JP2000273346A - Pigment dispersant and pigment composition prepared by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pigment dispersant which gives a pigment dispersion excellent in non-aggregating properties, non-crystallinity, and fluidity by selecting an amine compound having a diketopyrrolopyrrole residue. SOLUTION: This pigment dispersant is represented by formula I [wherein DPP is a diketopyrrolopyrrole residue represented by formula II; E is a group represented by formula III or IV; R1 to R15 are each H, a halogen, (halogeno) alkyl, alkoxy(carbonyl), CN, sulfonyl, COOH, dialkylamino, alkylmercapto, carbamoyl or sulfamoyl provided at least one of them is a linkage for E and at least one of R6 to R15 is a linkage for a group represented by formula V; m is 1-2; p is 1-4; X is a direct bond, SO2NH, CONH, CH2NHCOCH2NH or (CH2)qNH; q is 1-10; n is 1-20 provided when X is a direct bond, then n is 1-10; R16 and R17 are each an alkyl or a heterocyclic group having an N, O or S atom; Z is X (other than a direct bond), SO2, CO, CH2NHCOCH2 or (CH2)q; R22 is an alkyl or an aryl; and R18 to R21 are each H or R22].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a pigment dispersant and a pigment composition which provide a pigment dispersion excellent in usability, especially non-aggregation, non-crystallinity and fluidity.

[0002]

2. Description of the Related Art When fine particles of pigment are dispersed in non-aqueous vehicles such as offset inks, gravure inks, and paints, it is difficult to obtain a stable dispersion, and this is a problem in terms of manufacturing operations and the value of the resulting product. It is known to cause various problems that have significant effects. For example, a dispersion containing a pigment composed of fine particles often has a high viscosity, which not only makes it difficult to remove and transport the product from the disperser, but also worse, causes gelation during storage and causes use. It can be difficult. When a mixture of different kinds of pigments is used, color unevenness or a marked decrease in coloring power may be caused in the developed product due to a phenomenon such as color separation due to aggregation or sedimentation.

In order to solve the above-mentioned various problems, US Pat. No. 3,370,971 and US Pat.
No. 5511, Japanese Patent Publication No. 41-2466 and U.S. Pat.
A method of stably dispersing a pigment has been proposed in, for example, SP 2855403. Regarding the improvement of the dispersion of diketopyrrolopyrrole pigments, JP-A-3-26767 and JP-A-3-45662 propose a method of adding a diketopyrrolopyrrole derivative as a dispersant. In addition, Japanese Patent Application Laid-Open Nos.
JP-A-9961 proposes a method of adding a quinacridone derivative as a dispersant, and JP-A-1-217076 proposes a method of adding a perylene derivative as a dispersant.

[0004]

However, it is very difficult to disperse the diketopyrrolopyrrole-based pigment, and even if the above-mentioned pigment derivative is used as a dispersant, a satisfactory effect cannot always be obtained. An excellent pigment dispersant has been desired. In addition, the diketopyrrolopyrrole pigment is
CI Pigment Orange 71, CI Pigment Orange 73,
CI Pigment Red 254, CI Pigment Red 255,
CI Pigment Red 264, CI Pigment Red 270,
CI Pigment Red 272 and the like.

Accordingly, an object of the present invention is to provide a pigment dispersant and a pigment composition for obtaining a stable dispersion excellent in non-aggregation and fluidity when producing an offset ink, a gravure ink, and a paint. And

[0006]

Means for Solving the Problems The present invention provides the following formula (1)
And a pigment composition containing the pigment dispersant and a pigment. Equation (1)

Embedded image (However, DPP represents a diketopyrrolopyrrole residue represented by the following formula (2). Formula (2)

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E represents the following equation (3) or the following equation (4). Equation (3)

Embedded image Equation (4)

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R _{1 to} R ₁₅ each independently represent a hydrogen atom,
Halogen atom, or alkyl, alkoxy, cyano,
R represents a sulfonyl, carboxyl, dialkylamino, halogenoalkyl, alkoxycarbonyl, alkylmercapto, carbamoyl, or sulfamoyl group;
₁ at least one of to R ₁₅ is a bond of E, R ₆ ~
_At least one of R ₁₅ is

Embedded image Is a bond.

M: represents an integer of 1 to 2. p: represents an integer of 1 to 4. X: direct bond, -SO_Two NH-, -CONH-, -CH
_Two NHCOCH_Two NH- or-(CH_Two ) QNH-
(Where q represents an integer of 1 to 10). n: represents an integer of 1 to 20. However, if X is a direct bond
In the case, it represents an integer of 1 to 10. R₁₆, R₁₇: Each independently may be substituted
A sum or unsaturated alkyl group, or R₁₆, R₁₇In
May be substituted containing an oxygen, oxygen or sulfur atom
Represents a heterocyclic ring. Z: -SO_Two -, -CO-, -CH_Two NHCOCH_Two 
-,-(CH_Two ) Q-, -SO_Two NH-, -CONH
-, -CH_Two NHCOCH_Two NH- or-(CH
_Two ) Represents qNH- (where q represents an integer of 1 to 10)
You. ). R₁₈, R₁₉, R₂₀, R_{twenty one}: Each independently a hydrogen atom,
Optionally substituted saturated or unsaturated alkyl
Represents a group or an aryl group. R_{twenty two}: Saturated or unsaturated alkyl which may be substituted
Represents a kill group or an aryl group.

Specific structures of the pigment dispersant of the present invention include those represented by the following formulas (5) to (9).
The number and position of the substituents vary depending on the reaction conditions. Equation (5)

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Equation (6)

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Equation (7)

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Equation (8)

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Equation (9)

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There are several synthetic routes for producing the pigment dispersant of the present invention. A typical production method will be outlined below using the pigment dispersant represented by the above formula (9) as an example. Show.
First, a compound represented by the formula (10) is produced by a conventional method. Equation (10)

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Next, the compound represented by the formula (10) is chlorosulfonated by a conventional method to produce a compound represented by the formula (11).
The pigment dispersant represented by the formula (9) is produced by reacting methylpiperazine. Equation (11)

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Among E, the amine component used for forming the substituent represented by the formula (3) includes, for example,
Dimethylamine, diethylamine, N-ethylisopropylamine, N-methylbutylamine, N-methylisobutylamine, N-butylethylamine, N-tert-butylethylamine, diisopropylamine, dipropylamine, N-sec-butylpropylamine, Butylamine, di-sec-butylamine, diisobutylamine,
N-isobutyl-sec-butylamine, diamylamine, diisoamylamine, dihexylamine, di (2
-Ethylhexyl) amine, dioctylamine, N-methyloctadecylamine, didecylamine, diallylamine, N-ethyl-1,2-dimethylpropylamine,
N-methylhexylamine, 2-hydroxymethylaminomethanol, dioleylamine, distearylamine, N, N-dimethylaminomethylamine, N, N-dimethylaminoethylamine, N, N-dimethylaminopropylamine, N, N- Dimethylaminoamylamine,
N, N-dimethylaminobutylamine, N, N-diethylaminoethylamine, N, N-diethylaminopropylamine, N, N-diethylaminohexylamine,
N, N-diethylaminobutylamine, N, N-diethylaminopentylamine, N, N-dipropylaminobutylamine, N, N-dibutylaminopropylamine,
N, N-dibutylaminoethylamine, N, N-dibutylaminobutylamine, N, N-diisobutylaminopentylamine, N, N-methyl-laurylaminopropylamine, N, N-ethyl-hexylaminoethylamine, N, N- Distearylaminoethylamine, N, N
-Dioleylaminoethylamine, N, N-distearylaminobutylamine and the like.

In E, examples of the amine component used for forming the substituent represented by the formula (4) include piperidine, 2-pipecoline, 3-pipecoline,
4-Pipecoline, 2,4-Lupetidine, 2,6-Lupetidine, 3,5-Lupetidine, 3-Piperidinemethanol, Pipecolic acid, Isonipecotic acid, Methyl isonicopetinate, Ethyl isonicopetinate, 2-Piperidineethanol, Pyrrolidine, 3- Hydroxypyrrolidine, N
-Aminoethylpiperidine, N-aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidine, N-aminopropyl-2-pipecholine, N-aminopropyl-4-pipecholine, N-aminopropylmorpholine , N-methylpiperazine, N-butylpiperazine, N-tylhomopiperazine, 1-cyclopentylpiperazine, 1-amino-4-methylpiperazine and the like.

The pigment dispersant of the present invention exerts an excellent dispersing effect on almost all commercially available pigments. In particular, it has an effect on dispersing diketopyrrolopyrrole-based pigments which have been conventionally difficult to disperse. Demonstrate. Pigment dispersant of the present invention, for example, diketopyrrolopyrrole pigments, soluble and insoluble azo pigments, azo pigments such as condensation azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, isoindoline pigments, Quinophthalone pigments, perylene / perinone pigments, dioxazine pigments,
Organics such as anthraquinone pigments, dianthraquinonyl pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, pyranthrone pigments, vat dye pigments, and basic dye pigments It can be used to disperse pigments and inorganic pigments such as carbon black, titanium oxide, graphite, cadmium yellow, cadmium red, red iron oxide, iron black, zinc white, navy blue and ultramarine.

The method of using the pigment dispersant of the present invention includes:
For example, there are the following methods, and a desired effect can be obtained by any of these methods. 1. A pigment composition obtained by previously mixing a pigment and a pigment dispersant is added to a non-aqueous vehicle or the like and dispersed. 2. A pigment and a pigment dispersant are separately added and dispersed in a non-aqueous vehicle or the like. 3. A pigment and a pigment dispersant are separately dispersed in a non-aqueous vehicle or the like, and the resulting dispersion is mixed. In this case, the pigment dispersant may be dispersed only with the solvent. 4. After dispersing the pigment in a non-aqueous vehicle or the like, a pigment dispersant is added to the resulting dispersion.

The preferred amount of the pigment dispersant of the present invention in the pigment composition shown in the above item 1 is 0.1 to 40 parts by weight, more preferably 5 to 2 parts by weight, per 100 parts by weight of the pigment.
0 parts by weight. When the blending amount of the pigment dispersant of the present invention is 0.1
If the amount is less than parts by weight, a sufficient pigment dispersing effect cannot be obtained,
Further, even if it is added in an amount of more than 40 parts by weight, the effect of the used amount cannot be obtained. Even if the pigment composition is prepared by simply mixing the pigment powder and the powder of the pigment dispersant of the present invention, the desired effect can be sufficiently obtained. However, kneaders, rolls, attritors, mechanically mixed by various pulverizers such as super mills, or a solution containing the pigment dispersant of the present invention is added to a suspension system of water or an organic solvent of the pigment, and the pigment surface is added. A better mixing method such as adsorbing the pigment dispersant or co-dissolving the organic pigment and the pigment dispersant in a solvent having a strong dissolving power such as sulfuric acid and coprecipitating with a poor solvent such as water is preferred. The result can be obtained.

In the use of the pigment dispersant of the present invention as described in the above items 2 to 4, the dispersing machine such as a dissolver or a high-pressure dispersing machine is used for dispersing the pigment or the pigment dispersant in a non-aqueous vehicle or a solvent, or mixing them. Good dispersion of the pigment can be achieved by using a speed mixer, a homomixer, a kneader, a roll mill, a sand mill, an attritor, or the like.

Non-aqueous vehicles in which the pigment dispersant of the present invention is preferably used include gravure inks such as lime rosin varnish, polyamide resin varnish or vinyl chloride resin varnish, nitrocellulose lacquer, and air-dried or baked paint of amino alkyd resin. , Urethane-based resin paints, acrylic resin paints and the like. Incidentally, the use of the pigment dispersant of the present invention is not limited to only non-aqueous vehicles,
Coloring of other printing inks, paints, and plastics, as well as water-based inks, water-based paints, emulsion-type inks, and emulsion-type paints, is excellent in dispersing effect and can provide a colored substance having coloring power.

[0024]

The present invention will be described in more detail with reference to the following examples. In the following, “parts” means “parts by weight”.

(Example 1) A compound represented by the formula (10) was chlorosulfonated by a conventional method to obtain a compound 82.
Parts were dispersed in 4000 parts of water. Next, 130 parts of N, N-dimethylaminopropylamine was added, the temperature was raised to 80 ° C., and the mixture was stirred at the same temperature for 2 hours. The precipitate was filtered, washed with water and dried at 80 ° C. to obtain 92 parts of a pigment dispersant (1).
Examples 2 to 4 Pigment dispersants (2) to (4) were obtained in the same manner as in Example 1.

Example 5 A compound represented by the formula (10) was chloroacetamidomethylated by a conventional method, and 50 parts of the obtained compound was dispersed in 1000 parts of water. Next, 138 parts of N-aminopropyl-2-pipecoline were added, and the mixture was added at 90 ° C.
And stirred at the same temperature for 4 hours. The precipitate is filtered, washed with water and dried at 80 ° C. to give a pigment dispersant (5) 73
Got a part. Examples 6 and 7 Pigment dispersants (6) and (7) were obtained in the same manner as in Example 5.

(Example 8) The compound represented by the formula (10) was chloromethylated by a conventional method, and 50 parts of the obtained compound was dispersed in a mixed solvent consisting of 700 parts of water and 100 parts of methanol. Next, 110 parts of dibutylamine was added to add 70 parts.
C., and stirred at the same temperature for 2 hours. The precipitate is filtered, washed with water and dried at 80 ° C. to give a pigment dispersant (8) 64
Got a part. Examples 9 and 10 Pigment dispersants (9) and (10) were obtained in the same manner as in Example 8.

The structure of the pigment dispersant obtained in the examples is shown below.

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[0029]

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[0030]

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In order to evaluate the effect of the pigment dispersant of the present invention, two paints having the following formulations were prepared using the pigments shown in Tables 1, 2 and 3. Paint, in the following formulation components other than the mixed varnish to be added after dispersion into a container,
After adding a steel ball and dispersing with a paint shaker, a mixed varnish was added to prepare the mixture.

Formulation (1) Pigment 9.5 parts Pigment dispersant 0.5 part Alkyd resin varnish (nonvolatile content 60%) 26.4 parts Melamine resin varnish (nonvolatile content 50%) 13.6 parts Thinner (xylene) / N-butanol = 8/2) 20.0 parts Mixed varnish added after dispersion 48.3 parts (alkyd resin varnish / melamine resin varnish = 7/3 (solid content))

Formulation (2) Pigment 9.5 parts Pigment dispersant 0.5 part Oil-free polyester resin varnish (nonvolatile content 60%) 26.4 parts Melamine resin varnish (nonvolatile content 50%) 13.6 parts Swazole 20.0 parts Mixed varnish added after dispersion 48.3 parts (oil-free polyester resin varnish / melamine resin varnish = 7/3 (solid content))

The obtained paint was a paint without a pigment dispersant added (in the above formulation, no pigment dispersant was added and 10
Of the coating composition) and the following evaluation method.
Further, the pigment dispersant (11) disclosed in JP-A-3-26767 was obtained by a conventional method, and was compared according to the same evaluation method. Tables 1 and 2 show the evaluation results using the diketopyrrolopyrrole pigments. Table 3 shows the evaluation results using other pigments.

Pigment dispersant (11)

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Evaluation method (1) The viscosity of the obtained paint was measured with a B-type viscometer (measuring temperature 25 ° C., rotation speed 6 (rpm) and 60 (rpm)), and the diketopyrrolopyrrole pigment was measured. The viscosity was indicated. Also,
For the other pigments, a relative comparison was made with the viscosity of the coating material to which no pigment dispersant was added, and evaluated according to the following criteria. In addition, the thing with a low viscosity is favorable for evaluation. ：: good (less than half when no pigment dispersant is added) Δ: somewhat good (half or more when no pigment dispersant is added, less than no addition) ×: bad (equal to or more than when no pigment dispersant is added) )

Evaluation method (2) The obtained paint was applied to a Ford cup 4 having a final paint viscosity of 23.
Seconds were prepared with a thinner, sprayed on a tin plate with an air spray gun and baked, and the glossiness of the coated surface was evaluated by measuring 20 ° gloss with a gloss meter. For the diketopyrrolopyrrole-based pigment, the measurement result at 20 ° gloss was shown as it is, and for the other pigments, the measurement result at 20 ° gloss was shown based on the following criteria. ：: Excellent (20 ° gloss 90 or more) △: Good (20 ° gloss 75 or more and less than 90) ×: Poor (20 ° gloss less than 75)

Table 1 Results of Evaluation Method (1) Using Diketopyrrolopyrrole Pigment ─────── Pigment Pigment dispersant Formulation (1) Formulation (2) 6 (rpm) 60 (rpm) 6 (rpm) 60 (rpm) ─────────────── ───────────────────── CIPig Red254-2310 1160 3410 2050 1 550 460 630 510 11 1300 820 1650 1020 ─────────── ───────────────────────── CIPig Red255 − 1910 1050 2200 1120 2 630 490 750 580 11 990 670 1320 800 ─────── ───────────────────────────── CIPig Red264 − 2520 1340 3750 1910 3 470 380 650 480 11 1120 640 1350 910 ─── ───────────────────────────────── CIPig Red27 0 − 3100 1920 2930 1750 5 530 380 650 530 11 1440 710 1500 980 ────────────────────────────────── ── CIPig Red272 − 1830 1260 1920 1780 7 420 390 540 510 11 1050 660 1130 840 ────────────────────────────── ────── CIPig Orange71 − 3440 2510 2620 2250 8 780 570 610 580 11 1860 820 1115 980 ────────────────────────── ────────── CIPig Orange73-2960 2040 3220 2330 9 630 490 470 450 11 1360 870 1050 860 ────────────────────── ──────────────

Table 2 Results of evaluation method (2) using diketopyrrolopyrrole-based pigment ─────── Pigment Pigment dispersant Formulation (1) Formulation (2) (%) (%) ───────────────────────── ─────────── CIPig Red254 − 35 30 1 90 95 11 80 80 ─────────────────────────── ───────── CIPig Red255 − 35 35 2 90 93 11 75 85 ───────────────────────────── ─────── CIPig Red264 − 35 40 3 90 90 11 82 77 ─────────────────────────────── ───── CIPig Red270 − 35 35 5 90 90 11 76 78 ───────────────────────────────── ─── CIPig Red272 − 40 40 7 95 94 11 80 85 ─────────────────────────────────── ─ CIPig Orange71 − 35 30 8 85 90 11 75 75 ──────────────────────────────────── CI Pig Orange 73 − 30 30 9 90 90 11 85 73 ────────────────────────────────────

Table 3 Results of evaluation methods (1) and (2) for other pigments ────── Pigment Pigment dispersant Formulation (1) Formulation (2) ────────────────────── Evaluation (1) Evaluation (2) Evaluation ( 1) Evaluation (2) ──────────────────────────────────── CIPig Red48: 1-× × × × (azo pigment) 1 △ ○ ○ ○ 2 ○ ○ ○ ○ ───────────────────────────────── ─── CIPig Red57: 1-× × × × (azo pigment) 3 △ △ ○ ○ 9 ○ ○ △ ○ ────────────────────── ────────────── CIPig Red168 − × × × × (Ansanthrone 6 ○ ○ △ ○ pigment) 9 △ ○ ○ ○ ─────────────────────────────────── CIPig Red177 − × × × × (Anthraquinone 6 ○ ○ △ ○ ○ ○ ○ ○ ──────────────────────────────────── CIPig Red178 − × × × × (perylene pigment) 2 ○ ○ ○ △ 10 ○ ○ △ △ ───────────────────────────────── ─── CIPig Orange43-× × × × (perinone pigment) 6 ○ ○ ○ ○ 8 △ ○ ○ ○ ──────────────────────── ──────────── CIPig Yellow12-× × × × (azo pigment) 1 ○ ○ ○ ○ 8 ○ ○ △ △ ─────────────── ───────────────────── CIPig Yellow24 − × × × × (Flavanslon 4 ○ ○ △ ○ pigment) 10 ○ △ ○ ○ ──────────────────────────────────── CIPig Yellow108 -× × × × (Ansrapyrimidine 6 △ △ ○ ○ pigment) 9 ○ ○ ○ ○ ───────────────────────────── ─────── CIPig Yellow139-× × × × (isoindoline 6 ○ ○ ○ ○ pigment) 8 ○ ○ △ ○ ─────────────────── ───────────────── CIPig Yellow150-× × × × (azo pigment) 6 ○ △ ○ △ 7 ○ ○ △ ○ ────────── ────────────────────────── CIPig Violet19 − × × × × (Quinacridone 3 ○ ○ ○ ○ pigment) 9 ○ ○ ○ ○ ─ ────────────────────────────── ──── CIPig Violet23 − × × × × (dioxazine 1 △ ○ △ ○ pigment) 7 ○ ○ △ ○ ─────────────────────── ───────────── CIPig Blue15 − × × × × (Phthalocyanine 2 △ ○ ○ ○ pigment) 9 ○ ○ △ △ ────────────── ────────────────────── CIPig Blue60 − × × × × (Indanthrone 5 ○ ○ △ ○ pigment) 9 ○ ○ △ △ ─── ───────────────────────────────── CIPig Black6-× × × × (Carbon 1 ○ ○ △ ○ Black) 3 △ ○ △ ○ ────────────────────────────────────

The pigment dispersant of the present invention exhibited an excellent dispersing effect on various pigments. Further, as shown in Tables 1 and 2, the pigment dispersant of the present invention was much more effective for diketopyrrolopyrrole pigments than the pigment dispersant disclosed in JP-A-3-26767. Excellent dispersing effect was exhibited. The reason for this is that the pigment dispersant of the present invention has a diketopyrrolopyrrole skeleton having an imino group and a carbonyl group involved in hydrogen bonding and has a large number of aromatic rings having a planar structure. This is presumed to be due to strong adsorption to. The effect of the pigment dispersant of the present invention is largely affected by the presence of the substituent (E), and does not affect the structural position of the substituent (E).

When these paints were left for one week and the viscosity was measured by the same method, almost no increase in the viscosity was observed. In addition, a 1 / 10-cut light-colored paint was prepared from a white paint prepared with titanium white, and the viscosity was adjusted to 2 with a Ford cup 4.
It was prepared for 3 seconds, taken into a test tube and observed for aggregation.
No color separation or sedimentation was observed even after one month. Further, when the pigment dispersant of the present invention was added, the pigment exhibited good dispersibility without causing aggregation even in nitrocellulose lacquer, acrylic resin paint and gravure ink.

[0043]

According to the present invention, when the pigment is dispersed in a non-aqueous vehicle using the pigment dispersant of the present invention, compared to the case of using the conventional pigment dispersant, the dispersion has a lower viscosity and a lower structural viscosity. Inks and paints exhibiting excellent fluidity and having no problems such as color separation and crystal change can be obtained. As a result, it is possible to obtain a printed product or a coated film with good gloss and thus a beautiful product. In addition, the pigment dispersant of the present invention has an extremely excellent dispersing effect not only in oil-modified amino alkyd resin paints but also in oil-free alkyd resin paints.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 17/00 C09D 17/00 // C07D 487/04 137 C07D 487/04 137 F term (Reference) 4C050 AA01 BB04 CC04 EE02 FF05 GG03 HH04 4D077 AA03 AA08 AB04 AB05 AB06 AC05 BA07 BA14 BA20 DC02Y DC04Y DC39Y DC42Y DC43Z DC45Z DC47Y DC48Y DC51Y DC53Y DC59Z DC73Z 4J037 AA30 CB16 CB18 CC24 CC27 CC24

Claims (3)

[Claims] 1. A pigment dispersant represented by the following formula (1). Formula (1)(However, DPP is a diketopyro represented by the following formula (2).
Represents a ropyrrole residue. Formula (2)E represents the following formula (3) or the following formula (4). Formula (3)Formula (4)R₁ ~ R₁₅: Independently, hydrogen atom, halogen atom
Or alkyl, alkoxy, cyano, sulfoni
, Carboxyl, dialkylamino, halogenoalkyl
, Alkoxycarbonyl, alkyl mercapto, cal
Represents a bamoyl or sulfamoyl group;₁ ~ R₁₅
At least one is a bond of E, and R₆ ~ R₁₅Little
At least one isIs a bond. m: represents an integer of 1 to 2. p: represents an integer of 1 to 4. X: direct bond, -SO_Two NH-, -CONH-, -CH
_Two NHCOCH_Two NH- or-(CH_Two ) QNH-
(Where q represents an integer of 1 to 10). n: represents an integer of 1 to 20. However, if X is a direct bond
In the case, it represents an integer of 1 to 10. R₁₆, R₁₇: Each independently may be substituted
A sum or unsaturated alkyl group, or R₁₆, R₁₇In
May be substituted containing an oxygen, oxygen or sulfur atom
Represents a heterocyclic ring. Z: -SO_Two -, -CO-, -CH_Two NHCOCH_Two 
-,-(CH_Two ) Q-, -SO_Two NH-, -CONH
-, -CH_Two NHCOCH_Two NH- or-(CH
_Two ) Represents qNH- (where q represents an integer of 1 to 10)
You. ). R₁₈, R₁₉, R₂₀, R_{twenty one}: Each independently a hydrogen atom,
Optionally substituted saturated or unsaturated alkyl
Represents a group or an aryl group. R_{twenty two}: Saturated or unsaturated alkyl which may be substituted
Represents a kill group or an aryl group. 2. A pigment composition comprising the pigment dispersant according to claim 1 and a pigment. 3. The pigment composition according to claim 2, wherein the pigment is a diketopyrrolopyrrole-based pigment.