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

Abstract

The present invention addresses the problem of providing: a pigment composition which can particularly enlarge the yellow region in a red pixel section; a coloring composition for a color filter, which contains the pigment composition; and a color filter. Specifically, the pigment composition of the present invention comprises: 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. The pigment composition of the present invention comprises: 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. A coloring composition for a color filter according to the present invention contains the pigment composition, a solvent, and a binder resin. The color filter of the present invention has a pixel portion containing a pigment composition.

Description

Technical Field

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

[0002] A color filter converts the white backlight into red, green, and blue, thereby achieving color display on a display. The color filter comprises a red pixel portion (R), a green pixel portion (G), and a blue pixel portion (B). Each of these pixel portions is a thin film of synthetic resin in which organic pigments are dispersed, disposed on a substrate. The organic pigments used are red, green, and blue.

[0003] Among these pixel portions, as red organic pigments for forming red pixel portions, diketopyrrolopyrrole pigments (CI Pigment Red 254), diaminodianthraquinone pigments (CI Pigment Red 177), condensed azo pigments (CI Pigment Red 242), and azo pigments (CI Pigment Red 269) are generally used. In order to adjust the color as needed, yellow organic pigments such as isoindoline pigments (CI Pigment Yellow 139) and nickel azo pigments (CI Pigment Yellow 150) are used in combination.

[0004] Among these red organic pigments, CI Pigment Red 254, a yellowish diketopyrrolopyrrole-based red pigment, has a high brightness but is considered to have a problem of low contrast.

[0005] Meanwhile, CI Pigment Red 177, a bluish diaminoanthraquinone pigment, is increasingly being used as a complementary color to improve the contrast of CI Pigment Red 254. However, increasing the content of bluish diaminoanthraquinone pigments can deviate from the target color tone, leading to the challenge of achieving both color tone adjustment and high contrast.

[0006] Examples of color filter coloring compositions for use in red pixel areas such as those described above include Patent Documents 1 and 2. Patent Document 1 discloses a color filter coloring composition comprising a colorant, a metal complex, a binder resin, and an organic solvent, wherein the colorant comprises a specific naphthol azo pigment and a metal complex having a specific central metal. Patent Document 2 discloses a red color filter pigment composition characterized by containing, by mass, 20 parts of a phthalimide-alkylated quinacridone, exceeding 10 parts, per 100 parts of a diketopyrrolopyrrole pigment, and having an average primary particle size of 10 to 30 nm.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-114940

[0010] Patent Document 2: Japanese Patent No. 6089710 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] In the above-mentioned patent document 1, although metal complex dyes are used to improve contrast, the effect of color gamut expansion is not seen. In the above-mentioned patent document 2, although Pigment Red 254 is used as a yellowish red pigment, a micronization process is required for high contrast. That is, in order to expand the color gamut of the red colorant in the yellowish direction, it is necessary to change the skeleton of the pigment itself, such as replacing CI Pigment Red 177 with Pigment Red 254 or Pigment Red 242. In the prior art other than Patent Document 1, although high-contrast CI Pigment Red 177 is used as a red colorant for color filters, as mentioned above, it is not yellowish enough, so there is a problem of not being able to display the target color gamut.

[0013] Therefore, an object of the present invention is to provide a pigment composition that can expand the yellowish color range particularly when CI Pigment Red 177, which is excellent in contrast and heat resistance, is included in a red pixel portion, a coloring composition for color filters containing the same, and a color filter.

[0014] Means for solving problems

[0015] The inventors of the present invention have discovered that by combining CI Pigment Red 177 with a specific colorant, the yellowish gamut can be particularly expanded in the red pixel area. It should be noted that the yellowish gamut in the present invention refers to the color gamut in which the x value of y = 0.313 is less than 0.68586 in the chromaticity coordinates represented by the chromaticity x and y measured by light source C for a color filter produced by mixing a pigment composition containing Pigment Red 177 and a specific colorant with Pigment Yellow 139 in a specific ratio. In the present invention, by adding a specific colorant, the absorption on the short wavelength side that is insufficient in Pigment Red 177 can be supplemented, thereby expanding the yellowish gamut.

[0016] That is, the present invention is as follows.

[0017] [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.

[0018] [2] A coloring composition for a color filter, comprising the pigment composition described in [1], a solvent, and a binder resin.

[0019] [3] A color filter having a pixel portion containing the pigment composition described in [1].

[0020] Effects of the Invention

[0021] The pigment composition of the present invention can maintain contrast while expanding the yellowish tint region, particularly in red pixels, thereby broadening the range that can be expressed in chromaticity x and y. Therefore, it is suitable as a coloring composition for color filters used to produce red pixels in color filters. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a graph in which the chromaticity x and y values ​​measured using light source C in the characteristic evaluation of the color filter of the example are plotted. DETAILED DESCRIPTION

[0023] [Pigment composition]

[0024] The pigment composition of the present invention includes 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), an anthraquinone pigment. The pigment composition of the present invention is not particularly limited as long as it includes the above-mentioned colorants and PR177, and may also include dyes or pigments other than these. The above-mentioned colorants may be used alone or in combination of two or more.

[0025] The PR177 used in the present invention is preferably micronized before use, but the micronization method is not particularly limited. For example, any of wet grinding, dry grinding, and dissolution separation methods can be used. From the perspective of good dispersion in the colorant carrier, the primary particle size of the micronized pigment is preferably 20 nm or more. In addition, from the perspective of being able to form a high-contrast color filter, it is preferably 100 nm or less. The particularly preferred range is 25 to 85 nm. When micronizing PR177, a resin can be added as needed. Examples of the resin include natural resins, modified natural resins, synthetic resins, and synthetic resins modified from natural resins.

[0026] Among the 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, and solvent yellow 79 is particularly preferred because they have a greater effect of expanding the yellowish color range.

[0027] 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 preferably a colorant that dissolves in the colorant carrier when the color filter coating is heated at 230°C for one hour. Using such a highly soluble dye can produce a color filter coloring composition with excellent brightness and contrast.

[0028] When a color range close to the DCI standard is preferred, the ratio of the colorant (if two or more are included, the total ratio is preferably 0.5 to 8% by mass, or 2 to 8 parts by mass). When a color range with a yellowish hue (e.g., the sRGB standard) is preferred, the ratio of the dye is preferably 10 to 90% by mass, or 15 to 25%, for example.

[0029] The pigment composition of the present invention may also contain red organic pigments other than PR177, blue organic pigments, and yellow organic pigments. 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, 2 32, 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, 276.

[0030] Examples of the blue organic pigment include 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, and 80.

[0031] 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, 229.

[0032] Red organic pigments, blue organic pigments, and yellow organic pigments other than PR177 can be used in a range not impairing the effects of the present invention, but their proportion in the pigments in the pigment composition of the present invention is, for example, 20% by mass or less, preferably 10% by mass or less.

[0033] Dyes other than the dyes listed above as colorants 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, 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.

[0034] Dyes other than the dyes listed above as colorants may be used in a range not impairing the effects of the present invention, but their proportion in the dyes in the pigment composition of the present invention is, for example, 20% by mass or less, preferably 10% by mass or less.

[0035] In the pigment composition of the present invention, in addition to the pigment / dyes, various derivatives may be used in combination as needed to improve dispersibility. Examples of substituents on the pigment / dye backbone in such derivatives include sulfonic acid groups, sulfonamide groups and their quaternary salts, phthalimidomethyl groups, dialkylaminoalkyl groups, hydroxyl groups, carboxyl groups, and amide groups, which are directly bonded to the pigment backbone or bonded to the pigment backbone via alkyl groups, aryl groups, heterocyclic groups, and the like.

[0036] The pigment composition of the present invention can be prepared by mixing and stirring (dry blending) powders of a pigment including PR177 and a colorant such as Solvent Yellow 79, or by mixing the pigment and the colorant in separate dispersions.

[0037] [Coloring composition for color filter]

[0038] The coloring composition for color filters 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 or the like as needed.

[0039] As the above-mentioned solvent, an organic solvent is generally 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, Varsol #2, Apco #18 solvent, diisobutylene, amyl acetate, butyl acetate, Apco thinner, butyl ether, diisobutyl ketone, methylcyclohexene, methyl nonyl ketone, dipropyl ether, dodecane, SoCalSolvent No. 1 and No. 2, amyl formate, dihexyl ether, diisopropyl ketone, SOLVESSO #150, (n-, iso-, tert-)butyl acetate, hexene, Shell TS28 solvent, chlorobutane, ethyl amyl ketone, ethyl benzoate, chloropentane, ethylene glycol diethyl ether, ethyl orthoformate, and the like. orthoformate), methoxymethyl amyl ketone, 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, dicyclohexyl, diethylene glycol monoethyl ether acetate, dipentene, methoxymethyl amyl alcohol, methyl amyl ketone, methyl isopropyl ketone, propyl propionate, propylene glycol tert-butyl ether, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, carbitol, cyclohexanone, ethyl acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl 3-methoxypropionic 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 tert-butyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol, tripropylene glycol methyl ether, ethyl lactate.

[0040] 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.

[0041] 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, in the entire wavelength range of 400 to 700 nm in the visible light region.

[0042] Examples of the thermoplastic resin include acrylic resins, butyral resins, styrene-maleic acid copolymers, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyvinyl acetate, polyurethane resins, polyester resins, vinyl resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclized rubber resins, cellulose resins, polyethylene (HDPE, LDPE), polybutadiene, and polyimide resins. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenolic resins.

[0043] The ratio of the binder resin relative to 100 parts by mass of the pigment composition is, for example, 30 to 500 parts by mass, or preferably 40 to 400 parts by mass.

[0044] When dispersing the above-mentioned pigment composition in a solvent, a resin-based dispersant may also be used to improve dispersibility and dispersion stability. This resin-based dispersant is a substance that has the function of combining with the organic pigment and anchoring site, extending the compatibility portion in the dispersion medium to form a dispersion. It is a different type from the alkali-soluble resin and photopolymerizable monomer used to prepare the photosensitive composition described below. In addition to the resin-based dispersant, rosin, surfactant, etc. may also be included. These components may be treated on the pigment surface (so-called surface treatment) or not. As methods for treating the pigment surface, known methods such as rosin treatment, surfactant treatment, solvent treatment, and resin treatment may be used.

[0045] 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.

[0046] Specific examples of various resin-based dispersants include those sold under the trade names of AJISPER (manufactured by Ajinomoto Fine-Techno Co., Ltd.), EFKA (manufactured by BASF), DISPERBYK (manufactured by BYK Chemie Co., Ltd.), BYKLPN (manufactured by BYK Chemie Co., Ltd.), 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 in combination of two or more in any desired combination and ratio.

[0047] The ratio of the resin-based dispersant is, for example, 60 to 90 parts by mass, or preferably 80 to 90 parts by mass per 100 parts by mass of the pigment composition.

[0048] The above-mentioned 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, it can also be prepared by vibrating for a necessary time in the presence of various pulverizing media such as beads and rods, and dispersing the medium by filtration. The coloring composition of the present invention is used for the red pixel portion of the color filter. In order to form a red pixel (toning) of a preferred hue, a coloring composition containing a yellow pigment such as Pigment Yellow 139 is preferably mixed with the coloring composition of the present invention.

[0049] In order to form a red pixel portion using the coloring composition by photolithography or the like, a photosensitive composition is usually prepared. The photosensitive composition includes, for example, the coloring composition, an alkali-soluble resin, a photopolymerizable monomer, and a photopolymerization initiator.

[0050] Examples of the alkali-soluble resin include resins containing a carboxyl group or an acidic hydroxyl group, such as novolac-type phenolic resins, alkyl (meth)acrylate (meth)acrylic acid copolymers, styrene (meth)acrylic acid copolymers, and styrene-maleic acid copolymers.

[0051] 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)acryloyloxyethoxy]bisphenol A, and 3-methylpentanediol di(meth)acrylate; polyfunctional monomers having a relatively small molecular weight 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 various polyfunctional monomers having a relatively large molecular weight such as polyester acrylate, polyurethane acrylate, and polyether acrylate.

[0052] Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketal, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis(4'-azidobenzylidene)-2-propane, 1,3-bis(4-azidobenzylidene)-2-propane-2'-sulfonic acid, 4,4'-diazidebenzylene-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-acetoxime).

[0053] The photosensitive composition is prepared by adding 3 to 20 parts in total of an alkali-soluble resin and a photopolymerizable monomer to 1 part of the pigment composition of the present invention, adding 0.05 to 3 parts of a photopolymerization initiator to 1 part of the photopolymerizable monomer, and optionally further adding a solvent for preparing the coloring composition, and stirring and dispersing the mixture uniformly to obtain a photosensitive composition for forming a pixel portion.

[0054] [Color Filter]

[0055] 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 conventional method using a photosensitive composition containing the coloring composition of the present invention.

[0056] The representative manufacturing method of the color filter is photolithography, which is the following method, that is, for the red pixel portion, the above-mentioned photosensitive composition comprising the coloring composition of the present invention is applied on a transparent substrate such as glass for the color filter, and after heating and drying (pre-baking), ultraviolet rays are irradiated through a mask, thereby performing pattern exposure, and after the photocurable compound corresponding to the pixel portion of the red pixel portion is cured, the unexposed portion is developed with a developer, the non-pixel portion is removed, and the pixel portion is fixedly attached to the transparent substrate. By this method, the red pixel portion formed by the cured coloring film of the photosensitive composition can be formed on a transparent substrate. Each pixel portion of green (G) and blue (B) can also be made in the same manner as described above from a photosensitive composition prepared from an organic pigment of each color.

[0057] As a method for coating a photosensitive composition on a transparent substrate, there are spin coating, roll coating, slit coating, ink jet method, etc. in addition to the photolithography method.

[0058] The drying conditions of the coating film of the photosensitive composition applied to the transparent substrate vary depending on the type and proportion of each component, but are generally 50 to 150°C for about 1 to 15 minutes. This heating treatment is generally called pre-baking. In addition, as the light used for photocuring of the photosensitive composition, ultraviolet rays or visible light in the wavelength range of 200 to 500 nm are preferably used. Various light sources that emit light in this wavelength range can be used. As development methods that can use various light sources that emit light in this wavelength range, for example, a liquid method, an immersion method, a spraying method, etc. can be mentioned. After exposure and development of the photosensitive composition, the transparent substrate with the pixel portion of the desired color formed is washed with water and then dried. The color filter obtained in this manner is passed through a heating device such as a hot plate or an oven and subjected to a predetermined time heating treatment (post-baking) at 90 to 280°C to remove the volatile components in the colored coating film. At the same time, the unreacted photocurable compound remaining in the cured colored film of the photosensitive composition is thermally cured to complete the color filter.

[0059] The color filter can be obtained as follows: by forming a coating film of a 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 intervals, and at the same time, alternately arranging color filter colored pixel portions of any one color selected from red (R), green (G) and blue (B) in a pattern in each fine interval divided into a grid shape by a black matrix on the transparent electrode, or by forming a color filter colored pixel portion on a substrate and then arranging a transparent electrode.

[0060] Example

[0061] Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples. In the present Examples, "parts" means "parts by mass."

[0062] [Preparation of Pigment Composition]

[0063] CI Pigment Red 177 and the colorants listed in Table 1 below were mixed and stirred at the ratios listed in Table 1 to obtain pigment compositions 1 to 20. In addition, pigment composition 20 used only CI Pigment Red 177 and no colorant.

[0064] [Table 1]

[0065] Pigment type Colorants Pigment ratio Colorant ratio Pigment composition 1 PR177 SY79 95 5 Pigment composition 2 PR177 SO56 90 10 Pigment composition 3 PR177 SR233 90 10 Pigment composition 4 PR177 SR160 90 10 Pigment composition 5 PR177 SO56 95 5 Pigment composition 6 PR177 SR130 90 10 Pigment composition 7 PR177 SY79 80 20 Pigment composition 8 PR177 SR160 95 5 Pigment composition 9 PR177 SR233 95 5 Pigment composition 10 PR177 SY21 95 5 Pigment composition 11 PR177 PY147 95 5 Pigment composition 12 PR177 SO60 95 5 Pigment composition 13 PR177 SO54 90 10 Pigment composition 14 PR177 SY82 95 5 Pigment composition 15 PR177 SR130 95 5 Pigment composition 16 PR177 SO54 95 5 Pigment composition 17 PR177 SY81 95 5 Pigment composition 18 PR177 SY88 95 5 Pigment composition 19 PR177 SR195 95 5 Pigment composition 20 PR177 none 100 0

[0066] [Preparation of Coloring Composition for Color Filter Property Evaluation]

[0067] 1.82 parts of a mixture prepared by mixing the pigment composition prepared in Table 1 above with CI Pigment Yellow 139 at a pigment composition:CI Pigment Yellow 139 ratio of 9:1 to 1:9, 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. Zirconia beads with a diameter of 0.3 to 0.4 mm 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 resulting 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 1 to 19 and Comparative Example 1.

[0068] [Production of Evaluation Color Filters]

[0069] The resulting coloring composition was applied to a soda glass substrate using a spin coater, dried at 90°C for 3 minutes, left to cool, and then heated (post-baked) at 230°C for 1 hour to produce a coated substrate. The spin coater speed was adjusted to obtain a coating film with a thickness of approximately 3.5 μm after drying. The film thickness was measured using a white interference microscope (VS1330) manufactured by Hitachi High-Tech Scientific Co., Ltd. In this manner, multiple evaluation color filters were produced with different composition ratios of the pigment composition to CI Pigment Yellow 139.

[0070] [Characteristics Evaluation of Color Filter: Chromaticity x of Specific Chromaticity y]

[0071] Figure 1 This is a graph obtained by plotting the chromaticity x and y values ​​obtained by measuring the color of the evaluation filter produced above using a spectrophotometer (U3900 manufactured by Hitachi High-Tech Scientific Co., Ltd.) using a C light source. Figure 1The data for Examples 1 to 19 and Comparative Example 1 are shown in Table 2. Table 2 below shows the calculated value of x for a chromaticity y = 0.313. By comparing the chromaticity x value for a specific chromaticity y, the chromaticity difference Δx is used to evaluate the expansion of the color gamut relative to CI Pigment Red 177. A negative value for Δx (PR177 ratio) indicates an expansion of the chromaticity toward yellow.

[0072] [Table 2]

[0073] Pigment composition The value of x when y=0.313 Δx (PR177 ratio) Example 1-1 Pigment composition 1 0.68428 -0.00158 Example 1-2 Pigment composition 2 0.68460 -0.00126 Examples 1-3 Pigment composition 3 0.68470 -0.00116 Examples 1-4 Pigment composition 4 0.68500 -0.00086 Examples 1-5 Pigment composition 5 0.68507 -0.00079 Examples 1-6 Pigment composition 6 0.68520 -0.00066 Examples 1-7 Pigment composition 7 0.68520 -0.00066 Examples 1-8 Pigment composition 8 0.68524 -0.00062 Examples 1-9 Pigment composition 9 0.68543 -0.00043 Examples 1-10 Pigment composition 10 0.68548 -0.00038 Examples 1-11 Pigment composition 11 0.68555 -0.00031 Examples 1-12 Pigment composition 12 0.68557 -0.00029 Examples 1-13 Pigment composition 13 0.68563 -0.00023 Examples 1-14 Pigment composition 14 0.68568 -0.00018 Examples 1-15 Pigment composition 15 0.68570 -0.00016 Examples 1-16 Pigment composition 16 0.68575 -0.00011 Examples 1-17 Pigment composition 17 0.68578 -0.00008 Examples 1-18 Pigment composition 18 0.68579 -0.00007 Examples 1-19 Pigment composition 19 0.68583 -0.00003 Comparative Example 1-1 Pigment composition 20 0.68586 0

[0074] In Examples 1 to 19 shown in Table 1, Δx (PR177 ratio) is negative, indicating that the color gamut has expanded toward yellow. In particular, the combination of PR177 and SY79 in Example 1 shows a significant color gamut expansion effect.

[0075] (Preparation of Coloring Composition for Contrast Evaluation)

[0076] 1.82 parts of the pigment composition prepared using the pigment ratios listed 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, 0.3-0.4 mm φ zirconium oxide beads were added, and the mixture was dispersed for 3 hours using a paint mixer (manufactured by Toyo Seiki Co., Ltd.). 4.44 parts of the resulting 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 2-1 to 2-14 and Comparative Example 2-1.

[0077] (Evaluation of contrast of pigment composition)

[0078] The above-mentioned coloring composition was applied to a soda glass substrate using a spin coater to a dry film thickness of 3.5 μm. The composition was then dried at 90°C for 3 minutes and allowed to cool. The composition was then heated (post-baked) at 230°C for 1 hour to produce a coated substrate. The contrast ratio of the colored film in the evaluation color filter produced above was measured using a contrast meter CT-1 manufactured by Tsubosaka Electric Co., Ltd. The contrast ratio after post-baking (PB) is shown in Table 3 below.

[0079] [Table 3]

[0080] Pigment composition Contrast after PB Example 2-1 Pigment composition 1 103％ Example 2-2 Pigment composition 2 105％ Example 2-3 Pigment composition 3 116％ Examples 2-4 Pigment composition 4 117％ Examples 2-5 Pigment composition 5 103％ Examples 2-6 Pigment composition 6 109％ Examples 2-7 Pigment composition 7 110％ Examples 2-8 Pigment composition 8 108％ Examples 2-9 Pigment composition 9 106％ Example 2-10 Pigment composition 10 106％ Example 2-11 Pigment composition 14 113％ Example 2-12 Pigment composition 15 104％ Example 2-13 Pigment composition 16 102％ Examples 2-14 Pigment composition 17 112％ Comparative Example 2-1 Pigment composition 20 100％

[0081] (Preparation of Coloring Composition for Brightness Evaluation)

[0082] 1.82 parts of a mixture prepared by mixing the pigment composition prepared in Table 1 above with CI Pigment Yellow 139 at the ratios 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. Zirconia beads having a diameter of 0.3 to 0.4 mm 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 resulting 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.

[0083] (Brightness Evaluation of Pigment Composition)

[0084] The coloring composition obtained above was applied to a soda glass substrate using a spin coater, dried at 90°C for 3 minutes, left to cool, and then heated (post-baked) at 230°C for 1 hour to obtain a coated substrate. The film thickness after drying was adjusted by adjusting the number of revolutions of the spin coater to obtain a coating film having a chromaticity (x, y) = (0.679, 0.313). It should be noted that the chromaticity x, y was evaluated using the evaluation chromaticity described in

[0150] of Japanese Patent No. 7046777. The obtained coating film was spectrally measured using a colorimeter (U-3900 manufactured by Hitachi High-Tech Science Co., Ltd.) using the colorimetric function of the C illuminant and measuring the luminance Y using the tristimulus value Y in the CIE XYZ color system. The larger the Y value, the higher the luminance. The luminance Y after post-baking (PB) is shown in Table 4.

[0085] [Table 4]

[0086]

[0087] In Examples 2-1 to 2-14, whose contrast values ​​are shown in Table 3 above, combinations of PR177 with SO56, SR233, SR160, SR130, SY21, SY82, SO54, SY81, or SY79 exhibit yellowish tint and high contrast, suggesting suitability for applications such as LCDs (liquid crystal displays). Furthermore, in Examples 3-1 to 3-9, whose brightness values ​​are shown in Table 4 above, combinations of PR177 with SO56, SR233, SR160, SY21, SO60, SY81, SR195, or SY79 exhibit yellowish tint and high brightness, suggesting suitability for applications such as OLEDs (organic electroluminescent displays).

Claims

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 claim 1 , a solvent, and a binder resin. 3 . A color filter comprising a pixel portion containing the pigment composition according to claim 1 .

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