Pigment composition, coloring composition for color filters, 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

[Technical field]

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

[0002] A color filter is a component that realizes color display on a display by converting the white light of a backlight into red, green, and blue. The color filter has a red pixel section (R), a green pixel section (G), and a blue pixel section (B). Each of these pixel sections 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. Of these pixel portions, red organic pigments for forming red pixel portions are generally diketopyrrolopyrrole pigment (CI Pigment Red 254), diaminodianthraquinone pigment (CI Pigment Red 177), condensed azo pigment (CI Pigment Red 242), and azo pigment (CI Pigment Red 269). If necessary, yellow organic pigments such as isoindoline pigment (CI Pigment Yellow 139) and nickel azo pigment (CI Pigment Yellow 150) are used in combination for color adjustment.

[0003] Among these red organic pigments, CI Pigment Red 254, a yellowish diketopyrrolopyrrole-based red pigment, has high luminance but suffers from a problem of low contrast.

[0004] On the other hand, CI Pigment Red 177, a bluish diaminoanthraquinone pigment, has been used as a complementary color to complement the contrast of CI Pigment Red 254. However, when the content of the bluish diaminoanthraquinone pigment is high, there is a problem that it does not match the target hue, and the challenge is to achieve both hue adjustment and high contrast.

[0005] Examples of color filter coloring compositions used in the above-mentioned red pixel portion include the following Patent Documents 1 and 2. Patent Document 1 describes a color filter coloring composition containing a colorant, a metal complex compound, a binder resin, and an organic solvent, in which 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, which contains more than 10 parts to 20 parts of phthalimide alkylated quinacridone per 100 parts of diketopyrrolopyrrole pigment in mass conversion, and has an average primary particle diameter of 10 to 30 nm. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-114940 A [Patent Document 2] Patent No. 6089710 Summary of the Invention [Problem to be solved by the invention]

[0007] In the above Patent Document 1, a metal complex dye is used for the purpose of improving contrast, but no effect of expanding the color gamut is observed. In the above Patent Document 2, Pigment Red 254 is used as a yellowish red pigment, but a fine-graining process is required to increase the contrast. That is, in order to expand the color gamut of a red colorant in the yellowish direction, it is considered necessary to change the pigment skeleton itself, such as replacing CI Pigment Red 177 with Pigment Red 254 or Pigment Red 242. In other conventional technologies other than Patent Document 1, high-contrast CI Pigment Red 177 has been used as a red colorant for color filters, but as mentioned above, there is a problem 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 it contains CI Pigment Red 177, which has excellent contrast and heat resistance, and a color filter coloring composition for color filters containing the same. [Means for solving the problem]

[0009] As a result of investigation, the present inventors have found that the yellowish color gamut can be expanded, particularly in red pixel parts, by combining CI Pigment Red 177 with a specific colorant. The yellowish color gamut in the present invention refers to a color gamut in which the value of x at y=0.313 is smaller than 0.68586 in chromaticity coordinates indicated by chromaticity x and y measured with a C light source for a color filter produced by mixing a pigment composition obtained by mixing Pigment Red 177 with a specific colorant and Pigment Yellow 139 in a specific ratio. In the present invention, it is considered that the insufficient absorption on the short wavelength side in 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 comprising 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 CI Pigment Red 177. [2] A coloring composition for color filters, comprising 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]. Effect of the Invention

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

[0012] [Figure 1] 1 is a graph plotting chromaticity x, y values ​​measured with a C light source in an evaluation of the characteristics of a color filter according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] [Pigment composition] The pigment composition of the present invention contains 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 CI Pigment Red 177 (PR177), which is an anthraquinone pigment. The pigment composition of the present invention is not particularly limited as long as it contains the above-mentioned colorant and PR177, 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 the PR177 used in the present invention is finely divided before use, but the method of finely dividing is not particularly limited, and any of wet grinding, dry grinding, and dissolution precipitation methods can be used. The primary particle size of the finely divided pigment is preferably 20 nm or more because it is easily dispersed in the colorant carrier. In addition, it is preferably 100 nm or less because it is possible to form a color filter with a high contrast ratio. The particularly preferred range is 25 to 85 nm. When finely dividing PR177, a resin can be added as necessary. Examples of the resin include natural resins, modified natural resins, synthetic resins, and synthetic resins modified with natural resins.

[0015] As the colorant, among them, 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 large effect of expanding the yellow color range, and Solvent Yellow 79 is particularly preferred.

[0016] The colorant is preferably soluble at room temperature in an organic solvent commonly used in color filter production, such as propylene glycol monomethyl ether acetate. Furthermore, it is more preferable that the colorant is soluble in the colorant carrier when the coating film is heated at 230° C. for 1 hour during the preparation 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] If a color gamut close to the DCI standard is desired, the ratio of the above colorants (total if two or more types are included) should be 0.5 to 8 mass%, 2 to 8 mass%. % In the case where a more yellowish color gamut (for example, sRGB standard) is desired, the ratio of the above dye is, for example, 10 to 90 mass %, 15 to 25 mass % is preferable.

[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 CI 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, 235, 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] Blue organic pigments include, for example, CI 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, 80.

[0020] Examples of yellow organic pigments include CI 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, and 229.

[0021] These red organic pigments, blue organic pigments, and yellow organic pigments other than PR177 can be used within a range that does not impair the effects of the present invention, but the proportion of these pigments in the pigment composition of the present invention is, for example, 20 mass % or less, preferably 10 mass % or less.

[0022] Dyes other than those listed as the colorant may 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, Solvent Red 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 above colorants 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 mass % or less, and preferably 10 mass % or less.

[0024] In the pigment composition of the present invention, in addition to the pigment or dye, various derivatives may be used in combination as necessary to improve dispersibility. Examples of the substituents on the pigment or dye skeleton in such derivatives include sulfonic acid groups, sulfonamide groups and quaternary salts thereof, phthalimidomethyl groups, dialkylaminoalkyl groups, hydroxyl groups, carboxyl groups, amide groups, etc., 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 including PR177 and a colorant such as Solvent Yellow 79, or the pigment and the colorant may be mixed in a state in which each is a dispersion.

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

[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, Barsol #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, Amylformate, 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 ter, 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 coloring composition of the present invention, these solvents may be used alone or in combination of two or more. In the coloring composition, the solvent is usually used in an amount of 500 to 900 parts by mass, preferably 600 to 800 parts by mass, per 100 parts by mass of the pigment composition.

[0029] The binder resin may be, for example, a thermoplastic resin or a thermosetting resin. The resin is preferably a transparent resin having a spectral transmittance of preferably 80% or more, more preferably 95% or more, in 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, relative to 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 has a function of forming a dispersion by bonding with an organic pigment and an anchor portion, and the compatible portion extends into the dispersion medium, and is different from the alkali-soluble resin and photopolymerizable monomer used in the preparation of the photosensitive composition described below. In addition to the resin-based dispersant, rosin, surfactant, etc. may be further contained. These components may or may not be treated on the pigment surface (so-called surface treatment). The method for treating the pigment surface may be a known method such as rosin treatment, surfactant treatment, solvent treatment, resin treatment, etc.

[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 them, 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.), Polyflow (manufactured by Kyoeisha Chemical Co., Ltd.), etc. These dispersants may be used alone or in any combination and ratio of two or more kinds.

[0035] The proportion of the resin-based 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 necessary. If necessary, the coloring composition can be prepared by shaking for a required time in the presence of various grinding media such as beads and rods, and 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. In order to obtain a red pixel of a preferred color tone (toning), 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 to form a red pixel portion by photolithography using the coloring composition. 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 a hydroxyl group exhibiting acidity, 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, 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 a total of 3 to 20 parts 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 uniformly.

[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 and 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 a photolithography method, in which the red pixel portion is formed by applying the above-mentioned photosensitive composition containing the coloring composition of the present invention onto a transparent substrate such as glass for a color filter, drying by heating (pre-baking), and then irradiating with ultraviolet light through a photomask to perform pattern exposure to cure the photocurable compound at the portion corresponding to the pixel portion such as red, and then developing the unexposed portion with a developer, removing the non-pixel portion, and fixing the pixel portion to the transparent substrate. With this method, a red pixel portion consisting of a cured colored film of the photosensitive composition is formed on the transparent substrate. Each pixel portion of green (G) and blue (B) can also be similarly produced from a photosensitive composition prepared from an organic pigment of each color in the above manner.

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

[0045] The drying conditions of the coating film of the photosensitive composition applied to the transparent substrate vary depending on the type and mixing ratio of each component, but are usually 50 to 150°C and about 1 to 15 minutes. This heat treatment is generally called pre-baking. In addition, as the light used for photocuring the photosensitive composition, ultraviolet light or visible light in the wavelength range of 200 to 500 nm is preferably used. Various light sources that emit light in this wavelength range can be used. Examples of development methods that can use various light sources that emit light in this wavelength range include a puddle method, a dipping method, and a spray method. After the exposure and development of the photosensitive composition, the transparent substrate on which the pixel parts of the required colors are formed is washed with water and dried. The color filter thus obtained is heat-treated (post-baked) for a predetermined time by a heating device such as a hot plate or oven at 90 to 280°C to remove volatile components in the color coating film and at the same time, the unreacted photocurable compound remaining in the cured color film of the photosensitive composition is thermally cured, 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 a pattern of alternating color filter colored pixel portions selected from one of red (R), green (G), and blue (B) 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 transparent electrodes. EXAMPLES

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

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

[0049] [Table 1]

[0050] [Preparation of colored composition for evaluating color filter characteristics] The pigment composition and CI Pigment Yellow 139 prepared in Table 1 above were mixed in such a way that the blending ratio of the pigment composition:CI Pigment Yellow 139 was 9:1 to 1:9 parts, and 1.82 parts of the mixture, 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 with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.). The obtained dispersion liquid (4.44 parts) and 0.95 parts of Unidic ZL-295 (manufactured by DIC Corporation) were placed in a glass bottle and shaken to obtain colored compositions of Examples 1 to 19 and Comparative Example 1.

[0051] [Preparation of color filters for evaluation] The colored composition obtained above was applied onto 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 substrate. By adjusting the rotation speed of the spin coater, a coating film having a film thickness of about 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 Co., Ltd. In this manner, a number of evaluation color filters having different composition ratios of the pigment composition and CI Pigment Yellow 139 were prepared.

[0052] [Color filter characterization: chromaticity x at specific chromaticity y] FIG. 1 shows plots of chromaticity x and y values ​​measured with a spectrophotometer (U3900 manufactured by Hitachi High-Tech Science Corporation) under Illuminant C for the evaluation color filters prepared above. FIG. 1 shows data for Examples 1 to 19 and Comparative Example 1. Table 2 below shows the calculated value of x where chromaticity y=0.313. By comparing the chromaticity x value at a specific chromaticity y, the spread of the color gamut relative to CI Pigment Red 177 was evaluated by the chromaticity difference Δx. A negative value of Δx (compared to PR177) indicates that the chromaticity spreads toward the yellowish side.

[0053] [Table 2]

[0054] In Examples 1 to 19 shown in Table 1 above, Δx (compared to PR177) was a negative value for all of them, and it can be seen that the color gamut expanded in the yellowish direction. In particular, a remarkable 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 with 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, 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 colored compositions of Examples 2-1 to 2-14 and Comparative Example 2-1.

[0056] (Contrast Evaluation 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, then dried at 90° C. for 3 minutes and allowed to cool. After that, the substrate was heated (post-baked) at 230° C. for 1 hour to prepare a coated 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] [Table 3]

[0058] (Preparation of Coloring Composition for Brightness Evaluation) The pigment composition prepared in Table 1 and CI Pigment Yellow 139 were mixed in the ratio shown in Table 4 below, and 1.82 parts of the mixture, 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 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 colored compositions of Examples 3-1 to 3-9 and Comparative Example 3-1.

[0059] (Brightness Evaluation of Pigment Composition) The colored composition obtained above was applied onto 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 coating substrate. The film thickness after drying was adjusted by adjusting the rotation speed of the spin coater to obtain a coating film with chromaticity (x, y) = (0.679, 0.313). The evaluation chromaticity x, y was the evaluation chromaticity described in

[0150] of Patent No. 7046777. The obtained coating film was measured for spectroscopy 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 the C light source. The larger the Y value, the higher the luminance. The luminance Y after post-baking (PB) is shown in Table 4.

[0060] [Table 4]

[0061] Examples 2-1 to 2-14, which show contrast values ​​in Table 3, i.e., combinations of PR177 and SO56, SR233, SR160, SR130, SY21, SY82, SO54, SY81, or SY79, are yellowish and have high contrast, and are therefore suitable for use in LCDs (liquid crystal displays).Furthermore, Examples 3-1 to 3-9, which show brightness values ​​in Table 4, which show combinations of PR177 and SO56, SR233, SR160, SY21, SO60, SY81, SR195, or SY79, are yellowish and have high brightness, and are therefore suitable for use in OLEDs (organic electroluminescence displays).

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 ratio of the pigment in the pigment composition is 80 to 95% by mass, The pigment composition has a content of the colorant of 5 to 20% by mass.

2. 2. The pigment composition of claim 1, wherein the colorant is selected from the group consisting of Solvent Yellow 79, Solvent Red 233, Pigment Yellow 147, Solvent Orange 60, and Solvent Red 195.

3. In the pigment, the ratio of pigments other than C.I. Pigment Red 177 is 20 mass% or less, The pigment composition according to claim 1 or 2, 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.

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

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

Images