JP7552207B2 - Color filter, display device, electronic paper, white display method, and composition for forming color-adjusting member - Google Patents

Description

The present invention relates to a color filter, a display device, electronic paper, a white display method, and a composition for forming a color adjusting member.

Liquid crystal display devices are used in a variety of applications, including televisions, laptops, personal digital assistants, smartphones, and digital cameras, taking advantage of their characteristics of being lightweight, thin, and low power consumption. Depending on the application, LCD devices are required to display the optimal colors out of three to six primary colors, and color filter substrates that provide a variety of color performance are used.

In recent years, electronic paper has been increasingly used as a display device other than liquid crystal displays. Electronic paper has features such as low power consumption and being easy on the eyes, and efforts are being made to make it colorized. To achieve colorization, color ink methods and color filter methods are being considered, but the color filter method is attracting attention due to its display switching speed.

Electronic paper does not adjust brightness using backlight light like general liquid crystal display devices, but instead uses external light as a display principle, which means that the display is dark. To improve the vividness of the display, electronic paper that does not have a black matrix between pixels and electronic paper that has a white light-shielding material between pixels have been proposed (for example, Patent Document 1 and Patent Document 2). However, these technologies were unable to achieve both vivid display of each color and low saturation and bright white display.

JP 2003-107234 A JP 2013-88750 A

When displaying colors using electronic paper with color filters, the amount of external light required for display is small, and it is necessary to design each pixel color to display the desired color. As a result, when displaying white, it is difficult to display the desired white, and improvements were necessary.

In view of this situation, the present invention aims to provide a color filter, and in particular a reflective display device, that is capable of displaying each color brightly and vividly, even in a reflective display device, and that is capable of displaying a bright white color with low saturation when displaying white.

The present invention is a color filter having at least one of red, green, and blue subpixels on a substrate, characterized in that a color-adjusting member having a Y value of 70 or more and 98 or less in the CIE 1931 color system is disposed between the subpixels.

The present invention also relates to a display device having the color filter of the present invention.

The present invention also relates to electronic paper having the color filter of the present invention.

The present invention also relates to a composition for forming a color-adjusting member, which is characterized in that when formed into a film having a thickness of 2 μm, the Y value in the CIE 1931 color system is 70 or more and 98 or less.

The color filter of the present invention makes it possible to display each color brightly and vividly, even in a reflective display device, and to display a bright white color with low saturation.

FIG. 1 is a diagram showing an example of the arrangement of red, green and blue sub-pixels and color adjusting members. FIG. 2 is a diagram showing an example of the arrangement of red, green, blue and fourth sub-pixels, as well as color adjusting members. FIG. 3 is a diagram showing an example of the arrangement of red, green, blue and yellow sub-pixels and color adjusting members. FIG. 4 is a diagram showing another example of the arrangement of the red, green, blue and fourth sub-pixels, and the color adjusting members. FIG. 5 is a diagram showing another example of the arrangement of red, green, blue and yellow sub-pixels and color adjusting members.

The present invention will be described in detail below. In the present invention, "or more" means that the value is the same as or larger than the indicated value. Also, "or less" means that the value is the same as or smaller than the indicated value.

The color filter of the present invention has a substrate. Examples of the substrate include inorganic glass plates such as soda glass, alkali-free glass, borosilicate glass, quartz glass, aluminoborosilicate glass, aluminosilicate glass, alkali aluminosilicate glass, and soda lime glass with a silica-coated surface, as well as organic plastic films and sheets. Two or more of these may be laminated. Note that when the display device equipped with the color filter of the present invention is a reflective display device or a display device having a light-emitting element such as a silicon OLED, the substrate may be opaque.

The organic plastic film or sheet may be a free-standing film, or may be a film formed by coating on a substrate such as a glass substrate. In the case of such a coated film, the adhesion between the substrate and the film can be appropriately adjusted by a laser or the like to peel it off. Examples of organic plastic materials include polyesters such as polypropylene, polyethylene, polystyrene, and polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyimide, polyamide, polyamideimide, polyethersulfone, fluorine-containing polymers such as polytetrafluoroethylene (PTFE), polyetheretherketone, polyphenylene ether, polyarylate, and polysulfone.

When the substrate is an organic plastic film, from the viewpoint of substrate strength, the substrate is preferably a film having a thickness of 5 μm or more, and more preferably 10 μm or more. On the other hand, from the viewpoint of flexibility, the substrate is preferably a film having a thickness of 100 μm or less.

The color filter of the present invention has at least one of red (R), green (G) and blue (B) subpixels on the substrate. In the present invention, a subpixel refers to each single-color point that constitutes one pixel on a display. By having one of red, green and blue subpixels, it is possible to display the color corresponding to each pixel or an additive mixture of these colors. In addition, having red, green and blue subpixels on the substrate is preferable because it makes it possible to express the colors inside the RGB color triangle, whose vertices are the three primary colors of RGB.

It is also preferable to have a yellow (Y) subpixel in addition to red, green, and blue. This allows the colors inside the quadrilateral consisting of the four vertices of RYGB to be expressed, making it possible to more vividly express colors such as the golden color of brass instruments.

Examples of materials constituting the coloring composition that forms the subpixels include coloring compositions that contain colorants, binder resins such as acrylic resins and polyimide resins, and radically polymerizable compounds.

The coloring material contained in the coloring composition may be an organic pigment, an inorganic pigment, a dye, etc., and may contain two or more of these. Among these, organic pigments and dyes are preferred from the viewpoint of further improving the transmittance.

Examples of red colorants include C.I. Pigment Red (hereinafter referred to as "PR") 9, PR48, PR97, PR122, PR123, PR144, PR149, PR166, PR168, PR177, PR179, PR180, PR192, PR209, PR215, PR216, PR217, PR220, PR223, PR224, PR226, PR227, PR228, PR240, PR254, and diketopyrrolopyrrole colorants having bromine groups. From the viewpoint of the luminance characteristics of the subpixel, PR254, PR177, and diketopyrrolopyrrole colorants having a bromine group are preferred, and from the viewpoint of the brightness and vividness of the red display of the electronic paper, it is preferred to use a diketopyrrolopyrrole colorant having a bromine group. Also, from the viewpoint of the brightness, vividness, and display color of the red display of the electronic paper, it is preferred that the proportion of diketopyrrolopyrrole colorant having a bromine group among the colorants contained in the red subpixel is 70 mass% or more.

Examples of green colorants include C.I. Pigment Green (hereinafter referred to as "PG") PG1, PG2, PG4, PG7, PG8, PG10, PG13, PG14, PG15, PG17, PG18, PG19, PG26, PG36, PG38, PG39, PG45, PG48, PG50, PG51, PG54, PG55, PG58, and PG59. From the viewpoint of the luminance characteristics of the subpixel, PG58 and PG59 are preferred.

Examples of yellow colorants include C.I. Pigment Yellow (hereinafter referred to as "PY") 12, PY13, PY17, PY20, PY24, PY83, PY86, PY93, PY95, PY109, PY110, PY117, PY125, PY129, PY137, PY138, PY139, PY147, PY148, PY150, PY153, PY154, PY166, PY168, and PY185. From the viewpoints of color purity, transmittance, and contrast ratio, PY129, PY138, PY139, and PY150 are preferred, PY138 and PY150 are more preferred, and PY150 is even more preferred.

Examples of orange colorants include C.I. Pigment Orange (hereinafter referred to as "PO") 13, PO31, PO36, PO38, PO40, PO42, PO43, PO51, PO55, PO59, PO61, PO64, PO65, and PO71.

Examples of blue colorants include C.I. Pigment Blue (hereinafter referred to as "PB") 15, PB15:3, PB15:4, PB15:6, PB21, PB22, PB60, and PB64.

Examples of purple colorants include C.I. Pigment Violet (hereinafter referred to as "PV") 19, PV23, PV29, PV30, PV32, PV37, PV40, and PV50 (all numbers are color index numbers).

The coloring material may be a dye, and examples of the dye include oil-soluble dyes, acid dyes, direct dyes, basic dyes, and acid mordant dyes. The dyes may also be made into lakes, or may be made into salt-forming compounds of the dye and a nitrogen-containing compound.

Examples of red, green, blue, purple or yellow dyes include direct dyes, acid dyes, and basic dyes. Specific examples of these dyes include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, xanthene dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. The dyes may be dissolved in the coloring composition or dispersed as particles.

The coloring composition may contain a radically polymerizable compound. Examples of radically polymerizable compounds contained in the coloring composition include ethylene oxide modified products or propylene oxide modified products such as dipentaerythritol penta(meth)acrylate, tetratrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester, dipentaerythritol hexa(meth)acrylate, styrene derivatives, polyfunctional maleimide compounds, poly(meth)acrylate carbamates, adipic acid 1,6-hexanediol (meth)acrylic acid esters, fluoroanhydrides, and the like. Examples of suitable acrylates include propylene oxide (meth)acrylic acid ester, diethylene glycol trimellitic acid (meth)acrylic acid ester, rosin-modified epoxy di(meth)acrylate, alkyd-modified (meth)acrylate and other oligomers, tripropylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate and other bifunctional (meth)acrylates, trimethylolpropane tri(meth)acrylate, triacrylformal, bisphenoxyethanol fluorene diacrylate, dicyclopentanedienyl diacrylate, and alkyl-modified, alkyl ether-modified and alkyl ester-modified products thereof. Two or more of these may be used.

From the viewpoint of patterning properties, the content of the radical polymerizable compound is preferably 40% by mass or more in the solid content of the coloring composition. On the other hand, from the viewpoint of suppressing unevenness in the film thickness during film formation and suppressing deformation of the pattern due to flow during baking, the content of the radical polymerizable compound is preferably 90% by mass or less in the solid content, more preferably 70% by mass or less, and even more preferably 60% by mass or less. Also, from the viewpoint of patterning properties, the content of the radical polymerizable compound having three or more (meth)acryloyl groups and carboxyl groups is preferably 50% by mass or more in the radical polymerizable compound, and even more preferably 60% by mass or more.

The coloring composition may further contain binder resins, dispersants, photopolymerization initiators, chain transfer agents, sensitizers, organic solvents, polymerization inhibitors, adhesion improvers, surfactants, organic acids, organic amino compounds, curing agents, etc.

Examples of binder resins contained in the coloring composition include acrylic resins, epoxy resins, polyimide resins, urethane resins, urea resins, polyvinyl alcohol resins, melamine resins, polyamide resins, polyamideimide resins, polyester resins, polyolefin resins, and the like. Two or more of these may be contained. From the viewpoint of stability, acrylic resins are preferably used.

As the acrylic resin, a copolymer of an unsaturated carboxylic acid and an ethylenically unsaturated compound is preferred.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid, and acid anhydrides thereof. Two or more of these may be used.

Examples of ethylenically unsaturated compounds include unsaturated carboxylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and benzyl (meth)acrylate; aromatic vinyl compounds such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, and α-methylstyrene; and aminoethyl Examples of the monomer include unsaturated carboxylic acid amino alkyl esters such as acrylate, unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate and glycidyl methacrylate, carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate, cyanide vinyl compounds such as acrylonitrile, methacrylonitrile and α-chloroacrylonitrile, aliphatic conjugated dienes such as 1,3-butadiene and isoprene, and macromonomers such as polystyrene having a (meth)acryloyl group at the end, polymethyl acrylate, polymethyl methacrylate, polybutyl acrylate, polybutyl methacrylate, and polysilicone. Two or more of these may be used.

It is preferable that the acrylic resin has an ethylenically unsaturated group in the side chain, which can improve sensitivity. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acrylic group, and a methacrylic group. Examples of the acrylic resin having an ethylenically unsaturated group in the side chain include "Cyclomer" (registered trademark) P (Daicel Chemical Industries, Ltd.) and an alkali-soluble cardo resin.

From the viewpoint of the strength of the cured film, the weight average molecular weight of the binder resin is preferably 3,000 or more, and more preferably 9,000 or more. On the other hand, from the viewpoint of the stability of the coloring composition, the weight average molecular weight of the binder resin is preferably 200,000 or less, and more preferably 100,000 or less. Here, the weight average molecular weight of the binder resin refers to a standard polystyrene equivalent value measured by gel permeation chromatography.

From the viewpoint of suppressing unevenness in the film thickness during film formation, the content of the binder resin is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on the solid content of the coloring composition. On the other hand, from the viewpoint of patterning properties, the content of the binder resin is preferably 60% by mass or less, more preferably 50% by mass or less, based on the solid content of the coloring composition.

The color materials contained in the color filters of the present invention can be identified by laser Raman spectroscopy (Ar+ laser (457.9 nm)) or mass analysis using a MALDI mass spectrometer or a time-of-flight secondary ion mass spectrometer.

Examples of dispersants contained in the coloring composition include polyester, polyalkylamine, polyallylamine, polyimine, polyamide, polyurethane, polyacrylate, polyimide, polyamideimide, and copolymers thereof. Two or more of these may be contained. Among these polymer dispersants, those having an amine value of 5 mg KOH/g or more and 200 mg KOH/g or less and an acid value of 1 mg KOH/g or more and 100 mg KOH/g or less in terms of solid content are preferred. Among them, polymer dispersants having basic groups are preferred, and can improve the storage stability of the pigment dispersion and the coloring composition. Examples of commercially available polymer dispersants having basic groups include "Solsperse" (registered trademark) (manufactured by Avecia), "EFKA" (registered trademark) (manufactured by EFKA), "Ajisper" (registered trademark) (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and "BYK" (registered trademark) (manufactured by BYK-Chemie). Two or more of these may be contained. Among these, "Solsperse" (registered trademark) 24000 (manufactured by Avecia), "EFKA" (registered trademark) 4300, 4330 (manufactured by EFKA), 4340 (manufactured by EFKA), "Ajisper" (registered trademark) PB821, PB822 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and "BYK" (registered trademark) 161-163, 2000, 2001, 6919, 21116 (manufactured by BYK-Chemie) are preferred.

Examples of photopolymerization initiators contained in the coloring composition include oxime ester compounds, benzophenone compounds, acetophenone compounds, oxanthone compounds, anthraquinone compounds, imidazole compounds, benzothiazole compounds, benzoxazole compounds, carbazole compounds, triazine compounds, phosphorus compounds, and titanocene compounds.

More specifically, examples of oxime ester compounds include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), ethano Examples of the benzophenone compounds include benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone. Examples of the benzophenone compounds include benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone. Examples of acetophenone compounds include 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutylphenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propane, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and "IRGACURE" (registered trademark) 369, 379, and 907 (manufactured by BASF Ltd.). Examples of anthraquinone compounds include t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, and 2-phenylanthraquinone. Examples of imidazole compounds include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer. Examples of benzothiazole compounds include 2-mercaptobenzothiazole. Examples of benzoxazole compounds include 2-mercaptobenzoxazole. Examples of triazine compounds include 4-(p-methoxyphenyl)-2,6-di-(trichloromethyl)-s-triazine. Two or more of these may be included.

From the viewpoints of sensitivity, patterning ability, and processability, the content of the photopolymerization initiator is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, of the solid content of the coloring composition excluding the coloring material. On the other hand, from the viewpoints of sensitivity, patterning ability, processability, and heat resistance, the content of the photopolymerization initiator is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, of the solid content of the coloring composition excluding the coloring material.

Examples of chain transfer agents contained in the coloring composition include thioglycolic acid, thiomalic acid, thiosalicylic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N-(2-mercaptopropionyl)glycine, 2-mercaptonicotinic acid, 3-[N-(2-mercaptoethyl)carbamoyl]propionic acid, 3-[N-(2-mercaptoethyl)amino]propionic acid, N-(3-mercaptopropionyl)alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, dodecyl(4-methylthio)phenyl ether, 2-mercaptoethanol, 3-mercapto 1,2-propanediol, 1-mercapto-2-propanol, 3-mercapto-2-butanol, mercaptophenol, 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol, 2-mercaptobenzothiazole, mercaptoacetic acid, trimethylolpropane tris(3-mercaptopropionate), 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione), pentaerythritol tetrakis(3-mercaptopropionate), 1,4-bis(3-mercaptobutyryloxy)butane, Karenz (registered trademark) MT Examples of such mercapto compounds include PE-1 (manufactured by Showa Denko K.K.), Karenz (registered trademark) MT NR-1 (manufactured by Showa Denko K.K.), Karenz (registered trademark) MT BD-1 (manufactured by Showa Denko K.K.), and the like; disulfide compounds obtained by oxidizing such mercapto compounds; and iodized alkyl compounds such as iodoacetic acid, iodopropionic acid, 2-iodoethanol, 2-iodoethanesulfonic acid, and 3-iodopropanesulfonic acid. Two or more of these may be contained.

Examples of sensitizers contained in the coloring composition include thioxanthone-based sensitizers and aromatic or aliphatic tertiary amines. Examples of thioxanthone-based sensitizers include thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthen-9-one, "KAYACURE" (registered trademark) DETX-S (manufactured by Nippon Kayaku Co., Ltd.). Two or more of these may be contained.

The coloring composition may further contain an organic solvent. Examples of organic solvents include diethylene glycol monobutyl ether acetate, benzyl acetate, ethyl benzoate, methyl benzoate, diethyl malonate, 2-ethylhexyl acetate, 2-butoxyethyl acetate, ethylene glycol monobutyl ether acetate, diethyl oxalate, ethyl acetoacetate, cyclohexyl acetate, 3-methoxy-butyl acetate, methyl acetoacetate, ethyl-3-ethoxypropionate, 2-ethylbutyl acetate, isopentyl propionate, propylene glycol monomethyl ether propionate, pentyl acetate, propylene glycol monomethyl ether acetate, ethylene Examples of the ethylene glycol monomethyl ether include ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, monoethyl ether, methyl carbitol, ethyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether, ethyl acetate, butyl acetate, isopentyl butanol acetate, 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, cyclopentanone, cyclohexanone, xylene, ethylbenzene, and solvent naphtha. Two or more of these may be contained.

When the color filter of the present invention has a red subpixel, the hue of the red subpixel is preferably such that a ^* is 70 or more and 80 or less, and b ^* is 30 or more and 40 or less in the L ^* a ^* b ^* color system chromaticity coordinates (a ^* , b ^* ) measured with a D65 light source. By satisfying these, a display excellent in saturation and brightness can be obtained in red display of electronic paper. In addition, from the viewpoint of display brightness, L ^* in the L ^* a ^* b ^* color system chromaticity diagram measured with the red subpixel with a D65 light source is preferably 55 or more, more preferably 60 or more.

When the color filter of the present invention has a green subpixel, the hue of the green subpixel is preferably such that a ^* is -80 or more and -70 or less, and b ^* is 40 or more and 60 or less in the L ^* a ^* b ^* color system chromaticity coordinates (a ^* , b ^* ) measured with a D65 light source. By satisfying these, a display excellent in saturation and brightness can be obtained in green display of electronic paper. Furthermore, from the viewpoint of display brightness, L ^* in the L ^* a ^* b ^* color system chromaticity diagram measured with the green subpixel with a D65 light source is preferably 80 or more, and more preferably 85 or more.

When the color filter of the present invention has a blue subpixel, the hue of the blue subpixel is preferably such that a ^* is 20 or more and 30 or less, and b ^* is -80 or more and -70 or less in the L ^* a ^* b ^* color system chromaticity coordinates (a ^* , b ^* ) measured with a D65 light source. By satisfying these, a display excellent in saturation and brightness can be obtained in blue display of electronic paper. Furthermore, from the viewpoint of display brightness, L ^* in the L ^* a ^* b ^* color system chromaticity diagram measured with the blue subpixel with a D65 light source is preferably 40 or more, and more preferably 45 or more.

The hue of the fourth subpixel, in the L ^* a ^* b ^* color system chromaticity coordinates (a ^* , b ^* ) measured with a D65 light source, is preferably such that a ^* is −5 to 7 and b ^* is −7 to 5. By satisfying these conditions, the white display of the electronic paper can be brightened.

When the color filter of the present invention has a yellow subpixel, the hue of the yellow subpixel is preferably such that a ^* is -50 or more and -20 or less, and b ^* is 80 or more and 100 or less in the L ^* a ^* b ^* color system chromaticity coordinates (a ^* , b ^* ) measured with a D65 light source. By satisfying these, a display excellent in saturation and brightness can be obtained when displaying yellow on electronic paper. In addition, from the viewpoint of display brightness, L ^* in the L ^* a ^* b ^* color system chromaticity diagram measured with the yellow subpixel with a D65 light source is preferably 85 or more, and more preferably 90 or more.

Regarding the arrangement of subpixels in the color filter of the present invention, when the color filter has red, green, and blue subpixels, an example of the arrangement shown in FIG. 1 can be mentioned, but is not limited to this. Furthermore, when the color filter has red, green, blue, and a fourth subpixel, an example of the arrangement shown in FIG. 2 and FIG. 4 can be mentioned, but is not limited to this. Furthermore, when the color filter has red, green, blue, and yellow subpixels, an example of the arrangement shown in FIG. 3 and FIG. 5 can be mentioned, but is not limited to this.

The film thickness of the subpixel is preferably 0.5 μm or more and 3.0 μm or less. By making it 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.4 μm or more, it is possible to improve the color purity. On the other hand, by making it 3.0 μm or less, more preferably 2.8 μm or less, it is possible to improve the flatness, pattern processability, and reliability of the color filter.

When the color filter of the present invention has a red subpixel, where M is the area of one pixel and R is the colored area of the red subpixel, from the viewpoint of making the red display vivid, R/M is preferably 0.16 or more, and more preferably 0.17 or more. The area M of one pixel includes the smallest repeating unit of a group of red, green, blue, yellow, etc. subpixels and the area between adjacent subpixels where these subpixels are the closest subpixels. The area M of one pixel can be measured as the average area of 50 pixels near the center of the color filter. The colored area of the subpixel can be measured as the average area of 50 subpixels of that color near the center of the color filter substrate.

When the color filter of the present invention has a green subpixel, when the colored area of the green subpixel is G, from the viewpoint of making the green display vivid, G/M is preferably 0.16 or more, and G0.17 or more is more preferable.

When the color filter of the present invention has a blue subpixel, where M is the area of the minimum repeating unit and B is the colored area of the blue pixel, from the viewpoint of making the blue display vivid, B/M is preferably 0.16 or more, and more preferably 0.17 or more.

When the color filter of the present invention has a yellow subpixel, where the area of the minimum repeating unit is M and the colored area of the yellow pixel is Y, from the viewpoint of making the yellow display vivid, Y/M is preferably 0.16 or more, and more preferably 0.17 or more.

The shape of the sub-pixels may be rectangular, such as a rectangle or a square, or may be circular or elliptical. From the viewpoint of improving the accuracy of bonding the array substrate and the color filter, a square shape is preferable for the sub-pixels.

The color filter of the present invention has a color-adjusting member between subpixels. In the present invention, the color-adjusting member refers to a member formed between subpixels, which has a Y value of 70 or more and 98 or less in the CIE 1931 color system. By having a color-adjusting member between subpixels, it is possible to display a bright white color with low saturation when displaying white. The white display referred to here refers to a display method when the color filter is adjusted so that the light passing through the entire filter is maximized.

In particular, when red, green, and blue, as well as yellow, subpixels are present, the saturation of white display tends to be high, making it necessary to adjust the size of the subpixels. However, by using a color-adjusting component with a Y value of 70 or more and 98 or less in the CIE 1931 color system, the saturation of white display can be improved, allowing a brighter white color with lower saturation to be displayed more effectively.

It is preferable that the composition for forming a color-adjusting member of the present invention has a Y value of 70 or more and 98 or less in the CIE 1931 color system when made into a film having a thickness of 2 μm. In this way, the composition for forming a color-adjusting member can efficiently form a color-adjusting member in the color filter of the present invention.

Examples of materials constituting the color-adjusting member forming composition that forms the color-adjusting member include compositions containing color materials and binder resins such as acrylic resins and polyimide resins.

Coloring materials contained in the color adjusting member or the composition for forming the color adjusting member include organic pigments, inorganic pigments, dyes, etc., and two or more of these may be contained. Among these, organic pigments are preferred from the viewpoint of light resistance.

Examples of red colorants for the composition for forming the color adjusting member include C.I. Pigment Red (hereinafter referred to as "PR") 9, PR48, PR97, PR122, PR123, PR144, PR149, PR166, PR168, PR177, PR179, PR180, PR192, PR209, PR215, PR216, PR217, PR220, PR223, PR224, PR226, PR227, PR228, PR240, PR254, and diketopyrrolopyrrole colorants having bromine groups.

Examples of green colorants for the composition for forming the color adjusting member include C.I. Pigment Green (hereinafter referred to as "PG") PG1, PG2, PG4, PG7, PG8, PG10, PG13, PG14, PG15, PG17, PG18, PG19, PG26, PG36, PG38, PG39, PG45, PG48, PG50, PG51, PG54, PG55, PG58, and PG59.

Examples of yellow colorants for the composition for forming the color adjusting member include C.I. Pigment Yellow (hereinafter referred to as "PY") 12, PY13, PY17, PY20, PY24, PY83, PY86, PY93, PY95, PY109, PY110, PY117, PY125, PY129, PY137, PY138, PY139, PY147, PY148, PY150, PY153, PY154, PY166, PY168, and PY185.

Examples of orange colorants for the color-adjusting member forming composition include C.I. Pigment Orange (hereinafter, "PO") 13, PO31, PO36, PO38, PO40, PO42, PO43, PO51, PO55, PO59, PO61, PO64, PO65, and PO71.

Examples of blue colorants for the composition for forming the color adjusting member include C.I. Pigment Blue (hereinafter referred to as "PB") 15, PB15:3, PB15:4, PB15:6, PB21, PB22, PB60, and PB64.

Examples of purple colorants for the composition for forming the color adjusting member include C.I. Pigment Violet (hereinafter "PV") 19, PV23, PV29, PV30, PV32, PV37, PV40, and PV50 (all numbers are color index numbers).

The coloring material of the composition for forming the color-adjusting member may be a dye, and examples of the dye include oil-soluble dyes, acid dyes, direct dyes, basic dyes, and acid mordant dyes. The dyes may also be made into lakes, or may be salt-forming compounds of the dyes and nitrogen-containing compounds.

Examples of red, green, blue, purple or yellow dyes include direct dyes, acid dyes, and basic dyes. Specific examples of these dyes include azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, xanthene dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluoran dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. The dyes may be dissolved in the coloring composition or dispersed as particles.

The coloring material contained in the color-adjusting member or the composition for forming the color-adjusting member may be any coloring material, such as a red coloring material, a yellow coloring material, a blue coloring material, or a purple coloring material. However, from the viewpoint of displaying a bright white color with low saturation in a white display, a blue coloring material or a purple coloring material is preferred, and a purple coloring material is more preferred.

In addition, as coloring materials contained in the color adjusting member, PR254, diketopyrrolopyrrole coloring materials having a bromine group, PR177, PY150, PY185, PG58, PG59, PB15:3, PB15:4, PB15:6, PV23, etc. can be used. Among them, from the viewpoint of displaying a bright white color with low saturation in white display, PG58, PG59, PB15:6, and PV23 are preferred, more preferably PB15:6, PV23, and even more preferably PV23.

The content of the coloring material contained in the color adjusting member or the composition for forming the color adjusting member is preferably 0.01% by mass or more of the solid content, from the viewpoint of displaying a low saturation and bright white color in the white display, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. Also, from the viewpoint of displaying a low saturation and bright white color in the white display, the content is preferably 5% by mass or less of the solid content, more preferably 3% by mass or less, and even more preferably 1% by mass or less. The solid content here refers to all components contained in the color adjusting member or the composition for forming the color adjusting member, excluding the organic solvent.

The color-adjusting member forming composition may contain a radically polymerizable compound. Examples of radically polymerizable compounds contained in the color-adjusting member forming composition include ethylene oxide modified products or propylene oxide modified products such as dipentaerythritol penta(meth)acrylate, tetratrimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester, dipentaerythritol hexa(meth)acrylate, styrene derivatives, polyfunctional maleimide compounds, poly(meth)acrylate carbamates, and adipic acid 1,6-hexanediol(meth)acrylic acid esters. , phthalic anhydride propylene oxide (meth)acrylic acid ester, trimellitic acid diethylene glycol (meth)acrylic acid ester, rosin-modified epoxy di(meth)acrylate, alkyd-modified (meth)acrylate and other oligomers, tripropylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate and other bifunctional (meth)acrylates, trimethylolpropane tri(meth)acrylate, triacrylformal, bisphenoxyethanol fluorene diacrylate, dicyclopentanedienyl diacrylate, alkyl-modified products thereof, alkyl ether-modified products thereof, alkyl ester-modified products thereof, etc. Two or more of these may be contained.

The radical polymerizable compound contained in the composition for forming the color adjusting member contains dipentaerythritol hexa(meth)acrylate and pentaerythritol tri(meth)acrylate, and the ratio A/B of the mass (A) of dipentaerythritol hexa(meth)acrylate to the mass (B) of pentaerythritol tri(meth)acrylate is preferably 0.16 or more and 3 or less. By making it 0.16 or more, more preferably 0.17 or more, and even more preferably 0.3 or more, it is possible to achieve excellent patterning properties and to make it difficult for the pattern to peel off even when fired at a low temperature. In addition, by making A/B 2.4 or less, more preferably 1.6 or less, it is possible to suppress color mixing of the pattern. In particular, when the base material of the color filter is an organic plastic film or sheet made of polyethylene terephthalate (PET), firing at a low temperature is required, so it is preferable that the radical polymerizable compound satisfies the above A/B.

From the viewpoint of patterning, the content of the radical polymerizable compound is preferably 40% by mass or more in the solid content of the composition for forming a color-adjusting member. On the other hand, from the viewpoint of suppressing unevenness in the film thickness during film formation and suppressing deformation of the pattern due to flow during firing, the content of the radical polymerizable compound is preferably 90% by mass or less in the solid content of the composition for forming a color-adjusting member, more preferably 70% by mass or less, and even more preferably 60% by mass or less. Also, from the viewpoint of patterning, the content of the radical polymerizable compound having three or more (meth)acryloyl groups and carboxyl groups is preferably 50% by mass or more in the radical polymerizable compound, and even more preferably 60% by mass or more.

The color-adjusting member forming composition may further contain binder resins, dispersants, photopolymerization initiators, chain transfer agents, sensitizers, organic solvents, polymerization inhibitors, adhesion improvers, surfactants, organic acids, organic amino compounds, curing agents, crosslinking agents, etc.

Examples of binder resins contained in the composition for forming color-adjusting members include acrylic resins, epoxy resins, polyimide resins, urethane resins, urea resins, polyvinyl alcohol resins, melamine resins, polyamide resins, polyamideimide resins, polyester resins, and polyolefin resins. Two or more of these may be contained. From the viewpoint of stability, acrylic resins are preferred. Furthermore, these resins preferably have functional groups that react when heated. By having functional groups that react when heated, they can be suitably used for color-adjusting members formed by photolithography processing or color-adjusting members formed by applying with an inkjet or the like, drying, and baking.

As the acrylic resin, a copolymer of an unsaturated carboxylic acid and an ethylenically unsaturated compound is preferred.

Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid, and acid anhydrides thereof. Two or more of these may be used.

Examples of ethylenically unsaturated compounds include unsaturated carboxylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and benzyl (meth)acrylate; aromatic vinyl compounds such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, and α-methylstyrene; and aminoethyl Examples of the monomer include unsaturated carboxylic acid amino alkyl esters such as acrylate, unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate and glycidyl methacrylate, carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate, cyanide vinyl compounds such as acrylonitrile, methacrylonitrile and α-chloroacrylonitrile, aliphatic conjugated dienes such as 1,3-butadiene and isoprene, and macromonomers such as polystyrene having a (meth)acryloyl group at the end, polymethyl acrylate, polymethyl methacrylate, polybutyl acrylate, polybutyl methacrylate, and polysilicone. Two or more of these may be used.

It is preferable that the acrylic resin has an ethylenically unsaturated group in the side chain, which can improve sensitivity. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acrylic group, and a methacrylic group. Examples of the acrylic resin having an ethylenically unsaturated group in the side chain include "Cyclomer" (registered trademark) P (Daicel Chemical Industries, Ltd.) and an alkali-soluble cardo resin.

From the viewpoint of the strength of the cured film, the weight average molecular weight of the binder resin is preferably 3,000 or more, and more preferably 9,000 or more. On the other hand, from the viewpoint of the stability of the coloring composition, the weight average molecular weight of the binder resin is preferably 200,000 or less, and more preferably 100,000 or less. Here, the weight average molecular weight of the binder resin refers to a standard polystyrene equivalent value measured by gel permeation chromatography.

From the viewpoint of suppressing unevenness in the film thickness during film formation, the content of the binder resin is preferably 10% by mass or more of the solid content, more preferably 20% by mass or more, and even more preferably 30% by mass or more. On the other hand, from the viewpoint of patterning properties, the content of the binder resin is preferably 60% by mass or less of the solid content, and more preferably 50% by mass or less.

The coloring materials contained in the color-adjusting member and the composition for forming the color-adjusting member of the present invention can be identified by laser Raman spectroscopy (Ar+ laser (457.9 nm)) or mass analysis using a MALDI mass spectrometer or a time-of-flight secondary ion mass spectrometer.

Examples of dispersants contained in the composition for forming a color-adjusting member include polyester, polyalkylamine, polyallylamine, polyimine, polyamide, polyurethane, polyacrylate, polyimide, polyamideimide, and copolymers thereof. Two or more of these may be contained. Among these polymer dispersants, those having an amine value of 5 mg KOH/g or more and 200 mg KOH/g or less and an acid value of 1 mg KOH/g or more and 100 mg KOH/g or less in terms of solid content are preferred. Among them, polymer dispersants having basic groups are preferred, and can improve the storage stability of the pigment dispersion liquid and the coloring composition. Examples of commercially available polymer dispersants having basic groups include "Solsperse" (registered trademark) (manufactured by Avecia), "EFKA" (registered trademark) (manufactured by EFKA), "Ajisper" (registered trademark) (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and "BYK" (registered trademark) (manufactured by BYK-Chemie). Two or more of these may be contained. Among these, "Solsperse" (registered trademark) 24000 (manufactured by Avecia), "EFKA" (registered trademark) 4300, 4330 (manufactured by EFKA), 4340 (manufactured by EFKA), "Ajisper" (registered trademark) PB821, PB822 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), and "BYK" (registered trademark) 161-163, 2000, 2001, 6919, 21116 (manufactured by BYK-Chemie) are preferred.

The color-adjusting member forming composition may contain a photopolymerization initiator. Examples of photopolymerization initiators contained in the color-adjusting member forming composition include oxime ester compounds, benzophenone compounds, acetophenone compounds, oxanthone compounds, anthraquinone compounds, imidazole compounds, benzothiazole compounds, benzoxazole compounds, carbazole compounds, triazine compounds, phosphorus compounds, and titanocene compounds.

More specifically, examples of oxime ester compounds include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), ethano Examples of the benzophenone compounds include benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone. Examples of the benzophenone compounds include benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone. Examples of acetophenone compounds include 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutylphenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propane, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and "IRGACURE" (registered trademark) 369, 379, and 907 (manufactured by BASF Ltd.). Examples of the anthraquinone compounds include t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, and 2-phenylanthraquinone. Examples of the imidazole compounds include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer. Examples of the benzothiazole compounds include 2-mercaptobenzothiazole. Examples of the benzoxazole compounds include 2-mercaptobenzoxazole. Examples of the triazine compounds include 4-(p-methoxyphenyl)-2,6-di-(trichloromethyl)-s-triazine. Two or more of these may be contained. Among these, from the viewpoint of processability, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one is preferred, and it is even more preferred to use a sensitizer described below in addition to 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

From the viewpoints of sensitivity, patterning ability, and processability, the content of the photopolymerization initiator is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, of the solid content of the composition for forming the color adjusting member. On the other hand, from the viewpoints of sensitivity, patterning ability, processability, and heat resistance, the content of the photopolymerization initiator is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, of the solid content of the composition for forming the color adjusting member.

The composition for forming a color-adjusting member may contain a chain transfer agent. Examples of chain transfer agents contained in the composition for forming a color-adjusting member include thioglycolic acid, thiomalic acid, thiosalicylic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N-(2-mercaptopropionyl)glycine, 2-mercaptonicotinic acid, 3-[N-(2-mercaptoethyl)carbamoyl]propionic acid, 3-[N-(2-mercaptoethyl)amino]propionic acid, N-(3-mercaptopropionyl)alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, dodecyl(4-methylthio)phenyl ether, 2-mercaptoethanol, 3-mercaptobutyric acid, 3-mercaptopropanol, 3-mercaptobutanol, 3-mercaptoprop ... Mercapto-1,2-propanediol, 1-mercapto-2-propanol, 3-mercapto-2-butanol, mercaptophenol, 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol, 2-mercaptobenzothiazole, mercaptoacetic acid, trimethylolpropane tris(3-mercaptopropionate), 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione), pentaerythritol tetrakis(3-mercaptopropionate), 1,4-bis(3-mercaptobutyryloxy)butane, Karenz (registered trademark) MT Examples of such mercapto compounds include PE-1 (manufactured by Showa Denko K.K.), Karenz (registered trademark) MT NR-1 (manufactured by Showa Denko K.K.), Karenz (registered trademark) MT BD-1 (manufactured by Showa Denko K.K.), and the like; disulfide compounds obtained by oxidizing such mercapto compounds; and iodized alkyl compounds such as iodoacetic acid, iodopropionic acid, 2-iodoethanol, 2-iodoethanesulfonic acid, and 3-iodopropanesulfonic acid. Two or more of these may be contained.

The color-adjusting member-forming composition may contain a sensitizer. Examples of sensitizers contained in the color-adjusting member-forming composition include thioxanthone-based sensitizers and aromatic or aliphatic tertiary amines. Examples of thioxanthone-based sensitizers include thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthen-9-one, "KAYACURE" (registered trademark) DETX-S (manufactured by Nippon Kayaku Co., Ltd.). Two or more of these may be contained.

The color-adjusting member forming composition may contain a crosslinking agent. The crosslinking agent contained in the color-adjusting member forming composition refers to a compound having a functional group that reacts with heat, such as an epoxy group, a methylol group, an alkoxymethyl group, an isocyanate group, or a blocked isocyanate group. The epoxy group referred to here refers to a glycidyl group, an oxetanyl group, or an alicyclic epoxy group. The crosslinking agent contained in the color-adjusting member forming composition may be, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, glycerin ... glycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,-diglycidyl-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, and commercially available products with an average of 3.7 methoxymethyl groups substituted per triazine ring. MX-750, MW-30, MX-100LM (all manufactured by Sanwa Chemical Co., Ltd.), which have an average of 5.8 methoxymethyl groups per triazine ring, methoxymethylated melamines such as Cymel 300, 301, 303, 350, 370, 771, 325, 327, 703, 712, methoxymethylated butoxymethylated melamines such as Cymel 235, 236, 238, 212, 253, 254, butoxymethylated melamines such as Cymel 506, 508, and carbamides such as Cymel 1141. Examples include, but are not limited to, carboxyl group-containing methoxymethylated isobutoxymethylated melamine, methoxymethylated ethoxymethylated benzoguanamine such as Cymel 1123, methoxymethylated butoxymethylated benzoguanamine such as Cymel 1123-10, butoxymethylated benzoguanamine such as Cymel 1128, and carboxyl group-containing methoxymethylated ethoxymethylated benzoguanamine such as Cymel 1125-80 (all manufactured by Mitsui Cyanamid Co., Ltd.).

The color-adjusting member forming composition may further contain an organic solvent. Examples of organic solvents include diethylene glycol monobutyl ether acetate, benzyl acetate, ethyl benzoate, methyl benzoate, diethyl malonate, 2-ethylhexyl acetate, 2-butoxyethyl acetate, ethylene glycol monobutyl ether acetate, diethyl oxalate, ethyl acetoacetate, cyclohexyl acetate, 3-methoxy-butyl acetate, methyl acetoacetate, ethyl-3-ethoxypropionate, 2-ethylbutyl acetate, isopentyl propionate, propylene glycol monomethyl ether propionate, pentyl acetate, propylene glycol monomethyl ether acetate, ethylene Examples of the ethylene glycol monomethyl ether include ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, monoethyl ether, methyl carbitol, ethyl carbitol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol tertiary butyl ether, dipropylene glycol monomethyl ether, ethyl acetate, butyl acetate, isopentyl butanol acetate, 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, cyclopentanone, cyclohexanone, xylene, ethylbenzene, and solvent naphtha. Two or more of these may be contained.

The color-adjusting member may be formed by applying a color-adjusting member-forming composition by inkjet or the like, followed by drying and baking, or by applying a photosensitive color-adjusting member-forming composition by slit coating or the like, followed by drying, mask exposure, development, and baking (photolithography). From the viewpoint of processing dimensional accuracy, it is preferable to form the color-adjusting member by photolithography using a photosensitive color-adjusting member-forming composition.

From the viewpoint of processability, the film thickness of the color-adjusting member is preferably 0.5 μm or more, and more preferably 1.0 μm or more. Also, from the viewpoint of flatness and processability, the film thickness of the color-adjusting member is preferably 3.0 μm or less, and more preferably 2.8 μm or less.

From the viewpoint of displaying a bright and good white color with low saturation in white display, it is preferable that the transmittance of the color-adjusting member is such that the transmittance T450 at a wavelength of 450 nm is 90% or more, the transmittance T550 at a wavelength of 550 nm is 65% to 98%, and the transmittance T700 at a wavelength of 700 nm is 80% or more.

The ratio H/M of the area H of the color-adjusting member to the area M of one pixel is preferably 0.05 or more, and more preferably 0.10 or more, from the viewpoint of displaying a bright and good white color with low saturation in the white display. Also, from the viewpoint of displaying each color vividly, it is preferably 0.36 or less, more preferably 0.30 or less, and even more preferably 0.20 or less.

From the viewpoint of displaying each color brightly and vividly, it is preferable to form the color adjustment member in the center between the pixels, but it is also possible to narrow the distance between the color adjustment member and the subpixel of a particular color while widening the distance between the color adjustment member and the subpixel of another color. The distance between the color adjustment member and each pixel may be 0 μm, or it may be several μm to several tens of μm, or it may be several hundred μm. From the viewpoint of displaying vivid colors, the distance between the color adjustment member and each pixel is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less.

The shape of the color-adjusting member may be a shape that surrounds each pixel as in Figures 1, 2, 3, and 5, or may be rectangular as in Figure 4, or may be circular, elliptical, star-shaped, wavy, or other shapes.

In order to display a bright white color with low saturation in white display, it is preferable to arrange the color adjustment member between two or more combinations of subpixels, such as between red and green subpixels and between red and blue subpixels, and more preferably to arrange the color adjustment member between three or more combinations of subpixels, such as between red and green subpixels, between red and blue subpixels, and between green and blue subpixels, and the more combinations of subpixels between which the color adjustment member is arranged, the better. Note that the combinations of subpixels between which the color adjustment member is arranged are not limited to the above examples.

As an example of the arrangement of the color-adjusting members and subpixels, as shown in FIG. 1, square red, green, and blue subpixels are repeatedly arranged, and the color-adjusting members are formed between these subpixels. Note that the positional relationship between the red, green, and blue subpixels is not particularly limited to the embodiment shown in FIG. 1.

For example, as shown in FIG. 2, a square red, green, and blue subpixels and a fourth subpixel may be repeatedly arranged, with color-adjusting members formed between these subpixels. Note that the positional relationship between the red, green, blue, and fourth subpixels is not particularly limited to the embodiment shown in FIG. 2.

For example, as shown in FIG. 3, square red, green, blue and yellow subpixels can be repeatedly arranged, with color-adjusting members formed between these subpixels. Note that the positional relationship between the red, green, blue and yellow subpixels is not particularly limited to the embodiment shown in FIG. 3.

For example, as shown in FIG. 4, a square red, green, and blue subpixels and a fourth subpixel may be repeatedly arranged, and a color-adjusting member may be formed between these subpixels so as to surround a portion of each color pixel. Note that the positional relationship between the red, green, blue, and fourth subpixels is not particularly limited to the embodiment shown in FIG. 4.

For example, as shown in FIG. 5, square red, green, blue and yellow subpixels can be repeatedly arranged, and color-adjusting members can be formed adjacent to these subpixels. Note that the positional relationship of the red, green, blue and yellow subpixels is not particularly limited to the embodiment shown in FIG. 5.

The width of the color-adjusting member is preferably 5 μm or more, and more preferably 8 μm or more, from the viewpoint of the workability of the color-adjusting member and displaying a bright white color with low saturation in the white display. Furthermore, from the viewpoint of displaying a bright white color with low saturation in the white display, the width of the color-adjusting member is preferably 40 μm or less, and more preferably 30 μm or less. The width of the color-adjusting member here refers to the length of the color-adjusting member in the direction of the spacing between adjacent subpixels.

The color filter of the present invention may further have a black matrix. The black matrix prevents a decrease in contrast and color purity due to light leakage between pixels, and may be disposed between subpixels, a part between subpixels, or in the frame. Examples of materials constituting the black matrix include a photosensitive composition containing a binder resin such as an acrylic resin or a polyimide resin and a radical polymerizable compound, and a non-photosensitive resin composition colored black. From the viewpoint of light shielding, the film thickness of the black matrix is preferably 0.5 μm or more, and more preferably 1.0 μm or more. On the other hand, from the viewpoint of processability, it is preferably 2.0 μm or less, and more preferably 1.5 μm or less.

The color filter of the present invention may further have an overcoat layer. The overcoat layer suppresses the transmission of impurities from the subpixels of the color filter and flattens the steps caused by the subpixels of the color filter. Examples of materials constituting the overcoat layer include epoxy resins, acrylic epoxy resins, acrylic resins, siloxane resins, polyimide resins, and photosensitive or non-photosensitive materials that are commercially available as flattening materials. From the viewpoint of processability, the film thickness of the overcoat layer is preferably 0.5 μm or more, and more preferably 1.0 μm or more. On the other hand, from the viewpoint of flatness of the color filter, it is preferably 5.0 μm or less, and more preferably 3.0 μm or less.

The color filter of the present invention may further have a transparent electrode. Examples of materials constituting the transparent electrode include metals such as aluminum, chromium, tantalum, titanium, neodymium, and molybdenum, indium-tin-oxide (ITO), and indium-zinc-oxide (InZnO).

The color filter of the present invention may further include a diffusion plate, etc.

The manufacturing method will be described below using as examples a color filter having a color adjusting member made of a photosensitive color adjusting member forming composition and a subpixel made of a photosensitive coloring composition.

A color filter can be obtained by applying a color-adjusting component-forming composition or a coloring composition onto a substrate, patterning the composition by selective exposure and development using a photomask, and then baking the composition to form color-adjusting components and subpixels.

Methods for applying the color adjusting member forming composition or coloring composition for forming the color adjusting member or subpixel onto the substrate include, for example, a spin coater, a bar coater, a blade coater, a roll coater, a die coater, an inkjet printing method, a screen printing method, a method of immersing the substrate in the color adjusting member forming composition or coloring composition, and a method of spraying the color adjusting member forming composition or coloring composition onto the substrate.

Then, the substrate coated with the composition for forming a color adjusting member or the coloring composition is dried to form a coating film of the composition for forming a color adjusting member or the coloring composition on the substrate. Examples of drying methods include air drying, heat drying, and vacuum drying. Two or more of these methods may be combined, and for example, it is preferable to perform reduced pressure drying followed by heat drying. The heat drying temperature is preferably 80 to 130°C, and a hot air oven or a hot plate is preferable as the heat drying device. In the case of a color filter having a black matrix, it is preferable to form a coating film of the coloring composition on a substrate on which a black matrix has been formed in advance.

Next, a photomask is placed on the coating film of the color-adjusting member-forming composition or the coloring composition, and selective exposure is performed. Examples of exposure machines include proximity exposure machines, mirror projection exposure machines, lens scan exposure machines, steppers, etc. From the viewpoint of accuracy, lens scan exposure machines are preferred. Examples of light sources used for exposure include ultra-high pressure mercury lamps, chemical lamps, high pressure mercury lamps, etc.

Thereafter, the unexposed areas are removed by development with an alkaline developer to form a coating film pattern. Examples of alkaline substances used in the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldiethylamine; and organic alkalis such as tetramethylammonium hydroxide. Examples of the alkaline developer include 0.02 to 1% by mass of potassium hydroxide or tetramethylammonium hydroxide. Examples of the development method include a method in which the exposed coating film is immersed in an alkaline developer for 20 to 300 seconds.

The resulting coating film pattern is then heat-treated to obtain a color filter in which the color-adjusting members and sub-pixels are patterned. The heat treatment may be performed in air, in a nitrogen atmosphere, or in a vacuum. The heating temperature is preferably 150 to 350°C, and more preferably 180 to 250°C. The heating time is preferably 5 minutes to 5 hours. As the heat treatment device, a hot air oven or a hot plate is preferable. The heat treatment may be performed continuously or stepwise.

The order in which the color-adjusting members and sub-pixels are formed may be such that the sub-pixels are formed first, and then the color-adjusting members, or the sub-pixels are formed first. In addition, when the color filter has sub-pixels of multiple colors, the pixels are formed sequentially for each sub-pixel by the above method. There are no particular limitations on the order in which the colors are formed.

The color filter of the present invention can be used as a component of display devices such as liquid crystal displays, organic EL displays, and electronic paper.

That is, the display device of the present invention is characterized by having the color filter of the present invention. The display device refers to a device that displays an image by allowing a part of the screen to be viewed by a display element. Examples of the display element include a liquid crystal element, an organic EL element, an inorganic EL element, a display element using MEMS, a display element using quantum dots, electronic ink, electronic liquid powder, and an electrophoretic element. Examples of the display device include a transmissive liquid crystal display, a semi-transmissive liquid crystal display, a reflective liquid crystal display, an organic EL display, an inorganic EL display, a quantum dot display, and electronic paper. Examples of the reflective display device include devices that display using outdoor light or indoor light, such as wearable terminals, electronic signs, digital signage, and electronic shelf labels. In addition to the color filter and display element of the present invention, the display device may also have a light source such as an external light source, and various films such as a brightness enhancement film and a diffusion plate.

The electronic paper of the present invention is characterized by having the color filter of the present invention. The display method of the electronic paper can be an electrophoretic method using an electrophoretic display layer. The electrophoretic display layer refers to a member having a display medium that switches between black and white display by moving white and black particles using an electric field. The electrophoretic display layer can be, for example, a microcapsule containing a dispersion liquid made of a transparent dispersion medium and fixed with a binder resin. The transparent dispersion medium can be, for example, various organic compounds such as alcohol-based solvents and aliphatic hydrocarbons. The white particles can be, for example, a white pigment such as titanium dioxide, and the black particles can be, for example, a black pigment such as carbon black and titanium black. The material for forming the wall film of the microcapsule can be, for example, a urethane resin, a urea resin, a composite film of gum arabic and gelatin, or the like. The binder resin can be one that has good affinity with the wall film of the microcapsule and has insulating properties. Such an electrophoretic display layer can be formed, for example, by dispersing the microcapsules in a binder resin and applying the ink made by dispersing the microcapsules in the binder resin.

In addition to the color filter and electrophoretic display layer of the present invention, the electronic paper may also have an optical film for improving visibility and light reflection characteristics, a surface protection film, a barrier layer, a touch panel layer, etc.

When the color filter of the present invention in the electronic paper of the present invention has a combination of red, green, and blue subpixels, or a combination of red, green, blue, and yellow subpixels, it is preferable to make the reflectance of the portion of the electrophoretic display layer in the electronic paper corresponding to the blue subpixel greater than the reflectance of the portion corresponding to any of the other subpixels in order to display a white color closer to white when the electronic paper displays white. This embodiment is particularly useful when the electronic paper has red, green, blue, and yellow subpixels, as the white display tends to have a yellowish tinge. The white display referred to here refers to the white display used in the background of characters when characters are displayed on the electronic paper. In this way, by controlling the reflectance corresponding to the color of the subpixels, it is possible to display a white color closer to white while making each color displayed more vivid.

The present invention will be explained below with reference to examples, but the present invention is not limited to these examples. First, the evaluation methods used in the examples and comparative examples will be explained.

[Measurement and evaluation method]
(1) Chromaticity, Y value, and transmittance of color-adjusting member For the color-adjusting members obtained in the examples, chromaticity xy, CIE 1931 color system tristimulus value (Y), transmittance T450 at 450 nm, transmittance T550 at 550 nm, and transmittance T700 at 700 nm were measured using a microspectrophotometer (LCF-100MA manufactured by Otsuka Electronics Co., Ltd.).

(2) Evaluation of White Display The color filters of each Example and Comparative Example were attached to an array substrate, and the L ^* and chroma when the reflection intensity of the sub-pixel portion of each color was maximized (hereinafter, white display) were measured using a spectrophotometer (CM2600d manufactured by Konica Minolta, Inc.).

[Example 1]
(Preparation of Dispersion A1)
In a 500 mL three-neck flask under a nitrogen atmosphere, 176.3 g of anhydrous tert-amyl alcohol (2.0 mol) and 114.7 g of sodium tert-amyl alkoxide (1.1 mol) were placed, and the internal temperature was raised to 100° C. with stirring to react them, thereby preparing an alcoholate solution.

In a separate 500 mL three-neck flask, 84.9 g of diisopropyl succinate (0.4 mol) and 145.6 g of 4-bromobenzonitrile (0.8 mol) were charged, and the internal temperature was raised to 85°C while stirring to dissolve the mixture, preparing a mixed solution.

The internal temperature of the three-neck flask containing the alcoholate solution was adjusted to 100°C, and the mixed solution was added dropwise over a period of 3 hours while stirring. After the addition was complete, the mixture was heated and stirred at an internal temperature of 90°C for 12 hours to obtain a suspension.

In another 500 mL three-neck flask, 640 g of methanol (20.0 mol), 720 g of water (40.0 mol), and 300 g of acetic acid (10.0 mol) were charged and stirred while cooling the internal temperature to -10°C to obtain a mixture.

The suspension was added dropwise over a period of 3 hours while stirring at high speed and keeping the internal temperature of the three-neck flask containing the mixture at -5°C or below. After the addition was completed, the mixture was stirred for an additional 7 hours, and then the reaction liquid was washed and filtered until the filtrate was no longer colored and no salt precipitated. The collected filtrate was dried at 80°C for 24 hours, and the resulting solid was pulverized to obtain 112 g of a diketopyrrolopyrrole pigment having a bromine group represented by general formula (1).

100 g of the obtained diketopyrrolopyrrole pigment having bromine groups, 50 g of polymer dispersant (BYK-6919, manufactured by BYK Japan Co., Ltd.), 66.7 g of binder polymer (Cyclomer (registered trademark) P, ACA250, 45% by weight solution, manufactured by Daicel Corporation), and 450 g of PGME were mixed to prepare a slurry. The beaker containing the slurry was connected to a Dyno Mill via a tube, and a dispersion process was carried out for 8 hours at a peripheral speed of 14 m/s using zirconia beads with a diameter of 0.5 mm as the medium, to prepare dispersion liquid A1 of diketopyrrolopyrrole pigment having bromine groups.

(Preparation of Dispersion A2)
C.I. Pigment Green 58 150g, polymer dispersant (BYK-6919 manufactured by BYK Japan Co., Ltd.) 75g, binder polymer (Daicel Corporation, Cyclomer (registered trademark) P, ACA250, 45 mass% solution) 100g, and PGME 675g were mixed to prepare a slurry. The beaker containing the slurry was connected to a Dyno Mill with a tube, and a dispersion treatment was performed for 8 hours at a peripheral speed of 14 m/s using zirconia beads having a diameter of 0.5 mm as a medium, to prepare a dispersion liquid A2 of Pigment Green 58.

(Preparation of Dispersion A3)
C.I. Pigment Yellow 150 150g, polymer dispersant (BYK-6919 manufactured by BYK Japan Co., Ltd.) 75g, binder polymer (Daicel Corporation, Cyclomer (registered trademark) P, ACA250, 45 mass% solution) 100g, and PGME 675g were mixed to prepare a slurry. The beaker containing the slurry was connected to a Dyno Mill with a tube, and a dispersion treatment was performed for 8 hours at a peripheral speed of 14 m/s using zirconia beads having a diameter of 0.5 mm as a medium, to prepare a dispersion A3 of Pigment Yellow 150.

(Preparation of Dispersion A4)
C.I. Pigment Blue 15:6 150g, polymer dispersant (BYK-6919 manufactured by BYK Japan Co., Ltd.) 75g, binder polymer (Daicel Corporation, Cyclomer (registered trademark) P, ACA250, 45 mass% solution) 100g, and PGME 675g were mixed to prepare a slurry. The beaker containing the slurry was connected to a Dyno Mill with a tube, and a dispersion treatment was performed for 8 hours at a peripheral speed of 14 m/s using zirconia beads having a diameter of 0.5 mm as a medium, to prepare a dispersion liquid A4 of Pigment Blue 15:6.

(Preparation of Dispersion A5)
C.I. Pigment Violet 23 150g, polymer dispersant (BYK-6919 manufactured by BYK Japan Co., Ltd.) 75g, binder polymer (Daicel Corporation, Cyclomer (registered trademark) P, ACA250, 45 mass% solution) 100g, and PGME 675g were mixed to prepare a slurry. The beaker containing the slurry was connected to a Dyno Mill with a tube, and a dispersion treatment was performed for 8 hours at a peripheral speed of 14 m/s using zirconia beads having a diameter of 0.5 mm as a medium, to prepare a dispersion liquid A5 of Pigment Violet 23.

(Synthesis of binder resin solution B1)
In a 500 mL three-neck flask, 33 g (0.3 mol) of methyl methacrylate, 33 g (0.3 mol) of styrene, 34 g (0.4 mol) of methacrylic acid, 3 g (0.02 mol) of 2,2'-azobis (2-methylbutyronitrile) and 150 g of propylene glycol monomethyl ether acetate (PGMEA) were charged, and the mixture was stirred at 90 ° C. for 2 hours, and then the internal temperature was raised to 100 ° C. and stirred for another 1 hour to obtain a reaction solution. To the resulting reaction solution, 33 g (0.2 mol) of glycidyl methacrylate, 1.2 g (0.009 mol) of dimethylbenzylamine and 0.2 g (0.002 mol) of p-methoxyphenol were added, and the mixture was stirred at 90 ° C. for 4 hours, and then 50 g of PGMEA was added to obtain a binder resin solution B1 having a solid content concentration of 40% by mass. The acid value of the binder resin was measured for a 0.1 mol/L potassium hydroxide-ethanol solution using an automatic potentiometer AT-610 manufactured by Kyoto Electronics Manufacturing Co., Ltd., and was found to be 80.0 (mgKOH/g). The weight average molecular weight in terms of polystyrene measured using a GPC device was 22,000.

(Preparation of Coloring Composition R)
Into a 50 mL plastic bottle, 5.42 g of Dispersion A1, 0.11 g of Dispersion A3, 3.11 g of Binder Resin Solution B1, 1.49 g of penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester (C1), 0.12 g of N-1919 (manufactured by ADEKA Corporation), and 19.75 g of dipropylene glycol methyl ether acetate (hereinafter, DPMA) were added and stirred for 3 hours to prepare a red coloring composition R.

(Preparation of Coloring Composition G)
Into a 50 mL plastic bottle, 6.40 g of Dispersion A2, 1.03 g of Dispersion A3, 3.11 g of Binder Resin Solution B1, 1.05 g of penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester (C1), 0.04 g of N-1919 (manufactured by ADEKA Corporation), and 18.35 g of DPMA were added and stirred for 3 hours to prepare a green coloring composition G.

(Preparation of Coloring Composition B)
Into a 50 mL plastic bottle, 2.09 g of Dispersion A4, 1.12 g of Dispersion A5, 3.24 g of Binder Resin Solution B1, 0.95 g of penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester (C1), 0.07 g of N-1919 (manufactured by ADEKA Corporation), and 21.36 g of DPMA were added and stirred for 3 hours to prepare a blue coloring composition B.

(Preparation of Coloring Composition Y)
Into a 50 mL plastic bottle, 2.60 g of Dispersion A2, 4.83 g of Dispersion A3, 3.11 g of Binder Resin Solution B1, 1.05 g of penta(meth)acryloyloxydipentaerythritol monosuccinic acid ester (C1), 0.04 g of N-1919 (manufactured by ADEKA Corporation), and 18.35 g of DPMA were added and stirred for 3 hours to prepare a yellow coloring composition Y.

(Preparation of color-adjusting member forming composition H1)
A 50 mL plastic bottle was charged with 0.06 g of the dispersion A5, 5.82 g of the binder resin solution B1, 1.42 g of dipentaerythritol hexaacrylate (D1) and 1.42 g of pentaerythritol triacrylate (D2) as radical polymerizable compounds, 0.10 g of IRGACURE907 (manufactured by BASF Ltd.) (E1) as a photopolymerization initiator, 0.10 g of 2,4-diethylthioxanthone (F1) as a photosensitizer, and 21.06 g of propylene glycol monomethyl ether acetate (G1) as an organic solvent, and the mixture was stirred for 3 hours to prepare a color adjusting member forming composition (H1).

(Red Sub-Pixel Formation)
The coloring composition R was applied by spin coating on a glass substrate having a thickness of 0.5 mm, and then heated and dried at 90°C for 10 minutes. The obtained coloring composition coating film was exposed to 200 mJ/ ^cm2 of i-line in an arrangement pattern as shown in FIG. 5 through a negative photomask, and then developed with a 0.3 mass% aqueous solution of tetramethylammonium hydroxide at 23°C. Subsequently, a heat treatment was performed at 230°C for 30 minutes to form a red subpixel. The red subpixel was a square with a side length of 129 μm, the length of the minimum repeating unit, i.e., the distance between the centers of adjacent subpixels of the same color, was 318 μm, and the color (L ^* , a ^* , b ^* ) of each color pixel in the L ^* a ^* b ^* color system chromaticity diagram measured with a D65 light source was (62.6, 70.2, 33.4).

(Green Sub-Pixel Formation)
The coloring composition G was applied by spin coating onto the substrate on which the red subpixel was formed, and then dried by heating at 90°C for 10 minutes. The obtained coloring composition coating film was exposed to 200 mJ/cm2 of i-line through a negative photomask in the positional relationship with the red subpixel as shown in FIG. 5, and ^then developed with a 0.3 mass% tetramethylammonium hydroxide aqueous solution at 23°C. Subsequently, a heat treatment was performed at 230°C for 30 minutes to form a green subpixel. The green subpixel was a square with a side length of 129 μm, the length of the minimum repeating unit, i.e., the distance between the centers of adjacent subpixels of the same color, was 318 μm, and the color (L ^* , a ^* , b ^* ) of each color pixel in the L ^* a ^* b ^* color system chromaticity diagram measured with a D65 light source was (85.8, -77.3, 50.7).

(Formation of blue sub-pixel)
The coloring composition B was applied by spin coating onto the substrate on which the red and green subpixels were formed, and then heated and dried at 90°C for 10 minutes. The obtained coloring composition coating film was exposed to 200 mJ/ ^cm2 of i-line through a negative photomask in the positional relationship with the red and green subpixels as shown in FIG. 5, and then developed with a 0.3 mass% tetramethylammonium hydroxide aqueous solution at 23°C. Subsequently, a heat treatment was performed at 230°C for 30 minutes to form a blue subpixel. The blue subpixel was a square with a side length of 129 μm, the length of the minimum repeating unit, i.e., the distance between the centers of adjacent subpixels of the same color, was 318 μm, and the color (L ^* , a ^* , b ^* ) of each color pixel in the L ^* a ^* b ^* color system chromaticity diagram measured with a D65 light source was (48.6, 27.5, -71.7).

(Formation of Yellow Sub-Pixel)
The coloring composition Y was applied by spin coating onto a substrate on which red, green and blue subpixels were formed, and then dried by heating at 90°C for 10 minutes. The obtained coloring composition coating film was exposed to 200 mJ/ ^cm2 of i-line through a negative photomask in the positional relationship with the red, green and blue subpixels as shown in FIG. 5, and then developed with a 0.3 mass% aqueous solution of tetramethylammonium hydroxide at 23°C. Subsequently, a heat treatment was performed at 230°C for 30 minutes to form a yellow subpixel. The yellow subpixel was a square with a side length of 129 μm, the length of the minimum repeating unit, i.e., the distance between the centers of adjacent subpixels of the same color, was 318 μm, and the color (L ^* , a ^* , b ^* ) of each color pixel in the L ^* a ^* b ^* color system chromaticity diagram measured with a D65 light source was (94.8, -38.6, 83.3).

(Formation of color-adjusting member)
The composition H1 for forming a color-adjusting member was applied by spin coating onto a substrate on which red, green, blue and yellow subpixels were formed, and then heated and dried at 90°C for 10 minutes. The obtained coating film of the composition H1 for forming a color-adjusting member was exposed to 200 mJ/ ^cm2 of i-line through a negative photomask in the positional relationship with the red, green, blue and yellow subpixels as shown in Figure 5, and then developed with a 0.3 mass% tetramethylammonium hydroxide aqueous solution at 23°C. Subsequently, a heat treatment was performed at 230°C for 30 minutes to form a color-adjusting member having a film thickness of 2.0 μm and a width of 30 μm, and a color filter arranged as shown in Figure 5 was manufactured. The ratio H/M of the area H of the taste-adjusting member to the area M of one pixel was 0.342.

The chromaticity xy of the color-adjusting component was 0.308 and 0.306, respectively, the Y value in the CIE 1931 color system was 92.7, and the T450, T550, and T700 were 99.1, 90.2, and 99.7, respectively.

(Manufacture of display devices)
The obtained color filter was attached to an array substrate for evaluation to prepare a display device. The L ^* value during white display was 60.5, and the chroma was 9.2.

[Examples 2 to 4]
Instead of H1, H2 to H4 were prepared as compositions for forming a color-adjusting member in the amounts shown in Table 1, and were used in Examples 2 to 4. Otherwise, color filters and display devices were manufactured in the same manner as in Example 1. The evaluation results are summarized in Table 2.

[Comparative Example 1]
A color filter and a display device were manufactured in the same manner as in Example 1, except that no color-adjusting member was formed. In Examples 1 to 4, the chromaticity xy of the portions corresponding to the portions where the color-adjusting members were formed was 0.310 and 0.316, respectively, the Y value in the CIE1931 color system was 100.0, and the T450, T550, and T700 were 100.0, 100.0, and 100.0, respectively. In addition, the L ^* of the display device when displaying white was 62.7, and the chroma was 13.2.

1 Red subpixel 2 Green subpixel 3 Blue subpixel 4 Color adjusting member 5 Pixel 6 Red subpixel 7 Green subpixel 8 Blue subpixel 9 Color adjusting member 10 Pixel 11 Red subpixel 12 Green subpixel 13 Blue subpixel 14 Yellow subpixel 15 Color adjusting member 16 Pixel 17 Red subpixel 18 Green subpixel 19 Blue subpixel 20 Color adjusting member 21 Pixel 22 Red subpixel 23 Green subpixel 24 Blue subpixel 25 Yellow subpixel 26 Color adjusting member 27 Pixel

The color filter substrate of the present invention can be suitably used for electronic paper.

Claims (10)

A color filter having at least any one of red, green and blue sub-pixels on a substrate, wherein a color adjusting member having a Y value of 70 or more and 98 or less in the CIE 1931 color system is disposed between the sub-pixels , the color adjusting member contains a color material, and a content of the color material in a solid content of the color adjusting member is 0.01% by mass or more and 1% by mass or less . The color filter of claim 1 having at least red, green and blue subpixels on the substrate. 3. The color filter according to claim 1, wherein the color adjusting member has a transmittance T450 of 90% or more for light with a wavelength of 450 nm, a transmittance T550 of 65% to 98% or less for light with a wavelength of 550 nm, and a transmittance T700 of 80% or more for light with a wavelength of 700 nm. The color filter according to claim 2 , further comprising a yellow subpixel. The color filter according to claim 1 , wherein the content of the color material in the solid content of the color adjusting member is 0.05% by mass or more and 1% by mass or less. The color filter according to claim 1 , wherein the color material is a blue color material or a purple color material. A display device comprising the color filter according to any one of claims 1 to 6 . An electronic paper comprising the color filter according to any one of claims 1 to 6 . A method for displaying white on an electronic paper having the color filter and electrophoretic display layer according to any one of claims 2 to 6 , comprising making the reflectance of a portion of the electrophoretic display layer corresponding to the blue subpixel higher than the reflectance of a portion of the electrophoretic display layer corresponding to any subpixel of any other color. A composition for forming a color adjusting member capable of forming a color adjusting member between sub-pixels of a color filter having at least any one of red, green and blue sub-pixels on a substrate, the composition being characterized in that when formed into a film having a thickness of 2 μm, the Y value in the CIE 1931 color system is 70 or more and 98 or less, the composition contains a colorant, and the content of the colorant in the solid content is 0.01% by mass or more and 1% by mass or less.