Red pigment dispersion composition for color filters

Abstract

To provide a red pigment dispersion composition for color filter capable of forming a coated film that can achieve excellent color reproducibility when quantum dots are used as backlight light source, irrespective of thin film.SOLUTION: The red pigment dispersion composition for color filter is configured such that when a chromaticity (x, y) value in a XYZ colorimetric system measured with a C light source in a CIE 1931 color system as light-emitting element is x=0.6700 to 0.6900, and y=0.3100 to 0.3300, and a coated film is formed within such chromaticity range, a thickness is 3 μm or less and the coated film satisfies (T(630)-T(600)) / (T(600)-T(590))=1.9 or more, where T(a) represents transmissivity at wavelength a nm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a red pigment dispersion composition for a color filter. [Background technology]

[0002] One of the essential technologies for realizing high image quality in image display devices is the technology for forming high-definition color filters. Color filters include those in which fine stripes of two or more different hues are arranged in parallel on the surface of a transparent substrate such as glass, or those in which fine pixels are arranged in a fixed array vertically and horizontally.

[0003] Although the pixel size is very small, ranging from tens to hundreds of μm, they must be arranged in a predetermined order for each hue. Furthermore, the pixels for each hue are required to have basic performance such as high color purity, high visible light transmittance, and high contrast.

[0004] Conventionally, for example, a coloring composition containing (A) a colorant, (B) a binder resin, and (C) a polymerizable compound has been disclosed that contains CI Pigment Red 264 as the colorant (A), and an isoindoline pigment, and the coloring composition is used to form a color filter (for example, Patent Document 1).

[0005] In recent years, in the field of image display devices, there has been an increasing demand for accurate color expression to display images with more beautiful, natural, and rich colors. For example, for the color red, there is a demand for a color filter that can achieve chromaticity coordinates x=0.6700 to 0.6900 and y=0.3100 to 0.3300 in the XYZ color system.

[0006] On the other hand, development of backlight sources using quantum dot technology is also underway, as they offer superior color reproducibility. Such backlight light sources have been disclosed, for example, as having a peak central wavelength in the range of about 615 nm to about 630 nm and exhibiting a narrow emission profile in the range of about 25 nm to about 60 nm full width at half maximum (FWHM) (e.g., Patent Document 2). For this reason, color filters used in image display devices equipped with a light source containing quantum dots are required to have the property of efficiently transmitting light of a specific wavelength (for example, 615 nm to 630 nm).

[0007] Furthermore, in recent years, in order to make image display devices thinner, there has been a demand for forming thin color filters.

[0008] However, in the conventional coloring compositions, when quantum dots are used as a backlight light source, it is not possible to obtain a red pigment dispersion composition that can realize chromaticity coordinates x=0.6700 to 0.6900 and y=0.3100 to 0.3300 in the XYZ color system, can form a coating film that can also be thin, and can efficiently transmit light from a light source containing quantum dots, so there is room for improvement. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2014-178676 A [Patent Document 2] Special Publication No. 2013-539598 Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the above problems, the present invention aims to provide a red pigment dispersion composition for color filters that can form a coating film that can achieve excellent color reproducibility even when it is a thin film when quantum dots are used as a backlight light source. [Means for solving the problem]

[0011] The red pigment dispersion composition for color filters of the present invention, when formed into a coating film having a chromaticity range of x=0.6700 to 0.6900 and y=0.3100 to 0.3300 in the XYZ color system, measured using a C light source in the CIE 1931 color system as a light-emitting element, has a film thickness of 3 μm or less, and the coating film has a transmittance at a wavelength anm of T(a) such that (T(630)-T(600)) / (T(600)-T(590)) is 1.9 or more.

[0012] The red pigment dispersion composition for color filters of the present invention preferably contains CI Pigment Red 179 and CI Pigment Yellow 139 in a mass ratio (mass of CI Pigment Red 179 / mass of CI Pigment Yellow 139) of 95 / 5 to 40 / 60. It is also preferable that CI Pigment Violet 29 is contained in an amount of 5 to 50% by mass relative to the total mass of the CI Pigment Red 179 and the CI Pigment Yellow 139. In addition, it is preferable that the ink contains a pigment dispersant, a pigment dispersion aid, an alkali-soluble resin, and an organic solvent. The pigment dispersant is preferably a basic group-containing polymeric pigment dispersant. The basic group-containing polymeric pigment dispersant is preferably an acrylic block copolymer containing a nitrogen atom. The pigment dispersing aid is preferably a sulfonic acid group-containing pigment dispersing aid. The red pigment dispersion composition for color filters of the present invention is preferably used in a color filter of an image display device equipped with a light source containing quantum dots. The red pigment dispersion composition for color filters of the present invention will be described in detail below.

[0013] <Red pigment dispersion composition for color filters> The red pigment dispersion composition for color filters of the present invention, when formed into a coating film having a chromaticity range of x=0.6700 to 0.6900 and y=0.3100 to 0.3300 in the XYZ color system, measured using a C light source in the CIE 1931 color system as a light-emitting element, has a film thickness of 3 μm or less, and the coating film has a transmittance at a wavelength anm of T(a) such that (T(630)-T(600)) / (T(600)-T(590)) is 1.9 or more.

[0014] Here, the chromaticity (x, y) value in the above-mentioned XYZ color system means a chromaticity value measured using a C light source in the CIE1931XYZ color system.

[0015] The red pigment dispersion composition for color filters of the present invention has a thickness of 3 μm or less when formed into a coating film having a chromaticity (x, y) value in the XYZ color system measured using a C light source in the CIE 1931 color system in the chromaticity range of x = 0.6700 to 0.6900 and y = 0.3100 to 0.3300. By having such a film thickness, a color filter having excellent color expression can be obtained.

[0016] The red pigment dispersion composition for color filters of the present invention has a chromaticity (x, y) value in the XYZ color system measured using a C light source in the CIE 1931 color system as a light-emitting element, in the range of x = 0.6700 to 0.6900 and y = 0.3100 to 0.3300. When a coating film is formed in this chromaticity range, where T(a) is the transmittance at a wavelength anm, the value of (T(630) - T(600)) / (T(600) - T(590)) is 1.9 or more. By having such a transmittance, it is possible to obtain a color filter having excellent color expression. The above ratio (T(630)-T(600)) / (T(600)-T(590)) is preferably 2.0 or more. The transmittance can be measured using a spectrophotometer (Shimadzu Corporation, UV-2500PC, C light source, 2° field of view).

[0017] (Pigments) The red pigment dispersion composition for color filters of the present invention preferably contains CI Pigment Red 179 and CI Pigment Yellow 139 in a mass ratio (mass of CI Pigment Red 179 / mass of CI Pigment Yellow 139) of 95 / 5 to 40 / 60. By containing CI Pigment Red 179 and CI Pigment Yellow 139 in a specific mass ratio, the film thickness at the above-mentioned specific chromaticity coordinates can be suitably controlled to 3 μm or less.

[0018] The red pigment dispersion composition for color filters of the present invention preferably contains CI Pigment Violet 29 in an amount of 5 to 50% by mass relative to the total mass of the above CI Pigment Red 179 and the above CI Pigment Yellow 139. By incorporating a specific amount of CI Pigment Violet 29, the film thickness at the above-mentioned specific chromaticity coordinates can be more suitably controlled to 3 μm or less.

[0019] The red pigment dispersion composition for color filters of the present invention may contain a red pigment, an orange pigment, and a yellow pigment that have been used in conventional red pigment dispersion compositions, as long as the effects of the present invention are not impaired. Such pigments include CI Pigment Red 177, CI Pigment Red 254, CI Pigment Red 291, and the like.

[0020] (Pigment dispersant) The red pigment dispersion composition for color filters of the present invention preferably contains a pigment dispersant, a pigment dispersing aid, an alkali-soluble resin, and an organic solvent. First, the pigment dispersant will be described.

[0021] As the pigment dispersant, a polymeric pigment dispersant having a basic group, which has been conventionally used in the field of color filters, can be used.

[0022] Examples of the polymeric pigment dispersant having a basic group include the following. (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 a free carboxyl group. (2) A carbodiimide compound having, in the molecule, at least one side chain selected from the group consisting of a polyester side chain, a polyether side chain, and a polyacrylic side chain, and at least one basic nitrogen-containing group. (3) Reaction products of low molecular weight amino compounds such as poly(lower) alkyleneimines and methyliminobispropylamine with polyesters having free carboxyl groups. (4) 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. (5) A reaction product obtained by reacting an acrylate polymer having an alcoholic hydroxyl group with a polyisocyanate compound and a hydrocarbon compound having an amino group. (6) A reaction product obtained by adding a polyether chain to a low molecular weight amino compound. (7) A reaction product obtained by reacting a compound having an isocyanate group with a compound having an amino group. (8) 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. (9) A reaction product between a polycarbonate compound having at one end a functional group capable of reacting with an amino group and a polyamine compound. (10) A copolymer 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 monomer. (11) Nitrogen-containing acrylic block copolymers consisting of a block having a basic group such as a tertiary amino group or a quaternary ammonium base and a block having no basic functional group. (12) A pigment dispersant obtained by subjecting a polyallylamine to a Michael addition reaction with a polycarbonate compound. (13) A carbodiimide compound having at least one polybutadiene chain and at least one basic nitrogen-containing group. (14) A carbodiimide compound having at least one side chain having an amide group and at least one basic nitrogen-containing group in the molecule. (15) Polyurethane compounds having structural units having ethylene oxide chains and propylene oxide chains, and having amino groups quaternized with a quaternizing agent. (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 isocyanate compound having an isocyanurate ring and urethane bonds and urea bonds generated by the reaction of the isocyanate groups with the active hydrogen groups, and the like. The above pigment dispersants can be used alone or in combination of two or more kinds.

[0023] From the viewpoint of optimally exhibiting pigment dispersibility, the pigment dispersant is preferably an acrylic resin-based polymeric pigment dispersant containing a nitrogen atom, and is more preferably an acrylic block copolymer consisting of a block having a basic group such as an amino group or a quaternary ammonium salt group and a block not having a basic functional group. It is further preferable that the nitrogen atom-containing acrylic resin-based polymeric pigment dispersant contains at least one of an AB block copolymer and a BAB block copolymer, each of which is composed of an A block having at least one of a quaternary ammonium base and an amino group in a side chain, and a B block having no quaternary ammonium base or amino group.

[0024] The content of the pigment dispersant in the pigment dispersion composition for color filters of the present invention is preferably 1 to 100 parts by mass, and more preferably 1 to 60 parts by mass, based on 100 parts by mass of the pigment. If the content of the pigment dispersant is less than 1 part by mass per 100 parts by mass of the pigment, the pigment dispersion effect may decrease, whereas if the content exceeds 100 parts by mass per 100 parts by mass of the pigment, there is a risk of reduced developability, etc.

[0025] (Pigment dispersing agent) As the pigment dispersing aid, any pigment dispersing aid that has conventionally been used in the field of color filters can be used. From the viewpoint of optimally exhibiting pigment dispersibility, however, a sulfonic acid group-containing pigment dispersing aid is preferred.

[0026] The sulfonic acid group-containing pigment dispersing aid is more preferably a sulfonated compound having an azo group and a naphthol skeleton. When the sulfonic acid group-containing pigment dispersion aid contains the compound having an azo group and a naphthol skeleton, the brightness of a color filter obtained by using the red pigment dispersion composition for color filter of the present invention can be suitably improved, and dispersibility can be improved.

[0027] Examples of the compound having an azo group and a naphthol skeleton include CI Pigment Red 2, 112, 188, CI Pigment Brown 25, and the like.

[0028] The sulfonated product of the compound having an azo group and a naphthol skeleton can be obtained by sulfonating the compound having an azo group and a naphthol skeleton. The method of sulfonation is not particularly limited, and any known method can be used.

[0029] Of these, from the viewpoint of more suitably improving the brightness of a color filter obtained using the red pigment dispersion composition for color filters of the present invention, a sulfonated product of CI Pigment Red 188 is preferred, and from the viewpoint of suitably improving the dispersion stability of the pigment and further improving the contrast of a color filter obtained using the red pigment dispersion composition for color filters of the present invention, a sulfonated product of CI Pigment Red 2 is more preferred.

[0030] The above pigment dispersing aids can be used alone or in combination of two or more kinds.

[0031] The content of the pigment dispersion aid is preferably from 0.1 to 5 mass %, and more preferably from 0.5 to 3 mass %, based on the total mass of the red pigment dispersion composition for color filters.

[0032] (alkali soluble resin) The alkali-soluble resin is not particularly limited, and any conventionally used resin can be used. However, it is preferable that the resin acts as a binder for the pigment and is soluble in a developer (preferably an alkaline developer) used in the development process when producing a color filter.

[0033] The alkali-soluble resin may be a random copolymer or a block copolymer. Among the above alkali-soluble resins, those having a carboxyl group are preferred, and in particular, copolymers consisting of an ethylenically unsaturated monomer having one or more carboxyl groups and another copolymerizable ethylenically unsaturated monomer are more preferred.

[0034] Specific examples of the alkali-soluble resin include copolymers of an ethylenically unsaturated monomer having a carboxyl group, such as acrylic acid or methacrylic acid, and 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 a monomer containing a sulfur element. The alkali-soluble resin may have a photopolymerizable functional group.

[0035] The acid value of the alkali-soluble resin is preferably from 5 to 250 mgKOH / g, more preferably from 10 to 200 mgKOH / g, and even more preferably from 60 to 150 mgKOH / g, from the viewpoint of development characteristics. In the present invention, the above 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.

[0036] In general, 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 7,000 to 20,000, from the viewpoints of development characteristics and solubility in organic solvents. In this specification, the weight average molecular weight of the alkali-soluble resin is a weight average molecular weight calculated based on polystyrene standards and obtained based on GPC. The measurement can be performed using a Water2690 (manufactured by Waters Corporation) as an apparatus and a PLgel 5 μm MIXED-D (manufactured by Agilent Technologies Corporation) as a column.

[0037] The content of the alkali-soluble resin is preferably from 1 to 200 parts by mass, and more preferably from 10 to 150 parts by mass, relative to 100 parts by mass of the pigment. If the content of the alkali-soluble resin is less than 1 part by mass relative to 100 parts by mass of the pigment, the development characteristics may be deteriorated, whereas if the content of the alkali-soluble resin is more than 200 parts by mass relative to 100 parts by mass of the pigment, the colorant concentration is relatively decreased, so that it may be difficult to achieve the desired color density as a thin film.

[0038] The alkali-soluble resin preferably contains no primary, secondary, or tertiary amino groups, and further preferably contains no quaternary ammonium groups. It is more preferable that the compound has no basic groups.

[0039] (Other resins) The red pigment dispersion composition for color filters of the present invention may contain other resins. As the other resin, it is preferable to use a resin having a higher transmittance over the entire wavelength range of 400 to 700 nm in the visible light region. As such resins, thermosetting resins, thermoplastic resins, alkali-soluble resins other than those mentioned above, and the photopolymerizable compounds described below can be used.

[0040] The total amount of the other resins used is preferably 5 to 94 mass %, more preferably 20 to 50 mass %, based on the total solid content of the red pigment dispersion composition for color filters.

[0041] 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, and urea resins. If necessary, a photopolymerizable resin described in the pigment dispersion resist composition for color filters described later can also be blended.

[0042] (Organic solvent) As the organic solvent, organic solvents that have been conventionally used in the field of liquid crystal color filter resists can be suitably used.

[0043] Specifically, the organic solvent is a solvent that is soluble in water under normal pressure (1.013×10 2 The organic solvents 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 220°C at 250 kPa. If the organic solvent contains a large amount of an organic solvent having a boiling point exceeding 220°C, when the coating film obtained by applying the red pigment dispersion composition for color filters or the red pigment dispersion resist composition for color filters described below is prebaked, the organic solvent may not evaporate sufficiently and may remain in the dried coating film, which may reduce the heat resistance of the dried coating film. Furthermore, if the organic solvent contains a large amount of an organic solvent having a boiling point of less than 100° C., it becomes difficult to apply the coating evenly and uniformly, and there is a risk that a coating film having excellent surface smoothness will not be obtained.

[0044] 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 ether acetate, propylene glycol monoethyl ether acetate, propylene ... Examples of suitable organic solvents include ether ester organic solvents such as ethyl 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; alcohol solvents such as methanol, ethanol, isopropyl alcohol, butanol, and diacetone alcohol; 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.

[0045] 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 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 acetate being more preferred.

[0046] The content of the organic solvent is preferably 30 to 80 mass % and more preferably 35 to 75 mass % based on the total mass of the red pigment dispersion composition for color filters, in terms of improving the solubility of the alkali-soluble resin, pigment dispersibility, coatability, etc.

[0047] (Method of producing red pigment dispersion composition for color filter) The red pigment dispersion composition for color filters of the present invention can be produced by adding the above-mentioned various components, mixing and kneading the mixture. As a method for adding the various components described above, for example, a plurality of pigment dispersions each containing one type of pigment may be prepared, and then the prepared pigment dispersions may be mixed together to prepare a red pigment dispersion composition for color filters.

[0048] The red pigment dispersion composition for color filters of the present invention is preferably used in a color filter of an image display device equipped with a light source containing quantum dots.

[0049] As the quantum dots, for example, the quantum dots disclosed in JP-A-2013-539598 can be used.

[0050] <Red pigment dispersion resist composition for color filters> The red pigment dispersion resist composition for color filters can be obtained by adding, in addition to the above-mentioned red pigment dispersion composition for color filters of the present invention, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, an organic solvent, and, as necessary, additives and the like.

[0051] (Red pigment dispersion composition for color filters) The above-mentioned red pigment dispersion resist composition for color filters contains the above-mentioned red pigment dispersion composition for color filters of the present invention. The content of the red pigment dispersion composition for color filters is preferably 30 to 80 mass %, and more preferably 40 to 75 mass %, based on the total mass of the red pigment dispersion resist composition for color filters of the present invention.

[0052] (alkali soluble resin) As the alkali-soluble resin, any of the alkali-soluble resins described above in relation to the red pigment dispersion composition for color filters of the present invention can be appropriately selected and used.

[0053] The content of the alkali-soluble resin is preferably from 1 to 35 mass %, and more preferably from 3 to 30 mass %, based on the total mass of the red pigment dispersion resist composition for color filters of the present invention.

[0054] (Photopolymerizable compound) Examples of the photopolymerizable compound include monomers, oligomers, etc. having one or more photopolymerizable unsaturated bonds in the molecule. The photopolymerizable unsaturated bond is an unsaturated bond that can be polymerized by the action of radicals or cations generated when a photopolymerization initiator described later is decomposed by active energy rays such as ultraviolet rays or electron beams.

[0055] Examples of the monomer having one photopolymerizable unsaturated bond in the molecule include alkyl methacrylates or acrylates such as methyl (meth)acrylate, butyl (meth)acrylate, 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; N,N-dimethylaminoethyl methacrylate and N,N-dimethylaminoethyl acrylate; methacrylic acid esters or acrylic acid esters of polyalkylene glycol alkyl ethers such as diethylene glycol ethyl ether, triethylene glycol butyl ether, dipropylene glycol methyl ether, etc.; methacrylic acid esters or acrylic acid esters of polyalkylene glycol aryl ethers such as hexaethylene glycol phenyl ether; isobornyl methacrylate or acrylate; glycerol methacrylate or acrylate; 2-hydroxyethyl methacrylate or acrylate, etc. In this specification, (meth)acrylate means acrylate and methacrylate.

[0056] 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 hexameth ... Examples of the copolymer include pentaerythritol 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. The above photopolymerizable compounds can be used alone or in combination of two or more.

[0057] The content of the photopolymerizable compound is preferably from 0.5 to 20% by mass, and more preferably from 1 to 10% by mass, based on the total mass of the red pigment dispersion resist composition for color filters of the present invention.

[0058] (Photopolymerization initiator) The photopolymerization initiator is not particularly limited as long as it can generate radicals or cations by irradiation with active energy rays such as ultraviolet rays or electron beams. Examples of the photopolymerization initiator include 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-hydroxypropyl benzoyl ether ... Examples of the photopolymerization initiator include hydroxycyclohexyl phenyl ketone, t-butyl anthraquinone, 1-chloro anthraquinone, 2,3-dichloro anthraquinone, 3-chloro-2-methyl anthraquinone, 2-ethyl anthraquinone, 1,4-naphthoquinone, 1,2-benzoanthraquinone, 1,4-dimethyl anthraquinone, 2-phenyl anthraquinone, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, and triazine-based photopolymerization initiators. The above photopolymerization initiators can be used alone or in combination of two or more.

[0059] The content of the photopolymerization initiator is preferably from 0.1 to 5 mass %, and more preferably from 0.5 to 3 mass %, based on the total mass of the red pigment dispersion resist composition for color filters of the present invention.

[0060] (Organic solvent) As the organic solvent, any of the organic solvents described above in relation to the red pigment dispersion composition for color filters of the present invention can be appropriately selected and used.

[0061] The content of the organic solvent is preferably from 1 to 40 mass %, and more preferably from 5 to 35 mass %, based on the total mass of the red pigment dispersion resist composition for color filter of the present invention.

[0062] (Other additives) The red pigment dispersion resist composition for color filters of the present invention may contain additives within the range that does not impair the effects of the present invention. Examples of the additives include various additives such as a thermal polymerization inhibitor, a silane coupling agent, a titanate coupling agent, an ultraviolet absorbing agent, and an antioxidant.

[0063] (Method of manufacturing a red pigment-dispersed resist composition for color filters) The method for producing the red pigment dispersion resist composition for color filters of the present invention is not particularly limited, and the composition can be obtained by mixing the above-mentioned materials by a known method and kneading the mixture.

[0064] <Color filter> The red pigment-dispersed resist composition for color filters of the present invention can be used to form color filters. The color filter comprises a red filter segment, a green filter segment, and a blue filter segment, and the red filter segment among them is formed from the red pigment dispersion resist composition for color filters of the present invention. The green filter segment and the blue filter segment can be formed using known materials and methods. A color filter formed by using the red pigment dispersion resist composition for color filters of the present invention can be formed by appropriately selecting a known method such as a printing method or a photolithography method.

[0065] <Display device> The color filter can be used as a display device. The display device is not particularly limited as long as it includes the above-mentioned color filter of the present invention, and examples of the display device include known liquid crystal display devices and touch panels. The light source of the display device preferably includes the quantum dots described above. Effect of the Invention

[0066] The present invention can provide a red pigment dispersion composition for color filters that can form a coating film that can achieve excellent color reproducibility even when it is a thin film when quantum dots are used as a backlight light source. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by mass" and "parts" means "parts by mass."

[0068] The materials used in the examples and comparative examples are as follows.

[0069] <Pigments> (PR179) CI Pigment Red 179 (PV29) CI Pigment Violet 29 (PY139) CI Pigment Yellow 139 (PR177) CI Pigment Red 177 (PR254) CI Pigment Red 254 (PR291) CI Pigment Red 291 <Pigment dispersant> (Nitrogen-containing acrylic block copolymer) Acrylic block copolymer containing tertiary amino groups (LP-N21116, BYK Chemie) <Pigment dispersion aid> (PR2S) 30ml of concentrated sulfuric acid was placed in a 100ml Erlenmeyer flask, and 10g of CI Pigment Red 2 was added while stirring with a magnetic stirrer, and stirred at room temperature for 30 minutes. A mixture of 50g of water and 50g of ice was placed in a 1L beaker, and the above reaction product was poured into the ice water and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed under reduced pressure, and the obtained solid was dried to produce a sulfonic acid group-containing pigment dispersing aid (sulfonated CI Pigment Red 2, PR2S). <Alkali-soluble resin> (BMA / MAA copolymer) Butyl methacrylate / methacrylic acid copolymer (Follet ZAH110, manufactured by Soken Chemical Industries, Ltd., solid content 35%) <Organic solvent> (PGMEA) Propylene glycol monomethyl ether acetate <Photopolymerizable compound> (DPHA) Dipentaerythritol hexaacrylate (A9530, Shin-Nakamura Chemical Co., Ltd.) <Photopolymerization initiator> (Irgacure 369) 2-(Dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone

[0070] <Preparation of Red Pigment Dispersion Composition for Color Filter> Pigment dispersions 1 to 6 were prepared by adding the various components described above in the amounts shown in Table 1. Thereafter, the pigment dispersions 1 to 6 were mixed and kneaded in the mass ratios shown in Table 2 to prepare red pigment dispersion compositions for color filters of Examples and Comparative Examples.

[0071] [Table 1]

[0072] [Table 2]

[0073] <Preparation of Red Pigment Dispersed Resist Composition for Color Filter> Various materials were added so that the various components described above had the composition shown in Table 3, and after uniformly mixing using a high-speed stirrer, the mixture was filtered through a membrane filter having a pore size of 3 μm to prepare red pigment-dispersed resist compositions for color filters of the Examples and Comparative Examples.

[0074] [Table 3]

[0075] (viscosity) The viscosity of the red pigment dispersion resist compositions for color filters prepared in the Examples and Comparative Examples was measured at 25° C. using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., R100 type viscometer, model RE100L). The results are shown in Table 4.

[0076] (dispersion stability) The red pigment dispersion resist compositions for color filters prepared in the Examples and Comparative Examples were each placed in a glass bottle, sealed, and stored for one month at temperatures of 40°C, 5°C, and room temperature (23°C), and then evaluated according to the following evaluation criteria. The results are shown in Table 4. ○: Viscosity change rate before and after storage is 10% or less ×: Viscosity change rate before and after storage exceeds 10%

[0077] (Coating thickness) The pigment dispersion resist compositions for color filters of the Examples and Comparative Examples were applied to a glass substrate using a spin coater, and prebaked at 100° C. for 3 minutes. At this time, two coated plates were prepared by applying each resist composition so that two coating films with different chromaticity x (value after post-baking described later) were formed. That is, the rotation speed of the spin coater was changed to change the thickness, so that the chromaticity x of one of the two plates was always smaller than 0.6800, and the chromaticity x of the other plate was always larger than 0.6800. Next, each coated plate was exposed to a high pressure mercury lamp and further post-baked at 230°C for 30 minutes. After that, three scratches were made with a cutter within a range of 3 mm on the coated plate, and the depth was measured by scanning using a surface roughness measuring device (KLA-Tencor Corporation Surface Profiler ALPHA-STEP IQ). The average value of the three points was calculated and used as the film thickness of the coating film. For each coating film, an approximate straight line (calibration curve) was obtained from the measured values ​​of the two coated plates prepared as described above, and the film thickness when the chromaticity x was 0.6800 was calculated and adopted as the film thickness of the examples and comparative examples.

[0078] (Brightness of coating film) The luminance Y of each of the coated plates of the pigment dispersion resist composition for color filters obtained by the above method was measured using a spectrophotometer (Shimadzu Corporation, UV-2500PC, C light source, 2° field of view). For each coating film formed on the coated plate, an approximate straight line (calibration curve) was obtained from the luminance values ​​Y of the two coated plates prepared as described above, and the value of chromaticity x of 0.6800 was calculated and adopted as the luminance value Y of the examples and comparative examples.

[0079] (y value of coating) The chromaticity y value of each of the coated plates of the pigment dispersion resist composition for color filters obtained by the above method was measured using a spectrophotometer (Shimadzu Corporation, UV-2500PC, C light source, 2° field of view). For each coating film formed on the coated plate, an approximate straight line (calibration curve) was obtained from the chromaticity y of the two coated plates prepared as described above, and the y value when the chromaticity x was 0.6800 was calculated and adopted as the y value for the examples and comparative examples.

[0080] (Transmittance of coating film) For each of the coated plates of the pigment dispersion resist composition for color filters obtained by the above method, the transmittance was measured at 10 nm intervals from 590 nm to 670 nm using a spectrophotometer (Shimadzu Corporation, UV-2500PC, C light source, 2° field of view). For each of the above wavelengths, an approximate straight line (calibration curve) was obtained from the transmittance values ​​of the two coated plates prepared as described above, and the chromaticity x value of 0.6800 was calculated and adopted as the transmittance for the examples and comparative examples. In addition, (T(630)-T(600)) / (T(600)-T(590)) was calculated when the transmittance at the wavelength amm was T(a). The results are shown in Table 4.

[0081] [Table 4] [Industrial Applicability]

[0082] The red pigment dispersion composition for color filters of the present invention can form a coating film that can achieve excellent color reproducibility even in a thin film when quantum dots are used as a backlight light source, and therefore can be suitably used as a red pigment dispersion resist composition for color filters used in color filters of liquid crystal display devices, touch panels, and the like.

Claims

1. when a coating film is formed in a chromaticity range of x=0.6700 to 0.6900 and y=0.3100 to 0.3300 in the XYZ color system measured using a C light source in the CIE 1931 color system as a light-emitting element, the coating film has a thickness of 3 μm or less, and when the transmittance at a wavelength of a nm is T(a), the coating film has a value of (T(630)-T(600)) / (T(600)-T(590)) of 1.9 or more, Contains C.I. Pigment Red 179 and C.I. Pigment Yellow 139 in a mass ratio (mass of C.I. Pigment Red 179 / mass of C.I. Pigment Yellow 139) of 95 / 5 to 40 / 60; The C.I. Pigment Red 179 and the C.I. Pigment Yellow 139 are combined to contain C.I. Pigment Violet 29 in an amount of 5 to 50% by mass. Red pigment dispersion composition for color filters.

2. 2. The red pigment dispersion composition for color filters according to claim 1, comprising a pigment dispersant, a pigment dispersion assistant, an alkali-soluble resin, and an organic solvent.

3. 3. The red pigment dispersion composition for color filters according to claim 2, wherein the pigment dispersant is a basic group-containing polymeric pigment dispersant.

4. 4. The red pigment dispersion composition for color filters according to claim 3, wherein the basic group-containing polymeric pigment dispersant is an acrylic block copolymer containing a nitrogen atom.

5. 5. The red pigment dispersion composition for color filters according to claim 2, wherein the pigment dispersion aid is a sulfonic acid group-containing pigment dispersion aid.

6. The red pigment dispersion composition for color filters according to any one of claims 1 to 5, which is used in a color filter of an image display device equipped with a light source containing quantum dots.

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