JP2009276490A - Color filter and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter with high reliability having a wide range of color reproducibility and no display unevenness or the like due to elution of an ionic impurity by a color filter pigment, and to provide a liquid crystal display device. <P>SOLUTION: In the color filter for a liquid crystal display device having a RGB-LED backlight device, the display chromaticity of a green pixel is in the range of 0.240≤x≤0.300 and 0.600≤y≤0.675 in the xy chromaticity coordinates by CIE1931-XYZ colorimetric system, the elution amount of Br ion in N-methylpyrrolidone per unit area is ≤17 ng/cm<SP>2</SP>, and the green color layer has a pigment content of ≥27 mass% and ≤45 mass%. In another embodiment, in the color filter for the liquid crystal display device having the RGB-LED backlight device, the display chromaticity of a red pixel is in the range of 0.640≤x≤0.660 and 0.300≤y≤0.335 in the xy chromaticity coordinates by CIE1931-XYZ colorimetric system, the elution amount of Na ion in N-methylpyrrolidone per unit area is ≤4 ng/cm<SP>2</SP>, and the red color layer has a pigment content of ≥25 mass% and ≤30 mass%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a color filter for a liquid crystal display device and a liquid crystal display device including a backlight device that displays white by combining red, green, and blue three-color LEDs. In particular, the present invention relates to a color filter for a horizontal electric field type liquid crystal display device that is directed to a liquid crystal sandwiching surface side and is incorporated in a liquid crystal display device without an electrode between a pixel and liquid crystal, and a color filter for this horizontal electrolysis type liquid crystal display device. Color filter capable of ensuring sufficient suitability and reliability for a liquid crystal display device manufacturing process without providing a protective layer (overcoat layer) made of a transparent resin that has an effect of reducing ion elution of the colored layer, and a liquid crystal provided with the same The present invention relates to a display device.

  Color liquid crystal display devices are rapidly spreading mainly in computer terminal display devices and television image display devices. Among the members for liquid crystal display devices, the backlight device and the color filter are important components indispensable for the color display of the liquid crystal display device. In recent years, the backlight device is required to improve the color reproducibility in order to improve the image quality. The following efforts have been made in both color filters and color filters.

Conventionally, a cold cathode fluorescent lamp (CCFL) having emission wavelengths in the red, green, and blue wavelength regions has been often used as a light source of a backlight device. 2. Description of the Related Art In recent years, as disclosed in Patent Document 1 and Patent Document 2, instead of CCFL, a backlight device using a light emitting diode (LED: Light Emitting Diode) with no subpeak peak in the emission spectrum as a light source Has been developed. Backlight devices using LEDs have advantages such as better response than CCFL, lower power consumption, mercury-free and environmental friendliness, improved moving image characteristics and lower consumption of liquid crystal display devices It also has the effect of promoting electricity and recycling.

As color filters, efforts have been made to improve color reproducibility by increasing the pixel film thickness or increasing the pigment content of the coloring material. However, when the pixel film thickness is increased, there is a problem that the display quality of the liquid crystal display device is deteriorated such that the photocuring does not proceed to the deep part of the pixel, the patterning shape is deteriorated, and unevenness is likely to occur. In addition, increasing the pigment content of the color filter increases the surface area where the pigment comes into contact with the solvent, which increases the ion elution property of the pigment and causes problems such as display unevenness in the liquid crystal display device. was there. Due to the above background, it has been difficult to improve color reproducibility without degrading display quality.
Japanese Patent No. 3924473 Japanese Laid-Open Patent Publication No. 2005-321727

  The present invention has been made to solve the above-described problems, and has a color reproducibility that is wide in color reproducibility and free from display unevenness due to elution of ionic impurities by the color filter pigment, and a liquid crystal display. It is an object to provide an apparatus. In particular, even in a horizontal electric field type liquid crystal display device that is incorporated in a liquid crystal display device with a color filter facing the liquid crystal sandwiching surface side and without an electrode between the pixel and the liquid crystal, high color reproducibility and high reliability are achieved. The challenge is to achieve both.

The invention according to claim 1 of the present invention is a color filter for a liquid crystal display device including a backlight device that combines white LEDs of red, green, and blue to exhibit white color.
In the xy chromaticity coordinates in which a green pixel is used to form a colored layer constituting at least one color pixel and the display chromaticity of the green pixel is CIE1931-XYZ color system, 0.240 ≦ x ≦ 0.300, A color filter having a range of 0.600 ≦ y ≦ 0.675 and an elution amount of Br ions per unit area of the green pixel into N-methylpyrrolidone of 17 ng / cm ² or less It is.

  The color filter according to claim 1, wherein the pigment content of the colored layer forming the green pixel is 27% by mass or more and 45% by mass or less. It is.

Next, an invention according to claim 3 of the present invention is a color filter for a liquid crystal display device including a backlight device that displays white by combining LEDs of three colors of red, green, and blue. A red pixel is used to form the colored layer, and the display chromaticity of the red pixel is 0.640 ≦ x ≦ 0.660, 0.300 ≦ y ≦, in the xy chromaticity coordinates in which the display chromaticity is the CIE1931-XYZ color system. The color filter is in a range of 0.335, and an elution amount of Na ions per unit area of the red pixel into N-methylpyrrolidone is 4 ng / cm ² or less.

  According to a fourth aspect of the present invention, there is provided the color filter according to the third aspect, wherein the pigment content of the colored layer forming the red pixel is 25% by mass or more and 30% by mass or less. It is.

  According to a fifth aspect of the present invention, there is provided a liquid crystal display device comprising the color filter according to at least one of the first to fourth aspects.

  According to a sixth aspect of the present invention, there is provided a horizontal electrolysis type liquid crystal display device comprising the color filter according to at least one of the first to fourth aspects.

In the present invention, when the pigment content of the green colored layer of the color filter is 27 to 45% by mass in a liquid crystal display device including a backlight device that exhibits white by combining three LEDs of red, green, and blue, The display chromaticity of the green pixel is 0.240 ≦ x ≦ 0.300, 0.600 ≦ y ≦ 0.675, and the elution amount of Br ions per unit area of the green colored layer in N-methylpyrrolidone is It was found that it was possible to make it 17 g / cm ² or less.

Similarly, in a liquid crystal display device including a backlight device that displays white by combining three LEDs of red, green, and blue, when the pigment content of the red colored layer of the color filter is 25 to 30% by mass, red The display chromaticity of the pixel is 0.640 ≦ x ≦ 0.660, 0.300 ≦ y ≦ 0.335, and the elution amount of Na ions per unit area of the red colored layer in N-methylpyrrolidone is 4 ng It was found that it was possible to make it below / cm ² .

  Thus, by providing the color filter of the present invention, it is possible to take advantage of the characteristics of the backlight and improve the color reproducibility and chemical resistance. In addition, a liquid crystal display device and a horizontal electric field type liquid crystal display device that achieve both high color reproducibility and high reliability can be realized. In particular, in a horizontal electrolysis type liquid crystal display device, good color reproducibility and reliability can be obtained without providing a protective layer (overcoat layer) made of a transparent resin that is effective in reducing ion elution of the colored layer of the color filter. be able to.

  The color filter of the present invention will be described in detail below based on one embodiment.

  The present inventors reduced the pigment concentration of the color layer material of the color filter while maintaining the display quality by combining the backlight of the liquid crystal display device and the color filter in an optimal combination, and the chemical resistance and solvent resistance. Investigated to improve reliability by reducing ion elution amount mainly for chemicals and solvents.

  The color filter of the present invention includes a plurality of color pixels on at least a transparent substrate, and the plurality of color pixels includes at least a colored layer. A plurality of colors include a combination of red (R), green (G), and blue (B), and a combination of yellow (Y), magenta (M), and cyan (C). The color filter of the present invention is red. The present invention can be particularly preferably applied to a color filter having a colored layer and a green colored layer (that is, an RGB system).

  In the liquid crystal display device manufacturing step, there is a step of forming an alignment film for regulating the alignment of the liquid crystal on the color filter. The alignment film material is generally formed by applying, drying, and baking a solution in which polyimide or a precursor thereof is dissolved in an appropriate solvent.

  As a solvent for dissolving polyimide or a precursor thereof, N-methylpyrrolidone (N-methylpyrrolidone or 1-methyl-2-pyrrolidone: hereinafter abbreviated as NMP), γ-butyrolactone, or a mixture thereof is used as a main component. It is often done. Therefore, the color filter is required to have resistance to these solvents.

  The pigment used for the colorant of the red color layer and the green color layer in the RGB color filter has low NMP resistance, and dissolves into the NMP as ions from the color layer, causing dripping of the liquid crystal alignment, resulting in display unevenness. This phenomenon becomes particularly prominent when the pigment particle size is decreased to improve the contrast or when the pigment concentration is increased.

  Specifically, in the green colored layer, a large amount of Br ions contained in the pigment is eluted in NMP, and in the red colored layer, a large amount of Na ions remaining in the coating film tends to be eluted in NMP by the development process. It is known that the main cause of alignment failure in a liquid crystal panel is a large influence of halogen ions or alkali metal ions that are easily ionized. Therefore, in the color filter of the present invention, the amount of ion elution from the green colored layer that easily generates halogen ions and the red colored layer that easily generates alkali metal ions is reduced, and high color reproduction is achieved. We studied to obtain a reliable liquid crystal display device.

  Here, as a reference value for reducing the amount of elution, per unit area of the colored layer when using CCFL for the backlight and achieving an NTSC ratio of 72% in the xy chromaticity of the CIE1931-XYZ color system for the color filter. The amount of Na and Br elution ions into NMP was set as a reference value.

In the color filter of the present invention, the elution amount of Br ion per unit area to NMP of the green colored layer is 17 ng / cm ² or less, and the Na ion to NMP of the red colored layer is 70% or less of the reference value. The case where the amount of elution was 4 ng / cm ² or less was set as a highly reliable color filter in comparison with the prior art.

Further, in the present invention, since the objective is to achieve both high color reproducibility and high reliability, a backlight device that displays white by combining red, green, and blue three-color LEDs in the backlight is used.
A color reproduction range equivalent to 100% of the European Broadcasting Union (EBU) ratio of the European Broadcasting Standard, which is the standard standard for current television broadcasting, that is, about 72% of the NTSC (National Television System Committee) standard NTSC (National Television System Committee). Is adopted, the EBU standard hue Red (0.640, 0.330), Green (0.600, 0.300), Blue (0.150, 0.15, xy chromaticity which is the CIE1931 XYZ color system. 0.060) as the reference chromaticity, the display chromaticity of the red pixel is 0.640 ≦ x ≦ 0.660, 0.300 ≦ y ≦ 0.335, and the display chromaticity of the green pixel is 0.240 ≦ x ≦ It was set as 0.300, 0.600 ≦ y ≦ 0.675. When the display chromaticity of the red pixel is x <0.640, the display chromaticity of the current television broadcasting standard is not satisfied, and when x> 0.660, the Na ion elution amount from the red colored layer to NMP There is a problem that exceeds the reference value. The same applies to the chromaticity of the green pixel. When y <0.600, the display chromaticity of the current television broadcasting standard is not satisfied, and when y> 0.675, the Br ion elution amount from the green pixel to NMP There is a problem that exceeds the reference value.

  In order to satisfy the above chromaticity and to make the ion elution amount to NMP below the reference value, the pigment content forming the colored layer is 27% by mass or more of the pigment content of the colored layer forming the green pixel, The pigment content of the colored layer forming the red pixel must be 25% by mass or more and 30% by mass or less. When the green pigment content is less than 27% by mass, the displayed chromaticity does not satisfy the above setting and the color reproducibility is lowered. When the green pigment content exceeds 45% by mass, the green colored layer is added to NMP. The Br ion elution amount exceeds the reference value and does not become highly reliable.

  Further, when the red pigment content is less than 25% by mass, the display chromaticity does not satisfy the above setting and the color reproducibility is deteriorated. When the red pigment content exceeds 30% by mass, the red colored layer becomes NMP. Na ion elution amount exceeds the standard value and does not become highly reliable.

  Below, the method for obtaining the color filter of this invention is explained in full detail.

  A transparent substrate is used as the base material of the color filter of the present invention. The transparent substrate preferably has a certain transmittance with respect to visible light, and preferably has a transmittance of 80% or more. Generally, it may be one used in a liquid crystal display device, and examples thereof include a plastic substrate such as PET and glass, but a glass substrate is usually used. In the case of using a light shielding pattern, it is only necessary to use a known method in which a metal thin film such as chromium or a light shielding resin pattern is previously provided on the transparent substrate.

  The color filter pixel may be manufactured by any known method such as an inkjet method, a printing method, a photoresist method, or an etching method. However, in consideration of high definition, controllability and reproducibility of spectral characteristics, etc., a photoresist method (or a photolithography method: hereinafter referred to as a photolithography method) is preferable. In the photolithographic method, a colored composition in which a pigment is dispersed in a transparent resin in a suitable solvent together with a photoinitiator and a polymerizable monomer is coated on a transparent substrate to form a colored layer, and the colored layer is patterned. One color pixel is formed by exposure and development. This process is repeated for each color to produce a color filter.

  When the colored layer constituting the pixel included in the color filter of the present invention is prepared by preparing a photosensitive colored composition and using a photolithography method, for example, the following method is followed. A pigment serving as a colorant is dispersed in a suitable solvent together with a photoinitiator and a polymerizable monomer in a transparent resin. There are various methods such as mill base, three rolls, jet mill and the like, and there are no particular limitations.

  Specific examples of organic pigments that can be used in the colored composition forming the colored layer of the color filter of the present invention are shown by color index numbers.

  Red coloring compositions for forming red filter segments (pixels) include C.I. I. Pigment Red 254, 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 255, Red pigments such as H.264, 272, and 279 can be used. A yellow pigment and an orange pigment can be used in combination with the red coloring composition.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 144, 146, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 1 73, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, 213, 214 and the like.

  Examples of orange pigments include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.

  Examples of the green coloring composition for forming the green filter segment include C.I. I. Green pigments such as Pigment Green 7, 10, 36, and 37 can be used. The green coloring composition can be used in combination with the same yellow pigment as the red coloring composition.

  Examples of the blue coloring composition for forming the blue filter segment include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 80, etc., preferably C.I. I. Pigment Blue 15: 6 can be used. In addition, C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like, preferably C.I. I. Pigment Violet 23 can be used in combination.

  In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red bean (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

  The transparent resin used for the coloring composition is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin. If necessary, the transparent resin can be used alone or in admixture of two or more monomers or oligomers that are precursors thereof that are cured by irradiation with radiation to produce a transparent resin.

Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. , Acrylic resins, alkyd resins, polystyrene, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like. 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 phenol resins.

  Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Examples of polymerizable monomers that can be used as a photocrosslinking agent include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and ethylene oxide-modified trimethylolpropane tri (meth). Representative examples include various acrylic esters and methacrylic esters such as acrylate and propylene oxide-modified trimethylolpropane tri (meth) acrylate. These can be used alone or in admixture of two or more. Further, for the purpose of keeping the photo-curing property properly, other polymerizable monomers and oligomers can be mixed and used as necessary.

  Other polymerizable monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (Meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate , Pentaerythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate Rate, neopentyl glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, (meth) acrylic ester of methylolated melamine, epoxy (meth) Various acrylates and methacrylates such as acrylate and urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide, N-hydroxymethyl ( Examples include meth) acrylamide, N-vinylformamide, acrylonitrile and the like. Also about these, it can use individually or in mixture of 2 or more types.

  When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the coloring composition. Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Benzoin compounds such as dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4 ' Benzophenone-based compounds such as methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4- Thioxanthone compounds such as diisopropylthioxanthone and 2,4-diethylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p- Methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis ( Trichloromethyl) -s-triazine, 2,4-bis (trichloro) Methyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′- Oxime ester compounds such as methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-tri Phosphine compounds such as tilbenzoyldiphenylphosphine oxide, quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like are used. . These photopolymerization initiators can be used alone or in combination. The amount of the photopolymerization initiator used is preferably 0.5 to 50% by mass, more preferably 3 to 30% by mass, based on the total solid content of the colored composition.

  Further, as sensitizers, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-Ethylhexyl 4-dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethyl) Amine-based compounds such as amino) benzophenone can also be used in combination. These sensitizers can be used alone or in combination. The amount of the sensitizer used is preferably 0.5 to 60% by mass, more preferably 3 to 40% by mass based on the total amount of the photopolymerization initiator and the sensitizer.

  Furthermore, the coloring composition can contain a polyfunctional thiol that functions as a chain transfer agent. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination. The amount of the polyfunctional thiol used is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, based on the total solid content of the colored composition. If it is less than 0.1% by mass, the effect of adding a polyfunctional thiol is insufficient, and if it exceeds 30% by mass, the sensitivity is too high and the resolution is lowered.

  Examples of the thermal crosslinking agent include melamine resin and epoxy resin. Examples of the melamine resin include alkylated melamine resins (methylated melamine resin, butylated melamine resin, etc.), mixed etherified melamine resins, and the like, which may be a high condensation type or a low condensation type. Any of these may be used alone or in admixture of two or more. Moreover, an epoxy resin can also be mixed and used as needed. Examples of the epoxy resin include glycerol / polyglycidyl ether, trimethylolpropane / polyglycidyl ether, resorcin / diglycidyl ether, neopentyl glycol / diglycidyl ether, 1,6-hexanediol / diglycidyl ether, ethylene glycol (polyethylene). Glycol) and diglycidyl ether. Also about these, it can use individually or in mixture of 2 or more types.

  The coloring composition can contain an organic solvent as necessary. Examples of the organic solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These may be used alone or in combination.

  On the transparent substrate, the above-mentioned photosensitive coloring composition is applied and prebaked. As a means for applying, spin coating, dip coating, die coating, etc. are usually used, but it is not limited to these as long as it can be applied on the substrate with a uniform film thickness. Prebaking is preferably performed at 50 to 120 ° C. for about 10 to 20 minutes. The coating film thickness is arbitrary, but considering the spectral transmittance and the like, the film thickness after pre-baking is usually about 2 μm. The substrate on which the photosensitive coloring composition is applied to form a colored layer is exposed through a pattern mask. A normal high-pressure mercury lamp or the like may be used as the light source.

  Subsequently, development is performed. An alkaline aqueous solution is used as the developer. Examples of the alkaline aqueous solution include a sodium carbonate aqueous solution, a sodium hydrogen carbonate aqueous solution, a mixed aqueous solution of the two, or a mixture obtained by adding an appropriate surfactant to them. After development, it is washed with water and dried to obtain a pixel of any one color.

  By repeating the above-described series of steps by changing the photosensitive coloring composition and pattern as many times as necessary, it is possible to obtain a colored pattern in which a necessary number of colors are combined, that is, a pixel of a plurality of colors.

[Backlight device]
Hereinafter, a method for obtaining the backlight used in the present invention will be described. The backlight device used in the present invention refers to a planar light source device that is disposed on the back surface of a liquid crystal panel and is used as a back light source means of a transmissive or transflective color liquid crystal display device. LED of three colors that emit light in the wavelength range of the light source, and light uniformizing means for converting the light source light into a substantially uniform surface light source.

The backlight device includes an LED light source, a reflector that reflects light emitted from the light source toward the viewer, and a light-transmitting flat plate that is used as a light guide for guiding light from the light source into a planar shape. It is configured by appropriately arranging a substrate, a light control sheet on which a triangular prism array is formed, and the like. As a light source installation method, a light source is disposed directly under the back surface of the liquid crystal element (directly under method), or a light source is disposed on the side surface and a light-transmitting light guide such as an acrylic plate is used to direct light into a planar shape. A typical method is a method (side light method) in which a surface light source is obtained by converting into a light source. For applications that require high luminance, the direct method is suitable, and for applications that require a reduction in thickness, the sidelight method is suitable.

  An LED light source generally has emission peaks in the red, green, and blue wavelength regions. Examples of LEDs having a main emission wavelength in the red region include GaAsP-based LEDs, LEDs having a main emission wavelength in the green region include GaP-based LEDs, and LEDs having a main emission wavelength in the blue region include InGaN-based LEDs. And GaN-based LEDs.

  Specific examples of the present invention and comparative examples will be described below. In addition, this invention is not limited to a following example, unless it deviates from the meaning.

[Preparation of photosensitive coloring composition]
The following were used for the coloring agent for coloring the coloring composition used for color filter preparation. Red, green and blue colored compositions were prepared using the respective pigments.

Red pigment: C.I. I. Pigment Red 254 (“Ilgar Forred B-CF” manufactured by Ciba Specialty Chemicals), C.I. I. Pigment Red 177 (“Chromoval Red A2B” manufactured by Ciba Specialty Chemicals), and C.I. I. Pigment Yellow 150 ("Fanchon First Yellow Y-5688" manufactured by LANXESS)
Green pigment: C.I. I. Pigment Green 36 (“Rionol Green 6YK” manufactured by Toyo Ink Co., Ltd.), C.I. I. Pigment Yellow 150 ("Funcheon First Yellow Y-5688" manufactured by LANXESS), and C.I. I. Pigment Yellow 138 ("Ariotor Yellow K0961HD" manufactured by BASF)
Blue pigment: C.I. I. Pigment Blue 15 (“Rionol Blue ES” manufactured by Toyo Ink Co., Ltd.), C.I. I. Pigment Violet 23 (manufactured by BASF “Paliogen Violet 5890”)
[Preparation of Binder Resin Component (Synthesis Example 1)]
The reaction vessel was charged with 800 parts by mass of cyclohexanone, heated to 100 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out the polymerization reaction. .
-Benzyl methacrylate 60.0 parts by mass-Methacrylic acid 30.0 parts by mass-Methyl methacrylate 80.0 parts by mass-Butyl methacrylate 80.0 parts by mass-Azobisisobutyronitrile 10.0 parts by mass After dropping, the temperature is further 100 ° C. After reacting for 3 hours, 2.0 parts by mass of azobisisobutyronitrile dissolved in 50 parts by mass of cyclohexanone was added, and the reaction was further continued at 100 ° C. for 1 hour to obtain an acrylic resin solution. The weight average molecular weight of the acrylic resin was about 40,000.
After cooling to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20% by mass. An acrylic resin solution was prepared.

[Red photosensitive coloring composition 1]
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a red pigment dispersion.
-Red pigment: C.I. I. Pigment Red 254 10 parts by mass Red pigment: C.I. I. Pigment Red 177 10 parts by mass Yellow pigment: C.I. I. Pigment Yellow 150 5 parts by mass Binder resin prepared in Synthesis Example 1 270 parts by mass Thereafter, a mixture having the following composition was stirred and mixed to be uniform, and then filtered through a 5 μm filter to obtain a red colored composition 1 .
-28.6 parts by mass of the dispersion of the red pigment-19.0 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 48.5 parts by mass [Red photosensitive coloring composition 2]
-32.0 parts by mass of the above red pigment dispersion-17.9 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 46.2 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a red photosensitive coloring composition 2.

[Red photosensitive coloring composition 3]
-34.0 parts by mass of the dispersion of the red pigment-17.2 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 44.6 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a red photosensitive coloring composition 3.

[Red photosensitive coloring composition 4]
-38.8 parts by mass of the above red pigment dispersion-15.8 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
Cyclohexanone 41.5 parts by mass The above mixture was stirred and mixed so as to be uniform, and then filtered through a 5 µm filter to obtain a red photosensitive coloring composition 4.

[Red photosensitive coloring composition 5]
-36.5 parts by mass of the dispersion of the above red pigment-16.5 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 43.1 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a red photosensitive coloring composition 5.

[Red photosensitive coloring composition 6]
-23.5 parts by mass of the dispersion of the red pigment-19.6 parts by mass of the binder resin prepared in Synthesis Example 1-3.0 parts by mass of caprolactone-modified dipentaerythritol hexaacrylate ("Kayarad DPCA30" manufactured by Nippon Kayaku Co., Ltd.)
-Photoinitiator 0.1 mass part ("Irgacure OXE-02" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.6 parts by mass (“Irgacure 379” manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 49.73 mass parts The said mixture was stirred and mixed so that it might become uniform, Then, it filtered with a 5-micrometer filter, and the red photosensitive coloring composition 6 was obtained.

[Green photosensitive coloring composition 1]
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a green pigment dispersion.
Green pigment: C.I. I. Pigment Green 36 16 parts by mass Yellow pigment: C.I. I. Pigment Yellow 150 16 parts by mass Binder resin prepared in Synthesis Example 1 190 parts by mass Thereafter, a mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain green photosensitive coloring composition 1 Obtained.
-27.5 parts by mass of the green pigment dispersion-11.1 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
・ Cyclohexanone 58.3 parts by mass
[Green photosensitive coloring composition 2]
-35.4 parts by mass of the green pigment dispersion-8.3 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
-Cyclohexanone 53.2 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a green photosensitive coloring composition 2.

[Green photosensitive coloring composition 3]
-45.5 parts by mass of the green pigment dispersion-4.7 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
Cyclohexanone 46.6 parts by mass The above mixture was stirred and mixed so as to be uniform, and then filtered through a 5 µm filter to obtain a green photosensitive coloring composition 3.

[Green photosensitive coloring composition 4]
-50.0 parts by mass of the green pigment dispersion-3.1 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
-Cyclohexanone 43.7 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a green photosensitive coloring composition 4.

[Green photosensitive coloring composition 5]
-46.5 parts by mass of the green pigment dispersion-4.4 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
Cyclohexanone 46.0 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a green photosensitive coloring composition 5.

[Green photosensitive coloring composition 6]
-26.3 parts by mass of the green pigment dispersion-11.5 parts by mass of the binder resin prepared in Synthesis Example 1-1.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
・ Photoinitiator 0.1 parts by mass (“Irgacure OXE02” manufactured by Ciba Specialty Chemicals)
・ 1.4 parts by weight of photoinitiator ("Lucirin TPO" manufactured by BASF)
-Cyclohexanone 59.0 parts by mass The above mixture was stirred and mixed so as to be uniform, and then filtered through a 5 µm filter to obtain a green photosensitive coloring composition 6.

[Blue photosensitive coloring composition 1]
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a blue pigment dispersion.
Blue pigment: C.I. I. Pigment Blue 15 32 parts by mass Purple pigment: C.I. I. 3 parts by weight of Pigment Violet 23 173 parts by weight of the binder resin prepared in Synthesis Example 1 Then, the mixture having the following composition was stirred and mixed to be uniform, and then filtered through a 5 μm filter to obtain the blue photosensitive coloring composition 1 Obtained.
-33.7 parts by mass of the blue pigment dispersion-6.8 parts by mass of the binder resin prepared in Synthesis Example 1-4.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
-Photoinitiator 1.4 parts by mass ("Irgacure 379" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
・ Cyclohexanone 53.2 parts by mass
[Blue photosensitive coloring composition 2]
-27.1 parts by mass of the above blue pigment dispersion-9.0 parts by mass of the binder resin prepared in Synthesis Example 1-4.7 parts by mass of dipentaerythritol hexaacrylate ("Aronix M402" manufactured by Toagosei Co., Ltd.)
-Photoinitiator 1.4 parts by mass ("Irgacure 379" manufactured by Ciba Specialty Chemicals)
・ Photoinitiator 0.2 parts by mass (“Kayacure DETX” manufactured by Nippon Kayaku Co., Ltd.)
-Cyclohexanone 57.6 parts by mass The above mixture was stirred and mixed to be uniform, and then filtered through a 5 µm filter to obtain a blue photosensitive coloring composition 2.

[Production of color filter]
A color filter was produced using the obtained colored composition. The red coloring composition was applied on a glass substrate by spin coating so as to have a film thickness of 2 μm. After drying, striped pattern exposure was performed with an exposure machine, and development was performed with an alkaline developer for 90 seconds to obtain a colored layer of striped red pixels. The alkaline developer has the following composition.
・ Sodium carbonate 1.5% by mass
・ Sodium bicarbonate 0.5% by mass
・ Anionic surfactant 8.0% by mass
("Peralex NBL" manufactured by Kao Corporation)
・ 90% by mass of water
Next, the green coloring composition was similarly applied by spin coating so that the film thickness was 2 μm. After drying, the striped colored layer is exposed and developed at a position shifted from the above-mentioned red pixel colored layer by an exposure machine, thereby obtaining a green pixel colored layer adjacent to the red pixel colored layer. It was.

  Further, in the same manner as for red and green, a blue coloring composition having a film thickness of 2 μm and a blue pixel coloring layer adjacent to the red and green pixel coloring layers was obtained. Thus, a color filter having a striped colored layer of three colors of red, green and blue on the transparent substrate was obtained.

  By the method described above, the combination of the red, green, and blue coloring compositions was appropriately changed to produce a color filter.

[Backlight]
A CCFL (cold cathode fluorescent tube) backlight having an emission spectrum shown in FIG. 1 was used. In addition, as an RGB-LED backlight that exhibits white using three-color LEDs of red, green, and blue, a backlight that exhibits an emission spectrum shown in FIG. 2 was used.

<Example 1>
An RGB-LED was used for the backlight, and the color filter was formed using a red photosensitive coloring composition 1, a green photosensitive coloring composition 1, and a blue photosensitive coloring composition 1 to form a colored layer. Example 1 It was.

<Example 2>
An RGB-LED was used for the backlight, and a color layer was formed using the red photosensitive coloring composition 2, the green photosensitive coloring composition 2, and the blue photosensitive coloring composition 1 for the color filter. Example 2 It was.

<Example 3>
An RGB-LED was used for the backlight, and a color layer was formed using the red photosensitive coloring composition 3, the green photosensitive coloring composition 3, and the blue photosensitive coloring composition 1 for the color filter. Example 3 It was.

<Comparative Example 1>
Comparative Example 1 was obtained by using CCFL as the backlight and using a color layer formed of red photosensitive coloring composition 4, green photosensitive coloring composition 4, and blue photosensitive coloring composition 2 as the color filter. .

<Comparative Example 2>
Comparative Example 2 using RGB-LED as a backlight and a color filter using a red photosensitive coloring composition 5, a green photosensitive coloring composition 5, and a blue photosensitive coloring composition 1 as a color filter. It was.

<Comparative Example 3>
Comparative Example 3 using RGB-LED as a backlight and a color filter using a red photosensitive coloring composition 1, a green photosensitive coloring composition 6, and a blue photosensitive coloring composition 1 as a color filter. It was.

<Comparative example 4>
Comparative Example 4 using RGB-LED as a backlight and a color filter using a red photosensitive coloring composition 6, a green photosensitive coloring composition 1, and a blue photosensitive coloring composition 1 as color filters. It was.

[Evaluation]
The following evaluation was performed about the red and green photosensitive coloring composition produced in Examples 1-3 and Comparative Examples 1-4.

[Chromaticity / Pigment concentration]
Each chromaticity measurement result combining the produced color filter and backlight, the concentration of the red pigment in the red colored layer with respect to the solid content, the concentration of the green pigment in the green colored layer with respect to the solid content, and the NTSC ratio Compared.

[NMP elution evaluation]
The red and green photosensitive coloring compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were applied onto a glass substrate having a thickness of 200 mm × 200 mm and a thickness of 1.1 mm, respectively, using a spin coater to prepare a coated substrate. . Next, it was dried at 70 ° C. for 20 minutes. Then, it exposed with the exposure machine, developed for 40 second using 2 mass% potassium hydroxide aqueous solution as an alkali developing solution, and baked at 230 degreeC for 20 minutes.

  The substrate that has undergone the above steps is heated on a hot plate at 50 ° C., and 500 μL of NMP is dropped onto the surface of the colored layer of each pixel and eluted for 15 minutes, and then the dropped NMP is recovered with 9 times the amount of water, The NMP eluate was prepared by diluting 2-fold with ethanol.

The NMP eluate obtained in such a process is measured with an ion chromatograph DX-500 (manufactured by DIONEX), the amount of eluted ions is measured, and the ion elution per unit area is determined by the diluted concentration and elution area of NMP. The amount was calculated.
A case where the Na ion elution amount per unit area of the red colored layer to NMP is 4 ng / cm ² or less. When it was more than that, it was set as x.
The case where the Br ion elution amount per unit area of the green colored layer to NMP is 17 ng / cm ² or less. When it was more than that, it was set as x.

  The results of the above evaluation are shown in Table 1 below.

＜評価結果＞
表１に示した評価の結果より、バックライトに赤色、緑色及び青色の３色ＬＥＤを用いて白色を呈するバックライトを用い、カラーフィルタの赤色顔料濃度を２５質量％以上３０
質量％以下とした場合に基準色度を満たし、且つＮＭＰへのＮａイオン溶出量も４ｎｇ／ｃｍ²以下となり、緑色顔料濃度を２７質量％以上４５質量％以下である場合には基準色度を満たし、且つＮＭＰへのＢｒイオン溶出量も１７ｎｇ／ｃｍ²以下となり、高色再現且つ高信頼性が実現された。（実施例１〜３）
バックライトがＣＣＦＬである場合には、ＲＧＢ−ＬＥＤと同色相を実現するために顔料濃度を高くしなければならず、イオン溶出量も基準値以上になった（比較例１）。

<Evaluation results>
From the results of the evaluation shown in Table 1, using a backlight that uses white, red, green, and blue LEDs as the backlight, a white color is used, and the red pigment concentration of the color filter is 25% by mass or more and 30%.
The reference chromaticity is satisfied when it is less than mass%, the Na ion elution amount to NMP is 4 ng / cm ² or less, and when the green pigment concentration is 27 mass% or more and 45 mass% or less, the reference chromaticity is The amount of Br ion elution into NMP was 17 ng / cm ² or less, and high color reproduction and high reliability were realized. (Examples 1-3)
When the backlight was CCFL, the pigment concentration had to be increased in order to achieve the same hue as that of the RGB-LED, and the ion elution amount also exceeded the reference value (Comparative Example 1).

  On the other hand, when RGB-LED is used for the backlight, the pigment density is low and high chromaticity can be realized, so that high color reproduction and high reliability can be realized.

  However, when the pigment concentration is 30% by mass or more in red or 45% by mass or more in green, the color reproducibility is improved, but the ion elution amount becomes large and high reliability cannot be satisfied. (Comparative Example 2).

  In addition, when the pigment concentration is 25% by mass or less for red or 27% by mass or less for green, the ion elution amount is reduced, but the chromaticity does not satisfy the standard and the color reproducibility becomes narrow and high color. It was found that it was not reproduced (Comparative Example 4 and Comparative Example 3).

The emission spectrum of CCFL (cold cathode fluorescent tube) used for the backlight in the comparative example of this invention. The emission spectrum of RGB-LED used for the backlight in the Example and comparative example of this invention.

Claims (6)

In a color filter for a liquid crystal display device including a backlight device that combines white LEDs of red, green, and blue with a white color,
In the xy chromaticity coordinates in which a green pixel is used to form a colored layer constituting at least one color pixel and the display chromaticity of the green pixel is CIE1931-XYZ color system, 0.240 ≦ x ≦ 0.300, A color filter having a range of 0.600 ≦ y ≦ 0.675 and an elution amount of Br ions per unit area of the green pixel into N-methylpyrrolidone of 17 ng / cm ² or less .   The color filter according to claim 1, wherein the pigment content of the colored layer forming the green pixel is 27 mass% or more and 45 mass% or less. In a color filter for a liquid crystal display device including a backlight device that combines white LEDs of red, green, and blue with a white color,
In the xy chromaticity coordinates in which a red pixel is used for forming a colored layer constituting at least one color pixel and the display chromaticity of the red pixel is a CIE1931-XYZ color system, 0.640 ≦ x ≦ 0.660, A color filter having a range of 0.300 ≦ y ≦ 0.335 and an elution amount of Na ions per unit area of the red pixel into N-methylpyrrolidone is 4 ng / cm ² or less. .   The color filter according to claim 3, wherein the pigment content of the colored layer forming the red pixel is 25% by mass or more and 30% by mass or less.   A liquid crystal display device comprising the color filter according to claim 1.   A horizontal electrolysis type liquid crystal display device comprising the color filter according to claim 1.

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