JP7533037B2 - Pigment composition, photosensitive pigment composition, color filter and display device - Google Patents

Description

The present invention relates to a pigment composition used in the manufacture of color filters for displays, solid-state imaging devices, etc.

Conventionally, pigment compositions used in inkjet inks, color filter compositions and the like have required fine dispersion of the pigment depending on the mode of use.
In particular, for color filter applications, fine dispersion of pigments is required as the definition and resolution of liquid crystal televisions, smartphones, solid-state imaging devices, etc. increase. However, finer pigments lead to poorer dispersion stability, which can lead to pigment aggregation and increased viscosity. In order to stably disperse finer pigments, a large amount of dispersant must be used, which results in problems such as reduced developability, reduced brightness due to yellowing of the dispersant, and insufficient coloring power due to reduced pigment concentration. For this reason, it has been difficult to meet all of the various high physical property requirements in recent years, such as high brightness, high coloring power, fastness such as heat resistance, and developability, in addition to finer pigments.

Patent Documents 1 and 2 disclose pigment compositions that contain a basic dispersant of a block polymer.

WO2010/016523 JP 2014-058672 A

However, when the dispersant of Patent Document 1 is used, although the pigment stability is good, there is a problem that the use of only a basic dispersant results in inferior developability compared to the use of an acidic dispersant. Furthermore, when the dispersant of Patent Document 2 is used, since it has a block having a quaternary ammonium base, the hydrophilicity of the dispersant is high, and there is a problem that the viscosity stability over time of the pigment composition is low when stored at a temperature above 25°C.

The present invention aims to provide a pigment composition that has excellent storage stability at temperatures above 25°C and can form a coating that has excellent heat resistance, high brightness, and developability.

The pigment composition of the present invention comprises a pigment (A), a basic dispersant (B), and an acidic dispersant (C),
The basic dispersant (B) is an A-B or B-A-B block polymer synthesized by living radical polymerization, in which the A block has product units of a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group, and the B block has monomer units of a (meth)acrylic acid ester.

According to the present invention, it is possible to provide a pigment composition, a photosensitive pigment composition, a color filter, and a display device that can form a coating having excellent storage stability at temperatures exceeding 25°C, and excellent heat resistance, high brightness, and developability.

The terms used in this specification are defined. When written as "(meth)acryloyl", "(meth)acrylic", "(meth)acrylic acid", "(meth)acrylate", and "(meth)acryloyloxy", unless otherwise specified, they respectively mean "acryloyl and/or methacryloyl", "acrylic and/or methacrylic", "acrylic acid and/or methacrylic acid", "acrylate and/or methacrylate", and "acryloyloxy and/or methacryloyloxy". A monomer is an ethylenically unsaturated group-containing monomer. An isocyanate group-reactive functional group is a functional group that reacts with an isocyanate group. A monomer and a monomer are synonymous.

The pigment composition of the present invention comprises a pigment (A), a basic dispersant (B), and an acidic dispersant (C),
The basic dispersant (B) is an A-B or B-A-B block polymer synthesized by living radical polymerization, the A block having a product unit of a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group, and the B block having a monomer unit of a (meth)acrylic acid ester. The pigment composition of the present invention is preferably used for forming a color filter.

In the present invention, the basic dispersant (B) is an A-B block polymer or a B-A-B block polymer,
The A block has a product unit of a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group.
Examples of the functional group capable of reacting with an isocyanate group include a primary amino group, a secondary amino group, a hydroxyl group, etc. Examples of the functional group capable of reacting with an epoxy group include a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, etc.

The aromatic nitrogen-containing heterocyclic group of the A block is located in a side chain of the polymer, which is the terminal of the product unit reacted with a monomer unit having an isocyanate group or an epoxy group, and therefore is easily adsorbed to the pigment, improving the dispersion stability of the pigment. In particular, when used to disperse a pigment having an aromatic ring, the A block of the basic dispersant (B) is sufficiently adsorbed to the pigment, so that the basic dispersant (B) is unlikely to come off from the pigment even when stored at a temperature of 25°C or higher. Therefore, the storage stability is excellent.
The B block is a polymer block having a monomer unit of a (meth)acrylic acid ester. The B block has a high affinity for materials other than the pigment (A) and has a steric repulsion function, which contributes to dispersion stability that suppresses aggregation of pigments.

<Pigment (A)>
The pigment (A) may be an organic or inorganic pigment, and may be used alone or in combination of two or more kinds. Among the pigments, one or more kinds selected from the group consisting of azo pigments, diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, indole pigments, quinophthalone pigments, phthalocyanine pigments, and dioxazine pigments are preferred, and azo pigments are more preferred.
Representative pigments that can be used in the pigment composition of the present invention are listed below.

Red pigments include, for example, C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 50:1, 52:1, 52:2, 53, 53:1, 53:2, 53:3, 57, 57:1, 57:2, 58:4, 60, 63, 63:1, 63:2, 64, 64:1, 68, 69, 81, 81:1, 81:2, 81:3, 81:4, 83, 88, 90:1, 101, 101:1, 104, 108, 108:1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151, 166, 168, 169, 170, 172, 173, 174, 17 5,176,177,178,179,181,184,185,187,188,190,193,194,200,202,206,207,208,209,210,214,216,220,221,224,230,231,232,233,235,236 , 237, 238, 239, 242, 243, 245, 247, 249, 250, 2 51, 253, 254, 255, 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287, 291, 295, 296, etc.

Yellow pigments include, for example, C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 1 20, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 192, 193, 194, 196, 198, 199, 213, 214, 231, 233, etc.

Examples of blue pigments include C.I. Pigment Blue 1:2, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 19, 25, 27, 28, 29, 33, 35, 36, 56, 56:1, 60, 61, 61:1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, and 79.

Examples of purple pigments include C.I. Pigment Violet 1, 1:1, 2, 2:2, 3, 3:1, 3:3, 5, 5:1, 14, 15, 16, 19, 23, 25, 27, 29, 31, 32, 37, 39, 42, 44, 47, 49, and 50.

Examples of green pigments include C.I. Pigment Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 37, 45, 48, 50, 51, 54, 55, 58, 59, 62, and 63.

Examples of inorganic pigments include titanium oxide, barium sulfate, zinc oxide, lead sulfate, yellow lead, zinc yellow, red iron oxide (red iron (III) oxide), cadmium red, ultramarine, Prussian blue, chromium oxide green, cobalt green, amber, and synthetic iron black.

<Minification of pigment>
In this specification, it is preferable that the pigment is finely milled before being mixed with other materials. Examples of the fine-milling method include wet grinding, dry grinding, and solution precipitation. In this specification, salt milling treatment using a kneader method, which is a type of wet grinding, is preferable.

The average primary particle diameter of the pigment after micronization is preferably 20 to 100 nm, more preferably 25 to 85 nm. Having an appropriate average primary particle diameter improves dispersibility and contrast ratio. The average primary particle diameter of the pigment was measured (calculated) by the following method. Propylene glycol monomethyl ether acetate was added to the pigment powder, a small amount of Disperbyk-161 (manufactured by BYK Japan) was added as a resin-type dispersant, and the mixture was dispersed for 1 minute in an ultrasonic cleaner to prepare a measurement sample. Three photographs (three fields of view) of this sample in which 100 or more primary particles of the pigment could be confirmed were taken using a transmission electron microscope (JEM-1200EX manufactured by JEOL Ltd.), and the size of 100 primary particles was measured in order from the top left of each photograph. Specifically, the minor axis diameter and major axis diameter of the primary particles of each pigment were measured in nm units, and the average was taken as the primary particle diameter of that pigment. A total of 300 particles were distributed in 5 nm increments, and the median value of the 5 nm increments (e.g., 8 nm for particles between 6 nm and 10 nm) was approximated as the particle diameter of those particles. The number-average particle diameter was calculated based on each particle diameter and its number.

The salt milling treatment is a treatment in which a mixture of a pigment, a water-soluble inorganic salt, and a water-soluble organic solvent is mechanically kneaded while being heated using, for example, a batch or continuous kneader such as a kneader, a two-roll mill, a three-roll mill, a ball mill, an attritor, a sand mill, or a planetary mixer, and then the water-soluble inorganic salt and the water-soluble organic solvent are removed by washing with water.
The water-soluble inorganic salt acts as a grinding aid, and the high hardness of the inorganic salt is used to grind the pigment during salt milling. By optimizing the conditions for salt milling the pigment, it is possible to obtain a pigment with a very fine primary particle size, a narrow distribution range, and a sharp particle size distribution.

Examples of water-soluble inorganic salts include sodium chloride, potassium chloride, and sodium sulfate. Among these, sodium chloride (table salt) is preferable because it is inexpensive. From the viewpoints of both processing efficiency and production efficiency, it is preferable to use 50 to 2,000 parts by mass of water-soluble inorganic salts per 100 parts by mass of pigment, and more preferably 300 to 1,000 parts by mass.

The water-soluble organic solvent can wet the pigment and the water-soluble inorganic salt. The water-soluble organic solvent may be any solvent that dissolves (is miscible with) water and does not substantially dissolve the inorganic salt used. In this specification, the temperature rises during salt milling, and the solvent becomes prone to evaporate, so from the standpoint of safety, a high-boiling point solvent with a boiling point of 120°C or higher is preferred. Examples of water-soluble organic solvents that can be used include 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, liquid polypropylene glycol, etc. The water-soluble organic solvent is preferably used in an amount of 5 to 1,000 parts by weight, and most preferably 50 to 500 parts by weight, per 100 parts by weight of the pigment.

When the pigment is subjected to salt milling, a resin may be added as necessary. There are no particular limitations on the type of resin used, and natural resins, modified natural resins, synthetic resins, synthetic resins modified with natural resins, etc. can be used. The resin used is preferably solid at room temperature and insoluble in water, and more preferably partially soluble in the above organic solvents. The amount of resin used is preferably in the range of 5 to 200 parts by mass per 100 parts by mass of the pigment.

<Basic Dispersant (B)>
The basic dispersant (B) is an A-B block polymer or a B-A-B block polymer synthesized by living radical polymerization. The A block of the basic dispersant (B) has product units of a compound having a nitrogen-containing heterocyclic group with aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group. The B block of the basic dispersant (B) has monomer units of a (meth)acrylic acid ester.

When synthesizing a block polymer, for example, an A-B block polymer can be produced by first synthesizing the A block and then the B block. Alternatively, a B-A-B block polymer can be produced by first synthesizing the B block, then the A block, and then the B block. It goes without saying that the order in which the A block and the B block are synthesized is arbitrary.

The radical polymerization initiator used in the living radical polymerization is preferably, for example, an azo compound or a peroxide. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(methyl isobutyrate), 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), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]. Examples of peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide.

Polymerization initiators can be used alone or in combination of two or more types.

The polymerization reaction temperature is preferably 40 to 150°C, more preferably 50 to 110°C. The reaction time is preferably 3 to 30 hours, more preferably 5 to 20 hours.

The living radical polymerization can be carried out by a known polymerization method, and is preferably carried out by RAFT polymerization (reversible addition-fragmentation chain transfer polymerization).
RAFT polymerization is a method of radically polymerizing a monomer in the presence of a RAFT agent, and makes it easy to control the molecular weight and molecular weight distribution of the polymer.

RAFT agents are compounds having a chain transfer effect and a polymerization initiation effect, and examples thereof include dithiobenzoate type, trithiocarbonate type, dithiocarbamate type, xantheto type, etc., as well as disulfide type, which is a precursor thereof. Examples of dithiobenzoate type include 2-cyano-2-propyl dithiobenzoate, 4-cyano-4-(thiobenzoylthio)pentanoic acid, and 2-phenyl-2-propyl benzodithioate.
Examples of trithiocarbonate type include 4-[(2-carboxyethylsulfanylthiocarbonyl)sulfanyl]-4-cyanopentanoic acid, 2-{[(2-carboxyethyl)sulfanylthiocarbonyl]sulfanyl}propanoic acid, 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid, 2-cyano-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propane, 2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid methyl, 2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propanoic acid, S,S-dibenzyltrithiocarbonic acid, trithiocarbonic acid=bis[4-(allyloxy) dithiocarbamate-type compounds include, for example, 4-chloro-3,5-dimethylpyrazole-1-carbodithioic acid 2'-cyanobutan-2'-yl, 3,5-dimethylpyrazole-1-carbodithioic acid 2'-cyanobutan-2'-yl, 3,5-dimethylpyrazole-1-carbodithioic acid 2'-cyanobutan-2'-yl, 3,5-dimethylpyrazole-1-carbodithioic acid cyanomethyl, and N-methyl-N-phenyldithiocarbamate cyanomethyl.
Examples of the disulfide type include bis(dodecylsulfanylthiocarbonyl) disulfide, bis(thiobenzoyl) disulfide, etc. These are preferred for producing an AB block polymer.

Among these, trithiocarbonate type compounds are preferred because the reaction during synthesis can be easily controlled, and 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid, 2-cyano-2-[(dodecylsulfanylthiocarbonyl)sulfanyl]propane, methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate, bis{4-[ethyl-(2-hydroxyethyl)carbamoyl]benzyl} trithiocarbonate, and bis(dodecylsulfanylthiocarbonyl)disulfide are more preferred.

The amount of RAFT agent used is preferably 0.1 to 10 parts by mass per 100 parts by mass of monomer.

The basic dispersant (B) is preferably synthesized using an organic solvent. Examples of organic solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

Organic solvents can be used alone or in combination of two or more types.

<A Block>
The A block has a product unit of a compound having an aromatic nitrogen-containing heterocyclic group and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group. The A block is easily adsorbed to the pigment (A) because the aromatic nitrogen-containing heterocyclic group is located near the end of the side chain. Therefore, when the pigment composition is stored at a temperature higher than room temperature, the basic dispersant (B) is unlikely to be detached from the pigment (A), and excellent storage stability is obtained. The A block is preferably formed by reacting a monomer unit having an isocyanate group or an epoxy group with a compound having an aromatic nitrogen-containing heterocyclic group and a functional group capable of reacting with an isocyanate group or an epoxy group. The monomer unit having an isocyanate group or an epoxy group before the reaction is also called an A block precursor.

The ratio of the compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group in all structural units in the A block is not particularly limited as long as the problem can be solved, but if it is 30 mol % or more, the adsorption to the pigment is improved and the stability over time is improved, and is preferably 30 to 100 mol %, more preferably 50 to 100 mol %, and even more preferably 80 to 100 mol %.

<Compound Having Nitrogen-Containing Heterocyclic Group Having Aromaticity and Functional Group Reactive with Isocyanate Group or Epoxy Group>
Examples of the functional group capable of reacting with an isocyanate group include a primary amino group, a secondary amino group, a hydroxyl group, etc. Examples of the functional group capable of reacting with an epoxy group include a carboxyl group, a primary amino group, a secondary amino group, etc.

Examples of the compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group include a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group and an epoxy group, a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group, and a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an epoxy group.

Examples of compounds having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group and an epoxy group include 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-(aminomethyl)pyridine, 3-(aminomethyl)pyridine, 4-(aminomethyl)pyridine, 1-(2-pyridyl)piperazine, 1-(4-pyridyl)piperazine, 1-(2-pyrimidyl)piperazine, bis-2-picolylamine, 2-amino-1H-imidazole, and 1H-imidazole-4-ethane. Examples of the compound include amine, 2-amino-1H-benzimidazole, 1-(3-aminopropyl)imidazole, 5-amino-2-benzimidazolinone, 2-amino-N-ethylcarbazole, 3-amino-9H-carbazole, 3-(aminoethyl)-9-methyl-9H-carbazole, 3-(aminomethyl)-9-methyl-9H-carbazole, 8-aminoquinoline, 9-aminoacridine, 1-(3-aminopropyl)-2-pyrrolidone, imidazole, pyrazole, 1,2,4-triazole, etc. Among these, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-(aminomethyl)pyridine, 3-(aminomethyl)pyridine, 4-(aminomethyl)pyridine, 1-(3-aminopropyl)imidazole, 5-amino-2-benzimidazolinone, and 3-amino-9H-carbazole are preferred. In these compounds, the functional group of the A block precursor corresponds to both an isocyanate group and an epoxy group. Note that N in the above compounds means that the hydrogen atom of the heterocyclic amino group is unsubstituted.

Examples of compounds having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group include 2-pyridinemethanol, 3-pyridinemethanol, 3-pyridinemethanol, 2-pyridineethanol, 3-pyridineethanol, and 4-pyridineethanol.

Examples of compounds having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an epoxy group include pyridine-2-carboxylic acid, pyridine-3-carboxylic acid, pyridine-4-carboxylic acid, 3-(3-pyridyl)propionic acid, and 5-quinolinecarboxylic acid.

Examples of isocyanate group-containing monomers include 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, 2-(2-isocyanatoethoxy)ethyl methacrylate, and 3-isopropenyl-α,α-dimethylbenzyl isocyanate. Among these, 2-isocyanatoethyl methacrylate and 2-isocyanatoethyl acrylate are preferred from the viewpoints of polymerizability and reactivity of the isocyanate group.

Examples of epoxy group-containing monomers include (meth)acrylates such as glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexyl (meth)acrylate, (meth)acryloyloxyethyl glycidyl ether, (meth)acryloyloxyethoxyethyl glycidyl ether, and vinyl monomers such as glycidyl vinyl ether and allyl glycidyl ether.

Examples of methods for synthesizing the A block include (1) a method of reacting a polymer of an isocyanate group-containing monomer with a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group, (2) a method of reacting a polymer of an isocyanate group-containing monomer with a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group, and then polymerizing the resulting mixture, (3) a method of reacting a polymer of an epoxy group-containing monomer with a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an epoxy group, and (4) a method of reacting a polymer of an epoxy group-containing monomer with a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an epoxy group, and then polymerizing the resulting mixture, and the like.

<Block B>
The B block is a polymer block containing a (meth)acrylic acid ester unit. The (meth)acrylic acid ester constituting the (meth)acrylic acid ester unit is a monomer that does not contain a reactive functional group. Examples of the (meth)acrylic acid ester include linear and alicyclic alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate; and aromatic ring (meth)acrylates such as benzyl (meth)acrylate and phenylethyl (meth)acrylate.

The (meth)acrylic acid esters can be used alone or in combination of two or more types.

The B block may further contain a monomer unit containing a reactive functional group, an alkyleneoxy group-containing monomer unit, or other monomer unit. Examples of the monomer containing a reactive functional group include (meth)acrylates having a blocked isocyanate group, such as KarenzMOI-BM and KarenzMOI-BP (manufactured by Showa Denko K.K.); (meth)acrylates having an oxetane group, such as (3-ethyloxetan-3-yl)methyl (meth)acrylate; (meth)acrylates having a tert-butyl group, such as tert-butyl (meth)acrylate; (meth)acrylates containing a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate; (meth)acrylates containing a carboxyl group, such as (meth)acrylic acid; (meth)acrylates containing a sulfonic acid group, such as ethyl sulfonate (meth)acrylate, and a phosphoric acid group, such as methacryloyloxyethyl phosphate. When a monomer having an isocyanate group is used in the synthesis of the A block, a reaction occurs when a hydroxyl group-containing (meth)acrylate and a carboxyl group-containing (meth)acrylate are used in the synthesis of the B block. Therefore, it is preferable to use a method in which an isocyanate group-containing monomer is reacted with a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group, as in the synthesis of the A block (2), and then polymerized.

It can be formed from an alkyleneoxy group-containing monomer of an alkyleneoxy group-containing monomer unit. Examples of the alkyleneoxy group include an ethyleneoxy group, a propyleneoxy group, and a butyleneoxy group. Among these, an ethyleneoxy group and a propyleneoxy group are more preferable in terms of improving developability and resolution. Examples of the alkyleneoxy group-containing monomer include polyethylene glycol (n = 1 to 30) methyl ether (meth)acrylate, polyethylene glycol (n = 1 to 30) ethyl ether (meth)acrylate, polyethylene glycol (n = 1 to 30) propyl ether (meth)acrylate, polypropylene glycol (n = 1 to 30) methyl ether (meth)acrylate, polypropylene glycol (n = 1 to 30) ethyl ether (meth)acrylate, and polypropylene glycol (n = 1 to 30) propyl ether (meth)acrylate. Among these, a polyethylene glycol (n = 1 to 30) methyl ether (meth)acrylate having 1 to 30 ethyleneoxy groups is preferable in terms of improving storage stability. Note that n indicates the average number of alkyleneoxy groups.

The other monomer units can be formed from other monomers. Examples of other monomers include styrene-based monomers such as styrene and α-methylstyrene, (meth)acrylamide-based monomers such as (meth)acrylamide, N-methylolacrylamide, and 2-hydroxyethyl(meth)acrylamide, vinyl acetate, and N-methacryloylmorpholine.

In the case of an A-B block polymer, the molar ratio of the A block and the B block of the pigment dispersant (B) is preferably A/(A+B)=5-70 mol%, more preferably 15-50 mol%. Similarly, in the case of a B-A-B block polymer, A/(A+B)=10-70 mol%, more preferably 15-50 mol%. When used at an appropriate ratio, the initial viscosity can be suppressed and storage stability is further improved.

In this specification, the basic dispersant (B) is preferably an A-B block polymer in terms of dispersion stability.

The amine value of the basic dispersant (B) is preferably 10 to 200 mgKOH/g, more preferably 20 to 150 mgKOH/g, and even more preferably 30 to 100 mgKOH/g. Having a suitable amine value improves the adsorption to the pigment (A) and improves the solubility in the solvent, thereby further improving the dispersion stability.

The weight average molecular weight of the basic dispersant (B) is preferably 3,000 to 80,000, and more preferably 5,000 to 50,000. Having an appropriate molecular weight further improves dispersion stability. The weight average molecular weight is a value measured by gel permeation chromatography (GPC). The molecular weight distribution (weight average molecular weight/number average molecular weight) of the basic dispersant (B) is preferably 1.05 to 2.5, and more preferably 1.05 to 1.8.

<Acidic Dispersant (C)>
The acidic dispersant (C) is a resin-type dispersant having an acidic group that has affinity with the basic group of the basic dispersant (B). The inclusion of the acidic dispersant (C) improves the ionic stability compared to the case where only a basic dispersant is used, and therefore improves the storage stability of the pigment composition. Examples of the acidic dispersant (C) include polyurethane, polycarboxylates, unsaturated polyamides, polycarboxylic acids, polycarboxylate (partial) amine salts, polycarboxylate ammonium salts, polycarboxylate alkylamine salts, polysiloxanes, long-chain polyaminoamide phosphates, and hydroxyl-containing polycarboxylates, as well as modified products thereof; oil-based dispersants such as amides formed by the reaction of poly(lower alkyleneimines) with polyesters having free carboxyl groups, and salts thereof; (meth)acrylic acid-styrene copolymers, (meth)acrylic acid-(meth)acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, and water-soluble resins and water-soluble polymer compounds such as polyvinylpyrrolidone, polyesters, modified polyacrylates, ethylene oxide/propylene oxide adducts, and phosphate esters.

Commercially available acidic dispersants (C) include Disperbyk-101, 102, 103, 106, 110, 111, 130, 140, 142, 145, 170, 171, 174, 180, 2001, 2020, 2025, and 2070 manufactured by BYK Japan Co., Ltd., and BYK-P104, P104S, and 220S manufactured by Nippon Lu Examples include SOLSPERSE-3000, 21000, 26000, 36000, 36600, 41000, 41090, 43000, 44000, 46000, 53095, and 55000 manufactured by Ajinomoto Fine-Techno Co., Ltd., and AJISPER PA111, PN411, PB821, and PB822 manufactured by Ajinomoto Fine-Techno Co., Ltd.

The acidic dispersant (C) is preferably a dispersant of the following type (C1) or (C2). (C1) An acidic dispersant which is a reaction product between a hydroxyl group of a polymer having a hydroxyl group and an acid anhydride group of a tricarboxylic acid anhydride and/or a tetracarboxylic acid dianhydride. (C2) An acidic dispersant which is a polymer obtained by polymerizing an ethylenically unsaturated monomer in the presence of a reaction product between a hydroxyl group of a compound having a hydroxyl group and an acid anhydride group of a tricarboxylic acid anhydride and/or a tetracarboxylic acid dianhydride.

The acidic dispersant (C1) can be synthesized by known methods such as those described in WO2008/007776, JP2008-029901A, and JP2009-155406A.
First, the polymer (p) having a hydroxyl group, which is a precursor of the acidic dispersant (C1), is preferably a polymer having a hydroxyl group at the end. The polymer (p) having a hydroxyl group can be synthesized, for example, as a polymer obtained by polymerizing a monomer (r) in the presence of a compound (q) having a hydroxyl group. The compound (q) having a hydroxyl group is preferably a compound having a hydroxyl group and a thiol group in the molecule, more preferably a compound having two or more hydroxyl groups at the end, and even more preferably a compound (q1) having two hydroxyl groups and one thiol group in the molecule.
The hydroxyl groups of the polymer (p) having hydroxyl groups react with the acid anhydride groups of the tricarboxylic acid anhydride and/or tetracarboxylic acid dianhydride to form ester bonds, while the anhydride ring opens to generate a carboxylic acid.

A preferred synthesis method for the acidic dispersant (C1) is, for example, to obtain a polymer (p1) by polymerizing a monomer (r) in the presence of a compound (q1) having two hydroxyl groups and one thiol group in the molecule, and then reacting the hydroxyl groups of the polymer (p1) with the acid anhydride groups of a tricarboxylic acid anhydride and/or a tetracarboxylic acid dianhydride.

The compound (q) having an acid group includes at least a compound having a hydroxyl group and a thiol group in the molecule, and the compound having a hydroxyl group and a thiol group in the molecule is not limited as long as it has a hydroxyl group and a thiol group. Examples of such compounds include, in addition to the compounds having two hydroxyl groups and one thiol group in the molecule described below, compounds having one hydroxyl group and one thiol group in the molecule such as mercaptoethanol; compounds having one hydroxyl group and two thiol groups in the molecule such as 1,2-dimercapto-3-propanol and 1,3-dimercapto-2-propanol; compounds having one hydroxyl group and three or more thiol groups in the molecule such as pentaerythritol tris(3-mercaptoacetate) and dipentaerythritol pentakis(3-mercaptopropionate);
Compounds having two hydroxyl groups and two thiol groups in the molecule, such as 1,2-dimercapto-1,2-ethanediol; compounds having three or more hydroxyl groups and two thiol groups in the molecule, such as dimercaptodipentaerythritol; compounds having two or more hydroxyl groups and three or more thiol groups in the molecule, such as trimercaptodipentaerythritol; compounds having three or more hydroxyl groups and one thiol group in the molecule, such as 1-mercapto-1,2,2'-ethanetriol; and the like.

Examples of compounds (q1) having two hydroxyl groups and one thiol group in the molecule include 1-mercapto-1,1-methanediol, 1-mercapto-1,1-ethanediol, 3-mercapto-1,2-propanediol, 2-mercapto-1,2-propanediol, 2-mercapto-2-methyl-1,3-propanediol, 2-mercapto-2-ethyl-1,3-propanediol, 1-mercapto-2,2propanediol, 2-mercaptoethyl-2-methyl-1,3propanediol, and 2-mercaptoethyl-2-ethyl-1,3-propanediol.

The monomer (r) is not particularly limited as long as it is a copolymerizable monomer, and can be appropriately selected depending on the application.

Examples of the monomer (r) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth), tertiary butyl (meth)acrylate, isoamyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cetyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, isomyrris (meth)acrylate, and the like. linear or branched alkyl (meth)acrylates such as butyl (meth)acrylate, stearyl (meth)acrylate, and isostearyl (meth)acrylate; cyclic alkyl (meth)acrylates such as cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and isobornyl (meth)acrylate; (meth)acrylates having a heterocycle such as tetrahydrofurfuryl (meth)acrylate and 3-methyl-3-oxetanyl (meth)acrylate;
(Meth)acrylates having an aromatic ring, such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate; (meth)acrylates having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxypropyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 5-hydroxy-3-methylpentyl (meth)acrylate, neopentyl glycol mono(meth)acrylate, and cyclohexanediol mono(meth)acrylate;
(poly)alkylene glycol monoalkyl ether (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxypropyl (meth)acrylate, diethylene glycol monomethyl ether (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, diethylene glycol mono-2-ethylhexyl ether (meth)acrylate, dipropylene glycol monomethyl ether (meth)acrylate, triethylene glycol monomethyl ether (meth)acrylate, triethylene glycol monoethyl ether (meth)acrylate, tripropylene glycol monomethyl ether (meth)acrylate, tetraethylene glycol monomethyl ether (meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, polypropylene glycol monomethyl ether (meth)acrylate, polyethylene glycol monolauryl ether (meth)acrylate, polyethylene glycol monostearyl ether (meth)acrylate, and octoxypolyethylene glycol-polypropylene glycol (meth)acrylate;
those having an aromatic ring, such as phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, phenoxyhexaethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, paracumylphenoxyethyl (meth)acrylate, paracumylphenoxyethylene glycol (meth)acrylate, paracumylphenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolypropylene glycol (meth)acrylate, and nonylphenoxypoly(ethylene glycol-propylene glycol) (meth)acrylate; (Poly)alkylene glycol (meth)acrylates; (meth)acrylates having an alkyloxysilyl group, such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; fluoroalkyl (meth)acrylates, such as trifluoroethyl (meth)acrylate, octafluoropentyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, and tetrafluoropropyl (meth)acrylate; (meth)acryloxy-modified polydimethylsiloxane (silicone macromer); and the like.

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 vinyl acetate, vinyl propionate, and other vinyl fatty acids.

Examples of carboxyl group-containing monomers include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, and crotonic acid.

Examples of tricarboxylic acid anhydrides include aliphatic tricarboxylic acid anhydrides such as 3-carboxymethylglutaric anhydride, 1,2,4-butanetricarboxylic acid-1,2-anhydride, cis-propene-1,2,3-tricarboxylic acid-1,2-anhydride, and 1,3,4-cyclopentanetricarboxylic acid anhydride;
Examples of the aromatic tricarboxylic anhydrides include benzenetricarboxylic anhydrides (1,2,3-benzenetricarboxylic anhydride, trimellitic anhydride [1,2,4-benzenetricarboxylic anhydride], etc.), naphthalenetricarboxylic anhydrides (1,2,4-naphthalenetricarboxylic anhydride, 1,4,5-naphthalenetricarboxylic anhydride, 2,3,6-naphthalenetricarboxylic anhydride, 1,2,8-naphthalenetricarboxylic anhydride, etc.), 3,4,4'-benzophenonetricarboxylic anhydride, 3,4,4'-biphenylethertricarboxylic anhydride, 3,4,4'-biphenyltricarboxylic anhydride, 2,3,2'-biphenyltricarboxylic anhydride, 3,4,4'-biphenylmethanetricarboxylic anhydride, and 3,4,4'-biphenylsulfonetricarboxylic anhydride. Among these, aromatic tricarboxylic anhydrides are preferred from the viewpoint of adsorption to pigments.

Examples of tetracarboxylic dianhydrides include 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofural)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and bicyclo[2,2,2]-o aliphatic tetracarboxylic dianhydrides such as 2,3,5,6-hexyl-7-ene-tetracarboxylic dianhydride; pyromellitic anhydride, ethylene glycol ditrimellitic anhydride, propylene glycol ditrimellitic anhydride, butylene glycol ditrimellitic anhydride, 3,3',4,4'-benzophenone tetracarboxylic anhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic anhydride, 1,4,5,8-naphthalene tetracarboxylic anhydride, 2,3,6,7-naphthalene tetracarboxylic anhydride, 3,3',4,4'-biphenyl ether tetracarboxylic anhydride, 3,3',4,4'-dimethyldi ... phenylsilane tetracarboxylic anhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic anhydride, 1,2,3,4-furan tetracarboxylic anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfone anhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane anhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic anhydride, 3,3',4,4'-biphenyl tetracarboxylic anhydride, bis(phthalic acid)phenylphosphine oxide anhydride, p-phenylene-bis(triphenyl m-phenylene-bis(triphenylphthalic) anhydride, bis(triphenylphthalic)-4,4'-diphenyl ether anhydride, bis(triphenylphthalic)-4,4'-diphenylmethane anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene anhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-6-methyl-1-naphthalene succinic anhydride, and other aromatic tetracarboxylic acid anhydrides are included. Among these, aromatic tetracarboxylic acid dianhydrides are preferred from the viewpoint of adsorption to pigments.

The tricarboxylic acids and tetracarboxylic anhydrides used in the present invention are not limited to the compounds exemplified above, and may have any structure as long as they contain a carboxyl group. These may be used alone or in combination. Compounds having one carboxylic anhydride group in the molecule or compounds having three or more carboxylic anhydride groups may be used in combination. It is preferable that the tricarboxylic acids and tetracarboxylic anhydrides contain aromatic carboxyl groups. When a dispersant containing an aromatic carboxyl group is used, the pigment has high adsorption properties, and thus the prevention of reagglomeration of the pigment after dispersion is particularly improved. An aromatic carboxyl group is a group in which a carboxyl group is directly bonded to an aromatic ring.

[Acidic Dispersant (C2)]
The acidic dispersant (C2) can be synthesized by known methods such as those described in WO2008/007776, JP2009-155406A, JP2010-185934A, and JP2011-157416A. The acidic dispersant (C2) can be obtained, for example, by polymerizing a monomer (r) in the presence of a reaction product between a hydroxyl group of a compound (q) having a hydroxyl group and an acid anhydride group of a tricarboxylic acid anhydride and/or a tetracarboxylic acid dianhydride. Among them, a polymer obtained by polymerizing a monomer (r) in the presence of a reaction product between a hydroxyl group of a compound (q1) having two hydroxyl groups and one thiol group in the molecule and an acid anhydride group of a tricarboxylic acid anhydride and/or a tetracarboxylic acid dianhydride is preferred.

The difference between acidic dispersant (C1) and acidic dispersant (C2) is whether the polymer moiety formed by polymerizing monomer (r) is introduced first or later. The molecular weight and other factors may differ slightly depending on various conditions, but in theory, the same product can be produced if the raw materials and reaction conditions are the same.

The amount of acidic dispersant (C) used is preferably about 5 to 200 parts by mass, and more preferably 5 to 100 parts by mass, per 100 parts by mass of pigment (A). Using an appropriate amount improves film-forming properties.

The number average molecular weight of the acidic dispersant (C) is preferably 1,000 to 5,0000, and more preferably 3,000 to 2,0000. The weight average molecular weight is a value measured by gel permeation chromatography (GPC).

In this specification, it is preferable that the mass ratio of the pigment (A), the basic dispersant (B), and the acidic dispersant (C) satisfies A/(A+B+C)>0.5. By using the characteristic basic dispersant and acidic dispersant in combination in this specification, good storage stability and developability can be obtained even when a large amount of pigment is contained.

<Production of Pigment Composition>
The pigment composition is prepared by dispersing the pigment (A), a basic dispersant (B), an acidic dispersant (C), a solvent, etc. to prepare a pigment (A) dispersion. When a dispersing aid such as a dye derivative is used in the dispersion, the pigment (A) can be dispersed more finely. In addition, when the pigment (A) has high solubility in the solvent, the dispersion may not require the dispersion. When two or more types of pigment (A) are used in combination, the pigment (A) dispersion may use a separate pigment (A) or a plurality of pigments (A) in combination. The timing of mixing each material is arbitrary.

The dispersion process can be carried out using a dispersion device such as a kneader, a two-roll mill, a three-roll mill, a ball mill, a horizontal sand mill, a vertical sand mill, an annular bead mill, or an attritor.

The photosensitive pigment composition of the present specification preferably contains the above-mentioned pigment composition, a photopolymerizable monomer, and a photopolymerization initiator. The photosensitive pigment composition is preferably used for producing a color filter.

<Photopolymerizable Monomer>
The photosensitive pigment composition may contain a photopolymerizable monomer. The photopolymerizable monomer includes a monomer or oligomer that is cured by exposure to ultraviolet light, heat, or the like to form a transparent resin.

Examples of photopolymerizable monomers include methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, β-carboxyethyl (meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 1,6-hexanediol diglycidyl ether di(meth)acrylate, and bisphenol A diglycidyl ether. Examples of such acrylic acid esters and methacrylic acid esters include di(meth)acrylate, neopentyl glycol diglycidyl ether di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tricyclodecanyl (meth)acrylate, ester acrylate, (meth)acrylic acid ester of methylol melamine, epoxy (meth)acrylate, and urethane acrylate, as well as (meth)acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-vinyl formamide, and acrylonitrile.

The photopolymerizable monomers can be used alone or in combination of two or more types.

The content of the photopolymerizable monomer is preferably 5 to 500 parts by mass, and more preferably 10 to 400 parts by mass, per 100 parts by mass of pigment (A). When an appropriate amount is contained, the photocurability and developability are improved.

<Photopolymerization initiator>
The photosensitive pigment composition can contain a photopolymerization initiator.
Examples of the photopolymerization initiator include acetophenone-based compounds such as 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one; benzoin, benzoin methyl ether, benzoin ethyl ether, and the like. benzoin compounds such as benzoyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal; benzophenone compounds such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and 2,4-diethylthioxanthone; 2,4,6-trichloro-s-triazanthine 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-piperonyl-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxy-naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl-(piperonyl)-6-triazine, or 2,4-trichloromethyl-(4'-methoxystyryl)-s-triazine. triazine-based compounds such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], or O-(acetyl)-N-(1-phenyl-2-oxo-2-(4'-methoxy-naphthyl)ethylidene)hydroxylamine; phosphine-based compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide or 2,4,6-trimethylbenzoyldiphenylphosphine oxide; quinone-based compounds such as 9,10-phenanthrenequinone, camphorquinone, or ethylanthraquinone; borate-based compounds; carbazole-based compounds; imidazole-based compounds; and titanocene-based compounds.

Photopolymerization initiators can be used alone or in combination of two or more types.

The content of the photopolymerization initiator is preferably 1 to 500 parts by mass, and more preferably 5 to 400 parts by mass, per 100 parts by mass of pigment (A). When an appropriate amount is contained, photocurability and developability are improved.

In addition to the above, the photosensitive pigment composition may contain additives such as a leveling agent, a storage stabilizer, and an adhesion improver.

<Color filter>
The color filter of the present specification includes a base material (also referred to as a substrate or transparent substrate) and a filter segment formed from a photosensitive pigment composition. The filter segment preferably has a red filter segment, a green filter segment, and a blue filter segment by appropriately selecting the type of pigment (A) used. In addition, the filter segment can further have a magenta filter segment, a cyan filter segment, and a yellow filter segment. In addition, a reflective substrate can be used instead of the transparent substrate. Examples of the transparent substrate include glass substrates such as soda-lime glass, low-alkali borosilicate glass, and non-alkali aluminoborosilicate glass, and resin substrates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate. In addition, a transparent electrode made of indium oxide, tin oxide, etc. may be formed on the surface of the transparent substrate for driving the liquid crystal after panelization.
The reflective substrate may be, for example, a substrate using an aluminum electrode or a metal thin film as a reflective surface. In the color filter of the present specification, at least one of a plurality of color filter segments is produced using the pigment composition of the present specification.

<Manufacturing method of color filter>
It is preferable that the color filter is formed by first forming a black matrix on a substrate and then forming filter segments. It is also possible to form thin film transistors (TFTs) on the substrate before forming the black matrix.
Examples of the black matrix include a multilayer film of chromium or chromium/chromium oxide, an inorganic film such as titanium nitride, and a resin film in which a light-shielding agent is dispersed.

The filter segments can be formed by, for example, a printing method, an electrodeposition method, a transfer method, an inkjet method, a photolithography method, etc. Below, the photolithography method is explained. The photolithography method is preferable because it can produce color filters with higher precision than the printing method.

In the photolithography method, for example, a photosensitive coloring composition containing a colorant of a certain color tone is applied to a transparent substrate so that the dry film thickness is about 0.2 to 5 μm to form a coating. The obtained coating (hereinafter referred to as the first coating) is exposed (irradiated with light) through a mask having a predetermined pattern. Next, the coating is developed by immersing in a solvent or an alkaline developer or spraying the developer with a spray or the like, and the uncured parts are removed to obtain the desired pattern. By carrying out this process in the same manner using a photosensitive coloring composition containing a colorant of another color tone, a color filter having filter segments of each color can be manufactured. In addition, a second coating (oxygen barrier film) can be formed on the first coating before exposure using polyvinyl alcohol or a water-soluble acrylic resin. This prevents the first coating from coming into contact with oxygen, thereby further improving the exposure sensitivity. In addition, the color filter can be heated to cure the uncured photopolymerizable compound in the filter segment.

Examples of coating devices include spray coaters, spin coaters, slit coaters, and roll coaters. A drying process can be carried out during coating. Examples of drying devices include hot air ovens and infrared heaters.

The developer may be an alkaline developer, such as an inorganic alkali such as sodium carbonate or sodium hydroxide; or an organic alkali such as dimethylbenzylamine or triethanolamine. A defoamer or surfactant may also be added to the developer.

In this specification, after forming the color filter segment, the color filter is laminated to the opposing substrate using a sealant, liquid crystal is injected through an injection port provided in the sealing portion, the injection port is sealed, and a polarizing film or a retardation film is laminated to the outside of the substrate as necessary, thereby producing a liquid crystal display device. Examples of liquid crystal display devices include twisted nematic (TN), super twisted nematic (STN), in-plane switching (IPS), vertical alignment (VA), and optically concave bend (OCB).

The display device in this specification is equipped with a color filter. The display device is not limited to the above-mentioned liquid crystal display device, organic EL display device, solid-state imaging device, etc., as long as it is equipped with a color filter.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Note that "parts" means "parts by mass" and "%" means "% by mass." The amounts in the tables are in parts by mass unless otherwise specified.

The measurement methods used in the examples are described below.

(Molecular Weight of Basic Dispersant (B))
The number average molecular weight (Mn) and weight average molecular weight (Mw) of the basic dispersant (B) were measured by the following method. The molecular weight was measured in terms of polystyrene using a GPC (HLC-8320GPC, Tosoh Corporation) equipped with an RI detector and two TSKgelSUPER-AW3000 (Tosoh Corporation) columns in series, and a solution of 3 mM triethylamine and 10 mM LiBr in N,N-dimethylformamide as the developing solvent. The mobile phase flow rate was 0.6 mL/min, the sample injection amount was 10 μL, the sample concentration was about 0.1% by mass, and the measurement temperature was 40° C.

(Amine value of pigment dispersant)
The amine value (mg KOH/g) was determined by potentiometric titration using a 0.1 N aqueous hydrochloric acid solution, and then converted into an equivalent amount of potassium hydroxide.

(Molecular Weight of Acidic Dispersant (C))
The number average molecular weight (Mn) and weight average molecular weight (Mw) of the acidic dispersant (C) were measured by the following method. The molecular weight was measured in terms of polystyrene using two TSK-GEL SUPER HZM-N (manufactured by Tosoh Corporation) columns in series, a GPC (manufactured by Tosoh Corporation, HLC-8320GPC) equipped with an RI detector, and a tetrahydrofuran (THF) solution as the developing solvent. The mobile phase flow rate was 0.35 ml/min, the sample injection amount was 10 μL, the sample concentration was about 0.1% by mass, and the measurement temperature was 40° C.

(Acid value)
The acid value (mgKOH/g) of the acidic dispersant (C) and the binder resin was determined by potentiometric titration using a 0.1 N potassium hydroxide-ethanol solution.

<Production of Basic Dispersant (B)>
(Synthesis Example 1: Synthesis of Basic Dispersant B-1)
In a reaction vessel equipped with a gas inlet tube, a condenser, an agitator, and a thermometer, 80 parts of butyl methacrylate, 2.1 parts of methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate as RAFT agent 1, and 82 parts of propylene glycol monomethyl ether acetate were charged, and the mixture was heated to 90°C with stirring while flowing nitrogen. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of block B. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more, calculated from the nonvolatile content, and the polymerization of block B was completed.
Next, 20 parts of 2-isocyanatoethyl methacrylate and 20 parts of propylene glycol monomethyl ether acetate were charged into the reaction vessel, and the mixture was stirred while maintaining a nitrogen atmosphere at 90°C. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of the A block precursor. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the A block precursor was completed. The reaction vessel was then cooled to room temperature, and a mixed solution of 14 parts of 3-(aminomethyl)pyridine and 72 parts of propylene glycol monomethyl ether acetate was dripped over 1 hour to react with the isocyanate group of the A block precursor to produce an A block containing a unit having a nitrogen-containing heterocyclic group having aromatic properties . In this way, a solution of a basic dispersant (B-1) which is an AB block polymer having a nonvolatile content of 40%, an amine value of 63 mgkOH/g, a weight average molecular weight of 22,000 and a molecular weight distribution of 1.3 was obtained.

(Synthesis Examples 2 to 17, 21: Synthesis of Basic Dispersants B-2 to 17, 21)
Except for changing the composition of Synthesis Example 1 to the raw materials and the amounts of the raw materials shown in Tables 1 and 2-1, the reaction was carried out in the same manner as in Synthesis Example 1 to prepare solutions of A-B block polymers (basic dispersants B-2 to B-17, 21). The weight average molecular weight of the basic dispersant was adjusted to the weight average molecular weight in the table by appropriately adding and changing the chain transfer agent, reaction conditions, etc.

(Synthesis Example 18: Synthesis of Basic Dispersant B-18)
In a reaction vessel equipped with a gas inlet tube, a condenser, an agitator, and a thermometer, 80 parts of butyl methacrylate, 2.1 parts of methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate as RAFT agent 1, and 82 parts of propylene glycol monomethyl ether acetate were charged, and the mixture was heated to 90°C with stirring while flowing nitrogen. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of B block. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more, calculated from the nonvolatile content, and the polymerization of B block was completed.
Next, 20 parts of glycidyl methacrylate and 20 parts of propylene glycol monomethyl ether acetate were charged into the reaction tank and stirred while maintaining a nitrogen atmosphere at 90°C, and 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of the A block precursor. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then after another hour, a sample of the polymerization solution was taken and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the A block precursor was completed.
Further, 14 parts of 3-(aminomethyl)pyridine and 72 parts of propylene glycol monomethyl ether acetate were charged into the reaction tank and stirred at 80° C. for 3 hours to react the amine with the glycidyl group of the A block precursor. In this manner, a basic dispersant (B-18) solution was obtained, which was an A-B block polymer with a nonvolatile content of 40%, an amine value of 63 mg KOH/g, a weight average molecular weight of 24,000, and a molecular weight distribution of 1.4.

(Synthesis Example 19: Synthesis of Basic Dispersant B-19)
In a four-necked separable flask equipped with a thermometer, a stirrer, a dropping funnel, and a cooler, 83 parts of propylene glycol monomethyl ether acetate, 1.4 parts of bis(dodecylsulfanylthiocarbonyl) disulfide of RAFT2, and 0.6 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) were charged, and the temperature was raised to 80°C under a nitrogen stream, and the reaction was allowed to proceed for 2 hours. 80 parts of n-butyl methacrylate were charged therein, and the temperature was raised to 90°C under a nitrogen stream. 0.08 parts of 2,2'-azobis(isobutyronitrile) were charged therein, and the synthesis of the B block was initiated. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and the polymerization solution was sampled and the nonvolatile content was measured after another hour. It was confirmed that the polymerization conversion rate was 80% or more calculated from the non-volatile content, and the polymerization of the B block precursor was completed.
Thereafter, 20 parts of 2-isocyanatoethyl methacrylate, 19 parts of propylene glycol monomethyl ether acetate, and 0.08 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) were charged to initiate polymerization of the A block precursor. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the A block precursor was completed. Furthermore, the reaction tank was cooled to 5°C, and a mixed solution of 14 parts of 3-(aminomethyl)pyridine and 72 parts of propylene glycol monomethyl ether acetate was dropped over 1 hour to react with the isocyanate group of the A block precursor to produce an A block containing a unit having a nitrogen-containing heterocyclic group having aromatic properties . In this way, a solution of a basic dispersant (B-19) which is an AB block polymer having a nonvolatile content of 40%, an amine value of 63 mgkOH/g, a weight average molecular weight of 19,500 and a molecular weight distribution of 1.3 was obtained.

(Synthesis Example 20: Synthesis of Basic Dispersant B-20)
In a reaction vessel equipped with a gas inlet tube, a condenser, an agitator, and a thermometer, 40 parts of butyl methacrylate, 2.1 parts of methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate as RAFT agent 1, and 42 parts of propylene glycol monomethyl ether acetate were charged, and the mixture was heated to 90°C with stirring while flowing nitrogen. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of B block. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more, calculated from the nonvolatile content, and the polymerization of B block was completed.
Next, 20 parts of 2-isocyanatoethyl methacrylate and 20 parts of propylene glycol monomethyl ether acetate were charged into the reaction tank and stirred while maintaining a nitrogen atmosphere at 90°C, and 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of the A block precursor. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and the reaction was continued for another hour. The polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the A block precursor was completed.
Subsequently, 40 parts of butyl methacrylate and 40 parts of propylene glycol monomethyl ether acetate were charged into the reaction tank and stirred while maintaining a nitrogen atmosphere at 90° C., and 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization. Five hours and six hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and the polymerization solution was sampled and the nonvolatile content was measured after a further hour. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the B block was completed.
The reaction vessel was then cooled to room temperature, and a mixed solution of 14 parts of 3-(aminomethyl)pyridine and 72 parts of propylene glycol monomethyl ether acetate was added dropwise over one hour to react with the isocyanate group of the A block precursor to produce an A block containing a unit having a nitrogen-containing heterocyclic group with aromatic properties . In this way, a basic dispersant (B-20) solution was obtained with a nonvolatile content of 40%, an amine value of 63 mgKOH/g, a weight average molecular weight of 23,000, and a molecular weight distribution of 1.4.

(Synthesis Example 22: Synthesis of Basic Dispersant B-22)
In a reaction vessel equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer, 80 parts of butyl methacrylate, 20 parts of 2-isocyanatoethyl methacrylate, 2.1 parts of methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate as RAFT agent 1, and 82 parts of propylene glycol monomethyl ether acetate were charged, and the mixture was heated and stirred to 90°C while flowing nitrogen. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged here to initiate polymerization of the B block. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the precursor of the random polymer B-22 was completed.
The reaction vessel was then cooled to room temperature, and a mixed solution of 14 parts of 3-(aminomethyl)pyridine and 72 parts of propylene glycol monomethyl ether acetate was added dropwise over one hour to react with the isocyanate group of the A block precursor to produce an A block containing a unit having a nitrogen-containing heterocyclic group with aromatic properties . In this way, a basic dispersant (B-22) solution was obtained with a nonvolatile content of 40%, an amine value of 63 mgKOH/g, a weight average molecular weight of 22,000, and a molecular weight distribution of 1.3.

(Synthesis of B-101)
It was synthesized according to Synthesis Example 1 of WO2010/016523. An A-B block polymer having a glycidyl group reacted with di-n-butylamine in the B block was diluted with propylene glycol monomethyl ether acetate to obtain a solution of a basic dispersant (B-101) having a nonvolatile content of 40%, an amine value of 61 mgKOH/g, a weight average molecular weight of 20,000, and a molecular weight distribution of 1.3.

(Synthesis of Monomer (a))
A reaction vessel equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer was charged with 50 parts of ethyl acetate and 20.5 parts of 3-(aminomethyl)pyridine, and stirred at room temperature while flowing nitrogen. 29.5 parts of 2-isocyanatoethyl methacrylate was added dropwise thereto over 1 hour to react the isocyanate group with the amino group. The precipitated solid was collected by suction filtration, and identified by ¹ H-NMR to confirm that it was the target product. The solvent was removed by drying under reduced pressure to obtain monomer (a) which is " a reaction product of a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group."

(Synthesis Example 23: Synthesis of Basic Dispersant B-23)
In a reaction vessel equipped with a gas inlet tube, a condenser, an agitator, and a thermometer, 80 parts of butyl methacrylate, 2.1 parts of methyl 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoate as RAFT agent 1, and 82 parts of propylene glycol monomethyl ether were charged, and the mixture was heated to 90°C with stirring while flowing nitrogen. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of B block. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more, calculated from the nonvolatile content, and the polymerization of B block was completed.
Next, 34 parts of the monomer (a) and 92 parts of propylene glycol monomethyl ether prepared above were charged into the reaction tank, and the mixture was stirred while maintaining a nitrogen atmosphere at 90°C. 0.08 parts of 2,2'-azobis(isobutyronitrile) was charged to initiate polymerization of the A block precursor. 5 hours and 6 hours after the start of polymerization, 0.01 parts of 2,2'-azobis(isobutyronitrile) were charged, and then 1 hour later, the polymerization solution was sampled and the nonvolatile content was measured. It was confirmed that the polymerization conversion rate was 80% or more based on the nonvolatile content, and the polymerization of the A block precursor was completed. In this way, a basic dispersant (B-23) solution was obtained, which is an A-B block polymer with a nonvolatile content of 40%, an amine value of 63 mgKOH/g, a weight average molecular weight of 22,500, and a molecular weight distribution of 1.3.

(Synthesis Examples 24 to 26: Synthesis of Basic Dispersants B-24 to B-26)
Except for changing the composition of Synthesis Example 23 to the raw materials and the amounts thereof shown in Table 2-2, the reaction was carried out in the same manner as in Synthesis Example 23 to prepare solutions of AB block polymers (basic dispersants B-24 to B-26).

The abbreviations in Tables 1 to 2-2 are as follows:
BMA: n-butyl methacrylate MMA: methyl methacrylate EA: ethyl acrylate 2-MTA: 2-methoxyethyl acrylate OXMA: (3-ethyloxetan-3-yl)methyl methacrylate tBMA: tert-butyl methacrylate MOI: 2-isocyanatoethyl methacrylate AOI: 2-isocyanatoethyl acrylate MOI-EG: 2-(2-isocyanatoethoxy)ethyl methacrylate GMA: glycidyl methacrylate RAFT agent 1: 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]methyl pentanoate RAFT agent 2: bis(dodecylsulfanylthiocarbonyl)disulfide AIBN: 2,2'-azobis(isobutyronitrile)
V65: 2,2'-azobis(2,4-dimethylvaleronitrile)
PGMAc: propylene glycol monomethyl ether acetate MAA: methacrylic acid HEMA: 2-hydroxyethyl methacrylate PGME: propylene glycol monomethyl ether

<Production of Acidic Dispersant (C)>
(Preparation of Acidic Dispersant (C-1) Solution)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer was charged with 10 parts of methacrylic acid, 100 parts of methyl methacrylate, 70 parts of iso-butyl methacrylate, and 20 parts of benzyl methacrylate, and substituted with nitrogen gas. The reaction vessel was heated to 80°C, and a solution of 0.1 parts of 2,2'-azobisisobutyronitrile dissolved in 10 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. It was confirmed that 95% had reacted by measuring the non-volatile content. 20 parts of pyromellitic anhydride, 200.0 parts of propylene glycol monomethyl ether acetate, and 0.40 parts of 1,8-diazabicyclo-[5.4.0]-7-undecene as a catalyst were added, and the reaction was carried out at 120°C for 7 hours. The reaction was terminated after confirming by measuring the acid value that 98% or more of the acid anhydride had been half-esterified, yielding a dispersant with an acid value of 77 mgKOH/g and a number average molecular weight (Mn) of 8500. Propylene glycol monomethyl ether acetate was added thereto so that the nonvolatile content was 40% by measuring the nonvolatile content, thereby obtaining a solution of an acidic dispersant (C-1) having an aromatic carboxyl group.

(Preparation of Acid Dispersant (C-2) Solution)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer was charged with 10 parts of methacrylic acid, 100 parts of methyl methacrylate, 70 parts of iso-butyl methacrylate, and 20 parts of benzyl methacrylate, and substituted with nitrogen gas. The reaction vessel was heated to 80°C, and a solution of 0.1 parts of 2,2'-azobisisobutyronitrile dissolved in 10 parts of 3-mercapto-1,2-propanediol was added and reacted for 10 hours. It was confirmed that 95% had reacted by measuring the non-volatile content. 36 parts of trimellitic anhydride, 200.0 parts of propylene glycol monomethyl ether acetate, and 0.40 parts of 1,8-diazabicyclo-[5.4.0]-7-undecene as a catalyst were added, and the reaction was carried out at 120°C for 7 hours. The reaction was terminated after confirming by measuring the acid value that 98% or more of the acid anhydride had been half-esterified, yielding a dispersant with an acid value of 109 mgKOH/g and a number average molecular weight (Mn) of 8500. Propylene glycol monomethyl ether acetate was added thereto so that the nonvolatile content was 40% by measuring the nonvolatile content, thereby obtaining a solution of an acidic dispersant (C-2) having an aromatic carboxyl group.

(Preparation of Acid Dispersant (C-3) Solution)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer was charged with 6.5 parts of 3-mercapto-1,2-propanediol, 4.0 parts of pyromellitic anhydride, 0.01 parts of dimethylbenzylamine, and 41.8 parts of propylene glycol monomethyl ether acetate, and substituted with nitrogen gas. The reaction vessel was heated to 100 ° C. and reacted for 7 hours. After confirming that 98% or more of the acid anhydride was half-esterified by measuring the acid value, the temperature of the reaction liquid was cooled to 70 ° C., 67 parts of methyl methacrylate, 5.0 parts of methacrylic acid, 16.0 parts of tert-butyl acrylate, 10.0 parts of hydroxymethyl methacrylate, and 2.0 parts of ethyl acrylate were charged, and 0.10 parts of 2,2'-azobisisobutyronitrile and 60.0 parts of propylene glycol monomethyl ether acetate were added, and the reaction was carried out for 10 hours. The reaction was terminated after confirming that the polymerization had progressed to 95% by non-volatile content measurement, to obtain a dispersant having an acid value of 43 mgKOH/g and a number average molecular weight (Mn) of 15000. Propylene glycol monomethyl ether acetate was added thereto so that the non-volatile content reached 40% by non-volatile content measurement, to obtain a solution of an acidic dispersant (C-3) having an aromatic carboxyl group.

(Preparation of Acid Dispersant (C-4) Solution)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer was charged with 6.5 parts of 3-mercapto-1,2-propanediol, 4.0 parts of pyromellitic anhydride, 0.01 parts of dimethylbenzylamine, and 41.8 parts of propylene glycol monomethyl ether acetate, and substituted with nitrogen gas. The reaction vessel was heated to 100 ° C. and reacted for 7 hours. After confirming that 98% or more of the acid anhydride was half-esterified by measuring the acid value, the temperature of the reaction liquid was cooled to 70 ° C., 67 parts of methyl methacrylate, 5.0 parts of methacrylic acid, 16.0 parts of t-butyl acrylate, 10.0 parts of (3-ethyloxetan-3-yl)methyl methacrylate, and 2.0 parts of ethyl acrylate were charged, and 0.10 parts of 2,2'-azobisisobutyronitrile and 60.0 parts of propylene glycol monomethyl ether acetate were added, and the reaction was carried out for 10 hours. The reaction was terminated after confirming that the polymerization had progressed to 95% by non-volatile content measurement, yielding a dispersant with an acid value of 47 mgKOH/g and a number average molecular weight (Mn) of 15000. Propylene glycol monomethyl ether acetate was added thereto so that the non-volatile content reached 40% by non-volatile content measurement, yielding a solution of an acidic dispersant (C-4) having an aromatic carboxyl group.

<Method of producing acrylic resin solution>
(Preparation of acrylic resin solution 1)
A separable 4-neck flask was fitted with a thermometer, a cooling tube, a nitrogen gas inlet tube, a dropping tube and a stirrer, and 196 parts of cyclohexanone was charged in the reaction vessel. The temperature was raised to 80°C, and the inside of the reaction vessel was replaced with nitrogen. From the dropping tube, a mixture of 37.2 parts of n-butyl methacrylate, 12.9 parts of 2-hydroxyethyl methacrylate, 12.0 parts of methacrylic acid, 20.7 parts of paracumylphenol ethylene oxide modified acrylate, and 1.1 parts of 2,2'-azobisisobutyronitrile was dropped over 2 hours. After the dropwise addition was completed, the reaction was continued for another 3 hours to obtain an acrylic resin solution. After cooling to room temperature, about 2 parts of the resin solution was sampled and dried by heating at 180°C for 20 minutes to measure the nonvolatile content, and methoxypropyl acetate was added to the resin solution synthesized earlier so that the nonvolatile content was 20% to produce acrylic resin solution 1. The weight average molecular weight (Mw) was 26,000.

(Preparation of acrylic resin solution 2)
A separable 4-neck flask was equipped with a thermometer, a cooling tube, a nitrogen gas inlet tube, a dropping tube and a stirrer, and 207 parts of cyclohexanone was charged in the reaction vessel. The temperature was raised to 80°C, and the inside of the reaction vessel was replaced with nitrogen. From the dropping tube, a mixture of 20 parts of methacrylic acid, 20 parts of paracumylphenol ethylene oxide modified acrylate), 45 parts of methyl methacrylate, 8.5 parts of 2-hydroxyethyl methacrylate, and 1.33 parts of 2,2'-azobisisobutyronitrile was dropped over 2 hours. After the dropwise addition was completed, the reaction was continued for another 3 hours to obtain a copolymer resin solution. Next, the nitrogen gas was stopped and dry air was injected for 1 hour with respect to the total amount of the obtained copolymer solution, and then the mixture was cooled to room temperature, and a mixture of 6.5 parts of 2-methacryloyloxyethyl isocyanate (Showa Denko KARENZ MOI), 0.08 parts of dibutyltin laurate, and 26 parts of cyclohexanone was dropped over 3 hours at 70°C. After the dropwise addition, the reaction was continued for another hour to obtain an acrylic resin solution. After cooling to room temperature, about 2 parts of the resin solution were sampled and dried by heating at 180°C for 20 minutes to measure the non-volatile content. Cyclohexanone was added to the previously synthesized resin solution so that the non-volatile content was 20%, and acrylic resin solution 2 was produced. The weight average molecular weight (Mw) was 18,000.

<Production of finely divided pigment>
(Production of Red Micronized Pigment RP-1)
100 parts of the pigment synthesized according to Example 4 of Japanese Patent No. 6368844, 1200 parts of sodium chloride, and 120 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.), kneaded for 6 hours at 60°C, and subjected to salt milling treatment. The kneaded product obtained was charged into 3 liters of warm water, heated to 70°C and stirred for 1 hour to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80°C for one day to obtain 98 parts of red fine pigment RP-1. The average primary particle size was 28 nm.

(Production of Red Micronized Pigment RP-2)
100 parts of the pigment synthesized according to Example 22 of Japanese Patent No. 6368844, 1200 parts of sodium chloride, and 120 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.), kneaded for 6 hours at 60°C, and subjected to salt milling treatment. The kneaded product obtained was charged into 3 liters of warm water, heated to 70°C and stirred for 1 hour to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80°C for one day to obtain 98 parts of red fine pigment RP-2. The average primary particle size was 30 nm.

(Production of Red Micronized Pigment RP-3)
100 parts of C.I. Pigment Red 269 (PR269) (Sanyo Pigment Co., Ltd. "Permanent Carmine 3810"), 1200 parts of sodium chloride, and 120 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (Inoue Manufacturing Co., Ltd.), kneaded at 60 ° C. for 6 hours, and salt milled. The kneaded product obtained was put into 3 liters of warm water, heated to 70 ° C. and stirred for 1 hour to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80 ° C. for 24 hours to obtain 98 parts of red fine pigment PR-3. The average primary particle size was 35 nm.

(Production of Red Micronized Pigment RP-4)
In a stainless steel reaction vessel equipped with a reflux condenser, 200 parts of tert-amyl alcohol dehydrated with a molecular sieve and 140 parts of sodium tert-amyl alkoxide were added under a nitrogen atmosphere, and the mixture was heated to 100°C while stirring to produce an alcoholate solution. Meanwhile, 88 parts of diisopropyl succinate and 153.6 parts of 4-bromobenzonitrile were added to a glass flask, and the mixture was dissolved by heating to 90°C while stirring to prepare a solution of the mixture. The heated solution of the mixture was slowly dropped at a constant rate over 2 hours into the alcoholate solution heated to 100°C while stirring vigorously. After the dropwise addition, heating and stirring were continued at 90°C for 2 hours to obtain an alkali metal salt of a diketopyrrolopyrrole compound. Furthermore, 600 parts of methanol, 600 parts of water, and 304 parts of acetic acid were added to a glass jacketed reaction vessel, and the mixture was cooled to -10°C. The cooled mixture was rotated at 4000 rpm using a high-speed stirring disperser with a shear disk having a diameter of 8 cm, and the previously obtained alkali metal salt solution of the diketopyrrolopyrrole compound cooled to 75 ° C. was added in small amounts to the mixture. At this time, the mixture was cooled so that the temperature of the mixture consisting of methanol, acetic acid, and water was always kept at a temperature of -5 ° C. or less, and the alkali metal salt of the diketopyrrolopyrrole compound at 75 ° C. was added in small amounts over about 120 minutes while being cooled and the rate of addition was adjusted. After the addition of the alkali metal salt, red crystals were precipitated and a red suspension was generated. The resulting red suspension was then washed with an ultrafiltration device at 5 ° C. and filtered to obtain a red paste. This paste was redispersed in 3500 parts of methanol cooled to 0 ° C. to obtain a suspension with a methanol concentration of about 90%, which was stirred at 5 ° C. for 3 hours, and particle sizing and washing accompanied by crystal transition were performed. The resulting aqueous paste of the diketopyrrolopyrrole compound was then filtered using an ultrafilter, and the resulting aqueous paste was dried at 80° C. for 24 hours and pulverized to obtain 150.8 parts of a brominated diketopyrrolopyrrole pigment represented by the chemical formula (1).

100 parts of the obtained brominated diketopyrrolopyrrole pigment represented by chemical formula (1), 1200 parts of sodium chloride, and 120 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.), kneaded at 60°C for 6 hours, and subjected to salt milling. The kneaded product obtained was poured into 3 liters of warm water, heated to 70°C and stirred for 1 hour to form a slurry, filtered and washed repeatedly with water to remove the sodium chloride and diethylene glycol, and then dried at 80°C for a day and night to obtain 98 parts of red fine pigment PR-4. The average primary particle size was 45 nm.

(Production of Red Micronized Pigment RP-5)
The same procedure as for the production of the red fine pigment RP-3 was carried out except that C.I. Pigment Red 269 (PR269) ("Permanent Carmine 3810" manufactured by Sanyo Pigment Co., Ltd.) was replaced with C.I. Pigment Red 254 (PR254) ("Irgazin Red D3656 HD" manufactured by BASF Japan Co., Ltd.), to obtain 97 parts of the red fine pigment RP-5. The average primary particle diameter was 33 nm.

(Production of Red Micronized Pigment RP-6)
The same procedure as for the production of the red fine pigment RP-3 was carried out except that C.I. Pigment Red 269 (PR269) (manufactured by Sanyo Pigment Co., Ltd., "Permanent Carmine 3810") was changed to C.I. Pigment Red 177 (PR177) (manufactured by Shinic Co., Ltd., "Sinilex Red SR3C"), to obtain 97 parts of the red fine pigment RP-6. The average primary particle diameter was 37 nm.

(Production of Red Micronized Pigment RP-7)
The same procedure as for the production of the red fine pigment RP-3 was carried out, except that C.I. Pigment Red 269 (PR269) ("Permanent Carmine 3810" manufactured by Sanyo Pigment Co., Ltd.) was replaced with C.I. Pigment Red 122 (PR122) ("Hostaperm Pink E" manufactured by Clariant), to obtain 97 parts of the red fine pigment RP-7. The average primary particle diameter was 41 nm.

(Production of Yellow Micronized Pigment YP-1)
Quinophthalone-based yellow pigment C.I. Pigment Yellow 138 (BASF Japan "Paliotol Yellow L0962-HD") 500 parts, sodium chloride 500 parts, and diethylene glycol 250 parts were charged into a stainless steel 1-gallon kneader (Inoue Seisakusho Co., Ltd.) and kneaded at 120 ° C. for 8 hours. Next, this kneaded product was put into 5 liters of warm water, heated to 70 ° C. and stirred for 1 hour to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80 ° C. for 24 hours to obtain 490 parts of yellow fine pigment YP-1. The average primary particle diameter was 63 nm.

(Production of Yellow Micronized Pigment YP-2)
500 parts of isoindoline-based yellow pigment C.I. Pigment Yellow 139 (BASF Japan "Paliotol Yellow L1820"), 500 parts of sodium chloride, and 250 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (Inoue Seisakusho Co., Ltd.) and kneaded at 120 ° C. for 8 hours. Next, this kneaded product was put into 5 liters of warm water, heated to 70 ° C. and stirred for 1 hour to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80 ° C. for 24 hours to obtain 510 parts of yellow fine pigment YP-2. The average primary particle size was 68 nm.

(Production of Green Micronized Pigment GP-1)
200 parts of a phthalocyanine green pigment C.I. Pigment Green 58 (DIC Corporation "FASTOGEN GREEN A110)), 1400 parts of sodium chloride, and 360 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (Inoue Seisakusho Co., Ltd.) and kneaded at 80°C for 6 hours. Next, this kneaded mixture was added to 8000 parts of warm water, heated to 80°C and stirred for 2 hours to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 85°C for a day and night to obtain 190 parts of a green fine pigment GP-1. The average primary particle diameter was 69 nm.

(Production of blue fine pigment BP-1)
Phthalocyanine blue pigment C.I. Pigment Blue 15:6 ("LIONOL BLUE ES" manufactured by Toyo Color Co., Ltd.) 200 parts, sodium chloride 1400 parts, and diethylene glycol 360 parts were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 80 ° C. for 6 hours. Next, this kneaded product was put into 8000 parts of warm water, heated to 80 ° C. and stirred for 2 hours to make a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 85 ° C. for a day and night to obtain 190 parts of blue fine pigment BP-1. The average primary particle size was 74 nm.

(Production of Purple Micronized Pigment VP-1)
Dioxazine-based purple pigment C.I. Pigment Violet 23 ("LIONOGEN VIOLET RL" manufactured by Toyo Color Co., Ltd.) 200 parts, sodium chloride 1400 parts, and diethylene glycol 360 parts were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) and kneaded at 80 ° C. for 6 hours. Next, this kneaded product was put into 8000 parts of warm water, heated to 80 ° C. and stirred for 2 hours to form a slurry, filtered and washed with water repeatedly to remove sodium chloride and diethylene glycol, and then dried at 85 ° C. for one day to obtain 190 parts of purple fine pigment VP-1. The average primary particle size was 69 nm.

<Method of producing pigment composition>
[Example 1]
(Preparation of Pigment Composition (M-1))
The following mixture was stirred and mixed to become uniform, and then dispersed for 3 hours in an Eiger mill ("Mini Model M-250 MKII" manufactured by Eiger Japan Co., Ltd.) using zirconia beads having a diameter of 0.5 mm. The mixture was then filtered through a filter having a pore size of 5.0 μm to prepare a pigment composition (M-1) having a non-volatile component content of 20% by mass.
Red fine pigment (RP-1): 11.0 parts Acrylic resin solution 1: 27.0 parts Propylene glycol monomethyl ether acetate (PGMAc): 53.0 parts Basic dispersant (B-1) solution: 4.5 parts Acidic dispersant (C-1) solution: 4.5 parts

[Examples 2 to 58, 201 to 208, Comparative Examples 1 to 2, 4]
(Pigment Compositions (M-2 to M-60, M-62, 201 to 208)
Thereafter, pigment compositions (M-2 to M-60, M-62, 201 to 208) were produced in the same manner as for pigment composition (M-1), except that the compositions were changed to those shown in Tables 3-1 and 3-2.

[Comparative Example 3]
(Preparation of pigment composition (M-61))
The following mixture was stirred and mixed to become uniform, and then dispersed for 3 hours in an Eiger mill ("Mini Model M-250 MKII" manufactured by Eiger Japan Co., Ltd.) using zirconia beads having a diameter of 0.5 mm. The mixture was then filtered through a filter having a pore size of 5.0 μm to prepare a pigment composition (M-61) having a non-volatile component content of 20% by mass.
Red fine pigment (RP-1): 11.0 parts Acrylic resin solution 1: 27.0 parts Propylene glycol monomethyl ether acetate (PGMAc): 53.0 parts Basic dispersant (B-1) solution: 9.0 parts

<Evaluation of Pigment Composition>
The heat resistance and storage stability of the resulting pigment composition and the coating film prepared using it were evaluated by the following methods, and the evaluation results are shown in Tables 3-1 and 3-2.

(Heat resistance)
The pigment composition was applied to a glass substrate measuring 100 mm long x 100 mm wide and 1.1 mm thick using a spin coater so that the dry thickness was 2.0 μm, and then dried at 70° C. for 20 minutes. The coating was then heated at 230° C. for 60 minutes to prepare a coating substrate. The chromaticity ([L*(1), a*(1), b*(1)]) of the obtained coating substrate under a C light source was measured using a microspectrophotometer (OSP-SP100 manufactured by Olympus Optical Co., Ltd.) before aging. The coating substrate was then heated at 250° C. for 1 hour, and the chromaticity ([L*(2), a*(2), b*(2)]) after a heat resistance test was measured under a C light source. Based on these values, the color difference ΔEab* was calculated using the following formula (1). The heat resistance of the coating was evaluated according to the following criteria.
Calculation formula (1) ΔEab*=√((L*(2)-L*(1))2+(a*(2)-a*(1))2+(b*(2)-b*
(1))2)
◎: ΔEab* is less than 1.0 (very good)
○: ΔEab* is 1.0 or more and less than 2.5 (good)
△: ΔEab* is 2.5 or more and less than 5.0 (poor)
×: ΔEab* is 5.0 or more (very poor)

(Storage stability)
The viscosity of the resulting pigment composition was measured at 25° C. and 20 rpm using an E-type viscometer (TUE-20L model, manufactured by Toki Sangyo Co., Ltd., cone rotor 1°34'×R24). The viscosity change rate (%) (= (viscosity after storage at 40° C. for 7 days−initial viscosity)/initial viscosity) was calculated from the initial viscosity on the day of preparation of the pigment composition and the viscosity measured after storage for 7 days in a thermostatic chamber at 40° C. The evaluation criteria for storage stability are as follows:
◎: Viscosity change rate is less than 10% (very good)
○: Viscosity change rate is 10% or more and less than 20% (good)
△: Viscosity change rate is 20% or more and less than 50% (bad)
×: Viscosity change rate is 50% or more (very poor)

The abbreviations in the table are as follows:
B-101: A basic dispersant solution having no aromatic nitrogen-containing heterocyclic group, prepared by diluting an A-B block polymer having a glycidyl group reacted with di-n-butylamine produced with reference to Synthesis Example 1 in WO2010/016523 with propylene glycol monomethyl ether acetate (PGMAc) to a non-volatile content of 40%. C-101: An acidic dispersant solution prepared by diluting Disperbyk-101 manufactured by BYK Japan with propylene glycol monomethyl ether acetate (PGMAc) to a non-volatile content of 40%.

The results in Tables 3-1 and 3-2 show that the pigment composition of the present invention provided good results in terms of heat resistance and storage stability of the coating film. In particular, when azo pigments such as RP-1 to RP-3 were used, particularly good results were obtained in terms of heat resistance and storage stability. It was also found that the pigment composition had excellent storage stability even in a composition with a relatively high pigment concentration, where the mass ratio of the pigment (A), basic dispersant (B), and acidic dispersant (C) in the pigment composition satisfies A/(A+B+C)>0.5.

<Preparation of Photosensitive Pigment Composition>
[Example 59]
(Photosensitive Pigment Composition (R-1))
The following mixture (total 100 parts) was stirred and mixed to a uniform state, and then filtered through a filter having a pore size of 1.0 μm to obtain a photosensitive pigment composition (R-1).
Pigment composition 1 (M-1): 24.0 parts Pigment composition 2 (M-50): 26.0 parts Acrylic resin solution 2: 7.5 parts Photopolymerizable monomer ("Aronix M-402" manufactured by Toagosei Co., Ltd., dipentaerythritol hexaacrylate): 2.0 parts Photopolymerization initiator ("OXE-02" manufactured by BASF Japan Ltd., ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime)): 1.5 parts Cyclohexanone: 39.0 parts

[Examples 60 to 109, 209 to 216, Comparative Examples 5 to 8]
(Photosensitive pigment compositions (R-2 to R-55, 209 to 216))
As shown in Tables 4-1 and 4-2, photosensitive pigment compositions (R-2 to R-55, 209 to 216) were obtained in the same manner as in the case of the photosensitive pigment composition (R-1), except that the type of the pigment composition 1 was changed.

<Evaluation of Photosensitive Pigment Composition>
The resulting photosensitive pigment composition was evaluated for brightness, coating foreign matter, and developability by the methods described below. The evaluation results are shown in Table 4.

(brightness)
The obtained photosensitive pigment composition was applied to a 100 mm x 100 mm, 1.1 mm thick glass substrate using a spin coater so that the dry film thickness was 2.0 μm, and after drying at 70° C. for 20 minutes, it was further heated at 230° C. for 60 minutes to obtain a coated substrate with a chromaticity of x = 0.655, y = 0.320 under light source C. The luminance (Y) of the obtained substrate was measured with a microspectrophotometer ("OSP-SP200" manufactured by Olympus Optical Co., Ltd.).

(Foreign matter on coating)
The coating substrates prepared for the brightness evaluation were used to evaluate the coating foreign matter by surface observation. The evaluation was performed using a metal microscope "BX60" manufactured by Olympus Systems. The magnification was set to 500 times, and the number of particles observable in any five visual fields in transmission was counted. The evaluation criteria are shown below.
◎: The number of foreign objects is less than 5 (very good)
○: The number of foreign objects is 5 or more and less than 10 (good)
△: The number of foreign objects is 10 or more and less than 60 (defective)
×: The number of foreign objects is 60 or more (extremely poor)

(Developability)
The obtained photosensitive pigment composition was applied to a glass substrate using a slit die coater so that the dry film thickness was 2.4 μm, and then prebaked on a hot plate at 90° C. for 2 minutes to form a substrate having a coating film. The substrate was then cooled to room temperature, and the coating film was exposed to radiation having wavelengths of 365 nm, 405 nm, and 436 nm at an exposure dose of 1,000 J/m2 using a high-pressure mercury lamp through a striped photomask. After alkaline development, the substrate was washed with ultrapure water and further postbaked at 230° C. for 20 minutes to form red striped pixels on the substrate. The time required for the striped pixels to be developed during alkaline development was measured, and the developability was evaluated according to the following criteria.
◎: Developed within 20 seconds (very good)
○: Developed within 30 seconds (good)
△: Developed within 60 seconds (poor)
×: Developed within 120 seconds (very poor)

The results in Tables 4-1 and 4-2 reveal that the examples of the present invention have excellent brightness, good coating foreign matter and good developability. Among these, it can be seen that the use of a basic dispersant (B) having a hydroxyl group or a carboxyl group particularly improves brightness and developability.

<Method for producing green and blue photosensitive pigment compositions>
(Green photosensitive pigment composition 1: PG58/PY138)
The mixture having the following composition was stirred and mixed to a uniform consistency, and then filtered through a filter having a pore size of 1 μm to prepare green photosensitive pigment composition 1.
Green pigment composition (M-56): 32.0 parts Yellow pigment composition (M-54): 18.0 parts Acrylic resin solution 2: 7.5 parts Photopolymerizable monomer ("Aronix M-402" manufactured by Toagosei Co., Ltd.): 2.0 parts Photopolymerization initiator ("OXE-02" manufactured by BASF Japan Co., Ltd.): 1.5 parts Cyclohexanone: 39.0 parts

Blue photosensitive pigment composition 1 was obtained in the same manner as green photosensitive pigment composition 1, except that 32.0 parts of the green pigment composition and 18.0 parts of the yellow pigment composition were replaced with 46.0 parts of blue pigment composition (M-57) and 4.0 parts of purple pigment composition (M-58), totaling 50.0 parts.

<Production and Evaluation of Color Filters>
The photosensitive pigment composition (R-1) was applied onto a glass substrate on which a black matrix had been formed, using a slit die coater, and then prebaked on a hot plate at 90°C for 2 minutes to form a coating film. Next, the substrate on which the coating film had been formed was cooled to room temperature, and the coating film was exposed to radiation containing wavelengths of 365 nm, 405 nm, and 436 nm at an exposure dose of 1,000 J/m2 using a high-pressure mercury lamp through a striped photomask. After alkali development, the substrate was washed with ultrapure water, and further postbaked at 230°C for 20 minutes to form red striped pixels on the substrate.
Next, in the same manner, a green stripe-shaped pixel was formed adjacent to the red stripe-shaped pixel using green photosensitive pigment composition 1. Furthermore, a blue stripe-shaped pixel adjacent to the red and green pixels was formed in the same manner using blue photosensitive pigment composition 1.
Next, a protective film was formed on the pixels of three colors, red, green, and blue, using a photocurable resin composition. In this way, an RGB three-color filter having high brightness and excellent coating foreign matter and developability was produced.

Claims (8)

A pigment (A), a basic dispersant (B), and an acidic dispersant (C),
The basic dispersant (B) is an A-B or B-A-B block polymer synthesized by living radical polymerization, in which the A block has product units of a compound having a nitrogen-containing heterocyclic group having aromaticity and a functional group capable of reacting with an isocyanate group or an epoxy group, and a monomer unit having an isocyanate group or an epoxy group, and the B block has a monomer unit of a (meth)acrylic acid ester. The pigment composition according to claim 1, wherein the molar ratio of the A block to the B block of the basic dispersant (B) is A/(A+B) = 5 to 70 mol % for the A-B block polymer and A/(A+B) = 10 to 70 mol % for the B-A-B block polymer. The pigment composition according to claim 1 or 2, wherein the mass ratio of the pigment (A), the basic dispersant (B), and the acidic dispersant (C) satisfies A/A+B+C>0.5. The pigment composition according to any one of claims 1 to 3, wherein the functional group capable of reacting with an isocyanate group or an epoxy group is an amino group. The pigment composition according to any one of claims 1 to 4, wherein the pigment (A) is at least one selected from the group consisting of azo pigments, diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, indole pigments, quinophthalone pigments, phthalocyanine pigments, and dioxazine pigments. A photosensitive pigment composition comprising the pigment composition according to any one of claims 1 to 5, a photopolymerizable monomer, and a photopolymerization initiator. A color filter comprising a substrate and filter segments formed from the photosensitive pigment composition according to claim 6. A display device comprising the color filter according to claim 7.