Pigment dispersion composition for black matrix

Abstract

Provided is a pigment dispersion composition for a black matrix, the pigment dispersion composition having excellent storage stability and being capable of suppressing a decrease in the OD value (optical concentration) during a stand-by time between application of a resist to a substrate and pre-baking, and the resulting resist film having excellent thin wire adhesion. The pigment dispersion composition for a black matrix comprises lactam black, silica-based particles, a pigment dispersant containing a basic group, and an alkali-soluble resin, and satisfies at least one of the following conditions A and B. (Condition A) No carbon black is included. (Condition B) Carbon black is included, and the average primary particle diameter of the carbon black is 30 nm or more.

Description

Technical Field

[0001] The present invention relates to a pigment dispersion composition for a black matrix. More specifically, the present invention relates to a pigment dispersion composition for a black matrix having excellent storage stability, capable of suppressing a decrease in OD value (optical density) during the standby time between coating a resist on a substrate and prebaking, and having excellent fine line adhesion of the obtained resist film. Background Art

[0002] In the past, in flexible displays, for anti-reflection, color filters were used to replace the circular polarizers used in anti-reflection. The black partition wall used in the color filter requires a lower reflectivity than in the past. The pigment dispersion composition for the black matrix used to obtain such a black partition wall comprises lactam black and carbon black as a colorant (refer to patent document 1). However, in order to make the production efficiency of the black matrix, the panel manufacturer will not pre-bake the glass substrate coated with the resist immediately, but adopt a process of pre-bake after concentrating the substrates after multiple coatings. Therefore, among multiple substrates, the substrates pre-bake just after coating and the substrates pre-bake after about 10 minutes of standby time after coating are mixed together.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-177204 Summary of the invention

[0006] However, if a resist film is prepared using the pigment dispersion composition described in Patent Document 1, the obtained resist film has poor fine line adhesion, making it difficult to obtain a high-definition display. After applying the pigment dispersion composition described in Patent Document 1, a substrate pre-baked after a long standby time has a problem of lower optical density (OD value) than a substrate pre-baked immediately after application.

[0007] The present invention has been made in view of such conventional problems, and its object is to provide a pigment dispersion composition for a black matrix which has excellent storage stability, can suppress the decrease in OD value (optical density) during the waiting time between coating a resist on a substrate and prebaking, and has excellent fine line adhesion of the obtained resist film.

[0008] In order to solve the above problems, the inventors conducted intensive research and found that the above problems can be solved simultaneously by including lactam black, silica particles, a pigment dispersant containing a basic group, and an alkali-soluble resin, without including carbon black or including carbon black with a predetermined average primary particle size, and thus completed the present invention. The present invention for solving the above problems mainly has the following structure.

[0009] (1) A pigment dispersion composition for a black matrix, comprising lactam black, silica-based particles, a pigment dispersant containing a basic group, and an alkali-soluble resin, wherein the pigment dispersion composition for a black matrix satisfies at least one of the following conditions A or B.

[0010] (Condition A) Carbon black is not contained.

[0011] (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0012] According to such a configuration, the pigment dispersion composition for a black matrix has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between application of a resist to a substrate and prebaking, and the obtained resist film has excellent fine line adhesion.

[0013] (2) The pigment dispersion composition for a black matrix according to (1), wherein the basic group-containing pigment dispersant is an acrylic dispersant.

[0014] According to such a configuration, the pigment dispersion composition for black matrix can provide a high-definition display.

[0015] (3) The pigment dispersion composition for a black matrix according to (2), wherein the acrylic dispersant has a glass transition temperature (Tg) of 10° C. or higher.

[0016] According to such a configuration, the resist film obtained from the pigment dispersion composition for a black matrix has more excellent fine line adhesion.

[0017] (4) The pigment dispersion composition for a black matrix according to any one of (1) to (3), wherein the silica-based particles are a polymer / silica composite.

[0018] According to such a configuration, the pigment dispersion composition for a black matrix can provide a display having a low reflectance.

[0019] (5) The pigment dispersion composition for a black matrix according to any one of (1) to (4), wherein the alkali-soluble resin is an acrylic resin or an epoxy acrylate resin.

[0020] According to such a configuration, the pigment dispersion composition for black matrix can obtain a high-definition display.

[0021] (6) A resist composition for a black matrix, comprising the pigment dispersion composition for a black matrix according to any one of (1) to (5).

[0022] According to such a configuration, the storage stability of the black matrix resist composition is excellent. In addition, the black matrix resist composition can suppress the reduction of the OD value (optical density) in the standby time between the substrate coating resist and pre-baking. The reflectivity of the obtained resist film is low, and the fine line adhesion is excellent, so that a high-precision display can be obtained.

[0023] (7) A black matrix formed from the resist composition for a black matrix according to (6).

[0024] According to such a configuration, the reflectance of the black matrix is ​​low, and a high-definition display can be obtained.

[0025] According to the present invention, a pigment dispersion composition for a black matrix can be provided which has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between coating a resist on a substrate and prebaking, and can produce a resist film having excellent fine line adhesion. DETAILED DESCRIPTION

[0026] <Pigment dispersion composition for black matrix>

[0027] The pigment dispersion composition for black matrix of one embodiment of the present invention (hereinafter also referred to as pigment dispersion composition) comprises lactam black, silica particles, a pigment dispersant containing a basic group and an alkali-soluble resin. The pigment dispersion composition satisfies at least one of the following conditions A or B. The following are described separately.

[0028] (Condition A) Carbon black is not contained.

[0029] (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0030] (Lactam Black)

[0031] Lactam black can be any known lactam black. If an example is given, the lactam black of the present embodiment has the following main skeleton, more specifically Irgaphor Black S 0100CF (BASF company system) etc. In addition, when having the following main skeleton, the hydrogen atoms in the main skeleton can be appropriately replaced by low molecular functional groups (such as alkyl, alkenyl, alkynyl and other hydrocarbon groups, carboxyl, sulfonic acid, phosphonic acid and other acidic groups, amino and other basic groups, hydroxyl groups, etc.) or halogen atoms.

[0032]

[0033] The value of the volume reference particle diameter D50 of the lactam black of the present embodiment is preferably 70nm or more, more preferably 85nm or more. In addition, the value of D50 is preferably 130nm or less, more preferably 115nm or less. By the value of D50 being within the above range, the pigment of the obtained pigment dispersion composition is not easy to settle, and the storage stability is good. In addition, the linearity and roughness of the obtained resist film of the pigment dispersion composition are good.

[0034] The value of volume reference particle diameter D90 of lactam black is preferably 160nm or more, more preferably 180nm or more. In addition, the value of D90 is preferably 300nm or less, more preferably 280nm or less. By the value of D90 being within the above range, the pigment of the obtained pigment dispersion composition is not easy to settle, and the storage stability is good. In addition, the linearity and roughness of the obtained resist film of the pigment dispersion composition are good.

[0035] In the present embodiment, the volume-based particle size can be measured by a laser diffraction particle size measurement method using Nanotrac (UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0036] The content of lactam black is not particularly limited. As an example, the content of lactam black is preferably 3% by mass or more, more preferably 5% by mass or more, in the pigment dispersion composition. In addition, the content of lactam black is preferably 25% by mass or less, more preferably 20% by mass or less, in the pigment dispersion composition. When the content of lactam black is within the above range, the OD value and development adhesion of the resist film obtained by the pigment dispersion composition become good.

[0037] (Silica-based particles)

[0038] The silica particles are not particularly limited. If an example is given, the silica particles are selected from aerosil, colloidal silica, polymer / silicon dioxide composites, etc. In the present embodiment, the silica particles are matched to reduce the reflectivity of the obtained resist film. In addition, the silica particles can also be subjected to trimethylsilyl treatment on the surface.

[0039] The silica particles preferably include a polymer / silica composite. The polymer / silica composite is a particle formed by combining organic polymer particles with silica particles. In this embodiment, by including the polymer / silica composite, the pigment dispersion composition can easily obtain a display with low reflectivity.

[0040] The particle diameter of the silica-based particles is preferably more than 5nm, more preferably more than 10nm. In addition, the average primary particle diameter of the silica-based particles is preferably less than 200nm, more preferably less than 150nm. By particle diameter within the above range, the pigment of the black matrix resist composition obtained by the pigment dispersion composition is not easy to settle, and the storage stability is excellent. It should be noted that, in the present embodiment, the particle diameter can be calculated by electron microscope observation The value of the arithmetic mean diameter, or in the case of a commercially available product, the catalog value can be used as a reference.

[0041] The BET specific surface area of ​​the silica particles is preferably 10 m 2 / g or more, more preferably 20m 2 / g or more. In addition, the BET specific surface area is preferably 200m 2 / g or less, more preferably 180m 2 / g or less. When the BET specific surface area is within the above range, the reflectivity of the obtained resist film can be easily reduced. It should be noted that in the present embodiment, the BET specific surface area is measured by a method such as JIS Z8830:2013, or in the case of commercial products, a catalog value can be used as a reference.

[0042] (Pigment dispersant containing basic group)

[0043] The pigment dispersant containing a basic group is not particularly limited. If an example is given, the pigment dispersant containing a basic group is an acrylic dispersant, a carbamate dispersant, etc. Among these, the pigment dispersant containing a basic group is preferably an acrylic dispersant. Thus, the pigment dispersion composition easily obtains a high-definition display.

[0044] Acrylic dispersant

[0045] The acrylic dispersant includes a block copolymer (acrylic block copolymer). The acrylic block copolymer is not particularly limited. As an example, the acrylic block copolymer is an acrylic block copolymer containing an amine compound as a monomer.

[0046] The types of blocks constituting the acrylic block copolymer containing a monomer as an amine compound may be two or three or more, and one or more of the blocks is a block containing a monomer having a radically polymerizable unsaturated bond as an amine compound.

[0047] The monomer constituting the block is a non-cyclic amine compound, a heterocyclic amine compound or a quaternary ammonium cationic compound, preferably a non-cyclic amine compound such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dimethylaminobutyl (meth) acrylate, vinyl pyridine, heterocyclic amine compounds such as pentamethyl piperidinyl (meth) acrylate, and a compound obtained by quaternizing dimethylaminopropyl (meth) acrylate with benzyl chloride and cationizing it, etc. Quaternary ammonium cationic compounds, etc. can be a block consisting of one monomer in these monomers. It can also be a block formed by random polymerization of more than two monomers or a block formed by block polymerization of more than two monomers. In addition, it is particularly preferred to have a material having a structure consisting of a block of pentamethyl piperidinyl methacrylate and / or dimethylaminopropyl acrylate and a block comprising other ethylenically unsaturated monomers that can be polymerized.

[0048] The other polymerizable blocks copolymerized with the block from the monomer as an amine compound can be a block composed of one monomer, or a block formed by random polymerization of two or more monomers. It is preferred that there is no unit from a monomer containing an amino group or a pyridine ring. In addition, it is further preferred that there is no carboxylic acid group, hydroxyl group, thiol group, group containing sulfur or phosphorus. It should be noted that the block composed of other polymerizable ethylenically unsaturated monomers can be one or two blocks.

[0049] The other polymerizable ethylenically unsaturated monomer is a copolymer with at least one ethylenically unsaturated monomer selected from the group consisting of monomers and oligomers such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, styrene, 2-hydroxyethyl (meth)acrylate, allyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, glycerol (meth)acrylate such as glycerol monoacrylate, N-phenylmaleimide, polystyrene macromonomer, polymethyl methacrylate macromonomer, carboepoxy diacrylate, etc. Among them, it is preferred not to use N-ethylpyrrolidone or monomers containing sulfur.

[0050] The block copolymer may be a block resin synthesized by living radical polymerization or anionic polymerization.

[0051] The amine value of the acrylic dispersant is preferably more than 0 mgKOH / g and 140 mgKOH / g or less.

[0052] The glass transition temperature (Tg) of the acrylic dispersant is not particularly limited. As an example, Tg is preferably 10° C. or higher, and more preferably 20° C. or higher. When the Tg of the acrylic dispersant is within the above range, the fine line adhesion of the resist film obtained from the pigment dispersion composition is further improved.

[0053] The content of the acrylic dispersant is not particularly limited. As an example, the content of the acrylic dispersant in the pigment dispersion composition is preferably 0.5% by mass or more, more preferably 1.0% by mass or more. In addition, the content of the acrylic dispersant in the pigment dispersion composition is preferably 30.0% by mass or less, more preferably 25.0% by mass or less. When the content of the acrylic dispersant is within the above range, the dispersion stability of the pigment dispersion composition is excellent.

[0054] Urethane dispersants

[0055] The urethane dispersant can be obtained by reacting a compound having a number average molecular weight of 300 to 10,000 and having one or more hydroxyl groups in the molecule and a compound having a basic group in the molecule and having a functional group capable of reacting with an isocyanate group with an isocyanate group of a polyisocyanate compound. The method for obtaining such a urethane dispersant can be the method described in Japanese Patent Application Laid-Open No. 60-166318.

[0056] The polyisocyanate compound constituting the urethane dispersant may include an isocyanate compound having two or more isocyanate groups. For example, the isocyanate compound having two or more isocyanate groups is an aromatic diisocyanate compound such as 2,4-toluene diisocyanate, a dimer of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, Aliphatic or alicyclic polyisocyanates such as 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate, and 1,3-(isocyanate methylene) cyclohexane; polyisocyanates having an isocyanuric group based on diisocyanates (polyisocyanates having an isocyanuric group formed by trimerization of diisocyanates, etc.), polyisocyanates obtained by reacting diisocyanates with polyols, polyisocyanates obtained by biuret reaction of diisocyanate compounds, etc. The polyisocyanate compound is preferably a polyisocyanate having an isocyanuric group based on diisocyanates such as toluene diisocyanate and isophorone diisocyanate.

[0057] The compound having one or more hydroxyl groups in the molecule constituting the urethane dispersant is a polyether compound, a polyester compound, or the like.

[0058] The above-mentioned polyether compounds are polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polytetramethylene glycol; alkylene glycols such as ethylene glycol, propane glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexanediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, di(trimethylol)propane, and dipentaerythritol; and ethylene oxide-modified products, propylene oxide-modified products, butylene oxide-modified products, and tetrahydrofuran-modified products of low molecular weight monohydric alcohols such as methanol and ethanol.

[0059] The polyester compound is, for example, ethylene glycol, propane diol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexanediol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, di(trimethylol)propane, dipentaerythritol and other alkylene glycols, methanol, ethanol and other low molecular weight monohydric alcohols, epsilon-caprolactone modified products, gamma-butyrolactone modified products, delta-valerolactone modified products, methylvalerolactone modified products; aliphatic polyester polyols, such as adipic acid, dimer acid and other aliphatic dicarboxylic acids and neopentyl glycol, methylpentanediol and other polyols, esters thereof. Polyols; esters of aromatic dicarboxylic acids such as terephthalic acid and polyols such as neopentyl glycol, i.e., aromatic polyester polyols and other polyester polyols; esters of polyhydroxy compounds such as polycarbonate polyols, acrylic polyols, polytetramethylene hexaglyceryl ether (tetrahydrofuran modified hexaglycerol) and dicarboxylic acids such as fumaric acid, phthalic acid, isophthalic acid, itaconic acid, adipic acid, sebacic acid, and maleic acid; compounds containing polyhydroxy groups such as monoglycerides obtained by transesterification of compounds containing polyhydroxy groups such as glycerol and fatty acid esters, etc. The above-mentioned compound having one or more hydroxyl groups in the molecule is preferably an ε-caprolactone adduct of an alcohol.

[0060] The number average molecular weight of the compound having one or more hydroxyl groups in the molecule is 300 to 10000, and more preferably 300 to 6000. The number average molecular weight can be measured by column chromatography.

[0061] The compound containing a basic group having a functional group capable of reacting with an isocyanate group in the molecule constituting the above-mentioned carbamate-based dispersant is not particularly limited. As an example, the compound containing a basic group having a functional group capable of reacting with an isocyanate group in the molecule constituting the carbamate-based dispersant is at least one compound selected from polyols, polythiols and amines having an N,N-disubstituted amino group or a heterocyclic nitrogen atom. These compounds are compounds having a Zerevitinoff-active hydrogen atom and at least one basic group containing a nitrogen atom. Such compounds include N,N-dimethyl-1,3-propylenediamine, N,N-diethyl-1,4-butanediamine, 2-dimethylaminoethanol, 1-(2-aminoethyl)-piperazine, 2-(1-pyrrolidinyl)-ethylamine, 4-amino-2-methoxypyrimidine, 4-(2-aminoethyl)-pyridine, 1-(2-hydroxyethyl)-piperazine, 4-(2-hydroxyethyl)-morpholine, 2-mercaptopyrimidine, 2-mercaptobenzimidazole, 2-amino-6-methoxybenzothiazole, N,N-diallyl-melamine, 3-amino-1,2,4-triazole, 1-(2-hydroxyethyl)-imidazole, 3-mercapto-1,2,4-triazole, and the like, and amines having a heterocyclic nitrogen atom are preferred.

[0062] The reaction in the synthesis of the urethane dispersant is not particularly limited. In addition, the amine value of the urethane dispersant is preferably greater than 0 mgKOH / g and not more than 40 mgKOH / g.

[0063] Commercially available products of the urethane dispersant include Disperbyk (registered trademark)-161 (amine value 11 mgKOH / g, manufactured by BYK-Chemie), Disperbyk (registered trademark)-162 (amine value 13 mgKOH / g, manufactured by BYK-Chemie), Disperbyk (registered trademark)-167 (amine value 13 mgKOH / g, manufactured by BYK-Chemie), Disperbyk (registered trademark)-182 (amine value 13 mgKOH / g, manufactured by BYK-Chemie), Disperbyk (registered trademark)-2163 (amine value 10 mgKOH / g, manufactured by BYK-Chemie), and Disperbyk (registered trademark)-2164 (amine value 14 mgKOH / g, manufactured by BYK-Chemie).

[0064] The content of the carbamate dispersant is not particularly limited. As an example, the content of the carbamate dispersant in the pigment dispersion composition is preferably 0.5% by mass or more, more preferably 1.0% by mass or more. In addition, the content of the carbamate dispersant in the pigment dispersion composition is preferably 30.0% by mass or less, more preferably 25.0% by mass or less. When the content of the carbamate dispersant is within the above range, the dispersion stability of the pigment dispersion composition is excellent.

[0065] (Alkali soluble resin)

[0066] By including an alkali-soluble resin, the dispersion can be developed by an alkali developer, and patterns of partitions etc. can be produced. The alkali-soluble resin is not particularly limited. If an example is given, the alkali-soluble resin is an acrylic resin, an epoxy acrylate resin, a urethane acrylate resin, etc. Among these, the alkali-soluble resin is preferably an acrylic resin or an epoxy acrylate resin. Thus, the pigment dispersion composition easily obtains a high-definition display.

[0067] The alkali-soluble resin is not particularly limited. As an example, the alkali-soluble resin is a resin containing an anionic group such as a carboxyl group, a sulfonic acid group, or a phosphonic acid group (-P(=O)(OH2)).

[0068] The acrylic resin is not particularly limited, but as an example, the acrylic resin is "Follett" series, ZAH-106, ZAH-110, ZAH-115, ZAH-310, etc. manufactured by Soken Chemical Co., Ltd.

[0069] The epoxy acrylate resin is not particularly limited. For example, the epoxy acrylate resin is "KAYARAD" series manufactured by Nippon Kayaku Co., Ltd., CCR-1291H, CCR-1235, ZAR-1035, ZAR-2000, ZFR-1401H, ZFR-1491H, ZCR-1569H, ZCR-1601H, ZCR-1797H, ZCR-1798H, UXE-3000, UXE-3024, etc.

[0070] The urethane acrylate resin is not particularly limited, but as an example, the urethane acrylate resin is "KAYARAD" series, UX-3204, UX-4101, UXT-6100, UX-8101, UX-0937, DPHA-40H, UX-5000, etc. manufactured by Nippon Kayaku Co., Ltd.

[0071] From the viewpoint of alkali developability, the acid value of the alkali-soluble resin is preferably 10 mgKOH / g or more, more preferably 20 mgKOH / g or more, and the acid value is preferably 300 mgKOH / g or less, more preferably 200 mgKOH / g or less.

[0072] From the viewpoint of the formation of the resist film, the weight average molecular weight of the alkali-soluble resin is preferably 1000 or more, more preferably 3000 or more. In addition, from the viewpoint of improving solubility, the weight average molecular weight of the alkali-soluble resin is preferably 100000 or less, more preferably 50000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC). As an example, Water2690 (manufactured by Waters) is used as a GPC device, PLgel, 5μ, MIXED-D (manufactured by Polymer Laboratories) is used as a column, and tetrahydrofuran is used as a developing solvent. Chromatography is performed under the conditions of column temperature 25°C, flow rate 1 ml / min, RI detector, sample injection concentration 10 mg / ml, and injection volume 100 microliters, and the weight average molecular weight converted to polystyrene is obtained.

[0073] Alkali-soluble resins include acrylic copolymer resins, maleic copolymer resins, polyester resins obtained by polycondensation reaction, epoxy acrylate resins obtained by addition polymerization reaction of acrylic acid and epoxy compounds, urethane acrylate resins obtained by polymerization reaction of acrylic acid, polyols and isocyanate compounds, etc. Among these, the alkali-soluble resin is preferably an acrylic copolymer resin or an epoxy acrylate resin from the aspects of excellent developability and fine line adhesion.

[0074] The content of the alkali-soluble resin is not particularly limited. If an example is given, the content of the alkali-soluble resin is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, relative to a total of 100 parts by mass of the components matched as the pigment. In addition, the content of the alkali-soluble resin is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, relative to a total of 100 parts by mass of the components matched as the pigment. Here, lactam black, carbon black, and aluminum hydroxide of an optional component described later are in accordance with the components matched as the pigment.

[0075] (Pigment dispersing aid with acidic group)

[0076] For the purpose of further improving the dispersibility of the pigment, the pigment dispersion composition of the present embodiment preferably includes a pigment dispersing aid with an acidic group. The pigment dispersing aid with an acidic group is a compound (pigment derivative with an acidic group) introduced into pigments such as perylene compounds, diketopyrrolopyrrole compounds, azonaphthol compounds, dioxazine compounds, quinacridone compounds, phthalocyanine compounds and their metal complexes, anthraquinone, naphthalene, acridone or triazine, etc., and the compound obtained by neutralizing them with organic amines, etc. From the aspect that the dispersibility of lactam black and carbon black described later is good, the pigment derivative with an acidic group is preferably a phthalocyanine pigment derivative with a sulfonic acid group.

[0077] The amount of the pigment dispersing aid having an acidic group is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, based on 100 parts by mass of lactam black.

[0078] (Carbon Black)

[0079] The pigment dispersion composition of the present embodiment is characterized by satisfying at least any one of the following conditions A to C in relation to the presence or absence and type of carbon black.

[0080] (Condition A) Carbon black is not contained.

[0081] (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0082] About Condition A

[0083] Condition A stipulates that the pigment dispersion composition does not include carbon black. The pigment dispersion composition satisfying condition A, even if it does not include carbon black, has excellent storage stability in the obtained black matrix resist composition. In addition, the obtained black matrix resist composition can suppress the reduction of the OD value (optical density) in the standby time between the substrate coating resist and pre-baking. And then, the reflectivity of the obtained resist film is low, and an extremely high-precision display can be obtained.

[0084] Condition B

[0085] Condition B stipulates that carbon black is contained and the average primary particle size of the carbon black is 30 nm or more.

[0086] The average primary particle size of carbon black is not particularly limited except that it is 30 nm or more. As an example, carbon black is neutral carbon black, acidic carbon black, or the like.

[0087] The pH of neutral carbon black is preferably in the range of pH 8 to 10.

[0088] The acidic carbon black preferably has a pH in the range of 2 to 4.

[0089] It should be noted that in the present embodiment, in the case of commercially available carbon black, the pH may adopt the catalog value, and when measuring, 1 g of carbon black may be added to 20 mL of distilled water (pH 7.0) excluding carbonic acid and mixed with a magnetic stirrer to prepare an aqueous suspension, and the measurement may be performed at 25° C. using a glass electrode (German industrial product standard DIN ISO 787 / 9). In addition, in the present embodiment, the average primary particle size is the value of the arithmetic mean diameter obtained by electron microscope observation, or in the case of commercially available carbon black, the catalog value may be adopted.

[0090] The average primary particle size of carbon black may be 30 nm or more, and more preferably 31 nm or more. When the average primary particle size of carbon black is 30 nm or more, the fine line adhesion of the resist film obtained from the pigment dispersion composition becomes good.

[0091] The specific surface area of ​​carbon black is preferably less than 64 m 2 / g, more preferably 60m 2 When the specific surface area of ​​carbon black is within the above range, the fine line adhesion of a resist film obtained from the pigment dispersion composition becomes good.

[0092] The content of carbon black is not particularly limited. If an example is given, the content of carbon black is preferably 1% by mass or more in the pigment dispersion composition, and more preferably 5% by mass or more. In addition, the content of carbon black is preferably 35% by mass or less in the pigment dispersion composition, and more preferably 30% by mass or less. When the content of carbon black is within the above range, the dispersibility of the carbon black of the pigment dispersion composition is excellent, and the light shielding property when forming a black matrix is ​​excellent.

[0093] The pigment dispersion composition satisfying condition B is excellent in storage stability in the obtained black matrix resist composition. In addition, the obtained black matrix resist composition can suppress the reduction of the OD value (optical density) in the standby time between the substrate coating resist and pre-baking. Furthermore, the reflectivity of the obtained resist film is low, and a high-definition display can be obtained.

[0094] (Solvent)

[0095] The pigment dispersion composition of the present embodiment may also contain a solvent. The solvent is not particularly limited. If an example is given, from the viewpoint of stably dispersing lactam black and fully dissolving alkali-soluble resins, the solvent is preferably an ester solvent, an ether solvent, an ether-ester solvent, a ketone solvent, an aromatic hydrocarbon solvent, a nitrogen-containing solvent, etc.

[0096] The ester solvents include methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 3-methyl-3-methoxybutylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, glycolate, n-pentyl formate, and the like.

[0097] The ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol methyl ethyl ether.

[0098] The ether ester solvents include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like.

[0099] Ketone solvents include methyl isobutyl ketone, cyclohexanone, 2-heptanone, δ-butyrolactone and the like.

[0100] Aromatic hydrocarbon solvents include toluene, xylene, alkylnaphthalene and the like.

[0101] The nitrogen-containing solvent is N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and the like.

[0102] When a solvent is included, the content of the solvent is not particularly limited. As an example, the content of the solvent is preferably 40% by mass or more, more preferably 50% by mass or more, in the pigment dispersion composition. In addition, the content of the solvent is preferably 90% by mass or less, more preferably 80% by mass or less, in the pigment dispersion composition. When the content of the solvent is within the above range, the dispersion stability of the lactam black of the pigment dispersion composition is excellent.

[0103] (Aluminum Hydroxide)

[0104] The pigment dispersion composition of the present embodiment preferably contains aluminum hydroxide because the thin line adhesion of the obtained resist film becomes good.

[0105] In the case of comprising aluminum hydroxide, the content of aluminum hydroxide is not particularly limited. If an example is given, the content of aluminum hydroxide is preferably more than 0.1 mass % in the pigment dispersion composition, and more preferably more than 0.2 mass %. In addition, the content of aluminum hydroxide is preferably less than 5 mass % in the pigment dispersion composition, and more preferably less than 3 mass %. By the content of aluminum hydroxide in the above range, the storage stability of the pigment dispersion composition is good, and the fine line adhesion of the obtained resist film becomes good.

[0106] Returning to the overall description of the pigment dispersion composition, the method for preparing the pigment dispersion composition of the present embodiment is not particularly limited. As an example, the pigment dispersion composition can be prepared by mixing various materials and kneading them overnight using a bead mill or the like.

[0107] The storage stability of the black matrix resist composition obtained using the pigment dispersion composition of the present embodiment is excellent. In addition, the obtained black matrix resist composition can suppress the reduction of the OD value (optical density) in the standby time between the substrate coating resist and pre-baking. The reflectivity of the obtained resist film is low, and a high-precision display can be obtained.

[0108] <Resist composition for black matrix>

[0109] A resist composition for a black matrix (hereinafter, also referred to as a resist composition) according to one embodiment of the present invention includes the above-mentioned pigment dispersion composition for a black matrix.

[0110] The content of the pigment dispersion composition in the resist composition is not particularly limited. If an example is given, the content of the pigment dispersion composition is preferably 27% by mass or more, more preferably 30% by mass or more. In addition, the content of the pigment dispersion composition is preferably 40% by mass or less, more preferably 37% by mass or less. By the content of the pigment dispersion composition being within the above range, it is easy to take into account both fine line adhesion and OD value.

[0111] The resist composition of this embodiment may contain any components conventionally formulated as a resist composition in addition to the above-mentioned pigment dispersion composition, for example, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, a surface modifier, a solvent, and the like.

[0112] (Alkali soluble resin)

[0113] The alkali-soluble resin is appropriately blended to improve the developability by an alkali developer. The alkali-soluble resin is not particularly limited, and for example, the above-mentioned alkali-soluble resin may be contained in association with the pigment dispersion composition. Among these, the alkali-soluble resin is preferably an acrylic copolymer resin or an epoxy acrylate resin from the aspect of excellent developability and fine line adhesion.

[0114] When an alkali-soluble resin is included, the content of the alkali-soluble resin is not particularly limited. As an example, the content of the alkali-soluble resin is preferably 3% by mass or more, more preferably 5% by mass or more, in the resist composition. In addition, the content of the alkali-soluble resin is preferably 15% by mass or less, more preferably 12% by mass or less in the resist composition. When the content of the alkali-soluble resin is within the above range, the developability of the resist composition based on an alkali developer becomes an appropriate range.

[0115] (Photopolymerizable compound)

[0116] The photopolymerizable compound is not particularly limited, but as an example, the photopolymerizable compound is a monomer, an oligomer, or the like having a photopolymerizable unsaturated bond.

[0117] The monomer having one photopolymerizable unsaturated bond is an alkyl methacrylate or alkyl acrylate such as methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate; an aralkyl methacrylate or aralkyl acrylate such as benzyl methacrylate or benzyl acrylate; an alkoxyalkyl methacrylate or alkoxyalkyl acrylate such as butoxyethyl methacrylate or butoxyethyl acrylate; an aminoalkyl methacrylate or aminoalkyl acrylate such as N,N-dimethylaminoethyl methacrylate or N,N-dimethylaminoethyl acrylate; a methacrylate or acrylate of a polyalkylene glycol monoalkyl ether such as diethylene glycol monoethyl ether, triethylene glycol monobutyl ether, dipropylene glycol monomethyl ether; a methacrylate or acrylate of a polyalkylene glycol monoaryl ether such as hexaethylene glycol monophenyl ether; isobornyl methacrylate or isobornyl acrylate; glyceryl methacrylate or glyceryl acrylate; 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate, and the like.

[0118] The monomer having two or more photopolymerizable unsaturated bonds is bisphenol A dimethacrylate, 1,4-butylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, diquaternary Pentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, diethylene glycol diacrylate, glycerol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, etc.

[0119] The oligomer having a photopolymerizable unsaturated bond is obtained by appropriately polymerizing the above-mentioned monomers, and the like.

[0120] In the case of including a photopolymerizable compound, the content of the photopolymerizable compound is not particularly limited. As an example, the content of the photopolymerizable compound is preferably 1% by mass or more, more preferably 2.5% by mass or more in the resist composition. In addition, the content of the photopolymerizable compound is preferably 15% by mass or less, more preferably 10% by mass or less in the resist composition. By having the content of the photopolymerizable compound within the above range, the resist composition can take into account both the curability and alkali developability of the resist film.

[0121] (Photopolymerization Initiator)

[0122] The photopolymerization initiator is not particularly limited. As an example, the photopolymerization initiator is benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, benzil, 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzil dimethyl ketal, α-hydroxyisobutylbenzophenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, tert-butyl anthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 1,2-benzanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, triazine-based photopolymerization initiators, oxime ester-based photopolymerization initiators, and the like.

[0123] When a photopolymerization initiator is included, the content of the photopolymerization initiator is not particularly limited. As an example, the content of the photopolymerization initiator is preferably 0.1% by mass or more, more preferably 0.3% by mass or more in the resist composition. In addition, the content of the photopolymerization initiator is preferably 5% by mass or less, more preferably 2% by mass or less in the resist composition. When the content of the photopolymerization initiator is within the above range, the resist composition can take into account both the curability and fine line adhesion of the resist film.

[0124] Furthermore, additives such as a leveling agent, an antioxidant, and a defoaming agent may be added to the resist composition as necessary.

[0125] The method for preparing the resist composition of the present embodiment is not particularly limited. As an example, the resist composition can be prepared by stirring and mixing various materials using a stirring device or the like.

[0126] The resist composition of the present embodiment has excellent storage stability. In addition, the resist composition can suppress the decrease of the OD value (optical density) during the standby time between applying the resist to the substrate and pre-baking. The obtained resist film has low reflectivity and excellent fine line adhesion, thereby obtaining a high-definition display.

[0127] <Black Matrix>

[0128] The black matrix according to one embodiment of the present invention is a black matrix formed from the above-mentioned resist composition.

[0129] The formation method of the black matrix is ​​not particularly limited. If an example is given, the formation method of the black matrix is ​​as follows: the black matrix resist composition of the above-mentioned embodiment is applied to the substrate, dried to form a coating film, a photomask is placed on the coating film, image exposure and development are performed via the photomask, and light curing is performed as needed.

[0130] The substrate is not particularly limited, but as an example, the substrate is a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, a polyimide substrate, an aluminum substrate, a printed wiring substrate, an array substrate, or the like.

[0131] As the method for applying, drying, exposing and developing the resist composition, a known method can be appropriately selected.

[0132] If an example is given, the coating method of the resist composition is screen printing, roller coating, curtain coating, spray coating, spin coating, etc. In addition, after the resist composition is applied, heating devices such as a circulation oven, an infrared heater, a hot plate, etc. can be used to heat as needed to volatilize the solvent contained in the resin layer. The heating conditions can be appropriately set according to the composition of the resist composition used. Generally speaking, the heating conditions are a temperature of 50°C to 120°C and 30 seconds to 30 minutes.

[0133] The thickness of the coating (after drying) is not particularly limited. If an example is given, the thickness of the coating is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm, and further preferably 1 to 4 μm. When the thickness of the coating is within the above range, the obtained black matrix is ​​easy to appropriately develop a specified pattern and easy to display a specified optical density.

[0134] The exposure method is not particularly limited. As an example, the exposure method is irradiation with active energy rays such as ultraviolet rays and excimer lasers. The energy ray dose can be appropriately set according to the composition of the resist composition. As an example, the energy ray dose is 30 to 2000 mJ / cm 2 The light source used for exposure is not particularly limited. As an example, the light source is a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like.

[0135] The alkaline developer used in the development is not particularly limited. As an example, the developer is an aqueous solution of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide, etc.; an aqueous solution of amine compounds such as ethylamine, diethylamine, dimethylethanolamine, etc.; an aqueous solution of tetramethylammonium, 3-methyl-4-amino-N,N-diethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfonamidoethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline and their sulfates, hydrochlorides or p-toluenesulfonates, etc. It should be noted that the alkaline developer can also add a defoamer, a surfactant, etc. as needed.

[0136] By performing post-baking after alkali development, curing of the resin can be accelerated. The conditions for post-baking are not particularly limited. As an example, the conditions for post-baking are 80° C. to 250° C. and 10 minutes to 4 hours.

[0137] Above, the black matrix of the present embodiment is obtained using the resist composition comprising the above-mentioned pigment dispersion composition. Therefore, the reflectivity of the black matrix is ​​low, and a high-definition display can be obtained. Therefore, the black matrix is ​​suitable for image display devices, touch panels, etc. using a high-definition display.

[0138] Example

[0139] The present invention will be described in more detail below using examples. The present invention is not limited to these examples. It should be noted that, unless otherwise specified, "%" means "mass %" and "part" means "mass part".

[0140] The raw materials used are shown below.

[0141] <Lactam Black>

[0142] Lactam black: Irgaphor S100CF (manufactured by BASF)

[0143] <Carbon black>

[0144] The carbon black described in the following Table 1 was used.

[0145] Table 1

[0146]

[0147] <Aluminum hydroxide>

[0148] C-302A: Particle size: 2400nm, manufactured by Sumitomo Chemical Co., Ltd.

[0149] <Silica-based particles>

[0150] ATLAS100: polymer / silica composite particles, trimethylsilyl treated, particle size 100nm, BET specific surface area 60m 2 / g, manufactured by Cabot Corporation

[0151] <Pigment dispersing aids containing acidic groups>

[0152] SS5000S: A phthalocyanine pigment derivative with a sulfonic acid group, Solsperse 5000S, manufactured by Lubrizol

[0153] <Pigment dispersants containing basic groups>

[0154] Dispersant 1: Tertiary amine polymer dispersant, amine value of solid content 120 mgKOH / g, Tg72.8℃, weight average molecular weight about 3900, methyl methacrylate / butyl methacrylate / dimethylaminoethyl methacrylate block copolymer

[0155] Dispersant 2: tertiary amine polymer dispersant, solid content amine value 70mgKOH / g, Tg-38.6℃, weight average molecular weight about 7300, methyl methacrylate / butyl methacrylate / dimethylaminoethyl methacrylate block copolymer, containing ether group

[0156] <Alkali-soluble resin>

[0157] ZAH-110: Alkali-soluble acrylic resin, Follett ZAH-110, manufactured by Soken Chemical Co., Ltd., acid value 100 mgKOH / g, weight average molecular weight about 15,000, solid content 35% by mass

[0158] ZCR-1569H: alkali-soluble epoxy acrylate resin, KAYARAD ZCR-1569H, manufactured by Nippon Kayaku Co., Ltd., acid value 98 mgKOH / g, weight average molecular weight about 4500, solid content 70% by mass

[0159] <Photopolymerizable compounds>

[0160] DPHA: Dipentaerythritol hexaacrylate

[0161] <Photopolymerization initiator>

[0162] Irgacure OXE02: Oxime ester photopolymerization initiator, Irgacure OXE02, manufactured by BASF Japan Ltd.

[0163] <Surface modifier>

[0164] MF-554: Megafac F-554, oligomer containing fluorine-containing group and lipophilic group, solid content 100%, manufactured by DIC Corporation

[0165] <Solvent>

[0166] PGMEA: Propylene glycol monomethyl ether acetate

[0167] <Preparation of Pigment Dispersion Composition for Black Matrix>

[0168] (Preparation Examples 1 to 8, Comparative Preparation Examples 1 to 8)

[0169] Various materials were mixed in a manner to form the composition (unit: mass %) of Table 1, and kneaded for one day and night using a bead mill to prepare the pigment dispersion compositions for black matrices of Preparation Examples 1 to 8 and Comparative Preparation Examples 1 to 8. The particle size of the obtained pigment dispersion composition was measured by using Nanotrac (UPA-EX150, manufactured by Nikkiso Co., Ltd.) and by laser diffraction particle size measurement method D10 particle size, D50 particle size, and D90 particle size. The results are shown in Table 2.

[0170] Table 2

[0171]

[0172] <Examples 1 to 8, Comparative Examples 1 to 8>

[0173] (Resist composition for black matrix)

[0174] Various materials were mixed to have the composition (unit: mass %) shown in Table 3, uniformly mixed using a high-speed stirrer, and then filtered through a filter having a pore size of 3 μm to obtain resist compositions for black matrices of Examples 1 to 8 and Comparative Examples 1 to 8.

[0175] Using the obtained resist composition, the change amount of optical density (OD value), 550 nm reflectivity, break point, fine line adhesion, and stability were evaluated by the following methods.

[0176] <OD value (optical density)>

[0177] Each resist composition was spin-coated onto a glass substrate (Eagle XG, manufactured by Corning Inc.) to a film thickness of 1 μm. After pre-baking at 100 °C for 3 minutes, it was exposed using a high-pressure mercury lamp, and then post-baked at 230 °C for 3 hours to obtain a resist pattern formed only by the solid portion. The OD value (optical density) of each solid portion of the obtained resist pattern was measured using a Macbeth densitometer (TD-931, trade name, manufactured by Macbeth Co.). The OD values at 8 positions were measured, corrected using the film thickness and pigment concentration, and the average value of the OD values excluding the maximum and minimum values was taken as the optical density. In addition, the coated film was cut using a cutter, and the film thickness at the OD value measurement point was measured.

[0178] Corrected OD value = Measured OD value × 15.0 / Pigment concentration × 1.0 / Measured film thickness value

[0179] The case where the difference between the OD value after a 1-minute standby time and the OD value after a 10-minute standby time is within -0.30 was defined as qualified.

[0180] <550 nm Reflectance>

[0181] Each of the above resist compositions was spin-coated onto a glass substrate to a film thickness of 1 μm. After pre-baking at 100 °C for 3 minutes, it was exposed using a high-pressure mercury lamp with a UV cumulative light amount of 100 mJ / cm 2 for exposure. Further, it was post-baked at 230 °C for 3 hours to obtain a resist film formed only by the solid portion. The average value of the reflectance (unit: %) at wavelengths from 360 nm to 740 nm on the surface of each solid portion of the obtained resist film was measured using a reflectometer (photal MC-7300:SC, manufactured by Otsuka Electronics Co., Ltd.). The smaller the average value of the reflectance, the more preferable.

[0182] <Break Point and Fine Line Adhesion>

[0183] The resist compositions prepared in each of the examples and comparative examples were spin-coated onto a glass substrate (EAGLE XG) to a film thickness of 1 μm and pre-baked at 100 °C for 3 minutes. Then, for line widths from 1 μm to 100 μm, a photomask with line patterns was used, and exposure was performed using a high-pressure mercury lamp with a UV cumulative light amount of 100 mJ / cm 2 for exposure. Then, the time when the development pattern started to appear during spray development at 23 °C in a 0.05% aqueous potassium hydroxide solution under a pressure of 1 kgf / cm 2 was taken as the break point. In the evaluation of fine line adhesion, development was terminated at 1.3 times the time of the break point. Then, 1 kgf / cm 2The pressure spray water was used for washing, and the size (μm) of the smallest line pattern remaining on the glass substrate was evaluated. The minimum line pattern size of 20 μm or less was considered acceptable.

[0184] <Stability>

[0185] The pigment dispersion composition prepared in each example and comparative example was collected in a glass bottle, tightly plugged and stored at 60° C. for 1 week. Before and after storage, the viscosity at 25° C. was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., model number RE100L), and the viscosity change rate was calculated and evaluated according to the following evaluation criteria.

[0186] Viscosity change rate = [(viscosity after 1 week of storage - viscosity before storage) / (viscosity before storage)]

[0187] Evaluation benchmark

[0188] ○: The viscosity change rate is 10% or less.

[0189] △: The viscosity change rate is more than 10% and less than 20%. ×: The viscosity change rate is more than 20%.

[0190] Table 3

[0191]

[0192] As shown in Tables 2 and 3, the pigment dispersion compositions of Preparation Examples 1 to 8 of the present invention and the resist compositions of Examples 1 to 8 using these pigment dispersion compositions have excellent storage stability. In addition, the decrease in the OD value of the resist composition is suppressed. Furthermore, the obtained resist film has a low reflectivity and excellent fine line adhesion.

Claims

1. A pigment dispersion composition for a black matrix, comprising lactam black, silica particles, a pigment dispersant containing a basic group, and an alkali-soluble resin, The pigment dispersion composition for black matrix satisfies at least one of the following conditions A or B: Condition A: does not contain carbon black, Condition B: Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

2. The pigment dispersion composition for black matrix according to claim 1, wherein The pigment dispersant containing a basic group is an acrylic dispersant.

3. The pigment dispersion composition for black matrix according to claim 2, wherein The acrylic dispersant has a glass transition temperature (Tg) of 10° C. or higher.

4. The pigment dispersion composition for black matrix according to claim 1 or 2, wherein The silica particles are polymer / silicon dioxide composites.

5. The pigment dispersion composition for black matrix according to claim 1 or 2, wherein The alkali-soluble resin is an acrylic resin or an epoxy acrylate resin. 6 . A resist composition for a black matrix, comprising the pigment dispersion composition for a black matrix according to claim 1 . 7 . A black matrix formed from the resist composition for a black matrix according to claim 6 .

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