which is not environmentally preferable.
In addition, there is a problem that solvent recovery or the like is required when a large amount of recording is performed or depending on the installation location of the device. Therefore,
In order to improve the water resistance of recorded matter, a recording solution in which a pigment is dispersed in an aqueous medium has been developed.

However, unlike dyes, pigments are insoluble in the recording medium, and it is very difficult to disperse them as fine particles and to keep their dispersed state stable. In addition, in the recording liquid for inkjet,
As the high resolution of printers is required, the diameter of nozzles is becoming thinner, and it is necessary to make the particle size of the coloring agent smaller, and the dispersion of the recording liquid becomes more stable as the size becomes smaller. It's getting harder to keep.
While exhibiting the characteristics of pigments, which are superior in water resistance and light resistance to dyes, adjustment to the ejection conditions of recording liquid, stability for long-term storage, fixing to non-recording media such as paper, image color, Further improvements have been required in order to obtain characteristics equivalent to or better than dyes with respect to required characteristics such as bleeding.

In addition to the above-mentioned required characteristics, the ink in which the pigment is dispersed is required to have contradictory characteristics such as re-solubility (re-dispersibility) with respect to a recording liquid and water resistance on a paper surface, like a dye. However, when a water-soluble resin is used, it is superior in terms of re-solubility (re-dispersibility), but it is difficult to obtain sufficient characteristics in terms of water resistance on paper. In addition, when a water-dispersible resin is used from the viewpoint of water resistance, the water resistance on the paper surface is good, but when ink adheres to the head part, etc., there is no redissolvability (redispersibility). However, there is a problem that stable ejection cannot be performed, the head cleaning mechanism does not function well, and the nozzle is clogged.

[Problems to be Solved by the Invention]

The present invention relates to an ink jet recording liquid which solves the above-mentioned problems of the conventional method and has good ejection stability at the nozzle. In addition, the present invention relates to an ink having excellent re-dissolvability (re-dispersibility) at the head while having sufficient water resistance on the paper surface.

[Means for solving the problem]

[0008] The present invention is an ink jet ink having dispersed therein a coloring agent in an aqueous liquid, acrylic acid as an aqueous resin, a styrene, consisting of α-methylstyrene acid
It is an inkjet ink using a terpolymer having a valence of 90 to 115 . The molecular weight of the terpolymer is 2000-
It is preferably 8000, more preferably 2
It is preferably from 000 to 5000 from the viewpoints of the dispersibility of the pigment and the ejection stability of the ink, and when carbon black is used as the colorant, the resistance value of the ink solid printed surface and the like. The terpolymer has an acid value of 90 to 115 because of its water resistance on the surface of paper and redissolvability of ink at the head, and when carbon black is used as the coloring agent, the resistance of the solid ink printed surface. It is preferable in terms of value and the like.

The terpolymer is preferably one obtained by copolymerizing 1 mol of acrylic acid with 3 to 5 mol of styrene and α-methylstyrene in total. Furthermore, styrene 1.5-2.
It is preferable to copolymerize 5 moles and 1.5-2.5 moles of α-methylstyrene, and particularly 1.7-2.3 moles of styrene and 1.8-2 moles of α-methylstyrene for 1 mole of acrylic acid. Those obtained by copolymerizing 0.2 mol are preferable.
By copolymerizing the monomers in such a ratio, dispersion stability, water resistance, redissolvability, and a high resistance value in terms of solid image formation can be obtained in a well-balanced manner when carbon black is used as a colorant. . These terpolymers can be copolymerized by a known method.

In the ink-jet ink of the present invention, it is desirable to use a neutralizing agent in order to stably dissolve the terpolymer in the liquid component of the recording liquid. Some sodium and potassium hydroxides, aliphatic amines, ethanolamines, propanolamines, alcoholamines such as methylethanolamine,
Morpholine, N-methylmorpholine, dimethylaminoethanol, diethylaminoethanol and the like can be used as a neutralizing agent. When these neutralizing agents are used in an equimolar to several percent excess of acrylic acid in the terpolymer, solubility of the terpolymer, resolubility of the terpolymer, recording It is desirable because the water resistance of the product can be adjusted well.

In the present invention, the terpolymer is preferably used in the ink in an amount of 0.5 to 8% by weight. If it is less than this, when carbon black is used as the colorant, the conductivity due to carbon becomes high, and the risk of short-circuiting at the deflection electrode or the like increases in a continuous type multi-head. On the other hand, if the amount is larger than this, it becomes difficult to set the viscosity of the ink to be low, and droplets cannot be sufficiently generated.

The ink-jet ink of the present invention comprises 0.5 to 8 parts by weight of the terpolymer and 0.5 to 0.5 parts of a colorant.
5 parts by weight, antifungal agent 0.03 to 0.5 parts by weight, water 50 to 9
It is desirable to use 5 parts by weight.

In the present invention, a pigment is used as the colorant. Examples of pigments include carbon black, and examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, hansa yellow, benzidine yellow, and pyrazolone red, and soluble azo such as litol red, heliobordeaux, pigment scarlet, and permanent red 2B. Derivatives from vat dyes such as pigments, alizarin, indanthrone, thioindigo maroon, phthalocyanines such as phthalocyanine blue and phthalocyanine green, quinacridones such as quinacridone red and quinacridone magenta, perylenes such as perylene red and perylene scarlet, iso Isoindolinone series such as indolinone yellow, isoindolinone orange,
Pyranthrone red, pyranthrone orange and other pyranthrone, thioindigo, condensed azo, thioindigo, and other pigments such as flavanthrone yellow, acylamide yellow, quinophthalone yellow, nickel azo yellow, copper azomethine yellow, perinone orange, Anthrone orange, dianthraquinonyl red, dioxazine violet, etc. are used, and it is desirable to be selected from the group consisting of carbon black, phthalocyanine organic pigments and azo organic pigments.

It is preferable that these pigments are adjusted to be suitable for use as they are in an aqueous dispersion state immediately after the production of the pigment, or by subjecting them to various fine particle treatments (for example, acid pasting). The colorant used in the present invention is dispersed in an aqueous medium together with the terpolymer, or is dispersed in the terpolymer in advance and then diluted with the aqueous medium to produce an inkjet ink. The preferred particle size of the dispersed pigment is 0.5 μm or less, preferably 0.2 μm or less in terms of average particle size by a laser scattering method. With such a particle size, the ejection of the ink during recording is stable, the filtration operation in the production of the ink is easy, and the sedimentation of the recording liquid over time is reduced. The pigment is preferably used in the ink in an amount of 0.5 to 5 parts by weight, and if it is less than the above range, image density and color reproduction will be insufficient. On the other hand, if the amount is larger than this, the ejection stability is remarkably lowered, and the nozzles are likely to be frequently engaged. Also, it may be difficult to adjust the viscosity of the ink.

In the present invention, dyes can be used for the purpose of adjusting the hue of the pigment, imparting the concentration, etc. within the range where there is no problem in water resistance and light resistance. Depending on the use of the dye, the dispersion stability of the pigment may be deteriorated.
It is necessary to limit the use to less than or equal to 25% by weight, preferably less than or equal to 25% by weight. Acid dyes, basic dyes,
Direct dyes, reactive dyes, disperse dyes, metal-containing dyes, etc. are used. These dyes are preferably purified dyes from which inorganic salts have been removed.

The mildew-proofing agent prevents the generation of mildew in the recording liquid, and includes sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zincpyridinethione-1-oxide, 1,2. -Benzisothiazoline-3-one, 1-Benzisothiazolin-
3-amine amine salts and the like can be mentioned. It is desirable to use 0.03 to 0.5 part by weight of these in the recording liquid.

In the present invention, as the liquid component, not only water but mainly a humectant and an aqueous solvent are also used.
The humectant and the water-based solvent prevent the recording liquid from drying at the nozzle portion and solidifying the recording liquid, and prevent the stable ejection of the recording liquid and the drying of the nozzle over time. Examples of such moisturizers and aqueous solvents include ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, ketone alcohol, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether ethylene glycol mono. Examples thereof include ethyl ether, 1,2-hexanediol, N-methyl-2-pyrrolidone, substituted pyrrolidone, 2,4,6-hexanetriol, tetrafurfuryl alcohol and 4-methoxy-4methylpentanone.

Alcohols such as methanol, ethanol and isopropyl alcohol can be used in the ink of the present invention for the purpose of speeding up drying on paper. These aqueous solvents are used alone or as a mixture in the range of 1 to 50% by weight of the recording liquid. As the ink medium, ion-exchanged water or distilled water from which metal ions have been removed is used.

When the material to be printed is paper, a penetrant can be added to stop the ink from penetrating the paper and accelerate the apparent drying property. Examples of such penetrants include glycol ethers such as diethylene glycol monobutyl ether described as aqueous solvents, alkylene glycols, polyethylene glycol monolauryl ether, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium oleate, and sodium dioctylsulfosuccinate. Can be used. These have sufficient effects when used in an amount of 5% or less of the recording liquid,
If the amount is larger than this range, printing blurring and paper missing (print through) occur, which is not preferable.

The inks of the present invention are made by several methods. That is, a colorant, a dispersant, water, and optionally an aqueous solvent are mixed, a sand mill, a homogenizer,
Disperse with a ball mill, paint shaker, ultrasonic disperser, etc., and then add and mix the ternary copolymer solution. Alternatively, a colorant, a terpolymer, a dispersant, water and, if necessary, an aqueous solvent are mixed and dispersed by a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser or the like. Alternatively, a colorant and a terpolymer are thoroughly kneaded in advance by a two-roll mill, then further dispersed by the above sand mill, diluted appropriately with water, and mixed with other additives to prepare an ink. To do. The terpolymer may be used in a state of being sufficiently dissolved with a neutralizing agent in advance, and it is also effective to heat it for dissolution. Mixing and stirring is not limited to stirring by a stirrer using ordinary blades,
It can be performed by a high speed disperser, an emulsifier, or the like.

The mixed recording liquid may be used before dilution or
After that, with a filter having a pore size of 3 μm or less, preferably 1.
Sufficiently filter with a filter of 0 μ or less, more preferably a filter of 0.65 μ or less. Prior to the filtration of the filter, it is also possible to remove those having a large particle size by centrifugation, which can reduce the clogging of the filter during the filtration and the replacement of the filter.

The ink is preferably prepared as a liquid having a viscosity of 0.8 to 15 cps (25 ° C.), though it depends on the type of recording device. Surface tension is 25-60 dyn / cm
Is desirable. pH is not particularly limited, but 7
It is in the range of -12 and a weak alkalinity of 7-10 is preferred.

The ink of the present invention can be used in both a continuous type printer and an on-demand type printer. In a continuous type printer, the ink conductivity is adjusted so that the droplets are appropriately charged. Further, even when ink adheres to the deflection electrode, if the re-dissolving property (re-dispersing property) is excellent, the troubles due to the ink adhering and accumulating are reduced. Further, especially in the case of an ink using carbon black, a short circuit of current due to the ink at the deflection electrode may be a problem, but the ink of the present invention has a high resistance value after the ink is dried. , Such troubles can be reduced. In particular, by adding heat treatment after dispersion, the resistance value of the ink after drying can be increased, and specifically, the resistance value of the solid printed surface when solid printing is 10 ⁶ Ω (5 mm between electrodes) or more, preferably Is set to 10 ⁷ Ω or more, and such troubles can be significantly reduced. The reason why the resistance value of the solid printed surface when solid printing the ink is increased by heating and storage is considered to be that the phenomenon of the terpolymer covering the surface of the carbon black progresses. This coating phenomenon may reach the end point when the ink is stored at 60 to 80 ° C for about 5 to 24 hours, and the resistance value of the solid printing surface when the solid printing is performed even if the storage is continued for a longer time It didn't grow any bigger.

A chelating agent can be added to the ink of the present invention in order to prevent the deposition of metal at the nozzle portion and the deposition of insoluble substances in the ink. The chelating agent blocks metal ions in the ink,
About 0.005-0.5% of ethylenediaminetetraacetic acid, sodium salt of ethylenediaminetetraacetic acid, diammonium salt of ethylenediaminetetraacetic acid, tetraammonium salt of ethylenediaminetetraacetic acid, or the like can be used.

Further, in order to adjust the pH of the recording liquid to a desired pH and obtain the stability of the ink or the stability of the ink pipe in the recording apparatus, amines, inorganic salts, adjusting agents such as ammonia, phosphoric acid, etc. It is also possible to use the above buffer solution.

Further, an antifoaming agent may be added in order to prevent the circulation or movement of the ink or the generation of bubbles during the production of the recording liquid.

The following surfactants may be added for the purpose of dispersing the pigment and improving the quality of the image. As such a surfactant, an anionic, nonionic, cationic or amphoteric surfactant can be used.

The ink produced according to the present invention has excellent water resistance in spite of being water-based, and therefore, it is suitable for use as an ink-jet ink, and it is suitable for office documents such as document preparation, marking, cardboard marking, numbering, bar code, etc. It can be used in the field of recorded materials. In addition, it is superior to the dye ink in storability of recorded matter.

[0029]

EXAMPLES The present invention will be described below based on examples. Parts in the examples indicate parts by weight. Synthesis Example A terpolymer having the following monomer composition was synthesized according to the method of synthesizing an acrylic resin. Acrylic acid Styrene α Methylstyrene Acid value Molecular weight Synthesis example 1 1 1.8 2.0 105 105 3000 2 1 1.8 2.1 102 5000 5000 3 1 2.0 2.0 100 100 2000 4 1 2.0 2.2 95 3500 5 1 2.2 1.9 100 4000 6 1 1.7 1.8 115 3000

Example 1 Crude copper phthalocyanine (Oriental
Ink Manufacturing Co., Ltd., copper phthalocyanine): 250 parts,
Sodium chloride: 2500 parts, blue pigment dispersant (P-
[CH₂NH (CH ₂)_FourN (CH₃)₂]₃, P is copper
Phthalocyanine residue)) 25 parts and polyethylene glycol
Call 300 (Tokyo Kasei): 160 parts made of stainless steel
Charge 1 gallon kneader (manufactured by Inoue Seisakusho) and mix for 3 hours
Kneaded Then pour this mixture into 2.5 liters of warm water.
Put it in and heat it to about 80 ℃ with a high speed mixer
After stirring for about 1 hour to make a slurry, filter and wash with water 5
Repeatedly remove sodium chloride and solvent to remove solid
50% water-based pigment dispersion (pigment derivative treated pigment dispersion
Got a body). Place the following ingredients in a sand mill and disperse.
A concentrated recording liquid for ink jet was prepared. Synthesis example 1
The amount of the copolymer is a solid content equivalent amount.   Blue pigment (pigment derivative treated pigment dispersion, solid content 50%) 30 parts   3.0 parts of the copolymer of Synthesis Example 1   Dimethylaminoethanol 0.1 part   Dispersant (Kao Emulgen 420) 1.0 part   Purified water 50.0 parts   Glycerin 6.0 parts After dispersion, it was mixed with: 0.45μ after mixing
An ink was produced by filtering with a membrane filter.
Viscosity is 1.7 cps and particle size distribution is determined by laser diffraction
-Type particle size distribution meter ("SALD-110" manufactured by Shimadzu Corporation)
0 ”) and the average particle size was calculated to be 104 nm.
It was.   13.5 parts of the above dispersion   Dispersant (Emulgen 420 manufactured by Kao) 0.2 parts   1.0 part of the copolymer of Synthesis Example 1   Ethylene glycol 10.0 parts   Sodium omazine (Ohlin) 0.15 parts   Ethylenediamine tetraacetic acid sodium salt 0.02 parts   Purified water 63.53 parts This ink is a cartridge of HG5130 made by Epson.
When I put it in a disk and recorded it (piezo method),
I got a recording. Dripping water on the recording surface causes ink bleeding.
However, there was no ink bleeding or running out, and
It was aqueous. Also, wipe the recording surface with a cotton swab dipped in water.
It was rubbed 0 times, but no ink adhered to the cotton swab.

Example 2 The following raw materials were put into a sand mill and dispersed to prepare a concentrated recording liquid for inkjet. The amounts of the copolymers in Synthesis Examples 1 and 2 are solid equivalent amounts. Carbon black (Mitsubishi Kasei Corp. MA-7) 4.0 parts of a blue pigment dispersing agent (P- _{[CH 2 NH (CH 2) 4} N (CH 3) 2 ] ₃ P is copper phthalocyanine residue 0.1 Part Copolymer of Synthesis Example 2 3.0 parts Diethylaminoethanol 0.1 parts Dispersant (Emulgen 420 manufactured by Kao) 0.5 parts Dispersant (Solspers 27000 manufactured by Zeneca) 0.5 parts Purified water 50.0 parts Diethylene glycol mono 1.0 part of butyl ether was dispersed and then mixed with the following: After mixing, the mixture was filtered through a 0.45μ membrane filter to prepare an ink.
The viscosity was 1.6 cps and the average particle size was 100 nm as determined in the same manner as in Example 1. Dispersion 13.5 parts Dispersant (Emulgen 420 manufactured by Kao) 0.2 parts Copolymer of Synthesis Example 1 4.3 parts Ethylene glycol 10.0 parts Sodium omazine (manufactured by Ohrin) 0.15 parts Ethylenediaminetetraacetic acid Sodium salt 0.02 parts Purified water 63.53 parts When this ink was put in a cartridge of HG5130 manufactured by Epson Corp. and recording was performed, a good recorded matter was obtained. I drew water on the recording surface and checked for ink bleeding.
There was no ink bleeding or running out, and it had sufficient water resistance. Further, the recording surface was rubbed 10 times with a cotton swab soaked with water, but no ink adhered to the cotton swab.

[Example 3] The following materials were placed in a sand mill and dispersed to prepare an ink jet ink. In addition,
The amount of the copolymer of Synthesis Example 2 is the amount in terms of solid content. Carbon black dispersion (Hoechst Hostafine TS 33% solids) 9.5 parts blue pigment dispersing agent (P- _{[CH 2 NH (CH 2) 4} N (CH 3) 2 ] ₃ P copper phthalocyanine radical 0 1 part Dye (CI Direct Black 154) 0.5 part Copolymer of Synthesis Example 2 3.0 parts Diethylaminoethanol 0.2 parts Dispersant (Emulgen 420 manufactured by Kao) 0.4 parts Dispersant (manufactured by Zeneca) Solsparse 27000) 0.5 part Diethylene glycol monobutyl ether 1.0 part Ethylene glycol 1.0 part Sodium omazine (Ohlin) 0.15 part Ethylenediaminetetraacetic acid sodium salt 0.02 part Purified water 83.53 parts After dispersion, 1 μ Filter with a membrane filter of 0.45μ, and then filter with a 0.45μ membrane filter. The viscosity was 1.6 cps, and the average particle size was 94 nm as determined in the same manner as in Example 1. The obtained ink was coated on a coated paper with a No. 6 bar coater and dried. The resistance value of the coated surface can be measured by Mitsubishi Yuka's resistivity meter MCP-T.
When measured at 400, the distance between the 5 mm electrodes was 2.
A resistance value of 6 × 10 ⁶ Ω was exhibited, and similarly, with respect to the ink heated and stored at 70 ° C. for 12 hours, the same was applied to coated paper and dried, and the resistance value of the coated surface after drying was measured.
The resistance value was 10 ⁷ Ω or more. Put both of these inks (before heating and after heating) into Hitachi IJ printers (continuous method) and print on plain paper (Xerox
K) and art paper were recorded, and no matter which ink was used, continuous printing was possible without causing troubles at the time of printing at the deflection electrode section, and good recorded matter was obtained. . When water was dripped onto the recording surface of plain paper and bleeding of the ink was examined, there was no ink bleeding or running out, and it had sufficient water resistance. Further, the recording surface of the art paper was rubbed 10 times with a cotton swab soaked with water, but no ink adhered to the cotton swab. Since various materials such as stainless steel, nickel, and fluorine resin-coated iron are used for the nozzle, the ink obtained is applied to the stainless steel plate, nickel plate, and fluorine resin-coated iron plate surface, and left at room temperature for 7 days. When each plate was left to stand and immersed in the above ink, the solubility (dispersibility) of the dried surface of the ink was examined, and good resolubility (redispersibility) of the ink was confirmed.

[Examples 4 to 10] and [Comparative Examples 1 to 9] Inks were produced using the following resins in place of the terpolymer of Example 3. In addition, the compounding amount is shown as a solid content conversion amount in both Examples and Comparative Examples. Resin Acid value Molecular weight Blended amount Example 4 Synthesis example 3 100 2000 5 parts 5 4 95 3500 5 parts 6 5 100 100 5 parts 7 6 115 115 3000 4 parts 8 4 95 3500 4 parts 9 5 100 4000 4000 4 parts 10 6 115 3000 4 parts Comparative Example 1 A-St 150 6800 4 parts 2 A-St 195 10000 5 parts 3 A-St 200 5000 5 parts 4 A-St 200 7000 4 parts 5 A-St 200 7500 5 parts 6 A-St 235 1600. 5 parts 7 A-emulsion 1 4 parts 8 A-emulsion 2 5 parts 9 Polyester 5 parts A-St is a styrene acrylic acid resin A-emulsion 1 is a styrene acrylic acid resin-based emulsion (Nippon Polymer Kogyo: Riocryl PFX03).
02) A-emulsion 2 is a styrene acrylic acid resin-based emulsion (Nippon Polymer Kogyo: Tokuryl S740) Polyester is a water-soluble polyester resin (Zohka Chemical Co., Ltd .: Z-446) , The viscosity of the obtained ink and the average particle size were measured, and the jetting characteristics, the printing state, the water resistance of the recorded matter, the resistance value, etc. when the ink was used were evaluated. . The filterability and the like were evaluated as follows. The results are shown in Table 1. Filterability: Comparison was made by the filtration amount with a membrane filter having a diameter of 90 mm and a pore diameter of 0.45 μ within a fixed time. Viscosity: Measured at 25 ° C. using a vibration type viscometer (VM-1A-L manufactured by Yamaichi Denki Co., Ltd.). Ejection characteristics: Ejection failure of the nozzle during continuous printing is evaluated by the presence or absence of defects on the printed matter. Dispersibility: Change in particle size after the ink was stored at 50 ° C. for 7 days (when the change was 15 nm or more, it was regarded as defective).

[0034]

[Table 1]

[Example 11] Red pigment (POST made by Hoechst
Tarpalm Pink E): 250 parts, sodium chloride:
2500 parts, red pigment dispersant (P- [CH₂NH (CH
₂)_FourN (CH₃) ₂]₃, P is a quinacridone residue) 1
0 parts and polyethylene glycol 300 (Tokyo Kasei
Made: 160 parts stainless steel 1 gallon kneader (Inoue
(Manufactured by Seisakusho) and kneaded for 3 hours. Then this mixture
Pour the product into 2.5 liters of warm water and heat to about 80 ° C.
While stirring with a high speed mixer for about 1 hour, slurry
After forming into a shape, repeat filtration and washing with water 8 times, and add sodium chloride.
Aqueous pigment dispersion with solid content of 50%, excluding lithium and solvent
(A pigment derivative-treated pigment dispersion) was obtained. On the sand mill
Concentrated recording liquid for inkjet recording by dispersing the following raw materials
Was produced.   Red pigment (pigment derivative treated pigment dispersion, solid content 50%) 30 parts   Acrylic resin (John Cryl 62 made by Johnson Polymer                 Solid content 31.0%) 2.0 parts   Dispersant (Kao Emulgen A-90) 1.0 part   Purified water 50.0 parts   Ethylene glycol 3.0 parts After dispersion, it was mixed with: 0.45 μ after mixing
Ink is manufactured by filtering with a membrane filter
It was The viscosity is 1.7 cps, and the average particle size is the same as in Example 1.
When asked, it was 91 nm.   13.5 parts of the above dispersion   Dispersant (Emulgen A-90 manufactured by Kao) 0.2 parts   Copolymer of Synthesis Example 4 (solid content) 4.0 parts   Diethylaminoethanol 0.5 parts   Ethylene glycol 2.0 parts   Sodium omazine (Ohlin) 0.15 parts   Ethylenediamine tetraacetic acid sodium salt 0.02 parts   Sodium thiocyanate 0.4 parts   Purified water 82.51 parts Epson HG5130 cartridge
J, Hewlett-Packard's "thinkjet" cart
Ridge and Hitachi IJ printer cartridges
When I put it in and recorded it, I found that
Was obtained. Adjust the ink bleed by dripping water on each recording surface.
Sufficient water resistance without sticking or bleeding of ink
Had.

Example 12 In place of the crude copper phthalocyanine used in Example 1, 280 parts of a yellow pigment (Hansbrilliant Yellow 9GX manufactured by Hoechst) was used, and a blue pigment dispersant was not used. A treated pigment aqueous dispersion having a solid content of 50% was obtained in the same manner as in. The following raw materials were mixed to prepare an aqueous pigment dispersion recording liquid. Yellow pigment (treated pigment aqueous dispersion having a solid content of 50%) 55 parts Acrylic resin (61J manufactured by Johnson Polymer) 7 parts Dispersant (Emulgen A-90 manufactured by Kao) 4 parts Purified water 56 parts Diethylene glycol monobutyl ether 3 parts N-methyl -2-Pyrrolidone 3 parts 2,4,7,9-Tetramethyl-5-decyne-4,7-diol 1 part Ethylene glycol 1 part Dispersed in a sand mill for 2 hours and then mixed with the following. After mixing, centrifugation was carried out to remove coarse particles, followed by filtration with a 1 μm membrane filter and then with a 0.45 μm membrane filter to prepare a recording liquid. The viscosity was 3.0 cps, and the average particle size was 106 nm as determined in the same manner as in Example 1. Dispersion 13.0 parts Dispersant (Solsperse 27000 manufactured by Zeneca) 0.3 parts Copolymer of Synthesis Example 5 (solid content) 5.0 parts Diethylaminoethanol 0.3 parts Diethylene glycol 22.5 parts Antifungal agent (Zeneca Proxel GXL) 0.15 parts Ethylenediamine tetraacetic acid 0.02 parts Purified water 63.53 parts 2,4,7,9-Tetramethyl-5-decyne-4,7-diol 0.1 parts When the ink was put in a cartridge of HG5130 manufactured by Epson Corp. and recording was performed, a good recorded matter was obtained. I drew water on the recording surface and checked for ink bleeding.
There was no ink bleeding or running out, and it had sufficient water resistance.

Example 13 In place of the crude copper phthalocyanine of Example 1, 280 parts of Rionol Blue KLH-T (manufactured by Toyo Ink Mfg. Co., Ltd.) was used and treated in the same manner as in Example 1 to give a solid content. A 50% treated pigment aqueous dispersion was obtained. The following raw materials were mixed to prepare an aqueous pigment dispersion recording liquid. Blue pigment (acrylic-treated pigment aqueous dispersion having a solid content of 50%) 20 parts Copolymer of Synthesis Example 3 (solid content) 2.8 parts Dispersant (Zeneca Solspers 27000) 4.0 parts Purified water 74.5 parts Ethylene Glycol 6.0 parts Dispersed in a sand mill for 1 hour and then mixed with the following. After mixing, the mixture was filtered through a 1 μm membrane filter and then through a 0.45 μm membrane filter to produce an ink. The viscosity was 3.3 cps, and the average particle size was determined in the same manner as in Example 1 to find that it was 97 nm. Dispersion 13.5 parts Copolymer of Synthesis Example 3 (solid content) 1.8 parts Dispersant (Sollucas 27000 manufactured by Zeneca) 0.2 parts Glycerin 25 parts Antifungal agent (sodium omazine manufactured by Aurin) 0.15 parts Ethylenediamine Tetraacetic acid sodium 0.02 parts Purified water 63.53 parts 2,4,7,9-Tetramethyl-5-decyne-4,7-diol 0.1 parts This ink is a cartridge of HG5130 manufactured by Epson Corporation. When it was placed in a box and recorded, good recorded matter was obtained. I drew water on the recording surface and checked for ink bleeding.
There was no ink bleeding or running out, and it had sufficient water resistance.

When the inks obtained in Examples 1 to 13 were stored at -40 ° C for one week and then spontaneously dissolved, 60 ° C
When stored in a constant temperature bath for 1 month and subjected to a cycle test 3 times (hold at -40 ° C for 7 hours, raise to room temperature over 3 hours, hold at room temperature for 7 hours, and over 3 hours) 50 ° C
Up to 50 ° C for 7 hours, reverse the process to -4
Return to 0 ° C. This cycle is repeated 3 times. ), In each case, the initial viscosity was maintained, the ejection characteristics were stable, and the initial printing characteristics were maintained.

[0039]

According to the present invention, it is possible to obtain a recording liquid which gives a recorded product having good water resistance while using water as a medium. This greatly reduces the restrictions on the recording medium,
In the past, it was expected that the applications of water-based recording liquids, which were often deficient in water resistance due to the influence of the recording medium, would be expanded. Further, even when an ink in which carbon black is dispersed is used as a continuous type, no trouble occurs during printing.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-126780 (JP, A) JP-A-2-276873 (JP, A) JP-A-8-127746 (JP, A) JP-A-2- 276875 (JP, A) JP-A-2-276872 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11/00-11/20

Claims (10)

(57) [Claims] 1. An inkjet ink comprising a colorant dispersed in an aqueous liquid, wherein the aqueous resin has an acid value of 90 to 1 consisting of acrylic acid, styrene and α-methylstyrene.
An ink jet ink characterized by using 15 terpolymers. Wherein the molecular weight of the three component copolymer is from 2000 to 80
The ink-jet ink according to claim 1, wherein the ink is 00. 3. The three terpolymer is per 1 mol of acrylic acid, according to claim 1 or 2, wherein the sum 3-5 moles of styrene and α-methyl styrene is obtained by copolymerizing Inkjet ink. 4. The three-component copolymer is, relative to 1 mol of acrylic acid, styrene 1.7-2.3 mol, and shall have by copolymerizing the α-methylstyrene 1.8-2.2 mol The inkjet ink according to any one of claims 1 to 3 . 5. The three ternary claims 1, characterized in that it comprises a polymer of a neutralizing agent to 4 ink jet ink according to any one. 6. claims 1, characterized by using three terpolymer of 0.5-8% by weight 5-jet ink according to any one. 7. The three terpolymer 0.5-8 parts by weight, the coloring agent 0.5 to 5 parts by weight, containing a fungicide 0.03 parts by weight of water 50 to 95 parts by weight Claim 1 characterized by the above.
7. The inkjet ink according to any one of 6 to 6 . 8. wearing color agent, carbon black, phthalocyanine organic pigments, azo claims 1 to 7 ink jet ink according to any one characterized in that it is selected from the group consisting of organic pigments. 9. The ink jet ink of claims 1, characterized in that filtered through a pore size 0.65μm below the filter 8 according to any one. 10. A viscosity of 0.8 to 15 centipoise (2
The ink jet ink according to any one of claims 1 to 9 , wherein the temperature is 5 ° C.