Red colored composition for color filters, red colored resist composition for color filters, color filters, and display devices.

Abstract

To provide a color filter red coloring composition which offers superior dispersion stability and is capable of suppressing water-induced irregularity during manufacturing of a color filter.SOLUTION: A color filter red coloring composition is provided, containing a coloring pigment, pigment dispersant, pigment dispersion aid, resin, and organic solvent. The coloring pigment contains C.I.Pigment Red 179. The pigment dispersant has a quaternary ammonium salt. The resin contains an acrylic resin having a double bond.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a red coloring composition for a color filter, a red coloring resist composition for a color filter, a color filter, and a display device.

Background Art

[0002] As an essential technology for realizing high image quality of liquid crystal televisions, there is a technology for forming a high-definition color filter. As the color filter, there are those in which fine bands (stripes) of two or more different hues are arranged in parallel on the surface of a transparent substrate such as glass, and those in which fine pixels are arranged in a fixed array vertically and horizontally.

[0003] The pixel size is as fine as several tens to several hundreds of μm, but it needs to be arranged neatly in a predetermined order for each hue. Further, for the pixels of each hue, as basic performance, high color purity, high transmittance of visible light, and high contrast are required.

[0004] Conventionally, for example, in a coloring composition containing (A) a colorant, (B) a binder resin, and (C) a polymerizable compound, it is disclosed that a color filter is formed using a coloring composition characterized by containing C.I. Pigment Red 264 and an isoindoline-based pigment as (A) the colorant (for example, Patent Document 1).

[0005] In recent years, in the technical field of color filters, in addition to the mainstream of reducing the exposure amount to shorten the tact time, in order to meet the increasing requirements for color purity, the proportion of the coloring pigment in the coloring composition has a tendency to become increasingly high.

[0006] Under such circumstances, during the production of a color filter, at the stage where the water washing process performed after the development of the color filter is completed, uneven color in the form of stains (hereinafter referred to as "water unevenness") occurs on the pixel pattern, and this water unevenness obstructs the subsequent inspection process and reduces the production efficiency, and the problem has become apparent. Conventional coloring compositions have not adequately solved the problem of uneven coloring with water, and there was room for further improvement. Furthermore, conventional coloring compositions still had room for improvement in terms of dispersion stability (also simply called dispersion stability) when photopolymerizable compounds, photopolymerization initiators, etc. were added. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-178676 [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above problems, the present invention aims to provide a red coloring composition for color filters that has excellent dispersion stability and can suppress the occurrence of water unevenness during the manufacture of color filters. [Means for solving the problem]

[0009] In view of the above-mentioned problems, the present inventors conducted extensive research and, as a result, found that in a red colored composition for color filters containing a colored pigment, a pigment dispersant, a pigment dispersant aid, a resin, and an organic solvent, the colored pigment contains CI Pigment Red 179, the pigment dispersant has a quaternary ammonium salt structure, and the resin contains an acrylic resin having a double bond, thereby suppressing the occurrence of the above-mentioned water unevenness, and thus completed the present invention.

[0010] In other words, the red colored composition for color filters of the present invention contains a coloring pigment, a pigment dispersant, a pigment dispersant aid, a resin, and an organic solvent, wherein the coloring pigment contains CI Pigment Red 179, the pigment dispersant has a quaternary ammonium salt structure, and the resin contains an acrylic resin having a double bond. In the red coloring composition for color filters of the present invention, it is preferable that the coloring pigment further contains CI Pigment Yellow 139. Furthermore, it is preferable that the above-mentioned coloring pigment further contains CI Pigment Violet 29. Furthermore, it is preferable that the above-mentioned pigment dispersant has a quaternization rate expressed as the number of quaternary ammonium salts relative to the total number of amines in the pigment dispersant of 15 to 50 mol%. Furthermore, the above-mentioned pigment dispersion aid is preferably a sulfonated form of CI Pigment Red 2 and / or a sulfonated form of CI Pigment Yellow 138. Furthermore, it is preferable that the double bond equivalent contained in the acrylic resin having the double bond is 300 to 2000 g / mol. The present invention is also a red colored resist composition for color filters obtained from the above-mentioned red colored composition for color filters. Furthermore, the present invention is also a color filter formed by the above-mentioned red colored resist composition for color filters. Furthermore, the present invention is also a display device that includes the above-mentioned color filter. The following describes in detail the red colored composition for color filters, the red colored resist composition for color filters, the color filter, and the display device of the present invention. [Effects of the Invention]

[0011] This invention provides a red coloring composition for color filters that exhibits excellent dispersion stability and can suppress the occurrence of water unevenness during the manufacturing of color filters. [Modes for carrying out the invention]

[0012] <Red coloring composition for color filters> The red coloring composition for a color filter of the present invention contains a coloring pigment, a pigment dispersant, a pigment dispersion aid, a resin, and an organic solvent. The coloring pigment contains C.I. Pigment Red 179. The pigment dispersant has a quaternary ammonium salt structure. The resin contains an acrylic resin having a double bond. Thereby, while sufficiently imparting dispersion stability, the double bond possessed by the acrylic resin improves the curability of the coating film when the coating film of the red coloring resist composition for a color filter is irradiated with ultraviolet rays, and contributes to suppressing unevenness in water. However, the present invention may not be construed as being limited to the above mechanism.

[0013] (Coloring Pigment) The red coloring composition for a color filter of the present invention contains a coloring pigment. The coloring pigment contains C.I. Pigment Red 179.

[0014] From the viewpoint of color reproducibility, it is preferable that the coloring pigment further contains C.I. Pigment Yellow 139.

[0015] From the viewpoint of color reproducibility, it is preferable that the coloring pigment further contains C.I. Pigment Violet 29.

[0016] The coloring pigment may contain known pigments as long as the effects of the present invention are not inhibited.

[0017] From the viewpoint of suitably imparting color purity, it is preferably contained in a mass fraction of 50 to 95% by mass, more preferably 70 to 90% by mass, based on the total solid content of the red coloring composition for a color filter.

[0018] In the coloring pigment, C.I. Pigment Red 179 is preferably contained in a mass fraction of 50 to 100% by mass, more preferably 60 to 80% by mass, based on the total mass of the coloring pigment.

[0019] In the above coloring pigment, C.I. Pigment Yellow 139 is preferably contained at 0 to 25% by mass, more preferably 10 to 20% by mass, based on the total mass of the coloring pigment.

[0020] In the above coloring pigment, C.I. Pigment Violet 29 is preferably contained at 0 to 25% by mass, more preferably 10 to 20% by mass, based on the total mass of the coloring pigment.

[0021] (Pigment dispersant) The red coloring composition for a color filter of the present invention contains a pigment dispersant. The above pigment dispersant has a quaternary ammonium salt structure.

[0022] As the above pigment dispersant, for example, from the viewpoint of improving the re-solubility in the solvent of the obtained red coloring composition for a color filter and reducing the viscosity, a polymer having a structural unit derived from an amino group-containing monomer (hereinafter also referred to as "(A-1) component") and a structural unit derived from an alkoxypolyalkylene glycol (meth)acrylate (hereinafter also referred to as "(A-2) component"), and the polyalkylene glycol portion of (A-2) is a mixed adduct of propylene oxide and ethylene oxide, is preferably composed of a polymer.

[0023] From the viewpoint of dispersion stability, the above pigment dispersant preferably has a quaternization rate (number of quaternary ammonium salts in the pigment dispersant) / (total number of amines in the pigment dispersant) represented by the number of quaternary ammonium salts with respect to the total number of amines in the above polymer pigment dispersant of 15 to 50 mol%, more preferably 30 to 50 mol%. Note that the "quaternization rate" means the ratio (mol%) of the molar equivalent number of quaternary ammonium groups to the total molar equivalent number of tertiary amino groups and quaternary ammonium groups contained in the pigment dispersant, and can be calculated from the following formula using the amine value determined by potentiometric titration with an alcoholic hydrochloric acid standard solution in accordance with the ASTM D 2073 measurement method. Quaternization rate [mol%] = {(Amine value of pigment dispersant before quaternization - Amine value of pigment dispersant after quaternization) / Amine value of pigment dispersant before quaternization} × 100

[0024] The above quaternization rate can be obtained, for example, by quaternizing component (A-1) and introducing a quaternary ammonium group, but it can also be obtained by copolymerizing component (A-1), component (A-2), and a monomer component having a quaternary ammonium group (hereinafter also referred to as "component (A-3)"). Furthermore, if the amine value of the pigment dispersant before quaternization is unknown, or if a dispersant copolymerized with a monomer having a quaternized ammonium group is used, the value calculated from the content of tertiary amino groups and quaternary ammonium groups identified by nuclear magnetic resonance (NMR) can be considered as the quaternization rate.

[0025] The mass ratio of the constituent units derived from component (A-1) to the constituent units derived from component (A-2) in the pigment dispersant [component (A-1) / component (A-2)] is preferably 10 / 90 to 49 / 51, more preferably 13 / 87 to 40 / 60, even more preferably 13 / 87 to 20 / 80, and still more preferably 15 / 85 to 20 / 80, from the viewpoint of improving the dispersibility of the colored pigment and enhancing storage stability.

[0026] Furthermore, if the pigment dispersant is quaternarily graded, the above mass ratio shall be the mass ratio excluding the components derived from the quaternarily graded agent. Furthermore, the "mass ratio excluding components derived from the quaternizing agent" refers to the converted mass of the constituent units excluding the components derived from the quaternizing agent that form the quaternary ammonium group, i.e., the alkyl group derived from the quaternizing agent and the mass of the paired anionic component. The alkyl group introduced by quaternization can be estimated by comparing the alkyl group of the tertiary amino group derived from (A) remaining in the dispersant with the alkyl group of the quaternary ammonium group. In this specification, "constituent units derived from component (A-1)" includes constituent units in which the tertiary amino group of component (A-1) has been quaternized to become a quaternary ammonium group.

[0027] The above pigment dispersant may contain constituent units derived from monomers other than component (A-1) and component (A-2) as long as it does not impair the effects of the present invention, but the content of component (A-1) and component (A-2) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and even more preferably consists only of component (A-1) and component (A-2).

[0028] The weight-average molecular weight of the above-mentioned pigment dispersant, in terms of polyethylene glycol, is preferably 5,000 to 200,000, more preferably 10,000 to 150,000, and even more preferably 10,000 to 20,000, from the viewpoint of improving the dispersibility of colored pigments and enhancing storage stability. The weight-average molecular weight can be measured by the method described in the examples. If some of the amino groups have been quaternized and the molecular weight cannot be measured directly, the weight-average molecular weight of the polymer before quaternization will be considered as the molecular weight of this dispersant.

[0029] As for the above (A-1) component, from the viewpoint of improving the dispersibility of the coloring pigment, dialkylaminoalkyl(meth)acrylamide is preferred, dimethylaminoalkyl(meth)acrylamide or diethylaminoalkyl(meth)acrylamide is more preferred, and dimethylaminoalkyl(meth)acrylamide is even more preferred. In this specification, (meth)acrylamide means acrylamide and / or methacrylamide. From the viewpoint of the above, dimethylaminoalkyl(meth)acrylamide is preferred, and N,N-dimethylaminopropylacrylamide or N,N-dimethylaminoethylacrylamide is preferred, and among these, N,N-dimethylaminoethylacrylamide is preferred from the viewpoint of strong adsorption to the surface of the colored pigment.

[0030] It is preferable that the amino group of component (A-1) above is quaternized, that is, it is preferable that component (A-1) is treated with a quaternizing agent to introduce a quaternary ammonium group. When the above component (A-1) is treated with a quaternizing agent to introduce a quaternary ammonium group, the alkyl group introduced to the amino group is preferably an ethyl group or a methyl group, with a methyl group being more preferable. Furthermore, the counterion of the quaternary ammonium group is preferably one or more selected from alkyl sulfate ions, halogen ions, and p-toluenesulfonate ions, with alkyl sulfate ions being more preferred, and methyl sulfate ions being even more preferred. Due to quaternary merization, component (A-1) is presumed to exist in the polymer in the form of a monomer having a quaternary ammonium group, more specifically, as a unit such as (meth)acryloylaminoalkyltrimethylammonium salt or (meth)acryloylaminoalkyltriethylammonium salt. In this specification, (meth)acryloyl means acryloyl and / or methacryloyl. Furthermore, the pigment dispersant of the present invention may be obtained by copolymerizing the above-mentioned ammonium salt as a monomer component as component (A-3).

[0031] In the above-mentioned pigment dispersant, the content of the constituent unit derived from component (A-1) in the total constituent units is preferably 3 to 46% by mass, more preferably 10 to 40% by mass, even more preferably 10 to 30% by mass, and even more preferably 14 to 20% by mass, from the viewpoint of improving the dispersibility of the colored pigment. Furthermore, if some of the amino groups are quaternized, the content is calculated based on the converted mass excluding the mass of the component derived from the quaternizing agent. When a portion of the amino groups are quaternized, the content of non-quaternized constituent units derived from component (A-1) in the total constituent units of the pigment dispersant is preferably 1 to 41% by mass, more preferably 5 to 30% by mass, even more preferably 7 to 20% by mass, and even more preferably 10 to 17% by mass, from the viewpoint of improving the dispersibility of the colored pigment. Here, the content is expressed in converted mass after excluding the mass of components derived from the quaternizing agent. The content of the constituent units derived from component (A-1) in the total constituent units of the above-mentioned pigment dispersant, which are quaternized, is preferably 0.3 to 36% by mass, more preferably 3 to 20% by mass, even more preferably 4 to 14% by mass, and even more preferably 5 to 8% by mass, from the viewpoint of improving the dispersibility of the colored pigment. Here, the content is given in terms of converted mass excluding the mass of the component derived from the quaternizing agent.

[0032] The above component (A-2) has a polyalkylene glycol portion which is a mixed adduct of propylene oxide (hereinafter also referred to as "PO") and ethylene oxide (hereinafter also referred to as "EO"). The alkoxypolyalkylene glycol (meth)acrylate may be either alkoxypolyalkylene glycol methacrylate or alkoxypolyalkylene glycol acrylate, but alkoxypolyalkylene glycol methacrylate is preferred. In this specification, (meth)acrylate means acrylate and / or methacrylate.

[0033] The weight ratio of ethylene oxide-derived constituent units to propylene oxide-derived constituent units in the polyalkylene glycol portion of component (A-2) above [(ethylene oxide-derived constituent units) / (propylene oxide-derived constituent units)] is preferably 10 / 90 to 50 / 50, more preferably 20 / 80 to 40 / 60, and even more preferably 30 / 70 to 45 / 55, from the viewpoint of improving resolubility in the solvent after drying. Furthermore, from the viewpoint of improving the dispersibility of the colored pigment in organic solvents, the polyalkylene glycol portion is more preferably a block adduct in which the methacrylate side is ethylene oxide and the terminal side is propylene oxide. Such block adducts are not particularly limited, but can be obtained, for example, by the following method: Using alkoxypropylene glycol or alkoxydipropylene glycol as a starting material, propylene oxide is subjected to ring-opening polymerization in the presence of a base catalyst, and then ethylene oxide is subjected to further ring-opening polymerization in the presence of a base catalyst to obtain alkoxypolypropylene glycol polyethylene glycol. Furthermore, alkoxypolyalkylene glycol (meth)acrylate (A-2) can be obtained by dehydrating the alkoxypolypropylene glycol polyethylene glycol with (meth)acrylic acid.

[0034] From the viewpoint of improving resolubility in the solvent after drying, the average number of alkylene oxides added to the polyalkylene glycol portion of the alkoxy polyalkylene glycol (meth)acrylate (A-2) is preferably 20 to 200, and more preferably 20 to 150, more preferably 20 to 50, even more preferably 30 to 43, and even more preferably 30 to 40, from the viewpoint of improving the dispersibility of the coloring pigment. As for the alkoxy polyalkylene glycol (meth)acrylate (A-2), from the viewpoint of improving dispersibility, the alkoxy group has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy groups and ethoxy groups, with methoxy groups being preferred.

[0035] The content of the constituent units derived from component (A-2) in the total constituent units of the above pigment dispersant is preferably 51 to 95% by mass, more preferably 60 to 90% by mass, even more preferably 70 to 90% by mass, and even more preferably 80 to 90% by mass, from the viewpoint of improving resolubility in the solvent after drying. Furthermore, if the amino group of component (A-1) above is quaternized, the above content shall be the converted mass excluding the mass of the component derived from the quaternizing agent.

[0036] The above-mentioned pigment dispersant can be produced by copolymerizing a mixture of component (A-1) and component (A-2) using a known polymerization method.

[0037] As a method for producing the above-mentioned pigment dispersant, component (A-3) may be further copolymerized in the above-mentioned production method.

[0038] As component (A-3) above, (meth)acryloylaminoalkyltrialkylammonium salt can be used, but (meth)acryloylaminoalkyltrimethylammonium salt is preferred from the viewpoint of improving adsorption to coloring pigments, maintaining a low viscosity of the red coloring composition for color filters, enhancing storage stability, and improving the contrast of the cured film. From the above viewpoint, acryloylaminoalkyltrimethylammonium salt is preferred, and acryloylaminopropyltrimethylammonium salt or acryloylaminoethyltrimethylammonium salt is more preferred, and among these, acryloylaminopropyltrimethylammonium salt is preferred from the viewpoint of strong adsorption to the surface of the coloring pigment. The counterion for the quaternary ammonium group of the above ammonium salt is preferably one or more selected from alkyl sulfate ions, halide ions, and p-toluenesulfonate ions, with alkyl sulfate ions being more preferred. Furthermore, the grade 4 classification rate can be adjusted by adjusting the ratio of component (A-3) to component (A-1) and component (A-2) described above.

[0039] The amount of the pigment dispersant is preferably 1 to 100 parts by mass, and more preferably 1 to 60 parts by mass, per 100 parts by mass of the colored pigment. If the amount of the pigment dispersant is less than 1 part by mass per 100 parts by mass of the colored pigment, the pigment dispersion effect may decrease. On the other hand, if the amount exceeds 100 parts by mass per 100 parts by mass of the colored pigment, there is a risk that the developability may decrease.

[0040] (Pigment dispersant) The red coloring composition for color filters of the present invention contains a pigment dispersion aid.

[0041] The above-mentioned pigment dispersion aid is more preferably a sulfonated pigment having an azo group and a naphthol skeleton, or a sulfonated pigment having an isindole skeleton.

[0042] Examples of pigments having the above-mentioned azo group and naphthol skeleton include CI Pigment Red 2, 112, 188, and CI Pigment Brown 25.

[0043] Examples of pigments having the above-mentioned isoindole skeleton include CI Pigment Yellow 138.

[0044] From the viewpoint of improving dispersion stability and appropriately imparting color purity, the above-mentioned pigment dispersion aid is preferably a sulfonated form of CI Pigment Red 2 and / or a sulfonated form of CI Pigment Yellow 138.

[0045] The amount of the above-mentioned pigment dispersion aid is preferably 1 to 100 parts by mass, and more preferably 1 to 60 parts by mass, per 100 parts by mass of the above-mentioned colored pigment.

[0046] (resin) The red coloring composition for color filters of the present invention contains a resin. The above resin contains an acrylic resin having a double bond.

[0047] Examples of acrylic resins having the above-mentioned double bond include copolymers of an ethylenically unsaturated monomer having a carboxyl group, such as (meth)acrylic acid, and a monomer copolymerizable with the ethylenically unsaturated monomer having a carboxyl group.

[0048] Examples of the ethylenically unsaturated monomers having the carboxyl group mentioned above include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyltoluene, vinyl ethyl ether, perfluorohexylethyl-thio-carbonyl-aminoethyl-methacrylate, isobornyl methacrylate, trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, and siloxane-containing vinyl monomers.

[0049] Examples of monomers copolymerizable with the above-mentioned ethylenically unsaturated monomers having a carboxyl group include monomers and oligomers 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.

[0050] From the viewpoint of effectively suppressing water unevenness, the above resin preferably contains a double bond equivalent of 300 to 2000 g / mol, and more preferably 300 to 1000 g / mol.

[0051] The double bond equivalent mentioned above can be calculated using the following formula. Double bond equivalent (g / mol) = Mass of resin (g) / Amount of vinyl ((meth)acryloyl) groups in the resin (mol)

[0052] The above resin may contain resins other than acrylic resins having double bonds, as long as they do not impair the effects of the present invention, but it is preferable that it consists of an acrylic resin having double bonds.

[0053] The weight-average molecular weight of the above resin is generally preferably 1,000 to 100,000, more preferably 3,000 to 50,000, and even more preferably 10,000 to 30,000, from the viewpoint of developing characteristics and solubility in organic solvents. In this specification, the weight-average molecular weight of the alkali-soluble resin is the weight-average molecular weight on a polystyrene basis obtained based on GPC. The measurement can be performed using a Water2690 instrument (Waters Corporation) and a PLgel 5μm MIXED-D column (Agilent Technologies).

[0054] Commercially available resins such as the AX3-RD series from Nippon Shokubai Co., Ltd. and the Lipoxy series from Showa Denko Corporation can be appropriately selected.

[0055] The content of the above resin is preferably 1 to 200 parts by mass, and more preferably 10 to 150 parts by mass, per 100 parts by mass of the above coloring pigment. If the resin content is less than 1 part by mass per 100 parts by mass of the coloring pigment, the development characteristics may deteriorate. On the other hand, if the resin content exceeds 200 parts by mass per 100 parts by mass of the coloring pigment, the relative concentration of the coloring pigment will decrease, which may make it difficult to achieve the desired color density.

[0056] (Organic solvents) The red coloring composition for color filters of the present invention contains an organic solvent.

[0057] Specifically, the above organic solvent is (at atmospheric pressure (1.013 × 10⁻⁶)). 2 These include ester-based organic solvents, ether-based organic solvents, ether-ester-based organic solvents, ketone-based organic solvents, aromatic hydrocarbon-based organic solvents, nitrogen-containing organic solvents, etc., with boiling points of 100-220°C at kPa. If the above-mentioned organic solvent contains a large amount of an organic solvent with a boiling point exceeding 220°C, when pre-baking a coating film coated with the red pigment dispersion composition for color filters, or the red pigment dispersion resist composition for color filters described later, the organic solvent may not evaporate sufficiently and may remain in the dried coating film, potentially reducing the heat resistance of the dried coating film. Furthermore, if the above-mentioned organic solvent contains a large amount of organic solvent with a boiling point below 100°C, it may become difficult to apply it evenly and uniformly, potentially resulting in a coating film with excellent surface smoothness.

[0058] The above organic solvents specifically 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, and propylene glycol. Examples include ether ester organic solvents such as 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, methyl-3-methoxybutylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyethyl acetate, ethyl hydroxyethyl acetate, 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 can be used individually or in combination of two or more types.

[0059] Among the above organic solvents, 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-methoxybutyl propionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, n-amyl formate, etc. are preferred in terms of solubility, dispersibility, and applicability, and propylene glycol monomethyl ether acetate is more preferred.

[0060] The content of the above-mentioned organic solvent is preferably 30 to 80% by mass, and more preferably 35 to 75% by mass, based on the total mass of the red pigment dispersion composition for color filters, in order to ensure good solubility of the alkali-soluble resin, pigment dispersibility, and coatability.

[0061] (Method for producing a red colored composition for color filters) The red coloring composition for color filters of the present invention can be obtained by adding the above-mentioned components, mixing them, and kneading them.

[0062] As for the method of mixing and kneading the above ingredients, for example, a bead mill, ready mill, ultrasonic homogenizer, high-pressure homogenizer, paint shaker, ball mill, roll mill, sand mill, sand grinder, Dino mill, Dispermat, SC mill, Nanomizer, etc., the ingredients can be kneaded using known methods.

[0063] <Red colored resist composition for color filters> The red colored resist composition for color filters of the present invention is obtained from the above-mentioned red colored composition for color filters. The red colored resist composition for color filters of the present invention can be obtained by adding an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, an organic solvent, and, if necessary, additives, in addition to the red colored resist composition for color filters of the present invention described above.

[0064] (Red coloring composition for color filters) The red colored resist composition for color filters of the present invention contains the above-described red colored composition for color filters of the present invention. The content of the red coloring composition for the color filter described above is preferably 30 to 80% by mass, and more preferably 40 to 75% by mass, based on the total mass of the red coloring resist composition for the color filter of the present invention.

[0065] (Alkali-soluble resin) The alkali-soluble resin mentioned above is not particularly limited, and conventionally used resins can be used. However, it is preferable that the resin acts as a binder for the coloring pigment and is soluble in the developing solution (preferably an alkaline developing solution) used in the developing process when manufacturing the color filter.

[0066] The alkali-soluble resin mentioned above may be either a random copolymer or a block copolymer. Among the alkali-soluble resins mentioned above, those having carboxyl groups are preferred, and a copolymer consisting of an ethylenically unsaturated monomer having one or more carboxyl groups and another copolymerizable ethylenically unsaturated monomer is more preferred.

[0067] Specifically, the alkali-soluble resins mentioned above 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 of monomers and oligomers 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. Furthermore, the alkali-soluble resin may have photopolymerizable functional groups.

[0068] The acid value of the alkali-soluble resin described above is preferably 5 to 250 mg KOH / g, more preferably 10 to 200 mg KOH / g, and even more preferably 60 to 150 mg KOH / g, from the viewpoint of development characteristics. In this invention, the above acid value is a theoretical acid value, which is an arithmetic value determined based on the ethylenically unsaturated monomer having a carboxyl group and its content.

[0069] The weight-average molecular weight of the alkali-soluble resin described above is usually preferably 1,000 to 100,000, more preferably 3,000 to 50,000, and even more preferably 7,000 to 20,000, from the viewpoint of developing characteristics and solubility in organic solvents. In this specification, the weight-average molecular weight of the alkali-soluble resin is the weight-average molecular weight on a polystyrene basis obtained based on GPC. The measurement can be performed using a Water2690 instrument (Waters Corporation) and a PLgel 5μm MIXED-D column (Agilent Technologies).

[0070] The content of the alkali-soluble resin is preferably 1 to 200 parts by mass, and more preferably 10 to 150 parts by mass, per 100 parts by mass of the coloring pigment. If the amount of alkali-soluble resin is less than 1 part by mass per 100 parts by mass of the coloring pigment, the development characteristics may deteriorate. On the other hand, if the amount of alkali-soluble resin exceeds 200 parts by mass per 100 parts by mass of the coloring pigment, the relative concentration of the colorant will decrease, making it difficult to achieve the desired color density as a thin film.

[0071] Preferably, the alkali-soluble resin described above does not contain any primary, secondary, or tertiary amino groups, nor does it contain any quaternary ammonium groups. Furthermore, it is more preferable that the material does not have a basic group.

[0072] (Photopolymerizable compound) Examples of the above-mentioned photopolymerizable compounds include monomers, oligomers, etc., that have one or more photopolymerizable unsaturated bonds in their molecule. A photopolymerizable unsaturated bond is an unsaturated bond that can polymerize through the action of radicals and cations generated when a photopolymerization initiator, described later, is decomposed by active energy rays such as ultraviolet light or electron beams.

[0073] Monomers having one of the above-mentioned photopolymerizable unsaturated bonds 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; and N,N-dimethylaminoethyl methacrylate and N,N-dimethylaminoethyl acrylate. Examples include aminoalkyl methacrylates or acrylates such as rilate; methacrylic acid esters or acrylic acid esters of polyalkylene glycol alkyl ethers such as diethylene glycol ethyl ether, triethylene glycol butyl ether, and dipropylene glycol methyl ether; methacrylic acid esters or acrylic acid esters of polyalkylene glycol aryl ethers such as hexaethylene glycol phenyl ether; isovonyl methacrylate or acrylate; glycerol methacrylate or acrylate; 2-hydroxyethyl methacrylate or acrylate, etc. In this specification, (meth)acrylate means acrylate and methacrylate.

[0074] Monomers having two or more of the above-mentioned photopolymerizable unsaturated bonds in their 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, and dipentaerythritol hexamethacrylate. Examples 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 individually or in combination of two or more.

[0075] The content of the above-mentioned photopolymerizable compound is preferably 0.5 to 20% by mass, and more preferably 1 to 10% by mass, based on the total mass of the red colored resist composition for color filters of the present invention.

[0076] (Photopolymerization initiator) The above-mentioned photopolymerization initiator is not particularly limited as long as it can generate radicals or cations when irradiated with active energy rays such as ultraviolet light or electron beams, for example, benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, benzyl, 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutylphenone, thiox Examples include santhon, 2-chlorothioxanthon, 1-hydroxycyclohexylphenyl ketone, t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chlor-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and triazine-based photopolymerization initiators. The above-mentioned photopolymerization initiators can be used individually or in combination of two or more.

[0077] The content of the above-mentioned photopolymerization initiator is preferably 0.1 to 5% by mass, and more preferably 0.5 to 3% by mass, based on the total mass of the red colored resist composition for color filters of the present invention.

[0078] (Organic solvents) As the above-mentioned organic solvent, any of the organic solvents described in the above-mentioned red coloring composition for color filters of the present invention can be appropriately selected and used.

[0079] The content of the above-mentioned organic solvent is preferably 1 to 40% by mass, and more preferably 5 to 35% by mass, based on the total mass of the red colored resist composition for color filters of the present invention.

[0080] (Other additives) The red colored resist composition for color filters of the present invention may contain additives to the extent that they do not impair the effects of the present invention. Examples of the above-mentioned additives include various additives such as thermal polymerization inhibitors, silane coupling agents, titanate coupling agents, ultraviolet absorbers, and antioxidants.

[0081] (Method for manufacturing a red colored resist composition for color filters) The method for producing the red colored resist composition for color filters of the present invention is not particularly limited, and can be obtained by mixing the above-mentioned materials by a known method and kneading them.

[0082] (Physical properties of red colored resist composition for color filters) The red colored resist composition for color filters of the present invention preferably has a viscosity of 8.5 mPa·s or less, more preferably 7.0 mPa·s or less, even more preferably 6.0 mPa·s or less, and particularly preferably 5.0 mPa·s or less. Having this viscosity allows for uniform application, resulting in a uniform thickness for the color filter. In this specification, viscosity refers to the viscosity at 25°C measured using an E-type viscometer (R100 type viscometer, model RE100L, manufactured by Toki Sangyo Co., Ltd.).

[0083] The red colored resist composition for color filters of the present invention preferably has a viscosity change rate [(viscosity after 1 week of storage - viscosity before storage) / (viscosity before storage)] of 10% or less after being placed in a glass bottle, sealed tightly, and stored at 60°C for one week. If the viscosity change rate is 10% or less, it has excellent storage stability and is less likely to deteriorate even when stored for a long period of time.

[0084] <Color Filter> The color filter of the present invention is formed from the above-mentioned red colored resist composition for color filters. The color filter of the present invention comprises a red filter segment, a green filter segment, and a blue filter segment, wherein the red filter segment is formed from the red colored resist composition for color filters of the present invention. The above-mentioned green filter segment and blue filter segment can be formed using known materials and methods. The color filter of the present invention can be used by appropriately selecting known methods such as printing or photolithography.

[0085] This invention makes it possible to suppress the occurrence of water unevenness during the manufacturing of color filters. Whether the occurrence of the above-mentioned water unevenness was suppressed can be observed by the following test.

[0086] The above-mentioned red colored resist composition for color filters is applied to a glass substrate (Corning 1737, manufactured by Corning) using a spin coater so that the thickness of the dried film is 2 μm, and then dried on a hot plate at 100°C for 3 minutes. Next, using an ultra-high pressure mercury lamp, the irradiation dose was 50 mJ / cm². 2 Ultraviolet light is irradiated in such a way. After exposure, a 0.5% by mass potassium hydroxide aqueous solution is sprayed onto the coating film for 60 seconds using a spin developer, and shower development is performed. Afterward, the exposed area was rinsed with pure water for 45 seconds, and then the moisture on the glass plate surface was removed by air blowing. The water unevenness (shading unevenness) of the coating film was observed using an optical microscope (magnification 100x). If no unevenness in color intensity is observed on the surface of the coating film when viewed with the above optical microscope (magnification 100x), it can be concluded that the occurrence of water unevenness has been suppressed.

[0087] <Display device> The display device of the present invention includes the above-mentioned color filter. The display device of the present invention is not particularly limited as long as it includes the color filter of the present invention as described above, and examples include known liquid crystal display devices and touch panels. [Examples]

[0088] 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 "mass%" and "parts" means "parts by mass".

[0089] The materials used in the manufacture of the red coloring composition for color filters are as follows:

[0090] <Coloring pigments> (PR179) CI Pigment Red 179 (PY139) CI Pigment Yellow 139 (PV29) CI Pigment Violet 29

[0091] <Pigment dispersant> (Pigment dispersant 1) tertiary amino group-containing acrylic block copolymer (pigment dispersant having a quaternary ammonium salt structure, quaternary conversion rate 15 mol%) (Pigment dispersant 2) tertiary amino group-containing acrylic block copolymer (pigment dispersant having a quaternary ammonium salt structure, quaternary conversion ratio 33 mol%) (Pigment dispersant 3) tertiary amino group-containing acrylic block copolymer (pigment dispersant having a quaternary ammonium salt structure, quaternary conversion rate 50 mol%) (Pigment dispersant 4) tertiary amino group-containing acrylic block copolymer (pigment dispersant without quaternary ammonium salt structure, quaternary conversion rate 0 mol%) The Grade 4 classification rate is based on the values ​​obtained according to the method described herein.

[0092] <Pigment Dispersant> (PR2S) 30 ml of concentrated sulfuric acid was placed in a 100 ml Erlenmeyer flask, and 10 g of CI Pigment Red 2 was added while stirring with a magnetic stirrer. The mixture was then 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 mixture was poured into this ice water and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed with water under reduced pressure, and the resulting solid was dried to prepare a sulfonic acid group-containing pigment dispersion aid (sulfonated CI Pigment Red 2, PR2S). (PY138S) By changing the pigment CI Pigment Red 2 in PR2S to the pigment CI Pigment Yellow 138, a sulfonic acid group-containing pigment dispersion aid (sulfonated CI Pigment Yellow 138, PY138S) was prepared.

[0093] <Resin> (Resin 1) 3 g of 2,2'-azobis(isobutyronitrile) and 50 g of PGMEA were placed in a 500 ml flask. Then, 28.3 g of methacrylic acid, 32.3 g of styrene, and 26.2 g of cyclohexyl methacrylate were added. The mixture was stirred at room temperature for a while, then the flask was purged with nitrogen, and the mixture was heated and stirred at 70°C for 5 hours. Next, 13.2 g of glycidyl methacrylate, 1 g of dimethylbenzylamine, 0.2 g of p-methoxyphenol, and 100 g of PGMEA were added to the obtained solution, and the mixture was heated and stirred at 90°C for 4 hours. Afterward, the solution was cooled to room temperature, and PGMEA was added to the resulting resin solution to obtain resin 1 (solid content concentration of 40% by mass). The double bond equivalent of resin 1 was 930 g / mol, and its weight-average molecular weight was 15,500. (Resin 2) 3 g of 2,2'-azobis(isobutyronitrile) and 50 g of PGMEA were placed in a 500 ml flask. Then, 40 g of methacrylic acid, 30 g of styrene, and 30 g of methyl methacrylate were added. The mixture was stirred at room temperature for a while, then the flask was purged with nitrogen, and the mixture was heated and stirred at 70°C for 5 hours. Next, 15 g of glycidyl methacrylate, 1 g of dimethylbenzylamine, 0.2 g of p-methoxyphenol, and 100 g of PGMEA were added to the obtained solution, and the mixture was heated and stirred at 90°C for 4 hours. The solution was then cooled to room temperature, and PGMEA was added to the resulting resin solution to obtain resin 2 (solid content concentration of 40% by mass). The double bond equivalent of resin 2 was 500 g / mol, and its weight-average molecular weight was 28,000. (Resin 3) 3 g of 2,2'-azobis(isobutyronitrile) and 50 g of PGMEA were placed in a 500 ml flask. Then, 16.8 g of methacrylic acid, 36.4 g of benzyl methacrylate, and 36.9 g of tricyclo[5.2.1.02,6]decane-8-yl methacrylate were added. The mixture was stirred at room temperature for a while, then the flask was purged with nitrogen, and the mixture was heated and stirred at 70°C for 5 hours. Next, 9.9 g of glycidyl methacrylate, 1 g of dimethylbenzylamine, 0.2 g of p-methoxyphenol, and 100 g of PGMEA were added to the obtained solution, and the mixture was heated and stirred at 90°C for 4 hours. The solution was then cooled to room temperature, and PGMEA was added to the resulting resin solution to obtain resin 3 (solid content concentration of 40% by mass). The double bond equivalent of resin 3 was 1450 g / mol, and its weight-average molecular weight was 13,000. (ZAH110) We used ZAH-110, an acrylic resin without double bonds, manufactured by Soken Chemical Co., Ltd. The double bond equivalent and weight-average molecular weight are those values ​​obtained according to the methods described herein. Furthermore, the mass of the resins listed in Table 1 refers to the solid content mass.

[0094] <Organic solvents> (PGMEA) Propylene glycol monomethyl ether acetate

[0095] <Manufacturing of red coloring composition for color filters> Various materials were mixed to obtain the compositions shown in Table 1, and kneaded in a ready mill (bead diameter: 0.2 nm, packing rate: 50%) for 60 minutes to obtain red coloring compositions 1 to 14 for color filters (also simply referred to as coloring compositions 1 to 14).

[0096] [Table 1]

[0097] (Example 1) <Manufacturing of Red Tinted Resist Composition 1 for Color Filters> 53.33% by mass of the prepared colored composition 1, 5.27% by mass of alkali-soluble resin (BMA / MAA copolymer, ZAH110, manufactured by Soken Chemical Co., Ltd.), 3.29% by mass of photopolymerizable compound (DPHA), 1.10% by mass of photopolymerization initiator (Irgacure 369), and 37.01% by mass of organic solvent (PGMEA) were added and uniformly mixed using a high-speed stirrer. The mixture was then filtered through a membrane filter with a pore size of 3 μm to prepare red pigment dispersion resist composition 1 for color filters (also simply called resist composition 1).

[0098] (Examples 2-11, Comparative Examples 1-3) <Manufacturing of Red Tinted Resist Compositions 2-14 for Color Filters> Resist compositions 2 to 14 were prepared in the same manner as in the production of resist composition 1, except that coloring composition 1 was replaced with coloring compositions 2 to 14.

[0099] (Viscosity measurement) The viscosity of resist compositions 1 to 14 was measured at 25°C using an E-type viscometer (R100 type viscometer, model RE100L, manufactured by Toki Sangyo Co., Ltd.). The results are shown in Table 2.

[0100] (dispersion stability) For each of the resist compositions 1 to 14, samples were taken into glass bottles, sealed tightly, and stored at 60°C for one week. The viscosity change rate [(viscosity after one week of storage - viscosity before storage) / (viscosity before storage)] was calculated. The results are shown in Table 2. ○: The viscosity change rate before and after storage is 10% or less. ×: Viscosity change rate before and after storage exceeds 10%

[0101] (Evaluation of water unevenness) Resist compositions 1 to 14 were applied to a glass substrate (Corning 1737, manufactured by Corning) using a spin coater so that the dried film thickness was 2 μm, and then dried on a hot plate at 100°C for 3 minutes. Next, using an ultra-high pressure mercury lamp, the irradiation dose was 50 mJ / cm². 2 Ultraviolet light was irradiated in this manner. After exposure, a 0.5% by mass potassium hydroxide aqueous solution was sprayed onto the coating film for 60 seconds using a spin developer, and shower development was performed. Afterward, the exposed area was rinsed with pure water for 45 seconds, and then the moisture on the glass plate surface was removed by air blowing. The water unevenness (shading unevenness) of the coating film was observed using an optical microscope (magnification 100x) and evaluated according to the following evaluation criteria. <Evaluation Criteria> ○: No unevenness in color intensity was observed on the surface of the coating. △: Slight variations in color intensity were observed on the surface of the coating. ×: Clear variations in color intensity and peeling were observed on the surface of the coating.

[0102] [Table 2]

[0103] The examples confirmed that a red colored composition for color filters can be obtained that contains a coloring pigment, a pigment dispersant, a pigment dispersion aid, a resin, and an organic solvent, wherein the coloring pigment contains CI Pigment Red 179, the pigment dispersant has a quaternary ammonium salt structure, and the resin contains an acrylic resin having a double bond, resulting in excellent dispersion stability and suppression of water unevenness during the manufacture of color filters. [Industrial applicability]

[0104] The present invention provides a red colored composition for color filters that exhibits excellent dispersion stability and can suppress the occurrence of water unevenness during the manufacturing of color filters. Therefore, it can be suitably used as a red colored resist composition for color filters used in liquid crystal display devices, touch panels, and the like.

Claims

1. It contains coloring pigments, pigment dispersants, pigment dispersing aids, resins, and organic solvents. The aforementioned coloring pigment consists of C.I. Pigment Red 179. The aforementioned pigment dispersant has a quaternary ammonium salt structure, The aforementioned resin is a red coloring composition for color filters containing an acrylic resin having a double bond.

2. The red coloring composition for color filters according to claim 1, wherein the pigment dispersant has a quaternization rate expressed as the number of quaternary ammonium salts relative to the total number of amines in the pigment dispersant of 15 to 50 mol%.

3. The red coloring composition for color filters according to claim 1 or 2, wherein the pigment dispersion aid is a sulfonate of C.I. Pigment Red 2 and / or a sulfonate of C.I. Pigment Yellow 138.

4. The red coloring composition for color filters according to any one of claims 1 to 3, wherein the amount of double bond equivalent contained in the acrylic resin having the double bond is 300 to 2000 g / mol.

5. A red colored resist composition for color filters obtained from the red colored composition for color filters according to any one of claims 1 to 4.

6. A color filter formed by the red colored resist composition for color filters described in claim 5.

7. A display device including the color filter described in claim 6.

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