JP2009132747A - Graft type dispersant, and pigment composition using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispersant for obtaining a pigment composition excellent in dispersibility, flowability, and storage stability at a small using amount, and to provide a graft type dispersant which is excellent in a non-aggregating property and flowability, has good dispersibility and stability, and is suitable for offset inks, gravure inks, resist inks for color filters, ink-jet inks, coatings, colored resin compositions, and the like. <P>SOLUTION: Provided is the graft type dispersant prepared by addition-reacting 0.5 to 0.95 mole of carboxyl groups in a vinylic polymer (b) having one free carboxyl group in one end region to the total one mole of primary and secondary amino groups in a primary and/or secondary amino group-having polymer (a). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a graft type dispersant, and more particularly, a graft type capable of producing a pigment dispersion excellent in non-aggregation property, fluidity and storage stability, which is suitable for fields such as paints and colored resin compositions. The present invention relates to a dispersant and a pigment composition using the same.

  Generally, when manufacturing ink etc., it is known that it is difficult to disperse | distribute a pigment stably at high concentration, and it is known that it will cause various problems with respect to a manufacturing process or the product itself. For example, dispersions containing pigments composed of fine particles often exhibit high viscosity, making it difficult to remove and transport the product from the disperser, and if the increase in viscosity is significant, the May become difficult to use. Furthermore, regarding the surface of the color-extended product, a state failure such as a decrease in gloss and a leveling failure occurs. In addition, when different types of pigments are used in combination, color unevenness due to aggregation and phenomena such as sedimentation may cause uneven color and a marked reduction in coloring power.

  Therefore, in general, a dispersant is used in order to maintain a good dispersion state. The dispersant has a structure of a site that adsorbs to the pigment and a site that has a high affinity for the solvent that is the dispersion medium, and the performance of the dispersant is determined by the balance of these two functional sites. Various types of dispersants are used according to the surface state of the pigment to be dispersed, but basic dispersants are generally used for pigments having an acid-biased surface. is there. In this case, the basic functional group becomes the adsorption site of the pigment. Dispersants having an amino group as a basic functional group are described in, for example, Patent Literature 1, Patent Literature 2, Patent Literature 3, Patent Literature 4, Patent Literature 5, Patent Literature 6, and the like.

However, Patent Document 1, Patent Document 2, and Patent Document 3 have the dispersion ability, but the side chains are limited, and the usable solvents and binder resins are limited. Further, Patent Document 4, Patent Document 5, and Patent Document 6 have a certain degree of dispersion ability, but it was necessary to increase the amount of use in order to produce a stable dispersion with low viscosity. However, increasing the amount used is not preferable in view of development in inks, paints, etc., because the resistance of the coating film may be reduced.
Japanese Patent Laid-Open No. 9-169821 JP-A-9-194585 JP 2004-089787 A JP-A-1-236930 Japanese Patent Laid-Open No. 3-103478 Japanese Patent Laid-Open No. 16-344795

  An object of the present invention is to provide a dispersant for obtaining a pigment dispersion which is excellent in dispersibility, fluidity and storage stability at a low use amount and is not limited by a binder resin or a solvent. Furthermore, the present invention is suitable for offset inks, gravure inks, resist inks for color filters, ink jet inks, paints, and colored resin compositions, and can impart dispersibility and stability excellent in non-aggregability and fluidity. An object is to provide a graft type dispersant.

  As a result of intensive studies, the present inventors have found that a graft type dispersant obtained by addition-reacting a vinyl polymer as a side chain to an amino group-containing polymer solves the above-mentioned problems. The present invention has been completed.

That is, the first invention is based on a total of 1 mol of primary and secondary amino groups in the polymer (a) having primary and / or secondary amino groups.
The present invention relates to a graft type dispersant obtained by addition reaction of 0.5 to 0.95 mol of carboxyl groups in a vinyl polymer (b) having one free carboxyl group in one terminal region.

  The second invention relates to the graft type dispersant according to the first invention, wherein the polymer (a) having a primary and / or secondary amino group is polyethyleneimine or polyallylamine.

  In addition, the third invention is such that a vinyl polymer (b) having one free carboxyl group in one end region is present in the presence of a compound (b1) having one carboxyl group and one thiol group in the molecule. And the graft type dispersant of the first or second invention, wherein the ethylenically unsaturated monomer (b2) is radically polymerized.

  The fourth invention relates to the graft type dispersant according to the third invention, wherein the ethylenically unsaturated monomer (b2) contains methyl methacrylate.

  The fifth invention relates to the graft type dispersant according to the fourth invention, wherein the ethylenically unsaturated monomer (b2) further contains butyl methacrylate.

  The sixth invention is characterized in that the total of methyl methacrylate and butyl methacrylate is 30 to 100% by weight in 100% by weight of the total of ethylenically unsaturated monomers (b2). The present invention relates to a graft type dispersant of the invention of 5.

  Moreover, 7th invention is characterized by including 30-100 weight% of monomers represented by following General formula (1) in the total 100 weight% of ethylenically unsaturated monomer (b2). The present invention relates to the graft type dispersant of the third invention.

[In General Formula (1), R ¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 6 to 15 carbon atoms. ]

  The eighth invention is characterized in that the weight average molecular weight of the vinyl polymer (b) having one free carboxyl group in one end region is 1,000 to 30,000. The present invention relates to the graft type dispersant of the invention.

  Moreover, 9th invention is the glass transition temperature of 50-200 degreeC of the vinyl polymer (b) which has one free carboxyl group in one terminal area | region, The invention of any one of 1-8 characterized by the above-mentioned. The present invention relates to a graft type dispersant.

  The tenth invention is the graft according to any one of the first to ninth inventions, wherein the weight average molecular weight is 1,500 to 100,000, and the amine value is 2 to 40 mgKOH / g. It relates to a mold dispersant.

  The eleventh invention relates to a pigment composition containing the graft type dispersant of any one of the first to tenth inventions and a pigment.

  The twelfth invention also relates to a pigment composition according to the eleventh invention characterized by containing a pigment derivative having an acidic group represented by the following general formula (2).

General formula (2)
PZ ¹
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , Z ¹ represents a sulfonic acid group or a carboxyl group, a kind of organic dye residue selected from flavanthrone, pyranthrone, and anthrapyrimidine.

  The thirteenth invention also relates to a pigment composition according to the eleventh invention characterized by containing a pigment derivative having an acidic group represented by the following general formula (3).

General formula (3)
(PZ ² ) [N ⁺ (R ² , R ³ , R ⁴ , R ⁵ )]
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , A type of organic dye residue selected from flavanthrone, pyranthrone, and anthrapyrimidine, R ² is an alkyl group having 5 to 20 carbon atoms, R ³ , R ⁴ , and R ⁵ are each independently hydrogen Represents an atom or an alkyl group having 1 to 20 carbon atoms, Z ² represents SO ₃ ^— or COO ^— )

  The fourteenth invention also relates to a pigment composition according to the eleventh invention characterized by containing a pigment derivative having an acidic group represented by the following general formula (4).

General formula (4)
(P−Z ² ) M ⁺
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , M represents a Na or K atom, and Z ² represents SO ₃ ⁻ or COO ⁻ ), a flavanthrone type, a pyranthrone type, and an anthrapyrimidine type.

  The fifteenth invention relates to a pigment dispersion comprising the pigment composition of any of the eleventh to fourteenth inventions and a varnish.

  By using the graft type dispersant of the present invention, it was possible to provide a pigment composition having dispersibility, fluidity, and storage stability that was not obtained conventionally. Furthermore, it is suitable for offset inks, gravure inks, resist inks for color filters, ink jet inks, paints, and colored resin compositions, and has high dispersibility and stability with excellent non-aggregation and fluidity, and high storage stability. And a pigment dispersion having high temporal stability could be provided.

  In general, a pigment dispersant has a structure of a part that adsorbs to a pigment and a part that has a high affinity for a solvent that is a dispersion medium, and the performance of the dispersant is determined by the balance of these two parts. That is, in order to develop dispersibility, both the ability of the dispersant to adsorb to the pigment and the affinity to the solvent as the dispersion medium are very important. In the graft type dispersant of the present invention, a basic group existing in the main chain or in the vicinity of the main chain derived from the polymer (a) having a primary and / or secondary amino group is adsorbed to the pigment, and one in one end region. The side chain derived from the vinyl polymer (b) having a free carboxyl group has a function of having an affinity for a solvent.

  The graft type dispersant of the present invention has one free carboxyl group in one end region with respect to a total of 1 mol of primary and secondary amino groups in the polymer (a) having primary and / or secondary amino groups. It is a dispersant obtained by addition reaction of 0.5 to 0.95 mol of carboxyl groups in the vinyl polymer (b).

  First, the polymer (a) having a primary and / or secondary amino group will be described. The polymer (a) is an ethylenically unsaturated monomer having a primary amino group or an ethylenically unsaturated monomer having a secondary amino group, for example, a homopolymer of vinylamine or allylamine (so-called polyvinylamine or polyallylamine). ), Copolymers thereof with other ethylenically unsaturated monomers, ring-opening polymers of ethyleneimine, polycondensates of ethylene chloride and ethylenediamine, and ring-opening polymers of oxazolidone-2 (so-called Polyethyleneimine) is preferred. As content rate of the primary and secondary amino group in a polymer (a), 10 to 100 weight% is preferable at a monomer unit, and 20 to 100 weight% is more preferable. If the content is 10% by weight or more, it is effective for preventing aggregation of pigments and suppressing an increase in viscosity.

  Examples of the ethylenically unsaturated monomer copolymerizable with an ethylenically unsaturated monomer having a primary amino group or an ethylenically unsaturated monomer having a secondary amino group include unsaturated carboxylic acids [for example, (meta ) Acrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid], aromatic vinyl compounds [eg, styrene, α-methylstyrene, p-hydroxystyrene, chloromethylstyrene, indene, and vinyltoluene], (meta ) Acrylic acid alkyl ester [for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate], (meth) acrylic Acid alkyl aryl esters [eg benzyl (meth) acrylate], (meth ) Acrylic acid substituted alkyl esters [eg glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate)], alkyl (meth) acrylamide, [eg , (Meth) acrylamide, dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, n-butyl (meth) acrylamide, tert-butyl (meth) acrylamide, and tert-octyl (meth) acrylamide], substituted alkyl (meta ) Acrylamide [eg, dimethylaminoethyl (meth) acrylamide, and dimethylaminopropyl (meth) acrylamide], vinyl cyanide, diene compound [eg, 1,3-butadiene, And isoprene], and polymerizable oligomers [for example, one-end methacryloylated polymethyl methacrylate oligomer, one-end methacryloylated polystyrene oligomer, and one-end methacryloylated polyethylene glycol].

  The weight average molecular weight (Mw) in terms of polystyrene by GPC (gel permeation chromatography) of the polymer (a) having a primary and / or secondary amino group is preferably 300 to 75,000, More preferably, it is -20,000, and it is especially preferable that it is 500-5,000. When the weight average molecular weight is 300 to 75,000, it is effective to suppress the viscosity increase of the pigment dispersion by preventing the aggregation of the pigment.

  The content of the polymer (a) having a primary and / or secondary amino group constituting the graft type dispersant of the present invention is 0.5 to 40 in a total of 100% by weight of the weight of the graft type dispersant. % By weight is preferred, and 1.5 to 20% by weight is more preferred. If the said content rate is 0.5 to 40 weight%, sufficient adsorption power to the pigment of the said graft type polymer can be hold | maintained. Further, it is effective in maintaining a sufficient steric repulsion effect as a pigment dispersant and suppressing an increase in the viscosity of the dispersion.

  Next, the vinyl polymer (b) having one free carboxyl group in one end region (hereinafter, also simply referred to as “vinyl polymer (b)”) will be described. The vinyl polymer (b) is obtained by radical polymerization of the ethylenically unsaturated monomer (b2) in the presence of the compound (b1) having one carboxyl group and one thiol group in the molecule. Can do. A vinyl polymer (b) is a site | part with high affinity to the solvent which is a dispersion medium, and is represented by following General formula (5).

[In the general formula (5), R ⁶ is a residue obtained by removing a carboxyl group and a thiol group from the compound (b1), and R ⁷ is a double bond site and R ⁸ from the ethylenically unsaturated monomer (b2). And R ⁸ is a hydrogen atom or a methyl group. N is an integer of 2 or more, preferably an integer of 3 to 200. Here, R ⁶ is a terminal region in the vinyl polymer (b). ]

  Compound (b1) having one carboxyl group and one thiol group in the molecule (hereinafter sometimes simply referred to as “compound (b1)”) means one carboxyl group and one thiol in the molecule. And a thioacetic acid, thioglycolic acid, mercaptopropionic acid, β-mercaptopropionic acid, thiosalicylic acid, 2-mercaptonicotinic acid, 6-mercaptonicotinic acid and the like. .

  Compound (b3) having two or more carboxyl groups and one thiol group in the molecule is used in combination with (b1) instead of compound (b1) having one carboxyl group and one thiol group in the molecule May be used. Examples of the compound (b3) include thiomalic acid.

  A compound (b1), an ethylenically unsaturated monomer (b2), and, optionally, a polymerization initiator, in accordance with the molecular weight of the vinyl polymer (b) having one free carboxyl group in the desired one terminal region. The vinyl polymer (b) can be obtained by mixing and heating. Compound (b1) is preferably obtained by bulk polymerization or solution polymerization using 1 to 30 parts by weight, more preferably 3 to 12 parts by weight, based on 100 parts by weight of ethylenically unsaturated monomer (b2). More preferably, it is 4 to 12 parts by weight, particularly preferably 5 to 9 parts by weight. The reaction temperature is 40 to 150 ° C, preferably 50 to 110 ° C.

  In the polymerization, 0.001 to 5 parts by weight of a polymerization initiator can be arbitrarily used with respect to 100 parts by weight of the ethylenically unsaturated monomer (b2). As the polymerization initiator, an azo compound and an organic peroxide can be used. Examples of the azo compounds include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2 , 2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate) 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) Propane] and the like. Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl) peroxy Examples thereof include dicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide. These polymerization initiators can be used alone or in combination of two or more.

  In the case of solution polymerization, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone and the like are used as the polymerization solvent, but are not particularly limited thereto. These polymerization solvents may be used as a mixture of two or more kinds, but are preferably used for final use.

Examples of the ethylenically unsaturated monomer (b2) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl. (Meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, isobornyl (meth) Alkyl (meth) acrylates such as acrylate;
Aromatic (meth) acrylates such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate;
Heterocyclic (meth) acrylates such as tetrahydrofurfuryl (meth) acrylate and oxetane (meth) acrylate;
Alkoxypolyalkylene glycol (meth) acrylates such as methoxypolypropylene glycol (meth) acrylate and ethoxypolyethylene glycol (meth) acrylate;
N-substituted type (meth) such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, diacetone (meth) acrylamide, acryloylmorpholine Acrylamides;
Amino group-containing (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate;
And nitriles such as (meth) acrylonitrile.

  Examples of monomers that can be used in combination with the acrylic monomer include styrenes such as styrene and α-methylstyrene, vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether, and acetic acid. And fatty acid vinyls such as vinyl and vinyl propionate.

  Moreover, a carboxyl group-containing ethylenically unsaturated monomer can be used in combination. As the carboxyl group-containing ethylenically unsaturated monomer, one or more kinds can be selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like.

  In the present invention, methyl methacrylate is preferably used among the ethylenically unsaturated monomers (b2) exemplified above, and it is more preferable to use methyl methacrylate and butyl methacrylate in combination. When methyl methacrylate is used as the ethylenically unsaturated monomer (b2) and butyl methacrylate is not used, the proportion of methyl methacrylate is 30 in 100% by weight of the total ethylenically unsaturated monomer (b2). It is preferably ˜100% by weight, and more preferably 50˜100% by weight. Further, when methyl methacrylate and butyl methacrylate are used in combination as the ethylenically unsaturated monomer (b2), the total of both accounts for 30 to 100% by weight of the ethylenically unsaturated monomer (b2). It is preferable to occupy 50 to 100% by weight. When methyl methacrylate is used as the ethylenically unsaturated monomer (b2), and further when methyl methacrylate and butyl methacrylate are used in combination, the pigment dispersibility becomes better.

  In the present invention, among the ethylenically unsaturated monomers (b2) exemplified above, the use of a monomer represented by the following general formula (1) is also one preferred embodiment. The amount of the monomer represented by the general formula (1) is preferably 30 to 100% by weight and more preferably 30 to 70% by weight in the total 100% by weight of the ethylenically unsaturated monomer (b2). . When the monomer represented by the general formula (1) is used, the solvent affinity is improved and the pigment dispersibility is improved.

[In General Formula (1), R ¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 6 to 15 carbon atoms. ]

  The weight average molecular weight (Mw) in terms of polystyrene by GPC of the vinyl polymer (b) having one free carboxyl group in one end region is preferably 1,000 to 30,000, preferably 1,000 to 15,000 is more preferable, and 2,000 to 8,000 is particularly preferable. When the weight average molecular weight is 1,000 to 30,000, it is advantageous to suppress an increase in viscosity of the pigment dispersion by preventing aggregation of the pigment.

  The glass transition temperature (Tg) of the vinyl polymer (b) having one free carboxyl group in one end region is preferably 50 to 200 ° C., more preferably 50 to 120 ° C., from the viewpoint that the resistance of the coating film is improved. preferable.

  As the Tg of the vinyl polymer (b) having one free carboxyl group in one end region in the present invention, a value calculated by the following Fox formula was used. In addition, although the skeleton derived from the compound (b1) having one carboxyl group and one thiol group in the molecule is also present in the vinyl polymer (b), it is excluded from the following calculation for calculating the glass transition temperature. To do.

1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wn / Tgn
W1 to Wn indicate the weight fraction of each monomer used, and Tg1 to Tgn indicate the glass transition temperature of each homopolymer obtained from each monomer (unit: absolute temperature “K”). Show.

  The Tg of the main homopolymer used for the calculation is exemplified below.

Methyl acrylate: 105 ° C (378K)
Butyl methacrylate: 20 ° C (293K)
Isobornyl acrylate: 97 ° C (370K)
Butyl acrylate: -45 ° C (228K)
Cyclohexyl methacrylate: 66 ° C (339K)
Benzyl methacrylate: 54 ° C (327K)
2-hydroxypropyl methacrylate: 26 ° C (299K)
N, N-dimethylaminoethyl methacrylate: 18 ° C. (291 K)
Styrene: 100 ° C (373K)
Dicyclopentanyl methacrylate: 175 ° C (448K)

  Next, the reaction between the polymer (a) having a primary and / or secondary amino group and the vinyl polymer (b) having one free carboxyl group in one end region will be described.

  The graft type dispersant of the present invention is a vinyl having a total of 1 mol of primary and secondary amino groups in the polymer (a) having primary and / or secondary amino groups and one free carboxyl group in one terminal region. It is characterized by an addition reaction of 0.5 to 0.95 mol of carboxyl groups in the polymer (b). When the proportion of the carboxyl group to be reacted is less than 0.5 mol, less than 50 mol% of amino groups in the polymer (a) are bound to the carboxyl groups and acid amide bonds in the vinyl polymer (b). Formation or salt formation. In this case, since the number of the polymer (a) which is a solvent affinity site decreases, aggregation of pigments occurs, resulting in insufficient viscosity reduction effect and a defect in the appearance of the coating film, and cannot be used as a dispersant.

  On the other hand, when the proportion of carboxyl groups to be reacted exceeds 0.95 mol, more than 95 mol% of amino groups in the polymer (a) are converted into carboxyl groups and acids in the vinyl polymer (b). An amide bond or a salt is formed. In this case, the free amino group adsorbing to the pigment is insufficient, making it difficult to contribute to pigment dispersion, resulting in insufficient viscosity reduction effect and defects in the coating film appearance.

  The reaction end point of the primary and / or secondary amino group and the carboxyl group was confirmed by measuring the amine value by potentiometric titration.

  When the polymer (a) having primary and / or secondary amino groups is reacted with the vinyl polymer (b) having one free carboxyl group at one terminal region, different types of vinyl polymers (b) Alternatively, a low molecular weight carboxylic acid or the like may be reacted at the same time. A catalyst may be used for the reaction.

  The low molecular weight carboxylic acid is not particularly limited as long as the molecular weight of the formula is 1,000 or less, and examples thereof include alkyls such as acetic acid, propionic acid, myristic acid, stearic acid, and versatic acid. Examples thereof include monocarboxylic acids, alkenyl monocarboxylic acids such as acrylic acid, methacrylic acid, and oleic acid, and aromatic monocarboxylic acids such as benzoic acid.

  At this time, the reaction between the polymer (a) having a primary and / or secondary amino group and the vinyl polymer (b) having one free carboxyl group in one terminal region is carried out by the former free amino group and the latter terminal. It is a salt formation via a free carboxyl group or an acid amide bond formation reaction. Depending on the reaction conditions, an ester-amide exchange reaction also occurs simultaneously.

  Although the acid amide bond forming reaction and the salt forming reaction proceed simultaneously, the acid amide bond forming reaction is preferably performed at 90 to 210 ° C, preferably 100 to 210 ° C. If it exceeds 210 ° C, the reaction product will be colored, and if it is less than 90 ° C, the reaction time will be long. In addition, when the reaction is carried out under a nitrogen stream, a product with little coloring is obtained. On the other hand, 20-140 degreeC is preferable as reaction temperature which performs salt formation.

  The weight average molecular weight (Mw) of the graft type dispersant of the present invention is preferably 1,500 to 100,000, more preferably 2,000 to 50,000, particularly preferably 2,000 to 20,000. It is. If the weight average molecular weight is less than 1,500, the stability of the pigment composition may decrease. If the weight average molecular weight exceeds 100,000, the interaction between the resins may increase, and the pigment composition may increase in viscosity. is there. Moreover, it is preferable that the amine value of the obtained graft type dispersing agent is 2-40 mgKOH / g, More preferably, it is 3-30 mgKOH / g. If the amine value is less than 2 mgKOH / g, the functional group that adsorbs to the pigment is insufficient, and it may be difficult to contribute to pigment dispersion. If it exceeds 40 mgKOH / g, the pigments aggregate with each other, resulting in a decrease in viscosity. Insufficient effects and defects in the appearance of the coating film may occur.

  As described above, the present invention provides a primary and secondary amino group in the polymer (a) having a primary and / or secondary amino group that becomes a site to be adsorbed to the pigment, and one end that is a solvent-affinity part. It is a graft type dispersant produced by addition reaction of a carboxyl group in the vinyl polymer (b) having one free carboxyl group in the region. In the present invention, it is preferable to use polyallylamine or polyethyleneimine as the polymer (a) because of its high pigment adsorbing ability and good dispersibility.

  A pigment composition can be obtained by mixing and dispersing the graft type dispersant of the present invention and a pigment. The pigment used in the present invention is not particularly limited, for example, soluble azo pigment, insoluble azo pigment, phthalocyanine pigment, quinacridone pigment, isoindolinone pigment, isoindoline pigment, perylene pigment, perinone pigment, dioxazine pigment, anthraquinone pigment, There are dianthraquinonyl pigment, anthrapyrimidine pigment, ansanthrone pigment, indanthrone pigment, flavanthrone pigment, pyranthrone pigment, diketopyrrolopyrrole pigment, etc. Pigment Black 7, Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 60, Pigment Green 7, 36, Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 144, 146, 149, 166, 68, 177, 178, 179, 185, 206, 207, 209, 220, 221, 238, 242, 254, 255, Pigment Violet 19, 23, 29, 30, 37, 40, 50, Pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151, 154, 155, 166, 168, 180, 185, 213, Pigment Orange 13, 36, 37, 38, 43, 51, 55, 59, 61, 64, 71, 74, and the like. As for carbon black, any carbon black such as neutral, acidic and basic can be used.

  Next, the pigment derivative having an acidic group used in the present invention will be described. The pigment derivative having an acidic group is classified into a pigment derivative having no charge represented by the following general formula (2) or a pigment derivative having a charge represented by the following general formula (3) or (4).

General formula (2)
PZ ¹
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone, (One type of organic dye residue selected from flavanthrone, pyranthrone, and anthrapyrimidine, Z ¹ represents a sulfonic acid group or a carboxyl group.)

General formula (3)
(PZ ² ) [N ⁺ (R ² , R ³ , R ⁴ , R ⁵ )]
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone, One organic pigment residue selected from flavanthrone, pyranthrone, and anthrapyrimidine, R ² is an alkyl group having 5 to 20 carbon atoms, R ³ , R ⁴ , and R ⁵ are each independently a hydrogen atom Or an alkyl group having 1 to 20 carbon atoms, Z ² represents SO ₃ ^— or COO ^— .

General formula (4)
(P−Z ² ) M ⁺
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone, flavanthrone-based, pyranthrone, and organic colorant residue of one selected from anthrapyrimidine, M is, .Z ² representing the Na or K atom, SO ₃ ^- or COO ^- represents a).

  P in the pigment derivatives represented by the general formulas (2) to (4) represents an organic dye residue, but it can be used in offset ink, gravure ink, color filter resist ink, ink jet ink, paint, and colored resin composition. The chemical structure of the pigment used does not necessarily match the chemical structure of the organic dye residue, but it can be used to disperse yellow pigments in consideration of the hue of the ink that is finally produced. Pigments that disperse like yellow pigment derivatives, red pigment derivatives when used to disperse red pigments, and blue pigment derivatives when used to disperse blue pigments A pigment dispersion that is excellent in hue can be produced by using the one having a hue close to or colorless.

  In the present invention, a dispersant other than the graft type dispersant of the present invention may be added in order to improve the dispersibility of the pigment and the storage stability of the pigment composition and the pigment dispersion. Such dispersants include hydroxyl group-containing carboxylic acid esters, salts of long chain polyaminoamides and high molecular weight acid esters, salts of high molecular weight polycarboxylic acids, salts of long chain polyaminoamides and polar acid esters, Saturated acid ester, polymer copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate salt, polyoxyethylene alkyl phosphate ester Polyoxyethylene nonylphenyl ether, stearylamine acetate and the like can be used.

  Specific examples of the dispersant include “Anti-Terra-U (polyaminoamide phosphate)”, “Anti-Terra-203 / 204 (high molecular weight polycarboxylate)” manufactured by BYK Chemie, “Disperbyk-101 ( Salt of long-chain polyaminoamide and polar acid ester), 107 (hydroxyl group-containing carboxylic acid ester), 110, 111 (copolymerization product containing acid group), 130 (polyamide), 161, 162, 163, 164, 165, 166, 170, 180, 182 (high molecular weight copolymer) "," Bykumen (high molecular weight unsaturated acid ester) "," BYK-P104, P105 (high molecular weight unsaturated acid polycarboxylic acid) "," P104S, 240S " (Mixture of high molecular weight unsaturated acid polycarboxylic acid and polysiloxane) "," Lactim n (a mixture of partial amides product and polysiloxanes with long chain amine and an unsaturated acid polycarboxylic acid) "can be mentioned.

  In addition, “Efka CHEMICALS” “Efka 44, 46, 47, 48, 49, 54, 63, 64, 65, 66, 71, 701, 764, 766”, “Efka Polymer 100 (modified polyacrylate), 150 (aliphatic) System modified polymer), 400, 401, 402, 403, 450, 451, 452, 453 (modified polyacrylate), 745 (copper phthalocyanine system) "," Kyoeisha Chemical Co., Ltd. "" Floren TG-710 (urethane oligomer) "," “Flonon SH-290, SP-1000”, “Polyflow No. 50E, No. 300 (acrylic copolymer)”, “Disparon KS-860, 873SN, 874 (polymer dispersing agent), # 2150, manufactured by Enomoto Kasei Co., Ltd. (Aliphatic polyvalent carboxylic acid), # 7004 (polyether ester type) " It is.

  Furthermore, “Demol RN, N (Naphthalenesulfonic acid formalin condensate sodium salt), MS, C, SN-B (aromatic sulfonic acid formalin condensate sodium salt), EP”, “Homogenol L-18 (Polyethylene)” manufactured by Kao Corporation Carboxylic acid type polymer) ”,“ Emulgen 920, 930, 931, 935, 950, 985 (polyoxyethylene nonyl phenyl ether) ”,“ Acetamine 24 (coconut amine acetate), 86 (stearyl amine acetate) ”, Lubrizol “Solspers 5000 (phthalocyanine ammonium salt type), 13940 (polyesteramine type), 17000 (fatty acid amine type), 24000” manufactured by Nikko Chemical Co., Ltd. “Nikkor T106 (polyoxyethylene sorbitan monooleate), MYS-IEX (Polio) Xylene (monoethylene stearate), Hexagline 4-0 (hexaglyceryl tetraoleate) "," Ajisper PB821, PB822 (basic dispersant) "manufactured by Ajinomoto Fine Techno Co., and the like. The dispersant is preferably contained in the ink in an amount of 0.1 to 10% by weight.

  As the organic solvent used in the present invention, organic solvents used in offset ink, gravure ink, color filter resist ink, ink jet ink, paint, and colored resin composition can be widely used. If it supplements, if the graft type dispersing agent of the present invention is an organic solvent which dissolves or suspends uniformly, there will be no restriction in particular.

Specific examples of organic solvents include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol;
Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl-n-amyl ketone, methyl isoamyl ketone, diethyl ketone, ethyl-n-propyl ketone, ethyl isopropyl ketone, ethyl Ketones such as n-butyl ketone, ethyl isobutyl ketone, di-n-propyl ketone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, isophorone;
Esters such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, hexyl acetate, octyl acetate, methyl lactate, propyl lactate, butyl lactate;
Lactones such as γ-butyrolactone and ε-caprolactone;
Ethylene glycol, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, Diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl Ether, dipropylene glycol monoethyl ether, dipropylene glycol dipropyl ether, tripropylene glycol monomethyl ether, glycol and glycol ethers such as tetraethylene glycol dimethyl ether;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol Glycol acetates such as monobutyl ether acetate and dipropylene glycol monomethyl ether acetate;
saturated hydrocarbons such as n-hexane, isohexane, n-nonane, isononane, dodecane, isododecane;
Unsaturated hydrocarbons such as 1-hexene, 1-heptene, 1-octene;
Cyclic saturated hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, cyclodecane, decalin;
Cyclic unsaturated hydrocarbons such as cyclohexene, cycloheptene, cyclooctene, 1,1,3,5,7-cyclooctatetraene, cyclododecene;
(N-alkyl) pyrrolidones such as N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone;
N-alkyl oxazolidinones such as N-methyl-2-oxazolidinone;
Aromatic hydrocarbons such as benzene, toluene, xylene and the like.

  These organic solvents may be used singly or as a mixture of two or more, but are preferably used for final use.

  The pigment dispersion in the present invention is obtained by dissolving or suspending a graft type dispersant in an organic solvent, and then, in this liquid, a pigment and, if necessary, a pigment represented by the general formulas (2) to (4) After introducing the derivative and stirring and mixing until uniform with a high speed mixer, etc., it is dispersed using various dispersers such as a bead mill such as a horizontal sand mill, a vertical sand mill, an annular sand mill, a roll mill, and a medialess disperser. Can be manufactured. In addition, the pigment derivative may be used as a treatment agent for surface-treating the pigment in advance by adding it during the production of the pigment.

  The pigment composition of the present invention can be used as various printing inks and ink-jet inks, and can be used as a pigment dispersion by adding a varnish in order to impart fixability during color development. Resins that can be used as varnish include petroleum resin, 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 resin, vinylidene chloride resin, vinyl acetate resin, ethylene vinyl acetate resin, acrylic resin, methacrylic resin, polyurethane resin, silicone resin, Fluorine resin, drying oil, synthetic drying oil, styrene-maleic acid resin, styrene-acrylic resin, polyamide resin, butyral resin and the like.

  The pigment dispersion of the present invention is a plasticizer, a surface conditioner, an ultraviolet light inhibitor, a light stabilizer, an antioxidant, an antistatic agent, an antiblocking agent, an antifoaming agent, a viscosity modifier, a wax, depending on the use to be used Various additives such as a surfactant and a leveling agent can be used.

  The pigment dispersion of the present invention can also be used as a radiation curable ink containing a polymerizable monomer or oligomer and cured by ultraviolet rays or electron beams.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not specifically limited to an Example. In the examples, “parts” represents “parts by weight” and “%” represents “% by weight”. The number average molecular weight (Mn) and weight average molecular weight (Mw) are TPCgel column (manufactured by Tosoh Corporation), GPC equipped with RI detector (manufactured by Tosoh Corporation, HLC-8120GPC), and THF as a developing solvent. It is a molecular weight in terms of polystyrene when used.

(Production Example 1) [Synthesis of vinyl polymer (b)]
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 1440 parts of methyl methacrylate, 60 parts of thioglycolic acid, and 1500 parts of propylene glycol monomethyl ether acetate (PGMAc), and replaced with nitrogen gas. The inside of the reaction vessel was heated to 80 ° C. and reacted for 12 hours. After confirming that 95% had reacted by solid content measurement, it was cooled to room temperature, and the solid content of the vinyl polymer having a weight average molecular weight of 3000 and having one free carboxyl group in one end region (intermediate 1) was 50%. A solution was obtained.

(Production Examples 2 to 13) [Synthesis of vinyl polymer (b)]
The synthesis was performed in the same manner as in the synthesis of Intermediate 1 except that the raw materials and preparation amounts shown in Table 1 were used, and the solid content of the vinyl polymer (Intermediates 2 to 13) having one free carboxyl group in one end region A 50% solution was obtained.

MMA: methyl methacrylate BMA: n-butyl methacrylate IBXA: isobornyl acrylate BA: butyl acrylate CHMA: cyclohexyl methacrylate BzMA: benzyl methacrylate HPM: 2-hydroxypropyl methacrylate DM: N, N-dimethylaminoethyl methacrylate St: styrene N- PhM: N-phenylmaleimide FA513M: Dicyclopentanyl methacrylate [manufactured by Hitachi Chemical Co., Ltd.]
TGA: thioglycolic acid 3-MPA: 3-mercaptopropionic acid PGMAc: propylene glycol monomethyl ether acetate Tg: glass transition temperature

(Example 1)
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 20 parts of polyethyleneimine (weight average molecular weight 1800), 802 parts of a 50% solid solution of intermediate 1 and 20 parts of PGMAc, and replaced with nitrogen gas. did. The reaction vessel was heated to 140 ° C. and reacted for 8 hours. After confirming that the amine value was 7.9 mg KOH / g (theoretical amine value) by potentiometric titration, the solution was cooled to room temperature to obtain a solution of graft type dispersant 1 having a weight average molecular weight of 3600.

(Examples 2 to 16)
The synthesis was carried out in the same manner as in Example 1 except that the raw materials and the charge amounts shown in Table 2 were used to obtain solutions of graft type dispersants (Examples 2 to 16).

PEI: Polyethyleneimine PAA: Polyallylamine

(Comparative Example 1)
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 20 parts of polyethyleneimine (weight average molecular weight 3000), 279 parts of a 50% solids solution of intermediate 2 and 20 parts of PGMAc, and replaced with nitrogen gas. did. The reaction vessel was heated to 140 ° C. and reacted for 8 hours. After confirming that the amine value was 46.0 mg KOH / g (theoretical amine value), the solution was cooled to room temperature to obtain a solution of graft type dispersant 17 having a weight average molecular weight of 6000.

(Comparative Example 2)
Synthesis was performed in the same manner as in Example 1 except that the raw materials and preparation amounts shown in Table 3 were used, and a solution of graft type dispersant 18 was obtained.

PEI: Polyethyleneimine PAA: Polyallylamine

(Comparative Example 3)
In a reaction flask equipped with a thermometer, a stirrer, a nitrogen inlet and a reflux tube, 10.0 parts of 12-hydroxystearic acid (manufactured by Junsei Chemical) and 190 parts of ε-caprolactone (manufactured by Junsei Chemical) are charged and a nitrogen stream The temperature was raised to 160 ° C. over 4 hours, heated at 160 ° C. for 2 hours, and then heated until the remaining amount of ε-caprolactone was 1% or less. Subsequently, it was cooled to room temperature to obtain polyester (number average molecular weight 2604, acid value 21.5 mgKOH / g). Also, a mixture of 25.0 parts of xylene and 70 parts of a polyallylamine 10% aqueous solution [“PAA-1LV” manufactured by Nitto Boseki Co., Ltd., number average molecular weight of about 3,000] is stirred at 160 ° C., and a separator is used. Then, while distilling water and returning xylene to the reaction solution, 13.9 parts of the previously obtained polyester was heated to 160 ° C., and reacted at 160 ° C. for 2 hours. A solution of dispersant 19 (number-average molecular weight 10,500, amine value 38.5 mg KOH / g) was obtained.

(Comparative Example 4)
“Johncry 682” (low molecular weight alkali-soluble styrene acrylic copolymer manufactured by SC Johnson; Mn980, Mw1620, acid value 235 mgKOH / g, softening point 110 ° C., glass transition point 50 ° C.) 238.8 parts, "Emulgen 105" [Kao Co., Ltd. polyoxyethylene lauryl ether; HLB = 9.7] 181.0 parts, n-butyl octatitanate 0.2 parts, xylene 72.5g in a nitrogen stream 170-174 The mixture was heated to reflux at 0 ° C. for 8 hours, and 9.0 parts of water was distilled off in the Dean-Stark trap.
The reaction mixture is cooled to 70 ° C., and 35.5 parts of xylene and 21.6 parts of “Epomin SP-006” (Nippon Shokubai Chemical Co., Ltd. polyethyleneimine; Mw 600) are added and heated at 136 to 138 ° C. for 1 hour. Refluxed and distilled off 1.8 parts of water in the Dean-Stark trap.
The reaction product was cooled to room temperature to obtain a single yellow-brown transparent and viscous solution of dispersant 20. This dispersant had a non-volatile content of 49%, an acid value of 38.6 mgKOH / g, an amine value of 25.0 mgKOH / g, a viscosity TU by the Gardner method, and a color number of 8.

(Example 17) <Production of pigment composition>
8.0 parts copper-phthalocyanine blue as a blue pigment, 2.0 parts monosulfonated phthalocyanine blue as a blue derivative, 2.0 parts in terms of solid content of the graft type dispersant 1 synthesized in Example 1, and 48 parts of PGMAc was blended, 100 parts of 2 mmφ zirconia beads were added, and the mixture was dispersed with Scandex for 3 hours to prepare a pigment composition.

(Examples 18 to 34 and Comparative Examples 5 to 9) <Production of Pigment Composition>
A pigment composition was prepared in the same manner as in Example 17 except that the blending ratio shown in Table 4 was changed.

DMM: Dipropylene glycol dimethyl ether IPA: Isopropyl alcohol Blue pigment: Copper-phthalocyanine blue Blue derivative: Monosulfonated phthalocyanine blue Red pigment: Anthraquinonyl red Red derivative: Monosulfonated quinacridone red Green pigment: Salt brominated phthalocyanine green Green derivative : Monosulfonated brominated phthalocyanine green Yellow pigment: Quinoxaline dione azo pigment Yellow derivative: Monosulfonated quinoxalin dione azo pigment

<Evaluation of pigment composition>
In order to evaluate the performance of the pigment composition of the present invention, the viscosity of the obtained composition was measured with a B-type viscometer (25 ° C., rotation speed 100 rpm), and haze was measured with a haze meter (light transmittance 20%). The performance of the pigment composition was evaluated by the initial viscosity and haze (the lower the viscosity, the better the haze, the lower the haze, the better). The initial viscosity and haze were measured after standing at room temperature for 1 day after dispersion. The stability over time was determined by measuring the viscosity of the prepared pigment composition after standing at 40 ° C. for one week, and comparing with the initial viscosity, ○ if less than ± 10%, Δ if ± 10-20%, ± 20 When it exceeded%, it was set as x. The results are shown in Table 5.

  As is clear from the above evaluation results, the pigment compositions of Examples 17 to 34 using the graft type dispersant of the present invention have a low initial viscosity and show good stability with little increase in viscosity over time. ing. Furthermore, the haze is also low. On the other hand, the pigment compositions of Comparative Examples 5, 6, and 9 are not stable over time and have a problem with dispersibility, and the pigment compositions of Comparative Examples 7 and 8 have a solvent selectivity and a problem with dispersibility. I found out that

Claims (15)

For a total of 1 mole of primary and secondary amino groups in the polymer (a) having primary and / or secondary amino groups,
A graft type dispersant obtained by subjecting 0.5 to 0.95 mol of a carboxyl group in a vinyl polymer (b) having one free carboxyl group in one terminal region.   The graft type dispersant according to claim 1, wherein the polymer (a) having a primary and / or secondary amino group is polyethyleneimine or polyallylamine.   The vinyl polymer (b) having one free carboxyl group in one end region is converted into an ethylenically unsaturated monomer in the presence of the compound (b1) having one carboxyl group and one thiol group in the molecule. The graft dispersant according to claim 1 or 2, wherein (b2) is radically polymerized.   The graft type dispersant according to claim 3, wherein the ethylenically unsaturated monomer (b2) contains methyl methacrylate.   The graft type dispersant according to claim 4, wherein the ethylenically unsaturated monomer (b2) further contains butyl methacrylate.   The graft type dispersant according to claim 4 or 5, wherein the total of methyl methacrylate and butyl methacrylate is 30 to 100% by weight in 100% by weight of the total of ethylenically unsaturated monomers (b2). The graft type dispersion according to claim 3, comprising 30 to 100% by weight of a monomer represented by the following general formula (1) in a total of 100% by weight of the ethylenically unsaturated monomer (b2). Agent.

[In General Formula (1), R ¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic alkyl group having 6 to 15 carbon atoms. ]   The graft type dispersant according to any one of claims 1 to 7, wherein the vinyl polymer (b) having one free carboxyl group in one end region has a weight average molecular weight of 1,000 to 30,000. .   The graft type dispersant according to any one of claims 1 to 8, wherein the glass transition temperature of the vinyl polymer (b) having one free carboxyl group in one end region is 50 to 200 ° C.   The graft type dispersant according to any one of claims 1 to 9, wherein the weight average molecular weight is 1,500 to 100,000, and the amine value is 2 to 40 mgKOH / g.   A pigment composition comprising the graft type dispersant according to claim 1 and a pigment. The pigment composition according to claim 11, comprising a pigment derivative having an acidic group represented by the following general formula (2).
General formula (2)
PZ ¹
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , Z ¹ represents a sulfonic acid group or a carboxyl group, a kind of organic dye residue selected from flavanthrone, pyranthrone, and anthrapyrimidine. The pigment composition according to claim 11, comprising a pigment derivative having an acidic group represented by the following general formula (3).
General formula (3)
(PZ ² ) [N ⁺ (R ² , R ³ , R ⁴ , R ⁵ )]
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , A type of organic dye residue selected from flavanthrone, pyranthrone, and anthrapyrimidine, R ² is an alkyl group having 5 to 20 carbon atoms, R ³ , R ⁴ , and R ⁵ are each independently hydrogen Represents an atom or an alkyl group having 1 to 20 carbon atoms, Z ² represents SO ₃ ^— or COO ^— ) The pigment composition according to claim 11, comprising a pigment derivative having an acidic group represented by the following general formula (4).
General formula (4)
(P−Z ² ) M ⁺
(In the formula, P represents azo, benzimidazolone, phthalocyanine, quinacridone, anthraquinone, dioxazine, diketopyrrolopyrrole, quinophthalone, isoindolinone, isoindoline, perylene, perinone. , M represents a Na or K atom, and Z ² represents SO ₃ ⁻ or COO ⁻ ), a flavanthrone type, a pyranthrone type, and an anthrapyrimidine type.   A pigment dispersion comprising the pigment composition according to claim 11 and varnish.