Pigment dispersion composition for black matrix

Abstract

To provide a pigment dispersion composition for a black matrix which has a high storage stability, can suppress reduction of an OD-value (an optical concentration) in a stand-by time from when a resist is applied to a substrate to when the substrate is pre-baked and which presents an excellent thin line adhesion of an obtained resist film.SOLUTION: The pigment dispersion composition for a black matrix includes a lactam black, silica-based particles, a basic group-containing pigment dispersant, and an alkaline soluble resin, and satisfies at least one of the following conditions A and B: the condition A is that carbon black is not included; and the condition B is that carbon black is included and the average primary particle diameter of the carbon black is at least 30 nm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a pigment dispersion composition for black matrices. More specifically, the present invention relates to a pigment dispersion composition for black matrices that has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between resist application to a substrate and pre-baking, and provides a resist film with excellent fine line adhesion. [Background technology]

[0002] Conventionally, in flexible displays and the like, color filters are used to prevent reflection, instead of circularly polarizing plates used for the purpose. Black partition wall materials used in color filters are required to have a lower reflectance than conventional materials. A pigment dispersion composition for a black matrix to obtain such a black partition wall material contains lactam black and carbon black as colorants (see Patent Document 1). Meanwhile, in order to make the production of black matrices more efficient, panel manufacturers do not immediately prebake a glass substrate coated with a resist, but instead adopt a process of prebaking a plurality of substrates after coating. Therefore, among the plurality of substrates, some are prebaked immediately after coating, and others are prebaked after waiting for about 10 minutes after coating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-177204 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a resist film is prepared using the pigment dispersion composition described in Patent Document 1, the resulting resist film has poor fine line adhesion, making it difficult to obtain a high-definition display. A substrate that is prebaked after a long waiting time after coating with the pigment dispersion composition described in Patent Document 1 has a problem in that the optical density (OD value) is lower than that of a substrate that is prebaked immediately after coating.

[0005] The present invention has been made in consideration of such conventional problems, and has an object to provide a pigment dispersion composition for black matrix which has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between applying a resist to a substrate and pre-baking, and provides a resist film with excellent fine line adhesion. [Means for solving the problem]

[0006] The present inventors have conducted intensive research to solve the above problems, and have found that the above problems can be solved simultaneously by including lactam black, silica-based particles, a basic group-containing pigment dispersant, and an alkali-soluble resin, and not including carbon black or including carbon black with a specified average primary particle size, and have thus completed the present invention. The present invention, which solves the above problems, mainly comprises the following features.

[0007] (1) A pigment dispersion composition for black matrix, comprising lactam black, silica-based particles, a basic group-containing pigment dispersant, and an alkali-soluble resin, and satisfying at least one of the following conditions A and B: (Condition A) Contains no carbon black. (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0008] According to such a configuration, the pigment dispersion composition for black matrix has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between applying the resist to the substrate and pre-baking, and provides the resulting resist film with excellent fine line adhesion.

[0009] (2) The pigment dispersion composition for black matrix according to (1), wherein the basic group-containing pigment dispersant is an acrylic dispersant.

[0010] According to such a configuration, the pigment dispersion composition for black matrix can provide a high-definition display.

[0011] (3) The pigment dispersion composition for black matrix according to (2), wherein the glass transition temperature (Tg) of the acrylic dispersant is 10° C. or higher.

[0012] According to such a constitution, the pigment dispersion composition for black matrix provides a resist film having superior fine line adhesion.

[0013] (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.

[0014] According to such a configuration, the pigment dispersion composition for black matrix can provide a display with low reflectance.

[0015] (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.

[0016] According to such a configuration, the pigment dispersion composition for black matrix can provide a high-definition display.

[0017] (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).

[0018] According to this configuration, the black matrix resist composition has excellent storage stability. In addition, the black matrix resist composition can suppress a decrease in OD value (optical density) during the waiting time between resist application to the substrate and pre-baking. The obtained resist film has low reflectance and excellent fine line adhesion, which allows a high-definition display to be obtained.

[0019] (7) A black matrix formed from the resist composition for a black matrix according to (6).

[0020] With such a configuration, the black matrix has low reflectance, and a high-definition display can be obtained. Effect of the Invention

[0021] According to the present invention, it is possible to provide a pigment dispersion composition for black matrix which has excellent storage stability, can suppress a decrease in OD value (optical density) during the waiting time between applying a resist to a substrate and pre-baking, and provides the resulting resist film with excellent fine line adhesion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] <Pigment dispersion composition for black matrix> A pigment dispersion composition for black matrix (hereinafter also referred to as pigment dispersion composition) according to one embodiment of the present invention contains lactam black, silica-based 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 and B. Each of these will be described below. (Condition A) Contains no carbon black. (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0023] (Lactam Black) The lactam black may be any known lactam black. As an example, the lactam black of the present embodiment has the following main skeleton, and more specifically, is Irgaphor Black S 0100 CF (manufactured by BASF) or the like. When the lactam black has the following main skeleton, the hydrogen atoms in the main skeleton may be appropriately substituted with low molecular weight functional groups (for example, hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, acidic groups such as carboxyl groups, sulfonic acid groups, and phosphonic acid groups, basic groups such as amino groups, hydroxyl groups, etc.) or halogen atoms.

[0024] [ka]

[0025] The volume-based particle size D50 value of the lactam black of this embodiment is preferably 70 nm or more, more preferably 85 nm or more. The D50 value is preferably 130 nm or less, more preferably 115 nm or less. By the D50 value being within the above range, the pigment in the obtained pigment dispersion composition is less likely to settle, and has good storage stability. In addition, the pigment dispersion composition provides the obtained resist film with good linearity and roughness.

[0026] The volumetric particle size D90 value of lactam black is preferably 160 nm or more, more preferably 180 nm or more. The D90 value is preferably 300 nm or less, more preferably 280 nm or less. By having the D90 value within the above range, the pigment in the resulting pigment dispersion composition is less likely to settle, and storage stability is good. In addition, the pigment dispersion composition provides a resist film with good linearity and roughness.

[0027] In this 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.).

[0028] The content of lactam black is not particularly limited. For 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. The content of lactam black is preferably 25% by mass or less, more preferably 20% by mass or less, in the pigment dispersion composition. By the content of lactam black being within the above range, the pigment dispersion composition has good OD value and development adhesion of the obtained resist film.

[0029] (Silica-based particles) The silica-based particles are not particularly limited. For example, the silica-based particles are selected from fumed silica, colloidal silica, polymer / silica composites, and the like. In this embodiment, the silica-based particles are blended to reduce the reflectance of the resulting resist film. The silica-based particles may have a trimethylsilyl-treated surface.

[0030] The silica-based particles preferably contain a polymer / silica composite. The polymer / silica composite is a composite particle of an organic polymer particle and a silica particle. In this embodiment, the pigment dispersion composition contains a polymer / silica composite, so that a display having a low reflectance can be easily obtained.

[0031] The particle diameter of the silica-based particles is preferably 5 nm or more, more preferably 10 nm or more. The average primary particle diameter of the silica-based particles is preferably 200 nm or less, more preferably 150 nm or less. When the particle diameter is within the above range, the pigment in the black matrix resist composition obtained from the pigment dispersion composition is less likely to settle, and has excellent storage stability. In this embodiment, the particle diameter is calculated by calculating the arithmetic mean diameter value by electron microscope observation, or in the case of a commercially available product, the catalog value can be used as a reference.

[0032] The BET specific surface area of ​​silica particles is 10m 2 / g or more, and 2 / g or more. The BET specific surface area is preferably 200 m 2 / g or less, and 2 / g or less is more preferable. By having the BET specific surface area within the above range, the reflectance of the obtained resist film is easily reduced. In this embodiment, the BET specific surface area is measured by a method such as JIS Z8830:2013, or in the case of a commercially available product, the catalog value can be used as a reference.

[0033] (Basic group-containing pigment dispersant) The basic group-containing pigment dispersant is not particularly limited. For example, the basic group-containing pigment dispersant is an acrylic dispersant, a urethane dispersant, or the like. Among these, the basic group-containing pigment dispersant is preferably an acrylic dispersant. This makes it easier to obtain a high-definition display with the pigment dispersion composition.

[0034] Acrylic dispersant The acrylic dispersant includes a block copolymer (acrylic block copolymer). The acrylic block copolymer is not particularly limited. For example, the acrylic block copolymer is an acrylic block copolymer that includes an amine compound as a monomer.

[0035] The types of blocks constituting the acrylic block copolymer containing a monomer that is an amine compound may be two or three or more, of which at least one type of block is a block containing a monomer that is an amine compound and has a radically polymerizable unsaturated bond.

[0036] The monomer constituting this block is an acyclic amine compound, a heterocyclic amine compound, or a quaternary ammonium cationic compound, and is preferably an acyclic amine compound such as dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, or dimethylaminobutyl (meth)acrylate, a heterocyclic amine compound such as vinylpyridine or pentamethylpiperidinyl (meth)acrylate, or a quaternary ammonium cationic compound such as a compound obtained by quaternizing and cationicizing dimethylaminopropyl (meth)acrylate with benzyl chloride. A block consisting of one of these monomers may be used, or a block consisting of two or more monomers randomly polymerized, or a block consisting of two or more monomers block polymerized. In addition, a structure consisting of a block of pentamethylpiperidinyl methacrylate and / or dimethylaminopropyl acrylate and a block consisting of another polymerizable ethylenically unsaturated monomer is particularly preferred.

[0037] The other polymerizable block copolymerized with the block derived from the monomer that is an amine compound may be a block composed of one type of monomer, or may be a block in which two or more types of monomers are randomly polymerized. It is preferable that the block does not have a unit derived from a monomer containing an amino group or a pyridine ring. It is more preferable that the block does not have a carboxylic acid group, a hydroxyl group, a thiol group, or a group containing sulfur or phosphorus. The block composed of the other polymerizable ethylenically unsaturated monomer may be one type, or may be two types.

[0038] Other polymerizable ethylenically unsaturated monomers include copolymers with at least one ethylenically unsaturated monomer selected from the group consisting of alkyl (meth)acrylates 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, and glycerol (meth)acrylates such as glycerol monoacrylate, N-phenylmaleimide, polystyrene macromonomer, polymethyl methacrylate macromonomer, and carboepoxy diacrylate. However, it is preferable not to use N-vinylpyrrolidone and sulfur-containing monomers.

[0039] As the block copolymer, a block resin synthesized by living radical polymerization or anionic polymerization can be used.

[0040] The amine value of the acrylic dispersant is preferably greater than 0 mgKOH / g and equal to or less than 140 mgKOH / g.

[0041] The glass transition temperature (Tg) of the acrylic dispersant is not particularly limited. For example, the Tg is preferably 10° C. or higher, more preferably 20° C. or higher. When the Tg of the acrylic dispersant is within the above range, the pigment dispersion composition provides the resulting resist film with better fine line adhesion.

[0042] The content of the acrylic dispersant is not particularly limited. For 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. 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. By having the content of the acrylic dispersant within the above range, the pigment dispersion composition has excellent dispersion stability.

[0043] · Urethane-based dispersants The urethane-based dispersant can be obtained by reacting the isocyanate group of a polyisocyanate compound with 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 basic group-containing compound having a functional group capable of reacting with the isocyanate group in the molecule. The method for obtaining such a urethane-based dispersant can be the method described in JP-A-60-166318.

[0044] The polyisocyanate compound constituting the urethane-based dispersant can be an isocyanate compound having two or more isocyanate groups. For example, the isocyanate compound having two or more isocyanate groups can be 2,4-tolylene diisocyanate, a dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, or other aromatic diisocyanate compounds; hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylene ... Aliphatic or alicyclic polyisocyanates such as ethylenebis(cyclohexylisocyanate), methylcyclohexane-2,4 (or 2,6) diisocyanate, 1,3-(isocyanatomethylene)cyclohexane, etc.; polyisocyanates having an isocyanuric group based on diisocyanates (such as polyisocyanates having an isocyanuric group formed by trimerization of diisocyanates), polyisocyanates obtained by reacting polyols with diisocyanates, 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 tolylene diisocyanate, isophorone diisocyanate, etc.

[0045] The compounds that constitute the urethane-based dispersant and have one or more hydroxy groups in the molecule include polyether compounds, polyester compounds, and the like.

[0046] The polyether compounds include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polytetramethylene glycol; alkylene glycols such as ethylene glycol, propanediol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, ditrimethylolpropane, and dipentaerythritol; and ethylene oxide-modified, propylene oxide-modified, butylene oxide-modified, and tetrahydrofuran-modified products of low molecular weight monools such as methanol and ethanol.

[0047] Examples of the polyester compound include alkylene glycols such as ethylene glycol, propanediol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, diglycerin, ditrimethylolpropane, and dipentaerythritol; low molecular weight monools such as methanol and ethanol; ε-caprolactone-modified products, γ-butyrolactone-modified products, δ-valerolactone-modified products, and methylvalerolactone-modified products; and esterification of aliphatic dicarboxylic acids such as adipic acid and dimer acid with polyols such as neopentyl glycol and methylpentanediol. polyester polyols such as aromatic polyester polyols which are esters of aromatic dicarboxylic acids such as terephthalic acid with polyols such as neopentyl glycol; esters of polyvalent hydroxyl group compounds such as polycarbonate polyols, acrylic polyols, and polytetramethylene hexaglyceryl ether (tetrahydrofuran modified hexaglycerin) with dicarboxylic acids such as fumaric acid, phthalic acid, isophthalic acid, itaconic acid, adipic acid, sebacic acid, and maleic acid; and polyvalent hydroxyl group-containing compounds such as monoglycerides obtained by transesterification of polyvalent hydroxyl group-containing compounds such as glycerin with fatty acid esters. The compound having one or more hydroxyl groups in the molecule is preferably an ε-caprolactone adduct of alcohols.

[0048] The number average molecular weight of the compound having one or more hydroxy groups in the molecule is preferably 300 to 10,000, and more preferably 300 to 6000. The number average molecular weight can be measured by column chromatography.

[0049] The basic group-containing compound having a functional group capable of reacting with an isocyanate group in the molecule constituting the urethane-based dispersant is not particularly limited.As an example, the basic group-containing compound having a functional group capable of reacting with an isocyanate group in the molecule constituting the urethane-based dispersant is at least one compound selected from the group consisting of polyols, polythiols and amines having N,N-disubstituted amino groups or heterocyclic nitrogen atoms.These compounds have Zerewitinoff active hydrogen atoms and at least one nitrogen atom-containing basic group. Such compounds are N,N-dimethyl-1,3-propanediamine, N,N-diethyl-1,4-butanediamine, 2-dimethylaminoethanol, 1-(2-aminoethyl)-piperazine, 2-(1-pyrrolidyl)-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, etc., and amines having a heterocyclic nitrogen atom are preferred.

[0050] The reaction in the synthesis of the urethane-based dispersant is not particularly limited. The amine value of the urethane-based dispersant is preferably more than 0 mgKOH / g and not more than 40 mgKOH / g.

[0051] Commercially available urethane dispersants include Disperbyk (registered trademark)-161 (amine value 11 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-162 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-167 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-182 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-2163 (amine value 10 mgKOH / g, manufactured by BYK), and Disperbyk (registered trademark)-2164 (amine value 14 mgKOH / g, manufactured by BYK).

[0052] The content of the urethane-based dispersant is not particularly limited. For example, the content of the urethane-based dispersant in the pigment dispersion composition is preferably 0.5% by mass or more, more preferably 1.0% by mass or more. The content of the urethane-based dispersant in the pigment dispersion composition is preferably 30.0% by mass or less, more preferably 25.0% by mass or less. By having the content of the urethane-based dispersant within the above range, the pigment dispersion composition has excellent dispersion stability.

[0053] (alkali soluble resin) By including an alkali-soluble resin, the dispersion liquid can be developed with an alkali developer, and a pattern such as a partition wall can be formed. The alkali-soluble resin is not particularly limited. For example, the alkali-soluble resin is an acrylic resin, an epoxy acrylate resin, a urethane acrylate resin, or the like. Among these, the alkali-soluble resin is preferably an acrylic resin or an epoxy acrylate resin. This makes it easier to obtain a high-definition display with the pigment dispersion composition.

[0054] The alkali-soluble resin is not particularly limited. For example, the alkali-soluble resin may be a resin containing an anionic group such as a carboxyl group, a sulfonic acid group, or a phosphonic acid group (-P(=O)(OH2)).

[0055] The acrylic resin is not particularly limited. Examples of the acrylic resin include the "Follet" series manufactured by Soken Chemical & Engineering Co., Ltd., ZAH-106, ZAH-110, ZAH-115, and ZAH-310.

[0056] The epoxy acrylate resin is not particularly limited. For example, the epoxy acrylate resin may be the "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.

[0057] The urethane acrylate resin is not particularly limited. Examples of the urethane acrylate resin include the "KAYARAD" series, UX-3204, UX-4101, UXT-6100, UX-8101, UX-0937, DPHA-40H, and UX-5000 manufactured by Nippon Kayaku Co., Ltd.

[0058] 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 is preferably 300 mgKOH / g or less, more preferably 200 mgKOH / g or less.

[0059] The weight average molecular weight of the alkali-soluble resin is preferably 1,000 or more, more preferably 3,000 or more, from the viewpoint of the formability of the resist film. The weight average molecular weight of the alkali-soluble resin is preferably 100,000 or less, more preferably 50,000 or less, from the viewpoint of increasing the solubility. The weight average molecular weight can be measured by gel permeation chromatography (GPC). As an example, chromatography is performed using a Water2690 (manufactured by Waters) as a GPC device and a PLgel, 5μ, MIXED-D (manufactured by Polymer Laboratories) as a column under the conditions of tetrahydrofuran as a developing solvent, a column temperature of 25°C, a flow rate of 1 milliliter / minute, an RI detector, a sample injection concentration of 10 milligrams / milliliter, and an injection amount of 100 microliters, and the weight average molecular weight can be calculated as a polystyrene-equivalent weight average molecular weight.

[0060] The alkali-soluble resin is an acrylic copolymer resin, a maleic acid copolymer resin, a polyester resin obtained by a condensation polymerization reaction, an epoxy acrylate resin obtained by an addition polymerization reaction of acrylic acid and an epoxy compound, a urethane acrylate resin obtained by a polymerization reaction of acrylic acid, a polyol and an isocyanate compound, etc. Among these, the alkali-soluble resin is preferably an acrylic copolymer resin or an epoxy acrylate resin from the viewpoint of excellent developability and fine line adhesion.

[0061] The content of the alkali-soluble resin is not particularly limited. For example, the content of the alkali-soluble resin is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, based on 100 parts by mass of the total of the components blended as pigments. The content of the alkali-soluble resin is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, based on 100 parts by mass of the total of the components blended as pigments. Here, the components blended as pigments include lactam black, carbon black, and aluminum hydroxide, an optional component described later.

[0062] (Pigment dispersing aid having an acidic group) The pigment dispersion composition of the present embodiment preferably contains a pigment dispersion aid having an acidic group for the purpose of further improving the dispersibility of the pigment. The pigment dispersion aid having an acidic group is a compound (a dye derivative having an acidic group) in which an acidic group such as a carboxyl group or a sulfonic acid group is introduced into a dye such as a perylene compound, a diketopyrrolopyrrole compound, an azonaphthol compound, a dioxazine compound, a quinacridone compound, a phthalocyanine compound and a metal complex thereof, an anthraquinone, a naphthalene, an acridone, or a triazine, or a compound obtained by neutralizing the above with an organic amine or the like. The dye derivative having an acidic group is preferably a phthalocyanine dye derivative having a sulfonic acid group, in view of the good dispersibility of lactam black and carbon black described later.

[0063] The amount of the pigment dispersion aid having an acidic group is preferably 0.1 to 20 parts by mass, and more preferably 0.2 to 10 parts by mass, based on 100 parts by mass of lactam black.

[0064] (Carbon Black) The pigment dispersion composition of the present embodiment is characterized in that it satisfies at least one of the following conditions A and B in relation to the presence or absence and type of carbon black. (Condition A) Contains no carbon black. (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

[0065] Regarding condition A Condition A specifies that the pigment dispersion composition does not contain carbon black. Even if the pigment dispersion composition that satisfies condition A does not contain carbon black, the resulting black matrix resist composition has excellent storage stability. In addition, the resulting black matrix resist composition can suppress a decrease in OD value (optical density) during the waiting time between resist application to the substrate and pre-baking. Furthermore, the resulting resist film has low reflectance, and an extremely high-definition display can be obtained.

[0066] ·Condition B Condition B specifies that carbon black is contained and that the average primary particle size of the carbon black is 30 nm or more.

[0067] The carbon black is not particularly limited except that it has an average primary particle size of 30 nm or more. For example, the carbon black may be neutral carbon black, acidic carbon black, or the like.

[0068] The pH of the neutral carbon black is preferably in the range of 8-10.

[0069] The acidic carbon black preferably has a pH in the range of 2-4.

[0070] In this embodiment, the pH can be a catalog value in the case of commercially available carbon black, and when measuring, 1 g of carbon black is added to 20 mL of distilled water (pH 7.0) without carbon dioxide and mixed with a magnetic stirrer to prepare an aqueous suspension, and the pH can be measured at 25°C using a glass electrode (German Industrial Standard DIN ISO 787 / 9). In this embodiment, the average primary particle size is the arithmetic mean diameter value obtained by observation with an electron microscope, or in the case of commercially available carbon black, a catalog value can be used.

[0071] The average primary particle size of the carbon black is preferably 30 nm or more, and more preferably 31 nm or more. When the average primary particle size of the carbon black is 30 nm or more, the pigment dispersion composition provides the resulting resist film with good fine line adhesion.

[0072] The specific surface area of ​​carbon black is 64m 2 / g, and preferably less than 60m 2 When the specific surface area of ​​the carbon black is within the above range, the pigment dispersion composition provides a resist film with good fine line adhesion.

[0073] The content of carbon black is not particularly limited. For example, the content of carbon black in the pigment dispersion composition is preferably 1% by mass or more, more preferably 5% by mass or more. The content of carbon black in the pigment dispersion composition is preferably 35% by mass or less, more preferably 30% by mass or less. By having the carbon black content within the above range, the pigment dispersion composition has excellent dispersibility of carbon black and excellent light blocking properties when a black matrix is ​​formed.

[0074] The pigment dispersion composition that satisfies the condition B has excellent storage stability in the resulting black matrix resist composition. In addition, the resulting black matrix resist composition can suppress a decrease in OD value (optical density) during the waiting time between resist application to the substrate and pre-baking. Furthermore, the resulting resist film has low reflectance, and a high-definition display can be obtained.

[0075] (solvent) The pigment dispersion composition of the present embodiment may contain a solvent. The solvent is not particularly limited. For example, the solvent is preferably an ester-based solvent, an ether-based solvent, an ether ester-based solvent, a ketone-based solvent, an aromatic hydrocarbon-based solvent, a nitrogen-containing solvent, or the like, from the viewpoint of stably dispersing lactam black and sufficiently dissolving an alkali-soluble resin or the like.

[0076] Examples of ester-based 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, hydroxyacetic acid esters, and n-amyl formate.

[0077] Examples of the ether solvent 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.

[0078] Examples of the ether ester solvent include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate.

[0079] The ketone solvents include methyl isobutyl ketone, cyclohexanone, 2-heptanone, δ-butyrolactone, and the like.

[0080] The aromatic hydrocarbon solvents include toluene, xylene, and alkylnaphthalenes.

[0081] Nitrogen-containing solvents include N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0082] When a solvent is contained, the content of the solvent is not particularly limited. For example, the content of the solvent in the pigment dispersion composition is preferably 40% by mass or more, more preferably 50% by mass or more. The content of the solvent in the pigment dispersion composition is preferably 90% by mass or less, more preferably 80% by mass or less. By having the content of the solvent within the above range, the pigment dispersion composition has excellent dispersion stability of lactam black.

[0083] (Aluminum Hydroxide) The pigment dispersion composition of this embodiment preferably contains aluminum hydroxide, because this improves the fine line adhesion of the resulting resist film.

[0084] When aluminum hydroxide is contained, the content of aluminum hydroxide is not particularly limited. For example, the content of aluminum hydroxide in the pigment dispersion composition is preferably 0.1% by mass or more, more preferably 0.2% by mass or more. The content of aluminum hydroxide in the pigment dispersion composition is preferably 5% by mass or less, more preferably 3% by mass or less. By having the content of aluminum hydroxide within the above range, the pigment dispersion composition has good storage stability and the resulting resist film has good fine line adhesion.

[0085] Returning to the description of the pigment dispersion composition as a whole, 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.

[0086] The black matrix resist composition obtained by using the pigment dispersion composition of this embodiment has excellent storage stability. In addition, the obtained black matrix resist composition can suppress the decrease in OD value (optical density) during the waiting time between resist application to the substrate and pre-baking. The obtained resist film has low reflectance, and a high-definition display can be obtained.

[0087] <Resist composition for black matrix> A resist composition for a black matrix (hereinafter also referred to as a resist composition) according to one embodiment of the present invention contains the above-mentioned pigment dispersion composition for a black matrix.

[0088] The content of the pigment dispersion composition in the resist composition is not particularly limited. For example, the content of the pigment dispersion composition is preferably 27% by mass or more, more preferably 30% by mass or more. The content of the pigment dispersion composition is preferably 40% by mass or less, more preferably 37% by mass or less. By having the content of the pigment dispersion composition within the above range, it is easy to achieve both fine line adhesion and OD value.

[0089] The resist composition of the present embodiment may contain, in addition to the pigment dispersion composition, any optional components that are conventionally blended in resist compositions. For example, the resist composition may contain an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, a surface modifier, a solvent, etc.

[0090] (alkali soluble resin) The alkali-soluble resin is preferably blended to improve the developability with an alkali developer. The alkali-soluble resin is not particularly limited, and may contain, for example, the alkali-soluble resin described above in relation to the pigment dispersion composition. Among these, the alkali-soluble resin is preferably an acrylic copolymer resin or an epoxy acrylate resin, from the viewpoint of excellent developability and fine line adhesion.

[0091] When an alkali-soluble resin is included, the content of the alkali-soluble resin is not particularly limited. For example, the content of the alkali-soluble resin in the resist composition is preferably 3% by mass or more, more preferably 5% by mass or more. The content of the alkali-soluble resin in the resist composition is preferably 15% by mass or less, more preferably 12% by mass or less. By having the content of the alkali-soluble resin within the above range, the resist composition has an appropriate range of developability with an alkaline developer.

[0092] (Photopolymerizable compound) The photopolymerizable compound is not particularly limited, and may be, for example, a monomer or oligomer having a photopolymerizable unsaturated bond.

[0093] Examples of the monomer having one photopolymerizable unsaturated bond include alkyl methacrylates or acrylates such as methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; aralkyl methacrylates or acrylates such as benzyl methacrylate and benzyl acrylate; alkoxyalkyl methacrylates or acrylates such as butoxyethyl methacrylate and butoxyethyl acrylate; and aminoalkyl methacrylates such as N,N-dimethylaminoethyl methacrylate and N,N-dimethylaminoethyl acrylate. Methacrylates or acrylates; methacrylic acid esters or acrylic acid esters of polyalkylene glycol monoalkyl ethers such as diethylene glycol monoethyl ether, triethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, etc.; methacrylic acid esters or acrylic acid esters of polyalkylene glycol monoaryl ethers such as hexaethylene glycol monophenyl ether, etc.; isobornyl methacrylate or acrylate; glycerol methacrylate or acrylate; 2-hydroxyethyl methacrylate or acrylate, etc.

[0094] Monomers having two or more photopolymerizable unsaturated bonds include bisphenol A dimethacrylate, 1,4-butanediol 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, dipentaerythritol hexameth ... Examples of such acrylates include erythritol pentamethacrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol 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, and dipentaerythritol pentaacrylate.

[0095] The oligomer having a photopolymerizable unsaturated bond is, for example, one obtained by appropriately polymerizing the above-mentioned monomers.

[0096] When the photopolymerizable compound is included, the content of the photopolymerizable compound is not particularly limited. For example, the content of the photopolymerizable compound in the resist composition is preferably 1% by mass or more, more preferably 2.5% by mass or more. The content of the photopolymerizable compound in the resist composition is preferably 15% by mass or less, more preferably 10% by mass or less. By having the content of the photopolymerizable compound within the above range, the resist composition can achieve both the curability of the resist film and the alkaline developability.

[0097] (Photopolymerization initiator) The photopolymerization initiator is not particularly limited. For example, the photopolymerization initiator may be 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-hydroxyisobutylphenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, triazine-based photopolymerization initiator, oxime ester-based photopolymerization initiator, etc.

[0098] When a photopolymerization initiator is included, the content of the photopolymerization initiator is not particularly limited. For example, the content of the photopolymerization initiator in the resist composition is preferably 0.1% by mass or more, and more preferably 0.3% by mass or more. The content of the photopolymerization initiator in the resist composition is preferably 5% by mass or less, and more preferably 2% by mass or less. By having the content of the photopolymerization initiator within the above range, the resist composition can achieve both the curability of the resist film and fine line adhesion.

[0099] Furthermore, additives such as a leveling agent, an antioxidant, and a defoaming agent may be added to the resist composition as necessary.

[0100] There are no particular limitations on the method for preparing the resist composition of this embodiment. As one example, the resist composition can be prepared by stirring and mixing various materials using a stirring device or the like.

[0101] The resist composition of the present embodiment has excellent storage stability. In addition, the resist composition can suppress a decrease in OD value (optical density) during the waiting time between resist application to a substrate and pre-baking. The obtained resist film has low reflectance and excellent fine line adhesion, which allows a high-definition display to be obtained.

[0102] <Black matrix> The black matrix according to one embodiment of the present invention is a black matrix formed from the above-mentioned resist composition.

[0103] The method for forming the black matrix is ​​not particularly limited. For example, the method for forming the black matrix is ​​a method in which the resist composition for a black matrix of the above embodiment is applied onto a substrate, dried to form a coating film, a photomask is placed on the coating film, and image exposure through the photomask, development, and photocuring as necessary are performed.

[0104] The substrate is not particularly limited, and examples thereof include 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, and an array substrate.

[0105] The methods for applying the resist composition, drying, exposing and developing it can be appropriately selected from known methods.

[0106] For example, the resist composition can be applied by screen printing, roll coating, curtain coating, spray coating, spin coating, etc. After application of the resist composition, the solvent contained in the resin layer can be volatilized by heating using a heating means such as a circulation oven, an infrared heater, or a hot plate, if necessary. The heating conditions can be appropriately set according to the composition of the resist composition used. In general, the heating conditions are a temperature of 50°C to 120°C and a time of 30 seconds to 30 minutes.

[0107] The thickness of the coating film (after drying) is not particularly limited. For example, the thickness of the coating film is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm, and even more preferably 1 to 4 μm. When the thickness of the coating film is within the above range, the obtained black matrix is ​​likely to be favorably developed into a predetermined pattern and to exhibit a predetermined optical density.

[0108] The exposure method is not particularly limited. For example, the exposure method is irradiation with active energy rays such as ultraviolet rays and excimer laser light. The amount of energy radiation may be appropriately set depending on the composition of the resist composition. For example, the energy dye may be irradiated with an energy of 30 to 2000 mJ / cm. 2 The light source used for exposure is not particularly limited. Examples of the light source include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, and a metal halide lamp.

[0109] The alkaline developer used for development is not particularly limited. For example, the developer may be 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 p-phenylenediamine compounds such as 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 sulfates, hydrochlorides, or p-toluenesulfonates thereof. In addition, the alkaline developer may contain an antifoaming agent, a surfactant, etc., as necessary.

[0110] After the alkaline development, the resin can be hardened by post-baking. The post-baking conditions are not particularly limited. For example, the post-baking conditions are a temperature of 80° C. to 250° C. and a time of 10 minutes to 4 hours.

[0111] As described above, the black matrix of the present embodiment is obtained by using a resist composition containing the above-mentioned pigment dispersion composition. Therefore, the black matrix has a low reflectance and can provide a high-definition display. Therefore, the black matrix is ​​suitable for use in image display devices and touch panels that use high-definition displays. EXAMPLES

[0112] The present invention will be described in more detail below with reference to the following examples. The present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass".

[0113] The raw materials used are shown below. <Lactam Black> Lactam black: Irgaphor S0100CF (BASF) <Carbon black> The carbon blacks used were those listed in Table 1 below.

[0114] [Table 1]

[0115] <Aluminum hydroxide> C-302A: Particle size: 2,400 nm, manufactured by Sumitomo Chemical Co., Ltd. <Silica-based particles> ATLAS100: Polymer / silica composite particles, trimethylsilyl treatment, particle size 100 nm, BET specific surface area 60 m 2 / g, manufactured by Cabot Corporation <Acidic group-containing pigment dispersing agent> SS5000S: Phthalocyanine dye derivative with sulfonic acid group, Solsperse 5000S, manufactured by Lubrizol <Basic group-containing pigment dispersant> Dispersant 1: Tertiary amine polymer dispersant, amine value of solids 120mgKOH / g, Tg72.8℃, weight average molecular weight approx. 3,900, methyl methacrylate / butyl methacrylate / dimethylaminoethyl methacrylate block copolymer Dispersant 2: Tertiary amine polymer dispersant, amine value of solids 70 mg KOH / g, Tg-38.6°C, weight average molecular weight approximately 7,300, methyl methacrylate / butyl methacrylate / dimethylaminoethyl methacrylate block copolymer, containing ether groups <Alkali-soluble resin> ZAH-110: Alkali-soluble acrylic resin, Foret ZAH-110, manufactured by Soken Chemical & Engineering Co., Ltd., acid value 100 mg KOH / g, weight average molecular weight approximately 15,000, solid content 35% by mass ZCR-1569H: Alkali-soluble epoxy acrylate resin, KAYARAD ZCR-1569H, manufactured by Nippon Kayaku Co., Ltd., acid value 98 mg KOH / g, weight average molecular weight approximately 4,500, solid content 70% by mass <Photopolymerizable compound> DPHA: Dipentaerythritol hexaacrylate <Photopolymerization initiator> IRGACURE OXE02: Oxime ester photoinitiator, IRGACURE OXE02, manufactured by BASF Japan Ltd. <Surface modifier> MF-554: Megafac F-554, fluorine-containing and lipophilic group-containing oligomer, solid content 100%, manufactured by DIC Corporation <Solvent> PGMEA: Propylene glycol monomethyl ether acetate

[0116] <Preparation of Pigment Dispersion Composition for Black Matrix> (Preparation Examples 1 to 8, Comparative Preparation Examples 1 to 8) Various materials were mixed so as to have the compositions shown in Table 1 (unit: mass %), kneaded with a bead mill for 24 hours, and pigment dispersion compositions for black matrices of Preparation Examples 1 to 8 and Comparative Preparation Examples 1 to 8 were prepared. The particle diameters of the obtained pigment dispersion compositions were measured for the D10 particle diameter, D50 particle diameter, and D90 particle diameter by laser diffraction particle size analysis using a nanotrack (UPA-EX150, manufactured by Nikkiso Co., Ltd.). The results are shown in Table 2.

[0117]

Table 2

[0118] <Examples 1 to 8, Comparative Examples 1 to 8> (Resist Composition for Black Matrix) Various materials were mixed so as to have the compositions shown in Table 3 (unit: mass %), uniformly mixed using a high-speed stirrer, and then filtered through a filter with a pore diameter of 3 μm to obtain resist compositions for black matrices of Examples 1 to 8 and Comparative Examples 1 to 8.

[0119] Using the obtained resist compositions, the change amount of optical density (OD value), 550 nm reflectance, breakpoint, fine line adhesion, and stability were evaluated by the following method. The results are shown in Table 3.

[0120] <OD Value (Optical Density)> Each resist composition was applied onto a glass substrate (manufactured by Corning, Inc., Eagle XG) with a spin coater to a film thickness of 1 μm, pre-baked at 100 °C for 3 minutes, exposed with a high-pressure mercury lamp, and further post-baked at 230 °C for 3 hours to obtain a resist pattern formed only in the solid portions. The OD value (optical density) of each solid portion resist pattern obtained was measured with a Macbeth densitometer (TD-931, trade name, manufactured by Macbeth). The OD value was measured at 8 locations, corrected by the film thickness and pigment concentration, and the average value of the OD values excluding the maximum value and the minimum value was taken as the optical density. Also, the coating film was scraped with a cutter knife, and the film thickness at the OD value measurement points was measured. Corrected OD value = Measured OD value × 15.0 / Pigment concentration × 1.0 / Measured film thickness value A sample was deemed to have passed if the difference between the OD value after 1 minute of waiting time and the OD value after 10 minutes of waiting time was within -0.30. <550nm reflectance> Each of the above resist compositions was applied to a glass substrate using a spin coater to a thickness of 1 μm, prebaked at 100° C. for 3 minutes, and then exposed to a UV light intensity of 100 mJ / cm using a high-pressure mercury lamp. 2 The resist film was exposed to light at 400° C. for 3 hours. The resist film was then post-baked at 230° C. for 3 hours to obtain a resist film formed only in the solid areas. The average reflectance (unit: %) of the resist film surface in each of the obtained solid areas at wavelengths of 360 nm to 740 nm was measured using a reflectometer (Otsuka Electronics Co., Ltd., Photal MC-7300:SC). The smaller the average reflectance, the more preferable it is. <Breakpoint and fine line adhesion> The resist compositions prepared in each of the Examples and Comparative Examples were applied to a glass substrate (EAGLE XG) using a spin coater to a film thickness of 1 μm, and prebaked at 100° C. for 3 minutes. Next, using a photomask having a line pattern with a line width of 1 μm to 100 μm, a high-pressure mercury lamp was used to apply a UV integrated light dose of 100 mJ / cm. 2 After that, the film was exposed to light at 1 kgf / cm in a 0.05% aqueous potassium hydroxide solution at 23°C. 2 The time when the development pattern started to appear in the shower development with a pressure of 1 kgf / cm was taken as the break point. In the evaluation of the fine line adhesion, the development was stopped when the time reached 1.3 times the break point. 2 The glass substrate was then washed with high pressure water spray, and the minimum line pattern size (μm) remaining on the glass substrate was evaluated. A minimum line pattern size of 20 μm or less was deemed to pass. <Stability> The pigment dispersion compositions prepared in each of the Examples and Comparative Examples were placed in glass bottles, sealed, and stored for one week at 60° C. Before and after storage, the viscosity was measured at 25° C. using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., model RE100L) to determine the rate of viscosity change, and evaluated according to the following evaluation criteria. Viscosity change rate = [(viscosity after 1 week of storage - viscosity before storage) / (viscosity before storage)] Evaluation criteria A: The viscosity change rate was 10% or less. Δ: The viscosity change rate was more than 10% and 20% or less. ×: The viscosity change rate exceeded 20%.

[0121] [Table 3]

[0122] 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 them had excellent storage stability. In addition, the resist compositions suppressed the decrease in OD value. Furthermore, the obtained resist films had low reflectance and excellent fine line adhesion.

Claims

1. The pigment dispersion contains lactam black, silica particles, a basic group-containing pigment dispersant, and an alkali-soluble resin, A pigment dispersion composition for a black matrix, which satisfies at least one of the following conditions A and B: (Condition A) No carbon black is contained. (Condition B) Carbon black is contained, and the average primary particle size of the carbon black is 30 nm or more.

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

3. 3. The pigment dispersion composition for black matrices according to claim 2, wherein the glass transition temperature (Tg) of the acrylic dispersant is 10[deg.] C. or higher.

4. 3. The pigment dispersion composition for black matrices according to claim 1, wherein the silica-based particles are a polymer / silica composite.

5. 3. The pigment dispersion composition for a black matrix according to claim 1, 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 or 2.

7. A black matrix formed from the resist composition for a black matrix according to claim 6.

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