JP2002121457A - Pigment dispersion, colorant composition and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a fine pigment dispersion and a colorant composition having excellent flow characteristics and dispersion stability and to thereby provide a color filter having excellent surface roughness and contrast of a pixel film. SOLUTION: This pigment dispersion is characterized as comprising a pigment dispersing agent represented by the general formula (1): Q-(X-Y-Z)n [wherein, Q denotes a quinophthalone residue; n denotes an integer of 1-4; X is selected from amide bond, ether bond, sulfide bond, sulfoxide bond and sulfone bond; Y is selected from an aryl group and a heteroaromatic group; and Z is selected from carboxy group, ester group, hydroxy group, mercapto group, amino group, sulfonic acid group and groups represented by the general formula (2): (CH2)m-NR1R2 (wherein, R1 and R2 may be each the same or different and are each selected from hydrogen, an alkyl group and an aryl group; and m denotes an integer of 1-6). The colorant composition is characterized as comprising the pigment dispersing agent in the colorant composition consisting essentially of a pigment, a resin and a solvent. The color filter is characterized in that colored layers are colored films formed from each colorant composition in the color filter having pixels comprising the colored layers provided in an optional number of colors in a desired pattern form for each color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a pigment dispersion, a colorant composition, and a color filter.

[0002]

2. Description of the Related Art In order to color a liquid crystal display, R (red), G (green), B
A color filter in which pixels of three colors (blue) are arranged in a line shape or a mosaic shape is used. For example, a TFT (thin film transistor) color liquid crystal display, which is currently widely used, is a panel in which liquid crystal is sealed between a transparent glass substrate on which a color filter is formed, a transparent glass substrate on which a TFT is formed, and a backlight. Composed of light sources. When light emitted from the backlight passes through the liquid crystal panel, an image is displayed by controlling the transmittance of the light by the voltage applied to the liquid crystal. Since each pixel needs to be similar to the chromaticity characteristics of the CRT phosphor, the pigments are selected to match the light transmission characteristics of the backlight and the liquid crystal display element, and two or more pigments are toned at a fixed ratio. Often used. For example, the R (red) pixel of the color filter is red, orange,
Two or more types of yellow pigments are selected and used at a fixed ratio. Similarly, the G (green) pixel is also used by selecting two or more kinds of green, orange, and yellow pigments and toning them. The pigment is selected from the required chromaticity characteristics as described above, but if the combination of the pigments or the toning ratio is changed, a problem of dispersion stabilization occurs. Research is also being conducted by pigment manufacturers to disperse the pigment into fine and stable particles.
In addition to general rosin treatment, surface treatments such as acid group treatment, basic treatment, and pigment derivative treatment are described in, for example,
No. 28162, JP-A-59-168070, and the like. Also, a method of using a pigment derivative as a dispersing aid has been proposed, for example, in Japanese Patent Publication No. 4-3841. However, even with these methods, the selected pigment cannot always be dispersed into fine and stable particles. Generally, red, orange, and yellow pigments are difficult to disperse, and when two or more pigments are prepared, or when the content of the yellow pigment is large, there is a problem in dispersion stability. If the dispersion of the pigment is unstable, the pigment will agglomerate, reducing the surface roughness and contrast of the pixel coating,
The display failure of the liquid crystal display occurs.

[0003]

SUMMARY OF THE INVENTION In view of the background of the prior art, the present invention provides a pigment dispersion and a colorant composition which are fine and have excellent flow characteristics and dispersion stability. It is intended to provide a color filter having excellent surface roughness and contrast.

[0004]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the pigment dispersion of the present invention contains a pigment dispersant represented by the following general formula (1).

[0005]

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[0006]

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Further, the colorant composition of the present invention comprises a pigment,
A colorant composition comprising a resin and a solvent as main components, wherein the pigment dispersant is contained.

The color filter of the present invention is a color filter having pixels of a color layer provided in a desired pattern for each color in an arbitrary number of colors, wherein the color layer is formed of the colorant composition. It is characterized by being a colored film to be formed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has been made to thoroughly study the above-mentioned problems, that is, a pigment dispersion and a colorant composition which are fine and have excellent flow characteristics and dispersion stability, and use a specific pigment dispersant. It has been surprisingly found that such a problem can be solved all at once and that an excellent color filter can be provided.

The pigment dispersion of the present invention has the following general formula (1)
Characterized by containing a pigment dispersant represented by the formula:

[0011]

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[0012]

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Among these, an aryl group includes, for example, a phenyl group, a naphthyl group, a biphenyl group, an anthranyl group,
It represents an aromatic hydrocarbon group such as a phenanthryl group, a terphenyl group and a pyrenyl group, which may be unsubstituted or substituted. The heteroaromatic group includes, for example, pyridine, pyrazine, triazine, quinoline, thiophene,
Furan, pyrrole, oxazole, oxadiazole,
It represents an aromatic group containing a heterocyclic ring such as imidazole, triazole, thiazole, thiadiazole, phthalic anhydride, phthalimide, naphthalimide, etc., which may be unsubstituted or substituted. Further, the ester group and the amino group include those substituted with an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, a heterocyclic ring, or the like. Further, the alkyl group is, for example, a methyl group, an ethyl group, a propyl group,
It represents a saturated aliphatic hydrocarbon group such as a butyl group, which may be unsubstituted or substituted. X is particularly preferably an amide bond. As Z, a carboxyl group is particularly preferably used.

The pigment dispersant is not particularly limited, but specifically, those having the following structures are preferably used.

[0015]

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[0016]

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[0017]

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The pigment dispersion of the present invention is prepared by using a disperser.
It is manufactured by dispersing a pigment in water or an organic solvent. Such organic solvents are not particularly limited,
For example, (poly) alkylene glycol ether-based polar solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, N-methyl-2-pyrrolidone, N, N- Amide polar solvents such as dimethylacetamide and N, N-dimethylformamide, β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-
Lactones such as caprolactone and ε-caprolactone can be used.

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 are employed. In the above pigment dispersion, the solvent and the pigment are preferably in a weight ratio of 10:90 to 90:10, more preferably 3:10.
It is preferable to use a mixture in the range of 0:70 to 80:20.

To produce a color filter, usually,
A colorant composition in which a pigment is dispersed in a solution in which a resin is dissolved in water or an organic solvent is used.

As the pigment used in the pigment dispersion and the colorant composition of the present invention, those having high transparency and excellent light resistance, heat resistance and chemical resistance are preferable. When a specific example of a typical pigment is shown by a color index (CI) number, the following are preferably used, but none of them is limited thereto.

Examples of yellow pigments include pigment yellow (hereinafter abbreviated as PY) 12, 13, 17, 20, 24,
83, 86, 93, 95, 109, 110, 117, 1
25, 129, 137, 138, 139, 147, 14
8, 150, 153, 154, 166, 168, 185
Are used.

Examples of orange pigments include Pigment Orange (hereinafter abbreviated as PO) 13, 36, 38,
43, 51, 55, 59, 61, 64, 65, 71 and the like are used.

Examples of red pigments include Pigment Red (hereinafter abbreviated as PR) 9, 48, 97, 122, 1
23, 144, 149, 166, 168, 177, 17
9,180,192,209,215,216,21
7, 220, 223, 224, 226, 227, 22
8, 240, 254, etc. are used.

Examples of purple pigments include Pigment Violet (hereinafter abbreviated as PV) 19, 23, 29, 3
0, 32, 37, 40, 50, etc. are used.

Examples of blue pigments include Pigmentable (hereinafter abbreviated as PB) 15, 15: 3, 15: 4,
15: 6, 22, 60, 64, etc. are used.

Examples of green pigments include pigment greens (hereinafter abbreviated as PG) 7, 10, 36, and the like. Examples of black pigments include pigment black 7, titanium black, and the like. used.

These pigments may be subjected to a surface treatment such as a rosin treatment, an acid group treatment and a basic treatment as required.

The above-mentioned pigment is a color filter in which R (red), G (green), and B (blue) three-color pixels are
Tones are used by combining several colors to match the chromaticity characteristics of the RT phosphor and the liquid crystal characteristics of the backlight and LCD.

Taking the case of R (red) as an example, PR
-177 and a combination of PY-138, PR-254,
The chromaticity is adjusted by the combination of PY-138 and the combination of PR-209 and PO-38.

In the case of G (green), PG-7 or PG
-36 and the above-mentioned yellow pigments, for example, PY-17, PY-8
The chromaticity is adjusted by the combination of No. 3, the combination of PY-138, the combination of PY-139, the combination of PY-150, and the like.

The resin used in the colorant composition of the present invention is not particularly limited as long as it is a resin generally used for a color filter, and any resin can be used. For example, various resins such as an acrylic resin, an alkyd resin, a melamine resin, polyvinyl alcohol, polyamide, polyamide imide, polyimide, and a polyimide precursor can be used. Among resins soluble in an alkaline aqueous solution, a photosensitive acrylic resin having a carboxyl group and a polyimide precursor are particularly preferable because a pattern can be easily formed by development or etching. As the polyimide precursor, polyamic acid and its esterified product are usually used, and form an imide ring by heat or chemical treatment.

The solvent used in the colorant composition of the present invention is not particularly limited, and water and an organic solvent can be used. The organic solvent is not particularly limited. For example, the (poly) alkylene glycol ether-based polar solvent, the amide-based polar solvent, the lactones, and the like can be used. When polyimide is used as a component of the pixel matrix, the solvent used in the colorant composition is preferably a solvent that dissolves the polyimide precursor.

As the solvent for dissolving the polyimide precursor, polar organic solvents such as the amide-based polar solvents and the lactones are preferably used. In addition, usually, the polyimide precursor alone is not dissolved, ethanol, butanol, alcohols such as isopropanol, methyl cellosolve, cellosolves such as ethyl cellosolve, organic solvents such as propylene glycol derivatives such as propylene glycol monomethyl ether, a polyimide, It can be used by mixing with a solvent that dissolves the precursor.

Such a colorant composition is produced by a method in which a pigment is directly dispersed in a resin solution using a disperser, a method in which the pigment dispersion is mixed with the resin solution, or the like.
The method for dispersing the pigment is not particularly limited, and the various methods described above are employed.

In the above colorant composition, the weight ratio of the resin component and the pigment is preferably 20:80 to 90:10, more preferably 30:70 to 80:20, and particularly preferably 40:60 to 70:30. It is used by mixing in the range. If the amount of the resin component is too small, the adhesion of the colored coating to the substrate becomes poor, and if the amount of the pigment is too small, the degree of coloring becomes a problem. The ratio of the solvent in the colorant composition is preferably in the range of 10 to 99.5 wt%, more preferably 50 to 98 wt%.

The pigment dispersant of the present invention can be used alone, but can also be used as a mixture of two or more kinds. Further, the pigment dispersant can be used by mixing with a generally known pigment dispersant. Good. Examples of commonly known pigment dispersants include, but are not particularly limited to, for example, decanamide, dodecaneamide, N-dodecylhexadecamide, N-octadecylpropioamide, N, N-dimethyldodecaneamide, N Amide compounds such as N, N-dihexylacetamide, diethylamine, triethylamine,
Amine compounds such as diheptylamine, dibutylhexadecylamine and aniline; amine compounds having a hydroxyl group such as monoethanolamine, diethanolamine and triethanolamine; acrylic resins having a carboxyl group; and polymers having a polar group such as polyamic acid. Can be used.

The amount of the pigment dispersant added to the pigment dispersion and the colorant composition is preferably 0.1 to 200 wt%, more preferably 1 to 50 wt%, based on the pigment.
% Is good.

From the viewpoint of dispersion stability of the pigment dispersion and the colorant composition, it is preferable to remove ionic impurities from the pigment dispersion and the colorant composition. The method for removing the ionic impurities is not particularly limited, but includes use of an ion exchange resin. For example, by directly connecting a mill-type disperser filled with ceramic beads and a column filled with granular ion-exchange resin, ionic impurities can be removed simultaneously with the dispersion of the pigment.

A surfactant is added to the colorant composition of the present invention for the purpose of improving the coating property of the colorant composition and the uniformity of the surface of the colored film, or for improving the dispersibility of the pigment. Can be added. The amount of the surfactant added is preferably 0.001 to 10 wt.
%, More preferably 0.01 to 1 wt%. If the addition amount is too small, there is no effect of improving applicability, uniformity of the colored film surface, or dispersibility of the pigment,
On the other hand, if the amount is too large, the coatability becomes poor and the pigment aggregates.

Specific examples of such a surfactant include anionic surfactants such as ammonium lauryl sulfate and polyoxyethylene alkyl ether triethanolamine sulfate; cationic surfactants such as stearylamine acetate and lauryltrimethylammonium chloride;
Amphoteric surfactants such as lauryl dimethylamine oxide and lauryl carboxymethyl hydroxyethyl imidazolium betaine, and nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and sorbitan monostearate are preferably used. Such surfactants may be one or two
A mixture of more than one species can be used. Such a surfactant can be added at any time during or before or after the pigment dispersion step. However, care must be taken because the dispersibility of the pigment may change depending on the time of addition.

As a method of applying the colorant composition on the substrate, a method of applying the colorant composition to the substrate by a spin coater, a bar coater, a blade coater, a roll coater, a die coater, a screen printing method, etc. Various methods can be used, such as a method of immersing in a substrate and a method of spraying a colorant composition onto a substrate. As such a substrate, a transparent substrate such as soda glass, non-alkali glass, borosilicate glass, and quartz glass, and a semiconductor substrate such as silicon and gallium-arsenic are usually used, but are not particularly limited thereto. When the colorant composition is applied on such a substrate, treating the substrate surface with an adhesion aid such as a silane coupling agent can improve the adhesion between the colored film and the substrate.

The colored film formed by using the colorant composition of the present invention is used for a color filter of a liquid crystal display and an image pickup device, a light shielding film of an optical device, a coating film of an optical fiber, and the like.

For example, an optical fiber coated with a coloring film using a coloring agent composition can be used as an optical sensor at a high temperature. The thickness of the colored film is not particularly limited, but is preferably 0.1 to 10 μm,
More preferably, it is 0.5 to 5 μm. If the film thickness is too small, light absorption will be too small, and the optical characteristics as a color filter will not be satisfied. If the film thickness is too large, on the contrary, problems such as excessive absorption of light may occur, and the optical characteristics as a color filter may not be satisfied. The optical properties usually have a desired chromaticity depending on the application, so that the pigment composition and the film thickness are adjusted to match the chromaticity to produce a colored film.

When used as a color filter for a liquid crystal display device, important characteristics of the colored film include contrast and surface roughness in addition to chromaticity. The contrast is preferably 800 or more, more preferably 1 in the state of a colored film.
It is desired that the number be 000 or more, more preferably 1200 or more. If the contrast is less than 800, the contrast of the display becomes too low, and the display characteristics may be deteriorated. The surface roughness is usually represented by a center line surface roughness (Ra), and is preferably 0.008 μm or less, more preferably 0.006 μm or less, and further preferably 0.004 μm or less. If the surface roughness (Ra) is larger than 0.008 μm, the orientation of the liquid crystal may be disturbed when a display is formed, and display characteristics may be poor.

Next, taking a color filter for a liquid crystal display, which is a typical application of a color filter, as an example, the production of a color filter using polyimide as a resin component of a pixel matrix and polyamic acid as a precursor thereof. An example of the method will be described.

After the colorant composition is applied on a transparent substrate by the method described above, 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
In the range of 180 ° C, more preferably 80-120 ° C.
Perform for 2 to 3 hours. If the temperature is too low, the solvent does not readily evaporate. Conversely, if the temperature is too high, the solubility in the developer decreases.

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 apparatus. After the exposure, the photoresist coating and the polyimide precursor colored film are simultaneously etched with a positive photoresist alkaline developer. After the etching, the unnecessary photoresist film is removed.

Thereafter, the polyimide precursor colored film is converted into a polyimide colored film by performing a heat treatment. The heat treatment is preferably performed at 150 to 450 ° C., more preferably 180 to 350 ° C., and particularly preferably 200 to 32 ° C. in air, in a nitrogen atmosphere, or in vacuum.
It is carried out continuously or stepwise at a temperature of 0 ° C., preferably for 0.5 to 5 hours. When the above steps are performed on the three colorant compositions of R (red), G (green), and B (blue) and, if necessary, the black colorant composition, a color filter for a liquid crystal display is produced. Can be.

[0050]

EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The measuring methods described in the examples are as shown below. (Measurement method) <Contrast> The brightness of parallel Nicols and the brightness of parallel Nicols of a sample are measured with a color luminance meter (Topcon BM-5A) on a back light (Toppan BM-5A) in a field of view twice. The ratio between the luminance of the direct Nicol and the contrast was defined as the contrast.

<Surface Roughness> The center line average roughness (Ra) was measured using Surfcom 1500A manufactured by Tokyo Seimitsu Co., Ltd.

<Chromaticity> MCPD-2 manufactured by Otsuka Electronics Co., Ltd.
It was measured with a C light source at 000 twice in a visual field.

<Viscosity and Yield Value> Measured with a viscometer, model RE100L, manufactured by Toki Sangyo Co., Ltd. (Production Example 1: Synthesis of pigment dispersant) PY-138 400
g, 400 g of potassium hydroxide and 3600 g of water were reacted at 90 ° C. for 8 hours, and then cooled to room temperature.
% Hydrochloric acid (540 ml) was added dropwise. After filtration, washing with water and vacuum drying, a pigment dispersant (D-1) represented by the following formula was obtained.

[0054]

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(Production Example 2: Synthesis of pigment dispersant) N, N-
7.15 g of dimethylpropanediamine, 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride 2
5.08 g, 220 g of γ-butyrolactone were charged,
After reacting at 60 ° C for 1 hour, quinaldine 10.3g
Was added and reacted at 180 ° C. for 5 hours. After cooling to room temperature, the reaction mixture was poured into 1000 g of methanol, filtered, washed with water, and then washed with 100 ml of methanol. Vacuum drying was performed to obtain a pigment dispersant (D-2) represented by the following formula.

[0056]

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(Production Example 3: Synthesis of pigment dispersant) N, N-
7.15 g of dimethylpropanediamine, 21.72 g of 4,4′-oxydiphthalic dianhydride and 220 g of γ-butyrolactone were charged and reacted at 60 ° C. for 1 hour, and 10.3 g of quinaldine was added. Allowed to react for hours. After cooling to room temperature, the reaction mixture was poured into 1000 g of methanol, filtered, washed with water, and then washed with 100 ml of methanol.
Washed with ml. Vacuum drying was performed to obtain a pigment dispersant (D-3) represented by the following formula.

[0058]

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Reference Example 1 Synthesis of Polyamic Acid
'-Diaminodiphenyl ether 150 g, 3, 3'
49.6 g of diaminodiphenylsulfone and bis (3-aminopropyl) tetramethyldisiloxane
12.4 g was charged together with 2730 g of γ-butyrolactone, 161 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and pyromellitic dianhydride 10
After adding 6.8 g and reacting at 60 ° C. for 5 hours, adding 1.96 g of maleic anhydride and further reacting at 60 ° C. for 1 hour, a 15% polyamic acid solution having a viscosity of 15 poise (25 ° C.) ( PA-1) was obtained. Reference Example 2: Synthesis of polyamic acid 114.14 g of 4,4'-diaminodiphenyl ether and bis (3-
Aminopropyl) tetramethyldisiloxane 7.46
g, 1298 g of γ-butyrolactone, N-methyl-2-
Prepared with 267 g of pyrrolidone, 3, 3 ', 4, 4
After adding 173 g of '-biphenyltetracarboxylic dianhydride and reacting at 70 ° C for 3 hours, adding 3.55 g of maleic anhydride and further reacting at 70 ° C for 1 hour, the viscosity was 100 poise (25 ° C). Was obtained as a 16% polyamic acid solution (PA-2). Reference Example 3 Synthesis of Polyamic Acid 330.6 g of 4,4 ′-(9-fluoronylidene) dianiline and bis (3-aminopropyl) tetramethyldisiloxane 1
2.4 g was charged together with 2606 g of γ-butyrolactone, and 4,6.9′-oxydiphthalic dianhydride 306.9
g, and reacted at 70 ° C. for 3 hours. Then, 1.95 g of maleic anhydride was added, and the mixture was further reacted at 70 ° C. for 2 hours. (25 ° C.) of a 15% polyamic acid solution (PA-3) was obtained. Example 1 59.06 g of PG-36, 17.58 of PY-138
g, PY-150 16.54 g, pigment dispersant (D-
1) 1.32 g, polyamic acid (PA-1) 70
g, γ-butyrolactone 1335.5 g was charged into a mill type disperser filled with zirconia beads, and 3200 r
Dispersed at pm for 3 hours. In this way, the solid content concentration 7
% Pigment dispersion was obtained. To 21.33 g of this dispersion, 7.71 g of polyamic acid (PA-2) and 0.49 g of polyamic acid (PA-3) were added with 3.8 of γ-butyrolactone.
6 g, 3-methoxy-3-methyl-1-butanol
5.21 g, 0.2% surfactant BYK361 (BYK361)
-Chemie) added γ-butyrolactone 1.4
The solution diluted with 0 g was added and mixed to obtain a colorant composition. The viscosity of this colorant composition was 19 centipoise (1
(0 rpm, 25 ° C.), the yield value was 0.001 Pa, and the flow characteristics were very excellent. This colorant composition was applied onto a glass substrate so that the finished chromaticity y was 0.56, dried at 120 ° C. for 20 minutes, and heat-treated at 270 ° C. for 40 minutes to convert to polyimide. The G (green) coating film thus obtained has a surface roughness of 0.002 μm.
m, and excellent characteristics of contrast 1800. Example 2 Instead of pigment dispersant (D-1), pigment dispersant (D-2)
A colorant composition was prepared in the same manner as in Example 1, except that G was used, and a G (green) coating film was prepared. The viscosity of the colorant composition was 20 centipoise (10 rpm, 25 rpm).
° C), the yield value was 0.0015 Pascal and the flow characteristics were very good. The coating has a surface roughness of 0.002 μm,
Excellent characteristics with a contrast of 1700 were exhibited. Example 3 Instead of the pigment dispersant (D-1), the pigment dispersant (D-3) was used.
A colorant composition was prepared in the same manner as in Example 1, except that G was used, and a G (green) coating film was prepared. The viscosity of the colorant composition was 20 centipoise (10 rpm, 25 rpm).
° C), the yield value was 0.0012 Pascal and the flow characteristics were very good. The coating has a surface roughness of 0.002 μm,
Excellent characteristics of contrast 1750 were exhibited. Comparative Example 1 A colorant composition was prepared in the same manner as in Example 1 except that the pigment dispersant (D-1) was not used and the weight of PY-138 was changed to 18.9 g. A film was prepared. The viscosity of the colorant composition was 42 centipoise (10 rpm).
m, 25 ° C.), the yield value was 0.31 Pascal and the flow characteristics were inferior. The coating has a surface roughness of 0.012 μm,
The contrast 700 was low. Example 4 81 g of PR-254, 24.3 g of PY-138, 2.7 g of a pigment dispersant (D-1), and polyamic acid (PA-1)
80 g, γ-butyrolactone 967 g and 3-methoxy-3-methyl-1-butanol 345 g were charged into a mill-type disperser filled with zirconia beads, and 4200
Dispersed for 2 hours at rpm. Thus, the solid content concentration of 8
% Pigment dispersion was obtained. To 52.08 g of this dispersion, 54.86 g of polyamic acid (PA-2) and 4.6 g of polyamic acid (PA-3) were added to 94.3 γ-butyrolactone.
7 g, 3-methoxy-3-methyl-1-butanol 8
2.5 g, 0.2% surfactant BYK361 (BYK-
Chemie) added γ-butyrolactone 10.2
The solution diluted with 3 g was added and mixed to obtain a colorant composition. The viscosity of the colorant composition is 15 centipoise (10 r
pm, 25 ° C.), the yield value was 0.000001 Pa, and the flow characteristics were excellent. This colorant composition was applied on a glass substrate so that the finished chromaticity x became 0.62, dried at 120 ° C. for 20 minutes, and heat-treated at 250 ° C. for 40 minutes to convert to polyimide. The R (red) coating film thus obtained has a surface roughness of 0.002 μm.
m, excellent characteristics of contrast 1300 were exhibited. Example 5 Instead of pigment dispersant (D-1), pigment dispersant (D-2)
A colorant composition was prepared in the same manner as in Example 4 except that R was used, and an R (red) coating film was prepared. The viscosity of this colorant composition is 16 centipoise (10 rpm, 25 ° C.)
The yield value was 0.000002 Pa and the flow characteristics were very excellent. The coating has a surface roughness of 0.002 μm,
Excellent characteristics with a contrast of 1200 were exhibited. Example 6 Instead of the pigment dispersant (D-1), the pigment dispersant (D-3) was used.
A colorant composition was prepared in the same manner as in Example 4 except that R was used, and an R (red) coating film was prepared. The viscosity of the colorant composition is 16 centipoise (10 rpm, 25 ° C.)
The yield value was 0.00002 Pa and the flow characteristics were very good. Further, the coating film showed excellent characteristics of a surface roughness of 0.002 μm and a contrast of 1250. Comparative Example 2 A colorant composition was prepared in the same manner as in Example 4 except that the pigment dispersant (D-1) was not used and the weight of PY-138 was changed to 27.0 g. Was prepared. The viscosity of the colorant composition was 30 centipoise (10 rpm, 25 rpm).
° C), the yield value was 0.02 Pascal and the flow characteristics were inferior. Further, the coating film showed a low surface roughness of 0.009 μm and a low contrast of 650.

[0060]

According to the present invention, it is possible to provide a pigment dispersion liquid and a colorant composition which are fine and have excellent flow characteristics and dispersion stability, and are therefore excellent in surface roughness and contrast of a pixel coating film. And a color filter for a liquid crystal display and an image sensor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 201/00 201/00 G02B 5/20 101 G02B 5/20 101 F term ( REFERENCE) 2H048 BA45 BA47 BA48 BB02 BB42 4D077 AA01 AA06 AB03 AC05 DC04Y DC06Y DC10Y DC19Y DC26Y DC28Y DC39Y DC44Y DC45Y DC48Y DC49Y DC64Y DC71Y DC72Y DD28Y DD42Y DD48Y DE19Y DE28Y DE34Y 4J037 CB 001 001 001 DJ031 DJ051 GA02 GA06 GA08 GA09 GA13 HA156 JA19 JA26 JA27 JA68 JB12 JB28 JC01 JC02 JC12 JC13 KA06 KA08 KA09 KA17 NA01 NA24 NA25 PB08 PC08

Claims (5)

[Claims] 1. A pigment dispersion comprising a pigment dispersant represented by the following general formula (1). Embedded image Embedded image 2. The pigment dispersion according to claim 1, wherein X in the general formula (1) is an amide bond. 3. The pigment dispersion according to claim 1, wherein Z in the general formula (1) is a carboxyl group. 4. A colorant composition comprising a pigment, a resin and a solvent as main components, comprising the pigment dispersant according to claim 1. 5. A color filter having pixels of a color layer provided in a desired pattern for each color in an arbitrary number of colors, wherein the color layer is formed by the colorant composition according to claim 4. A color filter, which is a membrane.