JP2016080966A - Color filter and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter and a liquid crystal display device that are high in color reproduction and lightness.SOLUTION: A liquid crystal display device comprises a backlight provided with a white LED device having a combination of a blue LED, a red light-emitting phosphor, and a green light-emitting phosphor having a peak wavelength of emission intensity in the wavelength range of 430 to 470 nm, 520 to 530 nm, and 610 to 670 nm, respectively. A color filter is used for the display, and comprises, on a transparent substrate, coloring pixels of a plurality of colors containing a green pixel, with the green pixel containing an aluminum phthalocyanine pigment, pigment green 58, and pigment yellow 138.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a color filter excellent in color reproducibility.

  Color liquid crystal display devices are rapidly spreading mainly in computer terminal display devices and television image display devices. As required characteristics for liquid crystal display devices, high color reproducibility and high brightness are strongly demanded.

High color reproducibility and high brightness are characteristics that depend on the backlight light source and color filter used in the liquid crystal display device.
A cold cathode fluorescent tube (CCFL), which is a conventional backlight source, has a problem in that color purity is deteriorated due to a sub-peak of the phosphor with respect to color reproducibility. To solve this problem, it is possible to suppress the sub-peak by using a high-purity phosphor and to improve the decrease in color purity, but there is a problem that the issue efficiency deteriorates, and high color reproduction while maintaining lightness occurs. It was difficult to make it.

  On the other hand, the trend of replacing the backlight light source with a white LED light source that is mercury-free and consumes less power is becoming mainstream due to increasing awareness of environmental problems. Therefore, in order to realize high color reproduction, a method of using red, green, and blue three-color LED (light emitting diode) light sources without sub-peaks as a backlight is used (for example, see Patent Document 1). However, when an RGB three-color LED light source is used as a backlight for a liquid crystal display device, the individual variations of the LEDs are large, which complicates the drive device for the control, and differences in the efficiency of each color. Because of the adjustment, there is a disadvantage of high cost. For this reason, there are many problems in mass production due to the recent price drop of liquid crystal display devices.

  Therefore, in recent years, white LEDs (dual-wavelength LEDs) in which light emitted from blue LEDs is mixed through a phosphor such as YAG (yttrium, aluminum, garnet) are widely used in mobile-related small liquid crystal display devices. However, when a two-wavelength LED is used for the backlight, there is a problem that the color reproducibility of the green display of the liquid crystal display device is remarkably deteriorated because the emission peak exists in the yellow region.

  On the other hand, a white LED (three-wavelength LED) device having a light emission characteristic shown in FIG. 1 and a color mixture of a blue LED and a red / green light emitting phosphor is a mixture of two phosphors and emits light. Since the peak is a three-wavelength light source having no sub-peak, color reproducibility can be improved. Since the backlight unit of this three-wavelength LED device uses only one kind of blue LED having a large solid difference, the cost merit is high, and therefore a liquid crystal display device can be provided at low cost.

  Although the color reproducibility can be improved by using the three-wavelength LED for the backlight, the conventional color filter can satisfy the color reproducibility for green, but there is a problem that the lightness is remarkably lowered. It was.

  In order to improve the green color reproducibility by the color filter, it is necessary to increase the thickness of the pixel. However, when only a general color material such as pigment green 36 or 58 is used, the thickness of the green pixel is reduced. There is a problem that the film becomes thick beyond the practical level. In particular, in recent years, as pixels become finer, light incident from an oblique direction passes through other adjacent pixels and enters the photoelectric conversion element, resulting in a problem of color mixing.

  In order to solve this problem, for example, Patent Document 1 discloses C.I. I. Pigment green 7, C.I. I. Proposals have been made to form green pixels using a green photosensitive resin composition containing CI Pigment Yellow 185. However, when Pigment Green 7 and Pigment Yellow 185 are used, there is a problem that although the high color reproducibility can be achieved, the brightness becomes extremely low.

  Patent Documents 2 and 3 propose the formation of green pixels having high color reproducibility without increasing the pigment concentration by using a photosensitive resin composition in which a blue pigment and a yellow pigment are mixed. As C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 16 and C.I. I. Pigment Blue 76 is C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 139 and C.I. I. Pigment yellow 150 is illustrated. However, the above-mentioned patent has a problem that the brightness is generally low because a considerable amount of blue pigment is used for thinning.

  In Patent Document 4, the aluminum phthalocyanine pigment used in the present invention is used as a green pigment, PY138, 150 is used as a yellow pigment, and attempts are made to achieve high color reproducibility and high brightness. Even when an LED is used and an aluminum phthalocyanine pigment is used, the combination of the light source and the spectrum is poor and it is insufficient to make use of the original brightness of the color material.

  As described above, although high color reproducibility can be satisfied, it is difficult to achieve high brightness.

JP 2003-238898 A JP 2004-176000 A Japanese Patent Laid-Open No. 2004-212851 JP2013-156597A

  The present invention solves the above problems, and has high color reproducibility by selecting the peak wavelength of the emission intensity of the green light emitting phosphor used in the three-wavelength LED and optimizing the color material used in the green pixel. An object of the present invention is to provide a liquid crystal display device and a color filter that enable bright green display.

  In order to solve the above problems, a first embodiment of the present invention is a blue LED and a red light emitting phosphor having emission intensity peak wavelengths in a wavelength range of 430 nm to 470 nm, 520 nm to 530 nm, and 610 nm to 670 nm. And a color filter having a plurality of colored pixels including a green pixel on a transparent substrate, which is used in a liquid crystal display device including a backlight having a white LED device combined with a green light emitting phosphor. The color filter includes an aluminum phthalocyanine pigment, pigment green 58, and pigment yellow 138 in a pixel.

In the second embodiment of the present invention, the display chromaticity measured by the backlight using the white LED element as a light source is x = 0.210 ± 0.010, y = 0.710 ± 0. The color filter according to claim 1, further comprising a green pixel having a brightness of 42.5 or more in a range of 010.

According to a third aspect of the present invention, there is provided a liquid crystal display device comprising the color filter according to the first or second aspect.

  According to the present invention, by using a three-wavelength LED selected for the peak wavelength of the emission intensity of the green light emitting phosphor for the backlight, and using the color filter of the present invention having a green reproducibility suitable for the green light emitting phosphor, A liquid crystal display device having high color reproducibility and capable of bright green display can be obtained.

It is the schematic which shows the light emission characteristic of white LED (three wavelength LED) which mixed the blue LED and red / green light emission fluorescent substance which concern on one embodiment of this invention by the color combination. It is a schematic sectional drawing which shows the color filter which concerns on embodiment of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display device provided with the color filter of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

(White LED)
A white LED that can be used in the present invention will be described.

  As a white LED, a two-wavelength LED and a three-wavelength LED are given as typical pseudo-white LEDs.

  The two-wavelength LED is obtained by mixing the light emitted from a blue LED through a phosphor such as YAG (yttrium, aluminum, garnet) and mixing the colors, and the peak of the emission intensity derived from the blue LED in the wavelength range of 430 nm to 470 nm. It has a wavelength and has a peak wavelength of emission intensity derived from the yellow phosphor in a wavelength range of 520 nm to 570 nm.

  On the other hand, in the three-wavelength LED, part of the blue light emitted by the blue LED is transmitted through the phosphor layer, and the rest is absorbed by the green phosphor and the red phosphor, and converted into green and red light, respectively. . It has a peak wavelength of emission intensity derived from blue LED in a wavelength range of 430 nm to 470 nm, and has a peak wavelength of emission intensity derived from green phosphor and red phosphor in wavelength ranges of 520 nm to 570 nm and 610 nm to 670 nm. Features. In particular, the emission peak wavelength of the green phosphor is in the range of 520 nm to 530 nm is important for high color reproduction and high brightness of the green pixel.

  Since the two-wavelength LED is low in cost and excellent in luminous efficiency, it is widely used as a backlight light source for liquid crystal display devices and the like used for mobile phone displays. On the other hand, the three-wavelength LED is inferior in terms of cost and light emission efficiency as compared with the two-wavelength LED, but is used as a backlight light source for applications where it is important to achieve both high color reproduction and transmittance.

(Color filter)
The color filter of the present invention is used in a liquid crystal display device having a backlight using the white LED as a light source, and the green pixel of the color filter is an aluminum phthalocyanine pigment,
It is formed using a green photosensitive resin composition containing two types of pigments, yellow pigments. Hereinafter, two types of pigments used for forming the green pixel will be described.

  The aluminum phthalocyanine pigment used for forming the green pixel of the color filter of the present invention is a bluish green having a high transmittance around 500 nm and a low transmittance below 470 nm compared to pigment green 58, and has a strong coloring power There is. When the three-wavelength LED in the present invention is used as a light source, it is a color material effective in increasing color purity and brightness.

  For the green pixel, for example, a green pigment such as pigment green 7, 10, 36, 37, 58 or the like can be used. In particular, a green pigment is important because a brominated zinc phthalocyanine pigment represented by Pigment Green 58 is effective as a high transmittance and dispersion stabilizer for an aluminum phthalocyanine pigment.

  The yellow pigment used for green pixel formation of the color filter of the present invention is, for example, pigment yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 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, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 1 Or the like can be used 3,174,175,176,177,179,180,181,182,185,187,188,193,194,198,199,213,214. Among these, it is important to use Pigment Yellow 138 from the viewpoint of increasing brightness.

  In order to achieve high color reproducibility and high brightness, the pigment is preferably finely processed and preferably has a large specific surface area.

  As a means for controlling the specific surface area of the pigment, a method of controlling the specific surface area by mechanically pulverizing the pigment (referred to as a grinding method), a solution dissolved in a good solvent is introduced into a poor solvent, and a desired specific surface area of the pigment is controlled. There are a method for precipitating a pigment (referred to as a precipitation method), a method for producing a pigment having a desired specific surface area during synthesis (referred to as a synthetic precipitation method), and the like. Depending on the synthesis method and chemical properties of the pigment to be used, an appropriate method can be selected for each pigment.

  Each method will be described below, but any of the above methods may be used as a method for controlling the specific surface area of various pigments used in the present invention.

  In the grinding method, the pigment is mechanically kneaded with a grinding agent such as a water-soluble inorganic salt such as sodium chloride and a water-soluble organic solvent that does not dissolve it using a ball mill, a sand mill, or a kneader (hereinafter, this step is referred to as this step). This method is called salt milling), and then the inorganic salt and the organic solvent are washed away with water and dried to obtain a pigment having a desired specific surface area. However, since the pigment may crystallize by the salt milling treatment, a method of preventing crystal growth by adding a solid resin or a pigment dispersant that is at least partially dissolved in the organic solvent during the treatment is effective.

  As for the ratio of the pigment to the inorganic salt, if the ratio of the inorganic salt is increased, the efficiency of refining the pigment is improved, but the productivity is lowered because the amount of pigment processed is reduced. In general, 1 to 30 parts by weight, preferably 2 to 20 parts by weight of the inorganic salt is used per 1 part by weight of the pigment. Further, the water-soluble organic solvent is added so that the pigment and the inorganic salt are uniformly solidified, and depending on the blending ratio of the pigment and the inorganic salt, the amount of the pigment is usually 50 to 300% by weight. Used.

  More specifically, the salt milling is performed by adding a small amount of a water-soluble organic solvent as a wetting agent to a mixture of a pigment and a water-soluble inorganic salt, kneading with a kneader or the like, and then pouring the mixture into water. Stir with a speed mixer or the like to form a slurry. Next, this slurry is filtered, washed with water, and dried to obtain a pigment having a desired specific surface area.

  The precipitation method is a method in which a pigment is dissolved in an appropriate good solvent and then mixed with a poor solvent to precipitate a pigment having a desired specific surface area. The specific surface area depends on the type and amount of the solvent, the precipitation temperature, the precipitation rate, etc. The size of can be controlled. In general, pigments are difficult to dissolve in solvents, so the solvents that can be used are limited. Examples include strongly acidic solvents such as concentrated sulfuric acid, polyphosphoric acid, and chlorosulfonic acid, or basic solvents such as liquid ammonia, dimethylformamide solution of sodium methylate, etc. It has been known.

  A typical example of this method is an acid pasting method in which a solution in which a pigment is dissolved in an acidic solvent is poured into another solvent and reprecipitated to obtain fine particles. Industrially, a method of injecting a sulfuric acid solution into water is generally used from the viewpoint of cost. The sulfuric acid concentration is not particularly limited, but is preferably 95 to 100% by weight. The amount of sulfuric acid used with respect to the pigment is not particularly limited. However, if the amount is too small, the solution viscosity is high and the handling is poor. It is preferable. The pigment need not be completely dissolved. The temperature at the time of dissolution is preferably from 0 to 50 ° C. Below this temperature, sulfuric acid may freeze and the solubility will be low. If the temperature is too high, side reactions tend to occur. The temperature of the water to be injected is preferably 1 to 60 ° C., and if the injection is started at a temperature higher than this temperature, it boils with the heat of dissolution of sulfuric acid, and the operation is dangerous. It will freeze at temperatures below this. The injection time is preferably 0.1 to 30 minutes with respect to 1 part of the pigment. As the time increases, the specific surface area tends to decrease.

  The specific surface area of the pigment can be controlled while considering the fine particle size of the pigment by selecting a method that combines a precipitation method such as the acid pasting method and a grinding method such as the salt milling method. At this time, it is more preferable because fluidity as a dispersion can be secured.

  At the time of salt milling or acid pasting, in order to prevent the aggregation of the pigment accompanying the specific surface area control, the following dispersion aids such as pigment derivatives, resin-type pigment dispersants and surfactants can be used in combination. Further, by controlling the specific surface area in the form of coexisting two or more kinds of pigments, even a pigment that is difficult to disperse alone can be finished as a stable dispersion.

  There is a leuco method as a special precipitation method. When vat dyes such as flavantron, perinone, perylene, and indanthrone are reduced with alkaline hydrosulfite, the quinone group becomes hydroquinone sodium salt (leuco compound) and becomes water-soluble. A pigment having a large specific surface area that is insoluble in water can be precipitated by adding an appropriate oxidizing agent to the aqueous solution for oxidation.

  The synthetic precipitation method is a method in which a pigment having a desired specific surface area is deposited simultaneously with the synthesis of the pigment. However, when the produced fine pigment is taken out of the solvent, if the pigment particles are not aggregated into large secondary particles, filtration, which is a general separation method, becomes difficult. It is applied to azo pigments synthesized in water.

Furthermore, as a means of controlling the specific surface area of the pigment, the pigment can be dispersed at the same time as increasing the specific surface area of the pigment by dispersing the pigment for a long time with a high-speed sand mill or the like (so-called dry milling method in which the pigment is dry pulverized). Is possible.

  The two kinds of pigments forming the green pixel of the color filter of the present invention are prepared as a pigment dispersion liquid that has been subjected to the treatment for increasing the specific surface area as described above and dispersed in a transparent resin and a solvent. The pigment dispersion can be produced by finely dispersing the pigment in a transparent resin and a solvent using various dispersing means such as a three roll mill, a two roll mill, a sand mill, a kneader, and an attritor. In the dispersion, a dispersion aid such as a resin-type pigment dispersant, a surfactant, or a pigment derivative can be contained. Since the dispersion aid is excellent in pigment dispersion and has a large effect of preventing re-aggregation of the pigment after dispersion, a pigment dispersion obtained by dispersing the pigment in a transparent resin and a solvent using the dispersion aid was used. In this case, a color filter having excellent transparency can be obtained.

  The transparent resin 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, and these can be used alone or in admixture of two or more. The transparent resin can be used in an amount of 30 to 700 parts by weight, preferably 60 to 450 parts by weight, based on 100 parts by weight of the pigment in the pigment dispersion.

  Examples of the thermoplastic resin include acrylic resin, butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane series. Examples thereof include resins, polyester resins, vinyl resins, alkyd resins, polystyrenes, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

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

  Examples of the solvent include 1,2,3-trichloropropane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, 1,4-dioxane, 2-heptanone, and 2-methyl. -1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-methyl -1,3-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m -Diethylbenzene, m-dichlorobenzene, N, N-dimethylacetamide, N, N-dimethylformamide, n-butyl alcohol, n-butylbenzene, n-propylacetate , N-methylpyrrolidone, o-xylene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene, γ-butyrolactone, isobutyl Alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate , Ethylene glycol monopropyl ether, ethylene glycol monohexyl ether, Ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, cyclohexanol, cyclohexanol Acetate, cyclohexanone, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol Monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate , Propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, benzyl alcohol, methyl isobutyl ketone, methylcyclohexanol, n-amyl acetate, Acid n- butyl, isoamyl acetate, isobutyl acetate, propyl acetate, dibasic esters, and the like, used alone or in combination.

  The dispersion aid can be used in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the pigment in the pigment dispersion.

  The resin-type pigment dispersant has a pigment-affinity part that has the property of adsorbing to the pigment and a part that is compatible with the dye carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the dye carrier. It works. Specific examples of resin-type pigment dispersants include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamines. Salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) with polyesters having free carboxyl groups, and the like Water-based dispersants such as oily dispersants such as salts, (meth) acrylic acid-styrene copolymers, (meth) acrylic acid- (meth) acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone Resin, water-soluble polymer, polyester Modified polyacrylate, ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, they can be used alone or in admixture of two or more.

  Commercially available resin-type pigment dispersants include Disperbyk-101, 103, 107, 108, 110, 111, 116, 130, 140, 154, 161, 162, 163, 164, 165, 166, 170, manufactured by Big Chemie. 171, 174, 180, 181, 182, 183, 184, 185, 190, 2000, 2001, or Anti-Terra-U, 203, 204, or BYK-P104, P104S, 220S, or Lactimon, Lactimon-WS, or Bykumen SOLSPERSE-3000, 9000, 13240, 13650, 13940, 17000, 18000, 20000, 21000, 24000, 26000, 27000, 28000, 31845, 32, manufactured by Nippon Lubrizol Co., Ltd. 00, 32500, 32600, 34750, 36600, 38500, 41000, 41090, 53095, etc., EFKA-46, 47, 48, 452, LP4008, 4009, LP4010, LP4050, LP4055, 400, 401, 402 manufactured by Efka Chemicals , 403, 450, 451, 453, 4540, 4550, LP4560, 120, 150, 1501, 1502, 1503, and the like.

  Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and these can be used alone or in admixture of two or more.

(Green photosensitive resin composition)
The green photosensitive resin composition used for green pixel formation of the color filter of the present invention comprises at least the pigment dispersion, a photopolymerizable monomer, a photopolymerization initiator, and a solvent.

  Examples of the photopolymerizable monomer include pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, and propylene oxide modified trimethylolpropane tri (meth) acrylate. Various acrylic acid esters, methacrylic acid esters and the like are listed as representative examples. The photopolymerizable monomer preferably has 4 to 12 ethylenically unsaturated double bonds from the viewpoint of increasing the sensitivity of the photosensitive resin composition. In the photosensitive resin composition containing the polyfunctional monomer which has 3 or less ethylenically unsaturated double bonds, desired sensitivity cannot be obtained. The photopolymerizable monomers can be used alone or in admixture of two or more.

The content of the photopolymerizable monomer is preferably 10 to 300 parts by weight, more preferably 10 to 200 parts by weight with respect to 100 parts by weight of the pigment.
Examples of the photopolymerization initiator include oxime ester photopolymerization initiators, α-aminoalkylphenone photopolymerization initiators, carbazole photopolymerization initiators, and acylphosphine oxide photopolymerization initiators.

  Particularly preferred oxime ester photoinitiators include ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (0-acetyloxime), 1 , 2-octadion-1- [4- (phenylthio)-, 2- (O-benzoyloxime)].

  Particularly preferred acylphosphine oxide photopolymerization initiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

Particularly preferable α-aminoalkylacetophenone photopolymerization initiators include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- ( 4-morpholinophenyl) -butane-1,2- (dimethylamino) -2-[(4-methylthiophenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone.

  Particularly preferable carbazole-based photopolymerization initiators include 3,6-bis (2-methyl-2-morpholinopropionyl) -9-methylcarbazole and 3,6-bis (2-methyl-2-morpholinopropionyl) -9-. Benzoylcarbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n-butylcarbazole, 3,6-bis (2-methyl-2-morpholinopropionyl) -9-n-octylcarbazole, 3 , 6-bis (2-methyl-2-morpholinopropionyl) -9-n-dodecylcarbazole.

  These photoinitiators can be used individually by 1 type or in mixture of 2 or more types. Content of a photoinitiator can be used in the amount of 5-200 weight part with respect to 100 weight part of pigments, Preferably it is 10-150 weight part.

  The green photosensitive resin composition according to the present invention basically does not require a sensitizer, but may be used in combination with a photopolymerization initiator. These sensitizers can be used individually by 1 type or in mixture of 2 or more types. The content of the sensitizer is preferably 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

  In addition, the green photosensitive resin composition of the present invention can further contain a polyfunctional thiol that functions as a chain transfer agent.

  The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap To-s-triazine, 2- (N, N-dibutylamino) -4,6-dimercapto-s-triazine and the like can be mentioned. These polyfunctional thiols can be used alone or in combination.

  The content of the polyfunctional thiol is preferably 0.05 to 100 parts by weight, more preferably 0.1 to 60 parts by weight with respect to 100 parts by weight of the pigment.

  Furthermore, the green photosensitive resin composition can be used by appropriately adding the solvent in order to adjust the coatability.

  The green photosensitive resin composition of the present invention can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Moreover, in order to improve adhesiveness with a transparent substrate, adhesion improving agents, such as a silane coupling agent, can also be contained. The storage stabilizer can be used in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pigment in the photosensitive resin composition.

  Examples of storage stabilizers include hydroquinone, such as hydroquinone, methyl hydroquinone, 2,5 di-tert-butyl hydroquinone, tert-butyl hydroquinone, tert-butyl-β benzoquinone, tert-butyl hydroquinone 2,5 diphenyl-p-benzoquinone. Compounds, quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and phosphines such as methyl ether, tributylphosphine, trioctylphosphine, tricyclohexylphosphine, triphenylphosphine and tribenzylphosphine Compounds, phosphine oxide compounds such as trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphite, trisnonylphosphine Examples thereof include phosphite compounds such as phenyl phosphite and t-butylpyrocatechol. The storage stabilizer can be used in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pigment in the green photosensitive resin composition.

  Examples of the silane coupling agent include vinyl silanes such as vinyltris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane, (meth) acrylsilanes such as γ-methacryloxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ) Epoxysilanes such as methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopro Lutriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N Examples include aminosilanes such as -phenyl-γ-aminopropyltriethoxysilane, thiosilanes such as γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane. The silane coupling agent can be used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, with respect to 100 parts by weight of the pigment in the color filter coloring composition.

  The pigment is preferably contained in a proportion of 5 to 70% by weight based on the total solid content in the green photosensitive resin composition (100% by weight). More preferably, the proportion is 20 to 50% by weight.

  The green photosensitive resin composition is mixed with coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably 0.5 μm or more, and coarse particles by means of centrifugation, sintered filter, membrane filter or the like. It is preferable to remove dust.

  The color filter of the present invention is manufactured by forming each colored pixel on a transparent substrate on which a black matrix is formed by a photolithography method using the green photosensitive resin composition and the red and blue photosensitive resin compositions. can do. Here, the red and blue photosensitive resin compositions can be produced in the same manner as in the case of the green photosensitive resin composition using a conventionally known color material.

  Examples of the red photosensitive resin composition include C.I. I. Pigment Red 7, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 184, Red pigments such as 185, 187, 200, 202, 208, 210242, 246, 254, 255, 264, 270, 272, and 279 are used. The red photosensitive resin composition includes C.I. I. Pigment Orange 43, 71, 73 and the like, and C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 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, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, It can be used in combination with the yellow pigments such as 82,185,187,188,193,194,198,199,213,214.

  Examples of the blue photosensitive resin composition include C.I. I. Blue pigments such as CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64 are used. The blue photosensitive resin composition includes C.I. I. Purple violet pigments such as CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, and 50 can be used in combination.

  As transparent substrates, known transparent substrate materials such as glass substrates such as soda lime glass, low alkali borosilicate glass, non-alkali aluminoborosilicate glass, resin substrates such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate, quartz substrates, etc. Among them, a glass substrate that is excellent in transparency, strength, heat resistance, and weather resistance is preferable. Further, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the transparent substrate for driving the liquid crystal after the liquid crystal panel is formed.

  In the coating process of the photosensitive resin composition by a photolithography method, the coating is performed by a known coating method such as spray coating, spin coating, slit coating, or roll coating. For drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used.

  Next, the pattern is cured by irradiating ultraviolet rays or an electron beam from the upper surface of the dried coating film through a mask having a predetermined pattern provided in contact or non-contact with the film by a conventionally known exposure method. The light or radiation to be irradiated is not particularly limited as long as the photosensitive resin composition has an absorption wavelength for curing, but ultraviolet rays or electron beams are particularly preferable. In particular, an ultraviolet irradiation treatment with an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp or the like is preferable. Further, it is desirable that unnecessary wavelengths are cut through a corresponding filter.

  Thereafter, the unexposed portion of the photosensitive resin composition is removed by a conventionally known developing method to form a black matrix and colored pixels. In removing the unexposed portion, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied.

  In the present embodiment, after the black matrix and the colored pixels are formed, a step of performing heat treatment and thermosetting can be provided. As a heating method, a convection oven, a hot plate, a halogen heater, heating by an IR oven, or the like can be used, and is not particularly limited. Here, it is preferable that baking conditions are 200-250 degreeC, and are heated for 10 minutes-60 minutes.

Specific examples of the present invention will be described below. In addition, this invention is not limited to a following example in the range which does not exceed the summary.
A method for adjusting various pigment dispersions used in Examples and Comparative Examples will be described below.

[Preparation of alkaline resin solution]
The acrylic resin solutions used in Examples and Comparative Examples were prepared as follows. The molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

After stirring and mixing a mixture having the following composition with a disper, using a zirconia bead having a diameter of 0.5 mm, it is dispersed for 4 hours using an Eiger mill (“Mini Model M-250 MKII” manufactured by Eiger Japan) as a media type wet disperser. After that, a pigment content of 50% and a solid content of 20% were prepared to obtain a green pigment dispersion PG-1.
[Preparation of Green Pigment Dispersion Composition PG-1]
Aluminum phthalocyanine pigment 8.5 parts pigment derivative 1 1.5 parts alkaline resin solution 50.0 parts propylene glycol monomethyl ether acetate 40.0 parts pigment derivative 1: Copper phthalocyanine pigment derivative shown below.
Equation _{(12) CuPc-SO 3 H} · (CH 3) 2 N (C 18 H 37) 2
(Wherein CuPc is a copper phthalocyanine pigment residue).

[Preparation of Green Pigment Dispersion Composition PG-2]
After stirring and mixing a mixture having the following composition with a disper, using a zirconia bead having a diameter of 0.5 mm, it is dispersed for 4 hours using an Eiger mill (“Mini Model M-250 MKII” manufactured by Eiger Japan) as a media type wet disperser. After that, a pigment content of 50% and a solid content of 20% were prepared to obtain a green pigment dispersion PG-2.
Pigment Green 58 (PG58) 14.0 parts "Phthalocyanine Green A110" manufactured by DIC Corporation
Alkaline resin solution 25.2 parts Propylene glycol monomethyl ether acetate 60.8 parts Pigment derivative 2: Pigment derivatives shown below.

[Preparation of Green Pigment Dispersion Composition PG-3]
After stirring and mixing a mixture having the following composition with a disper, using a zirconia bead having a diameter of 0.5 mm, it is dispersed for 4 hours using an Eiger mill (“Mini Model M-250 MKII” manufactured by Eiger Japan) as a media type wet disperser. After that, a pigment content of 50% and a solid content of 20% were prepared to obtain a green pigment dispersion PG-3.
Pigment Green 7 (PG7) 14.0 parts “LIONOL GREEN YS-7” manufactured by Toyocolor Co., Ltd.
Pigment derivative 2 1.2 parts alkaline resin solution 24.0 parts propylene glycol monomethyl ether acetate 60.8 parts Pigment derivative 2: Pigment derivative represented by the following chemical formula (1)

[Preparation of Yellow Pigment Dispersion Composition PY-1]
After stirring and mixing a mixture having the following composition with a disper, using a zirconia bead having a diameter of 0.5 mm, it is dispersed for 4 hours using an Eiger mill (“Mini Model M-250 MKII” manufactured by Eiger Japan) as a media type wet disperser. After that, a pigment content of 50% and a solid content of 20% were prepared to obtain a green pigment dispersion PY-1.
Pigment Yellow 138 (PY138) 20 parts "PALIOTOL YELLOW K0 961HD" manufactured by BASF
Dispersant (BYK2001) 5 parts Propylene glycol monomethyl ether acetate 75 parts.

[Preparation of Yellow Pigment Dispersion Composition PY-2]
After stirring and mixing a mixture having the following composition with a disper, using a zirconia bead having a diameter of 0.5 mm, it is dispersed for 4 hours using an Eiger mill (“Mini Model M-250 MKII” manufactured by Eiger Japan) as a media type wet disperser. After that, a pigment content of 50% and a solid content of 20% were prepared to obtain a green pigment dispersion PG-2.
Pigment Yellow 150 (PY150) 10.0 parts "E4GN" manufactured by LANXESS
Pigment derivative 2 1.5 parts alkaline resin solution 42.5 parts propylene glycol monomethyl ether acetate 46.0 parts Pigment derivative 2: Pigment derivative represented by the formula (1).

[Adjustment of green photosensitive resin composition]
A mixture having the composition (weight ratio) shown in Table 1 below was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to prepare a green photosensitive resin composition.

Monomer: Dipentaerythritol penta / hexaacrylate mixture (“M-402” manufactured by Toa Gosei Co., Ltd.)
Photopolymerization initiator 1: 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (manufactured by Ciba Specialty Chemicals) "Irgacure 379")
Photopolymerization initiator 2: Etanone, 1- [9-ethyl-6- [2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl] -9. H. -Carbazol-3-yl]-, 1- (O-acetyloxime) ("N-1919" manufactured by ADEKA Corporation)
Solvent: cyclohexanone.

[Preparation of coating film of green photosensitive resin composition]
After coating the green photosensitive resin composition shown in Table 1 on a glass substrate by spin coating, it was pre-baked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature, and then exposed using an ultrahigh pressure mercury lamp as a light source. Thereafter, this substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water and air-dried. After drying, it was post-baked at 230 ° C. for 30 minutes in a clean oven to produce a green coating film. The film thickness of the prepared coating film is measured, and the chromaticity is measured when combining a backlight using a white LED element that combines a blue LED, a red light emitting phosphor and a green light emitting phosphor as a light source. The coating conditions where the coordinates were 0.710 were determined. Each photosensitive resin composition was subjected to the above-described operation under the conditions, and a coating film for evaluation was prepared.

[Evaluation of coating film of green photosensitive resin composition]
(Spectral transmittance and hue (x, y, Y) evaluation)
Table 2 shows the results obtained by measuring the spectral transmittance and hue of the obtained coated substrate using a microspectrophotometer (“OSP-SP100” manufactured by Olympus Optical Co., Ltd.).

In Examples 1 to 3 using an aluminum phthalocyanine pigment, PY138, and an LED using a green light emitting phosphor having a peak wavelength of 520 nm to 530 nm, Comparative Example 1 using PG7 as a green pigment It was confirmed that the Y value was higher than those of Comparative Examples 3 and 4 where PY150 was used for 2 and yellow pigment.

  Even in the case of using the aluminum phthalocyanine pigment, PY138, in Comparative Example 5 using the two-wavelength LED, the Y value is remarkably reduced and the film thickness is increased compared with Examples 1 to 3, so that It was confirmed that it was important that the peak wavelength of the emission intensity of the green light emitting phosphor was in the range of 520 nm to 530 nm along with the selection.

[Production of color filter]
The pigment in the green photosensitive resin composition is C.I. in the red photosensitive resin composition. I. Pigment Red 254 / C.I. I. Pigment Red 177 = 60 parts / 40 parts, C.I. I. Pigment Blue 15: 6 / C.I. I. Pigment violet 23 was prepared in the same manner as the green photosensitive resin composition except that it was replaced with 70 parts / 30 parts.

When a red colored composition is combined with a die coater on a 100 mm × 100 mm glass substrate on which a black matrix is formed and a backlight using a white LED element as a light source is combined, the chromaticity coordinate is x = 0.680 ± 0. The film was applied to a film thickness of 010, y = 0.320 ± 0.010 to form a colored film, and the solvent was removed and dried in an oven at 70 ° C. for 20 minutes. Subsequently, stripe pattern exposure was performed with ultraviolet rays using an exposure apparatus. The exposure amount was 100 mJ / cm ² . Further, after spray development with a developer composed of an aqueous sodium carbonate solution to remove unexposed portions, the substrate was washed with ion-exchanged water, and this substrate was heated at 230 ° C. for 30 minutes to form a red pixel having a line width of about 50 μm. .

Next, according to the same operation, the chromaticity coordinates when a backlight using a white LED element as a light source is combined with a green photosensitive resin composition next to a red pixel is x = 0.210 ± 0. Green pixels were formed so that 010 and y = 0.710 ± 0.010.
Next, by the same operation, the chromaticity coordinates when combining a backlight using a white LED element as a light source using a blue photosensitive resin composition next to the red pixel and the green pixel is x = 0.150 after post-baking. Blue pixels were formed so that ± 0.010 and y = 0.060 ± 0.010. FIG. 2 is a schematic cross-sectional view showing a color filter according to an embodiment of the present invention. A color having three color pixels 3R, 3G, and 3B on the same glass substrate 1 on which the black matrix 2 is thus formed. Filter 3 was obtained.

<Production of liquid crystal display device>
FIG. 3 is a schematic sectional view showing an example of a liquid crystal display device provided with the color filter of the present invention. A transparent ITO electrode layer 12 was formed on the color filter 11 obtained as described above, and a polyimide alignment layer 13 was formed thereon. A polarizing plate 14 was formed on the other surface of the glass substrate 6. On the other hand, a TFT array 7 and a pixel electrode 8 were formed on one surface of another (second) glass substrate 5, and a polyimide alignment layer 9 was formed thereon. Further, a polarizing plate 10 was formed on the other surface. The two glass substrates 5 and 6 prepared in this way are arranged facing each other so that the electrode layers face each other, and are aligned using a photo spacer while keeping the distance between the two substrates constant. The periphery was sealed with a sealant so as to leave an opening for use. After injecting the liquid crystal composition LC from the opening, the opening was sealed. A liquid crystal display device 4 was produced by combining the liquid crystal display device thus produced with the white LED light source of the backlight unit 15.

  A liquid crystal having high color reproducibility and high brightness by using a white LED using an aluminum phthalocyanine pigment, PG58, PY138, and a green light emitting phosphor having a peak wavelength of emission intensity in the range of 525 nm to 530 nm. A display device was obtained.

  A liquid crystal display device with high color reproduction and high brightness can be provided.

DESCRIPTION OF SYMBOLS 1 ... Glass substrate, 2 ... Black matrix, 3, 11 ... Color filter, 4 ... Liquid crystal display device, 5, 6 ... Transparent substrate, 7 ... TFT array, 8, 12 ... Transparent electrode, 9, 13 ... Orientation layer, 10 , 14 ... Polarizing plate, 15 ... Backlight unit.

Claims (3)

  A back provided with a white LED device combining a blue LED, a red light emitting phosphor and a green light emitting phosphor, having a peak wavelength of emission intensity within each wavelength range of 430 nm to 470 nm, 520 nm to 530 nm, and 610 nm to 670 nm. A color filter having a plurality of colored pixels including a green pixel on a transparent substrate, which is used in a liquid crystal display device having a light, and the green pixel contains an aluminum phthalocyanine pigment, Pigment Green 58, and Pigment Yellow 138 A color filter characterized by that. The display chromaticity measured by the backlight using the white LED element as the light source is in the range of x = 0.210 ± 0.010, y = 0.710 ± 0.010 in the XYZ color system, and the brightness is 42. The color filter according to claim 1, further comprising a green pixel that is 5 or more.   A liquid crystal display device comprising the color filter according to claim 1.