JP2010175599A - Color filter and liquid crystal display device including same - Google Patents

Abstract

Provided are a color filter and a liquid crystal display device for realizing a liquid crystal display device capable of reducing the reflectance and ensuring contrast and visibility in an environment where reflection is large.
Between A transparent substrate 1 and the resin black matrix layer 2, the refractive index of the transparent substrate when the n _0, refractive index n ₂ satisfying the equation (1), the thickness d ₂ transparent resin A color filter having a layer 3. N = 4 in the formula (1). The refractive index of the resin black matrix layer is taken as n _1, the refractive index n ₂ of the transparent resin layer satisfies the formula (2) above. The refractive index n ₂ of the transparent resin layer satisfies the above formula (3). A liquid crystal display device comprising the color filter.
[Selection] Figure 2

Description

  The present invention relates to a color filter for a liquid crystal display device, and more particularly, to a color filter that realizes a liquid crystal display device that can ensure good contrast and visibility even in an environment where reflection by outside light increases outdoors. .

  Color liquid crystal display devices are rapidly spreading mainly in computer terminal display devices, television image display devices, mobile phones, portable information devices, etc., and are particularly suitable for mobile phones, portable information devices, etc. due to the advantage of being thin and light. It is used.

  An environment in which a television image can be received also in a mobile phone, a portable information device, and the like is being prepared, and accordingly, a demand for improving display characteristics is increasing. Specifically, there is an improvement in contrast and an improvement in the color gamut, but the strong demand is for the improvement in contrast. The contrast of the liquid crystal display device is greatly influenced by the contrast of the color filter, and its value is influenced. Therefore, the demand for improving the contrast of the color filter is very strong. The contrast of the color filter is mainly determined by the organic pigment contained in the colored layer, and the contrast is improved as the particle diameter of the pigment is made finer. Therefore, various developments have been made for this purpose.

  However, since mobile phones, portable information devices, etc. are used in an environment where reflection by outside light is large, such as outdoors, it has been found that sufficient contrast characteristics cannot be obtained simply by improving the contrast of the colored layer. . Specifically, the contrast is lowered by reflecting external light at the interface between the black matrix layer of the color filter and the transparent substrate.

  Conventionally, an inorganic light shielding film such as a chromium oxide / metal chromium laminated film has been mainly used for the black matrix layer (see, for example, Patent Documents 1 to 5). However, in recent years, since the so-called resin black matrix layer in which a black pigment is dispersed in a resin has become mainstream, the above-described reduction in contrast due to reflection of external light has been reduced. However, recent demands for improving contrast have not been met.

The reflected light at the interface between the resin black matrix layer and the transparent substrate is due to the fact that the refractive index of the resin black matrix layer is significantly larger than that of the transparent substrate. Need to be reduced.
However, since the refractive index of the resin black matrix layer depends on the amount of the black pigment contained, it is extremely difficult to reduce the refractive index and reduce the reflectance while maintaining a predetermined optical density.
Japanese Patent No. 3367173 Japanese Patent No. 4066467 JP-A-8-334753 Japanese Patent No. 3853591 JP 2007-171502 A

  The present invention has been made to solve the above problems, and in particular, a liquid crystal display device capable of reducing the reflectivity and ensuring good contrast and visibility even in an environment where reflection by outside light is large, such as outdoors. It is an object of the present invention to provide a color filter that realizes the above. It is another object of the present invention to provide a liquid crystal display device including the same.

The present invention provides a color filter having at least a resin black matrix layer and a colored layer formed on a transparent substrate, and when the refractive index of the transparent substrate is n ₀ between the transparent substrate and the resin black matrix layer, A color filter having a transparent resin layer having a refractive index n ₂ and a film thickness d ₂ satisfying the formula (1).

  The present invention also provides the color filter according to the above invention, wherein N = 4 in the formula (1).

In the color filter according to the present invention, when the refractive index of the transparent substrate is n ₀ and the refractive index of the resin black matrix layer is n ₁ , the refractive index n ₂ of the transparent resin layer is expressed by the following formula: It is a color filter characterized by satisfying (2).

The present invention also provides the color filter according to the invention, wherein the refractive index n ₂ of the transparent resin layer satisfies the following mathematical formula (3).

  Moreover, this invention is a liquid crystal display device provided with the color filter as described in any one of Claims 1-4.

  The present invention is the liquid crystal display device, wherein the liquid crystal display device is a transflective liquid crystal display device.

  The present invention is the liquid crystal display device, wherein the liquid crystal display device is a reflective liquid crystal display device.

The present invention provides a color filter having at least a resin black matrix layer and a colored layer formed on a transparent substrate, wherein the refractive index of the transparent substrate is n ₀ between the transparent substrate and the resin black matrix layer. Since the color filter has a transparent resin layer with a refractive index n ₂ and a film thickness d ₂ that satisfies the formula (1), the reflectance is reduced to provide good contrast and visibility even in an environment where reflection by outside light is large, such as outdoors. It is possible to realize a liquid crystal display device capable of securing the property.
In particular, the effect exhibited in a reflective liquid crystal display device that uses external light as a light source and a transflective liquid crystal display device is significant.

Below, the color filter by this invention is demonstrated in detail based on the embodiment. FIG. 1 is a cross-sectional view schematically showing an example of a conventional color filter. As shown in FIG. 1, the color filter has a resin black matrix layer and a colored layer on at least one surface of the transparent substrate. The color filter is used by being incorporated in a liquid crystal display device with one side facing the liquid crystal sandwiching side and the other side facing the side. That is, the viewer views the black matrix layer and the colored layer from the transparent substrate (other surface) side.

  Usually, the transparent substrate 1 has a refractive index of about 1.5 and the resin black matrix layer 2 has a refractive index of about 1.85. Therefore, as shown in FIG. And about 10% at the interface between the resin and the black matrix layer 2, causing a decrease in contrast.

The present inventors have found that the reflection of external light 4 can be reduced by providing an appropriate transparent resin layer 3 between the transparent substrate 1 and the resin black matrix layer 2.
A schematic structure of an example of the color filter of the present invention is shown in FIG.

As shown in FIG. 2, the transparent substrate 1 (refractive index n ₀₎ and the resin black matrix layer 2 (refractive index n ₁₎ the transparent resin layer 3 between the (refractive index n _2, the thickness d ₂₎ provided However, when external light 4 (wavelength λ) is incident, the reflected light 1 (Re-1) at the interface between the transparent substrate 1 and the transparent resin layer 3, the phase of the transparent resin layer 3, and the resin black matrix layer 2. When the phase shift of the reflected light 2 (Re-2) is an odd multiple of 1/2 of the wavelength (λ / n ₀ ) in the transparent substrate, the reflected light 1 (Re-1) and the reflected light 2 (Re-2) cancels and reflected light can be reduced.
When the refractive index n ₂ of the transparent resin layer 3 is set to satisfy n ₀ ≦ n ₂ ≦ n ₁ , the phases of the reflected light 1 (Re-1) and the reflected light 2 (Re-2) are both inverted. The phase shift between the reflected light 1 (Re-1) and the reflected light 2 (Re-2) depends only on the optical path (2 × n ₂ × d ₂ ). Therefore, it is possible wavelength of the external light 4 lambda, the refractive index n ₀ of the transparent substrate, the refractive index n ₂ of the transparent resin layer, the thickness d ₂ is to reduce the light reflection when satisfying Equation (4) below.

In order to improve the contrast, it is effective to reduce the reflected light having a high visibility of around 550 nm, specifically, 500 to 600 nm. The following formula (1) can be derived by setting λ in the formula (4) to 500 ≦ λ ≦ 600. When the relationship between n ₀ , n ₂ , and d ₂ deviates from Equation (1), the wavelength for reducing the reflected light deviates from 500 to 600 nm, and the effect of improving the contrast is reduced.

  In the above formula (1), when N satisfies a relationship other than 1, reflected light of a plurality of wavelengths can be reduced. Specifically, when N is 4, reflected light in the vicinity of 360 to 430 nm and in the vicinity of 640 to 770 nm can be reduced in addition to the vicinity of 500 to 600 nm, which is particularly advantageous.

Further, the ratio of the intensity of the reflected light Re-1 at the interface between the transparent substrate and the transparent resin layer and the intensity of the reflected light Re-2 at the interface between the transparent resin layer and the resin black matrix layer is almost twice as much as each other. Desirably not. Furthermore, it is particularly preferable that they are approximately the same. This is because a reduction effect due to interference is more effectively obtained when the intensities coincide with each other. Reflectance at the interfaces R1, R2, the refractive index n ₀ of the transparent substrate, the refractive index n ₁ of the resin black matrix layer, with a refractive index n ₂ of the transparent resin layer as in the following equation (5) Can be represented.

Therefore, n ₂ preferably satisfies the following formula (2), and more preferably satisfies formula (3). If it deviates significantly from this relationship, the intensity of the reflected light 1 (Re-1) and the reflected light 2 (Re-2) will be significantly different, and an effective reflected light reduction effect cannot be obtained.

  Hereinafter, a method for obtaining the color filter of the present invention will be described. The color filter of the present invention comprises at least a resin black matrix layer on a transparent substrate, a colored layer, and a transparent resin layer between the transparent substrate and the resin black matrix layer. Is forming. Examples of the plurality of colors include a combination of red, green, and blue (RGB) and a combination of yellow, magenta, and cyan (YMC).

  The transparent substrate used in the method of the present invention preferably has a transmittance of 80% or more with respect to visible light, and examples thereof include glass substrates generally used for liquid crystal display devices and plastic substrates such as PET. Usually, a glass substrate is used.

  The resin black matrix layer of the present invention is not particularly limited in composition and formation method as long as the desired light-shielding property, that is, optical density can be achieved. However, at least a photopolymerization initiator and a polymerizable monomer are added to a dispersion in which a black pigment such as a carbon black pigment is dispersed in a resin from the viewpoint of easy formation and relatively preferable uniformity. The photosensitive black resin composition obtained by addition is generally formed by a so-called photoresist method in which an appropriate method is applied to a transparent substrate, pattern exposure, development, and baking. In addition, a printing method, an etching method, or the like can be used.

Examples of the pigment that can be used in the black composition include a carbon black pigment, a titanium carbon black pigment, and the like, and if necessary, a red pigment, a green pigment, and a blue pigment may be mixed and used.
The resin used for the black composition includes a thermoplastic resin, a thermosetting resin, and a photosensitive 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. In addition, linear polymers containing acid anhydrides such as styrene-maleic anhydride copolymer and α-olefin-maleic anhydride copolymer can be obtained from (meth) acrylic compounds having hydroxyl groups such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

A polymerizable monomer or oligomer is used as the photocrosslinking agent. Polymerizable monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (meta ) 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, penta Erythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neope N-glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, methylolated melamine (meth) acrylate, epoxy (meth) acrylate, Various acrylic esters and methacrylic esters such as caprolactone-modified dipentaerythritol hexaacrylate and urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide N-hydroxymethyl (meth) acrylamide, N-vinylformamide, acrylonitrile and the like. These can be used alone or in admixture of two or more.

  The amount added is preferably as long as it does not impair applicability and development suitability, and is about 20% to 80% by weight, more preferably about 50% to 70% by weight, based on the total solid content of the black composition. is there. If the addition amount is less than this range, the cross-linkability is insufficient and the liquid crystal resistance is deteriorated. If the addition amount is more than this range, unevenness and pinholes are likely to occur when the black composition is applied, and the applicability is significantly deteriorated, or development The liquid solubility is remarkably lowered and the development suitability is poor.

  When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the black composition.

  As photopolymerization initiators, 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'-methyldiphenyl sulfide, 3 Benzophenone compounds such as 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4- Thioxanthone compounds such as 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 (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine compounds such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], Oxime ester compounds such as O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine compounds such as phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquino Quinone compounds such as borate compounds, carbazole compounds, imidazole compounds, titanocene compounds and the like. These photopolymerization initiators can be used alone or in combination.

  The amount of the photopolymerization initiator used is preferably 0.5 to 50% by weight, more preferably 3 to 30% by weight, based on the total solid content of the black composition.

  The amount of the sensitizer used is preferably 0.5 to 60% by weight, more preferably 3 to 40% by weight based on the total amount of the photopolymerization initiator and the sensitizer.

  Furthermore, the black 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, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-to Azine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.

  The amount of polyfunctional thiol used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the black composition. If the amount is less than 0.1% by mass, the effect of adding a polyfunctional thiol is insufficient.

  Moreover, a thermal crosslinking agent can also be added as needed. 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 black 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, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone , Petroleum solvents and the like, and these may be used alone or in combination.

  The above-mentioned photosensitive black composition is applied on a transparent substrate and prebaked. Spin coating, dip coating, die coating and the like are usually used as the means for coating, but the coating means is not limited to these as long as it can be coated with a uniform film thickness on a substrate of about 40 to 60 cm square. Prebaking is preferably performed at 50 to 120 ° C. for about 1 to 20 minutes. The coating film thickness is arbitrary and is usually about 1 to 2 μm after pre-baking. A photosensitive black composition is applied and 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 the development, washing and baking are performed to obtain a patterned resin black matrix layer.

  The transparent resin layer of the present invention is not particularly limited in composition and formation method as long as it satisfies the above-described refractive index and film thickness conditions. However, considering that the refractive index is generally required to be about 1.6 to 1.7 and heat resistance for use in the color filter, for example, a general polyimide is suitable as the alignment film material.

  For example, in the case of using polyimide, a polyamic acid that is a precursor of polyimide as in the case of the alignment film material, or a solution of a solubilized polyimide is applied on a transparent substrate by a screen printing method, a spin coating method, a die coating method, It can obtain by baking at about 220-240 degreeC after drying.

  The transparent resin layer may be uniformly formed on the entire surface of the transparent substrate 1 as shown in FIG. 2, and if necessary, the colored layer 5 may be partially formed as shown in FIG. It may be formed only in the resin black matrix layer portion by removing by a method.

  As a method for forming the colored layer 5 to be a pixel, any method such as a known inkjet method, printing method, photoresist method, etching method, or the like may be used. However, considering high definition, controllability and reproducibility of spectral characteristics, etc., a colored composition in which a pigment is dispersed in a transparent resin together with a photoinitiator and a polymerizable monomer in a suitable solvent is formed on a transparent substrate. A photoresist method is preferred in which a step of forming a single color pixel by coating and forming, pattern exposure and development is repeated for each color to produce a color filter.

  When the colored layer of the color filter of the present invention is formed by preparing a photosensitive coloring composition and using a photolithography method, for example, the following method is used. 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 indicated by color index numbers.

  Examples of the red coloring composition for forming the red coloring layer include C.I. I. Pigment Red 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, 254, 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 the orange pigment 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 coloring layer include C.I. I. Green pigments such as Pigment Green 7, 10, 36, 37, and 58 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 coloring layer include C.I. I. Pigment
Blue 15: 1, 15: 2, 15: 3, 15: 4 blue pigments can be used. For example, C.I. I. Pigment Violet 23 purple pigment can also be mixed and used.

  In addition, in combination with the above organic pigments, in order to ensure good coatability, sensitivity, developability, etc. while balancing saturation and lightness, inorganic pigments should be used in combination as long as the liquid crystal resistance is not lowered. Is also possible. 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 deteriorate liquid crystal resistance and heat resistance.

  The transparent resin used in 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. In addition, linear polymers containing acid anhydrides such as styrene-maleic anhydride copolymer and α-olefin-maleic anhydride copolymer can be obtained from (meth) acrylic compounds having hydroxyl groups such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  A polymerizable monomer or oligomer is used as the photocrosslinking agent. Polymerizable monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (meta ) 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, penta Erythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neope N-glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, methylolated melamine (meth) acrylate, epoxy (meth) acrylate, Various acrylic and methacrylic esters such as caprolactone-modified dipentaerythritol hexaacrylate and urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide N-hydroxymethyl (meth) acrylamide, N-vinylformamide, acrylonitrile and the like. These can be used alone or in admixture of two or more.

  The amount added is preferably as long as it does not impair applicability and development suitability, and is about 20% to 80% by weight, more preferably about 50% to 70% by weight, based on the total solid content of the colored composition. is there. If the addition amount is less than this range, the crosslinkability is insufficient and the liquid crystal resistance is deteriorated. If the addition amount is more than this range, unevenness and pinholes are likely to occur when the colored composition is applied, and the applicability is remarkably deteriorated. The liquid solubility is remarkably lowered and the development suitability is poor.

  When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the coloring composition.

  As photopolymerization initiators, 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'-methyldiphenyl sulfide, 3 Benzophenone compounds such as 3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4- Thioxanthone compounds such as 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 (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine compounds such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], Oxime ester compounds such as O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenyl Phosphine compounds such as phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphorquinone, ethyl anthraquino Quinone compounds such as borate compounds, carbazole compounds, imidazole compounds, titanocene compounds and the like. These photopolymerization initiators can be used alone or in combination.

  The amount of the photopolymerization initiator used is preferably 0.5 to 50% by weight, more preferably 3 to 30% by weight, 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 weight, more preferably 3 to 40% by weight 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, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-to Azine, 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 weight, more preferably 1 to 20% by weight, based on the total solid content of the colored composition. If the amount is less than 0.1% by mass, the effect of adding a polyfunctional thiol is insufficient.

  Moreover, a thermal crosslinking agent can also be added as needed. 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. Spin coating, dip coating, die coating, etc. are usually used as the means for coating, but it is not limited to these as long as it is a method capable of coating with a uniform film thickness on a 40 to 60 cm square substrate. 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 to 2.5 μm. A photosensitive coloring composition is applied and 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 those obtained by adding an appropriate surfactant to them. After development, it is washed with water and fired to obtain a pixel having a colored layer 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 pixel having a colored pattern in which a necessary number of colors are combined, that is, a colored layer of a plurality of colors.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
<Example 1>

[Formation of transparent resin layer]
A polyimide-based alignment film material (trade name “SANEVER SE-5300”, manufactured by Nissan Chemical Industries, Ltd.) was formed as a transparent resin layer on a glass substrate, which is a transparent substrate, so as to have a film thickness of 400 nm. The refractive index of the glass substrate was 1.51, and the refractive index of the formed transparent resin layer was 1.63.
[Formation of resin black matrix layer]
(Preparation of photosensitive black composition)
-Black coloring composition The black coloring composition was produced by mixing and stirring a mixture having the following composition (pigment concentration in solid content: 30.7%).
Carbon black dispersion: 28.5 parts by weight, made by Gokoku Color Co., Ltd. (TPBK-2016)
Resin: 10.3 parts by weight V259-ME (manufactured by Nippon Steel Chemical Co., Ltd.) (solid content 56.1% by weight)
Monomer: DPHA (manufactured by Nippon Kayaku Co., Ltd.) 2.58 parts by weight Initiator: 0.86 parts by weight OXE-02 (manufactured by Ciba Specialty Chemicals)
Solvent: 92.0 parts by weight Propylene glycol monomethyl ether acetate ethyl-3-ethoxypropionate Leveling agent: 1.3 parts by weight (formation of resin black matrix layer)
On the transparent substrate on which the transparent resin layer was formed, the black colored composition was applied by spin coating so as to have a film thickness of 1.5 μm. After drying at 100 ° C. for 3 minutes, the pattern exposure is 200 mJ with an exposure machine, developed with an alkali developer for 60 seconds, heat-treated at 230 ° C. for 60 minutes, fixed, and the grid-like black matrix layer is formed. It formed on the transparent substrate. The alkaline developer has the following composition. In the following examples and comparative examples, development is performed using this alkaline developer.
Sodium carbonate 1.5% by weight
Sodium bicarbonate 0.5% by weight
Anionic surfactant 8.0% by weight
("Peralex NBL" manufactured by Kao Corporation)
90% by weight of water
[Formation of colored layer]
(Production of red, green and blue colored compositions)
-Red coloring composition After stirring and mixing the mixture of the following composition uniformly, it disperse | distributed with the sand mill for 5 hours using the glass bead of diameter 1mm, Then, it filtered with the filter of 5 micrometers, and produced the dispersion of the red pigment.
Red pigment: C.I. I. 18 parts of Pigment Red 254 ("Ilgar For Red B-CF" manufactured by Ciba Specialty Chemicals)
Red pigment: C.I. I. Pigment Red 177 2 parts (“Chromophthal Red A2B” manufactured by Ciba Specialty Chemicals)
Dispersant 2 parts ("Ajisper PB821" manufactured by Ajinomoto Fine Techno Co., Ltd.)
Acrylic varnish (solid content 20%) 50 parts 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 a red colored composition.
72 parts of the above dispersion 8 parts of caprolactone-modified dipentaerythritol hexaacrylate (“Kayarad DPCA-30” manufactured by Nippon Kayaku Co., Ltd.)
10 parts of dipentaerythritol hexaacrylate (“Kayarad DPHA” manufactured by Nippon Kayaku Co., Ltd.)
10 parts of methylated melamine resin (“MW30” manufactured by Sanwa Chemical Co., Ltd.)
Photoinitiator 3 parts ("Irgacure 907" manufactured by Ciba Specialty Chemicals)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 1 part Cyclohexanone 253 parts Green coloring composition After uniformly stirring and mixing a mixture of the following composition, using a glass bead with a diameter of 1 mm, After dispersing for 5 hours, the mixture was filtered through a 5 μm filter to prepare a green pigment dispersion.
Green pigment: C.I. I. Pigment Green 36
(“Rionol Green 6YK” manufactured by Toyo Ink Co., Ltd.) 16 parts Yellow pigment: C.I. I. Pigment Yellow 150 8 parts ("Funchon First Yellow Y-5688" manufactured by Bayer)
Dispersant ("Disperbyk-163" manufactured by Big Chemie) 2 parts Acrylic varnish (solid content 20%) 102 parts Thereafter, 128 parts of the above dispersion was used, and the mixture of the following composition was further stirred and mixed to be uniform. Filtration through a 5 μm filter gave a green colored composition.
14 parts of trimethylolpropane triacrylate (Shin Nakamura Chemical Co., Ltd. “NK Ester ATMPT”)
Photoinitiator 4 parts ("Irgacure 907" manufactured by Ciba Specialty Chemicals)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 2 parts Cyclohexanone 257 parts

-Blue coloring composition After stirring and mixing the mixture of the following composition uniformly, it disperse | distributed with the sand mill for 5 hours using the glass beads of diameter 1mm, Then, it filtered with a 5 micrometer filter, and produced the dispersion of the blue pigment.
Blue pigment: C.I. I. Pigment Blue 15
("Rionol Blue ES" manufactured by Toyo Ink Co., Ltd.) 30 parts Purple pigment: C.I. I. Pigment Violet 23
("Pariogen Violet 5890" manufactured by BASF) 2 parts Dispersant ("Sols Birds 20000" manufactured by Zeneca) 6 parts Acrylic varnish (solid content 20%) 200 parts Thereafter, the mixture having the following composition was stirred and mixed to be uniform Then, it was filtered through a 5 μm filter to obtain a blue colored composition.
238 parts of the above dispersion 19 parts of trimethylolpropane triacrylate (“NK ester ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.)
Photoinitiator 4 parts ("Irgacure 907" manufactured by Ciba Specialty Chemicals)
Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 2 parts Cyclohexanone 214 parts

(Formation of colored layer)
Using the obtained red colored composition, green colored composition, and blue colored composition, a colored layer serving as a pixel was formed in the following manner.
The red coloring composition was applied by spin coating so as to have a film thickness of 2 μm on the glass substrate on which the transparent resin layer and the black matrix layer were formed. After drying, a striped pattern was exposed with an exposure machine, developed with an alkaline developer for 90 seconds, heated at 230 ° C. for 20 minutes, fixed, and a striped red colored layer was formed on the transparent substrate.

  Next, the green coloring composition is similarly applied by spin coating so that the film thickness becomes 2 μm. After drying, the green colored layer adjacent to the red colored layer was formed by exposing and developing the striped colored layer in a position different from the red colored layer with an exposure machine.

Further, in the same manner as red and green, the blue colored composition was formed with a blue colored layer adjacent to the red colored layer and the green colored layer with a film thickness of 2 μm.
The color filter of Example 1 was obtained by the above process.

<Example 2>
Each layer was formed in the same manner as in Example 1 except that the thickness of the transparent resin layer was 280 nm, and a color filter of Example 2 was obtained.

<Example 3>
Each layer was formed in the same manner as in Example 1 except that the thickness of the transparent resin layer was changed to 170 nm, and a color filter of Example 3 was obtained.

<Comparative Example 1>
A resin black matrix layer and a colored layer were formed in the same manner as in Example 1 without providing the transparent resin layer, and the color filter of Comparative Example 1 was obtained.

<Comparative example 2>
[Formation of transparent resin layer]
On the glass substrate which is a transparent substrate, an overcoat material (“JSS-727-S2” manufactured by JSR Corporation) was formed as a transparent resin layer so as to have a film thickness of 400 nm. The refractive index of the glass substrate was 1.51, and the refractive index of the formed transparent resin layer was 1.52.
[Formation of resin black matrix layer and colored layer]
Each layer was formed in the same manner as in Example 1 to obtain a color filter of Comparative Example 2.

<Comparative Example 3>
Each layer was formed in the same manner as in Comparative Example 2 except that the thickness of the transparent resin layer was 280 nm, and a color filter of Comparative Example 3 was obtained.

  Table 1 shows the results of evaluating the color filters of Examples 1 to 3 and Comparative Examples 1 to 3. In Examples 1 to 3 that satisfy the relations of Equation (1) and Equation (2), the reflectance at 550 nm was about half that of Comparative Example 1 in which no transparent resin layer was provided. On the other hand, in the comparative examples 2 and 3 that do not satisfy the relationship of the mathematical formulas (1) and (2), the effect of reducing the reflectance was not obtained.

It is sectional drawing which shows the outline of an example of the conventional color filter. It is sectional drawing which shows the outline of an example of the color filter of this invention. It is other examples of the color filter of this invention, Comprising: It is sectional drawing which shows the outline at the time of providing the transparent resin layer between the transparent substrate and the resin black matrix layer, and removing the transparent resin layer of the colored layer part.

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Resin black matrix layer 3 ... Transparent resin layer 4 ... External light 5 ... Colored layer 6 ... Reflected light Re-1 ... Reflected light 1
Re-2 ... Reflected light 2
n ₀ : refractive index of transparent substrate n _1: refractive index of resin black matrix layer n _2: refractive index of transparent resin layer

Claims (7)

In a color filter having at least a resin black matrix layer and a colored layer formed on a transparent substrate, when the refractive index of the transparent substrate is n ₀ between the transparent substrate and the resin black matrix layer, the following formula (1) A transparent resin layer having a refractive index n ₂ and a film thickness d ₂ satisfying

  The color filter according to claim 1, wherein N = 4 in the formula (1). The refractive index n ₂ of the transparent resin layer satisfies the following formula (2), where n _{0 is} the refractive index of the transparent substrate and n ₁ is the refractive index of the resin black matrix layer. Or the color filter of Claim 2.

The color filter according to claim 3, wherein a refractive index n ₂ of the transparent resin layer satisfies the following formula (3).

  A liquid crystal display device comprising the color filter according to claim 1.   6. The liquid crystal display device according to claim 5, wherein the liquid crystal display device is a transflective liquid crystal display device.   6. The liquid crystal display device according to claim 5, wherein the liquid crystal display device is a reflective liquid crystal display device.

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