JPH11217514A - Red paste for color filters, and color filters and liquid crystal display devices using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To obtain a red filter having both high transmittance and high color purity by effectively utilizing a bright line of a backlight. A red paste for a color filter comprising a pigment, a polymer, and a solvent as main components, the pigment containing 5-98% by weight of Pigment Red PR-254.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a red paste for a color filter, a color filter using the same, and a liquid crystal display device.

[0002]

2. Description of the Related Art At present, a pigment dispersion method is mainly used for producing a color filter used in a liquid crystal display device or the like. Examples of the pigment dispersion method include a photosensitive acrylic method and a non-photosensitive polyimide method.

A color paste (non-photosensitive polyimide method) in which a pigment is dispersed in a polyamic acid solution will be described as an example of a color paste used in the production of a color filter by a pigment dispersion method (for example, JP-A-60-18).
4202, JP-A-60-184203, JP-A-61-180203).

The production of a color filter using a color paste in which a pigment is dispersed in a solution of a polyamic acid is disclosed in, for example, JP-A-60-247603 and JP-A-61-147603.
This is carried out by the following steps described in JP-A-77804. First, the color paste (for example, red)
And then dried to form a polyimide precursor colored film. A positive photoresist is applied on the polyimide precursor colored film to form a photoresist film. A mask is placed on the photoresist film and irradiated with ultraviolet light using an exposure device. After the exposure, the photoresist coating and the polyimide precursor colored coating are simultaneously etched with an alkaline developer for a positive photoresist. After the etching, the unnecessary photoresist film is removed. After that, the polyimide precursor is converted into polyimide by heat treatment. In this way, after forming a pattern of one color polyimide colored film on the substrate,
A color paste of another color (for example, green) is applied thereon, and through the same process, a pattern of a two-color polyimide coloring film is formed on the substrate. When this is repeated once again, a pattern of three colored polyimide films of red, green and blue is obtained.

[0005] Among the color pastes for the pigment dispersion method color filter used in this manner, a red pigment and a yellow pigment are used as pigments in a red filter paste, that is, a red paste.

Conventionally, Pigment Red PR-177 has been used as the red pigment. The yellow pigment is used to suppress the light transmission of the red pigment in the vicinity of 400 nm to 500 nm and satisfy the color characteristics required as a color filter.

However, the conventional red paste for a color filter, regardless of the photosensitive acrylic method or the non-photosensitive polyimide method, has high transmittance and high color purity that satisfy the color characteristics required for a liquid crystal display device. It was difficult to provide a compatible red filter.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is an object of the present invention to efficiently utilize the bright lines of the backlight of a liquid crystal display device. An object of the present invention is to provide a red paste for a color filter, which provides a red filter having both transmittance and high color purity.

[0009]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This is achieved by a color filter red paste containing a pigment, a polymer, and a solvent as main components, wherein the pigment contains 2 to 98% by weight of Pigment Red PR-254.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a red paste for a color filter containing Pigment Red PR-254 as a pigment.

The constitution of the present invention is effective regardless of the pigment dispersion method in general, that is, the photosensitive acrylic method, the non-photosensitive polyimide method and the like.

Next, the components of the present invention will be described.

In the present invention, the intended red color is achieved by using Pigment Red PR-254 as the red pigment. At this time, as long as the color characteristics are not impaired,
Other red pigments may be added. Examples of other typical red pigments include Pigment Red (PR-) 9, 97, 1
22, 123, 144, 149, 166, 168, 17
7, 180, 192, 215, 216, 224 and the like. In the present invention, various pigments can be used without being limited to these. If necessary, the pigment may be one which has been subjected to a surface treatment such as a rosin treatment, an acidic group treatment, a basic treatment, and a pigment derivative treatment.

In order to satisfy the color characteristics required for a color filter, it is necessary to mix and mix an orange pigment and / or a yellow pigment.

As typical examples of orange pigments, Pigment Orange (PO-) 13, 31, 36, 38, 40, 4
2, 43, 51, 55, 59, 61, 64, 65, 71
And the like. In the present invention, various pigments can be used without being limited to these. Examples of typical yellow pigments include Pigment Yellow (PY-) 12,
13, 14, 17, 20, 24, 83, 86, 93, 9
4, 109, 110, 117, 125, 137, 13
8, 139, 147, 148, 153, 154, 16
6, 173, 185 and the like. In the present invention, various pigments can be used without being limited to these.
If necessary, the pigment may be one which has been subjected to a surface treatment such as a rosin treatment, an acidic group treatment, a basic treatment, and a pigment derivative treatment.

However, in the red paste for a color filter of the present invention, it is preferable to use an orange pigment from the viewpoints of color characteristics, dispersibility, heat resistance and the like. As the orange pigment, a naphthol type or a diketopyrrolo It is preferable to use a pyrrole type. Among them,
For naphthols, Pigment Orange PO-3
As for diketopyrrolopyrrole, it is more preferable to use Pigment Orange PO-71 from the viewpoint of easy availability.

Pigment Red PR-254 and an orange pigment are mixed and toned, whereby a red filter satisfying the color characteristics required for a color filter and having both high transmission and high color purity can be obtained. .

In this case, Pigment Red P in all pigments
The weight ratio of R-254 is preferably 5 to 95%, and the weight ratio of the orange pigment is preferably 5 to 95%. When Pigment Orange PO-38 is used as the orange pigment, the weight ratio of Pigment Red PR-254 is preferably More preferably, the weight ratio of Pigment Orange PO-38 is 30 to 95%. When Pigment Orange PO-71 is used as the orange pigment, Pigment Red PR
More preferably, the weight ratio of -254 is 40 to 95%, and the weight ratio of Pigment Orange PO-71 is 5 to 60%.

In the red paste for a color filter of the present invention, a quinacridone derivative and / or a diketopyrrolopyrrole derivative are added in an amount of 0.1 to 30% by weight in order to improve dispersibility, pigment sublimation resistance and the like in the pigment. ,
Preferably, 0.3 to 20% by weight, more preferably,
It may contain 0.5 to 10% by weight.

In the present invention, the quinacridone derivative is
A compound represented by the general formula (1), wherein the aromatic ring of quinacridone may have a substituent such as a halogen, a cyano group, an alkyl group or an alkoxy group instead of hydrogen.
The diketopyrrolopyrrole derivative is represented by the general formula (2)
Wherein the aromatic ring of diketopyrrolopyrrole may have a substituent such as a halogen, a cyano group, an alkyl group or an alkoxy group instead of hydrogen. Alkyl group, the number of carbon atoms of the alkoxy group is C ₁ -C _15, preferably C ₁ -C _10, more preferably from C ₁ -C _5.

[0021]

Embedded image (In the formula, n is a number from 1 to 4, X is —SO ₂ — or —CH ₂ —, and Y is —OH or a substituent represented by the general formula (3).)

[0022]

Embedded image (Wherein, m is a number of 1 to 4, X is -S0 ₂ - or -CH ₂ -, Y is a substituent represented by -OH or the general formula (3))

[0023]

Embedded image (Wherein, l is a number from 1 to 5, and R ₁ and R ₂ are each independently a C _{1 to} C ₁₅ , preferably a C _{1 to} C ₁₀ , more preferably a C _{1 to} C ₅ alkyl group. )

Specific examples of the quinacridone derivative in the present invention are shown in general formulas (4) to (8), and specific examples of the diketopyrrolopyrrole derivative are shown in general formulas (9) to (13).

[0025]

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[0026]

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In the red paste for a color filter of the present invention, when a pigment is dispersed together with a polymer dispersant, the pigment is finely dispersed and stabilized, so that the surface roughness and contrast of the colored coating film are improved. There is. When an acrylic resin is used as the polymer as the polymer dispersant, "EFKA46", "EF
KA47 "and" SOLSPERS 28000 "manufactured by Zeneca Co. are preferred. When a polyamic acid is used, a polyamic acid containing 4,4'-diaminobenzanilide as a diamine component is preferred.

The polymer in the red paste for a color filter of the present invention is not particularly limited as long as it is a resin generally used for a color filter, and any polymer can be used. For example, various resins such as an acrylic resin, an alkyd resin, a melamine resin, an epoxy resin, a polyvinyl alcohol, a polyamide, a polyamideimide, a polyimide, and a polyimide precursor can be used.
From the viewpoint of heat resistance, light resistance and solvent resistance of the coating film, use of polyimide is particularly preferable.

The polyimide precursor in the present invention refers to the above-mentioned polyimide precursors. The polyimide precursor is
An imide ring is formed by heat or chemical treatment. As the polyimide precursor, polyamic acid and its esterified product are usually used. The polyamic acid mentioned here is represented by the following general formula (14).

[0030]

Embedded image (Where R ₃ represents a C 2-22 tetravalent organic group, R ₄ represents a C 1-22 divalent organic group, and k represents 1 or 2
Is a polymer having a weight average molecular weight of at least 2,000)

The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine.

In the synthesis of the polyamic acid in the present invention, for example, aliphatic or alicyclic tetracarboxylic dianhydrides can be used. 3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,5-cyclopentanetetracarboxylic dianhydride, 1,2,2 4,5-bicyclohexenetetracarboxylic dianhydride, 1,2,2
4,5-cyclohexanetetracarboxylic dianhydride,
1,3,3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1,3-dione and the like. In addition, when an aromatic compound is used, a polyamic acid that can be converted into a film having good heat resistance can be obtained, and specific examples thereof include 3,3 ′, 4,4′-benzophenonetetracarboxylic acid. Dianhydride, pyromellitic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4' -Oxydiphthalic anhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,3', 4,4'- Examples thereof include paraterphenyltetracarboxylic dianhydride and 3,3 ′, 4,4′-methterphenyltetracarboxylic dianhydride. When a fluorine-based material is used, a polyamic acid that can be converted into a film having good transparency in a short wavelength region can be obtained. As a specific example, 4,4 ′-(hexafluoroisopropylidene) is used. ) Diphthalic anhydride; The present invention is not limited to these, and one or more tetracarboxylic dianhydrides are used.

In the synthesis of the polyamic acid in the present invention, for example, aliphatic or alicyclic diamines can be used as the diamine, and specific examples thereof include ethylenediamine and 1,3-diamino. Cyclohexane, 1,4-diaminocyclohexane, 4,4′-diamino-3,3′-dimethyldicyclohexylmethane,
4,4'-diamino-3,3'-dimethyldicyclohexyl and the like. When an aromatic compound is used, a polyamic acid that can be converted into a film having good heat resistance can be obtained. Specific examples thereof include 4,4′-diaminodiphenyl ether and 3,4′-diamino. Diphenyl ether, 4,4'-diaminodiphenylmethane,
3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, m-phenylenediamine, p-phenylenediamine, 2,4-diamino Toluene, 2,5-diaminotoluene, 2,6-diaminotoluene, benzidine, 3,3
'-Dimethylbenzidine, 3,3'-dimethoxybenzidine, o-tolidine, 4,4'-diaminoterphenyl, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 4, 4'-bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
Bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone and the like can be mentioned. When a fluorine-based material is used, a polyamic acid that can be converted into a film having good transparency in a short wavelength region can be obtained. As a specific example, 2,2-bis [4- (4 -Aminophenoxy)
Phenyl] hexafluoropropane and the like.

When siloxane diamine is used as a part of the diamine, the adhesion to the inorganic substrate can be improved. The siloxane diamine is usually used in an amount of 1 to 20 mol% of the total diamine. If the amount of siloxane diamine is too small, the effect of improving the adhesiveness will not be exhibited, and if it is too large, the heat resistance will decrease. Specific examples of the siloxane diamine include bis-3- (aminopropyl) tetramethylsiloxane. The present invention is not limited to this, and one or more diamines are used.

The synthesis of a polyamic acid is generally carried out by mixing and reacting a tetracarboxylic dianhydride and a diamine in a polar organic solvent. At this time, the degree of polymerization of the resulting polyamic acid can be adjusted by the mixing ratio of the diamine and the tetracarboxylic dianhydride.
Usually, N-methyl-2-solvent is used as a solvent for polyamic acid synthesis.
Pyrrolidone, N, N-dimethylacetamide, N, N-
Amide polar solvents such as dimethylformamide,
A lactone-based polar solvent can be used as a mixture.
Examples of the solvent other than lactones include methylcellosolve, ethylcellosolve, methylcarbitol, ethylcarbitol and the like in addition to the amide-based polar solvent. Lactones are aliphatic cyclic esters having 3 to 1 carbon atoms.
2 compound. As specific examples, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ
-Valerolactone, γ-caprolactone, ε-caprolactone, and the like, but are not limited thereto. Particularly, γ-butyrolactone is preferred in view of the solubility of the polyamic acid.

In addition, there are various methods for obtaining a polyamic acid, for example, by reacting a tetracarboxylic acid dichloride with a diamine in a polar organic solvent, and thereafter removing the hydrochloric acid and the solvent to obtain a polyamic acid. However, the present invention is applicable to polyamic acids without depending on the synthesis method.

Next, the number of repeating structural units of the polyamic acid used in the red paste for a color filter of the present invention will be described. Since the mechanical properties of the polyimide film are better as the molecular weight is larger, it is desired that the molecular weight of the polyamic acid, which is a polyimide precursor, be large. On the other hand, when performing pattern processing on the polyimide precursor film by wet etching, if the molecular weight of the polyamic acid is too large, there is a problem that the time required for development becomes too long. Therefore, the preferred range of the number of repeating structural units is 15 to 1,000, more preferably 18 to 400, and still more preferably 20 to 100. Since the molecular weight of the polyamic acid generally varies, the preferred range of the number of repetitions of the structural unit referred to herein is 50 mol% or more, preferably 70 mol% or more, of the total polyamic acid in this range. Preferably, it means that 90 mol% or more is contained.

In the red paste for a color filter of the present invention, the polyamic acid and the pigment are usually in a weight ratio of 1: 1.
9 to 9: 1, preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: 3. If the amount of the polyamic acid is too small, the adhesion of the colored film to the substrate may not be sufficient, whereas if the amount of the pigment is too small, a problem tends to occur in the degree of coloring. Further, in the paste, from the viewpoint of coating properties, drying properties, etc., the solid concentration of the polyamic acid and the pigment together is 2 to 30%,
Preferably it is used in the range of 3 to 25%, more preferably 5 to 20%.

As the solvent in the red paste for a color filter of the present invention, a solvent that dissolves a polyamic acid can be used. Specific examples include N-methyl-2-pyrrolidone, N, N-dimethylacetamide,
Amide polar solvents such as N, N-dimethylformamide, β-propiolactone, γ-butyrolactone, γ-
Lactones such as valerolactone, δ-valerolactone, γ-caprolactone, and ε-caprolactone are exemplified. Further, together with these solvents, ethylene glycol or propylene glycol derivatives such as methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, propylene glycol monoethyl ether, or propylene glycol monoethyl ether acetate, ethyl acetoacetate, methyl 3-
Aliphatic esters such as methoxypropionate and 3-methyl-3-methoxybutyl acetate, or aliphatic alcohols such as ethanol and 3-methyl-3-methoxybutanol can be added as a secondary solvent. is there.

The red paste for a color filter of the present invention contains a surfactant in the color paste of the present invention for the purpose of improving coatability, drying property of a colored film, or improving dispersibility of a pigment. It can also be added. The amount of the surfactant added is usually 0.001 to 10% by weight of the pigment, preferably 0.01 to 1% by weight. If the amount is too small, there is no effect of improving the coating properties, the drying property of the colored film, or the dispersibility of the pigment. If the amount is too large, on the contrary, the physical properties of the coating film become poor or the pigment aggregates. Specific examples of the surfactant include ammonium lauryl sulfate, anionic surfactant such as polyoxyethylene alkyl ether triethanolamine sulfate, stearylamine acetate, cationic surfactant such as lauryl trimethyl ammonium chloride, lauryl dimethylamine oxide, Amphoteric surfactants such as lauryl carboxymethyl hydroxyethyl imidazolium betaine, nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, sorbitan monostearate, and silicones whose main backbone is polydimethylsiloxane Surfactants and the like. In the present invention, one or more surfactants can be used without being limited to these. The surfactant can be added at any point during or before or after the pigment dispersion step. However, care must be taken since the dispersibility of the pigment may change depending on the time of addition.

The red paste for a color filter of the present invention can be prepared by a method in which a pigment is directly dispersed in a resin solution using a disperser, or a method in which a pigment is dispersed in water or an organic solvent using a disperser. And then mixed with a resin solution. The method for dispersing the pigment is not particularly limited, and various methods such as a ball mill, a sand grinder, a three-roll mill, and a high-speed impact mill can be used.

The color filter of the present invention is characterized by using the red paste for a color filter of the present invention.

The method of applying the red paste for a color filter of the present invention to a substrate includes a method of applying the red paste to a substrate by a spin coater, a bar coater, a blade coater, a roll coater, a die coater, a screen printing method, or the like.
Various methods such as a method of immersing the substrate in the solution and a method of spraying the solution on the substrate can be used. As the substrate, a transparent substrate such as soda glass, non-alkali glass, borosilicate glass, quartz glass, or the like, or a semiconductor substrate such as silicon or gallium-arsenic is usually used, but is not particularly limited thereto. When applying the paste on the substrate, the surface of the substrate may be treated with an adhesion aid such as a silane coupling agent, an aluminum chelating agent, or a titanium chelating agent to improve the adhesion between the colored film and the substrate. And can be done as needed.

The red paste for a color filter of the present invention is used for a light-shielding film of an optical element, a color coating film of an optical fiber, and the like, in addition to a color filter of a liquid crystal display device and an image pickup device. For example, an optical fiber coated with a colored coating using the paste can be used as an optical sensor at high temperatures.

An example of a method for producing a color filter using the red paste for a color filter of the present invention will be described.

After the paste is applied on a transparent substrate by the above-described method, a polyimide precursor colored film is formed by air drying, heat drying, vacuum drying, or the like. In the case of heating and drying, use an oven, hot plate, etc., and
It is preferable to carry out the reaction at 180 ° C. for 1 minute to 3 hours. Next, a pattern is formed on the thus obtained polyimide precursor colored film by ordinary wet etching.
First, a positive photoresist is applied on the polyimide precursor colored film to form a photoresist film. Subsequently, a mask is placed on the photoresist film, and ultraviolet light is irradiated using an exposure device. After the exposure, the photoresist coating and the polyimide precursor colored coating are simultaneously etched with an alkaline developer for a positive photoresist. After the etching, the unnecessary photoresist film is removed.

Thereafter, the polyimide precursor colored film is converted into a polyimide colored film by heat treatment. The heat treatment is usually performed at 150 to 450 ° C., preferably at 18 ° C. in air, in a nitrogen atmosphere, or in vacuum.
It is performed continuously or stepwise at a temperature of 0 to 350 ° C. for 0.5 to 5 hours.

When the above steps are performed for three color pastes such as red, green, and blue and, if necessary, black color paste, a color filter for a liquid crystal display device can be manufactured.

In the liquid crystal display device of the present invention, it is preferable to use the color filter of the present invention. In the liquid crystal display device of the present invention, a combination of the color filter and the backlight enables a wide color reproduction range and a bright display.

<Measurement Method> The method for measuring the characteristics of the present invention is as follows.

Transmittance, color coordinates, luminous transmittance: Measured with an MCPD-2000 microspectrophotometer manufactured by Otsuka Electronics Co., Ltd.

Surface roughness (Ra), film thickness: Tokyo Seimitsu Co., Ltd.
Manufactured by Surfcom 1500A.

Contrast: 2 measured by a color luminance meter (“Topcon” BM-5A) on a backlight (Lighting System)
The brightness of the parallel Nicols and the brightness of the orthogonal Nicols of the sample were measured in a degree field of view, and the ratio between the brightness of the parallel Nicols and the brightness of the orthogonal Nicols was defined as the contrast.

[0054]

EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

Examples 1 to 7 A. Synthesis of polyamic acid 95.1 g of 4,4'-diaminodiphenyl ether and 6.2 g of bis (3-aminopropyl) tetramethyldisiloxane were charged together with 525 g of γ-butyrolactone and 220 g of N-methyl-2-pyrrolidone, and 3,3 ′ 4,
4'-biphenyltetracarboxylic dianhydride 144.
After 1 g was added and reacted at 70 ° C. for 3 hours, 3.0 g of phthalic anhydride was added and further reacted at 70 ° C. for 2 hours to obtain a 25% by weight polyamic acid solution (PAA-1).

B. Synthesis of polymer dispersant 4,4′-diaminobenzanilide 161.3 g, 3,
176.7 g of 3'-diaminodiphenyl sulfone and 18.6 g of bis (3-aminopropyl) tetramethyldisiloxane were converted into 2667 g of γ-butyrolactone, N-
Charged with 527 g of methyl-2-pyrrolidone, 3,
3 ', 4,4'-biphenyltetracarboxylic dianhydride
After adding 439.1 g and reacting at 70 ° C. for 3 hours,
2.2 g of phthalic anhydride was added, and the mixture was further reacted at 70 ° C. for 2 hours. A 20% by weight polyamic acid solution (PD-
1) was obtained.

C. Preparation of Dispersion 1.8 g of Pigment Red PR-254 (40 wt.
%), 2.7 g of Pigment Orange PO-38 (60
wt%), 22.5 g of a polymer dispersant (PD-1) and 42.8 g of γ-butyrolactone, 3-methoxy-
20.2 g of 3-methyl-1-butanol was charged together with 90 g of glass beads, and 7 g of the mixture was prepared using a homogenizer.
After dispersion at 000 rpm for 5 hours, the glass beads were filtered,
Removed. Thus, the pigments PR-254 and PO-3
Thus, a 5% dispersion (ROD-1) of the dispersion No. 8 was obtained. Similarly, 5% dispersions (ROD-2 to ROD-4) of the dispersions composed of the pigments PR-254 and PO-38 at the ratios shown in Table 1 were obtained. Further, Pigment Orange PO-38 was replaced with Pigment Orange PO-71 to obtain a 5% dispersion (ROD-5 to ROD-7) of a dispersion liquid composed of the pigments PR-254 and PO-71 at the ratios shown in Table 1. . Where ROD-1
-ROD-7 indicates the number of the dispersion used in Examples 1 to 7.

D. Preparation of Color Paste A solution obtained by diluting 8.0 g of the polymer solution (PAA-1) with 42.0 g of γ-butyrolactone in 50.0 g of the dispersion liquid (ROD-1 to ROD-7) is added and mixed. 1 to ROP-7). Where RO
P-1 to ROP-7 indicate the numbers of the color pastes used in Examples 1 to 7.

E. Preparation and Evaluation of Colored Coating Film Color paste (ROP-1 to ROP-1) on a glass substrate using a spinner such that the finished chromaticity x becomes 0.600.
-7), dried at 120 ° C. for 20 minutes, and a positive photoresist (OFPR-80 manufactured by Tokyo Ohka Co., Ltd.) was placed thereon.
0) was applied and dried at 90 ° C. for 10 minutes. Using an ultraviolet exposure apparatus PLA-501F manufactured by Canon Inc., through a chrome photomask, 60 mJ / cm ² (365 nm)
UV intensity). After the exposure, the film was immersed in a developing solution composed of a 2.25% aqueous solution of tetramethylammonium hydroxide, and the development of the photoresist and the edging of the polyimide precursor colored coating film were simultaneously performed. The unnecessary photoresist layer after the etching was removed with acetone. Further, the colored coating film of the polyimide precursor was heat-treated at 240 ° C. for 30 minutes to convert to polyimide. Table 1 shows the chromaticity of the colored coating film thus obtained. Example 3
Is shown in FIG.

[0060]

[Table 1]

Comparative Examples 1-3 Pigment Red PR-177 4.3 g (80 wt.
%) And 1.1 g of Pigment Yellow PY-83 (20
wt%) and 63.5 g of γ-butyrolactone, 3-
21.1 g of methoxy-3-methyl-1-butanol was charged together with 90 g of glass beads, and dispersed using a homogenizer at 7000 rpm for 5 hours. Then, the glass beads were filtered and removed. The pigment PR-177 is thus obtained.
And a 6% dispersion (RYD-1) of PY-83. Similarly, pigments PR-177 and P at the ratios shown in Table 2
A 6% dispersion of Y-83 (RYD-2 to RYD
-3) was obtained. Here, RYD-1 to RYD-3 indicate the numbers of the dispersions used in Comparative Examples 1 to 3.

Dispersions (RYD-1 to RYD-3) 6
A solution obtained by diluting 25.0 g of the polymer solution (PAA-1) with 22.5 g of γ-butyrolactone to 0.0 g was added and mixed to obtain color pastes (ROP-1 to ROP-7). Here, RYP-1 to RYP-3 indicate the numbers of the color pastes used in Comparative Examples 1 to 3.

A colored coating film was prepared in the same manner as in Examples 1 to 7. Table 2 shows the chromaticity of the colored coating film.

[0064]

[Table 2]

From the comparison between Examples 1 to 7 and Comparative Examples 1 to 3,
It can be seen that Y is greater in the example than in the comparative example at the same chromaticity (x, y). That is, the present invention has higher luminous transmittance with the same color purity than the conventional technology.

FIG. 1 shows the transmission spectrum of Comparative Example 2. As is clear from FIG. 1, the transmission spectrum of Example 3 was 610 nm compared with the transmission spectrum of Comparative Example 2.
It can be seen that not only the bright line of the backlight but also the 580 nm bright line is well transmitted, and the transmission of other bright lines is well suppressed.

Examples 8 to 9 Synthesis of Quinacridone Derivative 1 g of quinacridone per 100 g of chlorosulfonic acid
The mixture was added at 0 to 20 ° C and stirred for 3 hours. The reaction solution was added to ice water 10
In addition to 00g, the mixture was filtered, washed with water and dried to obtain a quinacridone derivative (D-1) represented by the general formula (4).

[0068]

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G. Synthesis of diketopyrrolopyrrole derivative Diketopyrrolopyrrole 1 in 100 g of chlorosulfonic acid
0 g at 10 to 20 ° C. and stirred for 2 hours.
The temperature was raised to 50 ° C., 10 g of thionyl chloride was added, and the mixture was stirred at the same temperature for 3 hours. The reaction solution was added to 1000 g of ice water,
After filtration and washing with water, a water cake of dichlorosulfonated diketopyrrolopyrrole was quantitatively obtained. The dichlorosulfonated water cake is added to 300 g of ice water to form a slurry, 30 g of N, N-dimethylaminopropylamine is added, the mixture is stirred at 10 ° C. or lower for 3 hours, and then the temperature is raised to 40 to 40 ° C.
The mixture was stirred at 50 ° C. for 1 hour, filtered and washed with water. This water cake was added to 300 g of a 0.5% aqueous sodium carbonate solution, stirred for 1 hour, filtered, washed with water, and dried to obtain a diketopyrrolopyrrole derivative (D-2) represented by the general formula (12).

[0070]

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H. Preparation of Dispersion Pigment Red PR-254 2.7g (50wt
%), 2.7 g of Pigment Orange PO-38 (50
wt%), 0.2 g of a quinacridone derivative (D-1), 22.5 g of a polymer dispersant (PD-1), 42.8 g of γ-butyrolactone, and 20.2 g of 3-methoxy-3-methyl-1-butanol. Charged together with 90 g of beads, using a homogenizer, 7000 rpm
After the dispersion for 5 hours, the glass beads were filtered and removed. Thus, a 5% solution (ROD-8) of a dispersion composed of the pigments PR-254 and PO-38 was obtained. Similarly, 2.7 g (50 wt%) of Pigment Red PR-254, 2.7 g (50 wt%) of Pigment Orange PO-38,
0.2 g of quinacridone derivative (D-1), 0.2 g of diketopyrrolopyrrole derivative (D-2), 22.5 g of polymer dispersant (PD-1) and γ-butyrolactone
42.8 g, 3-methoxy-3-methyl-1-butanol 20.2 g were charged together with 90 g of glass beads,
After dispersing for 5 hours at 7000 rpm using a homogenizer, the glass beads were filtered and removed. Thus, a 5% solution of the dispersion (ROD-9) was obtained. Here ROD-
8 to ROD-9 indicate the numbers of the dispersions used in Examples 8 to 9.

I. Preparation of Color Paste A solution obtained by diluting 8.0 g of the polymer solution (PAA-1) with 42.0 g of γ-butyrolactone in 50.0 g of a dispersion liquid (ROD-8 to ROD-9) is added and mixed. 8 to ROP-9) were obtained. Where RO
P-8 to ROP-9 indicate the numbers of the color pastes used in Examples 8 to 9.

J. Preparation and evaluation of colored coating film Color paste (RP-1, 8, 9) with a spinner such that the finished chromaticity x is 0.600 on a glass substrate.
Was applied and dried at 120 ° C. for 20 minutes. A positive photoresist (OFPR-800 manufactured by Tokyo Ohka Co., Ltd.) was applied thereon and dried at 90 ° C. for 10 minutes. Using a UV exposure machine PLA-501F manufactured by Canon Inc., exposure was performed through a chrome photomask at 60 mJ / cm ² (ultraviolet intensity of 365 nm). After the exposure, the film was immersed in a developing solution composed of a 2.25% aqueous solution of tetramethylammonium hydroxide, and the development of the photoresist and the edging of the polyimide precursor colored coating film were simultaneously performed. The unnecessary photoresist layer after the etching was removed with acetone. In order to examine the heat resistance of the red pigment, the colored coating film of the polyimide precursor was heat-treated at 240 ° C. for 30 minutes, and then heat-treated at 280 ° C. for 30 minutes to strengthen and convert to polyimide. Table 3 shows the surface roughness and contrast of the colored coating film thus obtained.

[0074]

[Table 3]

By adding the quinacridone derivative and / or the diketopyrrolopyrrole derivative, a better coating film without pigment sublimation can be obtained. Further, by adding a quinacridone derivative and / or a diketopyrrolopyrrole derivative, fine dispersion and stabilization of the pigment are achieved, and the surface roughness and the contrast are improved.

[0076]

Since the present invention is constructed as described above, it is possible to obtain a red paste for a color filter capable of providing a red filter which achieves both high transmission and high color purity by effectively utilizing the bright line of the backlight.

[Brief description of the drawings]

FIG. 1 shows Pigment Red PR-2 obtained in Example 3.
And the transmission spectrum of the red coloring film composed of Pigment Red PR-177 and Pigment Yellow PY-83 obtained in Comparative Example 2 and the emission spectrum of the backlight. Show.

Claims (13)

[Claims] 1. A red paste for a color filter, comprising a pigment, a polymer and a solvent as main components, wherein the pigment contains 2 to 98% by weight of Pigment Red PR-254. . 2. A pigment containing a quinacridone derivative and / or a diketopyrrolopyrrole derivative in an amount of 0.1 to 30% by weight.
The red paste for a color filter according to claim 1, further comprising: 3. Pigment Red PR-2 as the pigment.
The red paste for a color filter according to any one of claims 1 to 2, comprising 54 and an orange pigment. 4. The red paste for a color filter according to claim 3, wherein naphthol orange and / or diketopyrrolopyrrole orange are used as said orange pigment. 5. The pigment according to claim 5, wherein said orange pigment is Pigment Orange P.
O-38 and / or Pigment Orange PO-71
4. The red paste for a color filter according to claim 3, wherein 6. Pigment red PR-254 in all pigments
Is 5 to 95%, and the weight ratio of orange pigment is 5 to 9%.
The red paste for a color filter according to any one of claims 3 to 5, wherein the content is 5%. 7. Pigment red PR-254 in all pigments
Weight ratio of 5-70%, Pigment Orange PO-3
The red paste for a color filter according to any one of claims 3 to 5, wherein the weight ratio of 8 is 30 to 95%. 8. Pigment Red PR-254 in all pigments
Is 40-95% by weight, Pigment Orange PO-
The red paste for a color filter according to any one of claims 3 to 5, wherein the weight ratio of 71 is 5 to 60%. 9. A red paste for a color filter according to claim 1, wherein said polymer is a resin having a carboxyl group. 10. The red paste for a color filter according to claim 9, wherein the polymer is a polyamic acid. (11) As a dispersant, 4,4 ′ is added to a diamine component.
The red paste for a color filter according to any one of claims 1 to 10, wherein a polyamic acid containing diaminobenzanilide is used. 12. A color filter using the red paste for a color filter according to any one of claims 1 to 11. 13. A liquid crystal display device using the color filter according to claim 12.