JPH11323221A - Aqueous ink containing black pigment, ink-jet recording using the same and apparatus for ink-jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous ink containing a black pigment, excellent in issuing stability after the interruption of a printing operation when used for an ink-jet recording, by compounding a specific compound, water and a coloring material comprising a specified self-dispersion type carbon black. SOLUTION: This aqueous ink containing a black pigment is obtained by compounding (A) 0.1-15 wt.% of a coloring material comprising a self-dispersion type carbon black to whose surface one or more hydrophilic groups are bonded directly or through one or more other atomic groups, (B) 1-30 wt.% of a compound of the formula [(n) is 1 or 2; (m) is 0-2] (for example, 3-methyl-1,3- butanediol) and (C) 50-95 wt.% of water. The hydrophilic groups in the component A preferably comprise -COOM [M is H, an alkali metal or (organic) ammonium], -SO3 M, -SO2 NH2 , -PO3 HM, -PO3 M2 , -NH<+> 3 , etc., and the other atomic groups in the component A preferably comprise a 1-12C alkyl, (substituent- containing) phenyl, (substituent-containing) naphthyl, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous black pigment ink, an ink jet recording method, and an ink jet recording apparatus. More specifically, the present invention relates to an aqueous black pigment ink using carbon black as a coloring material suitable for ink jet recording. The present invention relates to an ink jet recording method and an ink jet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, carbon black excellent in fastness and the like has been widely used as a black colorant for printing inks. However, in order to use carbon black as a coloring material for aqueous inks, carbon black must be contained in an aqueous medium. Is required to be stably dispersed. Since carbon black generally has poor dispersibility, a method of adding a dispersant to disperse carbon black in an aqueous medium has been adopted in order to obtain a uniform dispersion system.

On the other hand, when ink is generally used for ink jet recording, it is required that the ink be ejected as stable droplets from fine holes (nozzles) of the ink jet recording head. At the same time, it is necessary that the ink does not solidify due to evaporation of the ink in the nozzle portion of the ink jet recording head. However, when the ink containing the above dispersant is used for ink jet recording, the resin forming the dispersant adheres to the orifice or the like and is difficult to be re-dissolved. Etc. may occur. In addition, since the aqueous pigment ink containing a dispersant is viscous, there have been problems in that when performing continuous ejection and high-speed printing for a long time, ejection becomes unstable or smooth recording becomes difficult.

[0004] In order to solve these problems, JP-A-5-186704 and JP-A-8-3498 disclose the use of a dispersant by introducing a water-soluble group into the surface of carbon. Self-dispersible carbon black that can be stably dispersed without volatilization is volatilized. However, even when a water-based pigment ink using self-dispersion type carbon black without using a dispersant is used as an inkjet recording ink, printing can be paused at a nozzle corresponding to a blank while printing a blank document or image. In such a case, there is a problem that the first ejection at the time of resumption is disturbed or the ejection is not performed.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned conventional problems, and in particular, when used in ink-jet recording, discharge stability after printing is suspended (hereinafter referred to as intermittent discharge stability). The present invention is to provide an aqueous black pigment ink excellent in such a case, an ink jet recording method and an ink jet recording apparatus using such an aqueous black pigment.

[0006]

The aqueous black pigment ink of the present invention comprises a self-dispersible carbon black having at least one hydrophilic group bonded directly or via another atomic group to the surface of the carbon black. It is characterized by containing a coloring material, a compound represented by the following general formula (1), and water.

[0007]

Embedded image (In the formula, n represents an integer of 1 to 2, and m represents an integer of 0 to 2.) In the ink jet recording method of the present invention, a recording material is provided by giving energy to ink and causing the ink to fly as ink droplets. In the ink jet recording method for performing the above recording, the ink is the above-described aqueous black pigment ink of the present invention.

An ink jet recording apparatus according to the present invention is an ink jet recording apparatus comprising: a recording unit having at least an ink storage section for storing ink and a head section for discharging the ink as ink droplets by the action of thermal energy. Whether the ink is the aqueous black pigment ink of the present invention; or an ink cartridge having at least an ink containing section containing the ink, and a recording head for discharging the ink as ink droplets by the action of thermal energy. Wherein the ink is the above-mentioned aqueous black pigment ink of the present invention.

According to the present invention, there is provided an aqueous black pigment ink particularly excellent in intermittent ejection stability when used for ink jet recording.

[0010]

Next, the present invention will be described in more detail with reference to preferred embodiments.

First, as a coloring material, a self-dispersible carbon black having at least one kind of hydrophilic group bonded to the surface thereof directly or via another atomic group is used. As a result, there is no need for a dispersant for dispersing carbon black as in the conventional ink. The self-dispersion type carbon black used in the present invention includes -SO ₂ NH ₂ , -S
A substituent such as O ₂ NHCOR (R represents an alkyl group having 1 to 12 carbon atoms, a phenyl group which may have a substituent or a naphthyl group which may have a substituent) is bonded to the surface thereof. Nonionic self-dispersible carbon black may be used, but ionic ones are particularly preferable, and anionically charged ones and cationically charged ones are suitable.

The hydrophilic group bonded to the surface of the anionic charged carbon black includes, for example, -CO
_{OM, -SO 3 M, -PO 3} HM, -PO 3 M 2 ( where, M in the formula is a hydrogen atom, an alkali metal,. An ammonium or organic ammonium), and the like.
In the present invention, among these, particularly -COOM,-
It is preferable to use one in which SO ₃ M is bonded to the surface of carbon black.

The "M" in the hydrophilic group may be, for example, lithium, sodium, potassium or the like as an alkali metal, and may be mono to trimethyl ammonium, mono to triethyl ammonium, mono to triethyl ammonium as organic ammonium. Trimethanol ammonium. As a method of obtaining anionic charged carbon black, there is a method of introducing -COONa on the surface of carbon black. Specifically, there is a method of oxidizing carbon black with sodium hypochlorite. Of course, the present invention is not limited to these.

The hydrophilic group bonded to the surface of the cationically charged carbon black is, for example, preferably a quaternary ammonium group, and more preferably, the following quaternary ammonium groups. In the above, one in which any of these is bonded to the surface of carbon black is preferably used as a coloring material.

[0015]

Embedded image As a method for producing a cationic self-dispersible carbon black having a hydrophilic group as described above, for example, there is a method of bonding an N-ethylethylpyridyl group having the structure shown below. Specifically, carbon black 3
-Amino-N-ethylpyridinium bromide. Of course, the present invention is not limited to this.

[0016]

Embedded imageFurther, in the present invention, the hydrophilic group as described above is used.
Binds to the surface of carbon black via other groups
It may be. Other atomic groups include, for example, carbon,
An alkyl group having 1 to 12 atoms,
A phenyl group or a naphthyl group which may have a substituent;
Can be The hydrophilic group described above is carbohydrated through another atomic group.
Specific examples of the case of bonding to the surface of black
For example, -CH_Two COOM, -C_Two H_Four COOM, -C_Three 
H₆ COOM, -CH_Two SO_Three M, -C_Two H_Four SO_Four 
M, -C_Three H₆ SO_Four M, -PhSO_Three M, -C_Five H_Ten
NH _Three ⁺Etc., but of course, the present invention is limited to these.
It is not done.

The self-dispersion type carbon black used in the aqueous black pigment ink of the present invention is cationically or anionically charged by a hydrophilic group on the surface of the carbon black, and has water dispersibility by repulsion of ions. Further, the hydrophilicity is also improved by the hydrophilic group. Therefore, an aqueous pigment ink that is stably dispersed in an aqueous medium without increasing the particle size or viscosity of the pigment even after being left for a long time is obtained.

Further, in the present invention, the above-mentioned self-dispersion type carbon black is not limited to one kind, and the color tone may be adjusted by using a mixture of two or more kinds. The amount of the self-dispersible carbon black in the pigment ink of the present invention is preferably 0.1 to 15% by weight, more preferably 1 to 15% by weight, based on the total weight of the ink.
In the range of 10 to 10% by weight. Further, the color tone of the ink may be adjusted by using a dye in addition to the self-dispersion type carbon black.

The black pigment ink of the present invention is characterized in that the compound of the general formula (1) is contained together with the above-mentioned self-dispersible carbon black used as a coloring material.
The present inventors have conducted intensive studies to improve the intermittent ejection stability of an aqueous black pigment ink containing self-dispersed carbon black. As a result, if the compound represented by the general formula (1) is used, the intermittent ejection stability can be improved. Has been found to be significantly improved.

The compound of the general formula (1) used in the aqueous black pigment ink of the present invention is as follows.

[0021]

Embedded image (Wherein, n represents an integer of 1 to 2 and m represents an integer of 0 to 2.) The general formula (1) contained in the aqueous black pigment ink of the present invention.
Specific examples of the compound include, for example, 3-methyl-
1,3-Butanediol (common name isoprene glycol or MBD) and 2,2-dimethyl-1,3-propanediol (common name neopentyl glycol) are used.
The content of the compound of the general formula (1) is preferably in the range of 1 to 30% by weight, more preferably 1 to 15% by weight, based on the total amount of the aqueous black pigment ink.

As the water to be contained in the aqueous black pigment ink of the present invention, it is desirable to use deionized water instead of general water containing various ions. The water content is preferably in the range of 50 to 95% by weight based on the total amount of the aqueous black pigment ink.

The aqueous black pigment ink of the present invention may contain the above-mentioned self-dispersible carbon black, the compound represented by the general formula (1) and water, and may further contain a water-soluble organic solvent. May be.

Examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol,
C1-C5 alkyl alcohols such as sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and n-pentanol; amides such as dimethylformamide and dimethylacetamide; ketone or keto alcohol such as acetone and diacetone alcohol Ethers such as tetrahydrofuran and dioxane;
Oxyethylene or oxypropylene copolymers such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, trimethylene glycol, triethylene glycol, 1, Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as 2,6-hexanetriol; glycerin; trimethylolethane, trimethylolpropane; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether , Lower alkyl ethers such as triethylene glycol monomethyl (or ethyl) ether; Lower dialkyl ethers of polyhydric alcohols such as glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; sulfolane, N-methyl-2 -Pyrrolidone, 2
-Pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like.

The content of the above-mentioned water-soluble organic solvent contained in the ink used in the present invention is preferably in the range of 1 to 49% by weight, more preferably 2 to 30% by weight of the total weight. I do. Further, the water-soluble organic solvent as described above,
It can be used alone or as a mixture. In addition,
The amount of water in the ink used in the present invention is from 50 to
It is about 98% by weight, preferably about 60 to 90% by weight.

In addition to the above components, the ink used in the present invention may further comprise a viscosity adjuster, a preservative, an antioxidant, a pH adjuster, an antifoaming agent, and ethylene oxide addition of acetylene glycol as required. An additive such as a nonionic surfactant such as a substance may be appropriately blended.

The preferable range of the physical properties of the ink used in the present invention is around 25 ° C., the pH is preferably 3 to 12, more preferably 4 to 10, and the surface tension is preferably 10 to 60 dyn / cm. More preferably 20 to
50 dyn / cm, viscosity is preferably 1 to 30 cps,
More preferably, it is in the range of 1 to 10 cps.

The aqueous black pigment ink of the present invention is particularly effective when used in ink jet recording. Ink jet recording methods include a recording method of ejecting droplets by applying mechanical energy to ink, and an ink jet recording method of ejecting droplets by foaming the ink by applying thermal energy to the ink. The aqueous black pigment ink of the present invention is particularly suitable for the method.

Next, an example of the ink jet recording apparatus of the present invention suitable for performing recording using the above-described aqueous black pigment ink of the present invention will be described below.

First, FIGS. 1 and 2 show an example of a head configuration which is a main part of an ink jet recording apparatus utilizing thermal energy.

FIG. 1 is a sectional view of the head 13 along the ink flow path, and FIG. 2 is a sectional view taken along the line AB in FIG. The head 13 is obtained by bonding a heating element substrate 15 to a glass, ceramic, silicon or plastic plate having a flow path (nozzle) 14 through which ink passes. The heating element substrate 15 includes a protective layer 16 formed of silicon oxide, silicon nitride, silicon carbide, or the like, and electrodes 17-1 and 17 formed of aluminum, gold, an aluminum-copper alloy, or the like.
-2, a heating resistor layer 18 formed of a high melting point material such as HfB ₂ , TaN, TaAl, a heat storage layer 19 formed of thermally oxidized silicon, aluminum oxide, or the like, and a heat radiation property of silicon, aluminum, aluminum nitride, or the like It comprises a substrate 20 formed of a good material.

The electrodes 17-1 and 17- of the head 13
When a pulse-like electric signal is applied to the area 2, the area indicated by n on the heating element substrate 15 rapidly generates heat, bubbles are generated in the ink 21 in contact with the surface, and the meniscus 23 is protruded by the pressure. , Ink 21 is discharged through the nozzle 14 of the head, and the ink droplet 24 is discharged from the discharge orifice 22.
And fly toward the recording material 25.

FIG. 3 is an external view of an example of a multi-head in which many heads shown in FIG. 1 are arranged. This multi-head includes a glass plate 27 having a multi-nozzle 26,
Is formed by bonding a heating head 28 similar to that described in the above.

FIG. 4 shows an example of an ink jet recording apparatus incorporating this head.

In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member to form a cantilever.
The blade 61 is arranged at a position adjacent to the recording area of the recording head 65, and in the case of this example, the recording head 65
Is held in a protruding form in the movement path of the camera.

A cap 62 is provided at a home position adjacent to the blade 61 and moves in a direction perpendicular to the moving direction of the recording head 65 so as to come into contact with the ink ejection port surface. And a configuration for performing capping. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61, which is held in a form protruding into the movement path of the recording head 65, similarly to the blade 61. The blade 61, the cap 62 and the ink absorber 63 constitute an ejection recovery section 64, and the blade 61
In addition, moisture, dust, and the like are removed from the ejection port surface by the ink absorber 63.

Reference numeral 65 denotes a discharge energy generating means,
A recording head 66 for performing recording by discharging ink onto a recording material facing a discharge port surface having discharge ports, and 66 is a recording head 65
Is a carriage for moving the recording head 65 by mounting the same. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 driven by a motor 68 (not shown). As a result, the carriage 66 can move along the guide shaft 67, and the recording head 65 can move the recording area and the adjacent area.

Reference numeral 51 denotes a paper feed unit for inserting a recording material,
52 is a paper feed roller driven by a motor (not shown). With such a configuration, the recording material is fed to a position facing the discharge port surface 65 of the recording head, and is discharged to a discharge section provided with a discharge roller 53 as recording proceeds.
In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64
Is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. As a result, the ejection openings of the recording head 65 are wiped.

When capping is performed with the cap 62 in contact with the ejection surface of the recording head 65, the cap 62
Moves so as to protrude into the movement path of the recording head.
When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as the position at the time of the wiping described above. As a result, the ejection port surface of the recording head 65 is also wiped during this movement.

The above-described movement of the print head to the home position is performed not only at the end of printing and at the time of ejection recovery, but also at a predetermined interval while the print head moves through the printing area for printing. Position, and the wiping is performed along with the movement.

FIG. 5 is a view showing an example of an ink cartridge containing ink supplied to a recording head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage section storing the supply ink, for example, an ink bag, and a rubber stopper 42 is provided at the tip thereof. By inserting a needle (not shown) into this stopper 42,
The ink in the ink bag 40 can be supplied to the head. 4
Reference numeral 4 denotes an ink absorber for receiving waste ink.

The ink container preferably has a liquid contact surface with the ink formed of polyolefin, particularly polyethylene.

The ink jet recording apparatus used in the present invention is not limited to the one in which the head and the ink cartridge are separated as described above, but may be the one in which they are integrated as shown in FIG. It is preferably used. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink container containing ink, for example, an ink absorber is stored, and the ink in the ink absorber is transferred from a head unit 71 having a plurality of orifices. It is configured to be ejected as ink droplets. It is preferable for the present invention to use polyurethane as the material of the ink absorber.

Further, a structure may be employed in which the ink storage section is an ink bag in which a spring or the like is provided inside without using an ink absorber.

Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The recording unit 70 is used in place of the recording head 65 shown in FIG. 4, and is detachable from the carriage 66.

Next, as a preferred example of an ink jet recording apparatus utilizing mechanical energy, a nozzle forming substrate having a plurality of nozzles and a pressure generating element made of a piezoelectric material and a conductive material disposed opposite to the nozzles are used. An on-demand ink jet recording head that includes ink filling around the pressure generating element, displaces the pressure generating element by an applied voltage, and discharges small droplets of ink from a nozzle can be given. FIG. 7 shows an example of a configuration of a recording head which is a main part of the recording apparatus.

The head includes an ink passage 80 communicating with an ink chamber (not shown), an orifice plate 81 for discharging ink droplets of a desired volume, a vibration plate 82 for directly applying pressure to ink, and a A piezoelectric element 83 joined to the vibration plate 82 and displaced by an electric signal, and a substrate 84 for pointing and fixing the orifice plate 81, the vibration plate 82, and the like.
It is composed of

In FIG. 7, the ink flow path 80 is formed of a photosensitive resin or the like, and the orifice plate 81 is formed with a discharge port 85 formed by electroforming or pressing a metal such as stainless steel or nickel. The plate 82 is formed of a metal film such as stainless steel, nickel, titanium or the like and a high elastic resin film, and the piezoelectric element 83 is formed of a dielectric material such as barium titanate or PZT.

In the recording head having the above structure, a pulse voltage is applied to the piezoelectric element 83 to generate a strain stress,
The energy deforms the vibration plate bonded to the piezoelectric element 83, vertically pressurizes the ink in the ink flow path 80, and applies ink droplets (not shown) to the ejection openings 85
It operates so as to perform recording by discharging more.

Such a recording head is used by being incorporated in an ink jet recording apparatus similar to that shown in FIG. The detailed operation of the ink jet recording apparatus may be the same as that described above.

[0051]

Next, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

Example 1 (Preparation of Pigment Dispersion 1) 300 g of commercially available acidic carbon black "MA-77" (pH 3, manufactured by Mitsubishi Chemical Corporation)
Was thoroughly mixed with 1,000 ml of water, and 450 g of sodium hypochlorite (effective chlorine concentration: 12%) was added dropwise thereto.
The mixture was stirred at 100 to 105 ° C for 10 hours. The obtained slurry was applied to Toyo Filter Paper No. 2 (manufactured by Advantis), and the pigment particles were sufficiently washed with water. This pigment wet cake was redispersed in 3,000 ml of water, and the conductivity was 0.2 μs.
It was desalted with a reverse osmosis membrane until. Further, the pigment dispersion (pH
= 8 to 10) were concentrated to a pigment concentration of 10% by weight. According to the method described above, Pigment Dispersion Liquid 1 in which anionic self-dispersible carbon black in which a -COONa group was bonded to the surface of carbon black was dispersed was obtained.

Preparation of Ink of Example 1 The following components were mixed, sufficiently stirred and dissolved, and then filtered under pressure through a micro filter having a pore size of 3.0 μm (manufactured by Fuji Photo Film Co., Ltd.). 1 ink was prepared.

-30 parts of pigment dispersion liquid-10 parts of 3-methyl-1,3-butanediol-60 parts of water Examples 2 to 6 The following components were mixed, sufficiently stirred and dissolved, and then pore size was obtained. The inks of Examples 2 to 5 were prepared by filtration under pressure using a 3.0 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.).

30 parts of ink composition / pigment dispersion 1 of Example 2 10 parts of 2,2-dimethyl-1,3-propanediol 60 parts of water 30 parts of ink composition / pigment dispersion 1 of Example 3 -Methyl-1,3-butanediol 10 parts-Thiodiglycol 5 parts-Isopropyl alcohol 3 parts-Water 52 parts Ink composition of Example 4 -Pigment dispersion 1 30 parts-3-methyl-1,3-butanediol 7 Part: glycerin 7 parts: acetylene glycol ethylene oxide adduct (trade name: acetylenol EH, manufactured by Kawaken Fine Chemical) 0.15 part ・ water 55.85 parts Ink composition of Example 5・ pigment dispersion liquid 130 parts ・ 2 2-Dimethyl-1,3-propanediol 5 parts ・ Diethylene glycol 5 parts ・ Glycerin 5 parts ・ Acetylene glycol ethylene oxide Adduct: DB (Preparation Pigment Dispersion 2) surface area (trade name Acetylenol EH, manufactured by Kawaken Fine Chemicals) 0.15 parts Water 54.85 parts Example 6 at 230 m ² / g
10 g of carbon black having a P oil absorption of 70 m ² / g;
3-amino-N-ethylpyridinium bromide 3.0
6 g and water 72 g, and then nitric acid 1.6 was added.
2 g was added dropwise and the mixture was stirred at 70 ° C. After a few minutes, a solution of 1.07 g of sodium nitrite in 5 g of water is added,
The mixture was further stirred for 1 hour. The obtained slurry is applied to Toyo
o. 2 (manufactured by Advantis), and the pigment particles were sufficiently washed with water. This pigment wet cake is added to water 3,0
It was redispersed to 00 ml and desalted with a reverse osmosis membrane until the electric conductivity was 0.2 μs. Further, this pigment dispersion was concentrated to a pigment concentration of 10% by weight. By the above method, a pigment dispersion liquid 2 in which a cationic self-dispersible carbon black having the following hydrophilic groups bonded to the surface of the carbon black was dispersed was obtained.

[0056]

Embedded image Preparation of Ink of Example 6 The following components were mixed, sufficiently stirred and dissolved, and then filtered under pressure with a micro filter having a pore size of 3.0 μm (manufactured by Fuji Photo Film Co., Ltd.) to prepare Ink 6. .

-30 parts of pigment dispersion liquid-10 parts of 3-methyl-1,3-butanediol-60 parts of water Examples 7 to 10 The following components were mixed, sufficiently stirred and dissolved, and then the pore size was changed. The solution was subjected to pressure filtration with a 3.0 μm micro filter (manufactured by Fuji Photo Film Co., Ltd.), and filtered through Examples 7 to 10.
Were adjusted respectively.

30 parts of ink composition / pigment dispersion 2 of Example 7 10 parts of 2,2-dimethyl-1,3-propanediol 60 parts of water 30 parts of ink composition / pigment dispersion 2 of Example 8 -Methyl-1,3-butanediol 10 parts Diethylene glycol 5 parts Isopropyl alcohol 3 parts Water 52 parts Ink composition of Example 9 Pigment dispersion 2 30 parts 3-Methyl-1,3-butanediol 7 parts Glycerin 7 parts ・ Acetylene glycol ethylene oxide adduct (trade name: acetylenol EH, manufactured by Kawaken Fine Chemical) 0.15 part ・ Water 55.85 parts Ink composition of Example 10・ Pigment dispersion liquid 2 30 parts ・ 2,2- Dimethyl-1,3-propanediol 5 parts ・ Diethylene glycol 5 parts ・ Glycerin 5 parts ・ Acetylene glycol ethylene oxide Side adduct: After mixing the components shown in (trade name Acetylenol EH, manufactured by Kawaken Fine Chemicals) 0.15 parts Water 54.85 parts Comparative Examples 1 to 8 below were dissolved by sufficiently stirring, pore size 3 The solution was filtered under pressure through a 0.0 μm microfilter (manufactured by Fuji Photo Film Co., Ltd.) and Comparative Examples 1 to 10 were filtered.
Were adjusted respectively.

[0059] Comparative Example 1 Ink composition Pigment dispersion 1 30 parts Water 70 parts Comparative Example 2 Ink composition Pigment dispersion 1 30 parts Thiodiglycol 5 parts Isopropyl alcohol 3 parts Water 62 parts Comparative Example Ink composition of No. 3 / Pigment dispersion liquid 1 30 parts Glycerin 7 parts Acetylene glycol ethylene oxide adduct (trade name: acetylenol EH, manufactured by Kawaken Fine Chemical) 0.15 parts Water 62.85 parts Ink composition of Comparative Example 4 -30 parts of pigment dispersion liquid-5 parts of diethylene glycol-5 parts of glycerin-0.15 parts of acetylene glycol ethylene oxide adduct (trade name: acetylenol EH, manufactured by Kawaken Fine Chemical)-59.85 parts of water Ink composition of Comparative Example 5 pigment dispersion 2 30 parts ink composition of water 70 parts Comparative example 6 pigment dispersion 2 30 parts Ethylene glycol 5 parts Isopropyl alcohol 3 parts Ink composition Pigment dispersion liquid water 62 parts Comparative Example 7 2 30 parts Glycerin 7 parts Acetylene glycol ethylene oxide adduct (trade name: Acetylenol EH, manufactured by Kawaken Fine Chemicals) 0 .15 parts ・ Water 62.85 parts Ink composition of Comparative Example 8・ Pigment dispersion 2 30 parts ・ Diethylene glycol 5 parts ・ Glycerin 5 parts ・ Acetylene glycol ethylene oxide adduct (trade name: acetylenol EH, manufactured by Kawaken Fine Chemical) 0 .15 parts ・ Water 59.85 parts [Evaluation] Using the inks of Examples 1 to 10 and Comparative Examples 1 to 8, applying heat energy according to the recording signal to the ink to discharge the ink. Ink jet recording apparatus B having demand type multi recording head
The following evaluation was performed using C-4200 (manufactured by Canon Inc.). Table 1 shows the results.・ Stability of intermittent discharge 10 seconds continuous discharge → constant time pause → continuous discharge When the above intermittent operation is performed, whether or not disturbance in the discharge direction occurs at the first discharge is determined by the pause time. The stability of intermittent ejection was measured by changing the time stepwise, and evaluated according to the following criteria. The evaluation was performed at an environmental temperature of 5 ° C. and a humidity of 10%.

A: Stable ejection even after a pause of 31 seconds or more.

Δ: Stable ejection even after pause for 21 to 30 seconds.

C: Discharge was stable only during a rest time of 20 seconds or less.

[0063]

[Table 1]

[0064]

As described above, according to the present invention,
Aqueous black pigment ink with excellent ejection stability after printing pause,
An inkjet recording method and an inkjet recording apparatus using such an aqueous black pigment ink are provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view along an ink flow path showing an example of a head of an ink jet recording apparatus.

FIG. 2 is a sectional view of the head shown in FIG. 1 taken along line AB.

FIG. 3 is an external perspective view of a head obtained by multiplying the head shown in FIG. 1;

FIG. 4 is a schematic perspective view illustrating an example of an ink jet recording apparatus.

FIG. 5 is a longitudinal sectional view illustrating an example of an ink cartridge.

FIG. 6 is a schematic perspective view illustrating an example of a recording unit.

FIG. 7 is a schematic cross-sectional view illustrating an example of a configuration of an ink jet recording head using mechanical energy.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 Head 14 Ink groove 15 Heating head 16 Protective film 17-1, 17-2 Electrode 18 Heating resistor layer 19 Heat storage layer 20 Substrate 21 Ink 22 Discharge orifice (fine hole) 23 Meniscus 24 Ink droplet 25 Recording material 26 Multi Groove 27 Glass plate 28 Heating head 40 Ink bag 42 Plug 44 Ink absorber 45 Ink cartridge 51 Paper feed unit 52 Paper feed roller 53 Discharge roller 61 Blade 62 Cap 63 Ink absorber 64 Discharge recovery unit 65 Recording head 66 Carriage 67 Guide Shaft 68 Motor 69 Belt 70 Recording unit 71 Head unit 72 Atmospheric communication port 80 Ink channel 81 Orifice plate 82 Vibrating plate 83 Piezoelectric element 84 Substrate 85 Discharge port

Claims (13)

[Claims] 1. The method according to claim 1, wherein the carbon black has at least one
It is characterized by containing a coloring material composed of a self-dispersible carbon black in which various kinds of hydrophilic groups are bonded directly or via another atomic group, a compound represented by the following general formula (1), and water. Aqueous black pigment ink. Embedded image (In the formula, n represents an integer of 1 to 2, and m represents an integer of 0 to 2.) 2. The hydrophilic group is at least one selected from the following hydrophilic groups, and the other atomic group is an alkyl group having 1 to 12 carbon atoms and a phenyl group which may have a substituent. The aqueous black pigment ink according to claim 1, which is a naphthyl group which may have a substituent. Embedded image (Wherein, M represents a hydrogen atom, an alkali metal, ammonium or organic ammonium, and R represents 1 carbon atom.
To 12 represent a kill group, a phenyl group having a substituent or a naphthyl group which may have a substituent. ) 3. The content of the compound represented by the general formula (1) is 1 to 30% by weight based on the total amount of the aqueous black pigment ink.
The aqueous black pigment ink according to claim 1 or 2, wherein 4. A compound represented by the general formula (1):
The aqueous black pigment ink according to any one of claims 1 to 3, wherein the aqueous black pigment ink is methyl-1,3-butanediol. 5. The compound represented by the general formula (1) is 2,
The aqueous black pigment ink according to any one of claims 1 to 3, wherein the aqueous black pigment ink is 2-dimethyl-1,3-propanediol. 6. An ink jet recording method for recording on a recording material by applying energy to the ink and causing the ink to fly as ink droplets, wherein the ink is any one of claims 1 to 5. An ink-jet recording method, characterized in that it is an aqueous black pigment ink. 7. The energy is heat energy.
The inkjet recording method according to claim 6. 8. The ink jet recording method according to claim 6, wherein the energy is mechanical energy. 9. A recording unit comprising at least an ink containing section containing at least ink and a head section for ejecting the ink as ink droplets, wherein the ink is any one of claims 1 to 5. A recording unit, which is the aqueous black pigment ink described in the above. 10. An ink cartridge provided with an ink storage section for storing ink, wherein the ink is provided.
An ink cartridge comprising the aqueous black pigment ink according to claim 5. 11. An ink jet recording apparatus comprising: a recording unit having at least an ink container containing at least ink and a head for discharging the ink as ink droplets by the action of thermal energy. An ink jet recording apparatus comprising the aqueous black pigment ink according to any one of claims 1 to 5. 12. An ink jet recording apparatus, comprising: an ink cartridge having at least an ink container containing at least ink; and a recording head for ejecting the ink as ink droplets by the action of thermal energy. An ink jet recording apparatus comprising the aqueous black pigment ink according to any one of claims 1 to 5. 13. The ink jet recording apparatus according to claim 12, further comprising an ink supply unit for supplying the ink contained in the ink cartridge to the recording head unit.