WO2010067783A1

WO2010067783A1 - Azo pigment composition, method for producing azo pigment composition, dispersion containing azo pigment composition, coloring composition, and inkjet recording ink

Info

Publication number: WO2010067783A1
Application number: PCT/JP2009/070509
Authority: WO
Inventors: 桂一立石
Original assignee: 富士フイルム株式会社
Priority date: 2008-12-09
Filing date: 2009-12-08
Publication date: 2010-06-17
Also published as: TW201033295A; JP2010159406A

Abstract

Disclosed is an azo pigment composition which exhibits extremely good hue and light fastness, while having excellent coloring power (color density). Preferably, the azo pigment composition contains an azo pigment, which has characteristic X-ray diffraction peaks at different positions, and a tautomer thereof. The azo pigment composition is characterized by containing at least one kind of azo pigment represented by formula (1) and having characteristic X-ray diffraction peaks at Bragg angles (2?±0.2°) of 7.2° and 25.9° in CuKa characteristic X-ray diffraction or a tautomer thereof.

Description

Azo pigment composition, method for producing azo pigment composition, dispersion containing azo pigment composition, coloring composition, and ink for ink jet recording

The present invention relates to a yellow pigment composition excellent in a wide range of color reproducibility and light resistance, a dispersion containing a yellow pigment composition, and an ink for ink jet recording using a dispersion containing a yellow pigment composition.

In recent years, a material for forming a color image has been mainly used as an image recording material, and specifically, an ink jet recording material, a thermal transfer recording material, an electrophotographic recording material, a transfer halogen. Silver halide photosensitive materials, printing inks, recording pens, and the like are actively used. Further, a color filter is used for recording and reproducing a color image on an image pickup device such as a CCD in a photographing apparatus and on an LCD or PDP in a display. In these color image recording materials and color filters, three primary colors (dyes and pigments) of the so-called additive color mixing method and subtractive color mixing method are used to display or record full color images. The fact is that there are no fast-acting dyes that have absorption characteristics that can satisfy the above conditions and that can withstand various use conditions and environmental conditions, and improvements are strongly desired.

The dyes and pigments used in each of the above applications must have the following properties in common. That is, it has preferable absorption characteristics in terms of color reproducibility, fastness under environmental conditions to be used, for example, light resistance, heat resistance, good resistance to oxidizing gases such as ozone, and the like. In addition, when the pigment is a pigment, it is further substantially insoluble in water and organic solvents and has good chemical fastness, and even when used as particles, the preferred absorption characteristics in the molecular dispersion state are impaired. It is also necessary to have properties such as absence. The required characteristics can be controlled by the strength of intermolecular interaction, but they are in a trade-off relationship and are difficult to achieve both.
In addition, when using the pigment, in addition to having a particle size and a particle shape necessary for expressing the desired transparency, fastness under the environmental conditions used, such as light resistance, heat resistance, Good resistance to oxidative gases such as ozone, and other chemical fastness to organic solvents and sulfurous acid gas. Disperse even fine particles in the medium used, and stable dispersion. , Etc. are also required. In particular, there is a strong demand for a pigment that has a good hue, has high coloring power among light, wet heat, and active gases in the environment, and is fast to light.

In other words, the required performance for pigments is more diverse than dyes that require performance as pigment molecules, and not only the performance as pigment molecules, but also the above requirements as solids (fine particle dispersions) as aggregates of pigment molecules All performance needs to be satisfied. As a result, the group of compounds that can be used as pigments is extremely limited compared to dyes, and even if high-performance dyes are derived into pigments, there are only a few that can satisfy the required performance as fine particle dispersions. It cannot be developed. This is confirmed by the fact that the number of pigments registered in the color index is less than 1/10 of the number of dyes.

Azo pigments are widely used in printing inks, ink-jet inks, electrophotographic materials and the like because they are excellent in hue and coloring power, which are color characteristics. Of these, the most typically used azo pigments are yellow diarylide pigments and red naphthol azo pigments. Examples of diarylide pigments include C.I. I. Pigment Yellow 12, 13 and 17 and the like. Examples of naphthol azo pigments include C.I. I. Pigment Red 208, 242 and the like. However, these pigments are extremely inferior in fastness, particularly light resistance, and are therefore not suitable for long-term storage of printed matter because the pigment is decomposed and faded when the printed matter is exposed to light.

In order to improve such drawbacks, azo pigments having improved fastness by increasing the molecular weight or introducing a group having a strong intermolecular interaction are also disclosed (for example, Patent Documents 1 to 4). 3). However, even in the improved pigment, for example, the pigment described in Patent Document 1 has improved light resistance, but is still insufficient. For example, the pigment described in Patent Documents 2 and 3 has a green hue. There was a drawback that coloring power was lowered by taste and color characteristics were inferior.

Further, Patent Documents 4 to 5 disclose dyes having an absorption characteristic excellent in color reproducibility and sufficient fastness. However, since all of the specific compounds described in the patent document dissolve in water or an organic solvent, the chemical fastness is not sufficient.

When expressing a full color using a subtractive color mixing method of three colors of yellow, magenta and cyan, or four colors with black added, if a pigment with only one color inferior in color fastness is used, the printed gray If the balance is changed and a pigment having poor color characteristics is used, the color reproducibility at the time of printing is lowered. Therefore, in order to obtain a printed matter that maintains a high color reproducibility for a long period of time, a pigment and a pigment dispersion having both color characteristics and fastness are desired.

Conventionally, since azo dyes often have various visible light absorptions, they have been used as dyes in various fields. For example, it has come to be used in various fields such as coloring of synthetic resins, printing inks, dyes for sublimation type thermal transfer materials, inks for ink jets, and dyes for color filters. An absorption spectrum is a large performance required for an azo dye as a dye. The hue of the pigment greatly affects the color and texture of an object colored by the pigment, and has a great effect on vision. Therefore, research on the absorption spectrum of dyes has been conducted for a long time.
Conventionally known azo dyes having a nitrogen-containing 5-membered ring as an azo component are also disclosed in Patent Documents 6 and 7.

In color image formation, a yellow ink composition containing a yellow pigment is used to reproduce the color of the yellow region. Specific examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 128, 129, 138, 139, 150, 151, 154, 155, 180, 185, 213 and the like.

Patent Documents 8 and 9 disclose that the color reproducibility is improved by adjusting a plurality of yellow pigment compositions combined with the yellow pigment in order to reproduce the color in the yellow region over a wide range.
However, a yellow ink composition containing two or more kinds of yellow pigments having good color reproducibility can obtain a wider range of color reproducibility than an ink containing one kind of pigment. Color reproducibility is not sufficient. In addition, when the pigment species having a different hue angle are mixed, the saturation of the secondary color tends to be low. For example, C.I. I. When pigment yellow 110 is used in combination with other pigments, C.I. I. Since Pigment Yellow 110 is tinged with red, green has a drawback that the color saturation becomes low when used in an ink set.
Further, the ink set is required not only to obtain a clear image on a recording medium but also to have no image deterioration due to long-term storage (particularly light resistance). When a color image is formed with a plurality of pigment ink compositions, if even one color is inferior in light resistance, the hue of the image changes and the quality of the color image is extremely deteriorated. For example, C.I. I. Pigment Yellow 74 has a relatively good hue, but its light resistance is remarkably low, so when used in an ink set, the hue of the yellow, red, green, and gray areas changes significantly, so that the color image Quality degradation was a major issue.

On the other hand, in order to reproduce the color of the yellow region over a wide range, Patent Documents 10 and 11 disclose a method using an ink set that further includes a low-intensity yellow ink called dark yellow in addition to a high-intensity yellow ink. Yes.
However, the method of using the second ink composition typified by dark yellow not only tends to increase the number of ink colors but also make the color production complicated and costly, but also the level of improvement is the required performance. It did not reach the level that can be fully satisfied.

Japanese Unexamined Patent Publication No. 56-38354 US Pat. No. 2,936,306 Japanese Unexamined Patent Publication No. 11-1000051 Japanese Unexamined Patent Publication No. 2005-213357 Japanese Laid-Open Patent Publication No. 2003-246942 Japanese Unexamined Patent Publication No. Sho 55-161856 Japanese Unexamined Patent Publication No. 2002-371214 Japanese Unexamined Patent Publication No. 2005-314545 Japanese Patent No. 3911920 Japanese Patent No. 3455764 Japanese Patent No. 3553581

The present invention relates to an azo compound having a crystal form of a bisazo pigment in which a pyrazole ring having a specific substituent is connected to a dye mother nucleus composed of an azo group and another pyrazole ring having a different substituent through a nitrogen-containing heterocycle. Regarding the azo pigment composition containing a pigment or a tautomer thereof, its excellent stability and production method have not been known so far.
The object of the present invention is to provide an azo pigment composition having extremely good hue and light fastness and having excellent coloring power (color density). Preferably, the dye matrix is further different. An object of the present invention is to provide an azo pigment composition containing an azo pigment linked via a nitrogen-containing heterocycle and a tautomer thereof.
Furthermore, this invention aims at providing the coloring composition containing this azo pigment composition.
Furthermore, it is an object of the present invention to provide a coloring composition containing a dispersion of the azo pigment composition and an ink for inkjet recording excellent in color reproducibility and light resistance using the dispersion containing the pigment composition. is there.

As a result of intensive studies in view of the above circumstances, the present inventors have found that an azo pigment composition having a characteristic X-ray diffraction peak at a specific position or an azo pigment composition containing a tautomer thereof has dispersibility and dispersion stability. It was found that the properties were very good and had excellent hue, tinting strength and light resistance.
Further, the present inventors have found that a dispersion in which an azo pigment composition is dispersed and a colored composition can produce an ink for inkjet recording having excellent hue, coloring power and light resistance, and has completed the present invention.

That is, the present invention is as follows.
[1]
An azo pigment or a tautomer represented by the following formula (1) having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction An azo pigment composition comprising at least one kind of active substance.

[2]
Further, the composition has X-ray diffraction peaks having characteristic Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 °, 25.6 ° and 27.7 °. The azo pigment composition according to [1], which contains at least 0.1% by mass to less than 99% by mass of the azo pigment represented by (2) or a tautomer.

[3]
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to [2], which contains at least 1% by mass and less than 70% by mass of an azo pigment or a tautomer.
[4]
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to [2] or [3], wherein the azo pigment or tautomer is contained in an amount of at least 5% by mass and less than 45% by mass.
[5]
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to any one of [2] to [4], wherein the azo pigment or tautomer is contained at least 15% by mass and less than 30% by mass.
[6]
[1] A pigment dispersion containing the azo pigment composition according to any one of [5].
[7]
The pigment dispersion according to [6], wherein the volume average particle diameter of the pigment particles in the pigment dispersion is 0.01 μm to 0.2 μm.
[8]
[1] A colored composition comprising the pigment composition according to any one of [5] as a colorant.
[9]
[1] An ink for inkjet recording comprising the pigment composition according to any one of [5] as a colorant.

According to the present invention, an azo pigment having excellent color characteristics such as coloring power and hue, and excellent dispersibility and dispersion stability is provided. By dispersing the pigment of the present invention in various media, a pigment dispersion having excellent color characteristics, dispersibility and dispersion stability can be obtained. The pigment dispersion is a color product excellent in light fastness, for example, a printing ink such as an inkjet, a color toner for electrophotography, a color filter used in an image pickup device such as a display such as an LCD or PDP, or a CCD, It can be used for paints, colored plastics, etc.

2 is an X-ray diffraction pattern of an azo pigment (1) synthesized according to Synthesis Example 1. FIG. 6 is an X-ray diffraction pattern of an azo pigment (2) synthesized according to Synthesis Example 2. FIG. FIG. 6 is an X-ray diffraction pattern of a crude pigment (1-2) synthesized according to Synthesis Example 3. FIG. 5 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -1 synthesized according to Synthesis Example 3. FIG. 6 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -2 synthesized according to Synthesis Example 4. FIG. 6 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -3 synthesized according to Synthesis Example 5. FIG. 7 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -4 synthesized according to Synthesis Example 6. FIG. 11 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -5 synthesized according to Synthesis Example 7. FIG. 10 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -6 synthesized according to Synthesis Example 8. FIG. 11 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -7 synthesized according to Synthesis Example 9. FIG. 11 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -8 synthesized according to Synthesis Example 10. FIG. 10 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -9 synthesized according to Synthesis Example 11. FIG. 14 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -10 synthesized according to Synthesis Example 12. FIG. 14 is an X-ray diffraction pattern of an α-type crystal form pigment (1) -11 synthesized according to Synthesis Example 13.

Hereinafter, the present invention will be described in detail.
The azo pigment composition of the present invention has the following formula in which the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction has characteristic X-ray diffraction peaks at 7.2 ° and 25.9 °: 1) The azo pigment represented by 1) or a tautomer (hereinafter sometimes simply referred to as an azo pigment represented by formula (1)) is contained.

The X-ray diffraction measurement of the present invention can be performed with a powder X-ray diffraction measurement apparatus RINT2500 (manufactured by Rigaku Corporation) in accordance with Japanese Industrial Standard JISK0131 (general rules for X-ray diffraction analysis).

The content of the azo pigment represented by the formula (1) in the azo pigment composition of the present invention is preferably 30% by weight to 100% by weight, more preferably 55% by weight to 95% by weight with respect to the total solid content. Of these, 70% by mass to 85% by mass is most preferable.
Components other than the azo pigment represented by the formula (1) contained in the azo pigment composition of the present invention include tautomers, crystal polymorphs, salts, water of the azo pigment represented by the formula (1). A Japanese thing etc. can be mentioned.

The azo pigment composition of the present invention contains an azo pigment represented by the formula (1) (azo pigment (1)), so that the azo pigment composition can be used as a dispersion, a colored composition, an inkjet recording ink, or the like. When used, it should be excellent in hue, tinting strength, light / heat / humidity / oxidizing gas (especially ozone gas) fastness and pigment dispersion particle size distribution control (for example, control of liquid properties of pigment ink). it can.

The azo pigment composition of the present invention has a crystal form of the above formula having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction. X-ray diffraction characterized by containing an azo pigment represented by (1) and preferably having a Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 ° and 25.6 ° And an azo pigment represented by the above formula (2) in a crystalline form having a peak.

The azo pigment composition of the present invention preferably further has an X-ray characteristic of Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 °, 25.6 ° and 27.7 °. Contains from 0.1 to less than 99% by mass of an azo pigment or tautomer represented by the following formula (2) having a diffraction peak (hereinafter sometimes referred to simply as an azo pigment represented by formula (2)) More preferably, it is contained in an amount of 1 or more and less than 70% by mass, more preferably at least 5 or more and less than 45% by mass, and more preferably 15 or more and less than 30% by mass.

When the azo pigment composition contains the azo pigment of formula (1) and the azo pigment of formula (2), the proportion of the content of the azo pigment in the azo pigment composition is based on the total weight of the azo pigment. Azo pigment (2) / azo pigment (1) = 0/100 (mass% / mass%) to 99/1 (mass% / mass%), with 5/95 (mass% / mass%) being preferred. To 95/5 (mass% / mass%), more preferably 20/80 (mass% / mass%) to 80/20 (mass% / mass%), and particularly preferably 40 / 60 (mass% / mass%) to 60/40 (mass% / mass%).

In addition, the pigment composition of the present invention contains at least two kinds of azo pigments (1) and (2) in the above range, whereby the azo pigment composition is dispersed, colored composition, ink for inkjet recording, etc. When used in, it is more excellent in hue, tinting strength, light / heat / humidity / oxidizing gas (especially ozone gas) fastness and pigment particle size distribution control (for example, liquid property control of pigment ink). can do.

In the present invention, a crystal represented by the above formula (1) having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction. Form azo pigment and the above formula (2) having characteristic X-ray diffraction peaks at CuKα characteristic X-ray diffraction with Bragg angles (2θ ± 0.2 °) of 7.6 °, 25.6 ° and 27.7 ° The crystal form azo pigment represented by the formula is represented by the diazonium salt derived from the heterocyclic amine (diazo component) represented by the following formula (3) and the following formulas (4) and (5): Examples of the method include obtaining by controlling the reaction conditions (solvent species, pH value, reaction temperature, reaction time, etc.) by a method in which the compound (coupling component) is subjected to an azo coupling reaction. Furthermore, it can be easily obtained by adjusting the conditions (solvent type, pH value, reaction temperature, reaction time, etc.) when the azo pigment obtained in the above step is further processed in the subsequent step.

The azo pigment composition of the present invention is preferably prepared by separately producing an azo pigment represented by the above formula (1) or an azo pigment represented by the above (2), and optionally mixing it in a preferred content ratio. Alternatively, a diazonium salt derived from a heterocyclic amine (diazo component) represented by the above formula (3) and a compound (coupling component) represented by the above formulas (4) and (5) are optionally mixed. It is also possible to produce and use an azo pigment mixture by a method of azo coupling reaction.
In the pigment dispersion of the present invention, the azo pigment comprising the crystal form azo pigment represented by the above formula (1) and preferably the crystal form azo pigment represented by the above formula (2) in a preferred range of content. From the viewpoint of stably producing the composition with stable quality, a method in which an azo pigment is arbitrarily mixed and used at a preferable content ratio is preferable.

In the case of a single crystal form, the molecules become dense and the intermolecular interaction becomes strong. As a result, the solvent resistance, thermal stability, light resistance, gas resistance and printing density are increased, and the color reproduction range is further expanded.

Therefore, the azo pigment represented by the above formula (1) has characteristic X-ray diffraction peaks when the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is 7.2 ° and 25.9 °. A crystal form having X-ray diffraction peaks characteristic at 7.2 °, 15.0 °, 19.8 °, and 25.9 ° is more preferable. Among them, crystal forms having characteristic X-ray diffraction peaks at 7.2 °, 8.2 °, 10.0 °, 13.4 °, 15.0 °, 19.8 ° and 25.9 °, among others. Is most preferred.

Further, the azo pigment represented by the above formula (2) is characterized by Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 °, 25.6 ° and 27.7 °. Crystal forms having X-ray diffraction peaks are preferred, and crystal forms having characteristic X-ray diffraction peaks at 7.6 °, 13.5 °, 25.6 ° and 27.7 ° are more preferred. Among them, a crystal form having characteristic X-ray diffraction peaks at 7.6 °, 13.5 °, 15.9 °, 16.9 °, 25.6 ° and 27.7 ° is most preferable.

The length in the major axis direction when the primary particles of the azo pigment represented by the above formulas (1) and (2) are observed with a transmission microscope is preferably 0.01 μm or more and 30 μm or less. 0.02 μm or more and 30 μm or less is more preferable, and 0.03 μm or more and 2 μm or less is particularly preferable.

When the length of the major axis when the primary particles are observed with a transmission microscope is 0.01 μm or more, the fastness to light and ozone, and the dispersibility when used as a pigment dispersion are more reliable. Can be expressed. On the other hand, when the particle size is 30 μm or less, it is difficult to be in an overdispersed state (a form in which primary particles are destroyed) when dispersed to have a desired volume average particle diameter, and the active surface is not easily exposed on the surface of pigment particles. Therefore, aggregation is difficult to occur, so that the storage stability of the pigment dispersion can be expressed more reliably.

By controlling the size of the primary particles within the above-mentioned range, the intra- and inter-molecular interaction is strong and becomes a strong and stable pigment particle that forms a three-dimensional particle and a workpiece. Light, heat, humidity, A colored product using a pigment dispersion exhibiting high fastness to an oxidizing gas is preferable because of its excellent storage stability.

For measurement of the volume average particle size of the pigment dispersion containing the pigment composition of the present invention, a Nanotrac UPA particle size analyzer (UPA-EX150; manufactured by Nikkiso Co., Ltd.) can be used. The measurement can be performed, for example, by placing 3 ml of pigment dispersion in a measurement cell and according to a predetermined measurement method. As parameters input at the time of measurement, the ink viscosity is used as the viscosity, and the pigment density is used as the density of the dispersed particles.

An azo pigment represented by the above formula (1) having a crystal form having characteristic X-ray diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction The average particle size is preferably 0.01 μm or more and 30 μm or less, more preferably 0.02 μm or more and 10 μm or less, and most preferably 0.03 μm or more and 1 μm or less.

An azo pigment represented by the above formula (2) in the form of a crystal having characteristic X-ray diffraction peaks at a Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 ° and 25.6 ° The average particle size is preferably from 0.01 μm to 30 μm, more preferably from 0.02 μm to 30 μm, and most preferably from 0.03 μm to 20 μm.

If it is in the above range, the print density of the printed matter is high, the stability of the dispersion is increased, the color reproducibility of the mixed color portion such as red and green is improved, the transparency is high, and when printing with an inkjet or the like. It is preferable because nozzle clogging is less likely to occur. Further, it is preferable from the viewpoint that aggregation of the pigment dispersion hardly occurs and stability with time of the dispersion becomes high.

The volume average particle diameter of the pigment dispersion containing the pigment composition of the present invention can be easily adjusted by combining the below-described pigment dispersion conditions for convenience.

Below, the azo pigment represented by the following formula (1) having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction: Alternatively, a method for producing an azo pigment composition containing at least one tautomer will be described in detail.

The production method of the azo pigment composition represented by the following formula (1) is represented by the diazonium salt derived from the heterocyclic amine (diazo component) represented by the following formula (3) and the following formula (4). A step of subjecting the compound (coupling component) to an azo coupling reaction.

Next, an azo pigment represented by the following formula (2) having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 ° and 25.6 °: Alternatively, a method for producing an azo pigment composition containing at least one tautomer will be described in detail.

The production method of the azo pigment composition represented by the following formula (2) is represented by the diazonium salt derived from the heterocyclic amine (diazo component) represented by the following formula (3) and the following formula (5). A step of subjecting the compound (coupling component) to an azo coupling reaction.

[Diazonium salt preparation step of heterocyclic amine]
Preparation of heterocyclic amine (diazo component) represented by the above formula (3) into a diazonium salt and coupling reaction of the diazonium salt with the compounds represented by the above formulas (4) and (5) (coupling component) Can be carried out by conventional methods.

Preparation of the diazonium salt of the heterocyclic amine represented by the above formula (3) is performed in a reaction medium containing, for example, an acid (for example, hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, propionic acid, methanesulfonic acid, trifluoromethanesulfonic acid, etc.). A conventional diazonium salt preparation method using a nitrosonium ion source such as nitrous acid, nitrite or nitrosylsulfuric acid can be applied.

Examples of more preferred acids include the case where acetic acid, propionic acid, methanesulfonic acid, phosphoric acid and sulfuric acid are used alone or in combination, among which phosphoric acid or a combined system of acetic acid and sulfuric acid, acetic acid and propion A combined system of acid, a combined system of acetic acid, propionic acid and sulfuric acid is more preferable, and a combined system of acetic acid and propionic acid and a combined system of acetic acid, propionic acid and sulfuric acid are particularly preferable.

As preferred examples of the reaction medium (solvent), organic acids and inorganic acids are preferably used, and phosphoric acid, sulfuric acid, acetic acid, propionic acid, and methanesulfonic acid are particularly preferable. Among these, acetic acid and propionic acid are preferable.

Examples of preferred nitrosonium ion sources include nitrites, nitrites, nitrosylsulfuric acid and the like. Among them, sodium nitrite, potassium nitrite, isoamyl nitrite, nitrosylsulfuric acid (e.g., ONHSO ₄ sulfuric acid solution) are preferred, isoamyl nitrite, nitrosylsulfuric acid (e.g., 40 wt% to 50 wt% ONHSO ₄ sulfuric acid solution) Among these, the use of nitrosylsulfuric acid in the above-mentioned preferable acid-containing reaction medium can prepare a diazonium salt stably and efficiently.

The amount of the solvent used for the diazo component of the formula (3) is preferably 0.5 to 50 times by mass, more preferably 1 to 20 times by mass, and particularly preferably 3 to 15 times by mass.

In the present invention, the diazo component of the formula (3) may be in a state of being dispersed in a solvent, or may be in a solution state depending on the kind of the diazo component.

The amount of the nitrosonium ion source used is preferably 0.95 to 5.0 equivalents, more preferably 1.00 to 3.00 equivalents, particularly 1.00 to 1.10 equivalents, relative to the diazo component. Is preferred.

The reaction temperature is preferably −15 ° C. to 40 ° C., more preferably −5 ° C. to 35 ° C., and further preferably −0 ° C. to 30 ° C. Below -15 ° C, the reaction rate is remarkably slow and the time required for the synthesis is remarkably long, which is not economical. When synthesis is performed at a high temperature exceeding 40 ° C, the amount of by-products increases, which is preferable. Absent.

The reaction time is preferably 30 minutes to 300 minutes, more preferably 30 minutes to 200 minutes, and still more preferably 30 minutes to 150 minutes.

[Coupling reaction process]
The step of coupling reaction can be carried out in an acidic reaction medium to a basic reaction medium, but the azo pigment of the present invention is preferably carried out in an acidic to neutral reaction medium, particularly in an acidic reaction medium. It is possible to efficiently induce the azo pigment by suppressing the decomposition of the diazonium salt.

As a preferable example of the reaction medium (solvent), an organic acid, an inorganic acid, or an organic solvent can be used, but an organic solvent is particularly preferable, and a solvent that does not cause a liquid separation phenomenon during the reaction and presents a uniform solution with the solvent. preferable. For example, alcoholic organic solvents such as methanol, ethanol, propanol, isopropanol, butanol, t-butyl alcohol, amyl alcohol, ketone organic solvents such as acetone, methyl ethyl ketone, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene Diol organic solvents such as glycol and 1,3-propanediol, ether organic solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol diethyl ether, tetrahydrofuran, dioxane, acetonitrile, and the like. May be a mixture of two or more.

Preferably, the organic solvent has a polarity parameter (ET) value of 40 or more. Among them, a glycol solvent having two or more hydroxyl groups in a solvent molecule, an alcohol solvent having 3 or less carbon atoms, a ketone solvent having a total carbon number of 5 or less, preferably an alcohol having 2 or less carbon atoms. Solvents (for example, methanol, ethylene glycol) and ketone solvents having a total carbon number of 4 or less (for example, acetone, methyl ethyl ketone) are preferable. These mixed solvents are also included.

The amount of the solvent used is preferably 1 to 100 times by mass, more preferably 1 to 50 times by mass, and further preferably 2 to 30 times by mass of the coupling component represented by the above formulas (4) and (5). is there.

In the present invention, the coupling component represented by the formulas (4) and (5) may be in a state where it is dispersed in a solvent, or it may be in a solution state depending on the type of the coupling component. good.

The amount of the coupling component used is preferably from 0.95 to 5.0 equivalents, more preferably from 1.00 to 3.00 equivalents, particularly from 1.00 to 1.50, based on the azo coupling site. It is preferable that it is equivalent.

The reaction temperature is preferably −30 ° C. to 30 ° C., more preferably −15 ° C. to 10 ° C., and further preferably −10 ° C. to 5 ° C. Less than −30 ° C. is not economical because the reaction rate is remarkably slow and the time required for the synthesis becomes remarkably long. Also, when synthesis is performed at a high temperature exceeding 30 ° C., the amount of by-products increases, which is preferable. Absent.

In the method for producing an azo pigment composition of the present invention, the product (crude azo pigment) obtained by these reactions is treated according to a post-treatment method of a normal organic synthesis reaction and then purified or used without purification. be able to.

That is, for example, the product liberated from the reaction system can be used without being purified, or can be purified by recrystallization, salt formation or the like alone or in combination.

After completion of the reaction, the reaction solvent is distilled off, or it is poured into water or ice without being distilled off, and the liberated product is extracted with neutralization or without neutralization, or extracted with an organic solvent / aqueous solution. It can also be used after purification or refining by recrystallization, crystallization, salt formation or the like, either alone or in combination.

The method for producing the azo pigment composition of the present invention will be described in more detail.

The method for producing an azo pigment composition of the present invention comprises coupling a diazonium compound obtained by diazonium-izing a heterocyclic amine represented by the above formula (3) and a compound represented by the above formulas (4) and (5). In the reaction, the compound represented by the formulas (4) and (5) is dissolved in an organic solvent, and then a coupling reaction is performed.

The diazonium salt preparation reaction of the heterocyclic amine represented by the above formula (3) is carried out at a temperature of 15 ° C. or less with a reagent such as sodium nitrite and nitrosylsulfuric acid in an acidic solvent such as sulfuric acid, phosphoric acid and acetic acid. The reaction can be carried out for about 6 minutes to 6 hours. In the coupling reaction, the diazonium salt obtained by the above method is reacted with the compounds represented by the above formulas (4) and (5) at 40 ° C. or less, preferably 15 ° C. or less for about 10 minutes to 12 hours. It is preferable to carry out with.

The above-described tautomerization and / or crystal polymorphism can be controlled by the production conditions in the coupling reaction. A more preferred form of the present invention is a crystal of formula (1) having X-ray diffraction peaks characteristic at 7.2 ° and 25.9 °, or features at 7.6 °, 25.6 ° and 27.7 °. As a method for producing a pigment composition mainly composed of crystals of the formula (2) having a typical X-ray diffraction peak, for example, the compounds represented by the above formulas (4) and (5) are once used in an organic solvent. It is preferable to use the method of the present invention in which a coupling reaction is carried out after dissolution. Examples of the organic solvent that can be used at this time include alcohol solvents and ketone solvents. As examples of the alcohol solvent, methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol and the like are preferable, and methanol is particularly preferable among them. As an example of the ketone solvent, acetone, methyl ethyl ketone, cyclohexanone and the like are preferable, and acetone is particularly preferable among them.

Another method for producing an azo pigment composition according to the present invention includes a diazonium compound obtained by diazonium-izing a heterocyclic amine represented by the above formula (3), and a compound represented by the above formulas (4) and (5). In the coupling reaction, the coupling reaction is performed in the presence of a polar aprotic solvent.

Even by a method in which a coupling reaction is carried out in the presence of a polar aprotic solvent, crystals of formula (1) having characteristic X-ray diffraction peaks at 7.2 ° and 25.9 ° or 7.6 °, 25. It is possible to efficiently produce a pigment composition mainly composed of crystals of the formula (2) having X-ray diffraction peaks characteristic at 6 ° and 27.7 °. Examples of polar aprotic solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, tetramethylurea, acetone, methyl ethyl ketone, acetonitrile, and mixed solvents thereof Etc. Among these solvents, acetone, methyl ethyl ketone, N, N-dimethylacetamide, and acetonitrile are particularly preferable. When these solvents are used, the compound represented by the above formula (3) may or may not be completely dissolved in the solvent.

Depending on the use, the compound obtained by the above production method may or may not be adjusted to pH by adding a base as a purification step. When adjusting the pH, the pH is preferably 4 to 10. Among them, the pH is more preferably 5 to 8, and particularly preferably 5.5 to 7.5.

When the pH is 10 or less, it is preferable from the viewpoint of securing a hue of a certain quality without causing discoloration and fading from the viewpoint of hue and without increasing redness. When the pH is 4 or more, for example, when used as an inkjet recording ink, it is preferable because problems such as corrosion of the nozzle hardly occur.

By the above production method, the compounds represented by the above formulas (1) and (2) are obtained as crude azo pigments (crude).
The present invention also relates to an azo pigment composition produced by the above production method.

[Post-treatment process]
In the manufacturing method of this invention, it is preferable to include the process of performing a post-process. As a method of this post-treatment step, for example, solvent particle milling process such as solvent salt milling, salt milling, dry milling, solvent milling, acid pasting, pigment heat control process, solvent heating treatment, etc., resin, surfactant and dispersion And a surface treatment step using an agent.

The compounds represented by the above formulas (1) and (2) of the present invention are preferably subjected to solvent heating treatment and / or solvent salt milling as a post-treatment step. For example, an azo pigment having a desired crystal form can be produced by refluxing in an organic solvent excluding water.

Examples of the solvent used in the solvent heat treatment include water, aromatic hydrocarbon solvents such as toluene and xylene, halogenated hydrocarbon solvents such as chlorobenzene and o-dichlorobenzene, and alcohols such as isopropanol and isobutanol. Examples include solvents, polar aprotic organic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, acetone, methyl ethyl ketone, and acetonitrile, glacial acetic acid, pyridine, or a mixture thereof. It is done. An inorganic or organic acid or base may be further added to the solvents mentioned above.

The temperature of the solvent heat treatment varies depending on the desired primary particle size of the pigment, but is preferably 40 to 150 ° C., more preferably 60 to 100 ° C. The treatment time is preferably 30 minutes to 24 hours.

Solvent salt milling includes, for example, charging a crude azo pigment, an inorganic salt, and an organic solvent that does not dissolve it into a kneader, and kneading and grinding therein. As the inorganic salt, a water-soluble inorganic salt can be preferably used. For example, an inorganic salt such as sodium chloride, potassium chloride, sodium sulfate is preferably used. It is more preferable to use an inorganic salt having an average particle size of 0.5 to 50 μm. The amount of the inorganic salt used is preferably 3 to 20 times by mass, more preferably 5 to 15 times by mass with respect to the crude azo pigment. As the organic solvent, a water-soluble organic solvent can be suitably used, and the solvent easily evaporates due to a temperature rise during kneading, so that a high boiling point solvent is preferable from the viewpoint of safety. Examples of such organic solvents include diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, di Propylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene Glycol or mixtures thereof. The amount of the water-soluble organic solvent used is preferably 0.1 to 5 times by mass with respect to the crude azo pigment. The kneading temperature is preferably 20 to 130 ° C, particularly preferably 40 to 110 ° C. As a kneader, for example, a kneader or a mix muller can be used.

(Pigment dispersion)
The pigment dispersion of the present invention is characterized by containing at least one azo pigment of the present invention represented by the above (1), more preferably the azo pigment of the present invention represented by the above (2). It is characterized by being used together. Thereby, it can be set as the pigment dispersion excellent in chromatic characteristics, durability, and dispersion stability.

The pigment dispersion of the present invention may be aqueous or non-aqueous, but is preferably an aqueous pigment dispersion. As the aqueous liquid in which the pigment is dispersed in the aqueous pigment dispersion of the present invention, a mixture containing water as a main component and optionally adding a hydrophilic organic solvent can be used. Examples of the hydrophilic organic solvent include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol and other alcohols, ethylene glycol, diethylene glycol , Other alcohols such as triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, ethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, ethylene glycol butyl ether, diethylene glycol mono Chill ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate triethylene glycol monoethyl ether, ethylene glycol monophenyl ether Glycol derivatives such as ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine Such as amine, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidone, 1 , 3-dimethyl-2-imidazolidinone, acetonitrile, acetone and the like.

Furthermore, the aqueous pigment dispersion of the present invention may contain an aqueous resin. Examples of the aqueous resin include water-soluble resins that dissolve in water, water-dispersible resins that disperse in water, colloidal dispersion resins, and mixtures thereof. Specific examples of the aqueous resin include acrylic, styrene-acrylic, polyester, polyamide, polyurethane, and fluorine resins.

Furthermore, surfactants and dispersants may be used to improve pigment dispersion and image quality. Examples of the surfactant include anionic, nonionic, cationic and amphoteric surfactants. Any surfactant may be used, but anionic or nonionic surfactants may be used. It is preferable to use it. Examples of anionic surfactants include fatty acid salts, alkyl sulfate esters, alkylbenzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl diaryl ether disulfonates, alkyl phosphates, and polyoxyethylene alkyls. Examples thereof include ether sulfate, polyoxyethylene alkylaryl ether sulfate, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester, polyoxyethylene glycerol fatty acid ester and the like.

Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin Examples include fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, fluorine-based resins, and silicon-based materials.

The non-aqueous pigment dispersion is obtained by dispersing the pigments represented by the above formulas (1) and (2) in a non-aqueous vehicle. Resins used in non-aqueous vehicles are, for example, petroleum resins, casein, shellac, rosin modified maleic resin, rosin modified phenolic resin, nitrocellulose, cellulose acetate butyrate, cyclized rubber, chlorinated rubber, oxidized rubber, hydrochloric acid rubber , Phenolic resin, alkyd resin, polyester resin, unsaturated polyester resin, amino resin, epoxy resin, vinyl resin, vinyl chloride, vinyl chloride-vinyl acetate copolymer, acrylic resin, methacrylic resin, polyurethane resin, silicone resin, fluorine resin , Drying oil, synthetic drying oil, styrene / maleic acid resin, styrene / acrylic resin, polyamide resin, polyimide resin, benzoguanamine resin, melamine resin, urea resin chlorinated polypropylene, butyral resin, vinylidene chloride resin and the like. A photocurable resin may be used as the non-aqueous vehicle.

Examples of the solvent used in the non-aqueous vehicle include aromatic solvents such as toluene, xylene, and methoxybenzene, and acetates such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Solvents, propionate solvents such as ethoxyethyl propionate, alcohol solvents such as methanol and ethanol, ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketone solvents, aliphatic hydrocarbon solvents such as hexane, N, N-dimethylformamide, γ-butyrolactam, - methyl-2-pyrrolidone, aniline, nitrogen compound-based solvent such as pyridine, a lactone-based solvents such as γ- butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate acid.

The pigment dispersion of the present invention can be obtained by dispersing the above azo pigment and an aqueous or non-aqueous medium using a dispersing device. Dispersing devices include simple stirrer, impeller stirring method, in-line stirring method, mill method (for example, colloid mill, ball mill, sand mill, bead mill, attritor, roll mill, jet mill, paint shaker, agitator mill, etc.), ultrasonic method Further, a high-pressure emulsification dispersion system (high-pressure homogenizer; specific commercially available devices such as gorin homogenizer, microfluidizer, DeBEE2000, etc.) can be used.

In the present invention, the volume average particle diameter of the pigment particles is preferably 0.01 μm to 0.2 μm. The volume average particle diameter of the pigment particles refers to the particle diameter of the pigment itself or the particle diameter to which the additive has adhered when an additive such as a dispersant is attached to the colorant. In the present invention, a Nanotrac UPA particle size analyzer (UPA-EX150; manufactured by Nikkiso Co., Ltd.) was used as a measuring device for the volume average particle diameter of pigment particles. The measurement was performed according to a predetermined measuring method by placing 3 ml of the pigment dispersion in a measuring cell. As parameters to be input at the time of measurement, the ink viscosity was used as the viscosity, and the pigment density was used as the density of the dispersed particles.

A more preferable volume average particle diameter is 20 nm or more and 200 nm or less, more preferably 30 nm or more and 180 nm or less, and most preferably 30 nm or more and 150 nm or less. When the volume average particle diameter of the particles in the pigment dispersion is less than 20 nm, there are cases where the storage stability cannot be ensured, while when it exceeds 250 nm, the optical density may be lowered.

The concentration of the pigment contained in the pigment dispersion of the present invention is preferably in the range of 1 to 35% by mass, more preferably in the range of 2 to 25% by mass. If the density is less than 1% by mass, sufficient image density may not be obtained when the pigment dispersion is used alone as the ink. If the concentration exceeds 35% by mass, the dispersion stability may decrease.

Applications of the azo pigments of the present invention include image recording materials for forming images, particularly color images. Specifically, the ink-jet recording materials described in detail below, thermal recording materials, Pressure recording material, recording material using an electrophotographic method, transfer type silver halide photosensitive material, printing ink, recording pen, etc., preferably an ink jet recording material, a thermal recording material, a recording material using an electrophotographic method, More preferred are ink jet recording materials.

Also, it can be applied to a solid-state image pickup device such as a CCD, a color filter for recording / reproducing a color image used in a display such as an LCD or a PDP, and a dyeing solution for dyeing various fibers.

The azo pigment of the present invention is used by adjusting physical properties such as solvent resistance, dispersibility, and heat mobility suitable for its use with a substituent. Further, the azo pigment of the present invention can be used in an emulsified dispersion state, and further in a solid dispersion state, depending on the system used.

(Coloring composition)
The coloring composition of the present invention contains the azo pigment composition of the present invention as a colorant. The coloring composition of the present invention can contain a medium, but when a solvent is used as the medium, it is particularly suitable as an ink for inkjet recording. The coloring composition of the present invention can be produced by using a lipophilic medium or an aqueous medium as a medium and dispersing the azo pigment of the present invention in the medium. Preferably, an aqueous medium is used. The coloring composition of the present invention includes an ink composition excluding a medium. The coloring composition of the present invention may contain other additives as necessary within a range that does not impair the effects of the present invention. Other additives include, for example, anti-drying agents (wetting agents), anti-fading agents, emulsion stabilizers, penetration enhancers, ultraviolet absorbers, preservatives, anti-fungal agents, pH adjusters, surface tension adjusters, Known additives (described in JP-A No. 2003-306623) such as foaming agents, viscosity modifiers, dispersants, dispersion stabilizers, rust preventives, chelating agents and the like can be mentioned. These various additives are directly added to the ink liquid in the case of water-soluble ink. In the case of oil-soluble ink, it is common to add to the dispersion after preparation of the azo pigment dispersion, but it may be added to the oil phase or water phase at the time of preparation.

〔ink〕
Next, the ink of the present invention will be described.
It contains the pigment dispersion of the present invention described above, and is preferably prepared by mixing a water-soluble solvent, water and the like. However, if there is no particular problem, the pigment dispersion of the present invention may be used as it is.
The ink for inkjet recording of the present invention contains the pigment dispersion of the present invention, and the ink of the present invention can also be used as an ink for inkjet recording.

The coloring composition containing the pigment of the present invention can be preferably used as an ink for ink jet recording.

The pigment dispersion described above is used for the ink of the present invention. Preferably, it is prepared by mixing a water-soluble solvent, water and the like. However, if there is no particular problem, the pigment dispersion of the present invention may be used as it is.

[Ink for inkjet recording]
Next, the ink for ink jet recording will be described.

The ink for inkjet recording of the present invention contains an azo pigment composition as a colorant. The pigment dispersion described above is used for the ink for inkjet recording (hereinafter sometimes referred to as “ink”). Preferably, it is prepared by mixing a water-soluble solvent, water and the like. However, if there is no particular problem, the pigment dispersion of the present invention may be used as it is.

The content ratio of the pigment dispersion in the ink is preferably in the range of 1 to 100% by mass, considering the hue, color density, saturation, transparency, etc. of the image formed on the recording medium, and is preferably 3 to 20% by mass. The range is particularly preferable, and the range of 3 to 10% by mass is most preferable.

The pigment of the present invention is preferably contained in an amount of 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and more preferably 1 to 10 parts by mass in 100 parts by mass of the ink. It is more preferable to contain. Further, in the ink of the present invention, other pigments may be used in combination with the pigment of the present invention. When two or more kinds of pigments are used in combination, the total content of the pigments is preferably within the above range.

The ink can be used not only for forming a single color image but also for forming a full color image. In order to form a full color image, a magenta color ink, a cyan color ink, and a yellow color ink can be used, and a black color ink may be further used to adjust the color tone.

Furthermore, in the ink according to the present invention, other pigments can be used simultaneously in addition to the azo pigment according to the present invention. Examples of yellow pigments that can be applied include C.I. I. P. Y. -74, C.I. I. P. Y. -128, C.I. I. P. Y. -155, C.I. I. P. Y. -213, and applicable magenta pigments include C.I. I. P. V. -19, C.I. I. P. R. -122, and examples of applicable cyan pigments include C.I. I. P. B. -15: 3, C.I. I. P. B. -15: 4, and any of these can be used separately. Applicable black materials include disazo, trisazo, and tetraazo pigments, as well as carbon black dispersions.

As the water-soluble solvent used in the ink, polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, sulfur-containing solvents and the like are used.

Specific examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, and glycerin.

Examples of the polyhydric alcohol derivative include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diglycerin. And ethylene oxide adducts.

Examples of the nitrogen-containing solvent include pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, and triethanolamine. Examples of alcohols include alcohols such as ethanol, isopropyl alcohol, butyl alcohol, and benzyl alcohol. Examples of the solvent include thiodiethanol, thiodiglycerol, sulfolane, dimethyl sulfoxide and the like. In addition, propylene carbonate, ethylene carbonate, or the like can be used.

The water-soluble solvent used in the present invention may be used alone or in combination of two or more. The content of the water-soluble solvent is 1% by mass or more and 60% by mass or less, preferably 5% by mass or more and 40% by mass or less of the entire ink. When the amount of the water-soluble solvent in the ink is less than 1% by mass, a sufficient optical density may not be obtained. Conversely, when the amount is more than 60% by mass, the viscosity of the liquid increases. In some cases, the ejection characteristics of the ink liquid become unstable.

The preferred physical properties of the ink in the present invention are as follows. The surface tension of the ink is preferably 20 mN / m or more and 60 mN / m or less. More preferably, it is 20 mN or more and 45 mN / m or less, More preferably, it is 25 mN / m or more and 35 mN / m or less. If the surface tension is less than 20 mN / m, liquid may overflow on the nozzle surface of the recording head, and printing may not be performed normally. On the other hand, if it exceeds 60 mN / m, the permeability to the recording medium after printing may be slow, and the drying time may be slow. The surface tension was measured under the environment of 23 ° C. and 55% RH using a Wilhelmy surface tension meter as described above.

The viscosity of the ink is preferably from 1.2 mPa · s to 8.0 mPa · s, more preferably from 1.5 mPa · s to less than 6.0 mPa · s, still more preferably from 1.8 mPa · s to 4. It is less than 5 mPa · s. When the viscosity is greater than 8.0 mPa · s, the dischargeability may be reduced. On the other hand, when it is smaller than 1.2 mPa · s, the long-term jetting property may deteriorate.

The viscosity (including those described later) was measured using a rotational viscometer Rheomat 115 (manufactured by Contraves) at 23 ° C. and a shear rate of 1400 s ⁻¹ .

In addition to the above components, water is added to the ink in a range that achieves the above-described preferable surface tension and viscosity. The amount of water added is not particularly limited, but is preferably 10% by mass to 99% by mass, and more preferably 30% by mass to 80% by mass with respect to the entire ink.

Furthermore, if necessary, for the purpose of controlling properties such as improvement in ejection performance, cellulose derivatives such as polyethyleneimine, polyamines, polyvinylpyrrolidone, polyethylene glycol, ethylcellulose, carboxymethylcellulose, polysaccharides and derivatives thereof, other water-soluble polymers, acrylics Polymer emulsion, polyurethane emulsion, polymer emulsion such as hydrophilic latex, hydrophilic polymer gel, cyclodextrin, macrocyclic amines, dendrimers, crown ethers, urea and its derivatives, acetamide, silicone surfactant, fluorine-based A surfactant or the like can be used.

In order to adjust conductivity and pH, compounds of alkali metals such as potassium hydroxide, sodium hydroxide, lithium hydroxide, ammonium hydroxide, triethanolamine, diethanolamine, ethanolamine, 2-amino-2-methyl Nitrogen-containing compounds such as 1-propanol, alkaline earth metal compounds such as calcium hydroxide, acids such as sulfuric acid, hydrochloric acid and nitric acid, strong acid and weak alkali salts such as ammonium sulfate, and the like can be used.

Other pH buffering agents, antioxidants, fungicides, viscosity modifiers, conductive agents, ultraviolet absorbers, etc. can be added as necessary.

[Inkjet recording method, inkjet recording apparatus, and ink tank for inkjet recording]
The ink jet recording method is a method of forming an image on the surface of a recording medium by using ink for ink jet recording and discharging the ink from the recording head to the surface of the recording medium in accordance with a recording signal.
Further, the ink jet recording apparatus includes a recording head that uses ink for ink jet recording and ejects ink (if necessary, treatment liquid) onto the surface of the recording medium. It is an apparatus to form. The ink jet recording apparatus supplies an ink tank for ink jet recording (hereinafter sometimes referred to as “ink tank”) that can supply ink to the recording head and is detachable from the main body of the ink jet recording apparatus. You may have. In this case, ink is stored in the ink tank for ink jet recording.

As the ink jet recording apparatus, a normal ink jet recording apparatus having a printing method capable of using ink for ink jet recording can be used. In addition to this, a heater for controlling the drying of the ink as necessary is provided. It may be mounted, or may be equipped with an intermediate transfer mechanism, and a mechanism for discharging (printing) ink and processing liquid onto the intermediate and then transferring it to a recording medium such as paper.
Further, an ink tank for ink jet recording is detachable from an ink jet recording apparatus equipped with a recording head, and can be used as long as it has a configuration capable of supplying ink to the recording head while attached to the ink jet recording apparatus. A known ink tank can be used.

The ink jet recording method (apparatus) preferably employs a thermal ink jet recording method or a piezo ink jet recording method from the viewpoint of the effect of improving bleeding and intercolor bleeding. In the case of the thermal ink jet recording method, the ink is heated at the time of ejection and has a low viscosity, but the viscosity rapidly increases because the temperature of the ink is lowered on the recording medium. For this reason, there is an effect of improving bleeding and intercolor bleeding. On the other hand, in the case of the piezo ink jet method, it is possible to discharge a high-viscosity liquid, and the high-viscosity liquid can suppress spreading in the paper surface direction on the recording medium. There is an improvement effect on intercolor bleeding.

In the ink jet recording method (apparatus), replenishment (supply) of ink to the recording head is preferably performed from an ink tank filled with ink liquid (including a treatment liquid tank if necessary). The ink tank is preferably of a cartridge type that can be attached to and detached from the apparatus main body, and ink can be easily replenished by exchanging the cartridge type ink tank.

[Color toner]
The content of the azo pigment in 100 parts by weight of the color toner is not particularly limited, but is preferably 0.1 parts by weight or more, more preferably 1 to 20 parts by weight, and most preferably 2 to 10 parts by weight. preferable. As a binder resin for a color toner into which an azo pigment is introduced, all commonly used binders can be used. Examples thereof include styrene resin, acrylic resin, styrene / acrylic resin, and polyester resin.
Inorganic fine powders and organic fine particles may be externally added to the toner for the purpose of improving fluidity and controlling charging. Silica fine particles and titania fine particles whose surface is treated with an alkyl group-containing coupling agent or the like are preferably used. These have a number average primary particle size of preferably 10 to 500 nm, and more preferably 0.1 to 20% by mass in the toner.

As the release agent, all conventionally used release agents can be used. Specific examples include olefins such as low molecular weight polypropylene, low molecular weight polyethylene, and ethylene-propylene copolymer, microcrystalline wax, carnauba wax, sazole wax, and paraffin wax. These addition amounts are preferably 1 to 5% by mass in the toner.

The charge control agent may be added as necessary, but is preferably colorless from the viewpoint of color development. Examples thereof include those having a quaternary ammonium salt structure and those having a calixarene structure.

As the carrier, either an uncoated carrier composed only of magnetic material particles such as iron or ferrite, or a resin-coated carrier in which the magnetic material particle surface is coated with a resin or the like may be used. The average particle size of this carrier is preferably 30 to 150 μm in terms of volume average particle size.

The image forming method to which the toner is applied is not particularly limited. For example, a method of forming a color image by repeatedly forming a color image on a photoconductor to form an image, or an image formed on a photoconductor For example, a method of sequentially transferring to an intermediate transfer member or the like, forming a color image on the intermediate transfer member or the like, and then transferring the image to an image forming member such as paper to form a color image.

[Thermal recording (transfer) material]
The heat-sensitive recording material includes an ink sheet in which the azo pigment of the present invention is coated on a support together with a binder, and an image-receiving sheet that fixes a pigment that has migrated in response to thermal energy applied from a thermal head in accordance with an image recording signal. Composed. The ink sheet can be formed by preparing an ink liquid by dispersing the azo pigment of the present invention in the form of fine particles in a solvent together with a binder, applying the ink on a support, and drying it appropriately. The amount of ink applied on the support is not particularly limited, but is preferably 30 to 1000 mg / m ² . As a preferable binder resin, ink solvent, support, and image receiving sheet, those described in JP-A-7-137466 can be preferably used.

In order to apply the heat-sensitive recording material to a heat-sensitive recording material capable of full-color image recording, a cyan ink sheet containing a heat-diffusible cyan dye capable of forming a cyan image, and heat diffusion capable of forming a magenta image. It is preferable to form a magenta ink sheet containing a reactive magenta dye and a yellow ink sheet containing a heat diffusible yellow dye capable of forming a yellow image by sequentially coating the support. In addition, an ink sheet containing a black image forming substance may be further formed as necessary.

[Color filter]
As a method for forming a color filter, a pattern is first formed with a photoresist and then dyed, or disclosed in JP-A-4-163552, JP-A-4-128703, and JP-A-4-175653. Thus, there is a method of forming a pattern with a photoresist to which a dye is added. Any of these methods may be used as a method for introducing the coloring matter of the present invention into a color filter. Preferred methods are described in JP-A-4-175533 and JP-A-6-35182. The positive resist composition comprising a thermosetting resin, a quinonediazide compound, a cross-linking agent, a dye and a solvent, and after coating on a substrate, exposing through a mask and developing the exposed portion. Then, a positive resist pattern is formed, the positive resist pattern is exposed on the entire surface, and then the exposed positive resist pattern is cured, and a color filter forming method can be mentioned. In addition, a black matrix is formed according to a conventional method, and an RGB primary color system or Y, M, C complementary color system color filter can be obtained. In the case of a color filter, the amount of the azo pigment of the present invention is not limited, but is preferably 0.1 to 50% by mass.

The thermosetting resin, quinonediazide compound, cross-linking agent, and solvent used in this case and the amounts used thereof are preferably those described in the above-mentioned patent documents.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the examples, “parts” represents parts by mass.

The X-ray diffraction of the pigment composition of the present invention is measured using CuKα rays with a powder X-ray diffraction measurement device RINT2500 (manufactured by Rigaku Corporation) in accordance with Japanese Industrial Standard JISK0131 (general rules for X-ray diffraction analysis). The test was performed under the following conditions.

Measuring instrument used: Automatic X-ray diffractometer RINT2500 manufactured by Rigaku
X-ray tube: Cu
Tube voltage: 55KV
Tube current: 280 mA
Scanning method: 2θ / θ scan Scanning speed: 6 deg. / Min.
Sampling interval: 0.100 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 55 deg.
Divergence slit: 2 deg.
Scattering slit: 2 deg.
Resiping slit: 0.6mm
Using vertical goniometer

[Synthesis Example 1] Synthesis of azo pigment composition (1) A synthesis scheme of the azo pigment (1) is shown below.

(1) Synthesis of Intermediate (a) 29.7 g (0.3 mol) of methyl cyanoacetate, 42.4 g (0.4 mol) of trimethyl orthoformate, 20.4 g (0.2 mol) of acetic anhydride, p- Toluenesulfonic acid 0.5 g was added and heated to 110 ° C. (external temperature), and the mixture was stirred for 20 hours while distilling off low-boiling components generated from the reaction system. The reaction solution was concentrated under reduced pressure, and then purified on a silica gel column to obtain 14.1 g of the intermediate (a) (yellow powder, yield 30%). The NMR measurement result of the obtained intermediate (a) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) 7.96 (s, 1H), 4.15 (s, 3H), 3.81 (s, 3H)

(2) Synthesis of Intermediate (b) 150 mL of isopropanol was added to 7.4 mL (141 mmol) of methyl hydrazine and cooled to 15 ° C. (internal temperature), and 7.0 g (49. 6 mmol) was gradually added, and the mixture was heated to 50 ° C. and stirred for 1 hour and 40 minutes. The reaction solution was concentrated under reduced pressure, and then purified on a silica gel column to obtain 10.5 g of the intermediate (b) (white powder, yield 50%). The NMR measurement result of the obtained intermediate (b) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) 7.60 (s, 1H), 4.95 (brs, 2H), 3.80 (s, 3H), 3.60 (s, 3H)

(3) Synthesis of Intermediate (c) 136 mL of water was added to 1.1 L of methanol, 182 g (2.17 mol) of sodium hydrogen carbonate was added, and the mixture was stirred at room temperature. At the same temperature, 200 g (1.08 mol) of cyanuric chloride was added in portions. After the addition, the internal temperature was raised to 30 ° C. After stirring at the same temperature for 30 minutes, 500 mL of water was added, the precipitated solid was separated by filtration, washed with 500 mL of water and 300 mL of methanol, dried, and 168 g of the intermediate (c) (white powder, yield) 86.2%). The NMR measurement result of the obtained intermediate (c) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) 4.14 (s, 3H)

(4) Synthesis of Intermediate (d) 673 mL of water was added to 363 mL (7.46 mol) of hydrazine monohydrate and cooled to 10 ° C. (internal temperature), and 168 g (934) of Intermediate (c) was added to this mixture. Millimoles) was gradually added (internal temperature of 20 ° C. or lower), the ice bath was removed, the temperature was raised to room temperature, and the mixture was stirred at the same temperature for 30 minutes. The crystals precipitated from the reaction solution were collected by filtration, washed with 700 mL of water and 1 L of acetonitrile, and then dried to obtain a crude product (white powder) of the intermediate (d).

(5) Synthesis of intermediate (e) 480 mL of ethylene glycol was added to the crude product of intermediate (d) and stirred at room temperature. To this suspension, 257 g (2.06 mol) of pivaloyl acetonitrile was added and heated until the internal temperature reached 50 ° C. After dropwise addition of 12M aqueous hydrochloric acid at the same temperature to pH 3, the mixture was heated to an internal temperature of 80 ° C. and stirred for 3 hours. After completion of the reaction, the mixture was ice-cooled and cooled to an internal temperature of 8 ° C. The precipitated crystals were collected by filtration, washed with water, and purified by silica gel column. 105g of the intermediate (e) (white powder, 2 steps) (Yield 29.2%). The NMR measurement result of the obtained intermediate (e) is as follows.
¹ H-NMR (300 MHz, d-DMSO) 7.00 (s, 4H), 5.35 (s, 2H), 4.05 (s, 3H), 5.35 (s, 2H), 1.22 (S, 18H)

(6) Synthesis of azo pigment (1) A mixture of 125 mL of acetic acid and 24 mL of sulfuric acid was ice-cooled, and the internal temperature was cooled to 3 ° C. At the same temperature, 26.4 g of nitrosylsulfuric acid was added, and subsequently, 11.6 g of intermediate (b) was dividedly added and dissolved at the same temperature. After stirring for 1 hour at the same temperature, 1.2 g of urea was added in portions at the same temperature and stirred for 15 minutes at the same temperature to obtain a diazonium salt solution. Separately, 11.6 g of the intermediate (e) was completely dissolved in 405 mL of methanol at room temperature, and ice-cooled to cool the internal temperature to -3 ° C. At the same temperature, the above-described diazonium salt solution was added in portions so that the internal temperature was 3 ° C. or less, and stirred for 2 hours after the addition was completed. After removing the ice bath and stirring at room temperature for 10 minutes, the precipitated crystals were separated by filtration, washed with 150 mL of methanol, and further washed with 100 mL of water. The obtained crystals were suspended in 750 mL of water without drying, and 8N aqueous potassium hydroxide solution was added to adjust the pH to 5.7. After stirring at room temperature for 20 minutes, the obtained crystals were separated by filtration, thoroughly washed with water, and then washed with 80 mL of methanol. The obtained crystal was dried at room temperature for 12 hours.

The obtained crystals were suspended in a mixed solution of 180 mL of dimethylacetamide and 180 mL of water, and then the internal temperature was raised to 85 ° C. and stirred at the same temperature for 2 hours. Thereafter, the obtained crystals were filtered off with heating, suspended in 300 mL of methanol, and stirred at room temperature for 30 minutes. The obtained crystals were separated by filtration and dried at room temperature for 5 hours to obtain 19.5 g of azo pigment (1). Yield 90.3%.
The obtained azo pigment (1) was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope). The length of the primary particles in the major axis direction was about 150 nm. It was.
When the X-ray diffraction measurement of the azo pigment (1) was carried out under the above-mentioned conditions, the Bragg angles (2θ ± 0.2 °) showed characteristic X-ray diffraction peaks at 7.2 ° and 25.9 °. It was.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 2] Synthesis of azo pigment composition (2) A synthesis scheme of the azo pigment (2) is shown below.

(7) Synthesis of intermediate (a) 29.7 g (0.3 mol) of methyl cyanoacetate, 42.4 g (0.4 mol) of trimethyl orthoformate, 20.4 g (0.2 mol) of acetic anhydride, p- Toluenesulfonic acid 0.5 g was added and heated to 110 ° C. (external temperature), and the mixture was stirred for 20 hours while distilling off low-boiling components generated from the reaction system. The reaction solution was concentrated under reduced pressure, and then purified on a silica gel column to obtain 14.1 g of the intermediate (a) (yellow powder, yield 30%). The NMR measurement result of the obtained intermediate (a) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) 7.96 (s, 1H), 4.15 (s, 3H), 3.81 (s, 3H)

(8) Synthesis of Intermediate (b) 150 mL of isopropanol was added to 7.4 mL (141 mmol) of methyl hydrazine and cooled to 15 ° C. (internal temperature), and 7.0 g (49. 6 mmol) was gradually added, and the mixture was heated to 50 ° C. and stirred for 1 hour and 40 minutes. The reaction solution was concentrated under reduced pressure, and then purified on a silica gel column to obtain 10.5 g of the intermediate (b) (white powder, yield 50%). The NMR measurement result of the obtained intermediate (b) is as follows.
¹ H-NMR (300 MHz, CDCl ₃ ) 7.60 (s, 1H), 4.95 (brs, 2H), 3.80 (s, 3H), 3.60 (s, 3H)

(9) Synthesis of Intermediate (c ′) 298 mL of methanol was added to 387 mL (7.98 mol) of hydrazine monohydrate and cooled to 10 ° C. (internal temperature), and 149 g of 4,6-dichloropyrimidine was added to this mixture. (1.00 mol) was gradually added (internal temperature 20 ° C. or lower), the ice bath was removed, the temperature was raised to room temperature, and the mixture was stirred at the same temperature for 30 minutes. Thereafter, the mixture was further heated to raise the internal temperature to 60 ° C. and stirred at the same temperature for 5 hours. After completion of the reaction, 750 mL of water was added, and the mixture was cooled with ice and cooled to an internal temperature of 8 ° C. The precipitated crystals were collected by filtration, washed with water, and washed with isopropanol. It dried at room temperature for 36 hours, and obtained the said intermediate body (c ') by 119g (white powder, yield 84.5%). The NMR measurement result of the obtained intermediate (c ′) is as follows.
¹ H-NMR (300 MHz, d-DMSO) 7.80 (s, 1H), 7.52 (s, 2H), 5.98 (s, 1H), 4.13 (s, 4H)

(10) Synthesis of Intermediate (d ′) To 50 g (357 mmol) of Intermediate (c ′), 128 mL of water was added and stirred at room temperature. To this suspension, 98.2 g (785 mmol) of pivaloylacetonitrile was added, and 12M hydrochloric acid was added dropwise at the same temperature to pH 3, and then heated until the internal temperature reached 50 ° C. For 6 hours. After completion of the reaction, the solution was neutralized by adding 8N aqueous potassium hydroxide solution to pH 6.4. The mixture was cooled with ice and cooled to an internal temperature of 10 ° C., and the precipitated crystals were collected by filtration and washed with water. The obtained crystal was dried at 60 ° C. under reduced pressure, and 30 mL of toluene was added to the obtained crude product, and heated to 60 ° C. for dissolution. The resulting solution was allowed to stand at room temperature for 12 hours, and the precipitated crystals were collected by filtration, washed with cooled toluene and dried at 60 ° C. under reduced pressure to obtain 87.7 g (white color) of the intermediate (d ′). Powder, yield 69.3%). The NMR measurement results of the obtained intermediate (d ′) are as follows.
¹ H-NMR (300 MHz, d-DMSO) 8.74 (s, 1H), 7.99 (s, 1H), 6.87 (s, 4H), 5.35 (s, 2H), 1.24 (S, 18H)

(11) Synthesis of azo pigment (2)

9.2 g of intermediate (b) was dissolved in a mixed solution of 55 mL of acetic acid and 37 mL of propionic acid at room temperature. The inner temperature was cooled to −3 ° C. with ice cooling, and a 40 mass% sulfuric acid solution of nitrosylsulfuric acid was added dropwise over 10 minutes at an inner temperature of −3 ° C. to 4 ° C. After stirring for 1 hour at an internal temperature of 4 ° C., 0.2 g of urea was added, and then the internal temperature was cooled to −3 ° C. and further stirred for 10 minutes to obtain a diazonium salt solution. Separately, 10 g of intermediate (d ′) was completely dissolved in 150 mL of acetone, then the internal temperature was cooled to 17 ° C. and added to the above diazonium salt solution within the range of −3 ° C. to 3 ° C. over 25 minutes. did. After completion of the addition, the mixture was stirred at 3 ° C. for 30 minutes, then the ice bath was removed and the temperature was raised to room temperature over 30 minutes. After stirring at room temperature for 30 minutes, the obtained crystals were separated by filtration, washed with 150 mL of acetone, and further washed with 100 mL of water. The obtained crystals were suspended in 400 mL of water without drying, and 8N aqueous potassium hydroxide solution was added to adjust the pH to 5.7. After stirring at room temperature for 20 minutes, the obtained crystals were separated by filtration, thoroughly washed with water, and then washed with 80 mL of acetone. The obtained crystal was dried at room temperature for 12 hours.

The obtained crystals were suspended in 580 mL of acetone and then stirred for 30 minutes under reflux. Then, it cooled to room temperature over 10 minutes, the obtained crystal was separated by filtration, and it was made to dry at room temperature for 5 hours, and 17.1g of azo pigments (2) were obtained. Yield 88.5%.
The obtained azo pigment (2) was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of the primary particles in the major axis direction was about 15 μm. It was.
When the X-ray diffraction measurement of the azo pigment (2) was performed under the above conditions, characteristic X-ray diffraction peaks were observed at Bragg angles (2θ ± 0.2 °) of 7.6 ° and 25.6 °. Indicated. A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 3] Synthesis of α-type crystal form azo pigment (1) -1 A synthesis scheme of α-type crystal form azo pigments (1) -1 to (1) -12 is shown below.

(6) Synthesis of α-type crystal form azo pigment (1) -1 20.5 mL of acetic acid was ice-cooled to an internal temperature of 10 ° C. 16.8 g of nitrosylsulfuric acid was added so that the internal temperature was 15 ° C. or lower, and 9.5 g of intermediate (b) was added in portions so that the internal temperature was 15 ° C. or lower. After stirring at an internal temperature of 15 ° C. for 15 minutes, the temperature was raised to an internal temperature of 25 ° C. over 15 minutes. After stirring for 90 minutes at the same temperature, 0.4 g of urea was added in portions at the same temperature and stirred for 15 minutes at the same temperature to obtain a diazonium salt solution.
Separately, 11.6 g of the intermediate (e) was completely dissolved in 405 mL of methanol at room temperature, and ice-cooled to cool the internal temperature to -3 ° C. At the same temperature, the above-mentioned diazonium salt solution was added in portions so that the internal temperature would be 3 ° C. or less, and stirred for 2 hours after the addition was completed to obtain an azo compound reaction solution. Separately, 810 mL of water was prepared, and an azo compound reaction solution was added. The mixture was stirred at room temperature for 30 minutes, and the precipitated crystals were collected by filtration, washed with 150 mL of methanol, and further washed with 100 mL of water. The obtained crystals were suspended in 750 mL of water without drying, and 8N aqueous potassium hydroxide solution was added to adjust the pH to 5.7. After stirring at room temperature for 20 minutes, the obtained crystals were separated by filtration, thoroughly washed with water, and then washed with 80 mL of methanol to obtain a crude pigment (1-1). The obtained crude pigment (1-1) was dried at room temperature for 12 hours to obtain a crude pigment (1-2).
When the obtained crude pigment (1-2) was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), the length of the primary particles in the major axis direction was about 40. It was ˜500 nm.
When the X-ray diffraction of the crude pigment (1-2) was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 ° and 25. A characteristic X-ray diffraction peak was observed at 9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

10 g of the obtained crude pigment (1-2) was suspended in 100 mL of 2-propanol, and then stirred for 2 hours under reflux. Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.2 g of an α-type crystal form azo pigment (1) -1 represented by the formula (1) having the crystal form of the present invention. (Yield 92.0%).
The obtained α-type crystal form azo pigment (1) -1 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 40-180 nm.
When the X-ray diffraction of the α-type crystal form pigment (1) -1 was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 4] Synthesis of α-type crystal form azo pigment (1) -2 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in a mixed solvent of 50 mL of 2-propanol and 50 mL of water, The mixture was stirred at an internal temperature of 78 ° for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.5 g of an α-type crystal form azo pigment (1) -2 represented by the formula (1) having the crystal form of the present invention. (Yield 95.0%).
The obtained α-type crystal form azo pigment (1) -2 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of the primary particles in the long axis direction was observed. Was about 40-160 nm.
When the X-ray diffraction measurement of the α-type crystal form pigment (1) -2 was performed under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 5] Synthesis of α-type crystal form azo pigment (1) -3 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 200 mL of 2-methyl-1-propanol, the internal temperature The mixture was stirred at 80 ° C. for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.3 g of an α-type crystal form azo pigment (1) -3 represented by the formula (1) having the crystal form of the present invention. (Yield 93.0%).
The obtained α-type crystal form azo pigment (1) -3 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 30-140 nm.
When the X-ray diffraction of the α-type crystal form pigment (1) -3 was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 6] Synthesis of α-type crystal form azo pigment (1) -4 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 50 mL of 2-methyl-1-propanol and 50 mL of water. The mixture was stirred at an internal temperature of 80 ° C. for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.3 g of an α-type crystal form azo pigment (1) -4 represented by the formula (1) having the crystal form of the present invention. (Yield 93.0%).
The obtained α-type crystal form azo pigment (1) -4 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 40-120 nm.
When the X-ray diffraction of the α-type crystal form pigment (1) -4 was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 7] Synthesis of α-type crystal form azo pigment (1) -5 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 25 mL of 2-methyl-1-propanol and 75 mL of water. The mixture was stirred at an internal temperature of 80 ° C. for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.3 g of an α-type crystal form azo pigment (1) -5 represented by the formula (1) having the crystal form of the present invention. (Yield 93.0%).
The obtained α-type crystal form azo pigment (1) -5 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 30-110 nm.
When the X-ray diffraction measurement of the α-type crystal form pigment (1) -5 was carried out under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 8] Synthesis of α-type crystal form azo pigment (1) -6 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 200 mL of water and then stirred at 80 ° C for 2 hours. .
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.6 g of an α-type crystal form azo pigment (1) -6 represented by the formula (1) having the crystal form of the present invention. (Yield 96.0%).
The obtained α-type crystal form azo pigment (1) -6 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 30-150 nm.
When the X-ray diffraction of the α-type crystal form pigment (1) -6 was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 9] Synthesis of α-type crystal form azo pigment (1) -7 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 200 mL of acetone and stirred for 2 hours under reflux.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 8.5 g of α-type crystal form azo pigment (1) -7 represented by the formula (1) having the crystal form of the present invention. (Yield 85.0%).
The obtained α-type crystal form azo pigment (1) -7 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 60-190 nm.
When the X-ray diffraction of the α-type crystal form pigment (1) -7 was measured under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 10] Synthesis of α-type crystal form azo pigment (1) -8 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in a mixed solvent of 100 mL of acetone and 100 mL of water, the internal temperature The mixture was stirred at 60 ° C. for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.0 g of an α-type crystal form azo pigment (1) -8 represented by the formula (1) having the crystal form of the present invention. (Yield 90.0%).
The obtained α-type crystal form azo pigment (1) -8 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 50-160 nm.
When the X-ray diffraction measurement of the α-type crystal form pigment (1) -8 was performed under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 11] Synthesis of α-type crystal form azo pigment (1) -9 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in 100 mL of methanol and stirred for 2 hours under reflux.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.2 g of an α-type crystal form azo pigment (1) -9 represented by the formula (1) having the crystal form of the present invention. (Yield 92.0%).
The obtained α-type crystal form azo pigment (1) -9 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the major axis direction was observed. Was about 50-140 nm.
When the X-ray diffraction measurement of the α-type crystal form pigment (1) -9 was performed under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Synthesis Example 12] Synthesis of α-type crystal form azo pigment (1) -10 After 10 g of the crude pigment (1-2) obtained in Synthesis Example 3 was suspended in a mixed solvent of 100 mL of methanol and 100 mL of water, the internal temperature The mixture was stirred at 70 ° C. for 2 hours.
Thereafter, the obtained crystals were filtered off with heating and dried at room temperature for 12 hours to obtain 9.4 g of an α-type crystal form azo pigment (1) -10 represented by the formula (1) having the crystal form of the present invention. (Yield 94.0%).
The obtained α-type crystal form azo pigment (1) -10 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 40-130 nm.
When the X-ray diffraction measurement of the α-type crystal form pigment (1) -10 was performed under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 °. And characteristic X-ray diffraction peaks at 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG. 13.

[Synthesis Example 13] Synthesis of α-type crystal form azo pigment (1) -11 433.3 g of 43% nitrosylsulfuric acid was ice-cooled and the internal temperature was cooled to 10 ° C.
Acetic acid (60 mL) was added so that the internal temperature was 15 ° C. or lower, and then 25 g of intermediate (b) was added in portions so that the internal temperature was 15 ° C. or lower.
After stirring at an internal temperature of 15 ° C. for 15 minutes, the temperature was raised to an internal temperature of 25 ° C., and the mixture was stirred at the same temperature for 90 minutes.
Thereafter, 0.9 g of urea was dividedly added at the same temperature and stirred for 15 minutes at the same temperature to obtain a diazonium salt solution.
Separately, 30.3 g of intermediate (e) was suspended in 518 mL of methanol at room temperature, and the internal temperature was cooled to 15 ° C.
At the same temperature, the above diazonium salt solution was added so that the internal temperature was 30 ° C. or lower.
After completion of the addition, the mixture was stirred for 2 hours to obtain an azo compound reaction liquid.
Separately, 810 mL of water was prepared, and an azo compound reaction solution was added.
After stirring at room temperature for 30 minutes, 8N aqueous sodium hydroxide solution was added to adjust the pH to 6.0.
Thereafter, the stirring was stopped and the mixture was allowed to stand for 12 hours. The supernatant was removed, and the same amount of water as the removed amount was added, followed by stirring for 30 minutes.
After repeating this operation three times, the temperature was raised to an internal temperature of 80 ° C., and the mixture was stirred at the same temperature for 2 hours.
Thereafter, the mixture was filtered while heated, washed with 1 L of water, and then dried under reduced pressure at room temperature for 24 hours to obtain 53.4 g (yield 97.1%) of α-type crystal form azo pigment (1) -11. )
The obtained α-type crystal form azo pigment (1) -11 was visually observed with a transmission microscope (manufactured by JEOL Ltd .: JEM-1010 electron microscope), and the length of primary particles in the long axis direction was observed. Was about 60-250 nm.
When the X-ray diffraction measurement of the α-type crystal form azo pigment (1) -11 was carried out under the above conditions, the Bragg angle (2θ ± 0.2 °) was 7.2 °, 13.4 °, 15.0 Characteristic X-ray diffraction peaks were exhibited at ° and 25.9 °.
A CuKα characteristic X-ray diffraction diagram is shown in FIG.

[Example 1] Preparation of Pigment Dispersion 1 2.5 parts of the azo pigment (1) synthesized in Synthesis Example 1 were mixed with 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water. Dispersion was performed at 300 rpm for 2 hours using a planetary ball mill together with 100 parts of 1 mm zirconia beads. After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 1 (average particle size; Mv≈64 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 2 Preparation of Pigment Dispersion 2 2.25 parts of the azo pigment (1) synthesized in Synthesis Example 1 and 0.25 parts of the azo pigment composition (2) synthesized in Synthesis Example 2 and sodium oleate 0.5 parts, 5 parts of glycerin and 42 parts of water were mixed, and dispersed with 300 parts per minute for 3 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After the dispersion, the zirconia beads were separated, and the yellow pigment dispersion 2 (average particle size; Mv≈68 nm: Nanotrac 150 manufactured by Nikkiso Co., Ltd.)
(Measured using UPA-EX150).

[Example 3] Preparation of pigment dispersion 3 2.0 parts of the azo pigment (1) synthesized in Synthesis Example 1, 0.5 part of the azo pigment composition (2) synthesized in Synthesis Example 2, and sodium oleate 0.5 parts, 5 parts of glycerin and 42 parts of water were mixed, and dispersed with 300 parts per minute for 3 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 3 (average particle size; Mv≈67 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

[Example 4] Preparation of pigment dispersion 4 1.5 parts of the azo pigment (1) synthesized in Synthesis Example 1, 1.0 part of the azo pigment composition (2) synthesized in Synthesis Example 2, and sodium oleate 0.5 parts, 5 parts of glycerin and 42 parts of water were mixed, and dispersed with 300 parts per minute for 3 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 4 (average particle size; Mv≈66 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

[Example 5] Preparation of pigment dispersion 5 1.25 parts of the azo pigment (1) synthesized in Synthesis Example 1 and 1.25 parts of the azo pigment composition (2) synthesized in Synthesis Example 2 and sodium oleate 0.5 parts, 5 parts of glycerin and 42 parts of water were mixed, and dispersed with 300 parts per minute for 3 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After completion of the dispersion, the zirconia beads were separated, and a yellow pigment dispersion 5 (average particle diameter; Mv≈69 nm: Nanotrac 150 manufactured by Nikkiso Co., Ltd.)
(Measured using UPA-EX150).

Example 6 Preparation of Pigment Dispersion 6 0.25 part of the azo pigment (1) synthesized in Synthesis Example 1, 2.25 parts of the azo pigment composition (2) synthesized in Synthesis Example 2, and sodium oleate 0.5 parts, 5 parts of glycerin and 42 parts of water were mixed, and dispersed at 300 rpm for 2 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After completion of the dispersion, the zirconia beads were separated, and a yellow pigment dispersion 6 (average particle size; Mv≈70 nm: Nanotrac 150 manufactured by Nikkiso Co., Ltd.)
(Measured using UPA-EX150).

Example 7 Preparation of Pigment Dispersion 7 The α-type crystal form azo pigment (1) -1 synthesized in Synthesis Example 3 was 2.0 parts, and the azo pigment composition (2) synthesized in Synthesis Example 2 was 0. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 7 (volume average particle diameter; Mv≈68 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 8 Preparation of Pigment Dispersion 8 The α-type crystal form azo pigment (1) -6 synthesized in Synthesis Example 8 was 2.0 parts, and the azo pigment composition (2) synthesized in Synthesis Example 2 was 0. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 8 (volume average particle diameter; Mv≈70 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 9 Preparation of Pigment Dispersion 9 The α-type crystal form azo pigment (1) -7 synthesized in Synthesis Example 9 was 2.0 parts, and the azo pigment composition (2) synthesized in Synthesis Example 2 was added in an amount of 0.0. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 9 (volume average particle diameter; Mv≈69 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 10 Preparation of Pigment Dispersion 10 2.0 parts of the α-type crystal form azo pigment (1) -8 synthesized in Synthesis Example 10 and 0.2 parts of the azo pigment composition (2) synthesized in Synthesis Example 2 were added. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 10 (volume average particle diameter; Mv≈79 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 11 Preparation of Pigment Dispersion 11 2.0 parts of the α-type crystal form azo pigment (1) -9 synthesized in Synthesis Example 11 and 0.02 of the azo pigment composition (2) synthesized in Synthesis Example 2 were prepared. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 11 (volume average particle diameter; Mv≈71 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 12 Preparation of Pigment Dispersion 12 The α-type crystal form azo pigment (1) -10 synthesized in Synthesis Example 12 was 2.0 parts, and the azo pigment composition (2) synthesized in Synthesis Example 2 was added in an amount of 0.0. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 12 (volume average particle diameter; Mv≈65 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 13 Preparation of Pigment Dispersion 13 2.0 parts of the α-type crystal form azo pigment (1) -11 synthesized in Synthesis Example 13 and 0.2 parts of the azo pigment composition (2) synthesized in Synthesis Example 2 were added. 5 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water are mixed and dispersed with 300 parts per minute using planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 1 hour and 30 minutes. It was.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 13 (volume average particle diameter; Mv≈87 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Example 14 Preparation of Pigment Dispersion 14 2.25 parts of the α-type crystal form azo pigment (1) -11 synthesized in Synthesis Example 13 and 0.2 mg of the azo pigment composition (2) synthesized in Synthesis Example 2. 25 parts, 0.5 part of sodium oleate, 5 parts of glycerin and 42 parts of water were mixed, and dispersion was performed at 300 rpm for 2 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm.
After completion of the dispersion, the zirconia beads were separated to obtain a yellow pigment dispersion 14 (volume average particle diameter; Mv≈68 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

[Example 15] Preparation of pigment dispersion 15 2.0 parts of crude pigment (1-2) synthesized in Synthesis Example 3, 0.5 part of azo pigment composition (2) synthesized in Synthesis Example 2 and olein 0.5 parts of sodium acid, 5 parts of glycerin and 42 parts of water were mixed, and dispersed with 300 parts per minute and 1 hour 30 minutes using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm.
After completion of the dispersion, zirconia beads were separated to obtain a yellow pigment dispersion 15 (volume average particle diameter; Mv≈79 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.).

Comparative Example 1 Preparation of Comparative Pigment Dispersion 1 In place of the azo pigment composition (1) used in Example 1, C.I. I. A yellow comparative pigment dispersion 1 was obtained in the same manner as in Example 1 except that CI Pigment Yellow 74 (Iralite YELLOW GO manufactured by Ciba Specialty) was used.

Comparative Example 2 Preparation of Comparative Pigment Dispersion 2 In place of the azo pigment composition (1) used in Example 1, C.I. I. A yellow comparative pigment dispersion 2 was obtained in the same manner as in Example 1 except that CI Pigment Yellow 155 (INKJET YELLOW 4G VP2532 manufactured by Clariant) was used.

[Comparative Example 3] Preparation of Comparative Pigment Dispersion 3 In place of the azo pigment composition (1) and the azo pigment composition (2) used in Example 3, C.I. I. Pigment Yellow 74 (Iralite YELLOW GO manufactured by Ciba Specialty) and C.I. I. A yellow comparative pigment dispersion 3 was obtained in the same manner as in Example 3 except that CI Pigment Yellow 155 (INKJET YELLOW 4G VP2532 manufactured by Clariant) was used in combination.

[Comparative Example 4] Preparation of Comparative Dispersion 4 Example 1 except that the compound (DYE-1) represented by the following formula (A) was used instead of the azo pigment composition (1) used in Example 1. In the same manner as above, it was dissolved and could not be dispersed.

<Dispersibility>
Mix 2.5 parts of pigment, 0.5 part of sodium oleate, 5 parts of glycerin, and 42 parts of water, and use a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm for 2 hours dispersion for 2 hours. As a result, the pigment dispersions 1 to 6 of the present invention and the comparative pigment dispersions 1 to 6 were evaluated as xx for those that could not be dispersed, x for those in which coarse particles of 100 nm or more were confirmed, and ◯ for those that were hardly confirmed. 3 and Comparative Dispersion 4 were evaluated. The results are shown in Table 2.

<Dispersion stability>
The pigment dispersions obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were allowed to stand at room temperature for 4 weeks. As a result, the case where the precipitate was visually confirmed was rated as x, and the case where the precipitate was not confirmed was marked as ◯. The results are shown in Table 2.

<Evaluation of coloring power>
The pigment dispersions obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were designated 3 was applied to a photomat paper manufactured by Epson. The image density of the obtained coated product was measured using a reflection densitometer (X-Rite 938 manufactured by X-Rite), and the “coloring power (OD)” was evaluated according to the following criteria. The case where the OD was 1.4 or more was rated as 、, the case where it was 1.2 or more and less than 1.4, the case where it was 1.0 or more and less than 1.2, Δ, and the case where it was less than 1.0, ×. The results are shown in Table 2.

<Hue evaluation>
Regarding the hue, ◎ (good) if the chromaticity of the coated material obtained above is visually green and large vividness, ◯ if either one does not apply, and one that does not apply either Evaluation was performed as x (defect). The results are shown in Table 2.

<Light fastness evaluation>
A coated material having an image density of 1.0 used for hue evaluation was prepared, xenon light (99000 lux; in the presence of a TAC filter) was irradiated for 35 days using a fade meter, and the image density before and after the xenon irradiation was measured using a reflection densitometer. When the dye residual ratio [(concentration after irradiation / concentration before irradiation) × 100%] is 80% or more, ◯, when 60% or more and less than 80%, Δ, and when less than 60%, Pigment dispersions 1 to 6 and comparative pigment dispersions 1 to 3 were evaluated. The results are shown in Table 2.

<Ozone gas fastness evaluation>
A coating with an image density of 1.0 used for hue evaluation was prepared, exposed to an ozone concentration of 5.0 ppm at 25 ° C. and a humidity of 50% for 35 days, and the image density before and after exposure to ozone gas was measured using a reflection densitometer. Pigment dispersion 1 where the residual dye ratio [(post-irradiation density / pre-irradiation density) × 100%] is 80% or more, ◯ is 70% or more and less than 80%, and x is less than 70%. To 6 and comparative pigment dispersions 1 to 3 were evaluated. The results are shown in Table 2.
For example, “(1) / (2) = 9/1” in the table represents that the azo pigment composition (1) and the azo pigment composition (2) were used at a mass ratio of 9: 1.

From these results, it was confirmed that the pigment dispersion using the azo pigment composition of the present invention is easily dispersible and the stability of the pigment dispersion is good. Furthermore, it has been found that the coloring composition containing the pigment dispersion of the present invention is excellent in hue as yellow, has high coloring power, and is excellent in light resistance and ozone gas resistance.
Further, Example 1 using the azo pigment (1) alone, Example 2 using the mass ratio of the azo pigment (1) and the azo pigment (2) 9: 1, and Example 14 are particularly excellent in coloring power. It was found that in Examples 4 to 6 and Example 15 in which the azo pigment (1) and the azo pigment (2) were used in a mass ratio of 6: 4 to 1: 9, the hue and light resistance were particularly excellent. In Example 3, Example 7 to Example 13, and Example 15 used at a mass ratio of azo pigment (1) and azo pigment (2) of 8: 2, coloring power, hue and light resistance are particularly excellent. all right.
Therefore, the pigment dispersion coloring composition containing the azo pigment composition of the present invention is used in, for example, printing ink such as inkjet, color toner for electrophotography, display such as LCD and PDP, and imaging element such as CCD. Can be suitably used for color filters, paints, colored plastics and the like.

ADVANTAGE OF THE INVENTION According to this invention, the azo pigment which is excellent in color characteristics, such as coloring power and a hue, is excellent also in the dispersibility and dispersion stability. By dispersing the pigment of the present invention in various media, a pigment dispersion having excellent color characteristics, dispersibility and dispersion stability can be obtained. The pigment dispersion is a color product excellent in light fastness, for example, a printing ink such as an inkjet, a color toner for electrophotography, a color filter used in an image pickup device such as a display such as an LCD or PDP, or a CCD, It can be used for paints, colored plastics, etc.
Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on a Japanese patent application filed on December 9, 2008 (Japanese Patent Application No. 2008-313755) and a Japanese patent application filed on December 7, 2009 (Japanese Patent Application No. 2009-278057). Incorporated herein by reference.

Claims

An azo pigment or a tautomer represented by the following formula (1) having X-ray diffraction peaks characteristic of Bragg angles (2θ ± 0.2 °) of 7.2 ° and 25.9 ° in CuKα characteristic X-ray diffraction An azo pigment composition comprising at least one kind of active substance.
Further, the composition has X-ray diffraction peaks having characteristic Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.6 °, 25.6 ° and 27.7 °. The azo pigment composition according to claim 1, wherein the azo pigment composition or tautomer represented by (2) is contained in an amount of 0.1% by mass or more and less than 99% by mass.
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to claim 2, wherein the azo pigment or tautomer is contained in an amount of 1% by mass or more and less than 70% by mass.
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to claim 2 or 3, wherein the azo pigment or tautomer is contained in an amount of 5% by mass or more and less than 45% by mass.
The Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction is expressed by the above formula (2) having characteristic X-ray diffraction peaks at 7.6 °, 25.6 °, and 27.7 °. The azo pigment composition according to any one of claims 2 to 4, comprising an azo pigment or a tautomer in an amount of 15% by mass or more and less than 30% by mass.
A pigment dispersion containing the azo pigment composition according to any one of claims 1 to 5.
The pigment dispersion according to claim 6, wherein the volume average particle diameter of the pigment particles in the pigment dispersion is 0.01 µm to 0.2 µm.
A colored composition comprising the pigment composition according to any one of claims 1 to 5 as a colorant.
An ink for inkjet recording comprising the pigment composition according to any one of claims 1 to 5 as a colorant.