JP2011095313A - Color filter - Google Patents

Abstract

A color filter capable of realizing high contrast and high color reproducibility, and a liquid crystal display device including the color filter.
A color filter comprising a plurality of color pixels including a yellow pixel, wherein the yellow pixel is a pixel having a thickness of less than 5 μm formed using a yellow composition containing at least a yellow pigment and a dye. The chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.550, 0.450), (0.400, 0.600), (0.350, 0.550), It is characterized by being located within a rectangle surrounded by (0.510, 0.430).
[Selection figure] None

Description

  The present invention relates to a color filter suitable for a color liquid crystal display device.

  In recent years, liquid crystal display devices have been evaluated for space saving, light weight, and power saving due to their thinness. Since its application has been extended to large-sized televisions and monitors, there is a demand for high transmittance, high color reproducibility, high saturation, and high contrast for color filters that determine the color characteristics of liquid crystal display devices. (See, for example, Patent Documents 1, 2, and 3).

  As a means for achieving high color reproduction, it is effective to add fourth, fifth, and sixth pixels to the color filter in addition to the red, green, and blue pixels. Patent Document 4 and Patent Document 5 add yellow, cyan, and magenta pixels in addition to red, green, and blue pixels, and Patent Document 6 adds cyan pixels. It proposes expansion of the color reproduction range. As the fourth pixel to be added to the red, green, and blue pixels, it is effective to use a yellow pixel that is advantageous in terms of increasing the luminance. By performing color reproduction with four color pixels, the color reproduction range can be expanded compared to a color filter composed of three colors, and by adding yellow having a higher transmittance than red, green and blue, Brightness of the liquid crystal display device can be increased.

JP 2001-194658 A JP 2002-214436 A JP 2005-316439 A JP 09-251160 A Japanese Patent No. 4170899 JP 2001-306003 A

However, in yellow coloring compositions, there is a trade-off relationship between saturation and contrast, i.e. yellow pigments with high contrast have low saturation, pigments with high saturation have low contrast, and high contrast and high saturation. It was difficult to achieve both.
The present invention has been made under the circumstances as described above, and a high-color reproducibility can be achieved by finding a yellow coloring composition with high contrast and high saturation and forming a yellow pixel with the composition. An object is to provide a simple color filter.

  In order to solve the above problems, a first aspect of the present invention is a color filter including a plurality of color pixels including a yellow pixel, wherein the yellow pixel includes at least (a) a colorant and (b) a photopolymerization. (C) a photopolymerization initiator, (d) a transparent resin, (e) a pixel formed using a yellow composition containing a solvent, and (a) a yellow pigment CI Pigment Yellow in the colorant A color filter characterized by comprising at least one of 138, 139, 150, and 185 and a dye, and (a) the weight ratio of the dye in the colorant is not less than 0.01 and less than 0.4. It is.

According to a second aspect of the present invention, the spectral transmittance of the yellow pixel is such that the transmittance at a wavelength of 650 nm or more is 90% or more, and the transmittance at a wavelength of 450 nm or less is 10% or less. 1 as a color filter.

  In the third aspect of the present invention, the chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram of the chromaticity of the yellow pixel are (0.550, 0.450), (0.400, 0). .600), (0.350, 0.550), and (0.510, 0.430). The color filter according to claim 1, wherein the color filter is located within a square.

  A fourth aspect of the present invention is the color filter according to any one of claims 1 to 3, wherein a contrast ratio of the yellow pixel is 10,000 or more.

  A fifth aspect of the present invention is the color filter according to any one of claims 1 to 4, wherein the yellow pixel has a thickness of less than 5 μm.

  According to the present invention, it is possible to obtain a color filter capable of realizing high contrast and high color reproducibility by forming yellow pixels using a yellow composition that achieves both high contrast and high saturation. it can. Therefore, a liquid crystal display device provided with this color filter has high contrast and high color reproducibility.

The figure which shows the range of the chromaticity coordinate (x, y) in the XYZ color system chromaticity diagram of the yellow pixel used for the color filter which concerns on one Embodiment of this invention. 1 is a diagram illustrating a configuration of a liquid crystal display device including a color filter according to an embodiment of the present invention. The figure for demonstrating the measuring method of contrast. The characteristic view which shows the emission spectrum of a backlight.

Embodiments of the present invention will be described below.
The color filter which concerns on one Embodiment of this invention comprises the colored pixel of multiple colors including a yellow pixel. Examples of pixels other than yellow pixels include red pixels, green pixels, and blue pixels. These colored pixels are formed using a colorant, a photopolymerizable monomer, a photopolymerization initiator, a transparent resin, and a solvent.

  As the colorant contained in the coloring composition, organic or inorganic pigments and dyes can be used alone or in admixture of two or more. Among the colorants, pigments having high color developability and high heat resistance, particularly those having high heat decomposition are preferable.

  The yellow pixel used in the color filter of the present invention is a yellow composition containing at least (a) a colorant, (b) a photopolymerizable monomer, (c) a photopolymerization initiator, (d) a transparent resin, and (e) a solvent. A pixel formed using an object, comprising: (a) at least one or more of yellow pigments CI Pigment Yellow 138, 139, 150, and 185 in the colorant; and (a) a dye in the colorant The weight ratio is 0.01 or more and less than 0.4.

  The yellow pixel included in the color filter of the present invention is a pixel having a film thickness of less than 5 μm formed using a yellow composition containing a dye together with a yellow pigment, and the chromaticity in the XYZ color system chromaticity diagram. The coordinates (x, y) are (0.550, 0.450), (0.400, 0.600), (0.350, 0.550), (0.510, 0.430).

  In particular, the chromaticity coordinates (x, y) in the XYZ color coordinate diagram are (0.550, 0.450), (0.480, 0.520), (0.430, 0.490), (0 .510, 0.430). This range is a region rich in color expression by yellow pixels. In addition, this is a region having high saturation. When the film thickness of the yellow pixel is 5 μm or more, shape defects such as overhang are likely to occur. More preferably, it is less than 4 μm.

  As for the spectral transmittance of such a yellow pixel, the transmittance at a wavelength of 650 nm or more is 90% or more, and the transmittance at a wavelength of 450 nm or less is 10% or less.

  As described above, a yellow pixel formed using a yellow composition containing both a yellow pigment and a dye and exhibiting chromaticity or spectral transmittance as described above has high contrast and saturation, for example, red, A color filter obtained by adding such yellow pixels to green and blue pixels can realize high contrast and high color reproducibility.

  In other words, the yellow pigment alone cannot achieve both contrast and saturation, but by using a yellow composition in which a yellow pigment with low saturation and high contrast is mixed with a yellow dye with high saturation and high contrast. Therefore, it is possible to obtain yellow pixels that satisfy high saturation and maintain necessary contrast.

  CI Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35 as yellow pigments used in the yellow coloring composition 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, 176 177,179,180,181,182,185,187,188,193,194,198,199,213,214, and the like. Among these, C.I. Pigment Yellow 138, 139, 150, and 185 can be preferably used. In addition, 2 or more types of the above yellow pigments can be mixed and used.

BET specific surface area of the yellow pigment contained in the yellow coloring composition, is preferably ^90m 2 / g or more, more preferably ^{95 m} 2 / g or more, further preferably 100 m ² / g or more. Moreover, it is preferable that the specific surface area by BET method of a yellow pigment is 140 m < ² > / g or less.
When the specific surface area of the yellow pigment is smaller than the lower limit value, the luminance and contrast ratio of the color filter are lowered. Further, when the specific surface area of the yellow pigment is larger than the upper limit value, it is difficult to disperse the pigment, and it becomes difficult to maintain the stability as the coloring composition and to secure the fluidity. As a result, the luminance and contrast ratio characteristics of the color filter deteriorate.

The dye used in the coloring composition can be used without particular limitation as long as it is an organic solvent-soluble dye, and can be selected from conventionally known dyes for use in color filters.
For example, Japanese Patent Application Laid-Open No. 64-90403, Japanese Patent Application Laid-Open No. 64-91102, Japanese Patent Application Laid-Open No. 1-94301, Japanese Patent Application Laid-Open No. 6-11614, Japanese Patent No. 2592207, US Pat. No. 4,808,501. Specification, US Pat. No. 5,667,920, US Pat. No. 5,059,500, JP-A-5-333207, JP-A-6-35183, JP-A-6-51115 And dyes described in JP-A-6-194828.

  Examples of these dyes include acid dyes, oil-soluble dyes, disperse dyes, reactive dyes, and direct dyes. For example, azo dyes, benzoquinone dyes, naphthoquinone dyes, anthraquinone dyes, cyanine dyes, squarylium dyes, croconium dyes, merocyanine dyes, stilbene dyes, diarylmethane dyes, triarylmethane dyes, fluorans Dyes, spiropyran dyes, phthalocyanine dyes, indigo dyes, fulgide dyes, nickel complex dyes, and azulene dyes. Specific examples of color index numbers include the following. C. I. Solvent Yellow 2, 3, 7, 12, 13, 14, 16, 18, 19, 21, 25, 25: 1, 27, 28, 29, 30, 33, 34, 36, 42, 43, 44, 47, 56, 62, 72, 73, 77, 79, 81, 82, 83, 83: 1, 88, 89, 90, 93, 94, 96, 98, 104, 107, 114, 116, 117, 124, 130, 131, 133, 135, 141, 143, 145, 146, 157, 160: 1, 161, 162, 163, 167, 169, 172, 174, 175, 176, 179, 180, 181, 182, 183, 184, 185, 186, 187, 189, 190, 191, C.I. I. Solvent Orange 1, 2, 3, 4, 5, 7, 11, 14, 20, 23, 25, 31, 40: 1, 41, 45, 54, 56, 58, 60, 62, 63, 70, 75, 77, 80, 81, 86, 99, 102, 103, 105, 106, 107, 108, 109, 110, 111, 112, 113, C.I. I. SolventRed 1, 2, 3, 4, 8, 16, 17, 18, 19, 23, 24, 25, 26, 27, 30, 33, 35, 41, 43, 45, 48, 49, 52, 68, 69, 72, 73, 83: 1, 84: 1, 89, 90, 90: 1, 91, 92, 106, 109, 110, 111, 118, 119, 122, 124, 125, 127, 130, 132, 135, 141, 143, 145, 146, 149, 150, 151, 155, 160, 161, 164, 164: 1, 165, 166, 168, 169, 172, 175, 179, 180, 181, 182, 195, 196, 197, 198, 207, 208, 210, 212, 214, 215, 218, 222, 223, 225, 227, 229, 230, 233, 234, 23 , 236,238,239,240,241,242,243,244,245,247,248, C. I. Acid Red 6, 11, 26, 60, 88, 111, 186, 215, C.I. I. Acid Yellow 17, 23, 25, 36, 38, 42, 44, 72, 78, C.I. I. Basic Red 1, 2, 13, 14, 22, 27, 29, 39, C.I. I. Basic Yellow 11, 23, 25, 28, 41, C.I. I. DirectRed 4, 23, 31, 75, 76, 79, 80, 81, 83, 84, 149, 224, C.I. I. Direct Yellow 26, 27, 28, 33, 44, 50, 86, 142, C.I. I. Direct Orange 26, 29, 34, 37, 72, C.I. I. SulfurRed 5, 6, 7, C.I. I. Sulfur Yellow 4, C.I. I. VatRed 13, 21, 23, 28, 29, 48, C.I. I. Vat Yellow 2, 12, 20, 33, C.I. I. Vat Orange 2, 5, 11, 15, 18, 20, C.I. I. Reactive Red 8, 22, 46, 120, C.I. I. Reactive Yellow 1, 2, 4, 14, 16, C.I. I. Reactive Orange 1, 4, 7, 13, 16, 20, C.I. I. Disperse Red 4, 11, 54, 55, 58, 65, 73, 127, 129, 141, 196, 210, 229, 354, 356, C.I. I. Disperse Yellow 3, 4, 5, 7, 23, 33, 42, 60, 64, C.I. I. Disperse Orange 13, 29, 30.

These dyes can be used alone or in combination of two or more in order to develop a desired spectral spectrum. Among these, C.I. which is particularly soluble in an organic solvent and has high coloring property. I. Solvent Yellow 21, 62, 79, 83, 83: 1, 93, 151, C.I. I. Solvent Orange 60, 62, C.I. I. SolventRed 8, 92, 111, 124, 132 are preferred.

  The weight ratio of the dye in the yellow coloring composition is desirably 0.01 or more and less than 0.4. If it is less than 0.01, it is necessary to make the color pixels very thick in order to form colored pixels having a sufficient color as a color filter, so that pixel formation is difficult and productivity is also deteriorated. There are practical difficulties. On the other hand, if the concentration exceeds 0.4, the concentration is too high, so that the dye may not be sufficiently dissolved, and crystals may be deposited. There is also a risk that the dye may precipitate when the solvent is dried.

  Pigments and dyes can be used as the colorant used in the coloring composition for forming pixels other than yellow pixels, for example, red pixels, green pixels, and blue pixels. Specific examples of the pigments and dyes used are shown below.

Examples of the dye used in the coloring composition include C.I. I. Solvent Yellow 2, 3, 7, 12, 13, 14, 16, 18, 19, 21, 25, 25: 1, 27, 28, 29, 30, 33, 34, 36, 42, 43, 44, 47, 56, 62, 72, 73, 77, 79, 81, 82, 83, 83: 1, 88, 89, 90, 93, 94, 96, 98, 104, 107, 114, 116, 117, 124, 130, 131, 133, 135, 141, 143, 145, 146, 157, 160: 1, 161, 162, 163, 167, 169, 172, 174, 175, 176, 179, 180, 181, 182, 183, 184, 185, 186, 187, 189, 190, 191, C.I. I. Solvent Orange 1, 2, 3, 4, 5, 7, 11, 14, 20, 23, 25, 31, 40: 1, 41, 45, 54, 56, 58, 60, 62, 63, 70, 75, 77, 80, 81, 86, 99, 102, 103, 105, 106, 107, 108, 109, 110, 111, 112, 113, C.I. I. SolventRed 1, 2, 3, 4, 8, 16, 17, 18, 19, 23, 24, 25, 26, 27, 30, 33, 35, 41, 43, 45, 48, 49, 52, 68, 69, 72, 73, 83: 1, 84: 1, 89, 90, 90: 1, 91, 92, 106, 109, 110, 118, 119, 122, 124, 125, 127, 130, 132, 135, 141, 143, 145, 146, 149, 150, 151, 155, 160, 161, 164, 164: 1, 165, 166, 168, 169, 172, 175, 179, 180, 181, 182, 195, 196, 197, 198, 207, 208, 210, 212, 214, 215, 218, 222, 223, 225, 227, 229, 230, 233, 234, 235, 23 , 238,239,240,241,242,243,244,245,247,248, C. I. SolventViolet 2, 8, 9, 11, 13, 14, 21, 21: 1, 26, 31, 36, 37, 38, 45, 46, 47, 48, 49, 50, 51, 55, 56, 57, 58, 59, 60, 61, C.I. I. Solvent Blue 2, 3, 4, 5, 7, 18, 25, 26, 35, 36, 37, 38, 43, 44, 45, 48, 51, 58, 59, 59: 1, 63, 64, 67, 68, 69, 70, 78, 79, 83, 94, 97, 98, 100, 101, 102, 104, 105, 111, 112, 122, 124, 128, 129, 132, 136, 137, 138, 139, 143, C. I. Solvent Green 1, 3, 4, 5, 7, 28, 29, 32, 33, 34, 35, C.I. I. Solvent Brown 1, 3, 4, 5, 12, 20, 22, 28, 38, 41, 42, 43, 44, 52, 53, 59, 60, 61, 62, 63, C.I. I. Solvent Black 3, 5, 5: 2, 7, 13, 22, 22: 1, 26, 27, 28, 29, 34, 35, 43, 45, 46, 48, 49, 50, C.I. I. Acid Red 6, 11, 26, 60, 88, 111, 186, 215, C.I. I. AcidGreen 25, 27, C.I. I. Acid Blue 22, 25, 40, 78, 92, 113, 129, 167, 230, C.I. I. Acid Yellow 1
7, 23, 25, 36, 38, 42, 44, 72, 78, C.I. I. Basic Red 1, 2, 13, 14, 22, 27, 29, 39, C.I. I. BasicGreen 3, 4, C.I. I. BasicBlue 3, 7, 9, 17, 41, 66, C.I. I. BasicViolet 1, 3, 18, 39, 66, C.I. I. Basic Yellow 11, 23, 25, 28, 41, C.I. I. DirectRed 4, 23, 31, 75, 76, 79, 80, 81, 83, 84, 149, 224, C.I. I. DirectGreen 26, 28, C.I. I. DirectBlue 71, 78, 98, 106, 108, 192, 201, C.I. I. DirectViolet 51, C.I. I. Direct Yellow 26, 27, 28, 33, 44, 50, 86, 142, C.I. I. Direct Orange 26, 29, 34, 37, 72, C.I. I. SulfurRed 5, 6, 7, C.I. I. SulfurGreen 2, 3, 6, C.I. I. SulfurBlue 2, 3, 7, 9, 13, 15, C.I. I. Sulfur Violet 2, 3, 4, C.I. I. Sulfur Yellow 4, C.I. I. VatRed 13, 21, 23, 28, 29, 48, C.I. I. VatGreen 3, 5, 8, C.I. I. VatBlue 6, 14, 26, 30, C.I. I. VatViolet 1, 3, 9, 13, 15, 16, C.I. I. Vat Yellow 2, 12, 20, 33, C.I. I. Vat Orange 2, 5, 11, 15, 18, 20, C.I. I. Azoic Coupling Component 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 32, 37, 41, 48, C.I. I. Reactive Red 8, 22, 46, 120, C.I. I. Reactive Blue 1, 2, 7, 19, C.I. I. Reactive Violet 2, 4, C.I. I. Reactive Yellow 1, 2, 4, 14, 16, C.I. I. Reactive Orange 1, 4, 7, 13, 16, 20, C.I. I. Disperse Red 4, 11, 54, 55, 58, 65, 73, 127, 129, 141, 196, 210, 229, 354, 356, C.I. I. DisperseBlue 3, 24, 79, 82, 87, 106, 125, 165, 183, C.I. I. DisperseViolet 1, 6, 12, 26, 27, 28, C.I. I. Disperse Yellow 3, 4, 5, 7, 23, 33, 42, 60, 64, C.I. I. Disperse Orange 13, 29, 30 are listed.

As a red pigment, CI Pigment Red 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 17, 18, 22, 23, 31, 37, 38, 41, 42, 48: 1, 48: 2, 48: 3, 48: 4, 49, 50, 52, 53, 54, 57, 58, 60, 63, 64, 68, 81: 1, 81: 2, 81: 3, 88, 90, 97, 112, 114, 115, 122, 123, 133, 139, 144, 146, 147, 149, 150, 151, 166, 168, 170, 171, 175, 176, 177, 178, 179, 180, 184, 185, 187, 188, 190, 192, 194, 200, 202, 207, 208, 209, 210, 214, 215, 216, 217, 220, 221, 223, 224, 226, 227, 228 May be used red pigments such 240,242,243,245,246,247,254,255,264,272, CI Pigment
Red 177, 242 and 254 are preferred. CI Pigment Orange 1, 2, 5, 13, 15, 16, 17, 18, 19, 31, 34, 36, 38, 40, 42, 43, 51, 52, 55, 59, 60, 61, 62, 71, 73 and the like, and CI Pigment Orange 38, 64, 71 are preferable.

  As the green pigment, green pigments such as C.I. Pigment Green 2, 7, 8, 10, 36, 37, 58 can be used, and C.I. Pigment Green 7, 36, 58 is preferable.

  Examples of the blue pigment include CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 19, 22, 56, 60, 64, 80, and the like. CI Pigment Blue 15: 3 and 15: 6 are preferred.

  As a purple pigment, CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, and 50 are used in combination with a purple pigment such as CI Pigment Violet 23. be able to.

  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.

  These dyes and pigments can be used alone or in combination of two or more in order to develop a desired spectral spectrum.

The pigment contained in the coloring composition is preferably finely processed in order to achieve high brightness and high contrast of the color filter, and preferably has a large specific surface area. it is preferably 90m ² / g or more, more preferably ^{95 m} 2 / g or more, further preferably 100 m ² / g or more. Moreover, it is preferable that the specific surface area by BET method of a pigment is 140 m < ² > / g or less.

  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 of precipitating a pigment (referred to as a precipitation method), a method of producing a pigment having a desired specific surface area at the time of 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 the pigment contained in the colored composition used in the present invention.
In the grinding method, the pigment is mechanically kneaded with a grinding agent such as water-soluble inorganic salt such as salt and a water-soluble organic solvent that does not dissolve it using a ball mill, sand mill, or kneader (hereinafter, this process is salted). In this method, 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. 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 to make 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, but examples include strongly acidic solvents such as concentrated sulfuric acid, polyphosphoric acid, 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 handling becomes bad. Conversely, if the amount is too large, the treatment efficiency of the pigment is lowered. 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 pigment aggregation associated with the specific surface area control, the following dispersion aids such as dye derivatives, resin-type pigment dispersants and surfactants may 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 a vat dye, such as a flavantron, perinone, perylene, or indanthrone, is reduced with alkaline hydrosulfite, the quinone group becomes a 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 dye carrier contained in the color filter coloring composition of the present invention disperses the dye 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 its precursor includes a monomer or an oligomer that is cured by irradiation with radiation to form a transparent resin. Alternatively, two or more kinds can be mixed and used.

The dye 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 dye in the coloring composition. Moreover, when using the mixture of transparent resin and its precursor as a pigment | dye carrier, transparent resin is 20-400 weight part with respect to 100 weight part of pigment | dyes in a coloring composition, Preferably it is 50-250 weight part. 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 colored composition.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. 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.

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 Til) -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 pigment | dyes 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, tris (2-hydroxyethyl) isocyanurate, trimercaptopropionic acid, 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 dye in the coloring composition.

Furthermore, the coloring composition for a color filter of the present invention is obtained by sufficiently dispersing a dye in a dye carrier and applying it on a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm. A solvent can be included to facilitate the formation of the segments.
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.

  A solvent can be used in the quantity of 800-4000 weight part with respect to 100 weight part of pigment | dyes in a coloring composition, Preferably it is 1000-2500 weight part.

  The coloring composition is a dispersion of three or more roll mills, two roll mills, sand mills, kneaders, attritors, etc. in a dye carrier and an organic solvent together with one or two or more dyes as required. It can be produced by finely dispersing using means. Moreover, the coloring composition containing 2 or more types of pigment | dyes can also mix and manufacture what each disperse | distributed separately in the pigment | dye carrier and the organic solvent separately. When the pigment is dispersed in the pigment carrier and the organic solvent as a pigment, a dispersion aid such as a resin-type pigment dispersant, a surfactant, a pigment derivative, or a dye derivative can be appropriately contained. Since the dispersion aid is excellent in the dispersion of the pigment and has a large effect of preventing re-aggregation of the pigment after dispersion, a coloring composition obtained by dispersing the pigment in the pigment carrier and the organic solvent using the 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 dispersant has a dye-affinity part that has the property of adsorbing to the dye and a part that is compatible with the dye carrier, and works to adsorb to the dye and stabilize the dispersion of the dye on the dye carrier. It is something to do. 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.

  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 pigment derivative and the dye derivative are compounds in which a substituent is introduced into an organic dye, and those close to the hue of the dye to be used are preferable, but those having different hues may be used if the addition amount is small. Examples of the coloring matter used as a base include azo series, phthalocyanine series, quinacridone series, anthraquinone series, perylene series, thidium moss series, dioxane series, and metal complex salts. As the substituent used for introduction, a derivative having at least one substituent selected from substituents such as a hydroxyl group, a carboxyl group, a sulfone group, a carbonamide group, and a sulfonamide group is used. Also included are pale yellow aromatic polycyclic compounds such as naphthalene and anthraquinone that are not generally called dyes. 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. Moreover, in order to improve adhesiveness with a transparent substrate, adhesion improving agents, such as a silane coupling agent, can also be contained.

  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 their methyl ethers, phosphines such as tributylphosphine, trioctylphosphine, tricyclohexylphosphine, triphenylphosphine and tribenzylphosphine Compounds, phosphine oxide compounds such as trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphite, trisnonyl 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 coloring 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 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 dye 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.

  In the color filter according to the present embodiment, after forming a black matrix on a transparent substrate, each color-colored composition layer is provided in a region divided into the black matrix by a printing method or a photolithography method. It can be obtained by forming a pixel.

  As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and 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.

  FIG. 2 shows a liquid crystal display device including a color filter according to an embodiment of the present invention. In FIG. 2, a liquid crystal display device 10 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 arranged to be spaced apart from each other. Liquid crystal (LC) is enclosed.

  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 present embodiment is formed on the inner surface of the second transparent substrate 21. The red, green and blue pixels 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. Note that a backlight unit 30 including a lamp 31 is provided below the polarizing plate 15.

(Pigment adjustment)
The pigments used in Examples and Comparative Examples are shown in Table 1. Table 2 shows the dispersants used in Examples and Comparative Examples.

[Adjustment of acrylic resin solution]
The 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, and 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. A resin solution was obtained. The weight average molecular weight of the acrylic resin was about 40,000.

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

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

[Adjustment of dye solution]
Table 4 shows the dyes used in Examples and Comparative Examples.

  A mixture having the composition (weight ratio) shown in Table 5 was uniformly stirred and mixed, and then filtered through a 5 μm filter to prepare a dye solution.

[Adjustment of colored composition (hereinafter referred to as resist)]
Next, the pigment dispersion, the dye solution, and the following composition prepared above were stirred and mixed so as to be uniform at the composition (weight ratio) shown in Table 6, and then filtered through a 1 μm filter to obtain each color resist. .

The monomers, photopolymerization initiator, sensitizer and organic solvent used are described below.
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

[Preparation of yellow pixel dry coating]
A yellow composition prepared by mixing the components having the above composition was applied to 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 subjected to ultraviolet exposure using an ultrahigh pressure mercury lamp. Then, it post-baked for 40 minutes at 230 degreeC in clean oven, and as shown in following Table 7, the dry coating film (Examples 1-7, Comparative Examples 1-5) of 12 types of yellow pixels was produced. .
These coating film samples were evaluated as follows.

(Measurement of chromaticity of parallel transmitted light)
The chromaticity coordinate of the obtained sample was measured using a microspectrophotometer OSP-2000 (manufactured by Olympus Optical Co., Ltd.) under the condition of 2 ° visual field. The backlight used for the measurement is a B-LED + R · G phosphor backlight that combines white light with a blue LED, a red light emitting phosphor, and a green light emitting phosphor, and exhibits an emission spectrum as shown in FIG. A thing was used. The obtained chromaticity measurement results are shown in Table 7.

[Measurement of contrast ratio]
First, as shown in FIG. 3A, the polarizing plates 2 and 3 were arranged in front of and behind the sample 4 with their polarization axes parallel to each other. A backlight 6 is irradiated from the side of one polarizing plate 3, and the luminance Lp (luminance of parallel transmitted light) of the light 7 transmitted through the other polarizing plate 2 is measured with a color luminance meter BM-5A (manufactured by Topcon Corporation) 1. Used and measured under the condition of 2 ° visual field (CIE 1931 color system).
Next, as shown in FIG. 3 (b), the polarization axes of the polarizing plates 2 and 3 are orthogonal to each other, the backlight 6 is irradiated from the side of one polarizing plate 3, and the other polarizing plate 2 is transmitted. The luminance Lc of the light 8 (the luminance of the orthogonal transmitted light) was measured with the color luminance meter 1.

The contrast ratio Lp / Lc was calculated using the measured values obtained by the above method.
The backlight has an emission spectrum as shown in FIG. 5, luminance = 1937 cd / m 2, and chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301). The one having the characteristics of color temperature = 6520K and chromaticity deviation duv = −0.0136 was used. Further, NPF-SEG1224DU (manufactured by Nitto Denko Corporation) was used as the polarizing plate.
These results are shown in Table 7 below.

[Measurement of film thickness]
The film thickness of the obtained sample was measured using a stylus type film thickness measuring device Dektak OSP-1100 (manufactured by ULVAC). The results obtained are shown in Table 7.

[Evaluation of foreign matter]
The obtained sample was observed under transmitted light to evaluate the presence of foreign matters such as precipitates. The results obtained are shown in Table 7.

  From Table 7, the following can be understood. That is, the yellow pixel (Comparative Example 1) obtained using the yellow composition (YP-1) containing only Y-1 has a good contrast of 8000 or more, but the chromaticity is as shown in FIG. This is outside the scope of the present invention and has low saturation. Further, the yellow pixel (Comparative Example 2) obtained using the yellow composition (YP-2) containing only Y-2 has a chromaticity within the range of the present invention as shown in FIG. The degree is good, but the contrast is as low as 2850. Further, the yellow pixel (Comparative Example 3) obtained by using the yellow composition (YP-3) obtained by adding Y-2 (20 parts by weight) to Y-1 (80 parts by weight) has a chromaticity of FIG. As shown in FIG. 1, the contrast is low, less than 10,000, within the scope of the present invention.

On the other hand, among the yellow compositions in which the dyes y-1, r-1, r-2, o-1 are added to Y-1, the yellow dye content in the pigment is 0.01 or more and less than 0.4. The yellow pixels (Examples 1 to 7) obtained using the compositions (YP-5, 7 to 12) have chromaticity within the range of the present invention as shown in FIG. In addition, the contrast is as high as 10,000 or more.
In addition, the yellow pixel (Comparative Examples 4 and 5) obtained using the yellow composition (YP-4, 6) containing Y-1 and y-1 or Y-1 and r-1 has chromaticity, As shown in FIG. 1, although it is within the scope of the present invention, foreign matter is generated, and for YP-6 (Comparative Example 5), the contrast is as low as less than 10,000 and the dye content is inappropriate. It can be seen that it is.
Next, color filters were produced by the following method using combinations of the color resists shown in Table 8.

[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, after cooling the substrate to room temperature, ultraviolet rays were exposed 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, using a green resist, form a green filter segment in the same way, then use a blue resist to form a blue filter segment, and then use a yellow resist to form a yellow filter segment to obtain a color filter. It was.

[Production of liquid crystal display devices]
A transparent ITO electrode layer was formed on the obtained 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 thus prepared face each other so that the electrode layers face each other, and are aligned using spacer beads while keeping the distance between both substrates constant, and the periphery is left so as to leave an opening for injecting the liquid crystal composition. Sealed with a sealant. A liquid crystal composition was injected from the opening to seal the opening. The liquid crystal display device thus produced was combined with a backlight unit to obtain a liquid crystal panel.

[Backlight]
As the backlight, a B-LED + R · G phosphor backlight that exhibits white by combining a blue LED, a red light emitting phosphor, and a green light emitting phosphor, and that exhibits an emission spectrum as shown in FIG. 4 was used. .

The following evaluation was performed about the color filter obtained by the Example and the comparative example.
[Evaluation of color reproduction area]
NTSC ratio of the color filter when illuminated using a B-LED + R / G phosphor backlight source using the produced color filter (standard system defined by the US National Television System Committee (NTSC)) A rectangle with respect to the standard value area, assuming that the area of the triangle of the three RGB colors defined by the three primary colors, red (0.67, 0.33), green (0.21, 0.71), and blue (0.14, 0.08) is 100) The area ratio was measured. The evaluation results are shown in Table 8.

[Evaluation of contrast ratio]
The contrast ratio of the color filter was evaluated using the produced color filter. The evaluation method was performed in the same manner as the dry paint film for yellow pixels. The evaluation results are shown in Table 8.
From the results of Table 8, by including dyes y-1, r-1, r-2, o-1 in the pigment in the yellow composition component of the color filter in an amount of 0.01 to less than 0.4 (Examples 8 to 14) It was found that the NTSC ratio was improved and the brightness and contrast were increased. On the other hand, the color filters using the yellow composition component that does not contain a dye (Comparative Examples 6 to 9) resulted in a low NTSC ratio and contrast. Furthermore, a color filter using a yellow composition component with a dye added in a weight ratio of 0.4 or more (Comparative Examples 10 and 11) shows a high contrast and NTSC ratio, but foreign matter is present in the yellow pixel. This occurs and lacks quality as a color filter.

DESCRIPTION OF SYMBOLS 1 ... Color luminance meter 2, 3, 15 ... Polarizing plate 6 ... Backlight 7, 8 ... Light 10 ... Liquid crystal display device 11, 21 ... Transparent substrate 12 ... TFT (thin film transistor) array 13, 23 ... Transparent electrode layers 14, 24 ... Alignment layers 15 and 25 ... Polarizing plate 22 ... Color filter 30 ... Backlight unit 31 ... Lamp

Claims (5)

  A color filter comprising a plurality of color pixels including a yellow pixel, wherein the yellow pixel comprises at least (a) a colorant, (b) a photopolymerizable monomer, (c) a photopolymerization initiator, and (d) a transparent resin. (E) a pixel formed using a yellow composition containing a solvent, wherein (a) at least one of yellow pigments CI Pigment Yellow 138, 139, 150, and 185 and a dye in a colorant And (a) a color filter in which the weight ratio of the dye in the colorant is 0.01 or more and less than 0.4.   2. The color filter according to claim 1, wherein the spectral transmittance of the yellow pixel is 90% or more at a wavelength of 650 nm or more and 10% or less at a wavelength of 450 nm or less.   The chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram of the chromaticity of the yellow pixel are (0.550, 0.450), (0.400, 0.600), (0.350, 2. The color filter according to claim 1, wherein the color filter is located within a square surrounded by (0.550) and (0.510, 0.430).   The color filter according to any one of claims 1 to 3, wherein a contrast ratio of the yellow pixel is 10,000 or more.   The color filter according to claim 1, wherein the yellow pixel has a thickness of less than 5 μm.

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