JP2009275112A - Azo pigment, pigment dispersion product, coloring composition, inkjet-recording ink and azo compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an azo pigment which excels in color properties such as coloring power and hue and also excels in the durability of light resistance, ozone resistance and the like. <P>SOLUTION: The azo pigment is represented by formula (1) (wherein G is an aliphatic group, an aryl group or a heterocyclic group; Y is hydrogen or an aliphatic group; R<SB>1</SB>is an aliphatic group, an aryl group, an aliphatic amino group, an arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamide group or the like; R<SB>2</SB>is an aliphatic amino group, an arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group; X<SB>1</SB>is nitrogen or C-Z; Z is an electron-attracting group having a Hammett σp value of not smaller than 0.2; n is an integer of 1-4; in the case of n=2, the formula is a dimer through R<SB>1</SB>, R<SB>2</SB>, Y, Z or G; in the case of n=3, the formula is a trimer through R<SB>1</SB>, R<SB>2</SB>, Y, Z or G; and in the case of n=4, the formula is a tetramer through R<SB>1</SB>, R<SB>2</SB>, Y, Z or G) and includes its tautomer, a salt or a hydrate thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel nitrogen-containing heterocyclic azo pigment, a pigment dispersion containing the azo pigment, a coloring composition, an ink for inkjet recording, and an azo compound.

  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 mixture method and subtractive color mixture method are used to display or record full color images. In fact, there is no fast-acting dye that has absorption characteristics that can realize the above-mentioned conditions and can withstand various use conditions and environmental conditions, and improvement is 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 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 it is difficult to achieve both because they are in a trade-off relationship.
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 pigments that have a good hue, have high coloring power among light, wet heat, and active gases in the environment, and are 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 defects, 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 3). 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.

  Patent Document 4 discloses a dye having an absorption characteristic excellent in color reproducibility and sufficient fastness. However, since all of the specific compounds described in the patent document are dissolved in water or an organic solvent, the chemical fastness is not sufficient.

  When expressing a full color using a subtractive color mixing method with three colors of yellow, magenta, and cyan, or four colors with black added, if a pigment with only one color is inferior in color fastness, 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 thermal transfer materials, inkjet inks, and color filter dyes. 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.
A conventionally known azo dye having a nitrogen-containing 5-membered ring as an azo component is also disclosed in Patent Document 5.
JP-A-56-38354 U.S. Pat. No. 2,936,306 Japanese Patent Laid-Open No. 11-1000051 Japanese Patent Laying-Open No. 2005-215286 JP-A-55-161856

  An object of the present invention is to provide an azo pigment, an azo pigment dispersion, a colored composition, an ink jet recording ink, and an azo pigment which have excellent color characteristics such as coloring power and hue, and excellent durability such as light resistance and ozone resistance. It is to provide a compound.

  As a result of intensive studies, the present inventors have obtained the knowledge that a specific nitrogen-containing heterocyclic azo pigment has a good hue and exhibits good fastness to light, heat and ozone. . Specific means for solving the above problems will be described below.

[1]
An azo pigment represented by the following general formula (1), a tautomer thereof, a salt or a hydrate thereof.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)
[2]
A pigment dispersion comprising at least one azo pigment, a tautomer thereof, a salt or a hydrate thereof according to [1].
[3]
A coloring composition comprising at least one azo pigment according to [1], a tautomer thereof, a salt or a hydrate thereof.
[4]
An ink for inkjet recording, comprising the pigment dispersion according to [2].
[5]
An azo compound represented by the following general formula (2), a tautomer thereof, a salt or a hydrate thereof.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)

The azo pigment of the present invention is excellent in color characteristics such as coloring power and hue, and is excellent in durability such as light resistance and ozone resistance.
Further, the azo compound of the present invention is excellent in hue even in a molecular state and has a high molecular extinction coefficient (ε).
Furthermore, the pigment dispersion, coloring composition, and ink jet recording ink of the present invention are obtained by dispersing the azo pigment of the present invention in various media, and are excellent in color characteristics, durability, and dispersion stability.

First, the aliphatic group, aryl group, heterocyclic group and substituent in the present invention will be described.
In the aliphatic group in the present invention, the aliphatic moiety may be linear, branched or cyclic. Moreover, it may be saturated or unsaturated. Specific examples include an alkyl group, an alkenyl group, a cycloalkyl group, and a cycloalkenyl group. Furthermore, the aliphatic group may be unsubstituted or may have a substituent.

  The aryl group may be a single ring or a condensed ring. Further, it may be unsubstituted or may have a substituent. Moreover, the heterocyclic group should just have a hetero atom (for example, a nitrogen atom, a sulfur atom, an oxygen atom) in the ring, and even if it is a saturated ring, it is an unsaturated ring. Also good. Further, it may be a single ring or a condensed ring, and may be unsubstituted or have a substituent.

  Further, the substituent in the present invention may be any group that can be substituted. For example, an aliphatic group, an aryl group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aryloxy group, a hetero group Ring oxy group, aliphatic oxycarbonyl group, aryloxycarbonyl group, heterocyclic oxycarbonyl group, carbamoyl group, aliphatic sulfonyl group, arylsulfonyl group, heterocyclic sulfonyl group, aliphatic sulfonyloxy group, arylsulfonyloxy group, hetero Ring sulfonyloxy group, sulfamoyl group, aliphatic sulfonamide group, aryl sulfonamide group, heterocyclic sulfonamide group, amino group, aliphatic amino group, arylamino group, heterocyclic amino group, aliphatic oxycarbonylamino group, aryl Oxycarbonylamino group, heterocycle Xoxycarbonylamino group, aliphatic sulfinyl group, arylsulfinyl group, aliphatic thio group, arylthio group, hydroxy group, cyano group, sulfo group, carboxy group, aliphatic oxyamino group, aryloxyamino group, carbamoylamino group, sulfo group Famoylamino group, halogen atom, sulfamoylcarbamoyl group, carbamoylsulfamoyl group, dialiphatic oxyphosphinyl group, diaryloxyphosphinyl group, ionic hydrophilic group (for example, carboxyl group, sulfo group, Phosphono group and quaternary ammonium group).

  When the azo pigment of the present invention contains an ionic hydrophilic group as a substituent, it is preferably a salt with a polyvalent metal cation (for example, a salt of magnesium, calcium, barium, etc.), and is a lake pigment. Is particularly preferred.

Here, Hammett's substituent constant σp value used in the present specification will be described briefly.
Hammett's rule is a method described in 1935 in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include a σp value and a σm value, and these values can be found in many general books. A. Dean, “Lange's Handbook of Chemistry”, 12th edition, 1979 (Mc Graw-Hill) and “Chemicals” special edition, 122, 96-103, 1979 (Nankodo). In the present invention, each substituent is limited or explained by Hammett's substituent constant σp, but this means that it is limited to only a substituent having a value known in the literature, which can be found in the above-mentioned book. Needless to say, even if the value is unknown, it includes a substituent that would be included in the range when measured based on Hammett's rule. Although the compound represented by the general formula (1) or (2) of the present invention is not a benzene derivative, the σp value is used as a scale indicating the electronic effect of the substituent regardless of the substitution position. In the present invention, the σp value will be used in this sense.

<Azo pigment>
A pigment is a state in which molecules are firmly bonded to each other by cohesive energy due to strong interaction between dye molecules. In order to create this state, it is described in, for example, Journal of Imaging Society of Japan, Vol. 43, page 10 (2004) that van der Waals force between molecules and hydrogen bonding between molecules are necessary.
In order to increase the van der Waals force between molecules, introduction of an aromatic group, a polar group and / or a hetero atom into the molecule can be considered. In order to form an intermolecular hydrogen bond, introduction of a substituent containing a hydrogen atom bonded to a hetero atom and / or introduction of an electron donating substituent into the molecule can be considered. Further, it is considered preferable that the polarity of the whole molecule is high. For this purpose, for example, a shorter chain group such as an alkyl group is preferred, and a smaller molecular weight / azo group value is preferred.

  From these viewpoints, the pigment molecule preferably contains an amide bond, a sulfonamide bond, an ether bond, a sulfone group, an oxycarbonyl group, an imide group, a carbamoylamino group, a hetero ring, a benzene ring and the like.

The azo pigment of the present invention is represented by the following general formula (1). By having a specific structure represented by the following general formula (1), it exhibits excellent characteristics in color characteristics such as tinting strength and hue, and also has excellent durability such as light resistance and ozone resistance. Can be shown.
Next, the pigment represented by the general formula (1) will be described.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)

The aliphatic group represented by G may have a substituent, may be saturated or unsaturated, and the group that may be substituted is described in the above-mentioned substituent group. Any group can be used as long as it can be substituted. The aliphatic group represented by G is preferably an aliphatic group having 1 to 8 carbon atoms in total, and more preferably an alkyl group having 1 to 4 carbon atoms in total. Preferred examples of the aliphatic group include methyl, ethyl, vinyl, cyclohexyl, carbamoylmethyl and the like.
The aryl group represented by G may be condensed or may have a substituent, and the group that may be substituted is the group described in the above-mentioned substituent group. Any group is possible. The aryl group represented by G is preferably an aryl group having 6 to 12 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, such as phenyl, 4-nitrophenyl, 4-acetylamino. Phenyl, 4-methanesulfonylphenyl and the like.
The heterocyclic group represented by G may have a substituent, may be saturated or unsaturated, may be condensed, and preferably has 2 to 2 carbon atoms in total. A heterocyclic group bonded by 12 carbon atoms, more preferably an unsaturated 5-6 membered heterocyclic ring having 2 to 10 total carbon atoms bonded by carbon atoms, and more preferably a total bonded by carbon atoms An unsaturated 5- to 6-membered heterocycle having 2 to 10 carbon atoms and having a nitrogen atom adjacent to the pyrazole ring, such as 2-tetrahydrofuryl, 2-furyl, 2-pyrrolyl, 2 -Thiazolyl, 2-benzothiazolyl, 2-oxazolyl, 2-benzoxazolyl, 2-pyridyl, 2-pyrazinyl, 3-pyridazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 2-imidazolyl, 2-benzimidazolyl, 2 -A triazinyl etc. are mentioned, These heterocyclic groups may be a tautomer structure with a substituent. As the group which may be substituted on the heterocyclic group of G, any group can be used as long as it can be substituted with the group described in the above-mentioned substituent group, but preferably an aliphatic group, an aryl group, a hydroxy group A halogen atom, an aliphatic oxy group, an aliphatic thio group, an optionally substituted amino group, a carbamoylamino group, an acylamino group, a sulfonamide group, a carbamoyl group, a sulfamoyl group, and the like, more preferably an aliphatic group Group, hydroxy group, aliphatic oxy group, aliphatic thio group, optionally substituted amino group, carbamoylamino group, acylamino group, carbamoyl group and the like.

  The aliphatic group represented by Y may have a substituent, may be saturated or unsaturated, and the group that may be substituted with the aliphatic group of Y is as described above. Any group can be used as long as it is a group that can be substituted with the groups described in the section of the substituent. The aliphatic group represented by Y is preferably an alkyl group having 1 to 8 carbon atoms in total, and more preferably an alkyl group having 1 to 6 carbon atoms in total. Preferred examples of the aliphatic group include methyl, ethyl, vinyl, cyclohexyl, (t) -butyl, carbamoylmethyl and the like.

The aliphatic group represented by R ₁ may have a substituent, may be saturated or unsaturated, and the group that may be substituted includes the above-mentioned substituent group. Any group can be used as long as it is a substitutable group. The aliphatic group for R ₁ is preferably an alkyl group having 1 to 8 carbon atoms in total, and more preferably an alkyl group having 1 to 6 carbon atoms in total. Examples of the aliphatic group include methyl, ethyl, i-propyl, cyclohexyl, t-butyl and the like.

The aryl group represented by R ₁ may be condensed, may have a substituent, and the group that may be substituted is the group described in the above-mentioned substituent group, Any group that can be substituted is acceptable. The aryl group represented by R ₁ is preferably an aryl group having 6 to 12 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, such as phenyl, 4-chlorophenyl, 4-acetyl. Aminophenyl, 4-methanesulfonylphenyl, etc. are mentioned.
The aliphatic amino group represented by R ₁ and R ₂ may have a substituent, may be saturated or unsaturated, and examples of the group that may be substituted include those described above. Any group can be used as long as it is a group that can be substituted among the groups described in the section of the substituent. The aliphatic amino group for R ₁ and R ₂ is preferably an aliphatic amino group having 1 to 10 carbon atoms, more preferably an alkylamino group having 1 to 6 carbon atoms, such as methylamino, Examples include ethylamino, dimethylamino, diethylamino, methoxyethylamino and the like. The aliphatic amino group represented by R ₁ is preferably an aliphatic amino group having 1 to 8 carbon atoms in which a hydrogen atom is bonded to the amino group, and more preferably a hydrogen atom is bonded to the amino group. An alkylamino group having 1 to 6 carbon atoms in total, for example, methylamino, ethylamino, methoxyethylamino, acetylaminoethylamino and the like. The aliphatic amino group represented by R ₂ is preferably a dialiphatic amino group having 2 to 8 carbon atoms in total, more preferably a dialkylamino group having 2 to 6 carbon atoms, such as dimethyl, diethylamino, and dimethoxyethyl. Amino, N-acetylaminoethyl-N-methylamino and the like can be mentioned.

The arylamino group represented by R ₁ and R ₂ may have a substituent, and the group that may be substituted is a group that can be substituted with the groups described in the above-mentioned substituents section. Anything is acceptable. The arylamino group of R ₁ and R ₂ is preferably an arylamino group having 6 to 16 carbon atoms in total, more preferably an arylamino group having 6 to 12 carbon atoms in total, such as anilino, 4-acetyl Aminoanilino, N-methyl-3-methoxyanilino, 3-carbamoylanilino, 3-carbamoylaminoanilino and the like can be mentioned. The arylamino group represented by R ₁ is preferably an arylamino group having 6 to 16 total carbon atoms in which hydrogen atoms are bonded to the amino group, and more preferably a total carbon in which hydrogen atoms are bonded to the amino group. An arylamino group having 6 to 12 atoms such as anilino, 3,4-benzimidazoloneanilino, 4-acetylaminoanilino and the like. The arylamino group represented by R ₂ is preferably a diarylamino group having 6 to 16 carbon atoms in total, and examples thereof include diphenylamino.

The heterocyclic amino group represented by R ₁ and R ₂ may have a substituent, may be saturated or unsaturated, and examples of the group that may be substituted include those described above. Any group can be used as long as it is a group that can be substituted among the groups described in the section of the substituent. The heterocyclic amino group for R ₁ and R ₂ is preferably a heterocyclic amino group having 2 to 16 carbon atoms in total, more preferably a 5- to 6-membered heterocyclic amino group having 2 to 12 carbon atoms in total. Examples thereof include 2-pyridylamino, 2-pyrimidylamino, 2-pyrrolidinylamino and the like. The heterocyclic amino group represented by R ₁ is preferably a heterocyclic amino group having 2 to 16 carbon atoms in which a hydrogen atom is bonded to the amino group, more preferably a hydrogen atom bonded to the amino group. A heterocyclic amino group having 2 to 12 carbon atoms in total, such as 2-pyridylamino and 2-pyrimidylamino. The heterocyclic amino group represented by R ₂ is preferably a diheterocyclic amino group having 2 to 16 carbon atoms in total, and examples thereof include di2-pyridylamino.

The acylamino group represented by R ₁ and R ₂ may have a substituent, and may be aliphatic, aromatic, heterocyclic, or substituted. As the good group, any group can be used as long as it is a group that can be substituted with the groups described in the section of the substituent. The acylamino group for R ₁ and R ₂ is preferably an acylamino group having 2 to 12 total carbon atoms, more preferably an acylamino group having 2 to 8 total carbon atoms, and still more preferably 2 to 2 carbon atoms. 8 alkylcarbonylamino groups such as acetylamino, pivaloylamino, benzoylamino, 2-pyridinecarbonylamino, propanoylamino and the like.
The sulfonamide group represented by R ₁ and R ₂ may have a substituent, and may be aliphatic, aromatic, heterocyclic, or substituted. As the good group, any group can be used as long as it is a group which can be substituted with the groups described in the above-mentioned substituent group. The sulfonamide group of R ₁ and R ₂ is preferably a sulfonamide group having 1 to 12 carbon atoms, more preferably a sulfonamide group having 1 to 8 carbon atoms, and still more preferably a total carbon atom. Examples of the alkylsulfonamide group having 1 to 8 include methanesulfonamide, benzenesulfonamide, and 2-pyridinesulfonamide.
The heterocyclic group represented by R ₁ and R ₂ may have a substituent, may be saturated or unsaturated, may be condensed, or may be substituted. As the good group, any group can be used as long as it is a group that can be substituted with the groups described in the section of the substituent. The heterocyclic group for R ₁ is preferably a heterocyclic group having 2 to 16 carbon atoms in total, more preferably a 5 to 6-membered heterocyclic group having 2 to 12 carbon atoms in total, such as 2- The R ₂ heterocyclic group such as pyridyl, 4-pyridyl, 2-pyrimidyl, 1-pyrrolidinyl and the like is preferably a heterocyclic group bonded with a nitrogen atom having 2 to 16 total carbon atoms, more preferably a total carbon atom. It is a heterocyclic group bonded by a 5-6 membered nitrogen atom of 2 to 12, and examples thereof include 1-piperidyl, 4-morpholinyl and the like.
The carbamoylamino group represented by R ₁ may have a substituent, and may be aliphatic, aromatic, heterocyclic, or a group that may be substituted. Can be any group as long as it is a group that can be substituted with the groups described in the above-mentioned substituent group. The carbamoylamino group for R ₁ is preferably a carbamoylamino group having 1 to 12 carbon atoms, more preferably a carbamoylamino group having 1 to 8 carbon atoms, and still more preferably 1 to 1 carbon atoms. 8 alkylcarbamoylamino groups such as carbamoylamino, methylcarbamoylamino, phenylcarbamoylamino, 2-pyridinecarbamoylamino, dimethylcarbamoylamino and the like.
The sulfamoylamino group represented by R ₁ may have a substituent, and may be aliphatic, aromatic, heterocyclic, or substituted. As the group, any group may be used as long as it is a group that can be substituted with the groups described in the above-mentioned substituent group. The sulfamoylamino group for R ₁ is preferably a sulfamoylamino group having 0 to 12 carbon atoms, more preferably a sulfamoylamino group having 0 to 8 carbon atoms, still more preferably. Examples of the alkylsulfamoylamino group having 0 to 8 carbon atoms in total include, for example, sulfamoylamino, dimethylsulfamoylamino and the like.

  In the general formula (1), Z is an electron-withdrawing group having a Hammett's substituent constant σp value of 0.2 or more, and preferably an electron-withdrawing group having a σp value of 0.30 or more. The upper limit is 1.0 or less electron withdrawing group.

  Specific examples of Z, which is an electron withdrawing group having a σp value of 0.20 or more, include an acyl group, an acyloxy group, a carbamoyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a cyano group, a nitro group, and a dialkylphosphono group. Group, diarylphosphono group, diarylphosphinyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonyloxy group, acylthio group, sulfamoyl group, thiocyanate group, thiocarbonyl group, halogenated alkyl group , Halogenated alkoxy groups, halogenated aryloxy groups, halogenated alkylamino groups, halogenated alkylthio groups, aryl groups substituted with other electron-withdrawing groups having a σp value of 0.20 or more, heterocyclic groups, halogens Atoms, azo groups, or selenocyanes Group.

Z preferably represents a cyano group, a carbamoyl group, an aliphatic oxycarbonyl group, a carboxyl group or a sulfonyl group.
The carbamoyl group represented by Z may have a substituent, and the group which may be substituted may be any group as long as it can be substituted with the groups described in the above-mentioned substituent group. . The carbamoyl group for Z is preferably a carbamoyl group having 1 to 12 carbon atoms, more preferably a carbamoyl group having 1 to 7 carbon atoms, and still more preferably an unsubstituted group having 1 to 5 carbon atoms. Or an alkyl-substituted carbamoyl group, most preferably an unsubstituted carbamoyl group, and examples thereof include unsubstituted carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-ethylcarbamoyl and the like.
The aliphatic oxycarbonyl group represented by Z may have a substituent, and the group that may be substituted may be a group that can be substituted with the groups described in the above-mentioned substituents section. Anything is fine. The aliphatic oxycarbonyl group represented by Z is preferably an aliphatic oxycarbonyl group having 2 to 12 carbon atoms in total, more preferably an alkoxycarbonyl group having 2 to 8 carbon atoms in total, And methoxycarbonyl, ethoxycarbonyl, carbamoylmethoxycarbonyl and the like.

The sulfonyl group represented by Z may have a substituent, may be aliphatic, aromatic, or heterocyclic, and examples of the substituent include the substituents described above. Any group can be used as long as it is a group described in the above section and can be substituted. The sulfonyl group represented by Z is preferably an alkylsulfonyl group having 2 to 12 carbon atoms in total, more preferably an alkylsulfonyl group having 2 to 8 carbon atoms in total, such as methanesulfonyl or ethanesulfonyl. N is preferably 1, 2 or 3, more preferably 1 or 2.

In view of the effects of the present invention, G in the general formula (1) is preferably an aryl group or a heterocyclic group, and more preferably a heterocyclic group. In view of the effect of the present invention, Y in the general formula (1) is preferably a hydrogen atom. In view of the effect of the present invention, R ₁ in the general formula (1) is an aliphatic group, an aryl group, an aliphatic amino group, an arylamino group, a heterocyclic amino group, an acylamino group, a carbamoylamino group or a heterocyclic group. Of these, an aliphatic group, an aryl group, an aliphatic amino group, an acylamino group, and an arylamino group are more preferable. In view of the effect of the present invention, R ₂ in the general formula (1) is preferably an aliphatic amino group, an arylamino group, an amino group or a heterocyclic group, and is preferably an aliphatic amino group, an arylamino group or a heterogeneous group. The case of a cyclic group is more preferred, and the case of an alkylamino group, an arylamino group or a heterocyclic group is still more preferred.
In view of the effect of the present invention, X ₁ in the general formula (1) is preferably C—Z, and Z is more preferably a cyano group, a carbamoyl group or an aliphatic oxycarbonyl group, and is a carbamoyl group. The case is more preferable.

In the general formula (1), G is preferably the following (G-1) to (G-13), and the following (G-1), (G-4), (G-5), (G -6), (G-7), and (G-12) are more preferable, and the following (G-1), (G-4), (G-6), and (G-12) Further preferred. * In the general formulas (G-1) to (G-13) represents a bonding site with the N atom of the pyrazole ring. Y _{1 to} Y ₁₁ represent a hydrogen atom or a substituent. G ₁₁ in (G-13) represents a nonmetallic atom group that can form a 5- to 6-membered heterocycle, and the heterocycle represented by G ₁₁ has a substituent even if it is unsubstituted. The heterocycle may be monocyclic or condensed. Formulas (G-1) to (G-13) may have tautomeric structures together with substituents.

  In terms of the effects of the present invention, the pigment represented by the general formula (1) preferably has a “total carbon number / the number of azo groups” of 40 or less, and more preferably 30 or less. In terms of the effect of the present invention, the pigment represented by the general formula (1) preferably has a “molecular weight / number of azo groups” of 600 or less. From the viewpoint of the effect of the present invention, the pigment represented by the general formula (1) is preferably not substituted with an ionic substituent such as a sulfo group or a carboxyl group.

In the pigment represented by the general formula (1) in terms of the effects of the present invention, G is a heterocyclic group, Y is a hydrogen atom or an aliphatic group, R ₁ is an alkyl group, an aryl group, an aliphatic group. An aromatic amino group, an arylamino group, a heterocyclic amino group, an acylamino group, a carbamoylamino group or a heterocyclic group, wherein R ₂ is an aliphatic amino group, an arylamino group, a heterocyclic amino group or a heterocyclic group; X ₁ is C—Z, Z is a cyano group or a carbamoyl group, and n is 1 or 2.
In terms of the effects of the present invention, in the pigment represented by the general formula (1), Y is a hydrogen atom, R ₁ is an alkyl group, an aryl group, an alkylamino group, or an acylamino group, and R ₂ is An alkylamino group, an arylamino group, or a heterocyclic group, wherein X ₁ is C—Z, Z is a carbamoyl group, and a heterocyclic ring of G is represented by (G-1), (G-4) It is more preferable that it is (G-7) or (G-12), and n is 1 or 2.
In terms of the effects of the present invention, in the pigment represented by the general formula (1), Y is a hydrogen atom, R ₁ is an alkyl group, an alkylamino group, or an acylamino group, and R ₂ is an alkylamino group. , An arylamino group or a saturated heterocyclic group, wherein X ₁ is C—Z, Z is a carbamoyl group, and the heterocyclic ring of G is (G−1), (G-4), (G More preferably, it is −6) or (G-12), and n is 1 or 2.

The present invention includes within its scope tautomers of the azo pigments represented by the general formula (1). The general formula (1) is shown in the form of an extreme structural formula among several tautomers that can be taken in terms of chemical structure, but may be a tautomer other than the structure described, You may use as a mixture containing these tautomers.
For example, the pigment represented by the general formula (1) may be an azo-hydrazone tautomer represented by the following general formula (1 ′).
The present invention includes in its scope a compound represented by the following general formula (1 ′), which is a tautomer of the azo pigment represented by the general formula (1).

In general formula (1 ′), G, R ₂ , Y, Z, and X ₁ are the same as those defined in general formula (1). In general formula (1 ′), R ₁ ′ is a group corresponding to R ₁ defined in general formula (1).

  The pigment represented by the general formula (1) is preferably an azo pigment represented by the following general formula (2).

  Hereinafter, the azo pigment represented by the general formula (2), a tautomer thereof, a salt or a hydrate thereof will be described in detail.

(In General Formula (2), G, R ₂ and n are the same as defined in General Formula (1). Z ₁ represents a hydrogen atom or a substituent, and Z ₂ represents an oxygen atom, a sulfur atom or NR. _Z represents R ₁ ″ together with XH represents a group corresponding to R ₁ defined in the general formula (1), and represents a substitutable group therein. Rz represents a hydrogen atom or a substitutable substituent. To express.)

In the azo pigment represented by the general formula (1), an azo-hydrazone tautomer may be considered. Among the azo pigments represented by the general formula (1), examples of the particularly preferred azo pigments represented by the general formula (1) include azo pigments represented by the above general formula (2).
As a factor that this structure is preferable, as shown in the general formula (2), at least a nitrogen atom, a hydrogen atom, and a hetero atom (oxygen atom of carbonyl group or nitrogen atom of amino group) constituting Z contained in the azo pigment structure are at least It is easy to form one or more intramolecular hydrogen bonds (intramolecular hydrogen bonds). As a result, the planarity of the molecule is increased, the intramolecular / intermolecular interaction is further improved, and the crystallinity of the azo pigment represented by the general formula (2) is increased (it is easy to form a higher order structure), This is the most preferable example because the light fastness, heat stability, wet heat stability, water resistance, gas resistance and / or solvent resistance, which are required performance as a pigment, are greatly improved.

<Azo compound>
The present invention also relates to an azo compound represented by the general formula (1), a tautomer thereof, a salt or a hydrate thereof.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)

Examples of the salt, hydrate and tautomerism of the azo compound represented by the general formula (1) of the present invention include those similar to the azo pigment, hydrate and tautomerism of the present invention. .
The novel azo compound of the present invention is useful as an azo pigment.

  Specific examples of the azo pigment and azo compound represented by the general formula (1) are shown below, but the azo pigment used in the present invention and the azo compound of the present invention are not limited to the following examples. Absent. The structures of the following specific examples are shown in the form of an ultimate structural formula among several tautomers that can be taken in terms of chemical structure, but have tautomeric structures other than those described. Needless to say.

  The pigment represented by the general formula (1) of the present invention may have any chemical form as long as the chemical structural formula is the general formula (1) or a tautomer thereof, and may be any crystal form pigment also called polymorph.

  Crystal polymorphs refer to the same chemical composition but different arrangement of building blocks (molecules or ions) in the crystal. The crystal structure determines the chemical and physical properties, and each polymorph can be distinguished by its rheology, color, and other color characteristics. Different polymorphs can also be confirmed by X-Ray Diffraction (powder X-ray diffraction measurement results) and X-Ray Analysis (X-ray crystal structure analysis results). When a crystal polymorph exists in the pigment represented by the general formula (1) of the present invention, it may be any polymorph or a mixture of two or more polymorphs.

  The tautomerism and / or crystal polymorphism described above can be controlled by the production conditions during the coupling reaction.

  In the present invention, when the azo pigment represented by the general formula (1) has an acid group, a part or all of the acid group may be in a salt form. Acid type pigments may be mixed. Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts optionally substituted with an alkyl group or hydroxyalkyl group, and organic amine salts. Examples of organic amines include lower alkyl amines, hydroxy-substituted lower alkyl amines, carboxy-substituted lower alkyl amines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

  Further, in the structure of the pigment used in the present invention, when a plurality of acid groups are contained in one molecule, the plurality of acid groups may be salt type or acid type and may be different from each other.

  In the present invention, the azo pigment represented by the general formula (1) may be a hydrate containing water molecules in the crystal.

  Next, an example of a method for producing the azo pigment represented by the general formula (1) will be described. For example, the heterocyclic amine represented by the following general formula (3) is diazonium with non-aqueous acidity, and a coupling reaction is performed with a compound represented by the following general formula (4) in an acidic state, followed by post-treatment by a conventional method. Then, an azo pigment represented by the above general formula (1) can be produced by performing a reaction such as alkylation, arylation, and heterylation.

(In the formula, Y and X ₁ have the same meaning as defined in the general formula (1).)

(In the formula, R ₁ and R ₂ have the same meaning as defined in the general formula (1).)

  The reaction scheme is shown below.

(In the formula, G, Y, R ₁ , R ₂ and X ₁ are synonymous with those defined in the general formula (1).)

Although some heterocyclic amines represented by the general formula (3) can be obtained as commercial products, they are generally produced by a known and commonly used method, for example, the method described in Japanese Patent No. 4022221. be able to. The heterocyclic coupler represented by the general formula (4) can be produced by the method described in JP-A-60-228567 and JP-T-10-508047 and a method analogous thereto. The diazoniumation reaction of the heterocyclic amine represented by the above reaction scheme is carried out at a temperature of 15 ° C. or less with a reagent such as sodium nitrite, nitrosylsulfuric acid, isoamyl nitrite 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 minutes. The coupling reaction is performed by reacting the diazonium salt obtained by the above-described method with the compound represented by the general formula (4) at 40 ° C. or less, preferably 25 ° C. or less for about 10 minutes to 12 hours. Can do. Furthermore, G is introduced by bringing a compound substituted with a leaving group (preferably halogen, sulfonyl, etc.) into G, a solvent such as DMF or DMSO, and a base such as potassium carbonate or triethylamine at about 50 ° C. to 120 ° C. The reaction can be carried out by reacting for about 30 minutes to 5 hours.
The synthesis method in the case where n in the general formula (1) and the general formula (2) is 2 or more is the R ₁ , R ₂ , G, Y, X ₁ or the like in the general formula (3) or the general formula (4). A raw material into which a divalent, trivalent or tetravalent substituent that can be substituted is introduced can be synthesized and synthesized in the same manner as in the above scheme.
In some cases, crystals are precipitated in this way, but in general, water or an alcohol solvent is added to the reaction solution to precipitate the crystals, and the crystals can be collected by filtration. it can. In addition, an alcohol solvent, water or the like can be added to the reaction solution to precipitate crystals, and the precipitated crystals can be collected by filtration. The crystals collected by filtration can be washed and dried as necessary to obtain an azo pigment represented by the general formula (1).

  Although the compound represented by the general formula (1) is obtained as a crude azo pigment (crude) by the above production method, when used as the pigment of the present invention, it is desirable to perform post-treatment. Examples of post-treatment methods include solvent salt milling, salt milling, dry milling, solvent milling, pigment particle control step by grinding treatment such as acid pasting, solvent heating treatment, resin, surfactant and dispersant. The surface treatment process by etc. is mentioned.

The compound represented by the general formula (1) of the present invention is preferably subjected to solvent heat treatment and / or solvent salt milling as a post-treatment.
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 thereof include solvents, polar aprotic organic solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone, glacial acetic acid, pyridine, and mixtures thereof. 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.
As solvent salt milling, for example, a crude azo pigment, an inorganic salt, and an organic solvent that does not dissolve the crude azo pigment are charged into a kneader and kneaded and ground therein. As said inorganic salt, water-soluble inorganic salt can be used conveniently, For example, it is preferable to use inorganic salts, such as sodium chloride, potassium chloride, sodium sulfate. Moreover, 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, diethylene glycol 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 the 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 represented by the general formula (1), a tautomer, a salt or a hydrate thereof. 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 Polyhydric 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.

  Further, the aqueous pigment dispersion of the present invention may contain an aqueous resin. Examples of the aqueous resin include a water-soluble resin that dissolves in water, a water-dispersible resin that disperses in water, a colloidal dispersion resin, or a mixture thereof. Specific examples of the aqueous resin include acrylic, styrene-acrylic, polyester, polyamide, polyurethane, and fluorine resins.

  When the aqueous pigment dispersion in the present invention contains an aqueous resin, the content is not particularly limited. For example, it can be 0 to 100% by mass with respect to the pigment.

  In addition, surfactants and dispersants may be used to improve pigment dispersion and image quality. Examples of the surfactant include anionic, nonionic, cationic and amphoteric surfactants, and any surfactant may be used, but anionic or nonionic surfactants may be used. It is preferable to use it.

  When the aqueous pigment dispersion in the present invention contains a surfactant, the content is not particularly limited. For example, it can be 0 to 100% by mass with respect to the pigment.

  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 fatty acid Examples include esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, fluorine-based materials, and silicon-based materials.

  The non-aqueous pigment dispersion of the present invention is obtained by dispersing the pigment represented by the general formula (1) 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, N 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.

  In the present invention, the volume average particle diameter of the pigment is preferably 10 nm or more and 250 nm or less. 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 pigment. 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 the pigment. The measurement was performed according to a predetermined measuring method by putting 3 ml of the pigment dispersion in a measuring cell. As parameters to be input at the time of measurement, ink viscosity was used as the viscosity, and pigment density was used as the density of the dispersed particles.

  A more preferable volume average particle diameter is 20 nm or more and 250 nm or less, and further preferably 30 nm or more and 230 nm or less. When the number average particle size of the particles in the pigment dispersion is less than 20 nm, there are cases where the storage stability cannot be ensured, whereas 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, and 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.

  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.

  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.

  The present invention can also 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 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 the application 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 colored composition of the present invention means a colored composition containing at least one azo pigment of the present invention. 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 a foaming agent, a viscosity modifier, a dispersant, a dispersion stabilizer, a rust inhibitor, and a chelating agent can be used. 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 for inkjet recording]
Next, the ink for inkjet recording of the present invention will be described.
The pigment dispersion described above is used for the inkjet recording ink of the present invention (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 of the present invention is preferably in the range of 1 to 100% by mass in consideration of the hue, color density, saturation, transparency and the like of the image formed on the recording medium. The range of mass% is particularly preferable, and the range of 3 to 10 mass% is most preferable among them.

  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 in 100 parts by mass of the ink of the present invention. It is more preferable to contain 10 parts by mass. 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 of the present invention can be used not only for monochromatic image formation but also for full color image formation. 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 of the present invention, other pigments can be used simultaneously in addition to the azo pigment of 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 magenta pigments that can be applied 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 can be mentioned, and apart from these, any one can be used. Applicable black materials include disazo, trisazo, and tetraazo pigments, as well as carbon black dispersions.

As the water-soluble solvent used in the ink jet recording ink of the present invention, polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, alcohols, sulfur-containing solvents and the like are used.
Specific examples of 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.

Preferred physical properties of the ink for ink jet recording of 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 components described above, water is added to the ink in the range of 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 ejection improvement, 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.
In addition, a pH buffer, an antioxidant, a fungicide, a viscosity modifier, a conductive agent, an ultraviolet absorber, and the like can be added as necessary.

  EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. Hereinafter, “parts” means parts by mass.

[Synthesis Example 1]
(Synthesis of Specific Compound Example D-1)
Specific compound example D-1 was synthesized by the following route.

Synthesis of D-1 ′ 1.5 g of compound (1) was dissolved in 15 ml of phosphoric acid. This solution was ice-cooled and kept at -5 to 0 ° C., 0.6 g of sodium nitrite was added and stirred for 1 hour to obtain a diazonium salt solution. To this diazonium salt solution, 1.8 g of compound (2) was added, the ice bath was removed, and the mixture was further stirred for 2 hours. The reaction solution was poured into 100 ml of water, a solution of 10 g of sodium hydroxide dissolved in 50 ml of water was added with stirring at 25 ° C. or lower, and the mixture was stirred for 30 minutes. The precipitated crystals were separated by filtration and washed with 50 ml of water to obtain 1.8 g of intermediate (D-1 ′). The yield was 60%.
To 1.5 g of the intermediate compound (D-1 ′), 20 ml of dimethylacetamide, 1.5 g of potassium carbonate, and 1.8 g of 2-chlorobenzothiazole were added and stirred at 90 ° C. for 2 hours. The reaction solution was returned to room temperature, added to 100 ml of ice water containing 3 ml of acetic acid, and stirred at room temperature for 1 hour. The precipitated crystals were separated by filtration and washed with 100 ml of water. The obtained crystals were added to 30 ml of dimethylacetamide without drying, dissolved by heating, 30 ml of water was added dropwise with stirring at 50 ° C., and the mixture was further stirred for 30 minutes. Thereafter, the mixture was stirred for 1 hour under air cooling, and the precipitated crystals were separated by filtration, washed with 15 ml of dimethylacetamide / water = 1/1, and further washed with 30 ml of water. The crystals were dried to obtain 1.1 g of a specific compound example (D-1) of the present invention. The yield based on D-1 ′ was 53.1%. FIG. 1 shows an infrared absorption chart.

[Example 1]
Specific Example Compound D-1 pigment 2.5 parts, sodium oleate 0.5 part, glycerin 5 parts, water 42 parts are mixed, and each 100 parts of zirconia beads having a diameter of 0.1 mm are used with a planetary ball mill. Dispersion was performed at 300 rpm for 6 hours. After the completion of dispersion, zirconia beads were separated to obtain pigment dispersion 1.

[Example 2]
Methacrylic acid-methacrylic acid ester represented by Dispersant Solution 10 described on page 22 of International Publication No. WO06 / 064193 as a polymeric dispersant, 5 parts of pigment (D-1) synthesized in Example 1 25.5 parts of an aqueous copolymer solution and 19.5 parts of water were mixed, and dispersion was performed at 300 rpm for 6 hours using a planetary ball mill together with 100 parts of zirconia beads having a diameter of 0.1 mm. After the completion of dispersion, zirconia beads were separated to obtain pigment dispersion 2.

[Comparative Example 1]
In place of the pigment of 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 128 (CROMOPHTAL YELLOW 8GN manufactured by Ciba Specialty) was used.

[Comparative Example 2]
Instead of the pigment (D-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 74 (Iralite YELLOW GO manufactured by Ciba Specialty) was used.

[Comparative Example 3]
Instead of the pigment (D-1) used in Example 1, C.I. I. A yellow comparative pigment dispersion 3 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.

(Evaluation)
<Dispersion stability>
The volume average particle size of the pigment dispersion obtained above was measured by a conventional method using a dynamic light scattering particle size measuring device (Nikkiso Microtrack UPA150). The volume average particle diameter measured 2 hours after preparing the pigment dispersion and the volume average particle diameter after storage at 70 ° C. for 2 days are both 230 nm or less (good), either of which is 230 nm or more X (defect). The results are shown in Table 1.
<Evaluation of coloring power>
The pigment dispersions obtained in the above Examples and Comparative Examples were No. No. 3 bar coater was applied to a photo mat paper <pigment only> manufactured by Seiko Epson Corporation. The image density of the obtained coated material was measured using a reflection densitometer (X-Rite 938 manufactured by X-Rite), and the result is shown in Table 1 as “coloring power (OD: Optical Density)”.
<Light resistance evaluation>
The coating with an image density of 1.0 used for hue evaluation was irradiated with xenon light (170000 lux .; in the presence of a cut filter of 325 nm or less) for 14 days using a fade meter, and the image density before and after the xenon irradiation was measured using a reflection densitometer. It was measured and evaluated as a dye residual ratio [(post-irradiation density / pre-irradiation density) × 100%]. The results are shown in Table 1.

[Examples 3 to 6]
Pigment dispersions 3 to 6 were prepared in the same manner except that the specific compound example D-1 of Example 1 was changed as shown in Table 1, and the same evaluation was performed.

Example 7
A polymer dispersant represented by Dispersant 10 described on page 22 of International Publication No. 06/064193 was neutralized with an aqueous potassium hydroxide solution. 30 parts by mass of the azo pigment (D-1) synthesized in Synthesis Example 1 and 95 parts by mass of ion-exchanged water were added to 75 parts by mass of the resulting aqueous dispersant solution (solid content concentration 20%), and a disper stirring blade was added. Mix and coarsely disperse with. 600 parts by mass of zirconia beads were added to the mixed and roughly dispersed liquid, and this was dispersed with a disperser (sand grinder mill) for 4 hours, and then separated into beads and a dispersion. While stirring the resulting mixture, 2 parts by mass of polyethylene glycol diglycidyl ether was slowly added at 25 ° C., and the mixture was stirred at 50 ° C. for 6 hours. Furthermore, impurities were removed using an ultrafiltration membrane having a fractional molecular number of 300K, and this was attached to a filter having a pore size of 5 μm (acetylcellulose membrane, outer diameter: 25 mm, manufactured by Fuji Film Co., Ltd.). By filtering with a syringe and removing coarse particles, a pigment dispersion 7 having a solid content concentration of 10% (particle diameter 80 nm: measured using Nanotrac 150 (UPA-EX150) manufactured by Nikkiso Co., Ltd.) was obtained.

[Comparative Example 4]
A comparison was made in the same manner as in Example 7 except that a yellow pigment (CI Pigment Yellow 128 (CROMOPHTAL YELLOW 8GN manufactured by Ciba Specialty) was used instead of the azo pigment (D-1) used in Example 7. A pigment dispersion 4 was obtained.

Example 8
5% by mass of the pigment dispersion 7 obtained in Example 7, 10% by mass of glycerin, 5% by mass of 2-pyrrolidone, 2% by mass of 1,2-hexanediol, 2% by mass of triethylene glycol monobutyl ether, Each component was added so that it might become 0.5 mass% of propylene glycol, and 75.5 mass% of ion-exchange water, and the obtained liquid mixture was filtered with a 1 μm pore size filter (acetylcellulose membrane, outer diameter: 25 mm, Fujifilm Corporation). The pigment ink liquid 1 shown in Table 2 was obtained by filtering with a syringe having a capacity of 20 ml equipped with a) and removing coarse particles.

[Comparative Example 5]
A comparative pigment ink liquid 1 was obtained in the same manner as in Example 8, except that the comparative pigment dispersion 4 obtained in Comparative Example 4 was used instead of the pigment dispersion 7 obtained in Example 7.

[Comparative Example 6]
Further, a PX-V630 yellow ink cartridge (comparative pigment ink liquid 2) manufactured by Epson Corporation was used as an ink comparison type.

  In Table 2, “Ejection stability”, “Light fastness”, “Heat fastness”, “Ozone fastness”, “Metal gloss”, and “Ink liquid stability” are the same for each ink. ) Installed in a yellow ink liquid cartridge of an inkjet printer PX-V630 manufactured by the company, PX-V630 pigment ink liquid was used for the other color inks, and the image receiving sheet was a photographic paper <gloss> manufactured by Seiko Epson Corporation. In addition, the photographic paper Krispia <High gloss> manufactured by Seiko Epson Co., Ltd. recommends a single-color image pattern and green, red, and gray image patterns in which the density changes in a staircase pattern, and the image quality and ink ejection properties. And image robustness were evaluated. Evaluations other than metallic luster were performed in a single color.

  The following evaluation was performed on the inkjet ink of Example 8 (pigment ink liquid 1) and comparative example (comparative pigment ink liquid 1 and yellow pigment ink liquid PX-V630; comparative pigment ink liquid 2). The results are shown in Table 2.

(Evaluation experiment)
1) About discharge stability, after setting a cartridge in a printer and confirming the protrusion of the ink from all the nozzles, 20 sheets of A4 were output and evaluated according to the following criteria.
A: No printing disturbance from the start to the end of printing B: Output with a printing disorder occurs C: There is a printing disturbance from the start to the end of printing

2) For image storage stability, the following evaluation was performed using a print sample.
[1] Light fastness is determined by measuring the image density Ci immediately after printing with X-rite 310 (manufactured by X-rite), and then irradiating the image with xenon light (100,000 lux) using an Atlas weather meter for 14 days. After that, the image density Cf was measured again, and the image remaining ratio Cf / Ci × 100 was obtained and evaluated.
The image afterimage rate is evaluated at three points of reflection density of 1, 1.5, and 2. A is the case when the image remaining rate is 80% or more at any density, and B is the case when the point is less than 80%. When the concentration was less than 80%, C was designated.

[2] For heat fastness, the density before and after storing the printed sample for 7 days under the condition of 80 ° C. and 60% RH was measured with X-rite 310, and the image residual ratio was determined and evaluated. The image afterimage rate is evaluated at three points of reflection density of 1, 1.5 and 2, and A is the case where the image remaining rate is 95% or more at any density, and B is the case where the point is less than 95%. The case where the concentration was less than 95% was defined as C.

[3] With regard to ozone resistance (ozone fastness), the sample was left in a box where the ozone gas concentration was set to 5 ppm (25 ° C; 50%) for 14 days, and the image density before and after being left under ozone gas was measured using a reflection densitometer (X -Measured using a Photographic Densitometer 310) manufactured by Rite and evaluated as an image residual ratio. The reflection density was measured at three points of 1, 1.5 and 2.0. The ozone gas concentration in the box was set using an ozone gas monitor (model: OZG-EM-01) manufactured by APPLICS.
The evaluation was made in three stages, with A as the case where the image remaining ratio was 80% or higher at any density, and B when 1 or 2 points were less than 80%, and C when less than 70% at all densities.

3) Presence or absence of occurrence of metallic luster: The yellow, green and red solid print portions were visually observed and evaluated with reflected light.
The case where the metallic luster was not visible was evaluated as “◯”, and the case where the metallic luster was visible was evaluated as “x”.

4) Ink liquid stability: After aging the pigment ink liquids of Examples and Comparative Examples at 60 ° C. for 10 days, no change in the particle diameter in the pigment ink liquid was evaluated as “◯”, and the change in the particle diameter was evaluated as “X”. did. The results are shown in Table 2 below.

From the results in Table 2, it was found that the pigment ink liquid using the pigment of the present invention was excellent in dischargeability and light resistance, suppressed the occurrence of metallic luster, and excellent in pigment ink liquid stability.
As is clear from the results in Table 2, it can be seen that the system using the ink of the present invention is excellent in all performance. In particular, light fastness and ink liquid stability are superior to the comparative example.

Example 9
An image of the pigment ink liquid prepared in Example 8 was printed on Fujifilm's inkjet paper photo glossy paper “Painting” using PX-V630 manufactured by Epson Corporation, and the same as in Example 8. When similar evaluations were made, similar results were obtained.

As is clear from the results of Tables 1 and 2, Pigment Dispersions 1 to 6 and 7 and the pigment ink liquid 1 using the pigment of the present invention are excellent in color tone and exhibit high coloring power and light resistance.
Therefore, the pigment dispersion using the pigment of the present invention can be suitably used for printing inks such as inkjet.

It is a figure of the infrared absorption spectrum of the specific compound example D-1 synthesize | combined according to the synthesis example 1. FIG.

Claims (5)

An azo pigment represented by the following general formula (1), a tautomer thereof, a salt or a hydrate thereof.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)   A pigment dispersion comprising at least one of the azo pigments according to claim 1, tautomers thereof, salts or hydrates thereof.   A coloring composition comprising at least one of the azo pigments according to claim 1, tautomers thereof, salts or hydrates thereof.   An ink for inkjet recording, wherein the pigment dispersion according to claim 2 is used. An azo compound represented by the following general formula (1), a tautomer thereof, a salt or a hydrate thereof.

(In General Formula (1), G represents an aliphatic group, an aryl group, or a heterocyclic group, Y represents a hydrogen atom or an aliphatic group. R ₁ represents an aliphatic group, an aryl group, an aliphatic amino group, An arylamino group, a heterocyclic amino group, an acylamino group, a sulfonamido group, a carbamoylamino group, a sulfamoylamino group, an amino group or a heterocyclic group, R ₂ represents an aliphatic amino group, an arylamino group, a heterocyclic ring An amino group, an acylamino group, a sulfonamide group, an amino group or a heterocyclic group, X ₁ represents a nitrogen atom or C—Z, and Z represents an electron withdrawing group having a Hammett σp value of 0.2 or more. N represents an integer of 1 to 4. When n = 2, it represents a dimer via R ₁ , R ₂ , Y, Z or G. When n = 3, R ₁ , R ₂ , Represents a trimer via Y, Z or G. When n = 4 Represents a tetramer via R ₁ , R ₂ , Y, Z or G.)

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