JP2007183590A - Color filter, liquid crystal display device provided therewith, and apparatus for measuring the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter and a liquid crystal display device provided with the same having satisfactory color characteristics during black display of the liquid crystal display device and superior in visibility. <P>SOLUTION: In the color filter provided with filter segments of red, green, and blue; expression (1) L<SB>Outside</SB>/L<SB>Inside</SB>>0.30 is satisfied. L<SB>Inside</SB>is the luminance when the color filter is disposed between a pair of polarizes arranged in a crossed Nichol state and irradiated with light, and L<SB>Outside</SB>is the luminance when the color filter is disposed outside the pair of polarizes arranged in the state and irradiated with light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

 The present invention relates to a color filter, a liquid crystal display device including the color filter, and a color filter measuring device.

 A color liquid crystal display device is basically sealed between a first transparent substrate on which a first transparent electrode layer is formed, a second transparent substrate on which a second transparent electrode layer is formed, and a gap between them. The color filter is usually formed between the second transparent substrate and the second transparent electrode. First and second polarizing plates are provided outside the first and second transparent substrates, respectively, and a backlight unit including a backlight light source is provided outside the first polarizing plate. .

 In such a liquid crystal display device, the voltage applied between the first and second transparent electrode layers is adjusted for each filter segment, and the degree of polarization of light from the backlight unit that has passed through the first polarizing plate is controlled. The display is performed by controlling the amount of light passing through the second polarizing plate. Therefore, the color characteristics of the color filter and the polarizing plate are important factors that determine the color characteristics of the liquid crystal display device.

 A color filter has a black matrix, which is a light shielding pattern, and red, green, and blue fine band (striped) filter segments arranged in parallel or intersecting on the surface of a transparent substrate such as glass, or a fine filter. It is composed of filter segments arranged in a constant arrangement.

 In recent years, liquid crystal display devices have been evaluated for space saving, light weight, power saving, etc. due to their thinness, and their applications are rapidly expanding for large televisions and monitors. The demand for higher brightness, higher color reproducibility, and higher contrast is increasing for color filters that determine the color characteristics.

 The conventional color filter has orthogonal transmission light when the color filter is disposed between a pair of polarizing plates (lightly crossed Nicols with the polarization axes of the two polarizing plates orthogonal to each other). By controlling the contrast ratio, which is the ratio between the transmitted light leaking) and the parallel transmitted light (transmitted light in the state where the polarization axes of the two polarizing plates are parallel to each other), the white display and It has been attempted to improve the color reproducibility of black display.

However, just controlling the contrast ratio calculated from the brightness when irradiating light with a color filter placed between a pair of polarizing plates, the contrast depends on the polarizing plate used, the measurement environment, the instrumental differences of the measuring instrument, etc. Since it is very difficult to reproduce the ratio itself, there are still many inferior visibility during black display. This is because the polarizing plate itself used for measuring the contrast ratio has a property of leaking light in the crossed Nicols state. As a result, it has been difficult to obtain sufficient display quality for large-sized televisions, monitors and the like.
JP 2005-316439 A

 SUMMARY OF THE INVENTION An object of the present invention is to provide a color filter that has excellent color characteristics during black display of a liquid crystal display device and has excellent visibility, and a liquid crystal display device including the color filter.

 It is another object of the present invention to provide a measuring device for accurately evaluating the influence of a color filter on the color characteristics of a liquid crystal display device during black display.

In order to solve the above problems, a first aspect of the present invention is a color filter including red, green and blue filter segments, wherein the color filter is disposed between a pair of polarizing plates disposed in a crossed Nicol state, When the luminance when irradiated with light is L _Inside , the color filter is disposed outside the pair of polarizing plates arranged in the same state, and the luminance when irradiated with light is L _Outside , the following formula (1 The color filter is characterized by satisfying the above.

L _Outside / L _Inside > 0.30 (1)
In such a color filter, the red filter segment is formed of a red coloring composition containing a transparent resin, a precursor thereof, or a pigment carrier made of a mixture thereof, and a red pigment, and the red coloring composition Is disposed between a pair of polarizing plates arranged in a crossed Nicol state, the luminance when irradiated with light is L (R) _Inside, and the outside of the pair of polarizing plates arranged in the same state The above-mentioned red coating film is disposed on the surface, and the luminance when irradiated with light is L (R) _Outside , the following formula (2) can be satisfied.

L (R) _Outside / L (R) _Inside > 0.15 (2)
The green filter segment is formed from a green coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof or a mixture thereof, and a green pigment, and is formed from the green coloring composition. A coating film is arranged between a pair of polarizing plates arranged in a crossed Nicol state, and the luminance when irradiated with light is L (G) _Inside, and the green coating film is placed outside the pair of polarizing plates arranged in the same state. And the luminance when irradiated with light is L (G) _Outside , the following formula (3) can be satisfied.

L (G) _Outside / L (G) _Inside > 0.40 (3)
The blue filter segment is formed from a blue coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof, or a mixture thereof, and a blue pigment, and is formed from the blue coloring composition. The coating film is arranged between a pair of polarizing plates arranged in a crossed Nicol state, and the luminance when irradiated with light is L (B) _Inside, and the blue coating film is placed outside the pair of polarizing plates arranged in the same state. When the luminance when irradiating light is L (B) _Outside , the following formula (4) can be satisfied.

L (B) _Outside / L (B) _Inside > 0.45 (4)
Further, the red, green and blue filter segments are formed from a red, green and blue coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof or a mixture thereof, and a red, green and blue pigment. And the red, green, and blue coating films formed from the colored compositions are arranged between a pair of polarizing plates arranged in a crossed Nicol state, and irradiated with light at a maximum peak wavelength at 400 to 700 nm. The radiance is R (R) _Inside , R (G) _Inside , R (B) _Inside, and the red, green or blue coating film is placed outside the pair of polarizing plates arranged in the same state, and the light is emitted. When the radiance at the maximum peak wavelength when irradiated is R (R) _Outside , R (G) _Outside , and R (B) _Outside , respectively, The expressions (5) to (7) can be satisfied.

R (R) _Outside / R (R) _Inside > 0.18 (5)
R (G) _Outside / R (G) _Inside > 0.30 (6)
R (B) _Outside / R (B) _Inside > 0.70 (7)
In the above color filter, it is desirable that the primary particle diameter of the pigment contained in the colored composition used for forming the red, green, and blue filter segments is 40 nm or less.

 A second aspect of the present invention provides a liquid crystal display device including the color filter described above.

According to a third aspect of the present invention, there is provided a measuring apparatus comprising (A) a pair of polarizing plates in which at least one of the polarizing plates can be rotated in a plane, (B) a luminance meter, and (C) a light source. Means for accurately arranging in a crossed Nicol state, means for holding the color filter between the pair of polarizing plates, and means for holding the color filter outside the pair of polarizing plates, and the above-described L _Inside , L _Outside , L _Inside / L _Outside , R (X) _Outside , R (X) _Inside , and R (X) _Outside / R (X) _Inside (where X is R, G, or B) I will provide a.

 According to the color filter of the first aspect of the present invention, the luminance of the orthogonal transmitted light measured by arranging the color filter between the pair of polarizing plates arranged in the crossed Nicols state, and the pair of polarized lights arranged in the same state Providing a high-quality liquid crystal display device with good color reproducibility for black display and excellent visibility because the ratio with the brightness of orthogonal transmitted light measured by placing a color filter on the outside of the plate is appropriate Can do.

 Further, according to the liquid crystal display device according to the second aspect of the present invention, since the color filter is provided, the color reproducibility of black display is good, the visibility is excellent, and the quality is high.

 Moreover, according to the measuring apparatus which concerns on the 3rd aspect of this invention, it is a measuring apparatus provided with (A) a pair of polarizing plate (B) luminance meter (C) light source which at least one can rotate in plane, and at least one pair. Means for accurately arranging the polarizing plate in a crossed Nicol state, means for holding the color filter between the pair of polarizing plates, and means for holding the color filter outside the pair of polarizing plates. The ratio between the luminance of orthogonal transmission light with a color filter placed between a pair of polarizing plates arranged in a Nicol state and the luminance of orthogonal transmission light with a color filter arranged outside the pair of polarizing plates arranged in the same state Since the measurement can be easily performed with good reproducibility, it is possible to accurately evaluate the influence of the color filter on the color characteristics of the liquid crystal display device during black display.

 Hereinafter, embodiments of the present invention will be described.

The color filter according to the first embodiment of the present invention includes red, green, and blue filter segments, and the color filter is interposed between a pair of polarizing plates arranged in a crossed Nicol state, as shown in FIG. A filter is arranged, the luminance when irradiated with light is L _Inside , and the color filter is arranged outside a pair of polarizing plates arranged in the same state as shown in FIG. When the luminance at the time is L _Outside , the following expression (1) is satisfied.

L _Outside / L _Inside > 0.30 (1)
A liquid crystal display device including a color filter having a luminance ratio L _Outside / L _Inside within the above range has excellent visibility during black display. The luminance ratio L _Outside / L _Inside is preferably greater than 0.40, and more preferably greater than 0.50.

Luminance L _Outside and L _Inside are measured with a color luminance meter (“BM-5A” manufactured by Topcon Corporation) under the condition of 2 ° visual field.

 In FIG. 1B, for the sake of convenience, the state in which the color filter is disposed between the pair of polarizing plates and the light source is illustrated, but the color filter may be disposed between the pair of polarizing plates and the luminance meter. This is the same in the following description.

The light source has an emission spectrum as shown in FIG. 2, luminance = 1937 cd / m ² , chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301), The color temperature = 6525K and the chromaticity deviation duv = −0.0136 are used. As the polarizing plate, “NPF-SEG1224DU” manufactured by Nitto Denko Corporation is used.

In order to improve the color characteristics at the time of black display of the liquid crystal display device, in each of the red, green, and blue filter segments constituting the color filter, each color filter segment includes a pigment carrier made of a transparent resin, a precursor thereof, or a mixture thereof. Each color coating film formed from each color coloring composition containing each color pigment and formed from each color coloring composition is disposed between a pair of polarizing plates arranged in a crossed Nicol state as shown in FIG. The luminance when arranged and irradiated with light is L (R) _Inside , L (G) _Inside , and L (B) _Inside , respectively, and arranged in the same state as shown in FIG. each of said color coating disposed outside the respective luminance when irradiated with light _{L (R) outside, L (} G) outside, L (B) outside, L ( ) When formed into a _{Outside Outside,} it is preferable to satisfy the following formula (2) (3) (4).

L (R) _Outside / L (R) _Inside > 0.15 (2)
L (G) _Outside / L (G) _Inside > 0.40 (3)
L (B) _Outside / L (B) _Inside > 0.45 (4)
Luminance ratio L (R) _Outside / L (R) _Inside , L (G) _Outside / L (G) _Inside , L (B) _Outside / L of each color coating film related to the luminance ratio L _Outside , L _Inside (B) _Inside is preferably a high value, preferably close to 1.00. The luminance ratio of each color coating film is more preferably L (R) _Outside / L (R) _Inside > 0.30, L (G) _Outside / L (G) _Inside > 0.50, L (B) _Outside / L (B) _Inside > 0.60, and more preferably L (R) _Outside / L (R) _Inside > 0.40, L (G) _Outside / L (G) _Inside > 0.60, L (B ) _Outside / L (B) _Inside > 0.70.
Further, in order to improve the color characteristics at the time of black display of the liquid crystal display device, the red, green, and blue filter segments constituting the color filter include a pigment carrier made of a transparent resin, a precursor thereof, or a mixture thereof, and a pigment. Between a pair of polarizing plates formed from a colored composition containing each color and arranged in a crossed Nicol state as shown in FIG. 1 (a) with a red, green or blue coating film formed from each colored composition. 1 and R (R) _Inside , R (G) _Inside , R (B) _Inside , respectively, as shown in FIG. 1 (b). the red, arranged green or blue coating, the radiance at the maximum peak wavelength when irradiated with light each R (R) _Out outside of the pair of polarizing plates placed in the same state _ide, R (G) _Outside, when the R (B) _{Outside Outside,} it is preferable to satisfy the following formula (5) to (7).

R (R) _Outside / R (R) _Inside > 0.18 (5)
R (G) _Outside / R (G) _Inside > 0.30 (6)
R (B) _Outside / R (B) _Inside > 0.70 (7)
The radiance ratio R (R) _Outside / R (R) _Inside , R (G) _Outside / R (G) _Inside , R (B) _Outside / R (B) _Inside of each color coating film is desirably a high value. It is preferably close to 0.000.

The radiance ratio of each color coating is more preferably R (R) _Outside / R (R) _Inside > 0.30, R (G) _Outside / R (G) _Inside > 0.60, R (B) _Outside / R (B) _Inside > 0.80, more preferably R (R) _Outside / R (R) _Inside > 0.50, R (G) _Outside / R (G) _Inside > 0.70, R ( B) _Outside / R (B) _Inside > 0.90.
The radiances R _Outside and R _Inside are measured with a spectral radiance meter (“CS-1000A” manufactured by Konica Minolta, Inc.) under the condition of 2 ° visual field.

 Each color filter segment included in the color filter according to the first embodiment of the present invention contains a pigment carrier made of a transparent resin, a precursor thereof, or a mixture thereof, a pigment, and an organic solvent as necessary. It is formed using a coloring composition.

 As a pigment contained in a coloring composition, an organic or inorganic pigment can be used individually or in mixture of 2 or more types. Among the pigments, pigments having high color developability and high heat resistance, particularly pigments having high heat decomposition resistance are preferred, and organic pigments are usually used.

 Below, the specific example of the organic pigment which can be used for a coloring composition is shown with a color index number.

 Blue colored compositions for forming blue filter segments include, for example, CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 80 A blue pigment such as CI Pigment Blue 15: 6 can be used.

 Further, purple pigments such as CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50, preferably CI Pigment Violet 23 can be used in combination with the blue coloring composition. .

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

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

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

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

 Inorganic pigments include yellow lead, zinc yellow, red bean (red iron (III) oxide), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green and other metal oxide powders, metal sulfide powders, metal powders Etc. Inorganic pigments are used in combination with organic pigments in order to ensure good coatability, sensitivity, developability and the like while maintaining a balance between saturation and lightness.

 The coloring composition can contain a dye within a range that does not reduce heat resistance for color matching.

 The pigment contained in the coloring composition is preferably subjected to a finer treatment and preferably has a small primary particle diameter in order to achieve high brightness and high contrast of the color filter. The primary particle diameter of the pigment is calculated by taking the pigment with a transmission electron microscope and analyzing the image of the photograph. The primary particle diameter referred to here represents a particle diameter (equivalent circle diameter) corresponding to 50% of the total amount in the cumulative curve of the number particle size distribution.

 The primary particle diameter of the pigment is preferably 40 nm or less, more preferably 30 nm or less, and still more preferably 20 nm or less. Moreover, it is preferable that a primary particle diameter is 5 nm or more.

 When the primary particle diameter of the pigment is larger than the upper limit value, the visibility of the liquid crystal display device during black display tends to be poor. On the other hand, when it is smaller than the lower limit, it becomes difficult to disperse the pigment, and it becomes difficult to maintain the stability as the colored composition and to secure the fluidity. As a result, the luminance and color characteristics of the color filter tend to deteriorate.

 As a means for controlling the primary particle diameter of the pigment, a method of controlling the primary particle diameter 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 the desired primary particle diameter is controlled. There are a method for precipitating a pigment having a particle size (referred to as a precipitation method) and a method for producing a pigment having a desired primary particle size at the time of synthesis (referred to as a synthetic precipitation method). Depending on the synthesis method and chemical properties of the pigment to be used, an appropriate method can be selected for each pigment.

 Any of the above methods may be used as a method for controlling the primary particle size of the pigment contained in the coloring composition used in the first embodiment of the present invention. Each method will be described in more detail below.

 In the grinding method, the pigment is mechanically kneaded using a ball mill, sand mill or kneader together with a grinding agent such as water-soluble inorganic salt such as salt and a water-soluble organic solvent that does not dissolve it. In this method, the inorganic salt and the organic solvent are washed away with water and dried to obtain a pigment having a desired primary particle size. 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. In general, the inorganic salt is used in an amount of 1 to 30 parts by weight, preferably 2 to 20 parts by weight, based on 1 part by weight of the pigment. The water-soluble organic solvent is added so that the pigment and the inorganic salt are uniformly solidified. Although depending on the blending ratio of the pigment and the inorganic salt, the water-soluble organic solvent is usually added in an amount of 0.1% by weight per 1 part by weight of the pigment. Used in an amount of 5 to 30 parts by weight.

 More specifically, with respect to the above grinding method, a small amount of a water-soluble organic solvent is added as a wetting agent to a mixture of a pigment and a water-soluble inorganic salt, and after kneading with a kneader or the like, the mixture is poured 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 primary particle size.

 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 primary particle size. Depending on the type and amount of the solvent, the precipitation temperature, the precipitation rate, etc. The primary particle size can be controlled. In general, pigments are difficult to dissolve in solvents, so the solvents that can be used are limited. For example, strongly acidic solvents such as concentrated sulfuric acid, polyphosphoric acid and chlorosulfonic acid, or basic solvents such as dimethylformamide solution of liquid ammonia and sodium methylate Etc. are known.

 As a typical example of the precipitation method, there 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 becomes high and handling becomes worse. Conversely, if the amount is too large, the processing efficiency of the pigment decreases. It is preferable to use sulfuric acid. The pigment does not need to be completely dissolved in the solvent.

 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, which is dangerous. It will freeze at temperatures below this. The time required for injection is preferably 0.1 to 30 minutes with respect to 1 part of the pigment. As the time increases, the primary particle size tends to increase.

 The primary particle size of the pigment can be controlled 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, while taking into account the fine particle size of the pigment. At this time, it is more preferable because the fluidity as a dispersion can be secured.

 At the time of salt milling or acid pasting, in order to prevent aggregation of the pigment accompanying the control of the primary particle size, the following dispersion aids such as a dye derivative, a resin-type pigment dispersant, and a surfactant can be used in combination. Further, by controlling the primary particle size in the form of coexistence of 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. In this method, vat dyes such as flavantron, perinone, perylene, and indanthrone are reduced with alkaline hydrosulfite, and the quinone group becomes hydroquinone sodium salt (leuco compound), which is water-soluble. become. A pigment having a small primary particle size 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 of synthesizing a pigment and simultaneously depositing a pigment having a desired primary particle size. 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 for controlling the primary particle diameter of the pigment, the primary particle diameter of the pigment is reduced and dispersed simultaneously 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). It is also possible.

 The pigment carrier contained in the coloring composition for a color filter used in the first embodiment of the present invention disperses the pigment, and is composed of a transparent resin, a precursor thereof, or a mixture thereof. 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 the precursor includes a monomer or an oligomer that is cured by radiation irradiation to form a transparent resin, and these are used alone. Or a mixture of two or more.

 The pigment carrier can be used in an amount of 30 to 700 parts by weight, preferably 60 to 450 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition. When a mixture of a transparent resin and its precursor is used as a pigment carrier, the transparent resin is 20 to 400 parts by weight, preferably 50 to 250 parts by weight, based on 100 parts by weight of the pigment in the coloring composition. Can be used. The precursor of the transparent resin can be used in an amount of 10 to 300 parts by weight, preferably 10 to 200 parts by weight, with respect to 100 parts by weight of the pigment in the coloring composition.

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

 Monomers and oligomers that are precursors of transparent resins include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, various acrylic esters such as epoxy (meth) acrylate and methacrylic acid Examples include esters, (meth) acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and acrylonitrile. These can be used alone or in admixture of two or more.

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

 Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Hydroxycyclohexyl phenyl ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- Acetophenone photopolymerization initiators such as 1-one, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4 -F Benzophenone photopolymerization initiators such as nylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Thioxanthone photopolymerization initiators such as 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s- Triazine, 2,4-bis (trichloro Methyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, etc. A polymerization initiator, a borate photopolymerization initiator, a carbazole photopolymerization initiator, an imidazole photopolymerization initiator, or the like is used.

 A photoinitiator can be used in the amount of 5-200 weight part with respect to 100 weight part of pigments in a coloring composition, Preferably it is 10-150 weight part.

 The above photopolymerization initiators are used alone or in combination of two or more. As sensitizers, α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone. , Camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, etc. It can also be used together.

 The sensitizer can be contained in an amount of 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

 Furthermore, the coloring composition can contain a polyfunctional thiol that functions as a chain transfer agent.

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

 The polyfunctional thiol can be used in an amount of 0.2 to 150 parts by weight, preferably 0.2 to 100 parts by weight, with respect to 100 parts by weight of the pigment in the coloring composition.

 Furthermore, in the color filter coloring composition used in the first embodiment of the present invention, the pigment is sufficiently dispersed in the pigment carrier, and the dry film thickness is 0.2 to 5 μm on a transparent substrate such as a glass substrate. In order to make it easy to apply and form a filter segment, a solvent can be included. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether, toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These may be used alone or in combination.

 The solvent can be used in an amount of 800 to 4000 parts by weight, preferably 1000 to 2500 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

   The coloring composition comprises one or more pigments, if necessary, together with the above photopolymerization initiator, in a pigment carrier and an organic solvent, such as a three roll mill, a two roll mill, a sand mill, a kneader, and an attritor. It can be produced by finely dispersing using a dispersing means. Moreover, the coloring composition containing 2 or more types of pigments can also be manufactured by mixing each pigment separately finely dispersed in a pigment carrier and an organic solvent. When the pigment is dispersed in the pigment carrier and the organic solvent, a dispersion aid such as a resin-type pigment dispersant, a surfactant, or a pigment derivative can be appropriately contained. Since the dispersion aid is excellent in pigment dispersion and has a great effect of preventing re-aggregation of the pigment after dispersion, a coloring composition comprising a pigment dispersed in a pigment carrier and an organic solvent using a dispersion aid is used. If so, a color filter excellent in transparency can be obtained.

 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 coloring composition.

 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 pigment carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the pigment carrier. It works. Specific examples of resin-type pigment dispersants include polyurethanes, polycarboxylic acid esters such as polyacrylates, 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 alkylene imines) 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.

 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.

 The dye derivative is a compound in which a substituent is introduced into an organic dye, and is preferably close to the hue of the pigment to be used. However, if the addition amount is small, those having different hues may be used. Organic dyes also include light yellow aromatic polycyclic compounds such as naphthalene and anthraquinone that are not generally called dyes. Examples of the dye derivatives are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. You can use what you have. In particular, a pigment derivative having a basic group is preferably used because it has a large pigment dispersion effect. These can be used alone or in admixture of two or more.

 The coloring composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Examples of storage stabilizers include quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and organic acids such as methyl ether, t-butylpyrocatechol, tetraethylphosphine, and tetraphenylphosphine. Examples thereof include phosphine and phosphite.

 The storage stabilizer can be contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

 In addition, the coloring composition may contain an adhesion improving agent such as a silane coupling agent in order to improve the adhesion to the substrate.

 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 contained in an amount of 0.01 to 100 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

 The coloring composition can be prepared in the form of gravure offset printing ink, waterless offset printing ink, silk screen printing ink, solvent development type or alkali development type coloring resist. The colored resist is obtained by dispersing a dye in a composition containing a thermoplastic resin, a thermosetting resin or a photosensitive resin, a monomer, a photopolymerization initiator, and an organic solvent.

 The pigment is preferably contained in a proportion of 5 to 70% by weight based on the total solid content of the colored composition (100% by weight). More preferably, it is contained in a proportion of 20 to 50% by weight, and the remainder consists essentially of a resinous binder provided by a pigment carrier.

 The colored composition is removed by means of centrifugal separation, sintering filter, membrane filter, etc. to remove 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 It is preferable to carry out.

 A color filter according to the first embodiment of the present invention includes a red filter segment, a green filter segment, and a blue filter that are formed on a transparent substrate by the printing method or the photolithography method using the above-described colored compositions. It has a segment.

 As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali aluminoborosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, polyethylene terephthalate are used. Further, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the glass plate or the resin plate for driving the liquid crystal after the liquid crystal panel is formed.

 The formation of each color filter segment by the printing method can be patterned simply by repeating the printing and drying of the colored composition prepared as the above various printing inks. Therefore, the color filter manufacturing method is low-cost and excellent in mass productivity. ing. Furthermore, it is possible to print a fine pattern having high dimensional accuracy and smoothness by the development of printing technology. In order to perform printing, it is preferable that the composition does not dry and solidify on the printing plate or on the blanket. Control of ink fluidity on a printing press is also important, and ink viscosity can be adjusted with a dispersant or extender pigment.

 When each color filter segment is formed by photolithography, the colored composition prepared as the solvent development type or alkali development type color resist is applied on a transparent substrate, such as spray coating, spin coating, slit coating, roll coating, etc. By a method, it apply | coats so that a dry film thickness may be set to 0.2-10 micrometers. When drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used.

 If necessary, the dried film is exposed to ultraviolet light through a photomask having a predetermined pattern provided in contact with or non-contact with the film. Then, immerse in a solvent or alkaline developer or spray the developer with a spray to remove the uncured part, form the desired pattern, and repeat the same operation for other colors to produce a color filter. can do. Furthermore, in order to accelerate the polymerization of the colored resist, heating can be performed as necessary. According to the photolithography method, a color filter with higher accuracy than the above printing method can be manufactured.

 In development, 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 order to increase the UV exposure sensitivity, the colored resist is applied and dried, and then a water-soluble or alkaline water-soluble resin such as polyvinyl alcohol or a water-soluble acrylic resin is applied and dried to inhibit polymerization inhibition by oxygen. Ultraviolet exposure can also be performed after the film to be prevented is formed.

 The color filter according to the first embodiment of the present invention can be manufactured by an electrodeposition method, a transfer method or the like in addition to the above method. The electrodeposition method is a method for producing a color filter by using a transparent conductive film formed on a transparent substrate and forming each color filter segment on the transparent conductive film by electrophoresis of colloidal particles. is there. The transfer method is a method in which a color filter layer is formed in advance on the surface of a peelable transfer base sheet, and this color filter layer is transferred to a desired transparent substrate.

Next, a liquid crystal display device including the color filter according to the first embodiment of the present invention will be described.
FIG. 3 is a schematic cross-sectional view of a liquid crystal display device according to the second embodiment of the present invention, which includes the color filter according to the first embodiment of the present invention described above. A liquid crystal display device 10 shown in FIG. 3 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 11 and 21 that are arranged to be spaced apart from each other. Liquid crystal (LC) is enclosed. The present invention can be applied to liquid crystal display devices in drive modes such as TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefringence).

 A TFT (thin film transistor) array 12 is formed on the inner surface of the first transparent substrate 11, and a transparent electrode layer 13 made of, for example, ITO is formed thereon. An alignment layer 14 is provided on the transparent electrode layer 13. A polarizing plate 15 is formed on the outer surface of the transparent substrate 11.

 On the other hand, the color filter 22 according to the first embodiment of the present invention is formed on the inner surface of the second transparent substrate 21. The red, green and blue filter segments constituting the color filter 22 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 22 and further, a transparent electrode layer 23 made of, for example, ITO is formed thereon, and the alignment layer 24 covers the transparent electrode layer 23. Is provided. A polarizing plate 25 is formed on the outer surface of the transparent substrate 21. A backlight unit 30 having a three-wavelength lamp 31 as a light source is provided below the polarizing plate 15.

 Next, a measurement apparatus according to the third embodiment of the present invention will be described.

As apparent from the above description, in the first embodiment of the present invention, the color filter _{L Inside, L Outside Outside,} and _{L Outside} / L _{Inside and, R (X) Outside, R} (X) Inside, and R (X) _Outside / R (X) _Inside (X is R, G, or B) is an important parameter that affects the visibility of the liquid crystal display device during black display. In order to accurately measure these values, it is necessary to measure the luminance by changing the positional relationship between the color filter and the polarizing plate while keeping the arrangement of the crossed Nicols state of the polarizing plate in good reproducibility.

However, arranging the crossed Nicols state of the polarizing plate with good reproducibility is largely dependent on the skill level of the measurer, and the measurement needs to be performed by changing the vertical relationship between the polarizing plate and the color filter. The measurement procedure becomes complicated. Therefore, these L _Inside , L _Outside , L _Outside / L _Inside , and R (X) _Outside , R (X) _Inside , R (X) _Outside / R (X) _Inside (where X is R, G or B) are important However, there is a problem that it is difficult to measure easily and with good reproducibility even though it is a simple evaluation parameter.

 In order to solve this problem, the present inventors have made various studies and can obtain the crossed Nicols state of the polarizing plate with good reproducibility, and easily change the positional relationship between the color filter and the polarizing plate and measure these parameters. It came to realize the device that can.

 A conceptual diagram of a measuring apparatus according to the third embodiment of the present invention is shown in FIG. This measuring apparatus includes a luminance meter 32, stages 39 and 40, and a light source 37. One of the pair of polarizing plates 33, 35, for example, the polarizing plate 33 is held on a rotary stage (not shown) and is slid between the pair of polarizing plates 33, 35 that can freely rotate. A stage 39 that can slide between the polarizing plate 35 and the light source 37, both of which hold the color filters 34 and 34 ′. In FIG. 4, for convenience, the stage 40 is illustrated between the pair of polarizing plates and the light source, but the stage 40 may be disposed between the pair of polarizing plates and the luminance meter. In FIG. 4, the stages 39 and 40 are illustrated for convenience, but it is desirable to have a function of sliding on a single stage.

 With such a configuration, the color filter 34 is held on the stage 39, and the luminance or spectral radiance of the light 38 when disposed between the pair of polarizing plates, and the color filter 34 'is held on the stage 40, and the pair of polarizations The luminance or spectral radiance of the light 38 when placed outside the plate is measured by the luminance meter 32 or the spectral radiance meter 32. The luminance meter 32 is typically a “BM-5A” manufactured by Topcon as a color luminance meter, or “CS-1000A” manufactured by Konica Minolta as a spectral radiance meter, and can accurately measure luminance or spectral luminance. If it is a thing, it will not be limited to these.

The light source has an emission spectrum as shown in FIG. 2, luminance = 1937 cd / m ² , chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301), Although it has the characteristics of color temperature = 6525K and chromaticity deviation duv = −0.0136, a general three-wavelength tube emitting white light or a halogen lamp emitting white light may be used. The polarizing plate uses “NPF-SEG1224DU” manufactured by Nitto Denko Corporation, but is not limited thereto.

FIG. 5 shows an operation flow of the measuring apparatus according to this embodiment. Operation flow _L Inside using a luminance meter (such as color luminance meter _BM-5A), L _Outside, but is intended to measure the _{L Outside / L Inside, R (} X) Outside, R (X) Inside, R ( X) _Outside / R (X) _Inside (X is R, G or B), the maximum of the spectral radiance obtained using a spectral radiance meter (such as the spectral radiance meter CS-1000) at 400 to 700 nm Measurement is possible by setting the radiance at the peak wavelength to R (X) _Outside and R (X) _Inside .

Thus, L _Inside , L _Outside , L _Outside / L _Inside , and R (X) _Outside , R (X) _Inside , R (X) _Outside / R (X) _Inside / ( X can easily measure R, G or B) with good reproducibility, and enables stable evaluation independent of the skill level of the evaluator. At the same time, since the conventional contrast ratio can also be measured, it is also possible to give an advantage that it is easy to make comparison with the conventional evaluation parameters.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

 In the examples and comparative examples, “parts” means “parts by weight”.

[Preparation of pigment]
The pigments used in Examples and Comparative Examples were prepared by the following method. The obtained pigment was photographed through a transmission electron microscope, and the primary particle diameter of the pigment was calculated by performing image analysis of the photograph. The primary particle diameter referred to here represents a particle diameter (equivalent circle diameter) corresponding to 50% of the total amount in the cumulative curve of the number particle size distribution. The results are shown in Table 1 below. The dispersants used in the examples and comparative examples are shown in Table 2 below.

[Red Pigment 2 (R-2)]
136 parts of Red Pigment 1 (CI Pigment Red 254, “IRGAPHOR RED B-CF” manufactured by Ciba Specialty Chemicals; R-1), 24 parts of Dispersant A-1 shown in Table 2, and 1600 parts of sodium chloride In addition, 190 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) was charged into a stainless gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 60 ° C. for 8 hours.

 Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 2).

[Red Pigment 4 (R-4)]
160 parts of red pigment 3 (CI Pigment Red 177, “CROMOPHTAL RED A2B”; R-3) manufactured by Ciba Specialty Chemicals, 1600 parts of sodium chloride, and 190 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are made of 1 gallon kneader made of stainless steel. (Made by Inoue Seisakusho) and kneaded at 60 ° C. for 12 hours.

 Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 4).

[Green Pigment 2 (G-2)]
500 parts of Green Pigment 1 (CI Pigment Green 36, “LIONOL GREEN 6YK” manufactured by Toyo Ink Co., Ltd .; G-1), 1300 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) 1 gallon kneader (Inoue) And kneaded at 70 ° C. for 3 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 496 parts of a salt milled pigment (green pigment 2).

[Green Pigment 3 (G-3)]
200 parts of green pigment 1, 1500 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 8 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 197 parts of a salt milled pigment (green pigment 3).

[Green Pigment 4 (G-4)]
120 parts of green pigment 1, 1600 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 12 hours. Next, this mixture is poured into about 5 liters of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C., and then slurried, filtered, washed with water to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 117 parts of a salt milled pigment (green pigment 4).

[Yellow Pigment 1 (Y-1)]
BAYER “FANCHON FAST YELLOW Y-5688” (CI Pigment Yellow 150) is designated as Yellow Pigment 1.

[Yellow Pigment 2 (Y-2)]
200 parts of yellow pigment (CI Pigment Yellow 138, “PALIOTOL YELLOW K0961HD” manufactured by BASF), 1500 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a 1 gallon kneader (manufactured by Inoue Seisakusho) made of stainless steel. The mixture was kneaded at 60 ° C. for 6 hours. Next, the mixture is poured into about 5 liters of warm water and stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 196 parts of a salt milled pigment (yellow pigment 2).

[Yellow Pigment 3 (Y-3)]
160 parts of yellow pigment (CI Pigment Yellow 138, “PALIOTOL YELLOW K0961HD” manufactured by BASF), 1600 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Kasei Co., Ltd.) were charged into a 1 gallon kneader (manufactured by Inoue Seisakusho) made of stainless steel. It knead | mixed for 15 hours at 60 degreeC. Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 157 parts of a salt milled pigment (yellow pigment 3).

[Blue Pigment 2 (B-2)]
Blue Pigment 1 (CI Pigment Blue 15: 6, “LIONOL BLUE ES” manufactured by Toyo Ink Co., Ltd .; B-1) 200 parts, sodium chloride 1600 parts and diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) 100 parts 1 gallon kneader made of stainless steel (Made by Inoue Seisakusho) and kneaded at 70 ° C. for 12 hours. Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 198 parts of a salt milled pigment (blue pigment 2).

[Blue Pigment 3 (B-3)]
160 parts of blue pigment 2, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 15 hours. Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 158 parts of a salt milled pigment (blue pigment 3).

[Purple Pigment 2 (V-2)]
300 parts of purple pigment 1 (CI Pigment Violet 23, “LIONOGEN VIOLET RL” manufactured by Toyo Ink Manufacturing Co., Ltd .; V-1) was added to 3000 parts of 96% sulfuric acid, stirred for 1 hour, and poured into 5 ° C. water. After stirring for 1 hour, the mixture was filtered, washed with warm water until the washing solution became neutral, and dried at 70 ° C. 200 parts of the obtained acid pasting pigment, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 90 ° C. for 6 hours.

 Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 198 parts of a salt milled pigment (purple pigment 2).

[Purple Pigment 3 (V-3)]
300 parts of purple pigment 1 was added to 3000 parts of 96% sulfuric acid, stirred for 1 hour, and poured into water at 5 ° C. After stirring for 1 hour, the mixture was filtered, washed with warm water until the washing solution became neutral, and dried at 70 ° C. 120 parts of the obtained acid pasting pigment, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 90 ° C. for 18 hours.

 Next, this mixture is poured into about 5 liters of warm water, stirred in a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered, washed with water to remove sodium chloride and diethylene glycol. And dried at 80 ° C. for 24 hours to obtain 118 parts of a salt milled pigment (purple pigment 3).

[Preparation of acrylic resin solution]
Next, preparation of the acrylic resin solution used in Examples and Comparative Examples will be described. The molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

 370 parts of cyclohexanone was placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out a polymerization reaction.

Methacrylic acid 20.0 parts Methyl methacrylate 10.0 parts n-Butyl methacrylate 35.0 parts 2-Hydroxyethyl methacrylate 15.0 parts 2,2'-Azobisisobutyronitrile 4.0 parts Paracmylphenol ethylene oxide modification Acrylate 20.0 parts ("Aronix M110" manufactured by Toa Gosei Co., Ltd.)
After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, then 1.0 part of azobisisobutyronitrile dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour, An acrylic resin solution was obtained. The weight average molecular weight of this acrylic resin was about 40,000.

  After cooling to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20% by weight. To prepare an acrylic resin solution.

[Preparation of pigment dispersion]
A mixture having the composition (weight ratio) shown in Table 3 below was uniformly stirred and mixed, then dispersed with an Eiger mill for 2 hours using zirconia beads having a diameter of 0.5 mm, filtered through a 5 μm filter, and pigment dispersion RP -1 to 3, GP-1 to 4, and BP-1 to 4 were produced.

[Preparation of colored composition (hereinafter referred to as resist)]
Subsequently, the mixture (weight ratio) shown in Table 4 below was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to form each color resist RR-1 to GR, GR-1 to BR-4, and BR-1. ~ 4 were obtained.

Monomer: Trimethylolpropane triacrylate (“NK ESTER ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.)
Photopolymerization initiator: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (“Irgacure 907” manufactured by Ciba Specialty Chemicals)
Sensitizer: 4,4′-bis (diethylamino) benzophenone (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.)
Organic solvent: cyclohexanone [Examples 1-7, Comparative Examples 1-3]
In the method shown below, each color dry coating film is prepared using each color resist, the luminance L _Outside and L _{Inside of} the orthogonal transmitted light, the luminance ratio L _Outside / L _Inside , and the radiance R _Outside of the orthogonal transmitted light, _RInside and the radiance ratio _ROutside / _RInside were measured.

In addition, color filters shown in Table 6 below were combined to produce a color filter by the following method, and the luminance L _outside and L _{inside of} the orthogonal transmitted light and the luminance ratio L _outside / L _inside were measured.

 Furthermore, a liquid crystal display device was produced using a color filter by the method described below, and the visibility of the liquid crystal panel during black display was evaluated.

[Preparation of dry coating film for measuring the brightness and radiance of orthogonal transmitted light]
Each color resist was coated on a glass substrate by spin coating, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature, and then exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Thereafter, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to prepare dry paint films for measuring the luminance of orthogonal transmitted light and radiance of each color paint film. The film thickness of the dried coating film was 2.0 μm in all cases.

[Production of color filter]
First, a red resist was applied to a glass substrate on which a black matrix had been formed in advance by spin coating, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature, and then exposed to ultraviolet rays through a photomask using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Further, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form a striped red filter segment on the substrate.

 Next, a green resist was similarly used to form a green filter segment, and further a blue resist was used to form a blue filter segment to obtain a color filter. The formed film thickness of each color filter segment was 2.0 μm.

[Production of liquid crystal display devices]
A transparent ITO electrode layer was formed on the color filter, and a polyimide alignment layer was formed thereon. A polarizing plate was formed on the other surface of this glass substrate. On the other hand, a TFT array and a pixel electrode were formed on one surface of another (second) glass substrate, and a polarizing plate was formed on the other surface.

 The two glass substrates prepared in this manner are opposed to each other so that the electrode layers face each other, and are aligned while keeping the distance between the two substrates constant using spacer beads, leaving a liquid crystal composition injection opening. The periphery was sealed with a sealant. A liquid crystal composition was injected from the opening, the opening was sealed, and a liquid crystal display device was produced.

 This liquid crystal display device was combined with a backlight unit to obtain a liquid crystal panel.

[L _Outside , L _Inside , L _Outside / L _Inside Measurement of Each Color Coating and Color Filter]
For each color coat and the color filter, using the measuring apparatus shown in FIG. 4, according to the operation sequence shown in FIG. _{5, L Outside,} L _Inside, it was measured _{L Outside /} L _Inside.

A color luminance meter ("BM-5A" manufactured by Topcon Co., Ltd.) 32 was used as the luminance meter, and the measurement was performed under the condition of 2 ° visual field. The light source has an emission spectrum as shown in FIG. 2, luminance = 1937 cd / m ² , chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301), color The thing of the characteristic of temperature = 6525K and chromaticity deviation duv = -0.0136 was used. The polarizing plate used was “NPF-SEG1224DU” manufactured by Nitto Denko Corporation. Note that the luminance measurement value when the color filter is outside the pair of polarizing plates arranged in the parallel Nicol state is L (P) L _Outside , and the luminance when the color filter is between the pair of polarizing plates arranged in the parallel Nicol state. The measured value is L (P) _Inside .

 The results are shown in Tables 5 and 6 below.

[Measurement of R _Outside , R _Inside , R _Outside / R _{Inside of} each color coating film]
Same as L _Outside , L _Inside , L _Outside / L _Inside except that it was measured using a spectral radiance meter (“CS-1000A” manufactured by Konica Minolta Co., Ltd.) as a luminance meter under the condition of 2 ° visual field. Then, R _Outside , R _Inside , R _Outside / R _Inside were measured for each color coating film. The results are shown in Table 5 below.

[Visibility when the LCD panel displays black]
The produced liquid crystal display device was displayed in black, and the amount of light leaked from the liquid crystal panel (orthogonal transmitted light; leaked light) was visually observed. The evaluation rank is as follows, and the results are shown in Table 6 below.

 A: No leakage light is observed and visibility is very good.

 ○: Slight light leakage is observed, but visibility is good.

 Δ: Leakage light is observed, but there is no problem in practical use.

 X: Leakage light is considerably observed and visibility is poor.

From Tables 5 and 6, the color filters obtained in Examples 1 to 7 have higher luminance L _Outside / L _{Inside of} orthogonal transmitted light and black display compared to the color filters obtained in Comparative Examples 1 to 3. It can be seen that the visibility is excellent.

It is explanatory drawing of the measuring method of the brightness | luminance of a color filter by the measuring apparatus which concerns on the 3rd Embodiment of this invention, and radiance. It is a graph which shows the emission spectrum of a backlight. It is a schematic sectional drawing which shows an example of the liquid crystal display device which concerns on the 2nd Embodiment of this invention provided with the color filter which concerns on the 1st Embodiment of this invention. It is a figure which shows the outline of the measuring apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows the operation | movement flow of the measuring apparatus which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device, 11, 21 ... Transparent substrate, 12 ... TFT array, 13, 23 ... Transparent electrode, 14, 24 ... Orientation layer, 15, 25 ... Polarizing plate, 22 ... Color filter, 30 ... Backlight unit, 31 ... Three-wavelength lamp, 32 ... Color luminance meter or spectral radiance meter, 33, 35 ... Polarizing plate, 34 ... Color filter (arranged on slide stage 39), 34 '... Color filter (arranged on slide stage 40) 36 ... Backlight light, 37 ... Backlight unit, 38 ... Orthogonal transmitted light (leakage light), 39 ... Slide stage, 40 ... Slide stage.

Claims (8)

In a color filter having red, green, and blue filter segments, the color filter is arranged between a pair of polarizing plates arranged in a crossed Nicol state, and the luminance when irradiated with light is L _Inside, and arranged in the same state A color filter satisfying the following formula (1) when the color filter is disposed outside the pair of polarizing plates and the luminance when irradiated with light is L _Outside .
L _Outside / L _Inside > 0.30 (1) The red filter segment is formed from a red coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof or a mixture thereof, and a red pigment, and formed from the red coloring composition. Is arranged between a pair of polarizing plates arranged in a crossed Nicol state, the luminance when irradiated with light is L (R) _Inside, and the red coating film is arranged outside the pair of polarizing plates arranged in the same state The color filter according to claim 1, wherein the following expression (2) is satisfied when the luminance when irradiated with light is L (R) _Outside .
L (R) _Outside / L (R) _Inside > 0.15 (2) The green filter segment is formed from a green coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof or a mixture thereof, and a green pigment, and formed from the green coloring composition Is arranged between a pair of polarizing plates arranged in a crossed Nicol state, the luminance when irradiated with light is L (G) _Inside, and the green coating film is arranged outside the pair of polarizing plates arranged in the same state The color filter according to claim 1, wherein the following expression (3) is satisfied when the luminance when irradiated with light is L (G) _Outside .
L (G) _Outside / L (G) _Inside > 0.40 (3) The blue filter segment is formed of a blue coloring composition containing a pigment carrier made of a transparent resin, a precursor thereof or a mixture thereof, and a blue pigment, and is formed from the blue coloring composition Is arranged between a pair of polarizing plates arranged in a crossed Nicol state, the luminance when irradiated with light is L (B) _Inside, and the blue coating film is arranged outside the pair of polarizing plates arranged in the same state The color filter according to any one of claims 1 to 3, wherein the following expression (4) is satisfied when the luminance when irradiated with light is L (B) _Outside .
L (B) _Outside / L (B) _Inside > 0.45 (4) The red, green and blue filter segments are formed from a red, green and blue coloring composition comprising a pigment carrier comprising a transparent resin, a precursor thereof or a mixture thereof; and a red, green and blue pigment; and The radiance at the maximum peak wavelength at 400 to 700 nm when the red, green and blue coating films formed from the colored compositions are arranged between a pair of polarizing plates arranged in a crossed Nicol state and irradiated with light _Are R (R) _Inside , R (G) _Inside , R (B) _Inside, and the red, green or blue coating film is placed outside the pair of polarizing plates arranged in the same state, and irradiated with light. When the radiance at the maximum peak wavelength is R (R) _Outside , R (G) _Outside , and R (B) _Outside , respectively, The color filter according to claim 1, wherein the color filter satisfies 5) to (7).
R (R) _Outside / R (R) _Inside > 0.18 (5)
R (G) _Outside / R (G) _Inside > 0.30 (6)
R (B) _Outside / R (B) _Inside > 0.70 (7)  The color filter according to any one of claims 2 to 5, wherein the primary particle diameter of the pigment contained in the coloring composition used for forming the red, green and blue filter segments is 40 nm or less.  A liquid crystal display device comprising the color filter according to claim 1. (A) A measuring device comprising a pair of polarizing plates, at least one of which can rotate in-plane, (B) a luminance meter, and (C) a light source, and means for accurately arranging the pair of polarizing plates in a crossed Nicols state And a means for holding the color filter between the pair of polarizing plates and a means for holding the color filter outside the pair of polarizing plates, wherein L _Inside , L _Outside , L _Inside / L A measuring apparatus capable of measuring _Outside , R (X) _Outside , R (X) _Inside , and R (X) _Outside / R (X) _Inside (X is R, G, or B).

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