Pigment dispersion composition for black matrix, resist composition for black matrix, and black matrix

Abstract

To provide a pigment dispersion composition for a black matrix, capable of forming a black matrix excellent in optical density and resolution.SOLUTION: The pigment dispersion composition for a black matrix contains a black colorant, a pigment dispersant, and a binder resin. The black colorant is carbon black having a pH of 1.0-2.9. The pigment dispersant has an amine value of 5-35 mg KOH / g. The content of potassium ions is 100 ppm or less based on the total solid content.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pigment dispersion composition for a black matrix, a resist composition for a black matrix, and a black matrix. [Background technology]

[0002] In image display devices using liquid crystal or plasma, a light-shielding film (black matrix) is provided in the gaps between colored patterns within the display area of ​​the screen or around the edges of the display area, and in liquid crystal displays using TFT, on the external light side of the TFT. In LCD displays, this mainly prevents light leakage from the backlight, and in plasma displays, this mainly prevents blurring caused by the mixing of various colored lights from appearing on the screen, thereby helping to improve display characteristics (contrast and color purity).

[0003] For example, color filters used to convert white light from the backlight of a liquid crystal display device into colored light are usually manufactured by forming pixels of different hues, red, green, and blue, in succession in a striped or mosaic pattern on the surface of a transparent substrate, such as glass or a plastic sheet, on which a black matrix has been formed.

[0004] Similarly, in touch panels that combine image display devices and position input devices, color filters with black matrices formed as light-shielding films are used, and until now, these have generally been formed on the opposite side of the cover glass from the sensor substrate. However, as demand for lighter touch panels increases, progress is being made in the development of technology that simultaneously forms the light-shielding film and touch sensor on the same side of the cover glass, which will enable even lighter panels.

[0005] As a method for forming such a black matrix, for example, a photolithography method using a pigment (pigment method) is used.

[0006] For example, Patent Document 1 discloses that a black matrix with excellent developability and resolution can be formed using a light-shielding resin composition that contains (A) a binder resin, (B) a monomer, (C) a photopolymerization initiator, and (D) carbon black having an average particle size of 8 nm or more and 65 nm or less and a DBP oil absorption of 90 ml / 100 g or less, and that has a potassium ion content of 20 ppm or less relative to the total solid content.

[0007] However, in recent years, there has been a demand for black matrices with even greater optical density and resolution, and the method described in Patent Document 1 has been insufficient. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-316620 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, an object of the present invention is to provide a pigment dispersion composition for a black matrix that can form a black matrix having excellent optical density and resolution. [Means for solving the problem]

[0010] The present inventors have discovered that, in a pigment dispersion composition for a black matrix containing a black colorant, a pigment dispersant, and a binder resin, by controlling the pH of the black colorant, the amine value of the pigment dispersant, and the potassium ion content relative to the total solids content within specific ranges, a pigment dispersion composition for a black matrix can be obtained that is capable of forming a black matrix with optical density and resolution superior to conventional ones, and have completed the present invention.

[0011] That is, the present invention provides a pigment dispersion composition for black matrices, comprising a black colorant, a pigment dispersant, and a binder resin, wherein the black colorant is carbon black having a pH of 1.0 to 2.9, and the pigment dispersant has an amine value of 5 to 35 mgKOH / g and a potassium ion content of 100 ppm or less relative to the total solid content. In the pigment dispersion composition for black matrix of the present invention, the black colorant preferably has an average particle size of 26 to 65 nm. In the pigment dispersion composition for black matrix of the present invention, the black colorant preferably has a DBP oil absorption of 80 ml / 100 g or less. In the pigment dispersion composition for black matrix of the present invention, the pigment dispersant preferably has an amine value of 5 to 30 mgKOH / g. In the pigment dispersion composition for black matrix of the present invention, the binder resin preferably has one or more structures selected from an epoxy acrylate structure and a cardo structure. Furthermore, the pigment dispersion composition for black matrix of the present invention preferably has a potassium ion content of 90 ppm or less based on the total solid content. The present invention also relates to a resist composition for black matrix obtained from the above-mentioned pigment dispersion composition for black matrix, which has a potassium ion content of 100 ppm or less based on the total solid content. In the black matrix resist composition of the present invention, the potassium ion content is preferably 75 ppm or less relative to the total solid content. The present invention also relates to a black matrix formed from the above-mentioned black matrix resist composition. The present invention also relates to a method for producing a pigment dispersion composition for a black matrix, the method comprising: a washing step of washing a black colorant, which is carbon black having a pH of 1.0 to 2.9, until the potassium ion content is 120 ppm or less; and a mixing and kneading step of mixing and kneading the black colorant, pigment dispersant, and binder resin after the washing step. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a pigment dispersion composition for a black matrix, which is capable of forming a black matrix having excellent optical density and resolution. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Pigment dispersion composition for black matrix> The present invention provides a pigment dispersion composition for a black matrix, comprising a black colorant, a pigment dispersant, and a binder resin, wherein the black colorant has a pH of 1.0 to 2.9, and the pigment dispersant has an amine value of 5 to 35 mgKOH / g and a potassium ion content of 100 ppm or less relative to the total solid content.

[0014] In the present invention, by controlling the potassium ion content in carbon black having a specific pH range, the removal of uncured areas due to potassium ions that previously remained in the coating film formed during development is further suppressed than in the prior art, and it is believed that resolution is improved because fine lines are less likely to be attacked by the alkaline developer. Furthermore, by applying a pigment dispersant having a specific amine value to the above-mentioned carbon black, it is possible to stably disperse the carbon black even at high concentrations, and the viscosity of the pigment dispersion composition for black matrices becomes low, improving coatability. This is thought to have made it possible to form a black matrix with a high concentration of carbon black in the coating film, i.e., with excellent optical density. However, the present invention should not be construed as being limited to the above mechanism.

[0015] (black colorant) The pigment dispersion composition for a black matrix of the present invention contains a black colorant. The black colorant is carbon black having a pH of 1.0 to 2.9. By adjusting the pH of the black colorant to 2.9 or less, a black matrix with excellent resolution can be obtained. The black colorant preferably has a pH of 1.0 to 2.8.

[0016] The pH can be measured at 25°C using a glass electrode after preparing an aqueous suspension by adding 1 g of carbon black to 20 ml of decarbonated distilled water (pH 7.0) and mixing with a magnetic stirrer (German Industrial Standard DIN ISO 787 / 9).

[0017] The carbon black is an acidic carbon black which is a carbonaceous material that is naturally or artificially oxidized and which exhibits acidity when mixed with distilled water and boiled.

[0018] The black colorant preferably has an average primary particle diameter of 26 to 65 nm, and more preferably has an average primary particle diameter of 26 to 45 nm. If the primary particle size of the black colorant is smaller than 26 nm or larger than 65 nm, the storage stability may be poor. The average primary particle size is an arithmetic mean diameter determined by observation with an electron microscope.

[0019] The black colorant preferably has a DBP oil absorption of 80 ml / 100 g or less, more preferably 70 ml / 100 g or less, and even more preferably 60 ml / 100 g or less. When the DBP oil absorption of the black colorant is 80 ml / 100 g or less, the resolution of the black matrix can be suitably imparted.

[0020] The DBP oil absorption indirectly quantifies the structure of carbon black by measuring the void volume, and is a value measured in accordance with JIS K 6217-4. "DBP" is an abbreviation for dibutylphthalate.

[0021] Specific examples of the black colorant include Raven 1080 (pH 2.4, average primary particle size 28 nm, DBP oil absorption 60 ml / 100 g), Raven 1100U (pH 2.9, average primary particle size 32 nm, DBP oil absorption 72 ml / 100 g), and NEROX 305 (pH 2.8, average primary particle size 28 nm, DBP oil absorption 58 ml / 100 g), all manufactured by Columbia Chemicals; and MA14 (pH 2.8, average primary particle size 40 nm, DBP oil absorption 73 ml / 100 g) and MA220 (pH 2.9, average primary particle size 55 nm, DBP oil absorption 93 ml / 100 g), all manufactured by Mitsubishi Chemical Corporation.

[0022] The black colorant preferably has a potassium ion content of 120 ppm or less, more preferably 100 ppm or less, even more preferably 80 ppm or less, and particularly preferably 60 ppm or less. By using such a potassium ion content, the potassium ion content in the pigment dispersion composition for black matrix can be suitably adjusted.

[0023] The potassium ion content in the black colorant can be adjusted by a washing step described below.

[0024] The potassium ion content in the black colorant can be adjusted by repeatedly stirring the black colorant and purified water using a high-speed stirrer and then suction filtering the mixture to wash the mixture.

[0025] The content of the black colorant is preferably 3 to 70 mass %, more preferably 10 to 50 mass %, as a mass fraction relative to the total solid content of the pigment dispersion composition for black matrix of the present invention. If the content of the black colorant is less than 3% by mass, the light blocking properties may be reduced when a black matrix is ​​formed, whereas if it exceeds 70% by mass, it may be difficult to disperse the pigment.

[0026] (pigment dispersant) The pigment dispersion composition for a black matrix of the present invention contains a pigment dispersant, and the pigment dispersant has an amine value of 5 to 35 mgKOH / g. When the amine value of the pigment dispersant is within the above range, the viscosity of the pigment dispersion composition for black matrix can be reduced and the concentration of carbon black in the coating film can be increased, thereby making it possible to obtain a black matrix with excellent resolution. On the other hand, if the amine value of the pigment dispersant is less than 5 mgKOH / g, the pigment dispersion composition for black matrix will suffer from poor dispersion and will become highly viscous. On the other hand, if the amine value of the pigment dispersant is more than 35 mgKOH / g, the viscosity will increase due to a neutralization reaction with the binder resin, which will be described later. The pigment dispersant preferably has an amine value of 5 to 30 mgKOH / g, more preferably 5 to 25 mgKOH / g. The amine value indicates the total amount of free base and base, and is expressed as the number of milligrams of potassium hydroxide equivalent to the amount of hydrochloric acid required to neutralize 1 g of sample.

[0027] The pigment dispersant is a basic group-containing pigment dispersant, and examples of the pigment dispersant that can be used include anionic surfactants, basic group-containing polyester-based pigment dispersants, basic group-containing acrylic-based pigment dispersants, basic group-containing urethane-based pigment dispersants, basic group-containing carbodiimide-based pigment dispersants, and acidic group-containing polymeric pigment dispersants. These basic group-containing pigment dispersants may be used alone or in combination of two or more. Among them, basic group-containing polymeric pigment dispersants are preferred because they provide good pigment dispersibility.

[0028] Specific examples of the basic group-containing polymeric pigment dispersant include: (1) A reaction product of an amino group and / or an imino group of a polyamine compound (e.g., a poly(lower alkylene amine) such as polyallylamine, polyvinylamine, or polyethylene polyimine) with at least one member selected from the group consisting of polyesters, polyamides, and polyesteramides having free carboxyl groups (Japanese Patent Laid-Open No. 2001-59906), (2) Reaction products of low molecular weight amino compounds such as poly(lower) alkyleneimines and methyliminobispropylamine with polyesters having free carboxyl groups (JP-A-54-37082, JP-A-01-311177), (3) A reaction product obtained by sequentially reacting an isocyanate group of a polyisocyanate compound with an alcohol such as methoxypolyethylene glycol, a polyester having one hydroxyl group such as caprolactone polyester, a compound having two to three isocyanate group-reactive functional groups, and an aliphatic or heterocyclic hydrocarbon compound having an isocyanate group-reactive functional group and a tertiary amino group (Japanese Patent Laid-Open No. 02-612). (4) A compound obtained by reacting a polymer of an acrylate having an alcoholic hydroxyl group with a polyisocyanate compound and a hydrocarbon compound having an amino group; (5) A reaction product obtained by adding a polyether chain to a low molecular weight amino compound. (6) A reaction product obtained by reacting a compound having an isocyanate group with a compound having an amino group (Japanese Patent Laid-Open No. 04-210220). (7) A reaction product obtained by reacting a polyepoxy compound with a linear polymer having a free carboxyl group and an organic amine compound having one secondary amino group (JP-A-09-87537). (8) A reaction product of a polycarbonate compound having a functional group at one end capable of reacting with an amino group with a polyamine compound (Japanese Patent Laid-Open No. 09-194585), (9) Copolymers of at least one selected from methacrylic acid esters or acrylic acid esters, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, stearyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate, and benzyl acrylate, at least one basic group-containing polymerizable monomer, such as acrylamide, methacrylamide, N-methylolamide, vinylimidazole, vinylpyridine, and a monomer having an amino group and a polycaprolactone skeleton, and at least one styrene, styrene derivative, and other polymerizable monomers (Japanese Patent Laid-Open No. 01-164429), (10) Basic group-containing carbodiimide pigment dispersants (International Publication No. WO04 / 000950), (11) Block copolymers consisting of a block having a basic group such as a tertiary amino group or a quaternary ammonium salt group and a block having no functional group (see the description in JP-A-2005-55814), (12) A pigment dispersant obtained by subjecting polyallylamine to a Michael addition reaction with a polycarbonate compound (JP-A-09-194585), (13) Carbodiimide compounds having at least one polybutadiene chain and at least one basic nitrogen-containing group (JP 2006-257243 A), (14) Carbodiimide compounds having at least one amide group-containing side chain and at least one basic nitrogen-containing group in the molecule (Japanese Patent Application Laid-Open No. 2006-176657), (15) Polyurethane compounds having structural units with ethylene oxide chains and propylene oxide chains and having amino groups quaternized with a quaternizing agent (JP 2009-175613 A), (16) A compound obtained by reacting an isocyanate group of an isocyanate compound having an isocyanurate ring in the molecule with an active hydrogen group of a compound having an active hydrogen group in the molecule and having a carbazole ring and / or an azobenzene skeleton, wherein the number of carbazole rings and azobenzene skeletons in the molecule of the compound is 15 to 85% of the total number of isocyanate groups derived from the isocyanurate compound having an isocyanurate ring and urethane bonds and urea bonds formed by the reaction of the isocyanate groups with the active hydrogen groups (Patent Application No. 2009-220836). (17) Examples include graft copolymers in which polyether or polyester side chains are introduced into acrylate polymers having amino groups.

[0029] Among the basic group-containing polymeric pigment dispersants, basic group-containing urethane-based polymeric pigment dispersants, basic group-containing polyester-based polymeric pigment dispersants, and basic group-containing acrylic-based polymeric pigment dispersants are more preferred, and amino group-containing urethane-based polymeric pigment dispersants, amino group-containing polyester-based polymeric pigment dispersants, and amino group-containing acrylic-based polymeric pigment dispersants are even more preferred.Among the basic group-containing polymeric pigment dispersants, basic group (amino group)-containing polymeric pigment dispersants having at least one chain selected from the group consisting of polyester chains, polyether chains, and polycarbonate chains are particularly preferred.

[0030] The content of the pigment dispersant is preferably 1 to 200 parts by mass, and more preferably 5 to 100 parts by mass, relative to 100 parts by mass of the black colorant.

[0031] (binder resin) The pigment dispersion composition for a black matrix of the present invention contains a binder resin.

[0032] Examples of the binder resin include thermosetting resins, thermoplastic resins, photopolymerizable compounds, alkali-soluble resins, etc. These may be used alone or in combination of two or more.

[0033] Examples of the thermosetting resins and thermoplastic resins include butyral resins, styrene-maleic acid copolymers, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyvinyl acetate, polyurethane resins, phenolic resins, polyester resins, acrylic resins, alkyd resins, styrene resins, polyamide resins, rubber resins, cyclized rubbers, epoxy resins, celluloses, polybutadiene, polyimide resins, benzoguanamine resins, melamine resins, urea resins, and cardo resins.

[0034] Examples of the photopolymerizable compound include a monomer having one or more photopolymerizable unsaturated bonds in the molecule, and an oligomer having a photopolymerizable unsaturated bond.

[0035] Examples of the monomer having one photopolymerizable unsaturated bond in the molecule 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 amino groups such as N,N-dimethylaminoethyl methacrylate and N,N-dimethylaminoethyl acrylate. Examples of usable methacrylates or acrylates include alkyl 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, and dipropylene glycol monomethyl ether, methacrylic acid esters or acrylic acid esters of polyalkylene glycol monoaryl ethers such as hexaethylene glycol monophenyl ether, isobornyl methacrylate or acrylate, glycerol methacrylate or acrylate, and 2-hydroxyethyl methacrylate or acrylate.

[0036] Examples of the monomer having two or more photopolymerizable unsaturated bonds in the molecule 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 hexamethacrylate, dipentaerythritol pentamethacrylate, and the like. Methacrylate, epoxy methacrylate, 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, dipentaerythritol pentaacrylate, epoxy acrylate, and the like can be used.

[0037] As the oligomer having a photopolymerizable unsaturated bond, one obtained by appropriately polymerizing the above-mentioned monomers can be used. The above binder resins can be used alone or in combination of two or more kinds.

[0038] The alkali-soluble resin will be described later.

[0039] From the viewpoint of heat resistance and developability, the binder resin preferably has one or more structures selected from an epoxy acrylate structure and a cardo structure. The cardo structure refers to a hinge structure in which four aromatic rings are bonded to a carbon atom.

[0040] From the viewpoint of pigment dispersibility and alkaline developability, the binder resin preferably has an acid value of 10 to 200 mgKOH / g, more preferably 50 to 150 mgKOH / g.

[0041] The acid value of the binder resin means the acid value measured in accordance with JIS K5601-2-1:1999.

[0042] The content of the binder resin is preferably 3 to 50% by mass as a mass fraction relative to the total solid content of the pigment dispersion composition for black matrix of the present invention.

[0043] (pigment dispersing agent) The pigment dispersion composition for a black matrix of the present invention preferably contains a pigment dispersing aid. The pigment dispersing aid may be at least one selected from the group consisting of acid group-containing pigment derivatives and acid group-containing dye derivatives.

[0044] Examples of the acid group-containing pigment derivatives and acid group-containing dye derivatives include phthalocyanine pigment derivatives having an acid group, anthraquinone pigment derivatives having an acid group, and naphthalene pigment derivatives having an acid group. Among these, phthalocyanine pigment derivatives having a sulfonic acid group are preferred from the viewpoint of dispersibility of the black colorant.

[0045] The content of the pigment dispersing aid is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the black colorant.

[0046] (organic solvent) The pigment dispersion composition for black matrix of the present invention preferably contains an organic solvent. As the organic solvent, organic solvents that have been conventionally used in the field of liquid crystal black matrix resists can be suitably used.

[0047] Specifically, the organic solvent is a solvent that can be used under normal pressure (1.013×10 2 Examples of the organic solvent include ester-based organic solvents, ether-based organic solvents, ether ester-based organic solvents, ketone-based organic solvents, aromatic hydrocarbon-based organic solvents, and nitrogen-containing organic solvents, each of which has a boiling point of 100 to 250°C at 250°C (at 250°C / kPa). If a large amount of the organic solvent having a boiling point exceeding 250°C is contained, when a coating film formed by applying a resist composition for a black matrix obtained from the pigment dispersion composition for a black matrix of the present invention is prebaked, the organic solvent may not evaporate sufficiently and remain in the dried coating film, resulting in a decrease in the heat resistance of the dried coating film. Furthermore, if the composition contains a large amount of the organic solvent having a boiling point of less than 100°C, it may become difficult to apply the composition uniformly without unevenness, and a coating film having excellent surface smoothness may not be obtained.

[0048] Specific examples of the organic solvent include ether-based organic solvents such as 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; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ... Examples of suitable organic solvents include ether ester organic solvents such as polyethylene glycol monoethyl ether acetate; ketone organic solvents such as methyl isobutyl ketone, cyclohexanone, 2-heptanone, and δ-butyrolactone; ester organic solvents such as 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, ethyl hydroxyacetate, and n-amyl formate; alcoholic solvents such as methanol, ethanol, isopropyl alcohol, and butanol; and nitrogen-containing organic solvents such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These may be used alone or in combination of two or more.

[0049] Among the above organic solvents, in terms of solubility, dispersibility, coatability, and the like, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, ethyl 2-hydroxypropionate, 3-methyl-3-methoxybutylpropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, n-amyl formate, and the like are preferred, with propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate being more preferred.

[0050] (Potassium ion content of pigment dispersion composition for black matrix) The pigment dispersion composition for black matrix of the present invention has a potassium ion content of 100 ppm or less based on the total solid content. In the pigment dispersion composition for black matrix of the present invention, when the content of potassium ions is within the above range, a black matrix excellent in optical density and resolution can be formed. In the pigment dispersion composition for black matrix of the present invention, the content of potassium ions is preferably 90 ppm or less based on the total solid content. The potassium ion content in the pigment dispersion composition for black matrix can be adjusted, for example, by controlling the potassium ion content of the black colorant.

[0051] The potassium ion content in the pigment dispersion composition for black matrix can be measured, for example, by diluting the pigment dispersion composition for black matrix 200 times with PGMEA and performing atomic absorption analysis using a "ZA-3300" (manufactured by Hitachi High-Tech Science Corporation).

[0052] (Method of manufacturing pigment dispersion composition for black matrix) The present invention also relates to a method for producing a pigment dispersion composition for a black matrix, the method comprising: a washing step of washing a black colorant, which is carbon black having a pH of 1.0 to 2.9, until the potassium ion content is 120 ppm or less; and a mixing and kneading step of mixing and kneading the black colorant, pigment dispersant, and binder resin after the washing step.

[0053] The black colorant, pigment dispersant, and binder resin may be the same as those described above.

[0054] The washing step is not particularly limited, but may include a method in which the black colorant and purified water are stirred using a high-speed stirrer and then subjected to suction filtration. By repeating this process, the potassium ion content can be adjusted. The stirring may be carried out, for example, at 25°C for 1 hour.

[0055] The potassium ion content of the black colorant can be measured, for example, by mixing 1 part by mass of the black colorant with 99 parts by mass of 1% hydrochloric acid, shaking the mixture for 30 minutes in a paint conditioner manufactured by Red Devil, and filtering the mixture. The potassium ion content of the filtrate can be measured using an atomic absorption spectrophotometer "ZA-3300" (manufactured by Hitachi High-Tech Science Corporation).

[0056] In the mixing and kneading step, the various components described above are added and mixed and kneaded. The method for kneading is not particularly limited, and mixing and kneading may be carried out by a known method using, for example, a bead mill, a ready mill, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a Dyno Mill, a Dispermat, an SC Mill, a Nanomizer, or the like.

[0057] <Resist composition for black matrix> The present invention also relates to a resist composition for a black matrix obtained from the pigment dispersion composition for a black matrix of the present invention.

[0058] (Pigment dispersion composition for black matrix) The resist composition for a black matrix of the present invention contains the above-mentioned pigment dispersion composition for a black matrix of the present invention. The content of the pigment dispersion composition for black matrix is ​​preferably 30 to 80 mass %, and more preferably 40 to 75 mass %, based on the total mass of the resist composition for black matrix of the present invention.

[0059] (Photopolymerization initiator) The resist composition for a black matrix of the present invention preferably contains a photopolymerization initiator. The photopolymerization initiator is not particularly limited as long as it can generate radicals or cations when irradiated with active energy rays such as ultraviolet rays or electron beams. Examples of the photopolymerization initiator include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime)ethanone, benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzil dimethyl ketal, α-hydroxyisopropyl benzoate, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisopropyl benzoate, benzoin methyl ether, benzoin isobutyl ether ... isobutyl ether, benzoin isobutyl ether, benzo Examples of photopolymerization initiators include benzophenone-based, thioxanthone-based, anthraquinone-based, and triazine-based photopolymerization initiators such as tert-butylanthraquinone, 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-benzanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, and 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one. The photopolymerization initiators may be used alone or in combination of two or more.

[0060] The content of the photopolymerization initiator is preferably 1 to 20% by mass as a mass fraction relative to the total solid content of the black matrix resist composition of the present invention.

[0061] (Photopolymerizable compound) The resist composition for a black matrix of the present invention preferably contains a photopolymerizable compound. As the photopolymerizable compound, any of those described above in connection with the pigment dispersion composition for black matrix can be appropriately selected and used.

[0062] The content of the photopolymerizable compound is preferably 0.1 to 50 mass % as a mass fraction relative to the total solid content of the black matrix resist composition of the present invention.

[0063] (alkali-soluble resin) The black matrix resist composition of the present invention preferably contains an alkali-soluble resin. The alkali-soluble resin preferably acts as a binder for the black colorant and is soluble in the developer, particularly the alkaline developer, used in the development process when producing the black matrix.

[0064] The alkali-soluble resin may be a block copolymer, which has improved pigment dispersibility and solubility in PGMEA and alkaline developers compared to other copolymers. Among these block copolymers, a block copolymer having a block consisting of an ethylenically unsaturated monomer having one or more carboxyl groups and a block consisting of another copolymerizable ethylenically unsaturated monomer is preferred.

[0065] The block copolymer is not particularly limited, and conventionally used ones can be used. Specific examples thereof include copolymers of an ethylenically unsaturated monomer having a carboxyl group, such as acrylic acid or methacrylic acid, with at least one ethylenically unsaturated monomer selected from the group consisting of monomers and oligomers copolymerizable with the ethylenically unsaturated monomer having a carboxyl group, such as styrene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, allyl acrylate, allyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glycerol monoacrylate, glycerol methacrylate, N-phenylmaleimide, polystyrene macromonomer, polymethyl methacrylate macromonomer, and carboepoxy diacrylate. However, it is preferable not to use N-vinylpyrrolidone or sulfur-containing monomers. As the block copolymer, a block resin synthesized by living radical polymerization or anionic polymerization can be used. A part of the block portions of the block copolymer may be composed of a random copolymer.

[0066] As the alkali-soluble resin, an alkali-soluble cardo resin can also be used. Examples of the alkali-soluble cardo resin include an epoxy(meth)acrylate acid adduct having a fluorene skeleton, which is an addition product of a fluorene epoxy(meth)acrylic acid derivative and a dicarboxylic acid anhydride and / or a tetracarboxylic acid dianhydride. The alkali-soluble resin may also have a photopolymerizable functional group.

[0067] The acid value of the alkali-soluble resin is preferably from 5 to 300 mgKOH / g, more preferably from 5 to 250 mgKOH / g, further preferably from 10 to 200 mgKOH / g, and particularly preferably from 60 to 150 mgKOH / g, from the viewpoint of development properties. In this specification, the acid value is a theoretical acid value, which is a value calculated arithmetically based on the amount of ethylenically unsaturated monomer having a carboxyl group and its content.

[0068] The weight average molecular weight of the alkali-soluble resin is preferably from 1,000 to 100,000, more preferably from 3,000 to 50,000, and even more preferably from 5,000 to 30,000, from the viewpoint of development characteristics and solubility in organic solvents. In the present invention, the weight average molecular weight is a weight average molecular weight calculated in terms of polystyrene obtained based on GPC. In this specification, the weight-average molecular weight is measured using a Water2690 (manufactured by Waters Corporation) as an apparatus and a PLgel 5 μm MIXED-D (manufactured by Agilent Technologies) as a column.

[0069] The content of the alkali-soluble resin is preferably 1 to 200 parts by mass, and more preferably 10 to 150 parts by mass, relative to 100 parts by mass of the black colorant. In this case, if the content of the alkali-soluble resin is less than 1 part by mass, the development characteristics may be reduced, whereas if the content of the alkali-soluble resin is more than 200 parts by mass, the concentration of the black colorant will be relatively reduced, making it difficult to achieve the desired color density as a thin film.

[0070] The alkali-soluble resin preferably does not contain any primary, secondary, or tertiary amino group, and further preferably does not contain any quaternary ammonium group, and more preferably does not contain any basic group. An alkali-soluble resin having a structure other than that of a block copolymer may be blended within a range that does not impair the effects of the present invention.

[0071] (organic solvent) As the organic solvent, any of the organic solvents described above in connection with the pigment dispersion composition for black matrix can be appropriately selected and used.

[0072] The content of the organic solvent is preferably from 1 to 40% by mass, and more preferably from 5 to 35% by mass, based on the total mass of the black matrix resist composition of the present invention.

[0073] (Other additives) The black matrix resist composition of the present invention may contain various additives such as a thermal polymerization inhibitor, an ultraviolet absorber, and an antioxidant, as needed.

[0074] (Potassium ion content of black matrix resist composition) The resist composition for black matrix of the present invention has a potassium ion content of 100 ppm or less based on the total solid content. In the black matrix resist composition of the present invention, by ensuring that the potassium ion content is within the above range, it is possible to form a black matrix that is excellent in optical density and resolution. In the black matrix resist composition of the present invention, the potassium ion content is preferably 75 ppm or less relative to the total solid content. The potassium ion content in the black matrix resist composition can be adjusted, for example, by controlling the potassium ion content in the above-mentioned black matrix pigment dispersion composition.

[0075] The potassium ion content in the black matrix resist composition can be measured, for example, by diluting the black matrix resist composition 200 times with PGMEA and performing atomic absorption spectrometry using a ZA-3300 (manufactured by Hitachi High-Tech Science Corporation).

[0076] (Method of manufacturing a resist composition for black matrix) The method for producing the resist composition for a black matrix of the present invention can be, for example, by preparing the pigment dispersion composition for a black matrix of the present invention, and then adding the remaining materials and stirring and mixing them using a stirring device or the like. The method of stirring and mixing is not particularly limited, and known methods such as an ultrasonic disperser, a high-pressure emulsifier, a bead mill, a three-roll mill, a sand mill, and a kneader can be used. After the stirring and mixing, the mixture may be filtered. When preparing the resist composition for a black matrix of the present invention, the black colorant, the epoxy resin, the oxazine compound, etc. described in the pigment dispersion composition for a black matrix of the present invention may be added, if necessary.

[0077] <Black matrix> The black matrix of the present invention is formed from the black matrix resist composition of the present invention.

[0078] The method for forming the black matrix of the present invention is not particularly limited, and for example, the black matrix can be formed by applying the black matrix resist composition of the present invention onto a transparent substrate, drying the composition to form a coating film, placing a photomask on the coating film, and performing image exposure through the photomask, development, and, if necessary, photocuring, or the like.

[0079] As the methods for applying, drying, exposing, and developing the black matrix resist composition of the present invention, known methods can be appropriately selected. The transparent substrate may be selected appropriately from known transparent substrates such as a glass substrate or a plastic substrate.

[0080] The thickness of the coating film after drying is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm, and even more preferably 1 to 4 μm. By setting the thickness within the above range, a predetermined pattern can be suitably developed, and a predetermined optical density can be suitably imparted.

[0081] The black matrix of the present invention has excellent optical density. Specifically, the optical density (OD value) of the black matrix of the present invention is preferably 4.0 or more, and more preferably 4.2 or more. Within the above range, the optical density required in recent years can be satisfied.

[0082] The optical density (OD value) of the black matrix was determined by applying the black matrix resist composition to a glass substrate (Corning 1737) using a spin coater to a film thickness of 1 μm, pre-baking at 100°C for 1 minute, exposing to a high-pressure mercury lamp, and then post-baking at 230°C for 30 minutes to produce a black resist pattern consisting only of solid areas. Thereafter, the OD value of the black resist pattern was measured using a Macbeth densitometer (TD-931, product name, manufactured by Macbeth Co., Ltd.).

[0083] The black matrix of the present invention has excellent resolution. In the test below (linear adhesion evaluation test), it is preferable to obtain a line pattern of 9 μm or less, more preferably a line pattern of 6 μm or less, and even more preferably a line pattern of 4 μm or less. If the linear adhesion test results are within the above range, the resolution required in recent years can be satisfied.

[0084] The test method for evaluating the resolution (linear adhesion evaluation test) is as follows. The black matrix resist composition was applied to a glass substrate (Corning 1737) using a spin coater to a film thickness of 1 μm, and prebaked at 100° C. for 3 minutes. Next, a photomask with a line pattern spaced 1 μm apart was used for line widths of 1 μm to 10 μm (10 line widths every 1 μm), and a photomask with a line pattern spaced 2 μm apart was used for line widths of 11 to 20 μm (10 line widths every 1 μm). A high-pressure mercury lamp was used to apply a UV integrated light dose of 100 mJ / cm. 2 Expose with. Then, at 23°C, in a 0.05% potassium hydroxide aqueous solution, 1 kgf / cm 2Development begins at the time when the development pattern begins to appear (break point) at a shower development pressure of 1 kgf / cm. Development ends when the time is twice the break point. 2 The size of the smallest line pattern remaining on the glass substrate is evaluated.

[0085] The pigment dispersion composition for black matrix, the resist composition for black matrix, and the black matrix of the present invention have the above-mentioned properties and can therefore be suitably used as a black matrix for image display devices, touch panels, and the like. [Example]

[0086] The present invention will be specifically described below using examples, but the present invention is not limited to these examples as long as they do not deviate from the spirit and scope of the invention. In the examples, unless otherwise specified, "parts" and "%" represent "parts by mass" and "% by mass", respectively.

[0087] The various materials used in the following examples and comparative examples are as follows: <Black colorant> NEROX305 (product name "NEROX305", pH 2.8, average primary particle size 28 nm, DBP oil supply amount 58 ml / 100 g, manufactured by Orion Engineered Carbons) MA-8 (product name "MA-8", pH 3.0, average primary particle size 24 nm, DBP oil supply amount 58 ml / 100 g, manufactured by Mitsubishi Chemical Corporation) <Pigment dispersant> DISPERBYK-167 (amine value of solids: 25 mg KOH / g, solids content: 52% by mass, manufactured by BYK-Chemie) DISPERBYK-2150 (amine value of solids: 104 mg KOH / g, solids content: 52% by mass, manufactured by BYK-Chemie) <Pigment dispersing agent> Solsperse 5000 (quaternary ammonium salt of copper phthalocyanine sulfonate, manufactured by Lubrizol) <Binder resin> ZCR-1569H (epoxy acrylate resin, acid value 100 mg KOH / g, solid content 70 mass%, manufactured by Nippon Kayaku Co., Ltd.) WR-301 (product name "WR-301", resin with cardo structure, acid value 100 mg KOH / g, solid content 45%, manufactured by ADEKA Corporation) <Organic solvents> PGMEA (Propylene Glycol Monomethyl Ether Acetate) <Photopolymerization initiator> OXE02 (product name "Irgacure OXE02", 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime)ethanone, manufactured by BASF) <Photopolymerizable compound> DPHA (Dipentaerythritol hexaacrylate) <Alkali-soluble resin> WR-301 (product name "WR-301", cardo resin, acid value 100 mg KOH / g, solid content 45 mass%, manufactured by ADEKA Corporation)

[0088] <Cleaned NEROX305-1> 10 parts by mass of NEROX305 and 150 parts by mass of purified water were stirred at 25°C for 1 hour using a high-speed stirrer, and then subjected to suction filtration. Similar washing was repeated until the potassium ion content reached 120 ppm, and the mixture was dried to obtain washed NEROX305-1. The potassium ion content of the black colorant was measured using the method described herein. Similarly, the potassium ion content of unwashed NEROX305 was measured and found to be 450 ppm.

[0089] <Cleaned NEROX305-2> The same washing procedure as for washed NEROX305-1 was repeated until the potassium ion content was reduced to 50 ppm, and then dried to obtain washed NEROX305-2.

[0090] <Cleaned MA-8> 100 g of MA-8 was kneaded with 500 ml of ultrapure water in a twin-screw kneader for 20 minutes, and the ultrapure water was removed by filtration. The filtered carbon black was kneaded again with ultrapure water, and the filtration was repeated four times, followed by drying. The potassium ion content of the resulting washed MA-8 was 8 ppm.

[0091] <Pigment dispersion composition for black matrix> The materials were mixed to obtain the composition shown in Table 1, and kneaded overnight in a bead mill to prepare a pigment dispersion composition for black matrix. The potassium ion content of the pigment dispersion composition for black matrix was measured by the method described in this specification.

[0092] [Table 1]

[0093] <Pigment dispersion composition for black matrix> Using a high-speed stirrer, the pigment dispersion composition for black matrix and other materials (photopolymerizable compound, alkali-soluble resin, photopolymerization initiator, and organic solvent) were uniformly mixed to obtain the composition shown in Table 2. Thereafter, the mixture was filtered through a filter with a pore size of 3 μm to prepare black matrix resist compositions of Examples and Comparative Examples.

[0094] <Evaluation test> (optical density) Each of the black matrix resist compositions prepared in the Examples and Comparative Examples was applied to a glass substrate (Corning 1737) using a spin coater to a film thickness of 1 μm, prebaked at 100°C for 1 minute, exposed to a high-pressure mercury lamp, and then postbaked at 230°C for 30 minutes to prepare a black resist pattern consisting only of solid areas. Thereafter, the OD value of each of the prepared black resist patterns was measured using a Macbeth densitometer (TD-931, product name, manufactured by Macbeth Co., Ltd.). The results are shown in Table 2.

[0095] (fine wire adhesion) Each of the black matrix resist compositions prepared in the Examples and Comparative Examples was applied to a glass substrate (Corning 1737) using a spin coater to a film thickness of 1 μm, and prebaked at 100° C. for 3 minutes. Next, for line widths of 1 μm to 10 μm (10 line widths every 1 μm), a photomask with a line pattern at 1 μm intervals was used, and for line widths of 11 to 20 μm (10 line widths every 1 μm), a photomask with a line pattern at 2 μm intervals was used. A high-pressure mercury lamp was used, and a UV integrated light dose of 100 mJ / cm was used. 2 It was exposed with. Then, at 23°C, in a 0.05% potassium hydroxide aqueous solution, 1 kgf / cm 2 Development begins at the time when the development pattern begins to appear (break point) at a shower development pressure of 1 kgf / cm. Development ends when the time is twice the break point. 2 Pressure spray washing was performed. The size of the smallest line pattern remaining on the glass substrate was evaluated, and the results are shown in Table 2.

[0096] [Table 2]

[0097] In an example in which the pH of the black colorant, the amine value of the pigment dispersant, and the potassium ion content relative to the total solid content were controlled within specific ranges in a pigment dispersion composition for a black matrix containing a black colorant, a pigment dispersant, and a binder resin, it was confirmed that a black matrix with excellent optical density and resolution could be formed. [Industrial Applicability]

[0098] According to the present invention, it is possible to provide a pigment dispersion composition for a black matrix, which is capable of forming a black matrix having excellent optical density and resolution.

Claims

1. A black colorant, a pigment dispersant, and a binder resin are included, the black colorant is carbon black having a pH of 1.0 to 2.9; The pigment dispersant has an amine value of 5 to 35 mg KOH / g, and The potassium ion content is 100 ppm or less based on the total solid content. Pigment dispersion composition for black matrix.

2. 2. The pigment dispersion composition for a black matrix according to claim 1, wherein the black colorant has an average particle size of 26 to 65 nm.

3. 3. The pigment dispersion composition for a black matrix according to claim 1, wherein the black colorant has a DBP oil absorption of 80 ml / 100 g or less.

4. 4. The pigment dispersion composition for a black matrix according to claim 1, wherein the pigment dispersant has an amine value of 5 to 30 mgKOH / g.

5. 5. The pigment dispersion composition for a black matrix according to claim 1, wherein the binder resin has at least one structure selected from the group consisting of an epoxy acrylate structure and a cardo structure.

6. 6. The pigment dispersion composition for black matrix according to claim 1, wherein the content of potassium ions is 90 ppm or less based on the total solid content.

7. 7. A resist composition for black matrix obtained from the pigment dispersion composition for black matrix according to claim 1, wherein the content of potassium ions is 100 ppm or less based on the total solid content.

8. 8. The resist composition for a black matrix according to claim 7, wherein the content of potassium ions is 75 ppm or less based on the total solid content.

9. A black matrix formed from the black matrix resist composition according to claim 7 or 8.

10. a washing step of washing the black colorant, which is carbon black having a pH of 1.0 to 2.9, until the potassium ion content is 120 ppm or less; a mixing and kneading step of mixing and kneading the black colorant, pigment dispersant, and binder resin obtained after the washing step.

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