JP3488001B2 - Pigment dispersant, coating composition and printing ink composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pigment dispersant and a composition containing the same. More specifically, when preparing a coating composition, a printing ink composition, etc., a dispersant used for improving the dispersibility of a pigment contained therein, and a coating composition or a printing ink composition containing the dispersant Regarding

[0002]

2. Description of the Related Art Conventionally, when preparing coating compositions, printing ink compositions, etc., the dispersibility of the pigments contained therein has been improved to improve the storage stability of coating materials, printing ink, etc. Various dispersants are used for the purpose of preventing the phenomenon of separation and improving the gloss of the coating film. For example, the dispersant used for such a purpose is generally a compound having a structure having a portion that is adsorbed by a pigment and a portion that is compatible with a vehicle for paint or ink. A conventionally known compound having such a structure has a polyester component and / or an acrylic resin component in the molecular chain.

A group that is easily adsorbed by a pigment (hereinafter referred to as "adsorbed group").
Sometimes called. ), Various functional groups are used, but many dispersants having an amino group in the molecular chain are known. For example, JP-A-53-103988
Japanese Patent Laid-Open No. 61-174 discloses low molecular weight amino compounds such as N, N-dimethylaminopropylamine.
Japanese Patent No. 939 describes a pigment dispersant using polyethyleneimine which is a high molecular weight amine compound.

These dispersants are adsorbed on the surface of the pigment at the highly polar amino groups in their molecular chains, and exhibit the effect as a pigment dispersant. Although these dispersants having an amino group in the molecular chain act extremely effectively on many inorganic pigments and some organic pigments, they have polar groups on the outside of the crystal structure like phthalocyanines. It could not effectively act on the pigments that did not exist, and could not exhibit a sufficient pigment dispersion effect.

[0005]

In order to improve this point, a method in which a pigment derivative such as phthalocyanine sulfonic acid is used in combination with a conventional pigment dispersant for phthalocyanine blue or phthalocyanine green is adopted. It has been effective to some extent. However, the derivatives of these pigments are highly colored, and there is a restriction that they can be used only when they do not affect the color tone of the pigment composition as a product, and even when they can be used. , Can not be used in large quantities,
It was not possible to exert a sufficient pigment dispersion effect.

[0006]

In view of the above situation, the present inventor provides a pigment dispersant that solves the problems and problems existing in the above-mentioned conventional techniques and a composition for paints or printing inks containing the same. As a result of repeated intensive studies for the purpose, a polyamine compound component modified with an aromatic group,
It was found that the reaction product obtained by reacting with a component containing a lactone significantly improves the dispersibility of the pigment and does not impair the original color tone of the pigment, and has completed the present invention. .

That is, the first aspect of the present invention is the polyamination.
Polyamide part of the amino group to an aromatic group modified with Fang obtained <br/> aromatic group-modified polyamine compound component of the compound (A component)
The remaining part of the amino group of the
Response: (a) of a lactone monomer represented by the general formula (1)
Addition reaction, (b) a poly (lactone) represented by the general formula (1)
Ester / amide exchange reaction of lactone compound, (c) piece comprising lactone represented by general formula (1)
Polyester polymer having (meth) acrylic group at the end
The present invention relates to a pigment dispersant composed of a reaction product obtained by carrying out an addition reaction of kutone (component B) .

[0008]

[Chemical 2]

A second aspect of the present invention is that a part of the remaining amino groups of the aromatic group-modified polyamine compound component (component A) obtained by modifying a part of the amino groups of the polyamine compound with an aromatic group. And (c) a pigment dispersant comprising a reaction product obtained by carrying out an addition reaction of a polyester polylactone having a (meth) acryl group at one end, which comprises the lactone represented by the general formula (1). The third aspect of the present invention is
The molecular weight of the polyamine compound is 100 to 100,000.
Within the range, the pigment dispersant according to the first or second aspect of the present invention. A fourth aspect of the present invention relates to the pigment dispersant according to any one of the first to third aspects of the present invention, in which the polyamine compound is polyethyleneimine, polyallylamine or polyvinylamine. A fifth aspect of the present invention is that the polyester compound component containing a lactone has an average molecular weight of 500 to 5,
The pigment dispersant according to any one of the first to fourth aspects of the present invention, which is in the range of 000. The sixth aspect of the present invention relates to the pigment dispersant according to any one of the first to fifth aspects of the present invention, which contains ε-caprolactone and methylcaprolactone alone or both as lactones. The seventh aspect of the present invention relates to the pigment dispersant according to any one of the first to sixth aspects of the present invention, which has an amine value within the range of 10 to 500 mgKOH / g. The eighth aspect of the present invention relates to the pigment dispersant according to any one of the first to seventh aspects of the present invention, wherein the pigment is a phthalocyanine pigment. The ninth aspect of the present invention is the first aspect of the present invention.
<8> A coating composition, wherein the pigment dispersant according to any one of <1> to <8> is used as a dispersant. Tenth of the present invention
Relates to a printing ink composition using the pigment dispersant according to any one of the first to eighth aspects of the present invention as a dispersant.

The present invention will be described in detail below. (Component A) Component A is a polyamine compound modified with an aromatic group. The polyamine compound modified with an aromatic group can be easily obtained by reacting an amino group of the polyamine compound with an aromatic compound having a functional group that reacts with the amino group.

As the polyamine compound which can be used for synthesizing the component A, there are industrially available primary, secondary,
A compound having a tertiary amino group can be used, but a compound having a molecular weight of 100 to 100,000 is preferable. When the molecular weight of the polyamine compound is less than 100, the amount of adsorbed groups per one molecule of amino group adsorbed on the pigment is small, and the adsorbed effect on the pigment is insufficient, so that the pigment does not exhibit a sufficient pigment dispersion effect. Alternatively, the dispersant is desorbed due to the shearing force during dispersion, which causes aggregation of the pigment, which is not preferable. On the other hand, the polyamine compound has a molecular weight of 100,000.
When it exceeds 0, the molecular weight of the dispersant becomes extremely large,
When a coating composition is prepared, it causes an increase in its viscosity, it becomes difficult to dissolve in the coating solvent, and the polyamine portion cross-links with the pigment, and thus the pigment tends to aggregate. , Etc. are not preferable. Particularly preferable in the above molecular weight range is 500 to 50,000.
Is the range. The molecular weight of the polyamine compound is a value measured by using both the GPC method and the calculated molecular weight based on the amine value.

As the polyamine compound, various industrially available polyamines can be used without limitation as long as they satisfy the above-mentioned molecular weight requirements. Specific examples include polyethyleneimine, polyallylamine, polyvinylamine and the like.

The aromatic compound having a functional group capable of reacting with the amino group of the polyamine compound is a compound capable of binding with an amino group through an amide bond, and aromatic carboxylic acids,
Aromatic isocyanates, aromatic acrylic acid esters, aromatic epoxy compounds and the like can be mentioned. The aromatic group is not particularly limited, but if the number of conjugated double bonds in the aromatic group is large, the product is likely to be colored, so an anthracene ring or naphthalene ring having a small number of conjugated double bonds, etc. Is desirable.

Specific compounds include benzoic acid, p-hydroxybenzoic acid, α-naphthoic acid, β-naphthoic acid,
2-quinolinecarboxylic acid, 8-hydroxyquinoline,
1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,
6-naphthalene diisocyanate, phenoxyethyl acrylate, naphthoxyethyl acrylate, glycidyl phthalimide, dibromobenzoic acid glycidyl ester and the like can be mentioned.

In order to modify the polyamine compound with the aromatic carboxylic acid, as described above, in addition to forming and introducing an amide bond between the polyamine compound and the aromatic carboxylic acid, 2,3-epoxycyclohexyl is introduced. It is also possible to introduce an epoxy (meth) acrylate such as methyl acrylate by reacting with an aromatic carboxylic acid and then introducing it by utilizing a Michael addition reaction of the acrylic group to the amino group. Further, in order to enhance the affinity with the pigment, it is also effective to modify the polyamine compound by Michael-adding an acrylic monomer or methacrylic monomer having a conjugated system to the polyamine compound. Examples of such an acrylic monomer include acrylonitrile, methacrylonitrile, styrene, α-methylstyrene, and styrene-sodium p-sulfonate.

(Component B) Component B is a polyester compound containing a lactone represented by the general formula (1).
Here, the lactone-containing polyester compound is one or more lactone ring-opening structural units alone represented by the general formula (1), or copolymerized with them in addition to the lactone ring-opening structural units. A compound containing a copolymer unit with other possible compounds.

The lactones represented by the general formula (1) include ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone, 4-methylcaprolactone, 2-methylcaprolactone and β-propiolactone. , Γ-butyrolactone and the like. These may be used alone or in combination of two or more as described above. In particular, by copolymerizing lactone having a side chain with caprolactone, it is possible to lower the melting point of the resulting pigment dispersant and to make the pigment dispersant a liquid state, improving the workability in the pigment dispersion step, It has an advantageous effect that problems such as precipitation of the pigment dispersant can be prevented. Among the lactones, ε-caprolactone, 4-methylcaprolactone, 2-methylcaprolactone, or a mixture thereof is particularly preferable.

Other compounds which can be copolymerized with lactones include hydroxycarboxylic acids, monofunctional carboxylic acids, and hydroxyl group-containing (meth) acrylates. Examples of hydroxycarboxylic acids include hydroxypivalic acid and 12-hydroxystearic acid.

[0019]

DETAILED DESCRIPTION OF THE INVENTION

(Synthesis Method of Pigment Dispersant) In order to react the component A and the component B, any of the following methods can be used. (A) Addition reaction of a lactone monomer to a polyamine compound, (b) ester / amide exchange reaction of a polylactone compound, (c) addition reaction to an amino group of a polyester polylactone having a (meth) acryl group at one end.

These methods will be described below. (A) Addition Reaction of Lactone Monomer to Polyamine Compound: In the addition reaction of lactone monomer to polyamine compound, the polyamine compound and the lactone monomer are heated in the presence of a catalyst and, if necessary, a solvent. It can be done by At this time, the ratio of the polyamines to the lactone monomers is preferably set so that the average molecular weight of the ring-opened lactone polymer chains produced is 500 to 5,000.

As the catalyst, tetrabutyl titanate,
Examples include titanium-based catalysts such as tetraisopropyl titanate, monobutyltin oxide, and stannous chloride, and tin-based catalysts. The amount of the catalyst used varies depending on the type, the types of both raw material components, the ratio thereof, the reaction temperature, the presence or absence of a solvent, the type, the amount used, etc., but it is preferably selected in the range of 1 to 3,000 ppm. If the amount of catalyst is less than 1 ppm, the reaction becomes extremely slow, and if it exceeds 3,000 ppm,
Neither is desirable, such as the product being colored or the pot life of the paint being impaired when blended into the paint.

The reaction temperature depends on the types of raw material components, their ratios,
It depends on the presence / absence of a solvent, its type, its usage amount, the presence / absence of a catalyst, its type, its usage amount, etc., but it is preferably selected in the range of 60 to 180 ° C. In the above temperature range, especially 80 ~
When the temperature is in the range of 120 ° C., an appropriate reaction rate can be obtained, and coloring of the product can be suppressed, which is preferable. When the reaction (a) is performed in a stream of an inert gas such as nitrogen gas, coloring of the product can be suppressed. When the reaction (a) is carried out in the presence of a suitable solvent, the temperature can be easily controlled and a uniform product can be obtained, which is preferable.

(B) Ester / amide exchange reaction of polylactone compound: The graft reaction of the polylactone to the polyamine compound is carried out by reacting the high molecular weight polylactone with the polyamine compound and utilizing the exchange reaction of the ester group and the amide group. You can also At this time, it is preferable that the ratio of the polyamine to the high-molecular-weight polylactone is set so that the average molecular weight of the lactone polymer chains produced is 500 to 5,000.

The temperature at which the reaction (b) is carried out varies depending on the types of raw material components, their ratios, the presence / absence of a solvent, their types, their usage amounts, the presence / absence of catalysts, their types, their usage amounts, etc. It is preferable to select in the range of 60 to 180 ° C. Within the above temperature range, particularly in the range of 80 to 120 ° C., an appropriate reaction rate can be obtained, and coloring of the product can be suppressed, which is preferable. When the reaction (b) is performed in a stream of an inert gas such as nitrogen gas, coloring of the product can be suppressed. When the reaction (b) is carried out in the presence of a suitable solvent, temperature control is easy and a uniform product can be obtained, which is preferable.

(C) Addition reaction of a polyester polylactone having a (meth) acrylic group at one end to an amino group:
The lactone grafting reaction to the polyamine compound can also be carried out by an addition reaction to the amino group of the polyester polylactone having a (meth) acryl group at one end (one end) of the molecular chain. Polyesters having a (meth) acrylic group at one end are hydroxyethyl (meth)
It can be produced by adding a lactone represented by the general formula (1) to a hydroxyl group-containing (meth) acrylate such as acrylate or hydroxypropyl (meth) acrylate or hydroxybutyl (meth) acrylate.

When carrying out the reaction (c), the reaction ratio of the hydroxyl group-containing (meth) acrylate and the lactone is such that the average molecular weight of the lactone polymer chain produced is 50.
It is desirable to set it to be 0 to 5,000.

The temperature at which the reaction (c) is carried out varies depending on the types of raw material components, their ratios, the presence / absence of a solvent, their types, their usage amounts, the presence / absence of catalysts, their types, their usage amounts, etc. It is preferable to select in the range of 50 to 180 ° C. It is particularly preferable that the temperature range is 70 to 120 ° C. in the above temperature range because an appropriate reaction rate can be obtained and the coloring of the product can be suppressed. It is preferable to carry out the reaction (c) in the presence of a suitable solvent, because the temperature can be easily controlled and a uniform product can be obtained. In addition, in order to prevent gelation of the (meth) acrylate, it is desirable to carry out in the presence of oxygen.

Polyesters having a (meth) acrylic group at one end used in the reaction (c) are hydroxycarboxylic acids such as hydroxypivalic acid and 12-hydroxystearic acid, or monofunctional compounds. It can be produced by reacting a carboxylic acid with a lactone represented by the general formula (1) to produce a polyester having a carboxyl group at one end and then reacting it with an epoxy group-containing (meth) acrylate. it can. The polyester preferably has an average molecular weight in the range of 500 to 5,000.

The temperature at which the polyester is reacted with the epoxy group-containing (meth) acrylate is 150 to 21.
By selecting at 0 ° C., an appropriate reaction rate can be obtained, and coloring of the product can be suppressed. When this reaction is carried out in a stream of an inert gas such as nitrogen gas, coloring of the product can be suppressed. When this reaction is carried out in the presence of a suitable solvent, temperature control is easy and a uniform product is obtained, which is preferable.

A carboxyl group-terminated polyester produced at the one end produced by the above method is reacted with an epoxy group-containing (meth) acrylate. Examples of the epoxy group-containing (meth) acrylate include glycidyl methacrylate, methylglycidyl methacrylate, and 2,3-epoxycyclohexylmethyl (meth) acrylate. This reaction is carried out in the presence of an amine-based or phosphorus-based catalyst such as tetramethylammonium chloride, dimethylbenzylamine, tetraphenylphosphonium chloride or triphenylphosphine in the presence of 50 to 120.
It can be carried out in the temperature range of ° C, and optionally in the presence of a solvent.

The reaction between the polyester compound having a (meth) acryl group at one end and the polyamine compound produced as described above is quantitative in the temperature range of 20 to 100 ° C. by mixing the two with heat generation. Then, the pigment dispersant according to the first aspect of the present invention is obtained.

According to the experiments conducted by the present inventor, the pigment dispersant according to the first aspect of the present invention has an amine value of 10 to 500 mg.
The range of KOH / mg is preferred. Amine value is 10mgK
If it is less than OH / mg, the concentration of amino groups adsorbed on the pigment is too low and the pigment does not exhibit a sufficient pigment dispersing action, which is not preferable. On the other hand, when the amount exceeds 500 mgKOH / mg, the polyester portion is too small and the steric repulsion is too low to show sufficient dispersion stability of the pigment, which is not preferable.

(Method of Using Pigment Dispersant) The pigment dispersant according to the first aspect of the present invention is mixed with a pigment, a magnetic material, or other additives and dispersed by a known method to prepare a coating composition or printing. It can be used as an ink composition. That is, a coating composition and a printing ink composition can be obtained by dispersing a pigment, the present dispersant, a coating resin, and an appropriate solvent with a disperser and then blending the coating and the ink resin. The pigment dispersant according to the present invention has an adsorbable group that is easily adsorbed by a pigment when used in these applications, and therefore has sufficient adsorbability, and therefore has a pigment dispersibility, a mill-base fluidity, and a pigment dispersion. It exerts the function of improving storage stability, etc.

Examples of pigments that can be used in combination with the pigment dispersant according to the present invention include inorganic pigments and organic pigments. The inorganic pigments include titanium oxide, zinc oxide, cadmium sulfide, yellow iron oxide, red iron oxide, yellow lead, carbon black, and the like, and the organic pigments include phthalocyanines, insoluble azo pigments, azo lake pigments, and condensed polycyclic pigments. (Slen-based, indigo-based, perylene-based, perinone-based,
Phthalone-based, dioxazine-based, quinacridone-based, isoindolinone-based, diketopyrrolopyrrole-based pigments) and the like.

As the paint resin which can be used in combination with the present dispersant, general paint resins can be preferably used, and alkyd resin, oil-free alkyd resin, acrylic resin, urethane resin and the like are preferable. . Further, as other additives, a leveling agent, a defoaming agent, etc. can be used.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited as long as the gist thereof is not exceeded.
The present invention is not limited to the following description example. In the following description examples, all "parts" indicate parts by weight. Moreover, in the following examples, the amine value and the oxirane oxygen concentration are measured by the methods described below.

(1) Molecular weight of polyamine: The molecular weight calculated by GPC method and amine value was used together. (2) Molecular weight of polycaprolactone: Measured by ¹ H-NMR method (JEOL JNM EX-270, CDCl ₃ solvent, room temperature). (3) Confirmation of the presence or absence of a double bond in the reaction mixture: The disappearance of the signal of the double bond was confirmed by ¹ H-NMR method (JEOL JNM EX-270, CDCl ₃ solvent, room temperature). (4) Amine value: Titrated by the hydrochloric acid method. (5) Oxylan oxygen concentration: According to the HBr-acetic acid method.

Example 1: Synthesis of "Dispersant 1" Polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd.) was placed in a glass reaction flask of 1 liter capacity equipped with a nitrogen gas inlet tube, a dehydration tube, a reflux condenser and a stirrer. SP-200 ", molecular weight 10,0
00) 100 parts and β-naphthoic acid 15 parts were charged respectively. While stirring the contents of the flask, the internal temperature was raised to 150 ° C. under a nitrogen gas stream, and the reaction was carried out at this temperature. The reaction is stopped when 1.6 parts of water is stored in the dehydration tube,
Then, the temperature inside the flask was cooled to 60 ° C., and 885 parts of an acrylic group-containing polycaprolactone (“PCL FA-12” manufactured by Daicel Chemical Industries, Ltd.) in which 12 mol of caprolactone was added to hydroxyethyl acrylate was added.
For the sample sampled during the reaction, the reaction was continued while confirming the presence or absence of a double bond, and the reaction was terminated after confirming the disappearance of the double bond. The amine value of the product was measured and found to be 87 mgKOH / g. The product obtained is called "dispersant 1".

(Preparation of Pigment Dispersion Paste) Phthalocyanine Blue (“Chromophine Blue 4” manufactured by Dainichi Seika Kogyo Co., Ltd.)
920 ": C.I. I-Pigment Blue 15:
3) 25 parts, "Dispersant 1" 10 parts, xylene 32.5
Parts, butyl cellosolve acetate 32.5 parts, and glass beads 100 parts were weighed and treated with a disperser (manufactured by Red Devil Co.) for 60 minutes to disperse. The obtained pigment-dispersed paste exhibits good fluidity and has a room temperature of 1
Good fluidity was exhibited even after standing for a week.

Example 2: Synthesis of "Dispersant 2" In the same glass reaction flask used in Example 1, 100 parts of polyethyleneimine (same as used in Example 1),
15 parts of 2,4-dibromobenzoic acid glycidyl ester (“Denacol EX-147” manufactured by Nagase Kasei Co., Ltd.) were charged. While stirring the contents of the flask, the internal temperature was raised to 110 ° C. under a nitrogen gas stream, and the reaction was carried out at this temperature. For the sample sampled during the reaction, the oxirane oxygen concentration was analyzed, the reaction was stopped when this became 0.1% or less, and then the temperature inside the flask was cooled to 60 ° C.
12 caprolactone in hydroxyethyl acrylate
885 parts of the polycaprolactone containing the added acrylic group (the same as that used in Example 1) was added. For the sample sampled during the reaction, the reaction was continued while confirming the presence or absence of a double bond, and the reaction was terminated after confirming the disappearance of the double bond. The amine value of the product was measured and found to be 90 mgKOH / g. The product obtained is called "dispersant 2".

(Preparation of Pigment Dispersion Paste) Phthalocyanine Green ("Chromophine Green 5310" manufactured by Dainichiseika Kogyo Co., Ltd .: CI Pigment Green 7)
25 parts, 10 parts of "dispersant 2", 65 parts of xylene, and 100 parts of glass beads were weighed and treated with a disperser (manufactured by Red Devil Co.) for 60 minutes to disperse. The obtained pigment-dispersed paste exhibits good fluidity and has a room temperature of 1
Good fluidity was exhibited even after standing for a week.

Example 3: Synthesis of "Dispersant 3" In the same glass reaction flask used in Example 1, 100 parts of polyethyleneimine (same as that used in Example 1),
Glycidyl phthalimide ("Denacol E" manufactured by Nagase Kasei Co., Ltd.
X-731 ") 10 parts were charged. While stirring the contents of the flask, the internal temperature was 110 ° C under a nitrogen gas stream.
The temperature was raised to the reaction temperature. The oxirane oxygen concentration of the sample sampled during the reaction was analyzed, the reaction was stopped when the oxirane oxygen concentration became 0.1% or less, then the flask internal temperature was cooled to 60 ° C., and 8 mol of caprolactone was added to hydroxyethyl acrylate. -Methylcaprolactone 4m
885 parts of acryl group-containing caprolactone (molecular weight 1540) to which ol was added was added. For the sample sampled during the reaction, the reaction was continued while confirming the presence or absence of a double bond, and the reaction was terminated after confirming the disappearance of the double bond. When the amine value of the product was measured, it was 89 m.
It was gKOH / g. The product obtained is called "dispersant 3".

(Preparation of Pigment Dispersion Paste) Phthalocyanine Blue (“Chomo Fine Blue 49” manufactured by Dainichi Seika Kogyo Co., Ltd.)
20 ": C.I. I-Pigment Blue 15: 3)
25 parts, "Dispersant 3" 10 parts, xylene 32.5 parts, tylcellosolve acetate 32.5 parts, glass beads 10
Disperser (manufactured by Red Devil Co.)
And treated for 60 minutes to disperse. The obtained pigment-dispersed paste showed good fluidity, and even after left at room temperature for 1 week, it showed good fluidity.

[Comparative Example 1] A pigment-dispersed paste was prepared in the same manner as in Example 1 except that "Dispersant 1" was not added. The obtained pigment-dispersed paste did not show fluidity.

[0045]

INDUSTRIAL APPLICABILITY The present invention has the following particularly advantageous effects, and its industrial utility value is extremely large. 1. The pigment dispersant according to the present invention has polyamines having an aromatic group as an adsorbed group of the pigment in the molecule, and has a structure in which a side chain is grafted with polylactone, so that it has been difficult to disperse the pigment. It is extremely effective for dispersing organic pigments such as phthalocyanine. 2. Since the pigment dispersant according to the present invention is colorless, unlike the conventional case where a highly colored pigment derivative is used as the dispersant, the original color tone of the pigment is not impaired.

Claims (10)

(57) [Claims] 1. A polyamine compound of an aromatic group-modified polyamine compound component (component A) obtained by modifying a part of amino groups of a polyamine compound with an aromatic group. Reaction: (a) addition reaction of a lactone monomer represented by the general formula (1), (b) ester / amide exchange reaction of a polylactone compound composed of the lactone represented by the general formula (1), (c) A pigment dispersant comprising a reaction product obtained by performing an addition reaction of a polyester polylactone (component B) having a (meth) acryl group at one end, which is composed of a lactone represented by the general formula (1). [Chemical 1] 2. An aromatic group-modified polyamine compound component (component A) obtained by modifying a part of the amino groups of a polyamine compound with an aromatic group, and the remaining part of the amino groups of (c) the general formula A pigment dispersant comprising a reaction product obtained by carrying out an addition reaction of a polyester polylactone having a (meth) acryl group at one end, which comprises the lactone represented by (1). 3. The polyamine compound has a molecular weight of 100 to 100.
The pigment dispersant according to claim 1 or 2, which is in the range of 100,000. 4. The pigment dispersant according to claim 1, wherein the polyamine compound is polyethyleneimine, polyallylamine or polyvinylamine. 5. The pigment dispersant according to claim 1, wherein the polyester compound component containing the lactone has an average molecular weight in the range of 500 to 5,000. 6. Epsilon-caprolactone as a lactone,
The pigment dispersant according to any one of claims 1 to 5, which contains each of methylcaprolactone alone or both of them. 7. An amine value of 10 to 500 mg KOH /
The pigment dispersant according to any one of claims 1 to 6, which is in the range of g. 8. The pigment dispersant according to claim 1, wherein the pigment is a phthalocyanine pigment. 9. A coating composition comprising the pigment dispersant according to any one of claims 1 to 8 as a dispersant. 10. A printing ink composition comprising the pigment dispersant according to claim 1 as a dispersant.