JP2008222981A - Method for producing aqueous pigment dispersion and aqueous pigment ink, recording apparatus using the ink and recorded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aqueous pigment dispersion which combines good productivity and good storage characteristics (specifically, no change in characteristics during storage at a high temperature), which is the problem involved in conventional beads of a small diameter. <P>SOLUTION: A method for producing an aqueous pigment dispersion comprises the main dispersion step of dispersing an aqueous liquid mixed with a pigment composition comprising a pigment, a dispersant and water with the use of zirconia beads having a diameter of not less than 0.01 mm to not more than 0.5 mm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an aqueous pigment dispersion for an ink jet recording method and apparatus, and an aqueous pigment ink using the aqueous pigment dispersion.

The inkjet recording method is easy to make full color because the process is simpler than other recording methods, and there is an advantage that a high-resolution image can be obtained even with an apparatus having a simple configuration.
As ink-jet inks, dye-based inks in which various water-soluble dyes are dissolved in water or a mixture of water and an organic solvent are used. Dye-based inks have excellent color tone, but are resistant to light. There was a disadvantage that was inferior in nature. On the other hand, pigment-based inks in which carbon black and various organic pigments are dispersed are actively studied because they are superior in light resistance compared to dye-based inks.

  However, unlike pigments, pigments are insoluble in water, so it is important to stably disperse pigments in water in the form of fine particles, but this dispersion is not always easy. In particular, when the temperature condition for the pigment dispersion system changes, the adsorption equilibrium of the pigment of the dispersant is lost, which affects the interaction between the pigment particles, and changes in physical properties and / or a large amount of aggregated foreign matter is generated during long-term storage. There are many things. Such changes in physical properties (particularly, changes in viscosity) and / or generation of a large amount of aggregated foreign matters are fatal for ink for inkjet printers. This is because a change in characteristics in the head and / or clogging of the discharge nozzles occur, so that proper printing becomes impossible.

Pigment dispersion is an operation in which a pigment existing as an aggregate is ground or pulverized to primary particles or a state close to primary particles. A general dispersion method of a pigment is a method in which a pigment and a dispersant are dispersed in a dispersion medium. The mixed pigment dispersion is ground or dispersed by combining a dispersing device such as a ball mill or a sand mill with a dispersion medium. As a dispersion medium, beads made of a material such as glass, iron, ceramics and the like with a diameter of several mm to 1 mm are used. By reducing the bead diameter, the number of beads per unit volume increases geometrically, the number of collisions between the pigment and the beads increases dramatically, and the fine particles of the pigment can be dispersed.
However, if the bead diameter becomes too small, the mass per bead becomes small, and the impact force against the pigment becomes much weaker when colliding with the pigment, and it takes a long time to disperse the pigment, or the fine particles of the pigment. Dispersion may not be possible. Furthermore, the beads and the pigment dispersion mixture cannot be separated inside the disperser. For this reason, conventionally, when the pigment is dispersed in the form of fine particles, beads having a diameter of 0.2 mm to 1.0 mm are used.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-240027) discloses a manufacturing method in which microbeads having a diameter of 0.02 mm or more and less than 0.2 mm are used and dispersed, and Patent Document 2 (Japanese Patent Application Laid-Open No. 2006-7128). (Patent Publication) describes a pigment dispersion system using an annular type dispersing machine, Patent Document 3 (Japanese Patent Laid-Open No. 2000-44856) discloses a manufacturing method that defines the filling rate and peripheral speed of ceramic beads, and Patent Document 4 (Special No. 2006-188626 has proposed a manufacturing method in which the solid content concentration of the slurry is 10 to 40% by mass and the bead diameter and peripheral speed are defined.
However, there has been a problem that the storage stability of the aqueous pigment dispersion obtained by these methods is remarkably lowered or the productivity of the aqueous pigment dispersion is lowered.

JP 2005-240027 A JP 2006-7128 A JP 2000-44856 A JP 2006-188626 A

  An object of the present invention is to achieve both the productivity and storage stability of an aqueous pigment dispersion, which is a problem when using small-diameter beads (specifically, no change in properties during high-temperature storage).

The above-described problems are solved by the present invention described below. (1) “This is a water-based pigment mixed solution containing at least a pigment, a dispersant, and water using zirconia beads having a diameter of 0.01 mm to 0.5 mm. A method for producing a water-based pigment dispersion characterized by having a dispersion step ",
(2) As described in the above item (1), the zirconia beads in the main dispersion step are dispersed under conditions of 50% to 100% and a peripheral speed of 5 m / s to 20 m / S. Manufacturing method of water-based pigment dispersion ",
(3) “The method for producing an aqueous pigment dispersion according to (1) or (2) above, which includes a pre-dispersing step of dispersing the aqueous pigment mixture without beads”;
(4) The method for producing an aqueous pigment dispersion according to any one of (1) to (3) above, wherein the solid content concentration of the pigment is 10% or more and 40% or less "
(5) The aqueous pigment dispersion according to any one of (1) to (4), wherein the average particle diameter of the pigment after the main dispersion step is 150 nm or less Production method",
(6) "The pigment is CI pigment black 7, CI pigment red 122, CI pigment violet 19, aluminum phthalocyanine, CI pigment blue 15: 3, CI pigment. Blue 15: 6, CI Pigment Yellow 74, CI Pigment Yellow 128, CI Pigment Yellow 138, or a mixture of two or more thereof The method for producing an aqueous pigment dispersion according to any one of (1) to (5), ”
(7) "A method for producing an aqueous pigment dispersion according to any one of (1) to (6) above, wherein a surfactant is used as the dispersant",
(8) The water-based pigment dispersion according to any one of (1) to (7), wherein the weight reference of the dispersant is 0.1 or more and 2 or less with respect to the pigment 1 Manufacturing method ",
(9) “The aqueous pigment according to any one of (1) to (8) above, wherein at least one of the compounds represented by the following general formula (1) is used as the dispersant: A method for producing the dispersion;

（式中、Ｒは炭素数１〜２０のアルキル基、アリル基、アラルキル基を表わし、１は０〜７の整数を表わし、ｎは２０〜２００の整数を表わす。）」、
（１０）「前記分散剤がＰＯＥ（ｎ＝４０）βナフチルエーテルであることを特徴とする前記第（９）項に記載の水系顔料分散体の製造方法」、
（１１）「前記本分散工程を経た後の水系顔料分散体を加熱処理する工程を更に含むことを特徴とする前記第（１）項乃至第（１０）項のいずれかに記載の水系顔料分散体の製造方法」、
（１２）「前記第（１）項乃至第（１１）項のいずれかに記載の水系顔料分散体の製造方法で製造されたことを特徴とする水系顔料分散体」、
（１３）「前記第（１２）項に記載の水系顔料分散体を使用することを特徴とする水系顔料インク」、
（１４）「前記第（１３）項に記載の水系顔料インクを収容したことを特徴とするインクカートリッジ」、
（１５）「前記第（１３）項に記載の水系顔料インクを吐出させて記録を行なう方式のヘッドを備えたことを特徴とするインクジェット記録装置」、
（１６）「前記第（１５）項に記載のインクジェット記録装置を用いて印字することを特徴とする画像形成方法」、
（１７）「前記第（１６）項に記載の画像形成方法で印字されたことを特徴とする画像形成物」、
（１８）「画像支持体が紙であることを特徴とする前記第（１７）項に記載の画像形成物」。

(Wherein R represents an alkyl group having 1 to 20 carbon atoms, an allyl group or an aralkyl group, 1 represents an integer of 0 to 7, and n represents an integer of 20 to 200). "
(10) “The method for producing an aqueous pigment dispersion according to (9) above, wherein the dispersant is POE (n = 40) β-naphthyl ether”,
(11) The aqueous pigment dispersion according to any one of (1) to (10), further including a step of heat-treating the aqueous pigment dispersion after the main dispersion step. Body manufacturing method ",
(12) “Aqueous pigment dispersion produced by the method for producing an aqueous pigment dispersion according to any one of (1) to (11)”,
(13) "Aqueous pigment ink using the aqueous pigment dispersion according to item (12)",
(14) "Ink cartridge characterized by containing the water-based pigment ink according to item (13)",
(15) “Inkjet recording apparatus comprising a head for recording by discharging the water-based pigment ink according to item (13)”,
(16) "Image forming method characterized by printing using the ink jet recording apparatus according to item (15)",
(17) "Image formed product printed by the image forming method according to item (16)",
(18) “The image-formed product according to item (17), wherein the image support is paper”.

  According to the method for producing an aqueous pigment dispersion of the present invention, it is possible to provide an aqueous pigment dispersion having both productivity and storage stability.

Hereinafter, embodiments for carrying out the present invention will be described in detail.
[Pigment]
Examples of the pigment in the present invention include carbon black produced by a furnace method or a channel method.
Examples of magenta pigments include Pigment Red 5, Pigment Red 7, Pigment Red 12, Pigment Red 48 (Ca), Pigment Red 48 (Mn), Pigment Red 57 (Ca), Pigment Red 57: 1, Pigment Red 112, and Pigment Red. 122, pigment red 123, pigment red 168, pigment red 184, pigment red 202, pigment violet 19, and the like.
Examples of cyan pigments include Pigment Blue 1, Pigment Blue 2, Pigment Blue 3, Pigment Blue 15, Pigment Blue 15: 3, Pigment Blue 15: 4, Pigment Blue 16, Pigment Blue 22, Pigment Blue 60, Bat Blue 4, Bat Blue 60 etc. are mentioned.
Examples of the yellow pigment include Pigment Yellow 1, Pigment Yellow 2, Pigment Yellow 3, Pigment Yellow 12, Pigment Yellow 13, Pigment Yellow 14, Pigment Yellow 16, Pigment Yellow 17, Pigment Yellow 73, Pigment Yellow 74, Pigment Yellow 75, Pigment Yellow 83, Pigment Yellow 93, Pigment Yellow 95, Pigment Yellow 97, Pigment Yellow 98, Pigment Yellow 114, Pigment Yellow 120, Pigment Yellow 128, Pigment Yellow 129, Pigment Yellow 138, Pigment Yellow 150, Pigment Yellow 151, Pigment Yellow 154 Pigment Yellow 155, Pigment Yellow 180, etc. It is.
From the point of balance of color tone and light resistance, C.I. I. Pigment black 7, C.I. I. Pigment red 122, C.I. I. Pigment violet 19, aluminum phthalocyanine, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 6, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 128, C.I. I. One or a mixture of two or more selected from any of CI Pigment Yellow 138 can be preferably used. The concentration of the pigment in the pigment dispersion in the pigment ink is preferably 0.1 to 50% and 0.1 to 20%, respectively. More preferably, 0.1 to 30% and 0.1 to 10% are preferable, respectively.

[Dispersant]
As the dispersant used in the present invention, a surfactant can be used (or one that satisfies the property of a polymer resin), and from the viewpoint of the initial viscosity of the dispersion and ink, the following general formula (1) Of which POE (n = 40) β naphthyl ether is most preferably used.

（式中、Ｒは炭素数１〜２０のアルキル基、アリル基、アラルキル基を表わし、１は０〜７の整数を表わし、ｎは２０〜２００の整数を表わす。）

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms, an allyl group, or an aralkyl group, 1 represents an integer of 0 to 7, and n represents an integer of 20 to 200.)

  The ink composition of the present invention preferably contains a wetting agent, and the wetting agent preferably has a boiling point of 180 ° C. or higher. When the humectant is contained in the water-based pigment ink, the water retention and wettability of the ink composition can be ensured. There is no increase and excellent storage stability can be realized. Also, an ink for ink jet recording can be realized that maintains the fluidity of the dried material for a long time even when left open at the nozzle tip of an ink jet printer. Furthermore, nozzle clogging does not occur during printing or when restarting after printing interruption, and high ejection stability can be obtained.

Examples of the water-based pigment ink used in the present invention include, but are not limited to, the following.
For example, ethylene glycol, diethylene glycol 1.3-butyl glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, glycerin, 1,2,6-hexanetriol Polyhydric alcohols such as 2-ethyl-1,3-hexanediol, ethyl 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether , Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Polyhydric alcohol aryl ethers such as alcohol alkyl ethers, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether; 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3 Nitrogen-containing heterocyclic compounds such as dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone; amides such as formamide, N-methylformamide, N, N-dimethylformamide; monoethanolamine, diethanolamine, triethanolamine, mono Examples thereof include amines such as ethylamine, diethylamine and triethylamine, sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol, propylene carbonate, and ethylene carbonate. These wetting agents can be used alone or in admixture of two or more.
Among the wetting agents, the inclusion of 1.3-butyl glycol, diethylene glycol, triethylene glycol and / or glycerin prevents clogging due to drying of the ink, that is, prevention of poor jetting characteristics due to water evaporation, and coloring of the formed image of the present invention. An excellent effect is obtained in improving the degree.
The amount of these wetting agents added is 0.1 to 50% by weight, preferably 5 to 40% by weight of the ink.

  Preferably, the ink contains 2-ethyl-1,3-hexanediol (EHD) to increase the permeability of the ink and at the same time eliminate the bleeding by keeping the pigment on the surface. A printed image can be obtained. The content of EHD is preferably 0.1% by weight or more and 4.0% by weight or less, more preferably 0.5% by weight or more and 3.0% by weight or less. If it is less than 0.1% by weight, the effect is small, and if it exceeds 4.0% by weight, the solubility itself is low, and the reliability deteriorates.

  Nonionic surfactants used in the present invention include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene glycol ester, polyoxyethylene / polyoxypropylene decyl ether or acetylene surfactant, silicon Nonionic surfactants such as surfactants and fluorosurfactants.

In the present invention, the following surfactants may be used in combination as long as they do not affect the ink characteristics.
Specifically, nonionic surfactants include BT series (Nikko Chemicals) Nonipol series (Sanyo Kasei), D-, P-series (Takemoto Yushi) Surfynol series (Air Products) Olphin series (Nisshin) Chemistry) EMALEX DAPE series (Japan emulsion), silicone surfactants (Toray Dow Corning, etc.), fluorosurfactants (Neos, Sumitomo 3M, Dupont, Daikin), etc.
These surfactants are added to reduce the surface tension of the ink and increase the permeability of the ink to the paper, thereby increasing the dryness of the printed image. The amount of the surfactant added is the surface tension of the ink. Is usually adjusted to 50 mN / m or less, preferably 40 mN / m or less, and the content is preferably 0.1 wt% or more and 10.0 wt% or less, more preferably 1.0 wt% or more. 5.0% by weight or less. If the addition amount of the surfactant is less than 0.1% by weight, the dynamic surface tension is high and the drying property is poor. Conversely, if the addition amount is more than 10.0% by weight, the surfactant is deposited during storage. Occurs.
It is preferable that the hydrophilic group of the nonionic surfactant of the present invention is a polyoxyethylene group. The reason is not clearly understood, but it is preferably a polyoxyethylene group from the viewpoint that the charge on the pigment surface can be suitably maintained and the foaming property of the ink can be reduced.

The emulsion resin that can be used in the present invention is a styrene acrylic resin, an acrylic silicon resin, or a polyurethane resin, and the polyurethane resin is particularly preferable because of its fixability to paper.
When used as a raw material for preparing a pigment ink, or after the preparation of the pigment ink composition of the present invention, it exists as an O / W type emulsion. In the polyurethane resin emulsion, a relatively hydrophilic ordinary polyurethane resin is emulsified using an emulsifier externally, and a functional group that functions as an emulsifier is introduced into the resin itself by means such as copolymerization. Self-emulsifying emulsions. Either can be implemented, but care is required because there is a slight difference in the dispersion stability of the pigment and emulsion particles depending on the combination of the components of the pigment ink composition. In various combinations with pigments and dispersants, it is an anionic self-emulsifying polyurethane emulsion resin that is always excellent in dispersion stability. In this case, the polyurethane resin is preferably a polycarbonate resin rather than a polyester resin in terms of pigment fixing and dispersion stability.

  The heating temperature of the heat treatment of the aqueous pigment dispersion and the aqueous pigment ink of the present invention is 40 to 80 ° C., preferably 50 to 70 ° C., and the heating time is 5 to 168 hours, more preferably 24 to 96 hours. If the heating temperature is lower than 40 ° C., it takes time to stabilize the dispersion, which is insufficient. If the heating temperature exceeds 80 ° C., dispersion breakage occurs.

The method for producing an aqueous pigment dispersion of the present invention includes the present disperser for dispersing an aqueous pigment mixture containing at least a pigment, a dispersant, and water using zirconia beads having a diameter of 0.01 mm to 0.5 mm. It is characterized by this. The zirconia bead diameter is more preferably 0.03 mm or more and 0.3 mm or less. When the zirconia bead diameter is larger than 0.5 mm, the pigment dispersing ability is greatly reduced, and fine dispersion below the target particle diameter is difficult.
The zirconia beads of the present invention are dispersed under the conditions of a filling rate of 50% to 100% and a peripheral speed of 5 m / s to 20 m / S. The filling rate of zirconia beads is preferably 60% or more and 90% or less, and the peripheral speed is 8 m / s or more and 16 m / S or less. In both conditions, the relative speed between the beads and the pigment and the kinetic energy of the beads become too small, and dispersion due to collision or grinding does not proceed effectively. Under high conditions, the kinetic energy of the beads becomes too large, the particle size distribution of the pigment particles becomes broad, the surface of the pigment becomes rougher than necessary, and the dispersion stability decreases.
The disperser of the present invention may be any disperser that can use beads and is not particularly limited. For example, “TORUSMILL” manufactured by Getzmann, “Star Mill” manufactured by Ashizawa, “Visco Mill manufactured by Imex” "Dynomill" by Shinmaru Enterprises, "Diamond Fine Mill" by Mitsubishi Heavy Industries, "Apex Mega" by Kotobuki Giken Kogyo, "Picomill" by Asada Tekko, "OB Beads Mill" by Eurotech, Mitsui Examples include “SC mill” manufactured by Mining Co., Ltd.
The pre-dispersing machine that disperses the aqueous pigment mixture of the present invention in a beadless manner is not particularly limited. For example, “TK Philmix” manufactured by Primex Co., “Artemizer” manufactured by Sugino Machine Co., Ltd., M Technique Co., Ltd. “CLEAR SS5”, “Clearmix W Motion” manufactured by Eurotech, “Cabitron” manufactured by Eurotech, “IKA DR2000” manufactured by Shinmaru Enterprises, and the like.

[Measurement of pigment particles after dispersion]
In addition, although the average particle diameter (D50) in this invention can be measured by a conventional method, it can be measured, for example using the Nikkiso Co., Ltd. particle size analyzer UPA150. Further, the standard deviation of the particle diameter referred to in the present invention can be measured by a conventional method. For example, the measured value sd obtained by measuring using a particle size analyzer UPA150 manufactured by Nikkiso Co., Ltd. is also used. Can be used. The average particle size (D50) and particle size standard deviation can be controlled by the peripheral speed of the rotating part of the disperser, the dispersion time, the dispersion flow rate, and the dispersion temperature when the pigment is dispersed using a disperser.

  Hereinafter, the present invention will be described more specifically based on examples.

<Pigment Dispersion Preparation Example-1 (Example No. 1)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 40) 75 parts Distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.03 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 80% and a peripheral speed of 16 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 70 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-2 (Example No. 2)>
Pigment type β: Pigment blue 15: 3 150 parts (manufactured by Dainichi Seika Kogyo Co., Ltd., cyanine blue A-385)
Compound of general formula (1) (n = 40) 75 parts Distilled water 775 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.10 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 60% and a peripheral speed of 12 m / s) is heat-treated, and is subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 120 nm. A dispersion was obtained.

<Pigment dispersion preparation example-3 (Example No. 3)>
Pigment type γ: Pigment Yellow 74 250 parts (Daiichi Seika Kogyo Co., Ltd., Yellow No. 43)
Compound of general formula (1) (n = 40) 188 parts distilled water 562 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.20 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 70% and a peripheral speed of 8 m / s) is subjected to a heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 20 nm. A dispersion was obtained.

<Pigment dispersion preparation example-4 (Example No. 4)>
Pigment species δ: Pigment Black 7 (Mitsubishi Chemical Corporation, # 45L) 350 parts Compound of general formula (1) (n = 40) 525 parts Distilled water 125 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (ultra apex mill type, Kotobuki Kogyo Co., Ltd., media: 0.30 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 90% and a peripheral speed of 10 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 110 nm A dispersion was obtained.

<Pigment Dispersion Preparation Example-5 (Example No. 5)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 40) 75 parts Distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex mill type, Kotobuki Kogyo Co., Ltd., media: 0.03 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 40% and a peripheral speed of 16 m / s) is subjected to a heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 120 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-6 (Example No. 6)>
Pigment type β: Pigment blue 15: 3 150 parts (manufactured by Dainichi Seika Kogyo Co., Ltd., cyanine blue A-385)
Compound of general formula (I) (n = 40) 75 parts Distilled water 775 parts

<Pigment Dispersion Preparation Example-7 (Example No. 7)>
Pigment type γ: Pigment Yellow 74 250 parts (Daiichi Seika Kogyo Co., Ltd., Yellow No. 43)
Compound of general formula (1) (n = 40) 188 parts distilled water 562 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.20 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 70% and a peripheral speed of 3 m / s) is subjected to heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 120 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-8 (Example No. 8)>
Pigment species δ: Pigment Black 7 (Mitsubishi Chemical Corporation, # 45L) 350 parts Compound of general formula (1) (n = 40) 525 parts Distilled water 125 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.20 mmφ zirconia balls, filled with beads) The liquid obtained by circulating and dispersing for 4 hours at a rate of 90% and a peripheral speed of 22 m / s) is heated and subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 40 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-9 (Example No. 9)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 40) 75 parts Distilled water 625 parts

  The above mixture is not treated with a pre-dispersing machine, and is circulated for 4 hours in the bead mill of the present dispersing machine (Koto Kogyo Co., Ltd., Ultra Apex mill type, media: 0.03 mmφ zirconia balls, bead filling rate 80%, peripheral speed 16 m / s). The dispersion liquid was heat-treated and subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, thereby obtaining an aqueous pigment dispersion having an average particle diameter of 110 nm.

<Pigment Dispersion Preparation Example-10 (Example No. 10)>
Pigment type β: Pigment blue 15: 3 450 parts (manufactured by Dainichi Seika Kogyo Co., Ltd., cyanine blue A-385)
Compound of general formula (1) (n = 40) 225 parts distilled water 325 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.10 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 60% and a peripheral speed of 12 m / s) is heat-treated, and is subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 40 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-11 (Example No. 11)>
Pigment type γ: Pigment Yellow 74 250 parts (Daiichi Seika Kogyo Co., Ltd., Yellow No. 43)
188 parts of water-soluble styrene acrylic resin (HPD-96, manufactured by Johnson Polymer Co., Ltd.)
562 parts distilled water

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.20 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 70% and a peripheral speed of 8 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 90 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-12 (Example No. 12)>
Pigment species δ: Pigment Black 7 (Mitsubishi Chemical Corporation, # 45L) 250 parts Compound of general formula (1) (n = 40) 625 parts Distilled water 125 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (ultra apex mill type, Kotobuki Kogyo Co., Ltd., media: 0.30 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 90% and a peripheral speed of 10 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 90 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-13 (Example No. 13)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 10) 75 parts Distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.03 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 80% and a peripheral speed of 16 m / s) is subjected to a heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 200 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-14 (Example No. 14)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 300) 75 parts distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.03 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 80% and a peripheral speed of 16 m / s) is subjected to a heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 200 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-15 (Example No. 15)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 80) 75 parts Distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.03 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 80% and a peripheral speed of 16 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 110 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-16 (Example No. 16)>
Pigment type β: Pigment blue 15: 3
(Daiichi Seika Kogyo Co., Ltd., Cyanine Blue A-385) 150 parts Compound of general formula (1) (n = 40) 75 parts Distilled water 775 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.10 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 4 hours at a rate of 60% and a peripheral speed of 12 m / s) is subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, and an aqueous system having an average particle diameter of 70 nm. A pigment dispersion was obtained.

<Pigment Dispersion Preparation Example-17 (Comparative Example No. 1)>
Pigment type α: Pigment Red 122 300 parts (Ciba Specialty Chemicals,
Chromophthal JET Magenta DMQ)
Compound of general formula (1) (n = 80) 75 parts Distilled water 625 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the bead mill of this dispersing machine (ultra apex mill type, Kotobuki Kogyo Co., Ltd., media: 0.70 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 12 hours at a rate of 80% and a peripheral speed of 16 m / s) is subjected to heat treatment, centrifugal filtration with a centrifugal separator is performed to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 110 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-18 (Comparative Example No. 2)>
Pigment type β: Pigment blue 15: 3 150 parts (manufactured by Dainichi Seika Kogyo Co., Ltd., cyanine blue A-385)
Compound of general formula (1) (n = 40) 0 part distilled water 775 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the beads mill of this dispersing machine (Ultra Apex Mill type, Kotobuki Kogyo Co., Ltd., media: 0.10 mmφ zirconia balls, filled with beads) The liquid produced by circulating and dispersing for 15 hours at a rate of 60% and a peripheral speed of 12 m / s) is not subjected to heat treatment, but is subjected to centrifugal filtration with a centrifugal separator to remove coarse particles and dust, and an aqueous system having an average particle diameter of 250 nm. A pigment dispersion was obtained.

<Pigment Dispersion Preparation Example-19 (Comparative Example No. 3)>
Pigment type γ: Pigment Yellow 74 250 parts (Daiichi Seika Kogyo Co., Ltd., Yellow No. 43)
Compound of general formula (1) (n = 40) 188 parts distilled water 562 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Fillmix type), the bead mill of this dispersing machine (ultra apex mill type, Kotobuki Kogyo Co., Ltd., media: 1.00 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 10 hours at a rate of 70% and a peripheral speed of 8 m / s) is subjected to heat treatment, centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 90 nm. A dispersion was obtained.

<Pigment Dispersion Preparation Example-20 (Comparative Example No. 4)>
Pigment type δ: Pigment Black 7 (Mitsubishi Chemical Corporation, # 45L) 350 parts Compound of general formula (1) (n = 40) 0 parts Distilled water 650 parts

  After the above mixture was dispersed for 2 hours with a pre-dispersing machine (Primmix TK Philmix type), the bead mill of this dispersing machine (ultra apex mill type, Kotobuki Kogyo Co., Ltd., media: 0.05 mmφ zirconia balls, filled with beads) A liquid obtained by circulating and dispersing for 12 hours at a rate of 90% and a peripheral speed of 10 m / s) is subjected to heat treatment, and centrifugal filtration is performed by a centrifugal separator to remove coarse particles and dust, and an aqueous pigment having an average particle diameter of 190 nm. A dispersion was obtained.

  The discharge property evaluation of the aqueous pigment dispersion is confirmed with an aqueous pigment ink obtained by adding the following ink composition to each aqueous pigment dispersion. The storage stability evaluation of the aqueous pigment dispersion evaluates the aqueous pigment dispersion itself. (Examples Nos. 1 to 16. Comparative examples Nos. 1 to 4)

<Ink prescription>
Pigment dispersion (total pigment concentration 5%) −
Glycerol 7.5 parts Diethylene glycol 22.5 parts 2-ethyl-1,3-hexanediol 3.0 parts 2-pyrrolidone 3.0 parts Polyoxyethylene (3) alkyl (C13) ether sodium acetate
0.45 parts distilled water remaining

The ink formulation is
(1) Glycerin, diethylene glycol (2) EHD
(3) 2-Pyrrolidone, polyoxyethylene (3) alkyl (C13) ether sodium acetate (4) High purity water is added in order, and a solution stirred for 30 minutes is added to the aqueous pigment dispersion. Thereafter, the pH is adjusted (around 7 to 10) and stirred for 30 minutes to prepare an aqueous pigment ink.
These and other specifications are summarized in the following table.

分散剤比率＝分散剤重量÷顔料重量とする。
また、上記表１において、使用顔料種α〜γ、分散剤（１）〜（５）の内容、物性は、以下のとおりである。

Dispersant ratio = dispersant weight ÷ pigment weight.
In Table 1 above, the contents and physical properties of the pigment types α to γ and dispersants (1) to (5) used are as follows.

  Ink Example No. above. 1-16, comparative example No.1. 1 to 4 were filled in a black cartridge of an EPSON EM-930C remodeling machine manufactured by EPSON, and then vacuum degassed, and ejection stability was confirmed using an EPSON EM-930C remodeling machine.

<Evaluation 1: Discharge stability>
As for ejection stability, after printing a printed matter, the printer was left in a 40 ° C. environment for one month with the printer head capped. Whether or not the discharge state of the printer after being left restored to the initial discharge state was evaluated by the following number of cleaning operations.
○: Recovered by one operation.
Δ: Recovered by 2 to 3 operations.
X: No recovery was observed even after three or more operations.

<Evaluation 2: Storage stability of aqueous pigment dispersion>
Each ink was put in a polyethylene container, sealed, stored at 70 ° C. for 3 weeks, and then the particle size, surface tension, and viscosity were measured and evaluated according to the rate of change from the initial physical properties as follows.
○: Within 10% △: Within 30% ×: Over 50%

<Evaluation 3: Evaluation of number of coarse particles of water-based pigment dispersion>
The number of particles of each aqueous dispersion having a particle size of 0.5 μm or more was measured and evaluated as follows.
○: less than 1.0 × 10 ⁷ cells / μL △: 1.0 × 10 ⁷ cells / μL more than 1.0 × 10 ⁸ cells / μL within ×: 1.0 × 10 ⁸ cells / μL more than these evaluation The results are shown in the following table.

Claims (18)

  A method for producing a water-based pigment dispersion, comprising a main dispersion step of dispersing a water-based pigment mixed solution containing at least a pigment, a dispersant, and water using zirconia beads having a diameter of 0.01 mm to 0.5 mm. .   2. The method for producing an aqueous pigment dispersion according to claim 1, wherein the dispersion is performed under the conditions of a filling rate of 50% to 100% and a peripheral speed of 5 m / s to 20 m / S in the main dispersion step. .   The method for producing an aqueous pigment dispersion according to claim 1, further comprising a pre-dispersing step of dispersing the aqueous pigment mixed liquid without beads.   The method for producing an aqueous pigment dispersion according to any one of claims 1 to 3, wherein a solid content concentration of the pigment is 10% or more and 40% or less.   The method for producing an aqueous pigment dispersion according to any one of claims 1 to 4, wherein the average particle size of the pigment after the main dispersion step is 150 nm or less.   The pigment is C.I. I. Pigment black 7, C.I. I. Pigment red 122, C.I. I. Pigment violet 19, aluminum phthalocyanine, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 6, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 128, C.I. I. 6. The method for producing an aqueous pigment dispersion according to claim 1, wherein the water-based pigment dispersion is one kind selected from any one of Pigment Yellow 138, or a mixture of two or more kinds.   The method for producing an aqueous pigment dispersion according to claim 1, wherein a surfactant is used as the dispersant.   The method for producing an aqueous pigment dispersion according to any one of claims 1 to 7, wherein a weight basis of the dispersant is 0.1 or more and 2 or less with respect to the pigment 1. The method for producing an aqueous pigment dispersion according to any one of claims 1 to 8, wherein at least one of the compounds represented by the following general formula (1) is used as the dispersant.

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms, an allyl group, or an aralkyl group, 1 represents an integer of 0 to 7, and n represents an integer of 20 to 200.)   The method for producing an aqueous pigment dispersion according to claim 9, wherein the dispersant is POE (n = 40) β-naphthyl ether.   The method for producing an aqueous pigment dispersion according to any one of claims 1 to 10, further comprising a step of heat-treating the aqueous pigment dispersion after the main dispersion step.   An aqueous pigment dispersion produced by the method for producing an aqueous pigment dispersion according to any one of claims 1 to 11.   An aqueous pigment ink comprising the aqueous pigment dispersion according to claim 12.   An ink cartridge containing the water-based pigment ink according to claim 13.   An ink jet recording apparatus comprising: a head that performs recording by discharging the water-based pigment ink according to claim 13.   16. An image forming method comprising printing using the ink jet recording apparatus according to claim 15.   An image formed article printed by the image forming method according to claim 16.   The image-formed product according to claim 17, wherein the image support is paper.