TW201624113A - Red pigment dispersion resist composition for color filter - Google Patents

Abstract

An object of the present invention is to provide a red pigment dispersion resist composition for color filter, which is excellent in dispersion stability, coloring strength, contrast, brightness, heat resistance and solvent resistance and which is a red pigment dispersion resist composition for color filter that comprises C.I. Pigment Red 221, C.I. Pigment Red 177, pigment dispersion aid represented by general formula (1) and/or (2), an alkali-soluble resin, a photo-polymerizable compound, a photo-polymerization initiator, and an organic solvent. In these formulas, X and Y may be the same or different and are phenyl substitutable by F, Cl, Br, NO2, CH3 or OCH3. M represents H, Na, K, NH4 or NR1 R2 R3 R4, wherein R1, R2, R3 and R4 may be the same or different and are saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms that are substitutable by other substituent, or an aromatic hydrocarbon group having 6 to 10 carbon atoms that are substitutable by other substituent.) m is an integer greater than 1.

Description

Color filter dispersion resist composition with red pigment

The present invention relates to a red pigment dispersion resist composition for a color filter used for a color filter used in a color liquid crystal display device, an image pickup element, or the like.

The color filter used in a color liquid crystal display device or the like is configured by arranging two or more kinds of fine bands (strips) of different hue in parallel on the surface of a transparent substrate such as glass, or arranging fine pixels in a vertical and horizontal direction. Configure it. The pixel size is a fine size of several 10 μm to several 100 μm, and each hue is neatly arranged in a predetermined order.

In the color liquid crystal display device, white light from the backlight is transmitted through the color filter as described above to be colored, and a color image is displayed on the screen. Therefore, as a basic property of a color filter, high transparency is required. Therefore, conventionally, it is produced by using a so-called dyeing method in which a dye excellent in color characteristics is dispersed in a molecular state in a resin to perform dyeing. However, in recent years, with the diversification of applications, when it is required to improve the reliability for long-term use such as heat resistance and light resistance, an organic pigment can be used instead of a dye whose reliability is limited. Further, various methods such as a printing method, an inkjet method, and a photolithography method have been proposed for the method of producing a color filter. Further, in recent years, in order to promote the power saving of a liquid crystal display device with a device, a color filter having pixels is required to improve the transmittance of visible light, and a bright display screen can be obtained more efficiently with limited power consumption. It is possible to achieve high contrast with high definition of the overall image.

The above-mentioned visible light transmission and contrast performance largely depend on the performance of the pigment dispersed in each color pixel of the color filter, and it is difficult to achieve the desired performance by using only one type of pigment for the red pixel, thereby proposing a combination of other Toner pigment. For example, a system in which a reddish pigment is used in combination with the pigment red 177 of the main red pigment (for example, refer to Patent Document 1). Here, as the toned red pigment, a red pigment having a maximum absorption peak in a wavelength region of 535 nm to 555 nm, that is, pigment red 5, 9, 10, 17, 48:1, 48:2, 48:3 can be cited. 48:4, 52:2, 119, 166, 216, 224, 226. However, there is a limit to the improvement of the above-mentioned transmittance and contrast performance with respect to the combination system of the above-mentioned red pigment.

Further, a system in which pigment red 177 or 254 is used as the red color pigment in Pigment Red 242 of the main red pigment has been proposed (for example, refer to Patent Document 2). Further, a system in which a red pigment such as Pigment Red 177, 207, 209, 224, and 242 is mixed as a red color pigment in Pigment Red 254 of the main red pigment (see, for example, Patent Document 3 and Patent Document 4) . However, when Pigment Red 242 is used as the main pigment, there is a problem that the color tone is yellowish. On the other hand, when Pigment Red 254 is used, the transmittance is increased, but the film thickness of the colored film is increased while the contrast is lowered. Further, from the properties of the pigment, there is a problem that the solvent resistance is deteriorated or the heat resistance is deteriorated (the sublimate is generated).

Further, in recent years, the color reproduction region of the color filter has been enlarged by using a backlight or the like using an LED as a light source. However, since the wavelength of light irradiated on each is different, available coloring pigments are limited. For example, in the case of a backlight in which an LED is used as a light source, the combination of the pigments as described above has to further increase the pigment concentration of the pixel from the relationship of the absorption wavelength region of light. Therefore, as a red pigment dispersion resist composition, there is a problem that it is required to have a high concentration, and it is difficult to manufacture the composition itself and to stably store it over time. On the other hand, when the pigment concentration is a conventionally common concentration, the film thickness of the pixel film to obtain a desired color density becomes too thick this time, which makes it difficult to manufacture a color filter.

In order to solve this problem, when Pigment Red 179 or Pigment Red 208 suitable for the wavelength of light irradiated from the LED is used, the color density can be obtained without increasing the pigment concentration of the pixel, and the film thickness can be controlled within the range. In this system, there is a problem that the brightness is substantially lowered. Furthermore, it is considered that a red pigment such as Pigment Red 221 is used as a method of maintaining a high coloring power with respect to the wavelength of light emitted from the LED and improving the luminance (for example, see Patent Document 5). However, since the viscosity increase of the pigment red 221 in the dispersion step is increased and it is difficult to ensure the stability of the dispersion over time, suitable fluidity and stability over time of the dispersion cannot be obtained by a known method. [Prior Art Document] [Patent Literature]

Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. 5 Japanese Patent Laid-Open No. 2012-208329

An object of the present invention is to provide a red pigment dispersion resist composition for a color filter which is excellent in dispersion stability, coloring power, contrast, brightness, heat resistance and solvent resistance.

By setting the main pigment to a color index (C.I.) pigment red 221 and the coloring pigment to C.I. Pigment Red 177, it is possible to obtain a red pixel having high luminance and high coloring power even by using various backlight devices. Therefore, it is necessary to atomize the pigment and stably disperse it in the red pigment dispersion resist composition for a color filter. However, the dispersion stability of the fine particles of the pigment containing C.I. Pigment Red 221 cannot be sufficiently obtained by the prior art. Therefore, the applicant has intensively studied a technique for improving the dispersion stability of the pigment fine particles containing CI Pigment Red 221, and as a result, it has been found that the microparticles obtained by micronizing the pigment containing CI Pigment Red 221 are added to the specificity of the present invention. Pigment dispersing aid, acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent and dispersing it to obtain a pigment dispersion, which is then used as a color filter for red pigment dispersion resist The method of composition. In the red pigment dispersion resist composition for a color filter obtained by the method, since the dispersion stability of the pigment fine particles containing CI Pigment Red 221 is remarkably improved as compared with the prior art, the present invention can be completely solved. The subject matter has thus completed the present invention.

That is, the present invention is as follows: 1. A red pigment dispersion resist composition for a color filter containing CI Pigment Red 221, CI Pigment Red 177, represented by Formula (1) and/or Formula (2) Pigment dispersing aid, alkali soluble resin, photopolymerizable compound, photopolymerization initiator and organic solvent, Wherein X and Y are the same or different and each represents a phenyl group which may be substituted by F, Cl, Br, NO ₂ , CH ₃ or OCH ₃ . M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ (R ₁ , R ₂ , R ₃ and R _{4 are the} same or different and represent a carbon number of 1 to 10 which may be substituted by another substituent. A saturated or unsaturated aliphatic hydrocarbon group or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted by another substituent. m represents an integer of 1 or more. 〕

2. A red pigment dispersion resist composition for a color filter, which is a pigment dispersion containing CI Pigment Red 221, a pigment dispersion of CI Pigment Red 177, an alkali-soluble resin, a photopolymerizable compound, and photopolymerization initiation. The color filter of the agent and the organic solvent disperses the resist composition with a red pigment, and the pigment dispersion of the CI Pigment Red 221 is added to the microparticle obtained by atomizing CI Pigment Red 221 into the general formula (1). And/or a pigment dispersion aid represented by the formula (2), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent, and a pigment dispersion obtained by dispersing the same The pigment dispersion of CI Pigment Red 177 is a pigment dispersing aid represented by the formula (1) and/or the formula (2) added to the microparticle obtained by atomizing CI Pigment Red 177, and has a tertiary amine. a pigment dispersion obtained by dispersing an acrylic block copolymer having a base and/or a quaternary ammonium group and an organic solvent, Wherein X and Y are the same or different and represent a phenyl group which may be substituted by F, Cl, Br, NO ₂ , CH ₃ or OCH ₃ , and M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ (R ₁ , R ₂ , R ₃ and R _{4 are the} same or different and represent a saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms which may be substituted by another substituent or a carbon which may be substituted by another substituent An aromatic hydrocarbon group having 6 to 10 atoms.). m represents an integer of 1 or more. 〕

A red pigment dispersion resist composition for a color filter, which is a pigment dispersion containing CI Pigment Red 221, a pigment dispersion of CI Pigment Red 177, an alkali-soluble resin, a photopolymerizable compound, and photopolymerization initiation. The color filter of the agent and the organic solvent disperses the resist composition with a red pigment, and the pigment dispersion of the CI Pigment Red 221 is added to the microparticle obtained by atomizing the CI Pigment Red 221 into the general formula (3). And/or a pigment dispersion aid represented by the formula (4), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent dispersed and dispersed to obtain a pigment dispersion. The pigment dispersion of the CI Pigment Red 177 is a pigment dispersing aid represented by the formula (3) and/or the formula (4) added to the microparticle obtained by atomizing the CI Pigment Red 177, and has a quaternary ammonium salt. a pigment dispersion of the obtained acrylic block copolymer and an organic solvent and dispersing the obtained pigment, Wherein M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ (R ₁ , R ₂ , R ₃ and R _{4 are the} same or different and represent a number of carbon atoms which may be substituted by other substituents a saturated or unsaturated aliphatic hydrocarbon group of 1 to 10 or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted with another substituent. m represents an integer of 1 or more. 〕

4. The red pigment dispersion resist composition for a color filter according to any one of 1 to 3, wherein the pigment dispersion of the CI Pigment Red 221 contains a compound having the same skeleton as CI Pigment Red 221 Sulfonate.

5. The color filter of claim 4, wherein the pigment dispersion of the pigment red 221 is in the presence of a sulfonate of a compound having the same skeleton as CI Pigment Red 221, with a red pigment dispersion resist composition. Adding a pigment dispersing aid represented by the general formula (3) and/or the general formula (4) to a microparticle obtained by atomizing CI Pigment Red 221, having a tertiary amino group and/or a quaternary ammonium group a pigment dispersion obtained by dispersing an acrylic block copolymer and an organic solvent, and the pigment dispersion of the CI Pigment Red 177 is added to the microparticle obtained by atomizing CI Pigment Red 177 into a general formula (3). And a pigment dispersion aid represented by the formula (4), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent dispersed and dispersed.

6. The red pigment dispersion resist composition for a color filter according to any one of 1 to 5, wherein the CI Pigment Red 221 is 100 parts by mass based on the total mass of the CI Pigment Red 221 The pigment dispersion contains 5 to 15 parts by mass of barium sulfate having a primary particle diameter of 5 nm to 20 nm.

A color filter having a contrast ratio (Bare: 1000) of 700 obtained by dispersing a resist composition with a red pigment for a color filter according to any one of 1 to 3. the above.

According to the present invention, the following effects can be obtained. By using a pigment-dispersed resist composition as a color filter, a red filter having a suitable chromaticity x and y is obtained, and a display having a brighter luminance Y is obtained. The film thickness can be reduced while the viscosity of the pigment-dispersed resist composition can be made suitable, and the color filter can be produced without difficulty. The pigment-dispersed resist composition for a color filter can have excellent dispersion stability. A red filter excellent in solvent resistance and heat resistance can be provided.

Hereinafter, the red pigment dispersion resist composition (hereinafter also referred to as "pigment dispersion resist composition") for a color filter of the present invention will be described in further detail. (Pigment) The red pigment dispersion resist composition for a color filter of the present invention is a composition containing CI Pigment Red 221 and CI Pigment Red 177, and the above pigment may be directly added as a color filter for red pigment dispersion resistance. An etchant composition, or a pigment dispersing aid represented by the formula (1) and/or the formula (2), or an acrylic having a tertiary amino group and/or a quaternary ammonium group may be added to the above pigment in advance. The block copolymer and the organic solvent, and if necessary, an alkali-soluble resin is added and dispersed to form a pigment dispersion of CI Pigment Red 221 and a pigment dispersion of CI Pigment Red 177, and then the pigment dispersion is contained. Since the color filter is obtained by dispersing the resist composition containing the pigment dispersion, the color filter can have high contrast, high brightness, high heat resistance, and high solvent resistance.

The content of the CI Pigment Red 221 is preferably 30% by mass or more, less than 100% by mass, more preferably 40% by mass or more, and less than 60% by mass, and preferably CI Pigment Red 177 is less than 70% by mass, based on the total mass of the pigment. More preferably, it is 40 mass % or more and less than 60 mass %. When the content of the above C.I. Pigment Red 221 is less than 30% by mass, a suitable chromaticity x and y may not be obtained as a red filter. Preferably, each of C.I. Pigment Red 221 and C.I. Pigment Red 177 has an average primary particle diameter of 30 nm to 50 nm. By having an average particle diameter within the above range, the image developed by the obtained color filter becomes a higher contrast. In the present invention, the average particle diameter is a volume average particle diameter measured by a laser diffraction type particle size measurement method and a measuring device: Nanotrac (UPA-EX150, manufactured by Nikkiso Co., Ltd.). In the present invention, in addition to the above colored pigment, other pigments may be added in addition to the range which does not impair the effects of the present invention. Examples of the other pigments include a yellow pigment, an orange pigment, and the like. The amount of the pigment used in the present invention is preferably from 5 to 80% by mass, and more preferably from 20 to 50% by mass, based on the total solid content of the pigment-dispersed resist composition as the mass fraction.

(Pigment Dispersing Aid) The pigment dispersing aid contained in the pigment-dispersed resist composition of the present invention preferably contains a pigment dispersing aid as a compound represented by the following formula (1) and/or formula (2). (A) (hereinafter, also referred to as "pigment dispersing aid (A)") and a pigment dispersing aid (B) which is a sulfonate of a compound having the same skeleton as CI Pigment Red 221 (hereinafter, also referred to as " Both of the two pigment dispersing aids of the pigment dispersing aid (B))) may contain only the pigment dispersing aid (A) and no pigment dispersing aid (B). It preferably contains a pigment dispersing aid ( Both A) and the pigment dispersing aid (B).

As the pigment dispersing aid (A) used in the present invention, a compound represented by the above formula (1) and/or formula (2) is used. In the above formula (1) and formula (2), X and Y are the same or different and each represents a phenyl group which may be substituted by F, Cl, Br, NO ₂ , CH ₃ or OCH ₃ . M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ . When M of the above formula (1) and formula (2) is NR ₁ R ₂ R ₃ R ₄ , each of R ₁ , R ₂ , R ₃ and R _{4 is the} same or different and represents a carbon which may be substituted by another substituent. A saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted with another substituent. Here, examples of the saturated or unsaturated aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, and a octyl group. An alkyl group such as a thiol group; an alkenyl group such as a vinyl group, an allyl group or a 1-butenyl group; an alkynyl group such as an ethynyl group or a propynyl group; and the like. Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. Further, examples of the other substituent include a hydroxyl group, a halogen, a carboxyl group, an amine group, and a lower alkyl group (having 1 to 5 carbon atoms). Further, one of R ₁ R ₂ R ₃ and R ₄ may be substituted by another substituent, or two or more of them may be substituted by another substituent. Further, "m" of the above formula (1) and formula (2) is an integer of 1 or more.

In the above-mentioned pigment dispersing aid (A), the compound represented by the above formula (1) is an enol type, and the compound represented by the above formula (2) is a keto type tautomer, and the pigment of the present invention is dispersed. The resist composition may comprise two compounds. In other words, the pigment dispersing aid (A) in the present invention contains the compound represented by the above formula (1) or (2), and the formula represented by the above formula (1) and formula (2). Any of the cases in which both of the compounds are composed. As a preferable example of the pigment dispersing aid (A), even in a state in which the organic pigment is finely dispersed, a pigment having a high level of transparency and coloring power while having good fluidity and dispersion stability can be obtained. From the viewpoint of the dispersion, a sulfonate of CI Pigment Red 2 (general formula (3) and/or formula (4) below) is preferred.

The pigment dispersing aid (A) is used in an amount of 0.5 to 30 parts by mass, preferably 3 to 15 parts by mass, based on 100 parts by mass of the total of the pigments, and is used as a pigment dispersing aid with respect to 100 parts by mass of each pigment. The amount of the sulfonate of the above CI Pigment Red 221 of (B) is 0.5 to 30 parts by mass, preferably 3 to 15 parts by mass.

(Acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group) The pigment dispersion resist composition of the present invention contains an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group Things. As the acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group in the present invention, for example, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2020, DISPERBYK-2025, BYK-LPN21116, BYK can be cited. -LPN22102 (above, BYK).

In the pigment dispersion resist composition of the present invention, the content of the acrylic block copolymer having the above-described tertiary amino group and/or quaternary ammonium group is usually preferably 1 to 100 parts by mass based on 100 parts by mass of the total organic pigment used. 200 parts by mass, more preferably 1 to 60 parts by mass. When the content of the acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group is less than 1 part by mass, the pigment dispersibility may be lowered. On the other hand, when it exceeds 200 parts by mass, the development property may be lowered. The possibility of waiting.

(Alkali Soluble Resin) The pigment dispersion resist composition of the present invention contains an alkali-soluble resin. The alkali-soluble resin is not particularly limited as long as it is an alkali-soluble resin which is soluble in an alkali developing solution, and is preferably used in the development process of the color filter. Among them, the alkali-soluble resin having a carboxyl group is preferable as the alkali-soluble resin, and a copolymer of an ethylenically unsaturated monomer having one or more carboxyl groups and another copolymerizable ethylenically unsaturated monomer is particularly preferable. Specific examples of the copolymer of the ethylenically unsaturated monomer having one or more carboxyl groups and another copolymerizable ethylenically unsaturated monomer include ethylenically unsaturated monomers having a carboxyl group such as acrylic acid or methacrylic acid. And styrene selected from the group consisting of ethylenically unsaturated monomers having a carboxyl group, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, allyl acrylate, allyl methacrylate (allyl methacrylate), benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, glyceryl monoacrylate, glyceryl methacrylate, N-phenyl maleimide, poly A copolymer of at least one ethylenically unsaturated monomer of a styrene macromonomer and a polymethyl methacrylate macromonomer.

The acid value of the above alkali-soluble resin is preferably 50 mg KOH/g to 300 mg KOH/g. At this time, when the acid value is less than 50 mg KOH/g, there is a possibility that the solubility of the resist composition to the alkali developing solution is lowered. On the other hand, when it exceeds 300 mg KOH/g, the solubility in the alkali developing solution becomes too large, and when the image is developed by the alkali developing solution, the surface of the colored layer is peeled off and the surface of the colored layer is present. The possibility of rough film. Further, in the present invention, the acid value is a theoretical acid value, and is a value obtained by arithmetically calculating an ethylenically unsaturated monomer having a carboxyl group and a content thereof.

In the pigment-dispersed resist composition of the present invention, an alkali-soluble resin is contained, and the content thereof is preferably a small amount from the viewpoint of dispersibility and dispersion stability at the time of dispersion of the pigment described later. Therefore, it is preferably contained in at least one of the pigment dispersion of CI Pigment Red 221 and the pigment dispersion of CI Pigment Red 177, and may be added separately from the pigment dispersion to obtain a red pigment for a color filter. The resist composition is dispersed. The mass average molecular weight of the alkali-soluble resin in the present invention is usually preferably 1,000 to 100,000. When the mass average molecular weight of the alkali-soluble resin is less than 1,000, the solubility to the alkali developer may increase and the development characteristics may be lowered. On the other hand, when it exceeds 100,000, the solubility in an organic solvent may fall and the viscosity of a resist composition may raise. Further, in the present invention, the mass average molecular weight of the alkali-soluble resin is a polystyrene-equivalent mass average molecular weight obtained by a colloidal permeation chromatography (GPC, Gel Permeation Chromatography). In the present invention, Water 2690 (manufactured by Waters Corporation) was used as a device, and PLgel 5 μ MIXED-D (manufactured by Polymer Laboratories Co., Ltd.) was used as a column. In the pigment dispersion resist composition of the present invention, the content of the alkali-soluble resin is usually preferably 10 to 1,000 parts by mass, more preferably 20 to 500 parts by mass, per 100 parts by mass of the total organic pigment contained. When the content of the alkali-soluble resin is less than 10 parts by mass, for example, there is a possibility that the alkali developability is lowered or scum is formed on the substrate of the unexposed portion or the light-shielding layer, and the film remains. On the other hand, when it exceeds 1,000 parts by mass, since the concentration of the organic pigment relatively decreases, there is a possibility that it is difficult to achieve the target color density as a film.

(Photopolymerizable Compound) The pigment-dispersed resist composition of the present invention contains a photopolymerizable compound. The photopolymerizable compound of the present invention may, for example, be a monomer or oligomer having one or more photopolymerizable unsaturated bonds in the molecule. The photopolymerizable unsaturated bond is an unsaturated bond which can be polymerized by the following action: The photopolymerization initiator to be described later generates a radical or a cation at the time of decomposition by an active energy ray such as an ultraviolet ray or an electron ray. Examples of the monomer having one photopolymerizable unsaturated bond in the molecule include methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, and butyl acrylate. Or alkyl methacrylate or acrylate such as 2-ethylhexyl acrylate; aryl methacrylate or acrylate such as benzyl methacrylate or benzyl acrylate; Alkoxyalkyl methacrylate or acrylate such as butoxyethyl methacrylate or butoxyethyl acrylate; N,N-methacrylic acid An aminoalkyl methacrylate or acrylate such as methylamine ethyl ester or acrylonitrile-N,N-dimethylamine ethyl ester; diethylene glycol ethyl ether, triethylene glycol butyl ether, two Methacrylic acid or acrylate of polyalkylene glycol alkyl ether such as propylene glycol methyl ether; methacrylic acid of polyalkylene glycol aryl ether such as hexaethylene glycol phenyl ether Ester or Acrylate; isobornyl methacrylate or acrylate; glycerol methacrylate or acrylate; 2-hydroxyethyl methacrylate or acrylate.

Further, examples of the monomer having two or more photopolymerizable unsaturated bonds in the molecule include bisphenol A methyl diacrylate, 1,4-butanediol diacrylate methyl ester, and 1,3-butylene glycol diacrylic acid. Methyl ester, diethylene glycol diacrylate, methyl glyceryl diacrylate, methyl neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate Methyl ester, trimethylolpropane trimethyl acrylate, pentaerythritol trimethyl acrylate, pentaerythritol tetramethyl acrylate, dipentaerythritol tetramethyl acrylate, dipentaerythritol methyl hexaacrylate, dipentaerythritol methyl pentoxide, bisphenol A Acrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, diethylene glycol diacrylate, glyceryl diacrylate, neopentyl glycol diacrylate, polyethylene Alcohol diacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol Acrylate, dipentaerythritol pentaacrylate, and the like. These monomers may be used singly or in combination of two or more kinds. In the present invention, the content of the photopolymerizable compound is preferably in the range of 3 to 50% by mass based on the total solid content in the pigment-dispersed resist composition.

(Photopolymerization Initiator) The pigment dispersion resist composition of the present invention contains a photopolymerization initiator. The photopolymerization initiator in the present invention is not particularly limited as long as it generates radicals or cations by irradiation with an active energy ray such as ultraviolet rays or electron beams, and examples thereof include benzophenone and N, N'-. Tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, benzil, 2,2-diethoxy Acetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutyl benzophenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxyl ring Hexyl benzophenone, tert-butyl hydrazine, 1-chloroindole, 2,3-dichloropurine, 3-chloro-2-methylindole, 2-ethyl hydrazine, 1,4-naphthoquinone, 1,2-benzopyrene, 1,4-dimethylhydrazine, 2-phenylhydrazine, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropane- 1-ketone, triazine-based photopolymerization initiator, and the like. These photopolymerization initiators may be used alone or in combination of two or more. In the present invention, the content of the photopolymerization initiator is preferably in the range of 1 to 20% by mass based on the total solid content of the pigment-dispersed resist composition.

(Organic solvent) The pigment dispersion of the present invention contains an organic solvent. The organic solvent in the present invention can be exemplified by an organic solvent which is suitably used in the fields of inks, paints, liquid crystal color filter resists, and ink jets. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, and diethyl ether can be exemplified. Glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl Ether organic solvent such as ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate An ether ester organic solvent such as propylene glycol monoethyl ether acetate; a ketone organic solvent such as methyl isobutyl ketone, cyclohexanone, 2-heptanone or δ-butyrolactone; 2-hydroxypropionic acid Methyl ester, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 3-methyl-3-methoxybutylpropionate, methyl 3-methoxypropionate, Ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, n-amyl formate, etc. Ester organic solvent; alcohol solvent such as methanol, ethanol, isopropyl alcohol or butanol; N a nitrogen-containing organic solvent such as methylpyrrolidone, N,N-dimethylformamide or N,N-dimethylacetamide. These may be used alone or in combination of two or more.

Among these organic solvents, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, ethylene glycol monomethyl ether acetate, and propylene glycol are preferable in terms of solubility, dispersibility, coatability, and the like. Monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, ethyl 2-hydroxypropionate, 3-methyl-3-methoxybutyl propionate, Ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, n-amyl formate, etc., more preferably propylene glycol monomethyl ether acetate. Furthermore, the organic solvent is preferably contained in the red pigment dispersion resist composition in an amount of 50% by mass or more, and more preferably 70% by mass or more, from the viewpoints of the solubility of the alkali-soluble resin, the pigment dispersibility, and the coating property. .

(Other components) In order to improve the heat resistance and brightness of the pigment dispersion of the present invention, it is preferable to contain barium sulfate. In the present invention, the content of barium sulfate is 0 to 15% by mass, preferably 5 to 12% by mass based on 100 parts by mass of each of the above pigments. When the above barium sulfate exceeds 15 parts by mass, the coloring power is largely lowered. Preferably, the barium sulfate has a primary particle diameter of 5 nm to 20 nm. When the primary particle diameter of the above-mentioned barium sulfate exceeds 20 nm, there is a tendency that the contrast is lowered and foreign matter is generated. The above barium sulfate is used in the dispersion or after dispersion of the microparticulated pigment. Further, the pigment-dispersed resist composition of the present invention may suitably use various additives such as a thermal polymerization inhibitor, an ultraviolet absorber, and an antioxidant as needed.

(Method for Producing Pigment Dispersion) The pigment dispersion in the present invention can be produced, for example, from the above constituent materials by the following production method. First, each untreated pigment is subjected to a microparticulation treatment (salt grinding treatment) to obtain a microparticulated pigment. More preferably, the microparticulation treatment is carried out in the presence of a pigment dispersing aid which is a sulfonate of a compound having the same skeleton as each pigment. By performing the microparticulation treatment in the presence of a pigment dispersing aid which is a sulfonate of a compound having the same skeleton as each pigment, it is possible to uniformly refine the pigment while suppressing crystallization of the pigment. The particle size of the dispersion composed of the finely divided pigment is about 50 nm to 70 nm. The amount of the pigment dispersing aid to be used is 0.5 to 30 parts by mass, preferably 3 to 10 parts by mass, per 100 parts by mass of the pigment. In the above-mentioned micronization treatment, a kneading apparatus that performs a revolving motion while rotating the three stirring blades, and a sulfonate having a compound having the same skeleton as the pigment, may be used. The pigment is ground by an inorganic salt to thereby further coarsen the primary particle diameter of the pigment. The pigment obtained by salt-milling treatment in the presence of such a sulfonate having a compound having the same skeleton as the pigment is atomized to further make the primary particle diameter finer and more uniform. In addition, the salt grinding treatment of the kneading device that performs the revolving motion while rotating the three stirring blades, respectively, is also referred to as TRI-MIX treatment.

The TRI-MIX process will be described in further detail below. The TRI-MIX treatment is a water-soluble dispersion medium (hereinafter, also simply referred to as "dispersion medium") containing a pigment, a water-soluble inorganic salt (hereinafter, simply referred to as "inorganic salt"), and a substantially insoluble inorganic salt. The mixture is kneaded by a kneading device in which three stirring blades are rotated while performing a revolving motion, and then the inorganic salt and the dispersion medium are removed. In this process, a kneading device is used as a kneading device to perform planetary motion, that is, a kinematic motion that performs a revolving motion while performing a spin motion. Accordingly, the dead edges of the agitating blades and the agitating blades and the inner surface of the device become very small, and a stronger and uniform shearing force can be obtained. The particle diameter of the pigment which is subjected to the grinding treatment by the inorganic salt under the shearing force becomes finer and uniform than the primary particle diameter, and a color filter having higher transparency and contrast ratio than conventional ones can be obtained. Here, the "revolving motion" refers to a movement in which a stirring blade is rotated in a tank. Further, the "kneading device for causing the stirring blade to revolve" refers to a kneading device that originally moves the agitating blade itself to perform a circular motion in the groove. However, in the present specification, as long as the relative movement of the groove and the stirring blade is the same (for example, the groove is rotated, etc.), the kneading device is included in the "kneading device for causing the stirring blade to perform the revolving motion".

Further, as the structure of the kneading device, it is preferable to satisfy the following conditions (1) and (2). (1) A triangle obtained by taking a point at which three rotation axes intersect as a vertex is an equilateral triangle with respect to a plane orthogonal to the rotation axes of the three agitating blades. (2) The revolution axis intersects at the center of gravity of the equilateral triangle. Further, the agitating blade preferably has a width from the bottom of the groove to the liquid surface and a width from the inner wall of the groove to the center. As such a kneading device, for example, TRI-MIX (manufactured by Inoue Co., Ltd.) or the like can be mentioned. Further, in this treatment, a wet treatment method in which a pigment, an inorganic salt, and a dispersion medium are added to the tank for kneading can be used. The inorganic salt is not particularly limited as long as it is water-soluble, but from the viewpoint of cost, it is preferred to use a salt (sodium chloride). Further, the particle diameter of the inorganic salt is preferably 200 μm or less, and more preferably 50 μm or less. According to this, the particle diameter of the colored pigment can be made finer and more uniform than the primary particle diameter. In the present invention, the particle diameter of the inorganic salt is a volume average particle diameter measured by a laser diffraction type particle size measurement method and a measuring device: Nanotrac (UPA-EX150, manufactured by Nikkiso Co., Ltd.).

The dispersion medium is not particularly limited as long as it is a water-soluble dispersion medium having the following two conditions, that is, water-soluble and insoluble inorganic salts. Among them, a high boiling point solvent having a boiling point of 120 ° C or higher is preferred from the viewpoint of safety because the temperature at the time of salt milling is increased and the solvent is easily evaporated. Examples of such a water-soluble dispersion medium include 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, and 1-methoxy- Alkoxy alcohols such as 2-propanol and 1-ethoxy-2-propanol; binary of diethylene glycol, triethylene glycol, liquid polyethylene glycol, dipropylene glycol, and low molecular weight polypropylene glycol Alcohols; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol single B An ether or the like such as a group ether.

As a method of performing TRI-MIX treatment using the above materials and apparatuses, the following methods etc. are mentioned. A pigment, a pigment dispersing aid as a sulfonate of a compound having the same skeleton as each pigment, an inorganic salt, and a dispersion medium are added to the tank. Next, the three stirring blades of the kneading device were subjected to a revolving motion while performing a revolving motion to grind the pigment with an inorganic salt. Thereafter, the substance added with warm water to be slurried was filtered and the residual inorganic salt and the dispersion medium were removed by washing with water. In the grinding treatment of the pigment, it is preferred to appropriately adjust the amount of addition (viscosity) of the material, the inner diameter of the groove, and the like in order to sufficiently exert the stress for kneading. For example, it is preferable to carry out preparation and treatment so that the load current at the time of processing using the said TRI-MIX becomes the range of 50-85 % of the rated current value of an engine. Next, an acrylic block copolymer comprising the above-mentioned respective microparticles and the above-described tertiary amino group and/or quaternary ammonium group, the above pigment dispersing aid (A), the above alkali-soluble resin, an organic solvent, and sulfuric acid as needed are obtained. Each mixture of mash. Each of the obtained mixtures is kneaded and dispersed by various dispersing machines such as a roll mill, a kneader, a high-speed stirring device, a bead mill, a ball mill, a sand mill, an ultrasonic disperser, and a high-pressure disperser to obtain respective pigments. Dispersion. Further, the pigment dispersion may contain a photopolymerizable compound in advance.

(Method for Producing Pigment Dispersion Resist Composition) A method of obtaining the pigment dispersion resist composition of the present invention from each pigment dispersion will be described. The method of obtaining the pigment-dispersed resist composition of the present invention from each pigment dispersion can be obtained, for example, by the following (1) and (2). (1) The pigment mixture of CI Pigment Red 221 and the pigment dispersion of CI Pigment Red 177 pigment dispersion are mixed to a predetermined pigment ratio, and then a photopolymerizable compound, a photopolymerization initiator, the remaining alkali-soluble resin, and an organic solvent are added. A solvent, barium sulfate as needed, to obtain a pigment dispersion resist composition. (2) A photopolymerizable compound, a photopolymerization initiator, a remaining alkali-soluble resin, an organic solvent, and if necessary, barium sulfate are added to each pigment dispersion to obtain a pigment dispersion resist composition, and then CI pigment red is added. The 264 pigment dispersion resist composition was mixed with the CI Pigment Red 177 pigment dispersion resist composition to have a predetermined pigment ratio, thereby obtaining a pigment dispersion resist composition.

A color filter is produced by using the pigment-dispersed resist composition obtained by the above method to have a predetermined film thickness, whereby a color filter having a contrast ratio (Bare: 1000) of 700 or more can be obtained. In addition, the measurement conditions of the contrast in the present invention are as follows. The film thickness of the color filter is 1.0 μm, and the color characteristics (x, y, Y) of each resist are measured by a spectrophotometer (manufactured by Shimadzu Corporation). The values measured by UV-2500PC and C light source 2° field of view were the contrasts (Bare: 1000) when chromaticity x = 0.6730 and y = 0.3200. In the present invention, the contrast is more preferably 700 or more (Bare: 1000), still more preferably 705 or more. [Examples]

The invention is further illustrated by the following examples, but the invention is not limited to the examples. In the absence of a special statement, "%" means "% by mass" and "part" means "parts by mass". In addition, in this manual, "TRI-MIX" is a registered trademark of Inoue Manufacturing Co., Ltd., and "Yan Jia Gu" is a registered trademark of Ciba Japan.

<Pigment Dispersing Aid> (C.I. sulfonate of Pigment Red 221) 30 ml of concentrated sulfuric acid was placed in a 100 ml Erlenmeyer flask, and 10 g of C.I. Pigment Red 221 was added while stirring with a magnetic stirrer, and the mixture was stirred at room temperature for 30 minutes. A mixture of 50 g of water and 50 g of ice was placed in a 1 L beaker, and the above reaction was poured into the ice water, and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed with water under reduced pressure, and the obtained solid was dried to obtain 12 g of a sulfonate of C.I. Pigment Red 221. (C.I. sulfonate of Pigment Red 2) 30 ml of concentrated sulfuric acid was placed in a 100 ml Erlenmeyer flask, and 10 g of C.I. Pigment Red 2 was added while stirring with a magnetic stirrer, and the mixture was stirred at room temperature for 30 minutes. A mixture of 50 g of water and 50 g of ice was placed in a 1 L beaker, and the above reaction was poured into the ice water, and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed with water under reduced pressure, and the obtained solid was dried to obtain 12 g of a sulfonate of C.I. Pigment Red 2. (C.I. sulfonate of Pigment Orange 71) 30 ml of concentrated sulfuric acid was placed in a 100 ml Erlenmeyer flask, and 10 g of C.I. Pigment Orange 71 was added while stirring with a magnetic stirrer, and the mixture was stirred at room temperature for 30 minutes. A mixture of 50 g of water and 50 g of ice was placed in a 1 L beaker, and the above reaction was poured into the ice water, and stirred with a magnetic stirrer for 30 minutes. This was filtered and washed with water under reduced pressure, and the obtained solid was dried to obtain 12 g of a sulfonate of C.I. Pigment Orange 71.

<Micronization treatment> Preparation Example 1 (Micronization treatment PR221 (Pigment Red 221)) 800 parts of CI Pigment Red 221 and 8000 parts of particle size 20 were placed in a tank of TRI-MIX TX-15 (trade name, manufactured by Inoue Seisakusho Co., Ltd.). Mm of sodium chloride, 1920 parts of diethylene glycol. The salt milling treatment was carried out in a range of 70% of the rated current value of 9.3 A and kneading at 45 ° C for 3 hours. Next, 1300 parts of the obtained kneaded product was placed in 3 liters of warm water, and stirred while heating at 70 ° C for 1 hour to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40 ° C for a day and night to obtain 720 parts of micronized PR221.

Preparation Example 2 (Microparticulation Treatment of Pigment Dispersing Agent PR221 (Pigment Red 221)) 800 parts of CI Pigment Red 221 and 40 parts of CI Pigment were placed in a tank of TRI-MIX TX-15 (trade name, manufactured by Inoue Seisakusho Co., Ltd.). Red 221 sulfonate, 8000 parts of 20 μm sodium chloride, 1920 parts of diethylene glycol. The salt milling treatment was carried out in a range of 70% of the rated current value of 9.3 A and kneading at 45 ° C for 3 hours. Next, 1300 parts of the obtained kneaded product was placed in 3 liters of warm water, and stirred while heating at 70 ° C for 1 hour to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40 ° C for one day and night to obtain 740 parts of microparticulate PR221 containing a pigment dispersing aid.

Preparation Example 3 (Micronization treatment of pigment-containing dispersing aid PR254 (Pigment Red 254)) 800 parts of CI Pigment Red 254 and 40 parts of CI Pigment were placed in a tank of TRI-MIX TX-15 (trade name, manufactured by Inoue Seisakusho Co., Ltd.). Sulfide of orange 71, 8000 parts of sodium chloride having a particle size of 20 μm, and 1920 parts of diethylene glycol. The salt milling treatment was carried out in a range of 70% of the rated current value of 9.3 A and kneading at 45 ° C for 3 hours. Next, 1300 parts of the obtained kneaded product was placed in 3 liters of warm water, and stirred while heating at 70 ° C for 1 hour to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40 ° C for one day and night to obtain 740 parts of microparticulate PR254 containing a pigment dispersing aid.

Preparation Example 4 (Micronized Treatment of PR177 (Pigment Red 177)) 800 parts of CI Pigment Red 177 and 8000 parts of chlorination having a particle size of 20 μm were placed in a tank of TRI-MIX TX-15 (trade name, manufactured by Inoue Co., Ltd.). Sodium, 1920 parts of diethylene glycol. The salt milling treatment was carried out in a range of 70% of the rated current value of 9.3 A and kneading at 45 ° C for 3 hours. Next, 1300 parts of the obtained kneaded product was placed in 3 liters of warm water, and stirred while heating at 70 ° C for 1 hour to obtain a slurry. After repeatedly filtering and washing with water to remove sodium chloride and diethylene glycol, it was dried at 40 ° C for one day and night to obtain 720 parts of micronized PR177.

<Acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group> BYK-LPN22102 (manufactured by BYK), solid content concentration 40% by mass <alkali soluble resin> BzMA/MAA copolymerization (benzyl methacrylate/methacrylic acid copolymer, theoretical acid value: 120 mg KOH/g, mass average molecular weight: 25,000) <Photopolymerizable compound> DPEHA (dipentaerythritol hexaacrylate) <Photopolymerization initiator> Yan Jiagu 369 (manufactured by Ciba Japan, 2-benzyl-2-(dimethylamino)-1-(4-morpholinylphenyl)-butanone-1) <Organic solvent> PGMEA (propylene glycol monomethyl) Ethyl ether acetate) <Barium sulfate> BF-40 (average primary particle size 0.01 μm, manufactured by Nippon Chemical Industry Co., Ltd.)

(Production of Dispersion and Resist Composition) <Red Pigment Dispersion> In order to achieve the composition of Table 1, each of the fine particles for each dispersion was mixed with other components and used in a bead mill at 40 ° C to 50 ° The mixture was kneaded at a temperature of ° C for 3 hours to obtain each red pigment dispersion. <Pigment-dispersed resist composition for color filter> Each pigment dispersion composition obtained by the above-mentioned process and other materials (BzMA/MAA copolymer, DPEHA, Yanjiagu, PGMEA) are shown in Table 1. The composition was uniformly mixed using a high-speed mixer, and then filtered with a filter having a pore size of 3 μm to obtain a red pigment-dispersed resist composition for each color filter.

<Red pigment dispersion resist composition for color filters of the examples and the comparative examples> Each color filter was dispersed with a red pigment to form a resist composition in order to be Table 2-1, Table 2-2, and Table 2 The blending shown in FIG. 3 was combined to obtain red pigment dispersion resist compositions for color filters of Examples 1 to 9 and Comparative Examples 1 to 3.

Evaluation method The following evaluations were carried out, and the evaluation results are shown in Table 1 and Table 2-1, Table 2-2, and Table 2-3. <Viscosity> The pigment-dispersed resist compositions for color filters of the examples and the comparative examples were collected into glass bottles, sealed, and stored at room temperature for one day, and then an E-type viscometer was used (Dongji Industry Co., Ltd.) Company, R100 viscometer, model RE100L) The viscosity at 25 ° C was measured. The lower the viscosity, the better the fluidity, which means that the work is more excellent in the pigment dispersion.

<Dispersion stability> The pigment dispersion resist compositions for color filters of the examples and the comparative examples were each collected in a glass bottle, sealed for 7 days at room temperature, and then evaluated in accordance with the following evaluation criteria. . ○: No thickening or sedimentation was found. △: It was found that the original thickening and sedimentation were restored when gently oscillated. ×: It was found that even if it was strongly shaken, the original thickening and sedimentation were not restored.

<Evaluation of Color Characteristics of Pigment Dispersion Resist Composition for Color Filters> The color characteristics (x, y, Y) of the respective resists of the examples and the comparative examples having a film thickness of 1.0 μm were used for spectrophotometry. The measurement was carried out (Shimadzu Corporation, UV-2500PC, C light source 2° field of view). Here, in Examples 1 to 3 and Comparative Example 1, the contrast, the luminance Y, and the film thickness at the chromaticity x = 0.6730 and y = 0.3200 were obtained. In Examples 4 to 6 and Comparative Example 2, the contrast, the luminance Y, and the film thickness at the chromaticity x = 0.6700 and y = 0.3122 were obtained. In Examples 7 to 9 and Comparative Example 3, the contrast, the luminance Y, and the film thickness at the chromaticity x = 0.6800 and y = 0.3150 were obtained.

<Heat resistance> The pigment dispersion resist composition for color filters of the examples and the comparative examples was applied onto a glass substrate by a spin coater to have a film thickness of 1.0 μm, and prebaked at 100 ° C. (pre-bake) was exposed to a high pressure mercury lamp after 3 minutes, and further post-bake at 270 ° C for 60 minutes. Then, the surface of the obtained resist coating film was observed with a microscope (manufactured by KEYENCE Co., Ltd., VHS-500, magnification: 500 times), and the degree of surface roughness accompanying the sublimation of the pigment in post-baking was observed, and The evaluation criteria were evaluated as follows. ○: no surface roughness was found ×: surface roughness was found

<Solvent Resistance> The test substrate used for the evaluation of the above color characteristics was immersed in N-methylpyrrolidone for 30 minutes. After the substrate was taken out, it was evaluated according to the following evaluation criteria. ○: No dissolution of the coating film was observed. ×: Dissolution of the coating film was found.

[Table 1]

[table 2-1] [Table 2-2] [Table 2-3]

According to the examples of the first to third embodiments, when the luminance of the color filter is required to be chromaticity x=0.6730 and y=0.3200, the brightness is 15.90 to 16.00. Further, the contrast at this time is substantially higher than any of 730 in the first and second embodiments with respect to 1000 in Bare, and is sufficiently high at 530 according to the third embodiment. Further, any of the color filters of Examples 1 to 3 was excellent in heat resistance and solvent resistance. On the other hand, according to Comparative Example 1 in which C.I. Pigment Red 221 was not used, the obtained color filter had good luminance, but was inferior in contrast, heat resistance, and solvent resistance. The same tendency was also confirmed in the combination of Example 4 to Example 6 and Comparative Example 2, and also in the combination of Example 7 to Example 9 and Comparative Example 3. From the above results, it is understood that a more remarkable effect can be exhibited by using C.I. Pigment Red 221 as compared with the use of C.I. Pigment Red 254.

no.

Claims (7)

A color filter using a red pigment dispersion resist composition containing CI Pigment Red 221, CI Pigment Red 177, a pigment dispersing aid represented by the formula (1) and/or the formula (2), and an alkali solubility a resin, a photopolymerizable compound, a photopolymerization initiator, and an organic solvent, wherein In the general formula (1) and/or the general formula (2), X and Y are the same or different and each represents a phenyl group which may be substituted by F, Cl, Br, NO ₂ , CH ₃ or OCH ₃ , and M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ , wherein R ₁ , R ₂ , R ₃ and R _{4 are the} same or different, and represent a saturated or unsaturated one having 10 to 10 carbon atoms which may be substituted by other substituents. An aliphatic hydrocarbon group or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted by another substituent, and m represents an integer of 1 or more. A red pigment dispersion resist composition for a color filter, which is a pigment dispersion containing CI Pigment Red 221, a pigment dispersion of CI Pigment Red 177, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and The color filter of the organic solvent disperses the resist composition with a red pigment, wherein the pigment dispersion of the CI Pigment Red 221 is added to the microparticle obtained by atomizing the CI Pigment Red 221 into the general formula (1). And/or a pigment dispersion aid represented by the formula (2), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent, and a pigment dispersion obtained by dispersing the same The pigment dispersion of the CI Pigment Red 177 is a pigment dispersion aid represented by the formula (1) and/or the formula (2) added to the microparticles obtained by atomizing the CI Pigment Red 177, and has a three-stage a pigment dispersion obtained by dispersing an amine group and/or a quaternary ammonium group-containing acrylic block copolymer and an organic solvent, In the general formula (1) and/or the general formula (2), X and Y are the same or different and each represents a phenyl group which may be substituted by F, Cl, Br, NO ₂ , CH ₃ or OCH ₃ , and M represents H, Na, K, NH ₄ or _{NR 1 R 2 R 3 R 4} , wherein R _1, R _2, identical or different, R ₃ and R _4, represents may be saturated other carbon atoms substituted with 1 to 10 or unsaturated An aliphatic hydrocarbon group or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted by another substituent, and m represents an integer of 1 or more. A red pigment dispersion resist composition for a color filter, which is a pigment dispersion containing CI Pigment Red 221, a pigment dispersion of CI Pigment Red 177, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator, and The color filter of the organic solvent disperses the resist composition with a red pigment, wherein the pigment dispersion of the CI Pigment Red 221 is added to the microparticle obtained by atomizing the CI Pigment Red 221 into the general formula (3). And/or a pigment dispersion aid represented by the formula (4), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent dispersed and dispersed to obtain a pigment dispersion. The pigment dispersion of the CI Pigment Red 177 is a pigment dispersing aid represented by the formula (3) and/or the formula (4) added to the microparticles obtained by atomizing the CI Pigment Red 177, and has four grades. a pigment dispersion obtained by dispersing an ammonium-based acrylic block copolymer and an organic solvent, wherein In the general formula (3) and/or the general formula (4), M represents H, Na, K, NH ₄ or NR ₁ R ₂ R ₃ R ₄ , wherein R ₁ , R ₂ , R ₃ and R _{4 are the} same or different And a saturated or unsaturated aliphatic hydrocarbon group having 1 to 10 carbon atoms which may be substituted by another substituent or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may be substituted with another substituent, and m represents an integer of 1 or more. The red pigment dispersion resist composition for a color filter according to any one of claims 1 to 3, wherein the pigment dispersion of the CI Pigment Red 221 contains a pigment red with CI Pigment 221 A sulfonate of a compound of the same backbone. The red pigment dispersion resist composition for a color filter according to claim 4, wherein the pigment dispersion of the pigment red 221 is a sulfonate of a compound having the same skeleton as CI Pigment Red 221 The pigment dispersing aid represented by the formula (3) and/or the formula (4), having a tertiary amine group and/or four is added to the microparticles obtained by atomizing the CI Pigment Red 221 in the presence of the pigment. a pigment dispersion obtained by dispersing an ammonium-based acrylic block copolymer and an organic solvent, and the pigment dispersion of the CI Pigment Red 177 is a microparticle obtained by atomizing CI Pigment Red 177 Adding and dispersing a pigment dispersing aid represented by the formula (3) and/or the formula (4), an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent Pigment dispersion. The red pigment-dispersed resist composition for a color filter according to any one of the first to fifth aspect, wherein the total mass of the CI Pigment Red 221 is 100 parts by mass, The pigment dispersion of CI Pigment Red 221 contains 5 to 15 parts by mass of barium sulfate having a primary particle diameter of 5 nm to 20 nm. A color filter which has a contrast ratio of a color filter obtained by dispersing a resist composition of a red color pigment for a color filter according to any one of claims 1 to 3 Bare: 1000 is 700 or more.