JP2011128181A - Green-color colorant composition for color filter, color filter base substrate, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-film color filter which has ultrahigh color purity and an ultrahigh contrast ratio. <P>SOLUTION: A green-color colorant composition for a color filter contains at least a resin, a solvent, a pigment dispersant, a green-color pigment and a yellow-color pigment. In this case, the green-color colorant composition for a color filter contains a copper azomethine based pigment as the yellow-color pigment, and additionally contains, as the pigment dispersant, a copper phthalocyanine based pigment derivative which is obtained by introducing a sulfonic acid group into a copper phthalocyanine based pigment. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a green colorant composition for a color filter, a color filter substrate and a liquid crystal display device used for a liquid crystal display or the like.

Liquid crystal displays are used in various applications such as notebook computers, personal digital assistants, digital cameras, and desktop monitors, taking advantage of their characteristics such as light weight, thinness, and low power consumption.
Recently, in order to faithfully reproduce the vivid colors of crimson roses that could not be expressed on conventional CRT televisions and the beautiful green color of tropical seas, the color display range was expanded and the NTSC standard ratio was increased. There is a strong demand to approach 100%. Note that the NTSC standard ratio of 100% indicates that the chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram of RGB colors are R (0.670, 0.330) and G (0.210, 0.710), respectively. ), B (0.150, 0.060).
In addition to expanding the color reproduction range, liquid crystal displays are required to improve display quality by increasing brightness and contrast. However, there is a trade-off relationship between the color reproduction range and the transmittance, and the color reproduction range and the contrast ratio, and there is a problem that the transmittance and the contrast ratio are lowered when the color reproduction range is expanded.
In order to obtain a liquid crystal display with a wide color reproduction range and high brightness, it is important to select the pigment used in each pixel of the color filter so as to match the light transmission characteristics of the backlight. It is often used after being toned at a certain ratio. On the other hand, in order to obtain a liquid crystal display with a high contrast ratio, it is important to disperse the pigment used in each pixel of the color filter into fine and stable particles. Various studies have been made on dispersion stabilization.

In Patent Document 1, C., which is a brominated copper phthalocyanine pigment as a green pigment, is used for G pixels of a color filter. I. Pigment Green (PG) 36, C.I. which is a copper azomethine pigment as a yellow pigment. I. By using Pigment Yellow (PY) 129, high brightness is achieved. However, y in the chromaticity coordinates (x, y) is 0.58 or less, and there is a problem that the color purity is low. Furthermore, Patent Document 1 does not describe the dispersion stabilization of PY129 and does not describe the contrast ratio.
In Patent Document 2, high brightness is achieved by using PG36 as a green pigment and PY129 as a yellow pigment. However, there is a problem that the chromaticity coordinate y is 0.55 or less and the color purity is low. Further, Patent Document 2 does not describe a method for stabilizing PY129 dispersion, and there is a problem that the contrast ratio is as low as about 1000.
In Patent Document 3, PG36 is used as a green pigment and PY129 is used as a yellow pigment. However, there is a problem that y of chromaticity coordinates (x, y) is 0.58 or less and color purity is low. Further, Patent Document 3 does not describe a method for stabilizing PY129 dispersion, and has a problem that the contrast ratio is as low as about 1000.
In Patent Document 4, high color purity is achieved by using PG7, PG36, and PY129. However, the film thickness when the chromaticity coordinate y is 0.67 is 2.7 μm, and there is a problem that high color purity cannot be achieved with a thin film. In Patent Document 4, although the copper azomethine pigment PY129 is dispersed using a copper azomethine sulfonated product, there is a problem that the contrast ratio is as low as about 2000.
As described above, the G pixel of the current color filter uses toned green and yellow pigments, but there is a problem that the film thickness increases when attempting to expand the color reproduction range, and contrast is increased. There is also a problem that the ratio decreases.

Japanese Patent Laid-Open No. 09-203808 JP 2008-33342 A Japanese Patent Laid-Open No. 2003-227921 JP 2009-35671 A

  An object of the present invention is to provide a color filter that is a thin film and has an ultrahigh color purity and an ultrahigh contrast ratio. Furthermore, it aims at providing the color filter which becomes high-intensity.

1. In a green colorant composition for a color filter containing at least a resin, a solvent, a pigment dispersant, a green pigment and a yellow pigment, a copper azomethine pigment is contained as a yellow pigment, and a copper phthalocyanine pigment is sulfonic acid as a pigment dispersant. A green colorant composition for color filters, comprising a copper phthalocyanine pigment derivative having a group introduced therein.
2. 2. The green colorant composition for a color filter according to 1, wherein the average number of introduced sulfonic acid groups per molecule of the copper phthalocyanine pigment derivative is 1.8 to 2.1.
3. Copper azomethine pigments are C.I. I. Pigment Yellow 129, and C.I. I. 3. The green colorant composition for a color filter according to item 1 or 2, which contains CI Pigment Yellow 150.
4). A chlorinated copper phthalocyanine pigment is contained as a green pigment, and the average number of introduced chlorine atoms per molecule of chlorinated copper phthalocyanine of the chlorinated copper phthalocyanine pigment is 15.1-16.0. The green coloring agent composition for color filters in any one of Claims 1-3.
5). The green colorant composition for a color filter according to any one of items 1 to 4, further comprising a zinc phthalocyanine pigment as a green pigment.
6). 6. A color filter substrate in which pixels comprising a colored film provided in a desired pattern for each color with an arbitrary number of colors on a transparent substrate, wherein the colored film is any one of items 1 to 5. A color filter substrate formed of a green colorant composition for a color filter.
A liquid crystal display device comprising the color filter substrate according to 7.6.

Since the green colorant composition for color filters of the present invention contains a green pigment, a copper azomethine yellow pigment, and a copper phthalocyanine pigment derivative, the dispersion stability of the copper azomethine pigment is extremely excellent. Therefore, the color filter substrate manufactured using the green colorant composition of the present invention has an ultrahigh contrast ratio and ultrahigh color purity, and the liquid crystal display manufactured using the color filter substrate of the present invention has a high display quality. Thus, a high color reproduction range is obtained.

The present invention relates to a green colorant composition for a color filter containing at least a resin, a solvent, a pigment dispersant, a green pigment and a yellow pigment, containing a copper azomethine pigment as a yellow pigment, and further a copper phthalocyanine as a pigment dispersant It is a green colorant composition for a color filter containing a copper phthalocyanine pigment derivative having a sulfonic acid group introduced into the pigment.
As a dispersant for dispersing and stabilizing an organic pigment, it is generally known that a pigment sulfonated derivative having the same skeleton as an organic pigment can be used as a pigment dispersant to improve dispersion stability. Therefore, it is conceivable to use a sulfonated derivative of a copper azomethine pigment as a dispersant in order to disperse a copper azomethine pigment having poor dispersibility. However, with regard to this copper azomethine pigment, dispersibility does not improve even when a sulfonated derivative is used as a dispersant, and as a result, only a color filter having a low contrast ratio can be obtained.
As a result of intensive studies by the inventors, surprisingly, the dispersion stability of the copper azomethine pigment is remarkably improved by using a sulfonated derivative of a copper phthalocyanine pigment having a completely different structure from that of the copper azomethine pigment. It has been found that this significantly improves the color purity and contrast ratio of the color filter.

In the present invention, the average number of introduced sulfonic acid groups of the pigment dispersant, that is, the copper phthalocyanine pigment derivative, contained in the green colorant composition is preferably 1.8 to 2.1, and preferably 1.9 to 2.0. Further preferred. Even if the average number of introduced sulfonic acid groups is less than 1.8 or more than 2.1, the dispersion stability of the copper azomethine pigment is lowered and the contrast ratio of the color filter is lowered. By setting the number of introduced sulfonic acid groups in the copper phthalocyanine pigment derivative within the above range, the dispersion stability of the copper azomethine pigment can be improved, and the contrast ratio of the color filter can be improved.
In the present invention, examples of the copper azomethine pigment contained as a yellow pigment in the green colorant composition include PY65, PY129, PY153, etc., and PY129 is particularly preferable because the coloring power of the pigment is strong and the hue is excellent.

Furthermore, the green colorant composition of the present invention may contain a yellow pigment other than the copper azomethine pigment. There is no restriction | limiting in particular as the yellow pigment, PY12, 13, 17, 20, 24, 83, 86, 93, 95, 109, 110, 117, 125, 137, 138, 139, 147, 148, 150, 154, 166, 168, 185 and the like. Among them, PY150 is preferable because it is easy to increase the luminance and contrast ratio of the color filter.
In the green colorant composition of the present invention, particularly when PY129 and PY150 are combined as yellow pigments, in addition to the ultra-high color purity and the ultra-high contrast ratio, high luminance is preferable. The weight mixing ratio of PY129 and PY150 is particularly preferably PY129: PY150 = 70: 30 to 50:50. When the PY129 in the yellow pigment is more than 70% by weight, the luminance of the color filter tends to be lowered, and when the PY129 is less than 50% by weight, the color purity tends to be lowered.
In the present invention, paying attention to the fact that the transmission spectrum shapes (rise wavelength, peak slope, etc.) of PY129 and PY150 are different, the weight mixing ratio of PY129 and PY150 is optimized to the above range, so that the color filter It was possible to find a synergistic effect by combining PY129 and PY150 while achieving both ultra-high color purity and high brightness.

  In the present invention, examples of the green pigment contained in the green colorant composition include chlorinated copper phthalocyanine pigments, brominated copper phthalocyanine pigments, and brominated zinc phthalocyanine pigments. A chlorinated copper phthalocyanine pigment is preferable because the color filter can be highly purified, and a brominated zinc phthalocyanine pigment is preferable because the color filter can be brightened.

The chlorinated copper phthalocyanine pigment usually has 1 to 16 chlorine atoms introduced per molecule of chlorinated copper phthalocyanine. A pigment composed of an aggregate of copper phthalocyanine molecules having one chlorine atom introduction number is PB15: 1, a pigment composed of an aggregate of copper phthalocyanine molecules having a chlorine atom introduction number of 4-8 is PG37, and the number of chlorine atom introductions is 12. A pigment composed of an aggregate of ˜16 copper phthalocyanine molecules is designated as PG7. When a chlorinated copper phthalocyanine pigment is used as the green pigment in the present invention, the average number of introduced chlorine atoms per molecule of copper phthalocyanine in the chlorinated copper phthalocyanine pigment is preferably 15.1 to 16.0, and 15.5 16.0 is more preferable. By setting the average number of introduced chlorine to 15.5 to 16.0, the color filter can have high color purity and high brightness. The average number of introduced chlorine atoms per molecule of chlorinated copper phthalocyanine is measured, for example, by measuring the negative ions of the chlorinated copper phthalocyanine pigment by the laser desorption ionization method, and the mass (m) and charge ( The ratio (m / z) of z) is in the range of 10 to 2000, and the average number of introduced chlorine atoms in the chlorinated copper phthalocyanine pigment can be determined from the obtained peak intensity ratio of m / z.
In the present invention, when a chlorinated copper phthalocyanine pigment is used as a green pigment in the present invention, the preparation method is, for example, by heating and melting copper phthalocyanine pigment together with sodium chloride and aluminum chloride, and adding chlorine gas to the melt. By putting it in, it can be synthesized. In addition, by appropriately controlling the synthesis conditions as follows, the average number of introduced chlorine atoms per copper phthalocyanine molecule can be 15.1 to 16.0.
When synthesizing the chlorinated copper phthalocyanine pigment used in the present invention, the weight mixing ratio of the raw material copper phthalocyanine pigment, sodium chloride, and aluminum chloride is preferably copper phthalocyanine: sodium chloride: aluminum chloride = 1: 1: 1-1: 20: 20. If the mixing ratio is less than 1: 1: 1, the copper phthalocyanine pigment cannot be melted and the number of introduced chlorine atoms may be smaller than 15.1, and if the mixing ratio is larger than 1:20:20. Production efficiency decreases.
Moreover, it is desired that the temperature at which chlorine gas is introduced and the chlorination reaction is performed is preferably 150 to 200 ° C. If the chlorination reaction temperature is too high or too low, it will be difficult to set the number of introduced chlorine atoms per molecule to 15.1-16.0.
Furthermore, the time for introducing chlorine gas and performing the chlorination reaction is preferably 1 to 50 hours, more preferably 5 to 25 hours. If the chlorination reaction time is shorter than 1 hour, it is difficult to set the number of introduced chlorine atoms per molecule to 15.1-16.0.
In the chlorinated copper phthalocyanine pigment used in the present invention, the average number of substituents other than chlorine atoms per molecule of chlorinated copper phthalocyanine is 0.9 to 0. Examples of the substituent include bromine atom, hydrogen atom, hydroxyl group, nitro group, amino group, cyano group, alkyl group, cyclic alkyl group, alkoxy group, cyclic alkoxy group, alkoxyalkyl group, alkylthio group, cyclic alkylthio group, alkenyl. Group, cyclic alkenyl group, alkenyloxy group, alkylamino group, alkylcarbonyl group, alkoxycarbonyl group, alkylcarbonyloxy group, alkylaminocarbonyl group, fluoroalkyl group, fluoroalkoxy group, fluoroalkylthio group, carboxyl group, formyl group, Sulfonic acid group, alkylsulfonyl group, alkylaminosulfonyl group, alkylaminosulfonic acid group, chlorosulfone group, carbamide group, sulfonamido group, aryl group, aryloxy group, arylthio group, aliphatic compound Such ring group or an aromatic heterocyclic group.
The green colorant composition of the present invention is prepared by dispersing a pigment dispersant, a green pigment, a copper azomethine yellow pigment and the like together with a solvent by a disperser to produce a green pigment dispersion, Manufactured by adding additives. When producing this green pigment dispersion, it is important to contain a copper phthalocyanine pigment derivative having a sulfonic acid group introduced together with a copper azomethine yellow pigment. That is, since the pigment is in a state of secondary particles in which primary particles are aggregated in a powder state (second particle size is usually 1 to 50 μm), after adding a solvent and a resin if necessary, the disperser is used. It is necessary to apply a shear stress to the secondary particles of the pigment to refine them into particles of primary particles or a collection of small numbers of primary particles.
A sand mill, a ball mill, a bead mill, a three-roll mill, an attritor or the like is used as a disperser for applying a shear stress to the coarse pigment particles in a solvent. In particular, a bead mill is preferably used because of excellent dispersion efficiency. Examples of the dispersed beads include zirconia beads, alumina beads, glass beads, and the like. In order to reduce the size efficiently, it is particularly preferable to use zirconia beads. As the dispersion conditions, the shear stress can be adjusted to an appropriate level by appropriately controlling the bead diameter of the zirconia beads, the peripheral speed of the disperser, the dispersion time, etc., and the coarse particles of the pigment can be efficiently refined. be able to.
In the present invention, the green pigment and the yellow pigment may be mixed and dispersed, or may be dispersed alone without mixing, but the dispersion composition for each pigment (dispersant) is more preferably dispersed separately. Seeds, dispersant amount, etc.) and dispersion conditions (dispersed bead grains, dispersion time, etc.) can be optimized. As a result, the contrast ratio as a color filter is likely to be high, which is preferable. Furthermore, it is preferable to separately disperse the pigments separately because the weight mixing ratio of each pigment is not limited and the range of toning is widened.

It is preferable to add a polymer dispersant to the green pigment dispersion used in the present invention. By adding a polymer dispersant, further improvement in dispersion stability can be expected. As the polymer dispersant that can be used, those having a basic group in the structure thereof are preferable. Examples of commercially available products include “Solsperse” (Avicia), “EFKA” (Efka), “Ajisper”. (Ajinomoto Fine Techno Co., Ltd.), “BYK” (Bic Chemie Co., Ltd.) and the like can be preferably used. The use of “Solsparse” 24000, “EFKA” 4300, 4330, 4340, “Ajisper” PB821, PB822, “BYK” 161-163, 2000, 2001 is preferred because the dispersion stabilization effect is enhanced. The addition amount of the polymer dispersant used in the present invention is not particularly limited, but is preferably 2 to 100 parts by weight, more preferably 10 to 50 parts by weight with respect to 100 parts by weight of the pigment. is there. If the addition amount of the polymer dispersant is less than 2 parts by weight, good pigment dispersion stability cannot be obtained, and if it is more than 100 parts by weight, the developability may be poor.
The resin used in the green colorant composition of the present invention is not particularly limited, and a resin usually used for a color filter, that is, an acrylic, epoxy, or polyamic acid resin can be preferably used. . Depending on the resin used, it can be non-photosensitive or photosensitive, and can be appropriately selected according to the color filter manufacturing process.
Hereinafter, the case where acrylic resin is used as a typical example of resin used for the photosensitive green colorant composition will be described. The acrylic resin generally contains at least an acrylic polymer, a polyfunctional monomer or oligomer, and a photopolymerization initiator in order to provide photosensitivity.
The acrylic polymer that can be used is not particularly limited, but a copolymer of an unsaturated carboxylic acid and an ethylenically unsaturated compound can be preferably used. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides.

  These may be used alone or in combination with other copolymerizable ethylenically unsaturated compounds. Specific examples of the copolymerizable ethylenically unsaturated compound include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, isopropyl acrylate, n-propyl methacrylate, and methacrylic acid. Isopropyl, n-butyl acrylate, n-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, iso-butyl acrylate, iso-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, N-pentyl acrylate, n-pentyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, and other unsaturated carboxylic acid alkyl esters, styrene, p-methyls Rene, aromatic vinyl compounds such as o-methylstyrene, m-methylstyrene and α-methylstyrene, unsaturated carboxylic acid aminoalkyl esters such as aminoethyl acrylate, unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate and glycidyl methacrylate, Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate, vinyl cyanide compounds such as acrylonitrile, methacrylonitrile, and α-chloroacrylonitrile, aliphatic conjugated dienes such as 1,3-butadiene and isoprene, acryloyl groups at the terminals, Alternatively, macromonomers such as polystyrene, polymethyl acrylate, polymethyl methacrylate, polybutyl acrylate, polybutyl methacrylate, and polysilicone having a methacryloyl group And the like, but is not limited to these.

  Examples of polyfunctional monomers that can be used include bisphenol A diglycidyl ether (meth) acrylate, poly (meth) acrylate carbamate, modified bisphenol A epoxy (meth) acrylate, adipic acid 1,6-hexanediol (meth) acrylic acid ester , Phthalic anhydride propylene oxide (meth) acrylic acid ester, trimellitic acid diethylene glycol (meth) acrylic acid ester, rosin modified epoxy di (meth) acrylate, alkyd modified (meth) acrylate, tripropylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaeryth Torutori (meth) acrylate, triacrylformal, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate. These can be used alone or in combination. A mixture of two or more of these or a mixture with other compounds is used.

  There are no particular limitations on the photopolymerization initiator, and known ones can be used, such as benzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2 , 2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyldimethyl ketal, α-hydroxyisobutylphenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (Methylthio) phenyl] -2-morpholino-1-propane, t-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1, 4-naphthoquinone, 9,10-phenanthraquinone, 1,2-benzoanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, etc. Can be given.

The solvent used in the green colorant composition of the present invention is not particularly limited. For example, methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl Ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol ethyl methyl ether, (poly) alkylene glycol ether solvents such as diethylene glycol butyl ethyl ether, or propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl acetoacetate , Methyl-3-methoxypropionate, ethyl-3-ethoxypro Fatty esters such as onate, methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, or aliphatic alcohols such as ethanol, butanol, isopropanol, 3-methyl-3-methoxybutanol, cyclopentanone, cyclohexanone Such ketones can be used, and these can be used alone or in combination of two or more. Mixing with other solvents is also preferably used.
A surfactant, an adhesion improver, a curing accelerator, and the like can also be added to the green colorant composition of the present invention.

  The weight mixing ratio of the pigment component and the resin component in the green colorant composition of the present invention is usually 10:90 to 60:40, preferably 20:80 to 50:50. If the amount of the pigment component is less than 10% by weight, the color purity of the color filter tends to be lowered, and if the amount of the pigment component is more than 60% by weight, the reliability of the color filter tends to be lowered. When an acrylic resin is used in the present invention, an acrylic polymer, an acrylic monomer, and a polymer dispersant are used as a resin component, and a pigment and a pigment derivative are used as a pigment component.

The weight mixing ratio of the green pigment and the yellow pigment in the green colorant composition of the present invention is not particularly limited, but is preferably green pigment: yellow pigment = 90: 10 to 10:90, and green pigment: yellow pigment = 70. : 30 to 30:70 is more preferable. If the amount of green pigment is too small or the amount of yellow pigment is too small, the color filter cannot be highly purified.
In the green colorant composition of the present invention, the solid content concentration of the pigment and the resin is preferably in the range of 5 to 20% by mass from the viewpoints of coating property and drying property.
In the present invention, the dispersion stability of the pigment in the pigment dispersion can be evaluated using the viscosity and the Casson yield value. The better the dispersion stability of the pigment, the smaller the viscosity and yield value of the pigment dispersion. If the dispersion stability of the pigment in the pigment dispersion is good, the dispersion stability of the green colorant composition produced by adding a resin, a solvent or the like to the pigment dispersion is usually good.
The viscosity of the green colorant composition of the present invention is preferably in the range of 1 to 20 mPa · s, more preferably in the range of 2 to 10 mPa · s. The yield value of the green colorant composition is preferably 1 × 10 ⁻³ Pa or less, and more preferably 1 × 10 ⁻⁴ Pa or less. If the viscosity and the yield value are within the above ranges, it can be said that the dispersion stability of the pigment of the green colorant composition is good.
Hereinafter, a method for producing a color filter using the green colorant composition of the present invention will be described.
The color filter usually has a structure in which pixels of three colors of red, green, and blue are formed on a transparent substrate on which a black matrix is formed.
The color filter of the present invention contains a copper azomethine pigment as a yellow pigment in a green colorant composition for a color filter containing at least a resin, a solvent, a pigment dispersant, a green pigment and a yellow pigment. It is necessary to produce using a green colorant composition for a color filter containing a copper phthalocyanine pigment derivative in which a sulfonic acid group is introduced into a copper phthalocyanine pigment as a pigment dispersant. The red colorant composition for forming red pixels and blue pixels, and the blue colorant composition are not particularly limited. For example, as with the green colorant composition of the present invention described above, a resin, It is prepared by toning with a pigment system comprising a main pigment and a sub-pigment in a solvent.
First, as a method of applying the colorant composition on the substrate, a method of applying the substrate to the substrate by a spin coater, a bar coater, a blade coater, a roll coater, a die coater, an ink jet printing method, a screen printing method, etc. Various methods such as a method of immersing in a solution and spraying a solution onto a substrate can be used. As the substrate, a transparent substrate such as soda glass, alkali-free glass, borosilicate glass, or quartz glass is usually used. After coating the green colorant composition on the transparent substrate by the method as described above, a coating film of the green colorant composition is formed by air drying, heat drying, vacuum drying or the like.
Next, when the green colorant composition is photosensitive, a mask is placed on the coating film of the photosensitive colorant composition, and an ultrahigh pressure mercury lamp, a chemical lamp, a high pressure mercury lamp, or the like is used to selectively select the ultraviolet color. Perform exposure.

  Thereafter, development is performed with an alkaline developer. Examples of the alkaline substance used in the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, ethylamine, n-propylamine, and the like. Examples include secondary amines such as tertiary amines, diethylamine and di-n-propylamine, tertiary amines such as triethylamine and methyldiethylamine, and organic alkalis such as tetramethylammonium hydroxide.

Thereafter, the obtained coating film pattern is heat-treated to form a color filter in which pixels are patterned. The heat treatment is usually carried out in air, in a nitrogen atmosphere, or in a vacuum at a temperature of 150 to 350 ° C., preferably 180 to 250 ° C., for 0.5 to 5 hours, continuously or stepwise. Done. By this heating step, curing of the resin component in the green colorant composition proceeds.
When the patterning process as described above is sequentially performed for each color such as red, green, and blue, a color filter for a liquid crystal display device can be manufactured. The patterning order of each color is not limited.
The film thickness of the green pixel of the color filter of the present invention is usually 1.0 to 2.5 μm, preferably 1.2 to 2.0 μm. When the film thickness is thinner than 1.0 μm, the light absorption becomes small and the color purity of the color filter tends to be lowered. On the other hand, when the film thickness is larger than 2.5 μm, various problems such as a decrease in flatness of the color filter, a decrease in pattern workability, and a decrease in reliability are likely to occur.
The color purity of the green pixel of the color filter of the present invention can be evaluated from, for example, the relationship between y and the film thickness of chromaticity coordinates (x, y) in a C light source XYZ display system known as standard conditions. The green pixel of the color filter usually has higher color purity as the pixel film thickness increases, but the upper limit of the practical film thickness is 2.5 μm as described above. It is required to be purified. In the case of a green pixel, the color purity can be evaluated from the film thickness at a constant y or the film thickness y at a constant film thickness. The smaller the film thickness at a constant y, the more the y at a constant film thickness. The larger the value is, the thinner the film is and the higher the color purity.
In the color filter of the present invention, the film thickness at chromaticity coordinates (x, y) at y = 0.650 is preferably 2.0 μm or less, more preferably 1.8 μm or less, and further preferably 1.6 μm or less. It is desirable. If the film thickness at y = 0.650 is 1.8 μm or less, the color filter can be highly purified with a thin film, and if the film thickness at y = 0.650 is 1.6 μm or less, the color filter Can be highly purified with a thin film.
In the present invention, by adding a copper azomethine pigment and a copper phthalocyanine pigment derivative as a green pigment and a yellow pigment in the green colorant composition, the dispersion stability of the copper azomethine pigment in the green colorant composition is improved. The film thickness at y = 0.650 can be 1.6 μm or less. In general, an LED light source used for a liquid crystal display has a tendency that G pixels have higher color purity than a C light source. If y = 0.650 for a C light source, y = 0. It is considered possible to obtain a color of 660 to 0.700.
In the color filter of the present invention, the contrast ratio at y = 0.650 in the chromaticity coordinates (x, y) is usually 4000 or more, preferably 6000 or more, and more preferably 8000 or more. The larger the contrast ratio of the color filter, the better the display quality of the liquid crystal display. In the present invention, the contrast ratio of the color filter can be 6000 or more by using a green pigment, a copper azomethine yellow pigment, or a copper phthalocyanine pigment derivative.
The luminance of the color filter of the present invention can be evaluated using, for example, the luminance (Y) in the C light source XYZ display system. Usually, in the case of G pixels, the higher the y, the higher the color purity and the smaller Y, and the larger x, the yellowish hue and the larger Y. Therefore, the luminance should be evaluated with a constant chromaticity coordinate (x, y). is required. In the color filter of the present invention, Y in chromaticity coordinates (x, y) = (0.240, 0.650) is preferably 35 or more, more preferably 37 or more. Preferably, in the present invention, by using a highly chlorinated copper phthalocyanine pigment as a green pigment and using PY129 and PY150 as yellow pigments, Y in (x, y) = (0.240, 0.650) is 37 or more. It can be.
On the other hand, in the present invention, by using a brominated zinc phthalocyanine pigment as a green pigment and using PY129 and PY150 as yellow pigments, although the color purity is slightly reduced, Y can be further improved (x, y ) = (0.240, 0.650), Y may be 38 or more.
Next, an example of a liquid crystal display device created using this color filter will be described. The color filter substrate and the array substrate are bonded to each other with a liquid crystal alignment film provided on the substrates and subjected to a rubbing process for liquid crystal alignment, and a spacer for maintaining a cell gap. . Note that a thin film transistor (TFT) element, a thin film diode (TFD) element, a scanning line, a signal line, and the like are provided over the array substrate, whereby a TFT liquid crystal display device and a TFD liquid crystal display device can be manufactured. Next, after injecting liquid crystal from the injection port provided in the seal portion, the injection port is sealed. Next, a liquid crystal display device is completed by mounting an IC driver or the like.

  Hereinafter, the present invention will be described in more detail using preferred embodiments.

  The pigments, pigment derivatives, pigment dispersions, green colorant compositions, and color filters in the examples were evaluated by the following methods.

<Evaluation method>
(Average number of chlorine atoms introduced in chlorinated copper phthalocyanine pigments)
Using a laser time-of-flight mass spectrometer (AXIMA-TOF ² manufactured by Shimadzu Corporation), negative ions of chlorinated copper phthalocyanine pigments were measured by a laser desorption ionization method. For the measurement, a nitrogen laser having a wavelength of 337 nm was used, and no matrix was used. The ratio of the mass (m) of the ions produced by ionization to the charge (z) (m / z) is in the range of 10 to 2000, and the average chlorine of the chlorinated copper phthalocyanine pigment is determined from the obtained m / z intensity ratio. The number of atoms introduced was determined.
(Average number of introduced sulfonic acid groups in pigment derivatives)
Using m-nitrobenzyl alcohol as a matrix, negative ion measurement of the pigment derivative was performed using a fast atom bombardment ionization mass spectrometer (JMS-SX102A, manufactured by JEOL Ltd.). The measurement is carried out in the range of 10 to 2000 in terms of the ratio (m / z) of the mass (m) and charge (z) of ions generated by ionization, and the average sulfonic acid group of the pigment derivative is determined from the obtained m / z intensity ratio. The number of introductions was obtained.
(Viscosity of pigment dispersion and green colorant composition)
The viscosity of the pigment dispersion at 25 ° C. was measured using a conical plate viscometer (RE100L manufactured by Toki Sangyo Co., Ltd.).
(Yield value of pigment dispersion and green colorant composition)
Using a conical plate viscometer (RE100L manufactured by Toki Sangyo Co., Ltd.), the viscosity at different shear rates was measured at three points, and the yield value was determined by using the Casson equation.
From the obtained viscosity and yield value, the dispersion stability of the pigment dispersion and the green colorant composition was evaluated.
(Contrast ratio of color filter)
A colored film formed by coating a green colorant composition on a glass substrate is prepared, placed between the polarizer and the analyzer so that the film surface falls within the entire measurement area, and the polarizer and the analyzer are parallel to each other. The contrast ratio was calculated by measuring the light transmittance (I1) at the time and the ratio (I1 / I2) of the light transmittance (I2) when the polarizer and the analyzer were orthogonal. A polarizing film “NPF-G1220DUN” manufactured by Nitto Denko Corporation was used for the polarizer and the analyzer. “FL8A-EX / 70” manufactured by Meidaku System, which is a backlight unit using a hot cathode tube as a light source, was used, and “BM-5A” manufactured by Topcon Corporation was used as a color luminance meter.
(Color filter chromaticity)
The chromaticity coordinates (x, y) and luminance (Y) in the C light source XYZ color system of the colored film were measured using a microspectrophotometer “MCPD-2000” manufactured by Otsuka Electronics Co., Ltd.
(The film thickness of the color filter formed from the colorant composition)
The film thickness of the colored film was measured using a surface step meter “Surfcom 1400D” manufactured by Tokyo Seimitsu Co., Ltd.
Reference example 1
(Preparation of chlorinated copper phthalocyanine pigment)
In a glass reaction vessel having a gas introduction tube, 50 g of copper phthalocyanine pigment (“Hosta Palm Blue” (trade name) A2-R, manufactured by Clariant Co., Ltd.), 350 g of sodium chloride, and 350 g of aluminum chloride were added. I put it in. Thereafter, the slurry was heated to 180 ° C. to melt the slurry. Chlorine gas was injected into the molten slurry, and a chlorination reaction was performed at 180 ° C. for 24 hours. After completion of the reaction, the melt was poured into 2000 g of ice water, and the resulting precipitate was filtered. The obtained wet crystals were washed with pure water and then dried at 80 ° C. The operations obtained by drying, washing with pure water, filtering, and drying were repeated 10 times to obtain a chlorinated copper phthalocyanine pigment. When the chlorine introduction number of this chlorinated copper phthalocyanine pigment was measured by the above method, a peak of m / z = 1126 indicating that 16 chlorine atoms were introduced, indicating that 15 chlorine atoms were introduced. A peak at m / z = 1093 and a peak at m / z = 1059 indicating that 14 chlorine atoms were introduced were confirmed. When the number of introduced chlorine was calculated from these peak intensity ratios, it was 87% for 16 introduced chlorine, 11% for 15 introduced chlorine, 2% for 14 introduced chlorine, chlorine The average number of introduced chlorine per molecule of copper phthalocyanine was 15.85.
Reference example 2
(Preparation of chlorinated copper phthalocyanine pigment)
The chlorination reaction was carried out in the same manner as in Reference Example 1 except that the chlorination reaction time was 8 hours to obtain a chlorinated copper phthalocyanine pigment. The average chlorine introduction number of this chlorinated copper phthalocyanine pigment was 15.60.
Reference example 3
(Preparation of copper phthalocyanine pigment derivative)
60 g of PB15: 3 (Clariant “Hosta Palm Blue” B2G) was added to 780 g of fuming sulfuric acid (28% SO ₃ ) heated to 60 ° C. with stirring. After stirring for 3 hours, the mixture was added on 1500 g of ice. After standing for 30 minutes, the resulting suspension was filtered, and the resulting product was washed with 300 ml of pure water. The product was put into 2000 ml of pure water, neutralized with an aqueous ammonia solution (added with an aqueous ammonia solution until the pH reached 7 or more), and filtered. The obtained wet crystals were washed with pure water and then dried at 80 ° C. The operations obtained by drying, washing with pure water, filtering and drying were repeated three times to obtain 69 g of a copper phthalocyanine pigment derivative. Next, after this copper phthalocyanine pigment derivative and ion-exchanged water are mixed, the slurry is dialyzed using a PMMA dialysis module ("Filtizer" (trade name) B3-20A manufactured by Toray Industries, Inc.) A copper phthalocyanine pigment derivative was purified. When the number of introduced sulfonic acid groups in the copper phthalocyanine pigment derivative after the purification was measured by the above method, a peak at m / z = 654 indicating that one sulfonic acid group was introduced was introduced. A peak at m / z = 734 indicating 3 and a peak at m / z = 814 indicating that 3 were introduced were observed. When the number of introduced sulfonic acid groups was calculated from these peak intensity ratios, the average number of introduced sulfonic acid groups was 1.9.

Reference example 4
(Preparation of copper phthalocyanine pigment derivative)
A pigment sulfone was prepared in the same manner as in Reference Example 3 except that 60 g of PB15: 3 (Clariant “Hosta Palm Blue” B2G) was added to 780 g of fuming sulfuric acid (28% SO ₃ ) heated to 80 ° C. And purification. The average number of introduced sulfonic acid groups of this copper phthalocyanine pigment derivative was 2.4.
Reference Example 5
(Preparation of copper phthalocyanine pigment derivative)
A pigment sulfone was prepared in the same manner as in Reference Example 3 except that 60 g of PB15: 3 (“Hosta Palm Blue” B2G manufactured by Clariant) was put into 780 g of fuming sulfuric acid (28% SO ₃ ) heated to 70 ° C. And purification. The average number of introduced sulfonic acid groups in this copper phthalocyanine pigment derivative was 2.1.
Reference Example 6
(Preparation of copper phthalocyanine pigment derivative)
A pigment sulfone was prepared in the same manner as in Reference Example 3 except that 60 g of PB15: 3 (“Hosta Palm Blue” B2G manufactured by Clariant) was added to 780 g of fuming sulfuric acid (28% SO ₃ ) heated to 50 ° C. And purification. The average number of introduced sulfonic acid groups in this copper phthalocyanine pigment derivative was 1.8.
Reference Example 7
(Preparation of copper phthalocyanine pigment derivative)
A pigment sulfone was prepared in the same manner as in Reference Example 3 except that 60 g of PB15: 3 (“Hosta Palm Blue” B2G manufactured by Clariant) was put into 780 g of fuming sulfuric acid (28% SO ₃ ) heated to 40 ° C. And purification. The average number of introduced sulfonic acid groups in this copper phthalocyanine pigment derivative was 1.6.
Reference Example 8
(Preparation of copper azomethine sulfonated pigment derivative)
60 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.) was charged into 780 g of fuming sulfuric acid (28 wt% SO ₃ ) with stirring under ice cooling. . The temperature of the solution during the reaction was 0 to 5 ° C. After stirring for 3 hours, the mixture was poured into 1500 g of ice water. After standing for 30 minutes, the resulting suspension was filtered, and the resulting product was washed with 300 ml of pure water. The product was put into 2000 ml of pure water, an aqueous ammonia solution was added until the pH reached 7 or more with an aqueous ammonia solution, neutralized, and then filtered. The obtained wet crystals were washed with pure water and then dried at 80 ° C. The operations obtained by drying, washing with pure water, filtering and drying were repeated three times to obtain 62 g of a copper azomethine sulfonated derivative.
Next, the copper azomethine pigment derivative was dialyzed in the same procedure as in Reference Example 3. When the number of sulfonic acid groups introduced into the copper azomethine pigment derivative after dialysis was measured by the method described above, only the peak at m / z = 483 indicating that two sulfonic acid groups were introduced into PY129 was found. It was observed that the average number of introduced sulfonic acid groups in the copper azomethine pigment derivative was 2.0.

Reference Example 9
(Preparation of yellow pigment dispersion 1)
97 g of copper azomethine pigment PY129 (manufactured by Ciba Specialty Chemicals, “Irgazine Yellow”, (trade name) 5GLT), 3 g of copper phthalocyanine pigment derivative obtained in Reference Example 3 (average number of introduced sulfonic acid groups) 1.9), 100 g of a polymer dispersant (Bikme Japan Co., Ltd., (trade name) BYK2000), 67 g of an acrylic resin (manufactured by Daicel Chemical, “Cyclomer”, (trade name) CA250), A slurry was prepared by mixing 83 g of propylene glycol monomethyl ether and 650 g of propylene glycol monomethyl ether acetate. The beaker containing the slurry was connected with a circulation type bead mill disperser ("Dynomill" KDL-A manufactured by Willie et Bacofen) and a tube, and zirconia beads having a diameter of 0.3 mm were used as a medium at 3200 rpm for 6 hours. A dispersion treatment was performed to obtain a yellow pigment dispersion 1.

Reference Example 10
(Preparation of yellow pigment dispersion 2)
97 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.), 3 g of copper azomethine pigment derivative obtained in Reference Example 8 (average number of introduced sulfonic acid groups 2 0.0) was carried out in the same manner as in Reference Example 9 to obtain a yellow pigment dispersion 2.
Reference Example 11
(Preparation of yellow pigment dispersion 3)
Dispersion treatment was performed in the same manner as in Reference Example 9, except that 100 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.) was used and no pigment derivative was used. And a yellow pigment dispersion 3 was obtained.

Reference Example 12
(Preparation of yellow pigment dispersion 4)
A yellow pigment dispersion liquid 4 was obtained in the same manner as in Reference Example 9 except that 100 g of PY150 (manufactured by LANXESS, (trade name) E4GNGT) was used and the pigment derivative was not used.
Reference Example 13
(Preparation of yellow pigment dispersion 5)
97 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.), 3 g of copper phthalocyanine pigment derivative obtained in Reference Example 4 (average number of introduced sulfonic acid groups 2 .4) was used in the same manner as in Reference Example 9 to obtain a yellow pigment dispersion 5.
Reference Example 14
(Preparation of yellow pigment dispersion 6)
97 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.), 3 g of copper phthalocyanine pigment derivative obtained in Reference Example 5 (average number of introduced sulfonic acid groups 2 .1) was used in the same manner as in Reference Example 9 to obtain a yellow pigment dispersion 6.
Reference Example 15
(Preparation of yellow pigment dispersion 7)
97 g of copper azomethine pigment PY129 (“Irgazine Yellow” (trade name) 5GLT manufactured by Ciba Specialty Chemicals Co., Ltd.), 3 g of copper phthalocyanine pigment derivative obtained in Reference Example 6 (average number of introduced sulfonic acid groups 1 .8) was used in the same manner as in Reference Example 9 to obtain Yellow Pigment Dispersion Liquid 7.
Reference Example 16
(Preparation of yellow pigment dispersion 8)
97 g of PY129 (“Irgazine Yellow” manufactured by Ciba Specialty Chemicals Co., Ltd., (trade name) 5GLT), 3 g of copper phthalocyanine pigment derivative obtained in Reference Example 7 (average number of introduced sulfonic acid groups: 1.6) A yellow pigment dispersion liquid 8 was obtained by carrying out a dispersion treatment in the same manner as in Reference Example 9 except that
Reference Example 17
(Preparation of green pigment dispersion 1)
100 g of the chlorinated copper phthalocyanine pigment obtained in Reference Example 1 (average number of introduced chlorines: 15.85), 100 g of a polymer dispersant (manufactured by Big Me Japan Co., Ltd., (trade name) BYK2000), 67 g A slurry was prepared by mixing an acrylic polymer (“Cyclomer” A manufactured by Daicel Chemical Industries, Ltd., (trade name) CA250), 40 g of propylene glycol monomethyl ether, and 693 g of propylene glycol monomethyl ether acetate. The beaker containing the slurry was connected with a circulation type bead mill disperser ("Dynomill" KDL-A manufactured by Willy et Bacofen) and a tube, and zirconia beads having a diameter of 0.3 mm were used as a medium at 3200 rpm for 3 hours. Dispersion treatment was performed to obtain a green pigment dispersion 1.

Reference Example 18
(Preparation of green pigment dispersion 2)
A green pigment dispersion 2 was obtained in the same manner as in Reference Example 17 except that 100 g of the chlorinated copper phthalocyanine pigment obtained in Reference Example 2 (average number of introduced chlorines: 15.60) was used.

Reference Example 19
(Preparation of green pigment dispersion 3)
A green pigment dispersion 3 was obtained in the same manner as in Reference Example 17 except that 100 g of a chlorinated copper phthalocyanine pigment (manufactured by Clariant, “Hosta Palm Green”, (trade name) GNX) was used.
The average number of introduced chlorines of Hosta Palm Green GNX, which is a commercially available copper chloride phthalocyanine pigment, was 15.03.
Reference Example 20
(Preparation of green pigment dispersion 4)
A green pigment dispersion 4 was obtained in the same manner as in Reference Example 17 except that 100 g of brominated copper phthalocyanine pigment (manufactured by DIC Corporation, “First Gen Green”, (trade name) 2FK-CF) was used. .
Reference Example 21
(Preparation of green pigment dispersion 5)
A green pigment dispersion 5 was obtained in the same manner as in Reference Example 17 except that 100 g of brominated zinc phthalocyanine pigment (manufactured by DIC Corporation, “First Gen Green”, (trade name) A110) was used.
Reference Example 22
(Preparation of blue pigment dispersion 1)
A blue pigment dispersion 1 was obtained in the same manner as in Reference Example 17 except that 80 g of PB15: 6 and 20 g of PV23 were used.
Reference Example 23
(Preparation of red pigment dispersion 1)
A red pigment dispersion 1 was obtained in the same manner as in Reference Example 17 except that 60 g of PR254 and 40 g of PR177 were used.

  Table 1 shows the evaluation results of the yellow pigment dispersions 1 to 8 and the green pigment dispersions 1 to 5 obtained in Reference Examples 9 to 21.

  Since Yellow Pigment Dispersion 1 contains a copper azomethine pigment and a copper phthalocyanine pigment derivative, both the viscosity and yield value of the pigment dispersion were low, and the pigment dispersion stability was good. On the other hand, since the yellow pigment dispersion 2 and the yellow pigment dispersion 3 do not contain a copper phthalocyanine pigment derivative, both the viscosity and the yield value of the pigment dispersion are increased, resulting in poor dispersion stability of the pigment.

  Yellow Pigment Dispersion Liquid 1 and Yellow Pigment Dispersion Liquids 5 to 8 are obtained by changing the average sulfonic acid introduction number of the copper phthalocyanine pigment derivative. The yellow pigment dispersion 1, the yellow pigment dispersion 6, and the yellow pigment dispersion 7 both had particularly low viscosity and yield values, and the dispersion stability of the copper azomethine pigment was improved.

In addition, the yellow pigment dispersion 4 and the green pigment dispersions 1 to 5 are pigment dispersions using various pigments, and both of the viscosity and the yield value are low, and the dispersion stability is good.
Example 1
(Preparation of green colorant composition)
2. 37.2 g of yellow pigment dispersion 1 obtained in Reference Example 9, 37.2 g of green pigment dispersion 1 obtained in Reference Example 17, 0.7 g of cyclomer ACA250 (45 wt% solution), 4 g of Nippon Kayaku polyfunctional monomer “Kayarad” DPHA, 0.4 g of Ciba Specialty Chemicals photoinitiator “Irgacure” 907, 0.2 g of Nippon Kayaku sensitizer “Kayacure” DETX-S, and After adding 20.9 g of propylene glycol monomethyl ether acetate, a surfactant “BYK333” manufactured by bic chemie was added to a total solid content of 2000 ppm to obtain a photosensitive green colorant composition.
The weight mixing ratio of the pigment component and the resin component in the green colorant composition is pigment component: resin component = 50: 50, and the weight mixing ratio of the pigment is chlorinated copper phthalocyanine pigment: copper azomethine pigment = 50. : 50.
(Production of color filter substrate)
The photosensitive green colorant composition obtained on the transparent glass substrate was applied with a spinner, and then heat-treated in a hot air oven at 90 ° C. for 10 minutes to obtain a green colored film. Next, a predetermined area is exposed through a negative mask, and “Emulgen” A-60 (HLB12.8, polyoxyethylene derivative) as a nonionic surfactant is added to a 0.04% aqueous potassium hydroxide solution (manufactured by Kao Corporation). ) Was developed by immersing with an alkali developer added at 0.1% by mass with respect to the total amount of the developer for 90 seconds, followed by washing with pure water to obtain a patterned substrate. The obtained patterned substrate was held in a hot air oven at 220 ° C. for 30 minutes to cure the acrylic resin. Thus, a color filter substrate having green pixels was produced.
The spinner rotation speed of the green colorant composition was adjusted, and coating was performed so that the chromaticity of the green pixel after curing was y = 0.650 with a C light source. Table 2 shows various evaluation results of the green colorant composition and the color filter substrate obtained in Example 1.

Examples 2-12, Comparative Examples 1-3
(Green colorant composition and color filter substrate production)
Using the green pigment dispersion and yellow pigment dispersion shown in Table 2, a green colorant composition and a color filter substrate were prepared in the same manner as in Example 1 except that the pigment ratios shown in Table 2 were used. . Various evaluation results are shown in Table 2.
In Example 1, since the yellow pigment dispersion 1 containing a copper azomethine pigment and a copper phthalocyanine pigment derivative was used, an ultrahigh contrast ratio (contrast ratio 8800) and an ultrahigh color purity (film thickness 1.58 μm) were obtained. Good results were obtained. On the other hand, since Comparative Example 1 and Comparative Example 2 used a yellow pigment dispersion that did not contain a copper phthalocyanine pigment derivative, the dispersion stability of the green colorant composition was poor, and the contrast ratio of the color filter was low. The result was bad. Moreover, since the comparative example 3 used the yellow pigment dispersion liquid 4 which does not contain a copper azomethine pigment, color purification was low and the result was unsatisfactory.

  In Examples 1 and 6 to 8, copper azomethine pigments and PY150 were used as yellow pigments, chlorinated copper phthalocyanine pigments were used as green pigments, and the weight mixing ratio of these pigments was changed. The contrast ratio was high in all of Examples 1 and 6 to 8, the color purity was high in Examples 1, 6, and 7, and the luminance was high in Examples 6, 7, and 8. That is, in Examples 6 and 7, since the weight mixing ratio of the copper azomethine pigment and PY150 was optimized, the contrast ratio, color purity, and luminance were favorable.

  In Examples 6, 9, and 10, the copper azomethine pigment, PY150 was used as the yellow pigment, the chlorinated copper phthalocyanine pigment was used as the green pigment, and the chlorination introduction number of the chlorinated copper phthalocyanine pigment was changed. is there. The contrast ratio was high in all of Examples 6, 9, and 10, the color purity was high in Example 6, and the luminance was high in Example 6. That is, the greater the number of chlorine introduced in the chlorinated copper phthalocyanine pigment, the higher the color purity and brightness.

Example 12 is a result of using a copper azomethine pigment and PY150 as a yellow pigment, and using a chlorinated copper phthalocyanine pigment and a brominated zinc phthalocyanine pigment as a green pigment. Although Example 12 compared with Example 6, the film thickness was thick, but the brightness | luminance became a high value. That is, when a brominated zinc phthalocyanine pigment was used as the green pigment, the color purity was slightly reduced, but the luminance was improved.
Example 13
(Blue colorant composition, red colorant composition production)
A blue colorant composition was prepared in the same manner as in Example 1 except that 74 g of the blue pigment dispersion 1 obtained in Reference Example 22 was used. The weight mixing ratio of the pigment component and the resin component in the blue colorant composition was pigment component: resin component = 50: 50, and the weight mixing ratio of the pigment was PB15: 6: PV23 = 80: 20.

A red colorant composition was prepared in the same manner as in Example 1 except that 74 g of the red pigment dispersion liquid 1 obtained in Reference Example 23 was used. The weight mixing ratio of the pigment component and the resin component in the red colorant composition was pigment component: resin component = 50: 50, and the weight mixing ratio of the pigment was PR254: PR177 = 60: 40.
(Color filter production)
Using the green colorant composition obtained in Example 1 on the glass substrate on which the black matrix was produced, green pixels were produced in the same manner as in Example 1. Next, a blue pixel and a red pixel were produced in the same manner using the blue colorant composition and the red colorant composition obtained in Example 13. Thereafter, a transparent electrode was formed to obtain a color filter substrate having green pixels, blue pixels, and red pixels. In addition, the spinner rotation speed of each colorant composition was adjusted so that the film thickness of each pixel after color filter curing was 2.0 μm.
(Production of liquid crystal display device)
An array substrate was produced by forming TFT elements, transparent electrodes, etc. on alkali-free glass. A polyimide alignment film was formed on the color filter substrate and the TFT substrate and rubbed. A sealant kneaded with microrods was printed on the array substrate, and a bead spacer having a thickness of 6 μm was sprayed thereon, and then the array substrate and the color filter substrate were bonded together. After injecting nematic liquid crystal (“Rixon” JC-5007LA made by Chisso) from the injection port provided in the seal part, a polarizing film was laminated on both surfaces of the liquid crystal cell so that the polarization axes were perpendicular to obtain a liquid crystal panel. A white LED obtained by coating a blue LED with a YAG phosphor was attached to this liquid crystal panel, and a TAB module, a printed circuit board, and the like were mounted to produce a liquid crystal display device.

When the contrast ratio was measured from the luminance ratio between white display and black display of this liquid crystal display device, the contrast ratio was 2500, and a good result was obtained. Further, the color reproduction range of this liquid crystal display device was 96% as compared with the NTSC standard, which was good.
That is, since the green pixel of the color filter substrate has ultra high color purity and ultra high contrast, this liquid crystal display device has a very wide color reproduction range and good display quality.
Comparative Example 4
(Production of color filter substrate and liquid crystal display device)
A color filter substrate and a liquid crystal display device were produced in the same manner as in Example 13 except that the green colorant composition obtained in Comparative Example 1 was used.

The contrast ratio of this liquid crystal display device was 600. The color reproduction range of this liquid crystal display device was 92% as compared with the NTSC standard.
That is, since the contrast ratio of the green pixel of the color filter is low, the display quality of this liquid crystal display device is poor.
Comparative Example 5
(Production of color filter substrate and liquid crystal display device)
A color filter substrate and a liquid crystal display device were produced in the same manner as in Example 13 except that the green colorant composition obtained in Comparative Example 3 was used.

The contrast ratio of this liquid crystal display device was 2500. The color reproduction range of this liquid crystal display device was 84% as compared with the NTSC standard.
That is, since the color purity of the green pixel of the color filter is low, the display color reproduction range of this liquid crystal display device is not so wide.

  The green colorant composition for color filters of the present invention can be suitably used for a green colorant composition for color filters used in liquid crystal displays and the like.

Claims (7)

In a green colorant composition for a color filter containing at least a resin, a solvent, a pigment dispersant, a green pigment and a yellow pigment, a copper azomethine pigment is contained as a yellow pigment, and a copper phthalocyanine pigment is sulfonic acid as a pigment dispersant. A green colorant composition for color filters, comprising a copper phthalocyanine pigment derivative having a group introduced therein. The green colorant composition for a color filter according to claim 1, wherein the average number of introduced sulfonic acid groups per molecule of the copper phthalocyanine pigment derivative is 1.8 to 2.1. Copper azomethine pigments are C.I. I. Pigment Yellow 129, and C.I. I. The green colorant composition for a color filter according to claim 1, comprising Pigment Yellow 150. A chlorinated copper phthalocyanine pigment is contained as a green pigment, and the average number of introduced chlorine atoms per molecule of chlorinated copper phthalocyanine of the chlorinated copper phthalocyanine pigment is 15.1-16.0. The green colorant composition for a color filter according to any one of claims 1 to 3. The green colorant composition for a color filter according to any one of claims 1 to 4, further comprising a zinc phthalocyanine pigment as a green pigment. A color filter substrate in which pixels made of a colored film provided in a desired pattern for each color with an arbitrary number of colors on a transparent substrate, the colored film according to any one of claims 1 to 5. A color filter substrate formed of a green colorant composition for a color filter. A liquid crystal display device comprising the color filter substrate according to claim 6.