Pigment composition, coloring composition for color filter, and color filter

Abstract

The present invention addresses the problem of providing: a pigment composition capable of expanding, in particular, the yellowish color gamut in a red pixel portion; a coloring composition for a color filter including the pigment composition; and a color filter.　Specifically, this pigment composition includes: at least one colorant selected from the group consisting of Solvent Yellow 79, Solvent Orange 56, Solvent Red 233, Solvent Red 160, Solvent Red 130, Solvent Yellow 21, Pigment Yellow 147, Solvent Orange 60, Solvent Orange 54, Solvent Yellow 82, Solvent Yellow 81, Solvent Yellow 88, and Solvent Red 195; and C.I. Pigment Red 177. This coloring composition for a color filter contains the pigment composition, a solvent, and a binder resin. This color filter has a pixel portion containing a pigment composition.

Description

Pigment composition, coloring composition for color filters, and color filter

[0001] The present invention relates to a pigment composition, a coloring composition for color filters containing the same, and a color filter having pixel portions containing the pigment composition.

[0002] A color filter is a component that converts white light from a backlight into red, green, and blue to achieve color display on a display. The color filter has a red pixel portion (R), a green pixel portion (G), and a blue pixel portion (B). Each of these pixel portions has a structure in which a thin film of synthetic resin with organic pigments dispersed therein is provided on a substrate, and the organic pigments used are red, green, and blue organic pigments. Among these pixel portions, red organic pigments used to form the red pixel portion are generally diketopyrrolopyrrole pigment (C.I. Pigment Red 254), diaminodianthraquinone pigment (C.I. Pigment Red 177), condensed azo pigment (C.I. Pigment Red 242), or azo pigment (C.I. Pigment Red 269). Yellow organic pigments such as isoindoline pigment (C.I. Pigment Yellow 139) and nickel azo pigment (C.I. Pigment Yellow 150) are used in combination with these pigments for color matching, if necessary.

[0003] Among these red organic pigments, C.I. Pigment Red 254, a yellowish diketopyrrolopyrrole red pigment, has high brightness but suffers from the problem of low contrast.

[0004] On the other hand, C.I. Pigment Red 177, a bluish diaminoanthraquinone pigment, has been used as a complementary color to compensate for the contrast of C.I. Pigment Red 254. However, when the content of the diaminoanthraquinone pigment, which has a bluish hue, is increased, there is a problem that it does not match the target hue, and achieving both hue adjustment and high contrast is considered an issue.

[0005] Examples of coloring compositions for color filters used in the above-described red pixel portion include Patent Documents 1 and 2 listed below. Patent Document 1 describes a coloring composition for color filters containing a colorant, a metal complex compound, a binder resin, and an organic solvent, wherein the colorant contains a specific naphthol azo pigment and a metal complex compound having a specific central metal. Patent Document 2 describes a red pigment composition for color filters, characterized in that it contains, by mass, more than 10 parts to 20 parts of phthalimide alkylated quinacridone per 100 parts of a diketopyrrolopyrrole pigment, and has an average primary particle diameter of 10 to 30 nm.

[0006] JP 2016-114940 A Patent No. 6089710 A

[0007] In Patent Document 1, a metal complex dye is used to improve contrast, but no effect of expanding the color gamut is observed. In Patent Document 2, Pigment Red 254 is used as a yellowish red pigment, but a micronization process is required to achieve high contrast. In other words, in order to expand the color gamut of a red colorant in the yellowish direction, it is thought that the skeleton of the pigment itself needs to be changed, such as by replacing C.I. Pigment Red 177 with Pigment Red 254 or Pigment Red 242. In other prior art besides Patent Document 1, high-contrast C.I. Pigment Red 177 has been used as a red colorant for color filters, but as mentioned above, there is a problem in that the desired color gamut cannot be expressed due to the lack of yellowness.

[0008] Therefore, an object of the present invention is to provide a pigment composition that can particularly expand the yellowish color gamut in a red pixel portion when containing C.I. Pigment Red 177, which has excellent contrast and heat resistance, and a color filter containing the same.

[0009] As a result of investigations, the present inventors have found that the yellowish color gamut, particularly in red pixel portions, can be expanded by combining C.I. Pigment Red 177 with a specific colorant. The yellowish color gamut in this invention refers to a color gamut in which the x value at y = 0.313 is smaller than 0.68586 in chromaticity coordinates indicated by x and y, measured with Illuminant C for a color filter prepared by mixing a pigment composition comprising C.I. Pigment Red 177 and a specific colorant with Pigment Yellow 139 in a specific ratio. In this invention, it is believed that the insufficient absorption on the short wavelength side of C.I. Pigment Red 177 can be compensated for by adding a specific colorant, thereby expanding the yellowish color gamut.

[0010] That is, the present invention is as follows. [1] A pigment composition containing at least one colorant selected from the group consisting of Solvent Yellow 79, Solvent Orange 56, Solvent Red 233, Solvent Red 160, Solvent Red 130, Solvent Yellow 21, Pigment Yellow 147, Solvent Orange 60, Solvent Orange 54, Solvent Yellow 82, Solvent Yellow 81, Solvent Yellow 88, and Solvent Red 195, and C.I. Pigment Red 177. [2] A coloring composition for color filters, containing the pigment composition according to [1], a solvent, and a binder resin. [3] A color filter having a pixel portion containing the pigment composition according to [1].

[0011] The pigment composition of the present invention can expand the yellowish color gamut, particularly in red pixel portions, while maintaining contrast, and can widen the range that can be expressed by chromaticity x and y. Therefore, it is useful as a coloring composition for color filters for producing red pixel portions in color filters.

[0012] 1 is a graph plotting chromaticity x and y values ​​measured with a C light source in a characteristic evaluation of a color filter according to an example.

[0013] [Pigment composition] The pigment composition of the present invention comprises at least one colorant selected from the group consisting of Solvent Yellow 79 (SO79), Solvent Orange 56 (SO56), Solvent Red 233 (SR233), Solvent Red 160 (SR160), Solvent Red 130 (SR130), Solvent Yellow 21 (SY21), Pigment Yellow 147 (PY147), Solvent Orange 60 (SO60), Solvent Orange 54 (SO54), Solvent Yellow 82 (SY82), Solvent Yellow 81 (SY81), Solvent Yellow 88 (SY88), and Solvent Red 195 (SR195), and an anthraquinone pigment, C.I. Pigment Red 177 (PR177). The pigment composition of the present invention is not particularly limited as long as it contains the above-mentioned colorant and PR 177, and may contain other dyes or pigments. The above-mentioned colorants may be used alone or in combination of two or more.

[0014] It is preferable that PR177 used in the present invention be micronized before use, but the micronization method is not particularly limited, and for example, wet milling, dry milling, or solution-precipitation can all be used. The primary particle diameter of the micronized pigment is preferably 20 nm or more because it allows for good dispersion in the colorant carrier. Furthermore, it is preferably 100 nm or less because it allows for the formation of a color filter with a high contrast ratio. A particularly preferred range is 25 to 85 nm. When micronizing PR177, a resin can be added as needed. Examples of resins include natural resins, modified natural resins, synthetic resins, and synthetic resins modified with natural resins.

[0015] Among the above colorants, Solvent Yellow 79, Solvent Orange 56, Solvent Red 233, Solvent Red 160, Solvent Red 130, Solvent Yellow 21, Pigment Yellow 147, and Solvent Orange 60 are preferred because they have a significant effect of expanding the yellow color gamut, and Solvent Yellow 79 is particularly preferred.

[0016] The colorant is preferably soluble at room temperature in an organic solvent commonly used in the production of color filters, such as propylene glycol monomethyl ether acetate. Furthermore, it is more preferable that the colorant be one that dissolves in the colorant carrier when the coating film is heated at 230° C. for 1 hour during the production of the color filter coating film. By using such a dye with good solubility, a coloring composition for color filters having excellent brightness and contrast can be obtained.

[0017] When a color gamut close to the DCI standard is desired, the proportion of the colorant (total when two or more types are included) is preferably 0.5 to 8% by mass, or 2 to 8 parts by mass. When a more yellowish color gamut (for example, sRGB standard) is desired, the proportion of the dye is, for example, 10 to 90% by mass, or 15 to 25% by mass.

[0018] The pigment composition of the present invention may contain a red organic pigment, a blue organic pigment, or a yellow organic pigment other than PR177. Examples of red organic pigments other than PR177 include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 50:1, 52:1, 52:2, 53, 53:1, 53:2, 53:3, 57, 57: 1, 57:2, 58:4, 60, 63, 63:1, 63:2, 64, 64:1, 68, 69, 81, 81:1, 81:2, 81:3, 81:4, 83, 88, 90:1, 101, 101:1, 104, 108, 108:1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151 , 166, 168, 169, 170, 172, 173, 174, 175, 176, 178, 179, 181, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 216, 220, 221, 224, 230, 231, 232, 233, 234 5, 236, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, and 276.

[0019] Examples of blue organic pigments include C.I. Pigment Blue 1, 1:2, 9, 14, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 19, 25, 26, 27, 28, 29, 33, 35, 36, 56, 56:1, 60, 61, 61:1, 62, 63, 64, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, 79, and 80.

[0020] Examples of yellow organic pigments include C.I. Pigment Yellow 1, 1:1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 41, 42, 43, 48, 53, 55, 61, 62, 62:1, 63, 65, 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116, 117, 119, 120, 126, 127, 127:1, 128, 129, 133, 134, 136, 138, 139, 142, 148, 150, 151, 153, 154, 155, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 172, 173, 174, 175, 176, 180, 181, 182, 183, 184, 185, 188, 189, 190, 191, 191:1, 192, 193, 194, 195, 196, 197, 198, 199, 200, 202, 203, 204, 205, 206, 207, 208, 229.

[0021] These red organic pigments, blue organic pigments, and yellow organic pigments other than PR177 can be used to the extent that the effects of the present invention are not impaired, but the proportion of such pigments in the pigment composition of the present invention is, for example, 20 mass % or less, and preferably 10 mass % or less.

[0022] Dyes other than the dyes exemplified as the colorant may also be used. Examples of such dyes include red dyes such as Solvent Red 122, Solvent Red 52, Solvent Red 135, Solvent Red 225, Solvent Red 146, Solvent Red 119, Solvent Red 109, Solvent Red 111, Solvent Red 124, Solvent Red 149, Solvent Red 150, Solvent Red 168, Solvent Red 169, Solvent Red 172, Solvent Red 179, Solvent Red 196, Solvent Red 197, Solvent Red 207, Solvent Red 222, Solvent Red 227, Solvent Red 23, Solvent Red 24, Solvent Red 25, Solvent Red 27, Solvent Red 3, and Solvent Red 40. Solvent Red 312, Solvent Red 313, Solvent Red 49, and Solvent Red 8. Examples of orange dyes include Solvent Orange 99, Solvent Orange 116, Solvent Orange 107, Solvent Orange 14, Solvent Orange 3, Solvent Orange 62, Solvent Orange 63, and Solvent Orange 86.Examples of yellow dyes include Solvent Yellow 114, Solvent Yellow 131, Solvent Yellow 135, Solvent Yellow 14, Solvent Yellow 157, Solvent Yellow 16, Solvent Yellow 160, Solvent Yellow 163, Solvent Yellow 167, Solvent Yellow 176, Solvent Yellow 179, Solvent Yellow 185, Solvent Yellow 189, Solvent Yellow 2, Solvent Yellow 33, Solvent Yellow 43, Solvent Yellow 44, Solvent Yellow 56, Solvent Yellow 65, Solvent Yellow 85, Solvent Yellow 93, and Solvent Yellow 98. Examples of green dyes include Solvent Green 28, Solvent Green 3, Solvent Green 5, and Solvent Green 7.

[0023] Dyes other than those exemplified as the colorant above can be used within a range that does not impair the effects of the present invention, but the proportion of such dyes in the pigment composition of the present invention is, for example, 20% by mass or less, preferably 10% by mass or less.

[0024] In the pigment composition of the present invention, various derivatives may be used in combination with the pigment and dye, if necessary, to improve dispersibility. Examples of substituents on the pigment and dye skeleton in such derivatives include sulfonic acid groups, sulfonamide groups and quaternary salts thereof, phthalimidomethyl groups, dialkylaminoalkyl groups, hydroxyl groups, carboxyl groups, and amide groups, which are bonded to the pigment skeleton directly or via alkyl groups, aryl groups, heterocyclic groups, etc.

[0025] The pigment composition of the present invention may be prepared by mixing and stirring (dry blending) powders of a pigment containing PR177 and a colorant such as Solvent Yellow 79, or by mixing the pigment and the colorant in the form of their own dispersions.

[0026] [Coloring composition for color filter] The coloring composition for color filter of the present invention contains the pigment composition of the present invention, a solvent, and a binder resin. In addition to the above, the coloring composition may also contain a resin-based dispersant, etc., as necessary.

[0027] As the solvent, an organic solvent is usually used. Examples of such organic solvents include diisopropyl ether, mineral spirits, n-pentane, amyl ether, ethyl caprylate, n-hexane, diethyl ether, isoprene, ethyl isobutyl ether, butyl stearate, n-octane, Balsol #2, Apco #18 solvent, diisobutylene, amyl acetate, butyl acetate, Apco thinner, butyl ether, diisobutyl ketone, methylcyclohexene, methyl nonyl ketone, propyl ether, dodecane, Socal Solvent No. 1 and No. 2, amyl formate, dihexyl ether, diisopropyl ketone, Solvesso #150, (n,sec,t-) Butyl acetate, hexene, Shell TS28 Solvent, butyl chloride, ethyl amyl ketone, ethyl benzoate, amyl chloride, ethylene glycol diethyl ether, ethyl orthoformate, methoxymethyl pentanone, methyl butyl ketone, methyl hexyl ketone, methyl isobutyrate, benzonitrile, ethyl propionate, methyl cellosolve acetate, methyl isoamyl ketone, n-amyl methyl ketone (2-heptanone), methyl isobutyl ketone, propyl acetate, amyl acetate, amyl formate, bicyclohexyl, diethylene glycol monoethyl ether acetate, dipentene, methoxymethyl pentanol, methyl amyl ketone, methyl isopropyl ketone, propyl propionate, propylene glycol t-butyl ether, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, carbitol, cyclohexanone, ethyl acetate, propylene glycol, propylene glycol monomethyl ether Examples of suitable esters include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, 3-methoxypropionic acid, 3-ethoxypropionic acid, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, diglyme, ethylene glycol acetate, ethyl carbitol, butyl carbitol, ethylene glycol monobutyl ether, propylene glycol t-butyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol, tripropylene glycol methyl ether, and ethyl lactate.

[0028] To prepare the colored composition of the present invention, these solvents may be used alone or in combination of two or more. In the colored composition, the solvent is used in an amount of usually 500 to 900 parts by mass, preferably 600 to 800 parts by mass, per 100 parts by mass of the pigment composition.

[0029] Examples of the binder resin include thermoplastic resins and thermosetting resins. The resin is preferably a transparent resin having a spectral transmittance of preferably 80% or more, more preferably 95% or more, over the entire wavelength range of 400 to 700 nm in the visible light region.

[0030] Examples of the thermoplastic resin include acrylic resin, butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, polyester resin, vinyl resin, alkyd resin, polystyrene resin, polyamide resin, rubber resin, cyclized rubber resin, cellulose, polyethylene (HDPE, LDPE), polybutadiene, and polyimide resin. Examples of the thermosetting resin include epoxy resin, benzoguanamine resin, rosin-modified maleic acid resin, rosin-modified fumaric acid resin, melamine resin, urea resin, and phenol resin.

[0031] The proportion of the binder resin is, for example, 30 to 500 parts by mass, and preferably 40 to 400 parts by mass, per 100 parts by mass of the pigment composition.

[0032] When dispersing the pigment composition in a solvent, a resin-based dispersant may be used to improve dispersibility and dispersion stability. This resin-based dispersant functions by bonding to the organic pigment via an anchor moiety, with the compatible moiety extending into the dispersion medium to form a dispersion. It is different from the alkali-soluble resin and photopolymerizable monomer used in preparing the photosensitive composition described below. In addition to the resin-based dispersant, the pigment composition may further contain rosin, surfactant, etc. These components may or may not be surface-treated on the pigment. The pigment surface may be treated by known methods such as rosin treatment, surfactant treatment, solvent treatment, and resin treatment.

[0033] Examples of the resin-based dispersant include those having a polymer chain, such as polyurethane resin, polyethyleneimine, polyoxyethylene glycol diester, acrylic resin, polyester resin, etc. Among these, polyester resin-based dispersants and / or acrylic resin-based dispersants are preferred in terms of dispersibility, heat resistance, and light resistance.

[0034] Specific examples of various resin-based dispersants include, by trade name, AJISPER (manufactured by Ajinomoto Fine-Techno Co., Ltd.), EFKA (manufactured by BASF), DISPERBYK (manufactured by BYK-Chemie), BYKLPN (manufactured by BYK-Chemie), DISPARLON (manufactured by Kusumoto Chemicals Co., Ltd.), SOLSPERSE (manufactured by Lubrizol), KP (manufactured by Shin-Etsu Chemical Co., Ltd.), and POLYFLOW (manufactured by Kyoeisha Chemical Co., Ltd.) These dispersants may be used alone, or two or more types may be used in any combination and ratio.

[0035] The proportion of the resinous dispersant is, for example, 60 to 90 parts by mass, and preferably 80 to 90 parts by mass, per 100 parts by mass of the pigment composition.

[0036] The coloring composition can be prepared by stirring and mixing the pigment composition of the present invention, a solvent, and a resin-based dispersant added as needed. If necessary, the composition can also be prepared by shaking for a required time in the presence of various grinding media such as beads or rods, and then dispersing the media by filtration or the like. The coloring composition of the present invention is used for the red pixel portion of a color filter. To obtain a red pixel of a preferred color tone (tone adjustment), it is preferable to mix a coloring composition containing a yellow pigment such as Pigment Yellow 139 with the coloring composition of the present invention.

[0037] A photosensitive composition is usually prepared using the coloring composition to form a red pixel portion by photolithography or the like. The photosensitive composition contains, for example, the coloring composition, an alkali-soluble resin, a photopolymerizable monomer, and a photopolymerization initiator.

[0038] Examples of the alkali-soluble resin include resins containing a carboxyl group or an acidic hydroxyl group, such as novolac-type phenolic resins, (meth)acrylic acid alkyl ester (meth)acrylic acid copolymers, styrene (meth)acrylic acid copolymers, and styrene-maleic acid copolymers.

[0039] Examples of the photopolymerizable monomer include bifunctional monomers such as 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, bis[(meth)acryloxyethoxy]bisphenol A, and 3-methylpentanediol di(meth)acrylate; polyfunctional monomers having relatively small molecular weights such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate; and polyfunctional monomers having relatively large molecular weights such as polyester acrylate, polyurethane acrylate, and polyether acrylate.

[0040] Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketanol, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis(4'-azidobenzal)-2-propane, 1,3-bis(4-azidobenzal)-2-propane-2'-sulfonic acid, 4,4'-diazidostilbene-2,2'-disulfonic acid, ethanone, and 1-[9-ethyl-6-[2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxybenzoyl]-9,H-carbazol-3-yl]-1-(O-acetyloxime).

[0041] The photosensitive composition for forming pixel portions can be obtained by adding 3 to 20 parts of a total of an alkali-soluble resin and a photopolymerizable monomer per 1 part of the pigment composition of the present invention, 0.05 to 3 parts of a photopolymerization initiator per 1 part of the photopolymerizable monomer, and, if necessary, further adding the solvent used in preparing the coloring composition described above, and stirring and dispersing the mixture to form a uniform photosensitive composition.

[0042] [Color filter] The color filter of the present invention has a pixel portion containing the pigment composition of the present invention. The color filter of the present invention can be produced by a known, commonly used method using a photosensitive composition containing the coloring composition of the present invention.

[0043] A typical method for producing a color filter is photolithography, in which the red pixel portion is formed by applying the photosensitive composition containing the coloring composition of the present invention to a transparent substrate such as glass for a color filter, drying by heating (prebaking), and then irradiating with ultraviolet light through a photomask to perform pattern exposure to cure the photocurable compound in the areas corresponding to the red pixel portion, and then developing the unexposed areas with a developer to remove the non-pixel portions and fix the pixel portion to the transparent substrate. This method forms a red pixel portion consisting of a cured colored film of the photosensitive composition on the transparent substrate. The green (G) and blue (B) pixel portions can also be similarly produced in the above manner from photosensitive compositions prepared from organic pigments of the respective colors.

[0044] Methods for applying the photosensitive composition onto a transparent substrate include spin coating, roll coating, slit coating, ink jet printing, and the like, in addition to photolithography.

[0045] Drying conditions for the photosensitive composition coating on the transparent substrate vary depending on the type and blending ratio of each component, but are typically 50 to 150°C for approximately 1 to 15 minutes. This heat treatment is generally referred to as prebaking. Furthermore, ultraviolet light or visible light in the wavelength range of 200 to 500 nm is preferably used as the light source used to photocure the photosensitive composition. Various light sources emitting light in this wavelength range can be used. Examples of development methods that can be used with various light sources emitting light in this wavelength range include the puddle method, dipping method, and spray method. After exposure and development of the photosensitive composition, the transparent substrate on which the required color pixel portions have been formed is washed with water and dried. The resulting color filter is then postbaked at 90 to 280°C for a predetermined time using a heating device such as a hot plate or oven to remove volatile components from the colored coating and simultaneously thermally cure any unreacted photocurable compounds remaining in the cured colored film of the photosensitive composition, completing the color filter.

[0046] A color filter can be obtained by forming a coating film for the pixel portion by the above-mentioned method, sealing a liquid crystal material between a pair of parallel transparent electrodes, dividing the transparent electrodes into discontinuous fine sections, and providing color filter colored pixel portions selected from one of red (R), green (G), and blue (B) in an alternating pattern in each of the fine sections divided into a grid pattern by a black matrix on the transparent electrodes, or by forming color filter colored pixel portions on a substrate and then providing a transparent electrode.

[0047] The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. In these examples, "parts" means "parts by mass."

[0048] [Preparation of Pigment Compositions] Pigment compositions 1 to 20 were obtained by mixing and stirring C.I. Pigment Red 177 and the colorants shown in Table 1 below in the ratios shown in Table 1. Note that in pigment composition 20, only C.I. Pigment Red 177 was used, and no colorant was used.

[0049]

[0050] [Preparation of colored composition for evaluating color filter characteristics] The pigment composition prepared in Table 1 above and C.I. Pigment Yellow 139, the pigment composition: C.I. Pigment Yellow 139 blending ratio was 9:1 to 1:9 parts, 1.82 parts of a mixture mixed, 3.63 parts of DISPERBYK LPN-21116 (manufactured by BYK-Chemie Co., Ltd.), 12.75 parts of propylene glycol monomethyl ether acetate was mixed, 0.3 to 0.4 mmφ zirconia beads were added, and the mixture was dispersed for 3 hours with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.). 4.44 parts of the obtained dispersion and 0.95 parts of Unidic ZL-295 (manufactured by DIC Corporation) were placed in a glass bottle and shaken to obtain the colored compositions of Examples 1 to 19 and Comparative Example 1.

[0051] [Preparation of Color Filter for Evaluation] The colored composition obtained above was applied to a soda glass substrate using a spin coater, dried at 90°C for 3 minutes, allowed to cool, and then heated (post-baked) at 230°C for 1 hour to prepare a coated film substrate. By adjusting the rotation speed of the spin coater, a coating film with a film thickness of approximately 3.5 μm after drying was obtained. The film thickness was measured using a white light interference microscope (VS1330) manufactured by Hitachi High-Tech Science Corporation. In this way, multiple color filters for evaluation were prepared, each having a different composition ratio of the pigment composition and C.I. Pigment Yellow 139.

[0052] [Evaluation of Color Filter Characteristics: Chromaticity x at Specific Chromaticity y] Figure 1 shows a plot of the chromaticity x and y values ​​measured using a spectrophotometer (U3900 manufactured by Hitachi High-Tech Science Corporation) with Illuminant C for the evaluation color filters prepared above. Figure 1 shows data for Examples 1 to 19 and Comparative Example 1. Table 2 below shows the calculated value of x at which chromaticity y = 0.313. By comparing the chromaticity x values ​​at specific chromaticity y, the expansion of the color gamut relative to C.I. Pigment Red 177 was evaluated by the chromaticity difference Δx. A negative value of Δx (PR177 ratio) indicates that the chromaticity expands toward yellow.

[0053]

[0054] In Examples 1 to 19 shown in Table 1 above, Δx (PR177 ratio) was a negative value in all cases, and it can be seen that the color gamut expanded in the yellowish direction. In particular, a significant effect of expanding the color gamut was observed in the combination of PR177 and SY79 in Example 1.

[0055] (Preparation of Coloring Composition for Contrast Evaluation) 1.82 parts of the pigment composition prepared at the pigment ratio shown in Table 1 above, 3.63 parts of BYK LPN-21116 (manufactured by BYK-Chemie Co., Ltd.), and 12.75 parts of propylene glycol monomethyl ether acetate were mixed, and zirconia beads of 0.3 to 0.4 mmφ were added, followed by dispersion for 3 hours using a paint conditioner (manufactured by Toyo Seiki Co., Ltd.). 4.44 parts of the obtained dispersion and 0.95 parts of Unidic ZL-295 (manufactured by DIC Corporation) were placed in a glass bottle and shaken to obtain the coloring compositions of Examples 2-1 to 2-14 and Comparative Example 2-1.

[0056] (Evaluation of contrast of pigment composition) The above colored composition was applied to a soda glass substrate using a spin coater so that the dry film thickness was 3.5 μm, and then dried at 90° C. for 3 minutes and allowed to cool. This was followed by heating (post-baking) at 230° C. for 1 hour to prepare a coated film substrate. The contrast of the colored film in the evaluation color filter prepared above was measured using a contrast tester CT-1 manufactured by Tsubosaka Electric Co., Ltd. The contrast after post-baking (PB) is shown in Table 3 below.

[0057]

[0058] (Preparation of Coloring Composition for Brightness Evaluation) 1.82 parts of a mixture prepared by mixing the pigment composition prepared in Table 1 above and C.I. Pigment Yellow 139 in the ratio shown in Table 4 below, 3.63 parts of DISPERBYK LPN-21116 (manufactured by BYK-Chemie Co., Ltd.), and 12.75 parts of propylene glycol monomethyl ether acetate were mixed, and zirconia beads of 0.3 to 0.4 mmφ were added, and the mixture was dispersed for 3 hours using a paint conditioner (manufactured by Toyo Seiki Co., Ltd.). 4.44 parts of the obtained dispersion and 0.95 parts of Unidic ZL-295 (manufactured by DIC Corporation) were placed in a glass bottle and shaken to obtain the coloring compositions of Examples 3-1 to 3-9 and Comparative Example 3-1.

[0059] (Evaluation of Brightness of Pigment Composition) The colored composition obtained above was applied to a soda glass substrate using a spin coater, dried at 90°C for 3 minutes, allowed to cool, and then heated (post-baked) at 230°C for 1 hour to prepare a coated film substrate. The film thickness after drying was adjusted by adjusting the rotation speed of the spin coater to obtain a coated film with a chromaticity (x, y) = (0.679, 0.313). The evaluated chromaticity x and y were those described in

[0150] of Japanese Patent No. 7046777. The spectrum of the obtained coated film was measured using a colorimeter (U-3900 manufactured by Hitachi High-Tech Science Corporation), and the tristimulus value Y in the CIE XYZ color system was measured as luminance Y using the color matching function of Illuminant C. A larger Y value indicates higher luminance. The luminance Y after post-baking (PB) is shown in Table 4.

[0060]

[0061] Examples 2-1 to 2-14, whose contrast values ​​are shown in Table 3 above, i.e., combinations of PR177 with SO56, SR233, SR160, SR130, SY21, SY82, SO54, SY81, or SY79, have a yellowish tint and high contrast, and are therefore suitable for LCD (liquid crystal display) applications, for example.Furthermore, Examples 3-1 to 3-9, whose brightness values ​​are shown in Table 4 above, i.e., combinations of PR177 with SO56, SR233, SR160, SY21, SO60, SY81, SR195, or SY79, have a yellowish tint and high brightness, and are therefore suitable for OLED (organic light-emitting diode) applications, for example.

Claims

1. A pigment composition comprising a pigment and a colorant, The pigment comprises C.I. Pigment Red 177; the colorant is selected from the group consisting of Solvent Yellow 79, Solvent Orange 56, Solvent Red 233, Solvent Red 160, Solvent Red 130, Solvent Yellow 21, Pigment Yellow 147, Solvent Orange 60, Solvent Orange 54, Solvent Yellow 82, Solvent Yellow 81, Solvent Yellow 88, and Solvent Red 195; The pigment composition has a content of the colorant of 2 to 25% by mass.

2. In the pigment, the ratio of pigments other than C.I. Pigment Red 177 is 20 mass% or less, 2. The pigment composition according to claim 1, wherein the pigment other than C.I. Pigment Red 177 is selected from the group consisting of C.I. Pigment Red 242, C.I. Pigment Red 254, C.I. Pigment Yellow 139, and C.I. Pigment Yellow 150.

3. A coloring composition for color filters, comprising the pigment composition according to claim 1 or 2, a solvent, and a binder resin.

4. A color filter having a pixel portion containing the pigment composition according to claim 1 or 2.