JP2006265528A - Pigment dispersant and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colored composition for a color filter wherein the generation of a foreign matter, the increase of viscosity and the reduction of its storage stability are prevented even when a pigment concentration is high so that a color filter having an excellent transparency and color quality can be produced. <P>SOLUTION: The pigment dispersant contains the following (a) constituent alone or the following (a) constituent and the following (b) constituent. The (a) constituent is a pigment composite of a diketopyrrolopyrrole pigment having a sulfonic acid group and a diketopyrrolopyrrole pigment having no sulfonic acid group wherein a number of sulfonic acid groups per molecule of the composite diketopyrrolopyrrole pigment is 0.05-0.5. A (b) constituent is a dye other than the above (a) constituent, the dye having a group of a sulfonic acid group, its metal salt, its ammonium salt or its amine salt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coloring composition for a color filter used for producing a pigment dispersant, a liquid crystal color display, an imaging device, and the like, and a color filter using the same. More specifically, the present invention relates to a coloring composition for a color filter excellent in pigment dispersibility, transparency, fluidity and storage stability, and a color filter using the same.

  Color filters used in liquid crystal displays, etc. are currently applied to a substrate by spin coating, coating, or transfer methods with a colored composition in which a pigment is dispersed in a photoresist, and then light and energy rays are passed through a photomask. It is mainly produced by forming pixels by exposure and development. At that time, a diketopyrrolopyrrole pigment is usually used as a pigment for forming a red pixel, but the pigment is not sufficiently dispersed only by dispersing the pigment together with a resin and a solvent with a normal disperser. Therefore, when the dispersion (which may mean “color composition for color filter”) is used for forming a color pixel (hereinafter simply referred to as “pixel”) of a color filter, the resulting red pixel is made transparent. This pixel was insufficient in transmittance as a color filter pixel, and the red pigment was unsatisfactory as a pigment for a color filter coloring composition.

  Further, as the resin used for the photoresist, an acrylic polymer having a high acid value is mainly employed because an alkaline aqueous solution can be used as a patterning developer. However, in a pigment dispersion composed of the above-mentioned pigment and a high acid value acrylic resin, aggregation of pigment particles occurs, the viscosity of the pigment dispersion tends to increase, and the viscosity of the pigment dispersion increases with time. The storage stability of the pigment dispersion is often poor.

  When preparing a color filter with a pigment dispersion with the above difficulties, the pigment dispersion is applied to a substrate by spin coating and film formation is performed, and then the colored film is pixelated. When the color filter composition is thick or the color composition for the color filter has a thixotropic viscosity, the central part of the coating layer before pixelation rises. This causes a hue difference or a density difference between the pixel formed in the central portion of the substrate and the pixel formed in the peripheral portion.

  Therefore, although the coloring composition for color filters (pigment dispersion) is usually in a high concentration range where the pigment concentration is 5 to 20% by mass, the dispersion state is such that the pigment particles are not aggregated with each other. It must be low in viscosity (for example, about 5 to 20 mPa · s) and excellent in storage stability as compared with typical ordinary dry paints and baking paints.

In order to satisfy the above requirements, conventionally, when the red pigment is a diketopyrrolopyrrole pigment (for example, CI Pigment Red 254), the diketopyrrolopyrrolesulfonic acid having a sulfonation degree of 1 or more per molecule. Has been proposed to be added to the pigment, or the pigment is treated with the sulfonated product (Patent Document 1).
JP 2000-160084 A

  On the other hand, the use of liquid crystal display devices has been expanded from monitors for personal computers to color displays for color televisions, and there has been a growing demand for further improvements in color filters, improving pixel transparency and transmitting pixels. It has become necessary to increase the contrast of light and increase the pigment concentration in the pixel.

  However, in the method using the sulfonated product, it is possible to improve the transparency of the pixel by improving the dispersibility of the pigment, and to prevent an increase in the viscosity of the pigment dispersion and a decrease in storage stability due to an increase in pigment concentration It is difficult, and it is difficult to control the reaction when diketopyrrolopyrrole pigment is sulfonated. When a sulfonated product having a large number of sulfonic groups introduced therein is used as a pigment dispersant, foreign matter is not contained in the resulting pigment dispersion. There is a need to improve these.

  The present inventors have solved the above-mentioned problems when using the sulfonated diketopyrrolopyrrole pigment in the coloring composition for high pigment concentration color filters, and improved the color quality of the coloring composition for color filters. As a result of diligent research to make it possible to prevent the occurrence of viscosity and foreign matter, the use of a sulfonated diketopyrrolopyrrole pigment complex with the number of sulfone groups controlled to 0.05 to 0.5 as a pigment dispersant The viscosity of the coloring composition for filters can be lowered, the thickening gelation of the coloring composition during storage can be prevented, the generation of foreign matters is prevented, and the transparency of the most important pixel as a color filter Has been found to be improved, and the present invention has been completed.

  The above object is achieved by the present invention described below. That is, this invention provides the pigment dispersant characterized by including the following (a) component alone or the following (a) component and the following (b) component. When the component (a) and the following component (b) are used in combination, the mass ratio of the component (a) to the component (b) is preferably a: b = 10: 90 to 90:10.

Component (a): a pigment complex of a diketopyrrolopyrrole pigment having a sulfone group and a diketopyrrolopyrrole pigment having no sulfone group, the sulfone per molecule of the diketopyrrolopyrrole pigment in the complex A pigment composite having 0.05 to 0.5 groups.

（但し、式中のＸ₁は水素原子、ハロゲン原子、アルキル基またはアシルアミノ基であり、Ｙ₁は、アントラキノニルアミノ基、フェニルアミノ基、ナフチルアミノ基或いはフェノキシ基であり、これらの基は置換基としてハロゲン原子、アルキル基またはアシルアミノ基を含んでいてもよい。Ｒ₁は水素原子、アルキル基またはフェニル基であり、Ｒ₂はアルキレン基、フェニレン基、或いはナフチレン基であって、これらは置換基を含んでいてもよい。） Component (b): a dye other than the component (a) having a sulfone group, a metal salt thereof, an ammonium salt thereof or an amine salt thereof.
The component (b) is not particularly limited, but is a compound represented by the following general formula (I), general formula (II), general formula (III) or general formula (IV), its metal salt, ammonium salt, and An amine salt is preferred.

(In the formula, X ₁ is a hydrogen atom, a halogen atom, an alkyl group or an acylamino group; Y ₁ is an anthraquinonylamino group, a phenylamino group, a naphthylamino group or a phenoxy group, and these groups are The substituent may contain a halogen atom, an alkyl group or an acylamino group, R ₁ is a hydrogen atom, an alkyl group or a phenyl group, R ₂ is an alkylene group, a phenylene group or a naphthylene group, (It may contain a substituent.)

（但し、式中のＸ₁は水素原子、ハロゲン原子またはアルキル基であり、Ｒ₁は水素原子、アルキル基またはフェニル基であり、Ｒ₂はフェニル基、或いはナフチル基であって、これらは置換基を含んでいてもよく、ｋは化合物へのスルホン基の平均個数であり、０．５〜２の数である。）

(However, X ₁ in the formula is a hydrogen atom, a halogen atom or an alkyl group, R ₁ is a hydrogen atom, an alkyl group or a phenyl group, R ₂ is a phenyl group or a naphthyl group, and these are substituted. And k is the average number of sulfone groups in the compound and is a number from 0.5 to 2.)

（但し、式中のＲ₁は、水素原子、ハロゲン原子、水酸基、アルキル基、無置換または置換のアリール基、無置換または置換のフタルイミド基であり、Ｒ₂は、水素原子または水酸基であり、Ｒ₃は、ハロゲン原子であり、ｍは０〜４の整数を表わし、ｎは化合物へのスルホン基の平均導入個数であり、０．５〜４の数である。）

(In the formula, R ₁ is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted phthalimide group, and R ₂ is a hydrogen atom or a hydroxyl group; R ₃ is a halogen atom, m represents an integer of 0 to 4, n is the average number of sulfone groups introduced into the compound, and is a number of 0.5 to 4.)

（但し、式中のＲ₁およびＲ₂は、互いに独立して、水素原子、ハロゲン原子、シアノ基、アルキル基またはフェニル基である。） In the pigment dispersant of the present invention, the diketopyrrolopyrrole pigment having no sulfone group is represented by the following general formula (V); and the sulfone group of the diketopyrrolopyrrole pigment having a sulfone group is It is preferably at least one selected from a free sulfone group, a metal salt of a sulfone group, an amine salt and an ammonium salt.

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group or a phenyl group.)

In the pigment dispersant of the present invention, R _{2 in the} general formula (I) is taurine, N-methyltaurine, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, sulfanilic acid, 4-chloroaniline. -3-sulfonic acid, 2-nitroaniline-4-sulfonic acid, 2-aminophenol-4-sulfonic acid, o-anisidine-5-sulfonic acid, p-anisidine-5-sulfonic acid, o-toluidine-4- Sulfonic acid, m-toluidine-4-sulfonic acid, p-toluidine-2-sulfonic acid, 2-chloro-p-toluidine-3-sulfonic acid, 3-amino-6-chloro-4-sulfobenzoic acid, 1- Amino-8-naphthalenesulfonic acid, 2-amino-1-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, 6-amino-1-naphthalene It is preferred from an amine selected from sulfonic acid and 5-amino-3-naphthalenesulfonic acid is a group obtained by removing an amino group.

In the pigment dispersant of the present invention, R _{2 in the} general formula (II) is aniline, N-methylaniline, toluidine (o-, m- or p-), anisidine (o-, m- or p). A group obtained by removing an amino group from an amine selected from-), chloroaniline (o-, m- or p-), diphenylamine, 1-naphthylamine and 2-naphthylamine is preferable.

  The present invention also provides a color composition for a color filter comprising a red pigment, the pigment dispersant of the present invention, a resin dispersant, and a resin varnish. The red pigment is C.I. I. Pigment Red 254; and the resin dispersant is preferably a cationic resin dispersant.

  Further, the present invention is a method for producing a color filter comprising a step of forming a colored pixel on a color filter substrate, wherein the colored pixel is formed using the colored composition for a color filter of the present invention. A color filter manufacturing method, a color filter manufactured by the method, an image display device including the color filter, and an image display device including the image display device Provide information transmission equipment.

  According to the present invention as described above, by using a specific pigment dispersant as a pigment dispersant for a color filter red color forming composition, a color filter coloring composition can be stably produced, and foreign matter In addition, when used as a coloring composition for color filters, it has excellent spectral curve characteristics, is clear and crisp, has high transparency, and is light and heat resistant. A color filter having pixels excellent in various fastnesses such as solvent resistance, chemical resistance and water resistance can be obtained.

Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention. The pigment dispersant of the present invention comprises the component (a) alone or the component (a) and the component (b).
The component (a) is a pigment complex of a diketopyrrolopyrrole pigment having a sulfone group and a diketopyrrolopyrrole pigment not having a sulfone group, and the component per diketopyrrolopyrrole pigment molecule in the complex It is a pigment composite in which the number of sulfone groups is 0.05 to 0.5.

  One example of the method for preparing the component (a) is a diketopyrrolopyrrole pigment having no sulfone group represented by the following general formula (V), such as C.I. I. When the Pigment Red 254 is sulfonated with a sulfonating agent such as fuming sulfuric acid, the sulfonation conditions are adjusted so that the number of sulfone groups introduced into the diketopyrrolopyrrole pigment is within the above range.

（但し、式中のＲ₁およびＲ₂は、互いに独立して、水素原子、ハロゲン原子、シアノ基、アルキル基またはフェニル基である。）

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group or a phenyl group.)

  When the number of sulfonate groups per molecule of the sulfonated product is more than 0.5, the disulfonate that is not sulfonated so that the average number of sulfonate groups is in the range of 0.05 to 0.5. Ketopyrrolopyrrole pigment is mixed with the sulfonated product, the mixture is dissolved in concentrated sulfuric acid, the solution is poured into ice water, the complex is precipitated, washed with water and dried to obtain the desired pigment dispersion. An agent can be obtained.

  A complex in which the number of sulfone groups is adjusted to 0.05 to 0.5 significantly decreases the affinity and solubility in water and solvent, and exhibits a substantially insoluble or hardly soluble pigment-like behavior. This is because non-sulfonated diketopyrrolopyrrole pigment molecules added to the sulfonated diketopyrrolopyrrole pigment molecules stack (eutectic or mixed) with the sulfonated diketopyrrolopyrrole molecules, and the sulfonated diketo. It is considered that the affinity and solubility of pyrrolopyrrole molecules in water are reduced.

  The sulfone group of the diketopyrrolopyrrole pigment complex may be free or a salt with a base. Examples of the metal forming the salt include alkali metals such as Li, Na, and K, and polyvalent metals such as Ca, Ba, Al, Mn, Sr, Mg, and Ni. Examples of the amine that forms an amine salt or an ammonium salt include (mono, di, or tri) alkylamines, substituted or unsubstituted alkylenediamines, alkanolamines, alkylammonium chloride, and ammonia.

The component (b) is a dye other than the component (a) having a sulfone group, a metal salt thereof, an ammonium salt thereof or an amine salt group, and any of such conventionally known dyes can be used. The component (b) is a compound represented by the above general formula (I), general formula (II), general formula (III) or general formula (IV), a metal salt thereof, an ammonium salt and / or an amine salt. It is preferable.
The compound represented by the general formula (I) may have 1 mol of 1-aminoanthraquinone which may have a substituent and aniline which may have a substituent or a substituent. Either 1 mol of phenol or 1-aminoanthraquinone optionally having substituent (s) and 1 mol of cyanuric chloride in an inert solvent such as o-dichlorobenzene, 2 to 6 at 130 ° C to 170 ° C. It can be obtained by reacting for 1 hour and further reacting 1 mol of an aliphatic amine or aromatic amine having one sulfone group at 150 ° C. to 170 ° C. for 3 to 4 hours.

  Examples of the aliphatic amine or aromatic amine having one sulfone group used for the production of the compound of the general formula (I) include taurine, N-methyltaurine, o-aminobenzenesulfonic acid, m-aminobenzene. Sulfonic acid, sulfanilic acid, 4-chloroaniline-3-sulfonic acid, 2-nitroaniline-4-sulfonic acid, 2-aminophenol-4-sulfonic acid, o-anisidine-5-sulfonic acid, p-anisidine-5 -Sulfonic acid, o-toluidine-4-sulfonic acid, m-toluidine-4-sulfonic acid, p-toluidine-2-sulfonic acid, 2-chloro-p-toluidine-3-sulfonic acid, 3-amino-6- Chloro-4-sulfobenzoic acid, 1-amino-8-naphthalenesulfonic acid, 2-amino-1-naphthalenesulfonic acid, 5-amino-1 Naphthalenesulfonic acid, 6-amino-1-naphthalenesulfonic acid and 5-amino-3-naphthalenesulfonic acid.

  Moreover, the compound represented by the said general formula (II) is 1-aminoanthraquinone which may have a substituent, and 1 mol of cyanuric chloride in inert solvents, such as o-dichlorobenzene. The reaction is carried out at 130 ° C. to 170 ° C. for 2 to 6 hours, 1 mol of an aromatic amine having no sulfone group is added, and the reaction is carried out at 150 ° C. to 170 ° C. for 3 to 4 hours. It can be obtained by sulfonation with a sulfonating agent.

  Examples of the aromatic amine used for the production of the compound of the general formula (II) include aniline, N-methylaniline, toluidine (o-, m- or p-), anisidine (o-, m- or p). -), Chloroaniline (o-, m- or p-), diphenylamine, 1-naphthylamine, 2-naphthylamine and the like.

  The compound represented by the general formula (III) is a quinophthalone compound that can be easily synthesized from phthalic anhydride which may have a substituent and quinaldine which may have a substituent. It can be obtained by sulfonation with an agent.

R _{1 in} the general formula (III) is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted phthalimide group, and R ₂ is a hydrogen atom or a hydroxyl group. R ₃ represents a halogen atom, m represents an integer of 0 to 4, n represents the average number of sulfone groups introduced into the compound, and is a number of 0.5 to 4. The alkyl group is a linear or branched alkyl group having about 1 to 8 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. An aryl group represents an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, an anthranyl group, or a phenanthryl group, which may be unsubstituted or substituted. Examples of the substituent include, but are not limited to, a halogen atom, a hydroxyl group, and an alkyl group.

  The compound represented by the general formula (IV) may have an acid chloride of 3-hydroxy-2-naphthoic acid which may have a substituent, and may have a substituent at the 2,5-position. 1,4-phenylenediamine or benzidine which may have a substituent at the 3,3′-position is reacted at 130 to 135 ° C. in an inert solvent such as nitrobenzene, and then has a substituent. It can be obtained by diazotizing and coupling the aminobenzene sulfonic acid which may be further substituted and the aniline which may have a substituent, by a conventional method.

  Moreover, as a metal which forms a metal salt with the compound shown by the said general formula (I)-general formula (IV), for example, alkali metals, such as Li, Na, and K, Ca, Ba, Al, Mn, Sr, Multivalent metals such as Mg and Ni are listed. Examples of amines that form amine salts with the compounds represented by formulas (I) to (IV) include (mono, di, or tri) alkylamines, substituted or unsubstituted alkylenediamines, and alkanols. Examples include amines and alkyl ammonium chlorides.

  The component (a) can be used alone as a pigment dispersant, and the component (a) is a compound represented by one of the general formulas (I) to (IV) ((b) Component). When the component (a) and the component (b) are used in combination, the mass ratio of the component (a) to the component (b) is (a) component: (b) component = 10: 90 to 90:10. Yes, preferably 40:60 to 60:40. When the amount of component (a) used is outside the above range, the viscosity of the dispersion is insufficiently lowered, and the temporal stability of the dispersion is lowered.

  The coloring composition for a color filter of the present invention comprises a pigment, the above-described pigment dispersant, a resin dispersant (a pigment dispersant for dispersing a pigment made of a polymer compound), and a resin varnish. Examples of the pigment used in the present invention include a diketopyrrolopyrrole pigment as a red pigment. Such red pigments include C.I. I. Pigment red 254 and the like. At that time, as color correction, a yellow pigment may be blended and dispersed together. As such a yellow pigment, an isoindoline pigment (CI Pigment Yellow 139) or the like can be used. Although the usage-amount of the said red pigment is not specifically limited, Usually, it is used in the ratio of 5-500 mass parts with respect to 100 mass parts of resin binders of the below-mentioned resin varnish.

  The blending ratio of the pigment dispersant to the pigment is preferably 0.05 to 40 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the pigment. When the blending ratio of the pigment dispersant is too small, it is difficult to sufficiently obtain the effect of the target pigment dispersant. In addition, if the blending ratio of the pigment dispersant is too large, the effect of using only a large amount cannot be obtained, and conversely, the resulting physical properties of the color filter coloring composition are lowered, and further the pigment dispersant itself. The hue of the pigment to be dispersed greatly changes depending on the color of the.

  As the resin dispersant used in the present invention, a known dispersant can be used, and a cationic resin dispersant is particularly preferable. Examples of the cationic resin dispersant include trade names of BYK (Big) Chemie (Germany): DISPER BYK-160, 161, 162, 163, 164, 166, 171, 182, and the like. 184, 2000, 2001, 2070, 2150; trade names of EFKA (Netherlands): EFKA-44, 46, 47, 48, 4010, 4050, 4055, 4020, 4015 4060, 4300, 4330, 4400, 4406, 4510, 4800; trade names of Avecia (UK): SOLSPERS-24000, 32550, NBZ-4204 / 10; products of Kawaken Fine Chemicals, Inc. Name: Hinoact T-6000, 7000, 8000; Ajinomoto Co. product names: Ajisper PB-821, 822, 8 3; Kyoeisha Chemical Co., Ltd. under the trade name: Flowlen DOPA-17HF, same 15BHF, the same 33, such as the 44, and the like.

  The addition amount of the resin dispersant used in the present invention is not particularly limited, but is preferably 2 to 100 parts by mass, more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the pigment. When the addition amount of the resin dispersant is less than 2 parts by mass, good pigment dispersion stability cannot be obtained, and when it is more than 100 parts by mass, the developability of the film formed from the color composition for color filter obtained is poor. There is a case.

  As the resin varnish used as a dispersion medium for dispersing the pigment in the present invention, any known resin varnish conventionally used in coloring compositions for color filters can be used and is not particularly limited. In addition, an appropriate solvent or aqueous medium is used as the dispersion medium in the resin varnish. In addition, conventionally known additives such as a dispersion aid, a smoothing agent, and an adhesive agent are appropriately added and used as necessary.

  As the resin varnish, a photosensitive resin varnish and a non-photosensitive resin varnish are used. Examples of the photosensitive resin varnish include photosensitive resin varnishes used for ultraviolet curable inks and electron beam curable inks. Non-photosensitive resin varnishes include, for example, letterpress ink, planographic ink, intaglio gravure ink, and the like. For resin varnishes used for printing inks such as stencil screen ink, resin varnishes used for inkjet printing, resin varnishes used for electrodeposition coating, resin varnishes used for developers of electronic printing and electrostatic printing, thermal transfer films or ribbons Examples of the resin varnish to be used.

  Specific examples of the photosensitive resin varnish include, for example, a photosensitive cyclized rubber resin, a photosensitive phenol resin, a photosensitive polyacrylate resin, a photosensitive polyamide resin, and a photosensitive polyimide resin. Monomers are added as reactive diluents to varnishes such as unsaturated polyester resins, polyester acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, polyol acrylate resins. Varnish. As a suitable resin among the photosensitive resin varnish, an alkali-developable acrylate resin having a free carboxylic acid group in the molecule is desirable.

  Specific examples of the non-photosensitive resin varnish include, for example, a cellulose acetate resin, a nitrocellulose resin, a styrene (co) polymer, a polyvinyl butyral resin, an aminoalkyd resin, a polyester resin, and an amino resin modified polyester. Water-soluble resin, polyurethane resin, acrylic polyol urethane resin, soluble polyamide resin, soluble polyimide resin, soluble polyamideimide resin, soluble polyesterimide resin, hydroxyethyl cellulose, styrene-maleic acid ester copolymer Examples thereof include salts, water-soluble salts of (meth) acrylic acid ester-based (co) polymers, water-soluble aminopolyester resins, and water-soluble polyamide-based resins, and these are used alone or in combination of two or more.

Although the manufacturing method in particular of the coloring composition comprised from said each component of this invention is not restrict | limited, For example, the following method etc. are mentioned.
(A) After dissolving the pigment and the pigment dispersant in sulfuric acid or the like, the mixture is poured into water, both are made into a solid solution, added to the resin varnish together with the cationic resin dispersant, and kneaded.
(B) A cationic resin obtained by uniformly suspending a pigment in water or an organic solvent, adding a solution containing a pigment dispersant to the suspension, and depositing the pigment dispersant on the surface of the pigment particles. Add to resin varnish with dispersant and knead.
(C) A pigment, a pigment dispersant, and a cationic resin dispersant are finely dispersed with a wet medium disperser such as an attritor or a ball mill, and added to the resin varnish and kneaded.
(D) A pigment, a pigment dispersant, and a cationic resin dispersant are added to the resin varnish at the time of premixing, and are dispersed by a wet medium disperser.

  When a photosensitive resin varnish is used as the resin varnish when producing a color filter using the colored composition of the present invention, a conventionally known photopolymerization initiator such as benzoin ethyl ether or benzophenone is used in the composition. In addition, a photosensitive coloring composition is prepared and used by kneading by a conventionally known method. Moreover, it can replace with said photoinitiator and can also use it as a thermopolymerizable coloring composition using a thermal polymerization initiator.

  When forming a pixel of a color filter on a substrate using the above photosensitive coloring composition, the photosensitive coloring composition is formed on a transparent substrate, for example, a spin coater, a low-speed rotation coater, a roll coater or a knife coater. The entire surface is coated by using a suitable method among various printing methods, or a partial printing slightly larger than the pixel is performed, and after pre-drying, the photomask is adhered to the coating or printing surface of the transparent substrate. Then, exposure is performed using an ultra-high pressure mercury lamp, and the pixels are printed. Next, development and washing are performed, and post-baking is performed as necessary to form pixels. These pixel forming methods are known per se, and the pixel forming method of the color filter is not particularly limited in the present invention.

  When forming a pixel of a color filter using the colored composition of the present invention (non-photosensitive colored composition) using a non-photosensitive resin varnish, the non-photosensitive colored composition is formed on a transparent substrate, for example, A method for forming a pixel directly on a substrate by printing by a suitable method among the above-mentioned various printing methods as a printing ink for a color filter, and applying to a substrate by an electrodeposition coating method as an aqueous electrodeposition coating composition A method for forming pixels, a method for forming pixels on a substrate by printing by inkjet printing as inkjet ink, an electronic printing method or an electrostatic printing method, or transfer by one of the above methods For example, a method may be used in which a pixel is once formed by applying to a conductive substrate and then transferred to a color filter substrate. Then, according to a conventional method, baking is performed as necessary, polishing for smoothing the surface, or top coating for protecting the surface is performed. Further, a black matrix is formed according to a conventional method. In this way, a color filter having RGB pixels can be obtained. The manufacturing methods of these color filters are known per se, and the manufacturing method of the color filters is not particularly limited in the present invention.

  Next, the present invention will be described more specifically with reference to synthesis examples, examples and comparative examples. In the text, “part” or “%” is based on mass.

[Synthesis Example A1]
30 parts of diketopyrrolopyrrole pigment (CI Pigment Red 254) are added to 300 parts of 20% fuming sulfuric acid, and then reacted at 60 to 65 ° C. for 6 hours. After cooling, the reaction mixture was precipitated in 3,000 parts of ice water, filtered and washed with water to obtain 110 parts of water paste (pure 28 parts). This water paste was dried, and 28 parts of diketopyrrolopyrrole (pigment dispersant A1) having an average of 0.8 sulfone groups introduced per molecule was obtained from the result of elemental analysis of sulfur.

  Also 5 parts of pigment dispersant A1 and 5 parts of C.I. I. Pigment Red 254 is added to 100 parts of 95% concentrated sulfuric acid and stirred at room temperature for 1 hour. After cooling, the resulting concentrated sulfuric acid solution was poured into 1,000 parts of ice water to precipitate a composite, filtered and washed with water to obtain 39 parts of a water paste (pure 10 parts). This water paste was dried, and 10 parts of diketopyrrolopyrrole (pigment dispersant A2) having an average of 0.4 sulfone groups introduced per molecule was obtained from the result of elemental analysis of sulfur.

[Synthesis Example A2]
3.75 parts of Pigment Dispersant A1 of Synthesis Example A1 and 6.25 parts of C.I. I. Pigment Red 254 is added to 100 parts of 95% concentrated sulfuric acid and stirred at room temperature for 1 hour. After cooling, the resulting concentrated sulfuric acid solution was poured into 1,000 parts of ice water to precipitate a composite, filtered and washed with water to obtain 39 parts of a water paste (pure 10 parts). This water paste was dried, and 10 parts of diketopyrrolopyrrole (pigment dispersant A3) having an average of 0.3 sulfone groups introduced per molecule was obtained from the result of elemental analysis of sulfur.

[Synthesis Example A3]
2.5 parts of Pigment Dispersant A1 of Synthesis Example A1 and 7.5 parts of C.I. I. Pigment Red 254 and 10 parts of diketopyrrolopyrrole in which an average of 0.2 sulfone groups are introduced per molecule from the result of elemental analysis of sulfur in the same manner as in Synthesis Example A2 (pigment dispersant A4) Got.

[Synthesis Example A4]
30 parts of diketopyrrolopyrrole pigment (CI Pigment Red 254) are added to 300 parts of 20% fuming sulfuric acid, and then reacted at 45-50 ° C. for 6 hours. After cooling, the reaction mixture was precipitated in 3,000 parts of ice water, filtered and washed with water to obtain 110 parts of water paste (pure 28 parts). This water paste was dried, and 28 parts of diketopyrrolopyrrole (pigment dispersant A5) having an average of 0.4 sulfone groups introduced per molecule was obtained from the result of elemental analysis of sulfur.

[Example A1]
50 parts of acrylic resin varnish (methacrylic acid / butyl acrylate / styrene / hydroxyethyl acrylate copolymerized at a molar ratio of 25/50/15/10, molecular weight 12,000, solid content 30%) I. 20 parts of Pigment Red 254, 4 parts of isoindoline yellow pigment (CI Pigment Yellow 139), 1 part of Pigment Dispersant A2 obtained in Synthesis Example A1, Cationic Resin Dispersant (Disper BYK-2000) 4 20 parts of a solvent and a solvent (propylene glycol monomethyl ether acetate) (hereinafter abbreviated as PGMAc) were blended and dispersed by a horizontal bead mill after premixing to obtain a red colored composition.

[Examples A2 to A4]
Instead of pigment dispersant A2 of Example A1, pigment dispersants A3 to A5 obtained in Synthesis Examples A2 to A4 were used, respectively, and other procedures were performed in the same manner as Example A1 to obtain a red colored composition.
[Comparative Example A1]
Instead of the pigment dispersant A2 of Example A1, the pigment dispersant A1 obtained in Synthesis Example A1 was used to obtain a red colored composition in the same manner as in Example A1.

The fluidity of the coloring compositions of the above Examples A1 to A4, the gloss of the color development surface, and the presence or absence of foreign matter generation were compared with the case of Comparative Example A1. The fluidity and color gloss of each colored composition were measured according to the following method, and the presence or absence of foreign matter was observed by the following method. The observation results of these measurements before and after storage of the colored compositions of Examples A1 to A4 at room temperature for 1 month were compared with those of Comparative Example A1.
Flowability: Using an E-type viscometer, each colored composition was measured under conditions of room temperature (25 ° C.) and a rotor rotation speed of 6 rpm.

Gloss: Using a bar coater (winding thickness: 0.45 mm), each colored composition was separately developed on a polypropylene film, and the gloss of the developed surface was compared visually and with a gloss meter. In addition, the thing with high gloss was evaluated as favorable, and the comparison result was displayed with the following evaluation index.
○: Good Δ: Slightly good ×: Observation of defective foreign matter: Each colored composition was applied to a glass substrate with a spinner, dried at 90 ° C. for 2 minutes, and formed into a film. The presence or absence was observed, and the observation results were displayed with the following evaluation indices.
○: No foreign matter Δ: Slightly foreign matter ×: Very foreign matter The results of the above measurement and evaluation are shown in Table A1.

  As is apparent from Table A1, the colored compositions of Examples A1 to A4 using pigment dispersants A2 to A5 are more viscous after storage than the compositions of Comparative Example A1 using pigment dispersant A1. (After 1 month) was low, the gloss was good, no foreign matter was generated before and after storage, and the composition had excellent properties as a colored composition.

[Reference Example A1]
50 parts of the same kind of acrylic resin varnish used in Example A1, 17 parts of odor chlorinated phthalocyanine green (CI Pigment Green 36), 13 parts of quinophthalone yellow pigment (CI Pigment Yellow 138), pigment As a dispersant, 2 parts of monosulfonated quinophthalone yellow, 4 parts of cationic resin dispersant (Disper BYK-2000) and 20 parts of PGMAc were blended, and after premixing, dispersed with a horizontal bead mill to obtain a green colored composition.

[Reference Example A2]
50 parts of the same kind of acrylic resin varnish used in Example A1, 16 parts of ε-type copper phthalocyanine blue (CI Pigment Blue 15: 6), 4 parts of dioxazine violet (CI Pigment Violet 23) , 2 parts of monosulfonated phthalocyanine blue, 1 part of monosulfonated indantron, 4 parts of cationic resin dispersant (Disper BYK-2000) and 20 parts of PGMAc as pigment dispersant, premixed and dispersed with horizontal bead mill A blue colored composition was obtained.

[Example A5]
In order to produce RGB color filters, colored compositions of R, G, and B were obtained according to the formulation of Table A2 below.

The glass substrate treated with the silane coupling agent was set on a spin coater, and the colored composition of R in Table A2 was first spin-coated at 300 rpm for 5 seconds and then at 1200 rpm for 5 seconds. Subsequently, prebaking was performed at 80 ° C. for 10 minutes, a photomask having a mosaic pixel pattern was brought into close contact with the prebaked film, and exposure was performed with an ultrahigh pressure mercury lamp at a light amount of 100 mJ / cm ² . Next, development and washing were performed with a dedicated developer and a dedicated rinse to form red mosaic pixels on the glass substrate. Subsequently, a green mosaic pixel and a blue mosaic pixel are formed by applying and baking according to the above method using the colored compositions of G and B in Table A2 to obtain a color filter having RGB pixels. It was. The resulting color filter has excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance of each pixel, and excellent properties as a color filter for liquid crystal color displays with excellent light transmission showed that.

[Synthesis Example B1]
To 1,000 parts of nitrobenzene, 72 parts of 1-aminoanthraquinone and 30 parts of cyanuric chloride are added and stirred at 170 ° C. for 5 hours. After cooling, 41 parts taurine and 23 parts potassium carbonate are added and stirred at 180 ° C. for 8 hours. After cooling, the precipitate was filtered, washed with alcohol, then peptized into water and made acidic with hydrochloric acid. The precipitate was collected by filtration, washed with water and dried to obtain 94 parts of the following compound B1.

[Synthesis Example B2]
To 1,000 parts of nitrobenzene, 72 parts of 1-aminoanthraquinone and 30 parts of cyanuric chloride are added and stirred at 170 ° C. for 5 hours. After cooling, 56 parts sulfanilic acid and 23 parts potassium carbonate are added and stirred at 180 ° C. for 12 hours. After cooling, it was filtered, washed with alcohol, then peptized into water to make it acidic with hydrochloric acid, washed with water and dried to obtain 101 parts of the following compound B2.

[Synthesis Example B3]
73 parts of 1-aminoanthraquinone and 30 parts of cyanuric chloride are added to 1,100 parts of o-dichlorobenzene and stirred at 170 ° C. for 5 hours. After cooling, 35 parts of o-toluidine is added and stirred at 180 ° C. for 5 hours. After cooling, it was filtered, washed with alcohol, then washed with water and dried to obtain 94 parts of 2,4-bis (1-anthraquinonylamino) -6-tolylamino-1,3,5-triazine. Next, 94 parts of this compound is added to 800 parts of 5% fuming sulfuric acid at 10 ° C. or lower, and then reacted at 30 ° C. for 5 hours. After cooling, the reaction mixture was precipitated in 2,500 parts of ice water, filtered and washed with water. From the result of elemental analysis of sulfur, an average of 0.9 sulfone groups per molecule was introduced. 102 parts were obtained.

[Example B1]
Diketopyrrolopyrrole in 50 parts of acrylic resin varnish (copolymerized methacrylic acid / butyl acrylate / styrene / hydroxyethyl acrylate in a molar ratio of 25/50/15/10, molecular weight 12,000, solid content 30%) 20 parts of pigment (CI Pigment Red 254), 4 parts of isoindoline yellow pigment (CI Pigment Yellow 139), 1 part of Compound B1 obtained in Synthesis Example B1, obtained in Synthesis Example A4 One part of the pigment dispersant A5, 4 parts of a cationic resin dispersant (Disper BYK-2000) and 20 parts of PGMAc were blended, and after premixing, the mixture was dispersed with a horizontal bead mill to obtain a red colored composition.

[Example B2]
A red colored composition was obtained in the same manner as in Example B1, except that Compound B2 of Synthesis Example B2 was used instead of Compound B1.

[Example B3]
A red colored composition was obtained in the same manner as in Example B1, except that Compound B3 of Synthesis Example B3 was used instead of Compound B1.

[Comparative Example B1]
A red colored composition was obtained in the same manner as in Example B1, except that only the compound B1 was used without using the pigment dispersant A5.

[Comparative Example B2]
A red colored composition was obtained in the same manner as in Example B1 except that only the compound B2 was used without using the pigment dispersant A5.

[Comparative Example B3]
A red colored composition was obtained in the same manner as in Example B1 except that only the compound B3 was used without using the pigment dispersant A5.

  The fluidity and color gloss of the colored compositions of Examples B1 to B3 described above were compared with those of Comparative Examples B1 to B3. The fluidity of each colored composition and the gloss (after one month storage) of the color development surface were measured according to the same method as described above, and the relative evaluation was performed in the same manner as in Comparative Examples B1 to B3. The above measurement and evaluation results are shown in Table B1.

  As is apparent from Table B1, the colored compositions of Examples B1 to B3 using the compounds B1 to B3 and the pigment dispersant A5 in combination with the compositions of Comparative Examples B1 to B3 using the compounds B1 to B3 alone. In comparison, the viscosity before storage and after storage (after one month) was low, the gloss was good, and the coloring composition had excellent properties.

[Example B4]
In order to produce a color filter having each pixel of RGB, colored compositions of R, G and B were obtained according to the formulation of Table B2 below.

  Thereafter, a color filter having RGB pixels was obtained in the same manner as in Example A5. The obtained color filter had excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent light transmission, and showed excellent properties as a color filter for liquid crystal color display. .

[Synthesis Example C1]
50 parts of tetrachloroquinophthalone are added to 250 parts of 20% fuming sulfuric acid and then reacted at 80 ° C. for 6 hours. After cooling, the reaction mixture was precipitated in 2,000 parts of ice water, filtered and washed with water to obtain 280 parts (pure 55 parts) of an aqueous paste of the following compound C1. This water paste was dried, and 55 parts of Compound C1 into which an average of 1.3 sulfone groups were introduced per molecule were obtained from the results of elemental analysis of sulfur.

[Synthesis Example C2]
240 parts of water was added to 90 parts (pure amount 18 parts) of the compound C1 paste of Synthesis Example C1, and the mixture was stirred at 25 ° C. for 1 hour. To this, 7 parts of tetrabutylammonium chloride was added and stirred for 1 hour. The precipitate was filtered, washed with water and dried to obtain 17 parts of the following compound C2.

[Synthesis Example C3]
Instead of 50 parts of tetrachloroquinophthalone, C.I. I. Except for using 50 parts of Pigment Yellow 138, the same operation as in Synthesis Example C1 was performed, and an average of 0.9 sulfone groups per molecule was introduced from the result of elemental analysis of sulfur. Got a part.

[Synthesis Example C4]
The same operation as in Synthesis Example C2 was carried out except that 90 parts of the water paste of Compound C3 of Synthesis Example C3 was used instead of 90 parts of the water paste of Compound C1 of Synthesis Example C1, and 18 parts of the following Compound C4 was obtained. .

[Example C1]
Diketopyrrolopyrrole in 50 parts of acrylic resin varnish (copolymerized methacrylic acid / butyl acrylate / styrene / hydroxyethyl acrylate in a molar ratio of 25/50/15/10, molecular weight 12,000, solid content 30%) 20 parts of pigment (CI Pigment Red 254), 4 parts of isoindoline yellow pigment (CI Pigment Yellow 139), 1 part of Compound C1 obtained in Synthesis Example C1, obtained in Synthesis Example A4 One part of pigment dispersant A5, 4 parts of cationic resin dispersant (Ajisper PB-821) and 20 parts of PGMAc were blended, and after premixing, the mixture was dispersed by a horizontal bead mill to obtain a red colored composition.

[Example C2]
A red colored composition was obtained in the same manner as in Example C1, except that Compound C2 of Synthesis Example C2 was used instead of Compound C1.

[Example C3]
A red colored composition was obtained in the same manner as in Example C1, except that Compound C3 of Synthesis Example C3 was used instead of Compound C1.

[Example C4]
A red colored composition was obtained in the same manner as in Example C1, except that Compound C4 of Synthesis Example C4 was used instead of Compound C1.

[Comparative Example C1]
A red colored composition was obtained in the same manner as in Example C1, except that the pigment dispersant A5 was not used and only the compound C1 was used.

[Comparative Example C2]
A red colored composition was obtained in the same manner as in Example C1, except that the pigment dispersant A5 was not used and only the compound C2 was used.

[Comparative Example C3]
A red colored composition was obtained in the same manner as in Example C1 except that only the compound C3 was used without using the pigment dispersant A5.

[Comparative Example C4]
A red colored composition was obtained in the same manner as in Example C1 except that only the compound C4 was used without using the pigment dispersant A5.

  The fluidity of the coloring compositions of Examples C1 to C4 and the gloss of the color development surface were compared with those of Comparative Examples C1 to C4. The fluidity of each coloring composition and the gloss of the color-extended surface (after storage for 1 month) were measured according to the same method as described above, and the relative evaluation was performed with Comparative Examples C1 to C4. The above measurement and evaluation results are shown in Table C1.

  As is clear from Table C1, the colored compositions of Examples C1 to C4 using the compounds C1 to C4 and the pigment dispersant A5 in combination with the compositions of Comparative Examples C1 to C4 using the compounds C1 to C4 alone. In comparison, the viscosity before storage and after storage (after one month) was low, the gloss was good, and the coloring composition had excellent properties.

[Example C5]
In order to produce a color filter having RGB pixels, colored compositions of R, G, and B were obtained according to the formulation of Table C2 below.

  Thereafter, a color filter having RGB pixels was obtained in the same manner as in Example A5. The obtained color filter had excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent light transmission, and showed excellent properties as a color filter for liquid crystal color display. .

[Synthesis Example D1]
According to a conventional method, 60 parts of 3-hydroxy-2-naphthoic acid was acidified with 40 parts of thionyl chloride in 400 parts of nitrobenzene, and 25 parts of 2,5-dichloro-1,4-phenylenediamine was added to add 130 to 135. Heat at 5 ° C. for 5 hours. After cooling, 200 parts of methanol was added, and the purified precipitate was filtered, washed with methanol and then with water, and dried to obtain 60 parts of a reaction product. To 10 parts of this, 100 parts of methanol, 3 parts of sodium hydroxide, and 11 parts of sodium acetate trihydrate are added to prepare a submerged solution. 3.5 parts of p-aminobenzenesulfonic acid is diazotized by a conventional method and coupled to the above-described submerged solution. After 1 hour, 4.3 parts of 2-chloro-5-trifluoromethylaniline is diazotized by a conventional method. From the result of elemental analysis of sulfur, 11 parts of the following compound D1 in which an average of one sulfone group was introduced per molecule were obtained.

[Synthesis Example D2]
From the result of elemental analysis of sulfur in the same manner as in Synthesis Example D1, except that 35 parts of 3,3′-dichlorobenzidine is used instead of 25 parts of 2,5-dichloro-1,4-phenylenediamine in Synthesis Example D1. 11 parts of the following compound D2 into which an average of one sulfone group was introduced per molecule were obtained.

[Example D1]
Diketopyrrolopyrrole in 50 parts of acrylic resin varnish (copolymerized methacrylic acid / butyl acrylate / styrene / hydroxyethyl acrylate in a molar ratio of 25/50/15/10, molecular weight 12,000, solid content 30%) 20 parts of pigment (CI Pigment Red 254), 4 parts of isoindoline yellow pigment (CI Pigment Yellow 139), 1 part of Compound D1 obtained in Synthesis Example D1, obtained in Synthesis Example A4 One part of pigment dispersant A5, 4 parts of cationic resin dispersant (Solsperse-24000) and 20 parts of PGMAc were blended, and after premixing, the mixture was dispersed by a horizontal bead mill to obtain a red colored composition.

[Example D2]
A red colored composition was obtained in the same manner as in Example D1, except that Compound D2 of Synthesis Example D2 was used instead of Compound D1.

[Comparative Example D1]
A red colored composition was obtained in the same manner as in Example D1, except that only the compound D1 was used without using the pigment dispersant A5.

[Comparative Example D2]
A red colored composition was obtained in the same manner as in Example D1, except that the pigment dispersant A5 was not used and only the compound D2 was used.

  The fluidity of the coloring compositions of the above Examples D1 to D2 and the gloss of the color development surface were compared with those of Comparative Examples D1 to D2. The fluidity of each coloring composition and the gloss of the color-extended surface (after storage for 1 month) were measured according to the same method as described above, and the relative evaluation was performed as in the comparative example. The above measurement and evaluation results are shown in Table D1.

  As is clear from Table D1, the coloring compositions of Examples D1 to D2 using the compounds D1 to D2 and the pigment dispersant A5 in combination with the compositions of Comparative Examples D1 to D2 using the compounds D1 and 2 alone. In comparison, the viscosity before storage and after storage (after one month) was low, the gloss was good, and the coloring composition had excellent properties.

[Example D3]
In order to produce a color filter having RGB pixels, colored compositions of R, G, and D were obtained according to the formulation of Table D2 below.

  Thereafter, a color filter having RGB pixels was obtained in the same manner as in Example A5. The obtained color filter had excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent light transmission, and showed excellent properties as a color filter for liquid crystal color display. .

  According to the present invention, due to the synergistic effect of using a specific pigment dispersant as a pigment dispersant for the color pixel forming color composition of the color filter, the aggregation of pigment particles more specifically than when each is used alone. Can be prevented. Therefore, the colored composition can also be stably produced, and the occurrence of foreign matters can be prevented. Also, when used as a colored composition, the colored composition has excellent spectral curve characteristics and has a clear and brilliant color tone. A color filter having a pixel with excellent transparency and high fastness such as light resistance, heat resistance, solvent resistance, chemical resistance and water resistance can be obtained.

Claims (14)

The pigment dispersant characterized by including the following (a) component alone or the following (a) component and the following (b) component.
Component (a): a pigment complex of a diketopyrrolopyrrole pigment having a sulfone group and a diketopyrrolopyrrole pigment having no sulfone group, the sulfone per molecule of the diketopyrrolopyrrole pigment in the complex A pigment composite having 0.05 to 0.5 groups.
Component (b): a dye other than the component (a) having a sulfone group, a metal salt thereof, an ammonium salt thereof or an amine salt thereof. The component (b) is a compound represented by the following general formula (I), general formula (II), general formula (III) or general formula (IV), a metal salt, an ammonium salt and / or an amine salt thereof. The pigment dispersant according to claim 1.

(In the formula, X ₁ is a hydrogen atom, a halogen atom, an alkyl group or an acylamino group; Y ₁ is an anthraquinonylamino group, a phenylamino group, a naphthylamino group or a phenoxy group, and these groups are The substituent may contain a halogen atom, an alkyl group or an acylamino group, R ₁ is a hydrogen atom, an alkyl group or a phenyl group, R ₂ is an alkylene group, a phenylene group or a naphthylene group, (It may contain a substituent.)

(However, X ₁ in the formula is a hydrogen atom, a halogen atom or an alkyl group, R ₁ is a hydrogen atom, an alkyl group or a phenyl group, R ₂ is a phenyl group or a naphthyl group, and these are substituted. And k is the average number of sulfone groups in the compound and is a number from 0.5 to 2.)

(In the formula, R ₁ is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an unsubstituted or substituted aryl group, an unsubstituted or substituted phthalimide group, and R ₂ is a hydrogen atom or a hydroxyl group; R ₃ is a halogen atom, m represents an integer of 0 to 4, n is the average number of sulfone groups introduced into the compound, and is a number of 0.5 to 4.)

The pigment dispersant according to claim 1, wherein the diketopyrrolopyrrole pigment having no sulfone group is represented by the following general formula (V).

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group or a phenyl group.)   The pigment dispersant according to claim 1, wherein the sulfone group of the diketopyrrolopyrrole pigment having a sulfone group is at least one selected from a free sulfone group, a metal salt of the sulfone group, an amine salt, and an ammonium salt. R _{2 in the} general formula (I) is taurine, N-methyltaurine, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, sulfanilic acid, 4-chloroaniline-3-sulfonic acid, 2-nitroaniline-4 -Sulfonic acid, 2-aminophenol-4-sulfonic acid, o-anisidine-5-sulfonic acid, p-anisidine-5-sulfonic acid, o-toluidine-4-sulfonic acid, m-toluidine-4-sulfonic acid, p-toluidine-2-sulfonic acid, 2-chloro-p-toluidine-3-sulfonic acid, 3-amino-6-chloro-4-sulfobenzoic acid, 1-amino-8-naphthalenesulfonic acid, 2-amino- 1-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, 6-amino-1-naphthalenesulfonic acid and 5-amino-3-naphthalene Pigment dispersing agent according to claim 2 from the amine selected from sulfonic acid, a group obtained by removing an amino group. R _{2 in the} general formula (II) is aniline, N-methylaniline, toluidine (o-, m- or p-), anisidine (o-, m- or p-), chloroaniline (o-, m- or The pigment dispersant according to claim 2, which is a group obtained by removing an amino group from an amine selected from p-), diphenylamine, 1-naphthylamine and 2-naphthylamine.   The pigment dispersant according to claim 1, wherein a mass ratio of the component (a) to the component (b) is a: b = 10: 90 to 90:10.   A coloring composition for a color filter, comprising a red pigment, the pigment dispersant according to claim 1, a resin dispersant, and a resin varnish.   The red pigment is C.I. I. The coloring composition for a color filter according to claim 8, which is CI Pigment Red 254.   The colored composition for a color filter according to claim 8, wherein the resin dispersant is a cationic resin dispersant.   A color filter manufacturing method comprising a step of forming a colored pixel on a substrate for a color filter, wherein the colored pixel is formed using the colored composition for a color filter according to claim 8. Manufacturing method.   A color filter manufactured by the method according to claim 11.   An image display device comprising the color filter according to claim 12.   An information transmission device comprising the image display device according to claim 13.